'\" t .\" Title: coap_resource .\" Author: [see the "AUTHORS" section] .\" Generator: DocBook XSL Stylesheets vsnapshot .\" Date: 10/28/2023 .\" Manual: libcoap Manual .\" Source: coap_resource 4.3.4 .\" Language: English .\" .TH "COAP_RESOURCE" "3" "10/28/2023" "coap_resource 4\&.3\&.4" "libcoap Manual" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" coap_resource, coap_resource_init, coap_resource_unknown_init, coap_resource_unknown_init2, coap_resource_proxy_uri_init, coap_resource_proxy_uri_init2, coap_add_resource, coap_delete_resource, coap_resource_set_mode, coap_resource_set_userdata, coap_resource_get_userdata, coap_resource_release_userdata_handler, coap_resource_get_uri_path \- Work with CoAP resources .SH "SYNOPSIS" .sp \fB#include \fR .sp \fBcoap_resource_t *coap_resource_init(coap_str_const_t *\fR\fB\fIuri_path\fR\fR\fB, int \fR\fB\fIflags\fR\fR\fB);\fR .sp \fBcoap_resource_t *coap_resource_unknown_init(coap_method_handler_t \fR\fB\fIput_handler\fR\fR\fB);\fR .sp \fBcoap_resource_t *coap_resource_unknown_init2(coap_method_handler_t \fR\fB\fIput_handler\fR\fR\fB, int \fR\fB\fIflags\fR\fR\fB);\fR .sp \fBcoap_resource_t *coap_resource_proxy_uri_init(coap_method_handler_t \fR\fB\fIproxy_handler\fR\fR\fB, size_t \fR\fB\fIhost_name_count\fR\fR\fB, const char *\fR\fB\fIhost_name_list\fR\fR\fB[]);\fR .sp \fBcoap_resource_t *coap_resource_proxy_uri_init2(coap_method_handler_t \fR\fB\fIproxy_handler\fR\fR\fB, size_t \fR\fB\fIhost_name_count\fR\fR\fB, const char *\fR\fB\fIhost_name_list\fR\fR\fB[], int \fR\fB\fIflags\fR\fR\fB);\fR .sp \fBvoid coap_add_resource(coap_context_t *\fR\fB\fIcontext\fR\fR\fB, coap_resource_t *\fR\fB\fIresource\fR\fR\fB);\fR .sp \fBint coap_delete_resource(coap_context_t *\fR\fB\fIcontext\fR\fR\fB, coap_resource_t *\fR\fB\fIresource\fR\fR\fB);\fR .sp \fBvoid coap_resource_set_mode(coap_resource_t *\fR\fB\fIresource\fR\fR\fB, int \fR\fB\fImode\fR\fR\fB);\fR .sp \fBvoid coap_resource_set_userdata(coap_resource_t *\fR\fB\fIresource\fR\fR\fB, void *\fR\fB\fIdata\fR\fR\fB);\fR .sp \fBvoid *coap_resource_get_userdata(coap_resource_t *\fR\fB\fIresource\fR\fR\fB);\fR .sp \fBvoid coap_resource_release_userdata_handler(coap_context_t *\fR\fB\fIcontext\fR\fR\fB, coap_resource_release_userdata_handler_t \fR\fB\fIcallback\fR\fR\fB);\fR .sp \fBcoap_str_const_t *coap_resource_get_uri_path(coap_resource_t *\fR\fB\fIresource\fR\fR\fB);\fR .sp For specific (D)TLS library support, link with \fB\-lcoap\-3\-notls\fR, \fB\-lcoap\-3\-gnutls\fR, \fB\-lcoap\-3\-openssl\fR, \fB\-lcoap\-3\-mbedtls\fR or \fB\-lcoap\-3\-tinydtls\fR\&. Otherwise, link with \fB\-lcoap\-3\fR to get the default (D)TLS library support\&. .SH "DESCRIPTION" .sp CoAP Resources on a CoAP Server need to be created, updated and deleted as appropriate\&. The URI in the request packet defines the resource to work with, with possibly the Query or data in the request referring to a sub\-resource\&. .sp When resources are configured on the CoAP server, the URI to match against in the request packet is specified\&. .sp Callback Handlers are then added to the resource to handle the different request methods\&. See \fBcoap_register_request_handler\fR(3) for further information\&. .sp Adding Attributes allows textual information to be added to the resource which can then be reported back to any client doing a "GET \&.well\-known/core" request\&. See \fBcoap_add_attr\fR(3) for further information\&. .sp If an incoming packet request matches a resource\(cqs URI and Method, then the appropriate callback resource handler is invoked to process the packet which should then update a suitable response packet