NetBSD-5.0.2/usr.bin/rsh/rsh.c
/* $NetBSD: rsh.c,v 1.30 2008/07/21 14:19:25 lukem 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. 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) 1983, 1990, 1993, 1994\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)rsh.c 8.4 (Berkeley) 4/29/95";
#else
__RCSID("$NetBSD: rsh.c,v 1.30 2008/07/21 14:19:25 lukem Exp $");
#endif
#endif /* not lint */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <poll.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netdb.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <pwd.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "pathnames.h"
#include "getport.h"
/*
* rsh - remote shell
*/
int remerr;
static int sigs[] = { SIGINT, SIGTERM, SIGQUIT };
char *copyargs(char **);
void sendsig(int);
int checkfd(struct pollfd *, int);
void talk(int, sigset_t *, pid_t, int);
void usage(void);
int main(int, char **);
#ifdef IN_RCMD
int orcmd(char **, int, const char *,
const char *, const char *, int *);
int orcmd_af(char **, int, const char *,
const char *, const char *, int *, int);
#endif
int
main(int argc, char **argv)
{
struct passwd *pw;
struct servent *sp;
sigset_t oset, nset;
struct protoent *proto;
#ifdef IN_RCMD
char *locuser = 0, *loop;
#endif /* IN_RCMD */
int argoff, asrsh, ch, dflag, nflag, one, rem, i;
int family = AF_UNSPEC;
pid_t pid;
uid_t uid;
char *args, *host, *p, *user, *name;
argoff = asrsh = dflag = nflag = 0;
one = 1;
host = user = NULL;
sp = NULL;
#ifndef IN_RCMD
/*
* If called as something other than "rsh" use it as the host name,
* only for rsh.
*/
if (strcmp(getprogname(), "rsh") == 0)
asrsh = 1;
else {
host = strdup(getprogname());
if (host == NULL)
err(1, NULL);
}
#endif /* IN_RCMD */
/* handle "rsh host flags" */
if (!host && argc > 2 && argv[1][0] != '-') {
host = argv[1];
argoff = 1;
}
#ifdef IN_RCMD
if ((loop = getenv("RCMD_LOOP")) && strcmp(loop, "YES") == 0)
warnx("rcmd appears to be looping!");
putenv("RCMD_LOOP=YES");
# define OPTIONS "468KLdel:np:u:w"
#else /* IN_RCMD */
# define OPTIONS "468KLdel:np:w"
#endif /* IN_RCMD */
if (!(pw = getpwuid(uid = getuid())))
errx(1, "unknown user id");
if ((name = strdup(pw->pw_name)) == NULL)
err(1, "malloc");
while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != -1)
switch(ch) {
case '4':
family = AF_INET;
break;
case '6':
family = AF_INET6;
break;
case 'K':
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;
case 'n':
nflag = 1;
break;
case 'p':
sp = getport(optarg, "tcp");
break;
#ifdef IN_RCMD
case 'u':
if (getuid() != 0 && optarg && name &&
strcmp(name, optarg) != 0)
errx(1,"only super user can use the -u option");
locuser = optarg;
break;
#endif /* IN_RCMD */
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]) {
#ifdef IN_RCMD
usage();
#else
if (asrsh)
*argv = __UNCONST("rlogin");
execv(_PATH_RLOGIN, argv);
err(1, "can't exec %s", _PATH_RLOGIN);
#endif
}
argc -= optind;
argv += optind;
/* 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 = name;
args = copyargs(argv);
if (sp == NULL)
sp = getservbyname("shell", "tcp");
if (sp == NULL)
errx(1, "shell/tcp: unknown service");
#ifdef IN_RCMD
rem = orcmd_af(&host, sp->s_port, locuser ? locuser :
#else
rem = rcmd_af(&host, sp->s_port,
#endif
name, user, args, &remerr, family);
(void)free(name);
if (rem < 0)
exit(1);
if (remerr < 0)
errx(1, "can't establish stderr");
if (dflag) {
if (setsockopt(rem, SOL_SOCKET, SO_DEBUG, &one,
sizeof(one)) < 0)
