ebfcf9b8990918d65db492add437ae46fa259e30
[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/kallsyms.h>
29 #include <linux/mm.h>
30 #include <linux/slab.h>
31 #include <linux/utsname.h>
32 #include <linux/workqueue.h>
33 #include <linux/in6.h>
34
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/rpc_pipe_fs.h>
37 #include <linux/sunrpc/metrics.h>
38 #include <linux/sunrpc/bc_xprt.h>
39
40 #include "sunrpc.h"
41
42 #ifdef RPC_DEBUG
43 # define RPCDBG_FACILITY        RPCDBG_CALL
44 #endif
45
46 #define dprint_status(t)                                        \
47         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
48                         __func__, t->tk_status)
49
50 /*
51  * All RPC clients are linked into this list
52  */
53 static LIST_HEAD(all_clients);
54 static DEFINE_SPINLOCK(rpc_client_lock);
55
56 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
57
58
59 static void     call_start(struct rpc_task *task);
60 static void     call_reserve(struct rpc_task *task);
61 static void     call_reserveresult(struct rpc_task *task);
62 static void     call_allocate(struct rpc_task *task);
63 static void     call_decode(struct rpc_task *task);
64 static void     call_bind(struct rpc_task *task);
65 static void     call_bind_status(struct rpc_task *task);
66 static void     call_transmit(struct rpc_task *task);
67 #if defined(CONFIG_NFS_V4_1)
68 static void     call_bc_transmit(struct rpc_task *task);
69 #endif /* CONFIG_NFS_V4_1 */
70 static void     call_status(struct rpc_task *task);
71 static void     call_transmit_status(struct rpc_task *task);
72 static void     call_refresh(struct rpc_task *task);
73 static void     call_refreshresult(struct rpc_task *task);
74 static void     call_timeout(struct rpc_task *task);
75 static void     call_connect(struct rpc_task *task);
76 static void     call_connect_status(struct rpc_task *task);
77
78 static __be32   *rpc_encode_header(struct rpc_task *task);
79 static __be32   *rpc_verify_header(struct rpc_task *task);
80 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
81
82 static void rpc_register_client(struct rpc_clnt *clnt)
83 {
84         spin_lock(&rpc_client_lock);
85         list_add(&clnt->cl_clients, &all_clients);
86         spin_unlock(&rpc_client_lock);
87 }
88
89 static void rpc_unregister_client(struct rpc_clnt *clnt)
90 {
91         spin_lock(&rpc_client_lock);
92         list_del(&clnt->cl_clients);
93         spin_unlock(&rpc_client_lock);
94 }
95
96 static int
97 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
98 {
99         static uint32_t clntid;
100         int error;
101
102         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
103         clnt->cl_dentry = ERR_PTR(-ENOENT);
104         if (dir_name == NULL)
105                 return 0;
106
107         clnt->cl_vfsmnt = rpc_get_mount();
108         if (IS_ERR(clnt->cl_vfsmnt))
109                 return PTR_ERR(clnt->cl_vfsmnt);
110
111         for (;;) {
112                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
113                                 "%s/clnt%x", dir_name,
114                                 (unsigned int)clntid++);
115                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
116                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
117                 if (!IS_ERR(clnt->cl_dentry))
118                         return 0;
119                 error = PTR_ERR(clnt->cl_dentry);
120                 if (error != -EEXIST) {
121                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
122                                         clnt->cl_pathname, error);
123                         rpc_put_mount();
124                         return error;
125                 }
126         }
127 }
128
129 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
130 {
131         struct rpc_program      *program = args->program;
132         struct rpc_version      *version;
133         struct rpc_clnt         *clnt = NULL;
134         struct rpc_auth         *auth;
135         int err;
136         size_t len;
137
138         /* sanity check the name before trying to print it */
139         err = -EINVAL;
140         len = strlen(args->servername);
141         if (len > RPC_MAXNETNAMELEN)
142                 goto out_no_rpciod;
143         len++;
144
145         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
146                         program->name, args->servername, xprt);
147
148         err = rpciod_up();
149         if (err)
150                 goto out_no_rpciod;
151         err = -EINVAL;
152         if (!xprt)
153                 goto out_no_xprt;
154
155         if (args->version >= program->nrvers)
156                 goto out_err;
157         version = program->version[args->version];
158         if (version == NULL)
159                 goto out_err;
160
161         err = -ENOMEM;
162         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
163         if (!clnt)
164                 goto out_err;
165         clnt->cl_parent = clnt;
166
167         clnt->cl_server = clnt->cl_inline_name;
168         if (len > sizeof(clnt->cl_inline_name)) {
169                 char *buf = kmalloc(len, GFP_KERNEL);
170                 if (buf != NULL)
171                         clnt->cl_server = buf;
172                 else
173                         len = sizeof(clnt->cl_inline_name);
174         }
175         strlcpy(clnt->cl_server, args->servername, len);
176
177         clnt->cl_xprt     = xprt;
178         clnt->cl_procinfo = version->procs;
179         clnt->cl_maxproc  = version->nrprocs;
180         clnt->cl_protname = program->name;
181         clnt->cl_prog     = args->prognumber ? : program->number;
182         clnt->cl_vers     = version->number;
183         clnt->cl_stats    = program->stats;
184         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
185         err = -ENOMEM;
186         if (clnt->cl_metrics == NULL)
187                 goto out_no_stats;
188         clnt->cl_program  = program;
189         INIT_LIST_HEAD(&clnt->cl_tasks);
190         spin_lock_init(&clnt->cl_lock);
191
192         if (!xprt_bound(clnt->cl_xprt))
193                 clnt->cl_autobind = 1;
194
195         clnt->cl_timeout = xprt->timeout;
196         if (args->timeout != NULL) {
197                 memcpy(&clnt->cl_timeout_default, args->timeout,
198                                 sizeof(clnt->cl_timeout_default));
199                 clnt->cl_timeout = &clnt->cl_timeout_default;
200         }
201
202         clnt->cl_rtt = &clnt->cl_rtt_default;
203         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
204         clnt->cl_principal = NULL;
205         if (args->client_name) {
206                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
207                 if (!clnt->cl_principal)
208                         goto out_no_principal;
209         }
210
211         kref_init(&clnt->cl_kref);
212
213         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
214         if (err < 0)
215                 goto out_no_path;
216
217         auth = rpcauth_create(args->authflavor, clnt);
218         if (IS_ERR(auth)) {
219                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
220                                 args->authflavor);
221                 err = PTR_ERR(auth);
222                 goto out_no_auth;
223         }
224
225         /* save the nodename */
226         clnt->cl_nodelen = strlen(init_utsname()->nodename);
227         if (clnt->cl_nodelen > UNX_MAXNODENAME)
228                 clnt->cl_nodelen = UNX_MAXNODENAME;
229         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
230         rpc_register_client(clnt);
231         return clnt;
232
233 out_no_auth:
234         if (!IS_ERR(clnt->cl_dentry)) {
235                 rpc_rmdir(clnt->cl_dentry);
236                 rpc_put_mount();
237         }
238 out_no_path:
239         kfree(clnt->cl_principal);
240 out_no_principal:
241         rpc_free_iostats(clnt->cl_metrics);
242 out_no_stats:
243         if (clnt->cl_server != clnt->cl_inline_name)
244                 kfree(clnt->cl_server);
245         kfree(clnt);
246 out_err:
247         xprt_put(xprt);
248 out_no_xprt:
249         rpciod_down();
250 out_no_rpciod:
251         return ERR_PTR(err);
252 }
253
254 /*
255  * rpc_create - create an RPC client and transport with one call
256  * @args: rpc_clnt create argument structure
257  *
258  * Creates and initializes an RPC transport and an RPC client.
