xref: /openbsd/lib/libedit/sig.c (revision ddc81437)
1 /*	$OpenBSD: sig.c,v 1.19 2016/04/11 21:17:29 schwarze Exp $	*/
2 /*	$NetBSD: sig.c,v 1.25 2016/04/11 18:56:31 christos Exp $	*/
3 
4 /*-
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Christos Zoulas of Cornell University.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "config.h"
37 
38 /*
39  * sig.c: Signal handling stuff.
40  *	  our policy is to trap all signals, set a good state
41  *	  and pass the ball to our caller.
42  */
43 #include <errno.h>
44 #include <stdlib.h>
45 
46 #include "el.h"
47 #include "common.h"
48 
49 static EditLine *sel = NULL;
50 
51 static const int sighdl[] = {
52 #define	_DO(a)	(a),
53 	ALLSIGS
54 #undef	_DO
55 	- 1
56 };
57 
58 static void sig_handler(int);
59 
60 /* sig_handler():
61  *	This is the handler called for all signals
62  *	XXX: we cannot pass any data so we just store the old editline
63  *	state in a private variable
64  */
65 static void
sig_handler(int signo)66 sig_handler(int signo)
67 {
68 	int i, save_errno;
69 	sigset_t nset, oset;
70 
71 	save_errno = errno;
72 	(void) sigemptyset(&nset);
73 	(void) sigaddset(&nset, signo);
74 	(void) sigprocmask(SIG_BLOCK, &nset, &oset);
75 
76 	sel->el_signal->sig_no = signo;
77 
78 	switch (signo) {
79 	case SIGCONT:
80 		tty_rawmode(sel);
81 		if (ed_redisplay(sel, 0) == CC_REFRESH)
82 			re_refresh(sel);
83 		terminal__flush(sel);
84 		break;
85 
86 	case SIGWINCH:
87 		el_resize(sel);
88 		break;
89 
90 	default:
91 		tty_cookedmode(sel);
92 		break;
93 	}
94 
95 	for (i = 0; sighdl[i] != -1; i++)
96 		if (signo == sighdl[i])
97 			break;
98 
99 	(void) sigaction(signo, &sel->el_signal->sig_action[i], NULL);
100 	sel->el_signal->sig_action[i].sa_handler = SIG_ERR;
101 	sel->el_signal->sig_action[i].sa_flags = 0;
102 	sigemptyset(&sel->el_signal->sig_action[i].sa_mask);
103 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
104 	(void) kill(0, signo);
105 	errno = save_errno;
106 }
107 
108 
109 /* sig_init():
110  *	Initialize all signal stuff
111  */
112 protected int
sig_init(EditLine * el)113 sig_init(EditLine *el)
114 {
115 	size_t i;
116 	sigset_t *nset, oset;
117 
118 	el->el_signal = malloc(sizeof(*el->el_signal));
119 	if (el->el_signal == NULL)
120 		return -1;
121 
122 	nset = &el->el_signal->sig_set;
123 	(void) sigemptyset(nset);
124 #define	_DO(a) (void) sigaddset(nset, a);
125 	ALLSIGS
126 #undef	_DO
127 	(void) sigprocmask(SIG_BLOCK, nset, &oset);
128 
129 	for (i = 0; sighdl[i] != -1; i++) {
130 		el->el_signal->sig_action[i].sa_handler = SIG_ERR;
131 		el->el_signal->sig_action[i].sa_flags = 0;
132 		sigemptyset(&el->el_signal->sig_action[i].sa_mask);
133 	}
134 
135 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
136 
137 	return 0;
138 }
139 
140 
141 /* sig_end():
142  *	Clear all signal stuff
143  */
144 protected void
sig_end(EditLine * el)145 sig_end(EditLine *el)
146 {
147 
148 	free(el->el_signal);
149 	el->el_signal = NULL;
150 }
151 
152 
153 /* sig_set():
154  *	set all the signal handlers
155  */
156 protected void
sig_set(EditLine * el)157 sig_set(EditLine *el)
158 {
159 	size_t i;
160 	sigset_t oset;
161 	struct sigaction osa, nsa;
162 
163 	nsa.sa_handler = sig_handler;
164 	nsa.sa_flags = 0;
165 	sigemptyset(&nsa.sa_mask);
166 
167 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
168 
169 	for (i = 0; sighdl[i] != -1; i++) {
170 		/* This could happen if we get interrupted */
171 		if (sigaction(sighdl[i], &nsa, &osa) != -1 &&
172 		    osa.sa_handler != sig_handler)
173 			el->el_signal->sig_action[i] = osa;
174 	}
175 	sel = el;
176 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
177 }
178 
179 
180 /* sig_clr():
181  *	clear all the signal handlers
182  */
183 protected void
sig_clr(EditLine * el)184 sig_clr(EditLine *el)
185 {
186 	size_t i;
187 	sigset_t oset;
188 
189 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
190 
191 	for (i = 0; sighdl[i] != -1; i++)
192 		if (el->el_signal->sig_action[i].sa_handler != SIG_ERR)
193 			(void)sigaction(sighdl[i],
194 			    &el->el_signal->sig_action[i], NULL);
195 
196 	sel = NULL;		/* we are going to die if the handler is
197 				 * called */
198 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
199 }
200