From: Geliang Tang <tanggeliang@kylinos.cn>

With the previous commit, we can reuse the send_nlmsg() code in
get_addr() interfaces between the netlink PM and userspace PM.
They only need to implement their own get_addr() interfaces to
hold the different locks, get the entry from the different lists,
then release the locks.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/mptcp/pm_netlink.c   | 58 ++++++++++++++++++++--------------------
 net/mptcp/pm_userspace.c | 32 ----------------------
 2 files changed, 29 insertions(+), 61 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index b646f97f6afe..ef47b54d8328 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1795,21 +1795,7 @@ static int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 {
 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
 	struct mptcp_pm_addr_entry *entry;
-	struct sk_buff *msg;
 	int ret = -EINVAL;
-	void *reply;
-
-	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, id);
@@ -1819,21 +1805,6 @@ static int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 	}
 	spin_unlock_bh(&pernet->lock);
 
-	if (ret) {
-		GENL_SET_ERR_MSG(info, "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;
 }
 
@@ -1849,13 +1820,42 @@ int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
 	struct mptcp_pm_addr_entry addr;
+	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;
+	}
+
 	ret = mptcp_pm_get_addr(addr.addr.id, &addr, info);
+	if (ret) {
+		GENL_SET_ERR_MSG(info, "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;
 }
 
diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 80cb2c6508ba..7c0bb084303b 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -675,10 +675,8 @@ int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 	struct net *net = genl_info_net(info);
 	struct mptcp_pm_addr_entry *entry;
 	struct mptcp_sock *msk;
-	struct sk_buff *msg;
 	int ret = -EINVAL;
 	struct sock *sk;
-	void *reply;
 
 	msk = mptcp_token_get_sock(net, nla_get_u32(token));
 	if (!msk) {
@@ -693,20 +691,6 @@ int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 		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, id);
@@ -717,22 +701,6 @@ int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
 	spin_unlock_bh(&msk->pm.lock);
 	release_sock(sk);
 
-	if (ret) {
-		GENL_SET_ERR_MSG(info, "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);
-	sock_put(sk);
-	return ret;
-
-fail:
-	nlmsg_free(msg);
 out:
 	sock_put(sk);
 	return ret;
-- 
2.43.0