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;
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 static const int nfs_set_port_min = 0;
47 static const int nfs_set_port_max = 65535;
49 static int param_set_port(const char *val, struct kernel_param *kp)
52 int num = simple_strtol(val, &endp, 0);
53 if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
55 *((int *)kp->arg) = num;
59 module_param_call(callback_tcpport, param_set_port, param_get_int,
60 &nfs_callback_set_tcpport, 0644);
63 * This is the callback kernel thread.
66 nfs4_callback_svc(void *vrqstp)
69 struct svc_rqst *rqstp = vrqstp;
74 * FIXME: do we really need to run this under the BKL? If so, please
75 * add a comment about what it's intended to protect.
78 while (!kthread_should_stop()) {
80 * Listen for a request on the socket
82 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
83 if (err == -EAGAIN || err == -EINTR) {
89 printk(KERN_WARNING "%s: unexpected error "
90 "from svc_recv (%d)\n", __func__, err);
93 schedule_timeout_uninterruptible(HZ);
104 * Prepare to bring up the NFSv4 callback service
107 nfs4_callback_up(struct svc_serv *serv)
111 ret = svc_create_xprt(serv, "tcp", PF_INET,
112 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
115 nfs_callback_tcpport = ret;
116 dprintk("NFS: Callback listener port = %u (af %u)\n",
117 nfs_callback_tcpport, PF_INET);
119 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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)
128 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
130 return svc_prepare_thread(serv, &serv->sv_pools[0]);
138 #if defined(CONFIG_NFS_V4_1)
140 * The callback service for NFSv4.1 callbacks
143 nfs41_callback_svc(void *vrqstp)
145 struct svc_rqst *rqstp = vrqstp;
146 struct svc_serv *serv = rqstp->rq_server;
147 struct rpc_rqst *req;
154 * FIXME: do we really need to run this under the BKL? If so, please
155 * add a comment about what it's intended to protect.
158 while (!kthread_should_stop()) {
159 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
160 spin_lock_bh(&serv->sv_cb_lock);
161 if (!list_empty(&serv->sv_cb_list)) {
162 req = list_first_entry(&serv->sv_cb_list,
163 struct rpc_rqst, rq_bc_list);
164 list_del(&req->rq_bc_list);
165 spin_unlock_bh(&serv->sv_cb_lock);
166 dprintk("Invoking bc_svc_process()\n");
167 error = bc_svc_process(serv, req, rqstp);
168 dprintk("bc_svc_process() returned w/ error code= %d\n",
171 spin_unlock_bh(&serv->sv_cb_lock);
174 finish_wait(&serv->sv_cb_waitq, &wq);
177 nfs_callback_info.task = NULL;
178 svc_exit_thread(rqstp);
183 * Bring up the NFSv4.1 callback service
186 nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
188 struct svc_xprt *bc_xprt;
189 struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
191 dprintk("--> %s\n", __func__);
192 /* Create a svc_sock for the service */
193 bc_xprt = svc_sock_create(serv, xprt->prot);
198 * Save the svc_serv in the transport so that it can
199 * be referenced when the session backchannel is initialized
201 serv->bc_xprt = bc_xprt;
202 xprt->bc_serv = serv;
204 INIT_LIST_HEAD(&serv->sv_cb_list);
205 spin_lock_init(&serv->sv_cb_lock);
206 init_waitqueue_head(&serv->sv_cb_waitq);
207 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
209 svc_sock_destroy(bc_xprt);
211 dprintk("--> %s return %p\n", __func__, rqstp);
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);
256 int minorversion_setup;
258 mutex_lock(&nfs_callback_mutex);
259 if (nfs_callback_info.users++ || nfs_callback_info.task != NULL) {
260 nfs_callback_bc_serv(minorversion, xprt, &nfs_callback_info);
263 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
269 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
270 serv, xprt, &rqstp, &callback_svc);
271 if (!minorversion_setup) {
272 /* v4.0 callback setup */
273 rqstp = nfs4_callback_up(serv);
274 callback_svc = nfs4_callback_svc;
278 ret = PTR_ERR(rqstp);
282 svc_sock_update_bufs(serv);
284 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
285 nfs_callback_info.serv = serv;
286 nfs_callback_info.rqst = rqstp;
287 nfs_callback_info.task = kthread_run(callback_svc,
288 nfs_callback_info.rqst,
290 if (IS_ERR(nfs_callback_info.task)) {
291 ret = PTR_ERR(nfs_callback_info.task);
292 svc_exit_thread(nfs_callback_info.rqst);
293 nfs_callback_info.serv = NULL;
294 nfs_callback_info.rqst = NULL;
295 nfs_callback_info.task = NULL;
300 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
301 * svc_prepare_thread increments that. So we need to call svc_destroy
302 * on both success and failure so that the refcount is 1 when the
307 mutex_unlock(&nfs_callback_mutex);
310 dprintk("NFS: Couldn't create callback socket or server thread; "
312 nfs_callback_info.users--;
317 * Kill the callback thread if it's no longer being used.
319 void nfs_callback_down(void)
321 mutex_lock(&nfs_callback_mutex);
322 nfs_callback_info.users--;
323 if (nfs_callback_info.users == 0 && nfs_callback_info.task != NULL) {
324 kthread_stop(nfs_callback_info.task);
325 svc_exit_thread(nfs_callback_info.rqst);
326 nfs_callback_info.serv = NULL;
327 nfs_callback_info.rqst = NULL;
328 nfs_callback_info.task = NULL;
330 mutex_unlock(&nfs_callback_mutex);
333 static int check_gss_callback_principal(struct nfs_client *clp,
334 struct svc_rqst *rqstp)
336 struct rpc_clnt *r = clp->cl_rpcclient;
337 char *p = svc_gss_principal(rqstp);
340 * It might just be a normal user principal, in which case
341 * userspace won't bother to tell us the name at all.
346 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
348 if (memcmp(p, "nfs@", 4) != 0)
351 if (strcmp(p, r->cl_server) != 0)
356 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
358 struct nfs_client *clp;
359 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
362 /* Don't talk to strangers */
363 clp = nfs_find_client(svc_addr(rqstp), 4);
367 dprintk("%s: %s NFSv4 callback!\n", __func__,
368 svc_print_addr(rqstp, buf, sizeof(buf)));
370 switch (rqstp->rq_authop->flavour) {
372 if (rqstp->rq_proc != CB_NULL)
378 ret = check_gss_callback_principal(clp, rqstp);
388 * Define NFS4 callback program
390 static struct svc_version *nfs4_callback_version[] = {
391 [1] = &nfs4_callback_version1,
394 static struct svc_stat nfs4_callback_stats;
396 static struct svc_program nfs4_callback_program = {
397 .pg_prog = NFS4_CALLBACK, /* RPC service number */
398 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
399 .pg_vers = nfs4_callback_version, /* version table */
400 .pg_name = "NFSv4 callback", /* service name */
401 .pg_class = "nfs", /* authentication class */
402 .pg_stats = &nfs4_callback_stats,
403 .pg_authenticate = nfs_callback_authenticate,