1 files changed, 58 insertions, 0 deletions
diff --git a/lib/cookies/lru_cache.c b/lib/cookies/lru_cache.c
new file mode 100644
index 0000000..245d1c3
--- /dev/null
+++ b/lib/cookies/lru_cache.c
@@ -0,0 +1,58 @@
+/*  Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ *  SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include <libknot/rrtype/opt.h>
+#include <string.h>
+
+#include "lib/cookies/lru_cache.h"
+#include "lib/utils.h"
+
+const uint8_t *kr_cookie_lru_get(kr_cookie_lru_t *cache,
+                                 const struct sockaddr *sa)
+{
+	if (!cache || !sa) {
+		return NULL;
+	}
+
+	int addr_len = kr_inaddr_len(sa);
+	const char *addr = kr_inaddr(sa);
+	if (!addr || addr_len <= 0) {
+		return NULL;
+	}
+
+	struct cookie_opt_data *cached = lru_get_try(cache, addr, addr_len);
+	return cached ? cached->opt_data : NULL;
+}
+
+int kr_cookie_lru_set(kr_cookie_lru_t *cache, const struct sockaddr *sa,
+                      uint8_t *opt)
+{
+	if (!cache || !sa) {
+		return kr_error(EINVAL);
+	}
+
+	if (!opt) {
+		return kr_ok();
+	}
+
+	int addr_len = kr_inaddr_len(sa);
+	const char *addr = kr_inaddr(sa);
+	if (!addr || addr_len <= 0) {
+		return kr_error(EINVAL);
+	}
+
+	uint16_t opt_size = KNOT_EDNS_OPTION_HDRLEN +
+	                    knot_edns_opt_get_length(opt);
+
+	if (opt_size > KR_COOKIE_OPT_MAX_LEN) {
+		return kr_error(EINVAL);
+	}
+
+	struct cookie_opt_data *cached = lru_get_new(cache, addr, addr_len, NULL);
+	if (cached) {
+		memcpy(cached->opt_data, opt, opt_size);
+	}
+
+	return kr_ok();
+}