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. Neither the name of the University 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.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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
29 * @(#)rcmd.c 8.3 (Berkeley) 3/26/94
30 * $FreeBSD: src/lib/libc/net/rcmd.c,v 1.42 2007/01/09 00:28:02 imp Exp $
33 #include "namespace.h"
34 #include <sys/param.h>
35 #include <sys/socket.h>
38 #include <netinet/in.h>
39 #include <arpa/inet.h>
53 #include <rpcsvc/yp_prot.h>
54 #include <rpcsvc/ypclnt.h>
56 #include <arpa/nameser.h>
57 #include "un-namespace.h"
59 extern int innetgr(const char *, const char *, const char *, const char *);
61 #define max(a, b) ((a > b) ? a : b)
63 int __ivaliduser(FILE *, u_int32_t, const char *, const char *);
64 int __ivaliduser_af(FILE *,const void *, const char *, const char *, int, int);
65 int __ivaliduser_sa(FILE *, const struct sockaddr *, socklen_t, const char *,
67 static int __icheckhost(const struct sockaddr *, socklen_t, const char *);
69 char paddr[NI_MAXHOST];
72 rcmd(char **ahost, int rport, const char *locuser, const char *remuser,
73 const char *cmd, int *fd2p)
75 return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
79 rcmd_af(char **ahost, int rport, const char *locuser, const char *remuser,
80 const char *cmd, int *fd2p, int af)
82 struct addrinfo hints, *res, *ai;
83 struct sockaddr_storage from;
85 sigset_t oldmask, newmask;
87 int s, aport, lport, timo, error;
91 static char canonnamebuf[MAXDNAME]; /* is it proper here? */
93 /* call rcmdsh() with specified remote shell if appropriate. */
94 if (!issetugid() && (p = getenv("RSH"))) {
95 struct servent *sp = getservbyname("shell", "tcp");
97 if (sp && sp->s_port == rport)
98 return (rcmdsh(ahost, rport, locuser, remuser,
102 /* use rsh(1) if non-root and remote port is shell. */
104 struct servent *sp = getservbyname("shell", "tcp");
106 if (sp && sp->s_port == rport)
107 return (rcmdsh(ahost, rport, locuser, remuser,
113 memset(&hints, 0, sizeof(hints));
114 hints.ai_flags = AI_CANONNAME;
115 hints.ai_family = af;
116 hints.ai_socktype = SOCK_STREAM;
117 hints.ai_protocol = 0;
118 snprintf(num, sizeof(num), "%d", ntohs(rport));
119 error = getaddrinfo(*ahost, num, &hints, &res);
121 fprintf(stderr, "rcmd: getaddrinfo: %s\n",
122 gai_strerror(error));
123 if (error == EAI_SYSTEM)
124 fprintf(stderr, "rcmd: getaddrinfo: %s\n",
129 if (res->ai_canonname &&
130 strlen(res->ai_canonname) + 1 < sizeof(canonnamebuf)) {
131 strncpy(canonnamebuf, res->ai_canonname, sizeof(canonnamebuf));
132 *ahost = canonnamebuf;
135 for (ai = res; ai; ai = ai->ai_next)
139 sigemptyset(&newmask);
140 sigaddset(&newmask, SIGURG);
141 _sigprocmask(SIG_BLOCK, (const sigset_t *)&newmask, &oldmask);
142 for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
143 s = rresvport_af(&lport, ai->ai_family);
145 if (errno != EAGAIN && ai->ai_next) {
151 "rcmd: socket: All ports in use\n");
153 fprintf(stderr, "rcmd: socket: %s\n",
156 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
160 _fcntl(s, F_SETOWN, pid);
161 if (_connect(s, ai->ai_addr, ai->ai_addrlen) >= 0)
164 if (errno == EADDRINUSE) {
168 if (errno == ECONNREFUSED)
170 if (ai->ai_next == NULL && (!refused || timo > 16)) {
171 fprintf(stderr, "%s: %s\n", *ahost, strerror(errno));
173 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
180 getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr,
181 sizeof(paddr), NULL, 0, NI_NUMERICHOST);
