Merge branch 'mptcp-pathmanager-api'

Mat Martineau says:

====================
mptcp: Userspace path manager API

Userspace path managers (PMs) make use of generic netlink MPTCP events
and commands to control addition and removal of MPTCP subflows on an
existing MPTCP connection. The path manager events have already been
upstream for a while, and this patch series adds four netlink commands
for userspace:

* MPTCP_PM_CMD_ANNOUNCE: advertise an address that's available for
additional subflow connections.

* MPTCP_PM_CMD_REMOVE: revoke an advertisement

* MPTCP_PM_CMD_SUBFLOW_CREATE: initiate a new subflow on an existing MPTCP
connection

* MPTCP_PM_CMD_SUBFLOW_DESTROY: close a subflow on an existing MPTCP
connection

Userspace path managers, such as mptcpd, can be more easily customized
for different devices. The in-kernel path manager remains available to
handle server use cases.

Patches 1-3 update common path manager code (used by both in-kernel and
userspace PMs)

Patches 4, 6, and 8 implement the new generic netlink commands.

Patches 5, 7, and 9-13 add self test support and test cases for the new
path manager commands.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 575 insertions, 54 deletions

diff --git a/net/mptcp/Makefile b/net/mptcp/Makefile
index e54daceac58b..cb7f53f6ab22 100644
--- a/net/mptcp/Makefile
+++ b/net/mptcp/Makefile
@@ -2,7 +2,7 @@
 obj-$(CONFIG_MPTCP) += mptcp.o
 
 mptcp-y := protocol.o subflow.o options.o token.o crypto.o ctrl.o pm.o diag.o \
-	   mib.o pm_netlink.o sockopt.o
+	   mib.o pm_netlink.o sockopt.o pm_userspace.o
 
 obj-$(CONFIG_SYN_COOKIES) += syncookies.o
 obj-$(CONFIG_INET_MPTCP_DIAG) += mptcp_diag.o
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 5d6832c4d9f2..cdc2d79071f8 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -469,6 +469,7 @@ void mptcp_pm_data_init(struct mptcp_sock *msk)
 {
 	spin_lock_init(&msk->pm.lock);
 	INIT_LIST_HEAD(&msk->pm.anno_list);
+	INIT_LIST_HEAD(&msk->pm.userspace_pm_local_addr_list);
 	mptcp_pm_data_reset(msk);
 }
 
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 98b205c2c101..e099f2a12504 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -22,14 +22,6 @@ static struct genl_family mptcp_genl_family;
 
 static int pm_nl_pernet_id;
 
-struct mptcp_pm_addr_entry {
-	struct list_head	list;
-	struct mptcp_addr_info	addr;
-	u8			flags;
-	int			ifindex;
-	struct socket		*lsk;
-};
-
 struct mptcp_pm_add_entry {
 	struct list_head	list;
 	struct mptcp_addr_info	addr;
@@ -66,8 +58,8 @@ pm_nl_get_pernet_from_msk(const struct mptcp_sock *msk)
 	return pm_nl_get_pernet(sock_net((struct sock *)msk));
 }
 
-static bool addresses_equal(const struct mptcp_addr_info *a,
-			    const struct mptcp_addr_info *b, bool use_port)
+bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
+			   const struct mptcp_addr_info *b, bool use_port)
 {
 	bool addr_equals = false;
 
@@ -131,7 +123,7 @@ static bool lookup_subflow_by_saddr(const struct list_head *list,
 		skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 
 		local_address(skc, &cur);
-		if (addresses_equal(&cur, saddr, saddr->port))
+		if (mptcp_addresses_equal(&cur, saddr, saddr->port))
 			return true;
 	}
 
@@ -149,7 +141,7 @@ static bool lookup_subflow_by_daddr(const struct list_head *list,
 		skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 
 		remote_address(skc, &cur);
-		if (addresses_equal(&cur, daddr, daddr->port))
+		if (mptcp_addresses_equal(&cur, daddr, daddr->port))
 			return true;
 	}
 
@@ -269,7 +261,7 @@ mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 	lockdep_assert_held(&msk->pm.lock);
 
 	list_for_each_entry(entry, &msk->pm.anno_list, list) {
-		if (addresses_equal(&entry->addr, addr, true))
+		if (mptcp_addresses_equal(&entry->addr, addr, true))
 			return entry;
 	}
 
