[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	5.1 (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/wait.h>

#include <netinet/in.h>

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

int	errno;
char	*index(), *rindex();
/* VARARGS 1 */
int	error();

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

	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, &on, sizeof (on)) < 0) {
		openlog(argv[0], LOG_PID, 0);
		syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
	}
	linger.l_onoff = 1;
	linger.l_linger = 60;			/* XXX */
	if (setsockopt(0, SOL_SOCKET, SO_LINGER, &linger, sizeof (linger)) < 0) {
		openlog(argv[0], LOG_PID, 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, backoff;
	struct hostent *hp;
	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) {
		openlog("rshd", LOG_PID, 0);
		syslog(LOG_ERR, "malformed from address\n");
		exit(1);
	}
	(void) alarm(60);
	port = 0;
	for (;;) {
		char c;
		if (read(f, &c, 1) != 1) {
			openlog("rshd", LOG_PID, 0);
			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, retryshift;
		s = rresvport(&lport);
		if (s < 0) {
			openlog("rshd", LOG_PID, 0);
			syslog(LOG_ERR, "can't get stderr port: %m");
			exit(1);
		}
		if (port >= IPPORT_RESERVED) {
			openlog("rshd", LOG_PID, 0);
			syslog(LOG_ERR, "2nd port not reserved\n");
			exit(1);
		}
		fromp->sin_port = htons((u_short)port);
		if (connect(s, fromp, sizeof (*fromp), 0) < 0) {
			openlog("rshd", LOG_PID, 0);
			syslog(LOG_ERR, "connect: %m");
			exit(1);
		}
	}
	dup2(f, 0);
	dup2(f, 1);
	dup2(f, 2);
	hp = gethostbyaddr(&fromp->sin_addr, sizeof (struct in_addr),
		fromp->sin_family);
	if (hp == 0) {
		error("Host name for your address unknown\n");
		exit(1);
	}
	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) {
		chdir("/");
#ifdef notdef
		error("No remote directory.\n");
		exit(1);
#endif
	}
	if (ruserok(hp->h_name, 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[1], FIONBIO, (char *)&one);
			/* should set s nbio! */
			do {
				ready = readfrom;
				if (select(16, &ready, 0, 0, 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(pwd->pw_gid);
	initgroups(pwd->pw_name, pwd->pw_gid);
	(void) setuid(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);
protofail:
	error("rsh: protocol failure detected by remote\n");
	exit(1);
}

/* VARARGS 1 */
error(fmt)
	char *fmt;
{
	char buf[BUFSIZ];

