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Comparing rxvt-unicode/src/ptytty.C (file contents):
Revision 1.11 by pcg, Thu Apr 8 20:31:45 2004 UTC vs.
Revision 1.56 by root, Sun Jan 22 04:01:52 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>
7 * Copyright (c) 2004 Marc Lehmann <pcg@goof.com> 10 * Copyright (c) 2004-2006 Marc Lehmann <pcg@goof.com>
8 * 11 *
9 * This program is free software; you can redistribute it and/or modify 12 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by 13 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or 14 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version. 15 * (at your option) any later version.
… …
19 * You should have received a copy of the GNU General Public License 22 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software 23 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 *---------------------------------------------------------------------*/ 25 *---------------------------------------------------------------------*/
23 26
24#include "../config.h" /* NECESSARY */ 27#include "../config.h"
25 28
26/* 29#include "ptytty.h"
27 * Try to be self-contained except for the above autoconfig'd defines
28 */
29 30
30#if 0
31#ifdef HAVE_GETPT
32# define _GNU_SOURCE
33#endif
34#endif
35
36#include <cstdio>
37#ifdef HAVE_STDLIB_H
38# include <cstdlib> 31#include <cstdlib>
39#endif 32#include <cstring>
40#ifdef HAVE_SYS_TYPES_H 33
41# include <sys/types.h> 34#include <sys/types.h>
42#endif 35#include <sys/socket.h>
43#ifdef HAVE_UNISTD_H
44# include <unistd.h> 36#include <unistd.h>
45#endif
46#if defined(HAVE_STRING_H)
47# include <cstring>
48#endif
49#ifdef HAVE_FCNTL_H
50# include <fcntl.h> 37#include <fcntl.h>
51#endif 38
52#ifdef HAVE_SYS_IOCTL_H 39#ifdef HAVE_SYS_IOCTL_H
53# include <sys/ioctl.h> 40# include <sys/ioctl.h>
54#endif 41#endif
55#if defined(PTYS_ARE_PTMX) && !defined(__CYGWIN32__) 42#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
56# include <sys/stropts.h> /* for I_PUSH */ 43# include <sys/stropts.h> /* for I_PUSH */
57#endif 44#endif
58#ifdef HAVE_ISASTREAM 45#ifdef HAVE_ISASTREAM
59# include <stropts.h> 46# include <stropts.h>
60#endif 47#endif
61 48#if defined(HAVE_PTY_H)
62#ifdef DEBUG_TTY 49# include <pty.h>
63# define D_TTY(x) fprintf x ; fputc('\n', stderr) ; fflush(stderr) 50#elif defined(HAVE_LIBUTIL_H)
64#else 51# include <libutil.h>
65# define D_TTY(x) 52#elif defined(HAVE_UTIL_H)
53# include <util.h>
66#endif 54#endif
55#ifdef TTY_GID_SUPPORT
56#include <grp.h>
57#endif
58
59#include <cstdio>
60
61/////////////////////////////////////////////////////////////////////////////
67 62
68/* ------------------------------------------------------------------------- * 63/* ------------------------------------------------------------------------- *
69 * GET PSEUDO TELETYPE - MASTER AND SLAVE * 64 * GET PSEUDO TELETYPE - MASTER AND SLAVE *
70 * ------------------------------------------------------------------------- */ 65 * ------------------------------------------------------------------------- */
71/* 66/*
72 * Returns pty file descriptor, or -1 on failure 67 * Returns pty file descriptor, or -1 on failure
73 * If successful, ttydev is set to the name of the slave device. 68 * If successful, ttydev is set to the name of the slave device.
