2 * Copyright (c) 1983, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * $FreeBSD: src/lib/libc/net/rcmd.c,v 1.23.2.7 2002/08/26 16:17:49 jdp Exp $
34 * $DragonFly: src/lib/libc/net/rcmd.c,v 1.5 2005/01/31 22:29:33 dillon Exp $
36 * @(#)rcmd.c 8.3 (Berkeley) 3/26/94
39 #include "namespace.h"
40 #include <sys/param.h>
41 #include <sys/socket.h>
44 #include <netinet/in.h>
45 #include <arpa/inet.h>
59 #include <rpcsvc/yp_prot.h>
60 #include <rpcsvc/ypclnt.h>
62 #include <arpa/nameser.h>
63 #include "un-namespace.h"
65 /* wrapper for KAME-special getnameinfo() */
66 #ifndef NI_WITHSCOPEID
67 #define NI_WITHSCOPEID 0
70 extern int innetgr ( const char *, const char *, const char *, const char * );
72 #define max(a, b) ((a > b) ? a : b)
74 int __ivaliduser (FILE *, u_int32_t, const char *, const char *);
75 int __ivaliduser_af (FILE *,const void *, const char *, const char *,
77 int __ivaliduser_sa (FILE *, const struct sockaddr *, socklen_t,
78 const char *,const char *);
79 static int __icheckhost (const struct sockaddr *, socklen_t,
82 char paddr[NI_MAXHOST];
85 rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
88 const char *locuser, *remuser, *cmd;
91 return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
95 rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, af)
98 const char *locuser, *remuser, *cmd;
102 struct addrinfo hints, *res, *ai;
103 struct sockaddr_storage from;
105 sigset_t oldmask, newmask;
107 int s, aport, lport, timo, error;
111 static char canonnamebuf[MAXDNAME]; /* is it proper here? */
113 /* call rcmdsh() with specified remote shell if appropriate. */
114 if (!issetugid() && (p = getenv("RSH"))) {
115 struct servent *sp = getservbyname("shell", "tcp");
117 if (sp && sp->s_port == rport)
118 return (rcmdsh(ahost, rport, locuser, remuser,
122 /* use rsh(1) if non-root and remote port is shell. */
124 struct servent *sp = getservbyname("shell", "tcp");
126 if (sp && sp->s_port == rport)
127 return (rcmdsh(ahost, rport, locuser, remuser,
133 memset(&hints, 0, sizeof(hints));
134 hints.ai_flags = AI_CANONNAME;
135 hints.ai_family = af;
136 hints.ai_socktype = SOCK_STREAM;
137 hints.ai_protocol = 0;
138 (void)snprintf(num, sizeof(num), "%d", ntohs(rport));
139 error = getaddrinfo(*ahost, num, &hints, &res);
141 fprintf(stderr, "rcmd: getaddrinfo: %s\n",
142 gai_strerror(error));
143 if (error == EAI_SYSTEM)
144 fprintf(stderr, "rcmd: getaddrinfo: %s\n",
149 if (res->ai_canonname
150 && strlen(res->ai_canonname) + 1 < sizeof(canonnamebuf)) {
151 strncpy(canonnamebuf, res->ai_canonname, sizeof(canonnamebuf));
152 *ahost = canonnamebuf;
155 for (ai = res; ai; ai = ai->ai_next)
159 sigemptyset(&newmask);
160 sigaddset(&newmask, SIGURG);
161 _sigprocmask(SIG_BLOCK, (const sigset_t *)&newmask, &oldmask);
162 for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
163 s = rresvport_af(&lport, ai->ai_family);
165 if (errno != EAGAIN && ai->ai_next) {
170 (void)fprintf(stderr,
171 "rcmd: socket: All ports in use\n");
173 (void)fprintf(stderr, "rcmd: socket: %s\n",
176 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
180 _fcntl(s, F_SETOWN, pid);
181 if (_connect(s, ai->ai_addr, ai->ai_addrlen) >= 0)
184 if (errno == EADDRINUSE) {
188 if (errno == ECONNREFUSED)
190 if (ai->ai_next == NULL && (!refused || timo > 16)) {
191 (void)fprintf(stderr, "%s: %s\n",
192 *ahost, strerror(errno));
194 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
201 getnameinfo(ai->ai_addr, ai->ai_addrlen,
202 paddr, sizeof(paddr),
204 NI_NUMERICHOST|NI_WITHSCOPEID);
205 (void)fprintf(stderr, "connect to address %s: ",
