diff options
Diffstat (limited to 'src/lib/libc/net/rcmd.c')
-rw-r--r-- | src/lib/libc/net/rcmd.c | 691 |
1 files changed, 691 insertions, 0 deletions
diff --git a/src/lib/libc/net/rcmd.c b/src/lib/libc/net/rcmd.c new file mode 100644 index 0000000000..bfe8c3ae56 --- /dev/null +++ b/src/lib/libc/net/rcmd.c | |||
@@ -0,0 +1,691 @@ | |||
1 | /* | ||
2 | * Copyright (c) 1995, 1996, 1998 Theo de Raadt. All rights reserved. | ||
3 | * Copyright (c) 1983, 1993, 1994 | ||
4 | * The Regents of the University of California. All rights reserved. | ||
5 | * | ||
6 | * Redistribution and use in source and binary forms, with or without | ||
7 | * modification, are permitted provided that the following conditions | ||
8 | * are met: | ||
9 | * 1. Redistributions of source code must retain the above copyright | ||
10 | * notice, this list of conditions and the following disclaimer. | ||
11 | * 2. Redistributions in binary form must reproduce the above copyright | ||
12 | * notice, this list of conditions and the following disclaimer in the | ||
13 | * documentation and/or other materials provided with the distribution. | ||
14 | * 3. Neither the name of the University nor the names of its contributors | ||
15 | * may be used to endorse or promote products derived from this software | ||
16 | * without specific prior written permission. | ||
17 | * | ||
18 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | ||
19 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
21 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | ||
22 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | ||
23 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | ||
24 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
25 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | ||
26 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | ||
27 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | ||
28 | * SUCH DAMAGE. | ||
29 | */ | ||
30 | |||
31 | #if defined(LIBC_SCCS) && !defined(lint) | ||
32 | static char *rcsid = "$OpenBSD: rcmd.c,v 1.52 2005/03/25 13:24:12 otto Exp $"; | ||
33 | #endif /* LIBC_SCCS and not lint */ | ||
34 | |||
35 | #include <sys/param.h> | ||
36 | #include <sys/socket.h> | ||
37 | #include <sys/stat.h> | ||
38 | |||
39 | #include <netinet/in.h> | ||
40 | #include <arpa/inet.h> | ||
41 | |||
42 | #include <signal.h> | ||
43 | #include <fcntl.h> | ||
44 | #include <netdb.h> | ||
45 | #include <unistd.h> | ||
46 | #include <pwd.h> | ||
47 | #include <errno.h> | ||
48 | #include <stdio.h> | ||
49 | #include <ctype.h> | ||
50 | #include <string.h> | ||
51 | #include <syslog.h> | ||
52 | #include <stdlib.h> | ||
53 | #include <netgroup.h> | ||
54 | |||
55 | int __ivaliduser(FILE *, in_addr_t, const char *, const char *); | ||
56 | int __ivaliduser_sa(FILE *, struct sockaddr *, socklen_t, | ||
57 | const char *, const char *); | ||
58 | static int __icheckhost(struct sockaddr *, socklen_t, const char *); | ||
59 | static char *__gethostloop(struct sockaddr *, socklen_t); | ||
60 | |||
61 | int | ||
62 | rcmd(char **ahost, int rport, const char *locuser, const char *remuser, | ||
63 | const char *cmd, int *fd2p) | ||
64 | { | ||
65 | return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET); | ||
66 | } | ||
67 | |||
68 | int | ||
69 | rcmd_af(char **ahost, int porta, const char *locuser, const char *remuser, | ||
