On Wed, Sep 20, 2023 at 11:19 AM -07, Kui-Feng Lee wrote:

On 9/20/23 03:20, Jakub Sitnicki wrote:

quoted

diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index cb11750b1df5..4292c2ed1828 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c

@@ -668,6 +668,8 @@ BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
  	sk = __sock_map_lookup_elem(map, key);
  	if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
  		return SK_DROP;
+	if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
+		return SK_DROP;
    	msg->flags = flags;
  	msg->sk_redir = sk;

@@ -1267,6 +1269,8 @@ BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
  	sk = __sock_hash_lookup_elem(map, key);
  	if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
  		return SK_DROP;
+	if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
+		return SK_DROP;
    	msg->flags = flags;
  	msg->sk_redir = sk;

Just be curious! Can it happen to other socket types?
I mean to redirect a msg from a sk of any type to one of another type.

Today sk_msg redirects are implemented only for tcp4 and tcp6.

Here's a full matrix of what redirects are supported [1].

[1] https://gist.github.com/jsitnicki/578fdd614d181bed2b02922b17972b4e