Commit c9809f03 authored Sep 19, 2025 by Matthieu Baerts (NGI0) Committed by Jakub Kicinski Sep 22, 2025

mptcp: pm: netlink: only add server-side attr when true



This attribute is a boolean. No need to add it to set it to 'false'.

Indeed, the default value when this attribute is not set is naturally
'false'. A few bytes can then be saved by not adding this attribute if
the connection is not on the server side.

This prepares the future deprecation of its attribute, in favour of a
new flag.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250919-net-next-mptcp-server-side-flag-v1-1-a97a5d561a8b@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 35626012

Documentation/netlink/specs/mptcp_pm.yaml

+2 −2

Original line number	Diff line number	Diff line
		@@ -28,13 +28,13 @@ definitions:
		traffic-patterns it can take a long time until the
		MPTCP_EVENT_ESTABLISHED is sent.
		Attributes: token, family, saddr4 \| saddr6, daddr4 \| daddr6, sport,
		dport, server-side, [flags].
		dport, [server-side], [flags].
		-
		name: established
		doc: >-
		A MPTCP connection is established (can start new subflows).
		Attributes: token, family, saddr4 \| saddr6, daddr4 \| daddr6, sport,
		dport, server-side, [flags].
		dport, [server-side], [flags].
		-
		name: closed
		doc: >-

include/uapi/linux/mptcp_pm.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -16,10 +16,10 @@
		* good time to allocate memory and send ADD_ADDR if needed. Depending on the
		* traffic-patterns it can take a long time until the MPTCP_EVENT_ESTABLISHED
		* is sent. Attributes: token, family, saddr4 \| saddr6, daddr4 \| daddr6,
		* sport, dport, server-side, [flags].
		* sport, dport, [server-side], [flags].
		* @MPTCP_EVENT_ESTABLISHED: A MPTCP connection is established (can start new
		* subflows). Attributes: token, family, saddr4 \| saddr6, daddr4 \| daddr6,
		* sport, dport, server-side, [flags].
		* sport, dport, [server-side], [flags].
		* @MPTCP_EVENT_CLOSED: A MPTCP connection has stopped. Attribute: token.
		* @MPTCP_EVENT_ANNOUNCED: A new address has been announced by the peer.
		* Attributes: token, rem_id, family, daddr4 \| daddr6 [, dport].

net/mptcp/pm_netlink.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -413,7 +413,9 @@ static int mptcp_event_created(struct sk_buff *skb,
		if (err)
		return err;

		if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, READ_ONCE(msk->pm.server_side)))
		/* only set when it is the server side */
		if (READ_ONCE(msk->pm.server_side) &&
		nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, 1))
		return -EMSGSIZE;

		if (READ_ONCE(msk->pm.remote_deny_join_id0))

tools/testing/selftests/net/mptcp/userspace_pm.sh

+1 −1

Original line number	Diff line number	Diff line
		@@ -241,7 +241,7 @@ make_connection()

		print_test "Established IP${is_v6} MPTCP Connection ns2 => ns1"
		if [ "${client_token}" != "" ] && [ "${server_token}" != "" ] &&
		[ "${client_serverside}" = 0 ] && [ "${server_serverside}" = 1 ] &&
		[ "${client_serverside:-0}" = 0 ] && [ "${server_serverside:-0}" = 1 ] &&
		[ "${client_nojoin:-0}" = 0 ] && [ "${server_nojoin:-0}" = 1 ]
		then
		test_pass