TCP congestion window

[yi <yi@ece.utexas.edu>]

Dear all,
First, I apologize you for posing this message although I'm not on the list.

I have some questions. I made the following system call for getting tcp 
cwnd size of ongoing connection. However, I am always getting the value 
of "2", which is the initial tcp cwnd size, I think. What I really want 
to do is to trace tcp cwnd size when I download some big file using 
"wget"'s http file downloader. For it, I added a new system call shown 
below and modified the wget source code.

Please cc to me personally in reply. Thanks in advance.

Best Regards,
Yung Yi.

---------------------------------------------------------------------------
asmlinkage int sys_get_winsize(int sockfd)
{
    struct socket *sock;
    struct sock *sk;
    int err;
    sock = sockfd_lookup(sockfd, &err);

    if (!sock)
        return -1;

    sk = sock->sk;
    return sk->tp_pinfo.af_tcp.snd_cwnd;
}