/************************************************************************
 *   IRC - Internet Relay Chat, win32/debug.c
 *   Copyright (C) 2002-2004 Dominick Meglio (codemastr)
 *   
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 1, or (at your option)
 *   any later version.
 *
 *   This program 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, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "setup.h"
#ifdef INET6
#include <winsock2.h>
#include <ws2tcpip.h>
#endif
#include <windows.h>
#include <dbghelp.h>
#include "struct.h"
#include "h.h"
#include "proto.h"
#include "version.h"
#include <string.h>
#ifndef IRCDTOTALVERSION
#define IRCDTOTALVERSION BASE_VERSION PATCH1 PATCH2 PATCH3 PATCH4 PATCH5 PATCH6 PATCH7 PATCH8 PATCH9
#endif
#define BUFFERSIZE   0x200

extern OSVERSIONINFO VerInfo;
extern char OSName[256];
extern char backupbuf[8192];
extern char *buildid;
extern char serveropts[];
extern char *extraflags;
extern BOOL IsService;
void CleanUp(void);

/* Runs a stack trace 
 * Parameters:
 *  e - The exception information
 * Returns:
 *  The stack trace with function and line number information
 */
__inline char *StackTrace(EXCEPTION_POINTERS *e) 
{
	static char buffer[5000];
	char curmodule[32];
	DWORD symOptions, dwDisp, frame;
	HANDLE hProcess = GetCurrentProcess();
	IMAGEHLP_SYMBOL *pSym = malloc(sizeof(IMAGEHLP_SYMBOL)+500);
	IMAGEHLP_LINE pLine;
	IMAGEHLP_MODULE pMod;
	STACKFRAME Stack;

	/* Load the stack information */
	Stack.AddrPC.Offset = e->ContextRecord->Eip;
	Stack.AddrPC.Mode = AddrModeFlat;
	Stack.AddrFrame.Offset = e->ContextRecord->Ebp;
	Stack.AddrFrame.Mode = AddrModeFlat;
	if (VerInfo.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS)
		hProcess = (HANDLE)GetCurrentProcessId();
	else
		hProcess = GetCurrentProcess();	

	/* Initialize symbol retrieval system */
	SymInitialize(hProcess, NULL, TRUE);
	SymSetOptions(SYMOPT_LOAD_LINES|SYMOPT_UNDNAME);
	bzero(pSym, sizeof(IMAGEHLP_SYMBOL)+500);
	pSym->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL);
	pSym->MaxNameLength = 500;
	bzero(&pLine, sizeof(IMAGEHLP_LINE));
	pLine.SizeOfStruct = sizeof(IMAGEHLP_LINE);
	bzero(&pMod, sizeof(IMAGEHLP_MODULE));
	pMod.SizeOfStruct = sizeof(IMAGEHLP_MODULE);

	/* Retrieve the first module name */
	SymGetModuleInfo(hProcess, Stack.AddrPC.Offset, &pMod);
	strcpy(curmodule, pMod.ModuleName);
	sprintf(buffer, "\tModule: %s\n", pMod.ModuleName);

	/* Walk through the stack */
	for (frame = 0; ; frame++) 
	{
		char buf[500];
		if (!StackWalk(IMAGE_FILE_MACHINE_I386, GetCurrentProcess(), GetCurrentThread(),
			&Stack, NULL, NULL, SymFunctionTableAccess, SymGetModuleBase, NULL))
			break;
		SymGetModuleInfo(hProcess, Stack.AddrPC.Offset, &pMod);
		if (strcmp(curmodule, pMod.ModuleName)) 
		{
			strcpy(curmodule, pMod.ModuleName);
			sprintf(buf, "\tModule: %s\n", pMod.ModuleName);
			strcat(buffer, buf);
		}
		SymGetLineFromAddr(hProcess, Stack.AddrPC.Offset, &dwDisp, &pLine);
		SymGetSymFromAddr(hProcess, Stack.AddrPC.Offset, &dwDisp, pSym);
		sprintf(buf, "\t\t#%d %s:%d: %s\n", frame, pLine.FileName, pLine.LineNumber, 
		        pSym->Name);
		strcat(buffer, buf);
	}
	return buffer;

}

/* Retrieves the values of several registers
 * Parameters:
 *  context - The CPU context
 * Returns:
 *  The values of the EAX/EBX/ECX/EDX/ESI/EDI/EIP/EBP/ESP registers
 */
__inline char *GetRegisters(CONTEXT *context) 
{
	static char buffer[1024];

	sprintf(buffer, "\tEAX=0x%08x EBX=0x%08x ECX=0x%08x\n"
			"\tEDX=0x%08x ESI=0x%08x EDI=0x%08x\n"
			"\tEIP=0x%08x EBP=0x%08x ESP=0x%08x\n",
		context->Eax, context->Ebx, context->Ecx, context->Edx,
		context->Esi, context->Edi, context->Eip, context->Ebp,
		context->Esp);
	return buffer;
}

