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Comparing rxvt-unicode/src/ptytty.C (file contents):
Revision 1.7 by pcg, Mon Mar 1 01:06:46 2004 UTC vs.
Revision 1.57 by root, Sun Jan 22 12:21:47 2006 UTC

1// This file is part of libptytty. Do not make local modifications.
2// http://software.schmorp.de/pkg/libptytty
3
1/*--------------------------------*-C-*---------------------------------* 4/*----------------------------------------------------------------------*
2 * File: ptytty.c 5 * File: ptytty.C
3 *----------------------------------------------------------------------* 6 *----------------------------------------------------------------------*
4 * 7 *
5 * All portions of code are copyright by their respective author/s. 8 * All portions of code are copyright by their respective author/s.
6 * Copyright (c) 1999-2001 Geoff Wing <gcw@pobox.com> 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>
7 * 12 *
8 * This program is free software; you can redistribute it and/or modify 13 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by 14 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or 15 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version. 16 * (at your option) any later version.
… …
18 * You should have received a copy of the GNU General Public License 23 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software 24 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 *---------------------------------------------------------------------*/ 26 *---------------------------------------------------------------------*/
22 27
23#include "../config.h" /* NECESSARY */ 28#include "../config.h"
24 29
25/* 30#include "ptytty.h"
26 * Try to be self-contained except for the above autoconfig'd defines
27 */
28 31
29#if 0
30#ifdef HAVE_GETPT
31# define _GNU_SOURCE
32#endif
33#endif
34
35#include <stdio.h>
36#ifdef HAVE_STDLIB_H
37# include <stdlib.h> 32#include <cstdlib>
38#endif 33#include <cstring>
39#ifdef HAVE_SYS_TYPES_H 34
40# include <sys/types.h> 35#include <sys/types.h>
41#endif 36#include <sys/socket.h>
42#ifdef HAVE_UNISTD_H
43# include <unistd.h> 37#include <unistd.h>
44#endif
45#if defined(HAVE_STRING_H)
46# include <string.h>
47#endif
48#ifdef HAVE_FCNTL_H
49# include <fcntl.h> 38#include <fcntl.h>
50#endif 39
51#ifdef HAVE_SYS_IOCTL_H 40#ifdef HAVE_SYS_IOCTL_H
52# include <sys/ioctl.h> 41# include <sys/ioctl.h>
53#endif 42#endif
54#if defined(PTYS_ARE_PTMX) && !defined(__CYGWIN32__) 43#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
55# include <sys/stropts.h> /* for I_PUSH */ 44# include <sys/stropts.h> /* for I_PUSH */
56#endif 45#endif
57 46#ifdef HAVE_ISASTREAM
58#ifdef DEBUG_TTY 47# include <stropts.h>
59# define D_TTY(x) fprintf x ; fputc('\n', stderr) ; fflush(stderr)
60#else
61# define D_TTY(x)
62#endif 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 63
64/* ------------------------------------------------------------------------- * 64/* ------------------------------------------------------------------------- *
65 * GET PSEUDO TELETYPE - MASTER AND SLAVE * 65 * GET PSEUDO TELETYPE - MASTER AND SLAVE *
66 * ------------------------------------------------------------------------- */ 66 * ------------------------------------------------------------------------- */
67/* 67/*
68 * Returns pty file descriptor, or -1 on failure 68 * Returns pty file descriptor, or -1 on failure
69 * If successful, ttydev is set to the name of the slave device. 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 70 * fd_tty _may_ also be set to an open fd to the slave device
71 */ 71 */
72/* EXTPROTO */ 72#if defined(UNIX98_PTY)
73int 73static int
74rxvt_get_pty (int *fd_tty, const char **ttydev) 74get_pty (int *fd_tty, char **ttydev)
75{ 75{
