/net/sunrpc/clnt.c
C | 1795 lines | 1325 code | 184 blank | 286 comment | 187 complexity | 11c028f4c70adb357fb049522f70eba8 MD5 | raw file
Possible License(s): CC-BY-SA-3.0, GPL-2.0, LGPL-2.0, AGPL-1.0
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 * NB: BSD uses a more intelligent approach to guessing when a request
17 * or reply has been lost by keeping the RTO estimate for each procedure.
18 * We currently make do with a constant timeout value.
19 *
20 * Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
21 * Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
22 */
23
24#include <asm/system.h>
25
26#include <linux/module.h>
27#include <linux/types.h>
28#include <linux/kallsyms.h>
29#include <linux/mm.h>
30#include <linux/namei.h>
31#include <linux/mount.h>
32#include <linux/slab.h>
33#include <linux/utsname.h>
34#include <linux/workqueue.h>
35#include <linux/in6.h>
36
37#include <linux/sunrpc/clnt.h>
38#include <linux/sunrpc/rpc_pipe_fs.h>
39#include <linux/sunrpc/metrics.h>
40#include <linux/sunrpc/bc_xprt.h>
41
42#include "sunrpc.h"
43
44#ifdef RPC_DEBUG
45# define RPCDBG_FACILITY RPCDBG_CALL
46#endif
47
48#define dprint_status(t) \
49 dprintk("RPC: %5u %s (status %d)\n", t->tk_pid, \
50 __func__, t->tk_status)
51
52/*
53 * All RPC clients are linked into this list
54 */
55static LIST_HEAD(all_clients);
56static DEFINE_SPINLOCK(rpc_client_lock);
57
58static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
59
60
61static void call_start(struct rpc_task *task);
62static void call_reserve(struct rpc_task *task);
63static void call_reserveresult(struct rpc_task *task);
64static void call_allocate(struct rpc_task *task);
65static void call_decode(struct rpc_task *task);
66static void call_bind(struct rpc_task *task);
67static void call_bind_status(struct rpc_task *task);
68static void call_transmit(struct rpc_task *task);
69#if defined(CONFIG_NFS_V4_1)
70static void call_bc_transmit(struct rpc_task *task);
71#endif /* CONFIG_NFS_V4_1 */
72static void call_status(struct rpc_task *task);
73static void call_transmit_status(struct rpc_task *task);
74static void call_refresh(struct rpc_task *task);
75static void call_refreshresult(struct rpc_task *task);
76static void call_timeout(struct rpc_task *task);
77static void call_connect(struct rpc_task *task);
78static void call_connect_status(struct rpc_task *task);
79
80static __be32 *rpc_encode_header(struct rpc_task *task);
81static __be32 *rpc_verify_header(struct rpc_task *task);
82static int rpc_ping(struct rpc_clnt *clnt);
83
84static void rpc_register_client(struct rpc_clnt *clnt)
85{
86 spin_lock(&rpc_client_lock);
87 list_add(&clnt->cl_clients, &all_clients);
88 spin_unlock(&rpc_client_lock);
89}
90
91static void rpc_unregister_client(struct rpc_clnt *clnt)
92{
93 spin_lock(&rpc_client_lock);
94 list_del(&clnt->cl_clients);
95 spin_unlock(&rpc_client_lock);
96}
97
98static int
99rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
100{
101 static uint32_t clntid;
102 struct nameidata nd;
103 struct path path;
104 char name[15];
105 struct qstr q = {
106 .name = name,
107 };
108 int error;
109
110 clnt->cl_path.mnt = ERR_PTR(-ENOENT);
111 clnt->cl_path.dentry = ERR_PTR(-ENOENT);
112 if (dir_name == NULL)
113 return 0;
114
115 path.mnt = rpc_get_mount();
116 if (IS_ERR(path.mnt))
117 return PTR_ERR(path.mnt);
118 error = vfs_path_lookup(path.mnt->mnt_root, path.mnt, dir_name, 0, &nd);
119 if (error)
120 goto err;
121
122 for (;;) {
123 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
124 name[sizeof(name) - 1] = '\0';
125 q.hash = full_name_hash(q.name, q.len);
126 path.dentry = rpc_create_client_dir(nd.path.dentry, &q, clnt);
127 if (!IS_ERR(path.dentry))
128 break;
129 error = PTR_ERR(path.dentry);
130 if (error != -EEXIST) {
131 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
132 " %s/%s, error %d\n",
133 dir_name, name, error);
134 goto err_path_put;
135 }
136 }
137 path_put(&nd.path);
138 clnt->cl_path = path;
139 return 0;
140err_path_put:
141 path_put(&nd.path);
142err:
143 rpc_put_mount();
144 return error;
145}
146
147static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
148{
149 struct rpc_program *program = args->program;
150 struct rpc_version *version;
151 struct rpc_clnt *clnt = NULL;
152 struct rpc_auth *auth;
153 int err;
154 size_t len;
155
156 /* sanity check the name before trying to print it */
157 err = -EINVAL;
158 len = strlen(args->servername);
159 if (len > RPC_MAXNETNAMELEN)
160 goto out_no_rpciod;
161 len++;
162
163 dprintk("RPC: creating %s client for %s (xprt %p)\n",
164 program->name, args->servername, xprt);
165
166 err = rpciod_up();
167 if (err)
168 goto out_no_rpciod;
169 err = -EINVAL;
170 if (!xprt)
171 goto out_no_xprt;
172
173 if (args->version >= program->nrvers)
174 goto out_err;
175 version = program->version[args->version];
176 if (version == NULL)
177 goto out_err;
178
179 err = -ENOMEM;
180 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
181 if (!clnt)
182 goto out_err;
183 clnt->cl_parent = clnt;
184
185 clnt->cl_server = clnt->cl_inline_name;
186 if (len > sizeof(clnt->cl_inline_name)) {
187 char *buf = kmalloc(len, GFP_KERNEL);
188 if (buf != NULL)
189 clnt->cl_server = buf;
190 else
191 len = sizeof(clnt->cl_inline_name);
192 }
193 strlcpy(clnt->cl_server, args->servername, len);
194
195 clnt->cl_xprt = xprt;
196 clnt->cl_procinfo = version->procs;
197 clnt->cl_maxproc = version->nrprocs;
198 clnt->cl_protname = program->name;
199 clnt->cl_prog = args->prognumber ? : program->number;
200 clnt->cl_vers = version->number;
201 clnt->cl_stats = program->stats;
202 clnt->cl_metrics = rpc_alloc_iostats(clnt);
203 err = -ENOMEM;
204 if (clnt->cl_metrics == NULL)
205 goto out_no_stats;
206 clnt->cl_program = program;
207 INIT_LIST_HEAD(&clnt->cl_tasks);
208 spin_lock_init(&clnt->cl_lock);
209
210 if (!xprt_bound(clnt->cl_xprt))
211 clnt->cl_autobind = 1;
