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Comparing rxvt-unicode/src/ptytty.C (file contents):
Revision 1.10 by pcg, Fri Apr 2 20:41:01 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 <cstdio>
36#ifdef HAVE_STDLIB_H
37# include <cstdlib> 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 <cstring>
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#ifdef HAVE_ISASTREAM 46#ifdef HAVE_ISASTREAM
58# include <stropts.h> 47# include <stropts.h>
59#endif 48#endif
60 49#if defined(HAVE_PTY_H)
61#ifdef DEBUG_TTY 50# include <pty.h>
62# define D_TTY(x) fprintf x ; fputc('\n', stderr) ; fflush(stderr) 51#elif defined(HAVE_LIBUTIL_H)
63#else 52# include <libutil.h>
64# define D_TTY(x) 53#elif defined(HAVE_UTIL_H)
54# include <util.h>
65#endif 55#endif
56#ifdef TTY_GID_SUPPORT
57#include <grp.h>
58#endif
59
60#include <cstdio>
61
62/////////////////////////////////////////////////////////////////////////////
66 63
67/* ------------------------------------------------------------------------- * 64/* ------------------------------------------------------------------------- *
68 * GET PSEUDO TELETYPE - MASTER AND SLAVE * 65 * GET PSEUDO TELETYPE - MASTER AND SLAVE *
69 * ------------------------------------------------------------------------- */ 66 * ------------------------------------------------------------------------- */
70/* 67/*
71 * Returns pty file descriptor, or -1 on failure 68 * Returns pty file descriptor, or -1 on failure
72 * 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.
73 * 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
74 */ 71 */
75/* EXTPROTO */ 72#if defined(UNIX98_PTY)
76int 73static int
77rxvt_get_pty (int *fd_tty, const char **ttydev) 74get_pty (int *fd_tty, char **ttydev)
78{ 75{
79 int pfd; 76 int pfd;
80 77
81#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 }
82 93
83 char tty_name[sizeof "/dev/pts/????\0"]; 94 close (pfd);
95 }
84 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
85 if (openpty (&pfd, fd_tty, tty_name, NULL, NULL) != -1) 107 res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);
108 if (res != -1)
86 { 109 {
87 *ttydev = strdup (tty_name); 110 *ttydev = strdup (tty_name);
88 return pfd; 111 return pfd;
89 } 112 }
90#endif
91 113
92#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
93 *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0); 122 *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0);
94 if (*ttydev != NULL) 123 if (*ttydev != NULL)
95 return pfd; 124 return pfd;
96#endif
97 125
98#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;
99 133
100 char *ptydev;
101
102 while ((ptydev = getpty ()) != NULL)
103 if ((pfd = open (ptydev, O_RDWR | O_NOCTTY, 0)) >= 0)
104 {
105 *ttydev = ptydev;
106 return pfd;
107 }
108#endif
109
110#if defined(HAVE_GRANTPT) && defined(HAVE_UNLOCKPT)
111# if defined(PTYS_ARE_GETPT) || defined(PTYS_ARE_PTMX)
112
113 {
114# ifdef PTYS_ARE_GETPT
115 pfd = getpt ();
116# else
117
118 pfd = open ("/dev/ptmx", O_RDWR | O_NOCTTY, 0);
119# endif
120
121 if (pfd >= 0)
122 {
123 if (grantpt (pfd) == 0 /* change slave permissions */
124 && unlockpt (pfd) == 0)
125 { /* slave now unlocked */
126 *ttydev = ptsname (pfd); /* get slave's name */
127 return pfd;
128 }
129 close (pfd);
130 }
131 }
132# endif
133#endif
134
135#ifdef PTYS_ARE_PTC
136 if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0) 134 if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0)
137 { 135 {
138 *ttydev = ttyname (pfd); 136 *ttydev = strdup (ttyname (pfd));
139 return pfd; 137 return pfd;
140 } 138 }
141#endif
142 139
143#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
144 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)
145 { 149 {
146 *ttydev = ptsname (pfd); 150 *ttydev = strdup (ptsname (pfd));
147 return pfd; 151 return pfd;
148 } 152 }
149#endif
150 153
151#ifdef PTYS_ARE_NUMERIC
152 {
153 int idx;
154 char *c1, *c2;
155 char pty_name[] = "/dev/ptyp???";
156 char tty_name[] = "/dev/ttyp???";
157
158 c1 = & (pty_name[sizeof (pty_name) - 4]);
159 c2 = & (tty_name[sizeof (tty_name) - 4]);
160 for (idx = 0; idx < 256; idx++)
161 {
162 sprintf (c1, "%d", idx);
163 sprintf (c2, "%d", idx);
164 if (access (tty_name, F_OK) < 0)
165 {
166 idx = 256;
167 break;
168 }
169 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0)
170 {
171 if (access (tty_name, R_OK | W_OK) == 0)
172 {
173 *ttydev = strdup (tty_name);
174 return pfd;
175 }
176 close (pfd);
177 }
178 }
179 }
180#endif
181#ifdef PTYS_ARE_SEARCHED
182 {
183 const char *c1, *c2;
184 char pty_name[] = "/dev/pty??";
185 char tty_name[] = "/dev/tty??";
186
187# ifndef PTYCHAR1
188# define PTYCHAR1 "pqrstuvwxyz"
189# endif
190# ifndef PTYCHAR2
191# define PTYCHAR2 "0123456789abcdef"
192# endif
193
194 for (c1 = PTYCHAR1; *c1; c1++)
195 {
196 pty_name[ (sizeof (pty_name) - 3)] =
197 tty_name[ (sizeof (pty_name) - 3)] = *c1;
