[PATCH v5 bpf-next 08/10] bpf: mptcp: Don't support BPF_TCP_OPS_FLAG_RCVQ.
flat view
WARM2d
IN BPF-NEXT: 4 (3M)
From: Kuniyuki Iwashima <kuniyu@google.com>
Date: 2026-10-08 03:16:14
Also in:
bpf
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Revision v5 of 4 in this series; 2 review trailers; queued in bpf-next as d65dc83603eb on 2026-10-10.
Revisions (4)
- v2 [diff vs current]
- v3 [diff vs current]
- v4 [diff vs current]
- v5 current
The next patch exposes a new kfunc calling __tcp_set_rcvlowat() to bpf_tcp_ops. MPTCP has its own sock->ops->set_rcvlowat() / mptcp_set_rcvlowat(), so we should not allow calling __tcp_set_rcvlowat() on MPTCP subflows. Let's disable BPF_TCP_OPS_FLAG_RCVQ for MPTCP for now. If needed in the future, bpf_tcp_ops_set_rcvlowat() could be extended to properly support MPTCP. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Amery Hung <redacted> --- net/ipv4/bpf_tcp_ops.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/ipv4/bpf_tcp_ops.c b/net/ipv4/bpf_tcp_ops.c
index 9a6e1c47d7c0..8182037c4269 100644
--- a/net/ipv4/bpf_tcp_ops.c
+++ b/net/ipv4/bpf_tcp_ops.c@@ -347,6 +347,9 @@ __bpf_kfunc int bpf_tcp_ops_set_flags(struct tcp_sock *tp, u32 enable, u32 disab if ((enable & disable) || (enable | disable) & ~BPF_TCP_OPS_FLAG_ALL) return -EINVAL; + if (sk_is_mptcp((struct sock *)tp) && (enable & BPF_TCP_OPS_FLAG_RCVQ)) + return -EOPNOTSUPP; + old = READ_ONCE(tp->bpf_tcp_ops_flags); do {
--
2.56.0.360.g66cac248cb-goog