212
213 clnt->cl_timeout = xprt->timeout;
214 if (args->timeout != NULL) {
215 memcpy(&clnt->cl_timeout_default, args->timeout,
216 sizeof(clnt->cl_timeout_default));
217 clnt->cl_timeout = &clnt->cl_timeout_default;
218 }
219
220 clnt->cl_rtt = &clnt->cl_rtt_default;
221 rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
222 clnt->cl_principal = NULL;
223 if (args->client_name) {
224 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
225 if (!clnt->cl_principal)
226 goto out_no_principal;
227 }
228
229 kref_init(&clnt->cl_kref);
230
231 err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
232 if (err < 0)
233 goto out_no_path;
234
235 auth = rpcauth_create(args->authflavor, clnt);
236 if (IS_ERR(auth)) {
237 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
238 args->authflavor);
239 err = PTR_ERR(auth);
240 goto out_no_auth;
241 }
242
243 /* save the nodename */
244 clnt->cl_nodelen = strlen(init_utsname()->nodename);
245 if (clnt->cl_nodelen > UNX_MAXNODENAME)
246 clnt->cl_nodelen = UNX_MAXNODENAME;
247 memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
248 rpc_register_client(clnt);
249 return clnt;
250
251out_no_auth:
252 if (!IS_ERR(clnt->cl_path.dentry)) {
253 rpc_remove_client_dir(clnt->cl_path.dentry);
254 rpc_put_mount();
255 }
256out_no_path:
257 kfree(clnt->cl_principal);
258out_no_principal:
259 rpc_free_iostats(clnt->cl_metrics);
260out_no_stats:
261 if (clnt->cl_server != clnt->cl_inline_name)
262 kfree(clnt->cl_server);
263 kfree(clnt);
264out_err:
265 xprt_put(xprt);
266out_no_xprt:
267 rpciod_down();
268out_no_rpciod:
269 return ERR_PTR(err);
270}
271
272/*
273 * rpc_create - create an RPC client and transport with one call
274 * @args: rpc_clnt create argument structure
275 *
276 * Creates and initializes an RPC transport and an RPC client.
277 *
278 * It can ping the server in order to determine if it is up, and to see if
279 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables
280 * this behavior so asynchronous tasks can also use rpc_create.
281 */
282struct rpc_clnt *rpc_create(struct rpc_create_args *args)
283{
284 struct rpc_xprt *xprt;
285 struct rpc_clnt *clnt;
286 struct xprt_create xprtargs = {
287 .ident = args->protocol,
288 .srcaddr = args->saddress,
289 .dstaddr = args->address,
290 .addrlen = args->addrsize,
291 .bc_xprt = args->bc_xprt,
292 };
293 char servername[48];
294
295 /*
296 * If the caller chooses not to specify a hostname, whip
297 * up a string representation of the passed-in address.
298 */
299 if (args->servername == NULL) {
300 servername[0] = '\0';
301 switch (args->address->sa_family) {
302 case AF_INET: {
303 struct sockaddr_in *sin =
304 (struct sockaddr_in *)args->address;
305 snprintf(servername, sizeof(servername), "%pI4",
306 &sin->sin_addr.s_addr);
307 break;
308 }
309 case AF_INET6: {
310 struct sockaddr_in6 *sin =
311 (struct sockaddr_in6 *)args->address;
312 snprintf(servername, sizeof(servername), "%pI6",
313 &sin->sin6_addr);
314 break;
315 }
316 default:
317 /* caller wants default server name, but
318 * address family isn't recognized. */
319 return ERR_PTR(-EINVAL);
320 }
321 args->servername = servername;
322 }
323
324 xprt = xprt_create_transport(&xprtargs);
325 if (IS_ERR(xprt))
326 return (struct rpc_clnt *)xprt;
327
328 /*
329 * By default, kernel RPC client connects from a reserved port.
330 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
331 * but it is always enabled for rpciod, which handles the connect
332 * operation.
333 */
334 xprt->resvport = 1;
335 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
336 xprt->resvport = 0;
337
338 clnt = rpc_new_client(args, xprt);
339 if (IS_ERR(clnt))
340 return clnt;
341
342 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
343 int err = rpc_ping(clnt);
344 if (err != 0) {
345 rpc_shutdown_client(clnt);
346 return ERR_PTR(err);
347 }
348 }
349
350 clnt->cl_softrtry = 1;
351 if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
352 clnt->cl_softrtry = 0;
353
354 if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
355 clnt->cl_autobind = 1;
356 if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
357 clnt->cl_discrtry = 1;
358 if (!(args->flags & RPC_CLNT_CREATE_QUIET))
359 clnt->cl_chatty = 1;
360
361 return clnt;
362}
363EXPORT_SYMBOL_GPL(rpc_create);
364
365/*
366 * This function clones the RPC client structure. It allows us to share the
367 * same transport while varying parameters such as the authentication
368 * flavour.
369 */
370struct rpc_clnt *
371rpc_clone_client(struct rpc_clnt *clnt)
372{
373 struct rpc_clnt *new;
374 int err = -ENOMEM;
375
376 new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
377 if (!new)
378 goto out_no_clnt;
379 new->cl_parent = clnt;
380 /* Turn off autobind on clones */
381 new->cl_autobind = 0;
382 INIT_LIST_HEAD(&new->cl_tasks);
383 spin_lock_init(&new->cl_lock);
384 rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
385 new->cl_metrics = rpc_alloc_iostats(clnt);
386 if (new->cl_metrics == NULL)
387 goto out_no_stats;
388 if (clnt->cl_principal) {
389 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
390 if (new->cl_principal == NULL)
391 goto out_no_principal;
392 }
393 kref_init(&new->cl_kref);
394 err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
395 if (err != 0)
396 goto out_no_path;
397 if (new->cl_auth)
398 atomic_inc(&new->cl_auth->au_count);
399 xprt_get(clnt->cl_xprt);
400 kref_get(&clnt->cl_kref);
401 rpc_register_client(new);
402 rpciod_up();
403 return new;
404out_no_path:
405 kfree(new->cl_principal);
406out_no_principal:
407 rpc_free_iostats(new->cl_metrics);
408out_no_stats:
409 kfree(new);
410out_no_clnt:
411 dprintk("RPC: %s: returned error %d\n", __func__, err);
412 return ERR_PTR(err);
413}
414EXPORT_SYMBOL_GPL(rpc_clone_client);
415
416/*
417 * Properly shut down an RPC client, terminating all outstanding
418 * requests.
419 */
420void rpc_shutdown_client(struct rpc_clnt *clnt)
421{
422 dprintk("RPC: shutting down %s client for %s\n",
423 clnt->cl_protname, clnt->cl_server);
424
425 while (!list_empty(&clnt->cl_tasks)) {
426 rpc_killall_tasks(clnt);
427 wait_event_timeout(destroy_wait,
428 list_empty(&clnt->cl_tasks), 1*HZ);
429 }
430
431 rpc_release_client(clnt);
432}
433EXPORT_SYMBOL_GPL(rpc_shutdown_client);
434
435/*
436 * Free an RPC client
437 */
438static void
439rpc_free_client(struct kref *kref)
440{
441 struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
442
443 dprintk("RPC: destroying %s client for %s\n",
444 clnt->cl_protname, clnt->cl_server);
445 if (!IS_ERR(clnt->cl_path.dentry)) {
446 rpc_remove_client_dir(clnt->cl_path.dentry);
447 rpc_put_mount();
448 }
449 if (clnt->cl_parent != clnt) {
450 rpc_release_client(clnt->cl_parent);
451 goto out_free;
452 }
453 if (clnt->cl_server != clnt->cl_inline_name)
454 kfree(clnt->cl_server);
455out_free:
456 rpc_unregister_client(clnt);
457 rpc_free_iostats(clnt->cl_metrics);
458 kfree(clnt->cl_principal);
459 clnt->cl_metrics = NULL;
460 xprt_put(clnt->cl_xprt);
461 rpciod_down();
462 kfree(clnt);
463}
464
465/*
466 * Free an RPC client
467 */
468static void
469rpc_free_auth(struct kref *kref)
470{
471 struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
472
473 if (clnt->cl_auth == NULL) {
474 rpc_free_client(kref);
475 return;
476 }
477
478 /*
479 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
480 * release remaining GSS contexts. This mechanism ensures
481 * that it can do so safely.
482 */
483 kref_init(kref);
484 rpcauth_release(clnt->cl_auth);
485 clnt->cl_auth = NULL;
486 kref_put(kref, rpc_free_client);
487}
488
489/*
490 * Release reference to the RPC client
491 */
492void
493rpc_release_client(struct rpc_clnt *clnt)
494{
495 dprintk("RPC: rpc_release_client(%p)\n", clnt);
496
497 if (list_empty(&clnt->cl_tasks))
498 wake_up(&destroy_wait);
499 kref_put(&clnt->cl_kref, rpc_free_auth);
500}
501
502/**
503 * rpc_bind_new_program - bind a new RPC program to an existing client
504 * @old: old rpc_client
505 * @program: rpc program to set
506 * @vers: rpc program version
507 *
508 * Clones the rpc client and sets up a new RPC program. This is mainly
509 * of use for enabling different RPC programs to share the same transport.
510 * The Sun NFSv2/v3 ACL protocol can do this.
511 */
512struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
513 struct rpc_program *program,
514 u32 vers)
515{
516 struct rpc_clnt *clnt;
517 struct rpc_version *version;
518 int err;
519
520 BUG_ON(vers >= program->nrvers || !program->version[vers]);
521 version = program->version[vers];
522 clnt = rpc_clone_client(old);
523 if (IS_ERR(clnt))
524 goto out;
525 clnt->cl_procinfo = version->procs;
526 clnt->cl_maxproc = version->nrprocs;
527 clnt->cl_protname = program->name;
528 clnt->cl_prog = program->number;
529 clnt->cl_vers = version->number;
530 clnt->cl_stats = program->stats;
531 err = rpc_ping(clnt);
532 if (err != 0) {
533 rpc_shutdown_client(clnt);
534 clnt = ERR_PTR(err);
535 }
536out:
537 return clnt;
538}
539EXPORT_SYMBOL_GPL(rpc_bind_new_program);
540
541/*
542 * Default callback for async RPC calls
543 */
544static void
545rpc_default_callback(struct rpc_task *task, void *data)
546{
547}
548
549static const struct rpc_call_ops rpc_default_ops = {
550 .rpc_call_done = rpc_default_callback,
551};
552
553/**
554 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
555 * @task_setup_data: pointer to task initialisation data
556 */
557struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
558{
559 struct rpc_task *task, *ret;
560
561 task = rpc_new_task(task_setup_data);
562 if (task == NULL) {
563 rpc_release_calldata(task_setup_data->callback_ops,
564 task_setup_data->callback_data);
565 ret = ERR_PTR(-ENOMEM);
566 goto out;
567 }
568
569 if (task->tk_status != 0) {
570 ret = ERR_PTR(task->tk_status);
571 rpc_put_task(task);
572 goto out;
573 }
574 atomic_inc(&task->tk_count);
575 rpc_execute(task);
576 ret = task;
577out:
578 return ret;
579}
580EXPORT_SYMBOL_GPL(rpc_run_task);
581
582/**
583 * rpc_call_sync - Perform a synchronous RPC call
584 * @clnt: pointer to RPC client
585 * @msg: RPC call parameters
586 * @flags: RPC call flags
587 */
588int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
589{
590 struct rpc_task *task;
591 struct rpc_task_setup task_setup_data = {
592 .rpc_client = clnt,
593 .rpc_message = msg,
594 .callback_ops = &rpc_default_ops,
595 .flags = flags,
596 };
597 int status;
598
599 BUG_ON(flags & RPC_TASK_ASYNC);
600
601 task = rpc_run_task(&task_setup_data);
602 if (IS_ERR(task))
603 return PTR_ERR(task);
604 status = task->tk_status;
605 rpc_put_task(task);
606 return status;
607}
608EXPORT_SYMBOL_GPL(rpc_call_sync);
609
610/**
611 * rpc_call_async - Perform an asynchronous RPC call
612 * @clnt: pointer to RPC client
613 * @msg: RPC call parameters
614 * @flags: RPC call flags
615 * @tk_ops: RPC call ops
616 * @data: user call data
617 */
618int
619rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
620 const struct rpc_call_ops *tk_ops, void *data)
621{
622 struct rpc_task *task;
623 struct rpc_task_setup task_setup_data = {
624 .rpc_client = clnt,
625 .rpc_message = msg,
626 .callback_ops = tk_ops,
627 .callback_data = data,
628 .flags = flags|RPC_TASK_ASYNC,
629 };
630
631 task = rpc_run_task(&task_setup_data);
632 if (IS_ERR(task))
633 return PTR_ERR(task);
634 rpc_put_task(task);
635 return 0;
636}
637EXPORT_SYMBOL_GPL(rpc_call_async);
638
639#if defined(CONFIG_NFS_V4_1)
640/**
641 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
642 * rpc_execute against it
643 * @req: RPC request
644 * @tk_ops: RPC call ops
645 */
646struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
647 const struct rpc_call_ops *tk_ops)
648{
649 struct rpc_task *task;
650 struct xdr_buf *xbufp = &req->rq_snd_buf;
651 struct rpc_task_setup task_setup_data = {
652 .callback_ops = tk_ops,
653 };
654
655 dprintk("RPC: rpc_run_bc_task req= %p\n", req);
656 /*
657 * Create an rpc_task to send the data
658 */
659 task = rpc_new_task(&task_setup_data);
660 if (!task) {
661 xprt_free_bc_request(req);
662 task = ERR_PTR(-ENOMEM);
663 goto out;
664 }
665 task->tk_rqstp = req;
666
667 /*
668 * Set up the xdr_buf length.
