xref: /illumos-gate/usr/src/lib/libc/port/gen/ssignal.c (revision e616c49c963c6536f26b6d8888bc4bbb54716901)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	All Rights Reserved	*/
29 
30 /*
31  *	ssignal, gsignal: software signals
32  */
33 
34 #include "lint.h"
35 #include <sys/types.h>
36 #include <signal.h>
37 
38 /* Highest allowable user signal number */
39 #define	MAXSIGNUM	17
40 
41 /* Lowest allowable signal number (lowest user number is always 1) */
42 #define	MINSIG	(-4)
43 
44 /* Table of signal values */
45 static int (*sigs[MAXSIGNUM-MINSIG+1])(int);
46 
47 int (*
48 ssignal(int sig, int (*action)(int)))(int)
49 {
50 	int (*savefn)(int);
51 
52 	if (sig >= MINSIG && sig <= MAXSIGNUM) {
53 		savefn = sigs[sig-MINSIG];
54 		sigs[sig-MINSIG] = action;
55 	} else {
56 		savefn = (int(*)(int))(uintptr_t)SIG_DFL;
57 	}
58 
59 	return (savefn);
60 }
61 
62 int
63 gsignal(int sig)
64 {
65 	int (*sigfn)(int);
66 
67 	if (sig < MINSIG || sig > MAXSIGNUM ||
68 	    (sigfn = sigs[sig-MINSIG]) == (int(*)(int))(uintptr_t)SIG_DFL) {
69 		return (0);
70 	} else {
71 		if (sigfn == (int(*)(int))(uintptr_t)SIG_IGN) {
72 			return (1);
73 		} else {
74 			sigs[sig-MINSIG] = (int(*)(int))(uintptr_t)SIG_DFL;
75 			return ((*sigfn)(sig));
76 		}
77 	}
78 }
79