mangler.cpp

Go to the documentation of this file.

/*
**  Command & Conquer Generals Zero Hour(tm)
**  Copyright 2025 Electronic Arts Inc.
**
**  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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
*/
 
 
#include <iostream.h>
#include <signal.h>
#ifdef _WINDOWS
#include <process.h> // *MUST* be included before ANY Wnet/Wlib headers if _REENTRANT is defined
#endif
 
#include "mangler.h"
#include "crc.h"
#include "endian.h"
 
#include <configfile.h>
#include "threadfac.h"
 
#include "xtime.h"
#include <filed.h>
#include <wstring.h>
#include <wdebug.h>
#include <udp.h>
 
void DisplayHelp(const char *prog)
{
    cout << "Usage: " << prog << " <config file>" << endl;
    exit(0);
}
 
int main(int argc, char **argv)
{
    ConfigFile config;
    FILE*   conf;
    
    if( argc <= 1 )
    {
        // No args - use a default config file
        if ((conf = fopen("mangler.cfg", "r")) == NULL) {
            cout << "Cannot open mangler.cfg for reading." << endl;
            DisplayHelp(argv[0]);
        }
        config.readFile(conf);
        fclose(conf);
    }
    else if( argc == 2 && (strcmp(argv[1], "help") == 0 || strcmp(argv[1], "?") == 0 ||
        strcmp(argv[1], "-h") == 0) )
        DisplayHelp(argv[0]);
    else if( argc == 2 )
    {
        // Use a user-supplied config file
        if ((conf = fopen(argv[1], "r")) == NULL) {
            cout << "Cannot open " << argv[1] << " for reading." << endl;
            DisplayHelp(argv[0]);
        }
        config.readFile(conf);
        fclose(conf);
    }
    
    // ----- LOGGING -----
    // Setup debugging & logging output
    Wstring output_file("mangler.log");
    config.getString("LOGFILE", output_file);
    Wstring backup_file;
    backup_file = output_file;
    backup_file += ".bak";
    rename(output_file.get(),backup_file.get());  // save the old file
    FileD   output_device(output_file.get());
    MsgManager::setAllStreams(&output_device);
    DBGMSG("DBG working...");
    INFMSG("INF working...");
    WRNMSG("WRN working...");
    
    if (htonl(0x12345678) == 0x12345678)
    {
        INFMSG("Host is network-byte-order");
    }
    else
    {
        INFMSG("Host is Intel-byte-order");
    }
    
    
    // ----- Initialize Winsock -----
#ifdef _WINDOWS
    WORD verReq = MAKEWORD(2, 2);
    WSADATA wsadata;
    
    int err = WSAStartup(verReq, &wsadata);
    if (err != 0) {
        ERRMSG("Winsock Init failed.");
        return 1;
    }
    
    if ((LOBYTE(wsadata.wVersion) != 2) || (HIBYTE(wsadata.wVersion) !=2)) {
        ERRMSG("Winsock DLL is not 2.2");
        WSACleanup();
        ERRMSG("Winsock Init failed.");
        return 1;
    }
    INFMSG("Winsock Init done.");
#endif
    
    
    // Set up a UDP listener
    uint8  *buff=new uint8[1024];
    int     retval;
    UDP     udp;
    UDP     udp2;
    UDP     udp3;
    UDP     udp4;
    int     port = 4321;
    config.getInt("PORT", port);
    uint8 blitz = 0;
 
    uint32 localIP = 0;
    Wstring hostIPStr = "";
    config.getString("IP", hostIPStr);
    if (hostIPStr.length())
    {
        INFMSG("Binding to "<<hostIPStr.get()<<":"<<port<<"-"<<(port+3));
        localIP = ntohl(inet_addr(hostIPStr.get()));
    }
    else
    {
        INFMSG("Binding to localhost:"<<port<<"-"<<(port+3));
    }
 
    retval  =  udp.Bind(localIP,(uint16)port);
    retval |= udp2.Bind(localIP,(uint16)port+1);
    retval |= udp3.Bind(localIP,(uint16)port+2);
    retval |= udp4.Bind(localIP,(uint16)port+3);
    if (retval != 0)
    {
        ERRMSG("Couldn't bind - error " << retval);
        exit(1);
    }
    
    unsigned char buf[1024];
    struct sockaddr_in addr;
    int packet_size = sizeof(ManglerData);
    INFMSG("sizeof(packet) == " << packet_size);
    unsigned char *theAddr;
    fd_set fdset;
    while (1)
    {
        retval = udp.Wait(15, 0, fdset);
        if (!retval)
            continue;
        
        //DBGMSG("Wait returned " << retval);
        retval = udp.Read(buf, packet_size, &addr);        // Wait until there is something on the socket
        if (retval > 0)
        {
            ManglerData *packet = (ManglerData *)buf;
            theAddr = (unsigned char *)&(addr.sin_addr.s_addr);
            if (retval != packet_size)
            {
                WRNMSG("Recieved mis-sized packet (" << retval << " bytes) from " << theAddr[0] << "." << theAddr[1] << "." << theAddr[2] << "." << theAddr[3] << ":" << addr.sin_port);
            }
            else
            {
                if (!Passes_CRC_Check(buf, packet_size))
                {
                    WRNMSG("Recieved a bad packet - good length!");
                    continue;
                }
                packet->NetCommandType = 44;
                packet->MyMangledPortNumber = addr.sin_port; // not changing to host order, cause its in network byte order now, and the game will expect it to stay that way.
                packet->MyMangledAddress[0] = theAddr[0];
                packet->MyMangledAddress[1] = theAddr[1];
                packet->MyMangledAddress[2] = theAddr[2];
                packet->MyMangledAddress[3] = theAddr[3];
                blitz = packet->BlitzMe;
                INFMSG("Packet ID = " << packet->packetID);
                Build_Packet_CRC(buf, packet_size);
                udp.Write(buf,packet_size,ntohl(addr.sin_addr.s_addr), ntohs(addr.sin_port));
                INFMSG("Saw " << (int)theAddr[0] << "." << (int)theAddr[1] << "." << (int)theAddr[2] << "." << (int)theAddr[3] << ":" << ntohs(addr.sin_port) << ((blitz)?" Blitzed":"") );
                
                if (blitz)
                {
                    udp2.Write(buf,packet_size,ntohl(addr.sin_addr.s_addr), ntohs(addr.sin_port)+1);
                    udp3.Write(buf,packet_size,ntohl(addr.sin_addr.s_addr), ntohs(addr.sin_port)+2);
                    udp4.Write(buf,packet_size,ntohl(addr.sin_addr.s_addr), ntohs(addr.sin_port)+3);
                }
            }
        }
    }
    
    
    return 0;
}