usr/src/usr.bin/rlogin/rlogin.c

#ifndef lint
static char sccsid[] = "@(#)rlogin.c	4.15 (Berkeley) 83/07/02";
#endif

/*
 * rlogin - remote login
 */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>

#include <netinet/in.h>

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

char	*index(), *rindex(), *malloc(), *getenv();
struct	passwd *getpwuid();
char	*name;
int	rem;
char	cmdchar = '~';
int	eight;
char	*speeds[] =
    { "0", "50", "75", "110", "134", "150", "200", "300",
      "600", "1200", "1800", "2400", "4800", "9600", "19200", "38400" };
char	term[64] = "network";
extern	int errno;
int	lostpeer();

main(argc, argv)
	int argc;
	char **argv;
{
	char *host, *cp;
	struct sgttyb ttyb;
	struct passwd *pwd;
	struct servent *sp;
	int uid, options = 0;

	host = rindex(argv[0], '/');
	if (host)
		host++;
	else
		host = argv[0];
	argv++, --argc;
	if (!strcmp(host, "rlogin"))
		host = *argv++, --argc;
another:
	if (argc > 0 && !strcmp(*argv, "-d")) {
		argv++, argc--;
		options |= SO_DEBUG;
		goto another;
	}
	if (argc > 0 && !strcmp(*argv, "-l")) {
		argv++, argc--;
		if (argc == 0)
			goto usage;
		name = *argv++; argc--;
		goto another;
	}
	if (argc > 0 && !strncmp(*argv, "-e", 2)) {
		cmdchar = argv[0][2];
		argv++, argc--;
		goto another;
	}
	if (argc > 0 && !strcmp(*argv, "-8")) {
		eight = 1;
		argv++, argc--;
		goto another;
	}
	if (host == 0)
		goto usage;
	if (argc > 0)
		goto usage;
	pwd = getpwuid(getuid());
	if (pwd == 0) {
		fprintf(stderr, "Who are you?\n");
		exit(1);
	}
	sp = getservbyname("login", "tcp");
	if (sp == 0) {
		fprintf(stderr, "rlogin: login/tcp: unknown service\n");
		exit(2);
	}
	cp = getenv("TERM");
	if (cp)
		strcpy(term, cp);
	if (ioctl(0, TIOCGETP, &ttyb)==0) {
		strcat(term, "/");
		strcat(term, speeds[ttyb.sg_ospeed]);
	}
	signal(SIGPIPE, lostpeer);
        rem = rcmd(&host, sp->s_port, pwd->pw_name,
	    name ? name : pwd->pw_name, term, 0);
        if (rem < 0)
                exit(1);
	if (options & SO_DEBUG &&
	    setsockopt(rem, SOL_SOCKET, SO_DEBUG, 0, 0) < 0)
		perror("rlogin: setsockopt (SO_DEBUG)");
	uid = getuid();
	if (setuid(uid) < 0) {
		perror("rlogin: setuid");
		exit(1);
	}
	doit();
	/*NOTREACHED*/
usage:
	fprintf(stderr,
	    "usage: rlogin host [ -ex ] [ -l username ] [ -8 ]\n");
	exit(1);
}

#define CRLF "\r\n"

int	child;
int	catchild();

int	defflags, tabflag;
char	deferase, defkill;
struct	tchars deftc;
struct	ltchars defltc;
struct	tchars notc =	{ -1, -1, -1, -1, -1, -1 };
struct	ltchars noltc =	{ -1, -1, -1, -1, -1, -1 };

doit()
{
	int exit();
	struct sgttyb sb;

	ioctl(0, TIOCGETP, (char *)&sb);
	defflags = sb.sg_flags;
	tabflag = defflags & TBDELAY;
	defflags &= ECHO | CRMOD;
	deferase = sb.sg_erase;
	defkill = sb.sg_kill;
	ioctl(0, TIOCGETC, (char *)&deftc);
	notc.t_startc = deftc.t_startc;
	notc.t_stopc = deftc.t_stopc;
	ioctl(0, TIOCGLTC, (char *)&defltc);
	signal(SIGINT, exit);
	signal(SIGHUP, exit);
	signal(SIGQUIT, exit);
	child = fork();
	if (child == -1) {
		perror("rlogin: fork");
		done();
	}
	signal(SIGINT, SIG_IGN);
	mode(1);
	if (child == 0) {
		reader();
		sleep(1);
		prf("\007Connection closed.");
		exit(3);
	}
	signal(SIGCHLD, catchild);
	writer();
	prf("Closed connection.");
	done();
}

done()
{

	mode(0);
	if (child > 0 && kill(child, SIGKILL) >= 0)
		wait((int *)0);
	exit(0);
}

catchild()
{
	union wait status;
	int pid;

again:
	pid = wait3(&status, WNOHANG|WUNTRACED, 0);
	if (pid == 0)
		return;
	/*
	 * if the child (reader) dies, just quit
	 */
	if (pid < 0 || pid == child && !WIFSTOPPED(status))
		done();
	goto again;
}

