1 files changed, 19 insertions, 13 deletions

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 247ad7c298f7..71fde6cafb35 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -311,7 +311,7 @@ static int ndisc_constructor(struct neighbour *neigh)
 	bool is_multicast = ipv6_addr_is_multicast(addr);
 
 	in6_dev = in6_dev_get(dev);
-	if (in6_dev == NULL) {
+	if (!in6_dev) {
 		return -EINVAL;
 	}
 
@@ -356,7 +356,7 @@ static int pndisc_constructor(struct pneigh_entry *n)
 	struct in6_addr maddr;
 	struct net_device *dev = n->dev;
 
-	if (dev == NULL || __in6_dev_get(dev) == NULL)
+	if (!dev || !__in6_dev_get(dev))
 		return -EINVAL;
 	addrconf_addr_solict_mult(addr, &maddr);
 	ipv6_dev_mc_inc(dev, &maddr);
@@ -369,7 +369,7 @@ static void pndisc_destructor(struct pneigh_entry *n)
 	struct in6_addr maddr;
 	struct net_device *dev = n->dev;
 
-	if (dev == NULL || __in6_dev_get(dev) == NULL)
+	if (!dev || !__in6_dev_get(dev))
 		return;
 	addrconf_addr_solict_mult(addr, &maddr);
 	ipv6_dev_mc_dec(dev, &maddr);
@@ -560,7 +560,7 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
 	int optlen = 0;
 	struct nd_msg *msg;
 
-	if (saddr == NULL) {
+	if (!saddr) {
 		if (ipv6_get_lladdr(dev, &addr_buf,
 				   (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
 			return;
@@ -1030,13 +1030,13 @@ static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
 	size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
 
 	skb = nlmsg_new(msg_size, GFP_ATOMIC);
-	if (skb == NULL) {
+	if (!skb) {
 		err = -ENOBUFS;
 		goto errout;
 	}
 
 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
-	if (nlh == NULL) {
+	if (!nlh) {
 		goto nla_put_failure;
 	}
 
@@ -1049,8 +1049,7 @@ static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
 
 	memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
 
-	if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
-		    &ipv6_hdr(ra)->saddr))
+	if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
 		goto nla_put_failure;
 	nlmsg_end(skb, nlh);
 
@@ -1104,7 +1103,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 	 */
 
 	in6_dev = __in6_dev_get(skb->dev);
-	if (in6_dev == NULL) {
+	if (!in6_dev) {
 		ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
 			  skb->dev->name);
 		return;
@@ -1199,11 +1198,11 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 
 	ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, for dev: %s\n",
 		  rt, lifetime, skb->dev->name);
-	if (rt == NULL && lifetime) {
+	if (!rt && lifetime) {
 		ND_PRINTK(3, info, "RA: adding default router\n");
 
 		rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
-		if (rt == NULL) {
+		if (!rt) {
 			ND_PRINTK(0, err,
 				  "RA: %s failed to add default route\n",
 				  __func__);
@@ -1211,7 +1210,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 		}
 
 		neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
-		if (neigh == NULL) {
+		if (!neigh) {
 			ND_PRINTK(0, err,
 				  "RA: %s got default router without neighbour\n",
 				  __func__);
@@ -1226,7 +1225,14 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 	if (rt)
 		rt6_set_expires(rt, jiffies + (HZ * lifetime));
 	if (ra_msg->icmph.icmp6_hop_limit) {
-		in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
+		/* Only set hop_limit on the interface if it is higher than
+		 * the current hop_limit.
+		 */
+		if (in6_dev->cnf.hop_limit < ra_msg->icmph.icmp6_hop_limit) {
+			in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
+		} else {
+			ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than current\n");
+		}
 		if (rt)
 			dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
 				       ra_msg->icmph.icmp6_hop_limit);