net: mctp: test: Add extaddr routing output test

Test that the routing code preserves the haddr data in a skb through an
input route operation.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://patch.msgid.link/20250702-dev-forwarding-v5-6-1468191da8a4@codeconstruct.com.au
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/net/mctp/test/route-test.c b/net/mctp/test/route-test.c
index 7a1eba463fe7..3a1a686e36c3 100644
--- a/net/mctp/test/route-test.c
+++ b/net/mctp/test/route-test.c
@@ -1294,6 +1294,58 @@ static void mctp_test_route_output_key_create(struct kunit *test)
 	mctp_test_destroy_dev(dev);
 }
 
+static void mctp_test_route_extaddr_input(struct kunit *test)
+{
+	static const unsigned char haddr[] = { 0xaa, 0x55 };
+	struct mctp_test_pktqueue tpq;
+	struct mctp_skb_cb *cb, *cb2;
+	const unsigned int len = 40;
+	struct mctp_test_dev *dev;
+	struct sk_buff *skb, *skb2;
+	struct mctp_dst dst;
+	struct mctp_hdr hdr;
+	struct socket *sock;
+	int rc;
+
+	hdr.ver = 1;
+	hdr.src = 10;
+	hdr.dest = 8;
+	hdr.flags_seq_tag = FL_S | FL_E | FL_TO;
+
+	__mctp_route_test_init(test, &dev, &dst, &tpq, &sock, MCTP_NET_ANY);
+
+	skb = mctp_test_create_skb(&hdr, len);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, skb);
+
+	/* set our hardware addressing data */
+	cb = mctp_cb(skb);
+	memcpy(cb->haddr, haddr, sizeof(haddr));
+	cb->halen = sizeof(haddr);
+
+	mctp_test_skb_set_dev(skb, dev);
+
+	rc = mctp_dst_input(&dst, skb);
+	KUNIT_ASSERT_EQ(test, rc, 0);
+
+	mctp_test_dst_release(&dst, &tpq);
+
+	skb2 = skb_recv_datagram(sock->sk, MSG_DONTWAIT, &rc);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, skb2);
+	KUNIT_ASSERT_EQ(test, skb2->len, len);
+
+	cb2 = mctp_cb(skb2);
+
+	/* Received SKB should have the hardware addressing as set above.
+	 * We're likely to have the same actual cb here (ie., cb == cb2),
+	 * but it's the comparison that we care about
+	 */
+	KUNIT_EXPECT_EQ(test, cb2->halen, sizeof(haddr));
+	KUNIT_EXPECT_MEMEQ(test, cb2->haddr, haddr, sizeof(haddr));
+
+	skb_free_datagram(sock->sk, skb2);
+	mctp_test_destroy_dev(dev);
+}
+
 static struct kunit_case mctp_test_cases[] = {
 	KUNIT_CASE_PARAM(mctp_test_fragment, mctp_frag_gen_params),
 	KUNIT_CASE_PARAM(mctp_test_rx_input, mctp_rx_input_gen_params),
@@ -1310,6 +1362,7 @@ static struct kunit_case mctp_test_cases[] = {
 	KUNIT_CASE(mctp_test_fragment_flow),
 	KUNIT_CASE(mctp_test_route_output_key_create),
 	KUNIT_CASE(mctp_test_route_input_cloned_frag),
+	KUNIT_CASE(mctp_test_route_extaddr_input),
 	{}
 };