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>
20 #include <linux/nsproxy.h>
22 #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 unsigned int nfs_callback_set_tcpport;
42 unsigned short nfs_callback_tcpport;
43 unsigned short nfs_callback_tcpport6;
44 #define NFS_CALLBACK_MAXPORTNR (65535U)
46 static int param_set_portnr(const char *val, const struct kernel_param *kp)
53 ret = strict_strtoul(val, 0, &num);
54 if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
56 *((unsigned int *)kp->arg) = num;
59 static struct kernel_param_ops param_ops_portnr = {
60 .set = param_set_portnr,
61 .get = param_get_uint,
63 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
65 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
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) {
89 printk(KERN_WARNING "NFS: %s: unexpected error "
90 "from svc_recv (%d)\n", __func__, err);
93 schedule_timeout_uninterruptible(HZ);
103 * Prepare to bring up the NFSv4 callback service
105 static struct svc_rqst *
106 nfs4_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
110 ret = svc_create_xprt(serv, "tcp", xprt->xprt_net, PF_INET,
111 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
114 nfs_callback_tcpport = ret;
115 dprintk("NFS: Callback listener port = %u (af %u)\n",
116 nfs_callback_tcpport, PF_INET);
118 ret = svc_create_xprt(serv, "tcp", xprt->xprt_net, PF_INET6,
119 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
121 nfs_callback_tcpport6 = ret;
122 dprintk("NFS: Callback listener port = %u (af %u)\n",
123 nfs_callback_tcpport6, PF_INET6);
124 } else if (ret == -EAFNOSUPPORT)
129 return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
137 #if defined(CONFIG_NFS_V4_1)
139 * The callback service for NFSv4.1 callbacks
142 nfs41_callback_svc(void *vrqstp)
144 struct svc_rqst *rqstp = vrqstp;
145 struct svc_serv *serv = rqstp->rq_server;
146 struct rpc_rqst *req;
152 while (!kthread_should_stop()) {
153 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
154 spin_lock_bh(&serv->sv_cb_lock);
155 if (!list_empty(&serv->sv_cb_list)) {
156 req = list_first_entry(&serv->sv_cb_list,
157 struct rpc_rqst, rq_bc_list);
158 list_del(&req->rq_bc_list);
159 spin_unlock_bh(&serv->sv_cb_lock);
160 dprintk("Invoking bc_svc_process()\n");
161 error = bc_svc_process(serv, req, rqstp);
162 dprintk("bc_svc_process() returned w/ error code= %d\n",
165 spin_unlock_bh(&serv->sv_cb_lock);
168 finish_wait(&serv->sv_cb_waitq, &wq);
174 * Bring up the NFSv4.1 callback service
176 static struct svc_rqst *
177 nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
179 struct svc_rqst *rqstp;
183 * Create an svc_sock for the back channel service that shares the
184 * fore channel connection.
185 * Returns the input port (0) and sets the svc_serv bc_xprt on success
187 ret = svc_create_xprt(serv, "tcp-bc", xprt->xprt_net, PF_INET, 0,
190 rqstp = ERR_PTR(ret);
195 * Save the svc_serv in the transport so that it can
196 * be referenced when the session backchannel is initialized
198 xprt->bc_serv = serv;
200 INIT_LIST_HEAD(&serv->sv_cb_list);
201 spin_lock_init(&serv->sv_cb_lock);
202 init_waitqueue_head(&serv->sv_cb_waitq);
203 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
205 svc_xprt_put(serv->sv_bc_xprt);
206 serv->sv_bc_xprt = NULL;
209 dprintk("--> %s return %ld\n", __func__,
210 IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
214 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
215 struct svc_serv *serv, struct rpc_xprt *xprt,
216 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
219 *rqstpp = nfs41_callback_up(serv, xprt);
220 *callback_svc = nfs41_callback_svc;
225 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
226 struct nfs_callback_data *cb_info)
229 xprt->bc_serv = cb_info->serv;
232 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
233 struct svc_serv *serv, struct rpc_xprt *xprt,
234 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
239 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
240 struct nfs_callback_data *cb_info)
243 #endif /* CONFIG_NFS_V4_1 */
246 * Bring up the callback thread if it is not already up.