@@ -286,7 +278,7 @@ bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
 
 	spin_lock_bh(&msk->pm.lock);
 	list_for_each_entry(entry, &msk->pm.anno_list, list) {
-		if (addresses_equal(&entry->addr, &saddr, true)) {
+		if (mptcp_addresses_equal(&entry->addr, &saddr, true)) {
 			ret = true;
 			goto out;
 		}
@@ -360,8 +352,8 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 	return entry;
 }
 
-static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
-				     const struct mptcp_pm_addr_entry *entry)
+bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
+			      const struct mptcp_pm_addr_entry *entry)
 {
 	struct mptcp_pm_add_entry *add_entry = NULL;
 	struct sock *sk = (struct sock *)msk;
@@ -421,7 +413,7 @@ static bool lookup_address_in_vec(const struct mptcp_addr_info *addrs, unsigned
 	int i;
 
 	for (i = 0; i < nr; i++) {
-		if (addresses_equal(&addrs[i], addr, addr->port))
+		if (mptcp_addresses_equal(&addrs[i], addr, addr->port))
 			return true;
 	}
 
@@ -457,7 +449,7 @@ static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk, bool fullm
 		mptcp_for_each_subflow(msk, subflow) {
 			ssk = mptcp_subflow_tcp_sock(subflow);
 			remote_address((struct sock_common *)ssk, &addrs[i]);
-			if (deny_id0 && addresses_equal(&addrs[i], &remote, false))
+			if (deny_id0 && mptcp_addresses_equal(&addrs[i], &remote, false))
 				continue;
 
 			if (!lookup_address_in_vec(addrs, i, &addrs[i]) &&
@@ -490,7 +482,7 @@ __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info,
 	struct mptcp_pm_addr_entry *entry;
 
 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
-		if ((!lookup_by_id && addresses_equal(&entry->addr, info, true)) ||
+		if ((!lookup_by_id && mptcp_addresses_equal(&entry->addr, info, true)) ||
 		    (lookup_by_id && entry->addr.id == info->id))
 			return entry;
 	}
@@ -505,7 +497,7 @@ lookup_id_by_addr(const struct pm_nl_pernet *pernet, const struct mptcp_addr_inf
 
 	rcu_read_lock();
 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
-		if (addresses_equal(&entry->addr, addr, entry->addr.port)) {
+		if (mptcp_addresses_equal(&entry->addr, addr, entry->addr.port)) {
 			ret = entry->addr.id;
 			break;
 		}
@@ -739,7 +731,7 @@ static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 		struct mptcp_addr_info local;
 
 		local_address((struct sock_common *)ssk, &local);
-		if (!addresses_equal(&local, addr, addr->port))
+		if (!mptcp_addresses_equal(&local, addr, addr->port))
 			continue;
 
 		if (subflow->backup != bkup)
@@ -909,9 +901,9 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
 	 * singled addresses
 	 */
 	list_for_each_entry(cur, &pernet->local_addr_list, list) {
-		if (addresses_equal(&cur->addr, &entry->addr,
-				    address_use_port(entry) &&
-				    address_use_port(cur))) {
+		if (mptcp_addresses_equal(&cur->addr, &entry->addr,
+					  address_use_port(entry) &&
+					  address_use_port(cur))) {
 			/* allow replacing the exiting endpoint only if such
 			 * endpoint is an implicit one and the user-space
 			 * did not provide an endpoint id
@@ -1038,14 +1030,17 @@ int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 	 */
 	local_address((struct sock_common *)msk, &msk_local);
 	local_address((struct sock_common *)skc, &skc_local);
-	if (addresses_equal(&msk_local, &skc_local, false))
+	if (mptcp_addresses_equal(&msk_local, &skc_local, false))
 		return 0;
 
+	if (mptcp_pm_is_userspace(msk))
+		return mptcp_userspace_pm_get_local_id(msk, &skc_local);
+
 	pernet = pm_nl_get_pernet_from_msk(msk);
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
-		if (addresses_equal(&entry->addr, &skc_local, entry->addr.port)) {
+		if (mptcp_addresses_equal(&entry->addr, &skc_local, entry->addr.port)) {
 			ret = entry->addr.id;
 			break;
 		}
@@ -1099,6 +1094,10 @@ static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
 					NLA_POLICY_NESTED(mptcp_pm_addr_policy),
 	[MPTCP_PM_ATTR_RCV_ADD_ADDRS]	= { .type	= NLA_U32,	},
 	[MPTCP_PM_ATTR_SUBFLOWS]	= { .type	= NLA_U32,	},
+	[MPTCP_PM_ATTR_TOKEN]		= { .type	= NLA_U32,	},
+	[MPTCP_PM_ATTR_LOC_ID]		= { .type	= NLA_U8,	},
+	[MPTCP_PM_ATTR_ADDR_REMOTE]	=
+					NLA_POLICY_NESTED(mptcp_pm_addr_policy),
 };
 
