Merge branch 'devel' into next
[sfrench/cifs-2.6.git] / net / sunrpc / clnt.c
1 /*
2  *  linux/net/sunrpc/clnt.c
3  *
4  *  This file contains the high-level RPC interface.
5  *  It is modeled as a finite state machine to support both synchronous
6  *  and asynchronous requests.
7  *
8  *  -   RPC header generation and argument serialization.
9  *  -   Credential refresh.
10  *  -   TCP connect handling.
11  *  -   Retry of operation when it is suspected the operation failed because
12  *      of uid squashing on the server, or when the credentials were stale
13  *      and need to be refreshed, or when a packet was damaged in transit.
14  *      This may be have to be moved to the VFS layer.
15  *
16  *  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/slab.h>
31 #include <linux/smp_lock.h>
32 #include <linux/utsname.h>
33 #include <linux/workqueue.h>
34 #include <linux/in6.h>
35
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/rpc_pipe_fs.h>
38 #include <linux/sunrpc/metrics.h>
39
40
41 #ifdef RPC_DEBUG
42 # define RPCDBG_FACILITY        RPCDBG_CALL
43 #endif
44
45 #define dprint_status(t)                                        \
46         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
47                         __func__, t->tk_status)
48
49 /*
50  * All RPC clients are linked into this list
51  */
52 static LIST_HEAD(all_clients);
53 static DEFINE_SPINLOCK(rpc_client_lock);
54
55 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
56
57
58 static void     call_start(struct rpc_task *task);
59 static void     call_reserve(struct rpc_task *task);
60 static void     call_reserveresult(struct rpc_task *task);
61 static void     call_allocate(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_timeout(struct rpc_task *task);
71 static void     call_connect(struct rpc_task *task);
72 static void     call_connect_status(struct rpc_task *task);
73
74 static __be32   *rpc_encode_header(struct rpc_task *task);
75 static __be32   *rpc_verify_header(struct rpc_task *task);
76 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
77
78 static void rpc_register_client(struct rpc_clnt *clnt)
79 {
80         spin_lock(&rpc_client_lock);
81         list_add(&clnt->cl_clients, &all_clients);
82         spin_unlock(&rpc_client_lock);
83 }
84
85 static void rpc_unregister_client(struct rpc_clnt *clnt)
86 {
87         spin_lock(&rpc_client_lock);
88         list_del(&clnt->cl_clients);
89         spin_unlock(&rpc_client_lock);
90 }
91
92 static int
93 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
94 {
95         static uint32_t clntid;
96         int error;
97
98         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
99         clnt->cl_dentry = ERR_PTR(-ENOENT);
100         if (dir_name == NULL)
101                 return 0;
102
103         clnt->cl_vfsmnt = rpc_get_mount();
104         if (IS_ERR(clnt->cl_vfsmnt))
105                 return PTR_ERR(clnt->cl_vfsmnt);
106
107         for (;;) {
108                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
109                                 "%s/clnt%x", dir_name,
110                                 (unsigned int)clntid++);
111                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
112                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
113                 if (!IS_ERR(clnt->cl_dentry))
114                         return 0;
115                 error = PTR_ERR(clnt->cl_dentry);
116                 if (error != -EEXIST) {
117                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
118                                         clnt->cl_pathname, error);
119                         rpc_put_mount();
120                         return error;
121                 }
122         }
123 }
124
125 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
126 {
127         struct rpc_program      *program = args->program;
128         struct rpc_version      *version;
129         struct rpc_clnt         *clnt = NULL;
130         struct rpc_auth         *auth;
131         int err;
132         size_t len;
133
134         /* sanity check the name before trying to print it */
135         err = -EINVAL;
136         len = strlen(args->servername);
137         if (len > RPC_MAXNETNAMELEN)
138                 goto out_no_rpciod;
139         len++;
140
141         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
142                         program->name, args->servername, xprt);
143
144         err = rpciod_up();
145         if (err)
146                 goto out_no_rpciod;
147         err = -EINVAL;
148         if (!xprt)
149                 goto out_no_xprt;
150
151         if (args->version >= program->nrvers)
152                 goto out_err;
153         version = program->version[args->version];
154         if (version == NULL)
155                 goto out_err;
156
157         err = -ENOMEM;
158         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
159         if (!clnt)
160                 goto out_err;
161         clnt->cl_parent = clnt;
162
163         clnt->cl_server = clnt->cl_inline_name;
164         if (len > sizeof(clnt->cl_inline_name)) {
165                 char *buf = kmalloc(len, GFP_KERNEL);
166                 if (buf != NULL)
167                         clnt->cl_server = buf;
168                 else
169                         len = sizeof(clnt->cl_inline_name);
170         }
171         strlcpy(clnt->cl_server, args->servername, len);
172
173         clnt->cl_xprt     = xprt;
174         clnt->cl_procinfo = version->procs;
175         clnt->cl_maxproc  = version->nrprocs;
176         clnt->cl_protname = program->name;
177         clnt->cl_prog     = args->prognumber ? : program->number;
178         clnt->cl_vers     = version->number;
179         clnt->cl_stats    = program->stats;
180         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
181         err = -ENOMEM;
182         if (clnt->cl_metrics == NULL)
183                 goto out_no_stats;
184         clnt->cl_program  = program;
185         INIT_LIST_HEAD(&clnt->cl_tasks);
186         spin_lock_init(&clnt->cl_lock);
187
188         if (!xprt_bound(clnt->cl_xprt))
189                 clnt->cl_autobind = 1;
190
191         clnt->cl_timeout = xprt->timeout;
192         if (args->timeout != NULL) {
193                 memcpy(&clnt->cl_timeout_default, args->timeout,
194                                 sizeof(clnt->cl_timeout_default));
195                 clnt->cl_timeout = &clnt->cl_timeout_default;
196         }
197
198         clnt->cl_rtt = &clnt->cl_rtt_default;
199         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
200         clnt->cl_principal = NULL;
201         if (args->client_name) {
202                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
203                 if (!clnt->cl_principal)
204                         goto out_no_principal;
205         }
206
207         kref_init(&clnt->cl_kref);
208
209         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
210         if (err < 0)
211                 goto out_no_path;
212
213         auth = rpcauth_create(args->authflavor, clnt);
214         if (IS_ERR(auth)) {
215                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
216                                 args->authflavor);
217                 err = PTR_ERR(auth);
218                 goto out_no_auth;
219         }
220
221         /* save the nodename */
222         clnt->cl_nodelen = strlen(init_utsname()->nodename);
223         if (clnt->cl_nodelen > UNX_MAXNODENAME)
224                 clnt->cl_nodelen = UNX_MAXNODENAME;
225         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
226         rpc_register_client(clnt);
227         return clnt;
228
229 out_no_auth:
230         if (!IS_ERR(clnt->cl_dentry)) {
231                 rpc_rmdir(clnt->cl_dentry);
232                 rpc_put_mount();
233         }
234 out_no_path:
235         kfree(clnt->cl_principal);
236 out_no_principal:
237         rpc_free_iostats(clnt->cl_metrics);
238 out_no_stats:
239         if (clnt->cl_server != clnt->cl_inline_name)
240                 kfree(clnt->cl_server);
241         kfree(clnt);
242 out_err:
243         xprt_put(xprt);
244 out_no_xprt:
245         rpciod_down();
246 out_no_rpciod:
247         return ERR_PTR(err);
248 }
249
250 /*
251  * rpc_create - create an RPC client and transport with one call
252  * @args: rpc_clnt create argument structure
253  *
254  * Creates and initializes an RPC transport and an RPC client.
