[PATCH v2 bpf-next 07/11] bpf: mptcp: Don't support BPF_SOCK_OPS_RCVQ_CB.
From: Kuniyuki Iwashima <kuniyu@google.com>
Date: 2026-05-22 07:46:12
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
MPTCP has its own sock->ops->set_rcvlowat() / mptcp_set_rcvlowat(). We should not allow calling __tcp_set_rcvlowat() for MPTCP subflows. Let's disable BPF_SOCK_OPS_RCVQ_CB for MPTCP for now. If needed in the future, bpf_sock_ops_tcp_set_rcvlowat() could be extended to properly support MPTCP. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> --- net/core/filter.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/core/filter.c b/net/core/filter.c
index ff7fd415486a..5913b3be9f1d 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -5392,6 +5392,9 @@ static int bpf_sock_ops_check_rcvq_cb(struct sock *sk, int val) #endif if (not_tcp_prot) return -EBUSY; + + if (unlikely(sk_is_mptcp(sk))) + return -EOPNOTSUPP; } return 0;
--
2.54.0.746.g67dd491aae-goog