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freebsd-dev/libexec/rshd/rshd.c
Peter Wemm 5328c7eb7e As previously threatened, clean up the rshd -a option and make it default 
on rshd and rlogind.  However, note that:
1: rshd used to drop a connection with -a if the hostname != ip address.
   This is unneeded, because iruserok() does it's own checking.
   It was also wrong if .rhosts had an explicit IP address in it,
   connections would be dropped from that host solely because the DNS was
   mismatched even though it was explicitly intended to work by IP address.
2: rlogind and rshd check the hostname mappings by default now because that
   is what goes into the utmp/wtmp and logs.  If the hostname != ip address,
   then it uses the IP address for logging/utmp/wtmp purposes.  There isn't
   much point logging ficticious hostnames.
3: rshd -a is now accepted (but ignored) for compatability.  If you really
   want to make life miserable for people with bad reverse DNS, use tcpd in
   paranoid mode (which is questionable anyway, given DNS ttl tweaking).
1998-12-16 07:20:45 +00:00

847 lines
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/*-
* 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. 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) 1988, 1989, 1992, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static const char sccsid[] = "@(#)rshd.c 8.2 (Berkeley) 4/6/94";
#endif
static const char rcsid[] =
"$Id: rshd.c,v 1.22 1998/12/01 23:27:24 dg Exp $";
#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>
#ifdef LOGIN_CAP
#include <login_cap.h>
#endif
int keepalive = 1;
int log_success; /* If TRUE, log all successful accesses */
int sent_null;
int no_delay;
void doit __P((struct sockaddr_in *));
void error __P((const char *, ...));
void getstr __P((char *, int, char *));
int local_domain __P((char *));
char *topdomain __P((char *));
void usage __P((void));
#ifdef KERBEROS
#include <des.h>
#include <krb.h>
#define VERSION_SIZE 9
#define SECURE_MESSAGE "This rsh session is using DES encryption for all transmissions.\r\n"
#define OPTIONS "alnkvxDL"
char authbuf[sizeof(AUTH_DAT)];
char tickbuf[sizeof(KTEXT_ST)];
int doencrypt, use_kerberos, vacuous;
Key_schedule schedule;
#else
#define OPTIONS "alnDL"
#endif
int
main(argc, argv)
int argc;
char *argv[];
{
extern int __check_rhosts_file;
struct linger linger;
int ch, on = 1, fromlen;
struct sockaddr_in from;
openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON);
opterr = 0;
while ((ch = getopt(argc, argv, OPTIONS)) != -1)
switch (ch) {
case 'a':
/* ignored for compatability */
break;
case 'l':
__check_rhosts_file = 0;
break;
case 'n':
keepalive = 0;
break;
#ifdef KERBEROS
case 'k':
use_kerberos = 1;
break;
case 'v':
vacuous = 1;
break;
#ifdef CRYPT
case 'x':
doencrypt = 1;
break;
#endif
#endif
case 'D':
no_delay = 1;
break;
case 'L':
log_success = 1;
break;
case '?':
default:
usage();
break;
}
argc -= optind;
argv += optind;
#ifdef KERBEROS
if (use_kerberos && vacuous) {
syslog(LOG_ERR, "only one of -k and -v allowed");
exit(2);
}
#ifdef CRYPT
if (doencrypt && !use_kerberos) {
syslog(LOG_ERR, "-k is required for -x");
exit(2);
}
#endif
#endif
fromlen = sizeof (from);
if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
syslog(LOG_ERR, "getpeername: %m");
exit(1);
}
if (keepalive &&
setsockopt(0, 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(0, SOL_SOCKET, SO_LINGER, (char *)&linger,
