[Spice-devel] [PATCH spice-server v2 1/2] stream-device: handle cursor from device
Frediano Ziglio
fziglio at redhat.com
Wed Feb 21 15:29:41 UTC 2018
>
> I'm late to the party, but a one-line commit log for a patch adding 160
> lines of code is *not* acceptable.
>
> Christophe
>
Yes, was a mistake.
Frediano
> On Fri, Feb 09, 2018 at 09:10:48AM +0000, Frediano Ziglio wrote:
> > Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> > ---
> > server/stream-device.c | 169
> > +++++++++++++++++++++++++++++++++++++++++++++++--
> > 1 file changed, 162 insertions(+), 7 deletions(-)
> >
> > Changes since v1:
> > - add some comments with some implementation explanation;
> > - better computation of max cursor size.
> >
> > diff --git a/server/stream-device.c b/server/stream-device.c
> > index 735f2933..a5606d6a 100644
> > --- a/server/stream-device.c
> > +++ b/server/stream-device.c
> > @@ -23,6 +23,7 @@
> >
> > #include "char-device.h"
> > #include "stream-channel.h"
> > +#include "cursor-channel.h"
> > #include "reds.h"
> >
> > #define TYPE_STREAM_DEVICE stream_device_get_type()
> > @@ -45,13 +46,16 @@ struct StreamDevice {
> > union {
> > StreamMsgFormat format;
> > StreamMsgCapabilities capabilities;
> > + StreamMsgCursorSet cursor_set;
> > uint8_t buf[STREAM_MSG_CAPABILITIES_MAX_BYTES];
> > - } msg;
> > + } *msg;
> > uint32_t msg_pos;
> > + uint32_t msg_len;
> > bool has_error;
> > bool opened;
> > bool flow_stopped;
> > StreamChannel *stream_channel;
> > + CursorChannel *cursor_channel;
> > };
> >
> > struct StreamDeviceClass {
> > @@ -66,7 +70,7 @@ G_DEFINE_TYPE(StreamDevice, stream_device,
> > RED_TYPE_CHAR_DEVICE)
> > typedef bool StreamMsgHandler(StreamDevice *dev, SpiceCharDeviceInstance
> > *sin)
> > SPICE_GNUC_WARN_UNUSED_RESULT;
> >
> > -static StreamMsgHandler handle_msg_format, handle_msg_data;
> > +static StreamMsgHandler handle_msg_format, handle_msg_data,
> > handle_msg_cursor_set;
> >
> > static bool handle_msg_invalid(StreamDevice *dev, SpiceCharDeviceInstance
> > *sin,
> > const char *error_msg)
> > SPICE_GNUC_WARN_UNUSED_RESULT;
> > @@ -108,6 +112,16 @@ stream_device_read_msg_from_dev(RedCharDevice *self,
> > SpiceCharDeviceInstance *si
> > dev->hdr.type = GUINT16_FROM_LE(dev->hdr.type);
> > dev->hdr.size = GUINT32_FROM_LE(dev->hdr.size);
> > dev->msg_pos = 0;
> > + // reallocate to the minimum.
> > + // Currently the only message that requires resizing is
> > + // the cursor shape which is not expected to be sent so
> > + // often.
> > + // Avoid to use dev->hdr.size as this allows easily DoS
> > + // against the server.
> > + if (dev->msg_len > sizeof(*dev->msg)) {
> > + dev->msg = g_realloc(dev->msg, sizeof(*dev->msg));
> > + dev->msg_len = sizeof(*dev->msg);
> > + }
> > }
> > }
> >
> > @@ -122,6 +136,9 @@ stream_device_read_msg_from_dev(RedCharDevice *self,
> > SpiceCharDeviceInstance *si
> > case STREAM_TYPE_DATA:
> > handled = handle_msg_data(dev, sin);
> > break;
> > + case STREAM_TYPE_CURSOR_SET:
> > + handled = handle_msg_cursor_set(dev, sin);
> > + break;
> > case STREAM_TYPE_CAPABILITIES:
> > /* FIXME */
> > default:
> > @@ -194,7 +211,7 @@ handle_msg_format(StreamDevice *dev,
> > SpiceCharDeviceInstance *sin)
> > spice_assert(dev->hdr.type == STREAM_TYPE_FORMAT);
> > }
> >
> > - int n = sif->read(sin, dev->msg.buf + dev->msg_pos,
> > sizeof(StreamMsgFormat) - dev->msg_pos);
> > + int n = sif->read(sin, dev->msg->buf + dev->msg_pos,
> > sizeof(StreamMsgFormat) - dev->msg_pos);
> > if (n < 0) {
> > return handle_msg_invalid(dev, sin, NULL);
> > }
> > @@ -205,9 +222,9 @@ handle_msg_format(StreamDevice *dev,
> > SpiceCharDeviceInstance *sin)
> > return false;
> > }
> >
> > - dev->msg.format.width = GUINT32_FROM_LE(dev->msg.format.width);
> > - dev->msg.format.height = GUINT32_FROM_LE(dev->msg.format.height);
> > - stream_channel_change_format(dev->stream_channel, &dev->msg.format);
> > + dev->msg->format.width = GUINT32_FROM_LE(dev->msg->format.width);
> > + dev->msg->format.height = GUINT32_FROM_LE(dev->msg->format.height);
> > + stream_channel_change_format(dev->stream_channel, &dev->msg->format);
> > return true;
> > }
> >
> > @@ -238,6 +255,116 @@ handle_msg_data(StreamDevice *dev,
> > SpiceCharDeviceInstance *sin)
> > return dev->hdr.size == 0;
> > }
> >
> > +/*
> > + * Returns number of bits required for a pixel of a given cursor type.
