Loading...
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};
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};