qemu/include/io/channel-websock.h
Daniel P. Berrange 8dfd5f9651 io: get rid of bounce buffering in websock write path
Currently most outbound I/O on the websock channel gets copied into the
rawoutput buffer, and then immediately copied again into the encoutput
buffer, with a header prepended. Now that qio_channel_websock_encode
accepts a struct iovec, we can trivially remove this bounce buffering
and write directly to encoutput.

In doing so, we also now correctly validate the encoutput size against
the QIO_CHANNEL_WEBSOCK_MAX_BUFFER limit.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00

110 lines
3.4 KiB
C

/*
* QEMU I/O channels driver websockets
*
* Copyright (c) 2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef QIO_CHANNEL_WEBSOCK_H
#define QIO_CHANNEL_WEBSOCK_H
#include "io/channel.h"
#include "qemu/buffer.h"
#include "io/task.h"
#define TYPE_QIO_CHANNEL_WEBSOCK "qio-channel-websock"
#define QIO_CHANNEL_WEBSOCK(obj) \
OBJECT_CHECK(QIOChannelWebsock, (obj), TYPE_QIO_CHANNEL_WEBSOCK)
typedef struct QIOChannelWebsock QIOChannelWebsock;
typedef union QIOChannelWebsockMask QIOChannelWebsockMask;
union QIOChannelWebsockMask {
char c[4];
uint32_t u;
};
/**
* QIOChannelWebsock
*
* The QIOChannelWebsock class provides a channel wrapper which
* can transparently run the HTTP websockets protocol. This is
* usually used over a TCP socket, but there is actually no
* technical restriction on which type of master channel is
* used as the transport.
*
* This channel object is currently only capable of running as
* a websocket server and is a pretty crude implementation
* of it, not supporting the full websockets protocol feature
* set. It is sufficient to use with a simple websockets
* client for encapsulating VNC for noVNC in-browser client.
*/
struct QIOChannelWebsock {
QIOChannel parent;
QIOChannel *master;
Buffer encinput;
Buffer encoutput;
Buffer rawinput;
size_t payload_remain;
size_t pong_remain;
QIOChannelWebsockMask mask;
guint io_tag;
Error *io_err;
gboolean io_eof;
uint8_t opcode;
};
/**
* qio_channel_websock_new_server:
* @master: the underlying channel object
*
* Create a new websockets channel that runs the server
* side of the protocol.
*
* After creating the channel, it is mandatory to call
* the qio_channel_websock_handshake() method before attempting
* todo any I/O on the channel.
*
* Once the handshake has completed, all I/O should be done
* via the new websocket channel object and not the original
* master channel
*
* Returns: the new websockets channel object
*/
QIOChannelWebsock *
qio_channel_websock_new_server(QIOChannel *master);
/**
* qio_channel_websock_handshake:
* @ioc: the websocket channel object
* @func: the callback to invoke when completed
* @opaque: opaque data to pass to @func
* @destroy: optional callback to free @opaque
*
* Perform the websocket handshake. This method
* will return immediately and the handshake will
* continue in the background, provided the main
* loop is running. When the handshake is complete,
* or fails, the @func callback will be invoked.
*/
void qio_channel_websock_handshake(QIOChannelWebsock *ioc,
QIOTaskFunc func,
gpointer opaque,
GDestroyNotify destroy);
#endif /* QIO_CHANNEL_WEBSOCK_H */