Fix spice-server/qemu channel version checks

When qemu creates a channel, reds.c contains code to check the
minor/major channel versions known to QEMU (ie the ones that were
current in spice-server when QEMU was compiled) and to compare these
versions against the current ones the currently installed spice-server
version.

According to kraxel [1], the rules for these interface numbers are:

"The purpose of the versions is exactly to avoid the need for a new
soname.  The rules are basically:

   (1) You add stuff to the interface, strictly append-only to not break
       binary compatibility.
   (2) You bump the minor version of the interface.
   (3) You check the minor version at runtime to figure whenever the
       added fields contain valid stuff or not.

An example is here (core interface, minor goes from 2 to 3, new
channel_event callback):

http://cgit.freedesktop.org/spice/spice/commit/?id=97f33fa86aa6edd25111b173dc0d9599ac29f879
"

The code currently refuses to create a channel if QEMU minor version is
less than the current spice-server version. This does not correspond
to the intended behaviour, this patch changes to fail is qemu was compiled
with a spice-server that is *newer* than the one currently installed. This
case is something we cannot support nicely.

[1] http://lists.freedesktop.org/archives/spice-devel/2011-July/004440.html

1 files changed, 8 insertions, 8 deletions

diff --git a/server/reds.c b/server/reds.c
index ca6cf4d..ee24e87 100644
--- a/server/reds.c
+++ b/server/reds.c
@@ -3270,7 +3270,7 @@ SPICE_GNUC_VISIBLE int spice_server_add_interface(SpiceServer *s,
     if (strcmp(interface->type, SPICE_INTERFACE_KEYBOARD) == 0) {
         red_printf("SPICE_INTERFACE_KEYBOARD");
         if (interface->major_version != SPICE_INTERFACE_KEYBOARD_MAJOR ||
-            interface->minor_version < SPICE_INTERFACE_KEYBOARD_MINOR) {
+            interface->minor_version > SPICE_INTERFACE_KEYBOARD_MINOR) {
             red_printf("unsupported keyboard interface");
             return -1;
         }
@@ -3280,7 +3280,7 @@ SPICE_GNUC_VISIBLE int spice_server_add_interface(SpiceServer *s,
     } else if (strcmp(interface->type, SPICE_INTERFACE_MOUSE) == 0) {
         red_printf("SPICE_INTERFACE_MOUSE");
         if (interface->major_version != SPICE_INTERFACE_MOUSE_MAJOR ||
-            interface->minor_version < SPICE_INTERFACE_MOUSE_MINOR) {
+            interface->minor_version > SPICE_INTERFACE_MOUSE_MINOR) {
             red_printf("unsupported mouse interface");
             return -1;
         }
@@ -3292,7 +3292,7 @@ SPICE_GNUC_VISIBLE int spice_server_add_interface(SpiceServer *s,
 
         red_printf("SPICE_INTERFACE_QXL");
         if (interface->major_version != SPICE_INTERFACE_QXL_MAJOR ||
-            interface->minor_version < SPICE_INTERFACE_QXL_MINOR) {
+            interface->minor_version > SPICE_INTERFACE_QXL_MINOR) {
             red_printf("unsupported qxl interface");
             return -1;
         }
@@ -3305,7 +3305,7 @@ SPICE_GNUC_VISIBLE int spice_server_add_interface(SpiceServer *s,
     } else if (strcmp(interface->type, SPICE_INTERFACE_TABLET) == 0) {
         red_printf("SPICE_INTERFACE_TABLET");
         if (interface->major_version != SPICE_INTERFACE_TABLET_MAJOR ||
-            interface->minor_version < SPICE_INTERFACE_TABLET_MINOR) {
+            interface->minor_version > SPICE_INTERFACE_TABLET_MINOR) {
             red_printf("unsupported tablet interface");
             return -1;
         }
@@ -3320,7 +3320,7 @@ SPICE_GNUC_VISIBLE int spice_server_add_interface(SpiceServer *s,
     } else if (strcmp(interface->type, SPICE_INTERFACE_PLAYBACK) == 0) {
         red_printf("SPICE_INTERFACE_PLAYBACK");
         if (interface->major_version != SPICE_INTERFACE_PLAYBACK_MAJOR ||
-            interface->minor_version < SPICE_INTERFACE_PLAYBACK_MINOR) {
+            interface->minor_version > SPICE_INTERFACE_PLAYBACK_MINOR) {
             red_printf("unsupported playback interface");
             return -1;
         }
@@ -3329,7 +3329,7 @@ SPICE_GNUC_VISIBLE int spice_server_add_interface(SpiceServer *s,
     } else if (strcmp(interface->type, SPICE_INTERFACE_RECORD) == 0) {
         red_printf("SPICE_INTERFACE_RECORD");
         if (interface->major_version != SPICE_INTERFACE_RECORD_MAJOR ||
-            interface->minor_version < SPICE_INTERFACE_RECORD_MINOR) {
+            interface->minor_version > SPICE_INTERFACE_RECORD_MINOR) {
             red_printf("unsupported record interface");
             return -1;
         }
@@ -3337,7 +3337,7 @@ SPICE_GNUC_VISIBLE int spice_server_add_interface(SpiceServer *s,
 
     } else if (strcmp(interface->type, SPICE_INTERFACE_CHAR_DEVICE) == 0) {
         if (interface->major_version != SPICE_INTERFACE_CHAR_DEVICE_MAJOR ||
-            interface->minor_version < SPICE_INTERFACE_CHAR_DEVICE_MINOR) {
+            interface->minor_version > SPICE_INTERFACE_CHAR_DEVICE_MINOR) {
             red_printf("unsupported char device interface");
             return -1;
         }
@@ -3352,7 +3352,7 @@ SPICE_GNUC_VISIBLE int spice_server_add_interface(SpiceServer *s,
             return -1;
         }
         if (interface->major_version != SPICE_INTERFACE_NET_WIRE_MAJOR ||
-            interface->minor_version < SPICE_INTERFACE_NET_WIRE_MINOR) {
+            interface->minor_version > SPICE_INTERFACE_NET_WIRE_MINOR) {
             red_printf("unsupported net wire interface");
             return -1;
         }