259  *
260  * It can ping the server in order to determine if it is up, and to see if
261  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
262  * this behavior so asynchronous tasks can also use rpc_create.
263  */
264 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
265 {
266         struct rpc_xprt *xprt;
267         struct rpc_clnt *clnt;
268         struct xprt_create xprtargs = {
269                 .ident = args->protocol,
270                 .srcaddr = args->saddress,
271                 .dstaddr = args->address,
272                 .addrlen = args->addrsize,
273         };
274         char servername[48];
275
276         /*
277          * If the caller chooses not to specify a hostname, whip
278          * up a string representation of the passed-in address.
279          */
280         if (args->servername == NULL) {
281                 servername[0] = '\0';
282                 switch (args->address->sa_family) {
283                 case AF_INET: {
284                         struct sockaddr_in *sin =
285                                         (struct sockaddr_in *)args->address;
286                         snprintf(servername, sizeof(servername), "%pI4",
287                                  &sin->sin_addr.s_addr);
288                         break;
289                 }
290                 case AF_INET6: {
291                         struct sockaddr_in6 *sin =
292                                         (struct sockaddr_in6 *)args->address;
293                         snprintf(servername, sizeof(servername), "%pI6",
294                                  &sin->sin6_addr);
295                         break;
296                 }
297                 default:
298                         /* caller wants default server name, but
299                          * address family isn't recognized. */
300                         return ERR_PTR(-EINVAL);
301                 }
302                 args->servername = servername;
303         }
304
305         xprt = xprt_create_transport(&xprtargs);
306         if (IS_ERR(xprt))
307                 return (struct rpc_clnt *)xprt;
308
309         /*
310          * By default, kernel RPC client connects from a reserved port.
311          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
312          * but it is always enabled for rpciod, which handles the connect
313          * operation.
314          */
315         xprt->resvport = 1;
316         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
317                 xprt->resvport = 0;
318
319         clnt = rpc_new_client(args, xprt);
320         if (IS_ERR(clnt))
321                 return clnt;
322
323         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
324                 int err = rpc_ping(clnt, RPC_TASK_SOFT);
325                 if (err != 0) {
326                         rpc_shutdown_client(clnt);
327                         return ERR_PTR(err);
328                 }
329         }
330
331         clnt->cl_softrtry = 1;
332         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
333                 clnt->cl_softrtry = 0;
334
335         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
336                 clnt->cl_autobind = 1;
337         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
338                 clnt->cl_discrtry = 1;
339         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
340                 clnt->cl_chatty = 1;
341
342         return clnt;
343 }
344 EXPORT_SYMBOL_GPL(rpc_create);
345
346 /*
347  * This function clones the RPC client structure. It allows us to share the
348  * same transport while varying parameters such as the authentication
349  * flavour.
350  */
351 struct rpc_clnt *
352 rpc_clone_client(struct rpc_clnt *clnt)
353 {
354         struct rpc_clnt *new;
355         int err = -ENOMEM;
356
357         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
358         if (!new)
359                 goto out_no_clnt;
360         new->cl_parent = clnt;
361         /* Turn off autobind on clones */
362         new->cl_autobind = 0;
363         INIT_LIST_HEAD(&new->cl_tasks);
364         spin_lock_init(&new->cl_lock);
365         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
366         new->cl_metrics = rpc_alloc_iostats(clnt);
367         if (new->cl_metrics == NULL)
368                 goto out_no_stats;
369         if (clnt->cl_principal) {
370                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
371                 if (new->cl_principal == NULL)
372                         goto out_no_principal;
373         }
374         kref_init(&new->cl_kref);
375         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
376         if (err != 0)
377                 goto out_no_path;
378         if (new->cl_auth)
379                 atomic_inc(&new->cl_auth->au_count);
380         xprt_get(clnt->cl_xprt);
381         kref_get(&clnt->cl_kref);
382         rpc_register_client(new);
383         rpciod_up();
384         return new;
385 out_no_path:
386         kfree(new->cl_principal);
387 out_no_principal:
388         rpc_free_iostats(new->cl_metrics);
389 out_no_stats:
390         kfree(new);
391 out_no_clnt:
392         dprintk("RPC:       %s: returned error %d\n", __func__, err);
393         return ERR_PTR(err);
394 }
395 EXPORT_SYMBOL_GPL(rpc_clone_client);
396
397 /*
398  * Properly shut down an RPC client, terminating all outstanding
399  * requests.
400  */
401 void rpc_shutdown_client(struct rpc_clnt *clnt)
402 {
403         dprintk("RPC:       shutting down %s client for %s\n",
404                         clnt->cl_protname, clnt->cl_server);
405
406         while (!list_empty(&clnt->cl_tasks)) {
407                 rpc_killall_tasks(clnt);
408                 wait_event_timeout(destroy_wait,
409                         list_empty(&clnt->cl_tasks), 1*HZ);
410         }
411
412         rpc_release_client(clnt);
413 }
414 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
415
416 /*
417  * Free an RPC client
418  */
419 static void
420 rpc_free_client(struct kref *kref)
421 {
422         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
423
424         dprintk("RPC:       destroying %s client for %s\n",
425                         clnt->cl_protname, clnt->cl_server);
426         if (!IS_ERR(clnt->cl_dentry)) {
427                 rpc_rmdir(clnt->cl_dentry);
428                 rpc_put_mount();
429         }
430         if (clnt->cl_parent != clnt) {
431                 rpc_release_client(clnt->cl_parent);
432                 goto out_free;
433         }
434         if (clnt->cl_server != clnt->cl_inline_name)
435                 kfree(clnt->cl_server);
436 out_free:
437         rpc_unregister_client(clnt);
438         rpc_free_iostats(clnt->cl_metrics);
439         kfree(clnt->cl_principal);
440         clnt->cl_metrics = NULL;
441         xprt_put(clnt->cl_xprt);
442         rpciod_down();
443         kfree(clnt);
444 }
445
446 /*
447  * Free an RPC client
448  */
449 static void
450 rpc_free_auth(struct kref *kref)
451 {
452         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
453
454         if (clnt->cl_auth == NULL) {
455                 rpc_free_client(kref);
456                 return;
457         }
458
459         /*
460          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
461          *       release remaining GSS contexts. This mechanism ensures
462          *       that it can do so safely.
