/* NetHalt - NT service library
 * Copyright (C) 2008 Daniel Collins <solemnwarning@solemnwarning.net>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *	* Redistributions of source code must retain the above copyright
 *	  notice, this list of conditions and the following disclaimer.
 *
 *	* 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.
 *
 *	* 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 AUTHOR ``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.
*/

#include <windows.h>
#include <stdio.h>
#include <setjmp.h>

#include "ntservice.h"
#include "lib.h"

SERVICE_STATUS svc_status;
static SERVICE_STATUS_HANDLE svc_handle;
static jmp_buf exit_jmp;

static void WINAPI ServiceMain(DWORD argc, char **argv);
static void ServiceState(DWORD state);
static void WINAPI ServiceCallback(DWORD signal);

int main(int argc, char **argv) {
	SERVICE_TABLE_ENTRY serviceTable[] = {
		{(char*)svc_name, &ServiceMain},
		{NULL, NULL}
	};
	
	if(!(StartServiceCtrlDispatcher(serviceTable))) {
		LogError("StartServiceCtrlDispatcher() failed: %s", w32_error(GetLastError()));
		return 1;
	}
	
	return 0;
}

/* Start the service */
static void WINAPI ServiceMain(DWORD argc, char **argv) {
	svc_status.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
	svc_status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
	svc_status.dwWin32ExitCode = NO_ERROR;
	svc_status.dwCheckPoint = 0;
	svc_status.dwWaitHint = 30000;
	
	svc_handle = RegisterServiceCtrlHandler(svc_name, (LPHANDLER_FUNCTION)&ServiceCallback);
	if(!svc_handle) {
		LogError("RegisterServiceCtrlHandler() failed: %s", w32_error(GetLastError()));
		return;
	}
	
	ServiceState(SERVICE_START_PENDING);
	
	if(setjmp(exit_jmp) == 0) {
		svc_init();
		ServiceState(SERVICE_RUNNING);
		svc_main();
	}
	
	svc_cleanup();
	
	ServiceState(SERVICE_STOPPED);
}

/* Update the service status and notify the SCM */
static void ServiceState(DWORD state) {
	svc_status.dwCurrentState = state;
	svc_status.dwCheckPoint++;
	
	SetServiceStatus(svc_handle, &svc_status);
}

/* Handle service control signals */
static void WINAPI ServiceCallback(DWORD signal) {
	if(signal == SERVICE_CONTROL_SHUTDOWN || signal == SERVICE_CONTROL_STOP) {
		ServiceState(SERVICE_STOP_PENDING);
		return;
	}
	
	ServiceState(svc_status.dwCurrentState);
}

/* Write an event to the event log */
void LogEvent(int type, int id, char const *fmt, ...) {
	static HANDLE evlog = NULL;
	char msg[1024], *msgp = msg;
	va_list argv;
	
	if(!evlog && !(evlog = OpenEventLog(NULL, svc_log))) {
		return;
	}
	
	va_start(argv, fmt);
	vsnprintf(msg, 1024, fmt, argv);
	va_end(argv);
	
	ReportEvent(evlog, type, 0, id, NULL, 1, 0, (LPCSTR*)&msgp, NULL);
}

/* Log an error to the event log and exit */
void die_r(char const *file, int line, char const *fmt, ...) {
	char msg[1024];
	va_list argv;
	
	va_start(argv, fmt);
	vsnprintf(msg, 1024, fmt, argv);
	va_end(argv);
	
	LogError("Fatal error at %s:%d:\n%s", file, line, msg);
	
	svc_status.dwWin32ExitCode = 1;
	longjmp(exit_jmp, 1);
}