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

/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/

#ifndef lint
static char sccsid[] = "@(#)if.c        5.2 (Berkeley) %G%";
#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 (maybe == 0 && (*netmatch)(addr, &ifp->int_addr))
                       maybe = ifp;
       }
       if (ifp == 0)
               ifp = maybe;
       return (ifp);
}