255  *
256  * It can ping the server in order to determine if it is up, and to see if
257  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
258  * this behavior so asynchronous tasks can also use rpc_create.
259  */
260 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
261 {
262         struct rpc_xprt *xprt;
263         struct rpc_clnt *clnt;
264         struct xprt_create xprtargs = {
265                 .ident = args->protocol,
266                 .srcaddr = args->saddress,
267                 .dstaddr = args->address,
268                 .addrlen = args->addrsize,
269         };
270         char servername[48];
271
272         /*
273          * If the caller chooses not to specify a hostname, whip
274          * up a string representation of the passed-in address.
275          */
276         if (args->servername == NULL) {
277                 servername[0] = '\0';
278                 switch (args->address->sa_family) {
279                 case AF_INET: {
280                         struct sockaddr_in *sin =
281                                         (struct sockaddr_in *)args->address;
282                         snprintf(servername, sizeof(servername), "%pI4",
283                                  &sin->sin_addr.s_addr);
284                         break;
285                 }
286                 case AF_INET6: {
287                         struct sockaddr_in6 *sin =
288                                         (struct sockaddr_in6 *)args->address;
289                         snprintf(servername, sizeof(servername), "%pI6",
290                                  &sin->sin6_addr);
291                         break;
292                 }
293                 default:
294                         /* caller wants default server name, but
295                          * address family isn't recognized. */
296                         return ERR_PTR(-EINVAL);
297                 }
298                 args->servername = servername;
299         }
300
301         xprt = xprt_create_transport(&xprtargs);
302         if (IS_ERR(xprt))
303                 return (struct rpc_clnt *)xprt;
304
305         /*
306          * By default, kernel RPC client connects from a reserved port.
307          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
308          * but it is always enabled for rpciod, which handles the connect
309          * operation.
310          */
311         xprt->resvport = 1;
312         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
313                 xprt->resvport = 0;
314
315         clnt = rpc_new_client(args, xprt);
316         if (IS_ERR(clnt))
317                 return clnt;
318
319         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
320                 int err = rpc_ping(clnt, RPC_TASK_SOFT);
321                 if (err != 0) {
322                         rpc_shutdown_client(clnt);
323                         return ERR_PTR(err);
324                 }
325         }
326
327         clnt->cl_softrtry = 1;
328         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
329                 clnt->cl_softrtry = 0;
330
331         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
332                 clnt->cl_autobind = 1;
333         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
334                 clnt->cl_discrtry = 1;
335         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
336                 clnt->cl_chatty = 1;
337
338         return clnt;
339 }
340 EXPORT_SYMBOL_GPL(rpc_create);
341
342 /*
343  * This function clones the RPC client structure. It allows us to share the
344  * same transport while varying parameters such as the authentication
345  * flavour.
346  */
347 struct rpc_clnt *
348 rpc_clone_client(struct rpc_clnt *clnt)
349 {
350         struct rpc_clnt *new;
351         int err = -ENOMEM;
352
353         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
354         if (!new)
355                 goto out_no_clnt;
356         new->cl_parent = clnt;
357         /* Turn off autobind on clones */
358         new->cl_autobind = 0;
359         INIT_LIST_HEAD(&new->cl_tasks);
360         spin_lock_init(&new->cl_lock);
361         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
362         new->cl_metrics = rpc_alloc_iostats(clnt);
363         if (new->cl_metrics == NULL)
364                 goto out_no_stats;
365         if (clnt->cl_principal) {
366                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
367                 if (new->cl_principal == NULL)
368                         goto out_no_principal;
369         }
370         kref_init(&new->cl_kref);
371         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
372         if (err != 0)
373                 goto out_no_path;
374         if (new->cl_auth)
375                 atomic_inc(&new->cl_auth->au_count);
376         xprt_get(clnt->cl_xprt);
377         kref_get(&clnt->cl_kref);
378         rpc_register_client(new);
379         rpciod_up();
380         return new;
381 out_no_path:
382         kfree(new->cl_principal);
383 out_no_principal:
384         rpc_free_iostats(new->cl_metrics);
385 out_no_stats:
386         kfree(new);
387 out_no_clnt:
388         dprintk("RPC:       %s: returned error %d\n", __func__, err);
389         return ERR_PTR(err);
390 }
391 EXPORT_SYMBOL_GPL(rpc_clone_client);
392
393 /*
394  * Properly shut down an RPC client, terminating all outstanding
395  * requests.
