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