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;
82 * FIXME: do we really need to run this under the BKL? If so, please
83 * add a comment about what it's intended to protect.
86 while (!kthread_should_stop()) {
88 * Listen for a request on the socket
90 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
91 if (err == -EAGAIN || err == -EINTR) {
97 printk(KERN_WARNING "%s: unexpected error "
98 "from svc_recv (%d)\n", __func__, err);
101 schedule_timeout_uninterruptible(HZ);
112 * Prepare to bring up the NFSv4 callback service
115 nfs4_callback_up(struct svc_serv *serv)
119 ret = svc_create_xprt(serv, "tcp", PF_INET,
120 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
123 nfs_callback_tcpport = ret;
124 dprintk("NFS: Callback listener port = %u (af %u)\n",
125 nfs_callback_tcpport, PF_INET);
127 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
128 ret = svc_create_xprt(serv, "tcp", PF_INET6,
129 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
131 nfs_callback_tcpport6 = ret;
132 dprintk("NFS: Callback listener port = %u (af %u)\n",
133 nfs_callback_tcpport6, PF_INET6);
134 } else if (ret == -EAFNOSUPPORT)
138 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
140 return svc_prepare_thread(serv, &serv->sv_pools[0]);
148 #if defined(CONFIG_NFS_V4_1)
150 * The callback service for NFSv4.1 callbacks
153 nfs41_callback_svc(void *vrqstp)
155 struct svc_rqst *rqstp = vrqstp;
156 struct svc_serv *serv = rqstp->rq_server;
157 struct rpc_rqst *req;
164 * FIXME: do we really need to run this under the BKL? If so, please
165 * add a comment about what it's intended to protect.
168 while (!kthread_should_stop()) {
169 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
170 spin_lock_bh(&serv->sv_cb_lock);
171 if (!list_empty(&serv->sv_cb_list)) {
172 req = list_first_entry(&serv->sv_cb_list,
173 struct rpc_rqst, rq_bc_list);
174 list_del(&req->rq_bc_list);
175 spin_unlock_bh(&serv->sv_cb_lock);
176 dprintk("Invoking bc_svc_process()\n");
177 error = bc_svc_process(serv, req, rqstp);
178 dprintk("bc_svc_process() returned w/ error code= %d\n",
181 spin_unlock_bh(&serv->sv_cb_lock);
184 finish_wait(&serv->sv_cb_waitq, &wq);
191 * Bring up the NFSv4.1 callback service
194 nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
196 struct svc_xprt *bc_xprt;
197 struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
199 dprintk("--> %s\n", __func__);
200 /* Create a svc_sock for the service */
201 bc_xprt = svc_sock_create(serv, xprt->prot);
206 * Save the svc_serv in the transport so that it can
207 * be referenced when the session backchannel is initialized
209 serv->bc_xprt = bc_xprt;
210 xprt->bc_serv = serv;
212 INIT_LIST_HEAD(&serv->sv_cb_list);
213 spin_lock_init(&serv->sv_cb_lock);
214 init_waitqueue_head(&serv->sv_cb_waitq);
215 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
217 svc_sock_destroy(bc_xprt);
219 dprintk("--> %s return %p\n", __func__, rqstp);
223 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
224 struct svc_serv *serv, struct rpc_xprt *xprt,
225 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
228 *rqstpp = nfs41_callback_up(serv, xprt);
229 *callback_svc = nfs41_callback_svc;
234 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
235 struct nfs_callback_data *cb_info)
238 xprt->bc_serv = cb_info->serv;
241 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
242 struct svc_serv *serv, struct rpc_xprt *xprt,
243 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
248 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
249 struct nfs_callback_data *cb_info)
252 #endif /* CONFIG_NFS_V4_1 */
255 * Bring up the callback thread if it is not already up.
257 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
259 struct svc_serv *serv = NULL;
260 struct svc_rqst *rqstp;
261 int (*callback_svc)(void *vrqstp);
262 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
265 int minorversion_setup;
267 mutex_lock(&nfs_callback_mutex);
268 if (cb_info->users++ || cb_info->task != NULL) {
269 nfs_callback_bc_serv(minorversion, xprt, cb_info);
272 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
278 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
279 serv, xprt, &rqstp, &callback_svc);
280 if (!minorversion_setup) {
281 /* v4.0 callback setup */
282 rqstp = nfs4_callback_up(serv);
283 callback_svc = nfs4_callback_svc;
287 ret = PTR_ERR(rqstp);
291 svc_sock_update_bufs(serv);
293 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
294 cb_info->serv = serv;
295 cb_info->rqst = rqstp;
296 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
297 if (IS_ERR(cb_info->task)) {
298 ret = PTR_ERR(cb_info->task);
299 svc_exit_thread(cb_info->rqst);
300 cb_info->rqst = NULL;
301 cb_info->task = NULL;
306 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
307 * svc_prepare_thread increments that. So we need to call svc_destroy
308 * on both success and failure so that the refcount is 1 when the
313 mutex_unlock(&nfs_callback_mutex);
316 dprintk("NFS: Couldn't create callback socket or server thread; "
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_exit_thread(cb_info->rqst);
334 cb_info->serv = NULL;
335 cb_info->rqst = NULL;
336 cb_info->task = NULL;
338 mutex_unlock(&nfs_callback_mutex);
341 static int check_gss_callback_principal(struct nfs_client *clp,
342 struct svc_rqst *rqstp)
344 struct rpc_clnt *r = clp->cl_rpcclient;
345 char *p = svc_gss_principal(rqstp);
348 * It might just be a normal user principal, in which case
349 * userspace won't bother to tell us the name at all.
354 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
356 if (memcmp(p, "nfs@", 4) != 0)
359 if (strcmp(p, r->cl_server) != 0)
364 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
366 struct nfs_client *clp;
367 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
370 /* Don't talk to strangers */
371 clp = nfs_find_client(svc_addr(rqstp), 4);
375 dprintk("%s: %s NFSv4 callback!\n", __func__,
376 svc_print_addr(rqstp, buf, sizeof(buf)));
378 switch (rqstp->rq_authop->flavour) {
380 if (rqstp->rq_proc != CB_NULL)
386 ret = check_gss_callback_principal(clp, rqstp);
396 * Define NFS4 callback program
398 static struct svc_version *nfs4_callback_version[] = {
399 [1] = &nfs4_callback_version1,
402 static struct svc_stat nfs4_callback_stats;
404 static struct svc_program nfs4_callback_program = {
405 .pg_prog = NFS4_CALLBACK, /* RPC service number */
406 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
407 .pg_vers = nfs4_callback_version, /* version table */
408 .pg_name = "NFSv4 callback", /* service name */
409 .pg_class = "nfs", /* authentication class */
410 .pg_stats = &nfs4_callback_stats,
411 .pg_authenticate = nfs_callback_authenticate,