This patch added the fullmesh flag setting support in pm_netlink.

If the fullmesh flag of the address is changed, remove all the related
subflows, update the fullmesh flag and create subflows again.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 net/mptcp/pm_netlink.c | 35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 4c06cd6381ef..8c5a4be21e3d 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1722,9 +1722,19 @@ mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
 	return -EMSGSIZE;
 }
 
-static int mptcp_nl_addr_backup(struct net *net,
-				struct mptcp_addr_info *addr,
-				u8 bkup)
+static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
+				 struct mptcp_addr_info *addr)
+{
+	struct mptcp_rm_list list = { .nr = 0 };
+
+	list.ids[list.nr++] = addr->id;
+
+	mptcp_pm_nl_rm_subflow_received(msk, &list);
+	mptcp_pm_create_subflow_or_signal_addr(msk);
+}
+
+static int mptcp_nl_set_flags(struct net *net,
+			      struct mptcp_pm_addr_entry *entry)
 {
 	long s_slot = 0, s_num = 0;
 	struct mptcp_sock *msk;
@@ -1738,7 +1748,10 @@ static int mptcp_nl_addr_backup(struct net *net,
 
 		lock_sock(sk);
 		spin_lock_bh(&msk->pm.lock);
-		ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
+		ret = mptcp_pm_nl_mp_prio_send_ack(msk, &entry->addr,
+						   entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
+		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
+			mptcp_pm_nl_fullmesh(msk, &entry->addr);
 		spin_unlock_bh(&msk->pm.lock);
 		release_sock(sk);
 
@@ -1756,15 +1769,13 @@ static int mptcp_nl_cmd_set_flags(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 net *net = sock_net(skb->sk);
-	u8 bkup = 0, lookup_by_id = 0;
+	u8 lookup_by_id = 0;
 	int ret;
 
 	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
 	if (ret < 0)
 		return ret;
 
-	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
-		bkup = 1;
 	if (addr.addr.family == AF_UNSPEC) {
 		lookup_by_id = 1;
 		if (!addr.addr.id)
@@ -1778,14 +1789,20 @@ static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 	}
 
-	if (bkup)
+	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
 		entry->flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
 	else
 		entry->flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP;
+
+	if (addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH)
+		entry->flags |= MPTCP_PM_ADDR_FLAG_FULLMESH;
+	else
+		entry->flags &= ~MPTCP_PM_ADDR_FLAG_FULLMESH;
+
 	addr = *entry;
 	spin_unlock_bh(&pernet->lock);
 
-	mptcp_nl_addr_backup(net, &addr.addr, bkup);
+	mptcp_nl_set_flags(net, &addr);
 	return 0;
 }
 
-- 
2.31.1

On Wed, 12 Jan 2022, Geliang Tang wrote:

> This patch added the fullmesh flag setting support in pm_netlink.
>
> If the fullmesh flag of the address is changed, remove all the related
> subflows, update the fullmesh flag and create subflows again.
>
> Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> ---
> net/mptcp/pm_netlink.c | 35 ++++++++++++++++++++++++++---------
> 1 file changed, 26 insertions(+), 9 deletions(-)
>
> diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
> index 4c06cd6381ef..8c5a4be21e3d 100644
> --- a/net/mptcp/pm_netlink.c
> +++ b/net/mptcp/pm_netlink.c
> @@ -1722,9 +1722,19 @@ mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
> 	return -EMSGSIZE;
> }
>
> -static int mptcp_nl_addr_backup(struct net *net,
> -				struct mptcp_addr_info *addr,
> -				u8 bkup)
> +static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
> +				 struct mptcp_addr_info *addr)
> +{
> +	struct mptcp_rm_list list = { .nr = 0 };
> +
> +	list.ids[list.nr++] = addr->id;
> +
> +	mptcp_pm_nl_rm_subflow_received(msk, &list);
> +	mptcp_pm_create_subflow_or_signal_addr(msk);
> +}
> +
> +static int mptcp_nl_set_flags(struct net *net,
> +			      struct mptcp_pm_addr_entry *entry)
> {
> 	long s_slot = 0, s_num = 0;
> 	struct mptcp_sock *msk;
> @@ -1738,7 +1748,10 @@ static int mptcp_nl_addr_backup(struct net *net,
>
> 		lock_sock(sk);
> 		spin_lock_bh(&msk->pm.lock);
> -		ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
> +		ret = mptcp_pm_nl_mp_prio_send_ack(msk, &entry->addr,
> +						   entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
> +		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
> +			mptcp_pm_nl_fullmesh(msk, &entry->addr);

My concern here is that if MPTCP_PM_ADDR_FLAG_SIGNAL is not set for 
this entry, mptcp_pm_nl_fullmesh() gets called every time there's a 
MPTCP_PM_CMD_SET_FLAGS command for a valid endpoint.

Would it be better to pass a mask of *changed* flags to 
mptcp_nl_set_flags() so every change to a backup flag doesn't trigger a 
bunch of fullmesh processing, and vice-versa?

- Mat

> 		spin_unlock_bh(&msk->pm.lock);
> 		release_sock(sk);
>
> @@ -1756,15 +1769,13 @@ static int mptcp_nl_cmd_set_flags(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 net *net = sock_net(skb->sk);
> -	u8 bkup = 0, lookup_by_id = 0;
> +	u8 lookup_by_id = 0;
> 	int ret;
>
> 	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
> 	if (ret < 0)
> 		return ret;
>
> -	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
> -		bkup = 1;
> 	if (addr.addr.family == AF_UNSPEC) {
> 		lookup_by_id = 1;
> 		if (!addr.addr.id)
> @@ -1778,14 +1789,20 @@ static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
> 		return -EINVAL;
> 	}
>
> -	if (bkup)
> +	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
> 		entry->flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
> 	else
> 		entry->flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP;
> +
> +	if (addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH)
> +		entry->flags |= MPTCP_PM_ADDR_FLAG_FULLMESH;
> +	else
> +		entry->flags &= ~MPTCP_PM_ADDR_FLAG_FULLMESH;
> +
> 	addr = *entry;
> 	spin_unlock_bh(&pernet->lock);
>
> -	mptcp_nl_addr_backup(net, &addr.addr, bkup);
> +	mptcp_nl_set_flags(net, &addr);
> 	return 0;
> }
>
> -- 
> 2.31.1
>
>
>

--
Mat Martineau
Intel