Pull ia64-mutex-primitives into release branch
[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_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_no_xprt;
117         if (vers >= program->nrvers || !(version = program->version[vers]))
118                 goto out_err;
119
120         err = -ENOMEM;
121         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 out_no_xprt:
186         return ERR_PTR(err);
187 }
188
189 /**
190  * Create an RPC client
191  * @xprt - pointer to xprt struct
192  * @servname - name of server
193  * @info - rpc_program
194  * @version - rpc_program version
195  * @authflavor - rpc_auth flavour to use
196  *
197  * Creates an RPC client structure, then pings the server in order to
198  * determine if it is up, and if it supports this program and version.
199  *
200  * This function should never be called by asynchronous tasks such as
201  * the portmapper.
202  */
203 struct rpc_clnt *rpc_create_client(struct rpc_xprt *xprt, char *servname,
204                 struct rpc_program *info, u32 version, rpc_authflavor_t authflavor)
205 {
206         struct rpc_clnt *clnt;
207         int err;
208         
209         clnt = rpc_new_client(xprt, servname, info, version, authflavor);
210         if (IS_ERR(clnt))
211                 return clnt;
212         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
213         if (err == 0)
214                 return clnt;
215         rpc_shutdown_client(clnt);
216         return ERR_PTR(err);
217 }
218
219 /*
220  * This function clones the RPC client structure. It allows us to share the
221  * same transport while varying parameters such as the authentication
222  * flavour.
223  */
224 struct rpc_clnt *
225 rpc_clone_client(struct rpc_clnt *clnt)
226 {
227         struct rpc_clnt *new;
228
229         new = kmalloc(sizeof(*new), GFP_KERNEL);
230         if (!new)
231                 goto out_no_clnt;
232         memcpy(new, clnt, sizeof(*new));
233         atomic_set(&new->cl_count, 1);
234         atomic_set(&new->cl_users, 0);
235         new->cl_parent = clnt;
236         atomic_inc(&clnt->cl_count);
237         /* Duplicate portmapper */
238         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
239         /* Turn off autobind on clones */
240         new->cl_autobind = 0;
241         new->cl_oneshot = 0;
242         new->cl_dead = 0;
243         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
244         if (new->cl_auth)
245                 atomic_inc(&new->cl_auth->au_count);
246         new->cl_pmap            = &new->cl_pmap_default;
247         rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
248         return new;
249 out_no_clnt:
250         printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
251         return ERR_PTR(-ENOMEM);
252 }
253
254 /*
255  * Properly shut down an RPC client, terminating all outstanding
256  * requests. Note that we must be certain that cl_oneshot and
257  * cl_dead are cleared, or else the client would be destroyed
258  * when the last task releases it.
259  */
260 int
261 rpc_shutdown_client(struct rpc_clnt *clnt)
262 {
263         dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
264                         clnt->cl_protname, clnt->cl_server,
265                         atomic_read(&clnt->cl_users));
266
267         while (atomic_read(&clnt->cl_users) > 0) {
268                 /* Don't let rpc_release_client destroy us */
269                 clnt->cl_oneshot = 0;
270                 clnt->cl_dead = 0;
271                 rpc_killall_tasks(clnt);
272                 wait_event_timeout(destroy_wait,
273                         !atomic_read(&clnt->cl_users), 1*HZ);
274         }
275
276         if (atomic_read(&clnt->cl_users) < 0) {
277                 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
278                                 clnt, atomic_read(&clnt->cl_users));
279 #ifdef RPC_DEBUG
280                 rpc_show_tasks();
281 #endif
282                 BUG();
283         }
284
285         return rpc_destroy_client(clnt);
286 }
287
288 /*
289  * Delete an RPC client
290  */
291 int
292 rpc_destroy_client(struct rpc_clnt *clnt)
293 {
294         if (!atomic_dec_and_test(&clnt->cl_count))
295                 return 1;
296         BUG_ON(atomic_read(&clnt->cl_users) != 0);
297
298         dprintk("RPC: destroying %s client for %s\n",
299                         clnt->cl_protname, clnt->cl_server);
300         if (clnt->cl_auth) {
301                 rpcauth_destroy(clnt->cl_auth);
302                 clnt->cl_auth = NULL;
303         }
304         if (clnt->cl_parent != clnt) {
305                 rpc_destroy_client(clnt->cl_parent);
306                 goto out_free;
307         }
