Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1139 insertions, 0 deletions

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
new file mode 100644
index 000000000..0d6f3d912
--- /dev/null
+++ b/net/mptcp/pm_netlink.c
@@ -0,0 +1,1139 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Multipath TCP
+ *
+ * Copyright (c) 2020, Red Hat, Inc.
+ */
+
+#define pr_fmt(fmt) "MPTCP: " fmt
+
+#include <linux/inet.h>
+#include <linux/kernel.h>
+#include <net/tcp.h>
+#include <net/netns/generic.h>
+#include <net/mptcp.h>
+#include <net/genetlink.h>
+#include <uapi/linux/mptcp.h>
+
+#include "protocol.h"
+#include "mib.h"
+
+/* forward declaration */
+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;
+	struct rcu_head		rcu;
+};
+
+struct mptcp_pm_add_entry {
+	struct list_head	list;
+	struct mptcp_addr_info	addr;
+	struct timer_list	add_timer;
+	struct mptcp_sock	*sock;
+	u8			retrans_times;
+};
+
+struct pm_nl_pernet {
+	/* protects pernet updates */
+	spinlock_t		lock;
+	struct list_head	local_addr_list;
+	unsigned int		addrs;
+	unsigned int		add_addr_signal_max;
+	unsigned int		add_addr_accept_max;
+	unsigned int		local_addr_max;
+	unsigned int		subflows_max;
+	unsigned int		next_id;
+};
+
+#define MPTCP_PM_ADDR_MAX	8
+#define ADD_ADDR_RETRANS_MAX	3
+
+static bool addresses_equal(const struct mptcp_addr_info *a,
+			    struct mptcp_addr_info *b, bool use_port)
+{
+	bool addr_equals = false;
+
+	if (a->family != b->family)
+		return false;
+
+	if (a->family == AF_INET)
+		addr_equals = a->addr.s_addr == b->addr.s_addr;
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	else
+		addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
+#endif
+
+	if (!addr_equals)
+		return false;
+	if (!use_port)
+		return true;
+
+	return a->port == b->port;
+}
+
+static bool address_zero(const struct mptcp_addr_info *addr)
+{
+	struct mptcp_addr_info zero;
+
+	memset(&zero, 0, sizeof(zero));
+	zero.family = addr->family;
+
+	return addresses_equal(addr, &zero, false);
+}
+
+static void local_address(const struct sock_common *skc,
+			  struct mptcp_addr_info *addr)
+{
+	addr->port = 0;
+	addr->family = skc->skc_family;
+	if (addr->family == AF_INET)
+		addr->addr.s_addr = skc->skc_rcv_saddr;
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	else if (addr->family == AF_INET6)
+		addr->addr6 = skc->skc_v6_rcv_saddr;
+#endif
+}
+
+static void remote_address(const struct sock_common *skc,
+			   struct mptcp_addr_info *addr)
+{
+	addr->family = skc->skc_family;
+	addr->port = skc->skc_dport;
+	if (addr->family == AF_INET)
+		addr->addr.s_addr = skc->skc_daddr;
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	else if (addr->family == AF_INET6)
+		addr->addr6 = skc->skc_v6_daddr;
+#endif
+}
+
+static bool lookup_subflow_by_saddr(const struct list_head *list,
+				    struct mptcp_addr_info *saddr)
+{
+	struct mptcp_subflow_context *subflow;
+	struct mptcp_addr_info cur;
+	struct sock_common *skc;
+
+	list_for_each_entry(subflow, list, node) {
+		skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
+
+		local_address(skc, &cur);
+		if (addresses_equal(&cur, saddr, false))
+			return true;
+	}
+
+	return false;
+}
+
+static struct mptcp_pm_addr_entry *
+select_local_address(const struct pm_nl_pernet *pernet,
+		     struct mptcp_sock *msk)
+{
+	struct mptcp_pm_addr_entry *entry, *ret = NULL;
+
+	rcu_read_lock();
+	spin_lock_bh(&msk->join_list_lock);
+	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
+		if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
+			continue;
+
+		/* avoid any address already in use by subflows and
+		 * pending join
+		 */
+		if (entry->addr.family == ((struct sock *)msk)->sk_family &&
+		    !lookup_subflow_by_saddr(&msk->conn_list, &entry->addr) &&
+		    !lookup_subflow_by_saddr(&msk->join_list, &entry->addr)) {
+			ret = entry;
+			break;
+		}
+	}
+	spin_unlock_bh(&msk->join_list_lock);
+	rcu_read_unlock();
+	return ret;
+}
+
+static struct mptcp_pm_addr_entry *
+select_signal_address(struct pm_nl_pernet *pernet, unsigned int pos)
+{
+	struct mptcp_pm_addr_entry *entry, *ret = NULL;
+	int i = 0;
+
+	rcu_read_lock();
+	/* do not keep any additional per socket state, just signal
+	 * the address list in order.
