xnu-344.tar.gz

[apple/xnu.git] / bsd / net / rtsock.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1988, 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.
 *
 *      @(#)rtsock.c    8.5 (Berkeley) 11/2/94
 */


#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/syslog.h>

#include <net/if.h>
#include <net/route.h>
#include <net/raw_cb.h>
#include <netinet/in.h>

MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables");

static struct   sockaddr route_dst = { 2, PF_ROUTE, };
static struct   sockaddr route_src = { 2, PF_ROUTE, };
static struct   sockaddr sa_zero   = { sizeof(sa_zero), AF_INET, };
static struct   sockproto route_proto = { PF_ROUTE, };

struct walkarg {
        int     w_tmemsize;
        int     w_op, w_arg;
        caddr_t w_tmem;
        struct sysctl_req *w_req;
};

static struct mbuf *
                rt_msg1 __P((int, struct rt_addrinfo *));
static int      rt_msg2 __P((int,
                    struct rt_addrinfo *, caddr_t, struct walkarg *));
static int      rt_xaddrs __P((caddr_t, caddr_t, struct rt_addrinfo *));
static int      sysctl_dumpentry __P((struct radix_node *rn, void *vw));
static int      sysctl_iflist __P((int af, struct walkarg *w));
static int       route_output __P((struct mbuf *, struct socket *));
static void      rt_setmetrics __P((u_long, struct rt_metrics *, struct rt_metrics *));
static void     rt_setif __P((struct rtentry *, struct sockaddr *, struct sockaddr *,
                              struct sockaddr *));

/* Sleazy use of local variables throughout file, warning!!!! */
#define dst     info.rti_info[RTAX_DST]
#define gate    info.rti_info[RTAX_GATEWAY]
#define netmask info.rti_info[RTAX_NETMASK]
#define genmask info.rti_info[RTAX_GENMASK]
#define ifpaddr info.rti_info[RTAX_IFP]
#define ifaaddr info.rti_info[RTAX_IFA]
#define brdaddr info.rti_info[RTAX_BRD]

/*
 * It really doesn't make any sense at all for this code to share much
 * with raw_usrreq.c, since its functionality is so restricted.  XXX
 */
static int
rts_abort(struct socket *so)
{
        int s, error;
        s = splnet();
        error = raw_usrreqs.pru_abort(so);
        splx(s);
        return error;
}

/* pru_accept is EOPNOTSUPP */

static int
rts_attach(struct socket *so, int proto, struct proc *p)
{
        struct rawcb *rp;
        int s, error;

        if (sotorawcb(so) != 0)
                return EISCONN; /* XXX panic? */
        MALLOC(rp, struct rawcb *, sizeof *rp, M_PCB, M_WAITOK); /* XXX */
        if (rp == 0)
                return ENOBUFS;
        bzero(rp, sizeof *rp);

        /*
         * The splnet() is necessary to block protocols from sending
         * error notifications (like RTM_REDIRECT or RTM_LOSING) while
         * this PCB is extant but incompletely initialized.
         * Probably we should try to do more of this work beforehand and
         * eliminate the spl.
         */
        s = splnet();
        so->so_pcb = (caddr_t)rp;
        error = raw_usrreqs.pru_attach(so, proto, p);
        rp = sotorawcb(so);
        if (error) {
                splx(s);
                FREE(rp, M_PCB);
                return error;
        }
        switch(rp->rcb_proto.sp_protocol) {
        case AF_INET:
                route_cb.ip_count++;
                break;
        case AF_INET6:
                route_cb.ip6_count++;
                break;
        case AF_IPX:
                route_cb.ipx_count++;
                break;
        case AF_NS:
                route_cb.ns_count++;
                break;
        }
        rp->rcb_faddr = &route_src;
        route_cb.any_count++;
        soisconnected(so);
        so->so_options |= SO_USELOOPBACK;
        splx(s);
        return 0;
}

static int
rts_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
{
        int s, error;
        s = splnet();
        error = raw_usrreqs.pru_bind(so, nam, p); /* xxx just EINVAL */
        splx(s);
        return error;
}

static int
rts_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
{
        int s, error;
        s = splnet();
        error = raw_usrreqs.pru_connect(so, nam, p); /* XXX just EINVAL */
        splx(s);
        return error;
}

