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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / net / sunrpc / clnt.c
blob7e0c9bf22df811475385496007cfac321e0422a5
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/rcupdate.h>
29 #include <linux/utsname.h>
30 #include <linux/workqueue.h>
31 #include <linux/in.h>
32 #include <linux/in6.h>
33 #include <linux/un.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 #if IS_ENABLED(CONFIG_SUNRPC_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
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
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
103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
104 {
105 rpc_remove_client_dir(clnt);
106 }
107
108 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
109 {
110 struct net *net = rpc_net_ns(clnt);
111 struct super_block *pipefs_sb;
112
113 pipefs_sb = rpc_get_sb_net(net);
114 if (pipefs_sb) {
115 __rpc_clnt_remove_pipedir(clnt);
116 rpc_put_sb_net(net);
117 }
118 }
119
120 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
121 struct rpc_clnt *clnt)
122 {
123 static uint32_t clntid;
124 const char *dir_name = clnt->cl_program->pipe_dir_name;
125 char name[15];
126 struct dentry *dir, *dentry;
127
128 dir = rpc_d_lookup_sb(sb, dir_name);
129 if (dir == NULL) {
130 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
131 return dir;
132 }
133 for (;;) {
134 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
135 name[sizeof(name) - 1] = '\0';
136 dentry = rpc_create_client_dir(dir, name, clnt);
137 if (!IS_ERR(dentry))
138 break;
139 if (dentry == ERR_PTR(-EEXIST))
140 continue;
141 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
142 " %s/%s, error %ld\n",
143 dir_name, name, PTR_ERR(dentry));
144 break;
145 }
146 dput(dir);
147 return dentry;
148 }
149
150 static int
151 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
152 {
153 struct dentry *dentry;
154
155 if (clnt->cl_program->pipe_dir_name != NULL) {
156 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
157 if (IS_ERR(dentry))
158 return PTR_ERR(dentry);
159 }
160 return 0;
161 }
162
163 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
164 {
165 if (clnt->cl_program->pipe_dir_name == NULL)
166 return 1;
167
168 switch (event) {
169 case RPC_PIPEFS_MOUNT:
170 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
171 return 1;
172 if (atomic_read(&clnt->cl_count) == 0)
173 return 1;
174 break;
175 case RPC_PIPEFS_UMOUNT:
176 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
177 return 1;
178 break;
179 }
180 return 0;
181 }
182
183 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
184 struct super_block *sb)
185 {
186 struct dentry *dentry;
187 int err = 0;
188
189 switch (event) {
190 case RPC_PIPEFS_MOUNT:
191 dentry = rpc_setup_pipedir_sb(sb, clnt);
192 if (!dentry)
193 return -ENOENT;
194 if (IS_ERR(dentry))
195 return PTR_ERR(dentry);
196 break;
197 case RPC_PIPEFS_UMOUNT:
198 __rpc_clnt_remove_pipedir(clnt);
199 break;
200 default:
201 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
202 return -ENOTSUPP;
203 }
204 return err;
205 }
206
207 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
208 struct super_block *sb)
209 {
210 int error = 0;
211
212 for (;; clnt = clnt->cl_parent) {
213 if (!rpc_clnt_skip_event(clnt, event))
214 error = __rpc_clnt_handle_event(clnt, event, sb);
215 if (error || clnt == clnt->cl_parent)
216 break;
217 }
218 return error;
219 }
220
221 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
222 {
223 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
224 struct rpc_clnt *clnt;
225
226 spin_lock(&sn->rpc_client_lock);
227 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
228 if (rpc_clnt_skip_event(clnt, event))
229 continue;
230 spin_unlock(&sn->rpc_client_lock);
231 return clnt;
232 }
233 spin_unlock(&sn->rpc_client_lock);
234 return NULL;
235 }
236
237 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
238 void *ptr)
239 {
240 struct super_block *sb = ptr;
241 struct rpc_clnt *clnt;
242 int error = 0;
243
244 while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
245 error = __rpc_pipefs_event(clnt, event, sb);
246 if (error)
247 break;
248 }
249 return error;
250 }
251
252 static struct notifier_block rpc_clients_block = {
253 .notifier_call = rpc_pipefs_event,
254 .priority = SUNRPC_PIPEFS_RPC_PRIO,
255 };
256
257 int rpc_clients_notifier_register(void)
258 {
259 return rpc_pipefs_notifier_register(&rpc_clients_block);
260 }
261
262 void rpc_clients_notifier_unregister(void)
263 {
264 return rpc_pipefs_notifier_unregister(&rpc_clients_block);
265 }
266
267 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
268 struct rpc_xprt *xprt,
269 const struct rpc_timeout *timeout)
270 {
271 struct rpc_xprt *old;
272
273 spin_lock(&clnt->cl_lock);
274 old = rcu_dereference_protected(clnt->cl_xprt,
275 lockdep_is_held(&clnt->cl_lock));
276
277 if (!xprt_bound(xprt))
278 clnt->cl_autobind = 1;
279
280 clnt->cl_timeout = timeout;
281 rcu_assign_pointer(clnt->cl_xprt, xprt);
282 spin_unlock(&clnt->cl_lock);
283
284 return old;
285 }
286
287 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
288 {
289 clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
290 nodename, sizeof(clnt->cl_nodename));
291 }
292
293 static int rpc_client_register(struct rpc_clnt *clnt,
294 rpc_authflavor_t pseudoflavor,
295 const char *client_name)
296 {
297 struct rpc_auth_create_args auth_args = {
298 .pseudoflavor = pseudoflavor,
299 .target_name = client_name,
300 };
301 struct rpc_auth *auth;
302 struct net *net = rpc_net_ns(clnt);
303 struct super_block *pipefs_sb;
304 int err;
305
306 rpc_clnt_debugfs_register(clnt);
307
308 pipefs_sb = rpc_get_sb_net(net);
309 if (pipefs_sb) {
310 err = rpc_setup_pipedir(pipefs_sb, clnt);
311 if (err)
312 goto out;
313 }
314
315 rpc_register_client(clnt);
316 if (pipefs_sb)
317 rpc_put_sb_net(net);
318
319 auth = rpcauth_create(&auth_args, clnt);
320 if (IS_ERR(auth)) {
321 dprintk("RPC: Couldn't create auth handle (flavor %u)\n",
322 pseudoflavor);
323 err = PTR_ERR(auth);
324 goto err_auth;
325 }
326 return 0;
327 err_auth:
328 pipefs_sb = rpc_get_sb_net(net);
329 rpc_unregister_client(clnt);
330 __rpc_clnt_remove_pipedir(clnt);
331 out:
332 if (pipefs_sb)
333 rpc_put_sb_net(net);
334 rpc_clnt_debugfs_unregister(clnt);
335 return err;
336 }
337
338 static DEFINE_IDA(rpc_clids);
339
340 static int rpc_alloc_clid(struct rpc_clnt *clnt)
341 {
342 int clid;
343
344 clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
345 if (clid < 0)
346 return clid;
347 clnt->cl_clid = clid;
348 return 0;
349 }
350
351 static void rpc_free_clid(struct rpc_clnt *clnt)
352 {
353 ida_simple_remove(&rpc_clids, clnt->cl_clid);
354 }
355
356 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
357 struct rpc_xprt_switch *xps,
358 struct rpc_xprt *xprt,
359 struct rpc_clnt *parent)
360 {
361 const struct rpc_program *program = args->program;
362 const struct rpc_version *version;
363 struct rpc_clnt *clnt = NULL;
364 const struct rpc_timeout *timeout;
365 const char *nodename = args->nodename;
366 int err;
367
368 /* sanity check the name before trying to print it */
369 dprintk("RPC: creating %s client for %s (xprt %p)\n",
370 program->name, args->servername, xprt);
371
372 err = rpciod_up();
373 if (err)
374 goto out_no_rpciod;
375
376 err = -EINVAL;
377 if (args->version >= program->nrvers)
378 goto out_err;
379 version = program->version[args->version];
380 if (version == NULL)
381 goto out_err;
382
383 err = -ENOMEM;
384 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
385 if (!clnt)
386 goto out_err;
387 clnt->cl_parent = parent ? : clnt;
388
389 err = rpc_alloc_clid(clnt);
390 if (err)
391 goto out_no_clid;
392
393 clnt->cl_procinfo = version->procs;
394 clnt->cl_maxproc = version->nrprocs;
395 clnt->cl_prog = args->prognumber ? : program->number;
396 clnt->cl_vers = version->number;
397 clnt->cl_stats = program->stats;
398 clnt->cl_metrics = rpc_alloc_iostats(clnt);
399 rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
400 err = -ENOMEM;
401 if (clnt->cl_metrics == NULL)
402 goto out_no_stats;
403 clnt->cl_program = program;
404 INIT_LIST_HEAD(&clnt->cl_tasks);
405 spin_lock_init(&clnt->cl_lock);
406
407 timeout = xprt->timeout;
408 if (args->timeout != NULL) {
409 memcpy(&clnt->cl_timeout_default, args->timeout,
410 sizeof(clnt->cl_timeout_default));
411 timeout = &clnt->cl_timeout_default;
412 }
413
414 rpc_clnt_set_transport(clnt, xprt, timeout);
415 xprt_iter_init(&clnt->cl_xpi, xps);
416 xprt_switch_put(xps);
417
418 clnt->cl_rtt = &clnt->cl_rtt_default;
419 rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
420
421 atomic_set(&clnt->cl_count, 1);
422
423 if (nodename == NULL)
424 nodename = utsname()->nodename;
425 /* save the nodename */
426 rpc_clnt_set_nodename(clnt, nodename);
427
428 err = rpc_client_register(clnt, args->authflavor, args->client_name);
429 if (err)
430 goto out_no_path;
431 if (parent)
432 atomic_inc(&parent->cl_count);
433 return clnt;
434
435 out_no_path:
436 rpc_free_iostats(clnt->cl_metrics);
437 out_no_stats:
438 rpc_free_clid(clnt);
439 out_no_clid:
440 kfree(clnt);
441 out_err:
442 rpciod_down();
443 out_no_rpciod:
444 xprt_switch_put(xps);
445 xprt_put(xprt);
446 return ERR_PTR(err);
447 }
448
449 struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
450 struct rpc_xprt *xprt)
451 {
452 struct rpc_clnt *clnt = NULL;
453 struct rpc_xprt_switch *xps;
454
455 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
456 if (xps == NULL)
457 return ERR_PTR(-ENOMEM);
458
459 clnt = rpc_new_client(args, xps, xprt, NULL);
460 if (IS_ERR(clnt))
461 return clnt;
462
463 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
464 int err = rpc_ping(clnt);
465 if (err != 0) {
466 rpc_shutdown_client(clnt);
467 return ERR_PTR(err);
468 }
469 }
470
471 clnt->cl_softrtry = 1;
472 if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
473 clnt->cl_softrtry = 0;
474
475 if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
476 clnt->cl_autobind = 1;
477 if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
478 clnt->cl_noretranstimeo = 1;
479 if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
480 clnt->cl_discrtry = 1;
481 if (!(args->flags & RPC_CLNT_CREATE_QUIET))
482 clnt->cl_chatty = 1;
483
484 return clnt;
485 }
486 EXPORT_SYMBOL_GPL(rpc_create_xprt);
487
488 /**
489 * rpc_create - create an RPC client and transport with one call
490 * @args: rpc_clnt create argument structure
491 *
492 * Creates and initializes an RPC transport and an RPC client.
