/*  Copyright (C) 2016-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#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);
	if (cached) {
		memcpy(cached->opt_data, opt, opt_size);
	}

	return kr_ok();
}
