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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#pragma weak _signal = signal
#pragma weak _sighold = sighold
#pragma weak _sigrelse = sigrelse
#pragma weak _sigignore = sigignore
#pragma weak _sigset = sigset
#include "lint.h"
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <wait.h>
/*
* Check for valid signal number as per SVID.
*/
#define CHECK_SIG(s, code) \
if ((s) <= 0 || (s) >= NSIG || (s) == SIGKILL || (s) == SIGSTOP) { \
errno = EINVAL; \
return (code); \
}
/*
* Equivalent to stopdefault set in the kernel implementation (sig.c).
*/
#define STOPDEFAULT(s) \
((s) == SIGSTOP || (s) == SIGTSTP || (s) == SIGTTOU || (s) == SIGTTIN)
/*
* SVr3.x signal compatibility routines. They are now
* implemented as library routines instead of system
* calls.
*/
void(*
signal(int sig, void(*func)(int)))(int)
{
struct sigaction nact;
struct sigaction oact;
CHECK_SIG(sig, SIG_ERR);
nact.sa_handler = func;
nact.sa_flags = SA_RESETHAND|SA_NODEFER;
(void) sigemptyset(&nact.sa_mask);
/*
* Pay special attention if sig is SIGCHLD and
* the disposition is SIG_IGN, per sysV signal man page.
*/
if (sig == SIGCHLD) {
nact.sa_flags |= SA_NOCLDSTOP;
if (func == SIG_IGN)
nact.sa_flags |= SA_NOCLDWAIT;
}
if (STOPDEFAULT(sig))
nact.sa_flags |= SA_RESTART;
if (sigaction(sig, &nact, &oact) < 0)
return (SIG_ERR);
return (oact.sa_handler);
}
int
sighold(int sig)
{
sigset_t set;
CHECK_SIG(sig, -1);
/*
* errno set on failure by either sigaddset or sigprocmask.
*/
(void) sigemptyset(&set);
if (sigaddset(&set, sig) < 0)
return (-1);
return (sigprocmask(SIG_BLOCK, &set, (sigset_t *)0));
}
int
sigrelse(int sig)
{
sigset_t set;
CHECK_SIG(sig, -1);
/*
* errno set on failure by either sigaddset or sigprocmask.
*/
(void) sigemptyset(&set);
if (sigaddset(&set, sig) < 0)
return (-1);
return (sigprocmask(SIG_UNBLOCK, &set, (sigset_t *)0));
}
int
sigignore(int sig)
{
struct sigaction act;
sigset_t set;
CHECK_SIG(sig, -1);
act.sa_handler = SIG_IGN;
act.sa_flags = 0;
(void) sigemptyset(&act.sa_mask);
/*
* Pay special attention if sig is SIGCHLD and
* the disposition is SIG_IGN, per sysV signal man page.
*/
if (sig == SIGCHLD) {
act.sa_flags |= SA_NOCLDSTOP;
act.sa_flags |= SA_NOCLDWAIT;
}
if (STOPDEFAULT(sig))
act.sa_flags |= SA_RESTART;
if (sigaction(sig, &act, (struct sigaction *)0) < 0)
return (-1);
(void) sigemptyset(&set);
if (sigaddset(&set, sig) < 0)
return (-1);
return (sigprocmask(SIG_UNBLOCK, &set, (sigset_t *)0));
}
int
__sigpause(int sig)
{
sigset_t set;
int rval;
CHECK_SIG(sig, -1);
/*
* sigpause() is defined to unblock the signal
* and not block it again on return.
* sigsuspend() restores the original signal set,
* so we have to unblock sig overtly.
*/
(void) sigprocmask(0, (sigset_t *)0, &set);
if (sigdelset(&set, sig) < 0)
return (-1);
rval = sigsuspend(&set);
(void) sigrelse(sig);
return (rval);
}
void(*
sigset(int sig, void(*func)(int)))(int)
{
struct sigaction nact;
struct sigaction oact;
sigset_t nset;
sigset_t oset;
int code;
CHECK_SIG(sig, SIG_ERR);
(void) sigemptyset(&nset);
if (sigaddset(&nset, sig) < 0)
return (SIG_ERR);
if (func == SIG_HOLD) {
if (sigprocmask(SIG_BLOCK, &nset, &oset) < 0)
return (SIG_ERR);
if (sigaction(sig, (struct sigaction *)0, &oact) < 0)
return (SIG_ERR);
} else {
nact.sa_handler = func;
nact.sa_flags = 0;
(void) sigemptyset(&nact.sa_mask);
/*
* Pay special attention if sig is SIGCHLD and
* the disposition is SIG_IGN, per sysV signal man page.
*/
if (sig == SIGCHLD) {
nact.sa_flags |= SA_NOCLDSTOP;
if (func == SIG_IGN)
nact.sa_flags |= SA_NOCLDWAIT;
}
if (STOPDEFAULT(sig))
nact.sa_flags |= SA_RESTART;
if (sigaction(sig, &nact, &oact) < 0)
return (SIG_ERR);
if (sigprocmask(SIG_UNBLOCK, &nset, &oset) < 0)
return (SIG_ERR);
}
if ((code = sigismember(&oset, sig)) < 0)
return (SIG_ERR);
else if (code == 1)
return (SIG_HOLD);
return (oact.sa_handler);
}
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