1 files changed, 74 insertions, 0 deletions
diff --git a/lib/cookies/helper.h b/lib/cookies/helper.h
new file mode 100644
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--- /dev/null
+++ b/lib/cookies/helper.h
@@ -0,0 +1,74 @@
+/*  Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ *  SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <libknot/packet/pkt.h>
+
+#include "lib/cookies/alg_containers.h"
+#include "lib/cookies/control.h"
+#include "lib/cookies/lru_cache.h"
+#include "lib/cookies/nonce.h"
+#include "lib/defines.h"
+#include "lib/resolve.h"
+
+/**
+ * @brief Updates DNS cookie in the request EDNS options.
+ * @note This function must be called before the request packet is finalised.
+ * @param clnt_comp    client cookie control structure
+ * @param cookie_cache cookie cache
+ * @param clnt_sa      client socket address
+ * @param srvr_sa      server socket address
+ * @param req          name resolution request
+ * @return kr_ok() or error code
+ */
+KR_EXPORT
+int kr_request_put_cookie(const struct kr_cookie_comp *clnt_comp,
+                          kr_cookie_lru_t *cookie_cache,
+                          const struct sockaddr *clnt_sa,
+                          const struct sockaddr *srvr_sa,
+                          struct kr_request *req);
+
+/**
+ * @brief Inserts a cookie option into the OPT RR. It does not write any
+ *        wire data.
+ * @note The content of @a sc_input is modified. Any pre-set nonce value is
+ *       ignored. After retuning its nonce value will be null.
+ * @param sc_input  data needed to compute server cookie, nonce is ignored
+ * @param nonce     nonce value that is actually used
+ * @param alg       hash algorithm
+ * @param pkt       DNS response packet
+ */
+KR_EXPORT
+int kr_answer_write_cookie(struct knot_sc_input *sc_input,
+                           const struct kr_nonce_input *nonce,
+                           const struct knot_sc_alg *alg, knot_pkt_t *pkt);
+
+/**
+ * @brief Set RCODE and extended RCODE.
+ * @param pkt DNS packet
+ * @param whole_rcode RCODE value
+ * @return kr_ok() or error code
+ */
+KR_EXPORT
+int kr_pkt_set_ext_rcode(knot_pkt_t *pkt, uint16_t whole_rcode);
+
+/**
+ * @brief Check whether packet is a server cookie request according to
+ *        RFC7873 5.4.
+ * @param pkt Packet to be examined.
+ * @return Pointer to entire cookie option if is a server cookie query, NULL on
+ *         errors or if packet doesn't contain cookies or if QDCOUNT > 0.
+ */
+KR_EXPORT
+uint8_t *kr_no_question_cookie_query(const knot_pkt_t *pkt);
+
+/**
+ * @brief Parse cookies from cookie option.
+ * @param cookie_opt Cookie option.
+ * @param cookies    Cookie structure to be set.
+ * @return kr_ok() on success, error if cookies are malformed.
+ */
+KR_EXPORT
+int kr_parse_cookie_opt(uint8_t *cookie_opt, struct knot_dns_cookies *cookies);