Initial import

16 files changed, 9585 insertions, 0 deletions

diff --git a/net/sunrpc/auth_gss/Makefile b/net/sunrpc/auth_gss/Makefile
new file mode 100644
index 000000000..14e9e53e6
--- /dev/null
+++ b/net/sunrpc/auth_gss/Makefile
@@ -0,0 +1,14 @@
+#
+# Makefile for Linux kernel rpcsec_gss implementation
+#
+
+obj-$(CONFIG_SUNRPC_GSS) += auth_rpcgss.o
+
+auth_rpcgss-y := auth_gss.o gss_generic_token.o \
+	gss_mech_switch.o svcauth_gss.o \
+	gss_rpc_upcall.o gss_rpc_xdr.o
+
+obj-$(CONFIG_RPCSEC_GSS_KRB5) += rpcsec_gss_krb5.o
+
+rpcsec_gss_krb5-y := gss_krb5_mech.o gss_krb5_seal.o gss_krb5_unseal.o \
+	gss_krb5_seqnum.o gss_krb5_wrap.o gss_krb5_crypto.o gss_krb5_keys.o
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
new file mode 100644
index 000000000..dace13d76
--- /dev/null
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -0,0 +1,2097 @@
+/*
+ * linux/net/sunrpc/auth_gss/auth_gss.c
+ *
+ * RPCSEC_GSS client authentication.
+ *
+ *  Copyright (c) 2000 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Dug Song       <dugsong@monkey.org>
+ *  Andy Adamson   <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/pagemap.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/auth.h>
+#include <linux/sunrpc/auth_gss.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/gss_err.h>
+#include <linux/workqueue.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/sunrpc/gss_api.h>
+#include <asm/uaccess.h>
+#include <linux/hashtable.h>
+
+#include "../netns.h"
+
+static const struct rpc_authops authgss_ops;
+
+static const struct rpc_credops gss_credops;
+static const struct rpc_credops gss_nullops;
+
+#define GSS_RETRY_EXPIRED 5
+static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
+
+#define GSS_KEY_EXPIRE_TIMEO 240
+static unsigned int gss_key_expire_timeo = GSS_KEY_EXPIRE_TIMEO;
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_AUTH
+#endif
+
+#define GSS_CRED_SLACK		(RPC_MAX_AUTH_SIZE * 2)
+/* length of a krb5 verifier (48), plus data added before arguments when
+ * using integrity (two 4-byte integers): */
+#define GSS_VERF_SLACK		100
+
+static DEFINE_HASHTABLE(gss_auth_hash_table, 4);
+static DEFINE_SPINLOCK(gss_auth_hash_lock);
+
+struct gss_pipe {
+	struct rpc_pipe_dir_object pdo;
+	struct rpc_pipe *pipe;
+	struct rpc_clnt *clnt;
+	const char *name;
+	struct kref kref;
+};
+
+struct gss_auth {
+	struct kref kref;
+	struct hlist_node hash;
+	struct rpc_auth rpc_auth;
+	struct gss_api_mech *mech;
+	enum rpc_gss_svc service;
+	struct rpc_clnt *client;
+	struct net *net;
+	/*
+	 * There are two upcall pipes; dentry[1], named "gssd", is used
+	 * for the new text-based upcall; dentry[0] is named after the
+	 * mechanism (for example, "krb5") and exists for
+	 * backwards-compatibility with older gssd's.
+	 */
+	struct gss_pipe *gss_pipe[2];
+	const char *target_name;
+};
+
+/* pipe_version >= 0 if and only if someone has a pipe open. */
+static DEFINE_SPINLOCK(pipe_version_lock);
+static struct rpc_wait_queue pipe_version_rpc_waitqueue;
+static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
+static void gss_put_auth(struct gss_auth *gss_auth);
+
+static void gss_free_ctx(struct gss_cl_ctx *);
+static const struct rpc_pipe_ops gss_upcall_ops_v0;
+static const struct rpc_pipe_ops gss_upcall_ops_v1;
+
+static inline struct gss_cl_ctx *
+gss_get_ctx(struct gss_cl_ctx *ctx)
+{
+	atomic_inc(&ctx->count);
+	return ctx;
+}
+
+static inline void
+gss_put_ctx(struct gss_cl_ctx *ctx)
+{
+	if (atomic_dec_and_test(&ctx->count))
+		gss_free_ctx(ctx);
+}
+
+/* gss_cred_set_ctx:
+ * called by gss_upcall_callback and gss_create_upcall in order
+ * to set the gss context. The actual exchange of an old context
+ * and a new one is protected by the pipe->lock.
+ */
+static void
+gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
+{
+	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
+
+	if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
+		return;
+	gss_get_ctx(ctx);
+	rcu_assign_pointer(gss_cred->gc_ctx, ctx);
+	set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+	smp_mb__before_atomic();
+	clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
+}
+
+static const void *
+simple_get_bytes(const void *p, const void *end, void *res, size_t len)
+{
+	const void *q = (const void *)((const char *)p + len);
+	if (unlikely(q > end || q < p))
+		return ERR_PTR(-EFAULT);
+	memcpy(res, p, len);
+	return q;
+}
+
+static inline const void *
+simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
+{
+	const void *q;
+	unsigned int len;
+
+	p = simple_get_bytes(p, end, &len, sizeof(len));
+	if (IS_ERR(p))
+		return p;
+	q = (const void *)((const char *)p + len);
+	if (unlikely(q > end || q < p))
+		return ERR_PTR(-EFAULT);
+	dest->data = kmemdup(p, len, GFP_NOFS);
+	if (unlikely(dest->data == NULL))
+		return ERR_PTR(-ENOMEM);
+	dest->len = len;
+	return q;
+}
+
+static struct gss_cl_ctx *
+gss_cred_get_ctx(struct rpc_cred *cred)
+{
+	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
+	struct gss_cl_ctx *ctx = NULL;
+
+	rcu_read_lock();
+	ctx = rcu_dereference(gss_cred->gc_ctx);
+	if (ctx)
+		gss_get_ctx(ctx);
+	rcu_read_unlock();
+	return ctx;
+}
+
+static struct gss_cl_ctx *
+gss_alloc_context(void)
+{
+	struct gss_cl_ctx *ctx;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
+	if (ctx != NULL) {
+		ctx->gc_proc = RPC_GSS_PROC_DATA;
+		ctx->gc_seq = 1;	/* NetApp 6.4R1 doesn't accept seq. no. 0 */
+		spin_lock_init(&ctx->gc_seq_lock);
+		atomic_set(&ctx->count,1);
+	}
+	return ctx;
+}
+
+#define GSSD_MIN_TIMEOUT (60 * 60)
+static const void *
+gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
+{
+	const void *q;
+	unsigned int seclen;
+	unsigned int timeout;
+	unsigned long now = jiffies;
+	u32 window_size;
+	int ret;
+
+	/* First unsigned int gives the remaining lifetime in seconds of the
+	 * credential - e.g. the remaining TGT lifetime for Kerberos or
+	 * the -t value passed to GSSD.
+	 */
+	p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
+	if (IS_ERR(p))
+		goto err;
+	if (timeout == 0)
+		timeout = GSSD_MIN_TIMEOUT;
+	ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
+	/* Sequence number window. Determines the maximum number of
+	 * simultaneous requests
+	 */
+	p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
+	if (IS_ERR(p))
+		goto err;
+	ctx->gc_win = window_size;
+	/* gssd signals an error by passing ctx->gc_win = 0: */
+	if (ctx->gc_win == 0) {
+		/*
+		 * in which case, p points to an error code. Anything other
+		 * than -EKEYEXPIRED gets converted to -EACCES.
+		 */
+		p = simple_get_bytes(p, end, &ret, sizeof(ret));
+		if (!IS_ERR(p))
+			p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
+						    ERR_PTR(-EACCES);
+		goto err;
+	}
+	/* copy the opaque wire context */
+	p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
+	if (IS_ERR(p))
+		goto err;
+	/* import the opaque security context */
+	p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
+	if (IS_ERR(p))
+		goto err;
+	q = (const void *)((const char *)p + seclen);
+	if (unlikely(q > end || q < p)) {
+		p = ERR_PTR(-EFAULT);
+		goto err;
+	}
+	ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS);
+	if (ret < 0) {
+		p = ERR_PTR(ret);
+		goto err;
+	}
+
+	/* is there any trailing data? */
+	if (q == end) {
+		p = q;
+		goto done;
+	}
+
+	/* pull in acceptor name (if there is one) */
+	p = simple_get_netobj(q, end, &ctx->gc_acceptor);
+	if (IS_ERR(p))
+		goto err;
+done:
+	dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u acceptor %.*s\n",
+		__func__, ctx->gc_expiry, now, timeout, ctx->gc_acceptor.len,
+		ctx->gc_acceptor.data);
+	return p;
+err:
+	dprintk("RPC:       %s returns error %ld\n", __func__, -PTR_ERR(p));
+	return p;
+}
+
+#define UPCALL_BUF_LEN 128
+
+struct gss_upcall_msg {
+	atomic_t count;
+	kuid_t	uid;
+	struct rpc_pipe_msg msg;
+	struct list_head list;
+	struct gss_auth *auth;
+	struct rpc_pipe *pipe;
+	struct rpc_wait_queue rpc_waitqueue;
+	wait_queue_head_t waitqueue;
+	struct gss_cl_ctx *ctx;
+	char databuf[UPCALL_BUF_LEN];
+};
+
+static int get_pipe_version(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	int ret;
+
+	spin_lock(&pipe_version_lock);
+	if (sn->pipe_version >= 0) {
+		atomic_inc(&sn->pipe_users);
+		ret = sn->pipe_version;
+	} else
+		ret = -EAGAIN;
+	spin_unlock(&pipe_version_lock);
+	return ret;
+}
+
+static void put_pipe_version(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
+		sn->pipe_version = -1;
+		spin_unlock(&pipe_version_lock);
+	}
+}
+
+static void
+gss_release_msg(struct gss_upcall_msg *gss_msg)
+{
+	struct net *net = gss_msg->auth->net;
+	if (!atomic_dec_and_test(&gss_msg->count))
+		return;
+	put_pipe_version(net);
+	BUG_ON(!list_empty(&gss_msg->list));
+	if (gss_msg->ctx != NULL)
+		gss_put_ctx(gss_msg->ctx);
+	rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
+	gss_put_auth(gss_msg->auth);
+	kfree(gss_msg);
+}
+
+static struct gss_upcall_msg *
+__gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid)
+{
+	struct gss_upcall_msg *pos;
+	list_for_each_entry(pos, &pipe->in_downcall, list) {
+		if (!uid_eq(pos->uid, uid))
+			continue;
+		atomic_inc(&pos->count);
+		dprintk("RPC:       %s found msg %p\n", __func__, pos);
+		return pos;
+	}
+	dprintk("RPC:       %s found nothing\n", __func__);
+	return NULL;
+}
+
+/* Try to add an upcall to the pipefs queue.
+ * If an upcall owned by our uid already exists, then we return a reference
+ * to that upcall instead of adding the new upcall.
+ */
+static inline struct gss_upcall_msg *
+gss_add_msg(struct gss_upcall_msg *gss_msg)
+{
+	struct rpc_pipe *pipe = gss_msg->pipe;
+	struct gss_upcall_msg *old;
+
+	spin_lock(&pipe->lock);
+	old = __gss_find_upcall(pipe, gss_msg->uid);
+	if (old == NULL) {
+		atomic_inc(&gss_msg->count);
+		list_add(&gss_msg->list, &pipe->in_downcall);
+	} else
+		gss_msg = old;
+	spin_unlock(&pipe->lock);
+	return gss_msg;
+}
+
+static void
+__gss_unhash_msg(struct gss_upcall_msg *gss_msg)
+{
+	list_del_init(&gss_msg->list);
+	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
+	wake_up_all(&gss_msg->waitqueue);
+	atomic_dec(&gss_msg->count);
+}
+
+static void
+gss_unhash_msg(struct gss_upcall_msg *gss_msg)
+{
+	struct rpc_pipe *pipe = gss_msg->pipe;
+
+	if (list_empty(&gss_msg->list))
+		return;
+	spin_lock(&pipe->lock);
+	if (!list_empty(&gss_msg->list))
+		__gss_unhash_msg(gss_msg);
+	spin_unlock(&pipe->lock);
+}
+
+static void
+gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
+{
+	switch (gss_msg->msg.errno) {
+	case 0:
+		if (gss_msg->ctx == NULL)
+			break;
+		clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
+		gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
+		break;
+	case -EKEYEXPIRED:
+		set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
+	}
+	gss_cred->gc_upcall_timestamp = jiffies;
+	gss_cred->gc_upcall = NULL;
+	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
+}
+
+static void
+gss_upcall_callback(struct rpc_task *task)
+{
+	struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
+			struct gss_cred, gc_base);
+	struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
+	struct rpc_pipe *pipe = gss_msg->pipe;
+
+	spin_lock(&pipe->lock);
+	gss_handle_downcall_result(gss_cred, gss_msg);
+	spin_unlock(&pipe->lock);
+	task->tk_status = gss_msg->msg.errno;
+	gss_release_msg(gss_msg);
+}
+
+static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
+{
+	uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
+	memcpy(gss_msg->databuf, &uid, sizeof(uid));
+	gss_msg->msg.data = gss_msg->databuf;
+	gss_msg->msg.len = sizeof(uid);
+
+	BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
+}
+
+static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
+				const char *service_name,
+				const char *target_name)
+{
+	struct gss_api_mech *mech = gss_msg->auth->mech;
+	char *p = gss_msg->databuf;
+	size_t buflen = sizeof(gss_msg->databuf);
+	int len;
+
+	len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
+			from_kuid(&init_user_ns, gss_msg->uid));
+	buflen -= len;
+	p += len;
+	gss_msg->msg.len = len;
+	if (target_name) {
+		len = scnprintf(p, buflen, "target=%s ", target_name);
+		buflen -= len;
+		p += len;
+		gss_msg->msg.len += len;
+	}
+	if (service_name != NULL) {
+		len = scnprintf(p, buflen, "service=%s ", service_name);
+		buflen -= len;
+		p += len;
+		gss_msg->msg.len += len;
+	}
+	if (mech->gm_upcall_enctypes) {
+		len = scnprintf(p, buflen, "enctypes=%s ",
+				mech->gm_upcall_enctypes);
+		buflen -= len;
+		p += len;
+		gss_msg->msg.len += len;
+	}
+	len = scnprintf(p, buflen, "\n");
+	if (len == 0)
+		goto out_overflow;
+	gss_msg->msg.len += len;
+
+	gss_msg->msg.data = gss_msg->databuf;
+	return 0;
+out_overflow:
+	WARN_ON_ONCE(1);
+	return -ENOMEM;
+}
+
+static struct gss_upcall_msg *
+gss_alloc_msg(struct gss_auth *gss_auth,
+		kuid_t uid, const char *service_name)
+{
+	struct gss_upcall_msg *gss_msg;
+	int vers;
+	int err = -ENOMEM;
+
+	gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
+	if (gss_msg == NULL)
+		goto err;
+	vers = get_pipe_version(gss_auth->net);
+	err = vers;
+	if (err < 0)
+		goto err_free_msg;
+	gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
+	INIT_LIST_HEAD(&gss_msg->list);
+	rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
+	init_waitqueue_head(&gss_msg->waitqueue);
+	atomic_set(&gss_msg->count, 1);
+	gss_msg->uid = uid;
+	gss_msg->auth = gss_auth;
+	switch (vers) {
+	case 0:
+		gss_encode_v0_msg(gss_msg);
+		break;
+	default:
+		err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
+		if (err)
+			goto err_put_pipe_version;
+	};
+	kref_get(&gss_auth->kref);
+	return gss_msg;
+err_put_pipe_version:
+	put_pipe_version(gss_auth->net);
+err_free_msg:
+	kfree(gss_msg);
+err:
+	return ERR_PTR(err);
+}
+
+static struct gss_upcall_msg *
+gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
+{
+	struct gss_cred *gss_cred = container_of(cred,
+			struct gss_cred, gc_base);
+	struct gss_upcall_msg *gss_new, *gss_msg;
+	kuid_t uid = cred->cr_uid;
+
+	gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
+	if (IS_ERR(gss_new))
+		return gss_new;
+	gss_msg = gss_add_msg(gss_new);
+	if (gss_msg == gss_new) {
+		int res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
+		if (res) {
+			gss_unhash_msg(gss_new);
+			gss_msg = ERR_PTR(res);
+		}
+	} else
+		gss_release_msg(gss_new);
+	return gss_msg;
+}
+
+static void warn_gssd(void)
+{
+	dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
+}
+
+static inline int
+gss_refresh_upcall(struct rpc_task *task)
+{
+	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
+	struct gss_auth *gss_auth = container_of(cred->cr_auth,
+			struct gss_auth, rpc_auth);
+	struct gss_cred *gss_cred = container_of(cred,
+			struct gss_cred, gc_base);
+	struct gss_upcall_msg *gss_msg;
+	struct rpc_pipe *pipe;
+	int err = 0;
+
+	dprintk("RPC: %5u %s for uid %u\n",
+		task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
+	gss_msg = gss_setup_upcall(gss_auth, cred);
+	if (PTR_ERR(gss_msg) == -EAGAIN) {
+		/* XXX: warning on the first, under the assumption we
+		 * shouldn't normally hit this case on a refresh. */
+		warn_gssd();
+		task->tk_timeout = 15*HZ;
+		rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
+		return -EAGAIN;
+	}
+	if (IS_ERR(gss_msg)) {
+		err = PTR_ERR(gss_msg);
+		goto out;
+	}
+	pipe = gss_msg->pipe;
+	spin_lock(&pipe->lock);
+	if (gss_cred->gc_upcall != NULL)
+		rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
+	else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
+		task->tk_timeout = 0;
+		gss_cred->gc_upcall = gss_msg;
+		/* gss_upcall_callback will release the reference to gss_upcall_msg */
+		atomic_inc(&gss_msg->count);
+		rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
+	} else {
+		gss_handle_downcall_result(gss_cred, gss_msg);
+		err = gss_msg->msg.errno;
+	}
+	spin_unlock(&pipe->lock);
+	gss_release_msg(gss_msg);
+out:
+	dprintk("RPC: %5u %s for uid %u result %d\n",
+		task->tk_pid, __func__,
+		from_kuid(&init_user_ns, cred->cr_uid),	err);
+	return err;
+}
+
+static inline int
+gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
+{
+	struct net *net = gss_auth->net;
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct rpc_pipe *pipe;
+	struct rpc_cred *cred = &gss_cred->gc_base;
+	struct gss_upcall_msg *gss_msg;
+	DEFINE_WAIT(wait);
+	int err;
+
+	dprintk("RPC:       %s for uid %u\n",
+		__func__, from_kuid(&init_user_ns, cred->cr_uid));
+retry:
+	err = 0;
+	/* if gssd is down, just skip upcalling altogether */
+	if (!gssd_running(net)) {
+		warn_gssd();
+		return -EACCES;
+	}
+	gss_msg = gss_setup_upcall(gss_auth, cred);
+	if (PTR_ERR(gss_msg) == -EAGAIN) {
+		err = wait_event_interruptible_timeout(pipe_version_waitqueue,
+				sn->pipe_version >= 0, 15 * HZ);
+		if (sn->pipe_version < 0) {
+			warn_gssd();
+			err = -EACCES;
+		}
+		if (err < 0)
+			goto out;
+		goto retry;
+	}
+	if (IS_ERR(gss_msg)) {
+		err = PTR_ERR(gss_msg);
+		goto out;
+	}
+	pipe = gss_msg->pipe;
+	for (;;) {
+		prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
+		spin_lock(&pipe->lock);
+		if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
+			break;
+		}
+		spin_unlock(&pipe->lock);
+		if (fatal_signal_pending(current)) {
+			err = -ERESTARTSYS;
+			goto out_intr;
+		}
+		schedule();
+	}
+	if (gss_msg->ctx)
+		gss_cred_set_ctx(cred, gss_msg->ctx);
+	else
+		err = gss_msg->msg.errno;
+	spin_unlock(&pipe->lock);
+out_intr:
+	finish_wait(&gss_msg->waitqueue, &wait);
+	gss_release_msg(gss_msg);
+out:
+	dprintk("RPC:       %s for uid %u result %d\n",
+		__func__, from_kuid(&init_user_ns, cred->cr_uid), err);
+	return err;
+}
+
+#define MSG_BUF_MAXSIZE 1024
+
+static ssize_t
+gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
+{
+	const void *p, *end;
+	void *buf;
+	struct gss_upcall_msg *gss_msg;
+	struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
+	struct gss_cl_ctx *ctx;
+	uid_t id;
+	kuid_t uid;
+	ssize_t err = -EFBIG;
+
+	if (mlen > MSG_BUF_MAXSIZE)
+		goto out;
+	err = -ENOMEM;
+	buf = kmalloc(mlen, GFP_NOFS);
+	if (!buf)
+		goto out;
+
+	err = -EFAULT;
+	if (copy_from_user(buf, src, mlen))
+		goto err;
+
+	end = (const void *)((char *)buf + mlen);
+	p = simple_get_bytes(buf, end, &id, sizeof(id));
+	if (IS_ERR(p)) {
+		err = PTR_ERR(p);
+		goto err;
+	}
+
+	uid = make_kuid(&init_user_ns, id);
+	if (!uid_valid(uid)) {
+		err = -EINVAL;
+		goto err;
+	}
+
+	err = -ENOMEM;
+	ctx = gss_alloc_context();
+	if (ctx == NULL)
+		goto err;
+
+	err = -ENOENT;
+	/* Find a matching upcall */
+	spin_lock(&pipe->lock);
+	gss_msg = __gss_find_upcall(pipe, uid);
+	if (gss_msg == NULL) {
+		spin_unlock(&pipe->lock);
+		goto err_put_ctx;
+	}
+	list_del_init(&gss_msg->list);
+	spin_unlock(&pipe->lock);
+
+	p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
+	if (IS_ERR(p)) {
+		err = PTR_ERR(p);
+		switch (err) {
+		case -EACCES:
+		case -EKEYEXPIRED:
+			gss_msg->msg.errno = err;
+			err = mlen;
+			break;
+		case -EFAULT:
+		case -ENOMEM:
+		case -EINVAL:
+		case -ENOSYS:
+			gss_msg->msg.errno = -EAGAIN;
+			break;
+		default:
+			printk(KERN_CRIT "%s: bad return from "
+				"gss_fill_context: %zd\n", __func__, err);
+			BUG();
+		}
+		goto err_release_msg;
+	}
+	gss_msg->ctx = gss_get_ctx(ctx);
+	err = mlen;
+
+err_release_msg:
+	spin_lock(&pipe->lock);
+	__gss_unhash_msg(gss_msg);
+	spin_unlock(&pipe->lock);
+	gss_release_msg(gss_msg);
+err_put_ctx:
+	gss_put_ctx(ctx);
+err:
+	kfree(buf);
+out:
+	dprintk("RPC:       %s returning %Zd\n", __func__, err);
+	return err;
+}
+
+static int gss_pipe_open(struct inode *inode, int new_version)
+{
+	struct net *net = inode->i_sb->s_fs_info;
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	int ret = 0;
+
+	spin_lock(&pipe_version_lock);
+	if (sn->pipe_version < 0) {
+		/* First open of any gss pipe determines the version: */
+		sn->pipe_version = new_version;
+		rpc_wake_up(&pipe_version_rpc_waitqueue);
+		wake_up(&pipe_version_waitqueue);
+	} else if (sn->pipe_version != new_version) {
+		/* Trying to open a pipe of a different version */
+		ret = -EBUSY;
+		goto out;
+	}
+	atomic_inc(&sn->pipe_users);
+out:
+	spin_unlock(&pipe_version_lock);
+	return ret;
+
+}
+
+static int gss_pipe_open_v0(struct inode *inode)
+{
+	return gss_pipe_open(inode, 0);
+}
+
+static int gss_pipe_open_v1(struct inode *inode)
+{
+	return gss_pipe_open(inode, 1);
+}
+
+static void
+gss_pipe_release(struct inode *inode)
+{
+	struct net *net = inode->i_sb->s_fs_info;
+	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
+	struct gss_upcall_msg *gss_msg;
+
+restart:
+	spin_lock(&pipe->lock);
+	list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
+
+		if (!list_empty(&gss_msg->msg.list))
+			continue;
+		gss_msg->msg.errno = -EPIPE;
+		atomic_inc(&gss_msg->count);
+		__gss_unhash_msg(gss_msg);
+		spin_unlock(&pipe->lock);
+		gss_release_msg(gss_msg);
+		goto restart;
+	}
+	spin_unlock(&pipe->lock);
+
+	put_pipe_version(net);
+}
+
+static void
+gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
+{
+	struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
+
+	if (msg->errno < 0) {
+		dprintk("RPC:       %s releasing msg %p\n",
+			__func__, gss_msg);
+		atomic_inc(&gss_msg->count);
+		gss_unhash_msg(gss_msg);
+		if (msg->errno == -ETIMEDOUT)
+			warn_gssd();
+		gss_release_msg(gss_msg);
+	}
+}
+
+static void gss_pipe_dentry_destroy(struct dentry *dir,
+		struct rpc_pipe_dir_object *pdo)
+{
+	struct gss_pipe *gss_pipe = pdo->pdo_data;
+	struct rpc_pipe *pipe = gss_pipe->pipe;
+
+	if (pipe->dentry != NULL) {
+		rpc_unlink(pipe->dentry);
+		pipe->dentry = NULL;
+	}
+}
+
+static int gss_pipe_dentry_create(struct dentry *dir,
+		struct rpc_pipe_dir_object *pdo)
+{
+	struct gss_pipe *p = pdo->pdo_data;
+	struct dentry *dentry;
+
+	dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+	p->pipe->dentry = dentry;
+	return 0;
+}
+
+static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
+	.create = gss_pipe_dentry_create,
+	.destroy = gss_pipe_dentry_destroy,
+};
+
+static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
+		const char *name,
+		const struct rpc_pipe_ops *upcall_ops)
+{
+	struct gss_pipe *p;
+	int err = -ENOMEM;
+
+	p = kmalloc(sizeof(*p), GFP_KERNEL);
+	if (p == NULL)
+		goto err;
+	p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
+	if (IS_ERR(p->pipe)) {
+		err = PTR_ERR(p->pipe);
+		goto err_free_gss_pipe;
+	}
+	p->name = name;
+	p->clnt = clnt;
+	kref_init(&p->kref);
+	rpc_init_pipe_dir_object(&p->pdo,
+			&gss_pipe_dir_object_ops,
+			p);
+	return p;
+err_free_gss_pipe:
+	kfree(p);
+err:
+	return ERR_PTR(err);
+}
+
+struct gss_alloc_pdo {
+	struct rpc_clnt *clnt;
+	const char *name;
+	const struct rpc_pipe_ops *upcall_ops;
+};
+
+static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
+{
+	struct gss_pipe *gss_pipe;
+	struct gss_alloc_pdo *args = data;
+
+	if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
+		return 0;
+	gss_pipe = container_of(pdo, struct gss_pipe, pdo);
+	if (strcmp(gss_pipe->name, args->name) != 0)
+		return 0;
+	if (!kref_get_unless_zero(&gss_pipe->kref))
+		return 0;
+	return 1;
+}
+
+static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
+{
+	struct gss_pipe *gss_pipe;
+	struct gss_alloc_pdo *args = data;
+
+	gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
+	if (!IS_ERR(gss_pipe))
+		return &gss_pipe->pdo;
+	return NULL;
+}
+
+static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
+		const char *name,
+		const struct rpc_pipe_ops *upcall_ops)
+{
+	struct net *net = rpc_net_ns(clnt);
+	struct rpc_pipe_dir_object *pdo;
+	struct gss_alloc_pdo args = {
+		.clnt = clnt,
+		.name = name,
+		.upcall_ops = upcall_ops,
+	};
+
+	pdo = rpc_find_or_alloc_pipe_dir_object(net,
+			&clnt->cl_pipedir_objects,
+			gss_pipe_match_pdo,
+			gss_pipe_alloc_pdo,
+			&args);
+	if (pdo != NULL)
+		return container_of(pdo, struct gss_pipe, pdo);
+	return ERR_PTR(-ENOMEM);
+}
+
+static void __gss_pipe_free(struct gss_pipe *p)
+{
+	struct rpc_clnt *clnt = p->clnt;
+	struct net *net = rpc_net_ns(clnt);
+
+	rpc_remove_pipe_dir_object(net,
+			&clnt->cl_pipedir_objects,
+			&p->pdo);
+	rpc_destroy_pipe_data(p->pipe);
+	kfree(p);
+}
+
+static void __gss_pipe_release(struct kref *kref)
+{
+	struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
+
+	__gss_pipe_free(p);
+}
+
+static void gss_pipe_free(struct gss_pipe *p)
+{
+	if (p != NULL)
+		kref_put(&p->kref, __gss_pipe_release);
+}
+
+/*
+ * NOTE: we have the opportunity to use different
+ * parameters based on the input flavor (which must be a pseudoflavor)
+ */
+static struct gss_auth *
+gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
+{
+	rpc_authflavor_t flavor = args->pseudoflavor;
+	struct gss_auth *gss_auth;
+	struct gss_pipe *gss_pipe;
+	struct rpc_auth * auth;
+	int err = -ENOMEM; /* XXX? */
+
+	dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
+
+	if (!try_module_get(THIS_MODULE))
+		return ERR_PTR(err);
+	if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
+		goto out_dec;
+	INIT_HLIST_NODE(&gss_auth->hash);
+	gss_auth->target_name = NULL;
+	if (args->target_name) {
+		gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
+		if (gss_auth->target_name == NULL)
+			goto err_free;
+	}
+	gss_auth->client = clnt;
+	gss_auth->net = get_net(rpc_net_ns(clnt));
+	err = -EINVAL;
+	gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
+	if (!gss_auth->mech) {
+		dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
+		goto err_put_net;
+	}
+	gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
+	if (gss_auth->service == 0)
+		goto err_put_mech;
+	if (!gssd_running(gss_auth->net))
+		goto err_put_mech;
+	auth = &gss_auth->rpc_auth;
+	auth->au_cslack = GSS_CRED_SLACK >> 2;
+	auth->au_rslack = GSS_VERF_SLACK >> 2;
+	auth->au_ops = &authgss_ops;
+	auth->au_flavor = flavor;
+	atomic_set(&auth->au_count, 1);
+	kref_init(&gss_auth->kref);
+
+	err = rpcauth_init_credcache(auth);
+	if (err)
+		goto err_put_mech;
+	/*
+	 * Note: if we created the old pipe first, then someone who
+	 * examined the directory at the right moment might conclude
+	 * that we supported only the old pipe.  So we instead create
+	 * the new pipe first.
+	 */
+	gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
+	if (IS_ERR(gss_pipe)) {
+		err = PTR_ERR(gss_pipe);
+		goto err_destroy_credcache;
+	}
+	gss_auth->gss_pipe[1] = gss_pipe;
+
+	gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
+			&gss_upcall_ops_v0);
+	if (IS_ERR(gss_pipe)) {
+		err = PTR_ERR(gss_pipe);
+		goto err_destroy_pipe_1;
+	}
+	gss_auth->gss_pipe[0] = gss_pipe;
+
+	return gss_auth;
+err_destroy_pipe_1:
+	gss_pipe_free(gss_auth->gss_pipe[1]);
+err_destroy_credcache:
+	rpcauth_destroy_credcache(auth);
+err_put_mech:
+	gss_mech_put(gss_auth->mech);
+err_put_net:
+	put_net(gss_auth->net);
+err_free:
+	kfree(gss_auth->target_name);
+	kfree(gss_auth);
+out_dec:
+	module_put(THIS_MODULE);
+	return ERR_PTR(err);
+}
+
+static void
+gss_free(struct gss_auth *gss_auth)
+{
+	gss_pipe_free(gss_auth->gss_pipe[0]);
+	gss_pipe_free(gss_auth->gss_pipe[1]);
+	gss_mech_put(gss_auth->mech);
+	put_net(gss_auth->net);
+	kfree(gss_auth->target_name);
+
+	kfree(gss_auth);
+	module_put(THIS_MODULE);
+}
+
+static void
+gss_free_callback(struct kref *kref)
+{
+	struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
+
+	gss_free(gss_auth);
+}
+
+static void
+gss_put_auth(struct gss_auth *gss_auth)
+{
+	kref_put(&gss_auth->kref, gss_free_callback);
+}
+
+static void
+gss_destroy(struct rpc_auth *auth)
+{
+	struct gss_auth *gss_auth = container_of(auth,
+			struct gss_auth, rpc_auth);
+
+	dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
+			auth, auth->au_flavor);
+
+	if (hash_hashed(&gss_auth->hash)) {
+		spin_lock(&gss_auth_hash_lock);
+		hash_del(&gss_auth->hash);
+		spin_unlock(&gss_auth_hash_lock);
+	}
+
+	gss_pipe_free(gss_auth->gss_pipe[0]);
+	gss_auth->gss_pipe[0] = NULL;
+	gss_pipe_free(gss_auth->gss_pipe[1]);
+	gss_auth->gss_pipe[1] = NULL;
+	rpcauth_destroy_credcache(auth);
+
+	gss_put_auth(gss_auth);
+}
+
+/*
+ * Auths may be shared between rpc clients that were cloned from a
+ * common client with the same xprt, if they also share the flavor and
+ * target_name.
+ *
+ * The auth is looked up from the oldest parent sharing the same
+ * cl_xprt, and the auth itself references only that common parent
+ * (which is guaranteed to last as long as any of its descendants).
+ */
+static struct gss_auth *
+gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
+		struct rpc_clnt *clnt,
+		struct gss_auth *new)
+{
+	struct gss_auth *gss_auth;
+	unsigned long hashval = (unsigned long)clnt;
+
+	spin_lock(&gss_auth_hash_lock);
+	hash_for_each_possible(gss_auth_hash_table,
+			gss_auth,
+			hash,
+			hashval) {
+		if (gss_auth->client != clnt)
+			continue;
+		if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
+			continue;
+		if (gss_auth->target_name != args->target_name) {
+			if (gss_auth->target_name == NULL)
+				continue;
+			if (args->target_name == NULL)
+				continue;
+			if (strcmp(gss_auth->target_name, args->target_name))
+				continue;
+		}
+		if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
+			continue;
+		goto out;
+	}
+	if (new)
+		hash_add(gss_auth_hash_table, &new->hash, hashval);
+	gss_auth = new;
+out:
+	spin_unlock(&gss_auth_hash_lock);
+	return gss_auth;
+}
+
+static struct gss_auth *
+gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
+{
+	struct gss_auth *gss_auth;
+	struct gss_auth *new;
+
+	gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
+	if (gss_auth != NULL)
+		goto out;
+	new = gss_create_new(args, clnt);
+	if (IS_ERR(new))
+		return new;
+	gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
+	if (gss_auth != new)
+		gss_destroy(&new->rpc_auth);
+out:
+	return gss_auth;
+}
+
+static struct rpc_auth *
+gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
+{
+	struct gss_auth *gss_auth;
+	struct rpc_xprt *xprt = rcu_access_pointer(clnt->cl_xprt);
+
+	while (clnt != clnt->cl_parent) {
+		struct rpc_clnt *parent = clnt->cl_parent;
+		/* Find the original parent for this transport */
+		if (rcu_access_pointer(parent->cl_xprt) != xprt)
+			break;
+		clnt = parent;
+	}
+
+	gss_auth = gss_create_hashed(args, clnt);
+	if (IS_ERR(gss_auth))
+		return ERR_CAST(gss_auth);
+	return &gss_auth->rpc_auth;
+}
+
+/*
+ * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
+ * to the server with the GSS control procedure field set to
+ * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
+ * all RPCSEC_GSS state associated with that context.
