/* * 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 <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 *)); int rcmd(ahost, rport, locuser, remuser, cmd, fd2p) char **ahost; u_short rport; const char *locuser, *remuser, *cmd; int *fd2p; { struct hostent *hp; struct sockaddr_in sin, from; fd_set reads; int32_t oldmask; pid_t pid; int s, lport, timo; char c; pid = getpid(); hp = gethostbyname(*ahost); if (hp == NULL) { herror(*ahost); return (-1); } *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: %s\n", strerror(errno)); sigsetmask(oldmask); return (-1); } fcntl(s, F_SETOWN, pid); sin.sin_family = hp->h_addrtype; bcopy(hp->h_addr_list[0], &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)); errno = oerrno; perror(0); hp->h_addr_list++; bcopy(hp->h_addr_list[0], &sin.sin_addr, hp->h_length); (void)fprintf(stderr, _("Trying %s...\n"), inet_ntoa(sin.sin_addr)); continue; } (void)fprintf(stderr, "%s: %s\n", hp->h_name, strerror(errno)); sigsetmask(oldmask); return (-1); } lport--; if (fd2p == 0) { write(s, "", 1); lport = 0; } else { char num[8]; int s2 = rresvport(&lport), s3; int 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): %s\n"), strerror(errno)); (void)close(s2); goto bad; } FD_ZERO(&reads); FD_SET(s, &reads); FD_SET(s2, &reads); 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): %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); (void)close(s2); if (s3 < 0) { (void)fprintf(stderr, "rcmd: accept: %s\n", strerror(errno)); 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: %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; } 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); 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 *hp; u_int32_t addr; char **ap; if ((hp = gethostbyname(rhost)) == NULL) return (-1); for (ap = hp->h_addr_list; *ap; ++ap) { bcopy(*ap, &addr, sizeof(addr)); if (iruserok(addr, superuser, ruser, luser) == 0) return (0); } 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) u_int32_t raddr; int superuser; const char *ruser, *luser; { register char *cp; struct stat sbuf; struct passwd *pwd; FILE *hostf; uid_t uid; int first; first = 1; hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r"); again: if (hostf) { if (__ivaliduser(hostf, raddr, luser, ruser) == 0) { (void)fclose(hostf); return (0); } (void)fclose(hostf); } if (first == 1 && (__check_rhosts_file || superuser)) { char *pbuf; size_t dirlen; first = 0; if ((pwd = getpwnam(luser)) == NULL) return (-1); dirlen = strlen (pwd->pw_dir); pbuf = alloca (dirlen + sizeof "/.rhosts"); memcpy (pbuf, pwd->pw_dir, dirlen); memcpy (pbuf + dirlen, "/.rhosts", sizeof "/.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; { 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 __icheckhost(raddr, lhost) u_int32_t raddr; register char *lhost; { register struct hostent *hp; register u_int32_t laddr; register char **pp; /* Try for raw ip address first. */ if (isdigit(*lhost) && (int32_t)(laddr = inet_addr(lhost)) != -1) return (raddr == laddr); /* Better be a hostname. */ if ((hp = gethostbyname(lhost)) == NULL) return (0); /* 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); }