[openssh.git] / pty.c

/*
 * 
 * pty.c
 * 
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * 
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * 
 * Created: Fri Mar 17 04:37:25 1995 ylo
 * 
 * Allocating a pseudo-terminal, and making it the controlling tty.
 * 
 */

#include "includes.h"
RCSID("$Id$");

#include "pty.h"
#include "ssh.h"

#ifdef HAVE_PTY_H
#include <pty.h>
#endif /* HAVE_PTY_H */

/* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */
#if defined(HAVE__GETPTY) || defined(HAVE_OPENPTY)
#undef HAVE_DEV_PTMX
#endif

#ifndef O_NOCTTY
#define O_NOCTTY 0
#endif

/*
 * Allocates and opens a pty.  Returns 0 if no pty could be allocated, or
 * nonzero if a pty was successfully allocated.  On success, open file
 * descriptors for the pty and tty sides and the name of the tty side are
 * returned (the buffer must be able to hold at least 64 characters).
 */

int 
pty_allocate(int *ptyfd, int *ttyfd, char *namebuf)
{
#ifdef HAVE_OPENPTY
	/* openpty(3) exists in OSF/1 and some other os'es */
	int i;

	i = openpty(ptyfd, ttyfd, namebuf, NULL, NULL);
	if (i < 0) {
		error("openpty: %.100s", strerror(errno));
		return 0;
	}
	return 1;
#else /* HAVE_OPENPTY */
#ifdef HAVE__GETPTY
	/*
	 * _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
	 * pty's automagically when needed
	 */
	char *slave;

	slave = _getpty(ptyfd, O_RDWR, 0622, 0);
	if (slave == NULL) {
		error("_getpty: %.100s", strerror(errno));
		return 0;
	}
	strcpy(namebuf, slave);
	/* Open the slave side. */
	*ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
	if (*ttyfd < 0) {
		error("%.200s: %.100s", namebuf, strerror(errno));
		close(*ptyfd);
		return 0;
	}
	return 1;
#else /* HAVE__GETPTY */
#ifdef HAVE_DEV_PTMX
	/*
	 * This code is used e.g. on Solaris 2.x.  (Note that Solaris 2.3
	 * also has bsd-style ptys, but they simply do not work.)
	 */
	int ptm;
	char *pts;

	ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY);
	if (ptm < 0) {
		error("/dev/ptmx: %.100s", strerror(errno));
		return 0;
	}
	if (grantpt(ptm) < 0) {
		error("grantpt: %.100s", strerror(errno));
		return 0;
	}
	if (unlockpt(ptm) < 0) {
		error("unlockpt: %.100s", strerror(errno));
		return 0;
	}
	pts = ptsname(ptm);
	if (pts == NULL)
		error("Slave pty side name could not be obtained.");
	strcpy(namebuf, pts);
	*ptyfd = ptm;

	/* Open the slave side. */
	*ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
	if (*ttyfd < 0) {
		error("%.100s: %.100s", namebuf, strerror(errno));
		close(*ptyfd);
		return 0;
	}
	/* Push the appropriate streams modules, as described in Solaris pts(7). */
	if (ioctl(*ttyfd, I_PUSH, "ptem") < 0)
		error("ioctl I_PUSH ptem: %.100s", strerror(errno));
	if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0)
		error("ioctl I_PUSH ldterm: %.100s", strerror(errno));
	if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
		error("ioctl I_PUSH ttcompat: %.100s", strerror(errno));
	return 1;
#else /* HAVE_DEV_PTMX */
#ifdef HAVE_DEV_PTS_AND_PTC
	/* AIX-style pty code. */
	const char *name;

	*ptyfd = open("/dev/ptc", O_RDWR | O_NOCTTY);
	if (*ptyfd < 0) {
		error("Could not open /dev/ptc: %.100s", strerror(errno));
		return 0;
	}
	name = ttyname(*ptyfd);
	if (!name)
		fatal("Open of /dev/ptc returns device for which ttyname fails.");
	strcpy(namebuf, name);
	*ttyfd = open(name, O_RDWR | O_NOCTTY);
	if (*ttyfd < 0) {
		error("Could not open pty slave side %.100s: %.100s",
		      name, strerror(errno));
		close(*ptyfd);
		return 0;
	}
	return 1;
#else /* HAVE_DEV_PTS_AND_PTC */
	/* BSD-style pty code. */
	char buf[64];
	int i;
	const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ";
	const char *ptyminors = "0123456789abcdef";
	int num_minors = strlen(ptyminors);
	int num_ptys = strlen(ptymajors) * num_minors;

	for (i = 0; i < num_ptys; i++) {
		snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors],
			 ptyminors[i % num_minors]);
		*ptyfd = open(buf, O_RDWR | O_NOCTTY);
		if (*ptyfd < 0)
			continue;
		snprintf(namebuf, sizeof buf, "/dev/tty%c%c", ptymajors[i / num_minors],
			 ptyminors[i % num_minors]);