/*
 * writer: write to remote: 0 -> line.
 * ~.	terminate
 * ~^Z	suspend rlogin process.
 * ~^Y  suspend rlogin process, but leave reader alone.
 */
writer()
{
	char b[600], c;
	register char *p;
	register n;

top:
	p = b;
	for (;;) {
		int local;

		n = read(0, &c, 1);
		if (n == 0)
			break;
		if (n < 0)
			if (errno == EINTR)
				continue;
			else
				break;

		if (eight == 0)
			c &= 0177;
		/*
		 * If we're at the beginning of the line
		 * and recognize a command character, then
		 * we echo locally.  Otherwise, characters
		 * are echo'd remotely.  If the command
		 * character is doubled, this acts as a
		 * force and local echo is suppressed.
		 */
		if (p == b)
			local = (c == cmdchar);
		if (p == b + 1 && *b == cmdchar)
			local = (c != cmdchar);
		if (!local) {
			if (write(rem, &c, 1) == 0) {
				prf("line gone");
				return;
			}
			if (eight == 0)
				c &= 0177;
		} else {
			if (c == '\r' || c == '\n') {
				char cmdc = b[1];

				if (cmdc == '.' || cmdc == deftc.t_eofc) {
					write(0, CRLF, sizeof(CRLF));
					return;
				}
				if (cmdc == defltc.t_suspc ||
				    cmdc == defltc.t_dsuspc) {
					write(0, CRLF, sizeof(CRLF));
					mode(0);
					signal(SIGCHLD, SIG_IGN);
					kill(cmdc == defltc.t_suspc ?
					  0 : getpid(), SIGTSTP);
					signal(SIGCHLD, catchild);
					mode(1);
					goto top;
				}
				*p++ = c;
				write(rem, b, p - b);
				goto top;
			}
			write(1, &c, 1);
		}
		*p++ = c;
		if (c == deferase) {
			p -= 2;
			if (p < b)
				goto top;
		}
		if (c == defkill || c == deftc.t_eofc ||
		    c == '\r' || c == '\n')
			goto top;
		if (p >= &b[sizeof b])
			p--;
	}
}

oob()
{
	int out = 1+1, atmark;
	char waste[BUFSIZ], mark;

	ioctl(1, TIOCFLUSH, (char *)&out);
	for (;;) {
		if (ioctl(rem, SIOCATMARK, &atmark) < 0) {
			perror("ioctl");
			break;
		}
		if (atmark)
			break;
		(void) read(rem, waste, sizeof (waste));
	}
	recv(rem, &mark, 1, MSG_OOB);
	if (mark & TIOCPKT_NOSTOP) {
		notc.t_stopc = -1;
		notc.t_startc = -1;
		ioctl(0, TIOCSETC, (char *)&notc);
	}
	if (mark & TIOCPKT_DOSTOP) {
		notc.t_stopc = deftc.t_stopc;
		notc.t_startc = deftc.t_startc;
		ioctl(0, TIOCSETC, (char *)&notc);
	}
}

/*
 * reader: read from remote: line -> 1
 */
reader()
{
	char rb[BUFSIZ];
	register int cnt;

	signal(SIGURG, oob);
	{ int pid = -getpid();
	  ioctl(rem, SIOCSPGRP, (char *)&pid); }
	for (;;) {
		cnt = read(rem, rb, sizeof (rb));
		if (cnt == 0)
			break;
		if (cnt < 0) {
			if (errno == EINTR)
				continue;
			break;
		}
		write(1, rb, cnt);
	}
}

mode(f)
{
	struct tchars *tc;
	struct ltchars *ltc;
	struct sgttyb sb;

	ioctl(0, TIOCGETP, (char *)&sb);
	switch (f) {

	case 0:
		sb.sg_flags &= ~(CBREAK|RAW|TBDELAY);
		sb.sg_flags |= defflags|tabflag;
		tc = &deftc;
		ltc = &defltc;
		sb.sg_kill = defkill;
		sb.sg_erase = deferase;
		break;

