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Revision 1.39 by root, Tue Jan 17 12:22:59 2006 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>
7 * Copyright (c) 2004-2006 Marc Lehmann <pcg@goof.com> 10 * Copyright (c) 2004-2006 Marc Lehmann <pcg@goof.com>
11 * Copyright (c) 2006 Emanuele Giaquinta <e.giaquinta@glauco.it>
8 * 12 *
9 * 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
10 * 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
11 * the Free Software Foundation; either version 2 of the License, or 15 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version. 16 * (at your option) any later version.
19 * 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
20 * along with this program; if not, write to the Free Software 24 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 *---------------------------------------------------------------------*/ 26 *---------------------------------------------------------------------*/
23 27
24#include "../config.h" /* NECESSARY */ 28#include "../config.h"
29
25#include "rxvt.h" 30#include "ptytty.h"
26 31
27# include <cstdlib> 32#include <cstdlib>
28# include <cstring> 33#include <cstring>
29 34
30#ifdef HAVE_SYS_TYPES_H
31# include <sys/types.h> 35#include <sys/types.h>
32#endif 36#include <sys/socket.h>
33#ifdef HAVE_UNISTD_H
34# include <unistd.h> 37#include <unistd.h>
35#endif
36#ifdef HAVE_FCNTL_H
37# include <fcntl.h> 38#include <fcntl.h>
38#endif 39
39#ifdef HAVE_SYS_IOCTL_H 40#ifdef HAVE_SYS_IOCTL_H
40# include <sys/ioctl.h> 41# include <sys/ioctl.h>
41#endif 42#endif
42#if defined(PTYS_ARE_PTMX) && defined(HAVE_SYS_STROPTS_H) 43#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H)
43# include <sys/stropts.h> /* for I_PUSH */ 44# include <sys/stropts.h> /* for I_PUSH */
44#endif 45#endif
45#ifdef HAVE_ISASTREAM 46#ifdef HAVE_ISASTREAM
46# include <stropts.h> 47# include <stropts.h>
47#endif 48#endif
50#elif defined(HAVE_LIBUTIL_H) 51#elif defined(HAVE_LIBUTIL_H)
51# include <libutil.h> 52# include <libutil.h>
52#elif defined(HAVE_UTIL_H) 53#elif defined(HAVE_UTIL_H)
53# include <util.h> 54# include <util.h>
54#endif 55#endif
56#ifdef TTY_GID_SUPPORT
57#include <grp.h>
58#endif
55 59
56#include <cstdio> 60#include <cstdio>
57#include <grp.h>
58
59#include "ptytty.h"
60 61
61///////////////////////////////////////////////////////////////////////////// 62/////////////////////////////////////////////////////////////////////////////
62 63
63/* ------------------------------------------------------------------------- * 64/* ------------------------------------------------------------------------- *
64 * GET PSEUDO TELETYPE - MASTER AND SLAVE * 65 * GET PSEUDO TELETYPE - MASTER AND SLAVE *
66/* 67/*
67 * Returns pty file descriptor, or -1 on failure 68 * Returns pty file descriptor, or -1 on failure
68 * 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.
