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) 2002-2017 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#include <shlib-compat.h>
63
64#ifdef _RPC_THREAD_SAFE_
65#define xports RPC_THREAD_VARIABLE(svc_xports_s)
66#else
67static SVCXPRT **xports;
68#endif
69
70#define NULL_SVC ((struct svc_callout *)0)
71#define RQCRED_SIZE 400 /* this size is excessive */
72
73/* The services list
74 Each entry represents a set of procedures (an rpc program).
75 The dispatch routine takes request structs and runs the
76 appropriate procedure. */
77struct svc_callout {
78 struct svc_callout *sc_next;
79 rpcprog_t sc_prog;
80 rpcvers_t sc_vers;
81 void (*sc_dispatch) (struct svc_req *, SVCXPRT *);
82 bool_t sc_mapped;
83};
84#ifdef _RPC_THREAD_SAFE_
85#define svc_head RPC_THREAD_VARIABLE(svc_head_s)
86#else
87static struct svc_callout *svc_head;
88#endif
89
90/* *************** SVCXPRT related stuff **************** */
91
92/* Activate a transport handle. */
93void
94xprt_register (SVCXPRT *xprt)
95{
96 register int sock = xprt->xp_sock;
97 register int i;
98
99 if (xports == NULL)
100 {
101 xports = (SVCXPRT **) calloc (_rpc_dtablesize (), sizeof (SVCXPRT *));
102 if (xports == NULL) /* Don't add handle */
103 return;
104 }
105
106 if (sock < _rpc_dtablesize ())
107 {
108 struct pollfd *new_svc_pollfd;
109
110 xports[sock] = xprt;
111 if (sock < FD_SETSIZE)
112 FD_SET (sock, &svc_fdset);
113
114 /* Check if we have an empty slot */
115 for (i = 0; i < svc_max_pollfd; ++i)
116 if (svc_pollfd[i].fd == -1)
117 {
118 svc_pollfd[i].fd = sock;
119 svc_pollfd[i].events = (POLLIN | POLLPRI |
120 POLLRDNORM | POLLRDBAND);
121 return;
122 }
123
124 new_svc_pollfd = (struct pollfd *) realloc (svc_pollfd,
125 sizeof (struct pollfd)
126 * (svc_max_pollfd + 1));
127 if (new_svc_pollfd == NULL) /* Out of memory */
128 return;
129 svc_pollfd = new_svc_pollfd;
130 ++svc_max_pollfd;
131
132 svc_pollfd[svc_max_pollfd - 1].fd = sock;
133 svc_pollfd[svc_max_pollfd - 1].events = (POLLIN | POLLPRI |
134 POLLRDNORM | POLLRDBAND);
135 }
136}
137libc_hidden_nolink_sunrpc (xprt_register, GLIBC_2_0)
138
139/* De-activate a transport handle. */
140void
141xprt_unregister (SVCXPRT *xprt)
142{
143 register int sock = xprt->xp_sock;
144 register int i;
145
146 if ((sock < _rpc_dtablesize ()) && (xports[sock] == xprt))
147 {
148 xports[sock] = (SVCXPRT *) 0;
149
150 if (sock < FD_SETSIZE)
151 FD_CLR (sock, &svc_fdset);
152
153 for (i = 0; i < svc_max_pollfd; ++i)
154 if (svc_pollfd[i].fd == sock)
155 svc_pollfd[i].fd = -1;
156 }
157}
158#ifdef EXPORT_RPC_SYMBOLS
159libc_hidden_def (xprt_unregister)
160#else
161libc_hidden_nolink_sunrpc (xprt_unregister, GLIBC_2_0)
162#endif
163
164
165/* ********************** CALLOUT list related stuff ************* */
166
167/* Search the callout list for a program number, return the callout
168 struct. */
169static struct svc_callout *
170svc_find (rpcprog_t prog, rpcvers_t vers, struct svc_callout **prev)
171{
172 register struct svc_callout *s, *p;
173
174 p = NULL_SVC;
175 for (s = svc_head; s != NULL_SVC; s = s->sc_next)
176 {
177 if ((s->sc_prog == prog) && (s->sc_vers == vers))
178 goto done;
179 p = s;
180 }
181done:
182 *prev = p;
183 return s;
184}
185
186/* Add a service program to the callout list.