	case 1:
		sb.sg_flags |= (eight ? RAW : CBREAK);
		sb.sg_flags &= ~defflags;
		/* preserve tab delays, but turn off XTABS */
		if ((sb.sg_flags & TBDELAY) == XTABS)
			sb.sg_flags &= ~TBDELAY;
		tc = &notc;
		ltc = &noltc;
		sb.sg_kill = sb.sg_erase = -1;
		break;

	default:
		return;
	}
	ioctl(0, TIOCSLTC, (char *)ltc);
	ioctl(0, TIOCSETC, (char *)tc);
	ioctl(0, TIOCSETN, (char *)&sb);
}

/*VARARGS*/
prf(f, a1, a2, a3)
	char *f;
{
	fprintf(stderr, f, a1, a2, a3);
	fprintf(stderr, CRLF);
}

lostpeer()
{
	signal(SIGPIPE, SIG_IGN);
	prf("\007Connection closed.");
	done();
}
Commit	Line	Data
	1	#ifndef lint
	2	static char sccsid[] = "@(#)rlogin.c 4.15 (Berkeley) 83/07/02";
	3	#endif
	4
	5	/*
	6	* rlogin - remote login
	7	*/
	8	#include <sys/types.h>
	9	#include <sys/socket.h>
	10	#include <sys/wait.h>
	11
	12	#include <netinet/in.h>
	13
	14	#include <stdio.h>
	15	#include <sgtty.h>
	16	#include <errno.h>
	17	#include <pwd.h>
	18	#include <signal.h>
	19	#include <netdb.h>
	20
	21	char index(), rindex(), malloc(), getenv();
	22	struct passwd *getpwuid();
	23	char *name;
	24	int rem;
	25	char cmdchar = '~';
	26	int eight;
	27	char *speeds[] =
	28	{ "0", "50", "75", "110", "134", "150", "200", "300",
	29	"600", "1200", "1800", "2400", "4800", "9600", "19200", "38400" };
	30	char term[64] = "network";
	31	extern int errno;
	32	int lostpeer();
	33
	34	main(argc, argv)
	35	int argc;
	36	char **argv;
	37	{
	38	char host, cp;
	39	struct sgttyb ttyb;
	40	struct passwd *pwd;
	41	struct servent *sp;
	42	int uid, options = 0;
	43
	44	host = rindex(argv[0], '/');
	45	if (host)
	46	host++;
	47	else
	48	host = argv[0];
	49	argv++, --argc;
	50	if (!strcmp(host, "rlogin"))
	51	host = *argv++, --argc;
	52	another:
	53	if (argc > 0 && !strcmp(*argv, "-d")) {
	54	argv++, argc--;
	55	options \|= SO_DEBUG;
	56	goto another;
	57	}
	58	if (argc > 0 && !strcmp(*argv, "-l")) {
	59	argv++, argc--;
	60	if (argc == 0)
	61	goto usage;
	62	name = *argv++; argc--;
	63	goto another;
	64	}
	65	if (argc > 0 && !strncmp(*argv, "-e", 2)) {
	66	cmdchar = argv[0][2];
	67	argv++, argc--;
	68	goto another;
	69	}
	70	if (argc > 0 && !strcmp(*argv, "-8")) {
	71	eight = 1;
	72	argv++, argc--;
	73	goto another;
	74	}
	75	if (host == 0)
	76	goto usage;
	77	if (argc > 0)
	78	goto usage;
	79	pwd = getpwuid(getuid());
	80	if (pwd == 0) {
	81	fprintf(stderr, "Who are you?\n");
	82	exit(1);
	83	}
	84	sp = getservbyname("login", "tcp");
	85	if (sp == 0) {
	86	fprintf(stderr, "rlogin: login/tcp: unknown service\n");
	87	exit(2);
	88	}
	89	cp = getenv("TERM");
	90	if (cp)
	91	strcpy(term, cp);
	92	if (ioctl(0, TIOCGETP, &ttyb)==0) {
	93	strcat(term, "/");
	94	strcat(term, speeds[ttyb.sg_ospeed]);
	95	}
	96	signal(SIGPIPE, lostpeer);
	97	rem = rcmd(&host, sp->s_port, pwd->pw_name,
	98	name ? name : pwd->pw_name, term, 0);
	99	if (rem < 0)
	100	exit(1);
	101	if (options & SO_DEBUG &&
	102	setsockopt(rem, SOL_SOCKET, SO_DEBUG, 0, 0) < 0)
