1 files changed, 31 insertions, 12 deletions

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 31936d387cfd..205a2b8a5a84 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -179,6 +179,7 @@ static __be16 tnl_flags_to_gre_flags(__be16 tflags)
 	return flags;
 }
 
+/* Fills in tpi and returns header length to be pulled. */
 static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 			    bool *csum_err)
 {
@@ -238,7 +239,7 @@ static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 				return -EINVAL;
 		}
 	}
-	return iptunnel_pull_header(skb, hdr_len, tpi->proto, false);
+	return hdr_len;
 }
 
 static void ipgre_err(struct sk_buff *skb, u32 info,
@@ -341,7 +342,7 @@ static void gre_err(struct sk_buff *skb, u32 info)
 	struct tnl_ptk_info tpi;
 	bool csum_err = false;
 
-	if (parse_gre_header(skb, &tpi, &csum_err)) {
+	if (parse_gre_header(skb, &tpi, &csum_err) < 0) {
 		if (!csum_err)		/* ignore csum errors. */
 			return;
 	}
@@ -419,6 +420,7 @@ static int gre_rcv(struct sk_buff *skb)
 {
 	struct tnl_ptk_info tpi;
 	bool csum_err = false;
+	int hdr_len;
 
 #ifdef CONFIG_NET_IPGRE_BROADCAST
 	if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
@@ -428,7 +430,10 @@ static int gre_rcv(struct sk_buff *skb)
 	}
 #endif
 
-	if (parse_gre_header(skb, &tpi, &csum_err) < 0)
+	hdr_len = parse_gre_header(skb, &tpi, &csum_err);
+	if (hdr_len < 0)
+		goto drop;
+	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false) < 0)
 		goto drop;
 
 	if (ipgre_rcv(skb, &tpi) == PACKET_RCVD)
@@ -523,7 +528,8 @@ static struct rtable *gre_get_rt(struct sk_buff *skb,
 	return ip_route_output_key(net, fl);
 }
 
-static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev)
+static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
+			__be16 proto)
 {
 	struct ip_tunnel_info *tun_info;
 	const struct ip_tunnel_key *key;
@@ -575,7 +581,7 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 
 	flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY);
-	build_header(skb, tunnel_hlen, flags, htons(ETH_P_TEB),
+	build_header(skb, tunnel_hlen, flags, proto,
 		     tunnel_id_to_key(tun_info->key.tun_id), 0);
 
 	df = key->tun_flags & TUNNEL_DONT_FRAGMENT ?  htons(IP_DF) : 0;
@@ -616,7 +622,7 @@ static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
 	const struct iphdr *tnl_params;
 
 	if (tunnel->collect_md) {
-		gre_fb_xmit(skb, dev);
+		gre_fb_xmit(skb, dev, skb->protocol);
 		return NETDEV_TX_OK;
 	}
 
@@ -660,7 +666,7 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
 	struct ip_tunnel *tunnel = netdev_priv(dev);
 
 	if (tunnel->collect_md) {
-		gre_fb_xmit(skb, dev);
+		gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
 		return NETDEV_TX_OK;
 	}
 
@@ -862,9 +868,16 @@ static void __gre_tunnel_init(struct net_device *dev)
 	dev->hw_features	|= GRE_FEATURES;
 
 	if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
-		/* TCP offload with GRE SEQ is not supported. */
-		dev->features    |= NETIF_F_GSO_SOFTWARE;
-		dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+		/* TCP offload with GRE SEQ is not supported, nor
+		 * can we support 2 levels of outer headers requiring
+		 * an update.
+		 */
+		if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
+		    (tunnel->encap.type == TUNNEL_ENCAP_NONE)) {
+			dev->features    |= NETIF_F_GSO_SOFTWARE;
+			dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+		}
+
 		/* Can use a lockless transmit, unless we generate
 		 * output sequences
 		 */
@@ -886,7 +899,7 @@ static int ipgre_tunnel_init(struct net_device *dev)
 	netif_keep_dst(dev);
 	dev->addr_len		= 4;
 
-	if (iph->daddr) {
+	if (iph->daddr && !tunnel->collect_md) {
 #ifdef CONFIG_NET_IPGRE_BROADCAST
 		if (ipv4_is_multicast(iph->daddr)) {
 			if (!iph->saddr)
@@ -895,8 +908,9 @@ static int ipgre_tunnel_init(struct net_device *dev)
 			dev->header_ops = &ipgre_header_ops;
 		}
 #endif
-	} else
+	} else if (!tunnel->collect_md) {
 		dev->header_ops = &ipgre_header_ops;
+	}
 
 	return ip_tunnel_init(dev);
 }
@@ -939,6 +953,11 @@ static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
 	if (flags & (GRE_VERSION|GRE_ROUTING))
 		return -EINVAL;
 
+	if (data[IFLA_GRE_COLLECT_METADATA] &&
+	    data[IFLA_GRE_ENCAP_TYPE] &&
+	    nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
+		return -EINVAL;
+
 	return 0;
 }