badvpn/system/BUnixSignal.h
2016-08-17 21:34:21 +02:00

133 lines
4.2 KiB
C

/**
* @file BUnixSignal.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
* Object for catching unix signals.
*/
#ifndef BADVPN_SYSTEM_BUNIXSIGNAL_H
#define BADVPN_SYSTEM_BUNIXSIGNAL_H
#if (defined(BADVPN_USE_SIGNALFD) + defined(BADVPN_USE_KEVENT) + defined(BADVPN_USE_SELFPIPE)) != 1
#error Unknown signal backend or too many signal backends
#endif
#include <unistd.h>
#include <signal.h>
#include <misc/debug.h>
#include <system/BReactor.h>
#include <base/DebugObject.h>
struct BUnixSignal_s;
/**
* Handler function called when a signal is received.
*
* @param user as in {@link BUnixSignal_Init}
* @param signo signal number. Will be one of the signals provided to {@link signals}.
*/
typedef void (*BUnixSignal_handler) (void *user, int signo);
#ifdef BADVPN_USE_KEVENT
struct BUnixSignal_kevent_entry {
struct BUnixSignal_s *parent;
int signo;
BReactorKEvent kevent;
};
#endif
#ifdef BADVPN_USE_SELFPIPE
struct BUnixSignal_selfpipe_entry {
struct BUnixSignal_s *parent;
int signo;
int pipefds[2];
BFileDescriptor pipe_read_bfd;
};
#endif
/**
* Object for catching unix signals.
*/
typedef struct BUnixSignal_s {
BReactor *reactor;
sigset_t signals;
BUnixSignal_handler handler;
void *user;
#ifdef BADVPN_USE_SIGNALFD
int signalfd_fd;
BFileDescriptor signalfd_bfd;
#endif
#ifdef BADVPN_USE_KEVENT
struct BUnixSignal_kevent_entry *entries;
int num_entries;
#endif
#ifdef BADVPN_USE_SELFPIPE
struct BUnixSignal_selfpipe_entry *entries;
int num_entries;
#endif
DebugObject d_obj;
} BUnixSignal;
/**
* Initializes the object.
* {@link BLog_Init} must have been done.
*
* WARNING: for every signal number there should be at most one {@link BUnixSignal}
* object handling it (or anything else that could interfere).
*
* This blocks the signal using pthread_sigmask() and sets up signalfd() for receiving
* signals.
*
* @param o the object
* @param reactor reactor we live in
* @param signals signals to handle. See man 3 sigsetops.
* @param handler handler function to call when a signal is received
* @param user value passed to callback function
* @return 1 on success, 0 on failure
*/
int BUnixSignal_Init (BUnixSignal *o, BReactor *reactor, sigset_t signals, BUnixSignal_handler handler, void *user) WARN_UNUSED;
/**
* Frees the object.
*
* @param o the object
* @param unblock whether to unblock the signals using pthread_sigmask(). Not unblocking it
* can be used while the program is exiting gracefully to prevent the
* signals from being handled handled according to its default disposition
* after this function is called. Must be 0 or 1.
*/
void BUnixSignal_Free (BUnixSignal *o, int unblock);
#endif