76 int pfd; 76 int pfd;
77 77
78#ifdef PTYS_ARE_OPENPTY 78# if defined(HAVE_GETPT)
79 pfd = getpt();
80# elif defined(HAVE_POSIX_OPENPT)
81 pfd = posix_openpt (O_RDWR);
82# else
83 pfd = open (CLONE_DEVICE, O_RDWR | O_NOCTTY, 0);
84# endif
85 if (pfd >= 0)
86 {
87 if (grantpt (pfd) == 0 /* change slave permissions */
88 && unlockpt (pfd) == 0)
89 { /* slave now unlocked */
90 *ttydev = strdup (ptsname (pfd)); /* get slave's name */
91 return pfd;
92 }
79 93
80 char tty_name[sizeof "/dev/pts/????\0"]; 94 close (pfd);
95 }
81 96
97 return -1;
98}
99#elif defined(HAVE_OPENPTY)
100static int
101get_pty (int *fd_tty, char **ttydev)
102{
103 int pfd;
104 int res;
105 char tty_name[32];
106
82 if (openpty (&pfd, fd_tty, tty_name, NULL, NULL) != -1) 107 res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);
108 if (res != -1)
83 { 109 {
84 *ttydev = strdup (tty_name); 110 *ttydev = strdup (tty_name);
85 return pfd; 111 return pfd;
86 } 112 }
87#endif
88 113
89#ifdef PTYS_ARE__GETPTY 114 return -1;
115}
116#elif defined(HAVE__GETPTY)
117static int
118get_pty (int *fd_tty, char **ttydev)
119{
120 int pfd;
121
90 *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0); 122 *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0);
91 if (*ttydev != NULL) 123 if (*ttydev != NULL)
92 return pfd; 124 return pfd;
93#endif
94 125
95#ifdef PTYS_ARE_GETPTY 126 return -1;
127}
128#elif defined(HAVE_DEV_PTC)
129static int
130get_pty (int *fd_tty, char **ttydev)
131{
132 int pfd;
96 133
97 char *ptydev;
98
99 while ((ptydev = getpty ()) != NULL)
100 if ((pfd = open (ptydev, O_RDWR | O_NOCTTY, 0)) >= 0)
101 {
102 *ttydev = ptydev;
103 return pfd;
104 }
105#endif
106
107#if defined(HAVE_GRANTPT) && defined(HAVE_UNLOCKPT)
108# if defined(PTYS_ARE_GETPT) || defined(PTYS_ARE_PTMX)
109
110 {
111# ifdef PTYS_ARE_GETPT
112 pfd = getpt ();
113# else
114
115 pfd = open ("/dev/ptmx", O_RDWR | O_NOCTTY, 0);
116# endif
117
118 if (pfd >= 0)
119 {
120 if (grantpt (pfd) == 0 /* change slave permissions */
121 && unlockpt (pfd) == 0)
122 { /* slave now unlocked */
123 *ttydev = ptsname (pfd); /* get slave's name */
124 return pfd;
125 }
126 close (pfd);
127 }
128 }
129# endif
130#endif
131
132#ifdef PTYS_ARE_PTC
133 if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0) 134 if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0)
134 { 135 {
135 *ttydev = ttyname (pfd); 136 *ttydev = strdup (ttyname (pfd));
136 return pfd; 137 return pfd;
137 } 138 }
138#endif
139 139
140#ifdef PTYS_ARE_CLONE 140 return -1;
141}
142#elif defined(HAVE_DEV_CLONE)
143static int
144get_pty (int *fd_tty, char **ttydev)
145{
146 int pfd;
147
141 if ((pfd = open ("/dev/ptym/clone", O_RDWR | O_NOCTTY, 0)) >= 0) 148 if ((pfd = open ("/dev/ptym/clone", O_RDWR | O_NOCTTY, 0)) >= 0)
142 { 149 {
143 *ttydev = ptsname (pfd); 150 *ttydev = strdup (ptsname (pfd));
144 return pfd; 151 return pfd;
145 } 152 }
146#endif
147 153
148#ifdef PTYS_ARE_NUMERIC
149 {
150 int idx;
151 char *c1, *c2;
152 char pty_name[] = "/dev/ptyp???";
153 char tty_name[] = "/dev/ttyp???";
154
155 c1 = & (pty_name[sizeof (pty_name) - 4]);
156 c2 = & (tty_name[sizeof (tty_name) - 4]);
157 for (idx = 0; idx < 256; idx++)
158 {
159 sprintf (c1, "%d", idx);
160 sprintf (c2, "%d", idx);
161 if (access (tty_name, F_OK) < 0)
162 {
163 idx = 256;
164 break;
165 }
166 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0)
167 {
168 if (access (tty_name, R_OK | W_OK) == 0)
169 {
170 *ttydev = strdup (tty_name);
171 return pfd;
172 }
173 close (pfd);
174 }
175 }
176 }
177#endif
178#ifdef PTYS_ARE_SEARCHED
179 {
180 const char *c1, *c2;
181 char pty_name[] = "/dev/pty??";
182 char tty_name[] = "/dev/tty??";
183
184# ifndef PTYCHAR1
185# define PTYCHAR1 "pqrstuvwxyz"
186# endif
