syscons,vt: improve phrasing in kern.vty man page description

[freebsd-src.git] / sys / net / route.c

/*-
 * Copyright (c) 1980, 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.
 * 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.
 *
 *      @(#)route.c     8.3.1.1 (Berkeley) 2/23/95
 * $FreeBSD$
 */
/************************************************************************
 * Note: In this file a 'fib' is a "forwarding information base"        *
 * Which is the new name for an in kernel routing (next hop) table.     *
 ***********************************************************************/

#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_route.h"
#include "opt_sctp.h"
#include "opt_mrouting.h"
#include "opt_mpath.h"

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

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/route_var.h>
#include <net/vnet.h>
#include <net/flowtable.h>

#ifdef RADIX_MPATH
#include <net/radix_mpath.h>
#endif

#include <netinet/in.h>
#include <netinet/ip_mroute.h>

#include <vm/uma.h>

#define RT_MAXFIBS      UINT16_MAX

/* Kernel config default option. */
#ifdef ROUTETABLES
#if ROUTETABLES <= 0
#error "ROUTETABLES defined too low"
#endif
#if ROUTETABLES > RT_MAXFIBS
#error "ROUTETABLES defined too big"
#endif
#define RT_NUMFIBS      ROUTETABLES
#endif /* ROUTETABLES */
/* Initialize to default if not otherwise set. */
#ifndef RT_NUMFIBS
#define RT_NUMFIBS      1
#endif

#if defined(INET) || defined(INET6)
#ifdef SCTP
extern void sctp_addr_change(struct ifaddr *ifa, int cmd);
#endif /* SCTP */
#endif


/* This is read-only.. */
u_int rt_numfibs = RT_NUMFIBS;
SYSCTL_UINT(_net, OID_AUTO, fibs, CTLFLAG_RDTUN, &rt_numfibs, 0, "");

/*
 * By default add routes to all fibs for new interfaces.
 * Once this is set to 0 then only allocate routes on interface
 * changes for the FIB of the caller when adding a new set of addresses
 * to an interface.  XXX this is a shotgun aproach to a problem that needs
 * a more fine grained solution.. that will come.
 * XXX also has the problems getting the FIB from curthread which will not
 * always work given the fib can be overridden and prefixes can be added
 * from the network stack context.
 */
VNET_DEFINE(u_int, rt_add_addr_allfibs) = 1;
SYSCTL_UINT(_net, OID_AUTO, add_addr_allfibs, CTLFLAG_RWTUN | CTLFLAG_VNET,
    &VNET_NAME(rt_add_addr_allfibs), 0, "");

VNET_DEFINE(struct rtstat, rtstat);
#define V_rtstat        VNET(rtstat)

VNET_DEFINE(struct rib_head *, rt_tables);
#define V_rt_tables     VNET(rt_tables)

VNET_DEFINE(int, rttrash);              /* routes not in table but not freed */
#define V_rttrash       VNET(rttrash)


/*
 * Convert a 'struct radix_node *' to a 'struct rtentry *'.
 * The operation can be done safely (in this code) because a
 * 'struct rtentry' starts with two 'struct radix_node''s, the first
 * one representing leaf nodes in the routing tree, which is
 * what the code in radix.c passes us as a 'struct radix_node'.
 *
 * But because there are a lot of assumptions in this conversion,
 * do not cast explicitly, but always use the macro below.
 */
#define RNTORT(p)       ((struct rtentry *)(p))

static VNET_DEFINE(uma_zone_t, rtzone);         /* Routing table UMA zone. */
#define V_rtzone        VNET(rtzone)

static int rtrequest1_fib_change(struct rib_head *, struct rt_addrinfo *,
    struct rtentry **, u_int);
static void rt_setmetrics(const struct rt_addrinfo *, struct rtentry *);
static int rt_ifdelroute(const struct rtentry *rt, void *arg);
static struct rtentry *rt_unlinkrte(struct rib_head *rnh,
    struct rt_addrinfo *info, int *perror);
static void rt_notifydelete(struct rtentry *rt, struct rt_addrinfo *info);
#ifdef RADIX_MPATH
static struct radix_node *rt_mpath_unlink(struct rib_head *rnh,
    struct rt_addrinfo *info, struct rtentry *rto, int *perror);
#endif
static int rt_exportinfo(struct rtentry *rt, struct rt_addrinfo *info,
    int flags);

struct if_mtuinfo
{
        struct ifnet    *ifp;
        int             mtu;
};

static int      if_updatemtu_cb(struct radix_node *, void *);