187 The dispatch routine will be called when a rpc request for this
188 program number comes in. */
189bool_t
190svc_register (SVCXPRT * xprt, rpcprog_t prog, rpcvers_t vers,
191 void (*dispatch) (struct svc_req *, SVCXPRT *),
192 rpcproc_t protocol)
193{
194 struct svc_callout *prev;
195 register struct svc_callout *s;
196
197 if ((s = svc_find (prog, vers, &prev)) != NULL_SVC)
198 {
199 if (s->sc_dispatch == dispatch)
200 goto pmap_it; /* he is registering another xptr */
201 return FALSE;
202 }
203 s = (struct svc_callout *) mem_alloc (sizeof (struct svc_callout));
204 if (s == (struct svc_callout *) 0)
205 return FALSE;
206
207 s->sc_prog = prog;
208 s->sc_vers = vers;
209 s->sc_dispatch = dispatch;
210 s->sc_next = svc_head;
211 s->sc_mapped = FALSE;
212 svc_head = s;
213
214pmap_it:
215 /* now register the information with the local binder service */
216 if (protocol)
217 {
218 if (! pmap_set (prog, vers, protocol, xprt->xp_port))
219 return FALSE;
220
221 s->sc_mapped = TRUE;
222 }
223
224 return TRUE;
225}
226#ifdef EXPORT_RPC_SYMBOLS
227libc_hidden_def (svc_register)
228#else
229libc_hidden_nolink_sunrpc (svc_register, GLIBC_2_0)
230#endif
231
232/* Remove a service program from the callout list. */
233void
234svc_unregister (rpcprog_t prog, rpcvers_t vers)
235{
236 struct svc_callout *prev;
237 register struct svc_callout *s;
238
239 if ((s = svc_find (prog, vers, &prev)) == NULL_SVC)
240 return;
241 bool is_mapped = s->sc_mapped;
242
243 if (prev == NULL_SVC)
244 svc_head = s->sc_next;
245 else
246 prev->sc_next = s->sc_next;
247
248 s->sc_next = NULL_SVC;
249 mem_free ((char *) s, (u_int) sizeof (struct svc_callout));
250 /* now unregister the information with the local binder service */
251 if (is_mapped)
252 pmap_unset (prog, vers);
253}
254libc_hidden_nolink_sunrpc (svc_unregister, GLIBC_2_0)
255
256/* ******************* REPLY GENERATION ROUTINES ************ */
257
258/* Send a reply to an rpc request */
259bool_t
260svc_sendreply (register SVCXPRT *xprt, xdrproc_t xdr_results,
261 caddr_t xdr_location)
262{
263 struct rpc_msg rply;
264
265 rply.rm_direction = REPLY;
266 rply.rm_reply.rp_stat = MSG_ACCEPTED;
267 rply.acpted_rply.ar_verf = xprt->xp_verf;
268 rply.acpted_rply.ar_stat = SUCCESS;
269 rply.acpted_rply.ar_results.where = xdr_location;
270 rply.acpted_rply.ar_results.proc = xdr_results;
271 return SVC_REPLY (xprt, &rply);
272}
273#ifdef EXPORT_RPC_SYMBOLS
274libc_hidden_def (svc_sendreply)
275#else
276libc_hidden_nolink_sunrpc (svc_sendreply, GLIBC_2_0)
277#endif
278
279/* No procedure error reply */
280void
281svcerr_noproc (register SVCXPRT *xprt)
282{
283 struct rpc_msg rply;
284
285 rply.rm_direction = REPLY;
286 rply.rm_reply.rp_stat = MSG_ACCEPTED;
287 rply.acpted_rply.ar_verf = xprt->xp_verf;
288 rply.acpted_rply.ar_stat = PROC_UNAVAIL;
289 SVC_REPLY (xprt, &rply);
290}
291#ifdef EXPORT_RPC_SYMBOLS
292libc_hidden_def (svcerr_noproc)
293#else
294libc_hidden_nolink_sunrpc (svcerr_noproc, GLIBC_2_0)
295#endif
296
297/* Can't decode args error reply */
298void
299svcerr_decode (register SVCXPRT *xprt)
300{
301 struct rpc_msg rply;
