mirror of
https://github.com/obgm/libcoap.git
synced 2026-11-01 15:35:46 +03:00
Jon Shallow
37334b120f
Add in new coap_proxy_fwd_add_client_session() function to define the upstream servers from previously set up sessions (i.e. from call-home).
261 lines
11 KiB
C
261 lines
11 KiB
C
/*
|
|
* coap_proxy.h -- helper functions for proxy handling
|
|
*
|
|
* Copyright (C) 2024-2026 Jon Shallow <supjps-libcoap@jpshallow.com>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*
|
|
* This file is part of the CoAP library libcoap. Please see README for terms
|
|
* of use.
|
|
*/
|
|
|
|
/**
|
|
* @file coap_proxy.h
|
|
* @brief Helper functions for proxy handling
|
|
*/
|
|
|
|
#ifndef COAP_PROXY_H_
|
|
#define COAP_PROXY_H_
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/**
|
|
* @ingroup application_api
|
|
* @defgroup proxy Proxy
|
|
* API for Proxies
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* coap_proxy_t Proxy definitions.
|
|
*
|
|
* 0x00000007 Old 4.3.5 mappings for backward compatability.
|
|
* 0x00000038 New type mappings.
|
|
* 0xffffffc0 Bitwise optional actions.
|
|
*
|
|
* Three types of proxy.
|
|
* reverse Traffic forward to internal set of servers.
|
|
* forward-static Traffic forwarded to defined set of servers.
|
|
* forward-dynamic Traffic forwarded to host defined by
|
|
* Proxy-Uri / Proxy-Scheme options.
|
|
* Additional options for each proxy type.
|
|
* strip Remove Proxy-Uri and/or Proxy-Scheme options.
|
|
* mcast Support forward-dynamic traffic to multicast addresses.
|
|
*/
|
|
|
|
typedef enum {
|
|
/* Old entries, now updated for flexibility */
|
|
COAP_PROXY_REVERSE, /**< Old - do not use - Act as a reverse proxy */
|
|
COAP_PROXY_REVERSE_STRIP, /**< Old - do not use - Act as a reverse proxy,
|
|
strip out proxy options */
|
|
COAP_PROXY_FORWARD, /**< Old - do not use - Act as a forward-static proxy */
|
|
COAP_PROXY_FORWARD_STRIP, /**< Old - do not use - Act as a forward-static proxy,
|
|
strip out proxy options */
|
|
COAP_PROXY_DIRECT, /**< Old - do not use - Act as a forward-dynamic proxy */
|
|
COAP_PROXY_DIRECT_STRIP, /**< Old - do not use - Act as a forward-dynamic proxy,
|
|
strip out proxy options */
|
|
COAP_PROXY_FORWARD_DYNAMIC = COAP_PROXY_DIRECT,
|
|
/**< Old - do not use - Act as a forward-dynamic proxy */
|
|
COAP_PROXY_FORWARD_DYNAMIC_STRIP = COAP_PROXY_DIRECT_STRIP,
|
|
/**< Old - do not use - Act as a forward-dynamic proxy, strip out proxy options */
|
|
|
|
|
|
/* New style Proxy types */
|
|
COAP_PROXY_REV = (1 << 3), /**< reverse proxy. */
|
|
COAP_PROXY_FWD_STATIC = (2 << 3), /**< forward-static proxy. */
|
|
COAP_PROXY_FWD_DYNAMIC = (3 << 3), /**< forward-dynamic proxy. */
|
|
|
|
/* Start of additional optional bit mask mapping */
|
|
COAP_PROXY_BIT_STRIP = (1 << 6),
|
|
/**<
|
|
* If COAP_PROXY_BIT_STRIP set, then remove any Proxy-Uri or Proxy-Scheme,
|
|
* else leave them.
|
|
*/
|
|
COAP_PROXY_BIT_MCAST = (1 << 7),
|
|
/**<
|
|
* If COAP_PROXY_BIT_MCAST set, then upstream servers can be multicast,
|
|
* else only unicast.
|
|
* [ Ignored if not COAP_PROXY_FWD_DYNAMIC ]
|
|
*/
|
|
COAP_PROXY_DYN_DEFINED = (1 << 8),
|
|
/**<
|
|
* If COAP_PROXY_DYN_DEFINED set, then no new dynamic upstream servers will get
|
|
* automatically added. All dynamic upstream servers mut be pre-allocated by
|
|
* using coap_proxy_fwd_add_client_session().
