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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// 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 const struct cred *cred = current_cred();
45 int ret;
46 struct nfs_net *nn = net_generic(net, nfs_net_id);
47
48 ret = svc_create_xprt(serv, "tcp", net, PF_INET,
49 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS,
50 cred);
51 if (ret <= 0)
52 goto out_err;
53 nn->nfs_callback_tcpport = ret;
54 dprintk("NFS: Callback listener port = %u (af %u, net %x)\n",
55 nn->nfs_callback_tcpport, PF_INET, net->ns.inum);
56
57 ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
58 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS,
59 cred);
60 if (ret > 0) {
61 nn->nfs_callback_tcpport6 = ret;
62 dprintk("NFS: Callback listener port = %u (af %u, net %x)\n",
63 nn->nfs_callback_tcpport6, PF_INET6, net->ns.inum);
64 } else if (ret != -EAFNOSUPPORT)
65 goto out_err;
66 return 0;
67
68out_err:
69 return (ret) ? ret : -ENOMEM;
70}
71
72/*
73 * This is the NFSv4 callback kernel thread.
74 */
75static int
76nfs4_callback_svc(void *vrqstp)
77{
78 int err;
79 struct svc_rqst *rqstp = vrqstp;
80
81 set_freezable();
82
83 while (!kthread_freezable_should_stop(NULL)) {
84
85 if (signal_pending(current))
86 flush_signals(current);
87 /*
88 * Listen for a request on the socket
89 */
90 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
91 if (err == -EAGAIN || err == -EINTR)
92 continue;
93 svc_process(rqstp);
94 }
95 svc_exit_thread(rqstp);
96 module_put_and_exit(0);
97 return 0;
98}
99
100#if defined(CONFIG_NFS_V4_1)
101/*
102 * The callback service for NFSv4.1 callbacks
103 */
104static int
105nfs41_callback_svc(void *vrqstp)
106{
107 struct svc_rqst *rqstp = vrqstp;
108 struct svc_serv *serv = rqstp->rq_server;
109 struct rpc_rqst *req;
110 int error;
111 DEFINE_WAIT(wq);
112
113 set_freezable();
114
115 while (!kthread_freezable_should_stop(NULL)) {
116
117 if (signal_pending(current))
118 flush_signals(current);
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 if (!kthread_should_stop())
135 schedule();
136 finish_wait(&serv->sv_cb_waitq, &wq);
137 }
138 }
139 svc_exit_thread(rqstp);
140 module_put_and_exit(0);
141 return 0;
142}
143
144static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
145 struct svc_serv *serv)
146{
147 if (minorversion)
148 /*
149 * Save the svc_serv in the transport so that it can
150 * be referenced when the session backchannel is initialized
151 */
152 xprt->bc_serv = serv;
153}
154#else
155static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
156 struct svc_serv *serv)
157{
158}
159#endif /* CONFIG_NFS_V4_1 */
160
161static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
162 struct svc_serv *serv)
163{
164 int nrservs = nfs_callback_nr_threads;
165 int ret;
166
167 nfs_callback_bc_serv(minorversion, xprt, serv);
168
169 if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)
170 nrservs = NFS4_MIN_NR_CALLBACK_THREADS;
171
172 if (serv->sv_nrthreads-1 == nrservs)
173 return 0;
174
175 ret = serv->sv_ops->svo_setup(serv, NULL, nrservs);
176 if (ret) {
177 serv->sv_ops->svo_setup(serv, NULL, 0);
178 return ret;
179 }
180 dprintk("nfs_callback_up: service started\n");
181 return 0;
182}
183
184static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
185{
186 struct nfs_net *nn = net_generic(net, nfs_net_id);
187
188 if (--nn->cb_users[minorversion])
189 return;
190
191 dprintk("NFS: destroy per-net callback data; net=%x\n", net->ns.inum);
192 svc_shutdown_net(serv, net);
193}
194
195static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
196 struct net *net, struct rpc_xprt *xprt)
197{
198 struct nfs_net *nn = net_generic(net, nfs_net_id);
199 int ret;
200
201 if (nn->cb_users[minorversion]++)
