+ * 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 */
+ void (*ifa_rtrequest)(); /* check or clean routes (+ or -)'d */
+ u_short ifa_flags; /* mostly rt_flags for cloning */
+ short ifa_refcnt; /* extra to malloc for link info */
+ int ifa_metric; /* cost of going out this interface */
+#ifdef notdef
+ struct rtentry *ifa_rt; /* XXXX for ROUTETOIF ????? */
+#endif
+};
+#define IFA_ROUTE RTF_UP /* route installed */
+
+/*
+ * Message format for use in obtaining information about interfaces
+ * from getkerninfo and the routing socket
+ */
+struct if_msghdr {
+ u_short ifm_msglen; /* to skip over non-understood messages */
+ u_char ifm_version; /* future binary compatability */
+ u_char ifm_type; /* message type */
+ int ifm_addrs; /* like rtm_addrs */
+ int ifm_flags; /* value of if_flags */
+ u_short ifm_index; /* index for associated ifp */
+ struct if_data ifm_data;/* statistics and other data about if */
+};
+
+/*
+ * Message format for use in obtaining information about interface addresses
+ * from getkerninfo and the routing socket
+ */
+struct ifa_msghdr {
+ u_short ifam_msglen; /* to skip over non-understood messages */
+ u_char ifam_version; /* future binary compatability */
+ u_char ifam_type; /* message type */
+ int ifam_addrs; /* like rtm_addrs */
+ int ifam_flags; /* value of ifa_flags */
+ u_short ifam_index; /* index for associated ifp */
+ int ifam_metric; /* value of ifa_metric */
+};
+
+/*
+ * 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.