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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/mutex.h>
16#include <linux/freezer.h>
17#include <linux/kthread.h>
18#include <linux/sunrpc/svcauth_gss.h>
19#include <linux/sunrpc/bc_xprt.h>
20
21#include <net/inet_sock.h>
22
23#include "nfs4_fs.h"
24#include "callback.h"
25#include "internal.h"
26
27#define NFSDBG_FACILITY NFSDBG_CALLBACK
28
29struct nfs_callback_data {
30 unsigned int users;
31 struct svc_serv *serv;
32 struct svc_rqst *rqst;
33 struct task_struct *task;
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
40unsigned int nfs_callback_set_tcpport;
41unsigned short nfs_callback_tcpport;
42unsigned short nfs_callback_tcpport6;
43#define NFS_CALLBACK_MAXPORTNR (65535U)
44
45static int param_set_portnr(const char *val, const struct kernel_param *kp)
46{
47 unsigned long num;
48 int ret;
49
50 if (!val)
51 return -EINVAL;
52 ret = strict_strtoul(val, 0, &num);
53 if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
54 return -EINVAL;
55 *((unsigned int *)kp->arg) = num;
56 return 0;
57}
58static struct kernel_param_ops param_ops_portnr = {
59 .set = param_set_portnr,
60 .get = param_get_uint,
61};
62#define param_check_portnr(name, p) __param_check(name, p, unsigned int);
63
64module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
65
66/*
67 * This is the NFSv4 callback kernel thread.
68 */
69static int
70nfs4_callback_svc(void *vrqstp)
71{
72 int err, preverr = 0;
73 struct svc_rqst *rqstp = vrqstp;
74
75 set_freezable();
76
77 while (!kthread_should_stop()) {
78 /*
79 * Listen for a request on the socket
80 */
81 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
82 if (err == -EAGAIN || err == -EINTR) {
83 preverr = err;
84 continue;
85 }
86 if (err < 0) {
87 if (err != preverr) {
88 printk(KERN_WARNING "%s: unexpected error "
89 "from svc_recv (%d)\n", __func__, err);
90 preverr = err;
91 }
92 schedule_timeout_uninterruptible(HZ);
93 continue;
94 }
95 preverr = err;
96 svc_process(rqstp);
97 }
98 return 0;
99}
100
101/*
102 * Prepare to bring up the NFSv4 callback service
103 */
104struct svc_rqst *
105nfs4_callback_up(struct svc_serv *serv)
106{
107 int ret;
108
109 ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET,
110 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
111 if (ret <= 0)
112 goto out_err;
113 nfs_callback_tcpport = ret;
114 dprintk("NFS: Callback listener port = %u (af %u)\n",
115 nfs_callback_tcpport, PF_INET);
116
117 ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET6,
118 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
119 if (ret > 0) {
120 nfs_callback_tcpport6 = ret;
121 dprintk("NFS: Callback listener port = %u (af %u)\n",
122 nfs_callback_tcpport6, PF_INET6);
123 } else if (ret == -EAFNOSUPPORT)
124 ret = 0;
125 else
126 goto out_err;
127
128 return svc_prepare_thread(serv, &serv->sv_pools[0]);
129
130out_err:
131 if (ret == 0)
132 ret = -ENOMEM;
133 return ERR_PTR(ret);
134}
135
136#if defined(CONFIG_NFS_V4_1)
137/*
138 * The callback service for NFSv4.1 callbacks
139 */
140static int
141nfs41_callback_svc(void *vrqstp)
142{
143 struct svc_rqst *rqstp = vrqstp;
144 struct svc_serv *serv = rqstp->rq_server;
145 struct rpc_rqst *req;
146 int error;
147 DEFINE_WAIT(wq);
148
149 set_freezable();
150
151 while (!kthread_should_stop()) {
152 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
153 spin_lock_bh(&serv->sv_cb_lock);
154 if (!list_empty(&serv->sv_cb_list)) {
155 req = list_first_entry(&serv->sv_cb_list,
156 struct rpc_rqst, rq_bc_list);
157 list_del(&req->rq_bc_list);
158 spin_unlock_bh(&serv->sv_cb_lock);
159 dprintk("Invoking bc_svc_process()\n");
160 error = bc_svc_process(serv, req, rqstp);
161 dprintk("bc_svc_process() returned w/ error code= %d\n",
162 error);
163 } else {
164 spin_unlock_bh(&serv->sv_cb_lock);
165 schedule();
166 }
167 finish_wait(&serv->sv_cb_waitq, &wq);
168 }
169 return 0;
170}
171
172/*
173 * Bring up the NFSv4.1 callback service
174 */
175struct svc_rqst *
176nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
177{
178 struct svc_rqst *rqstp;
179 int ret;
180
181 /*
182 * Create an svc_sock for the back channel service that shares the
183 * fore channel connection.
