/* Copyright (C) CZ.NIC, z.s.p.o. * SPDX-License-Identifier: GPL-3.0-or-later */ #pragma once #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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[] = ""; 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 "#". * \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 "#". * 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(); /** 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);