+/* Prepending attributes. */
+void *nl_msg_push_unspec_uninit(struct ofpbuf *, uint16_t type, size_t);
+void nl_msg_push_unspec(struct ofpbuf *, uint16_t type, const void *, size_t);
+void nl_msg_push_flag(struct ofpbuf *, uint16_t type);
+void nl_msg_push_u8(struct ofpbuf *, uint16_t type, uint8_t value);
+void nl_msg_push_u16(struct ofpbuf *, uint16_t type, uint16_t value);
+void nl_msg_push_u32(struct ofpbuf *, uint16_t type, uint32_t value);
+void nl_msg_push_u64(struct ofpbuf *, uint16_t type, uint64_t value);
+void nl_msg_push_be16(struct ofpbuf *, uint16_t type, ovs_be16 value);
+void nl_msg_push_be32(struct ofpbuf *, uint16_t type, ovs_be32 value);
+void nl_msg_push_be64(struct ofpbuf *, uint16_t type, ovs_be64 value);
+void nl_msg_push_string(struct ofpbuf *, uint16_t type, const char *value);
+