 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
@@ -1147,11 +1146,12 @@ static int mptcp_pm_family_to_addr(int family)
 	return MPTCP_PM_ADDR_ATTR_ADDR4;
 }
 
-static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
-			       bool require_family,
-			       struct mptcp_pm_addr_entry *entry)
+static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
+				       const struct nlattr *attr,
+				       struct genl_info *info,
+				       struct mptcp_addr_info *addr,
+				       bool require_family)
 {
-	struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
 	int err, addr_addr;
 
 	if (!attr) {
@@ -1165,27 +1165,29 @@ static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
 	if (err)
 		return err;
 
-	memset(entry, 0, sizeof(*entry));
+	if (tb[MPTCP_PM_ADDR_ATTR_ID])
+		addr->id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
+
 	if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
 		if (!require_family)
-			goto skip_family;
+			return err;
 
 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
 				    "missing family");
 		return -EINVAL;
 	}
 
-	entry->addr.family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
-	if (entry->addr.family != AF_INET
+	addr->family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
+	if (addr->family != AF_INET
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
-	    && entry->addr.family != AF_INET6
+	    && addr->family != AF_INET6
 #endif
 	    ) {
 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
 				    "unknown address family");
 		return -EINVAL;
 	}
-	addr_addr = mptcp_pm_family_to_addr(entry->addr.family);
+	addr_addr = mptcp_pm_family_to_addr(addr->family);
 	if (!tb[addr_addr]) {
 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
 				    "missing address data");
@@ -1193,22 +1195,47 @@ static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
 	}
 
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
-	if (entry->addr.family == AF_INET6)
-		entry->addr.addr6 = nla_get_in6_addr(tb[addr_addr]);
+	if (addr->family == AF_INET6)
+		addr->addr6 = nla_get_in6_addr(tb[addr_addr]);
 	else
 #endif
-		entry->addr.addr.s_addr = nla_get_in_addr(tb[addr_addr]);
+		addr->addr.s_addr = nla_get_in_addr(tb[addr_addr]);
+
+	if (tb[MPTCP_PM_ADDR_ATTR_PORT])
+		addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
+
+	return err;
+}
+
+int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
+			struct mptcp_addr_info *addr)
+{
+	struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
+
+	memset(addr, 0, sizeof(*addr));
+
+	return mptcp_pm_parse_pm_addr_attr(tb, attr, info, addr, true);
+}
+
+int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
+			 bool require_family,
+			 struct mptcp_pm_addr_entry *entry)
+{
+	struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
+	int err;
+
+	memset(entry, 0, sizeof(*entry));
+
+	err = mptcp_pm_parse_pm_addr_attr(tb, attr, info, &entry->addr, require_family);
+	if (err)
+		return err;
 
-skip_family:
 	if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
 		u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
 
 		entry->ifindex = val;
 	}
 
-	if (tb[MPTCP_PM_ADDR_ATTR_ID])
-		entry->addr.id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
-
 	if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
 		entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
 
@@ -1256,7 +1283,7 @@ static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
 	struct mptcp_pm_addr_entry addr, *entry;
 	int ret;
 
-	ret = mptcp_pm_parse_addr(attr, info, true, &addr);
+	ret = mptcp_pm_parse_entry(attr, info, true, &addr);
 	if (ret < 0)
 		return ret;
 
@@ -1305,15 +1332,23 @@ static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
 	return 0;
 }
 
-int mptcp_pm_get_flags_and_ifindex_by_id(struct net *net, unsigned int id,
+int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
 					 u8 *flags, int *ifindex)
 {
 	struct mptcp_pm_addr_entry *entry;
+	struct sock *sk = (struct sock *)msk;
+	struct net *net = sock_net(sk);
 
