4 files changed, 222 insertions, 210 deletions

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 16c336c51940..b1f36dc1a091 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -10,6 +10,7 @@
 #include "protocol.h"
 
 #include "mib.h"
+#include "mptcp_pm_gen.h"
 
 /* path manager command handlers */
 
@@ -433,14 +434,62 @@ bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
 	return mptcp_pm_nl_is_backup(msk, &skc_local);
 }
 
-int mptcp_pm_get_addr(struct sk_buff *skb, struct genl_info *info)
+static int mptcp_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
+			     struct genl_info *info)
 {
 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
-		return mptcp_userspace_pm_get_addr(skb, info);
-	return mptcp_pm_nl_get_addr(skb, info);
+		return mptcp_userspace_pm_get_addr(id, addr, info);
+	return mptcp_pm_nl_get_addr(id, addr, info);
 }
 
-int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb)
+int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct mptcp_pm_addr_entry addr;
+	struct nlattr *attr;
+	struct sk_buff *msg;
+	void *reply;
+	int ret;
+
+	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ENDPOINT_ADDR))
+		return -EINVAL;
+
+	attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
+	ret = mptcp_pm_parse_entry(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;
+	}
+
+	ret = mptcp_pm_get_addr(addr.addr.id, &addr, info);
+	if (ret) {
+		NL_SET_ERR_MSG_ATTR(info->extack, attr, "address not found");
+		goto fail;
+	}
+
+	ret = mptcp_nl_fill_addr(msg, &addr);
+	if (ret)
+		goto fail;
+
+	genlmsg_end(msg, reply);
+	ret = genlmsg_reply(msg, info);
+	return ret;
+
+fail:
+	nlmsg_free(msg);
+	return ret;
+}
+
+static int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb)
 {
 	const struct genl_info *info = genl_info_dump(cb);
 
@@ -449,11 +498,34 @@ int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb)
 	return mptcp_pm_nl_dump_addr(msg, cb);
 }
 
-int mptcp_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
+int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg,
+				struct netlink_callback *cb)
+{
+	return mptcp_pm_dump_addr(msg, cb);
+}
+
+static int mptcp_pm_set_flags(struct genl_info *info)
 {
+	struct mptcp_pm_addr_entry loc = { .addr = { .family = AF_UNSPEC }, };
+	struct nlattr *attr_loc;
+	int ret = -EINVAL;
+
+	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_ADDR))
+		return ret;
+
+	attr_loc = info->attrs[MPTCP_PM_ATTR_ADDR];
+	ret = mptcp_pm_parse_entry(attr_loc, info, false, &loc);
+	if (ret < 0)
+		return ret;
+
 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
-		return mptcp_userspace_pm_set_flags(skb, info);
-	return mptcp_pm_nl_set_flags(skb, info);
+		return mptcp_userspace_pm_set_flags(&loc, info);
+	return mptcp_pm_nl_set_flags(&loc, info);
+}
+
+int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	return mptcp_pm_set_flags(info);
 }
 
 void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 572d160edca3..99705a9c2238 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1393,28 +1393,35 @@ static bool mptcp_pm_has_addr_attr_id(const struct nlattr *attr,
 
 int mptcp_pm_nl_add_addr_doit(struct sk_buff *skb, struct genl_info *info)
 {
-	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
 	struct mptcp_pm_addr_entry addr, *entry;
+	struct nlattr *attr;
 	int ret;
 
+	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ENDPOINT_ADDR))
+		return -EINVAL;
+
+	attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
 	ret = mptcp_pm_parse_entry(attr, info, true, &addr);
 	if (ret < 0)
 		return ret;
 
 	if (addr.addr.port && !address_use_port(&addr)) {
-		GENL_SET_ERR_MSG(info, "flags must have signal and not subflow when using port");
+		NL_SET_ERR_MSG_ATTR(info->extack, attr,
+				    "flags must have signal and not subflow when using port");
 		return -EINVAL;
 	}
 
 	if (addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL &&
 	    addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) {
-		GENL_SET_ERR_MSG(info, "flags mustn't have both signal and fullmesh");
+		NL_SET_ERR_MSG_ATTR(info->extack, attr,
+				    "flags mustn't have both signal and fullmesh");
 		return -EINVAL;
 	}
 
 	if (addr.flags & MPTCP_PM_ADDR_FLAG_IMPLICIT) {
-		GENL_SET_ERR_MSG(info, "can't create IMPLICIT endpoint");
+		NL_SET_ERR_MSG_ATTR(info->extack, attr,
+				    "can't create IMPLICIT endpoint");
 		return -EINVAL;
 	}
 
