1/*
2 * svc.c, Server-side remote procedure call interface.
3 *
4 * There are two sets of procedures here. The xprt routines are
5 * for handling transport handles. The svc routines handle the
6 * list of service routines.
7 * Copyright (C) 2002-2016 Free Software Foundation, Inc.
8 * This file is part of the GNU C Library.
9 * Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
10 *
11 * The GNU C Library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License as published by the Free Software Foundation; either
14 * version 2.1 of the License, or (at your option) any later version.
15 *
16 * The GNU C Library is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with the GNU C Library; if not, see
23 * <http://www.gnu.org/licenses/>.
24 *
25 * Copyright (c) 2010, Oracle America, Inc.
26 *
27 * Redistribution and use in source and binary forms, with or without
28 * modification, are permitted provided that the following conditions are
29 * met:
30 *
31 * * Redistributions of source code must retain the above copyright
32 * notice, this list of conditions and the following disclaimer.
33 * * Redistributions in binary form must reproduce the above
34 * copyright notice, this list of conditions and the following
35 * disclaimer in the documentation and/or other materials
36 * provided with the distribution.
37 * * Neither the name of the "Oracle America, Inc." nor the names of its
38 * contributors may be used to endorse or promote products derived
39 * from this software without specific prior written permission.
40 *
41 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
42 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
43 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
44 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
45 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
46 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
47 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
48 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
49 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
50 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
51 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
52 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
53 */
54
55#include <errno.h>
56#include <unistd.h>
57#include <rpc/rpc.h>
58#include <rpc/svc.h>
59#include <rpc/pmap_clnt.h>
60#include <sys/poll.h>
61#include <time.h>
62
63#ifdef _RPC_THREAD_SAFE_
64#define xports RPC_THREAD_VARIABLE(svc_xports_s)
65#else
66static SVCXPRT **xports;
67#endif
68
69#define NULL_SVC ((struct svc_callout *)0)
70#define RQCRED_SIZE 400 /* this size is excessive */
71
72/* The services list
73 Each entry represents a set of procedures (an rpc program).
74 The dispatch routine takes request structs and runs the
75 appropriate procedure. */
76struct svc_callout {
77 struct svc_callout *sc_next;
78 rpcprog_t sc_prog;
79 rpcvers_t sc_vers;
80 void (*sc_dispatch) (struct svc_req *, SVCXPRT *);
81 bool_t sc_mapped;
82};
83#ifdef _RPC_THREAD_SAFE_
84#define svc_head RPC_THREAD_VARIABLE(svc_head_s)
85#else
86static struct svc_callout *svc_head;
87#endif
88
89/* *************** SVCXPRT related stuff **************** */
90
91/* Activate a transport handle. */
92void
93xprt_register (SVCXPRT *xprt)
94{