302
303 rply.rm_direction = REPLY;
304 rply.rm_reply.rp_stat = MSG_ACCEPTED;
305 rply.acpted_rply.ar_verf = xprt->xp_verf;
306 rply.acpted_rply.ar_stat = GARBAGE_ARGS;
307 SVC_REPLY (xprt, &rply);
308}
309#ifdef EXPORT_RPC_SYMBOLS
310libc_hidden_def (svcerr_decode)
311#else
312libc_hidden_nolink_sunrpc (svcerr_decode, GLIBC_2_0)
313#endif
314
315/* Some system error */
316void
317svcerr_systemerr (register SVCXPRT *xprt)
318{
319 struct rpc_msg rply;
320
321 rply.rm_direction = REPLY;
322 rply.rm_reply.rp_stat = MSG_ACCEPTED;
323 rply.acpted_rply.ar_verf = xprt->xp_verf;
324 rply.acpted_rply.ar_stat = SYSTEM_ERR;
325 SVC_REPLY (xprt, &rply);
326}
327#ifdef EXPORT_RPC_SYMBOLS
328libc_hidden_def (svcerr_systemerr)
329#else
330libc_hidden_nolink_sunrpc (svcerr_systemerr, GLIBC_2_0)
331#endif
332
333/* Authentication error reply */
334void
335svcerr_auth (SVCXPRT *xprt, enum auth_stat why)
336{
337 struct rpc_msg rply;
338
339 rply.rm_direction = REPLY;
340 rply.rm_reply.rp_stat = MSG_DENIED;
341 rply.rjcted_rply.rj_stat = AUTH_ERROR;
342 rply.rjcted_rply.rj_why = why;
343 SVC_REPLY (xprt, &rply);
344}
345libc_hidden_nolink_sunrpc (svcerr_auth, GLIBC_2_0)
346
347/* Auth too weak error reply */
348void
349svcerr_weakauth (SVCXPRT *xprt)
350{
351 svcerr_auth (xprt, AUTH_TOOWEAK);
352}
353libc_hidden_nolink_sunrpc (svcerr_weakauth, GLIBC_2_0)
354
355/* Program unavailable error reply */
356void
357svcerr_noprog (register SVCXPRT *xprt)
358{
359 struct rpc_msg rply;
360
361 rply.rm_direction = REPLY;
362 rply.rm_reply.rp_stat = MSG_ACCEPTED;
363 rply.acpted_rply.ar_verf = xprt->xp_verf;
364 rply.acpted_rply.ar_stat = PROG_UNAVAIL;
365 SVC_REPLY (xprt, &rply);
366}
367libc_hidden_nolink_sunrpc (svcerr_noprog, GLIBC_2_0)
368
369/* Program version mismatch error reply */
370void
371svcerr_progvers (register SVCXPRT *xprt, rpcvers_t low_vers,
372 rpcvers_t high_vers)
373{
374 struct rpc_msg rply;
375
376 rply.rm_direction = REPLY;
377 rply.rm_reply.rp_stat = MSG_ACCEPTED;
378 rply.acpted_rply.ar_verf = xprt->xp_verf;
379 rply.acpted_rply.ar_stat = PROG_MISMATCH;
380 rply.acpted_rply.ar_vers.low = low_vers;
381 rply.acpted_rply.ar_vers.high = high_vers;
382 SVC_REPLY (xprt, &rply);
383}
384libc_hidden_nolink_sunrpc (svcerr_progvers, GLIBC_2_0)
385
386/* ******************* SERVER INPUT STUFF ******************* */
387
388/*
389 * Get server side input from some transport.
390 *
391 * Statement of authentication parameters management:
392 * This function owns and manages all authentication parameters, specifically
393 * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
394 * the "cooked" credentials (rqst->rq_clntcred).
395 * However, this function does not know the structure of the cooked
396 * credentials, so it make the following assumptions:
397 * a) the structure is contiguous (no pointers), and
398 * b) the cred structure size does not exceed RQCRED_SIZE bytes.
399 * In all events, all three parameters are freed upon exit from this routine.
400 * The storage is trivially management on the call stack in user land, but
401 * is mallocated in kernel land.
