kernel_v5.patch

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 5b896a9..c80379e 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1421,6 +1421,12 @@ accept_ra_defrtr - BOOLEAN
 	Functional default: enabled if accept_ra is enabled.
 			    disabled if accept_ra is disabled.

+accept_ra_defrtr_metric - INTEGER
+    Metric for default router learned in Router Advertisement.
+
+    Functional default: 0 if accept_ra_defrtr is enabled.
+                        -1 if accept_ra_defrtr is disabled.
+
 accept_ra_from_local - BOOLEAN
 	Accept RA with source-address that is found on local machine
         if the RA is otherwise proper and able to be accepted.
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index b9dfca5..6c9afff 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -30,6 +30,7 @@ struct ipv6_devconf {
 	__s32		max_desync_factor;
 	__s32		max_addresses;
 	__s32		accept_ra_defrtr;
+	__s32		accept_ra_defrtr_metric;
 	__s32		accept_ra_min_hop_limit;
 	__s32		accept_ra_pinfo;
 	__s32		ignore_routes_with_linkdown;
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 2c43993..2660688 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -134,7 +134,8 @@ struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr,
 				     struct net_device *dev);
 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
-				     struct net_device *dev, unsigned int pref);
+				     struct net_device *dev, unsigned int pref,
+				     unsigned int defrtr_usr_metric);

 void rt6_purge_dflt_routers(struct net *net);

diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h
index 8c27723..3de856e 100644
--- a/include/uapi/linux/ipv6.h
+++ b/include/uapi/linux/ipv6.h
@@ -178,6 +178,7 @@ enum {
 	DEVCONF_DROP_UNSOLICITED_NA,
 	DEVCONF_KEEP_ADDR_ON_DOWN,
 	DEVCONF_RTR_SOLICIT_MAX_INTERVAL,
+ 	DEVCONF_ACCEPT_RA_DEFRTR_METRIC,
 	DEVCONF_MAX
 };

diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
index d2b1215..74df055 100644
--- a/include/uapi/linux/sysctl.h
+++ b/include/uapi/linux/sysctl.h
@@ -568,6 +568,7 @@ enum {
 	NET_IPV6_PROXY_NDP=23,
 	NET_IPV6_ACCEPT_SOURCE_ROUTE=25,
 	NET_IPV6_ACCEPT_RA_FROM_LOCAL=26,
+ 	NET_IPV6_ACCEPT_RA_DEFRTR_METRIC=27,
 	__NET_IPV6_MAX
 };

diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 6eb99c1..4809a21 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -524,6 +524,7 @@ static const struct bin_table bin_net_ipv6_conf_var_table[] = {
 	{ CTL_INT,	NET_IPV6_PROXY_NDP,			"proxy_ndp" },
 	{ CTL_INT,	NET_IPV6_ACCEPT_SOURCE_ROUTE,		"accept_source_route" },
 	{ CTL_INT,	NET_IPV6_ACCEPT_RA_FROM_LOCAL,		"accept_ra_from_local" },
+ 	{ CTL_INT,  NET_IPV6_ACCEPT_RA_DEFRTR_METRIC,   "accept_ra_defrtr_metric" },
 	{}
 };

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 4ce7f91..9bf9299 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -216,6 +216,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
 	.max_desync_factor	= MAX_DESYNC_FACTOR,
 	.max_addresses		= IPV6_MAX_ADDRESSES,
 	.accept_ra_defrtr	= 1,
+	.accept_ra_defrtr_metric = 0,
 	.accept_ra_from_local	= 0,
 	.accept_ra_min_hop_limit= 1,
 	.accept_ra_pinfo	= 1,
@@ -262,6 +263,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
 	.max_desync_factor	= MAX_DESYNC_FACTOR,
 	.max_addresses		= IPV6_MAX_ADDRESSES,
 	.accept_ra_defrtr	= 1,
+	.accept_ra_defrtr_metric = 0,
 	.accept_ra_from_local	= 0,
 	.accept_ra_min_hop_limit= 1,
 	.accept_ra_pinfo	= 1,
@@ -4983,6 +4985,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
 	array[DEVCONF_DROP_UNICAST_IN_L2_MULTICAST] = cnf->drop_unicast_in_l2_multicast;
 	array[DEVCONF_DROP_UNSOLICITED_NA] = cnf->drop_unsolicited_na;
 	array[DEVCONF_KEEP_ADDR_ON_DOWN] = cnf->keep_addr_on_down;
+	array[DEVCONF_ACCEPT_RA_DEFRTR_METRIC] = cnf->accept_ra_defrtr_metric;
 }

 static inline size_t inet6_ifla6_size(void)
@@ -5902,6 +5905,13 @@ static const struct ctl_table addrconf_sysctl[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+	{
+		.procname	= "accept_ra_defrtr_metric",
+		.data		= &ipv6_devconf.accept_ra_defrtr_metric,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
 	{
 		.procname	= "accept_ra_min_hop_limit",
 		.data		= &ipv6_devconf.accept_ra_min_hop_limit,
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 505d048..5d736ec 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1126,6 +1126,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 	unsigned int pref = 0;
 	__u32 old_if_flags;
 	bool send_ifinfo_notify = false;
+ 	unsigned int defrtr_usr_metric = 0;

 	__u8 *opt = (__u8 *)(ra_msg + 1);

@@ -1248,17 +1249,22 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 			return;
 		}
 	}
-	if (rt && lifetime == 0) {
+	defrtr_usr_metric = in6_dev->cnf.accept_ra_defrtr_metric;
+	if (defrtr_usr_metric == 0)
+		defrtr_usr_metric = IP6_RT_PRIO_USER;
+	/* delete the route if lifetime is 0 or if metric needs change. */
+	if (rt && ((lifetime == 0) || (rt->rt6i_metric != defrtr_usr_metric))) {
 		ip6_del_rt(rt);
 		rt = NULL;
 	}

-	ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, for dev: %s\n",
-		  rt, lifetime, skb->dev->name);
+	ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, metric: %d, for dev: %s\n",
+		  rt, lifetime, defrtr_usr_metric, skb->dev->name);
 	if (!rt && lifetime) {
 		ND_PRINTK(3, info, "RA: adding default router\n");

-		rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
+		rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev,
+			pref, defrtr_usr_metric);
 		if (!rt) {
 			ND_PRINTK(0, err,
 				  "RA: %s failed to add default route\n",
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 27c93ba..a296a39 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2440,11 +2440,11 @@ struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_dev

 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
 				     struct net_device *dev,
-				     unsigned int pref)
+				     unsigned int pref,
+				     unsigned int defrtr_usr_metric)
 {
 	struct fib6_config cfg = {
 		.fc_table	= l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
-		.fc_metric	= IP6_RT_PRIO_USER,
+		.fc_metric	= defrtr_usr_metric ? defrtr_usr_metric : IP6_RT_PRIO_USER,
 		.fc_ifindex	= dev->ifindex,
 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
 				  RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
@@ -2453,6 +2453,9 @@ struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
 		.fc_nlinfo.nl_net = dev_net(dev),
 	};

+ 	ND_PRINTK(3, info, "RA: metric: %d for dev: %s\n",
+  	 	cfg.fc_metric, dev->name);
+
 	cfg.fc_gateway = *gwaddr;

 	if (!ip6_route_add(&cfg)) {