251 struct nm_desc {  struct
252 	struct nm_desc *self; /* point to self if netmap. */  argument
253 	int fd;
254 	void *mem;
255 	size_t memsize;
256 	int done_mmap;	/* set if mem is the result of mmap */
257 	struct netmap_if * const nifp;
258 	uint16_t first_tx_ring, last_tx_ring, cur_tx_ring;
259 	uint16_t first_rx_ring, last_rx_ring, cur_rx_ring;
260 	struct nmreq req;	/* also contains the nr_name = ifname */
261 	struct nm_pkthdr hdr;
293 #define P2NMD(p)		((const struct nm_desc *)(p))  argument