 	*flags = 0;
 	*ifindex = 0;
 
 	if (id) {
+		if (mptcp_pm_is_userspace(msk))
+			return mptcp_userspace_pm_get_flags_and_ifindex_by_id(msk,
+									      id,
+									      flags,
+									      ifindex);
+
 		rcu_read_lock();
 		entry = __lookup_addr_by_id(pm_nl_get_pernet(net), id);
 		if (entry) {
@@ -1416,7 +1451,7 @@ static int mptcp_nl_remove_id_zero_address(struct net *net,
 			goto next;
 
 		local_address((struct sock_common *)msk, &msk_local);
-		if (!addresses_equal(&msk_local, addr, addr->port))
+		if (!mptcp_addresses_equal(&msk_local, addr, addr->port))
 			goto next;
 
 		lock_sock(sk);
@@ -1442,7 +1477,7 @@ static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
 	unsigned int addr_max;
 	int ret;
 
-	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
+	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
 	if (ret < 0)
 		return ret;
 
@@ -1482,8 +1517,8 @@ static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-static void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
-					       struct list_head *rm_list)
+void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
+					struct list_head *rm_list)
 {
 	struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 };
 	struct mptcp_pm_addr_entry *entry;
@@ -1616,7 +1651,7 @@ static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
 	void *reply;
 	int ret;
 
-	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
+	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
 	if (ret < 0)
 		return ret;
 
@@ -1827,7 +1862,7 @@ static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
 	u8 bkup = 0, lookup_by_id = 0;
 	int ret;
 
-	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
+	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
 	if (ret < 0)
 		return ret;
 
@@ -2177,6 +2212,26 @@ static const struct genl_small_ops mptcp_pm_ops[] = {
 		.doit   = mptcp_nl_cmd_set_flags,
 		.flags  = GENL_ADMIN_PERM,
 	},
+	{
+		.cmd    = MPTCP_PM_CMD_ANNOUNCE,
+		.doit   = mptcp_nl_cmd_announce,
+		.flags  = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd    = MPTCP_PM_CMD_REMOVE,
+		.doit   = mptcp_nl_cmd_remove,
+		.flags  = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd    = MPTCP_PM_CMD_SUBFLOW_CREATE,
+		.doit   = mptcp_nl_cmd_sf_create,
+		.flags  = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd    = MPTCP_PM_CMD_SUBFLOW_DESTROY,
+		.doit   = mptcp_nl_cmd_sf_destroy,
+		.flags  = GENL_ADMIN_PERM,
+	},
 };
 
