On Tue, Jan 21, 2025 at 01:07 PM +08, Jiayuan Chen wrote:
> 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
Nit: typo, "its"
> history, the behavior is unexpected.
>
> Moreover, since UDP lacks the concept of streams, we intercept it
> directly.
>
> Signed-off-by: Jiayuan Chen <mrpre@xxxxxxx>
> ---
> 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);
Reviewed-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
