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