95 register int sock = xprt->xp_sock;
96 register int i;
97
98 if (xports == NULL)
99 {
100 xports = (SVCXPRT **) calloc (_rpc_dtablesize (), sizeof (SVCXPRT *));
101 if (xports == NULL) /* Don't add handle */
102 return;
103 }
104
105 if (sock < _rpc_dtablesize ())
106 {
107 struct pollfd *new_svc_pollfd;
108
109 xports[sock] = xprt;
110 if (sock < FD_SETSIZE)
111 FD_SET (sock, &svc_fdset);
112
113 /* Check if we have an empty slot */
114 for (i = 0; i < svc_max_pollfd; ++i)
115 if (svc_pollfd[i].fd == -1)
116 {
117 svc_pollfd[i].fd = sock;
118 svc_pollfd[i].events = (POLLIN | POLLPRI |
119 POLLRDNORM | POLLRDBAND);
120 return;
121 }
122
123 new_svc_pollfd = (struct pollfd *) realloc (svc_pollfd,
124 sizeof (struct pollfd)
125 * (svc_max_pollfd + 1));
126 if (new_svc_pollfd == NULL) /* Out of memory */
127 return;
128 svc_pollfd = new_svc_pollfd;
129 ++svc_max_pollfd;
130
131 svc_pollfd[svc_max_pollfd - 1].fd = sock;
132 svc_pollfd[svc_max_pollfd - 1].events = (POLLIN | POLLPRI |
133 POLLRDNORM | POLLRDBAND);
134 }
135}
136libc_hidden_nolink_sunrpc (xprt_register, GLIBC_2_0)
137
138/* De-activate a transport handle. */
139void
140xprt_unregister (SVCXPRT *xprt)
141{
142 register int sock = xprt->xp_sock;
143 register int i;
144
145 if ((sock < _rpc_dtablesize ()) && (xports[sock] == xprt))
146 {
147 xports[sock] = (SVCXPRT *) 0;
148
149 if (sock < FD_SETSIZE)
150 FD_CLR (sock, &svc_fdset);
151
152 for (i = 0; i < svc_max_pollfd; ++i)
153 if (svc_pollfd[i].fd == sock)
154 svc_pollfd[i].fd = -1;
155 }
156}
157#ifdef EXPORT_RPC_SYMBOLS
158libc_hidden_def (xprt_unregister)
159#else
160libc_hidden_nolink_sunrpc (xprt_unregister, GLIBC_2_0)
161#endif
162
163
164/* ********************** CALLOUT list related stuff ************* */
165
166/* Search the callout list for a program number, return the callout
167 struct. */
168static struct svc_callout *
169svc_find (rpcprog_t prog, rpcvers_t vers, struct svc_callout **prev)
170{
171 register struct svc_callout *s, *p;
172
173 p = NULL_SVC;
174 for (s = svc_head; s != NULL_SVC; s = s->sc_next)
175 {
176 if ((s->sc_prog == prog) && (s->sc_vers == vers))
177 goto done;
178 p = s;
179 }
180done:
181 *prev = p;
182 return s;
183}
184
185
186static bool_t
187svc_is_mapped (rpcprog_t prog, rpcvers_t vers)
188{
189 struct svc_callout *prev;
190 register struct svc_callout *s;
191 s = svc_find (prog, vers, &prev);
192 return s!= NULL_SVC && s->sc_mapped;
193}
194
195
196/* Add a service program to the callout list.
197 The dispatch routine will be called when a rpc request for this
198 program number comes in. */
199bool_t
200svc_register (SVCXPRT * xprt, rpcprog_t prog, rpcvers_t vers,
201 void (*dispatch) (struct svc_req *, SVCXPRT *),
202 rpcproc_t protocol)
203{
204 struct svc_callout *prev;
205 register struct svc_callout *s;
206
207 if ((s = svc_find (prog, vers, &prev)) != NULL_SVC)
208 {
209 if (s->sc_dispatch == dispatch)
210 goto pmap_it; /* he is registering another xptr */
211 return FALSE;
212 }
213 s = (struct svc_callout *) mem_alloc (sizeof (struct svc_callout));
214 if (s == (struct svc_callout *) 0)
215 return FALSE;
216
217 s->sc_prog = prog;
218 s->sc_vers = vers;
219 s->sc_dispatch = dispatch;
220 s->sc_next = svc_head;
221 s->sc_mapped = FALSE;
222 svc_head = s;
223
224pmap_it:
