kern/185629: IP Filter reports "bad" packets on fxp interface with tso4

[Cy Schubert (cy)]

>Number:         185629
>Category:       kern
>Synopsis:       IP Filter reports "bad" packets on fxp interface with tso4
>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 Jan 10 05:20:00 UTC 2014
>Closed-Date:
>Last-Modified:
>Originator:     Cy Schubert (cy)
>Release:        FreeBSD 10.0-BETA3 amd64
>Organization:
FreeBSD.org
>Environment:
System: FreeBSD slippy 10.0-BETA3 FreeBSD 10.0-BETA3 #0 r258761M: Tue Dec 3 00:04:57 PST 2013 root at slippy:/export/obj/amd64.amd64/opt/src/svn-stable10/sys/BREAK amd64


>Description:
On firewall/gateway system with four NICs, fxp0 on DMZ, with tcp4 option set,
TCP sessions hang, ipmon reports,

	

Investigate the possibility of this being related to kern/106438.
>How-To-Repeat:
Open an SSH tunnel, using tun(4) interface, through gateway machine and
initaite an rsync through the interface.

Client side of interface using bge(4) has no problem.
>Fix:

Circumvention is to turn off tcp4 option when using fxp interface. However
I will be working on a solution to fix this.

I will assign the PR to myself once it has been registered with GNATS.
>Release-Note:
>Audit-Trail:
>Unformatted: