[Qemu-devel] [PATCH v1 RFC 28/34] io: add QIOChannelWebsock class

["Daniel P. Berrange" <berrange@redhat.com>]

Add a QIOChannel subclass that can run the websocket protocol over
the top of another QIOChannel instance.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 include/io/channel-websock.h | 108 +++++
 io/Makefile.objs             |   1 +
 io/channel-websock.c         | 976 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1085 insertions(+)
 create mode 100644 include/io/channel-websock.h
 create mode 100644 io/channel-websock.c

diff --git a/include/io/channel-websock.h b/include/io/channel-websock.h
new file mode 100644
index 0000000..4641921
--- /dev/null
+++ b/include/io/channel-websock.h
@@ -0,0 +1,108 @@
+/*
+ * 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 "io/buffer.h"
+#include "io/task.h"
+
+#define TYPE_QIO_CHANNEL_WEBSOCK "qemu:io-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;
+    QIOBuffer encinput;
+    QIOBuffer encoutput;
+    QIOBuffer rawinput;
+    QIOBuffer rawoutput;
+    size_t payload_remain;
+    QIOChannelWebsockMask mask;
+    guint io_tag;
+    Error *io_err;
+    gboolean io_eof;
+};
+
+/**
+ * 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__ */
diff --git a/io/Makefile.objs b/io/Makefile.objs
index b415753..76099bf 100644
--- a/io/Makefile.objs
+++ b/io/Makefile.objs
@@ -5,3 +5,4 @@ util-obj-y += channel-unix.o
 util-obj-y += channel-socket.o
 util-obj-y += channel-file.o
 util-obj-y += channel-tls.o
+util-obj-y += channel-websock.o
diff --git a/io/channel-websock.c b/io/channel-websock.c
new file mode 100644
index 0000000..57ae737
--- /dev/null
+++ b/io/channel-websock.c
@@ -0,0 +1,976 @@
+/*
+ * 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/>.
+ *
+ */
+
+#include "io/channel-websock.h"
+#include "crypto/hash.h"
+
+#include <glib/gi18n.h>
+
+/* #define DEBUG_IOC */
+
+#ifdef DEBUG_IOC
+#define DPRINTF(fmt, ...) \
+    do { fprintf(stderr, "channel-websock: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+    do { } while (0)
+#endif
+
+/* Max amount to allow in rawinput/rawoutput buffers */
+#define QIO_CHANNEL_WEBSOCK_MAX_BUFFER 8192
+
+#define B64LEN(__x) (((__x + 2) / 3) * 12 / 3)
+#define SHA1_DIGEST_LEN 20
+
+#define QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN 24
+#define QIO_CHANNEL_WEBSOCK_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
+#define QIO_CHANNEL_WEBSOCK_GUID_LEN strlen(QIO_CHANNEL_WEBSOCK_GUID)
+
+#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_RESPONSE  \
+    "HTTP/1.1 101 Switching Protocols\r\n"      \
+    "Upgrade: websocket\r\n"                    \
+    "Connection: Upgrade\r\n"                   \
+    "Sec-WebSocket-Accept: %s\r\n"              \
+    "Sec-WebSocket-Protocol: binary\r\n"        \
+    "\r\n"
+#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM "\r\n"
+#define QIO_CHANNEL_WEBSOCK_HANDSHAKE_END "\r\n\r\n"
+#define QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION "13"
+
+#define QIO_CHANNEL_WEBSOCK_HEAD_MIN_LEN sizeof(uint16_t)
+#define QIO_CHANNEL_WEBSOCK_HEAD_MAX_LEN \
+    (QIO_CHANNEL_WEBSOCK_HEAD_MIN_LEN + sizeof(uint64_t) + sizeof(uint32_t))
+
+typedef struct QIOChannelWebsockHeader QIOChannelWebsockHeader;
+
+struct QEMU_PACKED QIOChannelWebsockHeader {
+    unsigned char b0;
+    unsigned char b1;
+    union {
+        struct QEMU_PACKED {
+            uint16_t l16;
+            QIOChannelWebsockMask m16;
+        } s16;
+        struct QEMU_PACKED {
+            uint64_t l64;
+            QIOChannelWebsockMask m64;
+        } s64;
+        QIOChannelWebsockMask m;
+    } u;
+};
+
+enum {
+    QIO_CHANNEL_WEBSOCK_OPCODE_CONTINUATION = 0x0,
+    QIO_CHANNEL_WEBSOCK_OPCODE_TEXT_FRAME = 0x1,
+    QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME = 0x2,
+    QIO_CHANNEL_WEBSOCK_OPCODE_CLOSE = 0x8,
+    QIO_CHANNEL_WEBSOCK_OPCODE_PING = 0x9,
+    QIO_CHANNEL_WEBSOCK_OPCODE_PONG = 0xA
+};
+
+static char *qio_channel_websock_handshake_entry(const char *handshake,