		/* Open the slave side. */
		*ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
		if (*ttyfd < 0) {
			error("%.100s: %.100s", namebuf, strerror(errno));
			close(*ptyfd);
			return 0;
		}
		return 1;
	}
	return 0;
#endif /* HAVE_DEV_PTS_AND_PTC */
#endif /* HAVE_DEV_PTMX */
#endif /* HAVE__GETPTY */
#endif /* HAVE_OPENPTY */
}

/* Releases the tty.  Its ownership is returned to root, and permissions to 0666. */

void 
pty_release(const char *ttyname)
{
	if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0)
		debug("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
	if (chmod(ttyname, (mode_t) 0666) < 0)
		debug("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno));
}

/* Makes the tty the processes controlling tty and sets it to sane modes. */

void 
pty_make_controlling_tty(int *ttyfd, const char *ttyname)
{
	int fd;

	/* First disconnect from the old controlling tty. */
#ifdef TIOCNOTTY
	fd = open("/dev/tty", O_RDWR | O_NOCTTY);
	if (fd >= 0) {
		(void) ioctl(fd, TIOCNOTTY, NULL);
		close(fd);
	}
#endif /* TIOCNOTTY */
	if (setsid() < 0)
		error("setsid: %.100s", strerror(errno));

	/*
	 * Verify that we are successfully disconnected from the controlling
	 * tty.
	 */
	fd = open("/dev/tty", O_RDWR | O_NOCTTY);
	if (fd >= 0) {
		error("Failed to disconnect from controlling tty.");
		close(fd);
	}
	/* Make it our controlling tty. */
#ifdef TIOCSCTTY
	debug("Setting controlling tty using TIOCSCTTY.");
	/*
	 * We ignore errors from this, because HPSUX defines TIOCSCTTY, but
	 * returns EINVAL with these arguments, and there is absolutely no
	 * documentation.
	 */
	ioctl(*ttyfd, TIOCSCTTY, NULL);
#endif /* TIOCSCTTY */
	fd = open(ttyname, O_RDWR);
	if (fd < 0)
		error("%.100s: %.100s", ttyname, strerror(errno));
	else
		close(fd);

	/* Verify that we now have a controlling tty. */
	fd = open("/dev/tty", O_WRONLY);
	if (fd < 0)
		error("open /dev/tty failed - could not set controlling tty: %.100s",
		      strerror(errno));
	else {
		close(fd);
	}
}

