11592Srgrimes/*- 21592Srgrimes * Copyright (c) 1988, 1989, 1992, 1993, 1994 31592Srgrimes * The Regents of the University of California. All rights reserved. 496195Sdes * Copyright (c) 2002 Networks Associates Technology, Inc. 596195Sdes * All rights reserved. 61592Srgrimes * 796195Sdes * Portions of this software were developed for the FreeBSD Project by 896195Sdes * ThinkSec AS and NAI Labs, the Security Research Division of Network 996195Sdes * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 1096195Sdes * ("CBOSS"), as part of the DARPA CHATS research program. 1196195Sdes * 121592Srgrimes * Redistribution and use in source and binary forms, with or without 131592Srgrimes * modification, are permitted provided that the following conditions 141592Srgrimes * are met: 151592Srgrimes * 1. Redistributions of source code must retain the above copyright 161592Srgrimes * notice, this list of conditions and the following disclaimer. 171592Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 181592Srgrimes * notice, this list of conditions and the following disclaimer in the 191592Srgrimes * documentation and/or other materials provided with the distribution. 20262435Sbrueffer * 3. Neither the name of the University nor the names of its contributors 211592Srgrimes * may be used to endorse or promote products derived from this software 221592Srgrimes * without specific prior written permission. 231592Srgrimes * 241592Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 251592Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 261592Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 271592Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 281592Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 291592Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 301592Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 311592Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 321592Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 331592Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 341592Srgrimes * SUCH DAMAGE. 351592Srgrimes */ 361592Srgrimes 371592Srgrimes#ifndef lint 3829917Smarkmstatic const char copyright[] = 391592Srgrimes"@(#) Copyright (c) 1988, 1989, 1992, 1993, 1994\n\ 401592Srgrimes The Regents of the University of California. All rights reserved.\n"; 411592Srgrimes#endif /* not lint */ 421592Srgrimes 431592Srgrimes#ifndef lint 4431490Scharnier#if 0 4529917Smarkmstatic const char sccsid[] = "@(#)rshd.c 8.2 (Berkeley) 4/6/94"; 4631490Scharnier#endif 471592Srgrimes#endif /* not lint */ 481592Srgrimes 4998885Smarkm#include <sys/cdefs.h> 5098885Smarkm__FBSDID("$FreeBSD: stable/10/libexec/rshd/rshd.c 321069 2017-07-17 06:37:46Z delphij $"); 5198885Smarkm 521592Srgrimes/* 531592Srgrimes * remote shell server: 541592Srgrimes * [port]\0 5596195Sdes * ruser\0 5696195Sdes * luser\0 571592Srgrimes * command\0 581592Srgrimes * data 591592Srgrimes */ 601592Srgrimes#include <sys/param.h> 611592Srgrimes#include <sys/ioctl.h> 621592Srgrimes#include <sys/time.h> 631592Srgrimes#include <sys/socket.h> 641592Srgrimes 6522454Simp#include <netinet/in_systm.h> 661592Srgrimes#include <netinet/in.h> 6722454Simp#include <netinet/ip.h> 