nanoCoAP small CoAP library

CoAP library optimized for minimal resource usage. More...

Detailed Description

CoAP library optimized for minimal resource usage.

nanocoap is a toolbox for reading and writing CoAP messages. It provides functions for core header attributes like message type and code. It also provides high and low level interfaces to CoAP options, including Block.

nanocoap includes the core structs to store message information. It also provides helper functions for use before sending and after receiving a message, such as coap_parse() to read an incoming message.

Application APIs

This page provides reference documentation for the contents of nanocoap. To use nanocoap in an application, see the functional APIs that are built with it. nanocoap sock is for a targeted client or server with lesser resource requirements, and gcoap provides a more featureful messaging hub.

Option APIs

For both server responses and client requests, CoAP uses an Option mechanism to encode message metadata that is not required for each message. For example, the resource URI path is required only for a request, and is encoded as the Uri-Path option.

nanocoap sock uses the simpler Buffer API, described in the section Options Write Buffer API. gcoap uses the more convenient Packet API, described in the section Options Write Packet API.

For either API, the caller must write options in order by option number (see "CoAP option numbers" in CoAP defines).

Server path matching

By default the URI-path of an incoming request should match exactly one of the registered resources. But also, a resource can be configured to match just a prefix of the URI-path of the request by adding the COAP_MATCH_SUBTREE option to coap_resource_t::methods.

For example, if a resource is configured with a path /resource01 and the COAP_MATCH_SUBTREE option is used it would match any of /resource01/, /resource01/sub/path, /resource01alt.

If the behavior of matching /resource01alt is not wanted and only subtrees are wanted to match, the path should be /resource01/.

If in addition just /resource01 is wanted to match, together with any subtrees of /resource01/, then a first resource with the path /resource01 and exact matching should be register, and then a second one with the path /resource01/ and subtree matching.

Modules
	CoAP file server
	Library for serving files from the VFS to CoAP clients.
	nanoCoAP compile configurations
	nanoCoAP-Cache implementation
	A cache implementation for nanocoap response messages.

Files
file	nanocoap.h
	nanocoap API

Data Structures
struct	coap_hdr_t
	Raw CoAP PDU header structure. More...
struct	coap_optpos_t
	CoAP option array entry. More...
struct	coap_pkt_t
	CoAP PDU parsing context structure. More...
struct	coap_resource_t
	Type for CoAP resource entry. More...
struct	coap_resource_subtree_t
	Type for CoAP resource subtrees. More...
struct	_coap_request_ctx
	CoAP resource request handler context. More...
struct	coap_block1_t
	Block1 helper struct. More...
struct	coap_block_slicer_t
	Blockwise transfer helper struct. More...

Macros
#define	COAP_FORMAT_NONE   (UINT16_MAX)
	nanoCoAP-specific value to indicate no format specified
#define	CONFIG_NANOCOAP_BLOCK_HEADER_MAX   (80)
	Maximum length of a CoAP header for a blockwise message.
#define	NANOCOAP_RESOURCE(name)    XFA_CONST(coap_resource_t, coap_resources_xfa, 0) CONCAT(coap_resource_, name) =
	CoAP XFA resource entry.
#define	CONFIG_NANOCOAP_SERVER_WELL_KNOWN_CORE   !IS_USED(MODULE_GCOAP)
	Respond to /.well-known/core to list all resources on the server.
#define	COAP_WELL_KNOWN_CORE_DEFAULT_HANDLER
	Resource definition for the default .well-known/core handler.

Typedefs
typedef struct _coap_request_ctx	coap_request_ctx_t
	Forward declaration of internal CoAP resource request handler context.
typedef ssize_t(*	coap_handler_t) (coap_pkt_t *pkt, uint8_t *buf, size_t len, coap_request_ctx_t *context)
	Resource handler type.
typedef int(*	coap_blockwise_cb_t) (void *arg, size_t offset, uint8_t *buf, size_t len, int more)
	Coap blockwise request callback descriptor.
typedef int(*	coap_request_cb_t) (void *arg, coap_pkt_t *pkt)
	Coap request callback descriptor.
typedef uint16_t	coap_method_flags_t
	Method flag type.

Functions
void	coap_request_ctx_init (coap_request_ctx_t *ctx, sock_udp_ep_t *remote)
	Initialize CoAP request context.
const char *	coap_request_ctx_get_path (const coap_request_ctx_t *ctx)
	Get resource path associated with a CoAP request.
void *	coap_request_ctx_get_context (const coap_request_ctx_t *ctx)
	Get resource context associated with a CoAP request.
uint32_t	coap_request_ctx_get_tl_type (const coap_request_ctx_t *ctx)
	Get transport the packet was received over.
const sock_udp_ep_t *	coap_request_ctx_get_remote_udp (const coap_request_ctx_t *ctx)
	Get the remote endpoint from which the request was received.
const sock_udp_ep_t *	coap_request_ctx_get_local_udp (const coap_request_ctx_t *ctx)
	Get the local endpoint on which the request has been received.
static ssize_t	coap_get_proxy_uri (coap_pkt_t *pkt, char **target)
	Convenience function for getting the packet's Proxy-Uri option.
int	coap_match_path (const coap_resource_t *resource, const uint8_t *uri)
	Checks if a CoAP resource path matches a given URI.

Functions – Header Read/Write
Includes message ID, code, type, token, CoAP version
static uint8_t *	coap_hdr_data_ptr (const coap_hdr_t *hdr)
	Get the start of data after the header.
static size_t	coap_hdr_get_token_len (const coap_hdr_t *hdr)
	Get the token length of a CoAP over UDP (DTLS) packet.
static uint8_t	coap_code (unsigned cls, unsigned detail)
	Encode given code class and code detail to raw code.
static unsigned	coap_get_code_class (const coap_pkt_t *pkt)
	Get a message's code class (3 most significant bits of code)
static unsigned	coap_get_code_detail (const coap_pkt_t *pkt)
	Get a message's code detail (5 least significant bits of code)
static unsigned	coap_get_code_decimal (const coap_pkt_t *pkt)
	Get a message's code in decimal format ((class * 100) + detail)
static unsigned	coap_get_code_raw (const coap_pkt_t *pkt)
	Get a message's raw code (class + detail)
static coap_method_t	coap_get_method (const coap_pkt_t *pkt)
	Get a request's method type.
static unsigned	coap_get_id (const coap_pkt_t *pkt)
	Get the message ID of the given CoAP packet.
static unsigned	coap_get_token_len (const coap_pkt_t *pkt)
	Get a message's token length [in byte].
static void *	coap_get_token (const coap_pkt_t *pkt)
	Get pointer to a message's token.
static unsigned	coap_get_total_len (const coap_pkt_t *pkt)
	Get the total length of a CoAP packet in the packet buffer.
static unsigned	coap_get_type (const coap_pkt_t *pkt)
	Get the message type.
static unsigned	coap_get_ver (const coap_pkt_t *pkt)
	Get the CoAP version number.
static uint8_t	coap_hdr_tkl_ext_len (const coap_hdr_t *hdr)
	Get the size of the extended Token length field (RFC 8974)
static unsigned	coap_get_total_hdr_len (const coap_pkt_t *pkt)
	Get the total header length (4-byte header + token length)
static unsigned	coap_get_response_hdr_len (const coap_pkt_t *pkt)
	Get the header length a response to the given packet will have.
static void	coap_hdr_set_code (coap_hdr_t *hdr, uint8_t code)
	Write the given raw message code to given CoAP header.
static void	coap_pkt_set_code (coap_pkt_t *pkt, uint8_t code)
	Write the given raw message code to given CoAP pkt.
static void	coap_hdr_set_type (coap_hdr_t *hdr, unsigned type)
	Set the message type for the given CoAP header.
static size_t	coap_hdr_len (const coap_hdr_t *hdr)
	Get the header length of a CoAP packet.

Functions – Options Read
Read options from a parsed packet. Packets accessed through coap_find_option or any of the coap_opt_get_* functions track their access in bit field created at parsing time to enable checking for critical options in coap_has_unprocessed_critical_options. These functions thus have a side effect, and code that calls them on critical options needs to ensure that failure to process the accessed option is propagated into failure to process the message. For example, a server helper that tries to read the If-None-Match option (which is critical) and finds it to be longer than it can process must not return as if no If-None-Match option was present, as it has already triggered the side effect of marking the option as processed.
uint8_t *	coap_find_option (coap_pkt_t *pkt, unsigned opt_num)
	Get pointer to an option field by type.
uint8_t *	coap_iterate_option (coap_pkt_t *pkt, unsigned opt_num, uint8_t **opt_pos, int *opt_len)
	Get pointer to an option field, can be called in a loop if there are multiple options with the same number.
unsigned	coap_get_content_type (coap_pkt_t *pkt)
	Get content type from packet.
unsigned	coap_get_accept (coap_pkt_t *pkt)
	Get the Accept option value from a packet if present.
int	coap_opt_get_uint (coap_pkt_t *pkt, uint16_t optnum, uint32_t *value)
	Get a uint32 option value.
ssize_t	coap_opt_get_string (coap_pkt_t *pkt, uint16_t optnum, uint8_t *target, size_t max_len, char separator)
	Read a full option as null terminated string into the target buffer.
static ssize_t	coap_get_location_path (coap_pkt_t *pkt, uint8_t *target, size_t max_len)
	Convenience function for getting the packet's LOCATION_PATH option.
static ssize_t	coap_get_location_query (coap_pkt_t *pkt, uint8_t *target, size_t max_len)
	Convenience function for getting the packet's LOCATION_QUERY option.
static ssize_t	coap_get_uri_path (coap_pkt_t *pkt, uint8_t *target)
	Convenience function for getting the packet's URI_PATH.
static ssize_t	coap_get_uri_query_string (coap_pkt_t *pkt, char *target, size_t max_len)
	Convenience function for getting the packet's URI_QUERY option.
bool	coap_find_uri_query (coap_pkt_t *pkt, const char *key, const char **value, size_t *len)
	Find a URI query option of the packet.
ssize_t	coap_opt_get_next (const coap_pkt_t *pkt, coap_optpos_t *opt, uint8_t **value, bool init_opt)
	Iterate over a packet's options.
ssize_t	coap_opt_get_opaque (coap_pkt_t *pkt, unsigned opt_num, uint8_t **value)
	Retrieve the value for an option as an opaque array of bytes.

