kern/83499: fragmented packets does not pass through a pipe

[gul at itsinternet.net]

>Number:         83499
>Category:       kern
>Synopsis:       fragmented packets does not pass through a pipe
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Jul 15 09:30:11 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Pavel Gulchouck
>Release:        FreeBSD 5.4-STABLE i386
>Organization:
IT Systems
>Environment:
System: FreeBSD lamamba.itsinternet.net 5.4-STABLE FreeBSD 5.4-STABLE #1: Thu Jun 30 23:41:25 EEST 2005 root at lamamba.itsinternet.net:/usr/obj/usr/src/sys/LAMAMBA i386


	
>Description:
If I add line
add pipe 20 ip from any to any xmit fxp1
then transit packets passed through this rule losts. Not fragmented
packets processed correctly.
Without this rule both "ping -s 1500" and "ping -s 1472" works fine.
tcpdump shows in pipe case first part of packet followed by
the second part, I think it cause problem with reassembling.
I have no ipfw rules with "frag" flag.
>How-To-Repeat:
Create ipfw pipe and try to "ping -s 1500" though it.
It fails on my tests on RELENG_5 and RELENG_5_3, other versions
I did not test.
>Fix:
Now as workaround I pass all packets before pipe through divert socket
without altering for reassemble.

>Release-Note:
>Audit-Trail:
>Unformatted: