MFC r1.27:

[dragonfly.git] / sys / netproto / atalk / at_control.c

/*
 * Copyright (c) 1990,1991 Regents of The University of Michigan.
 * All Rights Reserved.
 *
 * $DragonFly: src/sys/netproto/atalk/at_control.c,v 1.13 2008/03/07 11:34:21 sephe Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/sockio.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/thread2.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#undef s_net
#include <netinet/if_ether.h>

#include "at.h"
#include "at_var.h"
#include "at_extern.h"

struct at_ifaddr        *at_ifaddr;

static int aa_dorangeroute(struct ifaddr *ifa,
                        u_int first, u_int last, int cmd);
static int aa_addsingleroute(struct ifaddr *ifa,
                        struct at_addr *addr, struct at_addr *mask);
static int aa_delsingleroute(struct ifaddr *ifa,
                        struct at_addr *addr, struct at_addr *mask);
static int aa_dosingleroute(struct ifaddr *ifa, struct at_addr *addr,
                        struct at_addr *mask, int cmd, int flags);
static int at_scrub( struct ifnet *ifp, struct at_ifaddr *aa );
static int at_ifinit( struct ifnet *ifp, struct at_ifaddr *aa,
                                        struct sockaddr_at *sat );
static int aa_claim_addr(struct ifaddr *ifa, struct sockaddr *gw);

# define sateqaddr(a,b) ((a)->sat_len == (b)->sat_len && \
                    (a)->sat_family == (b)->sat_family && \
                    (a)->sat_addr.s_net == (b)->sat_addr.s_net && \
                    (a)->sat_addr.s_node == (b)->sat_addr.s_node )

int
at_control(struct socket *so, u_long cmd, caddr_t data,
                struct ifnet *ifp, struct thread *td )
{
    struct ifreq        *ifr = (struct ifreq *)data;
    struct sockaddr_at  *sat;
    struct netrange     *nr;
    struct at_aliasreq  *ifra = (struct at_aliasreq *)data;
    struct at_ifaddr    *aa0;
    struct at_ifaddr    *aa = 0;
    struct ifaddr       *ifa, *ifa0;
    int error;

    /*
     * If we have an ifp, then find the matching at_ifaddr if it exists
     */
    if ( ifp ) {
        for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
            if ( aa->aa_ifp == ifp ) break;
        }
    }

    /*
     * In this first switch table we are basically getting ready for
     * the second one, by getting the atalk-specific things set up
     * so that they start to look more similar to other protocols etc.
     */

    switch ( cmd ) {
    case SIOCAIFADDR:
    case SIOCDIFADDR:
        /*
         * If we have an appletalk sockaddr, scan forward of where
         * we are now on the at_ifaddr list to find one with a matching 
         * address on this interface.
         * This may leave aa pointing to the first address on the
         * NEXT interface!
         */
        if ( ifra->ifra_addr.sat_family == AF_APPLETALK ) {
            for ( ; aa; aa = aa->aa_next ) {
                if ( aa->aa_ifp == ifp &&
                        sateqaddr( &aa->aa_addr, &ifra->ifra_addr )) {
                    break;
                }
            }
        }
        /*
         * If we a retrying to delete an addres but didn't find such,
         * then rewurn with an error
         */
        if ( cmd == SIOCDIFADDR && aa == 0 ) {
            return( EADDRNOTAVAIL );
        }
        /*FALLTHROUGH*/

    case SIOCSIFADDR:
        /* 
         * If we are not superuser, then we don't get to do these ops.
         */
        if (suser(td))
            return(EPERM);

        sat = satosat( &ifr->ifr_addr );
        nr = (struct netrange *)sat->sat_zero;
        if ( nr->nr_phase == 1 ) {
            /*
             * Look for a phase 1 address on this interface.
             * This may leave aa pointing to the first address on the
             * NEXT interface!
             */
            for ( ; aa; aa = aa->aa_next ) {
                if ( aa->aa_ifp == ifp &&
                        ( aa->aa_flags & AFA_PHASE2 ) == 0 ) {
                    break;
                }
            }
        } else {                /* default to phase 2 */
            /*
             * Look for a phase 2 address on this interface.
             * This may leave aa pointing to the first address on the
             * NEXT interface!
             */
            for ( ; aa; aa = aa->aa_next ) {
                if ( aa->aa_ifp == ifp && ( aa->aa_flags & AFA_PHASE2 )) {
                    break;
                }
            }
        }

        if ( ifp == 0 )
            panic( "at_control" );