70 | const char *cmd, int *fd2p, int af) | ||
71 | { | ||
72 | static char hbuf[MAXHOSTNAMELEN]; | ||
73 | char pbuf[NI_MAXSERV]; | ||
74 | struct addrinfo hints, *res, *r; | ||
75 | int error; | ||
76 | struct sockaddr_storage from; | ||
77 | fd_set *readsp = NULL; | ||
78 | sigset_t oldmask, mask; | ||
79 | pid_t pid; | ||
80 | int s, lport, timo; | ||
81 | char c, *p; | ||
82 | int refused; | ||
83 | in_port_t rport = porta; | ||
84 | |||
85 | /* call rcmdsh() with specified remote shell if appropriate. */ | ||
86 | if (!issetugid() && (p = getenv("RSH")) && *p) { | ||
87 | struct servent *sp = getservbyname("shell", "tcp"); | ||
88 | |||
89 | if (sp && sp->s_port == rport) | ||
90 | return (rcmdsh(ahost, rport, locuser, remuser, | ||
91 | cmd, p)); | ||
92 | } | ||
93 | |||
94 | /* use rsh(1) if non-root and remote port is shell. */ | ||
95 | if (geteuid()) { | ||
96 | struct servent *sp = getservbyname("shell", "tcp"); | ||
97 | |||
98 | if (sp && sp->s_port == rport) | ||
99 | return (rcmdsh(ahost, rport, locuser, remuser, | ||
100 | cmd, NULL)); | ||
101 | } | ||
102 | |||
103 | pid = getpid(); | ||
104 | snprintf(pbuf, sizeof(pbuf), "%u", ntohs(rport)); | ||
105 | memset(&hints, 0, sizeof(hints)); | ||
106 | hints.ai_family = af; | ||
107 | hints.ai_socktype = SOCK_STREAM; | ||
108 | hints.ai_flags = AI_CANONNAME; | ||
109 | error = getaddrinfo(*ahost, pbuf, &hints, &res); | ||
110 | if (error) { | ||
111 | #if 0 | ||
112 | warnx("%s: %s", *ahost, gai_strerror(error)); | ||
113 | #endif | ||
114 | return (-1); | ||
115 | } | ||
116 | if (res->ai_canonname) { | ||
117 | strlcpy(hbuf, res->ai_canonname, sizeof(hbuf)); | ||
118 | *ahost = hbuf; | ||
119 | } else | ||
120 | ; /*XXX*/ | ||
121 | |||
122 | r = res; | ||
123 | refused = 0; | ||
124 | sigemptyset(&mask); | ||
125 | sigaddset(&mask, SIGURG); | ||
126 | oldmask = sigprocmask(SIG_BLOCK, &mask, &oldmask); | ||
127 | for (timo = 1, lport = IPPORT_RESERVED - 1;;) { | ||
128 | s = rresvport_af(&lport, r->ai_family); | ||
129 | if (s < 0) { | ||
130 | if (errno == EAGAIN) | ||
131 | (void)fprintf(stderr, | ||
132 | "rcmd: socket: All ports in use\n"); | ||
133 | else | ||
134 | (void)fprintf(stderr, "rcmd: socket: %s\n", | ||
135 | strerror(errno)); | ||
136 | if (r->ai_next) { | ||
137 | r = r->ai_next; | ||
138 | continue; | ||
139 | } else { | ||
140 | sigprocmask(SIG_SETMASK, &oldmask, NULL); | ||
141 | freeaddrinfo(res); | ||
142 | return (-1); | ||
143 | } | ||
144 | } | ||
145 | fcntl(s, F_SETOWN, pid); | ||
146 | if (connect(s, r->ai_addr, r->ai_addrlen) >= 0) | ||
147 | break; | ||
148 | (void)close(s); | ||
149 | if (errno == EADDRINUSE) { | ||
150 | lport--; | ||
151 | continue; | ||
152 | } | ||
153 | if (errno == ECONNREFUSED) | ||
154 | refused++; | ||
155 | if (r->ai_next) { | ||
156 | int oerrno = errno; | ||
157 | char hbuf[NI_MAXHOST]; | ||
158 | const int niflags = NI_NUMERICHOST; | ||
159 | |||
160 | hbuf[0] = '\0'; | ||
161 | if (getnameinfo(r->ai_addr, r->ai_addrlen, | ||
162 | hbuf, sizeof(hbuf), NULL, 0, niflags) != 0) | ||
163 | strlcpy(hbuf, "(invalid)", sizeof hbuf); | ||
164 | (void)fprintf(stderr, "connect to address %s: ", hbuf); | ||
165 | errno = oerrno; | ||
166 | perror(0); | ||
167 | r = r->ai_next; | ||
168 | hbuf[0] = '\0'; | ||
169 | if (getnameinfo(r->ai_addr, r->ai_addrlen, | ||
