[unix-history] / usr / src / libexec / rshd / rshd.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1983 Regents of the University of California.\n\
 All rights reserved.\n";
#endif not lint

#ifndef lint
static char sccsid[] = "@(#)rshd.c	5.8 (Berkeley) %G%";
#endif not lint

/*
 * remote shell server:
 *	remuser\0
 *	locuser\0
 *	command\0
 *	data
 */
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <stdio.h>
#include <errno.h>
#include <pwd.h>
#include <signal.h>
#include <netdb.h>
#include <syslog.h>

int	errno;
char	*index(), *rindex(), *strncat();
/*VARARGS1*/
int	error();

/*ARGSUSED*/
main(argc, argv)
	int argc;
	char **argv;
{
	struct linger linger;
	int on = 1, fromlen;
	struct sockaddr_in from;

	openlog("rsh", LOG_PID | LOG_ODELAY, LOG_DAEMON);
	fromlen = sizeof (from);
	if (getpeername(0, &from, &fromlen) < 0) {
		fprintf(stderr, "%s: ", argv[0]);
		perror("getpeername");
		_exit(1);
	}
	if (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");
	doit(dup(0), &from);
}

char	username[20] = "USER=";
char	homedir[64] = "HOME=";
char	shell[64] = "SHELL=";
char	*envinit[] =
	    {homedir, shell, "PATH=:/usr/ucb:/bin:/usr/bin", username, 0};
char	**environ;

doit(f, fromp)
	int f;
	struct sockaddr_in *fromp;
{
	char cmdbuf[NCARGS+1], *cp;
	char locuser[16], remuser[16];
	struct passwd *pwd;
	int s;
	struct hostent *hp;
	char *hostname;
	short port;
	int pv[2], pid, ready, readfrom, cc;
	char buf[BUFSIZ], sig;
	int one = 1;

	(void) signal(SIGINT, SIG_DFL);
	(void) signal(SIGQUIT, SIG_DFL);
	(void) signal(SIGTERM, SIG_DFL);
#ifdef DEBUG
	{ int t = open("/dev/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 ||
	    fromp->sin_port >= IPPORT_RESERVED) {
		syslog(LOG_ERR, "malformed from address\n");
		exit(1);
	}
	(void) alarm(60);
	port = 0;
	for (;;) {
		char c;
		if (read(f, &c, 1) != 1) {
			syslog(LOG_ERR, "read: %m");
			shutdown(f, 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);
		}
		if (port >= IPPORT_RESERVED) {
			syslog(LOG_ERR, "2nd port not reserved\n");
			exit(1);
		}
		fromp->sin_port = htons((u_short)port);
		if (connect(s, fromp, sizeof (*fromp)) < 0) {
			syslog(LOG_INFO, "connect second port: %m");
			exit(1);
		}
	}
	dup2(f, 0);
	dup2(f, 1);
	dup2(f, 2);
	hp = gethostbyaddr((char *)&fromp->sin_addr, sizeof (struct in_addr),
		fromp->sin_family);
	if (hp)
		hostname = hp->h_name;
	else
		hostname = inet_ntoa(fromp->sin_addr);
	getstr(remuser, sizeof(remuser), "remuser");
	getstr(locuser, sizeof(locuser), "locuser");
	getstr(cmdbuf, sizeof(cmdbuf), "command");
	setpwent();
	pwd = getpwnam(locuser);
	if (pwd == NULL) {
		error("Login incorrect.\n");
		exit(1);
	}
	endpwent();
	if (chdir(pwd->pw_dir) < 0) {
		(void) chdir("/");
#ifdef notdef
		error("No remote directory.\n");
		exit(1);
#endif
	}
	if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' &&
	    ruserok(hostname, pwd->pw_uid == 0, remuser, locuser) < 0) {
		error("Permission denied.\n");
		exit(1);
	}
	(void) write(2, "\0", 1);
	if (port) {
		if (pipe(pv) < 0) {
			error("Can't make pipe.\n");
			exit(1);
		}
		pid = fork();
		if (pid == -1)  {
			error("Try again.\n");
			exit(1);
		}
		if (pid) {
			(void) close(0); (void) close(1); (void) close(2);
			(void) close(f); (void) close(pv[1]);
			readfrom = (1<<s) | (1<<pv[0]);
			ioctl(pv[0], FIONBIO, (char *)&one);
			/* should set s nbio! */
			do {
				ready = readfrom;
				if (select(16, &ready, (fd_set *)0,
				    (fd_set *)0, (struct timeval *)0) < 0)
					break;
				if (ready & (1<<s)) {
					if (read(s, &sig, 1) <= 0)
						readfrom &= ~(1<<s);
					else
						killpg(pid, sig);
				}
				if (ready & (1<<pv[0])) {
					errno = 0;
					cc = read(pv[0], buf, sizeof (buf));
					if (cc <= 0) {
						shutdown(s, 1+1);
						readfrom &= ~(1<<pv[0]);
					} else
						(void) write(s, buf, cc);
				}
			} while (readfrom);
			exit(0);
		}
		setpgrp(0, getpid());
		(void) close(s); (void) close(pv[0]);
		dup2(pv[1], 2);
	}
	if (*pwd->pw_shell == '\0')
		pwd->pw_shell = "/bin/sh";
	(void) close(f);
	(void) setgid((gid_t)pwd->pw_gid);
	initgroups(pwd->pw_name, pwd->pw_gid);
	(void) setuid((uid_t)pwd->pw_uid);
	environ = envinit;
	strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
	strncat(shell, pwd->pw_shell, sizeof(shell)-7);
	strncat(username, pwd->pw_name, sizeof(username)-6);
	cp = rindex(pwd->pw_shell, '/');
	if (cp)
		cp++;
	else
		cp = pwd->pw_shell;
	execl(pwd->pw_shell, cp, "-c", cmdbuf, 0);
	perror(pwd->pw_shell);
	exit(1);
}

