kern/61215: off-by-one error likely in ip_fragment()

[David Gilbert]

>>>>> "Andre" == Andre Oppermann <andre at freebsd.org> writes:

>>  I'm not sure what's up.  Your patch wouldn't apply to v1.17 of my
>> if_gre.c, so something's wrong with the patch.  Regardless, I
>> applied the patch by hand and things didn't work yet.

Andre> Didn't it apply because of patch complaining or because it
Andre> didn't match at all?

It looked like it was mostly whitespace errors or somesuch.  The patch
algorythm couldn't find the are to patch.

... however, as I said... I was able to patch it by hand.

>> The kernel didn't crash, but packets routed into the tunnel didn't
>> show up on the outbound interface.  I my case, the machine has
>> three ethernet-like interfaces and the gre.
>> 
>> wi0 and sis0 are internal networks.  dc0 is the external network
>> interface.  A /32 route for the far end of the tunnel exists (and
>> works on the new kernel ... it pings), but pings into the tunnel
>> don't generate traffic on dc0 (at least according to tcpdump).

Andre> Do you enable "link1" on your GRE interface?

What does link1 do to gre?  It hasn't been necessary before.

Andre> What does ifconfig -a show?

Ifconfig -a output was normal.  I didn't save the new output, but the
old output is the same ... save the fact that the new output prints
the tunnel endpoints.

gre0: flags=9011<UP,POINTOPOINT,LINK0,MULTICAST> mtu 1476
        inet6 fe80::2d0:9ff:fee4:bbc2%gre0 prefixlen 64 scopeid 0x5 
        inet 66.246.133.114 --> 66.246.133.113 netmask 0xfffffffc 

Dave.

-- 
============================================================================
|David Gilbert, Independent Contractor.       | Two things can only be     |
|Mail:       dave at daveg.ca                    |  equal if and only if they |
|http://daveg.ca                              |   are precisely opposite.  |
=========================================================GLO================