for returning back to the requester\&. .sp There is support for handling incoming packets where the URI is unknown (no specific resource has been created)\&. This could, for example, happen when a PUT request is trying to create a new resource\&. It is the responsibility of the unknown resource callback handler to either create a new resource for the URI or just manage things separately\&. .sp CoAP Observe (RFC7641) is not supported for unknown resources, so a new resource with GET handler must be created by the unknown resource callback handle matching the URI which then can be Observable\&. .sp There is support for handling incoming proxy based requests using the Proxy\-Uri or Proxy\-Scheme options\&. .SH "FUNCTIONS" .sp \fBFunction: coap_resource_init()\fR .sp The \fBcoap_resource_init\fR() function returns a newly created \fIresource\fR of type \fIcoap_resource_t\fR * \&. \fIuri_path\fR specifies the uri string path to match against\&. Normally there is no need for the leading \fI/\fR \- e\&.g\&. just "full/path/for/resource"\&. \fIflags\fR can be zero or more of the following definitions or\(cqed together\&. .TS tab(:); lt lt lt lt lt lt lt lt lt lt lt lt. T{ .sp \fBCOAP_RESOURCE_FLAGS_NOTIFY_NON\fR T}:T{ .sp Set the notification message type to non\-confirmable for any trigggered "observe" responses with type set to confirmable every 5 packets as required by "RFC7641 4\&.5\&. Transmission"\&. See \fBcoap_observe\fR(3)\&. \fBNOTE:\fR This flag is ignored if COAP_RESOURCE_FLAGS_NOTIFY_CON is set\&. T} T{ .sp \fBCOAP_RESOURCE_FLAGS_NOTIFY_NON_ALWAYS\fR T}:T{ .sp Set the notification message type to always non\-confirmable for any trigggered "observe" responses\&. This should only be used if a upper layer protocol requires it\&. See \fBcoap_observe\fR(3)\&. \fBNOTE:\fR This flag is ignored if COAP_RESOURCE_FLAGS_NOTIFY_CON is set\&. T} T{ .sp \fBCOAP_RESOURCE_FLAGS_NOTIFY_CON\fR T}:T{ .sp Set the notification message type to confirmable for any trigggered "observe" responses\&. See \fBcoap_observe\fR(3)\&. \fBNOTE:\fR COAP_RESOURCE_FLAGS_NOTIFY_NON is assumed if COAP_RESOURCE_FLAGS_NOTIFY_CON is not set\&. T} T{ .sp \fBCOAP_RESOURCE_FLAGS_RELEASE_URI\fR T}:T{ .sp Free off the coap_str_const_t for \fIuri_path\fR when the \fIresource\fR is deleted\&. T} T{ .sp \fBCOAP_RESOURCE_FLAGS_FORCE_SINGLE_BODY\fR T}:T{ .sp Force all large traffic to this resource to be presented as a single body to the request handler\&. T} T{ .sp \fBCOAP_RESOURCE_FLAGS_OSCORE_ONLY\fR T}:T{ .sp Define this resource as an OSCORE enabled access only\&. T} .TE .sp 1 .sp \fBNOTE:\fR The following flags are only tested against if \fBcoap_mcast_per_resource\fR() has been called\&. If \fBcoap_mcast_per_resource\fR() has not been called, then all resources have multicast support, libcoap adds in random delays to the responses, and 4\&.xx / 5\&.xx responses are dropped\&. .sp \fBNOTE:\fR The pseudo resource for "\&.well\-known/core" always has multicast support enabled and is not configurable\&. .TS tab(:); lt lt lt lt lt lt lt lt lt lt lt lt. T{ .sp \fBCOAP_RESOURCE_FLAGS_HAS_MCAST_SUPPORT\fR T}:T{ .sp This resource has support for multicast requests\&. T} T{ .sp \fBCOAP_RESOURCE_FLAGS_LIB_DIS_MCAST_DELAYS\fR T}:T{ .sp Disable libcoap library from adding in delays to multicast requests before sending the response back to the client\&. It is then the responsibility of the app to delay the responses for multicast requests\&. See "RFC7252 8\&.2\&. Request/Response Layer"\&. However, the pseudo resource for "\&.well\-known/core" always has multicast support enabled\&. T} T{ .sp \fBCOAP_RESOURCE_FLAGS_LIB_ENA_MCAST_SUPPRESS_2_05\fR