/*VARARGS1*/
error(fmt, a1, a2, a3)
	char *fmt;
	int a1, a2, a3;
{
	char buf[BUFSIZ];

	buf[0] = 1;
	(void) sprintf(buf+1, fmt, a1, a2, a3);
	(void) write(2, buf, strlen(buf));
}

getstr(buf, cnt, err)
	char *buf;
	int cnt;
	char *err;
{
	char c;

	do {
		if (read(0, &c, 1) != 1)
			exit(1);
		*buf++ = c;
		if (--cnt == 0) {
			error("%s too long\n", err);
			exit(1);
		}
	} while (c != 0);
}
Commit	Line	Data
8c5eec2f DF	1	/*
	2	* Copyright (c) 1983 Regents of the University of California.
	3	* All rights reserved. The Berkeley software License Agreement
	4	* specifies the terms and conditions for redistribution.
	5	*/
	6
	7	#ifndef lint
	8	char copyright[] =
	9	"@(#) Copyright (c) 1983 Regents of the University of California.\n\
	10	All rights reserved.\n";
	11	#endif not lint
	12
1d68cba5	13	#ifndef lint
71419d2d	14	static char sccsid[] = "@(#)rshd.c 5.8 (Berkeley) %G%";
8c5eec2f	15	#endif not lint
1d68cba5	16
bb933cc2 MK	17	/*
	18	* remote shell server:
	19	* remuser\0
	20	* locuser\0
	21	* command\0
	22	* data
	23	*/
1d68cba5 BJ	24	#include <sys/ioctl.h>
	25	#include <sys/param.h>
	26	#include <sys/socket.h>
d4413a13	27	#include <sys/time.h>
e7d6d17a SL	28
	29	#include <netinet/in.h>
	30
4c99408e JB	31	#include <arpa/inet.h>
4c99408e JB	32
e7d6d17a	33	#include <stdio.h>
1d68cba5 BJ	34	#include <errno.h>
1d68cba5 BJ	35	#include <pwd.h>
1d68cba5	36	#include <signal.h>
3f5b52bc	37	#include <netdb.h>
3f99c0f7	38	#include <syslog.h>
1d68cba5 BJ	39
1d68cba5 BJ	40	int errno;
d4413a13 JL	41	char index(), rindex(), *strncat();
d4413a13 JL	42	/VARARGS1/
1d68cba5	43	int error();
bb933cc2	44
d4413a13	45	/ARGSUSED/
1d68cba5 BJ	46	main(argc, argv)
	47	int argc;
	48	char **argv;
	49	{
bcb894cb SL	50	struct linger linger;
bcb894cb SL	51	int on = 1, fromlen;
1d68cba5	52	struct sockaddr_in from;
3f5b52bc	53
076ae92c	54	openlog("rsh", LOG_PID \| LOG_ODELAY, LOG_DAEMON);
bb933cc2 MK	55	fromlen = sizeof (from);
	56	if (getpeername(0, &from, &fromlen) < 0) {
	57	fprintf(stderr, "%s: ", argv[0]);
	58	perror("getpeername");
	59	_exit(1);
3f5b52bc	60	}
d4413a13 JL	61	if (setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on,
d4413a13 JL	62	sizeof (on)) < 0)
3f99c0f7	63	syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
bcb894cb SL	64	linger.l_onoff = 1;
bcb894cb SL	65	linger.l_linger = 60; /* XXX */
d4413a13 JL	66	if (setsockopt(0, SOL_SOCKET, SO_LINGER, (char *)&linger,
d4413a13 JL	67	sizeof (linger)) < 0)
3f99c0f7	68	syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m");
bb933cc2	69	doit(dup(0), &from);
a8e3386b SL	70	}
a8e3386b SL	71
1d68cba5 BJ	72	char username[20] = "USER=";
	73	char homedir[64] = "HOME=";
