net: lib: coap: Add resources length based variants

Add length variant for the well known core resource and parsing.

Signed-off-by: Pieter De Gendt <pieter.degendt@basalte.be>

include/zephyr/net/coap.h

@@ -583,12 +583,36 @@ int coap_packet_append_payload(struct coap_packet *cpkt, const uint8_t *payload,
  *
  * @param cpkt Packet received
  * @param resources Array of known resources
+ * @param resources_len Number of resources in the array
  * @param options Parsed options from coap_packet_parse()
  * @param opt_num Number of options
  * @param addr Peer address
  * @param addr_len Peer address length
  *
- * @retval 0 in case of success.
+ * @retval >= 0 in case of success.
+ * @retval -ENOTSUP in case of invalid request code.
+ * @retval -EPERM in case resource handler is not implemented.
+ * @retval -ENOENT in case the resource is not found.
+ */
+int coap_handle_request_len(struct coap_packet *cpkt,
+			    struct coap_resource *resources,
+			    size_t resources_len,
+			    struct coap_option *options,
+			    uint8_t opt_num,
+			    struct sockaddr *addr, socklen_t addr_len);
+
+/**
+ * @brief When a request is received, call the appropriate methods of
+ * the matching resources.
+ *
+ * @param cpkt Packet received
+ * @param resources Array of known resources (terminated with empty resource)
+ * @param options Parsed options from coap_packet_parse()
+ * @param opt_num Number of options
+ * @param addr Peer address
+ * @param addr_len Peer address length
+ *
+ * @retval >= 0 in case of success.
  * @retval -ENOTSUP in case of invalid request code.
  * @retval -EPERM in case resource handler is not implemented.
  * @retval -ENOENT in case the resource is not found.

include/zephyr/net/coap_link_format.h

@@ -24,15 +24,45 @@ extern "C" {
 
 /**
  * This resource should be added before all other resources that should be
- * included in the responses of the .well-known/core resource.
+ * included in the responses of the .well-known/core resource if is to be used with
+ * coap_well_known_core_get.
  */
 #define COAP_WELL_KNOWN_CORE_PATH \
 	((const char * const[]) { ".well-known", "core", NULL })
 
+/**
+ * @brief Build a CoAP response for a .well-known/core CoAP request.
+ *
+ * @param resource Array of known resources, terminated with an empty resource
+ * @param request A pointer to the .well-known/core CoAP request
+ * @param response A pointer to a CoAP response, will be initialized
+ * @param data A data pointer to be used to build the CoAP response
+ * @param data_len The maximum length of the data buffer
+ *
+ * @return 0 in case of success or negative in case of error.
+ */
 int coap_well_known_core_get(struct coap_resource *resource,
-			     struct coap_packet *request,
+			     const struct coap_packet *request,
 			     struct coap_packet *response,
-			     uint8_t *data, uint16_t len);
+			     uint8_t *data, uint16_t data_len);
+
+/**
+ * @brief Build a CoAP response for a .well-known/core CoAP request.
+ *
+ * @param resources Array of known resources
+ * @param resources_len Number of resources in the array
+ * @param request A pointer to the .well-known/core CoAP request
+ * @param response A pointer to a CoAP response, will be initialized
+ * @param data A data pointer to be used to build the CoAP response
+ * @param data_len The maximum length of the data buffer
+ *
+ * @return 0 in case of success or negative in case of error.
+ */
+int coap_well_known_core_get_len(struct coap_resource *resources,
+				 size_t resources_len,
+				 const struct coap_packet *request,
+				 struct coap_packet *response,
+				 uint8_t *data, uint16_t data_len);
 
 /**
  * In case you want to add attributes to the resources included in the

subsys/net/lib/coap/coap.c

@@ -1147,29 +1147,28 @@ static bool is_request(const struct coap_packet *cpkt)
 	return !(code & ~COAP_REQUEST_MASK);
 }
 
-int coap_handle_request(struct coap_packet *cpkt,
+int coap_handle_request_len(struct coap_packet *cpkt,
-			struct coap_resource *resources,
+			    struct coap_resource *resources,
-			struct coap_option *options,
+			    size_t resources_len,
-			uint8_t opt_num,
+			    struct coap_option *options,
-			struct sockaddr *addr, socklen_t addr_len)
+			    uint8_t opt_num,
+			    struct sockaddr *addr, socklen_t addr_len)
 {
-	struct coap_resource *resource;
-
 	if (!is_request(cpkt)) {
 		return 0;
 	}
 
 	/* FIXME: deal with hierarchical resources */
-	for (resource = resources; resource && resource->path; resource++) {
+	for (size_t i = 0; i < resources_len; i++) {
 		coap_method_t method;
 		uint8_t code;
 
-		if (!uri_path_eq(cpkt, resource->path, options, opt_num)) {
+		if (!uri_path_eq(cpkt, resources[i].path, options, opt_num)) {
 			continue;
 		}
 
 		code = coap_header_get_code(cpkt);
-		if (method_from_code(resource, code, &method) < 0) {
+		if (method_from_code(&resources[i], code, &method) < 0) {
 			return -ENOTSUP;
 		}
 
@@ -1177,13 +1176,29 @@ int coap_handle_request(struct coap_packet *cpkt,
 			return -EPERM;
 		}
 
-		return method(resource, cpkt, addr, addr_len);
+		return method(&resources[i], cpkt, addr, addr_len);
 	}
 