T}:T{ .sp Enable libcoap library suppression of 205 multicast responses that are empty (overridden by RFC7967 No\-Response option) for multicast requests\&. T} T{ .sp \fBCOAP_RESOURCE_FLAGS_LIB_ENA_MCAST_SUPPRESS_2_XX\fR T}:T{ .sp Enable libcoap library suppressing 2\&.xx multicast responses (overridden by RFC7967 No\-Response option) for multicast requests\&. T} T{ .sp \fBCOAP_RESOURCE_FLAGS_LIB_DIS_MCAST_SUPPRESS_4_XX\fR T}:T{ .sp Disable libcoap library suppressing 4\&.xx multicast responses (overridden by RFC7967 No\-Response option) for multicast requests\&. T} T{ .sp \fBCOAP_RESOURCE_FLAGS_LIB_DIS_MCAST_SUPPRESS_5_XX\fR T}:T{ .sp Disable libcoap library suppressing 5\&.xx multicast responses (overridden by RFC7967 No\-Response option) for multicast requests\&. T} .TE .sp 1 .sp \fBNOTE:\fR \fIuri_path\fR, if not 7 bit readable ASCII, binary bytes must be hex encoded according to the rules defined in "RFC3986 2\&.1\&. Percent\-Encoding"\&. .sp \fBFunction: coap_resource_unknown_init()\fR .sp The \fBcoap_resource_unknown_init\fR() function returns a newly created \fIresource\fR of type \fIcoap_resource_t\fR *\&. \fIput_handler\fR is automatically added to the \fIresource\fR to handle PUT requests to resources that are unknown\&. Additional handlers can be added to this resource if required\&. .sp \fBFunction: coap_resource_unknown_init2()\fR .sp The \fBcoap_resource_unknown_init2\fR() function returns a newly created \fIresource\fR of type \fIcoap_resource_t\fR *\&. \fIput_handler\fR is automatically added to the \fIresource\fR to handle PUT requests to resources that are unknown\&. Additional handlers can be added to this resource if required\&. \fIflags\fR can be zero or more of the COAP_RESOURCE_FLAGS MCAST definitions\&. .sp \fBFunction: coap_resource_proxy_uri_init()\fR .sp The \fBcoap_resource_proxy_uri_init\fR() function returns a newly created \fIresource\fR of type \fIcoap_resource_t\fR *\&. \fIproxy_handler\fR is automatically added to the \fIresource\fR to handle PUT/POST/GET etc\&. requests that use the Proxy\-Uri option\&. There is no need to add explicit request type handlers\&. One or more names by which the proxy is known by (IP address, DNS name etc\&.) must be supplied in the array defined by \fIhost_name_list\fR[] which has a count of \fIhost_name_count\fR\&. This is used to check whether the current endpoint is the proxy target address, or the request has to be passed on to an upstream server\&. .sp \fBFunction: coap_resource_proxy_uri_init2()\fR .sp The \fBcoap_resource_proxy_uri_init2\fR() function returns a newly created \fIresource\fR of type \fIcoap_resource_t\fR *\&. \fIproxy_handler\fR is automatically added to the \fIresource\fR to handle PUT/POST/GET etc\&. requests that use the Proxy\-Uri option\&. There is no need to add explicit request type handlers\&. One or more names by which the proxy is known by (IP address, DNS name etc\&.) must be supplied in the array defined by \fIhost_name_list\fR[] which has a count of \fIhost_name_count\fR\&. This is used to check whether the current endpoint is the proxy target address, or the request has to be passed on to an upstream server\&. \fIflags\fR can be zero or more COAP_RESOURCE_FLAGS MCAST definitions\&. .sp \fBFunction: coap_add_resource()\fR .sp The \fBcoap_add_resource\fR() function registers the given \fIresource\fR with the \fIcontext\fR\&. The \fIresource\fR must have been created by \fBcoap_resource_init\fR(), \fBcoap_resource_unknown_init\fR(), \fBcoap_resource_unknown_init2\fR(), \fBcoap_resource_proxy_uri_init\fR() or \fBcoap_resource_proxy_uri_init2\fR()\&. The