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>
27 #define NFSDBG_FACILITY NFSDBG_CALLBACK
29 struct nfs_callback_data {
31 struct svc_serv *serv;
32 struct svc_rqst *rqst;
33 struct task_struct *task;
36 static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
37 static DEFINE_MUTEX(nfs_callback_mutex);
38 static struct svc_program nfs4_callback_program;
40 unsigned short nfs_callback_tcpport6;
42 static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
46 ret = svc_create_xprt(serv, "tcp", net, PF_INET,
47 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
50 nfs_callback_tcpport = ret;
51 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
52 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 nfs_callback_tcpport6 = ret;
58 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
59 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, struct rpc_xprt *xprt)
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, struct rpc_xprt *xprt)
165 struct svc_rqst *rqstp;
168 * Save the svc_serv in the transport so that it can
169 * be referenced when the session backchannel is initialized
171 xprt->bc_serv = serv;
173 INIT_LIST_HEAD(&serv->sv_cb_list);
174 spin_lock_init(&serv->sv_cb_lock);
175 init_waitqueue_head(&serv->sv_cb_waitq);
176 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
178 svc_xprt_put(serv->sv_bc_xprt);
179 serv->sv_bc_xprt = NULL;
181 dprintk("--> %s return %ld\n", __func__,
182 IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
186 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
187 struct svc_serv *serv, struct rpc_xprt *xprt,
188 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
191 *rqstpp = nfs41_callback_up(serv, xprt);
192 *callback_svc = nfs41_callback_svc;
197 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
198 struct nfs_callback_data *cb_info)
201 xprt->bc_serv = cb_info->serv;
204 static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
209 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
210 struct svc_serv *serv, struct rpc_xprt *xprt,
211 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
216 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
217 struct nfs_callback_data *cb_info)
220 #endif /* CONFIG_NFS_V4_1 */
222 static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net)
226 dprintk("NFS: create per-net callback data; net=%p\n", net);
228 ret = svc_bind(serv, net);
230 printk(KERN_WARNING "NFS: bind callback service failed\n");
234 switch (minorversion) {
236 ret = nfs4_callback_up_net(serv, net);
239 ret = nfs41_callback_up_net(serv, net);
242 printk(KERN_ERR "NFS: unknown callback version: %d\n",
249 printk(KERN_ERR "NFS: callback service start failed\n");
255 svc_rpcb_cleanup(serv, net);
260 static struct svc_serv *nfs_callback_create_svc(int minorversion)
262 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
263 struct svc_serv *serv;
266 * Check whether we're already up and running.
270 * Note: increase service usage, because later in case of error
271 * svc_destroy() will be called.
273 svc_get(cb_info->serv);
274 return cb_info->serv;
278 * Sanity check: if there's no task,
279 * we should be the first user ...
282 printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
285 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
287 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
288 return ERR_PTR(-ENOMEM);
290 /* As there is only one thread we need to over-ride the
291 * default maximum of 80 connections
293 serv->sv_maxconn = 1024;
294 dprintk("nfs_callback_create_svc: service created\n");
299 * Bring up the callback thread if it is not already up.
301 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
303 struct svc_serv *serv;
304 struct svc_rqst *rqstp;
305 int (*callback_svc)(void *vrqstp);
306 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
309 int minorversion_setup;
310 struct net *net = xprt->xprt_net;
312 mutex_lock(&nfs_callback_mutex);
314 serv = nfs_callback_create_svc(minorversion);
320 if (cb_info->users++ || cb_info->task != NULL) {
321 nfs_callback_bc_serv(minorversion, xprt, cb_info);
325 ret = nfs_callback_up_net(minorversion, serv, net);
329 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
330 serv, xprt, &rqstp, &callback_svc);
331 if (!minorversion_setup) {
332 /* v4.0 callback setup */
333 rqstp = nfs4_callback_up(serv, xprt);
334 callback_svc = nfs4_callback_svc;
338 ret = PTR_ERR(rqstp);
342 svc_sock_update_bufs(serv);
344 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
345 cb_info->serv = serv;
346 cb_info->rqst = rqstp;
347 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
348 if (IS_ERR(cb_info->task)) {
349 ret = PTR_ERR(cb_info->task);
350 svc_exit_thread(cb_info->rqst);
351 cb_info->rqst = NULL;
352 cb_info->task = NULL;
357 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
358 * svc_prepare_thread increments that. So we need to call svc_destroy
359 * on both success and failure so that the refcount is 1 when the
364 mutex_unlock(&nfs_callback_mutex);
367 svc_shutdown_net(serv, net);
369 dprintk("NFS: Couldn't create callback socket or server thread; "
376 * Kill the callback thread if it's no longer being used.
378 void nfs_callback_down(int minorversion, struct net *net)
380 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
382 mutex_lock(&nfs_callback_mutex);
384 if (cb_info->users == 0 && cb_info->task != NULL) {
385 kthread_stop(cb_info->task);
386 svc_shutdown_net(cb_info->serv, net);
387 svc_exit_thread(cb_info->rqst);
388 cb_info->serv = NULL;
389 cb_info->rqst = NULL;
390 cb_info->task = NULL;
392 mutex_unlock(&nfs_callback_mutex);
395 /* Boolean check of RPC_AUTH_GSS principal */
397 check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
399 char *p = rqstp->rq_cred.cr_principal;
401 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
404 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
405 if (clp->cl_minorversion != 0)
408 * It might just be a normal user principal, in which case
409 * userspace won't bother to tell us the name at all.
414 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
416 if (memcmp(p, "nfs@", 4) != 0)
419 if (strcmp(p, clp->cl_hostname) != 0)
425 * pg_authenticate method for nfsv4 callback threads.
427 * The authflavor has been negotiated, so an incorrect flavor is a server
428 * bug. Drop packets with incorrect authflavor.
430 * All other checking done after NFS decoding where the nfs_client can be
431 * found in nfs4_callback_compound
433 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
435 switch (rqstp->rq_authop->flavour) {
437 if (rqstp->rq_proc != CB_NULL)
441 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
442 if (svc_is_backchannel(rqstp))
449 * Define NFS4 callback program
451 static struct svc_version *nfs4_callback_version[] = {
452 [1] = &nfs4_callback_version1,
453 [4] = &nfs4_callback_version4,
456 static struct svc_stat nfs4_callback_stats;
458 static struct svc_program nfs4_callback_program = {
459 .pg_prog = NFS4_CALLBACK, /* RPC service number */
460 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
461 .pg_vers = nfs4_callback_version, /* version table */
462 .pg_name = "NFSv4 callback", /* service name */
463 .pg_class = "nfs", /* authentication class */
464 .pg_stats = &nfs4_callback_stats,
465 .pg_authenticate = nfs_callback_authenticate,