1 /*
2 * linux/net/sunrpc/clnt.c
3 *
4 * This file contains the high-level RPC interface.
5 * It is modeled as a finite state machine to support both synchronous
6 * and asynchronous requests.
7 *
8 * - RPC header generation and argument serialization.
9 * - Credential refresh.
10 * - TCP connect handling.
11 * - Retry of operation when it is suspected the operation failed because
12 * of uid squashing on the server, or when the credentials were stale
13 * and need to be refreshed, or when a packet was damaged in transit.
14 * This may be have to be moved to the VFS layer.
15 *
16 * Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
17 * Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
18 */
19
20
21 #include <linux/module.h>
22 #include <linux/types.h>
23 #include <linux/kallsyms.h>
24 #include <linux/mm.h>
25 #include <linux/namei.h>
26 #include <linux/mount.h>
27 #include <linux/slab.h>
28 #include <linux/utsname.h>
29 #include <linux/workqueue.h>
30 #include <linux/in.h>
31 #include <linux/in6.h>
32 #include <linux/un.h>
33 #include <linux/rcupdate.h>
34
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/addr.h>
37 #include <linux/sunrpc/rpc_pipe_fs.h>
38 #include <linux/sunrpc/metrics.h>
39 #include <linux/sunrpc/bc_xprt.h>
40 #include <trace/events/sunrpc.h>
41
42 #include "sunrpc.h"
43 #include "netns.h"
44
45 #ifdef RPC_DEBUG
46 # define RPCDBG_FACILITY RPCDBG_CALL
47 #endif
48
49 #define dprint_status(t) \
50 dprintk("RPC: %5u %s (status %d)\n", t->tk_pid, \
51 __func__, t->tk_status)
52
53 /*
54 * All RPC clients are linked into this list
55 */
56
57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
58
59
60 static void call_start(struct rpc_task *task);
61 static void call_reserve(struct rpc_task *task);
62 static void call_reserveresult(struct rpc_task *task);
63 static void call_allocate(struct rpc_task *task);
64 static void call_decode(struct rpc_task *task);
65 static void call_bind(struct rpc_task *task);
66 static void call_bind_status(struct rpc_task *task);
67 static void call_transmit(struct rpc_task *task);
68 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
69 static void call_bc_transmit(struct rpc_task *task);
70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
71 static void call_status(struct rpc_task *task);
72 static void call_transmit_status(struct rpc_task *task);
73 static void call_refresh(struct rpc_task *task);
74 static void call_refreshresult(struct rpc_task *task);
75 static void call_timeout(struct rpc_task *task);
76 static void call_connect(struct rpc_task *task);
77 static void call_connect_status(struct rpc_task *task);
78
79 static __be32 *rpc_encode_header(struct rpc_task *task);
80 static __be32 *rpc_verify_header(struct rpc_task *task);
81 static int rpc_ping(struct rpc_clnt *clnt);
82
rpc_register_client(struct rpc_clnt * clnt)83 static void rpc_register_client(struct rpc_clnt *clnt)
84 {
85 struct net *net = rpc_net_ns(clnt);
86 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
87
88 spin_lock(&sn->rpc_client_lock);
89 list_add(&clnt->cl_clients, &sn->all_clients);
90 spin_unlock(&sn->rpc_client_lock);
91 }
92
rpc_unregister_client(struct rpc_clnt * clnt)93 static void rpc_unregister_client(struct rpc_clnt *clnt)
94 {
95 struct net *net = rpc_net_ns(clnt);
96 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
97
98 spin_lock(&sn->rpc_client_lock);
99 list_del(&clnt->cl_clients);
100 spin_unlock(&sn->rpc_client_lock);
101 }
102
__rpc_clnt_remove_pipedir(struct rpc_clnt * clnt)103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
104 {
105 if (clnt->cl_dentry) {
106 if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
107 clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
108 rpc_remove_client_dir(clnt->cl_dentry);
109 }
110 clnt->cl_dentry = NULL;
111 }
112
rpc_clnt_remove_pipedir(struct rpc_clnt * clnt)113 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
114 {
115 struct net *net = rpc_net_ns(clnt);
116 struct super_block *pipefs_sb;
117
118 pipefs_sb = rpc_get_sb_net(net);
119 if (pipefs_sb) {
120 __rpc_clnt_remove_pipedir(clnt);
121 rpc_put_sb_net(net);
122 }
123 }
124
rpc_setup_pipedir_sb(struct super_block * sb,struct rpc_clnt * clnt,const char * dir_name)125 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
126 struct rpc_clnt *clnt,
127 const char *dir_name)
128 {
129 static uint32_t clntid;
130 char name[15];
131 struct qstr q = { .name = name };
132 struct dentry *dir, *dentry;
133 int error;
134
135 dir = rpc_d_lookup_sb(sb, dir_name);
136 if (dir == NULL) {
137 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
138 return dir;
139 }
140 for (;;) {
141 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
142 name[sizeof(name) - 1] = '\0';
143 q.hash = full_name_hash(q.name, q.len);
144 dentry = rpc_create_client_dir(dir, &q, clnt);
145 if (!IS_ERR(dentry))
146 break;
147 error = PTR_ERR(dentry);
148 if (error != -EEXIST) {
149 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
150 " %s/%s, error %d\n",
151 dir_name, name, error);
152 break;
153 }
154 }
155 dput(dir);
156 return dentry;
157 }
158
159 static int
rpc_setup_pipedir(struct rpc_clnt * clnt,const char * dir_name)160 rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
161 {
162 struct net *net = rpc_net_ns(clnt);
163 struct super_block *pipefs_sb;
164 struct dentry *dentry;
165
166 clnt->cl_dentry = NULL;
167 if (dir_name == NULL)
168 return 0;
169 pipefs_sb = rpc_get_sb_net(net);
170 if (!pipefs_sb)
171 return 0;
172 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
173 rpc_put_sb_net(net);
174 if (IS_ERR(dentry))
175 return PTR_ERR(dentry);
176 clnt->cl_dentry = dentry;
177 return 0;
178 }
179
rpc_clnt_skip_event(struct rpc_clnt * clnt,unsigned long event)180 static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
181 {
182 if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
183 ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
184 return 1;
185 return 0;
186 }
187
__rpc_clnt_handle_event(struct rpc_clnt * clnt,unsigned long event,struct super_block * sb)188 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
189 struct super_block *sb)
190 {
191 struct dentry *dentry;
192 int err = 0;
193
194 switch (event) {
195 case RPC_PIPEFS_MOUNT:
196 dentry = rpc_setup_pipedir_sb(sb, clnt,
197 clnt->cl_program->pipe_dir_name);
198 if (!dentry)
199 return -ENOENT;
200 if (IS_ERR(dentry))
201 return PTR_ERR(dentry);
202 clnt->cl_dentry = dentry;
203 if (clnt->cl_auth->au_ops->pipes_create) {
204 err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
205 if (err)
206 __rpc_clnt_remove_pipedir(clnt);
207 }
208 break;
209 case RPC_PIPEFS_UMOUNT:
210 __rpc_clnt_remove_pipedir(clnt);
211 break;
212 default:
213 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
214 return -ENOTSUPP;
215 }
216 return err;
217 }
218
__rpc_pipefs_event(struct rpc_clnt * clnt,unsigned long event,struct super_block * sb)219 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
220 struct super_block *sb)
221 {
222 int error = 0;
223
224 for (;; clnt = clnt->cl_parent) {
225 if (!rpc_clnt_skip_event(clnt, event))
226 error = __rpc_clnt_handle_event(clnt, event, sb);
227 if (error || clnt == clnt->cl_parent)
228 break;
229 }
230 return error;
231 }
232
rpc_get_client_for_event(struct net * net,int event)233 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
234 {
235 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
236 struct rpc_clnt *clnt;
237
238 spin_lock(&sn->rpc_client_lock);
239 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
240 if (clnt->cl_program->pipe_dir_name == NULL)
241 continue;
242 if (rpc_clnt_skip_event(clnt, event))
243 continue;
244 if (atomic_inc_not_zero(&clnt->cl_count) == 0)
245 continue;
246 spin_unlock(&sn->rpc_client_lock);
247 return clnt;
248 }
249 spin_unlock(&sn->rpc_client_lock);
250 return NULL;
251 }
252
rpc_pipefs_event(struct notifier_block * nb,unsigned long event,void * ptr)253 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
254 void *ptr)
255 {
256 struct super_block *sb = ptr;
257 struct rpc_clnt *clnt;
258 int error = 0;
259
260 while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
261 error = __rpc_pipefs_event(clnt, event, sb);
262 rpc_release_client(clnt);
263 if (error)
264 break;
265 }
266 return error;
267 }
268
269 static struct notifier_block rpc_clients_block = {
270 .notifier_call = rpc_pipefs_event,
271 .priority = SUNRPC_PIPEFS_RPC_PRIO,
272 };
273
rpc_clients_notifier_register(void)274 int rpc_clients_notifier_register(void)
275 {
276 return rpc_pipefs_notifier_register(&rpc_clients_block);
277 }
278
rpc_clients_notifier_unregister(void)279 void rpc_clients_notifier_unregister(void)
280 {
281 return rpc_pipefs_notifier_unregister(&rpc_clients_block);
282 }
283
