a problem about non-linear sk_buff

a problem about non-linear sk_buff

[Jianyong Zhang]

Hi,

  I'm a newcomer of this list.  I want to understand the tcp/ip stack's
implementaion, and hope that I can get your help.

  I find that that sk_buff can be fragmented, and it's called nonlinear.
What's the meaning of nonlinear?  And what are the meaning of sk_buff's
fields: skb->data_len and skb_shinfo(skb)?  I have no idea about them.
May you explain them?  Thank you.

Jianyong Zhang

Re: a problem about non-linear sk_buff

[Evgeniy Polyakov]

On Tue, 9 Oct 2001 23:51:17 -0400 (EDT)
Jianyong Zhang <jzhang@cse.psu.edu> wrote:

JZ> Hi,

JZ> I'm a newcomer of this list.  I want to understand the tcp/ip stack's
JZ> implementaion, and hope that I can get your help.

kernlel-net is also good for this kind of questions.

JZ> I find that that sk_buff can be fragmented, and it's called nonlinear.
JZ> What's the meaning of nonlinear?  And what are the meaning of
sk_buff's

May be because of MTU?

JZ> fields: skb->data_len and skb_shinfo(skb)?  I have no idea about them.

As I've right understood it from 
www.linux.org.uk/Documents/buffers.html (excellent Alan's book)
http://kernelnewbies.org/documents/ipnetworking/linuxipnetworking.html
(the best source of documentation fobeginners)
and skbuff.h
skb->data_len is actuall length of the data( that is all packet length -
header length).

skb_shinfo(skb) returns structure that containig number of fragments, list
of it, and some other( what? ).

JZ> May you explain them?  Thank you.

I'm trying, but it can be absolutelly wrong :)

JZ> Jianyong Zhang

Evgeniy Polyakov.
---
WBR. //s0mbre

Re: a problem about non-linear sk_buff

[Evgeniy Polyakov]

On Tue, 9 Oct 2001 23:51:17 -0400 (EDT)
Jianyong Zhang <jzhang@cse.psu.edu> wrote:

JZ> Hi,

JZ> I'm a newcomer of this list.  I want to understand the tcp/ip stack's
JZ> implementaion, and hope that I can get your help.

kernlel-net is also good for this kind of questions.

JZ> I find that that sk_buff can be fragmented, and it's called nonlinear.
JZ> What's the meaning of nonlinear?  And what are the meaning of
sk_buff's

May be because of MTU?

JZ> fields: skb->data_len and skb_shinfo(skb)?  I have no idea about them.

As I've right understood it from 
www.linux.org.uk/Documents/buffers.html (excellent Alan's book)
http://kernelnewbies.org/documents/ipnetworking/linuxipnetworking.html
(the best source of documentation fobeginners)
and skbuff.h
skb->data_len is actuall length of the data( that is all packet length -
header length).

skb_shinfo(skb) returns structure that containig number of fragments, list
of it, and some other( what? ).

JZ> May you explain them?  Thank you.

I'm trying, but it can be absolutelly wrong :)

JZ> Jianyong Zhang

Evgeniy Polyakov.
---
WBR. //s0mbre