Files
ota-chunk-transfer/protocol/protocol.h
T
km b1c3ec3af4 Initial commit: OTA chunk transfer protocol implementation
- Protocol definition with 6-byte header (chunk_idx: 2B, payload: N B, crc32: 4B)
- Node.js server with chunk-based HTTP delivery
- C client library with resumable download support
- CRC32 implementation (IEEE 802.3)
- Test suites for both server and CRC32
- 1024B default chunk size (0.59% overhead)
2026-03-30 06:35:25 +09:00

302 lines
8.0 KiB
C

/**
* @file protocol.h
* @brief OTA Chunk Transfer Protocol Definitions
*/
#ifndef OTA_CHUNK_PROTOCOL_H
#define OTA_CHUNK_PROTOCOL_H
#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
#ifdef __cplusplus
extern "C" {
#endif
/* =========================================================================
* Protocol Constants
* ========================================================================= */
#define CHUNK_PROTOCOL_VERSION 1
#define CHUNK_DEFAULT_SIZE 1024
#define CHUNK_MIN_SIZE 256
#define CHUNK_MAX_SIZE 65535
#define CHUNK_INDEX_MAX 65535 /* 2-byte unsigned */
/* Maximum file size: CHUNK_INDEX_MAX * CHUNK_MAX_SIZE ≈ 4.29 GB */
#define CHUNK_MAX_FILE_SIZE ((uint32_t)CHUNK_INDEX_MAX * CHUNK_MAX_SIZE)
/* =========================================================================
* Protocol Structures
* ========================================================================= */
/**
* Chunk packet structure (network format)
*
* Layout:
* +------------+----------------+----------+
* | chunk_idx | payload (N B) | crc32 |
* | 2 B | N B | 4 B |
* +------------+----------------+----------+
*
* Note: This structure includes padding. Use packing for network transmission.
*/
#pragma pack(push, 1)
typedef struct {
uint16_t chunk_idx; /* Chunk index (little-endian) */
/* payload follows immediately */
/* crc32 follows payload */
} chunk_header_t;
#pragma pack(pop)
/**
* Chunk data descriptor (in-memory representation)
*/
typedef struct {
uint16_t chunk_idx; /* Chunk index */
uint16_t payload_len; /* Payload length */
uint8_t *payload; /* Payload pointer */
uint32_t crc32; /* CRC32 of payload */
} chunk_data_t;
/**
* Transfer state
*/
typedef enum {
CHUNK_STATE_IDLE,
CHUNK_STATE_FETCHING_SIZE,
CHUNK_STATE_TRANSFERRING,
CHUNK_STATE_RESUMING,
CHUNK_STATE_COMPLETE,
CHUNK_STATE_ERROR
} chunk_state_t;
/**
* Error codes
*/
typedef enum {
CHUNK_ERR_OK = 0,
CHUNK_ERR_INVALID_PARAM = -1,
CHUNK_ERR_MEMORY = -2,
CHUNK_ERR_NETWORK = -3,
CHUNK_ERR_CRC = -4,
CHUNK_ERR_FILE_NOT_FOUND = -5,
CHUNK_ERR_RANGE_INVALID = -6,
CHUNK_ERR_TIMEOUT = -7,
CHUNK_ERR_SERVER_ERROR = -8,
} chunk_err_t;
/* =========================================================================
* Callback Types
* ========================================================================= */
/**
* Chunk received callback
*
* @param chunk_idx Chunk index
* @param data Payload data
* @param len Payload length
* @param user_ctx User context
*/
typedef void (*chunk_received_cb)(uint16_t chunk_idx, const uint8_t *data,
uint16_t len, void *user_ctx);
/**
* Transfer complete callback
*
* @param total_bytes Total bytes transferred
* @param user_ctx User context
*/
typedef void (*transfer_complete_cb)(uint32_t total_bytes, void *user_ctx);
/**
* Transfer error callback
*
* @param err_code Error code
* @param user_ctx User context
*/
typedef void (*transfer_error_cb)(chunk_err_t err_code, void *user_ctx);
/**
* Progress update callback
*
* @param current_chunk Current chunk index
* @param total_chunks Total chunks
* @param user_ctx User context
*/
typedef void (*progress_cb)(uint16_t current_chunk, uint16_t total_chunks,
void *user_ctx);
/* =========================================================================
* Configuration Structures
* ========================================================================= */
/**
* Chunk client configuration
*/
typedef struct {
const char *server_url; /* Server base URL */
uint16_t chunk_size; /* Chunk size in bytes */
