File syn_lwm2m.h¶

FileList > proto > syn_lwm2m.h

Zero-Heap OMA Lightweight M2M (LwM2M v1.1/v1.2) Core Client Engine. More...

#include "syntropic/common/syn_defs.h"
#include "syntropic/net/syn_coap.h"

Classes¶

Type	Name
struct	SYN_LwM2M_Client LwM2M Client Context.
struct	SYN_LwM2M_DeviceContext Device Object (Object ID 3) state and context.
struct	SYN_LwM2M_FirmwareContext Firmware Update Object (Object ID 5) context.
struct	SYN_LwM2M_Object LwM2M Object Definition.
struct	SYN_LwM2M_Observation Active resource or instance observation (RFC 7641).
struct	SYN_LwM2M_ResourceDesc Resource descriptor defining ID, permissions, and type.
struct	SYN_LwM2M_SensorContext Generic Sensor / Temperature Object (Object ID 3303) context.
struct	SYN_LwM2M_TLV Decoded / to-be-encoded LwM2M TLV item.
struct	SYN_LwM2M_Value LwM2M Generic Value Container.

Public Types¶

Type	Name
enum	SYN_LwM2M_ClientState LwM2M client registration states.
typedef SYN_Status(*	SYN_LwM2M_ExecCb Execute callback: executes an executable resource with optional arguments.
enum	SYN_LwM2M_FirmwareResult Firmware Update Object (Object ID 5) update results.
enum	SYN_LwM2M_FirmwareState Firmware Update Object (Object ID 5) states per OMA LwM2M spec.
typedef SYN_Status(*	SYN_LwM2M_ReadCb Read callback: retrieves current resource value.
enum	SYN_LwM2M_TLV_Type LwM2M TLV Type identifier (Bits 7-6 of TLV header byte).
enum	SYN_LwM2M_ValType LwM2M primitive resource value types.
typedef SYN_Status(*	SYN_LwM2M_WriteCb Write callback: writes new resource value.