182 fprintf(stderr, "connect to address %s: ", paddr);
186 if ((ai = ai->ai_next) == NULL) {
187 /* refused && timo <= 16 */
188 struct timespec time_to_sleep, time_remaining;
190 time_to_sleep.tv_sec = timo;
191 time_to_sleep.tv_nsec = 0;
192 _nanosleep(&time_to_sleep, &time_remaining);
198 getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr,
199 sizeof(paddr), NULL, 0, NI_NUMERICHOST);
200 fprintf(stderr, "Trying %s...\n", paddr);
208 int s2 = rresvport_af(&lport, ai->ai_family), s3;
209 socklen_t len = ai->ai_addrlen;
215 snprintf(num, sizeof(num), "%d", lport);
216 if (_write(s, num, strlen(num)+1) != strlen(num)+1) {
218 "rcmd: write (setting up stderr): %s\n",
224 if(nfds > FD_SETSIZE) {
225 fprintf(stderr, "rcmd: too many files\n");
234 if (_select(nfds, &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)){
237 "rcmd: select (setting up stderr): %s\n",
241 "select: protocol failure in circuit setup\n");
245 s3 = _accept(s2, (struct sockaddr *)&from, &len);
246 switch (from.ss_family) {
248 aport = ntohs(((struct sockaddr_in *)&from)->sin_port);
252 aport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port);
256 aport = 0; /* error */
260 * XXX careful for ftp bounce attacks. If discovered, shut them
261 * down and check for the real auxiliary channel to connect.
270 "rcmd: accept: %s\n", strerror(errno));
275 if (aport >= IPPORT_RESERVED || aport < IPPORT_RESERVED / 2) {
277 "socket: protocol failure in circuit setup.\n");
281 _write(s, locuser, strlen(locuser)+1);
282 _write(s, remuser, strlen(remuser)+1);
283 _write(s, cmd, strlen(cmd)+1);
284 if (_read(s, &c, 1) != 1) {
286 "rcmd: %s: %s\n", *ahost, strerror(errno));
290 while (_read(s, &c, 1) == 1) {
291 _write(STDERR_FILENO, &c, 1);
297 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
305 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
313 return rresvport_af(port, AF_INET);
317 rresvport_af(int *alport, int family)
320 struct sockaddr_storage ss;
323 memset(&ss, 0, sizeof(ss));
324 ss.ss_family = family;
327 ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in);
328 sport = &((struct sockaddr_in *)&ss)->sin_port;
329 ((struct sockaddr_in *)&ss)->sin_addr.s_addr = INADDR_ANY;
333 ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in6);
334 sport = &((struct sockaddr_in6 *)&ss)->sin6_port;
335 ((struct sockaddr_in6 *)&ss)->sin6_addr = in6addr_any;
339 errno = EAFNOSUPPORT;
343 s = _socket(ss.ss_family, SOCK_STREAM, 0);
346 #if 0 /* compat_exact_traditional_rresvport_semantics */
347 sin.sin_port = htons((u_short)*alport);
348 if (_bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
350 if (errno != EADDRINUSE) {
356 if (bindresvport_sa(s, (struct sockaddr *)&ss) == -1) {
360 *alport = (int)ntohs(*sport);
364 int __check_rhosts_file = 1;
368 ruserok(const char *rhost, int superuser, const char *ruser, const char *luser)
370 struct addrinfo hints, *res, *r;
373 memset(&hints, 0, sizeof(hints));
374 hints.ai_family = PF_UNSPEC;
375 hints.ai_socktype = SOCK_DGRAM; /*dummy*/
376 error = getaddrinfo(rhost, "0", &hints, &res);
380 for (r = res; r; r = r->ai_next) {
381 if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser,
392 * New .rhosts strategy: We are passed an ip address. We spin through
393 * hosts.equiv and .rhosts looking for a match. When the .rhosts only
394 * has ip addresses, we don't have to trust a nameserver. When it
395 * contains hostnames, we spin through the list of addresses the nameserver
396 * gives us and look for a match.
