Adding upstream version 5.7.1.upstream/5.7.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 619 insertions, 0 deletions

diff --git a/lib/utils.h b/lib/utils.h
new file mode 100644
index 0000000..fab13fe
--- /dev/null
+++ b/lib/utils.h
@@ -0,0 +1,619 @@
+/*  Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ *  SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <dirent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/un.h>
+#include <netinet/in.h>
+#include <unistd.h>
+
+#include <gnutls/gnutls.h>
+#include <gnutls/crypto.h>
+
+#include <libknot/libknot.h>
+#include <libknot/packet/pkt.h>
+#include <libknot/rrset.h>
+#include <libknot/rrtype/rrsig.h>
+#include <uv.h>
+
+#include "kresconfig.h"
+#include "contrib/mempattern.h"
+#include "lib/defines.h"
+#include "lib/generic/array.h"
+#include "lib/log.h"
+
+/** When knot_pkt is passed from cache without ->wire, this is the ->size. */
+static const size_t KR_PKT_SIZE_NOWIRE = -1;
+
+/** Maximum length (excluding null-terminator) of a presentation-form address
+ * returned by `kr_straddr`. */
+#define KR_STRADDR_MAXLEN 109
+
+/** Used for reserving enough space for the `kr_sockaddr_key` function
+ * output. */
+struct kr_sockaddr_key_storage {
+	char bytes[sizeof(struct sockaddr_storage)];
+};
+
+
+/*
+ * Logging and debugging.
+ */
+
+/** @brief Callback for request events. */
+typedef void (*trace_callback_f)(struct kr_request *request);
+/**
+ * @brief Callback for request logging handler.
+ * @param[in] msg Log message. Pointer is not valid after handler returns. */
+typedef void (*trace_log_f)(const struct kr_request *request, const char *msg);
+
+/** Assert() but always, regardless of -DNDEBUG.  See also kr_assert(). */
+#define kr_require(expression) do { if (!(expression)) { \
+		kr_fail(true, #expression, __func__, __FILE__, __LINE__); \
+		__builtin_unreachable(); /* aid code analysis */ \
+	} } while (false)
+
+/** Check an assertion that's recoverable. Return the true if it fails and needs handling.
+ *
+ * If the check fails, optionally fork()+abort() to generate coredump
+ * and continue running in parent process.  Return value must be handled to
+ * ensure safe recovery from error.  Use kr_require() for unrecoverable checks.
+ * The errno variable is not mangled, e.g. you can: if (kr_fails_assert(...)) return errno;
+ */
+#define kr_fails_assert(expression) !kr_assert_func((expression), #expression, \
+						   __func__, __FILE__, __LINE__)
+
+/** Kresd assertion without a return value.
+ *
+ * These can be turned on or off, for mandatory unrecoverable checks, use kr_require().
+ * For recoverable checks, use kr_fails_assert().
+ * */
+#define kr_assert(expression) (void)!kr_fails_assert((expression))
+
+/** Whether kr_assert() and kr_fails_assert() checks should abort. */
+KR_EXPORT extern bool kr_dbg_assertion_abort;
+
+/** How often kr_assert() should fork the process before issuing abort (if configured).
+ *
+ * This can be useful for debugging rare edge-cases in production.
+ * if (kr_debug_assertion_abort && kr_debug_assertion_fork), it is
+ * possible to both obtain a coredump (from forked child) and recover from the
+ * non-fatal error in the parent process.
