/* * Copyright (c) 2020 Nordic Semiconductor ASA * * SPDX-License-Identifier: Apache-2.0 */ #ifndef ZCBOR_ENCODE_H__ #define ZCBOR_ENCODE_H__ #include #include #include #include "zcbor_common.h" #ifdef __cplusplus extern "C" { #endif /** The zcbor_encode library provides functions for encoding CBOR data elements. * * See The README for an introduction to CBOR, including the meaning of pint, * nint, bstr etc. */ /** See @ref zcbor_new_state() */ void zcbor_new_encode_state(zcbor_state_t *state_array, size_t n_states, uint8_t *payload, size_t payload_len, size_t elem_count); /** Convenience macro for declaring and initializing an encoding state with backups. * * This gives you a state variable named @p name. The variable functions like * a pointer. * * @param[in] name The name of the new state variable. * @param[in] num_backups The number of backup slots to keep in the state. * @param[in] payload The payload to work on. * @param[in] payload_size The size (in bytes) of @p payload. * @param[in] elem_count The starting elem_count (typically 1). */ #define ZCBOR_STATE_E(name, num_backups, payload, payload_size, elem_count) \ zcbor_state_t name[((num_backups) + 2)]; \ do { \ zcbor_new_encode_state(name, ZCBOR_ARRAY_SIZE(name), payload, payload_size, elem_count); \ } while(0) /** The following applies to all _put and _encode functions listed directly below. * * The difference between _put and _encode is only in the argument type, * but when a @ref zcbor_encoder_t is needed, such as for @ref zcbor_multi_encode, * the _encode variant must be used. * * @param[inout] state The current state of the encoding. * @param[in] input The value to encode. * * @retval true Everything is ok. * @retval false If the payload is exhausted. Or an unexpected error happened. * Use zcbor_peek_error() to see the error code. */ bool zcbor_int32_put(zcbor_state_t *state, int32_t input); /* pint/nint */ bool zcbor_int64_put(zcbor_state_t *state, int64_t input); /* pint/nint */ bool zcbor_uint32_put(zcbor_state_t *state, uint32_t input); /* pint */ bool zcbor_uint64_put(zcbor_state_t *state, uint64_t input); /* pint */ bool zcbor_size_put(zcbor_state_t *state, size_t input); /* pint */ bool zcbor_tag_put(zcbor_state_t *state, uint32_t tag); /* CBOR tag */ bool zcbor_simple_put(zcbor_state_t *state, uint8_t input); /* CBOR simple value */ bool zcbor_bool_put(zcbor_state_t *state, bool input); /* boolean CBOR simple value */ bool zcbor_nil_put(zcbor_state_t *state, const void *unused); /* 'nil' CBOR simple value */ bool zcbor_undefined_put(zcbor_state_t *state, const void *unused); /* 'undefined' CBOR simple value */ bool zcbor_float16_put(zcbor_state_t *state, float input); /* IEEE754 float16 */ bool zcbor_float16_bytes_put(zcbor_state_t *state, uint16_t input); /* IEEE754 float16 raw bytes */ bool zcbor_float32_put(zcbor_state_t *state, float input); /* IEEE754 float32 */ bool zcbor_float64_put(zcbor_state_t *state, double input); /* IEEE754 float64 */ bool zcbor_int32_encode(zcbor_state_t *state, const int32_t *input); /* pint/nint */ bool zcbor_int64_encode(zcbor_state_t *state, const int64_t *input); /* pint/nint */ bool zcbor_uint32_encode(zcbor_state_t *state, const uint32_t *input); /* pint */ bool zcbor_uint64_encode(zcbor_state_t *state, const uint64_t *input); /* pint */ bool zcbor_size_encode(zcbor_state_t *state, const size_t *input); /* pint */ bool zcbor_int_encode(zcbor_state_t *state, const void *input_int, size_t int_size); bool zcbor_uint_encode(zcbor_state_t *state, const void *input_uint, size_t uint_size); bool zcbor_bstr_encode(zcbor_state_t *state, const struct zcbor_string *input); /* bstr */ bool zcbor_tstr_encode(zcbor_state_t *state, const struct zcbor_string *input); /* tstr */ bool zcbor_tag_encode(zcbor_state_t *state, uint32_t *tag); /* CBOR tag. Note that zcbor_tag_encode()'s argument was changed to be a pointer. See also zcbor_tag_put(). */ bool zcbor_simple_encode(zcbor_state_t *state, uint8_t *input); /* CBOR simple value */ bool zcbor_bool_encode(zcbor_state_t *state, const bool *input); /* boolean CBOR simple value */ bool zcbor_float16_encode(zcbor_state_t *state, const float *input); /* IEEE754 float16 */ bool zcbor_float16_bytes_encode(zcbor_state_t *state, const uint16_t *input); /* IEEE754 float16 raw bytes */ bool zcbor_float32_encode(zcbor_state_t *state, const float *input); /* IEEE754 float32 */ bool zcbor_float64_encode(zcbor_state_t *state, const double *input); /* IEEE754 float64 */ /** Encode a list/map header. * * The contents of the list/map can be encoded via subsequent function calls. * If ZCBOR_CANONICAL is defined, a state backup is created to keep track of the * element count. * When all members have been encoded, call @ref zcbor_list_end_encode / * @ref zcbor_map_end_encode to close the list/map. * * @param[inout] state The current state of the encoding. * @param[in] max_num The maximum number of members in the list/map. * This serves as a size hint for the header. Must be * equal to the max_num provided to the corresponding * @ref zcbor_list_end_encode / @ref zcbor_map_end_encode * call. * Only used when ZCBOR_CANONICAL is defined. */ bool zcbor_list_start_encode(zcbor_state_t *state, size_t max_num); bool zcbor_map_start_encode(zcbor_state_t *state, size_t max_num); /** Encode the end of a list/map. Do some checks and deallocate