/* pru_connect2 is EOPNOTSUPP */
/* pru_control is EOPNOTSUPP */

static int
rts_detach(struct socket *so)
{
        struct rawcb *rp = sotorawcb(so);
        int s, error;

        s = splnet();
        if (rp != 0) {
                switch(rp->rcb_proto.sp_protocol) {
                case AF_INET:
                        route_cb.ip_count--;
                        break;
                case AF_INET6:
                        route_cb.ip6_count--;
                        break;
                case AF_IPX:
                        route_cb.ipx_count--;
                        break;
                case AF_NS:
                        route_cb.ns_count--;
                        break;
                }
                route_cb.any_count--;
        }
        error = raw_usrreqs.pru_detach(so);
        splx(s);
        return error;
}

static int
rts_disconnect(struct socket *so)
{
        int s, error;
        s = splnet();
        error = raw_usrreqs.pru_disconnect(so);
        splx(s);
        return error;
}

/* pru_listen is EOPNOTSUPP */

static int
rts_peeraddr(struct socket *so, struct sockaddr **nam)
{
        int s, error;
        s = splnet();
        error = raw_usrreqs.pru_peeraddr(so, nam);
        splx(s);
        return error;
}

/* pru_rcvd is EOPNOTSUPP */
/* pru_rcvoob is EOPNOTSUPP */

static int
rts_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
         struct mbuf *control, struct proc *p)
{
        int s, error;
        s = splnet();
        error = raw_usrreqs.pru_send(so, flags, m, nam, control, p);
        splx(s);
        return error;
}

/* pru_sense is null */

static int
rts_shutdown(struct socket *so)
{
        int s, error;
        s = splnet();
        error = raw_usrreqs.pru_shutdown(so);
        splx(s);
        return error;
}

static int
rts_sockaddr(struct socket *so, struct sockaddr **nam)
{
        int s, error;
        s = splnet();
        error = raw_usrreqs.pru_sockaddr(so, nam);
        splx(s);
        return error;
}

static struct pr_usrreqs route_usrreqs = {
        rts_abort, pru_accept_notsupp, rts_attach, rts_bind, rts_connect,
        pru_connect2_notsupp, pru_control_notsupp, rts_detach, rts_disconnect,
        pru_listen_notsupp, rts_peeraddr, pru_rcvd_notsupp, pru_rcvoob_notsupp,
        rts_send, pru_sense_null, rts_shutdown, rts_sockaddr,
        sosend, soreceive, sopoll
};

/*ARGSUSED*/
static int
route_output(m, so)
        register struct mbuf *m;
        struct socket *so;
{
        register struct rt_msghdr *rtm = 0;
        register struct rtentry *rt = 0;
        struct rtentry *saved_nrt = 0;
        struct radix_node_head *rnh;
        struct rt_addrinfo info;
        int len, error = 0;
        struct ifnet *ifp = 0;
        struct ifaddr *ifa = 0;
        struct proc  *curproc = current_proc();

#define senderr(e) { error = e; goto flush;}
        if (m == 0 || ((m->m_len < sizeof(long)) &&
                       (m = m_pullup(m, sizeof(long))) == 0))
                return (ENOBUFS);
        if ((m->m_flags & M_PKTHDR) == 0)
                panic("route_output");
        len = m->m_pkthdr.len;
        if (len < sizeof(*rtm) ||
            len != mtod(m, struct rt_msghdr *)->rtm_msglen) {
                dst = 0;
                senderr(EINVAL);
        }
        R_Malloc(rtm, struct rt_msghdr *, len);
        if (rtm == 0) {
                dst = 0;
                senderr(ENOBUFS);
        }
        m_copydata(m, 0, len, (caddr_t)rtm);
        if (rtm->rtm_version != RTM_VERSION) {
                dst = 0;
                senderr(EPROTONOSUPPORT);
        }
        rtm->rtm_pid = curproc->p_pid;
        info.rti_addrs = rtm->rtm_addrs;
        if (rt_xaddrs((caddr_t)(rtm + 1), len + (caddr_t)rtm, &info)) {
                dst = 0;
                senderr(EINVAL);
        }
        if (dst == 0 || (dst->sa_family >= AF_MAX)
            || (gate != 0 && (gate->sa_family >= AF_MAX)))
                senderr(EINVAL);
        if (genmask) {
                struct radix_node *t;
                t = rn_addmask((caddr_t)genmask, 0, 1);
                if (t && Bcmp(genmask, t->rn_key, *(u_char *)genmask) == 0)
                        genmask = (struct sockaddr *)(t->rn_key);
                else
                        senderr(ENOBUFS);
        }
        switch (rtm->rtm_type) {

        case RTM_ADD:
                if (gate == 0)
                        senderr(EINVAL);