669 * This also indicates that the buffer is XDR encoded already.
670 */
671 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
672 xbufp->tail[0].iov_len;
673
674 task->tk_action = call_bc_transmit;
675 atomic_inc(&task->tk_count);
676 BUG_ON(atomic_read(&task->tk_count) != 2);
677 rpc_execute(task);
678
679out:
680 dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
681 return task;
682}
683#endif /* CONFIG_NFS_V4_1 */
684
685void
686rpc_call_start(struct rpc_task *task)
687{
688 task->tk_action = call_start;
689}
690EXPORT_SYMBOL_GPL(rpc_call_start);
691
692/**
693 * rpc_peeraddr - extract remote peer address from clnt's xprt
694 * @clnt: RPC client structure
695 * @buf: target buffer
696 * @bufsize: length of target buffer
697 *
698 * Returns the number of bytes that are actually in the stored address.
699 */
700size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
701{
702 size_t bytes;
703 struct rpc_xprt *xprt = clnt->cl_xprt;
704
705 bytes = sizeof(xprt->addr);
706 if (bytes > bufsize)
707 bytes = bufsize;
708 memcpy(buf, &clnt->cl_xprt->addr, bytes);
709 return xprt->addrlen;
710}
711EXPORT_SYMBOL_GPL(rpc_peeraddr);
712
713/**
714 * rpc_peeraddr2str - return remote peer address in printable format
715 * @clnt: RPC client structure
716 * @format: address format
717 *
718 */
719const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
720 enum rpc_display_format_t format)
721{
722 struct rpc_xprt *xprt = clnt->cl_xprt;
723
724 if (xprt->address_strings[format] != NULL)
725 return xprt->address_strings[format];
726 else
727 return "unprintable";
728}
729EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
730
731void
732rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
733{
734 struct rpc_xprt *xprt = clnt->cl_xprt;
735 if (xprt->ops->set_buffer_size)
736 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
737}
738EXPORT_SYMBOL_GPL(rpc_setbufsize);
739
740/*
741 * Return size of largest payload RPC client can support, in bytes
742 *
743 * For stream transports, this is one RPC record fragment (see RFC
744 * 1831), as we don't support multi-record requests yet. For datagram
745 * transports, this is the size of an IP packet minus the IP, UDP, and
746 * RPC header sizes.
747 */
748size_t rpc_max_payload(struct rpc_clnt *clnt)
749{
750 return clnt->cl_xprt->max_payload;
751}
752EXPORT_SYMBOL_GPL(rpc_max_payload);
753
754/**
755 * rpc_force_rebind - force transport to check that remote port is unchanged
756 * @clnt: client to rebind
757 *
758 */
759void rpc_force_rebind(struct rpc_clnt *clnt)
760{
761 if (clnt->cl_autobind)
762 xprt_clear_bound(clnt->cl_xprt);
763}
764EXPORT_SYMBOL_GPL(rpc_force_rebind);
765
766/*
767 * Restart an (async) RPC call from the call_prepare state.
768 * Usually called from within the exit handler.
769 */
770void
771rpc_restart_call_prepare(struct rpc_task *task)
772{
773 if (RPC_ASSASSINATED(task))
774 return;
775 task->tk_action = rpc_prepare_task;
776}
777EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
778
779/*
780 * Restart an (async) RPC call. Usually called from within the
781 * exit handler.
782 */
783void
784rpc_restart_call(struct rpc_task *task)
785{
786 if (RPC_ASSASSINATED(task))
787 return;
788
789 task->tk_action = call_start;
790}
791EXPORT_SYMBOL_GPL(rpc_restart_call);
792
793#ifdef RPC_DEBUG
794static const char *rpc_proc_name(const struct rpc_task *task)
795{
796 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
797
798 if (proc) {
799 if (proc->p_name)
800 return proc->p_name;
801 else
802 return "NULL";
803 } else
804 return "no proc";
805}
806#endif
807
808/*
809 * 0. Initial state
810 *
811 * Other FSM states can be visited zero or more times, but
812 * this state is visited exactly once for each RPC.
813 */
814static void
815call_start(struct rpc_task *task)
816{
817 struct rpc_clnt *clnt = task->tk_client;
818
819 dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
820 clnt->cl_protname, clnt->cl_vers,
821 rpc_proc_name(task),
822 (RPC_IS_ASYNC(task) ? "async" : "sync"));
823
824 /* Increment call count */
825 task->tk_msg.rpc_proc->p_count++;
826 clnt->cl_stats->rpccnt++;
827 task->tk_action = call_reserve;
828}
829
830/*
831 * 1. Reserve an RPC call slot
832 */
833static void
834call_reserve(struct rpc_task *task)
835{
836 dprint_status(task);
837
838 if (!rpcauth_uptodatecred(task)) {
839 task->tk_action = call_refresh;
840 return;
841 }
842
843 task->tk_status = 0;
844 task->tk_action = call_reserveresult;
845 xprt_reserve(task);
846}
847
848/*
849 * 1b. Grok the result of xprt_reserve()
850 */
851static void
852call_reserveresult(struct rpc_task *task)
853{
854 int status = task->tk_status;
855
856 dprint_status(task);
857
858 /*
859 * After a call to xprt_reserve(), we must have either
860 * a request slot or else an error status.
861 */
862 task->tk_status = 0;
863 if (status >= 0) {
864 if (task->tk_rqstp) {
865 task->tk_action = call_allocate;
866 return;
867 }
868
869 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
870 __func__, status);
871 rpc_exit(task, -EIO);
872 return;
873 }
874
875 /*
876 * Even though there was an error, we may have acquired
877 * a request slot somehow. Make sure not to leak it.
878 */
879 if (task->tk_rqstp) {
880 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
881 __func__, status);
882 xprt_release(task);
883 }
884
885 switch (status) {
886 case -EAGAIN: /* woken up; retry */
887 task->tk_action = call_reserve;
888 return;
889 case -EIO: /* probably a shutdown */
890 break;
891 default:
892 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
893 __func__, status);
894 break;
895 }
896 rpc_exit(task, status);
897}
898
899/*
900 * 2. Allocate the buffer. For details, see sched.c:rpc_malloc.
901 * (Note: buffer memory is freed in xprt_release).
902 */
903static void
904call_allocate(struct rpc_task *task)
905{
906 unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
907 struct rpc_rqst *req = task->tk_rqstp;
908 struct rpc_xprt *xprt = task->tk_xprt;
909 struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
910
911 dprint_status(task);
912
913 task->tk_status = 0;
914 task->tk_action = call_bind;
915
916 if (req->rq_buffer)
917 return;
918
919 if (proc->p_proc != 0) {
920 BUG_ON(proc->p_arglen == 0);
921 if (proc->p_decode != NULL)
922 BUG_ON(proc->p_replen == 0);
923 }
924
925 /*
926 * Calculate the size (in quads) of the RPC call
927 * and reply headers, and convert both values
928 * to byte sizes.