225 /* now register the information with the local binder service */
226 if (protocol)
227 {
228 if (! pmap_set (prog, vers, protocol, xprt->xp_port))
229 return FALSE;
230
231 s->sc_mapped = TRUE;
232 }
233
234 return TRUE;
235}
236#ifdef EXPORT_RPC_SYMBOLS
237libc_hidden_def (svc_register)
238#else
239libc_hidden_nolink_sunrpc (svc_register, GLIBC_2_0)
240#endif
241
242/* Remove a service program from the callout list. */
243void
244svc_unregister (rpcprog_t prog, rpcvers_t vers)
245{
246 struct svc_callout *prev;
247 register struct svc_callout *s;
248
249 if ((s = svc_find (prog, vers, &prev)) == NULL_SVC)
250 return;
251
252 if (prev == NULL_SVC)
253 svc_head = s->sc_next;
254 else
255 prev->sc_next = s->sc_next;
256
257 s->sc_next = NULL_SVC;
258 mem_free ((char *) s, (u_int) sizeof (struct svc_callout));
259 /* now unregister the information with the local binder service */
260 if (! svc_is_mapped (prog, vers))
261 pmap_unset (prog, vers);
262}
263libc_hidden_nolink_sunrpc (svc_unregister, GLIBC_2_0)
264
265/* ******************* REPLY GENERATION ROUTINES ************ */
266
267/* Send a reply to an rpc request */
268bool_t
269svc_sendreply (register SVCXPRT *xprt, xdrproc_t xdr_results,
270 caddr_t xdr_location)
271{
272 struct rpc_msg rply;
273
274 rply.rm_direction = REPLY;
275 rply.rm_reply.rp_stat = MSG_ACCEPTED;
276 rply.acpted_rply.ar_verf = xprt->xp_verf;
277 rply.acpted_rply.ar_stat = SUCCESS;
278 rply.acpted_rply.ar_results.where = xdr_location;
279 rply.acpted_rply.ar_results.proc = xdr_results;
280 return SVC_REPLY (xprt, &rply);
281}
282#ifdef EXPORT_RPC_SYMBOLS
283libc_hidden_def (svc_sendreply)
284#else
285libc_hidden_nolink_sunrpc (svc_sendreply, GLIBC_2_0)
286#endif
287
288/* No procedure error reply */
289void
290svcerr_noproc (register SVCXPRT *xprt)
291{
292 struct rpc_msg rply;
293
294 rply.rm_direction = REPLY;
295 rply.rm_reply.rp_stat = MSG_ACCEPTED;
296 rply.acpted_rply.ar_verf = xprt->xp_verf;
297 rply.acpted_rply.ar_stat = PROC_UNAVAIL;
298 SVC_REPLY (xprt, &rply);
299}
300#ifdef EXPORT_RPC_SYMBOLS
301libc_hidden_def (svcerr_noproc)
302#else
303libc_hidden_nolink_sunrpc (svcerr_noproc, GLIBC_2_0)
304#endif
305
306/* Can't decode args error reply */
307void
308svcerr_decode (register SVCXPRT *xprt)
309{
310 struct rpc_msg rply;
311
312 rply.rm_direction = REPLY;
313 rply.rm_reply.rp_stat = MSG_ACCEPTED;
314 rply.acpted_rply.ar_verf = xprt->xp_verf;
315 rply.acpted_rply.ar_stat = GARBAGE_ARGS;
316 SVC_REPLY (xprt, &rply);
317}
318#ifdef EXPORT_RPC_SYMBOLS
319libc_hidden_def (svcerr_decode)
320#else
321libc_hidden_nolink_sunrpc (svcerr_decode, GLIBC_2_0)
322#endif
323
324/* Some system error */
325void
326svcerr_systemerr (register SVCXPRT *xprt)
327{
328 struct rpc_msg rply;
329
330 rply.rm_direction = REPLY;
331 rply.rm_reply.rp_stat = MSG_ACCEPTED;
332 rply.acpted_rply.ar_verf = xprt->xp_verf;
333 rply.acpted_rply.ar_stat = SYSTEM_ERR;
334 SVC_REPLY (xprt, &rply);
335}
336#ifdef EXPORT_RPC_SYMBOLS
337libc_hidden_def (svcerr_systemerr)
338#else
339libc_hidden_nolink_sunrpc (svcerr_systemerr, GLIBC_2_0)
340#endif
341
342/* Authentication error reply */
343void
344svcerr_auth (SVCXPRT *xprt, enum auth_stat why)
345{
346 struct rpc_msg rply;
347
348 rply.rm_direction = REPLY;
349 rply.rm_reply.rp_stat = MSG_DENIED;
