FreeBSD/Linux Kernel Cross Reference
sys/net/if_dead.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2009 Robert N. M. Watson
      * All rights reserved.
      *
      * 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.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
     */
    
    /*
     * When an interface has been detached but not yet freed, we set the various
     * ifnet function pointers to "ifdead" versions.  This prevents unexpected
     * calls from the network stack into the device driver after if_detach() has
     * returned.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/mbuf.h>
    #include <sys/socket.h>
    
    #include <net/if.h>
    #include <net/if_var.h>
    #include <net/if_private.h>
    
    static int
    ifdead_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa,
        struct route *ro)
    {
    
            m_freem(m);
            return (ENXIO);
    }
    
    static void
    ifdead_input(struct ifnet *ifp, struct mbuf *m)
    {
    
            m_freem(m);
    }
    
    static void
    ifdead_start(struct ifnet *ifp)
    {
    
    }
    
    static int
    ifdead_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
    {
    
            return (ENXIO);
    }
    
    static int
    ifdead_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa,
        struct sockaddr *sa)
    {
    
            *llsa = NULL;
            return (ENXIO);
    }
    
    static void
    ifdead_qflush(struct ifnet *ifp)
    {
    
    }
    
    static int
    ifdead_transmit(struct ifnet *ifp, struct mbuf *m)
    {
    
            m_freem(m);
            return (ENXIO);
    }
    
    static uint64_t
   ifdead_get_counter(struct ifnet *ifp, ift_counter cnt)
   {
   
           return (0);
   }
   
   static int
   ifdead_snd_tag_alloc(struct ifnet *ifp, union if_snd_tag_alloc_params *params,
       struct m_snd_tag **ppmt)
   {
           return (EOPNOTSUPP);
   }
   
   static void
   ifdead_ratelimit_query(struct ifnet *ifp __unused,
         struct if_ratelimit_query_results *q)
   {
           /*
            * This guy does not support
            * this interface. Not sure
            * why we would specify a
            * flag on the interface
            * that says we do.
            */
           q->rate_table = NULL;
           q->flags = RT_NOSUPPORT;
           q->max_flows = 0;
           q->number_of_rates = 0;
   }
   
   void
   if_dead(struct ifnet *ifp)
   {
   
           ifp->if_output = ifdead_output;
           ifp->if_input = ifdead_input;
           ifp->if_start = ifdead_start;
           ifp->if_ioctl = ifdead_ioctl;
           ifp->if_resolvemulti = ifdead_resolvemulti;
           ifp->if_qflush = ifdead_qflush;
           ifp->if_transmit = ifdead_transmit;
           ifp->if_get_counter = ifdead_get_counter;
           ifp->if_snd_tag_alloc = ifdead_snd_tag_alloc;
           ifp->if_ratelimit_query = ifdead_ratelimit_query;
   }

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