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;
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 static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
43 struct nfs_net *nn = net_generic(net, nfs_net_id);
45 ret = svc_create_xprt(serv, "tcp", net, PF_INET,
46 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
49 nn->nfs_callback_tcpport = ret;
50 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
51 nn->nfs_callback_tcpport, PF_INET, net);
53 ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
54 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
56 nn->nfs_callback_tcpport6 = ret;
57 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
58 nn->nfs_callback_tcpport6, PF_INET6, net);
59 } else if (ret != -EAFNOSUPPORT)
64 return (ret) ? ret : -ENOMEM;
68 * This is the NFSv4 callback kernel thread.
71 nfs4_callback_svc(void *vrqstp)
74 struct svc_rqst *rqstp = vrqstp;
78 while (!kthread_should_stop()) {
80 * Listen for a request on the socket
82 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
83 if (err == -EAGAIN || err == -EINTR)
90 #if defined(CONFIG_NFS_V4_1)
92 * The callback service for NFSv4.1 callbacks
95 nfs41_callback_svc(void *vrqstp)
97 struct svc_rqst *rqstp = vrqstp;
98 struct svc_serv *serv = rqstp->rq_server;
105 while (!kthread_should_stop()) {
109 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
110 spin_lock_bh(&serv->sv_cb_lock);
111 if (!list_empty(&serv->sv_cb_list)) {
112 req = list_first_entry(&serv->sv_cb_list,
113 struct rpc_rqst, rq_bc_list);
114 list_del(&req->rq_bc_list);
115 spin_unlock_bh(&serv->sv_cb_lock);
116 finish_wait(&serv->sv_cb_waitq, &wq);
117 dprintk("Invoking bc_svc_process()\n");
118 error = bc_svc_process(serv, req, rqstp);
119 dprintk("bc_svc_process() returned w/ error code= %d\n",
122 spin_unlock_bh(&serv->sv_cb_lock);
124 finish_wait(&serv->sv_cb_waitq, &wq);
126 flush_signals(current);
131 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
132 struct svc_serv *serv)
136 * Save the svc_serv in the transport so that it can
137 * be referenced when the session backchannel is initialized
139 xprt->bc_serv = serv;
142 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
143 struct svc_serv *serv)
146 #endif /* CONFIG_NFS_V4_1 */
148 static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
149 struct svc_serv *serv)
151 int nrservs = nfs_callback_nr_threads;
154 nfs_callback_bc_serv(minorversion, xprt, serv);
156 if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)
157 nrservs = NFS4_MIN_NR_CALLBACK_THREADS;
159 if (serv->sv_nrthreads-1 == nrservs)
162 ret = serv->sv_ops->svo_setup(serv, NULL, nrservs);
164 serv->sv_ops->svo_setup(serv, NULL, 0);
167 dprintk("nfs_callback_up: service started\n");
171 static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
173 struct nfs_net *nn = net_generic(net, nfs_net_id);
175 if (--nn->cb_users[minorversion])
178 dprintk("NFS: destroy per-net callback data; net=%p\n", net);
179 svc_shutdown_net(serv, net);
182 static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
183 struct net *net, struct rpc_xprt *xprt)
185 struct nfs_net *nn = net_generic(net, nfs_net_id);
188 if (nn->cb_users[minorversion]++)
191 dprintk("NFS: create per-net callback data; net=%p\n", net);
193 ret = svc_bind(serv, net);
195 printk(KERN_WARNING "NFS: bind callback service failed\n");
199 ret = -EPROTONOSUPPORT;
200 if (minorversion == 0)
201 ret = nfs4_callback_up_net(serv, net);
202 else if (xprt->ops->bc_up)
203 ret = xprt->ops->bc_up(serv, net);
206 printk(KERN_ERR "NFS: callback service start failed\n");
212 svc_rpcb_cleanup(serv, net);
214 nn->cb_users[minorversion]--;
215 dprintk("NFS: Couldn't create callback socket: err = %d; "
216 "net = %p\n", ret, net);
220 static struct svc_serv_ops nfs40_cb_sv_ops = {
221 .svo_function = nfs4_callback_svc,
222 .svo_enqueue_xprt = svc_xprt_do_enqueue,
223 .svo_setup = svc_set_num_threads,
224 .svo_module = THIS_MODULE,
226 #if defined(CONFIG_NFS_V4_1)
227 static struct svc_serv_ops nfs41_cb_sv_ops = {
228 .svo_function = nfs41_callback_svc,
229 .svo_enqueue_xprt = svc_xprt_do_enqueue,
230 .svo_setup = svc_set_num_threads,
231 .svo_module = THIS_MODULE,
234 struct svc_serv_ops *nfs4_cb_sv_ops[] = {
235 [0] = &nfs40_cb_sv_ops,
236 [1] = &nfs41_cb_sv_ops,
239 struct svc_serv_ops *nfs4_cb_sv_ops[] = {
240 [0] = &nfs40_cb_sv_ops,
245 static struct svc_serv *nfs_callback_create_svc(int minorversion)
247 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
248 struct svc_serv *serv;
249 struct svc_serv_ops *sv_ops;
252 * Check whether we're already up and running.
