[IPV4]: reset IPCB flags when neccessary

Reset IPSKB_XFRM_TUNNEL_SIZE flags in ipip and ip_gre hard_start_xmit
function before the packet reenters IP. This is neccessary so the
encapsulated packets are checked not to be oversized in xfrm4_output.c
again. Reset all flags in sit when a packet changes its address family.

Also remove some obsolete IPSKB flags.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -37,11 +37,9 @@ struct inet_skb_parm
 	struct ip_options	opt;		/* Compiled IP options		*/
 	unsigned char		flags;
 
-#define IPSKB_MASQUERADED	1
-#define IPSKB_TRANSLATED	2
-#define IPSKB_FORWARDED		4
-#define IPSKB_XFRM_TUNNEL_SIZE	8
-#define IPSKB_FRAG_COMPLETE	16
+#define IPSKB_FORWARDED		1
+#define IPSKB_XFRM_TUNNEL_SIZE	2
+#define IPSKB_FRAG_COMPLETE	4
 };
 
 struct ipcm_cookie

net/ipv4/ip_gre.c

@@ -832,6 +832,7 @@ static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 	skb->h.raw = skb->nh.raw;
 	skb->nh.raw = skb_push(skb, gre_hlen);
 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+	IPCB(skb)->flags &= ~IPSKB_XFRM_TUNNEL_SIZE;
 	dst_release(skb->dst);
 	skb->dst = &rt->u.dst;
 

net/ipv4/ipip.c

@@ -621,6 +621,7 @@ static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 	skb->h.raw = skb->nh.raw;
 	skb->nh.raw = skb_push(skb, sizeof(struct iphdr));
 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+	IPCB(skb)->flags &= ~IPSKB_XFRM_TUNNEL_SIZE;
 	dst_release(skb->dst);
 	skb->dst = &rt->u.dst;
 

net/ipv6/sit.c

@@ -381,6 +381,7 @@ static int ipip6_rcv(struct sk_buff *skb)
 		skb->mac.raw = skb->nh.raw;
 		skb->nh.raw = skb->data;
 		memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
+		IPCB(skb)->flags = 0;
 		skb->protocol = htons(ETH_P_IPV6);
 		skb->pkt_type = PACKET_HOST;
 		tunnel->stat.rx_packets++;
@@ -552,6 +553,7 @@ static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 	skb->h.raw = skb->nh.raw;
 	skb->nh.raw = skb_push(skb, sizeof(struct iphdr));
 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+	IPCB(skb)->flags = 0;
 	dst_release(skb->dst);
 	skb->dst = &rt->u.dst;