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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/kthread.h>
21#include <linux/sunrpc/svcauth_gss.h>
22#include <linux/sunrpc/bc_xprt.h>
23
24#include <net/inet_sock.h>
25
26#include "nfs4_fs.h"
27#include "callback.h"
28#include "internal.h"
29#include "netns.h"
30
31#define NFSDBG_FACILITY NFSDBG_CALLBACK
32
33struct nfs_callback_data {
34 unsigned int users;
35 struct svc_serv *serv;
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 %x)\n",
53 nn->nfs_callback_tcpport, PF_INET, net->ns.inum);
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 %x\n",
60 nn->nfs_callback_tcpport6, PF_INET6, net->ns.inum);
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_freezable_should_stop(NULL)) {
81
82 if (signal_pending(current))
83 flush_signals(current);
84 /*
85 * Listen for a request on the socket
86 */
87 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
88 if (err == -EAGAIN || err == -EINTR)
89 continue;
90 svc_process(rqstp);
91 }
92 svc_exit_thread(rqstp);
93 module_put_and_exit(0);
94 return 0;
95}
96
97#if defined(CONFIG_NFS_V4_1)
98/*
99 * The callback service for NFSv4.1 callbacks
100 */
101static int
102nfs41_callback_svc(void *vrqstp)
103{
104 struct svc_rqst *rqstp = vrqstp;
105 struct svc_serv *serv = rqstp->rq_server;
106 struct rpc_rqst *req;
107 int error;
108 DEFINE_WAIT(wq);
109
110 set_freezable();
111
112 while (!kthread_freezable_should_stop(NULL)) {
113
114 if (signal_pending(current))
115 flush_signals(current);
116
117 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
118 spin_lock_bh(&serv->sv_cb_lock);
119 if (!list_empty(&serv->sv_cb_list)) {
120 req = list_first_entry(&serv->sv_cb_list,
121 struct rpc_rqst, rq_bc_list);
122 list_del(&req->rq_bc_list);
123 spin_unlock_bh(&serv->sv_cb_lock);
124 finish_wait(&serv->sv_cb_waitq, &wq);
125 dprintk("Invoking bc_svc_process()\n");
126 error = bc_svc_process(serv, req, rqstp);
127 dprintk("bc_svc_process() returned w/ error code= %d\n",
128 error);
129 } else {
130 spin_unlock_bh(&serv->sv_cb_lock);
131 if (!kthread_should_stop())
132 schedule();
133 finish_wait(&serv->sv_cb_waitq, &wq);
134 }
135 }
136 svc_exit_thread(rqstp);
137 module_put_and_exit(0);
138 return 0;
139}
140
141static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
142 struct svc_serv *serv)
143{
144 if (minorversion)
145 /*
146 * Save the svc_serv in the transport so that it can
147 * be referenced when the session backchannel is initialized
148 */
149 xprt->bc_serv = serv;
150}
151#else
152static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
153 struct svc_serv *serv)
154{
155}
156#endif /* CONFIG_NFS_V4_1 */
157
158static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
159 struct svc_serv *serv)
160{
161 int nrservs = nfs_callback_nr_threads;
162 int ret;
163
164 nfs_callback_bc_serv(minorversion, xprt, serv);
165
166 if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)
167 nrservs = NFS4_MIN_NR_CALLBACK_THREADS;
168
169 if (serv->sv_nrthreads-1 == nrservs)
170 return 0;
171
172 ret = serv->sv_ops->svo_setup(serv, NULL, nrservs);
173 if (ret) {
174 serv->sv_ops->svo_setup(serv, NULL, 0);
175 return ret;
176 }
177 dprintk("nfs_callback_up: service started\n");
178 return 0;
179}
180
181static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
182{
183 struct nfs_net *nn = net_generic(net, nfs_net_id);
184
185 if (--nn->cb_users[minorversion])
186 return;
187
188 dprintk("NFS: destroy per-net callback data; net=%x\n", net->ns.inum);
189 svc_shutdown_net(serv, net);
190}
191
192static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
193 struct net *net, struct rpc_xprt *xprt)
194{
195 struct nfs_net *nn = net_generic(net, nfs_net_id);
196 int ret;
197
