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/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
*
* @brief CoAP implementation for Zephyr.
*/
#ifndef __ZOAP_H__
#define __ZOAP_H__
#include <zephyr/types.h>
#include <stddef.h>
#include <stdbool.h>
#include <net/net_ip.h>
#include <misc/slist.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief COAP library
* @defgroup zoap COAP Library
* @{
*/
/**
* @brief Set of CoAP packet options we are aware of.
*
* Users may add options other than these to their packets, provided
* they know how to format them correctly. The only restriction is
* that all options must be added to a packet in numeric order.
*
* Refer to RFC 7252, section 12.2 for more information.
*/
enum zoap_option_num {
ZOAP_OPTION_IF_MATCH = 1,
ZOAP_OPTION_URI_HOST = 3,
ZOAP_OPTION_ETAG = 4,
ZOAP_OPTION_IF_NONE_MATCH = 5,
ZOAP_OPTION_OBSERVE = 6,
ZOAP_OPTION_URI_PORT = 7,
ZOAP_OPTION_LOCATION_PATH = 8,
ZOAP_OPTION_URI_PATH = 11,
ZOAP_OPTION_CONTENT_FORMAT = 12,
ZOAP_OPTION_MAX_AGE = 14,
ZOAP_OPTION_URI_QUERY = 15,
ZOAP_OPTION_ACCEPT = 17,
ZOAP_OPTION_LOCATION_QUERY = 20,
ZOAP_OPTION_BLOCK2 = 23,
ZOAP_OPTION_BLOCK1 = 27,
ZOAP_OPTION_SIZE2 = 28,
ZOAP_OPTION_PROXY_URI = 35,
ZOAP_OPTION_PROXY_SCHEME = 39,
ZOAP_OPTION_SIZE1 = 60,
};
/**
* @brief Available request methods.
*
* To be used with zoap_header_set_code() when creating a request
* or a response.
*/
enum zoap_method {
ZOAP_METHOD_GET = 1,
ZOAP_METHOD_POST = 2,
ZOAP_METHOD_PUT = 3,
ZOAP_METHOD_DELETE = 4,
};
#define ZOAP_REQUEST_MASK 0x07
/**
* @brief CoAP packets may be of one of these types.
*/
enum zoap_msgtype {
/**
* Confirmable message.
*
* The packet is a request or response the destination end-point must
* acknowledge.
*/
ZOAP_TYPE_CON = 0,
/**
* Non-confirmable message.
*
* The packet is a request or response that doesn't
* require acknowledgements.
*/
ZOAP_TYPE_NON_CON = 1,
/**
* Acknowledge.
*
* Response to a confirmable message.
*/
ZOAP_TYPE_ACK = 2,
/**
* Reset.
*
* Rejecting a packet for any reason is done by sending a message
* of this type.
*/
ZOAP_TYPE_RESET = 3
};
#define zoap_make_response_code(clas, det) ((clas << 5) | (det))
/**
* @brief Set of response codes available for a response packet.
*
* To be used with zoap_header_set_code() when creating a response.
*/
enum zoap_response_code {
ZOAP_RESPONSE_CODE_OK = zoap_make_response_code(2, 0),
ZOAP_RESPONSE_CODE_CREATED = zoap_make_response_code(2, 1),
ZOAP_RESPONSE_CODE_DELETED = zoap_make_response_code(2, 2),
ZOAP_RESPONSE_CODE_VALID = zoap_make_response_code(2, 3),
ZOAP_RESPONSE_CODE_CHANGED = zoap_make_response_code(2, 4),
ZOAP_RESPONSE_CODE_CONTENT = zoap_make_response_code(2, 5),
ZOAP_RESPONSE_CODE_CONTINUE = zoap_make_response_code(2, 31),
ZOAP_RESPONSE_CODE_BAD_REQUEST = zoap_make_response_code(4, 0),
ZOAP_RESPONSE_CODE_UNAUTHORIZED = zoap_make_response_code(4, 1),
ZOAP_RESPONSE_CODE_BAD_OPTION = zoap_make_response_code(4, 2),
ZOAP_RESPONSE_CODE_FORBIDDEN = zoap_make_response_code(4, 3),
ZOAP_RESPONSE_CODE_NOT_FOUND = zoap_make_response_code(4, 4),
ZOAP_RESPONSE_CODE_NOT_ALLOWED = zoap_make_response_code(4, 5),
ZOAP_RESPONSE_CODE_NOT_ACCEPTABLE = zoap_make_response_code(4, 6),
ZOAP_RESPONSE_CODE_INCOMPLETE = zoap_make_response_code(4, 8),
ZOAP_RESPONSE_CODE_PRECONDITION_FAILED = zoap_make_response_code(4, 12),
ZOAP_RESPONSE_CODE_REQUEST_TOO_LARGE = zoap_make_response_code(4, 13),
ZOAP_RESPONSE_CODE_UNSUPPORTED_CONTENT_FORMAT = zoap_make_response_code(4, 15),
ZOAP_RESPONSE_CODE_INTERNAL_ERROR = zoap_make_response_code(5, 0),
ZOAP_RESPONSE_CODE_NOT_IMPLEMENTED = zoap_make_response_code(5, 1),
ZOAP_RESPONSE_CODE_BAD_GATEWAY = zoap_make_response_code(5, 2),
