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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 1.56 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>
… …
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"
28
25#include "rxvt.h" 29#include "ptytty.h"
26 30
27#include <cstdlib> 31#include <cstdlib>
28#include <cstring> 32#include <cstring>
29 33
30#include <sys/types.h> 34#include <sys/types.h>
… …
51#ifdef TTY_GID_SUPPORT 55#ifdef TTY_GID_SUPPORT
52#include <grp.h> 56#include <grp.h>
53#endif 57#endif
54 58
55#include <cstdio> 59#include <cstdio>
56
57#include "rxvtutil.h"
58#include "fdpass.h"
59#include "ptytty.h"
60 60
61///////////////////////////////////////////////////////////////////////////// 61/////////////////////////////////////////////////////////////////////////////
62 62
63/* ------------------------------------------------------------------------- * 63/* ------------------------------------------------------------------------- *
64 * GET PSEUDO TELETYPE - MASTER AND SLAVE * 64 * GET PSEUDO TELETYPE - MASTER AND SLAVE *
… …
234 234
235 ioctl (fd_tty, TIOCSCTTY, NULL); 235 ioctl (fd_tty, TIOCSCTTY, NULL);
236 236
237 int fd = open ("/dev/tty", O_WRONLY); 237 int fd = open ("/dev/tty", O_WRONLY);
238 if (fd < 0) 238 if (fd < 0)
239 return -1; /* fatal */ 239 return -1; /* fatal */
240 240
241 close (fd); 241 close (fd);
242 242
243 return 0; 243 return 0;
244} 244}
245 245
246void 246void
247rxvt_ptytty::close_tty () 247ptytty::close_tty ()
248{ 248{
249 if (tty < 0) 249 if (tty < 0)
250 return; 250 return;
251 251
252 close (tty); 252 close (tty);
253 tty = -1; 253 tty = -1;
254} 254}
255 255
256bool 256bool
257rxvt_ptytty::make_controlling_tty () 257ptytty::make_controlling_tty ()
258{ 258{
259 return control_tty (tty) >= 0; 259 return control_tty (tty) >= 0;
260} 260}
261 261
262void 262void
263rxvt_ptytty::set_utf8_mode (bool on) 263ptytty::set_utf8_mode (bool on)
264{ 264{
265#ifdef IUTF8 265#ifdef IUTF8
266 if (pty < 0) 266 if (pty < 0)
267 return; 267 return;
268 268
… …
307 gid = 0; 307 gid = 0;
308 } 308 }
309 } 309 }
310} ttyconf; 310} ttyconf;
311 311
312rxvt_ptytty_unix::rxvt_ptytty_unix () 312ptytty_unix::ptytty_unix ()
313{ 313{
314 name = 0; 314 name = 0;
315#if UTMP_SUPPORT 315#if UTMP_SUPPORT
316 cmd_pid = 0; 316 cmd_pid = 0;
317#endif 317#endif
318} 318}
319 319
320rxvt_ptytty_unix::~rxvt_ptytty_unix () 320ptytty_unix::~ptytty_unix ()
321{ 321{
322#if UTMP_SUPPORT 322#if UTMP_SUPPORT
323 logout (); 323 logout ();
324#endif 324#endif
325 put (); 325 put ();
326} 326}
327 327
328void 328void
329rxvt_ptytty_unix::put () 329ptytty_unix::put ()
330{ 330{
331 chmod (name, RESTORE_TTY_MODE); 331 chmod (name, RESTORE_TTY_MODE);
332 chown (name, 0, ttyconf.gid); 332 chown (name, 0, ttyconf.gid);
333 333
334 close_tty (); 334 close_tty ();
… …
341 pty = tty = -1; 341 pty = tty = -1;
342 name = 0; 342 name = 0;
343} 343}
344 344
345bool 345bool
346rxvt_ptytty_unix::get () 346ptytty_unix::get ()
347{ 347{
348 /* get master (pty) */ 348 /* get master (pty) */
349 if ((pty = get_pty (&tty, &name)) < 0) 349 if ((pty = get_pty (&tty, &name)) < 0)
350 return false; 350 return false;
351 351
… …
372 return true; 372 return true;
373} 373}
374 374
375#if PTYTTY_HELPER 375#if PTYTTY_HELPER
376 376
377static int sock_fd; 377static int sock_fd = -1;
