net: lib: http_server: remove dynamic resource data buffer

After introduction of struct http_response_ctx, the dynamic resource
data buffer is no longer needed for transferring data between the
application callback and the server. It is therefore removed to avoid
unnecessary copying of data.

Signed-off-by: Matt Rodgers <[email protected]>

Author: mrodgers-witekio

include/zephyr/net/http/server.h

@@ -214,14 +214,6 @@ struct http_resource_detail_dynamic {
 	 */
 	http_resource_dynamic_cb_t cb;
 
-	/** Data buffer used to exchanged data between server and the,
-	 *  application.
-	 */
-	uint8_t *data_buffer;
-
-	/** Length of the data in the data buffer. */
-	size_t data_buffer_len;
-
 	/** A pointer to the client currently processing resource, used to
 	 *  prevent concurrent access to the resource from multiple clients.
 	 */

samples/net/sockets/http_server/src/main.c

@@ -45,10 +45,6 @@ static uint8_t main_js_gz[] = {
 #include "main.js.gz.inc"
 };
 
-static uint8_t uptime_buf[256];
-static uint8_t led_buf[256];
-static uint8_t echo_buf[1024];
-
 static struct http_resource_detail_static index_html_gz_resource_detail = {
 	.common = {
 			.type = HTTP_RESOURCE_TYPE_STATIC,
@@ -113,8 +109,6 @@ static struct http_resource_detail_dynamic echo_resource_detail = {
 			.bitmask_of_supported_http_methods = BIT(HTTP_GET) | BIT(HTTP_POST),
 		},
 	.cb = echo_handler,
-	.data_buffer = echo_buf,
-	.data_buffer_len = sizeof(echo_buf),
 	.user_data = NULL,
 };
 
@@ -151,8 +145,6 @@ static struct http_resource_detail_dynamic uptime_resource_detail = {
 			.bitmask_of_supported_http_methods = BIT(HTTP_GET),
 		},
 	.cb = uptime_handler,
-	.data_buffer = uptime_buf,
-	.data_buffer_len = sizeof(uptime_buf),
 	.user_data = NULL,
 };
 
@@ -219,8 +211,6 @@ static struct http_resource_detail_dynamic led_resource_detail = {
 			.bitmask_of_supported_http_methods = BIT(HTTP_POST),
 		},
 	.cb = led_handler,
-	.data_buffer = led_buf,
-	.data_buffer_len = sizeof(led_buf),
 	.user_data = NULL,
 };
 

subsys/net/lib/http/http_server_http1.c

@@ -257,33 +257,21 @@ static int http1_dynamic_response(struct http_client_ctx *client, struct http_re
 static int dynamic_get_req(struct http_resource_detail_dynamic *dynamic_detail,
 			   struct http_client_ctx *client)
 {
-	/* offset tells from where the GET params start */
-	int ret, remaining, offset = dynamic_detail->common.path_len;
+	int ret, len;
 	char *ptr;
+	enum http_data_status status;
+	struct http_response_ctx response_ctx;
 
-	remaining = strlen(&client->url_buffer[dynamic_detail->common.path_len]);
-
-	/* Pass URL to the client */
-	while (1) {
-		int copy_len;
-		enum http_data_status status;
-		struct http_response_ctx response_ctx;
-
-		ptr = &client->url_buffer[offset];
-		copy_len = MIN(remaining, dynamic_detail->data_buffer_len);
-
-		memcpy(dynamic_detail->data_buffer, ptr, copy_len);
-
-		if (copy_len == remaining) {
-			status = HTTP_SERVER_DATA_FINAL;
-		} else {
-			status = HTTP_SERVER_DATA_MORE;
-		}
+	/* Start of GET params */
+	ptr = &client->url_buffer[dynamic_detail->common.path_len];
+	len = strlen(ptr);
+	status = HTTP_SERVER_DATA_FINAL;
 
+	do {
 		memset(&response_ctx, 0, sizeof(response_ctx));
 
-		ret = dynamic_detail->cb(client, status, dynamic_detail->data_buffer, copy_len,
-					 &response_ctx, dynamic_detail->user_data);
+		ret = dynamic_detail->cb(client, status, ptr, len, &response_ctx,
+					 dynamic_detail->user_data);
 		if (ret < 0) {
 			return ret;
 		}
@@ -293,13 +281,9 @@ static int dynamic_get_req(struct http_resource_detail_dynamic *dynamic_detail,
 			return ret;
 		}
 