@@ -1587,12 +1594,16 @@ next:
 
 int mptcp_pm_nl_del_addr_doit(struct sk_buff *skb, struct genl_info *info)
 {
-	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
 	struct mptcp_pm_addr_entry addr, *entry;
 	unsigned int addr_max;
+	struct nlattr *attr;
 	int ret;
 
+	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ENDPOINT_ADDR))
+		return -EINVAL;
+
+	attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
 	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
 	if (ret < 0)
 		return ret;
@@ -1608,7 +1619,7 @@ int mptcp_pm_nl_del_addr_doit(struct sk_buff *skb, struct genl_info *info)
 	spin_lock_bh(&pernet->lock);
 	entry = __lookup_addr_by_id(pernet, addr.addr.id);
 	if (!entry) {
-		GENL_SET_ERR_MSG(info, "address not found");
+		NL_SET_ERR_MSG_ATTR(info->extack, attr, "address not found");
 		spin_unlock_bh(&pernet->lock);
 		return -EINVAL;
 	}
@@ -1762,61 +1773,24 @@ nla_put_failure:
 	return -EMSGSIZE;
 }
 
-int mptcp_pm_nl_get_addr(struct sk_buff *skb, struct genl_info *info)
+int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
+			 struct genl_info *info)
 {
-	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_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_entry(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;
-	}
+	struct mptcp_pm_addr_entry *entry;
+	int ret = -EINVAL;
 
 	rcu_read_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;
+	entry = __lookup_addr_by_id(pernet, id);
+	if (entry) {
+		*addr = *entry;
+		ret = 0;
 	}
-
-	ret = mptcp_nl_fill_addr(msg, entry);
-	if (ret)
-		goto unlock_fail;
-
-	genlmsg_end(msg, reply);
-	ret = genlmsg_reply(msg, info);
-	rcu_read_unlock();
-	return ret;
-
-unlock_fail:
 	rcu_read_unlock();
 
-fail:
-	nlmsg_free(msg);
 	return ret;
 }
 
-int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
-{
-	return mptcp_pm_get_addr(skb, info);
-}
-
 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 			  struct netlink_callback *cb)
 {
@@ -1860,12 +1834,6 @@ int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 	return msg->len;
 }
 
-int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg,
-				struct netlink_callback *cb)
-{
-	return mptcp_pm_dump_addr(msg, cb);
-}
-
 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
 {
 	struct nlattr *attr = info->attrs[id];
@@ -1875,7 +1843,9 @@ static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
 
 	*limit = nla_get_u32(attr);
 	if (*limit > MPTCP_PM_ADDR_MAX) {
-		GENL_SET_ERR_MSG(info, "limit greater than maximum");
+		NL_SET_ERR_MSG_ATTR_FMT(info->extack, attr,
+					"limit greater than maximum (%u)",
+					MPTCP_PM_ADDR_MAX);
 		return -EINVAL;
 	}
 	return 0;
@@ -1981,66 +1951,57 @@ next:
 	return ret;
 }
 
-int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info)
+int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,
+			  struct genl_info *info)
 {
-	struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, };
 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
 	u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
 			   MPTCP_PM_ADDR_FLAG_FULLMESH;
-	struct net *net = sock_net(skb->sk);
+	struct net *net = genl_info_net(info);
 	struct mptcp_pm_addr_entry *entry;
 	struct pm_nl_pernet *pernet;
 	u8 lookup_by_id = 0;
 	u8 bkup = 0;
-	int ret;
 
 	pernet = pm_nl_get_pernet(net);
 
-	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
-	if (ret < 0)
-		return ret;
-
-	if (addr.addr.family == AF_UNSPEC) {
+	if (local->addr.family == AF_UNSPEC) {
 		lookup_by_id = 1;
-		if (!addr.addr.id) {
-			GENL_SET_ERR_MSG(info, "missing required inputs");
+		if (!local->addr.id) {
+			NL_SET_ERR_MSG_ATTR(info->extack, attr,
+					    "missing address ID");
 			return -EOPNOTSUPP;
 		}
 	}
 
