1 files changed, 308 insertions, 153 deletions

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index bc97cc30f013..a3d477059b11 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -6,6 +6,11 @@
 
 #include "protocol.h"
 #include "mib.h"
+#include "mptcp_pm_gen.h"
+
+#define mptcp_for_each_userspace_pm_addr(__msk, __entry)			\
+	list_for_each_entry(__entry,						\
+			    &((__msk)->pm.userspace_pm_local_addr_list), list)
 
 void mptcp_free_local_addr_list(struct mptcp_sock *msk)
 {
@@ -25,6 +30,19 @@ void mptcp_free_local_addr_list(struct mptcp_sock *msk)
 	}
 }
 
+static struct mptcp_pm_addr_entry *
+mptcp_userspace_pm_lookup_addr(struct mptcp_sock *msk,
+			       const struct mptcp_addr_info *addr)
+{
+	struct mptcp_pm_addr_entry *entry;
+
+	mptcp_for_each_userspace_pm_addr(msk, entry) {
+		if (mptcp_addresses_equal(&entry->addr, addr, false))
+			return entry;
+	}
+	return NULL;
+}
+
 static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
 						    struct mptcp_pm_addr_entry *entry,
 						    bool needs_id)
@@ -40,7 +58,7 @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
 	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) {
+	mptcp_for_each_userspace_pm_addr(msk, e) {
 		addr_match = mptcp_addresses_equal(&e->addr, &entry->addr, true);
 		if (addr_match && entry->addr.id == 0 && needs_id)
 			entry->addr.id = e->addr.id;
@@ -89,59 +107,43 @@ append_err:
 static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
 						struct mptcp_pm_addr_entry *addr)
 {
-	struct mptcp_pm_addr_entry *entry, *tmp;
+	struct sock *sk = (struct sock *)msk;
+	struct mptcp_pm_addr_entry *entry;
 
-	list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
-		if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
-			/* TODO: a refcount is needed because the entry can
-			 * be used multiple times (e.g. fullmesh mode).
-			 */
-			list_del_rcu(&entry->list);
-			kfree(entry);
-			msk->pm.local_addr_used--;
-			return 0;
-		}
-	}
+	entry = mptcp_userspace_pm_lookup_addr(msk, &addr->addr);
+	if (!entry)
+		return -EINVAL;
 
-	return -EINVAL;
+	/* TODO: a refcount is needed because the entry can
+	 * be used multiple times (e.g. fullmesh mode).
+	 */
+	list_del_rcu(&entry->list);
+	sock_kfree_s(sk, entry, sizeof(*entry));
+	msk->pm.local_addr_used--;
+	return 0;
 }
 
-int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
-						   unsigned int id,
-						   u8 *flags, int *ifindex)
+static struct mptcp_pm_addr_entry *
+mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
 {
-	struct mptcp_pm_addr_entry *entry, *match = NULL;
+	struct mptcp_pm_addr_entry *entry;
 
-	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;
+	mptcp_for_each_userspace_pm_addr(msk, entry) {
+		if (entry->addr.id == id)
+			return entry;
 	}
-
-	return 0;
+	return NULL;
 }
 
 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
 				    struct mptcp_addr_info *skc)
 {
-	struct mptcp_pm_addr_entry *entry = NULL, *e, new_entry;
+	struct mptcp_pm_addr_entry *entry = NULL, new_entry;
 	__be16 msk_sport =  ((struct inet_sock *)
 			     inet_sk((struct sock *)msk))->inet_sport;
 
 	spin_lock_bh(&msk->pm.lock);
-	list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
-		if (mptcp_addresses_equal(&e->addr, skc, false)) {
-			entry = e;
-			break;
-		}
-	}
+	entry = mptcp_userspace_pm_lookup_addr(msk, skc);
 	spin_unlock_bh(&msk->pm.lock);
 	if (entry)
 		return entry->addr.id;
@@ -157,36 +159,64 @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
 	return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry, true);
 }
 
-int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
+bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
+				  struct mptcp_addr_info *skc)
+{
+	struct mptcp_pm_addr_entry *entry;
+	bool backup;
+
+	spin_lock_bh(&msk->pm.lock);
+	entry = mptcp_userspace_pm_lookup_addr(msk, skc);
+	backup = entry && !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+	spin_unlock_bh(&msk->pm.lock);
+
+	return backup;
+}
+
+static struct mptcp_sock *mptcp_userspace_pm_get_sock(const struct genl_info *info)
 {
 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
+	struct mptcp_sock *msk;
+
+	if (!token) {
+		GENL_SET_ERR_MSG(info, "missing required token");
+		return NULL;
+	}
+
+	msk = mptcp_token_get_sock(genl_info_net(info), nla_get_u32(token));
+	if (!msk) {
+		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
+		return NULL;
+	}
+
+	if (!mptcp_pm_is_userspace(msk)) {
+		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
+		sock_put((struct sock *)msk);
+		return NULL;
+	}
+
+	return msk;
+}
+
+int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
+{
 	struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
 	struct mptcp_pm_addr_entry addr_val;
 	struct mptcp_sock *msk;
 	int err = -EINVAL;
 	struct sock *sk;
-	u32 token_val;
 
