From 830407e88f9d40d954356c3754f2647f91d5c06a Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 17:26:00 +0200 Subject: Adding upstream version 5.6.0. Signed-off-by: Daniel Baumann --- lib/layer.h | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 lib/layer.h (limited to 'lib/layer.h') diff --git a/lib/layer.h b/lib/layer.h new file mode 100644 index 0000000..7721560 --- /dev/null +++ b/lib/layer.h @@ -0,0 +1,107 @@ +/* Copyright (C) CZ.NIC, z.s.p.o. + * SPDX-License-Identifier: GPL-3.0-or-later + */ + +#pragma once + +#include "kresconfig.h" +#include "lib/defines.h" +#include "lib/utils.h" + +/** Layer processing states. Only one value at a time (but see TODO). + * + * Each state represents the state machine transition, + * and determines readiness for the next action. + * See struct kr_layer_api for the actions. + * + * TODO: the cookie module sometimes sets (_FAIL | _DONE) on purpose (!) + */ +enum kr_layer_state { + KR_STATE_CONSUME = 1 << 0, /*!< Consume data. */ + KR_STATE_PRODUCE = 1 << 1, /*!< Produce data. */ + + /*! Finished successfully or a special case: in CONSUME phase this can + * be used (by iterator) to do a transition to PRODUCE phase again, + * in which case the packet wasn't accepted for some reason. */ + KR_STATE_DONE = 1 << 2, + + KR_STATE_FAIL = 1 << 3, /*!< Error. */ + KR_STATE_YIELD = 1 << 4, /*!< Paused, waiting for a sub-query. */ +}; + +/** Check that a kr_layer_state makes sense. We're not very strict ATM. */ +static inline bool kr_state_consistent(enum kr_layer_state s) +{ +#ifdef __clang__ +#pragma clang diagnostic push +#pragma clang diagnostic ignored "-Wtautological-constant-out-of-range-compare" +#pragma clang diagnostic ignored "-Wtautological-unsigned-enum-zero-compare" +#endif + return s >= 0 && s < (1 << 5); +#ifdef __clang__ +#pragma clang diagnostic pop +#endif +} + +/* Forward declarations. */ +struct kr_layer_api; + +/** Packet processing context. */ +typedef struct kr_layer { + int state; /*!< The current state; bitmap of enum kr_layer_state. */ + struct kr_request *req; /*!< The corresponding request. */ + const struct kr_layer_api *api; + knot_pkt_t *pkt; /*!< In glue for lua kr_layer_api it's used to pass the parameter. */ + struct sockaddr *dst; /*!< In glue for checkout layer it's used to pass the parameter. */ + bool is_stream; /*!< In glue for checkout layer it's used to pass the parameter. */ +} kr_layer_t; + +/** Packet processing module API. All functions return the new kr_layer_state. + * + * Lua modules are allowed to return nil/nothing, meaning the state shall not change. + */ +struct kr_layer_api { + /** Start of processing the DNS request. */ + int (*begin)(kr_layer_t *ctx); + + int (*reset)(kr_layer_t *ctx); + + /** Paired to begin, called both on successes and failures. */ + int (*finish)(kr_layer_t *ctx); + + /** Process an answer from upstream or from cache. + * Lua API: call is omitted iff (state & KR_STATE_FAIL). */ + int (*consume)(kr_layer_t *ctx, knot_pkt_t *pkt); + + /** Produce either an answer to the request or a query for upstream (or fail). + * Lua API: call is omitted iff (state & KR_STATE_FAIL). */ + int (*produce)(kr_layer_t *ctx, knot_pkt_t *pkt); + + /** Finalises the outbound query packet with the knowledge of the IP addresses. + * The checkout layer doesn't persist the state, so canceled subrequests + * don't affect the resolution or rest of the processing. + * Lua API: call is omitted iff (state & KR_STATE_FAIL). */ + int (*checkout)(kr_layer_t *ctx, knot_pkt_t *packet, struct sockaddr *dst, int type); + + /** Finalises the answer. + * Last chance to affect what will get into the answer, including EDNS. + * Not called if the packet is being dropped. */ + int (*answer_finalize)(kr_layer_t *ctx); + + /** The C module can store anything in here. */ + void *data; + + /** Internal to ./daemon/ffimodule.c. */ + int cb_slots[]; +}; + +typedef struct kr_layer_api kr_layer_api_t; + +/** Pickled layer state (api, input, state). */ +struct kr_layer_pickle { + struct kr_layer_pickle *next; + const struct kr_layer_api *api; + knot_pkt_t *pkt; + unsigned state; +}; + -- cgit v1.2.3