|
|
* [ Ignored if not COAP_PROXY_FWD_DYNAMIC ]
|
|
*/
|
|
} coap_proxy_t;
|
|
|
|
#define COAP_PROXY_OLD_MASK 0x07 /**< Space used in coap_proxy_t for old types */
|
|
#define COAP_PROXY_NEW_MASK 0x38 /**< Space used in coap_proxy_t for new types */
|
|
|
|
typedef struct coap_proxy_server_t {
|
|
coap_uri_t uri; /**< host and port define the server, scheme method */
|
|
coap_dtls_pki_t *dtls_pki; /**< PKI configuration to use if not NULL */
|
|
coap_dtls_cpsk_t *dtls_cpsk; /**< PSK configuration to use if not NULL */
|
|
coap_oscore_conf_t *oscore_conf; /**< OSCORE configuration if not NULL */
|
|
} coap_proxy_server_t;
|
|
|
|
typedef struct coap_proxy_server_list_t {
|
|
coap_proxy_server_t *entry; /**< Set of servers to connect to */
|
|
size_t entry_count; /**< The number of servers in entry list */
|
|
size_t next_entry; /**< Next server to use (% entry_count) */
|
|
coap_proxy_t type; /**< The proxy type and option controlling bits
|
|
(if old type used, will get mapped into new + bits */
|
|
int track_client_session; /**< If 1, track individual connections to upstream
|
|
server, else 0 for all clients to be multiplexed
|
|
over the same upstream session */
|
|
unsigned int idle_timeout_secs; /**< Proxy upstream session idle timeout
|
|
(0 is no timeout). Timeout is ignored
|
|
if there are any active upstream Observe
|
|
requests */
|
|
} coap_proxy_server_list_t;
|
|
|
|
/**
|
|
* Proxy response handler that is used as callback held in coap_context_t.
|
|
*
|
|
* @param session CoAP session.
|
|
* @param sent The PDU that was transmitted.
|
|
* @param received The response PDU that was received, or returned from cache.
|
|
* @param cache_key Updated with the cache key pointer provided to
|
|
* coap_proxy_forward_request(). The caller should
|
|
* delete this cache key (unless the client request set up an
|
|
* Observe and there will be unsolicited responses).
|
|
*
|
|
* @return The PDU to be sent back to the client (usually @c received) or NULL
|
|
* if error. If NULL, this will cause sending a RST packet to the
|
|
* upstream server if the received PDU is a CON or NON.
|
|
* If the returned PDU is not @c received or @c NULL, then @c received
|
|
* must be freed off in the handler.
|
|
*/
|
|
typedef coap_pdu_t *(*coap_proxy_response_handler_t)(coap_session_t *session,
|
|
const coap_pdu_t *sent,
|
|
coap_pdu_t *received,
|
|
coap_cache_key_t *cache_key);
|
|
|
|
/**
|
|
* Registers a new message handler that is called whenever a response is
|
|
* received by the proxy logic.
|
|
*
|
|
* Note: If this is not defined, then the handler registered by
|
|
* coap_register_response_handler() will be used.
|
|
*
|
|
* @param context The context to register the handler for.
|
|
* @param handler The response handler to register.
|
|
*/
|
|
void coap_register_proxy_response_handler(coap_context_t *context,
|
|
coap_proxy_response_handler_t handler);
|
|
|
|
/**
|
|
* Verify that the CoAP Scheme is supported for an ongoing proxy connection.
|
|
*
|
|
* @param scheme The CoAP scheme to check.
|
|
*
|
|
* @return @c 1 if supported, or @c 0 if not supported.
|
|
*/
|
|
int coap_verify_proxy_scheme_supported(coap_uri_scheme_t scheme);
|
|
|
|
/**
|
|
* Forward incoming request upstream to the next proxy/server.
|
|
*
|
|
* Possible scenarios:
|
|
* Acting as a reverse proxy - connect to defined internal server
|
|
* (possibly round robin load balancing over multiple servers).
|
|
* Acting as a forward-dynamic proxy - connect to host defined in Proxy-Uri
|
|
* or Proxy-Scheme with Uri-Host (and maybe Uri-Port).