493 *
494 * It can ping the server in order to determine if it is up, and to see if
495 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables
496 * this behavior so asynchronous tasks can also use rpc_create.
497 */
498 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
499 {
500 struct rpc_xprt *xprt;
501 struct xprt_create xprtargs = {
502 .net = args->net,
503 .ident = args->protocol,
504 .srcaddr = args->saddress,
505 .dstaddr = args->address,
506 .addrlen = args->addrsize,
507 .servername = args->servername,
508 .bc_xprt = args->bc_xprt,
509 };
510 char servername[48];
511
512 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
513 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
514 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
515 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
516 /*
517 * If the caller chooses not to specify a hostname, whip
518 * up a string representation of the passed-in address.
519 */
520 if (xprtargs.servername == NULL) {
521 struct sockaddr_un *sun =
522 (struct sockaddr_un *)args->address;
523 struct sockaddr_in *sin =
524 (struct sockaddr_in *)args->address;
525 struct sockaddr_in6 *sin6 =
526 (struct sockaddr_in6 *)args->address;
527
528 servername[0] = '\0';
529 switch (args->address->sa_family) {
530 case AF_LOCAL:
531 snprintf(servername, sizeof(servername), "%s",
532 sun->sun_path);
533 break;
534 case AF_INET:
535 snprintf(servername, sizeof(servername), "%pI4",
536 &sin->sin_addr.s_addr);
537 break;
538 case AF_INET6:
539 snprintf(servername, sizeof(servername), "%pI6",
540 &sin6->sin6_addr);
541 break;
542 default:
543 /* caller wants default server name, but
544 * address family isn't recognized. */
545 return ERR_PTR(-EINVAL);
546 }
547 xprtargs.servername = servername;
548 }
549
550 xprt = xprt_create_transport(&xprtargs);
551 if (IS_ERR(xprt))
552 return (struct rpc_clnt *)xprt;
553
554 /*
555 * By default, kernel RPC client connects from a reserved port.
556 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
557 * but it is always enabled for rpciod, which handles the connect
558 * operation.
559 */
560 xprt->resvport = 1;
561 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
562 xprt->resvport = 0;
563
564 return rpc_create_xprt(args, xprt);
565 }
566 EXPORT_SYMBOL_GPL(rpc_create);
567
568 /*
569 * This function clones the RPC client structure. It allows us to share the
570 * same transport while varying parameters such as the authentication
571 * flavour.
572 */
573 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
574 struct rpc_clnt *clnt)
575 {
576 struct rpc_xprt_switch *xps;
577 struct rpc_xprt *xprt;
578 struct rpc_clnt *new;
579 int err;
580
581 err = -ENOMEM;
582 rcu_read_lock();
583 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
584 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
585 rcu_read_unlock();
586 if (xprt == NULL || xps == NULL) {
587 xprt_put(xprt);
588 xprt_switch_put(xps);
589 goto out_err;
590 }
591 args->servername = xprt->servername;
592 args->nodename = clnt->cl_nodename;
593
594 new = rpc_new_client(args, xps, xprt, clnt);
595 if (IS_ERR(new)) {
596 err = PTR_ERR(new);
597 goto out_err;
598 }
599
600 /* Turn off autobind on clones */
601 new->cl_autobind = 0;
602 new->cl_softrtry = clnt->cl_softrtry;
603 new->cl_noretranstimeo = clnt->cl_noretranstimeo;
604 new->cl_discrtry = clnt->cl_discrtry;
605 new->cl_chatty = clnt->cl_chatty;
606 return new;
607
608 out_err:
609 dprintk("RPC: %s: returned error %d\n", __func__, err);
610 return ERR_PTR(err);
611 }
612
613 /**
614 * rpc_clone_client - Clone an RPC client structure
615 *
616 * @clnt: RPC client whose parameters are copied
617 *
618 * Returns a fresh RPC client or an ERR_PTR.
619 */
620 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
621 {
622 struct rpc_create_args args = {
623 .program = clnt->cl_program,
624 .prognumber = clnt->cl_prog,
625 .version = clnt->cl_vers,
626 .authflavor = clnt->cl_auth->au_flavor,
627 };
628 return __rpc_clone_client(&args, clnt);
629 }
630 EXPORT_SYMBOL_GPL(rpc_clone_client);
631
632 /**
633 * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
634 *
635 * @clnt: RPC client whose parameters are copied
636 * @flavor: security flavor for new client
637 *
638 * Returns a fresh RPC client or an ERR_PTR.
639 */
640 struct rpc_clnt *
641 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
642 {
643 struct rpc_create_args args = {
644 .program = clnt->cl_program,
645 .prognumber = clnt->cl_prog,
646 .version = clnt->cl_vers,
647 .authflavor = flavor,
648 };
649 return __rpc_clone_client(&args, clnt);
650 }
651 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
652
653 /**
654 * rpc_switch_client_transport: switch the RPC transport on the fly
655 * @clnt: pointer to a struct rpc_clnt
656 * @args: pointer to the new transport arguments
657 * @timeout: pointer to the new timeout parameters
658 *
659 * This function allows the caller to switch the RPC transport for the
660 * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
661 * server, for instance. It assumes that the caller has ensured that
662 * there are no active RPC tasks by using some form of locking.
663 *
664 * Returns zero if "clnt" is now using the new xprt. Otherwise a
665 * negative errno is returned, and "clnt" continues to use the old
666 * xprt.
667 */
668 int rpc_switch_client_transport(struct rpc_clnt *clnt,
669 struct xprt_create *args,
670 const struct rpc_timeout *timeout)
671 {
672 const struct rpc_timeout *old_timeo;
673 rpc_authflavor_t pseudoflavor;
674 struct rpc_xprt_switch *xps, *oldxps;
675 struct rpc_xprt *xprt, *old;
676 struct rpc_clnt *parent;
677 int err;
678
679 xprt = xprt_create_transport(args);
680 if (IS_ERR(xprt)) {
681 dprintk("RPC: failed to create new xprt for clnt %p\n",
682 clnt);
683 return PTR_ERR(xprt);
684 }
685
686 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
687 if (xps == NULL) {
688 xprt_put(xprt);
689 return -ENOMEM;
690 }
691
692 pseudoflavor = clnt->cl_auth->au_flavor;
693
694 old_timeo = clnt->cl_timeout;
695 old = rpc_clnt_set_transport(clnt, xprt, timeout);
696 oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
697
698 rpc_unregister_client(clnt);
699 __rpc_clnt_remove_pipedir(clnt);
700 rpc_clnt_debugfs_unregister(clnt);
701
702 /*
703 * A new transport was created. "clnt" therefore
704 * becomes the root of a new cl_parent tree. clnt's
705 * children, if it has any, still point to the old xprt.
706 */
707 parent = clnt->cl_parent;
708 clnt->cl_parent = clnt;
709
710 /*
711 * The old rpc_auth cache cannot be re-used. GSS
712 * contexts in particular are between a single
713 * client and server.
714 */
715 err = rpc_client_register(clnt, pseudoflavor, NULL);
716 if (err)
717 goto out_revert;
718
719 synchronize_rcu();
720 if (parent != clnt)
721 rpc_release_client(parent);
722 xprt_switch_put(oldxps);
723 xprt_put(old);
724 dprintk("RPC: replaced xprt for clnt %p\n", clnt);
725 return 0;
726
727 out_revert:
728 xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
729 rpc_clnt_set_transport(clnt, old, old_timeo);
730 clnt->cl_parent = parent;
731 rpc_client_register(clnt, pseudoflavor, NULL);
732 xprt_switch_put(xps);
733 xprt_put(xprt);
734 dprintk("RPC: failed to switch xprt for clnt %p\n", clnt);
735 return err;
736 }
737 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
738
739 static
740 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
741 {
742 struct rpc_xprt_switch *xps;
743
744 rcu_read_lock();
745 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
746 rcu_read_unlock();
747 if (xps == NULL)
748 return -EAGAIN;
749 xprt_iter_init_listall(xpi, xps);
750 xprt_switch_put(xps);
751 return 0;
752 }
753
754 /**
755 * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
756 * @clnt: pointer to client
757 * @fn: function to apply
758 * @data: void pointer to function data
759 *
760 * Iterates through the list of RPC transports currently attached to the
761 * client and applies the function fn(clnt, xprt, data).
762 *
763 * On error, the iteration stops, and the function returns the error value.
