net: mqtt: Add support for running MQTT over Websocket

Initial support for running MQTT over Websocket.

Fixes #19539

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

include/net/mqtt.h

@@ -29,6 +29,7 @@
 #include <net/tls_credentials.h>
 #include <net/net_ip.h>
 #include <sys/mutex.h>
+#include <net/websocket.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -350,6 +351,15 @@ enum mqtt_transport_type {
 	MQTT_TRANSPORT_SECURE,
 #endif /* CONFIG_MQTT_LIB_TLS */
 
+#if defined(CONFIG_MQTT_LIB_WEBSOCKET)
+	/** Use non secure Websocket transport for MQTT connection. */
+	MQTT_TRANSPORT_NON_SECURE_WEBSOCKET,
+#if defined(CONFIG_MQTT_LIB_TLS)
+	/** Use secure Websocket transport (TLS) for MQTT connection. */
+	MQTT_TRANSPORT_SECURE_WEBSOCKET,
+#endif
+#endif /* CONFIG_MQTT_LIB_WEBSOCKET */
+
 	/** Shall not be used as a transport type.
 	 *  Indicator of maximum transport types possible.
 	 */
@@ -385,6 +395,20 @@ struct mqtt_transport {
 #endif /* CONFIG_MQTT_LIB_TLS */
 	};
 
+#if defined(CONFIG_MQTT_LIB_WEBSOCKET)
+	/** Websocket transport for MQTT */
+	struct {
+		/** Websocket configuration. */
+		struct websocket_request config;
+
+		/** Socket descriptor */
+		int sock;
+
+		/** Websocket timeout */
+		s32_t timeout;
+	} websocket;
+#endif
+
 #if defined(CONFIG_SOCKS)
 	struct {
 		struct sockaddr addr;

subsys/net/lib/mqtt/CMakeLists.txt

@@ -14,3 +14,7 @@ zephyr_library_sources(
 zephyr_library_sources_ifdef(CONFIG_MQTT_LIB_TLS
   mqtt_transport_socket_tls.c
   )
+
+zephyr_library_sources_ifdef(CONFIG_MQTT_LIB_WEBSOCKET
+  mqtt_transport_websocket.c
+  )

subsys/net/lib/mqtt/Kconfig

@@ -32,4 +32,9 @@ config MQTT_LIB_TLS
 	help
 	  Enable TLS support for socket MQTT Library
 
+config MQTT_LIB_WEBSOCKET
+	bool "Websocket support for socket MQTT Library"
+	help
+	  Enable Websocket support for socket MQTT Library.
+
 endif # MQTT_LIB

subsys/net/lib/mqtt/mqtt_transport.c

@@ -11,24 +11,6 @@
 
 #include "mqtt_transport.h"
 
-/* Transport handler functions for TCP socket transport. */
-extern int mqtt_client_tcp_connect(struct mqtt_client *client);
-extern int mqtt_client_tcp_write(struct mqtt_client *client, const u8_t *data,
-				 u32_t datalen);
-extern int mqtt_client_tcp_read(struct mqtt_client *client, u8_t *data,
-				u32_t buflen, bool shall_block);
-extern int mqtt_client_tcp_disconnect(struct mqtt_client *client);
-
-#if defined(CONFIG_MQTT_LIB_TLS)
-/* Transport handler functions for TLS socket transport. */
-extern int mqtt_client_tls_connect(struct mqtt_client *client);
-extern int mqtt_client_tls_write(struct mqtt_client *client, const u8_t *data,
-				 u32_t datalen);
-extern int mqtt_client_tls_read(struct mqtt_client *client, u8_t *data,
-				u32_t buflen, bool shall_block);
-extern int mqtt_client_tls_disconnect(struct mqtt_client *client);
-#endif /* CONFIG_MQTT_LIB_TLS */
-
 /**@brief Function pointer array for TCP/TLS transport handlers. */
 const struct transport_procedure transport_fn[MQTT_TRANSPORT_NUM] = {
 	{
@@ -45,6 +27,22 @@ const struct transport_procedure transport_fn[MQTT_TRANSPORT_NUM] = {
 		mqtt_client_tls_disconnect,
 	},
 #endif /* CONFIG_MQTT_LIB_TLS */
+#if defined(CONFIG_MQTT_LIB_WEBSOCKET)
+	{
+		mqtt_client_websocket_connect,
+		mqtt_client_websocket_write,
+		mqtt_client_websocket_read,
+		mqtt_client_websocket_disconnect,
+	},
+#if defined(CONFIG_MQTT_LIB_TLS)
+	{
+		mqtt_client_websocket_connect,
+		mqtt_client_websocket_write,
+		mqtt_client_websocket_read,
+		mqtt_client_websocket_disconnect,
+	},
+#endif /* CONFIG_MQTT_LIB_TLS */
+#endif /* CONFIG_MQTT_LIB_WEBSOCKET */
 };
 
 int mqtt_transport_connect(struct mqtt_client *client)

subsys/net/lib/mqtt/mqtt_transport.h

@@ -95,6 +95,33 @@ int mqtt_transport_read(struct mqtt_client *client, u8_t *data, u32_t buflen,
  */
 int mqtt_transport_disconnect(struct mqtt_client *client);
 