 static struct genl_family mptcp_genl_family __ro_after_init = {
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
new file mode 100644
index 000000000000..f56378e4f597
--- /dev/null
+++ b/net/mptcp/pm_userspace.c
@@ -0,0 +1,429 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Multipath TCP
+ *
+ * Copyright (c) 2022, Intel Corporation.
+ */
+
+#include "protocol.h"
+
+void mptcp_free_local_addr_list(struct mptcp_sock *msk)
+{
+	struct mptcp_pm_addr_entry *entry, *tmp;
+	struct sock *sk = (struct sock *)msk;
+	LIST_HEAD(free_list);
+
+	if (!mptcp_pm_is_userspace(msk))
+		return;
+
+	spin_lock_bh(&msk->pm.lock);
+	list_splice_init(&msk->pm.userspace_pm_local_addr_list, &free_list);
+	spin_unlock_bh(&msk->pm.lock);
+
+	list_for_each_entry_safe(entry, tmp, &free_list, list) {
+		sock_kfree_s(sk, entry, sizeof(*entry));
+	}
+}
+
+int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
+					     struct mptcp_pm_addr_entry *entry)
+{
+	DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
+	struct mptcp_pm_addr_entry *match = NULL;
+	struct sock *sk = (struct sock *)msk;
+	struct mptcp_pm_addr_entry *e;
+	bool addr_match = false;
+	bool id_match = false;
+	int ret = -EINVAL;
+
+	bitmap_zero(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
+
+	spin_lock_bh(&msk->pm.lock);
+	list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
+		addr_match = mptcp_addresses_equal(&e->addr, &entry->addr, true);
+		if (addr_match && entry->addr.id == 0)
+			entry->addr.id = e->addr.id;
+		id_match = (e->addr.id == entry->addr.id);
+		if (addr_match && id_match) {
+			match = e;
+			break;
+		} else if (addr_match || id_match) {
+			break;
+		}
+		__set_bit(e->addr.id, id_bitmap);
+	}
+
+	if (!match && !addr_match && !id_match) {
+		/* Memory for the entry is allocated from the
+		 * sock option buffer.
+		 */
+		e = sock_kmalloc(sk, sizeof(*e), GFP_ATOMIC);
+		if (!e) {
+			spin_unlock_bh(&msk->pm.lock);
+			return -ENOMEM;
+		}
+
+		*e = *entry;
+		if (!e->addr.id)
+			e->addr.id = find_next_zero_bit(id_bitmap,
+							MPTCP_PM_MAX_ADDR_ID + 1,
+							1);
+		list_add_tail_rcu(&e->list, &msk->pm.userspace_pm_local_addr_list);
+		ret = e->addr.id;
+	} else if (match) {
+		ret = entry->addr.id;
+	}
+
+	spin_unlock_bh(&msk->pm.lock);
+	return ret;
+}
+
+int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
+						   unsigned int id,
+						   u8 *flags, int *ifindex)
+{
+	struct mptcp_pm_addr_entry *entry, *match = NULL;
+
+	*flags = 0;
+	*ifindex = 0;
+
+	spin_lock_bh(&msk->pm.lock);
+	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
+		if (id == entry->addr.id) {
+			match = entry;
+			break;
+		}
+	}
+	spin_unlock_bh(&msk->pm.lock);
+	if (match) {
+		*flags = match->flags;
+		*ifindex = match->ifindex;
+	}
+
+	return 0;
+}
+
+int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
+				    struct mptcp_addr_info *skc)
+{
+	struct mptcp_pm_addr_entry new_entry;
+	__be16 msk_sport =  ((struct inet_sock *)
+			     inet_sk((struct sock *)msk))->inet_sport;
+
+	memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
+	new_entry.addr = *skc;
+	new_entry.addr.id = 0;
+	new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
+
+	if (new_entry.addr.port == msk_sport)
+		new_entry.addr.port = 0;
+
+	return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry);
+}
+
+int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
+	struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
+	struct mptcp_pm_addr_entry addr_val;
+	struct mptcp_sock *msk;
+	int err = -EINVAL;
+	u32 token_val;
+
+	if (!addr || !token) {
+		GENL_SET_ERR_MSG(info, "missing required inputs");
+		return err;
+	}
+
+	token_val = nla_get_u32(token);
+
+	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
+	if (!msk) {
+		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
+		return err;
+	}
+
+	if (!mptcp_pm_is_userspace(msk)) {
+		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
+		goto announce_err;
+	}
+
+	err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
+	if (err < 0) {
+		GENL_SET_ERR_MSG(info, "error parsing local address");
+		goto announce_err;
+	}
+
+	if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
+		GENL_SET_ERR_MSG(info, "invalid addr id or flags");
+		goto announce_err;
+	}
+
+	err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val);
+	if (err < 0) {
+		GENL_SET_ERR_MSG(info, "did not match address and id");
+		goto announce_err;
+	}
+
+	lock_sock((struct sock *)msk);
+	spin_lock_bh(&msk->pm.lock);
+
+	if (mptcp_pm_alloc_anno_list(msk, &addr_val)) {
+		mptcp_pm_announce_addr(msk, &addr_val.addr, false);
+		mptcp_pm_nl_addr_send_ack(msk);
+	}
+
+	spin_unlock_bh(&msk->pm.lock);
+	release_sock((struct sock *)msk);
+
+	err = 0;
+ announce_err:
+	sock_put((struct sock *)msk);
+	return err;
+}
+
+int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
+	struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
+	struct mptcp_pm_addr_entry *match = NULL;
+	struct mptcp_pm_addr_entry *entry;
+	struct mptcp_sock *msk;
+	LIST_HEAD(free_list);
+	int err = -EINVAL;
+	u32 token_val;
+	u8 id_val;
+
+	if (!id || !token) {
+		GENL_SET_ERR_MSG(info, "missing required inputs");
+		return err;
+	}
+
+	id_val = nla_get_u8(id);
+	token_val = nla_get_u32(token);
+
+	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
+	if (!msk) {
+		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
+		return err;
+	}
+