rpc_clnt_set_nodename(struct rpc_clnt * clnt,const char * nodename)284 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
285 {
286 clnt->cl_nodelen = strlen(nodename);
287 if (clnt->cl_nodelen > UNX_MAXNODENAME)
288 clnt->cl_nodelen = UNX_MAXNODENAME;
289 memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
290 }
291
rpc_new_client(const struct rpc_create_args * args,struct rpc_xprt * xprt)292 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
293 {
294 const struct rpc_program *program = args->program;
295 const struct rpc_version *version;
296 struct rpc_clnt *clnt = NULL;
297 struct rpc_auth *auth;
298 int err;
299
300 /* sanity check the name before trying to print it */
301 dprintk("RPC: creating %s client for %s (xprt %p)\n",
302 program->name, args->servername, xprt);
303
304 err = rpciod_up();
305 if (err)
306 goto out_no_rpciod;
307
308 err = -EINVAL;
309 if (args->version >= program->nrvers)
310 goto out_err;
311 version = program->version[args->version];
312 if (version == NULL)
313 goto out_err;
314
315 err = -ENOMEM;
316 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
317 if (!clnt)
318 goto out_err;
319 clnt->cl_parent = clnt;
320
321 rcu_assign_pointer(clnt->cl_xprt, xprt);
322 clnt->cl_procinfo = version->procs;
323 clnt->cl_maxproc = version->nrprocs;
324 clnt->cl_protname = program->name;
325 clnt->cl_prog = args->prognumber ? : program->number;
326 clnt->cl_vers = version->number;
327 clnt->cl_stats = program->stats;
328 clnt->cl_metrics = rpc_alloc_iostats(clnt);
329 err = -ENOMEM;
330 if (clnt->cl_metrics == NULL)
331 goto out_no_stats;
332 clnt->cl_program = program;
333 INIT_LIST_HEAD(&clnt->cl_tasks);
334 spin_lock_init(&clnt->cl_lock);
335
336 if (!xprt_bound(xprt))
337 clnt->cl_autobind = 1;
338
339 clnt->cl_timeout = xprt->timeout;
340 if (args->timeout != NULL) {
341 memcpy(&clnt->cl_timeout_default, args->timeout,
342 sizeof(clnt->cl_timeout_default));
343 clnt->cl_timeout = &clnt->cl_timeout_default;
344 }
345
346 clnt->cl_rtt = &clnt->cl_rtt_default;
347 rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
348 clnt->cl_principal = NULL;
349 if (args->client_name) {
350 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
351 if (!clnt->cl_principal)
352 goto out_no_principal;
353 }
354
355 atomic_set(&clnt->cl_count, 1);
356
357 err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
358 if (err < 0)
359 goto out_no_path;
360
361 auth = rpcauth_create(args->authflavor, clnt);
362 if (IS_ERR(auth)) {
363 dprintk("RPC: Couldn't create auth handle (flavor %u)\n",
364 args->authflavor);
365 err = PTR_ERR(auth);
366 goto out_no_auth;
367 }
368
369 /* save the nodename */
370 rpc_clnt_set_nodename(clnt, utsname()->nodename);
371 rpc_register_client(clnt);
372 return clnt;
373
374 out_no_auth:
375 rpc_clnt_remove_pipedir(clnt);
376 out_no_path:
377 kfree(clnt->cl_principal);
378 out_no_principal:
379 rpc_free_iostats(clnt->cl_metrics);
380 out_no_stats:
381 kfree(clnt);
382 out_err:
383 rpciod_down();
384 out_no_rpciod:
385 xprt_put(xprt);
386 return ERR_PTR(err);
387 }
388
389 /**
390 * rpc_create - create an RPC client and transport with one call
391 * @args: rpc_clnt create argument structure
392 *
393 * Creates and initializes an RPC transport and an RPC client.
394 *
395 * It can ping the server in order to determine if it is up, and to see if
396 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables
397 * this behavior so asynchronous tasks can also use rpc_create.
398 */
rpc_create(struct rpc_create_args * args)399 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
400 {
401 struct rpc_xprt *xprt;
402 struct rpc_clnt *clnt;
403 struct xprt_create xprtargs = {
404 .net = args->net,
405 .ident = args->protocol,
406 .srcaddr = args->saddress,
407 .dstaddr = args->address,
408 .addrlen = args->addrsize,
409 .servername = args->servername,
410 .bc_xprt = args->bc_xprt,
411 };
412 char servername[48];
413
414 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
415 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
416 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
417 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
418 /*
419 * If the caller chooses not to specify a hostname, whip
420 * up a string representation of the passed-in address.
421 */
422 if (xprtargs.servername == NULL) {
423 struct sockaddr_un *sun =
424 (struct sockaddr_un *)args->address;
425 struct sockaddr_in *sin =
426 (struct sockaddr_in *)args->address;
427 struct sockaddr_in6 *sin6 =
428 (struct sockaddr_in6 *)args->address;
429
430 servername[0] = '\0';
431 switch (args->address->sa_family) {
432 case AF_LOCAL:
433 snprintf(servername, sizeof(servername), "%s",
434 sun->sun_path);
435 break;
436 case AF_INET:
437 snprintf(servername, sizeof(servername), "%pI4",
438 &sin->sin_addr.s_addr);
439 break;
440 case AF_INET6:
441 snprintf(servername, sizeof(servername), "%pI6",
442 &sin6->sin6_addr);
443 break;
444 default:
445 /* caller wants default server name, but
446 * address family isn't recognized. */
447 return ERR_PTR(-EINVAL);
448 }
449 xprtargs.servername = servername;
450 }
451
452 xprt = xprt_create_transport(&xprtargs);
453 if (IS_ERR(xprt))
454 return (struct rpc_clnt *)xprt;
455
456 /*
457 * By default, kernel RPC client connects from a reserved port.
458 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
459 * but it is always enabled for rpciod, which handles the connect
460 * operation.
461 */
462 xprt->resvport = 1;
463 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
464 xprt->resvport = 0;
465
466 clnt = rpc_new_client(args, xprt);
467 if (IS_ERR(clnt))
468 return clnt;
469
470 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
471 int err = rpc_ping(clnt);
472 if (err != 0) {
473 rpc_shutdown_client(clnt);
474 return ERR_PTR(err);
475 }
476 }
477
478 clnt->cl_softrtry = 1;
479 if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
480 clnt->cl_softrtry = 0;
481
482 if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
483 clnt->cl_autobind = 1;
484 if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
485 clnt->cl_discrtry = 1;
486 if (!(args->flags & RPC_CLNT_CREATE_QUIET))
487 clnt->cl_chatty = 1;
488
489 return clnt;
490 }
491 EXPORT_SYMBOL_GPL(rpc_create);
492
493 /*
494 * This function clones the RPC client structure. It allows us to share the
495 * same transport while varying parameters such as the authentication
496 * flavour.
497 */
__rpc_clone_client(struct rpc_create_args * args,struct rpc_clnt * clnt)498 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
499 struct rpc_clnt *clnt)
500 {
501 struct rpc_xprt *xprt;
502 struct rpc_clnt *new;
503 int err;
504
505 err = -ENOMEM;
506 rcu_read_lock();
507 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
508 rcu_read_unlock();
509 if (xprt == NULL)
510 goto out_err;
511 args->servername = xprt->servername;
512
513 new = rpc_new_client(args, xprt);
514 if (IS_ERR(new)) {
515 err = PTR_ERR(new);
516 goto out_err;
517 }
518
519 atomic_inc(&clnt->cl_count);
520 new->cl_parent = clnt;
521
522 /* Turn off autobind on clones */
523 new->cl_autobind = 0;
524 new->cl_softrtry = clnt->cl_softrtry;
525 new->cl_discrtry = clnt->cl_discrtry;
526 new->cl_chatty = clnt->cl_chatty;
527 return new;
528
529 out_err:
530 dprintk("RPC: %s: returned error %d\n", __func__, err);
531 return ERR_PTR(err);
532 }
533
534 /**
535 * rpc_clone_client - Clone an RPC client structure
536 *
537 * @clnt: RPC client whose parameters are copied
538 *
539 * Returns a fresh RPC client or an ERR_PTR.
540 */
rpc_clone_client(struct rpc_clnt * clnt)541 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
542 {
543 struct rpc_create_args args = {
544 .program = clnt->cl_program,
545 .prognumber = clnt->cl_prog,
546 .version = clnt->cl_vers,
547 .authflavor = clnt->cl_auth->au_flavor,
548 .client_name = clnt->cl_principal,
549 };
550 return __rpc_clone_client(&args, clnt);
551 }
552 EXPORT_SYMBOL_GPL(rpc_clone_client);
553
554 /**
555 * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
556 *
557 * @clnt: RPC client whose parameters are copied
558 * @flavor: security flavor for new client
559 *
560 * Returns a fresh RPC client or an ERR_PTR.
561 */
562 struct rpc_clnt *
rpc_clone_client_set_auth(struct rpc_clnt * clnt,rpc_authflavor_t flavor)563 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
564 {
565 struct rpc_create_args args = {
566 .program = clnt->cl_program,
567 .prognumber = clnt->cl_prog,
568 .version = clnt->cl_vers,
569 .authflavor = flavor,
570 .client_name = clnt->cl_principal,
571 };
572 return __rpc_clone_client(&args, clnt);
573 }
574 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
575
576 /*
577 * Kill all tasks for the given client.
578 * XXX: kill their descendants as well?
