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
  85     /* Better don't translate these messages. */
  86     write(2, "\n", 1 );
  87     s = log_get_name(); if( s ) write(2, s, strlen(s) );
  88     write(2, ": ", 2 );
  89
  90 #if HAVE_DECL_SYS_SIGLIST && defined(NSIG)
  91     s = (sig >= 0 && sig < NSIG) ? sys_siglist[sig] : "?";
  92     write (2, s, strlen(s) );
  93 #else
  94     write (2, "signal ", 7 );
  95     if (sig < 0 || sig >=100)
  96         write (2, "?", 1);
  97     else {
  98         if (sig >= 10)
  99             write (2, "0123456789"+(sig/10), 1 );
 100         write (2, "0123456789"+(sig%10), 1 );
 101     }
 102 #endif
 103     write(2, " caught ... exiting\n", 20 );
 104
 105     /* Reset action to default action and raise signal again. */
 106     init_one_signal (sig, SIG_DFL, 0);
 107     dotlock_remove_lockfiles ();
 108 #ifdef __riscos__
 109     riscos_close_fds ();
 110 #endif /* __riscos__ */
 111     raise( sig );
 112 }
 113
 114
 115 static RETSIGTYPE
 116 got_usr_signal( int sig )
 117 {
 118     caught_sigusr1 = 1;
 119 }
 120
 121
 122 void
 123 init_signals()
 124 {
 125     init_one_signal (SIGINT, got_fatal_signal, 1 );
 126     init_one_signal (SIGHUP, got_fatal_signal, 1 );
 127     init_one_signal (SIGTERM, got_fatal_signal, 1 );
 128     init_one_signal (SIGQUIT, got_fatal_signal, 1 );
 129     init_one_signal (SIGSEGV, got_fatal_signal, 1 );
 130     init_one_signal (SIGUSR1, got_usr_signal, 0 );
 131     init_one_signal (SIGPIPE, SIG_IGN, 0 );
 132 }
 133
 134
 135 void
 136 pause_on_sigusr( int which )
 137 {
 138 #if defined(HAVE_SIGPROCMASK) && defined(HAVE_SIGSET_T)
 139     sigset_t mask, oldmask;
 140
 141     assert( which == 1 );
 142     sigemptyset( &mask );
 143     sigaddset( &mask, SIGUSR1 );
 144
 145     sigprocmask( SIG_BLOCK, &mask, &oldmask );
 146     while( !caught_sigusr1 )
 147         sigsuspend( &oldmask );
 148     caught_sigusr1 = 0;
 149     sigprocmask( SIG_UNBLOCK, &mask, NULL );
 150 #else
 151      assert (which == 1);
 152      sighold (SIGUSR1);
 153      while (!caught_sigusr1)
 154          sigpause(SIGUSR1);
 155      caught_sigusr1 = 0;
 156      sigrelse(SIGUSR1);
 157 #endif /*! HAVE_SIGPROCMASK && HAVE_SIGSET_T */
 158 }
 159
 160 /* Disabled - see comment in tdbio.c:tdbio_begin_transaction() */
 161 #if 0
 162 static void
 163 do_block( int block )
 164 {
 165     static int is_blocked;
 166 #if defined(HAVE_SIGPROCMASK) && defined(HAVE_SIGSET_T)
 167     static sigset_t oldmask;
 168
 169     if( block ) {
 170         sigset_t newmask;
 171
 172         if( is_blocked )
 173             log_bug("signals are already blocked\n");
 174         sigfillset( &newmask );
 175         sigprocmask( SIG_BLOCK, &newmask, &oldmask );
 176         is_blocked = 1;
 177     }
 178     else {
 179         if( !is_blocked )
 180             log_bug("signals are not blocked\n");
 181         sigprocmask( SIG_SETMASK, &oldmask, NULL );
 182         is_blocked = 0;
 183     }
 184 #else /*! HAVE_SIGPROCMASK && HAVE_SIGSET_T */
 185
 186 #if defined(NSIG)
 187 #define SIGSMAX (NSIG)
 188 #elif defined(MAXSIG)
 189 #define SIGSMAX (MAXSIG+1)
 190 #else
 191 #error "define SIGSMAX to the number of signals on your platform plus one"
 192 #endif
 193
 194     static void (*disposition[SIGSMAX])(int);
 195     int sig;
 196
 197     if( block ) {
 198         if( is_blocked )
 199             log_bug("signals are already blocked\n");
 200         for (sig=1; sig < SIGSMAX; sig++) {
 201             disposition[sig] = sigset (sig, SIG_HOLD);
 202         }
 203         is_blocked = 1;
 204     }
 205     else {
 206         if( !is_blocked )
 207             log_bug("signals are not blocked\n");
 208         for (sig=1; sig < SIGSMAX; sig++) {
 209             sigset (sig, disposition[sig]);
 210         }
 211         is_blocked = 0;
 212     }
 213 #endif /*! HAVE_SIGPROCMASK && HAVE_SIGSET_T */
 214 }
 215
 216 void
 217 block_all_signals()
 218 {
 219     do_block(1);
 220 }
 221
 222 void
 223 unblock_all_signals()
 224 {
 225     do_block(0);
 226 }
 227 #endif
 228
 229 #endif /* !HAVE_DOSISH_SYSTEM */