+	 * Note: removal from the local address list during the msk life-cycle
+	 * can lead to additional addresses not being announced.
+	 */
+	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
+		if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
+			continue;
+		if (i++ == pos) {
+			ret = entry;
+			break;
+		}
+	}
+	rcu_read_unlock();
+	return ret;
+}
+
+static void check_work_pending(struct mptcp_sock *msk)
+{
+	if (msk->pm.add_addr_signaled == msk->pm.add_addr_signal_max &&
+	    (msk->pm.local_addr_used == msk->pm.local_addr_max ||
+	     msk->pm.subflows == msk->pm.subflows_max))
+		WRITE_ONCE(msk->pm.work_pending, false);
+}
+
+static struct mptcp_pm_add_entry *
+lookup_anno_list_by_saddr(struct mptcp_sock *msk,
+			  struct mptcp_addr_info *addr)
+{
+	struct mptcp_pm_add_entry *entry;
+
+	list_for_each_entry(entry, &msk->pm.anno_list, list) {
+		if (addresses_equal(&entry->addr, addr, false))
+			return entry;
+	}
+
+	return NULL;
+}
+
+static void mptcp_pm_add_timer(struct timer_list *timer)
+{
+	struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
+	struct mptcp_sock *msk = entry->sock;
+	struct sock *sk = (struct sock *)msk;
+
+	pr_debug("msk=%p", msk);
+
+	if (!msk)
+		return;
+
+	if (inet_sk_state_load(sk) == TCP_CLOSE)
+		return;
+
+	if (!entry->addr.id)
+		return;
+
+	if (mptcp_pm_should_add_signal(msk)) {
+		sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
+		goto out;
+	}
+
+	spin_lock_bh(&msk->pm.lock);
+
+	if (!mptcp_pm_should_add_signal(msk)) {
+		pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
+		mptcp_pm_announce_addr(msk, &entry->addr, false);
+		entry->retrans_times++;
+	}
+
+	if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
+		sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX);
+
+	spin_unlock_bh(&msk->pm.lock);
+
+out:
+	__sock_put(sk);
+}
+
+struct mptcp_pm_add_entry *
+mptcp_pm_del_add_timer(struct mptcp_sock *msk,
+		       struct mptcp_addr_info *addr)
+{
+	struct mptcp_pm_add_entry *entry;
+	struct sock *sk = (struct sock *)msk;
+
+	spin_lock_bh(&msk->pm.lock);
+	entry = lookup_anno_list_by_saddr(msk, addr);
+	if (entry)
+		entry->retrans_times = ADD_ADDR_RETRANS_MAX;
+	spin_unlock_bh(&msk->pm.lock);
+
+	if (entry)
+		sk_stop_timer_sync(sk, &entry->add_timer);
+
+	return entry;
+}
+
+static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
+				     struct mptcp_pm_addr_entry *entry)
+{
+	struct mptcp_pm_add_entry *add_entry = NULL;
+	struct sock *sk = (struct sock *)msk;
+
+	if (lookup_anno_list_by_saddr(msk, &entry->addr))
+		return false;
+
+	add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
+	if (!add_entry)
+		return false;
+
+	list_add(&add_entry->list, &msk->pm.anno_list);
+
+	add_entry->addr = entry->addr;
+	add_entry->sock = msk;
+	add_entry->retrans_times = 0;
+
+	timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
+	sk_reset_timer(sk, &add_entry->add_timer, jiffies + TCP_RTO_MAX);
+
+	return true;
+}