198 if (nn->cb_users[minorversion]++)
199 return 0;
200
201 dprintk("NFS: create per-net callback data; net=%x\n", net->ns.inum);
202
203 ret = svc_bind(serv, net);
204 if (ret < 0) {
205 printk(KERN_WARNING "NFS: bind callback service failed\n");
206 goto err_bind;
207 }
208
209 ret = -EPROTONOSUPPORT;
210 if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
211 ret = nfs4_callback_up_net(serv, net);
212 else if (xprt->ops->bc_up)
213 ret = xprt->ops->bc_up(serv, net);
214
215 if (ret < 0) {
216 printk(KERN_ERR "NFS: callback service start failed\n");
217 goto err_socks;
218 }
219 return 0;
220
221err_socks:
222 svc_rpcb_cleanup(serv, net);
223err_bind:
224 nn->cb_users[minorversion]--;
225 dprintk("NFS: Couldn't create callback socket: err = %d; "
226 "net = %x\n", ret, net->ns.inum);
227 return ret;
228}
229
230static const struct svc_serv_ops nfs40_cb_sv_ops = {
231 .svo_function = nfs4_callback_svc,
232 .svo_enqueue_xprt = svc_xprt_do_enqueue,
233 .svo_setup = svc_set_num_threads_sync,
234 .svo_module = THIS_MODULE,
235};
236#if defined(CONFIG_NFS_V4_1)
237static const struct svc_serv_ops nfs41_cb_sv_ops = {
238 .svo_function = nfs41_callback_svc,
239 .svo_enqueue_xprt = svc_xprt_do_enqueue,
240 .svo_setup = svc_set_num_threads_sync,
241 .svo_module = THIS_MODULE,
242};
243
244static const struct svc_serv_ops *nfs4_cb_sv_ops[] = {
245 [0] = &nfs40_cb_sv_ops,
246 [1] = &nfs41_cb_sv_ops,
247};
248#else
249static const struct svc_serv_ops *nfs4_cb_sv_ops[] = {
250 [0] = &nfs40_cb_sv_ops,
251 [1] = NULL,
252};
253#endif
254
255static struct svc_serv *nfs_callback_create_svc(int minorversion)
256{
257 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
258 const struct svc_serv_ops *sv_ops;
259 struct svc_serv *serv;
260
261 /*
262 * Check whether we're already up and running.
263 */
264 if (cb_info->serv) {
265 /*
266 * Note: increase service usage, because later in case of error
267 * svc_destroy() will be called.
268 */
269 svc_get(cb_info->serv);
270 return cb_info->serv;
271 }
272
273 switch (minorversion) {
274 case 0:
275 sv_ops = nfs4_cb_sv_ops[0];
276 break;
277 default:
278 sv_ops = nfs4_cb_sv_ops[1];
279 }
280
281 if (sv_ops == NULL)
282 return ERR_PTR(-ENOTSUPP);
283
284 /*
285 * Sanity check: if there's no task,
286 * we should be the first user ...
287 */
288 if (cb_info->users)
289 printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
290 cb_info->users);
291
292 serv = svc_create_pooled(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops);
293 if (!serv) {
294 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
295 return ERR_PTR(-ENOMEM);
296 }
297 cb_info->serv = serv;
298 /* As there is only one thread we need to over-ride the
299 * default maximum of 80 connections
300 */
301 serv->sv_maxconn = 1024;
302 dprintk("nfs_callback_create_svc: service created\n");
303 return serv;
304}
305
306/*
307 * Bring up the callback thread if it is not already up.
308 */
309int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
310{
311 struct svc_serv *serv;
312 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
313 int ret;
314 struct net *net = xprt->xprt_net;
315
316 mutex_lock(&nfs_callback_mutex);
317
318 serv = nfs_callback_create_svc(minorversion);
319 if (IS_ERR(serv)) {
320 ret = PTR_ERR(serv);
321 goto err_create;
322 }
323
324 ret = nfs_callback_up_net(minorversion, serv, net, xprt);
325 if (ret < 0)
326 goto err_net;
327
328 ret = nfs_callback_start_svc(minorversion, xprt, serv);
329 if (ret < 0)
330 goto err_start;
331
332 cb_info->users++;
333 /*
334 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
335 * svc_prepare_thread increments that. So we need to call svc_destroy
336 * on both success and failure so that the refcount is 1 when the
337 * thread exits.
