net: Move && and || to end of previous line
[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  * @req: RPC request
644  * @tk_ops: RPC call ops
645  */
646 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
647                                 const struct rpc_call_ops *tk_ops)
648 {
649         struct rpc_task *task;
650         struct xdr_buf *xbufp = &req->rq_snd_buf;
651         struct rpc_task_setup task_setup_data = {
652                 .callback_ops = tk_ops,
653         };
654
655         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
656         /*
657          * Create an rpc_task to send the data
658          */
659         task = rpc_new_task(&task_setup_data);
660         if (!task) {
661                 xprt_free_bc_request(req);
662                 goto out;
663         }
664         task->tk_rqstp = req;
665
666         /*
667          * Set up the xdr_buf length.
668          * This also indicates that the buffer is XDR encoded already.
669          */
670         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
671                         xbufp->tail[0].iov_len;
672
673         task->tk_action = call_bc_transmit;
674         atomic_inc(&task->tk_count);
675         BUG_ON(atomic_read(&task->tk_count) != 2);
676         rpc_execute(task);
677
678 out:
679         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
680         return task;
681 }
682 #endif /* CONFIG_NFS_V4_1 */
683
684 void
685 rpc_call_start(struct rpc_task *task)
686 {
687         task->tk_action = call_start;
688 }
689 EXPORT_SYMBOL_GPL(rpc_call_start);
690
691 /**
692  * rpc_peeraddr - extract remote peer address from clnt's xprt
693  * @clnt: RPC client structure
694  * @buf: target buffer
695  * @bufsize: length of target buffer
696  *
697  * Returns the number of bytes that are actually in the stored address.
698  */
699 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
700 {
701         size_t bytes;
702         struct rpc_xprt *xprt = clnt->cl_xprt;
703
704         bytes = sizeof(xprt->addr);
705         if (bytes > bufsize)
706                 bytes = bufsize;
707         memcpy(buf, &clnt->cl_xprt->addr, bytes);
708         return xprt->addrlen;
709 }
710 EXPORT_SYMBOL_GPL(rpc_peeraddr);
711
712 /**
713  * rpc_peeraddr2str - return remote peer address in printable format
714  * @clnt: RPC client structure
715  * @format: address format
716  *
717  */
718 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
719                              enum rpc_display_format_t format)
720 {
721         struct rpc_xprt *xprt = clnt->cl_xprt;
722
723         if (xprt->address_strings[format] != NULL)
724                 return xprt->address_strings[format];
725         else
726                 return "unprintable";
727 }
728 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
729
730 void
731 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
732 {
733         struct rpc_xprt *xprt = clnt->cl_xprt;
734         if (xprt->ops->set_buffer_size)
735                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
736 }
737 EXPORT_SYMBOL_GPL(rpc_setbufsize);
738
739 /*
740  * Return size of largest payload RPC client can support, in bytes
741  *
742  * For stream transports, this is one RPC record fragment (see RFC
743  * 1831), as we don't support multi-record requests yet.  For datagram
744  * transports, this is the size of an IP packet minus the IP, UDP, and
745  * RPC header sizes.
746  */
747 size_t rpc_max_payload(struct rpc_clnt *clnt)
748 {
749         return clnt->cl_xprt->max_payload;
750 }
751 EXPORT_SYMBOL_GPL(rpc_max_payload);
752
753 /**
754  * rpc_force_rebind - force transport to check that remote port is unchanged
755  * @clnt: client to rebind
756  *
757  */
758 void rpc_force_rebind(struct rpc_clnt *clnt)
759 {
760         if (clnt->cl_autobind)
761                 xprt_clear_bound(clnt->cl_xprt);
762 }
763 EXPORT_SYMBOL_GPL(rpc_force_rebind);
764
765 /*
766  * Restart an (async) RPC call from the call_prepare state.
767  * Usually called from within the exit handler.
768  */
769 void
770 rpc_restart_call_prepare(struct rpc_task *task)
771 {
772         if (RPC_ASSASSINATED(task))
773                 return;
774         task->tk_action = rpc_prepare_task;
775 }
776 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
777
778 /*
779  * Restart an (async) RPC call. Usually called from within the
780  * exit handler.