/* Changes the window size associated with the pty. */

void 
pty_change_window_size(int ptyfd, int row, int col,
		       int xpixel, int ypixel)
{
	struct winsize w;
	w.ws_row = row;
	w.ws_col = col;
	w.ws_xpixel = xpixel;
	w.ws_ypixel = ypixel;
	(void) ioctl(ptyfd, TIOCSWINSZ, &w);
}
Commit	Line	Data
8efc0c15	1	/*
5260325f	2	*
	3	* pty.c
	4	*
	5	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	6	*
	7	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	8	* All rights reserved
	9	*
	10	* Created: Fri Mar 17 04:37:25 1995 ylo
	11	*
	12	* Allocating a pseudo-terminal, and making it the controlling tty.
	13	*
	14	*/
8efc0c15	15
	16	#include "includes.h"
	17	RCSID("$Id$");
	18
5260325f	19	#include "pty.h"
	20	#include "ssh.h"
	21
e1a9c08d	22	#ifdef HAVE_PTY_H
e1a9c08d	23	#include <pty.h>
	24	#endif /* HAVE_PTY_H */
	25
8efc0c15	26	/* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */
	27	#if defined(HAVE__GETPTY) \|\| defined(HAVE_OPENPTY)
	28	#undef HAVE_DEV_PTMX
	29	#endif
	30
	31	#ifndef O_NOCTTY
	32	#define O_NOCTTY 0
	33	#endif
	34
aa3378df	35	/*
	36	* Allocates and opens a pty. Returns 0 if no pty could be allocated, or
	37	* nonzero if a pty was successfully allocated. On success, open file
	38	* descriptors for the pty and tty sides and the name of the tty side are
	39	* returned (the buffer must be able to hold at least 64 characters).
	40	*/
8efc0c15	41
5260325f	42	int
5260325f	43	pty_allocate(int ptyfd, int ttyfd, char *namebuf)
8efc0c15	44	{
8efc0c15	45	#ifdef HAVE_OPENPTY
5260325f	46	/* openpty(3) exists in OSF/1 and some other os'es */
5260325f	47	int i;
8efc0c15	48
5260325f	49	i = openpty(ptyfd, ttyfd, namebuf, NULL, NULL);
	50	if (i < 0) {
	51	error("openpty: %.100s", strerror(errno));
	52	return 0;
	53	}
	54	return 1;
8efc0c15	55	#else /* HAVE_OPENPTY */
8efc0c15	56	#ifdef HAVE__GETPTY
aa3378df	57	/*
	58	* _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
	59	* pty's automagically when needed
	60	*/
5260325f	61	char *slave;
	62
	63	slave = _getpty(ptyfd, O_RDWR, 0622, 0);
	64	if (slave == NULL) {
	65	error("_getpty: %.100s", strerror(errno));
	66	return 0;
	67	}
	68	strcpy(namebuf, slave);
	69	/* Open the slave side. */
	70	*ttyfd = open(namebuf, O_RDWR \| O_NOCTTY);
	71	if (*ttyfd < 0) {
	72	error("%.200s: %.100s", namebuf, strerror(errno));
	73	close(*ptyfd);
	74	return 0;
	75	}
	76	return 1;
8efc0c15	77	#else /* HAVE__GETPTY */
8efc0c15	78	#ifdef HAVE_DEV_PTMX
aa3378df	79	/*
	80	* This code is used e.g. on Solaris 2.x. (Note that Solaris 2.3
	81	* also has bsd-style ptys, but they simply do not work.)
	82	*/
5260325f	83	int ptm;
	84	char *pts;
	85
	86	ptm = open("/dev/ptmx", O_RDWR \| O_NOCTTY);
	87	if (ptm < 0) {
	88	error("/dev/ptmx: %.100s", strerror(errno));
	89	return 0;
	90	}
	91	if (grantpt(ptm) < 0) {
	92	error("grantpt: %.100s", strerror(errno));
	93	return 0;
	94	}
	95	if (unlockpt(ptm) < 0) {
	96	error("unlockpt: %.100s", strerror(errno));
	97	return 0;
	98	}
	99	pts = ptsname(ptm);
	100	if (pts == NULL)
	101	error("Slave pty side name could not be obtained.");
	102	strcpy(namebuf, pts);
	103	*ptyfd = ptm;
	104
	105	/* Open the slave side. */
	106	*ttyfd = open(namebuf, O_RDWR \| O_NOCTTY);
	107	if (*ttyfd < 0) {
	108	error("%.100s: %.100s", namebuf, strerror(errno));
	109	close(*ptyfd);
	110	return 0;
	111	}
aa3378df	112	/* Push the appropriate streams modules, as described in Solaris pts(7). */
5260325f	113	if (ioctl(*ttyfd, I_PUSH, "ptem") < 0)
	114	error("ioctl I_PUSH ptem: %.100s", strerror(errno));
	115	if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0)
	116	error("ioctl I_PUSH ldterm: %.100s", strerror(errno));
	117	if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
	118	error("ioctl I_PUSH ttcompat: %.100s", strerror(errno));
	119	return 1;
8efc0c15	120	#else /* HAVE_DEV_PTMX */
8efc0c15	121	#ifdef HAVE_DEV_PTS_AND_PTC
5260325f	122	/* AIX-style pty code. */
5260325f	123	const char *name;
8efc0c15	124
5260325f	125	*ptyfd = open("/dev/ptc", O_RDWR \| O_NOCTTY);
	126	if (*ptyfd < 0) {
