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