-	if (!addr || !token) {
-		GENL_SET_ERR_MSG(info, "missing required inputs");
+	if (!addr) {
+		GENL_SET_ERR_MSG(info, "missing required address");
 		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");
+	msk = mptcp_userspace_pm_get_sock(info);
+	if (!msk)
 		return err;
-	}
 
 	sk = (struct sock *)msk;
 
-	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");
@@ -257,40 +287,48 @@ remove_err:
 	return err;
 }
 
+void mptcp_pm_remove_addr_entry(struct mptcp_sock *msk,
+				struct mptcp_pm_addr_entry *entry)
+{
+	struct mptcp_rm_list alist = { .nr = 0 };
+	int anno_nr = 0;
+
+	/* only delete if either announced or matching a subflow */
+	if (mptcp_remove_anno_list_by_saddr(msk, &entry->addr))
+		anno_nr++;
+	else if (!mptcp_lookup_subflow_by_saddr(&msk->conn_list, &entry->addr))
+		return;
+
+	alist.ids[alist.nr++] = entry->addr.id;
+
+	spin_lock_bh(&msk->pm.lock);
+	msk->pm.add_addr_signaled -= anno_nr;
+	mptcp_pm_remove_addr(msk, &alist);
+	spin_unlock_bh(&msk->pm.lock);
+}
+
 int mptcp_pm_nl_remove_doit(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_pm_addr_entry *match;
 	struct mptcp_sock *msk;
-	LIST_HEAD(free_list);
 	int err = -EINVAL;
 	struct sock *sk;
-	u32 token_val;
 	u8 id_val;
 
-	if (!id || !token) {
-		GENL_SET_ERR_MSG(info, "missing required inputs");
+	if (!id) {
+		GENL_SET_ERR_MSG(info, "missing required ID");
 		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");
+	msk = mptcp_userspace_pm_get_sock(info);
+	if (!msk)
 		return err;
-	}
 
 	sk = (struct sock *)msk;
 
-	if (!mptcp_pm_is_userspace(msk)) {
-		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
-		goto out;
-	}
-
 	if (id_val == 0) {
 		err = mptcp_userspace_pm_remove_id_zero_address(msk, info);
 		goto out;
@@ -298,28 +336,23 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 
 	lock_sock(sk);
 
-	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
-		if (entry->addr.id == id_val) {
-			match = entry;
-			break;
-		}
-	}
-
+	spin_lock_bh(&msk->pm.lock);
+	match = mptcp_userspace_pm_lookup_addr_by_id(msk, id_val);
 	if (!match) {
 		GENL_SET_ERR_MSG(info, "address with specified id not found");
+		spin_unlock_bh(&msk->pm.lock);
 		release_sock(sk);
 		goto out;
 	}
 
-	list_move(&match->list, &free_list);
+	list_del_rcu(&match->list);
+	spin_unlock_bh(&msk->pm.lock);
 
-	mptcp_pm_remove_addrs(msk, &free_list);
+	mptcp_pm_remove_addr_entry(msk, match);
 
 	release_sock(sk);
 
-	list_for_each_entry_safe(match, entry, &free_list, list) {
-		sock_kfree_s(sk, match, sizeof(*match));
-	}
+	sock_kfree_s(sk, match, sizeof(*match));
 
 	err = 0;
 out:
@@ -330,41 +363,37 @@ out:
 int mptcp_pm_nl_subflow_create_doit(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_pm_addr_entry local = { 0 };
+	struct mptcp_pm_addr_entry entry = { 0 };
 	struct mptcp_addr_info addr_r;
-	struct mptcp_addr_info addr_l;
+	struct mptcp_pm_local local;
 	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");
+	if (!laddr || !raddr) {
+		GENL_SET_ERR_MSG(info, "missing required address(es)");
 		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");
+	msk = mptcp_userspace_pm_get_sock(info);
+	if (!msk)
 		return err;
-	}
 
 	sk = (struct sock *)msk;
 
