gistfile1.m

- (int)handleConnectAttempt:(int)socket addr:(const struct sockaddr *)addr addrlen:(socklen_t)addrlen {    
    static BOOL javaStackTestConnect = NO;
    
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    
    // Ignore the first connect() attempt (java test)
    static dispatch_once_t pred;
    dispatch_once(&pred, ^{javaStackTestConnect = YES;});
    if (javaStackTestConnect) {
        javaStackTestConnect = NO;
        return connectReentry(socket, addr, addrlen);
    }
    
    char serv[NI_MAXSERV];
    
    // If the socket is not for minecraft, return without doing anything...
    getnameinfo(addr, addrlen, NULL, 0, serv, NI_MAXSERV, NI_NUMERICSERV);
    int port = atoi(serv);
    if (port == 80) {
        return connectReentry(socket, addr, addrlen);
    }
    
    // if socket is non-blocking...
    BOOL wasNonBlocking = NO;
    int flags = fcntl(socket,F_GETFL);
    if (flags & O_NONBLOCK){
        wasNonBlocking = YES;
        fcntl(socket, F_SETFL, flags & ~O_NONBLOCK);
    }
    
    // Call the original connect()
    int retval = connectReentry(socket, addr, addrlen);
    
    // Steal the original file descriptor (to server)
    int original_fd = dup(socket);
    
    // Give the client sockpair[0] (closing socket)
    int sockpair[2];
    socketpair(AF_UNIX, SOCK_STREAM, 0, sockpair);
    dup2(sockpair[0], socket);
    
    // Uncomment this to disable proxy
    //dup2(original_fd, sockpair[1]);
    
    // If the socket was non-blocking...
    if (wasNonBlocking) {
        // ...fix the socket to its original state
        fcntl(socket, F_SETFL, O_NONBLOCK);
    }
        
    // Set up proxy
    MHProxyDescriptorPair pair = {sockpair[1], original_fd};
    NSValue *pairValue = [NSValue value:&pair withObjCType:@encode(MHProxyDescriptorPair)];
    
    [NSThread detachNewThreadSelector:@selector(proxyThreadMain:) toTarget:self withObject:pairValue];
    
    [pool drain];
    return retval;
}