929 */
930 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
931 req->rq_callsize <<= 2;
932 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
933 req->rq_rcvsize <<= 2;
934
935 req->rq_buffer = xprt->ops->buf_alloc(task,
936 req->rq_callsize + req->rq_rcvsize);
937 if (req->rq_buffer != NULL)
938 return;
939
940 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
941
942 if (RPC_IS_ASYNC(task) || !signalled()) {
943 task->tk_action = call_allocate;
944 rpc_delay(task, HZ>>4);
945 return;
946 }
947
948 rpc_exit(task, -ERESTARTSYS);
949}
950
951static inline int
952rpc_task_need_encode(struct rpc_task *task)
953{
954 return task->tk_rqstp->rq_snd_buf.len == 0;
955}
956
957static inline void
958rpc_task_force_reencode(struct rpc_task *task)
959{
960 task->tk_rqstp->rq_snd_buf.len = 0;
961 task->tk_rqstp->rq_bytes_sent = 0;
962}
963
964static inline void
965rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
966{
967 buf->head[0].iov_base = start;
968 buf->head[0].iov_len = len;
969 buf->tail[0].iov_len = 0;
970 buf->page_len = 0;
971 buf->flags = 0;
972 buf->len = 0;
973 buf->buflen = len;
974}
975
976/*
977 * 3. Encode arguments of an RPC call
978 */
979static void
980rpc_xdr_encode(struct rpc_task *task)
981{
982 struct rpc_rqst *req = task->tk_rqstp;
983 kxdrproc_t encode;
984 __be32 *p;
985
986 dprint_status(task);
987
988 rpc_xdr_buf_init(&req->rq_snd_buf,
989 req->rq_buffer,
990 req->rq_callsize);
991 rpc_xdr_buf_init(&req->rq_rcv_buf,
992 (char *)req->rq_buffer + req->rq_callsize,
993 req->rq_rcvsize);
994
995 p = rpc_encode_header(task);
996 if (p == NULL) {
997 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
998 rpc_exit(task, -EIO);
999 return;
1000 }
1001
1002 encode = task->tk_msg.rpc_proc->p_encode;
1003 if (encode == NULL)
1004 return;
1005
1006 task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1007 task->tk_msg.rpc_argp);
1008}
1009
1010/*
1011 * 4. Get the server port number if not yet set
1012 */
1013static void
1014call_bind(struct rpc_task *task)
1015{
1016 struct rpc_xprt *xprt = task->tk_xprt;
1017
1018 dprint_status(task);
1019
1020 task->tk_action = call_connect;
1021 if (!xprt_bound(xprt)) {
1022 task->tk_action = call_bind_status;
1023 task->tk_timeout = xprt->bind_timeout;
1024 xprt->ops->rpcbind(task);
1025 }
1026}
1027
1028/*
1029 * 4a. Sort out bind result
1030 */
1031static void
1032call_bind_status(struct rpc_task *task)
1033{
1034 int status = -EIO;
1035
1036 if (task->tk_status >= 0) {
1037 dprint_status(task);
1038 task->tk_status = 0;
1039 task->tk_action = call_connect;
1040 return;
1041 }
1042
1043 switch (task->tk_status) {
1044 case -ENOMEM:
1045 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1046 rpc_delay(task, HZ >> 2);
1047 goto retry_timeout;
1048 case -EACCES:
1049 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1050 "unavailable\n", task->tk_pid);
1051 /* fail immediately if this is an RPC ping */
1052 if (task->tk_msg.rpc_proc->p_proc == 0) {
1053 status = -EOPNOTSUPP;
1054 break;
1055 }
1056 rpc_delay(task, 3*HZ);
1057 goto retry_timeout;
1058 case -ETIMEDOUT:
1059 dprintk("RPC: %5u rpcbind request timed out\n",
1060 task->tk_pid);
1061 goto retry_timeout;
1062 case -EPFNOSUPPORT:
1063 /* server doesn't support any rpcbind version we know of */
1064 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1065 task->tk_pid);
1066 break;
1067 case -EPROTONOSUPPORT:
1068 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1069 task->tk_pid);
1070 task->tk_status = 0;
1071 task->tk_action = call_bind;
1072 return;
1073 case -ECONNREFUSED: /* connection problems */
1074 case -ECONNRESET:
1075 case -ENOTCONN:
1076 case -EHOSTDOWN:
1077 case -EHOSTUNREACH:
1078 case -ENETUNREACH:
1079 case -EPIPE:
1080 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1081 task->tk_pid, task->tk_status);
1082 if (!RPC_IS_SOFTCONN(task)) {
1083 rpc_delay(task, 5*HZ);
1084 goto retry_timeout;
1085 }
1086 status = task->tk_status;
1087 break;
1088 default:
1089 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1090 task->tk_pid, -task->tk_status);
1091 }
1092
1093 rpc_exit(task, status);
1094 return;
1095
1096retry_timeout:
1097 task->tk_action = call_timeout;
1098}
1099
1100/*
1101 * 4b. Connect to the RPC server
1102 */
1103static void
1104call_connect(struct rpc_task *task)
1105{
1106 struct rpc_xprt *xprt = task->tk_xprt;
1107
1108 dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1109 task->tk_pid, xprt,
1110 (xprt_connected(xprt) ? "is" : "is not"));
1111
1112 task->tk_action = call_transmit;
1113 if (!xprt_connected(xprt)) {
1114 task->tk_action = call_connect_status;
1115 if (task->tk_status < 0)
1116 return;
1117 xprt_connect(task);
1118 }
1119}
1120
1121/*
1122 * 4c. Sort out connect result
1123 */
1124static void
1125call_connect_status(struct rpc_task *task)
1126{
1127 struct rpc_clnt *clnt = task->tk_client;
1128 int status = task->tk_status;
1129
1130 dprint_status(task);
1131
1132 task->tk_status = 0;
1133 if (status >= 0 || status == -EAGAIN) {
1134 clnt->cl_stats->netreconn++;
1135 task->tk_action = call_transmit;
1136 return;
1137 }
1138
1139 switch (status) {
1140 /* if soft mounted, test if we've timed out */
1141 case -ETIMEDOUT:
1142 task->tk_action = call_timeout;
1143 break;
1144 default:
1145 rpc_exit(task, -EIO);
1146 }
1147}
1148
1149/*
1150 * 5. Transmit the RPC request, and wait for reply
1151 */
1152static void
1153call_transmit(struct rpc_task *task)
1154{
1155 dprint_status(task);
1156
1157 task->tk_action = call_status;
1158 if (task->tk_status < 0)
1159 return;
1160 task->tk_status = xprt_prepare_transmit(task);
1161 if (task->tk_status != 0)
1162 return;
1163 task->tk_action = call_transmit_status;
1164 /* Encode here so that rpcsec_gss can use correct sequence number. */
1165 if (rpc_task_need_encode(task)) {
1166 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1167 rpc_xdr_encode(task);
1168 /* Did the encode result in an error condition? */
1169 if (task->tk_status != 0) {
1170 /* Was the error nonfatal? */
1171 if (task->tk_status == -EAGAIN)
1172 rpc_delay(task, HZ >> 4);
1173 else
1174 rpc_exit(task, task->tk_status);
1175 return;
1176 }
1177 }
1178 xprt_transmit(task);
1179 if (task->tk_status < 0)
1180 return;
1181 /*
1182 * On success, ensure that we call xprt_end_transmit() before sleeping
1183 * in order to allow access to the socket to other RPC requests.
