Re: [PATCH v3 bpf-next 7/8] selftests/bpf: add test for bpf_xdp_query xdp-features support

[sdf@google.com]

On 01/26, Lorenzo Bianconi wrote:
> Introduce a self-test to verify libbpf bpf_xdp_query capability to dump
> the xdp-features supported by the device (lo and veth in this case).

> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>

Acked-by: Stanislav Fomichev <sdf@google.com>

> ---
>   .../bpf/prog_tests/xdp_do_redirect.c          | 27 ++++++++++++++++++-
>   .../selftests/bpf/prog_tests/xdp_info.c       |  8 ++++++
>   2 files changed, 34 insertions(+), 1 deletion(-)

> diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c  
> b/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c
> index a50971c6cf4a..e15fb3f0306c 100644
> --- a/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c
> +++ b/tools/testing/selftests/bpf/prog_tests/xdp_do_redirect.c
> @@ -4,10 +4,12 @@
>   #include <net/if.h>
>   #include <linux/if_ether.h>
>   #include <linux/if_packet.h>
> +#include <linux/if_link.h>
>   #include <linux/ipv6.h>
>   #include <linux/in6.h>
>   #include <linux/udp.h>
>   #include <bpf/bpf_endian.h>
> +#include <uapi/linux/netdev.h>
>   #include "test_xdp_do_redirect.skel.h"

>   #define SYS(fmt, ...)						\
> @@ -92,7 +94,7 @@ void test_xdp_do_redirect(void)
>   	struct test_xdp_do_redirect *skel = NULL;
>   	struct nstoken *nstoken = NULL;
>   	struct bpf_link *link;
> -
> +	LIBBPF_OPTS(bpf_xdp_query_opts, query_opts);
>   	struct xdp_md ctx_in = { .data = sizeof(__u32),
>   				 .data_end = sizeof(data) };
>   	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
> @@ -153,6 +155,29 @@ void test_xdp_do_redirect(void)
>   	    !ASSERT_NEQ(ifindex_dst, 0, "ifindex_dst"))
>   		goto out;

> +	/* Check xdp features supported by veth driver */
> +	err = bpf_xdp_query(ifindex_src, XDP_FLAGS_DRV_MODE, &query_opts);
> +	if (!ASSERT_OK(err, "veth_src bpf_xdp_query"))
> +		goto out;
> +
> +	if (!ASSERT_EQ(query_opts.fflags,
> +		       NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT |
> +		       NETDEV_XDP_ACT_NDO_XMIT | NETDEV_XDP_ACT_RX_SG |
> +		       NETDEV_XDP_ACT_NDO_XMIT_SG,
> +		       "veth_src query_opts.fflags"))
> +		goto out;
> +
> +	err = bpf_xdp_query(ifindex_dst, XDP_FLAGS_DRV_MODE, &query_opts);
> +	if (!ASSERT_OK(err, "veth_dst bpf_xdp_query"))
> +		goto out;
> +
> +	if (!ASSERT_EQ(query_opts.fflags,
> +		       NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT |
> +		       NETDEV_XDP_ACT_NDO_XMIT | NETDEV_XDP_ACT_RX_SG |
> +		       NETDEV_XDP_ACT_NDO_XMIT_SG,
> +		       "veth_dst query_opts.fflags"))
> +		goto out;
> +
>   	memcpy(skel->rodata->expect_dst, &pkt_udp.eth.h_dest, ETH_ALEN);
>   	skel->rodata->ifindex_out = ifindex_src; /* redirect back to the same  
> iface */
>   	skel->rodata->ifindex_in = ifindex_src;
> diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_info.c  
> b/tools/testing/selftests/bpf/prog_tests/xdp_info.c
> index cd3aa340e65e..8397468a9e74 100644
> --- a/tools/testing/selftests/bpf/prog_tests/xdp_info.c
> +++ b/tools/testing/selftests/bpf/prog_tests/xdp_info.c
> @@ -8,6 +8,7 @@ void serial_test_xdp_info(void)
>   {
>   	__u32 len = sizeof(struct bpf_prog_info), duration = 0, prog_id;
>   	const char *file = "./xdp_dummy.bpf.o";
> +	LIBBPF_OPTS(bpf_xdp_query_opts, opts);
>   	struct bpf_prog_info info = {};
>   	struct bpf_object *obj;
>   	int err, prog_fd;
> @@ -61,6 +62,13 @@ void serial_test_xdp_info(void)
>   	if (CHECK(prog_id, "prog_id_drv", "unexpected prog_id=%u\n", prog_id))
>   		goto out;

> +	/* Check xdp features supported by lo device */
> +	opts.fflags = ~0;
> +	err = bpf_xdp_query(IFINDEX_LO, XDP_FLAGS_DRV_MODE, &opts);
> +	if (!ASSERT_OK(err, "bpf_xdp_query"))
> +		goto out;
> +
> +	ASSERT_EQ(opts.fflags, 0, "opts.fflags");
>   out:
>   	bpf_xdp_detach(IFINDEX_LO, 0, NULL);
>   out_close:
> --
> 2.39.1