add IPv6 support

This will be used to test the DHCPv6 helper.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 77 insertions, 0 deletions

diff --git a/l3_ipv6.c b/l3_ipv6.c
new file mode 100644
index 0000000..bf476c7
--- /dev/null
+++ b/l3_ipv6.c
@@ -0,0 +1,77 @@
+#include <stdlib.h>
+#include <string.h>
+#include <netinet/ip6.h>
+#include <linux/if_ether.h>
+
+#include "proto.h"
+
+#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
+
+static void
+l3_ipv6_ct_build_tuple(const uint8_t *pkt, struct nf_conntrack *ct)
+{
+	const struct ip6_hdr *ip6h = (const struct ip6_hdr *)pkt;
+
+	nfct_set_attr_u16(ct, ATTR_ORIG_L3PROTO, AF_INET6);
+	nfct_set_attr_u16(ct, ATTR_REPL_L3PROTO, AF_INET6);
+	nfct_set_attr(ct, ATTR_ORIG_IPV6_SRC, &ip6h->ip6_src);
+	nfct_set_attr(ct, ATTR_ORIG_IPV6_DST, &ip6h->ip6_dst);
+	nfct_set_attr(ct, ATTR_REPL_IPV6_SRC, &ip6h->ip6_src);
+	nfct_set_attr(ct, ATTR_REPL_IPV6_DST, &ip6h->ip6_dst);
+}
+
+static int
+l3_ipv6_ct_cmp_tuple_orig(const uint8_t *pkt, struct nf_conntrack *ct)
+{
+	const struct ip6_hdr *ip6h = (const struct ip6_hdr *)pkt;
+
+	if (memcmp(&ip6h->ip6_src, nfct_get_attr(ct, ATTR_ORIG_IPV6_SRC),
+		   sizeof(struct in6_addr)) == 0 &&
+	    memcmp(&ip6h->ip6_dst, nfct_get_attr(ct, ATTR_ORIG_IPV6_DST),
+		   sizeof(struct in6_addr)) == 0)
+		return 1;
+
+	return 0;
+}
+
+static int
+l3_ipv6_ct_cmp_tuple_repl(const uint8_t *pkt, struct nf_conntrack *ct)
+{
+	const struct ip6_hdr *ip6h = (const struct ip6_hdr *)pkt;
+
+	if (memcmp(&ip6h->ip6_src, nfct_get_attr(ct, ATTR_REPL_IPV6_SRC),
+		   sizeof(struct in6_addr)) == 0 &&
+	    memcmp(&ip6h->ip6_dst, nfct_get_attr(ct, ATTR_REPL_IPV6_DST),
+		   sizeof(struct in6_addr)) == 0)
+		return 1;
+
+	return 0;
+}
+
+static int l3_ipv6_pkt_l4proto_num(const uint8_t *pkt)
+{
+	const struct ip6_hdr *ip6h = (const struct ip6_hdr *)pkt;
+
+	return ip6h->ip6_nxt;
+}
+
+static int l3_ipv6_pkt_l3hdr_len(const uint8_t *pkt)
+{
+	return sizeof(struct ip6_hdr);
+}
+
+static struct cthelper_proto_l2l3_helper ipv4 = {
+	.l2protonum	= ETH_P_IPV6,
+	.l3protonum	= AF_INET6,
+	.l2hdr_len	= ETH_HLEN,
+	.l3ct_build	= l3_ipv6_ct_build_tuple,
+	.l3ct_cmp_orig	= l3_ipv6_ct_cmp_tuple_orig,
+	.l3ct_cmp_repl	= l3_ipv6_ct_cmp_tuple_repl,
+	.l3pkt_hdr_len	= l3_ipv6_pkt_l3hdr_len,
+	.l4pkt_proto	= l3_ipv6_pkt_l4proto_num,
+};
+
+void l2l3_ipv6_init(void)
+{
+	cthelper_proto_l2l3_helper_register(&ipv4);
+}