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 short nfs_callback_tcpport6
;
43 * This is the NFSv4 callback kernel thread.
46 nfs4_callback_svc(void *vrqstp
)
49 struct svc_rqst
*rqstp
= vrqstp
;
53 while (!kthread_should_stop()) {
55 * Listen for a request on the socket
57 err
= svc_recv(rqstp
, MAX_SCHEDULE_TIMEOUT
);
58 if (err
== -EAGAIN
|| err
== -EINTR
) {
64 printk(KERN_WARNING
"NFS: %s: unexpected error "
65 "from svc_recv (%d)\n", __func__
, err
);
68 schedule_timeout_uninterruptible(HZ
);
78 * Prepare to bring up the NFSv4 callback service
80 static struct svc_rqst
*
81 nfs4_callback_up(struct svc_serv
*serv
, struct rpc_xprt
*xprt
)
85 ret
= svc_create_xprt(serv
, "tcp", &init_net
, PF_INET
,
86 nfs_callback_set_tcpport
, SVC_SOCK_ANONYMOUS
);
89 nfs_callback_tcpport
= ret
;
90 dprintk("NFS: Callback listener port = %u (af %u)\n",
91 nfs_callback_tcpport
, PF_INET
);
93 ret
= svc_create_xprt(serv
, "tcp", &init_net
, PF_INET6
,
94 nfs_callback_set_tcpport
, SVC_SOCK_ANONYMOUS
);
96 nfs_callback_tcpport6
= ret
;
97 dprintk("NFS: Callback listener port = %u (af %u)\n",
98 nfs_callback_tcpport6
, PF_INET6
);
99 } else if (ret
== -EAFNOSUPPORT
)
104 return svc_prepare_thread(serv
, &serv
->sv_pools
[0], NUMA_NO_NODE
);
112 #if defined(CONFIG_NFS_V4_1)
114 * The callback service for NFSv4.1 callbacks
117 nfs41_callback_svc(void *vrqstp
)
119 struct svc_rqst
*rqstp
= vrqstp
;
120 struct svc_serv
*serv
= rqstp
->rq_server
;
121 struct rpc_rqst
*req
;
127 while (!kthread_should_stop()) {
128 prepare_to_wait(&serv
->sv_cb_waitq
, &wq
, TASK_INTERRUPTIBLE
);
129 spin_lock_bh(&serv
->sv_cb_lock
);
130 if (!list_empty(&serv
->sv_cb_list
)) {
131 req
= list_first_entry(&serv
->sv_cb_list
,
132 struct rpc_rqst
, rq_bc_list
);
133 list_del(&req
->rq_bc_list
);
134 spin_unlock_bh(&serv
->sv_cb_lock
);
135 dprintk("Invoking bc_svc_process()\n");
136 error
= bc_svc_process(serv
, req
, rqstp
);
137 dprintk("bc_svc_process() returned w/ error code= %d\n",
140 spin_unlock_bh(&serv
->sv_cb_lock
);
143 finish_wait(&serv
->sv_cb_waitq
, &wq
);
149 * Bring up the NFSv4.1 callback service
151 static struct svc_rqst
*
152 nfs41_callback_up(struct svc_serv
*serv
, struct rpc_xprt
*xprt
)
154 struct svc_rqst
*rqstp
;
158 * Create an svc_sock for the back channel service that shares the
159 * fore channel connection.
160 * Returns the input port (0) and sets the svc_serv bc_xprt on success
162 ret
= svc_create_xprt(serv
, "tcp-bc", &init_net
, PF_INET
, 0,
165 rqstp
= ERR_PTR(ret
);
170 * Save the svc_serv in the transport so that it can
171 * be referenced when the session backchannel is initialized
173 xprt
->bc_serv
= serv
;
175 INIT_LIST_HEAD(&serv
->sv_cb_list
);
176 spin_lock_init(&serv
->sv_cb_lock
);
177 init_waitqueue_head(&serv
->sv_cb_waitq
);
178 rqstp
= svc_prepare_thread(serv
, &serv
->sv_pools
[0], NUMA_NO_NODE
);
180 svc_xprt_put(serv
->sv_bc_xprt
);
181 serv
->sv_bc_xprt
= NULL
;
184 dprintk("--> %s return %ld\n", __func__
,
185 IS_ERR(rqstp
) ? PTR_ERR(rqstp
) : 0);
189 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion
,
190 struct svc_serv
*serv
, struct rpc_xprt
*xprt
,
191 struct svc_rqst
**rqstpp
, int (**callback_svc
)(void *vrqstp
))
194 *rqstpp
= nfs41_callback_up(serv
, xprt
);
195 *callback_svc
= nfs41_callback_svc
;
200 static inline void nfs_callback_bc_serv(u32 minorversion
, struct rpc_xprt
*xprt
,
201 struct nfs_callback_data
*cb_info
)
204 xprt
->bc_serv
= cb_info
->serv
;
207 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion
,
208 struct svc_serv
*serv
, struct rpc_xprt
*xprt
,
209 struct svc_rqst
**rqstpp
, int (**callback_svc
)(void *vrqstp
))
214 static inline void nfs_callback_bc_serv(u32 minorversion
, struct rpc_xprt
*xprt
,
215 struct nfs_callback_data
*cb_info
)
218 #endif /* CONFIG_NFS_V4_1 */
221 * Bring up the callback thread if it is not already up.