781  */
782 void
783 rpc_restart_call(struct rpc_task *task)
784 {
785         if (RPC_ASSASSINATED(task))
786                 return;
787
788         task->tk_action = call_start;
789 }
790 EXPORT_SYMBOL_GPL(rpc_restart_call);
791
792 #ifdef RPC_DEBUG
793 static const char *rpc_proc_name(const struct rpc_task *task)
794 {
795         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
796
797         if (proc) {
798                 if (proc->p_name)
799                         return proc->p_name;
800                 else
801                         return "NULL";
802         } else
803                 return "no proc";
804 }
805 #endif
806
807 /*
808  * 0.  Initial state
809  *
810  *     Other FSM states can be visited zero or more times, but
811  *     this state is visited exactly once for each RPC.
812  */
813 static void
814 call_start(struct rpc_task *task)
815 {
816         struct rpc_clnt *clnt = task->tk_client;
817
818         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
819                         clnt->cl_protname, clnt->cl_vers,
820                         rpc_proc_name(task),
821                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
822
823         /* Increment call count */
824         task->tk_msg.rpc_proc->p_count++;
825         clnt->cl_stats->rpccnt++;
826         task->tk_action = call_reserve;
827 }
828
829 /*
830  * 1.   Reserve an RPC call slot
831  */
832 static void
833 call_reserve(struct rpc_task *task)
834 {
835         dprint_status(task);
836
837         if (!rpcauth_uptodatecred(task)) {
838                 task->tk_action = call_refresh;
839                 return;
840         }
841
842         task->tk_status  = 0;
843         task->tk_action  = call_reserveresult;
844         xprt_reserve(task);
845 }
846
847 /*
848  * 1b.  Grok the result of xprt_reserve()
849  */
850 static void
851 call_reserveresult(struct rpc_task *task)
852 {
853         int status = task->tk_status;
854
855         dprint_status(task);
856
857         /*
858          * After a call to xprt_reserve(), we must have either
859          * a request slot or else an error status.
860          */
861         task->tk_status = 0;
862         if (status >= 0) {
863                 if (task->tk_rqstp) {
864                         task->tk_action = call_allocate;
865                         return;
866                 }
867
868                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
869                                 __func__, status);
870                 rpc_exit(task, -EIO);
871                 return;
872         }
873
874         /*
875          * Even though there was an error, we may have acquired
876          * a request slot somehow.  Make sure not to leak it.
877          */
878         if (task->tk_rqstp) {
879                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
880                                 __func__, status);
881                 xprt_release(task);
882         }
883
884         switch (status) {
885         case -EAGAIN:   /* woken up; retry */
886                 task->tk_action = call_reserve;
887                 return;
888         case -EIO:      /* probably a shutdown */
889                 break;
890         default:
891                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
892                                 __func__, status);
893                 break;
894         }
895         rpc_exit(task, status);
896 }
897
898 /*
899  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
900  *      (Note: buffer memory is freed in xprt_release).
901  */
902 static void
903 call_allocate(struct rpc_task *task)
904 {
905         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
906         struct rpc_rqst *req = task->tk_rqstp;
907         struct rpc_xprt *xprt = task->tk_xprt;
908         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
909
910         dprint_status(task);
911
912         task->tk_status = 0;
913         task->tk_action = call_bind;
914
915         if (req->rq_buffer)
916                 return;
917
918         if (proc->p_proc != 0) {
919                 BUG_ON(proc->p_arglen == 0);
920                 if (proc->p_decode != NULL)
921                         BUG_ON(proc->p_replen == 0);
922         }
923
924         /*
925          * Calculate the size (in quads) of the RPC call
926          * and reply headers, and convert both values
927          * to byte sizes.
