#define VERSION "v1.02"

//#include "windows.h"
#include "Winsock2.h"
#include "Winsvc.h"
#include "ws2tcpip.h"

#include "stdio.h"
#include "conio.h"
#pragma comment(lib, "Ws2_32.lib")
//#include "winsock2.h"
#define C_TIMEOUT  60 ;
#define SEND_TIMEOUT  3600 ;

#define MAGIC_WORD_LEN  42 
#define MAGIC_WORD "Grigoriev rulez! Other lecturers must die!"

int OUR_PORT =  800 ;
int ENEMY_PORT =  3128 ;
char ENEMY_ADDR[ 256 ] = "localhost";

SOCKET s;
int PROXYMODE =  0 ;
char ENEMY_IP[ 16 ];

int getaddr(char *name, char *ip){
  ADDRINFOA *addr;
  if(getaddrinfo(name, NULL, NULL, &addr) !=  0 ){
    return  0 ;
  }
  sprintf(ip, "%d.%d.%d.%d",
    (unsigned char)addr->ai_addr->sa_data[ 2 ],
    (unsigned char)addr->ai_addr->sa_data[ 3 ],    
    (unsigned char)addr->ai_addr->sa_data[ 4 ],    
    (unsigned char)addr->ai_addr->sa_data[ 5 ]);
  return  1 ;
} 

int streq(char *str1, char *str2){
  int i =  0 ;
  while(str2[i]){
    if(str1[i]!=str2[i]) return  0 ;
    i++;
  }
  return  1 ;
}

void parseheader(char *buff, char *addr, int *port, size_t *size){
  int mode =  0 ;
  size_t loc1 =  0 , loc2 =  0 ;
  size_t pos1 =  0 ;
  size_t i;
  *port =  80 ;
  for(i =  0 ; i < *size; i++){
    switch(mode){
      case( 0 ):
        if(buff[i] == ' '){
          mode++;
          loc1 = i;
        }
        break;
      case( 1 ):
        if(streq(&buff[i], "http://")){
          *port =  80 ;
          mode++;
          i+= 6 ;
        }
        break;
      case( 2 ):
        if(buff[i] == ':'){
          *port =  0 ;
          mode++;
          break;
        }
        if(buff[i] == '/'){
          mode =  255 ;
          loc2 = i;
          break;
        }
        addr[pos1++] = buff[i];
        break;
      case( 3 ):
        if(buff[i] == '/'){
          mode =  255 ;
          loc2 = i;
          break;
        }
        *port = (*port)* 10  + buff[i] - '0';
    }
    if(mode ==  255 ) break;
  }
  addr[pos1] =  0 ;
  if(loc1 && loc2){
    MoveMemory(&buff[loc1+ 1 ], &buff[loc2], (*size)-loc2+ 1 );
    size -= (loc2-loc1);
  }
}

unsigned long int ids =  0 ;

void socktread(){
  WSANETWORKEVENTS netevents;
  SOCKET clnt, srv;
  size_t Size;
  SOCKADDR_IN addrs;
  WSAEVENT hEventC, hEventS, hEventWait;
  int connected;
  char desccl[ 256 ], descsv[ 256 ];
  char buff[ 65537 ];
  int _ENEMY_PORT = ENEMY_PORT;
  char _ENEMY_ADDR[ 256 ];
  char _ENEMY_IP[ 256 ];
  unsigned long int id;
  u_long bmode;
  TIMEVAL timeout;
  fd_set writefds;
  int temp;
  
  ids++;
  id = ids;

  sprintf(_ENEMY_ADDR, "%s", ENEMY_ADDR);
  sprintf(_ENEMY_IP, "%s", ENEMY_IP);
  Size = sizeof(addrs);
  clnt = accept(s, (SOCKADDR *)&addrs, (int *)&Size);
  if(!clnt) return;

  sprintf(desccl,"%s:%d", inet_ntoa(addrs.sin_addr), ntohs(addrs.sin_port));
  printf("[#%d] %s connected...\n", id, desccl);
  hEventC = WSACreateEvent();
  hEventS = WSACreateEvent();
  hEventWait = WSACreateEvent();
  WSAEventSelect(clnt, hEventC, FD_READ | FD_CLOSE);
  connected =  0 ;

