1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/net/sunrpc/clnt.c
4 *
5 * This file contains the high-level RPC interface.
6 * It is modeled as a finite state machine to support both synchronous
7 * and asynchronous requests.
8 *
9 * - RPC header generation and argument serialization.
10 * - Credential refresh.
11 * - TCP connect handling.
12 * - Retry of operation when it is suspected the operation failed because
13 * of uid squashing on the server, or when the credentials were stale
14 * and need to be refreshed, or when a packet was damaged in transit.
15 * This may be have to be moved to the VFS layer.
16 *
17 * Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
18 * Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
19 */
20
21
22 #include <linux/module.h>
23 #include <linux/types.h>
24 #include <linux/kallsyms.h>
25 #include <linux/mm.h>
26 #include <linux/namei.h>
27 #include <linux/mount.h>
28 #include <linux/slab.h>
29 #include <linux/rcupdate.h>
30 #include <linux/utsname.h>
31 #include <linux/workqueue.h>
32 #include <linux/in.h>
33 #include <linux/in6.h>
34 #include <linux/un.h>
35
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/addr.h>
38 #include <linux/sunrpc/rpc_pipe_fs.h>
39 #include <linux/sunrpc/metrics.h>
40 #include <linux/sunrpc/bc_xprt.h>
41 #include <trace/events/sunrpc.h>
42
43 #include "sunrpc.h"
44 #include "netns.h"
45
46 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
47 # define RPCDBG_FACILITY RPCDBG_CALL
48 #endif
49
50 /*
51 * All RPC clients are linked into this list
52 */
53
54 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
55
56
57 static void call_start(struct rpc_task *task);
58 static void call_reserve(struct rpc_task *task);
59 static void call_reserveresult(struct rpc_task *task);
60 static void call_allocate(struct rpc_task *task);
61 static void call_encode(struct rpc_task *task);
62 static void call_decode(struct rpc_task *task);
63 static void call_bind(struct rpc_task *task);
64 static void call_bind_status(struct rpc_task *task);
65 static void call_transmit(struct rpc_task *task);
66 static void call_status(struct rpc_task *task);
67 static void call_transmit_status(struct rpc_task *task);
68 static void call_refresh(struct rpc_task *task);
69 static void call_refreshresult(struct rpc_task *task);
70 static void call_connect(struct rpc_task *task);
71 static void call_connect_status(struct rpc_task *task);
72
73 static int rpc_encode_header(struct rpc_task *task,
74 struct xdr_stream *xdr);
75 static int rpc_decode_header(struct rpc_task *task,
76 struct xdr_stream *xdr);
77 static int rpc_ping(struct rpc_clnt *clnt);
78 static void rpc_check_timeout(struct rpc_task *task);
79
rpc_register_client(struct rpc_clnt * clnt)80 static void rpc_register_client(struct rpc_clnt *clnt)
81 {
82 struct net *net = rpc_net_ns(clnt);
83 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
84
85 spin_lock(&sn->rpc_client_lock);
86 list_add(&clnt->cl_clients, &sn->all_clients);
87 spin_unlock(&sn->rpc_client_lock);
88 }
89
rpc_unregister_client(struct rpc_clnt * clnt)90 static void rpc_unregister_client(struct rpc_clnt *clnt)
91 {
92 struct net *net = rpc_net_ns(clnt);
93 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
94
95 spin_lock(&sn->rpc_client_lock);
96 list_del(&clnt->cl_clients);
97 spin_unlock(&sn->rpc_client_lock);
98 }
99
__rpc_clnt_remove_pipedir(struct rpc_clnt * clnt)100 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
101 {
102 rpc_remove_client_dir(clnt);
103 }
104
rpc_clnt_remove_pipedir(struct rpc_clnt * clnt)105 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
106 {
107 struct net *net = rpc_net_ns(clnt);
108 struct super_block *pipefs_sb;
109
110 pipefs_sb = rpc_get_sb_net(net);
111 if (pipefs_sb) {
112 if (pipefs_sb == clnt->pipefs_sb)
113 __rpc_clnt_remove_pipedir(clnt);
114 rpc_put_sb_net(net);
115 }
116 }
117
rpc_setup_pipedir_sb(struct super_block * sb,struct rpc_clnt * clnt)118 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
119 struct rpc_clnt *clnt)
120 {
121 static uint32_t clntid;
122 const char *dir_name = clnt->cl_program->pipe_dir_name;
123 char name[15];
124 struct dentry *dir, *dentry;
125
126 dir = rpc_d_lookup_sb(sb, dir_name);
127 if (dir == NULL) {
128 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
129 return dir;
130 }
131 for (;;) {
132 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
133 name[sizeof(name) - 1] = '\0';
134 dentry = rpc_create_client_dir(dir, name, clnt);
135 if (!IS_ERR(dentry))
136 break;
137 if (dentry == ERR_PTR(-EEXIST))
138 continue;
139 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
140 " %s/%s, error %ld\n",
141 dir_name, name, PTR_ERR(dentry));
142 break;
143 }
144 dput(dir);
145 return dentry;
146 }
147
148 static int
rpc_setup_pipedir(struct super_block * pipefs_sb,struct rpc_clnt * clnt)149 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
150 {
151 struct dentry *dentry;
152
153 clnt->pipefs_sb = pipefs_sb;
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
rpc_clnt_skip_event(struct rpc_clnt * clnt,unsigned long event)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
__rpc_clnt_handle_event(struct rpc_clnt * clnt,unsigned long event,struct super_block * sb)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
188 switch (event) {
189 case RPC_PIPEFS_MOUNT:
190 dentry = rpc_setup_pipedir_sb(sb, clnt);
191 if (!dentry)
192 return -ENOENT;
193 if (IS_ERR(dentry))
194 return PTR_ERR(dentry);
195 break;
196 case RPC_PIPEFS_UMOUNT:
197 __rpc_clnt_remove_pipedir(clnt);
198 break;
199 default:
200 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
201 return -ENOTSUPP;
202 }
203 return 0;
204 }
205
__rpc_pipefs_event(struct rpc_clnt * clnt,unsigned long event,struct super_block * sb)206 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
207 struct super_block *sb)
208 {
209 int error = 0;
210
211 for (;; clnt = clnt->cl_parent) {
212 if (!rpc_clnt_skip_event(clnt, event))
213 error = __rpc_clnt_handle_event(clnt, event, sb);
214 if (error || clnt == clnt->cl_parent)
215 break;
216 }
217 return error;
218 }
219
rpc_get_client_for_event(struct net * net,int event)220 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
221 {
222 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
223 struct rpc_clnt *clnt;
224
225 spin_lock(&sn->rpc_client_lock);
226 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
227 if (rpc_clnt_skip_event(clnt, event))
228 continue;
229 spin_unlock(&sn->rpc_client_lock);
230 return clnt;
231 }
232 spin_unlock(&sn->rpc_client_lock);
233 return NULL;
234 }
235
rpc_pipefs_event(struct notifier_block * nb,unsigned long event,void * ptr)236 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
237 void *ptr)
238 {
239 struct super_block *sb = ptr;
240 struct rpc_clnt *clnt;
241 int error = 0;
242
243 while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
244 error = __rpc_pipefs_event(clnt, event, sb);
245 if (error)
246 break;
247 }
248 return error;
249 }
250
251 static struct notifier_block rpc_clients_block = {
252 .notifier_call = rpc_pipefs_event,
253 .priority = SUNRPC_PIPEFS_RPC_PRIO,
254 };
255
rpc_clients_notifier_register(void)256 int rpc_clients_notifier_register(void)
257 {
258 return rpc_pipefs_notifier_register(&rpc_clients_block);
259 }
260
rpc_clients_notifier_unregister(void)261 void rpc_clients_notifier_unregister(void)
262 {
263 return rpc_pipefs_notifier_unregister(&rpc_clients_block);
264 }
265
rpc_clnt_set_transport(struct rpc_clnt * clnt,struct rpc_xprt * xprt,const struct rpc_timeout * timeout)266 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
267 struct rpc_xprt *xprt,
268 const struct rpc_timeout *timeout)
269 {
270 struct rpc_xprt *old;
271
272 spin_lock(&clnt->cl_lock);
273 old = rcu_dereference_protected(clnt->cl_xprt,
274 lockdep_is_held(&clnt->cl_lock));
275
276 if (!xprt_bound(xprt))
277 clnt->cl_autobind = 1;
278
279 clnt->cl_timeout = timeout;
280 rcu_assign_pointer(clnt->cl_xprt, xprt);
281 spin_unlock(&clnt->cl_lock);
282
283 return old;
284 }
285
rpc_clnt_set_nodename(struct rpc_clnt * clnt,const char * nodename)286 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
287 {
288 clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
289 nodename, sizeof(clnt->cl_nodename));
290 }
291
rpc_client_register(struct rpc_clnt * clnt,rpc_authflavor_t pseudoflavor,const char * client_name)292 static int rpc_client_register(struct rpc_clnt *clnt,
293 rpc_authflavor_t pseudoflavor,
294 const char *client_name)
295 {
296 struct rpc_auth_create_args auth_args = {
297 .pseudoflavor = pseudoflavor,
298 .target_name = client_name,
299 };
300 struct rpc_auth *auth;
301 struct net *net = rpc_net_ns(clnt);
302 struct super_block *pipefs_sb;
303 int err;
304
305 rpc_clnt_debugfs_register(clnt);
306
307 pipefs_sb = rpc_get_sb_net(net);
308 if (pipefs_sb) {
309 err = rpc_setup_pipedir(pipefs_sb, clnt);
310 if (err)
311 goto out;
312 }
313
314 rpc_register_client(clnt);
315 if (pipefs_sb)
316 rpc_put_sb_net(net);
317
318 auth = rpcauth_create(&auth_args, clnt);
319 if (IS_ERR(auth)) {
320 dprintk("RPC: Couldn't create auth handle (flavor %u)\n",
321 pseudoflavor);
322 err = PTR_ERR(auth);
323 goto err_auth;
324 }
325 return 0;
326 err_auth:
327 pipefs_sb = rpc_get_sb_net(net);
328 rpc_unregister_client(clnt);
329 __rpc_clnt_remove_pipedir(clnt);
330 out:
331 if (pipefs_sb)
332 rpc_put_sb_net(net);
333 rpc_clnt_debugfs_unregister(clnt);
334 return err;
335 }
336
337 static DEFINE_IDA(rpc_clids);
338
rpc_cleanup_clids(void)339 void rpc_cleanup_clids(void)
340 {
341 ida_destroy(&rpc_clids);
342 }
343
rpc_alloc_clid(struct rpc_clnt * clnt)344 static int rpc_alloc_clid(struct rpc_clnt *clnt)
345 {
346 int clid;
347
348 clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
349 if (clid < 0)
350 return clid;
351 clnt->cl_clid = clid;
352 return 0;
353 }
354
rpc_free_clid(struct rpc_clnt * clnt)355 static void rpc_free_clid(struct rpc_clnt *clnt)
356 {
357 ida_simple_remove(&rpc_clids, clnt->cl_clid);
358 }
359
rpc_new_client(const struct rpc_create_args * args,struct rpc_xprt_switch * xps,struct rpc_xprt * xprt,struct rpc_clnt * parent)360 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
361 struct rpc_xprt_switch *xps,
362 struct rpc_xprt *xprt,
363 struct rpc_clnt *parent)
364 {
365 const struct rpc_program *program = args->program;
366 const struct rpc_version *version;
367 struct rpc_clnt *clnt = NULL;
368 const struct rpc_timeout *timeout;
369 const char *nodename = args->nodename;
370 int err;
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_cred = get_cred(args->cred);
394 clnt->cl_procinfo = version->procs;
395 clnt->cl_maxproc = version->nrprocs;
396 clnt->cl_prog = args->prognumber ? : program->number;
397 clnt->cl_vers = version->number;
398 clnt->cl_stats = program->stats;
399 clnt->cl_metrics = rpc_alloc_iostats(clnt);
400 rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
401 err = -ENOMEM;
402 if (clnt->cl_metrics == NULL)
403 goto out_no_stats;
404 clnt->cl_program = program;
405 INIT_LIST_HEAD(&clnt->cl_tasks);
406 spin_lock_init(&clnt->cl_lock);
407
408 timeout = xprt->timeout;
409 if (args->timeout != NULL) {
410 memcpy(&clnt->cl_timeout_default, args->timeout,
411 sizeof(clnt->cl_timeout_default));
412 timeout = &clnt->cl_timeout_default;
413 }
414
415 rpc_clnt_set_transport(clnt, xprt, timeout);
416 xprt_iter_init(&clnt->cl_xpi, xps);
417 xprt_switch_put(xps);
418
419 clnt->cl_rtt = &clnt->cl_rtt_default;
420 rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
421
422 atomic_set(&clnt->cl_count, 1);
423
424 if (nodename == NULL)
425 nodename = utsname()->nodename;
426 /* save the nodename */
427 rpc_clnt_set_nodename(clnt, nodename);
428
429 err = rpc_client_register(clnt, args->authflavor, args->client_name);
430 if (err)
431 goto out_no_path;
432 if (parent)
433 atomic_inc(&parent->cl_count);
434
435 trace_rpc_clnt_new(clnt, xprt, program->name, args->servername);
436 return clnt;
437
438 out_no_path:
439 rpc_free_iostats(clnt->cl_metrics);
440 out_no_stats:
441 put_cred(clnt->cl_cred);
442 rpc_free_clid(clnt);
443 out_no_clid:
444 kfree(clnt);
445 out_err:
446 rpciod_down();
447 out_no_rpciod:
448 xprt_switch_put(xps);
449 xprt_put(xprt);
450 trace_rpc_clnt_new_err(program->name, args->servername, err);
451 return ERR_PTR(err);
452 }
453
rpc_create_xprt(struct rpc_create_args * args,struct rpc_xprt * xprt)454 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
455 struct rpc_xprt *xprt)
456 {
457 struct rpc_clnt *clnt = NULL;
458 struct rpc_xprt_switch *xps;
459
460 if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
461 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
462 xps = args->bc_xprt->xpt_bc_xps;
463 xprt_switch_get(xps);
464 } else {
465 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
466 if (xps == NULL) {
467 xprt_put(xprt);
468 return ERR_PTR(-ENOMEM);
469 }
470 if (xprt->bc_xprt) {
471 xprt_switch_get(xps);
472 xprt->bc_xprt->xpt_bc_xps = xps;
473 }
474 }
475 clnt = rpc_new_client(args, xps, xprt, NULL);
476 if (IS_ERR(clnt))
477 return clnt;
478
479 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
480 int err = rpc_ping(clnt);
481 if (err != 0) {
482 rpc_shutdown_client(clnt);
483 return ERR_PTR(err);
484 }
485 }
486
487 clnt->cl_softrtry = 1;
488 if (args->flags & (RPC_CLNT_CREATE_HARDRTRY|RPC_CLNT_CREATE_SOFTERR)) {
489 clnt->cl_softrtry = 0;
490 if (args->flags & RPC_CLNT_CREATE_SOFTERR)
491 clnt->cl_softerr = 1;
492 }
493
494 if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
495 clnt->cl_autobind = 1;
496 if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
497 clnt->cl_noretranstimeo = 1;
498 if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
499 clnt->cl_discrtry = 1;
500 if (!(args->flags & RPC_CLNT_CREATE_QUIET))
501 clnt->cl_chatty = 1;
502
503 return clnt;
504 }
505
506 /**
507 * rpc_create - create an RPC client and transport with one call
508 * @args: rpc_clnt create argument structure
509 *
510 * Creates and initializes an RPC transport and an RPC client.