396  */
397 void rpc_shutdown_client(struct rpc_clnt *clnt)
398 {
399         dprintk("RPC:       shutting down %s client for %s\n",
400                         clnt->cl_protname, clnt->cl_server);
401
402         while (!list_empty(&clnt->cl_tasks)) {
403                 rpc_killall_tasks(clnt);
404                 wait_event_timeout(destroy_wait,
405                         list_empty(&clnt->cl_tasks), 1*HZ);
406         }
407
408         rpc_release_client(clnt);
409 }
410 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
411
412 /*
413  * Free an RPC client
414  */
415 static void
416 rpc_free_client(struct kref *kref)
417 {
418         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
419
420         dprintk("RPC:       destroying %s client for %s\n",
421                         clnt->cl_protname, clnt->cl_server);
422         if (!IS_ERR(clnt->cl_dentry)) {
423                 rpc_rmdir(clnt->cl_dentry);
424                 rpc_put_mount();
425         }
426         if (clnt->cl_parent != clnt) {
427                 rpc_release_client(clnt->cl_parent);
428                 goto out_free;
429         }
430         if (clnt->cl_server != clnt->cl_inline_name)
431                 kfree(clnt->cl_server);
432 out_free:
433         rpc_unregister_client(clnt);
434         rpc_free_iostats(clnt->cl_metrics);
435         kfree(clnt->cl_principal);
436         clnt->cl_metrics = NULL;
437         xprt_put(clnt->cl_xprt);
438         rpciod_down();
439         kfree(clnt);
440 }
441
442 /*
443  * Free an RPC client
444  */
445 static void
446 rpc_free_auth(struct kref *kref)
447 {
448         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
449
450         if (clnt->cl_auth == NULL) {
451                 rpc_free_client(kref);
452                 return;
453         }
454
455         /*
456          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
457          *       release remaining GSS contexts. This mechanism ensures
458          *       that it can do so safely.
459          */
460         kref_init(kref);
461         rpcauth_release(clnt->cl_auth);
462         clnt->cl_auth = NULL;
463         kref_put(kref, rpc_free_client);
464 }
465
466 /*
467  * Release reference to the RPC client
468  */
469 void
470 rpc_release_client(struct rpc_clnt *clnt)
471 {
472         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
473
474         if (list_empty(&clnt->cl_tasks))
475                 wake_up(&destroy_wait);
476         kref_put(&clnt->cl_kref, rpc_free_auth);
477 }
478
479 /**
480  * rpc_bind_new_program - bind a new RPC program to an existing client
481  * @old: old rpc_client
482  * @program: rpc program to set
483  * @vers: rpc program version
484  *
485  * Clones the rpc client and sets up a new RPC program. This is mainly
486  * of use for enabling different RPC programs to share the same transport.
487  * The Sun NFSv2/v3 ACL protocol can do this.
488  */
489 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
490                                       struct rpc_program *program,
491                                       u32 vers)
492 {
493         struct rpc_clnt *clnt;
494         struct rpc_version *version;
495         int err;
496
497         BUG_ON(vers >= program->nrvers || !program->version[vers]);
498         version = program->version[vers];
499         clnt = rpc_clone_client(old);
500         if (IS_ERR(clnt))
501                 goto out;
502         clnt->cl_procinfo = version->procs;
503         clnt->cl_maxproc  = version->nrprocs;
504         clnt->cl_protname = program->name;
505         clnt->cl_prog     = program->number;
506         clnt->cl_vers     = version->number;
507         clnt->cl_stats    = program->stats;
508         err = rpc_ping(clnt, RPC_TASK_SOFT);
509         if (err != 0) {
510                 rpc_shutdown_client(clnt);
511                 clnt = ERR_PTR(err);
512         }
513 out:
514         return clnt;
515 }
516 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
517
518 /*
519  * Default callback for async RPC calls
520  */
521 static void
522 rpc_default_callback(struct rpc_task *task, void *data)
523 {
524 }
525
526 static const struct rpc_call_ops rpc_default_ops = {
527         .rpc_call_done = rpc_default_callback,
528 };
529
530 /**
531  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
532  * @task_setup_data: pointer to task initialisation data
533  */
534 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
535 {
536         struct rpc_task *task, *ret;
537
538         task = rpc_new_task(task_setup_data);
539         if (task == NULL) {
540                 rpc_release_calldata(task_setup_data->callback_ops,
541                                 task_setup_data->callback_data);
542                 ret = ERR_PTR(-ENOMEM);
543                 goto out;
544         }
545
546         if (task->tk_status != 0) {
547                 ret = ERR_PTR(task->tk_status);
548                 rpc_put_task(task);
549                 goto out;
550         }
551         atomic_inc(&task->tk_count);
552         rpc_execute(task);
553         ret = task;
554 out:
555         return ret;
556 }
557 EXPORT_SYMBOL_GPL(rpc_run_task);
558
559 /**
560  * rpc_call_sync - Perform a synchronous RPC call
561  * @clnt: pointer to RPC client
562  * @msg: RPC call parameters
563  * @flags: RPC call flags
564  */
565 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
566 {
567         struct rpc_task *task;
568         struct rpc_task_setup task_setup_data = {
569                 .rpc_client = clnt,
570                 .rpc_message = msg,
571                 .callback_ops = &rpc_default_ops,
572                 .flags = flags,
573         };
574         int status;
575
576         BUG_ON(flags & RPC_TASK_ASYNC);
577
578         task = rpc_run_task(&task_setup_data);
579         if (IS_ERR(task))
580                 return PTR_ERR(task);
581         status = task->tk_status;
582         rpc_put_task(task);
583         return status;
584 }
585 EXPORT_SYMBOL_GPL(rpc_call_sync);
586
587 /**
588  * rpc_call_async - Perform an asynchronous RPC call
589  * @clnt: pointer to RPC client
590  * @msg: RPC call parameters
591  * @flags: RPC call flags
592  * @tk_ops: RPC call ops
593  * @data: user call data
594  */
595 int
596 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
597                const struct rpc_call_ops *tk_ops, void *data)
598 {
599         struct rpc_task *task;
600         struct rpc_task_setup task_setup_data = {
601                 .rpc_client = clnt,
602                 .rpc_message = msg,
603                 .callback_ops = tk_ops,
604                 .callback_data = data,
605                 .flags = flags|RPC_TASK_ASYNC,
606         };
607
608         task = rpc_run_task(&task_setup_data);
609         if (IS_ERR(task))
610                 return PTR_ERR(task);
611         rpc_put_task(task);
612         return 0;
613 }
614 EXPORT_SYMBOL_GPL(rpc_call_async);
615
616 void
617 rpc_call_start(struct rpc_task *task)
618 {
619         task->tk_action = call_start;
620 }
621 EXPORT_SYMBOL_GPL(rpc_call_start);
622
623 /**
624  * rpc_peeraddr - extract remote peer address from clnt's xprt
625  * @clnt: RPC client structure
626  * @buf: target buffer
627  * @bufsize: length of target buffer
628  *
629  * Returns the number of bytes that are actually in the stored address.
