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, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
23 /* All Rights Reserved */
24
25 #include "signal.h"
26
27 #include "lpadmin.h"
28
29 static int trapping = -1; /* -1 means first time */
30
31 static
32 #ifdef SIGPOLL
33 void
34 #else
35 int
36 #endif
37 (*old_sighup)(),
38 (*old_sigint)(),
39 (*old_sigquit)(),
40 (*old_sigterm)();
41
42 /**
43 ** catch() - CLEAN UP AFTER SIGNAL
44 **/
45
46 static void
catch(int sig __unused)47 catch (int sig __unused)
48 {
49 (void)signal (SIGHUP, SIG_IGN);
50 (void)signal (SIGINT, SIG_IGN);
51 (void)signal (SIGQUIT, SIG_IGN);
52 (void)signal (SIGTERM, SIG_IGN);
53 done (1);
54 }
55
56 /**
57 ** trap_signals() - SET SIGNALS TO BE CAUGHT FOR CLEAN EXIT
58 **/
59
trap_signals()60 void trap_signals ()
61 {
62 switch (trapping) {
63
64 case -1: /* first time */
65
66 #define SETSIG(SIG) \
67 if (signal(SIG, SIG_IGN) != SIG_IGN) \
68 signal (SIG, catch);
69
70 SETSIG (SIGHUP);
71 SETSIG (SIGINT);
72 SETSIG (SIGQUIT);
73 SETSIG (SIGTERM);
74 break;
75
76 case 0: /* currently ignoring */
77 signal (SIGHUP, old_sighup);
78 signal (SIGINT, old_sigint);
79 signal (SIGQUIT, old_sigquit);
80 signal (SIGTERM, old_sigterm);
81 trapping = 1;
82 break;
83
84 case 1: /* already trapping */
85 break;
86
87 }
88 return;
89 }
90
91 /**
92 ** ignore_signals() - SET SIGNALS TO BE IGNORED FOR CRITICAL SECTIONS
93 **/
94
ignore_signals()95 void ignore_signals ()
96 {
97 switch (trapping) {
98
99 case -1: /* first time */
100 trap_signals ();
101 /*fall through*/
102
103 case 1: /* currently trapping */
104 old_sighup = signal(SIGHUP, SIG_IGN);
105 old_sigint = signal(SIGINT, SIG_IGN);
106 old_sigquit = signal(SIGQUIT, SIG_IGN);
107 old_sigterm = signal(SIGTERM, SIG_IGN);
108 trapping = 0;
109 break;
110
111 case 0: /* already ignoring */
112 break;
113
114 }
115 return;
116 }
117