170 | hbuf, sizeof(hbuf), NULL, 0, niflags) != 0) | ||
171 | strlcpy(hbuf, "(invalid)", sizeof hbuf); | ||
172 | (void)fprintf(stderr, "Trying %s...\n", hbuf); | ||
173 | continue; | ||
174 | } | ||
175 | if (refused && timo <= 16) { | ||
176 | (void)sleep(timo); | ||
177 | timo *= 2; | ||
178 | r = res; | ||
179 | refused = 0; | ||
180 | continue; | ||
181 | } | ||
182 | (void)fprintf(stderr, "%s: %s\n", res->ai_canonname, | ||
183 | strerror(errno)); | ||
184 | sigprocmask(SIG_SETMASK, &oldmask, NULL); | ||
185 | freeaddrinfo(res); | ||
186 | return (-1); | ||
187 | } | ||
188 | /* given "af" can be PF_UNSPEC, we need the real af for "s" */ | ||
189 | af = r->ai_family; | ||
190 | freeaddrinfo(res); | ||
191 | #if 0 | ||
192 | /* | ||
193 | * try to rresvport() to the same port. This will make rresvport() | ||
194 | * fail it's first bind, resulting in it choosing a random port. | ||
195 | */ | ||
196 | lport--; | ||
197 | #endif | ||
198 | if (fd2p == 0) { | ||
199 | write(s, "", 1); | ||
200 | lport = 0; | ||
201 | } else { | ||
202 | char num[8]; | ||
203 | int s2 = rresvport_af(&lport, af), s3; | ||
204 | socklen_t len = sizeof(from); | ||
205 | int fdssize = howmany(MAX(s, s2)+1, NFDBITS) * sizeof(fd_mask); | ||
206 | |||
207 | if (s2 < 0) | ||
208 | goto bad; | ||
209 | readsp = (fd_set *)malloc(fdssize); | ||
210 | if (readsp == NULL) { | ||
211 | close(s2); | ||
212 | goto bad; | ||
213 | } | ||
214 | listen(s2, 1); | ||
215 | (void)snprintf(num, sizeof(num), "%d", lport); | ||
216 | if (write(s, num, strlen(num)+1) != strlen(num)+1) { | ||
217 | (void)fprintf(stderr, | ||
218 | "rcmd: write (setting up stderr): %s\n", | ||
219 | strerror(errno)); | ||
220 | (void)close(s2); | ||
221 | goto bad; | ||
222 | } | ||
223 | again: | ||
224 | bzero(readsp, fdssize); | ||
225 | FD_SET(s, readsp); | ||
226 | FD_SET(s2, readsp); | ||
227 | errno = 0; | ||
228 | if (select(MAX(s, s2) + 1, readsp, 0, 0, 0) < 1 || | ||
229 | !FD_ISSET(s2, readsp)) { | ||
230 | if (errno != 0) | ||
231 | (void)fprintf(stderr, | ||
232 | "rcmd: select (setting up stderr): %s\n", | ||
233 | strerror(errno)); | ||
234 | else | ||
235 | (void)fprintf(stderr, | ||
236 | "select: protocol failure in circuit setup\n"); | ||
237 | (void)close(s2); | ||
238 | goto bad; | ||
239 | } | ||
240 | s3 = accept(s2, (struct sockaddr *)&from, &len); | ||
241 | if (s3 < 0) { | ||
242 | (void)fprintf(stderr, | ||
243 | "rcmd: accept: %s\n", strerror(errno)); | ||
244 | lport = 0; | ||
245 | close(s2); | ||
246 | goto bad; | ||
247 | } | ||
248 | |||
249 | /* | ||
250 | * XXX careful for ftp bounce attacks. If discovered, shut them | ||
251 | * down and check for the real auxiliary channel to connect. | ||
252 | */ | ||
253 | switch (from.ss_family) { | ||
254 | case AF_INET: | ||
255 | case AF_INET6: | ||
256 | if (getnameinfo((struct sockaddr *)&from, len, | ||
257 | NULL, 0, num, sizeof(num), NI_NUMERICSERV) == 0 && | ||
258 | atoi(num) != 20) { | ||
259 | break; | ||
260 | } | ||
261 | close(s3); | ||
262 | goto again; | ||
263 | default: | ||
264 | break; | ||
265 | } | ||
266 | (void)close(s2); | ||
267 | |||
268 | *fd2p = s3; | ||
269 | switch (from.ss_family) { | ||
270 | case AF_INET: | ||
271 | case AF_INET6: | ||
272 | if (getnameinfo((struct sockaddr *)&from, len, | ||
273 | NULL, 0, num, sizeof(num), NI_NUMERICSERV) != 0 || | ||
