1 /*-
2 * Copyright (c) 1997 - 1999, 2001 Brian Somers <brian@Awfulhak.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/usr.sbin/ppp/sig.c,v 1.15.2.1 2002/09/01 02:12:32 brian Exp $
27 * $DragonFly: src/usr.sbin/ppp/sig.c,v 1.4 2005/11/24 23:42:54 swildner Exp $
28 */
29
30 #include <sys/types.h>
31
32 #include <signal.h>
33
34 #include "log.h"
35 #include "sig.h"
36
37 static int caused[NSIG]; /* An array of pending signals */
38 static int necessary; /* Anything set ? */
39 static sig_type handler[NSIG]; /* all start at SIG_DFL */
40
41
42 /*
43 * Record a signal in the "caused" array
44 *
45 * This function is the only thing actually called in signal context. It
46 * records that a signal has been caused and that sig_Handle() should be
47 * called (in non-signal context) as soon as possible to process that
48 * signal.
49 */
50 static void
signal_recorder(int sig)51 signal_recorder(int sig)
52 {
53 caused[sig - 1]++;
54 necessary = 1;
55 }
56
57
58 /*
59 * Set up signal_recorder to handle the given sig and record ``fn'' as
60 * the function to ultimately call in sig_Handle(). ``fn'' will not be
61 * called in signal context (as sig_Handle() is not called in signal
62 * context).
63 */
64 sig_type
sig_signal(int sig,sig_type fn)65 sig_signal(int sig, sig_type fn)
66 {
67 sig_type Result;
68
69 if (sig <= 0 || sig >= NSIG) {
70 /* Oops - we must be a bit out of date (too many sigs ?) */
71 log_Printf(LogALERT, "Eeek! %s:%d: I must be out of date!\n",
72 __FILE__, __LINE__);
73 return signal(sig, fn);
74 }
75 Result = handler[sig - 1];
76 if (fn == SIG_DFL || fn == SIG_IGN) {
77 signal(sig, fn);
78 handler[sig - 1] = (sig_type) 0;
79 } else {
80 handler[sig - 1] = fn;
81 signal(sig, signal_recorder);
82 }
83 caused[sig - 1] = 0;
84 return Result;
85 }
86
87
88 /*
89 * Call the handlers for any pending signals
90 *
91 * This function is called from a non-signal context - in fact, it's
92 * called every time select() in DoLoop() returns - just in case
93 * select() returned due to a signal being recorded by signal_recorder().
94 */
95 int
sig_Handle(void)96 sig_Handle(void)
97 {
98 int sig;
99 int got;
100 int result;
101
102 result = 0;
103 if (necessary) {
104 /* We've *probably* got something in `caused' set */
105 necessary = 0;
106 /* `necessary' might go back to 1 while we're in here.... */
107 do {
108 got = 0;
109 for (sig = 0; sig < NSIG; sig++)
110 if (caused[sig]) {
111 caused[sig]--;
112 got++;
113 result++;
114 (*handler[sig])(sig + 1);
115 }
116 } while (got);
117 }
118
119 return result;
120 }
121