630  */
631 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
632 {
633         size_t bytes;
634         struct rpc_xprt *xprt = clnt->cl_xprt;
635
636         bytes = sizeof(xprt->addr);
637         if (bytes > bufsize)
638                 bytes = bufsize;
639         memcpy(buf, &clnt->cl_xprt->addr, bytes);
640         return xprt->addrlen;
641 }
642 EXPORT_SYMBOL_GPL(rpc_peeraddr);
643
644 /**
645  * rpc_peeraddr2str - return remote peer address in printable format
646  * @clnt: RPC client structure
647  * @format: address format
648  *
649  */
650 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
651                              enum rpc_display_format_t format)
652 {
653         struct rpc_xprt *xprt = clnt->cl_xprt;
654
655         if (xprt->address_strings[format] != NULL)
656                 return xprt->address_strings[format];
657         else
658                 return "unprintable";
659 }
660 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
661
662 void
663 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
664 {
665         struct rpc_xprt *xprt = clnt->cl_xprt;
666         if (xprt->ops->set_buffer_size)
667                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
668 }
669 EXPORT_SYMBOL_GPL(rpc_setbufsize);
670
671 /*
672  * Return size of largest payload RPC client can support, in bytes
673  *
674  * For stream transports, this is one RPC record fragment (see RFC
675  * 1831), as we don't support multi-record requests yet.  For datagram
676  * transports, this is the size of an IP packet minus the IP, UDP, and
677  * RPC header sizes.
678  */
679 size_t rpc_max_payload(struct rpc_clnt *clnt)
680 {
681         return clnt->cl_xprt->max_payload;
682 }
683 EXPORT_SYMBOL_GPL(rpc_max_payload);
684
685 /**
686  * rpc_force_rebind - force transport to check that remote port is unchanged
687  * @clnt: client to rebind
688  *
689  */
690 void rpc_force_rebind(struct rpc_clnt *clnt)
691 {
692         if (clnt->cl_autobind)
693                 xprt_clear_bound(clnt->cl_xprt);
694 }
695 EXPORT_SYMBOL_GPL(rpc_force_rebind);
696
697 /*
698  * Restart an (async) RPC call. Usually called from within the
699  * exit handler.
700  */
701 void
702 rpc_restart_call(struct rpc_task *task)
703 {
704         if (RPC_ASSASSINATED(task))
705                 return;
706
707         task->tk_action = call_start;
708 }
709 EXPORT_SYMBOL_GPL(rpc_restart_call);
710
711 #ifdef RPC_DEBUG
712 static const char *rpc_proc_name(const struct rpc_task *task)
713 {
714         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
715
716         if (proc) {
717                 if (proc->p_name)
718                         return proc->p_name;
719                 else
720                         return "NULL";
721         } else
722                 return "no proc";
723 }
724 #endif
725
726 /*
727  * 0.  Initial state
728  *
729  *     Other FSM states can be visited zero or more times, but
730  *     this state is visited exactly once for each RPC.
731  */
732 static void
733 call_start(struct rpc_task *task)
734 {
735         struct rpc_clnt *clnt = task->tk_client;
736
737         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
738                         clnt->cl_protname, clnt->cl_vers,
739                         rpc_proc_name(task),
740                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
741
742         /* Increment call count */
743         task->tk_msg.rpc_proc->p_count++;
744         clnt->cl_stats->rpccnt++;
745         task->tk_action = call_reserve;
746 }
747
748 /*
749  * 1.   Reserve an RPC call slot
750  */
751 static void
752 call_reserve(struct rpc_task *task)
753 {
754         dprint_status(task);
755
756         if (!rpcauth_uptodatecred(task)) {
757                 task->tk_action = call_refresh;
758                 return;
759         }
760
761         task->tk_status  = 0;
762         task->tk_action  = call_reserveresult;
763         xprt_reserve(task);
764 }
765
766 /*
767  * 1b.  Grok the result of xprt_reserve()
768  */
769 static void
770 call_reserveresult(struct rpc_task *task)
771 {
772         int status = task->tk_status;
773
774         dprint_status(task);
775
776         /*
777          * After a call to xprt_reserve(), we must have either
778          * a request slot or else an error status.
779          */
780         task->tk_status = 0;
781         if (status >= 0) {
782                 if (task->tk_rqstp) {
783                         task->tk_action = call_allocate;
784                         return;
785                 }
786
787                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
788                                 __func__, status);
789                 rpc_exit(task, -EIO);
790                 return;
791         }
792
793         /*
794          * Even though there was an error, we may have acquired
795          * a request slot somehow.  Make sure not to leak it.
796          */
797         if (task->tk_rqstp) {
798                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
799                                 __func__, status);
800                 xprt_release(task);
801         }
802
803         switch (status) {
804         case -EAGAIN:   /* woken up; retry */
805                 task->tk_action = call_reserve;
806                 return;
807         case -EIO:      /* probably a shutdown */
808                 break;
809         default:
810                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
811                                 __func__, status);
812                 break;
813         }
814         rpc_exit(task, status);
815 }
816
817 /*
818  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
819  *      (Note: buffer memory is freed in xprt_release).