/*
 * handler for net.my_fibnum
 */
static int
sysctl_my_fibnum(SYSCTL_HANDLER_ARGS)
{
        int fibnum;
        int error;
 
        fibnum = curthread->td_proc->p_fibnum;
        error = sysctl_handle_int(oidp, &fibnum, 0, req);
        return (error);
}

SYSCTL_PROC(_net, OID_AUTO, my_fibnum, CTLTYPE_INT|CTLFLAG_RD,
            NULL, 0, &sysctl_my_fibnum, "I", "default FIB of caller");

static __inline struct rib_head **
rt_tables_get_rnh_ptr(int table, int fam)
{
        struct rib_head **rnh;

        KASSERT(table >= 0 && table < rt_numfibs, ("%s: table out of bounds.",
            __func__));
        KASSERT(fam >= 0 && fam < (AF_MAX+1), ("%s: fam out of bounds.",
            __func__));

        /* rnh is [fib=0][af=0]. */
        rnh = (struct rib_head **)V_rt_tables;
        /* Get the offset to the requested table and fam. */
        rnh += table * (AF_MAX+1) + fam;

        return (rnh);
}

struct rib_head *
rt_tables_get_rnh(int table, int fam)
{

        return (*rt_tables_get_rnh_ptr(table, fam));
}

u_int
rt_tables_get_gen(int table, int fam)
{
        struct rib_head *rnh;

        rnh = *rt_tables_get_rnh_ptr(table, fam);
        KASSERT(rnh != NULL, ("%s: NULL rib_head pointer table %d fam %d",
            __func__, table, fam));
        return (rnh->rnh_gen);
}


/*
 * route initialization must occur before ip6_init2(), which happenas at
 * SI_ORDER_MIDDLE.
 */
static void
route_init(void)
{

        /* whack the tunable ints into  line. */
        if (rt_numfibs > RT_MAXFIBS)
                rt_numfibs = RT_MAXFIBS;
        if (rt_numfibs == 0)
                rt_numfibs = 1;
}
SYSINIT(route_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, route_init, 0);

static int
rtentry_zinit(void *mem, int size, int how)
{
        struct rtentry *rt = mem;

        rt->rt_pksent = counter_u64_alloc(how);
        if (rt->rt_pksent == NULL)
                return (ENOMEM);

        RT_LOCK_INIT(rt);

        return (0);
}

static void
rtentry_zfini(void *mem, int size)
{
        struct rtentry *rt = mem;

        RT_LOCK_DESTROY(rt);
        counter_u64_free(rt->rt_pksent);
}

static int
rtentry_ctor(void *mem, int size, void *arg, int how)
{
        struct rtentry *rt = mem;

        bzero(rt, offsetof(struct rtentry, rt_endzero));
        counter_u64_zero(rt->rt_pksent);
        rt->rt_chain = NULL;

        return (0);
}

static void
rtentry_dtor(void *mem, int size, void *arg)
{
        struct rtentry *rt = mem;

        RT_UNLOCK_COND(rt);
}

static void
vnet_route_init(const void *unused __unused)
{
        struct domain *dom;
        struct rib_head **rnh;
        int table;
        int fam;

        V_rt_tables = malloc(rt_numfibs * (AF_MAX+1) *
            sizeof(struct rib_head *), M_RTABLE, M_WAITOK|M_ZERO);

        V_rtzone = uma_zcreate("rtentry", sizeof(struct rtentry),
            rtentry_ctor, rtentry_dtor,
            rtentry_zinit, rtentry_zfini, UMA_ALIGN_PTR, 0);
        for (dom = domains; dom; dom = dom->dom_next) {
                if (dom->dom_rtattach == NULL)
                        continue;

                for  (table = 0; table < rt_numfibs; table++) {
                        fam = dom->dom_family;
                        if (table != 0 && fam != AF_INET6 && fam != AF_INET)
                                break;

                        rnh = rt_tables_get_rnh_ptr(table, fam);
                        if (rnh == NULL)
                                panic("%s: rnh NULL", __func__);
                        dom->dom_rtattach((void **)rnh, 0);
                }
        }
}
VNET_SYSINIT(vnet_route_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH,
    vnet_route_init, 0);

