about summary refs log tree commit diff
path: root/sunrpc/svc.c
blob: 92343c694a053d997216b187d2f189154ff4a023 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
/*
 * svc.c, Server-side remote procedure call interface.
 *
 * There are two sets of procedures here.  The xprt routines are
 * for handling transport handles.  The svc routines handle the
 * list of service routines.
 *  Copyright (C) 2002-2022 Free Software Foundation, Inc.
 *  This file is part of the GNU C Library.
 *
 *  The GNU C Library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  The GNU C Library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with the GNU C Library; if not, see
 *  <https://www.gnu.org/licenses/>.
 *
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *     * Neither the name of the "Oracle America, Inc." nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <errno.h>
#include <unistd.h>
#include <rpc/rpc.h>
#include <rpc/svc.h>
#include <rpc/pmap_clnt.h>
#include <sys/poll.h>
#include <time.h>
#include <shlib-compat.h>

#define xports RPC_THREAD_VARIABLE(svc_xports_s)

#define NULL_SVC ((struct svc_callout *)0)
#define	RQCRED_SIZE	400	/* this size is excessive */

/* The services list
   Each entry represents a set of procedures (an rpc program).
   The dispatch routine takes request structs and runs the
   appropriate procedure. */
struct svc_callout {
  struct svc_callout *sc_next;
  rpcprog_t sc_prog;
  rpcvers_t sc_vers;
  void (*sc_dispatch) (struct svc_req *, SVCXPRT *);
  bool_t sc_mapped;
};
#define svc_head RPC_THREAD_VARIABLE(svc_head_s)

/* ***************  SVCXPRT related stuff **************** */

/* Activate a transport handle. */
void
xprt_register (SVCXPRT *xprt)
{
  register int sock = xprt->xp_sock;
  register int i;

  if (xports == NULL)
    {
      xports = (SVCXPRT **) calloc (_rpc_dtablesize (), sizeof (SVCXPRT *));
      if (xports == NULL) /* Don't add handle */
	return;
    }

  if (sock < _rpc_dtablesize ())
    {
      struct pollfd *new_svc_pollfd;

      xports[sock] = xprt;
      if (sock < FD_SETSIZE)
	FD_SET (sock, &svc_fdset);

      /* Check if we have an empty slot */
      for (i = 0; i < svc_max_pollfd; ++i)
	if (svc_pollfd[i].fd == -1)
	  {
	    svc_pollfd[i].fd = sock;
	    svc_pollfd[i].events = (POLLIN | POLLPRI |
				    POLLRDNORM | POLLRDBAND);
	    return;
	  }

      new_svc_pollfd = (struct pollfd *) realloc (svc_pollfd,
						  sizeof (struct pollfd)
						  * (svc_max_pollfd + 1));
      if (new_svc_pollfd == NULL) /* Out of memory */
	return;
      svc_pollfd = new_svc_pollfd;
      ++svc_max_pollfd;

      svc_pollfd[svc_max_pollfd - 1].fd = sock;
      svc_pollfd[svc_max_pollfd - 1].events = (POLLIN | POLLPRI |
					       POLLRDNORM | POLLRDBAND);
    }
}
libc_hidden_nolink_sunrpc (xprt_register, GLIBC_2_0)

/* De-activate a transport handle. */
void
xprt_unregister (SVCXPRT *xprt)
{
  register int sock = xprt->xp_sock;
  register int i;

  if ((sock < _rpc_dtablesize ()) && (xports[sock] == xprt))
    {
      xports[sock] = (SVCXPRT *) 0;

      if (sock < FD_SETSIZE)
	FD_CLR (sock, &svc_fdset);

      for (i = 0; i < svc_max_pollfd; ++i)
	if (svc_pollfd[i].fd == sock)
	  svc_pollfd[i].fd = -1;
    }
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (xprt_unregister)
#else
libc_hidden_nolink_sunrpc (xprt_unregister, GLIBC_2_0)
#endif