/* Convert the exception code to a human readable string
 * Parameters:
 *  code - The exception code to convert
 * Returns:
 *  The exception code represented as a string
 */
__inline char *GetException(DWORD code) 
{
	switch (code) 
	{
		case EXCEPTION_ACCESS_VIOLATION:
			return "Access Violation";
		case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
			return "Array Bounds Exceeded";
		case EXCEPTION_BREAKPOINT:
			return "Breakpoint";
		case EXCEPTION_DATATYPE_MISALIGNMENT:
			return "Datatype Misalignment";
		case EXCEPTION_FLT_DENORMAL_OPERAND:
			return "Floating Point Denormal Operand";
		case EXCEPTION_FLT_DIVIDE_BY_ZERO:
			return "Floating Point Division By Zero";
		case EXCEPTION_FLT_INEXACT_RESULT:
			return "Floating Point Inexact Result";
		case EXCEPTION_FLT_INVALID_OPERATION:
			return "Floating Point Invalid Operation";
		case EXCEPTION_FLT_OVERFLOW:
			return "Floating Point Overflow";
		case EXCEPTION_FLT_STACK_CHECK:
			return "Floating Point Stack Overflow";
		case EXCEPTION_FLT_UNDERFLOW:
			return "Floating Point Underflow";
		case EXCEPTION_ILLEGAL_INSTRUCTION:
			return "Illegal Instruction";
		case EXCEPTION_IN_PAGE_ERROR:
			return "In Page Error";
		case EXCEPTION_INT_DIVIDE_BY_ZERO:
			return "Integer Division By Zero";
		case EXCEPTION_INT_OVERFLOW:
			return "Integer Overflow";
		case EXCEPTION_INVALID_DISPOSITION:
			return "Invalid Disposition";
		case EXCEPTION_NONCONTINUABLE_EXCEPTION:
			return "Noncontinuable Exception";
		case EXCEPTION_PRIV_INSTRUCTION:
			return "Unallowed Instruction";
		case EXCEPTION_SINGLE_STEP:
			return "Single Step";
		case EXCEPTION_STACK_OVERFLOW:
			return "Stack Overflow";
		default:
			return "Unknown Exception";
	}
}

/* Callback for the exception handler
 * Parameters:
 *  e - The exception information
 * Returns:
 *  EXCEPTION_EXECUTE_HANDLER to terminate the process
 * Side Effects:
 *  wircd.PID.core is created
 *  If not running in service mode, a message box is displayed, 
 *   else output is written to service.log
 */
LONG __stdcall ExceptionFilter(EXCEPTION_POINTERS *e) 
{
	MEMORYSTATUS memStats;
	char file[512], text[1024];
	FILE *fd;
	time_t timet = time(NULL);

	sprintf(file, "wircd.%d.core", getpid());
	fd = fopen(file, "w");
	GlobalMemoryStatus(&memStats);
	fprintf(fd, "Generated at %s\n%s (%d.%d.%d)\n%s[%s%s%s] (%s)\n"
		    "-----------------\nMemory Information:\n"
		    "\tPhysical: (Available:%ldMB/Total:%ldMB)\n"
		    "\tVirtual: (Available:%ldMB/Total:%ldMB)\n"
		    "-----------------\nException:\n\t%s\n-----------------\n"
		    "Backup Buffer:\n\t%s\n-----------------\nRegisters:\n"
		    "%s-----------------\nStack Trace:\n%s",
		     asctime(gmtime(&timet)), OSName, VerInfo.dwMajorVersion,
		     VerInfo.dwMinorVersion, VerInfo.dwBuildNumber, IRCDTOTALVERSION,
		     serveropts, extraflags ? extraflags : "", tainted ? "3" : "",
		     buildid, memStats.dwAvailPhys/1048576, memStats.dwTotalPhys/1048576, 
		     memStats.dwAvailVirtual/1048576, memStats.dwTotalVirtual/1048576, 
		     GetException(e->ExceptionRecord->ExceptionCode), backupbuf, 
		     GetRegisters(e->ContextRecord), StackTrace(e));

	sprintf(text, "UnrealIRCd has encountered a fatal error. Debugging information has"
		      " been dumped to wircd.%d.core, please email this file to "
		      "coders@lists.unrealircd.org.", getpid());
	fclose(fd);

	if (!IsService)
		MessageBox(NULL, text, "Fatal Error", MB_OK);
	else 
	{
		FILE *fd = fopen("service.log", "a");

		fprintf(fd, "UnrealIRCd has encountered a fatal error. Debugging information "
			    "has been dumped to wircd.%d.core, please email this file to "
			    "coders@lists.unrealircd.org.", getpid());
		fclose(fd);
	}
	CleanUp();
	return EXCEPTION_EXECUTE_HANDLER;
}

/* Initializes the exception handler */
void InitDebug(void) 
{
	SetUnhandledExceptionFilter(&ExceptionFilter);
}


