+ u_char if_type; /* ethernet, tokenring, etc */
+ u_char if_addrlen; /* media address length */
+ u_char if_hdrlen; /* media header length */
+ u_char if_index; /* numeric abbreviation for this if */
+/* more statistics here to avoid recompiling netstat */
+ struct timeval if_lastchange; /* last updated */
+ int if_ibytes; /* total number of octets received */
+ int if_obytes; /* total number of octets sent */
+ int if_imcasts; /* packets received via multicast */
+ int if_omcasts; /* packets sent via multicast */
+ int if_iqdrops; /* dropped on input, this interface */
+ int if_noproto; /* destined for unsupported protocol */
+ int if_baudrate; /* linespeed */
+};
+
+#define IFF_UP 0x1 /* interface is up */
+#define IFF_BROADCAST 0x2 /* broadcast address valid */
+#define IFF_DEBUG 0x4 /* turn on debugging */
+#define IFF_LOOPBACK 0x8 /* is a loopback net */
+#define IFF_POINTOPOINT 0x10 /* interface is point-to-point link */
+#define IFF_NOTRAILERS 0x20 /* avoid use of trailers */
+#define IFF_RUNNING 0x40 /* resources allocated */
+#define IFF_NOARP 0x80 /* no address resolution protocol */
+/* next two not supported now, but reserved: */
+#define IFF_PROMISC 0x100 /* receive all packets */
+#define IFF_ALLMULTI 0x200 /* receive all multicast packets */
+#define IFF_OACTIVE 0x400 /* transmission in progress */
+#define IFF_SIMPLEX 0x800 /* can't hear own transmissions */
+
+/* flags set internally only: */
+#define IFF_CANTCHANGE (IFF_BROADCAST|IFF_POINTOPOINT|IFF_RUNNING|IFF_OACTIVE)
+
+/*
+ * Output queues (ifp->if_snd) and internetwork datagram level (pup level 1)
+ * input routines have queues of messages stored on ifqueue structures
+ * (defined above). Entries are added to and deleted from these structures
+ * by these macros, which should be called with ipl raised to splimp().
+ */
+#define IF_QFULL(ifq) ((ifq)->ifq_len >= (ifq)->ifq_maxlen)
+#define IF_DROP(ifq) ((ifq)->ifq_drops++)
+#define IF_ENQUEUE(ifq, m) { \
+ (m)->m_nextpkt = 0; \
+ if ((ifq)->ifq_tail == 0) \
+ (ifq)->ifq_head = m; \
+ else \
+ (ifq)->ifq_tail->m_nextpkt = m; \
+ (ifq)->ifq_tail = m; \
+ (ifq)->ifq_len++; \
+}
+#define IF_PREPEND(ifq, m) { \
+ (m)->m_nextpkt = (ifq)->ifq_head; \
+ if ((ifq)->ifq_tail == 0) \
+ (ifq)->ifq_tail = (m); \
+ (ifq)->ifq_head = (m); \
+ (ifq)->ifq_len++; \
+}
+#define IF_DEQUEUE(ifq, m) { \
+ (m) = (ifq)->ifq_head; \
+ if (m) { \
+ if (((ifq)->ifq_head = (m)->m_nextpkt) == 0) \
+ (ifq)->ifq_tail = 0; \
+ (m)->m_nextpkt = 0; \
+ (ifq)->ifq_len--; \
+ } \
+}
+
+#define IFQ_MAXLEN 50
+#define IFNET_SLOWHZ 1 /* granularity is 1 second */
+
+/*
+ * The ifaddr structure contains information about one address
+ * of an interface. They are maintained by the different address families,
+ * are allocated and attached when an address is set, and are linked
+ * together so all addresses for an interface can be located.
+ */
+struct ifaddr {
+ struct sockaddr *ifa_addr; /* address of interface */
+ struct sockaddr *ifa_dstaddr; /* other end of p-to-p link */
+#define ifa_broadaddr ifa_dstaddr /* broadcast address interface */
+ struct sockaddr *ifa_netmask; /* used to determine subnet */
+ struct ifnet *ifa_ifp; /* back-pointer to interface */
+ struct ifaddr *ifa_next; /* next address for interface */
+ int (*ifa_rtrequest)(); /* check or clean routes (+ or -)'d */
+ struct rtentry *ifa_rt; /* ??? for ROUTETOIF */
+ u_short ifa_flags; /* mostly rt_flags for cloning */
+ u_short ifa_llinfolen; /* extra to malloc for link info */
+};
+#define IFA_ROUTE RTF_UP /* route installed */
+/*
+ * Interface request structure used for socket
+ * ioctl's. All interface ioctl's must have parameter
+ * definitions which begin with ifr_name. The
+ * remainder may be interface specific.
+ */
+struct ifreq {
+#define IFNAMSIZ 16
+ char ifr_name[IFNAMSIZ]; /* if name, e.g. "en0" */
+ union {
+ struct sockaddr ifru_addr;
+ struct sockaddr ifru_dstaddr;
+ struct sockaddr ifru_broadaddr;
+ short ifru_flags;
+ int ifru_metric;
+ caddr_t ifru_data;
+ } ifr_ifru;
+#define ifr_addr ifr_ifru.ifru_addr /* address */
+#define ifr_dstaddr ifr_ifru.ifru_dstaddr /* other end of p-to-p link */
+#define ifr_broadaddr ifr_ifru.ifru_broadaddr /* broadcast address */
+#define ifr_flags ifr_ifru.ifru_flags /* flags */
+#define ifr_metric ifr_ifru.ifru_metric /* metric */
+#define ifr_data ifr_ifru.ifru_data /* for use by interface */
+};
+
+struct ifaliasreq {
+ char ifra_name[IFNAMSIZ]; /* if name, e.g. "en0" */
+ struct sockaddr ifra_addr;
+ struct sockaddr ifra_broadaddr;
+ struct sockaddr ifra_mask;