[IPSEC]: Use xfrm_rcv for xfrm tunnel packets.

net/ipv4/ipcomp.c

@@ -279,6 +279,7 @@ static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
 	t->props.family = AF_INET;
 	t->props.mode = 1;
 	t->props.saddr.a4 = x->props.saddr.a4;
+	t->props.flags = x->props.flags;
 	
 	t->type = xfrm_get_type(IPPROTO_IPIP, t->props.family);
 	if (t->type == NULL)

net/ipv4/xfrm4_input.c

@@ -27,6 +27,20 @@ static inline void ipip_ecn_decapsulate(struct iphdr *outer_iph, struct sk_buff
 		IP_ECN_set_ce(inner_iph);
 }
 
+static int xfrm4_parse_spi(struct sk_buff *skb, u8 nexthdr, u32 *spi, u32 *seq)
+{
+	switch (nexthdr) {
+	case IPPROTO_IPIP:
+		if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+			return -EINVAL;
+		*spi = skb->nh.iph->saddr;
+		*seq = 0;
+		return 0;
+	}
+
+	return xfrm_parse_spi(skb, nexthdr, spi, seq);
+}
+
 int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
 {
 	int err;
@@ -36,7 +50,7 @@ int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
 	int xfrm_nr = 0;
 	int decaps = 0;
 
-	if ((err = xfrm_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) != 0)
+	if ((err = xfrm4_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) != 0)
 		goto drop;
 
 	do {

net/ipv4/xfrm4_tunnel.c

@@ -83,31 +83,8 @@ static int ipip_output(struct sk_buff *skb)
 	return err;
 }
 
-static inline void ipip_ecn_decapsulate(struct iphdr *outer_iph, struct sk_buff *skb)
-{
-	struct iphdr *inner_iph = skb->nh.iph;
-
-	if (INET_ECN_is_ce(outer_iph->tos) &&
-	    INET_ECN_is_not_ce(inner_iph->tos))
-		IP_ECN_set_ce(inner_iph);
-}
-
 static int ipip_xfrm_rcv(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
 {
-	struct iphdr *outer_iph = skb->nh.iph;
-
-	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
-		return -EINVAL;
-	skb->mac.raw = skb->nh.raw;
-	skb->nh.raw = skb->data;
-	memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
-	dst_release(skb->dst);
-	skb->dst = NULL;
-	skb->protocol = htons(ETH_P_IP);
-	skb->pkt_type = PACKET_HOST;
-	ipip_ecn_decapsulate(outer_iph, skb);
-	netif_rx(skb);
-
 	return 0;
 }
 
@@ -149,46 +126,12 @@ int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler)
 static int ipip_rcv(struct sk_buff *skb)
 {
 	struct xfrm_tunnel *handler = ipip_handler;
-	struct xfrm_state *x = NULL;
-	int err;
 
 	/* Tunnel devices take precedence.  */
-	if (handler) {
-		err = handler->handler(skb);
-		if (!err)
-			goto out;
-	}
+	if (handler && handler->handler(skb) == 0)
+		return 0;
 
-	x = xfrm_state_lookup((xfrm_address_t *)&skb->nh.iph->daddr,
-			      skb->nh.iph->saddr,
-			      IPPROTO_IPIP, AF_INET);
-
-	if (!x)
-		goto drop;
-
-	spin_lock(&x->lock);
-
-	if (unlikely(x->km.state != XFRM_STATE_VALID))
-		goto drop_unlock;
-
-	err = ipip_xfrm_rcv(x, NULL, skb);
-	if (err)
-		goto drop_unlock;
-
-	x->curlft.bytes += skb->len;
-	x->curlft.packets++;
-	spin_unlock(&x->lock);
-	xfrm_state_put(x);
-out:	
-	return err;
-
-drop_unlock:
-	spin_unlock(&x->lock);
-	xfrm_state_put(x);
-drop:
-	err = NET_RX_DROP;
-	kfree_skb(skb);
-	goto out;
+	return xfrm4_rcv_encap(skb, 0);
 }
 
 static void ipip_err(struct sk_buff *skb, u32 info)