/* * 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 <sys/param.h> #include <sys/socket.h> #include <sys/stat.h> #include <netinet/in.h> #include <arpa/inet.h> #include <alloca.h> #include <signal.h> #include <fcntl.h> #include <netdb.h> #include <unistd.h> #include <pwd.h> #include <errno.h> #include <stdio.h> #include <ctype.h> #include <string.h> int __ivaliduser __P((FILE *, u_int32_t, const char *, const char *)); static int __icheckhost __P((u_int32_t, char *)) internal_function; int rcmd(ahost, rport, locuser, remuser, cmd, fd2p) char **ahost; u_short rport; const char *locuser, *remuser, *cmd; int *fd2p; { struct hostent hostbuf, *hp; size_t hstbuflen; char *tmphstbuf; struct sockaddr_in sin, from; fd_set reads; int32_t oldmask; pid_t pid; int s, lport, timo; char c; int herr; pid = getpid(); hstbuflen = 1024; tmphstbuf = __alloca (hstbuflen); while (__gethostbyname_r (*ahost, &hostbuf, tmphstbuf, hstbuflen, &hp, &herr) < 0) if (herr != NETDB_INTERNAL || errno != ERANGE) { __set_h_errno (herr); herror(*ahost); return -1; } else { /* Enlarge the buffer. */ hstbuflen *= 2; tmphstbuf = __alloca (hstbuflen); } *ahost = hp->h_name; oldmask = sigblock(sigmask(SIGURG)); for (timo = 1, lport = IPPORT_RESERVED - 1;;) { s = rresvport(&lport); if (s < 0) { if (errno == EAGAIN) (void)fprintf(stderr, _("rcmd: socket: All ports in use\n")); else (void)fprintf(stderr, "rcmd: socket: %m\n"); sigsetmask(oldmask); return -1; } fcntl(s, F_SETOWN, pid); sin.sin_family = hp->h_addrtype; bcopy(hp->h_addr_list[0], &sin.sin_addr, MIN (sizeof (sin.sin_addr), hp->h_length)); sin.sin_port = rport; if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0) break; (void)close(s); if (errno == EADDRINUSE) { lport--; continue; } if (errno == ECONNREFUSED && timo <= 16) { (void)sleep(timo); timo *= 2; continue; } if (hp->h_addr_list[1] != NULL) { int oerrno = errno; (void)fprintf(stderr, _("connect to address %s: "), inet_ntoa(sin.sin_addr)); __set_errno (oerrno); perror(0); hp->h_addr_list++; bcopy(hp->h_addr_list[0], &sin.sin_addr, MIN (sizeof (sin.sin_addr), hp->h_length)); (void)fprintf(stderr, _("Trying %s...\n"), inet_ntoa(sin.sin_addr)); continue; } (void)fprintf(stderr, "%s: %m\n", hp->h_name); sigsetmask(oldmask); return -1; } lport--; if (fd2p == 0) { write(s, "", 1); lport = 0; } else { char num[8]; int s2 = rresvport(&lport), s3; size_t len = sizeof(from); 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): %m\n")); (void)close(s2); goto bad; } FD_ZERO(&reads); FD_SET(s, &reads); FD_SET(s2, &reads); __set_errno (0); if (select(1 + (s > s2 ? s : s2), &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)) { if (errno != 0) (void)fprintf(stderr, _("rcmd: select (setting up stderr): %m\n")); else (void)fprintf(stderr, _("select: protocol failure in circuit setup\n")); (void)close(s2); goto bad; } s3 = accept(s2, (struct sockaddr *)&from, &len); (void)close(s2); if (s3 < 0) { (void)fprintf(stderr, "rcmd: accept: %m\n"); lport = 0; goto bad; } *fd2p = s3; from.sin_port = ntohs((u_short)from.sin_port); if (from.sin_family != AF_INET || from.sin_port >= IPPORT_RESERVED || from.sin_port < 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: %m\n", *ahost); goto bad2; } if (c != 0) { while (read(s, &c, 1) == 1) { (void)write(STDERR_FILENO, &c, 1); if (c == '\n') break; } goto bad2; } sigsetmask(oldmask); return s; bad2: if (lport) (void)close(*fd2p); bad: (void)close(s); sigsetmask(oldmask); return -1; } int rresvport(alport) int *alport; { struct sockaddr_in sin; int s; sin.sin_family = AF_INET; sin.sin_addr.s_addr = INADDR_ANY; s = socket(AF_INET, SOCK_STREAM, 0); if (s < 0) return -1; for (;;) { 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; } (*alport)--; if (*alport == IPPORT_RESERVED/2) { (void)close(s); __set_errno (EAGAIN); /* close */ return -1; } } } int __check_rhosts_file = 1; char *__rcmd_errstr; int ruserok(rhost, superuser, ruser, luser) const