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Comparing rxvt-unicode/src/ptytty.C (file contents):
Revision 1.53 by ayin, Sat Jan 21 18:15:26 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#include <sys/types.h> 35#include <sys/types.h>
… …
51#ifdef TTY_GID_SUPPORT 56#ifdef TTY_GID_SUPPORT
52#include <grp.h> 57#include <grp.h>
53#endif 58#endif
54 59
55#include <cstdio> 60#include <cstdio>
56
57#include "rxvtutil.h"
58#include "fdpass.h"
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 *
… …
234 235
235 ioctl (fd_tty, TIOCSCTTY, NULL); 236 ioctl (fd_tty, TIOCSCTTY, NULL);
236 237
237 int fd = open ("/dev/tty", O_WRONLY); 238 int fd = open ("/dev/tty", O_WRONLY);
238 if (fd < 0) 239 if (fd < 0)
239 return -1; /* fatal */ 240 return -1; /* fatal */
240 241
241 close (fd); 242 close (fd);
242 243
243 return 0; 244 return 0;
244} 245}
245 246
246void 247void
247rxvt_ptytty::close_tty () 248ptytty::close_tty ()
248{ 249{
249 if (tty < 0) 250 if (tty < 0)
250 return; 251 return;
251 252
252 close (tty); 253 close (tty);
253 tty = -1; 254 tty = -1;
254} 255}
255 256
256bool 257bool
257rxvt_ptytty::make_controlling_tty () 258ptytty::make_controlling_tty ()
258{ 259{
259 return control_tty (tty) >= 0; 260 return control_tty (tty) >= 0;
260} 261}
261 262
262void 263void
263rxvt_ptytty::set_utf8_mode (bool on) 264ptytty::set_utf8_mode (bool on)
264{ 265{
265#ifdef IUTF8 266#ifdef IUTF8
266 if (pty < 0) 267 if (pty < 0)
267 return; 268 return;
268 269
… …
307 gid = 0; 308 gid = 0;
308 } 309 }
309 } 310 }
310} ttyconf; 311} ttyconf;
311 312
312rxvt_ptytty_unix::rxvt_ptytty_unix () 313ptytty_unix::ptytty_unix ()
313{ 314{
314 name = 0; 315 name = 0;
315#if UTMP_SUPPORT 316#if UTMP_SUPPORT
316 cmd_pid = 0; 317 cmd_pid = 0;
317#endif 318#endif
318} 319}
319 320
320rxvt_ptytty_unix::~rxvt_ptytty_unix () 321ptytty_unix::~ptytty_unix ()
321{ 322{
322#if UTMP_SUPPORT 323#if UTMP_SUPPORT
323 logout (); 324 logout ();
324#endif 325#endif
325 put (); 326 put ();
326} 327}
327 328
328void 329void
329rxvt_ptytty_unix::put () 330ptytty_unix::put ()
330{ 331{
331 chmod (name, RESTORE_TTY_MODE); 332 chmod (name, RESTORE_TTY_MODE);
332 chown (name, 0, ttyconf.gid); 333 chown (name, 0, ttyconf.gid);
333 334
334 close_tty (); 335 close_tty ();
… …
341 pty = tty = -1; 342 pty = tty = -1;
342 name = 0; 343 name = 0;
343} 344}
344 345
345bool 346bool
346rxvt_ptytty_unix::get () 347ptytty_unix::get ()
347{ 348{
348 /* get master (pty) */ 349 /* get master (pty) */
349 if ((pty = get_pty (&tty, &name)) < 0) 350 if ((pty = get_pty (&tty, &name)) < 0)
350 return false; 351 return false;
351 352
… …
372 return true; 373 return true;
373} 374}
374 375
375#if PTYTTY_HELPER 376#if PTYTTY_HELPER
376 377
377static int sock_fd; 378static int sock_fd = -1;
378static int pid; 379static int helper_pid, owner_pid;
379 380
380struct command 381struct command
381{ 382{
382 enum { get, login, destroy } type; 383 enum { get, login, destroy } type;
383 384
384 rxvt_ptytty *id; 385 ptytty *id;
385 386
386 bool login_shell; 387 bool login_shell;
387 int cmd_pid; 388 int cmd_pid;
