+void *eth_compose(struct ofpbuf *, const uint8_t eth_dst[ETH_ADDR_LEN],
+ const uint8_t eth_src[ETH_ADDR_LEN], uint16_t eth_type,
+ size_t size);
+void *snap_compose(struct ofpbuf *, const uint8_t eth_dst[ETH_ADDR_LEN],
+ const uint8_t eth_src[ETH_ADDR_LEN],
+ unsigned int oui, uint16_t snap_type, size_t size);
+