+                                                 size_t handshake_len,
+                                                 const char *name)
+{
+    char *begin, *end, *ret = NULL;
+    char *line = g_strdup_printf("%s%s: ",
+                                 QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM,
+                                 name);
+    begin = g_strstr_len(handshake, handshake_len, line);
+    if (begin != NULL) {
+        begin += strlen(line);
+        end = g_strstr_len(begin, handshake_len - (begin - handshake),
+                QIO_CHANNEL_WEBSOCK_HANDSHAKE_DELIM);
+        if (end != NULL) {
+            ret = g_strndup(begin, end - begin);
+        }
+    }
+    g_free(line);
+    return ret;
+}
+
+
+static int qio_channel_websock_handshake_send_response(QIOChannelWebsock *ioc,
+                                                       const char *key,
+                                                       Error **errp)
+{
+    char combined_key[QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN +
+                      QIO_CHANNEL_WEBSOCK_GUID_LEN + 1];
+    char *accept = NULL, *response = NULL;
+    size_t responselen;
+
+    g_strlcpy(combined_key, key, QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN + 1);
+    g_strlcat(combined_key, QIO_CHANNEL_WEBSOCK_GUID,
+              QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN +
+              QIO_CHANNEL_WEBSOCK_GUID_LEN + 1);
+
+    /* hash and encode it */
+    if (qcrypto_hash_base64(QCRYPTO_HASH_ALG_SHA1,
+                            combined_key,
+                            QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN +
+                            QIO_CHANNEL_WEBSOCK_GUID_LEN,
+                            &accept,
+                            errp) < 0) {
+        return -1;
+    }
+
+    response = g_strdup_printf(QIO_CHANNEL_WEBSOCK_HANDSHAKE_RESPONSE, accept);
+    responselen = strlen(response);
+    qio_buffer_reserve(&ioc->encoutput, responselen);
+    qio_buffer_append(&ioc->encoutput, response, responselen);
+
+    g_free(accept);
+    g_free(response);
+
+    return 0;
+}
+
+static int qio_channel_websock_handshake_process(QIOChannelWebsock *ioc,
+                                                 const char *line,
+                                                 size_t size,
+                                                 Error **errp)
+{
+    int ret = -1;
+    char *protocols = qio_channel_websock_handshake_entry(line, size,
+            "Sec-WebSocket-Protocol");
+    char *version = qio_channel_websock_handshake_entry(line, size,
+            "Sec-WebSocket-Version");
+    char *key = qio_channel_websock_handshake_entry(line, size,
+            "Sec-WebSocket-Key");
+
+    if (!protocols) {
+        error_setg(errp, "%s", _("Missing websocket protocol header data"));
+        goto cleanup;
+    }
+
+    if (!version) {
+        error_setg(errp, "%s", _("Missing websocket version header data"));
+        goto cleanup;
+    }
+
+    if (!key) {
+        error_setg(errp, "%s", _("Missing websocket key header data"));
+        goto cleanup;
+    }
+
+    if (!g_strrstr(protocols, "binary")) {
+        error_setg(errp, _("No 'binary' protocol is supported by client '%s'"),
+                   protocols);
+        goto cleanup;
+    }
+
+    if (!g_str_equal(version, QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION)) {
+        error_setg(errp, _("Version '%s' is not supported by client '%s'"),
+                   QIO_CHANNEL_WEBSOCK_SUPPORTED_VERSION, version);
+        goto cleanup;
+    }
+
+    if (strlen(key) != QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN) {
+        error_setg(errp, _("Key length '%zu' was not as expected '%d'"),
+                   strlen(key), QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN);
+        goto cleanup;
+    }
+
+    ret = qio_channel_websock_handshake_send_response(ioc, key, errp);
+
+ cleanup:
+    g_free(protocols);
+    g_free(version);
+    g_free(key);
+    return ret;
+}
+
