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/smp_lock.h>
13 #include <linux/sunrpc/svc.h>
14 #include <linux/sunrpc/svcsock.h>
15 #include <linux/nfs_fs.h>
16 #include <linux/mutex.h>
17 #include <linux/freezer.h>
18 #include <linux/kthread.h>
19 #include <linux/sunrpc/svcauth_gss.h>
20 #if defined(CONFIG_NFS_V4_1)
21 #include <linux/sunrpc/bc_xprt.h>
24 #include <net/inet_sock.h>
30 #define NFSDBG_FACILITY NFSDBG_CALLBACK
32 struct nfs_callback_data {
34 struct svc_serv *serv;
35 struct svc_rqst *rqst;
36 struct task_struct *task;
39 static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
40 static DEFINE_MUTEX(nfs_callback_mutex);
41 static struct svc_program nfs4_callback_program;
43 unsigned int nfs_callback_set_tcpport;
44 unsigned short nfs_callback_tcpport;
45 unsigned short nfs_callback_tcpport6;
46 #define NFS_CALLBACK_MAXPORTNR (65535U)
48 static int param_set_portnr(const char *val, const struct kernel_param *kp)
55 ret = strict_strtoul(val, 0, &num);
56 if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
58 *((unsigned int *)kp->arg) = num;
61 static struct kernel_param_ops param_ops_portnr = {
62 .set = param_set_portnr,
63 .get = param_get_uint,
65 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
67 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
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) {
91 printk(KERN_WARNING "%s: unexpected error "
92 "from svc_recv (%d)\n", __func__, err);
95 schedule_timeout_uninterruptible(HZ);
105 * Prepare to bring up the NFSv4 callback service
108 nfs4_callback_up(struct svc_serv *serv)
112 ret = svc_create_xprt(serv, "tcp", PF_INET,
113 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
116 nfs_callback_tcpport = ret;
117 dprintk("NFS: Callback listener port = %u (af %u)\n",
118 nfs_callback_tcpport, PF_INET);
120 ret = svc_create_xprt(serv, "tcp", PF_INET6,
121 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
123 nfs_callback_tcpport6 = ret;
124 dprintk("NFS: Callback listener port = %u (af %u)\n",
125 nfs_callback_tcpport6, PF_INET6);
126 } else if (ret == -EAFNOSUPPORT)
131 return svc_prepare_thread(serv, &serv->sv_pools[0]);
139 #if defined(CONFIG_NFS_V4_1)
141 * The callback service for NFSv4.1 callbacks
144 nfs41_callback_svc(void *vrqstp)
146 struct svc_rqst *rqstp = vrqstp;
147 struct svc_serv *serv = rqstp->rq_server;
148 struct rpc_rqst *req;
154 while (!kthread_should_stop()) {
155 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
156 spin_lock_bh(&serv->sv_cb_lock);
157 if (!list_empty(&serv->sv_cb_list)) {
158 req = list_first_entry(&serv->sv_cb_list,
159 struct rpc_rqst, rq_bc_list);
160 list_del(&req->rq_bc_list);
161 spin_unlock_bh(&serv->sv_cb_lock);
162 dprintk("Invoking bc_svc_process()\n");
163 error = bc_svc_process(serv, req, rqstp);
164 dprintk("bc_svc_process() returned w/ error code= %d\n",
167 spin_unlock_bh(&serv->sv_cb_lock);
170 finish_wait(&serv->sv_cb_waitq, &wq);
176 * Bring up the NFSv4.1 callback service
179 nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
181 struct svc_xprt *bc_xprt;
182 struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
184 dprintk("--> %s\n", __func__);
185 /* Create a svc_sock for the service */
186 bc_xprt = svc_sock_create(serv, xprt->prot);
191 * Save the svc_serv in the transport so that it can
192 * be referenced when the session backchannel is initialized
194 serv->bc_xprt = bc_xprt;
195 xprt->bc_serv = serv;
197 INIT_LIST_HEAD(&serv->sv_cb_list);
198 spin_lock_init(&serv->sv_cb_lock);
199 init_waitqueue_head(&serv->sv_cb_waitq);
200 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
202 svc_sock_destroy(bc_xprt);
204 dprintk("--> %s return %p\n", __func__, rqstp);
208 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
209 struct svc_serv *serv, struct rpc_xprt *xprt,
210 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
213 *rqstpp = nfs41_callback_up(serv, xprt);
214 *callback_svc = nfs41_callback_svc;
219 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
220 struct nfs_callback_data *cb_info)
223 xprt->bc_serv = cb_info->serv;
226 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
227 struct svc_serv *serv, struct rpc_xprt *xprt,
228 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
233 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
234 struct nfs_callback_data *cb_info)
237 #endif /* CONFIG_NFS_V4_1 */
240 * Bring up the callback thread if it is not already up.