274 | (atoi(num) >= IPPORT_RESERVED || | ||
275 | atoi(num) < IPPORT_RESERVED / 2)) { | ||
276 | (void)fprintf(stderr, | ||
277 | "socket: protocol failure in circuit setup.\n"); | ||
278 | goto bad2; | ||
279 | } | ||
280 | break; | ||
281 | default: | ||
282 | break; | ||
283 | } | ||
284 | } | ||
285 | (void)write(s, locuser, strlen(locuser)+1); | ||
286 | (void)write(s, remuser, strlen(remuser)+1); | ||
287 | (void)write(s, cmd, strlen(cmd)+1); | ||
288 | if (read(s, &c, 1) != 1) { | ||
289 | (void)fprintf(stderr, | ||
290 | "rcmd: %s: %s\n", *ahost, strerror(errno)); | ||
291 | goto bad2; | ||
292 | } | ||
293 | if (c != 0) { | ||
294 | while (read(s, &c, 1) == 1) { | ||
295 | (void)write(STDERR_FILENO, &c, 1); | ||
296 | if (c == '\n') | ||
297 | break; | ||
298 | } | ||
299 | goto bad2; | ||
300 | } | ||
301 | sigprocmask(SIG_SETMASK, &oldmask, NULL); | ||
302 | free(readsp); | ||
303 | return (s); | ||
304 | bad2: | ||
305 | if (lport) | ||
306 | (void)close(*fd2p); | ||
307 | bad: | ||
308 | if (readsp) | ||
309 | free(readsp); | ||
310 | (void)close(s); | ||
311 | sigprocmask(SIG_SETMASK, &oldmask, NULL); | ||
312 | return (-1); | ||
313 | } | ||
314 | |||
315 | int __check_rhosts_file = 1; | ||
316 | char *__rcmd_errstr; | ||
317 | |||
318 | int | ||
319 | ruserok(const char *rhost, int superuser, const char *ruser, const char *luser) | ||
320 | { | ||
321 | struct addrinfo hints, *res, *r; | ||
322 | int error; | ||
323 | |||
324 | memset(&hints, 0, sizeof(hints)); | ||
325 | hints.ai_family = PF_UNSPEC; | ||
326 | hints.ai_socktype = SOCK_DGRAM; /*dummy*/ | ||
327 | error = getaddrinfo(rhost, "0", &hints, &res); | ||
328 | if (error) | ||
329 | return (-1); | ||
330 | |||
331 | for (r = res; r; r = r->ai_next) { | ||
332 | if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser, | ||
333 | luser) == 0) { | ||
334 | freeaddrinfo(res); | ||
335 | return (0); | ||
336 | } | ||
337 | } | ||
338 | freeaddrinfo(res); | ||
339 | return (-1); | ||
340 | } | ||
341 | |||
342 | /* | ||
343 | * New .rhosts strategy: We are passed an ip address. We spin through | ||
344 | * hosts.equiv and .rhosts looking for a match. When the .rhosts only | ||
345 | * has ip addresses, we don't have to trust a nameserver. When it | ||
346 | * contains hostnames, we spin through the list of addresses the nameserver | ||
347 | * gives us and look for a match. | ||
348 | * | ||
349 | * Returns 0 if ok, -1 if not ok. | ||
350 | */ | ||
351 | int | ||
352 | iruserok(u_int32_t raddr, int superuser, const char *ruser, const char *luser) | ||
353 | { | ||
354 | struct sockaddr_in sin; | ||
355 | |||
356 | memset(&sin, 0, sizeof(sin)); | ||
357 | sin.sin_family = AF_INET; | ||
358 | sin.sin_len = sizeof(struct sockaddr_in); | ||
359 | memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr)); | ||
360 | return iruserok_sa(&sin, sizeof(struct sockaddr_in), superuser, ruser, | ||
361 | luser); | ||
362 | } | ||
363 | |||
364 | int | ||
365 | iruserok_sa(const void *raddr, int rlen, int superuser, const char *ruser, | ||
366 | const char *luser) | ||
367 | { | ||
368 | struct sockaddr *sa; | ||
369 | char *cp; | ||
370 | struct stat sbuf; | ||
371 | struct passwd *pwd; | ||
372 | FILE *hostf; | ||
373 | uid_t uid; | ||
374 | int first; | ||
375 | char pbuf[MAXPATHLEN]; | ||
376 | |||