+ *
+ * == 0 (false): no forking
+ * > 0: minimum delay between forks
+ *      (in milliseconds, each instance separately, randomized +-25%)
+ * < 0: no rate-limiting (not recommended)
+ */
+KR_EXPORT extern int kr_dbg_assertion_fork;
+
+/** Use kr_require(), kr_assert() or kr_fails_assert() instead of directly this function. */
+KR_EXPORT KR_COLD void kr_fail(bool is_fatal, const char* expr, const char *func,
+				const char *file, int line);
+
+/** Use kr_require(), kr_assert() or kr_fails_assert() instead of directly this function. */
+__attribute__ ((warn_unused_result))
+static inline bool kr_assert_func(bool result, const char *expr, const char *func,
+				  const char *file, int line)
+{
+	if (!result)
+		kr_fail(false, expr, func, file, line);
+	return result;
+}
+
+#define KR_DNAME_GET_STR(dname_str, dname) \
+	char dname_str[KR_DNAME_STR_MAXLEN]; \
+	knot_dname_to_str(dname_str, (dname), sizeof(dname_str)); \
+	dname_str[sizeof(dname_str) - 1] = 0;
+
+#define KR_RRTYPE_GET_STR(rrtype_str, rrtype) \
+	char rrtype_str[KR_RRTYPE_STR_MAXLEN]; \
+	knot_rrtype_to_string((rrtype), rrtype_str, sizeof(rrtype_str)); \
+	rrtype_str[sizeof(rrtype_str) - 1] = 0;
+
+// Use this for allocations with mm.
+// Use mm_alloc for allocations into mempool
+
+/** A strcmp() variant directly usable for qsort() on an array of strings. */
+static inline int strcmp_p(const void *p1, const void *p2)
+{
+	return strcmp(*(char * const *)p1, *(char * const *)p2);
+}
+
+/** Get current working directory with fallback value. */
+static inline void get_workdir(char *out, size_t len) {
+	if(getcwd(out, len) == NULL) {
+		static const char errprefix[] = "<invalid working directory>";
+		strncpy(out, errprefix, len);
+	}
+}
+
+/** @cond internal Array types */
+struct kr_context;
+
+struct ranked_rr_array_entry {
+	uint32_t qry_uid;
+	uint8_t rank; /**< enum kr_rank */
+	uint8_t revalidation_cnt;
+	bool cached : 1;  /**< Set to true if the entry was written into cache */
+	bool yielded : 1;
+	bool to_wire : 1; /**< whether to be put into the answer */
+	bool expiring : 1; /**< low remaining TTL; see is_expiring; only used in cache ATM */
+	bool in_progress : 1; /**< build of RRset in progress, i.e. different format of RR data */
+	bool dont_cache : 1; /**< avoid caching; useful e.g. for generated data */
+	knot_rrset_t *rr;
+};
+typedef struct ranked_rr_array_entry ranked_rr_array_entry_t;
+
+/** Array of RRsets coming from multiple queries; for struct kr_request.
+ *
+ * Notes:
+ *  - RRSIGs are only considered to form an RRset when the types covered match;
+ *    cache-related code relies on that!
+ *  - RRsets from the same packet (qry_uid) get merged.
+ */
+typedef array_t(ranked_rr_array_entry_t *) ranked_rr_array_t;
+/* @endcond */
+
+typedef struct kr_http_header_array_entry {
+	char* name;
+	char* value;
+} kr_http_header_array_entry_t;
+
+/** Array of HTTP headers for DoH. */
+typedef array_t(kr_http_header_array_entry_t) kr_http_header_array_t;
+
+/** Concatenate N strings. */
+KR_EXPORT
+char* kr_strcatdup(unsigned n, ...);
+
+/** Construct absolute file path, without resolving symlinks.
+ * \return malloc-ed string or NULL (+errno in that case) */
+KR_EXPORT
+char * kr_absolutize_path(const char *dirname, const char *fname);
+
+/** You probably want kr_rand_* convenience functions instead.
