Mahesh Bandewar says:
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add 'private' and 'vepa' attributes to ipvlan modes
IPvlan has always been operating in bridge-mode for its supported modes i.e.
if the packets are destined to the adjacent neighbor dev, then IPvlan driver
will switch the packet internally without needing the packets to hit the
wire or get routed. However, there are situations where this bridge-mode is
not needed. e.g. two private processes running inside two namespaces which
are having one IPvlan slave each for its namespace but sharing the master. These
processes should reach the outside world through the master device but at
the same time the bridge function should not work. Currently that's not
possible hence the private attribute for the selected mode comes in play.
VEPA or 802.1Qbg on the other hand has limited appeal with IPvlan since IPvlan
uses the mac-address of the lower device. So packets that are destined to
the adjacent neighbor slave-dev will have same src and dest mac. When these
packets reach the external switch/router, they will send you the redirect
message which the host will have to deal with. Having said that this attribute
will have appeal in debugging as IPvlan will not switch / short-circuit
packets internally. e.g. using VEPA mode with lower-device in loopback mode
will avoid some complicated set-ups that use non-local-bind with some route
jugglery.
This patch-set implements these attributes for the existing modes that
IPvlan has. Please see individual patches for their detailed implementation.
A subsequent ip-utils patch is needed and will be sent soon.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>