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/errno.h>
16 #include <linux/mutex.h>
17 #include <linux/freezer.h>
18 #include <linux/kthread.h>
19 #include <linux/sunrpc/svcauth_gss.h>
20 #include <linux/sunrpc/bc_xprt.h>
22 #include <net/inet_sock.h>
29 #define NFSDBG_FACILITY NFSDBG_CALLBACK
31 struct nfs_callback_data
{
33 struct svc_serv
*serv
;
34 struct svc_rqst
*rqst
;
35 struct task_struct
*task
;
38 static struct nfs_callback_data nfs_callback_info
[NFS4_MAX_MINOR_VERSION
+ 1];
39 static DEFINE_MUTEX(nfs_callback_mutex
);
40 static struct svc_program nfs4_callback_program
;
42 static int nfs4_callback_up_net(struct svc_serv
*serv
, struct net
*net
)
45 struct nfs_net
*nn
= net_generic(net
, nfs_net_id
);
47 ret
= svc_create_xprt(serv
, "tcp", net
, PF_INET
,
48 nfs_callback_set_tcpport
, SVC_SOCK_ANONYMOUS
);
51 nn
->nfs_callback_tcpport
= ret
;
52 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
53 nn
->nfs_callback_tcpport
, PF_INET
, net
);
55 ret
= svc_create_xprt(serv
, "tcp", net
, PF_INET6
,
56 nfs_callback_set_tcpport
, SVC_SOCK_ANONYMOUS
);
58 nn
->nfs_callback_tcpport6
= ret
;
59 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
60 nn
->nfs_callback_tcpport6
, PF_INET6
, net
);
61 } else if (ret
!= -EAFNOSUPPORT
)
66 return (ret
) ? ret
: -ENOMEM
;
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
)
93 * Prepare to bring up the NFSv4 callback service
95 static struct svc_rqst
*
96 nfs4_callback_up(struct svc_serv
*serv
)
98 return svc_prepare_thread(serv
, &serv
->sv_pools
[0], NUMA_NO_NODE
);
101 #if defined(CONFIG_NFS_V4_1)
102 static int nfs41_callback_up_net(struct svc_serv
*serv
, struct net
*net
)
105 * Create an svc_sock for the back channel service that shares the
106 * fore channel connection.
107 * Returns the input port (0) and sets the svc_serv bc_xprt on success
109 return svc_create_xprt(serv
, "tcp-bc", net
, PF_INET
, 0,
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
)
154 struct svc_rqst
*rqstp
;
156 INIT_LIST_HEAD(&serv
->sv_cb_list
);
157 spin_lock_init(&serv
->sv_cb_lock
);
158 init_waitqueue_head(&serv
->sv_cb_waitq
);
159 rqstp
= svc_prepare_thread(serv
, &serv
->sv_pools
[0], NUMA_NO_NODE
);
161 svc_xprt_put(serv
->sv_bc_xprt
);
162 serv
->sv_bc_xprt
= NULL
;
164 dprintk("--> %s return %ld\n", __func__
,
165 IS_ERR(rqstp
) ? PTR_ERR(rqstp
) : 0);
169 static void nfs_minorversion_callback_svc_setup(struct svc_serv
*serv
,
170 struct svc_rqst
**rqstpp
, int (**callback_svc
)(void *vrqstp
))
172 *rqstpp
= nfs41_callback_up(serv
);
173 *callback_svc
= nfs41_callback_svc
;
176 static inline void nfs_callback_bc_serv(u32 minorversion
, struct rpc_xprt
*xprt
,
177 struct svc_serv
*serv
)
181 * Save the svc_serv in the transport so that it can
182 * be referenced when the session backchannel is initialized
184 xprt
->bc_serv
= serv
;
187 static int nfs41_callback_up_net(struct svc_serv
*serv
, struct net
*net
)
192 static void nfs_minorversion_callback_svc_setup(struct svc_serv
*serv
,
193 struct svc_rqst
**rqstpp
, int (**callback_svc
)(void *vrqstp
))
195 *rqstpp
= ERR_PTR(-ENOTSUPP
);
196 *callback_svc
= ERR_PTR(-ENOTSUPP