350 rply.rjcted_rply.rj_stat = AUTH_ERROR;
351 rply.rjcted_rply.rj_why = why;
352 SVC_REPLY (xprt, &rply);
353}
354libc_hidden_nolink_sunrpc (svcerr_auth, GLIBC_2_0)
355
356/* Auth too weak error reply */
357void
358svcerr_weakauth (SVCXPRT *xprt)
359{
360 svcerr_auth (xprt, AUTH_TOOWEAK);
361}
362libc_hidden_nolink_sunrpc (svcerr_weakauth, GLIBC_2_0)
363
364/* Program unavailable error reply */
365void
366svcerr_noprog (register SVCXPRT *xprt)
367{
368 struct rpc_msg rply;
369
370 rply.rm_direction = REPLY;
371 rply.rm_reply.rp_stat = MSG_ACCEPTED;
372 rply.acpted_rply.ar_verf = xprt->xp_verf;
373 rply.acpted_rply.ar_stat = PROG_UNAVAIL;
374 SVC_REPLY (xprt, &rply);
375}
376libc_hidden_nolink_sunrpc (svcerr_noprog, GLIBC_2_0)
377
378/* Program version mismatch error reply */
379void
380svcerr_progvers (register SVCXPRT *xprt, rpcvers_t low_vers,
381 rpcvers_t high_vers)
382{
383 struct rpc_msg rply;
384
385 rply.rm_direction = REPLY;
386 rply.rm_reply.rp_stat = MSG_ACCEPTED;
387 rply.acpted_rply.ar_verf = xprt->xp_verf;
388 rply.acpted_rply.ar_stat = PROG_MISMATCH;
389 rply.acpted_rply.ar_vers.low = low_vers;
390 rply.acpted_rply.ar_vers.high = high_vers;
391 SVC_REPLY (xprt, &rply);
392}
393libc_hidden_nolink_sunrpc (svcerr_progvers, GLIBC_2_0)
394
395/* ******************* SERVER INPUT STUFF ******************* */
396
397/*
398 * Get server side input from some transport.
399 *
400 * Statement of authentication parameters management:
401 * This function owns and manages all authentication parameters, specifically
402 * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
403 * the "cooked" credentials (rqst->rq_clntcred).
404 * However, this function does not know the structure of the cooked
405 * credentials, so it make the following assumptions:
406 * a) the structure is contiguous (no pointers), and
407 * b) the cred structure size does not exceed RQCRED_SIZE bytes.
408 * In all events, all three parameters are freed upon exit from this routine.
409 * The storage is trivially management on the call stack in user land, but
410 * is mallocated in kernel land.
411 */
412
413void
414svc_getreq (int rdfds)
415{
416 fd_set readfds;
417
418 FD_ZERO (&readfds);
419 readfds.fds_bits[0] = rdfds;
420 svc_getreqset (&readfds);
421}
422libc_hidden_nolink_sunrpc (svc_getreq, GLIBC_2_0)
423
424void
425svc_getreqset (fd_set *readfds)
426{
427 register fd_mask mask;
428 register fd_mask *maskp;
429 register int setsize;
430 register int sock;
431 register int bit;
432
433 setsize = _rpc_dtablesize ();
434 if (setsize > FD_SETSIZE)
435 setsize = FD_SETSIZE;
436 maskp = readfds->fds_bits;
437 for (sock = 0; sock < setsize; sock += NFDBITS)
438 for (mask = *maskp++; (bit = ffsl (mask)); mask ^= (1L << (bit - 1)))
439 svc_getreq_common (sock + bit - 1);
440}
441libc_hidden_nolink_sunrpc (svc_getreqset, GLIBC_2_0)
442
443void
444svc_getreq_poll (struct pollfd *pfdp, int pollretval)
445{
446 if (pollretval == 0)
447 return;
448
449 register int fds_found;
450 for (int i = fds_found = 0; i < svc_max_pollfd; ++i)
451 {
452 register struct pollfd *p = &pfdp[i];
453
454 if (p->fd != -1 && p->revents)
455 {
456 /* fd has input waiting */
457 if (p->revents & POLLNVAL)
458 xprt_unregister (xports[p->fd]);
459 else
460 svc_getreq_common (p->fd);