6841445Sdg#include <netinet/tcp.h> 691592Srgrimes#include <arpa/inet.h> 701592Srgrimes#include <netdb.h> 711592Srgrimes 7276094Smarkm#include <err.h> 731592Srgrimes#include <errno.h> 741592Srgrimes#include <fcntl.h> 7545393Sbrian#include <libutil.h> 761592Srgrimes#include <paths.h> 771592Srgrimes#include <pwd.h> 781592Srgrimes#include <signal.h> 7976134Smarkm#include <stdarg.h> 801592Srgrimes#include <stdio.h> 811592Srgrimes#include <stdlib.h> 821592Srgrimes#include <string.h> 831592Srgrimes#include <syslog.h> 841592Srgrimes#include <unistd.h> 8525099Sdavidn#include <login_cap.h> 861592Srgrimes 8774874Smarkm#include <security/pam_appl.h> 8896195Sdes#include <security/openpam.h> 8974874Smarkm#include <sys/wait.h> 9074874Smarkm 9196195Sdesstatic struct pam_conv pamc = { openpam_nullconv, NULL }; 9274874Smarkmstatic pam_handle_t *pamh; 9396195Sdesstatic int pam_err; 9474874Smarkm 9574874Smarkm#define PAM_END { \ 9696195Sdes if ((pam_err = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS) \ 9796195Sdes syslog(LOG_ERR|LOG_AUTH, "pam_setcred(): %s", pam_strerror(pamh, pam_err)); \ 9896195Sdes if ((pam_err = pam_close_session(pamh,0)) != PAM_SUCCESS) \ 9996195Sdes syslog(LOG_ERR|LOG_AUTH, "pam_close_session(): %s", pam_strerror(pamh, pam_err)); \ 10096195Sdes if ((pam_err = pam_end(pamh, pam_err)) != PAM_SUCCESS) \ 10196195Sdes syslog(LOG_ERR|LOG_AUTH, "pam_end(): %s", pam_strerror(pamh, pam_err)); \ 10274874Smarkm} 10374874Smarkm 1041592Srgrimesint keepalive = 1; 1051592Srgrimesint log_success; /* If TRUE, log all successful accesses */ 1061592Srgrimesint sent_null; 10741445Sdgint no_delay; 1081592Srgrimes 10996195Sdesvoid doit(struct sockaddr *); 11090334Simpstatic void rshd_errx(int, const char *, ...) __printf0like(2, 3); 11190335Simpvoid getstr(char *, int, const char *); 11290334Simpint local_domain(char *); 11390334Simpchar *topdomain(char *); 11490334Simpvoid usage(void); 1151592Srgrimes 11698885Smarkmchar slash[] = "/"; 11798885Smarkmchar bshell[] = _PATH_BSHELL; 11898885Smarkm 119141589Sru#define OPTIONS "aDLln" 12051433Smarkm 1211592Srgrimesint 12290334Simpmain(int argc, char *argv[]) 1231592Srgrimes{ 1241592Srgrimes extern int __check_rhosts_file; 1251592Srgrimes struct linger linger; 126141918Sstefanf socklen_t fromlen; 127141918Sstefanf int ch, on = 1; 12856590Sshin struct sockaddr_storage from; 1291592Srgrimes 1301592Srgrimes openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON); 1311592Srgrimes 1321592Srgrimes opterr = 0; 13324349Simp while ((ch = getopt(argc, argv, OPTIONS)) != -1) 1341592Srgrimes switch (ch) { 1351592Srgrimes case 'a': 13672093Sasmodai /* ignored for compatibility */ 1371592Srgrimes break; 1381592Srgrimes case 'l': 1391592Srgrimes __check_rhosts_file = 0; 1401592Srgrimes break; 1411592Srgrimes case 'n': 1421592Srgrimes keepalive = 0; 1431592Srgrimes break; 14441445Sdg case 'D': 14541445Sdg no_delay = 1; 14641445Sdg break; 1471592Srgrimes case 'L': 1481592Srgrimes log_success = 1; 1491592Srgrimes break; 1501592Srgrimes case '?': 1511592Srgrimes default: 1521592Srgrimes usage(); 1531592Srgrimes break; 1541592Srgrimes } 1551592Srgrimes 1561592Srgrimes argc -= optind; 1571592Srgrimes argv += optind; 1581592Srgrimes 1591592Srgrimes fromlen = sizeof (from); 1601592Srgrimes if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 1611592Srgrimes syslog(LOG_ERR, "getpeername: %m"); 16235728Srnordier exit(1); 1631592Srgrimes } 1641592Srgrimes if (keepalive && 1651592Srgrimes setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on, 1661592Srgrimes sizeof(on)) < 0) 1671592Srgrimes syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); 1681592Srgrimes linger.l_onoff = 1; 1691592Srgrimes linger.l_linger = 60; /* XXX */ 1701592Srgrimes if (setsockopt(0, SOL_SOCKET, SO_LINGER, (char *)&linger, 1711592Srgrimes sizeof (linger)) < 0) 1721592Srgrimes syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m"); 17341445Sdg if (no_delay && 17441445Sdg setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0) 17541445Sdg syslog(LOG_WARNING, "setsockopt (TCP_NODELAY): %m"); 17696195Sdes doit((struct sockaddr *)&from); 1771592Srgrimes /* NOTREACHED */ 17829917Smarkm return(0); 1791592Srgrimes} 1801592Srgrimes 18196195Sdesextern char **environ; 18274874Smarkm 1831592Srgrimesvoid 18496195Sdesdoit(struct sockaddr *fromp) 1851592Srgrimes{ 1861592Srgrimes extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */ 1871592Srgrimes struct passwd *pwd; 1881592Srgrimes u_short port; 1891592Srgrimes fd_set ready, readfrom; 19096195Sdes int cc, fd, nfd, pv[2], pid, s; 1911592Srgrimes int one = 1; 19296195Sdes const char *cp, *errorstr; 19396195Sdes char sig, buf[BUFSIZ]; 194143907Sdas char *cmdbuf, luser[16], ruser[16]; 19596195Sdes char rhost[2 * MAXHOSTNAMELEN + 1]; 19656590Sshin char numericname[INET6_ADDRSTRLEN]; 19798885Smarkm int af, srcport; 198143907Sdas int maxcmdlen; 19925099Sdavidn login_cap_t *lc; 2001592Srgrimes 201143907Sdas maxcmdlen = (int)sysconf(_SC_ARG_MAX); 202143907Sdas if (maxcmdlen <= 0 || (cmdbuf = malloc(maxcmdlen)) == NULL) 203143907Sdas exit(1); 204143907Sdas 2051592Srgrimes (void) signal(SIGINT, SIG_DFL); 2061592Srgrimes (void) signal(SIGQUIT, SIG_DFL); 2071592Srgrimes (void) signal(SIGTERM, SIG_DFL); 20896195Sdes af = fromp->sa_family; 20996195Sdes srcport = ntohs(*((in_port_t *)&fromp->sa_data)); 21096195Sdes if (af == AF_INET) { 21196195Sdes inet_ntop(af, &((struct sockaddr_in *)fromp)->sin_addr, 21296195Sdes numericname, sizeof numericname); 21396195Sdes } else if (af == AF_INET6) { 21496195Sdes inet_ntop(af, &((struct sockaddr_in6 *)fromp)->sin6_addr, 21596195Sdes numericname, sizeof numericname); 21696195Sdes } else { 21774874Smarkm syslog(LOG_ERR, "malformed \"from\" address (af %d)", af); 2181592Srgrimes exit(1); 2191592Srgrimes } 2201592Srgrimes#ifdef IP_OPTIONS 22196195Sdes if (af == AF_INET) { 22296195Sdes u_char optbuf[BUFSIZ/3]; 223141918Sstefanf socklen_t optsize = sizeof(optbuf), ipproto, i; 22496195Sdes struct protoent *ip; 2251592Srgrimes 22696195Sdes if ((ip = getprotobyname("ip")) != NULL) 22796195Sdes ipproto = ip->p_proto; 22896195Sdes else 22996195Sdes ipproto = IPPROTO_IP; 23096195Sdes if (!getsockopt(0, ipproto, IP_OPTIONS, optbuf, &optsize) && 23196195Sdes optsize != 0) { 23296195Sdes for (i = 0; i < optsize; ) { 23396195Sdes u_char c = optbuf[i]; 23496195Sdes if (c == IPOPT_LSRR || c == IPOPT_SSRR) { 23596195Sdes syslog(LOG_NOTICE, 23696195Sdes "connection refused from %s with IP option %s", 23796195Sdes numericname, 23896195Sdes c == IPOPT_LSRR ? "LSRR" : "SSRR"); 23996195Sdes exit(1); 24096195Sdes } 24196195Sdes if (c == IPOPT_EOL) 24296195Sdes break; 24396195Sdes i += (c == IPOPT_NOP) ? 