+static int qio_channel_websock_handshake_read(QIOChannelWebsock *ioc,
+                                              Error **errp)
+{
+    char *handshake_end;
+    ssize_t ret;
+    /* Typical HTTP headers from novnc are 512 bytes, so limiting
+     * total header size to 4096 is easily enough. */
+    size_t want = 4096 - ioc->encinput.offset;
+    qio_buffer_reserve(&ioc->encinput, want);
+    ret = qio_channel_read(ioc->master,
+                           (char *)qio_buffer_end(&ioc->encinput), want, errp);
+    if (ret < 0) {
+        return -1;
+    }
+    ioc->encinput.offset += ret;
+
+    handshake_end = g_strstr_len((char *)ioc->encinput.buffer,
+                                 ioc->encinput.offset,
+                                 QIO_CHANNEL_WEBSOCK_HANDSHAKE_END);
+    if (!handshake_end) {
+        if (ioc->encinput.offset >= 4096) {
+            error_setg(errp, "%s",
+                       _("End of headers not found in first 4096 bytes"));
+            return -1;
+        } else {
+            return 0;
+        }
+    }
+
+    if (qio_channel_websock_handshake_process(ioc,
+                                              (char *)ioc->encinput.buffer,
+                                              ioc->encinput.offset,
+                                              errp) < 0) {
+        return -1;
+    }
+
+    qio_buffer_advance(&ioc->encinput,
+                       handshake_end - (char *)ioc->encinput.buffer +
+                       strlen(QIO_CHANNEL_WEBSOCK_HANDSHAKE_END));
+    return 1;
+}
+
+static gboolean qio_channel_websock_handshake_send(QIOChannel *ioc,
+                                                   GIOCondition condition,
+                                                   gpointer user_data)
+{
+    QIOTask *task = QIO_TASK(user_data);
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(task->source);
+    Error *err = NULL;
+    ssize_t ret;
+
+    DPRINTF("Sending websock handshake reply %p\n", wioc);
+    ret = qio_channel_write(wioc->master,
+                            (char *)wioc->encoutput.buffer,
+                            wioc->encoutput.offset,
+                            &err);
+
+    if (ret < 0) {
+        qio_task_abort(task, err);
+        DPRINTF("Error sending websock handshake reply %p: %s\n",
+                wioc, error_get_pretty(err));
+        error_free(err);
+        return FALSE;
+    }
+
+    qio_buffer_advance(&wioc->encoutput, ret);
+    if (wioc->encoutput.offset == 0) {
+        DPRINTF("Finished sending websock handshake %p\n",
+                wioc);
+        qio_task_complete(task);
+        return FALSE;
+    }
+    return TRUE;
+}
+
+static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc,
+                                                 GIOCondition condition,
+                                                 gpointer user_data)
+{
+    QIOTask *task = QIO_TASK(user_data);
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(task->source);
+    Error *err = NULL;
+    int ret;
+
+    DPRINTF("Reading websock handshake request %p\n", wioc);
+    ret = qio_channel_websock_handshake_read(wioc, &err);
+    if (ret < 0) {
+        DPRINTF("Error reading websock handshake %s\n",
+                error_get_pretty(err));
+        qio_task_abort(task, err);
+        error_free(err);
+        return FALSE;
+    }
+    if (ret == 0) {
+        DPRINTF("Blocking on more request data\n");
+        /* need more data still */
+        return TRUE;
+    }
+
+    DPRINTF("Websock request complete, adding watch for reply %p\n",
+            wioc);
+
+    object_ref(OBJECT(task));
+    qio_channel_add_watch_full(
+        wioc->master,
+        G_PRIORITY_DEFAULT,
+        G_IO_OUT,
+        qio_channel_websock_handshake_send,
+        task,
+        (GDestroyNotify)object_unref);
+    return FALSE;
+}
+
+
+static void qio_channel_websock_encode(QIOChannelWebsock *ioc)
+{
+    size_t header_size = 0;
+    unsigned char opcode = QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME;
+    union {