308         if (clnt->cl_pathname[0])
309                 rpc_rmdir(clnt->cl_pathname);
310         if (clnt->cl_xprt) {
311                 xprt_destroy(clnt->cl_xprt);
312                 clnt->cl_xprt = NULL;
313         }
314         if (clnt->cl_server != clnt->cl_inline_name)
315                 kfree(clnt->cl_server);
316 out_free:
317         kfree(clnt);
318         return 0;
319 }
320
321 /*
322  * Release an RPC client
323  */
324 void
325 rpc_release_client(struct rpc_clnt *clnt)
326 {
327         dprintk("RPC:      rpc_release_client(%p, %d)\n",
328                                 clnt, atomic_read(&clnt->cl_users));
329
330         if (!atomic_dec_and_test(&clnt->cl_users))
331                 return;
332         wake_up(&destroy_wait);
333         if (clnt->cl_oneshot || clnt->cl_dead)
334                 rpc_destroy_client(clnt);
335 }
336
337 /**
338  * rpc_bind_new_program - bind a new RPC program to an existing client
339  * @old - old rpc_client
340  * @program - rpc program to set
341  * @vers - rpc program version
342  *
343  * Clones the rpc client and sets up a new RPC program. This is mainly
344  * of use for enabling different RPC programs to share the same transport.
345  * The Sun NFSv2/v3 ACL protocol can do this.
346  */
347 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
348                                       struct rpc_program *program,
349                                       int vers)
350 {
351         struct rpc_clnt *clnt;
352         struct rpc_version *version;
353         int err;
354
355         BUG_ON(vers >= program->nrvers || !program->version[vers]);
356         version = program->version[vers];
357         clnt = rpc_clone_client(old);
358         if (IS_ERR(clnt))
359                 goto out;
360         clnt->cl_procinfo = version->procs;
361         clnt->cl_maxproc  = version->nrprocs;
362         clnt->cl_protname = program->name;
363         clnt->cl_prog     = program->number;
364         clnt->cl_vers     = version->number;
365         clnt->cl_stats    = program->stats;
366         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
367         if (err != 0) {
368                 rpc_shutdown_client(clnt);
369                 clnt = ERR_PTR(err);
370         }
371 out:    
372         return clnt;
373 }
374
375 /*
376  * Default callback for async RPC calls
377  */
378 static void
379 rpc_default_callback(struct rpc_task *task, void *data)
380 {
381 }
382
383 static const struct rpc_call_ops rpc_default_ops = {
384         .rpc_call_done = rpc_default_callback,
385 };
386
387 /*
388  *      Export the signal mask handling for synchronous code that
389  *      sleeps on RPC calls
390  */
391 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
392  
393 static void rpc_save_sigmask(sigset_t *oldset, int intr)
394 {
395         unsigned long   sigallow = sigmask(SIGKILL);
396         sigset_t sigmask;
397
398         /* Block all signals except those listed in sigallow */
399         if (intr)
400                 sigallow |= RPC_INTR_SIGNALS;
401         siginitsetinv(&sigmask, sigallow);
402         sigprocmask(SIG_BLOCK, &sigmask, oldset);
403 }
404
405 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
406 {
407         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
408 }
409
410 static inline void rpc_restore_sigmask(sigset_t *oldset)
411 {
412         sigprocmask(SIG_SETMASK, oldset, NULL);
413 }
414
415 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
416 {
417         rpc_save_sigmask(oldset, clnt->cl_intr);
418 }
419
420 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
421 {
422         rpc_restore_sigmask(oldset);
423 }
424
425 /*
426  * New rpc_call implementation
427  */
428 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
429 {
430         struct rpc_task *task;
431         sigset_t        oldset;
432         int             status;
433
434         /* If this client is slain all further I/O fails */
435         if (clnt->cl_dead) 
436                 return -EIO;
437
438         BUG_ON(flags & RPC_TASK_ASYNC);
439
440         status = -ENOMEM;
441         task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL);
442         if (task == NULL)
443                 goto out;
444
445         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
446         rpc_task_sigmask(task, &oldset);
447
448         rpc_call_setup(task, msg, 0);
449
450         /* Set up the call info struct and execute the task */
451         status = task->tk_status;
452         if (status == 0) {
453                 atomic_inc(&task->tk_count);
454                 status = rpc_execute(task);
455                 if (status == 0)
456                         status = task->tk_status;
