[gssapi-openssh.git] / openssh / sshpty.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: sshpty.c,v 1.3 2001/07/22 21:32:27 markus Exp $");

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

#include "sshpty.h"
#include "log.h"
#include "misc.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 *name;
	int i;

	i = openpty(ptyfd, ttyfd, NULL, NULL, NULL);
	if (i < 0) {
		error("openpty: %.100s", strerror(errno));
		return 0;
	}
	name = ttyname(*ttyfd);
	if (!name)
		fatal("openpty returns device for which ttyname fails.");

	strlcpy(namebuf, name, 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;
	mysig_t old_signal;

	ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY);
	if (ptm < 0) {
		error("/dev/ptmx: %.100s", strerror(errno));
		return 0;
	}
	old_signal = mysignal(SIGCHLD, SIG_DFL);
	if (grantpt(ptm) < 0) {
		error("grantpt: %.100s", strerror(errno));
		return 0;
	}
	mysignal(SIGCHLD, old_signal);
	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 */
#ifdef _CRAY
	char buf[64];
  	int i;
  	int highpty;

#ifdef _SC_CRAY_NPTY
	highpty = sysconf(_SC_CRAY_NPTY);
	if (highpty == -1)
		highpty = 128;
#else
	highpty = 128;
#endif

	for (i = 0; i < highpty; i++) {
		snprintf(buf, sizeof(buf), "/dev/pty/%03d", i);
		*ptyfd = open(buf, O_RDWR|O_NOCTTY);
		if (*ptyfd < 0)
			continue;
		snprintf(namebuf, namebuflen, "/dev/ttyp%03d", i);
		/* 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;
#else
	/* 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 /* CRAY */
#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 */

#ifdef _CRAY
	if (setsid() < 0)
		error("setsid: %.100s", strerror(errno));

	fd = open(ttyname, O_RDWR|O_NOCTTY);
	if (fd != -1) {
		mysignal(SIGHUP, SIG_IGN);
		ioctl(fd, TCVHUP, (char *)NULL);
		mysignal(SIGHUP, SIG_DFL);
		setpgid(0, 0);
		close(fd);
	} else {
		error("Failed to disconnect from controlling tty.");
	}

	debug("Setting controlling tty using TCSETCTTY.");
	ioctl(*ttyfd, TCSETCTTY, NULL);
	fd = open("/dev/tty", O_RDWR);
	if (fd < 0)
		error("%.100s: %.100s", ttyname, strerror(errno));
	close(*ttyfd);
       	*ttyfd = fd;
#else /* _CRAY */

	/* First disconnect from the old controlling tty. */
#ifdef TIOCNOTTY
	fd = open(_PATH_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(_PATH_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 = mysignal(SIGHUP, SIG_IGN);
	vhangup();
	mysignal(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(_PATH_TTY, O_WRONLY);
	if (fd < 0)
		error("open /dev/tty failed - could not set controlling tty: %.100s",
		      strerror(errno));
	else {
		close(fd);
	}
#endif /* _CRAY */
}