Functions – Options for Block
Read Block1 (POST/PUT request) or Block2 (GET response) options, and generally useful functions to write block options.
void	coap_block_object_init (coap_block1_t *block, size_t blknum, size_t blksize, int more)
	Initialize a block struct from content information.
bool	coap_block_finish (coap_block_slicer_t *slicer, uint16_t option)
	Finish a block request (block1 or block2)
static bool	coap_block1_finish (coap_block_slicer_t *slicer)
	Finish a block1 request.
static bool	coap_block2_finish (coap_block_slicer_t *slicer)
	Finish a block2 response.
void	coap_block2_init (coap_pkt_t *pkt, coap_block_slicer_t *slicer)
	Initialize a block2 slicer struct for writing the payload.
void	coap_block_slicer_init (coap_block_slicer_t *slicer, size_t blknum, size_t blksize)
	Initialize a block slicer struct from content information.
size_t	coap_blockwise_put_bytes (coap_block_slicer_t *slicer, uint8_t *bufpos, const void *c, size_t len)
	Add a byte array to a block2 reply.
size_t	coap_blockwise_put_char (coap_block_slicer_t *slicer, uint8_t *bufpos, char c)
	Add a single character to a block2 reply.
int	coap_get_block (coap_pkt_t *pkt, coap_block1_t *block, uint16_t option)
	Block option getter.
static int	coap_get_block1 (coap_pkt_t *pkt, coap_block1_t *block)
	Block1 option getter.
static int	coap_get_block2 (coap_pkt_t *pkt, coap_block1_t *block)
	Block2 option getter.
int	coap_get_blockopt (coap_pkt_t *pkt, uint16_t option, uint32_t *blknum, uint8_t *szx)
	Generic block option getter.
bool	coap_has_unprocessed_critical_options (const coap_pkt_t *pkt)
	Check whether any of the packet's options that are critical.
static unsigned	coap_size2szx (unsigned len)
	Helper to encode byte size into next equal or smaller SZX value.
#define	coap_szx2size(szx)   (1U << ((szx) + 4))
	Helper to decode SZX value to size in bytes.

Functions – Options Write Packet API
Use a coap_pkt_t struct to manage writing Options to the PDU. The caller must monitor space remaining in the buffer; however, the API will not write past the end of the buffer, and returns -ENOSPC when it is full.
ssize_t	coap_opt_add_block (coap_pkt_t *pkt, coap_block_slicer_t *slicer, bool more, uint16_t option)
	Add block option in descriptive use from a slicer object.
static ssize_t	coap_opt_add_block1 (coap_pkt_t *pkt, coap_block_slicer_t *slicer, bool more)
	Add block1 option in descriptive use from a slicer object.
static ssize_t	coap_opt_add_block2 (coap_pkt_t *pkt, coap_block_slicer_t *slicer, bool more)
	Add block2 option in descriptive use from a slicer object.
ssize_t	coap_opt_add_uint (coap_pkt_t *pkt, uint16_t optnum, uint32_t value)
	Encode the given uint option into pkt.
static ssize_t	coap_opt_add_block1_control (coap_pkt_t *pkt, coap_block1_t *block)
	Encode the given block1 option in control use.
static ssize_t	coap_opt_add_block2_control (coap_pkt_t *pkt, coap_block1_t *block)
	Encode the given block2 option in control use.
static ssize_t	coap_opt_add_accept (coap_pkt_t *pkt, uint16_t format)
	Append an Accept option to the pkt buffer.
static ssize_t	coap_opt_add_format (coap_pkt_t *pkt, uint16_t format)
	Append a Content-Format option to the pkt buffer.
ssize_t	coap_opt_add_opaque (coap_pkt_t *pkt, uint16_t optnum, const void *val, size_t val_len)
	Encode the given buffer as an opaque data option into pkt.
ssize_t	coap_opt_add_uri_query2 (coap_pkt_t *pkt, const char *key, size_t key_len, const char *val, size_t val_len)
	Adds a single Uri-Query option in the form 'key=value' into pkt.
static ssize_t	coap_opt_add_uri_query (coap_pkt_t *pkt, const char *key, const char *val)
	Adds a single Uri-Query option in the form 'key=value' into pkt.
ssize_t	coap_opt_add_proxy_uri (coap_pkt_t *pkt, const char *uri)
	Adds a single Proxy-URI option into pkt.
ssize_t	coap_opt_add_chars (coap_pkt_t *pkt, uint16_t optnum, const char *chars, size_t chars_len, char separator)
	Encode the given array of characters as option(s) into pkt.
static ssize_t	coap_opt_add_string (coap_pkt_t *pkt, uint16_t optnum, const char *string, char separator)
	Encode the given string as option(s) into pkt.
static ssize_t	coap_opt_add_uri_path (coap_pkt_t *pkt, const char *path)
	Adds one or multiple Uri-Path options in the form '/path' into pkt.
static ssize_t	coap_opt_add_uri_path_buffer (coap_pkt_t *pkt, const char *path, size_t path_len)
	Adds one or multiple Uri-Path options in the form '/path' into pkt.
ssize_t	coap_opt_finish (coap_pkt_t *pkt, uint16_t flags)
	Finalizes options as required and prepares for payload.
ssize_t	coap_opt_remove (coap_pkt_t *pkt, uint16_t optnum)
	Removes an option previously added with function in the coap_opt_add_...() group.

Functions – Options Write Buffer API
Write PDU Options directly to the array of bytes for a message. The caller must provide the last option number written as well as the buffer position. The caller is primarily responsible for tracking and managing the space remaining in the buffer.
size_t	coap_opt_put_block (uint8_t *buf, uint16_t lastonum, coap_block_slicer_t *slicer, bool more, uint16_t option)
	Insert block option into buffer.
static size_t	coap_opt_put_block1 (uint8_t *buf, uint16_t lastonum, coap_block_slicer_t *slicer, bool more)
	Insert block1 option into buffer.
static size_t	coap_opt_put_block2 (uint8_t *buf, uint16_t lastonum, coap_block_slicer_t *slicer, bool more)
	Insert block2 option into buffer.
size_t	coap_opt_put_uint (uint8_t *buf, uint16_t lastonum, uint16_t onum, uint32_t value)
	Encode the given uint option into buffer.
static size_t	coap_opt_put_block1_control (uint8_t *buf, uint16_t lastonum, coap_block1_t *block)
	Insert block1 option into buffer in control usage.
static size_t	coap_opt_put_block2_control (uint8_t *buf, uint16_t lastonum, coap_block1_t *block)
	Insert block2 option into buffer in control usage.
size_t	coap_opt_put_string_with_len (uint8_t *buf, uint16_t lastonum, uint16_t optnum, const char *string, size_t len, char separator)
	Encode the given string as multi-part option into buffer.
static size_t	coap_opt_put_string (uint8_t *buf, uint16_t lastonum, uint16_t optnum, const char *string, char separator)
	Encode the given string as multi-part option into buffer.
static size_t	coap_opt_put_location_path (uint8_t *buf, uint16_t lastonum, const char *location)
	Convenience function for inserting LOCATION_PATH option into buffer.
static size_t	coap_opt_put_location_query (uint8_t *buf, uint16_t lastonum, const char *location)
	Convenience function for inserting LOCATION_QUERY option into buffer.
static size_t	coap_opt_put_uri_path (uint8_t *buf, uint16_t lastonum, const char *uri)
	Convenience function for inserting URI_PATH option into buffer.
static size_t	coap_opt_put_uri_query (uint8_t *buf, uint16_t lastonum, const char *uri)
	Convenience function for inserting URI_QUERY option into buffer.
size_t	coap_opt_put_uri_pathquery (uint8_t *buf, uint16_t *lastonum, const char *uri)
	Convenience function for inserting URI_PATH and URI_QUERY into buffer This function will automatically split path and query parameters.
static size_t	coap_opt_put_proxy_uri (uint8_t *buf, uint16_t lastonum, const char *uri)
	Convenience function for inserting PROXY_URI option into buffer.
size_t	coap_put_block1_ok (uint8_t *pkt_pos, coap_block1_t *block1, uint16_t lastonum)
	Insert block1 option into buffer (from coap_block1_t)
size_t	coap_put_option (uint8_t *buf, uint16_t lastonum, uint16_t onum, const void *odata, size_t olen)
	Insert a CoAP option into buffer.
static size_t	coap_put_option_block1 (uint8_t *buf, uint16_t lastonum, unsigned blknum, unsigned szx, int more)
	Insert block1 option into buffer.
static size_t	coap_put_option_ct (uint8_t *buf, uint16_t lastonum, uint16_t content_type)
	Insert content type option into buffer.

Functions – Messaging
Functions to support sending and receiving messages.
ssize_t	coap_block2_build_reply (coap_pkt_t *pkt, unsigned code, uint8_t *rbuf, unsigned rlen, unsigned payload_len, coap_block_slicer_t *slicer)
	Build reply to CoAP block2 request.
ssize_t	coap_build_hdr (coap_hdr_t *hdr, unsigned type, const void *token, size_t token_len, unsigned code, uint16_t id)
	Builds a CoAP header.
ssize_t	coap_build_reply (coap_pkt_t *pkt, unsigned code, uint8_t *rbuf, unsigned rlen, unsigned payload_len)
	Build reply to CoAP request.
ssize_t	coap_build_empty_ack (coap_pkt_t *pkt, coap_hdr_t *ack)
	Build empty reply to CoAP request.
ssize_t	coap_handle_req (coap_pkt_t *pkt, uint8_t *resp_buf, unsigned resp_buf_len, coap_request_ctx_t *ctx)
	Handle incoming CoAP request.
ssize_t	coap_tree_handler (coap_pkt_t *pkt, uint8_t *resp_buf, unsigned resp_buf_len, coap_request_ctx_t *ctx, const coap_resource_t *resources, size_t resources_numof)
	Pass a coap request to a matching handler.
ssize_t	coap_subtree_handler (coap_pkt_t *pkt, uint8_t *resp_buf, size_t resp_buf_len, coap_request_ctx_t *context)
	Generic coap subtree handler.
static coap_method_flags_t	coap_method2flag (unsigned code)
	Convert message code (request method) into a corresponding bit field.
int	coap_parse (coap_pkt_t *pkt, uint8_t *buf, size_t len)
	Parse a CoAP PDU.
void	coap_pkt_init (coap_pkt_t *pkt, uint8_t *buf, size_t len, size_t header_len)
	Initialize a packet struct, to build a message buffer.
static void	coap_payload_advance_bytes (coap_pkt_t *pkt, size_t len)
	Advance the payload pointer.
ssize_t	coap_payload_put_bytes (coap_pkt_t *pkt, const void *data, size_t len)
	Add payload data to the CoAP request.
ssize_t	coap_payload_put_char (coap_pkt_t *pkt, char c)
	Add a single character to the payload data of the CoAP request.
ssize_t	coap_build_reply_header (coap_pkt_t *pkt, unsigned code, void *buf, size_t len, int ct, void **payload, size_t *payload_len_max)
	Create CoAP reply header (convenience function)
ssize_t	coap_reply_simple (coap_pkt_t *pkt, unsigned code, uint8_t *buf, size_t len, unsigned ct, const void *payload, size_t payload_len)
	Create CoAP reply (convenience function)
ssize_t	coap_well_known_core_default_handler (coap_pkt_t *pkt, uint8_t *buf, size_t len, coap_request_ctx_t *context)
	Reference to the default .well-known/core handler defined by the application.

