[PATCH net-next v4 3/6] xfrm: add route lookup to xfrm4_rcv_encap

[Sabrina Dubroca]

At this point, with TCP encapsulation, the dst may be gone, but
xfrm_input needs one.

Signed-off-by: Sabrina Dubroca <s...@queasysnail.net>
---
 net/ipv4/xfrm4_protocol.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/ipv4/xfrm4_protocol.c b/net/ipv4/xfrm4_protocol.c
index 8a4285712808..ea595c8549c7 100644
--- a/net/ipv4/xfrm4_protocol.c
+++ b/net/ipv4/xfrm4_protocol.c
@@ -72,6 +72,14 @@ int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 
spi,
        if (!head)
                goto out;
 
+       if (!skb_dst(skb)) {
+               const struct iphdr *iph = ip_hdr(skb);
+
+               if (ip_route_input_noref(skb, iph->daddr, iph->saddr,
+                                        iph->tos, skb->dev))
+                       goto drop;
+       }
+
        for_each_protocol_rcu(*head, handler)
                if ((ret = handler->input_handler(skb, nexthdr, spi, 
encap_type)) != -EINVAL)
                        return ret;
@@ -79,6 +87,7 @@ int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 
spi,
 out:
        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
 
+drop:
        kfree_skb(skb);
        return 0;
 }
-- 
2.23.0