[Spice-devel] [PATCH spice-gtk] channel-inputs: Fix sending 00 scancodes to guests with scancode cap

[Hans de Goede]

The code for handling single key up / down events in spice-server is:
        SpiceMsgcKeyDown *key_down = (SpiceMsgcKeyDown *)buf;
        uint8_t *now = (uint8_t *)&key_down->code;
        uint8_t *end = now + sizeof(key_down->code);
        for (; now < end && *now; now++) {
            kbd_push_scan(keyboard, *now);
        }

Notice the *now, which makes sure that no scancodes with the value 0 get
send! But the new SPICE_MSGC_INPUTS_KEY_SCANCODE in the server does:

        uint8_t *code = (uint8_t *)buf;
        for (i = 0; i < size; i++) {
            kbd_push_scan(keyboard, code[i]);
        }

And thus will push any 0 bytes in the buffer. Resulting in these message
in the guest:

atkbd serio0: Unknown key pressed (translated set 2, code 0x0 on isa0060/serio0).
atkbd serio0: Use 'setkeycodes 00 <keycode>' to make it known.

Rather then making the server skip 0 bytes I believe it is better to just
make spice-gtk not send these in the first place, which is what this patch
does.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 gtk/channel-inputs.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/gtk/channel-inputs.c b/gtk/channel-inputs.c
index c907948..ee86dc2 100644
--- a/gtk/channel-inputs.c
+++ b/gtk/channel-inputs.c
@@ -537,12 +537,23 @@ void spice_inputs_key_press_and_release(SpiceInputsChannel *input_channel, guint
 
     if (spice_channel_test_capability(channel, SPICE_INPUTS_CAP_KEY_SCANCODE)) {
         SpiceMsgOut *msg;
-        guint16 *code;
+        guint16 code;
+        guint8 *buf;
 
         msg = spice_msg_out_new(channel, SPICE_MSGC_INPUTS_KEY_SCANCODE);
-        code = (guint16*)spice_marshaller_reserve_space(msg->marshaller, 2 * sizeof(guint16));
-        *code++ = spice_make_scancode(scancode, FALSE);
-        *code = spice_make_scancode(scancode, TRUE);
+        if (scancode < 0x100) {
+            buf = (guint8*)spice_marshaller_reserve_space(msg->marshaller, 2);
+            buf[0] = spice_make_scancode(scancode, FALSE);
+            buf[1] = spice_make_scancode(scancode, TRUE);
+        } else {
+            buf = (guint8*)spice_marshaller_reserve_space(msg->marshaller, 4);
+            code = spice_make_scancode(scancode, FALSE);
+            buf[0] = code & 0xff;
+            buf[1] = code >> 8;
+            code = spice_make_scancode(scancode, TRUE);
+            buf[2] = code & 0xff;
+            buf[3] = code >> 8;
+        }
         spice_msg_out_send(msg);
     } else {
         CHANNEL_DEBUG(channel, "The server doesn't support atomic press and release");
-- 
1.7.12.1