457         }
458         rpc_restore_sigmask(&oldset);
459         rpc_release_task(task);
460 out:
461         return status;
462 }
463
464 /*
465  * New rpc_call implementation
466  */
467 int
468 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
469                const struct rpc_call_ops *tk_ops, void *data)
470 {
471         struct rpc_task *task;
472         sigset_t        oldset;
473         int             status;
474
475         /* If this client is slain all further I/O fails */
476         if (clnt->cl_dead) 
477                 return -EIO;
478
479         flags |= RPC_TASK_ASYNC;
480
481         /* Create/initialize a new RPC task */
482         status = -ENOMEM;
483         if (!(task = rpc_new_task(clnt, flags, tk_ops, data)))
484                 goto out;
485
486         /* Mask signals on GSS_AUTH upcalls */
487         rpc_task_sigmask(task, &oldset);                
488
489         rpc_call_setup(task, msg, 0);
490
491         /* Set up the call info struct and execute the task */
492         status = task->tk_status;
493         if (status == 0)
494                 rpc_execute(task);
495         else
496                 rpc_release_task(task);
497
498         rpc_restore_sigmask(&oldset);           
499 out:
500         return status;
501 }
502
503
504 void
505 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
506 {
507         task->tk_msg   = *msg;
508         task->tk_flags |= flags;
509         /* Bind the user cred */
510         if (task->tk_msg.rpc_cred != NULL)
511                 rpcauth_holdcred(task);
512         else
513                 rpcauth_bindcred(task);
514
515         if (task->tk_status == 0)
516                 task->tk_action = call_start;
517         else
518                 task->tk_action = rpc_exit_task;
519 }
520
521 void
522 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
523 {
524         struct rpc_xprt *xprt = clnt->cl_xprt;
525         if (xprt->ops->set_buffer_size)
526                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
527 }
528
529 /*
530  * Return size of largest payload RPC client can support, in bytes
531  *
532  * For stream transports, this is one RPC record fragment (see RFC
533  * 1831), as we don't support multi-record requests yet.  For datagram
534  * transports, this is the size of an IP packet minus the IP, UDP, and
535  * RPC header sizes.
536  */
537 size_t rpc_max_payload(struct rpc_clnt *clnt)
538 {
539         return clnt->cl_xprt->max_payload;
540 }
541 EXPORT_SYMBOL(rpc_max_payload);
542
543 /**
544  * rpc_force_rebind - force transport to check that remote port is unchanged
545  * @clnt: client to rebind
546  *
547  */
548 void rpc_force_rebind(struct rpc_clnt *clnt)
549 {
550         if (clnt->cl_autobind)
551                 clnt->cl_port = 0;
552 }
553 EXPORT_SYMBOL(rpc_force_rebind);
554
555 /*
556  * Restart an (async) RPC call. Usually called from within the
557  * exit handler.
558  */
559 void
560 rpc_restart_call(struct rpc_task *task)
561 {
562         if (RPC_ASSASSINATED(task))
563                 return;
564
565         task->tk_action = call_start;
566 }
567
568 /*
569  * 0.  Initial state
570  *
571  *     Other FSM states can be visited zero or more times, but
572  *     this state is visited exactly once for each RPC.
573  */
574 static void
575 call_start(struct rpc_task *task)
576 {
577         struct rpc_clnt *clnt = task->tk_client;
578
579         dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
580                 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
581                 (RPC_IS_ASYNC(task) ? "async" : "sync"));
582
583         /* Increment call count */
584         task->tk_msg.rpc_proc->p_count++;
585         clnt->cl_stats->rpccnt++;
586         task->tk_action = call_reserve;
587 }
588
589 /*
590  * 1.   Reserve an RPC call slot
591  */
592 static void
593 call_reserve(struct rpc_task *task)
594 {
595         dprintk("RPC: %4d call_reserve\n", task->tk_pid);
596
597         if (!rpcauth_uptodatecred(task)) {
598                 task->tk_action = call_refresh;
599                 return;
600         }
601
602         task->tk_status  = 0;
603         task->tk_action  = call_reserveresult;
604         xprt_reserve(task);
605 }
606
607 /*
608  * 1b.  Grok the result of xprt_reserve()
609  */
610 static void
611 call_reserveresult(struct rpc_task *task)
612 {
613         int status = task->tk_status;
614
615         dprintk("RPC: %4d call_reserveresult (status %d)\n",
616                                 task->tk_pid, task->tk_status);
617
618         /*
619          * After a call to xprt_reserve(), we must have either
620          * a request slot or else an error status.