820  */
821 static void
822 call_allocate(struct rpc_task *task)
823 {
824         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
825         struct rpc_rqst *req = task->tk_rqstp;
826         struct rpc_xprt *xprt = task->tk_xprt;
827         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
828
829         dprint_status(task);
830
831         task->tk_status = 0;
832         task->tk_action = call_bind;
833
834         if (req->rq_buffer)
835                 return;
836
837         if (proc->p_proc != 0) {
838                 BUG_ON(proc->p_arglen == 0);
839                 if (proc->p_decode != NULL)
840                         BUG_ON(proc->p_replen == 0);
841         }
842
843         /*
844          * Calculate the size (in quads) of the RPC call
845          * and reply headers, and convert both values
846          * to byte sizes.
847          */
848         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
849         req->rq_callsize <<= 2;
850         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
851         req->rq_rcvsize <<= 2;
852
853         req->rq_buffer = xprt->ops->buf_alloc(task,
854                                         req->rq_callsize + req->rq_rcvsize);
855         if (req->rq_buffer != NULL)
856                 return;
857
858         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
859
860         if (RPC_IS_ASYNC(task) || !signalled()) {
861                 task->tk_action = call_allocate;
862                 rpc_delay(task, HZ>>4);
863                 return;
864         }
865
866         rpc_exit(task, -ERESTARTSYS);
867 }
868
869 static inline int
870 rpc_task_need_encode(struct rpc_task *task)
871 {
872         return task->tk_rqstp->rq_snd_buf.len == 0;
873 }
874
875 static inline void
876 rpc_task_force_reencode(struct rpc_task *task)
877 {
878         task->tk_rqstp->rq_snd_buf.len = 0;
879 }
880
881 static inline void
882 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
883 {
884         buf->head[0].iov_base = start;
885         buf->head[0].iov_len = len;
886         buf->tail[0].iov_len = 0;
887         buf->page_len = 0;
888         buf->flags = 0;
889         buf->len = 0;
890         buf->buflen = len;
891 }
892
893 /*
894  * 3.   Encode arguments of an RPC call
895  */
896 static void
897 rpc_xdr_encode(struct rpc_task *task)
898 {
899         struct rpc_rqst *req = task->tk_rqstp;
900         kxdrproc_t      encode;
901         __be32          *p;
902
903         dprint_status(task);
904
905         rpc_xdr_buf_init(&req->rq_snd_buf,
906                          req->rq_buffer,
907                          req->rq_callsize);
908         rpc_xdr_buf_init(&req->rq_rcv_buf,
909                          (char *)req->rq_buffer + req->rq_callsize,
910                          req->rq_rcvsize);
911
912         p = rpc_encode_header(task);
913         if (p == NULL) {
914                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
915                 rpc_exit(task, -EIO);
916                 return;
917         }
918
919         encode = task->tk_msg.rpc_proc->p_encode;
920         if (encode == NULL)
921                 return;
922
923         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
924                         task->tk_msg.rpc_argp);
925 }
926
927 /*
928  * 4.   Get the server port number if not yet set
929  */
930 static void
931 call_bind(struct rpc_task *task)
932 {
933         struct rpc_xprt *xprt = task->tk_xprt;
934
935         dprint_status(task);
936
937         task->tk_action = call_connect;
938         if (!xprt_bound(xprt)) {
939                 task->tk_action = call_bind_status;
940                 task->tk_timeout = xprt->bind_timeout;
941                 xprt->ops->rpcbind(task);
942         }
943 }
944
945 /*
946  * 4a.  Sort out bind result
947  */
948 static void
949 call_bind_status(struct rpc_task *task)
950 {
951         int status = -EIO;
952
953         if (task->tk_status >= 0) {
954                 dprint_status(task);
955                 task->tk_status = 0;
956                 task->tk_action = call_connect;
957                 return;
958         }
959
960         switch (task->tk_status) {
961         case -ENOMEM:
962                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
963                 rpc_delay(task, HZ >> 2);
964                 goto retry_timeout;
965         case -EACCES:
966                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
967                                 "unavailable\n", task->tk_pid);
968                 /* fail immediately if this is an RPC ping */
969                 if (task->tk_msg.rpc_proc->p_proc == 0) {
970                         status = -EOPNOTSUPP;
971                         break;
972                 }
973                 rpc_delay(task, 3*HZ);
974                 goto retry_timeout;
975         case -ETIMEDOUT:
976                 dprintk("RPC: %5u rpcbind request timed out\n",
977                                 task->tk_pid);
978                 goto retry_timeout;
979         case -EPFNOSUPPORT:
980                 /* server doesn't support any rpcbind version we know of */
981                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
982                                 task->tk_pid);
983                 break;
984         case -EPROTONOSUPPORT:
985                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
986                                 task->tk_pid);
987                 task->tk_status = 0;
988                 task->tk_action = call_bind;
989                 return;
990         default:
991                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
992                                 task->tk_pid, -task->tk_status);
993         }
994
995         rpc_exit(task, status);
996         return;
997
998 retry_timeout:
999         task->tk_action = call_timeout;
1000 }
1001
1002 /*
1003  * 4b.  Connect to the RPC server
1004  */
1005 static void
1006 call_connect(struct rpc_task *task)
1007 {
1008         struct rpc_xprt *xprt = task->tk_xprt;
1009
1010         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1011                         task->tk_pid, xprt,
1012                         (xprt_connected(xprt) ? "is" : "is not"));
1013
1014         task->tk_action = call_transmit;
1015         if (!xprt_connected(xprt)) {
1016                 task->tk_action = call_connect_status;
1017                 if (task->tk_status < 0)
1018                         return;
1019                 xprt_connect(task);
1020         }
1021 }
1022
1023 /*
1024  * 4c.  Sort out connect result
1025  */
1026 static void
1027 call_connect_status(struct rpc_task *task)
1028 {
1029         struct rpc_clnt *clnt = task->tk_client;
1030         int status = task->tk_status;
1031
1032         dprint_status(task);
1033
1034         task->tk_status = 0;
1035         if (status >= 0) {
1036                 clnt->cl_stats->netreconn++;
1037                 task->tk_action = call_transmit;
1038                 return;
1039         }
1040
1041         /* Something failed: remote service port may have changed */
1042         rpc_force_rebind(clnt);
1043
1044         switch (status) {
1045         case -ENOTCONN:
1046         case -EAGAIN:
1047                 task->tk_action = call_bind;
1048                 if (!RPC_IS_SOFT(task))
1049                         return;
1050                 /* if soft mounted, test if we've timed out */
1051         case -ETIMEDOUT:
1052                 task->tk_action = call_timeout;
1053                 return;
1054         }
1055         rpc_exit(task, -EIO);
1056 }
1057
1058 /*
1059  * 5.   Transmit the RPC request, and wait for reply
1060  */
1061 static void
1062 call_transmit(struct rpc_task *task)
1063 {
1064         dprint_status(task);
1065
1066         task->tk_action = call_status;
1067         if (task->tk_status < 0)
1068                 return;
1069         task->tk_status = xprt_prepare_transmit(task);
1070         if (task->tk_status != 0)
1071                 return;
1072         task->tk_action = call_transmit_status;
1073         /* Encode here so that rpcsec_gss can use correct sequence number. */
1074         if (rpc_task_need_encode(task)) {
1075                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1076                 rpc_xdr_encode(task);
1077                 /* Did the encode result in an error condition? */
1078                 if (task->tk_status != 0) {
1079                         /* Was the error nonfatal? */
1080                         if (task->tk_status == -EAGAIN)
1081                                 rpc_delay(task, HZ >> 4);
1082                         else
1083                                 rpc_exit(task, task->tk_status);
1084                         return;
1085                 }
1086         }
1087         xprt_transmit(task);
1088         if (task->tk_status < 0)
1089                 return;
1090         /*
1091          * On success, ensure that we call xprt_end_transmit() before sleeping
1092          * in order to allow access to the socket to other RPC requests.