463          */
464         kref_init(kref);
465         rpcauth_release(clnt->cl_auth);
466         clnt->cl_auth = NULL;
467         kref_put(kref, rpc_free_client);
468 }
469
470 /*
471  * Release reference to the RPC client
472  */
473 void
474 rpc_release_client(struct rpc_clnt *clnt)
475 {
476         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
477
478         if (list_empty(&clnt->cl_tasks))
479                 wake_up(&destroy_wait);
480         kref_put(&clnt->cl_kref, rpc_free_auth);
481 }
482
483 /**
484  * rpc_bind_new_program - bind a new RPC program to an existing client
485  * @old: old rpc_client
486  * @program: rpc program to set
487  * @vers: rpc program version
488  *
489  * Clones the rpc client and sets up a new RPC program. This is mainly
490  * of use for enabling different RPC programs to share the same transport.
491  * The Sun NFSv2/v3 ACL protocol can do this.
492  */
493 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
494                                       struct rpc_program *program,
495                                       u32 vers)
496 {
497         struct rpc_clnt *clnt;
498         struct rpc_version *version;
499         int err;
500
501         BUG_ON(vers >= program->nrvers || !program->version[vers]);
502         version = program->version[vers];
503         clnt = rpc_clone_client(old);
504         if (IS_ERR(clnt))
505                 goto out;
506         clnt->cl_procinfo = version->procs;
507         clnt->cl_maxproc  = version->nrprocs;
508         clnt->cl_protname = program->name;
509         clnt->cl_prog     = program->number;
510         clnt->cl_vers     = version->number;
511         clnt->cl_stats    = program->stats;
512         err = rpc_ping(clnt, RPC_TASK_SOFT);
513         if (err != 0) {
514                 rpc_shutdown_client(clnt);
515                 clnt = ERR_PTR(err);
516         }
517 out:
518         return clnt;
519 }
520 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
521
522 /*
523  * Default callback for async RPC calls
524  */
525 static void
526 rpc_default_callback(struct rpc_task *task, void *data)
527 {
528 }
529
530 static const struct rpc_call_ops rpc_default_ops = {
531         .rpc_call_done = rpc_default_callback,
532 };
533
534 /**
535  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
536  * @task_setup_data: pointer to task initialisation data
537  */
538 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
539 {
540         struct rpc_task *task, *ret;
541
542         task = rpc_new_task(task_setup_data);
543         if (task == NULL) {
544                 rpc_release_calldata(task_setup_data->callback_ops,
545                                 task_setup_data->callback_data);
546                 ret = ERR_PTR(-ENOMEM);
547                 goto out;
548         }
549
550         if (task->tk_status != 0) {
551                 ret = ERR_PTR(task->tk_status);
552                 rpc_put_task(task);
553                 goto out;
554         }
555         atomic_inc(&task->tk_count);
556         rpc_execute(task);
557         ret = task;
558 out:
559         return ret;
560 }
561 EXPORT_SYMBOL_GPL(rpc_run_task);
562
563 /**
564  * rpc_call_sync - Perform a synchronous RPC call
565  * @clnt: pointer to RPC client
566  * @msg: RPC call parameters
567  * @flags: RPC call flags
568  */
569 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
570 {
571         struct rpc_task *task;
572         struct rpc_task_setup task_setup_data = {
573                 .rpc_client = clnt,
574                 .rpc_message = msg,
575                 .callback_ops = &rpc_default_ops,
576                 .flags = flags,
577         };
578         int status;
579
580         BUG_ON(flags & RPC_TASK_ASYNC);
581
582         task = rpc_run_task(&task_setup_data);
583         if (IS_ERR(task))
584                 return PTR_ERR(task);
585         status = task->tk_status;
586         rpc_put_task(task);
587         return status;
588 }
589 EXPORT_SYMBOL_GPL(rpc_call_sync);
590
591 /**
592  * rpc_call_async - Perform an asynchronous RPC call
593  * @clnt: pointer to RPC client
594  * @msg: RPC call parameters
595  * @flags: RPC call flags
596  * @tk_ops: RPC call ops
597  * @data: user call data
598  */
599 int
600 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
601                const struct rpc_call_ops *tk_ops, void *data)
602 {
603         struct rpc_task *task;
604         struct rpc_task_setup task_setup_data = {
605                 .rpc_client = clnt,
606                 .rpc_message = msg,
607                 .callback_ops = tk_ops,
608                 .callback_data = data,
609                 .flags = flags|RPC_TASK_ASYNC,
610         };
611
612         task = rpc_run_task(&task_setup_data);
613         if (IS_ERR(task))
614                 return PTR_ERR(task);
615         rpc_put_task(task);
616         return 0;
617 }
618 EXPORT_SYMBOL_GPL(rpc_call_async);
619
620 #if defined(CONFIG_NFS_V4_1)
621 /**
622  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
623  * rpc_execute against it
624  * @ops: RPC call ops
625  */
626 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
627                                         const struct rpc_call_ops *tk_ops)
628 {
629         struct rpc_task *task;
630         struct xdr_buf *xbufp = &req->rq_snd_buf;
631         struct rpc_task_setup task_setup_data = {
632                 .callback_ops = tk_ops,
633         };
634
635         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
636         /*
637          * Create an rpc_task to send the data
638          */
639         task = rpc_new_task(&task_setup_data);
640         if (!task) {
641                 xprt_free_bc_request(req);
642                 goto out;
643         }
644         task->tk_rqstp = req;
645
646         /*
647          * Set up the xdr_buf length.
648          * This also indicates that the buffer is XDR encoded already.
