/*      $NetBSD: rshd.c,v 1.51 2017/10/07 19:23:02 ryo Exp $    */

/*
 * Copyright (C) 1998 WIDE Project.
 * 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 WIDE Project and
 *    its contributors.
 * 4. Neither the name of the project 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 PROJECT 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 PROJECT 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.
 */

/*-
 * Copyright (c) 1988, 1989, 1992, 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. 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.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1988, 1989, 1992, 1993, 1994\
 The Regents of the University of California.  All rights reserved.");
#if 0
static char sccsid[] = "@(#)rshd.c      8.2 (Berkeley) 4/6/94";
#else
__RCSID("$NetBSD: rshd.c,v 1.51 2017/10/07 19:23:02 ryo Exp $");
#endif
#endif /* not lint */

/*
 * remote shell server:
 *      [port]\0
 *      remuser\0
 *      locuser\0
 *      command\0
 *      data
 */
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/socket.h>

#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>

#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <poll.h>
#ifdef  LOGIN_CAP
#include <login_cap.h>
#endif

#ifdef USE_PAM
#include <security/pam_appl.h>
#include <security/openpam.h>
#include <sys/wait.h>

static struct pam_conv pamc = { openpam_nullconv, NULL };
static pam_handle_t *pamh;
static int pam_err;

#define PAM_END do { \
        if ((pam_err = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS) \
                syslog(LOG_ERR|LOG_AUTH, "pam_setcred(): %s", \
                    pam_strerror(pamh, pam_err)); \
        if ((pam_err = pam_close_session(pamh,0)) != PAM_SUCCESS) \
                syslog(LOG_ERR|LOG_AUTH, "pam_close_session(): %s", \
                    pam_strerror(pamh, pam_err)); \
        if ((pam_err = pam_end(pamh, pam_err)) != PAM_SUCCESS) \
                syslog(LOG_ERR|LOG_AUTH, "pam_end(): %s", \
                    pam_strerror(pamh, pam_err)); \
} while (/*CONSTCOND*/0)
#else
#define PAM_END
#endif

static int      keepalive = 1;
static int      check_all;
static int      log_success;            /* If TRUE, log all successful accesses */
static int      sent_null;

__dead static void       doit(struct sockaddr *, struct sockaddr *);
__dead static void       rshd_errx(int, const char *, ...) __printflike(2, 3);
static void      getstr(char *, int, const char *);
static int       local_domain(char *);
static char     *topdomain(char *);
__dead static void       usage(void);

#define OPTIONS "aLln"
extern int __check_rhosts_file;
extern char *__rcmd_errstr;     /* syslog hook from libc/net/rcmd.c. */
#ifdef USE_PAM
static const char incorrect[] = "Login incorrect.";
#endif

int
main(int argc, char *argv[])
{
        struct linger linger;
        int ch, on = 1;
        socklen_t fromlen;
        socklen_t locallen;
        struct sockaddr_storage from;
        struct sockaddr_storage local;
        struct protoent *proto;

        openlog("rshd", LOG_PID, LOG_DAEMON);

        opterr = 0;
        while ((ch = getopt(argc, argv, OPTIONS)) != -1)
                switch (ch) {
                case 'a':
                        check_all = 1;
                        break;
                case 'l':
                        __check_rhosts_file = 0;
                        break;
                case 'n':
                        keepalive = 0;
                        break;
                case 'L':
                        log_success = 1;
                        break;
                case '?':
                default:
                        usage();
                        break;
                }

        argc -= optind;
        argv += optind;

        fromlen = sizeof(from); /* xxx */
        locallen = sizeof(local); /* xxx */
        if (getpeername(STDIN_FILENO, (struct sockaddr *)&from, &fromlen) < 0) {
                syslog(LOG_ERR, "getpeername: %m");
                return EXIT_FAILURE;
        }
        if (getsockname(STDIN_FILENO, (struct sockaddr *)&local,
            &locallen) < 0) {
                syslog(LOG_ERR, "getsockname: %m");
                return EXIT_FAILURE;
        }
#if 0
        if (((struct sockaddr *)&from)->sa_family == AF_INET6 &&
            IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&from)->sin6_addr) &&
            sizeof(struct sockaddr_in) <= sizeof(from)) {
                struct sockaddr_in sin;
                struct sockaddr_in6 *sin6;
                const int off = sizeof(struct sockaddr_in6) -
                    sizeof(struct sockaddr_in);