74 * fd_tty _may_ also be set to an open fd to the slave device 69 * fd_tty _may_ also be set to an open fd to the slave device
75 */ 70 */
76/* EXTPROTO */ 71#if defined(UNIX98_PTY)
77int 72static int
78rxvt_get_pty (int *fd_tty, const char **ttydev) 73get_pty (int *fd_tty, char **ttydev)
79{ 74{
80 int pfd; 75 int pfd;
81 76
82#ifdef PTYS_ARE_OPENPTY 77# if defined(HAVE_GETPT)
78 pfd = getpt();
79# elif defined(HAVE_POSIX_OPENPT)
80 pfd = posix_openpt (O_RDWR);
81# else
82 pfd = open (CLONE_DEVICE, O_RDWR | O_NOCTTY, 0);
83# endif
84 if (pfd >= 0)
85 {
86 if (grantpt (pfd) == 0 /* change slave permissions */
87 && unlockpt (pfd) == 0)
88 { /* slave now unlocked */
89 *ttydev = strdup (ptsname (pfd)); /* get slave's name */
90 return pfd;
91 }
83 92
84 char tty_name[sizeof "/dev/pts/????\0"]; 93 close (pfd);
94 }
85 95
96 return -1;
97}
98#elif defined(HAVE_OPENPTY)
99static int
100get_pty (int *fd_tty, char **ttydev)
101{
102 int pfd;
103 int res;
104 char tty_name[32];
105
86 if (openpty (&pfd, fd_tty, tty_name, NULL, NULL) != -1) 106 res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);
107 if (res != -1)
87 { 108 {
88 *ttydev = strdup (tty_name); 109 *ttydev = strdup (tty_name);
89 return pfd; 110 return pfd;
90 } 111 }
91#endif
92 112
93#ifdef PTYS_ARE__GETPTY 113 return -1;
114}
115#elif defined(HAVE__GETPTY)
116static int
117get_pty (int *fd_tty, char **ttydev)
118{
119 int pfd;
120
94 *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0); 121 *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0);
95 if (*ttydev != NULL) 122 if (*ttydev != NULL)
96 return pfd; 123 return pfd;
97#endif
98 124
99#ifdef PTYS_ARE_GETPTY 125 return -1;
126}
127#elif defined(HAVE_DEV_PTC)
128static int
129get_pty (int *fd_tty, char **ttydev)
130{
131 int pfd;
100 132
101 char *ptydev;
102
103 while ((ptydev = getpty ()) != NULL)
104 if ((pfd = open (ptydev, O_RDWR | O_NOCTTY, 0)) >= 0)
105 {
106 *ttydev = ptydev;
107 return pfd;
108 }
109#endif
110
111#if defined(HAVE_GRANTPT) && defined(HAVE_UNLOCKPT)
112# if defined(PTYS_ARE_GETPT) || defined(PTYS_ARE_PTMX)
113
114 {
115# ifdef PTYS_ARE_GETPT
116 pfd = getpt ();
117# else
118
119 pfd = open ("/dev/ptmx", O_RDWR | O_NOCTTY, 0);
120# endif
121
122 if (pfd >= 0)
123 {
124 if (grantpt (pfd) == 0 /* change slave permissions */
125 && unlockpt (pfd) == 0)
126 { /* slave now unlocked */
127 *ttydev = ptsname (pfd); /* get slave's name */
128 return pfd;
129 }
130 close (pfd);
131 }
132 }
133# endif
134#endif
135
136#ifdef PTYS_ARE_PTC
137 if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0) 133 if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0)
138 { 134 {
139 *ttydev = ttyname (pfd); 135 *ttydev = strdup (ttyname (pfd));
140 return pfd; 136 return pfd;
141 } 137 }
142#endif
143 138
144#ifdef PTYS_ARE_CLONE 139 return -1;
140}
141#elif defined(HAVE_DEV_CLONE)
142static int
143get_pty (int *fd_tty, char **ttydev)
144{
145 int pfd;
146
145 if ((pfd = open ("/dev/ptym/clone", O_RDWR | O_NOCTTY, 0)) >= 0) 147 if ((pfd = open ("/dev/ptym/clone", O_RDWR | O_NOCTTY, 0)) >= 0)
146 { 148 {
147 *ttydev = ptsname (pfd); 149 *ttydev = strdup (ptsname (pfd));
148 return pfd; 150 return pfd;
149 } 151 }
150#endif
151 152
152#ifdef PTYS_ARE_NUMERIC
153 {
154 int idx;
155 char *c1, *c2;
156 char pty_name[] = "/dev/ptyp???";
157 char tty_name[] = "/dev/ttyp???";
158
159 c1 = & (pty_name[sizeof (pty_name) - 4]);
160 c2 = & (tty_name[sizeof (tty_name) - 4]);
161 for (idx = 0; idx < 256; idx++)
162 {
163 sprintf (c1, "%d", idx);
164 sprintf (c2, "%d", idx);
165 if (access (tty_name, F_OK) < 0)
166 {
167 idx = 256;
168 break;
169 }
170 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0)
171 {
172 if (access (tty_name, R_OK | W_OK) == 0)
173 {
174 *ttydev = strdup (tty_name);
175 return pfd;
176 }
177 close (pfd);
178 }
179 }
180 }
181#endif
182#ifdef PTYS_ARE_SEARCHED
183 {
184 const char *c1, *c2;