storage allocated for the \fIresource\fR will be released by \fBcoap_delete_resource\fR()\&. .sp As the \fIuri_path\fR of the resource has to be unique across all of the resources associated with a \fIcontext\fR, \fBcoap_add_resource\fR() will delete any previous \fIresource\fR with the same \fIuri_path\fR before adding in the new \fIresource\fR\&. .sp \fBFunction: coap_delete_resource()\fR .sp The \fBcoap_delete_resource\fR() function deletes the resource identified by \fIresource\fR\&. The \fIcontext\fR parameter is ignored\&. The storage allocated for that \fIresource\fR is freed, along with any attributes associated with the \fIresource\fR\&. .sp \fBFunction: coap_resource_set_mode()\fR .sp The \fBcoap_resource_set_mode\fR() changes the unsolicited notification message type of \fIresource\fR to the given \fImode\fR which must be one of COAP_RESOURCE_FLAGS_NOTIFY_NON, COAP_RESOURCE_FLAGS_NOTIFY_NON_ALWAYS or COAP_RESOURCE_FLAGS_NOTIFY_CON\&. .sp \fBFunction: coap_resource_set_userdata()\fR .sp The \fBcoap_resource_set_userdata\fR() function allows a pointer to user \fIdata\fR to be associated with a \fIresource\fR that can accessed in any callback that includes \fIresource\fR as a parameter\&. .sp \fBNOTE:\fR \fIdata\fR must point to a static, or allocated, block of memory\&. .sp \fBFunction: coap_resource_get_userdata()\fR .sp The \fBcoap_resource_get_userdata\fR() function obtains the user data pointer from the \fIresource\fR that had previously been set up by \fBcoap_resource_set_userdata\fR()\&. .sp \fBFunction: coap_resource_release_userdata_handler()\fR .sp The \fBcoap_resource_release_userdata_handler\fR() function defines the \fIcontext\fR wide \fIcallback\fR handler to call to release the allocated user data that has been added to the resource using \fBcoap_resource_set_userdata\fR() when the resource is deleted\&. \fIcallback\fR can be NULL (which is the default) if nothing needs to be freed off\&. .sp \fBFunction: coap_resource_get_uri_path()\fR .sp The \fBcoap_resource_get_uri_path\fR() function is used to obtain the UriPath of the \fIresource\fR definion\&. .SH "RETURN VALUES" .sp \fBcoap_resource_init\fR(), \fBcoap_resource_unknown_init\fR(), \fBcoap_resource_unknown_init2\fR(), \fBcoap_resource_proxy_uri_init\fR() and \fBcoap_resource_proxy_uri_init2\fR() return a newly created resource or NULL if there is a malloc failure\&. .sp \fBcoap_delete_resource\fR() returns 0 on failure (\fIresource\fR not found), 1 on success\&. .sp \fBcoap_resource_get_userdata\fR() returns the value previously set by the \fBcoap_resource_set_userdata\fR() function or NULL\&. .sp \fBcoap_resource_get_uri_path\fR() returns the uri_path or NULL if there was a failure\&. .SH "EXAMPLES" .sp \fBFixed Resources Set Up\fR .sp .if n \{\ .RS 4 .\} .nf #include #define INDEX "This is an example server using libcoap\en" static void hnd_get_index(coap_resource_t *resource, coap_session_t *session, const coap_pdu_t *request, const coap_string_t *query, coap_pdu_t *response) { unsigned char buf[3]; /* Remove (void) definition if variable is used */ (void)resource; (void)session; (void)request; (void)query; coap_pdu_set_code(response, COAP_RESPONSE_CODE_CONTENT); coap_add_option(response, COAP_OPTION_CONTENT_TYPE, coap_encode_var_safe(buf, sizeof(buf), COAP_MEDIATYPE_TEXT_PLAIN), buf); coap_add_option(response, COAP_OPTION_MAXAGE, coap_encode_var_safe(buf, sizeof(buf), 0x2ffff), buf); coap_add_data(response, strlen(INDEX), (const uint8_t *)INDEX); coap_pdu_set_code(response, COAP_RESPONSE_CODE_CONTENT); } static void hnd_delete_time(coap_resource_t *resource, coap_session_t *session, const coap_pdu_t *request, const coap_string_t *query, coap_pdu_t *response) { /* Remove (void) definition if variable is used */ (void)resource; (void)session; (void)request; (void)query; /* \&.