        /*
         * If we failed to find an existing at_ifaddr entry, then we 
         * allocate a fresh one. 
         */
        if ( aa == (struct at_ifaddr *) 0 ) {
            aa0 = ifa_create(sizeof(struct at_ifaddr), M_WAITOK);
            callout_init(&aa0->aa_ch);
            if (( aa = at_ifaddr ) != NULL ) {
                /*
                 * Don't let the loopback be first, since the first
                 * address is the machine's default address for
                 * binding.
                 * If it is, stick ourself in front, otherwise
                 * go to the back of the list.
                 */
                if ( at_ifaddr->aa_ifp->if_flags & IFF_LOOPBACK ) {
                    aa = aa0;
                    aa->aa_next = at_ifaddr;
                    at_ifaddr = aa;
                } else {
                    for ( ; aa->aa_next; aa = aa->aa_next )
                        ;
                    aa->aa_next = aa0;
                }
            } else {
                at_ifaddr = aa0;
            }
            aa = aa0;

            /*
             * Find the end of the interface's addresses
             * and link our new one on the end 
             */
            ifa = (struct ifaddr *)aa;
            ifa_iflink(ifa, ifp, 1);

            /*
             * As the at_ifaddr contains the actual sockaddrs,
             * and the ifaddr itself, link them al together correctly.
             */
            ifa->ifa_addr = (struct sockaddr *)&aa->aa_addr;
            ifa->ifa_dstaddr = (struct sockaddr *)&aa->aa_addr;
            ifa->ifa_netmask = (struct sockaddr *)&aa->aa_netmask;

            /*
             * Set/clear the phase 2 bit.
             */
            if ( nr->nr_phase == 1 ) {
                aa->aa_flags &= ~AFA_PHASE2;
            } else {
                aa->aa_flags |= AFA_PHASE2;
            }

            /*
             * and link it all together
             */
            aa->aa_ifp = ifp;
        } else {
            /*
             * If we DID find one then we clobber any routes dependent on it..
             */
            at_scrub( ifp, aa );
        }
        break;

    case SIOCGIFADDR :
        sat = satosat( &ifr->ifr_addr );
        nr = (struct netrange *)sat->sat_zero;
        if ( nr->nr_phase == 1 ) {
            /*
             * If the request is specifying phase 1, then
             * only look at a phase one address
             */
            for ( ; aa; aa = aa->aa_next ) {
                if ( aa->aa_ifp == ifp &&
                        ( aa->aa_flags & AFA_PHASE2 ) == 0 ) {
                    break;
                }
            }
        } else {
            /*
             * default to phase 2
             */
            for ( ; aa; aa = aa->aa_next ) {
                if ( aa->aa_ifp == ifp && ( aa->aa_flags & AFA_PHASE2 )) {
                    break;
                }
            }
        }

        if ( aa == (struct at_ifaddr *) 0 )
            return( EADDRNOTAVAIL );
        break;
    }

    /*
     * By the time this switch is run we should be able to assume that
     * the "aa" pointer is valid when needed.
     */
    switch ( cmd ) {
    case SIOCGIFADDR:

        /*
         * copy the contents of the sockaddr blindly.
         */
        sat = (struct sockaddr_at *)&ifr->ifr_addr;
        *sat = aa->aa_addr;

        /* 
         * and do some cleanups
         */
        ((struct netrange *)&sat->sat_zero)->nr_phase
                = (aa->aa_flags & AFA_PHASE2) ? 2 : 1;
        ((struct netrange *)&sat->sat_zero)->nr_firstnet = aa->aa_firstnet;
        ((struct netrange *)&sat->sat_zero)->nr_lastnet = aa->aa_lastnet;
        break;

    case SIOCSIFADDR:
        return( at_ifinit( ifp, aa, (struct sockaddr_at *)&ifr->ifr_addr ));

    case SIOCAIFADDR:
        if ( sateqaddr( &ifra->ifra_addr, &aa->aa_addr )) {
            return( 0 );
        }
        return( at_ifinit( ifp, aa, (struct sockaddr_at *)&ifr->ifr_addr ));

    case SIOCDIFADDR:
        /*
         * scrub all routes.. didn't we just DO this? XXX yes, del it
         */
        at_scrub( ifp, aa );

