From: Tobias Brunner <tobias@strongswan.org>
Date: Thu, 21 Dec 2017 16:32:24 +0000 (+0100)
Subject: ipv6: Reinject IPv6 packets if IPsec policy matches after SNAT
X-Git-Tag: v4.15.17~162
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4dfb698be2a5ede1bd887fb10f79e97564fba4aa;p=thirdparty%2Fkernel%2Fstable.git

ipv6: Reinject IPv6 packets if IPsec policy matches after SNAT


[ Upstream commit 09ee9dba9611cd382fd360a99ad1c2fa23bfdca8 ]

If SNAT modifies the source address the resulting packet might match
an IPsec policy, reinject the packet if that's the case.

The exact same thing is already done for IPv4.

Signed-off-by: Tobias Brunner <tobias@strongswan.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 3763dc01e3747..0f874b48c1b5f 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -138,6 +138,14 @@ static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *s
 		return ret;
 	}
 
+#if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
+	/* Policy lookup after SNAT yielded a new policy */
+	if (skb_dst(skb)->xfrm) {
+		IPCB(skb)->flags |= IPSKB_REROUTED;
+		return dst_output(net, sk, skb);
+	}
+#endif
+
 	if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
 	    dst_allfrag(skb_dst(skb)) ||
 	    (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))