int sd_netlink_message_open_container_union(sd_netlink_message *m, unsigned short type, const char *key);
int sd_netlink_message_close_container(sd_netlink_message *m);
int sd_netlink_message_open_container_union(sd_netlink_message *m, unsigned short type, const char *key);
int sd_netlink_message_close_container(sd_netlink_message *m);
int sd_netlink_message_read_string(sd_netlink_message *m, unsigned short type, const char **data);
int sd_netlink_message_read_u8(sd_netlink_message *m, unsigned short type, uint8_t *data);
int sd_netlink_message_read_u16(sd_netlink_message *m, unsigned short type, uint16_t *data);
int sd_netlink_message_read_string(sd_netlink_message *m, unsigned short type, const char **data);
int sd_netlink_message_read_u8(sd_netlink_message *m, unsigned short type, uint8_t *data);
int sd_netlink_message_read_u16(sd_netlink_message *m, unsigned short type, uint16_t *data);