RPC: Clean up RPC task structure
[linux-2.6.git] / net / sunrpc / clnt.c
1 /*
2  *  linux/net/sunrpc/clnt.c
3  *
4  *  This file contains the high-level RPC interface.
5  *  It is modeled as a finite state machine to support both synchronous
6  *  and asynchronous requests.
7  *
8  *  -   RPC header generation and argument serialization.
9  *  -   Credential refresh.
10  *  -   TCP connect handling.
11  *  -   Retry of operation when it is suspected the operation failed because
12  *      of uid squashing on the server, or when the credentials were stale
13  *      and need to be refreshed, or when a packet was damaged in transit.
14  *      This may be have to be moved to the VFS layer.
15  *
16  *  NB: BSD uses a more intelligent approach to guessing when a request
17  *  or reply has been lost by keeping the RTO estimate for each procedure.
18  *  We currently make do with a constant timeout value.
19  *
20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
22  */
23
24 #include <asm/system.h>
25
26 #include <linux/module.h>
27 #include <linux/types.h>
28 #include <linux/mm.h>
29 #include <linux/slab.h>
30 #include <linux/utsname.h>
31
32 #include <linux/sunrpc/clnt.h>
33 #include <linux/workqueue.h>
34 #include <linux/sunrpc/rpc_pipe_fs.h>
35
36 #include <linux/nfs.h>
37
38
39 #define RPC_SLACK_SPACE         (1024)  /* total overkill */
40
41 #ifdef RPC_DEBUG
42 # define RPCDBG_FACILITY        RPCDBG_CALL
43 #endif
44
45 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
46
47
48 static void     call_start(struct rpc_task *task);
49 static void     call_reserve(struct rpc_task *task);
50 static void     call_reserveresult(struct rpc_task *task);
51 static void     call_allocate(struct rpc_task *task);
52 static void     call_encode(struct rpc_task *task);
53 static void     call_decode(struct rpc_task *task);
54 static void     call_bind(struct rpc_task *task);
55 static void     call_bind_status(struct rpc_task *task);
56 static void     call_transmit(struct rpc_task *task);
57 static void     call_status(struct rpc_task *task);
58 static void     call_transmit_status(struct rpc_task *task);
59 static void     call_refresh(struct rpc_task *task);
60 static void     call_refreshresult(struct rpc_task *task);
61 static void     call_timeout(struct rpc_task *task);
62 static void     call_connect(struct rpc_task *task);
63 static void     call_connect_status(struct rpc_task *task);
64 static u32 *    call_header(struct rpc_task *task);
65 static u32 *    call_verify(struct rpc_task *task);
66
67
68 static int
69 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
70 {
71         static uint32_t clntid;
72         int error;
73
74         if (dir_name == NULL)
75                 return 0;
76         for (;;) {
77                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
78                                 "%s/clnt%x", dir_name,
79                                 (unsigned int)clntid++);
80                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
81                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
82                 if (!IS_ERR(clnt->cl_dentry))
83                         return 0;
84                 error = PTR_ERR(clnt->cl_dentry);
85                 if (error != -EEXIST) {
86                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
87                                         clnt->cl_pathname, error);
88                         return error;
89                 }
90         }
91 }
92
93 /*
94  * Create an RPC client
95  * FIXME: This should also take a flags argument (as in task->tk_flags).
96  * It's called (among others) from pmap_create_client, which may in
97  * turn be called by an async task. In this case, rpciod should not be
98  * made to sleep too long.
99  */
100 struct rpc_clnt *
101 rpc_new_client(struct rpc_xprt *xprt, char *servname,
102                   struct rpc_program *program, u32 vers,
103                   rpc_authflavor_t flavor)
104 {
105         struct rpc_version      *version;
106         struct rpc_clnt         *clnt = NULL;
107         struct rpc_auth         *auth;
108         int err;
109         int len;
110
111         dprintk("RPC: creating %s client for %s (xprt %p)\n",
112                 program->name, servname, xprt);
113
114         err = -EINVAL;
115         if (!xprt)
116                 goto out_err;
117         if (vers >= program->nrvers || !(version = program->version[vers]))
118                 goto out_err;
119
120         err = -ENOMEM;
121         clnt = (struct rpc_clnt *) kmalloc(sizeof(*clnt), GFP_KERNEL);
122         if (!clnt)
123                 goto out_err;
124         memset(clnt, 0, sizeof(*clnt));
125         atomic_set(&clnt->cl_users, 0);
126         atomic_set(&clnt->cl_count, 1);
127         clnt->cl_parent = clnt;
128
129         clnt->cl_server = clnt->cl_inline_name;