928          */
929         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
930         req->rq_callsize <<= 2;
931         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
932         req->rq_rcvsize <<= 2;
933
934         req->rq_buffer = xprt->ops->buf_alloc(task,
935                                         req->rq_callsize + req->rq_rcvsize);
936         if (req->rq_buffer != NULL)
937                 return;
938
939         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
940
941         if (RPC_IS_ASYNC(task) || !signalled()) {
942                 task->tk_action = call_allocate;
943                 rpc_delay(task, HZ>>4);
944                 return;
945         }
946
947         rpc_exit(task, -ERESTARTSYS);
948 }
949
950 static inline int
951 rpc_task_need_encode(struct rpc_task *task)
952 {
953         return task->tk_rqstp->rq_snd_buf.len == 0;
954 }
955
956 static inline void
957 rpc_task_force_reencode(struct rpc_task *task)
958 {
959         task->tk_rqstp->rq_snd_buf.len = 0;
960         task->tk_rqstp->rq_bytes_sent = 0;
961 }
962
963 static inline void
964 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
965 {
966         buf->head[0].iov_base = start;
967         buf->head[0].iov_len = len;
968         buf->tail[0].iov_len = 0;
969         buf->page_len = 0;
970         buf->flags = 0;
971         buf->len = 0;
972         buf->buflen = len;
973 }
974
975 /*
976  * 3.   Encode arguments of an RPC call
977  */
978 static void
979 rpc_xdr_encode(struct rpc_task *task)
980 {
981         struct rpc_rqst *req = task->tk_rqstp;
982         kxdrproc_t      encode;
983         __be32          *p;
984
985         dprint_status(task);
986
987         rpc_xdr_buf_init(&req->rq_snd_buf,
988                          req->rq_buffer,
989                          req->rq_callsize);
990         rpc_xdr_buf_init(&req->rq_rcv_buf,
991                          (char *)req->rq_buffer + req->rq_callsize,
992                          req->rq_rcvsize);
993
994         p = rpc_encode_header(task);
995         if (p == NULL) {
996                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
997                 rpc_exit(task, -EIO);
998                 return;
999         }
1000
1001         encode = task->tk_msg.rpc_proc->p_encode;
1002         if (encode == NULL)
1003                 return;
1004
1005         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1006                         task->tk_msg.rpc_argp);
1007 }
1008
1009 /*
1010  * 4.   Get the server port number if not yet set
1011  */
1012 static void
1013 call_bind(struct rpc_task *task)
1014 {
1015         struct rpc_xprt *xprt = task->tk_xprt;
1016
1017         dprint_status(task);
1018
1019         task->tk_action = call_connect;
1020         if (!xprt_bound(xprt)) {
1021                 task->tk_action = call_bind_status;
1022                 task->tk_timeout = xprt->bind_timeout;
1023                 xprt->ops->rpcbind(task);
1024         }
1025 }
1026
1027 /*
1028  * 4a.  Sort out bind result
1029  */
1030 static void
1031 call_bind_status(struct rpc_task *task)
1032 {
1033         int status = -EIO;
1034
1035         if (task->tk_status >= 0) {
1036                 dprint_status(task);
1037                 task->tk_status = 0;
1038                 task->tk_action = call_connect;
1039                 return;
1040         }
1041
1042         switch (task->tk_status) {
1043         case -ENOMEM:
1044                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1045                 rpc_delay(task, HZ >> 2);
1046                 goto retry_timeout;
1047         case -EACCES:
1048                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1049                                 "unavailable\n", task->tk_pid);
1050                 /* fail immediately if this is an RPC ping */
1051                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1052                         status = -EOPNOTSUPP;
1053                         break;
1054                 }
1055                 rpc_delay(task, 3*HZ);
1056                 goto retry_timeout;
1057         case -ETIMEDOUT:
1058                 dprintk("RPC: %5u rpcbind request timed out\n",
1059                                 task->tk_pid);
1060                 goto retry_timeout;
1061         case -EPFNOSUPPORT:
1062                 /* server doesn't support any rpcbind version we know of */
1063                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
1064                                 task->tk_pid);
1065                 break;
1066         case -EPROTONOSUPPORT:
1067                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1068                                 task->tk_pid);
1069                 task->tk_status = 0;
1070                 task->tk_action = call_bind;
1071                 return;
1072         default:
1073                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1074                                 task->tk_pid, -task->tk_status);
1075         }
1076
1077         rpc_exit(task, status);
1078         return;
1079
1080 retry_timeout:
1081         task->tk_action = call_timeout;
1082 }
1083
1084 /*
1085  * 4b.  Connect to the RPC server
1086  */
1087 static void
1088 call_connect(struct rpc_task *task)
1089 {
1090         struct rpc_xprt *xprt = task->tk_xprt;
1091
1092         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1093                         task->tk_pid, xprt,
1094                         (xprt_connected(xprt) ? "is" : "is not"));
1095
