Commit f88191c7 authored by Matthieu Baerts (NGI0)'s avatar Matthieu Baerts (NGI0) Committed by Jakub Kicinski
Browse files

mptcp: pm: in-kernel: record fullmesh endp nb 



Instead of iterating over all endpoints, under RCU read lock, just to
check if one of them as the fullmesh flag, we can keep a counter of
fullmesh endpoint, similar to what is done with the other flags.

This counter is now checked, before iterating over all endpoints.

Similar to the other counters, this new one is also exposed. A userspace
app can then know when it is being used in a fullmesh mode, with
potentially (too) many subflows.

Reviewed-by: default avatarGeliang Tang <geliang@kernel.org>
Signed-off-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251101-net-next-mptcp-fm-endp-nb-bind-v1-1-b4166772d6bb@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b117befe

include/uapi/linux/mptcp.h

+2 −1
Original line number Diff line number Diff line
@@ -70,7 +70,8 @@ struct mptcp_info { 
	__u64	mptcpi_bytes_acked;

	__u8	mptcpi_subflows_total;

	__u8	mptcpi_endp_laminar_max;

	__u8	reserved[2];

	__u8	mptcpi_endp_fullmesh_max;

	__u8	reserved;

	__u32	mptcpi_last_data_sent;

	__u32	mptcpi_last_data_recv;

	__u32	mptcpi_last_ack_recv;

net/mptcp/pm_kernel.c

+35 −3
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ struct pm_nl_pernet { 
	u8			endp_signal_max;

	u8			endp_subflow_max;

	u8			endp_laminar_max;

	u8			endp_fullmesh_max;

	u8			limit_add_addr_accepted;

	u8			limit_extra_subflows;

	u8			next_id;
@@ -70,6 +71,14 @@ u8 mptcp_pm_get_endp_laminar_max(const struct mptcp_sock *msk) 
}

EXPORT_SYMBOL_GPL(mptcp_pm_get_endp_laminar_max);



u8 mptcp_pm_get_endp_fullmesh_max(const struct mptcp_sock *msk)

{

	struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);



	return READ_ONCE(pernet->endp_fullmesh_max);

}

EXPORT_SYMBOL_GPL(mptcp_pm_get_endp_fullmesh_max);



u8 mptcp_pm_get_limit_add_addr_accepted(const struct mptcp_sock *msk)

{

	struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
@@ -603,9 +612,12 @@ fill_local_addresses_vec(struct mptcp_sock *msk, struct mptcp_addr_info *remote, 
	int i;



	/* If there is at least one MPTCP endpoint with a fullmesh flag */

	i = fill_local_addresses_vec_fullmesh(msk, remote, locals, c_flag_case);

	if (mptcp_pm_get_endp_fullmesh_max(msk)) {

		i = fill_local_addresses_vec_fullmesh(msk, remote, locals,

						      c_flag_case);

		if (i)

			return i;

	}



	/* If there is at least one MPTCP endpoint with a laminar flag */

	if (mptcp_pm_get_endp_laminar_max(msk))
@@ -790,6 +802,10 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, 
		addr_max = pernet->endp_laminar_max;

		WRITE_ONCE(pernet->endp_laminar_max, addr_max + 1);

	}

	if (entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) {

		addr_max = pernet->endp_fullmesh_max;

		WRITE_ONCE(pernet->endp_fullmesh_max, addr_max + 1);

	}



	pernet->endpoints++;

	if (!entry->addr.port)
@@ -1187,6 +1203,10 @@ int mptcp_pm_nl_del_addr_doit(struct sk_buff *skb, struct genl_info *info) 
		addr_max = pernet->endp_laminar_max;

		WRITE_ONCE(pernet->endp_laminar_max, addr_max - 1);

	}

	if (entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) {

		addr_max = pernet->endp_fullmesh_max;

		WRITE_ONCE(pernet->endp_fullmesh_max, addr_max - 1);

	}



	pernet->endpoints--;

	list_del_rcu(&entry->list);
@@ -1502,6 +1522,18 @@ int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local, 
	changed = (local->flags ^ entry->flags) & mask;

	entry->flags = (entry->flags & ~mask) | (local->flags & mask);

	*local = *entry;



	if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH) {

		u8 addr_max = pernet->endp_fullmesh_max;



		if (entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH)

			addr_max++;

		else

			addr_max--;



		WRITE_ONCE(pernet->endp_fullmesh_max, addr_max);

	}



	spin_unlock_bh(&pernet->lock);



	mptcp_pm_nl_set_flags_all(net, local, changed);

net/mptcp/protocol.h

+1 −0
Original line number Diff line number Diff line
@@ -1183,6 +1183,7 @@ void __mptcp_pm_kernel_worker(struct mptcp_sock *msk); 
u8 mptcp_pm_get_endp_signal_max(const struct mptcp_sock *msk);

u8 mptcp_pm_get_endp_subflow_max(const struct mptcp_sock *msk);

u8 mptcp_pm_get_endp_laminar_max(const struct mptcp_sock *msk);

u8 mptcp_pm_get_endp_fullmesh_max(const struct mptcp_sock *msk);

u8 mptcp_pm_get_limit_add_addr_accepted(const struct mptcp_sock *msk);

u8 mptcp_pm_get_limit_extra_subflows(const struct mptcp_sock *msk);

net/mptcp/sockopt.c

+2 −0
Original line number Diff line number Diff line
@@ -982,6 +982,8 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) 
			mptcp_pm_get_endp_subflow_max(msk);

		info->mptcpi_endp_laminar_max =

			mptcp_pm_get_endp_laminar_max(msk);

		info->mptcpi_endp_fullmesh_max =

			mptcp_pm_get_endp_fullmesh_max(msk);

	}



	if (__mptcp_check_fallback(msk))