202 return 0;
203
204 dprintk("NFS: create per-net callback data; net=%x\n", net->ns.inum);
205
206 ret = svc_bind(serv, net);
207 if (ret < 0) {
208 printk(KERN_WARNING "NFS: bind callback service failed\n");
209 goto err_bind;
210 }
211
212 ret = 0;
213 if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
214 ret = nfs4_callback_up_net(serv, net);
215 else if (xprt->ops->bc_setup)
216 set_bc_enabled(serv);
217 else
218 ret = -EPROTONOSUPPORT;
219
220 if (ret < 0) {
221 printk(KERN_ERR "NFS: callback service start failed\n");
222 goto err_socks;
223 }
224 return 0;
225
226err_socks:
227 svc_rpcb_cleanup(serv, net);
228err_bind:
229 nn->cb_users[minorversion]--;
230 dprintk("NFS: Couldn't create callback socket: err = %d; "
231 "net = %x\n", ret, net->ns.inum);
232 return ret;
233}
234
235static const struct svc_serv_ops nfs40_cb_sv_ops = {
236 .svo_function = nfs4_callback_svc,
237 .svo_enqueue_xprt = svc_xprt_do_enqueue,
238 .svo_setup = svc_set_num_threads_sync,
239 .svo_module = THIS_MODULE,
240};
241#if defined(CONFIG_NFS_V4_1)
242static const struct svc_serv_ops nfs41_cb_sv_ops = {
243 .svo_function = nfs41_callback_svc,
244 .svo_enqueue_xprt = svc_xprt_do_enqueue,
245 .svo_setup = svc_set_num_threads_sync,
246 .svo_module = THIS_MODULE,
247};
248
249static const struct svc_serv_ops *nfs4_cb_sv_ops[] = {
250 [0] = &nfs40_cb_sv_ops,
251 [1] = &nfs41_cb_sv_ops,
252};
253#else
254static const struct svc_serv_ops *nfs4_cb_sv_ops[] = {
255 [0] = &nfs40_cb_sv_ops,
256 [1] = NULL,
257};
258#endif
259
260static struct svc_serv *nfs_callback_create_svc(int minorversion)
261{
262 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
263 const struct svc_serv_ops *sv_ops;
264 struct svc_serv *serv;
265
266 /*
267 * Check whether we're already up and running.
268 */
269 if (cb_info->serv) {
270 /*
271 * Note: increase service usage, because later in case of error
272 * svc_destroy() will be called.
273 */
274 svc_get(cb_info->serv);
275 return cb_info->serv;
276 }
277
278 switch (minorversion) {
279 case 0:
280 sv_ops = nfs4_cb_sv_ops[0];
281 break;
282 default:
283 sv_ops = nfs4_cb_sv_ops[1];
284 }
285
286 if (sv_ops == NULL)
287 return ERR_PTR(-ENOTSUPP);
288
289 /*
290 * Sanity check: if there's no task,
291 * we should be the first user ...
292 */
293 if (cb_info->users)
294 printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
295 cb_info->users);
296
297 serv = svc_create_pooled(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops);
298 if (!serv) {
299 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
300 return ERR_PTR(-ENOMEM);
301 }
302 cb_info->serv = serv;
303 /* As there is only one thread we need to over-ride the
304 * default maximum of 80 connections
305 */
306 serv->sv_maxconn = 1024;
307 dprintk("nfs_callback_create_svc: service created\n");
308 return serv;
309}
310
311/*
312 * Bring up the callback thread if it is not already up.
313 */
314int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
315{
316 struct svc_serv *serv;
317 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
318 int ret;
319 struct net *net = xprt->xprt_net;
320
321 mutex_lock(&nfs_callback_mutex);
322
323 serv = nfs_callback_create_svc(minorversion);
324 if (IS_ERR(serv)) {
325 ret = PTR_ERR(serv);
326 goto err_create;
327 }
328
329 ret = nfs_callback_up_net(minorversion, serv, net, xprt);
330 if (ret < 0)
331 goto err_net;
332
333 ret = nfs_callback_start_svc(minorversion, xprt, serv);
334 if (ret < 0)
335 goto err_start;
336
337 cb_info->users++;
338 /*
339 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
340 * svc_prepare_thread increments that. So we need to call svc_destroy
341 * on both success and failure so that the refcount is 1 when the
342 * thread exits.