Public Functions¶

Type	Name
size_t	syn_lwm2m_build_deregister_request (const SYN_LwM2M_Client * client, uint16_t msg_id, const uint8_t * token, uint8_t token_len, SYN_CoapMsg * req, SYN_CoapOption * req_opts, size_t max_req_opts, size_t * req_opt_cnt) Build a CoAP Deregistration DELETE request ( `/rd/<location>` ).
size_t	syn_lwm2m_build_notify (SYN_LwM2M_Client * client, uint16_t obj_id, uint16_t inst_id, int32_t res_id, uint16_t msg_id, SYN_CoapMsg * resp, SYN_CoapOption * resp_opts, size_t max_resp_opts, size_t * resp_opt_cnt, uint8_t * resp_buf, size_t resp_buf_sz) Build a CoAP Notification response for an active observation.
size_t	syn_lwm2m_build_register_request (const SYN_LwM2M_Client * client, uint16_t msg_id, const uint8_t * token, uint8_t token_len, SYN_CoapMsg * req, SYN_CoapOption * req_opts, size_t max_req_opts, size_t * req_opt_cnt, uint8_t * payload_buf, size_t payload_buf_sz) Build a CoAP Registration POST request ( `/rd?ep=...&lt=...` ).
size_t	syn_lwm2m_build_update_request (const SYN_LwM2M_Client * client, uint16_t msg_id, const uint8_t * token, uint8_t token_len, uint32_t lifetime_s, SYN_CoapMsg * req, SYN_CoapOption * req_opts, size_t max_req_opts, size_t * req_opt_cnt, uint8_t * payload_buf, size_t payload_buf_sz) Build a CoAP Registration Update POST request ( `/rd/<location>` ).
bool	syn_lwm2m_client_init (SYN_LwM2M_Client * client, const char * endpoint_name, uint32_t lifetime_s, SYN_Transport * transport) Initialize a zero-heap LwM2M client context.
size_t	syn_lwm2m_generate_link_format (const SYN_LwM2M_Client * client, char * buf, size_t max_len) Generate CoRE Link Format string listing all registered object instances.
bool	syn_lwm2m_handle_register_response (SYN_LwM2M_Client * client, const SYN_CoapMsg * resp, const SYN_CoapOption * resp_opts, size_t resp_opt_cnt) Handle server response to Registration request (parses Location-Path).
SYN_LwM2M_Object	syn_lwm2m_make_device_object (SYN_LwM2M_DeviceContext * ctx) Create an Object 3 (Device) descriptor bound to `ctx` .
SYN_LwM2M_Object	syn_lwm2m_make_firmware_object (SYN_LwM2M_FirmwareContext * ctx) Create an Object 5 (Firmware Update) descriptor bound to `ctx` .
SYN_LwM2M_Object	syn_lwm2m_make_temperature_object (SYN_LwM2M_SensorContext * ctx) Create an Object 3303 (Temperature Sensor) descriptor bound to `ctx` .
bool	syn_lwm2m_observe_add (SYN_LwM2M_Client * client, uint16_t obj_id, uint16_t inst_id, int32_t res_id, const uint8_t * token, uint8_t token_len, uint32_t pmin, uint32_t pmax) Add or update an observation for an object instance or resource.
bool	syn_lwm2m_observe_remove (SYN_LwM2M_Client * client, const uint8_t * token, uint8_t token_len) Remove an active observation by matching token.
SYN_Status	syn_lwm2m_process_request (SYN_LwM2M_Client * client, const SYN_CoapMsg * req, const SYN_CoapOption * req_opts, size_t req_opt_cnt, SYN_CoapMsg * resp, SYN_CoapOption * resp_opts, size_t max_resp_opts, size_t * resp_opt_cnt, uint8_t * resp_buf, size_t resp_buf_sz) Dispatch and process an incoming CoAP request against registered LwM2M objects.
bool	syn_lwm2m_register_object (SYN_LwM2M_Client * client, const SYN_LwM2M_Object * obj) Register an object definition into the client object registry.
bool	syn_lwm2m_tlv_decode (const uint8_t * buf, size_t buf_len, SYN_LwM2M_TLV * tlv, size_t * consumed) Decode a single TLV item from a byte stream.
bool	syn_lwm2m_tlv_decode_bool (const SYN_LwM2M_TLV * tlv, bool * out_val) Decode a boolean from TLV value bytes.
bool	syn_lwm2m_tlv_decode_float (const SYN_LwM2M_TLV * tlv, double * out_val) Decode a float/double from TLV value bytes.
bool	syn_lwm2m_tlv_decode_int (const SYN_LwM2M_TLV * tlv, int64_t * out_val) Decode a signed integer from TLV value bytes.
bool	syn_lwm2m_tlv_decode_string (const SYN_LwM2M_TLV * tlv, char * out_str, size_t max_len) Decode a string from TLV value bytes into a null-terminated buffer.
bool	syn_lwm2m_tlv_decode_value (const SYN_LwM2M_TLV * tlv, SYN_LwM2M_ValType expected_type, SYN_LwM2M_Value * out_val) Decode a TLV into a typed SYN_LwM2M_Value container.
size_t	syn_lwm2m_tlv_encode (const SYN_LwM2M_TLV * tlv, uint8_t * buf, size_t max_len) Encode a raw TLV header and value into a buffer.
size_t	syn_lwm2m_tlv_encode_bool (uint16_t res_id, bool val, uint8_t * buf, size_t max_len) Encode a boolean resource as TLV (1-byte int 0 or 1).
size_t	syn_lwm2m_tlv_encode_float (uint16_t res_id, double val, uint8_t * buf, size_t max_len) Encode a float/double resource as TLV (Float32 or Float64).
size_t	syn_lwm2m_tlv_encode_instance (uint16_t inst_id, const uint8_t * tlv_payload, size_t payload_len, uint8_t * buf, size_t max_len) Wrap nested resource TLVs inside an Object Instance TLV header.
size_t	syn_lwm2m_tlv_encode_int (uint16_t res_id, int64_t val, uint8_t * buf, size_t max_len) Encode a 64-bit integer resource as TLV.
size_t	syn_lwm2m_tlv_encode_opaque (uint16_t res_id, const uint8_t * data, size_t len, uint8_t * buf, size_t max_len) Encode opaque binary data resource as TLV.
size_t	syn_lwm2m_tlv_encode_string (uint16_t res_id, const char * str, uint8_t * buf, size_t max_len) Encode a string resource as TLV.
size_t	syn_lwm2m_tlv_encode_value (uint16_t res_id, const SYN_LwM2M_Value * val, uint8_t * buf, size_t max_len) Encode a generic SYN_LwM2M_Value as TLV.