#ifdef __APPLE__
/* XXX LD11JUL02 Special case for AOL 5.1.2 connectivity issue to AirPort BS (Radar 2969954)
 * AOL is adding a circular route ("10.0.1.1/32 10.0.1.1") when establishing its ppp tunnel
 * to the AP BaseStation by removing the default gateway and replacing it with their tunnel entry point.
 * There is no apparent reason to add this route as there is a valid 10.0.1.1/24 route to the BS.
 * That circular route was ignored on previous version of MacOS X because of a routing bug
 * corrected with the merge to FreeBSD4.4 (a route generated from an RTF_CLONING route had the RTF_WASCLONED
 * flag set but did not have a reference to the parent route) and that entry was left in the RT. This workaround is
 * made in order to provide binary compatibility with AOL. 
 * If we catch a process adding a circular route with a /32 from the routing socket, we error it out instead of
 * confusing the routing table with a wrong route to the previous default gateway
 */
{
                extern int check_routeselfref;
#define satosinaddr(sa) (((struct sockaddr_in *)sa)->sin_addr.s_addr)

                if (check_routeselfref && (dst && dst->sa_family == AF_INET) && 
                        (netmask && satosinaddr(netmask) == INADDR_BROADCAST) &&
                        (gate && satosinaddr(dst) == satosinaddr(gate))) {
                                log(LOG_WARNING, "route_output: circular route %ld.%ld.%ld.%ld/32 ignored\n",
                                        (ntohl(satosinaddr(gate)>>24))&0xff,
                                        (ntohl(satosinaddr(gate)>>16))&0xff,
                                        (ntohl(satosinaddr(gate)>>8))&0xff,
                                        (ntohl(satosinaddr(gate)))&0xff);
                                        
                                senderr(EINVAL);
                }
}
#endif  
                error = rtrequest(RTM_ADD, dst, gate, netmask,
                                        rtm->rtm_flags, &saved_nrt);
                if (error == 0 && saved_nrt) {
#ifdef __APPLE__
                    /* 
                     * If the route request specified an interface with
                     * IFA and/or IFP, we set the requested interface on
                     * the route with rt_setif.  It would be much better
                     * to do this inside rtrequest, but that would
                     * require passing the desired interface, in some
                     * form, to rtrequest.  Since rtrequest is called in
                     * so many places (roughly 40 in our source), adding
                     * a parameter is to much for us to swallow; this is
                     * something for the FreeBSD developers to tackle.
                     * Instead, we let rtrequest compute whatever
                     * interface it wants, then come in behind it and
                     * stick in the interface that we really want.  This
                     * works reasonably well except when rtrequest can't
                     * figure out what interface to use (with
                     * ifa_withroute) and returns ENETUNREACH.  Ideally
                     * it shouldn't matter if rtrequest can't figure out
                     * the interface if we're going to explicitly set it
                     * ourselves anyway.  But practically we can't
                     * recover here because rtrequest will not do any of
                     * the work necessary to add the route if it can't
                     * find an interface.  As long as there is a default
                     * route that leads to some interface, rtrequest will
                     * find an interface, so this problem should be
                     * rarely encountered.
                     * dwiggins@bbn.com
                     */

                        rt_setif(saved_nrt, ifpaddr, ifaaddr, gate);
#endif
                        rt_setmetrics(rtm->rtm_inits,
                                &rtm->rtm_rmx, &saved_nrt->rt_rmx);
                        saved_nrt->rt_rmx.rmx_locks &= ~(rtm->rtm_inits);
                        saved_nrt->rt_rmx.rmx_locks |=
                                (rtm->rtm_inits & rtm->rtm_rmx.rmx_locks);
                        rtunref(saved_nrt);
                        saved_nrt->rt_genmask = genmask;
                }
                break;

        case RTM_DELETE:
                error = rtrequest(RTM_DELETE, dst, gate, netmask,
                                rtm->rtm_flags, &saved_nrt);
                if (error == 0) {
                        if ((rt = saved_nrt))
                                rtref(rt);
                        goto report;
                }
                break;

        case RTM_GET:
        case RTM_CHANGE:
        case RTM_LOCK:
                if ((rnh = rt_tables[dst->sa_family]) == 0) {
                        senderr(EAFNOSUPPORT);
                } else if ((rt = (struct rtentry *)
                                rnh->rnh_lookup(dst, netmask, rnh)) != NULL)
                        rtref(rt);
                else
                        senderr(ESRCH);
                switch(rtm->rtm_type) {

