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1/*
2 * linux/fs/nfs/callback.c
3 *
4 * Copyright (C) 2004 Trond Myklebust
5 *
6 * NFSv4 callback handling
7 */
8
9#include <linux/completion.h>
10#include <linux/ip.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>
21
22#include <net/inet_sock.h>
23
24#include "nfs4_fs.h"
25#include "callback.h"
26#include "internal.h"
27#include "netns.h"
28
29#define NFSDBG_FACILITY NFSDBG_CALLBACK
30
31struct nfs_callback_data {
32 unsigned int users;
33 struct svc_serv *serv;
34 struct svc_rqst *rqst;
35 struct task_struct *task;
36};
37
38static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
39static DEFINE_MUTEX(nfs_callback_mutex);
40static struct svc_program nfs4_callback_program;
41
42static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
43{
44 int ret;
45 struct nfs_net *nn = net_generic(net, nfs_net_id);
46
47 ret = svc_create_xprt(serv, "tcp", net, PF_INET,
48 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
49 if (ret <= 0)
50 goto out_err;
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);
54
55 ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
56 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
57 if (ret > 0) {
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)
62 goto out_err;
63 return 0;
64
65out_err:
66 return (ret) ? ret : -ENOMEM;
67}
68
69/*
70 * This is the NFSv4 callback kernel thread.
71 */
72static int
73nfs4_callback_svc(void *vrqstp)
74{
75 int err;
76 struct svc_rqst *rqstp = vrqstp;
77
78 set_freezable();
79
80 while (!kthread_should_stop()) {
81 /*
82 * Listen for a request on the socket
83 */
84 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
85 if (err == -EAGAIN || err == -EINTR)
86 continue;
87 svc_process(rqstp);
88 }
89 return 0;
90}
91
92/*
93 * Prepare to bring up the NFSv4 callback service
94 */
95static struct svc_rqst *
96nfs4_callback_up(struct svc_serv *serv)
97{
98 return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
99}
100
101#if defined(CONFIG_NFS_V4_1)
102/*
103 * The callback service for NFSv4.1 callbacks
104 */
105static int
106nfs41_callback_svc(void *vrqstp)
107{
108 struct svc_rqst *rqstp = vrqstp;
109 struct svc_serv *serv = rqstp->rq_server;
110 struct rpc_rqst *req;
111 int error;
112 DEFINE_WAIT(wq);
113
114 set_freezable();
115
116 while (!kthread_should_stop()) {
117 if (try_to_freeze())
118 continue;
119
120 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
121 spin_lock_bh(&serv->sv_cb_lock);
122 if (!list_empty(&serv->sv_cb_list)) {
123 req = list_first_entry(&serv->sv_cb_list,
124 struct rpc_rqst, rq_bc_list);
125 list_del(&req->rq_bc_list);
126 spin_unlock_bh(&serv->sv_cb_lock);
127 finish_wait(&serv->sv_cb_waitq, &wq);
128 dprintk("Invoking bc_svc_process()\n");
129 error = bc_svc_process(serv, req, rqstp);
130 dprintk("bc_svc_process() returned w/ error code= %d\n",
131 error);
132 } else {
133 spin_unlock_bh(&serv->sv_cb_lock);
134 schedule();
135 finish_wait(&serv->sv_cb_waitq, &wq);
136 }
137 flush_signals(current);
138 }
139 return 0;
140}
141
142/*
143 * Bring up the NFSv4.1 callback service
144 */
145static struct svc_rqst *
146nfs41_callback_up(struct svc_serv *serv)
147{
148 struct svc_rqst *rqstp;
149
150 INIT_LIST_HEAD(&serv->sv_cb_list);
151 spin_lock_init(&serv->sv_cb_lock);
152 init_waitqueue_head(&serv->sv_cb_waitq);
153 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
154 dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp));
155 return rqstp;
156}
157
158static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
159 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
160{
161 *rqstpp = nfs41_callback_up(serv);
162 *callback_svc = nfs41_callback_svc;
163}
164
165static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
166 struct svc_serv *serv)
167{
168 if (minorversion)
169 /*
170 * Save the svc_serv in the transport so that it can
171 * be referenced when the session backchannel is initialized
172 */