130         len = strlen(servname) + 1;
131         if (len > sizeof(clnt->cl_inline_name)) {
132                 char *buf = kmalloc(len, GFP_KERNEL);
133                 if (buf != 0)
134                         clnt->cl_server = buf;
135                 else
136                         len = sizeof(clnt->cl_inline_name);
137         }
138         strlcpy(clnt->cl_server, servname, len);
139
140         clnt->cl_xprt     = xprt;
141         clnt->cl_procinfo = version->procs;
142         clnt->cl_maxproc  = version->nrprocs;
143         clnt->cl_protname = program->name;
144         clnt->cl_pmap     = &clnt->cl_pmap_default;
145         clnt->cl_port     = xprt->addr.sin_port;
146         clnt->cl_prog     = program->number;
147         clnt->cl_vers     = version->number;
148         clnt->cl_prot     = xprt->prot;
149         clnt->cl_stats    = program->stats;
150         rpc_init_wait_queue(&clnt->cl_pmap_default.pm_bindwait, "bindwait");
151
152         if (!clnt->cl_port)
153                 clnt->cl_autobind = 1;
154
155         clnt->cl_rtt = &clnt->cl_rtt_default;
156         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
157
158         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
159         if (err < 0)
160                 goto out_no_path;
161
162         auth = rpcauth_create(flavor, clnt);
163         if (IS_ERR(auth)) {
164                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
165                                 flavor);
166                 err = PTR_ERR(auth);
167                 goto out_no_auth;
168         }
169
170         /* save the nodename */
171         clnt->cl_nodelen = strlen(system_utsname.nodename);
172         if (clnt->cl_nodelen > UNX_MAXNODENAME)
173                 clnt->cl_nodelen = UNX_MAXNODENAME;
174         memcpy(clnt->cl_nodename, system_utsname.nodename, clnt->cl_nodelen);
175         return clnt;
176
177 out_no_auth:
178         rpc_rmdir(clnt->cl_pathname);
179 out_no_path:
180         if (clnt->cl_server != clnt->cl_inline_name)
181                 kfree(clnt->cl_server);
182         kfree(clnt);
183 out_err:
184         xprt_destroy(xprt);
185         return ERR_PTR(err);
186 }
187
188 /**
189  * Create an RPC client
190  * @xprt - pointer to xprt struct
191  * @servname - name of server
192  * @info - rpc_program
193  * @version - rpc_program version
194  * @authflavor - rpc_auth flavour to use
195  *
196  * Creates an RPC client structure, then pings the server in order to
197  * determine if it is up, and if it supports this program and version.
198  *
199  * This function should never be called by asynchronous tasks such as
200  * the portmapper.
201  */
202 struct rpc_clnt *rpc_create_client(struct rpc_xprt *xprt, char *servname,
203                 struct rpc_program *info, u32 version, rpc_authflavor_t authflavor)
204 {
205         struct rpc_clnt *clnt;
206         int err;
207         
208         clnt = rpc_new_client(xprt, servname, info, version, authflavor);
209         if (IS_ERR(clnt))
210                 return clnt;
211         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
212         if (err == 0)
213                 return clnt;
214         rpc_shutdown_client(clnt);
215         return ERR_PTR(err);
216 }
217
218 /*
219  * This function clones the RPC client structure. It allows us to share the
220  * same transport while varying parameters such as the authentication
221  * flavour.
222  */
223 struct rpc_clnt *
224 rpc_clone_client(struct rpc_clnt *clnt)
225 {
226         struct rpc_clnt *new;
227
228         new = (struct rpc_clnt *)kmalloc(sizeof(*new), GFP_KERNEL);
229         if (!new)
230                 goto out_no_clnt;
231         memcpy(new, clnt, sizeof(*new));
232         atomic_set(&new->cl_count, 1);
233         atomic_set(&new->cl_users, 0);
234         new->cl_parent = clnt;
235         atomic_inc(&clnt->cl_count);
236         /* Duplicate portmapper */
237         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
238         /* Turn off autobind on clones */
239         new->cl_autobind = 0;
240         new->cl_oneshot = 0;
241         new->cl_dead = 0;
242         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
243         if (new->cl_auth)
244                 atomic_inc(&new->cl_auth->au_count);
245         new->cl_pmap            = &new->cl_pmap_default;
246         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
247         return new;
248 out_no_clnt:
249         printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
250         return ERR_PTR(-ENOMEM);
251 }
252
253 /*
254  * Properly shut down an RPC client, terminating all outstanding
255  * requests. Note that we must be certain that cl_oneshot and
256  * cl_dead are cleared, or else the client would be destroyed
257  * when the last task releases it.