char *rhost, *ruser, *luser; int superuser; { struct hostent hostbuf, *hp; size_t buflen; char *buffer; u_int32_t addr; char **ap; int herr; buflen = 1024; buffer = __alloca (buflen); while (__gethostbyname_r (rhost, &hostbuf, buffer, buflen, &hp, &herr) < 0) if (herr != NETDB_INTERNAL || errno != ERANGE) return -1; else { /* Enlarge the buffer. */ buflen *= 2; buffer = __alloca (buflen); } for (ap = hp->h_addr_list; *ap; ++ap) { bcopy(*ap, &addr, sizeof(addr)); if (iruserok(addr, superuser, ruser, luser) == 0) return 0; } return -1; } /* Extremely paranoid file open function. */ static FILE * iruserfopen (char *file, uid_t okuser) { struct stat st; char *cp = NULL; FILE *res = NULL; /* If not a regular file, if owned by someone other than user or root, if writeable by anyone but the owner, or if hardlinked anywhere, quit. */ cp = NULL; if (__lxstat (_STAT_VER, file, &st)) cp = _("lstat failed"); else if (!S_ISREG (st.st_mode)) cp = _("not regular file"); else { res = fopen (file, "r"); if (!res) cp = _("cannot open"); else if (__fxstat (_STAT_VER, fileno (res), &st) < 0) cp = _("fstat failed"); else if (st.st_uid && st.st_uid != okuser) cp = _("bad owner"); else if (st.st_mode & (S_IWGRP|S_IWOTH)) cp = _("writeable by other than owner"); else if (st.st_nlink > 1) cp = _("hard linked somewhere"); } /* If there were any problems, quit. */ if (cp != NULL) { __rcmd_errstr = cp; if (res) fclose (res); return NULL; } return res; } /* * 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) u_int32_t raddr; int superuser; const char *ruser, *luser; { FILE *hostf; int isbad; if (!superuser) hostf = iruserfopen (_PATH_HEQUIV, 0); if (hostf) { isbad = __ivaliduser (hostf, raddr, luser, ruser); fclose (hostf); if (!isbad) return 0; } if (__check_rhosts_file || superuser) { char *pbuf; struct passwd pwdbuf, *pwd; size_t dirlen; size_t buflen = __sysconf (_SC_GETPW_R_SIZE_MAX); char *buffer = __alloca (buflen); uid_t uid; if (__getpwnam_r (luser, &pwdbuf, buffer, buflen, &pwd)) return -1; dirlen = strlen (pwd->pw_dir); pbuf = alloca (dirlen + sizeof "/.rhosts"); __mempcpy (__mempcpy (pbuf, pwd->pw_dir, dirlen), "/.rhosts", sizeof "/.rhosts"); /* Change effective uid while reading .rhosts. If root and reading an NFS mounted file system, can't read files that are protected read/write owner only. */ uid = geteuid (); seteuid (pwd->pw_uid); hostf = iruserfopen (pbuf, pwd->pw_uid); if (hostf != NULL) { isbad = __ivaliduser (hostf, raddr, luser, ruser); fclose (hostf); } seteuid (uid); return isbad; } 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; { register char *user, *p; int ch; char *buf = NULL; size_t bufsize = 0; ssize_t nread; while ((nread = __getline (&buf, &bufsize, hostf)) > 0) { buf[bufsize - 1] = '\0'; /* Make sure it's terminated. */ p = buf; while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') { *p = isupper(*p) ? tolower(*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'; if (__icheckhost(raddr, buf) && strcmp(ruser, *user ? user : luser) == 0) { free (buf); return 0; } } free (buf); return -1; } /* * Returns "true" if match, 0 if no match. */ static int internal_function __icheckhost(raddr, lhost) u_int32_t raddr; register char *lhost; { struct hostent hostbuf, *hp; size_t buflen; char *buffer; register u_int32_t laddr; register char **pp; int herr; /* Try for raw ip address first. */ if (isdigit(*lhost) && (int32_t)(laddr = inet_addr(lhost)) != -1) return raddr == laddr; /* Better be a hostname. */ buflen = 1024; buffer = __alloca (buflen); while (__gethostbyname_r (lhost, &hostbuf, buffer, buflen, &hp, &herr) < 0) if (herr != NETDB_INTERNAL || errno != ERANGE) return 0; else { /* Enlarge the buffer. */ buflen *= 2; buffer = __alloca (buflen); } /* Spin through ip addresses. */ for (pp = hp->h_addr_list; *pp; ++pp) if (!bcmp(&raddr, *pp, sizeof(u_int32_t))) return 1; /* No match. */ return 0; }