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) 2002-2020 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 * <https://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#define xports RPC_THREAD_VARIABLE(svc_xports_s)
65
66#define NULL_SVC ((struct svc_callout *)0)
67#define RQCRED_SIZE 400 /* this size is excessive */
68
69/* The services list
70 Each entry represents a set of procedures (an rpc program).
71 The dispatch routine takes request structs and runs the
72 appropriate procedure. */
73struct svc_callout {
74 struct svc_callout *sc_next;
75 rpcprog_t sc_prog;
76 rpcvers_t sc_vers;
77 void (*sc_dispatch) (struct svc_req *, SVCXPRT *);
78 bool_t sc_mapped;
79};
80#define svc_head RPC_THREAD_VARIABLE(svc_head_s)
81
82/* *************** SVCXPRT related stuff **************** */
83
84/* Activate a transport handle. */
85void
86xprt_register (SVCXPRT *xprt)
87{
88 register int sock = xprt->xp_sock;
89 register int i;
90
91 if (xports == NULL)
92 {
93 xports = (SVCXPRT **) calloc (_rpc_dtablesize (), sizeof (SVCXPRT *));
94 if (xports == NULL) /* Don't add handle */
95 return;
96 }
97
98 if (sock < _rpc_dtablesize ())
99 {
100 struct pollfd *new_svc_pollfd;
101
102 xports[sock] = xprt;
103 if (sock < FD_SETSIZE)
104 FD_SET (sock, &svc_fdset);
105
106 /* Check if we have an empty slot */
107 for (i = 0; i < svc_max_pollfd; ++i)
108 if (svc_pollfd[i].fd == -1)
109 {
110 svc_pollfd[i].fd = sock;
111 svc_pollfd[i].events = (POLLIN | POLLPRI |
112 POLLRDNORM | POLLRDBAND);
113 return;
114 }
115
116 new_svc_pollfd = (struct pollfd *) realloc (svc_pollfd,
117 sizeof (struct pollfd)
118 * (svc_max_pollfd + 1));
119 if (new_svc_pollfd == NULL) /* Out of memory */
120 return;
121 svc_pollfd = new_svc_pollfd;
122 ++svc_max_pollfd;
123
124 svc_pollfd[svc_max_pollfd - 1].fd = sock;
125 svc_pollfd[svc_max_pollfd - 1].events = (POLLIN | POLLPRI |
126 POLLRDNORM | POLLRDBAND);
127 }
128}
129libc_hidden_nolink_sunrpc (xprt_register, GLIBC_2_0)
130
131/* De-activate a transport handle. */
132void
133xprt_unregister (SVCXPRT *xprt)
134{
135 register int sock = xprt->xp_sock;
136 register int i;
137
138 if ((sock < _rpc_dtablesize ()) && (xports[sock] == xprt))
139 {
140 xports[sock] = (SVCXPRT *) 0;
141
142 if (sock < FD_SETSIZE)
143 FD_CLR (sock, &svc_fdset);
144
145 for (i = 0; i < svc_max_pollfd; ++i)
146 if (svc_pollfd[i].fd == sock)
147 svc_pollfd[i].fd = -1;
148 }
149}
150#ifdef EXPORT_RPC_SYMBOLS
151libc_hidden_def (xprt_unregister)
152#else
153libc_hidden_nolink_sunrpc (xprt_unregister, GLIBC_2_0)
154#endif
155
156
157/* ********************** CALLOUT list related stuff ************* */
158
159/* Search the callout list for a program number, return the callout
160 struct. */
161static struct svc_callout *
162svc_find (rpcprog_t prog, rpcvers_t vers, struct svc_callout **prev)
163{
164 register struct svc_callout *s, *p;
165
166 p = NULL_SVC;
167 for (s = svc_head; s != NULL_SVC; s = s->sc_next)
168 {
169 if ((s->sc_prog == prog) && (s->sc_vers == vers))
170 goto done;
171 p = s;
172 }
173done:
174 *prev = p;
175 return s;
176}
177
178/* Add a service program to the callout list.
