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mptcp: blackhole: avoid checking the state twice

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A small cleanup, reordering the conditions to avoid checking things
twice.

The code here is called in case of timeout on a TCP connection, before
triggering a retransmission. But it only acts on SYN + MPC packets.

So the conditions can be re-order to exit early in case of non-MPTCP
SYN + MPC. This also reduce the indentation levels.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250221-net-next-mptcp-pm-misc-cleanup-3-v1-10-2b70ab1cee79@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Matthieu Baerts (NGI0)
2025-02-24 18:23:44 -08:00
committed by Jakub Kicinski
parent b68b106b0f
commit 8275ac799e
1 changed files with 18 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files
net/mptcp/ctrl.c
+18 -14
View File
@@ -401,26 +401,30 @@ void mptcp_active_enable(struct sock *sk)
void mptcp_active_detect_blackhole(struct sock *ssk, bool expired)
{
struct mptcp_subflow_context *subflow;
u8 timeouts, to_max;
struct net *net;
if (!sk_is_mptcp(ssk))
/* Only check MPTCP SYN ... */
if (likely(!sk_is_mptcp(ssk) || ssk->sk_state != TCP_SYN_SENT))
return;
subflow = mptcp_subflow_ctx(ssk);
if (subflow->request_mptcp && ssk->sk_state == TCP_SYN_SENT) {
struct net *net = sock_net(ssk);
u8 timeouts, to_max;
timeouts = inet_csk(ssk)->icsk_retransmits;
to_max = mptcp_get_pernet(net)->syn_retrans_before_tcp_fallback;
if (timeouts == to_max || (timeouts < to_max && expired)) {
MPTCP_INC_STATS(net, MPTCP_MIB_MPCAPABLEACTIVEDROP);
subflow->mpc_drop = 1;
mptcp_subflow_early_fallback(mptcp_sk(subflow->conn), subflow);
}
} else if (ssk->sk_state == TCP_SYN_SENT) {
/* ... + MP_CAPABLE */
if (!subflow->request_mptcp) {
/* Mark as blackhole iif the 1st non-MPTCP SYN is accepted */
subflow->mpc_drop = 0;
return;
}
net = sock_net(ssk);
timeouts = inet_csk(ssk)->icsk_retransmits;
to_max = mptcp_get_pernet(net)->syn_retrans_before_tcp_fallback;
if (timeouts == to_max || (timeouts < to_max && expired)) {
MPTCP_INC_STATS(net, MPTCP_MIB_MPCAPABLEACTIVEDROP);
subflow->mpc_drop = 1;
mptcp_subflow_early_fallback(mptcp_sk(subflow->conn), subflow);
}
}