198 for (c2 = PTYCHAR2; *c2; c2++)
199 {
200 pty_name[ (sizeof (pty_name) - 2)] =
201 tty_name[ (sizeof (pty_name) - 2)] = *c2;
202 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0)
203 {
204 if (access (tty_name, R_OK | W_OK) == 0)
205 {
206 *ttydev = strdup (tty_name);
207 return pfd;
208 }
209 close (pfd);
210 }
211 }
212 }
213 }
214#endif
215 return -1; 154 return -1;
216} 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
217 188
218/*----------------------------------------------------------------------*/ 189/*----------------------------------------------------------------------*/
219/* 190/*
220 * Returns tty file descriptor, or -1 on failure 191 * Returns tty file descriptor, or -1 on failure
221 */ 192 */
222/* EXTPROTO */ 193static int
223int
224rxvt_get_tty (const char *ttydev) 194get_tty (char *ttydev)
225{ 195{
226 return open (ttydev, O_RDWR | O_NOCTTY, 0); 196 return open (ttydev, O_RDWR | O_NOCTTY, 0);
227} 197}
228 198
229/*----------------------------------------------------------------------*/ 199/*----------------------------------------------------------------------*/
230/* 200/*
231 * 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
232 */ 202 */
233/* EXTPROTO */ 203static int
234int 204control_tty (int fd_tty)
235rxvt_control_tty (int fd_tty, const char *ttydev)
236{ 205{
237#ifndef __QNX__
238 int fd;
239
240 D_TTY ((stderr, "rxvt_control_tty (): pid: %d, tty fd: %d, dev: %s", getpid (), fd_tty, ttydev));
241 /* ---------------------------------------- */
242# ifdef HAVE_SETSID
243 setsid (); 206 setsid ();
244# endif
245# if defined(HAVE_SETPGID)
246 setpgid (0, 0);
247# elif defined(HAVE_SETPGRP)
248 setpgrp (0, 0);
249# endif
250 /* ---------------------------------------- */
251# ifdef TIOCNOTTY
252 207
253 fd = open ("/dev/tty", O_RDWR | O_NOCTTY);
254 D_TTY ((stderr, "rxvt_control_tty (): Voiding tty associations: previous=%s", fd < 0 ? "no" : "yes"));
255 if (fd >= 0)
256 {
257 ioctl (fd, TIOCNOTTY, NULL); /* void tty associations */
258 close (fd);
259 }
260# endif
261 /* ---------------------------------------- */
262 fd = open ("/dev/tty", O_RDWR | O_NOCTTY);
263 D_TTY ((stderr, "rxvt_control_tty (): /dev/tty has controlling tty? %s", fd < 0 ? "no (good)" : "yes (bad)"));
264 if (fd >= 0)
265 close (fd); /* ouch: still have controlling tty */
266 /* ---------------------------------------- */
267#if defined(PTYS_ARE_PTMX) && defined(I_PUSH) 208#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
268 /* 209 /*
269 * Push STREAMS modules: 210 * Push STREAMS modules:
270 * ptem: pseudo-terminal hardware emulation module. 211 * ptem: pseudo-terminal hardware emulation module.
271 * ldterm: standard terminal line discipline. 212 * ldterm: standard terminal line discipline.
272 * ttcompat: V7, 4BSD and XENIX STREAMS compatibility module. 213 * ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
… …
284 */ 225 */
285# ifdef HAVE_ISASTREAM 226# ifdef HAVE_ISASTREAM
286 if (isastream (fd_tty) == 1) 227 if (isastream (fd_tty) == 1)
287# endif 228# endif
288 { 229 {
289 D_TTY ((stderr, "rxvt_control_tty (): Pushing STREAMS modules"));
290 ioctl (fd_tty, I_PUSH, "ptem"); 230 ioctl (fd_tty, I_PUSH, "ptem");
291 ioctl (fd_tty, I_PUSH, "ldterm"); 231 ioctl (fd_tty, I_PUSH, "ldterm");
292 ioctl (fd_tty, I_PUSH, "ttcompat"); 232 ioctl (fd_tty, I_PUSH, "ttcompat");
293 } 233 }
294#endif 234#endif
295 /* ---------------------------------------- */ 235
296# if defined(TIOCSCTTY)
297 fd = ioctl (fd_tty, TIOCSCTTY, NULL); 236 ioctl (fd_tty, TIOCSCTTY, NULL);
298 D_TTY ((stderr, "rxvt_control_tty (): ioctl (..,TIOCSCTTY): %d", fd)); 237
299# elif defined(TIOCSETCTTY) 238 int fd = open ("/dev/tty", O_WRONLY);
300 fd = ioctl (fd_tty, TIOCSETCTTY, NULL);
301 D_TTY ((stderr, "rxvt_control_tty (): ioctl (..,TIOCSETCTTY): %d", fd));
302# else
303 fd = open (ttydev, O_RDWR);
304 D_TTY ((stderr, "rxvt_control_tty (): tty open%s", fd < 0 ? " failure" : "ed OK"));
305 if (fd >= 0) 239 if (fd < 0)
240 return -1; /* fatal */
241
306 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);
307# endif 363# endif
308 /* ---------------------------------------- */ 364#endif
309 fd = open ("/dev/tty", O_WRONLY);
310 D_TTY ((stderr, "rxvt_control_tty (): do we have controlling tty now: %s", fd < 0 ? "no (fatal)" : "yes (good)"));
311 if (fd < 0)
312 return -1; /* fatal */
313 close (fd);
314 /* ---------------------------------------- */
315 D_TTY ((stderr, "rxvt_control_tty (): tcgetpgrp (): %d getpgrp (): %d", tcgetpgrp (fd_tty), getpgrp ()));
316 /* ---------------------------------------- */
317#endif /* ! __QNX__ */
318 365
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)
319 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 }
320} 554}
321/*----------------------- 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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