                sin6 = (struct sockaddr_in6 *)&from;
                (void)memset(&sin, 0, sizeof(sin));
                sin.sin_family = AF_INET;
                sin.sin_len = sizeof(struct sockaddr_in);
                (void)memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[off],
                    sizeof(sin.sin_addr));
                (void)memcpy(&from, &sin, sizeof(sin));
                fromlen = sin.sin_len;
        }
#else
        if (((struct sockaddr *)&from)->sa_family == AF_INET6 &&
            IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&from)->sin6_addr)) {
                char hbuf[NI_MAXHOST];
                if (getnameinfo((struct sockaddr *)&from, fromlen, hbuf,
                                sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0) {
                        strlcpy(hbuf, "invalid", sizeof(hbuf));
                }
                syslog(LOG_ERR, "malformed \"from\" address (v4 mapped, %s)",
                    hbuf);
                return EXIT_FAILURE;
        }
#endif
        if (keepalive &&
            setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE, (char *)&on,
            sizeof(on)) < 0)
                syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
        linger.l_onoff = 1;
        linger.l_linger = 60;                   /* XXX */
        if (setsockopt(STDIN_FILENO, SOL_SOCKET, SO_LINGER, (char *)&linger,
            sizeof (linger)) < 0)
                syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m");
        proto = getprotobyname("tcp");
        (void)setsockopt(STDIN_FILENO, proto->p_proto, TCP_NODELAY, &on,
            sizeof(on));
        doit((struct sockaddr *)&from, (struct sockaddr *)&local);
}

extern char     **environ;

static void
doit(struct sockaddr *fromp, struct sockaddr *localp)
{
        struct passwd *pwd, pwres;
        in_port_t port;
        struct pollfd set[2];
        int cc, pv[2], pid, s = -1;     /* XXX gcc */
        int one = 1;
        char *hostname, *errorhost = NULL;      /* XXX gcc */
        const char *cp;
        char sig, buf[BUFSIZ];
        char cmdbuf[NCARGS+1], locuser[16], remuser[16];
        char remotehost[2 * MAXHOSTNAMELEN + 1];
        char hostnamebuf[2 * MAXHOSTNAMELEN + 1];
#ifdef  LOGIN_CAP
        login_cap_t *lc;
#endif
        char naddr[NI_MAXHOST];
        char saddr[NI_MAXHOST];
        char raddr[NI_MAXHOST];
        char pbuf[NI_MAXSERV];
        int af = fromp->sa_family;
        u_int16_t *portp;
        struct addrinfo hints, *res, *res0;
        int gaierror;
        const int niflags = NI_NUMERICHOST | NI_NUMERICSERV;
        const char *errormsg = NULL, *errorstr = NULL;
        char pwbuf[1024];

        (void)signal(SIGINT, SIG_DFL);
        (void)signal(SIGQUIT, SIG_DFL);
        (void)signal(SIGTERM, SIG_DFL);
#ifdef DEBUG
        { 
                int t = open(_PATH_TTY, O_RDWR);
                if (t >= 0) {
                        ioctl(t, TIOCNOTTY, NULL);
                        (void)close(t);
                }
        }
#endif
        switch (af) {
        case AF_INET:
                portp = &((struct sockaddr_in *)fromp)->sin_port;
                break;
#ifdef INET6
        case AF_INET6:
                portp = &((struct sockaddr_in6 *)fromp)->sin6_port;
                break;
#endif
        default:
                syslog(LOG_ERR, "malformed \"from\" address (af %d)", af);
                exit(EXIT_FAILURE);
        }
        if (getnameinfo(fromp, fromp->sa_len, naddr, sizeof(naddr),
                        pbuf, sizeof(pbuf), niflags) != 0) {
                syslog(LOG_ERR, "malformed \"from\" address (af %d)", af);
                exit(EXIT_FAILURE);
        }
#ifdef IP_OPTIONS
        if (af == AF_INET) {

        u_char optbuf[BUFSIZ/3];
        socklen_t optsize = sizeof(optbuf);
        int ipproto;
        unsigned int i;
        struct protoent *ip;