-	if (!mptcp_pm_is_userspace(msk)) {
-		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
+	err = mptcp_pm_parse_entry(laddr, info, true, &entry);
+	if (err < 0) {
+		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 		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");
+	if (entry.flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
+		GENL_SET_ERR_MSG(info, "invalid addr flags");
+		err = -EINVAL;
 		goto create_err;
 	}
+	entry.flags |= MPTCP_PM_ADDR_FLAG_SUBFLOW;
 
 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
 	if (err < 0) {
@@ -372,28 +401,29 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
 		goto create_err;
 	}
 
-	if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
+	if (!mptcp_pm_addr_families_match(sk, &entry.addr, &addr_r)) {
 		GENL_SET_ERR_MSG(info, "families mismatch");
 		err = -EINVAL;
 		goto create_err;
 	}
 
-	local.addr = addr_l;
-	err = mptcp_userspace_pm_append_new_local_addr(msk, &local, false);
+	err = mptcp_userspace_pm_append_new_local_addr(msk, &entry, false);
 	if (err < 0) {
 		GENL_SET_ERR_MSG(info, "did not match address and id");
 		goto create_err;
 	}
 
-	lock_sock(sk);
-
-	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
+	local.addr = entry.addr;
+	local.flags = entry.flags;
+	local.ifindex = entry.ifindex;
 
+	lock_sock(sk);
+	err = __mptcp_subflow_connect(sk, &local, &addr_r);
 	release_sock(sk);
 
 	spin_lock_bh(&msk->pm.lock);
 	if (err)
-		mptcp_userspace_pm_delete_local_addr(msk, &local);
+		mptcp_userspace_pm_delete_local_addr(msk, &entry);
 	else
 		msk->pm.subflows++;
 	spin_unlock_bh(&msk->pm.lock);
@@ -454,36 +484,25 @@ static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
 int mptcp_pm_nl_subflow_destroy_doit(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_pm_addr_entry 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");
+	if (!laddr || !raddr) {
+		GENL_SET_ERR_MSG(info, "missing required address(es)");
 		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");
+	msk = mptcp_userspace_pm_get_sock(info);
+	if (!msk)
 		return err;
-	}
 
 	sk = (struct sock *)msk;
 
-	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);
+	err = mptcp_pm_parse_entry(laddr, info, true, &addr_l);
 	if (err < 0) {
 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
 		goto destroy_err;
@@ -496,43 +515,41 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info
 	}
 
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
-	if (addr_l.family == AF_INET && ipv6_addr_v4mapped(&addr_r.addr6)) {
-		ipv6_addr_set_v4mapped(addr_l.addr.s_addr, &addr_l.addr6);
-		addr_l.family = AF_INET6;
+	if (addr_l.addr.family == AF_INET && ipv6_addr_v4mapped(&addr_r.addr6)) {
+		ipv6_addr_set_v4mapped(addr_l.addr.addr.s_addr, &addr_l.addr.addr6);
+		addr_l.addr.family = AF_INET6;
 	}
-	if (addr_r.family == AF_INET && ipv6_addr_v4mapped(&addr_l.addr6)) {
+	if (addr_r.family == AF_INET && ipv6_addr_v4mapped(&addr_l.addr.addr6)) {
 		ipv6_addr_set_v4mapped(addr_r.addr.s_addr, &addr_r.addr6);
 		addr_r.family = AF_INET6;
 	}
 #endif
-	if (addr_l.family != addr_r.family) {
+	if (addr_l.addr.family != addr_r.family) {
 		GENL_SET_ERR_MSG(info, "address families do not match");
 		err = -EINVAL;
 		goto destroy_err;
 	}
 
-	if (!addr_l.port || !addr_r.port) {
+	if (!addr_l.addr.port || !addr_r.port) {
 		GENL_SET_ERR_MSG(info, "missing local or remote port");
 		err = -EINVAL;
 		goto destroy_err;
 	}
 
 	lock_sock(sk);
-	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
-	if (ssk) {
-		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
-		struct mptcp_pm_addr_entry entry = { .addr = addr_l };
-
-		spin_lock_bh(&msk->pm.lock);
-		mptcp_userspace_pm_delete_local_addr(msk, &entry);
-		spin_unlock_bh(&msk->pm.lock);
-		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
-		mptcp_close_ssk(sk, ssk, subflow);
-		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
-		err = 0;
-	} else {
+	ssk = mptcp_nl_find_ssk(msk, &addr_l.addr, &addr_r);
+	if (!ssk) {
 		err = -ESRCH;
+		goto release_sock;
 	}
+
+	spin_lock_bh(&msk->pm.lock);
+	mptcp_userspace_pm_delete_local_addr(msk, &addr_l);
+	spin_unlock_bh(&msk->pm.lock);
+	mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
+	mptcp_close_ssk(sk, ssk, mptcp_subflow_ctx(ssk));
+	MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
+release_sock:
 	release_sock(sk);
 