377 | sa = (struct sockaddr *)raddr; | ||
378 | first = 1; | ||
379 | hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r"); | ||
380 | again: | ||
381 | if (hostf) { | ||
382 | if (__ivaliduser_sa(hostf, sa, rlen, luser, ruser) == 0) { | ||
383 | (void)fclose(hostf); | ||
384 | return (0); | ||
385 | } | ||
386 | (void)fclose(hostf); | ||
387 | } | ||
388 | if (first == 1 && (__check_rhosts_file || superuser)) { | ||
389 | first = 0; | ||
390 | if ((pwd = getpwnam(luser)) == NULL) | ||
391 | return (-1); | ||
392 | snprintf(pbuf, sizeof pbuf, "%s/.rhosts", pwd->pw_dir); | ||
393 | |||
394 | /* | ||
395 | * Change effective uid while opening .rhosts. If root and | ||
396 | * reading an NFS mounted file system, can't read files that | ||
397 | * are protected read/write owner only. | ||
398 | */ | ||
399 | uid = geteuid(); | ||
400 | (void)seteuid(pwd->pw_uid); | ||
401 | hostf = fopen(pbuf, "r"); | ||
402 | (void)seteuid(uid); | ||
403 | |||
404 | if (hostf == NULL) | ||
405 | return (-1); | ||
406 | /* | ||
407 | * If not a regular file, or is owned by someone other than | ||
408 | * user or root or if writeable by anyone but the owner, quit. | ||
409 | */ | ||
410 | cp = NULL; | ||
411 | if (lstat(pbuf, &sbuf) < 0) | ||
412 | cp = ".rhosts lstat failed"; | ||
413 | else if (!S_ISREG(sbuf.st_mode)) | ||
414 | cp = ".rhosts not regular file"; | ||
415 | else if (fstat(fileno(hostf), &sbuf) < 0) | ||
416 | cp = ".rhosts fstat failed"; | ||
417 | else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) | ||
418 | cp = "bad .rhosts owner"; | ||
419 | else if (sbuf.st_mode & (S_IWGRP|S_IWOTH)) | ||
420 | cp = ".rhosts writable by other than owner"; | ||
421 | /* If there were any problems, quit. */ | ||
422 | if (cp) { | ||
423 | __rcmd_errstr = cp; | ||
424 | (void)fclose(hostf); | ||
425 | return (-1); | ||
426 | } | ||
427 | goto again; | ||
428 | } | ||
429 | return (-1); | ||
430 | } | ||
431 | |||
432 | /* | ||
433 | * XXX | ||
434 | * Don't make static, used by lpd(8). | ||
435 | * | ||
436 | * Returns 0 if ok, -1 if not ok. | ||
437 | */ | ||
438 | int | ||
439 | __ivaliduser(FILE *hostf, in_addr_t raddrl, const char *luser, | ||
440 | const char *ruser) | ||
441 | { | ||
442 | struct sockaddr_in sin; | ||
443 | |||
444 | memset(&sin, 0, sizeof(sin)); | ||
445 | sin.sin_family = AF_INET; | ||
446 | sin.sin_len = sizeof(struct sockaddr_in); | ||
447 | memcpy(&sin.sin_addr, &raddrl, sizeof(sin.sin_addr)); | ||
448 | return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len, | ||
449 | luser, ruser); | ||
450 | } | ||
451 | |||
452 | int | ||
453 | __ivaliduser_sa(FILE *hostf, struct sockaddr *raddr, socklen_t salen, | ||
454 | const char *luser, const char *ruser) | ||
455 | { | ||
456 | char *user, *p; | ||
457 | char *buf; | ||
458 | const char *auser, *ahost; | ||
459 | int hostok, userok; | ||
460 | char *rhost = (char *)-1; | ||
461 | char domain[MAXHOSTNAMELEN]; | ||
462 | size_t buflen; | ||
463 | |||
464 | getdomainname(domain, sizeof(domain)); | ||
465 | |||
466 | while ((buf = fgetln(hostf, &buflen))) { | ||
467 | p = buf; | ||
468 | if (*p == '#') | ||
469 | continue; | ||
470 | while (p < buf + buflen && *p != '\n' && *p != ' ' && *p != '\t') { | ||
471 | if (!isprint(*p)) | ||
472 | goto bail; | ||
473 | *p = isupper(*p) ? tolower(*p) : *p; | ||
474 | p++; | ||