185 char pty_name[] = "/dev/pty??";
186 char tty_name[] = "/dev/tty??";
187
188# ifndef PTYCHAR1
189# define PTYCHAR1 "pqrstuvwxyz"
190# endif
191# ifndef PTYCHAR2
192# define PTYCHAR2 "0123456789abcdef"
193# endif
194
195 for (c1 = PTYCHAR1; *c1; c1++)
196 {
197 pty_name[ (sizeof (pty_name) - 3)] =
198 tty_name[ (sizeof (pty_name) - 3)] = *c1;
199 for (c2 = PTYCHAR2; *c2; c2++)
200 {
201 pty_name[ (sizeof (pty_name) - 2)] =
202 tty_name[ (sizeof (pty_name) - 2)] = *c2;
203 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0)
204 {
205 if (access (tty_name, R_OK | W_OK) == 0)
206 {
207 *ttydev = strdup (tty_name);
208 return pfd;
209 }
210 close (pfd);
211 }
212 }
213 }
214 }
215#endif
216 return -1; 153 return -1;
217} 154}
155#else
156/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */
157static int
158get_pty (int *fd_tty, char **ttydev)
159{
160 int pfd;
161 int i;
162 char pty_name[32];
163 char tty_name[32];
164 const char *majors = "pqrstuvwxyzabcde";
165 const char *minors = "0123456789abcdef";
166 for (i = 0; i < 256; i++)
167 {
168 snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]);
169 snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]);
170 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) == -1)
171 {
172 snprintf(pty_name, 32, "/dev/ptyp%d", i);
173 snprintf(tty_name, 32, "/dev/ttyp%d", i);
174 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) == -1)
175 continue;
176 }
177 if (access (tty_name, R_OK | W_OK) == 0)
178 {
179 *ttydev = strdup (tty_name);
180 return pfd;
181 }
182
183 close (pfd);
184 }
185}
186#endif
218 187
219/*----------------------------------------------------------------------*/ 188/*----------------------------------------------------------------------*/
220/* 189/*
221 * Returns tty file descriptor, or -1 on failure 190 * Returns tty file descriptor, or -1 on failure
222 */ 191 */
223/* EXTPROTO */ 192static int
224int
225rxvt_get_tty (const char *ttydev) 193get_tty (char *ttydev)
226{ 194{
227 return open (ttydev, O_RDWR | O_NOCTTY, 0); 195 return open (ttydev, O_RDWR | O_NOCTTY, 0);
228} 196}
229 197
230/*----------------------------------------------------------------------*/ 198/*----------------------------------------------------------------------*/
231/* 199/*
232 * Make our tty a controlling tty so that /dev/tty points to us 200 * Make our tty a controlling tty so that /dev/tty points to us
233 */ 201 */
234/* EXTPROTO */ 202static int
235int 203control_tty (int fd_tty)
236rxvt_control_tty (int fd_tty, const char *ttydev)
237{ 204{
238#ifndef __QNX__
239 int fd;
240
241 D_TTY ((stderr, "rxvt_control_tty (): pid: %d, tty fd: %d, dev: %s", getpid (), fd_tty, ttydev));
242 /* ---------------------------------------- */
243# ifdef HAVE_SETSID
244 setsid (); 205 setsid ();
245# endif
246# if defined(HAVE_SETPGID)
247 setpgid (0, 0);
248# elif defined(HAVE_SETPGRP)
249 setpgrp (0, 0);
250# endif
251 /* ---------------------------------------- */
252# ifdef TIOCNOTTY
253 206
254 fd = open ("/dev/tty", O_RDWR | O_NOCTTY);
255 D_TTY ((stderr, "rxvt_control_tty (): Voiding tty associations: previous=%s", fd < 0 ? "no" : "yes"));
256 if (fd >= 0)
257 {
258 ioctl (fd, TIOCNOTTY, NULL); /* void tty associations */
259 close (fd);
260 }
261# endif
262 /* ---------------------------------------- */
263 fd = open ("/dev/tty", O_RDWR | O_NOCTTY);
264 D_TTY ((stderr, "rxvt_control_tty (): /dev/tty has controlling tty? %s", fd < 0 ? "no (good)" : "yes (bad)"));
265 if (fd >= 0)
266 close (fd); /* ouch: still have controlling tty */
267 /* ---------------------------------------- */
268#if defined(PTYS_ARE_PTMX) && defined(I_PUSH) 207#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
269 /* 208 /*
270 * Push STREAMS modules: 209 * Push STREAMS modules:
271 * ptem: pseudo-terminal hardware emulation module. 210 * ptem: pseudo-terminal hardware emulation module.