warn("setsockopt remote");
if (setsockopt(remerr, SOL_SOCKET, SO_DEBUG, &one,
sizeof(one)) < 0)
warn("setsockopt stderr");
}
proto = getprotobyname("tcp");
setsockopt(rem, proto->p_proto, TCP_NODELAY, &one, sizeof(one));
setsockopt(remerr, proto->p_proto, TCP_NODELAY, &one, sizeof(one));
(void)setuid(uid);
(void)sigemptyset(&nset);
for (i = 0; i < sizeof(sigs) / sizeof(sigs[0]); i++)
(void)sigaddset(&nset, sigs[i]);
(void)sigprocmask(SIG_BLOCK, &nset, &oset);
for (i = 0; i < sizeof(sigs) / sizeof(sigs[0]); i++) {
struct sigaction sa;
if (sa.sa_handler != SIG_IGN) {
sa.sa_handler = sendsig;
(void)sigaction(sigs[i], &sa, NULL);
}
}
if (!nflag) {
pid = fork();
if (pid < 0)
err(1, "fork");
}
else
pid = -1;
#if defined(KERBEROS) && defined(CRYPT)
if (!doencrypt)
#endif
{
(void)ioctl(remerr, FIONBIO, &one);
(void)ioctl(rem, FIONBIO, &one);
}
talk(nflag, &oset, pid, rem);
if (!nflag)
(void)kill(pid, SIGKILL);
exit(0);
}
int
checkfd(struct pollfd *fdp, int outfd)
{
int nr, nw;
char buf[BUFSIZ];
if (fdp->revents & (POLLNVAL|POLLERR|POLLHUP))
return -1;
if ((fdp->revents & POLLIN) == 0)
return 0;
errno = 0;
#if defined(KERBEROS) && defined(CRYPT)
if (doencrypt)
nr = des_read(fdp->fd, buf, sizeof buf);
else
#endif
nr = read(fdp->fd, buf, sizeof buf);
if (nr <= 0) {
if (errno != EAGAIN)
return -1;
else
return 0;
}
else {
char *bc = buf;
while (nr) {
if ((nw = write(outfd, bc, nr)) <= 0)
return -1;
nr -= nw;
bc += nw;
}
return 0;
}
}
void
talk(int nflag, sigset_t *oset, __pid_t pid, int rem)
{
int nr, nw, nfds;
struct pollfd fds[2], *fdp = &fds[0];
char *bp, buf[BUFSIZ];
if (!nflag && pid == 0) {
(void)close(remerr);
fdp->events = POLLOUT|POLLNVAL|POLLERR|POLLHUP;
fdp->fd = rem;
nr = 0;
bp = buf;
for (;;) {
errno = 0;
if (nr == 0) {
if ((nr = read(0, buf, sizeof buf)) == 0)
goto done;
if (nr == -1) {
if (errno == EIO)
goto done;
if (errno == EINTR) {
nr = 0;
continue;
}
err(1, "read");
}
bp = buf;
}
rewrite: if (poll(fdp, 1, INFTIM) == -1) {
if (errno != EINTR)
err(1, "poll");
goto rewrite;
}
if (fdp->revents & (POLLNVAL|POLLERR|POLLHUP))
err(1, "poll");
if ((fdp->revents & POLLOUT) == 0)
goto rewrite;
#if defined(KERBEROS) && defined(CRYPT)
if (doencrypt)
nw = des_write(rem, bp, nr);
else
#endif
nw = write(rem, bp, nr);
if (nw < 0) {
if (errno == EAGAIN)
continue;
err(1, "write");
}
bp += nw;
nr -= nw;
}
done:
(void)shutdown(rem, 1);
exit(0);
}
(void)sigprocmask(SIG_SETMASK, oset, NULL);
fds[0].events = fds[1].events = POLLIN|POLLNVAL|POLLERR|POLLHUP;
fds[0].fd = remerr;
fds[1].fd = rem;
fdp = &fds[0];
nfds = 2;
do {
if (poll(fdp, nfds, INFTIM) == -1) {
if (errno != EINTR)
err(1, "poll");
continue;
}
if (fds[0].events != 0 && checkfd(&fds[0], 2) == -1) {
nfds--;
fds[0].events = 0;
fdp = &fds[1];
}
if (fds[1].events != 0 && checkfd(&fds[1], 1) == -1) {
nfds--;
fds[1].events = 0;
}
}
while (nfds);
}
void
sendsig(int sig)
{
char signo;
signo = sig;
(void)write(remerr, &signo, 1);
}
char *
copyargs(char **argv)
{
int cc;
char **ap, *args, *p, *ep;
cc = 0;
for (ap = argv; *ap; ++ap)
cc += strlen(*ap) + 1;
if (!(args = malloc((u_int)cc)))
err(1, "malloc");
ep = args + cc;
for (p = args, *p = '\0', ap = argv; *ap; ++ap) {
(void)strlcpy(p, *ap, ep - p);
p += strlen(p);
if (ap[1])
*p++ = ' ';
}
*p = '\0';
return (args);
}
void
usage(void)
{
(void)fprintf(stderr,
"usage: %s [-46dn] [-l login] [-p port]%s [login@]host command\n",
getprogname(),
#ifdef IN_RCMD
" [-u locuser]"
#else
""
#endif
);
exit(1);
}