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/errno.h>
16 #include <linux/mutex.h>
17 #include <linux/freezer.h>
18 #include <linux/kthread.h>
19 #include <linux/sunrpc/svcauth_gss.h>
20 #include <linux/sunrpc/bc_xprt.h>
22 #include <net/inet_sock.h>
29 #define NFSDBG_FACILITY NFSDBG_CALLBACK
31 struct nfs_callback_data {
33 struct svc_serv *serv;
34 struct svc_rqst *rqst;
35 struct task_struct *task;
38 static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
39 static DEFINE_MUTEX(nfs_callback_mutex);
40 static struct svc_program nfs4_callback_program;
42 static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
45 struct nfs_net *nn = net_generic(net, nfs_net_id);
47 ret = svc_create_xprt(serv, "tcp", net, PF_INET,
48 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
51 nn->nfs_callback_tcpport = ret;
52 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
53 nn->nfs_callback_tcpport, PF_INET, net);
55 ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
56 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
58 nn->nfs_callback_tcpport6 = ret;
59 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
60 nn->nfs_callback_tcpport6, PF_INET6, net);
61 } else if (ret != -EAFNOSUPPORT)
66 return (ret) ? ret : -ENOMEM;
70 * This is the NFSv4 callback kernel thread.
73 nfs4_callback_svc(void *vrqstp)
76 struct svc_rqst *rqstp = vrqstp;
80 while (!kthread_should_stop()) {
82 * Listen for a request on the socket
84 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
85 if (err == -EAGAIN || err == -EINTR)
93 * Prepare to bring up the NFSv4 callback service
95 static struct svc_rqst *
96 nfs4_callback_up(struct svc_serv *serv)
98 return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
101 #if defined(CONFIG_NFS_V4_1)
102 static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
105 * Create an svc_sock for the back channel service that shares the
106 * fore channel connection.
107 * Returns the input port (0) and sets the svc_serv bc_xprt on success
109 return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
114 * The callback service for NFSv4.1 callbacks
117 nfs41_callback_svc(void *vrqstp)
119 struct svc_rqst *rqstp = vrqstp;
120 struct svc_serv *serv = rqstp->rq_server;
121 struct rpc_rqst *req;
127 while (!kthread_should_stop()) {
131 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
132 spin_lock_bh(&serv->sv_cb_lock);
133 if (!list_empty(&serv->sv_cb_list)) {
134 req = list_first_entry(&serv->sv_cb_list,
135 struct rpc_rqst, rq_bc_list);
136 list_del(&req->rq_bc_list);
137 spin_unlock_bh(&serv->sv_cb_lock);
138 finish_wait(&serv->sv_cb_waitq, &wq);
139 dprintk("Invoking bc_svc_process()\n");
140 error = bc_svc_process(serv, req, rqstp);
141 dprintk("bc_svc_process() returned w/ error code= %d\n",
144 spin_unlock_bh(&serv->sv_cb_lock);
146 finish_wait(&serv->sv_cb_waitq, &wq);
148 flush_signals(current);
154 * Bring up the NFSv4.1 callback service
156 static struct svc_rqst *
157 nfs41_callback_up(struct svc_serv *serv)
159 struct svc_rqst *rqstp;
161 INIT_LIST_HEAD(&serv->sv_cb_list);
162 spin_lock_init(&serv->sv_cb_lock);
163 init_waitqueue_head(&serv->sv_cb_waitq);
164 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
165 dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp));
169 static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
170 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
172 *rqstpp = nfs41_callback_up(serv);
173 *callback_svc = nfs41_callback_svc;
176 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
177 struct svc_serv *serv)
181 * Save the svc_serv in the transport so that it can
182 * be referenced when the session backchannel is initialized
184 xprt->bc_serv = serv;
187 static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
192 static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
193 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
195 *rqstpp = ERR_PTR(-ENOTSUPP);
196 *callback_svc = ERR_PTR(-ENOTSUPP);
199 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
200 struct svc_serv *serv)
203 #endif /* CONFIG_NFS_V4_1 */
205 static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
206 struct svc_serv *serv)
208 struct svc_rqst *rqstp;
209 int (*callback_svc)(void *vrqstp);
210 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
213 nfs_callback_bc_serv(minorversion, xprt, serv);
218 switch (minorversion) {
220 /* v4.0 callback setup */
221 rqstp = nfs4_callback_up(serv);
222 callback_svc = nfs4_callback_svc;
225 nfs_minorversion_callback_svc_setup(serv,
226 &rqstp, &callback_svc);
230 return PTR_ERR(rqstp);
232 svc_sock_update_bufs(serv);
234 cb_info->serv = serv;
235 cb_info->rqst = rqstp;
236 cb_info->task = kthread_create(callback_svc, cb_info->rqst,
237 "nfsv4.%u-svc", minorversion);
238 if (IS_ERR(cb_info->task)) {
239 ret = PTR_ERR(cb_info->task);
240 svc_exit_thread(cb_info->rqst);
241 cb_info->rqst = NULL;
242 cb_info->task = NULL;
245 rqstp->rq_task = cb_info->task;
246 wake_up_process(cb_info->task);
247 dprintk("nfs_callback_up: service started\n");
251 static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
253 struct nfs_net *nn = net_generic(net, nfs_net_id);
255 if (--nn->cb_users[minorversion])
258 dprintk("NFS: destroy per-net callback data; net=%p\n", net);
259 svc_shutdown_net(serv, net);
262 static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net)
264 struct nfs_net *nn = net_generic(net, nfs_net_id);
267 if (nn->cb_users[minorversion]++)
270 dprintk("NFS: create per-net callback data; net=%p\n", net);
272 ret = svc_bind(serv, net);
274 printk(KERN_WARNING "NFS: bind callback service failed\n");
278 switch (minorversion) {
280 ret = nfs4_callback_up_net(serv, net);
284 ret = nfs41_callback_up_net(serv, net);
287 printk(KERN_ERR "NFS: unknown callback version: %d\n",
294 printk(KERN_ERR "NFS: callback service start failed\n");
300 svc_rpcb_cleanup(serv, net);
302 dprintk("NFS: Couldn't create callback socket: err = %d; "
303 "net = %p\n", ret, net);
307 static struct svc_serv_ops nfs_cb_sv_ops = {
308 .svo_enqueue_xprt = svc_xprt_do_enqueue,
311 static struct svc_serv *nfs_callback_create_svc(int minorversion)
313 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
314 struct svc_serv *serv;
317 * Check whether we're already up and running.
