Annotation of 42BSD/sys/net/if.h, revision 1.1.1.1

1.1       root        1: /*     if.h    6.2     83/08/28        */
                      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:  * 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:        short   if_timer;               /* time 'til if_watchdog called */
                     42:        int     if_host[2];             /* local net host number */
                     43:        struct  sockaddr if_addr;       /* address of interface */
                     44:        union {
                     45:                struct  sockaddr ifu_broadaddr;
                     46:                struct  sockaddr ifu_dstaddr;
                     47:        } if_ifu;
                     48: #define        if_broadaddr    if_ifu.ifu_broadaddr    /* broadcast address */
                     49: #define        if_dstaddr      if_ifu.ifu_dstaddr      /* other end of p-to-p link */
                     50:        struct  ifqueue {
                     51:                struct  mbuf *ifq_head;
                     52:                struct  mbuf *ifq_tail;
                     53:                int     ifq_len;
                     54:                int     ifq_maxlen;
                     55:                int     ifq_drops;
                     56:        } if_snd;                       /* output queue */
                     57: /* procedure handles */
                     58:        int     (*if_init)();           /* init routine */
                     59:        int     (*if_output)();         /* output routine */
                     60:        int     (*if_ioctl)();          /* ioctl routine */
                     61:        int     (*if_reset)();          /* bus reset routine */
                     62:        int     (*if_watchdog)();       /* timer routine */
                     63: /* generic interface statistics */
                     64:        int     if_ipackets;            /* packets received on interface */
                     65:        int     if_ierrors;             /* input errors on interface */
                     66:        int     if_opackets;            /* packets sent on interface */
                     67:        int     if_oerrors;             /* output errors on interface */
                     68:        int     if_collisions;          /* collisions on csma interfaces */
                     69: /* end statistics */
                     70:        struct  ifnet *if_next;
                     71: };
                     72: 
                     73: #define        IFF_UP          0x1             /* interface is up */
                     74: #define        IFF_BROADCAST   0x2             /* broadcast address valid */
                     75: #define        IFF_DEBUG       0x4             /* turn on debugging */
                     76: #define        IFF_ROUTE       0x8             /* routing entry installed */
                     77: #define        IFF_POINTOPOINT 0x10            /* interface is point-to-point link */
                     78: #define        IFF_NOTRAILERS  0x20            /* avoid use of trailers */
                     79: #define        IFF_RUNNING     0x40            /* resources allocated */
                     80: #define        IFF_NOARP       0x80            /* no address resolution protocol */
                     81: 
                     82: /*
                     83:  * Output queues (ifp->if_snd) and internetwork datagram level (pup level 1)
                     84:  * input routines have queues of messages stored on ifqueue structures
                     85:  * (defined above).  Entries are added to and deleted from these structures
                     86:  * by these macros, which should be called with ipl raised to splimp().
                     87:  */
                     88: #define        IF_QFULL(ifq)           ((ifq)->ifq_len >= (ifq)->ifq_maxlen)
                     89: #define        IF_DROP(ifq)            ((ifq)->ifq_drops++)
                     90: #define        IF_ENQUEUE(ifq, m) { \
                     91:        (m)->m_act = 0; \
                     92:        if ((ifq)->ifq_tail == 0) \
                     93:                (ifq)->ifq_head = m; \
                     94:        else \
                     95:                (ifq)->ifq_tail->m_act = m; \
                     96:        (ifq)->ifq_tail = m; \
                     97:        (ifq)->ifq_len++; \
                     98: }
                     99: #define        IF_PREPEND(ifq, m) { \
                    100:        (m)->m_act = (ifq)->ifq_head; \
                    101:        if ((ifq)->ifq_tail == 0) \
                    102:                (ifq)->ifq_tail = (m); \
                    103:        (ifq)->ifq_head = (m); \
                    104:        (ifq)->ifq_len++; \
                    105: }
                    106: #define        IF_DEQUEUE(ifq, m) { \
                    107:        (m) = (ifq)->ifq_head; \
                    108:        if (m) { \
                    109:                if (((ifq)->ifq_head = (m)->m_act) == 0) \
                    110:                        (ifq)->ifq_tail = 0; \
                    111:                (m)->m_act = 0; \
                    112:                (ifq)->ifq_len--; \
                    113:        } \
                    114: }
                    115: 
                    116: #define        IFQ_MAXLEN      50
                    117: #define        IFNET_SLOWHZ    1               /* granularity is 1 second */
                    118: 
                    119: /*
                    120:  * Interface request structure used for socket
                    121:  * ioctl's.  All interface ioctl's must have parameter
                    122:  * definitions which begin with ifr_name.  The
                    123:  * remainder may be interface specific.
                    124:  */
                    125: struct ifreq {
                    126: #define        IFNAMSIZ        16
                    127:        char    ifr_name[IFNAMSIZ];             /* if name, e.g. "en0" */
                    128:        union {
                    129:                struct  sockaddr ifru_addr;
                    130:                struct  sockaddr ifru_dstaddr;
                    131:                short   ifru_flags;
                    132:                caddr_t ifru_data;
                    133:        } ifr_ifru;
                    134: #define        ifr_addr        ifr_ifru.ifru_addr      /* address */
                    135: #define        ifr_dstaddr     ifr_ifru.ifru_dstaddr   /* other end of p-to-p link */
                    136: #define        ifr_flags       ifr_ifru.ifru_flags     /* flags */
                    137: #define        ifr_data        ifr_ifru.ifru_data      /* for use by interface */
                    138: };
                    139: 
                    140: /*
                    141:  * Structure used in SIOCGIFCONF request.
                    142:  * Used to retrieve interface configuration
                    143:  * for machine (useful for programs which
                    144:  * must know all networks accessible).
                    145:  */
                    146: struct ifconf {
                    147:        int     ifc_len;                /* size of associated buffer */
                    148:        union {
                    149:                caddr_t ifcu_buf;
                    150:                struct  ifreq *ifcu_req;
                    151:        } ifc_ifcu;
                    152: #define        ifc_buf ifc_ifcu.ifcu_buf       /* buffer address */
                    153: #define        ifc_req ifc_ifcu.ifcu_req       /* array of structures returned */
                    154: };
                    155: 
                    156: #ifdef KERNEL
                    157: #ifdef INET
                    158: struct ifqueue ipintrq;                /* ip packet input queue */
                    159: #endif
                    160: struct ifqueue rawintrq;               /* raw packet input queue */
                    161: struct ifnet *ifnet;
                    162: struct ifnet *if_ifwithaddr(), *if_ifwithnet(), *if_ifwithaf();
                    163: struct ifnet *if_ifonnetof();
                    164: struct in_addr if_makeaddr();
                    165: #endif

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