Re: [PATCH bpf v8 3/5] bpf: disable non stream socket for strparser
From: Jakub Sitnicki <jakub@cloudflare.com>
Date: 2025-01-21 14:23:04
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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"
quoted hunk
history, the behavior is unexpected. Moreover, since UDP lacks the concept of streams, we intercept it directly. Signed-off-by: Jiayuan Chen <redacted> --- 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@cloudflare.com>