Merge branch 'net-mctp-add-support-for-gateway-routing'

Jeremy Kerr says:

====================
net: mctp: Add support for gateway routing

This series adds a gateway route type for the MCTP core, allowing
non-local EIDs as the match for a route.

Example setup using the mctp tools:

    mctp route add 9 via mctpi2c0
    mctp neigh add 9 dev mctpi2c0 lladdr 0x1d
    mctp route add 10 gw 9

- will route packets to eid 10 through mctpi2c0, using a dest lladdr
of 0x1d (ie, that of the directly-attached eid 9).

The core change to support this is the introduction of a struct
mctp_dst, which represents the result of a route lookup. Since this
involves a bit of surgery through the routing code, we add a few tests
along the way.

We're introducing an ABI change in the new RTM_{NEW,GET,DEL}ROUTE
netlink formats, with the support for a RTA_GATEWAY attribute. Because
we need a network ID specified to fully-qualify a gateway EID, the
RTA_GATEWAY attribute carries the (net, eid) tuple in full:

    struct mctp_fq_addr {
        unsigned int net;
        mctp_eid_t eid;
    }

Of course, any questions, comments etc are most welcome.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
====================

Link: https://patch.msgid.link/20250702-dev-forwarding-v5-0-1468191da8a4@codeconstruct.com.au
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/net/mctp/test/utils.h b/net/mctp/test/utils.h
index df6aa1c03440..f10d1d9066cc 100644
--- a/net/mctp/test/utils.h
+++ b/net/mctp/test/utils.h
@@ -3,6 +3,11 @@
 #ifndef __NET_MCTP_TEST_UTILS_H
 #define __NET_MCTP_TEST_UTILS_H
 
+#include <uapi/linux/netdevice.h>
+
+#include <net/mctp.h>
+#include <net/mctpdevice.h>
+
 #include <kunit/test.h>
 
 #define MCTP_DEV_TEST_MTU	68
@@ -10,11 +15,50 @@
 struct mctp_test_dev {
 	struct net_device *ndev;
 	struct mctp_dev *mdev;
+
+	unsigned short lladdr_len;
+	unsigned char lladdr[MAX_ADDR_LEN];
 };
 
 struct mctp_test_dev;
 
+struct mctp_test_route {
+	struct mctp_route	rt;
+};
+
+struct mctp_test_pktqueue {
+	unsigned int magic;
+	struct sk_buff_head pkts;
+};
+
 struct mctp_test_dev *mctp_test_create_dev(void);
+struct mctp_test_dev *mctp_test_create_dev_lladdr(unsigned short lladdr_len,
+						  const unsigned char *lladdr);
 void mctp_test_destroy_dev(struct mctp_test_dev *dev);
 
+struct mctp_test_route *mctp_test_create_route_direct(struct net *net,
+						      struct mctp_dev *dev,
+						      mctp_eid_t eid,
+						      unsigned int mtu);
+struct mctp_test_route *mctp_test_create_route_gw(struct net *net,
+						  unsigned int netid,
+						  mctp_eid_t eid,
+						  mctp_eid_t gw,
+						  unsigned int mtu);
+void mctp_test_dst_setup(struct kunit *test, struct mctp_dst *dst,
+			 struct mctp_test_dev *dev,
+			 struct mctp_test_pktqueue *tpq, unsigned int mtu);
+void mctp_test_dst_release(struct mctp_dst *dst,
+			   struct mctp_test_pktqueue *tpq);
+void mctp_test_pktqueue_init(struct mctp_test_pktqueue *tpq);
+void mctp_test_route_destroy(struct kunit *test, struct mctp_test_route *rt);
+void mctp_test_skb_set_dev(struct sk_buff *skb, struct mctp_test_dev *dev);
+struct sk_buff *mctp_test_create_skb(const struct mctp_hdr *hdr,
+				     unsigned int data_len);
+struct sk_buff *__mctp_test_create_skb_data(const struct mctp_hdr *hdr,
+					    const void *data, size_t data_len);
+
+#define mctp_test_create_skb_data(h, d) \
+	__mctp_test_create_skb_data(h, d, sizeof(*d))
+
 #endif /* __NET_MCTP_TEST_UTILS_H */