+	if (!mptcp_pm_is_userspace(msk)) {
+		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
+		goto remove_err;
+	}
+
+	lock_sock((struct sock *)msk);
+
+	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
+		if (entry->addr.id == id_val) {
+			match = entry;
+			break;
+		}
+	}
+
+	if (!match) {
+		GENL_SET_ERR_MSG(info, "address with specified id not found");
+		release_sock((struct sock *)msk);
+		goto remove_err;
+	}
+
+	list_move(&match->list, &free_list);
+
+	mptcp_pm_remove_addrs_and_subflows(msk, &free_list);
+
+	release_sock((struct sock *)msk);
+
+	list_for_each_entry_safe(match, entry, &free_list, list) {
+		sock_kfree_s((struct sock *)msk, match, sizeof(*match));
+	}
+
+	err = 0;
+ remove_err:
+	sock_put((struct sock *)msk);
+	return err;
+}
+
+int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
+	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
+	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
+	struct mptcp_addr_info addr_r;
+	struct mptcp_addr_info addr_l;
+	struct mptcp_sock *msk;
+	int err = -EINVAL;
+	struct sock *sk;
+	u32 token_val;
+
+	if (!laddr || !raddr || !token) {
+		GENL_SET_ERR_MSG(info, "missing required inputs");
+		return err;
+	}
+
+	token_val = nla_get_u32(token);
+
+	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
+	if (!msk) {
+		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
+		return err;
+	}
+
+	if (!mptcp_pm_is_userspace(msk)) {
+		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
+		goto create_err;
+	}
+
+	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
+	if (err < 0) {
+		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
+		goto create_err;
+	}
+
+	if (addr_l.id == 0) {
+		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "missing local addr id");
+		goto create_err;
+	}
+
+	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
+	if (err < 0) {
+		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
+		goto create_err;
+	}
+
+	sk = &msk->sk.icsk_inet.sk;
+	lock_sock(sk);
+
+	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
+
+	release_sock(sk);
+
+ create_err:
+	sock_put((struct sock *)msk);
+	return err;
+}
+
+static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
+				      const struct mptcp_addr_info *local,
+				      const struct mptcp_addr_info *remote)
+{
+	struct sock *sk = &msk->sk.icsk_inet.sk;
+	struct mptcp_subflow_context *subflow;
+	struct sock *found = NULL;
+
+	if (local->family != remote->family)
+		return NULL;
+
+	lock_sock(sk);
+
+	mptcp_for_each_subflow(msk, subflow) {
+		const struct inet_sock *issk;
+		struct sock *ssk;
+
+		ssk = mptcp_subflow_tcp_sock(subflow);
+
+		if (local->family != ssk->sk_family)
+			continue;
+
+		issk = inet_sk(ssk);
+
+		switch (ssk->sk_family) {
+		case AF_INET:
+			if (issk->inet_saddr != local->addr.s_addr ||
+			    issk->inet_daddr != remote->addr.s_addr)
+				continue;
+			break;
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+		case AF_INET6: {
+			const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
+
+			if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
+			    !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
+				continue;
+			break;
+		}
+#endif
+		default:
+			continue;
+		}
+
+		if (issk->inet_sport == local->port &&
+		    issk->inet_dport == remote->port) {
+			found = ssk;
+			goto found;
+		}
+	}
+
+found:
+	release_sock(sk);
+
+	return found;
+}
+
+int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
+	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
+	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
+	struct mptcp_addr_info addr_l;
+	struct mptcp_addr_info addr_r;
+	struct mptcp_sock *msk;
+	struct sock *sk, *ssk;
+	int err = -EINVAL;
+	u32 token_val;
+
+	if (!laddr || !raddr || !token) {
+		GENL_SET_ERR_MSG(info, "missing required inputs");
+		return err;
+	}
+
+	token_val = nla_get_u32(token);
+
+	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
+	if (!msk) {
+		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
+		return err;
+	}
+
+	if (!mptcp_pm_is_userspace(msk)) {
+		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
+		goto destroy_err;
+	}
+
+	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
+	if (err < 0) {
+		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
+		goto destroy_err;
+	}
+
+	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
+	if (err < 0) {
+		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
+		goto destroy_err;
+	}
+
+	if (addr_l.family != addr_r.family) {
+		GENL_SET_ERR_MSG(info, "address families do not match");
+		goto destroy_err;
+	}
+
+	if (!addr_l.port || !addr_r.port) {
+		GENL_SET_ERR_MSG(info, "missing local or remote port");
+		goto destroy_err;
+	}
+
+	sk = &msk->sk.icsk_inet.sk;
+	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
+	if (ssk) {
+		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
+
+		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
+		mptcp_close_ssk(sk, ssk, subflow);
+		err = 0;
+	} else {
+		err = -ESRCH;
+	}
+
+ destroy_err:
+	sock_put((struct sock *)msk);
+	return err;
+}
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 5d529143ad77..52ed2c0ac901 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3097,6 +3097,7 @@ void mptcp_destroy_common(struct mptcp_sock *msk)
 	msk->rmem_fwd_alloc = 0;
 	mptcp_token_destroy(msk);
 	mptcp_pm_free_anno_list(msk);
+	mptcp_free_local_addr_list(msk);
 }
 
