ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/libptytty/src/ptytty.C
(Generate patch)

Comparing libptytty/src/ptytty.C (file contents):
Revision 1.8 by root, Sun Jan 22 00:58:18 2006 UTC vs.
Revision 1.19 by root, Mon Jan 23 11:36:01 2006 UTC

… …
6 *----------------------------------------------------------------------* 6 *----------------------------------------------------------------------*
7 * 7 *
8 * All portions of code are copyright by their respective author/s. 8 * All portions of code are copyright by their respective author/s.
9 * 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> 10 * Copyright (c) 2004-2006 Marc Lehmann <pcg@goof.com>
11 * Copyright (c) 2006 Emanuele Giaquinta <e.giaquinta@glauco.it>
11 * 12 *
12 * 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
13 * 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
14 * the Free Software Foundation; either version 2 of the License, or 15 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version. 16 * (at your option) any later version.
… …
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 *---------------------------------------------------------------------*/ 26 *---------------------------------------------------------------------*/
26 27
27#include "../config.h" 28#include "../config.h"
28 29
29#include "fdpass.h"
30#include "ptytty.h" 30#include "ptytty.h"
31 31
32#include <cstdlib> 32#include <cstdlib>
33#include <cstring> 33#include <cstring>
34#include <csignal>
34 35
35#include <sys/types.h> 36#include <sys/types.h>
36#include <sys/socket.h> 37#include <sys/socket.h>
37#include <unistd.h> 38#include <unistd.h>
38#include <fcntl.h> 39#include <fcntl.h>
… …
235 236
236 ioctl (fd_tty, TIOCSCTTY, NULL); 237 ioctl (fd_tty, TIOCSCTTY, NULL);
237 238
238 int fd = open ("/dev/tty", O_WRONLY); 239 int fd = open ("/dev/tty", O_WRONLY);
239 if (fd < 0) 240 if (fd < 0)
240 return -1; /* fatal */ 241 return -1; /* fatal */
241 242
242 close (fd); 243 close (fd);
243 244
244 return 0; 245 return 0;
245} 246}
… …
371 } 372 }
372 373
373 return true; 374 return true;
374} 375}
375 376
377/////////////////////////////////////////////////////////////////////////////
378// helper/proxy support
379
376#if PTYTTY_HELPER 380#if PTYTTY_HELPER
377 381
378static int sock_fd; 382static int sock_fd = -1, lock_fd = -1;
379static int pid; 383static int helper_pid, owner_pid;
380 384
381struct command 385struct command
382{ 386{
383 enum { get, login, destroy } type; 387 enum { get, login, destroy } type;
384 388
… …
412 cmd.type = command::get; 416 cmd.type = command::get;
413 417
414 write (sock_fd, &cmd, sizeof (cmd)); 418 write (sock_fd, &cmd, sizeof (cmd));
415 419
416 if (read (sock_fd, &id, sizeof (id)) != sizeof (id)) 420 if (read (sock_fd, &id, sizeof (id)) != sizeof (id))
417 fatal ("protocol error while creating pty using helper process, aborting.\n"); 421 ptytty_fatal ("protocol error while creating pty using helper process, aborting.\n");
418 422
419 if (!id) 423 if (!id)
420 return false; 424 return false;
421 425
422 if ((pty = ptytty_recv_fd (sock_fd)) < 0 426 if ((pty = recv_fd (sock_fd)) < 0
423 || (tty = ptytty_recv_fd (sock_fd)) < 0) 427 || (tty = recv_fd (sock_fd)) < 0)
