io: fix decoding when multiple websockets frames arrive at once
PATCH 1/1 io: fix decoding when multiple websockets frames arrive at once
The qio_channel_websock_read_wire() method will read upto 4096 bytes off the socket and then decode the websockets header and payload. The code was only decoding a single websockets frame, even if the buffered data contained multiple frames. This meant that decoding of subsequent frames was delayed until further input arrived on the socket. This backlog of delayed frames gets worse & worse over time.
Symptom was that when connecting to the VNC server via the built-in websockets server, mouse/keyboard interaction would start out fine, but slowly get more & more delayed until it was unusable.
--- io/channel-websock.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-)
io/channel-websock.c +14 -14
@@ -570,21 +570,24 @@ static ssize_t qio_channel_websock_read_wire(QIOChannelWebsock *ioc, ioc->encinput.offset += ret; } -if (ioc->payload_remain ==0 ) { - ret =qio_channel_websock_decode_header (ioc, errp); +while (ioc->encinput.offset !=0 ) { +if (ioc->payload_remain ==0 ) { + ret =qio_channel_websock_decode_header (ioc, errp); +if (ret <0 ) { +return ret; + } +if (ret ==0 ) { + ioc->io_eof = TRUE; +break ; + } + } + + ret =qio_channel_websock_decode_payload (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; +return 1 ; }
@@ -642,9 +645,6 @@ static gboolean qio_channel_websock_flush(QIOChannel *ioc,if (ret <0 ) { goto cleanup; } -if (ret ==0 ) { - wioc->io_eof = TRUE; - } } cleanup:
Signature · 1 line
2.9.3
Quoted 1 line · Daniel P. Berrange
The
qio_channel_websock_read_wire()method will read upto 4096
s/upto/up to/
Quoted 12 lines
bytes off the socket and then decode the websockets header and payload. The code was only decoding a single websockets frame, even if the buffered data contained multiple frames. This meant that decoding of subsequent frames was delayed until further input arrived on the socket. This backlog of delayed frames gets worse & worse over time.
Symptom was that when connecting to the VNC server via the built-in websockets server, mouse/keyboard interaction would start out fine, but slowly get more & more delayed until it was unusable.
Quoted 5 lines
Signed-off-by Daniel P. Berrange <[email protected]>--- io/channel-websock.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-)
Signature · 2 lines
Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org