+        char buf[QIO_CHANNEL_WEBSOCK_HEAD_MAX_LEN];
+        QIOChannelWebsockHeader ws;
+    } header;
+
+    DPRINTF("Encoding pending raw output %zu %p\n",
+            ioc->rawoutput.offset, ioc);
+    if (!ioc->rawoutput.offset) {
+        return;
+    }
+
+    header.ws.b0 = 0x80 | (opcode & 0x0f);
+    if (ioc->rawoutput.offset <= 125) {
+        header.ws.b1 = (uint8_t)ioc->rawoutput.offset;
+        header_size = 2;
+    } else if (ioc->rawoutput.offset < 65536) {
+        header.ws.b1 = 0x7e;
+        header.ws.u.s16.l16 = cpu_to_be16((uint16_t)ioc->rawoutput.offset);
+        header_size = 4;
+    } else {
+        header.ws.b1 = 0x7f;
+        header.ws.u.s64.l64 = cpu_to_be64(ioc->rawoutput.offset);
+        header_size = 10;
+    }
+
+    qio_buffer_reserve(&ioc->encoutput, header_size + ioc->rawoutput.offset);
+    qio_buffer_append(&ioc->encoutput, header.buf, header_size);
+    qio_buffer_append(&ioc->encoutput, ioc->rawoutput.buffer,
+                      ioc->rawoutput.offset);
+    qio_buffer_reset(&ioc->rawoutput);
+    DPRINTF("Have %zu bytes encoded output %p\n",
+            ioc->encoutput.offset, ioc);
+}
+
+
+static ssize_t qio_channel_websock_decode_header(QIOChannelWebsock *ioc,
+                                                 Error **errp)
+{
+    unsigned char opcode = 0, fin = 0, has_mask = 0;
+    size_t header_size = 0;
+    size_t payload_len;
+    QIOChannelWebsockHeader *header =
+        (QIOChannelWebsockHeader *)ioc->encinput.buffer;
+
+    if (ioc->payload_remain) {
+        error_setg(errp,
+                   _("Decoding header but %zu bytes of payload remain"),
+                   ioc->payload_remain);
+        return -1;
+    }
+    if (ioc->encinput.offset < QIO_CHANNEL_WEBSOCK_HEAD_MIN_LEN + 4) {
+        /* header not complete */
+        return QIO_CHANNEL_ERR_BLOCK;
+    }
+
+    fin = (header->b0 & 0x80) >> 7;
+    opcode = header->b0 & 0x0f;
+    has_mask = (header->b1 & 0x80) >> 7;
+    payload_len = header->b1 & 0x7f;
+
+    if (opcode == QIO_CHANNEL_WEBSOCK_OPCODE_CLOSE) {
+        /* disconnect */
+        return 0;
+    }
+
+    /* Websocket frame sanity check:
+     * * Websocket fragmentation is not supported.
+     * * All  websockets frames sent by a client have to be masked.
+     * * Only binary encoding is supported.
+     */
+    if (!fin) {
+        error_setg(errp, "%s", _("websocket fragmentation is not supported"));
+        return -1;
+    }
+    if (!has_mask) {
+        error_setg(errp, "%s", _("websocket frames must be masked"));
+        return -1;
+    }
+    if (opcode != QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME) {
+        error_setg(errp, "%s", _("only binary websocket frames are supported"));
+        return -1;
+    }
+
+    if (payload_len < 126) {
+        ioc->payload_remain = payload_len;
+        header_size = 6;
+        ioc->mask = header->u.m;
+    } else if (payload_len == 126 && ioc->encinput.offset >= 8) {
+        ioc->payload_remain = be16_to_cpu(header->u.s16.l16);
+        header_size = 8;
+        ioc->mask = header->u.s16.m16;
+    } else if (payload_len == 127 && ioc->encinput.offset >= 14) {
+        ioc->payload_remain = be64_to_cpu(header->u.s64.l64);
+        header_size = 14;
+        ioc->mask = header->u.s64.m64;
+    } else {
+        /* header not complete */
+        return QIO_CHANNEL_ERR_BLOCK;
+    }
+
+    qio_buffer_advance(&ioc->encinput, header_size);
+    return 1;
+}
+
+
+static ssize_t qio_channel_websock_decode_payload(QIOChannelWebsock *ioc,
+                                                  Error **errp)
+{
+    size_t i;
+    size_t payload_len;
+    uint32_t *payload32;
+
+    if (!ioc->payload_remain) {
+        error_setg(errp, "%s",
+                   _("Decoding payload but no bytes of payload remain"));
+        return -1;
+    }
+
+    /* If we aren't at the end of the payload, then drop
+     * off the last bytes, so we're always multiple of 4
+     * for purpose of unmasking, except at end of payload
+     */
+    if (ioc->encinput.offset < ioc->payload_remain) {