ZOAP_RESPONSE_CODE_SERVICE_UNAVAILABLE = zoap_make_response_code(5, 3),
ZOAP_RESPONSE_CODE_GATEWAY_TIMEOUT = zoap_make_response_code(5, 4),
ZOAP_RESPONSE_CODE_PROXYING_NOT_SUPPORTED = zoap_make_response_code(5, 5)
};
#define ZOAP_CODE_EMPTY (0)
struct zoap_observer;
struct zoap_packet;
struct zoap_pending;
struct zoap_reply;
struct zoap_resource;
/**
* @typedef zoap_method_t
* @brief Type of the callback being called when a resource's method is
* invoked by the remote entity.
*/
typedef int (*zoap_method_t)(struct zoap_resource *resource,
struct zoap_packet *request,
const struct sockaddr *from);
/**
* @typedef zoap_notify_t
* @brief Type of the callback being called when a resource's has observers
* to be informed when an update happens.
*/
typedef void (*zoap_notify_t)(struct zoap_resource *resource,
struct zoap_observer *observer);
/**
* @brief Description of CoAP resource.
*
* CoAP servers often want to register resources, so that clients can act on
* them, by fetching their state or requesting updates to them.
*/
struct zoap_resource {
/** Which function to be called for each CoAP method */
zoap_method_t get, post, put, del;
zoap_notify_t notify;
const char * const *path;
void *user_data;
sys_slist_t observers;
int age;
};
/**
* @brief Represents a remote device that is observing a local resource.
*/
struct zoap_observer {
sys_snode_t list;
struct sockaddr addr;
u8_t token[8];
u8_t tkl;
};
/**
* @brief Representation of a CoAP packet.
*/
struct zoap_packet {
struct net_pkt *pkt;
u8_t *start; /* Start of the payload */
u16_t total_size;
};
/**
* @typedef zoap_reply_t
* @brief Helper function to be called when a response matches the
* a pending request.
*/
typedef int (*zoap_reply_t)(const struct zoap_packet *response,
struct zoap_reply *reply,
const struct sockaddr *from);
/**
* @brief Represents a request awaiting for an acknowledgment (ACK).
*/
struct zoap_pending {
struct net_pkt *pkt;
struct sockaddr addr;
s32_t timeout;
u16_t id;
};
/**
* @brief Represents the handler for the reply of a request, it is
* also used when observing resources.
*/
struct zoap_reply {
zoap_reply_t reply;
void *user_data;
int age;
u8_t token[8];
u16_t id;
u8_t tkl;
};
/**
* @brief Indicates that the remote device referenced by @a addr, with
* @a request, wants to observe a resource.
*
* @param observer Observer to be initialized
* @param request Request on which the observer will be based
* @param addr Address of the remote device
*/
void zoap_observer_init(struct zoap_observer *observer,
const struct zoap_packet *request,
const struct sockaddr *addr);
/**
* @brief After the observer is initialized, associate the observer
* with an resource.
*
* @param resource Resource to add an observer
* @param observer Observer to be added
*
* @return true if this is the first observer added to this resource.
*/
bool zoap_register_observer(struct zoap_resource *resource,
struct zoap_observer *observer);
/**
* @brief Remove this observer from the list of registered observers
* of that resource.
*
* @param resource Resource in which to remove the observer
* @param observer Observer to be removed
*/
void zoap_remove_observer(struct zoap_resource *resource,
struct zoap_observer *observer);
/**
* @brief Returns the observer that matches address @a addr.
*
* @param observers Pointer to the array of observers
* @param len Size of the array of observers
* @param addr Address of the endpoint observing a resource
*
* @return A pointer to a observer if a match is found, NULL
* otherwise.
*/
struct zoap_observer *zoap_find_observer_by_addr(
struct zoap_observer *observers, size_t len,
const struct sockaddr *addr);
/**
* @brief Returns the next available observer representation.