> > + *
> > + * Take into account mask bits.
> > + * Returns 0 on error.
> > + */
> > +static unsigned int
> > +get_cursor_type_bits(unsigned int cursor_type)
> > +{
> > + switch (cursor_type) {
> > + case SPICE_CURSOR_TYPE_ALPHA:
> > + // RGBA
> > + return 32;
> > + case SPICE_CURSOR_TYPE_COLOR24:
> > + // RGB + bitmask
> > + return 24 + 1;
> > + case SPICE_CURSOR_TYPE_COLOR32:
> > + // RGBx + bitmask
> > + return 32 + 1;
> > + default:
> > + return 0;
> > + }
> > +}
> > +
> > +static RedCursorCmd *
> > +stream_msg_cursor_set_to_cursor_cmd(const StreamMsgCursorSet *msg, size_t
> > msg_size)
> > +{
> > + RedCursorCmd *cmd = g_new0(RedCursorCmd, 1);
> > + cmd->type = QXL_CURSOR_SET;
> > + cmd->u.set.position.x = 0; // TODO
> > + cmd->u.set.position.y = 0; // TODO
> > + cmd->u.set.visible = 1; // TODO
> > + SpiceCursor *cursor = &cmd->u.set.shape;
> > + cursor->header.unique = 0;
> > + cursor->header.type = msg->type;
> > + cursor->header.width = GUINT16_FROM_LE(msg->width);
> > + cursor->header.height = GUINT16_FROM_LE(msg->height);
> > + cursor->header.hot_spot_x = GUINT16_FROM_LE(msg->hot_spot_x);
> > + cursor->header.hot_spot_y = GUINT16_FROM_LE(msg->hot_spot_y);
> > +
> > + /* Limit cursor size to prevent DoS */
> > + if (cursor->header.width > STREAM_MSG_CURSOR_SET_MAX_WIDTH ||
> > + cursor->header.height > STREAM_MSG_CURSOR_SET_MAX_HEIGHT) {
> > + g_free(cmd);
> > + return NULL;
> > + }
> > +
> > + const unsigned int cursor_bits =
> > get_cursor_type_bits(cursor->header.type);
> > + if (cursor_bits == 0) {
> > + g_free(cmd);
> > + return NULL;
> > + }
> > +
> > + /* Check that enough data has been sent for the cursor.
