On Sat, Aug 08, 2020 at 12:38 AM CEST, Stanislav Fomichev wrote:
> I'm getting some garbage in bytes 8 and 9 when doing conversion
> from sockaddr_in to sockaddr_in6 (leftover from AF_INET?).
> Let's explicitly clear the higher bytes.
>
> Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
> ---
> tools/testing/selftests/bpf/prog_tests/sk_lookup.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c
> index c571584c00f5..9ff0412e1fd3 100644
> --- a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c
> +++ b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c
> @@ -309,6 +309,7 @@ static void v4_to_v6(struct sockaddr_storage *ss)
> v6->sin6_addr.s6_addr[10] = 0xff;
> v6->sin6_addr.s6_addr[11] = 0xff;
> memcpy(&v6->sin6_addr.s6_addr[12], &v4.sin_addr.s_addr, 4);
> + memset(&v6->sin6_addr.s6_addr[0], 0, 10);
> }
>
> static int udp_recv_send(int server_fd)
That was badly written. Sorry about that. And thanks for the fix.
I'd even zero out the whole thing:
memset(v6, 0, sizeof(*v6));
... because right now IPv4 address is left as sin6_flowinfo. I can
follow up with that change, unless you'd like to roll a v2.
Fixes: 0ab5539f8584 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point")
Reviewed-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