272 * ldterm: standard terminal line discipline. 211 * ldterm: standard terminal line discipline.
273 * ttcompat: V7, 4BSD and XENIX STREAMS compatibility module. 212 * ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
… …
285 */ 224 */
286# ifdef HAVE_ISASTREAM 225# ifdef HAVE_ISASTREAM
287 if (isastream (fd_tty) == 1) 226 if (isastream (fd_tty) == 1)
288# endif 227# endif
289 { 228 {
290 D_TTY ((stderr, "rxvt_control_tty (): Pushing STREAMS modules"));
291 ioctl (fd_tty, I_PUSH, "ptem"); 229 ioctl (fd_tty, I_PUSH, "ptem");
292 ioctl (fd_tty, I_PUSH, "ldterm"); 230 ioctl (fd_tty, I_PUSH, "ldterm");
293 ioctl (fd_tty, I_PUSH, "ttcompat"); 231 ioctl (fd_tty, I_PUSH, "ttcompat");
294 } 232 }
295#endif 233#endif
296 /* ---------------------------------------- */ 234
297# if defined(TIOCSCTTY)
298 fd = ioctl (fd_tty, TIOCSCTTY, NULL); 235 ioctl (fd_tty, TIOCSCTTY, NULL);
299 D_TTY ((stderr, "rxvt_control_tty (): ioctl (..,TIOCSCTTY): %d", fd)); 236
300# elif defined(TIOCSETCTTY) 237 int fd = open ("/dev/tty", O_WRONLY);
301 fd = ioctl (fd_tty, TIOCSETCTTY, NULL);
302 D_TTY ((stderr, "rxvt_control_tty (): ioctl (..,TIOCSETCTTY): %d", fd));
303# else
304 fd = open (ttydev, O_RDWR);
305 D_TTY ((stderr, "rxvt_control_tty (): tty open%s", fd < 0 ? " failure" : "ed OK"));
306 if (fd >= 0) 238 if (fd < 0)
239 return -1; /* fatal */
240
307 close (fd); 241 close (fd);
242
243 return 0;
244}
245
246void
247ptytty::close_tty ()
248{
249 if (tty < 0)
250 return;
251
252 close (tty);
253 tty = -1;
254}
255
256bool
257ptytty::make_controlling_tty ()
258{
259 return control_tty (tty) >= 0;
260}
261
262void
263ptytty::set_utf8_mode (bool on)
264{
265#ifdef IUTF8
266 if (pty < 0)
267 return;
268
269 struct termios tio;
270
271 if (tcgetattr (pty, &tio) != -1)
272 {
273 tcflag_t new_cflag = tio.c_iflag;
274
275 if (on)
276 new_cflag |= IUTF8;
277 else
278 new_cflag &= ~IUTF8;
279
280 if (new_cflag != tio.c_iflag)
281 {
282 tio.c_iflag = new_cflag;
283 tcsetattr (pty, TCSANOW, &tio);
284 }
285 }
286#endif
287}
288
289static struct ttyconf {
290 gid_t gid;
291 mode_t mode;
292
293 ttyconf ()
294 {
295#ifdef TTY_GID_SUPPORT
296 struct group *gr = getgrnam ("tty");
297
298 if (gr)
299 { /* change group ownership of tty to "tty" */
300 mode = S_IRUSR | S_IWUSR | S_IWGRP;
301 gid = gr->gr_gid;
302 }
303 else
304#endif /* TTY_GID_SUPPORT */
305 {
306 mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
307 gid = 0;
308 }
309 }
310} ttyconf;
311
312ptytty_unix::ptytty_unix ()
313{
314 name = 0;
315#if UTMP_SUPPORT
316 cmd_pid = 0;
317#endif
318}
319
320ptytty_unix::~ptytty_unix ()
321{
322#if UTMP_SUPPORT
323 logout ();
324#endif
325 put ();
326}
327
328void
329ptytty_unix::put ()
330{
331 chmod (name, RESTORE_TTY_MODE);
332 chown (name, 0, ttyconf.gid);
333
334 close_tty ();
335
336 if (pty >= 0)
337 close (pty);
338
339 free (name);
340
341 pty = tty = -1;
342 name = 0;
343}
344
345bool
346ptytty_unix::get ()