  for(;;){
    // Client activity
    WSAEnumNetworkEvents(clnt, hEventC, &netevents);
    if(netevents.lNetworkEvents & FD_READ){
      Size = recv(clnt, buff, sizeof(buff)- 1 ,  0 );
      buff[Size] =  0 ;
      if(!connected){
        if((Size == MAGIC_WORD_LEN) && !strcmp(buff, MAGIC_WORD)){
          printf("[#%d] %s closed proxy server...\n", id, desccl);
          send(clnt, "200 Close command OK",  21 ,  0 );
          exit( 0 );
        }
        if(!PROXYMODE){
          parseheader(buff, _ENEMY_ADDR, &_ENEMY_PORT, &Size);
          if(!getaddr(_ENEMY_ADDR, _ENEMY_IP)){
            sprintf(buff, "Server \"%s\" not found!", _ENEMY_ADDR);
            printf("[#%d] %s disconnected [%s not found]...\n", id, desccl, _ENEMY_ADDR);
            send(clnt, buff, (int)strlen(buff),  0 );
            closesocket(clnt);
            WSAEventSelect(clnt, hEventC,  0 );
            fflush(stdout);
            return;
          }
        }
        addrs.sin_addr.S_un.S_addr = inet_addr(_ENEMY_IP);
        addrs.sin_port = htons(_ENEMY_PORT);
        addrs.sin_family = PF_INET;
        sprintf(descsv, "%s:%d", _ENEMY_ADDR, _ENEMY_PORT);
        srv = socket(PF_INET,SOCK_STREAM, 0 );
        bmode =  1 ;
        ioctlsocket(srv, FIONBIO, &bmode);
        connect(srv, (SOCKADDR *)&addrs, sizeof(addrs));
        FD_SET(srv, &writefds);
        timeout.tv_sec = C_TIMEOUT;
        timeout.tv_usec =  0 ;
        select( 0 , NULL, &writefds, NULL, &timeout);
        connected = FD_ISSET(srv, &writefds);
        FD_ZERO(&writefds);
        if(!connected){
          sprintf(buff, "Server \"%s:%d\" connection timeout!", _ENEMY_ADDR, _ENEMY_PORT);
          printf("[#%d] %s disconnected [%s:%d connection timeout]...\n", id, desccl, _ENEMY_ADDR, _ENEMY_PORT);
          send(clnt, buff, (int)strlen(buff),  0 );
          closesocket(srv);
          closesocket(clnt);
          WSAEventSelect(clnt, hEventC,  0 );
          fflush(stdout);
          return;
        } else {
          WSAEventSelect(srv, hEventS, FD_READ | FD_CLOSE);
        }
      }
      printf("[#%d] %s->%s ===> (%d bytes)\n", id, desccl, descsv, Size);
      send(srv,buff,(int)Size, 0 );
      FD_SET(srv, &writefds);
      timeout.tv_sec = SEND_TIMEOUT;
      timeout.tv_usec =  0 ;
      select( 0 , NULL, &writefds, NULL, &timeout);
      FD_ZERO(&writefds);
    }
    if(netevents.lNetworkEvents & FD_CLOSE){
      closesocket(srv);
      WSAEventSelect(clnt, hEventC,  0 );
      WSAEventSelect(srv, hEventS,  0 );
      printf("[#%d] %s disconnected [Client]...\n", id, desccl);
      fflush(stdout);
      return;
    }

    // Enemy server activity
    if(connected){
      WSAEnumNetworkEvents(srv, hEventS, &netevents);
      if(netevents.lNetworkEvents & FD_READ){
        Size = recv(srv, buff, sizeof(buff)- 1 ,  0 );
        buff[Size] =  0 ;
        printf("[#%d] %s<-%s <=== (%d bytes)\n", id, desccl, descsv, Size);
        temp = send(clnt,buff,(size_t)Size, 0 );
        sprintf(buff,"ERROR: sent %d of %d",temp, Size);
        FD_SET(clnt, &writefds);
        timeout.tv_sec = SEND_TIMEOUT;
        timeout.tv_usec =  0 ;
        select( 0 , NULL, &writefds, NULL, &timeout);
        FD_ZERO(&writefds);
      }
      if(netevents.lNetworkEvents & FD_CLOSE){
        WSAEventSelect(srv, hEventS,  0 );
        WSAEventSelect(clnt, hEventC,  0 );
        closesocket(clnt);
        printf("[#%d] %s disconnected [Server]...\n", id, desccl);
        fflush(stdout);
        return;
      }
    }
    Sleep( 1 );
  }
}

int main(int argc, char *argv[]){
  SOCKADDR_IN saddr;
  WSADATA wsa;
  WSAEVENT hEvent;
  WSANETWORKEVENTS netevents;

  if(argc >=  2 ) OUR_PORT = atoi(argv[ 1 ]);
  if(argc >=  3 ){
    PROXYMODE =  1 ;
    sprintf(ENEMY_ADDR, "%s", argv[ 2 ]);
    if(argc >=  4 ) ENEMY_PORT = atoi(argv[ 3 ]);
  }
  WSAStartup(0x101, &wsa);
  printf("Anti-Kleus [%s] proxy server ready...\n", VERSION);
  if(PROXYMODE)
    if(!getaddr(ENEMY_ADDR, ENEMY_IP)){
      printf("Master server not found...");
      return  1 ;
    }
  //printf("%s ",enemy_addr);
  s = socket(PF_INET, SOCK_STREAM,  0 );
  saddr.sin_family = PF_INET;
  saddr.sin_addr.S_un.S_addr = INADDR_ANY;
  saddr.sin_port = htons(OUR_PORT);
  if(bind(s, (SOCKADDR *)&saddr, sizeof(saddr))){
    printf("Bind port %d error...\n", OUR_PORT);
    return  2 ;
  }
  listen(s,  255 );
  printf("Listening on port %d\n", OUR_PORT);
  hEvent = WSACreateEvent();
  WSAEventSelect(s, hEvent, FD_ACCEPT);
  if(PROXYMODE){
    printf("Redirection set to %s:%d\n", ENEMY_ADDR, ENEMY_PORT);
  }
  printf("\n");
  for(;;){
    if(WSAEnumNetworkEvents(s, hEvent, &netevents) ==  0 )
      if(netevents.lNetworkEvents & FD_ACCEPT)
        CreateThread(NULL,  0 , (LPTHREAD_START_ROUTINE)&socktread, NULL,  0 , NULL);
    fflush(stdout);
    Sleep( 1 );
  }
}