#ifdef VIMAGE
static void
vnet_route_uninit(const void *unused __unused)
{
        int table;
        int fam;
        struct domain *dom;
        struct rib_head **rnh;

        for (dom = domains; dom; dom = dom->dom_next) {
                if (dom->dom_rtdetach == NULL)
                        continue;

                for (table = 0; table < rt_numfibs; table++) {
                        fam = dom->dom_family;

                        if (table != 0 && fam != AF_INET6 && fam != AF_INET)
                                break;

                        rnh = rt_tables_get_rnh_ptr(table, fam);
                        if (rnh == NULL)
                                panic("%s: rnh NULL", __func__);
                        dom->dom_rtdetach((void **)rnh, 0);
                }
        }

        free(V_rt_tables, M_RTABLE);
        uma_zdestroy(V_rtzone);
}
VNET_SYSUNINIT(vnet_route_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST,
    vnet_route_uninit, 0);
#endif

struct rib_head *
rt_table_init(int offset)
{
        struct rib_head *rh;

        rh = malloc(sizeof(struct rib_head), M_RTABLE, M_WAITOK | M_ZERO);

        /* TODO: These details should be hidded inside radix.c */
        /* Init masks tree */
        rn_inithead_internal(&rh->head, rh->rnh_nodes, offset);
        rn_inithead_internal(&rh->rmhead.head, rh->rmhead.mask_nodes, 0);
        rh->head.rnh_masks = &rh->rmhead;

        /* Init locks */
        rw_init(&rh->rib_lock, "rib head lock");

        /* Finally, set base callbacks */
        rh->rnh_addaddr = rn_addroute;
        rh->rnh_deladdr = rn_delete;
        rh->rnh_matchaddr = rn_match;
        rh->rnh_lookup = rn_lookup;
        rh->rnh_walktree = rn_walktree;
        rh->rnh_walktree_from = rn_walktree_from;

        return (rh);
}

static int
rt_freeentry(struct radix_node *rn, void *arg)
{
        struct radix_head * const rnh = arg;
        struct radix_node *x;

        x = (struct radix_node *)rn_delete(rn + 2, NULL, rnh);
        if (x != NULL)
                R_Free(x);
        return (0);
}

void
rt_table_destroy(struct rib_head *rh)
{

        rn_walktree(&rh->rmhead.head, rt_freeentry, &rh->rmhead.head);

        /* Assume table is already empty */
        rw_destroy(&rh->rib_lock);
        free(rh, M_RTABLE);
}


#ifndef _SYS_SYSPROTO_H_
struct setfib_args {
        int     fibnum;
};
#endif
int
sys_setfib(struct thread *td, struct setfib_args *uap)
{
        if (uap->fibnum < 0 || uap->fibnum >= rt_numfibs)
                return EINVAL;
        td->td_proc->p_fibnum = uap->fibnum;
        return (0);
}

/*
 * Packet routing routines.
 */
void
rtalloc_ign_fib(struct route *ro, u_long ignore, u_int fibnum)
{
        struct rtentry *rt;

        if ((rt = ro->ro_rt) != NULL) {
                if (rt->rt_ifp != NULL && rt->rt_flags & RTF_UP)
                        return;
                RTFREE(rt);
                ro->ro_rt = NULL;
        }
        ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, ignore, fibnum);
        if (ro->ro_rt)
                RT_UNLOCK(ro->ro_rt);
}

/*
 * Look up the route that matches the address given
 * Or, at least try.. Create a cloned route if needed.
 *
 * The returned route, if any, is locked.
 */
struct rtentry *
rtalloc1(struct sockaddr *dst, int report, u_long ignflags)
{

        return (rtalloc1_fib(dst, report, ignflags, RT_DEFAULT_FIB));
}

struct rtentry *
rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags,
                    u_int fibnum)
{
        struct rib_head *rh;
        struct radix_node *rn;
        struct rtentry *newrt;
        struct rt_addrinfo info;
        int err = 0, msgtype = RTM_MISS;

        KASSERT((fibnum < rt_numfibs), ("rtalloc1_fib: bad fibnum"));
        rh = rt_tables_get_rnh(fibnum, dst->sa_family);
        newrt = NULL;
        if (rh == NULL)
                goto miss;

        /*
         * Look up the address in the table for that Address Family
         */
        RIB_RLOCK(rh);
        rn = rh->rnh_matchaddr(dst, &rh->head);
        if (rn && ((rn->rn_flags & RNF_ROOT) == 0)) {
                newrt = RNTORT(rn);
                RT_LOCK(newrt);
                RT_ADDREF(newrt);
                RIB_RUNLOCK(rh);
                return (newrt);