 destroy_err:
@@ -540,35 +557,173 @@ destroy_err:
 	return err;
 }
 
-int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
-				 struct mptcp_pm_addr_entry *loc,
-				 struct mptcp_pm_addr_entry *rem, u8 bkup)
+int mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
 {
+	struct mptcp_pm_addr_entry loc = { .addr = { .family = AF_UNSPEC }, };
+	struct mptcp_pm_addr_entry rem = { .addr = { .family = AF_UNSPEC }, };
+	struct nlattr *attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
+	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
+	struct mptcp_pm_addr_entry *entry;
 	struct mptcp_sock *msk;
 	int ret = -EINVAL;
 	struct sock *sk;
-	u32 token_val;
+	u8 bkup = 0;
 
-	token_val = nla_get_u32(token);
-
-	msk = mptcp_token_get_sock(net, token_val);
+	msk = mptcp_userspace_pm_get_sock(info);
 	if (!msk)
 		return ret;
 
 	sk = (struct sock *)msk;
 
-	if (!mptcp_pm_is_userspace(msk))
+	ret = mptcp_pm_parse_entry(attr, info, false, &loc);
+	if (ret < 0)
 		goto set_flags_err;
 
-	if (loc->addr.family == AF_UNSPEC ||
-	    rem->addr.family == AF_UNSPEC)
+	if (attr_rem) {
+		ret = mptcp_pm_parse_entry(attr_rem, info, false, &rem);
+		if (ret < 0)
+			goto set_flags_err;
+	}
+
+	if (loc.addr.family == AF_UNSPEC ||
+	    rem.addr.family == AF_UNSPEC) {
+		GENL_SET_ERR_MSG(info, "invalid address families");
+		ret = -EINVAL;
 		goto set_flags_err;
+	}
+
+	if (loc.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
+		bkup = 1;
+
+	spin_lock_bh(&msk->pm.lock);
+	entry = mptcp_userspace_pm_lookup_addr(msk, &loc.addr);
+	if (entry) {
+		if (bkup)
+			entry->flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
+		else
+			entry->flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP;
+	}
+	spin_unlock_bh(&msk->pm.lock);
 
 	lock_sock(sk);
-	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
+	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc.addr, &rem.addr, bkup);
 	release_sock(sk);
 
 set_flags_err:
 	sock_put(sk);
 	return ret;
 }
+
+int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
+				 struct netlink_callback *cb)
+{
+	struct id_bitmap {
+		DECLARE_BITMAP(map, MPTCP_PM_MAX_ADDR_ID + 1);
+	} *bitmap;
+	const struct genl_info *info = genl_info_dump(cb);
+	struct mptcp_pm_addr_entry *entry;
+	struct mptcp_sock *msk;
+	int ret = -EINVAL;
+	struct sock *sk;
+	void *hdr;
+
+	bitmap = (struct id_bitmap *)cb->ctx;
+
+	msk = mptcp_userspace_pm_get_sock(info);
+	if (!msk)
+		return ret;
+
+	sk = (struct sock *)msk;
+
+	lock_sock(sk);
+	spin_lock_bh(&msk->pm.lock);
+	mptcp_for_each_userspace_pm_addr(msk, entry) {
+		if (test_bit(entry->addr.id, bitmap->map))
+			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;
+		}
+
+		__set_bit(entry->addr.id, bitmap->map);
+		genlmsg_end(msg, hdr);
+	}
+	spin_unlock_bh(&msk->pm.lock);
+	release_sock(sk);
+	ret = msg->len;
+
+	sock_put(sk);
+	return ret;
+}
+
+int mptcp_userspace_pm_get_addr(struct sk_buff *skb,
+				struct genl_info *info)
+{
+	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
+	struct mptcp_pm_addr_entry addr, *entry;
+	struct mptcp_sock *msk;
+	struct sk_buff *msg;
+	int ret = -EINVAL;
+	struct sock *sk;
+	void *reply;
+
+	msk = mptcp_userspace_pm_get_sock(info);
+	if (!msk)
+		return ret;
+
+	sk = (struct sock *)msk;
+
+	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
+	if (ret < 0)
+		goto out;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	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;
+	}
+
+	lock_sock(sk);
+	spin_lock_bh(&msk->pm.lock);
+	entry = mptcp_userspace_pm_lookup_addr_by_id(msk, 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(&msk->pm.lock);
+	release_sock(sk);
+	sock_put(sk);
+	return ret;
+
+unlock_fail:
+	spin_unlock_bh(&msk->pm.lock);
+	release_sock(sk);
+fail:
+	nlmsg_free(msg);
+out:
+	sock_put(sk);
+	return ret;
+}