Commit 6bb63ccc authored by Mat Martineau's avatar Mat Martineau Committed by Jakub Kicinski
Browse files

mptcp: Add a per-namespace sysctl to set the default path manager type 



The new net.mptcp.pm_type sysctl determines which path manager will be
used by each newly-created MPTCP socket.

v2: Handle builds without CONFIG_SYSCTL
v3: Clarify logic for type-specific PM init (Geliang Tang and Paolo Abeni)

Acked-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 6961326e

Documentation/networking/mptcp-sysctl.rst

+18 −0
Original line number Diff line number Diff line
@@ -46,6 +46,24 @@ allow_join_initial_addr_port - BOOLEAN 


	Default: 1



pm_type - INTEGER



	Set the default path manager type to use for each new MPTCP

	socket. In-kernel path management will control subflow

	connections and address advertisements according to

	per-namespace values configured over the MPTCP netlink

	API. Userspace path management puts per-MPTCP-connection subflow

	connection decisions and address advertisements under control of

	a privileged userspace program, at the cost of more netlink

	traffic to propagate all of the related events and commands.



	This is a per-namespace sysctl.



	* 0 - In-kernel path manager

	* 1 - Userspace path manager



	Default: 0



stale_loss_cnt - INTEGER

	The number of MPTCP-level retransmission intervals with no traffic and

	pending outstanding data on a given subflow required to declare it stale.

net/mptcp/ctrl.c

+21 −0
Original line number Diff line number Diff line
@@ -16,6 +16,11 @@ 
#define MPTCP_SYSCTL_PATH "net/mptcp"



static int mptcp_pernet_id;



#ifdef CONFIG_SYSCTL

static int mptcp_pm_type_max = __MPTCP_PM_TYPE_MAX;

#endif



struct mptcp_pernet {

#ifdef CONFIG_SYSCTL

	struct ctl_table_header *ctl_table_hdr;
@@ -26,6 +31,7 @@ struct mptcp_pernet { 
	u8 mptcp_enabled;

	u8 checksum_enabled;

	u8 allow_join_initial_addr_port;

	u8 pm_type;

};



static struct mptcp_pernet *mptcp_get_pernet(const struct net *net)
@@ -58,6 +64,11 @@ unsigned int mptcp_stale_loss_cnt(const struct net *net) 
	return mptcp_get_pernet(net)->stale_loss_cnt;

}



int mptcp_get_pm_type(const struct net *net)

{

	return mptcp_get_pernet(net)->pm_type;

}



static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)

{

	pernet->mptcp_enabled = 1;
@@ -65,6 +76,7 @@ static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet) 
	pernet->checksum_enabled = 0;

	pernet->allow_join_initial_addr_port = 1;

	pernet->stale_loss_cnt = 4;

	pernet->pm_type = MPTCP_PM_TYPE_KERNEL;

}



#ifdef CONFIG_SYSCTL
@@ -108,6 +120,14 @@ static struct ctl_table mptcp_sysctl_table[] = { 
		.mode = 0644,

		.proc_handler = proc_douintvec_minmax,

	},

	{

		.procname = "pm_type",

		.maxlen = sizeof(u8),

		.mode = 0644,

		.proc_handler = proc_dou8vec_minmax,

		.extra1       = SYSCTL_ZERO,

		.extra2       = &mptcp_pm_type_max

	},

	{}

};
@@ -128,6 +148,7 @@ static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet) 
	table[2].data = &pernet->checksum_enabled;

	table[3].data = &pernet->allow_join_initial_addr_port;

	table[4].data = &pernet->stale_loss_cnt;

	table[5].data = &pernet->pm_type;



	hdr = register_net_sysctl(net, MPTCP_SYSCTL_PATH, table);

	if (!hdr)

net/mptcp/pm.c

+23 −11
Original line number Diff line number Diff line
@@ -415,7 +415,7 @@ void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk) 


void mptcp_pm_data_reset(struct mptcp_sock *msk)

{

	bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);

	u8 pm_type = mptcp_get_pm_type(sock_net((struct sock *)msk));

	struct mptcp_pm_data *pm = &msk->pm;



	pm->add_addr_signaled = 0;
@@ -424,17 +424,29 @@ void mptcp_pm_data_reset(struct mptcp_sock *msk) 
	pm->subflows = 0;

	pm->rm_list_tx.nr = 0;

	pm->rm_list_rx.nr = 0;

	WRITE_ONCE(pm->pm_type, MPTCP_PM_TYPE_KERNEL);

	WRITE_ONCE(pm->pm_type, pm_type);



	if (pm_type == MPTCP_PM_TYPE_KERNEL) {

		bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);



		/* pm->work_pending must be only be set to 'true' when

		 * pm->pm_type is set to MPTCP_PM_TYPE_KERNEL

		 */

		WRITE_ONCE(pm->work_pending,

		   (!!mptcp_pm_get_local_addr_max(msk) && subflows_allowed) ||

			   (!!mptcp_pm_get_local_addr_max(msk) &&

			    subflows_allowed) ||

			   !!mptcp_pm_get_add_addr_signal_max(msk));

	WRITE_ONCE(pm->addr_signal, 0);

		WRITE_ONCE(pm->accept_addr,

		   !!mptcp_pm_get_add_addr_accept_max(msk) && subflows_allowed);

			   !!mptcp_pm_get_add_addr_accept_max(msk) &&

			   subflows_allowed);

		WRITE_ONCE(pm->accept_subflow, subflows_allowed);

	} else {

		WRITE_ONCE(pm->work_pending, 0);

		WRITE_ONCE(pm->accept_addr, 0);

		WRITE_ONCE(pm->accept_subflow, 0);

	}



	WRITE_ONCE(pm->addr_signal, 0);

	WRITE_ONCE(pm->remote_deny_join_id0, false);

	pm->status = 0;

	bitmap_fill(msk->pm.id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);

net/mptcp/protocol.h

+1 −0
Original line number Diff line number Diff line
@@ -585,6 +585,7 @@ unsigned int mptcp_get_add_addr_timeout(const struct net *net); 
int mptcp_is_checksum_enabled(const struct net *net);

int mptcp_allow_join_id0(const struct net *net);

unsigned int mptcp_stale_loss_cnt(const struct net *net);

int mptcp_get_pm_type(const struct net *net);

void mptcp_subflow_fully_established(struct mptcp_subflow_context *subflow,

				     struct mptcp_options_received *mp_opt);

bool __mptcp_retransmit_pending_data(struct sock *sk);