/* Copyright (C) CZ.NIC, z.s.p.o. * SPDX-License-Identifier: GPL-3.0-or-later */ #pragma once #include #include #include #include "lib/selection.h" #include "lib/zonecut.h" /** Query flags */ struct kr_qflags { bool NO_MINIMIZE : 1; /**< Don't minimize QNAME. */ bool NO_IPV6 : 1; /**< Disable IPv6 */ bool NO_IPV4 : 1; /**< Disable IPv4 */ bool TCP : 1; /**< Use TCP (or TLS) for this query. */ bool NO_ANSWER : 1; /**< Do not send any answer to the client. * Request state should be set to `KR_STATE_FAIL` * when this flag is set. */ bool RESOLVED : 1; /**< Query is resolved. Note that kr_query gets * RESOLVED before following a CNAME chain; see .CNAME. */ bool AWAIT_IPV4 : 1; /**< Query is waiting for A address. */ bool AWAIT_IPV6 : 1; /**< Query is waiting for AAAA address. */ bool AWAIT_CUT : 1; /**< Query is waiting for zone cut lookup */ bool NO_EDNS : 1; /**< Don't use EDNS. */ bool CACHED : 1; /**< Query response is cached. */ bool NO_CACHE : 1; /**< No cache for lookup; exception: finding NSs and subqueries. */ bool EXPIRING : 1; /**< Query response is cached but expiring. See is_expiring(). */ bool ALLOW_LOCAL : 1; /**< Allow queries to local or private address ranges. */ bool DNSSEC_WANT : 1; /**< Want DNSSEC secured answer; exception: +cd, * i.e. knot_wire_get_cd(request->qsource.packet->wire) */ bool DNSSEC_BOGUS : 1; /**< Query response is DNSSEC bogus. */ bool DNSSEC_INSECURE : 1;/**< Query response is DNSSEC insecure. */ bool DNSSEC_CD : 1; /**< Instruction to set CD bit in request. */ bool STUB : 1; /**< Stub resolution, accept received answer as solved. */ bool ALWAYS_CUT : 1; /**< Always recover zone cut (even if cached). */ bool DNSSEC_WEXPAND : 1; /**< Query response has wildcard expansion. */ bool PERMISSIVE : 1; /**< Permissive resolver mode. */ bool STRICT : 1; /**< Strict resolver mode. */ bool BADCOOKIE_AGAIN : 1;/**< Query again because bad cookie returned. */ bool CNAME : 1; /**< Query response contains CNAME in answer section. */ bool REORDER_RR : 1; /**< Reorder cached RRs. */ bool TRACE : 1; /**< Also log answers on debug level. */ bool NO_0X20 : 1; /**< Disable query case randomization . */ bool DNSSEC_NODS : 1; /**< DS non-existence is proven */ bool DNSSEC_OPTOUT : 1; /**< Closest encloser proof has optout */ bool NONAUTH : 1; /**< Non-authoritative in-bailiwick records are enough. * TODO: utilize this also outside cache. */ bool FORWARD : 1; /**< Forward all queries to upstream; validate answers. */ bool DNS64_MARK : 1; /**< Internal mark for dns64 module. */ bool CACHE_TRIED : 1; /**< Internal to cache module. */ bool NO_NS_FOUND : 1; /**< No valid NS found during last PRODUCE stage. */ bool PKT_IS_SANE : 1; /**< Set by iterator in consume phase to indicate whether * some basic aspects of the packet are OK, e.g. QNAME. */ bool DNS64_DISABLE : 1; /**< Don't do any DNS64 stuff (meant for view:addr). */ }; /** Combine flags together. This means set union for simple flags. */ KR_EXPORT void kr_qflags_set(struct kr_qflags *fl1, struct kr_qflags fl2); /** Remove flags. This means set-theoretic difference. */ KR_EXPORT void kr_qflags_clear(struct kr_qflags *fl1, struct kr_qflags fl2); /** Callback for serve-stale decisions. * @param ttl the expired TTL (i.e. it's < 0) * @return the adjusted TTL (typically 1) or < 0. */ typedef int32_t (*kr_stale_cb)(int32_t ttl, const knot_dname_t *owner, uint16_t type, const struct kr_query *qry); /** * Single query representation. */ struct kr_query { struct kr_query *parent; knot_dname_t *sname; /**< The name to resolve - lower-cased, uncompressed. */ uint16_t stype; uint16_t sclass; uint16_t id; uint16_t reorder; /**< Seed to reorder (cached) RRs in answer or zero. */ struct kr_qflags flags; struct kr_qflags forward_flags; uint32_t secret; uint32_t uid; /**< Query iteration number, unique within the kr_rplan. */ uint64_t creation_time_mono; /* The time of query's creation (milliseconds). * Or time of creation of an oldest * ancestor if it is a subquery. */ uint64_t timestamp_mono; /**< Time of query created or time of * query to upstream resolver (milliseconds). */ struct timeval timestamp; /**< Real time for TTL+DNSSEC checks (.tv_sec only). */ struct kr_zonecut zone_cut; struct kr_layer_pickle *deferred; /** Current xNAME depth, set by iterator. 