6ab4cbd8a9015937396ad1fd41103ef4b196cba4
[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)
378 {
379 }
380
381 /*
382  *      Export the signal mask handling for synchronous code that
383  *      sleeps on RPC calls
384  */
385 #define RPC_INTR_SIGNALS (sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGKILL))
386  
387 static void rpc_save_sigmask(sigset_t *oldset, int intr)
388 {
389         unsigned long   sigallow = 0;
390         sigset_t sigmask;
391
392         /* Block all signals except those listed in sigallow */
393         if (intr)
394                 sigallow |= RPC_INTR_SIGNALS;
395         siginitsetinv(&sigmask, sigallow);
396         sigprocmask(SIG_BLOCK, &sigmask, oldset);
397 }
398
399 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
400 {
401         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
402 }
403
404 static inline void rpc_restore_sigmask(sigset_t *oldset)
405 {
406         sigprocmask(SIG_SETMASK, oldset, NULL);
407 }
408
409 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
410 {
411         rpc_save_sigmask(oldset, clnt->cl_intr);
412 }
413
414 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
415 {
416         rpc_restore_sigmask(oldset);
417 }
418
419 /*
420  * New rpc_call implementation
421  */
422 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
423 {
424         struct rpc_task *task;
425         sigset_t        oldset;
426         int             status;
427
428         /* If this client is slain all further I/O fails */
429         if (clnt->cl_dead) 
430                 return -EIO;
431
432         BUG_ON(flags & RPC_TASK_ASYNC);
433
434         status = -ENOMEM;
435         task = rpc_new_task(clnt, NULL, flags);
436         if (task == NULL)
437                 goto out;
438
439         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
440         rpc_task_sigmask(task, &oldset);
441
442         rpc_call_setup(task, msg, 0);
443
444         /* Set up the call info struct and execute the task */
445         if (task->tk_status == 0) {
446                 status = rpc_execute(task);
447         } else {
448                 status = task->tk_status;
449                 rpc_release_task(task);
450         }
451
452         rpc_restore_sigmask(&oldset);
453 out:
454         return status;
455 }
456
457 /*
458  * New rpc_call implementation
459  */
460 int
461 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
462                rpc_action callback, void *data)
463 {
464         struct rpc_task *task;
465         sigset_t        oldset;
466         int             status;
467
468         /* If this client is slain all further I/O fails */
469         if (clnt->cl_dead) 
470                 return -EIO;
471
472         flags |= RPC_TASK_ASYNC;
473
474         /* Create/initialize a new RPC task */
475         if (!callback)
476                 callback = rpc_default_callback;
477         status = -ENOMEM;
478         if (!(task = rpc_new_task(clnt, callback, flags)))
479                 goto out;
480         task->tk_calldata = data;
481
482         /* Mask signals on GSS_AUTH upcalls */
483         rpc_task_sigmask(task, &oldset);                
484
485         rpc_call_setup(task, msg, 0);
486
487         /* Set up the call info struct and execute the task */
488         status = task->tk_status;
489         if (status == 0)
490                 rpc_execute(task);
491         else
492                 rpc_release_task(task);
493
494         rpc_restore_sigmask(&oldset);           
495 out:
496         return status;
497 }
498
499
500 void
501 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
502 {
503         task->tk_msg   = *msg;
504         task->tk_flags |= flags;
505         /* Bind the user cred */
506         if (task->tk_msg.rpc_cred != NULL)
507                 rpcauth_holdcred(task);
508         else
509                 rpcauth_bindcred(task);
510
511         if (task->tk_status == 0)
512                 task->tk_action = call_start;
513         else
514                 task->tk_action = rpc_exit_task;
515 }
516
517 void
518 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
519 {
520         struct rpc_xprt *xprt = clnt->cl_xprt;
521         if (xprt->ops->set_buffer_size)
522                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
523 }
524
525 /*
526  * Return size of largest payload RPC client can support, in bytes
527  *
528  * For stream transports, this is one RPC record fragment (see RFC
529  * 1831), as we don't support multi-record requests yet.  For datagram
530  * transports, this is the size of an IP packet minus the IP, UDP, and
531  * RPC header sizes.
532  */
533 size_t rpc_max_payload(struct rpc_clnt *clnt)
534 {
535         return clnt->cl_xprt->max_payload;
536 }
537 EXPORT_SYMBOL(rpc_max_payload);
538
539 /*
540  * Restart an (async) RPC call. Usually called from within the
541  * exit handler.