|
|
* Acting as a forward-static proxy - connect to defined upstream server
|
|
* (possibly round robin load balancing over multiple servers).
|
|
*
|
|
* A request that should go direct to this next proxy/server is not
|
|
* supported using this function - set up a new session using
|
|
* coap_new_client_session_proxy().
|
|
*
|
|
* @param req_session The client session.
|
|
* @param request The client's request PDU.
|
|
* @param response The response PDU that will get sent back to the client.
|
|
* @param resource The resource associated with this request.
|
|
* @param cache_key A cache key generated from the request PDU or NULL.
|
|
* @param server_list The upstream server list to connect to.
|
|
*
|
|
* @return @c 1 if success, or @c 0 if failure (@p response code set to
|
|
* appropriate value).
|
|
*/
|
|
COAP_API int coap_proxy_forward_request(coap_session_t *req_session,
|
|
const coap_pdu_t *request,
|
|
coap_pdu_t *response,
|
|
coap_resource_t *resource,
|
|
coap_cache_key_t *cache_key,
|
|
coap_proxy_server_list_t *server_list);
|
|
|
|
/**
|
|
* Forward the returning response back to the appropriate client.
|
|
*
|
|
* @param rsp_session The upstream session receiving the response.
|
|
* @param received The received PDU.
|
|
* @param cache_key Updated with the cache key pointer provided to
|
|
* coap_proxy_forward_request(). The caller should
|
|
* delete this cache key (unless the client request set up an
|
|
* Observe and there will be unsolicited responses).
|
|
*
|
|
* @return One of COAP_RESPONSE_FAIL or COAP_RESPONSE_OK.
|
|
*/
|
|
coap_response_t COAP_API coap_proxy_forward_response(coap_session_t *rsp_session,
|
|
const coap_pdu_t *received,
|
|
coap_cache_key_t **cache_key);
|
|
|
|
/**
|
|
* Creates a new client session to use the proxy logic going to the defined upstream
|
|
* server.
|
|
*
|
|
* Note: If server_list contains more than one server, the first server is not always
|
|
* chosen.
|
|
*
|
|
* Note: @p server_list must exist for the duration of the returned session as it is
|
|
* used for every *coap_send*() or *coap_send_recv*().
|
|
*
|
|
* Note: Unless coap_send_recv() is used, the response is sent to the handler defined
|
|
* by coap_register_response_handler(), not to the handler defined by
|
|
* coap_register_proxy_response_handler().
|
|
*
|
|
* @param context The CoAP context.
|
|
* @param server_list The upstream server list to connect to.
|
|
*
|
|
* @return A new CoAP session or NULL if failed. Call coap_session_release() to free.
|
|
*/
|
|
COAP_API coap_session_t *coap_new_client_session_proxy(coap_context_t *context,
|
|
coap_proxy_server_list_t *server_list);
|
|
|
|
/**
|
|
* Add a previously setup proxy-client session to use the proxy logic for forwarding
|
|
* subsequent dynamic proxy requests.
|
|
*
|
|
* The upstream server information is derived from @p session for the remote IP and
|
|
* @p use_port for the port, and proxy connection type is derived from @p server_list
|
|
* (track_client_session, and idle_timeout_secs are ignored and set to 0 and 0
|
|
* respectively). type must contain at least COAP_PROXY_FWD_DYNAMIC, and @p server_list
|
|
* must be the same as used in coap_proxy_forward_request().
|
|
*
|
|
* @param session The CoAP upstream proxy session previosly set up (e.g. via call-home).
|
|
* @param use_ip The IP address to match on incoming proxy requests. If NULL, then
|
|
* the IP address is determined from @p session.
|
|
* @param use_port The port number to match on incoming proxy requests. If 0, default
|
|
* port for protocol is used.
|
|
* @param server_list The upstream server connection characteristics.
|
|
*
|
|
* @return the proxy entry on success in adding session to the proxy list of upstream
|
|
* servers, else NULL.
|
|
*/
|
|
COAP_API coap_proxy_entry_t *coap_proxy_fwd_add_client_session(coap_session_t *session,
|
|
const char *use_ip, uint16_t use_port,
|
|
coap_proxy_server_list_t *server_list);
|
|
|
|
/** @} */
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* COAP_PROXY_H_ */
|