649          */
650         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
651                         xbufp->tail[0].iov_len;
652
653         task->tk_action = call_bc_transmit;
654         atomic_inc(&task->tk_count);
655         BUG_ON(atomic_read(&task->tk_count) != 2);
656         rpc_execute(task);
657
658 out:
659         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
660         return task;
661 }
662 #endif /* CONFIG_NFS_V4_1 */
663
664 void
665 rpc_call_start(struct rpc_task *task)
666 {
667         task->tk_action = call_start;
668 }
669 EXPORT_SYMBOL_GPL(rpc_call_start);
670
671 /**
672  * rpc_peeraddr - extract remote peer address from clnt's xprt
673  * @clnt: RPC client structure
674  * @buf: target buffer
675  * @bufsize: length of target buffer
676  *
677  * Returns the number of bytes that are actually in the stored address.
678  */
679 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
680 {
681         size_t bytes;
682         struct rpc_xprt *xprt = clnt->cl_xprt;
683
684         bytes = sizeof(xprt->addr);
685         if (bytes > bufsize)
686                 bytes = bufsize;
687         memcpy(buf, &clnt->cl_xprt->addr, bytes);
688         return xprt->addrlen;
689 }
690 EXPORT_SYMBOL_GPL(rpc_peeraddr);
691
692 /**
693  * rpc_peeraddr2str - return remote peer address in printable format
694  * @clnt: RPC client structure
695  * @format: address format
696  *
697  */
698 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
699                              enum rpc_display_format_t format)
700 {
701         struct rpc_xprt *xprt = clnt->cl_xprt;
702
703         if (xprt->address_strings[format] != NULL)
704                 return xprt->address_strings[format];
705         else
706                 return "unprintable";
707 }
708 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
709
710 void
711 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
712 {
713         struct rpc_xprt *xprt = clnt->cl_xprt;
714         if (xprt->ops->set_buffer_size)
715                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
716 }
717 EXPORT_SYMBOL_GPL(rpc_setbufsize);
718
719 /*
720  * Return size of largest payload RPC client can support, in bytes
721  *
722  * For stream transports, this is one RPC record fragment (see RFC
723  * 1831), as we don't support multi-record requests yet.  For datagram
724  * transports, this is the size of an IP packet minus the IP, UDP, and
725  * RPC header sizes.
726  */
727 size_t rpc_max_payload(struct rpc_clnt *clnt)
728 {
729         return clnt->cl_xprt->max_payload;
730 }
731 EXPORT_SYMBOL_GPL(rpc_max_payload);
732
733 /**
734  * rpc_force_rebind - force transport to check that remote port is unchanged
735  * @clnt: client to rebind
736  *
737  */
738 void rpc_force_rebind(struct rpc_clnt *clnt)
739 {
740         if (clnt->cl_autobind)
741                 xprt_clear_bound(clnt->cl_xprt);
742 }
743 EXPORT_SYMBOL_GPL(rpc_force_rebind);
744
745 /*
746  * Restart an (async) RPC call from the call_prepare state.
747  * Usually called from within the exit handler.
748  */
749 void
750 rpc_restart_call_prepare(struct rpc_task *task)
751 {
752         if (RPC_ASSASSINATED(task))
753                 return;
754         task->tk_action = rpc_prepare_task;
755 }
756 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
757
758 /*
759  * Restart an (async) RPC call. Usually called from within the
760  * exit handler.
761  */
762 void
763 rpc_restart_call(struct rpc_task *task)
764 {
765         if (RPC_ASSASSINATED(task))
766                 return;
767
768         task->tk_action = call_start;
769 }
770 EXPORT_SYMBOL_GPL(rpc_restart_call);
771
772 #ifdef RPC_DEBUG
773 static const char *rpc_proc_name(const struct rpc_task *task)
774 {
775         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
776
777         if (proc) {
778                 if (proc->p_name)
779                         return proc->p_name;
780                 else
781                         return "NULL";
782         } else
783                 return "no proc";
784 }
785 #endif
786
787 /*
788  * 0.  Initial state
789  *
790  *     Other FSM states can be visited zero or more times, but
791  *     this state is visited exactly once for each RPC.
792  */
793 static void
794 call_start(struct rpc_task *task)
795 {
796         struct rpc_clnt *clnt = task->tk_client;
797
798         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
799                         clnt->cl_protname, clnt->cl_vers,
800                         rpc_proc_name(task),
801                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
802
803         /* Increment call count */
804         task->tk_msg.rpc_proc->p_count++;
805         clnt->cl_stats->rpccnt++;
806         task->tk_action = call_reserve;
807 }
808
809 /*
810  * 1.   Reserve an RPC call slot
811  */
812 static void
813 call_reserve(struct rpc_task *task)
814 {
815         dprint_status(task);
816
817         if (!rpcauth_uptodatecred(task)) {
818                 task->tk_action = call_refresh;
819                 return;
820         }
821
822         task->tk_status  = 0;
823         task->tk_action  = call_reserveresult;
824         xprt_reserve(task);
825 }
826
827 /*
828  * 1b.  Grok the result of xprt_reserve()
829  */
830 static void
831 call_reserveresult(struct rpc_task *task)
832 {
833         int status = task->tk_status;
834
835         dprint_status(task);
836
837         /*
838          * After a call to xprt_reserve(), we must have either
839          * a request slot or else an error status.
840          */
841         task->tk_status = 0;
842         if (status >= 0) {
843                 if (task->tk_rqstp) {
844                         task->tk_action = call_allocate;
845                         return;
846                 }
847
848                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
849                                 __func__, status);
850                 rpc_exit(task, -EIO);
851                 return;
852         }
853
854         /*
855          * Even though there was an error, we may have acquired
856          * a request slot somehow.  Make sure not to leak it.
857          */
858         if (task->tk_rqstp) {
859                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
860                                 __func__, status);
861                 xprt_release(task);
862         }
863
864         switch (status) {
865         case -EAGAIN:   /* woken up; retry */
866                 task->tk_action = call_reserve;
867                 return;
868         case -EIO:      /* probably a shutdown */
869                 break;
870         default:
871                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
872                                 __func__, status);
873                 break;
874         }
875         rpc_exit(task, status);
876 }
877
878 /*
879  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
880  *      (Note: buffer memory is freed in xprt_release).
881  */
882 static void
883 call_allocate(struct rpc_task *task)
884 {
885         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
886         struct rpc_rqst *req = task->tk_rqstp;
887         struct rpc_xprt *xprt = task->tk_xprt;
888         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
889
890         dprint_status(task);
891
892         task->tk_status = 0;
893         task->tk_action = call_bind;
894
895         if (req->rq_buffer)
896                 return;
897
898         if (proc->p_proc != 0) {
899                 BUG_ON(proc->p_arglen == 0);
900                 if (proc->p_decode != NULL)
901                         BUG_ON(proc->p_replen == 0);
902         }
903
904         /*
905          * Calculate the size (in quads) of the RPC call
906          * and reply headers, and convert both values
907          * to byte sizes.
