1 /* 2 * Copyright (c) 2020 Nordic Semiconductor ASA 3 * 4 * SPDX-License-Identifier: Apache-2.0 5 */ 6 7 #ifndef ZCBOR_ENCODE_H__ 8 #define ZCBOR_ENCODE_H__ 9 10 #include <stdint.h> 11 #include <stdbool.h> 12 #include <stddef.h> 13 #include "zcbor_common.h" 14 15 #ifdef __cplusplus 16 extern "C" { 17 #endif 18 19 20 /** The zcbor_encode library provides functions for encoding CBOR data elements. 21 * 22 * See The README for an introduction to CBOR, including the meaning of pint, 23 * nint, bstr etc. 24 */ 25 26 27 /** See @ref zcbor_new_state() */ 28 void zcbor_new_encode_state(zcbor_state_t *state_array, size_t n_states, 29 uint8_t *payload, size_t payload_len, size_t elem_count); 30 31 /** Convenience macro for declaring and initializing an encoding state with backups. 32 * 33 * This gives you a state variable named @p name. The variable functions like 34 * a pointer. 35 * 36 * @param[in] name The name of the new state variable. 37 * @param[in] num_backups The number of backup slots to keep in the state. 38 * @param[in] payload The payload to work on. 39 * @param[in] payload_size The size (in bytes) of @p payload. 40 * @param[in] elem_count The starting elem_count (typically 1). 41 */ 42 #define ZCBOR_STATE_E(name, num_backups, payload, payload_size, elem_count) \ 43 zcbor_state_t name[((num_backups) + 2)]; \ 44 do { \ 45 zcbor_new_encode_state(name, ZCBOR_ARRAY_SIZE(name), payload, payload_size, elem_count); \ 46 } while(0) 47 48 49 /** The following applies to all _put and _encode functions listed directly below. 50 * 51 * The difference between _put and _encode is only in the argument type, 52 * but when a @ref zcbor_encoder_t is needed, such as for @ref zcbor_multi_encode, 53 * the _encode variant must be used. 54 * 55 * @param[inout] state The current state of the encoding. 56 * @param[in] input The value to encode. 57 * 58 * @retval true Everything is ok. 59 * @retval false If the payload is exhausted. Or an unexpected error happened. 60 * Use zcbor_peek_error() to see the error code. 61 */ 62 bool zcbor_int32_put(zcbor_state_t *state, int32_t input); /* pint/nint */ 63 bool zcbor_int64_put(zcbor_state_t *state, int64_t input); /* pint/nint */ 64 bool zcbor_uint32_put(zcbor_state_t *state, uint32_t input); /* pint */ 65 bool zcbor_uint64_put(zcbor_state_t *state, uint64_t input); /* pint */ 66 bool zcbor_size_put(zcbor_state_t *state, size_t input); /* pint */ 67 bool zcbor_tag_put(zcbor_state_t *state, uint32_t tag); /* CBOR tag */ 68 bool zcbor_simple_put(zcbor_state_t *state, uint8_t input); /* CBOR simple value */ 69 bool zcbor_bool_put(zcbor_state_t *state, bool input); /* boolean CBOR simple value */ 70 bool zcbor_nil_put(zcbor_state_t *state, const void *unused); /* 'nil' CBOR simple value */ 71 bool zcbor_undefined_put(zcbor_state_t *state, const void *unused); /* 'undefined' CBOR simple value */ 72 bool zcbor_float16_put(zcbor_state_t *state, float input); /* IEEE754 float16 */ 73 bool zcbor_float16_bytes_put(zcbor_state_t *state, uint16_t input); /* IEEE754 float16 raw bytes */ 74 bool zcbor_float32_put(zcbor_state_t *state, float input); /* IEEE754 float32 */ 75 bool zcbor_float64_put(zcbor_state_t *state, double input); /* IEEE754 float64 */ 76 77 bool zcbor_int32_encode(zcbor_state_t *state, const int32_t *input); /* pint/nint */ 78 bool zcbor_int64_encode(zcbor_state_t *state, const int64_t *input); /* pint/nint */ 79 bool zcbor_uint32_encode(zcbor_state_t *state, const uint32_t *input); /* pint */ 80 bool zcbor_uint64_encode(zcbor_state_t *state, const uint64_t *input); /* pint */ 81 bool zcbor_size_encode(zcbor_state_t *state, const size_t *input); /* pint */ 82 bool zcbor_int_encode(zcbor_state_t *state, const void *input_int, size_t int_size); 83 bool zcbor_uint_encode(zcbor_state_t *state, const void *input_uint, size_t uint_size); 84 bool zcbor_bstr_encode(zcbor_state_t *state, const struct zcbor_string *input); /* bstr */ 85 bool zcbor_tstr_encode(zcbor_state_t *state, const struct zcbor_string *input); /* tstr */ 86 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(). */ 87 bool zcbor_simple_encode(zcbor_state_t *state, uint8_t *input); /* CBOR simple value */ 88 bool zcbor_bool_encode(zcbor_state_t *state, const bool *input); /* boolean CBOR simple value */ 89 bool zcbor_float16_encode(zcbor_state_t *state, const float *input); /* IEEE754 float16 */ 90 bool zcbor_float16_bytes_encode(zcbor_state_t *state, const uint16_t *input); /* IEEE754 float16 raw bytes */ 91 bool zcbor_float32_encode(zcbor_state_t *state, const float *input); /* IEEE754 float32 */ 92 bool zcbor_float64_encode(zcbor_state_t *state, const double *input); /* IEEE754 float64 */ 93 94 /** Encode a list/map header. 95 * 96 * The contents of the list/map can be encoded via subsequent function calls. 97 * If ZCBOR_CANONICAL is defined, a state backup is created to keep track of the 98 * element count. 99 * When all members have been encoded, call @ref zcbor_list_end_encode / 100 * @ref zcbor_map_end_encode to close the list/map. 101 * 102 * @param[inout] state The current state of the encoding. 103 * @param[in] max_num The maximum number of members in the list/map. 104 * This serves as a size hint for the header. Must be 105 * equal to the max_num provided to the corresponding 106 * @ref zcbor_list_end_encode / @ref zcbor_map_end_encode 107 * call. 108 * Only used when ZCBOR_CANONICAL is defined. 109 */ 110 bool zcbor_list_start_encode(zcbor_state_t *state, size_t max_num); 111 bool zcbor_map_start_encode(zcbor_state_t *state, size_t max_num); 112 113 /** Encode the end of a list/map. Do some checks and deallocate backup. 114 * 115 * - Default: Adds a list terminator (0xFF) to mark the 116 * end of the list/map. 117 * - If ZCBOR_CANONICAL is defined: Instead encodes the number of members in 118 * the list/map header. If the header ends up a different size than expected, 119 * the list/map contents are moved using memmove(). 120 * 121 * Use @ref zcbor_list_map_end_force_encode to forcibly consume the backup if 122 * something has gone wrong. 123 * 124 * @param[inout] state The current state of the encoding. 125 * @param[in] max_num The maximum number of members in the list/map. Must be 126 * equal to the max_num provided to the corresponding 127 * @ref zcbor_list_start_encode call. 128 * Only used when ZCBOR_CANONICAL is defined. 129 */ 130 bool zcbor_list_end_encode(zcbor_state_t *state, size_t max_num); 131 bool zcbor_map_end_encode(zcbor_state_t *state, size_t max_num); 132 bool zcbor_list_map_end_force_encode(zcbor_state_t *state); 133 134 /** Encode 0 or more elements with the same type and constraints. 135 * 136 * The encoded values are taken from the @p input array. 137 * 138 * The following is an example of encoding a list containing 3 INTS followed by 139 * 0 to 2 bstrs: 140 * 141 * @code{c} 142 * uint32_t ints[3] = <initialize>; 143 * struct zcbor_string bstrs[2] = <initialize>; 144 * bool res; 145 * 146 * res = zcbor_list_start_encode(state, 5); 147 * res = res && zcbor_multi_encode(3, zcbor_uint32_encode, state, 148 * ints, sizeof(uint32_t)); 149 * res = res && zcbor_multi_encode(2, zcbor_bstr_encode, state, 150 * bstrs, sizeof(struct zcbor_string)); 151 * res = res && zcbor_list_end_encode(state, 5); 152 * // check res 153 * @endcode 154 * 155 * The @ref zcbor_encoder_t type is designed to be compatible with all single- 156 * value encoder functions in this library, e.g. @ref zcbor_uint32_encode, 157 * @ref zcbor_tstr_put, @ref zcbor_nil_put, etc. For _put() functions, 158 * @p input will be used as a value instead of an array/pointer, so 159 * @p input_len will determine how much the value changes for each call. 160 * To encode the same value multiple times, use a @p input_len of 0. 161 * This function can also be used with custom decoder functions, such as those 162 * generated by the zcbor.py script, which for example encodes larger chunks of 163 * the data at once. 164 * 165 * @param[in] num_encode The actual number of elements. 166 * @param[in] encoder The encoder function to call under the hood. This 167 * function will be called with the provided arguments 168 * repeatedly until the function fails (returns false) 169 * or until it has been called @p max_encode times. 170 * The input pointer is moved @p input_len bytes for 171 * each call to @p encoder, i.e. @p input refers to an 172 * array of input variables. 173 * @param[in] input Source of the encoded values. Must be an array of 174 * at least @p max_encode elements. 175 * @param[in] input_len The length of the input variables. Must be the 176 * length of the individual elements in input. 177 * 178 * @retval true If at least @p min_encode variables were correctly encoded. 179 * @retval false If @p encoder failed before having encoded @p min_encode 180 * values. 181 */ 182 bool zcbor_multi_encode(size_t num_encode, zcbor_encoder_t encoder, 183 zcbor_state_t *state, const void *input, size_t result_len); 184 185 /** Works like @ref zcbor_multi_encode 186 * 187 * But first checks that @p num_encode is between @p min_encode and @p max_encode. 188 */ 189 bool zcbor_multi_encode_minmax(size_t min_encode, size_t max_encode, 190 const size_t *num_encode, zcbor_encoder_t encoder, 191 zcbor_state_t *state, const void *input, size_t input_len); 192 193 194 /* Supplementary string (bstr/tstr) encoding functions: */ 195 196 /** Encode a char/uint8_t pointer as a bstr/tstr. 197 * 198 * @param[inout] state The current state of the encoding. 199 * @param[in] str The value to encode. A pointer to the string/array. 200 * _term() uses strnlen(), so @p str must be null-terminated. 201 * _lit() uses sizeof()-1, so @p str must be a (null-terminated) string literal. 202 * _arr() uses sizeof(), so @p str must be a uint8_t array (not null-terminated). 203 * @param[in] len (if present) The length of the string pointed to by @p str 204 * @param[in] maxlen (if present) The maximum length of the string pointed to by @p str. 205 * This value is passed to strnlen. 206 */ 207 bool zcbor_bstr_encode_ptr(zcbor_state_t *state, const char *str, size_t len); 208 bool zcbor_tstr_encode_ptr(zcbor_state_t *state, const char *str, size_t len); 209 bool zcbor_bstr_put_term(zcbor_state_t *state, char const *str, size_t maxlen); 210 bool zcbor_tstr_put_term(zcbor_state_t *state, char const *str, size_t maxlen); 211 #define zcbor_bstr_put_lit(state, str) zcbor_bstr_encode_ptr(state, str, sizeof(str) - 1) 212 #define zcbor_tstr_put_lit(state, str) zcbor_tstr_encode_ptr(state, str, sizeof(str) - 1) 213 #define zcbor_bstr_put_arr(state, str) zcbor_bstr_encode_ptr(state, str, sizeof(str)) 214 #define zcbor_tstr_put_arr(state, str) zcbor_tstr_encode_ptr(state, str, sizeof(str)) 215 216 /** Encode a bstr header. 217 * 218 * The rest of the string can be encoded as CBOR. 219 * A state backup is created to keep track of the element count. 220 * Call @ref zcbor_bstr_end_encode when done encoding the contents of the bstr. 221 * 222 * @param[inout] state The current state of the encoding. 223 * 224 * @retval true Header encoded correctly 225 * @retval false Header encoded incorrectly, or backup failed. 226 */ 227 bool zcbor_bstr_start_encode(zcbor_state_t *state); 228 229 /** Finalize encoding a CBOR-encoded bstr. 230 * 231 * This writes the final size of the bstr to the header. 232 * Restore element count from backup. 233 */ 234 bool zcbor_bstr_end_encode(zcbor_state_t *state, struct zcbor_string *result); 235 236 #ifdef __cplusplus 237 } 238 #endif 239 240 #endif /* ZCBOR_ENCODE_H__ */ 241