621          */
622         task->tk_status = 0;
623         if (status >= 0) {
624                 if (task->tk_rqstp) {
625                         task->tk_action = call_allocate;
626                         return;
627                 }
628
629                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
630                                 __FUNCTION__, status);
631                 rpc_exit(task, -EIO);
632                 return;
633         }
634
635         /*
636          * Even though there was an error, we may have acquired
637          * a request slot somehow.  Make sure not to leak it.
638          */
639         if (task->tk_rqstp) {
640                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
641                                 __FUNCTION__, status);
642                 xprt_release(task);
643         }
644
645         switch (status) {
646         case -EAGAIN:   /* woken up; retry */
647                 task->tk_action = call_reserve;
648                 return;
649         case -EIO:      /* probably a shutdown */
650                 break;
651         default:
652                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
653                                 __FUNCTION__, status);
654                 break;
655         }
656         rpc_exit(task, status);
657 }
658
659 /*
660  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
661  *      (Note: buffer memory is freed in xprt_release).
662  */
663 static void
664 call_allocate(struct rpc_task *task)
665 {
666         struct rpc_rqst *req = task->tk_rqstp;
667         struct rpc_xprt *xprt = task->tk_xprt;
668         unsigned int    bufsiz;
669
670         dprintk("RPC: %4d call_allocate (status %d)\n", 
671                                 task->tk_pid, task->tk_status);
672         task->tk_action = call_bind;
673         if (req->rq_buffer)
674                 return;
675
676         /* FIXME: compute buffer requirements more exactly using
677          * auth->au_wslack */
678         bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
679
680         if (xprt->ops->buf_alloc(task, bufsiz << 1) != NULL)
681                 return;
682         printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task); 
683
684         if (RPC_IS_ASYNC(task) || !signalled()) {
685                 xprt_release(task);
686                 task->tk_action = call_reserve;
687                 rpc_delay(task, HZ>>4);
688                 return;
689         }
690
691         rpc_exit(task, -ERESTARTSYS);
692 }
693
694 static inline int
695 rpc_task_need_encode(struct rpc_task *task)
696 {
697         return task->tk_rqstp->rq_snd_buf.len == 0;
698 }
699
700 static inline void
701 rpc_task_force_reencode(struct rpc_task *task)
702 {
703         task->tk_rqstp->rq_snd_buf.len = 0;
704 }
705
706 /*
707  * 3.   Encode arguments of an RPC call
708  */
709 static void
710 call_encode(struct rpc_task *task)
711 {
712         struct rpc_rqst *req = task->tk_rqstp;
713         struct xdr_buf *sndbuf = &req->rq_snd_buf;
714         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
715         unsigned int    bufsiz;
716         kxdrproc_t      encode;
717         u32             *p;
718
719         dprintk("RPC: %4d call_encode (status %d)\n", 
720                                 task->tk_pid, task->tk_status);
721
722         /* Default buffer setup */
723         bufsiz = req->rq_bufsize >> 1;
724         sndbuf->head[0].iov_base = (void *)req->rq_buffer;
725         sndbuf->head[0].iov_len  = bufsiz;
726         sndbuf->tail[0].iov_len  = 0;
727         sndbuf->page_len         = 0;
728         sndbuf->len              = 0;
729         sndbuf->buflen           = bufsiz;
730         rcvbuf->head[0].iov_base = (void *)((char *)req->rq_buffer + bufsiz);
731         rcvbuf->head[0].iov_len  = bufsiz;
732         rcvbuf->tail[0].iov_len  = 0;
733         rcvbuf->page_len         = 0;
734         rcvbuf->len              = 0;
735         rcvbuf->buflen           = bufsiz;
736
737         /* Encode header and provided arguments */
738         encode = task->tk_msg.rpc_proc->p_encode;
739         if (!(p = call_header(task))) {
740                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
741                 rpc_exit(task, -EIO);
742                 return;
743         }
744         if (encode == NULL)
745                 return;
746
747         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
748                         task->tk_msg.rpc_argp);
749         if (task->tk_status == -ENOMEM) {
750                 /* XXX: Is this sane? */
751                 rpc_delay(task, 3*HZ);
752                 task->tk_status = -EAGAIN;
753         }
754 }
755
756 /*
757  * 4.   Get the server port number if not yet set
758  */
759 static void
760 call_bind(struct rpc_task *task)
761 {
762         struct rpc_clnt *clnt = task->tk_client;
