/* * Copyright (c) 1983, 1993, 1994 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)rcmd.c 8.3 (Berkeley) 3/26/94"; #endif /* LIBC_SCCS and not lint */ #include __FBSDID("$FreeBSD$"); #include "namespace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef YP #include #include #endif #include #include "un-namespace.h" extern int innetgr( const char *, const char *, const char *, const char * ); #define max(a, b) ((a > b) ? a : b) int __ivaliduser(FILE *, u_int32_t, const char *, const char *); int __ivaliduser_af(FILE *,const void *, const char *, const char *, int, int); int __ivaliduser_sa(FILE *, const struct sockaddr *, socklen_t, const char *, const char *); static int __icheckhost(const struct sockaddr *, socklen_t, const char *); char paddr[NI_MAXHOST]; int rcmd(ahost, rport, locuser, remuser, cmd, fd2p) char **ahost; u_short rport; const char *locuser, *remuser, *cmd; int *fd2p; { return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET); } int rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, af) char **ahost; u_short rport; const char *locuser, *remuser, *cmd; int *fd2p; int af; { struct addrinfo hints, *res, *ai; struct sockaddr_storage from; fd_set reads; sigset_t oldmask, newmask; pid_t pid; int s, aport, lport, timo, error; char c, *p; int refused, nres; char num[8]; static char canonnamebuf[MAXDNAME]; /* is it proper here? */ /* call rcmdsh() with specified remote shell if appropriate. */ if (!issetugid() && (p = getenv("RSH"))) { struct servent *sp = getservbyname("shell", "tcp"); if (sp && sp->s_port == rport) return (rcmdsh(ahost, rport, locuser, remuser, cmd, p)); } /* use rsh(1) if non-root and remote port is shell. */ if (geteuid()) { struct servent *sp = getservbyname("shell", "tcp"); if (sp && sp->s_port == rport) return (rcmdsh(ahost, rport, locuser, remuser, cmd, NULL)); } pid = getpid(); memset(&hints, 0, sizeof(hints)); hints.ai_flags = AI_CANONNAME; hints.ai_family = af; hints.ai_socktype = SOCK_STREAM; hints.ai_protocol = 0; (void)snprintf(num, sizeof(num), "%d", ntohs(rport)); error = getaddrinfo(*ahost, num, &hints, &res); if (error) { fprintf(stderr, "rcmd: getaddrinfo: %s\n", gai_strerror(error)); if (error == EAI_SYSTEM) fprintf(stderr, "rcmd: getaddrinfo: %s\n", strerror(errno)); return (-1); } if (res->ai_canonname && strlen(res->ai_canonname) + 1 < sizeof(canonnamebuf)) { strncpy(canonnamebuf, res->ai_canonname, sizeof(canonnamebuf)); *ahost = canonnamebuf; } nres = 0; for (ai = res; ai; ai = ai->ai_next) nres++; ai = res; refused = 0; sigemptyset(&newmask); sigaddset(&newmask, SIGURG); _sigprocmask(SIG_BLOCK, (const sigset_t *)&newmask, &oldmask); for (timo = 1, lport = IPPORT_RESERVED - 1;;) { s = rresvport_af(&lport, ai->ai_family); if (s < 0) { if (errno != EAGAIN && ai->ai_next) { ai = ai->ai_next; continue; } if (errno == EAGAIN) (void)fprintf(stderr, "rcmd: socket: All ports in use\n"); else (void)fprintf(stderr, "rcmd: socket: %s\n", strerror(errno)); freeaddrinfo(res); _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL); return (-1); } _fcntl(s, F_SETOWN, pid); if (_connect(s, ai->ai_addr, ai->ai_addrlen) >= 0) break; (void)_close(s); if (errno == EADDRINUSE) { lport--; continue; } if (errno == ECONNREFUSED) refused = 1; if (ai->ai_next == NULL && (!refused || timo > 16)) { (void)fprintf(stderr, "%s: %s\n", *ahost, strerror(errno)); freeaddrinfo(res); _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL); return (-1); } if (nres > 1) { int oerrno = errno; getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr, sizeof(paddr), NULL, 0, NI_NUMERICHOST); (void)fprintf(stderr, "connect to address %s: ", paddr); errno = oerrno; perror(0); } if ((ai = ai->ai_next) == NULL) { /* refused && timo <= 16 */ struct timespec time_to_sleep, time_remaining; time_to_sleep.tv_sec = timo; time_to_sleep.tv_nsec = 0; (void)_nanosleep(&time_to_sleep, &time_remaining); timo *= 2; ai = res; refused = 0; } if (nres > 1) { getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr, sizeof(paddr), NULL, 0, NI_NUMERICHOST); fprintf(stderr, "Trying %s...