[PATCH bpf] bpf: sockmap: don't attach programs to UDP sockets

[Lorenz Bauer]

The stream parser infrastructure isn't set up to deal with UDP
sockets, so we mustn't try to attach programs to them.

I remember making this change at some point, but I must have lost
it while rebasing or something similar.

Fixes: 7b98cd42b049 ("bpf: sockmap: Add UDP support")
Signed-off-by: Lorenz Bauer <l...@cloudflare.com>
---
 net/core/sock_map.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 00a26cf2cfe9..35cea36f3892 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -424,10 +424,7 @@ static int sock_map_get_next_key(struct bpf_map *map, void 
*key, void *next)
        return 0;
 }
 
-static bool sock_map_redirect_allowed(const struct sock *sk)
-{
-       return sk->sk_state != TCP_LISTEN;
-}
+static bool sock_map_redirect_allowed(const struct sock *sk);
 
 static int sock_map_update_common(struct bpf_map *map, u32 idx,
                                  struct sock *sk, u64 flags)
@@ -508,6 +505,11 @@ static bool sk_is_udp(const struct sock *sk)
               sk->sk_protocol == IPPROTO_UDP;
 }
 
+static bool sock_map_redirect_allowed(const struct sock *sk)
+{
+       return sk_is_tcp(sk) && sk->sk_state != TCP_LISTEN;
+}
+
 static bool sock_map_sk_is_suitable(const struct sock *sk)
 {
        return sk_is_tcp(sk) || sk_is_udp(sk);
-- 
2.25.1