[openssh.git] / pty.c

/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * Allocating a pseudo-terminal, and making it the controlling tty.
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 */

#include "includes.h"
RCSID("$OpenBSD: pty.c,v 1.20 2001/01/21 19:05:53 markus Exp $");

#ifdef HAVE_UTIL_H
# include <util.h>
#endif /* HAVE_UTIL_H */

#include "pty.h"
#include "log.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

#ifdef HAVE_PTY_H
# include <pty.h>
#endif
#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
# include <sys/stropts.h>
#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, int namebuflen)
{
#if defined(HAVE_OPENPTY) || defined(BSD4_4)
	/* openpty(3) exists in OSF/1 and some other os'es */
	char buf[64];
	int i;

	i = openpty(ptyfd, ttyfd, buf, NULL, NULL);
	if (i < 0) {
		error("openpty: %.100s", strerror(errno));
		return 0;
	}
	strlcpy(namebuf, buf, namebuflen);	/* possible truncation */
	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;
	}
	strlcpy(namebuf, slave, namebuflen);
	/* 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 */
#if defined(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.");
	strlcpy(namebuf, pts, namebuflen);
	*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;
	}
#ifndef HAVE_CYGWIN
	/*
	 * Push the appropriate streams modules, as described in Solaris pts(7).
	 * HP-UX pts(7) doesn't have ttcompat module.
	 */
	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));
#ifndef __hpux
	if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
		error("ioctl I_PUSH ttcompat: %.100s", strerror(errno));
#endif
#endif
	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.");
	strlcpy(namebuf, name, namebuflen);
	*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]);
		snprintf(namebuf, namebuflen, "/dev/tty%c%c",
		    ptymajors[i / num_minors], ptyminors[i % num_minors]);

		*ptyfd = open(buf, O_RDWR | O_NOCTTY);
		if (*ptyfd < 0) {
			/* Try SCO style naming */
			snprintf(buf, sizeof buf, "/dev/ptyp%d", i);
			snprintf(namebuf, namebuflen, "/dev/ttyp%d", i);
			*ptyfd = open(buf, O_RDWR | O_NOCTTY);
			if (*ptyfd < 0)
				continue;
		}

		/* 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)
		error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
	if (chmod(ttyname, (mode_t) 0666) < 0)
		error("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;
#ifdef USE_VHANGUP
	void *old;
#endif /* USE_VHANGUP */

	/* 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.");
	if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0)
		error("ioctl(TIOCSCTTY): %.100s", strerror(errno));
#endif /* TIOCSCTTY */
#ifdef HAVE_NEWS4
	if (setpgrp(0,0) < 0)
		error("SETPGRP %s",strerror(errno));
#endif /* HAVE_NEWS4 */
#ifdef USE_VHANGUP
	old = signal(SIGHUP, SIG_IGN);
	vhangup();
	signal(SIGHUP, old);
#endif /* USE_VHANGUP */
	fd = open(ttyname, O_RDWR);
	if (fd < 0) {
		error("%.100s: %.100s", ttyname, strerror(errno));
	} else {
#ifdef USE_VHANGUP
		close(*ttyfd);
		*ttyfd = fd;
#else /* USE_VHANGUP */
		close(fd);
#endif /* USE_VHANGUP */
	}
	/* 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);
}

void
pty_setowner(struct passwd *pw, const char *ttyname)
{
	struct group *grp;
	gid_t gid;
	mode_t mode;
	struct stat st;

	/* Determine the group to make the owner of the tty. */
	grp = getgrnam("tty");
	if (grp) {
		gid = grp->gr_gid;
		mode = S_IRUSR | S_IWUSR | S_IWGRP;
	} else {
		gid = pw->pw_gid;
		mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
	}