475 | } | ||
476 | if (p >= buf + buflen) | ||
477 | continue; | ||
478 | if (*p == ' ' || *p == '\t') { | ||
479 | *p++ = '\0'; | ||
480 | while (p < buf + buflen && (*p == ' ' || *p == '\t')) | ||
481 | p++; | ||
482 | if (p >= buf + buflen) | ||
483 | continue; | ||
484 | user = p; | ||
485 | while (p < buf + buflen && *p != '\n' && *p != ' ' && | ||
486 | *p != '\t') { | ||
487 | if (!isprint(*p)) | ||
488 | goto bail; | ||
489 | p++; | ||
490 | } | ||
491 | } else | ||
492 | user = p; | ||
493 | *p = '\0'; | ||
494 | |||
495 | if (p == buf) | ||
496 | continue; | ||
497 | |||
498 | auser = *user ? user : luser; | ||
499 | ahost = buf; | ||
500 | |||
501 | if (strlen(ahost) >= MAXHOSTNAMELEN) | ||
502 | continue; | ||
503 | |||
504 | /* | ||
505 | * innetgr() must lookup a hostname (we do not attempt | ||
506 | * to change the semantics so that netgroups may have | ||
507 | * #.#.#.# addresses in the list.) | ||
508 | */ | ||
509 | if (ahost[0] == '+') | ||
510 | switch (ahost[1]) { | ||
511 | case '\0': | ||
512 | hostok = 1; | ||
513 | break; | ||
514 | case '@': | ||
515 | if (rhost == (char *)-1) | ||
516 | rhost = __gethostloop(raddr, salen); | ||
517 | hostok = 0; | ||
518 | if (rhost) | ||
519 | hostok = innetgr(&ahost[2], rhost, | ||
520 | NULL, domain); | ||
521 | break; | ||
522 | default: | ||
523 | hostok = __icheckhost(raddr, salen, &ahost[1]); | ||
524 | break; | ||
525 | } | ||
526 | else if (ahost[0] == '-') | ||
527 | switch (ahost[1]) { | ||
528 | case '\0': | ||
529 | hostok = -1; | ||
530 | break; | ||
531 | case '@': | ||
532 | if (rhost == (char *)-1) | ||
533 | rhost = __gethostloop(raddr, salen); | ||
534 | hostok = 0; | ||
535 | if (rhost) | ||
536 | hostok = -innetgr(&ahost[2], rhost, | ||
537 | NULL, domain); | ||
538 | break; | ||
539 | default: | ||
540 | hostok = -__icheckhost(raddr, salen, &ahost[1]); | ||
541 | break; | ||
542 | } | ||
543 | else | ||
544 | hostok = __icheckhost(raddr, salen, ahost); | ||
545 | |||
546 | |||
547 | if (auser[0] == '+') | ||
548 | switch (auser[1]) { | ||
549 | case '\0': | ||
550 | userok = 1; | ||
551 | break; | ||
552 | case '@': | ||
553 | userok = innetgr(&auser[2], NULL, ruser, | ||
554 | domain); | ||
555 | break; | ||
556 | default: | ||
557 | userok = strcmp(ruser, &auser[1]) ? 0 : 1; | ||
558 | break; | ||
559 | } | ||
560 | else if (auser[0] == '-') | ||
561 | switch (auser[1]) { | ||
562 | case '\0': | ||
563 | userok = -1; | ||
564 | break; | ||
565 | case '@': | ||
566 | userok = -innetgr(&auser[2], NULL, ruser, | ||
567 | domain); | ||
568 | break; | ||
569 | default: | ||
570 | userok = strcmp(ruser, &auser[1]) ? 0 : -1; | ||
571 | break; | ||
572 | } | ||
573 | else | ||
574 | userok = strcmp(ruser, auser) ? 0 : 1; | ||
575 | |||
576 | /* Check if one component did not match */ | ||
577 | if (hostok == 0 || userok == 0) | ||
578 | continue; | ||
579 | |||
580 | /* Check if we got a forbidden pair */ | ||
581 | if (userok <= -1 || hostok <= -1) | ||
582 | return (-1); | ||
583 | |||
584 | /* Check if we got a valid pair */ | ||
585 | if (hostok >= 1 && userok >= 1) | ||
586 | return (0); | ||
587 | } | ||
588 | bail: | ||
589 | return (-1); | ||
590 | } | ||
591 | |||
592 | /* | ||
593 | * Returns "true" if match, 0 if no match. If we do not find any | ||
594 | * semblance of an A->PTR->A loop, allow a simple #.#.#.# match to work. | ||
