freebsd-dev/libexec/rshd/rshd.c
Brian Somers 7bc6d0158f Fix the type of the NULL arg to execl()
Idea from: Theo de Raadt <deraadt@openbsd.org>
2001-07-09 09:24:06 +00:00

845 lines
20 KiB
C

/*-
* 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[] =
"$FreeBSD$";
#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 <err.h>
#include <errno.h>
#include <fcntl.h>
#include <libutil.h>
#include <paths.h>
#include <pwd.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <login_cap.h>
#ifdef USE_PAM
#include <security/pam_appl.h>
#include <sys/wait.h>
static int export_pam_environment __P((void));
static int ok_to_export __P((const char *));
static pam_handle_t *pamh;
static char **environ_pam;
#define PAM_END { \
if ((retcode = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS) \
syslog(LOG_ERR|LOG_AUTH, "pam_setcred: %s", pam_strerror(pamh, retcode)); \
if ((retcode = pam_close_session(pamh,0)) != PAM_SUCCESS) \
syslog(LOG_ERR|LOG_AUTH, "pam_close_session: %s", pam_strerror(pamh, retcode)); \
if ((retcode = pam_end(pamh, retcode)) != PAM_SUCCESS) \
syslog(LOG_ERR|LOG_AUTH, "pam_end: %s", pam_strerror(pamh, retcode)); \
}
#endif /* USE_PAM */
/* wrapper for KAME-special getnameinfo() */
#ifndef NI_WITHSCOPEID
#define NI_WITHSCOPEID 0
#endif
int keepalive = 1;
int log_success; /* If TRUE, log all successful accesses */
int sent_null;
int no_delay;
#ifdef CRYPT
int doencrypt = 0;
#endif
union sockunion {
struct sockinet {
u_char si_len;
u_char si_family;
u_short si_port;
} su_si;
struct sockaddr_in su_sin;
struct sockaddr_in6 su_sin6;
};
#define su_len su_si.si_len
#define su_family su_si.si_family
#define su_port su_si.si_port
void doit __P((union sockunion *));
static void rshd_errx __P((int, const char *, ...));
void getstr __P((char *, int, char *));
int local_domain __P((char *));
char *topdomain __P((char *));
void usage __P((void));
#define OPTIONS "alnDL"
int
main(argc, argv)
int argc;
char *argv[];
{
extern int __check_rhosts_file;
struct linger linger;
int ch, on = 1, fromlen;
struct sockaddr_storage from;
openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON);
opterr = 0;
while ((ch = getopt(argc, argv, OPTIONS)) != -1)
switch (ch) {
case 'a':
/* ignored for compatibility */
break;
case 'l':
__check_rhosts_file = 0;
break;
case 'n':
keepalive = 0;
break;
#ifdef CRYPT
case 'x':
doencrypt = 1;
break;
#endif
case 'D':
no_delay = 1;
break;
case 'L':
log_success = 1;
break;
case '?':
default:
usage();
break;
}
argc -= optind;
argv += optind;
#ifdef CRYPT
if (doencrypt) {
syslog(LOG_ERR, "-k is required for -x");
exit(2);
}
#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((union sockunion *)&from);
/* NOTREACHED */
return(0);
}
#ifdef USE_PAM
/*
* We can't have a conversation with the client over the rsh connection.
* You must use auth methods that don't require one, like pam_rhosts.
*/
int null_conv(int num_msg, const struct pam_message **msg,
struct pam_response **resp, void *appdata_ptr)
{
syslog(LOG_ERR, "PAM conversation is not supported");
return PAM_CONV_ERR;
}
#endif /* USE_PAM */
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)
union sockunion *fromp;
{
extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */
struct passwd *pwd;
u_short port;
fd_set ready, readfrom;
int cc, nfd, pv[2], pid, s;
int one = 1;
char *errorstr;
char *cp, sig, buf[BUFSIZ];
char cmdbuf[NCARGS+1], locuser[16], remuser[16];
char fromhost[2 * MAXHOSTNAMELEN + 1];
char numericname[INET6_ADDRSTRLEN];
int af = fromp->su_family, err;
#ifdef CRYPT
int rc;
int pv1[2], pv2[2];
#endif
login_cap_t *lc;
#ifdef USE_PAM
static struct pam_conv conv = { null_conv, NULL };
int retcode;
#endif /* USE_PAM */
(void) signal(SIGINT, SIG_DFL);
(void) signal(SIGQUIT, SIG_DFL);
(void) signal(SIGTERM, SIG_DFL);
fromp->su_port = ntohs((u_short)fromp->su_port);
if (af != AF_INET
#ifdef INET6
&& af != AF_INET6
#endif
) {
syslog(LOG_ERR, "malformed \"from\" address (af %d)", af);
exit(1);
}
err = getnameinfo((struct sockaddr *)fromp, fromp->su_len, numericname,
sizeof(numericname), NULL, 0,
NI_NUMERICHOST|NI_WITHSCOPEID);
/* XXX: do 'err' check */
#ifdef IP_OPTIONS
if (af == AF_INET) {
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",
numericname,
c == IPOPT_LSRR ? "LSRR" : "SSRR");
exit(1);
}
if (c == IPOPT_EOL)
break;
i += (c == IPOPT_NOP) ? 1 : optbuf[i+1];
}
}
}
#endif
if (fromp->su_port >= IPPORT_RESERVED ||
fromp->su_port < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE|LOG_AUTH,
"connection from %s on illegal port %u",
numericname,
fromp->su_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_af(&lport, af);
if (s < 0) {
syslog(LOG_ERR, "can't get stderr port: %m");
exit(1);
}
if (port >= IPPORT_RESERVED ||
port < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE|LOG_AUTH,
"2nd socket from %s on unreserved port %u",
numericname,
port);
exit(1);
}
fromp->su_port = htons(port);
if (connect(s, (struct sockaddr *)fromp, fromp->su_len) < 0) {
syslog(LOG_INFO, "connect second port %d: %m", port);
exit(1);
}
}
errorstr = NULL;
realhostname_sa(fromhost, sizeof(fromhost) - 1,
(struct sockaddr *)fromp,
fromp->su_len);
fromhost[sizeof(fromhost) - 1] = '\0';
#ifdef CRYPT
if (doencrypt && af == AF_INET) {
struct sockaddr_in local_addr;
rc = sizeof(local_addr);
if (getsockname(0, (struct sockaddr *)&local_addr,
&rc) < 0) {
syslog(LOG_ERR, "getsockname: %m");
rshd_errx(1, "rlogind: getsockname: %m"); /* XXX */
}
authopts = KOPT_DO_MUTUAL;
rc = krb_recvauth(authopts, 0, ticket,
"rcmd", instance, &fromaddr,
&local_addr, kdata, "", schedule,
version);
des_set_key(&kdata->session, schedule);
}
#endif
getstr(remuser, sizeof(remuser), "remuser");
getstr(locuser, sizeof(locuser), "locuser");
getstr(cmdbuf, sizeof(cmdbuf), "command");
#ifdef USE_PAM
retcode = pam_start("rsh", locuser, &conv, &pamh);
if (retcode != PAM_SUCCESS) {
syslog(LOG_ERR|LOG_AUTH, "pam_start: %s", pam_strerror(pamh, retcode));
rshd_errx(1, "Login incorrect.");
}
retcode = pam_set_item (pamh, PAM_RUSER, remuser);
if (retcode != PAM_SUCCESS) {
syslog(LOG_ERR|LOG_AUTH, "pam_set_item(PAM_RUSER): %s", pam_strerror(pamh, retcode));
rshd_errx(1, "Login incorrect.");
}
retcode = pam_set_item (pamh, PAM_RHOST, fromhost);
if (retcode != PAM_SUCCESS) {