	74	char shell[64] = "SHELL=";
	75	char *envinit[] =
	76	{homedir, shell, "PATH=:/usr/ucb:/bin:/usr/bin", username, 0};
	77	char **environ;
	78
	79	doit(f, fromp)
	80	int f;
	81	struct sockaddr_in *fromp;
	82	{
	83	char cmdbuf[NCARGS+1], *cp;
	84	char locuser[16], remuser[16];
	85	struct passwd *pwd;
d4413a13	86	int s;
3f5b52bc	87	struct hostent *hp;
7ad57ed0	88	char *hostname;
1d68cba5 BJ	89	short port;
	90	int pv[2], pid, ready, readfrom, cc;
	91	char buf[BUFSIZ], sig;
	92	int one = 1;
	93
	94	(void) signal(SIGINT, SIG_DFL);
	95	(void) signal(SIGQUIT, SIG_DFL);
	96	(void) signal(SIGTERM, SIG_DFL);
27890867	97	#ifdef DEBUG
1d68cba5 BJ	98	{ int t = open("/dev/tty", 2);
	99	if (t >= 0) {
	100	ioctl(t, TIOCNOTTY, (char *)0);
	101	(void) close(t);
	102	}
	103	}
	104	#endif
1d68cba5	105	fromp->sin_port = ntohs((u_short)fromp->sin_port);
1d68cba5	106	if (fromp->sin_family != AF_INET \|\|
d173f55d	107	fromp->sin_port >= IPPORT_RESERVED) {
3f99c0f7	108	syslog(LOG_ERR, "malformed from address\n");
1d68cba5	109	exit(1);
d173f55d	110	}
1d68cba5 BJ	111	(void) alarm(60);
	112	port = 0;
	113	for (;;) {
	114	char c;
d173f55d	115	if (read(f, &c, 1) != 1) {
3f99c0f7	116	syslog(LOG_ERR, "read: %m");
fadc6b8f	117	shutdown(f, 1+1);
1d68cba5	118	exit(1);
d173f55d	119	}
1d68cba5 BJ	120	if (c == 0)
	121	break;
	122	port = port * 10 + c - '0';
	123	}
	124	(void) alarm(0);
	125	if (port != 0) {
d4413a13	126	int lport = IPPORT_RESERVED - 1;
3b0e7dec	127	s = rresvport(&lport);
d173f55d	128	if (s < 0) {
3f99c0f7	129	syslog(LOG_ERR, "can't get stderr port: %m");
d173f55d SL	130	exit(1);
	131	}
	132	if (port >= IPPORT_RESERVED) {
3f99c0f7	133	syslog(LOG_ERR, "2nd port not reserved\n");
1d68cba5	134	exit(1);
d173f55d	135	}
e23c0837	136	fromp->sin_port = htons((u_short)port);
d4413a13	137	if (connect(s, fromp, sizeof (*fromp)) < 0) {
7ad57ed0	138	syslog(LOG_INFO, "connect second port: %m");
1d68cba5	139	exit(1);
d173f55d	140	}
1d68cba5	141	}
d173f55d SL	142	dup2(f, 0);
	143	dup2(f, 1);
	144	dup2(f, 2);
d4413a13	145	hp = gethostbyaddr((char *)&fromp->sin_addr, sizeof (struct in_addr),
3f5b52bc	146	fromp->sin_family);
7ad57ed0 MK	147	if (hp)
	148	hostname = hp->h_name;
	149	else
	150	hostname = inet_ntoa(fromp->sin_addr);
1d68cba5 BJ	151	getstr(remuser, sizeof(remuser), "remuser");
	152	getstr(locuser, sizeof(locuser), "locuser");
	153	getstr(cmdbuf, sizeof(cmdbuf), "command");
	154	setpwent();
	155	pwd = getpwnam(locuser);
	156	if (pwd == NULL) {
	157	error("Login incorrect.\n");
	158	exit(1);
	159	}
	160	endpwent();
	161	if (chdir(pwd->pw_dir) < 0) {
d4413a13	162	(void) chdir("/");
bb933cc2	163	#ifdef notdef
1d68cba5 BJ	164	error("No remote directory.\n");