+        payload_len = ioc->encinput.offset - (ioc->encinput.offset % 4);
+    } else {
+        payload_len = ioc->payload_remain;
+    }
+    if (payload_len == 0) {
+        return QIO_CHANNEL_ERR_BLOCK;
+    }
+
+    ioc->payload_remain -= payload_len;
+
+    /* unmask frame */
+    /* process 1 frame (32 bit op) */
+    payload32 = (uint32_t *)ioc->encinput.buffer;
+    for (i = 0; i < payload_len / 4; i++) {
+        payload32[i] ^= ioc->mask.u;
+    }
+    /* process the remaining bytes (if any) */
+    for (i *= 4; i < payload_len; i++) {
+        ioc->encinput.buffer[i] ^= ioc->mask.c[i % 4];
+    }
+
+    qio_buffer_reserve(&ioc->rawinput, payload_len);
+    qio_buffer_append(&ioc->rawinput, ioc->encinput.buffer, payload_len);
+    qio_buffer_advance(&ioc->encinput, payload_len);
+    return payload_len;
+}
+
+
+QIOChannelWebsock *
+qio_channel_websock_new_server(QIOChannel *master)
+{
+    QIOChannelWebsock *wioc;
+
+    wioc = QIO_CHANNEL_WEBSOCK(object_new(TYPE_QIO_CHANNEL_WEBSOCK));
+
+    wioc->master = master;
+    object_ref(OBJECT(master));
+
+    return wioc;
+}
+
+void qio_channel_websock_handshake(QIOChannelWebsock *ioc,
+                                   QIOTaskFunc func,
+                                   gpointer opaque,
+                                   GDestroyNotify destroy)
+{
+    QIOTask *task;
+
+    task = qio_task_new(OBJECT(ioc),
+                        func,
+                        opaque,
+                        destroy);
+
+    DPRINTF("Adding watch on master %p for websocket %p handshake\n",
+            ioc->master, ioc);
+    qio_channel_add_watch_full(ioc->master,
+                               G_PRIORITY_DEFAULT,
+                               G_IO_IN,
+                               qio_channel_websock_handshake_io,
+                               task,
+                               (GDestroyNotify)object_unref);
+}
+
+static void qio_channel_websock_init(Object *obj G_GNUC_UNUSED)
+{
+}
+
+
+static void qio_channel_websock_finalize(Object *obj)
+{
+    QIOChannelWebsock *ioc = QIO_CHANNEL_WEBSOCK(obj);
+
+    qio_buffer_free(&ioc->encinput);
+    qio_buffer_free(&ioc->encoutput);
+    qio_buffer_free(&ioc->rawinput);
+    qio_buffer_free(&ioc->rawoutput);
+    object_unref(OBJECT(ioc->master));
+    if (ioc->io_tag) {
+        g_source_remove(ioc->io_tag);
+    }
+    if (ioc->io_err) {
+        error_free(ioc->io_err);
+    }
+}
+
+
+static ssize_t qio_channel_websock_read_wire(QIOChannelWebsock *ioc,
+                                             Error **errp)
+{
+    ssize_t ret;
+
+    DPRINTF("Have %zu bytes %p\n", ioc->encoutput.offset, ioc);
+    if (ioc->encinput.offset < 4096) {
+        size_t want = 4096 - ioc->encinput.offset;
+
+        qio_buffer_reserve(&ioc->encinput, want);
+        ret = qio_channel_read(ioc->master,
+                               (char *)ioc->encinput.buffer +
+                               ioc->encinput.offset,
+                               want,
+                               errp);
+        if (ret < 0) {
+            return ret;
+        }
+        if (ret == 0 &&
+            ioc->encinput.offset == 0) {
+            DPRINTF("EOF on wire & no more enc data availabl\n");
+            return 0;
+        }
+        ioc->encinput.offset += ret;
+        DPRINTF("Now have %zu bytes enc input\n", ioc->encinput.offset);
+    }
+
+    if (ioc->payload_remain == 0) {
+        DPRINTF("Looking to decode header\n");
+        ret = qio_channel_websock_decode_header(ioc, errp);
+        if (ret < 0) {
+            return ret;
+        }
+        if (ret == 0) {
+            DPRINTF("EOF when decoding header\n");
+            return 0;
+        }
+    }
+    DPRINTF("Looking to decode payload %zu\n", ioc->payload_remain);
+
+    ret = qio_channel_websock_decode_payload(ioc, errp);
+    if (ret < 0) {
+        return ret;
+    }
+    DPRINTF("Now have %zu bytes raw input\n", ioc->rawinput.offset);
+    return ret;
+}
+
+