248 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
250 struct svc_serv *serv = NULL;
251 struct svc_rqst *rqstp;
252 int (*callback_svc)(void *vrqstp);
253 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
256 int minorversion_setup;
257 struct net *net = current->nsproxy->net_ns;
259 mutex_lock(&nfs_callback_mutex);
260 if (cb_info->users++ || cb_info->task != NULL) {
261 nfs_callback_bc_serv(minorversion, xprt, cb_info);
264 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
270 ret = svc_bind(serv, net);
272 printk(KERN_WARNING "NFS: bind callback service failed\n");
276 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
277 serv, xprt, &rqstp, &callback_svc);
278 if (!minorversion_setup) {
279 /* v4.0 callback setup */
280 rqstp = nfs4_callback_up(serv, xprt);
281 callback_svc = nfs4_callback_svc;
285 ret = PTR_ERR(rqstp);
289 svc_sock_update_bufs(serv);
291 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
292 cb_info->serv = serv;
293 cb_info->rqst = rqstp;
294 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
295 if (IS_ERR(cb_info->task)) {
296 ret = PTR_ERR(cb_info->task);
297 svc_exit_thread(cb_info->rqst);
298 cb_info->rqst = NULL;
299 cb_info->task = NULL;
304 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
305 * svc_prepare_thread increments that. So we need to call svc_destroy
306 * on both success and failure so that the refcount is 1 when the
311 mutex_unlock(&nfs_callback_mutex);
314 dprintk("NFS: Couldn't create callback socket or server thread; "
318 svc_shutdown_net(serv, net);
323 * Kill the callback thread if it's no longer being used.
325 void nfs_callback_down(int minorversion)
327 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
329 mutex_lock(&nfs_callback_mutex);
331 if (cb_info->users == 0 && cb_info->task != NULL) {
332 kthread_stop(cb_info->task);
333 svc_shutdown_net(cb_info->serv, current->nsproxy->net_ns);
334 svc_exit_thread(cb_info->rqst);
335 cb_info->serv = NULL;
336 cb_info->rqst = NULL;
337 cb_info->task = NULL;
339 mutex_unlock(&nfs_callback_mutex);
342 /* Boolean check of RPC_AUTH_GSS principal */
344 check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
346 char *p = rqstp->rq_cred.cr_principal;
348 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
351 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
352 if (clp->cl_minorversion != 0)
355 * It might just be a normal user principal, in which case
356 * userspace won't bother to tell us the name at all.
361 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
363 if (memcmp(p, "nfs@", 4) != 0)
366 if (strcmp(p, clp->cl_hostname) != 0)
372 * pg_authenticate method for nfsv4 callback threads.
374 * The authflavor has been negotiated, so an incorrect flavor is a server
375 * bug. Drop packets with incorrect authflavor.
377 * All other checking done after NFS decoding where the nfs_client can be
378 * found in nfs4_callback_compound
380 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
382 switch (rqstp->rq_authop->flavour) {
384 if (rqstp->rq_proc != CB_NULL)
388 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
389 if (svc_is_backchannel(rqstp))
396 * Define NFS4 callback program
398 static struct svc_version *nfs4_callback_version[] = {
399 [1] = &nfs4_callback_version1,
400 [4] = &nfs4_callback_version4,
403 static struct svc_stat nfs4_callback_stats;
405 static struct svc_program nfs4_callback_program = {
406 .pg_prog = NFS4_CALLBACK, /* RPC service number */
407 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
408 .pg_vers = nfs4_callback_version, /* version table */
409 .pg_name = "NFSv4 callback", /* service name */
410 .pg_class = "nfs", /* authentication class */
411 .pg_stats = &nfs4_callback_stats,
412 .pg_authenticate = nfs_callback_authenticate,