	103	perror("rlogin: setsockopt (SO_DEBUG)");
	104	uid = getuid();
	105	if (setuid(uid) < 0) {
	106	perror("rlogin: setuid");
	107	exit(1);
	108	}
	109	doit();
	110	/NOTREACHED/
	111	usage:
	112	fprintf(stderr,
	113	"usage: rlogin host [ -ex ] [ -l username ] [ -8 ]\n");
	114	exit(1);
	115	}
	116
	117	#define CRLF "\r\n"
	118
	119	int child;
	120	int catchild();
	121
	122	int defflags, tabflag;
	123	char deferase, defkill;
	124	struct tchars deftc;
	125	struct ltchars defltc;
	126	struct tchars notc = { -1, -1, -1, -1, -1, -1 };
	127	struct ltchars noltc = { -1, -1, -1, -1, -1, -1 };
	128
	129	doit()
	130	{
	131	int exit();
	132	struct sgttyb sb;
	133
	134	ioctl(0, TIOCGETP, (char *)&sb);
	135	defflags = sb.sg_flags;
	136	tabflag = defflags & TBDELAY;
	137	defflags &= ECHO \| CRMOD;
	138	deferase = sb.sg_erase;
	139	defkill = sb.sg_kill;
	140	ioctl(0, TIOCGETC, (char *)&deftc);
	141	notc.t_startc = deftc.t_startc;
	142	notc.t_stopc = deftc.t_stopc;
	143	ioctl(0, TIOCGLTC, (char *)&defltc);
	144	signal(SIGINT, exit);
	145	signal(SIGHUP, exit);
	146	signal(SIGQUIT, exit);
	147	child = fork();
	148	if (child == -1) {
	149	perror("rlogin: fork");
	150	done();
	151	}
	152	signal(SIGINT, SIG_IGN);
	153	mode(1);
	154	if (child == 0) {
	155	reader();
	156	sleep(1);
	157	prf("\007Connection closed.");
	158	exit(3);
	159	}
	160	signal(SIGCHLD, catchild);
	161	writer();
	162	prf("Closed connection.");
	163	done();
	164	}
	165
	166	done()
	167	{
	168
	169	mode(0);
	170	if (child > 0 && kill(child, SIGKILL) >= 0)
	171	wait((int *)0);
	172	exit(0);
	173	}
	174
	175	catchild()
	176	{
	177	union wait status;
	178	int pid;
	179
	180	again:
	181	pid = wait3(&status, WNOHANG\|WUNTRACED, 0);
	182	if (pid == 0)
	183	return;
	184	/*
	185	* if the child (reader) dies, just quit
	186	*/
	187	if (pid < 0 \|\| pid == child && !WIFSTOPPED(status))
	188	done();
	189	goto again;
	190	}
	191
	192	/*
	193	* writer: write to remote: 0 -> line.
	194	* ~. terminate
	195	* ~^Z suspend rlogin process.
	196	* ~^Y suspend rlogin process, but leave reader alone.
	197	*/
	198	writer()
	199	{
	200	char b[600], c;
	201	register char *p;
	202	register n;
	203
	204	top:
	205	p = b;
	206	for (;;) {
	207	int local;
	208
	209	n = read(0, &c, 1);
	210	if (n == 0)
	211	break;
	212	if (n < 0)
	213	if (errno == EINTR)
	214	continue;
	215	else
	216	break;
	217
	218	if (eight == 0)
	219	c &= 0177;
	220	/*
	221	* If we're at the beginning of the line
	222	* and recognize a command character, then
	223	* we echo locally. Otherwise, characters
	224	* are echo'd remotely. If the command
	225	* character is doubled, this acts as a
	226	* force and local echo is suppressed.
	227	*/
	228	if (p == b)
	229	local = (c == cmdchar);
	230	if (p == b + 1 && *b == cmdchar)
	231	local = (c != cmdchar);
	232	if (!local) {
	233	if (write(rem, &c, 1) == 0) {
	234	prf("line gone");
	235	return;
	236	}
	237	if (eight == 0)
	238	c &= 0177;
	239	} else {