69 * 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
70 */ 71 */
72#if defined(UNIX98_PTY)
71static int 73static int
72get_pty (int *fd_tty, char **ttydev) 74get_pty (int *fd_tty, char **ttydev)
73{ 75{
74 int pfd; 76 int pfd;
75 77
76#ifdef PTYS_ARE_OPENPTY 78# if defined(HAVE_GETPT)
77 char tty_name[sizeof "/dev/pts/????\0"]; 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 }
78 93
79 rxvt_privileges(RESTORE); 94 close (pfd);
95 }
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
80 int res = openpty (&pfd, fd_tty, tty_name, NULL, NULL); 107 res = openpty (&pfd, fd_tty, tty_name, NULL, NULL);
81 rxvt_privileges(IGNORE);
82
83 if (res != -1) 108 if (res != -1)
84 { 109 {
85 *ttydev = strdup (tty_name); 110 *ttydev = strdup (tty_name);
86 return pfd; 111 return pfd;
87 } 112 }
88#endif
89 113
90#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
91 *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0); 122 *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0);
92 if (*ttydev != NULL) 123 if (*ttydev != NULL)
93 return pfd; 124 return pfd;
94#endif
95 125
96#if defined(HAVE_GRANTPT) && defined(HAVE_UNLOCKPT) 126 return -1;
97# if defined(PTYS_ARE_GETPT) || defined(PTYS_ARE_POSIX) || defined(PTYS_ARE_PTMX) 127}
128#elif defined(HAVE_DEV_PTC)
129static int
130get_pty (int *fd_tty, char **ttydev)
131{
132 int pfd;
98 133
99 {
100# ifdef PTYS_ARE_GETPT
101 pfd = getpt();
102# else
103# ifdef PTYS_ARE_POSIX
104 pfd = posix_openpt (O_RDWR);
105# else
106 pfd = open ("/dev/ptmx", O_RDWR | O_NOCTTY, 0);
107# endif
108# endif
109
110 if (pfd >= 0)
111 {
112 if (grantpt (pfd) == 0 /* change slave permissions */
113 && unlockpt (pfd) == 0)
114 { /* slave now unlocked */
115 *ttydev = strdup (ptsname (pfd)); /* get slave's name */
116 return pfd;
117 }
118 close (pfd);
119 }
120 }
121# endif
122#endif
123
124#ifdef PTYS_ARE_PTC
125 if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0) 134 if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0)
126 { 135 {
127 *ttydev = strdup (ttyname (pfd)); 136 *ttydev = strdup (ttyname (pfd));
128 return pfd; 137 return pfd;
129 } 138 }
130#endif
131 139
132#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
133 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)
134 { 149 {
135 *ttydev = strdup (ptsname (pfd)); 150 *ttydev = strdup (ptsname (pfd));
136 return pfd; 151 return pfd;
137 } 152 }
138#endif
139
140#ifdef PTYS_ARE_NUMERIC
141 {
142 int idx;
143 char *c1, *c2;
144 char pty_name[] = "/dev/ptyp???";
145 char tty_name[] = "/dev/ttyp???";
146
147 c1 = &(pty_name[sizeof (pty_name) - 4]);
148 c2 = &(tty_name[sizeof (tty_name) - 4]);
149 for (idx = 0; idx < 256; idx++)
150 {
151 sprintf (c1, "%d", idx);
152 sprintf (c2, "%d", idx);
153 if (access (tty_name, F_OK) < 0)
154 {
155 idx = 256;
156 break;
157 }
158
159 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0)
160 {
161 if (access (tty_name, R_OK | W_OK) == 0)
162 {
163 *ttydev = strdup (tty_name);
164 return pfd;
165 }
166
167 close (pfd);
168 }
169 }
170 }
171#endif
172
173#ifdef PTYS_ARE_SEARCHED
174 {
175 const char *c1, *c2;
176 char pty_name[] = "/dev/pty??";
177 char tty_name[] = "/dev/tty??";
178
179# ifndef PTYCHAR1
180# define PTYCHAR1 "pqrstuvwxyz"
181# endif
182# ifndef PTYCHAR2
183# define PTYCHAR2 "0123456789abcdef"
184# endif
185
186 for (c1 = PTYCHAR1; *c1; c1++)
187 {
188 pty_name[ (sizeof (pty_name) - 3)] =
189 tty_name[ (sizeof (pty_name) - 3)] = *c1;
190 for (c2 = PTYCHAR2; *c2; c2++)
191 {
192 pty_name[ (sizeof (pty_name) - 2)] =
193 tty_name[ (sizeof (pty_name) - 2)] = *c2;
194 if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0)
195 {
196 if (access (tty_name, R_OK | W_OK) == 0)
197 {
198 *ttydev = strdup (tty_name);
199 return pfd;
200 }
201
202 close (pfd);
203 }
204 }
205 }
206 }
207#endif
208 153
209 return -1; 154 return -1;
210} 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
211 188
212/*----------------------------------------------------------------------*/ 189/*----------------------------------------------------------------------*/
213/* 190/*
214 * Returns tty file descriptor, or -1 on failure 191 * Returns tty file descriptor, or -1 on failure
215 */ 192 */
224 * 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
225 */ 202 */
226static int 203static int
227control_tty (int fd_tty) 204control_tty (int fd_tty)
228{ 205{
229 int fd;
230
231 /* ---------------------------------------- */
232 setsid (); 206 setsid ();
233 207
234 /* ---------------------------------------- */
235# if defined(PTYS_ARE_PTMX) && defined(I_PUSH) 208#if defined(HAVE_DEV_PTMX) && defined(I_PUSH)
236 /* 209 /*
237 * Push STREAMS modules: 210 * Push STREAMS modules:
238 * ptem: pseudo-terminal hardware emulation module. 211 * ptem: pseudo-terminal hardware emulation module.
