/* * pdu.h -- CoAP message structure * * Copyright (C) 2010-2014 Olaf Bergmann * * SPDX-License-Identifier: BSD-2-Clause * * This file is part of the CoAP library libcoap. Please see README for terms * of use. */ /** * @file pdu.h * @brief Pre-defined constants that reflect defaults for CoAP */ #ifndef COAP_PDU_H_ #define COAP_PDU_H_ #include "uri.h" #include "option.h" #ifdef WITH_LWIP #include #endif #include /** * @defgroup pdu PDU * API functions for PDUs * @{ */ #define COAP_DEFAULT_PORT 5683 /* CoAP default UDP/TCP port */ #define COAPS_DEFAULT_PORT 5684 /* CoAP default UDP/TCP port for secure transmission */ #define COAP_DEFAULT_MAX_AGE 60 /* default maximum object lifetime in seconds */ #ifndef COAP_DEFAULT_MTU #define COAP_DEFAULT_MTU 1152 #endif /* COAP_DEFAULT_MTU */ #ifndef COAP_DEFAULT_HOP_LIMIT #define COAP_DEFAULT_HOP_LIMIT 16 #endif /* COAP_DEFAULT_HOP_LIMIT */ #define COAP_DEFAULT_SCHEME "coap" /* the default scheme for CoAP URIs */ /** well-known resources URI */ #define COAP_DEFAULT_URI_WELLKNOWN ".well-known/core" /* CoAP message types */ /** * CoAP PDU message type definitions */ typedef enum coap_pdu_type_t { COAP_MESSAGE_CON, /* 0 confirmable message (requires ACK/RST) */ COAP_MESSAGE_NON, /* 1 non-confirmable message (one-shot message) */ COAP_MESSAGE_ACK, /* 2 used to acknowledge confirmable messages */ COAP_MESSAGE_RST /* 3 indicates error in received messages */ } coap_pdu_type_t; /** * CoAP PDU Request methods */ typedef enum coap_request_t { COAP_REQUEST_GET = 1, COAP_REQUEST_POST, /* 2 */ COAP_REQUEST_PUT, /* 3 */ COAP_REQUEST_DELETE, /* 4 */ COAP_REQUEST_FETCH, /* 5 RFC 8132 */ COAP_REQUEST_PATCH, /* 6 RFC 8132 */ COAP_REQUEST_IPATCH, /* 7 RFC 8132 */ } coap_request_t; /* * CoAP option numbers (be sure to update coap_option_check_critical() and * coap_add_option() when adding options */ /* * The C, U, and N flags indicate the properties * Critical, Unsafe, and NoCacheKey, respectively. * If U is set, then N has no meaning as per * https://tools.ietf.org/html/rfc7252#section-5.10 * and is set to a -. * * Separately, R is for the options that can be repeated * * The least significant byte of the option is set as followed * as per https://tools.ietf.org/html/rfc7252#section-5.4.6 * * 0 1 2 3 4 5 6 7 * --+---+---+---+---+---+---+---+ * | NoCacheKey| U | C | * --+---+---+---+---+---+---+---+ * * https://tools.ietf.org/html/rfc8613#section-4 goes on to define E, I and U * properties Encrypted and Integrity Protected, Integrity Protected Only, and * Unprotected respectively. Integrity Protected Only is not currently used. * * An Option is tagged with CUNREIU with any of the letters replaced with _ if * not set, or - for N if U is set (see above) for aiding understanding of the * Option. */ #define COAP_OPTION_IF_MATCH 1 /* C__RE__, opaque, 0-8 B, RFC7252 */ #define COAP_OPTION_URI_HOST 3 /* CU-___U, String, 1-255 B, RFC7252 */ #define COAP_OPTION_ETAG 4 /* ___RE__, opaque, 1-8 B, RFC7252 */ #define COAP_OPTION_IF_NONE_MATCH 5 /* C___E__, empty, 0 B, RFC7252 */ #define COAP_OPTION_OBSERVE 6 /* _U-_E_U, empty/uint,0/0-3 B, RFC7641 */ #define COAP_OPTION_URI_PORT 7 /* CU-___U, uint, 0-2 B, RFC7252 */ #define COAP_OPTION_LOCATION_PATH 8 /* ___RE__, String, 0-255 B, RFC7252 */ #define COAP_OPTION_OSCORE 9 /* C_____U, *, 0-255 B, RFC8613 */ #define COAP_OPTION_URI_PATH 11 /* CU-RE__, String, 