402 */
403
404void
405svc_getreq (int rdfds)
406{
407 fd_set readfds;
408
409 FD_ZERO (&readfds);
410 readfds.fds_bits[0] = rdfds;
411 svc_getreqset (&readfds);
412}
413libc_hidden_nolink_sunrpc (svc_getreq, GLIBC_2_0)
414
415void
416svc_getreqset (fd_set *readfds)
417{
418 register fd_mask mask;
419 register fd_mask *maskp;
420 register int setsize;
421 register int sock;
422 register int bit;
423
424 setsize = _rpc_dtablesize ();
425 if (setsize > FD_SETSIZE)
426 setsize = FD_SETSIZE;
427 maskp = readfds->fds_bits;
428 for (sock = 0; sock < setsize; sock += NFDBITS)
429 for (mask = *maskp++; (bit = ffsl (mask)); mask ^= (1L << (bit - 1)))
430 svc_getreq_common (sock + bit - 1);
431}
432libc_hidden_nolink_sunrpc (svc_getreqset, GLIBC_2_0)
433
434void
435svc_getreq_poll (struct pollfd *pfdp, int pollretval)
436{
437 if (pollretval == 0)
438 return;
439
440 register int fds_found;
441 for (int i = fds_found = 0; i < svc_max_pollfd; ++i)
442 {
443 register struct pollfd *p = &pfdp[i];
444
445 if (p->fd != -1 && p->revents)
446 {
447 /* fd has input waiting */
448 if (p->revents & POLLNVAL)
449 xprt_unregister (xports[p->fd]);
450 else
451 svc_getreq_common (p->fd);
452
453 if (++fds_found >= pollretval)
454 break;
455 }
456 }
457}
458#ifdef EXPORT_RPC_SYMBOLS
459libc_hidden_def (svc_getreq_poll)
460#else
461libc_hidden_nolink_sunrpc (svc_getreq_poll, GLIBC_2_2)
462#endif
463
464
465void
466svc_getreq_common (const int fd)
467{
468 enum xprt_stat stat;
469 struct rpc_msg msg;
470 register SVCXPRT *xprt;
471 char cred_area[2 * MAX_AUTH_BYTES + RQCRED_SIZE];
472 msg.rm_call.cb_cred.oa_base = cred_area;
473 msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
474
475 xprt = xports[fd];
476 /* Do we control fd? */
477 if (xprt == NULL)
478 return;
479
480 /* now receive msgs from xprtprt (support batch calls) */
481 do
482 {
483 if (SVC_RECV (xprt, &msg))
484 {
485 /* now find the exported program and call it */
486 struct svc_callout *s;
487 struct svc_req r;
488 enum auth_stat why;
489 rpcvers_t low_vers;
490 rpcvers_t high_vers;
491 int prog_found;
492
493 r.rq_clntcred = &(cred_area[2 * MAX_AUTH_BYTES]);
494 r.rq_xprt = xprt;
495 r.rq_prog = msg.rm_call.cb_prog;
496 r.rq_vers = msg.rm_call.cb_vers;
497 r.rq_proc = msg.rm_call.cb_proc;
498 r.rq_cred = msg.rm_call.cb_cred;
499
500 /* first authenticate the message */
501 /* Check for null flavor and bypass these calls if possible */
502
503 if (msg.rm_call.cb_cred.oa_flavor == AUTH_NULL)
504 {
505 r.rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
506 r.rq_xprt->xp_verf.oa_length = 0;
507 }
508 else if ((why = _authenticate (&r, &msg)) != AUTH_OK)
509 {
510 svcerr_auth (xprt, why);
511 goto call_done;
512 }
513
514 /* now match message with a registered service */
515 prog_found = FALSE;
516 low_vers = 0 - 1;
517 high_vers = 0;
518
519 for (s = svc_head; s != NULL_SVC; s = s->sc_next)
520 {
521 if (s->sc_prog == r.rq_prog)
522 {
523 if (s->sc_vers == r.rq_vers)
524 {
525 (*s->sc_dispatch) (&r, xprt);
526 goto call_done;
527 }
528 /* found correct version */
529 prog_found = TRUE;
530 if (s->sc_vers < low_vers)
531 low_vers = s->sc_vers;
532 if (s->sc_vers > high_vers)
533 high_vers = s->sc_vers;
534 }
535 /* found correct program */
536 }
537 /* if we got here, the program or version
538 is not served ... */
539 if (prog_found)
540 svcerr_progvers (xprt, low_vers, high_vers);
541 else
542 svcerr_noprog (xprt);
543 /* Fall through to ... */
544 }
545 call_done:
546 if ((stat = SVC_STAT (xprt)) == XPRT_DIED)
547 {
548 SVC_DESTROY (xprt);
549 break;
550 }
551 }
552 while (stat == XPRT_MOREREQS);
553}
554libc_hidden_nolink_sunrpc (svc_getreq_common, GLIBC_2_2)
555
556/* If there are no file descriptors available, then accept will fail.
557 We want to delay here so the connection request can be dequeued;
558 otherwise we can bounce between polling and accepting, never giving the
559 request a chance to dequeue and eating an enormous amount of cpu time
560 in svc_run if we're polling on many file descriptors. */
561void
562__svc_accept_failed (void)
563{
564 if (errno == EMFILE)
565 {
566 struct timespec ts = { .tv_sec = 0, .tv_nsec = 50000000 };
567 __nanosleep (&ts, NULL);
568 }
569}
570
571#ifdef _RPC_THREAD_SAFE_
572
573void
574__rpc_thread_svc_cleanup (void)
575{
576 struct svc_callout *svcp;
577
578 while ((svcp = svc_head) != NULL)
579 svc_unregister (svcp->sc_prog, svcp->sc_vers);
580}
581
582#endif /* _RPC_THREAD_SAFE_ */
583