	/*
	 * Change owner and mode of the tty as required.
	 * Warn but continue if filesystem is read-only and the uids match.
	 */
	if (stat(ttyname, &st))
		fatal("stat(%.100s) failed: %.100s", ttyname,
		    strerror(errno));

	if (st.st_uid != pw->pw_uid || st.st_gid != gid) {
		if (chown(ttyname, pw->pw_uid, gid) < 0) {
			if (errno == EROFS && st.st_uid == pw->pw_uid)
				error("chown(%.100s, %d, %d) failed: %.100s",
				      ttyname, pw->pw_uid, gid,
				      strerror(errno));
			else
				fatal("chown(%.100s, %d, %d) failed: %.100s",
				      ttyname, pw->pw_uid, gid,
				      strerror(errno));
		}
	}

	if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != mode) {
		if (chmod(ttyname, mode) < 0) {
			if (errno == EROFS &&
			    (st.st_mode & (S_IRGRP | S_IROTH)) == 0)
				error("chmod(%.100s, 0%o) failed: %.100s",
				      ttyname, mode, strerror(errno));
			else
				fatal("chmod(%.100s, 0%o) failed: %.100s",
				      ttyname, mode, strerror(errno));
		}
	}
}
Commit	Line	Data
8efc0c15	1	/*
5260325f	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
5260325f	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5260325f	4	* All rights reserved
5260325f	5	* Allocating a pseudo-terminal, and making it the controlling tty.
6ae2364d	6	*
bcbf86ec	7	* As far as I am concerned, the code I have written for this software
	8	* can be used freely for any purpose. Any derived versions of this
	9	* software must be clearly marked as such, and if the derived work is
	10	* incompatible with the protocol description in the RFC file, it must be
	11	* called by a name other than "ssh" or "Secure Shell".
5260325f	12	*/
8efc0c15	13
8efc0c15	14	#include "includes.h"
42f11eb2	15	RCSID("$OpenBSD: pty.c,v 1.20 2001/01/21 19:05:53 markus Exp $");
8efc0c15	16
884bcb37	17	#ifdef HAVE_UTIL_H
	18	# include <util.h>
	19	#endif /* HAVE_UTIL_H */
	20
5260325f	21	#include "pty.h"
42f11eb2	22	#include "log.h"
5260325f	23
8efc0c15	24	/* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */
	25	#if defined(HAVE__GETPTY) \|\| defined(HAVE_OPENPTY)
	26	#undef HAVE_DEV_PTMX
	27	#endif
	28
6d8c4ea4	29	#ifdef HAVE_PTY_H
	30	# include <pty.h>
	31	#endif
	32	#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
	33	# include <sys/stropts.h>
	34	#endif
	35
8efc0c15	36	#ifndef O_NOCTTY
	37	#define O_NOCTTY 0
	38	#endif
	39
aa3378df	40	/*
	41	* Allocates and opens a pty. Returns 0 if no pty could be allocated, or
	42	* nonzero if a pty was successfully allocated. On success, open file
	43	* descriptors for the pty and tty sides and the name of the tty side are
	44	* returned (the buffer must be able to hold at least 64 characters).
	45	*/
8efc0c15	46
6ae2364d	47	int
a408af76	48	pty_allocate(int ptyfd, int ttyfd, char *namebuf, int namebuflen)
8efc0c15	49	{
a408af76	50	#if defined(HAVE_OPENPTY) \|\| defined(BSD4_4)
5260325f	51	/* openpty(3) exists in OSF/1 and some other os'es */
a408af76	52	char buf[64];
5260325f	53	int i;
8efc0c15	54
a408af76	55	i = openpty(ptyfd, ttyfd, buf, NULL, NULL);