1184 */
1185 call_transmit_status(task);
1186 if (rpc_reply_expected(task))
1187 return;
1188 task->tk_action = rpc_exit_task;
1189 rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1190}
1191
1192/*
1193 * 5a. Handle cleanup after a transmission
1194 */
1195static void
1196call_transmit_status(struct rpc_task *task)
1197{
1198 task->tk_action = call_status;
1199
1200 /*
1201 * Common case: success. Force the compiler to put this
1202 * test first.
1203 */
1204 if (task->tk_status == 0) {
1205 xprt_end_transmit(task);
1206 rpc_task_force_reencode(task);
1207 return;
1208 }
1209
1210 switch (task->tk_status) {
1211 case -EAGAIN:
1212 break;
1213 default:
1214 dprint_status(task);
1215 xprt_end_transmit(task);
1216 rpc_task_force_reencode(task);
1217 break;
1218 /*
1219 * Special cases: if we've been waiting on the
1220 * socket's write_space() callback, or if the
1221 * socket just returned a connection error,
1222 * then hold onto the transport lock.
1223 */
1224 case -ECONNREFUSED:
1225 case -EHOSTDOWN:
1226 case -EHOSTUNREACH:
1227 case -ENETUNREACH:
1228 if (RPC_IS_SOFTCONN(task)) {
1229 xprt_end_transmit(task);
1230 rpc_exit(task, task->tk_status);
1231 break;
1232 }
1233 case -ECONNRESET:
1234 case -ENOTCONN:
1235 case -EPIPE:
1236 rpc_task_force_reencode(task);
1237 }
1238}
1239
1240#if defined(CONFIG_NFS_V4_1)
1241/*
1242 * 5b. Send the backchannel RPC reply. On error, drop the reply. In
1243 * addition, disconnect on connectivity errors.
1244 */
1245static void
1246call_bc_transmit(struct rpc_task *task)
1247{
1248 struct rpc_rqst *req = task->tk_rqstp;
1249
1250 BUG_ON(task->tk_status != 0);
1251 task->tk_status = xprt_prepare_transmit(task);
1252 if (task->tk_status == -EAGAIN) {
1253 /*
1254 * Could not reserve the transport. Try again after the
1255 * transport is released.
1256 */
1257 task->tk_status = 0;
1258 task->tk_action = call_bc_transmit;
1259 return;
1260 }
1261
1262 task->tk_action = rpc_exit_task;
1263 if (task->tk_status < 0) {
1264 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1265 "error: %d\n", task->tk_status);
1266 return;
1267 }
1268
1269 xprt_transmit(task);
1270 xprt_end_transmit(task);
1271 dprint_status(task);
1272 switch (task->tk_status) {
1273 case 0:
1274 /* Success */
1275 break;
1276 case -EHOSTDOWN:
1277 case -EHOSTUNREACH:
1278 case -ENETUNREACH:
1279 case -ETIMEDOUT:
1280 /*
1281 * Problem reaching the server. Disconnect and let the
1282 * forechannel reestablish the connection. The server will
1283 * have to retransmit the backchannel request and we'll
1284 * reprocess it. Since these ops are idempotent, there's no
1285 * need to cache our reply at this time.
1286 */
1287 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1288 "error: %d\n", task->tk_status);
1289 xprt_conditional_disconnect(task->tk_xprt,
1290 req->rq_connect_cookie);
1291 break;
1292 default:
1293 /*
1294 * We were unable to reply and will have to drop the
1295 * request. The server should reconnect and retransmit.
1296 */
1297 BUG_ON(task->tk_status == -EAGAIN);
1298 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1299 "error: %d\n", task->tk_status);
1300 break;
1301 }
1302 rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1303}
1304#endif /* CONFIG_NFS_V4_1 */
1305
1306/*
1307 * 6. Sort out the RPC call status
1308 */
1309static void
1310call_status(struct rpc_task *task)
1311{
1312 struct rpc_clnt *clnt = task->tk_client;
1313 struct rpc_rqst *req = task->tk_rqstp;
1314 int status;
1315
1316 if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1317 task->tk_status = req->rq_reply_bytes_recvd;
1318
1319 dprint_status(task);
1320
1321 status = task->tk_status;
1322 if (status >= 0) {
1323 task->tk_action = call_decode;
1324 return;
1325 }
1326
1327 task->tk_status = 0;
1328 switch(status) {
1329 case -EHOSTDOWN:
1330 case -EHOSTUNREACH:
1331 case -ENETUNREACH:
1332 /*
1333 * Delay any retries for 3 seconds, then handle as if it
1334 * were a timeout.
1335 */
1336 rpc_delay(task, 3*HZ);
1337 case -ETIMEDOUT:
1338 task->tk_action = call_timeout;
1339 if (task->tk_client->cl_discrtry)
1340 xprt_conditional_disconnect(task->tk_xprt,
1341 req->rq_connect_cookie);
1342 break;
1343 case -ECONNRESET:
1344 case -ECONNREFUSED:
1345 rpc_force_rebind(clnt);
1346 rpc_delay(task, 3*HZ);
1347 case -EPIPE:
1348 case -ENOTCONN:
1349 task->tk_action = call_bind;
1350 break;
1351 case -EAGAIN:
1352 task->tk_action = call_transmit;
1353 break;
1354 case -EIO:
1355 /* shutdown or soft timeout */
1356 rpc_exit(task, status);
1357 break;
1358 default:
1359 if (clnt->cl_chatty)
1360 printk("%s: RPC call returned error %d\n",
1361 clnt->cl_protname, -status);
1362 rpc_exit(task, status);
1363 }
1364}
1365
1366/*
1367 * 6a. Handle RPC timeout
1368 * We do not release the request slot, so we keep using the
1369 * same XID for all retransmits.
