[PATCH net-next 3/7] mptcp: add mptcp_userspace_pm_get_sock helper

[Matthieu Baerts (NGI0)]

From: Geliang Tang <tanggeliang@xxxxxxxxxx>

Each userspace pm netlink function uses nla_get_u32() to get the msk
token value, then pass it to mptcp_token_get_sock() to get the msk.
Finally check whether userspace PM is selected on this msk. It makes
sense to wrap them into a helper, named mptcp_userspace_pm_get_sock(),
to do this.

This patch doesn't change the behaviour of the code, just refactoring.

Signed-off-by: Geliang Tang <tanggeliang@xxxxxxxxxx>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
---
 net/mptcp/pm_userspace.c | 144 ++++++++++++++++-------------------------------
 1 file changed, 47 insertions(+), 97 deletions(-)

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 6a27fab238f15b577e1e17225d4450e60ffd25d7..afb04343e74d2340cd77e298489b55340dda0899 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -173,36 +173,50 @@ bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
 	return backup;
 }
 
-int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
+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");
@@ -275,7 +289,6 @@ static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk,
 
 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;
 	struct mptcp_pm_addr_entry *entry;
@@ -283,30 +296,21 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 	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;
@@ -343,7 +347,6 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 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 entry = { 0 };
 	struct mptcp_addr_info addr_r;
@@ -351,28 +354,18 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
 	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");
-		goto create_err;
-	}
-
 	err = mptcp_pm_parse_entry(laddr, info, true, &entry);
 	if (err < 0) {
 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
@@ -475,35 +468,24 @@ 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_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);
 	if (err < 0) {
 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
@@ -566,31 +548,19 @@ 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 *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
-	struct net *net = sock_net(skb->sk);
 	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);
-	if (!msk) {
-		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
+	msk = mptcp_userspace_pm_get_sock(info);
+	if (!msk)
 		return ret;
-	}
 
 	sk = (struct sock *)msk;
 
-	if (!mptcp_pm_is_userspace(msk)) {
-		GENL_SET_ERR_MSG(info, "userspace PM not selected");
-		goto set_flags_err;
-	}
-
 	ret = mptcp_pm_parse_entry(attr, info, false, &loc);
 	if (ret < 0)
 		goto set_flags_err;
@@ -637,30 +607,20 @@ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 		DECLARE_BITMAP(map, MPTCP_PM_MAX_ADDR_ID + 1);
 	} *bitmap;
 	const struct genl_info *info = genl_info_dump(cb);
-	struct net *net = sock_net(msg->sk);
 	struct mptcp_pm_addr_entry *entry;
 	struct mptcp_sock *msk;
-	struct nlattr *token;
 	int ret = -EINVAL;
 	struct sock *sk;
 	void *hdr;
 
 	bitmap = (struct id_bitmap *)cb->ctx;
-	token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 
-	msk = mptcp_token_get_sock(net, nla_get_u32(token));
-	if (!msk) {
-		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
+	msk = mptcp_userspace_pm_get_sock(info);
+	if (!msk)
 		return ret;
-	}
 
 	sk = (struct sock *)msk;
 
-	if (!mptcp_pm_is_userspace(msk)) {
-		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
-		goto out;
-	}
-
 	lock_sock(sk);
 	spin_lock_bh(&msk->pm.lock);
 	mptcp_for_each_userspace_pm_addr(msk, entry) {
@@ -685,7 +645,6 @@ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
 	release_sock(sk);
 	ret = msg->len;
 
-out:
 	sock_put(sk);
 	return ret;
 }
@@ -694,28 +653,19 @@ int mptcp_userspace_pm_get_addr(struct sk_buff *skb,
 				struct genl_info *info)
 {
 	struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
-	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
 	struct mptcp_pm_addr_entry addr, *entry;
-	struct net *net = sock_net(skb->sk);
 	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) {
-		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
+	msk = mptcp_userspace_pm_get_sock(info);
+	if (!msk)
 		return ret;
-	}
 
 	sk = (struct sock *)msk;
 
-	if (!mptcp_pm_is_userspace(msk)) {
-		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
-		goto out;
-	}
-
 	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
 	if (ret < 0)
 		goto out;

-- 
2.45.2