net: websocket: client: Simple API for Websocket client

Implement simple API to do Websocket client requests.

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

include/net/websocket.h

@@ -0,0 +1,197 @@
+/** @file
+ * @brief Websocket API
+ *
+ * An API for applications to setup websocket connections
+ */
+
+/*
+ * Copyright (c) 2019 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_NET_WEBSOCKET_H_
+#define ZEPHYR_INCLUDE_NET_WEBSOCKET_H_
+
+#include <kernel.h>
+
+#include <net/net_ip.h>
+#include <net/http_parser.h>
+#include <net/http_client.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Websocket API
+ * @defgroup websocket Websocket API
+ * @ingroup networking
+ * @{
+ */
+
+/** Message type values. Returned in websocket_recv_msg() */
+#define WEBSOCKET_FLAG_FINAL  0x00000001 /**< Final frame        */
+#define WEBSOCKET_FLAG_TEXT   0x00000002 /**< Textual data       */
+#define WEBSOCKET_FLAG_BINARY 0x00000004 /**< Binary data        */
+#define WEBSOCKET_FLAG_CLOSE  0x00000008 /**< Closing connection */
+#define WEBSOCKET_FLAG_PING   0x00000010 /**< Ping message       */
+#define WEBSOCKET_FLAG_PONG   0x00000011 /**< Pong message       */
+
+enum websocket_opcode  {
+	WEBSOCKET_OPCODE_CONTINUE     = 0x00,
+	WEBSOCKET_OPCODE_DATA_TEXT    = 0x01,
+	WEBSOCKET_OPCODE_DATA_BINARY  = 0x02,
+	WEBSOCKET_OPCODE_CLOSE        = 0x08,
+	WEBSOCKET_OPCODE_PING         = 0x09,
+	WEBSOCKET_OPCODE_PONG         = 0x0A,
+};
+
+/**
+ * @typedef websocket_connect_cb_t
+ * @brief Callback called after Websocket connection is established.
+ *
+ * @param sock Websocket id
+ * @param req HTTP handshake request
+ * @param user_data A valid pointer on some user data or NULL
+ *
+ * @return 0 if ok, <0 if there is an error and connection should be aborted
+ */
+typedef int (*websocket_connect_cb_t)(int ws_sock, struct http_request *req,
+				      void *user_data);
+
+/**
+ * Websocket client connection request. This contains all the data that is
+ * needed when doing a Websocket connection request.
+ */
+struct websocket_request {
+	/** Host of the Websocket server when doing HTTP handshakes. */
+	const char *host;
+
+	/** URL of the Websocket. */
+	const char *url;
+
+	/** User supplied callback function to call when optional headers need
+	 * to be sent. This can be NULL, in which case the optional_headers
+	 * field in http_request is used. The idea of this optional_headers
+	 * callback is to allow user to send more HTTP header data that is
+	 * practical to store in allocated memory.
+	 */
+	http_header_cb_t optional_headers_cb;
+
+	/** A NULL terminated list of any optional headers that
+	 * should be added to the HTTP request. May be NULL.
+	 * If the optional_headers_cb is specified, then this field is ignored.
+	 */
+	const char **optional_headers;
+
+	/** User supplied callback function to call when a connection is
+	 * established.
+	 */
+	websocket_connect_cb_t cb;
+
+	/** User supplied list of callback functions if the calling application
+	 * wants to know the parsing status or the HTTP fields during the
+	 * handshake. This is optional parameter and normally not needed but
+	 * is useful if the caller wants to know something about
+	 * the fields that the server is sending.
+	 */
+	const struct http_parser_settings *http_cb;
+
+	/** User supplied buffer where HTTP connection data is stored */
+	u8_t *tmp_buf;
+
+	/** Length of the user supplied temp buffer */
+	size_t tmp_buf_len;
+};
+
+/**
+ * @brief Connect to a server that provides Websocket service. The callback is
+ * called after connection is established. The returned value is a new socket
+ * descriptor that can be used to send / receive data using the BSD socket API.
+ *
+ * @param http_sock Socket id to the server. Note that this socket is used to do
+ *        HTTP handshakes etc. The actual Websocket connectivity is done via the
+ *        returned websocket id. Note that the http_sock must not be closed
+ *        after this function returns as it is used to deliver the Websocket
+ *        packets to the Websocket server.
+ * @param req Websocket request. User should allocate and fill the request
+ *        data.
+ * @param timeout Max timeout to wait for the connection. The timeout value
+ *        cannot be 0 as there would be no time to receive the data.
+ * @param user_data User specified data that is passed to the callback.
+ *
+ * @return Websocket id to be used when sending/receiving Websocket data.
+ */
+int websocket_connect(int http_sock, struct websocket_request *req,
+		      s32_t timeout, void *user_data);
+
+/**
+ * @brief Send websocket msg to peer.
+ *
+ * @details The function will automatically add websocket header to the
+ * message.
+ *
+ * @param ws_sock Websocket id returned by websocket_connect().
+ * @param payload Websocket data to send.
+ * @param payload_len Length of the data to be sent.
+ * @param opcode Operation code (text, binary, ping, pong, close)
+ * @param mask Mask the data, see RFC 6455 for details
+ * @param final Is this final message for this message send. If final == false,
+ *        then the first message must have valid opcode and subsequent messages
+ *        must have opcode WEBSOCKET_OPCODE_CONTINUE. If final == true and this
+ *        is the only message, then opcode should have proper opcode (text or
+ *        binary) set.
+ * @param timeout How long to try to send the message.
+ *
+ * @return <0 if error, >=0 amount of bytes sent
+ */
+int websocket_send_msg(int ws_sock, const u8_t *payload, size_t payload_len,
+		       enum websocket_opcode opcode, bool mask, bool final,
+		       s32_t timeout);
+
+/**
+ * @brief Receive websocket msg from peer.
+ *
+ * @details The function will automatically remove websocket header from the
+ * message.
+ *
+ * @param ws_sock Websocket id returned by websocket_connect().
+ * @param buf Buffer where websocket data is read.
+ * @param buf_len Length of the data buffer.
+ * @param message_type Type of the message.
+ * @param remaining How much there is data left in the message after this read.
+ * @param timeout How long to try to receive the message.
+ *
+ * @return <0 if error, >=0 amount of bytes received
+ */
+int websocket_recv_msg(int ws_sock, u8_t *buf, size_t buf_len,
+		       u32_t *message_type, u64_t *remaining, s32_t timeout);
+
+/**
+ * @brief Close websocket.
+ *
+ * @details One must call websocket_connect() after this call to re-establish
+ * the connection.
+ *
+ * @param ws_sock Websocket id returned by websocket_connect().
+ */
+int websocket_disconnect(int ws_sock);
+
+#if defined(CONFIG_WEBSOCKET_CLIENT)
+void websocket_init(void);
+#else
+static inline void websocket_init(void)
+{
+}
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+/**
+ * @}
+ */
+
+#endif /* ZEPHYR_INCLUDE_NET_WEBSOCKET_H_ */