542  */
543 void
544 rpc_restart_call(struct rpc_task *task)
545 {
546         if (RPC_ASSASSINATED(task))
547                 return;
548
549         task->tk_action = call_start;
550 }
551
552 /*
553  * 0.  Initial state
554  *
555  *     Other FSM states can be visited zero or more times, but
556  *     this state is visited exactly once for each RPC.
557  */
558 static void
559 call_start(struct rpc_task *task)
560 {
561         struct rpc_clnt *clnt = task->tk_client;
562
563         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
564                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
565                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
566
567         /* Increment call count */
568         task->tk_msg.rpc_proc->p_count++;
569         clnt->cl_stats->rpccnt++;
570         task->tk_action = call_reserve;
571 }
572
573 /*
574  * 1.   Reserve an RPC call slot
575  */
576 static void
577 call_reserve(struct rpc_task *task)
578 {
579         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
580
581         if (!rpcauth_uptodatecred(task)) {
582                 task->tk_action = call_refresh;
583                 return;
584         }
585
586         task->tk_status  = 0;
587         task->tk_action  = call_reserveresult;
588         xprt_reserve(task);
589 }
590
591 /*
592  * 1b.  Grok the result of xprt_reserve()
593  */
594 static void
595 call_reserveresult(struct rpc_task *task)
596 {
597         int status = task->tk_status;
598
599         dprintk("RPC: %4d call_reserveresult (status %d)\n",
600                                 task->tk_pid, task->tk_status);
601
602         /*
603          * After a call to xprt_reserve(), we must have either
604          * a request slot or else an error status.
605          */
606         task->tk_status = 0;
607         if (status >= 0) {
608                 if (task->tk_rqstp) {
609                         task->tk_action = call_allocate;
610                         return;
611                 }
612
613                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
614                                 __FUNCTION__, status);
615                 rpc_exit(task, -EIO);
616                 return;
617         }
618
619         /*
620          * Even though there was an error, we may have acquired
621          * a request slot somehow.  Make sure not to leak it.
622          */
623         if (task->tk_rqstp) {
624                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
625                                 __FUNCTION__, status);
626                 xprt_release(task);
627         }
628
629         switch (status) {
630         case -EAGAIN:   /* woken up; retry */
631                 task->tk_action = call_reserve;
632                 return;
633         case -EIO:      /* probably a shutdown */
634                 break;
635         default:
636                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
637                                 __FUNCTION__, status);
638                 break;
639         }
640         rpc_exit(task, status);
641 }
642
643 /*
644  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
645  *      (Note: buffer memory is freed in rpc_task_release).
646  */
647 static void
648 call_allocate(struct rpc_task *task)
649 {
650         unsigned int    bufsiz;
651
652         dprintk("RPC: %4d call_allocate (status %d)\n", 
653                                 task->tk_pid, task->tk_status);
654         task->tk_action = call_bind;
655         if (task->tk_buffer)
656                 return;
657
658         /* FIXME: compute buffer requirements more exactly using
659          * auth->au_wslack */
660         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
661
662         if (rpc_malloc(task, bufsiz << 1) != NULL)
663                 return;
664         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task); 
665
666         if (RPC_IS_ASYNC(task) || !signalled()) {
667                 xprt_release(task);
668                 task->tk_action = call_reserve;
669                 rpc_delay(task, HZ>>4);
670                 return;
671         }
672
673         rpc_exit(task, -ERESTARTSYS);
674 }
675
676 static inline int
677 rpc_task_need_encode(struct rpc_task *task)
678 {
679         return task->tk_rqstp->rq_snd_buf.len == 0;
680 }
681
682 static inline void
683 rpc_task_force_reencode(struct rpc_task *task)
684 {
685         task->tk_rqstp->rq_snd_buf.len = 0;
686 }
687
688 /*
689  * 3.   Encode arguments of an RPC call
690  */
691 static void
692 call_encode(struct rpc_task *task)
693 {
694         struct rpc_rqst *req = task->tk_rqstp;
