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