1 : optbuf[i+1]; 24422454Simp } 2451592Srgrimes } 2461592Srgrimes } 2471592Srgrimes#endif 2481592Srgrimes 24996195Sdes if (srcport >= IPPORT_RESERVED || 25096195Sdes srcport < IPPORT_RESERVED/2) { 25151433Smarkm syslog(LOG_NOTICE|LOG_AUTH, 25251433Smarkm "connection from %s on illegal port %u", 25356590Sshin numericname, 25496195Sdes srcport); 25551433Smarkm exit(1); 25651433Smarkm } 2571592Srgrimes 2581592Srgrimes (void) alarm(60); 2591592Srgrimes port = 0; 26041860Speter s = 0; /* not set or used if port == 0 */ 2611592Srgrimes for (;;) { 2621592Srgrimes char c; 2631592Srgrimes if ((cc = read(STDIN_FILENO, &c, 1)) != 1) { 2641592Srgrimes if (cc < 0) 2651592Srgrimes syslog(LOG_NOTICE, "read: %m"); 266146074Sjmallett shutdown(0, SHUT_RDWR); 2671592Srgrimes exit(1); 2681592Srgrimes } 26941860Speter if (c == 0) 2701592Srgrimes break; 2711592Srgrimes port = port * 10 + c - '0'; 2721592Srgrimes } 2731592Srgrimes 2741592Srgrimes (void) alarm(0); 2751592Srgrimes if (port != 0) { 2761592Srgrimes int lport = IPPORT_RESERVED - 1; 27756590Sshin s = rresvport_af(&lport, af); 2781592Srgrimes if (s < 0) { 2791592Srgrimes syslog(LOG_ERR, "can't get stderr port: %m"); 2801592Srgrimes exit(1); 2811592Srgrimes } 28251433Smarkm if (port >= IPPORT_RESERVED || 28351433Smarkm port < IPPORT_RESERVED/2) { 28451433Smarkm syslog(LOG_NOTICE|LOG_AUTH, 28551433Smarkm "2nd socket from %s on unreserved port %u", 28656590Sshin numericname, 28751433Smarkm port); 28851433Smarkm exit(1); 28951433Smarkm } 29096195Sdes *((in_port_t *)&fromp->sa_data) = htons(port); 29196195Sdes if (connect(s, fromp, fromp->sa_len) < 0) { 2921592Srgrimes syslog(LOG_INFO, "connect second port %d: %m", port); 2931592Srgrimes exit(1); 2941592Srgrimes } 2951592Srgrimes } 2961592Srgrimes 2971592Srgrimes errorstr = NULL; 29896195Sdes realhostname_sa(rhost, sizeof(rhost) - 1, fromp, fromp->sa_len); 29996195Sdes rhost[sizeof(rhost) - 1] = '\0'; 30096195Sdes /* XXX truncation! */ 3011592Srgrimes 30296195Sdes (void) alarm(60); 30396195Sdes getstr(ruser, sizeof(ruser), "ruser"); 30496195Sdes getstr(luser, sizeof(luser), "luser"); 305143907Sdas getstr(cmdbuf, maxcmdlen, "command"); 30696195Sdes (void) alarm(0); 30774874Smarkm 30896195Sdes pam_err = pam_start("rsh", luser, &pamc, &pamh); 30996195Sdes if (pam_err != PAM_SUCCESS) { 31096195Sdes syslog(LOG_ERR|LOG_AUTH, "pam_start(): %s", 31196195Sdes pam_strerror(pamh, pam_err)); 31276134Smarkm rshd_errx(1, "Login incorrect."); 31374874Smarkm } 31474874Smarkm 31596195Sdes if ((pam_err = pam_set_item(pamh, PAM_RUSER, ruser)) != PAM_SUCCESS || 316226937Sbrueffer (pam_err = pam_set_item(pamh, PAM_RHOST, rhost)) != PAM_SUCCESS) { 31796195Sdes syslog(LOG_ERR|LOG_AUTH, "pam_set_item(): %s", 31896195Sdes pam_strerror(pamh, pam_err)); 31976134Smarkm rshd_errx(1, "Login incorrect."); 32074874Smarkm } 32174874Smarkm 32296195Sdes pam_err = pam_authenticate(pamh, 