 static void mptcp_destroy(struct sock *sk)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 187c932deef0..f542aeaa5b09 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -11,6 +11,7 @@
 #include <net/tcp.h>
 #include <net/inet_connection_sock.h>
 #include <uapi/linux/mptcp.h>
+#include <net/genetlink.h>
 
 #define MPTCP_SUPPORTED_VERSION	1
 
@@ -208,6 +209,7 @@ struct mptcp_pm_data {
 	struct mptcp_addr_info local;
 	struct mptcp_addr_info remote;
 	struct list_head anno_list;
+	struct list_head userspace_pm_local_addr_list;
 
 	spinlock_t	lock;		/*protects the whole PM data */
 
@@ -228,6 +230,14 @@ struct mptcp_pm_data {
 	struct mptcp_rm_list rm_list_rx;
 };
 
+struct mptcp_pm_addr_entry {
+	struct list_head	list;
+	struct mptcp_addr_info	addr;
+	u8			flags;
+	int			ifindex;
+	struct socket		*lsk;
+};
+
 struct mptcp_data_frag {
 	struct list_head list;
 	u64 data_seq;
@@ -601,6 +611,9 @@ void mptcp_subflow_reset(struct sock *ssk);
 void mptcp_sock_graft(struct sock *sk, struct socket *parent);
 struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);
 
+bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
+			   const struct mptcp_addr_info *b, bool use_port);
+
 /* called with sk socket lock held */
 int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
 			    const struct mptcp_addr_info *remote);
@@ -743,6 +756,11 @@ u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
 void __init mptcp_pm_init(void);
 void mptcp_pm_data_init(struct mptcp_sock *msk);
 void mptcp_pm_data_reset(struct mptcp_sock *msk);
+int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
+			struct mptcp_addr_info *addr);
+int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
+			 bool require_family,
+			 struct mptcp_pm_addr_entry *entry);
 void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
 void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
@@ -763,6 +781,8 @@ void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
 			       const struct mptcp_rm_list *rm_list);
 void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
 void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
+bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
+			      const struct mptcp_pm_addr_entry *entry);
 void mptcp_pm_free_anno_list(struct mptcp_sock *msk);
 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
 struct mptcp_pm_add_entry *
@@ -771,14 +791,28 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 struct mptcp_pm_add_entry *
 mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 				const struct mptcp_addr_info *addr);
-int mptcp_pm_get_flags_and_ifindex_by_id(struct net *net, unsigned int id,
+int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
+					 unsigned int id,
 					 u8 *flags, int *ifindex);
+int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
+						   unsigned int id,
+						   u8 *flags, int *ifindex);
 
 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 			   const struct mptcp_addr_info *addr,
 			   bool echo);
 int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
+void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
+					struct list_head *rm_list);
+
+int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
+					     struct mptcp_pm_addr_entry *entry);
+void mptcp_free_local_addr_list(struct mptcp_sock *msk);
+int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info);
+int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info);
+int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info);
+int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info);
 
 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
 		 const struct sock *ssk, gfp_t gfp);
@@ -847,6 +881,7 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 			     struct mptcp_rm_list *rm_list);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
+int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 
 void __init mptcp_pm_nl_init(void);
 void mptcp_pm_nl_work(struct mptcp_sock *msk);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index a0e7af33fb26..6d59336a8e1e 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1468,7 +1468,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
 	if (local_id)
 		subflow_set_local_id(subflow, local_id);
 
-	mptcp_pm_get_flags_and_ifindex_by_id(sock_net(sk), local_id,
+	mptcp_pm_get_flags_and_ifindex_by_id(msk, local_id,
 					     &flags, &ifindex);
 	subflow->remote_key = msk->remote_key;
 	subflow->local_key = msk->local_key;