xref: /freebsd/usr.sbin/ppp/sig.c (revision 4a0f765fbf09711e612e86fce8bb09ec43f482d9)
1 /*-
2  * Copyright (c) 1997
3  *	Brian Somers <brian@awfulhak.demon.co.uk>.  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  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  *
31  *  TODO:
32  *
33  */
34 
35 #include "sig.h"
36 #include <sys/types.h>
37 #include "mbuf.h"
38 #include "log.h"
39 
40 #define __MAXSIG (32)		/* Sizeof u_long: Make life convenient.... */
41 static u_long caused;				/* A mask of pending signals */
42 static __sighandler_t *handler[ __MAXSIG ];	/* all start at SIG_DFL */
43 
44 
45 /* Record a signal in the "caused" mask */
46 
47 static void signal_recorder(int sig) {
48     if (sig > 0 && sig <= __MAXSIG)
49         caused |= (1<<(sig-1));
50 }
51 
52 
53 /*
54     set up signal_recorder, and record handler as the function to ultimately
55     call in handle_signal()
56 */
57 
58 __sighandler_t *pending_signal(int sig,__sighandler_t *fn) {
59     __sighandler_t *Result;
60 
61     if (sig <= 0 || sig > __MAXSIG) {
62 	/* Oops - we must be a bit out of date (too many sigs ?) */
63         logprintf("Eeek! %s:%s: I must be out of date!\n",__FILE__,__LINE__);
64         return signal(sig,fn);
65     }
66 
67     Result = handler[sig-1];
68     if (fn == SIG_DFL || fn == SIG_IGN) {
69         handler[sig-1] = (__sighandler_t *)0;
70         signal(sig,fn);
71     } else {
72         handler[sig-1] = fn;
73         signal(sig,signal_recorder);
74     }
75     caused &= ~(1<<(sig-1));
76     return Result;
77 }
78 
79 
80 /* Call the handlers for any pending signals */
81 
82 void handle_signals() {
83     int sig;
84 
85     if (caused)
86        for (sig=0; sig<__MAXSIG; sig++, caused>>=1)
87            if (caused&1)
88                (*handler[sig])(sig+1);
89 }
90