Merge branch 'for-2.6.32' of git://linux-nfs.org/~bfields/linux
[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/namei.h>
31 #include <linux/mount.h>
32 #include <linux/slab.h>
33 #include <linux/utsname.h>
34 #include <linux/workqueue.h>
35 #include <linux/in6.h>
36
37 #include <linux/sunrpc/clnt.h>
38 #include <linux/sunrpc/rpc_pipe_fs.h>
39 #include <linux/sunrpc/metrics.h>
40 #include <linux/sunrpc/bc_xprt.h>
41
42 #include "sunrpc.h"
43
44 #ifdef RPC_DEBUG
45 # define RPCDBG_FACILITY        RPCDBG_CALL
46 #endif
47
48 #define dprint_status(t)                                        \
49         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
50                         __func__, t->tk_status)
51
52 /*
53  * All RPC clients are linked into this list
54  */
55 static LIST_HEAD(all_clients);
56 static DEFINE_SPINLOCK(rpc_client_lock);
57
58 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
59
60
61 static void     call_start(struct rpc_task *task);
62 static void     call_reserve(struct rpc_task *task);
63 static void     call_reserveresult(struct rpc_task *task);
64 static void     call_allocate(struct rpc_task *task);
65 static void     call_decode(struct rpc_task *task);
66 static void     call_bind(struct rpc_task *task);
67 static void     call_bind_status(struct rpc_task *task);
68 static void     call_transmit(struct rpc_task *task);
69 #if defined(CONFIG_NFS_V4_1)
70 static void     call_bc_transmit(struct rpc_task *task);
71 #endif /* CONFIG_NFS_V4_1 */
72 static void     call_status(struct rpc_task *task);
73 static void     call_transmit_status(struct rpc_task *task);
74 static void     call_refresh(struct rpc_task *task);
75 static void     call_refreshresult(struct rpc_task *task);
76 static void     call_timeout(struct rpc_task *task);
77 static void     call_connect(struct rpc_task *task);
78 static void     call_connect_status(struct rpc_task *task);
79
80 static __be32   *rpc_encode_header(struct rpc_task *task);
81 static __be32   *rpc_verify_header(struct rpc_task *task);
82 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
83
84 static void rpc_register_client(struct rpc_clnt *clnt)
85 {
86         spin_lock(&rpc_client_lock);
87         list_add(&clnt->cl_clients, &all_clients);
88         spin_unlock(&rpc_client_lock);
89 }
90
91 static void rpc_unregister_client(struct rpc_clnt *clnt)
92 {
93         spin_lock(&rpc_client_lock);
94         list_del(&clnt->cl_clients);
95         spin_unlock(&rpc_client_lock);
96 }
97
98 static int
99 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
100 {
101         static uint32_t clntid;
102         struct nameidata nd;
103         struct path path;
104         char name[15];
105         struct qstr q = {
106                 .name = name,
107         };
108         int error;
109
110         clnt->cl_path.mnt = ERR_PTR(-ENOENT);
111         clnt->cl_path.dentry = ERR_PTR(-ENOENT);
112         if (dir_name == NULL)
113                 return 0;
114
115         path.mnt = rpc_get_mount();
116         if (IS_ERR(path.mnt))
117                 return PTR_ERR(path.mnt);
118         error = vfs_path_lookup(path.mnt->mnt_root, path.mnt, dir_name, 0, &nd);
119         if (error)
120                 goto err;
121
122         for (;;) {
123                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
124                 name[sizeof(name) - 1] = '\0';
125                 q.hash = full_name_hash(q.name, q.len);
126                 path.dentry = rpc_create_client_dir(nd.path.dentry, &q, clnt);
127                 if (!IS_ERR(path.dentry))
128                         break;
129                 error = PTR_ERR(path.dentry);
130                 if (error != -EEXIST) {
131                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
132                                         " %s/%s, error %d\n",
133                                         dir_name, name, error);
134                         goto err_path_put;
135                 }
136         }
137         path_put(&nd.path);
138         clnt->cl_path = path;
139         return 0;
140 err_path_put:
141         path_put(&nd.path);
142 err:
143         rpc_put_mount();
144         return error;
145 }
146
147 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
148 {
149         struct rpc_program      *program = args->program;
150         struct rpc_version      *version;
151         struct rpc_clnt         *clnt = NULL;
152         struct rpc_auth         *auth;
153         int err;
154         size_t len;
155
156         /* sanity check the name before trying to print it */
157         err = -EINVAL;
158         len = strlen(args->servername);
159         if (len > RPC_MAXNETNAMELEN)
160                 goto out_no_rpciod;
161         len++;
162
163         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
164                         program->name, args->servername, xprt);
165
166         err = rpciod_up();
167         if (err)
168                 goto out_no_rpciod;
169         err = -EINVAL;
170         if (!xprt)
171                 goto out_no_xprt;
172
173         if (args->version >= program->nrvers)
174                 goto out_err;
175         version = program->version[args->version];
176         if (version == NULL)
177                 goto out_err;
178
179         err = -ENOMEM;
180         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
181         if (!clnt)
182                 goto out_err;
183         clnt->cl_parent = clnt;
184
185         clnt->cl_server = clnt->cl_inline_name;
186         if (len > sizeof(clnt->cl_inline_name)) {
187                 char *buf = kmalloc(len, GFP_KERNEL);
188                 if (buf != NULL)
189                         clnt->cl_server = buf;
190                 else
191                         len = sizeof(clnt->cl_inline_name);
192         }
193         strlcpy(clnt->cl_server, args->servername, len);
194
195         clnt->cl_xprt     = xprt;
196         clnt->cl_procinfo = version->procs;
197         clnt->cl_maxproc  = version->nrprocs;
198         clnt->cl_protname = program->name;
199         clnt->cl_prog     = args->prognumber ? : program->number;
200         clnt->cl_vers     = version->number;
201         clnt->cl_stats    = program->stats;
202         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
203         err = -ENOMEM;
204         if (clnt->cl_metrics == NULL)
205                 goto out_no_stats;
206         clnt->cl_program  = program;
207         INIT_LIST_HEAD(&clnt->cl_tasks);
208         spin_lock_init(&clnt->cl_lock);
209
210         if (!xprt_bound(clnt->cl_xprt))
211                 clnt->cl_autobind = 1;
212
213         clnt->cl_timeout = xprt->timeout;
214         if (args->timeout != NULL) {
215                 memcpy(&clnt->cl_timeout_default, args->timeout,
216                                 sizeof(clnt->cl_timeout_default));
217                 clnt->cl_timeout = &clnt->cl_timeout_default;
218         }
219
220         clnt->cl_rtt = &clnt->cl_rtt_default;
221         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
222         clnt->cl_principal = NULL;
223         if (args->client_name) {
224                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
225                 if (!clnt->cl_principal)
226                         goto out_no_principal;
227         }
228
229         kref_init(&clnt->cl_kref);
230
231         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
232         if (err < 0)
233                 goto out_no_path;
234
235         auth = rpcauth_create(args->authflavor, clnt);
236         if (IS_ERR(auth)) {
237                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
238                                 args->authflavor);
239                 err = PTR_ERR(auth);
240                 goto out_no_auth;
241         }
242
243         /* save the nodename */
244         clnt->cl_nodelen = strlen(init_utsname()->nodename);
245         if (clnt->cl_nodelen > UNX_MAXNODENAME)
246                 clnt->cl_nodelen = UNX_MAXNODENAME;
247         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
248         rpc_register_client(clnt);
249         return clnt;
250
251 out_no_auth:
252         if (!IS_ERR(clnt->cl_path.dentry)) {
253                 rpc_remove_client_dir(clnt->cl_path.dentry);
254                 rpc_put_mount();
255         }
256 out_no_path:
257         kfree(clnt->cl_principal);
258 out_no_principal:
259         rpc_free_iostats(clnt->cl_metrics);
260 out_no_stats:
261         if (clnt->cl_server != clnt->cl_inline_name)
262                 kfree(clnt->cl_server);
263         kfree(clnt);
264 out_err:
265         xprt_put(xprt);
266 out_no_xprt:
267         rpciod_down();
268 out_no_rpciod:
269         return ERR_PTR(err);
270 }
271
272 /*
273  * rpc_create - create an RPC client and transport with one call
274  * @args: rpc_clnt create argument structure
275  *
276  * Creates and initializes an RPC transport and an RPC client.