239 * ldterm: standard terminal line discipline. 212 * ldterm: standard terminal line discipline.
240 * ttcompat: V7, 4BSD and XENIX STREAMS compatibility module. 213 * ttcompat: V7, 4BSD and XENIX STREAMS compatibility module.
248 * documentation is really unclear about whether it is any close () on 221 * documentation is really unclear about whether it is any close () on
249 * the master side or the last close () - i.e. a proper STREAMS dismantling 222 * the master side or the last close () - i.e. a proper STREAMS dismantling
250 * close () - on the master side which causes a hang up to be sent 223 * close () - on the master side which causes a hang up to be sent
251 * through - Geoff Wing 224 * through - Geoff Wing
252 */ 225 */
253# ifdef HAVE_ISASTREAM 226# ifdef HAVE_ISASTREAM
254 if (isastream (fd_tty) == 1) 227 if (isastream (fd_tty) == 1)
255# endif 228# endif
256 { 229 {
257 ioctl (fd_tty, I_PUSH, "ptem"); 230 ioctl (fd_tty, I_PUSH, "ptem");
258 ioctl (fd_tty, I_PUSH, "ldterm"); 231 ioctl (fd_tty, I_PUSH, "ldterm");
259 ioctl (fd_tty, I_PUSH, "ttcompat"); 232 ioctl (fd_tty, I_PUSH, "ttcompat");
260 } 233 }
261# endif 234#endif
262 /* ---------------------------------------- */ 235
263 fd = ioctl (fd_tty, TIOCSCTTY, NULL); 236 ioctl (fd_tty, TIOCSCTTY, NULL);
264 /* ---------------------------------------- */ 237
265 fd = open ("/dev/tty", O_WRONLY); 238 int fd = open ("/dev/tty", O_WRONLY);
266 if (fd < 0) 239 if (fd < 0)
267 return -1; /* fatal */ 240 return -1; /* fatal */
241
268 close (fd); 242 close (fd);
269 /* ---------------------------------------- */
270 243
271 return 0; 244 return 0;
272} 245}
273 246
274void 247void
275rxvt_ptytty::close_tty () 248ptytty::close_tty ()
276{ 249{
277 if (tty < 0) 250 if (tty < 0)
278 return; 251 return;
279 252
280 close (tty); 253 close (tty);
281 tty = -1; 254 tty = -1;
282} 255}
283 256
284bool 257bool
285rxvt_ptytty::make_controlling_tty () 258ptytty::make_controlling_tty ()
286{ 259{
287 return control_tty (tty) >= 0; 260 return control_tty (tty) >= 0;
288} 261}
289 262
290void 263void
291rxvt_ptytty::set_utf8_mode (bool on) 264ptytty::set_utf8_mode (bool on)
292{ 265{
293#ifdef IUTF8 266#ifdef IUTF8
294 if (pty < 0) 267 if (pty < 0)
295 return; 268 return;
296 269
312 } 285 }
313 } 286 }
314#endif 287#endif
315} 288}
316 289
317/////////////////////////////////////////////////////////////////////////////
318
319#ifndef NO_SETOWNER_TTYDEV
320static struct ttyconf { 290static struct ttyconf {
321 gid_t gid; 291 gid_t gid;
322 mode_t mode; 292 mode_t mode;
323 293
324 ttyconf () 294 ttyconf ()
333 } 303 }
334 else 304 else
335#endif /* TTY_GID_SUPPORT */ 305#endif /* TTY_GID_SUPPORT */
336 { 306 {
337 mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH; 307 mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
338 gid = getgid (); 308 gid = 0;
339 } 309 }
340 } 310 }
341} ttyconf; 311} ttyconf;
342 312
343///////////////////////////////////////////////////////////////////////////// 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}
344 328
345void 329void
