tunnel: drop packet if ECN present with not-ECT

[~andy/linux] / net / ipv4 / ipip.c

diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 618bde867ac11650c802423b13d9cb9804e6aca1..e15b45297c09f0043bda21ad366ce36d5a6e5824 100644 (file)
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -120,6 +120,10 @@
 #define HASH_SIZE  16
 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
 
+static bool log_ecn_error = true;
+module_param(log_ecn_error, bool, 0644);
+MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
+
 static int ipip_net_id __read_mostly;
 struct ipip_net {
        struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
@@ -400,28 +404,18 @@ out:
        return err;
 }
 
-static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph,
-                                       struct sk_buff *skb)
-{
-       struct iphdr *inner_iph = ip_hdr(skb);
-
-       if (INET_ECN_is_ce(outer_iph->tos))
-               IP_ECN_set_ce(inner_iph);
-}
-
 static int ipip_rcv(struct sk_buff *skb)
 {
        struct ip_tunnel *tunnel;
        const struct iphdr *iph = ip_hdr(skb);
+       int err;
 
        tunnel = ipip_tunnel_lookup(dev_net(skb->dev), iph->saddr, iph->daddr);
        if (tunnel != NULL) {
                struct pcpu_tstats *tstats;
 
-               if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
-                       kfree_skb(skb);
-                       return 0;
-               }
+               if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
+                       goto drop;
 
                secpath_reset(skb);
 
@@ -430,21 +424,35 @@ static int ipip_rcv(struct sk_buff *skb)
                skb->protocol = htons(ETH_P_IP);
                skb->pkt_type = PACKET_HOST;
 
+               __skb_tunnel_rx(skb, tunnel->dev);
+
+               err = IP_ECN_decapsulate(iph, skb);
+               if (unlikely(err)) {
+                       if (log_ecn_error)
+                               net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
+                                                    &iph->saddr, iph->tos);
+                       if (err > 1) {
+                               ++tunnel->dev->stats.rx_frame_errors;
+                               ++tunnel->dev->stats.rx_errors;
+                               goto drop;
+                       }
+               }
+
                tstats = this_cpu_ptr(tunnel->dev->tstats);
                u64_stats_update_begin(&tstats->syncp);
                tstats->rx_packets++;
                tstats->rx_bytes += skb->len;
                u64_stats_update_end(&tstats->syncp);
 
-               __skb_tunnel_rx(skb, tunnel->dev);
-
-               ipip_ecn_decapsulate(iph, skb);
-
                netif_rx(skb);
                return 0;
        }
 
        return -1;
+
+drop:
+       kfree_skb(skb);
+       return 0;
 }
 
 /*