lib/libedit/sig.c

   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
  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
 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
 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
 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
 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 }