tests: conntrackd: add cthelper-test infrastructure

This patch adds the automated testing infrastructure the user-space
helpers. Basically, this adds the `cthelper-test' program that can
be invoked from the command line:

 ./cthelper-test pcaps/oracle-tns-redirect.pcap tns tcp 1521

To test the helper with one PCAP file that contains traces of Oracle TNS
traffic. It also provides tweaks to test the DNAT content mangling code:

 ./cthelper-test pcaps/oracle-tns-redirect.pcap tns tcp 1521 dnat

This will also allow fuzzy testing of user-space helper, for further
validation, not yet implemented.

To compile this tool, you have to run:

./configure
make check

under the qa/cthelper-test/ directory. I'm doing like this because
this directory is not included in the standalone tarball that
make distcheck generates (I don't want to bloat it with development
tools that can be retrieved from the git repository).

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

1 files changed, 49 insertions, 0 deletions

diff --git a/tests/conntrackd/cthelper/proto.c b/tests/conntrackd/cthelper/proto.c
new file mode 100755
index 0000000..6a1f345
--- /dev/null
+++ b/tests/conntrackd/cthelper/proto.c
@@ -0,0 +1,49 @@
+#include <stdlib.h>
+#include <netinet/in.h>
+#include <linux/if_ether.h>
+
+#include "linux_list.h"
+#include "proto.h"
+
+static LIST_HEAD(l2l3_helper_list);
+static LIST_HEAD(l4_helper_list);
+
+struct cthelper_proto_l2l3_helper *
+cthelper_proto_l2l3_helper_find(const uint8_t *pkt,
+				unsigned int *l4protonum,
+				unsigned int *l3hdr_len)
+{
+	const struct ethhdr *eh = (const struct ethhdr *)pkt;
+	struct cthelper_proto_l2l3_helper *cur;
+
+	list_for_each_entry(cur, &l2l3_helper_list, head) {
+		if (ntohs(cur->l2protonum) == eh->h_proto) {
+			*l4protonum = cur->l4pkt_proto(pkt + ETH_HLEN);
+			*l3hdr_len = cur->l3pkt_hdr_len(pkt + ETH_HLEN);
+			return cur;
+		}
+	}
+	return NULL;
+}
+
+void cthelper_proto_l2l3_helper_register(struct cthelper_proto_l2l3_helper *h)
+{
+	list_add(&h->head, &l2l3_helper_list);
+}
+
+struct cthelper_proto_l4_helper *
+cthelper_proto_l4_helper_find(const uint8_t *pkt, unsigned int l4protocol)
+{
+	struct cthelper_proto_l4_helper *cur;
+
+	list_for_each_entry(cur, &l4_helper_list, head) {
+		if (cur->l4protonum == l4protocol)
+			return cur;
+	}
+	return NULL;
+}
+
+void cthelper_proto_l4_helper_register(struct cthelper_proto_l4_helper *h)
+{
+	list_add(&h->head, &l4_helper_list);
+}