763
764         dprintk("RPC: %4d call_bind (status %d)\n",
765                                 task->tk_pid, task->tk_status);
766
767         task->tk_action = call_connect;
768         if (!clnt->cl_port) {
769                 task->tk_action = call_bind_status;
770                 task->tk_timeout = task->tk_xprt->bind_timeout;
771                 rpc_getport(task, clnt);
772         }
773 }
774
775 /*
776  * 4a.  Sort out bind result
777  */
778 static void
779 call_bind_status(struct rpc_task *task)
780 {
781         int status = -EACCES;
782
783         if (task->tk_status >= 0) {
784                 dprintk("RPC: %4d call_bind_status (status %d)\n",
785                                         task->tk_pid, task->tk_status);
786                 task->tk_status = 0;
787                 task->tk_action = call_connect;
788                 return;
789         }
790
791         switch (task->tk_status) {
792         case -EACCES:
793                 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
794                                 task->tk_pid);
795                 rpc_delay(task, 3*HZ);
796                 goto retry_bind;
797         case -ETIMEDOUT:
798                 dprintk("RPC: %4d rpcbind request timed out\n",
799                                 task->tk_pid);
800                 if (RPC_IS_SOFT(task)) {
801                         status = -EIO;
802                         break;
803                 }
804                 goto retry_bind;
805         case -EPFNOSUPPORT:
806                 dprintk("RPC: %4d remote rpcbind service unavailable\n",
807                                 task->tk_pid);
808                 break;
809         case -EPROTONOSUPPORT:
810                 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
811                                 task->tk_pid);
812                 break;
813         default:
814                 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
815                                 task->tk_pid, -task->tk_status);
816                 status = -EIO;
817                 break;
818         }
819
820         rpc_exit(task, status);
821         return;
822
823 retry_bind:
824         task->tk_status = 0;
825         task->tk_action = call_bind;
826         return;
827 }
828
829 /*
830  * 4b.  Connect to the RPC server
831  */
832 static void
833 call_connect(struct rpc_task *task)
834 {
835         struct rpc_xprt *xprt = task->tk_xprt;
836
837         dprintk("RPC: %4d call_connect xprt %p %s connected\n",
838                         task->tk_pid, xprt,
839                         (xprt_connected(xprt) ? "is" : "is not"));
840
841         task->tk_action = call_transmit;
842         if (!xprt_connected(xprt)) {
843                 task->tk_action = call_connect_status;
844                 if (task->tk_status < 0)
845                         return;
846                 xprt_connect(task);
847         }
848 }
849
850 /*
851  * 4c.  Sort out connect result
852  */
853 static void
854 call_connect_status(struct rpc_task *task)
855 {
856         struct rpc_clnt *clnt = task->tk_client;
857         int status = task->tk_status;
858
859         dprintk("RPC: %5u call_connect_status (status %d)\n", 
860                                 task->tk_pid, task->tk_status);
861
862         task->tk_status = 0;
863         if (status >= 0) {
864                 clnt->cl_stats->netreconn++;
865                 task->tk_action = call_transmit;
866                 return;
867         }
868
869         /* Something failed: remote service port may have changed */
870         rpc_force_rebind(clnt);
871
872         switch (status) {
873         case -ENOTCONN:
874         case -ETIMEDOUT:
875         case -EAGAIN:
876                 task->tk_action = call_bind;
877                 break;
878         default:
879                 rpc_exit(task, -EIO);
880                 break;
881         }
882 }
883
884 /*
885  * 5.   Transmit the RPC request, and wait for reply
886  */
887 static void
888 call_transmit(struct rpc_task *task)
889 {
890         dprintk("RPC: %4d call_transmit (status %d)\n", 
891                                 task->tk_pid, task->tk_status);
892
893         task->tk_action = call_status;
894         if (task->tk_status < 0)
895                 return;
896         task->tk_status = xprt_prepare_transmit(task);
897         if (task->tk_status != 0)
898                 return;
899         /* Encode here so that rpcsec_gss can use correct sequence number. */
900         if (rpc_task_need_encode(task)) {
901                 task->tk_rqstp->rq_bytes_sent = 0;
902                 call_encode(task);
903                 /* Did the encode result in an error condition? */
904                 if (task->tk_status != 0)
905                         goto out_nosend;
906         }
907         task->tk_action = call_transmit_status;
908         xprt_transmit(task);
