1/*
2 * Copyright (C) 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29/*
30 * Copyright (c) 1983, 1993, 1994
31 * The Regents of the University of California. All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 * notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 * notice, this list of conditions and the following disclaimer in the
40 * documentation and/or other materials provided with the distribution.
41 * 4. Neither the name of the University nor the names of its contributors
42 * may be used to endorse or promote products derived from this software
43 * without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55 * SUCH DAMAGE.
56 */
57
58#include <sys/param.h>
59#include <sys/poll.h>
60#include <sys/socket.h>
61#include <sys/stat.h>
62
63#include <netinet/in.h>
64#include <arpa/inet.h>
65
66#include <alloca.h>
67#include <signal.h>
68#include <fcntl.h>
69#include <netdb.h>
70#include <unistd.h>
71#include <pwd.h>
72#include <errno.h>
73#include <stdio.h>
74#include <stdio_ext.h>
75#include <ctype.h>
76#include <string.h>
77#include <libintl.h>
78#include <stdlib.h>
79#include <wchar.h>
80#include <sys/uio.h>
81#include <sigsetops.h>
82#include <shlib-compat.h>
83#include <set-freeres.h>
84
85
86int __ivaliduser (FILE *, uint32_t, const char *, const char *);
87static int __validuser2_sa (FILE *, struct sockaddr *, size_t,
88 const char *, const char *, const char *);
89static int ruserok2_sa (struct sockaddr *ra, size_t ralen,
90 int superuser, const char *ruser,
91 const char *luser, const char *rhost);
92static int ruserok_sa (struct sockaddr *ra, size_t ralen,
93 int superuser, const char *ruser,
94 const char *luser);
95int iruserok_af (const void *raddr, int superuser, const char *ruser,
96 const char *luser, sa_family_t af);
97int iruserok (uint32_t raddr, int superuser, const char *ruser,
98 const char *luser);
99
100libc_hidden_proto (iruserok_af)
101
102static char *ahostbuf;
103
104int
105rcmd_af (char **ahost, u_short rport, const char *locuser, const char *remuser,
106 const char *cmd, int *fd2p, sa_family_t af)
107{
108 char paddr[INET6_ADDRSTRLEN];
109 struct addrinfo hints, *res, *ai;
110 union
111 {
112 struct sockaddr sa;
113 struct sockaddr_storage ss;
114 struct sockaddr_in sin;
115 struct sockaddr_in6 sin6;
116 } from;
117 struct pollfd pfd[2];
118 sigset_t mask, omask;
119
120 pid_t pid;
121 int s, lport, timo, error;
122 char c;
123 int refused;
124 char num[8];
125 ssize_t n;
126
127 if (af != AF_INET && af != AF_INET6 && af != AF_UNSPEC)
128 {
129 __set_errno (EAFNOSUPPORT);
130 return -1;
131 }
132
133 pid = __getpid();
134
135 memset(&hints, '\0', sizeof(hints));
136 hints.ai_flags = AI_CANONNAME;
137 hints.ai_family = af;
138 hints.ai_socktype = SOCK_STREAM;
139 (void)__snprintf(num, sizeof(num), "%d", ntohs(rport));
140 error = getaddrinfo(*ahost, num, &hints, &res);
141 if (error) {
142 if (error == EAI_NONAME && *ahost != NULL)
143 __fxprintf(NULL, "%s: Unknown host\n", *ahost);
144 else
145 __fxprintf(NULL, "rcmd: getaddrinfo: %s\n",
146 gai_strerror(error));
147
148 return -1;
149 }
150
151 pfd[0].events = POLLIN;
152 pfd[1].events = POLLIN;
153
154 if (res->ai_canonname){
155 free (ahostbuf);
156 ahostbuf = __strdup (res->ai_canonname);
157 if (ahostbuf == NULL) {
158 freeaddrinfo (res);
159 __fxprintf(NULL, "%s",
