g10/signal.c

   1 /* signal.c - signal handling
   2  * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   3  *               2005 Free Software Foundation, Inc.
   4  *
   5  * This file is part of GnuPG.
   6  *
   7  * GnuPG is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * GnuPG is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <signal.h>
  25 #include <unistd.h>
  26 #include <string.h>
  27 #include <errno.h>
  28 #include <assert.h>
  29
  30 #include "gpg.h"
  31 #include "options.h"
  32 #include "status.h"
  33 #include "util.h"
  34 #include "main.h"
  35 #include "ttyio.h"
  36
  37 #ifdef HAVE_DOSISH_SYSTEM
  38 void init_signals(void) {}
  39 void pause_on_sigusr(int which) {}
  40 #else
  41 static volatile int caught_fatal_sig = 0;
  42 static volatile int caught_sigusr1 = 0;
  43
  44 static void
  45 init_one_signal (int sig, RETSIGTYPE (*handler)(int), int check_ign )
  46 {
  47 #if defined(HAVE_SIGACTION) && defined(HAVE_STRUCT_SIGACTION)
  48     struct sigaction oact, nact;
  49
  50     if (check_ign) {
  51         /* we don't want to change an IGN handler */
  52         sigaction (sig, NULL, &oact );
  53         if (oact.sa_handler == SIG_IGN )
  54             return;
  55     }
  56
  57     nact.sa_handler = handler;
  58     sigemptyset (&nact.sa_mask);
  59     nact.sa_flags = 0;
  60     sigaction ( sig, &nact, NULL);
  61 #else
  62     RETSIGTYPE (*ohandler)(int);
  63
  64     ohandler = signal (sig, handler);
  65     if (check_ign && ohandler == SIG_IGN) {
  66         /* Change it back if it was already set to IGN */
  67         signal (sig, SIG_IGN);
  68     }
  69 #endif
  70 }
  71
  72 static RETSIGTYPE
  73 got_fatal_signal( int sig )
  74 {
  75     const char *s;
  76
  77     if( caught_fatal_sig )
  78         raise( sig );
  79     caught_fatal_sig = 1;
  80
  81     gcry_control (GCRYCTL_TERM_SECMEM );
  82
  83     tty_cleanup_rl_after_signal ();
  84     tty_cleanup_after_signal ();
  85
  86     /* Better don't translate these messages. */
  87     write(2, "\n", 1 );
  88     s = log_get_name(); if( s ) write(2, s, strlen(s) );
  89     write(2, ": ", 2 );
  90
  91 #if HAVE_DECL_SYS_SIGLIST && defined(NSIG)
  92     s = (sig >= 0 && sig < NSIG) ? sys_siglist[sig] : "?";
  93     write (2, s, strlen(s) );
  94 #else
  95     write (2, "signal ", 7 );
  96     if (sig < 0 || sig >=100)
  97         write (2, "?", 1);
  98     else {
  99         if (sig >= 10)
 100             write (2, "0123456789"+(sig/10), 1 );
 101         write (2, "0123456789"+(sig%10), 1 );
 102     }
 103 #endif
 104     write(2, " caught ... exiting\n", 20 );
 105
 106     /* Reset action to default action and raise signal again. */
 107     init_one_signal (sig, SIG_DFL, 0);
 108     dotlock_remove_lockfiles ();
 109 #ifdef __riscos__
 110     riscos_close_fds ();
 111 #endif /* __riscos__ */
 112     raise( sig );
 113 }
 114
 115
 116 static RETSIGTYPE
 117 got_usr_signal( int sig )
 118 {
 119     caught_sigusr1 = 1;
 120 }
 121
 122
 123 void
 124 init_signals()
 125 {
 126     init_one_signal (SIGINT, got_fatal_signal, 1 );
 127     init_one_signal (SIGHUP, got_fatal_signal, 1 );
 128     init_one_signal (SIGTERM, got_fatal_signal, 1 );
 129     init_one_signal (SIGQUIT, got_fatal_signal, 1 );
 130     init_one_signal (SIGSEGV, got_fatal_signal, 1 );
 131     init_one_signal (SIGUSR1, got_usr_signal, 0 );
 132     init_one_signal (SIGPIPE, SIG_IGN, 0 );
 133 }
 134
 135
 136 void
 137 pause_on_sigusr( int which )
 138 {
 139 #if defined(HAVE_SIGPROCMASK) && defined(HAVE_SIGSET_T)
 140     sigset_t mask, oldmask;
 141
 142     assert( which == 1 );
 143     sigemptyset( &mask );
 144     sigaddset( &mask, SIGUSR1 );
 145
 146     sigprocmask( SIG_BLOCK, &mask, &oldmask );
 147     while( !caught_sigusr1 )
 148         sigsuspend( &oldmask );
 149     caught_sigusr1 = 0;
 150     sigprocmask( SIG_UNBLOCK, &mask, NULL );
 151 #else
 152      assert (which == 1);
 153      sighold (SIGUSR1);
 154      while (!caught_sigusr1)
 155          sigpause(SIGUSR1);
 156      caught_sigusr1 = 0;
 157      sigrelse(SIGUSR1);
 158 #endif /*! HAVE_SIGPROCMASK && HAVE_SIGSET_T */
 159 }
 160
 161 /* Disabled - see comment in tdbio.c:tdbio_begin_transaction() */
 162 #if 0
 163 static void
 164 do_block( int block )
 165 {
 166     static int is_blocked;
 167 #if defined(HAVE_SIGPROCMASK) && defined(HAVE_SIGSET_T)
 168     static sigset_t oldmask;
 169
 170     if( block ) {
 171         sigset_t newmask;
 172
 173         if( is_blocked )
 174             log_bug("signals are already blocked\n");
 175         sigfillset( &newmask );
 176         sigprocmask( SIG_BLOCK, &newmask, &oldmask );
 177         is_blocked = 1;
 178     }
 179     else {
 180         if( !is_blocked )
 181             log_bug("signals are not blocked\n");
 182         sigprocmask( SIG_SETMASK, &oldmask, NULL );
 183         is_blocked = 0;
 184     }
 185 #else /*! HAVE_SIGPROCMASK && HAVE_SIGSET_T */
 186
 187 #if defined(NSIG)
 188 #define SIGSMAX (NSIG)
 189 #elif defined(MAXSIG)
 190 #define SIGSMAX (MAXSIG+1)
 191 #else
 192 #error "define SIGSMAX to the number of signals on your platform plus one"
 193 #endif
 194
 195     static void (*disposition[SIGSMAX])(int);
 196     int sig;
 197
 198     if( block ) {
 199         if( is_blocked )
 200             log_bug("signals are already blocked\n");
 201         for (sig=1; sig < SIGSMAX; sig++) {
 202             disposition[sig] = sigset (sig, SIG_HOLD);
 203         }
 204         is_blocked = 1;
 205     }
 206     else {
 207         if( !is_blocked )
 208             log_bug("signals are not blocked\n");
 209         for (sig=1; sig < SIGSMAX; sig++) {
 210             sigset (sig, disposition[sig]);
 211         }
 212         is_blocked = 0;
 213     }
 214 #endif /*! HAVE_SIGPROCMASK && HAVE_SIGSET_T */
 215 }
 216
 217 void
 218 block_all_signals()
 219 {
 220     do_block(1);
 221 }
 222
 223 void
 224 unblock_all_signals()
 225 {
 226     do_block(0);
 227 }
 228 #endif
 229
 230 #endif /* !HAVE_DOSISH_SYSTEM */