Functions – gcoap specific
static bool	coap_has_observe (coap_pkt_t *pkt)
	Identifies a packet containing an observe option.
static void	coap_clear_observe (coap_pkt_t *pkt)
	Clears the observe option value from a packet.
static uint32_t	coap_get_observe (coap_pkt_t *pkt)
	Get the value of the observe option from the given packet.

nanoCoAP specific CoAP method flags used in coap_handlers array
#define	COAP_GET   (0x01)
#define	COAP_POST   (0x02)
#define	COAP_PUT   (0x04)
#define	COAP_DELETE   (0x08)
#define	COAP_FETCH   (0x10)
#define	COAP_PATCH   (0x20)
#define	COAP_IPATCH   (0x40)
#define	COAP_IGNORE   (0xFF)
	For situations where the method is not important.
#define	COAP_MATCH_SUBTREE   (0x8000)
	Path is considered as a prefix when matching.

coap_opt_finish() flag parameter values
Directs packet/buffer updates when user finishes adding options
#define	COAP_OPT_FINISH_NONE   (0x0000)
	no special handling required
#define	COAP_OPT_FINISH_PAYLOAD   (0x0001)
	expect a payload to follow

Macro Definition Documentation

COAP_DELETE

#define COAP_DELETE   (0x08)

Definition at line 123 of file nanocoap.h.

COAP_FETCH

#define COAP_FETCH   (0x10)

Definition at line 124 of file nanocoap.h.

COAP_FORMAT_NONE

#define COAP_FORMAT_NONE   (UINT16_MAX)

nanoCoAP-specific value to indicate no format specified

Definition at line 136 of file nanocoap.h.

COAP_GET

#define COAP_GET   (0x01)

Definition at line 120 of file nanocoap.h.

COAP_IGNORE

#define COAP_IGNORE   (0xFF)

For situations where the method is not important.

Definition at line 128 of file nanocoap.h.

COAP_IPATCH

#define COAP_IPATCH   (0x40)

Definition at line 126 of file nanocoap.h.

COAP_MATCH_SUBTREE

#define COAP_MATCH_SUBTREE   (0x8000)

Path is considered as a prefix when matching.

Definition at line 130 of file nanocoap.h.

COAP_OPT_FINISH_NONE

#define COAP_OPT_FINISH_NONE   (0x0000)

no special handling required

Definition at line 193 of file nanocoap.h.

COAP_OPT_FINISH_PAYLOAD

#define COAP_OPT_FINISH_PAYLOAD   (0x0001)

expect a payload to follow

Definition at line 195 of file nanocoap.h.

COAP_PATCH

#define COAP_PATCH   (0x20)

Definition at line 125 of file nanocoap.h.

COAP_POST

#define COAP_POST   (0x02)

Definition at line 121 of file nanocoap.h.

COAP_PUT

#define COAP_PUT   (0x04)

Definition at line 122 of file nanocoap.h.

coap_szx2size

#define coap_szx2size

(

szx

)

(1U << ((szx) + 4))

Helper to decode SZX value to size in bytes.

Parameters

[in]

szx

SZX value to decode

Returns

SZX value decoded to bytes

Definition at line 1272 of file nanocoap.h.

COAP_WELL_KNOWN_CORE_DEFAULT_HANDLER

#define COAP_WELL_KNOWN_CORE_DEFAULT_HANDLER

Value:

    { \
        .path = "/.well-known/core", \
        .methods = COAP_GET, \
        .handler = coap_well_known_core_default_handler \
    }

Resource definition for the default .well-known/core handler.

Definition at line 2375 of file nanocoap.h.

CONFIG_NANOCOAP_BLOCK_HEADER_MAX

#define CONFIG_NANOCOAP_BLOCK_HEADER_MAX   (80)

Maximum length of a CoAP header for a blockwise message.

      Value obtained experimentally when using SUIT

Definition at line 183 of file nanocoap.h.

CONFIG_NANOCOAP_SERVER_WELL_KNOWN_CORE

#define CONFIG_NANOCOAP_SERVER_WELL_KNOWN_CORE   !IS_USED(MODULE_GCOAP)

Respond to /.well-known/core to list all resources on the server.

Definition at line 2310 of file nanocoap.h.

NANOCOAP_RESOURCE

#define NANOCOAP_RESOURCE

(

name

)

XFA_CONST(coap_resource_t, coap_resources_xfa, 0) CONCAT(coap_resource_, name) =

CoAP XFA resource entry.

Parameters

name	internal name of the resource entry, must be unique

Definition at line 434 of file nanocoap.h.

Typedef Documentation

coap_blockwise_cb_t

typedef int(* coap_blockwise_cb_t) (void *arg, size_t offset, uint8_t *buf, size_t len, int more)

Coap blockwise request callback descriptor.

Parameters

[in]	arg	Pointer to be passed as arguments to the callback
[in]	offset	Offset of received data
[in]	buf	Pointer to the received data
[in]	len	Length of the received data
[in]	more	-1 for no option, 0 for last block, 1 for more blocks

Returns

>=0 on success

<0 on error

Definition at line 287 of file nanocoap.h.

coap_handler_t

typedef ssize_t(* coap_handler_t) (coap_pkt_t *pkt, uint8_t *buf, size_t len, coap_request_ctx_t *context)

Resource handler type.

Functions that implement this must be prepared to be called multiple times for the same request, as the server implementations do not perform message deduplication. That optimization is described in the CoAP specification.

This should be trivial for requests of the GET, PUT, DELETE, FETCH and iPATCH methods, as they are defined as idempotent methods in CoAP.

For POST, PATCH and other non-idempotent methods, this is an additional requirement introduced by the contract of this type.

Parameters

[in]	pkt	The request packet
[out]	buf	Buffer for the response
[in]	len	Size of the response buffer
[in]	context	Request context

Returns

Number of response bytes written on success Negative error on failure

Definition at line 272 of file nanocoap.h.

coap_method_flags_t

typedef uint16_t coap_method_flags_t

Method flag type.

Must be large enough to contain all CoAP method flags

Definition at line 306 of file nanocoap.h.

coap_request_cb_t

typedef int(* coap_request_cb_t) (void *arg, coap_pkt_t *pkt)

Coap request callback descriptor.

Parameters

[in]	arg	Pointer to be passed as arguments to the callback
[in]	pkt	The received CoAP response. Buffers point to network stack internal memory.

Returns

>=0 on success

<0 on error

Definition at line 299 of file nanocoap.h.

coap_request_ctx_t

typedef struct _coap_request_ctx coap_request_ctx_t

Forward declaration of internal CoAP resource request handler context.

Definition at line 248 of file nanocoap.h.

Function Documentation

coap_block1_finish()

static bool coap_block1_finish ( coap_block_slicer_t *  slicer )

inlinestatic

Finish a block1 request.

This function finalizes the block1 response header

Checks whether the more bit should be set in the block1 option and sets/clears it if required. Doesn't return the number of bytes, as this function overwrites bytes in the packet rather than adding new.

Parameters

[in]

slicer

Preallocated slicer struct to use

Returns

true if the more bit is set in the block option

false if the more bit is not set the block option

Definition at line 1097 of file nanocoap.h.

coap_block2_build_reply()

ssize_t coap_block2_build_reply	(	coap_pkt_t *	pkt,
		unsigned	code,
		uint8_t *	rbuf,
		unsigned	rlen,
		unsigned	payload_len,
		coap_block_slicer_t *	slicer
	)

Build reply to CoAP block2 request.

This function can be used to create a reply to a CoAP block2 request packet. In addition to coap_build_reply, this function checks the block2 option and returns an error message to the client if necessary.

Parameters

[in]	pkt	packet to reply to
[in]	code	reply code (e.g., COAP_CODE_204)
[out]	rbuf	buffer to write reply to
[in]	rlen	size of rbuf
[in]	payload_len	length of payload
[in]	slicer	slicer to use

Warning

Use coap_get_response_hdr_len to determine the size of the header this will write.

Returns

size of reply packet on success

<0 on error

coap_block2_finish()

static bool coap_block2_finish ( coap_block_slicer_t *  slicer )

inlinestatic

Finish a block2 response.

This function finalizes the block2 response header

Checks whether the more bit should be set in the block2 option and sets/clears it if required. Doesn't return the number of bytes, as this function overwrites bytes in the packet rather than adding new.

Parameters

[in]

slicer

Preallocated slicer struct to use

Returns

true if the more bit is set in the block option

false if the more bit is not set the block option

Definition at line 1116 of file nanocoap.h.

coap_block2_init()

void coap_block2_init	(	coap_pkt_t *	pkt,
		coap_block_slicer_t *	slicer
	)

Initialize a block2 slicer struct for writing the payload.

This function determines the size of the response payload based on the size requested by the client in pkt.

