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;
43 * This is the NFSv4 callback kernel thread.
46 nfs4_callback_svc(void *vrqstp)
49 struct svc_rqst *rqstp = vrqstp;
53 while (!kthread_should_stop()) {
55 * Listen for a request on the socket
57 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
58 if (err == -EAGAIN || err == -EINTR) {
64 printk(KERN_WARNING "NFS: %s: unexpected error "
65 "from svc_recv (%d)\n", __func__, err);
68 schedule_timeout_uninterruptible(HZ);
78 * Prepare to bring up the NFSv4 callback service
80 static struct svc_rqst *
81 nfs4_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
85 ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET,
86 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
89 nfs_callback_tcpport = ret;
90 dprintk("NFS: Callback listener port = %u (af %u)\n",
91 nfs_callback_tcpport, PF_INET);
93 ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET6,
94 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
96 nfs_callback_tcpport6 = ret;
97 dprintk("NFS: Callback listener port = %u (af %u)\n",
98 nfs_callback_tcpport6, PF_INET6);
99 } else if (ret == -EAFNOSUPPORT)
104 return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
112 #if defined(CONFIG_NFS_V4_1)
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, struct rpc_xprt *xprt)
154 struct svc_rqst *rqstp;
158 * Create an svc_sock for the back channel service that shares the
159 * fore channel connection.
160 * Returns the input port (0) and sets the svc_serv bc_xprt on success
162 ret = svc_create_xprt(serv, "tcp-bc", &init_net, PF_INET, 0,
165 rqstp = ERR_PTR(ret);
170 * Save the svc_serv in the transport so that it can
171 * be referenced when the session backchannel is initialized
173 xprt->bc_serv = serv;
175 INIT_LIST_HEAD(&serv->sv_cb_list);
176 spin_lock_init(&serv->sv_cb_lock);
177 init_waitqueue_head(&serv->sv_cb_waitq);
178 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
180 svc_xprt_put(serv->sv_bc_xprt);
181 serv->sv_bc_xprt = NULL;
184 dprintk("--> %s return %ld\n", __func__,
185 IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
189 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
190 struct svc_serv *serv, struct rpc_xprt *xprt,
191 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
194 *rqstpp = nfs41_callback_up(serv, xprt);
195 *callback_svc = nfs41_callback_svc;
200 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
201 struct nfs_callback_data *cb_info)
204 xprt->bc_serv = cb_info->serv;
207 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
208 struct svc_serv *serv, struct rpc_xprt *xprt,
209 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
214 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
215 struct nfs_callback_data *cb_info)
218 #endif /* CONFIG_NFS_V4_1 */
221 * Bring up the callback thread if it is not already up.
223 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
225 struct svc_serv *serv = NULL;
226 struct svc_rqst *rqstp;
227 int (*callback_svc)(void *vrqstp);
228 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
231 int minorversion_setup;
232 struct net *net = &init_net;
234 mutex_lock(&nfs_callback_mutex);
235 if (cb_info->users++ || cb_info->task != NULL) {
236 nfs_callback_bc_serv(minorversion, xprt, cb_info);
239 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
245 ret = svc_bind(serv, net);
247 printk(KERN_WARNING "NFS: bind callback service failed\n");
251 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
252 serv, xprt, &rqstp, &callback_svc);
253 if (!minorversion_setup) {
254 /* v4.0 callback setup */
255 rqstp = nfs4_callback_up(serv, xprt);
256 callback_svc = nfs4_callback_svc;
260 ret = PTR_ERR(rqstp);
264 svc_sock_update_bufs(serv);
266 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
267 cb_info->serv = serv;
268 cb_info->rqst = rqstp;
269 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
270 if (IS_ERR(cb_info->task)) {
271 ret = PTR_ERR(cb_info->task);
272 svc_exit_thread(cb_info->rqst);
273 cb_info->rqst = NULL;
274 cb_info->task = NULL;
279 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
280 * svc_prepare_thread increments that. So we need to call svc_destroy
281 * on both success and failure so that the refcount is 1 when the
286 mutex_unlock(&nfs_callback_mutex);
289 dprintk("NFS: Couldn't create callback socket or server thread; "
293 svc_shutdown_net(serv, net);
298 * Kill the callback thread if it's no longer being used.
300 void nfs_callback_down(int minorversion)
302 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
304 mutex_lock(&nfs_callback_mutex);
306 if (cb_info->users == 0 && cb_info->task != NULL) {
307 kthread_stop(cb_info->task);
308 svc_shutdown_net(cb_info->serv, &init_net);
309 svc_exit_thread(cb_info->rqst);
310 cb_info->serv = NULL;
311 cb_info->rqst = NULL;
312 cb_info->task = NULL;
314 mutex_unlock(&nfs_callback_mutex);
317 /* Boolean check of RPC_AUTH_GSS principal */
319 check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
321 char *p = rqstp->rq_cred.cr_principal;
323 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
326 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
327 if (clp->cl_minorversion != 0)
330 * It might just be a normal user principal, in which case
331 * userspace won't bother to tell us the name at all.
336 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
338 if (memcmp(p, "nfs@", 4) != 0)
341 if (strcmp(p, clp->cl_hostname) != 0)
347 * pg_authenticate method for nfsv4 callback threads.
349 * The authflavor has been negotiated, so an incorrect flavor is a server
350 * bug. Drop packets with incorrect authflavor.
352 * All other checking done after NFS decoding where the nfs_client can be
353 * found in nfs4_callback_compound
355 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
357 switch (rqstp->rq_authop->flavour) {
359 if (rqstp->rq_proc != CB_NULL)
363 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
364 if (svc_is_backchannel(rqstp))
371 * Define NFS4 callback program
373 static struct svc_version *nfs4_callback_version[] = {
374 [1] = &nfs4_callback_version1,
375 [4] = &nfs4_callback_version4,
378 static struct svc_stat nfs4_callback_stats;
380 static struct svc_program nfs4_callback_program = {
381 .pg_prog = NFS4_CALLBACK, /* RPC service number */
382 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
383 .pg_vers = nfs4_callback_version, /* version table */
384 .pg_name = "NFSv4 callback", /* service name */
385 .pg_class = "nfs", /* authentication class */
386 .pg_stats = &nfs4_callback_stats,
387 .pg_authenticate = nfs_callback_authenticate,