1 /* $NetBSD: sigset.c,v 1.1 2003/01/15 23:55:43 kleink Exp $ */ 2 3 /*- 4 * Copyright (c) 2003 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Klaus Klein. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 __RCSID("$NetBSD: sigset.c,v 1.1 2003/01/15 23:55:43 kleink Exp $"); 42 #endif 43 44 #include "namespace.h" 45 #include <errno.h> 46 #include <signal.h> 47 #include <stddef.h> 48 49 sig_t 50 sigset(int sig, void (*disp)(int)) 51 { 52 sigset_t set, oset; 53 struct sigaction sa, osa; 54 55 osa.sa_handler = SIG_ERR; 56 57 if (disp == SIG_HOLD) { 58 /* Add sig to current signal mask. */ 59 if (sigemptyset(&set) != 0) 60 goto out; 61 if (sigaddset(&set, sig) != 0) 62 goto out; 63 if (sigprocmask(SIG_BLOCK, &set, &oset) != 0) 64 goto out; 65 66 if (sigismember(&oset, sig)) { 67 /* Had been masked before, return SIG_HOLD. */ 68 osa.sa_handler = SIG_HOLD; 69 } else { 70 /* Return previous disposition. */ 71 (void)sigaction(sig, NULL, &osa); 72 } 73 } else if (disp == SIG_ERR) { 74 errno = EINVAL; 75 } else { 76 /* Set up and install new disposition. */ 77 sa.sa_handler = disp; 78 if (sigemptyset(&sa.sa_mask) != 0) 79 goto out; 80 sa.sa_flags = 0; 81 82 if (sigaction(sig, &sa, &osa) != 0) { 83 osa.sa_handler = SIG_ERR; 84 goto out; 85 } 86 87 /* Delete sig from current signal mask. */ 88 if (sigemptyset(&set) != 0) 89 return (SIG_ERR); 90 if (sigaddset(&set, sig) != 0) 91 return (SIG_ERR); 92 if (sigprocmask(SIG_UNBLOCK, &set, &oset) != 0) 93 return (SIG_ERR); 94 95 /* If had been masked before, return SIG_HOLD. */ 96 if (sigismember(&oset, sig)) 97 osa.sa_handler = SIG_HOLD; 98 } 99 100 out: 101 return (osa.sa_handler); 102 } 103