242 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
244 struct svc_serv *serv = NULL;
245 struct svc_rqst *rqstp;
246 int (*callback_svc)(void *vrqstp);
247 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
250 int minorversion_setup;
252 mutex_lock(&nfs_callback_mutex);
253 if (cb_info->users++ || cb_info->task != NULL) {
254 nfs_callback_bc_serv(minorversion, xprt, cb_info);
257 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
263 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
264 serv, xprt, &rqstp, &callback_svc);
265 if (!minorversion_setup) {
266 /* v4.0 callback setup */
267 rqstp = nfs4_callback_up(serv);
268 callback_svc = nfs4_callback_svc;
272 ret = PTR_ERR(rqstp);
276 svc_sock_update_bufs(serv);
278 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
279 cb_info->serv = serv;
280 cb_info->rqst = rqstp;
281 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
282 if (IS_ERR(cb_info->task)) {
283 ret = PTR_ERR(cb_info->task);
284 svc_exit_thread(cb_info->rqst);
285 cb_info->rqst = NULL;
286 cb_info->task = NULL;
291 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
292 * svc_prepare_thread increments that. So we need to call svc_destroy
293 * on both success and failure so that the refcount is 1 when the
298 mutex_unlock(&nfs_callback_mutex);
301 dprintk("NFS: Couldn't create callback socket or server thread; "
308 * Kill the callback thread if it's no longer being used.
310 void nfs_callback_down(int minorversion)
312 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
314 mutex_lock(&nfs_callback_mutex);
316 if (cb_info->users == 0 && cb_info->task != NULL) {
317 kthread_stop(cb_info->task);
318 svc_exit_thread(cb_info->rqst);
319 cb_info->serv = NULL;
320 cb_info->rqst = NULL;
321 cb_info->task = NULL;
323 mutex_unlock(&nfs_callback_mutex);
326 static int check_gss_callback_principal(struct nfs_client *clp,
327 struct svc_rqst *rqstp)
329 struct rpc_clnt *r = clp->cl_rpcclient;
330 char *p = svc_gss_principal(rqstp);
333 * It might just be a normal user principal, in which case
334 * userspace won't bother to tell us the name at all.
339 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
341 if (memcmp(p, "nfs@", 4) != 0)
344 if (strcmp(p, r->cl_server) != 0)
349 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
351 struct nfs_client *clp;
352 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
355 /* Don't talk to strangers */
356 clp = nfs_find_client(svc_addr(rqstp), 4);
360 dprintk("%s: %s NFSv4 callback!\n", __func__,
361 svc_print_addr(rqstp, buf, sizeof(buf)));
363 switch (rqstp->rq_authop->flavour) {
365 if (rqstp->rq_proc != CB_NULL)
371 ret = check_gss_callback_principal(clp, rqstp);
381 * Define NFS4 callback program
383 static struct svc_version *nfs4_callback_version[] = {
384 [1] = &nfs4_callback_version1,
385 [4] = &nfs4_callback_version4,
388 static struct svc_stat nfs4_callback_stats;
390 static struct svc_program nfs4_callback_program = {
391 .pg_prog = NFS4_CALLBACK, /* RPC service number */
392 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
393 .pg_vers = nfs4_callback_version, /* version table */
394 .pg_name = "NFSv4 callback", /* service name */
395 .pg_class = "nfs", /* authentication class */
396 .pg_stats = &nfs4_callback_stats,
397 .pg_authenticate = nfs_callback_authenticate,