Install dma(8) config files with mode 640 as root:mail to prevent ``normal''

[dragonfly.git] / sys / netinet / in.c

/*
 * Copyright (c) 1982, 1986, 1991, 1993
 *      The 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.
 *
 *      @(#)in.c        8.4 (Berkeley) 1/9/95
 * $FreeBSD: src/sys/netinet/in.c,v 1.44.2.14 2002/11/08 00:45:50 suz Exp $
 * $DragonFly: src/sys/netinet/in.c,v 1.25 2008/01/03 11:41:05 sephe Exp $
 */

#include "opt_bootp.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/thread2.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_pcb.h>

#include <netinet/igmp_var.h>

MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address");

static int in_mask2len (struct in_addr *);
static void in_len2mask (struct in_addr *, int);
static int in_lifaddr_ioctl (struct socket *, u_long, caddr_t,
        struct ifnet *, struct thread *);

static void     in_socktrim (struct sockaddr_in *);
static int      in_ifinit (struct ifnet *,
            struct in_ifaddr *, struct sockaddr_in *, int);

static int subnetsarelocal = 0;
SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
        &subnetsarelocal, 0, "");

struct in_multihead in_multihead; /* XXX BSS initialization */

extern struct inpcbinfo ripcbinfo;
extern struct inpcbinfo udbinfo;

/*
 * Return 1 if an internet address is for a ``local'' host
 * (one to which we have a connection).  If subnetsarelocal
 * is true, this includes other subnets of the local net.
 * Otherwise, it includes only the directly-connected (sub)nets.
 */
int
in_localaddr(struct in_addr in)
{
        u_long i = ntohl(in.s_addr);
        struct in_ifaddr *ia;

        if (subnetsarelocal) {
                TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
                        if ((i & ia->ia_netmask) == ia->ia_net)
                                return (1);
        } else {
                TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
                        if ((i & ia->ia_subnetmask) == ia->ia_subnet)
                                return (1);
        }
        return (0);
}

/*
 * Determine whether an IP address is in a reserved set of addresses
 * that may not be forwarded, or whether datagrams to that destination
 * may be forwarded.
 */
int
in_canforward(struct in_addr in)
{
        u_long i = ntohl(in.s_addr);
        u_long net;

        if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
                return (0);
        if (IN_CLASSA(i)) {
                net = i & IN_CLASSA_NET;
                if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
                        return (0);
        }
        return (1);
}

/*
 * Trim a mask in a sockaddr
 */
static void
in_socktrim(struct sockaddr_in *ap)
{
    char *cplim = (char *) &ap->sin_addr;
    char *cp = (char *) (&ap->sin_addr + 1);

    ap->sin_len = 0;
    while (--cp >= cplim)
        if (*cp) {
            (ap)->sin_len = cp - (char *) (ap) + 1;
            break;
        }
}

static int
in_mask2len(struct in_addr *mask)
{
        int x, y;
        u_char *p;

        p = (u_char *)mask;
        for (x = 0; x < sizeof *mask; x++) {
                if (p[x] != 0xff)
                        break;
        }
        y = 0;
        if (x < sizeof *mask) {
                for (y = 0; y < 8; y++) {
                        if ((p[x] & (0x80 >> y)) == 0)
                                break;
                }
        }
        return x * 8 + y;
}

static void
in_len2mask(struct in_addr *mask, int len)
{
        int i;
        u_char *p;

        p = (u_char *)mask;
        bzero(mask, sizeof *mask);
        for (i = 0; i < len / 8; i++)
                p[i] = 0xff;
        if (len % 8)
                p[i] = (0xff00 >> (len % 8)) & 0xff;
}

static int in_interfaces;       /* number of external internet interfaces */

/*
 * Generic internet control operations (ioctl's).
 * Ifp is 0 if not an interface-specific ioctl.
 *
 * NOTE! td might be NULL.
 */
/* ARGSUSED */
int
in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
           struct thread *td)
{
        struct ifreq *ifr = (struct ifreq *)data;
        struct in_ifaddr *ia = 0, *iap;
        struct ifaddr *ifa;
        struct in_addr dst;
        struct in_ifaddr *oia;
        struct in_aliasreq *ifra = (struct in_aliasreq *)data;
        struct sockaddr_in oldaddr;
        int hostIsNew, iaIsNew, maskIsNew;
        int error = 0;

        iaIsNew = 0;

        switch (cmd) {
        case SIOCALIFADDR:
        case SIOCDLIFADDR:
                if (td && (error = suser(td)) != 0)
                        return error;
                /*fall through*/
        case SIOCGLIFADDR:
                if (!ifp)
                        return EINVAL;
                return in_lifaddr_ioctl(so, cmd, data, ifp, td);
        }