173 xprt->bc_serv = serv;
174}
175#else
176static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
177 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
178{
179 *rqstpp = ERR_PTR(-ENOTSUPP);
180 *callback_svc = ERR_PTR(-ENOTSUPP);
181}
182
183static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
184 struct svc_serv *serv)
185{
186}
187#endif /* CONFIG_NFS_V4_1 */
188
189static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
190 struct svc_serv *serv)
191{
192 struct svc_rqst *rqstp;
193 int (*callback_svc)(void *vrqstp);
194 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
195 int ret;
196
197 nfs_callback_bc_serv(minorversion, xprt, serv);
198
199 if (cb_info->task)
200 return 0;
201
202 switch (minorversion) {
203 case 0:
204 /* v4.0 callback setup */
205 rqstp = nfs4_callback_up(serv);
206 callback_svc = nfs4_callback_svc;
207 break;
208 default:
209 nfs_minorversion_callback_svc_setup(serv,
210 &rqstp, &callback_svc);
211 }
212
213 if (IS_ERR(rqstp))
214 return PTR_ERR(rqstp);
215
216 svc_sock_update_bufs(serv);
217
218 cb_info->serv = serv;
219 cb_info->rqst = rqstp;
220 cb_info->task = kthread_create(callback_svc, cb_info->rqst,
221 "nfsv4.%u-svc", minorversion);
222 if (IS_ERR(cb_info->task)) {
223 ret = PTR_ERR(cb_info->task);
224 svc_exit_thread(cb_info->rqst);
225 cb_info->rqst = NULL;
226 cb_info->task = NULL;
227 return ret;
228 }
229 rqstp->rq_task = cb_info->task;
230 wake_up_process(cb_info->task);
231 dprintk("nfs_callback_up: service started\n");
232 return 0;
233}
234
235static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
236{
237 struct nfs_net *nn = net_generic(net, nfs_net_id);
238
239 if (--nn->cb_users[minorversion])
240 return;
241
242 dprintk("NFS: destroy per-net callback data; net=%p\n", net);
243 svc_shutdown_net(serv, net);
244}
245
246static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
247 struct net *net, struct rpc_xprt *xprt)
248{
249 struct nfs_net *nn = net_generic(net, nfs_net_id);
250 int ret;
251
252 if (nn->cb_users[minorversion]++)
253 return 0;
254
255 dprintk("NFS: create per-net callback data; net=%p\n", net);
256
257 ret = svc_bind(serv, net);
258 if (ret < 0) {
259 printk(KERN_WARNING "NFS: bind callback service failed\n");
260 goto err_bind;
261 }
262
263 ret = -EPROTONOSUPPORT;
264 if (minorversion == 0)
265 ret = nfs4_callback_up_net(serv, net);
266 else if (xprt->ops->bc_up)
267 ret = xprt->ops->bc_up(serv, net);
268
269 if (ret < 0) {
270 printk(KERN_ERR "NFS: callback service start failed\n");
271 goto err_socks;
272 }
273 return 0;
274
275err_socks:
276 svc_rpcb_cleanup(serv, net);
277err_bind:
278 dprintk("NFS: Couldn't create callback socket: err = %d; "
279 "net = %p\n", ret, net);
280 return ret;
281}
282
283static struct svc_serv_ops nfs_cb_sv_ops = {
284 .svo_enqueue_xprt = svc_xprt_do_enqueue,
285};
286
287static struct svc_serv *nfs_callback_create_svc(int minorversion)
288{
289 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
290 struct svc_serv *serv;
291
292 /*
293 * Check whether we're already up and running.
294 */
295 if (cb_info->task) {
296 /*
297 * Note: increase service usage, because later in case of error
298 * svc_destroy() will be called.
299 */
300 svc_get(cb_info->serv);
301 return cb_info->serv;
302 }
303
304 /*
305 * Sanity check: if there's no task,
306 * we should be the first user ...
307 */
308 if (cb_info->users)
309 printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
310 cb_info->users);
311
312 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, &nfs_cb_sv_ops);
313 if (!serv) {
314 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
315 return ERR_PTR(-ENOMEM);
316 }
317 /* As there is only one thread we need to over-ride the
318 * default maximum of 80 connections
319 */
320 serv->sv_maxconn = 1024;
321 dprintk("nfs_callback_create_svc: service created\n");
322 return serv;
323}
324
325/*
326 * Bring up the callback thread if it is not already up.