*
* @param observers Pointer to the array of observers
* @param len Size of the array of observers
*
* @return A pointer to a observer if there's an available observer,
* NULL otherwise.
*/
struct zoap_observer *zoap_observer_next_unused(
struct zoap_observer *observers, size_t len);
/**
* @brief Indicates that a reply is expected for @a request.
*
* @param reply Reply structure to be initialized
* @param request Request from which @a reply will be based
*/
void zoap_reply_init(struct zoap_reply *reply,
const struct zoap_packet *request);
/**
* @brief Represents the value of a CoAP option.
*
* To be used with zoap_find_options().
*/
struct zoap_option {
u8_t *value;
u16_t len;
};
/**
* @brief Parses the CoAP packet in @a pkt, validating it and
* initializing @a zpkt. @a pkt must remain valid while @a zpkt is used.
*
* @param zpkt Packet to be initialized from received @a pkt.
* @param pkt Network Packet containing a CoAP packet, its @a data pointer is
* positioned on the start of the CoAP packet.
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_packet_parse(struct zoap_packet *zpkt, struct net_pkt *pkt);
/**
* @brief Creates a new CoAP packet from a net_pkt. @a pkt must remain
* valid while @a zpkt is used.
*
* @param zpkt New packet to be initialized using the storage from @a
* pkt.
* @param pkt Network Packet that will contain a CoAP packet
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_packet_init(struct zoap_packet *zpkt, struct net_pkt *pkt);
/**
* @brief Initialize a pending request with a request.
*
* The request's fields are copied into the pending struct, so @a
* request doesn't have to live for as long as the pending struct
* lives, but net_pkt needs to live for at least that long.
*
* @param pending Structure representing the waiting for a
* confirmation message, initialized with data from @a request
* @param request Message waiting for confirmation
* @param addr Address to send the retransmission
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_pending_init(struct zoap_pending *pending,
const struct zoap_packet *request,
const struct sockaddr *addr);
/**
* @brief Returns the next available pending struct, that can be used
* to track the retransmission status of a request.
*
* @param pendings Pointer to the array of #zoap_pending structures
* @param len Size of the array of #zoap_pending structures
*
* @return pointer to a free #zoap_pending structure, NULL in case
* none could be found.
*/
struct zoap_pending *zoap_pending_next_unused(
struct zoap_pending *pendings, size_t len);
/**
* @brief Returns the next available reply struct, so it can be used
* to track replies and notifications received.
*
* @param replies Pointer to the array of #zoap_reply structures
* @param len Size of the array of #zoap_reply structures
*
* @return pointer to a free #zoap_reply structure, NULL in case
* none could be found.
*/
struct zoap_reply *zoap_reply_next_unused(
struct zoap_reply *replies, size_t len);
/**
* @brief After a response is received, clear all pending
* retransmissions related to that response.
*
* @param response The received response
* @param pendings Pointer to the array of #zoap_reply structures
* @param len Size of the array of #zoap_reply structures
*
* @return pointer to the associated #zoap_pending structure, NULL in
* case none could be found.
*/
struct zoap_pending *zoap_pending_received(
const struct zoap_packet *response,
struct zoap_pending *pendings, size_t len);
/**
* @brief After a response is received, call zoap_reply_t handler
* registered in #zoap_reply structure
*
* @param response A response received
* @param from Address from which the response was received
* @param replies Pointer to the array of #zoap_reply structures
* @param len Size of the array of #zoap_reply structures
*
* @return Pointer to the reply matching the packet received, NULL if
* none could be found.
*/
struct zoap_reply *zoap_response_received(
const struct zoap_packet *response,
const struct sockaddr *from,
struct zoap_reply *replies, size_t len);
/**
* @brief Returns the next pending about to expire, pending->timeout
* informs how many ms to next expiration.
*
* @param pendings Pointer to the array of #zoap_pending structures
* @param len Size of the array of #zoap_pending structures
*
* @return The next #zoap_pending to expire, NULL if none is about to
* expire.
*/
struct zoap_pending *zoap_pending_next_to_expire(
struct zoap_pending *pendings, size_t len);
/**
* @brief After a request is sent, user may want to cycle the pending
* retransmission so the timeout is updated.
*
* @param pending Pending representation to have its timeout updated
*
* @return false if this is the last retransmission.
*/
bool zoap_pending_cycle(struct zoap_pending *pending);
/**
* @brief Cancels the pending retransmission, so it again becomes
* available.
*
* @param pending Pending representation to be canceled
*/
void zoap_pending_clear(struct zoap_pending *pending);
/**
* @brief Cancels awaiting for this reply, so it becomes available
* again.