388 char hostname[512]; // arbitrary, but should be plenty 389 char hostname[512]; // arbitrary, but should be plenty
389}; 390};
390 391
391struct rxvt_ptytty_proxy : zero_initialized, rxvt_ptytty 392struct ptytty_proxy : ptytty
392{ 393{
393 rxvt_ptytty *id; 394 ptytty *id;
394 395
396 ptytty_proxy ()
397 : id(0)
398 {
399 }
400
395 ~rxvt_ptytty_proxy (); 401 ~ptytty_proxy ();
396 402
397 bool get (); 403 bool get ();
398 void login (int cmd_pid, bool login_shell, const char *hostname); 404 void login (int cmd_pid, bool login_shell, const char *hostname);
399}; 405};
400 406
401bool 407bool
402rxvt_ptytty_proxy::get () 408ptytty_proxy::get ()
403{ 409{
404 command cmd; 410 command cmd;
405 411
406 cmd.type = command::get; 412 cmd.type = command::get;
407 413
408 write (sock_fd, &cmd, sizeof (cmd)); 414 write (sock_fd, &cmd, sizeof (cmd));
409 415
410 if (read (sock_fd, &id, sizeof (id)) != sizeof (id)) 416 if (read (sock_fd, &id, sizeof (id)) != sizeof (id))
411 rxvt_fatal ("protocol error while creating pty using helper process, aborting.\n"); 417 ptytty_fatal ("protocol error while creating pty using helper process, aborting.\n");
412 418
413 if (!id) 419 if (!id)
414 return false; 420 return false;
415 421
416 if ((pty = rxvt_recv_fd (sock_fd)) < 0 422 if ((pty = recv_fd (sock_fd)) < 0
417 || (tty = rxvt_recv_fd (sock_fd)) < 0) 423 || (tty = recv_fd (sock_fd)) < 0)
418 rxvt_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n"); 424 ptytty_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n");
419 425
420 return true; 426 return true;
421} 427}
422 428
423void 429void
424rxvt_ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname) 430ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname)
425{ 431{
426 command cmd; 432 command cmd;
427 433
428 cmd.type = command::login; 434 cmd.type = command::login;
429 cmd.id = id; 435 cmd.id = id;
… …
432 strncpy (cmd.hostname, hostname, sizeof (cmd.hostname)); 438 strncpy (cmd.hostname, hostname, sizeof (cmd.hostname));
433 439
434 write (sock_fd, &cmd, sizeof (cmd)); 440 write (sock_fd, &cmd, sizeof (cmd));
435} 441}
436 442
437rxvt_ptytty_proxy::~rxvt_ptytty_proxy () 443ptytty_proxy::~ptytty_proxy ()
438{ 444{
445 if (id)
446 {
439 command cmd; 447 command cmd;
440 448
441 cmd.type = command::destroy; 449 cmd.type = command::destroy;
442 cmd.id = id; 450 cmd.id = id;
443 451
444 write (sock_fd, &cmd, sizeof (cmd)); 452 write (sock_fd, &cmd, sizeof (cmd));
453 }
445} 454}
446 455
447static 456static
448void serve () 457void serve ()
449{ 458{
450 command cmd; 459 command cmd;
451 vector<rxvt_ptytty *> ptys; 460 vector<ptytty *> ptys;
452 461
453 while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command)) 462 while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command))
454 { 463 {
455 if (cmd.type == command::get) 464 if (cmd.type == command::get)
456 { 465 {
457 // -> id ptyfd ttyfd 466 // -> id ptyfd ttyfd
458 cmd.id = new rxvt_ptytty_unix; 467 cmd.id = new ptytty_unix;
459 468
460 if (cmd.id->get ()) 469 if (cmd.id->get ())
461 { 470 {
462 write (sock_fd, &cmd.id, sizeof (cmd.id)); 471 write (sock_fd, &cmd.id, sizeof (cmd.id));