0-255 B, RFC7252 */ #define COAP_OPTION_CONTENT_FORMAT 12 /* ____E__, uint, 0-2 B, RFC7252 */ #define COAP_OPTION_CONTENT_TYPE COAP_OPTION_CONTENT_FORMAT /* COAP_OPTION_MAXAGE default 60 seconds if not set */ #define COAP_OPTION_MAXAGE 14 /* _U-_E_U, uint, 0-4 B, RFC7252 */ #define COAP_OPTION_URI_QUERY 15 /* CU-RE__, String, 1-255 B, RFC7252 */ #define COAP_OPTION_HOP_LIMIT 16 /* ______U, uint, 1 B, RFC8768 */ #define COAP_OPTION_ACCEPT 17 /* C___E__, uint, 0-2 B, RFC7252 */ #define COAP_OPTION_LOCATION_QUERY 20 /* ___RE__, String, 0-255 B, RFC7252 */ #define COAP_OPTION_BLOCK2 23 /* CU-_E_U, uint, 0-3 B, RFC7959 */ #define COAP_OPTION_BLOCK1 27 /* CU-_E_U, uint, 0-3 B, RFC7959 */ #define COAP_OPTION_SIZE2 28 /* __N_E_U, uint, 0-4 B, RFC7959 */ #define COAP_OPTION_PROXY_URI 35 /* CU-___U, String, 1-1034 B, RFC7252 */ #define COAP_OPTION_PROXY_SCHEME 39 /* CU-___U, String, 1-255 B, RFC7252 */ #define COAP_OPTION_SIZE1 60 /* __N_E_U, uint, 0-4 B, RFC7252 */ #define COAP_OPTION_NORESPONSE 258 /* _U-_E_U, uint, 0-1 B, RFC7967 */ #define COAP_MAX_OPT 65535 /**< the highest option number we know */ /* CoAP result codes (HTTP-Code / 100 * 40 + HTTP-Code % 100) */ /* As of draft-ietf-core-coap-04, response codes are encoded to base * 32, i.e. the three upper bits determine the response class while * the remaining five fine-grained information specific to that class. */ #define COAP_RESPONSE_CODE(N) (((N)/100 << 5) | (N)%100) /* Determines the class of response code C */ #define COAP_RESPONSE_CLASS(C) (((C) >> 5) & 0xFF) #ifndef SHORT_ERROR_RESPONSE /** * Returns a human-readable response phrase for the specified CoAP response @p * code. This function returns @c NULL if not found. * * @param code The response code for which the literal phrase should be * retrieved. * * @return A zero-terminated string describing the error, or @c NULL if not * found. */ const char *coap_response_phrase(unsigned char code); #define COAP_ERROR_PHRASE_LENGTH 32 /**< maximum length of error phrase */ #else #define coap_response_phrase(x) ((char *)NULL) #define COAP_ERROR_PHRASE_LENGTH 0 /**< maximum length of error phrase */ #endif /* SHORT_ERROR_RESPONSE */ #define COAP_SIGNALING_CODE(N) (((N)/100 << 5) | (N)%100) typedef enum coap_pdu_signaling_proto_t { COAP_SIGNALING_CSM = COAP_SIGNALING_CODE(701), COAP_SIGNALING_PING = COAP_SIGNALING_CODE(702), COAP_SIGNALING_PONG = COAP_SIGNALING_CODE(703), COAP_SIGNALING_RELEASE = COAP_SIGNALING_CODE(704), COAP_SIGNALING_ABORT = COAP_SIGNALING_CODE(705), } coap_pdu_signaling_proto_t; /* Applies to COAP_SIGNALING_CSM */ #define COAP_SIGNALING_OPTION_MAX_MESSAGE_SIZE 2 #define COAP_SIGNALING_OPTION_BLOCK_WISE_TRANSFER 4 /* Applies to COAP_SIGNALING_PING / COAP_SIGNALING_PONG */ #define COAP_SIGNALING_OPTION_CUSTODY 2 /* Applies to COAP_SIGNALING_RELEASE */ #define COAP_SIGNALING_OPTION_ALTERNATIVE_ADDRESS 2 #define COAP_SIGNALING_OPTION_HOLD_OFF 4 /* Applies to COAP_SIGNALING_ABORT */ #define COAP_SIGNALING_OPTION_BAD_CSM_OPTION 2 /* CoAP media type encoding */ #define COAP_MEDIATYPE_TEXT_PLAIN 0 /* text/plain (UTF-8) */ #define COAP_MEDIATYPE_APPLICATION_LINK_FORMAT 40 /* application/link-format */ #define COAP_MEDIATYPE_APPLICATION_XML 41 /* application/xml */ #define COAP_MEDIATYPE_APPLICATION_OCTET_STREAM 42 /* application/octet-stream */ #define COAP_MEDIATYPE_APPLICATION_RDF_XML 43 /* application/rdf+xml */ #define COAP_MEDIATYPE_APPLICATION_EXI 47 /* application/exi */ #define COAP_MEDIATYPE_APPLICATION_JSON 50 /* application/json */ #define COAP_MEDIATYPE_APPLICATION_CBOR 60 /* application/cbor */ #define COAP_MEDIATYPE_APPLICATION_CWT 61 /* application/cwt, RFC 8392 */ /* Content formats from RFC 8152 */ #define COAP_MEDIATYPE_APPLICATION_COSE_SIGN 98 /* application/cose; cose-type="cose-sign" */ #define COAP_MEDIATYPE_APPLICATION_COSE_SIGN1 18 /* application/cose; cose-type="cose-sign1" */ #define COAP_MEDIATYPE_APPLICATION_COSE_ENCRYPT 96 /* application/cose; cose-type="cose-encrypt" */ #define COAP_MEDIATYPE_APPLICATION_COSE_ENCRYPT0 16 /* application/cose; cose-type="cose-encrypt0" */ #define COAP_MEDIATYPE_APPLICATION_COSE_MAC 97 /* application/cose; cose-type="cose-mac" */ #define COAP_MEDIATYPE_APPLICATION_COSE_MAC0 17 /* application/cose; cose-type="cose-mac0" */ #define COAP_MEDIATYPE_APPLICATION_COSE_KEY 101 /* application/cose-key */ #define COAP_MEDIATYPE_APPLICATION_COSE_KEY_SET 102 /* application/cose-key-set */ /* Content formats from RFC 8428 */ #define COAP_MEDIATYPE_APPLICATION_SENML_JSON 110 /* application/senml+json */ #define COAP_MEDIATYPE_APPLICATION_SENSML_JSON 111 /* application/sensml+json */ #define COAP_MEDIATYPE_APPLICATION_SENML_CBOR 112 /* application/senml+cbor */ #define COAP_MEDIATYPE_APPLICATION_SENSML_CBOR 113 /* application/sensml+cbor */ #define COAP_MEDIATYPE_APPLICATION_SENML_EXI 114 /* application/senml-exi */ #define COAP_MEDIATYPE_APPLICATION_SENSML_EXI 115 /* application/sensml-exi */ #define COAP_MEDIATYPE_APPLICATION_SENML_XML 310 /* application/senml+xml */ #define COAP_MEDIATYPE_APPLICATION_SENSML_XML 311 /* application/sensml+xml */ /* Content formats from RFC 8782 */ #define COAP_MEDIATYPE_APPLICATION_DOTS_CBOR 271 /* application/dots+cbor */ /* Note that identifiers for registered media types are in the range 0-65535. We * use an unallocated type here and hope for the best. */ #define COAP_MEDIATYPE_ANY 0xff /* any media type */ /** * coap_mid_t is used to store the CoAP Message ID of a CoAP PDU. * Valid message ids are 0 to 2^16. Negative values are error codes. */ typedef int coap_mid_t; /** Indicates an invalid message id. */ #define COAP_INVALID_MID -1 /** * Indicates an invalid message id. * @deprecated Use COAP_INVALID_MID instead. */ #define COAP_INVALID_TID COAP_INVALID_MID /** * @deprecated Use coap_optlist_t instead. * * Structures for more convenient handling of options. (To be used with ordered * coap_list_t.) The option's data will be added to the end of the coap_option * structure (see macro COAP_OPTION_DATA). */ COAP_DEPRECATED typedef struct { uint16_t key; /* the option key (no delta coding) */ unsigned int length; } coap_option; #define COAP_OPTION_KEY(option) (option).key #define COAP_OPTION_LENGTH(option) (option).length #define COAP_OPTION_DATA(option) ((unsigned char *)&(option) + sizeof(coap_option)) #ifdef WITH_LWIP /** * Creates a CoAP PDU from an lwIP @p pbuf, whose reference is passed on to this * function. * * The pbuf is checked for being contiguous, and for having only one reference. * The reference is stored in the PDU and will be freed when the PDU is freed. * * (For now, these are fatal errors; in future, a new pbuf might be allocated, * the data copied and the passed pbuf freed). * * This behaves like