/*- * Copyright (c) 1983, 1990, 1993, 1994 * The Regents of the University of California. All rights reserved. * Copyright (c) 2002 Networks Associates Technology, Inc. * All rights reserved. * * Portions of this software were developed for the FreeBSD Project by * ThinkSec AS and NAI Labs, the Security Research Division of Network * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 * ("CBOSS"), as part of the DARPA CHATS research program. * * 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. */ #ifndef lint static const char copyright[] = "@(#) Copyright (c) 1983, 1990, 1993, 1994\n\ The Regents of the University of California. All rights reserved.\n"; #endif /* not lint */ #ifndef lint static const char sccsid[] = "From: @(#)rsh.c 8.3 (Berkeley) 4/6/94"; #endif /* not lint */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * rsh - remote shell */ int rfd2; int family = PF_UNSPEC; char rlogin[] = "rlogin"; void connect_timeout(int); char *copyargs(char * const *); void sendsig(int); void talk(int, long, pid_t, int, int); void usage(void); int main(int argc, char *argv[]) { struct passwd const *pw; struct servent const *sp; long omask; int argoff, asrsh, ch, dflag, nflag, one, rem; pid_t pid = 0; uid_t uid; char *args, *host, *p, *user; int timeout = 0; argoff = asrsh = dflag = nflag = 0; one = 1; host = user = NULL; /* if called as something other than "rsh", use it as the host name */ if ((p = strrchr(argv[0], '/'))) ++p; else p = argv[0]; if (strcmp(p, "rsh")) host = p; else asrsh = 1; /* handle "rsh host flags" */ if (!host && argc > 2 && argv[1][0] != '-') { host = argv[1]; argoff = 1; } #define OPTIONS "468KLde:l:nt:w" while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != -1) switch(ch) { case '4': family = PF_INET; break; case '6': family = PF_INET6; break; case 'L': /* -8Lew are ignored to allow rlogin aliases */ case 'e': case 'w': case '8': break; case 'd': dflag = 1; break; case 'l': user = optarg; break; case 'n': nflag = 1; break; case 't': timeout = atoi(optarg); break; case '?': default: usage(); } optind += argoff; /* if haven't gotten a host yet, do so */ if (!host && !(host = argv[optind++])) usage(); /* if no further arguments, must have been called as rlogin. */ if (!argv[optind]) { if (asrsh) *argv = rlogin; execv(_PATH_RLOGIN, argv); err(1, "can't exec %s", _PATH_RLOGIN); } argc -= optind; argv += optind; if (!(pw = getpwuid(uid = getuid()))) errx(1, "unknown user id"); if (!user) user = pw->pw_name; args = copyargs(argv); sp = NULL; if (sp == NULL) sp = getservbyname("shell", "tcp"); if (sp == NULL) errx(1, "shell/tcp: unknown service"); if (timeout) { signal(SIGALRM, connect_timeout); alarm(timeout); } rem = rcmd_af(&host, sp->s_port, pw->pw_name, user, args, &rfd2, family); if (timeout) { signal(SIGALRM, SIG_DFL); alarm(0); } if (rem < 0) exit(1); if (rfd2 < 0) errx(1, "can't establish stderr"); if (dflag) { if (setsockopt(rem, SOL_SOCKET, SO_DEBUG, &one, sizeof(one)) < 0) warn("setsockopt"); if (setsockopt(rfd2, SOL_SOCKET, SO_DEBUG, &one, sizeof(one)) < 0) warn("setsockopt"); } (void)setuid(uid); omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGTERM)); if (signal(SIGINT, SIG_IGN) != SIG_IGN) (void)signal(SIGINT, sendsig); if (signal(SIGQUIT, SIG_IGN) != SIG_IGN) (void)signal(SIGQUIT, sendsig); if (signal(SIGTERM, SIG_IGN) != SIG_IGN) (void)signal(SIGTERM, sendsig); if (!nflag) { pid = fork(); if (pid < 0) err(1, "fork"); } else (void)shutdown(rem, 1); (void)ioctl(rfd2, FIONBIO, &one); (void)ioctl(rem, FIONBIO, &one); talk(nflag, omask, pid, rem, timeout); if (!nflag) (void)kill(pid, SIGKILL); exit(0); } void talk(int nflag, long omask, pid_t pid, int rem, int timeout) { int cc, wc; fd_set readfrom, ready, rembits; char buf[BUFSIZ]; const char *bp; struct timeval tvtimeout; int nfds, srval; if (!nflag && pid == 0) { (void)close(rfd2); reread: errno = 0; if ((cc = read(0, buf, sizeof buf)) <= 0) goto done; bp = buf; rewrite: if (rem >= FD_SETSIZE) errx(1, "descriptor too big"); FD_ZERO(&rembits); FD_SET(rem, &rembits); nfds = rem + 1; if (select(nfds, 0, &rembits, 0, 0) < 0) { if (errno != EINTR) err(1, "select"); goto rewrite; } if (!FD_ISSET(rem, &rembits)) goto rewrite; wc = write(rem, bp, cc); if (wc < 0) { if (errno == EWOULDBLOCK) goto rewrite; goto done; } bp += wc; cc -= wc; if (cc == 0) goto reread; goto rewrite; done: (void)shutdown(rem, 1); exit(0); } tvtimeout.tv_sec = timeout; tvtimeout.tv_usec = 0; (void)sigsetmask(omask); if (rfd2 >= FD_SETSIZE || rem >= FD_SETSIZE) errx(1, "descriptor too big"); FD_ZERO(&readfrom); FD_SET(rfd2, &readfrom); FD_SET(rem, &readfrom); nfds = MAX(rfd2+1, rem+1); do { ready = readfrom; if (timeout) { srval = select(nfds, &ready, 0, 0, &tvtimeout); } else { srval = select(nfds, &ready, 0, 0, 0); } if (srval < 0) { if (errno != EINTR) err(1, "select"); continue; } if (srval == 0) errx(1, "timeout reached (%d seconds)\n", timeout); if (FD_ISSET(rfd2, &ready)) { errno = 0; cc = read(rfd2, buf, sizeof buf); if (cc <= 0) { if (errno != EWOULDBLOCK) FD_CLR(rfd2, &readfrom); } else (void)write(STDERR_FILENO, buf, cc); } if (FD_ISSET(rem, &ready)) { errno = 0; cc = read(rem, buf, sizeof buf); if (cc <= 0) { if (errno != EWOULDBLOCK) FD_CLR(rem, &readfrom); } else (void)write(STDOUT_FILENO, buf, cc); } } while (FD_ISSET(rfd2, &readfrom) || FD_ISSET(rem, &readfrom)); } void connect_timeout(int sig) { char message[] = "timeout reached before connection completed.\n"; write(STDERR_FILENO, message, sizeof(message) - 1); _exit(1); } void sendsig(int sig) { char signo; signo = sig; (void)write(rfd2, &signo, 1); } char * copyargs(char * const *argv) { int cc; char *args, *p; char * const *ap; cc = 0; for (ap = argv; *ap; ++ap) cc += strlen(*ap) + 1; if (!(args = malloc((u_int)cc))) err(1, NULL); for (p = args, ap = argv; *ap; ++ap) { (void)strcpy(p, *ap); for (p = strcpy(p, *ap); *p; ++p); if (ap[1]) *p++ = ' '; } return (args); } void usage(void) { (void)fprintf(stderr, "usage: rsh [-46] [-nd] [-l login] [-t timeout] host [command]\n"); exit(1); }