187# ifndef PTYCHAR2
188# define PTYCHAR2 "0123456789abcdef"
189# endif
190
191 for (c1 = PTYCHAR1; *c1; c1++)
192 {
193 pty_name[ (sizeof (pty_name) - 3)] =
194 tty_name[ (sizeof (pty_name) - 3)] = *c1;
195 for (c2 = PTYCHAR2; *c2; c2++)
196 {
197 pty_name[ (sizeof (pty_name) - 2)] =
198 tty_name[ (sizeof (pty_name) - 2)] = *c2;
199 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0)
200 {
201 if (access (tty_name, R_OK | W_OK) == 0)
202 {
203 *ttydev = strdup (tty_name);
204 return pfd;
205 }
206 close (pfd);
207 }
208 }
209 }
210 }
211#endif
212 return -1; 154 return -1;
213} 155}
156#else
157/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
158static int
159get_pty (int *fd_tty, char **ttydev)
160{
161 int pfd;
162 int i;
163 char pty_name[32];
164 char tty_name[32];
165 const char *majors = "pqrstuvwxyzabcde";
166 const char *minors = "0123456789abcdef";
167 for (i = 0; i < 256; i++)
168 {
169 snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
170 snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
171 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) == -1)
172 {
173 snprintf(pty_name, 32, "/dev/ptyp%d", i);
174 snprintf(tty_name, 32, "/dev/ttyp%d", i);
175 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) == -1)
176 continue;
177 }
178 if (access (tty_name, R_OK | W_OK) == 0)
179 {
180 *ttydev = strdup (tty_name);
181 return pfd;
182 }
183
184 close (pfd);
185 }
186}
187#endif
214 188
215/*----------------------------------------------------------------------*/ 189/*----------------------------------------------------------------------*/
216/* 190/*
217 * Returns tty file descriptor, or -1 on failure 191 * Returns tty file descriptor, or -1 on failure
218 */ 192 */
219/* EXTPROTO */ 193static int
220int
221rxvt_get_tty (const char *ttydev) 194get_tty (char *ttydev)
222{ 195{
223 return open (ttydev, O_RDWR | O_NOCTTY, 0); 196 return open (ttydev, O_RDWR | O_NOCTTY, 0);
224} 197}
225 198
226/*----------------------------------------------------------------------*/ 199/*----------------------------------------------------------------------*/
227/* 200/*
228 * Make our tty a controlling tty so that /dev/tty points to us 201 * Make our tty a controlling tty so that /dev/tty points to us
229 */ 202 */
230/* EXTPROTO */ 203static int
231int 204control_tty (int fd_tty)
232rxvt_control_tty (int fd_tty, const char *ttydev)
233{ 205{
234#ifndef __QNX__
235 int fd;
236
237 D_TTY ((stderr, "rxvt_control_tty (): pid: %d, tty fd: %d, dev: %s", getpid (), fd_tty, ttydev));
238 /* ---------------------------------------- */
239# ifdef HAVE_SETSID
240 setsid (); 206 setsid ();
241# endif
242# if defined(HAVE_SETPGID)
243 setpgid (0, 0);
244# elif defined(HAVE_SETPGRP)
245 setpgrp (0, 0);
246# endif
247 /* ---------------------------------------- */
248# ifdef TIOCNOTTY
249 207
250 fd = open ("/dev/tty", O_RDWR | O_NOCTTY);
251 D_TTY ((stderr, "rxvt_control_tty (): Voiding tty associations: previous=%s", fd < 0 ? "no" : "yes"));
252 if (fd >= 0)
253 {
254 ioctl (fd, TIOCNOTTY, NULL); /* void tty associations */
255 close (fd);
256 }
257# endif
258 /* ---------------------------------------- */
259 fd = open ("/dev/tty", O_RDWR | O_NOCTTY);
260 D_TTY ((stderr, "rxvt_control_tty (): /dev/tty has controlling tty? %s", fd < 0 ? "no (good)" : "yes (bad)"));
261 if (fd >= 0)
262 close (fd); /* ouch: still have controlling tty */
263 /* ---------------------------------------- */
264#if defined(PTYS_ARE_PTMX) && defined(I_PUSH) 208#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
265 /* 209 /*
266 * Push STREAMS modules: 210 * Push STREAMS modules:
267 * ptem: pseudo-terminal hardware emulation module. 211 * ptem: pseudo-terminal hardware emulation module.