0); 32396195Sdes if (pam_err == PAM_SUCCESS) { 32496195Sdes if ((pam_err = pam_get_user(pamh, &cp, NULL)) == PAM_SUCCESS) { 325321069Sdelphij strlcpy(luser, cp, sizeof(luser)); 32696195Sdes /* XXX truncation! */ 32796195Sdes } 32896195Sdes pam_err = pam_acct_mgmt(pamh, 0); 32974874Smarkm } 33096195Sdes if (pam_err != PAM_SUCCESS) { 33196195Sdes syslog(LOG_INFO|LOG_AUTH, 33296195Sdes "%s@%s as %s: permission denied (%s). cmd='%.80s'", 33396195Sdes ruser, rhost, luser, pam_strerror(pamh, pam_err), cmdbuf); 33476134Smarkm rshd_errx(1, "Login incorrect."); 33574874Smarkm } 33674874Smarkm 3371592Srgrimes setpwent(); 33896195Sdes pwd = getpwnam(luser); 3391592Srgrimes if (pwd == NULL) { 3401592Srgrimes syslog(LOG_INFO|LOG_AUTH, 3411592Srgrimes "%s@%s as %s: unknown login. cmd='%.80s'", 34296195Sdes ruser, rhost, luser, cmdbuf); 3431592Srgrimes if (errorstr == NULL) 34476094Smarkm errorstr = "Login incorrect."; 34596195Sdes rshd_errx(1, errorstr, rhost); 3461592Srgrimes } 34774874Smarkm 34825674Sdavidn lc = login_getpwclass(pwd); 34974874Smarkm if (pwd->pw_uid) 35074874Smarkm auth_checknologin(lc); 35174874Smarkm 3521592Srgrimes if (chdir(pwd->pw_dir) < 0) { 35325099Sdavidn if (chdir("/") < 0 || 35425099Sdavidn login_getcapbool(lc, "requirehome", !!pwd->pw_uid)) { 35525099Sdavidn syslog(LOG_INFO|LOG_AUTH, 35625099Sdavidn "%s@%s as %s: no home directory. cmd='%.80s'", 35796195Sdes ruser, rhost, luser, cmdbuf); 35876134Smarkm rshd_errx(0, "No remote home directory."); 35925099Sdavidn } 36098885Smarkm pwd->pw_dir = slash; 3611592Srgrimes } 3621592Srgrimes 36396195Sdes if (lc != NULL && fromp->sa_family == AF_INET) { /*XXX*/ 36425099Sdavidn char remote_ip[MAXHOSTNAMELEN]; 36525099Sdavidn 366321069Sdelphij strlcpy(remote_ip, numericname, sizeof(remote_ip)); 36796195Sdes /* XXX truncation! */ 36896195Sdes if (!auth_hostok(lc, rhost, remote_ip)) { 36925099Sdavidn syslog(LOG_INFO|LOG_AUTH, 37025099Sdavidn "%s@%s as %s: permission denied (%s). cmd='%.80s'", 37196195Sdes ruser, rhost, luser, __rcmd_errstr, 37225099Sdavidn cmdbuf); 37376134Smarkm rshd_errx(1, "Login incorrect."); 37425099Sdavidn } 37576094Smarkm if (!auth_timeok(lc, time(NULL))) 37676134Smarkm rshd_errx(1, "Logins not available right now"); 37725099Sdavidn } 3781592Srgrimes 37974874Smarkm /* 38074874Smarkm * PAM modules might add supplementary groups in 38174874Smarkm * pam_setcred(), so initialize them first. 38274874Smarkm * But we need to open the session as root. 38374874Smarkm */ 38474874Smarkm if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) { 38596195Sdes syslog(LOG_ERR, "setusercontext: %m"); 38674874Smarkm exit(1); 38774874Smarkm } 38874874Smarkm 38996195Sdes if ((pam_err = pam_open_session(pamh, 0)) != PAM_SUCCESS) { 39096195Sdes syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, pam_err)); 39196195Sdes } else if ((pam_err = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) { 39296195Sdes syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, pam_err)); 39374874Smarkm } 39474874Smarkm 3951592Srgrimes (void) write(STDERR_FILENO, "\0", 1); 3961592Srgrimes sent_null = 1; 3971592Srgrimes 3981592Srgrimes if (port) { 39976094Smarkm if (pipe(pv) < 0) 