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      1 /*	$NetBSD: sig.c,v 1.17 2011/07/28 20:50:55 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Christos Zoulas of Cornell University.
      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. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #include "config.h"
     36 #if !defined(lint) && !defined(SCCSID)
     37 #if 0
     38 static char sccsid[] = "@(#)sig.c	8.1 (Berkeley) 6/4/93";
     39 #else
     40 __RCSID("$NetBSD: sig.c,v 1.17 2011/07/28 20:50:55 christos Exp $");
     41 #endif
     42 #endif /* not lint && not SCCSID */
     43 
     44 /*
     45  * sig.c: Signal handling stuff.
     46  *	  our policy is to trap all signals, set a good state
     47  *	  and pass the ball to our caller.
     48  */
     49 #include "el.h"
     50 #include <stdlib.h>
     51 
     52 private EditLine *sel = NULL;
     53 
     54 private const int sighdl[] = {
     55 #define	_DO(a)	(a),
     56 	ALLSIGS
     57 #undef	_DO
     58 	- 1
     59 };
     60 
     61 private void sig_handler(int);
     62 
     63 /* sig_handler():
     64  *	This is the handler called for all signals
     65  *	XXX: we cannot pass any data so we just store the old editline
     66  *	state in a private variable
     67  */
     68 private void
     69 sig_handler(int signo)
     70 {
     71 	int i;
     72 	sigset_t nset, oset;
     73 
     74 	(void) sigemptyset(&nset);
     75 	(void) sigaddset(&nset, signo);
     76 	(void) sigprocmask(SIG_BLOCK, &nset, &oset);
     77 
     78 	sel->el_signal->sig_no = signo;
     79 
     80 	switch (signo) {
     81 	case SIGCONT:
     82 		tty_rawmode(sel);
     83 		if (ed_redisplay(sel, 0) == CC_REFRESH)
     84 			re_refresh(sel);
     85 		terminal__flush(sel);
     86 		break;
     87 
     88 	case SIGWINCH:
     89 		el_resize(sel);
     90 		break;
     91 
     92 	default:
     93 		tty_cookedmode(sel);
     94 		break;
     95 	}
     96 
     97 	for (i = 0; sighdl[i] != -1; i++)
     98 		if (signo == sighdl[i])
     99 			break;
    100 
    101 	(void) sigaction(signo, &sel->el_signal->sig_action[i], NULL);
    102 	sel->el_signal->sig_action[i].sa_handler = SIG_ERR;
    103 	sel->el_signal->sig_action[i].sa_flags = 0;
    104 	sigemptyset(&sel->el_signal->sig_action[i].sa_mask);
    105 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
    106 	(void) kill(0, signo);
    107 }
    108 
    109 
    110 /* sig_init():
    111  *	Initialize all signal stuff
    112  */
    113 protected int
    114 sig_init(EditLine *el)
    115 {
    116 	size_t i;
    117 	sigset_t *nset, oset;
    118 
    119 	el->el_signal = el_malloc(sizeof(*el->el_signal));
    120 	if (el->el_signal == NULL)
    121 		return -1;
    122 
    123 	nset = &el->el_signal->sig_set;
    124 	(void) sigemptyset(nset);
    125 #define	_DO(a) (void) sigaddset(nset, a);
    126 	ALLSIGS
    127 #undef	_DO
    128 	(void) sigprocmask(SIG_BLOCK, nset, &oset);
    129 
    130 	for (i = 0; sighdl[i] != -1; i++) {
    131 		el->el_signal->sig_action[i].sa_handler = SIG_ERR;
    132 		el->el_signal->sig_action[i].sa_flags = 0;
    133 		sigemptyset(&el->el_signal->sig_action[i].sa_mask);
    134 	}
    135 
    136 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
    137 
    138 	return 0;
    139 }
    140 
    141 
    142 /* sig_end():
    143  *	Clear all signal stuff
    144  */
    145 protected void
    146 sig_end(EditLine *el)
    147 {
    148 
    149 	el_free(el->el_signal);
    150 	el->el_signal = NULL;
    151 }
    152 
    153 
    154 /* sig_set():
    155  *	set all the signal handlers
    156  */
    157 protected void
    158 sig_set(EditLine *el)
    159 {
    160 	size_t i;
    161 	sigset_t oset;
    162 	struct sigaction osa, nsa;
    163 
    164 	nsa.sa_handler = sig_handler;
    165 	nsa.sa_flags = 0;
    166 	sigemptyset(&nsa.sa_mask);
    167 
    168 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
    169 
    170 	for (i = 0; sighdl[i] != -1; i++) {
    171 		/* This could happen if we get interrupted */
    172 		if (sigaction(sighdl[i], &nsa, &osa) != -1 &&
    173 		    osa.sa_handler != sig_handler)
    174 			el->el_signal->sig_action[i] = osa;
    175 	}
    176 	sel = el;
    177 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
    178 }
    179 
    180 
    181 /* sig_clr():
    182  *	clear all the signal handlers
    183  */
    184 protected void
    185 sig_clr(EditLine *el)
    186 {
    187 	size_t i;
    188 	sigset_t oset;
    189 
    190 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
    191 
    192 	for (i = 0; sighdl[i] != -1; i++)
    193 		if (el->el_signal->sig_action[i].sa_handler != SIG_ERR)
    194 			(void)sigaction(sighdl[i],
    195 			    &el->el_signal->sig_action[i], NULL);
    196 
    197 	sel = NULL;		/* we are going to die if the handler is
    198 				 * called */
    199 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
    200 }
    201