258  */
259 int
260 rpc_shutdown_client(struct rpc_clnt *clnt)
261 {
262         dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
263                         clnt->cl_protname, clnt->cl_server,
264                         atomic_read(&clnt->cl_users));
265
266         while (atomic_read(&clnt->cl_users) > 0) {
267                 /* Don't let rpc_release_client destroy us */
268                 clnt->cl_oneshot = 0;
269                 clnt->cl_dead = 0;
270                 rpc_killall_tasks(clnt);
271                 sleep_on_timeout(&destroy_wait, 1*HZ);
272         }
273
274         if (atomic_read(&clnt->cl_users) < 0) {
275                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
276                                 clnt, atomic_read(&clnt->cl_users));
277 #ifdef RPC_DEBUG
278                 rpc_show_tasks();
279 #endif
280                 BUG();
281         }
282
283         return rpc_destroy_client(clnt);
284 }
285
286 /*
287  * Delete an RPC client
288  */
289 int
290 rpc_destroy_client(struct rpc_clnt *clnt)
291 {
292         if (!atomic_dec_and_test(&clnt->cl_count))
293                 return 1;
294         BUG_ON(atomic_read(&clnt->cl_users) != 0);
295
296         dprintk("RPC: destroying %s client for %s\n",
297                         clnt->cl_protname, clnt->cl_server);
298         if (clnt->cl_auth) {
299                 rpcauth_destroy(clnt->cl_auth);
300                 clnt->cl_auth = NULL;
301         }
302         if (clnt->cl_parent != clnt) {
303                 rpc_destroy_client(clnt->cl_parent);
304                 goto out_free;
305         }
306         if (clnt->cl_pathname[0])
307                 rpc_rmdir(clnt->cl_pathname);
308         if (clnt->cl_xprt) {
309                 xprt_destroy(clnt->cl_xprt);
310                 clnt->cl_xprt = NULL;
311         }
312         if (clnt->cl_server != clnt->cl_inline_name)
313                 kfree(clnt->cl_server);
314 out_free:
315         kfree(clnt);
316         return 0;
317 }
318
319 /*
320  * Release an RPC client
321  */
322 void
323 rpc_release_client(struct rpc_clnt *clnt)
324 {
325         dprintk("RPC:      rpc_release_client(%p, %d)\n",
326                                 clnt, atomic_read(&clnt->cl_users));
327
328         if (!atomic_dec_and_test(&clnt->cl_users))
329                 return;
330         wake_up(&destroy_wait);
331         if (clnt->cl_oneshot || clnt->cl_dead)
332                 rpc_destroy_client(clnt);
333 }
334
335 /**
336  * rpc_bind_new_program - bind a new RPC program to an existing client
337  * @old - old rpc_client
338  * @program - rpc program to set
339  * @vers - rpc program version
340  *
341  * Clones the rpc client and sets up a new RPC program. This is mainly
342  * of use for enabling different RPC programs to share the same transport.
343  * The Sun NFSv2/v3 ACL protocol can do this.
344  */
345 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
346                                       struct rpc_program *program,
347                                       int vers)
348 {
349         struct rpc_clnt *clnt;
350         struct rpc_version *version;
351         int err;
352
353         BUG_ON(vers >= program->nrvers || !program->version[vers]);
354         version = program->version[vers];
355         clnt = rpc_clone_client(old);
356         if (IS_ERR(clnt))
357                 goto out;
358         clnt->cl_procinfo = version->procs;
359         clnt->cl_maxproc  = version->nrprocs;
360         clnt->cl_protname = program->name;
361         clnt->cl_prog     = program->number;
362         clnt->cl_vers     = version->number;
363         clnt->cl_stats    = program->stats;
364         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
365         if (err != 0) {
366                 rpc_shutdown_client(clnt);
367                 clnt = ERR_PTR(err);
368         }
369 out:    
370         return clnt;
371 }
372
373 /*
374  * Default callback for async RPC calls
375  */
376 static void
377 rpc_default_callback(struct rpc_task *task, void *data)
378 {
379 }
380
381 static const struct rpc_call_ops rpc_default_ops = {
382         .rpc_call_done = rpc_default_callback,
383 };
384
385 /*
386  *      Export the signal mask handling for synchronous code that
387  *      sleeps on RPC calls
388  */
389 #define RPC_INTR_SIGNALS (sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGKILL))
390  
391 static void rpc_save_sigmask(sigset_t *oldset, int intr)
392 {
393         unsigned long   sigallow = 0;
394         sigset_t sigmask;
395
396         /* Block all signals except those listed in sigallow */
397         if (intr)
398                 sigallow |= RPC_INTR_SIGNALS;
399         siginitsetinv(&sigmask, sigallow);
400         sigprocmask(SIG_BLOCK, &sigmask, oldset);
401 }
402
403 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
404 {
405         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
406 }
407
408 static inline void rpc_restore_sigmask(sigset_t *oldset)
409 {
410         sigprocmask(SIG_SETMASK, oldset, NULL);
411 }
412
413 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
414 {
415         rpc_save_sigmask(oldset, clnt->cl_intr);
416 }
417
418 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
419 {
420         rpc_restore_sigmask(oldset);
421 }
422
423 /*
424  * New rpc_call implementation
425  */
426 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
427 {
428         struct rpc_task *task;
429         sigset_t        oldset;
430         int             status;
431
432         /* If this client is slain all further I/O fails */
433         if (clnt->cl_dead) 
434                 return -EIO;
435
436         BUG_ON(flags & RPC_TASK_ASYNC);
437
438         status = -ENOMEM;
439         task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL);
440         if (task == NULL)
441                 goto out;
442
443         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
444         rpc_task_sigmask(task, &oldset);
445
446         rpc_call_setup(task, msg, 0);
447