+ */
+static int
+gss_destroying_context(struct rpc_cred *cred)
+{
+	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
+	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
+	struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
+	struct rpc_task *task;
+
+	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
+		return 0;
+
+	ctx->gc_proc = RPC_GSS_PROC_DESTROY;
+	cred->cr_ops = &gss_nullops;
+
+	/* Take a reference to ensure the cred will be destroyed either
+	 * by the RPC call or by the put_rpccred() below */
+	get_rpccred(cred);
+
+	task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
+	if (!IS_ERR(task))
+		rpc_put_task(task);
+
+	put_rpccred(cred);
+	return 1;
+}
+
+/* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
+ * to create a new cred or context, so they check that things have been
+ * allocated before freeing them. */
+static void
+gss_do_free_ctx(struct gss_cl_ctx *ctx)
+{
+	dprintk("RPC:       %s\n", __func__);
+
+	gss_delete_sec_context(&ctx->gc_gss_ctx);
+	kfree(ctx->gc_wire_ctx.data);
+	kfree(ctx->gc_acceptor.data);
+	kfree(ctx);
+}
+
+static void
+gss_free_ctx_callback(struct rcu_head *head)
+{
+	struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
+	gss_do_free_ctx(ctx);
+}
+
+static void
+gss_free_ctx(struct gss_cl_ctx *ctx)
+{
+	call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
+}
+
+static void
+gss_free_cred(struct gss_cred *gss_cred)
+{
+	dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
+	kfree(gss_cred);
+}
+
+static void
+gss_free_cred_callback(struct rcu_head *head)
+{
+	struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
+	gss_free_cred(gss_cred);
+}
+
+static void
+gss_destroy_nullcred(struct rpc_cred *cred)
+{
+	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
+	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
+	struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
+
+	RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
+	call_rcu(&cred->cr_rcu, gss_free_cred_callback);
+	if (ctx)
+		gss_put_ctx(ctx);
+	gss_put_auth(gss_auth);
+}
+
+static void
+gss_destroy_cred(struct rpc_cred *cred)
+{
+
+	if (gss_destroying_context(cred))
+		return;
+	gss_destroy_nullcred(cred);
+}
+
+/*
+ * Lookup RPCSEC_GSS cred for the current process
+ */
+static struct rpc_cred *
+gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
+{
+	return rpcauth_lookup_credcache(auth, acred, flags);
+}
+
+static struct rpc_cred *
+gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
+{
+	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
+	struct gss_cred	*cred = NULL;
+	int err = -ENOMEM;
+
+	dprintk("RPC:       %s for uid %d, flavor %d\n",
+		__func__, from_kuid(&init_user_ns, acred->uid),
+		auth->au_flavor);
+
+	if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
+		goto out_err;
+
+	rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
+	/*
+	 * Note: in order to force a call to call_refresh(), we deliberately
+	 * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
+	 */
+	cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
+	cred->gc_service = gss_auth->service;
+	cred->gc_principal = NULL;
+	if (acred->machine_cred)
+		cred->gc_principal = acred->principal;
+	kref_get(&gss_auth->kref);
+	return &cred->gc_base;
+
+out_err:
+	dprintk("RPC:       %s failed with error %d\n", __func__, err);
+	return ERR_PTR(err);
+}
+
+static int
+gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
+{
+	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
+	struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
+	int err;
+
+	do {
+		err = gss_create_upcall(gss_auth, gss_cred);
+	} while (err == -EAGAIN);
+	return err;
+}
+
+static char *
+gss_stringify_acceptor(struct rpc_cred *cred)
+{
+	char *string = NULL;
+	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
+	struct gss_cl_ctx *ctx;
+	unsigned int len;
+	struct xdr_netobj *acceptor;
+
+	rcu_read_lock();
+	ctx = rcu_dereference(gss_cred->gc_ctx);
+	if (!ctx)
+		goto out;
+
+	len = ctx->gc_acceptor.len;
+	rcu_read_unlock();
+
+	/* no point if there's no string */
+	if (!len)
+		return NULL;
+realloc:
+	string = kmalloc(len + 1, GFP_KERNEL);
+	if (!string)
+		return NULL;
+
+	rcu_read_lock();
+	ctx = rcu_dereference(gss_cred->gc_ctx);
+
+	/* did the ctx disappear or was it replaced by one with no acceptor? */
+	if (!ctx || !ctx->gc_acceptor.len) {
+		kfree(string);
+		string = NULL;
+		goto out;
+	}
+
+	acceptor = &ctx->gc_acceptor;
+
+	/*
+	 * Did we find a new acceptor that's longer than the original? Allocate
+	 * a longer buffer and try again.
+	 */
+	if (len < acceptor->len) {
+		len = acceptor->len;
+		rcu_read_unlock();
+		kfree(string);
+		goto realloc;
+	}
+
+	memcpy(string, acceptor->data, acceptor->len);
+	string[acceptor->len] = '\0';
+out:
+	rcu_read_unlock();
+	return string;
+}
+
+/*
+ * Returns -EACCES if GSS context is NULL or will expire within the
+ * timeout (miliseconds)
+ */
+static int
+gss_key_timeout(struct rpc_cred *rc)
+{
+	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
+	struct gss_cl_ctx *ctx;
+	unsigned long now = jiffies;
+	unsigned long expire;
+
+	rcu_read_lock();
+	ctx = rcu_dereference(gss_cred->gc_ctx);
+	if (ctx)
+		expire = ctx->gc_expiry - (gss_key_expire_timeo * HZ);
+	rcu_read_unlock();
+	if (!ctx || time_after(now, expire))
+		return -EACCES;
+	return 0;
+}
+
+static int
+gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
+{
+	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
+	struct gss_cl_ctx *ctx;
+	int ret;
+
+	if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
+		goto out;
+	/* Don't match with creds that have expired. */
+	rcu_read_lock();
+	ctx = rcu_dereference(gss_cred->gc_ctx);
+	if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
+		rcu_read_unlock();
+		return 0;
+	}
+	rcu_read_unlock();
+	if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
+		return 0;
+out:
+	if (acred->principal != NULL) {
+		if (gss_cred->gc_principal == NULL)
+			return 0;
+		ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
+		goto check_expire;
+	}
+	if (gss_cred->gc_principal != NULL)
+		return 0;
+	ret = uid_eq(rc->cr_uid, acred->uid);
+
+check_expire:
+	if (ret == 0)
+		return ret;
+
+	/* Notify acred users of GSS context expiration timeout */
+	if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
+	    (gss_key_timeout(rc) != 0)) {
+		/* test will now be done from generic cred */
+		test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
+		/* tell NFS layer that key will expire soon */
+		set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
+	}
+	return ret;
+}
+
+/*
+* Marshal credentials.
+* Maybe we should keep a cached credential for performance reasons.
+*/
+static __be32 *
+gss_marshal(struct rpc_task *task, __be32 *p)
+{
+	struct rpc_rqst *req = task->tk_rqstp;
+	struct rpc_cred *cred = req->rq_cred;
+	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
+						 gc_base);
+	struct gss_cl_ctx	*ctx = gss_cred_get_ctx(cred);
+	__be32		*cred_len;
+	u32             maj_stat = 0;
+	struct xdr_netobj mic;
+	struct kvec	iov;
+	struct xdr_buf	verf_buf;
+
+	dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
+
+	*p++ = htonl(RPC_AUTH_GSS);
+	cred_len = p++;
+
+	spin_lock(&ctx->gc_seq_lock);
+	req->rq_seqno = ctx->gc_seq++;
+	spin_unlock(&ctx->gc_seq_lock);
+
+	*p++ = htonl((u32) RPC_GSS_VERSION);
+	*p++ = htonl((u32) ctx->gc_proc);
+	*p++ = htonl((u32) req->rq_seqno);
+	*p++ = htonl((u32) gss_cred->gc_service);
+	p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
+	*cred_len = htonl((p - (cred_len + 1)) << 2);
+
+	/* We compute the checksum for the verifier over the xdr-encoded bytes
+	 * starting with the xid and ending at the end of the credential: */
+	iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
+					req->rq_snd_buf.head[0].iov_base);
+	iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
+	xdr_buf_from_iov(&iov, &verf_buf);
+
+	/* set verifier flavor*/
+	*p++ = htonl(RPC_AUTH_GSS);
+
+	mic.data = (u8 *)(p + 1);
+	maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
+	if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
+		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+	} else if (maj_stat != 0) {
+		printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
+		goto out_put_ctx;
+	}
+	p = xdr_encode_opaque(p, NULL, mic.len);
+	gss_put_ctx(ctx);
+	return p;
+out_put_ctx:
+	gss_put_ctx(ctx);
+	return NULL;
+}
+
+static int gss_renew_cred(struct rpc_task *task)
+{
+	struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
+	struct gss_cred *gss_cred = container_of(oldcred,
+						 struct gss_cred,
+						 gc_base);
+	struct rpc_auth *auth = oldcred->cr_auth;
+	struct auth_cred acred = {
+		.uid = oldcred->cr_uid,
+		.principal = gss_cred->gc_principal,
+		.machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
+	};
+	struct rpc_cred *new;
+
+	new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
+	if (IS_ERR(new))
+		return PTR_ERR(new);
+	task->tk_rqstp->rq_cred = new;
+	put_rpccred(oldcred);
+	return 0;
+}
+
+static int gss_cred_is_negative_entry(struct rpc_cred *cred)
+{
+	if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
+		unsigned long now = jiffies;
+		unsigned long begin, expire;
+		struct gss_cred *gss_cred; 
+
+		gss_cred = container_of(cred, struct gss_cred, gc_base);
+		begin = gss_cred->gc_upcall_timestamp;
+		expire = begin + gss_expired_cred_retry_delay * HZ;
+
+		if (time_in_range_open(now, begin, expire))
+			return 1;
+	}
+	return 0;
+}
+
+/*
+* Refresh credentials. XXX - finish
+*/
+static int
+gss_refresh(struct rpc_task *task)
+{
+	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
+	int ret = 0;
+
+	if (gss_cred_is_negative_entry(cred))
+		return -EKEYEXPIRED;
+
+	if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
+			!test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
+		ret = gss_renew_cred(task);
+		if (ret < 0)
+			goto out;
+		cred = task->tk_rqstp->rq_cred;
+	}
+
+	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
+		ret = gss_refresh_upcall(task);
+out:
+	return ret;
+}
+
+/* Dummy refresh routine: used only when destroying the context */
+static int
+gss_refresh_null(struct rpc_task *task)
+{
+	return 0;
+}
+
+static __be32 *
+gss_validate(struct rpc_task *task, __be32 *p)
+{
+	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
+	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
+	__be32		seq;
+	struct kvec	iov;
+	struct xdr_buf	verf_buf;
+	struct xdr_netobj mic;
+	u32		flav,len;
+	u32		maj_stat;
+	__be32		*ret = ERR_PTR(-EIO);
+
+	dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
+
+	flav = ntohl(*p++);
+	if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
+		goto out_bad;
+	if (flav != RPC_AUTH_GSS)
+		goto out_bad;
+	seq = htonl(task->tk_rqstp->rq_seqno);
+	iov.iov_base = &seq;
+	iov.iov_len = sizeof(seq);
+	xdr_buf_from_iov(&iov, &verf_buf);
+	mic.data = (u8 *)p;
+	mic.len = len;
+
+	ret = ERR_PTR(-EACCES);
+	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
+	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
+		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+	if (maj_stat) {
+		dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
+			task->tk_pid, __func__, maj_stat);
+		goto out_bad;
+	}
+	/* We leave it to unwrap to calculate au_rslack. For now we just
+	 * calculate the length of the verifier: */
+	cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
+	gss_put_ctx(ctx);
+	dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
+			task->tk_pid, __func__);
+	return p + XDR_QUADLEN(len);
+out_bad:
+	gss_put_ctx(ctx);
+	dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
+		PTR_ERR(ret));
+	return ret;
+}
+
+static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
+				__be32 *p, void *obj)
+{
+	struct xdr_stream xdr;
+
+	xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
+	encode(rqstp, &xdr, obj);
+}
+
+static inline int
+gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
+		   kxdreproc_t encode, struct rpc_rqst *rqstp,
+		   __be32 *p, void *obj)
+{
+	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
+	struct xdr_buf	integ_buf;
+	__be32          *integ_len = NULL;
+	struct xdr_netobj mic;
+	u32		offset;
+	__be32		*q;
+	struct kvec	*iov;
+	u32             maj_stat = 0;
+	int		status = -EIO;
+
+	integ_len = p++;
+	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
+	*p++ = htonl(rqstp->rq_seqno);
+
+	gss_wrap_req_encode(encode, rqstp, p, obj);
+
+	if (xdr_buf_subsegment(snd_buf, &integ_buf,
+				offset, snd_buf->len - offset))
+		return status;
+	*integ_len = htonl(integ_buf.len);
+
+	/* guess whether we're in the head or the tail: */
+	if (snd_buf->page_len || snd_buf->tail[0].iov_len)
+		iov = snd_buf->tail;
+	else
+		iov = snd_buf->head;
+	p = iov->iov_base + iov->iov_len;
+	mic.data = (u8 *)(p + 1);
+
+	maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
+	status = -EIO; /* XXX? */
+	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
+		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+	else if (maj_stat)
+		return status;
+	q = xdr_encode_opaque(p, NULL, mic.len);
+
+	offset = (u8 *)q - (u8 *)p;
+	iov->iov_len += offset;
+	snd_buf->len += offset;
+	return 0;
+}
+
+static void
+priv_release_snd_buf(struct rpc_rqst *rqstp)
+{
+	int i;
+
+	for (i=0; i < rqstp->rq_enc_pages_num; i++)
+		__free_page(rqstp->rq_enc_pages[i]);
+	kfree(rqstp->rq_enc_pages);
+}
+
+static int
+alloc_enc_pages(struct rpc_rqst *rqstp)
+{
+	struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
+	int first, last, i;
+
+	if (snd_buf->page_len == 0) {
+		rqstp->rq_enc_pages_num = 0;
+		return 0;
+	}
+
+	first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
+	last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
+	rqstp->rq_enc_pages_num = last - first + 1 + 1;
+	rqstp->rq_enc_pages
+		= kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
+				GFP_NOFS);
+	if (!rqstp->rq_enc_pages)
+		goto out;
+	for (i=0; i < rqstp->rq_enc_pages_num; i++) {
+		rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
+		if (rqstp->rq_enc_pages[i] == NULL)
+			goto out_free;
+	}
+	rqstp->rq_release_snd_buf = priv_release_snd_buf;
+	return 0;
+out_free:
+	rqstp->rq_enc_pages_num = i;
+	priv_release_snd_buf(rqstp);
+out:
+	return -EAGAIN;
+}
+
+static inline int
+gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
+		  kxdreproc_t encode, struct rpc_rqst *rqstp,
+		  __be32 *p, void *obj)
+{
+	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
+	u32		offset;
+	u32             maj_stat;
+	int		status;
+	__be32		*opaque_len;
+	struct page	**inpages;
+	int		first;
+	int		pad;
+	struct kvec	*iov;
+	char		*tmp;
+
+	opaque_len = p++;
+	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
+	*p++ = htonl(rqstp->rq_seqno);
+
+	gss_wrap_req_encode(encode, rqstp, p, obj);
+
+	status = alloc_enc_pages(rqstp);
+	if (status)
+		return status;
+	first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
+	inpages = snd_buf->pages + first;
+	snd_buf->pages = rqstp->rq_enc_pages;
+	snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
+	/*
+	 * Give the tail its own page, in case we need extra space in the
+	 * head when wrapping:
+	 *
+	 * call_allocate() allocates twice the slack space required
+	 * by the authentication flavor to rq_callsize.
+	 * For GSS, slack is GSS_CRED_SLACK.
+	 */
+	if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
+		tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
+		memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
+		snd_buf->tail[0].iov_base = tmp;
+	}
+	maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
+	/* slack space should prevent this ever happening: */
+	BUG_ON(snd_buf->len > snd_buf->buflen);
+	status = -EIO;
+	/* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
+	 * done anyway, so it's safe to put the request on the wire: */
+	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
+		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+	else if (maj_stat)
+		return status;
+
+	*opaque_len = htonl(snd_buf->len - offset);
+	/* guess whether we're in the head or the tail: */
+	if (snd_buf->page_len || snd_buf->tail[0].iov_len)
+		iov = snd_buf->tail;
+	else
+		iov = snd_buf->head;
+	p = iov->iov_base + iov->iov_len;
+	pad = 3 - ((snd_buf->len - offset - 1) & 3);
+	memset(p, 0, pad);
+	iov->iov_len += pad;
+	snd_buf->len += pad;
+
+	return 0;
+}
+
+static int
+gss_wrap_req(struct rpc_task *task,
+	     kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
+{
+	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
+	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
+			gc_base);
+	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
+	int             status = -EIO;
+
+	dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
+	if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
+		/* The spec seems a little ambiguous here, but I think that not
+		 * wrapping context destruction requests makes the most sense.
+		 */
+		gss_wrap_req_encode(encode, rqstp, p, obj);
+		status = 0;
+		goto out;
+	}
+	switch (gss_cred->gc_service) {
+	case RPC_GSS_SVC_NONE:
+		gss_wrap_req_encode(encode, rqstp, p, obj);
+		status = 0;
+		break;
+	case RPC_GSS_SVC_INTEGRITY:
+		status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
+		break;
+	case RPC_GSS_SVC_PRIVACY:
+		status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
+		break;
+	}
+out:
+	gss_put_ctx(ctx);
+	dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
+	return status;
+}
+
+static inline int
+gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
+		struct rpc_rqst *rqstp, __be32 **p)
+{
+	struct xdr_buf	*rcv_buf = &rqstp->rq_rcv_buf;
+	struct xdr_buf integ_buf;
+	struct xdr_netobj mic;
+	u32 data_offset, mic_offset;
+	u32 integ_len;
+	u32 maj_stat;
+	int status = -EIO;
+
+	integ_len = ntohl(*(*p)++);
+	if (integ_len & 3)
+		return status;
+	data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
+	mic_offset = integ_len + data_offset;
+	if (mic_offset > rcv_buf->len)
+		return status;
+	if (ntohl(*(*p)++) != rqstp->rq_seqno)
+		return status;
+
+	if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
+				mic_offset - data_offset))
+		return status;
+
+	if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
+		return status;
+
+	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
+	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
+		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+	if (maj_stat != GSS_S_COMPLETE)
+		return status;
+	return 0;
+}
+
+static inline int
+gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
+		struct rpc_rqst *rqstp, __be32 **p)
+{
+	struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
+	u32 offset;
+	u32 opaque_len;
+	u32 maj_stat;
+	int status = -EIO;
+
+	opaque_len = ntohl(*(*p)++);
+	offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
+	if (offset + opaque_len > rcv_buf->len)
+		return status;
+	/* remove padding: */
+	rcv_buf->len = offset + opaque_len;
+
+	maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
+	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
+		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+	if (maj_stat != GSS_S_COMPLETE)
+		return status;
+	if (ntohl(*(*p)++) != rqstp->rq_seqno)
+		return status;
+
+	return 0;
+}
+
+static int
+gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
+		      __be32 *p, void *obj)
+{
+	struct xdr_stream xdr;
+
+	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
+	return decode(rqstp, &xdr, obj);
+}
+
+static int
+gss_unwrap_resp(struct rpc_task *task,
+		kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
+{
+	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
+	struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
+			gc_base);
+	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
+	__be32		*savedp = p;
+	struct kvec	*head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
+	int		savedlen = head->iov_len;
+	int             status = -EIO;
+
+	if (ctx->gc_proc != RPC_GSS_PROC_DATA)
+		goto out_decode;
+	switch (gss_cred->gc_service) {
+	case RPC_GSS_SVC_NONE:
+		break;
+	case RPC_GSS_SVC_INTEGRITY:
+		status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
+		if (status)
+			goto out;
+		break;
+	case RPC_GSS_SVC_PRIVACY:
+		status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
+		if (status)
+			goto out;
+		break;
+	}
+	/* take into account extra slack for integrity and privacy cases: */
+	cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
+						+ (savedlen - head->iov_len);
+out_decode:
+	status = gss_unwrap_req_decode(decode, rqstp, p, obj);
+out:
+	gss_put_ctx(ctx);
+	dprintk("RPC: %5u %s returning %d\n",
+		task->tk_pid, __func__, status);
+	return status;
+}
+
+static const struct rpc_authops authgss_ops = {
+	.owner		= THIS_MODULE,
+	.au_flavor	= RPC_AUTH_GSS,
+	.au_name	= "RPCSEC_GSS",
+	.create		= gss_create,
+	.destroy	= gss_destroy,
+	.lookup_cred	= gss_lookup_cred,
+	.crcreate	= gss_create_cred,
+	.list_pseudoflavors = gss_mech_list_pseudoflavors,
+	.info2flavor	= gss_mech_info2flavor,
+	.flavor2info	= gss_mech_flavor2info,
+};
+
+static const struct rpc_credops gss_credops = {
+	.cr_name		= "AUTH_GSS",
+	.crdestroy		= gss_destroy_cred,
+	.cr_init		= gss_cred_init,
+	.crbind			= rpcauth_generic_bind_cred,
+	.crmatch		= gss_match,
+	.crmarshal		= gss_marshal,
+	.crrefresh		= gss_refresh,
+	.crvalidate		= gss_validate,
+	.crwrap_req		= gss_wrap_req,
+	.crunwrap_resp		= gss_unwrap_resp,
+	.crkey_timeout		= gss_key_timeout,
+	.crstringify_acceptor	= gss_stringify_acceptor,
+};
+
+static const struct rpc_credops gss_nullops = {
+	.cr_name		= "AUTH_GSS",
+	.crdestroy		= gss_destroy_nullcred,
+	.crbind			= rpcauth_generic_bind_cred,
+	.crmatch		= gss_match,
+	.crmarshal		= gss_marshal,
+	.crrefresh		= gss_refresh_null,
+	.crvalidate		= gss_validate,
+	.crwrap_req		= gss_wrap_req,
+	.crunwrap_resp		= gss_unwrap_resp,
+	.crstringify_acceptor	= gss_stringify_acceptor,
+};
+
+static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
+	.upcall		= rpc_pipe_generic_upcall,
+	.downcall	= gss_pipe_downcall,
+	.destroy_msg	= gss_pipe_destroy_msg,
+	.open_pipe	= gss_pipe_open_v0,
+	.release_pipe	= gss_pipe_release,
+};
+
+static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
+	.upcall		= rpc_pipe_generic_upcall,
+	.downcall	= gss_pipe_downcall,
+	.destroy_msg	= gss_pipe_destroy_msg,
+	.open_pipe	= gss_pipe_open_v1,
+	.release_pipe	= gss_pipe_release,
+};
+
+static __net_init int rpcsec_gss_init_net(struct net *net)
+{
+	return gss_svc_init_net(net);
+}
+
+static __net_exit void rpcsec_gss_exit_net(struct net *net)
+{
+	gss_svc_shutdown_net(net);
+}
+
+static struct pernet_operations rpcsec_gss_net_ops = {
+	.init = rpcsec_gss_init_net,
+	.exit = rpcsec_gss_exit_net,
+};
+
+/*
+ * Initialize RPCSEC_GSS module
+ */
+static int __init init_rpcsec_gss(void)
+{
+	int err = 0;
+
+	err = rpcauth_register(&authgss_ops);
+	if (err)
+		goto out;
+	err = gss_svc_init();
+	if (err)
+		goto out_unregister;
+	err = register_pernet_subsys(&rpcsec_gss_net_ops);
+	if (err)
+		goto out_svc_exit;
+	rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
+	return 0;
+out_svc_exit:
+	gss_svc_shutdown();
+out_unregister:
+	rpcauth_unregister(&authgss_ops);
+out:
+	return err;
+}
+
+static void __exit exit_rpcsec_gss(void)
+{
+	unregister_pernet_subsys(&rpcsec_gss_net_ops);
+	gss_svc_shutdown();
+	rpcauth_unregister(&authgss_ops);
+	rcu_barrier(); /* Wait for completion of call_rcu()'s */
+}
+
+MODULE_ALIAS("rpc-auth-6");
+MODULE_LICENSE("GPL");
+module_param_named(expired_cred_retry_delay,
+		   gss_expired_cred_retry_delay,
+		   uint, 0644);
+MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
+		"the RPC engine retries an expired credential");
+
+module_param_named(key_expire_timeo,
+		   gss_key_expire_timeo,
+		   uint, 0644);
+MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
+		"credential keys lifetime where the NFS layer cleans up "
+		"prior to key expiration");
+
+module_init(init_rpcsec_gss)
+module_exit(exit_rpcsec_gss)
diff --git a/net/sunrpc/auth_gss/gss_generic_token.c b/net/sunrpc/auth_gss/gss_generic_token.c
new file mode 100644
index 000000000..254defe44
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_generic_token.c
@@ -0,0 +1,234 @@
+/*
+ *  linux/net/sunrpc/gss_generic_token.c
+ *
+ *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/generic/util_token.c
+ *
+ *  Copyright (c) 2000 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson   <andros@umich.edu>
+ */
+
+/*
+ * Copyright 1993 by OpenVision Technologies, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appears in all copies and
+ * that both that copyright notice and this permission notice appear in
+ * supporting documentation, and that the name of OpenVision not be used
+ * in advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission. OpenVision makes no
+ * representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
+ * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/gss_asn1.h>
+
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY        RPCDBG_AUTH
+#endif
+
+
+/* TWRITE_STR from gssapiP_generic.h */
+#define TWRITE_STR(ptr, str, len) \
+	memcpy((ptr), (char *) (str), (len)); \
+	(ptr) += (len);
+
+/* XXXX this code currently makes the assumption that a mech oid will
+   never be longer than 127 bytes.  This assumption is not inherent in
+   the interfaces, so the code can be fixed if the OSI namespace
+   balloons unexpectedly. */
+
+/* Each token looks like this:
+
+0x60				tag for APPLICATION 0, SEQUENCE
+					(constructed, definite-length)
+	<length>		possible multiple bytes, need to parse/generate
+	0x06			tag for OBJECT IDENTIFIER
+		<moid_length>	compile-time constant string (assume 1 byte)
+		<moid_bytes>	compile-time constant string
+	<inner_bytes>		the ANY containing the application token
+					bytes 0,1 are the token type
+					bytes 2,n are the token data
+
+For the purposes of this abstraction, the token "header" consists of
+the sequence tag and length octets, the mech OID DER encoding, and the
+first two inner bytes, which indicate the token type.  The token
+"body" consists of everything else.
+
+*/
+
+static int
+der_length_size( int length)
+{
+	if (length < (1<<7))
+		return 1;
+	else if (length < (1<<8))
+		return 2;
+#if (SIZEOF_INT == 2)
+	else
+		return 3;
+#else
+	else if (length < (1<<16))
+		return 3;
+	else if (length < (1<<24))
+		return 4;
+	else
+		return 5;
+#endif
+}
+
+static void
+der_write_length(unsigned char **buf, int length)
+{
+	if (length < (1<<7)) {
+		*(*buf)++ = (unsigned char) length;
+	} else {
+		*(*buf)++ = (unsigned char) (der_length_size(length)+127);
+#if (SIZEOF_INT > 2)
+		if (length >= (1<<24))
+			*(*buf)++ = (unsigned char) (length>>24);
+		if (length >= (1<<16))
+			*(*buf)++ = (unsigned char) ((length>>16)&0xff);
+#endif
+		if (length >= (1<<8))
+			*(*buf)++ = (unsigned char) ((length>>8)&0xff);
+		*(*buf)++ = (unsigned char) (length&0xff);
+	}
+}
+
+/* returns decoded length, or < 0 on failure.  Advances buf and
+   decrements bufsize */
+
+static int
+der_read_length(unsigned char **buf, int *bufsize)
+{
+	unsigned char sf;
+	int ret;
+
+	if (*bufsize < 1)
+		return -1;
+	sf = *(*buf)++;
+	(*bufsize)--;
+	if (sf & 0x80) {
+		if ((sf &= 0x7f) > ((*bufsize)-1))
+			return -1;
+		if (sf > SIZEOF_INT)
+			return -1;
+		ret = 0;
+		for (; sf; sf--) {
+			ret = (ret<<8) + (*(*buf)++);
+			(*bufsize)--;
+		}
+	} else {
+		ret = sf;
+	}
+
+	return ret;
+}
+
+/* returns the length of a token, given the mech oid and the body size */
+
+int
+g_token_size(struct xdr_netobj *mech, unsigned int body_size)
+{
+	/* set body_size to sequence contents size */
+	body_size += 2 + (int) mech->len;         /* NEED overflow check */
+	return 1 + der_length_size(body_size) + body_size;
+}
+
+EXPORT_SYMBOL_GPL(g_token_size);
+
+/* fills in a buffer with the token header.  The buffer is assumed to
+   be the right size.  buf is advanced past the token header */
+
+void
+g_make_token_header(struct xdr_netobj *mech, int body_size, unsigned char **buf)
+{
+	*(*buf)++ = 0x60;
+	der_write_length(buf, 2 + mech->len + body_size);
+	*(*buf)++ = 0x06;
+	*(*buf)++ = (unsigned char) mech->len;
+	TWRITE_STR(*buf, mech->data, ((int) mech->len));
+}
+
+EXPORT_SYMBOL_GPL(g_make_token_header);
+
+/*
+ * Given a buffer containing a token, reads and verifies the token,
+ * leaving buf advanced past the token header, and setting body_size
+ * to the number of remaining bytes.  Returns 0 on success,
+ * G_BAD_TOK_HEADER for a variety of errors, and G_WRONG_MECH if the
+ * mechanism in the token does not match the mech argument.  buf and
+ * *body_size are left unmodified on error.
+ */
+u32
+g_verify_token_header(struct xdr_netobj *mech, int *body_size,
+		      unsigned char **buf_in, int toksize)
+{
+	unsigned char *buf = *buf_in;
+	int seqsize;
+	struct xdr_netobj toid;
+	int ret = 0;
+
+	if ((toksize-=1) < 0)
+		return G_BAD_TOK_HEADER;
+	if (*buf++ != 0x60)
+		return G_BAD_TOK_HEADER;
+
+	if ((seqsize = der_read_length(&buf, &toksize)) < 0)
+		return G_BAD_TOK_HEADER;
+
+	if (seqsize != toksize)
+		return G_BAD_TOK_HEADER;
+
+	if ((toksize-=1) < 0)
+		return G_BAD_TOK_HEADER;
+	if (*buf++ != 0x06)
+		return G_BAD_TOK_HEADER;
+
+	if ((toksize-=1) < 0)
+		return G_BAD_TOK_HEADER;
+	toid.len = *buf++;
+
+	if ((toksize-=toid.len) < 0)
+		return G_BAD_TOK_HEADER;
+	toid.data = buf;
+	buf+=toid.len;
+
+	if (! g_OID_equal(&toid, mech))
+		ret = G_WRONG_MECH;
+
+   /* G_WRONG_MECH is not returned immediately because it's more important
+      to return G_BAD_TOK_HEADER if the token header is in fact bad */
+
+	if ((toksize-=2) < 0)
+		return G_BAD_TOK_HEADER;
+
+	if (ret)
+		return ret;
+
+	if (!ret) {
+		*buf_in = buf;
+		*body_size = toksize;
+	}
+
+	return ret;
+}
+
+EXPORT_SYMBOL_GPL(g_verify_token_header);
+
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
new file mode 100644
index 000000000..b5408e8a3
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -0,0 +1,988 @@
+/*
+ *  linux/net/sunrpc/gss_krb5_crypto.c
+ *
+ *  Copyright (c) 2000-2008 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson   <andros@umich.edu>
+ *  Bruce Fields   <bfields@umich.edu>
+ */
+
+/*
+ * Copyright (C) 1998 by the FundsXpress, INC.
+ *
+ * All rights reserved.
+ *
+ * Export of this software from the United States of America may require
+ * a specific license from the United States Government.  It is the
+ * responsibility of any person or organization contemplating export to
+ * obtain such a license before exporting.
+ *
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of FundsXpress. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  FundsXpress makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/crypto.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/random.h>
+#include <linux/sunrpc/gss_krb5.h>
+#include <linux/sunrpc/xdr.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY        RPCDBG_AUTH
+#endif
+
+u32
+krb5_encrypt(
+	struct crypto_blkcipher *tfm,
+	void * iv,
+	void * in,
+	void * out,
+	int length)
+{
+	u32 ret = -EINVAL;
+	struct scatterlist sg[1];
+	u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
+	struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };
+
+	if (length % crypto_blkcipher_blocksize(tfm) != 0)
+		goto out;
+
+	if (crypto_blkcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
+		dprintk("RPC:       gss_k5encrypt: tfm iv size too large %d\n",
+			crypto_blkcipher_ivsize(tfm));
+		goto out;
+	}
+
+	if (iv)
+		memcpy(local_iv, iv, crypto_blkcipher_ivsize(tfm));
+
+	memcpy(out, in, length);
+	sg_init_one(sg, out, length);
+
+	ret = crypto_blkcipher_encrypt_iv(&desc, sg, sg, length);
+out:
+	dprintk("RPC:       krb5_encrypt returns %d\n", ret);
+	return ret;
+}
+
+u32
+krb5_decrypt(
+     struct crypto_blkcipher *tfm,
+     void * iv,
+     void * in,
+     void * out,
+     int length)
+{
+	u32 ret = -EINVAL;
+	struct scatterlist sg[1];
+	u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
+	struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };
+
+	if (length % crypto_blkcipher_blocksize(tfm) != 0)
+		goto out;
+
+	if (crypto_blkcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
+		dprintk("RPC:       gss_k5decrypt: tfm iv size too large %d\n",
+			crypto_blkcipher_ivsize(tfm));
+		goto out;
+	}
+	if (iv)
+		memcpy(local_iv,iv, crypto_blkcipher_ivsize(tfm));
+
+	memcpy(out, in, length);
+	sg_init_one(sg, out, length);
+
+	ret = crypto_blkcipher_decrypt_iv(&desc, sg, sg, length);
+out:
+	dprintk("RPC:       gss_k5decrypt returns %d\n",ret);
+	return ret;
+}
+
+static int
+checksummer(struct scatterlist *sg, void *data)
+{
+	struct hash_desc *desc = data;
+
+	return crypto_hash_update(desc, sg, sg->length);
+}
+
+static int
+arcfour_hmac_md5_usage_to_salt(unsigned int usage, u8 salt[4])
+{
+	unsigned int ms_usage;
+
+	switch (usage) {
+	case KG_USAGE_SIGN:
+		ms_usage = 15;
+		break;
+	case KG_USAGE_SEAL:
+		ms_usage = 13;
+		break;
+	default:
+		return -EINVAL;
+	}
+	salt[0] = (ms_usage >> 0) & 0xff;
+	salt[1] = (ms_usage >> 8) & 0xff;
+	salt[2] = (ms_usage >> 16) & 0xff;
+	salt[3] = (ms_usage >> 24) & 0xff;
+
+	return 0;
+}
+
+static u32
+make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen,
+		       struct xdr_buf *body, int body_offset, u8 *cksumkey,
+		       unsigned int usage, struct xdr_netobj *cksumout)
+{
+	struct hash_desc                desc;
+	struct scatterlist              sg[1];
+	int err;
+	u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	u8 rc4salt[4];
+	struct crypto_hash *md5;
+	struct crypto_hash *hmac_md5;
+
+	if (cksumkey == NULL)
+		return GSS_S_FAILURE;
+
+	if (cksumout->len < kctx->gk5e->cksumlength) {
+		dprintk("%s: checksum buffer length, %u, too small for %s\n",
+			__func__, cksumout->len, kctx->gk5e->name);
+		return GSS_S_FAILURE;
+	}
+
+	if (arcfour_hmac_md5_usage_to_salt(usage, rc4salt)) {
+		dprintk("%s: invalid usage value %u\n", __func__, usage);
+		return GSS_S_FAILURE;
+	}
+
+	md5 = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(md5))
+		return GSS_S_FAILURE;
+
+	hmac_md5 = crypto_alloc_hash(kctx->gk5e->cksum_name, 0,
+				     CRYPTO_ALG_ASYNC);
+	if (IS_ERR(hmac_md5)) {
+		crypto_free_hash(md5);
+		return GSS_S_FAILURE;
+	}
+
+	desc.tfm = md5;
+	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	err = crypto_hash_init(&desc);
+	if (err)
+		goto out;
+	sg_init_one(sg, rc4salt, 4);
+	err = crypto_hash_update(&desc, sg, 4);
+	if (err)
+		goto out;
+
+	sg_init_one(sg, header, hdrlen);
+	err = crypto_hash_update(&desc, sg, hdrlen);
+	if (err)
+		goto out;
+	err = xdr_process_buf(body, body_offset, body->len - body_offset,
+			      checksummer, &desc);
+	if (err)
+		goto out;
+	err = crypto_hash_final(&desc, checksumdata);
+	if (err)
+		goto out;
+
+	desc.tfm = hmac_md5;
+	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	err = crypto_hash_init(&desc);
+	if (err)
+		goto out;
+	err = crypto_hash_setkey(hmac_md5, cksumkey, kctx->gk5e->keylength);
+	if (err)
+		goto out;
+
+	sg_init_one(sg, checksumdata, crypto_hash_digestsize(md5));
+	err = crypto_hash_digest(&desc, sg, crypto_hash_digestsize(md5),
+				 checksumdata);
+	if (err)
+		goto out;
+
+	memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
+	cksumout->len = kctx->gk5e->cksumlength;
+out:
+	crypto_free_hash(md5);
+	crypto_free_hash(hmac_md5);
+	return err ? GSS_S_FAILURE : 0;
+}
+
+/*
+ * checksum the plaintext data and hdrlen bytes of the token header
+ * The checksum is performed over the first 8 bytes of the
+ * gss token header and then over the data body
+ */
+u32
+make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen,
+	      struct xdr_buf *body, int body_offset, u8 *cksumkey,
+	      unsigned int usage, struct xdr_netobj *cksumout)
+{
+	struct hash_desc                desc;
+	struct scatterlist              sg[1];
+	int err;
+	u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	unsigned int checksumlen;
+
+	if (kctx->gk5e->ctype == CKSUMTYPE_HMAC_MD5_ARCFOUR)
+		return make_checksum_hmac_md5(kctx, header, hdrlen,
+					      body, body_offset,
+					      cksumkey, usage, cksumout);
+
+	if (cksumout->len < kctx->gk5e->cksumlength) {
+		dprintk("%s: checksum buffer length, %u, too small for %s\n",
+			__func__, cksumout->len, kctx->gk5e->name);
+		return GSS_S_FAILURE;
+	}
+
+	desc.tfm = crypto_alloc_hash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(desc.tfm))
+		return GSS_S_FAILURE;
+	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	checksumlen = crypto_hash_digestsize(desc.tfm);
+
+	if (cksumkey != NULL) {
+		err = crypto_hash_setkey(desc.tfm, cksumkey,
+					 kctx->gk5e->keylength);
+		if (err)
+			goto out;
+	}
+
+	err = crypto_hash_init(&desc);
+	if (err)
+		goto out;
+	sg_init_one(sg, header, hdrlen);
+	err = crypto_hash_update(&desc, sg, hdrlen);
+	if (err)
+		goto out;
+	err = xdr_process_buf(body, body_offset, body->len - body_offset,
+			      checksummer, &desc);
+	if (err)
+		goto out;
+	err = crypto_hash_final(&desc, checksumdata);
+	if (err)
+		goto out;
+
+	switch (kctx->gk5e->ctype) {
+	case CKSUMTYPE_RSA_MD5:
+		err = kctx->gk5e->encrypt(kctx->seq, NULL, checksumdata,
+					  checksumdata, checksumlen);
+		if (err)
+			goto out;
+		memcpy(cksumout->data,
+		       checksumdata + checksumlen - kctx->gk5e->cksumlength,
+		       kctx->gk5e->cksumlength);
+		break;
+	case CKSUMTYPE_HMAC_SHA1_DES3:
+		memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
+		break;
+	default:
+		BUG();
+		break;
+	}
+	cksumout->len = kctx->gk5e->cksumlength;
+out:
+	crypto_free_hash(desc.tfm);
+	return err ? GSS_S_FAILURE : 0;
+}
+
+/*
+ * checksum the plaintext data and hdrlen bytes of the token header
+ * Per rfc4121, sec. 4.2.4, the checksum is performed over the data
+ * body then over the first 16 octets of the MIC token
+ * Inclusion of the header data in the calculation of the
+ * checksum is optional.
