1 /* if.h 4.11 82/03/28 */ 2 3 /* 4 * Structures defining a network interface, providing a packet 5 * transport mechanism (ala level 0 of the PUP protocols). 6 * 7 * Each interface accepts output datagrams of a specified maximum 8 * length, and provides higher level routines with input datagrams 9 * received from its medium. 10 * 11 * Output occurs when the routine if_output is called, with three parameters: 12 * (*ifp->if_output)(ifp, m, dst) 13 * Here m is the mbuf chain to be sent and dst is the destination address. 14 * The output routine encapsulates the supplied datagram if necessary, 15 * and then transmits it on its medium. 16 * 17 * On input, each interface unwraps the data received by it, and either 18 * places it on the input queue of a internetwork datagram routine 19 * and posts the associated software interrupt, or passes the datagram to a raw 20 * packet input routine. 21 * 22 * Routines exist for locating interfaces by their addresses 23 * or for locating a interface on a certain network, as well as more general 24 * routing and gateway routines maintaining information used to locate 25 * interfaces. These routines live in the files if.c and route.c 26 */ 27 28 /* 29 * Structure defining a queue for a network interface. 30 * 31 * (Would like to call this struct ``if'', but C isn't PL/1.) 32 */ 33 struct ifnet { 34 char *if_name; /* name, e.g. ``en'' or ``lo'' */ 35 short if_unit; /* sub-unit for lower level driver */ 36 short if_mtu; /* maximum transmission unit */ 37 short if_net; /* network number of interface */ 38 short if_flags; /* up/down, broadcast, etc. */ 39 int if_host[2]; /* local net host number */ 40 struct sockaddr if_addr; /* internet address of interface */ 41 struct sockaddr if_broadaddr; /* broadcast address of interface */ 42 struct ifqueue { 43 struct mbuf *ifq_head; 44 struct mbuf *ifq_tail; 45 int ifq_len; 46 int ifq_maxlen; 47 int ifq_drops; 48 } if_snd; /* output queue */ 49 /* procedure handles */ 50 int (*if_init)(); /* init routine */ 51 int (*if_output)(); /* output routine */ 52 int (*if_ubareset)(); /* uba reset routine */ 53 /* generic interface statistics */ 54 int if_ipackets; /* packets received on interface */ 55 int if_ierrors; /* input errors on interface */ 56 int if_opackets; /* packets sent on interface */ 57 int if_oerrors; /* output errors on interface */ 58 int if_collisions; /* collisions on csma interfaces */ 59 /* end statistics */ 60 struct ifnet *if_next; 61 }; 62 63 #define IFF_UP 0x1 /* interface is up */ 64 #define IFF_BROADCAST 0x2 /* broadcast address valid */ 65 #define IFF_DEBUG 0x4 /* turn on debugging */ 66 67 /* 68 * Output queues (ifp->if_snd) and internetwork datagram level (pup level 1) 69 * input routines have queues of messages stored on ifqueue structures 70 * (defined above). Entries are added to and deleted from these structures 71 * by these macros, which should be called with ipl raised to splimp(). 72 */ 73 #define IF_QFULL(ifq) ((ifq)->ifq_len >= (ifq)->ifq_maxlen) 74 #define IF_DROP(ifq) ((ifq)->ifq_drops++) 75 #define IF_ENQUEUE(ifq, m) { \ 76 (m)->m_act = 0; \ 77 if ((ifq)->ifq_tail == 0) \ 78 (ifq)->ifq_head = m; \ 79 else \ 80 (ifq)->ifq_tail->m_act = m; \ 81 (ifq)->ifq_tail = m; \ 82 (ifq)->ifq_len++; \ 83 } 84 #define IF_PREPEND(ifq, m) { \ 85 (m)->m_act = (ifq)->ifq_head; \ 86 if ((ifq)->ifq_tail == 0) \ 87 (ifq)->ifq_tail = (m); \ 88 (ifq)->ifq_head = (m); \ 89 (ifq)->ifq_len++; \ 90 } 91 #define IF_DEQUEUE(ifq, m) { \ 92 (m) = (ifq)->ifq_head; \ 93 if (m) { \ 94 if (((ifq)->ifq_head = (m)->m_act) == 0) \ 95 (ifq)->ifq_tail = 0; \ 96 (m)->m_act = 0; \ 97 (ifq)->ifq_len--; \ 98 } \ 99 } 100 101 #define IFQ_MAXLEN 50 102 103 #ifdef KERNEL 104 #ifdef INET 105 struct ifqueue ipintrq; /* ip packet input queue */ 106 #endif 107 struct ifqueue rawintrq; /* raw packet input queue */ 108 struct ifnet *ifnet; 109 struct ifnet *if_ifwithaddr(), *if_ifwithnet(), *if_ifwithaf(); 110 struct ifnet *if_ifonnetof(); 111 struct in_addr if_makeaddr(); 112 #endif 113