        if ((ip = getprotobyname("ip")) != NULL)
                ipproto = ip->p_proto;
        else
                ipproto = IPPROTO_IP;
        if (!getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf, &optsize) &&
            optsize != 0) {
                for (i = 0; i < optsize;) {
                        u_char c = optbuf[i];
                        if (c == IPOPT_LSRR || c == IPOPT_SSRR) {
                                syslog(LOG_NOTICE,
                                    "Connection refused from %s "
                                    "with IP option %s",
                                    inet_ntoa((
                                    (struct sockaddr_in *)fromp)->sin_addr),
                                    c == IPOPT_LSRR ? "LSRR" : "SSRR");
                                exit(EXIT_FAILURE);
                        }
                        if (c == IPOPT_EOL)
                                break;
                        i += (c == IPOPT_NOP) ? 1 : optbuf[i + 1];
                }
        }
        }
#endif
        if (ntohs(*portp) >= IPPORT_RESERVED
            || ntohs(*portp) < IPPORT_RESERVED / 2) {
                syslog(LOG_NOTICE|LOG_AUTH,
                    "Connection from %s on illegal port %u",
                    naddr, ntohs(*portp));
                exit(EXIT_FAILURE);
        }

        (void) alarm(60);
        port = 0;
        for (;;) {
                char c;

                if ((cc = read(STDIN_FILENO, &c, 1)) != 1) {
                        if (cc < 0)
                                syslog(LOG_ERR, "read: %m");
                        (void)shutdown(0, SHUT_RDWR);
                        exit(EXIT_FAILURE);
                }
                if (c == 0)
                        break;
                port = port * 10 + c - '0';
        }

        (void) alarm(0);
        if (port != 0) {
                int lport = IPPORT_RESERVED - 1;
                s = rresvport_af_addr(&lport, af, localp);
                if (s < 0) {
                        syslog(LOG_ERR, "can't get stderr port: %m");
                        exit(EXIT_FAILURE);
                }
                if (port >= IPPORT_RESERVED) {
                        syslog(LOG_ERR, "2nd port not reserved");
                        exit(EXIT_FAILURE);
                }
                *portp = htons(port);
                if (connect(s, fromp, fromp->sa_len) < 0) {
                        syslog(LOG_ERR, "connect second port %d: %m", port);
                        exit(EXIT_FAILURE);
                }
        }


#ifdef notdef
        /* from inetd, socket is already on 0, 1, 2 */
        (void)dup2(f, STDIN_FILENO);
        (void)dup2(f, STDOUT_FILENO);
        (void)dup2(f, STDERR_FILENO);
#endif
        if (getnameinfo(fromp, fromp->sa_len, saddr, sizeof(saddr),
                        NULL, 0, NI_NAMEREQD) == 0) {
                /*
                 * If name returned by getnameinfo is in our domain,
                 * attempt to verify that we haven't been fooled by someone
                 * in a remote net; look up the name and check that this
                 * address corresponds to the name.
                 */
                hostname = saddr;
                res0 = NULL;
                if (check_all || local_domain(saddr)) {
                        (void)strlcpy(remotehost, saddr, sizeof(remotehost));
                        errorhost = remotehost;
                        (void)memset(&hints, 0, sizeof(hints));
                        hints.ai_family = fromp->sa_family;
                        hints.ai_socktype = SOCK_STREAM;
                        hints.ai_flags = AI_CANONNAME;
                        gaierror = getaddrinfo(remotehost, pbuf, &hints, &res0);
                        if (gaierror) {
                                syslog(LOG_NOTICE,
                                    "Couldn't look up address for %s: %s",
                                    remotehost, gai_strerror(gaierror));
                                errorstr =
                                "Couldn't look up address for your host (%s)\n";
                                hostname = naddr;
                        } else {
                                for (res = res0; res; res = res->ai_next) {
                                        if (res->ai_family != fromp->sa_family)
                                                continue;
                                        if (res->ai_addrlen != fromp->sa_len)
                                                continue;
                                        if (getnameinfo(res->ai_addr,
                                                res->ai_addrlen,
                                                raddr, sizeof(raddr), NULL, 0,
                                                niflags) == 0
                                         && strcmp(naddr, raddr) == 0) {
                                                hostname = res->ai_canonname
                                                        ? res->ai_canonname
                                                        : saddr;
                                                break;
                                        }
                                }
                                if (res == NULL) {
                                        syslog(LOG_NOTICE,
                                          "Host addr %s not listed for host %s",
                                            naddr, res0->ai_canonname
                                                    ? res0->ai_canonname
                                                    : saddr);
                                        errorstr =
                                            "Host address mismatch for %s\n";
                                        hostname = naddr;
                                }
                        }
                }
                (void)strlcpy(hostnamebuf, hostname, sizeof(hostnamebuf));
                hostname = hostnamebuf;
                if (res0)
                        freeaddrinfo(res0);
        } else {
                (void)strlcpy(hostnamebuf, naddr, sizeof(hostnamebuf));
                errorhost = hostname = hostnamebuf;
        }

