tree d385b74ac144c06e11e70e2ace08b00b3433d77f
parent e5a55a898720096f43bc24938f8875c0a1b34cd7
author John Fastabend <john.r.fastabend@intel.com> 1351066383 +0000
committer David S. Miller <davem@davemloft.net> 1351703909 -0400

net: set and query VEB/VEPA bridge mode via PF_BRIDGE

Hardware switches may support enabling and disabling the
loopback switch which puts the device in a VEPA mode defined
in the IEEE 802.1Qbg specification. In this mode frames are
not switched in the hardware but sent directly to the switch.
SR-IOV capable NICs will likely support this mode I am
aware of at least two such devices. Also I am told (but don't
have any of this hardware available) that there are devices
that only support VEPA modes. In these cases it is important
at a minimum to be able to query these attributes.

This patch adds an additional IFLA_BRIDGE_MODE attribute that can be
set and dumped via the PF_BRIDGE:{SET|GET}LINK operations. Also
anticipating bridge attributes that may be common for both embedded
bridges and software bridges this adds a flags attribute
IFLA_BRIDGE_FLAGS currently used to determine if the command or event
is being generated to/from an embedded bridge or software bridge.
Finally, the event generation is pulled out of the bridge module and
into rtnetlink proper.

For example using the macvlan driver in VEPA mode on top of
an embedded switch requires putting the embedded switch into
a VEPA mode to get the expected results.

	--------  --------
        | VEPA |  | VEPA |       <-- macvlan vepa edge relays
        --------  --------
           |        |
           |        |
        ------------------
        |      VEPA      |       <-- embedded switch in NIC
        ------------------
                |
                |
        -------------------
        | external switch |      <-- shiny new physical
	-------------------          switch with VEPA support

A packet sent from the macvlan VEPA at the top could be
loopbacked on the embedded switch and never seen by the
external switch. So in order for this to work the embedded
switch needs to be set in the VEPA state via the above
described commands.

By making these attributes nested in IFLA_AF_SPEC we allow
future extensions to be made as needed.

CC: Lennert Buytenhek <buytenh@wantstofly.org>
CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>