511 *
512 * It can ping the server in order to determine if it is up, and to see if
513 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables
514 * this behavior so asynchronous tasks can also use rpc_create.
515 */
rpc_create(struct rpc_create_args * args)516 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
517 {
518 struct rpc_xprt *xprt;
519 struct xprt_create xprtargs = {
520 .net = args->net,
521 .ident = args->protocol,
522 .srcaddr = args->saddress,
523 .dstaddr = args->address,
524 .addrlen = args->addrsize,
525 .servername = args->servername,
526 .bc_xprt = args->bc_xprt,
527 };
528 char servername[48];
529 struct rpc_clnt *clnt;
530 int i;
531
532 if (args->bc_xprt) {
533 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
534 xprt = args->bc_xprt->xpt_bc_xprt;
535 if (xprt) {
536 xprt_get(xprt);
537 return rpc_create_xprt(args, xprt);
538 }
539 }
540
541 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
542 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
543 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
544 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
545 /*
546 * If the caller chooses not to specify a hostname, whip
547 * up a string representation of the passed-in address.
548 */
549 if (xprtargs.servername == NULL) {
550 struct sockaddr_un *sun =
551 (struct sockaddr_un *)args->address;
552 struct sockaddr_in *sin =
553 (struct sockaddr_in *)args->address;
554 struct sockaddr_in6 *sin6 =
555 (struct sockaddr_in6 *)args->address;
556
557 servername[0] = '\0';
558 switch (args->address->sa_family) {
559 case AF_LOCAL:
560 snprintf(servername, sizeof(servername), "%s",
561 sun->sun_path);
562 break;
563 case AF_INET:
564 snprintf(servername, sizeof(servername), "%pI4",
565 &sin->sin_addr.s_addr);
566 break;
567 case AF_INET6:
568 snprintf(servername, sizeof(servername), "%pI6",
569 &sin6->sin6_addr);
570 break;
571 default:
572 /* caller wants default server name, but
573 * address family isn't recognized. */
574 return ERR_PTR(-EINVAL);
575 }
576 xprtargs.servername = servername;
577 }
578
579 xprt = xprt_create_transport(&xprtargs);
580 if (IS_ERR(xprt))
581 return (struct rpc_clnt *)xprt;
582
583 /*
584 * By default, kernel RPC client connects from a reserved port.
585 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
586 * but it is always enabled for rpciod, which handles the connect
587 * operation.
588 */
589 xprt->resvport = 1;
590 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
591 xprt->resvport = 0;
592 xprt->reuseport = 0;
593 if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
594 xprt->reuseport = 1;
595
596 clnt = rpc_create_xprt(args, xprt);
597 if (IS_ERR(clnt) || args->nconnect <= 1)
598 return clnt;
599
600 for (i = 0; i < args->nconnect - 1; i++) {
601 if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
602 break;
603 }
604 return clnt;
605 }
606 EXPORT_SYMBOL_GPL(rpc_create);
607
608 /*
609 * This function clones the RPC client structure. It allows us to share the
610 * same transport while varying parameters such as the authentication
611 * flavour.
612 */
__rpc_clone_client(struct rpc_create_args * args,struct rpc_clnt * clnt)613 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
614 struct rpc_clnt *clnt)
615 {
616 struct rpc_xprt_switch *xps;
617 struct rpc_xprt *xprt;
618 struct rpc_clnt *new;
619 int err;
620
621 err = -ENOMEM;
622 rcu_read_lock();
623 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
624 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
625 rcu_read_unlock();
626 if (xprt == NULL || xps == NULL) {
627 xprt_put(xprt);
628 xprt_switch_put(xps);
629 goto out_err;
630 }
631 args->servername = xprt->servername;
632 args->nodename = clnt->cl_nodename;
633
634 new = rpc_new_client(args, xps, xprt, clnt);
635 if (IS_ERR(new))
636 return new;
637
638 /* Turn off autobind on clones */
639 new->cl_autobind = 0;
640 new->cl_softrtry = clnt->cl_softrtry;
641 new->cl_softerr = clnt->cl_softerr;
642 new->cl_noretranstimeo = clnt->cl_noretranstimeo;
643 new->cl_discrtry = clnt->cl_discrtry;
644 new->cl_chatty = clnt->cl_chatty;
645 new->cl_principal = clnt->cl_principal;
646 return new;
647
648 out_err:
649 trace_rpc_clnt_clone_err(clnt, err);
650 return ERR_PTR(err);
651 }
652
653 /**
654 * rpc_clone_client - Clone an RPC client structure
655 *
656 * @clnt: RPC client whose parameters are copied
657 *
658 * Returns a fresh RPC client or an ERR_PTR.
659 */
rpc_clone_client(struct rpc_clnt * clnt)660 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
661 {
662 struct rpc_create_args args = {
663 .program = clnt->cl_program,
664 .prognumber = clnt->cl_prog,
665 .version = clnt->cl_vers,
666 .authflavor = clnt->cl_auth->au_flavor,
667 .cred = clnt->cl_cred,
668 };
669 return __rpc_clone_client(&args, clnt);
670 }
671 EXPORT_SYMBOL_GPL(rpc_clone_client);
672
673 /**
674 * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
675 *
676 * @clnt: RPC client whose parameters are copied
677 * @flavor: security flavor for new client
678 *
679 * Returns a fresh RPC client or an ERR_PTR.
680 */
681 struct rpc_clnt *
rpc_clone_client_set_auth(struct rpc_clnt * clnt,rpc_authflavor_t flavor)682 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
683 {
684 struct rpc_create_args args = {
685 .program = clnt->cl_program,
686 .prognumber = clnt->cl_prog,
687 .version = clnt->cl_vers,
688 .authflavor = flavor,
689 .cred = clnt->cl_cred,
690 };
691 return __rpc_clone_client(&args, clnt);
692 }
693 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
694
695 /**
696 * rpc_switch_client_transport: switch the RPC transport on the fly
697 * @clnt: pointer to a struct rpc_clnt
698 * @args: pointer to the new transport arguments
699 * @timeout: pointer to the new timeout parameters
700 *
701 * This function allows the caller to switch the RPC transport for the
702 * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
703 * server, for instance. It assumes that the caller has ensured that
704 * there are no active RPC tasks by using some form of locking.
705 *
706 * Returns zero if "clnt" is now using the new xprt. Otherwise a
707 * negative errno is returned, and "clnt" continues to use the old
708 * xprt.
709 */
rpc_switch_client_transport(struct rpc_clnt * clnt,struct xprt_create * args,const struct rpc_timeout * timeout)710 int rpc_switch_client_transport(struct rpc_clnt *clnt,
711 struct xprt_create *args,
712 const struct rpc_timeout *timeout)
713 {
714 const struct rpc_timeout *old_timeo;
715 rpc_authflavor_t pseudoflavor;
716 struct rpc_xprt_switch *xps, *oldxps;
717 struct rpc_xprt *xprt, *old;
718 struct rpc_clnt *parent;
719 int err;
720
721 xprt = xprt_create_transport(args);
722 if (IS_ERR(xprt))
723 return PTR_ERR(xprt);
724
725 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
726 if (xps == NULL) {
727 xprt_put(xprt);
728 return -ENOMEM;
729 }
730
731 pseudoflavor = clnt->cl_auth->au_flavor;
732
733 old_timeo = clnt->cl_timeout;
734 old = rpc_clnt_set_transport(clnt, xprt, timeout);
735 oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
736
737 rpc_unregister_client(clnt);
738 __rpc_clnt_remove_pipedir(clnt);
739 rpc_clnt_debugfs_unregister(clnt);
740
741 /*
742 * A new transport was created. "clnt" therefore
743 * becomes the root of a new cl_parent tree. clnt's
744 * children, if it has any, still point to the old xprt.
745 */
746 parent = clnt->cl_parent;
747 clnt->cl_parent = clnt;
748
749 /*
750 * The old rpc_auth cache cannot be re-used. GSS
751 * contexts in particular are between a single
752 * client and server.
753 */
754 err = rpc_client_register(clnt, pseudoflavor, NULL);
755 if (err)
756 goto out_revert;
757
758 synchronize_rcu();
759 if (parent != clnt)
760 rpc_release_client(parent);
761 xprt_switch_put(oldxps);
762 xprt_put(old);
763 trace_rpc_clnt_replace_xprt(clnt);
764 return 0;
765
766 out_revert:
767 xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
768 rpc_clnt_set_transport(clnt, old, old_timeo);
769 clnt->cl_parent = parent;
770 rpc_client_register(clnt, pseudoflavor, NULL);
771 xprt_switch_put(xps);
772 xprt_put(xprt);
773 trace_rpc_clnt_replace_xprt_err(clnt);
774 return err;
775 }
776 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
777
778 static
rpc_clnt_xprt_iter_init(struct rpc_clnt * clnt,struct rpc_xprt_iter * xpi)779 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
780 {
781 struct rpc_xprt_switch *xps;
782
783 rcu_read_lock();
784 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
785 rcu_read_unlock();
786 if (xps == NULL)
787 return -EAGAIN;
788 xprt_iter_init_listall(xpi, xps);
789 xprt_switch_put(xps);
790 return 0;
791 }
792
793 /**
794 * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
795 * @clnt: pointer to client
796 * @fn: function to apply
797 * @data: void pointer to function data
798 *
799 * Iterates through the list of RPC transports currently attached to the
800 * client and applies the function fn(clnt, xprt, data).
801 *
802 * On error, the iteration stops, and the function returns the error value.
803 */
rpc_clnt_iterate_for_each_xprt(struct rpc_clnt * clnt,int (* fn)(struct rpc_clnt *,struct rpc_xprt *,void *),void * data)804 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
805 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
806 void *data)
807 {
808 struct rpc_xprt_iter xpi;
809 int ret;
810
811 ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
812 if (ret)
813 return ret;
814 for (;;) {
815 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
816
817 if (!xprt)
818 break;
819 ret = fn(clnt, xprt, data);
820 xprt_put(xprt);
821 if (ret < 0)
822 break;
823 }
824 xprt_iter_destroy(&xpi);
825 return ret;
826 }
827 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
828
829 /*
830 * Kill all tasks for the given client.
831 * XXX: kill their descendants as well?
832 */
rpc_killall_tasks(struct rpc_clnt * clnt)833 void rpc_killall_tasks(struct rpc_clnt *clnt)
834 {
835 struct rpc_task *rovr;
836
837
838 if (list_empty(&clnt->cl_tasks))
839 return;
840
841 /*
842 * Spin lock all_tasks to prevent changes...
843 */
844 trace_rpc_clnt_killall(clnt);
845 spin_lock(&clnt->cl_lock);
846 list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
847 rpc_signal_task(rovr);
848 spin_unlock(&clnt->cl_lock);
849 }
850 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
851
852 /*
853 * Properly shut down an RPC client, terminating all outstanding
854 * requests.
855 */
rpc_shutdown_client(struct rpc_clnt * clnt)856 void rpc_shutdown_client(struct rpc_clnt *clnt)
857 {
858 might_sleep();
859
860 trace_rpc_clnt_shutdown(clnt);
861
862 while (!list_empty(&clnt->cl_tasks)) {
863 rpc_killall_tasks(clnt);
864 wait_event_timeout(destroy_wait,
865 list_empty(&clnt->cl_tasks), 1*HZ);
866 }
867
868 rpc_release_client(clnt);
869 }
870 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
871
872 /*
873 * Free an RPC client
874 */
rpc_free_client_work(struct work_struct * work)875 static void rpc_free_client_work(struct work_struct *work)
876 {
877 struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
878
879 trace_rpc_clnt_free(clnt);
880
881 /* These might block on processes that might allocate memory,
882 * so they cannot be called in rpciod, so they are handled separately
883 * here.
884 */
885 rpc_clnt_debugfs_unregister(clnt);
886 rpc_free_clid(clnt);
887 rpc_clnt_remove_pipedir(clnt);
888 xprt_put(rcu_dereference_raw(clnt->cl_xprt));
889
890 kfree(clnt);
891 rpciod_down();
892 }
893 static struct rpc_clnt *
rpc_free_client(struct rpc_clnt * clnt)894 rpc_free_client(struct rpc_clnt *clnt)
895 {
896 struct rpc_clnt *parent = NULL;
897
898 trace_rpc_clnt_release(clnt);
899 if (clnt->cl_parent != clnt)
900 parent = clnt->cl_parent;
901 rpc_unregister_client(clnt);
902 rpc_free_iostats(clnt->cl_metrics);
903 clnt->cl_metrics = NULL;
904 xprt_iter_destroy(&clnt->cl_xpi);
905 put_cred(clnt->cl_cred);
906
907 INIT_WORK(&clnt->cl_work, rpc_free_client_work);
908 schedule_work(&clnt->cl_work);
909 return parent;
910 }
911
912 /*
913 * Free an RPC client
914 */
915 static struct rpc_clnt *
rpc_free_auth(struct rpc_clnt * clnt)916 rpc_free_auth(struct rpc_clnt *clnt)
917 {
918 if (clnt->cl_auth == NULL)
919 return rpc_free_client(clnt);
920
921 /*
922 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
923 * release remaining GSS contexts. This mechanism ensures
924 * that it can do so safely.
925 */
926 atomic_inc(&clnt->cl_count);
927 rpcauth_release(clnt->cl_auth);
928 clnt->cl_auth = NULL;
929 if (atomic_dec_and_test(&clnt->cl_count))
930 return rpc_free_client(clnt);
931 return NULL;
932 }
933
934 /*
935 * Release reference to the RPC client
936 */
937 void
rpc_release_client(struct rpc_clnt * clnt)938 rpc_release_client(struct rpc_clnt *clnt)
939 {
940 do {
941 if (list_empty(&clnt->cl_tasks))
942 wake_up(&destroy_wait);
943 if (!atomic_dec_and_test(&clnt->cl_count))
944 break;
945 clnt = rpc_free_auth(clnt);
946 } while (clnt != NULL);
947 }
948 EXPORT_SYMBOL_GPL(rpc_release_client);
949
950 /**
951 * rpc_bind_new_program - bind a new RPC program to an existing client
952 * @old: old rpc_client
953 * @program: rpc program to set
954 * @vers: rpc program version
955 *
956 * Clones the rpc client and sets up a new RPC program. This is mainly
957 * of use for enabling different RPC programs to share the same transport.
958 * The Sun NFSv2/v3 ACL protocol can do this.
959 */
rpc_bind_new_program(struct rpc_clnt * old,const struct rpc_program * program,u32 vers)960 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
961 const struct rpc_program *program,
962 u32 vers)
963 {
964 struct rpc_create_args args = {
965 .program = program,
966 .prognumber = program->number,
967 .version = vers,
968 .authflavor = old->cl_auth->au_flavor,
969 .cred = old->cl_cred,
970 };
971 struct rpc_clnt *clnt;
972 int err;
973
974 clnt = __rpc_clone_client(&args, old);
975 if (IS_ERR(clnt))
976 goto out;
977 err = rpc_ping(clnt);
978 if (err != 0) {
979 rpc_shutdown_client(clnt);
980 clnt = ERR_PTR(err);
981 }
982 out:
983 return clnt;
984 }
985 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
986
987 struct rpc_xprt *
rpc_task_get_xprt(struct rpc_clnt * clnt,struct rpc_xprt * xprt)988 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
989 {
990 struct rpc_xprt_switch *xps;
991
992 if (!xprt)
993 return NULL;
994 rcu_read_lock();
995 xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
996 atomic_long_inc(&xps->xps_queuelen);
997 rcu_read_unlock();
998 atomic_long_inc(&xprt->queuelen);
999
1000 return xprt;
1001 }
1002
1003 static void
rpc_task_release_xprt(struct rpc_clnt * clnt,struct rpc_xprt * xprt)1004 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1005 {
1006 struct rpc_xprt_switch *xps;
1007
1008 atomic_long_dec(&xprt->queuelen);
1009 rcu_read_lock();
1010 xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1011 atomic_long_dec(&xps->xps_queuelen);
1012 rcu_read_unlock();
1013
1014 xprt_put(xprt);
1015 }
1016
rpc_task_release_transport(struct rpc_task * task)1017 void rpc_task_release_transport(struct rpc_task *task)
1018 {
1019 struct rpc_xprt *xprt = task->tk_xprt;
1020
1021 if (xprt) {
1022 task->tk_xprt = NULL;
1023 if (task->tk_client)
1024 rpc_task_release_xprt(task->tk_client, xprt);
1025 else
1026 xprt_put(xprt);
1027 }
1028 }
1029 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1030
rpc_task_release_client(struct rpc_task * task)1031 void rpc_task_release_client(struct rpc_task *task)
1032 {
1033 struct rpc_clnt *clnt = task->tk_client;
1034
1035 rpc_task_release_transport(task);
1036 if (clnt != NULL) {
1037 /* Remove from client task list */
1038 spin_lock(&clnt->cl_lock);
1039 list_del(&task->tk_task);
1040 spin_unlock(&clnt->cl_lock);
1041 task->tk_client = NULL;
1042
1043 rpc_release_client(clnt);
1044 }
1045 }
1046
1047 static struct rpc_xprt *
rpc_task_get_first_xprt(struct rpc_clnt * clnt)1048 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1049 {
1050 struct rpc_xprt *xprt;
1051
1052 rcu_read_lock();
1053 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1054 rcu_read_unlock();
1055 return rpc_task_get_xprt(clnt, xprt);
1056 }
1057
1058 static struct rpc_xprt *
rpc_task_get_next_xprt(struct rpc_clnt * clnt)1059 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1060 {
1061 return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1062 }
1063
1064 static
rpc_task_set_transport(struct rpc_task * task,struct rpc_clnt * clnt)1065 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1066 {
1067 if (task->tk_xprt)
1068 return;
1069 if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1070 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1071 else
1072 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1073 }
1074
1075 static
rpc_task_set_client(struct rpc_task * task,struct rpc_clnt * clnt)1076 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1077 {
1078
1079 if (clnt != NULL) {
1080 rpc_task_set_transport(task, clnt);
1081 task->tk_client = clnt;
1082 atomic_inc(&clnt->cl_count);
1083 if (clnt->cl_softrtry)
1084 task->tk_flags |= RPC_TASK_SOFT;
1085 if (clnt->cl_softerr)
1086 task->tk_flags |= RPC_TASK_TIMEOUT;
1087 if (clnt->cl_noretranstimeo)
1088 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1089 if (atomic_read(&clnt->cl_swapper))
1090 task->tk_flags |= RPC_TASK_SWAPPER;
1091 /* Add to the client's list of all tasks */
1092 spin_lock(&clnt->cl_lock);
1093 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1094 spin_unlock(&clnt->cl_lock);
1095 }
1096 }
1097
1098 static void
rpc_task_set_rpc_message(struct rpc_task * task,const struct rpc_message * msg)1099 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1100 {
1101 if (msg != NULL) {
1102 task->tk_msg.rpc_proc = msg->rpc_proc;
1103 task->tk_msg.rpc_argp = msg->rpc_argp;
1104 task->tk_msg.rpc_resp = msg->rpc_resp;
1105 task->tk_msg.rpc_cred = msg->rpc_cred;
1106 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1107 get_cred(task->tk_msg.rpc_cred);
1108 }
1109 }
1110
1111 /*
1112 * Default callback for async RPC calls
1113 */
1114 static void
rpc_default_callback(struct rpc_task * task,void * data)1115 rpc_default_callback(struct rpc_task *task, void *data)
1116 {
1117 }
1118
1119 static const struct rpc_call_ops rpc_default_ops = {
1120 .rpc_call_done = rpc_default_callback,
1121 };
1122
1123 /**
1124 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1125 * @task_setup_data: pointer to task initialisation data
1126 */
rpc_run_task(const struct rpc_task_setup * task_setup_data)1127 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1128 {
1129 struct rpc_task *task;
1130
1131 task = rpc_new_task(task_setup_data);
1132
1133 if (!RPC_IS_ASYNC(task))
1134 task->tk_flags |= RPC_TASK_CRED_NOREF;
1135
1136 rpc_task_set_client(task, task_setup_data->rpc_client);
1137 rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1138
1139 if (task->tk_action == NULL)
1140 rpc_call_start(task);
1141
1142 atomic_inc(&task->tk_count);
1143 rpc_execute(task);
1144 return task;
1145 }
1146 EXPORT_SYMBOL_GPL(rpc_run_task);
1147
1148 /**
1149 * rpc_call_sync - Perform a synchronous RPC call
1150 * @clnt: pointer to RPC client
1151 * @msg: RPC call parameters
1152 * @flags: RPC call flags
1153 */
rpc_call_sync(struct rpc_clnt * clnt,const struct rpc_message * msg,int flags)1154 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1155 {
1156 struct rpc_task *task;
1157 struct rpc_task_setup task_setup_data = {
1158 .rpc_client = clnt,
1159 .rpc_message = msg,
1160 .callback_ops = &rpc_default_ops,
1161 .flags = flags,
1162 };
1163 int status;
1164
1165 WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1166 if (flags & RPC_TASK_ASYNC) {
1167 rpc_release_calldata(task_setup_data.callback_ops,
1168 task_setup_data.callback_data);
1169 return -EINVAL;
1170 }
1171
1172 task = rpc_run_task(&task_setup_data);
1173 if (IS_ERR(task))
1174 return PTR_ERR(task);
1175 status = task->tk_status;
1176 rpc_put_task(task);
1177 return status;
1178 }
1179 EXPORT_SYMBOL_GPL(rpc_call_sync);
1180
1181 /**
1182 * rpc_call_async - Perform an asynchronous RPC call
1183 * @clnt: pointer to RPC client
1184 * @msg: RPC call parameters
1185 * @flags: RPC call flags
1186 * @tk_ops: RPC call ops
1187 * @data: user call data
1188 */
1189 int
rpc_call_async(struct rpc_clnt * clnt,const struct rpc_message * msg,int flags,const struct rpc_call_ops * tk_ops,void * data)1190 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1191 const struct rpc_call_ops *tk_ops, void *data)
1192 {
1193 struct rpc_task *task;
1194 struct rpc_task_setup task_setup_data = {
1195 .rpc_client = clnt,
1196 .rpc_message = msg,
1197 .callback_ops = tk_ops,
1198 .callback_data = data,
1199 .flags = flags|RPC_TASK_ASYNC,
1200 };
1201
1202 task = rpc_run_task(&task_setup_data);
1203 if (IS_ERR(task))
1204 return PTR_ERR(task);
1205 rpc_put_task(task);
1206 return 0;
1207 }
1208 EXPORT_SYMBOL_GPL(rpc_call_async);
1209
1210 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1211 static void call_bc_encode(struct rpc_task *task);
1212
1213 /**
1214 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1215 * rpc_execute against it
1216 * @req: RPC request
1217 */
rpc_run_bc_task(struct rpc_rqst * req)1218 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1219 {
1220 struct rpc_task *task;
1221 struct rpc_task_setup task_setup_data = {
1222 .callback_ops = &rpc_default_ops,
1223 .flags = RPC_TASK_SOFTCONN |
1224 RPC_TASK_NO_RETRANS_TIMEOUT,
1225 };
1226
1227 dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1228 /*
1229 * Create an rpc_task to send the data
1230 */
1231 task = rpc_new_task(&task_setup_data);
1232 xprt_init_bc_request(req, task);
1233
1234 task->tk_action = call_bc_encode;
1235 atomic_inc(&task->tk_count);
1236 WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1237 rpc_execute(task);
1238
1239 dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1240 return task;
1241 }
1242 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1243
1244 /**
1245 * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1246 * @req: RPC request to prepare
1247 * @pages: vector of struct page pointers
1248 * @base: offset in first page where receive should start, in bytes
1249 * @len: expected size of the upper layer data payload, in bytes
1250 * @hdrsize: expected size of upper layer reply header, in XDR words
1251 *
1252 */
rpc_prepare_reply_pages(struct rpc_rqst * req,struct page ** pages,unsigned int base,unsigned int len,unsigned int hdrsize)1253 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1254 unsigned int base, unsigned int len,
1255 unsigned int hdrsize)
1256 {
1257 /* Subtract one to force an extra word of buffer space for the
1258 * payload's XDR pad to fall into the rcv_buf's tail iovec.
1259 */
1260 hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign - 1;
1261
1262 xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1263 trace_rpc_xdr_reply_pages(req->rq_task, &req->rq_rcv_buf);
1264 }
1265 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1266
1267 void
rpc_call_start(struct rpc_task * task)1268 rpc_call_start(struct rpc_task *task)
1269 {
1270 task->tk_action = call_start;
1271 }
1272 EXPORT_SYMBOL_GPL(rpc_call_start);
1273
1274 /**
1275 * rpc_peeraddr - extract remote peer address from clnt's xprt
1276 * @clnt: RPC client structure
1277 * @buf: target buffer
1278 * @bufsize: length of target buffer
1279 *
1280 * Returns the number of bytes that are actually in the stored address.
1281 */
rpc_peeraddr(struct rpc_clnt * clnt,struct sockaddr * buf,size_t bufsize)1282 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1283 {
1284 size_t bytes;
1285 struct rpc_xprt *xprt;
1286
1287 rcu_read_lock();
1288 xprt = rcu_dereference(clnt->cl_xprt);
1289
1290 bytes = xprt->addrlen;
1291 if (bytes > bufsize)
1292 bytes = bufsize;
1293 memcpy(buf, &xprt->addr, bytes);
1294 rcu_read_unlock();
1295
1296 return bytes;
1297 }
1298 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1299
1300 /**
1301 * rpc_peeraddr2str - return remote peer address in printable format
1302 * @clnt: RPC client structure
1303 * @format: address format
1304 *
1305 * NB: the lifetime of the memory referenced by the returned pointer is
1306 * the same as the rpc_xprt itself. As long as the caller uses this
1307 * pointer, it must hold the RCU read lock.
1308 */
rpc_peeraddr2str(struct rpc_clnt * clnt,enum rpc_display_format_t format)1309 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1310 enum rpc_display_format_t format)
1311 {
1312 struct rpc_xprt *xprt;
1313
1314 xprt = rcu_dereference(clnt->cl_xprt);
1315
1316 if (xprt->address_strings[format] != NULL)
1317 return xprt->address_strings[format];
1318 else
1319 return "unprintable";
1320 }
1321 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1322
1323 static const struct sockaddr_in rpc_inaddr_loopback = {
1324 .sin_family = AF_INET,
1325 .sin_addr.s_addr = htonl(INADDR_ANY),
1326 };
1327
1328 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1329 .sin6_family = AF_INET6,
1330 .sin6_addr = IN6ADDR_ANY_INIT,
1331 };
1332
1333 /*
1334 * Try a getsockname() on a connected datagram socket. Using a
1335 * connected datagram socket prevents leaving a socket in TIME_WAIT.
1336 * This conserves the ephemeral port number space.
1337 *
1338 * Returns zero and fills in "buf" if successful; otherwise, a
1339 * negative errno is returned.
1340 */
rpc_sockname(struct net * net,struct sockaddr * sap,size_t salen,struct sockaddr * buf)1341 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1342 struct sockaddr *buf)
1343 {
1344 struct socket *sock;
1345 int err;
1346
1347 err = __sock_create(net, sap->sa_family,
1348 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1349 if (err < 0) {
1350 dprintk("RPC: can't create UDP socket (%d)\n", err);
1351 goto out;
1352 }
1353
1354 switch (sap->sa_family) {
1355 case AF_INET:
1356 err = kernel_bind(sock,
1357 (struct sockaddr *)&rpc_inaddr_loopback,
1358 sizeof(rpc_inaddr_loopback));
1359 break;
1360 case AF_INET6:
1361 err = kernel_bind(sock,
1362 (struct sockaddr *)&rpc_in6addr_loopback,
1363 sizeof(rpc_in6addr_loopback));
1364 break;
1365 default:
1366 err = -EAFNOSUPPORT;
1367 goto out_release;
1368 }
1369 if (err < 0) {
1370 dprintk("RPC: can't bind UDP socket (%d)\n", err);
1371 goto out_release;
1372 }
1373
1374 err = kernel_connect(sock, sap, salen, 0);
1375 if (err < 0) {
1376 dprintk("RPC: can't connect UDP socket (%d)\n", err);
1377 goto out_release;
1378 }
1379
1380 err = kernel_getsockname(sock, buf);
1381 if (err < 0) {
1382 dprintk("RPC: getsockname failed (%d)\n", err);
1383 goto out_release;
1384 }
1385
1386 err = 0;
1387 if (buf->sa_family == AF_INET6) {
1388 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1389 sin6->sin6_scope_id = 0;
1390 }
1391 dprintk("RPC: %s succeeded\n", __func__);
1392
1393 out_release:
1394 sock_release(sock);
1395 out:
1396 return err;
1397 }
1398
1399 /*
1400 * Scraping a connected socket failed, so we don't have a useable
1401 * local address. Fallback: generate an address that will prevent
1402 * the server from calling us back.
1403 *
1404 * Returns zero and fills in "buf" if successful; otherwise, a
1405 * negative errno is returned.
1406 */
rpc_anyaddr(int family,struct sockaddr * buf,size_t buflen)1407 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1408 {
1409 switch (family) {
1410 case AF_INET:
1411 if (buflen < sizeof(rpc_inaddr_loopback))
1412 return -EINVAL;
1413 memcpy(buf, &rpc_inaddr_loopback,
1414 sizeof(rpc_inaddr_loopback));
1415 break;
1416 case AF_INET6:
1417 if (buflen < sizeof(rpc_in6addr_loopback))
1418 return -EINVAL;
1419 memcpy(buf, &rpc_in6addr_loopback,
1420 sizeof(rpc_in6addr_loopback));
1421 break;
1422 default:
1423 dprintk("RPC: %s: address family not supported\n",
1424 __func__);
1425 return -EAFNOSUPPORT;
1426 }
1427 dprintk("RPC: %s: succeeded\n", __func__);
1428 return 0;
1429 }
1430
1431 /**
1432 * rpc_localaddr - discover local endpoint address for an RPC client
1433 * @clnt: RPC client structure
1434 * @buf: target buffer
1435 * @buflen: size of target buffer, in bytes
1436 *
1437 * Returns zero and fills in "buf" and "buflen" if successful;
1438 * otherwise, a negative errno is returned.
1439 *
1440 * This works even if the underlying transport is not currently connected,
1441 * or if the upper layer never previously provided a source address.
1442 *
1443 * The result of this function call is transient: multiple calls in
1444 * succession may give different results, depending on how local
1445 * networking configuration changes over time.
1446 */
rpc_localaddr(struct rpc_clnt * clnt,struct sockaddr * buf,size_t buflen)1447 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1448 {
1449 struct sockaddr_storage address;
1450 struct sockaddr *sap = (struct sockaddr *)&address;
1451 struct rpc_xprt *xprt;
1452 struct net *net;
1453 size_t salen;
1454 int err;
1455
1456 rcu_read_lock();
1457 xprt = rcu_dereference(clnt->cl_xprt);
1458 salen = xprt->addrlen;
1459 memcpy(sap, &xprt->addr, salen);
1460 net = get_net(xprt->xprt_net);
1461 rcu_read_unlock();
1462
1463 rpc_set_port(sap, 0);
1464 err = rpc_sockname(net, sap, salen, buf);
1465 put_net(net);
1466 if (err != 0)
1467 /* Couldn't discover local address, return ANYADDR */
1468 return rpc_anyaddr(sap->sa_family, buf, buflen);
1469 return 0;
1470 }
1471 EXPORT_SYMBOL_GPL(rpc_localaddr);
1472
1473 void
rpc_setbufsize(struct rpc_clnt * clnt,unsigned int sndsize,unsigned int rcvsize)1474 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1475 {
1476 struct rpc_xprt *xprt;
1477
1478 rcu_read_lock();
1479 xprt = rcu_dereference(clnt->cl_xprt);
1480 if (xprt->ops->set_buffer_size)
1481 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1482 rcu_read_unlock();
1483 }
1484 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1485
1486 /**
1487 * rpc_net_ns - Get the network namespace for this RPC client
1488 * @clnt: RPC client to query
1489 *
1490 */
rpc_net_ns(struct rpc_clnt * clnt)1491 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1492 {
1493 struct net *ret;
1494
1495 rcu_read_lock();
1496 ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1497 rcu_read_unlock();
1498 return ret;
1499 }
1500 EXPORT_SYMBOL_GPL(rpc_net_ns);
1501
1502 /**
1503 * rpc_max_payload - Get maximum payload size for a transport, in bytes
1504 * @clnt: RPC client to query
1505 *
1506 * For stream transports, this is one RPC record fragment (see RFC
1507 * 1831), as we don't support multi-record requests yet. For datagram
1508 * transports, this is the size of an IP packet minus the IP, UDP, and
1509 * RPC header sizes.
1510 */
rpc_max_payload(struct rpc_clnt * clnt)1511 size_t rpc_max_payload(struct rpc_clnt *clnt)
1512 {
1513 size_t ret;
1514
1515 rcu_read_lock();
1516 ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1517 rcu_read_unlock();
1518 return ret;
1519 }
1520 EXPORT_SYMBOL_GPL(rpc_max_payload);
1521
1522 /**
1523 * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1524 * @clnt: RPC client to query
1525 */
rpc_max_bc_payload(struct rpc_clnt * clnt)1526 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1527 {
1528 struct rpc_xprt *xprt;
1529 size_t ret;
1530
1531 rcu_read_lock();
1532 xprt = rcu_dereference(clnt->cl_xprt);
1533 ret = xprt->ops->bc_maxpayload(xprt);
1534 rcu_read_unlock();
1535 return ret;
1536 }
1537 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1538
rpc_num_bc_slots(struct rpc_clnt * clnt)1539 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1540 {
1541 struct rpc_xprt *xprt;
1542 unsigned int ret;
1543
1544 rcu_read_lock();
1545 xprt = rcu_dereference(clnt->cl_xprt);
1546 ret = xprt->ops->bc_num_slots(xprt);
1547 rcu_read_unlock();
1548 return ret;
1549 }
1550 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1551
1552 /**
1553 * rpc_force_rebind - force transport to check that remote port is unchanged
1554 * @clnt: client to rebind
1555 *
1556 */
rpc_force_rebind(struct rpc_clnt * clnt)1557 void rpc_force_rebind(struct rpc_clnt *clnt)
1558 {
1559 if (clnt->cl_autobind) {
1560 rcu_read_lock();
1561 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1562 rcu_read_unlock();
1563 }
1564 }
1565 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1566
1567 static int
__rpc_restart_call(struct rpc_task * task,void (* action)(struct rpc_task *))1568 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1569 {
1570 task->tk_status = 0;
1571 task->tk_rpc_status = 0;
1572 task->tk_action = action;
1573 return 1;
1574 }
1575
1576 /*
1577 * Restart an (async) RPC call. Usually called from within the
1578 * exit handler.