                case RTM_GET:
                report:
                        dst = rt_key(rt);
                        gate = rt->rt_gateway;
                        netmask = rt_mask(rt);
                        genmask = rt->rt_genmask;
                        if (rtm->rtm_addrs & (RTA_IFP | RTA_IFA)) {
                                ifp = rt->rt_ifp;
                                if (ifp) {
                                        ifpaddr = ifp->if_addrhead.tqh_first->ifa_addr;
                                        ifaaddr = rt->rt_ifa->ifa_addr;
                                        rtm->rtm_index = ifp->if_index;
                                } else {
                                        ifpaddr = 0;
                                        ifaaddr = 0;
                            }
                        }
                        len = rt_msg2(rtm->rtm_type, &info, (caddr_t)0,
                                (struct walkarg *)0);
                        if (len > rtm->rtm_msglen) {
                                struct rt_msghdr *new_rtm;
                                R_Malloc(new_rtm, struct rt_msghdr *, len);
                                if (new_rtm == 0)
                                        senderr(ENOBUFS);
                                Bcopy(rtm, new_rtm, rtm->rtm_msglen);
                                Free(rtm); rtm = new_rtm;
                        }
                        (void)rt_msg2(rtm->rtm_type, &info, (caddr_t)rtm,
                                (struct walkarg *)0);
                        rtm->rtm_flags = rt->rt_flags;
                        rtm->rtm_rmx = rt->rt_rmx;
                        rtm->rtm_addrs = info.rti_addrs;
                        break;

                case RTM_CHANGE:
                        if (gate && (error = rt_setgate(rt, rt_key(rt), gate)))
                                senderr(error);

                        /*
                         * If they tried to change things but didn't specify
                         * the required gateway, then just use the old one.
                         * This can happen if the user tries to change the
                         * flags on the default route without changing the
                         * default gateway.  Changing flags still doesn't work.
                         */
                        if ((rt->rt_flags & RTF_GATEWAY) && !gate)
                                gate = rt->rt_gateway;

#ifdef __APPLE__
                        /*
                         * On Darwin, we call rt_setif which contains the
                         * equivalent to the code found at this very spot
                         * in BSD.
                         */
                        rt_setif(rt, ifpaddr, ifaaddr, gate);
#endif

                        rt_setmetrics(rtm->rtm_inits, &rtm->rtm_rmx,
                                        &rt->rt_rmx);
#ifndef __APPLE__
                        /* rt_setif, called above does this for us on darwin */
                        if (rt->rt_ifa && rt->rt_ifa->ifa_rtrequest)
                               rt->rt_ifa->ifa_rtrequest(RTM_ADD, rt, gate);
#endif
                        if (genmask)
                                rt->rt_genmask = genmask;
                        /*
                         * Fall into
                         */
                case RTM_LOCK:
                        rt->rt_rmx.rmx_locks &= ~(rtm->rtm_inits);
                        rt->rt_rmx.rmx_locks |=
                                (rtm->rtm_inits & rtm->rtm_rmx.rmx_locks);
                        break;
                }
                break;

        default:
                senderr(EOPNOTSUPP);
        }

flush:
        if (rtm) {
                if (error)
                        rtm->rtm_errno = error;
                else
                        rtm->rtm_flags |= RTF_DONE;
        }
        if (rt)
                rtfree(rt);
    {
        register struct rawcb *rp = 0;
        /*
         * Check to see if we don't want our own messages.
         */
        if ((so->so_options & SO_USELOOPBACK) == 0) {
                if (route_cb.any_count <= 1) {
                        if (rtm)
                                Free(rtm);
                        m_freem(m);
                        return (error);
                }
                /* There is another listener, so construct message */
                rp = sotorawcb(so);
        }
        if (rtm) {
                m_copyback(m, 0, rtm->rtm_msglen, (caddr_t)rtm);
                if (m->m_pkthdr.len < rtm->rtm_msglen) {
                        m_freem(m);
                        m = NULL;
                } else if (m->m_pkthdr.len > rtm->rtm_msglen)
                        m_adj(m, rtm->rtm_msglen - m->m_pkthdr.len);
                Free(rtm);
        }
        if (rp)
                rp->rcb_proto.sp_family = 0; /* Avoid us */
        if (dst)
                route_proto.sp_protocol = dst->sa_family;
        if (m)
                raw_input(m, &route_proto, &route_src, &route_dst);
        if (rp)
                rp->rcb_proto.sp_family = PF_ROUTE;
    }
        return (error);
}

static void
rt_setmetrics(which, in, out)
        u_long which;
        register struct rt_metrics *in, *out;
{
#define metric(f, e) if (which & (f)) out->e = in->e;
        metric(RTV_RPIPE, rmx_recvpipe);
        metric(RTV_SPIPE, rmx_sendpipe);
        metric(RTV_SSTHRESH, rmx_ssthresh);
        metric(RTV_RTT, rmx_rtt);
        metric(RTV_RTTVAR, rmx_rttvar);
        metric(RTV_HOPCOUNT, rmx_hopcount);
        metric(RTV_MTU, rmx_mtu);
        metric(RTV_EXPIRE, rmx_expire);
#undef metric
}

