usr/src/sys/net/bpfdesc.h

/*
 * Copyright (c) 1990, 1991 Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from the Stanford/CMU enet packet filter,
 * (net/enet.c) distributed as part of 4.3BSD, and code contributed
 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
 * Berkeley Laboratory.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)bpfdesc.h   7.5 (Berkeley) %G%
 *
 * @(#) $Header: bpfdesc.h,v 1.9 91/10/27 21:22:38 mccanne Exp $ (LBL)
 */

/*
 * Descriptor associated with each open bpf file.
 */
struct bpf_d {
        struct bpf_d    *bd_next;       /* Linked list of descriptors */
        /*
         * Buffer slots: two mbuf clusters buffer the incoming packets.
         *   The model has three slots.  Sbuf is always occupied.
         *   sbuf (store) - Receive interrupt puts packets here.
         *   hbuf (hold) - When sbuf is full, put cluster here and
         *                 wakeup read (replace sbuf with fbuf).
         *   fbuf (free) - When read is done, put cluster here.
         * On receiving, if sbuf is full and fbuf is 0, packet is dropped.
         */
        caddr_t         bd_sbuf;        /* store slot */
        caddr_t         bd_hbuf;        /* hold slot */
        caddr_t         bd_fbuf;        /* free slot */
        int             bd_slen;        /* current length of store buffer */
        int             bd_hlen;        /* current length of hold buffer */

        int             bd_bufsize;     /* absolute length of buffers */

        struct bpf_if * bd_bif;         /* interface descriptor */
        u_long          bd_rtout;       /* Read timeout in 'ticks' */
        struct bpf_insn *bd_filter;     /* filter code */
        u_long          bd_rcount;      /* number of packets received */
        u_long          bd_dcount;      /* number of packets dropped */

        u_char          bd_promisc;     /* true if listening promiscuously */
        u_char          bd_state;       /* idle, waiting, or timed out */
        u_char          bd_immediate;   /* true to return on packet arrival */
#if BSD < 199103
        u_char          bd_selcoll;     /* true if selects collide */
        int             bd_timedout;
        struct proc *   bd_selproc;     /* process that last selected us */
#else
        u_char          bd_pad;         /* explicit alignment */
        struct selinfo  bd_sel;         /* bsd select info */
#endif
};

/*
 * Descriptor associated with each attached hardware interface.
 */
struct bpf_if {
        struct bpf_if *bif_next;        /* list of all interfaces */
        struct bpf_d *bif_dlist;        /* descriptor list */
        struct bpf_if **bif_driverp;    /* pointer into softc */
        u_int bif_dlt;                  /* link layer type */
        u_int bif_hdrlen;               /* length of header (with padding) */
        struct ifnet *bif_ifp;          /* correspoding interface */
};