2 * linux/fs/nfs/callback.c
4 * Copyright (C) 2004 Trond Myklebust
6 * NFSv4 callback handling
9 #include <linux/completion.h>
11 #include <linux/module.h>
12 #include <linux/sunrpc/svc.h>
13 #include <linux/sunrpc/svcsock.h>
14 #include <linux/nfs_fs.h>
15 #include <linux/mutex.h>
16 #include <linux/freezer.h>
17 #include <linux/kthread.h>
18 #include <linux/sunrpc/svcauth_gss.h>
19 #include <linux/sunrpc/bc_xprt.h>
21 #include <net/inet_sock.h>
28 #define NFSDBG_FACILITY NFSDBG_CALLBACK
30 struct nfs_callback_data {
32 struct svc_serv *serv;
33 struct svc_rqst *rqst;
34 struct task_struct *task;
37 static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
38 static DEFINE_MUTEX(nfs_callback_mutex);
39 static struct svc_program nfs4_callback_program;
41 static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
44 struct nfs_net *nn = net_generic(net, nfs_net_id);
46 ret = svc_create_xprt(serv, "tcp", net, PF_INET,
47 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
50 nn->nfs_callback_tcpport = ret;
51 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
52 nn->nfs_callback_tcpport, PF_INET, net);
54 ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
55 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
57 nn->nfs_callback_tcpport6 = ret;
58 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
59 nn->nfs_callback_tcpport6, PF_INET6, net);
60 } else if (ret != -EAFNOSUPPORT)
65 return (ret) ? ret : -ENOMEM;
69 * This is the NFSv4 callback kernel thread.
72 nfs4_callback_svc(void *vrqstp)
75 struct svc_rqst *rqstp = vrqstp;
79 while (!kthread_should_stop()) {
81 * Listen for a request on the socket
83 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
84 if (err == -EAGAIN || err == -EINTR) {
90 printk(KERN_WARNING "NFS: %s: unexpected error "
91 "from svc_recv (%d)\n", __func__, err);
94 schedule_timeout_uninterruptible(HZ);
104 * Prepare to bring up the NFSv4 callback service
106 static struct svc_rqst *
107 nfs4_callback_up(struct svc_serv *serv)
109 return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
112 #if defined(CONFIG_NFS_V4_1)
113 static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
116 * Create an svc_sock for the back channel service that shares the
117 * fore channel connection.
118 * Returns the input port (0) and sets the svc_serv bc_xprt on success
120 return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
125 * The callback service for NFSv4.1 callbacks
128 nfs41_callback_svc(void *vrqstp)
130 struct svc_rqst *rqstp = vrqstp;
131 struct svc_serv *serv = rqstp->rq_server;
132 struct rpc_rqst *req;
138 while (!kthread_should_stop()) {
139 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
140 spin_lock_bh(&serv->sv_cb_lock);
141 if (!list_empty(&serv->sv_cb_list)) {
142 req = list_first_entry(&serv->sv_cb_list,
143 struct rpc_rqst, rq_bc_list);
144 list_del(&req->rq_bc_list);
145 spin_unlock_bh(&serv->sv_cb_lock);
146 dprintk("Invoking bc_svc_process()\n");
147 error = bc_svc_process(serv, req, rqstp);
148 dprintk("bc_svc_process() returned w/ error code= %d\n",
151 spin_unlock_bh(&serv->sv_cb_lock);
154 finish_wait(&serv->sv_cb_waitq, &wq);
160 * Bring up the NFSv4.1 callback service
162 static struct svc_rqst *
163 nfs41_callback_up(struct svc_serv *serv)
165 struct svc_rqst *rqstp;
167 INIT_LIST_HEAD(&serv->sv_cb_list);
168 spin_lock_init(&serv->sv_cb_lock);
169 init_waitqueue_head(&serv->sv_cb_waitq);
170 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
172 svc_xprt_put(serv->sv_bc_xprt);
173 serv->sv_bc_xprt = NULL;
175 dprintk("--> %s return %ld\n", __func__,
176 IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
180 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
181 struct svc_serv *serv,
182 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
185 *rqstpp = nfs41_callback_up(serv);
186 *callback_svc = nfs41_callback_svc;
191 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
192 struct svc_serv *serv)
196 * Save the svc_serv in the transport so that it can
197 * be referenced when the session backchannel is initialized
199 xprt->bc_serv = serv;
202 static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
207 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
208 struct svc_serv *serv,
209 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
214 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
215 struct svc_serv *serv)
218 #endif /* CONFIG_NFS_V4_1 */
220 static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
221 struct svc_serv *serv)
223 struct svc_rqst *rqstp;
224 int (*callback_svc)(void *vrqstp);
225 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
228 int minorversion_setup;
230 nfs_callback_bc_serv(minorversion, xprt, serv);
235 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
236 serv, &rqstp, &callback_svc);
237 if (!minorversion_setup) {
238 /* v4.0 callback setup */
239 rqstp = nfs4_callback_up(serv);