Macros¶

Type	Name
define	SYN_LWM2M_FORMAT_CBOR `11544U`
define	SYN_LWM2M_FORMAT_JSON `11543U`
define	SYN_LWM2M_FORMAT_LINK_FORMAT `40U`
define	SYN_LWM2M_FORMAT_OPAQUE `42U`
define	SYN_LWM2M_FORMAT_SENML_CBOR `112U`
define	SYN_LWM2M_FORMAT_TEXT `0U`
define	SYN_LWM2M_FORMAT_TLV `11542U`
define	SYN_LWM2M_MAX_OBJECTS `16U`
define	SYN_LWM2M_MAX_OBSERVERS `8U`
define	SYN_LWM2M_MAX_URI_PATH_LEN `64U`
define	SYN_LWM2M_OBJ_ACCESS_CONTROL `2U`
define	SYN_LWM2M_OBJ_ACTUATION `3306U`
define	SYN_LWM2M_OBJ_CONNECTIVITY_MONITORING `4U`
define	SYN_LWM2M_OBJ_CONNECTIVITY_STATS `7U`
define	SYN_LWM2M_OBJ_DEVICE `3U`
define	SYN_LWM2M_OBJ_FIRMWARE_UPDATE `5U`
define	SYN_LWM2M_OBJ_GENERIC_SENSOR `3300U`
define	SYN_LWM2M_OBJ_HUMIDITY `3304U`
define	SYN_LWM2M_OBJ_LOCATION `6U`
define	SYN_LWM2M_OBJ_SECURITY `0U`
define	SYN_LWM2M_OBJ_SERVER `1U`
define	SYN_LWM2M_OBJ_TEMPERATURE `3303U`
define	SYN_LWM2M_OP_E `0x04U`
define	SYN_LWM2M_OP_NONE `0x00U`
define	SYN_LWM2M_OP_R `0x01U`
define	SYN_LWM2M_OP_RW `([SYN\_LWM2M\_OP\_R](syn__lwm2m_8h.md#define-syn_lwm2m_op_r) \\| [SYN\_LWM2M\_OP\_W](syn__lwm2m_8h.md#define-syn_lwm2m_op_w))`
define	SYN_LWM2M_OP_W `0x02U`

Detailed Description¶

Implements the OMA LwM2M client specification over CoAP/CoAPS, supporting: * Data formats: Plain Text, Opaque, TLV (Type-Length-Value Content-Format 11542), SenML CBOR (Content-Format 112). * Standard Object & Resource tree routing (/object/instance/resource). * Registration, Registration Update, and Deregistration workflows. * Device Management: Read, Write, Execute, Discover, Observe & Notify (RFC 7641). * Standard Objects: Device (Obj 3), Firmware Update (Obj 5), IPSO Temperature (Obj 3303).

Public Types Documentation¶

enum SYN_LwM2M_ClientState¶

LwM2M client registration states.

enum SYN_LwM2M_ClientState {
    SYN_LWM2M_STATE_DEREGISTERED = 0,
    SYN_LWM2M_STATE_REGISTERING,
    SYN_LWM2M_STATE_REGISTERED,
    SYN_LWM2M_STATE_UPDATING
};

typedef SYN_LwM2M_ExecCb¶

Execute callback: executes an executable resource with optional arguments.

typedef SYN_Status(* SYN_LwM2M_ExecCb) (uint16_t instance_id, uint16_t resource_id, const uint8_t *args, size_t args_len, void *user_ctx);

enum SYN_LwM2M_FirmwareResult¶

Firmware Update Object (Object ID 5) update results.

enum SYN_LwM2M_FirmwareResult {
    SYN_LWM2M_FW_RESULT_DEFAULT = 0,
    SYN_LWM2M_FW_RESULT_SUCCESS,
    SYN_LWM2M_FW_RESULT_NO_FLASH,
    SYN_LWM2M_FW_RESULT_OUT_OF_RAM,
    SYN_LWM2M_FW_RESULT_CONN_LOST,
    SYN_LWM2M_FW_RESULT_INTEGRITY_FAIL,
    SYN_LWM2M_FW_RESULT_BAD_PKG_TYPE,
    SYN_LWM2M_FW_RESULT_INVALID_URI
};

enum SYN_LwM2M_FirmwareState¶

Firmware Update Object (Object ID 5) states per OMA LwM2M spec.