277  *
278  * It can ping the server in order to determine if it is up, and to see if
279  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
280  * this behavior so asynchronous tasks can also use rpc_create.
281  */
282 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
283 {
284         struct rpc_xprt *xprt;
285         struct rpc_clnt *clnt;
286         struct xprt_create xprtargs = {
287                 .ident = args->protocol,
288                 .srcaddr = args->saddress,
289                 .dstaddr = args->address,
290                 .addrlen = args->addrsize,
291                 .bc_xprt = args->bc_xprt,
292         };
293         char servername[48];
294
295         /*
296          * If the caller chooses not to specify a hostname, whip
297          * up a string representation of the passed-in address.
298          */
299         if (args->servername == NULL) {
300                 servername[0] = '\0';
301                 switch (args->address->sa_family) {
302                 case AF_INET: {
303                         struct sockaddr_in *sin =
304                                         (struct sockaddr_in *)args->address;
305                         snprintf(servername, sizeof(servername), "%pI4",
306                                  &sin->sin_addr.s_addr);
307                         break;
308                 }
309                 case AF_INET6: {
310                         struct sockaddr_in6 *sin =
311                                         (struct sockaddr_in6 *)args->address;
312                         snprintf(servername, sizeof(servername), "%pI6",
313                                  &sin->sin6_addr);
314                         break;
315                 }
316                 default:
317                         /* caller wants default server name, but
318                          * address family isn't recognized. */
319                         return ERR_PTR(-EINVAL);
320                 }
321                 args->servername = servername;
322         }
323
324         xprt = xprt_create_transport(&xprtargs);
325         if (IS_ERR(xprt))
326                 return (struct rpc_clnt *)xprt;
327
328         /*
329          * By default, kernel RPC client connects from a reserved port.
330          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
331          * but it is always enabled for rpciod, which handles the connect
332          * operation.
333          */
334         xprt->resvport = 1;
335         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
336                 xprt->resvport = 0;
337
338         clnt = rpc_new_client(args, xprt);
339         if (IS_ERR(clnt))
340                 return clnt;
341
342         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
343                 int err = rpc_ping(clnt, RPC_TASK_SOFT);
344                 if (err != 0) {
345                         rpc_shutdown_client(clnt);
346                         return ERR_PTR(err);
347                 }
348         }
349
350         clnt->cl_softrtry = 1;
351         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
352                 clnt->cl_softrtry = 0;
353
354         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
355                 clnt->cl_autobind = 1;
356         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
357                 clnt->cl_discrtry = 1;
358         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
359                 clnt->cl_chatty = 1;
360
361         return clnt;
362 }
363 EXPORT_SYMBOL_GPL(rpc_create);
364
365 /*
366  * This function clones the RPC client structure. It allows us to share the
367  * same transport while varying parameters such as the authentication
368  * flavour.
369  */
370 struct rpc_clnt *
371 rpc_clone_client(struct rpc_clnt *clnt)
372 {
373         struct rpc_clnt *new;
374         int err = -ENOMEM;
375
376         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
377         if (!new)
378                 goto out_no_clnt;
379         new->cl_parent = clnt;
380         /* Turn off autobind on clones */
381         new->cl_autobind = 0;
382         INIT_LIST_HEAD(&new->cl_tasks);
383         spin_lock_init(&new->cl_lock);
384         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
385         new->cl_metrics = rpc_alloc_iostats(clnt);
386         if (new->cl_metrics == NULL)
387                 goto out_no_stats;
388         if (clnt->cl_principal) {
389                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
390                 if (new->cl_principal == NULL)
391                         goto out_no_principal;
392         }
393         kref_init(&new->cl_kref);
394         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
395         if (err != 0)
396                 goto out_no_path;
397         if (new->cl_auth)
398                 atomic_inc(&new->cl_auth->au_count);
399         xprt_get(clnt->cl_xprt);
400         kref_get(&clnt->cl_kref);
401         rpc_register_client(new);
402         rpciod_up();
403         return new;
404 out_no_path:
405         kfree(new->cl_principal);
406 out_no_principal:
407         rpc_free_iostats(new->cl_metrics);
408 out_no_stats:
409         kfree(new);
410 out_no_clnt:
411         dprintk("RPC:       %s: returned error %d\n", __func__, err);
412         return ERR_PTR(err);
413 }
414 EXPORT_SYMBOL_GPL(rpc_clone_client);
415
416 /*
417  * Properly shut down an RPC client, terminating all outstanding
418  * requests.