/*
 * Set route's interface given ifpaddr, ifaaddr, and gateway.
 */
static void
rt_setif(rt, Ifpaddr, Ifaaddr, Gate)
        struct rtentry *rt;
        struct sockaddr *Ifpaddr, *Ifaaddr, *Gate;
{
        struct ifaddr *ifa = 0;
        struct ifnet  *ifp = 0;

        /* new gateway could require new ifaddr, ifp;
           flags may also be different; ifp may be specified
           by ll sockaddr when protocol address is ambiguous */
        if (Ifpaddr && (ifa = ifa_ifwithnet(Ifpaddr)) &&
            (ifp = ifa->ifa_ifp) && (Ifaaddr || Gate))
                ifa = ifaof_ifpforaddr(Ifaaddr ? Ifaaddr : Gate,
                                        ifp);
        else if (Ifpaddr && (ifp = if_withname(Ifpaddr)) ) {
                ifa = Gate ? ifaof_ifpforaddr(Gate, ifp) :
                                TAILQ_FIRST(&ifp->if_addrhead);
        }
        else if ((Ifaaddr && (ifa = ifa_ifwithaddr(Ifaaddr))) ||
                 (Gate && (ifa = ifa_ifwithroute(rt->rt_flags,
                                        rt_key(rt), Gate))))
                ifp = ifa->ifa_ifp;
        if (ifa) {
                register struct ifaddr *oifa = rt->rt_ifa;
                if (oifa != ifa) {
                    if (oifa && oifa->ifa_rtrequest)
                        oifa->ifa_rtrequest(RTM_DELETE,
                                                rt, Gate);
                        rtsetifa(rt, ifa);
                    rt->rt_ifp = ifp;
                    rt->rt_rmx.rmx_mtu = ifp->if_mtu;
                    if (rt->rt_ifa && rt->rt_ifa->ifa_rtrequest)
                                rt->rt_ifa->ifa_rtrequest(RTM_ADD, rt, Gate);
                } else
                        goto call_ifareq;
                return;
        }
      call_ifareq:
        /* XXX: to reset gateway to correct value, at RTM_CHANGE */
        if (rt->rt_ifa && rt->rt_ifa->ifa_rtrequest)
                rt->rt_ifa->ifa_rtrequest(RTM_ADD, rt, Gate);
}


#define ROUNDUP(a) \
        ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))


/*
 * Extract the addresses of the passed sockaddrs.
 * Do a little sanity checking so as to avoid bad memory references.
 * This data is derived straight from userland.
 */
static int
rt_xaddrs(cp, cplim, rtinfo)
        register caddr_t cp, cplim;
        register struct rt_addrinfo *rtinfo;
{
        register struct sockaddr *sa;
        register int i;

        bzero(rtinfo->rti_info, sizeof(rtinfo->rti_info));
        for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
                if ((rtinfo->rti_addrs & (1 << i)) == 0)
                        continue;
                sa = (struct sockaddr *)cp;
                /*
                 * It won't fit.
                 */
                if ( (cp + sa->sa_len) > cplim ) {
                        return (EINVAL);
                }

                /*
                 * there are no more.. quit now
                 * If there are more bits, they are in error.
                 * I've seen this. route(1) can evidently generate these. 
                 * This causes kernel to core dump.
                 * for compatibility, If we see this, point to a safe address.
                 */
                if (sa->sa_len == 0) {
                        rtinfo->rti_info[i] = &sa_zero;
                        return (0); /* should be EINVAL but for compat */
                }

                /* accept it */
                rtinfo->rti_info[i] = sa;
                ADVANCE(cp, sa);
        }
        return (0);
}

static struct mbuf *
rt_msg1(type, rtinfo)
        int type;
        register struct rt_addrinfo *rtinfo;
{
        register struct rt_msghdr *rtm;
        register struct mbuf *m;
        register int i;
        register struct sockaddr *sa;
        int len, dlen;

        switch (type) {

        case RTM_DELADDR:
        case RTM_NEWADDR:
                len = sizeof(struct ifa_msghdr);
                break;

        case RTM_DELMADDR:
        case RTM_NEWMADDR:
                len = sizeof(struct ifma_msghdr);
                break;

        case RTM_IFINFO:
                len = sizeof(struct if_msghdr);
                break;