595 | */ | ||
596 | static int | ||
597 | __icheckhost(struct sockaddr *raddr, socklen_t salen, const char *lhost) | ||
598 | { | ||
599 | struct addrinfo hints, *res, *r; | ||
600 | char h1[NI_MAXHOST], h2[NI_MAXHOST]; | ||
601 | int error; | ||
602 | const int niflags = NI_NUMERICHOST; | ||
603 | |||
604 | h1[0] = '\0'; | ||
605 | if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0, | ||
606 | niflags) != 0) | ||
607 | return (0); | ||
608 | |||
609 | /* Resolve laddr into sockaddr */ | ||
610 | memset(&hints, 0, sizeof(hints)); | ||
611 | hints.ai_family = raddr->sa_family; | ||
612 | hints.ai_socktype = SOCK_DGRAM; /*dummy*/ | ||
613 | res = NULL; | ||
614 | error = getaddrinfo(lhost, "0", &hints, &res); | ||
615 | if (error) | ||
616 | return (0); | ||
617 | |||
618 | /* | ||
619 | * Try string comparisons between raddr and laddr. | ||
620 | */ | ||
621 | for (r = res; r; r = r->ai_next) { | ||
622 | h2[0] = '\0'; | ||
623 | if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2), | ||
624 | NULL, 0, niflags) != 0) | ||
625 | continue; | ||
626 | if (strcmp(h1, h2) == 0) { | ||
627 | freeaddrinfo(res); | ||
628 | return (1); | ||
629 | } | ||
630 | } | ||
631 | |||
632 | /* No match. */ | ||
633 | freeaddrinfo(res); | ||
634 | return (0); | ||
635 | } | ||
636 | |||
637 | /* | ||
638 | * Return the hostname associated with the supplied address. | ||
639 | * Do a reverse lookup as well for security. If a loop cannot | ||
640 | * be found, pack the result of inet_ntoa() into the string. | ||
641 | */ | ||
642 | static char * | ||
643 | __gethostloop(struct sockaddr *raddr, socklen_t salen) | ||
644 | { | ||
645 | static char remotehost[NI_MAXHOST]; | ||
646 | char h1[NI_MAXHOST], h2[NI_MAXHOST]; | ||
647 | struct addrinfo hints, *res, *r; | ||
648 | int error; | ||
649 | const int niflags = NI_NUMERICHOST; | ||
650 | |||
651 | h1[0] = remotehost[0] = '\0'; | ||
652 | if (getnameinfo(raddr, salen, remotehost, sizeof(remotehost), | ||
653 | NULL, 0, NI_NAMEREQD) != 0) | ||
654 | return (NULL); | ||
655 | if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0, | ||
656 | niflags) != 0) | ||
657 | return (NULL); | ||
658 | |||
659 | /* | ||
660 | * Look up the name and check that the supplied | ||
661 | * address is in the list | ||
662 | */ | ||
663 | memset(&hints, 0, sizeof(hints)); | ||
664 | hints.ai_family = raddr->sa_family; | ||
665 | hints.ai_socktype = SOCK_DGRAM; /*dummy*/ | ||
666 | hints.ai_flags = AI_CANONNAME; | ||
667 | res = NULL; | ||
668 | error = getaddrinfo(remotehost, "0", &hints, &res); | ||
669 | if (error) | ||
670 | return (NULL); | ||
671 | |||
672 | for (r = res; r; r = r->ai_next) { | ||
673 | h2[0] = '\0'; | ||
674 | if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2), | ||
675 | NULL, 0, niflags) != 0) | ||
676 | continue; | ||
677 | if (strcmp(h1, h2) == 0) { | ||
678 | freeaddrinfo(res); | ||
679 | return (remotehost); | ||
680 | } | ||
681 | } | ||
682 | |||
683 | /* | ||
684 | * either the DNS adminstrator has made a configuration | ||
685 | * mistake, or someone has attempted to spoof us | ||
686 | */ | ||
687 | syslog(LOG_NOTICE, "rcmd: address %s not listed for host %s", | ||
688 | h1, res->ai_canonname ? res->ai_canonname : remotehost); | ||
689 | freeaddrinfo(res); | ||
690 | return (NULL); | ||
691 | } | ||