579 */
rpc_killall_tasks(struct rpc_clnt * clnt)580 void rpc_killall_tasks(struct rpc_clnt *clnt)
581 {
582 struct rpc_task *rovr;
583
584
585 if (list_empty(&clnt->cl_tasks))
586 return;
587 dprintk("RPC: killing all tasks for client %p\n", clnt);
588 /*
589 * Spin lock all_tasks to prevent changes...
590 */
591 spin_lock(&clnt->cl_lock);
592 list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
593 if (!RPC_IS_ACTIVATED(rovr))
594 continue;
595 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
596 rovr->tk_flags |= RPC_TASK_KILLED;
597 rpc_exit(rovr, -EIO);
598 if (RPC_IS_QUEUED(rovr))
599 rpc_wake_up_queued_task(rovr->tk_waitqueue,
600 rovr);
601 }
602 }
603 spin_unlock(&clnt->cl_lock);
604 }
605 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
606
607 /*
608 * Properly shut down an RPC client, terminating all outstanding
609 * requests.
610 */
rpc_shutdown_client(struct rpc_clnt * clnt)611 void rpc_shutdown_client(struct rpc_clnt *clnt)
612 {
613 might_sleep();
614
615 dprintk_rcu("RPC: shutting down %s client for %s\n",
616 clnt->cl_protname,
617 rcu_dereference(clnt->cl_xprt)->servername);
618
619 while (!list_empty(&clnt->cl_tasks)) {
620 rpc_killall_tasks(clnt);
621 wait_event_timeout(destroy_wait,
622 list_empty(&clnt->cl_tasks), 1*HZ);
623 }
624
625 rpc_release_client(clnt);
626 }
627 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
628
629 /*
630 * Free an RPC client
631 */
632 static void
rpc_free_client(struct rpc_clnt * clnt)633 rpc_free_client(struct rpc_clnt *clnt)
634 {
635 dprintk_rcu("RPC: destroying %s client for %s\n",
636 clnt->cl_protname,
637 rcu_dereference(clnt->cl_xprt)->servername);
638 if (clnt->cl_parent != clnt)
639 rpc_release_client(clnt->cl_parent);
640 rpc_unregister_client(clnt);
641 rpc_clnt_remove_pipedir(clnt);
642 rpc_free_iostats(clnt->cl_metrics);
643 kfree(clnt->cl_principal);
644 clnt->cl_metrics = NULL;
645 xprt_put(rcu_dereference_raw(clnt->cl_xprt));
646 rpciod_down();
647 kfree(clnt);
648 }
649
650 /*
651 * Free an RPC client
652 */
653 static void
rpc_free_auth(struct rpc_clnt * clnt)654 rpc_free_auth(struct rpc_clnt *clnt)
655 {
656 if (clnt->cl_auth == NULL) {
657 rpc_free_client(clnt);
658 return;
659 }
660
661 /*
662 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
663 * release remaining GSS contexts. This mechanism ensures
664 * that it can do so safely.
665 */
666 atomic_inc(&clnt->cl_count);
667 rpcauth_release(clnt->cl_auth);
668 clnt->cl_auth = NULL;
669 if (atomic_dec_and_test(&clnt->cl_count))
670 rpc_free_client(clnt);
671 }
672
673 /*
674 * Release reference to the RPC client
675 */
676 void
rpc_release_client(struct rpc_clnt * clnt)677 rpc_release_client(struct rpc_clnt *clnt)
678 {
679 dprintk("RPC: rpc_release_client(%p)\n", clnt);
680
681 if (list_empty(&clnt->cl_tasks))
682 wake_up(&destroy_wait);
683 if (atomic_dec_and_test(&clnt->cl_count))
684 rpc_free_auth(clnt);
685 }
686 EXPORT_SYMBOL_GPL(rpc_release_client);
687
688 /**
689 * rpc_bind_new_program - bind a new RPC program to an existing client
690 * @old: old rpc_client
691 * @program: rpc program to set
692 * @vers: rpc program version
693 *
694 * Clones the rpc client and sets up a new RPC program. This is mainly
695 * of use for enabling different RPC programs to share the same transport.
696 * The Sun NFSv2/v3 ACL protocol can do this.
697 */
rpc_bind_new_program(struct rpc_clnt * old,const struct rpc_program * program,u32 vers)698 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
699 const struct rpc_program *program,
700 u32 vers)
701 {
702 struct rpc_create_args args = {
703 .program = program,
704 .prognumber = program->number,
705 .version = vers,
706 .authflavor = old->cl_auth->au_flavor,
707 .client_name = old->cl_principal,
708 };
709 struct rpc_clnt *clnt;
710 int err;
711
712 clnt = __rpc_clone_client(&args, old);
713 if (IS_ERR(clnt))
714 goto out;
715 err = rpc_ping(clnt);
716 if (err != 0) {
717 rpc_shutdown_client(clnt);
718 clnt = ERR_PTR(err);
719 }
720 out:
721 return clnt;
722 }
723 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
724
rpc_task_release_client(struct rpc_task * task)725 void rpc_task_release_client(struct rpc_task *task)
726 {
727 struct rpc_clnt *clnt = task->tk_client;
728
729 if (clnt != NULL) {
730 /* Remove from client task list */
731 spin_lock(&clnt->cl_lock);
732 list_del(&task->tk_task);
733 spin_unlock(&clnt->cl_lock);
734 task->tk_client = NULL;
735
736 rpc_release_client(clnt);
737 }
738 }
739
740 static
rpc_task_set_client(struct rpc_task * task,struct rpc_clnt * clnt)741 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
742 {
743 if (clnt != NULL) {
744 rpc_task_release_client(task);
745 task->tk_client = clnt;
746 atomic_inc(&clnt->cl_count);
747 if (clnt->cl_softrtry)
748 task->tk_flags |= RPC_TASK_SOFT;
749 if (sk_memalloc_socks()) {
750 struct rpc_xprt *xprt;
751
752 rcu_read_lock();
753 xprt = rcu_dereference(clnt->cl_xprt);
754 if (xprt->swapper)
755 task->tk_flags |= RPC_TASK_SWAPPER;
756 rcu_read_unlock();
757 }
758 /* Add to the client's list of all tasks */
759 spin_lock(&clnt->cl_lock);
760 list_add_tail(&task->tk_task, &clnt->cl_tasks);
761 spin_unlock(&clnt->cl_lock);
762 }
763 }
764
rpc_task_reset_client(struct rpc_task * task,struct rpc_clnt * clnt)765 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
766 {
767 rpc_task_release_client(task);
768 rpc_task_set_client(task, clnt);
769 }
770 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
771
772
773 static void
rpc_task_set_rpc_message(struct rpc_task * task,const struct rpc_message * msg)774 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
775 {
776 if (msg != NULL) {
777 task->tk_msg.rpc_proc = msg->rpc_proc;
778 task->tk_msg.rpc_argp = msg->rpc_argp;
779 task->tk_msg.rpc_resp = msg->rpc_resp;
780 if (msg->rpc_cred != NULL)
781 task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
782 }
783 }
784
785 /*
786 * Default callback for async RPC calls
787 */
788 static void
rpc_default_callback(struct rpc_task * task,void * data)789 rpc_default_callback(struct rpc_task *task, void *data)
790 {
791 }
792
793 static const struct rpc_call_ops rpc_default_ops = {
794 .rpc_call_done = rpc_default_callback,
795 };
796
797 /**
798 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
799 * @task_setup_data: pointer to task initialisation data
800 */
rpc_run_task(const struct rpc_task_setup * task_setup_data)801 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
802 {
803 struct rpc_task *task;
804
805 task = rpc_new_task(task_setup_data);
806 if (IS_ERR(task))
807 goto out;
808
809 rpc_task_set_client(task, task_setup_data->rpc_client);
810 rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
811
812 if (task->tk_action == NULL)
813 rpc_call_start(task);
814
815 atomic_inc(&task->tk_count);
816 rpc_execute(task);
817 out:
818 return task;
819 }
820 EXPORT_SYMBOL_GPL(rpc_run_task);
821
822 /**
823 * rpc_call_sync - Perform a synchronous RPC call
824 * @clnt: pointer to RPC client
825 * @msg: RPC call parameters
826 * @flags: RPC call flags
827 */
rpc_call_sync(struct rpc_clnt * clnt,const struct rpc_message * msg,int flags)828 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
829 {
830 struct rpc_task *task;
831 struct rpc_task_setup task_setup_data = {
832 .rpc_client = clnt,
833 .rpc_message = msg,
834 .callback_ops = &rpc_default_ops,
835 .flags = flags,
836 };
837 int status;
838
839 WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
840 if (flags & RPC_TASK_ASYNC) {
841 rpc_release_calldata(task_setup_data.callback_ops,
842 task_setup_data.callback_data);
843 return -EINVAL;
844 }
845
846 task = rpc_run_task(&task_setup_data);
847 if (IS_ERR(task))
848 return PTR_ERR(task);
849 status = task->tk_status;
850 rpc_put_task(task);
851 return status;
852 }
853 EXPORT_SYMBOL_GPL(rpc_call_sync);
854
855 /**
856 * rpc_call_async - Perform an asynchronous RPC call
857 * @clnt: pointer to RPC client
858 * @msg: RPC call parameters
859 * @flags: RPC call flags
860 * @tk_ops: RPC call ops
861 * @data: user call data
862 */
863 int
rpc_call_async(struct rpc_clnt * clnt,const struct rpc_message * msg,int flags,const struct rpc_call_ops * tk_ops,void * data)864 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
865 const struct rpc_call_ops *tk_ops, void *data)
866 {
867 struct rpc_task *task;
868 struct rpc_task_setup task_setup_data = {
869 .rpc_client = clnt,
870 .rpc_message = msg,
871 .callback_ops = tk_ops,
872 .callback_data = data,
873 .flags = flags|RPC_TASK_ASYNC,
874 };
875
876 task = rpc_run_task(&task_setup_data);
877 if (IS_ERR(task))
878 return PTR_ERR(task);
879 rpc_put_task(task);
880 return 0;
881 }
882 EXPORT_SYMBOL_GPL(rpc_call_async);
883
884 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
885 /**
886 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
887 * rpc_execute against it
888 * @req: RPC request
889 * @tk_ops: RPC call ops
890 */
rpc_run_bc_task(struct rpc_rqst * req,const struct rpc_call_ops * tk_ops)891 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
892 const struct rpc_call_ops *tk_ops)
893 {
894 struct rpc_task *task;
895 struct xdr_buf *xbufp = &req->rq_snd_buf;
896 struct rpc_task_setup task_setup_data = {
897 .callback_ops = tk_ops,
898 };
899
900 dprintk("RPC: rpc_run_bc_task req= %p\n", req);
901 /*
902 * Create an rpc_task to send the data
903 */
904 task = rpc_new_task(&task_setup_data);
905 if (IS_ERR(task)) {
906 xprt_free_bc_request(req);
907 goto out;
908 }
909 task->tk_rqstp = req;
910
911 /*
912 * Set up the xdr_buf length.
