io: add QIOChannelWebsock class

Add a QIOChannel subclass that can run the websocket protocol over
the top of another QIOChannel instance. This initial implementation
is only capable of acting as a websockets server. There is no support
for acting as a websockets client yet.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

2 files changed, 963 insertions, 0 deletions

diff --git a/io/Makefile.objs b/io/Makefile.objs
index a48011b726..e3771b1ac1 100644
--- a/io/Makefile.objs
+++ b/io/Makefile.objs
@@ -3,4 +3,5 @@ io-obj-y += channel-file.o
 io-obj-y += channel-socket.o
 io-obj-y += channel-tls.o
 io-obj-y += channel-watch.o
+io-obj-y += channel-websock.o
 io-obj-y += task.o
diff --git a/io/channel-websock.c b/io/channel-websock.c
new file mode 100644
index 0000000000..9273a8b31e
--- /dev/null
+++ b/io/channel-websock.c
@@ -0,0 +1,962 @@
+/*
+ * 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 "trace.h"
+
+
+/* Max amount to allow in rawinput/rawoutput buffers */
+#define QIO_CHANNEL_WEBSOCK_MAX_BUFFER 8192
+
+#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_HEADER_PROTOCOL "Sec-WebSocket-Protocol"
+#define QIO_CHANNEL_WEBSOCK_HEADER_VERSION "Sec-WebSocket-Version"
+#define QIO_CHANNEL_WEBSOCK_HEADER_KEY "Sec-WebSocket-Key"
+
+#define QIO_CHANNEL_WEBSOCK_PROTOCOL_BINARY "binary"
+
+#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"
+
+/* The websockets packet header is variable length
+ * depending on the size of the payload... */
+
+/* ...length when using 7-bit payload length */
+#define QIO_CHANNEL_WEBSOCK_HEADER_LEN_7_BIT 6
+/* ...length when using 16-bit payload length */
+#define QIO_CHANNEL_WEBSOCK_HEADER_LEN_16_BIT 8
+/* ...length when using 64-bit payload length */
+#define QIO_CHANNEL_WEBSOCK_HEADER_LEN_64_BIT 14
+
+/* Length of the optional data mask field in header */
+#define QIO_CHANNEL_WEBSOCK_HEADER_LEN_MASK 4
+
+/* Maximum length that can fit in 7-bit payload size */
+#define QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_THRESHOLD_7_BIT 126
+/* Maximum length that can fit in 16-bit payload size */
+#define QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_THRESHOLD_16_BIT 65536
+
+/* Magic 7-bit length to indicate use of 16-bit payload length */
+#define QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_MAGIC_16_BIT 126
+/* Magic 7-bit length to indicate use of 64-bit payload length */
+#define QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_MAGIC_64_BIT 127
+
+/* Bitmasks & shifts for accessing header fields */
+#define QIO_CHANNEL_WEBSOCK_HEADER_FIELD_FIN 0x80
+#define QIO_CHANNEL_WEBSOCK_HEADER_FIELD_OPCODE 0x0f
+#define QIO_CHANNEL_WEBSOCK_HEADER_FIELD_HAS_MASK 0x80
+#define QIO_CHANNEL_WEBSOCK_HEADER_FIELD_PAYLOAD_LEN 0x7f
+#define QIO_CHANNEL_WEBSOCK_HEADER_SHIFT_FIN 7
+#define QIO_CHANNEL_WEBSOCK_HEADER_SHIFT_HAS_MASK 7
+
+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);
+    buffer_reserve(&ioc->encoutput, responselen);
+    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, QIO_CHANNEL_WEBSOCK_HEADER_PROTOCOL);
+    char *version = qio_channel_websock_handshake_entry(
+        line, size, QIO_CHANNEL_WEBSOCK_HEADER_VERSION);
+    char *key = qio_channel_websock_handshake_entry(
+        line, size, QIO_CHANNEL_WEBSOCK_HEADER_KEY);
+
+    if (!protocols) {
+        error_setg(errp, "Missing websocket protocol header data");
+        goto cleanup;
+    }
+
+    if (!version) {
+        error_setg(errp, "Missing websocket version header data");
+        goto cleanup;
+    }
+
+    if (!key) {
+        error_setg(errp, "Missing websocket key header data");
+        goto cleanup;
+    }
+
+    if (!g_strrstr(protocols, QIO_CHANNEL_WEBSOCK_PROTOCOL_BINARY)) {
+        error_setg(errp, "No '%s' protocol is supported by client '%s'",
+                   QIO_CHANNEL_WEBSOCK_PROTOCOL_BINARY, 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;