184 * Returns the input port (0) and sets the svc_serv bc_xprt on success
185 */
186 ret = svc_create_xprt(serv, "tcp-bc", &init_net, PF_INET, 0,
187 SVC_SOCK_ANONYMOUS);
188 if (ret < 0) {
189 rqstp = ERR_PTR(ret);
190 goto out;
191 }
192
193 /*
194 * Save the svc_serv in the transport so that it can
195 * be referenced when the session backchannel is initialized
196 */
197 xprt->bc_serv = serv;
198
199 INIT_LIST_HEAD(&serv->sv_cb_list);
200 spin_lock_init(&serv->sv_cb_lock);
201 init_waitqueue_head(&serv->sv_cb_waitq);
202 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
203 if (IS_ERR(rqstp)) {
204 svc_xprt_put(serv->sv_bc_xprt);
205 serv->sv_bc_xprt = NULL;
206 }
207out:
208 dprintk("--> %s return %ld\n", __func__,
209 IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
210 return rqstp;
211}
212
213static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
214 struct svc_serv *serv, struct rpc_xprt *xprt,
215 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
216{
217 if (minorversion) {
218 *rqstpp = nfs41_callback_up(serv, xprt);
219 *callback_svc = nfs41_callback_svc;
220 }
221 return minorversion;
222}
223
224static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
225 struct nfs_callback_data *cb_info)
226{
227 if (minorversion)
228 xprt->bc_serv = cb_info->serv;
229}
230#else
231static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
232 struct svc_serv *serv, struct rpc_xprt *xprt,
233 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
234{
235 return 0;
236}
237
238static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
239 struct nfs_callback_data *cb_info)
240{
241}
242#endif /* CONFIG_NFS_V4_1 */
243
244/*
245 * Bring up the callback thread if it is not already up.
246 */
247int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
248{
249 struct svc_serv *serv = NULL;
250 struct svc_rqst *rqstp;
251 int (*callback_svc)(void *vrqstp);
252 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
253 char svc_name[12];
254 int ret = 0;
255 int minorversion_setup;
256
257 mutex_lock(&nfs_callback_mutex);
258 if (cb_info->users++ || cb_info->task != NULL) {
259 nfs_callback_bc_serv(minorversion, xprt, cb_info);
260 goto out;
261 }
262 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
263 if (!serv) {
264 ret = -ENOMEM;
265 goto out_err;
266 }
267
268 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
269 serv, xprt, &rqstp, &callback_svc);
270 if (!minorversion_setup) {
271 /* v4.0 callback setup */
272 rqstp = nfs4_callback_up(serv);
273 callback_svc = nfs4_callback_svc;
274 }
275
276 if (IS_ERR(rqstp)) {
277 ret = PTR_ERR(rqstp);
278 goto out_err;
279 }
280
281 svc_sock_update_bufs(serv);
282
283 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
284 cb_info->serv = serv;
285 cb_info->rqst = rqstp;
286 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
287 if (IS_ERR(cb_info->task)) {
288 ret = PTR_ERR(cb_info->task);
289 svc_exit_thread(cb_info->rqst);
290 cb_info->rqst = NULL;
291 cb_info->task = NULL;
292 goto out_err;
293 }
294out:
295 /*
296 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
297 * svc_prepare_thread increments that. So we need to call svc_destroy
298 * on both success and failure so that the refcount is 1 when the
299 * thread exits.
300 */
301 if (serv)
302 svc_destroy(serv);
303 mutex_unlock(&nfs_callback_mutex);
304 return ret;
305out_err:
306 dprintk("NFS: Couldn't create callback socket or server thread; "
307 "err = %d\n", ret);
308 cb_info->users--;
309 goto out;
310}
311
312/*
313 * Kill the callback thread if it's no longer being used.
314 */
315void nfs_callback_down(int minorversion)
316{
317 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
318
319 mutex_lock(&nfs_callback_mutex);
320 cb_info->users--;
321 if (cb_info->users == 0 && cb_info->task != NULL) {
322 kthread_stop(cb_info->task);
323 svc_exit_thread(cb_info->rqst);
324 cb_info->serv = NULL;
325 cb_info->rqst = NULL;
326 cb_info->task = NULL;
327 }
328 mutex_unlock(&nfs_callback_mutex);
329}
330
331/* Boolean check of RPC_AUTH_GSS principal */
332int
333check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
334{
335 struct rpc_clnt *r = clp->cl_rpcclient;
336 char *p = svc_gss_principal(rqstp);
337
338 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
339 return 1;
340
341 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
342 if (clp->cl_minorversion != 0)
343 return 0;
344 /*
345 * It might just be a normal user principal, in which case
346 * userspace won't bother to tell us the name at all.
347 */
348 if (p == NULL)
349 return 0;
350
351 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
352
353 if (memcmp(p, "nfs@", 4) != 0)
354 return 0;
355 p += 4;
356 if (strcmp(p, r->cl_server) != 0)
357 return 0;
358 return 1;
359}
360
361/*
362 * pg_authenticate method for nfsv4 callback threads.
363 *
364 * The authflavor has been negotiated, so an incorrect flavor is a server
365 * bug. Drop packets with incorrect authflavor.
366 *
367 * All other checking done after NFS decoding where the nfs_client can be
368 * found in nfs4_callback_compound
369 */
370static int nfs_callback_authenticate(struct svc_rqst *rqstp)
371{
372 switch (rqstp->rq_authop->flavour) {
373 case RPC_AUTH_NULL:
374 if (rqstp->rq_proc != CB_NULL)
375 return SVC_DROP;
376 break;
377 case RPC_AUTH_GSS:
378 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
379 if (svc_is_backchannel(rqstp))
380 return SVC_DROP;
381 }
382 return SVC_OK;
383}
384
385/*
386 * Define NFS4 callback program
387 */
388static struct svc_version *nfs4_callback_version[] = {
389 [1] = &nfs4_callback_version1,
390 [4] = &nfs4_callback_version4,
391};
392
393static struct svc_stat nfs4_callback_stats;
394
395static struct svc_program nfs4_callback_program = {
396 .pg_prog = NFS4_CALLBACK, /* RPC service number */
397 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
398 .pg_vers = nfs4_callback_version, /* version table */
399 .pg_name = "NFSv4 callback", /* service name */
400 .pg_class = "nfs", /* authentication class */
401 .pg_stats = &nfs4_callback_stats,
402 .pg_authenticate = nfs_callback_authenticate,
403};
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};