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