764 */
765 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
766 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
767 void *data)
768 {
769 struct rpc_xprt_iter xpi;
770 int ret;
771
772 ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
773 if (ret)
774 return ret;
775 for (;;) {
776 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
777
778 if (!xprt)
779 break;
780 ret = fn(clnt, xprt, data);
781 xprt_put(xprt);
782 if (ret < 0)
783 break;
784 }
785 xprt_iter_destroy(&xpi);
786 return ret;
787 }
788 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
789
790 /*
791 * Kill all tasks for the given client.
792 * XXX: kill their descendants as well?
793 */
794 void rpc_killall_tasks(struct rpc_clnt *clnt)
795 {
796 struct rpc_task *rovr;
797
798
799 if (list_empty(&clnt->cl_tasks))
800 return;
801 dprintk("RPC: killing all tasks for client %p\n", clnt);
802 /*
803 * Spin lock all_tasks to prevent changes...
804 */
805 spin_lock(&clnt->cl_lock);
806 list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
807 if (!RPC_IS_ACTIVATED(rovr))
808 continue;
809 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
810 rovr->tk_flags |= RPC_TASK_KILLED;
811 rpc_exit(rovr, -EIO);
812 if (RPC_IS_QUEUED(rovr))
813 rpc_wake_up_queued_task(rovr->tk_waitqueue,
814 rovr);
815 }
816 }
817 spin_unlock(&clnt->cl_lock);
818 }
819 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
820
821 /*
822 * Properly shut down an RPC client, terminating all outstanding
823 * requests.
824 */
825 void rpc_shutdown_client(struct rpc_clnt *clnt)
826 {
827 might_sleep();
828
829 dprintk_rcu("RPC: shutting down %s client for %s\n",
830 clnt->cl_program->name,
831 rcu_dereference(clnt->cl_xprt)->servername);
832
833 while (!list_empty(&clnt->cl_tasks)) {
834 rpc_killall_tasks(clnt);
835 wait_event_timeout(destroy_wait,
836 list_empty(&clnt->cl_tasks), 1*HZ);
837 }
838
839 rpc_release_client(clnt);
840 }
841 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
842
843 /*
844 * Free an RPC client
845 */
846 static struct rpc_clnt *
847 rpc_free_client(struct rpc_clnt *clnt)
848 {
849 struct rpc_clnt *parent = NULL;
850
851 dprintk_rcu("RPC: destroying %s client for %s\n",
852 clnt->cl_program->name,
853 rcu_dereference(clnt->cl_xprt)->servername);
854 if (clnt->cl_parent != clnt)
855 parent = clnt->cl_parent;
856 rpc_clnt_debugfs_unregister(clnt);
857 rpc_clnt_remove_pipedir(clnt);
858 rpc_unregister_client(clnt);
859 rpc_free_iostats(clnt->cl_metrics);
860 clnt->cl_metrics = NULL;
861 xprt_put(rcu_dereference_raw(clnt->cl_xprt));
862 xprt_iter_destroy(&clnt->cl_xpi);
863 rpciod_down();
864 rpc_free_clid(clnt);
865 kfree(clnt);
866 return parent;
867 }
868
869 /*
870 * Free an RPC client
871 */
872 static struct rpc_clnt *
873 rpc_free_auth(struct rpc_clnt *clnt)
874 {
875 if (clnt->cl_auth == NULL)
876 return rpc_free_client(clnt);
877
878 /*
879 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
880 * release remaining GSS contexts. This mechanism ensures
881 * that it can do so safely.
882 */
883 atomic_inc(&clnt->cl_count);
884 rpcauth_release(clnt->cl_auth);
885 clnt->cl_auth = NULL;
886 if (atomic_dec_and_test(&clnt->cl_count))
887 return rpc_free_client(clnt);
888 return NULL;
889 }
890
891 /*
892 * Release reference to the RPC client
893 */
894 void
895 rpc_release_client(struct rpc_clnt *clnt)
896 {
897 dprintk("RPC: rpc_release_client(%p)\n", clnt);
898
899 do {
900 if (list_empty(&clnt->cl_tasks))
901 wake_up(&destroy_wait);
902 if (!atomic_dec_and_test(&clnt->cl_count))
903 break;
904 clnt = rpc_free_auth(clnt);
905 } while (clnt != NULL);
906 }
907 EXPORT_SYMBOL_GPL(rpc_release_client);
908
909 /**
910 * rpc_bind_new_program - bind a new RPC program to an existing client
911 * @old: old rpc_client
912 * @program: rpc program to set
913 * @vers: rpc program version
914 *
915 * Clones the rpc client and sets up a new RPC program. This is mainly
916 * of use for enabling different RPC programs to share the same transport.
917 * The Sun NFSv2/v3 ACL protocol can do this.
918 */
919 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
920 const struct rpc_program *program,
921 u32 vers)
922 {
923 struct rpc_create_args args = {
924 .program = program,
925 .prognumber = program->number,
926 .version = vers,
927 .authflavor = old->cl_auth->au_flavor,
928 };
929 struct rpc_clnt *clnt;
930 int err;
931
932 clnt = __rpc_clone_client(&args, old);
933 if (IS_ERR(clnt))
934 goto out;
935 err = rpc_ping(clnt);
936 if (err != 0) {
937 rpc_shutdown_client(clnt);
938 clnt = ERR_PTR(err);
939 }
940 out:
941 return clnt;
942 }
943 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
944
945 void rpc_task_release_client(struct rpc_task *task)
946 {
947 struct rpc_clnt *clnt = task->tk_client;
948 struct rpc_xprt *xprt = task->tk_xprt;
949
950 if (clnt != NULL) {
951 /* Remove from client task list */
952 spin_lock(&clnt->cl_lock);
953 list_del(&task->tk_task);
954 spin_unlock(&clnt->cl_lock);
955 task->tk_client = NULL;
956
957 rpc_release_client(clnt);
958 }
959
960 if (xprt != NULL) {
961 task->tk_xprt = NULL;
962
963 xprt_put(xprt);
964 }
965 }
966
967 static
968 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
969 {
970
971 if (clnt != NULL) {
972 rpc_task_release_client(task);
973 if (task->tk_xprt == NULL)
974 task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
975 task->tk_client = clnt;
976 atomic_inc(&clnt->cl_count);
977 if (clnt->cl_softrtry)
978 task->tk_flags |= RPC_TASK_SOFT;
979 if (clnt->cl_noretranstimeo)
980 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
981 if (atomic_read(&clnt->cl_swapper))
982 task->tk_flags |= RPC_TASK_SWAPPER;
983 /* Add to the client's list of all tasks */
984 spin_lock(&clnt->cl_lock);
985 list_add_tail(&task->tk_task, &clnt->cl_tasks);
986 spin_unlock(&clnt->cl_lock);
987 }
988 }
989
990 static void
991 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
992 {
993 if (msg != NULL) {
994 task->tk_msg.rpc_proc = msg->rpc_proc;
995 task->tk_msg.rpc_argp = msg->rpc_argp;
996 task->tk_msg.rpc_resp = msg->rpc_resp;
997 if (msg->rpc_cred != NULL)
998 task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
999 }
1000 }
1001
1002 /*
1003 * Default callback for async RPC calls
1004 */
1005 static void
1006 rpc_default_callback(struct rpc_task *task, void *data)
1007 {
1008 }
1009
1010 static const struct rpc_call_ops rpc_default_ops = {
1011 .rpc_call_done = rpc_default_callback,
1012 };
1013
1014 /**
1015 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1016 * @task_setup_data: pointer to task initialisation data
1017 */
1018 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1019 {
1020 struct rpc_task *task;
1021
1022 task = rpc_new_task(task_setup_data);
1023 if (IS_ERR(task))
1024 goto out;
1025
1026 rpc_task_set_client(task, task_setup_data->rpc_client);
1027 rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1028
1029 if (task->tk_action == NULL)
1030 rpc_call_start(task);
1031
1032 atomic_inc(&task->tk_count);
1033 rpc_execute(task);
1034 out:
1035 return task;
1036 }
1037 EXPORT_SYMBOL_GPL(rpc_run_task);
1038
1039 /**
1040 * rpc_call_sync - Perform a synchronous RPC call
1041 * @clnt: pointer to RPC client
1042 * @msg: RPC call parameters
1043 * @flags: RPC call flags
1044 */
1045 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1046 {
1047 struct rpc_task *task;
1048 struct rpc_task_setup task_setup_data = {
1049 .rpc_client = clnt,
1050 .rpc_message = msg,
1051 .callback_ops = &rpc_default_ops,
1052 .flags = flags,
1053 };
1054 int status;
1055
1056 WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1057 if (flags & RPC_TASK_ASYNC) {
1058 rpc_release_calldata(task_setup_data.callback_ops,
1059 task_setup_data.callback_data);
1060 return -EINVAL;
1061 }
1062
1063 task = rpc_run_task(&task_setup_data);
1064 if (IS_ERR(task))
1065 return PTR_ERR(task);
1066 status = task->tk_status;
1067 rpc_put_task(task);
1068 return status;
1069 }
1070 EXPORT_SYMBOL_GPL(rpc_call_sync);
1071
1072 /**
1073 * rpc_call_async - Perform an asynchronous RPC call
1074 * @clnt: pointer to RPC client
1075 * @msg: RPC call parameters
1076 * @flags: RPC call flags
1077 * @tk_ops: RPC call ops
1078 * @data: user call data
1079 */
1080 int
1081 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1082 const struct rpc_call_ops *tk_ops, void *data)
1083 {
1084 struct rpc_task *task;
1085 struct rpc_task_setup task_setup_data = {
1086 .rpc_client = clnt,
1087 .rpc_message = msg,
1088 .callback_ops = tk_ops,
1089 .callback_data = data,
1090 .flags = flags|RPC_TASK_ASYNC,
1091 };
1092
1093 task = rpc_run_task(&task_setup_data);
1094 if (IS_ERR(task))
1095 return PTR_ERR(task);
1096 rpc_put_task(task);
1097 return 0;
1098 }
1099 EXPORT_SYMBOL_GPL(rpc_call_async);
1100
1101 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1102 /**
1103 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1104 * rpc_execute against it
1105 * @req: RPC request
1106 */
1107 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1108 {
1109 struct rpc_task *task;
1110 struct xdr_buf *xbufp = &req->rq_snd_buf;
1111 struct rpc_task_setup task_setup_data = {
1112 .callback_ops = &rpc_default_ops,
1113 .flags = RPC_TASK_SOFTCONN,
1114 };
1115
1116 dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1117 /*
1118 * Create an rpc_task to send the data
1119 */
1120 task = rpc_new_task(&task_setup_data);
1121 if (IS_ERR(task)) {
1122 xprt_free_bc_request(req);
1123 goto out;
1124 }
1125 task->tk_rqstp = req;
1126
1127 /*
1128 * Set up the xdr_buf length.
