From ad39c12fcee34b8980a80ad5c803bca9906fbd4e Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Wed, 2 Jul 2025 14:20:13 +0800 Subject: net: mctp: add gateway routing support This change allows for gateway routing, where a route table entry may reference a routable endpoint (by network and EID), instead of routing directly to a netdevice. We add support for a RTM_GATEWAY attribute for netlink route updates, with an attribute format of: struct mctp_fq_addr { unsigned int net; mctp_eid_t eid; } - we need the net here to uniquely identify the target EID, as we no longer have the device reference directly (which would provide the net id in the case of direct routes). This makes route lookups recursive, as a route lookup that returns a gateway route must be resolved into a direct route (ie, to a device) eventually. We provide a limit to the route lookups, to prevent infinite loop routing. The route lookup populates a new 'nexthop' field in the dst structure, which now specifies the key for the neighbour table lookup on device output, rather than using the packet destination address directly. Signed-off-by: Jeremy Kerr Link: https://patch.msgid.link/20250702-dev-forwarding-v5-13-1468191da8a4@codeconstruct.com.au Signed-off-by: Paolo Abeni --- include/uapi/linux/mctp.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/mctp.h b/include/uapi/linux/mctp.h index e1db65df9359..19ad12a0cd4b 100644 --- a/include/uapi/linux/mctp.h +++ b/include/uapi/linux/mctp.h @@ -37,6 +37,14 @@ struct sockaddr_mctp_ext { __u8 smctp_haddr[MAX_ADDR_LEN]; }; +/* A "fully qualified" MCTP address, which includes the system-local network ID, + * required to uniquely resolve a routable EID. + */ +struct mctp_fq_addr { + unsigned int net; + mctp_eid_t eid; +}; + #define MCTP_NET_ANY 0x0 #define MCTP_ADDR_NULL 0x00 -- cgit v1.2.3