CVS commit: [netbsd-8] src/sys/netinet

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Wed Oct 17 13:38:04 UTC 2018

Modified Files:
        src/sys/netinet [netbsd-8]: ip_reass.c

Log Message:
Pull up following revision(s) (requested by maxv in ticket #1045):

        sys/netinet/ip_reass.c: revision 1.19-1.21

Hold ip_off and ip_len in the fragment entry, instead of always reading
the associated mbuf (and converting to host order). This reduces the
cache/TLB misses when processing long lists.

 -

Kick fragments that would introduce several !MFFs in a reassembly chain.

The problem arises if we receive three fragments of the kind
        3.  A -> has MFF
        1.  B -> doesn't have MFF
        2.  C -> doesn't have MFF

Because of the received order B->C->A, we don't see that B is !MFF, and
therefore that there is a problem in this chain.

Now we do two checks, and drop us if:

 * there is a fragment preceding us, and this fragment is !MFF, or
 * there is a fragment following us, and we are !MFF

Spotted a long time ago.

 -

Force ip_off to zero when the reassembly is complete. This was lost in my
rev1.19 - before that the IP struct was clobbered for the reassembly, but
it actually implicitly guaranteed that the first fragment of the packet
would end up with ip_off = 0, and this was a desired behavior.


To generate a diff of this commit:
cvs rdiff -u -r1.11.8.6 -r1.11.8.7 src/sys/netinet/ip_reass.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.