NetBSD/usr.bin/rsh/rsh.c

488 lines
10 KiB
C

/* $NetBSD: rsh.c,v 1.5 1997/02/16 15:01:05 mrg Exp $ */
/*-
* Copyright (c) 1983, 1990, 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 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 char sccsid[] = "from: @(#)rsh.c 8.4 (Berkeley) 4/29/95";*/
static char rcsid[] = "$NetBSD: rsh.c,v 1.5 1997/02/16 15:01:05 mrg Exp $";
#endif /* not lint */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <netdb.h>
#include <err.h>
#include <errno.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <varargs.h>
#include "pathnames.h"
#ifdef KERBEROS
#include <kerberosIV/des.h>
#include <kerberosIV/krb.h>
CREDENTIALS cred;
Key_schedule schedule;
int use_kerberos = 1, doencrypt;
char dst_realm_buf[REALM_SZ], *dest_realm;
extern char *krb_realmofhost();
#endif
/*
* rsh - remote shell
*/
int rfd2;
char *copyargs __P((char **));
void sendsig __P((int));
void talk __P((int, long, pid_t, int));
void usage __P((void));
void warning __P(());
int
main(argc, argv)
int argc;
char **argv;
{
struct passwd *pw;
struct servent *sp;
long omask;
int argoff, asrsh, ch, dflag, nflag, one, rem;
pid_t pid;
uid_t uid;
char *args, *host, *p, *user;
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;
}
#ifdef KERBEROS
#ifdef CRYPT
#define OPTIONS "8KLdek:l:nwx"
#else
#define OPTIONS "8KLdek:l:nw"
#endif
#else
#define OPTIONS "8KLdel:nw"
#endif
while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != EOF)
switch(ch) {
case 'K':
#ifdef KERBEROS
use_kerberos = 0;
#endif
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;
#ifdef KERBEROS
case 'k':
dest_realm = dst_realm_buf;
strncpy(dest_realm, optarg, REALM_SZ);
break;
#endif
case 'n':
nflag = 1;
break;
#ifdef KERBEROS
#ifdef CRYPT
case 'x':
doencrypt = 1;
des_set_key(cred.session, schedule);
break;
#endif
#endif
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");
/* Accept user1@host format, though "-l user2" overrides user1 */
p = strchr(host, '@');
if (p) {
*p = '\0';
if (!user && p > host)
user = host;
host = p + 1;
if (*host == '\0')
usage();
}
if (!user)
user = pw->pw_name;
#ifdef KERBEROS
#ifdef CRYPT
/* -x turns off -n */
if (doencrypt)
nflag = 0;
#endif
#endif
args = copyargs(argv);
sp = NULL;
#ifdef KERBEROS
if (use_kerberos) {
sp = getservbyname((doencrypt ? "ekshell" : "kshell"), "tcp");
if (sp == NULL) {
use_kerberos = 0;
warning("can't get entry for %s/tcp service",
doencrypt ? "ekshell" : "kshell");
}
}
#endif
if (sp == NULL)
sp = getservbyname("shell", "tcp");
if (sp == NULL)
errx(1, "shell/tcp: unknown service");
#ifdef KERBEROS
try_connect:
if (use_kerberos) {
struct hostent *hp;
/* fully qualify hostname (needed for krb_realmofhost) */
hp = gethostbyname(host);
if (hp != NULL && !(host = strdup(hp->h_name)))
err(1, NULL);
rem = KSUCCESS;
errno = 0;
if (dest_realm == NULL)
dest_realm = krb_realmofhost(host);
#ifdef CRYPT
if (doencrypt)
rem = krcmd_mutual(&host, sp->s_port, user, args,
&rfd2, dest_realm, &cred, schedule);
else
#endif
