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 1.2 2003/06/17 04:30:01 dillon 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 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 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 96 sig_Handle() 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