Parameters

[in]	pkt	packet to work on
[out]	slicer	Preallocated slicer struct to fill

coap_block_finish()

bool coap_block_finish	(	coap_block_slicer_t *	slicer,
		uint16_t	option
	)

Finish a block request (block1 or block2)

This function finalizes the block response header

Checks whether the more bit should be set in the block option and sets/clears it if required. Doesn't return the number of bytes, as this function overwrites bytes in the packet rather than adding new.

Parameters

[in]	slicer	Preallocated slicer struct to use
[in]	option	option number (block1 or block2)

Returns

true if the more bit is set in the block option

false if the more bit is not set the block option

coap_block_object_init()

void coap_block_object_init	(	coap_block1_t *	block,
		size_t	blknum,
		size_t	blksize,
		int	more
	)

Initialize a block struct from content information.

Parameters

[out]	block	block struct to initialize
[in]	blknum	offset from the beginning of content, in terms of blksize byte blocks
[in]	blksize	size of each block; must be a power of 2 between 16 and 2 raised to CONFIG_NANOCOAP_BLOCK_SIZE_EXP_MAX
[in]	more	more blocks? use 1 if yes; 0 if no or unknown

coap_block_slicer_init()

void coap_block_slicer_init	(	coap_block_slicer_t *	slicer,
		size_t	blknum,
		size_t	blksize
	)

Initialize a block slicer struct from content information.

Parameters

[out]	slicer	slicer struct to initialize
[in]	blknum	offset from the beginning of content, in terms of blksize byte blocks
[in]	blksize	size of each block; must be a power of 2 between 16 and 2 raised to CONFIG_NANOCOAP_BLOCK_SIZE_EXP_MAX

coap_blockwise_put_bytes()

size_t coap_blockwise_put_bytes	(	coap_block_slicer_t *	slicer,
		uint8_t *	bufpos,
		const void *	c,
		size_t	len
	)

Add a byte array to a block2 reply.

This function is used to add an array of bytes to a CoAP block2 reply. it checks which parts of the string should be added to the reply and ignores parts that are outside the current block2 request.

Parameters

[in]	slicer	slicer to use
[in]	bufpos	pointer to the current payload buffer position
[in]	c	byte array to copy
[in]	len	length of the byte array

Returns

Number of bytes written to bufpos

coap_blockwise_put_char()

size_t coap_blockwise_put_char	(	coap_block_slicer_t *	slicer,
		uint8_t *	bufpos,
		char	c
	)

Add a single character to a block2 reply.

This function is used to add single characters to a CoAP block2 reply. It checks whether the character should be added to the buffer and ignores it when the character is outside the current block2 request.

Parameters

[in]	slicer	slicer to use
[in]	bufpos	pointer to the current payload buffer position
[in]	c	character to write

Returns

Number of bytes written to bufpos

coap_build_empty_ack()

ssize_t coap_build_empty_ack	(	coap_pkt_t *	pkt,
		coap_hdr_t *	ack
	)

Build empty reply to CoAP request.

This function can be used to create an empty ACK so that a later, separate response can be sent independently.

If the request was non-confirmable, this will generate nothing.

Parameters

[in]	pkt	packet to reply to
[out]	ack	buffer to write reply to

Returns

size of reply packet on success

-ENOSPC if rbuf too small

coap_build_hdr()

ssize_t coap_build_hdr	(	coap_hdr_t *	hdr,
		unsigned	type,
		const void *	token,
		size_t	token_len,
		unsigned	code,
		uint16_t	id
	)

Builds a CoAP header.

Caller must ensure hdr can hold the header and the full token!

Parameters

[out]	hdr	hdr to fill
[in]	type	CoAP packet type (e.g., COAP_TYPE_CON, ...)
[in]	token	token
[in]	token_len	length of token
[in]	code	CoAP code (e.g., COAP_CODE_204, ...)
[in]	id	CoAP request id

Precondition

token is either not overlapping with the memory buffer hdr points to, or is already at the right offset (e.g. when building the response inside the buffer the contained the request).

Returns

length of resulting header

coap_build_reply()

ssize_t coap_build_reply	(	coap_pkt_t *	pkt,
		unsigned	code,
		uint8_t *	rbuf,
		unsigned	rlen,
		unsigned	payload_len
	)

Build reply to CoAP request.

This function can be used to create a reply to any CoAP request packet. It will create the reply packet header based on parameters from the request (e.g., id, token).

Passing a non-zero payload_len will ensure the payload fits into the buffer along with the header. For this validation, payload_len must include any options, the payload marker, as well as the payload proper.

Parameters

[in]	pkt	packet to reply to
[in]	code	reply code (e.g., COAP_CODE_204)
[out]	rbuf	buffer to write reply to
[in]	rlen	size of rbuf
[in]	payload_len	length of payload

Returns

size of reply packet on success

         Note that this size can be severely shortened if due to a No-Response option there
         is only an empty ACK to be sent back. The caller may just continue populating the
         payload (the space was checked to suffice), but may also skip that needless step
         if the returned length is less than the requested payload length.

0 if no response should be sent due to a No-Response option in the request

<0 on error

-ENOSPC if rbuf too small

coap_build_reply_header()

ssize_t coap_build_reply_header	(	coap_pkt_t *	pkt,
		unsigned	code,
		void *	buf,
		size_t	len,
		int	ct,
		void **	payload,
		size_t *	payload_len_max
	)

Create CoAP reply header (convenience function)

This function generates the reply CoAP header and sets the payload pointer inside the response buffer to point to the start of the payload, so that it can be written directly after the header.

Parameters

[in]	pkt	packet to reply to
[in]	code	reply code (e.g., COAP_CODE_204)
[out]	buf	buffer to write reply to
[in]	len	size of buf
[in]	ct	content type of payload if ct < 0 this will be ignored
[out]	payload	Will be set to the start of the payload inside buf. May be set to NULL if no payload response is wanted (no-reply option)
[out]	payload_len_max	max length of payload left in buf

Returns

size of reply header on success

0 if no reply should be sent

<0 on error

-ENOSPC if buf too small

coap_clear_observe()

static void coap_clear_observe ( coap_pkt_t *  pkt )

inlinestatic

Clears the observe option value from a packet.

Parameters

[in]

pkt

CoAP packet

Definition at line 2353 of file nanocoap.h.

coap_code()

static uint8_t coap_code ( unsigned  cls, unsigned  detail  )

inlinestatic

Encode given code class and code detail to raw code.

Parameters

[in]	cls	message code class
[in]	detail	message code detail

Returns

raw message code

Definition at line 466 of file nanocoap.h.

coap_find_option()

uint8_t * coap_find_option	(	coap_pkt_t *	pkt,
		unsigned	opt_num
	)

Get pointer to an option field by type.

Parameters

[in]	pkt	packet to work on
[in]	opt_num	the option number to search for

Returns

pointer to the option data NULL if option number was not found

coap_find_uri_query()

bool coap_find_uri_query	(	coap_pkt_t *	pkt,
		const char *	key,
		const char **	value,
		size_t *	len
	)

Find a URI query option of the packet.

This function searches for a query option of the form "?key=value" and would, when present, return the pointer to "value" when searching for "key".

Parameters

[in]	pkt	pkt to work on
[in]	key	key string to look for
[out]	value	found value if present, may be NULL
[out]	len	length of value if present, may be NULL if value is NULL

Returns

true if the key was found, false if not

coap_get_accept()

unsigned coap_get_accept

(

coap_pkt_t *

pkt

)

Get the Accept option value from a packet if present.

Parameters

[in]

pkt

packet to work on

Returns

the packet's Accept option value if included, COAP_FORMAT_NONE otherwise

coap_get_block()

int coap_get_block	(	coap_pkt_t *	pkt,
		coap_block1_t *	block,
		uint16_t	option
	)

Block option getter.

This function gets a CoAP packet's block option and parses it into a helper structure.

If no block option is present in pkt, the values in block will be initialized with zero. That implies both block->offset and block->more are also valid in that case, as packet with offset==0 and more==0 means it contains all the payload for the corresponding request.

Parameters

[in]	pkt	pkt to work on
[out]	block	ptr to preallocated coap_block1_t structure
[in]	option	block1 or block2

Returns

0 if block option not present

1 if structure has been filled

coap_get_block1()

static int coap_get_block1 ( coap_pkt_t *  pkt, coap_block1_t *  block  )

inlinestatic

Block1 option getter.

This function gets a CoAP packet's block1 option and parses it into a helper structure.

If no block1 option is present in pkt, the values in block1 will be initialized with zero. That implies both block1->offset and block1->more are also valid in that case, as packet with offset==0 and more==0 means it contains all the payload for the corresponding request.

Parameters

[in]	pkt	pkt to work on
[out]	block	ptr to preallocated coap_block1_t structure

Returns

0 if block1 option not present

1 if structure has been filled

Definition at line 1213 of file nanocoap.h.

coap_get_block2()

static int coap_get_block2 ( coap_pkt_t *  pkt, coap_block1_t *  block  )

inlinestatic

Block2 option getter.

Parameters

[in]	pkt	pkt to work on
[out]	block	ptr to preallocated coap_block1_t structure

Returns

0 if block2 option not present

1 if structure has been filled

Definition at line 1227 of file nanocoap.h.

coap_get_blockopt()

int coap_get_blockopt	(	coap_pkt_t *	pkt,
		uint16_t	option,
		uint32_t *	blknum,
		uint8_t *	szx
	)

Generic block option getter.

Parameters

[in]	pkt	pkt to work on
[in]	option	actual block option number to get
[out]	blknum	block number
[out]	szx	SZX value

Returns

-1 if option not found

0 if more flag is not set

1 if more flag is set

coap_get_code_class()

static unsigned coap_get_code_class ( const coap_pkt_t *  pkt )

inlinestatic

Get a message's code class (3 most significant bits of code)

Parameters

[in]

pkt

CoAP packet

Returns

message code class

Definition at line 478 of file nanocoap.h.

coap_get_code_decimal()

static unsigned coap_get_code_decimal ( const coap_pkt_t *  pkt )

inlinestatic

Get a message's code in decimal format ((class * 100) + detail)

Parameters

[in]

pkt

CoAP packet

Returns

message code in decimal format

Definition at line 502 of file nanocoap.h.

coap_get_code_detail()

static unsigned coap_get_code_detail ( const coap_pkt_t *  pkt )

inlinestatic

Get a message's code detail (5 least significant bits of code)

Parameters

[in]

pkt

CoAP packet

Returns

message code detail

Definition at line 490 of file nanocoap.h.

coap_get_code_raw()

static unsigned coap_get_code_raw ( const coap_pkt_t *  pkt )

inlinestatic

Get a message's raw code (class + detail)

Parameters

[in]

pkt

CoAP packet

Returns

raw message code

Definition at line 514 of file nanocoap.h.

coap_get_content_type()

unsigned coap_get_content_type

(

coap_pkt_t *

pkt

)

Get content type from packet.

