Commit 2201124d authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'mptcp-userspace-path-manager-prerequisites' 

Mat Martineau says:

====================
mptcp: Userspace path manager prerequisites

This series builds upon the path manager mode selection changes merged
in 4994d4fa ("Merge branch 'mptcp-path-manager-mode-selection'") to
further modify the path manager code in preparation for adding the new
netlink commands to announce/remove advertised addresses and
create/destroy subflows of an MPTCP connection. The third and final
patch series for the userspace path manager will implement those
commands as discussed in
https://lore.kernel.org/netdev/23ff3b49-2563-1874-fa35-3af55d3088e7@linux.intel.com/#r

Patches 1, 5, and 7 remove some internal constraints on path managers
(in general) without changing in-kernel PM behavior.

Patch 2 adds a self test to validate MPTCP address advertisement ack
behavior.

Patches 3, 4, and 6 add new attributes to existing MPTCP netlink events
and track internal state for populating those attributes.
====================

Link: https://lore.kernel.org/r/20220502205237.129297-1-mathew.j.martineau@linux.intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 2b68abf9 304ab97f

include/uapi/linux/mptcp.h

+1 −0
Original line number Diff line number Diff line
@@ -188,6 +188,7 @@ enum mptcp_event_attr { 
	MPTCP_ATTR_IF_IDX,	/* s32 */

	MPTCP_ATTR_RESET_REASON,/* u32 */

	MPTCP_ATTR_RESET_FLAGS, /* u32 */

	MPTCP_ATTR_SERVER_SIDE,	/* u8 */



	__MPTCP_ATTR_AFTER_LAST

};

net/mptcp/options.c

+2 −2
Original line number Diff line number Diff line
@@ -931,7 +931,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, 
		if (TCP_SKB_CB(skb)->seq == subflow->ssn_offset + 1 &&

		    TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq &&

		    subflow->mp_join && (mp_opt->suboptions & OPTIONS_MPTCP_MPJ) &&

		    READ_ONCE(msk->pm.server_side))

		    !subflow->request_join)

			tcp_send_ack(ssk);

		goto fully_established;

	}
@@ -1133,7 +1133,7 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) 
		if ((mp_opt.suboptions & OPTION_MPTCP_ADD_ADDR) &&

		    add_addr_hmac_valid(msk, &mp_opt)) {

			if (!mp_opt.echo) {

				mptcp_pm_add_addr_received(msk, &mp_opt.addr);

				mptcp_pm_add_addr_received(sk, &mp_opt.addr);

				MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR);

			} else {

				mptcp_pm_add_addr_echoed(msk, &mp_opt.addr);

net/mptcp/pm.c

+17 −4
Original line number Diff line number Diff line
@@ -87,6 +87,9 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk) 
	unsigned int subflows_max;

	int ret = 0;



	if (mptcp_pm_is_userspace(msk))

		return mptcp_userspace_pm_active(msk);



	subflows_max = mptcp_pm_get_subflows_max(msk);



	pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows,
@@ -179,7 +182,8 @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk, 
	bool update_subflows;



	update_subflows = (ssk->sk_state == TCP_CLOSE) &&

			  (subflow->request_join || subflow->mp_join);

			  (subflow->request_join || subflow->mp_join) &&

			  mptcp_pm_is_kernel(msk);

	if (!READ_ONCE(pm->work_pending) && !update_subflows)

		return;
@@ -196,19 +200,28 @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk, 
	spin_unlock_bh(&pm->lock);

}



void mptcp_pm_add_addr_received(struct mptcp_sock *msk,

void mptcp_pm_add_addr_received(const struct sock *ssk,

				const struct mptcp_addr_info *addr)