+ * This is a buffered version of gnutls_rnd(GNUTLS_RND_NONCE, ..) */
+KR_EXPORT
+void kr_rnd_buffered(void *data, unsigned int size);
+
+/** Return a few random bytes. */
+KR_EXPORT inline
+uint64_t kr_rand_bytes(unsigned int size)
+{
+	uint64_t result;
+	if (size <= 0 || size > sizeof(result)) {
+		kr_log_error(SYSTEM, "kr_rand_bytes(): EINVAL\n");
+		abort();
+	}
+	uint8_t data[sizeof(result)];
+	kr_rnd_buffered(data, size);
+	/* I would have liked to dump the random data into a size_t directly,
+	 * but that would work well only on little-endian machines,
+	 * so instead I hope that the compiler will optimize this out.
+	 * (Tested via reading assembly from usual gcc -O2 setup.)
+	 * Alternatively we could waste more rnd bytes, but that seemed worse. */
+	result = 0;
+	for (unsigned int i = 0; i < size; ++ i) {
+		result |= ((uint64_t)data[i]) << (i * 8);
+	}
+	return result;
+}
+
+/** Throw a pseudo-random coin, succeeding approximately with probability nomin/denomin.
+ * - low precision, only one byte of randomness (or none with extreme parameters)
+ * - tip: use !kr_rand_coin() to get the complementary probability
+ */
+static inline bool kr_rand_coin(unsigned int nomin, unsigned int denomin)
+{
+	/* This function might be called with non-constant values
+	 * so we try to handle odd corner cases instead of crash. */
+	if (nomin >= denomin)
+		return true;
+	else if (nomin <= 0)
+		return false;
+
+	/* threshold = how many parts from 256 are a success */
+	unsigned int threshold = (nomin * 256 + /*rounding*/ denomin / 2) / denomin;
+	if (threshold == 0) threshold = 1;
+	if (threshold == 256) threshold = 255;
+	return (kr_rand_bytes(1) < threshold);
+}
+
+/** Memory reservation routine for knot_mm_t */
+KR_EXPORT
+int kr_memreserve(void *baton, void **mem, size_t elm_size, size_t want, size_t *have);
+
+/** @internal Fast packet reset. */
+KR_EXPORT
+int kr_pkt_recycle(knot_pkt_t *pkt);
+
+/** @internal Clear packet payload. */
+KR_EXPORT
+int kr_pkt_clear_payload(knot_pkt_t *pkt);
+
+/** Construct and put record to packet. */
+KR_EXPORT
+int kr_pkt_put(knot_pkt_t *pkt, const knot_dname_t *name, uint32_t ttl,
+               uint16_t rclass, uint16_t rtype, const uint8_t *rdata, uint16_t rdlen);
+
+/** Set packet header suitable for authoritative answer. (for policy module) */
+KR_EXPORT
+void kr_pkt_make_auth_header(knot_pkt_t *pkt);
+
+/** Get pointer to the in-header QNAME.
+ *
+ * That's normally not lower-cased.  However, when receiving packets from upstream
+ * we xor-apply the secret during packet-parsing, so it would get lower-cased
+ * after that point if the case was right.
+ */
+static inline knot_dname_t * kr_pkt_qname_raw(const knot_pkt_t *pkt)
+{
+	if (pkt == NULL || pkt->qname_size == 0) {
+		return NULL;
+	}
+	return pkt->wire + KNOT_WIRE_HEADER_SIZE;
+}
+
+/** Simple storage for IPx address and their ports or AF_UNSPEC. */
+union kr_sockaddr {
+	struct sockaddr ip;
+	struct sockaddr_in ip4;
+	struct sockaddr_in6 ip6;
+};
+
+/** Simple storage for IPx addresses. */
+union kr_in_addr {
+	struct in_addr ip4;
+	struct in6_addr ip6;
+};
+
+/* TODO: rename kr_inaddr functions to kr_sockaddr */
+/** Address bytes for given family. */
+KR_EXPORT KR_PURE
+const char *kr_inaddr(const struct sockaddr *addr);
+/** Address family. */
+KR_EXPORT KR_PURE
+int kr_inaddr_family(const struct sockaddr *addr);
+/** Address length for given family, i.e. sizeof(struct in*_addr). */
+KR_EXPORT KR_PURE
+int kr_inaddr_len(const struct sockaddr *addr);
+/** Sockaddr length for given family, i.e. sizeof(struct sockaddr_in*). */
+KR_EXPORT KR_PURE
+int kr_sockaddr_len(const struct sockaddr *addr);
+
+/** Creates a packed structure from the specified `addr`, safe for use as a key
+ * in containers like `trie_t`, and writes it into `dst`. On success, returns
+ * the actual length of the key.