321 * Note: increase service usage, because later in case of error
322 * svc_destroy() will be called.
324 svc_get(cb_info->serv);
325 return cb_info->serv;
329 * Sanity check: if there's no task,
330 * we should be the first user ...
333 printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
336 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, &nfs_cb_sv_ops);
338 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
339 return ERR_PTR(-ENOMEM);
341 /* As there is only one thread we need to over-ride the
342 * default maximum of 80 connections
344 serv->sv_maxconn = 1024;
345 dprintk("nfs_callback_create_svc: service created\n");
350 * Bring up the callback thread if it is not already up.
352 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
354 struct svc_serv *serv;
355 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
357 struct net *net = xprt->xprt_net;
359 mutex_lock(&nfs_callback_mutex);
361 serv = nfs_callback_create_svc(minorversion);
367 ret = nfs_callback_up_net(minorversion, serv, net);
371 ret = nfs_callback_start_svc(minorversion, xprt, serv);
377 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
378 * svc_prepare_thread increments that. So we need to call svc_destroy
379 * on both success and failure so that the refcount is 1 when the
385 mutex_unlock(&nfs_callback_mutex);
389 nfs_callback_down_net(minorversion, serv, net);
390 dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
395 * Kill the callback thread if it's no longer being used.
397 void nfs_callback_down(int minorversion, struct net *net)
399 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
401 mutex_lock(&nfs_callback_mutex);
402 nfs_callback_down_net(minorversion, cb_info->serv, net);
404 if (cb_info->users == 0 && cb_info->task != NULL) {
405 kthread_stop(cb_info->task);
406 dprintk("nfs_callback_down: service stopped\n");
407 svc_exit_thread(cb_info->rqst);
408 dprintk("nfs_callback_down: service destroyed\n");
409 cb_info->serv = NULL;
410 cb_info->rqst = NULL;
411 cb_info->task = NULL;
413 mutex_unlock(&nfs_callback_mutex);
416 /* Boolean check of RPC_AUTH_GSS principal */
418 check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
420 char *p = rqstp->rq_cred.cr_principal;
422 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
425 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
426 if (clp->cl_minorversion != 0)
429 * It might just be a normal user principal, in which case
430 * userspace won't bother to tell us the name at all.
436 * Did we get the acceptor from userland during the SETCLIENID
439 if (clp->cl_acceptor)
440 return !strcmp(p, clp->cl_acceptor);
443 * Otherwise try to verify it using the cl_hostname. Note that this
444 * doesn't work if a non-canonical hostname was used in the devname.
447 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
449 if (memcmp(p, "nfs@", 4) != 0)
452 if (strcmp(p, clp->cl_hostname) != 0)
458 * pg_authenticate method for nfsv4 callback threads.
460 * The authflavor has been negotiated, so an incorrect flavor is a server
461 * bug. Deny packets with incorrect authflavor.
463 * All other checking done after NFS decoding where the nfs_client can be
464 * found in nfs4_callback_compound
466 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
468 switch (rqstp->rq_authop->flavour) {
470 if (rqstp->rq_proc != CB_NULL)
474 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
475 if (svc_is_backchannel(rqstp))
482 * Define NFS4 callback program
484 static struct svc_version *nfs4_callback_version[] = {
485 [1] = &nfs4_callback_version1,
486 [4] = &nfs4_callback_version4,
489 static struct svc_stat nfs4_callback_stats;
491 static struct svc_program nfs4_callback_program = {
492 .pg_prog = NFS4_CALLBACK, /* RPC service number */
493 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
494 .pg_vers = nfs4_callback_version, /* version table */
495 .pg_name = "NFSv4 callback", /* service name */
496 .pg_class = "nfs", /* authentication class */
497 .pg_stats = &nfs4_callback_stats,
498 .pg_authenticate = nfs_callback_authenticate,