1096         task->tk_action = call_transmit;
1097         if (!xprt_connected(xprt)) {
1098                 task->tk_action = call_connect_status;
1099                 if (task->tk_status < 0)
1100                         return;
1101                 xprt_connect(task);
1102         }
1103 }
1104
1105 /*
1106  * 4c.  Sort out connect result
1107  */
1108 static void
1109 call_connect_status(struct rpc_task *task)
1110 {
1111         struct rpc_clnt *clnt = task->tk_client;
1112         int status = task->tk_status;
1113
1114         dprint_status(task);
1115
1116         task->tk_status = 0;
1117         if (status >= 0 || status == -EAGAIN) {
1118                 clnt->cl_stats->netreconn++;
1119                 task->tk_action = call_transmit;
1120                 return;
1121         }
1122
1123         switch (status) {
1124                 /* if soft mounted, test if we've timed out */
1125         case -ETIMEDOUT:
1126                 task->tk_action = call_timeout;
1127                 break;
1128         default:
1129                 rpc_exit(task, -EIO);
1130         }
1131 }
1132
1133 /*
1134  * 5.   Transmit the RPC request, and wait for reply
1135  */
1136 static void
1137 call_transmit(struct rpc_task *task)
1138 {
1139         dprint_status(task);
1140
1141         task->tk_action = call_status;
1142         if (task->tk_status < 0)
1143                 return;
1144         task->tk_status = xprt_prepare_transmit(task);
1145         if (task->tk_status != 0)
1146                 return;
1147         task->tk_action = call_transmit_status;
1148         /* Encode here so that rpcsec_gss can use correct sequence number. */
1149         if (rpc_task_need_encode(task)) {
1150                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1151                 rpc_xdr_encode(task);
1152                 /* Did the encode result in an error condition? */
1153                 if (task->tk_status != 0) {
1154                         /* Was the error nonfatal? */
1155                         if (task->tk_status == -EAGAIN)
1156                                 rpc_delay(task, HZ >> 4);
1157                         else
1158                                 rpc_exit(task, task->tk_status);
1159                         return;
1160                 }
1161         }
1162         xprt_transmit(task);
1163         if (task->tk_status < 0)
1164                 return;
1165         /*
1166          * On success, ensure that we call xprt_end_transmit() before sleeping
1167          * in order to allow access to the socket to other RPC requests.
1168          */
1169         call_transmit_status(task);
1170         if (rpc_reply_expected(task))
1171                 return;
1172         task->tk_action = rpc_exit_task;
1173         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1174 }
1175
1176 /*
1177  * 5a.  Handle cleanup after a transmission
1178  */
1179 static void
1180 call_transmit_status(struct rpc_task *task)
1181 {
1182         task->tk_action = call_status;
1183         switch (task->tk_status) {
1184         case -EAGAIN:
1185                 break;
1186         default:
1187                 xprt_end_transmit(task);
1188                 /*
1189                  * Special cases: if we've been waiting on the
1190                  * socket's write_space() callback, or if the
1191                  * socket just returned a connection error,
1192                  * then hold onto the transport lock.
1193                  */
1194         case -ECONNREFUSED:
1195         case -ECONNRESET:
1196         case -ENOTCONN:
1197         case -EHOSTDOWN:
1198         case -EHOSTUNREACH:
1199         case -ENETUNREACH:
1200         case -EPIPE:
1201                 rpc_task_force_reencode(task);
1202         }
1203 }
1204
1205 #if defined(CONFIG_NFS_V4_1)
1206 /*
1207  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1208  * addition, disconnect on connectivity errors.
1209  */
1210 static void
1211 call_bc_transmit(struct rpc_task *task)
1212 {
1213         struct rpc_rqst *req = task->tk_rqstp;
1214
1215         BUG_ON(task->tk_status != 0);
1216         task->tk_status = xprt_prepare_transmit(task);
1217         if (task->tk_status == -EAGAIN) {
1218                 /*
1219                  * Could not reserve the transport. Try again after the
1220                  * transport is released.
1221                  */
1222                 task->tk_status = 0;
1223                 task->tk_action = call_bc_transmit;
1224                 return;
1225         }
1226
1227         task->tk_action = rpc_exit_task;
1228         if (task->tk_status < 0) {
1229                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1230                         "error: %d\n", task->tk_status);
1231                 return;
1232         }
1233
1234         xprt_transmit(task);
1235         xprt_end_transmit(task);
1236         dprint_status(task);
1237         switch (task->tk_status) {
1238         case 0:
1239                 /* Success */
1240                 break;
1241         case -EHOSTDOWN:
1242         case -EHOSTUNREACH:
1243         case -ENETUNREACH:
1244         case -ETIMEDOUT:
1245                 /*
1246                  * Problem reaching the server.  Disconnect and let the
1247                  * forechannel reestablish the connection.  The server will
1248                  * have to retransmit the backchannel request and we'll
1249                  * reprocess it.  Since these ops are idempotent, there's no
1250                  * need to cache our reply at this time.