419  */
420 void rpc_shutdown_client(struct rpc_clnt *clnt)
421 {
422         dprintk("RPC:       shutting down %s client for %s\n",
423                         clnt->cl_protname, clnt->cl_server);
424
425         while (!list_empty(&clnt->cl_tasks)) {
426                 rpc_killall_tasks(clnt);
427                 wait_event_timeout(destroy_wait,
428                         list_empty(&clnt->cl_tasks), 1*HZ);
429         }
430
431         rpc_release_client(clnt);
432 }
433 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
434
435 /*
436  * Free an RPC client
437  */
438 static void
439 rpc_free_client(struct kref *kref)
440 {
441         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
442
443         dprintk("RPC:       destroying %s client for %s\n",
444                         clnt->cl_protname, clnt->cl_server);
445         if (!IS_ERR(clnt->cl_path.dentry)) {
446                 rpc_remove_client_dir(clnt->cl_path.dentry);
447                 rpc_put_mount();
448         }
449         if (clnt->cl_parent != clnt) {
450                 rpc_release_client(clnt->cl_parent);
451                 goto out_free;
452         }
453         if (clnt->cl_server != clnt->cl_inline_name)
454                 kfree(clnt->cl_server);
455 out_free:
456         rpc_unregister_client(clnt);
457         rpc_free_iostats(clnt->cl_metrics);
458         kfree(clnt->cl_principal);
459         clnt->cl_metrics = NULL;
460         xprt_put(clnt->cl_xprt);
461         rpciod_down();
462         kfree(clnt);
463 }
464
465 /*
466  * Free an RPC client
467  */
468 static void
469 rpc_free_auth(struct kref *kref)
470 {
471         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
472
473         if (clnt->cl_auth == NULL) {
474                 rpc_free_client(kref);
475                 return;
476         }
477
478         /*
479          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
480          *       release remaining GSS contexts. This mechanism ensures
481          *       that it can do so safely.
482          */
483         kref_init(kref);
484         rpcauth_release(clnt->cl_auth);
485         clnt->cl_auth = NULL;
486         kref_put(kref, rpc_free_client);
487 }
488
489 /*
490  * Release reference to the RPC client
491  */
492 void
493 rpc_release_client(struct rpc_clnt *clnt)
494 {
495         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
496
497         if (list_empty(&clnt->cl_tasks))
498                 wake_up(&destroy_wait);
499         kref_put(&clnt->cl_kref, rpc_free_auth);
500 }
501
502 /**
503  * rpc_bind_new_program - bind a new RPC program to an existing client
504  * @old: old rpc_client
505  * @program: rpc program to set
506  * @vers: rpc program version
507  *
508  * Clones the rpc client and sets up a new RPC program. This is mainly
509  * of use for enabling different RPC programs to share the same transport.
510  * The Sun NFSv2/v3 ACL protocol can do this.
511  */
512 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
513                                       struct rpc_program *program,
514                                       u32 vers)
515 {
516         struct rpc_clnt *clnt;
517         struct rpc_version *version;
518         int err;
519
520         BUG_ON(vers >= program->nrvers || !program->version[vers]);
521         version = program->version[vers];
522         clnt = rpc_clone_client(old);
523         if (IS_ERR(clnt))
524                 goto out;
525         clnt->cl_procinfo = version->procs;
526         clnt->cl_maxproc  = version->nrprocs;
527         clnt->cl_protname = program->name;
528         clnt->cl_prog     = program->number;
529         clnt->cl_vers     = version->number;
530         clnt->cl_stats    = program->stats;
531         err = rpc_ping(clnt, RPC_TASK_SOFT);
532         if (err != 0) {
533                 rpc_shutdown_client(clnt);
534                 clnt = ERR_PTR(err);
535         }
536 out:
537         return clnt;
538 }
539 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
540
541 /*
542  * Default callback for async RPC calls
543  */
544 static void
545 rpc_default_callback(struct rpc_task *task, void *data)
546 {
547 }
548
549 static const struct rpc_call_ops rpc_default_ops = {
550         .rpc_call_done = rpc_default_callback,
551 };
552
553 /**
554  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
555  * @task_setup_data: pointer to task initialisation data
556  */
557 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
558 {
559         struct rpc_task *task, *ret;
560
561         task = rpc_new_task(task_setup_data);
562         if (task == NULL) {
563                 rpc_release_calldata(task_setup_data->callback_ops,
564                                 task_setup_data->callback_data);
565                 ret = ERR_PTR(-ENOMEM);
566                 goto out;
567         }
568
569         if (task->tk_status != 0) {
570                 ret = ERR_PTR(task->tk_status);
571                 rpc_put_task(task);
572                 goto out;
573         }
574         atomic_inc(&task->tk_count);
575         rpc_execute(task);
576         ret = task;
577 out:
578         return ret;
579 }
580 EXPORT_SYMBOL_GPL(rpc_run_task);
581
582 /**
583  * rpc_call_sync - Perform a synchronous RPC call
584  * @clnt: pointer to RPC client
585  * @msg: RPC call parameters
586  * @flags: RPC call flags
587  */
588 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
589 {
590         struct rpc_task *task;
591         struct rpc_task_setup task_setup_data = {
592                 .rpc_client = clnt,
593                 .rpc_message = msg,
594                 .callback_ops = &rpc_default_ops,
595                 .flags = flags,
596         };
597         int status;
598
599         BUG_ON(flags & RPC_TASK_ASYNC);
600
601         task = rpc_run_task(&task_setup_data);
602         if (IS_ERR(task))
603                 return PTR_ERR(task);
604         status = task->tk_status;
605         rpc_put_task(task);
606         return status;
607 }
608 EXPORT_SYMBOL_GPL(rpc_call_sync);
609
610 /**
611  * rpc_call_async - Perform an asynchronous RPC call
612  * @clnt: pointer to RPC client
613  * @msg: RPC call parameters
614  * @flags: RPC call flags
615  * @tk_ops: RPC call ops
616  * @data: user call data
617  */
618 int
619 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
620                const struct rpc_call_ops *tk_ops, void *data)
621 {
622         struct rpc_task *task;
623         struct rpc_task_setup task_setup_data = {
624                 .rpc_client = clnt,
625                 .rpc_message = msg,
626                 .callback_ops = tk_ops,
627                 .callback_data = data,
628                 .flags = flags|RPC_TASK_ASYNC,
629         };
630
631         task = rpc_run_task(&task_setup_data);
632         if (IS_ERR(task))
633                 return PTR_ERR(task);
634         rpc_put_task(task);
635         return 0;
636 }
637 EXPORT_SYMBOL_GPL(rpc_call_async);
638
639 #if defined(CONFIG_NFS_V4_1)
640 /**
641  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
642  * rpc_execute against it
643  * @ops: RPC call ops
644  */
645 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
646                                         const struct rpc_call_ops *tk_ops)
647 {
648         struct rpc_task *task;
649         struct xdr_buf *xbufp = &req->rq_snd_buf;
650         struct rpc_task_setup task_setup_data = {
651                 .callback_ops = tk_ops,
652         };
653
654         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
655         /*
656          * Create an rpc_task to send the data
657          */
658         task = rpc_new_task(&task_setup_data);
659         if (!task) {
660                 xprt_free_bc_request(req);
661                 goto out;
662         }
663         task->tk_rqstp = req;
664
665         /*
666          * Set up the xdr_buf length.