Parameters

[in]

pkt

packet to work on

Returns

the packet's content type value if included, COAP_FORMAT_NONE otherwise

coap_get_id()

static unsigned coap_get_id ( const coap_pkt_t *  pkt )

inlinestatic

Get the message ID of the given CoAP packet.

Parameters

[in]

pkt

CoAP packet

Returns

message ID

Definition at line 538 of file nanocoap.h.

coap_get_location_path()

static ssize_t coap_get_location_path ( coap_pkt_t *  pkt, uint8_t *  target, size_t  max_len  )

inlinestatic

Convenience function for getting the packet's LOCATION_PATH option.

This function decodes the pkt's LOCATION_PATH option into a '/'-separated and '\0'-terminated string.

Caller must ensure target can hold at least 2 bytes!

Parameters

[in]	pkt	pkt to work on
[out]	target	buffer for location path
[in]	max_len	size of target in bytes

Returns

-ENOSPC if URI option is larger than max_len

nr of bytes written to target (including '\0')

Definition at line 892 of file nanocoap.h.

coap_get_location_query()

static ssize_t coap_get_location_query ( coap_pkt_t *  pkt, uint8_t *  target, size_t  max_len  )

inlinestatic

Convenience function for getting the packet's LOCATION_QUERY option.

This function decodes the pkt's LOCATION_PATH option into a '&'-separated and '\0'-terminated string.

Caller must ensure target can hold at least 2 bytes!

Parameters

[in]	pkt	pkt to work on
[out]	target	buffer for location path
[in]	max_len	size of target in bytes

Returns

-ENOSPC if URI option is larger than max_len

nr of bytes written to target (including '\0')

Definition at line 914 of file nanocoap.h.

coap_get_method()

static coap_method_t coap_get_method ( const coap_pkt_t *  pkt )

inlinestatic

Get a request's method type.

Parameters

[in]

pkt

CoAP request packet

Returns

request method type

Definition at line 526 of file nanocoap.h.

coap_get_observe()

static uint32_t coap_get_observe ( coap_pkt_t *  pkt )

inlinestatic

Get the value of the observe option from the given packet.

Parameters

[in]

pkt

CoAP packet

Returns

value of the observe option

Definition at line 2365 of file nanocoap.h.

coap_get_proxy_uri()

static ssize_t coap_get_proxy_uri ( coap_pkt_t *  pkt, char **  target  )

inlinestatic

Convenience function for getting the packet's Proxy-Uri option.

Parameters

[in]	pkt	pkt to work on
[out]	target	pointer to the PROXY_URI in pkt

Precondition

((pkt != NULL) && (target != NULL))

Returns

length of the Proxy-Uri option

-ENOENT if Proxy-Uri option not found

-EINVAL if Proxy-Uri option cannot be parsed

Definition at line 1041 of file nanocoap.h.

coap_get_response_hdr_len()

static unsigned coap_get_response_hdr_len ( const coap_pkt_t *  pkt )

inlinestatic

Get the header length a response to the given packet will have.

Parameters

[in]

pkt

CoAP packet to reply to

Returns

Length of the response header including token excluding CoAP options and any payload marker

Note

The main use case is the use of coap_block2_build_reply, which is building the CoAP header of the response after options and payload have been added.

Definition at line 676 of file nanocoap.h.

coap_get_token()

static void * coap_get_token ( const coap_pkt_t *  pkt )

inlinestatic

Get pointer to a message's token.

Parameters

[in]

pkt

CoAP packet

Returns

pointer to the token position

Definition at line 565 of file nanocoap.h.

coap_get_token_len()

static unsigned coap_get_token_len ( const coap_pkt_t *  pkt )

inlinestatic

Get a message's token length [in byte].

If the nanocoap_token_ext module is enabled, this will include the extended token length.

Parameters

[in]

pkt

CoAP packet

Returns

length of token in the given message (0-8 byte)

Definition at line 553 of file nanocoap.h.

coap_get_total_hdr_len()

static unsigned coap_get_total_hdr_len ( const coap_pkt_t *  pkt )

inlinestatic

Get the total header length (4-byte header + token length)

Parameters

[in]

pkt

CoAP packet

Returns

total header length

Definition at line 659 of file nanocoap.h.

coap_get_total_len()

static unsigned coap_get_total_len ( const coap_pkt_t *  pkt )

inlinestatic

Get the total length of a CoAP packet in the packet buffer.

Note

This does not include possible payload snips.

Parameters

[in]

pkt

CoAP packet

Returns

total CoAP length

Definition at line 579 of file nanocoap.h.

coap_get_type()

static unsigned coap_get_type ( const coap_pkt_t *  pkt )

inlinestatic

Get the message type.

Parameters

[in]

pkt

CoAP packet

Returns

COAP_TYPE_CON

COAP_TYPE_NON

COAP_TYPE_ACK

COAP_TYPE_RST

Definition at line 594 of file nanocoap.h.

coap_get_uri_path()

static ssize_t coap_get_uri_path ( coap_pkt_t *  pkt, uint8_t *  target  )

inlinestatic

Convenience function for getting the packet's URI_PATH.

This function decodes the pkt's URI option into a "/"-separated and '\0'-terminated string.

Caller must ensure target can hold at least CONFIG_NANOCOAP_URI_MAX bytes!

Parameters

[in]	pkt	pkt to work on
[out]	target	buffer for target URI

Returns

-ENOSPC if URI option is larger than CONFIG_NANOCOAP_URI_MAX

nr of bytes written to target (including '\0')

Definition at line 935 of file nanocoap.h.

coap_get_uri_query_string()

static ssize_t coap_get_uri_query_string ( coap_pkt_t *  pkt, char *  target, size_t  max_len  )

inlinestatic

Convenience function for getting the packet's URI_QUERY option.

This function decodes the pkt's URI_QUERY option into a "&"-separated and '\0'-terminated string.

Parameters

[in]	pkt	pkt to work on
[out]	target	buffer for target URI
[in]	max_len	size of target in bytes

Returns

-ENOSPC if URI option is larger than max_len

nr of bytes written to target (including '\0')

Definition at line 954 of file nanocoap.h.

coap_get_ver()

static unsigned coap_get_ver ( const coap_pkt_t *  pkt )

inlinestatic

Get the CoAP version number.

Parameters

[in]

pkt

CoAP packet

Returns

CoAP version number

Definition at line 606 of file nanocoap.h.

coap_handle_req()

ssize_t coap_handle_req	(	coap_pkt_t *	pkt,
		uint8_t *	resp_buf,
		unsigned	resp_buf_len,
		coap_request_ctx_t *	ctx
	)

Handle incoming CoAP request.

This function will find the correct handler, call it and write the reply into resp_buf.

Parameters

[in]	pkt	pointer to (parsed) CoAP packet
[out]	resp_buf	buffer for response
[in]	resp_buf_len	size of response buffer
[in]	ctx	CoAP request context information

Returns

size of reply packet on success

<0 on error

coap_has_observe()

static bool coap_has_observe ( coap_pkt_t *  pkt )

inlinestatic

Identifies a packet containing an observe option.

Parameters

[in]

pkt

CoAP packet

Returns

true if observe value is set

false if not

Definition at line 2343 of file nanocoap.h.

coap_has_unprocessed_critical_options()

bool coap_has_unprocessed_critical_options

(

const coap_pkt_t *

pkt

)

Check whether any of the packet's options that are critical.

(i.e must be understood by the receiver, indicated by a 1 in the option number's least significant bit) were not accessed since the packet was parsed.

Call this in a server on requests after all their option processing has happened, and stop processing the request if it returns true, returning a 4.02 Bad Option response.

Call this in a client when receiving a response before acting on it; consider the response unprocessable if it returns true.

Parameters

[in]

pkt

pkt to work on

Returns

true if any of the options marked as critical at parse time have not been accessed.

false if there are no critical options, or all have been accessed.

coap_hdr_data_ptr()

static uint8_t * coap_hdr_data_ptr ( const coap_hdr_t *  hdr )

inlinestatic

Get the start of data after the header.

Parameters

[in]

hdr

Header of CoAP packet in contiguous memory

Returns

pointer to first byte after the header

Definition at line 647 of file nanocoap.h.

coap_hdr_get_token_len()

static size_t coap_hdr_get_token_len ( const coap_hdr_t *  hdr )

inlinestatic

Get the token length of a CoAP over UDP (DTLS) packet.

Parameters

[in]

hdr

CoAP over UDP header

Returns

The size of the token in bytes

Warning

This API is super goofy. It assumes that the packet is valid and will read more than sizeof(*hdr) into the data hdr points to while crossing fingers hard.

Deprecated:

This function was introduced to keep legacy code alive. Introducing new callers should be avoided. In the RX path an coap_pkt_t will be available, so that you can call coap_get_token instead. In the TX path the token was added by us, so we really should know.

Definition at line 735 of file nanocoap.h.

coap_hdr_len()

static size_t coap_hdr_len ( const coap_hdr_t *  hdr )

inlinestatic

Get the header length of a CoAP packet.

Warning

This API is super goofy. It assumes that the packet is valid and will read more than sizeof(*hdr) into the data hdr points to while crossing fingers hard.

Deprecated:

This function was introduced to keep legacy code alive. Introducing new callers should be avoided. In the RX path an coap_pkt_t will be available, so that you can call coap_get_total_hdr_len instead. In the TX path the header was created by us (e.g. using coap_build_hdr which returns the header size), so we really should know already.

Definition at line 774 of file nanocoap.h.

coap_hdr_set_code()

static void coap_hdr_set_code ( coap_hdr_t *  hdr, uint8_t  code  )

inlinestatic

Write the given raw message code to given CoAP header.