sizeof (linger)) < 0)
syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m");
if (no_delay &&
setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0)
syslog(LOG_WARNING, "setsockopt (TCP_NODELAY): %m");
doit(&from);
/* NOTREACHED */
return(0);
}
char username[20] = "USER=";
char homedir[64] = "HOME=";
char shell[64] = "SHELL=";
char path[100] = "PATH=";
char *envinit[] =
{homedir, shell, path, username, 0};
char **environ;
void
doit(fromp)
struct sockaddr_in *fromp;
{
extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */
struct hostent *hp;
struct passwd *pwd;
u_short port;
fd_set ready, readfrom;
int cc, nfd, pv[2], pid, s;
int one = 1;
char *hostname, *errorstr;
char *cp, sig, buf[BUFSIZ];
char cmdbuf[NCARGS+1], locuser[16], remuser[16];
char fromhost[2 * MAXHOSTNAMELEN + 1];
#ifdef LOGIN_CAP
login_cap_t *lc;
#endif
#ifdef KERBEROS
AUTH_DAT *kdata = (AUTH_DAT *) NULL;
KTEXT ticket = (KTEXT) NULL;
char instance[INST_SZ], version[VERSION_SIZE];
struct sockaddr_in fromaddr;
int rc;
long authopts;
int pv1[2], pv2[2];
fd_set wready, writeto;
fromaddr = *fromp;
#endif
(void) signal(SIGINT, SIG_DFL);
(void) signal(SIGQUIT, SIG_DFL);
(void) signal(SIGTERM, SIG_DFL);
#ifdef DEBUG
{ int t = open(_PATH_TTY, 2);
if (t >= 0) {
ioctl(t, TIOCNOTTY, (char *)0);
(void) close(t);
}
}
#endif
fromp->sin_port = ntohs((u_short)fromp->sin_port);
if (fromp->sin_family != AF_INET) {
syslog(LOG_ERR, "malformed \"from\" address (af %d)",
fromp->sin_family);
exit(1);
}
#ifdef IP_OPTIONS
{
u_char optbuf[BUFSIZ/3];
int optsize = sizeof(optbuf), ipproto, 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(fromp->sin_addr),
c == IPOPT_LSRR ? "LSRR" : "SSRR");
exit(1);
}
if (c == IPOPT_EOL)
break;
i += (c == IPOPT_NOP) ? 1 : optbuf[i+1];
}
}
}
#endif
#ifdef KERBEROS
if (!use_kerberos)
#endif
if (fromp->sin_port >= IPPORT_RESERVED ||
fromp->sin_port < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE|LOG_AUTH,
"connection from %s on illegal port %u",
inet_ntoa(fromp->sin_addr),
fromp->sin_port);
exit(1);
}
(void) alarm(60);
port = 0;
s = 0; /* not set or used if port == 0 */
for (;;) {
char c;
if ((cc = read(STDIN_FILENO, &c, 1)) != 1) {
if (cc < 0)
syslog(LOG_NOTICE, "read: %m");
shutdown(0, 1+1);
exit(1);
}
if (c == 0)
break;
port = port * 10 + c - '0';
}
(void) alarm(0);
if (port != 0) {
int lport = IPPORT_RESERVED - 1;
s = rresvport(&lport);
if (s < 0) {
syslog(LOG_ERR, "can't get stderr port: %m");
exit(1);
}
#ifdef KERBEROS
if (!use_kerberos)
#endif
if (port >= IPPORT_RESERVED ||
port < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE|LOG_AUTH,
"2nd socket from %s on unreserved port %u",
inet_ntoa(fromp->sin_addr),
port);
exit(1);
}
fromp->sin_port = htons(port);
if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) {
syslog(LOG_INFO, "connect second port %d: %m", port);
exit(1);
}
}
#ifdef KERBEROS
if (vacuous) {
error("rshd: remote host requires Kerberos authentication\n");
exit(1);
}
#endif
#ifdef notdef
/* from inetd, socket is already on 0, 1, 2 */
dup2(f, 0);
dup2(f, 1);
dup2(f, 2);
#endif
errorstr = NULL;
strncpy(fromhost, inet_ntoa(fromp->sin_addr),
sizeof(fromhost) - 1);
hostname = fromhost;
hp = gethostbyaddr((char *)&fromp->sin_addr, sizeof (struct in_addr),
fromp->sin_family);
if (hp) {
/*
* OK, it looks like a DNS name is attached.. Lets see if
* it looks like we can use it. If it doesn't check out,
* ditch it and use the IP address for logging instead.
