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 int nfs_callback_set_tcpport;
41 unsigned short nfs_callback_tcpport;
42 unsigned short nfs_callback_tcpport6;
43 #define NFS_CALLBACK_MAXPORTNR (65535U)
45 static int param_set_portnr(const char *val, const struct kernel_param *kp)
52 ret = strict_strtoul(val, 0, &num);
53 if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
55 *((unsigned int *)kp->arg) = num;
58 static struct kernel_param_ops param_ops_portnr = {
59 .set = param_set_portnr,
60 .get = param_get_uint,
62 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
64 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
67 * This is the NFSv4 callback kernel thread.
70 nfs4_callback_svc(void *vrqstp)
73 struct svc_rqst *rqstp = vrqstp;
77 while (!kthread_should_stop()) {
79 * Listen for a request on the socket
81 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
82 if (err == -EAGAIN || err == -EINTR) {
88 printk(KERN_WARNING "%s: unexpected error "
89 "from svc_recv (%d)\n", __func__, err);
92 schedule_timeout_uninterruptible(HZ);
102 * Prepare to bring up the NFSv4 callback service
105 nfs4_callback_up(struct svc_serv *serv)
109 ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET,
110 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
113 nfs_callback_tcpport = ret;
114 dprintk("NFS: Callback listener port = %u (af %u)\n",
115 nfs_callback_tcpport, PF_INET);
117 ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET6,
118 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
120 nfs_callback_tcpport6 = ret;
121 dprintk("NFS: Callback listener port = %u (af %u)\n",
122 nfs_callback_tcpport6, PF_INET6);
123 } else if (ret == -EAFNOSUPPORT)
128 return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
136 #if defined(CONFIG_NFS_V4_1)
138 * The callback service for NFSv4.1 callbacks
141 nfs41_callback_svc(void *vrqstp)
143 struct svc_rqst *rqstp = vrqstp;
144 struct svc_serv *serv = rqstp->rq_server;
145 struct rpc_rqst *req;
151 while (!kthread_should_stop()) {
152 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_UNINTERRUPTIBLE);
153 spin_lock_bh(&serv->sv_cb_lock);
154 if (!list_empty(&serv->sv_cb_list)) {
155 req = list_first_entry(&serv->sv_cb_list,
156 struct rpc_rqst, rq_bc_list);
157 list_del(&req->rq_bc_list);
158 spin_unlock_bh(&serv->sv_cb_lock);
159 finish_wait(&serv->sv_cb_waitq, &wq);
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);
166 /* schedule_timeout to game the hung task watchdog */
167 schedule_timeout(60 * HZ);
168 finish_wait(&serv->sv_cb_waitq, &wq);
175 * Bring up the NFSv4.1 callback service
178 nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
180 struct svc_rqst *rqstp;
184 * Create an svc_sock for the back channel service that shares the
185 * fore channel connection.
186 * Returns the input port (0) and sets the svc_serv bc_xprt on success
188 ret = svc_create_xprt(serv, "tcp-bc", &init_net, PF_INET, 0,
191 rqstp = ERR_PTR(ret);
196 * Save the svc_serv in the transport so that it can
197 * be referenced when the session backchannel is initialized
199 xprt->bc_serv = serv;
201 INIT_LIST_HEAD(&serv->sv_cb_list);
202 spin_lock_init(&serv->sv_cb_lock);
203 init_waitqueue_head(&serv->sv_cb_waitq);
204 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
206 svc_xprt_put(serv->sv_bc_xprt);
207 serv->sv_bc_xprt = NULL;
210 dprintk("--> %s return %ld\n", __func__,
211 IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
215 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
216 struct svc_serv *serv, struct rpc_xprt *xprt,
217 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
220 *rqstpp = nfs41_callback_up(serv, xprt);
221 *callback_svc = nfs41_callback_svc;
226 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
227 struct nfs_callback_data *cb_info)
230 xprt->bc_serv = cb_info->serv;
233 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
234 struct svc_serv *serv, struct rpc_xprt *xprt,
235 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
240 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
241 struct nfs_callback_data *cb_info)
244 #endif /* CONFIG_NFS_V4_1 */
247 * Bring up the callback thread if it is not already up.
249 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
251 struct svc_serv *serv = NULL;
252 struct svc_rqst *rqstp;
253 int (*callback_svc)(void *vrqstp);
254 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
257 int minorversion_setup;
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 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
271 serv, xprt, &rqstp, &callback_svc);
272 if (!minorversion_setup) {
273 /* v4.0 callback setup */
274 rqstp = nfs4_callback_up(serv);
275 callback_svc = nfs4_callback_svc;
279 ret = PTR_ERR(rqstp);
283 svc_sock_update_bufs(serv);
285 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
286 cb_info->serv = serv;
287 cb_info->rqst = rqstp;
288 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
289 if (IS_ERR(cb_info->task)) {
290 ret = PTR_ERR(cb_info->task);
291 svc_exit_thread(cb_info->rqst);
292 cb_info->rqst = NULL;
293 cb_info->task = NULL;
298 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
299 * svc_prepare_thread increments that. So we need to call svc_destroy
300 * on both success and failure so that the refcount is 1 when the
305 mutex_unlock(&nfs_callback_mutex);
308 dprintk("NFS: Couldn't create callback socket or server thread; "
315 * Kill the callback thread if it's no longer being used.
317 void nfs_callback_down(int minorversion)
319 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
321 mutex_lock(&nfs_callback_mutex);
323 if (cb_info->users == 0 && cb_info->task != NULL) {
324 kthread_stop(cb_info->task);
325 svc_exit_thread(cb_info->rqst);
326 cb_info->serv = NULL;
327 cb_info->rqst = NULL;
328 cb_info->task = NULL;
330 mutex_unlock(&nfs_callback_mutex);
333 /* Boolean check of RPC_AUTH_GSS principal */
335 check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
337 struct rpc_clnt *r = clp->cl_rpcclient;
338 char *p = svc_gss_principal(rqstp);
340 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
343 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
344 if (clp->cl_minorversion != 0)
347 * It might just be a normal user principal, in which case
348 * userspace won't bother to tell us the name at all.
353 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
355 if (memcmp(p, "nfs@", 4) != 0)
358 if (strcmp(p, r->cl_server) != 0)
364 * pg_authenticate method for nfsv4 callback threads.
366 * The authflavor has been negotiated, so an incorrect flavor is a server
367 * bug. Drop packets with incorrect authflavor.
369 * All other checking done after NFS decoding where the nfs_client can be
370 * found in nfs4_callback_compound
372 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
374 switch (rqstp->rq_authop->flavour) {
376 if (rqstp->rq_proc != CB_NULL)
380 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
381 if (svc_is_backchannel(rqstp))
388 * Define NFS4 callback program
390 static struct svc_version *nfs4_callback_version[] = {
391 [1] = &nfs4_callback_version1,
392 [4] = &nfs4_callback_version4,
395 static struct svc_stat nfs4_callback_stats;
397 static struct svc_program nfs4_callback_program = {
398 .pg_prog = NFS4_CALLBACK, /* RPC service number */
399 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
400 .pg_vers = nfs4_callback_version, /* version table */
401 .pg_name = "NFSv4 callback", /* service name */
402 .pg_class = "nfs", /* authentication class */
403 .pg_stats = &nfs4_callback_stats,
404 .pg_authenticate = nfs_callback_authenticate,