*
* @param reply The reply to be canceled
*/
void zoap_reply_clear(struct zoap_reply *reply);
/**
* @brief When a request is received, call the appropriate methods of
* the matching resources.
*
* @param zpkt Packet received
* @param resources Array of known resources
* @param from Address from which the packet was received
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_handle_request(struct zoap_packet *zpkt,
struct zoap_resource *resources,
const struct sockaddr *from);
/**
* @brief Indicates that this resource was updated and that the @a
* notify callback should be called for every registered observer.
*
* @param resource Resource that was updated
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_resource_notify(struct zoap_resource *resource);
/**
* @brief Returns if this request is enabling observing a resource.
*
* @param request Request to be checked
*
* @return True if the request is enabling observing a resource, False
* otherwise
*/
bool zoap_request_is_observe(const struct zoap_packet *request);
/**
* @brief Returns a pointer to the start of the payload and its size
*
* It will insert the COAP_MARKER (0xFF), if its not set, and return the
* available size for the payload.
*
* @param zpkt Packet to get (or insert) the payload
* @param len Amount of space for the payload
*
* @return pointer to the start of the payload, NULL in case of error.
*/
u8_t *zoap_packet_get_payload(struct zoap_packet *zpkt, u16_t *len);
/**
* @brief Sets how much space was used by the payload.
*
* Used for outgoing packets, after zoap_packet_get_payload(), to
* update the internal representation with the amount of data that was
* added to the packet.
*
* @param zpkt Packet to be updated
* @param len Amount of data that was added to the payload
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_packet_set_used(struct zoap_packet *zpkt, u16_t len);
/**
* @brief Adds an option to the packet.
*
* Note: options must be added in numeric order of their codes.
*
* @param zpkt Packet to be updated
* @param code Option code to add to the packet, see #zoap_option_num
* @param value Pointer to the value of the option, will be copied to the packet
* @param len Size of the data to be added
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_add_option(struct zoap_packet *zpkt, u16_t code,
const void *value, u16_t len);
/**
* @brief Converts an option to its integer representation.
*
* Assumes that the number is encoded in the network byte order in the
* option.
*
* @param option Pointer to the option value, retrieved by
* zoap_find_options()
*
* @return The integer representation of the option
*/
unsigned int zoap_option_value_to_int(const struct zoap_option *option);
/**
* @brief Adds an integer value option to the packet.
*
* The option must be added in numeric order of their codes, and the
* least amount of bytes will be used to encode the value.
*
* @param zpkt Packet to be updated
* @param code Option code to add to the packet, see #zoap_option_num
* @param val Integer value to be added
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_add_option_int(struct zoap_packet *zpkt, u16_t code,
unsigned int val);
/**
* @brief Return the values associated with the option of value @a
* code.
*
* @param zpkt CoAP packet representation
* @param code Option number to look for
* @param options Array of #zoap_option where to store the value
* of the options found
* @param veclen Number of elements in the options array
*
* @return The number of options found in packet matching code,
* negative on error.
*/
int zoap_find_options(const struct zoap_packet *zpkt, u16_t code,
struct zoap_option *options, u16_t veclen);
/**
* Represents the size of each block that will be transferred using
* block-wise transfers [RFC7959]:
*
* Each entry maps directly to the value that is used in the wire.
*
* https://tools.ietf.org/html/rfc7959
*/
enum zoap_block_size {
ZOAP_BLOCK_16,
ZOAP_BLOCK_32,
ZOAP_BLOCK_64,
ZOAP_BLOCK_128,
ZOAP_BLOCK_256,
ZOAP_BLOCK_512,
ZOAP_BLOCK_1024,
};
/**
* @brief Helper for converting the enumeration to the size expressed
* in bytes.
*
* @param block_size The block size to be converted
*
* @return The size in bytes that the block_size represents
*/
static inline u16_t zoap_block_size_to_bytes(
enum zoap_block_size block_size)
{
return (1 << (block_size + 4));
}
/**
* @brief Represents the current state of a block-wise transaction.
*/
struct zoap_block_context {
size_t total_size;
size_t current;
enum zoap_block_size block_size;
};
/**
* @brief Initializes the context of a block-wise transfer.
*
* @param ctx The context to be initialized
* @param block_size The size of the block
* @param total_size The total size of the transfer, if known
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_block_transfer_init(struct zoap_block_context *ctx,
enum zoap_block_size block_size,
size_t total_size);
/**
* @brief Add BLOCK1 option to the packet.