5260325f	56	if (i < 0) {
	57	error("openpty: %.100s", strerror(errno));
	58	return 0;
	59	}
a408af76	60	strlcpy(namebuf, buf, namebuflen); /* possible truncation */
5260325f	61	return 1;
8efc0c15	62	#else /* HAVE_OPENPTY */
8efc0c15	63	#ifdef HAVE__GETPTY
aa3378df	64	/*
	65	* _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
	66	* pty's automagically when needed
	67	*/
5260325f	68	char *slave;
	69
	70	slave = _getpty(ptyfd, O_RDWR, 0622, 0);
	71	if (slave == NULL) {
	72	error("_getpty: %.100s", strerror(errno));
	73	return 0;
	74	}
a408af76	75	strlcpy(namebuf, slave, namebuflen);
5260325f	76	/* Open the slave side. */
	77	*ttyfd = open(namebuf, O_RDWR \| O_NOCTTY);
	78	if (*ttyfd < 0) {
	79	error("%.200s: %.100s", namebuf, strerror(errno));
	80	close(*ptyfd);
	81	return 0;
	82	}
	83	return 1;
8efc0c15	84	#else /* HAVE__GETPTY */
a7effaac	85	#if defined(HAVE_DEV_PTMX)
aa3378df	86	/*
	87	* This code is used e.g. on Solaris 2.x. (Note that Solaris 2.3
	88	* also has bsd-style ptys, but they simply do not work.)
	89	*/
5260325f	90	int ptm;
	91	char *pts;
	92
	93	ptm = open("/dev/ptmx", O_RDWR \| O_NOCTTY);
	94	if (ptm < 0) {
	95	error("/dev/ptmx: %.100s", strerror(errno));
	96	return 0;
	97	}
	98	if (grantpt(ptm) < 0) {
	99	error("grantpt: %.100s", strerror(errno));
	100	return 0;
	101	}
	102	if (unlockpt(ptm) < 0) {
	103	error("unlockpt: %.100s", strerror(errno));
	104	return 0;
	105	}
	106	pts = ptsname(ptm);
	107	if (pts == NULL)
	108	error("Slave pty side name could not be obtained.");
a408af76	109	strlcpy(namebuf, pts, namebuflen);
5260325f	110	*ptyfd = ptm;
	111
	112	/* Open the slave side. */
	113	*ttyfd = open(namebuf, O_RDWR \| O_NOCTTY);
	114	if (*ttyfd < 0) {
	115	error("%.100s: %.100s", namebuf, strerror(errno));
	116	close(*ptyfd);
	117	return 0;
	118	}
3c62e7eb	119	#ifndef HAVE_CYGWIN
96054e6f	120	/*
	121	* Push the appropriate streams modules, as described in Solaris pts(7).
	122	* HP-UX pts(7) doesn't have ttcompat module.
	123	*/
5260325f	124	if (ioctl(*ttyfd, I_PUSH, "ptem") < 0)
	125	error("ioctl I_PUSH ptem: %.100s", strerror(errno));
	126	if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0)
	127	error("ioctl I_PUSH ldterm: %.100s", strerror(errno));
96054e6f	128	#ifndef __hpux
5260325f	129	if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
5260325f	130	error("ioctl I_PUSH ttcompat: %.100s", strerror(errno));
3c62e7eb	131	#endif
be48d23c	132	#endif
5260325f	133	return 1;
8efc0c15	134	#else /* HAVE_DEV_PTMX */
8efc0c15	135	#ifdef HAVE_DEV_PTS_AND_PTC
5260325f	136	/* AIX-style pty code. */
5260325f	137	const char *name;
8efc0c15	138
5260325f	139	*ptyfd = open("/dev/ptc", O_RDWR \| O_NOCTTY);
	140	if (*ptyfd < 0) {
	141	error("Could not open /dev/ptc: %.100s", strerror(errno));
	142	return 0;
	143	}
	144	name = ttyname(*ptyfd);
	145	if (!name)
	146	fatal("Open of /dev/ptc returns device for which ttyname fails.");
a408af76	147	strlcpy(namebuf, name, namebuflen);
5260325f	148	*ttyfd = open(name, O_RDWR \| O_NOCTTY);
	149	if (*ttyfd < 0) {