1251                  */
1252                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1253                         "error: %d\n", task->tk_status);
1254                 xprt_conditional_disconnect(task->tk_xprt,
1255                         req->rq_connect_cookie);
1256                 break;
1257         default:
1258                 /*
1259                  * We were unable to reply and will have to drop the
1260                  * request.  The server should reconnect and retransmit.
1261                  */
1262                 BUG_ON(task->tk_status == -EAGAIN);
1263                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1264                         "error: %d\n", task->tk_status);
1265                 break;
1266         }
1267         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1268 }
1269 #endif /* CONFIG_NFS_V4_1 */
1270
1271 /*
1272  * 6.   Sort out the RPC call status
1273  */
1274 static void
1275 call_status(struct rpc_task *task)
1276 {
1277         struct rpc_clnt *clnt = task->tk_client;
1278         struct rpc_rqst *req = task->tk_rqstp;
1279         int             status;
1280
1281         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1282                 task->tk_status = req->rq_reply_bytes_recvd;
1283
1284         dprint_status(task);
1285
1286         status = task->tk_status;
1287         if (status >= 0) {
1288                 task->tk_action = call_decode;
1289                 return;
1290         }
1291
1292         task->tk_status = 0;
1293         switch(status) {
1294         case -EHOSTDOWN:
1295         case -EHOSTUNREACH:
1296         case -ENETUNREACH:
1297                 /*
1298                  * Delay any retries for 3 seconds, then handle as if it
1299                  * were a timeout.
1300                  */
1301                 rpc_delay(task, 3*HZ);
1302         case -ETIMEDOUT:
1303                 task->tk_action = call_timeout;
1304                 if (task->tk_client->cl_discrtry)
1305                         xprt_conditional_disconnect(task->tk_xprt,
1306                                         req->rq_connect_cookie);
1307                 break;
1308         case -ECONNRESET:
1309         case -ECONNREFUSED:
1310                 rpc_force_rebind(clnt);
1311                 rpc_delay(task, 3*HZ);
1312         case -EPIPE:
1313         case -ENOTCONN:
1314                 task->tk_action = call_bind;
1315                 break;
1316         case -EAGAIN:
1317                 task->tk_action = call_transmit;
1318                 break;
1319         case -EIO:
1320                 /* shutdown or soft timeout */
1321                 rpc_exit(task, status);
1322                 break;
1323         default:
1324                 if (clnt->cl_chatty)
1325                         printk("%s: RPC call returned error %d\n",
1326                                clnt->cl_protname, -status);
1327                 rpc_exit(task, status);
1328         }
1329 }
1330
1331 /*
1332  * 6a.  Handle RPC timeout
1333  *      We do not release the request slot, so we keep using the
1334  *      same XID for all retransmits.
1335  */
1336 static void
1337 call_timeout(struct rpc_task *task)
1338 {
1339         struct rpc_clnt *clnt = task->tk_client;
1340
1341         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1342                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1343                 goto retry;
1344         }
1345
1346         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1347         task->tk_timeouts++;
1348
1349         if (RPC_IS_SOFT(task)) {
1350                 if (clnt->cl_chatty)
1351                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1352                                 clnt->cl_protname, clnt->cl_server);
1353                 rpc_exit(task, -EIO);
1354                 return;
1355         }
1356
1357         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1358                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1359                 if (clnt->cl_chatty)
1360                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1361                         clnt->cl_protname, clnt->cl_server);
1362         }
1363         rpc_force_rebind(clnt);
1364         /*
1365          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1366          * event? RFC2203 requires the server to drop all such requests.