* Note that iruserok() does it's own hostname checking!!
*/
strncpy(fromhost, hp->h_name, sizeof(fromhost) - 1);
fromhost[sizeof(fromhost) - 1] = 0;
hp = gethostbyname(fromhost);
if (hp == NULL) {
strncpy(fromhost, inet_ntoa(fromp->sin_addr),
sizeof(fromhost) - 1);
} else for (; ; hp->h_addr_list++) {
if (hp->h_addr_list[0] == NULL) {
/* End of list - ditch it */
strncpy(fromhost, inet_ntoa(fromp->sin_addr),
sizeof(fromhost) - 1);
break;
}
if (!bcmp(hp->h_addr_list[0],
(caddr_t)&fromp->sin_addr,
sizeof(fromp->sin_addr)))
break; /* OK! */
}
}
fromhost[sizeof(fromhost) - 1] = 0;
#ifdef KERBEROS
if (use_kerberos) {
kdata = (AUTH_DAT *) authbuf;
ticket = (KTEXT) tickbuf;
authopts = 0L;
strcpy(instance, "*");
version[VERSION_SIZE - 1] = '\0';
#ifdef CRYPT
if (doencrypt) {
struct sockaddr_in local_addr;
rc = sizeof(local_addr);
if (getsockname(0, (struct sockaddr *)&local_addr,
&rc) < 0) {
syslog(LOG_ERR, "getsockname: %m");
error("rlogind: getsockname: %m");
exit(1);
}
authopts = KOPT_DO_MUTUAL;
rc = krb_recvauth(authopts, 0, ticket,
"rcmd", instance, &fromaddr,
&local_addr, kdata, "", schedule,
version);
des_set_key(&kdata->session, schedule);
} else
#endif
rc = krb_recvauth(authopts, 0, ticket, "rcmd",
instance, &fromaddr,
(struct sockaddr_in *) 0,
kdata, "", NULL, version);
if (rc != KSUCCESS) {
error("Kerberos authentication failure: %s\n",
krb_err_txt[rc]);
exit(1);
}
} else
#endif
getstr(remuser, sizeof(remuser), "remuser");
getstr(locuser, sizeof(locuser), "locuser");
getstr(cmdbuf, sizeof(cmdbuf), "command");
setpwent();
pwd = getpwnam(locuser);
if (pwd == NULL) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: unknown login. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
if (errorstr == NULL)
errorstr = "Login incorrect.\n";
goto fail;
}
#ifdef LOGIN_CAP
lc = login_getpwclass(pwd);
#endif
if (chdir(pwd->pw_dir) < 0) {
#ifdef LOGIN_CAP
if (chdir("/") < 0 ||
login_getcapbool(lc, "requirehome", !!pwd->pw_uid)) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: no home directory. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
error("No remote home directory.\n");
exit(0);
}
#else
(void) chdir("/");
#ifdef notdef
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: no home directory. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
error("No remote directory.\n");
exit(1);
#endif
#endif
pwd->pw_dir = "/";
}
#ifdef KERBEROS
if (use_kerberos) {
if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0') {
if (kuserok(kdata, locuser) != 0) {
syslog(LOG_INFO|LOG_AUTH,
"Kerberos rsh denied to %s.%s@%s",
kdata->pname, kdata->pinst, kdata->prealm);
error("Login incorrect.\n");
exit(1);
}
}
} else
#endif
if (errorstr ||
(pwd->pw_expire && time(NULL) >= pwd->pw_expire) ||
(pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' &&
iruserok(fromp->sin_addr.s_addr, pwd->pw_uid == 0,
remuser, locuser) < 0)) {
if (__rcmd_errstr)
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied (%s). cmd='%.80s'",