398 * Returns 0 if ok, -1 if not ok.
401 iruserok(unsigned long raddr, int superuser, const char *ruser,
404 struct sockaddr_in sin;
406 memset(&sin, 0, sizeof(sin));
407 sin.sin_family = AF_INET;
408 sin.sin_len = sizeof(struct sockaddr_in);
409 memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
410 return iruserok_sa((struct sockaddr *)&sin, sin.sin_len, superuser,
415 * AF independent extension of iruserok.
417 * Returns 0 if ok, -1 if not ok.
420 iruserok_sa(const void *ra, int rlen, int superuser, const char *ruser,
429 char pbuf[MAXPATHLEN];
430 const struct sockaddr *raddr;
431 struct sockaddr_storage ss;
433 /* avoid alignment issue */
434 if (rlen > sizeof(ss))
436 memcpy(&ss, ra, rlen);
437 raddr = (struct sockaddr *)&ss;
440 hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r");
443 if (__ivaliduser_sa(hostf, raddr, rlen, luser, ruser) == 0) {
449 if (first == 1 && (__check_rhosts_file || superuser)) {
451 if ((pwd = getpwnam(luser)) == NULL)
453 strcpy(pbuf, pwd->pw_dir);
454 strcat(pbuf, "/.rhosts");
457 * Change effective uid while opening .rhosts. If root and
458 * reading an NFS mounted file system, can't read files that
459 * are protected read/write owner only.
462 seteuid(pwd->pw_uid);
463 hostf = fopen(pbuf, "r");
469 * If not a regular file, or is owned by someone other than
470 * user or root or if writeable by anyone but the owner, quit.
473 if (lstat(pbuf, &sbuf) < 0)
474 cp = ".rhosts lstat failed";
475 else if (!S_ISREG(sbuf.st_mode))
476 cp = ".rhosts not regular file";
477 else if (_fstat(fileno(hostf), &sbuf) < 0)
478 cp = ".rhosts fstat failed";
479 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid)
480 cp = "bad .rhosts owner";
481 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH))
482 cp = ".rhosts writeable by other than owner";
483 /* If there were any problems, quit. */
496 * Don't make static, used by lpd(8).
498 * Returns 0 if ok, -1 if not ok.
501 __ivaliduser(FILE *hostf, u_int32_t raddr, const char *luser, const char *ruser)
503 struct sockaddr_in sin;
505 memset(&sin, 0, sizeof(sin));
506 sin.sin_family = AF_INET;
507 sin.sin_len = sizeof(struct sockaddr_in);
508 memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
509 return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len,
514 * Returns 0 if ok, -1 if not ok.
519 __ivaliduser_af(FILE *hostf, const void *raddr, const char *luser,
520 const char *ruser, int af, int len)
522 struct sockaddr *sa = NULL;
523 struct sockaddr_in *sin = NULL;
525 struct sockaddr_in6 *sin6 = NULL;
527 struct sockaddr_storage ss;
529 memset(&ss, 0, sizeof(ss));
532 if (len != sizeof(sin->sin_addr))
534 sin = (struct sockaddr_in *)&ss;
535 sin->sin_family = AF_INET;
536 sin->sin_len = sizeof(struct sockaddr_in);
537 memcpy(&sin->sin_addr, raddr, sizeof(sin->sin_addr));
541 if (len != sizeof(sin6->sin6_addr))
543 /* you will lose scope info */
544 sin6 = (struct sockaddr_in6 *)&ss;
545 sin6->sin6_family = AF_INET6;
546 sin6->sin6_len = sizeof(struct sockaddr_in6);
547 memcpy(&sin6->sin6_addr, raddr, sizeof(sin6->sin6_addr));
554 sa = (struct sockaddr *)&ss;
555 return __ivaliduser_sa(hostf, sa, sa->sa_len, luser, ruser);
559 __ivaliduser_sa(FILE *hostf, const struct sockaddr *raddr, socklen_t salen,