\&. code \&.\&. */ coap_pdu_set_code(response, COAP_RESPONSE_CODE_DELETED); } static void hnd_get_time(coap_resource_t *resource, coap_session_t *session, const coap_pdu_t *request, const coap_string_t *query, coap_pdu_t *response) { /* Remove (void) definition if variable is used */ (void)resource; (void)session; (void)request; (void)query; (void)response; /* \&.\&. code \&.\&. */ coap_pdu_set_code(response, COAP_RESPONSE_CODE_CONTENT); } static void hnd_put_time(coap_resource_t *resource, coap_session_t *session, const coap_pdu_t *request, const coap_string_t *query, coap_pdu_t *response) { /* Remove (void) definition if variable is used */ (void)resource; (void)session; (void)request; (void)query; (void)response; /* \&.\&. code \&.\&. */ coap_pdu_set_code(response, COAP_RESPONSE_CODE_CHANGED); } static void init_resources(coap_context_t *ctx) { coap_resource_t *r; /* Create a resource to return general information */ r = coap_resource_init(NULL, 0); coap_register_request_handler(r, COAP_REQUEST_GET, hnd_get_index); /* Document resource for \*(Aq\&.well\-known/core\*(Aq request */ coap_add_attr(r, coap_make_str_const("ct"), coap_make_str_const("0"), 0); coap_add_attr(r, coap_make_str_const("title"), coap_make_str_const("\e"General Info\e""), 0); coap_add_resource(ctx, r); /* Create a resource to return return or update time */ r = coap_resource_init(coap_make_str_const("time"), COAP_RESOURCE_FLAGS_NOTIFY_CON); coap_resource_set_get_observable(r, 1); coap_register_request_handler(r, COAP_REQUEST_GET, hnd_get_time); coap_register_request_handler(r, COAP_REQUEST_PUT, hnd_put_time); coap_register_request_handler(r, COAP_REQUEST_DELETE, hnd_delete_time); /* Document resource for \*(Aqtime\*(Aq request */ coap_add_attr(r, coap_make_str_const("ct"), coap_make_str_const("0"), 0); coap_add_attr(r, coap_make_str_const("title"), coap_make_str_const("\e"Internal Clock\e""), 0); coap_add_attr(r, coap_make_str_const("rt"), coap_make_str_const("\e"secs\e""), 0); coap_add_attr(r, coap_make_str_const("if"), coap_make_str_const("\e"clock\e""), 0); coap_add_resource(ctx, r); } .fi .if n \{\ .RE .\} .sp \fBDynamic Resources Set Up\fR .sp .if n \{\ .RS 4 .\} .nf #include /* Regular DELETE handler \- used by resources created by the * Unknown Resource PUT handler */ static void hnd_delete(coap_resource_t *resource, coap_session_t *session, const coap_pdu_t *request, const coap_string_t *query, coap_pdu_t *response) { /* Remove (void) definition if variable is used */ (void)session; (void)request; (void)query; (void)response; /* \&.\&. code \&.\&. */ /* Dynamic resource no longer required \- delete it */ coap_delete_resource(NULL, resource); coap_pdu_set_code(response, COAP_RESPONSE_CODE_DELETED); } /* Regular GET handler \- used by resources created by the * Unknown Resource PUT handler */ static void hnd_get(coap_resource_t *resource, coap_session_t *session, const coap_pdu_t *request, const coap_string_t *query, coap_pdu_t *response) { coap_str_const_t *get_uri_path; /* Remove (void) definition if variable is used */ (void)resource; (void)session; (void)request; (void)query; /* * Get the specific resource being requested to determine what the response is * The uri_path string is a const pointer */ get_uri_path = coap_resource_get_uri_path(resource); /* \&.\&. code \&.