909         if (task->tk_status < 0)
910                 return;
911         if (!task->tk_msg.rpc_proc->p_decode) {
912                 task->tk_action = rpc_exit_task;
913                 rpc_wake_up_task(task);
914         }
915         return;
916 out_nosend:
917         /* release socket write lock before attempting to handle error */
918         xprt_abort_transmit(task);
919         rpc_task_force_reencode(task);
920 }
921
922 /*
923  * 6.   Sort out the RPC call status
924  */
925 static void
926 call_status(struct rpc_task *task)
927 {
928         struct rpc_clnt *clnt = task->tk_client;
929         struct rpc_rqst *req = task->tk_rqstp;
930         int             status;
931
932         if (req->rq_received > 0 && !req->rq_bytes_sent)
933                 task->tk_status = req->rq_received;
934
935         dprintk("RPC: %4d call_status (status %d)\n", 
936                                 task->tk_pid, task->tk_status);
937
938         status = task->tk_status;
939         if (status >= 0) {
940                 task->tk_action = call_decode;
941                 return;
942         }
943
944         task->tk_status = 0;
945         switch(status) {
946         case -ETIMEDOUT:
947                 task->tk_action = call_timeout;
948                 break;
949         case -ECONNREFUSED:
950         case -ENOTCONN:
951                 rpc_force_rebind(clnt);
952                 task->tk_action = call_bind;
953                 break;
954         case -EAGAIN:
955                 task->tk_action = call_transmit;
956                 break;
957         case -EIO:
958                 /* shutdown or soft timeout */
959                 rpc_exit(task, status);
960                 break;
961         default:
962                 printk("%s: RPC call returned error %d\n",
963                                clnt->cl_protname, -status);
964                 rpc_exit(task, status);
965                 break;
966         }
967 }
968
969 /*
970  * 6a.  Handle transmission errors.
971  */
972 static void
973 call_transmit_status(struct rpc_task *task)
974 {
975         if (task->tk_status != -EAGAIN)
976                 rpc_task_force_reencode(task);
977         call_status(task);
978 }
979
980 /*
981  * 6b.  Handle RPC timeout
982  *      We do not release the request slot, so we keep using the
983  *      same XID for all retransmits.
984  */
985 static void
986 call_timeout(struct rpc_task *task)
987 {
988         struct rpc_clnt *clnt = task->tk_client;
989
990         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
991                 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
992                 goto retry;
993         }
994
995         dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
996         if (RPC_IS_SOFT(task)) {
997                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
998                                 clnt->cl_protname, clnt->cl_server);
999                 rpc_exit(task, -EIO);
1000                 return;
1001         }
1002
1003         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1004                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1005                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1006                         clnt->cl_protname, clnt->cl_server);
1007         }
1008         rpc_force_rebind(clnt);
1009
1010 retry:
1011         clnt->cl_stats->rpcretrans++;
1012         task->tk_action = call_bind;
1013         task->tk_status = 0;
1014 }
1015
1016 /*
1017  * 7.   Decode the RPC reply
1018  */
1019 static void
1020 call_decode(struct rpc_task *task)
1021 {
1022         struct rpc_clnt *clnt = task->tk_client;
1023         struct rpc_rqst *req = task->tk_rqstp;
1024         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1025         u32             *p;
1026
1027         dprintk("RPC: %4d call_decode (status %d)\n", 
1028                                 task->tk_pid, task->tk_status);
1029
1030         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1031                 printk(KERN_NOTICE "%s: server %s OK\n",
1032                         clnt->cl_protname, clnt->cl_server);
1033                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1034         }
1035
1036         if (task->tk_status < 12) {
1037                 if (!RPC_IS_SOFT(task)) {
1038                         task->tk_action = call_bind;
1039                         clnt->cl_stats->rpcretrans++;
1040                         goto out_retry;
1041                 }
1042                 printk(KERN_WARNING "%s: too small RPC reply size (%d bytes)\n",
1043                         clnt->cl_protname, task->tk_status);
1044                 rpc_exit(task, -EIO);
1045                 return;
1046         }
1047
1048         req->rq_rcv_buf.len = req->rq_private_buf.len;
1049
1050         /* Check that the softirq receive buffer is valid */