160 _("rcmd: Cannot allocate memory\n"));
161 return -1;
162 }
163 *ahost = ahostbuf;
164 } else
165 *ahost = NULL;
166 ai = res;
167 refused = 0;
168 __sigemptyset(&mask);
169 __sigaddset(&mask, SIGURG);
170 __sigprocmask (SIG_BLOCK, &mask, &omask);
171 for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
172 char errbuf[200];
173
174 s = rresvport_af(&lport, ai->ai_family);
175 if (s < 0) {
176 if (errno == EAGAIN)
177 __fxprintf(NULL, "%s", _("\
178rcmd: socket: All ports in use\n"));
179 else
180 __fxprintf(NULL, "rcmd: socket: %m\n");
181
182 __sigprocmask (SIG_SETMASK, &omask, 0);
183 freeaddrinfo(res);
184 return -1;
185 }
186 __fcntl(s, F_SETOWN, pid);
187 if (__connect(s, ai->ai_addr, ai->ai_addrlen) >= 0)
188 break;
189 (void)__close(s);
190 if (errno == EADDRINUSE) {
191 lport--;
192 continue;
193 }
194 if (errno == ECONNREFUSED)
195 refused = 1;
196 if (ai->ai_next != NULL) {
197 int oerrno = errno;
198 char *buf = NULL;
199
200 getnameinfo(ai->ai_addr, ai->ai_addrlen,
201 paddr, sizeof(paddr),
202 NULL, 0,
203 NI_NUMERICHOST);
204
205 if (__asprintf (&buf, _("connect to address %s: "),
206 paddr) >= 0)
207 {
208 __fxprintf(NULL, "%s", buf);
209 free (buf);
210 }
211 __set_errno (oerrno);
212 perror(0);
213 ai = ai->ai_next;
214 getnameinfo(ai->ai_addr, ai->ai_addrlen,
215 paddr, sizeof(paddr),
216 NULL, 0,
217 NI_NUMERICHOST);
218 if (__asprintf (&buf, _("Trying %s...\n"), paddr) >= 0)
219 {
220 __fxprintf (NULL, "%s", buf);
221 free (buf);
222 }
223 continue;
224 }
225 if (refused && timo <= 16) {
226 (void)__sleep(timo);
227 timo *= 2;
228 ai = res;
229 refused = 0;
230 continue;
231 }
232 freeaddrinfo(res);
233 (void)__fxprintf(NULL, "%s: %s\n", *ahost,
234 __strerror_r(errno, errbuf, sizeof (errbuf)));
235 __sigprocmask (SIG_SETMASK, &omask, 0);
236 return -1;
237 }
238 lport--;
239 if (fd2p == 0) {
240 __write(s, "", 1);
241 lport = 0;
242 } else {
243 char num[8];
244 int s2 = rresvport_af(&lport, ai->ai_family), s3;
245 socklen_t len = ai->ai_addrlen;
246
247 if (s2 < 0)
248 goto bad;
249 __listen(s2, 1);
250 (void)__snprintf(num, sizeof(num), "%d", lport);
251 if (__write(s, num, strlen(num)+1) != (ssize_t)strlen(num)+1) {
252 char *buf = NULL;
253
254 if (__asprintf (&buf, _("\
255rcmd: write (setting up stderr): %m\n")) >= 0)
256 {
257 __fxprintf(NULL, "%s", buf);
258 free (buf);
259 }
260 (void)__close(s2);
261 goto bad;
262 }
263 pfd[0].fd = s;
264 pfd[1].fd = s2;
265 __set_errno (0);
266 if (__poll (pfd, 2, -1) < 1 || (pfd[1].revents & POLLIN) == 0){
267 char *buf = NULL;
268
269 if ((errno != 0
270 && __asprintf(&buf, _("\
271rcmd: poll (setting up stderr): %m\n")) >= 0)
272 || (errno == 0
273 && __asprintf(&buf, _("\
274poll: protocol failure in circuit setup\n")) >= 0))
275 {
276 __fxprintf (NULL, "%s", buf);
277 free (buf);
278 }
279 (void)__close(s2);
280 goto bad;
281 }
282 s3 = TEMP_FAILURE_RETRY (accept(s2, &from.sa, &len));
283 switch (from.sa.sa_family) {
284 case AF_INET:
285 rport = ntohs(from.sin.sin_port);
286 break;
287 case AF_INET6:
288 rport = ntohs(from.sin6.sin6_port);
289 break;
290 default:
291 rport = 0;
292 break;
293 }
294 (void)__close(s2);
295 if (s3 < 0) {
296 (void)__fxprintf(NULL, "rcmd: accept: %m\n");
297 lport = 0;
298 goto bad;
299 }
300 *fd2p = s3;
301
302 if (rport >= IPPORT_RESERVED || rport < IPPORT_RESERVED / 2){