338 */
339err_net:
340 if (!cb_info->users)
341 cb_info->serv = NULL;
342 svc_destroy(serv);
343err_create:
344 mutex_unlock(&nfs_callback_mutex);
345 return ret;
346
347err_start:
348 nfs_callback_down_net(minorversion, serv, net);
349 dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
350 goto err_net;
351}
352
353/*
354 * Kill the callback thread if it's no longer being used.
355 */
356void nfs_callback_down(int minorversion, struct net *net)
357{
358 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
359 struct svc_serv *serv;
360
361 mutex_lock(&nfs_callback_mutex);
362 serv = cb_info->serv;
363 nfs_callback_down_net(minorversion, serv, net);
364 cb_info->users--;
365 if (cb_info->users == 0) {
366 svc_get(serv);
367 serv->sv_ops->svo_setup(serv, NULL, 0);
368 svc_destroy(serv);
369 dprintk("nfs_callback_down: service destroyed\n");
370 cb_info->serv = NULL;
371 }
372 mutex_unlock(&nfs_callback_mutex);
373}
374
375/* Boolean check of RPC_AUTH_GSS principal */
376int
377check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
378{
379 char *p = rqstp->rq_cred.cr_principal;
380
381 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
382 return 1;
383
384 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
385 if (clp->cl_minorversion != 0)
386 return 0;
387 /*
388 * It might just be a normal user principal, in which case
389 * userspace won't bother to tell us the name at all.
390 */
391 if (p == NULL)
392 return 0;
393
394 /*
395 * Did we get the acceptor from userland during the SETCLIENID
396 * negotiation?
397 */
398 if (clp->cl_acceptor)
399 return !strcmp(p, clp->cl_acceptor);
400
401 /*
402 * Otherwise try to verify it using the cl_hostname. Note that this
403 * doesn't work if a non-canonical hostname was used in the devname.
404 */
405
406 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
407
408 if (memcmp(p, "nfs@", 4) != 0)
409 return 0;
410 p += 4;
411 if (strcmp(p, clp->cl_hostname) != 0)
412 return 0;
413 return 1;
414}
415
416/*
417 * pg_authenticate method for nfsv4 callback threads.
418 *
419 * The authflavor has been negotiated, so an incorrect flavor is a server
420 * bug. Deny packets with incorrect authflavor.
421 *
422 * All other checking done after NFS decoding where the nfs_client can be
423 * found in nfs4_callback_compound
424 */
425static int nfs_callback_authenticate(struct svc_rqst *rqstp)
426{
427 switch (rqstp->rq_authop->flavour) {
428 case RPC_AUTH_NULL:
429 if (rqstp->rq_proc != CB_NULL)
430 return SVC_DENIED;
431 break;
432 case RPC_AUTH_GSS:
433 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
434 if (svc_is_backchannel(rqstp))
435 return SVC_DENIED;
436 }
437 return SVC_OK;
438}
439
440/*
441 * Define NFS4 callback program
442 */
443static const struct svc_version *nfs4_callback_version[] = {
444 [1] = &nfs4_callback_version1,
445 [4] = &nfs4_callback_version4,
446};
447
448static struct svc_stat nfs4_callback_stats;
449
450static struct svc_program nfs4_callback_program = {
451 .pg_prog = NFS4_CALLBACK, /* RPC service number */
452 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
453 .pg_vers = nfs4_callback_version, /* version table */
454 .pg_name = "NFSv4 callback", /* service name */
455 .pg_class = "nfs", /* authentication class */
456 .pg_stats = &nfs4_callback_stats,
457 .pg_authenticate = nfs_callback_authenticate,
458};
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};
35
36static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
37static DEFINE_MUTEX(nfs_callback_mutex);
38static struct svc_program nfs4_callback_program;
39
40static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
41{
42 int ret;
43 struct nfs_net *nn = net_generic(net, nfs_net_id);
44
45 ret = svc_create_xprt(serv, "tcp", net, PF_INET,
46 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
47 if (ret <= 0)
48 goto out_err;
49 nn->nfs_callback_tcpport = ret;
50 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
51 nn->nfs_callback_tcpport, PF_INET, net);
52
53 ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
54 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
55 if (ret > 0) {
56 nn->nfs_callback_tcpport6 = ret;
57 dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
58 nn->nfs_callback_tcpport6, PF_INET6, net);
59 } else if (ret != -EAFNOSUPPORT)
60 goto out_err;
61 return 0;
62
63out_err:
64 return (ret) ? ret : -ENOMEM;
65}
66
67/*
68 * This is the NFSv4 callback kernel thread.