667          * This also indicates that the buffer is XDR encoded already.
668          */
669         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
670                         xbufp->tail[0].iov_len;
671
672         task->tk_action = call_bc_transmit;
673         atomic_inc(&task->tk_count);
674         BUG_ON(atomic_read(&task->tk_count) != 2);
675         rpc_execute(task);
676
677 out:
678         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
679         return task;
680 }
681 #endif /* CONFIG_NFS_V4_1 */
682
683 void
684 rpc_call_start(struct rpc_task *task)
685 {
686         task->tk_action = call_start;
687 }
688 EXPORT_SYMBOL_GPL(rpc_call_start);
689
690 /**
691  * rpc_peeraddr - extract remote peer address from clnt's xprt
692  * @clnt: RPC client structure
693  * @buf: target buffer
694  * @bufsize: length of target buffer
695  *
696  * Returns the number of bytes that are actually in the stored address.
697  */
698 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
699 {
700         size_t bytes;
701         struct rpc_xprt *xprt = clnt->cl_xprt;
702
703         bytes = sizeof(xprt->addr);
704         if (bytes > bufsize)
705                 bytes = bufsize;
706         memcpy(buf, &clnt->cl_xprt->addr, bytes);
707         return xprt->addrlen;
708 }
709 EXPORT_SYMBOL_GPL(rpc_peeraddr);
710
711 /**
712  * rpc_peeraddr2str - return remote peer address in printable format
713  * @clnt: RPC client structure
714  * @format: address format
715  *
716  */
717 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
718                              enum rpc_display_format_t format)
719 {
720         struct rpc_xprt *xprt = clnt->cl_xprt;
721
722         if (xprt->address_strings[format] != NULL)
723                 return xprt->address_strings[format];
724         else
725                 return "unprintable";
726 }
727 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
728
729 void
730 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
731 {
732         struct rpc_xprt *xprt = clnt->cl_xprt;
733         if (xprt->ops->set_buffer_size)
734                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
735 }
736 EXPORT_SYMBOL_GPL(rpc_setbufsize);
737
738 /*
739  * Return size of largest payload RPC client can support, in bytes
740  *
741  * For stream transports, this is one RPC record fragment (see RFC
742  * 1831), as we don't support multi-record requests yet.  For datagram
743  * transports, this is the size of an IP packet minus the IP, UDP, and
744  * RPC header sizes.
745  */
746 size_t rpc_max_payload(struct rpc_clnt *clnt)
747 {
748         return clnt->cl_xprt->max_payload;
749 }
750 EXPORT_SYMBOL_GPL(rpc_max_payload);
751
752 /**
753  * rpc_force_rebind - force transport to check that remote port is unchanged
754  * @clnt: client to rebind
755  *
756  */
757 void rpc_force_rebind(struct rpc_clnt *clnt)
758 {
759         if (clnt->cl_autobind)
760                 xprt_clear_bound(clnt->cl_xprt);
761 }
762 EXPORT_SYMBOL_GPL(rpc_force_rebind);
763
764 /*
765  * Restart an (async) RPC call from the call_prepare state.
766  * Usually called from within the exit handler.
767  */
768 void
769 rpc_restart_call_prepare(struct rpc_task *task)
770 {
771         if (RPC_ASSASSINATED(task))
772                 return;
773         task->tk_action = rpc_prepare_task;
774 }
775 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
776
777 /*
778  * Restart an (async) RPC call. Usually called from within the
779  * exit handler.
780  */
781 void
782 rpc_restart_call(struct rpc_task *task)
783 {
784         if (RPC_ASSASSINATED(task))
785                 return;
786
787         task->tk_action = call_start;
788 }
789 EXPORT_SYMBOL_GPL(rpc_restart_call);
790
791 #ifdef RPC_DEBUG
792 static const char *rpc_proc_name(const struct rpc_task *task)
793 {
794         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
795
796         if (proc) {
797                 if (proc->p_name)
798                         return proc->p_name;
799                 else
800                         return "NULL";
801         } else
802                 return "no proc";
803 }
804 #endif
805
806 /*
807  * 0.  Initial state
808  *
809  *     Other FSM states can be visited zero or more times, but
810  *     this state is visited exactly once for each RPC.
811  */
812 static void
813 call_start(struct rpc_task *task)
814 {
815         struct rpc_clnt *clnt = task->tk_client;
816
817         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
818                         clnt->cl_protname, clnt->cl_vers,
819                         rpc_proc_name(task),
820                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
821
822         /* Increment call count */
823         task->tk_msg.rpc_proc->p_count++;
824         clnt->cl_stats->rpccnt++;
825         task->tk_action = call_reserve;
826 }
827
828 /*
829  * 1.   Reserve an RPC call slot
830  */
831 static void
832 call_reserve(struct rpc_task *task)
833 {
834         dprint_status(task);
835
836         if (!rpcauth_uptodatecred(task)) {
837                 task->tk_action = call_refresh;
838                 return;
839         }
840
841         task->tk_status  = 0;
842         task->tk_action  = call_reserveresult;
843         xprt_reserve(task);
844 }
845
846 /*
847  * 1b.  Grok the result of xprt_reserve()
848  */
849 static void
850 call_reserveresult(struct rpc_task *task)
851 {
852         int status = task->tk_status;
853
854         dprint_status(task);
855
856         /*
857          * After a call to xprt_reserve(), we must have either
858          * a request slot or else an error status.
859          */
860         task->tk_status = 0;
861         if (status >= 0) {
862                 if (task->tk_rqstp) {
863                         task->tk_action = call_allocate;
864                         return;
865                 }
866
867                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
868                                 __func__, status);
869                 rpc_exit(task, -EIO);
870                 return;
871         }
872
873         /*
874          * Even though there was an error, we may have acquired
875          * a request slot somehow.  Make sure not to leak it.
876          */
877         if (task->tk_rqstp) {
878                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
879                                 __func__, status);
880                 xprt_release(task);
881         }
882
883         switch (status) {
884         case -EAGAIN:   /* woken up; retry */
885                 task->tk_action = call_reserve;
886                 return;
887         case -EIO:      /* probably a shutdown */
888                 break;
889         default:
890                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
891                                 __func__, status);
892                 break;
893         }
894         rpc_exit(task, status);
895 }
896
897 /*
898  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
899  *      (Note: buffer memory is freed in xprt_release).
900  */
901 static void
902 call_allocate(struct rpc_task *task)
903 {
904         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
905         struct rpc_rqst *req = task->tk_rqstp;
906         struct rpc_xprt *xprt = task->tk_xprt;
907         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
908
909         dprint_status(task);
910
911         task->tk_status = 0;
912         task->tk_action = call_bind;
913
914         if (req->rq_buffer)
915                 return;
916
917         if (proc->p_proc != 0) {
918                 BUG_ON(proc->p_arglen == 0);
919                 if (proc->p_decode != NULL)
920                         BUG_ON(proc->p_replen == 0);
921         }
922
923         /*
924          * Calculate the size (in quads) of the RPC call
925          * and reply headers, and convert both values
926          * to byte sizes.