210 if ((ai = ai->ai_next) == NULL) {
211 /* refused && timo <= 16 */
212 struct timespec time_to_sleep, time_remaining;
214 time_to_sleep.tv_sec = timo;
215 time_to_sleep.tv_nsec = 0;
216 (void)_nanosleep(&time_to_sleep, &time_remaining);
222 getnameinfo(ai->ai_addr, ai->ai_addrlen,
223 paddr, sizeof(paddr),
225 NI_NUMERICHOST|NI_WITHSCOPEID);
226 fprintf(stderr, "Trying %s...\n", paddr);
235 int s2 = rresvport_af(&lport, ai->ai_family), s3;
236 int len = ai->ai_addrlen;
242 (void)snprintf(num, sizeof(num), "%d", lport);
243 if (_write(s, num, strlen(num)+1) != strlen(num)+1) {
244 (void)fprintf(stderr,
245 "rcmd: write (setting up stderr): %s\n",
251 if(nfds > FD_SETSIZE) {
252 fprintf(stderr, "rcmd: too many files\n");
261 if (_select(nfds, &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)){
263 (void)fprintf(stderr,
264 "rcmd: select (setting up stderr): %s\n",
267 (void)fprintf(stderr,
268 "select: protocol failure in circuit setup\n");
272 s3 = _accept(s2, (struct sockaddr *)&from, &len);
273 switch (from.ss_family) {
275 aport = ntohs(((struct sockaddr_in *)&from)->sin_port);
279 aport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port);
283 aport = 0; /* error */
287 * XXX careful for ftp bounce attacks. If discovered, shut them
288 * down and check for the real auxiliary channel to connect.
296 (void)fprintf(stderr,
297 "rcmd: accept: %s\n", strerror(errno));
302 if (aport >= IPPORT_RESERVED || aport < IPPORT_RESERVED / 2) {
303 (void)fprintf(stderr,
304 "socket: protocol failure in circuit setup.\n");
308 (void)_write(s, locuser, strlen(locuser)+1);
309 (void)_write(s, remuser, strlen(remuser)+1);
310 (void)_write(s, cmd, strlen(cmd)+1);
311 if (_read(s, &c, 1) != 1) {
312 (void)fprintf(stderr,
313 "rcmd: %s: %s\n", *ahost, strerror(errno));
317 while (_read(s, &c, 1) == 1) {
318 (void)_write(STDERR_FILENO, &c, 1);
324 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
332 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
341 return rresvport_af(port, AF_INET);
345 rresvport_af(alport, family)
349 struct sockaddr_storage ss;
352 memset(&ss, 0, sizeof(ss));
353 ss.ss_family = family;
356 ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in);
357 sport = &((struct sockaddr_in *)&ss)->sin_port;
358 ((struct sockaddr_in *)&ss)->sin_addr.s_addr = INADDR_ANY;
362 ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in6);
363 sport = &((struct sockaddr_in6 *)&ss)->sin6_port;
364 ((struct sockaddr_in6 *)&ss)->sin6_addr = in6addr_any;
368 errno = EAFNOSUPPORT;
372 s = _socket(ss.ss_family, SOCK_STREAM, 0);
375 #if 0 /* compat_exact_traditional_rresvport_semantics */
376 sin.sin_port = htons((u_short)*alport);
377 if (_bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
379 if (errno != EADDRINUSE) {
385 if (bindresvport_sa(s, (struct sockaddr *)&ss) == -1) {
389 *alport = (int)ntohs(*sport);
393 int __check_rhosts_file = 1;
397 ruserok(rhost, superuser, ruser, luser)
398 const char *rhost, *ruser, *luser;
401 struct addrinfo hints, *res, *r;
404 memset(&hints, 0, sizeof(hints));
405 hints.ai_family = PF_UNSPEC;
406 hints.ai_socktype = SOCK_DGRAM; /*dummy*/
407 error = getaddrinfo(rhost, "0", &hints, &res);
411 for (r = res; r; r = r->ai_next) {
412 if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser,
423 * New .rhosts strategy: We are passed an ip address. We spin through
424 * hosts.equiv and .rhosts looking for a match. When the .rhosts only
425 * has ip addresses, we don't have to trust a nameserver. When it
426 * contains hostnames, we spin through the list of addresses the nameserver
427 * gives us and look for a match.
