1 files changed, 290 insertions, 0 deletions
diff --git a/net/sunrpc/auth_generic.c b/net/sunrpc/auth_generic.c
new file mode 100644
index 000000000..41248b182
--- /dev/null
+++ b/net/sunrpc/auth_generic.c
@@ -0,0 +1,290 @@
+/*
+ * Generic RPC credential
+ *
+ * Copyright (C) 2008, Trond Myklebust <Trond.Myklebust@netapp.com>
+ */
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sunrpc/auth.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/debug.h>
+#include <linux/sunrpc/sched.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_AUTH
+#endif
+
+#define RPC_MACHINE_CRED_USERID		GLOBAL_ROOT_UID
+#define RPC_MACHINE_CRED_GROUPID	GLOBAL_ROOT_GID
+
+struct generic_cred {
+	struct rpc_cred gc_base;
+	struct auth_cred acred;
+};
+
+static struct rpc_auth generic_auth;
+static const struct rpc_credops generic_credops;
+
+/*
+ * Public call interface
+ */
+struct rpc_cred *rpc_lookup_cred(void)
+{
+	return rpcauth_lookupcred(&generic_auth, 0);
+}
+EXPORT_SYMBOL_GPL(rpc_lookup_cred);
+
+struct rpc_cred *rpc_lookup_cred_nonblock(void)
+{
+	return rpcauth_lookupcred(&generic_auth, RPCAUTH_LOOKUP_RCU);
+}
+EXPORT_SYMBOL_GPL(rpc_lookup_cred_nonblock);
+
+/*
+ * Public call interface for looking up machine creds.
+ */
+struct rpc_cred *rpc_lookup_machine_cred(const char *service_name)
+{
+	struct auth_cred acred = {
+		.uid = RPC_MACHINE_CRED_USERID,
+		.gid = RPC_MACHINE_CRED_GROUPID,
+		.principal = service_name,
+		.machine_cred = 1,
+	};
+
+	dprintk("RPC:       looking up machine cred for service %s\n",
+			service_name);
+	return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
+}
+EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred);
+
+static struct rpc_cred *generic_bind_cred(struct rpc_task *task,
+		struct rpc_cred *cred, int lookupflags)
+{
+	struct rpc_auth *auth = task->tk_client->cl_auth;
+	struct auth_cred *acred = &container_of(cred, struct generic_cred, gc_base)->acred;
+
+	return auth->au_ops->lookup_cred(auth, acred, lookupflags);
+}
+
+/*
+ * Lookup generic creds for current process
+ */
+static struct rpc_cred *
+generic_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
+{
+	return rpcauth_lookup_credcache(&generic_auth, acred, flags);
+}
+
+static struct rpc_cred *
+generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
+{
+	struct generic_cred *gcred;
+
+	gcred = kmalloc(sizeof(*gcred), GFP_KERNEL);
+	if (gcred == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops);
+	gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
+
+	gcred->acred.uid = acred->uid;
+	gcred->acred.gid = acred->gid;
+	gcred->acred.group_info = acred->group_info;
+	gcred->acred.ac_flags = 0;
+	if (gcred->acred.group_info != NULL)
+		get_group_info(gcred->acred.group_info);
+	gcred->acred.machine_cred = acred->machine_cred;
+	gcred->acred.principal = acred->principal;
+
+	dprintk("RPC:       allocated %s cred %p for uid %d gid %d\n",
+			gcred->acred.machine_cred ? "machine" : "generic",
+			gcred,
+			from_kuid(&init_user_ns, acred->uid),
+			from_kgid(&init_user_ns, acred->gid));
+	return &gcred->gc_base;
+}
+
+static void
+generic_free_cred(struct rpc_cred *cred)
+{
+	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
+
+	dprintk("RPC:       generic_free_cred %p\n", gcred);
+	if (gcred->acred.group_info != NULL)
+		put_group_info(gcred->acred.group_info);
+	kfree(gcred);
+}
+
+static void
+generic_free_cred_callback(struct rcu_head *head)
+{
+	struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu);
+	generic_free_cred(cred);
+}
+
+static void
+generic_destroy_cred(struct rpc_cred *cred)
+{
+	call_rcu(&cred->cr_rcu, generic_free_cred_callback);
+}
+
+static int
+machine_cred_match(struct auth_cred *acred, struct generic_cred *gcred, int flags)
+{
+	if (!gcred->acred.machine_cred ||
+	    gcred->acred.principal != acred->principal ||
+	    !uid_eq(gcred->acred.uid, acred->uid) ||
+	    !gid_eq(gcred->acred.gid, acred->gid))
+		return 0;
+	return 1;
+}
+
+/*
+ * Match credentials against current process creds.
