io: Reply to ping frames

Add an immediate ping reply (pong) to the outgoing stream when a ping
is received. Unsolicited pongs are ignored.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This commit is contained in:
Brandon Carpenter 2017-09-12 08:21:52 -07:00 committed by Daniel P. Berrange
parent 01af17fc00
commit 268a53f50d
2 changed files with 45 additions and 22 deletions

View File

@ -60,6 +60,7 @@ struct QIOChannelWebsock {
Buffer encoutput;
Buffer rawinput;
Buffer rawoutput;
Buffer ping_reply;
size_t payload_remain;
QIOChannelWebsockMask mask;
guint io_tag;

View File

@ -573,7 +573,8 @@ static gboolean qio_channel_websock_handshake_io(QIOChannel *ioc,
}
static void qio_channel_websock_encode(QIOChannelWebsock *ioc)
static void qio_channel_websock_encode_buffer(Buffer *output,
uint8_t opcode, Buffer *buffer)
{
size_t header_size;
union {
@ -581,33 +582,37 @@ static void qio_channel_websock_encode(QIOChannelWebsock *ioc)
QIOChannelWebsockHeader ws;
} header;
if (!ioc->rawoutput.offset) {
return;
}
header.ws.b0 = QIO_CHANNEL_WEBSOCK_HEADER_FIELD_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;
(opcode & QIO_CHANNEL_WEBSOCK_HEADER_FIELD_OPCODE);
if (buffer->offset < QIO_CHANNEL_WEBSOCK_PAYLOAD_LEN_THRESHOLD_7_BIT) {
header.ws.b1 = (uint8_t)buffer->offset;
header_size = QIO_CHANNEL_WEBSOCK_HEADER_LEN_7_BIT;
} else if (ioc->rawoutput.offset <
} else if (buffer->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.ws.u.s16.l16 = cpu_to_be16((uint16_t)buffer->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.ws.u.s64.l64 = cpu_to_be64(buffer->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_reserve(output, header_size + buffer->offset);
buffer_append(output, header.buf, header_size);
buffer_append(output, buffer->buffer, buffer->offset);
}
static void qio_channel_websock_encode(QIOChannelWebsock *ioc)
{
if (!ioc->rawoutput.offset) {
return;
}
qio_channel_websock_encode_buffer(
&ioc->encoutput, QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME,
&ioc->rawoutput);
buffer_reset(&ioc->rawoutput);
}
@ -652,7 +657,7 @@ static int qio_channel_websock_decode_header(QIOChannelWebsock *ioc,
/* Websocket frame sanity check:
* * Fragmentation is only supported for binary frames.
* * All frames sent by a client MUST be masked.
* * Only binary encoding is supported.
* * Only binary and ping/pong encoding is supported.
*/
if (!fin) {
if (opcode != QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME) {
@ -713,6 +718,11 @@ static int qio_channel_websock_decode_payload(QIOChannelWebsock *ioc,
* for purpose of unmasking, except at end of payload
*/
if (ioc->encinput.offset < ioc->payload_remain) {
/* Wait for the entire payload before processing control frames
* because the payload will most likely be echoed back. */
if (ioc->opcode & QIO_CHANNEL_WEBSOCK_CONTROL_OPCODE_MASK) {
return QIO_CHANNEL_ERR_BLOCK;
}
payload_len = ioc->encinput.offset - (ioc->encinput.offset % 4);
} else {
payload_len = ioc->payload_remain;
@ -735,13 +745,18 @@ static int qio_channel_websock_decode_payload(QIOChannelWebsock *ioc,
}
}
/* Drop the payload of ping/pong packets */
if (ioc->opcode == QIO_CHANNEL_WEBSOCK_OPCODE_BINARY_FRAME) {
if (payload_len) {
/* binary frames are passed on */
buffer_reserve(&ioc->rawinput, payload_len);
buffer_append(&ioc->rawinput, ioc->encinput.buffer, payload_len);
}
}
} else if (ioc->opcode == QIO_CHANNEL_WEBSOCK_OPCODE_PING) {
/* ping frames produce an immediate reply */
buffer_reset(&ioc->ping_reply);
qio_channel_websock_encode_buffer(
&ioc->ping_reply, QIO_CHANNEL_WEBSOCK_OPCODE_PONG, &ioc->encinput);
} /* pong frames are ignored */
if (payload_len) {
buffer_advance(&ioc->encinput, payload_len);
@ -799,6 +814,7 @@ static void qio_channel_websock_finalize(Object *obj)
buffer_free(&ioc->encoutput);
buffer_free(&ioc->rawinput);
buffer_free(&ioc->rawoutput);
buffer_free(&ioc->ping_reply);
object_unref(OBJECT(ioc->master));
if (ioc->io_tag) {
g_source_remove(ioc->io_tag);
@ -855,7 +871,13 @@ static ssize_t qio_channel_websock_write_wire(QIOChannelWebsock *ioc,
{
ssize_t ret;
ssize_t done = 0;
qio_channel_websock_encode(ioc);
/* ping replies take priority over binary data */
if (!ioc->ping_reply.offset) {
qio_channel_websock_encode(ioc);
} else if (!ioc->encoutput.offset) {
buffer_move_empty(&ioc->encoutput, &ioc->ping_reply);
}
while (ioc->encoutput.offset > 0) {
ret = qio_channel_write(ioc->master,
@ -930,7 +952,7 @@ static void qio_channel_websock_set_watch(QIOChannelWebsock *ioc)
return;
}
if (ioc->encoutput.offset) {
if (ioc->encoutput.offset || ioc->ping_reply.offset) {
cond |= G_IO_OUT;
}
if (ioc->encinput.offset < QIO_CHANNEL_WEBSOCK_MAX_BUFFER &&