40076134Smarkm rshd_errx(1, "Can't make pipe."); 4011592Srgrimes pid = fork(); 40276094Smarkm if (pid == -1) 40376134Smarkm rshd_errx(1, "Can't fork; try again."); 4041592Srgrimes if (pid) { 40598885Smarkm (void) close(0); 40698885Smarkm (void) close(1); 4071592Srgrimes (void) close(2); 4081592Srgrimes (void) close(pv[1]); 4091592Srgrimes 4101592Srgrimes FD_ZERO(&readfrom); 4111592Srgrimes FD_SET(s, &readfrom); 4121592Srgrimes FD_SET(pv[0], &readfrom); 4131592Srgrimes if (pv[0] > s) 4141592Srgrimes nfd = pv[0]; 4151592Srgrimes else 4161592Srgrimes nfd = s; 4171592Srgrimes ioctl(pv[0], FIONBIO, (char *)&one); 4181592Srgrimes 4191592Srgrimes /* should set s nbio! */ 4201592Srgrimes nfd++; 4211592Srgrimes do { 4221592Srgrimes ready = readfrom; 42398885Smarkm if (select(nfd, &ready, (fd_set *)0, 42498885Smarkm (fd_set *)0, (struct timeval *)0) < 0) 42598885Smarkm break; 4261592Srgrimes if (FD_ISSET(s, &ready)) { 4271592Srgrimes int ret; 4281592Srgrimes ret = read(s, &sig, 1); 42998885Smarkm if (ret <= 0) 43098885Smarkm FD_CLR(s, &readfrom); 43198885Smarkm else 43298885Smarkm killpg(pid, sig); 4331592Srgrimes } 4341592Srgrimes if (FD_ISSET(pv[0], &ready)) { 4351592Srgrimes errno = 0; 4361592Srgrimes cc = read(pv[0], buf, sizeof(buf)); 4371592Srgrimes if (cc <= 0) { 438146074Sjmallett shutdown(s, SHUT_RDWR); 4391592Srgrimes FD_CLR(pv[0], &readfrom); 4401592Srgrimes } else { 44198885Smarkm (void)write(s, buf, cc); 4421592Srgrimes } 4431592Srgrimes } 4441592Srgrimes 4451592Srgrimes } while (FD_ISSET(s, &readfrom) || 4461592Srgrimes FD_ISSET(pv[0], &readfrom)); 44774874Smarkm PAM_END; 4481592Srgrimes exit(0); 4491592Srgrimes } 4501592Srgrimes (void) close(s); 4511592Srgrimes (void) close(pv[0]); 4521592Srgrimes dup2(pv[1], 2); 4531592Srgrimes close(pv[1]); 4541592Srgrimes } 45574874Smarkm else { 45674874Smarkm pid = fork(); 45776094Smarkm if (pid == -1) 45876134Smarkm rshd_errx(1, "Can't fork; try again."); 45974874Smarkm if (pid) { 46074874Smarkm /* Parent. */ 46196195Sdes while (wait(NULL) > 0 || errno == EINTR) 46296195Sdes /* nothing */ ; 46374874Smarkm PAM_END; 46474874Smarkm exit(0); 46574874Smarkm } 46674874Smarkm } 46774874Smarkm 46896195Sdes for (fd = getdtablesize(); fd > 2; fd--) 46996195Sdes (void) close(fd); 47096195Sdes if (setsid() == -1) 47196195Sdes syslog(LOG_ERR, "setsid() failed: %m"); 47296195Sdes if (setlogin(pwd->pw_name) < 0) 47396195Sdes syslog(LOG_ERR, "setlogin() failed: %m"); 47496195Sdes 4751592Srgrimes if (*pwd->pw_shell == '\0') 47698885Smarkm pwd->pw_shell = bshell; 47796195Sdes (void) pam_setenv(pamh, "HOME", pwd->pw_dir, 1); 47896195Sdes (void) pam_setenv(pamh, "SHELL", pwd->pw_shell, 1); 47996195Sdes (void) pam_setenv(pamh, "USER", pwd->pw_name, 1); 48096195Sdes (void) pam_setenv(pamh, "PATH", _PATH_DEFPATH, 1); 48196195Sdes environ = pam_getenvlist(pamh); 48296195Sdes (void) pam_end(pamh, pam_err); 4831592Srgrimes cp = strrchr(pwd->pw_shell, '/'); 4841592Srgrimes if (cp) 4851592Srgrimes cp++; 4861592Srgrimes else 4871592Srgrimes cp = pwd->pw_shell; 48874874Smarkm 48996195Sdes if (setusercontext(lc, pwd, pwd->pw_uid, 49096195Sdes LOGIN_SETALL & ~LOGIN_SETGROUP) < 0) { 49196195Sdes syslog(LOG_ERR, "setusercontext(): %m"); 