remuser, hostname, locuser, __rcmd_errstr,
cmdbuf);
else
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
fail:
if (errorstr == NULL)
errorstr = "Login incorrect.\n";
error(errorstr, hostname);
exit(1);
}
if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK)) {
error("Logins currently disabled.\n");
exit(1);
}
#ifdef LOGIN_CAP
if (lc != NULL) {
char remote_ip[MAXHOSTNAMELEN];
strncpy(remote_ip, inet_ntoa(fromp->sin_addr),
sizeof(remote_ip) - 1);
remote_ip[sizeof(remote_ip) - 1] = 0;
if (!auth_hostok(lc, fromhost, remote_ip)) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied (%s). cmd='%.80s'",
remuser, hostname, locuser, __rcmd_errstr,
cmdbuf);
error("Login incorrect.\n");
exit(1);
}
if (!auth_timeok(lc, time(NULL))) {
error("Logins not available right now\n");
exit(1);
}
}
#endif /* !LOGIN_CAP */
#if BSD > 43
/* before fork, while we're session leader */
if (setlogin(pwd->pw_name) < 0)
syslog(LOG_ERR, "setlogin() failed: %m");
#endif
(void) write(STDERR_FILENO, "\0", 1);
sent_null = 1;
if (port) {
if (pipe(pv) < 0) {
error("Can't make pipe.\n");
exit(1);
}
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt) {
if (pipe(pv1) < 0) {
error("Can't make 2nd pipe.\n");
exit(1);
}
if (pipe(pv2) < 0) {
error("Can't make 3rd pipe.\n");
exit(1);
}
}
#endif
#endif
pid = fork();
if (pid == -1) {
error("Can't fork; try again.\n");
exit(1);
}
if (pid) {
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt) {
static char msg[] = SECURE_MESSAGE;
(void) close(pv1[1]);
(void) close(pv2[1]);
des_enc_write(s, msg, sizeof(msg) - 1,
schedule, &kdata->session);
} else
#endif
#endif
{
(void) close(0);
(void) close(1);
}
(void) close(2);
(void) close(pv[1]);
FD_ZERO(&readfrom);
FD_SET(s, &readfrom);
FD_SET(pv[0], &readfrom);
if (pv[0] > s)
nfd = pv[0];
else
nfd = s;
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt) {
FD_ZERO(&writeto);
FD_SET(pv2[0], &writeto);
FD_SET(pv1[0], &readfrom);
nfd = MAX(nfd, pv2[0]);
nfd = MAX(nfd, pv1[0]);
} else
#endif
#endif
ioctl(pv[0], FIONBIO, (char *)&one);
/* should set s nbio! */
nfd++;
do {
ready = readfrom;
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt) {
wready = writeto;
if (select(nfd, &ready,
&wready, (fd_set *) 0,
(struct timeval *) 0) < 0)
break;
} else
#endif
#endif
if (select(nfd, &ready, (fd_set *)0,
(fd_set *)0, (struct timeval *)0) < 0)
break;
if (FD_ISSET(s, &ready)) {
int ret;
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt)
ret = des_enc_read(s, &sig, 1,
schedule, &kdata->session);
else
#endif
#endif
ret = read(s, &sig, 1);
if (ret <= 0)
FD_CLR(s, &readfrom);
else
killpg(pid, sig);
}
if (FD_ISSET(pv[0], &ready)) {
errno = 0;
cc = read(pv[0], buf, sizeof(buf));
if (cc <= 0) {
shutdown(s, 1+1);
FD_CLR(pv[0], &readfrom);
} else {
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt)
(void)
des_enc_write(s, buf, cc,
schedule, &kdata->session);
else
#endif
#endif
(void)
write(s, buf, cc);
}
}
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt && FD_ISSET(pv1[0], &ready)) {
