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-rw-r--r--common/signal.c251
1 files changed, 251 insertions, 0 deletions
diff --git a/common/signal.c b/common/signal.c
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--- /dev/null
+++ b/common/signal.c
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+/* signal.c - signal handling
+ * Copyright (C) 1998, 1999, 2000, 2001, 2002,
+ * 2005 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either
+ *
+ * - the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * or
+ *
+ * - the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * or both in parallel, as here.
+ *
+ * This file is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_SIGNAL_H
+# include <signal.h>
+#endif
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "util.h"
+
+
+#ifndef HAVE_DOSISH_SYSTEM
+static volatile int caught_fatal_sig;
+static volatile int caught_sigusr1;
+#endif
+static void (*cleanup_fnc)(void);
+
+
+#ifndef HAVE_DOSISH_SYSTEM
+static void
+init_one_signal (int sig, RETSIGTYPE (*handler)(int), int check_ign )
+{
+# ifdef HAVE_SIGACTION
+ struct sigaction oact, nact;
+
+ if (check_ign)
+ {
+ /* we don't want to change an IGN handler */
+ sigaction (sig, NULL, &oact );
+ if (oact.sa_handler == SIG_IGN )
+ return;
+ }
+
+ nact.sa_handler = handler;
+ sigemptyset (&nact.sa_mask);
+ nact.sa_flags = 0;
+ sigaction ( sig, &nact, NULL);
+# else
+ RETSIGTYPE (*ohandler)(int);
+
+ ohandler = signal (sig, handler);
+ if (check_ign && ohandler == SIG_IGN)
+ {
+ /* Change it back if it was already set to IGN */
+ signal (sig, SIG_IGN);
+ }
+# endif
+}
+#endif /*!HAVE_DOSISH_SYSTEM*/
+
+#ifndef HAVE_DOSISH_SYSTEM
+static const char *
+get_signal_name( int signum )
+{
+ /* Note that we can't use strsignal(), because it is not
+ reentrant. */
+#if HAVE_SIGDESCR_NP
+ return sigdescr_np (signum);
+#elif HAVE_DECL_SYS_SIGLIST && defined(NSIG)
+ return (signum >= 0 && signum < NSIG) ? sys_siglist[signum] : "?";
+#else
+ return NULL;
+#endif
+}
+#endif /*!HAVE_DOSISH_SYSTEM*/
+
+#ifndef HAVE_DOSISH_SYSTEM
+static RETSIGTYPE
+got_fatal_signal (int sig)
+{
+ const char *s;
+
+ if (caught_fatal_sig)
+ raise (sig);
+ caught_fatal_sig = 1;
+
+ if (cleanup_fnc)
+ cleanup_fnc ();
+ /* Better don't translate these messages. */
+ (void)write (2, "\n", 1 );
+ s = log_get_prefix (NULL);
+ if (s)
+ (void)write(2, s, strlen (s));
+ (void)write (2, ": signal ", 9 );
+ s = get_signal_name(sig);
+ if (s)
+ (void) write (2, s, strlen(s) );
+ else
+ {
+ /* We are in a signal handler so we can't use any kind of printf
+ even not sprintf. So we use a straightforward algorithm. We
+ got a report that on one particular system, raising a signal
+ while in this handler, the parameter SIG get sclobbered and
+ things are messed up because we modify its value. Although
+ this is a bug in that system, we will protect against it. */
+ if (sig < 0 || sig >= 100000)
+ (void)write (2, "?", 1);
+ else
+ {
+ int i, value, any=0;
+
+ for (value=sig,i=10000; i; i /= 10)
+ {
+ if (value >= i || ((any || i==1) && !(value/i)))
+ {
+ (void)write (2, &"0123456789"[value/i], 1);
+ if ((value/i))
+ any = 1;
+ value %= i;
+ }
+ }
+ }
+ }
+ (void)write (2, " caught ... exiting\n", 20);
+
+ /* Reset action to default action and raise signal again */
+ init_one_signal (sig, SIG_DFL, 0);
+ /* Fixme: remove_lockfiles ();*/
+#ifdef __riscos__
+ close_fds ();
+#endif /* __riscos__ */
+ raise( sig );
+}
+#endif /*!HAVE_DOSISH_SYSTEM*/
+
+#ifndef HAVE_DOSISH_SYSTEM
+static RETSIGTYPE
+got_usr_signal (int sig)
+{
+ (void)sig;
+ caught_sigusr1 = 1;
+}
+#endif /*!HAVE_DOSISH_SYSTEM*/
+
+void
+gnupg_init_signals (int mode, void (*fast_cleanup)(void))
+{
+ assert (!mode);
+
+ cleanup_fnc = fast_cleanup;
+#ifndef HAVE_DOSISH_SYSTEM
+ init_one_signal (SIGINT, got_fatal_signal, 1 );
+ init_one_signal (SIGHUP, got_fatal_signal, 1 );
+ init_one_signal (SIGTERM, got_fatal_signal, 1 );
+ init_one_signal (SIGQUIT, got_fatal_signal, 1 );
+ init_one_signal (SIGSEGV, got_fatal_signal, 1 );
+ init_one_signal (SIGUSR1, got_usr_signal, 0 );
+ init_one_signal (SIGPIPE, SIG_IGN, 0 );
+#endif
+}
+
+
+static void
+do_block (int block)
+{
+#ifdef HAVE_DOSISH_SYSTEM
+ (void)block;
+#else /*!HAVE_DOSISH_SYSTEM*/
+ static int is_blocked;
+#ifdef HAVE_SIGPROCMASK
+ static sigset_t oldmask;
+
+ if (block)
+ {
+ sigset_t newmask;
+
+ if (is_blocked)
+ log_bug ("signals are already blocked\n");
+ sigfillset( &newmask );
+ sigprocmask( SIG_BLOCK, &newmask, &oldmask );
+ is_blocked = 1;
+ }
+ else
+ {
+ if (!is_blocked)
+ log_bug("signals are not blocked\n");
+ sigprocmask (SIG_SETMASK, &oldmask, NULL);
+ is_blocked = 0;
+ }
+#else /*!HAVE_SIGPROCMASK*/
+ static void (*disposition[MAXSIG])();
+ int sig;
+
+ if (block)
+ {
+ if (is_blocked)
+ log_bug("signals are already blocked\n");
+ for (sig=1; sig < MAXSIG; sig++)
+ {
+ disposition[sig] = sigset (sig, SIG_HOLD);
+ }
+ is_blocked = 1;
+ }
+ else
+ {
+ if (!is_blocked)
+ log_bug ("signals are not blocked\n");
+ for (sig=1; sig < MAXSIG; sig++) {
+ sigset (sig, disposition[sig]);
+ }
+ is_blocked = 0;
+ }
+#endif /*!HAVE_SIGPROCMASK*/
+#endif /*!HAVE_DOSISH_SYSTEM*/
+}
+
+
+void
+gnupg_block_all_signals ()
+{
+ do_block(1);
+}
+
+void
+gnupg_unblock_all_signals ()
+{
+ do_block(0);
+}