In article [ref] (at Fri, 18 Apr 2003 14:10:14 -0700 (PDT)), "David S. Miller" [off-list ref] says:

I think it would be better if ipv6's upper-layer interface worked
like ipv4's.  ie. a < 0 return value means:

	next_proto =- ret;
	goto resubmit;

NO!  Please, don't do this again (for now, at least).
This idea is what we had introduced the bug,
that was fixed by "[IPV6]: Fixed multiple mistake extension header handling."

We need to get the offset of the next header, in addition to the value
itself.

inet6_protocol function will return:

  > 0: more header(s) follows; next header is pointed by skb->nh.raw[nhoff]
  = 0: stop parsing on success; increment the statistics (nhoff is undefined)
  < 0: stop parsing on failure (nhoff is undefined)

If upper-layer returns positive value, we continue parsing.
Then, if the skb->nh.raw[nhoff] is unknown, we send back the parameter problem 
message with the offset to the unrecognized next header field.

The less that is different between ipv4/ipv6 the better.

Agreed, but please note that IPv4 side would be required to be changed
in general.


Well... 

1) May we have a new member to point the offset of the next header in 
   ipv6_pinfo{}?
   Then, we can remove *nhoffp from argument of inet6_protocol function.
   (We will be cleaner handing of HbH option, too.)
2) change IPv4 upperlayer function to take struct sk_buff **.


If you are not in hurry, I'll take care of this.

-- 
Hideaki YOSHIFUJI @ USAGI Project [off-list ref]
GPG FP: 9022 65EB 1ECF 3AD1 0BDF  80D8 4807 F894 E062 0EEA