429 * Returns 0 if ok, -1 if not ok.
432 iruserok(raddr, superuser, ruser, luser)
435 const char *ruser, *luser;
437 struct sockaddr_in sin;
439 memset(&sin, 0, sizeof(sin));
440 sin.sin_family = AF_INET;
441 sin.sin_len = sizeof(struct sockaddr_in);
442 memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
443 return iruserok_sa((struct sockaddr *)&sin, sin.sin_len, superuser,
448 * AF independent extension of iruserok.
450 * Returns 0 if ok, -1 if not ok.
453 iruserok_sa(ra, rlen, superuser, ruser, luser)
457 const char *ruser, *luser;
465 char pbuf[MAXPATHLEN];
466 const struct sockaddr *raddr;
467 struct sockaddr_storage ss;
469 /* avoid alignment issue */
470 if (rlen > sizeof(ss))
472 memcpy(&ss, ra, rlen);
473 raddr = (struct sockaddr *)&ss;
476 hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r");
479 if (__ivaliduser_sa(hostf, raddr, rlen, luser, ruser) == 0) {
485 if (first == 1 && (__check_rhosts_file || superuser)) {
487 if ((pwd = getpwnam(luser)) == NULL)
489 (void)strcpy(pbuf, pwd->pw_dir);
490 (void)strcat(pbuf, "/.rhosts");
493 * Change effective uid while opening .rhosts. If root and
494 * reading an NFS mounted file system, can't read files that
495 * are protected read/write owner only.
498 (void)seteuid(pwd->pw_uid);
499 hostf = fopen(pbuf, "r");
505 * If not a regular file, or is owned by someone other than
506 * user or root or if writeable by anyone but the owner, quit.
509 if (lstat(pbuf, &sbuf) < 0)
510 cp = ".rhosts lstat failed";
511 else if (!S_ISREG(sbuf.st_mode))
512 cp = ".rhosts not regular file";
513 else if (_fstat(fileno(hostf), &sbuf) < 0)
514 cp = ".rhosts fstat failed";
515 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid)
516 cp = "bad .rhosts owner";
517 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH))
518 cp = ".rhosts writeable by other than owner";
519 /* If there were any problems, quit. */
532 * Don't make static, used by lpd(8).
534 * Returns 0 if ok, -1 if not ok.
537 __ivaliduser(hostf, raddr, luser, ruser)
540 const char *luser, *ruser;
542 struct sockaddr_in sin;
544 memset(&sin, 0, sizeof(sin));
545 sin.sin_family = AF_INET;
546 sin.sin_len = sizeof(struct sockaddr_in);
547 memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
548 return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len,
553 * Returns 0 if ok, -1 if not ok.
558 __ivaliduser_af(hostf, raddr, luser, ruser, af, len)
561 const char *luser, *ruser;
564 struct sockaddr *sa = NULL;
565 struct sockaddr_in *sin = NULL;
567 struct sockaddr_in6 *sin6 = NULL;
569 struct sockaddr_storage ss;
571 memset(&ss, 0, sizeof(ss));
574 if (len != sizeof(sin->sin_addr))
576 sin = (struct sockaddr_in *)&ss;
577 sin->sin_family = AF_INET;
578 sin->sin_len = sizeof(struct sockaddr_in);
579 memcpy(&sin->sin_addr, raddr, sizeof(sin->sin_addr));
583 if (len != sizeof(sin6->sin6_addr))
585 /* you will lose scope info */
586 sin6 = (struct sockaddr_in6 *)&ss;
587 sin6->sin6_family = AF_INET6;
588 sin6->sin6_len = sizeof(struct sockaddr_in6);
589 memcpy(&sin6->sin6_addr, raddr, sizeof(sin6->sin6_addr));
596 sa = (struct sockaddr *)&ss;
597 return __ivaliduser_sa(hostf, sa, sa->sa_len, luser, ruser);
601 * Returns 0 if ok, -1 if not ok.