        /*
         * remove the ifaddr from the interface
         */
        ifa0 = (struct ifaddr *)aa;
        ifa_ifunlink(ifa0, ifp);

        /*
         * Now remove the at_ifaddr from the parallel structure
         * as well, or we'd be in deep trouble
         */
        aa0 = aa;
        if ( aa0 == ( aa = at_ifaddr )) {
            at_ifaddr = aa->aa_next;
        } else {
            while ( aa->aa_next && ( aa->aa_next != aa0 )) {
                aa = aa->aa_next;
            }

            /*
             * if we found it, remove it, otherwise we screwed up.
             */
            if ( aa->aa_next ) {
                aa->aa_next = aa0->aa_next;
            } else {
                panic( "at_control" );
            }
        }

        /*
         * Now dump the memory we were using.
         * Decrement the reference count.
         * This should probably be the last reference
         * as the count will go from 1 to 0.
         * (unless there is still a route referencing this)
         */
        ifa_destroy(ifa0);
        break;

    default:
        if ( ifp == 0 || ifp->if_ioctl == 0 )
            return( EOPNOTSUPP );
        lwkt_serialize_enter(ifp->if_serializer);
        error = ifp->if_ioctl(ifp, cmd, data, td->td_proc->p_ucred);
        lwkt_serialize_exit(ifp->if_serializer);
        return (error);
    }
    return( 0 );
}

/* 
 * Given an interface and an at_ifaddr (supposedly on that interface)
 * remove  any routes that depend on this.
 * Why ifp is needed I'm not sure,
 * as aa->at_ifaddr.ifa_ifp should be the same.
 */
static int
at_scrub(struct ifnet *ifp, struct at_ifaddr *aa)
{
    int                 error;

    if ( aa->aa_flags & AFA_ROUTE ) {
        if (ifp->if_flags & IFF_LOOPBACK) {
                if ((error = aa_delsingleroute(&aa->aa_ifa,
                                        &aa->aa_addr.sat_addr,
                                        &aa->aa_netmask.sat_addr)) != 0) {
                        return( error );
                }
        } else if (ifp->if_flags & IFF_POINTOPOINT) {
                if ((error = rtinit( &aa->aa_ifa, RTM_DELETE, RTF_HOST)) != 0)
                        return( error );
        } else if (ifp->if_flags & IFF_BROADCAST) {
                error = aa_dorangeroute(&aa->aa_ifa,
                                ntohs(aa->aa_firstnet),
                                ntohs(aa->aa_lastnet),
                                RTM_DELETE );
        }
        aa->aa_ifa.ifa_flags &= ~IFA_ROUTE;
        aa->aa_flags &= ~AFA_ROUTE;
    }
    return( 0 );
}

/*
 * given an at_ifaddr,a sockaddr_at and an ifp,
 * bang them all together at high speed and see what happens
 */
static int 
at_ifinit(struct ifnet *ifp, struct at_ifaddr *aa, struct sockaddr_at *sat)
{
    struct netrange     nr, onr;
    struct sockaddr_at  oldaddr;
    int                 error = 0, i, j;
    int                 netinc, nodeinc, nnets;
    u_short             net;

    crit_enter();

    /* 
     * save the old addresses in the at_ifaddr just in case we need them.
     */
    oldaddr = aa->aa_addr;
    onr.nr_firstnet = aa->aa_firstnet;
    onr.nr_lastnet = aa->aa_lastnet;

