Fix QEMU -vnc arg generation with raw IPv6 addresses

Since -vnc uses ':' to separate the address from the port, raw
IPv6 addresses need to be escaped like [addr]:port

* src/qemu/qemu_command.c: Escape raw IPv6 addresses with []
* tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.args,
  tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.xml: Tweak
  to test Ipv6 escaping
* docs/schemas/domain.rng: Allow Ipv6 addresses, or hostnames
  in <graphics> listen attributes

docs/schemas/domain.rng

@@ -1200,7 +1200,7 @@
               </optional>
               <optional>
                 <attribute name="listen">
-                  <ref name="addrIP"/>
+                  <ref name="addrIPorName"/>
                 </attribute>
               </optional>
             </group>
@@ -1247,7 +1247,7 @@
           </optional>
           <optional>
             <attribute name="listen">
-              <ref name="addrIP"/>
+              <ref name="addrIPorName"/>
             </attribute>
           </optional>
           <optional>
@@ -1383,7 +1383,7 @@
           </optional>
           <optional>
             <attribute name="listen">
-              <ref name="addrIP"/>
+              <ref name="addrIPorName"/>
             </attribute>
           </optional>
         </group>
@@ -2376,6 +2376,11 @@
       <param name="pattern">([0-2]?[0-9]?[0-9]\.){3}[0-2]?[0-9]?[0-9]</param>
     </data>
   </define>
+  <define name="addrIPorName">
+    <data type="string">
+      <param name="pattern">(([0-2]?[0-9]?[0-9]\.){3}[0-2]?[0-9]?[0-9])|(([0-9a-fA-F]+|:)+[0-9a-fA-F]+)|([a-zA-Z0-9_\.\+\-]*)</param>
+    </data>
+  </define>
   <define name="usbId">
     <data type="string">
       <param name="pattern">(0x)?[0-9a-fA-F]{1,4}</param>

src/qemu/qemu_command.c

@@ -3893,11 +3893,14 @@ qemuBuildCommandLine(virConnectPtr conn,
                               def->graphics[0]->data.vnc.socket);
 
         } else if (qemuCapsGet(qemuCaps, QEMU_CAPS_VNC_COLON)) {
-            if (def->graphics[0]->data.vnc.listenAddr)
-                virBufferAdd(&opt, def->graphics[0]->data.vnc.listenAddr, -1);
-            else if (driver->vncListen)
-                virBufferAdd(&opt, driver->vncListen, -1);
-
+            const char *addr = def->graphics[0]->data.vnc.listenAddr ?
+                def->graphics[0]->data.vnc.listenAddr :
+                driver->vncListen;
+            bool escapeAddr = strchr(addr, ':') != NULL;
+            if (escapeAddr)
+                virBufferAsprintf(&opt, "[%s]", addr);
+            else
+                virBufferAdd(&opt, addr, -1);
             virBufferAsprintf(&opt, ":%d",
                               def->graphics[0]->data.vnc.port - 5900);
 
@@ -5737,32 +5740,46 @@ virDomainDefPtr qemuParseCommandLine(virCapsPtr caps,
             vnc->type = VIR_DOMAIN_GRAPHICS_TYPE_VNC;
 
             if (STRPREFIX(val, "unix:")) {
+                /* -vnc unix:/some/big/path */
                 vnc->data.vnc.socket = strdup(val + 5);
                 if (!vnc->data.vnc.socket) {
                     VIR_FREE(vnc);
                     goto no_memory;
                 }
             } else {
-                tmp = strchr(val, ':');
-                if (tmp) {
-                    char *opts;
-                    if (virStrToLong_i(tmp+1, &opts, 10,
-                                       &vnc->data.vnc.port) < 0) {
-                        VIR_FREE(vnc);
-                        qemuReportError(VIR_ERR_INTERNAL_ERROR,
-                                        _("cannot parse VNC port '%s'"), tmp+1);
-                        goto error;
-                    }
+                /*
+                 * -vnc 127.0.0.1:4
+                 * -vnc [2001:1:2:3:4:5:1234:1234]:4
+                 * -vnc some.host.name:4
+                 */
+                char *opts;
+                const char *sep = ":";
+                if (val[0] == '[')
+                    sep = "]:";
+                tmp = strstr(val, sep);
+                if (!tmp) {
+                    VIR_FREE(vnc);
+                    qemuReportError(VIR_ERR_INTERNAL_ERROR,
+                                    _("missing VNC port number in '%s'"), val);
+                    goto error;
+                }
+                if (virStrToLong_i(tmp+strlen(sep), &opts, 10,
+                                   &vnc->data.vnc.port) < 0) {
+                    VIR_FREE(vnc);
+                    qemuReportError(VIR_ERR_INTERNAL_ERROR,
+                                    _("cannot parse VNC port '%s'"), tmp+1);
+                    goto error;
+                }
+                if (val[0] == '[')
+                    vnc->data.vnc.listenAddr = strndup(val+1, tmp-(val+1));
+                else
                     vnc->data.vnc.listenAddr = strndup(val, tmp-val);
-                    if (!vnc->data.vnc.listenAddr) {
-                        VIR_FREE(vnc);
-                        goto no_memory;
-                    }
-                    vnc->data.vnc.port += 5900;
-                    vnc->data.vnc.autoport = 0;
-                } else {
-                    vnc->data.vnc.autoport = 1;
+                if (!vnc->data.vnc.listenAddr) {
+                    VIR_FREE(vnc);
+                    goto no_memory;
                 }
+                vnc->data.vnc.port += 5900;
+                vnc->data.vnc.autoport = 0;
             }
 
             if (VIR_REALLOC_N(def->graphics, def->ngraphics+1) < 0) {

tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.args

 LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
 /usr/bin/qemu -S -M pc -m 214 -smp 1 -monitor unix:/tmp/test-monitor,server,\
 nowait -no-acpi -boot c -hda /dev/HostVG/QEMUGuest1 -net none -serial none \
--parallel none -usb -vnc 127.0.0.1:3
+-parallel none -usb -vnc [2001:1:2:3:4:5:1234:1234]:3

tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.xml

@@ -21,7 +21,7 @@
     </disk>
     <controller type='ide' index='0'/>
     <input type='mouse' bus='ps2'/>
-    <graphics type='vnc' port='5903' autoport='no' listen='127.0.0.1'/>
+    <graphics type='vnc' port='5903' autoport='no' listen='2001:1:2:3:4:5:1234:1234'/>
     <video>
       <model type='cirrus' vram='9216' heads='1'/>
     </video>