448         /* Set up the call info struct and execute the task */
449         if (task->tk_status == 0) {
450                 status = rpc_execute(task);
451         } else {
452                 status = task->tk_status;
453                 rpc_release_task(task);
454         }
455
456         rpc_restore_sigmask(&oldset);
457 out:
458         return status;
459 }
460
461 /*
462  * New rpc_call implementation
463  */
464 int
465 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
466                const struct rpc_call_ops *tk_ops, void *data)
467 {
468         struct rpc_task *task;
469         sigset_t        oldset;
470         int             status;
471
472         /* If this client is slain all further I/O fails */
473         if (clnt->cl_dead) 
474                 return -EIO;
475
476         flags |= RPC_TASK_ASYNC;
477
478         /* Create/initialize a new RPC task */
479         status = -ENOMEM;
480         if (!(task = rpc_new_task(clnt, flags, tk_ops, data)))
481                 goto out;
482
483         /* Mask signals on GSS_AUTH upcalls */
484         rpc_task_sigmask(task, &oldset);                
485
486         rpc_call_setup(task, msg, 0);
487
488         /* Set up the call info struct and execute the task */
489         status = task->tk_status;
490         if (status == 0)
491                 rpc_execute(task);
492         else
493                 rpc_release_task(task);
494
495         rpc_restore_sigmask(&oldset);           
496 out:
497         return status;
498 }
499
500
501 void
502 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
503 {
504         task->tk_msg   = *msg;
505         task->tk_flags |= flags;
506         /* Bind the user cred */
507         if (task->tk_msg.rpc_cred != NULL)
508                 rpcauth_holdcred(task);
509         else
510                 rpcauth_bindcred(task);
511
512         if (task->tk_status == 0)
513                 task->tk_action = call_start;
514         else
515                 task->tk_action = rpc_exit_task;
516 }
517
518 void
519 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
520 {
521         struct rpc_xprt *xprt = clnt->cl_xprt;
522         if (xprt->ops->set_buffer_size)
523                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
524 }
525
526 /*
527  * Return size of largest payload RPC client can support, in bytes
528  *
529  * For stream transports, this is one RPC record fragment (see RFC
530  * 1831), as we don't support multi-record requests yet.  For datagram
531  * transports, this is the size of an IP packet minus the IP, UDP, and
532  * RPC header sizes.
533  */
534 size_t rpc_max_payload(struct rpc_clnt *clnt)
535 {
536         return clnt->cl_xprt->max_payload;
537 }
538 EXPORT_SYMBOL(rpc_max_payload);
539
540 /*
541  * Restart an (async) RPC call. Usually called from within the
542  * exit handler.
543  */
544 void
545 rpc_restart_call(struct rpc_task *task)
546 {
547         if (RPC_ASSASSINATED(task))
548                 return;
549
550         task->tk_action = call_start;
551 }
552
553 /*
554  * 0.  Initial state
555  *
556  *     Other FSM states can be visited zero or more times, but
557  *     this state is visited exactly once for each RPC.
558  */
559 static void
560 call_start(struct rpc_task *task)
561 {
562         struct rpc_clnt *clnt = task->tk_client;
563
564         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
565                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
566                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
567
568         /* Increment call count */
569         task->tk_msg.rpc_proc->p_count++;
570         clnt->cl_stats->rpccnt++;
571         task->tk_action = call_reserve;
572 }
573
574 /*
575  * 1.   Reserve an RPC call slot
576  */
577 static void
578 call_reserve(struct rpc_task *task)
579 {
580         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
581
582         if (!rpcauth_uptodatecred(task)) {
583                 task->tk_action = call_refresh;
584                 return;
585         }
586
587         task->tk_status  = 0;
588         task->tk_action  = call_reserveresult;
589         xprt_reserve(task);
590 }
591
592 /*
593  * 1b.  Grok the result of xprt_reserve()
594  */
595 static void
596 call_reserveresult(struct rpc_task *task)
597 {
598         int status = task->tk_status;
599
600         dprintk("RPC: %4d call_reserveresult (status %d)\n",
601                                 task->tk_pid, task->tk_status);
602
603         /*
604          * After a call to xprt_reserve(), we must have either
605          * a request slot or else an error status.
606          */
607         task->tk_status = 0;
608         if (status >= 0) {
609                 if (task->tk_rqstp) {
610                         task->tk_action = call_allocate;
611                         return;
612                 }
613
614                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
615                                 __FUNCTION__, status);
616                 rpc_exit(task, -EIO);
617                 return;
618         }
619
620         /*
621          * Even though there was an error, we may have acquired
622          * a request slot somehow.  Make sure not to leak it.
623          */
624         if (task->tk_rqstp) {
625                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
626                                 __FUNCTION__, status);
627                 xprt_release(task);
628         }
629
630         switch (status) {
631         case -EAGAIN:   /* woken up; retry */
632                 task->tk_action = call_reserve;
633                 return;
634         case -EIO:      /* probably a shutdown */
635                 break;
636         default:
637                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
638                                 __FUNCTION__, status);
639                 break;
640         }
641         rpc_exit(task, status);
642 }
643
644 /*
645  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
646  *      (Note: buffer memory is freed in rpc_task_release).
