xref: /openbsd-src/lib/libedit/sig.c (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1 /*	$OpenBSD: sig.c,v 1.13 2011/06/03 23:34:56 deraadt Exp $	*/
2 /*	$NetBSD: sig.c,v 1.15 2009/02/19 15:20:22 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 "el.h"
44 #include <stdlib.h>
45 
46 private EditLine *sel = NULL;
47 
48 private const int sighdl[] = {
49 #define	_DO(a)	(a),
50 	ALLSIGS
51 #undef	_DO
52 	- 1
53 };
54 
55 private void sig_handler(int);
56 
57 /* sig_handler():
58  *	This is the handler called for all signals
59  *	XXX: we cannot pass any data so we just store the old editline
60  *	state in a private variable
61  */
62 private void
63 sig_handler(int signo)
64 {
65 	int i, save_errno = errno;
66 	sigset_t nset, oset;
67 
68 	(void) sigemptyset(&nset);
69 	(void) sigaddset(&nset, signo);
70 	(void) sigprocmask(SIG_BLOCK, &nset, &oset);
71 
72 	sel->el_signal->sig_no = signo;
73 
74 	switch (signo) {
75 	case SIGCONT:
76 		tty_rawmode(sel);
77 		if (ed_redisplay(sel, 0) == CC_REFRESH)
78 			re_refresh(sel);
79 		term__flush(sel);
80 		break;
81 
82 	case SIGWINCH:
83 		el_resize(sel);
84 		break;
85 
86 	default:
87 		tty_cookedmode(sel);
88 		break;
89 	}
90 
91 	for (i = 0; sighdl[i] != -1; i++)
92 		if (signo == sighdl[i])
93 			break;
94 
95 	(void) sigaction(signo, &sel->el_signal->sig_action[i], NULL);
96 	sel->el_signal->sig_action[i].sa_handler = SIG_ERR;
97 	sel->el_signal->sig_action[i].sa_flags = 0;
98 	sigemptyset(&sel->el_signal->sig_action[i].sa_mask);
99 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
100 	(void) kill(0, signo);
101 	errno = save_errno;
102 }
103 
104 
105 /* sig_init():
106  *	Initialize all signal stuff
107  */
108 protected int
109 sig_init(EditLine *el)
110 {
111 	size_t i;
112 	sigset_t *nset, oset;
113 
114 	el->el_signal = el_malloc(sizeof(*el->el_signal));
115 	if (el->el_signal == NULL)
116 		return -1;
117 
118 	nset = &el->el_signal->sig_set;
119 	(void) sigemptyset(nset);
120 #define	_DO(a) (void) sigaddset(nset, a);
121 	ALLSIGS
122 #undef	_DO
123 	(void) sigprocmask(SIG_BLOCK, nset, &oset);
124 
125 	for (i = 0; sighdl[i] != -1; i++) {
126 		el->el_signal->sig_action[i].sa_handler = SIG_ERR;
127 		el->el_signal->sig_action[i].sa_flags = 0;
128 		sigemptyset(&el->el_signal->sig_action[i].sa_mask);
129 	}
130 
131 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
132 
133 	return 0;
134 }
135 
136 
137 /* sig_end():
138  *	Clear all signal stuff
139  */
140 protected void
141 sig_end(EditLine *el)
142 {
143 
144 	el_free((ptr_t) el->el_signal);
145 	el->el_signal = NULL;
146 }
147 
148 
149 /* sig_set():
150  *	set all the signal handlers
151  */
152 protected void
153 sig_set(EditLine *el)
154 {
155 	size_t i;
156 	sigset_t oset;
157 	struct sigaction osa, nsa;
158 
159 	nsa.sa_handler = sig_handler;
160 	nsa.sa_flags = 0;
161 	sigemptyset(&nsa.sa_mask);
162 
163 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
164 
165 	for (i = 0; sighdl[i] != -1; i++) {
166 		/* This could happen if we get interrupted */
167 		if (sigaction(sighdl[i], &nsa, &osa) != -1 &&
168 		    osa.sa_handler != sig_handler)
169 			el->el_signal->sig_action[i] = osa;
170 	}
171 	sel = el;
172 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
173 }
174 
175 
176 /* sig_clr():
177  *	clear all the signal handlers
178  */
179 protected void
180 sig_clr(EditLine *el)
181 {
182 	size_t i;
183 	sigset_t oset;
184 
185 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
186 
187 	for (i = 0; sighdl[i] != -1; i++)
188 		if (el->el_signal->sig_action[i].sa_handler != SIG_ERR)
189 			(void)sigaction(sighdl[i],
190 			    &el->el_signal->sig_action[i], NULL);
191 
192 	sel = NULL;		/* we are going to die if the handler is
193 				 * called */
194 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
195 }
196