378static int pid; 378static int helper_pid, owner_pid;
379 379
380struct command 380struct command
381{ 381{
382 enum { get, login, destroy } type; 382 enum { get, login, destroy } type;
383 383
384 rxvt_ptytty *id; 384 ptytty *id;
385 385
386 bool login_shell; 386 bool login_shell;
387 int cmd_pid; 387 int cmd_pid;
388 char hostname[512]; // arbitrary, but should be plenty 388 char hostname[512]; // arbitrary, but should be plenty
389}; 389};
390 390
391struct rxvt_ptytty_proxy : zero_initialized, rxvt_ptytty 391struct ptytty_proxy : ptytty
392{ 392{
393 rxvt_ptytty *id; 393 ptytty *id;
394 394
395 ptytty_proxy ()
396 : id(0)
397 {
398 }
399
395 ~rxvt_ptytty_proxy (); 400 ~ptytty_proxy ();
396 401
397 bool get (); 402 bool get ();
398 void login (int cmd_pid, bool login_shell, const char *hostname); 403 void login (int cmd_pid, bool login_shell, const char *hostname);
399}; 404};
400 405
401bool 406bool
402rxvt_ptytty_proxy::get () 407ptytty_proxy::get ()
403{ 408{
404 command cmd; 409 command cmd;
405 410
406 cmd.type = command::get; 411 cmd.type = command::get;
407 412
408 write (sock_fd, &cmd, sizeof (cmd)); 413 write (sock_fd, &cmd, sizeof (cmd));
409 414
410 if (read (sock_fd, &id, sizeof (id)) != sizeof (id)) 415 if (read (sock_fd, &id, sizeof (id)) != sizeof (id))
411 rxvt_fatal ("protocol error while creating pty using helper process, aborting.\n"); 416 ptytty_fatal ("protocol error while creating pty using helper process, aborting.\n");
412 417
413 if (!id) 418 if (!id)
414 return false; 419 return false;
415 420
416 if ((pty = rxvt_recv_fd (sock_fd)) < 0 421 if ((pty = recv_fd (sock_fd)) < 0
417 || (tty = rxvt_recv_fd (sock_fd)) < 0) 422 || (tty = recv_fd (sock_fd)) < 0)
418 rxvt_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n"); 423 ptytty_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n");
419 424
420 return true; 425 return true;
421} 426}
422 427
423void 428void
424rxvt_ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname) 429ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname)
425{ 430{
426 command cmd; 431 command cmd;
427 432
428 cmd.type = command::login; 433 cmd.type = command::login;
429 cmd.id = id; 434 cmd.id = id;
… …
432 strncpy (cmd.hostname, hostname, sizeof (cmd.hostname)); 437 strncpy (cmd.hostname, hostname, sizeof (cmd.hostname));
433 438
434 write (sock_fd, &cmd, sizeof (cmd)); 439 write (sock_fd, &cmd, sizeof (cmd));
435} 440}
436 441
437rxvt_ptytty_proxy::~rxvt_ptytty_proxy () 442ptytty_proxy::~ptytty_proxy ()
438{ 443{
444 if (id)
445 {
439 command cmd; 446 command cmd;
440 447
441 cmd.type = command::destroy; 448 cmd.type = command::destroy;
442 cmd.id = id; 449 cmd.id = id;
443 450
444 write (sock_fd, &cmd, sizeof (cmd)); 451 write (sock_fd, &cmd, sizeof (cmd));
452 }
445} 453}
446 454
447static 455static
448void serve () 456void serve ()
449{ 457{
450 command cmd; 458 command cmd;
451 vector<rxvt_ptytty *> ptys; 459 vector<ptytty *> ptys;
452 460
453 while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command)) 461 while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command))
454 { 462 {
455 if (cmd.type == command::get) 463 if (cmd.type == command::get)
456 { 464 {
457 // -> id ptyfd ttyfd 465 // -> id ptyfd ttyfd
458 cmd.id = new rxvt_ptytty_unix; 466 cmd.id = new ptytty_unix;
459 467