-	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
+	if (local->flags & MPTCP_PM_ADDR_FLAG_BACKUP)
 		bkup = 1;
 
 	spin_lock_bh(&pernet->lock);
-	entry = lookup_by_id ? __lookup_addr_by_id(pernet, addr.addr.id) :
-			       __lookup_addr(pernet, &addr.addr);
+	entry = lookup_by_id ? __lookup_addr_by_id(pernet, local->addr.id) :
+			       __lookup_addr(pernet, &local->addr);
 	if (!entry) {
 		spin_unlock_bh(&pernet->lock);
-		GENL_SET_ERR_MSG(info, "address not found");
+		NL_SET_ERR_MSG_ATTR(info->extack, attr, "address not found");
 		return -EINVAL;
 	}
-	if ((addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
+	if ((local->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
 	    (entry->flags & (MPTCP_PM_ADDR_FLAG_SIGNAL |
 			     MPTCP_PM_ADDR_FLAG_IMPLICIT))) {
 		spin_unlock_bh(&pernet->lock);
-		GENL_SET_ERR_MSG(info, "invalid addr flags");
+		NL_SET_ERR_MSG_ATTR(info->extack, attr, "invalid addr flags");
 		return -EINVAL;
 	}
 
-	changed = (addr.flags ^ entry->flags) & mask;
-	entry->flags = (entry->flags & ~mask) | (addr.flags & mask);
-	addr = *entry;
+	changed = (local->flags ^ entry->flags) & mask;
+	entry->flags = (entry->flags & ~mask) | (local->flags & mask);
+	*local = *entry;
 	spin_unlock_bh(&pernet->lock);
 
-	mptcp_nl_set_flags(net, &addr.addr, bkup, changed);
+	mptcp_nl_set_flags(net, &local->addr, bkup, changed);
 	return 0;
 }
 
-int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info)
-{
-	return mptcp_pm_set_flags(skb, info);
-}
-
 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
 {
 	genlmsg_multicast_netns(&mptcp_genl_family, net,
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index a3d477059b11..277cf092a870 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -175,14 +175,13 @@ bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
 
 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;
+	struct nlattr *token;
 
-	if (!token) {
-		GENL_SET_ERR_MSG(info, "missing required token");
+	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_TOKEN))
 		return NULL;
-	}
 
+	token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 	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");
@@ -190,7 +189,8 @@ static struct mptcp_sock *mptcp_userspace_pm_get_sock(const struct genl_info *in
 	}
 
 	if (!mptcp_pm_is_userspace(msk)) {
-		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
+		NL_SET_ERR_MSG_ATTR(info->extack, token,
+				    "userspace PM not selected");
 		sock_put((struct sock *)msk);
 		return NULL;
 	}
@@ -200,16 +200,14 @@ static struct mptcp_sock *mptcp_userspace_pm_get_sock(const struct genl_info *in
 
 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;
+	struct nlattr *addr;
 	int err = -EINVAL;
 	struct sock *sk;
 
-	if (!addr) {
-		GENL_SET_ERR_MSG(info, "missing required address");
+	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_ADDR))
 		return err;
-	}
 
 	msk = mptcp_userspace_pm_get_sock(info);
 	if (!msk)
@@ -217,21 +215,27 @@ int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
 
 	sk = (struct sock *)msk;
 
+	addr = info->attrs[MPTCP_PM_ATTR_ADDR];
 	err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
-	if (err < 0) {
-		GENL_SET_ERR_MSG(info, "error parsing local address");
+	if (err < 0)
+		goto announce_err;
+
+	if (addr_val.addr.id == 0) {
+		NL_SET_ERR_MSG_ATTR(info->extack, addr, "invalid addr id");
+		err = -EINVAL;
 		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");
+	if (!(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
+		NL_SET_ERR_MSG_ATTR(info->extack, addr, "invalid addr flags");
 		err = -EINVAL;
 		goto announce_err;
 	}
 
 	err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val, false);
 	if (err < 0) {
-		GENL_SET_ERR_MSG(info, "did not match address and id");
+		NL_SET_ERR_MSG_ATTR(info->extack, addr,
+				    "did not match address and id");
 		goto announce_err;
 	}
 
@@ -253,8 +257,7 @@ int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
-static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk,
-						     struct genl_info *info)
+static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk)
 {
 	struct mptcp_rm_list list = { .nr = 0 };
 	struct mptcp_subflow_context *subflow;
@@ -269,10 +272,8 @@ static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk,
 			break;
 		}
 	}
-	if (!has_id_0) {
-		GENL_SET_ERR_MSG(info, "address with id 0 not found");
+	if (!has_id_0)
 		goto remove_err;
-	}
 
 	list.ids[list.nr++] = 0;
 
@@ -309,18 +310,17 @@ void mptcp_pm_remove_addr_entry(struct mptcp_sock *msk,
 
 int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 {
-	struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
 	struct mptcp_pm_addr_entry *match;
 	struct mptcp_sock *msk;
+	struct nlattr *id;
 	int err = -EINVAL;
 	struct sock *sk;
 	u8 id_val;
 