303 char *buf = NULL;
304
305 if (__asprintf(&buf, _("\
306socket: protocol failure in circuit setup\n")) >= 0)
307 {
308 __fxprintf (NULL, "%s", buf);
309 free (buf);
310 }
311 goto bad2;
312 }
313 }
314 struct iovec iov[3] =
315 {
316 [0] = { .iov_base = (void *) locuser,
317 .iov_len = strlen (locuser) + 1 },
318 [1] = { .iov_base = (void *) remuser,
319 .iov_len = strlen (remuser) + 1 },
320 [2] = { .iov_base = (void *) cmd,
321 .iov_len = strlen (cmd) + 1 }
322 };
323 (void) TEMP_FAILURE_RETRY (__writev (s, iov, 3));
324 n = TEMP_FAILURE_RETRY (__read(s, &c, 1));
325 if (n != 1) {
326 char *buf = NULL;
327
328 if ((n == 0
329 && __asprintf(&buf, _("rcmd: %s: short read"),
330 *ahost) >= 0)
331 || (n != 0
332 && __asprintf(&buf, "rcmd: %s: %m\n", *ahost) >= 0))
333 {
334 __fxprintf (NULL, "%s", buf);
335 free (buf);
336 }
337 goto bad2;
338 }
339 if (c != 0) {
340 while (__read(s, &c, 1) == 1) {
341 (void)__write(STDERR_FILENO, &c, 1);
342 if (c == '\n')
343 break;
344 }
345 goto bad2;
346 }
347 __sigprocmask (SIG_SETMASK, &omask, 0);
348 freeaddrinfo(res);
349 return s;
350bad2:
351 if (lport)
352 (void)__close(*fd2p);
353bad:
354 (void)__close(s);
355 __sigprocmask (SIG_SETMASK, &omask, 0);
356 freeaddrinfo(res);
357 return -1;
358}
359libc_hidden_def (rcmd_af)
360
361int
362rcmd (char **ahost, u_short rport, const char *locuser, const char *remuser,
363 const char *cmd, int *fd2p)
364{
365 return rcmd_af (ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
366}
367
368int
369rresvport_af (int *alport, sa_family_t family)
370{
371 union {
372 struct sockaddr generic;
373 struct sockaddr_in in;
374 struct sockaddr_in6 in6;
375 } ss;
376 int s;
377 size_t len;
378 uint16_t *sport;
379
380 switch(family){
381 case AF_INET:
382 len = sizeof(struct sockaddr_in);
383 sport = &ss.in.sin_port;
384 break;
385 case AF_INET6:
386 len = sizeof(struct sockaddr_in6);
387 sport = &ss.in6.sin6_port;
388 break;
389 default:
390 __set_errno (EAFNOSUPPORT);
391 return -1;
392 }
393 /* NB: No SOCK_CLOEXEC for backwards compatibility. */
394 s = __socket(family, SOCK_STREAM, 0);
395 if (s < 0)
396 return -1;
397
398 memset (&ss, '\0', sizeof(ss));
399#ifdef SALEN
400 ss.generic.__ss_len = len;
401#endif
402 ss.generic.sa_family = family;
403
404 /* Ignore invalid values. */
405 if (*alport < IPPORT_RESERVED / 2)
406 *alport = IPPORT_RESERVED / 2;
407 else if (*alport >= IPPORT_RESERVED)
408 *alport = IPPORT_RESERVED - 1;
409
410 int start = *alport;
411 do {
412 *sport = htons((uint16_t) *alport);
413 if (__bind(s, &ss.generic, len) >= 0)
414 return s;
415 if (errno != EADDRINUSE) {
416 (void)__close(s);
417 return -1;
418 }
419 if ((*alport)-- == IPPORT_RESERVED/2)
420 *alport = IPPORT_RESERVED - 1;
421 } while (*alport != start);
422 (void)__close(s);
423 __set_errno (EAGAIN);
424 return -1;
425}
426libc_hidden_def (rresvport_af)
427
428int
429rresvport (int *alport)
430{
431 return rresvport_af(alport, AF_INET);
432}
433
434int __check_rhosts_file = 1;
435char *__rcmd_errstr;
436
437int
438ruserok_af (const char *rhost, int superuser, const char *ruser,
439 const char *luser, sa_family_t af)
440{
441 struct addrinfo hints, *res, *res0;
442 int gai;
443 int ret;
444
445 memset (&hints, '\0', sizeof(hints));
446 hints.ai_family = af;
447 gai = getaddrinfo(rhost, NULL, &hints, &res0);