1051         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1052                                 sizeof(req->rq_rcv_buf)) != 0);
1053
1054         /* Verify the RPC header */
1055         p = call_verify(task);
1056         if (IS_ERR(p)) {
1057                 if (p == ERR_PTR(-EAGAIN))
1058                         goto out_retry;
1059                 return;
1060         }
1061
1062         task->tk_action = rpc_exit_task;
1063
1064         if (decode)
1065                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1066                                                       task->tk_msg.rpc_resp);
1067         dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1068                                         task->tk_status);
1069         return;
1070 out_retry:
1071         req->rq_received = req->rq_private_buf.len = 0;
1072         task->tk_status = 0;
1073 }
1074
1075 /*
1076  * 8.   Refresh the credentials if rejected by the server
1077  */
1078 static void
1079 call_refresh(struct rpc_task *task)
1080 {
1081         dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1082
1083         xprt_release(task);     /* Must do to obtain new XID */
1084         task->tk_action = call_refreshresult;
1085         task->tk_status = 0;
1086         task->tk_client->cl_stats->rpcauthrefresh++;
1087         rpcauth_refreshcred(task);
1088 }
1089
1090 /*
1091  * 8a.  Process the results of a credential refresh
1092  */
1093 static void
1094 call_refreshresult(struct rpc_task *task)
1095 {
1096         int status = task->tk_status;
1097         dprintk("RPC: %4d call_refreshresult (status %d)\n", 
1098                                 task->tk_pid, task->tk_status);
1099
1100         task->tk_status = 0;
1101         task->tk_action = call_reserve;
1102         if (status >= 0 && rpcauth_uptodatecred(task))
1103                 return;
1104         if (status == -EACCES) {
1105                 rpc_exit(task, -EACCES);
1106                 return;
1107         }
1108         task->tk_action = call_refresh;
1109         if (status != -ETIMEDOUT)
1110                 rpc_delay(task, 3*HZ);
1111         return;
1112 }
1113
1114 /*
1115  * Call header serialization
1116  */
1117 static u32 *
1118 call_header(struct rpc_task *task)
1119 {
1120         struct rpc_clnt *clnt = task->tk_client;
1121         struct rpc_rqst *req = task->tk_rqstp;
1122         u32             *p = req->rq_svec[0].iov_base;
1123
1124         /* FIXME: check buffer size? */
1125
1126         p = xprt_skip_transport_header(task->tk_xprt, p);
1127         *p++ = req->rq_xid;             /* XID */
1128         *p++ = htonl(RPC_CALL);         /* CALL */
1129         *p++ = htonl(RPC_VERSION);      /* RPC version */
1130         *p++ = htonl(clnt->cl_prog);    /* program number */
1131         *p++ = htonl(clnt->cl_vers);    /* program version */
1132         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1133         p = rpcauth_marshcred(task, p);
1134         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1135         return p;
1136 }
1137
1138 /*
1139  * Reply header verification
1140  */
1141 static u32 *
1142 call_verify(struct rpc_task *task)
1143 {
1144         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1145         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1146         u32     *p = iov->iov_base, n;
1147         int error = -EACCES;
1148
1149         if ((len -= 3) < 0)
1150                 goto out_overflow;
1151         p += 1; /* skip XID */
1152
1153         if ((n = ntohl(*p++)) != RPC_REPLY) {
1154                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1155                 goto out_garbage;
1156         }
1157         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1158                 if (--len < 0)
1159                         goto out_overflow;
1160                 switch ((n = ntohl(*p++))) {
1161                         case RPC_AUTH_ERROR:
1162                                 break;
1163                         case RPC_MISMATCH:
1164                                 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1165                                 error = -EPROTONOSUPPORT;
1166                                 goto out_err;
1167                         default:
1168                                 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1169                                 goto out_eio;
1170                 }
1171                 if (--len < 0)
1172                         goto out_overflow;
1173                 switch ((n = ntohl(*p++))) {
1174                 case RPC_AUTH_REJECTEDCRED:
1175                 case RPC_AUTH_REJECTEDVERF:
1176                 case RPCSEC_GSS_CREDPROBLEM:
1177                 case RPCSEC_GSS_CTXPROBLEM:
1178                         if (!task->tk_cred_retry)
1179                                 break;