Parameters

[out]	hdr	CoAP header to write to
[in]	code	raw message code

Definition at line 687 of file nanocoap.h.

coap_hdr_set_type()

static void coap_hdr_set_type ( coap_hdr_t *  hdr, unsigned  type  )

inlinestatic

Set the message type for the given CoAP header.

Precondition

(type := [0-3])

Parameters

[out]	hdr	CoAP header to write
[in]	type	message type as integer value [0-3]

Definition at line 711 of file nanocoap.h.

coap_hdr_tkl_ext_len()

static uint8_t coap_hdr_tkl_ext_len ( const coap_hdr_t *  hdr )

inlinestatic

Get the size of the extended Token length field (RFC 8974)

Note

This requires the nanocoap_token_ext module to be enabled

Parameters

[in]

hdr

CoAP header

Returns

number of bytes used for extended token length

Definition at line 621 of file nanocoap.h.

coap_iterate_option()

uint8_t * coap_iterate_option	(	coap_pkt_t *	pkt,
		unsigned	opt_num,
		uint8_t **	opt_pos,
		int *	opt_len
	)

Get pointer to an option field, can be called in a loop if there are multiple options with the same number.

Parameters

[in]	pkt	packet to work on
[in]	opt_num	the option number to search for
[out]	opt_pos	opaque, must be set to NULL on first call
[out]	opt_len	size of the current option data

Returns

pointer to the option data NULL if option number was not found

coap_match_path()

int coap_match_path	(	const coap_resource_t *	resource,
		const uint8_t *	uri
	)

Checks if a CoAP resource path matches a given URI.

Builds on strcmp() with rules specific to URI path matching

Note

This function is not intended for application use.

coap_method2flag()

static coap_method_flags_t coap_method2flag ( unsigned  code )

inlinestatic

Convert message code (request method) into a corresponding bit field.

Parameters

[in]

code

request code denoting the request method

Returns

bit field corresponding to the given request method

Definition at line 2146 of file nanocoap.h.

coap_opt_add_accept()

static ssize_t coap_opt_add_accept ( coap_pkt_t *  pkt, uint16_t  format  )

inlinestatic

Append an Accept option to the pkt buffer.

Postcondition

pkt.payload advanced to first byte after option

pkt.payload_len reduced by option length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	format	COAP_FORMAT_xxx to accept

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options or insufficient buffer space

Definition at line 1434 of file nanocoap.h.

coap_opt_add_block()

ssize_t coap_opt_add_block	(	coap_pkt_t *	pkt,
		coap_block_slicer_t *	slicer,
		bool	more,
		uint16_t	option
	)

Add block option in descriptive use from a slicer object.

When calling this function to initialize a packet with a block option, the more flag must be set to prevent the creation of an option with a length too small to contain the size bit.

Postcondition

pkt.payload advanced to first byte after option

pkt.payload_len reduced by option length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	slicer	coap blockwise slicer helper struct
[in]	more	more flag (1 or 0)
[in]	option	option number (block1 or block2)

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options or insufficient buffer space

coap_opt_add_block1()

static ssize_t coap_opt_add_block1 ( coap_pkt_t *  pkt, coap_block_slicer_t *  slicer, bool  more  )

inlinestatic

Add block1 option in descriptive use from a slicer object.

When calling this function to initialize a packet with a block option, the more flag must be set to prevent the creation of an option with a length too small to contain the size bit.

Postcondition

pkt.payload advanced to first byte after option

pkt.payload_len reduced by option length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	slicer	coap blockwise slicer helper struct
[in]	more	more flag (1 or 0)

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options or insufficient buffer space

Definition at line 1339 of file nanocoap.h.

coap_opt_add_block1_control()

static ssize_t coap_opt_add_block1_control ( coap_pkt_t *  pkt, coap_block1_t *  block  )

inlinestatic

Encode the given block1 option in control use.

Postcondition

pkt.payload advanced to first byte after option

pkt.payload_len reduced by option length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	block	block to encode

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options or insufficient buffer space

Definition at line 1397 of file nanocoap.h.

coap_opt_add_block2()

static ssize_t coap_opt_add_block2 ( coap_pkt_t *  pkt, coap_block_slicer_t *  slicer, bool  more  )

inlinestatic

Add block2 option in descriptive use from a slicer object.

When calling this function to initialize a packet with a block option, the more flag must be set to prevent the creation of an option with a length too small to contain the size bit.

Postcondition

pkt.payload advanced to first byte after option

pkt.payload_len reduced by option length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	slicer	coap blockwise slicer helper struct
[in]	more	more flag (1 or 0)

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options or insufficient buffer space

Definition at line 1363 of file nanocoap.h.

coap_opt_add_block2_control()

static ssize_t coap_opt_add_block2_control ( coap_pkt_t *  pkt, coap_block1_t *  block  )

inlinestatic

Encode the given block2 option in control use.

Postcondition

pkt.payload advanced to first byte after option

pkt.payload_len reduced by option length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	block	block to encode

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options or insufficient buffer space

Definition at line 1415 of file nanocoap.h.

coap_opt_add_chars()

ssize_t coap_opt_add_chars	(	coap_pkt_t *	pkt,
		uint16_t	optnum,
		const char *	chars,
		size_t	chars_len,
		char	separator
	)

Encode the given array of characters as option(s) into pkt.

Use separator to split array of characters into multiple options.

Postcondition

pkt.payload advanced to first byte after option(s)

pkt.payload_len reduced by option(s) length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	optnum	option number to use
[in]	chars	array of characters to encode as option
[in]	chars_len	length of chars
[in]	separator	character used in string to separate parts

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options or insufficient buffer space

coap_opt_add_format()

static ssize_t coap_opt_add_format ( coap_pkt_t *  pkt, uint16_t  format  )

inlinestatic

Append a Content-Format option to the pkt buffer.

Postcondition

pkt.payload advanced to first byte after option

pkt.payload_len reduced by option length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	format	COAP_FORMAT_xxx to use

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options or insufficient buffer space

Definition at line 1452 of file nanocoap.h.

coap_opt_add_opaque()

ssize_t coap_opt_add_opaque	(	coap_pkt_t *	pkt,
		uint16_t	optnum,
		const void *	val,
		size_t	val_len
	)

Encode the given buffer as an opaque data option into pkt.

Postcondition

pkt.payload advanced to first byte after option(s)

pkt.payload_len reduced by option(s) length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	optnum	option number to use
[in]	val	pointer to the value to be set
[in]	val_len	length of val

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options

coap_opt_add_proxy_uri()

ssize_t coap_opt_add_proxy_uri	(	coap_pkt_t *	pkt,
		const char *	uri
	)

Adds a single Proxy-URI option into pkt.

Note

uri must be a NULL-terminated absolute URI

Parameters

[in,out]	pkt	Packet being built
[in]	uri	absolute proxy URI

Precondition

((pkt != NULL) && (uri != NULL))

Returns

number of bytes written to pkt buffer

<0 on error

-ENOSPC if no available options or pkt full

coap_opt_add_string()

static ssize_t coap_opt_add_string ( coap_pkt_t *  pkt, uint16_t  optnum, const char *  string, char  separator  )

inlinestatic

Encode the given string as option(s) into pkt.

Use separator to split string into multiple options.

Postcondition

pkt.payload advanced to first byte after option(s)

pkt.payload_len reduced by option(s) length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	optnum	option number to use
[in]	string	string to encode as option
[in]	separator	character used in string to separate parts

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options or insufficient buffer space

Definition at line 1570 of file nanocoap.h.

coap_opt_add_uint()

ssize_t coap_opt_add_uint	(	coap_pkt_t *	pkt,
		uint16_t	optnum,
		uint32_t	value
	)

Encode the given uint option into pkt.

Postcondition

pkt.payload advanced to first byte after option

pkt.payload_len reduced by option length

Parameters

[in,out]	pkt	pkt referencing target buffer
[in]	optnum	option number to use
[in]	value	uint to encode

Returns

number of bytes written to buffer

<0 on error

-ENOSPC if no available options or insufficient buffer space

coap_opt_add_uri_path()

static ssize_t coap_opt_add_uri_path ( coap_pkt_t *  pkt, const char *  path  )

inlinestatic

Adds one or multiple Uri-Path options in the form '/path' into pkt.

Note

Use this only for null-terminated strings.

Parameters

[in,out]	pkt	Packet being built
[in]	path	\0-terminated resource (sub)path

Precondition

((pkt != NULL) && (path != NULL))

Returns

number of bytes written to pkt buffer

<0 on error

-ENOSPC if no available options or pkt full

Definition at line 1590 of file nanocoap.h.

coap_opt_add_uri_path_buffer()

static ssize_t coap_opt_add_uri_path_buffer ( coap_pkt_t *  pkt, const char *  path, size_t  path_len  )

inlinestatic

Adds one or multiple Uri-Path options in the form '/path' into pkt.

Note

Use this only for null-terminated strings.

Parameters

[in,out]	pkt	Packet being built
[in]	path	Resource (sub)path
[in]	path_len	Length of path

Precondition

((pkt != NULL) && (path != NULL))

Returns

number of bytes written to pkt buffer

<0 on error

-ENOSPC if no available options or pkt full

Definition at line 1610 of file nanocoap.h.

coap_opt_add_uri_query()

static ssize_t coap_opt_add_uri_query ( coap_pkt_t *  pkt, const char *  key, const char *  val  )

inlinestatic

Adds a single Uri-Query option in the form 'key=value' into pkt.

Note

Use this only for null-terminated string. See coap_opt_add_uri_query2() for non null-terminated string.

Parameters

[in,out]	pkt	Packet being built
[in]	key	Key to add to the query string
[in]	val	Value to assign to key (may be NULL)

Precondition

((pkt != NULL) && (key != NULL))

Returns

number of bytes written to pkt buffer

<0 on error

-ENOSPC if no available options or pkt full

Definition at line 1510 of file nanocoap.h.

coap_opt_add_uri_query2()

ssize_t coap_opt_add_uri_query2	(	coap_pkt_t *	pkt,
		const char *	key,
		size_t	key_len,
		const char *	val,
		size_t	val_len
	)

Adds a single Uri-Query option in the form 'key=value' into pkt.