+
+void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
+{
+	struct mptcp_pm_add_entry *entry, *tmp;
+	struct sock *sk = (struct sock *)msk;
+	LIST_HEAD(free_list);
+
+	pr_debug("msk=%p", msk);
+
+	spin_lock_bh(&msk->pm.lock);
+	list_splice_init(&msk->pm.anno_list, &free_list);
+	spin_unlock_bh(&msk->pm.lock);
+
+	list_for_each_entry_safe(entry, tmp, &free_list, list) {
+		sk_stop_timer_sync(sk, &entry->add_timer);
+		kfree(entry);
+	}
+}
+
+static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
+{
+	struct mptcp_addr_info remote = { 0 };
+	struct sock *sk = (struct sock *)msk;
+	struct mptcp_pm_addr_entry *local;
+	struct pm_nl_pernet *pernet;
+
+	pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
+
+	pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
+		 msk->pm.local_addr_used, msk->pm.local_addr_max,
+		 msk->pm.add_addr_signaled, msk->pm.add_addr_signal_max,
+		 msk->pm.subflows, msk->pm.subflows_max);
+
+	/* check first for announce */
+	if (msk->pm.add_addr_signaled < msk->pm.add_addr_signal_max) {
+		local = select_signal_address(pernet,
+					      msk->pm.add_addr_signaled);
+
+		if (local) {
+			if (mptcp_pm_alloc_anno_list(msk, local)) {
+				msk->pm.add_addr_signaled++;
+				mptcp_pm_announce_addr(msk, &local->addr, false);
+			}
+		} else {
+			/* pick failed, avoid fourther attempts later */
+			msk->pm.local_addr_used = msk->pm.add_addr_signal_max;
+		}
+
+		check_work_pending(msk);
+	}
+
+	/* check if should create a new subflow */
+	if (msk->pm.local_addr_used < msk->pm.local_addr_max &&
+	    msk->pm.subflows < msk->pm.subflows_max) {
+		remote_address((struct sock_common *)sk, &remote);
+
+		local = select_local_address(pernet, msk);
+		if (local) {
+			msk->pm.local_addr_used++;
+			msk->pm.subflows++;
+			check_work_pending(msk);
+			spin_unlock_bh(&msk->pm.lock);
+			__mptcp_subflow_connect(sk, &local->addr, &remote);
+			spin_lock_bh(&msk->pm.lock);
+			return;
+		}
+
+		/* lookup failed, avoid fourther attempts later */
+		msk->pm.local_addr_used = msk->pm.local_addr_max;
+		check_work_pending(msk);
+	}
+}
+
+void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
+{
+	mptcp_pm_create_subflow_or_signal_addr(msk);
+}
+
+void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
+{
+	mptcp_pm_create_subflow_or_signal_addr(msk);
+}
+
+void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
+{
+	struct sock *sk = (struct sock *)msk;
+	struct mptcp_addr_info remote;
+	struct mptcp_addr_info local;
+
+	pr_debug("accepted %d:%d remote family %d",
+		 msk->pm.add_addr_accepted, msk->pm.add_addr_accept_max,
+		 msk->pm.remote.family);
+	msk->pm.add_addr_accepted++;
+	msk->pm.subflows++;
+	if (msk->pm.add_addr_accepted >= msk->pm.add_addr_accept_max ||
+	    msk->pm.subflows >= msk->pm.subflows_max)
+		WRITE_ONCE(msk->pm.accept_addr, false);
+
+	/* connect to the specified remote address, using whatever
+	 * local address the routing configuration will pick.