1129 * This also indicates that the buffer is XDR encoded already.
1130 */
1131 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1132 xbufp->tail[0].iov_len;
1133
1134 task->tk_action = call_bc_transmit;
1135 atomic_inc(&task->tk_count);
1136 WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1137 rpc_execute(task);
1138
1139 out:
1140 dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1141 return task;
1142 }
1143 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1144
1145 void
1146 rpc_call_start(struct rpc_task *task)
1147 {
1148 task->tk_action = call_start;
1149 }
1150 EXPORT_SYMBOL_GPL(rpc_call_start);
1151
1152 /**
1153 * rpc_peeraddr - extract remote peer address from clnt's xprt
1154 * @clnt: RPC client structure
1155 * @buf: target buffer
1156 * @bufsize: length of target buffer
1157 *
1158 * Returns the number of bytes that are actually in the stored address.
1159 */
1160 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1161 {
1162 size_t bytes;
1163 struct rpc_xprt *xprt;
1164
1165 rcu_read_lock();
1166 xprt = rcu_dereference(clnt->cl_xprt);
1167
1168 bytes = xprt->addrlen;
1169 if (bytes > bufsize)
1170 bytes = bufsize;
1171 memcpy(buf, &xprt->addr, bytes);
1172 rcu_read_unlock();
1173
1174 return bytes;
1175 }
1176 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1177
1178 /**
1179 * rpc_peeraddr2str - return remote peer address in printable format
1180 * @clnt: RPC client structure
1181 * @format: address format
1182 *
1183 * NB: the lifetime of the memory referenced by the returned pointer is
1184 * the same as the rpc_xprt itself. As long as the caller uses this
1185 * pointer, it must hold the RCU read lock.
1186 */
1187 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1188 enum rpc_display_format_t format)
1189 {
1190 struct rpc_xprt *xprt;
1191
1192 xprt = rcu_dereference(clnt->cl_xprt);
1193
1194 if (xprt->address_strings[format] != NULL)
1195 return xprt->address_strings[format];
1196 else
1197 return "unprintable";
1198 }
1199 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1200
1201 static const struct sockaddr_in rpc_inaddr_loopback = {
1202 .sin_family = AF_INET,
1203 .sin_addr.s_addr = htonl(INADDR_ANY),
1204 };
1205
1206 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1207 .sin6_family = AF_INET6,
1208 .sin6_addr = IN6ADDR_ANY_INIT,
1209 };
1210
1211 /*
1212 * Try a getsockname() on a connected datagram socket. Using a
1213 * connected datagram socket prevents leaving a socket in TIME_WAIT.
1214 * This conserves the ephemeral port number space.
1215 *
1216 * Returns zero and fills in "buf" if successful; otherwise, a
1217 * negative errno is returned.
1218 */
1219 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1220 struct sockaddr *buf, int buflen)
1221 {
1222 struct socket *sock;
1223 int err;
1224
1225 err = __sock_create(net, sap->sa_family,
1226 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1227 if (err < 0) {
1228 dprintk("RPC: can't create UDP socket (%d)\n", err);
1229 goto out;
1230 }
1231
1232 switch (sap->sa_family) {
1233 case AF_INET:
1234 err = kernel_bind(sock,
1235 (struct sockaddr *)&rpc_inaddr_loopback,
1236 sizeof(rpc_inaddr_loopback));
1237 break;
1238 case AF_INET6:
1239 err = kernel_bind(sock,
1240 (struct sockaddr *)&rpc_in6addr_loopback,
1241 sizeof(rpc_in6addr_loopback));
1242 break;
1243 default:
1244 err = -EAFNOSUPPORT;
1245 goto out;
1246 }
1247 if (err < 0) {
1248 dprintk("RPC: can't bind UDP socket (%d)\n", err);
1249 goto out_release;
1250 }
1251
1252 err = kernel_connect(sock, sap, salen, 0);
1253 if (err < 0) {
1254 dprintk("RPC: can't connect UDP socket (%d)\n", err);
1255 goto out_release;
1256 }
1257
1258 err = kernel_getsockname(sock, buf, &buflen);
1259 if (err < 0) {
1260 dprintk("RPC: getsockname failed (%d)\n", err);
1261 goto out_release;
1262 }
1263
1264 err = 0;
1265 if (buf->sa_family == AF_INET6) {
1266 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1267 sin6->sin6_scope_id = 0;
1268 }
1269 dprintk("RPC: %s succeeded\n", __func__);
1270
1271 out_release:
1272 sock_release(sock);
1273 out:
1274 return err;
1275 }
1276
1277 /*
1278 * Scraping a connected socket failed, so we don't have a useable
1279 * local address. Fallback: generate an address that will prevent
1280 * the server from calling us back.
1281 *
1282 * Returns zero and fills in "buf" if successful; otherwise, a
1283 * negative errno is returned.
1284 */
1285 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1286 {
1287 switch (family) {
1288 case AF_INET:
1289 if (buflen < sizeof(rpc_inaddr_loopback))
1290 return -EINVAL;
1291 memcpy(buf, &rpc_inaddr_loopback,
1292 sizeof(rpc_inaddr_loopback));
1293 break;
1294 case AF_INET6:
1295 if (buflen < sizeof(rpc_in6addr_loopback))
1296 return -EINVAL;
1297 memcpy(buf, &rpc_in6addr_loopback,
1298 sizeof(rpc_in6addr_loopback));
1299 break;
1300 default:
1301 dprintk("RPC: %s: address family not supported\n",
1302 __func__);
1303 return -EAFNOSUPPORT;
1304 }
1305 dprintk("RPC: %s: succeeded\n", __func__);
1306 return 0;
1307 }
1308
1309 /**
1310 * rpc_localaddr - discover local endpoint address for an RPC client
1311 * @clnt: RPC client structure
1312 * @buf: target buffer
1313 * @buflen: size of target buffer, in bytes
1314 *
1315 * Returns zero and fills in "buf" and "buflen" if successful;
1316 * otherwise, a negative errno is returned.
1317 *
1318 * This works even if the underlying transport is not currently connected,
1319 * or if the upper layer never previously provided a source address.
1320 *
1321 * The result of this function call is transient: multiple calls in
1322 * succession may give different results, depending on how local
1323 * networking configuration changes over time.
1324 */
1325 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1326 {
1327 struct sockaddr_storage address;
1328 struct sockaddr *sap = (struct sockaddr *)&address;
1329 struct rpc_xprt *xprt;
1330 struct net *net;
1331 size_t salen;
1332 int err;
1333
1334 rcu_read_lock();
1335 xprt = rcu_dereference(clnt->cl_xprt);
1336 salen = xprt->addrlen;
1337 memcpy(sap, &xprt->addr, salen);
1338 net = get_net(xprt->xprt_net);
1339 rcu_read_unlock();
1340
1341 rpc_set_port(sap, 0);
1342 err = rpc_sockname(net, sap, salen, buf, buflen);
1343 put_net(net);
1344 if (err != 0)
1345 /* Couldn't discover local address, return ANYADDR */
1346 return rpc_anyaddr(sap->sa_family, buf, buflen);
1347 return 0;
1348 }
1349 EXPORT_SYMBOL_GPL(rpc_localaddr);
1350
1351 void
1352 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1353 {
1354 struct rpc_xprt *xprt;
1355
1356 rcu_read_lock();
1357 xprt = rcu_dereference(clnt->cl_xprt);
1358 if (xprt->ops->set_buffer_size)
1359 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1360 rcu_read_unlock();
1361 }
1362 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1363
1364 /**
1365 * rpc_protocol - Get transport protocol number for an RPC client
1366 * @clnt: RPC client to query
1367 *
1368 */
1369 int rpc_protocol(struct rpc_clnt *clnt)
1370 {
1371 int protocol;
1372
1373 rcu_read_lock();
1374 protocol = rcu_dereference(clnt->cl_xprt)->prot;
1375 rcu_read_unlock();
1376 return protocol;
1377 }
1378 EXPORT_SYMBOL_GPL(rpc_protocol);
1379
1380 /**
1381 * rpc_net_ns - Get the network namespace for this RPC client
1382 * @clnt: RPC client to query
1383 *
1384 */
1385 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1386 {
1387 struct net *ret;
1388
1389 rcu_read_lock();
1390 ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1391 rcu_read_unlock();
1392 return ret;
1393 }
1394 EXPORT_SYMBOL_GPL(rpc_net_ns);
1395
1396 /**
1397 * rpc_max_payload - Get maximum payload size for a transport, in bytes
1398 * @clnt: RPC client to query
1399 *
1400 * For stream transports, this is one RPC record fragment (see RFC
1401 * 1831), as we don't support multi-record requests yet. For datagram
1402 * transports, this is the size of an IP packet minus the IP, UDP, and
1403 * RPC header sizes.