463 ptys.push_back (cmd.id); 472 ptys.push_back (cmd.id);
464 473
465 rxvt_send_fd (sock_fd, cmd.id->pty); 474 ptytty::send_fd (sock_fd, cmd.id->pty);
466 rxvt_send_fd (sock_fd, cmd.id->tty); 475 ptytty::send_fd (sock_fd, cmd.id->tty);
467 } 476 }
468 else 477 else
469 { 478 {
470 delete cmd.id; 479 delete cmd.id;
471 cmd.id = 0; 480 cmd.id = 0;
… …
482 } 491 }
483#endif 492#endif
484 } 493 }
485 else if (cmd.type == command::destroy) 494 else if (cmd.type == command::destroy)
486 { 495 {
487 rxvt_ptytty **pty = find (ptys.begin (), ptys.end (), cmd.id); 496 vector<ptytty *>::iterator pty = find (ptys.begin (), ptys.end (), cmd.id);
488 497
489 if (pty) 498 if (pty != ptys.end ())
490 { 499 {
491 delete *pty; 500 delete *pty;
492 ptys.erase (pty); 501 ptys.erase (pty);
493 } 502 }
494 } 503 }
495 else 504 else
496 break; 505 break;
497 } 506 }
498 507
499 // destroy all ptys 508 // destroy all ptys
500 for (rxvt_ptytty **i = ptys.end (); i-- > ptys.begin (); ) 509 for (vector<ptytty *>::iterator i = ptys.end (); i-- > ptys.begin (); )
501 delete *i; 510 delete *i;
502} 511}
503 512
504void rxvt_ptytty_server () 513void
514ptytty::use_helper ()
505{ 515{
516 int pid = getpid ();
517
518 if (sock_fd >= 0 && pid == owner_pid)
519 return;
520
521 owner_pid = pid;
522
506 int sv[2]; 523 int sv[2];
507 524
508 if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv)) 525 if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv))
509 rxvt_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n"); 526 ptytty_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");
510 527
511 pid = fork (); 528 helper_pid = fork ();
512 529
513 if (pid < 0) 530 if (helper_pid < 0)
514 rxvt_fatal ("could not create pty/sessiondb helper process, aborting.\n"); 531 ptytty_fatal ("could not create pty/sessiondb helper process, aborting.\n");
515 532
516 if (pid) 533 if (helper_pid)
517 { 534 {
518 // client, urxvt 535 // client, process
519 sock_fd = sv[0]; 536 sock_fd = sv[0];
520 close (sv[1]); 537 close (sv[1]);
521 fcntl (sock_fd, F_SETFD, FD_CLOEXEC); 538 fcntl (sock_fd, F_SETFD, FD_CLOEXEC);
522 } 539 }
523 else 540 else
524 { 541 {
525 // server, pty-helper 542 // server, pty-helper
526 sock_fd = sv[1]; 543 sock_fd = sv[1];
527 544
545 chdir ("/");
546
528 for (int fd = 0; fd < 1023; fd++) 547 for (int fd = 0; fd < 1023; fd++)
529 if (fd != sock_fd) 548 if (fd != sock_fd)
530 close (fd); 549 close (fd);
531 550
532 serve (); 551 serve ();
… …
534 } 553 }
535} 554}
536 555
537#endif 556#endif
538 557
539// a "factory" *g*
540rxvt_ptytty * 558ptytty *
541rxvt_new_ptytty () 559ptytty::create ()
542{ 560{
543#if PTYTTY_HELPER 561#if PTYTTY_HELPER
544 if (pid > 0) 562 if (helper_pid && getpid () == owner_pid)
545 // use helper process 563 // use helper process
546 return new rxvt_ptytty_proxy; 564 return new ptytty_proxy;
547 else 565 else
548#endif 566#endif
549 return new rxvt_ptytty_unix; 567 return new ptytty_unix;
550} 568}
551 569
552/*----------------------- 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
553 586
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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