        default:
                len = sizeof(struct rt_msghdr);
        }
        if (len > MCLBYTES)
                panic("rt_msg1");
        m = m_gethdr(M_DONTWAIT, MT_DATA);
        if (m && len > MHLEN) {
                MCLGET(m, M_DONTWAIT);
                if ((m->m_flags & M_EXT) == 0) {
                        m_free(m);
                        m = NULL;
                }
        }
        if (m == 0)
                return (m);
        m->m_pkthdr.len = m->m_len = len;
        m->m_pkthdr.rcvif = 0;
        rtm = mtod(m, struct rt_msghdr *);
        bzero((caddr_t)rtm, len);
        for (i = 0; i < RTAX_MAX; i++) {
                if ((sa = rtinfo->rti_info[i]) == NULL)
                        continue;
                rtinfo->rti_addrs |= (1 << i);
                dlen = ROUNDUP(sa->sa_len);
                m_copyback(m, len, dlen, (caddr_t)sa);
                len += dlen;
        }
        if (m->m_pkthdr.len != len) {
                m_freem(m);
                return (NULL);
        }
        rtm->rtm_msglen = len;
        rtm->rtm_version = RTM_VERSION;
        rtm->rtm_type = type;
        return (m);
}

static int
rt_msg2(type, rtinfo, cp, w)
        int type;
        register struct rt_addrinfo *rtinfo;
        caddr_t cp;
        struct walkarg *w;
{
        register int i;
        int len, dlen, second_time = 0;
        caddr_t cp0;

        rtinfo->rti_addrs = 0;
again:
        switch (type) {

        case RTM_DELADDR:
        case RTM_NEWADDR:
                len = sizeof(struct ifa_msghdr);
                break;

        case RTM_IFINFO:
                len = sizeof(struct if_msghdr);
                break;

        default:
                len = sizeof(struct rt_msghdr);
        }
        cp0 = cp;
        if (cp0)
                cp += len;
        for (i = 0; i < RTAX_MAX; i++) {
                register struct sockaddr *sa;

                if ((sa = rtinfo->rti_info[i]) == 0)
                        continue;
                rtinfo->rti_addrs |= (1 << i);
                dlen = ROUNDUP(sa->sa_len);
                if (cp) {
                        bcopy((caddr_t)sa, cp, (unsigned)dlen);
                        cp += dlen;
                }
                len += dlen;
        }
        if (cp == 0 && w != NULL && !second_time) {
                register struct walkarg *rw = w;

                if (rw->w_req) {
                        if (rw->w_tmemsize < len) {
                                if (rw->w_tmem)
                                        FREE(rw->w_tmem, M_RTABLE);
                                rw->w_tmem = (caddr_t)
                                        _MALLOC(len, M_RTABLE, M_WAITOK); /*###LD0412 was NOWAIT */
                                if (rw->w_tmem)
                                        rw->w_tmemsize = len;
                        }
                        if (rw->w_tmem) {
                                cp = rw->w_tmem;
                                second_time = 1;
                                goto again;
                        }
                }
        }
        if (cp) {
                register struct rt_msghdr *rtm = (struct rt_msghdr *)cp0;

                rtm->rtm_version = RTM_VERSION;
                rtm->rtm_type = type;
                rtm->rtm_msglen = len;
        }
        return (len);
}

/*
 * This routine is called to generate a message from the routing
 * socket indicating that a redirect has occured, a routing lookup
 * has failed, or that a protocol has detected timeouts to a particular
 * destination.
 */
void
rt_missmsg(type, rtinfo, flags, error)
        int type, flags, error;
        register struct rt_addrinfo *rtinfo;
{
        register struct rt_msghdr *rtm;
        register struct mbuf *m;
        struct sockaddr *sa = rtinfo->rti_info[RTAX_DST];

        if (route_cb.any_count == 0)
                return;
        m = rt_msg1(type, rtinfo);
        if (m == 0)
                return;
        rtm = mtod(m, struct rt_msghdr *);
        rtm->rtm_flags = RTF_DONE | flags;
        rtm->rtm_errno = error;
        rtm->rtm_addrs = rtinfo->rti_addrs;
        route_proto.sp_protocol = sa ? sa->sa_family : 0;
        raw_input(m, &route_proto, &route_src, &route_dst);
}

/*
 * This routine is called to generate a message from the routing
 * socket indicating that the status of a network interface has changed.
 */
void
rt_ifmsg(ifp)
        register struct ifnet *ifp;
{
        register struct if_msghdr *ifm;
        struct mbuf *m;
        struct rt_addrinfo info;

        if (route_cb.any_count == 0)
                return;
        bzero((caddr_t)&info, sizeof(info));
        m = rt_msg1(RTM_IFINFO, &info);
        if (m == 0)
                return;
        ifm = mtod(m, struct if_msghdr *);
        ifm->ifm_index = ifp->if_index;
        ifm->ifm_flags = (u_short)ifp->if_flags;
        ifm->ifm_data = ifp->if_data;
        ifm->ifm_addrs = 0;
        route_proto.sp_protocol = 0;
        raw_input(m, &route_proto, &route_src, &route_dst);
}

