5 * Author: Tatu Ylonen <ylo@cs.hut.fi>
7 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
10 * Created: Fri Mar 17 04:37:25 1995 ylo
12 * Allocating a pseudo-terminal, and making it the controlling tty.
17 RCSID("$OpenBSD: pty.c,v 1.14 2000/06/20 01:39:43 markus Exp $");
21 #endif /* HAVE_UTIL_H */
26 /* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */
27 #if defined(HAVE__GETPTY) || defined(HAVE_OPENPTY)
34 #if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
35 # include <sys/stropts.h>
43 * Allocates and opens a pty. Returns 0 if no pty could be allocated, or
44 * nonzero if a pty was successfully allocated. On success, open file
45 * descriptors for the pty and tty sides and the name of the tty side are
46 * returned (the buffer must be able to hold at least 64 characters).
50 pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen)
52 #if defined(HAVE_OPENPTY) || defined(BSD4_4)
53 /* openpty(3) exists in OSF/1 and some other os'es */
57 i = openpty(ptyfd, ttyfd, buf, NULL, NULL);
59 error("openpty: %.100s", strerror(errno));
62 strlcpy(namebuf, buf, namebuflen); /* possible truncation */
64 #else /* HAVE_OPENPTY */
67 * _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
68 * pty's automagically when needed
72 slave = _getpty(ptyfd, O_RDWR, 0622, 0);
74 error("_getpty: %.100s", strerror(errno));
77 strlcpy(namebuf, slave, namebuflen);
78 /* Open the slave side. */
79 *ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
81 error("%.200s: %.100s", namebuf, strerror(errno));
86 #else /* HAVE__GETPTY */
87 #if defined(HAVE_DEV_PTMX)
89 * This code is used e.g. on Solaris 2.x. (Note that Solaris 2.3
90 * also has bsd-style ptys, but they simply do not work.)
95 ptm = open("/dev/ptmx", O_RDWR | O_NOCTTY);
97 error("/dev/ptmx: %.100s", strerror(errno));
100 if (grantpt(ptm) < 0) {
101 error("grantpt: %.100s", strerror(errno));
104 if (unlockpt(ptm) < 0) {
105 error("unlockpt: %.100s", strerror(errno));
110 error("Slave pty side name could not be obtained.");
111 strlcpy(namebuf, pts, namebuflen);
114 /* Open the slave side. */
115 *ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
117 error("%.100s: %.100s", namebuf, strerror(errno));
121 /* Push the appropriate streams modules, as described in Solaris pts(7). */
122 if (ioctl(*ttyfd, I_PUSH, "ptem") < 0)
123 error("ioctl I_PUSH ptem: %.100s", strerror(errno));
124 if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0)
125 error("ioctl I_PUSH ldterm: %.100s", strerror(errno));
127 if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
128 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 *ptyfd = open(buf, O_RDWR | O_NOCTTY);
168 snprintf(namebuf, namebuflen, "/dev/tty%c%c",
169 ptymajors[i / num_minors], ptyminors[i % num_minors]);
171 /* Open the slave side. */
172 *ttyfd = open(namebuf, O_RDWR | O_NOCTTY);
174 error("%.100s: %.100s", namebuf, strerror(errno));
181 #endif /* HAVE_DEV_PTS_AND_PTC */
182 #endif /* HAVE_DEV_PTMX */
183 #endif /* HAVE__GETPTY */
184 #endif /* HAVE_OPENPTY */
187 /* Releases the tty. Its ownership is returned to root, and permissions to 0666. */
190 pty_release(const char *ttyname)
192 if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0)
193 error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
194 if (chmod(ttyname, (mode_t) 0666) < 0)
195 error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno));
198 /* Makes the tty the processes controlling tty and sets it to sane modes. */
201 pty_make_controlling_tty(int *ttyfd, const char *ttyname)
206 #endif /* HAVE_VHANGUP */
208 /* First disconnect from the old controlling tty. */
210 fd = open("/dev/tty", O_RDWR | O_NOCTTY);
212 (void) ioctl(fd, TIOCNOTTY, NULL);
215 #endif /* TIOCNOTTY */
217 error("setsid: %.100s", strerror(errno));
220 * Verify that we are successfully disconnected from the controlling
223 fd = open("/dev/tty", O_RDWR | O_NOCTTY);
225 error("Failed to disconnect from controlling tty.");
228 /* Make it our controlling tty. */
230 debug("Setting controlling tty using TIOCSCTTY.");
232 * We ignore errors from this, because HPSUX defines TIOCSCTTY, but
233 * returns EINVAL with these arguments, and there is absolutely no
236 ioctl(*ttyfd, TIOCSCTTY, NULL);
237 #endif /* TIOCSCTTY */
239 old = signal(SIGHUP, SIG_IGN);
242 #endif /* HAVE_VHANGUP */
243 fd = open(ttyname, O_RDWR);
245 error("%.100s: %.100s", ttyname, strerror(errno));
250 #else /* HAVE_VHANGUP */
252 #endif /* HAVE_VHANGUP */
254 /* Verify that we now have a controlling tty. */
255 fd = open("/dev/tty", O_WRONLY);
257 error("open /dev/tty failed - could not set controlling tty: %.100s",
264 /* Changes the window size associated with the pty. */
267 pty_change_window_size(int ptyfd, int row, int col,
268 int xpixel, int ypixel)
273 w.ws_xpixel = xpixel;
274 w.ws_ypixel = ypixel;
275 (void) ioctl(ptyfd, TIOCSWINSZ, &w);
279 pty_setowner(struct passwd *pw, const char *ttyname)
285 /* Determine the group to make the owner of the tty. */
286 grp = getgrnam("tty");
289 mode = S_IRUSR | S_IWUSR | S_IWGRP;
292 mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
295 /* Change ownership of the tty. */
296 if (chown(ttyname, pw->pw_uid, gid) < 0)
297 fatal("chown(%.100s, %d, %d) failed: %.100s",
298 ttyname, pw->pw_uid, gid, strerror(errno));
299 if (chmod(ttyname, mode) < 0)
300 fatal("chmod(%.100s, 0%o) failed: %.100s",
301 ttyname, mode, strerror(errno));