enum SYN_LwM2M_FirmwareState {
    SYN_LWM2M_FW_STATE_IDLE = 0,
    SYN_LWM2M_FW_STATE_DOWNLOADING,
    SYN_LWM2M_FW_STATE_DOWNLOADED,
    SYN_LWM2M_FW_STATE_UPDATING
};

typedef SYN_LwM2M_ReadCb¶

Read callback: retrieves current resource value.

typedef SYN_Status(* SYN_LwM2M_ReadCb) (uint16_t instance_id, uint16_t resource_id, SYN_LwM2M_Value *out_val, void *user_ctx);

enum SYN_LwM2M_TLV_Type¶

LwM2M TLV Type identifier (Bits 7-6 of TLV header byte).

enum SYN_LwM2M_TLV_Type {
    SYN_LWM2M_TLV_OBJECT_INSTANCE = 0x00U,
    SYN_LWM2M_TLV_RESOURCE_INSTANCE = 0x40U,
    SYN_LWM2M_TLV_MULTIPLE_RESOURCE = 0x80U,
    SYN_LWM2M_TLV_RESOURCE = 0xC0U
};

enum SYN_LwM2M_ValType¶

LwM2M primitive resource value types.

enum SYN_LwM2M_ValType {
    SYN_LWM2M_TYPE_NONE = 0,
    SYN_LWM2M_TYPE_STRING,
    SYN_LWM2M_TYPE_INT,
    SYN_LWM2M_TYPE_FLOAT,
    SYN_LWM2M_TYPE_BOOL,
    SYN_LWM2M_TYPE_OPAQUE,
    SYN_LWM2M_TYPE_TIME,
    SYN_LWM2M_TYPE_OBJLNK
};

typedef SYN_LwM2M_WriteCb¶

Write callback: writes new resource value.

typedef SYN_Status(* SYN_LwM2M_WriteCb) (uint16_t instance_id, uint16_t resource_id, const SYN_LwM2M_Value *in_val, void *user_ctx);

Public Functions Documentation¶

function syn_lwm2m_build_deregister_request¶

Build a CoAP Deregistration DELETE request ( /rd/<location> ).

size_t syn_lwm2m_build_deregister_request (
    const SYN_LwM2M_Client * client,
    uint16_t msg_id,
    const uint8_t * token,
    uint8_t token_len,
    SYN_CoapMsg * req,
    SYN_CoapOption * req_opts,
    size_t max_req_opts,
    size_t * req_opt_cnt
)

Parameters:

client LwM2M client context.
msg_id CoAP message ID.
token CoAP token bytes.
token_len Length of CoAP token.
req [out] Populated CoAP request header.
req_opts [out] Populated CoAP options array.
max_req_opts Capacity of options array.
req_opt_cnt [out] Number of populated options.

Returns:

0 on success.

function syn_lwm2m_build_notify¶

Build a CoAP Notification response for an active observation.

size_t syn_lwm2m_build_notify (
    SYN_LwM2M_Client * client,
    uint16_t obj_id,
    uint16_t inst_id,
    int32_t res_id,
    uint16_t msg_id,
    SYN_CoapMsg * resp,
    SYN_CoapOption * resp_opts,
    size_t max_resp_opts,
    size_t * resp_opt_cnt,
    uint8_t * resp_buf,
    size_t resp_buf_sz
)

Parameters:

client LwM2M client context.
obj_id Object ID.
inst_id Instance ID.
res_id Resource ID (-1 for entire instance).
msg_id CoAP message ID.
resp [out] Populated CoAP notification response header.
resp_opts [out] Output response options array.
max_resp_opts Capacity of response options array.
resp_opt_cnt [out] Number of populated response options.
resp_buf [out] Buffer for notification payload.
resp_buf_sz Capacity of notification buffer.

Returns:

Length of encoded payload in bytes, or 0 on error.

function syn_lwm2m_build_register_request¶

Build a CoAP Registration POST request ( /rd?ep=...&lt=... ).

size_t syn_lwm2m_build_register_request (
    const SYN_LwM2M_Client * client,
    uint16_t msg_id,
    const uint8_t * token,
    uint8_t token_len,
    SYN_CoapMsg * req,
    SYN_CoapOption * req_opts,
    size_t max_req_opts,
    size_t * req_opt_cnt,
    uint8_t * payload_buf,
    size_t payload_buf_sz
)

Parameters:

client LwM2M client context.
msg_id CoAP message ID.
token CoAP token bytes.
token_len Length of CoAP token.
req [out] Populated CoAP request header.
req_opts [out] Populated CoAP options array.
max_req_opts Capacity of options array.
req_opt_cnt [out] Number of populated options.
payload_buf [out] Buffer for link format payload.
payload_buf_sz Capacity of payload buffer.