-		if (http_response_is_final(&response_ctx, status)) {
-			break;
-		}
-
-		offset += copy_len;
-		remaining -= copy_len;
-	}
+		/* URL params are passed in the first cb only */
+		len = 0;
+	} while (!http_response_is_final(&response_ctx, status));
 
 	dynamic_detail->holder = NULL;
 
@@ -315,67 +299,66 @@ static int dynamic_get_req(struct http_resource_detail_dynamic *dynamic_detail,
 static int dynamic_post_req(struct http_resource_detail_dynamic *dynamic_detail,
 			    struct http_client_ctx *client)
 {
-	/* offset tells from where the POST params start */
+	int ret;
+	char *ptr = client->cursor;
+	enum http_data_status status;
 	struct http_response_ctx response_ctx;
-	char *start = client->cursor;
-	int ret, remaining = client->data_len, offset = 0;
-	int copy_len;
-	char *ptr;
 
-	if (start == NULL) {
+	if (ptr == NULL) {
 		return -ENOENT;
 	}
 
-	copy_len = MIN(remaining, dynamic_detail->data_buffer_len);
-	while (1) {
-		enum http_data_status status;
+	if (client->parser_state == HTTP1_MESSAGE_COMPLETE_STATE) {
+		status = HTTP_SERVER_DATA_FINAL;
+	} else {
+		status = HTTP_SERVER_DATA_MORE;
+	}
 
-		ptr = &start[offset];
+	memset(&response_ctx, 0, sizeof(response_ctx));
 
-		memcpy(dynamic_detail->data_buffer, ptr, copy_len);
+	ret = dynamic_detail->cb(client, status, ptr, client->data_len, &response_ctx,
+				 dynamic_detail->user_data);
+	if (ret < 0) {
+		return ret;
+	}
 
-		if (copy_len == remaining &&
-		    client->parser_state == HTTP1_MESSAGE_COMPLETE_STATE) {
-			status = HTTP_SERVER_DATA_FINAL;
-		} else {
-			status = HTTP_SERVER_DATA_MORE;
+	/* For POST the application might not send a response until all data has been received.
+	 * Don't send a default response until the application has had a chance to respond.
+	 */
+	if (http_response_is_provided(&response_ctx)) {
+		ret = http1_dynamic_response(client, &response_ctx, dynamic_detail);
+		if (ret < 0) {
+			return ret;
 		}
+	}
 
+	/* Once all data is transferred to application, repeat cb until response is complete */
+	while (!http_response_is_final(&response_ctx, status) && status == HTTP_SERVER_DATA_FINAL) {
 		memset(&response_ctx, 0, sizeof(response_ctx));
 
-		ret = dynamic_detail->cb(client, status, dynamic_detail->data_buffer, copy_len,
-					 &response_ctx, dynamic_detail->user_data);
+		ret = dynamic_detail->cb(client, status, ptr, 0, &response_ctx,
+					 dynamic_detail->user_data);
 		if (ret < 0) {
 			return ret;
 		}
 
-		if (http_response_is_provided(&response_ctx)) {
-			ret = http1_dynamic_response(client, &response_ctx, dynamic_detail);
-			if (ret < 0) {
-				return ret;
-			}
-		}
-
-		if (http_response_is_final(&response_ctx, status)) {
-			break;
-		}
-
-		offset += copy_len;
-		remaining -= copy_len;
-		copy_len = MIN(remaining, dynamic_detail->data_buffer_len);
-	}
-
-	/* Ensure headers are sent if not done already */
-	if (!client->http1_headers_sent) {
-		memset(&response_ctx, 0, sizeof(response_ctx));
-		response_ctx.final_chunk = true;
 		ret = http1_dynamic_response(client, &response_ctx, dynamic_detail);
 		if (ret < 0) {
 			return ret;
 		}
 	}
 
+	/* At end of message, ensure response is sent and terminated */
 	if (client->parser_state == HTTP1_MESSAGE_COMPLETE_STATE) {
+		if (!client->http1_headers_sent) {
+			memset(&response_ctx, 0, sizeof(response_ctx));
+			response_ctx.final_chunk = true;
+			ret = http1_dynamic_response(client, &response_ctx, dynamic_detail);
+			if (ret < 0) {
+				return ret;
+			}
+		}
+
 		ret = http_server_sendall(client, final_chunk,
 					sizeof(final_chunk) - 1);
 		if (ret < 0) {