+	 */
+	remote = msk->pm.remote;
+	if (!remote.port)
+		remote.port = sk->sk_dport;
+	memset(&local, 0, sizeof(local));
+	local.family = remote.family;
+
+	spin_unlock_bh(&msk->pm.lock);
+	__mptcp_subflow_connect((struct sock *)msk, &local, &remote);
+	spin_lock_bh(&msk->pm.lock);
+
+	mptcp_pm_announce_addr(msk, &remote, true);
+}
+
+void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
+{
+	struct mptcp_subflow_context *subflow, *tmp;
+	struct sock *sk = (struct sock *)msk;
+
+	pr_debug("address rm_id %d", msk->pm.rm_id);
+
+	if (!msk->pm.rm_id)
+		return;
+
+	if (list_empty(&msk->conn_list))
+		return;
+
+	list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
+		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+		int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
+		long timeout = 0;
+
+		if (msk->pm.rm_id != subflow->remote_id)
+			continue;
+
+		spin_unlock_bh(&msk->pm.lock);
+		mptcp_subflow_shutdown(sk, ssk, how);
+		__mptcp_close_ssk(sk, ssk, subflow, timeout);
+		spin_lock_bh(&msk->pm.lock);
+
+		msk->pm.add_addr_accepted--;
+		msk->pm.subflows--;
+		WRITE_ONCE(msk->pm.accept_addr, true);
+
+		__MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMADDR);
+
+		break;
+	}
+}
+
+void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id)
+{
+	struct mptcp_subflow_context *subflow, *tmp;
+	struct sock *sk = (struct sock *)msk;
+
+	pr_debug("subflow rm_id %d", rm_id);
+
+	if (!rm_id)
+		return;
+
+	if (list_empty(&msk->conn_list))
+		return;
+
+	list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
+		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+		int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
+		long timeout = 0;
+
+		if (rm_id != subflow->local_id)
+			continue;
+
+		spin_unlock_bh(&msk->pm.lock);
+		mptcp_subflow_shutdown(sk, ssk, how);
+		__mptcp_close_ssk(sk, ssk, subflow, timeout);
+		spin_lock_bh(&msk->pm.lock);
+
+		msk->pm.local_addr_used--;
+		msk->pm.subflows--;
+
+		__MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
+
+		break;
+	}
+}
+
+static bool address_use_port(struct mptcp_pm_addr_entry *entry)
+{
+	return (entry->addr.flags &
+		(MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
+		MPTCP_PM_ADDR_FLAG_SIGNAL;
+}
+
+static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
+					     struct mptcp_pm_addr_entry *entry)
+{
+	struct mptcp_pm_addr_entry *cur;
+	int ret = -EINVAL;
+
+	spin_lock_bh(&pernet->lock);
+	/* to keep the code simple, don't do IDR-like allocation for address ID,
+	 * just bail when we exceed limits
+	 */
+	if (pernet->next_id > 255)
+		goto out;
+	if (pernet->addrs >= MPTCP_PM_ADDR_MAX)
+		goto out;
+
+	/* do not insert duplicate address, differentiate on port only
+	 * 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)))
+			goto out;
+	}
+
+	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)
+		pernet->add_addr_signal_max++;
+	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
+		pernet->local_addr_max++;
+
+	entry->addr.id = pernet->next_id++;
+	pernet->addrs++;
+	list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
+	ret = entry->addr.id;
+
+out:
+	spin_unlock_bh(&pernet->lock);
+	return ret;
+}
+
+int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
+{
+	struct mptcp_pm_addr_entry *entry;
+	struct mptcp_addr_info skc_local;
+	struct mptcp_addr_info msk_local;
+	struct pm_nl_pernet *pernet;
+	int ret = -1;
+
+	if (WARN_ON_ONCE(!msk))
+		return -1;
+
+	/* The 0 ID mapping is defined by the first subflow, copied into the msk
+	 * addr
+	 */
+	local_address((struct sock_common *)msk, &msk_local);
+	local_address((struct sock_common *)skc, &skc_local);
