Re: raw socket, IP_HDRINCL byteorder

On Thu, Sep 26, 2002 at 06:19:39PM +0900, [email protected] wrote:

> 	how about this.  all fields are in network byteorder.
> 
> 	outgoing:
> 	ip_len: the whole IP packet length (not the payload)
> 	ip_off: offset portion and MF bit has to be zero.
> 	ip_id: overwritten by the kernel
> 	ip_sum: overwritten by the kernel
> 	ip option: ???? interaction with IP_OPTIONS?

IMO, the outgoing packet shouldn't be touched at all - just written
as-is to the wire. the proposed restriction on ip_off is problematic
for applications which need to create IP fragments, and there are
several awful workarounds people have had to resort to to acheive
this, for example, on Solaris.

> 	incoming:
> 	ip_len: the whole IP packet length (not the payload) = as is
> 	ip_off: as is (same as the packet on the wire)
> 	ip_id: as is (same as the packet on the wire)
> 	ip_sum: as is (same as the packet on the wire)
> 	ip option: as is (same as the packet on the wire)

looks great! :-)

-d.

---
http://www.monkey.org/~dugsong/

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