	240	if (c == '\r' \|\| c == '\n') {
	241	char cmdc = b[1];
	242
	243	if (cmdc == '.' \|\| cmdc == deftc.t_eofc) {
	244	write(0, CRLF, sizeof(CRLF));
	245	return;
	246	}
	247	if (cmdc == defltc.t_suspc \|\|
	248	cmdc == defltc.t_dsuspc) {
	249	write(0, CRLF, sizeof(CRLF));
	250	mode(0);
	251	signal(SIGCHLD, SIG_IGN);
	252	kill(cmdc == defltc.t_suspc ?
	253	0 : getpid(), SIGTSTP);
	254	signal(SIGCHLD, catchild);
	255	mode(1);
	256	goto top;
	257	}
	258	*p++ = c;
	259	write(rem, b, p - b);
	260	goto top;
	261	}
	262	write(1, &c, 1);
	263	}
	264	*p++ = c;
	265	if (c == deferase) {
	266	p -= 2;
	267	if (p < b)
	268	goto top;
	269	}
	270	if (c == defkill \|\| c == deftc.t_eofc \|\|
	271	c == '\r' \|\| c == '\n')
	272	goto top;
	273	if (p >= &b[sizeof b])
	274	p--;
	275	}
	276	}
	277
	278	oob()
	279	{
	280	int out = 1+1, atmark;
	281	char waste[BUFSIZ], mark;
	282
	283	ioctl(1, TIOCFLUSH, (char *)&out);
	284	for (;;) {
	285	if (ioctl(rem, SIOCATMARK, &atmark) < 0) {
	286	perror("ioctl");
	287	break;
	288	}
	289	if (atmark)
	290	break;
	291	(void) read(rem, waste, sizeof (waste));
	292	}
	293	recv(rem, &mark, 1, MSG_OOB);
	294	if (mark & TIOCPKT_NOSTOP) {
	295	notc.t_stopc = -1;
	296	notc.t_startc = -1;
	297	ioctl(0, TIOCSETC, (char *)&notc);
	298	}
	299	if (mark & TIOCPKT_DOSTOP) {
	300	notc.t_stopc = deftc.t_stopc;
	301	notc.t_startc = deftc.t_startc;
	302	ioctl(0, TIOCSETC, (char *)&notc);
	303	}
	304	}
	305
	306	/*
	307	* reader: read from remote: line -> 1
	308	*/
	309	reader()
	310	{
	311	char rb[BUFSIZ];
	312	register int cnt;
	313
	314	signal(SIGURG, oob);
	315	{ int pid = -getpid();
	316	ioctl(rem, SIOCSPGRP, (char *)&pid); }
	317	for (;;) {
	318	cnt = read(rem, rb, sizeof (rb));
	319	if (cnt == 0)
	320	break;
	321	if (cnt < 0) {
	322	if (errno == EINTR)
	323	continue;
	324	break;
	325	}
	326	write(1, rb, cnt);
	327	}
	328	}
	329
	330	mode(f)
	331	{
	332	struct tchars *tc;
	333	struct ltchars *ltc;
	334	struct sgttyb sb;
	335
	336	ioctl(0, TIOCGETP, (char *)&sb);
	337	switch (f) {
	338
	339	case 0:
	340	sb.sg_flags &= ~(CBREAK\|RAW\|TBDELAY);
	341	sb.sg_flags \|= defflags\|tabflag;
	342	tc = &deftc;
	343	ltc = &defltc;
	344	sb.sg_kill = defkill;
	345	sb.sg_erase = deferase;
	346	break;
	347
	348	case 1:
	349	sb.sg_flags \|= (eight ? RAW : CBREAK);
	350	sb.sg_flags &= ~defflags;
	351	/* preserve tab delays, but turn off XTABS */
	352	if ((sb.sg_flags & TBDELAY) == XTABS)
	353	sb.sg_flags &= ~TBDELAY;
	354	tc = &notc;
	355	ltc = &noltc;
	356	sb.sg_kill = sb.sg_erase = -1;
	357	break;
	358
	359	default:
	360	return;
	361	}
	362	ioctl(0, TIOCSLTC, (char *)ltc);
	363	ioctl(0, TIOCSETC, (char *)tc);
	364	ioctl(0, TIOCSETN, (char *)&sb);
	365	}
	366
	367	/VARARGS/
	368	prf(f, a1, a2, a3)
	369	char *f;
	370	{
	371	fprintf(stderr, f, a1, a2, a3);
	372	fprintf(stderr, CRLF);
	373	}
	374
	375	lostpeer()
	376	{
	377	signal(SIGPIPE, SIG_IGN);
	378	prf("\007Connection closed.");
	379	done();
	380	}