Prompt file imported from PinkySan/ServerMock (.github/prompts/tcpmessage.prompt.md). Copyright stays with the author.

TCP messages

• All messages will be specified in a c compatible format
• The C-compatible format contains of
  • A fixed-size header
  • A variable-size payload
• The header contains the following fields
  • u32 - A Startbit, which is always 0xABCD
  • u32 - The message id
  • u32 - The length of the payload
  • u32 - The checksum of the header
• The payload contains the actual message
• The checksum is the sum of all bytes in the header, modulo 256
• Every message is defined by a message id
• The server should be able to handle multiple message ids
• The c-style messages must always be packed struct with no padding

Example message

#include <stdint.h>

enum message_id {
    MSG_ID_HELLO = 1,
    MSG_ID_GOODBYE = 2,
    MSG_ID_MEASUREMENT = 3,
    // Add more message IDs as needed
};
struct __attribute__((packed)) hello {
    uint32_t value;
};

struct __attribute__((packed)) goodbye {
    char message[256];
};

struct __attribute__((packed)) measurement {
    float temperature;
    float humidity;
};

Example tcp message

#include <stdint.h>

struct __attribute__((packed)) Message {
    uint32_t startbit;
    uint32_t message_id;
    uint32_t payload_length;
    uint32_t header_checksum;
    char payload[256];
};