223 int nfs_callback_up(u32 minorversion
, struct rpc_xprt
*xprt
)
225 struct svc_serv
*serv
= NULL
;
226 struct svc_rqst
*rqstp
;
227 int (*callback_svc
)(void *vrqstp
);
228 struct nfs_callback_data
*cb_info
= &nfs_callback_info
[minorversion
];
231 int minorversion_setup
;
232 struct net
*net
= &init_net
;
234 mutex_lock(&nfs_callback_mutex
);
235 if (cb_info
->users
++ || cb_info
->task
!= NULL
) {
236 nfs_callback_bc_serv(minorversion
, xprt
, cb_info
);
239 serv
= svc_create(&nfs4_callback_program
, NFS4_CALLBACK_BUFSIZE
, NULL
);
244 /* As there is only one thread we need to over-ride the
245 * default maximum of 80 connections
247 serv
->sv_maxconn
= 1024;
249 ret
= svc_bind(serv
, net
);
251 printk(KERN_WARNING
"NFS: bind callback service failed\n");
255 minorversion_setup
= nfs_minorversion_callback_svc_setup(minorversion
,
256 serv
, xprt
, &rqstp
, &callback_svc
);
257 if (!minorversion_setup
) {
258 /* v4.0 callback setup */
259 rqstp
= nfs4_callback_up(serv
, xprt
);
260 callback_svc
= nfs4_callback_svc
;
264 ret
= PTR_ERR(rqstp
);
268 svc_sock_update_bufs(serv
);
270 sprintf(svc_name
, "nfsv4.%u-svc", minorversion
);
271 cb_info
->serv
= serv
;
272 cb_info
->rqst
= rqstp
;
273 cb_info
->task
= kthread_run(callback_svc
, cb_info
->rqst
, svc_name
);
274 if (IS_ERR(cb_info
->task
)) {
275 ret
= PTR_ERR(cb_info
->task
);
276 svc_exit_thread(cb_info
->rqst
);
277 cb_info
->rqst
= NULL
;
278 cb_info
->task
= NULL
;
283 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
284 * svc_prepare_thread increments that. So we need to call svc_destroy
285 * on both success and failure so that the refcount is 1 when the
290 mutex_unlock(&nfs_callback_mutex
);
293 dprintk("NFS: Couldn't create callback socket or server thread; "
297 svc_shutdown_net(serv
, net
);
302 * Kill the callback thread if it's no longer being used.
304 void nfs_callback_down(int minorversion
)
306 struct nfs_callback_data
*cb_info
= &nfs_callback_info
[minorversion
];
308 mutex_lock(&nfs_callback_mutex
);
310 if (cb_info
->users
== 0 && cb_info
->task
!= NULL
) {
311 kthread_stop(cb_info
->task
);
312 svc_shutdown_net(cb_info
->serv
, &init_net
);
313 svc_exit_thread(cb_info
->rqst
);
314 cb_info
->serv
= NULL
;
315 cb_info
->rqst
= NULL
;
316 cb_info
->task
= NULL
;
318 mutex_unlock(&nfs_callback_mutex
);
321 /* Boolean check of RPC_AUTH_GSS principal */
323 check_gss_callback_principal(struct nfs_client
*clp
, struct svc_rqst
*rqstp
)
325 char *p
= rqstp
->rq_cred
.cr_principal
;
327 if (rqstp
->rq_authop
->flavour
!= RPC_AUTH_GSS
)
330 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
331 if (clp
->cl_minorversion
!= 0)
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
, clp
->cl_hostname
) != 0)
351 * pg_authenticate method for nfsv4 callback threads.
353 * The authflavor has been negotiated, so an incorrect flavor is a server
354 * bug. Drop packets with incorrect authflavor.
356 * All other checking done after NFS decoding where the nfs_client can be
357 * found in nfs4_callback_compound
359 static int nfs_callback_authenticate(struct svc_rqst
*rqstp
)
361 switch (rqstp
->rq_authop
->flavour
) {
363 if (rqstp
->rq_proc
!= CB_NULL
)
367 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
368 if (svc_is_backchannel(rqstp
))
375 * Define NFS4 callback program
377 static struct svc_version
*nfs4_callback_version
[] = {
378 [1] = &nfs4_callback_version1
,
379 [4] = &nfs4_callback_version4
,
382 static struct svc_stat nfs4_callback_stats
;
384 static struct svc_program nfs4_callback_program
= {
385 .pg_prog
= NFS4_CALLBACK
, /* RPC service number */
386 .pg_nvers
= ARRAY_SIZE(nfs4_callback_version
), /* Number of entries */
387 .pg_vers
= nfs4_callback_version
, /* version table */
388 .pg_name
= "NFSv4 callback", /* service name */
389 .pg_class
= "nfs", /* authentication class */
390 .pg_stats
= &nfs4_callback_stats
,
391 .pg_authenticate
= nfs_callback_authenticate
,