-	if (!id) {
-		GENL_SET_ERR_MSG(info, "missing required ID");
+	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_LOC_ID))
 		return err;
-	}
 
+	id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
 	id_val = nla_get_u8(id);
 
 	msk = mptcp_userspace_pm_get_sock(info);
@@ -330,7 +330,7 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 	sk = (struct sock *)msk;
 
 	if (id_val == 0) {
-		err = mptcp_userspace_pm_remove_id_zero_address(msk, info);
+		err = mptcp_userspace_pm_remove_id_zero_address(msk);
 		goto out;
 	}
 
@@ -339,7 +339,6 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 	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;
@@ -356,25 +355,28 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 
 	err = 0;
 out:
+	if (err)
+		NL_SET_ERR_MSG_ATTR_FMT(info->extack, id,
+					"address with id %u not found",
+					id_val);
+
 	sock_put(sk);
 	return err;
 }
 
 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 *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 	struct mptcp_pm_addr_entry entry = { 0 };
 	struct mptcp_addr_info addr_r;
+	struct nlattr *raddr, *laddr;
 	struct mptcp_pm_local local;
 	struct mptcp_sock *msk;
 	int err = -EINVAL;
 	struct sock *sk;
 
-	if (!laddr || !raddr) {
-		GENL_SET_ERR_MSG(info, "missing required address(es)");
+	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_ADDR) ||
+	    GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_ADDR_REMOTE))
 		return err;
-	}
 
 	msk = mptcp_userspace_pm_get_sock(info);
 	if (!msk)
@@ -382,24 +384,22 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
 
 	sk = (struct sock *)msk;
 
+	laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 	err = mptcp_pm_parse_entry(laddr, info, true, &entry);
-	if (err < 0) {
-		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
+	if (err < 0)
 		goto create_err;
-	}
 
 	if (entry.flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
-		GENL_SET_ERR_MSG(info, "invalid addr flags");
+		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "invalid addr flags");
 		err = -EINVAL;
 		goto create_err;
 	}
 	entry.flags |= MPTCP_PM_ADDR_FLAG_SUBFLOW;
 
+	raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
-	if (err < 0) {
-		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
+	if (err < 0)
 		goto create_err;
-	}
 
 	if (!mptcp_pm_addr_families_match(sk, &entry.addr, &addr_r)) {
 		GENL_SET_ERR_MSG(info, "families mismatch");
@@ -409,7 +409,8 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
 
 	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");
+		NL_SET_ERR_MSG_ATTR(info->extack, laddr,
+				    "did not match address and id");
 		goto create_err;
 	}
 
@@ -421,6 +422,9 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
 	err = __mptcp_subflow_connect(sk, &local, &addr_r);
 	release_sock(sk);
 
+	if (err)
+		GENL_SET_ERR_MSG_FMT(info, "connect error: %d", err);
+
 	spin_lock_bh(&msk->pm.lock);
 	if (err)
 		mptcp_userspace_pm_delete_local_addr(msk, &entry);
@@ -483,18 +487,16 @@ 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 *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 	struct mptcp_pm_addr_entry addr_l;
 	struct mptcp_addr_info addr_r;
+	struct nlattr *raddr, *laddr;
 	struct mptcp_sock *msk;
 	struct sock *sk, *ssk;
 	int err = -EINVAL;
 
-	if (!laddr || !raddr) {
-		GENL_SET_ERR_MSG(info, "missing required address(es)");
+	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_ADDR) ||
+	    GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_ADDR_REMOTE))
 		return err;
-	}
 
 	msk = mptcp_userspace_pm_get_sock(info);
 	if (!msk)
@@ -502,17 +504,15 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info
 
 	sk = (struct sock *)msk;
 
+	laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
 	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");
+	if (err < 0)
 		goto destroy_err;
-	}
 
+	raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
-	if (err < 0) {
-		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
+	if (err < 0)
 		goto destroy_err;
-	}
 
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 	if (addr_l.addr.family == AF_INET && ipv6_addr_v4mapped(&addr_r.addr6)) {
@@ -530,8 +530,14 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info
 		goto destroy_err;
 	}
 
-	if (!addr_l.addr.port || !addr_r.port) {
-		GENL_SET_ERR_MSG(info, "missing local or remote port");
+	if (!addr_l.addr.port) {
+		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "missing local port");
+		err = -EINVAL;
+		goto destroy_err;
+	}
+
+	if (!addr_r.port) {
+		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "missing remote port");
 		err = -EINVAL;
 		goto destroy_err;
 	}
@@ -539,6 +545,7 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info
 	lock_sock(sk);
 	ssk = mptcp_nl_find_ssk(msk, &addr_l.addr, &addr_r);
 	if (!ssk) {
+		GENL_SET_ERR_MSG(info, "subflow not found");
 		err = -ESRCH;
 		goto release_sock;
 	}
@@ -557,46 +564,51 @@ destroy_err:
 	return err;
 }
 