+    buffer_reserve(&ioc->encinput, want);
+    ret = qio_channel_read(ioc->master,
+                           (char *)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,
+                       "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;
+    }
+
+    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 = user_data;
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(
+        qio_task_get_source(task));
+    Error *err = NULL;
+    ssize_t ret;
+
+    ret = qio_channel_write(wioc->master,
+                            (char *)wioc->encoutput.buffer,
+                            wioc->encoutput.offset,
+                            &err);
+
+    if (ret < 0) {
+        trace_qio_channel_websock_handshake_fail(ioc);
+        qio_task_abort(task, err);
+        error_free(err);
+        return FALSE;
+    }
+
+    buffer_advance(&wioc->encoutput, ret);
+    if (wioc->encoutput.offset == 0) {
+        trace_qio_channel_websock_handshake_complete(ioc);
+        qio_task_complete(task);
+        return FALSE;
+    }
+    trace_qio_channel_websock_handshake_pending(ioc, G_IO_OUT);
+    return TRUE;
+}
+
+static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc,
+                                                 GIOCondition condition,
+                                                 gpointer user_data)
+{
+    QIOTask *task = user_data;
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(
+        qio_task_get_source(task));
+    Error *err = NULL;
+    int ret;
+
+    ret = qio_channel_websock_handshake_read(wioc, &err);
+    if (ret < 0) {
+        trace_qio_channel_websock_handshake_fail(ioc);
+        qio_task_abort(task, err);
+        error_free(err);
+        return FALSE;
+    }
+    if (ret == 0) {
+        trace_qio_channel_websock_handshake_pending(ioc, G_IO_IN);
+        /* need more data still */
+        return TRUE;
+    }
+
+    object_ref(OBJECT(task));
+    trace_qio_channel_websock_handshake_reply(ioc);
+    qio_channel_add_watch(
+        wioc->master,
+        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;
+    union {
+        char buf[QIO_CHANNEL_WEBSOCK_HEADER_LEN_64_BIT];
+        QIOChannelWebsockHeader ws;
+    } header;
+
+    if (!ioc->rawoutput.offset) {
+        return;
+    }
+
+    header.ws.b0 = (1 << QIO_CHANNEL_WEBSOCK_HEADER_SHIFT_FIN) |
+        (QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME &
+         QIO_CHANNEL_WEBSOCK_HEADER_FIELD_OPCODE);
+    if (ioc->rawoutput.offset <
+        QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_THRESHOLD_7_BIT) {
+        header.ws.b1 = (uint8_t)ioc->rawoutput.offset;
+        header_size = QIO_CHANNEL_WEBSOCK_HEADER_LEN_7_BIT;
+    } else if (ioc->rawoutput.offset <
+               QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_THRESHOLD_16_BIT) {
+        header.ws.b1 = QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_MAGIC_16_BIT;
+        header.ws.u.s16.l16 = cpu_to_be16((uint16_t)ioc->rawoutput.offset);
+        header_size = QIO_CHANNEL_WEBSOCK_HEADER_LEN_16_BIT;
+    } else {
+        header.ws.b1 = QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_MAGIC_64_BIT;
+        header.ws.u.s64.l64 = cpu_to_be64(ioc->rawoutput.offset);
+        header_size = QIO_CHANNEL_WEBSOCK_HEADER_LEN_64_BIT;
+    }
+    header_size -= QIO_CHANNEL_WEBSOCK_HEADER_LEN_MASK;
+
+    buffer_reserve(&ioc->encoutput, header_size + ioc->rawoutput.offset);
+    buffer_append(&ioc->encoutput, header.buf, header_size);
+    buffer_append(&ioc->encoutput, ioc->rawoutput.buffer,
+                  ioc->rawoutput.offset);
+    buffer_reset(&ioc->rawoutput);
+}
+
+
+static ssize_t qio_channel_websock_decode_header(QIOChannelWebsock *ioc,
+                                                 Error **errp)
+{
+    unsigned char opcode, fin, has_mask;
+    size_t header_size;
