Currently, only TCP supports strparser, but sockmap doesn't intercept non-TCP to attach strparser. For example, with UDP, although the read/write handlers are replaced, strparser is not executed due to the lack of read_sock operation.
Furthermore, in udp_bpf_recvmsg(), it checks whether psock has data, and if not, it falls back to the native UDP read interface, making UDP + strparser appear to read correctly. According to it's commit history, the behavior is unexpected.
Moreover, since UDP lacks the concept of streams, we intercept it directly.
Signed-off-by: Jiayuan Chen mrpre@163.com --- net/core/sock_map.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/core/sock_map.c b/net/core/sock_map.c index f1b9b3958792..3b0f59d9b4db 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -303,7 +303,10 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk)
write_lock_bh(&sk->sk_callback_lock); if (stream_parser && stream_verdict && !psock->saved_data_ready) { - ret = sk_psock_init_strp(sk, psock); + if (sk_is_tcp(sk)) + ret = sk_psock_init_strp(sk, psock); + else + ret = -EOPNOTSUPP; if (ret) { write_unlock_bh(&sk->sk_callback_lock); sk_psock_put(sk, psock);