+ */
+u32
+make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen,
+		 struct xdr_buf *body, int body_offset, u8 *cksumkey,
+		 unsigned int usage, struct xdr_netobj *cksumout)
+{
+	struct hash_desc desc;
+	struct scatterlist sg[1];
+	int err;
+	u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	unsigned int checksumlen;
+
+	if (kctx->gk5e->keyed_cksum == 0) {
+		dprintk("%s: expected keyed hash for %s\n",
+			__func__, kctx->gk5e->name);
+		return GSS_S_FAILURE;
+	}
+	if (cksumkey == NULL) {
+		dprintk("%s: no key supplied for %s\n",
+			__func__, kctx->gk5e->name);
+		return GSS_S_FAILURE;
+	}
+
+	desc.tfm = crypto_alloc_hash(kctx->gk5e->cksum_name, 0,
+							CRYPTO_ALG_ASYNC);
+	if (IS_ERR(desc.tfm))
+		return GSS_S_FAILURE;
+	checksumlen = crypto_hash_digestsize(desc.tfm);
+	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	err = crypto_hash_setkey(desc.tfm, cksumkey, kctx->gk5e->keylength);
+	if (err)
+		goto out;
+
+	err = crypto_hash_init(&desc);
+	if (err)
+		goto out;
+	err = xdr_process_buf(body, body_offset, body->len - body_offset,
+			      checksummer, &desc);
+	if (err)
+		goto out;
+	if (header != NULL) {
+		sg_init_one(sg, header, hdrlen);
+		err = crypto_hash_update(&desc, sg, hdrlen);
+		if (err)
+			goto out;
+	}
+	err = crypto_hash_final(&desc, checksumdata);
+	if (err)
+		goto out;
+
+	cksumout->len = kctx->gk5e->cksumlength;
+
+	switch (kctx->gk5e->ctype) {
+	case CKSUMTYPE_HMAC_SHA1_96_AES128:
+	case CKSUMTYPE_HMAC_SHA1_96_AES256:
+		/* note that this truncates the hash */
+		memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
+		break;
+	default:
+		BUG();
+		break;
+	}
+out:
+	crypto_free_hash(desc.tfm);
+	return err ? GSS_S_FAILURE : 0;
+}
+
+struct encryptor_desc {
+	u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
+	struct blkcipher_desc desc;
+	int pos;
+	struct xdr_buf *outbuf;
+	struct page **pages;
+	struct scatterlist infrags[4];
+	struct scatterlist outfrags[4];
+	int fragno;
+	int fraglen;
+};
+
+static int
+encryptor(struct scatterlist *sg, void *data)
+{
+	struct encryptor_desc *desc = data;
+	struct xdr_buf *outbuf = desc->outbuf;
+	struct page *in_page;
+	int thislen = desc->fraglen + sg->length;
+	int fraglen, ret;
+	int page_pos;
+
+	/* Worst case is 4 fragments: head, end of page 1, start
+	 * of page 2, tail.  Anything more is a bug. */
+	BUG_ON(desc->fragno > 3);
+
+	page_pos = desc->pos - outbuf->head[0].iov_len;
+	if (page_pos >= 0 && page_pos < outbuf->page_len) {
+		/* pages are not in place: */
+		int i = (page_pos + outbuf->page_base) >> PAGE_CACHE_SHIFT;
+		in_page = desc->pages[i];
+	} else {
+		in_page = sg_page(sg);
+	}
+	sg_set_page(&desc->infrags[desc->fragno], in_page, sg->length,
+		    sg->offset);
+	sg_set_page(&desc->outfrags[desc->fragno], sg_page(sg), sg->length,
+		    sg->offset);
+	desc->fragno++;
+	desc->fraglen += sg->length;
+	desc->pos += sg->length;
+
+	fraglen = thislen & (crypto_blkcipher_blocksize(desc->desc.tfm) - 1);
+	thislen -= fraglen;
+
+	if (thislen == 0)
+		return 0;
+
+	sg_mark_end(&desc->infrags[desc->fragno - 1]);
+	sg_mark_end(&desc->outfrags[desc->fragno - 1]);
+
+	ret = crypto_blkcipher_encrypt_iv(&desc->desc, desc->outfrags,
+					  desc->infrags, thislen);
+	if (ret)
+		return ret;
+
+	sg_init_table(desc->infrags, 4);
+	sg_init_table(desc->outfrags, 4);
+
+	if (fraglen) {
+		sg_set_page(&desc->outfrags[0], sg_page(sg), fraglen,
+				sg->offset + sg->length - fraglen);
+		desc->infrags[0] = desc->outfrags[0];
+		sg_assign_page(&desc->infrags[0], in_page);
+		desc->fragno = 1;
+		desc->fraglen = fraglen;
+	} else {
+		desc->fragno = 0;
+		desc->fraglen = 0;
+	}
+	return 0;
+}
+
+int
+gss_encrypt_xdr_buf(struct crypto_blkcipher *tfm, struct xdr_buf *buf,
+		    int offset, struct page **pages)
+{
+	int ret;
+	struct encryptor_desc desc;
+
+	BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0);
+
+	memset(desc.iv, 0, sizeof(desc.iv));
+	desc.desc.tfm = tfm;
+	desc.desc.info = desc.iv;
+	desc.desc.flags = 0;
+	desc.pos = offset;
+	desc.outbuf = buf;
+	desc.pages = pages;
+	desc.fragno = 0;
+	desc.fraglen = 0;
+
+	sg_init_table(desc.infrags, 4);
+	sg_init_table(desc.outfrags, 4);
+
+	ret = xdr_process_buf(buf, offset, buf->len - offset, encryptor, &desc);
+	return ret;
+}
+
+struct decryptor_desc {
+	u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
+	struct blkcipher_desc desc;
+	struct scatterlist frags[4];
+	int fragno;
+	int fraglen;
+};
+
+static int
+decryptor(struct scatterlist *sg, void *data)
+{
+	struct decryptor_desc *desc = data;
+	int thislen = desc->fraglen + sg->length;
+	int fraglen, ret;
+
+	/* Worst case is 4 fragments: head, end of page 1, start
+	 * of page 2, tail.  Anything more is a bug. */
+	BUG_ON(desc->fragno > 3);
+	sg_set_page(&desc->frags[desc->fragno], sg_page(sg), sg->length,
+		    sg->offset);
+	desc->fragno++;
+	desc->fraglen += sg->length;
+
+	fraglen = thislen & (crypto_blkcipher_blocksize(desc->desc.tfm) - 1);
+	thislen -= fraglen;
+
+	if (thislen == 0)
+		return 0;
+
+	sg_mark_end(&desc->frags[desc->fragno - 1]);
+
+	ret = crypto_blkcipher_decrypt_iv(&desc->desc, desc->frags,
+					  desc->frags, thislen);
+	if (ret)
+		return ret;
+
+	sg_init_table(desc->frags, 4);
+
+	if (fraglen) {
+		sg_set_page(&desc->frags[0], sg_page(sg), fraglen,
+				sg->offset + sg->length - fraglen);
+		desc->fragno = 1;
+		desc->fraglen = fraglen;
+	} else {
+		desc->fragno = 0;
+		desc->fraglen = 0;
+	}
+	return 0;
+}
+
+int
+gss_decrypt_xdr_buf(struct crypto_blkcipher *tfm, struct xdr_buf *buf,
+		    int offset)
+{
+	struct decryptor_desc desc;
+
+	/* XXXJBF: */
+	BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0);
+
+	memset(desc.iv, 0, sizeof(desc.iv));
+	desc.desc.tfm = tfm;
+	desc.desc.info = desc.iv;
+	desc.desc.flags = 0;
+	desc.fragno = 0;
+	desc.fraglen = 0;
+
+	sg_init_table(desc.frags, 4);
+
+	return xdr_process_buf(buf, offset, buf->len - offset, decryptor, &desc);
+}
+
+/*
+ * This function makes the assumption that it was ultimately called
+ * from gss_wrap().
+ *
+ * The client auth_gss code moves any existing tail data into a
+ * separate page before calling gss_wrap.
+ * The server svcauth_gss code ensures that both the head and the
+ * tail have slack space of RPC_MAX_AUTH_SIZE before calling gss_wrap.
+ *
+ * Even with that guarantee, this function may be called more than
+ * once in the processing of gss_wrap().  The best we can do is
+ * verify at compile-time (see GSS_KRB5_SLACK_CHECK) that the
+ * largest expected shift will fit within RPC_MAX_AUTH_SIZE.
+ * At run-time we can verify that a single invocation of this
+ * function doesn't attempt to use more the RPC_MAX_AUTH_SIZE.
+ */
+
+int
+xdr_extend_head(struct xdr_buf *buf, unsigned int base, unsigned int shiftlen)
+{
+	u8 *p;
+
+	if (shiftlen == 0)
+		return 0;
+
+	BUILD_BUG_ON(GSS_KRB5_MAX_SLACK_NEEDED > RPC_MAX_AUTH_SIZE);
+	BUG_ON(shiftlen > RPC_MAX_AUTH_SIZE);
+
+	p = buf->head[0].iov_base + base;
+
+	memmove(p + shiftlen, p, buf->head[0].iov_len - base);
+
+	buf->head[0].iov_len += shiftlen;
+	buf->len += shiftlen;
+
+	return 0;
+}
+
+static u32
+gss_krb5_cts_crypt(struct crypto_blkcipher *cipher, struct xdr_buf *buf,
+		   u32 offset, u8 *iv, struct page **pages, int encrypt)
+{
+	u32 ret;
+	struct scatterlist sg[1];
+	struct blkcipher_desc desc = { .tfm = cipher, .info = iv };
+	u8 data[GSS_KRB5_MAX_BLOCKSIZE * 2];
+	struct page **save_pages;
+	u32 len = buf->len - offset;
+
+	if (len > ARRAY_SIZE(data)) {
+		WARN_ON(0);
+		return -ENOMEM;
+	}
+
+	/*
+	 * For encryption, we want to read from the cleartext
+	 * page cache pages, and write the encrypted data to
+	 * the supplied xdr_buf pages.
+	 */
+	save_pages = buf->pages;
+	if (encrypt)
+		buf->pages = pages;
+
+	ret = read_bytes_from_xdr_buf(buf, offset, data, len);
+	buf->pages = save_pages;
+	if (ret)
+		goto out;
+
+	sg_init_one(sg, data, len);
+
+	if (encrypt)
+		ret = crypto_blkcipher_encrypt_iv(&desc, sg, sg, len);
+	else
+		ret = crypto_blkcipher_decrypt_iv(&desc, sg, sg, len);
+
+	if (ret)
+		goto out;
+
+	ret = write_bytes_to_xdr_buf(buf, offset, data, len);
+
+out:
+	return ret;
+}
+
+u32
+gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
+		     struct xdr_buf *buf, struct page **pages)
+{
+	u32 err;
+	struct xdr_netobj hmac;
+	u8 *cksumkey;
+	u8 *ecptr;
+	struct crypto_blkcipher *cipher, *aux_cipher;
+	int blocksize;
+	struct page **save_pages;
+	int nblocks, nbytes;
+	struct encryptor_desc desc;
+	u32 cbcbytes;
+	unsigned int usage;
+
+	if (kctx->initiate) {
+		cipher = kctx->initiator_enc;
+		aux_cipher = kctx->initiator_enc_aux;
+		cksumkey = kctx->initiator_integ;
+		usage = KG_USAGE_INITIATOR_SEAL;
+	} else {
+		cipher = kctx->acceptor_enc;
+		aux_cipher = kctx->acceptor_enc_aux;
+		cksumkey = kctx->acceptor_integ;
+		usage = KG_USAGE_ACCEPTOR_SEAL;
+	}
+	blocksize = crypto_blkcipher_blocksize(cipher);
+
+	/* hide the gss token header and insert the confounder */
+	offset += GSS_KRB5_TOK_HDR_LEN;
+	if (xdr_extend_head(buf, offset, kctx->gk5e->conflen))
+		return GSS_S_FAILURE;
+	gss_krb5_make_confounder(buf->head[0].iov_base + offset, kctx->gk5e->conflen);
+	offset -= GSS_KRB5_TOK_HDR_LEN;
+
+	if (buf->tail[0].iov_base != NULL) {
+		ecptr = buf->tail[0].iov_base + buf->tail[0].iov_len;
+	} else {
+		buf->tail[0].iov_base = buf->head[0].iov_base
+							+ buf->head[0].iov_len;
+		buf->tail[0].iov_len = 0;
+		ecptr = buf->tail[0].iov_base;
+	}
+
+	/* copy plaintext gss token header after filler (if any) */
+	memcpy(ecptr, buf->head[0].iov_base + offset, GSS_KRB5_TOK_HDR_LEN);
+	buf->tail[0].iov_len += GSS_KRB5_TOK_HDR_LEN;
+	buf->len += GSS_KRB5_TOK_HDR_LEN;
+
+	/* Do the HMAC */
+	hmac.len = GSS_KRB5_MAX_CKSUM_LEN;
+	hmac.data = buf->tail[0].iov_base + buf->tail[0].iov_len;
+
+	/*
+	 * When we are called, pages points to the real page cache
+	 * data -- which we can't go and encrypt!  buf->pages points
+	 * to scratch pages which we are going to send off to the
+	 * client/server.  Swap in the plaintext pages to calculate
+	 * the hmac.
+	 */
+	save_pages = buf->pages;
+	buf->pages = pages;
+
+	err = make_checksum_v2(kctx, NULL, 0, buf,
+			       offset + GSS_KRB5_TOK_HDR_LEN,
+			       cksumkey, usage, &hmac);
+	buf->pages = save_pages;
+	if (err)
+		return GSS_S_FAILURE;
+
+	nbytes = buf->len - offset - GSS_KRB5_TOK_HDR_LEN;
+	nblocks = (nbytes + blocksize - 1) / blocksize;
+	cbcbytes = 0;
+	if (nblocks > 2)
+		cbcbytes = (nblocks - 2) * blocksize;
+
+	memset(desc.iv, 0, sizeof(desc.iv));
+
+	if (cbcbytes) {
+		desc.pos = offset + GSS_KRB5_TOK_HDR_LEN;
+		desc.fragno = 0;
+		desc.fraglen = 0;
+		desc.pages = pages;
+		desc.outbuf = buf;
+		desc.desc.info = desc.iv;
+		desc.desc.flags = 0;
+		desc.desc.tfm = aux_cipher;
+
+		sg_init_table(desc.infrags, 4);
+		sg_init_table(desc.outfrags, 4);
+
+		err = xdr_process_buf(buf, offset + GSS_KRB5_TOK_HDR_LEN,
+				      cbcbytes, encryptor, &desc);
+		if (err)
+			goto out_err;
+	}
+
+	/* Make sure IV carries forward from any CBC results. */
+	err = gss_krb5_cts_crypt(cipher, buf,
+				 offset + GSS_KRB5_TOK_HDR_LEN + cbcbytes,
+				 desc.iv, pages, 1);
+	if (err) {
+		err = GSS_S_FAILURE;
+		goto out_err;
+	}
+
+	/* Now update buf to account for HMAC */
+	buf->tail[0].iov_len += kctx->gk5e->cksumlength;
+	buf->len += kctx->gk5e->cksumlength;
+
+out_err:
+	if (err)
+		err = GSS_S_FAILURE;
+	return err;
+}
+
+u32
+gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
+		     u32 *headskip, u32 *tailskip)
+{
+	struct xdr_buf subbuf;
+	u32 ret = 0;
+	u8 *cksum_key;
+	struct crypto_blkcipher *cipher, *aux_cipher;
+	struct xdr_netobj our_hmac_obj;
+	u8 our_hmac[GSS_KRB5_MAX_CKSUM_LEN];
+	u8 pkt_hmac[GSS_KRB5_MAX_CKSUM_LEN];
+	int nblocks, blocksize, cbcbytes;
+	struct decryptor_desc desc;
+	unsigned int usage;
+
+	if (kctx->initiate) {
+		cipher = kctx->acceptor_enc;
+		aux_cipher = kctx->acceptor_enc_aux;
+		cksum_key = kctx->acceptor_integ;
+		usage = KG_USAGE_ACCEPTOR_SEAL;
+	} else {
+		cipher = kctx->initiator_enc;
+		aux_cipher = kctx->initiator_enc_aux;
+		cksum_key = kctx->initiator_integ;
+		usage = KG_USAGE_INITIATOR_SEAL;
+	}
+	blocksize = crypto_blkcipher_blocksize(cipher);
+
+
+	/* create a segment skipping the header and leaving out the checksum */
+	xdr_buf_subsegment(buf, &subbuf, offset + GSS_KRB5_TOK_HDR_LEN,
+				    (buf->len - offset - GSS_KRB5_TOK_HDR_LEN -
+				     kctx->gk5e->cksumlength));
+
+	nblocks = (subbuf.len + blocksize - 1) / blocksize;
+
+	cbcbytes = 0;
+	if (nblocks > 2)
+		cbcbytes = (nblocks - 2) * blocksize;
+
+	memset(desc.iv, 0, sizeof(desc.iv));
+
+	if (cbcbytes) {
+		desc.fragno = 0;
+		desc.fraglen = 0;
+		desc.desc.info = desc.iv;
+		desc.desc.flags = 0;
+		desc.desc.tfm = aux_cipher;
+
+		sg_init_table(desc.frags, 4);
+
+		ret = xdr_process_buf(&subbuf, 0, cbcbytes, decryptor, &desc);
+		if (ret)
+			goto out_err;
+	}
+
+	/* Make sure IV carries forward from any CBC results. */
+	ret = gss_krb5_cts_crypt(cipher, &subbuf, cbcbytes, desc.iv, NULL, 0);
+	if (ret)
+		goto out_err;
+
+
+	/* Calculate our hmac over the plaintext data */
+	our_hmac_obj.len = sizeof(our_hmac);
+	our_hmac_obj.data = our_hmac;
+
+	ret = make_checksum_v2(kctx, NULL, 0, &subbuf, 0,
+			       cksum_key, usage, &our_hmac_obj);
+	if (ret)
+		goto out_err;
+
+	/* Get the packet's hmac value */
+	ret = read_bytes_from_xdr_buf(buf, buf->len - kctx->gk5e->cksumlength,
+				      pkt_hmac, kctx->gk5e->cksumlength);
+	if (ret)
+		goto out_err;
+
+	if (memcmp(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
+		ret = GSS_S_BAD_SIG;
+		goto out_err;
+	}
+	*headskip = kctx->gk5e->conflen;
+	*tailskip = kctx->gk5e->cksumlength;
+out_err:
+	if (ret && ret != GSS_S_BAD_SIG)
+		ret = GSS_S_FAILURE;
+	return ret;
+}
+
+/*
+ * Compute Kseq given the initial session key and the checksum.
+ * Set the key of the given cipher.
+ */
+int
+krb5_rc4_setup_seq_key(struct krb5_ctx *kctx, struct crypto_blkcipher *cipher,
+		       unsigned char *cksum)
+{
+	struct crypto_hash *hmac;
+	struct hash_desc desc;
+	struct scatterlist sg[1];
+	u8 Kseq[GSS_KRB5_MAX_KEYLEN];
+	u32 zeroconstant = 0;
+	int err;
+
+	dprintk("%s: entered\n", __func__);
+
+	hmac = crypto_alloc_hash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(hmac)) {
+		dprintk("%s: error %ld, allocating hash '%s'\n",
+			__func__, PTR_ERR(hmac), kctx->gk5e->cksum_name);
+		return PTR_ERR(hmac);
+	}
+
+	desc.tfm = hmac;
+	desc.flags = 0;
+
+	err = crypto_hash_init(&desc);
+	if (err)
+		goto out_err;
+
+	/* Compute intermediate Kseq from session key */
+	err = crypto_hash_setkey(hmac, kctx->Ksess, kctx->gk5e->keylength);
+	if (err)
+		goto out_err;
+
+	sg_init_table(sg, 1);
+	sg_set_buf(sg, &zeroconstant, 4);
+
+	err = crypto_hash_digest(&desc, sg, 4, Kseq);
+	if (err)
+		goto out_err;
+
+	/* Compute final Kseq from the checksum and intermediate Kseq */
+	err = crypto_hash_setkey(hmac, Kseq, kctx->gk5e->keylength);
+	if (err)
+		goto out_err;
+
+	sg_set_buf(sg, cksum, 8);
+
+	err = crypto_hash_digest(&desc, sg, 8, Kseq);
+	if (err)
+		goto out_err;
+
+	err = crypto_blkcipher_setkey(cipher, Kseq, kctx->gk5e->keylength);
+	if (err)
+		goto out_err;
+
+	err = 0;
+
+out_err:
+	crypto_free_hash(hmac);
+	dprintk("%s: returning %d\n", __func__, err);
+	return err;
+}
+
+/*
+ * Compute Kcrypt given the initial session key and the plaintext seqnum.
+ * Set the key of cipher kctx->enc.
+ */
+int
+krb5_rc4_setup_enc_key(struct krb5_ctx *kctx, struct crypto_blkcipher *cipher,
+		       s32 seqnum)
+{
+	struct crypto_hash *hmac;
+	struct hash_desc desc;
+	struct scatterlist sg[1];
+	u8 Kcrypt[GSS_KRB5_MAX_KEYLEN];
+	u8 zeroconstant[4] = {0};
+	u8 seqnumarray[4];
+	int err, i;
+
+	dprintk("%s: entered, seqnum %u\n", __func__, seqnum);
+
+	hmac = crypto_alloc_hash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(hmac)) {
+		dprintk("%s: error %ld, allocating hash '%s'\n",
+			__func__, PTR_ERR(hmac), kctx->gk5e->cksum_name);
+		return PTR_ERR(hmac);
+	}
+
+	desc.tfm = hmac;
+	desc.flags = 0;
+
+	err = crypto_hash_init(&desc);
+	if (err)
+		goto out_err;
+
+	/* Compute intermediate Kcrypt from session key */
+	for (i = 0; i < kctx->gk5e->keylength; i++)
+		Kcrypt[i] = kctx->Ksess[i] ^ 0xf0;
+
+	err = crypto_hash_setkey(hmac, Kcrypt, kctx->gk5e->keylength);
+	if (err)
+		goto out_err;
+
+	sg_init_table(sg, 1);
+	sg_set_buf(sg, zeroconstant, 4);
+
+	err = crypto_hash_digest(&desc, sg, 4, Kcrypt);
+	if (err)
+		goto out_err;
+
+	/* Compute final Kcrypt from the seqnum and intermediate Kcrypt */
+	err = crypto_hash_setkey(hmac, Kcrypt, kctx->gk5e->keylength);
+	if (err)
+		goto out_err;
+
+	seqnumarray[0] = (unsigned char) ((seqnum >> 24) & 0xff);
+	seqnumarray[1] = (unsigned char) ((seqnum >> 16) & 0xff);
+	seqnumarray[2] = (unsigned char) ((seqnum >> 8) & 0xff);
+	seqnumarray[3] = (unsigned char) ((seqnum >> 0) & 0xff);
+
+	sg_set_buf(sg, seqnumarray, 4);
+
+	err = crypto_hash_digest(&desc, sg, 4, Kcrypt);
+	if (err)
+		goto out_err;
+
+	err = crypto_blkcipher_setkey(cipher, Kcrypt, kctx->gk5e->keylength);
+	if (err)
+		goto out_err;
+
+	err = 0;
+
+out_err:
+	crypto_free_hash(hmac);
+	dprintk("%s: returning %d\n", __func__, err);
+	return err;
+}
+
diff --git a/net/sunrpc/auth_gss/gss_krb5_keys.c b/net/sunrpc/auth_gss/gss_krb5_keys.c
new file mode 100644
index 000000000..234fa8d0f
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_krb5_keys.c
@@ -0,0 +1,327 @@
+/*
+ * COPYRIGHT (c) 2008
+ * The Regents of the University of Michigan
+ * ALL RIGHTS RESERVED
+ *
+ * Permission is granted to use, copy, create derivative works
+ * and redistribute this software and such derivative works
+ * for any purpose, so long as the name of The University of
+ * Michigan is not used in any advertising or publicity
+ * pertaining to the use of distribution of this software
+ * without specific, written prior authorization.  If the
+ * above copyright notice or any other identification of the
+ * University of Michigan is included in any copy of any
+ * portion of this software, then the disclaimer below must
+ * also be included.
+ *
+ * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
+ * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
+ * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
+ * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
+ * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
+ * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
+ * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
+ * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
+ * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGES.
+ */
+
+/*
+ * Copyright (C) 1998 by the FundsXpress, INC.
+ *
+ * All rights reserved.
+ *
+ * Export of this software from the United States of America may require
+ * a specific license from the United States Government.  It is the
+ * responsibility of any person or organization contemplating export to
+ * obtain such a license before exporting.
+ *
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of FundsXpress. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  FundsXpress makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/crypto.h>
+#include <linux/sunrpc/gss_krb5.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/lcm.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY        RPCDBG_AUTH
+#endif
+
+/*
+ * This is the n-fold function as described in rfc3961, sec 5.1
+ * Taken from MIT Kerberos and modified.
+ */
+
+static void krb5_nfold(u32 inbits, const u8 *in,
+		       u32 outbits, u8 *out)
+{
+	unsigned long ulcm;
+	int byte, i, msbit;
+
+	/* the code below is more readable if I make these bytes
+	   instead of bits */
+
+	inbits >>= 3;
+	outbits >>= 3;
+
+	/* first compute lcm(n,k) */
+	ulcm = lcm(inbits, outbits);
+
+	/* now do the real work */
+
+	memset(out, 0, outbits);
+	byte = 0;
+
+	/* this will end up cycling through k lcm(k,n)/k times, which
+	   is correct */
+	for (i = ulcm-1; i >= 0; i--) {
+		/* compute the msbit in k which gets added into this byte */
+		msbit = (
+			/* first, start with the msbit in the first,
+			 * unrotated byte */
+			 ((inbits << 3) - 1)
+			 /* then, for each byte, shift to the right
+			  * for each repetition */
+			 + (((inbits << 3) + 13) * (i/inbits))
+			 /* last, pick out the correct byte within
+			  * that shifted repetition */
+			 + ((inbits - (i % inbits)) << 3)
+			 ) % (inbits << 3);
+
+		/* pull out the byte value itself */
+		byte += (((in[((inbits - 1) - (msbit >> 3)) % inbits] << 8)|
+				  (in[((inbits) - (msbit >> 3)) % inbits]))
+				 >> ((msbit & 7) + 1)) & 0xff;
+
+		/* do the addition */
+		byte += out[i % outbits];
+		out[i % outbits] = byte & 0xff;
+
+		/* keep around the carry bit, if any */
+		byte >>= 8;
+
+	}
+
+	/* if there's a carry bit left over, add it back in */
+	if (byte) {
+		for (i = outbits - 1; i >= 0; i--) {
+			/* do the addition */
+			byte += out[i];
+			out[i] = byte & 0xff;
+
+			/* keep around the carry bit, if any */
+			byte >>= 8;
+		}
+	}
+}
+
+/*
+ * This is the DK (derive_key) function as described in rfc3961, sec 5.1
+ * Taken from MIT Kerberos and modified.