1180                         task->tk_cred_retry--;
1181                         dprintk("RPC: %4d call_verify: retry stale creds\n",
1182                                                         task->tk_pid);
1183                         rpcauth_invalcred(task);
1184                         task->tk_action = call_refresh;
1185                         goto out_retry;
1186                 case RPC_AUTH_BADCRED:
1187                 case RPC_AUTH_BADVERF:
1188                         /* possibly garbled cred/verf? */
1189                         if (!task->tk_garb_retry)
1190                                 break;
1191                         task->tk_garb_retry--;
1192                         dprintk("RPC: %4d call_verify: retry garbled creds\n",
1193                                                         task->tk_pid);
1194                         task->tk_action = call_bind;
1195                         goto out_retry;
1196                 case RPC_AUTH_TOOWEAK:
1197                         printk(KERN_NOTICE "call_verify: server requires stronger "
1198                                "authentication.\n");
1199                         break;
1200                 default:
1201                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1202                         error = -EIO;
1203                 }
1204                 dprintk("RPC: %4d call_verify: call rejected %d\n",
1205                                                 task->tk_pid, n);
1206                 goto out_err;
1207         }
1208         if (!(p = rpcauth_checkverf(task, p))) {
1209                 printk(KERN_WARNING "call_verify: auth check failed\n");
1210                 goto out_garbage;               /* bad verifier, retry */
1211         }
1212         len = p - (u32 *)iov->iov_base - 1;
1213         if (len < 0)
1214                 goto out_overflow;
1215         switch ((n = ntohl(*p++))) {
1216         case RPC_SUCCESS:
1217                 return p;
1218         case RPC_PROG_UNAVAIL:
1219                 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1220                                 (unsigned int)task->tk_client->cl_prog,
1221                                 task->tk_client->cl_server);
1222                 error = -EPFNOSUPPORT;
1223                 goto out_err;
1224         case RPC_PROG_MISMATCH:
1225                 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1226                                 (unsigned int)task->tk_client->cl_prog,
1227                                 (unsigned int)task->tk_client->cl_vers,
1228                                 task->tk_client->cl_server);
1229                 error = -EPROTONOSUPPORT;
1230                 goto out_err;
1231         case RPC_PROC_UNAVAIL:
1232                 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1233                                 task->tk_msg.rpc_proc,
1234                                 task->tk_client->cl_prog,
1235                                 task->tk_client->cl_vers,
1236                                 task->tk_client->cl_server);
1237                 error = -EOPNOTSUPP;
1238                 goto out_err;
1239         case RPC_GARBAGE_ARGS:
1240                 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1241                 break;                  /* retry */
1242         default:
1243                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1244                 /* Also retry */
1245         }
1246
1247 out_garbage:
1248         task->tk_client->cl_stats->rpcgarbage++;
1249         if (task->tk_garb_retry) {
1250                 task->tk_garb_retry--;
1251                 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1252                 task->tk_action = call_bind;
1253 out_retry:
1254                 return ERR_PTR(-EAGAIN);
1255         }
1256         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1257 out_eio:
1258         error = -EIO;
1259 out_err:
1260         rpc_exit(task, error);
1261         return ERR_PTR(error);
1262 out_overflow:
1263         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1264         goto out_garbage;
1265 }
1266
1267 static int rpcproc_encode_null(void *rqstp, u32 *data, void *obj)
1268 {
1269         return 0;
1270 }
1271
1272 static int rpcproc_decode_null(void *rqstp, u32 *data, void *obj)
1273 {
1274         return 0;
1275 }
1276
1277 static struct rpc_procinfo rpcproc_null = {
1278         .p_encode = rpcproc_encode_null,
1279         .p_decode = rpcproc_decode_null,
1280 };
1281
1282 int rpc_ping(struct rpc_clnt *clnt, int flags)
1283 {
1284         struct rpc_message msg = {
1285                 .rpc_proc = &rpcproc_null,
1286         };
1287         int err;
1288         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1289         err = rpc_call_sync(clnt, &msg, flags);
1290         put_rpccred(msg.rpc_cred);
1291         return err;
1292 }