pkthdr
char *pkthdr, tmp[TCPPKTHDRSIZE]; /* is this too large for the stack? */
pkthdr = &tmp[0];
m_copydata(m0, 0, TCPPKTHDRSIZE, pkthdr);
pkthdr = mtod(m0, char *);
ip = (struct ip *)(pkthdr + ETHER_HDR_LEN +
ip = (struct ip *)(pkthdr + ETHER_HDR_LEN);
ip = (struct ip *)(pkthdr + ETHER_HDR_LEN);
struct pkthdr MH_pkthdr; \
STAILQ_ENTRY(pkthdr) next;
typedef struct pkthdr pkthdr_t;
STAILQ_HEAD(pktlist, pkthdr);