4.3BSD-Reno/src/usr.bin/rsh/rsh.c
/*-
* Copyright (c) 1983, 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that: (1) source distributions retain this entire copyright
* notice and comment, and (2) distributions including binaries display
* the following acknowledgement: ``This product includes software
* developed by the University of California, Berkeley and its contributors''
* in the documentation or other materials provided with the distribution
* and in all advertising materials mentioning features or use of this
* software. 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1983, 1990 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)rsh.c 5.21 (Berkeley) 5/15/90";
#endif /* not lint */
/*
* $Source: mit/rsh/RCS/rsh.c,v $
* $Header: mit/rsh/RCS/rsh.c,v 5.1 89/07/31 19:28:59 kfall Exp Locker: kfall $
*/
#include <sys/types.h>
#include <sys/signal.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <netdb.h>
#include <pwd.h>
#include <stdio.h>
#include <errno.h>
#include <string.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, encrypt;
char dst_realm_buf[REALM_SZ], *dest_realm;
extern char *krb_realmofhost();
#endif
/*
* rsh - remote shell
*/
extern int errno;
int rfd2;
main(argc, argv)
int argc;
char **argv;
{
extern char *optarg;
extern int optind;
struct passwd *pw;
struct servent *sp;
long omask;
int argoff, asrsh, ch, dflag, nflag, one, pid, rem, uid;
register char *p;
char *args, *host, *user, *copyargs();
void sendsig();
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 = rindex(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
#define OPTIONS "8KLdek:l:nwx"
#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
case 'x':
encrypt = 1;
des_set_key(cred.session, schedule);
break;
#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);
(void)fprintf(stderr, "rsh: can't exec %s.\n", _PATH_RLOGIN);
exit(1);
}
argc -= optind;
argv += optind;
if (!(pw = getpwuid(uid = getuid()))) {
(void)fprintf(stderr, "rsh: unknown user id.\n");
exit(1);
}
if (!user)
user = pw->pw_name;
#ifdef KERBEROS
/* -x turns off -n */
if (encrypt)
nflag = 0;
#endif
args = copyargs(argv);
sp = NULL;
#ifdef KERBEROS
if (use_kerberos) {
sp = getservbyname((encrypt ? "ekshell" : "kshell"), "tcp");
if (sp == NULL) {
use_kerberos = 0;
warning("can't get entry for %s/tcp service",
encrypt ? "ekshell" : "kshell");
}
}
#endif
if (sp == NULL)
sp = getservbyname("shell", "tcp");
if (sp == NULL) {
(void)fprintf(stderr, "rsh: shell/tcp: unknown service.\n");
exit(1);
}
#ifdef KERBEROS
try_connect:
if (use_kerberos) {
rem = KSUCCESS;
errno = 0;
if (dest_realm == NULL)
dest_realm = krb_realmofhost(host);
if (encrypt)
rem = krcmd_mutual(&host, sp->s_port, user, args,
&rfd2, dest_realm, &cred, schedule);
else
rem = krcmd(&host, sp->s_port, user, args, &rfd2,
dest_realm);
if (rem < 0) {
use_kerberos = 0;
sp = getservbyname("shell", "tcp");
if (sp == NULL) {
(void)fprintf(stderr,
"rsh: unknown service shell/tcp.\n");
exit(1);
}
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 (encrypt) {
(void)fprintf(stderr,
"rsh: the -x flag requires Kerberos authentication.\n");
exit(1);
}
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) {
(void)fprintf(stderr, "rsh: can't establish stderr.\n");
exit(1);
}
if (dflag) {
if (setsockopt(rem, SOL_SOCKET, SO_DEBUG, &one,
sizeof(one)) < 0)
(void)fprintf(stderr, "rsh: setsockopt: %s.\n",
strerror(errno));
if (setsockopt(rfd2, SOL_SOCKET, SO_DEBUG, &one,
sizeof(one)) < 0)
(void)fprintf(stderr, "rsh: setsockopt: %s.\n",
strerror(errno));
}
(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) {
(void)fprintf(stderr,
"rsh: fork: %s.\n", strerror(errno));
exit(1);
}
}
#ifdef KERBEROS
if (!encrypt)
#endif
{
(void)ioctl(rfd2, FIONBIO, &one);
(void)ioctl(rem, FIONBIO, &one);
}
talk(nflag, omask, pid, rem);
if (!nflag)
(void)kill(pid, SIGKILL);
exit(0);
}
talk(nflag, omask, pid, rem)
int nflag, pid;
long omask;
register int rem;
{
register int cc, wc;
register char *bp;
int readfrom, ready, rembits;
char 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: rembits = 1 << rem;
if (select(16, 0, &rembits, 0, 0) < 0) {
if (errno != EINTR) {
(void)fprintf(stderr,
"rsh: select: %s.\n", strerror(errno));
exit(1);
}
goto rewrite;
}
if ((rembits & (1 << rem)) == 0)
goto rewrite;
#ifdef KERBEROS
if (encrypt)
wc = des_write(rem, bp, cc);
else
#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);
readfrom = (1 << rfd2) | (1 << rem);
do {
ready = readfrom;
if (select(16, &ready, 0, 0, 0) < 0) {
if (errno != EINTR) {
(void)fprintf(stderr,
"rsh: select: %s.\n", strerror(errno));
exit(1);
}
continue;
}
if (ready & (1 << rfd2)) {
errno = 0;
#ifdef KERBEROS
if (encrypt)
cc = des_read(rfd2, buf, sizeof buf);
else
#endif
cc = read(rfd2, buf, sizeof buf);
if (cc <= 0) {
if (errno != EWOULDBLOCK)
readfrom &= ~(1 << rfd2);
} else
(void)write(2, buf, cc);
}
if (ready & (1 << rem)) {
errno = 0;
#ifdef KERBEROS
if (encrypt)
cc = des_read(rem, buf, sizeof buf);
else
#endif
cc = read(rem, buf, sizeof buf);
if (cc <= 0) {
if (errno != EWOULDBLOCK)
readfrom &= ~(1 << rem);
} else
(void)write(1, buf, cc);
}
} while (readfrom);
}
void
sendsig(signo)
char signo;
{
#ifdef KERBEROS
if (encrypt)
(void)des_write(rfd2, &signo, 1);
else
#endif
(void)write(rfd2, &signo, 1);
}
#ifdef KERBEROS
/* VARARGS */
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;
{
register int cc;
register char **ap, *p;
char *args, *malloc();
cc = 0;
for (ap = argv; *ap; ++ap)
cc += strlen(*ap) + 1;
if (!(args = malloc((u_int)cc))) {
(void)fprintf(stderr, "rsh: %s.\n", strerror(ENOMEM));
exit(1);
}
for (p = args, ap = argv; *ap; ++ap) {
(void)strcpy(p, *ap);
for (p = strcpy(p, *ap); *p; ++p);
if (ap[1])
*p++ = ' ';
}
return(args);
}
usage()
{
(void)fprintf(stderr,
"usage: rsh [-ndx]%s[-l login] host [command]\n",
#ifdef KERBEROS
" [-k realm] ");
#else
" ");
#endif
exit(1);
}