/* 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/
	 * tty is owned by root.
	 */
	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 || st.st_uid == 0))
				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
3c0ef626	1	/*
	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	4	* All rights reserved
	5	* Allocating a pseudo-terminal, and making it the controlling tty.
	6	*
	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".
	12	*/
	13
	14	#include "includes.h"
	15	RCSID("$OpenBSD: sshpty.c,v 1.3 2001/07/22 21:32:27 markus Exp $");
	16
	17	#ifdef HAVE_UTIL_H
	18	# include <util.h>
	19	#endif /* HAVE_UTIL_H */
	20
	21	#include "sshpty.h"
	22	#include "log.h"
	23	#include "misc.h"
	24
	25	/* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */
	26	#if defined(HAVE__GETPTY) \|\| defined(HAVE_OPENPTY)
	27	#undef HAVE_DEV_PTMX
	28	#endif
	29
	30	#ifdef HAVE_PTY_H
	31	# include <pty.h>
	32	#endif
	33	#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
	34	# include <sys/stropts.h>
	35	#endif
	36
	37	#ifndef O_NOCTTY
	38	#define O_NOCTTY 0
	39	#endif
	40
	41	/*
	42	* Allocates and opens a pty. Returns 0 if no pty could be allocated, or
	43	* nonzero if a pty was successfully allocated. On success, open file
	44	* descriptors for the pty and tty sides and the name of the tty side are
	45	* returned (the buffer must be able to hold at least 64 characters).
	46	*/
	47
	48	int
	49	pty_allocate(int ptyfd, int ttyfd, char *namebuf, int namebuflen)
	50	{
	51	#if defined(HAVE_OPENPTY) \|\| defined(BSD4_4)
	52	/* openpty(3) exists in OSF/1 and some other os'es */
	53	char *name;
	54	int i;
	55
	56	i = openpty(ptyfd, ttyfd, NULL, NULL, NULL);
	57	if (i < 0) {
	58	error("openpty: %.100s", strerror(errno));
	59	return 0;
	60	}
	61	name = ttyname(*ttyfd);
	62	if (!name)
	63	fatal("openpty returns device for which ttyname fails.");
	64
65	strlcpy(namebuf, name, namebuflen); /* possible truncation */
66	return 1;
67	#else /* HAVE_OPENPTY */
68	#ifdef HAVE__GETPTY
69	/*
70	* _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
71	* pty's automagically when needed
72	*/
73	char *slave;
74
75	slave = _getpty(ptyfd, O_RDWR, 0622, 0);
76	if (slave == NULL) {
77	error("_getpty: %.100s", strerror(errno));
78	return 0;
79	}
80	strlcpy(namebuf, slave, namebuflen);
81	/* Open the slave side. */
82	*ttyfd = open(namebuf, O_RDWR \| O_NOCTTY);
83	if (*ttyfd < 0) {
84	error("%.200s: %.100s", namebuf, strerror(errno));
85	close(*ptyfd);
86	return 0;
87	}
88	return 1;
89	#else /* HAVE__GETPTY */
90	#if defined(HAVE_DEV_PTMX)
91	/*
92	* This code is used e.g. on Solaris 2.x. (Note that Solaris 2.3
93	* also has bsd-style ptys, but they simply do not work.)
94	*/
95	int ptm;
96	char *pts;
97	mysig_t old_signal;
98
99	ptm = open("/dev/ptmx", O_RDWR \| O_NOCTTY);
100	if (ptm < 0) {
101	error("/dev/ptmx: %.100s", strerror(errno));
102	return 0;
103	}
104	old_signal = mysignal(SIGCHLD, SIG_DFL);
105	if (grantpt(ptm) < 0) {
106	error("grantpt: %.100s", strerror(errno));
107	return 0;
108	}
109	mysignal(SIGCHLD, old_signal);
110	if (unlockpt(ptm) < 0) {
111	error("unlockpt: %.100s", strerror(errno));
112	return 0;
113	}
114	pts = ptsname(ptm);
115	if (pts == NULL)
116	error("Slave pty side name could not be obtained.");
117	strlcpy(namebuf, pts, namebuflen);
118	*ptyfd = ptm;
119
120	/* Open the slave side. */
121	*ttyfd = open(namebuf, O_RDWR \| O_NOCTTY);
122	if (*ttyfd < 0) {
123	error("%.100s: %.100s", namebuf, strerror(errno));
124	close(*ptyfd);
125	return 0;
126	}
127	#ifndef HAVE_CYGWIN
128	/*
129	* Push the appropriate streams modules, as described in Solaris pts(7).
130	* HP-UX pts(7) doesn't have ttcompat module.
131	*/
132	if (ioctl(*ttyfd, I_PUSH, "ptem") < 0)