syslog(LOG_ERR|LOG_AUTH, "pam_set_item(PAM_RHOST): %s", pam_strerror(pamh, retcode));
rshd_errx(1, "Login incorrect.");
}
retcode = pam_set_item (pamh, PAM_TTY, "tty");
if (retcode != PAM_SUCCESS) {
syslog(LOG_ERR|LOG_AUTH, "pam_set_item(PAM_TTY): %s", pam_strerror(pamh, retcode));
rshd_errx(1, "Login incorrect.");
}
retcode = pam_authenticate(pamh, 0);
if (retcode == PAM_SUCCESS) {
if ((retcode = pam_get_item(pamh, PAM_USER, (const void **) &cp)) == PAM_SUCCESS) {
strncpy(locuser, cp, sizeof(locuser));
locuser[sizeof(locuser) - 1] = '\0';
} else
syslog(LOG_ERR|LOG_AUTH, "pam_get_item(PAM_USER): %s",
pam_strerror(pamh, retcode));
retcode = pam_acct_mgmt(pamh, 0);
}
if (retcode != PAM_SUCCESS) {
syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: permission denied (%s). cmd='%.80s'",
remuser, fromhost, locuser, pam_strerror(pamh, retcode), cmdbuf);
rshd_errx(1, "Login incorrect.");
}
#endif /* USE_PAM */
setpwent();
pwd = getpwnam(locuser);
if (pwd == NULL) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: unknown login. cmd='%.80s'",
remuser, fromhost, locuser, cmdbuf);
if (errorstr == NULL)
errorstr = "Login incorrect.";
rshd_errx(1, errorstr, fromhost);
}
#ifndef USE_PAM
if (errorstr ||
(pwd->pw_expire && time(NULL) >= pwd->pw_expire) ||
iruserok_sa(fromp, fromp->su_len, 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, fromhost, locuser, __rcmd_errstr,
cmdbuf);
else
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied. cmd='%.80s'",
remuser, fromhost, locuser, cmdbuf);
if (errorstr == NULL)
errorstr = "Login incorrect.";
rshd_errx(1, errorstr, fromhost);
}
#endif /* USE_PAM */
lc = login_getpwclass(pwd);
if (pwd->pw_uid)
auth_checknologin(lc);
if (chdir(pwd->pw_dir) < 0) {
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, fromhost, locuser, cmdbuf);
rshd_errx(0, "No remote home directory.");
}
pwd->pw_dir = "/";
}
if (lc != NULL && fromp->su_family == AF_INET) { /*XXX*/
char remote_ip[MAXHOSTNAMELEN];
strncpy(remote_ip, numericname,
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, fromhost, locuser, __rcmd_errstr,
cmdbuf);
rshd_errx(1, "Login incorrect.");
}
if (!auth_timeok(lc, time(NULL)))
rshd_errx(1, "Logins not available right now");
}
#if BSD > 43
/* before fork, while we're session leader */
if (setlogin(pwd->pw_name) < 0)
syslog(LOG_ERR, "setlogin() failed: %m");
#endif
/*
* 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(1);
}
#ifdef USE_PAM
if ((retcode = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, retcode));
} else if ((retcode = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, retcode));
}
#endif /* USE_PAM */
(void) write(STDERR_FILENO, "\0", 1);
sent_null = 1;
if (port) {
if (pipe(pv) < 0)
rshd_errx(1, "Can't make pipe.");
#ifdef CRYPT
if (doencrypt) {
if (pipe(pv1) < 0)
rshd_errx(1, "Can't make 2nd pipe.");
if (pipe(pv2) < 0)
rshd_errx(1, "Can't make 3rd pipe.");
}
#endif
pid = fork();
if (pid == -1)
rshd_errx(1, "Can't fork; try again.");
if (pid) {
#ifdef CRYPT
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
{
(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
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
ioctl(pv[0], FIONBIO, (char *)&one);
/* should set s nbio! */
nfd++;
do {
ready = readfrom;
#ifdef CRYPT
if (doencrypt) {
wready = writeto;
if (select(nfd, &ready,
&wready, (fd_set *) 0,