+/* Transport handler functions for TCP socket transport. */
+int mqtt_client_tcp_connect(struct mqtt_client *client);
+int mqtt_client_tcp_write(struct mqtt_client *client, const u8_t *data,
+			  u32_t datalen);
+int mqtt_client_tcp_read(struct mqtt_client *client, u8_t *data,
+			 u32_t buflen, bool shall_block);
+int mqtt_client_tcp_disconnect(struct mqtt_client *client);
+
+#if defined(CONFIG_MQTT_LIB_TLS)
+/* Transport handler functions for TLS socket transport. */
+int mqtt_client_tls_connect(struct mqtt_client *client);
+int mqtt_client_tls_write(struct mqtt_client *client, const u8_t *data,
+			  u32_t datalen);
+int mqtt_client_tls_read(struct mqtt_client *client, u8_t *data,
+			 u32_t buflen, bool shall_block);
+int mqtt_client_tls_disconnect(struct mqtt_client *client);
+#endif /* CONFIG_MQTT_LIB_TLS */
+
+#if defined(CONFIG_MQTT_LIB_WEBSOCKET)
+int mqtt_client_websocket_connect(struct mqtt_client *client);
+int mqtt_client_websocket_write(struct mqtt_client *client, const u8_t *data,
+				u32_t datalen);
+int mqtt_client_websocket_read(struct mqtt_client *client, u8_t *data,
+			       u32_t buflen, bool shall_block);
+int mqtt_client_websocket_disconnect(struct mqtt_client *client);
+#endif
+
 #ifdef __cplusplus
 }
 #endif

subsys/net/lib/mqtt/mqtt_transport_websocket.c

@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2018 Nordic Semiconductor ASA
+ * Copyright (c) 2019 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/** @file mqtt_transport_websocket.c
+ *
+ * @brief Internal functions to handle transport over Websocket.
+ */
+
+#include <logging/log.h>
+LOG_MODULE_REGISTER(net_mqtt_websocket, CONFIG_MQTT_LOG_LEVEL);
+
+#include <errno.h>
+#include <net/socket.h>
+#include <net/mqtt.h>
+#include <net/websocket.h>
+
+#include "mqtt_os.h"
+#include "mqtt_transport.h"
+
+int mqtt_client_websocket_connect(struct mqtt_client *client)
+{
+	const char *extra_headers[] = {
+		"Sec-WebSocket-Protocol: mqtt\r\n",
+		NULL
+	};
+	int transport_sock;
+	int ret;
+
+	if (client->transport.type == MQTT_TRANSPORT_NON_SECURE_WEBSOCKET) {
+		ret = mqtt_client_tcp_connect(client);
+		if (ret < 0) {
+			return ret;
+		}
+
+		transport_sock = client->transport.tcp.sock;
+	}
+#if defined(CONFIG_MQTT_LIB_TLS)
+	else if (client->transport.type == MQTT_TRANSPORT_SECURE_WEBSOCKET) {
+		ret = mqtt_client_tls_connect(client);
+		if (ret < 0) {
+			return ret;
+		}
+
+		transport_sock = client->transport.tls.sock;
+	}
+#endif
+	else {
+		return -EINVAL;
+	}
+
+	if (client->transport.websocket.config.url == NULL) {
+		client->transport.websocket.config.url = "/mqtt";
+	}
+
+	if (client->transport.websocket.config.host == NULL) {
+		client->transport.websocket.config.host = "localhost";
+	}
+
+	/* If application needs to set some extra header options, then
+	 * it can set the optional_headers_cb. In this case the app
+	 * will need to also send "Sec-WebSocket-Protocol: mqtt\r\n"
+	 * field as the optional_headers field is ignored if the callback
+	 * is set.
+	 */
+	client->transport.websocket.config.optional_headers = extra_headers;
+
+	client->transport.websocket.sock = websocket_connect(
+			transport_sock,
+			&client->transport.websocket.config,
+			client->transport.websocket.timeout,
+			NULL);
+	if (client->transport.websocket.sock < 0) {
+		MQTT_TRC("Websocket connect failed (%d)",
+			 client->transport.websocket.sock);
+
+		(void)close(transport_sock);
+		return client->transport.websocket.sock;
+	}
+
+	MQTT_TRC("Connect completed");
+
+	return 0;
+}
+
+int mqtt_client_websocket_write(struct mqtt_client *client, const u8_t *data,
+				u32_t datalen)
+{
+	u32_t offset = 0U;
+	int ret;
+
+	while (offset < datalen) {
+		ret = websocket_send_msg(client->transport.websocket.sock,
+					 data + offset, datalen - offset,
+					 WEBSOCKET_OPCODE_DATA_BINARY,
+					 true, true, K_FOREVER);
+		if (ret < 0) {
+			return -errno;
+		}
+
+		offset += ret;
+	}
+
+	return 0;
+}
+
+int mqtt_client_websocket_read(struct mqtt_client *client, u8_t *data,
+			       u32_t buflen, bool shall_block)
+{
+	s32_t timeout = K_FOREVER;
+
+	if (!shall_block) {
+		timeout = K_NO_WAIT;
+	}
+
+	return websocket_recv_msg(client->transport.websocket.sock,
+				  data, buflen, NULL, NULL, timeout);
+}
+
+int mqtt_client_websocket_disconnect(struct mqtt_client *client)
+{
+	MQTT_TRC("Closing socket %d", client->transport.websocket.sock);
+
+	return websocket_disconnect(client->transport.websocket.sock);
+}