1367          */
1368         rpcauth_invalcred(task);
1369
1370 retry:
1371         clnt->cl_stats->rpcretrans++;
1372         task->tk_action = call_bind;
1373         task->tk_status = 0;
1374 }
1375
1376 /*
1377  * 7.   Decode the RPC reply
1378  */
1379 static void
1380 call_decode(struct rpc_task *task)
1381 {
1382         struct rpc_clnt *clnt = task->tk_client;
1383         struct rpc_rqst *req = task->tk_rqstp;
1384         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1385         __be32          *p;
1386
1387         dprintk("RPC: %5u call_decode (status %d)\n",
1388                         task->tk_pid, task->tk_status);
1389
1390         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1391                 if (clnt->cl_chatty)
1392                         printk(KERN_NOTICE "%s: server %s OK\n",
1393                                 clnt->cl_protname, clnt->cl_server);
1394                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1395         }
1396
1397         /*
1398          * Ensure that we see all writes made by xprt_complete_rqst()
1399          * before it changed req->rq_reply_bytes_recvd.
1400          */
1401         smp_rmb();
1402         req->rq_rcv_buf.len = req->rq_private_buf.len;
1403
1404         /* Check that the softirq receive buffer is valid */
1405         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1406                                 sizeof(req->rq_rcv_buf)) != 0);
1407
1408         if (req->rq_rcv_buf.len < 12) {
1409                 if (!RPC_IS_SOFT(task)) {
1410                         task->tk_action = call_bind;
1411                         clnt->cl_stats->rpcretrans++;
1412                         goto out_retry;
1413                 }
1414                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1415                                 clnt->cl_protname, task->tk_status);
1416                 task->tk_action = call_timeout;
1417                 goto out_retry;
1418         }
1419
1420         p = rpc_verify_header(task);
1421         if (IS_ERR(p)) {
1422                 if (p == ERR_PTR(-EAGAIN))
1423                         goto out_retry;
1424                 return;
1425         }
1426
1427         task->tk_action = rpc_exit_task;
1428
1429         if (decode) {
1430                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1431                                                       task->tk_msg.rpc_resp);
1432         }
1433         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1434                         task->tk_status);
1435         return;
1436 out_retry:
1437         task->tk_status = 0;
1438         /* Note: rpc_verify_header() may have freed the RPC slot */
1439         if (task->tk_rqstp == req) {
1440                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1441                 if (task->tk_client->cl_discrtry)
1442                         xprt_conditional_disconnect(task->tk_xprt,
1443                                         req->rq_connect_cookie);
1444         }
1445 }
1446
1447 /*
1448  * 8.   Refresh the credentials if rejected by the server
1449  */
1450 static void
1451 call_refresh(struct rpc_task *task)
1452 {
1453         dprint_status(task);
1454
1455         task->tk_action = call_refreshresult;
1456         task->tk_status = 0;
1457         task->tk_client->cl_stats->rpcauthrefresh++;
1458         rpcauth_refreshcred(task);
1459 }
1460
1461 /*
1462  * 8a.  Process the results of a credential refresh
1463  */
1464 static void
1465 call_refreshresult(struct rpc_task *task)
1466 {
1467         int status = task->tk_status;
1468
1469         dprint_status(task);
1470
1471         task->tk_status = 0;
1472         task->tk_action = call_reserve;
1473         if (status >= 0 && rpcauth_uptodatecred(task))
1474                 return;
1475         if (status == -EACCES) {
1476                 rpc_exit(task, -EACCES);
1477                 return;
1478         }
1479         task->tk_action = call_refresh;
1480         if (status != -ETIMEDOUT)
1481                 rpc_delay(task, 3*HZ);
1482         return;
1483 }
1484
1485 static __be32 *
1486 rpc_encode_header(struct rpc_task *task)
1487 {
1488         struct rpc_clnt *clnt = task->tk_client;
1489         struct rpc_rqst *req = task->tk_rqstp;
1490         __be32          *p = req->rq_svec[0].iov_base;
1491
1492         /* FIXME: check buffer size? */
1493
1494         p = xprt_skip_transport_header(task->tk_xprt, p);
1495         *p++ = req->rq_xid;             /* XID */
1496         *p++ = htonl(RPC_CALL);         /* CALL */
1497         *p++ = htonl(RPC_VERSION);      /* RPC version */
1498         *p++ = htonl(clnt->cl_prog);    /* program number */
1499         *p++ = htonl(clnt->cl_vers);    /* program version */
1500         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1501         p = rpcauth_marshcred(task, p);
1502         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1503         return p;
1504 }
1505
1506 static __be32 *
1507 rpc_verify_header(struct rpc_task *task)
1508 {
1509         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1510         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1511         __be32  *p = iov->iov_base;
1512         u32 n;