coap_pdu_init(0, 0, 0, pbuf->tot_len), and afterwards * copying the contents of the pbuf to the pdu. * * @return A pointer to the new PDU object or @c NULL on error. */ coap_pdu_t * coap_pdu_from_pbuf(struct pbuf *pbuf); #endif /** * CoAP protocol types */ typedef enum coap_proto_t { COAP_PROTO_NONE = 0, COAP_PROTO_UDP, COAP_PROTO_DTLS, COAP_PROTO_TCP, COAP_PROTO_TLS, } coap_proto_t; /** * Set of codes available for a PDU. */ typedef enum coap_pdu_code_t { COAP_EMPTY_CODE = 0, COAP_REQUEST_CODE_GET = COAP_REQUEST_GET, COAP_REQUEST_CODE_POST = COAP_REQUEST_POST, COAP_REQUEST_CODE_PUT = COAP_REQUEST_PUT, COAP_REQUEST_CODE_DELETE = COAP_REQUEST_DELETE, COAP_REQUEST_CODE_FETCH = COAP_REQUEST_FETCH, COAP_REQUEST_CODE_PATCH = COAP_REQUEST_PATCH, COAP_REQUEST_CODE_IPATCH = COAP_REQUEST_IPATCH, COAP_RESPONSE_CODE_OK = COAP_RESPONSE_CODE(200), COAP_RESPONSE_CODE_CREATED = COAP_RESPONSE_CODE(201), COAP_RESPONSE_CODE_DELETED = COAP_RESPONSE_CODE(202), COAP_RESPONSE_CODE_VALID = COAP_RESPONSE_CODE(203), COAP_RESPONSE_CODE_CHANGED = COAP_RESPONSE_CODE(204), COAP_RESPONSE_CODE_CONTENT = COAP_RESPONSE_CODE(205), COAP_RESPONSE_CODE_CONTINUE = COAP_RESPONSE_CODE(231), COAP_RESPONSE_CODE_BAD_REQUEST = COAP_RESPONSE_CODE(400), COAP_RESPONSE_CODE_UNAUTHORIZED = COAP_RESPONSE_CODE(401), COAP_RESPONSE_CODE_BAD_OPTION = COAP_RESPONSE_CODE(402), COAP_RESPONSE_CODE_FORBIDDEN = COAP_RESPONSE_CODE(403), COAP_RESPONSE_CODE_NOT_FOUND = COAP_RESPONSE_CODE(404), COAP_RESPONSE_CODE_NOT_ALLOWED = COAP_RESPONSE_CODE(405), COAP_RESPONSE_CODE_NOT_ACCEPTABLE = COAP_RESPONSE_CODE(406), COAP_RESPONSE_CODE_INCOMPLETE = COAP_RESPONSE_CODE(408), COAP_RESPONSE_CODE_CONFLICT = COAP_RESPONSE_CODE(409), COAP_RESPONSE_CODE_PRECONDITION_FAILED = COAP_RESPONSE_CODE(412), COAP_RESPONSE_CODE_REQUEST_TOO_LARGE = COAP_RESPONSE_CODE(413), COAP_RESPONSE_CODE_UNSUPPORTED_CONTENT_FORMAT = COAP_RESPONSE_CODE(415), COAP_RESPONSE_CODE_UNPROCESSABLE = COAP_RESPONSE_CODE(422), COAP_RESPONSE_CODE_TOO_MANY_REQUESTS = COAP_RESPONSE_CODE(429), COAP_RESPONSE_CODE_INTERNAL_ERROR = COAP_RESPONSE_CODE(500), COAP_RESPONSE_CODE_NOT_IMPLEMENTED = COAP_RESPONSE_CODE(501), COAP_RESPONSE_CODE_BAD_GATEWAY = COAP_RESPONSE_CODE(502), COAP_RESPONSE_CODE_SERVICE_UNAVAILABLE = COAP_RESPONSE_CODE(503), COAP_RESPONSE_CODE_GATEWAY_TIMEOUT = COAP_RESPONSE_CODE(504), COAP_RESPONSE_CODE_PROXYING_NOT_SUPPORTED = COAP_RESPONSE_CODE(505), COAP_RESPONSE_CODE_HOP_LIMIT_REACHED = COAP_RESPONSE_CODE(508), COAP_SIGNALING_CODE_CSM = COAP_SIGNALING_CSM, COAP_SIGNALING_CODE_PING = COAP_SIGNALING_PING, COAP_SIGNALING_CODE_PONG = COAP_SIGNALING_PONG, COAP_SIGNALING_CODE_RELEASE = COAP_SIGNALING_RELEASE, COAP_SIGNALING_CODE_ABORT = COAP_SIGNALING_ABORT } coap_pdu_code_t; /** * Creates a new CoAP PDU with at least enough storage space for the given * @p size maximum message size. The function returns a pointer to the * node coap_pdu_t object on success, or @c NULL on error. The storage allocated * for the result must be released with coap_delete_pdu() if coap_send() * is not called. * * @param type The type of the PDU (one of COAP_MESSAGE_CON, COAP_MESSAGE_NON, * COAP_MESSAGE_ACK, COAP_MESSAGE_RST). * @param code The message code of the PDU. * @param mid The message id to set or 0 if unknown / not applicable. * @param size The maximum allowed number of byte for the message. * @return A pointer to the new