1 files changed, 118 insertions, 29 deletions

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 7ee5cb96db34..1b4a4a953675 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -566,6 +566,70 @@ static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
 	return false;
 }
 
+/* Checks if an address matches an address on the tunnel interface.
+ * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
+ * Long story:
+ * This function is called after we considered the packet as spoofed
+ * in is_spoofed_6rd.
+ * We may have a router that is doing NAT for proto 41 packets
+ * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
+ * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
+ * function will return true, dropping the packet.
+ * But, we can still check if is spoofed against the IP
+ * addresses associated with the interface.
+ */
+static bool only_dnatted(const struct ip_tunnel *tunnel,
+	const struct in6_addr *v6dst)
+{
+	int prefix_len;
+
+#ifdef CONFIG_IPV6_SIT_6RD
+	prefix_len = tunnel->ip6rd.prefixlen + 32
+		- tunnel->ip6rd.relay_prefixlen;
+#else
+	prefix_len = 48;
+#endif
+	return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
+}
+
+/* Returns true if a packet is spoofed */
+static bool packet_is_spoofed(struct sk_buff *skb,
+			      const struct iphdr *iph,
+			      struct ip_tunnel *tunnel)
+{
+	const struct ipv6hdr *ipv6h;
+
+	if (tunnel->dev->priv_flags & IFF_ISATAP) {
+		if (!isatap_chksrc(skb, iph, tunnel))
+			return true;
+
+		return false;
+	}
+
+	if (tunnel->dev->flags & IFF_POINTOPOINT)
+		return false;
+
+	ipv6h = ipv6_hdr(skb);
+
+	if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
+		net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
+				     &iph->saddr, &ipv6h->saddr,
+				     &iph->daddr, &ipv6h->daddr);
+		return true;
+	}
+
+	if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
+		return false;
+
+	if (only_dnatted(tunnel, &ipv6h->daddr))
+		return false;
+
+	net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
+			     &iph->saddr, &ipv6h->saddr,
+			     &iph->daddr, &ipv6h->daddr);
+	return true;
+}
+
 static int ipip6_rcv(struct sk_buff *skb)
 {
 	const struct iphdr *iph = ip_hdr(skb);
@@ -586,19 +650,9 @@ static int ipip6_rcv(struct sk_buff *skb)
 		IPCB(skb)->flags = 0;
 		skb->protocol = htons(ETH_P_IPV6);
 
-		if (tunnel->dev->priv_flags & IFF_ISATAP) {
-			if (!isatap_chksrc(skb, iph, tunnel)) {
-				tunnel->dev->stats.rx_errors++;
-				goto out;
-			}
-		} else if (!(tunnel->dev->flags&IFF_POINTOPOINT)) {
-			if (is_spoofed_6rd(tunnel, iph->saddr,
-					   &ipv6_hdr(skb)->saddr) ||
-			    is_spoofed_6rd(tunnel, iph->daddr,
-					   &ipv6_hdr(skb)->daddr)) {
-				tunnel->dev->stats.rx_errors++;
-				goto out;
-			}
+		if (packet_is_spoofed(skb, iph, tunnel)) {
+			tunnel->dev->stats.rx_errors++;
+			goto out;
 		}
 
 		__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
@@ -748,7 +802,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 			neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 
 		if (neigh == NULL) {
-			net_dbg_ratelimited("sit: nexthop == NULL\n");
+			net_dbg_ratelimited("nexthop == NULL\n");
 			goto tx_error;
 		}
 
@@ -777,7 +831,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 			neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 
 		if (neigh == NULL) {
-			net_dbg_ratelimited("sit: nexthop == NULL\n");
+			net_dbg_ratelimited("nexthop == NULL\n");
 			goto tx_error;
 		}
 
@@ -879,10 +933,9 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 		ttl = iph6->hop_limit;
 	tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 
-	if (likely(!skb->encapsulation)) {
-		skb_reset_inner_headers(skb);
-		skb->encapsulation = 1;
-	}
+	skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT);
+	if (IS_ERR(skb))
+		goto out;
 
 	err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, IPPROTO_IPV6, tos,
 			    ttl, df, !net_eq(tunnel->net, dev_net(dev)));
@@ -892,8 +945,9 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 tx_error_icmp:
 	dst_link_failure(skb);
 tx_error:
-	dev->stats.tx_errors++;
 	dev_kfree_skb(skb);
+out:
+	dev->stats.tx_errors++;
 	return NETDEV_TX_OK;
 }
 
@@ -902,13 +956,15 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct ip_tunnel *tunnel = netdev_priv(dev);
 	const struct iphdr  *tiph = &tunnel->parms.iph;
 
-	if (likely(!skb->encapsulation)) {
-		skb_reset_inner_headers(skb);
-		skb->encapsulation = 1;
-	}
+	skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP);
+	if (IS_ERR(skb))
+		goto out;
 