0 = uninitialized, 1 = no CNAME, ... * See also KR_CNAME_CHAIN_LIMIT. */ int8_t cname_depth; /** Pointer to the query that originated this one because of following a CNAME (or NULL). */ struct kr_query *cname_parent; struct kr_request *request; /**< Parent resolution request. */ kr_stale_cb stale_cb; /**< See the type */ struct kr_server_selection server_selection; }; /** @cond internal Array of queries. */ typedef array_t(struct kr_query *) kr_qarray_t; /* @endcond */ /** * Query resolution plan structure. * * The structure most importantly holds the original query, answer and the * list of pending queries required to resolve the original query. * It also keeps a notion of current zone cut. */ struct kr_rplan { kr_qarray_t pending; /**< List of pending queries. Beware: order is significant ATM, as the last is the next one to solve, and they may be inter-dependent. */ kr_qarray_t resolved; /**< List of resolved queries. */ struct kr_query *initial; /**< The initial query (also in pending or resolved). */ struct kr_request *request; /**< Parent resolution request. */ knot_mm_t *pool; /**< Temporary memory pool. */ uint32_t next_uid; /**< Next value for kr_query::uid (incremental). */ }; /** * Initialize resolution plan (empty). * @param rplan plan instance * @param request resolution request * @param pool ephemeral memory pool for whole resolution */ KR_EXPORT int kr_rplan_init(struct kr_rplan *rplan, struct kr_request *request, knot_mm_t *pool); /** * Deinitialize resolution plan, aborting any uncommitted transactions. * @param rplan plan instance */ KR_EXPORT void kr_rplan_deinit(struct kr_rplan *rplan); /** * Return true if the resolution plan is empty (i.e. finished or initialized) * @param rplan plan instance * @return true or false */ KR_EXPORT KR_PURE bool kr_rplan_empty(struct kr_rplan *rplan); /** * Push empty query to the top of the resolution plan. * @note This query serves as a cookie query only. * @param rplan plan instance * @param parent query parent (or NULL) * @return query instance or NULL */ KR_EXPORT struct kr_query *kr_rplan_push_empty(struct kr_rplan *rplan, struct kr_query *parent); /** * Push a query to the top of the resolution plan. * @note This means that this query takes precedence before all pending queries. * @param rplan plan instance * @param parent query parent (or NULL) * @param name resolved name * @param cls resolved class * @param type resolved type * @return query instance or NULL */ KR_EXPORT struct kr_query *kr_rplan_push(struct kr_rplan *rplan, struct kr_query *parent, const knot_dname_t *name, uint16_t cls, uint16_t type); /** * Pop existing query from the resolution plan. * @note Popped queries are not discarded, but moved to the resolved list. * @param rplan plan instance * @param qry resolved query * @return 0 or an error */ KR_EXPORT int kr_rplan_pop(struct kr_rplan *rplan, struct kr_query *qry); /** * Return true if resolution chain satisfies given query. */ KR_EXPORT KR_PURE bool kr_rplan_satisfies(struct kr_query *closure, const knot_dname_t *name, uint16_t cls, uint16_t type); /** Return last resolved query. */ KR_EXPORT KR_PURE struct kr_query *kr_rplan_resolved(struct kr_rplan *rplan); /** * Return last query (either currently being solved or last resolved). * This is necessary to retrieve the last query in case of resolution failures (e.g. time limit reached). */ KR_EXPORT KR_PURE struct kr_query *kr_rplan_last(struct kr_rplan *rplan); /** * Check if a given query already resolved. * @param rplan plan instance * @param parent query parent (or NULL) * @param name resolved name * @param cls resolved class * @param type resolved type * @return query instance or NULL */ KR_EXPORT KR_PURE struct kr_query *kr_rplan_find_resolved(struct kr_rplan *rplan, struct kr_query *parent, const knot_dname_t *name, uint16_t cls, uint16_t type);