);
199 static inline void nfs_callback_bc_serv(u32 minorversion
, struct rpc_xprt
*xprt
,
200 struct svc_serv
*serv
)
203 #endif /* CONFIG_NFS_V4_1 */
205 static int nfs_callback_start_svc(int minorversion
, struct rpc_xprt
*xprt
,
206 struct svc_serv
*serv
)
208 struct svc_rqst
*rqstp
;
209 int (*callback_svc
)(void *vrqstp
);
210 struct nfs_callback_data
*cb_info
= &nfs_callback_info
[minorversion
];
214 nfs_callback_bc_serv(minorversion
, xprt
, serv
);
219 switch (minorversion
) {
221 /* v4.0 callback setup */
222 rqstp
= nfs4_callback_up(serv
);
223 callback_svc
= nfs4_callback_svc
;
226 nfs_minorversion_callback_svc_setup(serv
,
227 &rqstp
, &callback_svc
);
231 return PTR_ERR(rqstp
);
233 svc_sock_update_bufs(serv
);
235 sprintf(svc_name
, "nfsv4.%u-svc", minorversion
);
236 cb_info
->serv
= serv
;
237 cb_info
->rqst
= rqstp
;
238 cb_info
->task
= kthread_run(callback_svc
, cb_info
->rqst
, svc_name
);
239 if (IS_ERR(cb_info
->task
)) {
240 ret
= PTR_ERR(cb_info
->task
);
241 svc_exit_thread(cb_info
->rqst
);
242 cb_info
->rqst
= NULL
;
243 cb_info
->task
= NULL
;
246 dprintk("nfs_callback_up: service started\n");
250 static void nfs_callback_down_net(u32 minorversion
, struct svc_serv
*serv
, struct net
*net
)
252 struct nfs_net
*nn
= net_generic(net
, nfs_net_id
);
254 if (--nn
->cb_users
[minorversion
])
257 dprintk("NFS: destroy per-net callback data; net=%p\n", net
);
258 svc_shutdown_net(serv
, net
);
261 static int nfs_callback_up_net(int minorversion
, struct svc_serv
*serv
, struct net
*net
)
263 struct nfs_net
*nn
= net_generic(net
, nfs_net_id
);
266 if (nn
->cb_users
[minorversion
]++)
269 dprintk("NFS: create per-net callback data; net=%p\n", net
);
271 ret
= svc_bind(serv
, net
);
273 printk(KERN_WARNING
"NFS: bind callback service failed\n");
277 switch (minorversion
) {
279 ret
= nfs4_callback_up_net(serv
, net
);
282 ret
= nfs41_callback_up_net(serv
, net
);
285 printk(KERN_ERR
"NFS: unknown callback version: %d\n",
292 printk(KERN_ERR
"NFS: callback service start failed\n");
298 svc_rpcb_cleanup(serv
, net
);
300 dprintk("NFS: Couldn't create callback socket: err = %d; "
301 "net = %p\n", ret
, net
);
305 static struct svc_serv
*nfs_callback_create_svc(int minorversion
)
307 struct nfs_callback_data
*cb_info
= &nfs_callback_info
[minorversion
];
308 struct svc_serv
*serv
;
311 * Check whether we're already up and running.
315 * Note: increase service usage, because later in case of error
316 * svc_destroy() will be called.
318 svc_get(cb_info
->serv
);
319 return cb_info
->serv
;
323 * Sanity check: if there's no task,
324 * we should be the first user ...
327 printk(KERN_WARNING
"nfs_callback_create_svc: no kthread, %d users??\n",
330 serv
= svc_create(&nfs4_callback_program
, NFS4_CALLBACK_BUFSIZE
, NULL
);
332 printk(KERN_ERR
"nfs_callback_create_svc: create service failed\n");
333 return ERR_PTR(-ENOMEM
);
335 /* As there is only one thread we need to over-ride the
336 * default maximum of 80 connections
338 serv
->sv_maxconn
= 1024;
339 dprintk("nfs_callback_create_svc: service created\n");
344 * Bring up the callback thread if it is not already up.
