From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- fs/nfs/callback.c | 499 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 499 insertions(+) create mode 100644 fs/nfs/callback.c (limited to 'fs/nfs/callback.c') diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c new file mode 100644 index 000000000..8d129bb73 --- /dev/null +++ b/fs/nfs/callback.c @@ -0,0 +1,499 @@ +/* + * linux/fs/nfs/callback.c + * + * Copyright (C) 2004 Trond Myklebust + * + * NFSv4 callback handling + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "nfs4_fs.h" +#include "callback.h" +#include "internal.h" +#include "netns.h" + +#define NFSDBG_FACILITY NFSDBG_CALLBACK + +struct nfs_callback_data { + unsigned int users; + struct svc_serv *serv; + struct svc_rqst *rqst; + struct task_struct *task; +}; + +static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1]; +static DEFINE_MUTEX(nfs_callback_mutex); +static struct svc_program nfs4_callback_program; + +static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net) +{ + int ret; + struct nfs_net *nn = net_generic(net, nfs_net_id); + + ret = svc_create_xprt(serv, "tcp", net, PF_INET, + nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS); + if (ret <= 0) + goto out_err; + nn->nfs_callback_tcpport = ret; + dprintk("NFS: Callback listener port = %u (af %u, net %p)\n", + nn->nfs_callback_tcpport, PF_INET, net); + + ret = svc_create_xprt(serv, "tcp", net, PF_INET6, + nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS); + if (ret > 0) { + nn->nfs_callback_tcpport6 = ret; + dprintk("NFS: Callback listener port = %u (af %u, net %p)\n", + nn->nfs_callback_tcpport6, PF_INET6, net); + } else if (ret != -EAFNOSUPPORT) + goto out_err; + return 0; + +out_err: + return (ret) ? ret : -ENOMEM; +} + +/* + * This is the NFSv4 callback kernel thread. + */ +static int +nfs4_callback_svc(void *vrqstp) +{ + int err; + struct svc_rqst *rqstp = vrqstp; + + set_freezable(); + + while (!kthread_should_stop()) { + /* + * Listen for a request on the socket + */ + err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT); + if (err == -EAGAIN || err == -EINTR) + continue; + svc_process(rqstp); + } + return 0; +} + +/* + * Prepare to bring up the NFSv4 callback service + */ +static struct svc_rqst * +nfs4_callback_up(struct svc_serv *serv) +{ + return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE); +} + +#if defined(CONFIG_NFS_V4_1) +static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net) +{ + /* + * Create an svc_sock for the back channel service that shares the + * fore channel connection. + * Returns the input port (0) and sets the svc_serv bc_xprt on success + */ + return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0, + SVC_SOCK_ANONYMOUS); +} + +/* + * The callback service for NFSv4.1 callbacks + */ +static int +nfs41_callback_svc(void *vrqstp) +{ + struct svc_rqst *rqstp = vrqstp; + struct svc_serv *serv = rqstp->rq_server; + struct rpc_rqst *req; + int error; + DEFINE_WAIT(wq); + + set_freezable(); + + while (!kthread_should_stop()) { + if (try_to_freeze()) + continue; + + prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE); + spin_lock_bh(&serv->sv_cb_lock); + if (!list_empty(&serv->sv_cb_list)) { + req = list_first_entry(&serv->sv_cb_list, + struct rpc_rqst, rq_bc_list); + list_del(&req->rq_bc_list); + spin_unlock_bh(&serv->sv_cb_lock); + finish_wait(&serv->sv_cb_waitq, &wq); + dprintk("Invoking bc_svc_process()\n"); + error = bc_svc_process(serv, req, rqstp); + dprintk("bc_svc_process() returned w/ error code= %d\n", + error); + } else { + spin_unlock_bh(&serv->sv_cb_lock); + schedule(); + finish_wait(&serv->sv_cb_waitq, &wq); + } + flush_signals(current); + } + return 0; +} + +/* + * Bring up the NFSv4.1 callback service + */ +static struct svc_rqst * +nfs41_callback_up(struct svc_serv *serv) +{ + struct svc_rqst *rqstp; + + INIT_LIST_HEAD(&serv->sv_cb_list); + spin_lock_init(&serv->sv_cb_lock); + init_waitqueue_head(&serv->sv_cb_waitq); + rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE); + if (IS_ERR(rqstp)) { + svc_xprt_put(serv->sv_bc_xprt); + serv->sv_bc_xprt = NULL; + } + dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp)); + return rqstp; +} + +static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv, + struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp)) +{ + *rqstpp = nfs41_callback_up(serv); + *callback_svc = nfs41_callback_svc; +} + +static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, + struct svc_serv *serv) +{ + if (minorversion) + /* + * Save the svc_serv in the transport so that it can + * be referenced when the session backchannel is initialized + */ + xprt->bc_serv = serv; +} +#else +static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net) +{ + return 0; +} + +static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv, + struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp)) +{ + *rqstpp = ERR_PTR(-ENOTSUPP); + *callback_svc = ERR_PTR(-ENOTSUPP); +} + +static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, + struct svc_serv *serv) +{ +} +#endif /* CONFIG_NFS_V4_1 */ + +static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt, + struct svc_serv *serv) +{ + struct svc_rqst *rqstp; + int (*callback_svc)(void *vrqstp); + struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; + int ret; + + nfs_callback_bc_serv(minorversion, xprt, serv); + + if (cb_info->task) + return 0; + + switch (minorversion) { + case 0: + /* v4.0 callback setup */ + rqstp = nfs4_callback_up(serv); + callback_svc = nfs4_callback_svc; + break; + default: + nfs_minorversion_callback_svc_setup(serv, + &rqstp, &callback_svc); + } + + if (IS_ERR(rqstp)) + return PTR_ERR(rqstp); + + svc_sock_update_bufs(serv); + + cb_info->serv = serv; + cb_info->rqst = rqstp; + cb_info->task = kthread_create(callback_svc, cb_info->rqst, + "nfsv4.%u-svc", minorversion); + if (IS_ERR(cb_info->task)) { + ret = PTR_ERR(cb_info->task); + svc_exit_thread(cb_info->rqst); + cb_info->rqst = NULL; + cb_info->task = NULL; + return ret; + } + rqstp->rq_task = cb_info->task; + wake_up_process(cb_info->task); + dprintk("nfs_callback_up: service started\n"); + return 0; +} + +static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net) +{ + struct nfs_net *nn = net_generic(net, nfs_net_id); + + if (--nn->cb_users[minorversion]) + return; + + dprintk("NFS: destroy per-net callback data; net=%p\n", net); + svc_shutdown_net(serv, net); +} + +static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net) +{ + struct nfs_net *nn = net_generic(net, nfs_net_id); + int ret; + + if (nn->cb_users[minorversion]++) + return 0; + + dprintk("NFS: create per-net callback data; net=%p\n", net); + + ret = svc_bind(serv, net); + if (ret < 0) { + printk(KERN_WARNING "NFS: bind callback service failed\n"); + goto err_bind; + } + + switch (minorversion) { + case 0: + ret = nfs4_callback_up_net(serv, net); + break; + case 1: + case 2: + ret = nfs41_callback_up_net(serv, net); + break; + default: + printk(KERN_ERR "NFS: unknown callback version: %d\n", + minorversion); + ret = -EINVAL; + break; + } + + if (ret < 0) { + printk(KERN_ERR "NFS: callback service start failed\n"); + goto err_socks; + } + return 0; + +err_socks: + svc_rpcb_cleanup(serv, net); +err_bind: + dprintk("NFS: Couldn't create callback socket: err = %d; " + "net = %p\n", ret, net); + return ret; +} + +static struct svc_serv *nfs_callback_create_svc(int minorversion) +{ + struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; + struct svc_serv *serv; + + /* + * Check whether we're already up and running. + */ + if (cb_info->task) { + /* + * Note: increase service usage, because later in case of error + * svc_destroy() will be called. + */ + svc_get(cb_info->serv); + return cb_info->serv; + } + + /* + * Sanity check: if there's no task, + * we should be the first user ... + */ + if (cb_info->users) + printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n", + cb_info->users); + + serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL); + if (!serv) { + printk(KERN_ERR "nfs_callback_create_svc: create service failed\n"); + return ERR_PTR(-ENOMEM); + } + /* As there is only one thread we need to over-ride the + * default maximum of 80 connections + */ + serv->sv_maxconn = 1024; + dprintk("nfs_callback_create_svc: service created\n"); + return serv; +} + +/* + * Bring up the callback thread if it is not already up. + */ +int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt) +{ + struct svc_serv *serv; + struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; + int ret; + struct net *net = xprt->xprt_net; + + mutex_lock(&nfs_callback_mutex); + + serv = nfs_callback_create_svc(minorversion); + if (IS_ERR(serv)) { + ret = PTR_ERR(serv); + goto err_create; + } + + ret = nfs_callback_up_net(minorversion, serv, net); + if (ret < 0) + goto err_net; + + ret = nfs_callback_start_svc(minorversion, xprt, serv); + if (ret < 0) + goto err_start; + + cb_info->users++; + /* + * svc_create creates the svc_serv with sv_nrthreads == 1, and then + * svc_prepare_thread increments that. So we need to call svc_destroy + * on both success and failure so that the refcount is 1 when the + * thread exits. + */ +err_net: + svc_destroy(serv); +err_create: + mutex_unlock(&nfs_callback_mutex); + return ret; + +err_start: + nfs_callback_down_net(minorversion, serv, net); + dprintk("NFS: Couldn't create server thread; err = %d\n", ret); + goto err_net; +} + +/* + * Kill the callback thread if it's no longer being used. + */ +void nfs_callback_down(int minorversion, struct net *net) +{ + struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; + + mutex_lock(&nfs_callback_mutex); + nfs_callback_down_net(minorversion, cb_info->serv, net); + cb_info->users--; + if (cb_info->users == 0 && cb_info->task != NULL) { + kthread_stop(cb_info->task); + dprintk("nfs_callback_down: service stopped\n"); + svc_exit_thread(cb_info->rqst); + dprintk("nfs_callback_down: service destroyed\n"); + cb_info->serv = NULL; + cb_info->rqst = NULL; + cb_info->task = NULL; + } + mutex_unlock(&nfs_callback_mutex); +} + +/* Boolean check of RPC_AUTH_GSS principal */ +int +check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp) +{ + char *p = rqstp->rq_cred.cr_principal; + + if (rqstp->rq_authop->flavour != RPC_AUTH_GSS) + return 1; + + /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */ + if (clp->cl_minorversion != 0) + return 0; + /* + * It might just be a normal user principal, in which case + * userspace won't bother to tell us the name at all. + */ + if (p == NULL) + return 0; + + /* + * Did we get the acceptor from userland during the SETCLIENID + * negotiation? + */ + if (clp->cl_acceptor) + return !strcmp(p, clp->cl_acceptor); + + /* + * Otherwise try to verify it using the cl_hostname. Note that this + * doesn't work if a non-canonical hostname was used in the devname. + */ + + /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */ + + if (memcmp(p, "nfs@", 4) != 0) + return 0; + p += 4; + if (strcmp(p, clp->cl_hostname) != 0) + return 0; + return 1; +} + +/* + * pg_authenticate method for nfsv4 callback threads. + * + * The authflavor has been negotiated, so an incorrect flavor is a server + * bug. Drop packets with incorrect authflavor. + * + * All other checking done after NFS decoding where the nfs_client can be + * found in nfs4_callback_compound + */ +static int nfs_callback_authenticate(struct svc_rqst *rqstp) +{ + switch (rqstp->rq_authop->flavour) { + case RPC_AUTH_NULL: + if (rqstp->rq_proc != CB_NULL) + return SVC_DROP; + break; + case RPC_AUTH_GSS: + /* No RPC_AUTH_GSS support yet in NFSv4.1 */ + if (svc_is_backchannel(rqstp)) + return SVC_DROP; + } + return SVC_OK; +} + +/* + * Define NFS4 callback program + */ +static struct svc_version *nfs4_callback_version[] = { + [1] = &nfs4_callback_version1, + [4] = &nfs4_callback_version4, +}; + +static struct svc_stat nfs4_callback_stats; + +static struct svc_program nfs4_callback_program = { + .pg_prog = NFS4_CALLBACK, /* RPC service number */ + .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */ + .pg_vers = nfs4_callback_version, /* version table */ + .pg_name = "NFSv4 callback", /* service name */ + .pg_class = "nfs", /* authentication class */ + .pg_stats = &nfs4_callback_stats, + .pg_authenticate = nfs_callback_authenticate, +}; -- cgit v1.2.3