source: Daodan/MSVC/Daodan_Update.c@ 750

#include <stdlib.h>
#include <stdio.h>
#include <string.h>


#include <WinSock2.h>
#include <Windows.h>

#include "Daodan.h"
#include "Daodan_Utility.h"
#include "Flatline_Net.h"

#pragma comment(lib, "wininet.lib")

#define DAODAN_BUILD 3

int file_exists(const char *fname)
{
    FILE *file;
    if (file = fopen(fname, "r"))
    {
        fclose(file);
        return 1;
    }
    return 0;
}

void DDr_StartupNetworkError()
{
        int errorno = WSAGetLastError();
        char Message[1024];
        FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS |
                FORMAT_MESSAGE_MAX_WIDTH_MASK, NULL, errorno,
                MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                (LPSTR) Message, 1024, NULL);

        DDrStartupMessage(Message);
#ifdef _DEBUG
        MessageBox(0, Message, "", 0);
#endif
}

char* DDr_HttpGet( char* host, char* path )
{
        #define chunkSize 8192
        char* file = 0;
        char tempRaw[chunkSize] = {0};
        char* rawData = 0;
        char* filePtr;
        char* sizePtr;
        int rawLen = 0;
        int tempLen = 0;
        char getString[255];
        sockaddr_in UpdateAddr = {0};
        int UpdateSocket;
        hostent* host_info = 0;
        struct timeval tv;
        tv.tv_sec = 5;
        tv.tv_usec = 0;
        sprintf(getString, "GET %s HTTP/1.0\r\n"
                 "User-Agent: Daodan DLL Updater\r\n"
                 "Host: %s\r\n"
                 "\r\n"
                 , path, host );
        
        host_info = gethostbyname(host);

        if(!host_info)
        {
                DDr_StartupNetworkError();
                return 0;
        }

        UpdateAddr.sin_port = htons(80);
        UpdateAddr.sin_family = AF_INET;
        UpdateAddr.sin_addr.S_un.S_addr = *(ULONG*)host_info->h_addr_list[0];

        UpdateSocket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP) ;
        
        if(UpdateSocket <= 0)
        {
                DDrStartupMessage("Could not create socket");
                DDr_StartupNetworkError();
                return 0;
        }

        //Set timeout to five seconds.
        setsockopt(UpdateSocket, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv,  sizeof tv);

        if (connect(UpdateSocket, (struct sockaddr *) &UpdateAddr, sizeof(sockaddr_in)) < 0)
        {
                closesocket( UpdateSocket );
                DDr_StartupNetworkError();
                return 0;
        }

        
        send( UpdateSocket, getString, strlen(getString), 0 );

        while((tempLen = recv( UpdateSocket, tempRaw, chunkSize, 0 )) > 0)
        {
                rawLen += tempLen;
                rawData = (char*)realloc( rawData, rawLen + 1 );
                if(rawData == 0)
                {
                        closesocket( UpdateSocket );
                        return 0;
                }
                memcpy( rawData + rawLen - tempLen, tempRaw, tempLen );
        }

        closesocket( UpdateSocket );
        
        if(tempLen < 0)
        {
                return 0;
        }

        //check for complete header
        filePtr = strstr( rawData, "\r\n\r\n" ) + 4;
        //get the data size
        sizePtr = strstr( rawData, "Content-Length:") + strlen("Content-Length:");
        //check for correct status code
        if(filePtr > 4 && sizePtr && !strncmp("HTTP/1.0 200 OK", rawData, 15))
        {
                int fileSize = atoi(sizePtr);
                file = (char*)malloc( fileSize + sizeof(int) + 1);
                if(file)
                {
                        *(int *)file = fileSize;
                        memcpy( file + 4, filePtr, fileSize );
                        file[fileSize + sizeof(int)] = 0;
                }
        }
        else
        {
                if(sizePtr && filePtr) *(filePtr + atoi(sizePtr)) = 0;
#ifdef _DEBUG
                MessageBox( 0, rawData, "", 0);
#endif
                DDrStartupMessage("HTML Error!");
                DDrStartupMessage( rawData );
        }
        free( rawData );
        return file;
        #undef chunkSize
}

int DDr_CheckForUpdates(int argc, char* argv[])
{
        int version = 0;
        char* fileGet;
        char args[8191] = {0};
        int i;
        WSADATA wsaData;

        for(i = 1; i < argc; i++)
        {
                if(!stricmp(argv[i], "-noupdate")) return 1;
                strcat( args, " ");
                strcat( args, argv[i] );

        }

        //Start network stuff
        
        if (WSAStartup(MAKEWORD(2, 2), &wsaData))
        {
                DDrStartupMessage("WSA initalization failed");
                return 0;
        }
        DDrStartupMessage("net started using WSA version %d.%d", LOBYTE(wsaData.wVersion), HIBYTE(wsaData.wVersion));

        fileGet = DDr_HttpGet( "gumby.oni2.net", "/daodan/version.txt" );
        
        if(fileGet && *(int*)fileGet)
        {
                version = atoi(fileGet + sizeof(int));
        }
        free( fileGet );
        
        if(version > DAODAN_BUILD)
        {
                FILE* dllFile;
                char pName[8191] = {0};
                int returnval = 0;
                STARTUPINFO siStartupInfo; 
                PROCESS_INFORMATION piProcessInfo; 
                memset(&siStartupInfo, 0, sizeof(siStartupInfo)); 
                memset(&piProcessInfo, 0, sizeof(piProcessInfo)); 
                siStartupInfo.cb = sizeof(siStartupInfo); 

                DDrStartupMessage("Update for the Daodan DLL is avaliable...");
                returnval = MessageBox( NULL, "An update for the Daodan DLL is avaiable! Would you like to download it?", "Daodan DLL Alert", MB_YESNO);
                if( returnval != IDYES) return 1;
                MessageBox( NULL, "Update downloading, please do not reopen Oni, it will open itself.\nPress OK to continue", "Daodan DLL Alert", 0);
                fileGet = DDr_HttpGet( "gumby.oni2.net", "/daodan/binkw32.dll" );
                if(!(fileGet && *(int*)fileGet))
                {
                        free(fileGet);
                        return 0;
                }

                //Remove the old file
                remove( "binkw32.dll.bak" );
                rename( "binkw32.dll", "binkw32.dll.bak" );
                //rename failed!
                if(file_exists("binkw32.dll")) return;

                //write the new file
                dllFile = fopen( "binkw32.dll", "wb" );
                if(dllFile == NULL )
                {
                        rename( "binkw32.dll.bak", "binkw32.dll" );
                        return 0;
                }
                
                fwrite( fileGet + 4, *(int *)fileGet, 1, dllFile );
                fclose( dllFile );
                
                free(fileGet);
                //Restart Oni!

                GetModuleFileName(NULL, pName, 8191 );
                //GetProcessImageFileName()
                //GetProcessImageFileName( 0, pName, 8191 );
                CreateProcess(pName, args, 0, 0, 0, 0, 0, 0,&siStartupInfo,&piProcessInfo);

                exit(0);

                
        }
        return 1;
}