        (void)alarm(60);
        getstr(remuser, sizeof(remuser), "remuser");
        getstr(locuser, sizeof(locuser), "locuser");
        getstr(cmdbuf, sizeof(cmdbuf), "command");
        (void)alarm(0);

#ifdef USE_PAM
        pam_err = pam_start("rsh", locuser, &pamc, &pamh);
        if (pam_err != PAM_SUCCESS) {
                syslog(LOG_ERR|LOG_AUTH, "pam_start(): %s",
                    pam_strerror(pamh, pam_err));
                rshd_errx(EXIT_FAILURE, incorrect);
        }

        if ((pam_err = pam_set_item(pamh, PAM_RUSER, remuser)) != PAM_SUCCESS ||
            (pam_err = pam_set_item(pamh, PAM_RHOST, hostname)) != PAM_SUCCESS){
                syslog(LOG_ERR|LOG_AUTH, "pam_set_item(): %s",
                    pam_strerror(pamh, pam_err));
                rshd_errx(EXIT_FAILURE, incorrect);
        }

        pam_err = pam_authenticate(pamh, 0);
        if (pam_err == PAM_SUCCESS) {
                if ((pam_err = pam_get_user(pamh, &cp, NULL)) == PAM_SUCCESS) {
                        (void)strlcpy(locuser, cp, sizeof(locuser));
                        /* XXX truncation! */
                }
                pam_err = pam_acct_mgmt(pamh, 0);
        }
        if (pam_err != PAM_SUCCESS) {
                errorstr = incorrect;
                errormsg = pam_strerror(pamh, pam_err);
                goto badlogin;
        }
#endif /* USE_PAM */
        setpwent();
        if (getpwnam_r(locuser, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
            pwd == NULL) {
                syslog(LOG_INFO|LOG_AUTH,
                    "%s@%s as %s: unknown login. cmd='%.80s'",
                    remuser, hostname, locuser, cmdbuf);
                if (errorstr == NULL)
                        errorstr = "Permission denied.";
                rshd_errx(EXIT_FAILURE, errorstr, errorhost);
        }
#ifdef LOGIN_CAP
        lc = login_getclass(pwd ? pwd->pw_class : NULL);
#endif  

        if (chdir(pwd->pw_dir) < 0) {
                if (chdir("/") < 0
#ifdef LOGIN_CAP
                    || login_getcapbool(lc, "requirehome", pwd->pw_uid ? 1 : 0)
#endif
                ) {
                        syslog(LOG_INFO|LOG_AUTH,
                            "%s@%s as %s: no home directory. cmd='%.80s'",
                            remuser, hostname, locuser, cmdbuf);
                        rshd_errx(EXIT_SUCCESS, "No remote home directory.");
                }
        }

#ifndef USE_PAM
        if (errorstr ||
            (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' &&
                iruserok_sa(fromp, fromp->sa_len, pwd->pw_uid == 0, remuser,
                        locuser) < 0)) {
                errormsg = __rcmd_errstr ? __rcmd_errstr : "unknown error";
                if (errorstr == NULL)
                        errorstr = "Permission denied.";
                goto badlogin;
        }

        if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK))
                rshd_errx(EXIT_FAILURE, "Logins currently disabled.");
#endif

#ifdef LOGIN_CAP
        /*
         * PAM modules might add supplementary groups in
         * pam_setcred(), so initialize them first.
         * But we need to open the session as root.
         */
        if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) {
                syslog(LOG_ERR, "setusercontext: %m");
                exit(EXIT_FAILURE);
        }
#else
        initgroups(pwd->pw_name, pwd->pw_gid);
#endif