346 int nfs_callback_up(u32 minorversion
, struct rpc_xprt
*xprt
)
348 struct svc_serv
*serv
;
349 struct nfs_callback_data
*cb_info
= &nfs_callback_info
[minorversion
];
351 struct net
*net
= xprt
->xprt_net
;
353 mutex_lock(&nfs_callback_mutex
);
355 serv
= nfs_callback_create_svc(minorversion
);
361 ret
= nfs_callback_up_net(minorversion
, serv
, net
);
365 ret
= nfs_callback_start_svc(minorversion
, xprt
, serv
);
371 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
372 * svc_prepare_thread increments that. So we need to call svc_destroy
373 * on both success and failure so that the refcount is 1 when the
379 mutex_unlock(&nfs_callback_mutex
);
383 nfs_callback_down_net(minorversion
, serv
, net
);
384 dprintk("NFS: Couldn't create server thread; err = %d\n", ret
);
389 * Kill the callback thread if it's no longer being used.
391 void nfs_callback_down(int minorversion
, struct net
*net
)
393 struct nfs_callback_data
*cb_info
= &nfs_callback_info
[minorversion
];
395 mutex_lock(&nfs_callback_mutex
);
396 nfs_callback_down_net(minorversion
, cb_info
->serv
, net
);
398 if (cb_info
->users
== 0 && cb_info
->task
!= NULL
) {
399 kthread_stop(cb_info
->task
);
400 dprintk("nfs_callback_down: service stopped\n");
401 svc_exit_thread(cb_info
->rqst
);
402 dprintk("nfs_callback_down: service destroyed\n");
403 cb_info
->serv
= NULL
;
404 cb_info
->rqst
= NULL
;
405 cb_info
->task
= NULL
;
407 mutex_unlock(&nfs_callback_mutex
);
410 /* Boolean check of RPC_AUTH_GSS principal */
412 check_gss_callback_principal(struct nfs_client
*clp
, struct svc_rqst
*rqstp
)
414 char *p
= rqstp
->rq_cred
.cr_principal
;
416 if (rqstp
->rq_authop
->flavour
!= RPC_AUTH_GSS
)
419 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
420 if (clp
->cl_minorversion
!= 0)
423 * It might just be a normal user principal, in which case
424 * userspace won't bother to tell us the name at all.
429 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
431 if (memcmp(p
, "nfs@", 4) != 0)
434 if (strcmp(p
, clp
->cl_hostname
) != 0)
440 * pg_authenticate method for nfsv4 callback threads.
442 * The authflavor has been negotiated, so an incorrect flavor is a server
443 * bug. Drop packets with incorrect authflavor.
445 * All other checking done after NFS decoding where the nfs_client can be
446 * found in nfs4_callback_compound
448 static int nfs_callback_authenticate(struct svc_rqst
*rqstp
)
450 switch (rqstp
->rq_authop
->flavour
) {
452 if (rqstp
->rq_proc
!= CB_NULL
)
456 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
457 if (svc_is_backchannel(rqstp
))
464 * Define NFS4 callback program
466 static struct svc_version
*nfs4_callback_version
[] = {
467 [1] = &nfs4_callback_version1
,
468 [4] = &nfs4_callback_version4
,
471 static struct svc_stat nfs4_callback_stats
;
473 static struct svc_program nfs4_callback_program
= {
474 .pg_prog
= NFS4_CALLBACK
, /* RPC service number */
475 .pg_nvers
= ARRAY_SIZE(nfs4_callback_version
), /* Number of entries */
476 .pg_vers
= nfs4_callback_version
, /* version table */
477 .pg_name
= "NFSv4 callback", /* service name */
478 .pg_class
= "nfs", /* authentication class */
479 .pg_stats
= &nfs4_callback_stats
,
480 .pg_authenticate
= nfs_callback_authenticate
,