913 * This also indicates that the buffer is XDR encoded already.
914 */
915 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
916 xbufp->tail[0].iov_len;
917
918 task->tk_action = call_bc_transmit;
919 atomic_inc(&task->tk_count);
920 WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
921 rpc_execute(task);
922
923 out:
924 dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
925 return task;
926 }
927 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
928
929 void
rpc_call_start(struct rpc_task * task)930 rpc_call_start(struct rpc_task *task)
931 {
932 task->tk_action = call_start;
933 }
934 EXPORT_SYMBOL_GPL(rpc_call_start);
935
936 /**
937 * rpc_peeraddr - extract remote peer address from clnt's xprt
938 * @clnt: RPC client structure
939 * @buf: target buffer
940 * @bufsize: length of target buffer
941 *
942 * Returns the number of bytes that are actually in the stored address.
943 */
rpc_peeraddr(struct rpc_clnt * clnt,struct sockaddr * buf,size_t bufsize)944 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
945 {
946 size_t bytes;
947 struct rpc_xprt *xprt;
948
949 rcu_read_lock();
950 xprt = rcu_dereference(clnt->cl_xprt);
951
952 bytes = xprt->addrlen;
953 if (bytes > bufsize)
954 bytes = bufsize;
955 memcpy(buf, &xprt->addr, bytes);
956 rcu_read_unlock();
957
958 return bytes;
959 }
960 EXPORT_SYMBOL_GPL(rpc_peeraddr);
961
962 /**
963 * rpc_peeraddr2str - return remote peer address in printable format
964 * @clnt: RPC client structure
965 * @format: address format
966 *
967 * NB: the lifetime of the memory referenced by the returned pointer is
968 * the same as the rpc_xprt itself. As long as the caller uses this
969 * pointer, it must hold the RCU read lock.
970 */
rpc_peeraddr2str(struct rpc_clnt * clnt,enum rpc_display_format_t format)971 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
972 enum rpc_display_format_t format)
973 {
974 struct rpc_xprt *xprt;
975
976 xprt = rcu_dereference(clnt->cl_xprt);
977
978 if (xprt->address_strings[format] != NULL)
979 return xprt->address_strings[format];
980 else
981 return "unprintable";
982 }
983 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
984
985 static const struct sockaddr_in rpc_inaddr_loopback = {
986 .sin_family = AF_INET,
987 .sin_addr.s_addr = htonl(INADDR_ANY),
988 };
989
990 static const struct sockaddr_in6 rpc_in6addr_loopback = {
991 .sin6_family = AF_INET6,
992 .sin6_addr = IN6ADDR_ANY_INIT,
993 };
994
995 /*
996 * Try a getsockname() on a connected datagram socket. Using a
997 * connected datagram socket prevents leaving a socket in TIME_WAIT.
998 * This conserves the ephemeral port number space.
999 *
1000 * Returns zero and fills in "buf" if successful; otherwise, a
1001 * negative errno is returned.
1002 */
rpc_sockname(struct net * net,struct sockaddr * sap,size_t salen,struct sockaddr * buf,int buflen)1003 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1004 struct sockaddr *buf, int buflen)
1005 {
1006 struct socket *sock;
1007 int err;
1008
1009 err = __sock_create(net, sap->sa_family,
1010 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1011 if (err < 0) {
1012 dprintk("RPC: can't create UDP socket (%d)\n", err);
1013 goto out;
1014 }
1015
1016 switch (sap->sa_family) {
1017 case AF_INET:
1018 err = kernel_bind(sock,
1019 (struct sockaddr *)&rpc_inaddr_loopback,
1020 sizeof(rpc_inaddr_loopback));
1021 break;
1022 case AF_INET6:
1023 err = kernel_bind(sock,
1024 (struct sockaddr *)&rpc_in6addr_loopback,
1025 sizeof(rpc_in6addr_loopback));
1026 break;
1027 default:
1028 err = -EAFNOSUPPORT;
1029 goto out;
1030 }
1031 if (err < 0) {
1032 dprintk("RPC: can't bind UDP socket (%d)\n", err);
1033 goto out_release;
1034 }
1035
1036 err = kernel_connect(sock, sap, salen, 0);
1037 if (err < 0) {
1038 dprintk("RPC: can't connect UDP socket (%d)\n", err);
1039 goto out_release;
1040 }
1041
1042 err = kernel_getsockname(sock, buf, &buflen);
1043 if (err < 0) {
1044 dprintk("RPC: getsockname failed (%d)\n", err);
1045 goto out_release;
1046 }
1047
1048 err = 0;
1049 if (buf->sa_family == AF_INET6) {
1050 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1051 sin6->sin6_scope_id = 0;
1052 }
1053 dprintk("RPC: %s succeeded\n", __func__);
1054
1055 out_release:
1056 sock_release(sock);
1057 out:
1058 return err;
1059 }
1060
1061 /*
1062 * Scraping a connected socket failed, so we don't have a useable
1063 * local address. Fallback: generate an address that will prevent
1064 * the server from calling us back.
1065 *
1066 * Returns zero and fills in "buf" if successful; otherwise, a
1067 * negative errno is returned.
1068 */
rpc_anyaddr(int family,struct sockaddr * buf,size_t buflen)1069 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1070 {
1071 switch (family) {
1072 case AF_INET:
1073 if (buflen < sizeof(rpc_inaddr_loopback))
1074 return -EINVAL;
1075 memcpy(buf, &rpc_inaddr_loopback,
1076 sizeof(rpc_inaddr_loopback));
1077 break;
1078 case AF_INET6:
1079 if (buflen < sizeof(rpc_in6addr_loopback))
1080 return -EINVAL;
1081 memcpy(buf, &rpc_in6addr_loopback,
1082 sizeof(rpc_in6addr_loopback));
1083 default:
1084 dprintk("RPC: %s: address family not supported\n",
1085 __func__);
1086 return -EAFNOSUPPORT;
1087 }
1088 dprintk("RPC: %s: succeeded\n", __func__);
1089 return 0;
1090 }
1091
1092 /**
1093 * rpc_localaddr - discover local endpoint address for an RPC client
1094 * @clnt: RPC client structure
1095 * @buf: target buffer
1096 * @buflen: size of target buffer, in bytes
1097 *
1098 * Returns zero and fills in "buf" and "buflen" if successful;
1099 * otherwise, a negative errno is returned.
1100 *
1101 * This works even if the underlying transport is not currently connected,
1102 * or if the upper layer never previously provided a source address.
1103 *
1104 * The result of this function call is transient: multiple calls in
1105 * succession may give different results, depending on how local
1106 * networking configuration changes over time.