179 The dispatch routine will be called when a rpc request for this
180 program number comes in. */
181bool_t
182svc_register (SVCXPRT * xprt, rpcprog_t prog, rpcvers_t vers,
183 void (*dispatch) (struct svc_req *, SVCXPRT *),
184 rpcproc_t protocol)
185{
186 struct svc_callout *prev;
187 register struct svc_callout *s;
188
189 if ((s = svc_find (prog, vers, &prev)) != NULL_SVC)
190 {
191 if (s->sc_dispatch == dispatch)
192 goto pmap_it; /* he is registering another xptr */
193 return FALSE;
194 }
195 s = (struct svc_callout *) mem_alloc (sizeof (struct svc_callout));
196 if (s == (struct svc_callout *) 0)
197 return FALSE;
198
199 s->sc_prog = prog;
200 s->sc_vers = vers;
201 s->sc_dispatch = dispatch;
202 s->sc_next = svc_head;
203 s->sc_mapped = FALSE;
204 svc_head = s;
205
206pmap_it:
207 /* now register the information with the local binder service */
208 if (protocol)
209 {
210 if (! pmap_set (prog, vers, protocol, xprt->xp_port))
211 return FALSE;
212
213 s->sc_mapped = TRUE;
214 }
215
216 return TRUE;
217}
218#ifdef EXPORT_RPC_SYMBOLS
219libc_hidden_def (svc_register)
220#else
221libc_hidden_nolink_sunrpc (svc_register, GLIBC_2_0)
222#endif
223
224/* Remove a service program from the callout list. */
225void
226svc_unregister (rpcprog_t prog, rpcvers_t vers)
227{
228 struct svc_callout *prev;
229 register struct svc_callout *s;
230
231 if ((s = svc_find (prog, vers, &prev)) == NULL_SVC)
232 return;
233 bool is_mapped = s->sc_mapped;
234
235 if (prev == NULL_SVC)
236 svc_head = s->sc_next;
237 else
238 prev->sc_next = s->sc_next;
239
240 s->sc_next = NULL_SVC;
241 mem_free ((char *) s, (u_int) sizeof (struct svc_callout));
242 /* now unregister the information with the local binder service */
243 if (is_mapped)
244 pmap_unset (prog, vers);
245}
246libc_hidden_nolink_sunrpc (svc_unregister, GLIBC_2_0)
247
248/* ******************* REPLY GENERATION ROUTINES ************ */
249
250/* Send a reply to an rpc request */
251bool_t
252svc_sendreply (register SVCXPRT *xprt, xdrproc_t xdr_results,
253 caddr_t xdr_location)
254{
255 struct rpc_msg rply;
256
257 rply.rm_direction = REPLY;
258 rply.rm_reply.rp_stat = MSG_ACCEPTED;
259 rply.acpted_rply.ar_verf = xprt->xp_verf;
260 rply.acpted_rply.ar_stat = SUCCESS;
261 rply.acpted_rply.ar_results.where = xdr_location;
262 rply.acpted_rply.ar_results.proc = xdr_results;
263 return SVC_REPLY (xprt, &rply);
264}
265#ifdef EXPORT_RPC_SYMBOLS
266libc_hidden_def (svc_sendreply)
267#else
268libc_hidden_nolink_sunrpc (svc_sendreply, GLIBC_2_0)
269#endif
270
271/* No procedure error reply */
272void
273svcerr_noproc (register SVCXPRT *xprt)
274{
275 struct rpc_msg rply;
276
277 rply.rm_direction = REPLY;
278 rply.rm_reply.rp_stat = MSG_ACCEPTED;
279 rply.acpted_rply.ar_verf = xprt->xp_verf;
280 rply.acpted_rply.ar_stat = PROC_UNAVAIL;
281 SVC_REPLY (xprt, &rply);
282}
283#ifdef EXPORT_RPC_SYMBOLS
284libc_hidden_def (svcerr_noproc)
285#else
286libc_hidden_nolink_sunrpc (svcerr_noproc, GLIBC_2_0)
287#endif
288
289/* Can't decode args error reply */
290void
291svcerr_decode (register SVCXPRT *xprt)
292{
293 struct rpc_msg rply;