-int mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
+int mptcp_userspace_pm_set_flags(struct mptcp_pm_addr_entry *local,
+				 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_addr_info rem = { .family = AF_UNSPEC, };
 	struct mptcp_pm_addr_entry *entry;
+	struct nlattr *attr, *attr_rem;
 	struct mptcp_sock *msk;
 	int ret = -EINVAL;
 	struct sock *sk;
 	u8 bkup = 0;
 
+	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_ADDR_REMOTE))
+		return ret;
+
 	msk = mptcp_userspace_pm_get_sock(info);
 	if (!msk)
 		return ret;
 
 	sk = (struct sock *)msk;
 
-	ret = mptcp_pm_parse_entry(attr, info, false, &loc);
-	if (ret < 0)
+	attr = info->attrs[MPTCP_PM_ATTR_ADDR];
+	if (local->addr.family == AF_UNSPEC) {
+		NL_SET_ERR_MSG_ATTR(info->extack, attr,
+				    "invalid local address family");
+		ret = -EINVAL;
 		goto set_flags_err;
-
-	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");
+	attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
+	ret = mptcp_pm_parse_addr(attr_rem, info, &rem);
+	if (ret < 0)
+		goto set_flags_err;
+
+	if (rem.family == AF_UNSPEC) {
+		NL_SET_ERR_MSG_ATTR(info->extack, attr_rem,
+				    "invalid remote address family");
 		ret = -EINVAL;
 		goto set_flags_err;
 	}
 
-	if (loc.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
+	if (local->flags & MPTCP_PM_ADDR_FLAG_BACKUP)
 		bkup = 1;
 
 	spin_lock_bh(&msk->pm.lock);
-	entry = mptcp_userspace_pm_lookup_addr(msk, &loc.addr);
+	entry = mptcp_userspace_pm_lookup_addr(msk, &local->addr);
 	if (entry) {
 		if (bkup)
 			entry->flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
@@ -606,9 +618,13 @@ int mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
 	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, &local->addr, &rem, bkup);
 	release_sock(sk);
 
+	/* mptcp_pm_nl_mp_prio_send_ack() only fails in one case */
+	if (ret < 0)
+		GENL_SET_ERR_MSG(info, "subflow not found");
+
 set_flags_err:
 	sock_put(sk);
 	return ret;
@@ -663,16 +679,13 @@ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 	return ret;
 }
 
-int mptcp_userspace_pm_get_addr(struct sk_buff *skb,
+int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 				struct genl_info *info)
 {
-	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
-	struct mptcp_pm_addr_entry addr, *entry;
+	struct mptcp_pm_addr_entry *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)
@@ -680,50 +693,16 @@ int mptcp_userspace_pm_get_addr(struct sk_buff *skb,
 
 	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;
+	entry = mptcp_userspace_pm_lookup_addr_by_id(msk, id);
+	if (entry) {
+		*addr = *entry;
+		ret = 0;
 	}
-
-	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;
 }
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index f6a207958459..37226cdd9e37 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1038,9 +1038,10 @@ bool mptcp_lookup_subflow_by_saddr(const struct list_head *list,
 				   const struct mptcp_addr_info *saddr);
 bool mptcp_remove_anno_list_by_saddr(struct mptcp_sock *msk,
 				     const struct mptcp_addr_info *addr);
-int mptcp_pm_set_flags(struct sk_buff *skb, struct genl_info *info);
-int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info);
-int mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info);
+int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,
+			  struct genl_info *info);
+int mptcp_userspace_pm_set_flags(struct mptcp_pm_addr_entry *local,
+				 struct genl_info *info);
 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
 			   const struct mptcp_addr_info *addr,
 			   bool echo);
@@ -1131,14 +1132,13 @@ int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_in
 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
 bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
 bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
-int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb);
 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
 			  struct netlink_callback *cb);
 int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 				 struct netlink_callback *cb);
-int mptcp_pm_get_addr(struct sk_buff *skb, struct genl_info *info);
-int mptcp_pm_nl_get_addr(struct sk_buff *skb, struct genl_info *info);
-int mptcp_userspace_pm_get_addr(struct sk_buff *skb,
+int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
+			 struct genl_info *info);
+int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 				struct genl_info *info);
 
 static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *subflow)