1d68cba5 BJ	165	exit(1);
bb933cc2	166	#endif
1d68cba5	167	}
792e68a4	168	if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' &&
7ad57ed0	169	ruserok(hostname, pwd->pw_uid == 0, remuser, locuser) < 0) {
1d68cba5 BJ	170	error("Permission denied.\n");
	171	exit(1);
	172	}
	173	(void) write(2, "\0", 1);
	174	if (port) {
	175	if (pipe(pv) < 0) {
	176	error("Can't make pipe.\n");
	177	exit(1);
	178	}
	179	pid = fork();
	180	if (pid == -1) {
	181	error("Try again.\n");
	182	exit(1);
	183	}
	184	if (pid) {
	185	(void) close(0); (void) close(1); (void) close(2);
	186	(void) close(f); (void) close(pv[1]);
	187	readfrom = (1<<s) \| (1<<pv[0]);
71419d2d	188	ioctl(pv[0], FIONBIO, (char *)&one);
1d68cba5 BJ	189	/* should set s nbio! */
	190	do {
	191	ready = readfrom;
d4413a13 JL	192	if (select(16, &ready, (fd_set *)0,
d4413a13 JL	193	(fd_set )0, (struct timeval )0) < 0)
e7d6d17a	194	break;
1d68cba5 BJ	195	if (ready & (1<<s)) {
	196	if (read(s, &sig, 1) <= 0)
	197	readfrom &= ~(1<<s);
	198	else
	199	killpg(pid, sig);
	200	}
	201	if (ready & (1<<pv[0])) {
fadc6b8f	202	errno = 0;
1d68cba5 BJ	203	cc = read(pv[0], buf, sizeof (buf));
1d68cba5 BJ	204	if (cc <= 0) {
ff24c640	205	shutdown(s, 1+1);
1d68cba5 BJ	206	readfrom &= ~(1<<pv[0]);
	207	} else
	208	(void) write(s, buf, cc);
	209	}
	210	} while (readfrom);
	211	exit(0);
	212	}
	213	setpgrp(0, getpid());
	214	(void) close(s); (void) close(pv[0]);
	215	dup2(pv[1], 2);
	216	}
	217	if (*pwd->pw_shell == '\0')
	218	pwd->pw_shell = "/bin/sh";
	219	(void) close(f);
d4413a13	220	(void) setgid((gid_t)pwd->pw_gid);
80aca4ff	221	initgroups(pwd->pw_name, pwd->pw_gid);
d4413a13	222	(void) setuid((uid_t)pwd->pw_uid);
1d68cba5 BJ	223	environ = envinit;
	224	strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
	225	strncat(shell, pwd->pw_shell, sizeof(shell)-7);
	226	strncat(username, pwd->pw_name, sizeof(username)-6);
	227	cp = rindex(pwd->pw_shell, '/');
	228	if (cp)
	229	cp++;
	230	else
	231	cp = pwd->pw_shell;
	232	execl(pwd->pw_shell, cp, "-c", cmdbuf, 0);
	233	perror(pwd->pw_shell);
	234	exit(1);
1d68cba5 BJ	235	}
1d68cba5 BJ	236
d4413a13	237	/VARARGS1/
35db6ea0	238	error(fmt, a1, a2, a3)
1d68cba5	239	char *fmt;
35db6ea0	240	int a1, a2, a3;
1d68cba5 BJ	241	{
	242	char buf[BUFSIZ];
	243
	244	buf[0] = 1;
35db6ea0	245	(void) sprintf(buf+1, fmt, a1, a2, a3);
1d68cba5 BJ	246	(void) write(2, buf, strlen(buf));
	247	}
	248
	249	getstr(buf, cnt, err)
	250	char *buf;
	251	int cnt;
	252	char *err;
	253	{
	254	char c;
	255
	256	do {
	257	if (read(0, &c, 1) != 1)
	258	exit(1);
	259	*buf++ = c;
	260	if (--cnt == 0) {
	261	error("%s too long\n", err);
	262	exit(1);
	263	}
	264	} while (c != 0);
	265	}