> > + * Note that these computations can't overflow due to sizes checks
> > + * above. */
> > + size_t size_required = cursor->header.width * cursor->header.height;
> > + size_required = SPICE_ALIGN(size_required * cursor_bits, 8) / 8u;
> > + if (msg_size < sizeof(StreamMsgCursorSet) + size_required) {
> > + g_free(cmd);
> > + return NULL;
> > + }
> > + cursor->data_size = size_required;
> > + cursor->data = spice_memdup(msg->data, size_required);
> > + return cmd;
> > +}
> > +
> > +static bool
> > +handle_msg_cursor_set(StreamDevice *dev, SpiceCharDeviceInstance *sin)
> > +{
> > + // maximum size taking into account 32 bit image with bitmask
> > + const unsigned int max_cursor_set_size =
> > + (STREAM_MSG_CURSOR_SET_MAX_WIDTH * 4 +
> > (STREAM_MSG_CURSOR_SET_MAX_WIDTH + 7)/8)
> > + * STREAM_MSG_CURSOR_SET_MAX_HEIGHT;
> > +
> > + SpiceCharDeviceInterface *sif = spice_char_device_get_interface(sin);
> > +
> > + if (dev->hdr.size < sizeof(StreamMsgCursorSet)) {
> > + return handle_msg_invalid(dev, sin, NULL);
> > + }
> > + if (dev->hdr.size > max_cursor_set_size) {
> > + // we could skip the message but on the other end the client
> > + // is buggy in any case
> > + return handle_msg_invalid(dev, sin, "Cursor sent is too big");
> > + }
> > +
> > + // read part of the message till we get all
> > + if (dev->msg_len < dev->hdr.size) {
> > + dev->msg = g_realloc(dev->msg, dev->hdr.size);
> > + dev->msg_len = dev->hdr.size;
> > + }
> > + int n = sif->read(sin, dev->msg->buf + dev->msg_pos, dev->hdr.size -
> > dev->msg_pos);
> > + if (n <= 0) {
> > + return false;
> > + }
> > + dev->msg_pos += n;
> > + if (dev->msg_pos != dev->hdr.size) {
> > + return false;
> > + }
> > +
> > + // transform the message to a cursor command and process it
> > + RedCursorCmd *cmd =
> > stream_msg_cursor_set_to_cursor_cmd(&dev->msg->cursor_set, dev->msg_pos);
> > + if (!cmd) {
> > + return handle_msg_invalid(dev, sin, NULL);
> > + }
> > + cursor_channel_process_cmd(dev->cursor_channel, cmd);
> > +
> > + return true;
> > +}
> > +
> > static void
> > stream_device_send_msg_to_client(RedCharDevice *self, RedPipeItem *msg,
> > RedClient *client)
> > {
> > @@ -335,6 +462,22 @@ stream_device_dispose(GObject *object)
> > red_channel_destroy(RED_CHANNEL(dev->stream_channel));
> > dev->stream_channel = NULL;
> > }
> > + if (dev->cursor_channel) {
> > + // close all current connections and drop the reference
> > + red_channel_destroy(RED_CHANNEL(dev->cursor_channel));
> > + dev->cursor_channel = NULL;
> > + }
> > +}
> > +
> > +static void
> > +stream_device_finalize(GObject *object)
> > +{
> > + StreamDevice *dev = STREAM_DEVICE(object);
> > +
> > + g_free(dev->msg);
> > + dev->msg = NULL;
> > + dev->msg_len = 0;
> > + dev->msg_pos = 0;
> > }
> >
> > static void
> > @@ -345,13 +488,22 @@ allocate_channels(StreamDevice *dev)
> > }
> >
> > SpiceServer* reds = red_char_device_get_server(RED_CHAR_DEVICE(dev));
> > + SpiceCoreInterfaceInternal* core = reds_get_core_interface(reds);
> >
> > int id = reds_get_free_channel_id(reds, SPICE_CHANNEL_DISPLAY);
> > g_return_if_fail(id >= 0);
> >
> > StreamChannel *stream_channel = stream_channel_new(reds, id);
> >
> > + CursorChannel *cursor_channel = cursor_channel_new(reds, id, core);
> > + ClientCbs client_cbs = { NULL, };
> > + client_cbs.connect = (channel_client_connect_proc)
> > cursor_channel_connect;
> > + client_cbs.migrate = cursor_channel_client_migrate;
> > + red_channel_register_client_cbs(RED_CHANNEL(cursor_channel),
> > &client_cbs, NULL);
> > + reds_register_channel(reds, RED_CHANNEL(cursor_channel));
> > +
> > dev->stream_channel = stream_channel;
> > + dev->cursor_channel = cursor_channel;
> >
> > stream_channel_register_start_cb(stream_channel,
> > stream_device_stream_start, dev);
> > stream_channel_register_queue_stat_cb(stream_channel,
> > stream_device_stream_queue_stat, dev);
> > @@ -413,6 +565,7 @@ stream_device_class_init(StreamDeviceClass *klass)
> > RedCharDeviceClass *char_dev_class = RED_CHAR_DEVICE_CLASS(klass);
> >
> > object_class->dispose = stream_device_dispose;
> > + object_class->finalize = stream_device_finalize;
> >
> > char_dev_class->read_one_msg_from_device =
> > stream_device_read_msg_from_dev;
> > char_dev_class->send_msg_to_client = stream_device_send_msg_to_client;
> > @@ -422,8 +575,10 @@ stream_device_class_init(StreamDeviceClass *klass)
> > }
> >
> > static void
> > -stream_device_init(StreamDevice *self)
> > +stream_device_init(StreamDevice *dev)
> > {
> > + dev->msg = g_malloc(sizeof(*dev->msg));
> > + dev->msg_len = sizeof(*dev->msg);
> > }
> >
> > static StreamDevice *
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