+ */
+
+u32 krb5_derive_key(const struct gss_krb5_enctype *gk5e,
+		    const struct xdr_netobj *inkey,
+		    struct xdr_netobj *outkey,
+		    const struct xdr_netobj *in_constant,
+		    gfp_t gfp_mask)
+{
+	size_t blocksize, keybytes, keylength, n;
+	unsigned char *inblockdata, *outblockdata, *rawkey;
+	struct xdr_netobj inblock, outblock;
+	struct crypto_blkcipher *cipher;
+	u32 ret = EINVAL;
+
+	blocksize = gk5e->blocksize;
+	keybytes = gk5e->keybytes;
+	keylength = gk5e->keylength;
+
+	if ((inkey->len != keylength) || (outkey->len != keylength))
+		goto err_return;
+
+	cipher = crypto_alloc_blkcipher(gk5e->encrypt_name, 0,
+					CRYPTO_ALG_ASYNC);
+	if (IS_ERR(cipher))
+		goto err_return;
+	if (crypto_blkcipher_setkey(cipher, inkey->data, inkey->len))
+		goto err_return;
+
+	/* allocate and set up buffers */
+
+	ret = ENOMEM;
+	inblockdata = kmalloc(blocksize, gfp_mask);
+	if (inblockdata == NULL)
+		goto err_free_cipher;
+
+	outblockdata = kmalloc(blocksize, gfp_mask);
+	if (outblockdata == NULL)
+		goto err_free_in;
+
+	rawkey = kmalloc(keybytes, gfp_mask);
+	if (rawkey == NULL)
+		goto err_free_out;
+
+	inblock.data = (char *) inblockdata;
+	inblock.len = blocksize;
+
+	outblock.data = (char *) outblockdata;
+	outblock.len = blocksize;
+
+	/* initialize the input block */
+
+	if (in_constant->len == inblock.len) {
+		memcpy(inblock.data, in_constant->data, inblock.len);
+	} else {
+		krb5_nfold(in_constant->len * 8, in_constant->data,
+			   inblock.len * 8, inblock.data);
+	}
+
+	/* loop encrypting the blocks until enough key bytes are generated */
+
+	n = 0;
+	while (n < keybytes) {
+		(*(gk5e->encrypt))(cipher, NULL, inblock.data,
+				   outblock.data, inblock.len);
+
+		if ((keybytes - n) <= outblock.len) {
+			memcpy(rawkey + n, outblock.data, (keybytes - n));
+			break;
+		}
+
+		memcpy(rawkey + n, outblock.data, outblock.len);
+		memcpy(inblock.data, outblock.data, outblock.len);
+		n += outblock.len;
+	}
+
+	/* postprocess the key */
+
+	inblock.data = (char *) rawkey;
+	inblock.len = keybytes;
+
+	BUG_ON(gk5e->mk_key == NULL);
+	ret = (*(gk5e->mk_key))(gk5e, &inblock, outkey);
+	if (ret) {
+		dprintk("%s: got %d from mk_key function for '%s'\n",
+			__func__, ret, gk5e->encrypt_name);
+		goto err_free_raw;
+	}
+
+	/* clean memory, free resources and exit */
+
+	ret = 0;
+
+err_free_raw:
+	memset(rawkey, 0, keybytes);
+	kfree(rawkey);
+err_free_out:
+	memset(outblockdata, 0, blocksize);
+	kfree(outblockdata);
+err_free_in:
+	memset(inblockdata, 0, blocksize);
+	kfree(inblockdata);
+err_free_cipher:
+	crypto_free_blkcipher(cipher);
+err_return:
+	return ret;
+}
+
+#define smask(step) ((1<<step)-1)
+#define pstep(x, step) (((x)&smask(step))^(((x)>>step)&smask(step)))
+#define parity_char(x) pstep(pstep(pstep((x), 4), 2), 1)
+
+static void mit_des_fixup_key_parity(u8 key[8])
+{
+	int i;
+	for (i = 0; i < 8; i++) {
+		key[i] &= 0xfe;
+		key[i] |= 1^parity_char(key[i]);
+	}
+}
+
+/*
+ * This is the des3 key derivation postprocess function
+ */
+u32 gss_krb5_des3_make_key(const struct gss_krb5_enctype *gk5e,
+			   struct xdr_netobj *randombits,
+			   struct xdr_netobj *key)
+{
+	int i;
+	u32 ret = EINVAL;
+
+	if (key->len != 24) {
+		dprintk("%s: key->len is %d\n", __func__, key->len);
+		goto err_out;
+	}
+	if (randombits->len != 21) {
+		dprintk("%s: randombits->len is %d\n",
+			__func__, randombits->len);
+		goto err_out;
+	}
+
+	/* take the seven bytes, move them around into the top 7 bits of the
+	   8 key bytes, then compute the parity bits.  Do this three times. */
+
+	for (i = 0; i < 3; i++) {
+		memcpy(key->data + i*8, randombits->data + i*7, 7);
+		key->data[i*8+7] = (((key->data[i*8]&1)<<1) |
+				    ((key->data[i*8+1]&1)<<2) |
+				    ((key->data[i*8+2]&1)<<3) |
+				    ((key->data[i*8+3]&1)<<4) |
+				    ((key->data[i*8+4]&1)<<5) |
+				    ((key->data[i*8+5]&1)<<6) |
+				    ((key->data[i*8+6]&1)<<7));
+
+		mit_des_fixup_key_parity(key->data + i*8);
+	}
+	ret = 0;
+err_out:
+	return ret;
+}
+
+/*
+ * This is the aes key derivation postprocess function
+ */
+u32 gss_krb5_aes_make_key(const struct gss_krb5_enctype *gk5e,
+			  struct xdr_netobj *randombits,
+			  struct xdr_netobj *key)
+{
+	u32 ret = EINVAL;
+
+	if (key->len != 16 && key->len != 32) {
+		dprintk("%s: key->len is %d\n", __func__, key->len);
+		goto err_out;
+	}
+	if (randombits->len != 16 && randombits->len != 32) {
+		dprintk("%s: randombits->len is %d\n",
+			__func__, randombits->len);
+		goto err_out;
+	}
+	if (randombits->len != key->len) {
+		dprintk("%s: randombits->len is %d, key->len is %d\n",
+			__func__, randombits->len, key->len);
+		goto err_out;
+	}
+	memcpy(key->data, randombits->data, key->len);
+	ret = 0;
+err_out:
+	return ret;
+}
+
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c
new file mode 100644
index 000000000..28db442a0
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -0,0 +1,788 @@
+/*
+ *  linux/net/sunrpc/gss_krb5_mech.c
+ *
+ *  Copyright (c) 2001-2008 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson <andros@umich.edu>
+ *  J. Bruce Fields <bfields@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/sunrpc/auth.h>
+#include <linux/sunrpc/gss_krb5.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/crypto.h>
+#include <linux/sunrpc/gss_krb5_enctypes.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_AUTH
+#endif
+
+static struct gss_api_mech gss_kerberos_mech;	/* forward declaration */
+
+static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
+	/*
+	 * DES (All DES enctypes are mapped to the same gss functionality)
+	 */
+	{
+	  .etype = ENCTYPE_DES_CBC_RAW,
+	  .ctype = CKSUMTYPE_RSA_MD5,
+	  .name = "des-cbc-crc",
+	  .encrypt_name = "cbc(des)",
+	  .cksum_name = "md5",
+	  .encrypt = krb5_encrypt,
+	  .decrypt = krb5_decrypt,
+	  .mk_key = NULL,
+	  .signalg = SGN_ALG_DES_MAC_MD5,
+	  .sealalg = SEAL_ALG_DES,
+	  .keybytes = 7,
+	  .keylength = 8,
+	  .blocksize = 8,
+	  .conflen = 8,
+	  .cksumlength = 8,
+	  .keyed_cksum = 0,
+	},
+	/*
+	 * RC4-HMAC
+	 */
+	{
+	  .etype = ENCTYPE_ARCFOUR_HMAC,
+	  .ctype = CKSUMTYPE_HMAC_MD5_ARCFOUR,
+	  .name = "rc4-hmac",
+	  .encrypt_name = "ecb(arc4)",
+	  .cksum_name = "hmac(md5)",
+	  .encrypt = krb5_encrypt,
+	  .decrypt = krb5_decrypt,
+	  .mk_key = NULL,
+	  .signalg = SGN_ALG_HMAC_MD5,
+	  .sealalg = SEAL_ALG_MICROSOFT_RC4,
+	  .keybytes = 16,
+	  .keylength = 16,
+	  .blocksize = 1,
+	  .conflen = 8,
+	  .cksumlength = 8,
+	  .keyed_cksum = 1,
+	},
+	/*
+	 * 3DES
+	 */
+	{
+	  .etype = ENCTYPE_DES3_CBC_RAW,
+	  .ctype = CKSUMTYPE_HMAC_SHA1_DES3,
+	  .name = "des3-hmac-sha1",
+	  .encrypt_name = "cbc(des3_ede)",
+	  .cksum_name = "hmac(sha1)",
+	  .encrypt = krb5_encrypt,
+	  .decrypt = krb5_decrypt,
+	  .mk_key = gss_krb5_des3_make_key,
+	  .signalg = SGN_ALG_HMAC_SHA1_DES3_KD,
+	  .sealalg = SEAL_ALG_DES3KD,
+	  .keybytes = 21,
+	  .keylength = 24,
+	  .blocksize = 8,
+	  .conflen = 8,
+	  .cksumlength = 20,
+	  .keyed_cksum = 1,
+	},
+	/*
+	 * AES128
+	 */
+	{
+	  .etype = ENCTYPE_AES128_CTS_HMAC_SHA1_96,
+	  .ctype = CKSUMTYPE_HMAC_SHA1_96_AES128,
+	  .name = "aes128-cts",
+	  .encrypt_name = "cts(cbc(aes))",
+	  .cksum_name = "hmac(sha1)",
+	  .encrypt = krb5_encrypt,
+	  .decrypt = krb5_decrypt,
+	  .mk_key = gss_krb5_aes_make_key,
+	  .encrypt_v2 = gss_krb5_aes_encrypt,
+	  .decrypt_v2 = gss_krb5_aes_decrypt,
+	  .signalg = -1,
+	  .sealalg = -1,
+	  .keybytes = 16,
+	  .keylength = 16,
+	  .blocksize = 16,
+	  .conflen = 16,
+	  .cksumlength = 12,
+	  .keyed_cksum = 1,
+	},
+	/*
+	 * AES256
+	 */
+	{
+	  .etype = ENCTYPE_AES256_CTS_HMAC_SHA1_96,
+	  .ctype = CKSUMTYPE_HMAC_SHA1_96_AES256,
+	  .name = "aes256-cts",
+	  .encrypt_name = "cts(cbc(aes))",
+	  .cksum_name = "hmac(sha1)",
+	  .encrypt = krb5_encrypt,
+	  .decrypt = krb5_decrypt,
+	  .mk_key = gss_krb5_aes_make_key,
+	  .encrypt_v2 = gss_krb5_aes_encrypt,
+	  .decrypt_v2 = gss_krb5_aes_decrypt,
+	  .signalg = -1,
+	  .sealalg = -1,
+	  .keybytes = 32,
+	  .keylength = 32,
+	  .blocksize = 16,
+	  .conflen = 16,
+	  .cksumlength = 12,
+	  .keyed_cksum = 1,
+	},
+};
+
+static const int num_supported_enctypes =
+	ARRAY_SIZE(supported_gss_krb5_enctypes);
+
+static int
+supported_gss_krb5_enctype(int etype)
+{
+	int i;
+	for (i = 0; i < num_supported_enctypes; i++)
+		if (supported_gss_krb5_enctypes[i].etype == etype)
+			return 1;
+	return 0;
+}
+
+static const struct gss_krb5_enctype *
+get_gss_krb5_enctype(int etype)
+{
+	int i;
+	for (i = 0; i < num_supported_enctypes; i++)
+		if (supported_gss_krb5_enctypes[i].etype == etype)
+			return &supported_gss_krb5_enctypes[i];
+	return NULL;
+}
+
+static const void *
+simple_get_bytes(const void *p, const void *end, void *res, int len)
+{
+	const void *q = (const void *)((const char *)p + len);
+	if (unlikely(q > end || q < p))
+		return ERR_PTR(-EFAULT);
+	memcpy(res, p, len);
+	return q;
+}
+
+static const void *
+simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res)
+{
+	const void *q;
+	unsigned int len;
+
+	p = simple_get_bytes(p, end, &len, sizeof(len));
+	if (IS_ERR(p))
+		return p;
+	q = (const void *)((const char *)p + len);
+	if (unlikely(q > end || q < p))
+		return ERR_PTR(-EFAULT);
+	res->data = kmemdup(p, len, GFP_NOFS);
+	if (unlikely(res->data == NULL))
+		return ERR_PTR(-ENOMEM);
+	res->len = len;
+	return q;
+}
+
+static inline const void *
+get_key(const void *p, const void *end,
+	struct krb5_ctx *ctx, struct crypto_blkcipher **res)
+{
+	struct xdr_netobj	key;
+	int			alg;
+
+	p = simple_get_bytes(p, end, &alg, sizeof(alg));
+	if (IS_ERR(p))
+		goto out_err;
+
+	switch (alg) {
+	case ENCTYPE_DES_CBC_CRC:
+	case ENCTYPE_DES_CBC_MD4:
+	case ENCTYPE_DES_CBC_MD5:
+		/* Map all these key types to ENCTYPE_DES_CBC_RAW */
+		alg = ENCTYPE_DES_CBC_RAW;
+		break;
+	}
+
+	if (!supported_gss_krb5_enctype(alg)) {
+		printk(KERN_WARNING "gss_kerberos_mech: unsupported "
+			"encryption key algorithm %d\n", alg);
+		p = ERR_PTR(-EINVAL);
+		goto out_err;
+	}
+	p = simple_get_netobj(p, end, &key);
+	if (IS_ERR(p))
+		goto out_err;
+
+	*res = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
+							CRYPTO_ALG_ASYNC);
+	if (IS_ERR(*res)) {
+		printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
+			"crypto algorithm %s\n", ctx->gk5e->encrypt_name);
+		*res = NULL;
+		goto out_err_free_key;
+	}
+	if (crypto_blkcipher_setkey(*res, key.data, key.len)) {
+		printk(KERN_WARNING "gss_kerberos_mech: error setting key for "
+			"crypto algorithm %s\n", ctx->gk5e->encrypt_name);
+		goto out_err_free_tfm;
+	}
+
+	kfree(key.data);
+	return p;
+
+out_err_free_tfm:
+	crypto_free_blkcipher(*res);
+out_err_free_key:
+	kfree(key.data);
+	p = ERR_PTR(-EINVAL);
+out_err:
+	return p;
+}
+
+static int
+gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
+{
+	int tmp;
+
+	p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
+	if (IS_ERR(p))
+		goto out_err;
+
+	/* Old format supports only DES!  Any other enctype uses new format */
+	ctx->enctype = ENCTYPE_DES_CBC_RAW;
+
+	ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
+	if (ctx->gk5e == NULL) {
+		p = ERR_PTR(-EINVAL);
+		goto out_err;
+	}
+
+	/* The downcall format was designed before we completely understood
+	 * the uses of the context fields; so it includes some stuff we
+	 * just give some minimal sanity-checking, and some we ignore
+	 * completely (like the next twenty bytes): */
+	if (unlikely(p + 20 > end || p + 20 < p)) {
+		p = ERR_PTR(-EFAULT);
+		goto out_err;
+	}
+	p += 20;
+	p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
+	if (IS_ERR(p))
+		goto out_err;
+	if (tmp != SGN_ALG_DES_MAC_MD5) {
+		p = ERR_PTR(-ENOSYS);
+		goto out_err;
+	}
+	p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
+	if (IS_ERR(p))
+		goto out_err;
+	if (tmp != SEAL_ALG_DES) {
+		p = ERR_PTR(-ENOSYS);
+		goto out_err;
+	}
+	p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
+	if (IS_ERR(p))
+		goto out_err;
+	p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
+	if (IS_ERR(p))
+		goto out_err;
+	p = simple_get_netobj(p, end, &ctx->mech_used);
+	if (IS_ERR(p))
+		goto out_err;
+	p = get_key(p, end, ctx, &ctx->enc);
+	if (IS_ERR(p))
+		goto out_err_free_mech;
+	p = get_key(p, end, ctx, &ctx->seq);
+	if (IS_ERR(p))
+		goto out_err_free_key1;
+	if (p != end) {
+		p = ERR_PTR(-EFAULT);
+		goto out_err_free_key2;
+	}
+
+	return 0;
+
+out_err_free_key2:
+	crypto_free_blkcipher(ctx->seq);
+out_err_free_key1:
+	crypto_free_blkcipher(ctx->enc);
+out_err_free_mech:
+	kfree(ctx->mech_used.data);
+out_err:
+	return PTR_ERR(p);
+}
+
+static struct crypto_blkcipher *
+context_v2_alloc_cipher(struct krb5_ctx *ctx, const char *cname, u8 *key)
+{
+	struct crypto_blkcipher *cp;
+
+	cp = crypto_alloc_blkcipher(cname, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(cp)) {
+		dprintk("gss_kerberos_mech: unable to initialize "
+			"crypto algorithm %s\n", cname);
+		return NULL;
+	}
+	if (crypto_blkcipher_setkey(cp, key, ctx->gk5e->keylength)) {
+		dprintk("gss_kerberos_mech: error setting key for "
+			"crypto algorithm %s\n", cname);
+		crypto_free_blkcipher(cp);
+		return NULL;
+	}
+	return cp;
+}
+
+static inline void
+set_cdata(u8 cdata[GSS_KRB5_K5CLENGTH], u32 usage, u8 seed)
+{
+	cdata[0] = (usage>>24)&0xff;
+	cdata[1] = (usage>>16)&0xff;
+	cdata[2] = (usage>>8)&0xff;
+	cdata[3] = usage&0xff;
+	cdata[4] = seed;
+}
+
+static int
+context_derive_keys_des3(struct krb5_ctx *ctx, gfp_t gfp_mask)
+{
+	struct xdr_netobj c, keyin, keyout;
+	u8 cdata[GSS_KRB5_K5CLENGTH];
+	u32 err;
+
+	c.len = GSS_KRB5_K5CLENGTH;
+	c.data = cdata;
+
+	keyin.data = ctx->Ksess;
+	keyin.len = ctx->gk5e->keylength;
+	keyout.len = ctx->gk5e->keylength;
+
+	/* seq uses the raw key */
+	ctx->seq = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
+					   ctx->Ksess);
+	if (ctx->seq == NULL)
+		goto out_err;
+
+	ctx->enc = context_v2_alloc_cipher(ctx, ctx->gk5e->encrypt_name,
+					   ctx->Ksess);
+	if (ctx->enc == NULL)
+		goto out_free_seq;
+
+	/* derive cksum */
+	set_cdata(cdata, KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM);
+	keyout.data = ctx->cksum;
+	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
+	if (err) {
+		dprintk("%s: Error %d deriving cksum key\n",
+			__func__, err);
+		goto out_free_enc;
+	}
+
+	return 0;
+
+out_free_enc:
+	crypto_free_blkcipher(ctx->enc);
+out_free_seq:
+	crypto_free_blkcipher(ctx->seq);
+out_err:
+	return -EINVAL;
+}
+
+/*
+ * Note that RC4 depends on deriving keys using the sequence
+ * number or the checksum of a token.  Therefore, the final keys
+ * cannot be calculated until the token is being constructed!
+ */
+static int
+context_derive_keys_rc4(struct krb5_ctx *ctx)
+{
+	struct crypto_hash *hmac;
+	char sigkeyconstant[] = "signaturekey";
+	int slen = strlen(sigkeyconstant) + 1;	/* include null terminator */
+	struct hash_desc desc;
+	struct scatterlist sg[1];
+	int err;
+
+	dprintk("RPC:       %s: entered\n", __func__);
+	/*
+	 * derive cksum (aka Ksign) key
+	 */
+	hmac = crypto_alloc_hash(ctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(hmac)) {
+		dprintk("%s: error %ld allocating hash '%s'\n",
+			__func__, PTR_ERR(hmac), ctx->gk5e->cksum_name);
+		err = PTR_ERR(hmac);
+		goto out_err;
+	}
+
+	err = crypto_hash_setkey(hmac, ctx->Ksess, ctx->gk5e->keylength);
+	if (err)
+		goto out_err_free_hmac;
+
+	sg_init_table(sg, 1);
+	sg_set_buf(sg, sigkeyconstant, slen);
+
+	desc.tfm = hmac;
+	desc.flags = 0;
+
+	err = crypto_hash_init(&desc);
+	if (err)
+		goto out_err_free_hmac;
+
+	err = crypto_hash_digest(&desc, sg, slen, ctx->cksum);
+	if (err)
+		goto out_err_free_hmac;
+	/*
+	 * allocate hash, and blkciphers for data and seqnum encryption
+	 */
+	ctx->enc = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
+					  CRYPTO_ALG_ASYNC);
+	if (IS_ERR(ctx->enc)) {
+		err = PTR_ERR(ctx->enc);
+		goto out_err_free_hmac;
+	}
+
+	ctx->seq = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
+					  CRYPTO_ALG_ASYNC);
+	if (IS_ERR(ctx->seq)) {
+		crypto_free_blkcipher(ctx->enc);
+		err = PTR_ERR(ctx->seq);
+		goto out_err_free_hmac;
+	}
+
+	dprintk("RPC:       %s: returning success\n", __func__);
+
+	err = 0;
+
+out_err_free_hmac:
+	crypto_free_hash(hmac);
+out_err:
+	dprintk("RPC:       %s: returning %d\n", __func__, err);
+	return err;
+}
+
+static int
+context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
+{
+	struct xdr_netobj c, keyin, keyout;
+	u8 cdata[GSS_KRB5_K5CLENGTH];
+	u32 err;
+
+	c.len = GSS_KRB5_K5CLENGTH;
+	c.data = cdata;
+
+	keyin.data = ctx->Ksess;
+	keyin.len = ctx->gk5e->keylength;
+	keyout.len = ctx->gk5e->keylength;
+
+	/* initiator seal encryption */
+	set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
+	keyout.data = ctx->initiator_seal;
+	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
+	if (err) {
+		dprintk("%s: Error %d deriving initiator_seal key\n",
+			__func__, err);
+		goto out_err;
+	}
+	ctx->initiator_enc = context_v2_alloc_cipher(ctx,
+						     ctx->gk5e->encrypt_name,
+						     ctx->initiator_seal);
+	if (ctx->initiator_enc == NULL)
+		goto out_err;
+
+	/* acceptor seal encryption */
+	set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
+	keyout.data = ctx->acceptor_seal;
+	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
+	if (err) {
+		dprintk("%s: Error %d deriving acceptor_seal key\n",
+			__func__, err);
+		goto out_free_initiator_enc;
+	}
+	ctx->acceptor_enc = context_v2_alloc_cipher(ctx,
+						    ctx->gk5e->encrypt_name,
+						    ctx->acceptor_seal);
+	if (ctx->acceptor_enc == NULL)
+		goto out_free_initiator_enc;
+
+	/* initiator sign checksum */
+	set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
+	keyout.data = ctx->initiator_sign;
+	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
+	if (err) {
+		dprintk("%s: Error %d deriving initiator_sign key\n",
+			__func__, err);
+		goto out_free_acceptor_enc;
+	}
+
+	/* acceptor sign checksum */
+	set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
+	keyout.data = ctx->acceptor_sign;
+	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
+	if (err) {
+		dprintk("%s: Error %d deriving acceptor_sign key\n",
+			__func__, err);
+		goto out_free_acceptor_enc;
+	}
+
+	/* initiator seal integrity */
+	set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
+	keyout.data = ctx->initiator_integ;
+	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
+	if (err) {
+		dprintk("%s: Error %d deriving initiator_integ key\n",
+			__func__, err);
+		goto out_free_acceptor_enc;
+	}
+
+	/* acceptor seal integrity */
+	set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
+	keyout.data = ctx->acceptor_integ;
+	err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
+	if (err) {
+		dprintk("%s: Error %d deriving acceptor_integ key\n",
+			__func__, err);
+		goto out_free_acceptor_enc;
+	}
+
+	switch (ctx->enctype) {
+	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+		ctx->initiator_enc_aux =
+			context_v2_alloc_cipher(ctx, "cbc(aes)",
+						ctx->initiator_seal);
+		if (ctx->initiator_enc_aux == NULL)
+			goto out_free_acceptor_enc;
+		ctx->acceptor_enc_aux =
+			context_v2_alloc_cipher(ctx, "cbc(aes)",
+						ctx->acceptor_seal);
+		if (ctx->acceptor_enc_aux == NULL) {
+			crypto_free_blkcipher(ctx->initiator_enc_aux);
+			goto out_free_acceptor_enc;
+		}
+	}
+
+	return 0;
+
+out_free_acceptor_enc:
+	crypto_free_blkcipher(ctx->acceptor_enc);
+out_free_initiator_enc:
+	crypto_free_blkcipher(ctx->initiator_enc);
+out_err:
+	return -EINVAL;
+}
+
+static int
+gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
+		gfp_t gfp_mask)
+{
+	int keylen;
+
+	p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags));
+	if (IS_ERR(p))
+		goto out_err;
+	ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
+
+	p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
+	if (IS_ERR(p))
+		goto out_err;
+	p = simple_get_bytes(p, end, &ctx->seq_send64, sizeof(ctx->seq_send64));
+	if (IS_ERR(p))
+		goto out_err;
+	/* set seq_send for use by "older" enctypes */
+	ctx->seq_send = ctx->seq_send64;
+	if (ctx->seq_send64 != ctx->seq_send) {
+		dprintk("%s: seq_send64 %lx, seq_send %x overflow?\n", __func__,
+			(unsigned long)ctx->seq_send64, ctx->seq_send);
+		p = ERR_PTR(-EINVAL);
+		goto out_err;
+	}
+	p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype));
+	if (IS_ERR(p))
+		goto out_err;
+	/* Map ENCTYPE_DES3_CBC_SHA1 to ENCTYPE_DES3_CBC_RAW */
+	if (ctx->enctype == ENCTYPE_DES3_CBC_SHA1)
+		ctx->enctype = ENCTYPE_DES3_CBC_RAW;
+	ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
+	if (ctx->gk5e == NULL) {
+		dprintk("gss_kerberos_mech: unsupported krb5 enctype %u\n",
+			ctx->enctype);
+		p = ERR_PTR(-EINVAL);
+		goto out_err;
+	}
+	keylen = ctx->gk5e->keylength;
+
+	p = simple_get_bytes(p, end, ctx->Ksess, keylen);
+	if (IS_ERR(p))
+		goto out_err;
+
+	if (p != end) {
+		p = ERR_PTR(-EINVAL);
+		goto out_err;
+	}
+
+	ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data,
+				      gss_kerberos_mech.gm_oid.len, gfp_mask);
+	if (unlikely(ctx->mech_used.data == NULL)) {
+		p = ERR_PTR(-ENOMEM);
+		goto out_err;
+	}
+	ctx->mech_used.len = gss_kerberos_mech.gm_oid.len;
+
+	switch (ctx->enctype) {
+	case ENCTYPE_DES3_CBC_RAW:
+		return context_derive_keys_des3(ctx, gfp_mask);
+	case ENCTYPE_ARCFOUR_HMAC:
+		return context_derive_keys_rc4(ctx);
+	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+		return context_derive_keys_new(ctx, gfp_mask);
+	default:
+		return -EINVAL;
+	}
+
+out_err:
+	return PTR_ERR(p);
+}
+
+static int
+gss_import_sec_context_kerberos(const void *p, size_t len,
+				struct gss_ctx *ctx_id,
+				time_t *endtime,
+				gfp_t gfp_mask)
+{
+	const void *end = (const void *)((const char *)p + len);
+	struct  krb5_ctx *ctx;
+	int ret;
+
+	ctx = kzalloc(sizeof(*ctx), gfp_mask);
+	if (ctx == NULL)
+		return -ENOMEM;
+
+	if (len == 85)
+		ret = gss_import_v1_context(p, end, ctx);
+	else
+		ret = gss_import_v2_context(p, end, ctx, gfp_mask);
+
+	if (ret == 0) {
+		ctx_id->internal_ctx_id = ctx;
+		if (endtime)
+			*endtime = ctx->endtime;
+	} else
+		kfree(ctx);
+
+	dprintk("RPC:       %s: returning %d\n", __func__, ret);
+	return ret;
+}
+
+static void
+gss_delete_sec_context_kerberos(void *internal_ctx) {
+	struct krb5_ctx *kctx = internal_ctx;
+
+	crypto_free_blkcipher(kctx->seq);
+	crypto_free_blkcipher(kctx->enc);
+	crypto_free_blkcipher(kctx->acceptor_enc);
+	crypto_free_blkcipher(kctx->initiator_enc);
+	crypto_free_blkcipher(kctx->acceptor_enc_aux);
+	crypto_free_blkcipher(kctx->initiator_enc_aux);
+	kfree(kctx->mech_used.data);
+	kfree(kctx);
+}
+
+static const struct gss_api_ops gss_kerberos_ops = {
+	.gss_import_sec_context	= gss_import_sec_context_kerberos,
+	.gss_get_mic		= gss_get_mic_kerberos,
+	.gss_verify_mic		= gss_verify_mic_kerberos,
+	.gss_wrap		= gss_wrap_kerberos,
+	.gss_unwrap		= gss_unwrap_kerberos,
+	.gss_delete_sec_context	= gss_delete_sec_context_kerberos,
+};
+
+static struct pf_desc gss_kerberos_pfs[] = {
+	[0] = {
+		.pseudoflavor = RPC_AUTH_GSS_KRB5,
+		.qop = GSS_C_QOP_DEFAULT,
+		.service = RPC_GSS_SVC_NONE,
+		.name = "krb5",
+	},
+	[1] = {
+		.pseudoflavor = RPC_AUTH_GSS_KRB5I,
+		.qop = GSS_C_QOP_DEFAULT,
+		.service = RPC_GSS_SVC_INTEGRITY,
+		.name = "krb5i",
+	},
+	[2] = {
+		.pseudoflavor = RPC_AUTH_GSS_KRB5P,
+		.qop = GSS_C_QOP_DEFAULT,
+		.service = RPC_GSS_SVC_PRIVACY,
+		.name = "krb5p",
+	},
+};
+
+MODULE_ALIAS("rpc-auth-gss-krb5");
+MODULE_ALIAS("rpc-auth-gss-krb5i");
+MODULE_ALIAS("rpc-auth-gss-krb5p");
+MODULE_ALIAS("rpc-auth-gss-390003");
+MODULE_ALIAS("rpc-auth-gss-390004");
+MODULE_ALIAS("rpc-auth-gss-390005");
+MODULE_ALIAS("rpc-auth-gss-1.2.840.113554.1.2.2");
+
+static struct gss_api_mech gss_kerberos_mech = {
+	.gm_name	= "krb5",
+	.gm_owner	= THIS_MODULE,
+	.gm_oid		= { 9, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02" },
+	.gm_ops		= &gss_kerberos_ops,
+	.gm_pf_num	= ARRAY_SIZE(gss_kerberos_pfs),
+	.gm_pfs		= gss_kerberos_pfs,
+	.gm_upcall_enctypes = KRB5_SUPPORTED_ENCTYPES,
+};
+
+static int __init init_kerberos_module(void)
+{
+	int status;
+
+	status = gss_mech_register(&gss_kerberos_mech);
+	if (status)
+		printk("Failed to register kerberos gss mechanism!\n");
+	return status;
+}
+
+static void __exit cleanup_kerberos_module(void)
+{
+	gss_mech_unregister(&gss_kerberos_mech);
+}
+
+MODULE_LICENSE("GPL");
+module_init(init_kerberos_module);
+module_exit(cleanup_kerberos_module);
diff --git a/net/sunrpc/auth_gss/gss_krb5_seal.c b/net/sunrpc/auth_gss/gss_krb5_seal.c
new file mode 100644
index 000000000..1d74d653e
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_krb5_seal.c
@@ -0,0 +1,229 @@
+/*
+ *  linux/net/sunrpc/gss_krb5_seal.c
+ *
+ *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5seal.c
+ *
+ *  Copyright (c) 2000-2008 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson	<andros@umich.edu>
+ *  J. Bruce Fields	<bfields@umich.edu>
+ */
+
+/*
+ * Copyright 1993 by OpenVision Technologies, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appears in all copies and
+ * that both that copyright notice and this permission notice appear in
+ * supporting documentation, and that the name of OpenVision not be used
+ * in advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission. OpenVision makes no
+ * representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
+ * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * Copyright (C) 1998 by the FundsXpress, INC.
+ *
+ * All rights reserved.
+ *
+ * Export of this software from the United States of America may require
+ * a specific license from the United States Government.  It is the
+ * responsibility of any person or organization contemplating export to
+ * obtain such a license before exporting.
+ *
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of FundsXpress. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  FundsXpress makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include <linux/types.h>
+#include <linux/jiffies.h>
+#include <linux/sunrpc/gss_krb5.h>
+#include <linux/random.h>
+#include <linux/crypto.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY        RPCDBG_AUTH
+#endif
+
+DEFINE_SPINLOCK(krb5_seq_lock);
+
+static void *
+setup_token(struct krb5_ctx *ctx, struct xdr_netobj *token)
+{
+	u16 *ptr;
+	void *krb5_hdr;
+	int body_size = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength;
+
+	token->len = g_token_size(&ctx->mech_used, body_size);
+
+	ptr = (u16 *)token->data;
+	g_make_token_header(&ctx->mech_used, body_size, (unsigned char **)&ptr);
+
+	/* ptr now at start of header described in rfc 1964, section 1.2.1: */
+	krb5_hdr = ptr;
+	*ptr++ = KG_TOK_MIC_MSG;
+	/*
+	 * signalg is stored as if it were converted from LE to host endian, even
+	 * though it's an opaque pair of bytes according to the RFC.
+	 */
+	*ptr++ = (__force u16)cpu_to_le16(ctx->gk5e->signalg);
+	*ptr++ = SEAL_ALG_NONE;
+	*ptr = 0xffff;
+
+	return krb5_hdr;
+}
+
+static void *
+setup_token_v2(struct krb5_ctx *ctx, struct xdr_netobj *token)
+{
+	u16 *ptr;
+	void *krb5_hdr;
+	u8 *p, flags = 0x00;
+
+	if ((ctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0)
+		flags |= 0x01;
+	if (ctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY)
+		flags |= 0x04;
+
+	/* Per rfc 4121, sec 4.2.6.1, there is no header,
+	 * just start the token */
+	krb5_hdr = ptr = (u16 *)token->data;
+
+	*ptr++ = KG2_TOK_MIC;
+	p = (u8 *)ptr;
+	*p++ = flags;
+	*p++ = 0xff;
+	ptr = (u16 *)p;
+	*ptr++ = 0xffff;
+	*ptr = 0xffff;
+
+	token->len = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength;
+	return krb5_hdr;
+}
+
+static u32
+gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text,
+		struct xdr_netobj *token)
+{
+	char			cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
+					    .data = cksumdata};
+	void			*ptr;
+	s32			now;
+	u32			seq_send;
+	u8			*cksumkey;
+
+	dprintk("RPC:       %s\n", __func__);
+	BUG_ON(ctx == NULL);
+
+	now = get_seconds();
+
+	ptr = setup_token(ctx, token);
+
+	if (ctx->gk5e->keyed_cksum)
+		cksumkey = ctx->cksum;
+	else
+		cksumkey = NULL;
+
+	if (make_checksum(ctx, ptr, 8, text, 0, cksumkey,
+			  KG_USAGE_SIGN, &md5cksum))
+		return GSS_S_FAILURE;
+
+	memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len);
+
+	spin_lock(&krb5_seq_lock);
+	seq_send = ctx->seq_send++;
+	spin_unlock(&krb5_seq_lock);
+
+	if (krb5_make_seq_num(ctx, ctx->seq, ctx->initiate ? 0 : 0xff,
+			      seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8))
+		return GSS_S_FAILURE;
+
+	return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
+}
+
+static u32
+gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
+		struct xdr_netobj *token)
+{
+	char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	struct xdr_netobj cksumobj = { .len = sizeof(cksumdata),
+				       .data = cksumdata};
+	void *krb5_hdr;
+	s32 now;
+	u64 seq_send;
+	u8 *cksumkey;
+	unsigned int cksum_usage;
+
+	dprintk("RPC:       %s\n", __func__);
+
+	krb5_hdr = setup_token_v2(ctx, token);
+
+	/* Set up the sequence number. Now 64-bits in clear
+	 * text and w/o direction indicator */
+	spin_lock(&krb5_seq_lock);
+	seq_send = ctx->seq_send64++;
+	spin_unlock(&krb5_seq_lock);
+	*((__be64 *)(krb5_hdr + 8)) = cpu_to_be64(seq_send);
+
+	if (ctx->initiate) {
+		cksumkey = ctx->initiator_sign;
+		cksum_usage = KG_USAGE_INITIATOR_SIGN;
+	} else {
+		cksumkey = ctx->acceptor_sign;
+		cksum_usage = KG_USAGE_ACCEPTOR_SIGN;
+	}
+
+	if (make_checksum_v2(ctx, krb5_hdr, GSS_KRB5_TOK_HDR_LEN,
+			     text, 0, cksumkey, cksum_usage, &cksumobj))
+		return GSS_S_FAILURE;
+
+	memcpy(krb5_hdr + GSS_KRB5_TOK_HDR_LEN, cksumobj.data, cksumobj.len);
+
+	now = get_seconds();
+
+	return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
+}
+
+u32
+gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
+		     struct xdr_netobj *token)
+{
+	struct krb5_ctx		*ctx = gss_ctx->internal_ctx_id;
+
+	switch (ctx->enctype) {
+	default:
+		BUG();
+	case ENCTYPE_DES_CBC_RAW:
+	case ENCTYPE_DES3_CBC_RAW:
+	case ENCTYPE_ARCFOUR_HMAC:
+		return gss_get_mic_v1(ctx, text, token);
+	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+		return gss_get_mic_v2(ctx, text, token);
+	}
+}
+
diff --git a/net/sunrpc/auth_gss/gss_krb5_seqnum.c b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
new file mode 100644
index 000000000..20d55c793
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
@@ -0,0 +1,166 @@
+/*
+ *  linux/net/sunrpc/gss_krb5_seqnum.c
+ *
+ *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/util_seqnum.c
+ *
+ *  Copyright (c) 2000 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson   <andros@umich.edu>
+ */
+
+/*
+ * Copyright 1993 by OpenVision Technologies, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appears in all copies and
+ * that both that copyright notice and this permission notice appear in
+ * supporting documentation, and that the name of OpenVision not be used
+ * in advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission. OpenVision makes no
+ * representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
+ * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <linux/types.h>
+#include <linux/sunrpc/gss_krb5.h>
+#include <linux/crypto.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY        RPCDBG_AUTH
+#endif
+
+static s32
+krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum,
+		      unsigned char *cksum, unsigned char *buf)
+{
+	struct crypto_blkcipher *cipher;
+	unsigned char plain[8];
+	s32 code;
+
+	dprintk("RPC:       %s:\n", __func__);
+	cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0,
+					CRYPTO_ALG_ASYNC);
+	if (IS_ERR(cipher))
+		return PTR_ERR(cipher);
+
+	plain[0] = (unsigned char) ((seqnum >> 24) & 0xff);
+	plain[1] = (unsigned char) ((seqnum >> 16) & 0xff);
+	plain[2] = (unsigned char) ((seqnum >> 8) & 0xff);
+	plain[3] = (unsigned char) ((seqnum >> 0) & 0xff);
+	plain[4] = direction;
+	plain[5] = direction;
+	plain[6] = direction;
+	plain[7] = direction;
+
+	code = krb5_rc4_setup_seq_key(kctx, cipher, cksum);
+	if (code)
+		goto out;
+
+	code = krb5_encrypt(cipher, cksum, plain, buf, 8);
+out:
+	crypto_free_blkcipher(cipher);
+	return code;
+}
+s32
+krb5_make_seq_num(struct krb5_ctx *kctx,
+		struct crypto_blkcipher *key,
+		int direction,
+		u32 seqnum,
+		unsigned char *cksum, unsigned char *buf)
+{
+	unsigned char plain[8];
+
+	if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC)
+		return krb5_make_rc4_seq_num(kctx, direction, seqnum,
+					     cksum, buf);
+
+	plain[0] = (unsigned char) (seqnum & 0xff);
+	plain[1] = (unsigned char) ((seqnum >> 8) & 0xff);
+	plain[2] = (unsigned char) ((seqnum >> 16) & 0xff);
+	plain[3] = (unsigned char) ((seqnum >> 24) & 0xff);
+
+	plain[4] = direction;
+	plain[5] = direction;
+	plain[6] = direction;
+	plain[7] = direction;
+
+	return krb5_encrypt(key, cksum, plain, buf, 8);
+}
+
+static s32
+krb5_get_rc4_seq_num(struct krb5_ctx *kctx, unsigned char *cksum,
+		     unsigned char *buf, int *direction, s32 *seqnum)
+{
+	struct crypto_blkcipher *cipher;
+	unsigned char plain[8];
+	s32 code;
+
+	dprintk("RPC:       %s:\n", __func__);
+	cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0,
+					CRYPTO_ALG_ASYNC);
+	if (IS_ERR(cipher))
+		return PTR_ERR(cipher);
+
+	code = krb5_rc4_setup_seq_key(kctx, cipher, cksum);
+	if (code)
+		goto out;
+
+	code = krb5_decrypt(cipher, cksum, buf, plain, 8);
+	if (code)
+		goto out;
+
+	if ((plain[4] != plain[5]) || (plain[4] != plain[6])
+				   || (plain[4] != plain[7])) {
+		code = (s32)KG_BAD_SEQ;
+		goto out;
+	}
+
+	*direction = plain[4];
+
+	*seqnum = ((plain[0] << 24) | (plain[1] << 16) |
+					(plain[2] << 8) | (plain[3]));
+out:
+	crypto_free_blkcipher(cipher);
+	return code;
+}
+
+s32
+krb5_get_seq_num(struct krb5_ctx *kctx,
+	       unsigned char *cksum,
+	       unsigned char *buf,
+	       int *direction, u32 *seqnum)
+{
+	s32 code;
+	unsigned char plain[8];
+	struct crypto_blkcipher *key = kctx->seq;
+
+	dprintk("RPC:       krb5_get_seq_num:\n");
+
+	if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC)
+		return krb5_get_rc4_seq_num(kctx, cksum, buf,
+					    direction, seqnum);
+
+	if ((code = krb5_decrypt(key, cksum, buf, plain, 8)))
+		return code;
+
+	if ((plain[4] != plain[5]) || (plain[4] != plain[6]) ||
+	    (plain[4] != plain[7]))
+		return (s32)KG_BAD_SEQ;
+
+	*direction = plain[4];
+
+	*seqnum = ((plain[0]) |
+		   (plain[1] << 8) | (plain[2] << 16) | (plain[3] << 24));
+
+	return 0;
+}
diff --git a/net/sunrpc/auth_gss/gss_krb5_unseal.c b/net/sunrpc/auth_gss/gss_krb5_unseal.c
new file mode 100644
index 000000000..dcf9515d9
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_krb5_unseal.c
@@ -0,0 +1,226 @@
+/*
+ *  linux/net/sunrpc/gss_krb5_unseal.c
+ *
+ *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.c
+ *
+ *  Copyright (c) 2000-2008 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson   <andros@umich.edu>
+ */
+
+/*
+ * Copyright 1993 by OpenVision Technologies, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appears in all copies and
+ * that both that copyright notice and this permission notice appear in
+ * supporting documentation, and that the name of OpenVision not be used
+ * in advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission. OpenVision makes no
+ * representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
+ * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * Copyright (C) 1998 by the FundsXpress, INC.
