Extend graphics event to include UNIX socket

Not all VNC/SPICE servers use a TCP socket for their connections.
It is possible to configure a UNIX socket server. The graphics
event must thus include a UNIX socket address type.

* include/libvirt/libvirt.h.in: Add UNIX socket address type
  for graphics event
* src/qemu/qemu_monitor_json.c: Add 'unix' string to address
  type enum

include/libvirt/libvirt.h.in

@@ -2894,6 +2894,7 @@ typedef enum {
 typedef enum {
     VIR_DOMAIN_EVENT_GRAPHICS_ADDRESS_IPV4,  /* IPv4 address */
     VIR_DOMAIN_EVENT_GRAPHICS_ADDRESS_IPV6,  /* IPv6 address */
+    VIR_DOMAIN_EVENT_GRAPHICS_ADDRESS_UNIX,  /* UNIX socket path */
 } virDomainEventGraphicsAddressType;
 
 
@@ -2905,8 +2906,8 @@ typedef enum {
  */
 struct _virDomainEventGraphicsAddress {
     int family;               /* Address family, virDomainEventGraphicsAddressType */
-    const char *node;         /* Address of node (eg IP address) */
-    const char *service;      /* Service name/number (eg TCP port) */
+    const char *node;         /* Address of node (eg IP address, or UNIX path) */
+    const char *service;      /* Service name/number (eg TCP port, or NULL) */
 };
 typedef struct _virDomainEventGraphicsAddress virDomainEventGraphicsAddress;
 typedef virDomainEventGraphicsAddress *virDomainEventGraphicsAddressPtr;

src/qemu/qemu_monitor_json.c

@@ -619,8 +619,8 @@ static void qemuMonitorJSONHandleIOError(qemuMonitorPtr mon, virJSONValuePtr dat
 
 
 VIR_ENUM_DECL(qemuMonitorGraphicsAddressFamily)
-VIR_ENUM_IMPL(qemuMonitorGraphicsAddressFamily, VIR_DOMAIN_EVENT_GRAPHICS_ADDRESS_IPV6 + 1,
-              "ipv4", "ipv6");
+VIR_ENUM_IMPL(qemuMonitorGraphicsAddressFamily, VIR_DOMAIN_EVENT_GRAPHICS_ADDRESS_UNIX + 1,
+              "ipv4", "ipv6", "unix");
 
 static void qemuMonitorJSONHandleVNC(qemuMonitorPtr mon, virJSONValuePtr data, int phase)
 {