/* ********************** CALLOUT list related stuff ************* */

/* Search the callout list for a program number, return the callout
   struct. */
static struct svc_callout *
svc_find (rpcprog_t prog, rpcvers_t vers, struct svc_callout **prev)
{
  register struct svc_callout *s, *p;

  p = NULL_SVC;
  for (s = svc_head; s != NULL_SVC; s = s->sc_next)
    {
      if ((s->sc_prog == prog) && (s->sc_vers == vers))
	goto done;
      p = s;
    }
done:
  *prev = p;
  return s;
}

/* Add a service program to the callout list.
   The dispatch routine will be called when a rpc request for this
   program number comes in. */
bool_t
svc_register (SVCXPRT * xprt, rpcprog_t prog, rpcvers_t vers,
	      void (*dispatch) (struct svc_req *, SVCXPRT *),
	      rpcproc_t protocol)
{
  struct svc_callout *prev;
  register struct svc_callout *s;

  if ((s = svc_find (prog, vers, &prev)) != NULL_SVC)
    {
      if (s->sc_dispatch == dispatch)
	goto pmap_it;		/* he is registering another xptr */
      return FALSE;
    }
  s = (struct svc_callout *) mem_alloc (sizeof (struct svc_callout));
  if (s == (struct svc_callout *) 0)
    return FALSE;

  s->sc_prog = prog;
  s->sc_vers = vers;
  s->sc_dispatch = dispatch;
  s->sc_next = svc_head;
  s->sc_mapped = FALSE;
  svc_head = s;

pmap_it:
  /* now register the information with the local binder service */
  if (protocol)
    {
      if (! pmap_set (prog, vers, protocol, xprt->xp_port))
	return FALSE;

      s->sc_mapped = TRUE;
    }

  return TRUE;
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svc_register)
#else
libc_hidden_nolink_sunrpc (svc_register, GLIBC_2_0)
#endif

/* Remove a service program from the callout list. */
void
svc_unregister (rpcprog_t prog, rpcvers_t vers)
{
  struct svc_callout *prev;
  register struct svc_callout *s;

  if ((s = svc_find (prog, vers, &prev)) == NULL_SVC)
    return;
  bool is_mapped = s->sc_mapped;

  if (prev == NULL_SVC)
    svc_head = s->sc_next;
  else
    prev->sc_next = s->sc_next;

  s->sc_next = NULL_SVC;
  mem_free ((char *) s, (u_int) sizeof (struct svc_callout));
  /* now unregister the information with the local binder service */
  if (is_mapped)
    pmap_unset (prog, vers);
}
libc_hidden_nolink_sunrpc (svc_unregister, GLIBC_2_0)

/* ******************* REPLY GENERATION ROUTINES  ************ */

/* Send a reply to an rpc request */
bool_t
svc_sendreply (register SVCXPRT *xprt, xdrproc_t xdr_results,
	       caddr_t xdr_location)
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = SUCCESS;
  rply.acpted_rply.ar_results.where = xdr_location;
  rply.acpted_rply.ar_results.proc = xdr_results;
  return SVC_REPLY (xprt, &rply);
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svc_sendreply)
#else
libc_hidden_nolink_sunrpc (svc_sendreply, GLIBC_2_0)
#endif

/* No procedure error reply */
void
svcerr_noproc (register SVCXPRT *xprt)
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = PROC_UNAVAIL;
  SVC_REPLY (xprt, &rply);
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svcerr_noproc)
#else
libc_hidden_nolink_sunrpc (svcerr_noproc, GLIBC_2_0)
#endif

/* Can't decode args error reply */
void
svcerr_decode (register SVCXPRT *xprt)
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = GARBAGE_ARGS;
  SVC_REPLY (xprt, &rply);
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svcerr_decode)
#else
libc_hidden_nolink_sunrpc (svcerr_decode, GLIBC_2_0)
#endif