927          */
928         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
929         req->rq_callsize <<= 2;
930         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
931         req->rq_rcvsize <<= 2;
932
933         req->rq_buffer = xprt->ops->buf_alloc(task,
934                                         req->rq_callsize + req->rq_rcvsize);
935         if (req->rq_buffer != NULL)
936                 return;
937
938         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
939
940         if (RPC_IS_ASYNC(task) || !signalled()) {
941                 task->tk_action = call_allocate;
942                 rpc_delay(task, HZ>>4);
943                 return;
944         }
945
946         rpc_exit(task, -ERESTARTSYS);
947 }
948
949 static inline int
950 rpc_task_need_encode(struct rpc_task *task)
951 {
952         return task->tk_rqstp->rq_snd_buf.len == 0;
953 }
954
955 static inline void
956 rpc_task_force_reencode(struct rpc_task *task)
957 {
958         task->tk_rqstp->rq_snd_buf.len = 0;
959         task->tk_rqstp->rq_bytes_sent = 0;
960 }
961
962 static inline void
963 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
964 {
965         buf->head[0].iov_base = start;
966         buf->head[0].iov_len = len;
967         buf->tail[0].iov_len = 0;
968         buf->page_len = 0;
969         buf->flags = 0;
970         buf->len = 0;
971         buf->buflen = len;
972 }
973
974 /*
975  * 3.   Encode arguments of an RPC call
976  */
977 static void
978 rpc_xdr_encode(struct rpc_task *task)
979 {
980         struct rpc_rqst *req = task->tk_rqstp;
981         kxdrproc_t      encode;
982         __be32          *p;
983
984         dprint_status(task);
985
986         rpc_xdr_buf_init(&req->rq_snd_buf,
987                          req->rq_buffer,
988                          req->rq_callsize);
989         rpc_xdr_buf_init(&req->rq_rcv_buf,
990                          (char *)req->rq_buffer + req->rq_callsize,
991                          req->rq_rcvsize);
992
993         p = rpc_encode_header(task);
994         if (p == NULL) {
995                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
996                 rpc_exit(task, -EIO);
997                 return;
998         }
999
1000         encode = task->tk_msg.rpc_proc->p_encode;
1001         if (encode == NULL)
1002                 return;
1003
1004         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1005                         task->tk_msg.rpc_argp);
1006 }
1007
1008 /*
1009  * 4.   Get the server port number if not yet set
1010  */
1011 static void
1012 call_bind(struct rpc_task *task)
1013 {
1014         struct rpc_xprt *xprt = task->tk_xprt;
1015
1016         dprint_status(task);
1017
1018         task->tk_action = call_connect;
1019         if (!xprt_bound(xprt)) {
1020                 task->tk_action = call_bind_status;
1021                 task->tk_timeout = xprt->bind_timeout;
1022                 xprt->ops->rpcbind(task);
1023         }
1024 }
1025
1026 /*
1027  * 4a.  Sort out bind result
1028  */
1029 static void
1030 call_bind_status(struct rpc_task *task)
1031 {
1032         int status = -EIO;
1033
1034         if (task->tk_status >= 0) {
1035                 dprint_status(task);
1036                 task->tk_status = 0;
1037                 task->tk_action = call_connect;
1038                 return;
1039         }
1040
1041         switch (task->tk_status) {
1042         case -ENOMEM:
1043                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1044                 rpc_delay(task, HZ >> 2);
1045                 goto retry_timeout;
1046         case -EACCES:
1047                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1048                                 "unavailable\n", task->tk_pid);
1049                 /* fail immediately if this is an RPC ping */
1050                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1051                         status = -EOPNOTSUPP;
1052                         break;
1053                 }
1054                 rpc_delay(task, 3*HZ);
1055                 goto retry_timeout;
1056         case -ETIMEDOUT:
1057                 dprintk("RPC: %5u rpcbind request timed out\n",
1058                                 task->tk_pid);
1059                 goto retry_timeout;
1060         case -EPFNOSUPPORT:
1061                 /* server doesn't support any rpcbind version we know of */
1062                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
1063                                 task->tk_pid);
1064                 break;
1065         case -EPROTONOSUPPORT:
1066                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1067                                 task->tk_pid);
1068                 task->tk_status = 0;
1069                 task->tk_action = call_bind;
1070                 return;
1071         default:
1072                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1073                                 task->tk_pid, -task->tk_status);
1074         }
1075
1076         rpc_exit(task, status);
1077         return;
1078
1079 retry_timeout:
1080         task->tk_action = call_timeout;
1081 }
1082
1083 /*
1084  * 4b.  Connect to the RPC server
1085  */
1086 static void
1087 call_connect(struct rpc_task *task)
1088 {
1089         struct rpc_xprt *xprt = task->tk_xprt;
1090
1091         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1092                         task->tk_pid, xprt,
1093                         (xprt_connected(xprt) ? "is" : "is not"));
1094
1095         task->tk_action = call_transmit;
1096         if (!xprt_connected(xprt)) {
1097                 task->tk_action = call_connect_status;
1098                 if (task->tk_status < 0)
1099                         return;
1100                 xprt_connect(task);
1101         }
1102 }
1103
1104 /*
1105  * 4c.  Sort out connect result
1106  */
1107 static void
1108 call_connect_status(struct rpc_task *task)
1109 {
1110         struct rpc_clnt *clnt = task->tk_client;
1111         int status = task->tk_status;
1112
1113         dprint_status(task);
1114
1115         task->tk_status = 0;
1116         if (status >= 0 || status == -EAGAIN) {
1117                 clnt->cl_stats->netreconn++;
1118                 task->tk_action = call_transmit;
1119                 return;
1120         }
1121
1122         switch (status) {
1123                 /* if soft mounted, test if we've timed out */
1124         case -ETIMEDOUT:
1125                 task->tk_action = call_timeout;
1126                 break;
1127         default:
1128                 rpc_exit(task, -EIO);
1129         }
1130 }
1131
1132 /*
1133  * 5.   Transmit the RPC request, and wait for reply
1134  */
1135 static void
1136 call_transmit(struct rpc_task *task)
1137 {
1138         dprint_status(task);
1139
1140         task->tk_action = call_status;
1141         if (task->tk_status < 0)
1142                 return;
1143         task->tk_status = xprt_prepare_transmit(task);
1144         if (task->tk_status != 0)
1145                 return;
1146         task->tk_action = call_transmit_status;
1147         /* Encode here so that rpcsec_gss can use correct sequence number. */
1148         if (rpc_task_need_encode(task)) {
1149                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1150                 rpc_xdr_encode(task);
1151                 /* Did the encode result in an error condition? */
1152                 if (task->tk_status != 0) {
1153                         /* Was the error nonfatal? */
1154                         if (task->tk_status == -EAGAIN)
1155                                 rpc_delay(task, HZ >> 4);
1156                         else
1157                                 rpc_exit(task, task->tk_status);
1158                         return;
1159                 }
1160         }
1161         xprt_transmit(task);
1162         if (task->tk_status < 0)
1163                 return;
1164         /*
1165          * On success, ensure that we call xprt_end_transmit() before sleeping
1166          * in order to allow access to the socket to other RPC requests.