1370 */
1371static void
1372call_timeout(struct rpc_task *task)
1373{
1374 struct rpc_clnt *clnt = task->tk_client;
1375
1376 if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1377 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1378 goto retry;
1379 }
1380
1381 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1382 task->tk_timeouts++;
1383
1384 if (RPC_IS_SOFTCONN(task)) {
1385 rpc_exit(task, -ETIMEDOUT);
1386 return;
1387 }
1388 if (RPC_IS_SOFT(task)) {
1389 if (clnt->cl_chatty)
1390 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1391 clnt->cl_protname, clnt->cl_server);
1392 rpc_exit(task, -EIO);
1393 return;
1394 }
1395
1396 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1397 task->tk_flags |= RPC_CALL_MAJORSEEN;
1398 if (clnt->cl_chatty)
1399 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1400 clnt->cl_protname, clnt->cl_server);
1401 }
1402 rpc_force_rebind(clnt);
1403 /*
1404 * Did our request time out due to an RPCSEC_GSS out-of-sequence
1405 * event? RFC2203 requires the server to drop all such requests.
1406 */
1407 rpcauth_invalcred(task);
1408
1409retry:
1410 clnt->cl_stats->rpcretrans++;
1411 task->tk_action = call_bind;
1412 task->tk_status = 0;
1413}
1414
1415/*
1416 * 7. Decode the RPC reply
1417 */
1418static void
1419call_decode(struct rpc_task *task)
1420{
1421 struct rpc_clnt *clnt = task->tk_client;
1422 struct rpc_rqst *req = task->tk_rqstp;
1423 kxdrproc_t decode = task->tk_msg.rpc_proc->p_decode;
1424 __be32 *p;
1425
1426 dprintk("RPC: %5u call_decode (status %d)\n",
1427 task->tk_pid, task->tk_status);
1428
1429 if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1430 if (clnt->cl_chatty)
1431 printk(KERN_NOTICE "%s: server %s OK\n",
1432 clnt->cl_protname, clnt->cl_server);
1433 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1434 }
1435
1436 /*
1437 * Ensure that we see all writes made by xprt_complete_rqst()
1438 * before it changed req->rq_reply_bytes_recvd.
1439 */
1440 smp_rmb();
1441 req->rq_rcv_buf.len = req->rq_private_buf.len;
1442
1443 /* Check that the softirq receive buffer is valid */
1444 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1445 sizeof(req->rq_rcv_buf)) != 0);
1446
1447 if (req->rq_rcv_buf.len < 12) {
1448 if (!RPC_IS_SOFT(task)) {
1449 task->tk_action = call_bind;
1450 clnt->cl_stats->rpcretrans++;
1451 goto out_retry;
1452 }
1453 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
1454 clnt->cl_protname, task->tk_status);
1455 task->tk_action = call_timeout;
1456 goto out_retry;
1457 }
1458
1459 p = rpc_verify_header(task);
1460 if (IS_ERR(p)) {
1461 if (p == ERR_PTR(-EAGAIN))
1462 goto out_retry;
1463 return;
1464 }
1465
1466 task->tk_action = rpc_exit_task;
1467
1468 if (decode) {
1469 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1470 task->tk_msg.rpc_resp);
1471 }
1472 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1473 task->tk_status);
1474 return;
1475out_retry:
1476 task->tk_status = 0;
1477 /* Note: rpc_verify_header() may have freed the RPC slot */
1478 if (task->tk_rqstp == req) {
1479 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1480 if (task->tk_client->cl_discrtry)
1481 xprt_conditional_disconnect(task->tk_xprt,
1482 req->rq_connect_cookie);
1483 }
1484}
1485
1486/*
1487 * 8. Refresh the credentials if rejected by the server
1488 */
1489static void
1490call_refresh(struct rpc_task *task)
1491{
1492 dprint_status(task);
1493
1494 task->tk_action = call_refreshresult;
1495 task->tk_status = 0;
1496 task->tk_client->cl_stats->rpcauthrefresh++;
1497 rpcauth_refreshcred(task);
1498}
1499
1500/*
1501 * 8a. Process the results of a credential refresh
1502 */
1503static void
1504call_refreshresult(struct rpc_task *task)
1505{
1506 int status = task->tk_status;
1507
1508 dprint_status(task);
1509
1510 task->tk_status = 0;
1511 task->tk_action = call_reserve;
1512 if (status >= 0 && rpcauth_uptodatecred(task))
1513 return;
1514 if (status == -EACCES) {
1515 rpc_exit(task, -EACCES);
1516 return;
1517 }
1518 task->tk_action = call_refresh;
1519 if (status != -ETIMEDOUT)
1520 rpc_delay(task, 3*HZ);
1521 return;
1522}
1523
1524static __be32 *
1525rpc_encode_header(struct rpc_task *task)
1526{
1527 struct rpc_clnt *clnt = task->tk_client;
1528 struct rpc_rqst *req = task->tk_rqstp;
1529 __be32 *p = req->rq_svec[0].iov_base;
1530
1531 /* FIXME: check buffer size? */
1532
1533 p = xprt_skip_transport_header(task->tk_xprt, p);
1534 *p++ = req->rq_xid; /* XID */
1535 *p++ = htonl(RPC_CALL); /* CALL */
1536 *p++ = htonl(RPC_VERSION); /* RPC version */
1537 *p++ = htonl(clnt->cl_prog); /* program number */
1538 *p++ = htonl(clnt->cl_vers); /* program version */
1539 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
1540 p = rpcauth_marshcred(task, p);
1541 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1542 return p;
1543}
1544
1545static __be32 *
1546rpc_verify_header(struct rpc_task *task)
1547{
1548 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1549 int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1550 __be32 *p = iov->iov_base;
1551 u32 n;
1552 int error = -EACCES;
1553
1554 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1555 /* RFC-1014 says that the representation of XDR data must be a
1556 * multiple of four bytes
1557 * - if it isn't pointer subtraction in the NFS client may give
1558 * undefined results
1559 */
1560 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1561 " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1562 task->tk_rqstp->rq_rcv_buf.len);
1563 goto out_eio;
1564 }
1565 if ((len -= 3) < 0)
1566 goto out_overflow;
1567
1568 p += 1; /* skip XID */
1569 if ((n = ntohl(*p++)) != RPC_REPLY) {
1570 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1571 task->tk_pid, __func__, n);
1572 goto out_garbage;
1573 }
1574
1575 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1576 if (--len < 0)
1577 goto out_overflow;
1578 switch ((n = ntohl(*p++))) {
1579 case RPC_AUTH_ERROR:
1580 break;
1581 case RPC_MISMATCH:
