Fix SPICE seamless migration hostname

The SPICE seamless migration process requires data to be passed
back from the target host, to the source host via a cookie.
The cookie includes the target host's hostname, but this was not
stored, merely validated. This patch explicitly records the
remote hostname after parsing the cookie, and uses it when
initiating the SPICE migration

* qemu/qemu_migration.c: Fix SPICE seamless migration hostname

src/qemu/qemu_migration.c

@@ -79,8 +79,10 @@ struct _qemuMigrationCookie {
     int flagsMandatory;
 
     /* Host properties */
-    unsigned char hostuuid[VIR_UUID_BUFLEN];
-    char *hostname;
+    unsigned char localHostuuid[VIR_UUID_BUFLEN];
+    unsigned char remoteHostuuid[VIR_UUID_BUFLEN];
+    char *localHostname;
+    char *remoteHostname;
 
     /* Guest properties */
     unsigned char uuid[VIR_UUID_BUFLEN];
@@ -108,7 +110,8 @@ static void qemuMigrationCookieFree(qemuMigrationCookiePtr mig)
     if (mig->flags & QEMU_MIGRATION_COOKIE_GRAPHICS)
         qemuMigrationCookieGraphicsFree(mig->graphics);
 
-    VIR_FREE(mig->hostname);
+    VIR_FREE(mig->localHostname);
+    VIR_FREE(mig->remoteHostname);
     VIR_FREE(mig->name);
     VIR_FREE(mig);
 }
@@ -233,9 +236,9 @@ qemuMigrationCookieNew(virDomainObjPtr dom)
         goto no_memory;
     memcpy(mig->uuid, dom->def->uuid, VIR_UUID_BUFLEN);
 
-    if (!(mig->hostname = virGetHostname(NULL)))
+    if (!(mig->localHostname = virGetHostname(NULL)))
         goto no_memory;
-    if (virGetHostUUID(mig->hostuuid) < 0) {
+    if (virGetHostUUID(mig->localHostuuid) < 0) {
         qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                         _("Unable to obtain host UUID"));
         goto error;
@@ -301,12 +304,12 @@ static void qemuMigrationCookieXMLFormat(virBufferPtr buf,
     int i;
 
     virUUIDFormat(mig->uuid, uuidstr);
-    virUUIDFormat(mig->hostuuid, hostuuidstr);
+    virUUIDFormat(mig->localHostuuid, hostuuidstr);
 
     virBufferAsprintf(buf, "<qemu-migration>\n");
     virBufferEscapeString(buf, "  <name>%s</name>\n", mig->name);
     virBufferAsprintf(buf, "  <uuid>%s</uuid>\n", uuidstr);
-    virBufferEscapeString(buf, "  <hostname>%s</hostname>\n", mig->hostname);
+    virBufferEscapeString(buf, "  <hostname>%s</hostname>\n", mig->localHostname);
     virBufferAsprintf(buf, "  <hostuuid>%s</hostuuid>\n", hostuuidstr);
 
     for (i = 0 ; i < QEMU_MIGRATION_COOKIE_FLAG_LAST ; i++) {
@@ -434,26 +437,29 @@ qemuMigrationCookieXMLParse(qemuMigrationCookiePtr mig,
     VIR_FREE(tmp);
 
     /* Check & forbid "localhost" migration */
-    if (!(tmp = virXPathString("string(./hostname[1])", ctxt))) {
+    if (!(mig->remoteHostname = virXPathString("string(./hostname[1])", ctxt))) {
         qemuReportError(VIR_ERR_INTERNAL_ERROR,
                         "%s", _("missing hostname element in migration data"));
         goto error;
     }
-    if (STREQ(tmp, mig->hostname)) {
+    if (STREQ(mig->remoteHostname, mig->localHostname)) {
         qemuReportError(VIR_ERR_INTERNAL_ERROR,
                         _("Attempt to migrate guest to the same host %s"),
-                        tmp);
+                        mig->remoteHostname);
         goto error;
     }
-    VIR_FREE(tmp);
 
     if (!(tmp = virXPathString("string(./hostuuid[1])", ctxt))) {
         qemuReportError(VIR_ERR_INTERNAL_ERROR,
                         "%s", _("missing hostuuid element in migration data"));
         goto error;
     }
-    virUUIDFormat(mig->hostuuid, uuidstr);
-    if (STREQ(tmp, uuidstr)) {
+    if (virUUIDParse(tmp, mig->remoteHostuuid) < 0) {
+        qemuReportError(VIR_ERR_INTERNAL_ERROR,
+                        "%s", _("malformed hostuuid element in migration data"));
+        goto error;
+    }
+    if (memcmp(mig->remoteHostuuid, mig->localHostuuid, VIR_UUID_BUFLEN) == 0) {
         qemuReportError(VIR_ERR_INTERNAL_ERROR,
                         _("Attempt to migrate guest to the same host %s"),
                         tmp);
@@ -851,7 +857,7 @@ qemuDomainMigrateGraphicsRelocate(struct qemud_driver *driver,
     qemuDomainObjEnterMonitorWithDriver(driver, vm);
     ret = qemuMonitorGraphicsRelocate(priv->mon,
                                       cookie->graphics->type,
-                                      cookie->hostname,
+                                      cookie->remoteHostname,
                                       cookie->graphics->port,
                                       cookie->graphics->tlsPort,
                                       cookie->graphics->tlsSubject);