1107 */
rpc_localaddr(struct rpc_clnt * clnt,struct sockaddr * buf,size_t buflen)1108 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1109 {
1110 struct sockaddr_storage address;
1111 struct sockaddr *sap = (struct sockaddr *)&address;
1112 struct rpc_xprt *xprt;
1113 struct net *net;
1114 size_t salen;
1115 int err;
1116
1117 rcu_read_lock();
1118 xprt = rcu_dereference(clnt->cl_xprt);
1119 salen = xprt->addrlen;
1120 memcpy(sap, &xprt->addr, salen);
1121 net = get_net(xprt->xprt_net);
1122 rcu_read_unlock();
1123
1124 rpc_set_port(sap, 0);
1125 err = rpc_sockname(net, sap, salen, buf, buflen);
1126 put_net(net);
1127 if (err != 0)
1128 /* Couldn't discover local address, return ANYADDR */
1129 return rpc_anyaddr(sap->sa_family, buf, buflen);
1130 return 0;
1131 }
1132 EXPORT_SYMBOL_GPL(rpc_localaddr);
1133
1134 void
rpc_setbufsize(struct rpc_clnt * clnt,unsigned int sndsize,unsigned int rcvsize)1135 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1136 {
1137 struct rpc_xprt *xprt;
1138
1139 rcu_read_lock();
1140 xprt = rcu_dereference(clnt->cl_xprt);
1141 if (xprt->ops->set_buffer_size)
1142 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1143 rcu_read_unlock();
1144 }
1145 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1146
1147 /**
1148 * rpc_protocol - Get transport protocol number for an RPC client
1149 * @clnt: RPC client to query
1150 *
1151 */
rpc_protocol(struct rpc_clnt * clnt)1152 int rpc_protocol(struct rpc_clnt *clnt)
1153 {
1154 int protocol;
1155
1156 rcu_read_lock();
1157 protocol = rcu_dereference(clnt->cl_xprt)->prot;
1158 rcu_read_unlock();
1159 return protocol;
1160 }
1161 EXPORT_SYMBOL_GPL(rpc_protocol);
1162
1163 /**
1164 * rpc_net_ns - Get the network namespace for this RPC client
1165 * @clnt: RPC client to query
1166 *
1167 */
rpc_net_ns(struct rpc_clnt * clnt)1168 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1169 {
1170 struct net *ret;
1171
1172 rcu_read_lock();
1173 ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1174 rcu_read_unlock();
1175 return ret;
1176 }
1177 EXPORT_SYMBOL_GPL(rpc_net_ns);
1178
1179 /**
1180 * rpc_max_payload - Get maximum payload size for a transport, in bytes
1181 * @clnt: RPC client to query
1182 *
1183 * For stream transports, this is one RPC record fragment (see RFC
1184 * 1831), as we don't support multi-record requests yet. For datagram
1185 * transports, this is the size of an IP packet minus the IP, UDP, and
1186 * RPC header sizes.
1187 */
rpc_max_payload(struct rpc_clnt * clnt)1188 size_t rpc_max_payload(struct rpc_clnt *clnt)
1189 {
1190 size_t ret;
1191
1192 rcu_read_lock();
1193 ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1194 rcu_read_unlock();
1195 return ret;
1196 }
1197 EXPORT_SYMBOL_GPL(rpc_max_payload);
1198
1199 /**
1200 * rpc_get_timeout - Get timeout for transport in units of HZ
1201 * @clnt: RPC client to query
1202 */
rpc_get_timeout(struct rpc_clnt * clnt)1203 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1204 {
1205 unsigned long ret;
1206
1207 rcu_read_lock();
1208 ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1209 rcu_read_unlock();
1210 return ret;
1211 }
1212 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1213
1214 /**
1215 * rpc_force_rebind - force transport to check that remote port is unchanged
1216 * @clnt: client to rebind
1217 *
1218 */
rpc_force_rebind(struct rpc_clnt * clnt)1219 void rpc_force_rebind(struct rpc_clnt *clnt)
1220 {
1221 if (clnt->cl_autobind) {
1222 rcu_read_lock();
1223 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1224 rcu_read_unlock();
1225 }
1226 }
1227 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1228
1229 /*
1230 * Restart an (async) RPC call from the call_prepare state.
1231 * Usually called from within the exit handler.
1232 */
1233 int
rpc_restart_call_prepare(struct rpc_task * task)1234 rpc_restart_call_prepare(struct rpc_task *task)
1235 {
1236 if (RPC_ASSASSINATED(task))
1237 return 0;
1238 task->tk_action = call_start;
1239 if (task->tk_ops->rpc_call_prepare != NULL)
1240 task->tk_action = rpc_prepare_task;
1241 return 1;
1242 }
1243 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1244
1245 /*
1246 * Restart an (async) RPC call. Usually called from within the
1247 * exit handler.
1248 */
1249 int
rpc_restart_call(struct rpc_task * task)1250 rpc_restart_call(struct rpc_task *task)
1251 {
1252 if (RPC_ASSASSINATED(task))
1253 return 0;
1254 task->tk_action = call_start;
1255 return 1;
1256 }
1257 EXPORT_SYMBOL_GPL(rpc_restart_call);
1258
1259 #ifdef RPC_DEBUG
rpc_proc_name(const struct rpc_task * task)1260 static const char *rpc_proc_name(const struct rpc_task *task)
1261 {
1262 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1263
1264 if (proc) {
1265 if (proc->p_name)
1266 return proc->p_name;
1267 else
1268 return "NULL";
1269 } else
1270 return "no proc";
1271 }
1272 #endif
1273
1274 /*
1275 * 0. Initial state
1276 *
1277 * Other FSM states can be visited zero or more times, but
1278 * this state is visited exactly once for each RPC.
1279 */
1280 static void
call_start(struct rpc_task * task)1281 call_start(struct rpc_task *task)
1282 {
1283 struct rpc_clnt *clnt = task->tk_client;
1284
1285 dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1286 clnt->cl_protname, clnt->cl_vers,
1287 rpc_proc_name(task),
1288 (RPC_IS_ASYNC(task) ? "async" : "sync"));
1289
1290 /* Increment call count */
1291 task->tk_msg.rpc_proc->p_count++;
1292 clnt->cl_stats->rpccnt++;
1293 task->tk_action = call_reserve;
1294 }
1295
1296 /*
1297 * 1. Reserve an RPC call slot
1298 */
1299 static void
call_reserve(struct rpc_task * task)1300 call_reserve(struct rpc_task *task)
1301 {
1302 dprint_status(task);
1303
1304 task->tk_status = 0;
1305 task->tk_action = call_reserveresult;
1306 xprt_reserve(task);
1307 }
1308
1309 static void call_retry_reserve(struct rpc_task *task);
1310
1311 /*
1312 * 1b. Grok the result of xprt_reserve()
1313 */
1314 static void
call_reserveresult(struct rpc_task * task)1315 call_reserveresult(struct rpc_task *task)
1316 {
1317 int status = task->tk_status;
1318
1319 dprint_status(task);
1320
1321 /*
1322 * After a call to xprt_reserve(), we must have either
1323 * a request slot or else an error status.
1324 */
1325 task->tk_status = 0;
1326 if (status >= 0) {
1327 if (task->tk_rqstp) {
1328 task->tk_action = call_refresh;
1329 return;
1330 }
1331
1332 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1333 __func__, status);
1334 rpc_exit(task, -EIO);
1335 return;
1336 }
1337
1338 /*
1339 * Even though there was an error, we may have acquired
1340 * a request slot somehow. Make sure not to leak it.
1341 */
1342 if (task->tk_rqstp) {
1343 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1344 __func__, status);
1345 xprt_release(task);
1346 }
1347
1348 switch (status) {
1349 case -ENOMEM:
1350 rpc_delay(task, HZ >> 2);
1351 case -EAGAIN: /* woken up; retry */
1352 task->tk_action = call_retry_reserve;
1353 return;
1354 case -EIO: /* probably a shutdown */
1355 break;
1356 default:
1357 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1358 __func__, status);
1359 break;
1360 }
1361 rpc_exit(task, status);
1362 }
1363
1364 /*
1365 * 1c. Retry reserving an RPC call slot
1366 */
1367 static void
call_retry_reserve(struct rpc_task * task)1368 call_retry_reserve(struct rpc_task *task)
1369 {
1370 dprint_status(task);
1371
1372 task->tk_status = 0;
1373 task->tk_action = call_reserveresult;
1374 xprt_retry_reserve(task);
1375 }
1376
1377 /*
1378 * 2. Bind and/or refresh the credentials
1379 */
1380 static void
call_refresh(struct rpc_task * task)1381 call_refresh(struct rpc_task *task)
1382 {
1383 dprint_status(task);
1384
1385 task->tk_action = call_refreshresult;
1386 task->tk_status = 0;
1387 task->tk_client->cl_stats->rpcauthrefresh++;
1388 rpcauth_refreshcred(task);
1389 }
1390
1391 /*
1392 * 2a. Process the results of a credential refresh
1393 */
1394 static void
call_refreshresult(struct rpc_task * task)1395 call_refreshresult(struct rpc_task *task)
1396 {
1397 int status = task->tk_status;
1398
1399 dprint_status(task);
1400
1401 task->tk_status = 0;
1402 task->tk_action = call_refresh;
1403 switch (status) {
1404 case 0:
1405 if (rpcauth_uptodatecred(task))
1406 task->tk_action = call_allocate;
1407 return;
1408 case -ETIMEDOUT:
1409 rpc_delay(task, 3*HZ);
1410 case -EKEYEXPIRED:
1411 case -EAGAIN:
1412 status = -EACCES;
1413 if (!task->tk_cred_retry)
1414 break;
1415 task->tk_cred_retry--;
1416 dprintk("RPC: %5u %s: retry refresh creds\n",
1417 task->tk_pid, __func__);
1418 return;
1419 }
1420 dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1421 task->tk_pid, __func__, status);
1422 rpc_exit(task, status);
1423 }
1424
1425 /*
1426 * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc.
1427 * (Note: buffer memory is freed in xprt_release).
1428 */
1429 static void
call_allocate(struct rpc_task * task)1430 call_allocate(struct rpc_task *task)
1431 {
1432 unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1433 struct rpc_rqst *req = task->tk_rqstp;
1434 struct rpc_xprt *xprt = req->rq_xprt;
1435 struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1436
1437 dprint_status(task);
1438
1439 task->tk_status = 0;
1440 task->tk_action = call_bind;
1441
1442 if (req->rq_buffer)
1443 return;
1444
1445 if (proc->p_proc != 0) {
1446 BUG_ON(proc->p_arglen == 0);
1447 if (proc->p_decode != NULL)
1448 BUG_ON(proc->p_replen == 0);
1449 }
1450
1451 /*
1452 * Calculate the size (in quads) of the RPC call
1453 * and reply headers, and convert both values
1454 * to byte sizes.
