splitting m_flags to pkthdr.flags + m_flags

[Juli Mallett]

On Fri, Nov 2, 2012 at 5:54 AM, Andre Oppermann <oppermann at networx.ch>wrote:

> On 02.11.2012 13:38, Gleb Smirnoff wrote:
>
>> #define M_SKIP_FIREWALL 0x00004000 /* skip firewall processing */
>>
>
> This one should become an M_PROTO overlay.  It is only relevant within
> a protocol layer.


No, like M_PROMISC it needs to follow packets around throughout the stack,
and not conflict with anything else.  My memory of the details is a bit
hazy, but ipfw2 unfortunately does need the flag to not be something that
could be accidentally set or cleared by another protocol layer, and the
flag needs to persist.  Or did 8 years ago.

http://svnweb.freebsd.org/base?view=revision&revision=132274

But there was some disagreement at the time about whether ipfw2 was doing
the right thing, and this behavior should be legitimized by making it
actually work right:

http://lists.freebsd.org/pipermail/cvs-src/2004-July/027830.html

If the flag is made back into an M_PROTO (or, even better, removed) then it
would be best to verify that it does not need to persist, it is okay if the
flag is set by a different protocol layer, etc., today.

Thanks,
Juli.