From: Guus Sliepen <guus@tinc-vpn.org>
Date: Fri, 5 Jan 2018 18:58:28 +0000 (+0100)
Subject: Merge remote-tracking branch 'dechamps/ipip' into 1.1
X-Git-Tag: release-1.1pre16~44
X-Git-Url: https://git.tinc-vpn.org/git/browse?a=commitdiff_plain;h=bdeba3f9c26f9225c17c097ca490dc651cd40b90;hp=696dc2ad9743c62e56a6d21addb8c4e8efbffec1;p=tinc

Merge remote-tracking branch 'dechamps/ipip' into 1.1
---

diff --git a/src/route.c b/src/route.c
index a130e690..92dc1cd0 100644
--- a/src/route.c
+++ b/src/route.c
@@ -406,6 +406,15 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac
 		type = DATA(packet)[16] << 8 | DATA(packet)[17];
 	}
 
+	/* IP in IP (RFC 2003) packet */
+	if(type == ETH_P_IP && DATA(packet)[start + 9] == 4) {
+		start += 20;
+	}
+
+	if(packet->len <= start + 20) {
+		return;
+	}
+
 	if(type == ETH_P_IP && DATA(packet)[start + 9] == 6) {
 		start += (DATA(packet)[start] & 0xf) * 4;
 	} else if(type == ETH_P_IPV6 && DATA(packet)[start + 6] == 6) {