*
* @param zpkt Packet to be updated
* @param ctx Block context from which to retrieve the
* information for the Block1 option
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_add_block1_option(struct zoap_packet *zpkt,
struct zoap_block_context *ctx);
/**
* @brief Add BLOCK2 option to the packet.
*
* @param zpkt Packet to be updated
* @param ctx Block context from which to retrieve the
* information for the Block2 option
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_add_block2_option(struct zoap_packet *zpkt,
struct zoap_block_context *ctx);
/**
* @brief Add SIZE1 option to the packet.
*
* @param zpkt Packet to be updated
* @param ctx Block context from which to retrieve the
* information for the Size1 option
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_add_size1_option(struct zoap_packet *zpkt,
struct zoap_block_context *ctx);
/**
* @brief Add SIZE2 option to the packet.
*
* @param zpkt Packet to be updated
* @param ctx Block context from which to retrieve the
* information for the Size2 option
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_add_size2_option(struct zoap_packet *zpkt,
struct zoap_block_context *ctx);
/**
* @brief Retrieves BLOCK{1,2} and SIZE{1,2} from @a zpkt and updates
* @a ctx accordingly.
*
* @param zpkt Packet in which to look for block-wise transfers options
* @param ctx Block context to be updated
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_update_from_block(const struct zoap_packet *zpkt,
struct zoap_block_context *ctx);
/**
* @brief Updates @a ctx so after this is called the current entry
* indicates the correct offset in the body of data being
* transferred.
*
* @param zpkt Packet in which to look for block-wise transfers options
* @param ctx Block context to be updated
*
* @return The offset in the block-wise transfer, 0 if the transfer
* has finished.
*/
size_t zoap_next_block(const struct zoap_packet *zpkt,
struct zoap_block_context *ctx);
/**
* @brief Returns the version present in a CoAP packet.
*
* @param zpkt CoAP packet representation
*
* @return the CoAP version in packet
*/
u8_t zoap_header_get_version(const struct zoap_packet *zpkt);
/**
* @brief Returns the type of the CoAP packet.
*
* @param zpkt CoAP packet representation
*
* @return the type of the packet
*/
u8_t zoap_header_get_type(const struct zoap_packet *zpkt);
/**
* @brief Returns the token (if any) in the CoAP packet.
*
* @param zpkt CoAP packet representation
* @param len Where to store the length of the token
*
* @return pointer to the start of the token in the CoAP packet.
*/
const u8_t *zoap_header_get_token(const struct zoap_packet *zpkt,
u8_t *len);
/**
* @brief Returns the code of the CoAP packet.
*
* @param zpkt CoAP packet representation
*
* @return the code present in the packet
*/
u8_t zoap_header_get_code(const struct zoap_packet *zpkt);
/**
* @brief Returns the message id associated with the CoAP packet.
*
* @param zpkt CoAP packet representation
*
* @return the message id present in the packet
*/
u16_t zoap_header_get_id(const struct zoap_packet *zpkt);
/**
* @brief Sets the version of the CoAP packet.
*
* @param zpkt CoAP packet representation
* @param ver The CoAP version to set in the packet
*/
void zoap_header_set_version(struct zoap_packet *zpkt, u8_t ver);
/**
* @brief Sets the type of the CoAP packet.
*
* @param zpkt CoAP packet representation
* @param type The packet type to set
*/
void zoap_header_set_type(struct zoap_packet *zpkt, u8_t type);
/**
* @brief Sets the token in the CoAP packet.
*
* @param zpkt CoAP packet representation
* @param token Token to set in the packet, will be copied
* @param tokenlen Size of the token to be set, 8 bytes maximum
*
* @return 0 in case of success or negative in case of error.
*/
int zoap_header_set_token(struct zoap_packet *zpkt, const u8_t *token,
u8_t tokenlen);
/**
* @brief Sets the code present in the CoAP packet.
*
* @param zpkt CoAP packet representation
* @param code The code set in the packet
*/
void zoap_header_set_code(struct zoap_packet *zpkt, u8_t code);
/**
* @brief Sets the message id present in the CoAP packet.
*
* @param zpkt CoAP packet representation
* @param id The message id to set in the packet
*/
void zoap_header_set_id(struct zoap_packet *zpkt, u16_t id);
/**
* @brief Helper to generate message ids
*
* @return a new message id
*/
static inline u16_t zoap_next_id(void)
{
static u16_t message_id;
return ++message_id;
}
/**
* @brief Returns a randomly generated array of 8 bytes, that can be
* used as a message's token.
*
* @return a 8-byte pseudo-random token.
*/
u8_t *zoap_next_token(void);
/**
* @}
*/
#ifdef __cplusplus
}
#endif
#endif /* __ZOAP_H__ */