327 */
328int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
329{
330 struct svc_serv *serv;
331 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
332 int ret;
333 struct net *net = xprt->xprt_net;
334
335 mutex_lock(&nfs_callback_mutex);
336
337 serv = nfs_callback_create_svc(minorversion);
338 if (IS_ERR(serv)) {
339 ret = PTR_ERR(serv);
340 goto err_create;
341 }
342
343 ret = nfs_callback_up_net(minorversion, serv, net, xprt);
344 if (ret < 0)
345 goto err_net;
346
347 ret = nfs_callback_start_svc(minorversion, xprt, serv);
348 if (ret < 0)
349 goto err_start;
350
351 cb_info->users++;
352 /*
353 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
354 * svc_prepare_thread increments that. So we need to call svc_destroy
355 * on both success and failure so that the refcount is 1 when the
356 * thread exits.
357 */
358err_net:
359 svc_destroy(serv);
360err_create:
361 mutex_unlock(&nfs_callback_mutex);
362 return ret;
363
364err_start:
365 nfs_callback_down_net(minorversion, serv, net);
366 dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
367 goto err_net;
368}
369
370/*
371 * Kill the callback thread if it's no longer being used.
372 */
373void nfs_callback_down(int minorversion, struct net *net)
374{
375 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
376
377 mutex_lock(&nfs_callback_mutex);
378 nfs_callback_down_net(minorversion, cb_info->serv, net);
379 cb_info->users--;
380 if (cb_info->users == 0 && cb_info->task != NULL) {
381 kthread_stop(cb_info->task);
382 dprintk("nfs_callback_down: service stopped\n");
383 svc_exit_thread(cb_info->rqst);
384 dprintk("nfs_callback_down: service destroyed\n");
385 cb_info->serv = NULL;
386 cb_info->rqst = NULL;
387 cb_info->task = NULL;
388 }
389 mutex_unlock(&nfs_callback_mutex);
390}
391
392/* Boolean check of RPC_AUTH_GSS principal */
393int
394check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
395{
396 char *p = rqstp->rq_cred.cr_principal;
397
398 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
399 return 1;
400
401 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
402 if (clp->cl_minorversion != 0)
403 return 0;
404 /*
405 * It might just be a normal user principal, in which case
406 * userspace won't bother to tell us the name at all.
407 */
408 if (p == NULL)
409 return 0;
410
411 /*
412 * Did we get the acceptor from userland during the SETCLIENID
413 * negotiation?
414 */
415 if (clp->cl_acceptor)
416 return !strcmp(p, clp->cl_acceptor);
417
418 /*
419 * Otherwise try to verify it using the cl_hostname. Note that this
420 * doesn't work if a non-canonical hostname was used in the devname.
421 */
422
423 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
424
425 if (memcmp(p, "nfs@", 4) != 0)
426 return 0;
427 p += 4;
428 if (strcmp(p, clp->cl_hostname) != 0)
429 return 0;
430 return 1;
431}
432
433/*
434 * pg_authenticate method for nfsv4 callback threads.
435 *
436 * The authflavor has been negotiated, so an incorrect flavor is a server
437 * bug. Deny packets with incorrect authflavor.
