2 files changed, 68 insertions, 0 deletions

diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c
index fa371a8827cf..ea80450efe56 100644
--- a/net/ipv6/calipso.c
+++ b/net/ipv6/calipso.c
@@ -321,6 +321,47 @@ doi_walk_return:
 }
 
 /**
+ * calipso_validate - Validate a CALIPSO option
+ * @skb: the packet
+ * @option: the start of the option
+ *
+ * Description:
+ * This routine is called to validate a CALIPSO option.
+ * If the option is valid then %true is returned, otherwise
+ * %false is returned.
+ *
+ * The caller should have already checked that the length of the
+ * option (including the TLV header) is >= 10 and that the catmap
+ * length is consistent with the option length.
+ *
+ * We leave checks on the level and categories to the socket layer.
+ */
+bool calipso_validate(const struct sk_buff *skb, const unsigned char *option)
+{
+        struct calipso_doi *doi_def;
+        bool ret_val;
+        u16 crc, len = option[1] + 2;
+        static const u8 zero[2];
+
+        /* The original CRC runs over the option including the TLV header
+         * with the CRC-16 field (at offset 8) zeroed out. */
+        crc = crc_ccitt(0xffff, option, 8);
+        crc = crc_ccitt(crc, zero, sizeof(zero));
+        if (len > 10)
+                crc = crc_ccitt(crc, option + 10, len - 10);
+        crc = ~crc;
+        if (option[8] != (crc & 0xff) || option[9] != ((crc >> 8) & 0xff))
+                return false;
+
+        rcu_read_lock();
+        doi_def = calipso_doi_search(get_unaligned_be32(option + 2));
+        ret_val = !!doi_def;
+        rcu_read_unlock();
+
+        return ret_val;
+}
+
+/**
  * calipso_map_cat_hton - Perform a category mapping from host to network
  * @doi_def: the DOI definition
  * @secattr: the security attributes
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, }
 };