Returns:

Length of serialized payload in bytes, or 0 on error.

function syn_lwm2m_build_update_request¶

Build a CoAP Registration Update POST request ( /rd/<location> ).

size_t syn_lwm2m_build_update_request (
    const SYN_LwM2M_Client * client,
    uint16_t msg_id,
    const uint8_t * token,
    uint8_t token_len,
    uint32_t lifetime_s,
    SYN_CoapMsg * req,
    SYN_CoapOption * req_opts,
    size_t max_req_opts,
    size_t * req_opt_cnt,
    uint8_t * payload_buf,
    size_t payload_buf_sz
)

Parameters:

client LwM2M client context.
msg_id CoAP message ID.
token CoAP token bytes.
token_len Length of CoAP token.
lifetime_s Updated registration lifetime in seconds (0 to keep current).
req [out] Populated CoAP request header.
req_opts [out] Populated CoAP options array.
max_req_opts Capacity of options array.
req_opt_cnt [out] Number of populated options.
payload_buf [out] Optional buffer for updated link format.
payload_buf_sz Capacity of payload buffer.

Returns:

Length of payload in bytes (0 if lifetime update only).

function syn_lwm2m_client_init¶

Initialize a zero-heap LwM2M client context.

bool syn_lwm2m_client_init (
    SYN_LwM2M_Client * client,
    const char * endpoint_name,
    uint32_t lifetime_s,
    SYN_Transport * transport
)

Parameters:

client Client context to initialize.
endpoint_name Client endpoint name (e.g. "urn:imei:862415039201923").
lifetime_s Registration lifetime in seconds (e.g. 300).
transport Underlying datagram transport.

Returns:

true on success, false on invalid parameters.

function syn_lwm2m_generate_link_format¶

Generate CoRE Link Format string listing all registered object instances.

size_t syn_lwm2m_generate_link_format (
    const SYN_LwM2M_Client * client,
    char * buf,
    size_t max_len
)

Example output: </1/0>, </3/0>, </5/0>, </3303/0>

Parameters:

client LwM2M client context.
buf [out] Buffer to receive link format string.
max_len Capacity of link format buffer.

Returns:

Number of characters written (excluding null terminator), or 0 on overflow.

function syn_lwm2m_handle_register_response¶

Handle server response to Registration request (parses Location-Path).

bool syn_lwm2m_handle_register_response (
    SYN_LwM2M_Client * client,
    const SYN_CoapMsg * resp,
    const SYN_CoapOption * resp_opts,
    size_t resp_opt_cnt
)

Parameters:

client LwM2M client context.
resp Received CoAP response.
resp_opts Received response options.
resp_opt_cnt Number of response options.

Returns:

true if registration succeeded (2.01 Created), false otherwise.

function syn_lwm2m_make_device_object¶

Create an Object 3 (Device) descriptor bound to ctx .

SYN_LwM2M_Object syn_lwm2m_make_device_object (
    SYN_LwM2M_DeviceContext * ctx
)

Parameters:

ctx Device object context state.

Returns:

Initialized LwM2M object descriptor.

function syn_lwm2m_make_firmware_object¶

Create an Object 5 (Firmware Update) descriptor bound to ctx .

SYN_LwM2M_Object syn_lwm2m_make_firmware_object (
    SYN_LwM2M_FirmwareContext * ctx
)

Parameters:

ctx Firmware update object context state.

Returns:

Initialized LwM2M object descriptor.

function syn_lwm2m_make_temperature_object¶

Create an Object 3303 (Temperature Sensor) descriptor bound to ctx .

SYN_LwM2M_Object syn_lwm2m_make_temperature_object (
    SYN_LwM2M_SensorContext * ctx
)

Parameters:

ctx Temperature sensor object context state.

