[PATCH AUTOSEL 5.7 385/388] bpf: sockmap: Don't attach programs to UDP sockets

[Sasha Levin]

From: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>

[ Upstream commit f6fede8569689dd31e7b0ed15024b25e5ce2e2e5 ]

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 <lmb@xxxxxxxxxxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Acked-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20200611172520.327602-1-lmb@xxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 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 050bfac97cfb..7e858c1dd711 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -417,10 +417,7 @@ 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)
@@ -501,6 +498,11 @@ 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