604 __ivaliduser_sa(hostf, raddr, salen, luser, ruser)
606 const struct sockaddr *raddr;
608 const char *luser, *ruser;
612 char buf[MAXHOSTNAMELEN + 128]; /* host + login */
613 char hname[MAXHOSTNAMELEN];
614 /* Presumed guilty until proven innocent. */
615 int userok = 0, hostok = 0;
620 if (yp_get_default_domain(&ypdomain))
623 #define ypdomain NULL
625 /* We need to get the damn hostname back for netgroup matching. */
626 if (getnameinfo(raddr, salen, hname, sizeof(hname), NULL, 0,
630 while (fgets(buf, sizeof(buf), hostf)) {
632 /* Skip lines that are too long. */
633 if (strchr(p, '\n') == NULL) {
634 while ((ch = getc(hostf)) != '\n' && ch != EOF);
637 if (*p == '\n' || *p == '#') {
641 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
642 *p = isupper((unsigned char)*p) ? tolower((unsigned char)*p) : *p;
645 if (*p == ' ' || *p == '\t') {
647 while (*p == ' ' || *p == '\t')
650 while (*p != '\n' && *p != ' ' &&
651 *p != '\t' && *p != '\0')
657 * Do +/- and +@/-@ checking. This looks really nasty,
658 * but it matches SunOS's behavior so far as I can tell.
662 if (!buf[1]) { /* '+' matches all hosts */
666 if (buf[1] == '@') /* match a host by netgroup */
667 hostok = hname[0] != '\0' &&
668 innetgr(&buf[2], hname, NULL, ypdomain);
669 else /* match a host by addr */
670 hostok = __icheckhost(raddr, salen,
673 case '-': /* reject '-' hosts and all their users */
675 if (hname[0] == '\0' ||
676 innetgr(&buf[2], hname, NULL, ypdomain))
679 if (__icheckhost(raddr, salen,
684 default: /* if no '+' or '-', do a simple match */
685 hostok = __icheckhost(raddr, salen, buf);
690 if (!*(user+1)) { /* '+' matches all users */
694 if (*(user+1) == '@') /* match a user by netgroup */
695 userok = innetgr(user+2, NULL, ruser, ypdomain);
696 else /* match a user by direct specification */
697 userok = !(strcmp(ruser, user+1));
699 case '-': /* if we matched a hostname, */
700 if (hostok) { /* check for user field rejections */
703 if (*(user+1) == '@') {
704 if (innetgr(user+2, NULL,
708 if (!strcmp(ruser, user+1))
713 default: /* no rejections: try to match the user */
715 userok = !(strcmp(ruser,*user ? user : luser));
718 if (hostok && userok)
725 * Returns "true" if match, 0 if no match.
727 * NI_WITHSCOPEID is useful for comparing sin6_scope_id portion
731 __icheckhost(raddr, salen, lhost)
732 const struct sockaddr *raddr;
736 struct sockaddr_in sin;
737 struct sockaddr_in6 *sin6;
738 struct addrinfo hints, *res, *r;
740 char h1[NI_MAXHOST], h2[NI_MAXHOST];
742 if (raddr->sa_family == AF_INET6) {
743 sin6 = (struct sockaddr_in6 *)raddr;
744 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
745 memset(&sin, 0, sizeof(sin));
746 sin.sin_family = AF_INET;
747 sin.sin_len = sizeof(struct sockaddr_in);
748 memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[12],
749 sizeof(sin.sin_addr));
750 raddr = (struct sockaddr *)&sin;
756 if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0,
757 NI_NUMERICHOST | NI_WITHSCOPEID) != 0)
760 /* Resolve laddr into sockaddr */
761 memset(&hints, 0, sizeof(hints));
762 hints.ai_family = raddr->sa_family;
763 hints.ai_socktype = SOCK_DGRAM; /*XXX dummy*/
765 error = getaddrinfo(lhost, "0", &hints, &res);
769 for (r = res; r ; r = r->ai_next) {
771 if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2),
772 NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID) != 0)
774 if (strcmp(h1, h2) == 0) {