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Scott Feldman authored
The driver implements ndo_switch_fib_ipv4_add/del ops to add/del/mod IPv4 routes to/from switchdev device. Once a route is added to the device, and the route's nexthops are resolved to neighbor MAC address, the device will forward matching pkts rather than the kernel. This offloads the L3 forwarding path from the kernel to the device. Note that control and management planes are still mananged by Linux; only the data plane is offloaded. Standard routing control protocols such as OSPF and BGP run on Linux and manage the kernel's FIB via standard rtm netlink msgs...nothing changes here. A new hash table is added to rocker to track neighbors. The driver listens for neighbor updates events using netevent notifier NETEVENT_NEIGH_UPDATE. Any ARP table updates for ports on this device are recorded in this table. Routes installed to the device with nexthops that reference neighbors in this table are "qualified". In the case of a route with nexthops not resolved in the table, the kernel is asked to resolve the nexthop. The driver uses fib_info->fib_priority for the priority field in rocker's unicast routing table. The device can only forward to pkts matching route dst to resolved nexthops. Currently, the device only supports single-path routes (i.e. routes with one nexthop). Equal Cost Multipath (ECMP) route support will be added in followup patches. This patch is driver support for unicast IPv4 routing only. Followup patches will add driver and infrastructure for IPv6 routing and multicast routing. Signed-off-by:
Scott Feldman <sfeldma@gmail.com> Signed-off-by:
Jiri Pirko <jiri@resnulli.us> Signed-off-by:
David S. Miller <davem@davemloft.net>
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