268 * ldterm: standard terminal line discipline. 212 * ldterm: standard terminal line discipline.
269 * ttcompat: V7, 4BSD and XENIX STREAMS compatibility module. 213 * ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
… …
281 */ 225 */
282# ifdef HAVE_ISASTREAM 226# ifdef HAVE_ISASTREAM
283 if (isastream (fd_tty) == 1) 227 if (isastream (fd_tty) == 1)
284# endif 228# endif
285 { 229 {
286 D_TTY ((stderr, "rxvt_control_tty (): Pushing STREAMS modules"));
287 ioctl (fd_tty, I_PUSH, "ptem"); 230 ioctl (fd_tty, I_PUSH, "ptem");
288 ioctl (fd_tty, I_PUSH, "ldterm"); 231 ioctl (fd_tty, I_PUSH, "ldterm");
289 ioctl (fd_tty, I_PUSH, "ttcompat"); 232 ioctl (fd_tty, I_PUSH, "ttcompat");
290 } 233 }
291#endif 234#endif
292 /* ---------------------------------------- */ 235
293# if defined(TIOCSCTTY)
294 fd = ioctl (fd_tty, TIOCSCTTY, NULL); 236 ioctl (fd_tty, TIOCSCTTY, NULL);
295 D_TTY ((stderr, "rxvt_control_tty (): ioctl (..,TIOCSCTTY): %d", fd)); 237
296# elif defined(TIOCSETCTTY) 238 int fd = open ("/dev/tty", O_WRONLY);
297 fd = ioctl (fd_tty, TIOCSETCTTY, NULL);
298 D_TTY ((stderr, "rxvt_control_tty (): ioctl (..,TIOCSETCTTY): %d", fd));
299# else
300 fd = open (ttydev, O_RDWR);
301 D_TTY ((stderr, "rxvt_control_tty (): tty open%s", fd < 0 ? " failure" : "ed OK"));
302 if (fd >= 0) 239 if (fd < 0)
240 return -1; /* fatal */
241
303 close (fd); 242 close (fd);
243
244 return 0;
245}
246
247void
248ptytty::close_tty ()
249{
250 if (tty < 0)
251 return;
252
253 close (tty);
254 tty = -1;
255}
256
257bool
258ptytty::make_controlling_tty ()
259{
260 return control_tty (tty) >= 0;
261}
262
263void
264ptytty::set_utf8_mode (bool on)
265{
266#ifdef IUTF8
267 if (pty < 0)
268 return;
269
270 struct termios tio;
271
272 if (tcgetattr (pty, &tio) != -1)
273 {
274 tcflag_t new_cflag = tio.c_iflag;
275
276 if (on)
277 new_cflag |= IUTF8;
278 else
279 new_cflag &= ~IUTF8;
280
281 if (new_cflag != tio.c_iflag)
282 {
283 tio.c_iflag = new_cflag;
284 tcsetattr (pty, TCSANOW, &tio);
285 }
286 }
287#endif
288}
289
290static struct ttyconf {
291 gid_t gid;
292 mode_t mode;
293
294 ttyconf ()
295 {
296#ifdef TTY_GID_SUPPORT
297 struct group *gr = getgrnam ("tty");
298
299 if (gr)
300 { /* change group ownership of tty to "tty" */
301 mode = S_IRUSR | S_IWUSR | S_IWGRP;
302 gid = gr->gr_gid;
303 }
304 else
305#endif /* TTY_GID_SUPPORT */
306 {
307 mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
308 gid = 0;
309 }
310 }
311} ttyconf;
312
313ptytty_unix::ptytty_unix ()
314{
315 name = 0;
316#if UTMP_SUPPORT
317 cmd_pid = 0;
318#endif
319}
320
321ptytty_unix::~ptytty_unix ()
322{
323#if UTMP_SUPPORT
324 logout ();
325#endif
326 put ();
327}
328
329void
330ptytty_unix::put ()
331{
332 chmod (name, RESTORE_TTY_MODE);
333 chown (name, 0, ttyconf.gid);
334
335 close_tty ();
336
337 if (pty >= 0)
338 close (pty);
339
340 free (name);
341
342 pty = tty = -1;
343 name = 0;
344}
345
346bool
347ptytty_unix::get ()
