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/cvs/libptytty/src/ptytty.C
Revision: 1.29
Committed: Thu Jun 28 17:41:01 2007 UTC (17 years ago) by ayin
Content type: text/plain
Branch: MAIN
Changes since 1.28: +2 -3 lines
Log Message:
When using openpty, get the slave name with ttyname rather than with
the openpty broken interface.

File Contents

# Content
1 // This file is part of libptytty. Do not make local modifications.
2 // http://software.schmorp.de/pkg/libptytty
3
4 /*----------------------------------------------------------------------*
5 * File: ptytty.C
6 *----------------------------------------------------------------------*
7 *
8 * All portions of code are copyright by their respective author/s.
9 * Copyright (c) 1999-2001 Geoff Wing <gcw@pobox.com>
10 * Copyright (c) 2004-2006 Marc Lehmann <pcg@goof.com>
11 * Copyright (c) 2006 Emanuele Giaquinta <e.giaquinta@glauco.it>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 *---------------------------------------------------------------------*/
27
28 #include "../config.h"
29
30 #include "ptytty.h"
31
32 #include <cstdlib>
33 #include <cstring>
34 #include <csignal>
35
36 #include <sys/types.h>
37 #include <unistd.h>
38 #include <fcntl.h>
39
40 #ifdef HAVE_SYS_IOCTL_H
41 # include <sys/ioctl.h>
42 #endif
43 #if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
44 # include <sys/stropts.h> /* for I_PUSH */
45 #endif
46 #ifdef HAVE_ISASTREAM
47 # include <stropts.h>
48 #endif
49 #if defined(HAVE_PTY_H)
50 # include <pty.h>
51 #elif defined(HAVE_LIBUTIL_H)
52 # include <libutil.h>
53 #elif defined(HAVE_UTIL_H)
54 # include <util.h>
55 #endif
56 #ifdef TTY_GID_SUPPORT
57 #include <grp.h>
58 #endif
59
60 #include <cstdio>
61
62 /////////////////////////////////////////////////////////////////////////////
63
64 /* ------------------------------------------------------------------------- *
65 * GET PSEUDO TELETYPE - MASTER AND SLAVE *
66 * ------------------------------------------------------------------------- */
67 /*
68 * Returns pty file descriptor, or -1 on failure
69 * If successful, ttydev is set to the name of the slave device.
70 * fd_tty _may_ also be set to an open fd to the slave device
71 */
72 #if defined(UNIX98_PTY)
73
74 static int
75 get_pty (int *fd_tty, char **ttydev)
76 {
77 int pfd;
78
79 # if defined(HAVE_GETPT)
80 pfd = getpt();
81 # elif defined(HAVE_POSIX_OPENPT)
82 pfd = posix_openpt (O_RDWR);
83 # else
84 pfd = open (CLONE_DEVICE, O_RDWR | O_NOCTTY, 0);
85 # endif
86
87 if (pfd >= 0)
88 {
89 if (grantpt (pfd) == 0 /* change slave permissions */
90 && unlockpt (pfd) == 0)
91 { /* slave now unlocked */
92 *ttydev = strdup (ptsname (pfd)); /* get slave's name */
93 return pfd;
94 }
95
96 close (pfd);
97 }
98
99 return -1;
100 }
101
102 #elif defined(HAVE_OPENPTY)
103
104 static int
105 get_pty (int *fd_tty, char **ttydev)
106 {
107 int pfd;
108 int res;
109
110 res = openpty (&pfd, fd_tty, NULL, NULL, NULL);
111
112 if (res != -1)
113 {
114 *ttydev = strdup (ttyname (*fd_tty));
115 return pfd;
116 }
117
118 return -1;
119 }
120
121 #elif defined(HAVE__GETPTY)
122
123 static int
124 get_pty (int *fd_tty, char **ttydev)
125 {
126 int pfd;
127
128 *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0);
129
130 if (*ttydev != NULL)
131 return pfd;
132
133 return -1;
134 }
135
136 #elif defined(HAVE_DEV_PTC)
137
138 static int
139 get_pty (int *fd_tty, char **ttydev)
140 {
141 int pfd;
142
143 if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0)
144 {
145 *ttydev = strdup (ttyname (pfd));
146 return pfd;
147 }
148
149 return -1;
150 }
151
152 #elif defined(HAVE_DEV_CLONE)
153
154 static int
155 get_pty (int *fd_tty, char **ttydev)
156 {
157 int pfd;
158
159 if ((pfd = open ("/dev/ptym/clone", O_RDWR | O_NOCTTY, 0)) >= 0)
160 {
161 *ttydev = strdup (ptsname (pfd));
162 return pfd;
163 }
164
165 return -1;
166 }
167
168 #else
169
170 /* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
171 static int
172 get_pty (int *fd_tty, char **ttydev)
173 {
174 int pfd;
175 int i;
176 char pty_name[32];
177 char tty_name[32];
178 const char *majors = "pqrstuvwxyzabcde";
179 const char *minors = "0123456789abcdef";
180
181 for (i = 0; i < 256; i++)
182 {
183 snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
184 snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
185
186 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) == -1)
187 {
188 snprintf(pty_name, 32, "/dev/ptyp%d", i);
189 snprintf(tty_name, 32, "/dev/ttyp%d", i);
190 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) == -1)
191 continue;
192 }
193
194 if (access (tty_name, R_OK | W_OK) == 0)
195 {
196 *ttydev = strdup (tty_name);
197 return pfd;
198 }
199
200 close (pfd);
201 }
202
203 return -1;
204 }
205
206 #endif
207
208 /*----------------------------------------------------------------------*/
209 /*
210 * Returns tty file descriptor, or -1 on failure
211 */
212 static int
213 get_tty (char *ttydev)
214 {
215 return open (ttydev, O_RDWR | O_NOCTTY, 0);
216 }
217
218 /*----------------------------------------------------------------------*/
219 /*
220 * Make our tty a controlling tty so that /dev/tty points to us
221 */
222 static int
223 control_tty (int fd_tty)
224 {
225 int fd;
226
227 setsid ();
228
229 #if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
230 /*
231 * Push STREAMS modules:
232 * ptem: pseudo-terminal hardware emulation module.
