2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * Allocating a pseudo-terminal, and making it the controlling tty.
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".
15 RCSID("$OpenBSD: pty.c,v 1.16 2000/09/07 21:13:37 markus Exp $");
19 #endif /* HAVE_UTIL_H */
24 /* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */
25 #if defined(HAVE__GETPTY) || defined(HAVE_OPENPTY)
32 #if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
33 # include <sys/stropts.h>
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).
48 pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen)
50 #if defined(HAVE_OPENPTY) || defined(BSD4_4)
51 /* openpty(3) exists in OSF/1 and some other os'es */
55 i = openpty(ptyfd, ttyfd, buf, NULL, NULL);
57 error("openpty: %.100s", strerror(errno));
60 strlcpy(namebuf, buf, namebuflen); /* possible truncation */
62 #else /* HAVE_OPENPTY */
65 * _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
66 * pty's automagically when needed
70 slave = _getpty(ptyfd, O_RDWR, 0622, 0);
72 error("_getpty: %.100s", strerror(errno));
75 strlcpy(namebuf, slave, namebuflen);
76 /* Open the slave side. */
77 *ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
79 error("%.200s: %.100s", namebuf, strerror(errno));
84 #else /* HAVE__GETPTY */
85 #if defined(HAVE_DEV_PTMX)
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.)
93 ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY);
95 error("/dev/ptmx: %.100s", strerror(errno));
98 if (grantpt(ptm) < 0) {
99 error("grantpt: %.100s", strerror(errno));
102 if (unlockpt(ptm) < 0) {
103 error("unlockpt: %.100s", strerror(errno));
108 error("Slave pty side name could not be obtained.");
109 strlcpy(namebuf, pts, namebuflen);
112 /* Open the slave side. */
113 *ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
115 error("%.100s: %.100s", namebuf, strerror(errno));
120 /* Push the appropriate streams modules, as described in Solaris pts(7). */
121 if (ioctl(*ttyfd, I_PUSH, "ptem") < 0)
122 error("ioctl I_PUSH ptem: %.100s", strerror(errno));
123 if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0)
124 error("ioctl I_PUSH ldterm: %.100s", strerror(errno));
126 if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
127 error("ioctl I_PUSH ttcompat: %.100s", strerror(errno));
131 #else /* HAVE_DEV_PTMX */
132 #ifdef HAVE_DEV_PTS_AND_PTC
133 /* AIX-style pty code. */
136 *ptyfd = open("/dev/ptc", O_RDWR | O_NOCTTY);
138 error("Could not open /dev/ptc: %.100s", strerror(errno));
141 name = ttyname(*ptyfd);
143 fatal("Open of /dev/ptc returns device for which ttyname fails.");
144 strlcpy(namebuf, name, namebuflen);
145 *ttyfd = open(name, O_RDWR | O_NOCTTY);
147 error("Could not open pty slave side %.100s: %.100s",
148 name, strerror(errno));
153 #else /* HAVE_DEV_PTS_AND_PTC */
154 /* BSD-style pty code. */
157 const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ";
158 const char *ptyminors = "0123456789abcdef";
159 int num_minors = strlen(ptyminors);
160 int num_ptys = strlen(ptymajors) * num_minors;
162 for (i = 0; i < num_ptys; i++) {
163 snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors],
164 ptyminors[i % num_minors]);
165 snprintf(namebuf, namebuflen, "/dev/tty%c%c",
166 ptymajors[i / num_minors], ptyminors[i % num_minors]);
168 *ptyfd = open(buf, O_RDWR | O_NOCTTY);
170 /* Try SCO style naming */
171 snprintf(buf, sizeof buf, "/dev/ptyp%d", i);
172 snprintf(namebuf, namebuflen, "/dev/ttyp%d", i);
173 *ptyfd = open(buf, O_RDWR | O_NOCTTY);
178 /* Open the slave side. */
179 *ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
181 error("%.100s: %.100s", namebuf, strerror(errno));
188 #endif /* HAVE_DEV_PTS_AND_PTC */
189 #endif /* HAVE_DEV_PTMX */
190 #endif /* HAVE__GETPTY */
191 #endif /* HAVE_OPENPTY */
194 /* Releases the tty. Its ownership is returned to root, and permissions to 0666. */
197 pty_release(const char *ttyname)
199 if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0)
200 error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
201 if (chmod(ttyname, (mode_t) 0666) < 0)
202 error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno));
205 /* Makes the tty the processes controlling tty and sets it to sane modes. */
208 pty_make_controlling_tty(int *ttyfd, const char *ttyname)
213 #endif /* USE_VHANGUP */
215 /* First disconnect from the old controlling tty. */
217 fd = open("/dev/tty", O_RDWR | O_NOCTTY);
219 (void) ioctl(fd, TIOCNOTTY, NULL);
222 #endif /* TIOCNOTTY */
224 error("setsid: %.100s", strerror(errno));
227 * Verify that we are successfully disconnected from the controlling
230 fd = open("/dev/tty", O_RDWR | O_NOCTTY);
232 error("Failed to disconnect from controlling tty.");
235 /* Make it our controlling tty. */
237 debug("Setting controlling tty using TIOCSCTTY.");
239 * We ignore errors from this, because HPSUX defines TIOCSCTTY, but
240 * returns EINVAL with these arguments, and there is absolutely no
243 ioctl(*ttyfd, TIOCSCTTY, NULL);
244 #endif /* TIOCSCTTY */
246 old = signal(SIGHUP, SIG_IGN);
249 #endif /* USE_VHANGUP */
250 fd = open(ttyname, O_RDWR);
252 error("%.100s: %.100s", ttyname, strerror(errno));
257 #else /* USE_VHANGUP */
259 #endif /* USE_VHANGUP */
261 /* Verify that we now have a controlling tty. */
262 fd = open("/dev/tty", O_WRONLY);
264 error("open /dev/tty failed - could not set controlling tty: %.100s",
271 /* Changes the window size associated with the pty. */
274 pty_change_window_size(int ptyfd, int row, int col,
275 int xpixel, int ypixel)
280 w.ws_xpixel = xpixel;
281 w.ws_ypixel = ypixel;
282 (void) ioctl(ptyfd, TIOCSWINSZ, &w);
286 pty_setowner(struct passwd *pw, const char *ttyname)
292 /* Determine the group to make the owner of the tty. */
293 grp = getgrnam("tty");
296 mode = S_IRUSR | S_IWUSR | S_IWGRP;
299 mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
302 /* Change ownership of the tty. */
303 if (chown(ttyname, pw->pw_uid, gid) < 0)
304 fatal("chown(%.100s, %d, %d) failed: %.100s",
305 ttyname, pw->pw_uid, gid, strerror(errno));
306 if (chmod(ttyname, mode) < 0)
307 fatal("chmod(%.100s, 0%o) failed: %.100s",
308 ttyname, mode, strerror(errno));