Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 673a4a9..53caf59 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *	Neighbour Discovery for IPv6
  *	Linux INET6 implementation
@@ -5,11 +6,6 @@
  *	Authors:
  *	Pedro Roque		<roque@di.fc.ul.pt>
  *	Mike Shaver		<shaver@ingenia.com>
- *
- *	This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
  */
 
 /*
@@ -77,6 +73,8 @@
 		      const struct net_device *dev,
 		      __u32 *hash_rnd);
 static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
+static bool ndisc_allow_add(const struct net_device *dev,
+			    struct netlink_ext_ack *extack);
 static int ndisc_constructor(struct neighbour *neigh);
 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
@@ -117,6 +115,7 @@
 	.pconstructor =	pndisc_constructor,
 	.pdestructor =	pndisc_destructor,
 	.proxy_redo =	pndisc_redo,
+	.allow_add  =   ndisc_allow_add,
 	.id =		"ndisc_cache",
 	.parms = {
 		.tbl			= &nd_tbl,
@@ -197,6 +196,7 @@
 {
 	return opt->nd_opt_type == ND_OPT_RDNSS ||
 		opt->nd_opt_type == ND_OPT_DNSSL ||
+		opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
 		ndisc_ops_is_useropt(dev, opt->nd_opt_type);
 }
 
@@ -392,6 +392,20 @@
 	ipv6_dev_mc_dec(dev, &maddr);
 }
 
+/* called with rtnl held */
+static bool ndisc_allow_add(const struct net_device *dev,
+			    struct netlink_ext_ack *extack)
+{
+	struct inet6_dev *idev = __in6_dev_get(dev);
+
+	if (!idev || idev->cnf.disable_ipv6) {
+		NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
+		return false;
+	}
+
+	return true;
+}
+
 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
 				       int len)
 {
@@ -1272,12 +1286,11 @@
 	    !in6_dev->cnf.accept_ra_rtr_pref)
 		pref = ICMPV6_ROUTER_PREF_MEDIUM;
 #endif
-
+	/* routes added from RAs do not use nexthop objects */
 	rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
-
 	if (rt) {
-		neigh = ip6_neigh_lookup(&rt->fib6_nh.nh_gw,
-					 rt->fib6_nh.nh_dev, NULL,
+		neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
+					 rt->fib6_nh->fib_nh_dev, NULL,
 					  &ipv6_hdr(skb)->saddr);
 		if (!neigh) {
 			ND_PRINTK(0, err,
@@ -1306,8 +1319,8 @@
 			return;
 		}
 
-		neigh = ip6_neigh_lookup(&rt->fib6_nh.nh_gw,
-					 rt->fib6_nh.nh_dev, NULL,
+		neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
+					 rt->fib6_nh->fib_nh_dev, NULL,
 					  &ipv6_hdr(skb)->saddr);
 		if (!neigh) {
 			ND_PRINTK(0, err,
@@ -1533,7 +1546,7 @@
 
 	if (!ndopts.nd_opts_rh) {
 		ip6_redirect_no_header(skb, dev_net(skb->dev),
-					skb->dev->ifindex, 0);
+					skb->dev->ifindex);
 		return;
 	}
 
@@ -1783,6 +1796,8 @@
 		change_info = ptr;
 		if (change_info->flags_changed & IFF_NOARP)
 			neigh_changeaddr(&nd_tbl, dev);
+		if (!netif_carrier_ok(dev))
+			neigh_carrier_down(&nd_tbl, dev);
 		break;
 	case NETDEV_DOWN:
 		neigh_ifdown(&nd_tbl, dev);