    /*
     * take the address supplied as an argument, and add it to the 
     * at_ifnet (also given). Remember ing to update
     * those parts of the at_ifaddr that need special processing
     */
    bzero( AA_SAT( aa ), sizeof( struct sockaddr_at ));
    bcopy( sat->sat_zero, &nr, sizeof( struct netrange ));
    bcopy( sat->sat_zero, AA_SAT( aa )->sat_zero, sizeof( struct netrange ));
    nnets = ntohs( nr.nr_lastnet ) - ntohs( nr.nr_firstnet ) + 1;
    aa->aa_firstnet = nr.nr_firstnet;
    aa->aa_lastnet = nr.nr_lastnet;

/* XXX ALC */
#if 0
    kprintf("at_ifinit: %s: %u.%u range %u-%u phase %d\n",
        ifp->if_name,
        ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node,
        ntohs(aa->aa_firstnet), ntohs(aa->aa_lastnet),
        (aa->aa_flags & AFA_PHASE2) ? 2 : 1);
#endif

    /*
     * We could eliminate the need for a second phase 1 probe (post
     * autoconf) if we check whether we're resetting the node. Note
     * that phase 1 probes use only nodes, not net.node pairs.  Under
     * phase 2, both the net and node must be the same.
     */
    if ( ifp->if_flags & IFF_LOOPBACK ) {
        AA_SAT( aa )->sat_len = sat->sat_len;
        AA_SAT( aa )->sat_family = AF_APPLETALK;
        AA_SAT( aa )->sat_addr.s_net = sat->sat_addr.s_net;
        AA_SAT( aa )->sat_addr.s_node = sat->sat_addr.s_node;
#if 0
    } else if ( fp->if_flags & IFF_POINTOPOINT) {
        /* unimplemented */
        /*
         * we'd have to copy the dstaddr field over from the sat 
         * but it's not clear that it would contain the right info..
         */
#endif
    } else {
        /*
         * We are a normal (probably ethernet) interface.
         * apply the new address to the interface structures etc.
         * We will probe this address on the net first, before
         * applying it to ensure that it is free.. If it is not, then
         * we will try a number of other randomly generated addresses
         * in this net and then increment the net.  etc.etc. until
         * we find an unused address.
         */
        aa->aa_flags |= AFA_PROBING; /* if not loopback we Must probe? */
        AA_SAT( aa )->sat_len = sizeof(struct sockaddr_at);
        AA_SAT( aa )->sat_family = AF_APPLETALK;
        if ( aa->aa_flags & AFA_PHASE2 ) {
            if ( sat->sat_addr.s_net == ATADDR_ANYNET ) {
                /*
                 * If we are phase 2, and the net was not specified
                 * then we select a random net within the supplied netrange.
                 * XXX use /dev/random?
                 */
                if ( nnets != 1 ) {
                    net = ntohs( nr.nr_firstnet ) + time_second % ( nnets - 1 );
                } else {
                    net = ntohs( nr.nr_firstnet );
                }
            } else {
                /*
                 * if a net was supplied, then check that it is within
                 * the netrange. If it is not then replace the old values
                 * and return an error
                 */
                if ( ntohs( sat->sat_addr.s_net ) < ntohs( nr.nr_firstnet ) ||
                        ntohs( sat->sat_addr.s_net ) > ntohs( nr.nr_lastnet )) {
                    aa->aa_addr = oldaddr;
                    aa->aa_firstnet = onr.nr_firstnet;
                    aa->aa_lastnet = onr.nr_lastnet;
                    crit_exit();
                    return( EINVAL );
                }
                /*
                 * otherwise just use the new net number..
                 */
                net = ntohs( sat->sat_addr.s_net );
            }
        } else {
            /*
             * we must be phase one, so just use whatever we were given.
             * I guess it really isn't going to be used... RIGHT?
             */
            net = ntohs( sat->sat_addr.s_net );
        }

        /* 
         * set the node part of the address into the ifaddr.
         * If it's not specified, be random about it...
         * XXX use /dev/random?
         */
        if ( sat->sat_addr.s_node == ATADDR_ANYNODE ) {
            AA_SAT( aa )->sat_addr.s_node = time_second;
        } else {
            AA_SAT( aa )->sat_addr.s_node = sat->sat_addr.s_node;
        }

        /* 
         * Copy the phase.
         */
        AA_SAT( aa )->sat_range.r_netrange.nr_phase
                = ((aa->aa_flags & AFA_PHASE2) ? 2:1);