        /*
         * Find address for this interface, if it exists.
         *
         * If an alias address was specified, find that one instead of
         * the first one on the interface, if possible
         */
        if (ifp) {
                dst = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
                LIST_FOREACH(iap, INADDR_HASH(dst.s_addr), ia_hash)
                        if (iap->ia_ifp == ifp &&
                            iap->ia_addr.sin_addr.s_addr == dst.s_addr) {
                                ia = iap;
                                break;
                        }
                if (ia == NULL)
                        TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                                iap = ifatoia(ifa);
                                if (iap->ia_addr.sin_family == AF_INET) {
                                        ia = iap;
                                        break;
                                }
                        }
        }

        switch (cmd) {

        case SIOCAIFADDR:
        case SIOCDIFADDR:
                if (ifp == NULL)
                        return (EADDRNOTAVAIL);
                if (ifra->ifra_addr.sin_family == AF_INET) {
                        for (oia = ia; ia; ia = TAILQ_NEXT(ia, ia_link)) {
                                if (ia->ia_ifp == ifp  &&
                                    ia->ia_addr.sin_addr.s_addr ==
                                    ifra->ifra_addr.sin_addr.s_addr)
                                        break;
                        }
                        if ((ifp->if_flags & IFF_POINTOPOINT)
                            && (cmd == SIOCAIFADDR)
                            && (ifra->ifra_dstaddr.sin_addr.s_addr
                                == INADDR_ANY)) {
                                return EDESTADDRREQ;
                        }
                }
                if (cmd == SIOCDIFADDR && ia == NULL)
                        return (EADDRNOTAVAIL);
                /* FALLTHROUGH */
        case SIOCSIFADDR:
        case SIOCSIFNETMASK:
        case SIOCSIFDSTADDR:
                if (td && (error = suser(td)) != 0)
                        return error;

                if (ifp == NULL)
                        return (EADDRNOTAVAIL);
                if (ia == NULL) {
                        ia = kmalloc(sizeof *ia, M_IFADDR, M_WAITOK | M_ZERO);

                        /*
                         * Protect from NETISR_IP traversing address list
                         * while we're modifying it.
                         */
                        crit_enter();
                        
                        TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_link);
                        ifa = &ia->ia_ifa;
                        TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);

                        ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
                        ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
                        ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
                        ia->ia_sockmask.sin_len = 8;
                        ia->ia_sockmask.sin_family = AF_INET;
                        if (ifp->if_flags & IFF_BROADCAST) {
                                ia->ia_broadaddr.sin_len = sizeof ia->ia_addr;
                                ia->ia_broadaddr.sin_family = AF_INET;
                        }
                        ia->ia_ifp = ifp;
                        if (!(ifp->if_flags & IFF_LOOPBACK))
                                in_interfaces++;
                        iaIsNew = 1;
                        crit_exit();
                }
                break;

        case SIOCSIFBRDADDR:
                if (td && (error = suser(td)) != 0)
                        return error;
                /* FALLTHROUGH */

        case SIOCGIFADDR:
        case SIOCGIFNETMASK:
        case SIOCGIFDSTADDR:
        case SIOCGIFBRDADDR:
                if (ia == NULL)
                        return (EADDRNOTAVAIL);
                break;
        }
        switch (cmd) {

        case SIOCGIFADDR:
                *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
                return (0);

        case SIOCGIFBRDADDR:
                if ((ifp->if_flags & IFF_BROADCAST) == 0)
                        return (EINVAL);
                *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
                return (0);

        case SIOCGIFDSTADDR:
                if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
                        return (EINVAL);
                *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
                return (0);

        case SIOCGIFNETMASK:
                *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
                return (0);

        case SIOCSIFDSTADDR:
                if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
                        return (EINVAL);
                oldaddr = ia->ia_dstaddr;
                ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
                lwkt_serialize_enter(ifp->if_serializer);
                if (ifp->if_ioctl &&
                    (error = ifp->if_ioctl(ifp, SIOCSIFDSTADDR, (caddr_t)ia,
                                              td->td_proc->p_ucred))) {
                        ia->ia_dstaddr = oldaddr;
                        lwkt_serialize_exit(ifp->if_serializer);
                        return (error);
                }
                if (ia->ia_flags & IFA_ROUTE) {
                        ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
                        rtinit(&ia->ia_ifa, RTM_DELETE, RTF_HOST);
                        ia->ia_ifa.ifa_dstaddr =
                                        (struct sockaddr *)&ia->ia_dstaddr;
                        rtinit(&ia->ia_ifa, RTM_ADD, RTF_HOST | RTF_UP);
                }
                lwkt_serialize_exit(ifp->if_serializer);
                return (0);

