From 2e532b702834c07f614caf4489feb691e713232a Mon Sep 17 00:00:00 2001
From: Huw Davies <huw@codeweavers.com>
Date: Mon, 27 Jun 2016 15:06:17 -0400
Subject: calipso: Add validation of CALIPSO option.

Lengths, checksum and the DOI are checked.  Checking of the
level and categories are left for the socket layer.

CRC validation is performed in the calipso module to avoid
unconditionally linking crc_ccitt() into ipv6.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
---
 net/ipv6/exthdrs.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

(limited to 'net/ipv6/exthdrs.c')

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index d5fd3e799f86..0f69cab39986 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -43,6 +43,7 @@
 #include <net/ndisc.h>
 #include <net/ip6_route.h>
 #include <net/addrconf.h>
+#include <net/calipso.h>
 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 #include <net/xfrm.h>
 #endif
@@ -603,6 +604,28 @@ drop:
 	return false;
 }
 
+/* CALIPSO RFC 5570 */
+
+static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
+{
+	const unsigned char *nh = skb_network_header(skb);
+
+	if (nh[optoff + 1] < 8)
+		goto drop;
+
+	if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1])
+		goto drop;
+
+	if (!calipso_validate(skb, nh + optoff))
+		goto drop;
+
+	return true;
+
+drop:
+	kfree_skb(skb);
+	return false;
+}
+
 static const struct tlvtype_proc tlvprochopopt_lst[] = {
 	{
 		.type	= IPV6_TLV_ROUTERALERT,
@@ -612,6 +635,10 @@ static const struct tlvtype_proc tlvprochopopt_lst[] = {
 		.type	= IPV6_TLV_JUMBO,
 		.func	= ipv6_hop_jumbo,
 	},
+	{
+		.type	= IPV6_TLV_CALIPSO,
+		.func	= ipv6_hop_calipso,
+	},
 	{ -1, }
 };
 
-- 
cgit