From baba7cfa1b7e48e8cbf449c9f3e8eca3e1018564 Mon Sep 17 00:00:00 2001
From: Jiayuan Chen <mrpre@163.com>
Date: Wed, 22 Jan 2025 18:09:15 +0800
Subject: [PATCH] bpf: Disable non stream socket for strparser
[ Upstream commit 5459cce6bf49e72ee29be21865869c2ac42419f5 ]
Currently, only TCP supports strparser, but sockmap doesn't intercept
non-TCP connections to attach strparser. For example, with UDP, although
the read/write handlers are replaced, strparser is not executed due to
the lack of a read_sock operation.
Furthermore, in udp_bpf_recvmsg(), it checks whether the psock has data,
and if not, it falls back to the native UDP read interface, making
UDP + strparser appear to read correctly. According to its commit history,
this behavior is unexpected.
Moreover, since UDP lacks the concept of streams, we intercept it directly.
Fixes: 1fa1fe8ff161 ("bpf, sockmap: Test shutdown() correctly exits epoll and recv()=0")
Signed-off-by: Jiayuan Chen <mrpre@163.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://patch.msgid.link/20250122100917.49845-4-mrpre@163.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 2f1be9baad057..82a14f131d00c 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);
--
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