1455 */
1456 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1457 req->rq_callsize <<= 2;
1458 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1459 req->rq_rcvsize <<= 2;
1460
1461 req->rq_buffer = xprt->ops->buf_alloc(task,
1462 req->rq_callsize + req->rq_rcvsize);
1463 if (req->rq_buffer != NULL)
1464 return;
1465
1466 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1467
1468 if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1469 task->tk_action = call_allocate;
1470 rpc_delay(task, HZ>>4);
1471 return;
1472 }
1473
1474 rpc_exit(task, -ERESTARTSYS);
1475 }
1476
1477 static inline int
rpc_task_need_encode(struct rpc_task * task)1478 rpc_task_need_encode(struct rpc_task *task)
1479 {
1480 return task->tk_rqstp->rq_snd_buf.len == 0;
1481 }
1482
1483 static inline void
rpc_task_force_reencode(struct rpc_task * task)1484 rpc_task_force_reencode(struct rpc_task *task)
1485 {
1486 task->tk_rqstp->rq_snd_buf.len = 0;
1487 task->tk_rqstp->rq_bytes_sent = 0;
1488 }
1489
1490 static inline void
rpc_xdr_buf_init(struct xdr_buf * buf,void * start,size_t len)1491 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1492 {
1493 buf->head[0].iov_base = start;
1494 buf->head[0].iov_len = len;
1495 buf->tail[0].iov_len = 0;
1496 buf->page_len = 0;
1497 buf->flags = 0;
1498 buf->len = 0;
1499 buf->buflen = len;
1500 }
1501
1502 /*
1503 * 3. Encode arguments of an RPC call
1504 */
1505 static void
rpc_xdr_encode(struct rpc_task * task)1506 rpc_xdr_encode(struct rpc_task *task)
1507 {
1508 struct rpc_rqst *req = task->tk_rqstp;
1509 kxdreproc_t encode;
1510 __be32 *p;
1511
1512 dprint_status(task);
1513
1514 rpc_xdr_buf_init(&req->rq_snd_buf,
1515 req->rq_buffer,
1516 req->rq_callsize);
1517 rpc_xdr_buf_init(&req->rq_rcv_buf,
1518 (char *)req->rq_buffer + req->rq_callsize,
1519 req->rq_rcvsize);
1520
1521 p = rpc_encode_header(task);
1522 if (p == NULL) {
1523 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1524 rpc_exit(task, -EIO);
1525 return;
1526 }
1527
1528 encode = task->tk_msg.rpc_proc->p_encode;
1529 if (encode == NULL)
1530 return;
1531
1532 task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1533 task->tk_msg.rpc_argp);
1534 }
1535
1536 /*
1537 * 4. Get the server port number if not yet set
1538 */
1539 static void
call_bind(struct rpc_task * task)1540 call_bind(struct rpc_task *task)
1541 {
1542 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1543
1544 dprint_status(task);
1545
1546 task->tk_action = call_connect;
1547 if (!xprt_bound(xprt)) {
1548 task->tk_action = call_bind_status;
1549 task->tk_timeout = xprt->bind_timeout;
1550 xprt->ops->rpcbind(task);
1551 }
1552 }
1553
1554 /*
1555 * 4a. Sort out bind result
1556 */
1557 static void
call_bind_status(struct rpc_task * task)1558 call_bind_status(struct rpc_task *task)
1559 {
1560 int status = -EIO;
1561
1562 if (task->tk_status >= 0) {
1563 dprint_status(task);
1564 task->tk_status = 0;
1565 task->tk_action = call_connect;
1566 return;
1567 }
1568
1569 trace_rpc_bind_status(task);
1570 switch (task->tk_status) {
1571 case -ENOMEM:
1572 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1573 rpc_delay(task, HZ >> 2);
1574 goto retry_timeout;
1575 case -EACCES:
1576 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1577 "unavailable\n", task->tk_pid);
1578 /* fail immediately if this is an RPC ping */
1579 if (task->tk_msg.rpc_proc->p_proc == 0) {
1580 status = -EOPNOTSUPP;
1581 break;
1582 }
1583 if (task->tk_rebind_retry == 0)
1584 break;
1585 task->tk_rebind_retry--;
1586 rpc_delay(task, 3*HZ);
1587 goto retry_timeout;
1588 case -ETIMEDOUT:
1589 dprintk("RPC: %5u rpcbind request timed out\n",
1590 task->tk_pid);
1591 goto retry_timeout;
1592 case -EPFNOSUPPORT:
1593 /* server doesn't support any rpcbind version we know of */
1594 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1595 task->tk_pid);
1596 break;
1597 case -EPROTONOSUPPORT:
1598 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1599 task->tk_pid);
1600 task->tk_status = 0;
1601 task->tk_action = call_bind;
1602 return;
1603 case -ECONNREFUSED: /* connection problems */
1604 case -ECONNRESET:
1605 case -ENOTCONN:
1606 case -EHOSTDOWN:
1607 case -EHOSTUNREACH:
1608 case -ENETUNREACH:
1609 case -EPIPE:
1610 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1611 task->tk_pid, task->tk_status);
1612 if (!RPC_IS_SOFTCONN(task)) {
1613 rpc_delay(task, 5*HZ);
1614 goto retry_timeout;
1615 }
1616 status = task->tk_status;
1617 break;
1618 default:
1619 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1620 task->tk_pid, -task->tk_status);
1621 }
1622
1623 rpc_exit(task, status);
1624 return;
1625
1626 retry_timeout:
1627 task->tk_action = call_timeout;
1628 }
1629
1630 /*
1631 * 4b. Connect to the RPC server
1632 */
1633 static void
call_connect(struct rpc_task * task)1634 call_connect(struct rpc_task *task)
1635 {
1636 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1637
1638 dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1639 task->tk_pid, xprt,
1640 (xprt_connected(xprt) ? "is" : "is not"));
1641
1642 task->tk_action = call_transmit;
1643 if (!xprt_connected(xprt)) {
1644 task->tk_action = call_connect_status;
1645 if (task->tk_status < 0)
1646 return;
1647 xprt_connect(task);
1648 }
1649 }
1650
1651 /*
1652 * 4c. Sort out connect result
1653 */
1654 static void
call_connect_status(struct rpc_task * task)1655 call_connect_status(struct rpc_task *task)
1656 {
1657 struct rpc_clnt *clnt = task->tk_client;
1658 int status = task->tk_status;
1659
1660 dprint_status(task);
1661
1662 trace_rpc_connect_status(task, status);
1663 switch (status) {
1664 /* if soft mounted, test if we've timed out */
1665 case -ETIMEDOUT:
1666 task->tk_action = call_timeout;
1667 return;
1668 case -ECONNREFUSED:
1669 case -ECONNRESET:
1670 case -ENETUNREACH:
1671 if (RPC_IS_SOFTCONN(task))
1672 break;
1673 /* retry with existing socket, after a delay */
1674 case 0:
1675 case -EAGAIN:
1676 task->tk_status = 0;
1677 clnt->cl_stats->netreconn++;
1678 task->tk_action = call_transmit;
1679 return;
1680 }
1681 rpc_exit(task, status);
1682 }
1683
1684 /*
1685 * 5. Transmit the RPC request, and wait for reply
1686 */
1687 static void
call_transmit(struct rpc_task * task)1688 call_transmit(struct rpc_task *task)
1689 {
1690 dprint_status(task);
1691
1692 task->tk_action = call_status;
1693 if (task->tk_status < 0)
1694 return;
1695 task->tk_status = xprt_prepare_transmit(task);
1696 if (task->tk_status != 0)
1697 return;
1698 task->tk_action = call_transmit_status;
1699 /* Encode here so that rpcsec_gss can use correct sequence number. */
1700 if (rpc_task_need_encode(task)) {
1701 rpc_xdr_encode(task);
1702 /* Did the encode result in an error condition? */
1703 if (task->tk_status != 0) {
1704 /* Was the error nonfatal? */
1705 if (task->tk_status == -EAGAIN)
1706 rpc_delay(task, HZ >> 4);
1707 else
1708 rpc_exit(task, task->tk_status);
1709 return;
1710 }
1711 }
1712 xprt_transmit(task);
1713 if (task->tk_status < 0)
1714 return;
1715 /*
1716 * On success, ensure that we call xprt_end_transmit() before sleeping
1717 * in order to allow access to the socket to other RPC requests.
1718 */
1719 call_transmit_status(task);
1720 if (rpc_reply_expected(task))
1721 return;
1722 task->tk_action = rpc_exit_task;
1723 rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1724 }
1725
1726 /*
1727 * 5a. Handle cleanup after a transmission
1728 */
1729 static void
call_transmit_status(struct rpc_task * task)1730 call_transmit_status(struct rpc_task *task)
1731 {
1732 task->tk_action = call_status;
1733
1734 /*
1735 * Common case: success. Force the compiler to put this
1736 * test first.