343 */
344err_net:
345 if (!cb_info->users)
346 cb_info->serv = NULL;
347 svc_destroy(serv);
348err_create:
349 mutex_unlock(&nfs_callback_mutex);
350 return ret;
351
352err_start:
353 nfs_callback_down_net(minorversion, serv, net);
354 dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
355 goto err_net;
356}
357
358/*
359 * Kill the callback thread if it's no longer being used.
360 */
361void nfs_callback_down(int minorversion, struct net *net)
362{
363 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
364 struct svc_serv *serv;
365
366 mutex_lock(&nfs_callback_mutex);
367 serv = cb_info->serv;
368 nfs_callback_down_net(minorversion, serv, net);
369 cb_info->users--;
370 if (cb_info->users == 0) {
371 svc_get(serv);
372 serv->sv_ops->svo_setup(serv, NULL, 0);
373 svc_destroy(serv);
374 dprintk("nfs_callback_down: service destroyed\n");
375 cb_info->serv = NULL;
376 }
377 mutex_unlock(&nfs_callback_mutex);
378}
379
380/* Boolean check of RPC_AUTH_GSS principal */
381int
382check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
383{
384 char *p = rqstp->rq_cred.cr_principal;
385
386 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
387 return 1;
388
389 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
390 if (clp->cl_minorversion != 0)
391 return 0;
392 /*
393 * It might just be a normal user principal, in which case
394 * userspace won't bother to tell us the name at all.
395 */
396 if (p == NULL)
397 return 0;
398
399 /*
400 * Did we get the acceptor from userland during the SETCLIENID
401 * negotiation?
402 */
403 if (clp->cl_acceptor)
404 return !strcmp(p, clp->cl_acceptor);
405
406 /*
407 * Otherwise try to verify it using the cl_hostname. Note that this
408 * doesn't work if a non-canonical hostname was used in the devname.
409 */
410
411 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
412
413 if (memcmp(p, "nfs@", 4) != 0)
414 return 0;
415 p += 4;
416 if (strcmp(p, clp->cl_hostname) != 0)
417 return 0;
418 return 1;
419}
420
421/*
422 * pg_authenticate method for nfsv4 callback threads.
423 *
424 * The authflavor has been negotiated, so an incorrect flavor is a server
425 * bug. Deny packets with incorrect authflavor.
426 *
427 * All other checking done after NFS decoding where the nfs_client can be
428 * found in nfs4_callback_compound
429 */
430static int nfs_callback_authenticate(struct svc_rqst *rqstp)
431{
432 switch (rqstp->rq_authop->flavour) {
433 case RPC_AUTH_NULL:
434 if (rqstp->rq_proc != CB_NULL)
435 return SVC_DENIED;
436 break;
437 case RPC_AUTH_GSS:
438 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
439 if (svc_is_backchannel(rqstp))
440 return SVC_DENIED;
441 }
442 return SVC_OK;
443}
444
445/*
446 * Define NFS4 callback program
447 */
448static const struct svc_version *nfs4_callback_version[] = {
449 [1] = &nfs4_callback_version1,
450 [4] = &nfs4_callback_version4,
451};
452
453static struct svc_stat nfs4_callback_stats;
454
455static struct svc_program nfs4_callback_program = {
456 .pg_prog = NFS4_CALLBACK, /* RPC service number */
457 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
458 .pg_vers = nfs4_callback_version, /* version table */
459 .pg_name = "NFSv4 callback", /* service name */
460 .pg_class = "nfs", /* authentication class */
461 .pg_stats = &nfs4_callback_stats,
462 .pg_authenticate = nfs_callback_authenticate,
463 .pg_init_request = svc_generic_init_request,
464 .pg_rpcbind_set = svc_generic_rpcbind_set,
465};