1167          */
1168         call_transmit_status(task);
1169         if (rpc_reply_expected(task))
1170                 return;
1171         task->tk_action = rpc_exit_task;
1172         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1173 }
1174
1175 /*
1176  * 5a.  Handle cleanup after a transmission
1177  */
1178 static void
1179 call_transmit_status(struct rpc_task *task)
1180 {
1181         task->tk_action = call_status;
1182         switch (task->tk_status) {
1183         case -EAGAIN:
1184                 break;
1185         default:
1186                 xprt_end_transmit(task);
1187                 /*
1188                  * Special cases: if we've been waiting on the
1189                  * socket's write_space() callback, or if the
1190                  * socket just returned a connection error,
1191                  * then hold onto the transport lock.
1192                  */
1193         case -ECONNREFUSED:
1194         case -ECONNRESET:
1195         case -ENOTCONN:
1196         case -EHOSTDOWN:
1197         case -EHOSTUNREACH:
1198         case -ENETUNREACH:
1199         case -EPIPE:
1200                 rpc_task_force_reencode(task);
1201         }
1202 }
1203
1204 #if defined(CONFIG_NFS_V4_1)
1205 /*
1206  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1207  * addition, disconnect on connectivity errors.
1208  */
1209 static void
1210 call_bc_transmit(struct rpc_task *task)
1211 {
1212         struct rpc_rqst *req = task->tk_rqstp;
1213
1214         BUG_ON(task->tk_status != 0);
1215         task->tk_status = xprt_prepare_transmit(task);
1216         if (task->tk_status == -EAGAIN) {
1217                 /*
1218                  * Could not reserve the transport. Try again after the
1219                  * transport is released.
1220                  */
1221                 task->tk_status = 0;
1222                 task->tk_action = call_bc_transmit;
1223                 return;
1224         }
1225
1226         task->tk_action = rpc_exit_task;
1227         if (task->tk_status < 0) {
1228                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1229                         "error: %d\n", task->tk_status);
1230                 return;
1231         }
1232
1233         xprt_transmit(task);
1234         xprt_end_transmit(task);
1235         dprint_status(task);
1236         switch (task->tk_status) {
1237         case 0:
1238                 /* Success */
1239                 break;
1240         case -EHOSTDOWN:
1241         case -EHOSTUNREACH:
1242         case -ENETUNREACH:
1243         case -ETIMEDOUT:
1244                 /*
1245                  * Problem reaching the server.  Disconnect and let the
1246                  * forechannel reestablish the connection.  The server will
1247                  * have to retransmit the backchannel request and we'll
1248                  * reprocess it.  Since these ops are idempotent, there's no
1249                  * need to cache our reply at this time.
1250                  */
1251                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1252                         "error: %d\n", task->tk_status);
1253                 xprt_conditional_disconnect(task->tk_xprt,
1254                         req->rq_connect_cookie);
1255                 break;
1256         default:
1257                 /*
1258                  * We were unable to reply and will have to drop the
1259                  * request.  The server should reconnect and retransmit.
1260                  */
1261                 BUG_ON(task->tk_status == -EAGAIN);
1262                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1263                         "error: %d\n", task->tk_status);
1264                 break;
1265         }
1266         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1267 }
1268 #endif /* CONFIG_NFS_V4_1 */
1269
1270 /*
1271  * 6.   Sort out the RPC call status
1272  */
1273 static void
1274 call_status(struct rpc_task *task)
1275 {
1276         struct rpc_clnt *clnt = task->tk_client;
1277         struct rpc_rqst *req = task->tk_rqstp;
1278         int             status;
1279
1280         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1281                 task->tk_status = req->rq_reply_bytes_recvd;
1282
1283         dprint_status(task);
1284
1285         status = task->tk_status;
1286         if (status >= 0) {
1287                 task->tk_action = call_decode;
1288                 return;
1289         }
1290
1291         task->tk_status = 0;
1292         switch(status) {
1293         case -EHOSTDOWN:
1294         case -EHOSTUNREACH:
1295         case -ENETUNREACH:
1296                 /*
1297                  * Delay any retries for 3 seconds, then handle as if it
1298                  * were a timeout.
1299                  */
1300                 rpc_delay(task, 3*HZ);
1301         case -ETIMEDOUT:
1302                 task->tk_action = call_timeout;
1303                 if (task->tk_client->cl_discrtry)
1304                         xprt_conditional_disconnect(task->tk_xprt,
1305                                         req->rq_connect_cookie);
1306                 break;
1307         case -ECONNRESET:
1308         case -ECONNREFUSED:
1309                 rpc_force_rebind(clnt);
1310                 rpc_delay(task, 3*HZ);
1311         case -EPIPE:
1312         case -ENOTCONN:
1313                 task->tk_action = call_bind;
1314                 break;
1315         case -EAGAIN:
1316                 task->tk_action = call_transmit;
1317                 break;
1318         case -EIO:
1319                 /* shutdown or soft timeout */
1320                 rpc_exit(task, status);
1321                 break;
1322         default:
1323                 if (clnt->cl_chatty)
1324                         printk("%s: RPC call returned error %d\n",
1325                                clnt->cl_protname, -status);
1326                 rpc_exit(task, status);
1327         }
1328 }
1329
1330 /*
1331  * 6a.  Handle RPC timeout
1332  *      We do not release the request slot, so we keep using the
1333  *      same XID for all retransmits.
1334  */
1335 static void
1336 call_timeout(struct rpc_task *task)
1337 {
1338         struct rpc_clnt *clnt = task->tk_client;
1339
1340         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1341                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1342                 goto retry;
1343         }
1344
1345         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1346         task->tk_timeouts++;
1347
1348         if (RPC_IS_SOFT(task)) {
1349                 if (clnt->cl_chatty)
1350                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1351                                 clnt->cl_protname, clnt->cl_server);
1352                 rpc_exit(task, -EIO);
1353                 return;
1354         }
1355
1356         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1357                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1358                 if (clnt->cl_chatty)
1359                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1360                         clnt->cl_protname, clnt->cl_server);
1361         }
1362         rpc_force_rebind(clnt);
1363         /*
1364          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1365          * event? RFC2203 requires the server to drop all such requests.
