Received: with ECARTIS (v1.0.0; list netdev); Mon, 31 Jan 2005 02:56:13 -0800 (PST) Received: from rproxy.gmail.com (rproxy.gmail.com [64.233.170.192]) by oss.sgi.com (8.13.0/8.13.0) with ESMTP id j0VAu7LE004118 for ; Mon, 31 Jan 2005 02:56:07 -0800 Received: by rproxy.gmail.com with SMTP id b11so748900rne for ; Mon, 31 Jan 2005 02:56:07 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding; b=rwfntCUG1nSYl6MUVf0Qmtq12+mR8e6nowri5LymKn7U/0wlnie9J4mi6SuxHC5J8n1GINRCzrQYQc05JZbhvqsBAXVmouQyJaew83Z79GanrLGIOauiYkQcbxiAtAwCJZJavKgebLr17OPZ7fL859U83/RIFyCWdiLOX7Lv++4= Received: by 10.38.9.30 with SMTP id 30mr56403rni; Mon, 31 Jan 2005 02:56:06 -0800 (PST) Received: by 10.38.81.57 with HTTP; Mon, 31 Jan 2005 02:56:06 -0800 (PST) Message-ID: <1d55641b050131025636a00d1e@mail.gmail.com> Date: Mon, 31 Jan 2005 16:26:06 +0530 From: cranium 2003 Reply-To: cranium 2003 To: kernelnewbies@nl.linux.org, netdev@oss.sgi.com Subject: ethernet cache question Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV 0.80/650/Sun Jan 2 19:00:02 2005 clamav-milter version 0.80j on 127.0.0.1 X-Virus-Status: Clean X-archive-position: 1069 X-ecartis-version: Ecartis v1.0.0 Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com X-original-sender: cranium.2003@gmail.com Precedence: bulk X-list: netdev Content-Length: 554 Lines: 12 Hello, By looking at structure hh_cache it is seen that hh_output is structure variable defined as unsigned long hh_data[HH_DATA_ALIGN(LL_MAX_HEADER) / sizeof(long)]; Then i want to know how its sufficient in linux kernel to copy cache ethernet header entry as memcpy(skb->data - 16, hh->hh_data, 16); other variable defined in hh_cache is not seen as copied to packet structure. How then ethernet header is copied to packet if ethernet header has cache entry stored in hh_cache structure defiend in /usr/src/include/netdevice.h regards, cranium