69 */
70static int
71nfs4_callback_svc(void *vrqstp)
72{
73 int err;
74 struct svc_rqst *rqstp = vrqstp;
75
76 set_freezable();
77
78 while (!kthread_should_stop()) {
79 /*
80 * Listen for a request on the socket
81 */
82 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
83 if (err == -EAGAIN || err == -EINTR)
84 continue;
85 svc_process(rqstp);
86 }
87 return 0;
88}
89
90#if defined(CONFIG_NFS_V4_1)
91/*
92 * The callback service for NFSv4.1 callbacks
93 */
94static int
95nfs41_callback_svc(void *vrqstp)
96{
97 struct svc_rqst *rqstp = vrqstp;
98 struct svc_serv *serv = rqstp->rq_server;
99 struct rpc_rqst *req;
100 int error;
101 DEFINE_WAIT(wq);
102
103 set_freezable();
104
105 while (!kthread_should_stop()) {
106 if (try_to_freeze())
107 continue;
108
109 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
110 spin_lock_bh(&serv->sv_cb_lock);
111 if (!list_empty(&serv->sv_cb_list)) {
112 req = list_first_entry(&serv->sv_cb_list,
113 struct rpc_rqst, rq_bc_list);
114 list_del(&req->rq_bc_list);
115 spin_unlock_bh(&serv->sv_cb_lock);
116 finish_wait(&serv->sv_cb_waitq, &wq);
117 dprintk("Invoking bc_svc_process()\n");
118 error = bc_svc_process(serv, req, rqstp);
119 dprintk("bc_svc_process() returned w/ error code= %d\n",
120 error);
121 } else {
122 spin_unlock_bh(&serv->sv_cb_lock);
123 schedule();
124 finish_wait(&serv->sv_cb_waitq, &wq);
125 }
126 flush_signals(current);
127 }
128 return 0;
129}
130
131static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
132 struct svc_serv *serv)
133{
134 if (minorversion)
135 /*
136 * Save the svc_serv in the transport so that it can
137 * be referenced when the session backchannel is initialized
138 */
139 xprt->bc_serv = serv;
140}
141#else
142static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
143 struct svc_serv *serv)
144{
145}
146#endif /* CONFIG_NFS_V4_1 */
147
148static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
149 struct svc_serv *serv)
150{
151 int nrservs = nfs_callback_nr_threads;
152 int ret;
153
154 nfs_callback_bc_serv(minorversion, xprt, serv);
155
156 if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)
157 nrservs = NFS4_MIN_NR_CALLBACK_THREADS;
158
159 if (serv->sv_nrthreads-1 == nrservs)
160 return 0;
161
162 ret = serv->sv_ops->svo_setup(serv, NULL, nrservs);
163 if (ret) {
164 serv->sv_ops->svo_setup(serv, NULL, 0);
165 return ret;
166 }
167 dprintk("nfs_callback_up: service started\n");
168 return 0;
169}
170
171static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
172{
173 struct nfs_net *nn = net_generic(net, nfs_net_id);
174
175 if (--nn->cb_users[minorversion])
176 return;
177
178 dprintk("NFS: destroy per-net callback data; net=%p\n", net);
179 svc_shutdown_net(serv, net);
180}
181
182static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
183 struct net *net, struct rpc_xprt *xprt)
184{
185 struct nfs_net *nn = net_generic(net, nfs_net_id);