1366          */
1367         rpcauth_invalcred(task);
1368
1369 retry:
1370         clnt->cl_stats->rpcretrans++;
1371         task->tk_action = call_bind;
1372         task->tk_status = 0;
1373 }
1374
1375 /*
1376  * 7.   Decode the RPC reply
1377  */
1378 static void
1379 call_decode(struct rpc_task *task)
1380 {
1381         struct rpc_clnt *clnt = task->tk_client;
1382         struct rpc_rqst *req = task->tk_rqstp;
1383         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1384         __be32          *p;
1385
1386         dprintk("RPC: %5u call_decode (status %d)\n",
1387                         task->tk_pid, task->tk_status);
1388
1389         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1390                 if (clnt->cl_chatty)
1391                         printk(KERN_NOTICE "%s: server %s OK\n",
1392                                 clnt->cl_protname, clnt->cl_server);
1393                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1394         }
1395
1396         /*
1397          * Ensure that we see all writes made by xprt_complete_rqst()
1398          * before it changed req->rq_reply_bytes_recvd.
1399          */
1400         smp_rmb();
1401         req->rq_rcv_buf.len = req->rq_private_buf.len;
1402
1403         /* Check that the softirq receive buffer is valid */
1404         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1405                                 sizeof(req->rq_rcv_buf)) != 0);
1406
1407         if (req->rq_rcv_buf.len < 12) {
1408                 if (!RPC_IS_SOFT(task)) {
1409                         task->tk_action = call_bind;
1410                         clnt->cl_stats->rpcretrans++;
1411                         goto out_retry;
1412                 }
1413                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1414                                 clnt->cl_protname, task->tk_status);
1415                 task->tk_action = call_timeout;
1416                 goto out_retry;
1417         }
1418
1419         p = rpc_verify_header(task);
1420         if (IS_ERR(p)) {
1421                 if (p == ERR_PTR(-EAGAIN))
1422                         goto out_retry;
1423                 return;
1424         }
1425
1426         task->tk_action = rpc_exit_task;
1427
1428         if (decode) {
1429                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1430                                                       task->tk_msg.rpc_resp);
1431         }
1432         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1433                         task->tk_status);
1434         return;
1435 out_retry:
1436         task->tk_status = 0;
1437         /* Note: rpc_verify_header() may have freed the RPC slot */
1438         if (task->tk_rqstp == req) {
1439                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1440                 if (task->tk_client->cl_discrtry)
1441                         xprt_conditional_disconnect(task->tk_xprt,
1442                                         req->rq_connect_cookie);
1443         }
1444 }
1445
1446 /*
1447  * 8.   Refresh the credentials if rejected by the server
1448  */
1449 static void
1450 call_refresh(struct rpc_task *task)
1451 {
1452         dprint_status(task);
1453
1454         task->tk_action = call_refreshresult;
1455         task->tk_status = 0;
1456         task->tk_client->cl_stats->rpcauthrefresh++;
1457         rpcauth_refreshcred(task);
1458 }
1459
1460 /*
1461  * 8a.  Process the results of a credential refresh
1462  */
1463 static void
1464 call_refreshresult(struct rpc_task *task)
1465 {
1466         int status = task->tk_status;
1467
1468         dprint_status(task);
1469
1470         task->tk_status = 0;
1471         task->tk_action = call_reserve;
1472         if (status >= 0 && rpcauth_uptodatecred(task))
1473                 return;
1474         if (status == -EACCES) {
1475                 rpc_exit(task, -EACCES);
1476                 return;
1477         }
1478         task->tk_action = call_refresh;
1479         if (status != -ETIMEDOUT)
1480                 rpc_delay(task, 3*HZ);
1481         return;
1482 }
1483
1484 static __be32 *
1485 rpc_encode_header(struct rpc_task *task)
1486 {
1487         struct rpc_clnt *clnt = task->tk_client;
1488         struct rpc_rqst *req = task->tk_rqstp;
1489         __be32          *p = req->rq_svec[0].iov_base;
1490
1491         /* FIXME: check buffer size? */
1492
1493         p = xprt_skip_transport_header(task->tk_xprt, p);
1494         *p++ = req->rq_xid;             /* XID */
1495         *p++ = htonl(RPC_CALL);         /* CALL */
1496         *p++ = htonl(RPC_VERSION);      /* RPC version */
1497         *p++ = htonl(clnt->cl_prog);    /* program number */
1498         *p++ = htonl(clnt->cl_vers);    /* program version */
1499         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1500         p = rpcauth_marshcred(task, p);
1501         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1502         return p;
1503 }
1504
1505 static __be32 *
1506 rpc_verify_header(struct rpc_task *task)
1507 {
1508         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1509         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1510         __be32  *p = iov->iov_base;
1511         u32 n;
1512         int error = -EACCES;
1513
1514         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1515                 /* RFC-1014 says that the representation of XDR data must be a
1516                  * multiple of four bytes
1517                  * - if it isn't pointer subtraction in the NFS client may give
1518                  *   undefined results
1519                  */
1520                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1521                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1522                        task->tk_rqstp->rq_rcv_buf.len);
1523                 goto out_eio;
1524         }
1525         if ((len -= 3) < 0)
1526                 goto out_overflow;
1527
1528         p += 1; /* skip XID */
1529         if ((n = ntohl(*p++)) != RPC_REPLY) {
1530                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1531                         task->tk_pid, __func__, n);
1532                 goto out_garbage;
1533         }
1534
1535         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1536                 if (--len < 0)
1537                         goto out_overflow;
1538                 switch ((n = ntohl(*p++))) {
1539                         case RPC_AUTH_ERROR:
1540                                 break;
1541                         case RPC_MISMATCH:
1542                                 dprintk("RPC: %5u %s: RPC call version "
1543                                                 "mismatch!\n",
1544                                                 task->tk_pid, __func__);
1545                                 error = -EPROTONOSUPPORT;
1546                                 goto out_err;
1547                         default:
1548                                 dprintk("RPC: %5u %s: RPC call rejected, "
1549                                                 "unknown error: %x\n",
1550                                                 task->tk_pid, __func__, n);
1551                                 goto out_eio;
1552                 }
1553                 if (--len < 0)
1554                         goto out_overflow;
1555                 switch ((n = ntohl(*p++))) {
1556                 case RPC_AUTH_REJECTEDCRED:
1557                 case RPC_AUTH_REJECTEDVERF:
1558                 case RPCSEC_GSS_CREDPROBLEM:
1559                 case RPCSEC_GSS_CTXPROBLEM:
1560                         if (!task->tk_cred_retry)
1561                                 break;
1562                         task->tk_cred_retry--;
1563                         dprintk("RPC: %5u %s: retry stale creds\n",
1564                                         task->tk_pid, __func__);