448 if (gai)
449 return -1;
450 ret = -1;
451 for (res=res0; res; res=res->ai_next)
452 if (ruserok2_sa(res->ai_addr, res->ai_addrlen,
453 superuser, ruser, luser, rhost) == 0){
454 ret = 0;
455 break;
456 }
457 freeaddrinfo(res0);
458 return (ret);
459}
460libc_hidden_def (ruserok_af)
461
462int
463ruserok (const char *rhost, int superuser, const char *ruser,
464 const char *luser)
465{
466 return ruserok_af(rhost, superuser, ruser, luser, AF_INET);
467}
468
469/* Extremely paranoid file open function. */
470static FILE *
471iruserfopen (const char *file, uid_t okuser)
472{
473 struct __stat64_t64 st;
474 char *cp = NULL;
475 FILE *res = NULL;
476
477 /* If not a regular file, if owned by someone other than user or
478 root, if writeable by anyone but the owner, or if hardlinked
479 anywhere, quit. */
480 if (__lstat64_time64 (file, &st))
481 cp = _("lstat failed");
482 else if (!S_ISREG (st.st_mode))
483 cp = _("not regular file");
484 else
485 {
486 res = fopen (file, "rce");
487 if (!res)
488 cp = _("cannot open");
489 else if (__fstat64_time64 (fileno (res), &st) < 0)
490 cp = _("fstat failed");
491 else if (st.st_uid && st.st_uid != okuser)
492 cp = _("bad owner");
493 else if (st.st_mode & (S_IWGRP|S_IWOTH))
494 cp = _("writeable by other than owner");
495 else if (st.st_nlink > 1)
496 cp = _("hard linked somewhere");
497 }
498
499 /* If there were any problems, quit. */
500 if (cp != NULL)
501 {
502 __rcmd_errstr = cp;
503 if (res)
504 fclose (res);
505 return NULL;
506 }
507
508 /* No threads use this stream. */
509 __fsetlocking (res, FSETLOCKING_BYCALLER);
510
511 return res;
512}
513
514/*
515 * New .rhosts strategy: We are passed an ip address. We spin through
516 * hosts.equiv and .rhosts looking for a match. When the .rhosts only
517 * has ip addresses, we don't have to trust a nameserver. When it
518 * contains hostnames, we spin through the list of addresses the nameserver
519 * gives us and look for a match.
520 *
521 * Returns 0 if ok, -1 if not ok.
522 */
523static int
524ruserok2_sa (struct sockaddr *ra, size_t ralen, int superuser,
525 const char *ruser, const char *luser, const char *rhost)
526{
527 FILE *hostf = NULL;
528 int isbad = -1;
529
530 if (!superuser)
531 hostf = iruserfopen (_PATH_HEQUIV, 0);
532
533 if (hostf)
534 {
535 isbad = __validuser2_sa (hostf, ra, ralen, luser, ruser, rhost);
536 fclose (hostf);
537
538 if (!isbad)
539 return 0;
540 }
541
542 if (__check_rhosts_file || superuser)
543 {
544 char *pbuf;
545 struct passwd pwdbuf, *pwd;
546 size_t dirlen;
547 size_t buflen = __sysconf (_SC_GETPW_R_SIZE_MAX);
548 char *buffer = __alloca (buflen);
549 uid_t uid;
550
551 if (__getpwnam_r (luser, &pwdbuf, buffer, buflen, &pwd) != 0
552 || pwd == NULL)
553 return -1;
554
555 dirlen = strlen (pwd->pw_dir);
556 pbuf = alloca (dirlen + sizeof "/.rhosts");
557 __mempcpy (__mempcpy (pbuf, pwd->pw_dir, dirlen),
558 "/.rhosts", sizeof "/.rhosts");
559
560 /* Change effective uid while reading .rhosts. If root and
561 reading an NFS mounted file system, can't read files that
562 are protected read/write owner only. */
563 uid = __geteuid ();
564 if (seteuid (pwd->pw_uid) < 0)
565 return -1;
566
567 hostf = iruserfopen (pbuf, pwd->pw_uid);
568
569 if (hostf != NULL)
570 {
571 isbad = __validuser2_sa (hostf, ra, ralen, luser, ruser, rhost);
572 fclose (hostf);