1513         int error = -EACCES;
1514
1515         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1516                 /* RFC-1014 says that the representation of XDR data must be a
1517                  * multiple of four bytes
1518                  * - if it isn't pointer subtraction in the NFS client may give
1519                  *   undefined results
1520                  */
1521                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1522                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1523                        task->tk_rqstp->rq_rcv_buf.len);
1524                 goto out_eio;
1525         }
1526         if ((len -= 3) < 0)
1527                 goto out_overflow;
1528
1529         p += 1; /* skip XID */
1530         if ((n = ntohl(*p++)) != RPC_REPLY) {
1531                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1532                         task->tk_pid, __func__, n);
1533                 goto out_garbage;
1534         }
1535
1536         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1537                 if (--len < 0)
1538                         goto out_overflow;
1539                 switch ((n = ntohl(*p++))) {
1540                         case RPC_AUTH_ERROR:
1541                                 break;
1542                         case RPC_MISMATCH:
1543                                 dprintk("RPC: %5u %s: RPC call version "
1544                                                 "mismatch!\n",
1545                                                 task->tk_pid, __func__);
1546                                 error = -EPROTONOSUPPORT;
1547                                 goto out_err;
1548                         default:
1549                                 dprintk("RPC: %5u %s: RPC call rejected, "
1550                                                 "unknown error: %x\n",
1551                                                 task->tk_pid, __func__, n);
1552                                 goto out_eio;
1553                 }
1554                 if (--len < 0)
1555                         goto out_overflow;
1556                 switch ((n = ntohl(*p++))) {
1557                 case RPC_AUTH_REJECTEDCRED:
1558                 case RPC_AUTH_REJECTEDVERF:
1559                 case RPCSEC_GSS_CREDPROBLEM:
1560                 case RPCSEC_GSS_CTXPROBLEM:
1561                         if (!task->tk_cred_retry)
1562                                 break;
1563                         task->tk_cred_retry--;
1564                         dprintk("RPC: %5u %s: retry stale creds\n",
1565                                         task->tk_pid, __func__);
1566                         rpcauth_invalcred(task);
1567                         /* Ensure we obtain a new XID! */
1568                         xprt_release(task);
1569                         task->tk_action = call_refresh;
1570                         goto out_retry;
1571                 case RPC_AUTH_BADCRED:
1572                 case RPC_AUTH_BADVERF:
1573                         /* possibly garbled cred/verf? */
1574                         if (!task->tk_garb_retry)
1575                                 break;
1576                         task->tk_garb_retry--;
1577                         dprintk("RPC: %5u %s: retry garbled creds\n",
1578                                         task->tk_pid, __func__);
1579                         task->tk_action = call_bind;
1580                         goto out_retry;
1581                 case RPC_AUTH_TOOWEAK:
1582                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1583                                "authentication.\n", task->tk_client->cl_server);
1584                         break;
1585                 default:
1586                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1587                                         task->tk_pid, __func__, n);
1588                         error = -EIO;
1589                 }
1590                 dprintk("RPC: %5u %s: call rejected %d\n",
1591                                 task->tk_pid, __func__, n);
1592                 goto out_err;
1593         }
1594         if (!(p = rpcauth_checkverf(task, p))) {
1595                 dprintk("RPC: %5u %s: auth check failed\n",
1596                                 task->tk_pid, __func__);
1597                 goto out_garbage;               /* bad verifier, retry */
1598         }
1599         len = p - (__be32 *)iov->iov_base - 1;
1600         if (len < 0)
1601                 goto out_overflow;
1602         switch ((n = ntohl(*p++))) {
1603         case RPC_SUCCESS:
1604                 return p;
1605         case RPC_PROG_UNAVAIL:
1606                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1607                                 task->tk_pid, __func__,
1608                                 (unsigned int)task->tk_client->cl_prog,
1609                                 task->tk_client->cl_server);
1610                 error = -EPFNOSUPPORT;
1611                 goto out_err;
1612         case RPC_PROG_MISMATCH:
1613                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1614                                 "server %s\n", task->tk_pid, __func__,
1615                                 (unsigned int)task->tk_client->cl_prog,