+	if (addresses_equal(&msk_local, &skc_local, false))
+		return 0;
+
+	if (address_zero(&skc_local))
+		return 0;
+
+	pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
+		if (addresses_equal(&entry->addr, &skc_local, false)) {
+			ret = entry->addr.id;
+			break;
+		}
+	}
+	rcu_read_unlock();
+	if (ret >= 0)
+		return ret;
+
+	/* address not found, add to local list */
+	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
+	if (!entry)
+		return -ENOMEM;
+
+	entry->addr = skc_local;
+	entry->addr.ifindex = 0;
+	entry->addr.flags = 0;
+	ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
+	if (ret < 0)
+		kfree(entry);
+
+	return ret;
+}
+
+void mptcp_pm_nl_data_init(struct mptcp_sock *msk)
+{
+	struct mptcp_pm_data *pm = &msk->pm;
+	struct pm_nl_pernet *pernet;
+	bool subflows;
+
+	pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
+
+	pm->add_addr_signal_max = READ_ONCE(pernet->add_addr_signal_max);
+	pm->add_addr_accept_max = READ_ONCE(pernet->add_addr_accept_max);
+	pm->local_addr_max = READ_ONCE(pernet->local_addr_max);
+	pm->subflows_max = READ_ONCE(pernet->subflows_max);
+	subflows = !!pm->subflows_max;
+	WRITE_ONCE(pm->work_pending, (!!pm->local_addr_max && subflows) ||
+		   !!pm->add_addr_signal_max);
+	WRITE_ONCE(pm->accept_addr, !!pm->add_addr_accept_max && subflows);
+	WRITE_ONCE(pm->accept_subflow, subflows);
+}
+
+#define MPTCP_PM_CMD_GRP_OFFSET	0
+
+static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
+	[MPTCP_PM_CMD_GRP_OFFSET]	= { .name = MPTCP_PM_CMD_GRP_NAME, },
+};
+
+static const struct nla_policy
+mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
+	[MPTCP_PM_ADDR_ATTR_FAMILY]	= { .type	= NLA_U16,	},
+	[MPTCP_PM_ADDR_ATTR_ID]		= { .type	= NLA_U8,	},
+	[MPTCP_PM_ADDR_ATTR_ADDR4]	= { .type	= NLA_U32,	},
+	[MPTCP_PM_ADDR_ATTR_ADDR6]	=
+		NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
+	[MPTCP_PM_ADDR_ATTR_PORT]	= { .type	= NLA_U16	},
+	[MPTCP_PM_ADDR_ATTR_FLAGS]	= { .type	= NLA_U32	},
+	[MPTCP_PM_ADDR_ATTR_IF_IDX]     = { .type	= NLA_S32	},
+};
+
+static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
+	[MPTCP_PM_ATTR_ADDR]		=
+					NLA_POLICY_NESTED(mptcp_pm_addr_policy),
+	[MPTCP_PM_ATTR_RCV_ADD_ADDRS]	= { .type	= NLA_U32,	},
+	[MPTCP_PM_ATTR_SUBFLOWS]	= { .type	= NLA_U32,	},
+};
+
+static int mptcp_pm_family_to_addr(int family)
+{
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	if (family == AF_INET6)
+		return MPTCP_PM_ADDR_ATTR_ADDR6;
+#endif
+	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)
+{
+	struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
+	int err, addr_addr;
+
+	if (!attr) {
+		GENL_SET_ERR_MSG(info, "missing address info");
+		return -EINVAL;
+	}
+
+	/* no validation needed - was already done via nested policy */
+	err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
+					  mptcp_pm_addr_policy, info->extack);
+	if (err)
+		return err;
+
+	memset(entry, 0, sizeof(*entry));
+	if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
+		if (!require_family)
+			goto skip_family;
+
+		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
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	    && entry->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);
+	if (!tb[addr_addr]) {
+		NL_SET_ERR_MSG_ATTR(info->extack, attr,
+				    "missing address data");
+		return -EINVAL;
+	}
+
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	if (entry->addr.family == AF_INET6)
+		entry->addr.addr6 = nla_get_in6_addr(tb[addr_addr]);
+	else
+#endif
+		entry->addr.addr.s_addr = nla_get_in_addr(tb[addr_addr]);
+
+skip_family:
+	if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