        } else
                RIB_RUNLOCK(rh);
        
        /*
         * Either we hit the root or couldn't find any match,
         * Which basically means
         * "caint get there frm here"
         */
miss:
        V_rtstat.rts_unreach++;

        if (report) {
                /*
                 * If required, report the failure to the supervising
                 * Authorities.
                 * For a delete, this is not an error. (report == 0)
                 */
                bzero(&info, sizeof(info));
                info.rti_info[RTAX_DST] = dst;
                rt_missmsg_fib(msgtype, &info, 0, err, fibnum);
        }
        return (newrt);
}

/*
 * Remove a reference count from an rtentry.
 * If the count gets low enough, take it out of the routing table
 */
void
rtfree(struct rtentry *rt)
{
        struct rib_head *rnh;

        KASSERT(rt != NULL,("%s: NULL rt", __func__));
        rnh = rt_tables_get_rnh(rt->rt_fibnum, rt_key(rt)->sa_family);
        KASSERT(rnh != NULL,("%s: NULL rnh", __func__));

        RT_LOCK_ASSERT(rt);

        /*
         * The callers should use RTFREE_LOCKED() or RTFREE(), so
         * we should come here exactly with the last reference.
         */
        RT_REMREF(rt);
        if (rt->rt_refcnt > 0) {
                log(LOG_DEBUG, "%s: %p has %d refs\n", __func__, rt, rt->rt_refcnt);
                goto done;
        }

        /*
         * On last reference give the "close method" a chance
         * to cleanup private state.  This also permits (for
         * IPv4 and IPv6) a chance to decide if the routing table
         * entry should be purged immediately or at a later time.
         * When an immediate purge is to happen the close routine
         * typically calls rtexpunge which clears the RTF_UP flag
         * on the entry so that the code below reclaims the storage.
         */
        if (rt->rt_refcnt == 0 && rnh->rnh_close)
                rnh->rnh_close((struct radix_node *)rt, &rnh->head);

        /*
         * If we are no longer "up" (and ref == 0)
         * then we can free the resources associated
         * with the route.
         */
        if ((rt->rt_flags & RTF_UP) == 0) {
                if (rt->rt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT))
                        panic("rtfree 2");
                /*
                 * the rtentry must have been removed from the routing table
                 * so it is represented in rttrash.. remove that now.
                 */
                V_rttrash--;
#ifdef  DIAGNOSTIC
                if (rt->rt_refcnt < 0) {
                        printf("rtfree: %p not freed (neg refs)\n", rt);
                        goto done;
                }
#endif
                /*
                 * release references on items we hold them on..
                 * e.g other routes and ifaddrs.
                 */
                if (rt->rt_ifa)
                        ifa_free(rt->rt_ifa);
                /*
                 * The key is separatly alloc'd so free it (see rt_setgate()).
                 * This also frees the gateway, as they are always malloc'd
                 * together.
                 */
                R_Free(rt_key(rt));

                /*
                 * and the rtentry itself of course
                 */
                uma_zfree(V_rtzone, rt);
                return;
        }
done:
        RT_UNLOCK(rt);
}


/*
 * Force a routing table entry to the specified
 * destination to go through the given gateway.
 * Normally called as a result of a routing redirect
 * message from the network layer.
 */
void
rtredirect_fib(struct sockaddr *dst,
        struct sockaddr *gateway,
        struct sockaddr *netmask,
        int flags,
        struct sockaddr *src,
        u_int fibnum)
{
        struct rtentry *rt;
        int error = 0;
        short *stat = NULL;
        struct rt_addrinfo info;
        struct ifaddr *ifa;
        struct rib_head *rnh;

        ifa = NULL;
        rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
        if (rnh == NULL) {
                error = EAFNOSUPPORT;
                goto out;
        }

