1 files changed, 83 insertions, 7 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index a8c65121..a0fcc47 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -912,6 +912,9 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
 	struct dst_entry *dst = &rt->dst;
 	struct fib_result res;
 
+	if (dst_metric_locked(dst, RTAX_MTU))
+		return;
+
 	if (dst->dev->mtu < mtu)
 		return;
 
@@ -962,7 +965,7 @@ void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
 }
 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
 
-void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
+static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
 {
 	const struct iphdr *iph = (const struct iphdr *) skb->data;
 	struct flowi4 fl4;
@@ -975,6 +978,53 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
 		ip_rt_put(rt);
 	}
 }
+
+void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
+{
+	const struct iphdr *iph = (const struct iphdr *) skb->data;
+	struct flowi4 fl4;
+	struct rtable *rt;
+	struct dst_entry *dst;
+	bool new = false;
+
+	bh_lock_sock(sk);
+	rt = (struct rtable *) __sk_dst_get(sk);
+
+	if (sock_owned_by_user(sk) || !rt) {
+		__ipv4_sk_update_pmtu(skb, sk, mtu);
+		goto out;
+	}
+
+	__build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
+
+	if (!__sk_dst_check(sk, 0)) {
+		rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
+		if (IS_ERR(rt))
+			goto out;
+
+		new = true;
+	}
+
+	__ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
+
+	dst = dst_check(&rt->dst, 0);
+	if (!dst) {
+		if (new)
+			dst_release(&rt->dst);
+
+		rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
+		if (IS_ERR(rt))
+			goto out;
+
+		new = true;
+	}
+
+	if (new)
+		__sk_dst_set(sk, &rt->dst);
+
+out:
+	bh_unlock_sock(sk);
+}
 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
 
 void ipv4_redirect(struct sk_buff *skb, struct net *net,
@@ -1120,7 +1170,7 @@ static unsigned int ipv4_mtu(const struct dst_entry *dst)
 	if (!mtu || time_after_eq(jiffies, rt->dst.expires))
 		mtu = dst_metric_raw(dst, RTAX_MTU);
 
-	if (mtu && rt_is_output_route(rt))
+	if (mtu)
 		return mtu;
 
 	mtu = dst->dev->mtu;
@@ -1785,6 +1835,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 	if (dev_out->flags & IFF_LOOPBACK)
 		flags |= RTCF_LOCAL;
 
+	do_cache = true;
 	if (type == RTN_BROADCAST) {
 		flags |= RTCF_BROADCAST | RTCF_LOCAL;
 		fi = NULL;
@@ -1793,6 +1844,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 		if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
 				     fl4->flowi4_proto))
 			flags &= ~RTCF_LOCAL;
+		else
+			do_cache = false;
 		/* If multicast route do not exist use
 		 * default one, but do not gateway in this case.
 		 * Yes, it is hack.
@@ -1802,8 +1855,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 	}
 
 	fnhe = NULL;
-	do_cache = fi != NULL;
-	if (fi) {
+	do_cache &= fi != NULL;
+	if (do_cache) {
 		struct rtable __rcu **prth;
 		struct fib_nh *nh = &FIB_RES_NH(*res);
 
@@ -2229,8 +2282,27 @@ static int rt_fill_info(struct net *net,  __be32 dst, __be32 src,
 	error = rt->dst.error;
 
 	if (rt_is_input_route(rt)) {
-		if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
-			goto nla_put_failure;
+#ifdef CONFIG_IP_MROUTE
+		if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
+		    IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
+			int err = ipmr_get_route(net, skb,
+						 fl4->saddr, fl4->daddr,
+						 r, nowait);
+			if (err <= 0) {
+				if (!nowait) {
+					if (err == 0)
+						return 0;
+					goto nla_put_failure;
+				} else {
+					if (err == -EMSGSIZE)
+						goto nla_put_failure;
+					error = err;
+				}
+			}
+		} else
+#endif
+			if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
+				goto nla_put_failure;
 	}
 
 	if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
@@ -2493,6 +2565,10 @@ static __net_init int sysctl_route_net_init(struct net *net)
 		tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
 		if (tbl == NULL)
 			goto err_dup;
+
+		/* Don't export sysctls to unprivileged users */
+		if (net->user_ns != &init_user_ns)
+			tbl[0].procname = NULL;
 	}
 	tbl[0].extra1 = net;
 
@@ -2597,7 +2673,7 @@ int __init ip_rt_init(void)
 		pr_err("Unable to create route proc files\n");
 #ifdef CONFIG_XFRM
 	xfrm_init();
-	xfrm4_init(ip_rt_max_size);
+	xfrm4_init();
 #endif
 	rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);