+		u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
+
+		entry->addr.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->addr.flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
+
+	return 0;
+}
+
+static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
+{
+	return net_generic(genl_info_net(info), pm_nl_pernet_id);
+}
+
+static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
+	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
+	struct mptcp_pm_addr_entry addr, *entry;
+	int ret;
+
+	ret = mptcp_pm_parse_addr(attr, info, true, &addr);
+	if (ret < 0)
+		return ret;
+
+	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry) {
+		GENL_SET_ERR_MSG(info, "can't allocate addr");
+		return -ENOMEM;
+	}
+
+	*entry = addr;
+	ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
+	if (ret < 0) {
+		GENL_SET_ERR_MSG(info, "too many addresses or duplicate one");
+		kfree(entry);
+		return ret;
+	}
+
+	return 0;
+}
+
+static struct mptcp_pm_addr_entry *
+__lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
+{
+	struct mptcp_pm_addr_entry *entry;
+
+	list_for_each_entry(entry, &pernet->local_addr_list, list) {
+		if (entry->addr.id == id)
+			return entry;
+	}
+	return NULL;
+}
+
+static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
+				      struct mptcp_addr_info *addr)
+{
+	struct mptcp_pm_add_entry *entry;
+
+	entry = mptcp_pm_del_add_timer(msk, addr);
+	if (entry) {
+		list_del(&entry->list);
+		kfree(entry);
+		return true;
+	}
+
+	return false;
+}
+
+static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
+				      struct mptcp_addr_info *addr,
+				      bool force)
+{
+	bool ret;
+
+	ret = remove_anno_list_by_saddr(msk, addr);
+	if (ret || force) {
+		spin_lock_bh(&msk->pm.lock);
+		mptcp_pm_remove_addr(msk, addr->id);
+		spin_unlock_bh(&msk->pm.lock);
+	}
+	return ret;
+}
+
+static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
+						   struct mptcp_addr_info *addr)
+{
+	struct mptcp_sock *msk;
+	long s_slot = 0, s_num = 0;
+
+	pr_debug("remove_id=%d", addr->id);
+
+	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
+		struct sock *sk = (struct sock *)msk;
+		bool remove_subflow;
+
+		if (list_empty(&msk->conn_list)) {
+			mptcp_pm_remove_anno_addr(msk, addr, false);
+			goto next;
+		}
+
+		lock_sock(sk);
+		remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
+		mptcp_pm_remove_anno_addr(msk, addr, remove_subflow);
+		if (remove_subflow)
+			mptcp_pm_remove_subflow(msk, addr->id);
+		release_sock(sk);
+
+next:
+		sock_put(sk);
+		cond_resched();
+	}
+
+	return 0;
+}
+
+static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
+	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
+	struct mptcp_pm_addr_entry addr, *entry;
+	int ret;
+
+	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
+	if (ret < 0)
+		return ret;
+
+	spin_lock_bh(&pernet->lock);
+	entry = __lookup_addr_by_id(pernet, addr.addr.id);
+	if (!entry) {
+		GENL_SET_ERR_MSG(info, "address not found");
+		spin_unlock_bh(&pernet->lock);
+		return -EINVAL;
+	}
+	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)
+		pernet->add_addr_signal_max--;
+	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
+		pernet->local_addr_max--;
+
+	pernet->addrs--;
+	list_del_rcu(&entry->list);
+	spin_unlock_bh(&pernet->lock);
+
+	mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), &entry->addr);
+	kfree_rcu(entry, rcu);
+
+	return ret;
+}
+
+static void __flush_addrs(struct pm_nl_pernet *pernet)
+{
+	while (!list_empty(&pernet->local_addr_list)) {
+		struct mptcp_pm_addr_entry *cur;
+
+		cur = list_entry(pernet->local_addr_list.next,