1093          */
1094         call_transmit_status(task);
1095         if (task->tk_msg.rpc_proc->p_decode != NULL)
1096                 return;
1097         task->tk_action = rpc_exit_task;
1098         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1099 }
1100
1101 /*
1102  * 5a.  Handle cleanup after a transmission
1103  */
1104 static void
1105 call_transmit_status(struct rpc_task *task)
1106 {
1107         task->tk_action = call_status;
1108         /*
1109          * Special case: if we've been waiting on the socket's write_space()
1110          * callback, then don't call xprt_end_transmit().
1111          */
1112         if (task->tk_status == -EAGAIN)
1113                 return;
1114         xprt_end_transmit(task);
1115         rpc_task_force_reencode(task);
1116 }
1117
1118 /*
1119  * 6.   Sort out the RPC call status
1120  */
1121 static void
1122 call_status(struct rpc_task *task)
1123 {
1124         struct rpc_clnt *clnt = task->tk_client;
1125         struct rpc_rqst *req = task->tk_rqstp;
1126         int             status;
1127
1128         if (req->rq_received > 0 && !req->rq_bytes_sent)
1129                 task->tk_status = req->rq_received;
1130
1131         dprint_status(task);
1132
1133         status = task->tk_status;
1134         if (status >= 0) {
1135                 task->tk_action = call_decode;
1136                 return;
1137         }
1138
1139         task->tk_status = 0;
1140         switch(status) {
1141         case -EHOSTDOWN:
1142         case -EHOSTUNREACH:
1143         case -ENETUNREACH:
1144                 /*
1145                  * Delay any retries for 3 seconds, then handle as if it
1146                  * were a timeout.
1147                  */
1148                 rpc_delay(task, 3*HZ);
1149         case -ETIMEDOUT:
1150                 task->tk_action = call_timeout;
1151                 if (task->tk_client->cl_discrtry)
1152                         xprt_conditional_disconnect(task->tk_xprt,
1153                                         req->rq_connect_cookie);
1154                 break;
1155         case -ECONNREFUSED:
1156         case -ENOTCONN:
1157                 rpc_force_rebind(clnt);
1158                 task->tk_action = call_bind;
1159                 break;
1160         case -EAGAIN:
1161                 task->tk_action = call_transmit;
1162                 break;
1163         case -EIO:
1164                 /* shutdown or soft timeout */
1165                 rpc_exit(task, status);
1166                 break;
1167         default:
1168                 if (clnt->cl_chatty)
1169                         printk("%s: RPC call returned error %d\n",
1170                                clnt->cl_protname, -status);
1171                 rpc_exit(task, status);
1172         }
1173 }
1174
1175 /*
1176  * 6a.  Handle RPC timeout
1177  *      We do not release the request slot, so we keep using the
1178  *      same XID for all retransmits.
1179  */
1180 static void
1181 call_timeout(struct rpc_task *task)
1182 {
1183         struct rpc_clnt *clnt = task->tk_client;
1184
1185         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1186                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1187                 goto retry;
1188         }
1189
1190         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1191         task->tk_timeouts++;
1192
1193         if (RPC_IS_SOFT(task)) {
1194                 if (clnt->cl_chatty)
1195                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1196                                 clnt->cl_protname, clnt->cl_server);
1197                 rpc_exit(task, -EIO);
1198                 return;
1199         }
1200
1201         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1202                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1203                 if (clnt->cl_chatty)
1204                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1205                         clnt->cl_protname, clnt->cl_server);
1206         }
1207         rpc_force_rebind(clnt);
1208         /*
1209          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1210          * event? RFC2203 requires the server to drop all such requests.
1211          */
1212         rpcauth_invalcred(task);
1213
1214 retry:
1215         clnt->cl_stats->rpcretrans++;
1216         task->tk_action = call_bind;
1217         task->tk_status = 0;
1218 }
1219
1220 /*
1221  * 7.   Decode the RPC reply
1222  */
1223 static void
1224 call_decode(struct rpc_task *task)
1225 {
1226         struct rpc_clnt *clnt = task->tk_client;
1227         struct rpc_rqst *req = task->tk_rqstp;
1228         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1229         __be32          *p;
1230
1231         dprintk("RPC: %5u call_decode (status %d)\n",
1232                         task->tk_pid, task->tk_status);
1233
1234         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1235                 if (clnt->cl_chatty)
1236                         printk(KERN_NOTICE "%s: server %s OK\n",
1237                                 clnt->cl_protname, clnt->cl_server);
1238                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1239         }
1240
1241         /*
1242          * Ensure that we see all writes made by xprt_complete_rqst()
1243          * before it changed req->rq_received.
