1 /* if.h 4.14 82/06/13 */ 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 * EVENTUALLY PURGE if_net AND if_host FROM STRUCTURE 34 */ 35 struct ifnet { 36 char *if_name; /* name, e.g. ``en'' or ``lo'' */ 37 short if_unit; /* sub-unit for lower level driver */ 38 short if_mtu; /* maximum transmission unit */ 39 int if_net; /* network number of interface */ 40 short if_flags; /* up/down, broadcast, etc. */ 41 int if_host[2]; /* local net host number */ 42 struct sockaddr if_addr; /* address of interface */ 43 union { 44 struct sockaddr ifu_broadaddr; 45 struct sockaddr ifu_dstaddr; 46 } if_ifu; 47 #define if_broadaddr if_ifu.ifu_broadaddr /* broadcast address */ 48 #define if_dstaddr if_ifu.ifu_dstaddr /* other end of p-to-p link */ 49 struct ifqueue { 50 struct mbuf *ifq_head; 51 struct mbuf *ifq_tail; 52 int ifq_len; 53 int ifq_maxlen; 54 int ifq_drops; 55 } if_snd; /* output queue */ 56 /* procedure handles */ 57 int (*if_init)(); /* init routine */ 58 int (*if_output)(); /* output routine */ 59 int (*if_ubareset)(); /* uba reset routine */ 60 /* generic interface statistics */ 61 int if_ipackets; /* packets received on interface */ 62 int if_ierrors; /* input errors on interface */ 63 int if_opackets; /* packets sent on interface */ 64 int if_oerrors; /* output errors on interface */ 65 int if_collisions; /* collisions on csma interfaces */ 66 /* end statistics */ 67 struct ifnet *if_next; 68 }; 69 70 #define IFF_UP 0x1 /* interface is up */ 71 #define IFF_BROADCAST 0x2 /* broadcast address valid */ 72 #define IFF_DEBUG 0x4 /* turn on debugging */ 73 #define IFF_ROUTE 0x8 /* routing entry installed */ 74 #define IFF_POINTOPOINT 0x10 /* interface is point-to-point link */ 75 76 /* 77 * Output queues (ifp->if_snd) and internetwork datagram level (pup level 1) 78 * input routines have queues of messages stored on ifqueue structures 79 * (defined above). Entries are added to and deleted from these structures 80 * by these macros, which should be called with ipl raised to splimp(). 81 */ 82 #define IF_QFULL(ifq) ((ifq)->ifq_len >= (ifq)->ifq_maxlen) 83 #define IF_DROP(ifq) ((ifq)->ifq_drops++) 84 #define IF_ENQUEUE(ifq, m) { \ 85 (m)->m_act = 0; \ 86 if ((ifq)->ifq_tail == 0) \ 87 (ifq)->ifq_head = m; \ 88 else \ 89 (ifq)->ifq_tail->m_act = m; \ 90 (ifq)->ifq_tail = m; \ 91 (ifq)->ifq_len++; \ 92 } 93 #define IF_PREPEND(ifq, m) { \ 94 (m)->m_act = (ifq)->ifq_head; \ 95 if ((ifq)->ifq_tail == 0) \ 96 (ifq)->ifq_tail = (m); \ 97 (ifq)->ifq_head = (m); \ 98 (ifq)->ifq_len++; \ 99 } 100 #define IF_DEQUEUE(ifq, m) { \ 101 (m) = (ifq)->ifq_head; \ 102 if (m) { \ 103 if (((ifq)->ifq_head = (m)->m_act) == 0) \ 104 (ifq)->ifq_tail = 0; \ 105 (m)->m_act = 0; \ 106 (ifq)->ifq_len--; \ 107 } \ 108 } 109 110 #define IFQ_MAXLEN 50 111 112 #ifdef KERNEL 113 #ifdef INET 114 struct ifqueue ipintrq; /* ip packet input queue */ 115 #endif 116 struct ifqueue rawintrq; /* raw packet input queue */ 117 struct ifnet *ifnet; 118 struct ifnet *if_ifwithaddr(), *if_ifwithnet(), *if_ifwithaf(); 119 struct ifnet *if_ifonnetof(); 120 struct in_addr if_makeaddr(); 121 #endif 122