+static ssize_t qio_channel_websock_write_wire(QIOChannelWebsock *ioc,
+                                              Error **errp)
+{
+    ssize_t ret;
+    ssize_t done = 0;
+    qio_channel_websock_encode(ioc);
+
+    DPRINTF("Writing %zu bytes %p\n", ioc->encoutput.offset, ioc);
+    while (ioc->encoutput.offset > 0) {
+        ret = qio_channel_write(ioc->master,
+                                (char *)ioc->encoutput.buffer,
+                                ioc->encoutput.offset,
+                                errp);
+        if (ret < 0) {
+            if (ret == QIO_CHANNEL_ERR_BLOCK &&
+                done > 0) {
+                DPRINTF("Blocking but wrote %zu\n", done);
+                return done;
+            } else {
+                DPRINTF("Error while writing %s\n",
+                        error_get_pretty(*errp));
+                return ret;
+            }
+        }
+        qio_buffer_advance(&ioc->encoutput, ret);
+        done += ret;
+    }
+    DPRINTF("Wrote %zu total\n", done);
+    return done;
+}
+
+
+static void qio_channel_websock_flush_free(gpointer user_data)
+{
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(user_data);
+    object_unref(OBJECT(wioc));
+}
+
+static void qio_channel_websock_set_watch(QIOChannelWebsock *ioc);
+
+static gboolean qio_channel_websock_flush(QIOChannel *ioc,
+                                          GIOCondition condition,
+                                          gpointer user_data)
+{
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(user_data);
+    ssize_t ret;
+
+    DPRINTF("Websock master flush %p %d\n", ioc, condition);
+    if (condition & G_IO_OUT) {
+        ret = qio_channel_websock_write_wire(wioc, &wioc->io_err);
+        if (ret < 0) {
+            goto cleanup;
+        }
+    }
+
+    if (condition & G_IO_IN) {
+        ret = qio_channel_websock_read_wire(wioc, &wioc->io_err);
+        if (ret < 0) {
+            goto cleanup;
+        }
+        if (ret == 0) {
+            DPRINTF("Got EOF when reading %p\n", wioc);
+            wioc->io_eof = TRUE;
+        }
+    }
+
+ cleanup:
+    qio_channel_websock_set_watch(wioc);
+    return FALSE;
+}
+
+
+static void qio_channel_websock_unset_watch(QIOChannelWebsock *ioc)
+{
+    if (ioc->io_tag) {
+        DPRINTF("Removing old master watch %u %p\n", ioc->io_tag, ioc);
+        g_source_remove(ioc->io_tag);
+        ioc->io_tag = 0;
+    }
+}
+
+static void qio_channel_websock_set_watch(QIOChannelWebsock *ioc)
+{
+    GIOCondition cond = 0;
+
+    qio_channel_websock_unset_watch(ioc);
+
+    if (ioc->io_err) {
+        DPRINTF("Not adding master watch due to error %p %s\n",
+                ioc, error_get_pretty(ioc->io_err));
+        return;
+    }
+
+    if (ioc->encoutput.offset) {
+        cond |= G_IO_OUT;
+    }
+    if (ioc->encinput.offset < QIO_CHANNEL_WEBSOCK_MAX_BUFFER &&
+        !ioc->io_eof) {
+        cond |= G_IO_IN;
+    }
+
+    DPRINTF("Cond %d output=%zu input=%zu eof=%d\n",
+            cond, ioc->encoutput.offset, ioc->encinput.offset, ioc->io_eof);
+    if (cond) {
+        object_ref(OBJECT(ioc));
+        ioc->io_tag =
+            qio_channel_add_watch_full(ioc->master,
+                                       G_PRIORITY_DEFAULT,
+                                       cond,
+                                       qio_channel_websock_flush,
+                                       ioc,
+                                       qio_channel_websock_flush_free);
+    }
+}
+
+
+static ssize_t qio_channel_websock_readv(QIOChannel *ioc,
+                                         const struct iovec *iov,
+                                         size_t niov,
+                                         int **fds,
+                                         size_t *nfds,
+                                         int flags,
+                                         Error **errp)
+{
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc);
+    size_t i;
+    ssize_t got = 0;
+    ssize_t ret;
+    DPRINTF("Read ioc %p %zu %p\n", iov, niov, ioc);