1244          */
1245         smp_rmb();
1246         req->rq_rcv_buf.len = req->rq_private_buf.len;
1247
1248         /* Check that the softirq receive buffer is valid */
1249         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1250                                 sizeof(req->rq_rcv_buf)) != 0);
1251
1252         if (req->rq_rcv_buf.len < 12) {
1253                 if (!RPC_IS_SOFT(task)) {
1254                         task->tk_action = call_bind;
1255                         clnt->cl_stats->rpcretrans++;
1256                         goto out_retry;
1257                 }
1258                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1259                                 clnt->cl_protname, task->tk_status);
1260                 task->tk_action = call_timeout;
1261                 goto out_retry;
1262         }
1263
1264         p = rpc_verify_header(task);
1265         if (IS_ERR(p)) {
1266                 if (p == ERR_PTR(-EAGAIN))
1267                         goto out_retry;
1268                 return;
1269         }
1270
1271         task->tk_action = rpc_exit_task;
1272
1273         if (decode) {
1274                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1275                                                       task->tk_msg.rpc_resp);
1276         }
1277         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1278                         task->tk_status);
1279         return;
1280 out_retry:
1281         task->tk_status = 0;
1282         /* Note: rpc_verify_header() may have freed the RPC slot */
1283         if (task->tk_rqstp == req) {
1284                 req->rq_received = req->rq_rcv_buf.len = 0;
1285                 if (task->tk_client->cl_discrtry)
1286                         xprt_conditional_disconnect(task->tk_xprt,
1287                                         req->rq_connect_cookie);
1288         }
1289 }
1290
1291 /*
1292  * 8.   Refresh the credentials if rejected by the server
1293  */
1294 static void
1295 call_refresh(struct rpc_task *task)
1296 {
1297         dprint_status(task);
1298
1299         task->tk_action = call_refreshresult;
1300         task->tk_status = 0;
1301         task->tk_client->cl_stats->rpcauthrefresh++;
1302         rpcauth_refreshcred(task);
1303 }
1304
1305 /*
1306  * 8a.  Process the results of a credential refresh
1307  */
1308 static void
1309 call_refreshresult(struct rpc_task *task)
1310 {
1311         int status = task->tk_status;
1312
1313         dprint_status(task);
1314
1315         task->tk_status = 0;
1316         task->tk_action = call_reserve;
1317         if (status >= 0 && rpcauth_uptodatecred(task))
1318                 return;
1319         if (status == -EACCES) {
1320                 rpc_exit(task, -EACCES);
1321                 return;
1322         }
1323         task->tk_action = call_refresh;
1324         if (status != -ETIMEDOUT)
1325                 rpc_delay(task, 3*HZ);
1326         return;
1327 }
1328
1329 static __be32 *
1330 rpc_encode_header(struct rpc_task *task)
1331 {
1332         struct rpc_clnt *clnt = task->tk_client;
1333         struct rpc_rqst *req = task->tk_rqstp;
1334         __be32          *p = req->rq_svec[0].iov_base;
1335
1336         /* FIXME: check buffer size? */
1337
1338         p = xprt_skip_transport_header(task->tk_xprt, p);
1339         *p++ = req->rq_xid;             /* XID */
1340         *p++ = htonl(RPC_CALL);         /* CALL */
1341         *p++ = htonl(RPC_VERSION);      /* RPC version */
1342         *p++ = htonl(clnt->cl_prog);    /* program number */
1343         *p++ = htonl(clnt->cl_vers);    /* program version */
1344         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1345         p = rpcauth_marshcred(task, p);
1346         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1347         return p;
1348 }
1349
1350 static __be32 *
1351 rpc_verify_header(struct rpc_task *task)
1352 {
1353         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1354         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1355         __be32  *p = iov->iov_base;
1356         u32 n;
1357         int error = -EACCES;
1358
1359         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1360                 /* RFC-1014 says that the representation of XDR data must be a
1361                  * multiple of four bytes
1362                  * - if it isn't pointer subtraction in the NFS client may give
1363                  *   undefined results
1364                  */
1365                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1366                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1367                        task->tk_rqstp->rq_rcv_buf.len);
1368                 goto out_eio;
1369         }
1370         if ((len -= 3) < 0)
1371                 goto out_overflow;
1372         p += 1; /* skip XID */
1373
1374         if ((n = ntohl(*p++)) != RPC_REPLY) {
1375                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1376                                 task->tk_pid, __func__, n);
1377                 goto out_garbage;
1378         }
1379         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1380                 if (--len < 0)
1381                         goto out_overflow;
1382                 switch ((n = ntohl(*p++))) {
1383                         case RPC_AUTH_ERROR:
1384                                 break;
1385                         case RPC_MISMATCH:
1386                                 dprintk("RPC: %5u %s: RPC call version "
1387                                                 "mismatch!\n",
1388                                                 task->tk_pid, __func__);
1389                                 error = -EPROTONOSUPPORT;
1390                                 goto out_err;
1391                         default:
1392                                 dprintk("RPC: %5u %s: RPC call rejected, "
1393                                                 "unknown error: %x\n",
1394                                                 task->tk_pid, __func__, n);
1395                                 goto out_eio;
1396                 }
1397                 if (--len < 0)
1398                         goto out_overflow;
1399                 switch ((n = ntohl(*p++))) {
1400                 case RPC_AUTH_REJECTEDCRED:
1401                 case RPC_AUTH_REJECTEDVERF:
1402                 case RPCSEC_GSS_CREDPROBLEM:
1403                 case RPCSEC_GSS_CTXPROBLEM:
1404                         if (!task->tk_cred_retry)
1405                                 break;
1406                         task->tk_cred_retry--;
1407                         dprintk("RPC: %5u %s: retry stale creds\n",
1408                                         task->tk_pid, __func__);
1409                         rpcauth_invalcred(task);
1410                         /* Ensure we obtain a new XID! */
1411                         xprt_release(task);
1412                         task->tk_action = call_refresh;
1413                         goto out_retry;
1414                 case RPC_AUTH_BADCRED:
1415                 case RPC_AUTH_BADVERF:
1416                         /* possibly garbled cred/verf? */
1417                         if (!task->tk_garb_retry)
1418                                 break;