Returns:

Initialized LwM2M object descriptor.

function syn_lwm2m_observe_add¶

Add or update an observation for an object instance or resource.

bool syn_lwm2m_observe_add (
    SYN_LwM2M_Client * client,
    uint16_t obj_id,
    uint16_t inst_id,
    int32_t res_id,
    const uint8_t * token,
    uint8_t token_len,
    uint32_t pmin,
    uint32_t pmax
)

Parameters:

client LwM2M client context.
obj_id Object ID.
inst_id Instance ID.
res_id Resource ID (-1 for entire instance).
token CoAP observation token.
token_len Length of token.
pmin Minimum period in seconds (0 = immediate).
pmax Maximum period in seconds (0 = none).

Returns:

true on success, false if table full.

function syn_lwm2m_observe_remove¶

Remove an active observation by matching token.

bool syn_lwm2m_observe_remove (
    SYN_LwM2M_Client * client,
    const uint8_t * token,
    uint8_t token_len
)

Parameters:

client LwM2M client context.
token CoAP token bytes.
token_len Length of token.

Returns:

true if an entry was found and removed, false otherwise.

function syn_lwm2m_process_request¶

Dispatch and process an incoming CoAP request against registered LwM2M objects.

SYN_Status syn_lwm2m_process_request (
    SYN_LwM2M_Client * client,
    const SYN_CoapMsg * req,
    const SYN_CoapOption * req_opts,
    size_t req_opt_cnt,
    SYN_CoapMsg * resp,
    SYN_CoapOption * resp_opts,
    size_t max_resp_opts,
    size_t * resp_opt_cnt,
    uint8_t * resp_buf,
    size_t resp_buf_sz
)

Handles GET (Read / Discover), PUT/POST (Write), POST (Execute), DELETE.

Parameters:

client LwM2M client context.
req Incoming CoAP request.
req_opts Request options (Uri-Path, Content-Format, Observe, etc.).
req_opt_cnt Number of request options.
resp [out] Prepared CoAP response.
resp_opts [out] Output response options array.
max_resp_opts Capacity of response options array.
resp_opt_cnt [out] Number of populated response options.
resp_buf [out] Buffer for response payload.
resp_buf_sz Capacity of response buffer.

Returns:

SYN_OK on successful request handling, error code otherwise.

function syn_lwm2m_register_object¶

Register an object definition into the client object registry.

bool syn_lwm2m_register_object (
    SYN_LwM2M_Client * client,
    const SYN_LwM2M_Object * obj
)

Parameters:

client LwM2M client context.
obj Object definition descriptor.

Returns:

true on success, false if registry is full or invalid parameters.

function syn_lwm2m_tlv_decode¶

Decode a single TLV item from a byte stream.

bool syn_lwm2m_tlv_decode (
    const uint8_t * buf,
    size_t buf_len,
    SYN_LwM2M_TLV * tlv,
    size_t * consumed
)

Parameters:

buf Input buffer.
buf_len Available bytes in buffer.
tlv [out] Decoded TLV header and value pointer.
consumed [out] Total bytes consumed for this TLV.

Returns:

true on success, false on format/length error.

function syn_lwm2m_tlv_decode_bool¶

Decode a boolean from TLV value bytes.

bool syn_lwm2m_tlv_decode_bool (
    const SYN_LwM2M_TLV * tlv,
    bool * out_val
)

Parameters:

tlv Decoded TLV descriptor.
out_val [out] Decoded boolean.

Returns:

true on success, false on length error or null parameters.

function syn_lwm2m_tlv_decode_float¶

Decode a float/double from TLV value bytes.

bool syn_lwm2m_tlv_decode_float (
    const SYN_LwM2M_TLV * tlv,
    double * out_val
)

Parameters:

tlv Decoded TLV descriptor.
out_val [out] Decoded double.

Returns:

true on success, false on length error or null parameters.

function syn_lwm2m_tlv_decode_int¶

Decode a signed integer from TLV value bytes.

bool syn_lwm2m_tlv_decode_int (
    const SYN_LwM2M_TLV * tlv,
    int64_t * out_val
)

Parameters:

tlv Decoded TLV descriptor.
out_val [out] Decoded 64-bit integer.

Returns:

true on success, false on length error or null parameters.

function syn_lwm2m_tlv_decode_string¶

Decode a string from TLV value bytes into a null-terminated buffer.

bool syn_lwm2m_tlv_decode_string (
    const SYN_LwM2M_TLV * tlv,
    char * out_str,
    size_t max_len
)

Parameters:

tlv Decoded TLV descriptor.
out_str [out] Target buffer for string.
max_len Capacity of target buffer.