438 *
439 * All other checking done after NFS decoding where the nfs_client can be
440 * found in nfs4_callback_compound
441 */
442static int nfs_callback_authenticate(struct svc_rqst *rqstp)
443{
444 switch (rqstp->rq_authop->flavour) {
445 case RPC_AUTH_NULL:
446 if (rqstp->rq_proc != CB_NULL)
447 return SVC_DENIED;
448 break;
449 case RPC_AUTH_GSS:
450 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
451 if (svc_is_backchannel(rqstp))
452 return SVC_DENIED;
453 }
454 return SVC_OK;
455}
456
457/*
458 * Define NFS4 callback program
459 */
460static struct svc_version *nfs4_callback_version[] = {
461 [1] = &nfs4_callback_version1,
462 [4] = &nfs4_callback_version4,
463};
464
465static struct svc_stat nfs4_callback_stats;
466
467static struct svc_program nfs4_callback_program = {
468 .pg_prog = NFS4_CALLBACK, /* RPC service number */
469 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
470 .pg_vers = nfs4_callback_version, /* version table */
471 .pg_name = "NFSv4 callback", /* service name */
472 .pg_class = "nfs", /* authentication class */
473 .pg_stats = &nfs4_callback_stats,
474 .pg_authenticate = nfs_callback_authenticate,
475};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/nfs/callback.c
4 *
5 * Copyright (C) 2004 Trond Myklebust
6 *
7 * NFSv4 callback handling
8 */
9
10#include <linux/completion.h>
11#include <linux/ip.h>
12#include <linux/module.h>
13#include <linux/sched/signal.h>
14#include <linux/sunrpc/svc.h>
15#include <linux/sunrpc/svcsock.h>
16#include <linux/nfs_fs.h>
17#include <linux/errno.h>
18#include <linux/mutex.h>
19#include <linux/freezer.h>
20#include <linux/sunrpc/svcauth_gss.h>
21#include <linux/sunrpc/bc_xprt.h>
22
23#include <net/inet_sock.h>
24
25#include "nfs4_fs.h"
26#include "callback.h"
27#include "internal.h"
28#include "netns.h"
29
30#define NFSDBG_FACILITY NFSDBG_CALLBACK
31
32struct nfs_callback_data {
33 unsigned int users;
34 struct svc_serv *serv;
35};
36
37static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
38static DEFINE_MUTEX(nfs_callback_mutex);
39static struct svc_program nfs4_callback_program;
40
41static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
42{
43 const struct cred *cred = current_cred();
44 int ret;
45 struct nfs_net *nn = net_generic(net, nfs_net_id);
46
47 ret = svc_xprt_create(serv, "tcp", net, PF_INET,
48 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS,
49 cred);
50 if (ret <= 0)
51 goto out_err;
52 nn->nfs_callback_tcpport = ret;
53 dprintk("NFS: Callback listener port = %u (af %u, net %x)\n",
54 nn->nfs_callback_tcpport, PF_INET, net->ns.inum);
55
56 ret = svc_xprt_create(serv, "tcp", net, PF_INET6,
57 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS,
58 cred);
59 if (ret > 0) {
60 nn->nfs_callback_tcpport6 = ret;
61 dprintk("NFS: Callback listener port = %u (af %u, net %x)\n",
62 nn->nfs_callback_tcpport6, PF_INET6, net->ns.inum);
63 } else if (ret != -EAFNOSUPPORT)
64 goto out_err;
65 return 0;
66
67out_err:
68 return (ret) ? ret : -ENOMEM;
69}
70
71/*
72 * This is the NFSv4 callback kernel thread.
73 */
74static int
75nfs4_callback_svc(void *vrqstp)
76{
77 int err;
78 struct svc_rqst *rqstp = vrqstp;
79
80 set_freezable();
81
82 while (!kthread_freezable_should_stop(NULL)) {
83
84 if (signal_pending(current))
85 flush_signals(current);
86 /*
87 * Listen for a request on the socket
88 */
89 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
90 if (err == -EAGAIN || err == -EINTR)
91 continue;
92 svc_process(rqstp);
93 }
94
95 svc_exit_thread(rqstp);
96 return 0;
97}
98
99#if defined(CONFIG_NFS_V4_1)
100/*
101 * The callback service for NFSv4.1 callbacks
102 */
103static int
104nfs41_callback_svc(void *vrqstp)
105{
106 struct svc_rqst *rqstp = vrqstp;
107 struct svc_serv *serv = rqstp->rq_server;
108 struct rpc_rqst *req;
109 int error;
110 DEFINE_WAIT(wq);
111
112 set_freezable();
113
114 while (!kthread_freezable_should_stop(NULL)) {
115
116 if (signal_pending(current))
117 flush_signals(current);
118
119 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
120 spin_lock_bh(&serv->sv_cb_lock);
121 if (!list_empty(&serv->sv_cb_list)) {
