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sig.c revision 1.22
      1 /*	$NetBSD: sig.c,v 1.22 2016/02/16 15:53:48 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 1.22 2016/02/16 15:53:48 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, save_errno;
     72 	sigset_t nset, oset;
     73 
     74 	save_errno = errno;
     75 	(void) sigemptyset(&nset);
     76 	(void) sigaddset(&nset, signo);
     77 	(void) sigprocmask(SIG_BLOCK, &nset, &oset);
     78 
     79 	sel->el_signal->sig_no = signo;
     80 
     81 	switch (signo) {
     82 	case SIGCONT:
     83 		tty_rawmode(sel);
     84 		if (ed_redisplay(sel, 0) == CC_REFRESH)
     85 			re_refresh(sel);
     86 		terminal__flush(sel);
     87 		break;
     88 
     89 	case SIGWINCH:
     90 		el_resize(sel);
     91 		break;
     92 
     93 	default:
     94 		tty_cookedmode(sel);
     95 		break;
     96 	}
     97 
     98 	for (i = 0; sighdl[i] != -1; i++)
     99 		if (signo == sighdl[i])
    100 			break;
    101 
    102 	(void) sigaction(signo, &sel->el_signal->sig_action[i], NULL);
    103 	sel->el_signal->sig_action[i].sa_handler = SIG_ERR;
    104 	sel->el_signal->sig_action[i].sa_flags = 0;
    105 	sigemptyset(&sel->el_signal->sig_action[i].sa_mask);
    106 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
    107 	(void) kill(0, signo);
    108 	errno = save_errno;
    109 }
    110 
    111 
    112 /* sig_init():
    113  *	Initialize all signal stuff
    114  */
    115 protected int
    116 sig_init(EditLine *el)
    117 {
    118 	size_t i;
    119 	sigset_t *nset, oset;
    120 
    121 	el->el_signal = el_malloc(sizeof(*el->el_signal));
    122 	if (el->el_signal == NULL)
    123 		return -1;
    124 
    125 	nset = &el->el_signal->sig_set;
    126 	(void) sigemptyset(nset);
    127 #define	_DO(a) (void) sigaddset(nset, a);
    128 	ALLSIGS
    129 #undef	_DO
    130 	(void) sigprocmask(SIG_BLOCK, nset, &oset);
    131 
    132 	for (i = 0; sighdl[i] != -1; i++) {
    133 		el->el_signal->sig_action[i].sa_handler = SIG_ERR;
    134 		el->el_signal->sig_action[i].sa_flags = 0;
    135 		sigemptyset(&el->el_signal->sig_action[i].sa_mask);
    136 	}
    137 
    138 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
    139 
    140 	return 0;
    141 }
    142 
    143 
    144 /* sig_end():
    145  *	Clear all signal stuff
    146  */
    147 protected void
    148 sig_end(EditLine *el)
    149 {
    150 
    151 	el_free(el->el_signal);
    152 	el->el_signal = NULL;
    153 }
    154 
    155 
    156 /* sig_set():
    157  *	set all the signal handlers
    158  */
    159 protected void
    160 sig_set(EditLine *el)
    161 {
    162 	size_t i;
    163 	sigset_t oset;
    164 	struct sigaction osa, nsa;
    165 
    166 	nsa.sa_handler = sig_handler;
    167 	nsa.sa_flags = 0;
    168 	sigemptyset(&nsa.sa_mask);
    169 
    170 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
    171 
    172 	for (i = 0; sighdl[i] != -1; i++) {
    173 		/* This could happen if we get interrupted */
    174 		if (sigaction(sighdl[i], &nsa, &osa) != -1 &&
    175 		    osa.sa_handler != sig_handler)
    176 			el->el_signal->sig_action[i] = osa;
    177 	}
    178 	sel = el;
    179 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
    180 }
    181 
    182 
    183 /* sig_clr():
    184  *	clear all the signal handlers
    185  */
    186 protected void
    187 sig_clr(EditLine *el)
    188 {
    189 	size_t i;
    190 	sigset_t oset;
    191 
    192 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
    193 
    194 	for (i = 0; sighdl[i] != -1; i++)
    195 		if (el->el_signal->sig_action[i].sa_handler != SIG_ERR)
    196 			(void)sigaction(sighdl[i],
    197 			    &el->el_signal->sig_action[i], NULL);
    198 
    199 	sel = NULL;		/* we are going to die if the handler is
    200 				 * called */
    201 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
    202 }
    203