1404 */
1405 size_t rpc_max_payload(struct rpc_clnt *clnt)
1406 {
1407 size_t ret;
1408
1409 rcu_read_lock();
1410 ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1411 rcu_read_unlock();
1412 return ret;
1413 }
1414 EXPORT_SYMBOL_GPL(rpc_max_payload);
1415
1416 /**
1417 * rpc_get_timeout - Get timeout for transport in units of HZ
1418 * @clnt: RPC client to query
1419 */
1420 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1421 {
1422 unsigned long ret;
1423
1424 rcu_read_lock();
1425 ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1426 rcu_read_unlock();
1427 return ret;
1428 }
1429 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1430
1431 /**
1432 * rpc_force_rebind - force transport to check that remote port is unchanged
1433 * @clnt: client to rebind
1434 *
1435 */
1436 void rpc_force_rebind(struct rpc_clnt *clnt)
1437 {
1438 if (clnt->cl_autobind) {
1439 rcu_read_lock();
1440 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1441 rcu_read_unlock();
1442 }
1443 }
1444 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1445
1446 /*
1447 * Restart an (async) RPC call from the call_prepare state.
1448 * Usually called from within the exit handler.
1449 */
1450 int
1451 rpc_restart_call_prepare(struct rpc_task *task)
1452 {
1453 if (RPC_ASSASSINATED(task))
1454 return 0;
1455 task->tk_action = call_start;
1456 task->tk_status = 0;
1457 if (task->tk_ops->rpc_call_prepare != NULL)
1458 task->tk_action = rpc_prepare_task;
1459 return 1;
1460 }
1461 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1462
1463 /*
1464 * Restart an (async) RPC call. Usually called from within the
1465 * exit handler.
1466 */
1467 int
1468 rpc_restart_call(struct rpc_task *task)
1469 {
1470 if (RPC_ASSASSINATED(task))
1471 return 0;
1472 task->tk_action = call_start;
1473 task->tk_status = 0;
1474 return 1;
1475 }
1476 EXPORT_SYMBOL_GPL(rpc_restart_call);
1477
1478 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1479 const char
1480 *rpc_proc_name(const struct rpc_task *task)
1481 {
1482 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1483
1484 if (proc) {
1485 if (proc->p_name)
1486 return proc->p_name;
1487 else
1488 return "NULL";
1489 } else
1490 return "no proc";
1491 }
1492 #endif
1493
1494 /*
1495 * 0. Initial state
1496 *
1497 * Other FSM states can be visited zero or more times, but
1498 * this state is visited exactly once for each RPC.
1499 */
1500 static void
1501 call_start(struct rpc_task *task)
1502 {
1503 struct rpc_clnt *clnt = task->tk_client;
1504
1505 dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1506 clnt->cl_program->name, clnt->cl_vers,
1507 rpc_proc_name(task),
1508 (RPC_IS_ASYNC(task) ? "async" : "sync"));
1509
1510 /* Increment call count */
1511 task->tk_msg.rpc_proc->p_count++;
1512 clnt->cl_stats->rpccnt++;
1513 task->tk_action = call_reserve;
1514 }
1515
1516 /*
1517 * 1. Reserve an RPC call slot
1518 */
1519 static void
1520 call_reserve(struct rpc_task *task)
1521 {
1522 dprint_status(task);
1523
1524 task->tk_status = 0;
1525 task->tk_action = call_reserveresult;
1526 xprt_reserve(task);
1527 }
1528
1529 static void call_retry_reserve(struct rpc_task *task);
1530
1531 /*
1532 * 1b. Grok the result of xprt_reserve()
1533 */
1534 static void
1535 call_reserveresult(struct rpc_task *task)
1536 {
1537 int status = task->tk_status;
1538
1539 dprint_status(task);
1540
1541 /*
1542 * After a call to xprt_reserve(), we must have either
1543 * a request slot or else an error status.
1544 */
1545 task->tk_status = 0;
1546 if (status >= 0) {
1547 if (task->tk_rqstp) {
1548 task->tk_action = call_refresh;
1549 return;
1550 }
1551
1552 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1553 __func__, status);
1554 rpc_exit(task, -EIO);
1555 return;
1556 }
1557
1558 /*
1559 * Even though there was an error, we may have acquired
1560 * a request slot somehow. Make sure not to leak it.
1561 */
1562 if (task->tk_rqstp) {
1563 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1564 __func__, status);
1565 xprt_release(task);
1566 }
1567
1568 switch (status) {
1569 case -ENOMEM:
1570 rpc_delay(task, HZ >> 2);
1571 case -EAGAIN: /* woken up; retry */
1572 task->tk_action = call_retry_reserve;
1573 return;
1574 case -EIO: /* probably a shutdown */
1575 break;
1576 default:
1577 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1578 __func__, status);
1579 break;
1580 }
1581 rpc_exit(task, status);
1582 }
1583
1584 /*
1585 * 1c. Retry reserving an RPC call slot
1586 */
1587 static void
1588 call_retry_reserve(struct rpc_task *task)
1589 {
1590 dprint_status(task);
1591
1592 task->tk_status = 0;
1593 task->tk_action = call_reserveresult;
1594 xprt_retry_reserve(task);
1595 }
1596
1597 /*
1598 * 2. Bind and/or refresh the credentials
1599 */
1600 static void
1601 call_refresh(struct rpc_task *task)
1602 {
1603 dprint_status(task);
1604
1605 task->tk_action = call_refreshresult;
1606 task->tk_status = 0;
1607 task->tk_client->cl_stats->rpcauthrefresh++;
1608 rpcauth_refreshcred(task);
1609 }
1610
1611 /*
1612 * 2a. Process the results of a credential refresh
1613 */
1614 static void
1615 call_refreshresult(struct rpc_task *task)
1616 {
1617 int status = task->tk_status;
1618
1619 dprint_status(task);
1620
1621 task->tk_status = 0;
1622 task->tk_action = call_refresh;
1623 switch (status) {
1624 case 0:
1625 if (rpcauth_uptodatecred(task)) {
1626 task->tk_action = call_allocate;
1627 return;
1628 }
1629 /* Use rate-limiting and a max number of retries if refresh
1630 * had status 0 but failed to update the cred.
1631 */
1632 case -ETIMEDOUT:
1633 rpc_delay(task, 3*HZ);
1634 case -EAGAIN:
1635 status = -EACCES;
1636 case -EKEYEXPIRED:
1637 if (!task->tk_cred_retry)
1638 break;
1639 task->tk_cred_retry--;
1640 dprintk("RPC: %5u %s: retry refresh creds\n",
1641 task->tk_pid, __func__);
1642 return;
1643 }
1644 dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1645 task->tk_pid, __func__, status);
1646 rpc_exit(task, status);
1647 }
1648
1649 /*
1650 * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc.
1651 * (Note: buffer memory is freed in xprt_release).
1652 */
1653 static void
1654 call_allocate(struct rpc_task *task)
1655 {
1656 unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1657 struct rpc_rqst *req = task->tk_rqstp;
1658 struct rpc_xprt *xprt = req->rq_xprt;
1659 struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1660
1661 dprint_status(task);
1662
1663 task->tk_status = 0;
1664 task->tk_action = call_bind;
1665
1666 if (req->rq_buffer)
1667 return;
1668
1669 if (proc->p_proc != 0) {
1670 BUG_ON(proc->p_arglen == 0);
1671 if (proc->p_decode != NULL)
1672 BUG_ON(proc->p_replen == 0);
1673 }
1674
1675 /*
1676 * Calculate the size (in quads) of the RPC call
1677 * and reply headers, and convert both values
1678 * to byte sizes.
