Commit 80bea9ac authored by Magnus Karlsson's avatar Magnus Karlsson Committed by Alexei Starovoitov
Browse files

selftests/xsk: add test when some packets are XDP_DROPed 



Add a new test where some of the packets are not passed to the AF_XDP
socket and instead get a XDP_DROP verdict. This is important as it
tests the recycling mechanism of the buffer pool. If a packet is not
sent to the AF_XDP socket, the buffer the packet resides in is instead
recycled so it can be used again without the round-trip to user
space. The test introduces a new XDP program that drops every other
packet.

Signed-off-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
Acked-by: default avatarMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-13-magnus.karlsson@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent f0a249df

tools/testing/selftests/bpf/progs/xsk_xdp_progs.c

+11 −0
Original line number Diff line number Diff line
@@ -11,9 +11,20 @@ struct { 
	__uint(value_size, sizeof(int));

} xsk SEC(".maps");



static unsigned int idx;



SEC("xdp") int xsk_def_prog(struct xdp_md *xdp)

{

	return bpf_redirect_map(&xsk, 0, XDP_DROP);

}



SEC("xdp") int xsk_xdp_drop(struct xdp_md *xdp)

{

	/* Drop every other packet */

	if (idx++ % 2)

		return XDP_DROP;



	return bpf_redirect_map(&xsk, 0, XDP_DROP);

}



char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/xskxceiver.c

+31 −0
Original line number Diff line number Diff line
@@ -1646,6 +1646,34 @@ static void testapp_invalid_desc(struct test_spec *test) 
	pkt_stream_restore_default(test);

}



static void testapp_xdp_drop(struct test_spec *test)

{

	struct ifobject *ifobj = test->ifobj_rx;

	int err;



	test_spec_set_name(test, "XDP_DROP_HALF");

	xsk_detach_xdp_program(ifobj->ifindex, ifobj->xdp_flags);

	err = xsk_attach_xdp_program(ifobj->xdp_progs->progs.xsk_xdp_drop, ifobj->ifindex,

				     ifobj->xdp_flags);

	if (err) {

		printf("Error attaching XDP_DROP program\n");

		test->fail = true;

		return;

	}



	pkt_stream_receive_half(test);

	testapp_validate_traffic(test);



	pkt_stream_restore_default(test);

	xsk_detach_xdp_program(ifobj->ifindex, ifobj->xdp_flags);

	err = xsk_attach_xdp_program(ifobj->xdp_progs->progs.xsk_def_prog, ifobj->ifindex,

				     ifobj->xdp_flags);

	if (err) {

		printf("Error restoring default XDP program\n");

		exit_with_error(-err);

	}

}



static int xsk_load_xdp_programs(struct ifobject *ifobj)

{

	ifobj->xdp_progs = xsk_xdp_progs__open_and_load();
@@ -1796,6 +1824,9 @@ static void run_pkt_test(struct test_spec *test, enum test_mode mode, enum test_ 
	case TEST_TYPE_HEADROOM:

		testapp_headroom(test);

		break;

	case TEST_TYPE_XDP_DROP_HALF:

		testapp_xdp_drop(test);

		break;

	default:

		break;

	}

tools/testing/selftests/bpf/xskxceiver.h

+1 −0
Original line number Diff line number Diff line
@@ -87,6 +87,7 @@ enum test_type { 
	TEST_TYPE_STATS_RX_FULL,

	TEST_TYPE_STATS_FILL_EMPTY,

	TEST_TYPE_BPF_RES,

	TEST_TYPE_XDP_DROP_HALF,

	TEST_TYPE_MAX

};