1737 */
1738 if (task->tk_status == 0) {
1739 xprt_end_transmit(task);
1740 rpc_task_force_reencode(task);
1741 return;
1742 }
1743
1744 switch (task->tk_status) {
1745 case -EAGAIN:
1746 break;
1747 default:
1748 dprint_status(task);
1749 xprt_end_transmit(task);
1750 rpc_task_force_reencode(task);
1751 break;
1752 /*
1753 * Special cases: if we've been waiting on the
1754 * socket's write_space() callback, or if the
1755 * socket just returned a connection error,
1756 * then hold onto the transport lock.
1757 */
1758 case -ECONNREFUSED:
1759 case -EHOSTDOWN:
1760 case -EHOSTUNREACH:
1761 case -ENETUNREACH:
1762 if (RPC_IS_SOFTCONN(task)) {
1763 xprt_end_transmit(task);
1764 rpc_exit(task, task->tk_status);
1765 break;
1766 }
1767 case -ECONNRESET:
1768 case -ENOTCONN:
1769 case -EPIPE:
1770 rpc_task_force_reencode(task);
1771 }
1772 }
1773
1774 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1775 /*
1776 * 5b. Send the backchannel RPC reply. On error, drop the reply. In
1777 * addition, disconnect on connectivity errors.
1778 */
1779 static void
call_bc_transmit(struct rpc_task * task)1780 call_bc_transmit(struct rpc_task *task)
1781 {
1782 struct rpc_rqst *req = task->tk_rqstp;
1783
1784 task->tk_status = xprt_prepare_transmit(task);
1785 if (task->tk_status == -EAGAIN) {
1786 /*
1787 * Could not reserve the transport. Try again after the
1788 * transport is released.
1789 */
1790 task->tk_status = 0;
1791 task->tk_action = call_bc_transmit;
1792 return;
1793 }
1794
1795 task->tk_action = rpc_exit_task;
1796 if (task->tk_status < 0) {
1797 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1798 "error: %d\n", task->tk_status);
1799 return;
1800 }
1801
1802 xprt_transmit(task);
1803 xprt_end_transmit(task);
1804 dprint_status(task);
1805 switch (task->tk_status) {
1806 case 0:
1807 /* Success */
1808 break;
1809 case -EHOSTDOWN:
1810 case -EHOSTUNREACH:
1811 case -ENETUNREACH:
1812 case -ETIMEDOUT:
1813 /*
1814 * Problem reaching the server. Disconnect and let the
1815 * forechannel reestablish the connection. The server will
1816 * have to retransmit the backchannel request and we'll
1817 * reprocess it. Since these ops are idempotent, there's no
1818 * need to cache our reply at this time.
1819 */
1820 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1821 "error: %d\n", task->tk_status);
1822 xprt_conditional_disconnect(req->rq_xprt,
1823 req->rq_connect_cookie);
1824 break;
1825 default:
1826 /*
1827 * We were unable to reply and will have to drop the
1828 * request. The server should reconnect and retransmit.
1829 */
1830 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1831 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1832 "error: %d\n", task->tk_status);
1833 break;
1834 }
1835 rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1836 }
1837 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1838
1839 /*
1840 * 6. Sort out the RPC call status
1841 */
1842 static void
call_status(struct rpc_task * task)1843 call_status(struct rpc_task *task)
1844 {
1845 struct rpc_clnt *clnt = task->tk_client;
1846 struct rpc_rqst *req = task->tk_rqstp;
1847 int status;
1848
1849 if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1850 task->tk_status = req->rq_reply_bytes_recvd;
1851
1852 dprint_status(task);
1853
1854 status = task->tk_status;
1855 if (status >= 0) {
1856 task->tk_action = call_decode;
1857 return;
1858 }
1859
1860 trace_rpc_call_status(task);
1861 task->tk_status = 0;
1862 switch(status) {
1863 case -EHOSTDOWN:
1864 case -EHOSTUNREACH:
1865 case -ENETUNREACH:
1866 /*
1867 * Delay any retries for 3 seconds, then handle as if it
1868 * were a timeout.
1869 */
1870 rpc_delay(task, 3*HZ);
1871 case -ETIMEDOUT:
1872 task->tk_action = call_timeout;
1873 if (task->tk_client->cl_discrtry)
1874 xprt_conditional_disconnect(req->rq_xprt,
1875 req->rq_connect_cookie);
1876 break;
1877 case -ECONNRESET:
1878 case -ECONNREFUSED:
1879 rpc_force_rebind(clnt);
1880 rpc_delay(task, 3*HZ);
1881 case -EPIPE:
1882 case -ENOTCONN:
1883 task->tk_action = call_bind;
1884 break;
1885 case -EAGAIN:
1886 task->tk_action = call_transmit;
1887 break;
1888 case -EIO:
1889 /* shutdown or soft timeout */
1890 rpc_exit(task, status);
1891 break;
1892 default:
1893 if (clnt->cl_chatty)
1894 printk("%s: RPC call returned error %d\n",
1895 clnt->cl_protname, -status);
1896 rpc_exit(task, status);
1897 }
1898 }
1899
1900 /*
1901 * 6a. Handle RPC timeout
1902 * We do not release the request slot, so we keep using the
1903 * same XID for all retransmits.
1904 */
1905 static void
call_timeout(struct rpc_task * task)1906 call_timeout(struct rpc_task *task)
1907 {
1908 struct rpc_clnt *clnt = task->tk_client;
1909
1910 if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1911 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1912 goto retry;
1913 }
1914
1915 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1916 task->tk_timeouts++;
1917
1918 if (RPC_IS_SOFTCONN(task)) {
1919 rpc_exit(task, -ETIMEDOUT);
1920 return;
1921 }
1922 if (RPC_IS_SOFT(task)) {
1923 if (clnt->cl_chatty) {
1924 rcu_read_lock();
1925 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1926 clnt->cl_protname,
1927 rcu_dereference(clnt->cl_xprt)->servername);
1928 rcu_read_unlock();
1929 }
1930 if (task->tk_flags & RPC_TASK_TIMEOUT)
1931 rpc_exit(task, -ETIMEDOUT);
1932 else
1933 rpc_exit(task, -EIO);
1934 return;
1935 }
1936
1937 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1938 task->tk_flags |= RPC_CALL_MAJORSEEN;
1939 if (clnt->cl_chatty) {
1940 rcu_read_lock();
1941 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1942 clnt->cl_protname,
1943 rcu_dereference(clnt->cl_xprt)->servername);
1944 rcu_read_unlock();
1945 }
1946 }
1947 rpc_force_rebind(clnt);
1948 /*
1949 * Did our request time out due to an RPCSEC_GSS out-of-sequence
1950 * event? RFC2203 requires the server to drop all such requests.
1951 */
1952 rpcauth_invalcred(task);
1953
1954 retry:
1955 clnt->cl_stats->rpcretrans++;
1956 task->tk_action = call_bind;
1957 task->tk_status = 0;
1958 }
1959
1960 /*
1961 * 7. Decode the RPC reply
1962 */
1963 static void
call_decode(struct rpc_task * task)1964 call_decode(struct rpc_task *task)
1965 {
1966 struct rpc_clnt *clnt = task->tk_client;
1967 struct rpc_rqst *req = task->tk_rqstp;
1968 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
1969 __be32 *p;
1970
1971 dprint_status(task);
1972
1973 if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1974 if (clnt->cl_chatty) {
1975 rcu_read_lock();
1976 printk(KERN_NOTICE "%s: server %s OK\n",
1977 clnt->cl_protname,
1978 rcu_dereference(clnt->cl_xprt)->servername);
1979 rcu_read_unlock();
1980 }
1981 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1982 }
1983
1984 /*
1985 * Ensure that we see all writes made by xprt_complete_rqst()
1986 * before it changed req->rq_reply_bytes_recvd.
