On Sat, Aug 8, 2020 at 11:46 AM Jakub Sitnicki <jakub@xxxxxxxxxxxxxx> wrote: > > 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. Up to you, but I'm not sure zeroing out the whole v6 portion is the best way forward. IMO, it's a bit confusing when reading the code. It will work, but only because v4 and v6 address portions don't really overlap :-/ I was thinking about adding new, on the stack sin6, fully initializing it and then doing memcpy into ss. But I decided that adding memset is probably good enough :-)