695         struct xdr_buf *sndbuf = &req->rq_snd_buf;
696         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
697         unsigned int    bufsiz;
698         kxdrproc_t      encode;
699         u32             *p;
700
701         dprintk("RPC: %4d call_encode (status %d)\n", 
702                                 task->tk_pid, task->tk_status);
703
704         /* Default buffer setup */
705         bufsiz = task->tk_bufsize >> 1;
706         sndbuf->head[0].iov_base = (void *)task->tk_buffer;
707         sndbuf->head[0].iov_len  = bufsiz;
708         sndbuf->tail[0].iov_len  = 0;
709         sndbuf->page_len         = 0;
710         sndbuf->len              = 0;
711         sndbuf->buflen           = bufsiz;
712         rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
713         rcvbuf->head[0].iov_len  = bufsiz;
714         rcvbuf->tail[0].iov_len  = 0;
715         rcvbuf->page_len         = 0;
716         rcvbuf->len              = 0;
717         rcvbuf->buflen           = bufsiz;
718
719         /* Encode header and provided arguments */
720         encode = task->tk_msg.rpc_proc->p_encode;
721         if (!(p = call_header(task))) {
722                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
723                 rpc_exit(task, -EIO);
724                 return;
725         }
726         if (encode == NULL)
727                 return;
728
729         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
730                         task->tk_msg.rpc_argp);
731         if (task->tk_status == -ENOMEM) {
732                 /* XXX: Is this sane? */
733                 rpc_delay(task, 3*HZ);
734                 task->tk_status = -EAGAIN;
735         }
736 }
737
738 /*
739  * 4.   Get the server port number if not yet set
740  */
741 static void
742 call_bind(struct rpc_task *task)
743 {
744         struct rpc_clnt *clnt = task->tk_client;
745
746         dprintk("RPC: %4d call_bind (status %d)\n",
747                                 task->tk_pid, task->tk_status);
748
749         task->tk_action = call_connect;
750         if (!clnt->cl_port) {
751                 task->tk_action = call_bind_status;
752                 task->tk_timeout = task->tk_xprt->bind_timeout;
753                 rpc_getport(task, clnt);
754         }
755 }
756
757 /*
758  * 4a.  Sort out bind result
759  */
760 static void
761 call_bind_status(struct rpc_task *task)
762 {
763         int status = -EACCES;
764
765         if (task->tk_status >= 0) {
766                 dprintk("RPC: %4d call_bind_status (status %d)\n",
767                                         task->tk_pid, task->tk_status);
768                 task->tk_status = 0;
769                 task->tk_action = call_connect;
770                 return;
771         }
772
773         switch (task->tk_status) {
774         case -EACCES:
775                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
776                                 task->tk_pid);
777                 rpc_delay(task, 3*HZ);
778                 goto retry_bind;
779         case -ETIMEDOUT:
780                 dprintk("RPC: %4d rpcbind request timed out\n",
781                                 task->tk_pid);
782                 if (RPC_IS_SOFT(task)) {
783                         status = -EIO;
784                         break;
785                 }
786                 goto retry_bind;
787         case -EPFNOSUPPORT:
788                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
789                                 task->tk_pid);
790                 break;
791         case -EPROTONOSUPPORT:
792                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
793                                 task->tk_pid);
794                 break;
795         default:
796                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
797                                 task->tk_pid, -task->tk_status);
798                 status = -EIO;
799                 break;
800         }
801
802         rpc_exit(task, status);
803         return;
804
805 retry_bind:
806         task->tk_status = 0;
807         task->tk_action = call_bind;
808         return;
809 }
810
811 /*
812  * 4b.  Connect to the RPC server
813  */
814 static void
815 call_connect(struct rpc_task *task)
816 {
817         struct rpc_xprt *xprt = task->tk_xprt;
818
819         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
820                         task->tk_pid, xprt,
821                         (xprt_connected(xprt) ? "is" : "is not"));
822
823         task->tk_action = call_transmit;
824         if (!xprt_connected(xprt)) {
