AVAHI_CHECK_VALIDITY_RETURN_NULL(s, AVAHI_FLAGS_VALID(flags, AVAHI_PUBLISH_USE_WIDE_AREA|AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS);
AVAHI_CHECK_VALIDITY_RETURN_NULL(s, type == AVAHI_DNS_SERVER_UPDATE || type == AVAHI_DNS_SERVER_RESOLVE, AVAHI_ERR_INVALID_FLAGS);
AVAHI_CHECK_VALIDITY_RETURN_NULL(s, port != 0, AVAHI_ERR_INVALID_PORT);
AVAHI_CHECK_VALIDITY_RETURN_NULL(s, AVAHI_FLAGS_VALID(flags, AVAHI_PUBLISH_USE_WIDE_AREA|AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS);
AVAHI_CHECK_VALIDITY_RETURN_NULL(s, type == AVAHI_DNS_SERVER_UPDATE || type == AVAHI_DNS_SERVER_RESOLVE, AVAHI_ERR_INVALID_FLAGS);
AVAHI_CHECK_VALIDITY_RETURN_NULL(s, port != 0, AVAHI_ERR_INVALID_PORT);