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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/nfs/callback.c | |
3 | * | |
4 | * Copyright (C) 2004 Trond Myklebust | |
5 | * | |
6 | * NFSv4 callback handling | |
7 | */ | |
8 | ||
1da177e4 LT |
9 | #include <linux/completion.h> |
10 | #include <linux/ip.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/smp_lock.h> | |
13 | #include <linux/sunrpc/svc.h> | |
14 | #include <linux/sunrpc/svcsock.h> | |
15 | #include <linux/nfs_fs.h> | |
353ab6e9 | 16 | #include <linux/mutex.h> |
83144186 | 17 | #include <linux/freezer.h> |
a277e33c | 18 | #include <linux/kthread.h> |
945b34a7 | 19 | #include <linux/sunrpc/svcauth_gss.h> |
a43cde94 RL |
20 | #if defined(CONFIG_NFS_V4_1) |
21 | #include <linux/sunrpc/bc_xprt.h> | |
22 | #endif | |
14c85021 ACM |
23 | |
24 | #include <net/inet_sock.h> | |
25 | ||
4ce79717 | 26 | #include "nfs4_fs.h" |
1da177e4 | 27 | #include "callback.h" |
24c8dbbb | 28 | #include "internal.h" |
1da177e4 LT |
29 | |
30 | #define NFSDBG_FACILITY NFSDBG_CALLBACK | |
31 | ||
32 | struct nfs_callback_data { | |
33 | unsigned int users; | |
a43cde94 | 34 | struct svc_serv *serv; |
5afc597c | 35 | struct svc_rqst *rqst; |
a277e33c | 36 | struct task_struct *task; |
1da177e4 LT |
37 | }; |
38 | ||
e82dc22d | 39 | static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1]; |
353ab6e9 | 40 | static DEFINE_MUTEX(nfs_callback_mutex); |
1da177e4 LT |
41 | static struct svc_program nfs4_callback_program; |
42 | ||
a72b4422 | 43 | unsigned int nfs_callback_set_tcpport; |
1da177e4 | 44 | unsigned short nfs_callback_tcpport; |
f738f517 | 45 | unsigned short nfs_callback_tcpport6; |
7d4e2747 DH |
46 | static const int nfs_set_port_min = 0; |
47 | static const int nfs_set_port_max = 65535; | |
48 | ||
49 | static int param_set_port(const char *val, struct kernel_param *kp) | |
50 | { | |
51 | char *endp; | |
52 | int num = simple_strtol(val, &endp, 0); | |
53 | if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max) | |
54 | return -EINVAL; | |
55 | *((int *)kp->arg) = num; | |
56 | return 0; | |
57 | } | |
58 | ||
59 | module_param_call(callback_tcpport, param_set_port, param_get_int, | |
60 | &nfs_callback_set_tcpport, 0644); | |
1da177e4 LT |
61 | |
62 | /* | |
e82dc22d | 63 | * This is the NFSv4 callback kernel thread. |
1da177e4 | 64 | */ |
a277e33c | 65 | static int |
71468513 | 66 | nfs4_callback_svc(void *vrqstp) |
1da177e4 | 67 | { |
06e02d66 | 68 | int err, preverr = 0; |
a277e33c | 69 | struct svc_rqst *rqstp = vrqstp; |
1da177e4 | 70 | |
83144186 | 71 | set_freezable(); |
1da177e4 | 72 | |
a277e33c JL |
73 | /* |
74 | * FIXME: do we really need to run this under the BKL? If so, please | |
75 | * add a comment about what it's intended to protect. | |
76 | */ | |
77 | lock_kernel(); | |
78 | while (!kthread_should_stop()) { | |
1da177e4 LT |
79 | /* |
80 | * Listen for a request on the socket | |
81 | */ | |
6fb2b47f | 82 | err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT); |
06e02d66 JL |
83 | if (err == -EAGAIN || err == -EINTR) { |
84 | preverr = err; | |
1da177e4 | 85 | continue; |
06e02d66 | 86 | } |
1da177e4 | 87 | if (err < 0) { |
06e02d66 JL |
88 | if (err != preverr) { |
89 | printk(KERN_WARNING "%s: unexpected error " | |
90 | "from svc_recv (%d)\n", __func__, err); | |
91 | preverr = err; | |
92 | } | |
93 | schedule_timeout_uninterruptible(HZ); | |
94 | continue; | |
1da177e4 | 95 | } |
06e02d66 | 96 | preverr = err; |
6fb2b47f | 97 | svc_process(rqstp); |
1da177e4 | 98 | } |
1da177e4 | 99 | unlock_kernel(); |
a277e33c | 100 | return 0; |
1da177e4 LT |
101 | } |
102 | ||
103 | /* | |
