[MPTCP][PATCH v2 mptcp-next 03/10] mptcp: register ipv6 addr notifier

[Geliang Tang <geliangtang@gmail.com>]

This patch registered a ipv6 addr notifier, named mptcp_pm_addr6_notifier,
to deal with the events of net device UP, DOWN and CHANGE, and skip the
loopback device.

Save the ipv6 address, and pass it to the event handler.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 net/mptcp/pm_fullmesh.c | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/net/mptcp/pm_fullmesh.c b/net/mptcp/pm_fullmesh.c
index 38a44ce8a5fa..bac06ddc658b 100644
--- a/net/mptcp/pm_fullmesh.c
+++ b/net/mptcp/pm_fullmesh.c
@@ -3,6 +3,8 @@
 #define pr_fmt(fmt) "MPTCP: " fmt
 
 #include <linux/kernel.h>
+#include <linux/inetdevice.h>
+#include <net/addrconf.h>
 #include <net/mptcp.h>
 
 #include "protocol.h"
@@ -41,8 +43,47 @@ static struct notifier_block mptcp_pm_addr4_notifier = {
 	.notifier_call = mptcp_pm_addr4_event,
 };
 
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+
+static int mptcp_pm_addr6_event(struct notifier_block *this,
+				unsigned long event, void *ptr)
+{
+	const struct inet6_ifaddr *ifa6 = (struct inet6_ifaddr *)ptr;
+	struct net *net = dev_net(ifa6->idev->dev);
+	int addr_type = ipv6_addr_type(&ifa6->addr);
+	struct mptcp_addr_info addr = { 0 };
+
+	if (!(event == NETDEV_UP || event == NETDEV_DOWN || event == NETDEV_CHANGE))
+		goto out;
+
+	if (ifa6->scope > RT_SCOPE_LINK ||
+	    addr_type == IPV6_ADDR_ANY ||
+	    (addr_type & IPV6_ADDR_LOOPBACK) ||
+	    (addr_type & IPV6_ADDR_LINKLOCAL))
+		goto out;
+
+	addr.family = AF_INET6;
+	addr.addr6 = ifa6->addr;
+
+	addr_event_handler(event, net, &addr);
+
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block mptcp_pm_addr6_notifier = {
+	.notifier_call = mptcp_pm_addr6_event,
+};
+
+#endif
+
 void __init mptcp_pm_fm_init(void)
 {
 	if (register_inetaddr_notifier(&mptcp_pm_addr4_notifier))
 		return;
+
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+	if (register_inet6addr_notifier(&mptcp_pm_addr6_notifier))
+		unregister_inetaddr_notifier(&mptcp_pm_addr4_notifier);
+#endif
 }
-- 
2.31.1