BSD 4_3_Net_2 release

[unix-history] / usr / src / sbin / routed / if.c

/*
* Copyright (c) 1983 Regents of the University of California.
* 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.
* 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.
*/

#ifndef lint
static char sccsid[] = "@(#)if.c        5.6 (Berkeley) 6/1/90";
#endif /* not lint */

/*
* Routing Table Management Daemon
*/
#include "defs.h"

extern  struct interface *ifnet;

/*
* Find the interface with address addr.
*/
struct interface *
if_ifwithaddr(addr)
       struct sockaddr *addr;
{
       register struct interface *ifp;

#define same(a1, a2) \
       (bcmp((caddr_t)((a1)->sa_data), (caddr_t)((a2)->sa_data), 14) == 0)
       for (ifp = ifnet; ifp; ifp = ifp->int_next) {
               if (ifp->int_flags & IFF_REMOTE)
                       continue;
               if (ifp->int_addr.sa_family != addr->sa_family)
                       continue;
               if (same(&ifp->int_addr, addr))
                       break;
               if ((ifp->int_flags & IFF_BROADCAST) &&
                   same(&ifp->int_broadaddr, addr))
                       break;
       }
       return (ifp);
}

/*
* Find the point-to-point interface with destination address addr.
*/
struct interface *
if_ifwithdstaddr(addr)
       struct sockaddr *addr;
{
       register struct interface *ifp;

       for (ifp = ifnet; ifp; ifp = ifp->int_next) {
               if ((ifp->int_flags & IFF_POINTOPOINT) == 0)
                       continue;
               if (same(&ifp->int_dstaddr, addr))
                       break;
       }
       return (ifp);
}

/*
* Find the interface on the network 
* of the specified address.
*/
struct interface *
if_ifwithnet(addr)
       register struct sockaddr *addr;
{
       register struct interface *ifp;
       register int af = addr->sa_family;
       register int (*netmatch)();

       if (af >= af_max)
               return (0);
       netmatch = afswitch[af].af_netmatch;
       for (ifp = ifnet; ifp; ifp = ifp->int_next) {
               if (ifp->int_flags & IFF_REMOTE)
                       continue;
               if (af != ifp->int_addr.sa_family)
                       continue;
               if ((*netmatch)(addr, &ifp->int_addr))
                       break;
       }
       return (ifp);
}

/*
* Find an interface from which the specified address
* should have come from.  Used for figuring out which
* interface a packet came in on -- for tracing.
*/
struct interface *
if_iflookup(addr)
       struct sockaddr *addr;
{
       register struct interface *ifp, *maybe;
       register int af = addr->sa_family;
       register int (*netmatch)();

       if (af >= af_max)
               return (0);
       maybe = 0;
       netmatch = afswitch[af].af_netmatch;
       for (ifp = ifnet; ifp; ifp = ifp->int_next) {
               if (ifp->int_addr.sa_family != af)
                       continue;
               if (same(&ifp->int_addr, addr))
                       break;
               if ((ifp->int_flags & IFF_BROADCAST) &&
                   same(&ifp->int_broadaddr, addr))
                       break;
               if ((ifp->int_flags & IFF_POINTOPOINT) &&
                   same(&ifp->int_dstaddr, addr))
                       break;
               if (maybe == 0 && (*netmatch)(addr, &ifp->int_addr))
                       maybe = ifp;
       }
       if (ifp == 0)
               ifp = maybe;
       return (ifp);
}