 	ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP);
 	return NETDEV_TX_OK;
+out:
+	dev->stats.tx_errors++;
+	return NETDEV_TX_OK;
 }
 
 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
@@ -1238,6 +1294,12 @@ static void ipip6_dev_free(struct net_device *dev)
 	free_netdev(dev);
 }
 
+#define SIT_FEATURES (NETIF_F_SG	   | \
+		      NETIF_F_FRAGLIST	   | \
+		      NETIF_F_HIGHDMA	   | \
+		      NETIF_F_GSO_SOFTWARE | \
+		      NETIF_F_HW_CSUM)
+
 static void ipip6_tunnel_setup(struct net_device *dev)
 {
 	dev->netdev_ops		= &ipip6_netdev_ops;
@@ -1251,11 +1313,14 @@ static void ipip6_tunnel_setup(struct net_device *dev)
 	dev->iflink		= 0;
 	dev->addr_len		= 4;
 	dev->features		|= NETIF_F_LLTX;
+	dev->features		|= SIT_FEATURES;
+	dev->hw_features	|= SIT_FEATURES;
 }
 
 static int ipip6_tunnel_init(struct net_device *dev)
 {
 	struct ip_tunnel *tunnel = netdev_priv(dev);
+	int i;
 
 	tunnel->dev = dev;
 	tunnel->net = dev_net(dev);
@@ -1268,6 +1333,12 @@ static int ipip6_tunnel_init(struct net_device *dev)
 	if (!dev->tstats)
 		return -ENOMEM;
 
+	for_each_possible_cpu(i) {
+		struct pcpu_tstats *ipip6_tunnel_stats;
+		ipip6_tunnel_stats = per_cpu_ptr(dev->tstats, i);
+		u64_stats_init(&ipip6_tunnel_stats->syncp);
+	}
+
 	return 0;
 }
 
@@ -1277,6 +1348,7 @@ static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
 	struct iphdr *iph = &tunnel->parms.iph;
 	struct net *net = dev_net(dev);
 	struct sit_net *sitn = net_generic(net, sit_net_id);
+	int i;
 
 	tunnel->dev = dev;
 	tunnel->net = dev_net(dev);
@@ -1290,6 +1362,13 @@ static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
 	dev->tstats = alloc_percpu(struct pcpu_tstats);
 	if (!dev->tstats)
 		return -ENOMEM;
+
+	for_each_possible_cpu(i) {
+		struct pcpu_tstats *ipip6_fb_stats;
+		ipip6_fb_stats = per_cpu_ptr(dev->tstats, i);
+		u64_stats_init(&ipip6_fb_stats->syncp);
+	}
+
 	dev_hold(dev);
 	rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
 	return 0;
@@ -1540,6 +1619,15 @@ static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
 #endif
 };
 
+static void ipip6_dellink(struct net_device *dev, struct list_head *head)
+{
+	struct net *net = dev_net(dev);
+	struct sit_net *sitn = net_generic(net, sit_net_id);
+
+	if (dev != sitn->fb_tunnel_dev)
+		unregister_netdevice_queue(dev, head);
+}
+
 static struct rtnl_link_ops sit_link_ops __read_mostly = {
 	.kind		= "sit",
 	.maxtype	= IFLA_IPTUN_MAX,
@@ -1551,6 +1639,7 @@ static struct rtnl_link_ops sit_link_ops __read_mostly = {
 	.changelink	= ipip6_changelink,
 	.get_size	= ipip6_get_size,
 	.fill_info	= ipip6_fill_info,
+	.dellink	= ipip6_dellink,
 };
 
 static struct xfrm_tunnel sit_handler __read_mostly = {
@@ -1565,9 +1654,10 @@ static struct xfrm_tunnel ipip_handler __read_mostly = {
 	.priority	=	2,
 };
 
-static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
+static void __net_exit sit_destroy_tunnels(struct net *net,
+					   struct list_head *head)
 {
-	struct net *net = dev_net(sitn->fb_tunnel_dev);
+	struct sit_net *sitn = net_generic(net, sit_net_id);
 	struct net_device *dev, *aux;
 	int prio;
 
@@ -1612,6 +1702,7 @@ static int __net_init sit_init_net(struct net *net)
 		goto err_alloc_dev;
 	}
 	dev_net_set(sitn->fb_tunnel_dev, net);
+	sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
 	/* FB netdevice is special: we have one, and only one per netns.
 	 * Allowing to move it to another netns is clearly unsafe.
 	 */
@@ -1641,12 +1732,10 @@ err_alloc_dev:
 
 static void __net_exit sit_exit_net(struct net *net)
 {
-	struct sit_net *sitn = net_generic(net, sit_net_id);
 	LIST_HEAD(list);
 
 	rtnl_lock();
-	sit_destroy_tunnels(sitn, &list);
-	unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
+	sit_destroy_tunnels(net, &list);
 	unregister_netdevice_many(&list);
 	rtnl_unlock();
 }