	150	error("Could not open pty slave side %.100s: %.100s",
	151	name, strerror(errno));
	152	close(*ptyfd);
	153	return 0;
	154	}
	155	return 1;
8efc0c15	156	#else /* HAVE_DEV_PTS_AND_PTC */
5260325f	157	/* BSD-style pty code. */
	158	char buf[64];
	159	int i;
aa3378df	160	const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ";
5260325f	161	const char *ptyminors = "0123456789abcdef";
	162	int num_minors = strlen(ptyminors);
	163	int num_ptys = strlen(ptymajors) * num_minors;
	164
	165	for (i = 0; i < num_ptys; i++) {
	166	snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors],
	167	ptyminors[i % num_minors]);
95f1eccc	168	snprintf(namebuf, namebuflen, "/dev/tty%c%c",
a408af76	169	ptymajors[i / num_minors], ptyminors[i % num_minors]);
5260325f	170
b5f90139	171	*ptyfd = open(buf, O_RDWR \| O_NOCTTY);
	172	if (*ptyfd < 0) {
	173	/* Try SCO style naming */
	174	snprintf(buf, sizeof buf, "/dev/ptyp%d", i);
	175	snprintf(namebuf, namebuflen, "/dev/ttyp%d", i);
	176	*ptyfd = open(buf, O_RDWR \| O_NOCTTY);
	177	if (*ptyfd < 0)
	178	continue;
2b87da3b	179	}
2b87da3b	180
5260325f	181	/* Open the slave side. */
	182	*ttyfd = open(namebuf, O_RDWR \| O_NOCTTY);
	183	if (*ttyfd < 0) {
	184	error("%.100s: %.100s", namebuf, strerror(errno));
	185	close(*ptyfd);
	186	return 0;
	187	}
	188	return 1;
8efc0c15	189	}
5260325f	190	return 0;
8efc0c15	191	#endif /* HAVE_DEV_PTS_AND_PTC */
	192	#endif /* HAVE_DEV_PTMX */
	193	#endif /* HAVE__GETPTY */
	194	#endif /* HAVE_OPENPTY */
	195	}
	196
5260325f	197	/* Releases the tty. Its ownership is returned to root, and permissions to 0666. */
8efc0c15	198
6ae2364d	199	void
5260325f	200	pty_release(const char *ttyname)
8efc0c15	201	{
3276571c	202	if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0)
817175bc	203	error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
3276571c	204	if (chmod(ttyname, (mode_t) 0666) < 0)
817175bc	205	error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno));
8efc0c15	206	}
	207
	208	/* Makes the tty the processes controlling tty and sets it to sane modes. */
	209
6ae2364d	210	void
5260325f	211	pty_make_controlling_tty(int ttyfd, const char ttyname)
8efc0c15	212	{
5260325f	213	int fd;
3c62e7eb	214	#ifdef USE_VHANGUP
4e577b89	215	void *old;
3c62e7eb	216	#endif /* USE_VHANGUP */
8efc0c15	217
5260325f	218	/* First disconnect from the old controlling tty. */
8efc0c15	219	#ifdef TIOCNOTTY
5260325f	220	fd = open("/dev/tty", O_RDWR \| O_NOCTTY);
	221	if (fd >= 0) {
	222	(void) ioctl(fd, TIOCNOTTY, NULL);
	223	close(fd);
	224	}
8efc0c15	225	#endif /* TIOCNOTTY */
5260325f	226	if (setsid() < 0)
	227	error("setsid: %.100s", strerror(errno));
	228
aa3378df	229	/*
	230	* Verify that we are successfully disconnected from the controlling
	231	* tty.
	232	*/
5260325f	233	fd = open("/dev/tty", O_RDWR \| O_NOCTTY);
	234	if (fd >= 0) {
	235	error("Failed to disconnect from controlling tty.");
	236	close(fd);
	237	}
	238	/* Make it our controlling tty. */
8efc0c15	239	#ifdef TIOCSCTTY
5260325f	240	debug("Setting controlling tty using TIOCSCTTY.");