+				 struct mptcp_pm_addr_entry, list);
+		list_del_rcu(&cur->list);
+		kfree_rcu(cur, rcu);
+	}
+}
+
+static void __reset_counters(struct pm_nl_pernet *pernet)
+{
+	pernet->add_addr_signal_max = 0;
+	pernet->add_addr_accept_max = 0;
+	pernet->local_addr_max = 0;
+	pernet->addrs = 0;
+}
+
+static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
+{
+	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
+
+	spin_lock_bh(&pernet->lock);
+	__flush_addrs(pernet);
+	__reset_counters(pernet);
+	spin_unlock_bh(&pernet->lock);
+	return 0;
+}
+
+static int mptcp_nl_fill_addr(struct sk_buff *skb,
+			      struct mptcp_pm_addr_entry *entry)
+{
+	struct mptcp_addr_info *addr = &entry->addr;
+	struct nlattr *attr;
+
+	attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
+	if (!attr)
+		return -EMSGSIZE;
+
+	if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
+		goto nla_put_failure;
+	if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
+		goto nla_put_failure;
+	if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->addr.flags))
+		goto nla_put_failure;
+	if (entry->addr.ifindex &&
+	    nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->addr.ifindex))
+		goto nla_put_failure;
+
+	if (addr->family == AF_INET &&
+	    nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
+			    addr->addr.s_addr))
+		goto nla_put_failure;
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	else if (addr->family == AF_INET6 &&
+		 nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
+		goto nla_put_failure;
+#endif
+	nla_nest_end(skb, attr);
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(skb, attr);
+	return -EMSGSIZE;
+}
+
+static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
+	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
+	struct mptcp_pm_addr_entry addr, *entry;
+	struct sk_buff *msg;
+	void *reply;
+	int ret;
+
+	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
+	if (ret < 0)
+		return ret;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
+				  info->genlhdr->cmd);
+	if (!reply) {
+		GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
+		ret = -EMSGSIZE;
+		goto fail;
+	}
+
+	spin_lock_bh(&pernet->lock);
+	entry = __lookup_addr_by_id(pernet, addr.addr.id);
+	if (!entry) {
+		GENL_SET_ERR_MSG(info, "address not found");
+		ret = -EINVAL;
+		goto unlock_fail;
+	}
+
+	ret = mptcp_nl_fill_addr(msg, entry);
+	if (ret)
+		goto unlock_fail;
+
+	genlmsg_end(msg, reply);
+	ret = genlmsg_reply(msg, info);
+	spin_unlock_bh(&pernet->lock);
+	return ret;
+
+unlock_fail:
+	spin_unlock_bh(&pernet->lock);
+
+fail:
+	nlmsg_free(msg);
+	return ret;
+}
+
+static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
+				   struct netlink_callback *cb)
+{
+	struct net *net = sock_net(msg->sk);
+	struct mptcp_pm_addr_entry *entry;
+	struct pm_nl_pernet *pernet;
+	int id = cb->args[0];
+	void *hdr;
+
+	pernet = net_generic(net, pm_nl_pernet_id);
+
+	spin_lock_bh(&pernet->lock);
+	list_for_each_entry(entry, &pernet->local_addr_list, list) {
+		if (entry->addr.id <= id)
+			continue;
+
+		hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
+				  cb->nlh->nlmsg_seq, &mptcp_genl_family,
+				  NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
+		if (!hdr)
+			break;
+
+		if (mptcp_nl_fill_addr(msg, entry) < 0) {
+			genlmsg_cancel(msg, hdr);
+			break;
+		}
+
+		id = entry->addr.id;
+		genlmsg_end(msg, hdr);
+	}
+	spin_unlock_bh(&pernet->lock);
+
+	cb->args[0] = id;
+	return msg->len;
+}
+
+static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
+{
+	struct nlattr *attr = info->attrs[id];
+
+	if (!attr)
+		return 0;
+
+	*limit = nla_get_u32(attr);