186 int ret;
187
188 if (nn->cb_users[minorversion]++)
189 return 0;
190
191 dprintk("NFS: create per-net callback data; net=%p\n", net);
192
193 ret = svc_bind(serv, net);
194 if (ret < 0) {
195 printk(KERN_WARNING "NFS: bind callback service failed\n");
196 goto err_bind;
197 }
198
199 ret = -EPROTONOSUPPORT;
200 if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
201 ret = nfs4_callback_up_net(serv, net);
202 else if (xprt->ops->bc_up)
203 ret = xprt->ops->bc_up(serv, net);
204
205 if (ret < 0) {
206 printk(KERN_ERR "NFS: callback service start failed\n");
207 goto err_socks;
208 }
209 return 0;
210
211err_socks:
212 svc_rpcb_cleanup(serv, net);
213err_bind:
214 nn->cb_users[minorversion]--;
215 dprintk("NFS: Couldn't create callback socket: err = %d; "
216 "net = %p\n", ret, net);
217 return ret;
218}
219
220static struct svc_serv_ops nfs40_cb_sv_ops = {
221 .svo_function = nfs4_callback_svc,
222 .svo_enqueue_xprt = svc_xprt_do_enqueue,
223 .svo_setup = svc_set_num_threads,
224 .svo_module = THIS_MODULE,
225};
226#if defined(CONFIG_NFS_V4_1)
227static struct svc_serv_ops nfs41_cb_sv_ops = {
228 .svo_function = nfs41_callback_svc,
229 .svo_enqueue_xprt = svc_xprt_do_enqueue,
230 .svo_setup = svc_set_num_threads,
231 .svo_module = THIS_MODULE,
232};
233
234struct svc_serv_ops *nfs4_cb_sv_ops[] = {
235 [0] = &nfs40_cb_sv_ops,
236 [1] = &nfs41_cb_sv_ops,
237};
238#else
239struct svc_serv_ops *nfs4_cb_sv_ops[] = {
240 [0] = &nfs40_cb_sv_ops,
241 [1] = NULL,
242};
243#endif
244
245static struct svc_serv *nfs_callback_create_svc(int minorversion)
246{
247 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
248 struct svc_serv *serv;
249 struct svc_serv_ops *sv_ops;
250
251 /*
252 * Check whether we're already up and running.
253 */
254 if (cb_info->serv) {
255 /*
256 * Note: increase service usage, because later in case of error
257 * svc_destroy() will be called.
258 */
259 svc_get(cb_info->serv);
260 return cb_info->serv;
261 }
262
263 switch (minorversion) {
264 case 0:
265 sv_ops = nfs4_cb_sv_ops[0];
266 break;
267 default:
268 sv_ops = nfs4_cb_sv_ops[1];
269 }
270
271 if (sv_ops == NULL)
272 return ERR_PTR(-ENOTSUPP);
273
274 /*
275 * Sanity check: if there's no task,
276 * we should be the first user ...
277 */
278 if (cb_info->users)
279 printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
280 cb_info->users);
281
282 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops);
283 if (!serv) {
284 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
285 return ERR_PTR(-ENOMEM);
286 }
287 cb_info->serv = serv;
288 /* As there is only one thread we need to over-ride the
289 * default maximum of 80 connections
290 */
291 serv->sv_maxconn = 1024;
292 dprintk("nfs_callback_create_svc: service created\n");
293 return serv;
294}
295
296/*
297 * Bring up the callback thread if it is not already up.