+ */
+static int
+generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
+{
+	struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
+	int i;
+
+	if (acred->machine_cred)
+		return machine_cred_match(acred, gcred, flags);
+
+	if (!uid_eq(gcred->acred.uid, acred->uid) ||
+	    !gid_eq(gcred->acred.gid, acred->gid) ||
+	    gcred->acred.machine_cred != 0)
+		goto out_nomatch;
+
+	/* Optimisation in the case where pointers are identical... */
+	if (gcred->acred.group_info == acred->group_info)
+		goto out_match;
+
+	/* Slow path... */
+	if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
+		goto out_nomatch;
+	for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
+		if (!gid_eq(GROUP_AT(gcred->acred.group_info, i),
+				GROUP_AT(acred->group_info, i)))
+			goto out_nomatch;
+	}
+out_match:
+	return 1;
+out_nomatch:
+	return 0;
+}
+
+int __init rpc_init_generic_auth(void)
+{
+	return rpcauth_init_credcache(&generic_auth);
+}
+
+void rpc_destroy_generic_auth(void)
+{
+	rpcauth_destroy_credcache(&generic_auth);
+}
+
+/*
+ * Test the the current time (now) against the underlying credential key expiry
+ * minus a timeout and setup notification.
+ *
+ * The normal case:
+ * If 'now' is before the key expiry minus RPC_KEY_EXPIRE_TIMEO, set
+ * the RPC_CRED_NOTIFY_TIMEOUT flag to setup the underlying credential
+ * rpc_credops crmatch routine to notify this generic cred when it's key
+ * expiration is within RPC_KEY_EXPIRE_TIMEO, and return 0.
+ *
+ * The error case:
+ * If the underlying cred lookup fails, return -EACCES.
+ *
+ * The 'almost' error case:
+ * If 'now' is within key expiry minus RPC_KEY_EXPIRE_TIMEO, but not within
+ * key expiry minus RPC_KEY_EXPIRE_FAIL, set the RPC_CRED_EXPIRE_SOON bit
+ * on the acred ac_flags and return 0.
+ */
+static int
+generic_key_timeout(struct rpc_auth *auth, struct rpc_cred *cred)
+{
+	struct auth_cred *acred = &container_of(cred, struct generic_cred,
+						gc_base)->acred;
+	struct rpc_cred *tcred;
+	int ret = 0;
+
+
+	/* Fast track for non crkey_timeout (no key) underlying credentials */
+	if (test_bit(RPC_CRED_NO_CRKEY_TIMEOUT, &acred->ac_flags))
+		return 0;
+
+	/* Fast track for the normal case */
+	if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags))
+		return 0;
+
+	/* lookup_cred either returns a valid referenced rpc_cred, or PTR_ERR */
+	tcred = auth->au_ops->lookup_cred(auth, acred, 0);
+	if (IS_ERR(tcred))
+		return -EACCES;
+
+	if (!tcred->cr_ops->crkey_timeout) {
+		set_bit(RPC_CRED_NO_CRKEY_TIMEOUT, &acred->ac_flags);
+		ret = 0;
+		goto out_put;
+	}
+
+	/* Test for the almost error case */
+	ret = tcred->cr_ops->crkey_timeout(tcred);
+	if (ret != 0) {
+		set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
+		ret = 0;
+	} else {
+		/* In case underlying cred key has been reset */
+		if (test_and_clear_bit(RPC_CRED_KEY_EXPIRE_SOON,
+					&acred->ac_flags))
+			dprintk("RPC:        UID %d Credential key reset\n",
+				from_kuid(&init_user_ns, tcred->cr_uid));
+		/* set up fasttrack for the normal case */
+		set_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
+	}
+
+out_put:
+	put_rpccred(tcred);
+	return ret;
+}
+
+static const struct rpc_authops generic_auth_ops = {
+	.owner = THIS_MODULE,
+	.au_name = "Generic",
+	.lookup_cred = generic_lookup_cred,
+	.crcreate = generic_create_cred,
+	.key_timeout = generic_key_timeout,
+};
+
+static struct rpc_auth generic_auth = {
+	.au_ops = &generic_auth_ops,
+	.au_count = ATOMIC_INIT(0),
+};
+
+static bool generic_key_to_expire(struct rpc_cred *cred)
+{
+	struct auth_cred *acred = &container_of(cred, struct generic_cred,
+						gc_base)->acred;
+	bool ret;
+
+	get_rpccred(cred);
+	ret = test_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
+	put_rpccred(cred);
+
+	return ret;
+}
+
+static const struct rpc_credops generic_credops = {
+	.cr_name = "Generic cred",
+	.crdestroy = generic_destroy_cred,
+	.crbind = generic_bind_cred,
+	.crmatch = generic_match,
+	.crkey_to_expire = generic_key_to_expire,
+};