{

	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);

	struct mptcp_sock *msk = mptcp_sk(subflow->conn);

	struct mptcp_pm_data *pm = &msk->pm;



	pr_debug("msk=%p remote_id=%d accept=%d", msk, addr->id,

		 READ_ONCE(pm->accept_addr));



	mptcp_event_addr_announced(msk, addr);

	mptcp_event_addr_announced(ssk, addr);



	spin_lock_bh(&pm->lock);



	if (!READ_ONCE(pm->accept_addr) || mptcp_pm_is_userspace(msk)) {

	if (mptcp_pm_is_userspace(msk)) {

		if (mptcp_userspace_pm_active(msk)) {

			mptcp_pm_announce_addr(msk, addr, true);

			mptcp_pm_add_addr_send_ack(msk);

		} else {

			__MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);

		}

	} else if (!READ_ONCE(pm->accept_addr)) {

		mptcp_pm_announce_addr(msk, addr, true);

		mptcp_pm_add_addr_send_ack(msk);

	} else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {

net/mptcp/pm_netlink.c

+31 −5
Original line number Diff line number Diff line
@@ -369,9 +369,17 @@ static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk, 


	lockdep_assert_held(&msk->pm.lock);



	if (mptcp_lookup_anno_list_by_saddr(msk, &entry->addr))

	add_entry = mptcp_lookup_anno_list_by_saddr(msk, &entry->addr);



	if (add_entry) {

		if (mptcp_pm_is_kernel(msk))

			return false;



		sk_reset_timer(sk, &add_entry->add_timer,

			       jiffies + mptcp_get_add_addr_timeout(net));

		return true;

	}



	add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);

	if (!add_entry)

		return false;
@@ -805,6 +813,9 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, 
		if (!removed)

			continue;



		if (!mptcp_pm_is_kernel(msk))

			continue;



		if (rm_type == MPTCP_MIB_RMADDR) {

			msk->pm.add_addr_accepted--;

			WRITE_ONCE(msk->pm.accept_addr, true);
@@ -1855,6 +1866,13 @@ static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gf 
				nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);

}



bool mptcp_userspace_pm_active(const struct mptcp_sock *msk)

{

	return genl_has_listeners(&mptcp_genl_family,

				  sock_net((const struct sock *)msk),

				  MPTCP_PM_EV_GRP_OFFSET);

}



static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)

{

	const struct inet_sock *issk = inet_sk(ssk);
@@ -1975,6 +1993,9 @@ 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)))

		return -EMSGSIZE;



	return mptcp_event_add_subflow(skb, ssk);

}
@@ -2009,10 +2030,12 @@ void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id) 
	kfree_skb(skb);

}



void mptcp_event_addr_announced(const struct mptcp_sock *msk,

void mptcp_event_addr_announced(const struct sock *ssk,

				const struct mptcp_addr_info *info)

{

	struct net *net = sock_net((const struct sock *)msk);

	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);

	struct mptcp_sock *msk = mptcp_sk(subflow->conn);

	struct net *net = sock_net(ssk);

	struct nlmsghdr *nlh;

	struct sk_buff *skb;
@@ -2034,7 +2057,10 @@ void mptcp_event_addr_announced(const struct mptcp_sock *msk, 
	if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))

		goto nla_put_failure;



	if (nla_put_be16(skb, MPTCP_ATTR_DPORT, info->port))

	if (nla_put_be16(skb, MPTCP_ATTR_DPORT,

			 info->port == 0 ?

			 inet_sk(ssk)->inet_dport :

			 info->port))

		goto nla_put_failure;



	switch (info->family) {

net/mptcp/protocol.c

+1 −4
Original line number Diff line number Diff line
@@ -3321,15 +3321,12 @@ bool mptcp_finish_join(struct sock *ssk) 
		return false;

	}



	if (!msk->pm.server_side)

	if (!list_empty(&subflow->node))

		goto out;



	if (!mptcp_pm_allow_new_subflow(msk))

		goto err_prohibited;



	if (WARN_ON_ONCE(!list_empty(&subflow->node)))

		goto err_prohibited;



	/* active connections are already on conn_list.

	 * If we can't acquire msk socket lock here, let the release callback

	 * handle it