	buf[0] = 1;
	(void) sprintf(buf+1, fmt);
	(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
8c5eec2f DF	14	static char sccsid[] = "@(#)rshd.c 5.1 (Berkeley) %G%";
8c5eec2f DF	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>
ce4fd43b	27	#include <sys/wait.h>
e7d6d17a SL	28
	29	#include <netinet/in.h>
	30
	31	#include <stdio.h>
1d68cba5 BJ	32	#include <errno.h>
1d68cba5 BJ	33	#include <pwd.h>
1d68cba5	34	#include <signal.h>
3f5b52bc	35	#include <netdb.h>
3f99c0f7	36	#include <syslog.h>
1d68cba5 BJ	37
1d68cba5 BJ	38	int errno;
3f99c0f7	39	char index(), rindex();
1d68cba5 BJ	40	/* VARARGS 1 */
1d68cba5 BJ	41	int error();
bb933cc2	42
1d68cba5 BJ	43	main(argc, argv)
	44	int argc;
	45	char **argv;
	46	{
bcb894cb SL	47	struct linger linger;
bcb894cb SL	48	int on = 1, fromlen;
1d68cba5	49	struct sockaddr_in from;
3f5b52bc	50
bb933cc2 MK	51	fromlen = sizeof (from);
	52	if (getpeername(0, &from, &fromlen) < 0) {
	53	fprintf(stderr, "%s: ", argv[0]);
	54	perror("getpeername");
	55	_exit(1);
3f5b52bc	56	}
bcb894cb	57	if (setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof (on)) < 0) {
3f99c0f7 RC	58	openlog(argv[0], LOG_PID, 0);
3f99c0f7 RC	59	syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
e7d6d17a	60	}
bcb894cb SL	61	linger.l_onoff = 1;
bcb894cb SL	62	linger.l_linger = 60; /* XXX */
bb933cc2	63	if (setsockopt(0, SOL_SOCKET, SO_LINGER, &linger, sizeof (linger)) < 0) {
3f99c0f7 RC	64	openlog(argv[0], LOG_PID, 0);
3f99c0f7 RC	65	syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m");
1d68cba5	66	}
bb933cc2	67	doit(dup(0), &from);
a8e3386b SL	68	}
a8e3386b SL	69
1d68cba5 BJ	70	char username[20] = "USER=";
	71	char homedir[64] = "HOME=";
	72	char shell[64] = "SHELL=";
	73	char *envinit[] =
	74	{homedir, shell, "PATH=:/usr/ucb:/bin:/usr/bin", username, 0};
	75	char **environ;
	76
	77	doit(f, fromp)
	78	int f;
	79	struct sockaddr_in *fromp;
	80	{
	81	char cmdbuf[NCARGS+1], *cp;
	82	char locuser[16], remuser[16];
	83	struct passwd *pwd;
d173f55d	84	int s, backoff;
3f5b52bc	85	struct hostent *hp;
1d68cba5 BJ	86	short port;
	87	int pv[2], pid, ready, readfrom, cc;
	88	char buf[BUFSIZ], sig;
	89	int one = 1;
	90
	91	(void) signal(SIGINT, SIG_DFL);
	92	(void) signal(SIGQUIT, SIG_DFL);
	93	(void) signal(SIGTERM, SIG_DFL);
27890867	94	#ifdef DEBUG
1d68cba5 BJ	95	{ int t = open("/dev/tty", 2);
	96	if (t >= 0) {
	97	ioctl(t, TIOCNOTTY, (char *)0);
	98	(void) close(t);
	99	}
	100	}
	101	#endif
1d68cba5	102	fromp->sin_port = ntohs((u_short)fromp->sin_port);
1d68cba5	103	if (fromp->sin_family != AF_INET \|\|
d173f55d	104	fromp->sin_port >= IPPORT_RESERVED) {
3f99c0f7 RC	105	openlog("rshd", LOG_PID, 0);
3f99c0f7 RC	106	syslog(LOG_ERR, "malformed from address\n");
1d68cba5	107	exit(1);
d173f55d	108	}
1d68cba5 BJ	109	(void) alarm(60);
	110	port = 0;
	111	for (;;) {
	112	char c;
d173f55d	113	if (read(f, &c, 1) != 1) {
3f99c0f7 RC	114	openlog("rshd", LOG_PID, 0);
3f99c0f7 RC	115	syslog(LOG_ERR, "read: %m");
fadc6b8f	116	shutdown(f, 1+1);
1d68cba5	117	exit(1);
d173f55d	118	}
1d68cba5 BJ	119	if (c == 0)
	120	break;
	121	port = port * 10 + c - '0';
	122	}
	123	(void) alarm(0);
	124	if (port != 0) {
d173f55d	125	int lport = IPPORT_RESERVED - 1, retryshift;
3b0e7dec	126	s = rresvport(&lport);
d173f55d	127	if (s < 0) {
3f99c0f7 RC	128	openlog("rshd", LOG_PID, 0);
3f99c0f7 RC	129	syslog(LOG_ERR, "can't get stderr port: %m");
d173f55d SL	130	exit(1);
	131	}
	132	if (port >= IPPORT_RESERVED) {
3f99c0f7 RC	133	openlog("rshd", LOG_PID, 0);
3f99c0f7 RC	134	syslog(LOG_ERR, "2nd port not reserved\n");
1d68cba5	135	exit(1);
d173f55d	136	}
e23c0837	137	fromp->sin_port = htons((u_short)port);
27890867	138	if (connect(s, fromp, sizeof (*fromp), 0) < 0) {
3f99c0f7 RC	139	openlog("rshd", LOG_PID, 0);
3f99c0f7 RC	140	syslog(LOG_ERR, "connect: %m");
1d68cba5	141	exit(1);
d173f55d	142	}
1d68cba5	143	}
d173f55d SL	144	dup2(f, 0);
	145	dup2(f, 1);
	146	dup2(f, 2);
3f5b52bc SL	147	hp = gethostbyaddr(&fromp->sin_addr, sizeof (struct in_addr),
	148	fromp->sin_family);
	149	if (hp == 0) {
1d68cba5 BJ	150	error("Host name for your address unknown\n");
	151	exit(1);
	152	}
	153	getstr(remuser, sizeof(remuser), "remuser");
	154	getstr(locuser, sizeof(locuser), "locuser");
	155	getstr(cmdbuf, sizeof(cmdbuf), "command");
	156	setpwent();
	157	pwd = getpwnam(locuser);
	158	if (pwd == NULL) {
	159	error("Login incorrect.\n");
	160	exit(1);
	161	}
	162	endpwent();
	163	if (chdir(pwd->pw_dir) < 0) {
bb933cc2 MK	164	chdir("/");
bb933cc2 MK	165	#ifdef notdef
1d68cba5 BJ	166	error("No remote directory.\n");
1d68cba5 BJ	167	exit(1);
bb933cc2	168	#endif
1d68cba5	169	}
fadc6b8f	170	if (ruserok(hp->h_name, pwd->pw_uid == 0, remuser, locuser) < 0) {
1d68cba5 BJ	171	error("Permission denied.\n");
	172	exit(1);
	173	}
	174	(void) write(2, "\0", 1);
	175	if (port) {
	176	if (pipe(pv) < 0) {
	177	error("Can't make pipe.\n");
	178	exit(1);
	179	}
	180	pid = fork();
	181	if (pid == -1) {
	182	error("Try again.\n");
	183	exit(1);
	184	}
	185	if (pid) {
	186	(void) close(0); (void) close(1); (void) close(2);
	187	(void) close(f); (void) close(pv[1]);
	188	readfrom = (1<<s) \| (1<<pv[0]);
	189	ioctl(pv[1], FIONBIO, (char *)&one);
	190	/* should set s nbio! */
	191	do {
	192	ready = readfrom;
e7d6d17a SL	193	if (select(16, &ready, 0, 0, 0) < 0)
e7d6d17a SL	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);
1d68cba5	220	(void) setgid(pwd->pw_gid);
80aca4ff	221	initgroups(pwd->pw_name, pwd->pw_gid);
fadc6b8f	222	(void) setuid(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);
	235	protofail:
	236	error("rsh: protocol failure detected by remote\n");
	237	exit(1);
	238	}
	239
	240	/* VARARGS 1 */
	241	error(fmt)
	242	char *fmt;
	243	{
	244	char buf[BUFSIZ];
	245
	246	buf[0] = 1;
	247	(void) sprintf(buf+1, fmt);
	248	(void) write(2, buf, strlen(buf));
	249	}
	250
	251	getstr(buf, cnt, err)
	252	char *buf;
	253	int cnt;
	254	char *err;
	255	{
	256	char c;
	257
	258	do {
	259	if (read(0, &c, 1) != 1)
	260	exit(1);
	261	*buf++ = c;
	262	if (--cnt == 0) {
	263	error("%s too long\n", err);
	264	exit(1);
	265	}
	266	} while (c != 0);
	267	}