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Comparing libptytty/src/ptytty.C (file contents):
Revision 1.9 by root, Sun Jan 22 03:49:41 2006 UTC vs.
Revision 1.16 by root, Mon Jan 23 11:22:34 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.
… …
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}
… …
370 } 371 }
371 372
372 return true; 373 return true;
373} 374}
374 375
376/////////////////////////////////////////////////////////////////////////////
377// helper/proxy support
378
375#if PTYTTY_HELPER 379#if PTYTTY_HELPER
376 380
377static int sock_fd = -1; 381static int sock_fd = -1;
378static int helper_pid, owner_pid; 382static int helper_pid, owner_pid;
379 383
… …
411 cmd.type = command::get; 415 cmd.type = command::get;
412 416
413 write (sock_fd, &cmd, sizeof (cmd)); 417 write (sock_fd, &cmd, sizeof (cmd));
414 418
415 if (read (sock_fd, &id, sizeof (id)) != sizeof (id)) 419 if (read (sock_fd, &id, sizeof (id)) != sizeof (id))
416 fatal ("protocol error while creating pty using helper process, aborting.\n"); 420 ptytty_fatal ("protocol error while creating pty using helper process, aborting.\n");
417 421
418 if (!id) 422 if (!id)
419 return false; 423 return false;
420 424
421 if ((pty = recv_fd (sock_fd)) < 0 425 if ((pty = recv_fd (sock_fd)) < 0
422 || (tty = recv_fd (sock_fd)) < 0) 426 || (tty = recv_fd (sock_fd)) < 0)
423 fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n"); 427 ptytty_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n");
424 428
425 return true; 429 return true;
426} 430}
427 431
428void 432void
… …
481 } 485 }
482 } 486 }
483 else if (cmd.type == command::login) 487 else if (cmd.type == command::login)
484 { 488 {
485#if UTMP_SUPPORT 489#if UTMP_SUPPORT
486 if (find (ptys.begin (), ptys.end (), cmd.id)) 490 if (find (ptys.begin (), ptys.end (), cmd.id) != ptys.end ())
487 { 491 {
488 cmd.hostname[sizeof (cmd.hostname) - 1] = 0; 492 cmd.hostname[sizeof (cmd.hostname) - 1] = 0;
489 cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname); 493 cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname);
490 } 494 }
491#endif 495#endif
… …
520 owner_pid = pid; 524 owner_pid = pid;
521 525
522 int sv[2]; 526 int sv[2];
523 527
524 if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv)) 528 if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv))
525 fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n"); 529 ptytty_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n");
526 530
527 helper_pid = fork (); 531 helper_pid = fork ();
528 532
529 if (helper_pid < 0) 533 if (helper_pid < 0)
530 fatal ("could not create pty/sessiondb helper process, aborting.\n"); 534 ptytty_fatal ("could not create pty/sessiondb helper process, aborting.\n");
531 535
532 if (helper_pid) 536 if (helper_pid)
533 { 537 {
534 // client, process 538 // client, process
535 sock_fd = sv[0]; 539 sock_fd = sv[0];
… …
564 else 568 else
565#endif 569#endif
566 return new ptytty_unix; 570 return new ptytty_unix;
567} 571}
568 572
573void
574ptytty::init ()
575{
576 uid_t uid = getuid ();
577 gid_t gid = getgid ();
578
579 // before doing anything else, check for setuid/setgid operation,
580 // start the helper process and drop privileges
581 if (uid != geteuid ()
582 || gid != getegid ())
583 {
584#if PTYTTY_HELPER
585 use_helper ();
586#else
587 ptytty_warn ("running setuid/setgid without pty helper compiled in, continuing unprivileged.\n");
588#endif
569 589
590 drop_privileges ();
591 }
592}
593
594void
595ptytty::drop_privileges ()
596{
597 uid_t uid = getuid ();
598 gid_t gid = getgid ();
599
600 // drop privileges
601#if HAVE_SETRESUID
602 setresgid (gid, gid, gid);
603 setresuid (uid, uid, uid);
604#elif HAVE_SETREUID
605 setregid (gid, gid);
606 setreuid (uid, uid);
607#elif HAVE_SETUID
608 setgid (gid);
609 setuid (uid);
610#endif
611
612 if (uid != geteuid ()
613 || gid != getegid ())
614 ptytty_fatal ("unable to drop privileges, aborting.\n");
615}
616
617/////////////////////////////////////////////////////////////////////////////
618// C API
619
620#ifndef NO_C_API
621
622#define DEFINE_METHOD(retval, name, args1, args2) \
623extern "C" retval ptytty_ ## name args1 \
624{ return ((struct ptytty *)ptytty)->name args2; }
625
626DEFINE_METHOD(int,pty,(void *ptytty),)
627DEFINE_METHOD(int,tty,(void *ptytty),)
628DEFINE_METHOD(int,get,(void *ptytty),())
629DEFINE_METHOD(void,login,(void *ptytty, int cmd_pid, bool login_shell, const char *hostname),(cmd_pid,login_shell,hostname))
630
631DEFINE_METHOD(void,close_tty,(void *ptytty),())
632DEFINE_METHOD(int,make_controlling_tty,(void *ptytty),())
633DEFINE_METHOD(void,set_utf8_mode,(void *ptytty, int on),(on))
634
635#define DEFINE_STATIC(retval, name, args) \
636extern "C" retval ptytty_ ## name args \
637{ return ptytty::name args; }
638
639DEFINE_STATIC(void,drop_privileges,())
640DEFINE_STATIC(void,use_helper,())
641
642DEFINE_STATIC(void,init,())
643DEFINE_STATIC(void *,create,())
644
645void ptytty_delete (void *ptytty)
646{
647 delete (struct ptytty *)ptytty;
648}
649
650// send_fd, recv_fd not exposed
651
652#endif

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