460 if (cmd.id->get ()) 468 if (cmd.id->get ())
461 { 469 {
462 write (sock_fd, &cmd.id, sizeof (cmd.id)); 470 write (sock_fd, &cmd.id, sizeof (cmd.id));
463 ptys.push_back (cmd.id); 471 ptys.push_back (cmd.id);
464 472
465 rxvt_send_fd (sock_fd, cmd.id->pty); 473 ptytty::send_fd (sock_fd, cmd.id->pty);
466 rxvt_send_fd (sock_fd, cmd.id->tty); 474 ptytty::send_fd (sock_fd, cmd.id->tty);
467 } 475 }
468 else 476 else
469 { 477 {
470 delete cmd.id; 478 delete cmd.id;
471 cmd.id = 0; 479 cmd.id = 0;
… …
482 } 490 }
483#endif 491#endif
484 } 492 }
485 else if (cmd.type == command::destroy) 493 else if (cmd.type == command::destroy)
486 { 494 {
487 rxvt_ptytty **pty = find (ptys.begin (), ptys.end (), cmd.id); 495 vector<ptytty *>::iterator pty = find (ptys.begin (), ptys.end (), cmd.id);
488 496
489 if (pty) 497 if (pty != ptys.end ())
490 { 498 {
491 delete *pty; 499 delete *pty;
492 ptys.erase (pty); 500 ptys.erase (pty);
493 } 501 }
494 } 502 }
495 else 503 else
496 break; 504 break;
497 } 505 }
498 506
499 // destroy all ptys 507 // destroy all ptys
500 for (rxvt_ptytty **i = ptys.end (); i-- > ptys.begin (); ) 508 for (vector<ptytty *>::iterator i = ptys.end (); i-- > ptys.begin (); )
501 delete *i; 509 delete *i;
502} 510}
503 511
504void rxvt_ptytty_server () 512void
513ptytty::use_helper ()
505{ 514{
515 int pid = getpid ();
516
517 if (sock_fd >= 0 && pid == owner_pid)
518 return;
519
520 owner_pid = pid;
521
506 int sv[2]; 522 int sv[2];
507 523
508 if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv)) 524 if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv))
509 rxvt_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n"); 525 ptytty_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");
510 526
511 pid = fork (); 527 helper_pid = fork ();
512 528
513 if (pid < 0) 529 if (helper_pid < 0)
514 rxvt_fatal ("could not create pty/sessiondb helper process, aborting.\n"); 530 ptytty_fatal ("could not create pty/sessiondb helper process, aborting.\n");
515 531
516 if (pid) 532 if (helper_pid)
517 { 533 {
518 // client, urxvt 534 // client, process
519 sock_fd = sv[0]; 535 sock_fd = sv[0];
520 close (sv[1]); 536 close (sv[1]);
521 fcntl (sock_fd, F_SETFD, FD_CLOEXEC); 537 fcntl (sock_fd, F_SETFD, FD_CLOEXEC);
522 } 538 }
523 else 539 else
524 { 540 {
525 // server, pty-helper 541 // server, pty-helper
526 sock_fd = sv[1]; 542 sock_fd = sv[1];
527 543
544 chdir ("/");
545
528 for (int fd = 0; fd < 1023; fd++) 546 for (int fd = 0; fd < 1023; fd++)
529 if (fd != sock_fd) 547 if (fd != sock_fd)
530 close (fd); 548 close (fd);
531 549
532 serve (); 550 serve ();
… …
534 } 552 }
535} 553}
536 554
537#endif 555#endif
538 556
539// a "factory" *g*
540rxvt_ptytty * 557ptytty *
541rxvt_new_ptytty () 558ptytty::create ()
542{ 559{
543#if PTYTTY_HELPER 560#if PTYTTY_HELPER
544 if (pid > 0) 561 if (helper_pid && getpid () == owner_pid)
545 // use helper process 562 // use helper process
546 return new rxvt_ptytty_proxy; 563 return new ptytty_proxy;
547 else 564 else
548#endif 565#endif
549 return new rxvt_ptytty_unix; 566 return new ptytty_unix;
550} 567}
551 568
552/*----------------------- end-of-file (C source) -----------------------*/ 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
553 585
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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