#ifdef USE_PAM
        if ((pam_err = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
                syslog(LOG_ERR, "pam_open_session: %s",
                    pam_strerror(pamh, pam_err));
        } else if ((pam_err = pam_setcred(pamh, PAM_ESTABLISH_CRED))
            != PAM_SUCCESS) {
                syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, pam_err));
        }
#endif

        (void)write(STDERR_FILENO, "\0", 1);
        sent_null = 1;

        if (port) {
                if (pipe(pv) < 0)
                        rshd_errx(EXIT_FAILURE, "Can't make pipe. (%s)",
                            strerror(errno));
                pid = fork();
                if (pid == -1)
                        rshd_errx(EXIT_FAILURE, "Can't fork. (%s)",
                            strerror(errno));
                if (pid) {
                        (void)close(STDIN_FILENO);
                        (void)close(STDOUT_FILENO);
                        (void)close(STDERR_FILENO);
                        (void)close(pv[1]);

                        set[0].fd = s;
                        set[0].events = POLLIN;
                        set[1].fd = pv[0];
                        set[1].events = POLLIN;
                        ioctl(pv[0], FIONBIO, (char *)&one);

                        /* should set s nbio! */
                        do {
                                if (poll(set, 2, INFTIM) < 0)
                                        break;
                                if (set[0].revents & POLLIN) {
                                        int     ret;

                                        ret = read(s, &sig, 1);
                                        if (ret <= 0)
                                                set[0].events = 0;
                                        else
                                                killpg(pid, sig);
                                }
                                if (set[1].revents & POLLIN) {
                                        errno = 0;
                                        cc = read(pv[0], buf, sizeof(buf));
                                        if (cc <= 0) {
                                                shutdown(s, SHUT_RDWR);
                                                set[1].events = 0;
                                        } else {
                                                (void)write(s, buf, cc);
                                        }
                                }

                        } while ((set[0].revents | set[1].revents) & POLLIN);
                        PAM_END;
                        exit(EXIT_SUCCESS);
                }
                (void)close(s);
                (void)close(pv[0]);
                (void)dup2(pv[1], STDERR_FILENO);
                close(pv[1]);
        }
#ifdef USE_PAM
        else {
                pid = fork();
                if (pid == -1)
                        rshd_errx(EXIT_FAILURE, "Can't fork. (%s)",
                            strerror(errno));
                if (pid) {
                        pid_t xpid;
                        int status;
                        if ((xpid = waitpid(pid, &status, 0)) != pid) {
                                pam_err = pam_close_session(pamh, 0);
                                if (pam_err != PAM_SUCCESS) {
                                        syslog(LOG_ERR,
                                            "pam_close_session: %s",
                                            pam_strerror(pamh, pam_err));
                                }
                                PAM_END;
                                if (xpid != -1)
                                        syslog(LOG_WARNING,
                                            "wrong PID: %d != %d", pid, xpid);
                                else
                                        syslog(LOG_WARNING,
                                            "wait pid=%d failed %m", pid);
                                exit(EXIT_FAILURE);
                        }
                        exit(EXIT_SUCCESS);
                }
        }
#endif

#ifdef F_CLOSEM
        (void)fcntl(STDERR_FILENO + 1, F_CLOSEM, 0);
#else
        for (fd = getdtablesize(); fd > STDERR_FILENO; fd--)
                (void)close(fd);
#endif
        if (setsid() == -1)
                syslog(LOG_ERR, "setsid() failed: %m");
#ifdef USE_PAM
        if (setlogin(pwd->pw_name) < 0)
                syslog(LOG_ERR, "setlogin() failed: %m");

        if (*pwd->pw_shell == '\0')
                pwd->pw_shell = __UNCONST(_PATH_BSHELL);