Parameters

[in,out]	pkt	Packet being built
[in]	key	Key to add to the query string
[in]	key_len	Length of key
[in]	val	Value to assign to key (may be NULL)
[in]	val_len	Length of val. 0 if val is NULL

Precondition

((pkt != NULL) && (key != NULL) && (key_len > 0) && ((val_len == 0) || ((val != NULL) && (val_len > 0))))

Returns

number of bytes written to pkt buffer

<0 on error

-ENOSPC if no available options or pkt full

coap_opt_finish()

ssize_t coap_opt_finish	(	coap_pkt_t *	pkt,
		uint16_t	flags
	)

Finalizes options as required and prepares for payload.

Postcondition

pkt.payload advanced to first available byte after options

pkt.payload_len is maximum bytes available for payload

Parameters

[in,out]	pkt	pkt to update
[in]	flags	see COAP_OPT_FINISH... macros

Returns

total number of bytes written to buffer

-ENOSPC if no buffer space for payload marker

coap_opt_get_next()

ssize_t coap_opt_get_next	(	const coap_pkt_t *	pkt,
		coap_optpos_t *	opt,
		uint8_t **	value,
		bool	init_opt
	)

Iterate over a packet's options.

To start iteration from the first option, set init_opt to true. To start iteration from a specific option, set init_opt to false, set opt->offset to the offset of the desired option from pkt->hdr, and opt->opt_num as required. See below for how opt->opt_num is modified.

With each invocation, this function returns the length of the option value and sets value to point to the start of the value. The value for opt->opt_num is increased by the delta in the option number value over the preceding option in the packet. So, opt->opt_num is accurate if iteration started with the first option. Otherwise, it is useful for identification of repeated options. Finally, opt->offset is set to the offset for any following option, to prepare for the next iteration.

The end of the options is indicated by a -ENOENT return value. In this case value and opt are unchanged from their input values.

Parameters

[in]	pkt	packet to read from
[in,out]	opt	option attributes; read on input if init_opt is false
[out]	value	start of the option value
[in]	init_opt	true to retrieve first option; false to retrieve option at opt->offset

Returns

length of option value

-ENOENT if option not found

coap_opt_get_opaque()

ssize_t coap_opt_get_opaque	(	coap_pkt_t *	pkt,
		unsigned	opt_num,
		uint8_t **	value
	)

Retrieve the value for an option as an opaque array of bytes.

Retrieves the location and length of the option value of any type. Useful for an opaque option, which essentially is an array of bytes. If more than one option for a given option number, retrieves the first option. To retrieve subsequent options, see coap_opt_get_next().

Parameters

[in]	pkt	packet to read from
[in]	opt_num	option number to retrieve
[out]	value	start of the option value

Returns

length of option; 0 if the option exists but is empty

-ENOENT if option not found

-EINVAL if option cannot be parsed

coap_opt_get_string()

ssize_t coap_opt_get_string	(	coap_pkt_t *	pkt,
		uint16_t	optnum,
		uint8_t *	target,
		size_t	max_len,
		char	separator
	)

Read a full option as null terminated string into the target buffer.

This function is for reading and concatenating string based, multi-part CoAP options like COAP_OPT_URI_PATH or COAP_OPT_LOCATION_PATH. It will write all parts of the given option into the target buffer, separating the parts using the given separator. The resulting string is \0 terminated.

Parameters

[in]	pkt	packet to read from
[in]	optnum	absolute option number
[out]	target	target buffer
[in]	max_len	size of target
[in]	separator	character used for separating the option parts

Returns

-ENOSPC if the complete option does not fit into target

nr of bytes written to target (including '\0')

coap_opt_get_uint()

int coap_opt_get_uint	(	coap_pkt_t *	pkt,
		uint16_t	optnum,
		uint32_t *	value
	)

Get a uint32 option value.

Parameters

[in]	pkt	packet to read from
[in]	optnum	absolute option number
[out]	value	the parsed option value

Returns

0 if the option was found and the value was parsed correctly

-ENOENT if the option was not found in pkt

-ENOSPC if option length is greater than 4 octets

-EBADMSG if option value is invalid

coap_opt_put_block()

size_t coap_opt_put_block	(	uint8_t *	buf,
		uint16_t	lastonum,
		coap_block_slicer_t *	slicer,
		bool	more,
		uint16_t	option
	)

Insert block option into buffer.

When calling this function to initialize a packet with a block option, the more flag must be set to prevent the creation of an option with a length too small to contain the size bit.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option, must be < option
[in]	slicer	coap blockwise slicer helper struct
[in]	more	more flag (1 or 0)
[in]	option	option number (block1 or block2)

Returns

amount of bytes written to buf

coap_opt_put_block1()

static size_t coap_opt_put_block1 ( uint8_t *  buf, uint16_t  lastonum, coap_block_slicer_t *  slicer, bool  more  )

inlinestatic

Insert block1 option into buffer.

When calling this function to initialize a packet with a block1 option, the more flag must be set to prevent the creation of an option with a length too small to contain the size bit.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), must be < 27
[in]	slicer	coap blockwise slicer helper struct
[in]	more	more flag (1 or 0)

Returns

amount of bytes written to buf

Definition at line 1694 of file nanocoap.h.

coap_opt_put_block1_control()

static size_t coap_opt_put_block1_control ( uint8_t *  buf, uint16_t  lastonum, coap_block1_t *  block  )

inlinestatic

Insert block1 option into buffer in control usage.

Parameters

[in]	buf	buffer to write to
[in]	lastonum	last option number (must be < 27)
[in]	block	block option attribute struct

Returns

amount of bytes written to buf

Definition at line 1744 of file nanocoap.h.

coap_opt_put_block2()

static size_t coap_opt_put_block2 ( uint8_t *  buf, uint16_t  lastonum, coap_block_slicer_t *  slicer, bool  more  )

inlinestatic

Insert block2 option into buffer.

When calling this function to initialize a packet with a block2 option, the more flag must be set to prevent the creation of an option with a length too small to contain the size bit.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), must be < 23
[in]	slicer	coap blockwise slicer helper struct
[in]	more	more flag (1 or 0)

Returns

amount of bytes written to buf

Definition at line 1715 of file nanocoap.h.

coap_opt_put_block2_control()

static size_t coap_opt_put_block2_control ( uint8_t *  buf, uint16_t  lastonum, coap_block1_t *  block  )

inlinestatic

Insert block2 option into buffer in control usage.

Forces value of block 'more' attribute to zero, per spec.

Parameters

[in]	buf	buffer to write to
[in]	lastonum	last option number (must be < 27)
[in]	block	block option attribute struct

Returns

amount of bytes written to buf

Definition at line 1762 of file nanocoap.h.

coap_opt_put_location_path()

static size_t coap_opt_put_location_path ( uint8_t *  buf, uint16_t  lastonum, const char *  location  )

inlinestatic

Convenience function for inserting LOCATION_PATH option into buffer.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), or 0 if first option
[in]	location	ptr to string holding the location

Returns

amount of bytes written to buf

Definition at line 1815 of file nanocoap.h.

coap_opt_put_location_query()

static size_t coap_opt_put_location_query ( uint8_t *  buf, uint16_t  lastonum, const char *  location  )

inlinestatic

Convenience function for inserting LOCATION_QUERY option into buffer.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), or 0 if first option
[in]	location	ptr to string holding the location

Returns

amount of bytes written to buf

Definition at line 1833 of file nanocoap.h.

coap_opt_put_proxy_uri()

static size_t coap_opt_put_proxy_uri ( uint8_t *  buf, uint16_t  lastonum, const char *  uri  )

inlinestatic

Convenience function for inserting PROXY_URI option into buffer.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), or 0 if first option
[in]	uri	ptr to source URI

Returns

amount of bytes written to buf

Definition at line 1903 of file nanocoap.h.

coap_opt_put_string()

static size_t coap_opt_put_string ( uint8_t *  buf, uint16_t  lastonum, uint16_t  optnum, const char *  string, char  separator  )

inlinestatic

Encode the given string as multi-part option into buffer.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), or 0 if first option
[in]	optnum	option number to use
[in]	string	string to encode as option
[in]	separator	character used in string to separate parts

Returns

number of bytes written to buf

Definition at line 1797 of file nanocoap.h.

coap_opt_put_string_with_len()

size_t coap_opt_put_string_with_len	(	uint8_t *	buf,
		uint16_t	lastonum,
		uint16_t	optnum,
		const char *	string,
		size_t	len,
		char	separator
	)

Encode the given string as multi-part option into buffer.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), or 0 if first option
[in]	optnum	option number to use
[in]	string	string to encode as option
[in]	len	length of the string
[in]	separator	character used in string to separate parts

Returns

number of bytes written to buf

coap_opt_put_uint()

size_t coap_opt_put_uint	(	uint8_t *	buf,
		uint16_t	lastonum,
		uint16_t	onum,
		uint32_t	value
	)

Encode the given uint option into buffer.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), or 0 for first option
[in]	onum	number of option
[in]	value	value to encode

Returns

amount of bytes written to buf

coap_opt_put_uri_path()

static size_t coap_opt_put_uri_path ( uint8_t *  buf, uint16_t  lastonum, const char *  uri  )

inlinestatic

Convenience function for inserting URI_PATH option into buffer.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), or 0 if first option
[in]	uri	ptr to source URI

Returns

amount of bytes written to buf

Definition at line 1851 of file nanocoap.h.

coap_opt_put_uri_pathquery()

size_t coap_opt_put_uri_pathquery	(	uint8_t *	buf,
		uint16_t *	lastonum,
		const char *	uri
	)

Convenience function for inserting URI_PATH and URI_QUERY into buffer This function will automatically split path and query parameters.

Parameters

[out]	buf	buffer to write to
[in,out]	lastonum	number of previous option (for delta calculation), or 0 if first option May be NULL, then previous option is assumed to be 0.
[in]	uri	ptr into a source URI, to the first character after the authority component

Returns

amount of bytes written to buf

This function may produce two different options (Uri-Path and Uri-Query). Users that need to insert Content-Format, Max-Age or the currently unassigned option 13 need to split their URI themselves and call the respective helper functions.

coap_opt_put_uri_query()

static size_t coap_opt_put_uri_query ( uint8_t *  buf, uint16_t  lastonum, const char *  uri  )

inlinestatic

Convenience function for inserting URI_QUERY option into buffer.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), or 0 if first option
[in]	uri	ptr to source URI

Returns

amount of bytes written to buf

Definition at line 1867 of file nanocoap.h.

coap_opt_remove()

ssize_t coap_opt_remove	(	coap_pkt_t *	pkt,
		uint16_t	optnum
	)

Removes an option previously added with function in the coap_opt_add_...() group.