133	error("ioctl I_PUSH ptem: %.100s", strerror(errno));
134	if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0)
135	error("ioctl I_PUSH ldterm: %.100s", strerror(errno));
136	#ifndef __hpux
137	if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
138	error("ioctl I_PUSH ttcompat: %.100s", strerror(errno));
139	#endif
140	#endif
141	return 1;
142	#else /* HAVE_DEV_PTMX */
143	#ifdef HAVE_DEV_PTS_AND_PTC
144	/* AIX-style pty code. */
145	const char *name;
146
147	*ptyfd = open("/dev/ptc", O_RDWR \| O_NOCTTY);
148	if (*ptyfd < 0) {
149	error("Could not open /dev/ptc: %.100s", strerror(errno));
150	return 0;
151	}
152	name = ttyname(*ptyfd);
153	if (!name)
154	fatal("Open of /dev/ptc returns device for which ttyname fails.");
155	strlcpy(namebuf, name, namebuflen);
156	*ttyfd = open(name, O_RDWR \| O_NOCTTY);
157	if (*ttyfd < 0) {
158	error("Could not open pty slave side %.100s: %.100s",
159	name, strerror(errno));
160	close(*ptyfd);
161	return 0;
162	}
163	return 1;
164	#else /* HAVE_DEV_PTS_AND_PTC */
165	#ifdef _CRAY
166	char buf[64];
167	int i;
168	int highpty;
169
170	#ifdef _SC_CRAY_NPTY
171	highpty = sysconf(_SC_CRAY_NPTY);
172	if (highpty == -1)
173	highpty = 128;
174	#else
175	highpty = 128;
176	#endif
177
178	for (i = 0; i < highpty; i++) {
179	snprintf(buf, sizeof(buf), "/dev/pty/%03d", i);
180	*ptyfd = open(buf, O_RDWR\|O_NOCTTY);
181	if (*ptyfd < 0)
182	continue;
183	snprintf(namebuf, namebuflen, "/dev/ttyp%03d", i);
184	/* Open the slave side. */
185	*ttyfd = open(namebuf, O_RDWR\|O_NOCTTY);
186	if (*ttyfd < 0) {
187	error("%.100s: %.100s", namebuf, strerror(errno));
188	close(*ptyfd);
189	return 0;
190	}
191	return 1;
192	}
193	return 0;
194	#else
195	/* BSD-style pty code. */
196	char buf[64];
197	int i;
198	const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ";
199	const char *ptyminors = "0123456789abcdef";
200	int num_minors = strlen(ptyminors);
201	int num_ptys = strlen(ptymajors) * num_minors;
202
203	for (i = 0; i < num_ptys; i++) {
204	snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors],
205	ptyminors[i % num_minors]);
206	snprintf(namebuf, namebuflen, "/dev/tty%c%c",
207	ptymajors[i / num_minors], ptyminors[i % num_minors]);
208
209	*ptyfd = open(buf, O_RDWR \| O_NOCTTY);
210	if (*ptyfd < 0) {
211	/* Try SCO style naming */
212	snprintf(buf, sizeof buf, "/dev/ptyp%d", i);
213	snprintf(namebuf, namebuflen, "/dev/ttyp%d", i);
214	*ptyfd = open(buf, O_RDWR \| O_NOCTTY);
215	if (*ptyfd < 0)
216	continue;
217	}
218
219	/* Open the slave side. */
220	*ttyfd = open(namebuf, O_RDWR \| O_NOCTTY);
221	if (*ttyfd < 0) {
222	error("%.100s: %.100s", namebuf, strerror(errno));
223	close(*ptyfd);
224	return 0;
225	}
226	return 1;
227	}
228	return 0;
229	#endif /* CRAY */
230	#endif /* HAVE_DEV_PTS_AND_PTC */
231	#endif /* HAVE_DEV_PTMX */
232	#endif /* HAVE__GETPTY */
233	#endif /* HAVE_OPENPTY */
234	}
235
236	/* Releases the tty. Its ownership is returned to root, and permissions to 0666. */
237
238	void
239	pty_release(const char *ttyname)
240	{
241	if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0)
242	error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
243	if (chmod(ttyname, (mode_t) 0666) < 0)
244	error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno));
245	}
246
247	/* Makes the tty the processes controlling tty and sets it to sane modes. */
248
249	void
250	pty_make_controlling_tty(int ttyfd, const char ttyname)
251	{
252	int fd;
253	#ifdef USE_VHANGUP
254	void *old;
255	#endif /* USE_VHANGUP */
256
257	#ifdef _CRAY
258	if (setsid() < 0)
259	error("setsid: %.100s", strerror(errno));
260
261	fd = open(ttyname, O_RDWR\|O_NOCTTY);
262	if (fd != -1) {
263	mysignal(SIGHUP, SIG_IGN);
264	ioctl(fd, TCVHUP, (char *)NULL);
265	mysignal(SIGHUP, SIG_DFL);
