xref: /freebsd/usr.sbin/ppp/sig.c (revision a8445737e740901f5f2c8d24c12ef7fc8b00134e)
1 /*-
2  * Copyright (c) 1997 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  *	$Id: sig.c,v 1.11.2.5 1998/05/01 19:25:56 brian Exp $
27  */
28 
29 #include <sys/types.h>
30 
31 #include <signal.h>
32 
33 #include "log.h"
34 #include "sig.h"
35 
36 static int caused[NSIG];	/* An array of pending signals */
37 static sig_type handler[NSIG];	/* all start at SIG_DFL */
38 
39 
40 /* Record a signal in the "caused" array */
41 
42 static void
43 signal_recorder(int sig)
44 {
45   caused[sig - 1]++;
46 }
47 
48 
49 /*
50  * Set up signal_recorder, and record handler as the function to ultimately
51  * call in handle_signal()
52 */
53 
54 sig_type
55 sig_signal(int sig, sig_type fn)
56 {
57   sig_type Result;
58 
59   if (sig <= 0 || sig > NSIG) {
60     /* Oops - we must be a bit out of date (too many sigs ?) */
61     log_Printf(LogALERT, "Eeek! %s:%d: I must be out of date!\n",
62 	      __FILE__, __LINE__);
63     return signal(sig, fn);
64   }
65   Result = handler[sig - 1];
66   if (fn == SIG_DFL || fn == SIG_IGN) {
67     signal(sig, fn);
68     handler[sig - 1] = (sig_type) 0;
69   } else {
70     handler[sig - 1] = fn;
71     signal(sig, signal_recorder);
72   }
73   caused[sig - 1] = 0;
74   return Result;
75 }
76 
77 
78 /* Call the handlers for any pending signals */
79 
80 void
81 sig_Handle()
82 {
83   int sig;
84   int got;
85 
86   do {
87     got = 0;
88     for (sig = 0; sig < NSIG; sig++)
89       if (caused[sig]) {
90 	caused[sig]--;
91 	got++;
92 	(*handler[sig]) (sig + 1);
93       }
94   } while (got);
95 }
96