+ *
+ * All rights reserved.
+ *
+ * Export of this software from the United States of America may require
+ * a specific license from the United States Government.  It is the
+ * responsibility of any person or organization contemplating export to
+ * obtain such a license before exporting.
+ *
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of FundsXpress. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  FundsXpress makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include <linux/types.h>
+#include <linux/jiffies.h>
+#include <linux/sunrpc/gss_krb5.h>
+#include <linux/crypto.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY        RPCDBG_AUTH
+#endif
+
+
+/* read_token is a mic token, and message_buffer is the data that the mic was
+ * supposedly taken over. */
+
+static u32
+gss_verify_mic_v1(struct krb5_ctx *ctx,
+		struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
+{
+	int			signalg;
+	int			sealalg;
+	char			cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
+					    .data = cksumdata};
+	s32			now;
+	int			direction;
+	u32			seqnum;
+	unsigned char		*ptr = (unsigned char *)read_token->data;
+	int			bodysize;
+	u8			*cksumkey;
+
+	dprintk("RPC:       krb5_read_token\n");
+
+	if (g_verify_token_header(&ctx->mech_used, &bodysize, &ptr,
+					read_token->len))
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	if ((ptr[0] != ((KG_TOK_MIC_MSG >> 8) & 0xff)) ||
+	    (ptr[1] !=  (KG_TOK_MIC_MSG & 0xff)))
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	/* XXX sanity-check bodysize?? */
+
+	signalg = ptr[2] + (ptr[3] << 8);
+	if (signalg != ctx->gk5e->signalg)
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	sealalg = ptr[4] + (ptr[5] << 8);
+	if (sealalg != SEAL_ALG_NONE)
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	if ((ptr[6] != 0xff) || (ptr[7] != 0xff))
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	if (ctx->gk5e->keyed_cksum)
+		cksumkey = ctx->cksum;
+	else
+		cksumkey = NULL;
+
+	if (make_checksum(ctx, ptr, 8, message_buffer, 0,
+			  cksumkey, KG_USAGE_SIGN, &md5cksum))
+		return GSS_S_FAILURE;
+
+	if (memcmp(md5cksum.data, ptr + GSS_KRB5_TOK_HDR_LEN,
+					ctx->gk5e->cksumlength))
+		return GSS_S_BAD_SIG;
+
+	/* it got through unscathed.  Make sure the context is unexpired */
+
+	now = get_seconds();
+
+	if (now > ctx->endtime)
+		return GSS_S_CONTEXT_EXPIRED;
+
+	/* do sequencing checks */
+
+	if (krb5_get_seq_num(ctx, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8,
+			     &direction, &seqnum))
+		return GSS_S_FAILURE;
+
+	if ((ctx->initiate && direction != 0xff) ||
+	    (!ctx->initiate && direction != 0))
+		return GSS_S_BAD_SIG;
+
+	return GSS_S_COMPLETE;
+}
+
+static u32
+gss_verify_mic_v2(struct krb5_ctx *ctx,
+		struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
+{
+	char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	struct xdr_netobj cksumobj = {.len = sizeof(cksumdata),
+				      .data = cksumdata};
+	s32 now;
+	u8 *ptr = read_token->data;
+	u8 *cksumkey;
+	u8 flags;
+	int i;
+	unsigned int cksum_usage;
+
+	dprintk("RPC:       %s\n", __func__);
+
+	if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_MIC)
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	flags = ptr[2];
+	if ((!ctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) ||
+	    (ctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)))
+		return GSS_S_BAD_SIG;
+
+	if (flags & KG2_TOKEN_FLAG_SEALED) {
+		dprintk("%s: token has unexpected sealed flag\n", __func__);
+		return GSS_S_FAILURE;
+	}
+
+	for (i = 3; i < 8; i++)
+		if (ptr[i] != 0xff)
+			return GSS_S_DEFECTIVE_TOKEN;
+
+	if (ctx->initiate) {
+		cksumkey = ctx->acceptor_sign;
+		cksum_usage = KG_USAGE_ACCEPTOR_SIGN;
+	} else {
+		cksumkey = ctx->initiator_sign;
+		cksum_usage = KG_USAGE_INITIATOR_SIGN;
+	}
+
+	if (make_checksum_v2(ctx, ptr, GSS_KRB5_TOK_HDR_LEN, message_buffer, 0,
+			     cksumkey, cksum_usage, &cksumobj))
+		return GSS_S_FAILURE;
+
+	if (memcmp(cksumobj.data, ptr + GSS_KRB5_TOK_HDR_LEN,
+				ctx->gk5e->cksumlength))
+		return GSS_S_BAD_SIG;
+
+	/* it got through unscathed.  Make sure the context is unexpired */
+	now = get_seconds();
+	if (now > ctx->endtime)
+		return GSS_S_CONTEXT_EXPIRED;
+
+	/*
+	 * NOTE: the sequence number at ptr + 8 is skipped, rpcsec_gss
+	 * doesn't want it checked; see page 6 of rfc 2203.
+	 */
+
+	return GSS_S_COMPLETE;
+}
+
+u32
+gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
+			struct xdr_buf *message_buffer,
+			struct xdr_netobj *read_token)
+{
+	struct krb5_ctx *ctx = gss_ctx->internal_ctx_id;
+
+	switch (ctx->enctype) {
+	default:
+		BUG();
+	case ENCTYPE_DES_CBC_RAW:
+	case ENCTYPE_DES3_CBC_RAW:
+	case ENCTYPE_ARCFOUR_HMAC:
+		return gss_verify_mic_v1(ctx, message_buffer, read_token);
+	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+		return gss_verify_mic_v2(ctx, message_buffer, read_token);
+	}
+}
+
diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c
new file mode 100644
index 000000000..ca7e92a32
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -0,0 +1,626 @@
+/*
+ * COPYRIGHT (c) 2008
+ * The Regents of the University of Michigan
+ * ALL RIGHTS RESERVED
+ *
+ * Permission is granted to use, copy, create derivative works
+ * and redistribute this software and such derivative works
+ * for any purpose, so long as the name of The University of
+ * Michigan is not used in any advertising or publicity
+ * pertaining to the use of distribution of this software
+ * without specific, written prior authorization.  If the
+ * above copyright notice or any other identification of the
+ * University of Michigan is included in any copy of any
+ * portion of this software, then the disclaimer below must
+ * also be included.
+ *
+ * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
+ * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
+ * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
+ * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
+ * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
+ * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
+ * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
+ * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
+ * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGES.
+ */
+
+#include <linux/types.h>
+#include <linux/jiffies.h>
+#include <linux/sunrpc/gss_krb5.h>
+#include <linux/random.h>
+#include <linux/pagemap.h>
+#include <linux/crypto.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_AUTH
+#endif
+
+static inline int
+gss_krb5_padding(int blocksize, int length)
+{
+	return blocksize - (length % blocksize);
+}
+
+static inline void
+gss_krb5_add_padding(struct xdr_buf *buf, int offset, int blocksize)
+{
+	int padding = gss_krb5_padding(blocksize, buf->len - offset);
+	char *p;
+	struct kvec *iov;
+
+	if (buf->page_len || buf->tail[0].iov_len)
+		iov = &buf->tail[0];
+	else
+		iov = &buf->head[0];
+	p = iov->iov_base + iov->iov_len;
+	iov->iov_len += padding;
+	buf->len += padding;
+	memset(p, padding, padding);
+}
+
+static inline int
+gss_krb5_remove_padding(struct xdr_buf *buf, int blocksize)
+{
+	u8 *ptr;
+	u8 pad;
+	size_t len = buf->len;
+
+	if (len <= buf->head[0].iov_len) {
+		pad = *(u8 *)(buf->head[0].iov_base + len - 1);
+		if (pad > buf->head[0].iov_len)
+			return -EINVAL;
+		buf->head[0].iov_len -= pad;
+		goto out;
+	} else
+		len -= buf->head[0].iov_len;
+	if (len <= buf->page_len) {
+		unsigned int last = (buf->page_base + len - 1)
+					>>PAGE_CACHE_SHIFT;
+		unsigned int offset = (buf->page_base + len - 1)
+					& (PAGE_CACHE_SIZE - 1);
+		ptr = kmap_atomic(buf->pages[last]);
+		pad = *(ptr + offset);
+		kunmap_atomic(ptr);
+		goto out;
+	} else
+		len -= buf->page_len;
+	BUG_ON(len > buf->tail[0].iov_len);
+	pad = *(u8 *)(buf->tail[0].iov_base + len - 1);
+out:
+	/* XXX: NOTE: we do not adjust the page lengths--they represent
+	 * a range of data in the real filesystem page cache, and we need
+	 * to know that range so the xdr code can properly place read data.
+	 * However adjusting the head length, as we do above, is harmless.
+	 * In the case of a request that fits into a single page, the server
+	 * also uses length and head length together to determine the original
+	 * start of the request to copy the request for deferal; so it's
+	 * easier on the server if we adjust head and tail length in tandem.
+	 * It's not really a problem that we don't fool with the page and
+	 * tail lengths, though--at worst badly formed xdr might lead the
+	 * server to attempt to parse the padding.
+	 * XXX: Document all these weird requirements for gss mechanism
+	 * wrap/unwrap functions. */
+	if (pad > blocksize)
+		return -EINVAL;
+	if (buf->len > pad)
+		buf->len -= pad;
+	else
+		return -EINVAL;
+	return 0;
+}
+
+void
+gss_krb5_make_confounder(char *p, u32 conflen)
+{
+	static u64 i = 0;
+	u64 *q = (u64 *)p;
+
+	/* rfc1964 claims this should be "random".  But all that's really
+	 * necessary is that it be unique.  And not even that is necessary in
+	 * our case since our "gssapi" implementation exists only to support
+	 * rpcsec_gss, so we know that the only buffers we will ever encrypt
+	 * already begin with a unique sequence number.  Just to hedge my bets
+	 * I'll make a half-hearted attempt at something unique, but ensuring
+	 * uniqueness would mean worrying about atomicity and rollover, and I
+	 * don't care enough. */
+
+	/* initialize to random value */
+	if (i == 0) {
+		i = prandom_u32();
+		i = (i << 32) | prandom_u32();
+	}
+
+	switch (conflen) {
+	case 16:
+		*q++ = i++;
+		/* fall through */
+	case 8:
+		*q++ = i++;
+		break;
+	default:
+		BUG();
+	}
+}
+
+/* Assumptions: the head and tail of inbuf are ours to play with.
+ * The pages, however, may be real pages in the page cache and we replace
+ * them with scratch pages from **pages before writing to them. */
+/* XXX: obviously the above should be documentation of wrap interface,
+ * and shouldn't be in this kerberos-specific file. */
+
+/* XXX factor out common code with seal/unseal. */
+
+static u32
+gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
+		struct xdr_buf *buf, struct page **pages)
+{
+	char			cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
+					    .data = cksumdata};
+	int			blocksize = 0, plainlen;
+	unsigned char		*ptr, *msg_start;
+	s32			now;
+	int			headlen;
+	struct page		**tmp_pages;
+	u32			seq_send;
+	u8			*cksumkey;
+	u32			conflen = kctx->gk5e->conflen;
+
+	dprintk("RPC:       %s\n", __func__);
+
+	now = get_seconds();
+
+	blocksize = crypto_blkcipher_blocksize(kctx->enc);
+	gss_krb5_add_padding(buf, offset, blocksize);
+	BUG_ON((buf->len - offset) % blocksize);
+	plainlen = conflen + buf->len - offset;
+
+	headlen = g_token_size(&kctx->mech_used,
+		GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength + plainlen) -
+		(buf->len - offset);
+
+	ptr = buf->head[0].iov_base + offset;
+	/* shift data to make room for header. */
+	xdr_extend_head(buf, offset, headlen);
+
+	/* XXX Would be cleverer to encrypt while copying. */
+	BUG_ON((buf->len - offset - headlen) % blocksize);
+
+	g_make_token_header(&kctx->mech_used,
+				GSS_KRB5_TOK_HDR_LEN +
+				kctx->gk5e->cksumlength + plainlen, &ptr);
+
+
+	/* ptr now at header described in rfc 1964, section 1.2.1: */
+	ptr[0] = (unsigned char) ((KG_TOK_WRAP_MSG >> 8) & 0xff);
+	ptr[1] = (unsigned char) (KG_TOK_WRAP_MSG & 0xff);
+
+	msg_start = ptr + GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength;
+
+	/*
+	 * signalg and sealalg are stored as if they were converted from LE
+	 * to host endian, even though they're opaque pairs of bytes according
+	 * to the RFC.
+	 */
+	*(__le16 *)(ptr + 2) = cpu_to_le16(kctx->gk5e->signalg);
+	*(__le16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg);
+	ptr[6] = 0xff;
+	ptr[7] = 0xff;
+
+	gss_krb5_make_confounder(msg_start, conflen);
+
+	if (kctx->gk5e->keyed_cksum)
+		cksumkey = kctx->cksum;
+	else
+		cksumkey = NULL;
+
+	/* XXXJBF: UGH!: */
+	tmp_pages = buf->pages;
+	buf->pages = pages;
+	if (make_checksum(kctx, ptr, 8, buf, offset + headlen - conflen,
+					cksumkey, KG_USAGE_SEAL, &md5cksum))
+		return GSS_S_FAILURE;
+	buf->pages = tmp_pages;
+
+	memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len);
+
+	spin_lock(&krb5_seq_lock);
+	seq_send = kctx->seq_send++;
+	spin_unlock(&krb5_seq_lock);
+
+	/* XXX would probably be more efficient to compute checksum
+	 * and encrypt at the same time: */
+	if ((krb5_make_seq_num(kctx, kctx->seq, kctx->initiate ? 0 : 0xff,
+			       seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8)))
+		return GSS_S_FAILURE;
+
+	if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) {
+		struct crypto_blkcipher *cipher;
+		int err;
+		cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0,
+						CRYPTO_ALG_ASYNC);
+		if (IS_ERR(cipher))
+			return GSS_S_FAILURE;
+
+		krb5_rc4_setup_enc_key(kctx, cipher, seq_send);
+
+		err = gss_encrypt_xdr_buf(cipher, buf,
+					  offset + headlen - conflen, pages);
+		crypto_free_blkcipher(cipher);
+		if (err)
+			return GSS_S_FAILURE;
+	} else {
+		if (gss_encrypt_xdr_buf(kctx->enc, buf,
+					offset + headlen - conflen, pages))
+			return GSS_S_FAILURE;
+	}
+
+	return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
+}
+
+static u32
+gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
+{
+	int			signalg;
+	int			sealalg;
+	char			cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
+					    .data = cksumdata};
+	s32			now;
+	int			direction;
+	s32			seqnum;
+	unsigned char		*ptr;
+	int			bodysize;
+	void			*data_start, *orig_start;
+	int			data_len;
+	int			blocksize;
+	u32			conflen = kctx->gk5e->conflen;
+	int			crypt_offset;
+	u8			*cksumkey;
+
+	dprintk("RPC:       gss_unwrap_kerberos\n");
+
+	ptr = (u8 *)buf->head[0].iov_base + offset;
+	if (g_verify_token_header(&kctx->mech_used, &bodysize, &ptr,
+					buf->len - offset))
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	if ((ptr[0] != ((KG_TOK_WRAP_MSG >> 8) & 0xff)) ||
+	    (ptr[1] !=  (KG_TOK_WRAP_MSG & 0xff)))
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	/* XXX sanity-check bodysize?? */
+
+	/* get the sign and seal algorithms */
+
+	signalg = ptr[2] + (ptr[3] << 8);
+	if (signalg != kctx->gk5e->signalg)
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	sealalg = ptr[4] + (ptr[5] << 8);
+	if (sealalg != kctx->gk5e->sealalg)
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	if ((ptr[6] != 0xff) || (ptr[7] != 0xff))
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	/*
+	 * Data starts after token header and checksum.  ptr points
+	 * to the beginning of the token header
+	 */
+	crypt_offset = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) -
+					(unsigned char *)buf->head[0].iov_base;
+
+	/*
+	 * Need plaintext seqnum to derive encryption key for arcfour-hmac
+	 */
+	if (krb5_get_seq_num(kctx, ptr + GSS_KRB5_TOK_HDR_LEN,
+			     ptr + 8, &direction, &seqnum))
+		return GSS_S_BAD_SIG;
+
+	if ((kctx->initiate && direction != 0xff) ||
+	    (!kctx->initiate && direction != 0))
+		return GSS_S_BAD_SIG;
+
+	if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) {
+		struct crypto_blkcipher *cipher;
+		int err;
+
+		cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0,
+						CRYPTO_ALG_ASYNC);
+		if (IS_ERR(cipher))
+			return GSS_S_FAILURE;
+
+		krb5_rc4_setup_enc_key(kctx, cipher, seqnum);
+
+		err = gss_decrypt_xdr_buf(cipher, buf, crypt_offset);
+		crypto_free_blkcipher(cipher);
+		if (err)
+			return GSS_S_DEFECTIVE_TOKEN;
+	} else {
+		if (gss_decrypt_xdr_buf(kctx->enc, buf, crypt_offset))
+			return GSS_S_DEFECTIVE_TOKEN;
+	}
+
+	if (kctx->gk5e->keyed_cksum)
+		cksumkey = kctx->cksum;
+	else
+		cksumkey = NULL;
+
+	if (make_checksum(kctx, ptr, 8, buf, crypt_offset,
+					cksumkey, KG_USAGE_SEAL, &md5cksum))
+		return GSS_S_FAILURE;
+
+	if (memcmp(md5cksum.data, ptr + GSS_KRB5_TOK_HDR_LEN,
+						kctx->gk5e->cksumlength))
+		return GSS_S_BAD_SIG;
+
+	/* it got through unscathed.  Make sure the context is unexpired */
+
+	now = get_seconds();
+
+	if (now > kctx->endtime)
+		return GSS_S_CONTEXT_EXPIRED;
+
+	/* do sequencing checks */
+
+	/* Copy the data back to the right position.  XXX: Would probably be
+	 * better to copy and encrypt at the same time. */
+
+	blocksize = crypto_blkcipher_blocksize(kctx->enc);
+	data_start = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) +
+					conflen;
+	orig_start = buf->head[0].iov_base + offset;
+	data_len = (buf->head[0].iov_base + buf->head[0].iov_len) - data_start;
+	memmove(orig_start, data_start, data_len);
+	buf->head[0].iov_len -= (data_start - orig_start);
+	buf->len -= (data_start - orig_start);
+
+	if (gss_krb5_remove_padding(buf, blocksize))
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	return GSS_S_COMPLETE;
+}
+
+/*
+ * We can shift data by up to LOCAL_BUF_LEN bytes in a pass.  If we need
+ * to do more than that, we shift repeatedly.  Kevin Coffman reports
+ * seeing 28 bytes as the value used by Microsoft clients and servers
+ * with AES, so this constant is chosen to allow handling 28 in one pass
+ * without using too much stack space.
+ *
+ * If that proves to a problem perhaps we could use a more clever
+ * algorithm.
+ */
+#define LOCAL_BUF_LEN 32u
+
+static void rotate_buf_a_little(struct xdr_buf *buf, unsigned int shift)
+{
+	char head[LOCAL_BUF_LEN];
+	char tmp[LOCAL_BUF_LEN];
+	unsigned int this_len, i;
+
+	BUG_ON(shift > LOCAL_BUF_LEN);
+
+	read_bytes_from_xdr_buf(buf, 0, head, shift);
+	for (i = 0; i + shift < buf->len; i += LOCAL_BUF_LEN) {
+		this_len = min(LOCAL_BUF_LEN, buf->len - (i + shift));
+		read_bytes_from_xdr_buf(buf, i+shift, tmp, this_len);
+		write_bytes_to_xdr_buf(buf, i, tmp, this_len);
+	}
+	write_bytes_to_xdr_buf(buf, buf->len - shift, head, shift);
+}
+
+static void _rotate_left(struct xdr_buf *buf, unsigned int shift)
+{
+	int shifted = 0;
+	int this_shift;
+
+	shift %= buf->len;
+	while (shifted < shift) {
+		this_shift = min(shift - shifted, LOCAL_BUF_LEN);
+		rotate_buf_a_little(buf, this_shift);
+		shifted += this_shift;
+	}
+}
+
+static void rotate_left(u32 base, struct xdr_buf *buf, unsigned int shift)
+{
+	struct xdr_buf subbuf;
+
+	xdr_buf_subsegment(buf, &subbuf, base, buf->len - base);
+	_rotate_left(&subbuf, shift);
+}
+
+static u32
+gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
+		     struct xdr_buf *buf, struct page **pages)
+{
+	int		blocksize;
+	u8		*ptr, *plainhdr;
+	s32		now;
+	u8		flags = 0x00;
+	__be16		*be16ptr;
+	__be64		*be64ptr;
+	u32		err;
+
+	dprintk("RPC:       %s\n", __func__);
+
+	if (kctx->gk5e->encrypt_v2 == NULL)
+		return GSS_S_FAILURE;
+
+	/* make room for gss token header */
+	if (xdr_extend_head(buf, offset, GSS_KRB5_TOK_HDR_LEN))
+		return GSS_S_FAILURE;
+
+	/* construct gss token header */
+	ptr = plainhdr = buf->head[0].iov_base + offset;
+	*ptr++ = (unsigned char) ((KG2_TOK_WRAP>>8) & 0xff);
+	*ptr++ = (unsigned char) (KG2_TOK_WRAP & 0xff);
+
+	if ((kctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0)
+		flags |= KG2_TOKEN_FLAG_SENTBYACCEPTOR;
+	if ((kctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY) != 0)
+		flags |= KG2_TOKEN_FLAG_ACCEPTORSUBKEY;
+	/* We always do confidentiality in wrap tokens */
+	flags |= KG2_TOKEN_FLAG_SEALED;
+
+	*ptr++ = flags;
+	*ptr++ = 0xff;
+	be16ptr = (__be16 *)ptr;
+
+	blocksize = crypto_blkcipher_blocksize(kctx->acceptor_enc);
+	*be16ptr++ = 0;
+	/* "inner" token header always uses 0 for RRC */
+	*be16ptr++ = 0;
+
+	be64ptr = (__be64 *)be16ptr;
+	spin_lock(&krb5_seq_lock);
+	*be64ptr = cpu_to_be64(kctx->seq_send64++);
+	spin_unlock(&krb5_seq_lock);
+
+	err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, pages);
+	if (err)
+		return err;
+
+	now = get_seconds();
+	return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
+}
+
+static u32
+gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
+{
+	s32		now;
+	u8		*ptr;
+	u8		flags = 0x00;
+	u16		ec, rrc;
+	int		err;
+	u32		headskip, tailskip;
+	u8		decrypted_hdr[GSS_KRB5_TOK_HDR_LEN];
+	unsigned int	movelen;
+
+
+	dprintk("RPC:       %s\n", __func__);
+
+	if (kctx->gk5e->decrypt_v2 == NULL)
+		return GSS_S_FAILURE;
+
+	ptr = buf->head[0].iov_base + offset;
+
+	if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_WRAP)
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	flags = ptr[2];
+	if ((!kctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) ||
+	    (kctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)))
+		return GSS_S_BAD_SIG;
+
+	if ((flags & KG2_TOKEN_FLAG_SEALED) == 0) {
+		dprintk("%s: token missing expected sealed flag\n", __func__);
+		return GSS_S_DEFECTIVE_TOKEN;
+	}
+
+	if (ptr[3] != 0xff)
+		return GSS_S_DEFECTIVE_TOKEN;
+
+	ec = be16_to_cpup((__be16 *)(ptr + 4));
+	rrc = be16_to_cpup((__be16 *)(ptr + 6));
+
+	/*
+	 * NOTE: the sequence number at ptr + 8 is skipped, rpcsec_gss
+	 * doesn't want it checked; see page 6 of rfc 2203.
+	 */
+
+	if (rrc != 0)
+		rotate_left(offset + 16, buf, rrc);
+
+	err = (*kctx->gk5e->decrypt_v2)(kctx, offset, buf,
+					&headskip, &tailskip);
+	if (err)
+		return GSS_S_FAILURE;
+
+	/*
+	 * Retrieve the decrypted gss token header and verify
+	 * it against the original
+	 */
+	err = read_bytes_from_xdr_buf(buf,
+				buf->len - GSS_KRB5_TOK_HDR_LEN - tailskip,
+				decrypted_hdr, GSS_KRB5_TOK_HDR_LEN);
+	if (err) {
+		dprintk("%s: error %u getting decrypted_hdr\n", __func__, err);
+		return GSS_S_FAILURE;
+	}
+	if (memcmp(ptr, decrypted_hdr, 6)
+				|| memcmp(ptr + 8, decrypted_hdr + 8, 8)) {
+		dprintk("%s: token hdr, plaintext hdr mismatch!\n", __func__);
+		return GSS_S_FAILURE;
+	}
+
+	/* do sequencing checks */
+
+	/* it got through unscathed.  Make sure the context is unexpired */
+	now = get_seconds();
+	if (now > kctx->endtime)
+		return GSS_S_CONTEXT_EXPIRED;
+
+	/*
+	 * Move the head data back to the right position in xdr_buf.
+	 * We ignore any "ec" data since it might be in the head or
+	 * the tail, and we really don't need to deal with it.
+	 * Note that buf->head[0].iov_len may indicate the available
+	 * head buffer space rather than that actually occupied.
+	 */
+	movelen = min_t(unsigned int, buf->head[0].iov_len, buf->len);
+	movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip;
+	BUG_ON(offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen >
+							buf->head[0].iov_len);
+	memmove(ptr, ptr + GSS_KRB5_TOK_HDR_LEN + headskip, movelen);
+	buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip;
+	buf->len -= GSS_KRB5_TOK_HDR_LEN + headskip;
+
+	/* Trim off the trailing "extra count" and checksum blob */
+	xdr_buf_trim(buf, ec + GSS_KRB5_TOK_HDR_LEN + tailskip);
+	return GSS_S_COMPLETE;
+}
+
+u32
+gss_wrap_kerberos(struct gss_ctx *gctx, int offset,
+		  struct xdr_buf *buf, struct page **pages)
+{
+	struct krb5_ctx	*kctx = gctx->internal_ctx_id;
+
+	switch (kctx->enctype) {
+	default:
+		BUG();
+	case ENCTYPE_DES_CBC_RAW:
+	case ENCTYPE_DES3_CBC_RAW:
+	case ENCTYPE_ARCFOUR_HMAC:
+		return gss_wrap_kerberos_v1(kctx, offset, buf, pages);
+	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+		return gss_wrap_kerberos_v2(kctx, offset, buf, pages);
+	}
+}
+
+u32
+gss_unwrap_kerberos(struct gss_ctx *gctx, int offset, struct xdr_buf *buf)
+{
+	struct krb5_ctx	*kctx = gctx->internal_ctx_id;
+
+	switch (kctx->enctype) {
+	default:
+		BUG();
+	case ENCTYPE_DES_CBC_RAW:
+	case ENCTYPE_DES3_CBC_RAW:
+	case ENCTYPE_ARCFOUR_HMAC:
+		return gss_unwrap_kerberos_v1(kctx, offset, buf);
+	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+		return gss_unwrap_kerberos_v2(kctx, offset, buf);
+	}
+}
+
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
new file mode 100644
index 000000000..7063d856a
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -0,0 +1,481 @@
+/*
+ *  linux/net/sunrpc/gss_mech_switch.c
+ *
+ *  Copyright (c) 2001 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  J. Bruce Fields   <bfields@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/oid_registry.h>
+#include <linux/sunrpc/msg_prot.h>
+#include <linux/sunrpc/gss_asn1.h>
+#include <linux/sunrpc/auth_gss.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/gss_err.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/gss_api.h>
+#include <linux/sunrpc/clnt.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY        RPCDBG_AUTH
+#endif
+
+static LIST_HEAD(registered_mechs);
+static DEFINE_SPINLOCK(registered_mechs_lock);
+
+static void
+gss_mech_free(struct gss_api_mech *gm)
+{
+	struct pf_desc *pf;
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		pf = &gm->gm_pfs[i];
+		kfree(pf->auth_domain_name);
+		pf->auth_domain_name = NULL;
+	}
+}
+
+static inline char *
+make_auth_domain_name(char *name)
+{
+	static char	*prefix = "gss/";
+	char		*new;
+
+	new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
+	if (new) {
+		strcpy(new, prefix);
+		strcat(new, name);
+	}
+	return new;
+}
+
+static int
+gss_mech_svc_setup(struct gss_api_mech *gm)
+{
+	struct pf_desc *pf;
+	int i, status;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		pf = &gm->gm_pfs[i];
+		pf->auth_domain_name = make_auth_domain_name(pf->name);
+		status = -ENOMEM;
+		if (pf->auth_domain_name == NULL)
+			goto out;
+		status = svcauth_gss_register_pseudoflavor(pf->pseudoflavor,
+							pf->auth_domain_name);
+		if (status)
+			goto out;
+	}
+	return 0;
+out:
+	gss_mech_free(gm);
+	return status;
+}
+
+/**
+ * gss_mech_register - register a GSS mechanism
+ * @gm: GSS mechanism handle
+ *
+ * Returns zero if successful, or a negative errno.
+ */
+int gss_mech_register(struct gss_api_mech *gm)
+{
+	int status;
+
+	status = gss_mech_svc_setup(gm);
+	if (status)
+		return status;
+	spin_lock(&registered_mechs_lock);
+	list_add(&gm->gm_list, &registered_mechs);
+	spin_unlock(&registered_mechs_lock);
+	dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gss_mech_register);
+
+/**
+ * gss_mech_unregister - release a GSS mechanism
+ * @gm: GSS mechanism handle
+ *
+ */
+void gss_mech_unregister(struct gss_api_mech *gm)
+{
+	spin_lock(&registered_mechs_lock);
+	list_del(&gm->gm_list);
+	spin_unlock(&registered_mechs_lock);
+	dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
+	gss_mech_free(gm);
+}
+EXPORT_SYMBOL_GPL(gss_mech_unregister);
+
+struct gss_api_mech *gss_mech_get(struct gss_api_mech *gm)
+{
+	__module_get(gm->gm_owner);
+	return gm;
+}
+EXPORT_SYMBOL(gss_mech_get);
+
+static struct gss_api_mech *
+_gss_mech_get_by_name(const char *name)
+{
+	struct gss_api_mech	*pos, *gm = NULL;
+
+	spin_lock(&registered_mechs_lock);
+	list_for_each_entry(pos, &registered_mechs, gm_list) {
+		if (0 == strcmp(name, pos->gm_name)) {
+			if (try_module_get(pos->gm_owner))
+				gm = pos;
+			break;
+		}
+	}
+	spin_unlock(&registered_mechs_lock);
+	return gm;
+
+}
+
+struct gss_api_mech * gss_mech_get_by_name(const char *name)
+{
+	struct gss_api_mech *gm = NULL;
+
+	gm = _gss_mech_get_by_name(name);
+	if (!gm) {
+		request_module("rpc-auth-gss-%s", name);
+		gm = _gss_mech_get_by_name(name);
+	}
+	return gm;
+}
+
+struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
+{
+	struct gss_api_mech	*pos, *gm = NULL;
+	char buf[32];
+
+	if (sprint_oid(obj->data, obj->len, buf, sizeof(buf)) < 0)
+		return NULL;
+	dprintk("RPC:       %s(%s)\n", __func__, buf);
+	request_module("rpc-auth-gss-%s", buf);
+
+	spin_lock(&registered_mechs_lock);
+	list_for_each_entry(pos, &registered_mechs, gm_list) {
+		if (obj->len == pos->gm_oid.len) {
+			if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
+				if (try_module_get(pos->gm_owner))
+					gm = pos;
+				break;
+			}
+		}
+	}
+	spin_unlock(&registered_mechs_lock);
+	return gm;
+}
+
+static inline int
+mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
+{
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
+			return 1;
+	}
+	return 0;
+}
+
+static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
+{
+	struct gss_api_mech *gm = NULL, *pos;
+
+	spin_lock(&registered_mechs_lock);
+	list_for_each_entry(pos, &registered_mechs, gm_list) {
+		if (!mech_supports_pseudoflavor(pos, pseudoflavor))
+			continue;
+		if (try_module_get(pos->gm_owner))
+			gm = pos;
+		break;
+	}
+	spin_unlock(&registered_mechs_lock);
+	return gm;
+}
+
+struct gss_api_mech *
+gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
+{
+	struct gss_api_mech *gm;
+
+	gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
+
+	if (!gm) {
+		request_module("rpc-auth-gss-%u", pseudoflavor);
+		gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
+	}
+	return gm;
+}
+
+/**
+ * gss_mech_list_pseudoflavors - Discover registered GSS pseudoflavors
+ * @array: array to fill in
+ * @size: size of "array"
+ *
+ * Returns the number of array items filled in, or a negative errno.
+ *
+ * The returned array is not sorted by any policy.  Callers should not
+ * rely on the order of the items in the returned array.
+ */
+int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
+{
+	struct gss_api_mech *pos = NULL;
+	int j, i = 0;
+
+	spin_lock(&registered_mechs_lock);
+	list_for_each_entry(pos, &registered_mechs, gm_list) {
+		for (j = 0; j < pos->gm_pf_num; j++) {
+			if (i >= size) {
+				spin_unlock(&registered_mechs_lock);
+				return -ENOMEM;
+			}
+			array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
+		}
+	}
+	spin_unlock(&registered_mechs_lock);
+	return i;
+}
+
+/**
+ * gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
+ * @gm: GSS mechanism handle
+ * @qop: GSS quality-of-protection value
+ * @service: GSS service value
+ *
+ * Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
+ */
+rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
+					 u32 service)
+{
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].qop == qop &&
+		    gm->gm_pfs[i].service == service) {
+			return gm->gm_pfs[i].pseudoflavor;
+		}
+	}
+	return RPC_AUTH_MAXFLAVOR;
+}
+
+/**
+ * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
+ * @info: a GSS mech OID, quality of protection, and service value
+ *
+ * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
+ * not supported.