346rxvt_ptytty_unix::privileges (rxvt_privaction action) 330ptytty_unix::put ()
347{ 331{
348 if (!name || !*name) 332 chmod (name, RESTORE_TTY_MODE);
349 return; 333 chown (name, 0, ttyconf.gid);
350 334
351 rxvt_privileges (RESTORE); 335 close_tty ();
352 336
353 if (action == SAVE) 337 if (pty >= 0)
354 { 338 close (pty);
355# ifndef RESET_TTY_TO_COMMON_DEFAULTS
356 /* store original tty status for restoration rxvt_clean_exit () -- rgg 04/12/95 */
357 if (lstat (name, &savestat) < 0) /* you lose out */
358 ;
359 else
360# endif
361 {
362 saved = true;
363 chown (name, getuid (), ttyconf.gid); /* fail silently */
364 chmod (name, ttyconf.mode);
365# ifdef HAVE_REVOKE
366 revoke (name);
367# endif
368 }
369 }
370 else
371 { /* action == RESTORE */
372# ifndef RESET_TTY_TO_COMMON_DEFAULTS
373 if (saved)
374 {
375 chmod (name, savestat.st_mode);
376 chown (name, savestat.st_uid, savestat.st_gid);
377 }
378# else
379 chmod (name, (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH));
380 chown (name, 0, 0);
381# endif
382 339
383 } 340 free (name);
384 341
385 rxvt_privileges (IGNORE);
386}
387#endif
388
389rxvt_ptytty_unix::rxvt_ptytty_unix ()
390{
391 pty = tty = -1; 342 pty = tty = -1;
392 name = 0; 343 name = 0;
393#ifndef NO_SETOWNER_TTYDEV
394 saved = false;
395#endif
396#if UTMP_SUPPORT
397 cmd_pid = 0;
398#endif
399}
400
401rxvt_ptytty_unix::~rxvt_ptytty_unix ()
402{
403 logout ();
404 put ();
405}
406
407void
408rxvt_ptytty_unix::put ()
409{
410#ifndef NO_SETOWNER_TTYDEV
411 privileges (RESTORE);
412#endif
413
414 if (pty >= 0) close (pty);
415 close_tty ();
416 free (name);
417
418 pty = tty = -1;
419 name = 0;
420} 344}
421 345
422bool 346bool
423rxvt_ptytty_unix::get () 347ptytty_unix::get ()
424{ 348{
425 /* get master (pty) */ 349 /* get master (pty) */
426 if ((pty = get_pty (&tty, &name)) < 0) 350 if ((pty = get_pty (&tty, &name)) < 0)
427 return false; 351 return false;
428 352
430 354
431 /* get slave (tty) */ 355 /* get slave (tty) */
432 if (tty < 0) 356 if (tty < 0)
433 { 357 {
434#ifndef NO_SETOWNER_TTYDEV 358#ifndef NO_SETOWNER_TTYDEV
435 privileges (SAVE); 359 chown (name, getuid (), ttyconf.gid); /* fail silently */
360 chmod (name, ttyconf.mode);
361# ifdef HAVE_REVOKE
362 revoke (name);
363# endif
436#endif 364#endif
437 365
438 if ((tty = get_tty (name)) < 0) 366 if ((tty = get_tty (name)) < 0)
439 { 367 {
440 put (); 368 put ();
443 } 371 }
444 372
445 return true; 373 return true;
446} 374}
447 375
448// a "factory" *g* 376#if PTYTTY_HELPER
449rxvt_ptytty *rxvt_new_ptytty () 377
378static int sock_fd = -1;
379static int helper_pid, owner_pid;
380
381struct command
450{ 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)
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 }
554}
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
451 return new rxvt_ptytty_unix; 567 return new ptytty_unix;
452} 568}
453 569
454/*----------------------- end-of-file (C source) -----------------------*/ 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
455 586
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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