bsf: add support for IPv6 address filtering

This patch adds support to auto-generate BSF code for IPv6. It
requires a Linux kernel >= 2.6.29. The maximum number of addresses
is limited to 20 (12 BSF lines per IPv6 address comparison). I am
not sure that to remove this limit is useful given that oprofile
does not show very good numbers for very large (in terms of lines)
filters. This completes one feature that is available in IPv4 but
that was missing in IPv6.

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

1 files changed, 13 insertions, 0 deletions

diff --git a/utils/conntrack_filter.c b/utils/conntrack_filter.c
index 7c44c50..0252fbf 100644
--- a/utils/conntrack_filter.c
+++ b/utils/conntrack_filter.c
@@ -66,6 +66,19 @@ int main()
 
 	nfct_filter_add_attr(filter, NFCT_FILTER_SRC_IPV4, &filter_ipv4);
 
+	/* BSF always wants data in host-byte order */
+	struct nfct_filter_ipv6 filter_ipv6 = {
+		.addr = { 0x0, 0x0, 0x0, 0x1 },
+		.mask = { 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff },
+	}; 
+
+	/* ignore whatever that comes from ::1 (loopback) */
+	nfct_filter_set_logic(filter,
+			      NFCT_FILTER_SRC_IPV6,
+			      NFCT_FILTER_LOGIC_NEGATIVE);
+
+	nfct_filter_add_attr(filter, NFCT_FILTER_SRC_IPV6, &filter_ipv6);
+
 	if (nfct_filter_attach(nfct_fd(h), filter) == -1) {
 		perror("nfct_filter_attach");
 		return 0;