int sd_rtnl_message_route_set_dst_prefixlen(sd_rtnl_message *m, unsigned char prefixlen);
int sd_rtnl_message_route_set_scope(sd_rtnl_message *m, unsigned char scope);
+int sd_rtnl_message_route_get_family(sd_rtnl_message *m, int *family);
int sd_rtnl_message_append_string(sd_rtnl_message *m, unsigned short type, const char *data);
int sd_rtnl_message_append_u8(sd_rtnl_message *m, unsigned short type, uint8_t data);