+    if (fds || nfds) {
+        error_setg(errp, "%s",
+                   _("Cannot receive file descriptors over websocket channel"));
+        return -1;
+    }
+    if (flags) {
+        error_setg(errp, "Flags %x not supported in websocket channel", flags);
+        return  -1;
+    }
+
+    if (wioc->io_err) {
+        *errp = error_copy(wioc->io_err);
+        return -1;
+    }
+
+    if (!wioc->rawinput.offset) {
+        ret = qio_channel_websock_read_wire(QIO_CHANNEL_WEBSOCK(ioc), errp);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    for (i = 0 ; i < niov ; i++) {
+        size_t want = iov[i].iov_len;
+        if (want > (wioc->rawinput.offset - got)) {
+            want = (wioc->rawinput.offset - got);
+        }
+
+        memcpy(iov[i].iov_base,
+               wioc->rawinput.buffer + got,
+               want);
+        got += want;
+
+        if (want < iov[i].iov_len) {
+            break;
+        }
+    }
+
+    qio_buffer_advance(&wioc->rawinput, got);
+    qio_channel_websock_set_watch(wioc);
+    DPRINTF("Returning %zu\n", got);
+    return got;
+}
+
+
+static ssize_t qio_channel_websock_writev(QIOChannel *ioc,
+                                          const struct iovec *iov,
+                                          size_t niov,
+                                          int *fds,
+                                          size_t nfds,
+                                          int flags,
+                                          Error **errp)
+{
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc);
+    size_t i;
+    ssize_t done = 0;
+    ssize_t ret;
+
+    if (fds || nfds) {
+        error_setg(errp, "%s",
+                   _("Cannot send file descriptors over websocket channel"));
+        return -1;
+    }
+    if (flags) {
+        error_setg(errp, "Flags %x not supported in websocket channel", flags);
+        return  -1;
+    }
+
+    DPRINTF("Writev %p %zu %p err=%p\n", iov, niov, ioc, wioc->io_err);
+    if (wioc->io_err) {
+        *errp = error_copy(wioc->io_err);
+        return -1;
+    }
+
+    if (wioc->io_eof) {
+        error_setg(errp, "%s", "Broken pipe");
+        return -1;
+    }
+
+    for (i = 0; i < niov; i++) {
+        size_t want = iov[i].iov_len;
+        if ((want + wioc->rawoutput.offset) > QIO_CHANNEL_WEBSOCK_MAX_BUFFER) {
+            want = (QIO_CHANNEL_WEBSOCK_MAX_BUFFER - wioc->rawoutput.offset);
+        }
+        if (want == 0) {
+            goto done;
+        }
+
+        qio_buffer_reserve(&wioc->rawoutput, want);
+        qio_buffer_append(&wioc->rawoutput, iov[i].iov_base, want);
+        done += want;
+        if (want < iov[i].iov_len) {
+            break;
+        }
+    }
+
+ done:
+    ret = qio_channel_websock_write_wire(wioc, errp);
+    if (ret < 0 &&
+        ret != QIO_CHANNEL_ERR_BLOCK) {
+        qio_channel_websock_unset_watch(wioc);
+        return -1;
+    }
+
+    qio_channel_websock_set_watch(wioc);
+
+    if (done == 0) {
+        return QIO_CHANNEL_ERR_BLOCK;
+    }
+
+    return done;
+}
+
+static void qio_channel_websock_set_blocking(QIOChannel *ioc,
+                                             bool enabled)
+{
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc);
+
+    qio_channel_set_blocking(wioc->master, enabled);
+}
+
+static int qio_channel_websock_close(QIOChannel *ioc,
+                                     Error **errp)
+{
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc);
+
+    return qio_channel_close(wioc->master, errp);
+}
+
+typedef struct QIOChannelWebsockSource QIOChannelWebsockSource;
+struct QIOChannelWebsockSource {
+    GSource parent;
+    QIOChannelWebsock *wioc;
+    GIOCondition condition;
+};
+
+static gboolean
+qio_channel_websock_source_prepare(GSource *source,
+                                   gint *timeout)
+{
+    QIOChannelWebsockSource *wsource = (QIOChannelWebsockSource *)source;
+    GIOCondition cond = 0;
+    *timeout = -1;
+
+    if (wsource->wioc->rawinput.offset) {
+        cond |= G_IO_IN;
+    }