908          */
909         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
910         req->rq_callsize <<= 2;
911         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
912         req->rq_rcvsize <<= 2;
913
914         req->rq_buffer = xprt->ops->buf_alloc(task,
915                                         req->rq_callsize + req->rq_rcvsize);
916         if (req->rq_buffer != NULL)
917                 return;
918
919         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
920
921         if (RPC_IS_ASYNC(task) || !signalled()) {
922                 task->tk_action = call_allocate;
923                 rpc_delay(task, HZ>>4);
924                 return;
925         }
926
927         rpc_exit(task, -ERESTARTSYS);
928 }
929
930 static inline int
931 rpc_task_need_encode(struct rpc_task *task)
932 {
933         return task->tk_rqstp->rq_snd_buf.len == 0;
934 }
935
936 static inline void
937 rpc_task_force_reencode(struct rpc_task *task)
938 {
939         task->tk_rqstp->rq_snd_buf.len = 0;
940 }
941
942 static inline void
943 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
944 {
945         buf->head[0].iov_base = start;
946         buf->head[0].iov_len = len;
947         buf->tail[0].iov_len = 0;
948         buf->page_len = 0;
949         buf->flags = 0;
950         buf->len = 0;
951         buf->buflen = len;
952 }
953
954 /*
955  * 3.   Encode arguments of an RPC call
956  */
957 static void
958 rpc_xdr_encode(struct rpc_task *task)
959 {
960         struct rpc_rqst *req = task->tk_rqstp;
961         kxdrproc_t      encode;
962         __be32          *p;
963
964         dprint_status(task);
965
966         rpc_xdr_buf_init(&req->rq_snd_buf,
967                          req->rq_buffer,
968                          req->rq_callsize);
969         rpc_xdr_buf_init(&req->rq_rcv_buf,
970                          (char *)req->rq_buffer + req->rq_callsize,
971                          req->rq_rcvsize);
972
973         p = rpc_encode_header(task);
974         if (p == NULL) {
975                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
976                 rpc_exit(task, -EIO);
977                 return;
978         }
979
980         encode = task->tk_msg.rpc_proc->p_encode;
981         if (encode == NULL)
982                 return;
983
984         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
985                         task->tk_msg.rpc_argp);
986 }
987
988 /*
989  * 4.   Get the server port number if not yet set
990  */
991 static void
992 call_bind(struct rpc_task *task)
993 {
994         struct rpc_xprt *xprt = task->tk_xprt;
995
996         dprint_status(task);
997
998         task->tk_action = call_connect;
999         if (!xprt_bound(xprt)) {
1000                 task->tk_action = call_bind_status;
1001                 task->tk_timeout = xprt->bind_timeout;
1002                 xprt->ops->rpcbind(task);
1003         }
1004 }
1005
1006 /*
1007  * 4a.  Sort out bind result
1008  */
1009 static void
1010 call_bind_status(struct rpc_task *task)
1011 {
1012         int status = -EIO;
1013
1014         if (task->tk_status >= 0) {
1015                 dprint_status(task);
1016                 task->tk_status = 0;
1017                 task->tk_action = call_connect;
1018                 return;
1019         }
1020
1021         switch (task->tk_status) {
1022         case -ENOMEM:
1023                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1024                 rpc_delay(task, HZ >> 2);
1025                 goto retry_timeout;
1026         case -EACCES:
1027                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1028                                 "unavailable\n", task->tk_pid);
1029                 /* fail immediately if this is an RPC ping */
1030                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1031                         status = -EOPNOTSUPP;
1032                         break;
1033                 }
1034                 rpc_delay(task, 3*HZ);
1035                 goto retry_timeout;
1036         case -ETIMEDOUT:
1037                 dprintk("RPC: %5u rpcbind request timed out\n",
1038                                 task->tk_pid);
1039                 goto retry_timeout;
1040         case -EPFNOSUPPORT:
1041                 /* server doesn't support any rpcbind version we know of */
1042                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
1043                                 task->tk_pid);
1044                 break;
1045         case -EPROTONOSUPPORT:
1046                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1047                                 task->tk_pid);
1048                 task->tk_status = 0;
1049                 task->tk_action = call_bind;
1050                 return;
1051         default:
1052                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1053                                 task->tk_pid, -task->tk_status);
1054         }
1055
1056         rpc_exit(task, status);
1057         return;
1058
1059 retry_timeout:
1060         task->tk_action = call_timeout;
1061 }
1062
1063 /*
1064  * 4b.  Connect to the RPC server
1065  */
1066 static void
1067 call_connect(struct rpc_task *task)
1068 {
1069         struct rpc_xprt *xprt = task->tk_xprt;
1070
1071         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1072                         task->tk_pid, xprt,
1073                         (xprt_connected(xprt) ? "is" : "is not"));
1074
1075         task->tk_action = call_transmit;
1076         if (!xprt_connected(xprt)) {
1077                 task->tk_action = call_connect_status;
1078                 if (task->tk_status < 0)
1079                         return;
1080                 xprt_connect(task);
1081         }
1082 }
1083
1084 /*
1085  * 4c.  Sort out connect result
1086  */
1087 static void
1088 call_connect_status(struct rpc_task *task)
1089 {
1090         struct rpc_clnt *clnt = task->tk_client;
1091         int status = task->tk_status;
1092
1093         dprint_status(task);
1094
1095         task->tk_status = 0;
1096         if (status >= 0 || status == -EAGAIN) {
1097                 clnt->cl_stats->netreconn++;
1098                 task->tk_action = call_transmit;
1099                 return;
1100         }
1101
1102         switch (status) {
1103                 /* if soft mounted, test if we've timed out */
1104         case -ETIMEDOUT:
1105                 task->tk_action = call_timeout;
1106                 break;
1107         default:
1108                 rpc_exit(task, -EIO);
1109         }
1110 }
1111
1112 /*
1113  * 5.   Transmit the RPC request, and wait for reply
1114  */
1115 static void
1116 call_transmit(struct rpc_task *task)
1117 {
1118         dprint_status(task);
1119
1120         task->tk_action = call_status;
1121         if (task->tk_status < 0)
1122                 return;
1123         task->tk_status = xprt_prepare_transmit(task);
1124         if (task->tk_status != 0)
1125                 return;
1126         task->tk_action = call_transmit_status;
1127         /* Encode here so that rpcsec_gss can use correct sequence number. */
1128         if (rpc_task_need_encode(task)) {
1129                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1130                 rpc_xdr_encode(task);
1131                 /* Did the encode result in an error condition? */
1132                 if (task->tk_status != 0) {
1133                         /* Was the error nonfatal? */
1134                         if (task->tk_status == -EAGAIN)
1135                                 rpc_delay(task, HZ >> 4);
1136                         else
1137                                 rpc_exit(task, task->tk_status);
1138                         return;
1139                 }
1140         }
1141         xprt_transmit(task);
1142         if (task->tk_status < 0)
1143                 return;
1144         /*
1145          * On success, ensure that we call xprt_end_transmit() before sleeping
1146          * in order to allow access to the socket to other RPC requests.
1147          */
1148         call_transmit_status(task);
1149         if (rpc_reply_expected(task))
1150                 return;
1151         task->tk_action = rpc_exit_task;
1152         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1153 }
1154
1155 /*
1156  * 5a.  Handle cleanup after a transmission
1157  */
1158 static void
1159 call_transmit_status(struct rpc_task *task)
1160 {
1161         task->tk_action = call_status;
1162         switch (task->tk_status) {
1163         case -EAGAIN:
1164                 break;
1165         default:
1166                 xprt_end_transmit(task);
1167                 /*
1168                  * Special cases: if we've been waiting on the
1169                  * socket's write_space() callback, or if the
1170                  * socket just returned a connection error,
1171                  * then hold onto the transport lock.
1172                  */
1173         case -ECONNREFUSED:
1174         case -ECONNRESET:
1175         case -ENOTCONN:
1176         case -EHOSTDOWN:
1177         case -EHOSTUNREACH:
1178         case -ENETUNREACH:
1179         case -EPIPE:
1180                 rpc_task_force_reencode(task);
1181         }
1182 }
1183
1184 #if defined(CONFIG_NFS_V4_1)
1185 /*
1186  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1187  * addition, disconnect on connectivity errors.
1188  */
1189 static void
1190 call_bc_transmit(struct rpc_task *task)
1191 {
1192         struct rpc_rqst *req = task->tk_rqstp;
1193
1194         BUG_ON(task->tk_status != 0);
1195         task->tk_status = xprt_prepare_transmit(task);
1196         if (task->tk_status == -EAGAIN) {
1197                 /*
1198                  * Could not reserve the transport. Try again after the
1199                  * transport is released.
1200                  */
1201                 task->tk_status = 0;
1202                 task->tk_action = call_bc_transmit;
1203                 return;
1204         }
1205
1206         task->tk_action = rpc_exit_task;
1207         if (task->tk_status < 0) {
1208                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1209                         "error: %d\n", task->tk_status);
1210                 return;
1211         }
1212
1213         xprt_transmit(task);
1214         xprt_end_transmit(task);
1215         dprint_status(task);
1216         switch (task->tk_status) {
1217         case 0:
1218                 /* Success */
1219                 break;
1220         case -EHOSTDOWN:
1221         case -EHOSTUNREACH:
1222         case -ENETUNREACH:
1223         case -ETIMEDOUT:
1224                 /*
1225                  * Problem reaching the server.  Disconnect and let the
1226                  * forechannel reestablish the connection.  The server will
1227                  * have to retransmit the backchannel request and we'll
1228                  * reprocess it.  Since these ops are idempotent, there's no
1229                  * need to cache our reply at this time.
1230                  */
1231                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1232                         "error: %d\n", task->tk_status);
1233                 xprt_conditional_disconnect(task->tk_xprt,
1234                         req->rq_connect_cookie);
1235                 break;
1236         default:
1237                 /*
1238                  * We were unable to reply and will have to drop the
1239                  * request.  The server should reconnect and retransmit.
1240                  */
1241                 BUG_ON(task->tk_status == -EAGAIN);
1242                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1243                         "error: %d\n", task->tk_status);
1244                 break;
1245         }
1246         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1247 }
1248 #endif /* CONFIG_NFS_V4_1 */
1249
1250 /*
1251  * 6.   Sort out the RPC call status
1252  */
1253 static void
1254 call_status(struct rpc_task *task)
1255 {
1256         struct rpc_clnt *clnt = task->tk_client;
1257         struct rpc_rqst *req = task->tk_rqstp;
1258         int             status;
1259
1260         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1261                 task->tk_status = req->rq_reply_bytes_recvd;
1262
1263         dprint_status(task);
1264
1265         status = task->tk_status;
1266         if (status >= 0) {
1267                 task->tk_action = call_decode;
1268                 return;
1269         }
1270
1271         task->tk_status = 0;
1272         switch(status) {
1273         case -EHOSTDOWN:
1274         case -EHOSTUNREACH:
1275         case -ENETUNREACH:
1276                 /*
1277                  * Delay any retries for 3 seconds, then handle as if it
1278                  * were a timeout.
1279                  */
1280                 rpc_delay(task, 3*HZ);
1281         case -ETIMEDOUT:
1282                 task->tk_action = call_timeout;
1283                 if (task->tk_client->cl_discrtry)
1284                         xprt_conditional_disconnect(task->tk_xprt,
1285                                         req->rq_connect_cookie);
1286                 break;
1287         case -ECONNRESET:
1288         case -ECONNREFUSED:
1289                 rpc_force_rebind(clnt);
1290                 rpc_delay(task, 3*HZ);
1291         case -EPIPE:
1292         case -ENOTCONN:
1293                 task->tk_action = call_bind;
1294                 break;
1295         case -EAGAIN:
1296                 task->tk_action = call_transmit;
1297                 break;
1298         case -EIO:
1299                 /* shutdown or soft timeout */
1300                 rpc_exit(task, status);
1301                 break;
1302         default:
1303                 if (clnt->cl_chatty)
1304                         printk("%s: RPC call returned error %d\n",
1305                                clnt->cl_protname, -status);
1306                 rpc_exit(task, status);
1307         }
1308 }
1309
1310 /*
1311  * 6a.  Handle RPC timeout
1312  *      We do not release the request slot, so we keep using the
1313  *      same XID for all retransmits.
1314  */
1315 static void
1316 call_timeout(struct rpc_task *task)
1317 {
1318         struct rpc_clnt *clnt = task->tk_client;
1319
1320         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1321                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1322                 goto retry;
1323         }
1324
1325         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1326         task->tk_timeouts++;
1327
1328         if (RPC_IS_SOFT(task)) {
1329                 if (clnt->cl_chatty)
1330                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1331                                 clnt->cl_protname, clnt->cl_server);
1332                 rpc_exit(task, -EIO);
1333                 return;
1334         }
1335
1336         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1337                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1338                 if (clnt->cl_chatty)
1339                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1340                         clnt->cl_protname, clnt->cl_server);
1341         }
1342         rpc_force_rebind(clnt);
1343         /*
1344          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1345          * event? RFC2203 requires the server to drop all such requests.