1582 dprintk("RPC: %5u %s: RPC call version "
1583 "mismatch!\n",
1584 task->tk_pid, __func__);
1585 error = -EPROTONOSUPPORT;
1586 goto out_err;
1587 default:
1588 dprintk("RPC: %5u %s: RPC call rejected, "
1589 "unknown error: %x\n",
1590 task->tk_pid, __func__, n);
1591 goto out_eio;
1592 }
1593 if (--len < 0)
1594 goto out_overflow;
1595 switch ((n = ntohl(*p++))) {
1596 case RPC_AUTH_REJECTEDCRED:
1597 case RPC_AUTH_REJECTEDVERF:
1598 case RPCSEC_GSS_CREDPROBLEM:
1599 case RPCSEC_GSS_CTXPROBLEM:
1600 if (!task->tk_cred_retry)
1601 break;
1602 task->tk_cred_retry--;
1603 dprintk("RPC: %5u %s: retry stale creds\n",
1604 task->tk_pid, __func__);
1605 rpcauth_invalcred(task);
1606 /* Ensure we obtain a new XID! */
1607 xprt_release(task);
1608 task->tk_action = call_refresh;
1609 goto out_retry;
1610 case RPC_AUTH_BADCRED:
1611 case RPC_AUTH_BADVERF:
1612 /* possibly garbled cred/verf? */
1613 if (!task->tk_garb_retry)
1614 break;
1615 task->tk_garb_retry--;
1616 dprintk("RPC: %5u %s: retry garbled creds\n",
1617 task->tk_pid, __func__);
1618 task->tk_action = call_bind;
1619 goto out_retry;
1620 case RPC_AUTH_TOOWEAK:
1621 printk(KERN_NOTICE "RPC: server %s requires stronger "
1622 "authentication.\n", task->tk_client->cl_server);
1623 break;
1624 default:
1625 dprintk("RPC: %5u %s: unknown auth error: %x\n",
1626 task->tk_pid, __func__, n);
1627 error = -EIO;
1628 }
1629 dprintk("RPC: %5u %s: call rejected %d\n",
1630 task->tk_pid, __func__, n);
1631 goto out_err;
1632 }
1633 if (!(p = rpcauth_checkverf(task, p))) {
1634 dprintk("RPC: %5u %s: auth check failed\n",
1635 task->tk_pid, __func__);
1636 goto out_garbage; /* bad verifier, retry */
1637 }
1638 len = p - (__be32 *)iov->iov_base - 1;
1639 if (len < 0)
1640 goto out_overflow;
1641 switch ((n = ntohl(*p++))) {
1642 case RPC_SUCCESS:
1643 return p;
1644 case RPC_PROG_UNAVAIL:
1645 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1646 task->tk_pid, __func__,
1647 (unsigned int)task->tk_client->cl_prog,
1648 task->tk_client->cl_server);
1649 error = -EPFNOSUPPORT;
1650 goto out_err;
1651 case RPC_PROG_MISMATCH:
1652 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1653 "server %s\n", task->tk_pid, __func__,
1654 (unsigned int)task->tk_client->cl_prog,
1655 (unsigned int)task->tk_client->cl_vers,
1656 task->tk_client->cl_server);
1657 error = -EPROTONOSUPPORT;
1658 goto out_err;
1659 case RPC_PROC_UNAVAIL:
1660 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1661 "version %u on server %s\n",
1662 task->tk_pid, __func__,
1663 rpc_proc_name(task),
1664 task->tk_client->cl_prog,
1665 task->tk_client->cl_vers,
1666 task->tk_client->cl_server);
1667 error = -EOPNOTSUPP;
1668 goto out_err;
1669 case RPC_GARBAGE_ARGS:
1670 dprintk("RPC: %5u %s: server saw garbage\n",
1671 task->tk_pid, __func__);
1672 break; /* retry */
1673 default:
1674 dprintk("RPC: %5u %s: server accept status: %x\n",
1675 task->tk_pid, __func__, n);
1676 /* Also retry */
1677 }
1678
1679out_garbage:
1680 task->tk_client->cl_stats->rpcgarbage++;
1681 if (task->tk_garb_retry) {
1682 task->tk_garb_retry--;
1683 dprintk("RPC: %5u %s: retrying\n",
1684 task->tk_pid, __func__);
1685 task->tk_action = call_bind;
1686out_retry:
1687 return ERR_PTR(-EAGAIN);
1688 }
1689out_eio:
1690 error = -EIO;
1691out_err:
1692 rpc_exit(task, error);
1693 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1694 __func__, error);
1695 return ERR_PTR(error);
1696out_overflow:
1697 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1698 __func__);
1699 goto out_garbage;
1700}
1701
1702static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1703{
1704 return 0;
1705}
1706
1707static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1708{
1709 return 0;
1710}
1711
1712static struct rpc_procinfo rpcproc_null = {
1713 .p_encode = rpcproc_encode_null,
1714 .p_decode = rpcproc_decode_null,
1715};
1716
1717static int rpc_ping(struct rpc_clnt *clnt)
1718{
1719 struct rpc_message msg = {
1720 .rpc_proc = &rpcproc_null,
1721 };
1722 int err;
1723 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1724 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
1725 put_rpccred(msg.rpc_cred);
1726 return err;
1727}
1728
1729struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1730{
1731 struct rpc_message msg = {
1732 .rpc_proc = &rpcproc_null,
1733 .rpc_cred = cred,
1734 };
1735 struct rpc_task_setup task_setup_data = {
1736 .rpc_client = clnt,
1737 .rpc_message = &msg,
1738 .callback_ops = &rpc_default_ops,
1739 .flags = flags,
1740 };
1741 return rpc_run_task(&task_setup_data);
1742}
1743EXPORT_SYMBOL_GPL(rpc_call_null);
1744
1745#ifdef RPC_DEBUG
1746static void rpc_show_header(void)
1747{
1748 printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1749 "-timeout ---ops--\n");
1750}
1751
1752static void rpc_show_task(const struct rpc_clnt *clnt,
1753 const struct rpc_task *task)
1754{
1755 const char *rpc_waitq = "none";
1756 char *p, action[KSYM_SYMBOL_LEN];
1757
1758 if (RPC_IS_QUEUED(task))
1759 rpc_waitq = rpc_qname(task->tk_waitqueue);
1760
1761 /* map tk_action pointer to a function name; then trim off
1762 * the "+0x0 [sunrpc]" */
1763 sprint_symbol(action, (unsigned long)task->tk_action);
1764 p = strchr(action, '+');
1765 if (p)
1766 *p = '\0';
1767
1768 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1769 task->tk_pid, task->tk_flags, task->tk_status,
1770 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1771 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1772 action, rpc_waitq);
1773}
1774
1775void rpc_show_tasks(void)
1776{
1777 struct rpc_clnt *clnt;
1778 struct rpc_task *task;
1779 int header = 0;
1780
1781 spin_lock(&rpc_client_lock);
1782 list_for_each_entry(clnt, &all_clients, cl_clients) {
1783 spin_lock(&clnt->cl_lock);
1784 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1785 if (!header) {
1786 rpc_show_header();
1787 header++;
1788 }
1789 rpc_show_task(clnt, task);
1790 }
1791 spin_unlock(&clnt->cl_lock);
1792 }
1793 spin_unlock(&rpc_client_lock);
1794}
1795#endif