1987 */
1988 smp_rmb();
1989 req->rq_rcv_buf.len = req->rq_private_buf.len;
1990
1991 /* Check that the softirq receive buffer is valid */
1992 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1993 sizeof(req->rq_rcv_buf)) != 0);
1994
1995 if (req->rq_rcv_buf.len < 12) {
1996 if (!RPC_IS_SOFT(task)) {
1997 task->tk_action = call_bind;
1998 clnt->cl_stats->rpcretrans++;
1999 goto out_retry;
2000 }
2001 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
2002 clnt->cl_protname, task->tk_status);
2003 task->tk_action = call_timeout;
2004 goto out_retry;
2005 }
2006
2007 p = rpc_verify_header(task);
2008 if (IS_ERR(p)) {
2009 if (p == ERR_PTR(-EAGAIN))
2010 goto out_retry;
2011 return;
2012 }
2013
2014 task->tk_action = rpc_exit_task;
2015
2016 if (decode) {
2017 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2018 task->tk_msg.rpc_resp);
2019 }
2020 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2021 task->tk_status);
2022 return;
2023 out_retry:
2024 task->tk_status = 0;
2025 /* Note: rpc_verify_header() may have freed the RPC slot */
2026 if (task->tk_rqstp == req) {
2027 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2028 if (task->tk_client->cl_discrtry)
2029 xprt_conditional_disconnect(req->rq_xprt,
2030 req->rq_connect_cookie);
2031 }
2032 }
2033
2034 static __be32 *
rpc_encode_header(struct rpc_task * task)2035 rpc_encode_header(struct rpc_task *task)
2036 {
2037 struct rpc_clnt *clnt = task->tk_client;
2038 struct rpc_rqst *req = task->tk_rqstp;
2039 __be32 *p = req->rq_svec[0].iov_base;
2040
2041 /* FIXME: check buffer size? */
2042
2043 p = xprt_skip_transport_header(req->rq_xprt, p);
2044 *p++ = req->rq_xid; /* XID */
2045 *p++ = htonl(RPC_CALL); /* CALL */
2046 *p++ = htonl(RPC_VERSION); /* RPC version */
2047 *p++ = htonl(clnt->cl_prog); /* program number */
2048 *p++ = htonl(clnt->cl_vers); /* program version */
2049 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
2050 p = rpcauth_marshcred(task, p);
2051 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2052 return p;
2053 }
2054
2055 static __be32 *
rpc_verify_header(struct rpc_task * task)2056 rpc_verify_header(struct rpc_task *task)
2057 {
2058 struct rpc_clnt *clnt = task->tk_client;
2059 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2060 int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2061 __be32 *p = iov->iov_base;
2062 u32 n;
2063 int error = -EACCES;
2064
2065 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2066 /* RFC-1014 says that the representation of XDR data must be a
2067 * multiple of four bytes
2068 * - if it isn't pointer subtraction in the NFS client may give
2069 * undefined results
2070 */
2071 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2072 " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2073 task->tk_rqstp->rq_rcv_buf.len);
2074 goto out_eio;
2075 }
2076 if ((len -= 3) < 0)
2077 goto out_overflow;
2078
2079 p += 1; /* skip XID */
2080 if ((n = ntohl(*p++)) != RPC_REPLY) {
2081 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2082 task->tk_pid, __func__, n);
2083 goto out_garbage;
2084 }
2085
2086 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2087 if (--len < 0)
2088 goto out_overflow;
2089 switch ((n = ntohl(*p++))) {
2090 case RPC_AUTH_ERROR:
2091 break;
2092 case RPC_MISMATCH:
2093 dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2094 task->tk_pid, __func__);
2095 error = -EPROTONOSUPPORT;
2096 goto out_err;
2097 default:
2098 dprintk("RPC: %5u %s: RPC call rejected, "
2099 "unknown error: %x\n",
2100 task->tk_pid, __func__, n);
2101 goto out_eio;
2102 }
2103 if (--len < 0)
2104 goto out_overflow;
2105 switch ((n = ntohl(*p++))) {
2106 case RPC_AUTH_REJECTEDCRED:
2107 case RPC_AUTH_REJECTEDVERF:
2108 case RPCSEC_GSS_CREDPROBLEM:
2109 case RPCSEC_GSS_CTXPROBLEM:
2110 if (!task->tk_cred_retry)
2111 break;
2112 task->tk_cred_retry--;
2113 dprintk("RPC: %5u %s: retry stale creds\n",
2114 task->tk_pid, __func__);
2115 rpcauth_invalcred(task);
2116 /* Ensure we obtain a new XID! */
2117 xprt_release(task);
2118 task->tk_action = call_reserve;
2119 goto out_retry;
2120 case RPC_AUTH_BADCRED:
2121 case RPC_AUTH_BADVERF:
2122 /* possibly garbled cred/verf? */
2123 if (!task->tk_garb_retry)
2124 break;
2125 task->tk_garb_retry--;
2126 dprintk("RPC: %5u %s: retry garbled creds\n",
2127 task->tk_pid, __func__);
2128 task->tk_action = call_bind;
2129 goto out_retry;
2130 case RPC_AUTH_TOOWEAK:
2131 rcu_read_lock();
2132 printk(KERN_NOTICE "RPC: server %s requires stronger "
2133 "authentication.\n",
2134 rcu_dereference(clnt->cl_xprt)->servername);
2135 rcu_read_unlock();
2136 break;
2137 default:
2138 dprintk("RPC: %5u %s: unknown auth error: %x\n",
2139 task->tk_pid, __func__, n);
2140 error = -EIO;
2141 }
2142 dprintk("RPC: %5u %s: call rejected %d\n",
2143 task->tk_pid, __func__, n);
2144 goto out_err;
2145 }
2146 if (!(p = rpcauth_checkverf(task, p))) {
2147 dprintk("RPC: %5u %s: auth check failed\n",
2148 task->tk_pid, __func__);
2149 goto out_garbage; /* bad verifier, retry */
2150 }
2151 len = p - (__be32 *)iov->iov_base - 1;
2152 if (len < 0)
2153 goto out_overflow;
2154 switch ((n = ntohl(*p++))) {
2155 case RPC_SUCCESS:
2156 return p;
2157 case RPC_PROG_UNAVAIL:
2158 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2159 "by server %s\n", task->tk_pid, __func__,
2160 (unsigned int)clnt->cl_prog,
2161 rcu_dereference(clnt->cl_xprt)->servername);
2162 error = -EPFNOSUPPORT;
2163 goto out_err;
2164 case RPC_PROG_MISMATCH:
2165 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2166 "by server %s\n", task->tk_pid, __func__,
2167 (unsigned int)clnt->cl_prog,
2168 (unsigned int)clnt->cl_vers,
2169 rcu_dereference(clnt->cl_xprt)->servername);
2170 error = -EPROTONOSUPPORT;
2171 goto out_err;
2172 case RPC_PROC_UNAVAIL:
2173 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2174 "version %u on server %s\n",
2175 task->tk_pid, __func__,
2176 rpc_proc_name(task),
2177 clnt->cl_prog, clnt->cl_vers,
2178 rcu_dereference(clnt->cl_xprt)->servername);
2179 error = -EOPNOTSUPP;
2180 goto out_err;
2181 case RPC_GARBAGE_ARGS:
2182 dprintk("RPC: %5u %s: server saw garbage\n",
2183 task->tk_pid, __func__);
2184 break; /* retry */
2185 default:
2186 dprintk("RPC: %5u %s: server accept status: %x\n",
2187 task->tk_pid, __func__, n);
2188 /* Also retry */
2189 }
2190
2191 out_garbage:
2192 clnt->cl_stats->rpcgarbage++;
2193 if (task->tk_garb_retry) {
2194 task->tk_garb_retry--;
2195 dprintk("RPC: %5u %s: retrying\n",
2196 task->tk_pid, __func__);
2197 task->tk_action = call_bind;
2198 out_retry:
2199 return ERR_PTR(-EAGAIN);
2200 }
2201 out_eio:
2202 error = -EIO;
2203 out_err:
2204 rpc_exit(task, error);
2205 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2206 __func__, error);
2207 return ERR_PTR(error);
2208 out_overflow:
2209 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2210 __func__);
2211 goto out_garbage;
2212 }
2213
rpcproc_encode_null(void * rqstp,struct xdr_stream * xdr,void * obj)2214 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2215 {
2216 }
2217
rpcproc_decode_null(void * rqstp,struct xdr_stream * xdr,void * obj)2218 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2219 {
2220 return 0;
2221 }
2222
2223 static struct rpc_procinfo rpcproc_null = {
2224 .p_encode = rpcproc_encode_null,
2225 .p_decode = rpcproc_decode_null,
2226 };
2227
rpc_ping(struct rpc_clnt * clnt)2228 static int rpc_ping(struct rpc_clnt *clnt)
2229 {
2230 struct rpc_message msg = {
2231 .rpc_proc = &rpcproc_null,
2232 };
2233 int err;
2234 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2235 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2236 put_rpccred(msg.rpc_cred);
2237 return err;
2238 }
2239
rpc_call_null(struct rpc_clnt * clnt,struct rpc_cred * cred,int flags)2240 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2241 {
2242 struct rpc_message msg = {
2243 .rpc_proc = &rpcproc_null,
2244 .rpc_cred = cred,
2245 };
2246 struct rpc_task_setup task_setup_data = {
2247 .rpc_client = clnt,
2248 .rpc_message = &msg,
2249 .callback_ops = &rpc_default_ops,
2250 .flags = flags,
2251 };
2252 return rpc_run_task(&task_setup_data);
2253 }
2254 EXPORT_SYMBOL_GPL(rpc_call_null);
2255
2256 #ifdef RPC_DEBUG
rpc_show_header(void)2257 static void rpc_show_header(void)
2258 {
2259 printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2260 "-timeout ---ops--\n");
2261 }
2262
rpc_show_task(const struct rpc_clnt * clnt,const struct rpc_task * task)2263 static void rpc_show_task(const struct rpc_clnt *clnt,
2264 const struct rpc_task *task)
2265 {
2266 const char *rpc_waitq = "none";
2267
2268 if (RPC_IS_QUEUED(task))
2269 rpc_waitq = rpc_qname(task->tk_waitqueue);
2270
2271 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2272 task->tk_pid, task->tk_flags, task->tk_status,
2273 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2274 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2275 task->tk_action, rpc_waitq);
2276 }
2277
rpc_show_tasks(struct net * net)2278 void rpc_show_tasks(struct net *net)
2279 {
2280 struct rpc_clnt *clnt;
2281 struct rpc_task *task;
2282 int header = 0;
2283 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2284
2285 spin_lock(&sn->rpc_client_lock);
2286 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2287 spin_lock(&clnt->cl_lock);
2288 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2289 if (!header) {
2290 rpc_show_header();
2291 header++;
2292 }
2293 rpc_show_task(clnt, task);
2294 }
2295 spin_unlock(&clnt->cl_lock);
2296 }
2297 spin_unlock(&sn->rpc_client_lock);
2298 }
2299 #endif
2300