1579 */
1580 int
rpc_restart_call(struct rpc_task * task)1581 rpc_restart_call(struct rpc_task *task)
1582 {
1583 return __rpc_restart_call(task, call_start);
1584 }
1585 EXPORT_SYMBOL_GPL(rpc_restart_call);
1586
1587 /*
1588 * Restart an (async) RPC call from the call_prepare state.
1589 * Usually called from within the exit handler.
1590 */
1591 int
rpc_restart_call_prepare(struct rpc_task * task)1592 rpc_restart_call_prepare(struct rpc_task *task)
1593 {
1594 if (task->tk_ops->rpc_call_prepare != NULL)
1595 return __rpc_restart_call(task, rpc_prepare_task);
1596 return rpc_restart_call(task);
1597 }
1598 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1599
1600 const char
rpc_proc_name(const struct rpc_task * task)1601 *rpc_proc_name(const struct rpc_task *task)
1602 {
1603 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1604
1605 if (proc) {
1606 if (proc->p_name)
1607 return proc->p_name;
1608 else
1609 return "NULL";
1610 } else
1611 return "no proc";
1612 }
1613
1614 static void
__rpc_call_rpcerror(struct rpc_task * task,int tk_status,int rpc_status)1615 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1616 {
1617 trace_rpc_call_rpcerror(task, tk_status, rpc_status);
1618 task->tk_rpc_status = rpc_status;
1619 rpc_exit(task, tk_status);
1620 }
1621
1622 static void
rpc_call_rpcerror(struct rpc_task * task,int status)1623 rpc_call_rpcerror(struct rpc_task *task, int status)
1624 {
1625 __rpc_call_rpcerror(task, status, status);
1626 }
1627
1628 /*
1629 * 0. Initial state
1630 *
1631 * Other FSM states can be visited zero or more times, but
1632 * this state is visited exactly once for each RPC.
1633 */
1634 static void
call_start(struct rpc_task * task)1635 call_start(struct rpc_task *task)
1636 {
1637 struct rpc_clnt *clnt = task->tk_client;
1638 int idx = task->tk_msg.rpc_proc->p_statidx;
1639
1640 trace_rpc_request(task);
1641
1642 /* Increment call count (version might not be valid for ping) */
1643 if (clnt->cl_program->version[clnt->cl_vers])
1644 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1645 clnt->cl_stats->rpccnt++;
1646 task->tk_action = call_reserve;
1647 rpc_task_set_transport(task, clnt);
1648 }
1649
1650 /*
1651 * 1. Reserve an RPC call slot
1652 */
1653 static void
call_reserve(struct rpc_task * task)1654 call_reserve(struct rpc_task *task)
1655 {
1656 task->tk_status = 0;
1657 task->tk_action = call_reserveresult;
1658 xprt_reserve(task);
1659 }
1660
1661 static void call_retry_reserve(struct rpc_task *task);
1662
1663 /*
1664 * 1b. Grok the result of xprt_reserve()
1665 */
1666 static void
call_reserveresult(struct rpc_task * task)1667 call_reserveresult(struct rpc_task *task)
1668 {
1669 int status = task->tk_status;
1670
1671 /*
1672 * After a call to xprt_reserve(), we must have either
1673 * a request slot or else an error status.
1674 */
1675 task->tk_status = 0;
1676 if (status >= 0) {
1677 if (task->tk_rqstp) {
1678 task->tk_action = call_refresh;
1679 return;
1680 }
1681
1682 rpc_call_rpcerror(task, -EIO);
1683 return;
1684 }
1685
1686 switch (status) {
1687 case -ENOMEM:
1688 rpc_delay(task, HZ >> 2);
1689 fallthrough;
1690 case -EAGAIN: /* woken up; retry */
1691 task->tk_action = call_retry_reserve;
1692 return;
1693 default:
1694 rpc_call_rpcerror(task, status);
1695 }
1696 }
1697
1698 /*
1699 * 1c. Retry reserving an RPC call slot
1700 */
1701 static void
call_retry_reserve(struct rpc_task * task)1702 call_retry_reserve(struct rpc_task *task)
1703 {
1704 task->tk_status = 0;
1705 task->tk_action = call_reserveresult;
1706 xprt_retry_reserve(task);
1707 }
1708
1709 /*
1710 * 2. Bind and/or refresh the credentials
1711 */
1712 static void
call_refresh(struct rpc_task * task)1713 call_refresh(struct rpc_task *task)
1714 {
1715 task->tk_action = call_refreshresult;
1716 task->tk_status = 0;
1717 task->tk_client->cl_stats->rpcauthrefresh++;
1718 rpcauth_refreshcred(task);
1719 }
1720
1721 /*
1722 * 2a. Process the results of a credential refresh
1723 */
1724 static void
call_refreshresult(struct rpc_task * task)1725 call_refreshresult(struct rpc_task *task)
1726 {
1727 int status = task->tk_status;
1728
1729 task->tk_status = 0;
1730 task->tk_action = call_refresh;
1731 switch (status) {
1732 case 0:
1733 if (rpcauth_uptodatecred(task)) {
1734 task->tk_action = call_allocate;
1735 return;
1736 }
1737 /* Use rate-limiting and a max number of retries if refresh
1738 * had status 0 but failed to update the cred.
1739 */
1740 fallthrough;
1741 case -ETIMEDOUT:
1742 rpc_delay(task, 3*HZ);
1743 fallthrough;
1744 case -EAGAIN:
1745 status = -EACCES;
1746 fallthrough;
1747 case -EKEYEXPIRED:
1748 if (!task->tk_cred_retry)
1749 break;
1750 task->tk_cred_retry--;
1751 trace_rpc_retry_refresh_status(task);
1752 return;
1753 }
1754 trace_rpc_refresh_status(task);
1755 rpc_call_rpcerror(task, status);
1756 }
1757
1758 /*
1759 * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc.
1760 * (Note: buffer memory is freed in xprt_release).
1761 */
1762 static void
call_allocate(struct rpc_task * task)1763 call_allocate(struct rpc_task *task)
1764 {
1765 const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1766 struct rpc_rqst *req = task->tk_rqstp;
1767 struct rpc_xprt *xprt = req->rq_xprt;
1768 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1769 int status;
1770
1771 task->tk_status = 0;
1772 task->tk_action = call_encode;
1773
1774 if (req->rq_buffer)
1775 return;
1776
1777 if (proc->p_proc != 0) {
1778 BUG_ON(proc->p_arglen == 0);
1779 if (proc->p_decode != NULL)
1780 BUG_ON(proc->p_replen == 0);
1781 }
1782
1783 /*
1784 * Calculate the size (in quads) of the RPC call
1785 * and reply headers, and convert both values
1786 * to byte sizes.
1787 */
1788 req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1789 proc->p_arglen;
1790 req->rq_callsize <<= 2;
1791 /*
1792 * Note: the reply buffer must at minimum allocate enough space
1793 * for the 'struct accepted_reply' from RFC5531.
1794 */
1795 req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1796 max_t(size_t, proc->p_replen, 2);
1797 req->rq_rcvsize <<= 2;
1798
1799 status = xprt->ops->buf_alloc(task);
1800 trace_rpc_buf_alloc(task, status);
1801 if (status == 0)
1802 return;
1803 if (status != -ENOMEM) {
1804 rpc_call_rpcerror(task, status);
1805 return;
1806 }
1807
1808 if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1809 task->tk_action = call_allocate;
1810 rpc_delay(task, HZ>>4);
1811 return;
1812 }
1813
1814 rpc_call_rpcerror(task, -ERESTARTSYS);
1815 }
1816
1817 static int
rpc_task_need_encode(struct rpc_task * task)1818 rpc_task_need_encode(struct rpc_task *task)
1819 {
1820 return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1821 (!(task->tk_flags & RPC_TASK_SENT) ||
1822 !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1823 xprt_request_need_retransmit(task));
1824 }
1825
1826 static void
rpc_xdr_encode(struct rpc_task * task)1827 rpc_xdr_encode(struct rpc_task *task)
1828 {
1829 struct rpc_rqst *req = task->tk_rqstp;
1830 struct xdr_stream xdr;
1831
1832 xdr_buf_init(&req->rq_snd_buf,
1833 req->rq_buffer,
1834 req->rq_callsize);
1835 xdr_buf_init(&req->rq_rcv_buf,
1836 req->rq_rbuffer,
1837 req->rq_rcvsize);
1838
1839 req->rq_reply_bytes_recvd = 0;
1840 req->rq_snd_buf.head[0].iov_len = 0;
1841 xdr_init_encode(&xdr, &req->rq_snd_buf,
1842 req->rq_snd_buf.head[0].iov_base, req);
1843 xdr_free_bvec(&req->rq_snd_buf);
1844 if (rpc_encode_header(task, &xdr))
1845 return;
1846
1847 task->tk_status = rpcauth_wrap_req(task, &xdr);
1848 }
1849
1850 /*
1851 * 3. Encode arguments of an RPC call
1852 */
1853 static void
call_encode(struct rpc_task * task)1854 call_encode(struct rpc_task *task)
1855 {
1856 if (!rpc_task_need_encode(task))
1857 goto out;
1858
1859 /* Dequeue task from the receive queue while we're encoding */
1860 xprt_request_dequeue_xprt(task);
1861 /* Encode here so that rpcsec_gss can use correct sequence number. */
1862 rpc_xdr_encode(task);
1863 /* Did the encode result in an error condition? */
1864 if (task->tk_status != 0) {
1865 /* Was the error nonfatal? */
1866 switch (task->tk_status) {
1867 case -EAGAIN:
1868 case -ENOMEM:
1869 rpc_delay(task, HZ >> 4);
1870 break;
1871 case -EKEYEXPIRED:
1872 if (!task->tk_cred_retry) {
1873 rpc_call_rpcerror(task, task->tk_status);
1874 } else {
1875 task->tk_action = call_refresh;
1876 task->tk_cred_retry--;
1877 trace_rpc_retry_refresh_status(task);
1878 }
1879 break;
1880 default:
1881 rpc_call_rpcerror(task, task->tk_status);
1882 }
1883 return;
1884 }
1885
1886 /* Add task to reply queue before transmission to avoid races */
1887 if (rpc_reply_expected(task))
1888 xprt_request_enqueue_receive(task);
1889 xprt_request_enqueue_transmit(task);
1890 out:
1891 task->tk_action = call_transmit;
1892 /* Check that the connection is OK */
1893 if (!xprt_bound(task->tk_xprt))
1894 task->tk_action = call_bind;
1895 else if (!xprt_connected(task->tk_xprt))
1896 task->tk_action = call_connect;
1897 }
1898
1899 /*
1900 * Helpers to check if the task was already transmitted, and
1901 * to take action when that is the case.