+    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_HEADER_LEN_7_BIT) {
+        /* header not complete */
+        return QIO_CHANNEL_ERR_BLOCK;
+    }
+
+    fin = (header->b0 & QIO_CHANNEL_WEBSOCK_HEADER_FIELD_FIN) >>
+        QIO_CHANNEL_WEBSOCK_HEADER_SHIFT_FIN;
+    opcode = header->b0 & QIO_CHANNEL_WEBSOCK_HEADER_FIELD_OPCODE;
+    has_mask = (header->b1 & QIO_CHANNEL_WEBSOCK_HEADER_FIELD_HAS_MASK) >>
+        QIO_CHANNEL_WEBSOCK_HEADER_SHIFT_HAS_MASK;
+    payload_len = header->b1 & QIO_CHANNEL_WEBSOCK_HEADER_FIELD_PAYLOAD_LEN;
+
+    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, "websocket fragmentation is not supported");
+        return -1;
+    }
+    if (!has_mask) {
+        error_setg(errp, "websocket frames must be masked");
+        return -1;
+    }
+    if (opcode != QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME) {
+        error_setg(errp, "only binary websocket frames are supported");
+        return -1;
+    }
+
+    if (payload_len < QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_MAGIC_16_BIT) {
+        ioc->payload_remain = payload_len;
+        header_size = QIO_CHANNEL_WEBSOCK_HEADER_LEN_7_BIT;
+        ioc->mask = header->u.m;
+    } else if (payload_len == QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_MAGIC_16_BIT &&
+               ioc->encinput.offset >= QIO_CHANNEL_WEBSOCK_HEADER_LEN_16_BIT) {
+        ioc->payload_remain = be16_to_cpu(header->u.s16.l16);
+        header_size = QIO_CHANNEL_WEBSOCK_HEADER_LEN_16_BIT;
+        ioc->mask = header->u.s16.m16;
+    } else if (payload_len == QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_MAGIC_64_BIT &&
+               ioc->encinput.offset >= QIO_CHANNEL_WEBSOCK_HEADER_LEN_64_BIT) {
+        ioc->payload_remain = be64_to_cpu(header->u.s64.l64);
+        header_size = QIO_CHANNEL_WEBSOCK_HEADER_LEN_64_BIT;
+        ioc->mask = header->u.s64.m64;
+    } else {
+        /* header not complete */
+        return QIO_CHANNEL_ERR_BLOCK;
+    }
+
+    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,
+                   "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];
+    }
+
+    buffer_reserve(&ioc->rawinput, payload_len);
+    buffer_append(&ioc->rawinput, ioc->encinput.buffer, payload_len);
+    buffer_advance(&ioc->encinput, payload_len);
+    return payload_len;
+}
+
+
+QIOChannelWebsock *
+qio_channel_websock_new_server(QIOChannel *master)
+{
+    QIOChannelWebsock *wioc;
+    QIOChannel *ioc;
+
+    wioc = QIO_CHANNEL_WEBSOCK(object_new(TYPE_QIO_CHANNEL_WEBSOCK));
+    ioc = QIO_CHANNEL(wioc);
+
+    wioc->master = master;
+    if (master->features & (1 << QIO_CHANNEL_FEATURE_SHUTDOWN)) {
+        ioc->features |= (1 << QIO_CHANNEL_FEATURE_SHUTDOWN);
+    }
+    object_ref(OBJECT(master));
+
+    trace_qio_channel_websock_new_server(wioc, 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);
+
+    trace_qio_channel_websock_handshake_start(ioc);
+    trace_qio_channel_websock_handshake_pending(ioc, G_IO_IN);
+    qio_channel_add_watch(ioc->master,
+                          G_IO_IN,
+                          qio_channel_websock_handshake_io,
+                          task,
+                          NULL);
+}
+
+
+static void qio_channel_websock_finalize(Object *obj)
+{
+    QIOChannelWebsock *ioc = QIO_CHANNEL_WEBSOCK(obj);
+
+    buffer_free(&ioc->encinput);
+    buffer_free(&ioc->encoutput);
+    buffer_free(&ioc->rawinput);
+    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;
+
+    if (ioc->encinput.offset < 4096) {
+        size_t want = 4096 - ioc->encinput.offset;
+
+        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) {
+            return 0;
+        }
+        ioc->encinput.offset += ret;
+    }
+
+    if (ioc->payload_remain == 0) {
+        ret = qio_channel_websock_decode_header(ioc, errp);
+        if (ret < 0) {
+            return ret;
+        }
+        if (ret == 0) {