        /* verify the gateway is directly reachable */
        if ((ifa = ifa_ifwithnet(gateway, 0, fibnum)) == NULL) {
                error = ENETUNREACH;
                goto out;
        }
        rt = rtalloc1_fib(dst, 0, 0UL, fibnum); /* NB: rt is locked */
        /*
         * If the redirect isn't from our current router for this dst,
         * it's either old or wrong.  If it redirects us to ourselves,
         * we have a routing loop, perhaps as a result of an interface
         * going down recently.
         */
        if (!(flags & RTF_DONE) && rt) {
                if (!sa_equal(src, rt->rt_gateway)) {
                        error = EINVAL;
                        goto done;
                }
                if (rt->rt_ifa != ifa && ifa->ifa_addr->sa_family != AF_LINK) {
                        error = EINVAL;
                        goto done;
                }
        }
        if ((flags & RTF_GATEWAY) && ifa_ifwithaddr_check(gateway)) {
                error = EHOSTUNREACH;
                goto done;
        }
        /*
         * Create a new entry if we just got back a wildcard entry
         * or the lookup failed.  This is necessary for hosts
         * which use routing redirects generated by smart gateways
         * to dynamically build the routing tables.
         */
        if (rt == NULL || (rt_mask(rt) && rt_mask(rt)->sa_len < 2))
                goto create;
        /*
         * Don't listen to the redirect if it's
         * for a route to an interface.
         */
        if (rt->rt_flags & RTF_GATEWAY) {
                if (((rt->rt_flags & RTF_HOST) == 0) && (flags & RTF_HOST)) {
                        /*
                         * Changing from route to net => route to host.
                         * Create new route, rather than smashing route to net.
                         */
                create:
                        if (rt != NULL)
                                RTFREE_LOCKED(rt);
                
                        flags |= RTF_DYNAMIC;
                        bzero((caddr_t)&info, sizeof(info));
                        info.rti_info[RTAX_DST] = dst;
                        info.rti_info[RTAX_GATEWAY] = gateway;
                        info.rti_info[RTAX_NETMASK] = netmask;
                        info.rti_ifa = ifa;
                        info.rti_flags = flags;
                        error = rtrequest1_fib(RTM_ADD, &info, &rt, fibnum);
                        if (rt != NULL) {
                                RT_LOCK(rt);
                                flags = rt->rt_flags;
                        }
                        
                        stat = &V_rtstat.rts_dynamic;
                } else {

                        /*
                         * Smash the current notion of the gateway to
                         * this destination.  Should check about netmask!!!
                         */
                        if ((flags & RTF_GATEWAY) == 0)
                                rt->rt_flags &= ~RTF_GATEWAY;
                        rt->rt_flags |= RTF_MODIFIED;
                        flags |= RTF_MODIFIED;
                        stat = &V_rtstat.rts_newgateway;
                        /*
                         * add the key and gateway (in one malloc'd chunk).
                         */
                        RT_UNLOCK(rt);
                        RIB_WLOCK(rnh);
                        RT_LOCK(rt);
                        rt_setgate(rt, rt_key(rt), gateway);
                        RIB_WUNLOCK(rnh);
                }
        } else
                error = EHOSTUNREACH;
done:
        if (rt)
                RTFREE_LOCKED(rt);
out:
        if (error)
                V_rtstat.rts_badredirect++;
        else if (stat != NULL)
                (*stat)++;
        bzero((caddr_t)&info, sizeof(info));
        info.rti_info[RTAX_DST] = dst;
        info.rti_info[RTAX_GATEWAY] = gateway;
        info.rti_info[RTAX_NETMASK] = netmask;
        info.rti_info[RTAX_AUTHOR] = src;
        rt_missmsg_fib(RTM_REDIRECT, &info, flags, error, fibnum);
        if (ifa != NULL)
                ifa_free(ifa);
}

/*
 * Routing table ioctl interface.
 */
int
rtioctl_fib(u_long req, caddr_t data, u_int fibnum)
{

        /*
         * If more ioctl commands are added here, make sure the proper
         * super-user checks are being performed because it is possible for
         * prison-root to make it this far if raw sockets have been enabled
         * in jails.
         */
#ifdef INET
        /* Multicast goop, grrr... */
        return mrt_ioctl ? mrt_ioctl(req, data, fibnum) : EOPNOTSUPP;
#else /* INET */
        return ENXIO;
#endif /* INET */
}

struct ifaddr *
ifa_ifwithroute(int flags, const struct sockaddr *dst, struct sockaddr *gateway,
                                u_int fibnum)
{
        struct ifaddr *ifa;
        int not_found = 0;