Parameters

[in]	pkt	Packet to remove option from.
[in]	optnum	Option number of the option to remove. If the option appears more than once, the first occurrence will be removed

Precondition

pkt != NULL

The packet was finished using coap_opt_finish() and any payload is in its final configuration.

Returns

The new size of the packet with option of number optnum removed. In turn this means if there is no such option in the packet, the original size of the packet will be removed.

-EINVAL if there was a parsing error for the existing options

coap_parse()

int coap_parse	(	coap_pkt_t *	pkt,
		uint8_t *	buf,
		size_t	len
	)

Parse a CoAP PDU.

This function parses a raw CoAP PDU from buf with size len and fills the structure pointed to by pkt. pkt must point to a preallocated coap_pkt_t structure.

Parameters

[out]	pkt	structure to parse into
[in]	buf	pointer to raw packet data
[in]	len	length of packet at buf

Returns

0 on success

<0 on error

coap_payload_advance_bytes()

static void coap_payload_advance_bytes ( coap_pkt_t *  pkt, size_t  len  )

inlinestatic

Advance the payload pointer.

Precondition

You added len bytes of data to pkt->payload.

You can add payload to a CoAP request by writing data directly to pkt->payload. This convenience function takes care of advancing the payload pointer afterwards.

Parameters

[out]	pkt	pkt to which payload was added
[in]	len	length of payload

Definition at line 2196 of file nanocoap.h.

coap_payload_put_bytes()

ssize_t coap_payload_put_bytes	(	coap_pkt_t *	pkt,
		const void *	data,
		size_t	len
	)

Add payload data to the CoAP request.

Precondition

coap_opt_finish must have been called before with the COAP_OPT_FINISH_PAYLOAD option.

The function copies data into the payload buffer of pkt and advances the payload pointer.

This is just a convenience function, you can also directly write to pkt->payload if you have a function that outputs payload to a buffer. In this case you should instead call coap_payload_advance_bytes.

Parameters

[out]	pkt	pkt to add payload to
[in]	data	payload data
[in]	len	length of payload

Returns

number of payload bytes added on success

< 0 on error

coap_payload_put_char()

ssize_t coap_payload_put_char	(	coap_pkt_t *	pkt,
		char	c
	)

Add a single character to the payload data of the CoAP request.

This function is used to add single characters to a CoAP payload data. It checks whether the character can be added to the buffer and ignores if the payload area is already exhausted.

Parameters

[out]	pkt	pkt to add payload to
[in]	c	character to write

Returns

number of payload bytes added on success (always one)

< 0 on error

coap_pkt_init()

void coap_pkt_init	(	coap_pkt_t *	pkt,
		uint8_t *	buf,
		size_t	len,
		size_t	header_len
	)

Initialize a packet struct, to build a message buffer.

Precondition

buf CoAP header already initialized

Postcondition

pkt.flags all zeroed

pkt.payload points to first byte after header

pkt.payload_len set to maximum space available for options + payload

Parameters

[out]	pkt	pkt to initialize
[in]	buf	buffer to write for pkt, with CoAP header already initialized
[in]	len	length of buf
[in]	header_len	length of header in buf, including token

coap_pkt_set_code()

static void coap_pkt_set_code ( coap_pkt_t *  pkt, uint8_t  code  )

inlinestatic

Write the given raw message code to given CoAP pkt.

Parameters

[out]	pkt	CoAP packet to write to
[in]	code	raw message code

Definition at line 698 of file nanocoap.h.

coap_put_block1_ok()

size_t coap_put_block1_ok	(	uint8_t *	pkt_pos,
		coap_block1_t *	block1,
		uint16_t	lastonum
	)

Insert block1 option into buffer (from coap_block1_t)

This function is wrapper around coap_put_option_block1(), taking its arguments from a coap_block1_t struct.

It will write option Nr. 27 (COAP_OPT_BLOCK1).

It is safe to be called when block1 was generated for a non-blockwise request.

Parameters

[in]	pkt_pos	buffer to write to
[in]	block1	ptr to block1 struct (created by coap_get_block1())
[in]	lastonum	last option number (must be < 27)

Returns

amount of bytes written to pkt_pos

coap_put_option()

size_t coap_put_option	(	uint8_t *	buf,
		uint16_t	lastonum,
		uint16_t	onum,
		const void *	odata,
		size_t	olen
	)

Insert a CoAP option into buffer.

This function writes a CoAP option with nr. onum to buf. It handles calculating the option delta (from lastonum), encoding the length from olen and copying the option data from odata.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), or 0 for first option
[in]	onum	number of option
[in]	odata	ptr to raw option data (or NULL)
[in]	olen	length of odata (if any)

Returns

amount of bytes written to buf

coap_put_option_block1()

static size_t coap_put_option_block1 ( uint8_t *  buf, uint16_t  lastonum, unsigned  blknum, unsigned  szx, int  more  )

inlinestatic

Insert block1 option into buffer.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), must be < 27
[in]	blknum	block number
[in]	szx	SXZ value
[in]	more	more flag (1 or 0)

Returns

amount of bytes written to buf

Definition at line 1958 of file nanocoap.h.

coap_put_option_ct()

static size_t coap_put_option_ct ( uint8_t *  buf, uint16_t  lastonum, uint16_t  content_type  )

inlinestatic

Insert content type option into buffer.

Parameters

[out]	buf	buffer to write to
[in]	lastonum	number of previous option (for delta calculation), or 0 if first option
[in]	content_type	content type to set

Returns

amount of bytes written to buf

Definition at line 1975 of file nanocoap.h.

coap_reply_simple()

ssize_t coap_reply_simple	(	coap_pkt_t *	pkt,
		unsigned	code,
		uint8_t *	buf,
		size_t	len,
		unsigned	ct,
		const void *	payload,
		size_t	payload_len
	)

Create CoAP reply (convenience function)

This is a simple wrapper that allows for building CoAP replies for simple use-cases.

The reply will be written to buf. If payload and payload_len are non-zero, the payload will be copied into the resulting reply packet.

Parameters

[in]	pkt	packet to reply to
[in]	code	reply code (e.g., COAP_CODE_204)
[out]	buf	buffer to write reply to
[in]	len	size of buf
[in]	ct	content type of payload
[in]	payload	ptr to payload
[in]	payload_len	length of payload

Returns

size of reply packet on success

<0 on error

-ENOSPC if buf too small

coap_request_ctx_get_context()

void * coap_request_ctx_get_context

(

const coap_request_ctx_t *

ctx

)

Get resource context associated with a CoAP request.

Parameters

[in]

ctx

The request context

Returns

Resource context of the request

coap_request_ctx_get_local_udp()

const sock_udp_ep_t * coap_request_ctx_get_local_udp

(

const coap_request_ctx_t *

ctx

)

Get the local endpoint on which the request has been received.

Parameters

[in]

ctx

The request context

Returns

Local endpoint to which the request has been received

NULL The request was not received via UDP

coap_request_ctx_get_path()

const char * coap_request_ctx_get_path

(

const coap_request_ctx_t *

ctx

)

Get resource path associated with a CoAP request.

Parameters

[in]

ctx

The request context

Returns

Resource path of the request

coap_request_ctx_get_remote_udp()

const sock_udp_ep_t * coap_request_ctx_get_remote_udp

(

const coap_request_ctx_t *

ctx

)

Get the remote endpoint from which the request was received.

Parameters

[in]

ctx

The request context

Returns

Remote endpoint from which the request originated

NULL The request was not received via UDP

coap_request_ctx_get_tl_type()

uint32_t coap_request_ctx_get_tl_type

(

const coap_request_ctx_t *

ctx

)

Get transport the packet was received over.

See also

gcoap_socket_type_t for values.

Parameters

[in]

ctx

The request context

Returns

Transport Layer type of the request

coap_request_ctx_init()

void coap_request_ctx_init	(	coap_request_ctx_t *	ctx,
		sock_udp_ep_t *	remote
	)

Initialize CoAP request context.

Parameters

[in]	ctx	Pointer to the request context to initialize
[in]	remote	Remote endpoint that made the request

coap_size2szx()

static unsigned coap_size2szx ( unsigned  len )

inlinestatic

Helper to encode byte size into next equal or smaller SZX value.

Parameters

[in]

len

Size in bytes

Returns

closest SZX value that fits into a buffer of len

Definition at line 1281 of file nanocoap.h.

coap_subtree_handler()

ssize_t coap_subtree_handler	(	coap_pkt_t *	pkt,
		uint8_t *	resp_buf,
		size_t	resp_buf_len,
		coap_request_ctx_t *	context
	)

Generic coap subtree handler.

This function can be used as a generic handler for resources with the COAP_MATCH_SUBTREE where a new coap_resource_t is to be parsed.

Note

The context must be of type coap_resource_subtree_t.

Parameters

[in]	pkt	pointer to (parsed) CoAP packet
[out]	resp_buf	buffer for response
[in]	resp_buf_len	size of response buffer
[in]	context	pointer to request context, must contain context to coap_resource_subtree_t instance

Returns

size of the reply packet on success

<0 on error

coap_tree_handler()

ssize_t coap_tree_handler	(	coap_pkt_t *	pkt,
		uint8_t *	resp_buf,
		unsigned	resp_buf_len,
		coap_request_ctx_t *	ctx,
		const coap_resource_t *	resources,
		size_t	resources_numof
	)

Pass a coap request to a matching handler.

This function will try to find a matching handler in resources and call the handler.

Parameters

[in]	pkt	pointer to (parsed) CoAP packet
[out]	resp_buf	buffer for response
[in]	resp_buf_len	size of response buffer
[in]	ctx	CoAP request context information
[in]	resources	Array of coap endpoint resources
[in]	resources_numof	length of the coap endpoint resources

Returns

size of the reply packet on success

<0 on error