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()) {
128 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
129 spin_lock_bh(&serv->sv_cb_lock);
130 if (!list_empty(&serv->sv_cb_list)) {
131 req = list_first_entry(&serv->sv_cb_list,
132 struct rpc_rqst, rq_bc_list);
133 list_del(&req->rq_bc_list);
134 spin_unlock_bh(&serv->sv_cb_lock);
135 dprintk("Invoking bc_svc_process()\n");
136 error = bc_svc_process(serv, req, rqstp);
137 dprintk("bc_svc_process() returned w/ error code= %d\n",
140 spin_unlock_bh(&serv->sv_cb_lock);
143 finish_wait(&serv->sv_cb_waitq, &wq);
149 * Bring up the NFSv4.1 callback service
151 static struct svc_rqst *
152 nfs41_callback_up(struct svc_serv *serv)
154 struct svc_rqst *rqstp;
156 INIT_LIST_HEAD(&serv->sv_cb_list);
157 spin_lock_init(&serv->sv_cb_lock);
158 init_waitqueue_head(&serv->sv_cb_waitq);
159 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
161 svc_xprt_put(serv->sv_bc_xprt);
162 serv->sv_bc_xprt = NULL;
164 dprintk("--> %s return %ld\n", __func__,
165 IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
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];
214 nfs_callback_bc_serv(minorversion, xprt, serv);
219 switch (minorversion) {
221 /* v4.0 callback setup */
222 rqstp = nfs4_callback_up(serv);
223 callback_svc = nfs4_callback_svc;
226 nfs_minorversion_callback_svc_setup(serv,
227 &rqstp, &callback_svc);
231 return PTR_ERR(rqstp);
233 svc_sock_update_bufs(serv);
235 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
236 cb_info->serv = serv;
237 cb_info->rqst = rqstp;
238 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
239 if (IS_ERR(cb_info->task)) {
240 ret = PTR_ERR(cb_info->task);
241 svc_exit_thread(cb_info->rqst);
242 cb_info->rqst = NULL;
243 cb_info->task = NULL;
246 dprintk("nfs_callback_up: service started\n");
250 static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
252 struct nfs_net *nn = net_generic(net, nfs_net_id);
254 if (--nn->cb_users[minorversion])
257 dprintk("NFS: destroy per-net callback data; net=%p\n", net);
258 svc_shutdown_net(serv, net);
261 static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net)
263 struct nfs_net *nn = net_generic(net, nfs_net_id);
266 if (nn->cb_users[minorversion]++)
269 dprintk("NFS: create per-net callback data; net=%p\n", net);
271 ret = svc_bind(serv, net);
273 printk(KERN_WARNING "NFS: bind callback service failed\n");
277 switch (minorversion) {
279 ret = nfs4_callback_up_net(serv, net);
282 ret = nfs41_callback_up_net(serv, net);
285 printk(KERN_ERR "NFS: unknown callback version: %d\n",
292 printk(KERN_ERR "NFS: callback service start failed\n");
298 svc_rpcb_cleanup(serv, net);
300 dprintk("NFS: Couldn't create callback socket: err = %d; "
301 "net = %p\n", ret, net);
305 static struct svc_serv *nfs_callback_create_svc(int minorversion)
307 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
308 struct svc_serv *serv;
311 * Check whether we're already up and running.
315 * Note: increase service usage, because later in case of error
316 * svc_destroy() will be called.
318 svc_get(cb_info->serv);
319 return cb_info->serv;
323 * Sanity check: if there's no task,
324 * we should be the first user ...
327 printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
330 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
332 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
333 return ERR_PTR(-ENOMEM);
335 /* As there is only one thread we need to over-ride the
336 * default maximum of 80 connections
338 serv->sv_maxconn = 1024;
339 dprintk("nfs_callback_create_svc: service created\n");
344 * Bring up the callback thread if it is not already up.
346 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
348 struct svc_serv *serv;
349 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
351 struct net *net = xprt->xprt_net;
353 mutex_lock(&nfs_callback_mutex);
355 serv = nfs_callback_create_svc(minorversion);
361 ret = nfs_callback_up_net(minorversion, serv, net);
365 ret = nfs_callback_start_svc(minorversion, xprt, serv);
371 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
372 * svc_prepare_thread increments that. So we need to call svc_destroy
373 * on both success and failure so that the refcount is 1 when the
379 mutex_unlock(&nfs_callback_mutex);
383 nfs_callback_down_net(minorversion, serv, net);
384 dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
389 * Kill the callback thread if it's no longer being used.
391 void nfs_callback_down(int minorversion, struct net *net)
393 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
395 mutex_lock(&nfs_callback_mutex);
396 nfs_callback_down_net(minorversion, cb_info->serv, net);
398 if (cb_info->users == 0 && cb_info->task != NULL) {
399 kthread_stop(cb_info->task);
400 dprintk("nfs_callback_down: service stopped\n");
401 svc_exit_thread(cb_info->rqst);
402 dprintk("nfs_callback_down: service destroyed\n");
403 cb_info->serv = NULL;
404 cb_info->rqst = NULL;
405 cb_info->task = NULL;
407 mutex_unlock(&nfs_callback_mutex);
410 /* Boolean check of RPC_AUTH_GSS principal */
412 check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
414 char *p = rqstp->rq_cred.cr_principal;
416 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
419 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
420 if (clp->cl_minorversion != 0)
423 * It might just be a normal user principal, in which case
424 * userspace won't bother to tell us the name at all.
429 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
431 if (memcmp(p, "nfs@", 4) != 0)
434 if (strcmp(p, clp->cl_hostname) != 0)
440 * pg_authenticate method for nfsv4 callback threads.
442 * The authflavor has been negotiated, so an incorrect flavor is a server
443 * bug. Drop packets with incorrect authflavor.
445 * All other checking done after NFS decoding where the nfs_client can be
446 * found in nfs4_callback_compound
448 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
450 switch (rqstp->rq_authop->flavour) {
452 if (rqstp->rq_proc != CB_NULL)
456 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
457 if (svc_is_backchannel(rqstp))
464 * Define NFS4 callback program
466 static struct svc_version *nfs4_callback_version[] = {
467 [1] = &nfs4_callback_version1,
468 [4] = &nfs4_callback_version4,
471 static struct svc_stat nfs4_callback_stats;
473 static struct svc_program nfs4_callback_program = {
474 .pg_prog = NFS4_CALLBACK, /* RPC service number */
475 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
476 .pg_vers = nfs4_callback_version, /* version table */
477 .pg_name = "NFSv4 callback", /* service name */
478 .pg_class = "nfs", /* authentication class */
479 .pg_stats = &nfs4_callback_stats,
480 .pg_authenticate = nfs_callback_authenticate,