        /* 
         * step through the nets in the range
         * starting at the (possibly random) start point.
         */
        for ( i = nnets, netinc = 1; i > 0; net = ntohs( nr.nr_firstnet ) +
                (( net - ntohs( nr.nr_firstnet ) + netinc ) % nnets ), i-- ) {
            AA_SAT( aa )->sat_addr.s_net = htons( net );

            /*
             * using a rather strange stepping method,
             * stagger through the possible node addresses
             * Once again, starting at the (possibly random)
             * initial node address.
             */
            for ( j = 0, nodeinc = time_second | 1; j < 256;
                    j++, AA_SAT( aa )->sat_addr.s_node += nodeinc ) {
                if ( AA_SAT( aa )->sat_addr.s_node > 253 ||
                        AA_SAT( aa )->sat_addr.s_node < 1 ) {
                    continue;
                }
                aa->aa_probcnt = 10;

                /*
                 * start off the probes as an asynchronous activity.
                 * though why wait 200mSec?
                 */
                callout_reset(&aa->aa_ch, hz / 5, aarpprobe, ifp);
                if ( tsleep( aa, PCATCH, "at_ifinit", 0 )) {
                    /*
                     * theoretically we shouldn't time out here
                     * so if we returned with an error..
                     */
                    kprintf( "at_ifinit: why did this happen?!\n" );
                    aa->aa_addr = oldaddr;
                    aa->aa_firstnet = onr.nr_firstnet;
                    aa->aa_lastnet = onr.nr_lastnet;
                    crit_exit();
                    return( EINTR );
                }

                /* 
                 * The async activity should have woken us up.
                 * We need to see if it was successful in finding
                 * a free spot, or if we need to iterate to the next 
                 * address to try.
                 */
                if (( aa->aa_flags & AFA_PROBING ) == 0 ) {
                    break;
                }
            }

            /*
             * of course we need to break out through two loops...
             */
            if (( aa->aa_flags & AFA_PROBING ) == 0 ) {
                break;
            }
            /* reset node for next network */
            AA_SAT( aa )->sat_addr.s_node = time_second;
        }

        /*
         * if we are still trying to probe, then we have finished all
         * the possible addresses, so we need to give up
         */

        if ( aa->aa_flags & AFA_PROBING ) {
            aa->aa_addr = oldaddr;
            aa->aa_firstnet = onr.nr_firstnet;
            aa->aa_lastnet = onr.nr_lastnet;
            crit_exit();
            return( EADDRINUSE );
        }
    }

    /* 
     * Now that we have selected an address, we need to tell the interface
     * about it, just in case it needs to adjust something.
     */
    lwkt_serialize_enter(ifp->if_serializer);
    if (ifp->if_ioctl &&
        (error = ifp->if_ioctl(ifp, SIOCSIFADDR, (caddr_t)aa, NULL))
    ) {
        /*
         * of course this could mean that it objects violently
         * so if it does, we back out again..
         */
        aa->aa_addr = oldaddr;
        aa->aa_firstnet = onr.nr_firstnet;
        aa->aa_lastnet = onr.nr_lastnet;
        lwkt_serialize_exit(ifp->if_serializer);
        crit_exit();
        return( error );
    }
    lwkt_serialize_exit(ifp->if_serializer);

    /* 
     * set up the netmask part of the at_ifaddr
     * and point the appropriate pointer in the ifaddr to it.
     * probably pointless, but what the heck.. XXX
     */
    bzero(&aa->aa_netmask, sizeof(aa->aa_netmask));
    aa->aa_netmask.sat_len = sizeof(struct sockaddr_at);
    aa->aa_netmask.sat_family = AF_APPLETALK;
    aa->aa_netmask.sat_addr.s_net = 0xffff;
    aa->aa_netmask.sat_addr.s_node = 0;
    aa->aa_ifa.ifa_netmask =(struct sockaddr *) &(aa->aa_netmask); /* XXX */