-	NET_DBG("%d", __LINE__);
 	return -ENOENT;
 }
 
+int coap_handle_request(struct coap_packet *cpkt,
+			struct coap_resource *resources,
+			struct coap_option *options,
+			uint8_t opt_num,
+			struct sockaddr *addr, socklen_t addr_len)
+{
+	size_t resources_len = 0;
+	struct coap_resource *resource;
+
+	for (resource = resources; resource && resource->path; resource++) {
+		resources_len++;
+	}
+
+	return coap_handle_request_len(cpkt, resources, resources_len, options, opt_num, addr,
+				       addr_len);
+}
+
 int coap_block_transfer_init(struct coap_block_context *ctx,
 			      enum coap_block_size block_size,
 			      size_t total_size)

subsys/net/lib/coap/coap_link_format.c

@@ -432,10 +432,11 @@ int clear_more_flag(struct coap_packet *cpkt)
 	return 0;
 }
 
-int coap_well_known_core_get(struct coap_resource *resource,
+int coap_well_known_core_get_len(struct coap_resource *resources,
-			      struct coap_packet *request,
+				 size_t resources_len,
-			      struct coap_packet *response,
+				 struct coap_packet *request,
-			      uint8_t *data, uint16_t len)
+				 struct coap_packet *response,
+				 uint8_t *data, uint16_t len)
 {
 	static struct coap_block_context ctx;
 	struct coap_option query;
@@ -446,9 +447,9 @@ int coap_well_known_core_get(struct coap_resource *resource,
 	uint16_t id;
 	uint8_t tkl;
 	int r;
-	bool more = false;
+	bool more = false, first = true;
 
-	if (!resource || !request || !response || !data || !len) {
+	if (!resources || !request || !response || !data || !len) {
 		return -EINVAL;
 	}
 
@@ -505,29 +506,31 @@ int coap_well_known_core_get(struct coap_resource *resource,
 	offset = 0;
 	remaining = coap_block_size_to_bytes(ctx.block_size);
 
-	while (resource++ && resource->path) {
+	for (size_t i = 0; i < resources_len; ++i) {
 		if (!remaining) {
 			more = true;
 			break;
 		}
 
-		if (!match_queries_resource(resource, &query, num_queries)) {
+		if (!match_queries_resource(&resources[i], &query, num_queries)) {
 			continue;
 		}
 
-		r = format_resource(resource, response, &remaining, &offset,
+		if (first) {
-				    ctx.current, &more);
+			first = false;
-		if (r < 0) {
+		} else {
-			goto end;
-		}
-
-		if ((resource + 1) && (resource + 1)->path) {
 			r = append_to_coap_pkt(response, ",", 1, &remaining,
 					       &offset, ctx.current);
 			if (!r) {
 				goto end;
 			}
 		}
+
+		r = format_resource(&resources[i], response, &remaining, &offset,
+				    ctx.current, &more);
+		if (r < 0) {
+			goto end;
+		}
 	}
 
 	/* Offset is the total size now, but block2 option is already
@@ -631,10 +634,11 @@ static int format_resource(const struct coap_resource *resource,
 	return format_attributes(attributes, response);
 }
 
-int coap_well_known_core_get(struct coap_resource *resource,
+int coap_well_known_core_get_len(struct coap_resource *resources,
-			     struct coap_packet *request,
+				 size_t resources_len,
-			     struct coap_packet *response,
+				 const struct coap_packet *request,
-			     uint8_t *data, uint16_t len)
+				 struct coap_packet *response,
+				 uint8_t *data, uint16_t data_len)
 {
 	struct coap_option query;
 	uint8_t token[COAP_TOKEN_MAX_LEN];
@@ -642,8 +646,9 @@ int coap_well_known_core_get(struct coap_resource *resource,
 	uint8_t tkl;
 	uint8_t num_queries;
 	int r;
+	bool first = true;
 
-	if (!resource || !request || !response || !data || !len) {
+	if (!resources || !request || !response || !data || !data_len) {
 		return -EINVAL;
 	}
 
@@ -660,7 +665,7 @@ int coap_well_known_core_get(struct coap_resource *resource,
 
 	num_queries = r;
 
-	r = coap_packet_init(response, data, len, COAP_VERSION_1, COAP_TYPE_ACK,
+	r = coap_packet_init(response, data, data_len, COAP_VERSION_1, COAP_TYPE_ACK,
 			     tkl, token, COAP_RESPONSE_CODE_CONTENT, id);
 	if (r < 0) {
 		return r;
@@ -677,28 +682,50 @@ int coap_well_known_core_get(struct coap_resource *resource,
 		return -EINVAL;
 	}
 
-	while (resource++ && resource->path) {
+	for (size_t i = 0; i < resources_len; ++i) {
-		if (!match_queries_resource(resource, &query, num_queries)) {
+		if (!match_queries_resource(&resources[i], &query, num_queries)) {
 			continue;
 		}
 
-		r = format_resource(resource, response);
+		if (first) {
-		if (r < 0) {
+			first = false;
-			return r;
+		} else {
-		}
-
-		if ((resource + 1)->path) {
 			r = append_u8(response, (uint8_t) ',');
 			if (!r) {
 				return -ENOMEM;
 			}
 		}
+
+		r = format_resource(&resources[i], response);
+		if (r < 0) {
+			return r;
+		}
 	}
 
 	return 0;
 }
 #endif
 
+int coap_well_known_core_get(struct coap_resource *resource,
+			     const struct coap_packet *request,
+			     struct coap_packet *response,
+			     uint8_t *data, uint16_t data_len)
+{
+	struct coap_resource *resources = resource + 1;
+	size_t resources_len = 0;
+
+	if (resource == NULL) {
+		return -EINVAL;
+	}
+
+	while (resources[resources_len].path) {
+		resources_len++;
+	}
+
+	return coap_well_known_core_get_len(resources, resources_len, request, response, data,
+					    data_len);
+}
+
 /* Exposing some of the APIs to CoAP unit tests in tests/net/lib/coap */
 #if defined(CONFIG_COAP_TEST_API_ENABLE)
 bool _coap_match_path_uri(const char * const *path,