]> andersk Git - openssh.git/blame - sshpty.c
- jakob@cvs.openbsd.org 2001/12/18 10:06:24
[openssh.git] / sshpty.c
CommitLineData
8efc0c15 1/*
5260325f 2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
5260325f 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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
14#include "includes.h"
4f7893dc 15RCSID("$OpenBSD: sshpty.c,v 1.3 2001/07/22 21:32:27 markus Exp $");
8efc0c15 16
884bcb37 17#ifdef HAVE_UTIL_H
18# include <util.h>
19#endif /* HAVE_UTIL_H */
20
1729c161 21#include "sshpty.h"
42f11eb2 22#include "log.h"
5ad9f968 23#include "misc.h"
5260325f 24
8efc0c15 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
6d8c4ea4 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
8efc0c15 37#ifndef O_NOCTTY
38#define O_NOCTTY 0
39#endif
40
aa3378df 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 */
8efc0c15 47
6ae2364d 48int
a408af76 49pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, int namebuflen)
8efc0c15 50{
a408af76 51#if defined(HAVE_OPENPTY) || defined(BSD4_4)
5260325f 52 /* openpty(3) exists in OSF/1 and some other os'es */
b82f1310 53 char *name;
5260325f 54 int i;
8efc0c15 55
b82f1310 56 i = openpty(ptyfd, ttyfd, NULL, NULL, NULL);
5260325f 57 if (i < 0) {
58 error("openpty: %.100s", strerror(errno));
59 return 0;
60 }
b82f1310 61 name = ttyname(*ttyfd);
62 if (!name)
63 fatal("openpty returns device for which ttyname fails.");
64
65 strlcpy(namebuf, name, namebuflen); /* possible truncation */
5260325f 66 return 1;
8efc0c15 67#else /* HAVE_OPENPTY */
68#ifdef HAVE__GETPTY
aa3378df 69 /*
70 * _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
71 * pty's automagically when needed
72 */
5260325f 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 }
a408af76 80 strlcpy(namebuf, slave, namebuflen);
5260325f 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;
8efc0c15 89#else /* HAVE__GETPTY */
a7effaac 90#if defined(HAVE_DEV_PTMX)
aa3378df 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 */
5260325f 95 int ptm;
96 char *pts;
5ad9f968 97 mysig_t old_signal;
5260325f 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 }
5ad9f968 104 old_signal = mysignal(SIGCHLD, SIG_DFL);
5260325f 105 if (grantpt(ptm) < 0) {
106 error("grantpt: %.100s", strerror(errno));
107 return 0;
108 }
5ad9f968 109 mysignal(SIGCHLD, old_signal);
5260325f 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.");
a408af76 117 strlcpy(namebuf, pts, namebuflen);
5260325f 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 }
3c62e7eb 127#ifndef HAVE_CYGWIN
96054e6f 128 /*
129 * Push the appropriate streams modules, as described in Solaris pts(7).
130 * HP-UX pts(7) doesn't have ttcompat module.
131 */
5260325f 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));
96054e6f 136#ifndef __hpux
5260325f 137 if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
138 error("ioctl I_PUSH ttcompat: %.100s", strerror(errno));
3c62e7eb 139#endif
be48d23c 140#endif
5260325f 141 return 1;
8efc0c15 142#else /* HAVE_DEV_PTMX */
143#ifdef HAVE_DEV_PTS_AND_PTC
5260325f 144 /* AIX-style pty code. */
145 const char *name;
8efc0c15 146
5260325f 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.");
a408af76 155 strlcpy(namebuf, name, namebuflen);
5260325f 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;
8efc0c15 164#else /* HAVE_DEV_PTS_AND_PTC */
1a23ac2c 165#ifdef _CRAY
166 char buf[64];
167 int i;
168 int highpty;
169
170#ifdef _SC_CRAY_NPTY
68187931 171 highpty = sysconf(_SC_CRAY_NPTY);
172 if (highpty == -1)
173 highpty = 128;
1a23ac2c 174#else
68187931 175 highpty = 128;
1a23ac2c 176#endif
177
68187931 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) {
1a23ac2c 187 error("%.100s: %.100s", namebuf, strerror(errno));
68187931 188 close(*ptyfd);
5bd6962b 189 return 0;
68187931 190 }
191 return 1;
192 }
193 return 0;
1a23ac2c 194#else
5260325f 195 /* BSD-style pty code. */
196 char buf[64];
197 int i;
aa3378df 198 const char *ptymajors = "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ";
5260325f 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]);
95f1eccc 206 snprintf(namebuf, namebuflen, "/dev/tty%c%c",
a408af76 207 ptymajors[i / num_minors], ptyminors[i % num_minors]);
5260325f 208
b5f90139 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;
2b87da3b 217 }
218
5260325f 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;
8efc0c15 227 }
5260325f 228 return 0;
1a23ac2c 229#endif /* CRAY */
8efc0c15 230#endif /* HAVE_DEV_PTS_AND_PTC */
231#endif /* HAVE_DEV_PTMX */
232#endif /* HAVE__GETPTY */
233#endif /* HAVE_OPENPTY */
234}
235
5260325f 236/* Releases the tty. Its ownership is returned to root, and permissions to 0666. */
8efc0c15 237
6ae2364d 238void
5260325f 239pty_release(const char *ttyname)
8efc0c15 240{
3276571c 241 if (chown(ttyname, (uid_t) 0, (gid_t) 0) < 0)
817175bc 242 error("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
3276571c 243 if (chmod(ttyname, (mode_t) 0666) < 0)
817175bc 244 error("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno));
8efc0c15 245}
246
247/* Makes the tty the processes controlling tty and sets it to sane modes. */
248
6ae2364d 249void
5260325f 250pty_make_controlling_tty(int *ttyfd, const char *ttyname)
8efc0c15 251{
1a23ac2c 252 int fd;
8140f2aa 253#ifdef USE_VHANGUP
254 void *old;
255#endif /* USE_VHANGUP */
1a23ac2c 256
8140f2aa 257#ifdef _CRAY
68187931 258 if (setsid() < 0)
259 error("setsid: %.100s", strerror(errno));
1a23ac2c 260
68187931 261 fd = open(ttyname, O_RDWR|O_NOCTTY);
262 if (fd != -1) {
8140f2aa 263 mysignal(SIGHUP, SIG_IGN);
68187931 264 ioctl(fd, TCVHUP, (char *)NULL);
8140f2aa 265 mysignal(SIGHUP, SIG_DFL);
68187931 266 setpgid(0, 0);
267 close(fd);
1a23ac2c 268 } else {
68187931 269 error("Failed to disconnect from controlling tty.");
1a23ac2c 270 }
1a23ac2c 271
68187931 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));
1a23ac2c 277 close(*ttyfd);
278 *ttyfd = fd;
8140f2aa 279#else /* _CRAY */
8efc0c15 280
5260325f 281 /* First disconnect from the old controlling tty. */
8efc0c15 282#ifdef TIOCNOTTY
5ca51e19 283 fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
5260325f 284 if (fd >= 0) {
285 (void) ioctl(fd, TIOCNOTTY, NULL);
286 close(fd);
287 }
8efc0c15 288#endif /* TIOCNOTTY */
5260325f 289 if (setsid() < 0)
290 error("setsid: %.100s", strerror(errno));
291
aa3378df 292 /*
293 * Verify that we are successfully disconnected from the controlling
294 * tty.
295 */
5ca51e19 296 fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
5260325f 297 if (fd >= 0) {
298 error("Failed to disconnect from controlling tty.");
299 close(fd);
300 }
301 /* Make it our controlling tty. */
8efc0c15 302#ifdef TIOCSCTTY
5260325f 303 debug("Setting controlling tty using TIOCSCTTY.");
a3bf38d0 304 if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0)
305 error("ioctl(TIOCSCTTY): %.100s", strerror(errno));
8efc0c15 306#endif /* TIOCSCTTY */
66d6c27e 307#ifdef HAVE_NEWS4
308 if (setpgrp(0,0) < 0)
309 error("SETPGRP %s",strerror(errno));
310#endif /* HAVE_NEWS4 */
3c62e7eb 311#ifdef USE_VHANGUP
8140f2aa 312 old = mysignal(SIGHUP, SIG_IGN);
4e577b89 313 vhangup();
8140f2aa 314 mysignal(SIGHUP, old);
3c62e7eb 315#endif /* USE_VHANGUP */
5260325f 316 fd = open(ttyname, O_RDWR);
4e577b89 317 if (fd < 0) {
5260325f 318 error("%.100s: %.100s", ttyname, strerror(errno));
4e577b89 319 } else {
3c62e7eb 320#ifdef USE_VHANGUP
4e577b89 321 close(*ttyfd);
322 *ttyfd = fd;
3c62e7eb 323#else /* USE_VHANGUP */
5260325f 324 close(fd);
3c62e7eb 325#endif /* USE_VHANGUP */
4e577b89 326 }
5260325f 327 /* Verify that we now have a controlling tty. */
5ca51e19 328 fd = open(_PATH_TTY, O_WRONLY);
5260325f 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 }
8140f2aa 335#endif /* _CRAY */
8efc0c15 336}
337
338/* Changes the window size associated with the pty. */
339
6ae2364d 340void
5260325f 341pty_change_window_size(int ptyfd, int row, int col,
342 int xpixel, int ypixel)
8efc0c15 343{
5260325f 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);
8efc0c15 350}
817175bc 351
352void
353pty_setowner(struct passwd *pw, const char *ttyname)
354{
355 struct group *grp;
356 gid_t gid;
357 mode_t mode;
227e8e86 358 struct stat st;
817175bc 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
227e8e86 370 /*
371 * Change owner and mode of the tty as required.
4f7893dc 372 * Warn but continue if filesystem is read-only and the uids match/
373 * tty is owned by root.
227e8e86 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) {
7458aff1 381 if (errno == EROFS &&
382 (st.st_uid == pw->pw_uid || st.st_uid == 0))
227e8e86 383 error("chown(%.100s, %d, %d) failed: %.100s",
2b87da3b 384 ttyname, pw->pw_uid, gid,
227e8e86 385 strerror(errno));
386 else
387 fatal("chown(%.100s, %d, %d) failed: %.100s",
2b87da3b 388 ttyname, pw->pw_uid, gid,
227e8e86 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 }
817175bc 404}
This page took 0.200229 seconds and 5 git commands to generate.