1679 */
1680 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1681 req->rq_callsize <<= 2;
1682 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1683 req->rq_rcvsize <<= 2;
1684
1685 req->rq_buffer = xprt->ops->buf_alloc(task,
1686 req->rq_callsize + req->rq_rcvsize);
1687 if (req->rq_buffer != NULL)
1688 return;
1689 xprt_inject_disconnect(xprt);
1690
1691 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1692
1693 if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1694 task->tk_action = call_allocate;
1695 rpc_delay(task, HZ>>4);
1696 return;
1697 }
1698
1699 rpc_exit(task, -ERESTARTSYS);
1700 }
1701
1702 static inline int
1703 rpc_task_need_encode(struct rpc_task *task)
1704 {
1705 return task->tk_rqstp->rq_snd_buf.len == 0;
1706 }
1707
1708 static inline void
1709 rpc_task_force_reencode(struct rpc_task *task)
1710 {
1711 task->tk_rqstp->rq_snd_buf.len = 0;
1712 task->tk_rqstp->rq_bytes_sent = 0;
1713 }
1714
1715 static inline void
1716 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1717 {
1718 buf->head[0].iov_base = start;
1719 buf->head[0].iov_len = len;
1720 buf->tail[0].iov_len = 0;
1721 buf->page_len = 0;
1722 buf->flags = 0;
1723 buf->len = 0;
1724 buf->buflen = len;
1725 }
1726
1727 /*
1728 * 3. Encode arguments of an RPC call
1729 */
1730 static void
1731 rpc_xdr_encode(struct rpc_task *task)
1732 {
1733 struct rpc_rqst *req = task->tk_rqstp;
1734 kxdreproc_t encode;
1735 __be32 *p;
1736
1737 dprint_status(task);
1738
1739 rpc_xdr_buf_init(&req->rq_snd_buf,
1740 req->rq_buffer,
1741 req->rq_callsize);
1742 rpc_xdr_buf_init(&req->rq_rcv_buf,
1743 (char *)req->rq_buffer + req->rq_callsize,
1744 req->rq_rcvsize);
1745
1746 p = rpc_encode_header(task);
1747 if (p == NULL) {
1748 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1749 rpc_exit(task, -EIO);
1750 return;
1751 }
1752
1753 encode = task->tk_msg.rpc_proc->p_encode;
1754 if (encode == NULL)
1755 return;
1756
1757 task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1758 task->tk_msg.rpc_argp);
1759 }
1760
1761 /*
1762 * 4. Get the server port number if not yet set
1763 */
1764 static void
1765 call_bind(struct rpc_task *task)
1766 {
1767 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1768
1769 dprint_status(task);
1770
1771 task->tk_action = call_connect;
1772 if (!xprt_bound(xprt)) {
1773 task->tk_action = call_bind_status;
1774 task->tk_timeout = xprt->bind_timeout;
1775 xprt->ops->rpcbind(task);
1776 }
1777 }
1778
1779 /*
1780 * 4a. Sort out bind result
1781 */
1782 static void
1783 call_bind_status(struct rpc_task *task)
1784 {
1785 int status = -EIO;
1786
1787 if (task->tk_status >= 0) {
1788 dprint_status(task);
1789 task->tk_status = 0;
1790 task->tk_action = call_connect;
1791 return;
1792 }
1793
1794 trace_rpc_bind_status(task);
1795 switch (task->tk_status) {
1796 case -ENOMEM:
1797 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1798 rpc_delay(task, HZ >> 2);
1799 goto retry_timeout;
1800 case -EACCES:
1801 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1802 "unavailable\n", task->tk_pid);
1803 /* fail immediately if this is an RPC ping */
1804 if (task->tk_msg.rpc_proc->p_proc == 0) {
1805 status = -EOPNOTSUPP;
1806 break;
1807 }
1808 if (task->tk_rebind_retry == 0)
1809 break;
1810 task->tk_rebind_retry--;
1811 rpc_delay(task, 3*HZ);
1812 goto retry_timeout;
1813 case -ETIMEDOUT:
1814 dprintk("RPC: %5u rpcbind request timed out\n",
1815 task->tk_pid);
1816 goto retry_timeout;
1817 case -EPFNOSUPPORT:
1818 /* server doesn't support any rpcbind version we know of */
1819 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1820 task->tk_pid);
1821 break;
1822 case -EPROTONOSUPPORT:
1823 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1824 task->tk_pid);
1825 goto retry_timeout;
1826 case -ECONNREFUSED: /* connection problems */
1827 case -ECONNRESET:
1828 case -ECONNABORTED:
1829 case -ENOTCONN:
1830 case -EHOSTDOWN:
1831 case -EHOSTUNREACH:
1832 case -ENETUNREACH:
1833 case -ENOBUFS:
1834 case -EPIPE:
1835 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1836 task->tk_pid, task->tk_status);
1837 if (!RPC_IS_SOFTCONN(task)) {
1838 rpc_delay(task, 5*HZ);
1839 goto retry_timeout;
1840 }
1841 status = task->tk_status;
1842 break;
1843 default:
1844 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1845 task->tk_pid, -task->tk_status);
1846 }
1847
1848 rpc_exit(task, status);
1849 return;
1850
1851 retry_timeout:
1852 task->tk_status = 0;
1853 task->tk_action = call_timeout;
1854 }
1855
1856 /*
1857 * 4b. Connect to the RPC server
1858 */
1859 static void
1860 call_connect(struct rpc_task *task)
1861 {
1862 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1863
1864 dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1865 task->tk_pid, xprt,
1866 (xprt_connected(xprt) ? "is" : "is not"));
1867
1868 task->tk_action = call_transmit;
1869 if (!xprt_connected(xprt)) {
1870 task->tk_action = call_connect_status;
1871 if (task->tk_status < 0)
1872 return;
1873 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1874 rpc_exit(task, -ENOTCONN);
1875 return;
1876 }
1877 xprt_connect(task);
1878 }
1879 }
1880
1881 /*
1882 * 4c. Sort out connect result
1883 */
1884 static void
1885 call_connect_status(struct rpc_task *task)
1886 {
1887 struct rpc_clnt *clnt = task->tk_client;
1888 int status = task->tk_status;
1889
1890 dprint_status(task);
1891
1892 trace_rpc_connect_status(task, status);
1893 task->tk_status = 0;
1894 switch (status) {
1895 case -ECONNREFUSED:
1896 case -ECONNRESET:
1897 case -ECONNABORTED:
1898 case -ENETUNREACH:
1899 case -EHOSTUNREACH:
1900 case -EADDRINUSE:
1901 case -ENOBUFS:
1902 case -EPIPE:
1903 if (RPC_IS_SOFTCONN(task))
1904 break;
1905 /* retry with existing socket, after a delay */
1906 rpc_delay(task, 3*HZ);
1907 case -EAGAIN:
1908 /* Check for timeouts before looping back to call_bind */
1909 case -ETIMEDOUT:
1910 task->tk_action = call_timeout;
1911 return;
1912 case 0:
1913 clnt->cl_stats->netreconn++;
1914 task->tk_action = call_transmit;
1915 return;
1916 }
1917 rpc_exit(task, status);
1918 }
1919
1920 /*
1921 * 5. Transmit the RPC request, and wait for reply
1922 */
1923 static void
1924 call_transmit(struct rpc_task *task)
1925 {
1926 int is_retrans = RPC_WAS_SENT(task);
1927
1928 dprint_status(task);
1929
1930 task->tk_action = call_status;
1931 if (task->tk_status < 0)
1932 return;
1933 if (!xprt_prepare_transmit(task))
1934 return;
1935 task->tk_action = call_transmit_status;
1936 /* Encode here so that rpcsec_gss can use correct sequence number. */
1937 if (rpc_task_need_encode(task)) {
1938 rpc_xdr_encode(task);
1939 /* Did the encode result in an error condition? */
1940 if (task->tk_status != 0) {
1941 /* Was the error nonfatal? */
1942 if (task->tk_status == -EAGAIN)
1943 rpc_delay(task, HZ >> 4);
1944 else
1945 rpc_exit(task, task->tk_status);
1946 return;
1947 }
1948 }
1949 xprt_transmit(task);
1950 if (task->tk_status < 0)
1951 return;
1952 if (is_retrans)
1953 task->tk_client->cl_stats->rpcretrans++;
1954 /*
1955 * On success, ensure that we call xprt_end_transmit() before sleeping
1956 * in order to allow access to the socket to other RPC requests.
1957 */
1958 call_transmit_status(task);
1959 if (rpc_reply_expected(task))
1960 return;
1961 task->tk_action = rpc_exit_task;
1962 rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1963 }
1964
1965 /*
1966 * 5a. Handle cleanup after a transmission
1967 */
1968 static void
1969 call_transmit_status(struct rpc_task *task)
1970 {
1971 task->tk_action = call_status;
1972
1973 /*
1974 * Common case: success. Force the compiler to put this
1975 * test first.
1976 */
1977 if (task->tk_status == 0) {
1978 xprt_end_transmit(task);
1979 rpc_task_force_reencode(task);
1980 return;
1981 }
1982
1983 switch (task->tk_status) {
1984 case -EAGAIN:
1985 case -ENOBUFS:
1986 break;
1987 default:
1988 dprint_status(task);
1989 xprt_end_transmit(task);
1990 rpc_task_force_reencode(task);
1991 break;
1992 /*
1993 * Special cases: if we've been waiting on the
1994 * socket's write_space() callback, or if the
1995 * socket just returned a connection error,
1996 * then hold onto the transport lock.
1997 */
1998 case -ECONNREFUSED:
1999 case -EHOSTDOWN:
2000 case -EHOSTUNREACH:
2001 case -ENETUNREACH:
2002 case -EPERM:
2003 if (RPC_IS_SOFTCONN(task)) {
2004 xprt_end_transmit(task);
2005 rpc_exit(task, task->tk_status);
2006 break;
2007 }
2008 case -ECONNRESET:
2009 case -ECONNABORTED:
2010 case -EADDRINUSE:
2011 case -ENOTCONN:
2012 case -EPIPE:
2013 rpc_task_force_reencode(task);
2014 }
2015 }
2016
2017 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2018 /*
2019 * 5b. Send the backchannel RPC reply. On error, drop the reply. In
2020 * addition, disconnect on connectivity errors.
2021 */
2022 static void
2023 call_bc_transmit(struct rpc_task *task)
2024 {
2025 struct rpc_rqst *req = task->tk_rqstp;
2026
2027 if (!xprt_prepare_transmit(task))
2028 goto out_retry;
2029
2030 if (task->tk_status < 0) {
2031 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2032 "error: %d\n", task->tk_status);
2033 goto out_done;
2034 }
2035 if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2036 req->rq_bytes_sent = 0;
2037
2038 xprt_transmit(task);
2039
2040 if (task->tk_status == -EAGAIN)
2041 goto out_nospace;
2042
2043 xprt_end_transmit(task);
2044 dprint_status(task);
2045 switch (task->tk_status) {
2046 case 0:
2047 /* Success */
2048 case -EHOSTDOWN:
2049 case -EHOSTUNREACH:
2050 case -ENETUNREACH:
2051 case -ECONNRESET:
2052 case -ECONNREFUSED:
2053 case -EADDRINUSE:
2054 case -ENOTCONN:
2055 case -EPIPE:
2056 break;
2057 case -ETIMEDOUT:
2058 /*
2059 * Problem reaching the server. Disconnect and let the
2060 * forechannel reestablish the connection. The server will
2061 * have to retransmit the backchannel request and we'll
2062 * reprocess it. Since these ops are idempotent, there's no
2063 * need to cache our reply at this time.
2064 */
2065 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2066 "error: %d\n", task->tk_status);
2067 xprt_conditional_disconnect(req->rq_xprt,
2068 req->rq_connect_cookie);
2069 break;
2070 default:
2071 /*
2072 * We were unable to reply and will have to drop the
2073 * request. The server should reconnect and retransmit.
2074 */
2075 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2076 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2077 "error: %d\n", task->tk_status);
2078 break;
2079 }
2080 rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2081 out_done:
2082 task->tk_action = rpc_exit_task;
2083 return;
2084 out_nospace:
2085 req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2086 out_retry:
2087 task->tk_status = 0;
2088 }
2089 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2090
2091 /*
2092 * 6. Sort out the RPC call status
2093 */
2094 static void
2095 call_status(struct rpc_task *task)
2096 {
2097 struct rpc_clnt *clnt = task->tk_client;
2098 struct rpc_rqst *req = task->tk_rqstp;
2099 int status;
2100
2101 if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2102 task->tk_status = req->rq_reply_bytes_recvd;
2103
2104 dprint_status(task);
2105
2106 status = task->tk_status;
2107 if (status >= 0) {
2108 task->tk_action = call_decode;
2109 return;
2110 }
2111
2112 trace_rpc_call_status(task);
2113 task->tk_status = 0;
2114 switch(status) {
2115 case -EHOSTDOWN:
2116 case -EHOSTUNREACH:
2117 case -ENETUNREACH:
2118 case -EPERM:
2119 if (RPC_IS_SOFTCONN(task)) {
2120 rpc_exit(task, status);
2121 break;
2122 }
2123 /*
2124 * Delay any retries for 3 seconds, then handle as if it
2125 * were a timeout.
2126 */
2127 rpc_delay(task, 3*HZ);
2128 case -ETIMEDOUT:
2129 task->tk_action = call_timeout;
2130 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
2131 && task->tk_client->cl_discrtry)
2132 xprt_conditional_disconnect(req->rq_xprt,
2133 req->rq_connect_cookie);
2134 break;
2135 case -ECONNREFUSED:
2136 case -ECONNRESET:
2137 case -ECONNABORTED:
2138 rpc_force_rebind(clnt);
2139 case -EADDRINUSE:
2140 rpc_delay(task, 3*HZ);
2141 case -EPIPE:
2142 case -ENOTCONN:
2143 task->tk_action = call_bind;
2144 break;
2145 case -ENOBUFS:
2146 rpc_delay(task, HZ>>2);
2147 case -EAGAIN:
2148 task->tk_action = call_transmit;
2149 break;
2150 case -EIO:
2151 /* shutdown or soft timeout */
2152 rpc_exit(task, status);
2153 break;
2154 default:
2155 if (clnt->cl_chatty)
2156 printk("%s: RPC call returned error %d\n",
2157 clnt->cl_program->name, -status);
2158 rpc_exit(task, status);
2159 }
2160 }
2161
2162 /*
2163 * 6a. Handle RPC timeout
2164 * We do not release the request slot, so we keep using the
2165 * same XID for all retransmits.
2166 */
2167 static void
2168 call_timeout(struct rpc_task *task)
2169 {
2170 struct rpc_clnt *clnt = task->tk_client;
2171
2172 if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2173 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2174 goto retry;
2175 }
2176
2177 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2178 task->tk_timeouts++;
2179
2180 if (RPC_IS_SOFTCONN(task)) {
2181 rpc_exit(task, -ETIMEDOUT);
2182 return;
2183 }
2184 if (RPC_IS_SOFT(task)) {
2185 if (clnt->cl_chatty) {
2186 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2187 clnt->cl_program->name,
2188 task->tk_xprt->servername);
2189 }
2190 if (task->tk_flags & RPC_TASK_TIMEOUT)
2191 rpc_exit(task, -ETIMEDOUT);
2192 else
2193 rpc_exit(task, -EIO);
2194 return;
2195 }
2196
2197 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2198 task->tk_flags |= RPC_CALL_MAJORSEEN;
2199 if (clnt->cl_chatty) {
2200 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2201 clnt->cl_program->name,
2202 task->tk_xprt->servername);
2203 }
2204 }
2205 rpc_force_rebind(clnt);
2206 /*
2207 * Did our request time out due to an RPCSEC_GSS out-of-sequence
2208 * event? RFC2203 requires the server to drop all such requests.
2209 */
2210 rpcauth_invalcred(task);
2211
2212 retry:
2213 task->tk_action = call_bind;
2214 task->tk_status = 0;
2215 }
2216
2217 /*
2218 * 7. Decode the RPC reply
2219 */
2220 static void
2221 call_decode(struct rpc_task *task)
2222 {
2223 struct rpc_clnt *clnt = task->tk_client;
2224 struct rpc_rqst *req = task->tk_rqstp;
2225 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
2226 __be32 *p;
2227
2228 dprint_status(task);
2229
2230 if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2231 if (clnt->cl_chatty) {
2232 printk(KERN_NOTICE "%s: server %s OK\n",
2233 clnt->cl_program->name,
2234 task->tk_xprt->servername);
2235 }
2236 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2237 }
2238
2239 /*
2240 * Ensure that we see all writes made by xprt_complete_rqst()
2241 * before it changed req->rq_reply_bytes_recvd.
2242 */
2243 smp_rmb();
2244 req->rq_rcv_buf.len = req->rq_private_buf.len;
2245
2246 /* Check that the softirq receive buffer is valid */
2247 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2248 sizeof(req->rq_rcv_buf)) != 0);
2249
2250 if (req->rq_rcv_buf.len < 12) {
2251 if (!RPC_IS_SOFT(task)) {
2252 task->tk_action = call_bind;
2253 goto out_retry;
2254 }
2255 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
2256 clnt->cl_program->name, task->tk_status);
2257 task->tk_action = call_timeout;
2258 goto out_retry;
2259 }
2260
2261 p = rpc_verify_header(task);
2262 if (IS_ERR(p)) {
2263 if (p == ERR_PTR(-EAGAIN))
2264 goto out_retry;
2265 return;
2266 }
2267
2268 task->tk_action = rpc_exit_task;
2269
2270 if (decode) {
2271 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2272 task->tk_msg.rpc_resp);
2273 }
2274 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2275 task->tk_status);
2276 return;
2277 out_retry:
2278 task->tk_status = 0;
2279 /* Note: rpc_verify_header() may have freed the RPC slot */
2280 if (task->tk_rqstp == req) {
2281 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2282 if (task->tk_client->cl_discrtry)
2283 xprt_conditional_disconnect(req->rq_xprt,
2284 req->rq_connect_cookie);
2285 }
2286 }
2287
2288 static __be32 *
2289 rpc_encode_header(struct rpc_task *task)
2290 {
2291 struct rpc_clnt *clnt = task->tk_client;
2292 struct rpc_rqst *req = task->tk_rqstp;
2293 __be32 *p = req->rq_svec[0].iov_base;
2294
2295 /* FIXME: check buffer size? */
2296
2297 p = xprt_skip_transport_header(req->rq_xprt, p);
2298 *p++ = req->rq_xid; /* XID */
2299 *p++ = htonl(RPC_CALL); /* CALL */
2300 *p++ = htonl(RPC_VERSION); /* RPC version */
2301 *p++ = htonl(clnt->cl_prog); /* program number */
2302 *p++ = htonl(clnt->cl_vers); /* program version */
2303 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
2304 p = rpcauth_marshcred(task, p);
2305 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2306 return p;
2307 }
2308
2309 static __be32 *
2310 rpc_verify_header(struct rpc_task *task)
2311 {
2312 struct rpc_clnt *clnt = task->tk_client;
2313 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2314 int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2315 __be32 *p = iov->iov_base;
2316 u32 n;
2317 int error = -EACCES;
2318
2319 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2320 /* RFC-1014 says that the representation of XDR data must be a
2321 * multiple of four bytes
2322 * - if it isn't pointer subtraction in the NFS client may give
2323 * undefined results
2324 */
2325 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2326 " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2327 task->tk_rqstp->rq_rcv_buf.len);
2328 error = -EIO;
2329 goto out_err;
2330 }
2331 if ((len -= 3) < 0)
2332 goto out_overflow;
2333
2334 p += 1; /* skip XID */
2335 if ((n = ntohl(*p++)) != RPC_REPLY) {
2336 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2337 task->tk_pid, __func__, n);
2338 error = -EIO;
2339 goto out_garbage;
2340 }
2341
2342 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2343 if (--len < 0)
2344 goto out_overflow;
2345 switch ((n = ntohl(*p++))) {
2346 case RPC_AUTH_ERROR:
2347 break;
2348 case RPC_MISMATCH:
2349 dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2350 task->tk_pid, __func__);
2351 error = -EPROTONOSUPPORT;
2352 goto out_err;
2353 default:
2354 dprintk("RPC: %5u %s: RPC call rejected, "
2355 "unknown error: %x\n",
2356 task->tk_pid, __func__, n);
2357 error = -EIO;
2358 goto out_err;
2359 }
2360 if (--len < 0)
2361 goto out_overflow;
2362 switch ((n = ntohl(*p++))) {
2363 case RPC_AUTH_REJECTEDCRED:
2364 case RPC_AUTH_REJECTEDVERF:
2365 case RPCSEC_GSS_CREDPROBLEM:
2366 case RPCSEC_GSS_CTXPROBLEM:
2367 if (!task->tk_cred_retry)
2368 break;
2369 task->tk_cred_retry--;
2370 dprintk("RPC: %5u %s: retry stale creds\n",
2371 task->tk_pid, __func__);
2372 rpcauth_invalcred(task);
2373 /* Ensure we obtain a new XID! */
2374 xprt_release(task);
2375 task->tk_action = call_reserve;
2376 goto out_retry;
2377 case RPC_AUTH_BADCRED:
2378 case RPC_AUTH_BADVERF:
2379 /* possibly garbled cred/verf? */
2380 if (!task->tk_garb_retry)
2381 break;
2382 task->tk_garb_retry--;
2383 dprintk("RPC: %5u %s: retry garbled creds\n",
2384 task->tk_pid, __func__);
2385 task->tk_action = call_bind;
2386 goto out_retry;
2387 case RPC_AUTH_TOOWEAK:
2388 printk(KERN_NOTICE "RPC: server %s requires stronger "
2389 "authentication.\n",
2390 task->tk_xprt->servername);
2391 break;
2392 default:
2393 dprintk("RPC: %5u %s: unknown auth error: %x\n",
2394 task->tk_pid, __func__, n);
2395 error = -EIO;
2396 }
2397 dprintk("RPC: %5u %s: call rejected %d\n",
2398 task->tk_pid, __func__, n);
2399 goto out_err;