233 * ldterm: standard terminal line discipline.
234 * ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
235 *
236 * After we push the STREAMS modules, the first open () on the slave side
237 * (i.e. the next section between the dashes giving us "tty opened OK")
238 * should make the "ptem" (or "ldterm" depending upon either which OS
239 * version or which set of manual pages you have) module give us a
240 * controlling terminal. We must already have close ()d the master side
241 * fd in this child process before we push STREAMS modules on because the
242 * documentation is really unclear about whether it is any close () on
243 * the master side or the last close () - i.e. a proper STREAMS dismantling
244 * close () - on the master side which causes a hang up to be sent
245 * through - Geoff Wing
246 */
247 # ifdef HAVE_ISASTREAM
248 if (isastream (fd_tty) == 1)
249 # endif
250 {
251 ioctl (fd_tty, I_PUSH, "ptem");
252 ioctl (fd_tty, I_PUSH, "ldterm");
253 ioctl (fd_tty, I_PUSH, "ttcompat");
254 }
255 #endif
256
257 #ifdef TIOCSCTTY
258 ioctl (fd_tty, TIOCSCTTY, NULL);
259 #else
260 fd = open (ttyname (fd_tty), O_RDWR);
261 if (fd >= 0)
262 close (fd);
263 #endif
264
265 fd = open ("/dev/tty", O_WRONLY);
266 if (fd < 0)
267 return -1; /* fatal */
268
269 close (fd);
270
271 return 0;
272 }
273
274 void
275 ptytty::close_tty ()
276 {
277 if (tty < 0)
278 return;
279
280 close (tty);
281 tty = -1;
282 }
283
284 bool
285 ptytty::make_controlling_tty ()
286 {
287 return control_tty (tty) >= 0;
288 }
289
290 void
291 ptytty::set_utf8_mode (bool on)
292 {
293 #ifdef IUTF8
294 if (pty < 0)
295 return;
296
297 struct termios tio;
298
299 if (tcgetattr (pty, &tio) != -1)
300 {
301 tcflag_t new_cflag = tio.c_iflag;
302
303 if (on)
304 new_cflag |= IUTF8;
305 else
306 new_cflag &= ~IUTF8;
307
308 if (new_cflag != tio.c_iflag)
309 {
310 tio.c_iflag = new_cflag;
311 tcsetattr (pty, TCSANOW, &tio);
312 }
313 }
314 #endif
315 }
316
317 static struct ttyconf {
318 gid_t gid;
319 mode_t mode;
320
321 ttyconf ()
322 {
323 #ifdef TTY_GID_SUPPORT
324 struct group *gr = getgrnam ("tty");
325
326 if (gr)
327 { /* change group ownership of tty to "tty" */
328 mode = S_IRUSR | S_IWUSR | S_IWGRP;
329 gid = gr->gr_gid;
330 }
331 else
332 #endif /* TTY_GID_SUPPORT */
333 {
334 mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
335 gid = 0;
336 }
337 }
338 } ttyconf;
339
340 ptytty_unix::ptytty_unix ()
341 {
342 name = 0;
343 #if UTMP_SUPPORT
344 cmd_pid = 0;
345 #endif
346 }
347
348 ptytty_unix::~ptytty_unix ()
349 {
350 #if UTMP_SUPPORT
351 logout ();
352 #endif
353 put ();
354 }
355
356 void
357 ptytty_unix::put ()
358 {
359 if (name)
360 {
361 chmod (name, RESTORE_TTY_MODE);
362 chown (name, 0, ttyconf.gid);
363 }
364
365 close_tty ();
366
367 if (pty >= 0)
368 close (pty);
369
370 free (name);
371
372 pty = tty = -1;
373 name = 0;
374 }
375
376 bool
377 ptytty_unix::get ()
378 {
379 /* get master (pty) */
380 if ((pty = get_pty (&tty, &name)) < 0)
381 return false;
382
383 fcntl (pty, F_SETFL, O_NONBLOCK);
384
385 /* get slave (tty) */
386 if (tty < 0)
387 {
388 #ifndef NO_SETOWNER_TTYDEV
389 chown (name, getuid (), ttyconf.gid); /* fail silently */
390 chmod (name, ttyconf.mode);
391 # ifdef HAVE_REVOKE
392 revoke (name);
393 # endif
394 #endif
395
396 if ((tty = get_tty (name)) < 0)
397 {
398 put ();
399 return false;
400 }
401 }
402
403 return true;
404 }
405