573 }
574
575 if (seteuid (uid) < 0)
576 return -1;
577 return isbad;
578 }
579 return -1;
580}
581/*
582 * ruserok_sa() is now discussed on ipng, so
583 * currently disabled for external use
584 */
585static int
586ruserok_sa (struct sockaddr *ra, size_t ralen, int superuser,
587 const char *ruser, const char *luser)
588{
589 return ruserok2_sa(ra, ralen, superuser, ruser, luser, "-");
590}
591
592/* This is the exported version. */
593int
594iruserok_af (const void *raddr, int superuser, const char *ruser,
595 const char *luser, sa_family_t af)
596{
597 union {
598 struct sockaddr generic;
599 struct sockaddr_in in;
600 struct sockaddr_in6 in6;
601 } ra;
602 size_t ralen;
603
604 memset (&ra, '\0', sizeof(ra));
605 switch (af){
606 case AF_INET:
607 ra.in.sin_family = AF_INET;
608 memcpy (&ra.in.sin_addr, raddr, sizeof(struct in_addr));
609 ralen = sizeof(struct sockaddr_in);
610 break;
611 case AF_INET6:
612 ra.in6.sin6_family = AF_INET6;
613 memcpy (&ra.in6.sin6_addr, raddr, sizeof(struct in6_addr));
614 ralen = sizeof(struct sockaddr_in6);
615 break;
616 default:
617 return 0;
618 }
619 return ruserok_sa (&ra.generic, ralen, superuser, ruser, luser);
620}
621libc_hidden_def (iruserok_af)
622
623int
624iruserok (uint32_t raddr, int superuser, const char *ruser, const char *luser)
625{
626 return iruserok_af (&raddr, superuser, ruser, luser, AF_INET);
627}
628
629#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_37)
630/* Previously used by lpd. Current lpd versions have their own copy. */
631int attribute_compat_text_section
632__ivaliduser (FILE *hostf, uint32_t raddr, const char *luser,
633 const char *ruser)
634{
635 struct sockaddr_in ra;
636 memset(&ra, '\0', sizeof(ra));
637 ra.sin_family = AF_INET;
638 ra.sin_addr.s_addr = raddr;
639 return __validuser2_sa(hostf, (struct sockaddr *)&ra, sizeof(ra),
640 luser, ruser, "-");
641}
642compat_symbol (libc, __ivaliduser, __ivaliduser, GLIBC_2_0);
643#endif
644
645/* Returns 1 on positive match, 0 on no match, -1 on negative match. */
646static int
647__checkhost_sa (struct sockaddr *ra, size_t ralen, char *lhost,
648 const char *rhost)
649{
650 struct addrinfo hints, *res0, *res;
651 char raddr[INET6_ADDRSTRLEN];
652 int match;
653 int negate=1; /* Multiply return with this to get -1 instead of 1 */
654
655 /* Check nis netgroup. */
656 if (strncmp ("+@", lhost, 2) == 0)
657 return innetgr (&lhost[2], rhost, NULL, NULL);
658
659 if (strncmp ("-@", lhost, 2) == 0)
660 return -innetgr (&lhost[2], rhost, NULL, NULL);
661
662 /* -host */
663 if (strncmp ("-", lhost,1) == 0) {
664 negate = -1;
665 lhost++;
666 } else if (strcmp ("+",lhost) == 0) {
667 return 1; /* asking for trouble, but ok.. */
668 }
669
670 /* Try for raw ip address first. */
671 /* XXX */
672 if (getnameinfo(ra, ralen,
673 raddr, sizeof(raddr), NULL, 0,
674 NI_NUMERICHOST) == 0
675 && strcmp(raddr, lhost) == 0)
676 return negate;
677
678 /* Better be a hostname. */
679 match = 0;
680 memset(&hints, '\0', sizeof(hints));
681 hints.ai_family = ra->sa_family;
682 if (getaddrinfo(lhost, NULL, &hints, &res0) == 0){
683 /* Spin through ip addresses. */
684 for (res = res0; res; res = res->ai_next)
685 {
686 if (res->ai_family == ra->sa_family
687 && !memcmp(res->ai_addr, ra, res->ai_addrlen))
688 {
689 match = 1;
690 break;
691 }
692 }
693 freeaddrinfo (res0);
