From 03c0566542f4c7a45ce3193f27cbf5700b506c18 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 3 Mar 2015 19:13:56 -0600 Subject: mpls: Netlink commands to add, remove, and dump routes This change adds two new netlink routing attributes: RTA_VIA and RTA_NEWDST. RTA_VIA specifies the specifies the next machine to send a packet to like RTA_GATEWAY. RTA_VIA differs from RTA_GATEWAY in that it includes the address family of the address of the next machine to send a packet to. Currently the MPLS code supports addresses in AF_INET, AF_INET6 and AF_PACKET. For AF_INET and AF_INET6 the destination mac address is acquired from the neighbour table. For AF_PACKET the destination mac_address is specified in the netlink configuration. I think raw destination mac address support with the family AF_PACKET will prove useful. There is MPLS-TP which is defined to operate on machines that do not support internet packets of any flavor. Further seem to be corner cases where it can be useful. At this point I don't care much either way. RTA_NEWDST specifies the destination address to forward the packet with. MPLS typically changes it's destination address at every hop. For a swap operation RTA_NEWDST is specified with a length of one label. For a push operation RTA_NEWDST is specified with two or more labels. For a pop operation RTA_NEWDST is not specified or equivalently an emtpy RTAN_NEWDST is specified. Those new netlink attributes are used to implement handling of rt-netlink RTM_NEWROUTE, RTM_DELROUTE, and RTM_GETROUTE messages, to maintain the MPLS label table. rtm_to_route_config parses a netlink RTM_NEWROUTE or RTM_DELROUTE message, verify no unhandled attributes or unhandled values are present and sets up the data structures for mpls_route_add and mpls_route_del. I did my best to match up with the existing conventions with the caveats that MPLS addresses are all destination-specific-addresses, and so don't properly have a scope. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller --- include/uapi/linux/rtnetlink.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h index 5cc5d66bf519..bad65550ae3e 100644 --- a/include/uapi/linux/rtnetlink.h +++ b/include/uapi/linux/rtnetlink.h @@ -303,6 +303,8 @@ enum rtattr_type_t { RTA_TABLE, RTA_MARK, RTA_MFC_STATS, + RTA_VIA, + RTA_NEWDST, __RTA_MAX }; @@ -344,6 +346,12 @@ struct rtnexthop { #define RTNH_SPACE(len) RTNH_ALIGN(RTNH_LENGTH(len)) #define RTNH_DATA(rtnh) ((struct rtattr*)(((char*)(rtnh)) + RTNH_LENGTH(0))) +/* RTA_VIA */ +struct rtvia { + __kernel_sa_family_t rtvia_family; + __u8 rtvia_addr[0]; +}; + /* RTM_CACHEINFO */ struct rta_cacheinfo { -- cgit v1.2.3