FreeBSD/Linux Kernel Cross Reference
sys/netinet/in_rmx.c

     /*-
      * Copyright 1994, 1995 Massachusetts Institute of Technology
      *
      * Permission to use, copy, modify, and distribute this software and
      * its documentation for any purpose and without fee is hereby
      * granted, provided that both the above copyright notice and this
      * permission notice appear in all copies, that both the above
      * copyright notice and this permission notice appear in all
      * supporting documentation, and that the name of M.I.T. not be used
     * in advertising or publicity pertaining to distribution of the
     * software without specific, written prior permission.  M.I.T. makes
     * no representations about the suitability of this software for any
     * purpose.  It is provided "as is" without express or implied
     * warranty.
     *
     * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
     * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
     * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
     * SHALL M.I.T. 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.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/11.1/sys/netinet/in_rmx.c 295529 2016-02-11 17:07:19Z dteske $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/sysctl.h>
    #include <sys/socket.h>
    #include <sys/mbuf.h>
    
    #include <net/if.h>
    #include <net/if_var.h>
    #include <net/route.h>
    #include <net/route_var.h>
    #include <net/vnet.h>
    
    #include <netinet/in.h>
    #include <netinet/in_var.h>
    #include <netinet/ip.h>
    #include <netinet/ip_icmp.h>
    #include <netinet/ip_var.h>
    
    extern int      in_inithead(void **head, int off);
    #ifdef VIMAGE
    extern int      in_detachhead(void **head, int off);
    #endif
    
    /*
     * Do what we need to do when inserting a route.
     */
    static struct radix_node *
    in_addroute(void *v_arg, void *n_arg, struct radix_head *head,
        struct radix_node *treenodes)
    {
            struct rtentry *rt = (struct rtentry *)treenodes;
            struct sockaddr_in *sin = (struct sockaddr_in *)rt_key(rt);
    
            /*
             * A little bit of help for both IP output and input:
             *   For host routes, we make sure that RTF_BROADCAST
             *   is set for anything that looks like a broadcast address.
             *   This way, we can avoid an expensive call to in_broadcast()
             *   in ip_output() most of the time (because the route passed
             *   to ip_output() is almost always a host route).
             *
             *   We also do the same for local addresses, with the thought
             *   that this might one day be used to speed up ip_input().
             *
             * We also mark routes to multicast addresses as such, because
             * it's easy to do and might be useful (but this is much more
             * dubious since it's so easy to inspect the address).
             */
            if (rt->rt_flags & RTF_HOST) {
                    if (in_broadcast(sin->sin_addr, rt->rt_ifp)) {
                            rt->rt_flags |= RTF_BROADCAST;
                    } else if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr ==
                        sin->sin_addr.s_addr) {
                            rt->rt_flags |= RTF_LOCAL;
                    }
            }
            if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
                    rt->rt_flags |= RTF_MULTICAST;
    
            if (rt->rt_ifp != NULL) {
    
                    /*
                     * Check route MTU:
                     * inherit interface MTU if not set or
                     * check if MTU is too large.
                     */
                   if (rt->rt_mtu == 0) {
                           rt->rt_mtu = rt->rt_ifp->if_mtu;
                   } else if (rt->rt_mtu > rt->rt_ifp->if_mtu)
                           rt->rt_mtu = rt->rt_ifp->if_mtu;
           }
   
           return (rn_addroute(v_arg, n_arg, head, treenodes));
   }
   
   static int _in_rt_was_here;
   /*
    * Initialize our routing tree.
    */
   int
   in_inithead(void **head, int off)
   {
           struct rib_head *rh;
   
           rh = rt_table_init(32);
           if (rh == NULL)
                   return (0);
   
           rh->rnh_addaddr = in_addroute;
           *head = (void *)rh;
   
           if (_in_rt_was_here == 0 ) {
                   _in_rt_was_here = 1;
           }
           return 1;
   }
   
   #ifdef VIMAGE
   int
   in_detachhead(void **head, int off)
   {
   
           rt_table_destroy((struct rib_head *)(*head));
           return (1);
   }
   #endif
   
   /*
    * This zaps old routes when the interface goes down or interface
    * address is deleted.  In the latter case, it deletes static routes
    * that point to this address.  If we don't do this, we may end up
    * using the old address in the future.  The ones we always want to
    * get rid of are things like ARP entries, since the user might down
    * the interface, walk over to a completely different network, and
    * plug back in.
    */
   struct in_ifadown_arg {
           struct ifaddr *ifa;
           int del;
   };
   
   static int
   in_ifadownkill(const struct rtentry *rt, void *xap)
   {
           struct in_ifadown_arg *ap = xap;
   
           if (rt->rt_ifa != ap->ifa)
                   return (0);
   
           if ((rt->rt_flags & RTF_STATIC) != 0 && ap->del == 0)
                   return (0);
   
           return (1);
   }
   
   void
   in_ifadown(struct ifaddr *ifa, int delete)
   {
           struct in_ifadown_arg arg;
   
           KASSERT(ifa->ifa_addr->sa_family == AF_INET,
               ("%s: wrong family", __func__));
   
           arg.ifa = ifa;
           arg.del = delete;
   
           rt_foreach_fib_walk_del(AF_INET, in_ifadownkill, &arg);
           ifa->ifa_flags &= ~IFA_ROUTE;           /* XXXlocking? */
   }
   
   /*
    * inet versions of rt functions. These have fib extensions and 
    * for now will just reference the _fib variants.
    * eventually this order will be reversed,
    */
   void
   in_rtalloc_ign(struct route *ro, u_long ignflags, u_int fibnum)
   {
           rtalloc_ign_fib(ro, ignflags, fibnum);
   }
   
   void
   in_rtredirect(struct sockaddr *dst,
           struct sockaddr *gateway,
           struct sockaddr *netmask,
           int flags,
           struct sockaddr *src,
           u_int fibnum)
   {
           rtredirect_fib(dst, gateway, netmask, flags, src, fibnum);
   }
    

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