XXX: complete this section
-L3 routing
-----------
+L3 Routing Offload
+------------------
Offloading L3 routing requires that device be programmed with FIB entries from
the kernel, with the device doing the FIB lookup and forwarding. The device
does a longest prefix match (LPM) on FIB entries matching route prefix and
-forwards the packet to the matching FIB entry's nexthop(s) egress ports. To
-program the device, the switchdev driver is called with add/delete ops for IPv4
-and IPv6 FIB entries. For IPv4, the driver implements switchdev ops:
-
- int (*switchdev_fib_ipv4_add)(struct net_device *dev,
- __be32 dst, int dst_len,
- struct fib_info *fi,
- u8 tos, u8 type,
- u32 nlflags, u32 tb_id);
-
- int (*switchdev_fib_ipv4_del)(struct net_device *dev,
- __be32 dst, int dst_len,
- struct fib_info *fi,
- u8 tos, u8 type,
- u32 tb_id);
-
-to add/delete IPv4 dst/dest_len prefix on table tb_id. The *fi structure holds
-details on the route and route's nexthops. *dev is one of the port netdevs
-mentioned in the routes next hop list. If the output port netdevs referenced
-in the route's nexthop list don't all have the same switch ID, the driver is
-not called to add/delete the FIB entry.
+forwards the packet to the matching FIB entry's nexthop(s) egress ports.
+
+To program the device, the driver implements support for
+SWITCHDEV_OBJ_IPV[4|6]_FIB object using switchdev_port_obj_xxx ops.
+switchdev_port_obj_add is used for both adding a new FIB entry to the device,
+or modifying an existing entry on the device.
+
+XXX: Currently, only SWITCHDEV_OBJ_IPV4_FIB objects are supported.
+
+SWITCHDEV_OBJ_IPV4_FIB object passes:
+
+ struct switchdev_obj_ipv4_fib { /* IPV4_FIB */
+ u32 dst;
+ int dst_len;
+ struct fib_info *fi;
+ u8 tos;
+ u8 type;
+ u32 nlflags;
+ u32 tb_id;
+ } ipv4_fib;
+
+to add/modify/delete IPv4 dst/dest_len prefix on table tb_id. The *fi
+structure holds details on the route and route's nexthops. *dev is one of the
+port netdevs mentioned in the routes next hop list. If the output port netdevs
+referenced in the route's nexthop list don't all have the same switch ID, the
+driver is not called to add/modify/delete the FIB entry.
Routes offloaded to the device are labeled with "offload" in the ip route
listing:
12.0.0.4 via 11.0.0.9 dev sw1p2 proto zebra metric 20 offload
192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.15
-XXX: add/del IPv6 FIB API
+XXX: add/mod/del IPv6 FIB API
Nexthop Resolution
^^^^^^^^^^^^^^^^^^
}
/**
- * switchdev_fib_ipv4_add - Add IPv4 route entry to switch
+ * switchdev_fib_ipv4_add - Add/modify switch IPv4 route entry
*
* @dst: route's IPv4 destination address
* @dst_len: destination address length (prefix length)
* @nlflags: netlink flags passed in (NLM_F_*)
* @tb_id: route table ID
*
- * Add IPv4 route entry to switch device.
+ * Add/modify switch IPv4 route entry.
*/
int switchdev_fib_ipv4_add(u32 dst, int dst_len, struct fib_info *fi,
u8 tos, u8 type, u32 nlflags, u32 tb_id)