647  */
648 static void
649 call_allocate(struct rpc_task *task)
650 {
651         unsigned int    bufsiz;
652
653         dprintk("RPC: %4d call_allocate (status %d)\n", 
654                                 task->tk_pid, task->tk_status);
655         task->tk_action = call_bind;
656         if (task->tk_buffer)
657                 return;
658
659         /* FIXME: compute buffer requirements more exactly using
660          * auth->au_wslack */
661         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
662
663         if (rpc_malloc(task, bufsiz << 1) != NULL)
664                 return;
665         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task); 
666
667         if (RPC_IS_ASYNC(task) || !signalled()) {
668                 xprt_release(task);
669                 task->tk_action = call_reserve;
670                 rpc_delay(task, HZ>>4);
671                 return;
672         }
673
674         rpc_exit(task, -ERESTARTSYS);
675 }
676
677 static inline int
678 rpc_task_need_encode(struct rpc_task *task)
679 {
680         return task->tk_rqstp->rq_snd_buf.len == 0;
681 }
682
683 static inline void
684 rpc_task_force_reencode(struct rpc_task *task)
685 {
686         task->tk_rqstp->rq_snd_buf.len = 0;
687 }
688
689 /*
690  * 3.   Encode arguments of an RPC call
691  */
692 static void
693 call_encode(struct rpc_task *task)
694 {
695         struct rpc_rqst *req = task->tk_rqstp;
696         struct xdr_buf *sndbuf = &req->rq_snd_buf;
697         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
698         unsigned int    bufsiz;
699         kxdrproc_t      encode;
700         u32             *p;
701
702         dprintk("RPC: %4d call_encode (status %d)\n", 
703                                 task->tk_pid, task->tk_status);
704
705         /* Default buffer setup */
706         bufsiz = task->tk_bufsize >> 1;
707         sndbuf->head[0].iov_base = (void *)task->tk_buffer;
708         sndbuf->head[0].iov_len  = bufsiz;
709         sndbuf->tail[0].iov_len  = 0;
710         sndbuf->page_len         = 0;
711         sndbuf->len              = 0;
712         sndbuf->buflen           = bufsiz;
713         rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
714         rcvbuf->head[0].iov_len  = bufsiz;
715         rcvbuf->tail[0].iov_len  = 0;
716         rcvbuf->page_len         = 0;
717         rcvbuf->len              = 0;
718         rcvbuf->buflen           = bufsiz;
719
720         /* Encode header and provided arguments */
721         encode = task->tk_msg.rpc_proc->p_encode;
722         if (!(p = call_header(task))) {
723                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
724                 rpc_exit(task, -EIO);
725                 return;
726         }
727         if (encode == NULL)
728                 return;
729
730         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
731                         task->tk_msg.rpc_argp);
732         if (task->tk_status == -ENOMEM) {
733                 /* XXX: Is this sane? */
734                 rpc_delay(task, 3*HZ);
735                 task->tk_status = -EAGAIN;
736         }
737 }
738
739 /*
740  * 4.   Get the server port number if not yet set
741  */
742 static void
743 call_bind(struct rpc_task *task)
744 {
745         struct rpc_clnt *clnt = task->tk_client;
746
747         dprintk("RPC: %4d call_bind (status %d)\n",
748                                 task->tk_pid, task->tk_status);
749
750         task->tk_action = call_connect;
751         if (!clnt->cl_port) {
752                 task->tk_action = call_bind_status;
753                 task->tk_timeout = task->tk_xprt->bind_timeout;
754                 rpc_getport(task, clnt);
755         }
756 }
757
758 /*
759  * 4a.  Sort out bind result
760  */
761 static void
762 call_bind_status(struct rpc_task *task)
763 {
764         int status = -EACCES;
765
766         if (task->tk_status >= 0) {
767                 dprintk("RPC: %4d call_bind_status (status %d)\n",
768                                         task->tk_pid, task->tk_status);
769                 task->tk_status = 0;
770                 task->tk_action = call_connect;
771                 return;
772         }
773
774         switch (task->tk_status) {
775         case -EACCES:
776                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
777                                 task->tk_pid);
778                 rpc_delay(task, 3*HZ);
779                 goto retry_bind;
780         case -ETIMEDOUT:
781                 dprintk("RPC: %4d rpcbind request timed out\n",
782                                 task->tk_pid);
783                 if (RPC_IS_SOFT(task)) {
784                         status = -EIO;
785                         break;
786                 }
787                 goto retry_bind;
788         case -EPFNOSUPPORT:
789                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
790                                 task->tk_pid);
791                 break;
792         case -EPROTONOSUPPORT:
793                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
794                                 task->tk_pid);
795                 break;
796         default:
797                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
798                                 task->tk_pid, -task->tk_status);
799                 status = -EIO;
