| /* Copyright (C) 1998-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <errno.h> |
| #define __need_NULL |
| #include <stddef.h> |
| #include <signal.h> |
| #include <string.h> /* For the real memset prototype. */ |
| #include <sigsetops.h> |
| |
| /* Set the disposition for SIG. */ |
| __sighandler_t |
| sigset (int sig, __sighandler_t disp) |
| { |
| struct sigaction act; |
| struct sigaction oact; |
| sigset_t set; |
| sigset_t oset; |
| |
| /* Check signal extents to protect __sigismember. */ |
| if (disp == SIG_ERR || sig < 1 || sig >= NSIG) |
| { |
| __set_errno (EINVAL); |
| return SIG_ERR; |
| } |
| |
| __sigemptyset (&set); |
| __sigaddset (&set, sig); |
| |
| if (disp == SIG_HOLD) |
| { |
| /* Add the signal to the current signal mask. */ |
| if (__sigprocmask (SIG_BLOCK, &set, &oset) < 0) |
| return SIG_ERR; |
| |
| /* If the signal was already blocked signal this to the caller. */ |
| if (__sigismember (&oset, sig)) |
| return SIG_HOLD; |
| |
| /* We need to determine whether a specific handler is installed. */ |
| if (__sigaction (sig, NULL, &oact) < 0) |
| return SIG_ERR; |
| |
| return oact.sa_handler; |
| } |
| else |
| { |
| act.sa_handler = disp; |
| __sigemptyset (&act.sa_mask); |
| act.sa_flags = 0; |
| if (__sigaction (sig, &act, &oact) < 0) |
| return SIG_ERR; |
| |
| /* Remove the signal from the current signal mask. */ |
| if (__sigprocmask (SIG_UNBLOCK, &set, &oset) < 0) |
| return SIG_ERR; |
| |
| /* If the signal was already blocked return SIG_HOLD. */ |
| return __sigismember (&oset, sig) ? SIG_HOLD : oact.sa_handler; |
| } |
| } |