(struct timeval *) 0) < 0)
break;
} else
#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
if (doencrypt)
ret = des_enc_read(s, &sig, 1,
schedule, &kdata->session);
else
#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
if (doencrypt)
(void)
des_enc_write(s, buf, cc,
schedule, &kdata->session);
else
#endif
(void)
write(s, buf, cc);
}
}
#ifdef CRYPT
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
} while (FD_ISSET(s, &readfrom) ||
#ifdef CRYPT
(doencrypt && FD_ISSET(pv1[0], &readfrom)) ||
#endif
FD_ISSET(pv[0], &readfrom));
#ifdef USE_PAM
PAM_END;
#endif /* USE_PAM */
exit(0);
}
setpgrp(0, getpid());
(void) close(s);
(void) close(pv[0]);
#ifdef CRYPT
if (doencrypt) {
close(pv1[0]); close(pv2[0]);
dup2(pv1[1], 1);
dup2(pv2[1], 0);
close(pv1[1]);
close(pv2[1]);
}
#endif
dup2(pv[1], 2);
close(pv[1]);
}
#ifdef USE_PAM
else {
pid = fork();
if (pid == -1)
rshd_errx(1, "Can't fork; try again.");
if (pid) {
/* Parent. */
wait(NULL);
PAM_END;
exit(0);
}
}
#endif /* USE_PAM */
if (*pwd->pw_shell == '\0')
pwd->pw_shell = _PATH_BSHELL;
environ = envinit;
#ifdef USE_PAM
/*
* Add any environmental variables that the
* PAM modules may have set.
*/
environ_pam = pam_getenvlist(pamh);
if (environ_pam)
export_pam_environment();
if ((retcode = pam_end(pamh, PAM_DATA_SILENT)) != PAM_SUCCESS)
syslog(LOG_ERR|LOG_AUTH, "pam_end: %s", pam_strerror(pamh, retcode));
#endif /* USE_PAM */
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;
if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETALL & ~LOGIN_SETGROUP) != 0) {
syslog(LOG_ERR, "setusercontext: %m");
exit(1);
}
login_close(lc);
endpwent();
if (log_success || pwd->pw_uid == 0) {
syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'",
remuser, fromhost, locuser, cmdbuf);
}
execl(pwd->pw_shell, cp, "-c", cmdbuf, (char *)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.
*/
static void
rshd_errx(int errcode, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
if (sent_null == 0)
write(STDERR_FILENO, "\1", 1);
verrx(errcode, fmt, ap);
/* NOTREACHED */
}
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)
rshd_errx(1, "%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.
*/
int
local_domain(h)
char *h;
{
char localhost[MAXHOSTNAMELEN];
char *p1, *p2;
localhost[0] = 0;
(void) gethostname(localhost, sizeof(localhost) - 1);
localhost[sizeof(localhost) - 1] = '\0';
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);
}
#ifdef USE_PAM
static int
export_pam_environment()
{
char **pp;
for (pp = environ_pam; *pp != NULL; pp++) {
if (ok_to_export(*pp))
(void) putenv(*pp);
free(*pp);
}
return PAM_SUCCESS;
}
/*
* Sanity checks on PAM environmental variables:
* - Make sure there is an '=' in the string.
* - Make sure the string doesn't run on too long.
* - Do not export certain variables. This list was taken from the
* Solaris pam_putenv(3) man page.
*/
static int
ok_to_export(s)
const char *s;
{
static const char *noexport[] = {
"SHELL", "HOME", "LOGNAME", "MAIL", "CDPATH",
"IFS", "PATH", NULL
};
const char **pp;
size_t n;
if (strlen(s) > 1024 || strchr(s, '=') == NULL)
return 0;
if (strncmp(s, "LD_", 3) == 0)
return 0;
for (pp = noexport; *pp != NULL; pp++) {
n = strlen(*pp);
if (s[n] == '=' && strncmp(s, *pp, n) == 0)
return 0;
}
return 1;
}
#endif /* USE_PAM */
void
usage()
{
syslog(LOG_ERR, "usage: rshd [-%s]", OPTIONS);
exit(2);
}