+	if (*limit > MPTCP_PM_ADDR_MAX) {
+		GENL_SET_ERR_MSG(info, "limit greater than maximum");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int
+mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
+{
+	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
+	unsigned int rcv_addrs, subflows;
+	int ret;
+
+	spin_lock_bh(&pernet->lock);
+	rcv_addrs = pernet->add_addr_accept_max;
+	ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
+	if (ret)
+		goto unlock;
+
+	subflows = pernet->subflows_max;
+	ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
+	if (ret)
+		goto unlock;
+
+	WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
+	WRITE_ONCE(pernet->subflows_max, subflows);
+
+unlock:
+	spin_unlock_bh(&pernet->lock);
+	return ret;
+}
+
+static int
+mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
+{
+	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
+	struct sk_buff *msg;
+	void *reply;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
+				  MPTCP_PM_CMD_GET_LIMITS);
+	if (!reply)
+		goto fail;
+
+	if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
+			READ_ONCE(pernet->add_addr_accept_max)))
+		goto fail;
+
+	if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
+			READ_ONCE(pernet->subflows_max)))
+		goto fail;
+
+	genlmsg_end(msg, reply);
+	return genlmsg_reply(msg, info);
+
+fail:
+	GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
+	nlmsg_free(msg);
+	return -EMSGSIZE;
+}
+
+static const struct genl_small_ops mptcp_pm_ops[] = {
+	{
+		.cmd    = MPTCP_PM_CMD_ADD_ADDR,
+		.doit   = mptcp_nl_cmd_add_addr,
+		.flags  = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd    = MPTCP_PM_CMD_DEL_ADDR,
+		.doit   = mptcp_nl_cmd_del_addr,
+		.flags  = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd    = MPTCP_PM_CMD_FLUSH_ADDRS,
+		.doit   = mptcp_nl_cmd_flush_addrs,
+		.flags  = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd    = MPTCP_PM_CMD_GET_ADDR,
+		.doit   = mptcp_nl_cmd_get_addr,
+		.dumpit   = mptcp_nl_cmd_dump_addrs,
+	},
+	{
+		.cmd    = MPTCP_PM_CMD_SET_LIMITS,
+		.doit   = mptcp_nl_cmd_set_limits,
+		.flags  = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd    = MPTCP_PM_CMD_GET_LIMITS,
+		.doit   = mptcp_nl_cmd_get_limits,
+	},
+};
+
+static struct genl_family mptcp_genl_family __ro_after_init = {
+	.name		= MPTCP_PM_NAME,
+	.version	= MPTCP_PM_VER,
+	.maxattr	= MPTCP_PM_ATTR_MAX,
+	.policy		= mptcp_pm_policy,
+	.netnsok	= true,
+	.module		= THIS_MODULE,
+	.small_ops	= mptcp_pm_ops,
+	.n_small_ops	= ARRAY_SIZE(mptcp_pm_ops),
+	.mcgrps		= mptcp_pm_mcgrps,
+	.n_mcgrps	= ARRAY_SIZE(mptcp_pm_mcgrps),
+};
+
+static int __net_init pm_nl_init_net(struct net *net)
+{
+	struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
+
+	INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
+	__reset_counters(pernet);
+	pernet->next_id = 1;
+	spin_lock_init(&pernet->lock);
+	return 0;
+}
+
+static void __net_exit pm_nl_exit_net(struct list_head *net_list)
+{
+	struct net *net;
+
+	list_for_each_entry(net, net_list, exit_list) {
+		/* net is removed from namespace list, can't race with
+		 * other modifiers
+		 */
+		__flush_addrs(net_generic(net, pm_nl_pernet_id));
+	}
+}
+
+static struct pernet_operations mptcp_pm_pernet_ops = {
+	.init = pm_nl_init_net,
+	.exit_batch = pm_nl_exit_net,
+	.id = &pm_nl_pernet_id,
+	.size = sizeof(struct pm_nl_pernet),
+};
+
+void __init mptcp_pm_nl_init(void)
+{
+	if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
+		panic("Failed to register MPTCP PM pernet subsystem.\n");
+
+	if (genl_register_family(&mptcp_genl_family))
+		panic("Failed to register MPTCP PM netlink family\n");
+}