461
462 if (++fds_found >= pollretval)
463 break;
464 }
465 }
466}
467#ifdef EXPORT_RPC_SYMBOLS
468libc_hidden_def (svc_getreq_poll)
469#else
470libc_hidden_nolink_sunrpc (svc_getreq_poll, GLIBC_2_2)
471#endif
472
473
474void
475svc_getreq_common (const int fd)
476{
477 enum xprt_stat stat;
478 struct rpc_msg msg;
479 register SVCXPRT *xprt;
480 char cred_area[2 * MAX_AUTH_BYTES + RQCRED_SIZE];
481 msg.rm_call.cb_cred.oa_base = cred_area;
482 msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
483
484 xprt = xports[fd];
485 /* Do we control fd? */
486 if (xprt == NULL)
487 return;
488
489 /* now receive msgs from xprtprt (support batch calls) */
490 do
491 {
492 if (SVC_RECV (xprt, &msg))
493 {
494 /* now find the exported program and call it */
495 struct svc_callout *s;
496 struct svc_req r;
497 enum auth_stat why;
498 rpcvers_t low_vers;
499 rpcvers_t high_vers;
500 int prog_found;
501
502 r.rq_clntcred = &(cred_area[2 * MAX_AUTH_BYTES]);
503 r.rq_xprt = xprt;
504 r.rq_prog = msg.rm_call.cb_prog;
505 r.rq_vers = msg.rm_call.cb_vers;
506 r.rq_proc = msg.rm_call.cb_proc;
507 r.rq_cred = msg.rm_call.cb_cred;
508
509 /* first authenticate the message */
510 /* Check for null flavor and bypass these calls if possible */
511
512 if (msg.rm_call.cb_cred.oa_flavor == AUTH_NULL)
513 {
514 r.rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
515 r.rq_xprt->xp_verf.oa_length = 0;
516 }
517 else if ((why = _authenticate (&r, &msg)) != AUTH_OK)
518 {
519 svcerr_auth (xprt, why);
520 goto call_done;
521 }
522
523 /* now match message with a registered service */
524 prog_found = FALSE;
525 low_vers = 0 - 1;
526 high_vers = 0;
527
528 for (s = svc_head; s != NULL_SVC; s = s->sc_next)
529 {
530 if (s->sc_prog == r.rq_prog)
531 {
532 if (s->sc_vers == r.rq_vers)
533 {
534 (*s->sc_dispatch) (&r, xprt);
535 goto call_done;
536 }
537 /* found correct version */
538 prog_found = TRUE;
539 if (s->sc_vers < low_vers)
540 low_vers = s->sc_vers;
541 if (s->sc_vers > high_vers)
542 high_vers = s->sc_vers;
543 }
544 /* found correct program */
545 }
546 /* if we got here, the program or version
547 is not served ... */
548 if (prog_found)
549 svcerr_progvers (xprt, low_vers, high_vers);
550 else
551 svcerr_noprog (xprt);
552 /* Fall through to ... */
553 }
554 call_done:
555 if ((stat = SVC_STAT (xprt)) == XPRT_DIED)
556 {
557 SVC_DESTROY (xprt);
558 break;
559 }
560 }
561 while (stat == XPRT_MOREREQS);
562}
563libc_hidden_nolink_sunrpc (svc_getreq_common, GLIBC_2_2)
564
565/* If there are no file descriptors available, then accept will fail.
566 We want to delay here so the connection request can be dequeued;
567 otherwise we can bounce between polling and accepting, never giving the
568 request a chance to dequeue and eating an enormous amount of cpu time
569 in svc_run if we're polling on many file descriptors. */
570void
571__svc_accept_failed (void)
572{
573 if (errno == EMFILE)
574 {
575 struct timespec ts = { .tv_sec = 0, .tv_nsec = 50000000 };
576 __nanosleep (&ts, NULL);
577 }
578}
579
580#ifdef _RPC_THREAD_SAFE_
581
582void
583__rpc_thread_svc_cleanup (void)
584{
585 struct svc_callout *svcp;
586
587 while ((svcp = svc_head) != NULL)
588 svc_unregister (svcp->sc_prog, svcp->sc_vers);
589}
590
591#endif /* _RPC_THREAD_SAFE_ */
592