122 req = list_first_entry(&serv->sv_cb_list,
123 struct rpc_rqst, rq_bc_list);
124 list_del(&req->rq_bc_list);
125 spin_unlock_bh(&serv->sv_cb_lock);
126 finish_wait(&serv->sv_cb_waitq, &wq);
127 dprintk("Invoking bc_svc_process()\n");
128 error = bc_svc_process(serv, req, rqstp);
129 dprintk("bc_svc_process() returned w/ error code= %d\n",
130 error);
131 } else {
132 spin_unlock_bh(&serv->sv_cb_lock);
133 if (!kthread_should_stop())
134 schedule();
135 finish_wait(&serv->sv_cb_waitq, &wq);
136 }
137 }
138
139 svc_exit_thread(rqstp);
140 return 0;
141}
142
143static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
144 struct svc_serv *serv)
145{
146 if (minorversion)
147 /*
148 * Save the svc_serv in the transport so that it can
149 * be referenced when the session backchannel is initialized
150 */
151 xprt->bc_serv = serv;
152}
153#else
154static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
155 struct svc_serv *serv)
156{
157}
158#endif /* CONFIG_NFS_V4_1 */
159
160static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
161 struct svc_serv *serv)
162{
163 int nrservs = nfs_callback_nr_threads;
164 int ret;
165
166 nfs_callback_bc_serv(minorversion, xprt, serv);
167
168 if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)
169 nrservs = NFS4_MIN_NR_CALLBACK_THREADS;
170
171 if (serv->sv_nrthreads == nrservs)
172 return 0;
173
174 ret = svc_set_num_threads(serv, NULL, nrservs);
175 if (ret) {
176 svc_set_num_threads(serv, NULL, 0);
177 return ret;
178 }
179 dprintk("nfs_callback_up: service started\n");
180 return 0;
181}
182
183static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
184{
185 struct nfs_net *nn = net_generic(net, nfs_net_id);
186
187 if (--nn->cb_users[minorversion])
188 return;
189
190 dprintk("NFS: destroy per-net callback data; net=%x\n", net->ns.inum);
191 svc_xprt_destroy_all(serv, net);
192}
193
194static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
195 struct net *net, struct rpc_xprt *xprt)
196{
197 struct nfs_net *nn = net_generic(net, nfs_net_id);
198 int ret;
199
200 if (nn->cb_users[minorversion]++)
201 return 0;
202
203 dprintk("NFS: create per-net callback data; net=%x\n", net->ns.inum);
204
205 ret = svc_bind(serv, net);
206 if (ret < 0) {
207 printk(KERN_WARNING "NFS: bind callback service failed\n");
208 goto err_bind;
209 }
210
211 ret = 0;
212 if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
213 ret = nfs4_callback_up_net(serv, net);
214 else if (xprt->ops->bc_setup)
215 set_bc_enabled(serv);
216 else
217 ret = -EPROTONOSUPPORT;
218
219 if (ret < 0) {
220 printk(KERN_ERR "NFS: callback service start failed\n");
221 goto err_socks;
222 }
223 return 0;
224
225err_socks:
226 svc_rpcb_cleanup(serv, net);
227err_bind:
228 nn->cb_users[minorversion]--;
229 dprintk("NFS: Couldn't create callback socket: err = %d; "
230 "net = %x\n", ret, net->ns.inum);
231 return ret;
232}
233
234static struct svc_serv *nfs_callback_create_svc(int minorversion)
235{
236 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
237 int (*threadfn)(void *data);
238 struct svc_serv *serv;
239
240 /*
241 * Check whether we're already up and running.
242 */
243 if (cb_info->serv)
244 return svc_get(cb_info->serv);
245
246 /*
247 * Sanity check: if there's no task,
248 * we should be the first user ...
249 */
250 if (cb_info->users)
251 printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
252 cb_info->users);
253
254 threadfn = nfs4_callback_svc;
255#if defined(CONFIG_NFS_V4_1)
256 if (minorversion)
257 threadfn = nfs41_callback_svc;
258#else
259 if (minorversion)
260 return ERR_PTR(-ENOTSUPP);
261#endif
262 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE,
263 threadfn);
264 if (!serv) {
265 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
266 return ERR_PTR(-ENOMEM);
267 }
268 cb_info->serv = serv;
269 /* As there is only one thread we need to over-ride the
270 * default maximum of 80 connections
271 */
272 serv->sv_maxconn = 1024;
273 dprintk("nfs_callback_create_svc: service created\n");
274 return serv;
275}
276
277/*
278 * Bring up the callback thread if it is not already up.
