iOS IPv4 trace

+ (NSString *)makeTrace:(const char *)address :(int)ttl_t :(int)timeout
{
    struct hostent *host_entry = gethostbyname(address);

    if(host_entry == nil || host_entry->h_addr_list == 0)
    {
        return nil;
    }

    char *ip_addr = inet_ntoa(*((struct in_addr *)host_entry->h_addr_list[0]));
    struct sockaddr_in destination, fromAddr;
    int recv_sock;
    int send_sock;

    if((recv_sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP)) < 0)
    {
        return nil;
    }

    if((send_sock = socket(AF_INET , SOCK_DGRAM, IPPROTO_IP)) < 0)
    {
        return nil;
    }

    int ttl = (int)ttl_t;

    memset(&destination, 0, sizeof(destination));
    destination.sin_family = AF_INET;
    destination.sin_addr.s_addr = inet_addr(ip_addr);
    destination.sin_port = htons(33434);

    struct timeval tv;
    tv.tv_sec = timeout / 1000;
    tv.tv_usec = (timeout % 1000) * 1000;

    if(setsockopt(recv_sock, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv, sizeof(struct timeval)) < 0)
    {
        return nil;
    }

    NSTimeInterval timeInSeconds = [[NSDate date] timeIntervalSince1970];
    NSString *timestamp = [NSString stringWithFormat:@"%f", timeInSeconds];
    const char *cmsg = [timestamp UTF8String];
    socklen_t n = sizeof(fromAddr);
    int buffer_size = BUFFER_SIZE;
    void *buffer;
    buffer = malloc(buffer_size);
    memset(&fromAddr, 0, sizeof(fromAddr));

    if(setsockopt(send_sock, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) < 0)
    {
        return nil;
    }

    if(sendto(send_sock, cmsg, sizeof(cmsg), 0, (struct sockaddr *) &destination,sizeof(destination)) != sizeof(cmsg))
    {
        return nil;
    }

    ssize_t bytesRead = recvfrom(recv_sock, buffer, buffer_size, 0, (struct sockaddr *)&fromAddr, &n);

    if(setsockopt(recv_sock, SOL_SOCKET, SO_RCVBUF, &buffer_size, sizeof(buffer_size)) < 0)
    {
        return nil;
    }

    NSString *result = nil;

    if(bytesRead > 0)
    {
        char display[INET_ADDRSTRLEN]= {0};
        inet_ntop(AF_INET, &fromAddr.sin_addr.s_addr, display, sizeof (display));
        //@"Received packet from%s for TTL=%d\n";//, display;
        result = [NSString stringWithCString:display encoding:NSUTF8StringEncoding];
    }

    close(send_sock);
    close(recv_sock);
    free(buffer);
    return result;
}