Messages in this thread | | | Subject | Re: Linux Kernel -Doubt on sk_buff! | From | Andi Kleen <> | Date | 01 Mar 1999 15:04:05 +0100 |
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jalaja@teil.soft.net (G Jalaja Devi) writes:
> 1. When an IP packet is received from IP, do we get a chain of data ( as in > ifnet ) or is it a continuous buffer.
It is a continuous buffer. I find it curious that you use ifnet as a synonym for BSD.
> > 2. What is the use of the following fields in the sk_buff structure > 1. data_skb pointer. > 2. count. > 3. users.
data_skb points to the original skb for cloned skbs. count it is the reference count of the data portion users is how many users the skbuff header has.
[BTW in 2.2 data_skb is gone and a reference count is kept at the end of the data]
> > 3. If we have to send a particular IP packet ( which is in sk_buff format ) > to two diffrent destinations, do we have to duplicate the sk_buff. > Doesn't this reduce the performance. > Is there any other way to handle this case.
skb_clone(). It only duplicates the skbuff header, but not the packet data.
http://www.uk.linux.org/Documents/buffers.html may be helpful for more information.
-Andi
-- This is like TV. I don't like TV.
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