    /*
     * Initialize broadcast (or remote p2p) address
     */
    bzero(&aa->aa_broadaddr, sizeof(aa->aa_broadaddr));
    aa->aa_broadaddr.sat_len = sizeof(struct sockaddr_at);
    aa->aa_broadaddr.sat_family = AF_APPLETALK;

    aa->aa_ifa.ifa_metric = ifp->if_metric;
    if (ifp->if_flags & IFF_BROADCAST) {
        aa->aa_broadaddr.sat_addr.s_net = htons(0);
        aa->aa_broadaddr.sat_addr.s_node = 0xff;
        aa->aa_ifa.ifa_broadaddr = (struct sockaddr *) &aa->aa_broadaddr;
        /* add the range of routes needed */
        error = aa_dorangeroute(&aa->aa_ifa,
                ntohs(aa->aa_firstnet), ntohs(aa->aa_lastnet), RTM_ADD );
    }
    else if (ifp->if_flags & IFF_POINTOPOINT) {
        struct at_addr  rtaddr, rtmask;

        bzero(&rtaddr, sizeof(rtaddr));
        bzero(&rtmask, sizeof(rtmask));
        /* fill in the far end if we know it here XXX */
        aa->aa_ifa.ifa_dstaddr = (struct sockaddr *) &aa->aa_dstaddr;
        error = aa_addsingleroute(&aa->aa_ifa, &rtaddr, &rtmask);
    }
    else if ( ifp->if_flags & IFF_LOOPBACK ) {
        struct at_addr  rtaddr, rtmask;

        bzero(&rtaddr, sizeof(rtaddr));
        bzero(&rtmask, sizeof(rtmask));
        rtaddr.s_net = AA_SAT( aa )->sat_addr.s_net;
        rtaddr.s_node = AA_SAT( aa )->sat_addr.s_node;
        rtmask.s_net = 0xffff;
        rtmask.s_node = 0x0; /* XXX should not be so.. should be HOST route */
        error = aa_addsingleroute(&aa->aa_ifa, &rtaddr, &rtmask);
    }


    /*
     * set the address of our "check if this addr is ours" routine.
     */
    aa->aa_ifa.ifa_claim_addr = aa_claim_addr;

    /*
     * of course if we can't add these routes we back out, but it's getting
     * risky by now XXX
     */
    if ( error ) {
        at_scrub( ifp, aa );
        aa->aa_addr = oldaddr;
        aa->aa_firstnet = onr.nr_firstnet;
        aa->aa_lastnet = onr.nr_lastnet;
        crit_exit();
        return( error );
    }

    /*
     * note that the address has a route associated with it....
     */
    aa->aa_ifa.ifa_flags |= IFA_ROUTE;
    aa->aa_flags |= AFA_ROUTE;
    crit_exit();
    return( 0 );
}

/*
 * check whether a given address is a broadcast address for us..
 */
int
at_broadcast(struct sockaddr_at *sat)
{
    struct at_ifaddr    *aa;

    /*
     * If the node is not right, it can't be a broadcast 
     */
    if ( sat->sat_addr.s_node != ATADDR_BCAST ) {
        return( 0 );
    }

    /*
     * If the node was right then if the net is right, it's a broadcast
     */
    if ( sat->sat_addr.s_net == ATADDR_ANYNET ) {
        return( 1 );
    }

    /*
     * failing that, if the net is one we have, it's a broadcast as well.
     */
    for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
        if (( aa->aa_ifp->if_flags & IFF_BROADCAST )
         && ( ntohs( sat->sat_addr.s_net ) >= ntohs( aa->aa_firstnet )
         && ntohs( sat->sat_addr.s_net ) <= ntohs( aa->aa_lastnet ))) {
                        return( 1 );
        }
    }
    return( 0 );
}

/*
 * aa_dorangeroute()
 *
 * Add a route for a range of networks from bot to top - 1.
 * Algorithm:
 *
 * Split the range into two subranges such that the middle
 * of the two ranges is the point where the highest bit of difference
 * between the two addresses makes its transition.
 * Each of the upper and lower ranges might not exist, or might be 
 * representable by 1 or more netmasks. In addition, if both
 * ranges can be represented by the same netmask, then they can be merged
 * by using the next higher netmask..
 */

static int
aa_dorangeroute(struct ifaddr *ifa, u_int bot, u_int top, int cmd)
{
        u_int mask1;
        struct at_addr addr;
        struct at_addr mask;
        int error;

