mdtp.c

Purpose

MDTP (Modern Data Transmit Protocol) packet framing and parsing.

API Reference

Enum/string helpers

xpacket_type_t XPacket_GetType(const char *pType)

const char *XPacket_GetTypeStr(xpacket_type_t eType)

const char *XPacket_GetStatusStr(xpacket_status_t eStatus)

• Convert between enum and static text.

Lifecycle

xpacket_status_t XPacket_Init(xpacket_t *pPacket, uint8_t *pData, uint32_t nSize)

• Initializes packet state and optionally parses raw data.
• Returns packet status.

xpacket_t *XPacket_New(uint8_t *pData, uint32_t nSize)

• Allocates packet and initializes it.
• Returns packet or NULL.

void XPacket_Clear(xpacket_t *pPacket)

• Runs optional callback with XPACKET_CB_CLEAR, frees header object and clears raw storage.

void XPacket_Free(xpacket_t **pPacket)

• Clears and frees packet, then nulls caller pointer.

Parse / assemble

xpacket_status_t XPacket_Parse(xpacket_t *pPacket, const uint8_t *pData, size_t nSize)

• Parses 4-byte header length + JSON header + payload.
• Returns:
  • XPACKET_INCOMPLETE when even header is incomplete.
  • XPACKET_PARSED when header is complete but payload is incomplete.
  • XPACKET_COMPLETE when full packet is available.
  • error status otherwise.

xpacket_status_t XPacket_UpdateHeader(xpacket_t *pPacket)

• Rebuilds JSON header from pPacket->header.
• Returns packet status.

void XPacket_ParseHeader(xpacket_header_t *pHeader, xjson_obj_t *pHeaderObj)

• Extracts known fields from parsed header JSON.

xpacket_status_t XPacket_Create(xbyte_buffer_t *pBuffer, const char *pHeader, size_t nHdrLen, uint8_t *pData, size_t nSize)

• Appends one serialized packet into caller byte buffer.
• Returns packet status.

xbyte_buffer_t *XPacket_Assemble(xpacket_t *pPacket)

• Serializes packet header object plus payload into rawData.
• Returns pointer to rawData or NULL.

Access helpers

const uint8_t *XPacket_GetHeader(xpacket_t *pPacket)

const uint8_t *XPacket_GetPayload(xpacket_t *pPacket)

size_t XPacket_GetSize(xpacket_t *pPacket)

• Return header bytes, payload pointer or full packet size.
• Return NULL/0 when missing.