240 callback_svc = nfs4_callback_svc;
244 return PTR_ERR(rqstp);
246 svc_sock_update_bufs(serv);
248 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
249 cb_info->serv = serv;
250 cb_info->rqst = rqstp;
251 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
252 if (IS_ERR(cb_info->task)) {
253 ret = PTR_ERR(cb_info->task);
254 svc_exit_thread(cb_info->rqst);
255 cb_info->rqst = NULL;
256 cb_info->task = NULL;
257 return PTR_ERR(cb_info->task);
259 dprintk("nfs_callback_up: service started\n");
263 static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net)
267 dprintk("NFS: create per-net callback data; net=%p\n", net);
269 ret = svc_bind(serv, net);
271 printk(KERN_WARNING "NFS: bind callback service failed\n");
275 switch (minorversion) {
277 ret = nfs4_callback_up_net(serv, net);
280 ret = nfs41_callback_up_net(serv, net);
283 printk(KERN_ERR "NFS: unknown callback version: %d\n",
290 printk(KERN_ERR "NFS: callback service start failed\n");
296 svc_rpcb_cleanup(serv, net);
298 dprintk("NFS: Couldn't create callback socket: err = %d; "
299 "net = %p\n", ret, net);
303 static struct svc_serv *nfs_callback_create_svc(int minorversion)
305 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
306 struct svc_serv *serv;
309 * Check whether we're already up and running.
313 * Note: increase service usage, because later in case of error
314 * svc_destroy() will be called.
316 svc_get(cb_info->serv);
317 return cb_info->serv;
321 * Sanity check: if there's no task,
322 * we should be the first user ...
325 printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
328 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
330 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
331 return ERR_PTR(-ENOMEM);
333 /* As there is only one thread we need to over-ride the
334 * default maximum of 80 connections
336 serv->sv_maxconn = 1024;
337 dprintk("nfs_callback_create_svc: service created\n");
342 * Bring up the callback thread if it is not already up.
344 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
346 struct svc_serv *serv;
347 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
349 struct net *net = xprt->xprt_net;
351 mutex_lock(&nfs_callback_mutex);
353 serv = nfs_callback_create_svc(minorversion);
359 ret = nfs_callback_up_net(minorversion, serv, net);
363 ret = nfs_callback_start_svc(minorversion, xprt, serv);
369 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
370 * svc_prepare_thread increments that. So we need to call svc_destroy
371 * on both success and failure so that the refcount is 1 when the
377 mutex_unlock(&nfs_callback_mutex);
381 svc_shutdown_net(serv, net);
382 dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
387 * Kill the callback thread if it's no longer being used.
389 void nfs_callback_down(int minorversion, struct net *net)
391 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
393 mutex_lock(&nfs_callback_mutex);
395 if (cb_info->users == 0 && cb_info->task != NULL) {
396 kthread_stop(cb_info->task);
397 svc_shutdown_net(cb_info->serv, net);
398 svc_exit_thread(cb_info->rqst);
399 cb_info->serv = NULL;
400 cb_info->rqst = NULL;
401 cb_info->task = NULL;
403 mutex_unlock(&nfs_callback_mutex);
406 /* Boolean check of RPC_AUTH_GSS principal */
408 check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
410 char *p = rqstp->rq_cred.cr_principal;
412 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
415 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
416 if (clp->cl_minorversion != 0)
419 * It might just be a normal user principal, in which case
420 * userspace won't bother to tell us the name at all.
425 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
427 if (memcmp(p, "nfs@", 4) != 0)
430 if (strcmp(p, clp->cl_hostname) != 0)
436 * pg_authenticate method for nfsv4 callback threads.
438 * The authflavor has been negotiated, so an incorrect flavor is a server
439 * bug. Drop packets with incorrect authflavor.
441 * All other checking done after NFS decoding where the nfs_client can be
442 * found in nfs4_callback_compound
444 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
446 switch (rqstp->rq_authop->flavour) {
448 if (rqstp->rq_proc != CB_NULL)
452 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
453 if (svc_is_backchannel(rqstp))
460 * Define NFS4 callback program
462 static struct svc_version *nfs4_callback_version[] = {
463 [1] = &nfs4_callback_version1,
464 [4] = &nfs4_callback_version4,
467 static struct svc_stat nfs4_callback_stats;
469 static struct svc_program nfs4_callback_program = {
470 .pg_prog = NFS4_CALLBACK, /* RPC service number */
471 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
472 .pg_vers = nfs4_callback_version, /* version table */
473 .pg_name = "NFSv4 callback", /* service name */
474 .pg_class = "nfs", /* authentication class */
475 .pg_stats = &nfs4_callback_stats,
476 .pg_authenticate = nfs_callback_authenticate,