        /*
         * slight sanity check
         */
        if (bot > top) return (EINVAL);

        addr.s_node = 0;
        mask.s_node = 0;
        /*
         * just start out with the lowest boundary
         * and keep extending the mask till it's too big.
         */
        
         while (bot <= top) {
                mask1 = 1;
                while ((( bot & ~mask1) >= bot)
                   && (( bot | mask1) <= top)) {
                        mask1 <<= 1;
                        mask1 |= 1;
                }
                mask1 >>= 1;
                mask.s_net = htons(~mask1);
                addr.s_net = htons(bot);
                if(cmd == RTM_ADD) {
                error =  aa_addsingleroute(ifa,&addr,&mask);
                        if (error) {
                                /* XXX clean up? */
                                return (error);
                        }
                } else {
                        error =  aa_delsingleroute(ifa,&addr,&mask);
                }
                bot = (bot | mask1) + 1;
        }
        return 0;
}

static int
aa_addsingleroute(struct ifaddr *ifa,
        struct at_addr *addr, struct at_addr *mask)
{
  int   error;

#if 0
  kprintf("aa_addsingleroute: %x.%x mask %x.%x ...\n",
    ntohs(addr->s_net), addr->s_node,
    ntohs(mask->s_net), mask->s_node);
#endif

  error = aa_dosingleroute(ifa, addr, mask, RTM_ADD, RTF_UP);
  if (error)
    kprintf("aa_addsingleroute: error %d\n", error);
  return(error);
}

static int
aa_delsingleroute(struct ifaddr *ifa,
        struct at_addr *addr, struct at_addr *mask)
{
  int   error;

  error = aa_dosingleroute(ifa, addr, mask, RTM_DELETE, 0);
  if (error)
        kprintf("aa_delsingleroute: error %d\n", error);
  return(error);
}

static int
aa_dosingleroute(struct ifaddr *ifa,
        struct at_addr *at_addr, struct at_addr *at_mask, int cmd, int flags)
{
  struct sockaddr_at    addr, mask;

  bzero(&addr, sizeof(addr));
  bzero(&mask, sizeof(mask));
  addr.sat_family = AF_APPLETALK;
  addr.sat_len = sizeof(struct sockaddr_at);
  addr.sat_addr.s_net = at_addr->s_net;
  addr.sat_addr.s_node = at_addr->s_node;
  mask.sat_family = AF_APPLETALK;
  mask.sat_len = sizeof(struct sockaddr_at);
  mask.sat_addr.s_net = at_mask->s_net;
  mask.sat_addr.s_node = at_mask->s_node;
  if (at_mask->s_node)
    flags |= RTF_HOST;
  return(rtrequest(cmd, (struct sockaddr *) &addr,
        (flags & RTF_HOST)?(ifa->ifa_dstaddr):(ifa->ifa_addr),
        (struct sockaddr *) &mask, flags, NULL));
}

static int
aa_claim_addr(struct ifaddr *ifa, struct sockaddr *gw0)
{
        struct sockaddr_at *addr = (struct sockaddr_at *)ifa->ifa_addr;
        struct sockaddr_at *gw = (struct sockaddr_at *)gw0;

        switch (gw->sat_range.r_netrange.nr_phase) {
        case 1:
                if(addr->sat_range.r_netrange.nr_phase == 1)
                        return 1;
        case 0:
        case 2:
                /*
                 * if it's our net (including 0),
                 * or netranges are valid, and we are in the range,
                 * then it's ours.
                 */
                if ((addr->sat_addr.s_net == gw->sat_addr.s_net)
                || ((addr->sat_range.r_netrange.nr_lastnet)
                  && (ntohs(gw->sat_addr.s_net)
                        >= ntohs(addr->sat_range.r_netrange.nr_firstnet ))
                  && (ntohs(gw->sat_addr.s_net)
                        <= ntohs(addr->sat_range.r_netrange.nr_lastnet )))) {
                        return 1;
                } 
                break;
        default:
                kprintf("atalk: bad phase\n");
        }
        return 0;
}