        case SIOCSIFBRDADDR:
                if ((ifp->if_flags & IFF_BROADCAST) == 0)
                        return (EINVAL);
                ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
                return (0);

        case SIOCSIFADDR:
                error = in_ifinit(ifp, ia,
                    (struct sockaddr_in *) &ifr->ifr_addr, 1);
                if (error != 0 && iaIsNew)
                        break;
                if (error == 0)
                        EVENTHANDLER_INVOKE(ifaddr_event, ifp);
                return (0);

        case SIOCSIFNETMASK:
                ia->ia_sockmask.sin_addr = ifra->ifra_addr.sin_addr;
                ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
                return (0);

        case SIOCAIFADDR:
                maskIsNew = 0;
                hostIsNew = 1;
                error = 0;
                if (ia->ia_addr.sin_family == AF_INET) {
                        if (ifra->ifra_addr.sin_len == 0) {
                                ifra->ifra_addr = ia->ia_addr;
                                hostIsNew = 0;
                        } else if (ifra->ifra_addr.sin_addr.s_addr ==
                                               ia->ia_addr.sin_addr.s_addr)
                                hostIsNew = 0;
                }
                if (ifra->ifra_mask.sin_len) {
                        in_ifscrub(ifp, ia);
                        ia->ia_sockmask = ifra->ifra_mask;
                        ia->ia_sockmask.sin_family = AF_INET;
                        ia->ia_subnetmask =
                             ntohl(ia->ia_sockmask.sin_addr.s_addr);
                        maskIsNew = 1;
                }
                if ((ifp->if_flags & IFF_POINTOPOINT) &&
                    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
                        in_ifscrub(ifp, ia);
                        ia->ia_dstaddr = ifra->ifra_dstaddr;
                        maskIsNew  = 1; /* We lie; but the effect's the same */
                }
                if (ifra->ifra_addr.sin_family == AF_INET &&
                    (hostIsNew || maskIsNew))
                        error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);

                if (error != 0 && iaIsNew)
                        break;

                if ((ifp->if_flags & IFF_BROADCAST) &&
                    (ifra->ifra_broadaddr.sin_family == AF_INET))
                        ia->ia_broadaddr = ifra->ifra_broadaddr;
                if (error == 0)
                        EVENTHANDLER_INVOKE(ifaddr_event, ifp);
                return (error);

        case SIOCDIFADDR:
                /*
                 * in_ifscrub kills the interface route.
                 */
                in_ifscrub(ifp, ia);
                /*
                 * in_ifadown gets rid of all the rest of
                 * the routes.  This is not quite the right
                 * thing to do, but at least if we are running
                 * a routing process they will come back.
                 */
                in_ifadown(&ia->ia_ifa, 1);
                EVENTHANDLER_INVOKE(ifaddr_event, ifp);
                error = 0;
                break;

        default:
                if (ifp == NULL || ifp->if_ioctl == NULL)
                        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);
        }

        /*
         * Protect from NETISR_IP traversing address list while we're modifying
         * it.
         */
        lwkt_serialize_enter(ifp->if_serializer);
        TAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
        TAILQ_REMOVE(&in_ifaddrhead, ia, ia_link);
        LIST_REMOVE(ia, ia_hash);
        IFAFREE(&ia->ia_ifa);
        lwkt_serialize_exit(ifp->if_serializer);

        return (error);
}

/*
 * SIOC[GAD]LIFADDR.
 *      SIOCGLIFADDR: get first address. (?!?)
 *      SIOCGLIFADDR with IFLR_PREFIX:
 *              get first address that matches the specified prefix.
 *      SIOCALIFADDR: add the specified address.
 *      SIOCALIFADDR with IFLR_PREFIX:
 *              EINVAL since we can't deduce hostid part of the address.
 *      SIOCDLIFADDR: delete the specified address.
 *      SIOCDLIFADDR with IFLR_PREFIX:
 *              delete the first address that matches the specified prefix.
 * return values:
 *      EINVAL on invalid parameters
 *      EADDRNOTAVAIL on prefix match failed/specified address not found
 *      other values may be returned from in_ioctl()
 *
 * NOTE! td might be NULL.
 */
static int
in_lifaddr_ioctl(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
                 struct thread *td)
{
        struct if_laddrreq *iflr = (struct if_laddrreq *)data;
        struct ifaddr *ifa;

        /* sanity checks */
        if (!data || !ifp) {
                panic("invalid argument to in_lifaddr_ioctl");
                /*NOTRECHED*/
        }

        switch (cmd) {
        case SIOCGLIFADDR:
                /* address must be specified on GET with IFLR_PREFIX */
                if ((iflr->flags & IFLR_PREFIX) == 0)
                        break;
                /*FALLTHROUGH*/
        case SIOCALIFADDR:
        case SIOCDLIFADDR:
                /* address must be specified on ADD and DELETE */
                if (iflr->addr.ss_family != AF_INET)
                        return EINVAL;
                if (iflr->addr.ss_len != sizeof(struct sockaddr_in))
                        return EINVAL;
                /* XXX need improvement */
                if (iflr->dstaddr.ss_family
                 && iflr->dstaddr.ss_family != AF_INET)
                        return EINVAL;
                if (iflr->dstaddr.ss_family
                 && iflr->dstaddr.ss_len != sizeof(struct sockaddr_in))
                        return EINVAL;
                break;
        default: /*shouldn't happen*/
                return EOPNOTSUPP;
        }
        if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
                return EINVAL;

        switch (cmd) {
        case SIOCALIFADDR:
            {
                struct in_aliasreq ifra;

                if (iflr->flags & IFLR_PREFIX)
                        return EINVAL;

                /* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
                bzero(&ifra, sizeof ifra);
                bcopy(iflr->iflr_name, ifra.ifra_name, sizeof ifra.ifra_name);

                bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.ss_len);

                if (iflr->dstaddr.ss_family) {  /*XXX*/
                        bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
                                iflr->dstaddr.ss_len);
                }

                ifra.ifra_mask.sin_family = AF_INET;
                ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
                in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);

                return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, td);
            }
        case SIOCGLIFADDR:
        case SIOCDLIFADDR:
            {
                struct in_ifaddr *ia;
                struct in_addr mask, candidate, match;
                struct sockaddr_in *sin;
                int cmp;

                bzero(&mask, sizeof mask);
                if (iflr->flags & IFLR_PREFIX) {
                        /* lookup a prefix rather than address. */
                        in_len2mask(&mask, iflr->prefixlen);

                        sin = (struct sockaddr_in *)&iflr->addr;
                        match.s_addr = sin->sin_addr.s_addr;
                        match.s_addr &= mask.s_addr;

                        /* if you set extra bits, that's wrong */
                        if (match.s_addr != sin->sin_addr.s_addr)
                                return EINVAL;

                        cmp = 1;
                } else {
                        if (cmd == SIOCGLIFADDR) {
                                /* on getting an address, take the 1st match */
                                match.s_addr = 0; /* gcc4 warning */
                                cmp = 0;        /*XXX*/
                        } else {
                                /* on deleting an address, do exact match */
                                in_len2mask(&mask, 32);
                                sin = (struct sockaddr_in *)&iflr->addr;
                                match.s_addr = sin->sin_addr.s_addr;

                                cmp = 1;
                        }
                }

                TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                        if (ifa->ifa_addr->sa_family != AF_INET6)
                                continue;
                        if (!cmp)
                                break;
                        candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
                        candidate.s_addr &= mask.s_addr;
                        if (candidate.s_addr == match.s_addr)
                                break;
                }
                if (!ifa)
                        return EADDRNOTAVAIL;
                ia = (struct in_ifaddr *)ifa;

                if (cmd == SIOCGLIFADDR) {
                        /* fill in the if_laddrreq structure */
                        bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);

                        if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
                                bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
                                        ia->ia_dstaddr.sin_len);
                        } else
                                bzero(&iflr->dstaddr, sizeof iflr->dstaddr);

                        iflr->prefixlen =
                                in_mask2len(&ia->ia_sockmask.sin_addr);

                        iflr->flags = 0;        /*XXX*/

                        return 0;
                } else {
                        struct in_aliasreq ifra;

                        /* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
                        bzero(&ifra, sizeof ifra);
                        bcopy(iflr->iflr_name, ifra.ifra_name,
                                sizeof ifra.ifra_name);

                        bcopy(&ia->ia_addr, &ifra.ifra_addr,
                                ia->ia_addr.sin_len);
                        if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
                                bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
                                        ia->ia_dstaddr.sin_len);
                        }
                        bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
                                ia->ia_sockmask.sin_len);

                        return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
                                          ifp, td);
                }
            }
        }

        return EOPNOTSUPP;      /*just for safety*/
}

/*
 * Delete any existing route for an interface.
 */
void
in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia)
{

        if ((ia->ia_flags & IFA_ROUTE) == 0)
                return;
        if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
                rtinit(&ia->ia_ifa, RTM_DELETE, RTF_HOST);
        else
                rtinit(&ia->ia_ifa, RTM_DELETE, 0);
        ia->ia_flags &= ~IFA_ROUTE;
}

/*
 * Initialize an interface's internet address
 * and routing table entry.
 */
static int
in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia, struct sockaddr_in *sin, int scrub)
{
        u_long i = ntohl(sin->sin_addr.s_addr);
        struct sockaddr_in oldaddr;
        int flags = RTF_UP, error = 0;

        lwkt_serialize_enter(ifp->if_serializer);

        oldaddr = ia->ia_addr;
        if (oldaddr.sin_family == AF_INET)
                LIST_REMOVE(ia, ia_hash);
        ia->ia_addr = *sin;
        if (ia->ia_addr.sin_family == AF_INET)
                LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
                    ia, ia_hash);
        /*
         * Give the interface a chance to initialize
         * if this is its first address,
         * and to validate the address if necessary.
         */
        if (ifp->if_ioctl &&
            (error = ifp->if_ioctl(ifp, SIOCSIFADDR, (caddr_t)ia, NULL))) {
                lwkt_serialize_exit(ifp->if_serializer);
                /* LIST_REMOVE(ia, ia_hash) is done in in_control */
                ia->ia_addr = oldaddr;
                if (ia->ia_addr.sin_family == AF_INET)
                        LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
                            ia, ia_hash);
                return (error);
        }
        lwkt_serialize_exit(ifp->if_serializer);
        if (scrub) {
                ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
                in_ifscrub(ifp, ia);
                ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
        }
        if (IN_CLASSA(i))
                ia->ia_netmask = IN_CLASSA_NET;
        else if (IN_CLASSB(i))
                ia->ia_netmask = IN_CLASSB_NET;
        else
                ia->ia_netmask = IN_CLASSC_NET;
        /*
         * The subnet mask usually includes at least the standard network part,
         * but may may be smaller in the case of supernetting.
         * If it is set, we believe it.
         */
        if (ia->ia_subnetmask == 0) {
                ia->ia_subnetmask = ia->ia_netmask;
                ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
        } else
                ia->ia_netmask &= ia->ia_subnetmask;
        ia->ia_net = i & ia->ia_netmask;
        ia->ia_subnet = i & ia->ia_subnetmask;
        in_socktrim(&ia->ia_sockmask);
        /*
         * Add route for the network.
         */
        ia->ia_ifa.ifa_metric = ifp->if_metric;
        if (ifp->if_flags & IFF_BROADCAST) {
                ia->ia_broadaddr.sin_addr.s_addr =
                        htonl(ia->ia_subnet | ~ia->ia_subnetmask);
                ia->ia_netbroadcast.s_addr =
                        htonl(ia->ia_net | ~ ia->ia_netmask);
        } else if (ifp->if_flags & IFF_LOOPBACK) {
                ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
                flags |= RTF_HOST;
        } else if (ifp->if_flags & IFF_POINTOPOINT) {
                if (ia->ia_dstaddr.sin_family != AF_INET)
                        return (0);
                flags |= RTF_HOST;
        }

        /*-
         * Don't add host routes for interface addresses of
         * 0.0.0.0 --> 0.255.255.255 netmask 255.0.0.0.  This makes it
         * possible to assign several such address pairs with consistent
         * results (no host route) and is required by BOOTP.
         *
         * XXX: This is ugly !  There should be a way for the caller to
         *      say that they don't want a host route.
         */
        if (ia->ia_addr.sin_addr.s_addr != INADDR_ANY ||
            ia->ia_netmask != IN_CLASSA_NET ||
            ia->ia_dstaddr.sin_addr.s_addr != htonl(IN_CLASSA_HOST)) {
                if ((error = rtinit(&ia->ia_ifa, (int)RTM_ADD, flags)) != 0) {
                        ia->ia_addr = oldaddr;
                        return (error);
                }
                ia->ia_flags |= IFA_ROUTE;
        }

        /*
         * If the interface supports multicast, join the "all hosts"
         * multicast group on that interface.
         */
        if (ifp->if_flags & IFF_MULTICAST) {
                struct in_addr addr;

                addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
                in_addmulti(&addr, ifp);
        }
        return (error);
}


/*
 * Return 1 if the address might be a local broadcast address.
 */
int
in_broadcast(struct in_addr in, struct ifnet *ifp)
{
        struct ifaddr *ifa;
        u_long t;

        if (in.s_addr == INADDR_BROADCAST ||
            in.s_addr == INADDR_ANY)
                return 1;
        if ((ifp->if_flags & IFF_BROADCAST) == 0)
                return 0;
        t = ntohl(in.s_addr);
        /*
         * Look through the list of addresses for a match
         * with a broadcast address.
         */
#define ia ((struct in_ifaddr *)ifa)
        TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
                if (ifa->ifa_addr->sa_family == AF_INET &&
                    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
                     in.s_addr == ia->ia_netbroadcast.s_addr ||
                     /*
                      * Check for old-style (host 0) broadcast.
                      */
                     t == ia->ia_subnet || t == ia->ia_net) &&
                     /*
                      * Check for an all one subnetmask. These
                      * only exist when an interface gets a secondary
                      * address.
                      */
                     ia->ia_subnetmask != (u_long)0xffffffff)
                            return 1;
        return (0);
#undef ia
}
/*
 * Add an address to the list of IP multicast addresses for a given interface.
 */
struct in_multi *
in_addmulti(struct in_addr *ap, struct ifnet *ifp)
{
        struct in_multi *inm;
        int error;
        struct sockaddr_in sin;
        struct ifmultiaddr *ifma;

        /*
         * Call generic routine to add membership or increment
         * refcount.  It wants addresses in the form of a sockaddr,
         * so we build one here (being careful to zero the unused bytes).
         */
        bzero(&sin, sizeof sin);
        sin.sin_family = AF_INET;
        sin.sin_len = sizeof sin;
        sin.sin_addr = *ap;
        crit_enter();
        error = if_addmulti(ifp, (struct sockaddr *)&sin, &ifma);
        if (error) {
                crit_exit();
                return 0;
        }

        /*
         * If ifma->ifma_protospec is null, then if_addmulti() created
         * a new record.  Otherwise, we are done.
         */
        if (ifma->ifma_protospec != 0) {
                crit_exit();
                return ifma->ifma_protospec;
        }

        /* XXX - if_addmulti uses M_WAITOK.  Can this really be called
           at interrupt time?  If so, need to fix if_addmulti. XXX */
        inm = kmalloc(sizeof *inm, M_IPMADDR, M_WAITOK | M_ZERO);
        inm->inm_addr = *ap;
        inm->inm_ifp = ifp;
        inm->inm_ifma = ifma;
        ifma->ifma_protospec = inm;
        LIST_INSERT_HEAD(&in_multihead, inm, inm_link);

        /*
         * Let IGMP know that we have joined a new IP multicast group.
         */
        igmp_joingroup(inm);
        crit_exit();
        return (inm);
}

/*
 * Delete a multicast address record.
 */
void
in_delmulti(struct in_multi *inm)
{
        struct ifmultiaddr *ifma;
        struct in_multi my_inm;

        crit_enter();
        ifma = inm->inm_ifma;
        my_inm.inm_ifp = NULL ; /* don't send the leave msg */
        if (ifma->ifma_refcount == 1) {
                /*
                 * No remaining claims to this record; let IGMP know that
                 * we are leaving the multicast group.
                 * But do it after the if_delmulti() which might reset
                 * the interface and nuke the packet.
                 */
                my_inm = *inm ;
                ifma->ifma_protospec = 0;
                LIST_REMOVE(inm, inm_link);
                kfree(inm, M_IPMADDR);
        }
        /* XXX - should be separate API for when we have an ifma? */
        if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
        if (my_inm.inm_ifp != NULL)
                igmp_leavegroup(&my_inm);
        crit_exit();
}

void
in_ifdetach(struct ifnet *ifp)
{
        in_pcbpurgeif0(LIST_FIRST(&ripcbinfo.pcblisthead), ifp);
        in_pcbpurgeif0(LIST_FIRST(&udbinfo.pcblisthead), ifp);
}