Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269466AbTGVE24 (ORCPT ); Tue, 22 Jul 2003 00:28:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269439AbTGVE24 (ORCPT ); Tue, 22 Jul 2003 00:28:56 -0400 Received: from magic-mail.adaptec.com ([208.236.45.100]:35254 "EHLO magic.adaptec.com") by vger.kernel.org with ESMTP id S269409AbTGVE2w (ORCPT ); Tue, 22 Jul 2003 00:28:52 -0400 Date: Tue, 22 Jul 2003 10:48:00 +0530 (IST) From: Nagendra Singh Tomar X-X-Sender: tomar@localhost.localdomain Reply-To: nagendra_tomar@adaptec.com To: yi cc: linux-kernel@vger.kernel.org, Subject: Re: TCP congestion window In-Reply-To: <3F1C6406.5040009@ece.utexas.edu> Message-ID: Organization: Adaptec MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2068 Lines: 63 Yi, First of all networking related questions should go to linux-net@vger.kernel.org. Now for ur question. cwnd has got significance in the sending side of a TCP connection. Its the sender that keeps changing the cwnd based on the ACKs recvd. If you are using wget for downloading a file and you are expecting cwnd to change on the wget side, then the answer is that since wget is *only* receiving data, cwnd will not change on wget side. It will change on the other side. If you are checking for cwnd on the other side then please ignore my answer. Thanx tomar On Tue, 22 Jul 2003, yi wrote: > 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; > } > > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" > in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/