800                 break;
801         }
802
803         rpc_exit(task, status);
804         return;
805
806 retry_bind:
807         task->tk_status = 0;
808         task->tk_action = call_bind;
809         return;
810 }
811
812 /*
813  * 4b.  Connect to the RPC server
814  */
815 static void
816 call_connect(struct rpc_task *task)
817 {
818         struct rpc_xprt *xprt = task->tk_xprt;
819
820         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
821                         task->tk_pid, xprt,
822                         (xprt_connected(xprt) ? "is" : "is not"));
823
824         task->tk_action = call_transmit;
825         if (!xprt_connected(xprt)) {
826                 task->tk_action = call_connect_status;
827                 if (task->tk_status < 0)
828                         return;
829                 xprt_connect(task);
830         }
831 }
832
833 /*
834  * 4c.  Sort out connect result
835  */
836 static void
837 call_connect_status(struct rpc_task *task)
838 {
839         struct rpc_clnt *clnt = task->tk_client;
840         int status = task->tk_status;
841
842         dprintk("RPC: %5u call_connect_status (status %d)\n", 
843                                 task->tk_pid, task->tk_status);
844
845         task->tk_status = 0;
846         if (status >= 0) {
847                 clnt->cl_stats->netreconn++;
848                 task->tk_action = call_transmit;
849                 return;
850         }
851
852         /* Something failed: remote service port may have changed */
853         if (clnt->cl_autobind)
854                 clnt->cl_port = 0;
855
856         switch (status) {
857         case -ENOTCONN:
858         case -ETIMEDOUT:
859         case -EAGAIN:
860                 task->tk_action = call_bind;
861                 break;
862         default:
863                 rpc_exit(task, -EIO);
864                 break;
865         }
866 }
867
868 /*
869  * 5.   Transmit the RPC request, and wait for reply
870  */
871 static void
872 call_transmit(struct rpc_task *task)
873 {
874         dprintk("RPC: %4d call_transmit (status %d)\n", 
875                                 task->tk_pid, task->tk_status);
876
877         task->tk_action = call_status;
878         if (task->tk_status < 0)
879                 return;
880         task->tk_status = xprt_prepare_transmit(task);
881         if (task->tk_status != 0)
882                 return;
883         /* Encode here so that rpcsec_gss can use correct sequence number. */
884         if (rpc_task_need_encode(task)) {
885                 task->tk_rqstp->rq_bytes_sent = 0;
886                 call_encode(task);
887                 /* Did the encode result in an error condition? */
888                 if (task->tk_status != 0)
889                         goto out_nosend;
890         }
891         task->tk_action = call_transmit_status;
892         xprt_transmit(task);
893         if (task->tk_status < 0)
894                 return;
895         if (!task->tk_msg.rpc_proc->p_decode) {
896                 task->tk_action = rpc_exit_task;
897                 rpc_wake_up_task(task);
898         }
899         return;
900 out_nosend:
901         /* release socket write lock before attempting to handle error */
902         xprt_abort_transmit(task);
903         rpc_task_force_reencode(task);
904 }
905
906 /*
907  * 6.   Sort out the RPC call status
908  */
909 static void
910 call_status(struct rpc_task *task)
911 {
912         struct rpc_clnt *clnt = task->tk_client;
913         struct rpc_rqst *req = task->tk_rqstp;
914         int             status;
915
916         if (req->rq_received > 0 && !req->rq_bytes_sent)
917                 task->tk_status = req->rq_received;
918
919         dprintk("RPC: %4d call_status (status %d)\n", 
920                                 task->tk_pid, task->tk_status);
921
922         status = task->tk_status;
923         if (status >= 0) {
924                 task->tk_action = call_decode;
925                 return;
926         }
927
928         task->tk_status = 0;
929         switch(status) {
930         case -ETIMEDOUT:
931                 task->tk_action = call_timeout;
932                 break;
933         case -ECONNREFUSED:
934         case -ENOTCONN:
935                 if (clnt->cl_autobind)
936                         clnt->cl_port = 0;
937                 task->tk_action = call_bind;
938                 break;
939         case -EAGAIN:
940                 task->tk_action = call_transmit;
941                 break;
942         case -EIO:
943                 /* shutdown or soft timeout */
944                 rpc_exit(task, status);
945                 break;
946         default:
947                 if (clnt->cl_chatty)
948                         printk("%s: RPC call returned error %d\n",
949                                clnt->cl_protname, -status);
950                 rpc_exit(task, status);
951                 break;
952         }
953 }
954
955 /*
956  * 6a.  Handle transmission errors.
957  */
958 static void
959 call_transmit_status(struct rpc_task *task)
960 {
961         if (task->tk_status != -EAGAIN)
962                 rpc_task_force_reencode(task);
963         call_status(task);
964 }
965
966 /*
967  * 6b.  Handle RPC timeout
968  *      We do not release the request slot, so we keep using the
969  *      same XID for all retransmits.