PDU object or @c NULL on error. */ coap_pdu_t *coap_pdu_init(coap_pdu_type_t type, coap_pdu_code_t code, coap_mid_t mid, size_t size); /** * Creates a new CoAP PDU. * * @param type The type of the PDU (one of COAP_MESSAGE_CON, COAP_MESSAGE_NON, * COAP_MESSAGE_ACK, COAP_MESSAGE_RST). * @param code The message code of the PDU. * @param session The session that will be using this PDU * * @return The skeletal PDU or @c NULL if failure. */ coap_pdu_t *coap_new_pdu(coap_pdu_type_t type, coap_pdu_code_t code, coap_session_t *session); /** * Dispose of an CoAP PDU and frees associated storage. * Not that in general you should not call this function directly. * When a PDU is sent with coap_send(), coap_delete_pdu() will be called * automatically for you. * * @param pdu The PDU for free off. */ void coap_delete_pdu(coap_pdu_t *pdu); /** * Duplicate an existing PDU. Specific options can be ignored and not copied * across. The PDU data payload is not copied across. * * @param old_pdu The PDU to duplicate * @param session The session that will be using this PDU. * @param token_length The length of the token to use in this duplicated PDU. * @param token The token to use in this duplicated PDU. * @param drop_options A list of options not to copy into the duplicated PDU. * If @c NULL, then all options are copied across. * * @return The duplicated PDU or @c NULL if failure. */ coap_pdu_t * coap_pdu_duplicate(const coap_pdu_t *old_pdu, coap_session_t *session, size_t token_length, const uint8_t *token, coap_opt_filter_t *drop_options); /** * Adds token of length @p len to @p pdu. * Adding the token destroys any following contents of the pdu. Hence options * and data must be added after coap_add_token() has been called. In @p pdu, * length is set to @p len + @c 4, and max_delta is set to @c 0. This function * returns @c 0 on error or a value greater than zero on success. * * @param pdu The PDU where the token is to be added. * @param len The length of the new token. * @param data The token to add. * * @return A value greater than zero on success, or @c 0 on error. */ int coap_add_token(coap_pdu_t *pdu, size_t len, const uint8_t *data); /** * Adds option of given number to pdu that is passed as first * parameter. * coap_add_option() destroys the PDU's data, so coap_add_data() must be called * after all options have been added. As coap_add_token() destroys the options * following the token, the token must be added before coap_add_option() is * called. This function returns the number of bytes written or @c 0 on error. * * Note: Where possible, the option data needs to be stripped of leading zeros * (big endian) to reduce the amount of data needed in the PDU, as well as in * some cases the maximum data size of an opton can be exceeded if not stripped * and hence be illegal. This is done by using coap_encode_var_safe() or * coap_encode_var_safe8(). * * @param pdu The PDU where the option is to be added. * @param number The number of the new option. * @param len The length of the new option. * @param data The data of the new option. * * @return The overall length of the option or @c 0 on failure. */ size_t coap_add_option(coap_pdu_t *pdu, coap_option_num_t number, size_t len, const uint8_t *data); /** * Adds given data to the pdu that is passed as first parameter. Note that the * PDU's data is destroyed by coap_add_option(). coap_add_data() must