1 files changed, 91 insertions, 0 deletions
diff --git a/ct.c b/ct.c
new file mode 100755
index 0000000..1c17336
--- /dev/null
+++ b/ct.c
@@ -0,0 +1,91 @@
+#include <stdlib.h>
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+
+#include <linux/if_ether.h>
+
+#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
+
+#include "proto.h"
+#include "helper.h"
+#include "myct.h"
+#include "ct.h"
+
+static LIST_HEAD(ct_list);
+
+struct nf_ct_entry *
+ct_alloc(const uint8_t *pkt, unsigned int l3hdr_len,
+	 struct cthelper_proto_l2l3_helper *l3h,
+	 struct cthelper_proto_l4_helper *l4h)
+{
+	struct nf_ct_entry *ct;
+
+	ct = calloc(1, sizeof(struct nf_ct_entry));
+	if (ct == NULL)
+		return NULL;
+
+	ct->myct = calloc(1, sizeof(struct myct));
+	if (ct->myct == NULL) {
+		free(ct);
+		return NULL;
+	}
+	ct->myct->ct = nfct_new();
+	if (ct->myct->ct == NULL) {
+		free(ct->myct);
+		free(ct);
+		return NULL;
+	}
+	/* FIXME: use good private helper size */
+	ct->myct->priv_data = calloc(1, 128);
+	if (ct->myct->priv_data == NULL) {
+		nfct_destroy(ct->myct->ct);
+		free(ct->myct);
+		free(ct);
+		return NULL;
+	}
+
+	l3h->l3ct_build(pkt, ct->myct->ct);
+	l4h->l4ct_build(pkt + l3hdr_len, ct->myct->ct);
+
+	return ct;
+}
+
+struct nf_ct_entry *
+ct_find(const uint8_t *pkt, unsigned int l3hdr_len,
+	struct cthelper_proto_l2l3_helper *l3h,
+	struct cthelper_proto_l4_helper *l4h, unsigned int *ctinfo)
+{
+	struct nf_ct_entry *cur;
+
+	list_for_each_entry(cur, &ct_list, head) {
+		if (l3h->l3ct_cmp_orig(pkt, cur->myct->ct) &&
+		    l4h->l4ct_cmp_orig(pkt + l3hdr_len, cur->myct->ct)) {
+			*ctinfo = 0;
+			return cur;
+		}
+		if (l3h->l3ct_cmp_repl(pkt, cur->myct->ct) &&
+		     l4h->l4ct_cmp_repl(pkt + l3hdr_len, cur->myct->ct)) {
+			*ctinfo = IP_CT_IS_REPLY;
+			return cur;
+		}
+	}
+	return NULL;
+}
+
+void ct_add(struct nf_ct_entry *ct)
+{
+	list_add(&ct->head, &ct_list);
+}
+
+void ct_flush(void)
+{
+	struct nf_ct_entry *cur, *tmp;
+
+	list_for_each_entry_safe(cur, tmp, &ct_list, head) {
+		list_del(&cur->head);
+		free(cur->myct->priv_data);
+		free(cur->myct->ct);
+		free(cur->myct);
+		free(cur);
+	}
+}