a3bf38d0	241	if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0)
a3bf38d0	242	error("ioctl(TIOCSCTTY): %.100s", strerror(errno));
8efc0c15	243	#endif /* TIOCSCTTY */
66d6c27e	244	#ifdef HAVE_NEWS4
	245	if (setpgrp(0,0) < 0)
	246	error("SETPGRP %s",strerror(errno));
	247	#endif /* HAVE_NEWS4 */
3c62e7eb	248	#ifdef USE_VHANGUP
4e577b89	249	old = signal(SIGHUP, SIG_IGN);
	250	vhangup();
	251	signal(SIGHUP, old);
3c62e7eb	252	#endif /* USE_VHANGUP */
5260325f	253	fd = open(ttyname, O_RDWR);
4e577b89	254	if (fd < 0) {
5260325f	255	error("%.100s: %.100s", ttyname, strerror(errno));
4e577b89	256	} else {
3c62e7eb	257	#ifdef USE_VHANGUP
4e577b89	258	close(*ttyfd);
4e577b89	259	*ttyfd = fd;
3c62e7eb	260	#else /* USE_VHANGUP */
5260325f	261	close(fd);
3c62e7eb	262	#endif /* USE_VHANGUP */
4e577b89	263	}
5260325f	264	/* Verify that we now have a controlling tty. */
	265	fd = open("/dev/tty", O_WRONLY);
	266	if (fd < 0)
	267	error("open /dev/tty failed - could not set controlling tty: %.100s",
	268	strerror(errno));
	269	else {
	270	close(fd);
	271	}
8efc0c15	272	}
	273
	274	/* Changes the window size associated with the pty. */
	275
6ae2364d	276	void
5260325f	277	pty_change_window_size(int ptyfd, int row, int col,
5260325f	278	int xpixel, int ypixel)
8efc0c15	279	{
5260325f	280	struct winsize w;
	281	w.ws_row = row;
	282	w.ws_col = col;
	283	w.ws_xpixel = xpixel;
	284	w.ws_ypixel = ypixel;
	285	(void) ioctl(ptyfd, TIOCSWINSZ, &w);
8efc0c15	286	}
817175bc	287
	288	void
	289	pty_setowner(struct passwd pw, const char ttyname)
	290	{
	291	struct group *grp;
	292	gid_t gid;
	293	mode_t mode;
227e8e86	294	struct stat st;
817175bc	295
	296	/* Determine the group to make the owner of the tty. */
	297	grp = getgrnam("tty");
	298	if (grp) {
	299	gid = grp->gr_gid;
	300	mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
	301	} else {
	302	gid = pw->pw_gid;
	303	mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
	304	}
	305
227e8e86	306	/*
	307	* Change owner and mode of the tty as required.
	308	* Warn but continue if filesystem is read-only and the uids match.
	309	*/
	310	if (stat(ttyname, &st))
	311	fatal("stat(%.100s) failed: %.100s", ttyname,
	312	strerror(errno));
	313
	314	if (st.st_uid != pw->pw_uid \|\| st.st_gid != gid) {
	315	if (chown(ttyname, pw->pw_uid, gid) < 0) {
	316	if (errno == EROFS && st.st_uid == pw->pw_uid)
	317	error("chown(%.100s, %d, %d) failed: %.100s",
2b87da3b	318	ttyname, pw->pw_uid, gid,
227e8e86	319	strerror(errno));
	320	else
	321	fatal("chown(%.100s, %d, %d) failed: %.100s",
2b87da3b	322	ttyname, pw->pw_uid, gid,
227e8e86	323	strerror(errno));
	324	}
	325	}
	326
	327	if ((st.st_mode & (S_IRWXU\|S_IRWXG\|S_IRWXO)) != mode) {
	328	if (chmod(ttyname, mode) < 0) {
	329	if (errno == EROFS &&
	330	(st.st_mode & (S_IRGRP \| S_IROTH)) == 0)
	331	error("chmod(%.100s, 0%o) failed: %.100s",
	332	ttyname, mode, strerror(errno));
	333	else
	334	fatal("chmod(%.100s, 0%o) failed: %.100s",
	335	ttyname, mode, strerror(errno));
	336	}
	337	}
817175bc	338	}