+ *
+ * Returns `kr_error(EAFNOSUPPORT)` if the family of `addr` is unsupported. */
+KR_EXPORT
+ssize_t kr_sockaddr_key(struct kr_sockaddr_key_storage *dst,
+                        const struct sockaddr *addr);
+
+/** Creates a `struct sockaddr` from the specified `key` created using the
+ * `kr_sockaddr_key()` function. */
+KR_EXPORT
+struct sockaddr *kr_sockaddr_from_key(struct sockaddr_storage *dst,
+                                      const char *key);
+
+/** Checks whether the two keys represent the same address;
+ * does NOT compare the ports. */
+KR_EXPORT
+bool kr_sockaddr_key_same_addr(const char *key_a, const char *key_b);
+
+/** Compare two given sockaddr.
+ * return 0 - addresses are equal, error code otherwise.
+ */
+KR_EXPORT KR_PURE
+int kr_sockaddr_cmp(const struct sockaddr *left, const struct sockaddr *right);
+/** Port. */
+KR_EXPORT KR_PURE
+uint16_t kr_inaddr_port(const struct sockaddr *addr);
+/** Set port. */
+KR_EXPORT
+void kr_inaddr_set_port(struct sockaddr *addr, uint16_t port);
+
+/** Write string representation for given address as "<addr>#<port>".
+ * \param[in]     addr   the raw address
+ * \param[out]    buf    the buffer for output string
+ * \param[in,out] buflen the available(in) and utilized(out) length, including \0 */
+KR_EXPORT
+int kr_inaddr_str(const struct sockaddr *addr, char *buf, size_t *buflen);
+
+/** Write string representation for given address as "<addr>#<port>".
+ * It's the same as kr_inaddr_str(), but the input address is input in native format
+ * like for inet_ntop() (4 or 16 bytes) and port must be separate parameter.  */
+KR_EXPORT
+int kr_ntop_str(int family, const void *src, uint16_t port, char *buf, size_t *buflen);
+
+/** @internal Create string representation addr#port.
+ *  @return pointer to a *static* string, i.e. each call will overwrite it
+ */
+KR_EXPORT
+char *kr_straddr(const struct sockaddr *addr);
+
+/** Return address type for string. */
+KR_EXPORT KR_PURE
+int kr_straddr_family(const char *addr);
+/** Return address length in given family (struct in*_addr). */
+KR_EXPORT KR_CONST
+int kr_family_len(int family);
+
+/** Create a sockaddr* from string+port representation.
+ * Also accepts IPv6 link-local and AF_UNIX starting with "/" (ignoring port) */
+KR_EXPORT
+struct sockaddr * kr_straddr_socket(const char *addr, int port, knot_mm_t *pool);
+
+/** Parse address and return subnet length (bits).
+  * @warning 'dst' must be at least `sizeof(struct in6_addr)` long. */
+KR_EXPORT
+int kr_straddr_subnet(void *dst, const char *addr);
+
+/** Splits ip address specified as "addr@port" or "addr#port" into addr and port.
+ * \param[in]  instr zero-terminated input, e.g. "192.0.2.1#12345\0"
+ * \param[out] ipaddr working buffer for the port-less prefix of instr;
+ *                    length >= INET6_ADDRSTRLEN + 1.
+ * \param[out] port written in case it's specified in instr
+ * \return error code
+ * \note Typically you follow this by kr_straddr_socket().