266	setpgid(0, 0);
267	close(fd);
268	} else {
269	error("Failed to disconnect from controlling tty.");
270	}
271
272	debug("Setting controlling tty using TCSETCTTY.");
273	ioctl(*ttyfd, TCSETCTTY, NULL);
274	fd = open("/dev/tty", O_RDWR);
275	if (fd < 0)
276	error("%.100s: %.100s", ttyname, strerror(errno));
277	close(*ttyfd);
278	*ttyfd = fd;
279	#else /* _CRAY */
280
281	/* First disconnect from the old controlling tty. */
282	#ifdef TIOCNOTTY
283	fd = open(_PATH_TTY, O_RDWR \| O_NOCTTY);
284	if (fd >= 0) {
285	(void) ioctl(fd, TIOCNOTTY, NULL);
286	close(fd);
287	}
288	#endif /* TIOCNOTTY */
289	if (setsid() < 0)
290	error("setsid: %.100s", strerror(errno));
291
292	/*
293	* Verify that we are successfully disconnected from the controlling
294	* tty.
295	*/
296	fd = open(_PATH_TTY, O_RDWR \| O_NOCTTY);
297	if (fd >= 0) {
298	error("Failed to disconnect from controlling tty.");
299	close(fd);
300	}
301	/* Make it our controlling tty. */
302	#ifdef TIOCSCTTY
303	debug("Setting controlling tty using TIOCSCTTY.");
304	if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0)
305	error("ioctl(TIOCSCTTY): %.100s", strerror(errno));
306	#endif /* TIOCSCTTY */
307	#ifdef HAVE_NEWS4
308	if (setpgrp(0,0) < 0)
309	error("SETPGRP %s",strerror(errno));
310	#endif /* HAVE_NEWS4 */
311	#ifdef USE_VHANGUP
312	old = mysignal(SIGHUP, SIG_IGN);
313	vhangup();
314	mysignal(SIGHUP, old);
315	#endif /* USE_VHANGUP */
316	fd = open(ttyname, O_RDWR);
317	if (fd < 0) {
318	error("%.100s: %.100s", ttyname, strerror(errno));
319	} else {
320	#ifdef USE_VHANGUP
321	close(*ttyfd);
322	*ttyfd = fd;
323	#else /* USE_VHANGUP */
324	close(fd);
325	#endif /* USE_VHANGUP */
326	}
327	/* Verify that we now have a controlling tty. */
328	fd = open(_PATH_TTY, O_WRONLY);
329	if (fd < 0)
330	error("open /dev/tty failed - could not set controlling tty: %.100s",
331	strerror(errno));
332	else {
333	close(fd);
334	}
335	#endif /* _CRAY */
336	}
337
338	/* Changes the window size associated with the pty. */
339
340	void
341	pty_change_window_size(int ptyfd, int row, int col,
342	int xpixel, int ypixel)
343	{
344	struct winsize w;
345	w.ws_row = row;
346	w.ws_col = col;
347	w.ws_xpixel = xpixel;
348	w.ws_ypixel = ypixel;
349	(void) ioctl(ptyfd, TIOCSWINSZ, &w);
350	}
351
352	void
353	pty_setowner(struct passwd pw, const char ttyname)
354	{
355	struct group *grp;
356	gid_t gid;
357	mode_t mode;
358	struct stat st;
359
360	/* Determine the group to make the owner of the tty. */
361	grp = getgrnam("tty");
362	if (grp) {
363	gid = grp->gr_gid;
364	mode = S_IRUSR \| S_IWUSR \| S_IWGRP;
365	} else {
366	gid = pw->pw_gid;
367	mode = S_IRUSR \| S_IWUSR \| S_IWGRP \| S_IWOTH;
368	}
369
370	/*
371	* Change owner and mode of the tty as required.
372	* Warn but continue if filesystem is read-only and the uids match/
373	* tty is owned by root.
374	*/
375	if (stat(ttyname, &st))
376	fatal("stat(%.100s) failed: %.100s", ttyname,
377	strerror(errno));
378
379	if (st.st_uid != pw->pw_uid \|\| st.st_gid != gid) {
380	if (chown(ttyname, pw->pw_uid, gid) < 0) {
381	if (errno == EROFS &&
382	(st.st_uid == pw->pw_uid \|\| st.st_uid == 0))
383	error("chown(%.100s, %d, %d) failed: %.100s",
384	ttyname, pw->pw_uid, gid,
385	strerror(errno));
386	else
387	fatal("chown(%.100s, %d, %d) failed: %.100s",
388	ttyname, pw->pw_uid, gid,
389	strerror(errno));
390	}
391	}
392
393	if ((st.st_mode & (S_IRWXU\|S_IRWXG\|S_IRWXO)) != mode) {
394	if (chmod(ttyname, mode) < 0) {
395	if (errno == EROFS &&
396	(st.st_mode & (S_IRGRP \| S_IROTH)) == 0)
397	error("chmod(%.100s, 0%o) failed: %.100s",
398	ttyname, mode, strerror(errno));
399	else
400	fatal("chmod(%.100s, 0%o) failed: %.100s",
401	ttyname, mode, strerror(errno));
402	}
403	}
404	}