EtherIP: Fix passing the address family from if_bridge(4) to gif(4)HEADmain

Given IPPROTO_IPV4, IPPROTO_IPV6 and IPPROTO_ETHERIP have different
protocol numbers, then it is perfect valid to tunnel IPv4, IPv6 and
Ethernet traffic over IPv[46] by the same interface. Since gif(4) has
already utilized the inbound csum_data field to carry address family,
also teach if_bridge(4) to do that, rather than checking if a gif(4)
interface is member of a if_bridge(4) interface.

Without this fix, tunnel IPv[46] over IPv[46] will not work when the
gif(4) interface is member of a if_bridge(4) interface, aka the EtherIP
setup, as the address family passed from gif_output() will be overwritten
with the wrong one AF_LINK by gif_transmit(), and end up with incorrectly
encapsulated packets.

PR:		227450
Reviewed by:	kp
Tested by:	meta
Fixes:		8a0308722372 gif(4): Assert that gif_output() isn't called for EtherIP
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D51682

0 files changed, 0 insertions, 0 deletions