diff options
Diffstat (limited to 'common/signal.c')
| -rw-r--r-- | common/signal.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/common/signal.c b/common/signal.c new file mode 100644 index 0000000..92925fd --- /dev/null +++ b/common/signal.c @@ -0,0 +1,251 @@ +/* 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); +} |