FreeBSD/Linux Kernel Cross Reference
sys/net/bpfdesc.h

     /*
      * Copyright (c) 1990, 1991, 1993
      *      The 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.
      *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by the University of
     *      California, Berkeley and its contributors.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      @(#)bpfdesc.h   8.1 (Berkeley) 6/10/93
     *
     * $FreeBSD: releng/5.2/sys/net/bpfdesc.h 122524 2003-11-12 03:14:31Z rwatson $
     */
    
    #ifndef _NET_BPFDESC_H_
    #define _NET_BPFDESC_H_
    
    #include <sys/callout.h>
    #include <sys/selinfo.h>
    
    /*
     * 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 */
            int             bd_hdrcmplt;    /* false to fill in src lladdr automatically */
            int             bd_seesent;     /* true if bpf should see sent packets */
            int             bd_async;       /* non-zero if packet reception should generate signal */
            int             bd_sig;         /* signal to send upon packet reception */
            struct sigio *  bd_sigio;       /* information for async I/O */
    #if BSD < 199103
            u_char          bd_selcoll;     /* true if selects collide */
            int             bd_timedout;
            struct thread * bd_selthread;   /* process that last selected us */
    #else
            u_char          bd_pad;         /* explicit alignment */
            struct selinfo  bd_sel;         /* bsd select info */
    #endif
            struct mtx      bd_mtx;         /* mutex for this descriptor */
            struct callout  bd_callout;     /* for BPF timeouts with select */
            struct label    *bd_label;      /* MAC label for descriptor */
    };
    
    /* Values for bd_state */
    #define BPF_IDLE        0               /* no select in progress */
   #define BPF_WAITING     1               /* waiting for read timeout in select */
   #define BPF_TIMED_OUT   2               /* read timeout has expired in select */
   
   #define BPFD_LOCK(bd)           mtx_lock(&(bd)->bd_mtx)
   #define BPFD_UNLOCK(bd)         mtx_unlock(&(bd)->bd_mtx)
   
   /* Test whether a BPF is ready for read(). */
   #define bpf_ready(bd)                                            \
           ((bd)->bd_hlen != 0 ||                                   \
            (((bd)->bd_immediate || (bd)->bd_state == BPF_TIMED_OUT) && \
             (bd)->bd_slen != 0))
   
   /*
    * 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;          /* corresponding interface */
           struct mtx      bif_mtx;        /* mutex for interface */
   };
   
   #define BPFIF_LOCK(bif)         mtx_lock(&(bif)->bif_mtx)
   #define BPFIF_UNLOCK(bif)       mtx_unlock(&(bif)->bif_mtx)
   
   #endif

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