xref: /freebsd/contrib/libedit/sig.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*	$NetBSD: sig.c,v 1.26 2016/05/09 21:46:56 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 1.26 2016/05/09 21:46:56 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 <errno.h>
50 #include <stdlib.h>
51 
52 #include "el.h"
53 #include "common.h"
54 
55 static EditLine *sel = NULL;
56 
57 static const int sighdl[] = {
58 #define	_DO(a)	(a),
59 	ALLSIGS
60 #undef	_DO
61 	- 1
62 };
63 
64 static void sig_handler(int);
65 
66 /* sig_handler():
67  *	This is the handler called for all signals
68  *	XXX: we cannot pass any data so we just store the old editline
69  *	state in a private variable
70  */
71 static void
72 sig_handler(int signo)
73 {
74 	int i, save_errno;
75 	sigset_t nset, oset;
76 
77 	save_errno = errno;
78 	(void) sigemptyset(&nset);
79 	(void) sigaddset(&nset, signo);
80 	(void) sigprocmask(SIG_BLOCK, &nset, &oset);
81 
82 	sel->el_signal->sig_no = signo;
83 
84 	switch (signo) {
85 	case SIGCONT:
86 		tty_rawmode(sel);
87 		if (ed_redisplay(sel, 0) == CC_REFRESH)
88 			re_refresh(sel);
89 		terminal__flush(sel);
90 		break;
91 
92 	case SIGWINCH:
93 		el_resize(sel);
94 		break;
95 
96 	default:
97 		tty_cookedmode(sel);
98 		break;
99 	}
100 
101 	for (i = 0; sighdl[i] != -1; i++)
102 		if (signo == sighdl[i])
103 			break;
104 
105 	(void) sigaction(signo, &sel->el_signal->sig_action[i], NULL);
106 	sel->el_signal->sig_action[i].sa_handler = SIG_ERR;
107 	sel->el_signal->sig_action[i].sa_flags = 0;
108 	sigemptyset(&sel->el_signal->sig_action[i].sa_mask);
109 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
110 	(void) kill(0, signo);
111 	errno = save_errno;
112 }
113 
114 
115 /* sig_init():
116  *	Initialize all signal stuff
117  */
118 libedit_private int
119 sig_init(EditLine *el)
120 {
121 	size_t i;
122 	sigset_t *nset, oset;
123 
124 	el->el_signal = el_malloc(sizeof(*el->el_signal));
125 	if (el->el_signal == NULL)
126 		return -1;
127 
128 	nset = &el->el_signal->sig_set;
129 	(void) sigemptyset(nset);
130 #define	_DO(a) (void) sigaddset(nset, a);
131 	ALLSIGS
132 #undef	_DO
133 	(void) sigprocmask(SIG_BLOCK, nset, &oset);
134 
135 	for (i = 0; sighdl[i] != -1; i++) {
136 		el->el_signal->sig_action[i].sa_handler = SIG_ERR;
137 		el->el_signal->sig_action[i].sa_flags = 0;
138 		sigemptyset(&el->el_signal->sig_action[i].sa_mask);
139 	}
140 
141 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
142 
143 	return 0;
144 }
145 
146 
147 /* sig_end():
148  *	Clear all signal stuff
149  */
150 libedit_private void
151 sig_end(EditLine *el)
152 {
153 
154 	el_free(el->el_signal);
155 	el->el_signal = NULL;
156 }
157 
158 
159 /* sig_set():
160  *	set all the signal handlers
161  */
162 libedit_private void
163 sig_set(EditLine *el)
164 {
165 	size_t i;
166 	sigset_t oset;
167 	struct sigaction osa, nsa;
168 
169 	nsa.sa_handler = sig_handler;
170 	nsa.sa_flags = 0;
171 	sigemptyset(&nsa.sa_mask);
172 
173 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
174 
175 	for (i = 0; sighdl[i] != -1; i++) {
176 		/* This could happen if we get interrupted */
177 		if (sigaction(sighdl[i], &nsa, &osa) != -1 &&
178 		    osa.sa_handler != sig_handler)
179 			el->el_signal->sig_action[i] = osa;
180 	}
181 	sel = el;
182 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
183 }
184 
185 
186 /* sig_clr():
187  *	clear all the signal handlers
188  */
189 libedit_private void
190 sig_clr(EditLine *el)
191 {
192 	size_t i;
193 	sigset_t oset;
194 
195 	(void) sigprocmask(SIG_BLOCK, &el->el_signal->sig_set, &oset);
196 
197 	for (i = 0; sighdl[i] != -1; i++)
198 		if (el->el_signal->sig_action[i].sa_handler != SIG_ERR)
199 			(void)sigaction(sighdl[i],
200 			    &el->el_signal->sig_action[i], NULL);
201 
202 	sel = NULL;		/* we are going to die if the handler is
203 				 * called */
204 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
205 }
206