970  */
971 static void
972 call_timeout(struct rpc_task *task)
973 {
974         struct rpc_clnt *clnt = task->tk_client;
975
976         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
977                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
978                 goto retry;
979         }
980
981         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
982         if (RPC_IS_SOFT(task)) {
983                 if (clnt->cl_chatty)
984                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
985                                 clnt->cl_protname, clnt->cl_server);
986                 rpc_exit(task, -EIO);
987                 return;
988         }
989
990         if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
991                 task->tk_flags |= RPC_CALL_MAJORSEEN;
992                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
993                         clnt->cl_protname, clnt->cl_server);
994         }
995         if (clnt->cl_autobind)
996                 clnt->cl_port = 0;
997
998 retry:
999         clnt->cl_stats->rpcretrans++;
1000         task->tk_action = call_bind;
1001         task->tk_status = 0;
1002 }
1003
1004 /*
1005  * 7.   Decode the RPC reply
1006  */
1007 static void
1008 call_decode(struct rpc_task *task)
1009 {
1010         struct rpc_clnt *clnt = task->tk_client;
1011         struct rpc_rqst *req = task->tk_rqstp;
1012         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1013         u32             *p;
1014
1015         dprintk("RPC: %4d call_decode (status %d)\n", 
1016                                 task->tk_pid, task->tk_status);
1017
1018         if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) {
1019                 printk(KERN_NOTICE "%s: server %s OK\n",
1020                         clnt->cl_protname, clnt->cl_server);
1021                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1022         }
1023
1024         if (task->tk_status < 12) {
1025                 if (!RPC_IS_SOFT(task)) {
1026                         task->tk_action = call_bind;
1027                         clnt->cl_stats->rpcretrans++;
1028                         goto out_retry;
1029                 }
1030                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1031                         clnt->cl_protname, task->tk_status);
1032                 rpc_exit(task, -EIO);
1033                 return;
1034         }
1035
1036         req->rq_rcv_buf.len = req->rq_private_buf.len;
1037
1038         /* Check that the softirq receive buffer is valid */
1039         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1040                                 sizeof(req->rq_rcv_buf)) != 0);
1041
1042         /* Verify the RPC header */
1043         p = call_verify(task);
1044         if (IS_ERR(p)) {
1045                 if (p == ERR_PTR(-EAGAIN))
1046                         goto out_retry;
1047                 return;
1048         }
1049
1050         task->tk_action = rpc_exit_task;
1051
1052         if (decode)
1053                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1054                                                       task->tk_msg.rpc_resp);
1055         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1056                                         task->tk_status);
1057         return;
1058 out_retry:
1059         req->rq_received = req->rq_private_buf.len = 0;
1060         task->tk_status = 0;
1061 }
1062
1063 /*
1064  * 8.   Refresh the credentials if rejected by the server
1065  */
1066 static void
1067 call_refresh(struct rpc_task *task)
1068 {
1069         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1070
1071         xprt_release(task);     /* Must do to obtain new XID */
1072         task->tk_action = call_refreshresult;
1073         task->tk_status = 0;
1074         task->tk_client->cl_stats->rpcauthrefresh++;
1075         rpcauth_refreshcred(task);
1076 }
1077
1078 /*
1079  * 8a.  Process the results of a credential refresh
1080  */
1081 static void
1082 call_refreshresult(struct rpc_task *task)
1083 {
1084         int status = task->tk_status;
1085         dprintk("RPC: %4d call_refreshresult (status %d)\n", 
1086                                 task->tk_pid, task->tk_status);
1087
1088         task->tk_status = 0;
1089         task->tk_action = call_reserve;
1090         if (status >= 0 && rpcauth_uptodatecred(task))
1091                 return;
1092         if (status == -EACCES) {
1093                 rpc_exit(task, -EACCES);
1094                 return;
1095         }
1096         task->tk_action = call_refresh;
1097         if (status != -ETIMEDOUT)
1098                 rpc_delay(task, 3*HZ);
1099         return;
1100 }
1101
1102 /*
1103  * Call header serialization
1104  */
1105 static u32 *
1106 call_header(struct rpc_task *task)
1107 {
1108         struct rpc_clnt *clnt = task->tk_client;
1109         struct rpc_rqst *req = task->tk_rqstp;
1110         u32             *p = req->rq_svec[0].iov_base;
1111
1112         /* FIXME: check buffer size? */
1113
1114         p = xprt_skip_transport_header(task->tk_xprt, p);
1115         *p++ = req->rq_xid;             /* XID */
1116         *p++ = htonl(RPC_CALL);         /* CALL */
1117         *p++ = htonl(RPC_VERSION);      /* RPC version */
1118         *p++ = htonl(clnt->cl_prog);    /* program number */
1119         *p++ = htonl(clnt->cl_vers);    /* program version */
1120         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1121         p = rpcauth_marshcred(task, p);
1122         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1123         return p;
1124 }
1125
1126 /*
1127  * Reply header verification
1128  */
1129 static u32 *
1130 call_verify(struct rpc_task *task)
1131 {
1132         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1133         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1134         u32     *p = iov->iov_base, n;
1135         int error = -EACCES;
1136
1137         if ((len -= 3) < 0)
1138                 goto out_overflow;
1139         p += 1; /* skip XID */
1140
1141         if ((n = ntohl(*p++)) != RPC_REPLY) {