1419                         task->tk_garb_retry--;
1420                         dprintk("RPC: %5u %s: retry garbled creds\n",
1421                                         task->tk_pid, __func__);
1422                         task->tk_action = call_bind;
1423                         goto out_retry;
1424                 case RPC_AUTH_TOOWEAK:
1425                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1426                                "authentication.\n", task->tk_client->cl_server);
1427                         break;
1428                 default:
1429                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1430                                         task->tk_pid, __func__, n);
1431                         error = -EIO;
1432                 }
1433                 dprintk("RPC: %5u %s: call rejected %d\n",
1434                                 task->tk_pid, __func__, n);
1435                 goto out_err;
1436         }
1437         if (!(p = rpcauth_checkverf(task, p))) {
1438                 dprintk("RPC: %5u %s: auth check failed\n",
1439                                 task->tk_pid, __func__);
1440                 goto out_garbage;               /* bad verifier, retry */
1441         }
1442         len = p - (__be32 *)iov->iov_base - 1;
1443         if (len < 0)
1444                 goto out_overflow;
1445         switch ((n = ntohl(*p++))) {
1446         case RPC_SUCCESS:
1447                 return p;
1448         case RPC_PROG_UNAVAIL:
1449                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1450                                 task->tk_pid, __func__,
1451                                 (unsigned int)task->tk_client->cl_prog,
1452                                 task->tk_client->cl_server);
1453                 error = -EPFNOSUPPORT;
1454                 goto out_err;
1455         case RPC_PROG_MISMATCH:
1456                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1457                                 "server %s\n", task->tk_pid, __func__,
1458                                 (unsigned int)task->tk_client->cl_prog,
1459                                 (unsigned int)task->tk_client->cl_vers,
1460                                 task->tk_client->cl_server);
1461                 error = -EPROTONOSUPPORT;
1462                 goto out_err;
1463         case RPC_PROC_UNAVAIL:
1464                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1465                                 "version %u on server %s\n",
1466                                 task->tk_pid, __func__,
1467                                 rpc_proc_name(task),
1468                                 task->tk_client->cl_prog,
1469                                 task->tk_client->cl_vers,
1470                                 task->tk_client->cl_server);
1471                 error = -EOPNOTSUPP;
1472                 goto out_err;
1473         case RPC_GARBAGE_ARGS:
1474                 dprintk("RPC: %5u %s: server saw garbage\n",
1475                                 task->tk_pid, __func__);
1476                 break;                  /* retry */
1477         default:
1478                 dprintk("RPC: %5u %s: server accept status: %x\n",
1479                                 task->tk_pid, __func__, n);
1480                 /* Also retry */
1481         }
1482
1483 out_garbage:
1484         task->tk_client->cl_stats->rpcgarbage++;
1485         if (task->tk_garb_retry) {
1486                 task->tk_garb_retry--;
1487                 dprintk("RPC: %5u %s: retrying\n",
1488                                 task->tk_pid, __func__);
1489                 task->tk_action = call_bind;
1490 out_retry:
1491                 return ERR_PTR(-EAGAIN);
1492         }
1493 out_eio:
1494         error = -EIO;
1495 out_err:
1496         rpc_exit(task, error);
1497         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1498                         __func__, error);
1499         return ERR_PTR(error);
1500 out_overflow:
1501         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1502                         __func__);
1503         goto out_garbage;
1504 }
1505
1506 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1507 {
1508         return 0;
1509 }
1510
1511 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1512 {
1513         return 0;
1514 }
1515
1516 static struct rpc_procinfo rpcproc_null = {
1517         .p_encode = rpcproc_encode_null,
1518         .p_decode = rpcproc_decode_null,
1519 };
1520
1521 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1522 {
1523         struct rpc_message msg = {
1524                 .rpc_proc = &rpcproc_null,
1525         };
1526         int err;
1527         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1528         err = rpc_call_sync(clnt, &msg, flags);
1529         put_rpccred(msg.rpc_cred);
1530         return err;
1531 }
1532
1533 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1534 {
1535         struct rpc_message msg = {
1536                 .rpc_proc = &rpcproc_null,
1537                 .rpc_cred = cred,
1538         };
1539         struct rpc_task_setup task_setup_data = {
1540                 .rpc_client = clnt,
1541                 .rpc_message = &msg,
1542                 .callback_ops = &rpc_default_ops,
1543                 .flags = flags,
1544         };
1545         return rpc_run_task(&task_setup_data);
1546 }
1547 EXPORT_SYMBOL_GPL(rpc_call_null);
1548
1549 #ifdef RPC_DEBUG
1550 static void rpc_show_header(void)
1551 {
1552         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1553                 "-timeout ---ops--\n");
1554 }
1555
1556 static void rpc_show_task(const struct rpc_clnt *clnt,
1557                           const struct rpc_task *task)
1558 {
1559         const char *rpc_waitq = "none";
1560         char *p, action[KSYM_SYMBOL_LEN];
1561
1562         if (RPC_IS_QUEUED(task))
1563                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1564
1565         /* map tk_action pointer to a function name; then trim off
1566          * the "+0x0 [sunrpc]" */
1567         sprint_symbol(action, (unsigned long)task->tk_action);
1568         p = strchr(action, '+');
1569         if (p)
1570                 *p = '\0';
1571
1572         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1573                 task->tk_pid, task->tk_flags, task->tk_status,
1574                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1575                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1576                 action, rpc_waitq);
1577 }
1578
1579 void rpc_show_tasks(void)
1580 {
1581         struct rpc_clnt *clnt;
1582         struct rpc_task *task;
1583         int header = 0;
1584
1585         spin_lock(&rpc_client_lock);
1586         list_for_each_entry(clnt, &all_clients, cl_clients) {
1587                 spin_lock(&clnt->cl_lock);
1588                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1589                         if (!header) {
1590                                 rpc_show_header();
1591                                 header++;
1592                         }
1593                         rpc_show_task(clnt, task);
1594                 }
1595                 spin_unlock(&clnt->cl_lock);
1596         }
1597         spin_unlock(&rpc_client_lock);
1598 }
1599 #endif