+ * \note Only internet addresses are supported, i.e. no AF_UNIX sockets.
+ */
+KR_EXPORT
+int kr_straddr_split(const char *instr, char ipaddr[static restrict (INET6_ADDRSTRLEN + 1)],
+		     uint16_t *port);
+
+/** Formats ip address and port in "addr#port" format.
+  * and performs validation.
+  * @note Port always formatted as five-character string with leading zeros.
+  * @return kr_error(EINVAL) - addr or buf is NULL or buflen is 0 or
+  *                            addr doesn't contain a valid ip address
+  *         kr_error(ENOSP)  - buflen is too small
+  */
+KR_EXPORT
+int kr_straddr_join(const char *addr, uint16_t port, char *buf, size_t *buflen);
+
+/** Compare memory bitwise.  The semantics is "the same" as for memcmp().
+ *  The partial byte is considered with more-significant bits first,
+ *  so this is e.g. suitable for comparing IP prefixes. */
+KR_EXPORT KR_PURE
+int kr_bitcmp(const char *a, const char *b, int bits);
+
+/** Masks bits. The specified number of bits in `a` from the left (network order)
+ * will remain their original value, while the rest will be set to zero.
+ * This is useful for storing network addresses in a trie. */
+KR_EXPORT
+void kr_bitmask(unsigned char *a, size_t a_len, int bits);
+
+/** Check whether `addr` points to an `AF_INET6` address and whether the address
+ * is link-local. */
+static inline bool kr_sockaddr_link_local(const struct sockaddr *addr)
+{
+	if (addr->sa_family != AF_INET6)
+		return false;
+
+	/* Link-local: https://tools.ietf.org/html/rfc4291#section-2.4 */
+	const uint8_t prefix[] = { 0xFE, 0x80 };
+	const struct sockaddr_in6 *ip6 = (const struct sockaddr_in6 *) addr;
+	return kr_bitcmp((char *) ip6->sin6_addr.s6_addr, (char *) prefix, 10) == 0;
+}
+
+/* Stash key = {[5] class, [1-255] owner, [5] type, [5] additional, [1] \x00 } */
+#define KR_RRKEY_LEN (16 + KNOT_DNAME_MAXLEN)
+/** Create unique null-terminated string key for RR.
+  * @param key Destination buffer for key size, MUST be KR_RRKEY_LEN or larger.
+  * @param class RR class.
+  * @param owner RR owner name.
+  * @param type RR type.
+  * @param additional flags (for instance can be used for storing covered type
+  *	   when RR type is RRSIG).
+  * @return key length if successful or an error
+  * */
+KR_EXPORT
+int kr_rrkey(char *key, uint16_t class, const knot_dname_t *owner,
+	     uint16_t type, uint16_t additional);
+
+/** Add RRSet copy to a ranked RR array.
+ *
+ * To convert to standard RRs inside, you need to call _finalize() afterwards,
+ * and the memory of rr->rrs.rdata has to remain until then.
+ *
+ * \return array index (>= 0) or error code (< 0)
+ */
+KR_EXPORT
+int kr_ranked_rrarray_add(ranked_rr_array_t *array, const knot_rrset_t *rr,
+			  uint8_t rank, bool to_wire, uint32_t qry_uid, knot_mm_t *pool);
+/** Finalize in_progress sets - all with matching qry_uid. */
+KR_EXPORT
+int kr_ranked_rrarray_finalize(ranked_rr_array_t *array, uint32_t qry_uid, knot_mm_t *pool);
+
+/** @internal Mark the RRSets from particular query as
+ * "have (not) to be recorded in the final answer".
+ * @param array RRSet array.
+ * @param to_wire Records must be\must not be recorded in final answer.
+ * @param qry_uid Query uid.
+ * @param check_dups When to_wire is true, try to avoid duplicate RRSets.