71468513 | 104 | * Prepare to bring up the NFSv4 callback service |
1da177e4 | 105 | */ |
71468513 BH |
106 | struct svc_rqst * |
107 | nfs4_callback_up(struct svc_serv *serv) | |
1da177e4 | 108 | { |
71468513 | 109 | int ret; |
482fb94e | 110 | |
26298caa | 111 | ret = svc_create_xprt(serv, "tcp", PF_INET, |
9652ada3 | 112 | nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS); |
482fb94e | 113 | if (ret <= 0) |
8e60029f | 114 | goto out_err; |
482fb94e | 115 | nfs_callback_tcpport = ret; |
18de9735 | 116 | dprintk("NFS: Callback listener port = %u (af %u)\n", |
26298caa | 117 | nfs_callback_tcpport, PF_INET); |
482fb94e | 118 | |
f738f517 CL |
119 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) |
120 | ret = svc_create_xprt(serv, "tcp", PF_INET6, | |
121 | nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS); | |
122 | if (ret > 0) { | |
123 | nfs_callback_tcpport6 = ret; | |
124 | dprintk("NFS: Callback listener port = %u (af %u)\n", | |
125 | nfs_callback_tcpport6, PF_INET6); | |
18fc3164 CL |
126 | } else if (ret == -EAFNOSUPPORT) |
127 | ret = 0; | |
128 | else | |
f738f517 CL |
129 | goto out_err; |
130 | #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */ | |
131 | ||
71468513 BH |
132 | return svc_prepare_thread(serv, &serv->sv_pools[0]); |
133 | ||
134 | out_err: | |
135 | if (ret == 0) | |
136 | ret = -ENOMEM; | |
137 | return ERR_PTR(ret); | |
138 | } | |
139 | ||
a43cde94 RL |
140 | #if defined(CONFIG_NFS_V4_1) |
141 | /* | |
142 | * The callback service for NFSv4.1 callbacks | |
143 | */ | |
144 | static int | |
145 | nfs41_callback_svc(void *vrqstp) | |
146 | { | |
147 | struct svc_rqst *rqstp = vrqstp; | |
148 | struct svc_serv *serv = rqstp->rq_server; | |
149 | struct rpc_rqst *req; | |
150 | int error; | |
151 | DEFINE_WAIT(wq); | |
152 | ||
153 | set_freezable(); | |
154 | ||
155 | /* | |
156 | * FIXME: do we really need to run this under the BKL? If so, please | |
157 | * add a comment about what it's intended to protect. | |
158 | */ | |
159 | lock_kernel(); | |
160 | while (!kthread_should_stop()) { | |
161 | prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE); | |
162 | spin_lock_bh(&serv->sv_cb_lock); | |
163 | if (!list_empty(&serv->sv_cb_list)) { | |
164 | req = list_first_entry(&serv->sv_cb_list, | |
165 | struct rpc_rqst, rq_bc_list); | |
166 | list_del(&req->rq_bc_list); | |
167 | spin_unlock_bh(&serv->sv_cb_lock); | |
168 | dprintk("Invoking bc_svc_process()\n"); | |
169 | error = bc_svc_process(serv, req, rqstp); | |
170 | dprintk("bc_svc_process() returned w/ error code= %d\n", | |
171 | error); | |
172 | } else { | |
173 | spin_unlock_bh(&serv->sv_cb_lock); | |
174 | schedule(); | |
175 | } | |
176 | finish_wait(&serv->sv_cb_waitq, &wq); | |
177 | } | |
178 | unlock_kernel(); | |
a43cde94 RL |
179 | return 0; |
180 | } | |
181 | ||
182 | /* | |
183 | * Bring up the NFSv4.1 callback service | |
184 | */ | |
185 | struct svc_rqst * | |
186 | nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt) | |
187 | { | |
8f975242 BH |
188 | struct svc_xprt *bc_xprt; |
189 | struct svc_rqst *rqstp = ERR_PTR(-ENOMEM); | |
190 | ||
191 | dprintk("--> %s\n", __func__); | |
192 | /* Create a svc_sock for the service */ | |
193 | bc_xprt = svc_sock_create(serv, xprt->prot); | |
194 | if (!bc_xprt) | |
195 | goto out; | |
196 | ||
a43cde94 RL |
197 | /* |
198 | * Save the svc_serv in the transport so that it can | |
199 | * be referenced when the session backchannel is initialized | |
200 | */ | |
8f975242 | 201 | serv->bc_xprt = bc_xprt; |
a43cde94 RL |
202 | xprt->bc_serv = serv; |
203 | ||
204 | INIT_LIST_HEAD(&serv->sv_cb_list); | |
205 | spin_lock_init(&serv->sv_cb_lock); | |
206 | init_waitqueue_head(&serv->sv_cb_waitq); | |
8f975242 BH |
207 | rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]); |
208 | if (IS_ERR(rqstp)) | |
209 | svc_sock_destroy(bc_xprt); | |
210 | out: | |
211 | dprintk("--> %s return %p\n", __func__, rqstp); | |
212 | return rqstp; | |
a43cde94 RL |
213 | } |
214 | ||
215 | static inline int nfs_minorversion_callback_svc_setup(u32 minorversion, | |
216 | struct svc_serv *serv, struct rpc_xprt *xprt, | |
217 | struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp)) | |
218 | { | |
219 | if (minorversion) { | |
220 | *rqstpp = nfs41_callback_up(serv, xprt); | |
221 | *callback_svc = nfs41_callback_svc; | |
222 | } | |
223 | return minorversion; | |
224 | } | |
225 | ||
226 | static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, | |
227 | struct nfs_callback_data *cb_info) | |
228 | { | |
229 | if (minorversion) | |
230 | xprt->bc_serv = cb_info->serv; | |
231 | } | |
232 | #else | |
233 | static inline int nfs_minorversion_callback_svc_setup(u32 minorversion, | |
234 | struct svc_serv *serv, struct rpc_xprt *xprt, | |
235 | struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp)) | |
236 | { | |
237 | return 0; | |
238 | } | |
239 | ||
240 | static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, | |
241 | struct nfs_callback_data *cb_info) | |
242 | { | |
243 | } | |
244 | #endif /* CONFIG_NFS_V4_1 */ | |
245 | ||
71468513 BH |
246 | /* |
247 | * Bring up the callback thread if it is not already up. | |
248 | */ | |
249 | int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt) | |
250 | { | |
251 | struct svc_serv *serv = NULL; | |
252 | struct svc_rqst *rqstp; | |
253 | int (*callback_svc)(void *vrqstp); | |
e82dc22d | 254 | struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; |
71468513 BH |
255 | char svc_name[12]; |
256 | int ret = 0; | |
a43cde94 | 257 | int minorversion_setup; |
71468513 BH |
258 | |
259 | mutex_lock(&nfs_callback_mutex); | |
e82dc22d AA |
260 | if (cb_info->users++ || cb_info->task != NULL) { |
261 | nfs_callback_bc_serv(minorversion, xprt, cb_info); | |
71468513 | 262 | goto out; |
a43cde94 | 263 | } |
71468513 BH |
264 | serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL); |
265 | if (!serv) { | |
266 | ret = -ENOMEM; | |
267 | goto out_err; | |
268 | } | |
269 | ||
a43cde94 RL |
270 | minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion, |
271 | serv, xprt, &rqstp, &callback_svc); | |
272 | if (!minorversion_setup) { | |
273 | /* v4.0 callback setup */ | |
71468513 BH |
274 | rqstp = nfs4_callback_up(serv); |
275 | callback_svc = nfs4_callback_svc; | |
71468513 BH |
276 | } |
277 | ||
278 | if (IS_ERR(rqstp)) { | |
279 | ret = PTR_ERR(rqstp); | |
8e60029f | 280 | goto out_err; |
a277e33c JL |
281 | } |
282 | ||
283 | svc_sock_update_bufs(serv); | |
a277e33c | 284 | |
71468513 | 285 | sprintf(svc_name, "nfsv4.%u-svc", minorversion); |
e82dc22d AA |
286 | cb_info->serv = serv; |
287 | cb_info->rqst = rqstp; | |
288 | cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name); | |
289 | if (IS_ERR(cb_info->task)) { | |
290 | ret = PTR_ERR(cb_info->task); | |
291 | svc_exit_thread(cb_info->rqst); | |
292 | cb_info->rqst = NULL; | |
293 | cb_info->task = NULL; | |
a277e33c JL |
294 | goto out_err; |
295 | } | |
1da177e4 | 296 | out: |
8e60029f JL |
297 | /* |
298 | * svc_create creates the svc_serv with sv_nrthreads == 1, and then | |
a277e33c | 299 | * svc_prepare_thread increments that. So we need to call svc_destroy |
8e60029f JL |
300 | * on both success and failure so that the refcount is 1 when the |
301 | * thread exits. | |
302 | */ | |
303 | if (serv) | |
304 | svc_destroy(serv); | |