279 */
280int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
281{
282 struct svc_serv *serv;
283 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
284 int ret;
285 struct net *net = xprt->xprt_net;
286
287 mutex_lock(&nfs_callback_mutex);
288
289 serv = nfs_callback_create_svc(minorversion);
290 if (IS_ERR(serv)) {
291 ret = PTR_ERR(serv);
292 goto err_create;
293 }
294
295 ret = nfs_callback_up_net(minorversion, serv, net, xprt);
296 if (ret < 0)
297 goto err_net;
298
299 ret = nfs_callback_start_svc(minorversion, xprt, serv);
300 if (ret < 0)
301 goto err_start;
302
303 cb_info->users++;
304err_net:
305 if (!cb_info->users)
306 cb_info->serv = NULL;
307 svc_put(serv);
308err_create:
309 mutex_unlock(&nfs_callback_mutex);
310 return ret;
311
312err_start:
313 nfs_callback_down_net(minorversion, serv, net);
314 dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
315 goto err_net;
316}
317
318/*
319 * Kill the callback thread if it's no longer being used.
320 */
321void nfs_callback_down(int minorversion, struct net *net)
322{
323 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
324 struct svc_serv *serv;
325
326 mutex_lock(&nfs_callback_mutex);
327 serv = cb_info->serv;
328 nfs_callback_down_net(minorversion, serv, net);
329 cb_info->users--;
330 if (cb_info->users == 0) {
331 svc_get(serv);
332 svc_set_num_threads(serv, NULL, 0);
333 svc_put(serv);
334 dprintk("nfs_callback_down: service destroyed\n");
335 cb_info->serv = NULL;
336 }
337 mutex_unlock(&nfs_callback_mutex);
338}
339
340/* Boolean check of RPC_AUTH_GSS principal */
341int
342check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
343{
344 char *p = rqstp->rq_cred.cr_principal;
345
346 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
347 return 1;
348
349 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
350 if (clp->cl_minorversion != 0)
351 return 0;
352 /*
353 * It might just be a normal user principal, in which case
354 * userspace won't bother to tell us the name at all.
355 */
356 if (p == NULL)
357 return 0;
358
359 /*
360 * Did we get the acceptor from userland during the SETCLIENID
361 * negotiation?
362 */
363 if (clp->cl_acceptor)
364 return !strcmp(p, clp->cl_acceptor);
365
366 /*
367 * Otherwise try to verify it using the cl_hostname. Note that this
368 * doesn't work if a non-canonical hostname was used in the devname.
369 */
370
371 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
372
373 if (memcmp(p, "nfs@", 4) != 0)
374 return 0;
375 p += 4;
376 if (strcmp(p, clp->cl_hostname) != 0)
377 return 0;
378 return 1;
379}
380
381/*
382 * pg_authenticate method for nfsv4 callback threads.
383 *
384 * The authflavor has been negotiated, so an incorrect flavor is a server
385 * bug. Deny packets with incorrect authflavor.
386 *
387 * All other checking done after NFS decoding where the nfs_client can be
388 * found in nfs4_callback_compound
389 */
390static int nfs_callback_authenticate(struct svc_rqst *rqstp)
391{
392 rqstp->rq_auth_stat = rpc_autherr_badcred;
393
394 switch (rqstp->rq_authop->flavour) {
395 case RPC_AUTH_NULL:
396 if (rqstp->rq_proc != CB_NULL)
397 return SVC_DENIED;
398 break;
399 case RPC_AUTH_GSS:
400 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
401 if (svc_is_backchannel(rqstp))
402 return SVC_DENIED;
403 }
404
405 rqstp->rq_auth_stat = rpc_auth_ok;
406 return SVC_OK;
407}
408
409/*
410 * Define NFS4 callback program
411 */
412static const struct svc_version *nfs4_callback_version[] = {
413 [1] = &nfs4_callback_version1,
414 [4] = &nfs4_callback_version4,
415};
416
417static struct svc_stat nfs4_callback_stats;
418
419static struct svc_program nfs4_callback_program = {
420 .pg_prog = NFS4_CALLBACK, /* RPC service number */
421 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
422 .pg_vers = nfs4_callback_version, /* version table */
423 .pg_name = "NFSv4 callback", /* service name */
424 .pg_class = "nfs", /* authentication class */
425 .pg_stats = &nfs4_callback_stats,
426 .pg_authenticate = nfs_callback_authenticate,
427 .pg_init_request = svc_generic_init_request,
428 .pg_rpcbind_set = svc_generic_rpcbind_set,
429};