294
295 rply.rm_direction = REPLY;
296 rply.rm_reply.rp_stat = MSG_ACCEPTED;
297 rply.acpted_rply.ar_verf = xprt->xp_verf;
298 rply.acpted_rply.ar_stat = GARBAGE_ARGS;
299 SVC_REPLY (xprt, &rply);
300}
301#ifdef EXPORT_RPC_SYMBOLS
302libc_hidden_def (svcerr_decode)
303#else
304libc_hidden_nolink_sunrpc (svcerr_decode, GLIBC_2_0)
305#endif
306
307/* Some system error */
308void
309svcerr_systemerr (register SVCXPRT *xprt)
310{
311 struct rpc_msg rply;
312
313 rply.rm_direction = REPLY;
314 rply.rm_reply.rp_stat = MSG_ACCEPTED;
315 rply.acpted_rply.ar_verf = xprt->xp_verf;
316 rply.acpted_rply.ar_stat = SYSTEM_ERR;
317 SVC_REPLY (xprt, &rply);
318}
319#ifdef EXPORT_RPC_SYMBOLS
320libc_hidden_def (svcerr_systemerr)
321#else
322libc_hidden_nolink_sunrpc (svcerr_systemerr, GLIBC_2_0)
323#endif
324
325/* Authentication error reply */
326void
327svcerr_auth (SVCXPRT *xprt, enum auth_stat why)
328{
329 struct rpc_msg rply;
330
331 rply.rm_direction = REPLY;
332 rply.rm_reply.rp_stat = MSG_DENIED;
333 rply.rjcted_rply.rj_stat = AUTH_ERROR;
334 rply.rjcted_rply.rj_why = why;
335 SVC_REPLY (xprt, &rply);
336}
337libc_hidden_nolink_sunrpc (svcerr_auth, GLIBC_2_0)
338
339/* Auth too weak error reply */
340void
341svcerr_weakauth (SVCXPRT *xprt)
342{
343 svcerr_auth (xprt, AUTH_TOOWEAK);
344}
345libc_hidden_nolink_sunrpc (svcerr_weakauth, GLIBC_2_0)
346
347/* Program unavailable error reply */
348void
349svcerr_noprog (register SVCXPRT *xprt)
350{
351 struct rpc_msg rply;
352
353 rply.rm_direction = REPLY;
354 rply.rm_reply.rp_stat = MSG_ACCEPTED;
355 rply.acpted_rply.ar_verf = xprt->xp_verf;
356 rply.acpted_rply.ar_stat = PROG_UNAVAIL;
357 SVC_REPLY (xprt, &rply);
358}
359libc_hidden_nolink_sunrpc (svcerr_noprog, GLIBC_2_0)
360
361/* Program version mismatch error reply */
362void
363svcerr_progvers (register SVCXPRT *xprt, rpcvers_t low_vers,
364 rpcvers_t high_vers)
365{
366 struct rpc_msg rply;
367
368 rply.rm_direction = REPLY;
369 rply.rm_reply.rp_stat = MSG_ACCEPTED;
370 rply.acpted_rply.ar_verf = xprt->xp_verf;
371 rply.acpted_rply.ar_stat = PROG_MISMATCH;
372 rply.acpted_rply.ar_vers.low = low_vers;
373 rply.acpted_rply.ar_vers.high = high_vers;
374 SVC_REPLY (xprt, &rply);
375}
376libc_hidden_nolink_sunrpc (svcerr_progvers, GLIBC_2_0)
377
378/* ******************* SERVER INPUT STUFF ******************* */
379
380/*
381 * Get server side input from some transport.
382 *
383 * Statement of authentication parameters management:
384 * This function owns and manages all authentication parameters, specifically
385 * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
386 * the "cooked" credentials (rqst->rq_clntcred).
387 * However, this function does not know the structure of the cooked
388 * credentials, so it make the following assumptions:
389 * a) the structure is contiguous (no pointers), and
390 * b) the cred structure size does not exceed RQCRED_SIZE bytes.
391 * In all events, all three parameters are freed upon exit from this routine.
392 * The storage is trivially management on the call stack in user land, but
393 * is mallocated in kernel land.