347{
348 /* get master (pty) */
349 if ((pty = get_pty (&tty, &name)) < 0)
350 return false;
351
352 fcntl (pty, F_SETFL, O_NONBLOCK);
353
354 /* get slave (tty) */
355 if (tty < 0)
356 {
357#ifndef NO_SETOWNER_TTYDEV
358 chown (name, getuid (), ttyconf.gid); /* fail silently */
359 chmod (name, ttyconf.mode);
360# ifdef HAVE_REVOKE
361 revoke (name);
308# endif 362# endif
309 /* ---------------------------------------- */ 363#endif
310 fd = open ("/dev/tty", O_WRONLY);
311 D_TTY ((stderr, "rxvt_control_tty (): do we have controlling tty now: %s", fd < 0 ? "no (fatal)" : "yes (good)"));
312 if (fd < 0)
313 return -1; /* fatal */
314 close (fd);
315 /* ---------------------------------------- */
316 D_TTY ((stderr, "rxvt_control_tty (): tcgetpgrp (): %d getpgrp (): %d", tcgetpgrp (fd_tty), getpgrp ()));
317 /* ---------------------------------------- */
318#endif /* ! __QNX__ */
319 364
365 if ((tty = get_tty (name)) < 0)
366 {
367 put ();
368 return false;
369 }
370 }
371
372 return true;
373}
374
375#if PTYTTY_HELPER
376
377static int sock_fd = -1;
378static int helper_pid, owner_pid;
379
380struct command
381{
382 enum { get, login, destroy } type;
383
384 ptytty *id;
385
386 bool login_shell;
387 int cmd_pid;
388 char hostname[512]; // arbitrary, but should be plenty
389};
390
391struct ptytty_proxy : ptytty
392{
393 ptytty *id;
394
395 ptytty_proxy ()
396 : id(0)
397 {
398 }
399
400 ~ptytty_proxy ();
401
402 bool get ();
403 void login (int cmd_pid, bool login_shell, const char *hostname);
404};
405
406bool
407ptytty_proxy::get ()
408{
409 command cmd;
410
411 cmd.type = command::get;
412
413 write (sock_fd, &cmd, sizeof (cmd));
414
415 if (read (sock_fd, &id, sizeof (id)) != sizeof (id))
416 ptytty_fatal ("protocol error while creating pty using helper process, aborting.\n");
417
418 if (!id)
419 return false;
420
421 if ((pty = recv_fd (sock_fd)) < 0
422 || (tty = recv_fd (sock_fd)) < 0)
423 ptytty_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n");
424
425 return true;
426}
427
428void
429ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname)
430{
431 command cmd;
432
433 cmd.type = command::login;
434 cmd.id = id;
435 cmd.cmd_pid = cmd_pid;
436 cmd.login_shell = login_shell;
437 strncpy (cmd.hostname, hostname, sizeof (cmd.hostname));
438
439 write (sock_fd, &cmd, sizeof (cmd));
440}
441
442ptytty_proxy::~ptytty_proxy ()
443{
444 if (id)
445 {
446 command cmd;
447
448 cmd.type = command::destroy;
449 cmd.id = id;
450
451 write (sock_fd, &cmd, sizeof (cmd));
452 }
453}
454
455static
456void serve ()
457{
458 command cmd;
459 vector<ptytty *> ptys;
460
461 while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command))
462 {
463 if (cmd.type == command::get)
464 {
465 // -> id ptyfd ttyfd
466 cmd.id = new ptytty_unix;
467
468 if (cmd.id->get ())
469 {
470 write (sock_fd, &cmd.id, sizeof (cmd.id));
471 ptys.push_back (cmd.id);
472
473 ptytty::send_fd (sock_fd, cmd.id->pty);