49225099Sdavidn exit(1); 49325099Sdavidn } 49425099Sdavidn login_close(lc); 4951592Srgrimes endpwent(); 4961592Srgrimes if (log_success || pwd->pw_uid == 0) { 4971592Srgrimes syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'", 49896195Sdes ruser, rhost, luser, cmdbuf); 4991592Srgrimes } 500127864Smux execl(pwd->pw_shell, cp, "-c", cmdbuf, (char *)NULL); 50196195Sdes err(1, "%s", pwd->pw_shell); 5021592Srgrimes exit(1); 5031592Srgrimes} 5041592Srgrimes 50576134Smarkm/* 50676134Smarkm * Report error to client. Note: can't be used until second socket has 50776134Smarkm * connected to client, or older clients will hang waiting for that 50876134Smarkm * connection first. 50976134Smarkm */ 51076134Smarkm 51176134Smarkmstatic void 51276134Smarkmrshd_errx(int errcode, const char *fmt, ...) 51376134Smarkm{ 51476134Smarkm va_list ap; 51576134Smarkm 51676134Smarkm va_start(ap, fmt); 51776134Smarkm 51876134Smarkm if (sent_null == 0) 51976134Smarkm write(STDERR_FILENO, "\1", 1); 52076134Smarkm 52176134Smarkm verrx(errcode, fmt, ap); 52276134Smarkm /* NOTREACHED */ 52376134Smarkm} 52476134Smarkm 5251592Srgrimesvoid 52690335Simpgetstr(char *buf, int cnt, const char *error) 5271592Srgrimes{ 5281592Srgrimes char c; 5291592Srgrimes 5301592Srgrimes do { 5311592Srgrimes if (read(STDIN_FILENO, &c, 1) != 1) 5321592Srgrimes exit(1); 5331592Srgrimes *buf++ = c; 53476125Smarkm if (--cnt == 0) 53590335Simp rshd_errx(1, "%s too long", error); 5361592Srgrimes } while (c != 0); 5371592Srgrimes} 5381592Srgrimes 5391592Srgrimes/* 5401592Srgrimes * Check whether host h is in our local domain, 5411592Srgrimes * defined as sharing the last two components of the domain part, 5421592Srgrimes * or the entire domain part if the local domain has only one component. 5431592Srgrimes * If either name is unqualified (contains no '.'), 5441592Srgrimes * assume that the host is local, as it will be 5451592Srgrimes * interpreted as such. 5461592Srgrimes */ 5471592Srgrimesint 54890334Simplocal_domain(char *h) 5491592Srgrimes{ 5501592Srgrimes char localhost[MAXHOSTNAMELEN]; 5511592Srgrimes char *p1, *p2; 5521592Srgrimes 5531592Srgrimes localhost[0] = 0; 55445422Sbrian (void) gethostname(localhost, sizeof(localhost) - 1); 55545422Sbrian localhost[sizeof(localhost) - 1] = '\0'; 55696195Sdes /* XXX truncation! */ 5571592Srgrimes p1 = topdomain(localhost); 5581592Srgrimes p2 = topdomain(h); 5591592Srgrimes if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2)) 5601592Srgrimes return (1); 5611592Srgrimes return (0); 5621592Srgrimes} 5631592Srgrimes 5641592Srgrimeschar * 56590334Simptopdomain(char *h) 5661592Srgrimes{ 5671592Srgrimes char *p, *maybe = NULL; 5681592Srgrimes int dots = 0; 5691592Srgrimes 5701592Srgrimes for (p = h + strlen(h); p >= h; p--) { 5711592Srgrimes if (*p == '.') { 5721592Srgrimes if (++dots == 2) 5731592Srgrimes return (p); 5741592Srgrimes maybe = p; 5751592Srgrimes } 5761592Srgrimes } 5771592Srgrimes return (maybe); 5781592Srgrimes} 5791592Srgrimes 5801592Srgrimesvoid 58190334Simpusage(void) 5821592Srgrimes{ 5831592Srgrimes 5841592Srgrimes syslog(LOG_ERR, "usage: rshd [-%s]", OPTIONS); 5851592Srgrimes exit(2); 5861592Srgrimes} 587