+ */
+rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
+{
+	rpc_authflavor_t pseudoflavor;
+	struct gss_api_mech *gm;
+
+	gm = gss_mech_get_by_OID(&info->oid);
+	if (gm == NULL)
+		return RPC_AUTH_MAXFLAVOR;
+
+	pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
+
+	gss_mech_put(gm);
+	return pseudoflavor;
+}
+
+/**
+ * gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
+ * @pseudoflavor: GSS pseudoflavor to match
+ * @info: rpcsec_gss_info structure to fill in
+ *
+ * Returns zero and fills in "info" if pseudoflavor matches a
+ * supported mechanism.  Otherwise a negative errno is returned.
+ */
+int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
+			 struct rpcsec_gss_info *info)
+{
+	struct gss_api_mech *gm;
+	int i;
+
+	gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
+	if (gm == NULL)
+		return -ENOENT;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
+			memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
+			info->oid.len = gm->gm_oid.len;
+			info->qop = gm->gm_pfs[i].qop;
+			info->service = gm->gm_pfs[i].service;
+			gss_mech_put(gm);
+			return 0;
+		}
+	}
+
+	gss_mech_put(gm);
+	return -ENOENT;
+}
+
+u32
+gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
+{
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
+			return gm->gm_pfs[i].service;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(gss_pseudoflavor_to_service);
+
+char *
+gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
+{
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].service == service)
+			return gm->gm_pfs[i].auth_domain_name;
+	}
+	return NULL;
+}
+
+void
+gss_mech_put(struct gss_api_mech * gm)
+{
+	if (gm)
+		module_put(gm->gm_owner);
+}
+EXPORT_SYMBOL(gss_mech_put);
+
+/* The mech could probably be determined from the token instead, but it's just
+ * as easy for now to pass it in. */
+int
+gss_import_sec_context(const void *input_token, size_t bufsize,
+		       struct gss_api_mech	*mech,
+		       struct gss_ctx		**ctx_id,
+		       time_t			*endtime,
+		       gfp_t gfp_mask)
+{
+	if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
+		return -ENOMEM;
+	(*ctx_id)->mech_type = gss_mech_get(mech);
+
+	return mech->gm_ops->gss_import_sec_context(input_token, bufsize,
+						*ctx_id, endtime, gfp_mask);
+}
+
+/* gss_get_mic: compute a mic over message and return mic_token. */
+
+u32
+gss_get_mic(struct gss_ctx	*context_handle,
+	    struct xdr_buf	*message,
+	    struct xdr_netobj	*mic_token)
+{
+	 return context_handle->mech_type->gm_ops
+		->gss_get_mic(context_handle,
+			      message,
+			      mic_token);
+}
+
+/* gss_verify_mic: check whether the provided mic_token verifies message. */
+
+u32
+gss_verify_mic(struct gss_ctx		*context_handle,
+	       struct xdr_buf		*message,
+	       struct xdr_netobj	*mic_token)
+{
+	return context_handle->mech_type->gm_ops
+		->gss_verify_mic(context_handle,
+				 message,
+				 mic_token);
+}
+
+/*
+ * This function is called from both the client and server code.
+ * Each makes guarantees about how much "slack" space is available
+ * for the underlying function in "buf"'s head and tail while
+ * performing the wrap.
+ *
+ * The client and server code allocate RPC_MAX_AUTH_SIZE extra
+ * space in both the head and tail which is available for use by
+ * the wrap function.
+ *
+ * Underlying functions should verify they do not use more than
+ * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
+ * when performing the wrap.
+ */
+u32
+gss_wrap(struct gss_ctx	*ctx_id,
+	 int		offset,
+	 struct xdr_buf	*buf,
+	 struct page	**inpages)
+{
+	return ctx_id->mech_type->gm_ops
+		->gss_wrap(ctx_id, offset, buf, inpages);
+}
+
+u32
+gss_unwrap(struct gss_ctx	*ctx_id,
+	   int			offset,
+	   struct xdr_buf	*buf)
+{
+	return ctx_id->mech_type->gm_ops
+		->gss_unwrap(ctx_id, offset, buf);
+}
+
+
+/* gss_delete_sec_context: free all resources associated with context_handle.
+ * Note this differs from the RFC 2744-specified prototype in that we don't
+ * bother returning an output token, since it would never be used anyway. */
+
+u32
+gss_delete_sec_context(struct gss_ctx	**context_handle)
+{
+	dprintk("RPC:       gss_delete_sec_context deleting %p\n",
+			*context_handle);
+
+	if (!*context_handle)
+		return GSS_S_NO_CONTEXT;
+	if ((*context_handle)->internal_ctx_id)
+		(*context_handle)->mech_type->gm_ops
+			->gss_delete_sec_context((*context_handle)
+							->internal_ctx_id);
+	gss_mech_put((*context_handle)->mech_type);
+	kfree(*context_handle);
+	*context_handle=NULL;
+	return GSS_S_COMPLETE;
+}
diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.c b/net/sunrpc/auth_gss/gss_rpc_upcall.c
new file mode 100644
index 000000000..59eeed43e
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -0,0 +1,384 @@
+/*
+ *  linux/net/sunrpc/gss_rpc_upcall.c
+ *
+ *  Copyright (C) 2012 Simo Sorce <simo@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/types.h>
+#include <linux/un.h>
+
+#include <linux/sunrpc/svcauth.h>
+#include "gss_rpc_upcall.h"
+
+#define GSSPROXY_SOCK_PATHNAME	"/var/run/gssproxy.sock"
+
+#define GSSPROXY_PROGRAM	(400112u)
+#define GSSPROXY_VERS_1		(1u)
+
+/*
+ * Encoding/Decoding functions
+ */
+
+enum {
+	GSSX_NULL = 0,	/* Unused */
+        GSSX_INDICATE_MECHS = 1,
+        GSSX_GET_CALL_CONTEXT = 2,
+        GSSX_IMPORT_AND_CANON_NAME = 3,
+        GSSX_EXPORT_CRED = 4,
+        GSSX_IMPORT_CRED = 5,
+        GSSX_ACQUIRE_CRED = 6,
+        GSSX_STORE_CRED = 7,
+        GSSX_INIT_SEC_CONTEXT = 8,
+        GSSX_ACCEPT_SEC_CONTEXT = 9,
+        GSSX_RELEASE_HANDLE = 10,
+        GSSX_GET_MIC = 11,
+        GSSX_VERIFY = 12,
+        GSSX_WRAP = 13,
+        GSSX_UNWRAP = 14,
+        GSSX_WRAP_SIZE_LIMIT = 15,
+};
+
+#define PROC(proc, name)				\
+[GSSX_##proc] = {					\
+	.p_proc   = GSSX_##proc,			\
+	.p_encode = (kxdreproc_t)gssx_enc_##name,	\
+	.p_decode = (kxdrdproc_t)gssx_dec_##name,	\
+	.p_arglen = GSSX_ARG_##name##_sz,		\
+	.p_replen = GSSX_RES_##name##_sz, 		\
+	.p_statidx = GSSX_##proc,			\
+	.p_name   = #proc,				\
+}
+
+static struct rpc_procinfo gssp_procedures[] = {
+	PROC(INDICATE_MECHS, indicate_mechs),
+        PROC(GET_CALL_CONTEXT, get_call_context),
+        PROC(IMPORT_AND_CANON_NAME, import_and_canon_name),
+        PROC(EXPORT_CRED, export_cred),
+        PROC(IMPORT_CRED, import_cred),
+        PROC(ACQUIRE_CRED, acquire_cred),
+        PROC(STORE_CRED, store_cred),
+        PROC(INIT_SEC_CONTEXT, init_sec_context),
+        PROC(ACCEPT_SEC_CONTEXT, accept_sec_context),
+        PROC(RELEASE_HANDLE, release_handle),
+        PROC(GET_MIC, get_mic),
+        PROC(VERIFY, verify),
+        PROC(WRAP, wrap),
+        PROC(UNWRAP, unwrap),
+        PROC(WRAP_SIZE_LIMIT, wrap_size_limit),
+};
+
+
+
+/*
+ * Common transport functions
+ */
+
+static const struct rpc_program gssp_program;
+
+static int gssp_rpc_create(struct net *net, struct rpc_clnt **_clnt)
+{
+	static const struct sockaddr_un gssp_localaddr = {
+		.sun_family		= AF_LOCAL,
+		.sun_path		= GSSPROXY_SOCK_PATHNAME,
+	};
+	struct rpc_create_args args = {
+		.net		= net,
+		.protocol	= XPRT_TRANSPORT_LOCAL,
+		.address	= (struct sockaddr *)&gssp_localaddr,
+		.addrsize	= sizeof(gssp_localaddr),
+		.servername	= "localhost",
+		.program	= &gssp_program,
+		.version	= GSSPROXY_VERS_1,
+		.authflavor	= RPC_AUTH_NULL,
+		/*
+		 * Note we want connection to be done in the caller's
+		 * filesystem namespace.  We therefore turn off the idle
+		 * timeout, which would result in reconnections being
+		 * done without the correct namespace:
+		 */
+		.flags		= RPC_CLNT_CREATE_NOPING |
+				  RPC_CLNT_CREATE_NO_IDLE_TIMEOUT
+	};
+	struct rpc_clnt *clnt;
+	int result = 0;
+
+	clnt = rpc_create(&args);
+	if (IS_ERR(clnt)) {
+		dprintk("RPC:       failed to create AF_LOCAL gssproxy "
+				"client (errno %ld).\n", PTR_ERR(clnt));
+		result = PTR_ERR(clnt);
+		*_clnt = NULL;
+		goto out;
+	}
+
+	dprintk("RPC:       created new gssp local client (gssp_local_clnt: "
+			"%p)\n", clnt);
+	*_clnt = clnt;
+
+out:
+	return result;
+}
+
+void init_gssp_clnt(struct sunrpc_net *sn)
+{
+	mutex_init(&sn->gssp_lock);
+	sn->gssp_clnt = NULL;
+}
+
+int set_gssp_clnt(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct rpc_clnt *clnt;
+	int ret;
+
+	mutex_lock(&sn->gssp_lock);
+	ret = gssp_rpc_create(net, &clnt);
+	if (!ret) {
+		if (sn->gssp_clnt)
+			rpc_shutdown_client(sn->gssp_clnt);
+		sn->gssp_clnt = clnt;
+	}
+	mutex_unlock(&sn->gssp_lock);
+	return ret;
+}
+
+void clear_gssp_clnt(struct sunrpc_net *sn)
+{
+	mutex_lock(&sn->gssp_lock);
+	if (sn->gssp_clnt) {
+		rpc_shutdown_client(sn->gssp_clnt);
+		sn->gssp_clnt = NULL;
+	}
+	mutex_unlock(&sn->gssp_lock);
+}
+
+static struct rpc_clnt *get_gssp_clnt(struct sunrpc_net *sn)
+{
+	struct rpc_clnt *clnt;
+
+	mutex_lock(&sn->gssp_lock);
+	clnt = sn->gssp_clnt;
+	if (clnt)
+		atomic_inc(&clnt->cl_count);
+	mutex_unlock(&sn->gssp_lock);
+	return clnt;
+}
+
+static int gssp_call(struct net *net, struct rpc_message *msg)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct rpc_clnt *clnt;
+	int status;
+
+	clnt = get_gssp_clnt(sn);
+	if (!clnt)
+		return -EIO;
+	status = rpc_call_sync(clnt, msg, 0);
+	if (status < 0) {
+		dprintk("gssp: rpc_call returned error %d\n", -status);
+		switch (status) {
+		case -EPROTONOSUPPORT:
+			status = -EINVAL;
+			break;
+		case -ECONNREFUSED:
+		case -ETIMEDOUT:
+		case -ENOTCONN:
+			status = -EAGAIN;
+			break;
+		case -ERESTARTSYS:
+			if (signalled ())
+				status = -EINTR;
+			break;
+		default:
+			break;
+		}
+	}
+	rpc_release_client(clnt);
+	return status;
+}
+
+static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg)
+{
+	int i;
+
+	for (i = 0; i < arg->npages && arg->pages[i]; i++)
+		__free_page(arg->pages[i]);
+
+	kfree(arg->pages);
+}
+
+static int gssp_alloc_receive_pages(struct gssx_arg_accept_sec_context *arg)
+{
+	arg->npages = DIV_ROUND_UP(NGROUPS_MAX * 4, PAGE_SIZE);
+	arg->pages = kzalloc(arg->npages * sizeof(struct page *), GFP_KERNEL);
+	/*
+	 * XXX: actual pages are allocated by xdr layer in
+	 * xdr_partial_copy_from_skb.
+	 */
+	if (!arg->pages)
+		return -ENOMEM;
+	return 0;
+}
+
+/*
+ * Public functions
+ */
+
+/* numbers somewhat arbitrary but large enough for current needs */
+#define GSSX_MAX_OUT_HANDLE	128
+#define GSSX_MAX_SRC_PRINC	256
+#define GSSX_KMEMBUF (GSSX_max_output_handle_sz + \
+			GSSX_max_oid_sz + \
+			GSSX_max_princ_sz + \
+			sizeof(struct svc_cred))
+
+int gssp_accept_sec_context_upcall(struct net *net,
+				struct gssp_upcall_data *data)
+{
+	struct gssx_ctx ctxh = {
+		.state = data->in_handle
+	};
+	struct gssx_arg_accept_sec_context arg = {
+		.input_token = data->in_token,
+	};
+	struct gssx_ctx rctxh = {
+		/*
+		 * pass in the max length we expect for each of these
+		 * buffers but let the xdr code kmalloc them:
+		 */
+		.exported_context_token.len = GSSX_max_output_handle_sz,
+		.mech.len = GSS_OID_MAX_LEN,
+		.src_name.display_name.len = GSSX_max_princ_sz
+	};
+	struct gssx_res_accept_sec_context res = {
+		.context_handle = &rctxh,
+		.output_token = &data->out_token
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &gssp_procedures[GSSX_ACCEPT_SEC_CONTEXT],
+		.rpc_argp = &arg,
+		.rpc_resp = &res,
+		.rpc_cred = NULL, /* FIXME ? */
+	};
+	struct xdr_netobj client_name = { 0 , NULL };
+	int ret;
+
+	if (data->in_handle.len != 0)
+		arg.context_handle = &ctxh;
+	res.output_token->len = GSSX_max_output_token_sz;
+
+	ret = gssp_alloc_receive_pages(&arg);
+	if (ret)
+		return ret;
+
+	/* use nfs/ for targ_name ? */
+
+	ret = gssp_call(net, &msg);
+
+	gssp_free_receive_pages(&arg);
+
+	/* we need to fetch all data even in case of error so
+	 * that we can free special strctures is they have been allocated */
+	data->major_status = res.status.major_status;
+	data->minor_status = res.status.minor_status;
+	if (res.context_handle) {
+		data->out_handle = rctxh.exported_context_token;
+		data->mech_oid.len = rctxh.mech.len;
+		if (rctxh.mech.data)
+			memcpy(data->mech_oid.data, rctxh.mech.data,
+						data->mech_oid.len);
+		client_name = rctxh.src_name.display_name;
+	}
+
+	if (res.options.count == 1) {
+		gssx_buffer *value = &res.options.data[0].value;
+		/* Currently we only decode CREDS_VALUE, if we add
+		 * anything else we'll have to loop and match on the
+		 * option name */
+		if (value->len == 1) {
+			/* steal group info from struct svc_cred */
+			data->creds = *(struct svc_cred *)value->data;
+			data->found_creds = 1;
+		}
+		/* whether we use it or not, free data */
+		kfree(value->data);
+	}
+
+	if (res.options.count != 0) {
+		kfree(res.options.data);
+	}
+
+	/* convert to GSS_NT_HOSTBASED_SERVICE form and set into creds */
+	if (data->found_creds && client_name.data != NULL) {
+		char *c;
+
+		data->creds.cr_principal = kstrndup(client_name.data,
+						client_name.len, GFP_KERNEL);
+		if (data->creds.cr_principal) {
+			/* terminate and remove realm part */
+			c = strchr(data->creds.cr_principal, '@');
+			if (c) {
+				*c = '\0';
+
+				/* change service-hostname delimiter */
+				c = strchr(data->creds.cr_principal, '/');
+				if (c) *c = '@';
+			}
+			if (!c) {
+				/* not a service principal */
+				kfree(data->creds.cr_principal);
+				data->creds.cr_principal = NULL;
+			}
+		}
+	}
+	kfree(client_name.data);
+
+	return ret;
+}
+
+void gssp_free_upcall_data(struct gssp_upcall_data *data)
+{
+	kfree(data->in_handle.data);
+	kfree(data->out_handle.data);
+	kfree(data->out_token.data);
+	free_svc_cred(&data->creds);
+}
+
+/*
+ * Initialization stuff
+ */
+
+static const struct rpc_version gssp_version1 = {
+	.number		= GSSPROXY_VERS_1,
+	.nrprocs	= ARRAY_SIZE(gssp_procedures),
+	.procs		= gssp_procedures,
+};
+
+static const struct rpc_version *gssp_version[] = {
+	NULL,
+	&gssp_version1,
+};
+
+static struct rpc_stat gssp_stats;
+
+static const struct rpc_program gssp_program = {
+	.name		= "gssproxy",
+	.number		= GSSPROXY_PROGRAM,
+	.nrvers		= ARRAY_SIZE(gssp_version),
+	.version	= gssp_version,
+	.stats		= &gssp_stats,
+};
diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.h b/net/sunrpc/auth_gss/gss_rpc_upcall.h
new file mode 100644
index 000000000..1e542aded
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.h
@@ -0,0 +1,48 @@
+/*
+ *  linux/net/sunrpc/gss_rpc_upcall.h
+ *
+ *  Copyright (C) 2012 Simo Sorce <simo@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _GSS_RPC_UPCALL_H
+#define _GSS_RPC_UPCALL_H
+
+#include <linux/sunrpc/gss_api.h>
+#include <linux/sunrpc/auth_gss.h>
+#include "gss_rpc_xdr.h"
+#include "../netns.h"
+
+struct gssp_upcall_data {
+	struct xdr_netobj in_handle;
+	struct gssp_in_token in_token;
+	struct xdr_netobj out_handle;
+	struct xdr_netobj out_token;
+	struct rpcsec_gss_oid mech_oid;
+	struct svc_cred creds;
+	int found_creds;
+	int major_status;
+	int minor_status;
+};
+
+int gssp_accept_sec_context_upcall(struct net *net,
+				struct gssp_upcall_data *data);
+void gssp_free_upcall_data(struct gssp_upcall_data *data);
+
+void init_gssp_clnt(struct sunrpc_net *);
+int set_gssp_clnt(struct net *);
+void clear_gssp_clnt(struct sunrpc_net *);
+#endif /* _GSS_RPC_UPCALL_H */
diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c
new file mode 100644
index 000000000..eeeba5ade
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c
@@ -0,0 +1,848 @@
+/*
+ * GSS Proxy upcall module
+ *
+ *  Copyright (C) 2012 Simo Sorce <simo@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/sunrpc/svcauth.h>
+#include "gss_rpc_xdr.h"
+
+static int gssx_enc_bool(struct xdr_stream *xdr, int v)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	*p = v ? xdr_one : xdr_zero;
+	return 0;
+}
+
+static int gssx_dec_bool(struct xdr_stream *xdr, u32 *v)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	*v = be32_to_cpu(*p);
+	return 0;
+}
+
+static int gssx_enc_buffer(struct xdr_stream *xdr,
+			   gssx_buffer *buf)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, sizeof(u32) + buf->len);
+	if (!p)
+		return -ENOSPC;
+	xdr_encode_opaque(p, buf->data, buf->len);
+	return 0;
+}
+
+static int gssx_enc_in_token(struct xdr_stream *xdr,
+			     struct gssp_in_token *in)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return -ENOSPC;
+	*p = cpu_to_be32(in->page_len);
+
+	/* all we need to do is to write pages */
+	xdr_write_pages(xdr, in->pages, in->page_base, in->page_len);
+
+	return 0;
+}
+
+
+static int gssx_dec_buffer(struct xdr_stream *xdr,
+			   gssx_buffer *buf)
+{
+	u32 length;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+
+	length = be32_to_cpup(p);
+	p = xdr_inline_decode(xdr, length);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+
+	if (buf->len == 0) {
+		/* we intentionally are not interested in this buffer */
+		return 0;
+	}
+	if (length > buf->len)
+		return -ENOSPC;
+
+	if (!buf->data) {
+		buf->data = kmemdup(p, length, GFP_KERNEL);
+		if (!buf->data)
+			return -ENOMEM;
+	} else {
+		memcpy(buf->data, p, length);
+	}
+	buf->len = length;
+	return 0;
+}
+
+static int gssx_enc_option(struct xdr_stream *xdr,
+			   struct gssx_option *opt)
+{
+	int err;
+
+	err = gssx_enc_buffer(xdr, &opt->option);
+	if (err)
+		return err;
+	err = gssx_enc_buffer(xdr, &opt->value);
+	return err;
+}
+
+static int gssx_dec_option(struct xdr_stream *xdr,
+			   struct gssx_option *opt)
+{
+	int err;
+
+	err = gssx_dec_buffer(xdr, &opt->option);
+	if (err)
+		return err;
+	err = gssx_dec_buffer(xdr, &opt->value);
+	return err;
+}
+
+static int dummy_enc_opt_array(struct xdr_stream *xdr,
+				struct gssx_option_array *oa)
+{
+	__be32 *p;
+
+	if (oa->count != 0)
+		return -EINVAL;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return -ENOSPC;
+	*p = 0;
+
+	return 0;
+}
+
+static int dummy_dec_opt_array(struct xdr_stream *xdr,
+				struct gssx_option_array *oa)
+{
+	struct gssx_option dummy;
+	u32 count, i;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	count = be32_to_cpup(p++);
+	memset(&dummy, 0, sizeof(dummy));
+	for (i = 0; i < count; i++) {
+		gssx_dec_option(xdr, &dummy);
+	}
+
+	oa->count = 0;
+	oa->data = NULL;
+	return 0;
+}
+
+static int get_host_u32(struct xdr_stream *xdr, u32 *res)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (!p)
+		return -EINVAL;
+	/* Contents of linux creds are all host-endian: */
+	memcpy(res, p, sizeof(u32));
+	return 0;
+}
+
+static int gssx_dec_linux_creds(struct xdr_stream *xdr,
+				struct svc_cred *creds)
+{
+	u32 length;
+	__be32 *p;
+	u32 tmp;
+	u32 N;
+	int i, err;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+
+	length = be32_to_cpup(p);
+
+	if (length > (3 + NGROUPS_MAX) * sizeof(u32))
+		return -ENOSPC;
+
+	/* uid */
+	err = get_host_u32(xdr, &tmp);
+	if (err)
+		return err;
+	creds->cr_uid = make_kuid(&init_user_ns, tmp);
+
+	/* gid */
+	err = get_host_u32(xdr, &tmp);
+	if (err)
+		return err;
+	creds->cr_gid = make_kgid(&init_user_ns, tmp);
+
+	/* number of additional gid's */
+	err = get_host_u32(xdr, &tmp);
+	if (err)
+		return err;
+	N = tmp;
+	if ((3 + N) * sizeof(u32) != length)
+		return -EINVAL;
+	creds->cr_group_info = groups_alloc(N);
+	if (creds->cr_group_info == NULL)
+		return -ENOMEM;
+
+	/* gid's */
+	for (i = 0; i < N; i++) {
+		kgid_t kgid;
+		err = get_host_u32(xdr, &tmp);
+		if (err)
+			goto out_free_groups;
+		err = -EINVAL;
+		kgid = make_kgid(&init_user_ns, tmp);
+		if (!gid_valid(kgid))
+			goto out_free_groups;
+		GROUP_AT(creds->cr_group_info, i) = kgid;
+	}
+
+	return 0;
+out_free_groups:
+	groups_free(creds->cr_group_info);
+	return err;
+}
+
+static int gssx_dec_option_array(struct xdr_stream *xdr,
+				 struct gssx_option_array *oa)
+{
+	struct svc_cred *creds;
+	u32 count, i;
+	__be32 *p;
+	int err;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	count = be32_to_cpup(p++);
+	if (!count)
+		return 0;
+
+	/* we recognize only 1 currently: CREDS_VALUE */
+	oa->count = 1;
+
+	oa->data = kmalloc(sizeof(struct gssx_option), GFP_KERNEL);
+	if (!oa->data)
+		return -ENOMEM;
+
+	creds = kmalloc(sizeof(struct svc_cred), GFP_KERNEL);
+	if (!creds) {
+		kfree(oa->data);
+		return -ENOMEM;
+	}
+
+	oa->data[0].option.data = CREDS_VALUE;
+	oa->data[0].option.len = sizeof(CREDS_VALUE);
+	oa->data[0].value.data = (void *)creds;
+	oa->data[0].value.len = 0;
+
+	for (i = 0; i < count; i++) {
+		gssx_buffer dummy = { 0, NULL };
+		u32 length;
+
+		/* option buffer */
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(p == NULL))
+			return -ENOSPC;
+
+		length = be32_to_cpup(p);
+		p = xdr_inline_decode(xdr, length);
+		if (unlikely(p == NULL))
+			return -ENOSPC;
+
+		if (length == sizeof(CREDS_VALUE) &&
+		    memcmp(p, CREDS_VALUE, sizeof(CREDS_VALUE)) == 0) {
+			/* We have creds here. parse them */
+			err = gssx_dec_linux_creds(xdr, creds);
+			if (err)
+				return err;
+			oa->data[0].value.len = 1; /* presence */
+		} else {
+			/* consume uninteresting buffer */
+			err = gssx_dec_buffer(xdr, &dummy);
+			if (err)
+				return err;
+		}
+	}
+	return 0;
+}
+
+static int gssx_dec_status(struct xdr_stream *xdr,
+			   struct gssx_status *status)
+{
+	__be32 *p;
+	int err;
+
+	/* status->major_status */
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	p = xdr_decode_hyper(p, &status->major_status);
+
+	/* status->mech */
+	err = gssx_dec_buffer(xdr, &status->mech);
+	if (err)
+		return err;
+
+	/* status->minor_status */
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	p = xdr_decode_hyper(p, &status->minor_status);
+
+	/* status->major_status_string */
+	err = gssx_dec_buffer(xdr, &status->major_status_string);
+	if (err)
+		return err;
+
+	/* status->minor_status_string */
+	err = gssx_dec_buffer(xdr, &status->minor_status_string);
+	if (err)
+		return err;
+
+	/* status->server_ctx */
+	err = gssx_dec_buffer(xdr, &status->server_ctx);
+	if (err)
+		return err;
+
+	/* we assume we have no options for now, so simply consume them */
+	/* status->options */
+	err = dummy_dec_opt_array(xdr, &status->options);
+
+	return err;
+}
+
+static int gssx_enc_call_ctx(struct xdr_stream *xdr,
+			     struct gssx_call_ctx *ctx)
+{
+	struct gssx_option opt;
+	__be32 *p;
+	int err;
+
+	/* ctx->locale */
+	err = gssx_enc_buffer(xdr, &ctx->locale);
+	if (err)
+		return err;
+
+	/* ctx->server_ctx */
+	err = gssx_enc_buffer(xdr, &ctx->server_ctx);
+	if (err)
+		return err;
+
+	/* we always want to ask for lucid contexts */
+	/* ctx->options */
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(2);
+
+	/* we want a lucid_v1 context */
+	opt.option.data = LUCID_OPTION;
+	opt.option.len = sizeof(LUCID_OPTION);
+	opt.value.data = LUCID_VALUE;
+	opt.value.len = sizeof(LUCID_VALUE);
+	err = gssx_enc_option(xdr, &opt);
+
+	/* ..and user creds */
+	opt.option.data = CREDS_OPTION;
+	opt.option.len = sizeof(CREDS_OPTION);
+	opt.value.data = CREDS_VALUE;
+	opt.value.len = sizeof(CREDS_VALUE);
+	err = gssx_enc_option(xdr, &opt);
+
+	return err;
+}
+
+static int gssx_dec_name_attr(struct xdr_stream *xdr,
+			     struct gssx_name_attr *attr)
+{
+	int err;
+
+	/* attr->attr */
+	err = gssx_dec_buffer(xdr, &attr->attr);
+	if (err)
+		return err;
+
+	/* attr->value */
+	err = gssx_dec_buffer(xdr, &attr->value);
+	if (err)
+		return err;
+
+	/* attr->extensions */
+	err = dummy_dec_opt_array(xdr, &attr->extensions);
+
+	return err;
+}
+
+static int dummy_enc_nameattr_array(struct xdr_stream *xdr,
+				    struct gssx_name_attr_array *naa)
+{
+	__be32 *p;
+
+	if (naa->count != 0)
+		return -EINVAL;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return -ENOSPC;
+	*p = 0;
+
+	return 0;
+}
+
+static int dummy_dec_nameattr_array(struct xdr_stream *xdr,
+				    struct gssx_name_attr_array *naa)
+{
+	struct gssx_name_attr dummy = { .attr = {.len = 0} };
+	u32 count, i;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	count = be32_to_cpup(p++);
+	for (i = 0; i < count; i++) {
+		gssx_dec_name_attr(xdr, &dummy);
+	}
+
+	naa->count = 0;
+	naa->data = NULL;
+	return 0;
+}
+
+static struct xdr_netobj zero_netobj = {};
+
+static struct gssx_name_attr_array zero_name_attr_array = {};
+
+static struct gssx_option_array zero_option_array = {};
+
+static int gssx_enc_name(struct xdr_stream *xdr,
+			 struct gssx_name *name)
+{
+	int err;
+
+	/* name->display_name */
+	err = gssx_enc_buffer(xdr, &name->display_name);
+	if (err)
+		return err;
+
+	/* name->name_type */
+	err = gssx_enc_buffer(xdr, &zero_netobj);
+	if (err)
+		return err;
+
+	/* name->exported_name */
+	err = gssx_enc_buffer(xdr, &zero_netobj);
+	if (err)
+		return err;
+
+	/* name->exported_composite_name */
+	err = gssx_enc_buffer(xdr, &zero_netobj);
+	if (err)
+		return err;
+
+	/* leave name_attributes empty for now, will add once we have any
+	 * to pass up at all */
+	/* name->name_attributes */
+	err = dummy_enc_nameattr_array(xdr, &zero_name_attr_array);
+	if (err)
+		return err;
+
+	/* leave options empty for now, will add once we have any options
+	 * to pass up at all */
+	/* name->extensions */
+	err = dummy_enc_opt_array(xdr, &zero_option_array);
+
+	return err;
+}
+
+
+static int gssx_dec_name(struct xdr_stream *xdr,
+			 struct gssx_name *name)
+{
+	struct xdr_netobj dummy_netobj = { .len = 0 };
+	struct gssx_name_attr_array dummy_name_attr_array = { .count = 0 };
+	struct gssx_option_array dummy_option_array = { .count = 0 };
+	int err;
+
+	/* name->display_name */
+	err = gssx_dec_buffer(xdr, &name->display_name);
+	if (err)
+		return err;
+
+	/* name->name_type */
+	err = gssx_dec_buffer(xdr, &dummy_netobj);
+	if (err)
+		return err;
+
+	/* name->exported_name */
+	err = gssx_dec_buffer(xdr, &dummy_netobj);
+	if (err)
+		return err;
+
+	/* name->exported_composite_name */
+	err = gssx_dec_buffer(xdr, &dummy_netobj);
+	if (err)
+		return err;
+
+	/* we assume we have no attributes for now, so simply consume them */
+	/* name->name_attributes */
+	err = dummy_dec_nameattr_array(xdr, &dummy_name_attr_array);
+	if (err)
+		return err;
+
+	/* we assume we have no options for now, so simply consume them */
+	/* name->extensions */
+	err = dummy_dec_opt_array(xdr, &dummy_option_array);
+
+	return err;
+}
+
+static int dummy_enc_credel_array(struct xdr_stream *xdr,
+				  struct gssx_cred_element_array *cea)
+{
+	__be32 *p;
+
+	if (cea->count != 0)
+		return -EINVAL;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return -ENOSPC;
+	*p = 0;
+
+	return 0;
+}
+
+static int gssx_enc_cred(struct xdr_stream *xdr,
+			 struct gssx_cred *cred)
+{
+	int err;
+
+	/* cred->desired_name */
+	err = gssx_enc_name(xdr, &cred->desired_name);
+	if (err)
+		return err;
+
+	/* cred->elements */
+	err = dummy_enc_credel_array(xdr, &cred->elements);
+	if (err)
+		return err;
+
+	/* cred->cred_handle_reference */
+	err = gssx_enc_buffer(xdr, &cred->cred_handle_reference);
+	if (err)
+		return err;
+
+	/* cred->needs_release */
+	err = gssx_enc_bool(xdr, cred->needs_release);
+
+	return err;
+}
+
+static int gssx_enc_ctx(struct xdr_stream *xdr,
+			struct gssx_ctx *ctx)
+{
+	__be32 *p;
+	int err;
+
+	/* ctx->exported_context_token */
+	err = gssx_enc_buffer(xdr, &ctx->exported_context_token);
+	if (err)
+		return err;
+
+	/* ctx->state */
+	err = gssx_enc_buffer(xdr, &ctx->state);
+	if (err)
+		return err;
+
+	/* ctx->need_release */
+	err = gssx_enc_bool(xdr, ctx->need_release);
+	if (err)
+		return err;
+
+	/* ctx->mech */
+	err = gssx_enc_buffer(xdr, &ctx->mech);
+	if (err)
+		return err;
+
+	/* ctx->src_name */
+	err = gssx_enc_name(xdr, &ctx->src_name);
+	if (err)
+		return err;
+
+	/* ctx->targ_name */
+	err = gssx_enc_name(xdr, &ctx->targ_name);
+	if (err)
+		return err;
+
+	/* ctx->lifetime */
+	p = xdr_reserve_space(xdr, 8+8);
+	if (!p)
+		return -ENOSPC;
+	p = xdr_encode_hyper(p, ctx->lifetime);
+
+	/* ctx->ctx_flags */
+	p = xdr_encode_hyper(p, ctx->ctx_flags);
+
+	/* ctx->locally_initiated */
+	err = gssx_enc_bool(xdr, ctx->locally_initiated);
+	if (err)
+		return err;
+
+	/* ctx->open */
+	err = gssx_enc_bool(xdr, ctx->open);
+	if (err)
+		return err;
+
+	/* leave options empty for now, will add once we have any options
+	 * to pass up at all */
+	/* ctx->options */
+	err = dummy_enc_opt_array(xdr, &ctx->options);
+
+	return err;
+}
+
+static int gssx_dec_ctx(struct xdr_stream *xdr,
+			struct gssx_ctx *ctx)
+{
+	__be32 *p;
+	int err;
+
+	/* ctx->exported_context_token */
+	err = gssx_dec_buffer(xdr, &ctx->exported_context_token);
+	if (err)
+		return err;
+
+	/* ctx->state */
+	err = gssx_dec_buffer(xdr, &ctx->state);
+	if (err)
+		return err;
+
+	/* ctx->need_release */
+	err = gssx_dec_bool(xdr, &ctx->need_release);
+	if (err)
+		return err;
+
+	/* ctx->mech */
+	err = gssx_dec_buffer(xdr, &ctx->mech);
+	if (err)
+		return err;
+
+	/* ctx->src_name */
+	err = gssx_dec_name(xdr, &ctx->src_name);
+	if (err)
+		return err;
+
+	/* ctx->targ_name */
+	err = gssx_dec_name(xdr, &ctx->targ_name);
+	if (err)
+		return err;
+
+	/* ctx->lifetime */
+	p = xdr_inline_decode(xdr, 8+8);
+	if (unlikely(p == NULL))
+		return -ENOSPC;
+	p = xdr_decode_hyper(p, &ctx->lifetime);
+
+	/* ctx->ctx_flags */
+	p = xdr_decode_hyper(p, &ctx->ctx_flags);
+
+	/* ctx->locally_initiated */
+	err = gssx_dec_bool(xdr, &ctx->locally_initiated);
+	if (err)
+		return err;
+
+	/* ctx->open */
+	err = gssx_dec_bool(xdr, &ctx->open);
+	if (err)
+		return err;
+
+	/* we assume we have no options for now, so simply consume them */
+	/* ctx->options */
+	err = dummy_dec_opt_array(xdr, &ctx->options);
+
+	return err;
+}
+
+static int gssx_enc_cb(struct xdr_stream *xdr, struct gssx_cb *cb)
+{
+	__be32 *p;
+	int err;
+
+	/* cb->initiator_addrtype */
+	p = xdr_reserve_space(xdr, 8);
+	if (!p)
+		return -ENOSPC;
+	p = xdr_encode_hyper(p, cb->initiator_addrtype);
+
+	/* cb->initiator_address */
+	err = gssx_enc_buffer(xdr, &cb->initiator_address);
+	if (err)
+		return err;
+
+	/* cb->acceptor_addrtype */
+	p = xdr_reserve_space(xdr, 8);
+	if (!p)
+		return -ENOSPC;
+	p = xdr_encode_hyper(p, cb->acceptor_addrtype);
+
+	/* cb->acceptor_address */
+	err = gssx_enc_buffer(xdr, &cb->acceptor_address);
+	if (err)
+		return err;
+
+	/* cb->application_data */
+	err = gssx_enc_buffer(xdr, &cb->application_data);
+
+	return err;
+}
+
+void gssx_enc_accept_sec_context(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 struct gssx_arg_accept_sec_context *arg)
+{
+	int err;
+
+	err = gssx_enc_call_ctx(xdr, &arg->call_ctx);
+	if (err)
+		goto done;
+
+	/* arg->context_handle */
+	if (arg->context_handle)
+		err = gssx_enc_ctx(xdr, arg->context_handle);
+	else
+		err = gssx_enc_bool(xdr, 0);
+	if (err)
+		goto done;
+
+	/* arg->cred_handle */
+	if (arg->cred_handle)
+		err = gssx_enc_cred(xdr, arg->cred_handle);
+	else
+		err = gssx_enc_bool(xdr, 0);
+	if (err)
+		goto done;
+
+	/* arg->input_token */
+	err = gssx_enc_in_token(xdr, &arg->input_token);
+	if (err)
+		goto done;
+
+	/* arg->input_cb */
+	if (arg->input_cb)
+		err = gssx_enc_cb(xdr, arg->input_cb);
+	else
+		err = gssx_enc_bool(xdr, 0);
+	if (err)
+		goto done;
+
+	err = gssx_enc_bool(xdr, arg->ret_deleg_cred);
+	if (err)
+		goto done;
+
+	/* leave options empty for now, will add once we have any options
+	 * to pass up at all */
+	/* arg->options */
+	err = dummy_enc_opt_array(xdr, &arg->options);
+
+	xdr_inline_pages(&req->rq_rcv_buf,
+		PAGE_SIZE/2 /* pretty arbitrary */,
+		arg->pages, 0 /* page base */, arg->npages * PAGE_SIZE);
+done:
+	if (err)
+		dprintk("RPC:       gssx_enc_accept_sec_context: %d\n", err);
+}
+
+int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
+				struct xdr_stream *xdr,
+				struct gssx_res_accept_sec_context *res)
+{
+	u32 value_follows;
+	int err;
+	struct page *scratch;
+
+	scratch = alloc_page(GFP_KERNEL);
+	if (!scratch)
+		return -ENOMEM;
+	xdr_set_scratch_buffer(xdr, page_address(scratch), PAGE_SIZE);
+
+	/* res->status */
+	err = gssx_dec_status(xdr, &res->status);
+	if (err)
+		goto out_free;
+
+	/* res->context_handle */
+	err = gssx_dec_bool(xdr, &value_follows);
+	if (err)
+		goto out_free;
+	if (value_follows) {
+		err = gssx_dec_ctx(xdr, res->context_handle);
+		if (err)
+			goto out_free;
+	} else {
+		res->context_handle = NULL;
+	}
+
+	/* res->output_token */
+	err = gssx_dec_bool(xdr, &value_follows);
+	if (err)
+		goto out_free;
+	if (value_follows) {
+		err = gssx_dec_buffer(xdr, res->output_token);
+		if (err)
+			goto out_free;
+	} else {
+		res->output_token = NULL;
+	}
+
+	/* res->delegated_cred_handle */
+	err = gssx_dec_bool(xdr, &value_follows);
+	if (err)
+		goto out_free;
+	if (value_follows) {
+		/* we do not support upcall servers sending this data. */
+		err = -EINVAL;
+		goto out_free;
+	}
+
+	/* res->options */
+	err = gssx_dec_option_array(xdr, &res->options);
+
+out_free:
+	__free_page(scratch);
+	return err;
+}
diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.h b/net/sunrpc/auth_gss/gss_rpc_xdr.h
new file mode 100644
index 000000000..9d88c6239
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.h
@@ -0,0 +1,267 @@
+/*
+ * GSS Proxy upcall module
+ *
+ *  Copyright (C) 2012 Simo Sorce <simo@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _LINUX_GSS_RPC_XDR_H
+#define _LINUX_GSS_RPC_XDR_H
+
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/xprtsock.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_AUTH
+#endif
+
+#define LUCID_OPTION "exported_context_type"
+#define LUCID_VALUE  "linux_lucid_v1"
+#define CREDS_OPTION "exported_creds_type"
+#define CREDS_VALUE  "linux_creds_v1"
+
+typedef struct xdr_netobj gssx_buffer;
+typedef struct xdr_netobj utf8string;
+typedef struct xdr_netobj gssx_OID;
+
+enum gssx_cred_usage {
+	GSSX_C_INITIATE = 1,
+	GSSX_C_ACCEPT = 2,
+	GSSX_C_BOTH = 3,
+};
+
+struct gssx_option {
+	gssx_buffer option;
+	gssx_buffer value;
+};
+
+struct gssx_option_array {
+	u32 count;
+	struct gssx_option *data;
+};
+
+struct gssx_status {
+	u64 major_status;
+	gssx_OID mech;
+	u64 minor_status;
+	utf8string major_status_string;
+	utf8string minor_status_string;
+	gssx_buffer server_ctx;
+	struct gssx_option_array options;
+};
+
+struct gssx_call_ctx {
+	utf8string locale;
+	gssx_buffer server_ctx;
+	struct gssx_option_array options;
+};
+
+struct gssx_name_attr {
+	gssx_buffer attr;
+	gssx_buffer value;
+	struct gssx_option_array extensions;
+};
+
+struct gssx_name_attr_array {
+	u32 count;
+	struct gssx_name_attr *data;
+};
+
+struct gssx_name {
+	gssx_buffer display_name;
+};
+typedef struct gssx_name gssx_name;
+
+struct gssx_cred_element {
+	gssx_name MN;
+	gssx_OID mech;
+	u32 cred_usage;
+	u64 initiator_time_rec;
+	u64 acceptor_time_rec;
+	struct gssx_option_array options;
+};
+
+struct gssx_cred_element_array {
+	u32 count;
+	struct gssx_cred_element *data;
+};
+
+struct gssx_cred {
+	gssx_name desired_name;
+	struct gssx_cred_element_array elements;
+	gssx_buffer cred_handle_reference;
+	u32 needs_release;
+};
+
+struct gssx_ctx {
+	gssx_buffer exported_context_token;
+	gssx_buffer state;
+	u32 need_release;
+	gssx_OID mech;
+	gssx_name src_name;
+	gssx_name targ_name;
+	u64 lifetime;
+	u64 ctx_flags;
+	u32 locally_initiated;
+	u32 open;
+	struct gssx_option_array options;
+};
+
+struct gssx_cb {
+	u64 initiator_addrtype;
+	gssx_buffer initiator_address;
+	u64 acceptor_addrtype;
+	gssx_buffer acceptor_address;
+	gssx_buffer application_data;
+};
+
+
+/* This structure is not defined in the protocol.