560 const char *luser, const char *ruser)
564 char buf[MAXHOSTNAMELEN + 128]; /* host + login */
565 char hname[MAXHOSTNAMELEN];
566 /* Presumed guilty until proven innocent. */
567 int userok = 0, hostok = 0;
571 if (yp_get_default_domain(&ypdomain))
574 #define ypdomain NULL
576 /* We need to get the damn hostname back for netgroup matching. */
577 if (getnameinfo(raddr, salen, hname, sizeof(hname), NULL, 0,
581 while (fgets(buf, sizeof(buf), hostf)) {
583 /* Skip lines that are too long. */
584 if (strchr(p, '\n') == NULL) {
585 while ((ch = getc(hostf)) != '\n' && ch != EOF);
588 if (*p == '\n' || *p == '#') {
592 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
593 *p = isupper((unsigned char)*p) ? tolower((unsigned char)*p) : *p;
596 if (*p == ' ' || *p == '\t') {
598 while (*p == ' ' || *p == '\t')
601 while (*p != '\n' && *p != ' ' &&
602 *p != '\t' && *p != '\0')
608 * Do +/- and +@/-@ checking. This looks really nasty,
609 * but it matches SunOS's behavior so far as I can tell.
613 if (!buf[1]) { /* '+' matches all hosts */
617 if (buf[1] == '@') /* match a host by netgroup */
618 hostok = hname[0] != '\0' &&
619 innetgr(&buf[2], hname, NULL, ypdomain);
620 else /* match a host by addr */
621 hostok = __icheckhost(raddr, salen,
624 case '-': /* reject '-' hosts and all their users */
626 if (hname[0] == '\0' ||
627 innetgr(&buf[2], hname, NULL, ypdomain))
630 if (__icheckhost(raddr, salen,
635 default: /* if no '+' or '-', do a simple match */
636 hostok = __icheckhost(raddr, salen, buf);
641 if (!*(user+1)) { /* '+' matches all users */
645 if (*(user+1) == '@') /* match a user by netgroup */
646 userok = innetgr(user+2, NULL, ruser, ypdomain);
647 else /* match a user by direct specification */
648 userok = !(strcmp(ruser, user+1));
650 case '-': /* if we matched a hostname, */
651 if (hostok) { /* check for user field rejections */
654 if (*(user+1) == '@') {
655 if (innetgr(user+2, NULL,
659 if (!strcmp(ruser, user+1))
664 default: /* no rejections: try to match the user */
666 userok = !(strcmp(ruser,*user ? user : luser));
669 if (hostok && userok)
676 * Returns "true" if match, 0 if no match.
679 __icheckhost(const struct sockaddr *raddr, socklen_t salen, const char *lhost)
681 struct sockaddr_in sin;
682 struct sockaddr_in6 *sin6;
683 struct addrinfo hints, *res, *r;
685 char h1[NI_MAXHOST], h2[NI_MAXHOST];
687 if (raddr->sa_family == AF_INET6) {
688 sin6 = (struct sockaddr_in6 *)raddr;
689 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
690 memset(&sin, 0, sizeof(sin));
691 sin.sin_family = AF_INET;
692 sin.sin_len = sizeof(struct sockaddr_in);
693 memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[12],
694 sizeof(sin.sin_addr));
695 raddr = (struct sockaddr *)&sin;
701 if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0,
702 NI_NUMERICHOST) != 0)
705 /* Resolve laddr into sockaddr */
706 memset(&hints, 0, sizeof(hints));
707 hints.ai_family = raddr->sa_family;
708 hints.ai_socktype = SOCK_DGRAM; /*XXX dummy*/
710 error = getaddrinfo(lhost, "0", &hints, &res);
714 for (r = res; r ; r = r->ai_next) {
716 if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2),
717 NULL, 0, NI_NUMERICHOST) != 0)
719 if (strcmp(h1, h2) == 0) {