        (void)pam_setenv(pamh, "HOME", pwd->pw_dir, 1);
        (void)pam_setenv(pamh, "SHELL", pwd->pw_shell, 1);
        (void)pam_setenv(pamh, "USER", pwd->pw_name, 1);
        (void)pam_setenv(pamh, "PATH", _PATH_DEFPATH, 1);
        environ = pam_getenvlist(pamh);
        (void)pam_end(pamh, pam_err);
#else
#ifdef LOGIN_CAP
        {
                char *sh;
                if ((sh = login_getcapstr(lc, "shell", NULL, NULL))) {
                        if(!(sh = strdup(sh))) {
                                syslog(LOG_ERR, "Cannot alloc mem");
                                exit(EXIT_FAILURE);
                        }
                        pwd->pw_shell = sh;
                }
        }
#endif
{
        static char *envinit[] = { NULL };
        environ = envinit;
}
        setenv("PATH", _PATH_DEFPATH, 1);
        setenv("HOME", pwd->pw_dir, 1);
        setenv("SHELL", pwd->pw_shell, 1);
        setenv("USER", pwd->pw_name, 1);
#endif

        cp = strrchr(pwd->pw_shell, '/');
        if (cp)
                cp++;
        else
                cp = pwd->pw_shell;

#ifdef LOGIN_CAP
        if (setusercontext(lc, pwd, pwd->pw_uid,
                LOGIN_SETALL & ~LOGIN_SETGROUP) < 0) {
                syslog(LOG_ERR, "setusercontext(): %m");
                exit(EXIT_FAILURE);
        }
        login_close(lc);
#else
        (void)setgid((gid_t)pwd->pw_gid);
        (void)setuid((uid_t)pwd->pw_uid);
#endif
        endpwent();
        if (log_success || pwd->pw_uid == 0) {
                syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'",
                    remuser, hostname, locuser, cmdbuf);
        }
        (void)execl(pwd->pw_shell, cp, "-c", cmdbuf, NULL);
        rshd_errx(EXIT_FAILURE, "%s: %s", pwd->pw_shell, strerror(errno));
badlogin:
        syslog(LOG_INFO|LOG_AUTH,
            "%s@%s as %s: permission denied (%s). cmd='%.80s'",
            remuser, hostname, locuser, errormsg, cmdbuf);
        rshd_errx(EXIT_FAILURE, errorstr, errorhost);
}

/*
 * Report error to client.  Note: can't be used until second socket has
 * connected to client, or older clients will hang waiting for that
 * connection first.
 */

#include <stdarg.h>

static void
rshd_errx(int error, const char *fmt, ...)
{
        va_list ap;
        int len, rv;
        char *bp, buf[BUFSIZ];
        va_start(ap, fmt);
        bp = buf;
        if (sent_null == 0) {
                *bp++ = 1;
                len = 1;
        } else
                len = 0;
        rv = vsnprintf(bp, sizeof(buf) - 2, fmt, ap);
        bp[rv++] = '\n';
        (void)write(STDERR_FILENO, buf, len + rv);
        va_end(ap);
        exit(error);
}

static void
getstr(char *buf, int cnt, const char *err)
{
        char c;

        do {
                if (read(STDIN_FILENO, &c, 1) != 1)
                        exit(EXIT_FAILURE);
                *buf++ = c;
                if (--cnt == 0)
                        rshd_errx(EXIT_FAILURE, "%s too long", err);
        } while (c != 0);
}

/*
 * Check whether host h is in our local domain,
 * defined as sharing the last two components of the domain part,
 * or the entire domain part if the local domain has only one component.
 * If either name is unqualified (contains no '.'),
 * assume that the host is local, as it will be
 * interpreted as such.
 */
static int
local_domain(char *h)
{
        char localhost[MAXHOSTNAMELEN + 1];
        char *p1, *p2;

        localhost[0] = 0;
        (void)gethostname(localhost, sizeof(localhost));
        localhost[sizeof(localhost) - 1] = '\0';
        p1 = topdomain(localhost);
        p2 = topdomain(h);
        if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2))
                return (1);
        return (0);
}

static char *
topdomain(char *h)
{
        char *p, *maybe = NULL;
        int dots = 0;

        for (p = h + strlen(h); p >= h; p--) {
                if (*p == '.') {
                        if (++dots == 2)
                                return (p);
                        maybe = p;
                }
        }
        return (maybe);
}

static void
usage(void)
{

        syslog(LOG_ERR, "Usage: %s [-%s]", getprogname(), OPTIONS);
        exit(EXIT_FAILURE);
}