/*
 * This is called to generate messages from the routing socket
 * indicating a network interface has had addresses associated with it.
 * if we ever reverse the logic and replace messages TO the routing
 * socket indicate a request to configure interfaces, then it will
 * be unnecessary as the routing socket will automatically generate
 * copies of it.
 */
void
rt_newaddrmsg(cmd, ifa, error, rt)
        int cmd, error;
        register struct ifaddr *ifa;
        register struct rtentry *rt;
{
        struct rt_addrinfo info;
        struct sockaddr *sa = 0;
        int pass;
        struct mbuf *m = 0;
        struct ifnet *ifp = ifa->ifa_ifp;

        if (route_cb.any_count == 0)
                return;
        for (pass = 1; pass < 3; pass++) {
                bzero((caddr_t)&info, sizeof(info));
                if ((cmd == RTM_ADD && pass == 1) ||
                    (cmd == RTM_DELETE && pass == 2)) {
                        register struct ifa_msghdr *ifam;
                        int ncmd = cmd == RTM_ADD ? RTM_NEWADDR : RTM_DELADDR;

                        ifaaddr = sa = ifa->ifa_addr;
                        ifpaddr = ifp->if_addrhead.tqh_first->ifa_addr;
                        netmask = ifa->ifa_netmask;
                        brdaddr = ifa->ifa_dstaddr;
                        if ((m = rt_msg1(ncmd, &info)) == NULL)
                                continue;
                        ifam = mtod(m, struct ifa_msghdr *);
                        ifam->ifam_index = ifp->if_index;
                        ifam->ifam_metric = ifa->ifa_metric;
                        ifam->ifam_flags = ifa->ifa_flags;
                        ifam->ifam_addrs = info.rti_addrs;
                }
                if ((cmd == RTM_ADD && pass == 2) ||
                    (cmd == RTM_DELETE && pass == 1)) {
                        register struct rt_msghdr *rtm;

                        if (rt == 0)
                                continue;
                        netmask = rt_mask(rt);
                        dst = sa = rt_key(rt);
                        gate = rt->rt_gateway;
                        if ((m = rt_msg1(cmd, &info)) == NULL)
                                continue;
                        rtm = mtod(m, struct rt_msghdr *);
                        rtm->rtm_index = ifp->if_index;
                        rtm->rtm_flags |= rt->rt_flags;
                        rtm->rtm_errno = error;
                        rtm->rtm_addrs = info.rti_addrs;
                }
                route_proto.sp_protocol = sa ? sa->sa_family : 0;
                raw_input(m, &route_proto, &route_src, &route_dst);
        }
}

/*
 * This is the analogue to the rt_newaddrmsg which performs the same
 * function but for multicast group memberhips.  This is easier since
 * there is no route state to worry about.
 */
void
rt_newmaddrmsg(cmd, ifma)
        int cmd;
        struct ifmultiaddr *ifma;
{
        struct rt_addrinfo info;
        struct mbuf *m = 0;
        struct ifnet *ifp = ifma->ifma_ifp;
        struct ifma_msghdr *ifmam;

        if (route_cb.any_count == 0)
                return;

        bzero((caddr_t)&info, sizeof(info));
        ifaaddr = ifma->ifma_addr;
        if (ifp && ifp->if_addrhead.tqh_first)
                ifpaddr = ifp->if_addrhead.tqh_first->ifa_addr;
        else
                ifpaddr = NULL;
        /*
         * If a link-layer address is present, present it as a ``gateway''
         * (similarly to how ARP entries, e.g., are presented).
         */
        gate = ifma->ifma_lladdr;
        if ((m = rt_msg1(cmd, &info)) == NULL)
                return;
        ifmam = mtod(m, struct ifma_msghdr *);
        ifmam->ifmam_index = ifp->if_index;
        ifmam->ifmam_addrs = info.rti_addrs;
        route_proto.sp_protocol = ifma->ifma_addr->sa_family;
        raw_input(m, &route_proto, &route_src, &route_dst);
}

/*
 * This is used in dumping the kernel table via sysctl().
 */
int
sysctl_dumpentry(rn, vw)
        struct radix_node *rn;
        void *vw;
{
        register struct walkarg *w = vw;
        register struct rtentry *rt = (struct rtentry *)rn;
        int error = 0, size;
        struct rt_addrinfo info;

        if (w->w_op == NET_RT_FLAGS && !(rt->rt_flags & w->w_arg))
                return 0;
        bzero((caddr_t)&info, sizeof(info));
        dst = rt_key(rt);
        gate = rt->rt_gateway;
        netmask = rt_mask(rt);
        genmask = rt->rt_genmask;
        size = rt_msg2(RTM_GET, &info, 0, w);
        if (w->w_req && w->w_tmem) {
                register struct rt_msghdr *rtm = (struct rt_msghdr *)w->w_tmem;