	127	error("Could not open /dev/ptc: %.100s", strerror(errno));
	128	return 0;
	129	}
	130	name = ttyname(*ptyfd);
	131	if (!name)
	132	fatal("Open of /dev/ptc returns device for which ttyname fails.");
	133	strcpy(namebuf, name);
	134	*ttyfd = open(name, O_RDWR \| O_NOCTTY);
	135	if (*ttyfd < 0) {
	136	error("Could not open pty slave side %.100s: %.100s",
	137	name, strerror(errno));
	138	close(*ptyfd);
	139	return 0;
	140	}
	141	return 1;
8efc0c15	142	#else /* HAVE_DEV_PTS_AND_PTC */
5260325f	143	/* BSD-style pty code. */
	144	char buf[64];
	145	int i;
aa3378df	146	const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ";
5260325f	147	const char *ptyminors = "0123456789abcdef";
	148	int num_minors = strlen(ptyminors);
	149	int num_ptys = strlen(ptymajors) * num_minors;
	150
	151	for (i = 0; i < num_ptys; i++) {
	152	snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors],
	153	ptyminors[i % num_minors]);
	154	*ptyfd = open(buf, O_RDWR \| O_NOCTTY);
	155	if (*ptyfd < 0)
	156	continue;
	157	snprintf(namebuf, sizeof buf, "/dev/tty%c%c", ptymajors[i / num_minors],
	158	ptyminors[i % num_minors]);
	159
	160	/* Open the slave side. */
	161	*ttyfd = open(namebuf, O_RDWR \| O_NOCTTY);
	162	if (*ttyfd < 0) {
	163	error("%.100s: %.100s", namebuf, strerror(errno));
	164	close(*ptyfd);
	165	return 0;
	166	}
	167	return 1;
8efc0c15	168	}
5260325f	169	return 0;
8efc0c15	170	#endif /* HAVE_DEV_PTS_AND_PTC */
	171	#endif /* HAVE_DEV_PTMX */
	172	#endif /* HAVE__GETPTY */
	173	#endif /* HAVE_OPENPTY */
	174	}
	175
5260325f	176	/* Releases the tty. Its ownership is returned to root, and permissions to 0666. */
8efc0c15	177
5260325f	178	void
5260325f	179	pty_release(const char *ttyname)
8efc0c15	180	{
5260325f	181	if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0)
	182	debug("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
	183	if (chmod(ttyname, (mode_t) 0666) < 0)
	184	debug("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno));
8efc0c15	185	}
	186
	187	/* Makes the tty the processes controlling tty and sets it to sane modes. */
	188
5260325f	189	void
5260325f	190	pty_make_controlling_tty(int ttyfd, const char ttyname)
8efc0c15	191	{
5260325f	192	int fd;
8efc0c15	193
5260325f	194	/* First disconnect from the old controlling tty. */
8efc0c15	195	#ifdef TIOCNOTTY
5260325f	196	fd = open("/dev/tty", O_RDWR \| O_NOCTTY);
	197	if (fd >= 0) {
	198	(void) ioctl(fd, TIOCNOTTY, NULL);
	199	close(fd);
	200	}
8efc0c15	201	#endif /* TIOCNOTTY */
5260325f	202	if (setsid() < 0)
	203	error("setsid: %.100s", strerror(errno));
	204
aa3378df	205	/*
	206	* Verify that we are successfully disconnected from the controlling
	207	* tty.
	208	*/
5260325f	209	fd = open("/dev/tty", O_RDWR \| O_NOCTTY);
	210	if (fd >= 0) {
	211	error("Failed to disconnect from controlling tty.");
	212	close(fd);
	213	}
	214	/* Make it our controlling tty. */
8efc0c15	215	#ifdef TIOCSCTTY
5260325f	216	debug("Setting controlling tty using TIOCSCTTY.");
aa3378df	217	/*
	218	* We ignore errors from this, because HPSUX defines TIOCSCTTY, but
	219	* returns EINVAL with these arguments, and there is absolutely no
	220	* documentation.
	221	*/
5260325f	222	ioctl(*ttyfd, TIOCSCTTY, NULL);
8efc0c15	223	#endif /* TIOCSCTTY */
5260325f	224	fd = open(ttyname, O_RDWR);
	225	if (fd < 0)
	226	error("%.100s: %.100s", ttyname, strerror(errno));
	227	else
	228	close(fd);
	229
	230	/* Verify that we now have a controlling tty. */
	231	fd = open("/dev/tty", O_WRONLY);
	232	if (fd < 0)
	233	error("open /dev/tty failed - could not set controlling tty: %.100s",
	234	strerror(errno));
	235	else {
	236	close(fd);
	237	}
8efc0c15	238	}
	239
	240	/* Changes the window size associated with the pty. */
	241
5260325f	242	void
	243	pty_change_window_size(int ptyfd, int row, int col,
	244	int xpixel, int ypixel)
8efc0c15	245	{
5260325f	246	struct winsize w;
	247	w.ws_row = row;
	248	w.ws_col = col;
	249	w.ws_xpixel = xpixel;
	250	w.ws_ypixel = ypixel;
	251	(void) ioctl(ptyfd, TIOCSWINSZ, &w);
8efc0c15	252	}