+ * @param extraCheck optional function checking whether to consider the record
+ * @return 0 or an error
+ */
+int kr_ranked_rrarray_set_wire(ranked_rr_array_t *array, bool to_wire,
+			       uint32_t qry_uid, bool check_dups,
+			       bool (*extraCheck)(const ranked_rr_array_entry_t *));
+
+
+/** Style used by the kr_*_text() functions. */
+KR_EXPORT extern
+const knot_dump_style_t KR_DUMP_STYLE_DEFAULT;
+
+/**
+ * @return Newly allocated string representation of packet.
+ * Caller has to free() returned string.
+ */
+KR_EXPORT
+char *kr_pkt_text(const knot_pkt_t *pkt);
+
+KR_PURE
+char *kr_rrset_text(const knot_rrset_t *rr);
+
+KR_PURE
+static inline char *kr_dname_text(const knot_dname_t *name) {
+	return knot_dname_to_str_alloc(name);
+}
+
+KR_CONST
+static inline char *kr_rrtype_text(const uint16_t rrtype) {
+	char type_str[32] = {0};
+	knot_rrtype_to_string(rrtype, type_str, sizeof(type_str));
+	return strdup(type_str);
+}
+
+/**
+ * Call module property.
+ */
+KR_EXPORT
+char *kr_module_call(struct kr_context *ctx, const char *module, const char *prop, const char *input);
+
+/** Swap two places.  Note: the parameters need to be without side effects. */
+#define SWAP(x, y) do { /* http://stackoverflow.com/a/3982430/587396 */ \
+	unsigned char swap_temp[sizeof(x) == sizeof(y) ? (ssize_t)sizeof(x) : -1]; \
+	memcpy(swap_temp, &y, sizeof(x)); \
+	memcpy(&y,        &x, sizeof(x)); \
+	memcpy(&x, swap_temp, sizeof(x)); \
+	} while(0)
+
+/** Return the (covered) type of an nonempty RRset. */
+static inline uint16_t kr_rrset_type_maysig(const knot_rrset_t *rr)
+{
+	kr_require(rr && rr->rrs.count && rr->rrs.rdata);
+	uint16_t type = rr->type;
+	if (type == KNOT_RRTYPE_RRSIG)
+		type = knot_rrsig_type_covered(rr->rrs.rdata);
+	return type;
+}
+
+/** The current time in monotonic milliseconds.
+ *
+ * \note it may be outdated in case of long callbacks; see uv_now().
+ */
+KR_EXPORT
+uint64_t kr_now(void);
+
+/** Call free(handle->data); it's useful e.g. as a callback in uv_close(). */
+KR_EXPORT void kr_uv_free_cb(uv_handle_t* handle);
+
+/** Convert name from lookup format to wire.  See knot_dname_lf
+ *
+ * \note len bytes are read and len+1 are written with *normal* LF,
+ * 	 but it's also allowed that the final zero byte is omitted in LF.
+ * \return the number of bytes written (>0) or error code (<0)
+ */
+int knot_dname_lf2wire(knot_dname_t *dst, uint8_t len, const uint8_t *lf);
+
+/** Patched knot_dname_lf.  LF for "." has length zero instead of one, for consistency.
+ * (TODO: consistency?)