+            return 0;
+        }
+    }
+
+    ret = qio_channel_websock_decode_payload(ioc, errp);
+    if (ret < 0) {
+        return ret;
+    }
+    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);
+
+    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) {
+                return done;
+            } else {
+                return ret;
+            }
+        }
+        buffer_advance(&ioc->encoutput, ret);
+        done += ret;
+    }
+    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;
+
+    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) {
+            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) {
+        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) {
+        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;
+    }
+
+    if (cond) {
+        object_ref(OBJECT(ioc));
+        ioc->io_tag =
+            qio_channel_add_watch(ioc->master,
+                                  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,
+                                         Error **errp)
+{
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc);
+    size_t i;
+    ssize_t got = 0;
+    ssize_t ret;
+
+    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;
+        }
+    }
+
+    buffer_advance(&wioc->rawinput, got);
+    qio_channel_websock_set_watch(wioc);
+    return got;
+}
+
+
+static ssize_t qio_channel_websock_writev(QIOChannel *ioc,
+                                          const struct iovec *iov,
+                                          size_t niov,
+                                          int *fds,
+                                          size_t nfds,
+                                          Error **errp)
+{
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc);
+    size_t i;
+    ssize_t done = 0;
+    ssize_t ret;
+
+    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;
+        }
+
+        buffer_reserve(&wioc->rawoutput, want);
+        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 int qio_channel_websock_set_blocking(QIOChannel *ioc,
+                                            bool enabled,
+                                            Error **errp)
+{
+    QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc);
+
+    qio_channel_set_blocking(wioc->master, enabled, errp);
+    return 0;
+}
+
+static void qio_channel_websock_set_delay(QIOChannel *ioc,
+                                          bool enabled)
+{
+    QIOChannelWebsock *tioc = QIO_CHANNEL_WEBSOCK(ioc);
+
+    qio_channel_set_delay(tioc->master, enabled);
+}
+
+static void qio_channel_websock_set_cork(QIOChannel *ioc,
+                                         bool enabled)
+{
+    QIOChannelWebsock *tioc = QIO_CHANNEL_WEBSOCK(ioc);
+
+    qio_channel_set_cork(tioc->master, enabled);
+}
+
+static int qio_channel_websock_shutdown(QIOChannel *ioc,
+                                        QIOChannelShutdown how,
+                                        Error **errp)
+{
+    QIOChannelWebsock *tioc = QIO_CHANNEL_WEBSOCK(ioc);
+
+    return qio_channel_shutdown(tioc->master, how, errp);
+}
+
+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;
+    }
+
+    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;
+    }
+
+    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;
+    }
+
+    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;
+
+    source = g_source_new(&qio_channel_websock_source_funcs,
+                          sizeof(QIOChannelWebsockSource));
+    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_set_cork = qio_channel_websock_set_cork;
+    ioc_klass->io_set_delay = qio_channel_websock_set_delay;
+    ioc_klass->io_close = qio_channel_websock_close;
+    ioc_klass->io_shutdown = qio_channel_websock_shutdown;
+    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_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);