/* Some system error */
void
svcerr_systemerr (register SVCXPRT *xprt)
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = SYSTEM_ERR;
  SVC_REPLY (xprt, &rply);
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svcerr_systemerr)
#else
libc_hidden_nolink_sunrpc (svcerr_systemerr, GLIBC_2_0)
#endif

/* Authentication error reply */
void
svcerr_auth (SVCXPRT *xprt, enum auth_stat why)
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_DENIED;
  rply.rjcted_rply.rj_stat = AUTH_ERROR;
  rply.rjcted_rply.rj_why = why;
  SVC_REPLY (xprt, &rply);
}
libc_hidden_nolink_sunrpc (svcerr_auth, GLIBC_2_0)

/* Auth too weak error reply */
void
svcerr_weakauth (SVCXPRT *xprt)
{
  svcerr_auth (xprt, AUTH_TOOWEAK);
}
libc_hidden_nolink_sunrpc (svcerr_weakauth, GLIBC_2_0)

/* Program unavailable error reply */
void
svcerr_noprog (register SVCXPRT *xprt)
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = PROG_UNAVAIL;
  SVC_REPLY (xprt, &rply);
}
libc_hidden_nolink_sunrpc (svcerr_noprog, GLIBC_2_0)

/* Program version mismatch error reply */
void
svcerr_progvers (register SVCXPRT *xprt, rpcvers_t low_vers,
		 rpcvers_t high_vers)
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = PROG_MISMATCH;
  rply.acpted_rply.ar_vers.low = low_vers;
  rply.acpted_rply.ar_vers.high = high_vers;
  SVC_REPLY (xprt, &rply);
}
libc_hidden_nolink_sunrpc (svcerr_progvers, GLIBC_2_0)

/* ******************* SERVER INPUT STUFF ******************* */

/*
 * Get server side input from some transport.
 *
 * Statement of authentication parameters management:
 * This function owns and manages all authentication parameters, specifically
 * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
 * the "cooked" credentials (rqst->rq_clntcred).
 * However, this function does not know the structure of the cooked
 * credentials, so it make the following assumptions:
 *   a) the structure is contiguous (no pointers), and
 *   b) the cred structure size does not exceed RQCRED_SIZE bytes.
 * In all events, all three parameters are freed upon exit from this routine.
 * The storage is trivially management on the call stack in user land, but
 * is mallocated in kernel land.
 */

void
svc_getreq (int rdfds)
{
  fd_set readfds;

  FD_ZERO (&readfds);
  readfds.fds_bits[0] = rdfds;
  svc_getreqset (&readfds);
}
libc_hidden_nolink_sunrpc (svc_getreq, GLIBC_2_0)

void
svc_getreqset (fd_set *readfds)
{
  register fd_mask mask;
  register fd_mask *maskp;
  register int setsize;
  register int sock;
  register int bit;

  setsize = _rpc_dtablesize ();
  if (setsize > FD_SETSIZE)
    setsize = FD_SETSIZE;
  maskp = readfds->fds_bits;
  for (sock = 0; sock < setsize; sock += NFDBITS)
    for (mask = *maskp++; (bit = ffsl (mask)); mask ^= (1L << (bit - 1)))
      svc_getreq_common (sock + bit - 1);
}
libc_hidden_nolink_sunrpc (svc_getreqset, GLIBC_2_0)

void
svc_getreq_poll (struct pollfd *pfdp, int pollretval)
{
  if (pollretval == 0)
    return;

  register int fds_found;
  for (int i = fds_found = 0; i < svc_max_pollfd; ++i)
    {
      register struct pollfd *p = &pfdp[i];

      if (p->fd != -1 && p->revents)
	{
	  /* fd has input waiting */
	  if (p->revents & POLLNVAL)
	    xprt_unregister (xports[p->fd]);
	  else
	    svc_getreq_common (p->fd);