backup. * * - Default: Adds a list terminator (0xFF) to mark the * end of the list/map. * - If ZCBOR_CANONICAL is defined: Instead encodes the number of members in * the list/map header. If the header ends up a different size than expected, * the list/map contents are moved using memmove(). * * Use @ref zcbor_list_map_end_force_encode to forcibly consume the backup if * something has gone wrong. * * @param[inout] state The current state of the encoding. * @param[in] max_num The maximum number of members in the list/map. Must be * equal to the max_num provided to the corresponding * @ref zcbor_list_start_encode call. * Only used when ZCBOR_CANONICAL is defined. */ bool zcbor_list_end_encode(zcbor_state_t *state, size_t max_num); bool zcbor_map_end_encode(zcbor_state_t *state, size_t max_num); bool zcbor_list_map_end_force_encode(zcbor_state_t *state); /** Encode 0 or more elements with the same type and constraints. * * The encoded values are taken from the @p input array. * * The following is an example of encoding a list containing 3 INTS followed by * 0 to 2 bstrs: * * @code{c} * uint32_t ints[3] = ; * struct zcbor_string bstrs[2] = ; * bool res; * * res = zcbor_list_start_encode(state, 5); * res = res && zcbor_multi_encode(3, zcbor_uint32_encode, state, * ints, sizeof(uint32_t)); * res = res && zcbor_multi_encode(2, zcbor_bstr_encode, state, * bstrs, sizeof(struct zcbor_string)); * res = res && zcbor_list_end_encode(state, 5); * // check res * @endcode * * The @ref zcbor_encoder_t type is designed to be compatible with all single- * value encoder functions in this library, e.g. @ref zcbor_uint32_encode, * @ref zcbor_tstr_put, @ref zcbor_nil_put, etc. For _put() functions, * @p input will be used as a value instead of an array/pointer, so * @p input_len will determine how much the value changes for each call. * To encode the same value multiple times, use a @p input_len of 0. * This function can also be used with custom decoder functions, such as those * generated by the zcbor.py script, which for example encodes larger chunks of * the data at once. * * @param[in] num_encode The actual number of elements. * @param[in] encoder The encoder function to call under the hood. This * function will be called with the provided arguments * repeatedly until the function fails (returns false) * or until it has been called @p max_encode times. * The input pointer is moved @p input_len bytes for * each call to @p encoder, i.e. @p input refers to an * array of input variables. * @param[in] input Source of the encoded values. Must be an array of * at least @p max_encode elements. * @param[in] input_len The length of the input variables. Must be the * length of the individual elements in input. * * @retval true If at least @p min_encode variables were correctly encoded. * @retval false If @p encoder failed before having encoded @p min_encode * values. */ bool zcbor_multi_encode(size_t num_encode, zcbor_encoder_t encoder, zcbor_state_t *state, const void *input, size_t result_len); /** Works like @ref zcbor_multi_encode * * But first checks that @p num_encode is between @p min_encode and @p max_encode. */ bool zcbor_multi_encode_minmax(size_t min_encode, size_t max_encode, const size_t *num_encode, zcbor_encoder_t encoder, zcbor_state_t *state, const void *input, size_t input_len); /* Supplementary string (bstr/tstr) encoding functions: */ /** Encode a char/uint8_t pointer as a bstr/tstr. * * @param[inout] state The current state of the encoding. * @param[in] str The value to encode. A pointer to the string/array. * _term() uses strnlen(), so @p str must be null-terminated. * _lit() uses sizeof()-1, so @p str must be a (null-terminated) string literal. * _arr() uses sizeof(), so @p str must be a uint8_t array (not null-terminated). * @param[in] len (if present) The length of the string pointed to by @p str * @param[in] maxlen (if present) The maximum length of the string pointed to by @p str. * This value is passed to strnlen. */ bool zcbor_bstr_encode_ptr(zcbor_state_t *state, const char *str, size_t len); bool zcbor_tstr_encode_ptr(zcbor_state_t *state, const char *str, size_t len); bool zcbor_bstr_put_term(zcbor_state_t *state, char const *str, size_t maxlen); bool zcbor_tstr_put_term(zcbor_state_t *state, char const *str, size_t maxlen); #define zcbor_bstr_put_lit(state, str) zcbor_bstr_encode_ptr(state, str, sizeof(str) - 1) #define zcbor_tstr_put_lit(state, str) zcbor_tstr_encode_ptr(state, str, sizeof(str) - 1) #define zcbor_bstr_put_arr(state, str) zcbor_bstr_encode_ptr(state, str, sizeof(str)) #define zcbor_tstr_put_arr(state, str) zcbor_tstr_encode_ptr(state, str, sizeof(str)) /** Encode a bstr header. * * The rest of the string can be encoded as CBOR. * A state backup is created to keep track of the element count. * Call @ref zcbor_bstr_end_encode when done encoding the contents of the bstr. * * @param[inout] state The current state of the encoding. * * @retval true Header encoded correctly * @retval false Header encoded incorrectly, or backup failed. */ bool zcbor_bstr_start_encode(zcbor_state_t *state); /** Finalize encoding a CBOR-encoded bstr. * * This writes the final size of the bstr to the header. * Restore element count from backup. */ bool zcbor_bstr_end_encode(zcbor_state_t *state, struct zcbor_string *result); #ifdef __cplusplus } #endif #endif /* ZCBOR_ENCODE_H__ */