\n", paddr); } } lport--; if (fd2p == 0) { _write(s, "", 1); lport = 0; } else { int s2 = rresvport_af(&lport, ai->ai_family), s3; socklen_t len = ai->ai_addrlen; int nfds; if (s2 < 0) goto bad; _listen(s2, 1); (void)snprintf(num, sizeof(num), "%d", lport); if (_write(s, num, strlen(num)+1) != strlen(num)+1) { (void)fprintf(stderr, "rcmd: write (setting up stderr): %s\n", strerror(errno)); (void)_close(s2); goto bad; } nfds = max(s, s2)+1; if(nfds > FD_SETSIZE) { fprintf(stderr, "rcmd: too many files\n"); (void)_close(s2); goto bad; } again: FD_ZERO(&reads); FD_SET(s, &reads); FD_SET(s2, &reads); errno = 0; if (_select(nfds, &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)){ if (errno != 0) (void)fprintf(stderr, "rcmd: select (setting up stderr): %s\n", strerror(errno)); else (void)fprintf(stderr, "select: protocol failure in circuit setup\n"); (void)_close(s2); goto bad; } s3 = _accept(s2, (struct sockaddr *)&from, &len); switch (from.ss_family) { case AF_INET: aport = ntohs(((struct sockaddr_in *)&from)->sin_port); break; #ifdef INET6 case AF_INET6: aport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port); break; #endif default: aport = 0; /* error */ break; } /* * XXX careful for ftp bounce attacks. If discovered, shut them * down and check for the real auxiliary channel to connect. */ if (aport == 20) { _close(s3); goto again; } (void)_close(s2); if (s3 < 0) { (void)fprintf(stderr, "rcmd: accept: %s\n", strerror(errno)); lport = 0; goto bad; } *fd2p = s3; if (aport >= IPPORT_RESERVED || aport < IPPORT_RESERVED / 2) { (void)fprintf(stderr, "socket: protocol failure in circuit setup.\n"); goto bad2; } } (void)_write(s, locuser, strlen(locuser)+1); (void)_write(s, remuser, strlen(remuser)+1); (void)_write(s, cmd, strlen(cmd)+1); if (_read(s, &c, 1) != 1) { (void)fprintf(stderr, "rcmd: %s: %s\n", *ahost, strerror(errno)); goto bad2; } if (c != 0) { while (_read(s, &c, 1) == 1) { (void)_write(STDERR_FILENO, &c, 1); if (c == '\n') break; } goto bad2; } _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL); freeaddrinfo(res); return (s); bad2: if (lport) (void)_close(*fd2p); bad: (void)_close(s); _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL); freeaddrinfo(res); return (-1); } int rresvport(port) int *port; { return rresvport_af(port, AF_INET); } int rresvport_af(alport, family) int *alport, family; { int s; struct sockaddr_storage ss; u_short *sport; memset(&ss, 0, sizeof(ss)); ss.ss_family = family; switch (family) { case AF_INET: ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in); sport = &((struct sockaddr_in *)&ss)->sin_port; ((struct sockaddr_in *)&ss)->sin_addr.s_addr = INADDR_ANY; break; #ifdef INET6 case AF_INET6: ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in6); sport = &((struct sockaddr_in6 *)&ss)->sin6_port; ((struct sockaddr_in6 *)&ss)->sin6_addr = in6addr_any; break; #endif default: errno = EAFNOSUPPORT; return -1; } s = _socket(ss.ss_family, SOCK_STREAM, 0); if (s < 0) return (-1); #if 0 /* compat_exact_traditional_rresvport_semantics */ sin.sin_port = htons((u_short)*alport); if (_bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0) return (s); if (errno != EADDRINUSE) { (void)_close(s); return (-1); } #endif *sport = 0; if (bindresvport_sa(s, (struct sockaddr *)&ss) == -1) { (void)_close(s); return (-1); } *alport = (int)ntohs(*sport); return (s); } int __check_rhosts_file = 1; char *__rcmd_errstr; int ruserok(rhost, superuser, ruser, luser) const char *rhost, *ruser, *luser; int superuser; { struct addrinfo hints, *res, *r; int error; memset(&hints, 0, sizeof(hints)); hints.ai_family = PF_UNSPEC; hints.ai_socktype = SOCK_DGRAM; /*dummy*/ error = getaddrinfo(rhost, "0", &hints, &res); if (error) return (-1); for (r = res; r; r = r->ai_next) { if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser, luser) == 0) { freeaddrinfo(res); return (0); } } freeaddrinfo(res); return (-1); } /* * New .rhosts strategy: We are passed an ip address. We spin through * hosts.equiv and .rhosts looking for a match. When the .rhosts only * has ip addresses, we don't have to trust a nameserver. When it * contains hostnames, we spin through the list of addresses the nameserver * gives us and look for a match. * * Returns 0 if ok, -1 if not ok. */ int iruserok(raddr, superuser, ruser, luser) unsigned long raddr; int superuser; const char *ruser, *luser; { struct sockaddr_in sin; memset(&sin, 0, sizeof(sin)); sin.sin_family = AF_INET; sin.sin_len = sizeof(struct sockaddr_in); memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr)); return iruserok_sa((struct sockaddr *)&sin, sin.sin_len, superuser, ruser, luser); } /* * AF independent extension of iruserok. * * Returns 0 if ok, -1 if not ok. */ int iruserok_sa(ra, rlen, superuser, ruser, luser) const void *ra; int rlen; int superuser; const char *ruser, *luser; { char *cp; struct stat sbuf; struct passwd *pwd; FILE *hostf; uid_t uid; int first; char pbuf[MAXPATHLEN]; const struct sockaddr *raddr; struct sockaddr_storage ss; /* avoid alignment issue */ if (rlen > sizeof(ss)) return(-1); memcpy(&ss, ra, rlen); raddr = (struct sockaddr *)&ss; first = 1; hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r"); again: if (hostf) { if (__ivaliduser_sa(hostf, raddr, rlen, luser, ruser) == 0) { (void)fclose(hostf); return (0); } (void)fclose(hostf); } if (first == 1 && (__check_rhosts_file || superuser)) { first = 0; if ((pwd = getpwnam(luser)) == NULL) return (-1); (void)strcpy(pbuf, pwd->pw_dir); (void)strcat(pbuf, "/.rhosts"); /* * Change effective uid while opening .rhosts. If root and * reading an NFS mounted file system, can't read files that * are protected read/write owner only. */ uid = geteuid(); (void)seteuid(pwd->pw_uid); hostf = fopen(pbuf, "r"); (void)seteuid(uid); if (hostf == NULL) return (-1); /* * If not a regular file, or is owned by someone other than * user or root or if writeable by anyone but the owner, quit. */ cp = NULL; if (lstat(pbuf, &sbuf) < 0) cp = ".rhosts lstat failed"; else if (!S_ISREG(sbuf.st_mode)) cp = ".rhosts not regular file"; else if (_fstat(fileno(hostf), &sbuf) < 0) cp = ".rhosts fstat failed"; else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) cp = "bad .rhosts owner"; else if (sbuf.st_mode & (S_IWGRP|S_IWOTH)) cp = ".rhosts writeable by other than owner"; /* If there were any problems, quit. */ if (cp) { __rcmd_errstr = cp; (void)fclose(hostf); return (-1); } goto again; } return (-1); } /* * XXX * Don't make static, used by lpd(8). * * Returns 0 if ok, -1 if not ok. */ int __ivaliduser(hostf, raddr, luser, ruser) FILE *hostf; u_int32_t raddr; const char *luser, *ruser; { struct sockaddr_in sin; memset(&sin, 0, sizeof(sin)); sin.sin_family = AF_INET; sin.sin_len = sizeof(struct sockaddr_in); memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr)); return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len, luser, ruser); } /* * Returns 0 if ok, -1 if not ok. * * XXX obsolete API. */ int __ivaliduser_af(hostf, raddr, luser, ruser, af, len) FILE *hostf; const void *raddr; const char *luser, *ruser; int af, len; { struct sockaddr *sa = NULL; struct sockaddr_in *sin = NULL; #ifdef INET6 struct sockaddr_in6 *sin6 = NULL; #endif struct sockaddr_storage ss; memset(&ss, 0, sizeof(ss)); switch (af) { case AF_INET: if (len != sizeof(sin->sin_addr)) return -1; sin = (struct sockaddr_in *)&ss; sin->sin_family = AF_INET; sin->sin_len = sizeof(struct sockaddr_in); memcpy(&sin->sin_addr, raddr, sizeof(sin->sin_addr)); break; #ifdef INET6 case AF_INET6: if (len != sizeof(sin6->sin6_addr)) return -1; /* you will lose scope info */ sin6 = (struct sockaddr_in6 *)&ss; sin6->sin6_family = AF_INET6; sin6->sin6_len = sizeof(struct sockaddr_in6); memcpy(&sin6->sin6_addr, raddr, sizeof(sin6->sin6_addr)); break; #endif default: return -1; } sa = (struct sockaddr *)&ss; return __ivaliduser_sa(hostf, sa, sa->sa_len, luser, ruser); } int __ivaliduser_sa(hostf, raddr, salen, luser, ruser) FILE *hostf; const struct sockaddr *raddr; socklen_t salen; const char *luser, *ruser; { char *user, *p; int ch; char buf[MAXHOSTNAMELEN + 128]; /* host + login */ char hname[MAXHOSTNAMELEN]; /* Presumed guilty until proven innocent. */ int userok = 0, hostok = 0; #ifdef YP char *ypdomain; if (yp_get_default_domain(&ypdomain)) ypdomain = NULL; #else #define ypdomain NULL #endif /* We need to get the damn hostname back for netgroup matching. */ if (getnameinfo(raddr, salen, hname, sizeof(hname), NULL, 0, NI_NAMEREQD) != 0) hname[0] = '\0'; while (fgets(buf, sizeof(buf), hostf)) { p = buf; /* Skip lines that are too long. */ if (strchr(p, '\n') == NULL) { while ((ch = getc(hostf)) != '\n' && ch != EOF); continue; } if (*p == '\n' || *p == '#') { /* comment... */ continue; } while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') { *p = isupper((unsigned char)*p) ? tolower((unsigned char)*p) : *p; p++; } if (*p == ' ' || *p == '\t') { *p++ = '\0'; while (*p == ' ' || *p == '\t') p++; user = p; while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') p++; } else user = p; *p = '\0'; /* * Do +/- and +@/-@ checking. This looks really nasty, * but it matches SunOS's behavior so far as I can tell. */ switch(buf[0]) { case '+': if (!buf[1]) { /* '+' matches all hosts */ hostok = 1; break; } if (buf[1] == '@') /* match a host by netgroup */ hostok = hname[0] != '\0' && innetgr(&buf[2], hname, NULL, ypdomain); else /* match a host by addr */ hostok = __icheckhost(raddr, salen, (char *)&buf[1]); break; case '-': /* reject '-' hosts and all their users */ if (buf[1] == '@') { if (hname[0] == '\0' || innetgr(&buf[2], hname, NULL, ypdomain)) return(-1); } else { if (__icheckhost(raddr, salen, (char *)&buf[1])) return(-1); } break; default: /* if no '+' or '-', do a simple match */ hostok = __icheckhost(raddr, salen, buf); break; } switch(*user) { case '+': if (!*(user+1)) { /* '+' matches all users */ userok = 1; break; } if (*(user+1) == '@') /* match a user by netgroup */ userok = innetgr(user+2, NULL, ruser, ypdomain); else /* match a user by direct specification */ userok = !(strcmp(ruser, user+1)); break; case '-': /* if we matched a hostname, */ if (hostok) { /* check for user field rejections */ if (!*(user+1)) return(-1); if (*(user+1) == '@') { if (innetgr(user+2, NULL, ruser, ypdomain)) return(-1); } else { if (!strcmp(ruser, user+1)) return(-1); } } break; default: /* no rejections: try to match the user */ if (hostok) userok = !(strcmp(ruser,*user ? user : luser)); break; } if (hostok && userok) return(0); } return (-1); } /* * Returns "true" if match, 0 if no match. */ static int __icheckhost(raddr, salen, lhost) const struct sockaddr *raddr; socklen_t salen; const char *lhost; { struct sockaddr_in sin; struct sockaddr_in6 *sin6; struct addrinfo hints, *res, *r; int error; char h1[NI_MAXHOST], h2[NI_MAXHOST]; if (raddr->sa_family == AF_INET6) { sin6 = (struct sockaddr_in6 *)raddr; if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) { memset(&sin, 0, sizeof(sin)); sin.sin_family = AF_INET; sin.sin_len = sizeof(struct sockaddr_in); memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[12], sizeof(sin.sin_addr)); raddr = (struct sockaddr *)&sin; salen = sin.sin_len; } } h1[0] = '\0'; if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0, NI_NUMERICHOST) != 0) return (0); /* Resolve laddr into sockaddr */ memset(&hints, 0, sizeof(hints)); hints.ai_family = raddr->sa_family; hints.ai_socktype = SOCK_DGRAM; /*XXX dummy*/ res = NULL; error = getaddrinfo(lhost, "0", &hints, &res); if (error) return (0); for (r = res; r ; r = r->ai_next) { h2[0] = '\0'; if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2), NULL, 0, NI_NUMERICHOST) != 0) continue; if (strcmp(h1, h2) == 0) { freeaddrinfo(res); return (1); } } /* No match. */ freeaddrinfo(res); return (0); }