1565                         rpcauth_invalcred(task);
1566                         /* Ensure we obtain a new XID! */
1567                         xprt_release(task);
1568                         task->tk_action = call_refresh;
1569                         goto out_retry;
1570                 case RPC_AUTH_BADCRED:
1571                 case RPC_AUTH_BADVERF:
1572                         /* possibly garbled cred/verf? */
1573                         if (!task->tk_garb_retry)
1574                                 break;
1575                         task->tk_garb_retry--;
1576                         dprintk("RPC: %5u %s: retry garbled creds\n",
1577                                         task->tk_pid, __func__);
1578                         task->tk_action = call_bind;
1579                         goto out_retry;
1580                 case RPC_AUTH_TOOWEAK:
1581                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1582                                "authentication.\n", task->tk_client->cl_server);
1583                         break;
1584                 default:
1585                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1586                                         task->tk_pid, __func__, n);
1587                         error = -EIO;
1588                 }
1589                 dprintk("RPC: %5u %s: call rejected %d\n",
1590                                 task->tk_pid, __func__, n);
1591                 goto out_err;
1592         }
1593         if (!(p = rpcauth_checkverf(task, p))) {
1594                 dprintk("RPC: %5u %s: auth check failed\n",
1595                                 task->tk_pid, __func__);
1596                 goto out_garbage;               /* bad verifier, retry */
1597         }
1598         len = p - (__be32 *)iov->iov_base - 1;
1599         if (len < 0)
1600                 goto out_overflow;
1601         switch ((n = ntohl(*p++))) {
1602         case RPC_SUCCESS:
1603                 return p;
1604         case RPC_PROG_UNAVAIL:
1605                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1606                                 task->tk_pid, __func__,
1607                                 (unsigned int)task->tk_client->cl_prog,
1608                                 task->tk_client->cl_server);
1609                 error = -EPFNOSUPPORT;
1610                 goto out_err;
1611         case RPC_PROG_MISMATCH:
1612                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1613                                 "server %s\n", task->tk_pid, __func__,
1614                                 (unsigned int)task->tk_client->cl_prog,
1615                                 (unsigned int)task->tk_client->cl_vers,
1616                                 task->tk_client->cl_server);
1617                 error = -EPROTONOSUPPORT;
1618                 goto out_err;
1619         case RPC_PROC_UNAVAIL:
1620                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1621                                 "version %u on server %s\n",
1622                                 task->tk_pid, __func__,
1623                                 rpc_proc_name(task),
1624                                 task->tk_client->cl_prog,
1625                                 task->tk_client->cl_vers,
1626                                 task->tk_client->cl_server);
1627                 error = -EOPNOTSUPP;
1628                 goto out_err;
1629         case RPC_GARBAGE_ARGS:
1630                 dprintk("RPC: %5u %s: server saw garbage\n",
1631                                 task->tk_pid, __func__);
1632                 break;                  /* retry */
1633         default:
1634                 dprintk("RPC: %5u %s: server accept status: %x\n",
1635                                 task->tk_pid, __func__, n);
1636                 /* Also retry */
1637         }
1638
1639 out_garbage:
1640         task->tk_client->cl_stats->rpcgarbage++;
1641         if (task->tk_garb_retry) {
1642                 task->tk_garb_retry--;
1643                 dprintk("RPC: %5u %s: retrying\n",
1644                                 task->tk_pid, __func__);
1645                 task->tk_action = call_bind;
1646 out_retry:
1647                 return ERR_PTR(-EAGAIN);
1648         }
1649 out_eio:
1650         error = -EIO;
1651 out_err:
1652         rpc_exit(task, error);
1653         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1654                         __func__, error);
1655         return ERR_PTR(error);
1656 out_overflow:
1657         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1658                         __func__);
1659         goto out_garbage;
1660 }
1661
1662 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1663 {
1664         return 0;
1665 }
1666
1667 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1668 {
1669         return 0;
1670 }
1671
1672 static struct rpc_procinfo rpcproc_null = {
1673         .p_encode = rpcproc_encode_null,
1674         .p_decode = rpcproc_decode_null,
1675 };
1676
1677 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1678 {
1679         struct rpc_message msg = {
1680                 .rpc_proc = &rpcproc_null,
1681         };
1682         int err;
1683         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1684         err = rpc_call_sync(clnt, &msg, flags);
1685         put_rpccred(msg.rpc_cred);
1686         return err;
1687 }
1688
1689 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1690 {
1691         struct rpc_message msg = {
1692                 .rpc_proc = &rpcproc_null,
1693                 .rpc_cred = cred,
1694         };
1695         struct rpc_task_setup task_setup_data = {
1696                 .rpc_client = clnt,
1697                 .rpc_message = &msg,
1698                 .callback_ops = &rpc_default_ops,
1699                 .flags = flags,
1700         };
1701         return rpc_run_task(&task_setup_data);
1702 }
1703 EXPORT_SYMBOL_GPL(rpc_call_null);
1704
1705 #ifdef RPC_DEBUG
1706 static void rpc_show_header(void)
1707 {
1708         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1709                 "-timeout ---ops--\n");
1710 }
1711
1712 static void rpc_show_task(const struct rpc_clnt *clnt,
1713                           const struct rpc_task *task)
1714 {
1715         const char *rpc_waitq = "none";
1716         char *p, action[KSYM_SYMBOL_LEN];
1717
1718         if (RPC_IS_QUEUED(task))
1719                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1720
1721         /* map tk_action pointer to a function name; then trim off
1722          * the "+0x0 [sunrpc]" */
1723         sprint_symbol(action, (unsigned long)task->tk_action);
1724         p = strchr(action, '+');
1725         if (p)
1726                 *p = '\0';
1727
1728         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1729                 task->tk_pid, task->tk_flags, task->tk_status,
1730                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1731                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1732                 action, rpc_waitq);
1733 }
1734
1735 void rpc_show_tasks(void)
1736 {
1737         struct rpc_clnt *clnt;
1738         struct rpc_task *task;
1739         int header = 0;
1740
1741         spin_lock(&rpc_client_lock);
1742         list_for_each_entry(clnt, &all_clients, cl_clients) {
1743                 spin_lock(&clnt->cl_lock);
1744                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1745                         if (!header) {
1746                                 rpc_show_header();
1747                                 header++;
1748                         }
1749                         rpc_show_task(clnt, task);
1750                 }
1751                 spin_unlock(&clnt->cl_lock);
1752         }
1753         spin_unlock(&rpc_client_lock);
1754 }
1755 #endif