1616                                 (unsigned int)task->tk_client->cl_vers,
1617                                 task->tk_client->cl_server);
1618                 error = -EPROTONOSUPPORT;
1619                 goto out_err;
1620         case RPC_PROC_UNAVAIL:
1621                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1622                                 "version %u on server %s\n",
1623                                 task->tk_pid, __func__,
1624                                 rpc_proc_name(task),
1625                                 task->tk_client->cl_prog,
1626                                 task->tk_client->cl_vers,
1627                                 task->tk_client->cl_server);
1628                 error = -EOPNOTSUPP;
1629                 goto out_err;
1630         case RPC_GARBAGE_ARGS:
1631                 dprintk("RPC: %5u %s: server saw garbage\n",
1632                                 task->tk_pid, __func__);
1633                 break;                  /* retry */
1634         default:
1635                 dprintk("RPC: %5u %s: server accept status: %x\n",
1636                                 task->tk_pid, __func__, n);
1637                 /* Also retry */
1638         }
1639
1640 out_garbage:
1641         task->tk_client->cl_stats->rpcgarbage++;
1642         if (task->tk_garb_retry) {
1643                 task->tk_garb_retry--;
1644                 dprintk("RPC: %5u %s: retrying\n",
1645                                 task->tk_pid, __func__);
1646                 task->tk_action = call_bind;
1647 out_retry:
1648                 return ERR_PTR(-EAGAIN);
1649         }
1650 out_eio:
1651         error = -EIO;
1652 out_err:
1653         rpc_exit(task, error);
1654         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1655                         __func__, error);
1656         return ERR_PTR(error);
1657 out_overflow:
1658         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1659                         __func__);
1660         goto out_garbage;
1661 }
1662
1663 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1664 {
1665         return 0;
1666 }
1667
1668 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1669 {
1670         return 0;
1671 }
1672
1673 static struct rpc_procinfo rpcproc_null = {
1674         .p_encode = rpcproc_encode_null,
1675         .p_decode = rpcproc_decode_null,
1676 };
1677
1678 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1679 {
1680         struct rpc_message msg = {
1681                 .rpc_proc = &rpcproc_null,
1682         };
1683         int err;
1684         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1685         err = rpc_call_sync(clnt, &msg, flags);
1686         put_rpccred(msg.rpc_cred);
1687         return err;
1688 }
1689
1690 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1691 {
1692         struct rpc_message msg = {
1693                 .rpc_proc = &rpcproc_null,
1694                 .rpc_cred = cred,
1695         };
1696         struct rpc_task_setup task_setup_data = {
1697                 .rpc_client = clnt,
1698                 .rpc_message = &msg,
1699                 .callback_ops = &rpc_default_ops,
1700                 .flags = flags,
1701         };
1702         return rpc_run_task(&task_setup_data);
1703 }
1704 EXPORT_SYMBOL_GPL(rpc_call_null);
1705
1706 #ifdef RPC_DEBUG
1707 static void rpc_show_header(void)
1708 {
1709         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1710                 "-timeout ---ops--\n");
1711 }
1712
1713 static void rpc_show_task(const struct rpc_clnt *clnt,
1714                           const struct rpc_task *task)
1715 {
1716         const char *rpc_waitq = "none";
1717         char *p, action[KSYM_SYMBOL_LEN];
1718
1719         if (RPC_IS_QUEUED(task))
1720                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1721
1722         /* map tk_action pointer to a function name; then trim off
1723          * the "+0x0 [sunrpc]" */
1724         sprint_symbol(action, (unsigned long)task->tk_action);
1725         p = strchr(action, '+');
1726         if (p)
1727                 *p = '\0';
1728
1729         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1730                 task->tk_pid, task->tk_flags, task->tk_status,
1731                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1732                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1733                 action, rpc_waitq);
1734 }
1735
1736 void rpc_show_tasks(void)
1737 {
1738         struct rpc_clnt *clnt;
1739         struct rpc_task *task;
1740         int header = 0;
1741
1742         spin_lock(&rpc_client_lock);
1743         list_for_each_entry(clnt, &all_clients, cl_clients) {
1744                 spin_lock(&clnt->cl_lock);
1745                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1746                         if (!header) {
1747                                 rpc_show_header();
1748                                 header++;
1749                         }
1750                         rpc_show_task(clnt, task);
1751                 }
1752                 spin_unlock(&clnt->cl_lock);
1753         }
1754         spin_unlock(&rpc_client_lock);
1755 }
1756 #endif