drivers "tag packets" with an m_tag and the input packet handling recognizes
such packets and does the right thing
o track the number of active vlans on an interface; this lets lots of places
only do vlan-specific processing when needed
o track changes to ether_ifdetach/ether_ifattach
o track bpf changes
o eliminate the use of M_PROTO1 for communicating to drivers about tagged
packets
o eliminate the use of IFF_LINK0 for drivers communicating to the vlan code
that they support h/w tagging; replaced by explicit interface capabilities
o add ifnet capabilities for h/w tagging and support of "large mtu's"
o use new interface capabilities to auto-configure use of large mtu's and h/w
tagging
o add support for proper handling of promiscuous mode
o document driver/vlan communication conventions
Reviewed by: many
Approved by: re
a3814acf84