NetBSD/lib/libc/gen/sigset.c

103 lines
3.3 KiB
C

/* $NetBSD: sigset.c,v 1.1 2003/01/15 23:55:43 kleink Exp $ */
/*-
* Copyright (c) 2003 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Klaus Klein.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: sigset.c,v 1.1 2003/01/15 23:55:43 kleink Exp $");
#endif
#include "namespace.h"
#include <errno.h>
#include <signal.h>
#include <stddef.h>
sig_t
sigset(int sig, void (*disp)(int))
{
sigset_t set, oset;
struct sigaction sa, osa;
osa.sa_handler = SIG_ERR;
if (disp == SIG_HOLD) {
/* Add sig to current signal mask. */
if (sigemptyset(&set) != 0)
goto out;
if (sigaddset(&set, sig) != 0)
goto out;
if (sigprocmask(SIG_BLOCK, &set, &oset) != 0)
goto out;
if (sigismember(&oset, sig)) {
/* Had been masked before, return SIG_HOLD. */
osa.sa_handler = SIG_HOLD;
} else {
/* Return previous disposition. */
(void)sigaction(sig, NULL, &osa);
}
} else if (disp == SIG_ERR) {
errno = EINVAL;
} else {
/* Set up and install new disposition. */
sa.sa_handler = disp;
if (sigemptyset(&sa.sa_mask) != 0)
goto out;
sa.sa_flags = 0;
if (sigaction(sig, &sa, &osa) != 0) {
osa.sa_handler = SIG_ERR;
goto out;
}
/* Delete sig from current signal mask. */
if (sigemptyset(&set) != 0)
return (SIG_ERR);
if (sigaddset(&set, sig) != 0)
return (SIG_ERR);
if (sigprocmask(SIG_UNBLOCK, &set, &oset) != 0)
return (SIG_ERR);
/* If had been masked before, return SIG_HOLD. */
if (sigismember(&oset, sig))
osa.sa_handler = SIG_HOLD;
}
out:
return (osa.sa_handler);
}