1902 */
1903 static bool
rpc_task_transmitted(struct rpc_task * task)1904 rpc_task_transmitted(struct rpc_task *task)
1905 {
1906 return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1907 }
1908
1909 static void
rpc_task_handle_transmitted(struct rpc_task * task)1910 rpc_task_handle_transmitted(struct rpc_task *task)
1911 {
1912 xprt_end_transmit(task);
1913 task->tk_action = call_transmit_status;
1914 }
1915
1916 /*
1917 * 4. Get the server port number if not yet set
1918 */
1919 static void
call_bind(struct rpc_task * task)1920 call_bind(struct rpc_task *task)
1921 {
1922 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1923
1924 if (rpc_task_transmitted(task)) {
1925 rpc_task_handle_transmitted(task);
1926 return;
1927 }
1928
1929 if (xprt_bound(xprt)) {
1930 task->tk_action = call_connect;
1931 return;
1932 }
1933
1934 task->tk_action = call_bind_status;
1935 if (!xprt_prepare_transmit(task))
1936 return;
1937
1938 xprt->ops->rpcbind(task);
1939 }
1940
1941 /*
1942 * 4a. Sort out bind result
1943 */
1944 static void
call_bind_status(struct rpc_task * task)1945 call_bind_status(struct rpc_task *task)
1946 {
1947 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1948 int status = -EIO;
1949
1950 if (rpc_task_transmitted(task)) {
1951 rpc_task_handle_transmitted(task);
1952 return;
1953 }
1954
1955 if (task->tk_status >= 0)
1956 goto out_next;
1957 if (xprt_bound(xprt)) {
1958 task->tk_status = 0;
1959 goto out_next;
1960 }
1961
1962 switch (task->tk_status) {
1963 case -ENOMEM:
1964 rpc_delay(task, HZ >> 2);
1965 goto retry_timeout;
1966 case -EACCES:
1967 trace_rpcb_prog_unavail_err(task);
1968 /* fail immediately if this is an RPC ping */
1969 if (task->tk_msg.rpc_proc->p_proc == 0) {
1970 status = -EOPNOTSUPP;
1971 break;
1972 }
1973 rpc_delay(task, 3*HZ);
1974 goto retry_timeout;
1975 case -ENOBUFS:
1976 rpc_delay(task, HZ >> 2);
1977 goto retry_timeout;
1978 case -EAGAIN:
1979 goto retry_timeout;
1980 case -ETIMEDOUT:
1981 trace_rpcb_timeout_err(task);
1982 goto retry_timeout;
1983 case -EPFNOSUPPORT:
1984 /* server doesn't support any rpcbind version we know of */
1985 trace_rpcb_bind_version_err(task);
1986 break;
1987 case -EPROTONOSUPPORT:
1988 trace_rpcb_bind_version_err(task);
1989 goto retry_timeout;
1990 case -ECONNREFUSED: /* connection problems */
1991 case -ECONNRESET:
1992 case -ECONNABORTED:
1993 case -ENOTCONN:
1994 case -EHOSTDOWN:
1995 case -ENETDOWN:
1996 case -EHOSTUNREACH:
1997 case -ENETUNREACH:
1998 case -EPIPE:
1999 trace_rpcb_unreachable_err(task);
2000 if (!RPC_IS_SOFTCONN(task)) {
2001 rpc_delay(task, 5*HZ);
2002 goto retry_timeout;
2003 }
2004 status = task->tk_status;
2005 break;
2006 default:
2007 trace_rpcb_unrecognized_err(task);
2008 }
2009
2010 rpc_call_rpcerror(task, status);
2011 return;
2012 out_next:
2013 task->tk_action = call_connect;
2014 return;
2015 retry_timeout:
2016 task->tk_status = 0;
2017 task->tk_action = call_bind;
2018 rpc_check_timeout(task);
2019 }
2020
2021 /*
2022 * 4b. Connect to the RPC server
2023 */
2024 static void
call_connect(struct rpc_task * task)2025 call_connect(struct rpc_task *task)
2026 {
2027 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2028
2029 if (rpc_task_transmitted(task)) {
2030 rpc_task_handle_transmitted(task);
2031 return;
2032 }
2033
2034 if (xprt_connected(xprt)) {
2035 task->tk_action = call_transmit;
2036 return;
2037 }
2038
2039 task->tk_action = call_connect_status;
2040 if (task->tk_status < 0)
2041 return;
2042 if (task->tk_flags & RPC_TASK_NOCONNECT) {
2043 rpc_call_rpcerror(task, -ENOTCONN);
2044 return;
2045 }
2046 if (!xprt_prepare_transmit(task))
2047 return;
2048 xprt_connect(task);
2049 }
2050
2051 /*
2052 * 4c. Sort out connect result
2053 */
2054 static void
call_connect_status(struct rpc_task * task)2055 call_connect_status(struct rpc_task *task)
2056 {
2057 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2058 struct rpc_clnt *clnt = task->tk_client;
2059 int status = task->tk_status;
2060
2061 if (rpc_task_transmitted(task)) {
2062 rpc_task_handle_transmitted(task);
2063 return;
2064 }
2065
2066 trace_rpc_connect_status(task);
2067
2068 if (task->tk_status == 0) {
2069 clnt->cl_stats->netreconn++;
2070 goto out_next;
2071 }
2072 if (xprt_connected(xprt)) {
2073 task->tk_status = 0;
2074 goto out_next;
2075 }
2076
2077 task->tk_status = 0;
2078 switch (status) {
2079 case -ECONNREFUSED:
2080 case -ECONNRESET:
2081 /* A positive refusal suggests a rebind is needed. */
2082 if (RPC_IS_SOFTCONN(task))
2083 break;
2084 if (clnt->cl_autobind) {
2085 rpc_force_rebind(clnt);
2086 goto out_retry;
2087 }
2088 fallthrough;
2089 case -ECONNABORTED:
2090 case -ENETDOWN:
2091 case -ENETUNREACH:
2092 case -EHOSTUNREACH:
2093 case -EPIPE:
2094 case -EPROTO:
2095 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2096 task->tk_rqstp->rq_connect_cookie);
2097 if (RPC_IS_SOFTCONN(task))
2098 break;
2099 /* retry with existing socket, after a delay */
2100 rpc_delay(task, 3*HZ);
2101 fallthrough;
2102 case -EADDRINUSE:
2103 case -ENOTCONN:
2104 case -EAGAIN:
2105 case -ETIMEDOUT:
2106 goto out_retry;
2107 case -ENOBUFS:
2108 rpc_delay(task, HZ >> 2);
2109 goto out_retry;
2110 }
2111 rpc_call_rpcerror(task, status);
2112 return;
2113 out_next:
2114 task->tk_action = call_transmit;
2115 return;
2116 out_retry:
2117 /* Check for timeouts before looping back to call_bind */
2118 task->tk_action = call_bind;
2119 rpc_check_timeout(task);
2120 }
2121
2122 /*
2123 * 5. Transmit the RPC request, and wait for reply
2124 */
2125 static void
call_transmit(struct rpc_task * task)2126 call_transmit(struct rpc_task *task)
2127 {
2128 if (rpc_task_transmitted(task)) {
2129 rpc_task_handle_transmitted(task);
2130 return;
2131 }
2132
2133 task->tk_action = call_transmit_status;
2134 if (!xprt_prepare_transmit(task))
2135 return;
2136 task->tk_status = 0;
2137 if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2138 if (!xprt_connected(task->tk_xprt)) {
2139 task->tk_status = -ENOTCONN;
2140 return;
2141 }
2142 xprt_transmit(task);
2143 }
2144 xprt_end_transmit(task);
2145 }
2146
2147 /*
2148 * 5a. Handle cleanup after a transmission
2149 */
2150 static void
call_transmit_status(struct rpc_task * task)2151 call_transmit_status(struct rpc_task *task)
2152 {
2153 task->tk_action = call_status;
2154
2155 /*
2156 * Common case: success. Force the compiler to put this
2157 * test first.
2158 */
2159 if (rpc_task_transmitted(task)) {
2160 task->tk_status = 0;
2161 xprt_request_wait_receive(task);
2162 return;
2163 }
2164
2165 switch (task->tk_status) {
2166 default:
2167 break;
2168 case -EBADMSG:
2169 task->tk_status = 0;
2170 task->tk_action = call_encode;
2171 break;
2172 /*
2173 * Special cases: if we've been waiting on the
2174 * socket's write_space() callback, or if the
2175 * socket just returned a connection error,
2176 * then hold onto the transport lock.
2177 */
2178 case -ENOMEM:
2179 case -ENOBUFS:
2180 rpc_delay(task, HZ>>2);
2181 fallthrough;
2182 case -EBADSLT:
2183 case -EAGAIN:
2184 task->tk_action = call_transmit;
2185 task->tk_status = 0;
2186 break;
2187 case -ECONNREFUSED:
2188 case -EHOSTDOWN:
2189 case -ENETDOWN:
2190 case -EHOSTUNREACH:
2191 case -ENETUNREACH:
2192 case -EPERM:
2193 if (RPC_IS_SOFTCONN(task)) {
2194 if (!task->tk_msg.rpc_proc->p_proc)
2195 trace_xprt_ping(task->tk_xprt,
2196 task->tk_status);
2197 rpc_call_rpcerror(task, task->tk_status);
2198 return;
2199 }
2200 fallthrough;
2201 case -ECONNRESET:
2202 case -ECONNABORTED:
2203 case -EADDRINUSE:
2204 case -ENOTCONN:
2205 case -EPIPE:
2206 task->tk_action = call_bind;
2207 task->tk_status = 0;
2208 break;
2209 }
2210 rpc_check_timeout(task);
2211 }
2212
2213 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2214 static void call_bc_transmit(struct rpc_task *task);
2215 static void call_bc_transmit_status(struct rpc_task *task);
2216
2217 static void
call_bc_encode(struct rpc_task * task)2218 call_bc_encode(struct rpc_task *task)
2219 {
2220 xprt_request_enqueue_transmit(task);
2221 task->tk_action = call_bc_transmit;
2222 }
2223
2224 /*
2225 * 5b. Send the backchannel RPC reply. On error, drop the reply. In
2226 * addition, disconnect on connectivity errors.
2227 */
2228 static void
call_bc_transmit(struct rpc_task * task)2229 call_bc_transmit(struct rpc_task *task)
2230 {
2231 task->tk_action = call_bc_transmit_status;
2232 if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2233 if (!xprt_prepare_transmit(task))
2234 return;
2235 task->tk_status = 0;
2236 xprt_transmit(task);
2237 }
2238 xprt_end_transmit(task);
2239 }
2240
2241 static void
call_bc_transmit_status(struct rpc_task * task)2242 call_bc_transmit_status(struct rpc_task *task)
2243 {
2244 struct rpc_rqst *req = task->tk_rqstp;
2245
2246 if (rpc_task_transmitted(task))
2247 task->tk_status = 0;
2248
2249 switch (task->tk_status) {
2250 case 0:
2251 /* Success */
2252 case -ENETDOWN:
2253 case -EHOSTDOWN:
2254 case -EHOSTUNREACH:
2255 case -ENETUNREACH:
2256 case -ECONNRESET:
2257 case -ECONNREFUSED:
2258 case -EADDRINUSE:
2259 case -ENOTCONN:
2260 case -EPIPE:
2261 break;
2262 case -ENOMEM:
2263 case -ENOBUFS:
2264 rpc_delay(task, HZ>>2);
2265 fallthrough;
2266 case -EBADSLT:
2267 case -EAGAIN:
2268 task->tk_status = 0;
2269 task->tk_action = call_bc_transmit;
2270 return;
2271 case -ETIMEDOUT:
2272 /*
2273 * Problem reaching the server. Disconnect and let the
2274 * forechannel reestablish the connection. The server will
2275 * have to retransmit the backchannel request and we'll
2276 * reprocess it. Since these ops are idempotent, there's no
2277 * need to cache our reply at this time.
2278 */
2279 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2280 "error: %d\n", task->tk_status);
2281 xprt_conditional_disconnect(req->rq_xprt,
2282 req->rq_connect_cookie);
2283 break;
2284 default:
2285 /*
2286 * We were unable to reply and will have to drop the
2287 * request. The server should reconnect and retransmit.
2288 */
2289 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2290 "error: %d\n", task->tk_status);
2291 break;
2292 }
2293 task->tk_action = rpc_exit_task;
2294 }
2295 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2296
2297 /*
2298 * 6. Sort out the RPC call status
2299 */
2300 static void
call_status(struct rpc_task * task)2301 call_status(struct rpc_task *task)
2302 {
2303 struct rpc_clnt *clnt = task->tk_client;
2304 int status;
2305
2306 if (!task->tk_msg.rpc_proc->p_proc)
2307 trace_xprt_ping(task->tk_xprt, task->tk_status);
2308
2309 status = task->tk_status;
2310 if (status >= 0) {
2311 task->tk_action = call_decode;
2312 return;
2313 }
2314
2315 trace_rpc_call_status(task);
2316 task->tk_status = 0;
2317 switch(status) {
2318 case -EHOSTDOWN:
2319 case -ENETDOWN:
2320 case -EHOSTUNREACH:
2321 case -ENETUNREACH:
2322 case -EPERM:
2323 if (RPC_IS_SOFTCONN(task))
2324 goto out_exit;
2325 /*
2326 * Delay any retries for 3 seconds, then handle as if it
2327 * were a timeout.
2328 */
2329 rpc_delay(task, 3*HZ);
2330 fallthrough;
2331 case -ETIMEDOUT:
2332 break;
2333 case -ECONNREFUSED:
2334 case -ECONNRESET:
2335 case -ECONNABORTED:
2336 case -ENOTCONN:
2337 rpc_force_rebind(clnt);
2338 break;
2339 case -EADDRINUSE:
2340 rpc_delay(task, 3*HZ);
2341 fallthrough;
2342 case -EPIPE:
2343 case -EAGAIN:
2344 break;
2345 case -ENFILE:
2346 case -ENOBUFS:
2347 case -ENOMEM:
2348 rpc_delay(task, HZ>>2);
2349 break;
2350 case -EIO:
2351 /* shutdown or soft timeout */
2352 goto out_exit;
2353 default:
2354 if (clnt->cl_chatty)
2355 printk("%s: RPC call returned error %d\n",
2356 clnt->cl_program->name, -status);
2357 goto out_exit;
2358 }
2359 task->tk_action = call_encode;
2360 rpc_check_timeout(task);
2361 return;
2362 out_exit:
2363 rpc_call_rpcerror(task, status);
2364 }
2365
2366 static bool
rpc_check_connected(const struct rpc_rqst * req)2367 rpc_check_connected(const struct rpc_rqst *req)
2368 {
2369 /* No allocated request or transport? return true */
2370 if (!req || !req->rq_xprt)
2371 return true;
2372 return xprt_connected(req->rq_xprt);
2373 }
2374
2375 static void
rpc_check_timeout(struct rpc_task * task)2376 rpc_check_timeout(struct rpc_task *task)
2377 {
2378 struct rpc_clnt *clnt = task->tk_client;
2379
2380 if (RPC_SIGNALLED(task)) {
2381 rpc_call_rpcerror(task, -ERESTARTSYS);
2382 return;
2383 }
2384
2385 if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2386 return;
2387
2388 trace_rpc_timeout_status(task);
2389 task->tk_timeouts++;
2390
2391 if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2392 rpc_call_rpcerror(task, -ETIMEDOUT);
2393 return;
2394 }
2395
2396 if (RPC_IS_SOFT(task)) {
2397 /*
2398 * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2399 * been sent, it should time out only if the transport
2400 * connection gets terminally broken.
2401 */
2402 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2403 rpc_check_connected(task->tk_rqstp))
2404 return;
2405
2406 if (clnt->cl_chatty) {
2407 pr_notice_ratelimited(
2408 "%s: server %s not responding, timed out\n",
2409 clnt->cl_program->name,
2410 task->tk_xprt->servername);
2411 }
2412 if (task->tk_flags & RPC_TASK_TIMEOUT)
2413 rpc_call_rpcerror(task, -ETIMEDOUT);
2414 else
2415 __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2416 return;
2417 }
2418
2419 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2420 task->tk_flags |= RPC_CALL_MAJORSEEN;
2421 if (clnt->cl_chatty) {
2422 pr_notice_ratelimited(
2423 "%s: server %s not responding, still trying\n",
2424 clnt->cl_program->name,
2425 task->tk_xprt->servername);
2426 }
2427 }
2428 rpc_force_rebind(clnt);
2429 /*
2430 * Did our request time out due to an RPCSEC_GSS out-of-sequence
2431 * event? RFC2203 requires the server to drop all such requests.
2432 */
2433 rpcauth_invalcred(task);
2434 }
2435
2436 /*
2437 * 7. Decode the RPC reply
2438 */
2439 static void
call_decode(struct rpc_task * task)2440 call_decode(struct rpc_task *task)
2441 {
2442 struct rpc_clnt *clnt = task->tk_client;
2443 struct rpc_rqst *req = task->tk_rqstp;
2444 struct xdr_stream xdr;
2445 int err;
2446
2447 if (!task->tk_msg.rpc_proc->p_decode) {
2448 task->tk_action = rpc_exit_task;
2449 return;
2450 }
2451
2452 if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2453 if (clnt->cl_chatty) {
2454 pr_notice_ratelimited("%s: server %s OK\n",
2455 clnt->cl_program->name,
2456 task->tk_xprt->servername);
2457 }
2458 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2459 }
2460
2461 /*
2462 * Did we ever call xprt_complete_rqst()? If not, we should assume
2463 * the message is incomplete.
2464 */
2465 err = -EAGAIN;
2466 if (!req->rq_reply_bytes_recvd)
2467 goto out;
2468
2469 /* Ensure that we see all writes made by xprt_complete_rqst()
2470 * before it changed req->rq_reply_bytes_recvd.
2471 */
2472 smp_rmb();
2473
2474 req->rq_rcv_buf.len = req->rq_private_buf.len;
2475 trace_rpc_xdr_recvfrom(task, &req->rq_rcv_buf);
2476
2477 /* Check that the softirq receive buffer is valid */
2478 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2479 sizeof(req->rq_rcv_buf)) != 0);
2480
2481 xdr_init_decode(&xdr, &req->rq_rcv_buf,
2482 req->rq_rcv_buf.head[0].iov_base, req);
2483 err = rpc_decode_header(task, &xdr);
2484 out:
2485 switch (err) {
2486 case 0:
2487 task->tk_action = rpc_exit_task;
2488 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2489 return;
2490 case -EAGAIN:
2491 task->tk_status = 0;
2492 if (task->tk_client->cl_discrtry)
2493 xprt_conditional_disconnect(req->rq_xprt,
2494 req->rq_connect_cookie);
2495 task->tk_action = call_encode;
2496 rpc_check_timeout(task);
2497 break;
2498 case -EKEYREJECTED:
2499 task->tk_action = call_reserve;
2500 rpc_check_timeout(task);
2501 rpcauth_invalcred(task);
2502 /* Ensure we obtain a new XID if we retry! */
2503 xprt_release(task);
2504 }
2505 }
2506
2507 static int
rpc_encode_header(struct rpc_task * task,struct xdr_stream * xdr)2508 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2509 {
2510 struct rpc_clnt *clnt = task->tk_client;
2511 struct rpc_rqst *req = task->tk_rqstp;
2512 __be32 *p;
2513 int error;
2514
2515 error = -EMSGSIZE;
2516 p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2517 if (!p)
2518 goto out_fail;
2519 *p++ = req->rq_xid;
2520 *p++ = rpc_call;
2521 *p++ = cpu_to_be32(RPC_VERSION);
2522 *p++ = cpu_to_be32(clnt->cl_prog);
2523 *p++ = cpu_to_be32(clnt->cl_vers);
2524 *p = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2525
2526 error = rpcauth_marshcred(task, xdr);
2527 if (error < 0)
2528 goto out_fail;
2529 return 0;
2530 out_fail:
2531 trace_rpc_bad_callhdr(task);
2532 rpc_call_rpcerror(task, error);
2533 return error;
2534 }
2535
2536 static noinline int
rpc_decode_header(struct rpc_task * task,struct xdr_stream * xdr)2537 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2538 {
2539 struct rpc_clnt *clnt = task->tk_client;
2540 int error;
2541 __be32 *p;
2542
2543 /* RFC-1014 says that the representation of XDR data must be a
2544 * multiple of four bytes
2545 * - if it isn't pointer subtraction in the NFS client may give
2546 * undefined results
2547 */
2548 if (task->tk_rqstp->rq_rcv_buf.len & 3)
2549 goto out_unparsable;
2550
2551 p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2552 if (!p)
2553 goto out_unparsable;
2554 p++; /* skip XID */
2555 if (*p++ != rpc_reply)
2556 goto out_unparsable;
2557 if (*p++ != rpc_msg_accepted)
2558 goto out_msg_denied;
2559
2560 error = rpcauth_checkverf(task, xdr);
2561 if (error)
2562 goto out_verifier;
2563
2564 p = xdr_inline_decode(xdr, sizeof(*p));
2565 if (!p)
2566 goto out_unparsable;
2567 switch (*p) {
2568 case rpc_success:
2569 return 0;
2570 case rpc_prog_unavail:
2571 trace_rpc__prog_unavail(task);
2572 error = -EPFNOSUPPORT;
2573 goto out_err;
2574 case rpc_prog_mismatch:
2575 trace_rpc__prog_mismatch(task);
2576 error = -EPROTONOSUPPORT;
2577 goto out_err;
2578 case rpc_proc_unavail:
2579 trace_rpc__proc_unavail(task);
2580 error = -EOPNOTSUPP;
2581 goto out_err;
2582 case rpc_garbage_args:
2583 case rpc_system_err:
2584 trace_rpc__garbage_args(task);
2585 error = -EIO;
2586 break;
2587 default:
2588 goto out_unparsable;
2589 }
2590
2591 out_garbage:
2592 clnt->cl_stats->rpcgarbage++;
2593 if (task->tk_garb_retry) {
2594 task->tk_garb_retry--;
2595 task->tk_action = call_encode;
2596 return -EAGAIN;
2597 }
2598 out_err:
2599 rpc_call_rpcerror(task, error);
2600 return error;
2601
2602 out_unparsable:
2603 trace_rpc__unparsable(task);
2604 error = -EIO;
2605 goto out_garbage;
2606
2607 out_verifier:
2608 trace_rpc_bad_verifier(task);
2609 goto out_garbage;
2610
2611 out_msg_denied:
2612 error = -EACCES;
2613 p = xdr_inline_decode(xdr, sizeof(*p));
2614 if (!p)
2615 goto out_unparsable;
2616 switch (*p++) {
2617 case rpc_auth_error:
2618 break;
2619 case rpc_mismatch:
2620 trace_rpc__mismatch(task);
2621 error = -EPROTONOSUPPORT;
2622 goto out_err;
2623 default:
2624 goto out_unparsable;
2625 }
2626
2627 p = xdr_inline_decode(xdr, sizeof(*p));
2628 if (!p)
2629 goto out_unparsable;
2630 switch (*p++) {
2631 case rpc_autherr_rejectedcred:
2632 case rpc_autherr_rejectedverf:
2633 case rpcsec_gsserr_credproblem:
2634 case rpcsec_gsserr_ctxproblem:
2635 rpcauth_invalcred(task);
2636 if (!task->tk_cred_retry)
2637 break;
2638 task->tk_cred_retry--;
2639 trace_rpc__stale_creds(task);
2640 return -EKEYREJECTED;
2641 case rpc_autherr_badcred:
2642 case rpc_autherr_badverf:
2643 /* possibly garbled cred/verf? */
2644 if (!task->tk_garb_retry)
2645 break;
2646 task->tk_garb_retry--;
2647 trace_rpc__bad_creds(task);
2648 task->tk_action = call_encode;
2649 return -EAGAIN;
2650 case rpc_autherr_tooweak:
2651 trace_rpc__auth_tooweak(task);
2652 pr_warn("RPC: server %s requires stronger authentication.\n",
2653 task->tk_xprt->servername);
2654 break;
2655 default:
2656 goto out_unparsable;
2657 }
2658 goto out_err;
2659 }
2660
rpcproc_encode_null(struct rpc_rqst * rqstp,struct xdr_stream * xdr,const void * obj)2661 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2662 const void *obj)
2663 {
2664 }
2665
rpcproc_decode_null(struct rpc_rqst * rqstp,struct xdr_stream * xdr,void * obj)2666 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2667 void *obj)
2668 {
2669 return 0;
2670 }
2671
2672 static const struct rpc_procinfo rpcproc_null = {
2673 .p_encode = rpcproc_encode_null,
2674 .p_decode = rpcproc_decode_null,
2675 };
2676
rpc_ping(struct rpc_clnt * clnt)2677 static int rpc_ping(struct rpc_clnt *clnt)
2678 {
2679 struct rpc_message msg = {
2680 .rpc_proc = &rpcproc_null,
2681 };
2682 int err;
2683 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2684 RPC_TASK_NULLCREDS);
2685 return err;
2686 }
2687
2688 static
rpc_call_null_helper(struct rpc_clnt * clnt,struct rpc_xprt * xprt,struct rpc_cred * cred,int flags,const struct rpc_call_ops * ops,void * data)2689 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2690 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2691 const struct rpc_call_ops *ops, void *data)
2692 {
2693 struct rpc_message msg = {
2694 .rpc_proc = &rpcproc_null,
2695 };
2696 struct rpc_task_setup task_setup_data = {
2697 .rpc_client = clnt,
2698 .rpc_xprt = xprt,
2699 .rpc_message = &msg,
2700 .rpc_op_cred = cred,
2701 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2702 .callback_data = data,
2703 .flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2704 RPC_TASK_NULLCREDS,
2705 };
2706
2707 return rpc_run_task(&task_setup_data);
2708 }
2709
rpc_call_null(struct rpc_clnt * clnt,struct rpc_cred * cred,int flags)2710 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2711 {
2712 return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2713 }
2714 EXPORT_SYMBOL_GPL(rpc_call_null);
2715
2716 struct rpc_cb_add_xprt_calldata {
2717 struct rpc_xprt_switch *xps;
2718 struct rpc_xprt *xprt;
2719 };
2720
rpc_cb_add_xprt_done(struct rpc_task * task,void * calldata)2721 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2722 {
2723 struct rpc_cb_add_xprt_calldata *data = calldata;
2724
2725 if (task->tk_status == 0)
2726 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2727 }
2728
rpc_cb_add_xprt_release(void * calldata)2729 static void rpc_cb_add_xprt_release(void *calldata)
2730 {
2731 struct rpc_cb_add_xprt_calldata *data = calldata;
2732
2733 xprt_put(data->xprt);
2734 xprt_switch_put(data->xps);
2735 kfree(data);
2736 }
2737
2738 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2739 .rpc_call_done = rpc_cb_add_xprt_done,
2740 .rpc_release = rpc_cb_add_xprt_release,
2741 };
2742
2743 /**
2744 * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2745 * @clnt: pointer to struct rpc_clnt
2746 * @xps: pointer to struct rpc_xprt_switch,
2747 * @xprt: pointer struct rpc_xprt
2748 * @dummy: unused
2749 */
rpc_clnt_test_and_add_xprt(struct rpc_clnt * clnt,struct rpc_xprt_switch * xps,struct rpc_xprt * xprt,void * dummy)2750 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2751 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2752 void *dummy)
2753 {
2754 struct rpc_cb_add_xprt_calldata *data;
2755 struct rpc_task *task;
2756
2757 data = kmalloc(sizeof(*data), GFP_NOFS);
2758 if (!data)
2759 return -ENOMEM;
2760 data->xps = xprt_switch_get(xps);
2761 data->xprt = xprt_get(xprt);
2762 if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2763 rpc_cb_add_xprt_release(data);
2764 goto success;
2765 }
2766
2767 task = rpc_call_null_helper(clnt, xprt, NULL, RPC_TASK_ASYNC,
2768 &rpc_cb_add_xprt_call_ops, data);
2769
2770 rpc_put_task(task);
2771 success:
2772 return 1;
2773 }
2774 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2775
2776 /**
2777 * rpc_clnt_setup_test_and_add_xprt()
2778 *
2779 * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2780 * 1) caller of the test function must dereference the rpc_xprt_switch
2781 * and the rpc_xprt.