                rtm->rtm_flags = rt->rt_flags;
                rtm->rtm_use = rt->rt_use;
                rtm->rtm_rmx = rt->rt_rmx;
                rtm->rtm_index = rt->rt_ifp->if_index;
                rtm->rtm_errno = rtm->rtm_pid = rtm->rtm_seq = 0;
                rtm->rtm_addrs = info.rti_addrs;
                error = SYSCTL_OUT(w->w_req, (caddr_t)rtm, size);
                return (error);
        }
        return (error);
}

int
sysctl_iflist(af, w)
        int     af;
        register struct walkarg *w;
{
        register struct ifnet *ifp;
        register struct ifaddr *ifa;
        struct  rt_addrinfo info;
        int     len, error = 0;

        bzero((caddr_t)&info, sizeof(info));
        for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next) {
                if (w->w_arg && w->w_arg != ifp->if_index)
                        continue;
                ifa = ifp->if_addrhead.tqh_first;
                ifpaddr = ifa->ifa_addr;
                len = rt_msg2(RTM_IFINFO, &info, (caddr_t)0, w);
                ifpaddr = 0;
                if (w->w_req && w->w_tmem) {
                        register struct if_msghdr *ifm;

                        ifm = (struct if_msghdr *)w->w_tmem;
                        ifm->ifm_index = ifp->if_index;
                        ifm->ifm_flags = (u_short)ifp->if_flags;
                        ifm->ifm_data = ifp->if_data;
                        ifm->ifm_addrs = info.rti_addrs;
                        error = SYSCTL_OUT(w->w_req,(caddr_t)ifm, len);
                        if (error)
                                return (error);
                }
                while ((ifa = ifa->ifa_link.tqe_next) != 0) {
                        if (af && af != ifa->ifa_addr->sa_family)
                                continue;
#ifndef __APPLE__
                        if (curproc->p_prison && prison_if(curproc, ifa->ifa_addr))
                                continue;
#endif
                        ifaaddr = ifa->ifa_addr;
                        netmask = ifa->ifa_netmask;
                        brdaddr = ifa->ifa_dstaddr;
                        len = rt_msg2(RTM_NEWADDR, &info, 0, w);
                        if (w->w_req && w->w_tmem) {
                                register struct ifa_msghdr *ifam;

                                ifam = (struct ifa_msghdr *)w->w_tmem;
                                ifam->ifam_index = ifa->ifa_ifp->if_index;
                                ifam->ifam_flags = ifa->ifa_flags;
                                ifam->ifam_metric = ifa->ifa_metric;
                                ifam->ifam_addrs = info.rti_addrs;
                                error = SYSCTL_OUT(w->w_req, w->w_tmem, len);
                                if (error)
                                        return (error);
                        }
                }
                ifaaddr = netmask = brdaddr = 0;
        }
        return (0);
}

static int
sysctl_rtsock SYSCTL_HANDLER_ARGS
{
        int     *name = (int *)arg1;
        u_int   namelen = arg2;
        register struct radix_node_head *rnh;
        int     i, s, error = EINVAL;
        u_char  af;
        struct  walkarg w;

        name ++;
        namelen--;
        if (req->newptr)
                return (EPERM);
        if (namelen != 3)
                return (EINVAL);
        af = name[0];
        Bzero(&w, sizeof(w));
        w.w_op = name[1];
        w.w_arg = name[2];
        w.w_req = req;

        s = splnet();
        switch (w.w_op) {

        case NET_RT_DUMP:
        case NET_RT_FLAGS:
                for (i = 1; i <= AF_MAX; i++)
                        if ((rnh = rt_tables[i]) && (af == 0 || af == i) &&
                            (error = rnh->rnh_walktree(rnh,
                                                        sysctl_dumpentry, &w)))
                                break;
                break;

        case NET_RT_IFLIST:
                error = sysctl_iflist(af, &w);
        }
        splx(s);
        if (w.w_tmem)
                FREE(w.w_tmem, M_RTABLE);
        return (error);
}

SYSCTL_NODE(_net, PF_ROUTE, routetable, CTLFLAG_RD, sysctl_rtsock, "");

/*
 * Definitions of protocols supported in the ROUTE domain.
 */

struct domain routedomain;              /* or at least forward */

static struct protosw routesw[] = {
{ SOCK_RAW,     &routedomain,   0,              PR_ATOMIC|PR_ADDR,
  0,            route_output,   raw_ctlinput,   0,
  0,
  raw_init,     0,              0,              0,
  0, &route_usrreqs, 0, 0
}
};

struct domain routedomain =
    { PF_ROUTE, "route", route_init, 0, 0,
      routesw};

DOMAIN_SET(route);