IP header length in RAW IP packets

anu_subramanian at agilent.com anu_subramanian at agilent.com
Thu May 8 12:50:17 PDT 2003


I'm a new user of this mailing list. 

I'm using FreeBSD 4.4. I see that in ip_input, the IP header length is subtracted from the  length field in the IP header. For raw ip, rip_input does not seem to add that back when it passes the IP datagram to the user, i.e., it passes the datagram up with ip->ip_len = total length - header length. 

My question is: Why, if the IP header is passed up, does the length not reflect that?

Please let me know if I should've posted this elsewhere.

Many Thanks,

Anu Subramanian
Software Engineer
Agilent Technologies.

Tel: 603 559 5742 
Fax: 603 433 6891

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