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, 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;
62 static int param_get_portnr(char *buffer, struct kernel_param *kp)
64 return param_get_uint(buffer, kp);
66 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
68 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
71 * This is the NFSv4 callback kernel thread.
74 nfs4_callback_svc(void *vrqstp)
77 struct svc_rqst *rqstp = vrqstp;
81 while (!kthread_should_stop()) {
83 * Listen for a request on the socket
85 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
86 if (err == -EAGAIN || err == -EINTR) {
92 printk(KERN_WARNING "%s: unexpected error "
93 "from svc_recv (%d)\n", __func__, err);
96 schedule_timeout_uninterruptible(HZ);
106 * Prepare to bring up the NFSv4 callback service
109 nfs4_callback_up(struct svc_serv *serv)
113 ret = svc_create_xprt(serv, "tcp", PF_INET,
114 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
117 nfs_callback_tcpport = ret;
118 dprintk("NFS: Callback listener port = %u (af %u)\n",
119 nfs_callback_tcpport, PF_INET);
121 ret = svc_create_xprt(serv, "tcp", PF_INET6,
122 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
124 nfs_callback_tcpport6 = ret;
125 dprintk("NFS: Callback listener port = %u (af %u)\n",
126 nfs_callback_tcpport6, PF_INET6);
127 } else if (ret == -EAFNOSUPPORT)
132 return svc_prepare_thread(serv, &serv->sv_pools[0]);
140 #if defined(CONFIG_NFS_V4_1)
142 * The callback service for NFSv4.1 callbacks
145 nfs41_callback_svc(void *vrqstp)
147 struct svc_rqst *rqstp = vrqstp;
148 struct svc_serv *serv = rqstp->rq_server;
149 struct rpc_rqst *req;
155 while (!kthread_should_stop()) {
156 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
157 spin_lock_bh(&serv->sv_cb_lock);
158 if (!list_empty(&serv->sv_cb_list)) {
159 req = list_first_entry(&serv->sv_cb_list,
160 struct rpc_rqst, rq_bc_list);
161 list_del(&req->rq_bc_list);
162 spin_unlock_bh(&serv->sv_cb_lock);
163 dprintk("Invoking bc_svc_process()\n");
164 error = bc_svc_process(serv, req, rqstp);
165 dprintk("bc_svc_process() returned w/ error code= %d\n",
168 spin_unlock_bh(&serv->sv_cb_lock);
171 finish_wait(&serv->sv_cb_waitq, &wq);
177 * Bring up the NFSv4.1 callback service
180 nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
182 struct svc_xprt *bc_xprt;
183 struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
185 dprintk("--> %s\n", __func__);
186 /* Create a svc_sock for the service */
187 bc_xprt = svc_sock_create(serv, xprt->prot);
192 * Save the svc_serv in the transport so that it can
193 * be referenced when the session backchannel is initialized
195 serv->bc_xprt = bc_xprt;
196 xprt->bc_serv = serv;
198 INIT_LIST_HEAD(&serv->sv_cb_list);
199 spin_lock_init(&serv->sv_cb_lock);
200 init_waitqueue_head(&serv->sv_cb_waitq);
201 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
203 svc_sock_destroy(bc_xprt);
205 dprintk("--> %s return %p\n", __func__, rqstp);
209 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
210 struct svc_serv *serv, struct rpc_xprt *xprt,
211 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
214 *rqstpp = nfs41_callback_up(serv, xprt);
215 *callback_svc = nfs41_callback_svc;
220 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
221 struct nfs_callback_data *cb_info)
224 xprt->bc_serv = cb_info->serv;
227 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
228 struct svc_serv *serv, struct rpc_xprt *xprt,
229 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
234 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
235 struct nfs_callback_data *cb_info)
238 #endif /* CONFIG_NFS_V4_1 */
241 * Bring up the callback thread if it is not already up.
243 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
245 struct svc_serv *serv = NULL;
246 struct svc_rqst *rqstp;
247 int (*callback_svc)(void *vrqstp);
248 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
251 int minorversion_setup;
253 mutex_lock(&nfs_callback_mutex);
254 if (cb_info->users++ || cb_info->task != NULL) {
255 nfs_callback_bc_serv(minorversion, xprt, cb_info);
258 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
264 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
265 serv, xprt, &rqstp, &callback_svc);
266 if (!minorversion_setup) {
267 /* v4.0 callback setup */
268 rqstp = nfs4_callback_up(serv);
269 callback_svc = nfs4_callback_svc;
273 ret = PTR_ERR(rqstp);
277 svc_sock_update_bufs(serv);
279 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
280 cb_info->serv = serv;
281 cb_info->rqst = rqstp;
282 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
283 if (IS_ERR(cb_info->task)) {
284 ret = PTR_ERR(cb_info->task);
285 svc_exit_thread(cb_info->rqst);
286 cb_info->rqst = NULL;
287 cb_info->task = NULL;
292 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
293 * svc_prepare_thread increments that. So we need to call svc_destroy
294 * on both success and failure so that the refcount is 1 when the
299 mutex_unlock(&nfs_callback_mutex);
302 dprintk("NFS: Couldn't create callback socket or server thread; "
309 * Kill the callback thread if it's no longer being used.
311 void nfs_callback_down(int minorversion)
313 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
315 mutex_lock(&nfs_callback_mutex);
317 if (cb_info->users == 0 && cb_info->task != NULL) {
318 kthread_stop(cb_info->task);
319 svc_exit_thread(cb_info->rqst);
320 cb_info->serv = NULL;
321 cb_info->rqst = NULL;
322 cb_info->task = NULL;
324 mutex_unlock(&nfs_callback_mutex);
327 static int check_gss_callback_principal(struct nfs_client *clp,
328 struct svc_rqst *rqstp)
330 struct rpc_clnt *r = clp->cl_rpcclient;
331 char *p = svc_gss_principal(rqstp);
334 * It might just be a normal user principal, in which case
335 * userspace won't bother to tell us the name at all.
340 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
342 if (memcmp(p, "nfs@", 4) != 0)
345 if (strcmp(p, r->cl_server) != 0)
350 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
352 struct nfs_client *clp;
353 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
356 /* Don't talk to strangers */
357 clp = nfs_find_client(svc_addr(rqstp), 4);
361 dprintk("%s: %s NFSv4 callback!\n", __func__,
362 svc_print_addr(rqstp, buf, sizeof(buf)));
364 switch (rqstp->rq_authop->flavour) {
366 if (rqstp->rq_proc != CB_NULL)
372 ret = check_gss_callback_principal(clp, rqstp);
382 * Define NFS4 callback program
384 static struct svc_version *nfs4_callback_version[] = {
385 [1] = &nfs4_callback_version1,
386 [4] = &nfs4_callback_version4,
389 static struct svc_stat nfs4_callback_stats;
391 static struct svc_program nfs4_callback_program = {
392 .pg_prog = NFS4_CALLBACK, /* RPC service number */
393 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
394 .pg_vers = nfs4_callback_version, /* version table */
395 .pg_name = "NFSv4 callback", /* service name */
396 .pg_class = "nfs", /* authentication class */
397 .pg_stats = &nfs4_callback_stats,
398 .pg_authenticate = nfs_callback_authenticate,