struct pktbuf *pktbuf_create(void);
void pktbuf_destroy(struct pktbuf *);
uint32_t pktbuf_save(struct pktbuf *, struct ofpbuf *buffer, uint16_t in_port);
+uint32_t pktbuf_get_null(void);
int pktbuf_retrieve(struct pktbuf *, uint32_t id, struct ofpbuf **bufferp,
uint16_t *in_port);
void pktbuf_discard(struct pktbuf *, uint32_t id);