394 */
395
396void
397svc_getreq (int rdfds)
398{
399 fd_set readfds;
400
401 FD_ZERO (&readfds);
402 readfds.fds_bits[0] = rdfds;
403 svc_getreqset (&readfds);
404}
405libc_hidden_nolink_sunrpc (svc_getreq, GLIBC_2_0)
406
407void
408svc_getreqset (fd_set *readfds)
409{
410 register fd_mask mask;
411 register fd_mask *maskp;
412 register int setsize;
413 register int sock;
414 register int bit;
415
416 setsize = _rpc_dtablesize ();
417 if (setsize > FD_SETSIZE)
418 setsize = FD_SETSIZE;
419 maskp = readfds->fds_bits;
420 for (sock = 0; sock < setsize; sock += NFDBITS)
421 for (mask = *maskp++; (bit = ffsl (mask)); mask ^= (1L << (bit - 1)))
422 svc_getreq_common (sock + bit - 1);
423}
424libc_hidden_nolink_sunrpc (svc_getreqset, GLIBC_2_0)
425
426void
427svc_getreq_poll (struct pollfd *pfdp, int pollretval)
428{
429 if (pollretval == 0)
430 return;
431
432 register int fds_found;
433 for (int i = fds_found = 0; i < svc_max_pollfd; ++i)
434 {
435 register struct pollfd *p = &pfdp[i];
436
437 if (p->fd != -1 && p->revents)
438 {
439 /* fd has input waiting */
440 if (p->revents & POLLNVAL)
441 xprt_unregister (xports[p->fd]);
442 else
443 svc_getreq_common (p->fd);
444
445 if (++fds_found >= pollretval)
446 break;
447 }
448 }
449}
450#ifdef EXPORT_RPC_SYMBOLS
451libc_hidden_def (svc_getreq_poll)
452#else
453libc_hidden_nolink_sunrpc (svc_getreq_poll, GLIBC_2_2)
454#endif
455
456
457void
458svc_getreq_common (const int fd)
459{
460 enum xprt_stat stat;
461 struct rpc_msg msg;
462 register SVCXPRT *xprt;
463 char cred_area[2 * MAX_AUTH_BYTES + RQCRED_SIZE];
464 msg.rm_call.cb_cred.oa_base = cred_area;
465 msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
466
467 xprt = xports[fd];
468 /* Do we control fd? */
469 if (xprt == NULL)
470 return;
471
472 /* now receive msgs from xprtprt (support batch calls) */
473 do
474 {
475 if (SVC_RECV (xprt, &msg))
476 {
477 /* now find the exported program and call it */
478 struct svc_callout *s;
479 struct svc_req r;
480 enum auth_stat why;
481 rpcvers_t low_vers;
482 rpcvers_t high_vers;
483 int prog_found;
484
485 r.rq_clntcred = &(cred_area[2 * MAX_AUTH_BYTES]);
486 r.rq_xprt = xprt;
487 r.rq_prog = msg.rm_call.cb_prog;
488 r.rq_vers = msg.rm_call.cb_vers;
489 r.rq_proc = msg.rm_call.cb_proc;
490 r.rq_cred = msg.rm_call.cb_cred;
491
492 /* first authenticate the message */
493 /* Check for null flavor and bypass these calls if possible */
494
495 if (msg.rm_call.cb_cred.oa_flavor == AUTH_NULL)
496 {
497 r.rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
498 r.rq_xprt->xp_verf.oa_length = 0;
499 }
500 else if ((why = _authenticate (&r, &msg)) != AUTH_OK)
501 {
502 svcerr_auth (xprt, why);
503 goto call_done;
504 }
505
506 /* now match message with a registered service */
507 prog_found = FALSE;
508 low_vers = 0 - 1;
509 high_vers = 0;
510
511 for (s = svc_head; s != NULL_SVC; s = s->sc_next)
512 {
513 if (s->sc_prog == r.rq_prog)
514 {
515 if (s->sc_vers == r.rq_vers)
516 {
517 (*s->sc_dispatch) (&r, xprt);
518 goto call_done;
519 }
520 /* found correct version */
521 prog_found = TRUE;
522 if (s->sc_vers < low_vers)
523 low_vers = s->sc_vers;
524 if (s->sc_vers > high_vers)
525 high_vers = s->sc_vers;
526 }
527 /* found correct program */
528 }
529 /* if we got here, the program or version
530 is not served ... */
531 if (prog_found)
532 svcerr_progvers (xprt, low_vers, high_vers);
533 else
534 svcerr_noprog (xprt);
535 /* Fall through to ... */
536 }
537 call_done:
538 if ((stat = SVC_STAT (xprt)) == XPRT_DIED)
539 {
540 SVC_DESTROY (xprt);
541 break;
542 }
543 }
544 while (stat == XPRT_MOREREQS);
545}
546libc_hidden_nolink_sunrpc (svc_getreq_common, GLIBC_2_2)
547
548/* If there are no file descriptors available, then accept will fail.
549 We want to delay here so the connection request can be dequeued;
550 otherwise we can bounce between polling and accepting, never giving the
551 request a chance to dequeue and eating an enormous amount of cpu time
552 in svc_run if we're polling on many file descriptors. */
553void
554__svc_accept_failed (void)
555{
556 if (errno == EMFILE)
557 {
558 struct timespec ts = { .tv_sec = 0, .tv_nsec = 50000000 };
559 __nanosleep (&ts, NULL);
560 }
561}
562
563
564void
565__rpc_thread_svc_cleanup (void)
566{
567 struct svc_callout *svcp;
568
569 while ((svcp = svc_head) != NULL)
570 svc_unregister (svcp->sc_prog, svcp->sc_vers);
571}
572