298 */
299int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
300{
301 struct svc_serv *serv;
302 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
303 int ret;
304 struct net *net = xprt->xprt_net;
305
306 mutex_lock(&nfs_callback_mutex);
307
308 serv = nfs_callback_create_svc(minorversion);
309 if (IS_ERR(serv)) {
310 ret = PTR_ERR(serv);
311 goto err_create;
312 }
313
314 ret = nfs_callback_up_net(minorversion, serv, net, xprt);
315 if (ret < 0)
316 goto err_net;
317
318 ret = nfs_callback_start_svc(minorversion, xprt, serv);
319 if (ret < 0)
320 goto err_start;
321
322 cb_info->users++;
323 /*
324 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
325 * svc_prepare_thread increments that. So we need to call svc_destroy
326 * on both success and failure so that the refcount is 1 when the
327 * thread exits.
328 */
329err_net:
330 if (!cb_info->users)
331 cb_info->serv = NULL;
332 svc_destroy(serv);
333err_create:
334 mutex_unlock(&nfs_callback_mutex);
335 return ret;
336
337err_start:
338 nfs_callback_down_net(minorversion, serv, net);
339 dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
340 goto err_net;
341}
342
343/*
344 * Kill the callback thread if it's no longer being used.
345 */
346void nfs_callback_down(int minorversion, struct net *net)
347{
348 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
349 struct svc_serv *serv;
350
351 mutex_lock(&nfs_callback_mutex);
352 serv = cb_info->serv;
353 nfs_callback_down_net(minorversion, serv, net);
354 cb_info->users--;
355 if (cb_info->users == 0) {
356 svc_get(serv);
357 serv->sv_ops->svo_setup(serv, NULL, 0);
358 svc_destroy(serv);
359 dprintk("nfs_callback_down: service destroyed\n");
360 cb_info->serv = NULL;
361 }
362 mutex_unlock(&nfs_callback_mutex);
363}
364
365/* Boolean check of RPC_AUTH_GSS principal */
366int
367check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
368{
369 char *p = rqstp->rq_cred.cr_principal;
370
371 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
372 return 1;
373
374 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
375 if (clp->cl_minorversion != 0)
376 return 0;
377 /*
378 * It might just be a normal user principal, in which case
379 * userspace won't bother to tell us the name at all.
380 */
381 if (p == NULL)
382 return 0;
383
384 /*
385 * Did we get the acceptor from userland during the SETCLIENID
386 * negotiation?
387 */
388 if (clp->cl_acceptor)
389 return !strcmp(p, clp->cl_acceptor);
390
391 /*
392 * Otherwise try to verify it using the cl_hostname. Note that this
393 * doesn't work if a non-canonical hostname was used in the devname.
394 */
395
396 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
397
398 if (memcmp(p, "nfs@", 4) != 0)
399 return 0;
400 p += 4;
401 if (strcmp(p, clp->cl_hostname) != 0)
402 return 0;
403 return 1;
404}
405
406/*
407 * pg_authenticate method for nfsv4 callback threads.
408 *
409 * The authflavor has been negotiated, so an incorrect flavor is a server
410 * bug. Deny packets with incorrect authflavor.
411 *
412 * All other checking done after NFS decoding where the nfs_client can be
413 * found in nfs4_callback_compound
414 */
415static int nfs_callback_authenticate(struct svc_rqst *rqstp)
416{
417 switch (rqstp->rq_authop->flavour) {
418 case RPC_AUTH_NULL:
419 if (rqstp->rq_proc != CB_NULL)
420 return SVC_DENIED;
421 break;
422 case RPC_AUTH_GSS:
423 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
424 if (svc_is_backchannel(rqstp))
425 return SVC_DENIED;
426 }
427 return SVC_OK;
428}
429
430/*
431 * Define NFS4 callback program
432 */
433static struct svc_version *nfs4_callback_version[] = {
434 [1] = &nfs4_callback_version1,
435 [4] = &nfs4_callback_version4,
436};
437
438static struct svc_stat nfs4_callback_stats;
439
440static struct svc_program nfs4_callback_program = {
441 .pg_prog = NFS4_CALLBACK, /* RPC service number */
442 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
443 .pg_vers = nfs4_callback_version, /* version table */
444 .pg_name = "NFSv4 callback", /* service name */
445 .pg_class = "nfs", /* authentication class */
446 .pg_stats = &nfs4_callback_stats,
447 .pg_authenticate = nfs_callback_authenticate,
448};