825                 task->tk_action = call_connect_status;
826                 if (task->tk_status < 0)
827                         return;
828                 xprt_connect(task);
829         }
830 }
831
832 /*
833  * 4c.  Sort out connect result
834  */
835 static void
836 call_connect_status(struct rpc_task *task)
837 {
838         struct rpc_clnt *clnt = task->tk_client;
839         int status = task->tk_status;
840
841         dprintk("RPC: %5u call_connect_status (status %d)\n", 
842                                 task->tk_pid, task->tk_status);
843
844         task->tk_status = 0;
845         if (status >= 0) {
846                 clnt->cl_stats->netreconn++;
847                 task->tk_action = call_transmit;
848                 return;
849         }
850
851         /* Something failed: remote service port may have changed */
852         if (clnt->cl_autobind)
853                 clnt->cl_port = 0;
854
855         switch (status) {
856         case -ENOTCONN:
857         case -ETIMEDOUT:
858         case -EAGAIN:
859                 task->tk_action = call_bind;
860                 break;
861         default:
862                 rpc_exit(task, -EIO);
863                 break;
864         }
865 }
866
867 /*
868  * 5.   Transmit the RPC request, and wait for reply
869  */
870 static void
871 call_transmit(struct rpc_task *task)
872 {
873         dprintk("RPC: %4d call_transmit (status %d)\n", 
874                                 task->tk_pid, task->tk_status);
875
876         task->tk_action = call_status;
877         if (task->tk_status < 0)
878                 return;
879         task->tk_status = xprt_prepare_transmit(task);
880         if (task->tk_status != 0)
881                 return;
882         /* Encode here so that rpcsec_gss can use correct sequence number. */
883         if (rpc_task_need_encode(task)) {
884                 task->tk_rqstp->rq_bytes_sent = 0;
885                 call_encode(task);
886                 /* Did the encode result in an error condition? */
887                 if (task->tk_status != 0)
888                         goto out_nosend;
889         }
890         task->tk_action = call_transmit_status;
891         xprt_transmit(task);
892         if (task->tk_status < 0)
893                 return;
894         if (!task->tk_msg.rpc_proc->p_decode) {
895                 task->tk_action = rpc_exit_task;
896                 rpc_wake_up_task(task);
897         }
898         return;
899 out_nosend:
900         /* release socket write lock before attempting to handle error */
901         xprt_abort_transmit(task);
902         rpc_task_force_reencode(task);
903 }
904
905 /*
906  * 6.   Sort out the RPC call status
907  */
908 static void
909 call_status(struct rpc_task *task)
910 {
911         struct rpc_clnt *clnt = task->tk_client;
912         struct rpc_rqst *req = task->tk_rqstp;
913         int             status;
914
915         if (req->rq_received > 0 && !req->rq_bytes_sent)
916                 task->tk_status = req->rq_received;
917
918         dprintk("RPC: %4d call_status (status %d)\n", 
919                                 task->tk_pid, task->tk_status);
920
921         status = task->tk_status;
922         if (status >= 0) {
923                 task->tk_action = call_decode;
924                 return;
925         }
926
927         task->tk_status = 0;
928         switch(status) {
929         case -ETIMEDOUT:
930                 task->tk_action = call_timeout;
931                 break;
932         case -ECONNREFUSED:
933         case -ENOTCONN:
934                 if (clnt->cl_autobind)
935                         clnt->cl_port = 0;
936                 task->tk_action = call_bind;
937                 break;
938         case -EAGAIN:
939                 task->tk_action = call_transmit;
940                 break;
941         case -EIO:
942                 /* shutdown or soft timeout */
943                 rpc_exit(task, status);
944                 break;
945         default:
946                 if (clnt->cl_chatty)
947                         printk("%s: RPC call returned error %d\n",
948                                clnt->cl_protname, -status);
949                 rpc_exit(task, status);
950                 break;
951         }
952 }
953
954 /*
955  * 6a.  Handle transmission errors.
956  */
957 static void
958 call_transmit_status(struct rpc_task *task)
959 {
960         if (task->tk_status != -EAGAIN)
961                 rpc_task_force_reencode(task);
962         call_status(task);
963 }
964
965 /*
966  * 6b.  Handle RPC timeout
967  *      We do not release the request slot, so we keep using the
968  *      same XID for all retransmits.