\&. */ coap_pdu_set_code(response, COAP_RESPONSE_CODE_CONTENT); } /* Regular PUT handler \- used by resources created by the * Unknown Resource PUT handler */ static void hnd_put(coap_resource_t *resource, coap_session_t *session, const coap_pdu_t *request, const coap_string_t *query, coap_pdu_t *response) { /* Remove (void) definition if variable is used */ (void)resource; (void)session; (void)query; coap_string_t *put_uri_path; size_t length; const uint8_t *data; size_t offset; size_t total; int new_resource = 0; /* get the uri_path */ put_uri_path = coap_get_uri_path(request); if (!put_uri_path) { coap_pdu_set_code(response, COAP_RESPONSE_CODE_NOT_FOUND); return; } coap_get_data_large(request, &length, &data, &offset, &total); /* \&.\&. code \&.\&. */ /* Need to do this as coap_get_uri_path() created it */ coap_delete_string(put_uri_path); if (length + offset < total) coap_pdu_set_code(response, COAP_RESPONSE_CODE_CONTINUE); else if (new_resource) coap_pdu_set_code(response, COAP_RESPONSE_CODE_CREATED); else coap_pdu_set_code(response, COAP_RESPONSE_CODE_CHANGED); } static int check_url_fn(coap_string_t *uri_path, uint8_t code) { /* Remove (void) definition if variable is used */ (void)uri_path; (void)code; /* Code to determine whether the uri is valid or not */ return 1; } /* Unknown Resource PUT handler */ static void hnd_put_unknown(coap_resource_t *resource, coap_session_t *session, const coap_pdu_t *request, const coap_string_t *query, coap_pdu_t *response) { /* Remove (void) definition if variable is used */ (void)resource; coap_pdu_code_t req_code = coap_pdu_get_code(request); coap_resource_t *r; coap_string_t *uri_path; /* get the uri_path \- which will get used by coap_resource_init() */ uri_path = coap_get_uri_path(request); if (!uri_path) { coap_pdu_set_code(response, COAP_RESPONSE_CODE_NOT_FOUND); return; } /* Check if new URI Path is valid */ if (!check_url_fn (uri_path, req_code)) { coap_pdu_set_code(response, COAP_RESPONSE_CODE_NOT_FOUND); coap_delete_string(uri_path); return; } /* * Create a resource to handle the new URI * uri_path will get deleted when the resource is removed */ r = coap_resource_init((coap_str_const_t*)uri_path, COAP_RESOURCE_FLAGS_RELEASE_URI | COAP_RESOURCE_FLAGS_NOTIFY_NON); coap_register_request_handler(r, COAP_REQUEST_PUT, hnd_put); coap_register_request_handler(r, COAP_REQUEST_DELETE, hnd_delete); /* We possibly want to Observe the GETs */ coap_resource_set_get_observable(r, 1); coap_register_request_handler(r, COAP_REQUEST_GET, hnd_get); coap_add_resource(coap_session_get_context(session), r); /* Do the PUT for this first call */ hnd_put(r, session, request, query, response); return; } /* Initialize single Unknown Resource PUT handler */ static void init_resources(coap_context_t *ctx) { coap_resource_t *r; /* Create a resource to handle PUTs to unknown URIs */ r = coap_resource_unknown_init2(hnd_put_unknown, 0); /* * Additional handlers can be added \- for example * coap_register_request_handler(r, COAP_REQUEST_POST, hnd_post_unknown); * coap_register_request_handler(r, COAP_REQUEST_GET, hnd_get_unknown); * coap_register_request_handler(r, COAP_REQUEST_DELETE, hnd_delete_unknown); */ coap_add_resource(ctx, r); } .fi .if n \{\ .RE .\} .SH "SEE ALSO" .sp \fBcoap_attribute\fR(3), \fBcoap_context\fR(3), \fBcoap_handler\fR(3) and \fBcoap_observe\fR(3) .SH "FURTHER INFORMATION" .sp See .sp "RFC7252: The Constrained Application Protocol (CoAP)" .sp "RFC3986: Uniform Resource Identifier (URI): Generic Syntax" .sp for further information\&. .SH "BUGS" .sp Please report bugs on the mailing list for libcoap: libcoap\-developers@lists\&.sourceforge\&.net or raise an issue on GitHub at https://github\&.com/obgm/libcoap/issues .SH "AUTHORS" .sp The libcoap project