+ * It is used in the kernel to carry around a big buffer
+ * as a set of pages */
+struct gssp_in_token {
+	struct page **pages;	/* Array of contiguous pages */
+	unsigned int page_base;	/* Start of page data */
+	unsigned int page_len;	/* Length of page data */
+};
+
+struct gssx_arg_accept_sec_context {
+	struct gssx_call_ctx call_ctx;
+	struct gssx_ctx *context_handle;
+	struct gssx_cred *cred_handle;
+	struct gssp_in_token input_token;
+	struct gssx_cb *input_cb;
+	u32 ret_deleg_cred;
+	struct gssx_option_array options;
+	struct page **pages;
+	unsigned int npages;
+};
+
+struct gssx_res_accept_sec_context {
+	struct gssx_status status;
+	struct gssx_ctx *context_handle;
+	gssx_buffer *output_token;
+	/* struct gssx_cred *delegated_cred_handle; not used in kernel */
+	struct gssx_option_array options;
+};
+
+
+
+#define gssx_enc_indicate_mechs NULL
+#define gssx_dec_indicate_mechs NULL
+#define gssx_enc_get_call_context NULL
+#define gssx_dec_get_call_context NULL
+#define gssx_enc_import_and_canon_name NULL
+#define gssx_dec_import_and_canon_name NULL
+#define gssx_enc_export_cred NULL
+#define gssx_dec_export_cred NULL
+#define gssx_enc_import_cred NULL
+#define gssx_dec_import_cred NULL
+#define gssx_enc_acquire_cred NULL
+#define gssx_dec_acquire_cred NULL
+#define gssx_enc_store_cred NULL
+#define gssx_dec_store_cred NULL
+#define gssx_enc_init_sec_context NULL
+#define gssx_dec_init_sec_context NULL
+void gssx_enc_accept_sec_context(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 struct gssx_arg_accept_sec_context *args);
+int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
+				struct xdr_stream *xdr,
+				struct gssx_res_accept_sec_context *res);
+#define gssx_enc_release_handle NULL
+#define gssx_dec_release_handle NULL
+#define gssx_enc_get_mic NULL
+#define gssx_dec_get_mic NULL
+#define gssx_enc_verify NULL
+#define gssx_dec_verify NULL
+#define gssx_enc_wrap NULL
+#define gssx_dec_wrap NULL
+#define gssx_enc_unwrap NULL
+#define gssx_dec_unwrap NULL
+#define gssx_enc_wrap_size_limit NULL
+#define gssx_dec_wrap_size_limit NULL
+
+/* non implemented calls are set to 0 size */
+#define GSSX_ARG_indicate_mechs_sz 0
+#define GSSX_RES_indicate_mechs_sz 0
+#define GSSX_ARG_get_call_context_sz 0
+#define GSSX_RES_get_call_context_sz 0
+#define GSSX_ARG_import_and_canon_name_sz 0
+#define GSSX_RES_import_and_canon_name_sz 0
+#define GSSX_ARG_export_cred_sz 0
+#define GSSX_RES_export_cred_sz 0
+#define GSSX_ARG_import_cred_sz 0
+#define GSSX_RES_import_cred_sz 0
+#define GSSX_ARG_acquire_cred_sz 0
+#define GSSX_RES_acquire_cred_sz 0
+#define GSSX_ARG_store_cred_sz 0
+#define GSSX_RES_store_cred_sz 0
+#define GSSX_ARG_init_sec_context_sz 0
+#define GSSX_RES_init_sec_context_sz 0
+
+#define GSSX_default_in_call_ctx_sz (4 + 4 + 4 + \
+			8 + sizeof(LUCID_OPTION) + sizeof(LUCID_VALUE) + \
+			8 + sizeof(CREDS_OPTION) + sizeof(CREDS_VALUE))
+#define GSSX_default_in_ctx_hndl_sz (4 + 4+8 + 4 + 4 + 6*4 + 6*4 + 8 + 8 + \
+					4 + 4 + 4)
+#define GSSX_default_in_cred_sz 4 /* we send in no cred_handle */
+#define GSSX_default_in_token_sz 4 /* does *not* include token data */
+#define GSSX_default_in_cb_sz 4 /* we do not use channel bindings */
+#define GSSX_ARG_accept_sec_context_sz (GSSX_default_in_call_ctx_sz + \
+					GSSX_default_in_ctx_hndl_sz + \
+					GSSX_default_in_cred_sz + \
+					GSSX_default_in_token_sz + \
+					GSSX_default_in_cb_sz + \
+					4 /* no deleg creds boolean */ + \
+					4) /* empty options */
+
+/* somewhat arbitrary numbers but large enough (we ignore some of the data
+ * sent down, but it is part of the protocol so we need enough space to take
+ * it in) */
+#define GSSX_default_status_sz 8 + 24 + 8 + 256 + 256 + 16 + 4
+#define GSSX_max_output_handle_sz 128
+#define GSSX_max_oid_sz 16
+#define GSSX_max_princ_sz 256
+#define GSSX_default_ctx_sz (GSSX_max_output_handle_sz + \
+			     16 + 4 + GSSX_max_oid_sz + \
+			     2 * GSSX_max_princ_sz + \
+			     8 + 8 + 4 + 4 + 4)
+#define GSSX_max_output_token_sz 1024
+/* grouplist not included; we allocate separate pages for that: */
+#define GSSX_max_creds_sz (4 + 4 + 4 /* + NGROUPS_MAX*4 */)
+#define GSSX_RES_accept_sec_context_sz (GSSX_default_status_sz + \
+					GSSX_default_ctx_sz + \
+					GSSX_max_output_token_sz + \
+					4 + GSSX_max_creds_sz)
+
+#define GSSX_ARG_release_handle_sz 0
+#define GSSX_RES_release_handle_sz 0
+#define GSSX_ARG_get_mic_sz 0
+#define GSSX_RES_get_mic_sz 0
+#define GSSX_ARG_verify_sz 0
+#define GSSX_RES_verify_sz 0
+#define GSSX_ARG_wrap_sz 0
+#define GSSX_RES_wrap_sz 0
+#define GSSX_ARG_unwrap_sz 0
+#define GSSX_RES_unwrap_sz 0
+#define GSSX_ARG_wrap_size_limit_sz 0
+#define GSSX_RES_wrap_size_limit_sz 0
+
+
+
+#endif /* _LINUX_GSS_RPC_XDR_H */
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
new file mode 100644
index 000000000..1095be9c8
--- /dev/null
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -0,0 +1,1862 @@
+/*
+ * Neil Brown <neilb@cse.unsw.edu.au>
+ * J. Bruce Fields <bfields@umich.edu>
+ * Andy Adamson <andros@umich.edu>
+ * Dug Song <dugsong@monkey.org>
+ *
+ * RPCSEC_GSS server authentication.
+ * This implements RPCSEC_GSS as defined in rfc2203 (rpcsec_gss) and rfc2078
+ * (gssapi)
+ *
+ * The RPCSEC_GSS involves three stages:
+ *  1/ context creation
+ *  2/ data exchange
+ *  3/ context destruction
+ *
+ * Context creation is handled largely by upcalls to user-space.
+ *  In particular, GSS_Accept_sec_context is handled by an upcall
+ * Data exchange is handled entirely within the kernel
+ *  In particular, GSS_GetMIC, GSS_VerifyMIC, GSS_Seal, GSS_Unseal are in-kernel.
+ * Context destruction is handled in-kernel
+ *  GSS_Delete_sec_context is in-kernel
+ *
+ * Context creation is initiated by a RPCSEC_GSS_INIT request arriving.
+ * The context handle and gss_token are used as a key into the rpcsec_init cache.
+ * The content of this cache includes some of the outputs of GSS_Accept_sec_context,
+ * being major_status, minor_status, context_handle, reply_token.
+ * These are sent back to the client.
+ * Sequence window management is handled by the kernel.  The window size if currently
+ * a compile time constant.
+ *
+ * When user-space is happy that a context is established, it places an entry
+ * in the rpcsec_context cache. The key for this cache is the context_handle.
+ * The content includes:
+ *   uid/gidlist - for determining access rights
+ *   mechanism type
+ *   mechanism specific information, such as a key
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <linux/user_namespace.h>
+
+#include <linux/sunrpc/auth_gss.h>
+#include <linux/sunrpc/gss_err.h>
+#include <linux/sunrpc/svcauth.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/cache.h>
+#include "gss_rpc_upcall.h"
+
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_AUTH
+#endif
+
+/* The rpcsec_init cache is used for mapping RPCSEC_GSS_{,CONT_}INIT requests
+ * into replies.
+ *
+ * Key is context handle (\x if empty) and gss_token.
+ * Content is major_status minor_status (integers) context_handle, reply_token.
+ *
+ */
+
+static int netobj_equal(struct xdr_netobj *a, struct xdr_netobj *b)
+{
+	return a->len == b->len && 0 == memcmp(a->data, b->data, a->len);
+}
+
+#define	RSI_HASHBITS	6
+#define	RSI_HASHMAX	(1<<RSI_HASHBITS)
+
+struct rsi {
+	struct cache_head	h;
+	struct xdr_netobj	in_handle, in_token;
+	struct xdr_netobj	out_handle, out_token;
+	int			major_status, minor_status;
+};
+
+static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old);
+static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item);
+
+static void rsi_free(struct rsi *rsii)
+{
+	kfree(rsii->in_handle.data);
+	kfree(rsii->in_token.data);
+	kfree(rsii->out_handle.data);
+	kfree(rsii->out_token.data);
+}
+
+static void rsi_put(struct kref *ref)
+{
+	struct rsi *rsii = container_of(ref, struct rsi, h.ref);
+	rsi_free(rsii);
+	kfree(rsii);
+}
+
+static inline int rsi_hash(struct rsi *item)
+{
+	return hash_mem(item->in_handle.data, item->in_handle.len, RSI_HASHBITS)
+	     ^ hash_mem(item->in_token.data, item->in_token.len, RSI_HASHBITS);
+}
+
+static int rsi_match(struct cache_head *a, struct cache_head *b)
+{
+	struct rsi *item = container_of(a, struct rsi, h);
+	struct rsi *tmp = container_of(b, struct rsi, h);
+	return netobj_equal(&item->in_handle, &tmp->in_handle) &&
+	       netobj_equal(&item->in_token, &tmp->in_token);
+}
+
+static int dup_to_netobj(struct xdr_netobj *dst, char *src, int len)
+{
+	dst->len = len;
+	dst->data = (len ? kmemdup(src, len, GFP_KERNEL) : NULL);
+	if (len && !dst->data)
+		return -ENOMEM;
+	return 0;
+}
+
+static inline int dup_netobj(struct xdr_netobj *dst, struct xdr_netobj *src)
+{
+	return dup_to_netobj(dst, src->data, src->len);
+}
+
+static void rsi_init(struct cache_head *cnew, struct cache_head *citem)
+{
+	struct rsi *new = container_of(cnew, struct rsi, h);
+	struct rsi *item = container_of(citem, struct rsi, h);
+
+	new->out_handle.data = NULL;
+	new->out_handle.len = 0;
+	new->out_token.data = NULL;
+	new->out_token.len = 0;
+	new->in_handle.len = item->in_handle.len;
+	item->in_handle.len = 0;
+	new->in_token.len = item->in_token.len;
+	item->in_token.len = 0;
+	new->in_handle.data = item->in_handle.data;
+	item->in_handle.data = NULL;
+	new->in_token.data = item->in_token.data;
+	item->in_token.data = NULL;
+}
+
+static void update_rsi(struct cache_head *cnew, struct cache_head *citem)
+{
+	struct rsi *new = container_of(cnew, struct rsi, h);
+	struct rsi *item = container_of(citem, struct rsi, h);
+
+	BUG_ON(new->out_handle.data || new->out_token.data);
+	new->out_handle.len = item->out_handle.len;
+	item->out_handle.len = 0;
+	new->out_token.len = item->out_token.len;
+	item->out_token.len = 0;
+	new->out_handle.data = item->out_handle.data;
+	item->out_handle.data = NULL;
+	new->out_token.data = item->out_token.data;
+	item->out_token.data = NULL;
+
+	new->major_status = item->major_status;
+	new->minor_status = item->minor_status;
+}
+
+static struct cache_head *rsi_alloc(void)
+{
+	struct rsi *rsii = kmalloc(sizeof(*rsii), GFP_KERNEL);
+	if (rsii)
+		return &rsii->h;
+	else
+		return NULL;
+}
+
+static void rsi_request(struct cache_detail *cd,
+		       struct cache_head *h,
+		       char **bpp, int *blen)
+{
+	struct rsi *rsii = container_of(h, struct rsi, h);
+
+	qword_addhex(bpp, blen, rsii->in_handle.data, rsii->in_handle.len);
+	qword_addhex(bpp, blen, rsii->in_token.data, rsii->in_token.len);
+	(*bpp)[-1] = '\n';
+}
+
+static int rsi_parse(struct cache_detail *cd,
+		    char *mesg, int mlen)
+{
+	/* context token expiry major minor context token */
+	char *buf = mesg;
+	char *ep;
+	int len;
+	struct rsi rsii, *rsip = NULL;
+	time_t expiry;
+	int status = -EINVAL;
+
+	memset(&rsii, 0, sizeof(rsii));
+	/* handle */
+	len = qword_get(&mesg, buf, mlen);
+	if (len < 0)
+		goto out;
+	status = -ENOMEM;
+	if (dup_to_netobj(&rsii.in_handle, buf, len))
+		goto out;
+
+	/* token */
+	len = qword_get(&mesg, buf, mlen);
+	status = -EINVAL;
+	if (len < 0)
+		goto out;
+	status = -ENOMEM;
+	if (dup_to_netobj(&rsii.in_token, buf, len))
+		goto out;
+
+	rsip = rsi_lookup(cd, &rsii);
+	if (!rsip)
+		goto out;
+
+	rsii.h.flags = 0;
+	/* expiry */
+	expiry = get_expiry(&mesg);
+	status = -EINVAL;
+	if (expiry == 0)
+		goto out;
+
+	/* major/minor */
+	len = qword_get(&mesg, buf, mlen);
+	if (len <= 0)
+		goto out;
+	rsii.major_status = simple_strtoul(buf, &ep, 10);
+	if (*ep)
+		goto out;
+	len = qword_get(&mesg, buf, mlen);
+	if (len <= 0)
+		goto out;
+	rsii.minor_status = simple_strtoul(buf, &ep, 10);
+	if (*ep)
+		goto out;
+
+	/* out_handle */
+	len = qword_get(&mesg, buf, mlen);
+	if (len < 0)
+		goto out;
+	status = -ENOMEM;
+	if (dup_to_netobj(&rsii.out_handle, buf, len))
+		goto out;
+
+	/* out_token */
+	len = qword_get(&mesg, buf, mlen);
+	status = -EINVAL;
+	if (len < 0)
+		goto out;
+	status = -ENOMEM;
+	if (dup_to_netobj(&rsii.out_token, buf, len))
+		goto out;
+	rsii.h.expiry_time = expiry;
+	rsip = rsi_update(cd, &rsii, rsip);
+	status = 0;
+out:
+	rsi_free(&rsii);
+	if (rsip)
+		cache_put(&rsip->h, cd);
+	else
+		status = -ENOMEM;
+	return status;
+}
+
+static struct cache_detail rsi_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= RSI_HASHMAX,
+	.name           = "auth.rpcsec.init",
+	.cache_put      = rsi_put,
+	.cache_request  = rsi_request,
+	.cache_parse    = rsi_parse,
+	.match		= rsi_match,
+	.init		= rsi_init,
+	.update		= update_rsi,
+	.alloc		= rsi_alloc,
+};
+
+static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item)
+{
+	struct cache_head *ch;
+	int hash = rsi_hash(item);
+
+	ch = sunrpc_cache_lookup(cd, &item->h, hash);
+	if (ch)
+		return container_of(ch, struct rsi, h);
+	else
+		return NULL;
+}
+
+static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old)
+{
+	struct cache_head *ch;
+	int hash = rsi_hash(new);
+
+	ch = sunrpc_cache_update(cd, &new->h,
+				 &old->h, hash);
+	if (ch)
+		return container_of(ch, struct rsi, h);
+	else
+		return NULL;
+}
+
+
+/*
+ * The rpcsec_context cache is used to store a context that is
+ * used in data exchange.
+ * The key is a context handle. The content is:
+ *  uid, gidlist, mechanism, service-set, mech-specific-data
+ */
+
+#define	RSC_HASHBITS	10
+#define	RSC_HASHMAX	(1<<RSC_HASHBITS)
+
+#define GSS_SEQ_WIN	128
+
+struct gss_svc_seq_data {
+	/* highest seq number seen so far: */
+	int			sd_max;
+	/* for i such that sd_max-GSS_SEQ_WIN < i <= sd_max, the i-th bit of
+	 * sd_win is nonzero iff sequence number i has been seen already: */
+	unsigned long		sd_win[GSS_SEQ_WIN/BITS_PER_LONG];
+	spinlock_t		sd_lock;
+};
+
+struct rsc {
+	struct cache_head	h;
+	struct xdr_netobj	handle;
+	struct svc_cred		cred;
+	struct gss_svc_seq_data	seqdata;
+	struct gss_ctx		*mechctx;
+};
+
+static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old);
+static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item);
+
+static void rsc_free(struct rsc *rsci)
+{
+	kfree(rsci->handle.data);
+	if (rsci->mechctx)
+		gss_delete_sec_context(&rsci->mechctx);
+	free_svc_cred(&rsci->cred);
+}
+
+static void rsc_put(struct kref *ref)
+{
+	struct rsc *rsci = container_of(ref, struct rsc, h.ref);
+
+	rsc_free(rsci);
+	kfree(rsci);
+}
+
+static inline int
+rsc_hash(struct rsc *rsci)
+{
+	return hash_mem(rsci->handle.data, rsci->handle.len, RSC_HASHBITS);
+}
+
+static int
+rsc_match(struct cache_head *a, struct cache_head *b)
+{
+	struct rsc *new = container_of(a, struct rsc, h);
+	struct rsc *tmp = container_of(b, struct rsc, h);
+
+	return netobj_equal(&new->handle, &tmp->handle);
+}
+
+static void
+rsc_init(struct cache_head *cnew, struct cache_head *ctmp)
+{
+	struct rsc *new = container_of(cnew, struct rsc, h);
+	struct rsc *tmp = container_of(ctmp, struct rsc, h);
+
+	new->handle.len = tmp->handle.len;
+	tmp->handle.len = 0;
+	new->handle.data = tmp->handle.data;
+	tmp->handle.data = NULL;
+	new->mechctx = NULL;
+	init_svc_cred(&new->cred);
+}
+
+static void
+update_rsc(struct cache_head *cnew, struct cache_head *ctmp)
+{
+	struct rsc *new = container_of(cnew, struct rsc, h);
+	struct rsc *tmp = container_of(ctmp, struct rsc, h);
+
+	new->mechctx = tmp->mechctx;
+	tmp->mechctx = NULL;
+	memset(&new->seqdata, 0, sizeof(new->seqdata));
+	spin_lock_init(&new->seqdata.sd_lock);
+	new->cred = tmp->cred;
+	init_svc_cred(&tmp->cred);
+}
+
+static struct cache_head *
+rsc_alloc(void)
+{
+	struct rsc *rsci = kmalloc(sizeof(*rsci), GFP_KERNEL);
+	if (rsci)
+		return &rsci->h;
+	else
+		return NULL;
+}
+
+static int rsc_parse(struct cache_detail *cd,
+		     char *mesg, int mlen)
+{
+	/* contexthandle expiry [ uid gid N <n gids> mechname ...mechdata... ] */
+	char *buf = mesg;
+	int id;
+	int len, rv;
+	struct rsc rsci, *rscp = NULL;
+	time_t expiry;
+	int status = -EINVAL;
+	struct gss_api_mech *gm = NULL;
+
+	memset(&rsci, 0, sizeof(rsci));
+	/* context handle */
+	len = qword_get(&mesg, buf, mlen);
+	if (len < 0) goto out;
+	status = -ENOMEM;
+	if (dup_to_netobj(&rsci.handle, buf, len))
+		goto out;
+
+	rsci.h.flags = 0;
+	/* expiry */
+	expiry = get_expiry(&mesg);
+	status = -EINVAL;
+	if (expiry == 0)
+		goto out;
+
+	rscp = rsc_lookup(cd, &rsci);
+	if (!rscp)
+		goto out;
+
+	/* uid, or NEGATIVE */
+	rv = get_int(&mesg, &id);
+	if (rv == -EINVAL)
+		goto out;
+	if (rv == -ENOENT)
+		set_bit(CACHE_NEGATIVE, &rsci.h.flags);
+	else {
+		int N, i;
+
+		/*
+		 * NOTE: we skip uid_valid()/gid_valid() checks here:
+		 * instead, * -1 id's are later mapped to the
+		 * (export-specific) anonymous id by nfsd_setuser.
+		 *
+		 * (But supplementary gid's get no such special
+		 * treatment so are checked for validity here.)
+		 */
+		/* uid */
+		rsci.cred.cr_uid = make_kuid(&init_user_ns, id);
+
+		/* gid */
+		if (get_int(&mesg, &id))
+			goto out;
+		rsci.cred.cr_gid = make_kgid(&init_user_ns, id);
+
+		/* number of additional gid's */
+		if (get_int(&mesg, &N))
+			goto out;
+		if (N < 0 || N > NGROUPS_MAX)
+			goto out;
+		status = -ENOMEM;
+		rsci.cred.cr_group_info = groups_alloc(N);
+		if (rsci.cred.cr_group_info == NULL)
+			goto out;
+
+		/* gid's */
+		status = -EINVAL;
+		for (i=0; i<N; i++) {
+			kgid_t kgid;
+			if (get_int(&mesg, &id))
+				goto out;
+			kgid = make_kgid(&init_user_ns, id);
+			if (!gid_valid(kgid))
+				goto out;
+			GROUP_AT(rsci.cred.cr_group_info, i) = kgid;
+		}
+
+		/* mech name */
+		len = qword_get(&mesg, buf, mlen);
+		if (len < 0)
+			goto out;
+		gm = rsci.cred.cr_gss_mech = gss_mech_get_by_name(buf);
+		status = -EOPNOTSUPP;
+		if (!gm)
+			goto out;
+
+		status = -EINVAL;
+		/* mech-specific data: */
+		len = qword_get(&mesg, buf, mlen);
+		if (len < 0)
+			goto out;
+		status = gss_import_sec_context(buf, len, gm, &rsci.mechctx,
+						NULL, GFP_KERNEL);
+		if (status)
+			goto out;
+
+		/* get client name */
+		len = qword_get(&mesg, buf, mlen);
+		if (len > 0) {
+			rsci.cred.cr_principal = kstrdup(buf, GFP_KERNEL);
+			if (!rsci.cred.cr_principal) {
+				status = -ENOMEM;
+				goto out;
+			}
+		}
+
+	}
+	rsci.h.expiry_time = expiry;
+	rscp = rsc_update(cd, &rsci, rscp);
+	status = 0;
+out:
+	rsc_free(&rsci);
+	if (rscp)
+		cache_put(&rscp->h, cd);
+	else
+		status = -ENOMEM;
+	return status;
+}
+
+static struct cache_detail rsc_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= RSC_HASHMAX,
+	.name		= "auth.rpcsec.context",
+	.cache_put	= rsc_put,
+	.cache_parse	= rsc_parse,
+	.match		= rsc_match,
+	.init		= rsc_init,
+	.update		= update_rsc,
+	.alloc		= rsc_alloc,
+};
+
+static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item)
+{
+	struct cache_head *ch;
+	int hash = rsc_hash(item);
+
+	ch = sunrpc_cache_lookup(cd, &item->h, hash);
+	if (ch)
+		return container_of(ch, struct rsc, h);
+	else
+		return NULL;
+}
+
+static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old)
+{
+	struct cache_head *ch;
+	int hash = rsc_hash(new);
+
+	ch = sunrpc_cache_update(cd, &new->h,
+				 &old->h, hash);
+	if (ch)
+		return container_of(ch, struct rsc, h);
+	else
+		return NULL;
+}
+
+
+static struct rsc *
+gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle)
+{
+	struct rsc rsci;
+	struct rsc *found;
+
+	memset(&rsci, 0, sizeof(rsci));
+	if (dup_to_netobj(&rsci.handle, handle->data, handle->len))
+		return NULL;
+	found = rsc_lookup(cd, &rsci);
+	rsc_free(&rsci);
+	if (!found)
+		return NULL;
+	if (cache_check(cd, &found->h, NULL))
+		return NULL;
+	return found;
+}
+
+/* Implements sequence number algorithm as specified in RFC 2203. */
+static int
+gss_check_seq_num(struct rsc *rsci, int seq_num)
+{
+	struct gss_svc_seq_data *sd = &rsci->seqdata;
+
+	spin_lock(&sd->sd_lock);
+	if (seq_num > sd->sd_max) {
+		if (seq_num >= sd->sd_max + GSS_SEQ_WIN) {
+			memset(sd->sd_win,0,sizeof(sd->sd_win));
+			sd->sd_max = seq_num;
+		} else while (sd->sd_max < seq_num) {
+			sd->sd_max++;
+			__clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win);
+		}
+		__set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win);
+		goto ok;
+	} else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) {
+		goto drop;
+	}
+	/* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */
+	if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))
+		goto drop;
+ok:
+	spin_unlock(&sd->sd_lock);
+	return 1;
+drop:
+	spin_unlock(&sd->sd_lock);
+	return 0;
+}
+
+static inline u32 round_up_to_quad(u32 i)
+{
+	return (i + 3 ) & ~3;
+}
+
+static inline int
+svc_safe_getnetobj(struct kvec *argv, struct xdr_netobj *o)
+{
+	int l;
+
+	if (argv->iov_len < 4)
+		return -1;
+	o->len = svc_getnl(argv);
+	l = round_up_to_quad(o->len);
+	if (argv->iov_len < l)
+		return -1;
+	o->data = argv->iov_base;
+	argv->iov_base += l;
+	argv->iov_len -= l;
+	return 0;
+}
+
+static inline int
+svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o)
+{
+	u8 *p;
+
+	if (resv->iov_len + 4 > PAGE_SIZE)
+		return -1;
+	svc_putnl(resv, o->len);
+	p = resv->iov_base + resv->iov_len;
+	resv->iov_len += round_up_to_quad(o->len);
+	if (resv->iov_len > PAGE_SIZE)
+		return -1;
+	memcpy(p, o->data, o->len);
+	memset(p + o->len, 0, round_up_to_quad(o->len) - o->len);
+	return 0;
+}
+
+/*
+ * Verify the checksum on the header and return SVC_OK on success.
+ * Otherwise, return SVC_DROP (in the case of a bad sequence number)
+ * or return SVC_DENIED and indicate error in authp.
