From: Ido Schimmel <ido...@mellanox.com> Date: Sat, 14 Jul 2018 11:39:50 +0300
> When a router that is acting as the default gateway of a host stops > functioning, the host will encounter packet loss until the router starts > functioning again. > > To increase the reliability of the default gateway without performing > reconfiguration on the host, a host can use a Virtual Router Redundancy > Protocol (VRRP) Router. This virtual router is composed from several > routers where only one is actually forwarding packets from the host (the > master router) while the other routers act as backup routers. The > election of the master router is determined by the VRRP protocol [1]. > > Packets addressed to the virtual router are always sent to the virtual > router MAC address (IPv4: 00-00-5E-00-01-XX, IPv6: 00-00-5E-00-02-XX). > Such packets can only be accepted by the master router and must be > discarded by the backup routers. > > In Linux, VRRP is usually implemented by configuring a macvlan with the > virtual router MAC on top of the router interface that is connected to > the host / LAN. The macvlan on the master router is assigned the virtual > IP (VIP) that the host uses as its gateway. > > In order to support VRRP in mlxsw, we first need to enable macvlan upper > devices on top of mlxsw netdevs and their uppers. This is done by the > first patch, which also takes care of sanitizing macvlan configurations > that are not currently supported by the driver. > > The second patch directs packets with destination MAC addresses as the > macvlans to the router so that they will undergo an L3 lookup. This is > consistent with the kernel's behavior where the macvlan's Rx handler > will re-inject such packets to the Rx path so that they will be picked > up by the IPvX protocol handlers and undergo an L3 lookup. Note that the > driver prevents the macvlans from being enslaved to other devices, to > ensure the packets will be picked up by the protocol handler and not by > another Rx handler. > > The third patch adds packet traps for VRRP control packets for both IPv4 > and IPv6. Finally, the last patch optimizes the reception of VRRP MACs > by potentially skipping one L2 lookup for them. Series applied, thank you.