Returns:

true on success, false on overflow or null parameters.

function syn_lwm2m_tlv_decode_value¶

Decode a TLV into a typed SYN_LwM2M_Value container.

bool syn_lwm2m_tlv_decode_value (
    const SYN_LwM2M_TLV * tlv,
    SYN_LwM2M_ValType expected_type,
    SYN_LwM2M_Value * out_val
)

Parameters:

tlv Decoded TLV descriptor.
expected_type Expected value type.
out_val [out] Decoded value container.

Returns:

true on success, false on decoding failure.

function syn_lwm2m_tlv_encode¶

Encode a raw TLV header and value into a buffer.

size_t syn_lwm2m_tlv_encode (
    const SYN_LwM2M_TLV * tlv,
    uint8_t * buf,
    size_t max_len
)

Parameters:

tlv TLV item to encode.
buf [out] Target buffer.
max_len Capacity of target buffer.

Returns:

Number of bytes written, or 0 on buffer overflow.

function syn_lwm2m_tlv_encode_bool¶

Encode a boolean resource as TLV (1-byte int 0 or 1).

size_t syn_lwm2m_tlv_encode_bool (
    uint16_t res_id,
    bool val,
    uint8_t * buf,
    size_t max_len
)

Parameters:

res_id Resource ID.
val Boolean value.
buf [out] Target buffer.
max_len Capacity of target buffer.

Returns:

Number of bytes written, or 0 on overflow.

function syn_lwm2m_tlv_encode_float¶

Encode a float/double resource as TLV (Float32 or Float64).

size_t syn_lwm2m_tlv_encode_float (
    uint16_t res_id,
    double val,
    uint8_t * buf,
    size_t max_len
)

Parameters:

res_id Resource ID.
val Floating-point value.
buf [out] Target buffer.
max_len Capacity of target buffer.

Returns:

Number of bytes written, or 0 on overflow.

function syn_lwm2m_tlv_encode_instance¶

Wrap nested resource TLVs inside an Object Instance TLV header.

size_t syn_lwm2m_tlv_encode_instance (
    uint16_t inst_id,
    const uint8_t * tlv_payload,
    size_t payload_len,
    uint8_t * buf,
    size_t max_len
)

Parameters:

inst_id Object instance ID.
tlv_payload Serialized resource TLVs buffer.
payload_len Length of resource TLVs.
buf [out] Target buffer.
max_len Capacity of target buffer.

Returns:

Number of bytes written, or 0 on overflow.

function syn_lwm2m_tlv_encode_int¶

Encode a 64-bit integer resource as TLV.

size_t syn_lwm2m_tlv_encode_int (
    uint16_t res_id,
    int64_t val,
    uint8_t * buf,
    size_t max_len
)

Parameters:

res_id Resource ID.
val Integer value to encode.
buf [out] Target buffer.
max_len Capacity of target buffer.

Returns:

Number of bytes written, or 0 on overflow.

function syn_lwm2m_tlv_encode_opaque¶

Encode opaque binary data resource as TLV.

size_t syn_lwm2m_tlv_encode_opaque (
    uint16_t res_id,
    const uint8_t * data,
    size_t len,
    uint8_t * buf,
    size_t max_len
)

Parameters:

res_id Resource ID.
data Binary buffer.
len Length of binary data.
buf [out] Target buffer.
max_len Capacity of target buffer.

Returns:

Number of bytes written, or 0 on overflow.

function syn_lwm2m_tlv_encode_string¶

Encode a string resource as TLV.

size_t syn_lwm2m_tlv_encode_string (
    uint16_t res_id,
    const char * str,
    uint8_t * buf,
    size_t max_len
)

Parameters:

res_id Resource ID.
str Null-terminated string.
buf [out] Target buffer.
max_len Capacity of target buffer.

Returns:

Number of bytes written, or 0 on overflow.

function syn_lwm2m_tlv_encode_value¶

Encode a generic SYN_LwM2M_Value as TLV.

size_t syn_lwm2m_tlv_encode_value (
    uint16_t res_id,
    const SYN_LwM2M_Value * val,
    uint8_t * buf,
    size_t max_len
)

Parameters:

res_id Resource ID.
val Typed resource value container.
buf [out] Target buffer.
max_len Capacity of target buffer.

Returns:

Number of bytes written, or 0 on overflow.

