int sd_rtnl_message_append_u16(sd_rtnl_message *m, unsigned short type, uint16_t data);
int sd_rtnl_message_append_u32(sd_rtnl_message *m, unsigned short type, uint32_t data);
int sd_rtnl_message_append_in_addr(sd_rtnl_message *m, unsigned short type, const struct in_addr *data);
int sd_rtnl_message_append_u16(sd_rtnl_message *m, unsigned short type, uint16_t data);
int sd_rtnl_message_append_u32(sd_rtnl_message *m, unsigned short type, uint32_t data);
int sd_rtnl_message_append_in_addr(sd_rtnl_message *m, unsigned short type, const struct in_addr *data);