348{
349 /* get master (pty) */
350 if ((pty = get_pty (&tty, &name)) < 0)
351 return false;
352
353 fcntl (pty, F_SETFL, O_NONBLOCK);
354
355 /* get slave (tty) */
356 if (tty < 0)
357 {
358#ifndef NO_SETOWNER_TTYDEV
359 chown (name, getuid (), ttyconf.gid); /* fail silently */
360 chmod (name, ttyconf.mode);
361# ifdef HAVE_REVOKE
362 revoke (name);
304# endif 363# endif
305 /* ---------------------------------------- */ 364#endif
306 fd = open ("/dev/tty", O_WRONLY);
307 D_TTY ((stderr, "rxvt_control_tty (): do we have controlling tty now: %s", fd < 0 ? "no (fatal)" : "yes (good)"));
308 if (fd < 0)
309 return -1; /* fatal */
310 close (fd);
311 /* ---------------------------------------- */
312 D_TTY ((stderr, "rxvt_control_tty (): tcgetpgrp (): %d getpgrp (): %d", tcgetpgrp (fd_tty), getpgrp ()));
313 /* ---------------------------------------- */
314#endif /* ! __QNX__ */
315 365
366 if ((tty = get_tty (name)) < 0)
367 {
368 put ();
369 return false;
370 }
371 }
372
373 return true;
374}
375
376#if PTYTTY_HELPER
377
378static int sock_fd = -1;
379static int helper_pid, owner_pid;
380
381struct command
382{
383 enum { get, login, destroy } type;
384
385 ptytty *id;
386
387 bool login_shell;
388 int cmd_pid;
389 char hostname[512]; // arbitrary, but should be plenty
390};
391
392struct ptytty_proxy : ptytty
393{
394 ptytty *id;
395
396 ptytty_proxy ()
397 : id(0)
398 {
399 }
400
401 ~ptytty_proxy ();
402
403 bool get ();
404 void login (int cmd_pid, bool login_shell, const char *hostname);
405};
406
407bool
408ptytty_proxy::get ()
409{
410 command cmd;
411
412 cmd.type = command::get;
413
414 write (sock_fd, &cmd, sizeof (cmd));
415
416 if (read (sock_fd, &id, sizeof (id)) != sizeof (id))
417 ptytty_fatal ("protocol error while creating pty using helper process, aborting.\n");
418
419 if (!id)
420 return false;
421
422 if ((pty = recv_fd (sock_fd)) < 0
423 || (tty = recv_fd (sock_fd)) < 0)
424 ptytty_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n");
425
426 return true;
427}
428
429void
430ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname)
431{
432 command cmd;
433
434 cmd.type = command::login;
435 cmd.id = id;
436 cmd.cmd_pid = cmd_pid;
437 cmd.login_shell = login_shell;
438 strncpy (cmd.hostname, hostname, sizeof (cmd.hostname));
439
440 write (sock_fd, &cmd, sizeof (cmd));
441}
442
443ptytty_proxy::~ptytty_proxy ()
444{
445 if (id)
446 {
447 command cmd;
448
449 cmd.type = command::destroy;
450 cmd.id = id;
451
452 write (sock_fd, &cmd, sizeof (cmd));
453 }
454}
455
456static
457void serve ()
458{
459 command cmd;
460 vector<ptytty *> ptys;
461
462 while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command))
463 {
464 if (cmd.type == command::get)
465 {
466 // -> id ptyfd ttyfd
467 cmd.id = new ptytty_unix;
468
469 if (cmd.id->get ())
470 {
471 write (sock_fd, &cmd.id, sizeof (cmd.id));
472 ptys.push_back (cmd.id);
473
474 ptytty::send_fd (sock_fd, cmd.id->pty);