1142                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1143                 goto out_garbage;
1144         }
1145         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1146                 if (--len < 0)
1147                         goto out_overflow;
1148                 switch ((n = ntohl(*p++))) {
1149                         case RPC_AUTH_ERROR:
1150                                 break;
1151                         case RPC_MISMATCH:
1152                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1153                                 error = -EPROTONOSUPPORT;
1154                                 goto out_err;
1155                         default:
1156                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1157                                 goto out_eio;
1158                 }
1159                 if (--len < 0)
1160                         goto out_overflow;
1161                 switch ((n = ntohl(*p++))) {
1162                 case RPC_AUTH_REJECTEDCRED:
1163                 case RPC_AUTH_REJECTEDVERF:
1164                 case RPCSEC_GSS_CREDPROBLEM:
1165                 case RPCSEC_GSS_CTXPROBLEM:
1166                         if (!task->tk_cred_retry)
1167                                 break;
1168                         task->tk_cred_retry--;
1169                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1170                                                         task->tk_pid);
1171                         rpcauth_invalcred(task);
1172                         task->tk_action = call_refresh;
1173                         goto out_retry;
1174                 case RPC_AUTH_BADCRED:
1175                 case RPC_AUTH_BADVERF:
1176                         /* possibly garbled cred/verf? */
1177                         if (!task->tk_garb_retry)
1178                                 break;
1179                         task->tk_garb_retry--;
1180                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1181                                                         task->tk_pid);
1182                         task->tk_action = call_bind;
1183                         goto out_retry;
1184                 case RPC_AUTH_TOOWEAK:
1185                         printk(KERN_NOTICE "call_verify: server requires stronger "
1186                                "authentication.\n");
1187                         break;
1188                 default:
1189                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1190                         error = -EIO;
1191                 }
1192                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1193                                                 task->tk_pid, n);
1194                 goto out_err;
1195         }
1196         if (!(p = rpcauth_checkverf(task, p))) {
1197                 printk(KERN_WARNING "call_verify: auth check failed\n");
1198                 goto out_garbage;               /* bad verifier, retry */
1199         }
1200         len = p - (u32 *)iov->iov_base - 1;
1201         if (len < 0)
1202                 goto out_overflow;
1203         switch ((n = ntohl(*p++))) {
1204         case RPC_SUCCESS:
1205                 return p;
1206         case RPC_PROG_UNAVAIL:
1207                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1208                                 (unsigned int)task->tk_client->cl_prog,
1209                                 task->tk_client->cl_server);
1210                 error = -EPFNOSUPPORT;
1211                 goto out_err;
1212         case RPC_PROG_MISMATCH:
1213                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1214                                 (unsigned int)task->tk_client->cl_prog,
1215                                 (unsigned int)task->tk_client->cl_vers,
1216                                 task->tk_client->cl_server);
1217                 error = -EPROTONOSUPPORT;
1218                 goto out_err;
1219         case RPC_PROC_UNAVAIL:
1220                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1221                                 task->tk_msg.rpc_proc,
1222                                 task->tk_client->cl_prog,
1223                                 task->tk_client->cl_vers,
1224                                 task->tk_client->cl_server);
1225                 error = -EOPNOTSUPP;
1226                 goto out_err;
1227         case RPC_GARBAGE_ARGS:
1228                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1229                 break;                  /* retry */
1230         default:
1231                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1232                 /* Also retry */
1233         }
1234
1235 out_garbage:
1236         task->tk_client->cl_stats->rpcgarbage++;
1237         if (task->tk_garb_retry) {
1238                 task->tk_garb_retry--;
1239                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1240                 task->tk_action = call_bind;
1241 out_retry:
1242                 return ERR_PTR(-EAGAIN);
1243         }
1244         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1245 out_eio:
1246         error = -EIO;
1247 out_err:
1248         rpc_exit(task, error);
1249         return ERR_PTR(error);
1250 out_overflow:
1251         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1252         goto out_garbage;
1253 }
1254
1255 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1256 {
1257         return 0;
1258 }
1259
1260 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1261 {
1262         return 0;
1263 }
1264
1265 static struct rpc_procinfo rpcproc_null = {
1266         .p_encode = rpcproc_encode_null,
1267         .p_decode = rpcproc_decode_null,
1268 };
1269
1270 int rpc_ping(struct rpc_clnt *clnt, int flags)
1271 {
1272         struct rpc_message msg = {
1273                 .rpc_proc = &rpcproc_null,
1274         };
1275         int err;
1276         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1277         err = rpc_call_sync(clnt, &msg, flags);
1278         put_rpccred(msg.rpc_cred);
1279         return err;
1280 }