+ */
+static int
+gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
+		  __be32 *rpcstart, struct rpc_gss_wire_cred *gc, __be32 *authp)
+{
+	struct gss_ctx		*ctx_id = rsci->mechctx;
+	struct xdr_buf		rpchdr;
+	struct xdr_netobj	checksum;
+	u32			flavor = 0;
+	struct kvec		*argv = &rqstp->rq_arg.head[0];
+	struct kvec		iov;
+
+	/* data to compute the checksum over: */
+	iov.iov_base = rpcstart;
+	iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart;
+	xdr_buf_from_iov(&iov, &rpchdr);
+
+	*authp = rpc_autherr_badverf;
+	if (argv->iov_len < 4)
+		return SVC_DENIED;
+	flavor = svc_getnl(argv);
+	if (flavor != RPC_AUTH_GSS)
+		return SVC_DENIED;
+	if (svc_safe_getnetobj(argv, &checksum))
+		return SVC_DENIED;
+
+	if (rqstp->rq_deferred) /* skip verification of revisited request */
+		return SVC_OK;
+	if (gss_verify_mic(ctx_id, &rpchdr, &checksum) != GSS_S_COMPLETE) {
+		*authp = rpcsec_gsserr_credproblem;
+		return SVC_DENIED;
+	}
+
+	if (gc->gc_seq > MAXSEQ) {
+		dprintk("RPC:       svcauth_gss: discarding request with "
+				"large sequence number %d\n", gc->gc_seq);
+		*authp = rpcsec_gsserr_ctxproblem;
+		return SVC_DENIED;
+	}
+	if (!gss_check_seq_num(rsci, gc->gc_seq)) {
+		dprintk("RPC:       svcauth_gss: discarding request with "
+				"old sequence number %d\n", gc->gc_seq);
+		return SVC_DROP;
+	}
+	return SVC_OK;
+}
+
+static int
+gss_write_null_verf(struct svc_rqst *rqstp)
+{
+	__be32     *p;
+
+	svc_putnl(rqstp->rq_res.head, RPC_AUTH_NULL);
+	p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
+	/* don't really need to check if head->iov_len > PAGE_SIZE ... */
+	*p++ = 0;
+	if (!xdr_ressize_check(rqstp, p))
+		return -1;
+	return 0;
+}
+
+static int
+gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
+{
+	__be32			xdr_seq;
+	u32			maj_stat;
+	struct xdr_buf		verf_data;
+	struct xdr_netobj	mic;
+	__be32			*p;
+	struct kvec		iov;
+
+	svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS);
+	xdr_seq = htonl(seq);
+
+	iov.iov_base = &xdr_seq;
+	iov.iov_len = sizeof(xdr_seq);
+	xdr_buf_from_iov(&iov, &verf_data);
+	p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
+	mic.data = (u8 *)(p + 1);
+	maj_stat = gss_get_mic(ctx_id, &verf_data, &mic);
+	if (maj_stat != GSS_S_COMPLETE)
+		return -1;
+	*p++ = htonl(mic.len);
+	memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len);
+	p += XDR_QUADLEN(mic.len);
+	if (!xdr_ressize_check(rqstp, p))
+		return -1;
+	return 0;
+}
+
+struct gss_domain {
+	struct auth_domain	h;
+	u32			pseudoflavor;
+};
+
+static struct auth_domain *
+find_gss_auth_domain(struct gss_ctx *ctx, u32 svc)
+{
+	char *name;
+
+	name = gss_service_to_auth_domain_name(ctx->mech_type, svc);
+	if (!name)
+		return NULL;
+	return auth_domain_find(name);
+}
+
+static struct auth_ops svcauthops_gss;
+
+u32 svcauth_gss_flavor(struct auth_domain *dom)
+{
+	struct gss_domain *gd = container_of(dom, struct gss_domain, h);
+
+	return gd->pseudoflavor;
+}
+
+EXPORT_SYMBOL_GPL(svcauth_gss_flavor);
+
+int
+svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name)
+{
+	struct gss_domain	*new;
+	struct auth_domain	*test;
+	int			stat = -ENOMEM;
+
+	new = kmalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		goto out;
+	kref_init(&new->h.ref);
+	new->h.name = kstrdup(name, GFP_KERNEL);
+	if (!new->h.name)
+		goto out_free_dom;
+	new->h.flavour = &svcauthops_gss;
+	new->pseudoflavor = pseudoflavor;
+
+	stat = 0;
+	test = auth_domain_lookup(name, &new->h);
+	if (test != &new->h) { /* Duplicate registration */
+		auth_domain_put(test);
+		kfree(new->h.name);
+		goto out_free_dom;
+	}
+	return 0;
+
+out_free_dom:
+	kfree(new);
+out:
+	return stat;
+}
+
+EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor);
+
+static inline int
+read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
+{
+	__be32  raw;
+	int     status;
+
+	status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
+	if (status)
+		return status;
+	*obj = ntohl(raw);
+	return 0;
+}
+
+/* It would be nice if this bit of code could be shared with the client.
+ * Obstacles:
+ *	The client shouldn't malloc(), would have to pass in own memory.
+ *	The server uses base of head iovec as read pointer, while the
+ *	client uses separate pointer. */
+static int
+unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
+{
+	int stat = -EINVAL;
+	u32 integ_len, maj_stat;
+	struct xdr_netobj mic;
+	struct xdr_buf integ_buf;
+
+	/* Did we already verify the signature on the original pass through? */
+	if (rqstp->rq_deferred)
+		return 0;
+
+	integ_len = svc_getnl(&buf->head[0]);
+	if (integ_len & 3)
+		return stat;
+	if (integ_len > buf->len)
+		return stat;
+	if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
+		BUG();
+	/* copy out mic... */
+	if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
+		BUG();
+	if (mic.len > RPC_MAX_AUTH_SIZE)
+		return stat;
+	mic.data = kmalloc(mic.len, GFP_KERNEL);
+	if (!mic.data)
+		return stat;
+	if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len))
+		goto out;
+	maj_stat = gss_verify_mic(ctx, &integ_buf, &mic);
+	if (maj_stat != GSS_S_COMPLETE)
+		goto out;
+	if (svc_getnl(&buf->head[0]) != seq)
+		goto out;
+	/* trim off the mic at the end before returning */
+	xdr_buf_trim(buf, mic.len + 4);
+	stat = 0;
+out:
+	kfree(mic.data);
+	return stat;
+}
+
+static inline int
+total_buf_len(struct xdr_buf *buf)
+{
+	return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len;
+}
+
+static void
+fix_priv_head(struct xdr_buf *buf, int pad)
+{
+	if (buf->page_len == 0) {
+		/* We need to adjust head and buf->len in tandem in this
+		 * case to make svc_defer() work--it finds the original
+		 * buffer start using buf->len - buf->head[0].iov_len. */
+		buf->head[0].iov_len -= pad;
+	}
+}
+
+static int
+unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
+{
+	u32 priv_len, maj_stat;
+	int pad, saved_len, remaining_len, offset;
+
+	clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
+
+	priv_len = svc_getnl(&buf->head[0]);
+	if (rqstp->rq_deferred) {
+		/* Already decrypted last time through! The sequence number
+		 * check at out_seq is unnecessary but harmless: */
+		goto out_seq;
+	}
+	/* buf->len is the number of bytes from the original start of the
+	 * request to the end, where head[0].iov_len is just the bytes
+	 * not yet read from the head, so these two values are different: */
+	remaining_len = total_buf_len(buf);
+	if (priv_len > remaining_len)
+		return -EINVAL;
+	pad = remaining_len - priv_len;
+	buf->len -= pad;
+	fix_priv_head(buf, pad);
+
+	/* Maybe it would be better to give gss_unwrap a length parameter: */
+	saved_len = buf->len;
+	buf->len = priv_len;
+	maj_stat = gss_unwrap(ctx, 0, buf);
+	pad = priv_len - buf->len;
+	buf->len = saved_len;
+	buf->len -= pad;
+	/* The upper layers assume the buffer is aligned on 4-byte boundaries.
+	 * In the krb5p case, at least, the data ends up offset, so we need to
+	 * move it around. */
+	/* XXX: This is very inefficient.  It would be better to either do
+	 * this while we encrypt, or maybe in the receive code, if we can peak
+	 * ahead and work out the service and mechanism there. */
+	offset = buf->head[0].iov_len % 4;
+	if (offset) {
+		buf->buflen = RPCSVC_MAXPAYLOAD;
+		xdr_shift_buf(buf, offset);
+		fix_priv_head(buf, pad);
+	}
+	if (maj_stat != GSS_S_COMPLETE)
+		return -EINVAL;
+out_seq:
+	if (svc_getnl(&buf->head[0]) != seq)
+		return -EINVAL;
+	return 0;
+}
+
+struct gss_svc_data {
+	/* decoded gss client cred: */
+	struct rpc_gss_wire_cred	clcred;
+	/* save a pointer to the beginning of the encoded verifier,
+	 * for use in encryption/checksumming in svcauth_gss_release: */
+	__be32				*verf_start;
+	struct rsc			*rsci;
+};
+
+static int
+svcauth_gss_set_client(struct svc_rqst *rqstp)
+{
+	struct gss_svc_data *svcdata = rqstp->rq_auth_data;
+	struct rsc *rsci = svcdata->rsci;
+	struct rpc_gss_wire_cred *gc = &svcdata->clcred;
+	int stat;
+
+	/*
+	 * A gss export can be specified either by:
+	 * 	export	*(sec=krb5,rw)
+	 * or by
+	 * 	export gss/krb5(rw)
+	 * The latter is deprecated; but for backwards compatibility reasons
+	 * the nfsd code will still fall back on trying it if the former
+	 * doesn't work; so we try to make both available to nfsd, below.
+	 */
+	rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
+	if (rqstp->rq_gssclient == NULL)
+		return SVC_DENIED;
+	stat = svcauth_unix_set_client(rqstp);
+	if (stat == SVC_DROP || stat == SVC_CLOSE)
+		return stat;
+	return SVC_OK;
+}
+
+static inline int
+gss_write_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp,
+		struct xdr_netobj *out_handle, int *major_status)
+{
+	struct rsc *rsci;
+	int        rc;
+
+	if (*major_status != GSS_S_COMPLETE)
+		return gss_write_null_verf(rqstp);
+	rsci = gss_svc_searchbyctx(cd, out_handle);
+	if (rsci == NULL) {
+		*major_status = GSS_S_NO_CONTEXT;
+		return gss_write_null_verf(rqstp);
+	}
+	rc = gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN);
+	cache_put(&rsci->h, cd);
+	return rc;
+}
+
+static inline int
+gss_read_common_verf(struct rpc_gss_wire_cred *gc,
+		     struct kvec *argv, __be32 *authp,
+		     struct xdr_netobj *in_handle)
+{
+	/* Read the verifier; should be NULL: */
+	*authp = rpc_autherr_badverf;
+	if (argv->iov_len < 2 * 4)
+		return SVC_DENIED;
+	if (svc_getnl(argv) != RPC_AUTH_NULL)
+		return SVC_DENIED;
+	if (svc_getnl(argv) != 0)
+		return SVC_DENIED;
+	/* Martial context handle and token for upcall: */
+	*authp = rpc_autherr_badcred;
+	if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
+		return SVC_DENIED;
+	if (dup_netobj(in_handle, &gc->gc_ctx))
+		return SVC_CLOSE;
+	*authp = rpc_autherr_badverf;
+
+	return 0;
+}
+
+static inline int
+gss_read_verf(struct rpc_gss_wire_cred *gc,
+	      struct kvec *argv, __be32 *authp,
+	      struct xdr_netobj *in_handle,
+	      struct xdr_netobj *in_token)
+{
+	struct xdr_netobj tmpobj;
+	int res;
+
+	res = gss_read_common_verf(gc, argv, authp, in_handle);
+	if (res)
+		return res;
+
+	if (svc_safe_getnetobj(argv, &tmpobj)) {
+		kfree(in_handle->data);
+		return SVC_DENIED;
+	}
+	if (dup_netobj(in_token, &tmpobj)) {
+		kfree(in_handle->data);
+		return SVC_CLOSE;
+	}
+
+	return 0;
+}
+
+/* Ok this is really heavily depending on a set of semantics in
+ * how rqstp is set up by svc_recv and pages laid down by the
+ * server when reading a request. We are basically guaranteed that
+ * the token lays all down linearly across a set of pages, starting
+ * at iov_base in rq_arg.head[0] which happens to be the first of a
+ * set of pages stored in rq_pages[].
+ * rq_arg.head[0].iov_base will provide us the page_base to pass
+ * to the upcall.
+ */
+static inline int
+gss_read_proxy_verf(struct svc_rqst *rqstp,
+		    struct rpc_gss_wire_cred *gc, __be32 *authp,
+		    struct xdr_netobj *in_handle,
+		    struct gssp_in_token *in_token)
+{
+	struct kvec *argv = &rqstp->rq_arg.head[0];
+	u32 inlen;
+	int res;
+
+	res = gss_read_common_verf(gc, argv, authp, in_handle);
+	if (res)
+		return res;
+
+	inlen = svc_getnl(argv);
+	if (inlen > (argv->iov_len + rqstp->rq_arg.page_len))
+		return SVC_DENIED;
+
+	in_token->pages = rqstp->rq_pages;
+	in_token->page_base = (ulong)argv->iov_base & ~PAGE_MASK;
+	in_token->page_len = inlen;
+
+	return 0;
+}
+
+static inline int
+gss_write_resv(struct kvec *resv, size_t size_limit,
+	       struct xdr_netobj *out_handle, struct xdr_netobj *out_token,
+	       int major_status, int minor_status)
+{
+	if (resv->iov_len + 4 > size_limit)
+		return -1;
+	svc_putnl(resv, RPC_SUCCESS);
+	if (svc_safe_putnetobj(resv, out_handle))
+		return -1;
+	if (resv->iov_len + 3 * 4 > size_limit)
+		return -1;
+	svc_putnl(resv, major_status);
+	svc_putnl(resv, minor_status);
+	svc_putnl(resv, GSS_SEQ_WIN);
+	if (svc_safe_putnetobj(resv, out_token))
+		return -1;
+	return 0;
+}
+
+/*
+ * Having read the cred already and found we're in the context
+ * initiation case, read the verifier and initiate (or check the results
+ * of) upcalls to userspace for help with context initiation.  If
+ * the upcall results are available, write the verifier and result.
+ * Otherwise, drop the request pending an answer to the upcall.
+ */
+static int svcauth_gss_legacy_init(struct svc_rqst *rqstp,
+			struct rpc_gss_wire_cred *gc, __be32 *authp)
+{
+	struct kvec *argv = &rqstp->rq_arg.head[0];
+	struct kvec *resv = &rqstp->rq_res.head[0];
+	struct rsi *rsip, rsikey;
+	int ret;
+	struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
+
+	memset(&rsikey, 0, sizeof(rsikey));
+	ret = gss_read_verf(gc, argv, authp,
+			    &rsikey.in_handle, &rsikey.in_token);
+	if (ret)
+		return ret;
+
+	/* Perform upcall, or find upcall result: */
+	rsip = rsi_lookup(sn->rsi_cache, &rsikey);
+	rsi_free(&rsikey);
+	if (!rsip)
+		return SVC_CLOSE;
+	if (cache_check(sn->rsi_cache, &rsip->h, &rqstp->rq_chandle) < 0)
+		/* No upcall result: */
+		return SVC_CLOSE;
+
+	ret = SVC_CLOSE;
+	/* Got an answer to the upcall; use it: */
+	if (gss_write_init_verf(sn->rsc_cache, rqstp,
+				&rsip->out_handle, &rsip->major_status))
+		goto out;
+	if (gss_write_resv(resv, PAGE_SIZE,
+			   &rsip->out_handle, &rsip->out_token,
+			   rsip->major_status, rsip->minor_status))
+		goto out;
+
+	ret = SVC_COMPLETE;
+out:
+	cache_put(&rsip->h, sn->rsi_cache);
+	return ret;
+}
+
+static int gss_proxy_save_rsc(struct cache_detail *cd,
+				struct gssp_upcall_data *ud,
+				uint64_t *handle)
+{
+	struct rsc rsci, *rscp = NULL;
+	static atomic64_t ctxhctr;
+	long long ctxh;
+	struct gss_api_mech *gm = NULL;
+	time_t expiry;
+	int status = -EINVAL;
+
+	memset(&rsci, 0, sizeof(rsci));
+	/* context handle */
+	status = -ENOMEM;
+	/* the handle needs to be just a unique id,
+	 * use a static counter */
+	ctxh = atomic64_inc_return(&ctxhctr);
+
+	/* make a copy for the caller */
+	*handle = ctxh;
+
+	/* make a copy for the rsc cache */
+	if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t)))
+		goto out;
+	rscp = rsc_lookup(cd, &rsci);
+	if (!rscp)
+		goto out;
+
+	/* creds */
+	if (!ud->found_creds) {
+		/* userspace seem buggy, we should always get at least a
+		 * mapping to nobody */
+		dprintk("RPC:       No creds found!\n");
+		goto out;
+	} else {
+
+		/* steal creds */
+		rsci.cred = ud->creds;
+		memset(&ud->creds, 0, sizeof(struct svc_cred));
+
+		status = -EOPNOTSUPP;
+		/* get mech handle from OID */
+		gm = gss_mech_get_by_OID(&ud->mech_oid);
+		if (!gm)
+			goto out;
+		rsci.cred.cr_gss_mech = gm;
+
+		status = -EINVAL;
+		/* mech-specific data: */
+		status = gss_import_sec_context(ud->out_handle.data,
+						ud->out_handle.len,
+						gm, &rsci.mechctx,
+						&expiry, GFP_KERNEL);
+		if (status)
+			goto out;
+	}
+
+	rsci.h.expiry_time = expiry;
+	rscp = rsc_update(cd, &rsci, rscp);
+	status = 0;
+out:
+	rsc_free(&rsci);
+	if (rscp)
+		cache_put(&rscp->h, cd);
+	else
+		status = -ENOMEM;
+	return status;
+}
+
+static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
+			struct rpc_gss_wire_cred *gc, __be32 *authp)
+{
+	struct kvec *resv = &rqstp->rq_res.head[0];
+	struct xdr_netobj cli_handle;
+	struct gssp_upcall_data ud;
+	uint64_t handle;
+	int status;
+	int ret;
+	struct net *net = rqstp->rq_xprt->xpt_net;
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	memset(&ud, 0, sizeof(ud));
+	ret = gss_read_proxy_verf(rqstp, gc, authp,
+				  &ud.in_handle, &ud.in_token);
+	if (ret)
+		return ret;
+
+	ret = SVC_CLOSE;
+
+	/* Perform synchronous upcall to gss-proxy */
+	status = gssp_accept_sec_context_upcall(net, &ud);
+	if (status)
+		goto out;
+
+	dprintk("RPC:       svcauth_gss: gss major status = %d\n",
+			ud.major_status);
+
+	switch (ud.major_status) {
+	case GSS_S_CONTINUE_NEEDED:
+		cli_handle = ud.out_handle;
+		break;
+	case GSS_S_COMPLETE:
+		status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle);
+		if (status)
+			goto out;
+		cli_handle.data = (u8 *)&handle;
+		cli_handle.len = sizeof(handle);
+		break;
+	default:
+		ret = SVC_CLOSE;
+		goto out;
+	}
+
+	/* Got an answer to the upcall; use it: */
+	if (gss_write_init_verf(sn->rsc_cache, rqstp,
+				&cli_handle, &ud.major_status))
+		goto out;
+	if (gss_write_resv(resv, PAGE_SIZE,
+			   &cli_handle, &ud.out_token,
+			   ud.major_status, ud.minor_status))
+		goto out;
+
+	ret = SVC_COMPLETE;
+out:
+	gssp_free_upcall_data(&ud);
+	return ret;
+}
+
+/*
+ * Try to set the sn->use_gss_proxy variable to a new value. We only allow
+ * it to be changed if it's currently undefined (-1). If it's any other value
+ * then return -EBUSY unless the type wouldn't have changed anyway.
+ */
+static int set_gss_proxy(struct net *net, int type)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	int ret;
+
+	WARN_ON_ONCE(type != 0 && type != 1);
+	ret = cmpxchg(&sn->use_gss_proxy, -1, type);
+	if (ret != -1 && ret != type)
+		return -EBUSY;
+	return 0;
+}
+
+static bool use_gss_proxy(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	/* If use_gss_proxy is still undefined, then try to disable it */
+	if (sn->use_gss_proxy == -1)
+		set_gss_proxy(net, 0);
+	return sn->use_gss_proxy;
+}
+
+#ifdef CONFIG_PROC_FS
+
+static ssize_t write_gssp(struct file *file, const char __user *buf,
+			 size_t count, loff_t *ppos)
+{
+	struct net *net = PDE_DATA(file_inode(file));
+	char tbuf[20];
+	unsigned long i;
+	int res;
+
+	if (*ppos || count > sizeof(tbuf)-1)
+		return -EINVAL;
+	if (copy_from_user(tbuf, buf, count))
+		return -EFAULT;
+
+	tbuf[count] = 0;
+	res = kstrtoul(tbuf, 0, &i);
+	if (res)
+		return res;
+	if (i != 1)
+		return -EINVAL;
+	res = set_gssp_clnt(net);
+	if (res)
+		return res;
+	res = set_gss_proxy(net, 1);
+	if (res)
+		return res;
+	return count;
+}
+
+static ssize_t read_gssp(struct file *file, char __user *buf,
+			 size_t count, loff_t *ppos)
+{
+	struct net *net = PDE_DATA(file_inode(file));
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	unsigned long p = *ppos;
+	char tbuf[10];
+	size_t len;
+
+	snprintf(tbuf, sizeof(tbuf), "%d\n", sn->use_gss_proxy);
+	len = strlen(tbuf);
+	if (p >= len)
+		return 0;
+	len -= p;
+	if (len > count)
+		len = count;
+	if (copy_to_user(buf, (void *)(tbuf+p), len))
+		return -EFAULT;
+	*ppos += len;
+	return len;
+}
+
+static const struct file_operations use_gss_proxy_ops = {
+	.open = nonseekable_open,
+	.write = write_gssp,
+	.read = read_gssp,
+};
+
+static int create_use_gss_proxy_proc_entry(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct proc_dir_entry **p = &sn->use_gssp_proc;
+
+	sn->use_gss_proxy = -1;
+	*p = proc_create_data("use-gss-proxy", S_IFREG|S_IRUSR|S_IWUSR,
+			      sn->proc_net_rpc,
+			      &use_gss_proxy_ops, net);
+	if (!*p)
+		return -ENOMEM;
+	init_gssp_clnt(sn);
+	return 0;
+}
+
+static void destroy_use_gss_proxy_proc_entry(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	if (sn->use_gssp_proc) {
+		remove_proc_entry("use-gss-proxy", sn->proc_net_rpc); 
+		clear_gssp_clnt(sn);
+	}
+}
+#else /* CONFIG_PROC_FS */
+
+static int create_use_gss_proxy_proc_entry(struct net *net)
+{
+	return 0;
+}
+
+static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
+
+#endif /* CONFIG_PROC_FS */
+
+/*
+ * Accept an rpcsec packet.
+ * If context establishment, punt to user space
+ * If data exchange, verify/decrypt
+ * If context destruction, handle here
+ * In the context establishment and destruction case we encode
+ * response here and return SVC_COMPLETE.
+ */
+static int
+svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
+{
+	struct kvec	*argv = &rqstp->rq_arg.head[0];
+	struct kvec	*resv = &rqstp->rq_res.head[0];
+	u32		crlen;
+	struct gss_svc_data *svcdata = rqstp->rq_auth_data;
+	struct rpc_gss_wire_cred *gc;
+	struct rsc	*rsci = NULL;
+	__be32		*rpcstart;
+	__be32		*reject_stat = resv->iov_base + resv->iov_len;
+	int		ret;
+	struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
+
+	dprintk("RPC:       svcauth_gss: argv->iov_len = %zd\n",
+			argv->iov_len);
+
+	*authp = rpc_autherr_badcred;
+	if (!svcdata)
+		svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
+	if (!svcdata)
+		goto auth_err;
+	rqstp->rq_auth_data = svcdata;
+	svcdata->verf_start = NULL;
+	svcdata->rsci = NULL;
+	gc = &svcdata->clcred;
+
+	/* start of rpc packet is 7 u32's back from here:
+	 * xid direction rpcversion prog vers proc flavour
+	 */
+	rpcstart = argv->iov_base;
+	rpcstart -= 7;
+
+	/* credential is:
+	 *   version(==1), proc(0,1,2,3), seq, service (1,2,3), handle
+	 * at least 5 u32s, and is preceded by length, so that makes 6.
+	 */
+
+	if (argv->iov_len < 5 * 4)
+		goto auth_err;
+	crlen = svc_getnl(argv);
+	if (svc_getnl(argv) != RPC_GSS_VERSION)
+		goto auth_err;
+	gc->gc_proc = svc_getnl(argv);
+	gc->gc_seq = svc_getnl(argv);
+	gc->gc_svc = svc_getnl(argv);
+	if (svc_safe_getnetobj(argv, &gc->gc_ctx))
+		goto auth_err;
+	if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4)
+		goto auth_err;
+
+	if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0))
+		goto auth_err;
+
+	*authp = rpc_autherr_badverf;
+	switch (gc->gc_proc) {
+	case RPC_GSS_PROC_INIT:
+	case RPC_GSS_PROC_CONTINUE_INIT:
+		if (use_gss_proxy(SVC_NET(rqstp)))
+			return svcauth_gss_proxy_init(rqstp, gc, authp);
+		else
+			return svcauth_gss_legacy_init(rqstp, gc, authp);
+	case RPC_GSS_PROC_DATA:
+	case RPC_GSS_PROC_DESTROY:
+		/* Look up the context, and check the verifier: */
+		*authp = rpcsec_gsserr_credproblem;
+		rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx);
+		if (!rsci)
+			goto auth_err;
+		switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) {
+		case SVC_OK:
+			break;
+		case SVC_DENIED:
+			goto auth_err;
+		case SVC_DROP:
+			goto drop;
+		}
+		break;
+	default:
+		*authp = rpc_autherr_rejectedcred;
+		goto auth_err;
+	}
+
+	/* now act upon the command: */
+	switch (gc->gc_proc) {
+	case RPC_GSS_PROC_DESTROY:
+		if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
+			goto auth_err;
+		rsci->h.expiry_time = get_seconds();
+		set_bit(CACHE_NEGATIVE, &rsci->h.flags);
+		if (resv->iov_len + 4 > PAGE_SIZE)
+			goto drop;
+		svc_putnl(resv, RPC_SUCCESS);
+		goto complete;
+	case RPC_GSS_PROC_DATA:
+		*authp = rpcsec_gsserr_ctxproblem;
+		svcdata->verf_start = resv->iov_base + resv->iov_len;
+		if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
+			goto auth_err;
+		rqstp->rq_cred = rsci->cred;
+		get_group_info(rsci->cred.cr_group_info);
+		*authp = rpc_autherr_badcred;
+		switch (gc->gc_svc) {
+		case RPC_GSS_SVC_NONE:
+			break;
+		case RPC_GSS_SVC_INTEGRITY:
+			/* placeholders for length and seq. number: */
+			svc_putnl(resv, 0);
+			svc_putnl(resv, 0);
+			if (unwrap_integ_data(rqstp, &rqstp->rq_arg,
+					gc->gc_seq, rsci->mechctx))
+				goto garbage_args;
+			rqstp->rq_auth_slack = RPC_MAX_AUTH_SIZE;
+			break;
+		case RPC_GSS_SVC_PRIVACY:
+			/* placeholders for length and seq. number: */
+			svc_putnl(resv, 0);
+			svc_putnl(resv, 0);
+			if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
+					gc->gc_seq, rsci->mechctx))
+				goto garbage_args;
+			rqstp->rq_auth_slack = RPC_MAX_AUTH_SIZE * 2;
+			break;
+		default:
+			goto auth_err;
+		}
+		svcdata->rsci = rsci;
+		cache_get(&rsci->h);
+		rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor(
+					rsci->mechctx->mech_type,
+					GSS_C_QOP_DEFAULT,
+					gc->gc_svc);
+		ret = SVC_OK;
+		goto out;
+	}
+garbage_args:
+	ret = SVC_GARBAGE;
+	goto out;
+auth_err:
+	/* Restore write pointer to its original value: */
+	xdr_ressize_check(rqstp, reject_stat);
+	ret = SVC_DENIED;
+	goto out;
+complete:
+	ret = SVC_COMPLETE;
+	goto out;
+drop:
+	ret = SVC_DROP;
+out:
+	if (rsci)
+		cache_put(&rsci->h, sn->rsc_cache);
+	return ret;
+}
+
+static __be32 *
+svcauth_gss_prepare_to_wrap(struct xdr_buf *resbuf, struct gss_svc_data *gsd)
+{
+	__be32 *p;
+	u32 verf_len;
+
+	p = gsd->verf_start;
+	gsd->verf_start = NULL;
+
+	/* If the reply stat is nonzero, don't wrap: */
+	if (*(p-1) != rpc_success)
+		return NULL;
+	/* Skip the verifier: */
+	p += 1;
+	verf_len = ntohl(*p++);
+	p += XDR_QUADLEN(verf_len);
+	/* move accept_stat to right place: */
+	memcpy(p, p + 2, 4);
+	/* Also don't wrap if the accept stat is nonzero: */
+	if (*p != rpc_success) {
+		resbuf->head[0].iov_len -= 2 * 4;
+		return NULL;
+	}
+	p++;
+	return p;
+}
+
+static inline int
+svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
+{
+	struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
+	struct rpc_gss_wire_cred *gc = &gsd->clcred;
+	struct xdr_buf *resbuf = &rqstp->rq_res;
+	struct xdr_buf integ_buf;
+	struct xdr_netobj mic;
+	struct kvec *resv;
+	__be32 *p;
+	int integ_offset, integ_len;
+	int stat = -EINVAL;
+
+	p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
+	if (p == NULL)
+		goto out;
+	integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base;
+	integ_len = resbuf->len - integ_offset;
+	BUG_ON(integ_len % 4);
+	*p++ = htonl(integ_len);
+	*p++ = htonl(gc->gc_seq);
+	if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len))
+		BUG();
+	if (resbuf->tail[0].iov_base == NULL) {
+		if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
+			goto out_err;
+		resbuf->tail[0].iov_base = resbuf->head[0].iov_base
+						+ resbuf->head[0].iov_len;
+		resbuf->tail[0].iov_len = 0;
+	}
+	resv = &resbuf->tail[0];
+	mic.data = (u8 *)resv->iov_base + resv->iov_len + 4;
+	if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic))
+		goto out_err;
+	svc_putnl(resv, mic.len);
+	memset(mic.data + mic.len, 0,
+			round_up_to_quad(mic.len) - mic.len);
+	resv->iov_len += XDR_QUADLEN(mic.len) << 2;
+	/* not strictly required: */
+	resbuf->len += XDR_QUADLEN(mic.len) << 2;
+	BUG_ON(resv->iov_len > PAGE_SIZE);
+out:
+	stat = 0;
+out_err:
+	return stat;
+}
+
+static inline int
+svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
+{
+	struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
+	struct rpc_gss_wire_cred *gc = &gsd->clcred;
+	struct xdr_buf *resbuf = &rqstp->rq_res;
+	struct page **inpages = NULL;
+	__be32 *p, *len;
+	int offset;
+	int pad;
+
+	p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
+	if (p == NULL)
+		return 0;
+	len = p++;
+	offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base;
+	*p++ = htonl(gc->gc_seq);
+	inpages = resbuf->pages;
+	/* XXX: Would be better to write some xdr helper functions for
+	 * nfs{2,3,4}xdr.c that place the data right, instead of copying: */
+
+	/*
+	 * If there is currently tail data, make sure there is
+	 * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in
+	 * the page, and move the current tail data such that
+	 * there is RPC_MAX_AUTH_SIZE slack space available in
+	 * both the head and tail.
+	 */
+	if (resbuf->tail[0].iov_base) {
+		BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base
+							+ PAGE_SIZE);
+		BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base);
+		if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len
+				+ 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
+			return -ENOMEM;
+		memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE,
+			resbuf->tail[0].iov_base,
+			resbuf->tail[0].iov_len);
+		resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE;
+	}
+	/*
+	 * If there is no current tail data, make sure there is
+	 * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the
+	 * allotted page, and set up tail information such that there
+	 * is RPC_MAX_AUTH_SIZE slack space available in both the
+	 * head and tail.
+	 */
+	if (resbuf->tail[0].iov_base == NULL) {
+		if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE)
+			return -ENOMEM;
+		resbuf->tail[0].iov_base = resbuf->head[0].iov_base
+			+ resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE;
+		resbuf->tail[0].iov_len = 0;
+	}
+	if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages))
+		return -ENOMEM;
+	*len = htonl(resbuf->len - offset);
+	pad = 3 - ((resbuf->len - offset - 1)&3);
+	p = (__be32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len);
+	memset(p, 0, pad);
+	resbuf->tail[0].iov_len += pad;
+	resbuf->len += pad;
+	return 0;
+}
+
+static int
+svcauth_gss_release(struct svc_rqst *rqstp)
+{
+	struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
+	struct rpc_gss_wire_cred *gc = &gsd->clcred;
+	struct xdr_buf *resbuf = &rqstp->rq_res;
+	int stat = -EINVAL;
+	struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
+
+	if (gc->gc_proc != RPC_GSS_PROC_DATA)
+		goto out;
+	/* Release can be called twice, but we only wrap once. */
+	if (gsd->verf_start == NULL)
+		goto out;
+	/* normally not set till svc_send, but we need it here: */
+	/* XXX: what for?  Do we mess it up the moment we call svc_putu32
+	 * or whatever? */
+	resbuf->len = total_buf_len(resbuf);
+	switch (gc->gc_svc) {
+	case RPC_GSS_SVC_NONE:
+		break;
+	case RPC_GSS_SVC_INTEGRITY:
+		stat = svcauth_gss_wrap_resp_integ(rqstp);
+		if (stat)
+			goto out_err;
+		break;
+	case RPC_GSS_SVC_PRIVACY:
+		stat = svcauth_gss_wrap_resp_priv(rqstp);
+		if (stat)
+			goto out_err;
+		break;
+	/*
+	 * For any other gc_svc value, svcauth_gss_accept() already set
+	 * the auth_error appropriately; just fall through:
+	 */
+	}
+
+out:
+	stat = 0;
+out_err:
+	if (rqstp->rq_client)
+		auth_domain_put(rqstp->rq_client);
+	rqstp->rq_client = NULL;
+	if (rqstp->rq_gssclient)
+		auth_domain_put(rqstp->rq_gssclient);
+	rqstp->rq_gssclient = NULL;
+	if (rqstp->rq_cred.cr_group_info)
+		put_group_info(rqstp->rq_cred.cr_group_info);
+	rqstp->rq_cred.cr_group_info = NULL;
+	if (gsd->rsci)
+		cache_put(&gsd->rsci->h, sn->rsc_cache);
+	gsd->rsci = NULL;
+
+	return stat;
+}
+
+static void
+svcauth_gss_domain_release(struct auth_domain *dom)
+{
+	struct gss_domain *gd = container_of(dom, struct gss_domain, h);
+
+	kfree(dom->name);
+	kfree(gd);
+}
+
+static struct auth_ops svcauthops_gss = {
+	.name		= "rpcsec_gss",
+	.owner		= THIS_MODULE,
+	.flavour	= RPC_AUTH_GSS,
+	.accept		= svcauth_gss_accept,
+	.release	= svcauth_gss_release,
+	.domain_release = svcauth_gss_domain_release,
+	.set_client	= svcauth_gss_set_client,
+};
+
+static int rsi_cache_create_net(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct cache_detail *cd;
+	int err;
+
+	cd = cache_create_net(&rsi_cache_template, net);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+	err = cache_register_net(cd, net);
+	if (err) {
+		cache_destroy_net(cd, net);
+		return err;
+	}
+	sn->rsi_cache = cd;
+	return 0;
+}
+
+static void rsi_cache_destroy_net(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct cache_detail *cd = sn->rsi_cache;
+
+	sn->rsi_cache = NULL;
+	cache_purge(cd);
+	cache_unregister_net(cd, net);
+	cache_destroy_net(cd, net);
+}
+
+static int rsc_cache_create_net(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct cache_detail *cd;
+	int err;
+
+	cd = cache_create_net(&rsc_cache_template, net);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+	err = cache_register_net(cd, net);
+	if (err) {
+		cache_destroy_net(cd, net);
+		return err;
+	}
+	sn->rsc_cache = cd;
+	return 0;
+}
+
+static void rsc_cache_destroy_net(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct cache_detail *cd = sn->rsc_cache;
+
+	sn->rsc_cache = NULL;
+	cache_purge(cd);
+	cache_unregister_net(cd, net);
+	cache_destroy_net(cd, net);
+}
+
+int
+gss_svc_init_net(struct net *net)
+{
+	int rv;
+
+	rv = rsc_cache_create_net(net);
+	if (rv)
+		return rv;
+	rv = rsi_cache_create_net(net);
+	if (rv)
+		goto out1;
+	rv = create_use_gss_proxy_proc_entry(net);
+	if (rv)
+		goto out2;
+	return 0;
+out2:
+	destroy_use_gss_proxy_proc_entry(net);
+out1:
+	rsc_cache_destroy_net(net);
+	return rv;
+}
+
+void
+gss_svc_shutdown_net(struct net *net)
+{
+	destroy_use_gss_proxy_proc_entry(net);
+	rsi_cache_destroy_net(net);
+	rsc_cache_destroy_net(net);
+}
+
+int
+gss_svc_init(void)
+{
+	return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
+}
+
+void
+gss_svc_shutdown(void)
+{
+	svc_auth_unregister(RPC_AUTH_GSS);
+}