uint32_t timeout_ms; /* Timeout in milliseconds */
/* Callbacks */
chunk_received_cb on_chunk_received;
transfer_complete_cb on_complete;
transfer_error_cb on_error;
progress_cb on_progress;
void *user_ctx; /* User context passed to callbacks */
} chunk_client_config_t;
/**
* Chunk server configuration
*/
typedef struct {
uint16_t port; /* Server port */
const char *root_path; /* Root directory for files */
uint16_t chunk_size; /* Chunk size in bytes */
} chunk_server_config_t;
/* =========================================================================
* CRC32 Functions
* ========================================================================= */
/**
* Calculate CRC32 (IEEE 802.3 polynomial)
*
* @param data Input data
* @param len Input length
* @return CRC32 value
*/
uint32_t chunk_crc32(const uint8_t *data, size_t len);
/**
* Update CRC32 with additional data
*
* @param crc Previous CRC value
* @param data New data
* @param len Data length
* @return Updated CRC value
*/
uint32_t chunk_crc32_update(uint32_t crc, const uint8_t *data, size_t len);
/* =========================================================================
* Client Functions
* ========================================================================= */
/**
* Initialize chunk client
*
* @param config Configuration structure
* @return CHUNK_ERR_OK on success, error code otherwise
*/
chunk_err_t chunk_client_init(const chunk_client_config_t *config);
/**
* Start file download
*
* @param filename Filename to download
* @return CHUNK_ERR_OK on success, error code otherwise
*/
chunk_err_t chunk_client_download(const char *filename);
/**
* Resume download from specific chunk
*
* @param filename Filename to download
* @param start_chunk Chunk index to resume from
* @return CHUNK_ERR_OK on success, error code otherwise
*/
chunk_err_t chunk_client_resume(const char *filename, uint16_t start_chunk);
/**
* Cancel current transfer
*/
void chunk_client_cancel(void);
/**
* Get current transfer state
*
* @return Current state
*/
chunk_state_t chunk_client_get_state(void);
/**
* Get current progress
*
* @param current_chunk Current chunk index (output)
* @param total_chunks Total chunks (output)
* @return CHUNK_ERR_OK on success
*/
chunk_err_t chunk_client_get_progress(uint16_t *current_chunk,
uint16_t *total_chunks);
/**
* Cleanup client resources
*/
void chunk_client_cleanup(void);
/* =========================================================================
* Server Functions (for reference / embedded use)
* ========================================================================= */
/**
* Initialize chunk server
*
* @param config Configuration structure
* @return CHUNK_ERR_OK on success, error code otherwise
*/
chunk_err_t chunk_server_init(const chunk_server_config_t *config);
/**
* Start server (blocking)
*
* @return CHUNK_ERR_OK on success, error code otherwise
*/
chunk_err_t chunk_server_start(void);
/**
* Stop server
*/
void chunk_server_stop(void);
/* =========================================================================
* Utility Functions
* ========================================================================= */
/**
* Calculate total chunks for a file
*
* @param file_size File size in bytes
* @param chunk_size Chunk size in bytes
* @return Total number of chunks
*/
static inline uint16_t chunk_calc_total_chunks(uint32_t file_size,
uint16_t chunk_size) {
return (uint16_t)((file_size + chunk_size - 1) / chunk_size);
}
/**
* Calculate payload size for a chunk
*
* @param file_size File size in bytes
* @param chunk_idx Chunk index
* @param chunk_size Chunk size in bytes
* @return Payload size for this chunk
*/
static inline uint16_t chunk_calc_payload_size(uint32_t file_size,
uint16_t chunk_idx,
uint16_t chunk_size) {
uint32_t remaining = file_size - (uint32_t)chunk_idx * chunk_size;
return (uint16_t)(remaining < chunk_size ? remaining : chunk_size);
}
#ifdef __cplusplus
}
#endif
#endif /* OTA_CHUNK_PROTOCOL_H */