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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/*
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};