+ * \param add_wildcard append the wildcard label
+ * \note packet is always NULL
+ */
+static inline int kr_dname_lf(uint8_t *dst, const knot_dname_t *src, bool add_wildcard)
+{
+	knot_dname_storage_t right_aligned_dst;
+	uint8_t *right_aligned_dname_start = knot_dname_lf(src, right_aligned_dst);
+	if (!right_aligned_dname_start) {
+		return kr_error(EINVAL);
+	}
+	int len = right_aligned_dname_start[0];
+	if (kr_fails_assert(right_aligned_dname_start + 1 + len - KNOT_DNAME_MAXLEN == right_aligned_dst))
+		return kr_error(EINVAL);
+	memcpy(dst + 1, right_aligned_dname_start + 1, len);
+	if (add_wildcard) {
+		if (len + 2 > KNOT_DNAME_MAXLEN)
+			return kr_error(ENOSPC);
+		dst[len + 1] = '*';
+		dst[len + 2] = '\0';
+		len += 2;
+	}
+	dst[0] = len;
+	return KNOT_EOK;
+}
+
+
+/** Timer, i.e stop-watch. */
+typedef struct timespec kr_timer_t;
+
+/** Start, i.e. set the reference point. */
+static inline void kr_timer_start(kr_timer_t *start)
+{
+	/* The call should be very reliable, but let's check it in _start() at least. */
+	kr_require(start && clock_gettime(CLOCK_MONOTONIC, start) == 0);
+}
+
+/** Get elapsed time in floating-point seconds. */
+static inline double kr_timer_elapsed(kr_timer_t *start)
+{
+	kr_require(start);
+	kr_timer_t end = { 0 };
+	(void)clock_gettime(CLOCK_MONOTONIC, &end);
+	return (end.tv_sec - start->tv_sec) + (double)(end.tv_nsec - start->tv_nsec) / 1e9;
+}
+
+/** Get elapsed time in micro-seconds. */
+static inline uint64_t kr_timer_elapsed_us(kr_timer_t *start)
+{
+	kr_require(start);
+	kr_timer_t end = { 0 };
+	(void)clock_gettime(CLOCK_MONOTONIC, &end);
+	// avoid negative differences, because of integer division
+	if (end.tv_nsec - start->tv_nsec < 0) {
+		end.tv_nsec += 1000*1000*1000;
+		end.tv_sec  -= 1;
+	}
+	return (uint64_t)(end.tv_sec - start->tv_sec) * 1000000
+		// adding 500 gives us rounding
+		+ (end.tv_nsec - start->tv_nsec + 500) / 1000;
+}
+
+
+/**
+ * Difference between two calendar times specified as strings.
+ * \param[in]  format format for strptime
+ * \param[out] diff result from C difftime(time1, time0)
+ */
+KR_EXPORT
+const char *kr_strptime_diff(const char *format, const char *time1_str,
+		             const char *time0_str, double *diff);
+
+/* Trivial non-inline wrappers, to be used in lua. */
+KR_EXPORT void kr_rrset_init(knot_rrset_t *rrset, knot_dname_t *owner,
+				uint16_t type, uint16_t rclass, uint32_t ttl);
+KR_EXPORT bool kr_pkt_has_wire(const knot_pkt_t *pkt);
+KR_EXPORT bool kr_pkt_has_dnssec(const knot_pkt_t *pkt);
+KR_EXPORT uint16_t kr_pkt_qclass(const knot_pkt_t *pkt);
+KR_EXPORT uint16_t kr_pkt_qtype(const knot_pkt_t *pkt);
+KR_EXPORT uint32_t kr_rrsig_sig_inception(const knot_rdata_t *rdata);
+KR_EXPORT uint32_t kr_rrsig_sig_expiration(const knot_rdata_t *rdata);
+KR_EXPORT uint16_t kr_rrsig_type_covered(const knot_rdata_t *rdata);
+
+KR_EXPORT time_t kr_file_mtime (const char* fname);
+/** Return filesystem size in bytes. */
+KR_EXPORT long long kr_fssize(const char *path);
+/** Simply return de->dname. (useful from Lua) */
+KR_EXPORT const char * kr_dirent_name(const struct dirent *de);
+
+
+/* trivial libknot versions compatibility */
+static inline size_t kr_dname_prefixlen(const uint8_t *name, unsigned nlabels)
+{
+	return knot_dname_prefixlen(name, nlabels
+		#if KNOT_VERSION_HEX < 0x030400
+			, NULL
+		#endif
+	);
+}
+