rem = krcmd(&host, sp->s_port, user, args, &rfd2,
dest_realm);
if (rem < 0) {
use_kerberos = 0;
sp = getservbyname("shell", "tcp");
if (sp == NULL)
errx(1, "shell/tcp: unknown service");
if (errno == ECONNREFUSED)
warning("remote host doesn't support Kerberos");
if (errno == ENOENT)
warning("can't provide Kerberos auth data");
goto try_connect;
}
} else {
if (doencrypt)
errx(1, "the -x flag requires Kerberos authentication");
rem = rcmd(&host, sp->s_port, pw->pw_name, user, args, &rfd2);
}
#else
rem = rcmd(&host, sp->s_port, pw->pw_name, user, args, &rfd2);
#endif
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");
}
#ifdef KERBEROS
#ifdef CRYPT
if (!doencrypt)
#endif
#endif
{
(void)ioctl(rfd2, FIONBIO, &one);
(void)ioctl(rem, FIONBIO, &one);
}
talk(nflag, omask, pid, rem);
if (!nflag)
(void)kill(pid, SIGKILL);
exit(0);
}
void
talk(nflag, omask, pid, rem)
int nflag;
long omask;
pid_t pid;
int rem;
{
int cc, wc;
fd_set readfrom, ready, rembits;
char *bp, buf[BUFSIZ];
if (!nflag && pid == 0) {
(void)close(rfd2);
reread: errno = 0;
if ((cc = read(0, buf, sizeof buf)) <= 0)
goto done;
bp = buf;
rewrite:
FD_ZERO(&rembits);
FD_SET(rem, &rembits);
if (select(16, 0, &rembits, 0, 0) < 0) {
if (errno != EINTR)
err(1, "select");
goto rewrite;
}
if (!FD_ISSET(rem, &rembits))
goto rewrite;
#ifdef KERBEROS
#ifdef CRYPT
if (doencrypt)
wc = des_write(rem, bp, cc);
else
#endif
#endif
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);
}
(void)sigsetmask(omask);
FD_ZERO(&readfrom);
FD_SET(rfd2, &readfrom);
FD_SET(rem, &readfrom);
do {
ready = readfrom;
if (select(16, &ready, 0, 0, 0) < 0) {
if (errno != EINTR)
err(1, "select");
continue;
}
if (FD_ISSET(rfd2, &ready)) {
errno = 0;
#ifdef KERBEROS
#ifdef CRYPT
if (doencrypt)
cc = des_read(rfd2, buf, sizeof buf);
else
#endif
#endif
cc = read(rfd2, buf, sizeof buf);
if (cc <= 0) {
if (errno != EWOULDBLOCK)
FD_CLR(rfd2, &readfrom);
} else
(void)write(2, buf, cc);
}
if (FD_ISSET(rem, &ready)) {
errno = 0;
#ifdef KERBEROS
#ifdef CRYPT
if (doencrypt)
cc = des_read(rem, buf, sizeof buf);
else
#endif
#endif
cc = read(rem, buf, sizeof buf);
if (cc <= 0) {
if (errno != EWOULDBLOCK)
FD_CLR(rem, &readfrom);
} else
(void)write(1, buf, cc);
}
} while (FD_ISSET(rfd2, &readfrom) || FD_ISSET(rem, &readfrom));
}
void
sendsig(sig)
int sig;
{
char signo;
signo = sig;
#ifdef KERBEROS
#ifdef CRYPT
if (doencrypt)
(void)des_write(rfd2, &signo, 1);
else
#endif
#endif
(void)write(rfd2, &signo, 1);
}
#ifdef KERBEROS
/* VARARGS */
void
warning(va_alist)
va_dcl
{
va_list ap;
char *fmt;
(void)fprintf(stderr, "rsh: warning, using standard rsh: ");
va_start(ap);
fmt = va_arg(ap, char *);
vfprintf(stderr, fmt, ap);
va_end(ap);
(void)fprintf(stderr, ".\n");
}
#endif
char *
copyargs(argv)
char **argv;
{
int cc;
char **ap, *args, *p;
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)fprintf(stderr,
"usage: rsh [-nd%s]%s[-l login] [login@]host [command]\n",
#ifdef KERBEROS
#ifdef CRYPT
"x", " [-k realm] ");
#else
"", " [-k realm] ");
#endif
#else
"", " ");
#endif
exit(1);
}