errno = 0;
cc = read(pv1[0], buf, sizeof(buf));
if (cc <= 0) {
shutdown(pv1[0], 1+1);
FD_CLR(pv1[0], &readfrom);
} else
(void) des_enc_write(STDOUT_FILENO,
buf, cc,
schedule, &kdata->session);
}
if (doencrypt && FD_ISSET(pv2[0], &wready)) {
errno = 0;
cc = des_enc_read(STDIN_FILENO,
buf, sizeof(buf),
schedule, &kdata->session);
if (cc <= 0) {
shutdown(pv2[0], 1+1);
FD_CLR(pv2[0], &writeto);
} else
(void) write(pv2[0], buf, cc);
}
#endif
#endif
} while (FD_ISSET(s, &readfrom) ||
#ifdef CRYPT
#ifdef KERBEROS
(doencrypt && FD_ISSET(pv1[0], &readfrom)) ||
#endif
#endif
FD_ISSET(pv[0], &readfrom));
exit(0);
}
setpgrp(0, getpid());
(void) close(s);
(void) close(pv[0]);
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt) {
close(pv1[0]); close(pv2[0]);
dup2(pv1[1], 1);
dup2(pv2[1], 0);
close(pv1[1]);
close(pv2[1]);
}
#endif
#endif
dup2(pv[1], 2);
close(pv[1]);
}
if (*pwd->pw_shell == '\0')
pwd->pw_shell = _PATH_BSHELL;
environ = envinit;
strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
strcat(path, _PATH_DEFPATH);
strncat(shell, pwd->pw_shell, sizeof(shell)-7);
strncat(username, pwd->pw_name, sizeof(username)-6);
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) != 0) {
syslog(LOG_ERR, "setusercontext: %m");
exit(1);
}
login_close(lc);
#else
(void) setgid((gid_t)pwd->pw_gid);
initgroups(pwd->pw_name, pwd->pw_gid);
(void) setuid((uid_t)pwd->pw_uid);
#endif
endpwent();
if (log_success || pwd->pw_uid == 0) {
#ifdef KERBEROS
if (use_kerberos)
syslog(LOG_INFO|LOG_AUTH,
"Kerberos shell from %s.%s@%s on %s as %s, cmd='%.80s'",
kdata->pname, kdata->pinst, kdata->prealm,
hostname, locuser, cmdbuf);
else
#endif
syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
}
execl(pwd->pw_shell, cp, "-c", cmdbuf, 0);
perror(pwd->pw_shell);
exit(1);
}
/*
* 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.
*/
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
void
#if __STDC__
error(const char *fmt, ...)
#else
error(fmt, va_alist)
char *fmt;
va_dcl
#endif
{
va_list ap;
int len;
char *bp, buf[BUFSIZ];
#if __STDC__
va_start(ap, fmt);
#else
va_start(ap);
#endif
bp = buf;
if (sent_null == 0) {
*bp++ = 1;
len = 1;
} else
len = 0;
(void)vsnprintf(bp, sizeof(buf) - 1, fmt, ap);
(void)write(STDERR_FILENO, buf, len + strlen(bp));
}
void
getstr(buf, cnt, err)
char *buf, *err;
int cnt;
{
char c;
do {
if (read(STDIN_FILENO, &c, 1) != 1)
exit(1);
*buf++ = c;
if (--cnt == 0) {
error("%s too long\n", err);
exit(1);
}
} 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.
*/
int
local_domain(h)
char *h;
{
char localhost[MAXHOSTNAMELEN];
char *p1, *p2;
localhost[0] = 0;
(void) gethostname(localhost, sizeof(localhost));
p1 = topdomain(localhost);
p2 = topdomain(h);
if (p1 == NULL || p2 == NULL || !strcasecmp(p1, p2))
return (1);
return (0);
}
char *
topdomain(h)
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);
}
void
usage()
{
syslog(LOG_ERR, "usage: rshd [-%s]", OPTIONS);
exit(2);
}
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