969  */
970 static void
971 call_timeout(struct rpc_task *task)
972 {
973         struct rpc_clnt *clnt = task->tk_client;
974
975         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
976                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
977                 goto retry;
978         }
979
980         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
981         if (RPC_IS_SOFT(task)) {
982                 if (clnt->cl_chatty)
983                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
984                                 clnt->cl_protname, clnt->cl_server);
985                 rpc_exit(task, -EIO);
986                 return;
987         }
988
989         if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) {
990                 task->tk_flags |= RPC_CALL_MAJORSEEN;
991                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
992                         clnt->cl_protname, clnt->cl_server);
993         }
994         if (clnt->cl_autobind)
995                 clnt->cl_port = 0;
996
997 retry:
998         clnt->cl_stats->rpcretrans++;
999         task->tk_action = call_bind;
1000         task->tk_status = 0;
1001 }
1002
1003 /*
1004  * 7.   Decode the RPC reply
1005  */
1006 static void
1007 call_decode(struct rpc_task *task)
1008 {
1009         struct rpc_clnt *clnt = task->tk_client;
1010         struct rpc_rqst *req = task->tk_rqstp;
1011         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1012         u32             *p;
1013
1014         dprintk("RPC: %4d call_decode (status %d)\n", 
1015                                 task->tk_pid, task->tk_status);
1016
1017         if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) {
1018                 printk(KERN_NOTICE "%s: server %s OK\n",
1019                         clnt->cl_protname, clnt->cl_server);
1020                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1021         }
1022
1023         if (task->tk_status < 12) {
1024                 if (!RPC_IS_SOFT(task)) {
1025                         task->tk_action = call_bind;
1026                         clnt->cl_stats->rpcretrans++;
1027                         goto out_retry;
1028                 }
1029                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1030                         clnt->cl_protname, task->tk_status);
1031                 rpc_exit(task, -EIO);
1032                 return;
1033         }
1034
1035         req->rq_rcv_buf.len = req->rq_private_buf.len;
1036
1037         /* Check that the softirq receive buffer is valid */
1038         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1039                                 sizeof(req->rq_rcv_buf)) != 0);
1040
1041         /* Verify the RPC header */
1042         p = call_verify(task);
1043         if (IS_ERR(p)) {
1044                 if (p == ERR_PTR(-EAGAIN))
1045                         goto out_retry;
1046                 return;
1047         }
1048
1049         task->tk_action = rpc_exit_task;
1050
1051         if (decode)
1052                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1053                                                       task->tk_msg.rpc_resp);
1054         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1055                                         task->tk_status);
1056         return;
1057 out_retry:
1058         req->rq_received = req->rq_private_buf.len = 0;
1059         task->tk_status = 0;
1060 }
1061
1062 /*
1063  * 8.   Refresh the credentials if rejected by the server
1064  */
1065 static void
1066 call_refresh(struct rpc_task *task)
1067 {
1068         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1069
1070         xprt_release(task);     /* Must do to obtain new XID */
1071         task->tk_action = call_refreshresult;
1072         task->tk_status = 0;
1073         task->tk_client->cl_stats->rpcauthrefresh++;
1074         rpcauth_refreshcred(task);
1075 }
1076
1077 /*
1078  * 8a.  Process the results of a credential refresh
1079  */
1080 static void
1081 call_refreshresult(struct rpc_task *task)
1082 {
1083         int status = task->tk_status;
1084         dprintk("RPC: %4d call_refreshresult (status %d)\n", 
1085                                 task->tk_pid, task->tk_status);
1086
1087         task->tk_status = 0;
1088         task->tk_action = call_reserve;
1089         if (status >= 0 && rpcauth_uptodatecred(task))
1090                 return;
1091         if (status == -EACCES) {
1092                 rpc_exit(task, -EACCES);
1093                 return;
1094         }
1095         task->tk_action = call_refresh;
1096         if (status != -ETIMEDOUT)
1097                 rpc_delay(task, 3*HZ);
1098         return;
1099 }
1100
1101 /*
1102  * Call header serialization
1103  */
1104 static u32 *
1105 call_header(struct rpc_task *task)
1106 {
1107         struct rpc_clnt *clnt = task->tk_client;
1108         struct rpc_rqst *req = task->tk_rqstp;
1109         u32             *p = req->rq_svec[0].iov_base;
1110
1111         /* FIXME: check buffer size? */
1112
1113         p = xprt_skip_transport_header(task->tk_xprt, p);
1114         *p++ = req->rq_xid;             /* XID */
1115         *p++ = htonl(RPC_CALL);         /* CALL */
1116         *p++ = htonl(RPC_VERSION);      /* RPC version */
1117         *p++ = htonl(clnt->cl_prog);    /* program number */
1118         *p++ = htonl(clnt->cl_vers);    /* program version */
1119         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1120         p = rpcauth_marshcred(task, p);
1121         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1122         return p;
1123 }
1124
1125 /*
1126  * Reply header verification
1127  */
1128 static u32 *
1129 call_verify(struct rpc_task *task)
1130 {
1131         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1132         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1133         u32     *p = iov->iov_base, n;
1134         int error = -EACCES;
1135
1136         if ((len -= 3) < 0)
1137                 goto out_overflow;
1138         p += 1; /* skip XID */
1139
1140         if ((n = ntohl(*p++)) != RPC_REPLY) {