256 * Note: increase service usage, because later in case of error
257 * svc_destroy() will be called.
259 svc_get(cb_info->serv);
260 return cb_info->serv;
263 switch (minorversion) {
265 sv_ops = nfs4_cb_sv_ops[0];
268 sv_ops = nfs4_cb_sv_ops[1];
272 return ERR_PTR(-ENOTSUPP);
275 * Sanity check: if there's no task,
276 * we should be the first user ...
279 printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
282 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops);
284 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
285 return ERR_PTR(-ENOMEM);
287 cb_info->serv = serv;
288 /* As there is only one thread we need to over-ride the
289 * default maximum of 80 connections
291 serv->sv_maxconn = 1024;
292 dprintk("nfs_callback_create_svc: service created\n");
297 * Bring up the callback thread if it is not already up.
299 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
301 struct svc_serv *serv;
302 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
304 struct net *net = xprt->xprt_net;
306 mutex_lock(&nfs_callback_mutex);
308 serv = nfs_callback_create_svc(minorversion);
314 ret = nfs_callback_up_net(minorversion, serv, net, xprt);
318 ret = nfs_callback_start_svc(minorversion, xprt, serv);
324 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
325 * svc_prepare_thread increments that. So we need to call svc_destroy
326 * on both success and failure so that the refcount is 1 when the
331 cb_info->serv = NULL;
334 mutex_unlock(&nfs_callback_mutex);
338 nfs_callback_down_net(minorversion, serv, net);
339 dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
344 * Kill the callback thread if it's no longer being used.
346 void nfs_callback_down(int minorversion, struct net *net)
348 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
349 struct svc_serv *serv;
351 mutex_lock(&nfs_callback_mutex);
352 serv = cb_info->serv;
353 nfs_callback_down_net(minorversion, serv, net);
355 if (cb_info->users == 0) {
357 serv->sv_ops->svo_setup(serv, NULL, 0);
359 dprintk("nfs_callback_down: service destroyed\n");
360 cb_info->serv = NULL;
362 mutex_unlock(&nfs_callback_mutex);
365 /* Boolean check of RPC_AUTH_GSS principal */
367 check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
369 char *p = rqstp->rq_cred.cr_principal;
371 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
374 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
375 if (clp->cl_minorversion != 0)
378 * It might just be a normal user principal, in which case
379 * userspace won't bother to tell us the name at all.
385 * Did we get the acceptor from userland during the SETCLIENID
388 if (clp->cl_acceptor)
389 return !strcmp(p, clp->cl_acceptor);
392 * Otherwise try to verify it using the cl_hostname. Note that this
393 * doesn't work if a non-canonical hostname was used in the devname.
396 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
398 if (memcmp(p, "nfs@", 4) != 0)
401 if (strcmp(p, clp->cl_hostname) != 0)
407 * pg_authenticate method for nfsv4 callback threads.
409 * The authflavor has been negotiated, so an incorrect flavor is a server
410 * bug. Deny packets with incorrect authflavor.
412 * All other checking done after NFS decoding where the nfs_client can be
413 * found in nfs4_callback_compound
415 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
417 switch (rqstp->rq_authop->flavour) {
419 if (rqstp->rq_proc != CB_NULL)
423 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
424 if (svc_is_backchannel(rqstp))
431 * Define NFS4 callback program
433 static struct svc_version *nfs4_callback_version[] = {
434 [1] = &nfs4_callback_version1,
435 [4] = &nfs4_callback_version4,
438 static struct svc_stat nfs4_callback_stats;
440 static struct svc_program nfs4_callback_program = {
441 .pg_prog = NFS4_CALLBACK, /* RPC service number */
442 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
443 .pg_vers = nfs4_callback_version, /* version table */
444 .pg_name = "NFSv4 callback", /* service name */
445 .pg_class = "nfs", /* authentication class */
446 .pg_stats = &nfs4_callback_stats,
447 .pg_authenticate = nfs_callback_authenticate,