be called * only once per PDU, otherwise the result is undefined. * * @param pdu The PDU where the data is to be added. * @param len The length of the data. * @param data The data to add. * * @return @c 1 if success, else @c 0 if failure. */ int coap_add_data(coap_pdu_t *pdu, size_t len, const uint8_t *data); /** * Adds given data to the pdu that is passed as first parameter but does not * copy it. Note that the PDU's data is destroyed by coap_add_option(). * coap_add_data() must be have been called once for this PDU, otherwise the * result is undefined. * The actual data must be copied at the returned location. * * @param pdu The PDU where the data is to be added. * @param len The length of the data. * * @return Where to copy the data of len to, or @c NULL is error. */ uint8_t *coap_add_data_after(coap_pdu_t *pdu, size_t len); /** * Retrieves the length and data pointer of specified PDU. Returns 0 on error or * 1 if *len and *data have correct values. Note that these values are destroyed * with the pdu. * * @param pdu The specified PDU. * @param len Returns the length of the current data * @param data Returns the ptr to the current data * * @return @c 1 if len and data are correctly filled in, else * @c 0 if there is no data. */ int coap_get_data(const coap_pdu_t *pdu, size_t *len, const uint8_t **data); /** * Retrieves the data from a PDU, with support for large bodies of data that * spans multiple PDUs. * * Note: The data pointed to on return is destroyed when the PDU is destroyed. * * @param pdu The specified PDU. * @param len Returns the length of the current data * @param data Returns the ptr to the current data * @param offset Returns the offset of the current data from the start of the * body comprising of many blocks (RFC7959) * @param total Returns the total size of the body. * If offset + length < total, then there is more data to follow. * * @return @c 1 if len, data, offset and total are correctly filled in, else * @c 0 if there is no data. */ int coap_get_data_large(const coap_pdu_t *pdu, size_t *len, const uint8_t **data, size_t *offset, size_t *total); /** * Gets the PDU code associated with @p pdu. * * @param pdu The PDU object. * * @return The PDU code. */ coap_pdu_code_t coap_pdu_get_code(const coap_pdu_t *pdu); /** * Sets the PDU code in the @p pdu. * * @param pdu The PDU object. * @param code The code to set in the PDU. */ void coap_pdu_set_code(coap_pdu_t *pdu, coap_pdu_code_t code); /** * Gets the PDU type associated with @p pdu. * * @param pdu The PDU object. * * @return The PDU type. */ coap_pdu_type_t coap_pdu_get_type(const coap_pdu_t *pdu); /** * Sets the PDU type in the @p pdu. * * @param pdu The PDU object. * @param type The type to set for the PDU. */ void coap_pdu_set_type(coap_pdu_t *pdu, coap_pdu_type_t type); /** * Gets the token associated with @p pdu. * * @param pdu The PDU object. * * @return The token information. */ coap_bin_const_t coap_pdu_get_token(const coap_pdu_t *pdu); /** * Gets the message id associated with @p pdu. * * @param pdu The PDU object. * * @return The message id. */ coap_mid_t coap_pdu_get_mid(const coap_pdu_t *pdu); /** * Sets the message id in the @p pdu. * * @param pdu The PDU object. * @param mid The message id value to set in the PDU. * */ void coap_pdu_set_mid(coap_pdu_t *pdu, coap_mid_t mid); /** @} */ #endif /* COAP_PDU_H_ */