FreeRDP/libfreerdp/utils/signal.c
2023-05-04 12:56:16 +02:00

257 lines
5.8 KiB
C

/**
* FreeRDP: A Remote Desktop Protocol Implementation
* Signal handling
*
* Copyright 2011 Shea Levy <shea@shealevy.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <freerdp/config.h>
#include <stddef.h>
#include <errno.h>
#include <string.h>
#include <winpr/crt.h>
#include <freerdp/utils/signal.h>
#include <freerdp/log.h>
#ifndef _WIN32
#include <signal.h>
#include <termios.h>
#endif
#define TAG FREERDP_TAG("utils.signal")
#ifdef _WIN32
int freerdp_handle_signals(void)
{
errno = ENOSYS;
return -1;
}
BOOL freerdp_add_signal_cleanup_handler(void* context, freerdp_signal_handler_t fkt)
{
return FALSE;
}
BOOL freerdp_del_signal_cleanup_handler(void* context, freerdp_signal_handler_t fkt)
{
return FALSE;
}
#else
#include <pthread.h>
#include <winpr/debug.h>
static BOOL handlers_registered = FALSE;
static pthread_mutex_t signal_handler_lock = PTHREAD_MUTEX_INITIALIZER;
typedef struct
{
void* context;
freerdp_signal_handler_t handler;
} cleanup_handler_t;
static size_t cleanup_handler_count = 0;
static cleanup_handler_t cleanup_handlers[20] = { 0 };
static void lock(void)
{
const int rc = pthread_mutex_lock(&signal_handler_lock);
if (rc != 0)
WLog_ERR(TAG, "[pthread_mutex_lock] failed with %s [%d]", strerror(rc), rc);
}
static void unlock(void)
{
const int rc = pthread_mutex_unlock(&signal_handler_lock);
if (rc != 0)
WLog_ERR(TAG, "[pthread_mutex_lock] failed with %s [%d]", strerror(rc), rc);
}
static void term_handler(int signum)
{
static BOOL recursive = FALSE;
if (!recursive)
{
recursive = TRUE;
WLog_ERR(TAG, "Caught signal '%s' [%d]", strsignal(signum), signum);
}
lock();
for (size_t x = 0; x < cleanup_handler_count; x++)
{
const cleanup_handler_t empty = { 0 };
cleanup_handler_t* cur = &cleanup_handlers[x];
if (cur->handler)
cur->handler(signum, strsignal(signum), cur->context);
*cur = empty;
}
cleanup_handler_count = 0;
unlock();
}
static void fatal_handler(int signum)
{
struct sigaction default_sigaction;
sigset_t this_mask;
static BOOL recursive = FALSE;
if (!recursive)
{
recursive = TRUE;
WLog_ERR(TAG, "Caught signal '%s' [%d]", strsignal(signum), signum);
winpr_log_backtrace(TAG, WLOG_ERROR, 20);
}
default_sigaction.sa_handler = SIG_DFL;
sigfillset(&(default_sigaction.sa_mask));
default_sigaction.sa_flags = 0;
sigaction(signum, &default_sigaction, NULL);
sigemptyset(&this_mask);
sigaddset(&this_mask, signum);
pthread_sigmask(SIG_UNBLOCK, &this_mask, NULL);
raise(signum);
}
static const int term_signals[] = { SIGINT, SIGKILL, SIGQUIT, SIGSTOP, SIGTERM };
static const int fatal_signals[] = { SIGABRT, SIGALRM, SIGBUS, SIGFPE, SIGHUP, SIGILL,
SIGSEGV, SIGTSTP, SIGTTIN, SIGTTOU, SIGUSR1, SIGUSR2,
#ifdef SIGPOLL
SIGPOLL,
#endif
#ifdef SIGPROF
SIGPROF,
#endif
#ifdef SIGSYS
SIGSYS,
#endif
SIGTRAP,
#ifdef SIGVTALRM
SIGVTALRM,
#endif
SIGXCPU, SIGXFSZ };
static BOOL register_handlers(const int* signals, size_t count, void (*handler)(int))
{
WINPR_ASSERT(signals || (count == 0));
WINPR_ASSERT(handler);
sigset_t orig_set = { 0 };
struct sigaction saction = { 0 };
pthread_sigmask(SIG_BLOCK, &(saction.sa_mask), &orig_set);
sigfillset(&(saction.sa_mask));
sigdelset(&(saction.sa_mask), SIGCONT);
saction.sa_handler = handler;
saction.sa_flags = 0;
for (size_t x = 0; x < count; x++)
{
struct sigaction orig_sigaction = { 0 };
if (sigaction(signals[x], NULL, &orig_sigaction) == 0)
{
if (orig_sigaction.sa_handler != SIG_IGN)
{
sigaction(signals[x], &saction, NULL);
}
}
}
pthread_sigmask(SIG_SETMASK, &orig_set, NULL);
return TRUE;
}
int freerdp_handle_signals(void)
{
int rc = -1;
lock();
WLog_DBG(TAG, "Registering signal hook...");
if (!register_handlers(fatal_signals, ARRAYSIZE(fatal_signals), fatal_handler))
goto fail;
if (!register_handlers(term_signals, ARRAYSIZE(term_signals), term_handler))
goto fail;
/* Ignore SIGPIPE signal. */
signal(SIGPIPE, SIG_IGN);
handlers_registered = TRUE;
rc = 0;
fail:
unlock();
return rc;
}
BOOL freerdp_add_signal_cleanup_handler(void* context, freerdp_signal_handler_t handler)
{
BOOL rc = FALSE;
lock();
if (handlers_registered)
{
if (cleanup_handler_count < ARRAYSIZE(cleanup_handlers))
{
cleanup_handler_t* cur = &cleanup_handlers[cleanup_handler_count++];
cur->context = context;
cur->handler = handler;
}
else
WLog_WARN(TAG, "Failed to register cleanup handler, only %" PRIuz " handlers supported",
ARRAYSIZE(cleanup_handlers));
}
rc = TRUE;
unlock();
return rc;
}
BOOL freerdp_del_signal_cleanup_handler(void* context, freerdp_signal_handler_t handler)
{
BOOL rc = FALSE;
lock();
if (handlers_registered)
{
for (size_t x = 0; x < cleanup_handler_count; x++)
{
cleanup_handler_t* cur = &cleanup_handlers[x];
if ((cur->context == context) && (cur->handler == handler))
{
const cleanup_handler_t empty = { 0 };
for (size_t y = x + 1; y < cleanup_handler_count - 1; y++)
{
*cur++ = cleanup_handlers[y];
}
*cur = empty;
cleanup_handler_count--;
break;
}
}
}
rc = TRUE;
unlock();
return rc;
}
#endif