Macro Definition Documentation¶

define SYN_LWM2M_FORMAT_CBOR¶

#define SYN_LWM2M_FORMAT_CBOR `11544U`

application/vnd.oma.lwm2m+cbor

define SYN_LWM2M_FORMAT_JSON¶

#define SYN_LWM2M_FORMAT_JSON `11543U`

application/vnd.oma.lwm2m+json

define SYN_LWM2M_FORMAT_LINK_FORMAT¶

#define SYN_LWM2M_FORMAT_LINK_FORMAT `40U`

application/link-format

define SYN_LWM2M_FORMAT_OPAQUE¶

#define SYN_LWM2M_FORMAT_OPAQUE `42U`

application/octet-stream

define SYN_LWM2M_FORMAT_SENML_CBOR¶

#define SYN_LWM2M_FORMAT_SENML_CBOR `112U`

application/senml+cbor

define SYN_LWM2M_FORMAT_TEXT¶

#define SYN_LWM2M_FORMAT_TEXT `0U`

text/plain

define SYN_LWM2M_FORMAT_TLV¶

#define SYN_LWM2M_FORMAT_TLV `11542U`

application/vnd.oma.lwm2m+tlv

define SYN_LWM2M_MAX_OBJECTS¶

#define SYN_LWM2M_MAX_OBJECTS `16U`

Maximum registered objects per client

define SYN_LWM2M_MAX_OBSERVERS¶

#define SYN_LWM2M_MAX_OBSERVERS `8U`

Maximum active resource observations

define SYN_LWM2M_MAX_URI_PATH_LEN¶

#define SYN_LWM2M_MAX_URI_PATH_LEN `64U`

Max URI path buffer size

define SYN_LWM2M_OBJ_ACCESS_CONTROL¶

#define SYN_LWM2M_OBJ_ACCESS_CONTROL `2U`

Access Control Object

define SYN_LWM2M_OBJ_ACTUATION¶

#define SYN_LWM2M_OBJ_ACTUATION `3306U`

IPSO Actuation / Switch

define SYN_LWM2M_OBJ_CONNECTIVITY_MONITORING¶

#define SYN_LWM2M_OBJ_CONNECTIVITY_MONITORING `4U`

Connectivity Monitoring

define SYN_LWM2M_OBJ_CONNECTIVITY_STATS¶

#define SYN_LWM2M_OBJ_CONNECTIVITY_STATS `7U`

Connectivity Statistics

define SYN_LWM2M_OBJ_DEVICE¶

#define SYN_LWM2M_OBJ_DEVICE `3U`

Device Object

define SYN_LWM2M_OBJ_FIRMWARE_UPDATE¶

#define SYN_LWM2M_OBJ_FIRMWARE_UPDATE `5U`

Firmware Update Object

define SYN_LWM2M_OBJ_GENERIC_SENSOR¶

#define SYN_LWM2M_OBJ_GENERIC_SENSOR `3300U`

IPSO Generic Sensor

define SYN_LWM2M_OBJ_HUMIDITY¶

#define SYN_LWM2M_OBJ_HUMIDITY `3304U`

IPSO Humidity Sensor

define SYN_LWM2M_OBJ_LOCATION¶

#define SYN_LWM2M_OBJ_LOCATION `6U`

Location Object

define SYN_LWM2M_OBJ_SECURITY¶

#define SYN_LWM2M_OBJ_SECURITY `0U`

LwM2M Security Object

define SYN_LWM2M_OBJ_SERVER¶

#define SYN_LWM2M_OBJ_SERVER `1U`

LwM2M Server Object

define SYN_LWM2M_OBJ_TEMPERATURE¶

#define SYN_LWM2M_OBJ_TEMPERATURE `3303U`

IPSO Temperature Sensor

define SYN_LWM2M_OP_E¶

#define SYN_LWM2M_OP_E `0x04U`

Execute operation allowed

define SYN_LWM2M_OP_NONE¶

#define SYN_LWM2M_OP_NONE `0x00U`

No access permitted

define SYN_LWM2M_OP_R¶

#define SYN_LWM2M_OP_R `0x01U`

Read operation allowed

define SYN_LWM2M_OP_RW¶

#define SYN_LWM2M_OP_RW `( SYN_LWM2M_OP_R | SYN_LWM2M_OP_W )`

Read/Write allowed

define SYN_LWM2M_OP_W¶

#define SYN_LWM2M_OP_W `0x02U`

Write operation allowed

The documentation for this class was generated from the following file src/syntropic/proto/syn_lwm2m.h