[Spice-devel] [PATCH] server: release all pressed keys on client disconnect

[Marc-André Lureau]

Releasing modifiers keys unconditionally on disconnect leads to
unexpected guest wakeups. To improve the situation, the server can
release only the pressed keys, which will prevent the wakeup in most
cases.

Furthermore, it's not sufficient to release only the modifiers keys.
Any key should be released on client disconnect to avoid sticky key
press across connections.

https://bugzilla.redhat.com/show_bug.cgi?id=871240
---
 server/inputs_channel.c | 42 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 35 insertions(+), 7 deletions(-)

diff --git a/server/inputs_channel.c b/server/inputs_channel.c
index 931dac1..bda525a 100644
--- a/server/inputs_channel.c
+++ b/server/inputs_channel.c
@@ -27,6 +27,7 @@
 #include <spice/macros.h>
 #include <spice/vd_agent.h>
 #include <spice/protocol.h>
+#include <stdbool.h>
 
 #include "common/marshaller.h"
 #include "common/messages.h"
@@ -53,7 +54,11 @@
     (4096 + (REDS_AGENT_WINDOW_SIZE + REDS_NUM_INTERNAL_AGENT_MESSAGES) * SPICE_AGENT_MAX_DATA_SIZE)
 
 struct SpiceKbdState {
-    int dummy;
+    bool push_ext;
+
+    /* track key press state */
+    bool key[0x7f];
+    bool key_ext[0x7f];
 };
 
 struct SpiceMouseState {
@@ -221,6 +226,16 @@ static void kbd_push_scan(SpiceKbdInstance *sin, uint8_t scan)
         return;
     }
     sif = SPICE_CONTAINEROF(sin->base.sif, SpiceKbdInterface, base);
+
+    /* track XT scan code set 1 key state */
+    if (scan == 0xe0) {
+        sin->st->push_ext = TRUE;
+    } else {
+        bool *state = sin->st->push_ext ? sin->st->key : sin->st->key_ext;
+        sin->st->push_ext = FALSE;
+        state[scan & 0x7f] = !(scan & 0x80);
+    }
+
     sif->push_scan_freg(sin, scan);
 }
 
@@ -466,12 +481,25 @@ static int inputs_channel_handle_parsed(RedChannelClient *rcc, uint32_t size, ui
 
 static void inputs_relase_keys(void)
 {
-    kbd_push_scan(keyboard, 0x2a | 0x80); //LSHIFT
-    kbd_push_scan(keyboard, 0x36 | 0x80); //RSHIFT
-    kbd_push_scan(keyboard, 0xe0); kbd_push_scan(keyboard, 0x1d | 0x80); //RCTRL
-    kbd_push_scan(keyboard, 0x1d | 0x80); //LCTRL
-    kbd_push_scan(keyboard, 0xe0); kbd_push_scan(keyboard, 0x38 | 0x80); //RALT
-    kbd_push_scan(keyboard, 0x38 | 0x80); //LALT
+    int i;
+    SpiceKbdState *st = keyboard->st;
+
+    for (i = 0; i < SPICE_N_ELEMENTS(st->key); i++) {
+        if (!st->key[i])
+            continue;
+
+        st->key[i] = FALSE;
+        kbd_push_scan(keyboard, i | 0x80);
+    }
+
+    for (i = 0; i < SPICE_N_ELEMENTS(st->key_ext); i++) {
+        if (!st->key_ext[i])
+            continue;
+
+        st->key_ext[i] = FALSE;
+        kbd_push_scan(keyboard, 0xe0);
+        kbd_push_scan(keyboard, i | 0x80);
+    }
 }
 
 static void inputs_channel_on_disconnect(RedChannelClient *rcc)
-- 
1.8.3.1