2400 }
2401 p = rpcauth_checkverf(task, p);
2402 if (IS_ERR(p)) {
2403 error = PTR_ERR(p);
2404 dprintk("RPC: %5u %s: auth check failed with %d\n",
2405 task->tk_pid, __func__, error);
2406 goto out_garbage; /* bad verifier, retry */
2407 }
2408 len = p - (__be32 *)iov->iov_base - 1;
2409 if (len < 0)
2410 goto out_overflow;
2411 switch ((n = ntohl(*p++))) {
2412 case RPC_SUCCESS:
2413 return p;
2414 case RPC_PROG_UNAVAIL:
2415 dprintk("RPC: %5u %s: program %u is unsupported "
2416 "by server %s\n", task->tk_pid, __func__,
2417 (unsigned int)clnt->cl_prog,
2418 task->tk_xprt->servername);
2419 error = -EPFNOSUPPORT;
2420 goto out_err;
2421 case RPC_PROG_MISMATCH:
2422 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2423 "by server %s\n", task->tk_pid, __func__,
2424 (unsigned int)clnt->cl_prog,
2425 (unsigned int)clnt->cl_vers,
2426 task->tk_xprt->servername);
2427 error = -EPROTONOSUPPORT;
2428 goto out_err;
2429 case RPC_PROC_UNAVAIL:
2430 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2431 "version %u on server %s\n",
2432 task->tk_pid, __func__,
2433 rpc_proc_name(task),
2434 clnt->cl_prog, clnt->cl_vers,
2435 task->tk_xprt->servername);
2436 error = -EOPNOTSUPP;
2437 goto out_err;
2438 case RPC_GARBAGE_ARGS:
2439 dprintk("RPC: %5u %s: server saw garbage\n",
2440 task->tk_pid, __func__);
2441 break; /* retry */
2442 default:
2443 dprintk("RPC: %5u %s: server accept status: %x\n",
2444 task->tk_pid, __func__, n);
2445 /* Also retry */
2446 }
2447
2448 out_garbage:
2449 clnt->cl_stats->rpcgarbage++;
2450 if (task->tk_garb_retry) {
2451 task->tk_garb_retry--;
2452 dprintk("RPC: %5u %s: retrying\n",
2453 task->tk_pid, __func__);
2454 task->tk_action = call_bind;
2455 out_retry:
2456 return ERR_PTR(-EAGAIN);
2457 }
2458 out_err:
2459 rpc_exit(task, error);
2460 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2461 __func__, error);
2462 return ERR_PTR(error);
2463 out_overflow:
2464 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2465 __func__);
2466 goto out_garbage;
2467 }
2468
2469 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2470 {
2471 }
2472
2473 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2474 {
2475 return 0;
2476 }
2477
2478 static struct rpc_procinfo rpcproc_null = {
2479 .p_encode = rpcproc_encode_null,
2480 .p_decode = rpcproc_decode_null,
2481 };
2482
2483 static int rpc_ping(struct rpc_clnt *clnt)
2484 {
2485 struct rpc_message msg = {
2486 .rpc_proc = &rpcproc_null,
2487 };
2488 int err;
2489 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2490 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2491 put_rpccred(msg.rpc_cred);
2492 return err;
2493 }
2494
2495 static
2496 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2497 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2498 const struct rpc_call_ops *ops, void *data)
2499 {
2500 struct rpc_message msg = {
2501 .rpc_proc = &rpcproc_null,
2502 .rpc_cred = cred,
2503 };
2504 struct rpc_task_setup task_setup_data = {
2505 .rpc_client = clnt,
2506 .rpc_xprt = xprt,
2507 .rpc_message = &msg,
2508 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2509 .callback_data = data,
2510 .flags = flags,
2511 };
2512
2513 return rpc_run_task(&task_setup_data);
2514 }
2515
2516 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2517 {
2518 return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2519 }
2520 EXPORT_SYMBOL_GPL(rpc_call_null);
2521
2522 struct rpc_cb_add_xprt_calldata {
2523 struct rpc_xprt_switch *xps;
2524 struct rpc_xprt *xprt;
2525 };
2526
2527 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2528 {
2529 struct rpc_cb_add_xprt_calldata *data = calldata;
2530
2531 if (task->tk_status == 0)
2532 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2533 }
2534
2535 static void rpc_cb_add_xprt_release(void *calldata)
2536 {
2537 struct rpc_cb_add_xprt_calldata *data = calldata;
2538
2539 xprt_put(data->xprt);
2540 xprt_switch_put(data->xps);
2541 kfree(data);
2542 }
2543
2544 const static struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2545 .rpc_call_done = rpc_cb_add_xprt_done,
2546 .rpc_release = rpc_cb_add_xprt_release,
2547 };
2548
2549 /**
2550 * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2551 * @clnt: pointer to struct rpc_clnt
2552 * @xps: pointer to struct rpc_xprt_switch,
2553 * @xprt: pointer struct rpc_xprt
2554 * @dummy: unused
2555 */
2556 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2557 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2558 void *dummy)
2559 {
2560 struct rpc_cb_add_xprt_calldata *data;
2561 struct rpc_cred *cred;
2562 struct rpc_task *task;
2563
2564 data = kmalloc(sizeof(*data), GFP_NOFS);
2565 if (!data)
2566 return -ENOMEM;
2567 data->xps = xprt_switch_get(xps);
2568 data->xprt = xprt_get(xprt);
2569
2570 cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2571 task = rpc_call_null_helper(clnt, xprt, cred,
2572 RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2573 &rpc_cb_add_xprt_call_ops, data);
2574 put_rpccred(cred);
2575 if (IS_ERR(task))
2576 return PTR_ERR(task);
2577 rpc_put_task(task);
2578 return 1;
2579 }
2580 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2581
2582 /**
2583 * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2584 * @clnt: pointer to struct rpc_clnt
2585 * @xprtargs: pointer to struct xprt_create
2586 * @setup: callback to test and/or set up the connection
2587 * @data: pointer to setup function data
2588 *
2589 * Creates a new transport using the parameters set in args and
2590 * adds it to clnt.
2591 * If ping is set, then test that connectivity succeeds before
2592 * adding the new transport.
2593 *
2594 */
2595 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2596 struct xprt_create *xprtargs,
2597 int (*setup)(struct rpc_clnt *,
2598 struct rpc_xprt_switch *,
2599 struct rpc_xprt *,
2600 void *),
2601 void *data)
2602 {
2603 struct rpc_xprt_switch *xps;
2604 struct rpc_xprt *xprt;
2605 unsigned char resvport;
2606 int ret = 0;
2607
2608 rcu_read_lock();
2609 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2610 xprt = xprt_iter_xprt(&clnt->cl_xpi);
2611 if (xps == NULL || xprt == NULL) {
2612 rcu_read_unlock();
2613 return -EAGAIN;
2614 }
2615 resvport = xprt->resvport;
2616 rcu_read_unlock();
2617
2618 xprt = xprt_create_transport(xprtargs);
2619 if (IS_ERR(xprt)) {
2620 ret = PTR_ERR(xprt);
2621 goto out_put_switch;
2622 }
2623 xprt->resvport = resvport;
2624
2625 rpc_xprt_switch_set_roundrobin(xps);
2626 if (setup) {
2627 ret = setup(clnt, xps, xprt, data);
2628 if (ret != 0)
2629 goto out_put_xprt;
2630 }
2631 rpc_xprt_switch_add_xprt(xps, xprt);
2632 out_put_xprt:
2633 xprt_put(xprt);
2634 out_put_switch:
2635 xprt_switch_put(xps);
2636 return ret;
2637 }
2638 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2639
2640 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2641 static void rpc_show_header(void)
2642 {
2643 printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2644 "-timeout ---ops--\n");
2645 }
2646
2647 static void rpc_show_task(const struct rpc_clnt *clnt,
2648 const struct rpc_task *task)
2649 {
2650 const char *rpc_waitq = "none";
2651
2652 if (RPC_IS_QUEUED(task))
2653 rpc_waitq = rpc_qname(task->tk_waitqueue);
2654
2655 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2656 task->tk_pid, task->tk_flags, task->tk_status,
2657 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2658 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2659 task->tk_action, rpc_waitq);
2660 }
2661
2662 void rpc_show_tasks(struct net *net)
2663 {
2664 struct rpc_clnt *clnt;
2665 struct rpc_task *task;
2666 int header = 0;
2667 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2668
2669 spin_lock(&sn->rpc_client_lock);
2670 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2671 spin_lock(&clnt->cl_lock);
2672 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2673 if (!header) {
2674 rpc_show_header();
2675 header++;
2676 }
2677 rpc_show_task(clnt, task);
2678 }
2679 spin_unlock(&clnt->cl_lock);
2680 }
2681 spin_unlock(&sn->rpc_client_lock);
2682 }
2683 #endif
2684
2685 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2686 static int
2687 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2688 struct rpc_xprt *xprt,
2689 void *dummy)
2690 {
2691 return xprt_enable_swap(xprt);
2692 }
2693
2694 int
2695 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2696 {
2697 if (atomic_inc_return(&clnt->cl_swapper) == 1)
2698 return rpc_clnt_iterate_for_each_xprt(clnt,
2699 rpc_clnt_swap_activate_callback, NULL);
2700 return 0;
2701 }
2702 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2703
2704 static int
2705 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2706 struct rpc_xprt *xprt,
2707 void *dummy)
2708 {
2709 xprt_disable_swap(xprt);
2710 return 0;
2711 }
2712
2713 void
2714 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2715 {
2716 if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2717 rpc_clnt_iterate_for_each_xprt(clnt,
2718 rpc_clnt_swap_deactivate_callback, NULL);
2719 }
2720 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2721 #endif /* CONFIG_SUNRPC_SWAP */
Linux with added FPC-III support