	  if (++fds_found >= pollretval)
	    break;
	}
    }
}
#ifdef EXPORT_RPC_SYMBOLS
libc_hidden_def (svc_getreq_poll)
#else
libc_hidden_nolink_sunrpc (svc_getreq_poll, GLIBC_2_2)
#endif


void
svc_getreq_common (const int fd)
{
  enum xprt_stat stat;
  struct rpc_msg msg;
  register SVCXPRT *xprt;
  char cred_area[2 * MAX_AUTH_BYTES + RQCRED_SIZE];
  msg.rm_call.cb_cred.oa_base = cred_area;
  msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);

  xprt = xports[fd];
  /* Do we control fd? */
  if (xprt == NULL)
     return;

  /* now receive msgs from xprtprt (support batch calls) */
  do
    {
      if (SVC_RECV (xprt, &msg))
	{
	  /* now find the exported program and call it */
	  struct svc_callout *s;
	  struct svc_req r;
	  enum auth_stat why;
	  rpcvers_t low_vers;
	  rpcvers_t high_vers;
	  int prog_found;

	  r.rq_clntcred = &(cred_area[2 * MAX_AUTH_BYTES]);
	  r.rq_xprt = xprt;
	  r.rq_prog = msg.rm_call.cb_prog;
	  r.rq_vers = msg.rm_call.cb_vers;
	  r.rq_proc = msg.rm_call.cb_proc;
	  r.rq_cred = msg.rm_call.cb_cred;

	  /* first authenticate the message */
	  /* Check for null flavor and bypass these calls if possible */

	  if (msg.rm_call.cb_cred.oa_flavor == AUTH_NULL)
	    {
	      r.rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
	      r.rq_xprt->xp_verf.oa_length = 0;
	    }
	  else if ((why = _authenticate (&r, &msg)) != AUTH_OK)
	    {
	      svcerr_auth (xprt, why);
	      goto call_done;
	    }

	  /* now match message with a registered service */
	  prog_found = FALSE;
	  low_vers = 0 - 1;
	  high_vers = 0;

	  for (s = svc_head; s != NULL_SVC; s = s->sc_next)
	    {
	      if (s->sc_prog == r.rq_prog)
		{
		  if (s->sc_vers == r.rq_vers)
		    {
		      (*s->sc_dispatch) (&r, xprt);
		      goto call_done;
		    }
		  /* found correct version */
		  prog_found = TRUE;
		  if (s->sc_vers < low_vers)
		    low_vers = s->sc_vers;
		  if (s->sc_vers > high_vers)
		    high_vers = s->sc_vers;
		}
	      /* found correct program */
	    }
	  /* if we got here, the program or version
	     is not served ... */
	  if (prog_found)
	    svcerr_progvers (xprt, low_vers, high_vers);
	  else
	    svcerr_noprog (xprt);
	  /* Fall through to ... */
	}
    call_done:
      if ((stat = SVC_STAT (xprt)) == XPRT_DIED)
	{
	  SVC_DESTROY (xprt);
	  break;
	}
    }
  while (stat == XPRT_MOREREQS);
}
libc_hidden_nolink_sunrpc (svc_getreq_common, GLIBC_2_2)

void
__svc_wait_on_error (void)
{
  struct timespec ts = { .tv_sec = 0, .tv_nsec = 50000000 };
  __nanosleep (&ts, NULL);
}

/* If there are no file descriptors available, then accept will fail.
   We want to delay here so the connection request can be dequeued;
   otherwise we can bounce between polling and accepting, never giving the
   request a chance to dequeue and eating an enormous amount of cpu time
   in svc_run if we're polling on many file descriptors.  */
void
__svc_accept_failed (void)
{
  if (errno == EMFILE)
    {
      __svc_wait_on_error ();
    }
}


void
__rpc_thread_svc_cleanup (void)
{
  struct svc_callout *svcp;

  while ((svcp = svc_head) != NULL)
    svc_unregister (svcp->sc_prog, svcp->sc_vers);
}