424 fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n"); 428 ptytty_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n");
425 429
426 return true; 430 return true;
427} 431}
428 432
429void 433void
… …
469 if (cmd.id->get ()) 473 if (cmd.id->get ())
470 { 474 {
471 write (sock_fd, &cmd.id, sizeof (cmd.id)); 475 write (sock_fd, &cmd.id, sizeof (cmd.id));
472 ptys.push_back (cmd.id); 476 ptys.push_back (cmd.id);
473 477
474 ptytty_send_fd (sock_fd, cmd.id->pty); 478 ptytty::send_fd (sock_fd, cmd.id->pty);
475 ptytty_send_fd (sock_fd, cmd.id->tty); 479 ptytty::send_fd (sock_fd, cmd.id->tty);
476 } 480 }
477 else 481 else
478 { 482 {
479 delete cmd.id; 483 delete cmd.id;
480 cmd.id = 0; 484 cmd.id = 0;
… …
482 } 486 }
483 } 487 }
484 else if (cmd.type == command::login) 488 else if (cmd.type == command::login)
485 { 489 {
486#if UTMP_SUPPORT 490#if UTMP_SUPPORT
487 if (find (ptys.begin (), ptys.end (), cmd.id)) 491 if (find (ptys.begin (), ptys.end (), cmd.id) != ptys.end ())
488 { 492 {
489 cmd.hostname[sizeof (cmd.hostname) - 1] = 0; 493 cmd.hostname[sizeof (cmd.hostname) - 1] = 0;
490 cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname); 494 cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname);
491 } 495 }
492#endif 496#endif
493 } 497 }
494 else if (cmd.type == command::destroy) 498 else if (cmd.type == command::destroy)
495 { 499 {
496 ptytty **pty = find (ptys.begin (), ptys.end (), cmd.id); 500 vector<ptytty *>::iterator pty = find (ptys.begin (), ptys.end (), cmd.id);
497 501
498 if (pty) 502 if (pty != ptys.end ())
499 { 503 {
500 delete *pty; 504 delete *pty;
501 ptys.erase (pty); 505 ptys.erase (pty);
502 } 506 }
503 } 507 }
504 else 508 else
505 break; 509 break;
506 } 510 }
507 511
508 // destroy all ptys 512 // destroy all ptys
509 for (ptytty **i = ptys.end (); i-- > ptys.begin (); ) 513 for (vector<ptytty *>::iterator i = ptys.end (); i-- > ptys.begin (); )
510 delete *i; 514 delete *i;
511} 515}
512 516
513void ptytty_server () 517void
518ptytty::use_helper ()
514{ 519{
520 int pid = getpid ();
521
522 if (sock_fd >= 0 && pid == owner_pid)
523 return;
524
525 owner_pid = pid;
526
515 int sv[2]; 527 int sv[2];
516 528
517 if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv)) 529 if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv))
518 fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n"); 530 ptytty_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");
519 531
532#ifdef PTYTTY_REENTRANT
533 int lv[2];
534
535 if (socketpair (AF_UNIX, SOCK_STREAM, 0, lv))
536 ptytty_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");
537#endif
538
520 pid = fork (); 539 helper_pid = fork ();
521 540
522 if (pid < 0) 541 if (helper_pid < 0)
523 fatal ("could not create pty/sessiondb helper process, aborting.\n"); 542 ptytty_fatal ("could not create pty/sessiondb helper process, aborting.\n");
524 543
525 if (pid) 544 if (helper_pid)
526 { 545 {
527 // client, process 546 // client, process
528 sock_fd = sv[0]; 547 sock_fd = sv[0];
529 close (sv[1]); 548 close (sv[1]);
530 fcntl (sock_fd, F_SETFD, FD_CLOEXEC); 549 fcntl (sock_fd, F_SETFD, FD_CLOEXEC);
550#ifdef PTYTTY_REENTRANT
551 lock_fd = lv[0];
552 close (lv[1]);
553 fcntl (lock_fd, F_SETFD, FD_CLOEXEC);
554#endif
531 } 555 }
532 else 556 else
533 { 557 {
