Re: Ethernet Checksum

From: sai narasimhamurthy
Date: Tue May 03 2005 - 22:38:38 EST


I am thinking that you are referring to the RX ring
buffers(given below) ...when you said rx buffer
descriptor .....
Thanks
Sai


161 struct e1000_desc_ring {
162 /* pointer to the descriptor ring memory
*/
163 void *desc;
164 /* physical address of the descriptor ring
*/
165 dma_addr_t dma;
166 /* length of descriptor ring in bytes */
167 unsigned int size;
168 /* number of descriptors in the ring */
169 unsigned int count;
170 /* next descriptor to associate a buffer
with */
171 unsigned int next_to_use;
172 /* next descriptor to check for DD status
bit */
173 unsigned int next_to_clean;
174 /* array of buffer information structs */
175 struct e1000_buffer *buffer_info;
176 };



================================================================



--- warrier@xxxxxxxxxxx wrote:
> I'm not too sure about this but most chipsets write
> the received CRC at
> the end of the data buffer. You may want to dump the
> data as soon as you
> get an rx interrupt. The length in the rx buffer
> descriptor should tell
> you where the data ends. The next four bytes should
> be the CRC. I think
> ethereal may ignore this and only look at the data
> length.
>
> S
>
>
>
>
> sai narasimhamurthy <sai_narasi@xxxxxxxxx>
> Sent by: linux-net-owner@xxxxxxxxxxxxxxx
> 05/03/2005 05:52 PM
>
>
> To:
> cc:
> Subject: Ethernet Checksum
>
>
> I have an application which requires the recieved
> ethernet checksum. To begin with, I need to see if
> the
> ethernet checksum can be accessed at all. I was not
> able to view it in ethereal.
>
> How can I get access(or atleast get to see) the
> ethernet checksum at the reciever?
>
> I am in linux 2.4.29 , am using intel 82546 GBE.
>
> Sai
>
>
>
>
>
> __________________________________
> Do you Yahoo!?
> Yahoo! Small Business - Try our new resources site!
> http://smallbusiness.yahoo.com/resources/
> -
> To unsubscribe from this list: send the line
> "unsubscribe linux-net" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at
> http://vger.kernel.org/majordomo-info.html
>
>
>
>

__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
-
To unsubscribe from this list: send the line "unsubscribe linux-net" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html