694 }
695 return negate * match;
696}
697
698/* Returns 1 on positive match, 0 on no match, -1 on negative match. */
699static int
700__icheckuser (const char *luser, const char *ruser)
701{
702 /*
703 luser is user entry from .rhosts/hosts.equiv file
704 ruser is user id on remote host
705 */
706
707 /* [-+]@netgroup */
708 if (strncmp ("+@", luser, 2) == 0)
709 return innetgr (&luser[2], NULL, ruser, NULL);
710
711 if (strncmp ("-@", luser,2) == 0)
712 return -innetgr (&luser[2], NULL, ruser, NULL);
713
714 /* -user */
715 if (strncmp ("-", luser, 1) == 0)
716 return -(strcmp (&luser[1], ruser) == 0);
717
718 /* + */
719 if (strcmp ("+", luser) == 0)
720 return 1;
721
722 /* simple string match */
723 return strcmp (ruser, luser) == 0;
724}
725
726/*
727 * Returns 1 for blank lines (or only comment lines) and 0 otherwise
728 */
729static int
730__isempty (char *p)
731{
732 while (*p && isspace (*p)) {
733 ++p;
734 }
735
736 return (*p == '\0' || *p == '#') ? 1 : 0 ;
737}
738
739/*
740 * Returns 0 if positive match, -1 if _not_ ok.
741 */
742static int
743__validuser2_sa (FILE *hostf, struct sockaddr *ra, size_t ralen,
744 const char *luser, const char *ruser, const char *rhost)
745{
746 const char *user;
747 char *p;
748 int hcheck, ucheck;
749 char *buf = NULL;
750 size_t bufsize = 0;
751 int retval = -1;
752
753 while (__getline (&buf, &bufsize, hostf) > 0) {
754 buf[bufsize - 1] = '\0'; /* Make sure it's terminated. */
755 p = buf;
756
757 /* Skip empty or comment lines */
758 if (__isempty (p)) {
759 continue;
760 }
761
762 for (;*p && !isspace(*p); ++p) {
763 *p = _tolower (*p);
764 }
765
766 /* Next we want to find the permitted name for the remote user. */
767 if (*p == ' ' || *p == '\t') {
768 /* <nul> terminate hostname and skip spaces */
769 for (*p++='\0'; *p && isspace (*p); ++p);
770
771 user = p; /* this is the user's name */
772 while (*p && !isspace (*p))
773 ++p; /* find end of user's name */
774 } else
775 user = p;
776
777 *p = '\0'; /* <nul> terminate username (+host?) */
778
779 /* buf -> host(?) ; user -> username(?) */
780 if (*buf == '\0')
781 break;
782 if (*user == '\0')
783 user = luser;
784
785 /* First check the user part. In a naive implementation we
786 would check the host part first, then the user. However,
787 if we check the user first and reject the entry we will
788 have saved doing any host lookups to normalize the comparison
789 and that likely saves several DNS queries. Therefore we
790 check the user first. */
791 ucheck = __icheckuser (user, ruser);
792
793 /* Either we found the user, or we didn't and this is a
794 negative host check. We must do the negative host lookup
795 in order to preserve the semantics of stopping on this line
796 before processing others. */
797 if (ucheck != 0 || *buf == '-') {
798
799 /* Next check host part. */
800 hcheck = __checkhost_sa (ra, ralen, buf, rhost);
801
802 /* Negative '-host user(?)' match? */
803 if (hcheck < 0)
804 break;
805
806 /* Positive 'host user' match? */
807 if (hcheck > 0 && ucheck > 0) {
808 retval = 0;
809 break;
810 }
811
812 /* Negative 'host -user' match? */
813 if (hcheck > 0 && ucheck < 0)
814 break;
815
816 /* Neither, go on looking for match. */
817 }
818 }
819
820 free (buf);
821
822 return retval;
823}
824
825weak_alias (ahostbuf, __libc_rcmd_freemem_ptr)
826