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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 "NFS: %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 */
104static struct svc_rqst *
105nfs4_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
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], NUMA_NO_NODE);
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 */
175static struct 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], NUMA_NO_NODE);
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 struct net *net = &init_net;
257
258 mutex_lock(&nfs_callback_mutex);
259 if (cb_info->users++ || cb_info->task != NULL) {
260 nfs_callback_bc_serv(minorversion, xprt, cb_info);
261 goto out;
262 }
263 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
264 if (!serv) {
265 ret = -ENOMEM;
266 goto out_err;
267 }
268
269 ret = svc_bind(serv, net);
270 if (ret < 0) {
271 printk(KERN_WARNING "NFS: bind callback service failed\n");
272 goto out_err;
273 }
274
275 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
276 serv, xprt, &rqstp, &callback_svc);
277 if (!minorversion_setup) {
278 /* v4.0 callback setup */
279 rqstp = nfs4_callback_up(serv, xprt);
280 callback_svc = nfs4_callback_svc;
281 }
282
283 if (IS_ERR(rqstp)) {
284 ret = PTR_ERR(rqstp);
285 goto out_err;
286 }
287
288 svc_sock_update_bufs(serv);
289
290 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
291 cb_info->serv = serv;
292 cb_info->rqst = rqstp;
293 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
294 if (IS_ERR(cb_info->task)) {
295 ret = PTR_ERR(cb_info->task);
296 svc_exit_thread(cb_info->rqst);
297 cb_info->rqst = NULL;
298 cb_info->task = NULL;
299 goto out_err;
300 }
301out:
302 /*
303 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
304 * svc_prepare_thread increments that. So we need to call svc_destroy
305 * on both success and failure so that the refcount is 1 when the
306 * thread exits.
307 */
308 if (serv)
309 svc_destroy(serv);
310 mutex_unlock(&nfs_callback_mutex);
311 return ret;
312out_err:
313 dprintk("NFS: Couldn't create callback socket or server thread; "
314 "err = %d\n", ret);
315 cb_info->users--;
316 if (serv)
317 svc_shutdown_net(serv, net);
318 goto out;
319}
320
321/*
322 * Kill the callback thread if it's no longer being used.
323 */
324void nfs_callback_down(int minorversion)
325{
326 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
327
328 mutex_lock(&nfs_callback_mutex);
329 cb_info->users--;
330 if (cb_info->users == 0 && cb_info->task != NULL) {
331 kthread_stop(cb_info->task);
332 svc_shutdown_net(cb_info->serv, &init_net);
333 svc_exit_thread(cb_info->rqst);
334 cb_info->serv = NULL;
335 cb_info->rqst = NULL;
336 cb_info->task = NULL;
337 }
338 mutex_unlock(&nfs_callback_mutex);
339}
340
341/* Boolean check of RPC_AUTH_GSS principal */
342int
343check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
344{
345 char *p = rqstp->rq_cred.cr_principal;
346
347 if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
348 return 1;
349
350 /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
351 if (clp->cl_minorversion != 0)
352 return 0;
353 /*
354 * It might just be a normal user principal, in which case
355 * userspace won't bother to tell us the name at all.
356 */
357 if (p == NULL)
358 return 0;
359
360 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
361
362 if (memcmp(p, "nfs@", 4) != 0)
363 return 0;
364 p += 4;
365 if (strcmp(p, clp->cl_hostname) != 0)
366 return 0;
367 return 1;
368}
369
370/*
371 * pg_authenticate method for nfsv4 callback threads.
372 *
373 * The authflavor has been negotiated, so an incorrect flavor is a server
374 * bug. Drop packets with incorrect authflavor.
375 *
376 * All other checking done after NFS decoding where the nfs_client can be
377 * found in nfs4_callback_compound
378 */
379static int nfs_callback_authenticate(struct svc_rqst *rqstp)
380{
381 switch (rqstp->rq_authop->flavour) {
382 case RPC_AUTH_NULL:
383 if (rqstp->rq_proc != CB_NULL)
384 return SVC_DROP;
385 break;
386 case RPC_AUTH_GSS:
387 /* No RPC_AUTH_GSS support yet in NFSv4.1 */
388 if (svc_is_backchannel(rqstp))
389 return SVC_DROP;
390 }
391 return SVC_OK;
392}
393
394/*
395 * Define NFS4 callback program
396 */
397static struct svc_version *nfs4_callback_version[] = {
398 [1] = &nfs4_callback_version1,
399 [4] = &nfs4_callback_version4,
400};
401
402static struct svc_stat nfs4_callback_stats;
403
404static struct svc_program nfs4_callback_program = {
405 .pg_prog = NFS4_CALLBACK, /* RPC service number */
406 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
407 .pg_vers = nfs4_callback_version, /* version table */
408 .pg_name = "NFSv4 callback", /* service name */
409 .pg_class = "nfs", /* authentication class */
410 .pg_stats = &nfs4_callback_stats,
411 .pg_authenticate = nfs_callback_authenticate,
412};
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};