+    if (wsource->wioc->rawoutput.offset < QIO_CHANNEL_WEBSOCK_MAX_BUFFER) {
+        cond |= G_IO_OUT;
+    }
+
+#if 0
+    DPRINTF("Prep source %d cond %d input=%zu output=%zu\n",
+            wsource->condition, cond,
+            wsource->wioc->rawinput.offset,
+            wsource->wioc->rawoutput.offset);
+#endif
+
+    return cond & wsource->condition;
+}
+
+static gboolean
+qio_channel_websock_source_check(GSource *source)
+{
+    QIOChannelWebsockSource *wsource = (QIOChannelWebsockSource *)source;
+    GIOCondition cond = 0;
+
+    if (wsource->wioc->rawinput.offset) {
+        cond |= G_IO_IN;
+    }
+    if (wsource->wioc->rawoutput.offset < QIO_CHANNEL_WEBSOCK_MAX_BUFFER) {
+        cond |= G_IO_OUT;
+    }
+
+    if (cond & wsource->condition) {
+        DPRINTF("Check source %d cond %d input=%zu output=%zu\n",
+                wsource->condition, cond,
+                wsource->wioc->rawinput.offset,
+                wsource->wioc->rawoutput.offset);
+    }
+    return cond & wsource->condition;
+}
+
+static gboolean
+qio_channel_websock_source_dispatch(GSource *source,
+                                    GSourceFunc callback,
+                                    gpointer user_data)
+{
+    QIOChannelFunc func = (QIOChannelFunc)callback;
+    QIOChannelWebsockSource *wsource = (QIOChannelWebsockSource *)source;
+    GIOCondition cond = 0;
+
+    if (wsource->wioc->rawinput.offset) {
+        cond |= G_IO_IN;
+    }
+    if (wsource->wioc->rawoutput.offset < QIO_CHANNEL_WEBSOCK_MAX_BUFFER) {
+        cond |= G_IO_OUT;
+    }
+
+    DPRINTF("Disp source %d cond %d input=%zu output=%zu\n",
+            wsource->condition, cond,
+            wsource->wioc->rawinput.offset,
+            wsource->wioc->rawoutput.offset);
+    return (*func)(QIO_CHANNEL(wsource->wioc),
+                   (cond & wsource->condition),
+                   user_data);
+}
+
+static void
+qio_channel_websock_source_finalize(GSource *source)
+{
+    QIOChannelWebsockSource *ssource = (QIOChannelWebsockSource *)source;
+
+    object_unref(OBJECT(ssource->wioc));
+}
+
+GSourceFuncs qio_channel_websock_source_funcs = {
+    qio_channel_websock_source_prepare,
+    qio_channel_websock_source_check,
+    qio_channel_websock_source_dispatch,
+    qio_channel_websock_source_finalize
+};
+
+static GSource *qio_channel_websock_create_watch(QIOChannel *ioc,
+                                                 GIOCondition condition)
+{
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc);
+    QIOChannelWebsockSource *ssource;
+    GSource *source;
+
+    DPRINTF("Creating websock watch %p cond=%d\n", wioc, condition);
+    source = g_source_new(&qio_channel_websock_source_funcs,
+                          sizeof(QIOChannelWebsockSource));
+    g_source_set_name(source, "QIOChannelWebsock");
+    ssource = (QIOChannelWebsockSource *)source;
+
+    ssource->wioc = wioc;
+    object_ref(OBJECT(wioc));
+
+    ssource->condition = condition;
+
+    qio_channel_websock_set_watch(wioc);
+    return source;
+}
+
+static void qio_channel_websock_class_init(ObjectClass *klass,
+                                           void *class_data G_GNUC_UNUSED)
+{
+    QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+    ioc_klass->io_writev = qio_channel_websock_writev;
+    ioc_klass->io_readv = qio_channel_websock_readv;
+    ioc_klass->io_set_blocking = qio_channel_websock_set_blocking;
+    ioc_klass->io_close = qio_channel_websock_close;
+    ioc_klass->io_create_watch = qio_channel_websock_create_watch;
+}
+
+static const TypeInfo qio_channel_websock_info = {
+    .parent = TYPE_QIO_CHANNEL,
+    .name = TYPE_QIO_CHANNEL_WEBSOCK,
+    .instance_size = sizeof(QIOChannelWebsock),
+    .instance_init = qio_channel_websock_init,
+    .instance_finalize = qio_channel_websock_finalize,
+    .class_init = qio_channel_websock_class_init,
+};
+
+static void qio_channel_websock_register_types(void)
+{
+    type_register_static(&qio_channel_websock_info);
+}
+
+type_init(qio_channel_websock_register_types);
-- 
2.1.0