353ab6e9 | 305 | mutex_unlock(&nfs_callback_mutex); |
1da177e4 | 306 | return ret; |
8e60029f | 307 | out_err: |
18de9735 CL |
308 | dprintk("NFS: Couldn't create callback socket or server thread; " |
309 | "err = %d\n", ret); | |
e82dc22d | 310 | cb_info->users--; |
1da177e4 LT |
311 | goto out; |
312 | } | |
313 | ||
314 | /* | |
5afc597c | 315 | * Kill the callback thread if it's no longer being used. |
1da177e4 | 316 | */ |
e82dc22d | 317 | void nfs_callback_down(int minorversion) |
1da177e4 | 318 | { |
e82dc22d AA |
319 | struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion]; |
320 | ||
353ab6e9 | 321 | mutex_lock(&nfs_callback_mutex); |
e82dc22d AA |
322 | cb_info->users--; |
323 | if (cb_info->users == 0 && cb_info->task != NULL) { | |
324 | kthread_stop(cb_info->task); | |
325 | svc_exit_thread(cb_info->rqst); | |
326 | cb_info->serv = NULL; | |
327 | cb_info->rqst = NULL; | |
328 | cb_info->task = NULL; | |
5afc597c | 329 | } |
353ab6e9 | 330 | mutex_unlock(&nfs_callback_mutex); |
1da177e4 LT |
331 | } |
332 | ||
945b34a7 OK |
333 | static int check_gss_callback_principal(struct nfs_client *clp, |
334 | struct svc_rqst *rqstp) | |
335 | { | |
336 | struct rpc_clnt *r = clp->cl_rpcclient; | |
337 | char *p = svc_gss_principal(rqstp); | |
338 | ||
339 | /* | |
340 | * It might just be a normal user principal, in which case | |
341 | * userspace won't bother to tell us the name at all. | |
342 | */ | |
343 | if (p == NULL) | |
344 | return SVC_DENIED; | |
345 | ||
346 | /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */ | |
347 | ||
348 | if (memcmp(p, "nfs@", 4) != 0) | |
349 | return SVC_DENIED; | |
350 | p += 4; | |
351 | if (strcmp(p, r->cl_server) != 0) | |
352 | return SVC_DENIED; | |
353 | return SVC_OK; | |
354 | } | |
355 | ||
1da177e4 LT |
356 | static int nfs_callback_authenticate(struct svc_rqst *rqstp) |
357 | { | |
adfa6f98 | 358 | struct nfs_client *clp; |
5216a8e7 | 359 | RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); |
945b34a7 | 360 | int ret = SVC_OK; |
1da177e4 LT |
361 | |
362 | /* Don't talk to strangers */ | |
ff052645 | 363 | clp = nfs_find_client(svc_addr(rqstp), 4); |
1da177e4 LT |
364 | if (clp == NULL) |
365 | return SVC_DROP; | |
ad06e4bd | 366 | |
3110ff80 | 367 | dprintk("%s: %s NFSv4 callback!\n", __func__, |
ad06e4bd | 368 | svc_print_addr(rqstp, buf, sizeof(buf))); |
ad06e4bd | 369 | |
1da177e4 LT |
370 | switch (rqstp->rq_authop->flavour) { |
371 | case RPC_AUTH_NULL: | |
372 | if (rqstp->rq_proc != CB_NULL) | |
945b34a7 | 373 | ret = SVC_DENIED; |
1da177e4 LT |
374 | break; |
375 | case RPC_AUTH_UNIX: | |
376 | break; | |
377 | case RPC_AUTH_GSS: | |
945b34a7 OK |
378 | ret = check_gss_callback_principal(clp, rqstp); |
379 | break; | |
1da177e4 | 380 | default: |
945b34a7 | 381 | ret = SVC_DENIED; |
1da177e4 | 382 | } |
945b34a7 OK |
383 | nfs_put_client(clp); |
384 | return ret; | |
1da177e4 LT |
385 | } |
386 | ||
387 | /* | |
388 | * Define NFS4 callback program | |
389 | */ | |
1da177e4 LT |
390 | static struct svc_version *nfs4_callback_version[] = { |
391 | [1] = &nfs4_callback_version1, | |
392 | }; | |
393 | ||
394 | static struct svc_stat nfs4_callback_stats; | |
395 | ||
396 | static struct svc_program nfs4_callback_program = { | |
397 | .pg_prog = NFS4_CALLBACK, /* RPC service number */ | |
398 | .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */ | |
399 | .pg_vers = nfs4_callback_version, /* version table */ | |
400 | .pg_name = "NFSv4 callback", /* service name */ | |
401 | .pg_class = "nfs", /* authentication class */ | |
402 | .pg_stats = &nfs4_callback_stats, | |
403 | .pg_authenticate = nfs_callback_authenticate, | |
404 | }; |