1141                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1142                 goto out_garbage;
1143         }
1144         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1145                 if (--len < 0)
1146                         goto out_overflow;
1147                 switch ((n = ntohl(*p++))) {
1148                         case RPC_AUTH_ERROR:
1149                                 break;
1150                         case RPC_MISMATCH:
1151                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1152                                 error = -EPROTONOSUPPORT;
1153                                 goto out_err;
1154                         default:
1155                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1156                                 goto out_eio;
1157                 }
1158                 if (--len < 0)
1159                         goto out_overflow;
1160                 switch ((n = ntohl(*p++))) {
1161                 case RPC_AUTH_REJECTEDCRED:
1162                 case RPC_AUTH_REJECTEDVERF:
1163                 case RPCSEC_GSS_CREDPROBLEM:
1164                 case RPCSEC_GSS_CTXPROBLEM:
1165                         if (!task->tk_cred_retry)
1166                                 break;
1167                         task->tk_cred_retry--;
1168                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1169                                                         task->tk_pid);
1170                         rpcauth_invalcred(task);
1171                         task->tk_action = call_refresh;
1172                         goto out_retry;
1173                 case RPC_AUTH_BADCRED:
1174                 case RPC_AUTH_BADVERF:
1175                         /* possibly garbled cred/verf? */
1176                         if (!task->tk_garb_retry)
1177                                 break;
1178                         task->tk_garb_retry--;
1179                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1180                                                         task->tk_pid);
1181                         task->tk_action = call_bind;
1182                         goto out_retry;
1183                 case RPC_AUTH_TOOWEAK:
1184                         printk(KERN_NOTICE "call_verify: server requires stronger "
1185                                "authentication.\n");
1186                         break;
1187                 default:
1188                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1189                         error = -EIO;
1190                 }
1191                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1192                                                 task->tk_pid, n);
1193                 goto out_err;
1194         }
1195         if (!(p = rpcauth_checkverf(task, p))) {
1196                 printk(KERN_WARNING "call_verify: auth check failed\n");
1197                 goto out_garbage;               /* bad verifier, retry */
1198         }
1199         len = p - (u32 *)iov->iov_base - 1;
1200         if (len < 0)
1201                 goto out_overflow;
1202         switch ((n = ntohl(*p++))) {
1203         case RPC_SUCCESS:
1204                 return p;
1205         case RPC_PROG_UNAVAIL:
1206                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1207                                 (unsigned int)task->tk_client->cl_prog,
1208                                 task->tk_client->cl_server);
1209                 error = -EPFNOSUPPORT;
1210                 goto out_err;
1211         case RPC_PROG_MISMATCH:
1212                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1213                                 (unsigned int)task->tk_client->cl_prog,
1214                                 (unsigned int)task->tk_client->cl_vers,
1215                                 task->tk_client->cl_server);
1216                 error = -EPROTONOSUPPORT;
1217                 goto out_err;
1218         case RPC_PROC_UNAVAIL:
1219                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1220                                 task->tk_msg.rpc_proc,
1221                                 task->tk_client->cl_prog,
1222                                 task->tk_client->cl_vers,
1223                                 task->tk_client->cl_server);
1224                 error = -EOPNOTSUPP;
1225                 goto out_err;
1226         case RPC_GARBAGE_ARGS:
1227                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1228                 break;                  /* retry */
1229         default:
1230                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1231                 /* Also retry */
1232         }
1233
1234 out_garbage:
1235         task->tk_client->cl_stats->rpcgarbage++;
1236         if (task->tk_garb_retry) {
1237                 task->tk_garb_retry--;
1238                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1239                 task->tk_action = call_bind;
1240 out_retry:
1241                 return ERR_PTR(-EAGAIN);
1242         }
1243         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1244 out_eio:
1245         error = -EIO;
1246 out_err:
1247         rpc_exit(task, error);
1248         return ERR_PTR(error);
1249 out_overflow:
1250         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1251         goto out_garbage;
1252 }
1253
1254 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1255 {
1256         return 0;
1257 }
1258
1259 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1260 {
1261         return 0;
1262 }
1263
1264 static struct rpc_procinfo rpcproc_null = {
1265         .p_encode = rpcproc_encode_null,
1266         .p_decode = rpcproc_decode_null,
1267 };
1268
1269 int rpc_ping(struct rpc_clnt *clnt, int flags)
1270 {
1271         struct rpc_message msg = {
1272                 .rpc_proc = &rpcproc_null,
1273         };
1274         int err;
1275         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1276         err = rpc_call_sync(clnt, &msg, flags);
1277         put_rpccred(msg.rpc_cred);
1278         return err;
1279 }