loopback packet processing.

loopback packet processing.

[Harshal Nemade]

Hi all,
       I want to know that when i send a packet on loopback on
127.0.0.1 the packet is given to netif_rx without MAC header adding. I
want to know Is that correct? If yes then what happen to that 14 byte
MAC header bytes space in case Ping packet? Is that space free? Why
eth_type_trans is called that checks eth->h_proto field ?
     Please correct me if i am wrong.
Thanks in advance,
harsh.

Re: loopback packet processing.

[Harsh]

Hi MANJUNATH,
         I actually did a lot work on kernel packet processing and 
found that ping packet creation enters in ethernet.c.
           Also can you tell me what happens in ip_finish_output2 when
ping ICMP packet is created by kernel? what header is added there.
            Also in receving end control enters in ethernet.c to check
eth->h_proto field which is ETH_P_IP. How & where it is added by
kernel in case of PING packet?

regards,
Harsh.

On Tue, 14 Dec 2004 16:53:33 +0530 (IST), MANJUNATH
<manjunath@ece.iisc.ernet.in> wrote:
> 
> 
> Hi,
> 
>   When u send data to the loopback address, control never
>   Enters "ethernet" modules.(Data link layer)
> 
>   Since ping inturn uses program interface to ICMP which is a part
>   of IPV4 s/w, for loopback ping IP modules themselves replies. Ethernet
>   does not come into picture.
> 
> cheers,
> Manjunath
> 
>