475 ptytty::send_fd (sock_fd, cmd.id->tty);
476 }
477 else
478 {
479 delete cmd.id;
480 cmd.id = 0;
481 write (sock_fd, &cmd.id, sizeof (cmd.id));
482 }
483 }
484 else if (cmd.type == command::login)
485 {
486#if UTMP_SUPPORT
487 if (find (ptys.begin (), ptys.end (), cmd.id))
488 {
489 cmd.hostname[sizeof (cmd.hostname) - 1] = 0;
490 cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname);
491 }
492#endif
493 }
494 else if (cmd.type == command::destroy)
495 {
496 vector<ptytty *>::iterator pty = find (ptys.begin (), ptys.end (), cmd.id);
497
498 if (pty != ptys.end ())
499 {
500 delete *pty;
501 ptys.erase (pty);
502 }
503 }
504 else
505 break;
506 }
507
508 // destroy all ptys
509 for (vector<ptytty *>::iterator i = ptys.end (); i-- > ptys.begin (); )
510 delete *i;
511}
512
513void
514ptytty::use_helper ()
515{
516 int pid = getpid ();
517
518 if (sock_fd >= 0 && pid == owner_pid)
316 return 0; 519 return;
520
521 owner_pid = pid;
522
523 int sv[2];
524
525 if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv))
526 ptytty_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");
527
528 helper_pid = fork ();
529
530 if (helper_pid < 0)
531 ptytty_fatal ("could not create pty/sessiondb helper process, aborting.\n");
532
533 if (helper_pid)
534 {
535 // client, process
536 sock_fd = sv[0];
537 close (sv[1]);
538 fcntl (sock_fd, F_SETFD, FD_CLOEXEC);
539 }
540 else
541 {
542 // server, pty-helper
543 sock_fd = sv[1];
544
545 chdir ("/");
546
547 for (int fd = 0; fd < 1023; fd++)
548 if (fd != sock_fd)
549 close (fd);
550
551 serve ();
552 _exit (EXIT_SUCCESS);
553 }
317} 554}
318/*----------------------- end-of-file (C source) -----------------------*/ 555
556#endif
557
558ptytty *
559ptytty::create ()
560{
561#if PTYTTY_HELPER
562 if (helper_pid && getpid () == owner_pid)
563 // use helper process
564 return new ptytty_proxy;
565 else
566#endif
567 return new ptytty_unix;
568}
569
570void
571ptytty::init ()
572{
573 uid_t uid = getuid ();
574 gid_t gid = getgid ();
575
576 // before doing anything else, check for setuid/setgid operation,
577 // start the helper process and drop privileges
578 if (uid != geteuid ()
579 || gid != getegid ())
580 {
581#if PTYTTY_HELPER
582 use_helper ();
583#else
584 ptytty_warn ("running setuid/setgid without pty helper compiled in, continuing unprivileged.\n");
585#endif
586
587 drop_privileges ();
588 }
589}
590
591void
592ptytty::drop_privileges ()
593{
594 uid_t uid = getuid ();
595 gid_t gid = getgid ();
596
597 // drop privileges
598#if HAVE_SETRESUID
599 setresgid (gid, gid, gid);
600 setresuid (uid, uid, uid);
601#elif HAVE_SETREUID
602 setregid (gid, gid);
603 setreuid (uid, uid);
604#elif HAVE_SETUID
605 setgid (gid);
606 setuid (uid);
607#endif
608
609 if (uid != geteuid ()
610 || gid != getegid ())
611 ptytty_fatal ("unable to drop privileges, aborting.\n");
612}
613

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