1346          */
1347         rpcauth_invalcred(task);
1348
1349 retry:
1350         clnt->cl_stats->rpcretrans++;
1351         task->tk_action = call_bind;
1352         task->tk_status = 0;
1353 }
1354
1355 /*
1356  * 7.   Decode the RPC reply
1357  */
1358 static void
1359 call_decode(struct rpc_task *task)
1360 {
1361         struct rpc_clnt *clnt = task->tk_client;
1362         struct rpc_rqst *req = task->tk_rqstp;
1363         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1364         __be32          *p;
1365
1366         dprintk("RPC: %5u call_decode (status %d)\n",
1367                         task->tk_pid, task->tk_status);
1368
1369         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1370                 if (clnt->cl_chatty)
1371                         printk(KERN_NOTICE "%s: server %s OK\n",
1372                                 clnt->cl_protname, clnt->cl_server);
1373                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1374         }
1375
1376         /*
1377          * Ensure that we see all writes made by xprt_complete_rqst()
1378          * before it changed req->rq_reply_bytes_recvd.
1379          */
1380         smp_rmb();
1381         req->rq_rcv_buf.len = req->rq_private_buf.len;
1382
1383         /* Check that the softirq receive buffer is valid */
1384         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1385                                 sizeof(req->rq_rcv_buf)) != 0);
1386
1387         if (req->rq_rcv_buf.len < 12) {
1388                 if (!RPC_IS_SOFT(task)) {
1389                         task->tk_action = call_bind;
1390                         clnt->cl_stats->rpcretrans++;
1391                         goto out_retry;
1392                 }
1393                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1394                                 clnt->cl_protname, task->tk_status);
1395                 task->tk_action = call_timeout;
1396                 goto out_retry;
1397         }
1398
1399         p = rpc_verify_header(task);
1400         if (IS_ERR(p)) {
1401                 if (p == ERR_PTR(-EAGAIN))
1402                         goto out_retry;
1403                 return;
1404         }
1405
1406         task->tk_action = rpc_exit_task;
1407
1408         if (decode) {
1409                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1410                                                       task->tk_msg.rpc_resp);
1411         }
1412         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1413                         task->tk_status);
1414         return;
1415 out_retry:
1416         task->tk_status = 0;
1417         /* Note: rpc_verify_header() may have freed the RPC slot */
1418         if (task->tk_rqstp == req) {
1419                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1420                 if (task->tk_client->cl_discrtry)
1421                         xprt_conditional_disconnect(task->tk_xprt,
1422                                         req->rq_connect_cookie);
1423         }
1424 }
1425
1426 /*
1427  * 8.   Refresh the credentials if rejected by the server
1428  */
1429 static void
1430 call_refresh(struct rpc_task *task)
1431 {
1432         dprint_status(task);
1433
1434         task->tk_action = call_refreshresult;
1435         task->tk_status = 0;
1436         task->tk_client->cl_stats->rpcauthrefresh++;
1437         rpcauth_refreshcred(task);
1438 }
1439
1440 /*
1441  * 8a.  Process the results of a credential refresh
1442  */
1443 static void
1444 call_refreshresult(struct rpc_task *task)
1445 {
1446         int status = task->tk_status;
1447
1448         dprint_status(task);
1449
1450         task->tk_status = 0;
1451         task->tk_action = call_reserve;
1452         if (status >= 0 && rpcauth_uptodatecred(task))
1453                 return;
1454         if (status == -EACCES) {
1455                 rpc_exit(task, -EACCES);
1456                 return;
1457         }
1458         task->tk_action = call_refresh;
1459         if (status != -ETIMEDOUT)
1460                 rpc_delay(task, 3*HZ);
1461         return;
1462 }
1463
1464 static __be32 *
1465 rpc_encode_header(struct rpc_task *task)
1466 {
1467         struct rpc_clnt *clnt = task->tk_client;
1468         struct rpc_rqst *req = task->tk_rqstp;
1469         __be32          *p = req->rq_svec[0].iov_base;
1470
1471         /* FIXME: check buffer size? */
1472
1473         p = xprt_skip_transport_header(task->tk_xprt, p);
1474         *p++ = req->rq_xid;             /* XID */
1475         *p++ = htonl(RPC_CALL);         /* CALL */
1476         *p++ = htonl(RPC_VERSION);      /* RPC version */
1477         *p++ = htonl(clnt->cl_prog);    /* program number */
1478         *p++ = htonl(clnt->cl_vers);    /* program version */
1479         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1480         p = rpcauth_marshcred(task, p);
1481         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1482         return p;
1483 }
1484
1485 static __be32 *
1486 rpc_verify_header(struct rpc_task *task)
1487 {
1488         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1489         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1490         __be32  *p = iov->iov_base;
1491         u32 n;
1492         int error = -EACCES;
1493
1494         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1495                 /* RFC-1014 says that the representation of XDR data must be a
1496                  * multiple of four bytes
1497                  * - if it isn't pointer subtraction in the NFS client may give
1498                  *   undefined results
1499                  */
1500                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1501                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1502                        task->tk_rqstp->rq_rcv_buf.len);
1503                 goto out_eio;
1504         }
1505         if ((len -= 3) < 0)
1506                 goto out_overflow;
1507
1508         p += 1; /* skip XID */
1509         if ((n = ntohl(*p++)) != RPC_REPLY) {
1510                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1511                         task->tk_pid, __func__, n);
1512                 goto out_garbage;
1513         }
1514
1515         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1516                 if (--len < 0)
1517                         goto out_overflow;
1518                 switch ((n = ntohl(*p++))) {
1519                         case RPC_AUTH_ERROR:
1520                                 break;
1521                         case RPC_MISMATCH:
1522                                 dprintk("RPC: %5u %s: RPC call version "
1523                                                 "mismatch!\n",
1524                                                 task->tk_pid, __func__);
1525                                 error = -EPROTONOSUPPORT;
1526                                 goto out_err;
1527                         default:
1528                                 dprintk("RPC: %5u %s: RPC call rejected, "
1529                                                 "unknown error: %x\n",
1530                                                 task->tk_pid, __func__, n);
1531                                 goto out_eio;
1532                 }
1533                 if (--len < 0)
1534                         goto out_overflow;
1535                 switch ((n = ntohl(*p++))) {
1536                 case RPC_AUTH_REJECTEDCRED:
1537                 case RPC_AUTH_REJECTEDVERF:
1538                 case RPCSEC_GSS_CREDPROBLEM:
1539                 case RPCSEC_GSS_CTXPROBLEM:
1540                         if (!task->tk_cred_retry)
1541                                 break;
1542                         task->tk_cred_retry--;
1543                         dprintk("RPC: %5u %s: retry stale creds\n",
1544                                         task->tk_pid, __func__);