2782 * 2) test function must call rpc_xprt_switch_add_xprt, usually in
2783 * the rpc_call_done routine.
2784 *
2785 * Upon success (return of 1), the test function adds the new
2786 * transport to the rpc_clnt xprt switch
2787 *
2788 * @clnt: struct rpc_clnt to get the new transport
2789 * @xps: the rpc_xprt_switch to hold the new transport
2790 * @xprt: the rpc_xprt to test
2791 * @data: a struct rpc_add_xprt_test pointer that holds the test function
2792 * and test function call data
2793 */
rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt * clnt,struct rpc_xprt_switch * xps,struct rpc_xprt * xprt,void * data)2794 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2795 struct rpc_xprt_switch *xps,
2796 struct rpc_xprt *xprt,
2797 void *data)
2798 {
2799 struct rpc_task *task;
2800 struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2801 int status = -EADDRINUSE;
2802
2803 xprt = xprt_get(xprt);
2804 xprt_switch_get(xps);
2805
2806 if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2807 goto out_err;
2808
2809 /* Test the connection */
2810 task = rpc_call_null_helper(clnt, xprt, NULL, 0, NULL, NULL);
2811 if (IS_ERR(task)) {
2812 status = PTR_ERR(task);
2813 goto out_err;
2814 }
2815 status = task->tk_status;
2816 rpc_put_task(task);
2817
2818 if (status < 0)
2819 goto out_err;
2820
2821 /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2822 xtest->add_xprt_test(clnt, xprt, xtest->data);
2823
2824 xprt_put(xprt);
2825 xprt_switch_put(xps);
2826
2827 /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2828 return 1;
2829 out_err:
2830 xprt_put(xprt);
2831 xprt_switch_put(xps);
2832 pr_info("RPC: rpc_clnt_test_xprt failed: %d addr %s not added\n",
2833 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2834 return status;
2835 }
2836 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2837
2838 /**
2839 * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2840 * @clnt: pointer to struct rpc_clnt
2841 * @xprtargs: pointer to struct xprt_create
2842 * @setup: callback to test and/or set up the connection
2843 * @data: pointer to setup function data
2844 *
2845 * Creates a new transport using the parameters set in args and
2846 * adds it to clnt.
2847 * If ping is set, then test that connectivity succeeds before
2848 * adding the new transport.
2849 *
2850 */
rpc_clnt_add_xprt(struct rpc_clnt * clnt,struct xprt_create * xprtargs,int (* setup)(struct rpc_clnt *,struct rpc_xprt_switch *,struct rpc_xprt *,void *),void * data)2851 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2852 struct xprt_create *xprtargs,
2853 int (*setup)(struct rpc_clnt *,
2854 struct rpc_xprt_switch *,
2855 struct rpc_xprt *,
2856 void *),
2857 void *data)
2858 {
2859 struct rpc_xprt_switch *xps;
2860 struct rpc_xprt *xprt;
2861 unsigned long connect_timeout;
2862 unsigned long reconnect_timeout;
2863 unsigned char resvport, reuseport;
2864 int ret = 0;
2865
2866 rcu_read_lock();
2867 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2868 xprt = xprt_iter_xprt(&clnt->cl_xpi);
2869 if (xps == NULL || xprt == NULL) {
2870 rcu_read_unlock();
2871 xprt_switch_put(xps);
2872 return -EAGAIN;
2873 }
2874 resvport = xprt->resvport;
2875 reuseport = xprt->reuseport;
2876 connect_timeout = xprt->connect_timeout;
2877 reconnect_timeout = xprt->max_reconnect_timeout;
2878 rcu_read_unlock();
2879
2880 xprt = xprt_create_transport(xprtargs);
2881 if (IS_ERR(xprt)) {
2882 ret = PTR_ERR(xprt);
2883 goto out_put_switch;
2884 }
2885 xprt->resvport = resvport;
2886 xprt->reuseport = reuseport;
2887 if (xprt->ops->set_connect_timeout != NULL)
2888 xprt->ops->set_connect_timeout(xprt,
2889 connect_timeout,
2890 reconnect_timeout);
2891
2892 rpc_xprt_switch_set_roundrobin(xps);
2893 if (setup) {
2894 ret = setup(clnt, xps, xprt, data);
2895 if (ret != 0)
2896 goto out_put_xprt;
2897 }
2898 rpc_xprt_switch_add_xprt(xps, xprt);
2899 out_put_xprt:
2900 xprt_put(xprt);
2901 out_put_switch:
2902 xprt_switch_put(xps);
2903 return ret;
2904 }
2905 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2906
2907 struct connect_timeout_data {
2908 unsigned long connect_timeout;
2909 unsigned long reconnect_timeout;
2910 };
2911
2912 static int
rpc_xprt_set_connect_timeout(struct rpc_clnt * clnt,struct rpc_xprt * xprt,void * data)2913 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2914 struct rpc_xprt *xprt,
2915 void *data)
2916 {
2917 struct connect_timeout_data *timeo = data;
2918
2919 if (xprt->ops->set_connect_timeout)
2920 xprt->ops->set_connect_timeout(xprt,
2921 timeo->connect_timeout,
2922 timeo->reconnect_timeout);
2923 return 0;
2924 }
2925
2926 void
rpc_set_connect_timeout(struct rpc_clnt * clnt,unsigned long connect_timeout,unsigned long reconnect_timeout)2927 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2928 unsigned long connect_timeout,
2929 unsigned long reconnect_timeout)
2930 {
2931 struct connect_timeout_data timeout = {
2932 .connect_timeout = connect_timeout,
2933 .reconnect_timeout = reconnect_timeout,
2934 };
2935 rpc_clnt_iterate_for_each_xprt(clnt,
2936 rpc_xprt_set_connect_timeout,
2937 &timeout);
2938 }
2939 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2940
rpc_clnt_xprt_switch_put(struct rpc_clnt * clnt)2941 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2942 {
2943 rcu_read_lock();
2944 xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2945 rcu_read_unlock();
2946 }
2947 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2948
rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt * clnt,struct rpc_xprt * xprt)2949 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2950 {
2951 rcu_read_lock();
2952 rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2953 xprt);
2954 rcu_read_unlock();
2955 }
2956 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2957
rpc_clnt_xprt_switch_has_addr(struct rpc_clnt * clnt,const struct sockaddr * sap)2958 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2959 const struct sockaddr *sap)
2960 {
2961 struct rpc_xprt_switch *xps;
2962 bool ret;
2963
2964 rcu_read_lock();
2965 xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2966 ret = rpc_xprt_switch_has_addr(xps, sap);
2967 rcu_read_unlock();
2968 return ret;
2969 }
2970 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2971
2972 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
rpc_show_header(void)2973 static void rpc_show_header(void)
2974 {
2975 printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2976 "-timeout ---ops--\n");
2977 }
2978
rpc_show_task(const struct rpc_clnt * clnt,const struct rpc_task * task)2979 static void rpc_show_task(const struct rpc_clnt *clnt,
2980 const struct rpc_task *task)
2981 {
2982 const char *rpc_waitq = "none";
2983
2984 if (RPC_IS_QUEUED(task))
2985 rpc_waitq = rpc_qname(task->tk_waitqueue);
2986
2987 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2988 task->tk_pid, task->tk_flags, task->tk_status,
2989 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
2990 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2991 task->tk_action, rpc_waitq);
2992 }
2993
rpc_show_tasks(struct net * net)2994 void rpc_show_tasks(struct net *net)
2995 {
2996 struct rpc_clnt *clnt;
2997 struct rpc_task *task;
2998 int header = 0;
2999 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3000
3001 spin_lock(&sn->rpc_client_lock);
3002 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3003 spin_lock(&clnt->cl_lock);
3004 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3005 if (!header) {
3006 rpc_show_header();
3007 header++;
3008 }
3009 rpc_show_task(clnt, task);
3010 }
3011 spin_unlock(&clnt->cl_lock);
3012 }
3013 spin_unlock(&sn->rpc_client_lock);
3014 }
3015 #endif
3016
3017 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3018 static int
rpc_clnt_swap_activate_callback(struct rpc_clnt * clnt,struct rpc_xprt * xprt,void * dummy)3019 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3020 struct rpc_xprt *xprt,
3021 void *dummy)
3022 {
3023 return xprt_enable_swap(xprt);
3024 }
3025
3026 int
rpc_clnt_swap_activate(struct rpc_clnt * clnt)3027 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3028 {
3029 while (clnt != clnt->cl_parent)
3030 clnt = clnt->cl_parent;
3031 if (atomic_inc_return(&clnt->cl_swapper) == 1)
3032 return rpc_clnt_iterate_for_each_xprt(clnt,
3033 rpc_clnt_swap_activate_callback, NULL);
3034 return 0;
3035 }
3036 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3037
3038 static int
rpc_clnt_swap_deactivate_callback(struct rpc_clnt * clnt,struct rpc_xprt * xprt,void * dummy)3039 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3040 struct rpc_xprt *xprt,
3041 void *dummy)
3042 {
3043 xprt_disable_swap(xprt);
3044 return 0;
3045 }
3046
3047 void
rpc_clnt_swap_deactivate(struct rpc_clnt * clnt)3048 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3049 {
3050 while (clnt != clnt->cl_parent)
3051 clnt = clnt->cl_parent;
3052 if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3053 rpc_clnt_iterate_for_each_xprt(clnt,
3054 rpc_clnt_swap_deactivate_callback, NULL);
3055 }
3056 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3057 #endif /* CONFIG_SUNRPC_SWAP */
3058