Fix assertion when handling DSTs during auditing.
[glibc.git] / termios / tcgetsid.c
blob8d97a944bff03c143bfc166f159af85b062d40f1
1 /* Copyright (C) 1997, 1999 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17 02111-1307 USA. */
19 #include <errno.h>
20 #include <termios.h>
21 #include <sys/ioctl.h>
22 #include <sys/types.h>
23 #include <unistd.h>
25 /* Return the session ID of FD. */
26 pid_t
27 tcgetsid (fd)
28 int fd;
30 pid_t pgrp;
31 pid_t sid;
32 #ifdef TIOCGSID
33 static int tiocgsid_does_not_work;
35 if (! tiocgsid_does_not_work)
37 int serrno = errno;
38 int sid;
40 if (__ioctl (fd, TIOCGSID, &sid) < 0)
42 if (errno == EINVAL)
44 tiocgsid_does_not_work = 1;
45 __set_errno (serrno);
47 else
48 return (pid_t) -1;
50 else
51 return (pid_t) sid;
53 #endif
55 pgrp = tcgetpgrp (fd);
56 if (pgrp == -1)
57 return (pid_t) -1;
59 sid = getsid (pgrp);
60 if (sid == -1 && errno == ESRCH)
61 __set_errno (ENOTTY);
63 return sid;