474 ptytty::send_fd (sock_fd, cmd.id->tty);
475 }
476 else
477 {
478 delete cmd.id;
479 cmd.id = 0;
480 write (sock_fd, &cmd.id, sizeof (cmd.id));
481 }
482 }
483 else if (cmd.type == command::login)
484 {
485#if UTMP_SUPPORT
486 if (find (ptys.begin (), ptys.end (), cmd.id))
487 {
488 cmd.hostname[sizeof (cmd.hostname) - 1] = 0;
489 cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname);
490 }
491#endif
492 }
493 else if (cmd.type == command::destroy)
494 {
495 vector<ptytty *>::iterator pty = find (ptys.begin (), ptys.end (), cmd.id);
496
497 if (pty != ptys.end ())
498 {
499 delete *pty;
500 ptys.erase (pty);
501 }
502 }
503 else
504 break;
505 }
506
507 // destroy all ptys
508 for (vector<ptytty *>::iterator i = ptys.end (); i-- > ptys.begin (); )
509 delete *i;
510}
511
512void
513ptytty::use_helper ()
514{
515 int pid = getpid ();
516
517 if (sock_fd >= 0 && pid == owner_pid)
320 return 0; 518 return;
519
520 owner_pid = pid;
521
522 int sv[2];
523
524 if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv))
525 ptytty_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");
526
527 helper_pid = fork ();
528
529 if (helper_pid < 0)
530 ptytty_fatal ("could not create pty/sessiondb helper process, aborting.\n");
531
532 if (helper_pid)
533 {
534 // client, process
535 sock_fd = sv[0];
536 close (sv[1]);
537 fcntl (sock_fd, F_SETFD, FD_CLOEXEC);
538 }
539 else
540 {
541 // server, pty-helper
542 sock_fd = sv[1];
543
544 chdir ("/");
545
546 for (int fd = 0; fd < 1023; fd++)
547 if (fd != sock_fd)
548 close (fd);
549
550 serve ();
551 _exit (EXIT_SUCCESS);
552 }
321} 553}
322/*----------------------- end-of-file (C source) -----------------------*/ 554
555#endif
556
557ptytty *
558ptytty::create ()
559{
560#if PTYTTY_HELPER
561 if (helper_pid && getpid () == owner_pid)
562 // use helper process
563 return new ptytty_proxy;
564 else
565#endif
566 return new ptytty_unix;
567}
568
569void
570ptytty::init ()
571{
572 uid_t uid = getuid ();
573 gid_t gid = getgid ();
574
575 // before doing anything else, check for setuid/setgid operation,
576 // start the helper process and drop privileges
577 if (uid != geteuid ()
578 || gid != getegid ())
579 {
580#if PTYTTY_HELPER
581 use_helper ();
582#else
583 ptytty_warn ("running setuid/setgid without pty helper compiled in, continuing unprivileged.\n");
584#endif
585
586 drop_privileges ();
587 }
588}
589
590void
591ptytty::drop_privileges ()
592{
593 uid_t uid = getuid ();
594 gid_t gid = getgid ();
595
596 // drop privileges
597#if HAVE_SETRESUID
598 setresgid (gid, gid, gid);
599 setresuid (uid, uid, uid);
600#elif HAVE_SETREUID
601 setregid (gid, gid);
602 setreuid (uid, uid);
603#elif HAVE_SETUID
604 setgid (gid);
605 setuid (uid);
606#endif
607
608 if (uid != geteuid ()
609 || gid != getegid ())
610 ptytty_fatal ("unable to drop privileges, aborting.\n");
611}
612

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