534 // server, pty-helper 558 // server, pty-helper
535 sock_fd = sv[1]; 559 sock_fd = sv[1];
560#ifdef PTYTTY_REENTRANT
561 lock_fd = lv[1];
562#endif
563
564 chdir ("/");
565
566 signal (SIGHUP, SIG_IGN);
567 signal (SIGTERM, SIG_IGN);
568 signal (SIGINT, SIG_IGN);
569 signal (SIGPIPE, SIG_IGN);
536 570
537 for (int fd = 0; fd < 1023; fd++) 571 for (int fd = 0; fd < 1023; fd++)
538 if (fd != sock_fd) 572 if (fd != sock_fd && fd != lock_fd)
539 close (fd); 573 close (fd);
540 574
541 serve (); 575 serve ();
542 _exit (EXIT_SUCCESS); 576 _exit (EXIT_SUCCESS);
543 } 577 }
544} 578}
545 579
546#endif 580#endif
547 581
548// a "factory" *g*
549ptytty * 582ptytty *
550new_ptytty () 583ptytty::create ()
551{ 584{
552#if PTYTTY_HELPER 585#if PTYTTY_HELPER
553 if (pid > 0) 586 if (helper_pid && getpid () == owner_pid)
554 // use helper process 587 // use helper process
555 return new ptytty_proxy; 588 return new ptytty_proxy;
556 else 589 else
557#endif 590#endif
558 return new ptytty_unix; 591 return new ptytty_unix;
559} 592}
560 593
561/*----------------------- end-of-file (C source) -----------------------*/ 594void
595ptytty::init ()
596{
597 uid_t uid = getuid ();
598 gid_t gid = getgid ();
599
600 // before doing anything else, check for setuid/setgid operation,
601 // start the helper process and drop privileges
602 if (uid != geteuid ()
603 || gid != getegid ())
604 {
605#if PTYTTY_HELPER
606 use_helper ();
607#else
608 ptytty_warn ("running setuid/setgid without pty helper compiled in, continuing unprivileged.\n");
609#endif
562 610
611 drop_privileges ();
612 }
613}
614
615void
616ptytty::drop_privileges ()
617{
618 uid_t uid = getuid ();
619 gid_t gid = getgid ();
620
621 // drop privileges
622#if HAVE_SETRESUID
623 setresgid (gid, gid, gid);
624 setresuid (uid, uid, uid);
625#elif HAVE_SETREUID
626 setregid (gid, gid);
627 setreuid (uid, uid);
628#elif HAVE_SETUID
629 setgid (gid);
630 setuid (uid);
631#endif
632
633 if (uid != geteuid ()
634 || gid != getegid ())
635 ptytty_fatal ("unable to drop privileges, aborting.\n");
636}
637
638/////////////////////////////////////////////////////////////////////////////
639// C API
640
641#ifndef NO_C_API
642
643#define DEFINE_METHOD(retval, name, args1, args2) \
644extern "C" retval ptytty_ ## name args1 \
645{ return ((struct ptytty *)ptytty)->name args2; }
646
647DEFINE_METHOD(int,pty,(void *ptytty),)
648DEFINE_METHOD(int,tty,(void *ptytty),)
649DEFINE_METHOD(int,get,(void *ptytty),())
650DEFINE_METHOD(void,login,(void *ptytty, int cmd_pid, bool login_shell, const char *hostname),(cmd_pid,login_shell,hostname))
651
652DEFINE_METHOD(void,close_tty,(void *ptytty),())
653DEFINE_METHOD(int,make_controlling_tty,(void *ptytty),())
654DEFINE_METHOD(void,set_utf8_mode,(void *ptytty, int on),(on))
655
656#define DEFINE_STATIC(retval, name, args) \
657extern "C" retval ptytty_ ## name args \
658{ return ptytty::name args; }
659
660DEFINE_STATIC(void,drop_privileges,())
661DEFINE_STATIC(void,use_helper,())
662DEFINE_STATIC(void,init,())
663
664DEFINE_STATIC(void *,create,())
665
666void ptytty_delete (void *ptytty)
667{
668 delete (struct ptytty *)ptytty;
669}
670
671// send_fd, recv_fd not exposed
672
673#endif

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines