toxcore/bin_unpack.h
Rama master · réplica de lectura del repositorio original.
/* SPDX-License-Identifier: GPL-3.0-or-later
* Copyright © 2022-2026 The TokTok team.
*/
#ifndef C_TOXCORE_TOXCORE_BIN_UNPACK_H
#define C_TOXCORE_TOXCORE_BIN_UNPACK_H
#include <stdbool.h>
#include <stdint.h>
#include "attributes.h"
#include "mem.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Binary deserialisation object.
*
* User code never creates this object. It is created and destroyed within the below functions,
* and passed to the callback. This enforces an alloc/dealloc bracket, so user code can never
* forget to clean up an unpacker.
*/
typedef struct Bin_Unpack Bin_Unpack;
/** @brief Function used to unpack an object.
*
* This function would typically cast the `void *` to the actual object pointer type and then call
* more appropriately typed unpacking functions.
*/
typedef bool bin_unpack_cb(void *_Nonnull obj, Bin_Unpack *_Nonnull bu);
/** @brief Unpack an object from a buffer of a given size.
*
* This function creates and initialises a `Bin_Unpack` object, calls the callback with the
* unpacker object and the to-be-unpacked object, and then cleans up the unpacker object.
*
* Unlike `bin_pack_obj`, this function does not support NULL anywhere. The input array
* must be non-null, even if it is zero-length.
*
* @param callback The function called on the created unpacker and unpacked object.
* @param obj The object to be packed, passed as `obj` to the callback.
* @param buf A byte array containing the serialised representation of `obj`.
* @param buf_size The size of the byte array.
*
* @retval false if an error occurred (e.g. buffer overrun).
*/
bool bin_unpack_obj(const Memory *_Nonnull mem, bin_unpack_cb *_Nonnull callback, void *_Nonnull obj, const uint8_t *_Nonnull buf, uint32_t buf_size);
/** @brief Start unpacking a MessagePack array.
*
* A call to this function must be followed by exactly `size` calls to other functions below.
*
* @param size Will contain the number of array elements following the array marker.
*/
bool bin_unpack_array(Bin_Unpack *_Nonnull bu, uint32_t *_Nonnull size);
/** @brief Start unpacking a fixed size MessagePack array.
*
* Fails if the array size is not the required size. If `actual_size` is passed a non-null
* pointer, the array size is written there.
*
* @retval false if the packed array size is not exactly the required size.
*/
bool bin_unpack_array_fixed(Bin_Unpack *_Nonnull bu, uint32_t required_size, uint32_t *_Nullable actual_size);
/** @brief Unpack a MessagePack bool. */
bool bin_unpack_bool(Bin_Unpack *_Nonnull bu, bool *_Nonnull val);
/** @brief Unpack a MessagePack positive int into a `uint8_t`. */
bool bin_unpack_u08(Bin_Unpack *_Nonnull bu, uint8_t *_Nonnull val);
/** @brief Unpack a MessagePack positive int into a `uint16_t`. */
bool bin_unpack_u16(Bin_Unpack *_Nonnull bu, uint16_t *_Nonnull val);
/** @brief Unpack a MessagePack positive int into a `uint32_t`. */
bool bin_unpack_u32(Bin_Unpack *_Nonnull bu, uint32_t *_Nonnull val);
/** @brief Unpack a MessagePack positive int into a `uint64_t`. */
bool bin_unpack_u64(Bin_Unpack *_Nonnull bu, uint64_t *_Nonnull val);
/** @brief Unpack a Messagepack nil value. */
bool bin_unpack_nil(Bin_Unpack *_Nonnull bu);
/** @brief Unpack a MessagePack bin into a newly allocated byte array.
*
* Allocates a new byte array and stores it into `data_ptr` with its length stored in
* `data_length_ptr`. This function requires that the unpacking buffer has at least as many bytes
* remaining to be unpacked as the bin claims to need, so it's not possible to cause an arbitrarily
* large allocation unless the input array was already that large.
*/
bool bin_unpack_bin(Bin_Unpack *_Nonnull bu, uint8_t *_Nullable *_Nonnull data_ptr, uint32_t *_Nonnull data_length_ptr);
/** @brief Unpack a MessagePack str into a newly allocated string. */
bool bin_unpack_str(Bin_Unpack *_Nonnull bu, char *_Nonnull *_Nonnull str_ptr, uint32_t *_Nonnull str_length_ptr);
/** @brief Unpack a variable size MessagePack bin into a fixed size byte array.
*
* Stores unpacked data into `data` with its length stored in `data_length_ptr`. This function does
* not allocate memory and requires that `max_data_length` is less than or equal to `sizeof(arr)`
* when `arr` is passed as `data` pointer.
*/
bool bin_unpack_bin_max(Bin_Unpack *_Nonnull bu, uint8_t *_Nonnull data, uint16_t *_Nonnull data_length_ptr, uint16_t max_data_length);
/** @brief Unpack a MessagePack bin of a fixed length into a pre-allocated byte array.
*
* Similar to the function above, but doesn't output the data length.
*/
bool bin_unpack_bin_fixed(Bin_Unpack *_Nonnull bu, uint8_t *_Nonnull data, uint32_t data_length);
/** @brief Start unpacking a custom binary representation.
*
* A call to this function must be followed by exactly `size` bytes packed by functions below.
*/
bool bin_unpack_bin_size(Bin_Unpack *_Nonnull bu, uint32_t *_Nonnull size);
/** @brief Read a `uint8_t` directly from the unpacker, consuming 1 byte. */
bool bin_unpack_u08_b(Bin_Unpack *_Nonnull bu, uint8_t *_Nonnull val);
/** @brief Read a `uint16_t` as big endian 16 bit int, consuming 2 bytes. */
bool bin_unpack_u16_b(Bin_Unpack *_Nonnull bu, uint16_t *_Nonnull val);
/** @brief Read a `uint32_t` as big endian 32 bit int, consuming 4 bytes. */
bool bin_unpack_u32_b(Bin_Unpack *_Nonnull bu, uint32_t *_Nonnull val);
/** @brief Read a `uint64_t` as big endian 64 bit int, consuming 8 bytes. */
bool bin_unpack_u64_b(Bin_Unpack *_Nonnull bu, uint64_t *_Nonnull val);
/** @brief Read a byte array directly from the packer, consuming `length` bytes. */
bool bin_unpack_bin_b(Bin_Unpack *_Nonnull bu, uint8_t *_Nullable data, uint32_t length);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* C_TOXCORE_TOXCORE_BIN_UNPACK_H */