conf: Check whether migration_address is localhost

When enabling the migration_address option, by default it is
set to "127.0.0.1", but it's not a valid address for migration.
so we should add verification and set the default migration_address
to "0.0.0.0".
Signed-off-by: NChen Fan <chen.fan.fnst@cn.fujitsu.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu.conf

@@ -467,7 +467,7 @@
 
 # Override the listen address for all incoming migrations. Defaults to
 # 0.0.0.0, or :: if both host and qemu are capable of IPv6.
-#migration_address = "127.0.0.1"
+#migration_address = "0.0.0.0"
 
 
 # The default hostname or IP address which will be used by a migration

src/qemu/qemu_conf.c

@@ -719,6 +719,16 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg,
     }
 
     GET_VALUE_STR("migration_address", cfg->migrationAddress);
+    virStringStripIPv6Brackets(cfg->migrationAddress);
+    if (cfg->migrationAddress &&
+        (STRPREFIX(cfg->migrationAddress, "localhost") ||
+         virSocketAddrIsNumericLocalhost(cfg->migrationAddress))) {
+        virReportError(VIR_ERR_CONF_SYNTAX,
+                       _("migration_address must not be the address of"
+                         " the local machine: %s"),
+                       cfg->migrationAddress);
+        goto cleanup;
+    }
 
     GET_VALUE_BOOL("log_timestamp", cfg->logTimestamp);
 

src/qemu/test_libvirtd_qemu.aug.in

@@ -69,7 +69,7 @@ module Test_libvirtd_qemu =
 { "keepalive_interval" = "5" }
 { "keepalive_count" = "5" }
 { "seccomp_sandbox" = "1" }
-{ "migration_address" = "127.0.0.1" }
+{ "migration_address" = "0.0.0.0" }
 { "migration_host" = "host.example.com" }
 { "migration_port_min" = "49152" }
 { "migration_port_max" = "49215" }