1545                         rpcauth_invalcred(task);
1546                         /* Ensure we obtain a new XID! */
1547                         xprt_release(task);
1548                         task->tk_action = call_refresh;
1549                         goto out_retry;
1550                 case RPC_AUTH_BADCRED:
1551                 case RPC_AUTH_BADVERF:
1552                         /* possibly garbled cred/verf? */
1553                         if (!task->tk_garb_retry)
1554                                 break;
1555                         task->tk_garb_retry--;
1556                         dprintk("RPC: %5u %s: retry garbled creds\n",
1557                                         task->tk_pid, __func__);
1558                         task->tk_action = call_bind;
1559                         goto out_retry;
1560                 case RPC_AUTH_TOOWEAK:
1561                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1562                                "authentication.\n", task->tk_client->cl_server);
1563                         break;
1564                 default:
1565                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1566                                         task->tk_pid, __func__, n);
1567                         error = -EIO;
1568                 }
1569                 dprintk("RPC: %5u %s: call rejected %d\n",
1570                                 task->tk_pid, __func__, n);
1571                 goto out_err;
1572         }
1573         if (!(p = rpcauth_checkverf(task, p))) {
1574                 dprintk("RPC: %5u %s: auth check failed\n",
1575                                 task->tk_pid, __func__);
1576                 goto out_garbage;               /* bad verifier, retry */
1577         }
1578         len = p - (__be32 *)iov->iov_base - 1;
1579         if (len < 0)
1580                 goto out_overflow;
1581         switch ((n = ntohl(*p++))) {
1582         case RPC_SUCCESS:
1583                 return p;
1584         case RPC_PROG_UNAVAIL:
1585                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1586                                 task->tk_pid, __func__,
1587                                 (unsigned int)task->tk_client->cl_prog,
1588                                 task->tk_client->cl_server);
1589                 error = -EPFNOSUPPORT;
1590                 goto out_err;
1591         case RPC_PROG_MISMATCH:
1592                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1593                                 "server %s\n", task->tk_pid, __func__,
1594                                 (unsigned int)task->tk_client->cl_prog,
1595                                 (unsigned int)task->tk_client->cl_vers,
1596                                 task->tk_client->cl_server);
1597                 error = -EPROTONOSUPPORT;
1598                 goto out_err;
1599         case RPC_PROC_UNAVAIL:
1600                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1601                                 "version %u on server %s\n",
1602                                 task->tk_pid, __func__,
1603                                 rpc_proc_name(task),
1604                                 task->tk_client->cl_prog,
1605                                 task->tk_client->cl_vers,
1606                                 task->tk_client->cl_server);
1607                 error = -EOPNOTSUPP;
1608                 goto out_err;
1609         case RPC_GARBAGE_ARGS:
1610                 dprintk("RPC: %5u %s: server saw garbage\n",
1611                                 task->tk_pid, __func__);
1612                 break;                  /* retry */
1613         default:
1614                 dprintk("RPC: %5u %s: server accept status: %x\n",
1615                                 task->tk_pid, __func__, n);
1616                 /* Also retry */
1617         }
1618
1619 out_garbage:
1620         task->tk_client->cl_stats->rpcgarbage++;
1621         if (task->tk_garb_retry) {
1622                 task->tk_garb_retry--;
1623                 dprintk("RPC: %5u %s: retrying\n",
1624                                 task->tk_pid, __func__);
1625                 task->tk_action = call_bind;
1626 out_retry:
1627                 return ERR_PTR(-EAGAIN);
1628         }
1629 out_eio:
1630         error = -EIO;
1631 out_err:
1632         rpc_exit(task, error);
1633         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1634                         __func__, error);
1635         return ERR_PTR(error);
1636 out_overflow:
1637         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1638                         __func__);
1639         goto out_garbage;
1640 }
1641
1642 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1643 {
1644         return 0;
1645 }
1646
1647 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1648 {
1649         return 0;
1650 }
1651
1652 static struct rpc_procinfo rpcproc_null = {
1653         .p_encode = rpcproc_encode_null,
1654         .p_decode = rpcproc_decode_null,
1655 };
1656
1657 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1658 {
1659         struct rpc_message msg = {
1660                 .rpc_proc = &rpcproc_null,
1661         };
1662         int err;
1663         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1664         err = rpc_call_sync(clnt, &msg, flags);
1665         put_rpccred(msg.rpc_cred);
1666         return err;
1667 }
1668
1669 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1670 {
1671         struct rpc_message msg = {
1672                 .rpc_proc = &rpcproc_null,
1673                 .rpc_cred = cred,
1674         };
1675         struct rpc_task_setup task_setup_data = {
1676                 .rpc_client = clnt,
1677                 .rpc_message = &msg,
1678                 .callback_ops = &rpc_default_ops,
1679                 .flags = flags,
1680         };
1681         return rpc_run_task(&task_setup_data);
1682 }
1683 EXPORT_SYMBOL_GPL(rpc_call_null);
1684
1685 #ifdef RPC_DEBUG
1686 static void rpc_show_header(void)
1687 {
1688         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1689                 "-timeout ---ops--\n");
1690 }
1691
1692 static void rpc_show_task(const struct rpc_clnt *clnt,
1693                           const struct rpc_task *task)
1694 {
1695         const char *rpc_waitq = "none";
1696         char *p, action[KSYM_SYMBOL_LEN];
1697
1698         if (RPC_IS_QUEUED(task))
1699                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1700
1701         /* map tk_action pointer to a function name; then trim off
1702          * the "+0x0 [sunrpc]" */
1703         sprint_symbol(action, (unsigned long)task->tk_action);
1704         p = strchr(action, '+');
1705         if (p)
1706                 *p = '\0';
1707
1708         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1709                 task->tk_pid, task->tk_flags, task->tk_status,
1710                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1711                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1712                 action, rpc_waitq);
1713 }
1714
1715 void rpc_show_tasks(void)
1716 {
1717         struct rpc_clnt *clnt;
1718         struct rpc_task *task;
1719         int header = 0;
1720
1721         spin_lock(&rpc_client_lock);
1722         list_for_each_entry(clnt, &all_clients, cl_clients) {
1723                 spin_lock(&clnt->cl_lock);
1724                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1725                         if (!header) {
1726                                 rpc_show_header();
1727                                 header++;
1728                         }
1729                         rpc_show_task(clnt, task);
1730                 }
1731                 spin_unlock(&clnt->cl_lock);
1732         }
1733         spin_unlock(&rpc_client_lock);
1734 }
1735 #endif