        if ((flags & RTF_GATEWAY) == 0) {
                /*
                 * If we are adding a route to an interface,
                 * and the interface is a pt to pt link
                 * we should search for the destination
                 * as our clue to the interface.  Otherwise
                 * we can use the local address.
                 */
                ifa = NULL;
                if (flags & RTF_HOST)
                        ifa = ifa_ifwithdstaddr(dst, fibnum);
                if (ifa == NULL)
                        ifa = ifa_ifwithaddr(gateway);
        } else {
                /*
                 * If we are adding a route to a remote net
                 * or host, the gateway may still be on the
                 * other end of a pt to pt link.
                 */
                ifa = ifa_ifwithdstaddr(gateway, fibnum);
        }
        if (ifa == NULL)
                ifa = ifa_ifwithnet(gateway, 0, fibnum);
        if (ifa == NULL) {
                struct rtentry *rt = rtalloc1_fib(gateway, 0, 0, fibnum);
                if (rt == NULL)
                        return (NULL);
                /*
                 * dismiss a gateway that is reachable only
                 * through the default router
                 */
                switch (gateway->sa_family) {
                case AF_INET:
                        if (satosin(rt_key(rt))->sin_addr.s_addr == INADDR_ANY)
                                not_found = 1;
                        break;
                case AF_INET6:
                        if (IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(rt))->sin6_addr))
                                not_found = 1;
                        break;
                default:
                        break;
                }
                if (!not_found && rt->rt_ifa != NULL) {
                        ifa = rt->rt_ifa;
                        ifa_ref(ifa);
                }
                RT_REMREF(rt);
                RT_UNLOCK(rt);
                if (not_found || ifa == NULL)
                        return (NULL);
        }
        if (ifa->ifa_addr->sa_family != dst->sa_family) {
                struct ifaddr *oifa = ifa;
                ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
                if (ifa == NULL)
                        ifa = oifa;
                else
                        ifa_free(oifa);
        }
        return (ifa);
}

/*
 * Do appropriate manipulations of a routing tree given
 * all the bits of info needed
 */
int
rtrequest_fib(int req,
        struct sockaddr *dst,
        struct sockaddr *gateway,
        struct sockaddr *netmask,
        int flags,
        struct rtentry **ret_nrt,
        u_int fibnum)
{
        struct rt_addrinfo info;

        if (dst->sa_len == 0)
                return(EINVAL);

        bzero((caddr_t)&info, sizeof(info));
        info.rti_flags = flags;
        info.rti_info[RTAX_DST] = dst;
        info.rti_info[RTAX_GATEWAY] = gateway;
        info.rti_info[RTAX_NETMASK] = netmask;
        return rtrequest1_fib(req, &info, ret_nrt, fibnum);
}


/*
 * Copy most of @rt data into @info.
 *
 * If @flags contains NHR_COPY, copies dst,netmask and gw to the
 * pointers specified by @info structure. Assume such pointers
 * are zeroed sockaddr-like structures with sa_len field initialized
 * to reflect size of the provided buffer. if no NHR_COPY is specified,
 * point dst,netmask and gw @info fields to appropriate @rt values.
 *
 * if @flags contains NHR_REF, do refcouting on rt_ifp.
 *
 * Returns 0 on success.
 */
int
rt_exportinfo(struct rtentry *rt, struct rt_addrinfo *info, int flags)
{
        struct rt_metrics *rmx;
        struct sockaddr *src, *dst;
        int sa_len;

        if (flags & NHR_COPY) {
                /* Copy destination if dst is non-zero */
                src = rt_key(rt);
                dst = info->rti_info[RTAX_DST];
                sa_len = src->sa_len;
                if (dst != NULL) {
                        if (src->sa_len > dst->sa_len)
                                return (ENOMEM);
                        memcpy(dst, src, src->sa_len);
                        info->rti_addrs |= RTA_DST;
                }

                /* Copy mask if set && dst is non-zero */
                src = rt_mask(rt);
                dst = info->rti_info[RTAX_NETMASK];
                if (src != NULL && dst != NULL) {

                        /*
                         * Radix stores different value in sa_len,
                         * assume rt_mask() to have the same length
                         * as rt_key()
                         */
                        if (sa_len > dst->sa_len)
                                return (ENOMEM);
                        memcpy(dst, src, src->sa_len);
                        info->rti_addrs |= RTA_NETMASK;
                }

                /* Copy gateway is set && dst is non-zero */
                src = rt->rt_gateway;
                dst = info->rti_info[RTAX_GATEWAY];
                if ((rt->rt_flags & RTF_GATEWAY) && src != NULL && dst != NULL){
                        if (src->sa_len > dst->sa_len)
                                return (ENOMEM);
                        memcpy(dst, src, src->sa_len);
                        info->rti_addrs |= RTA_GATEWAY;
                }
        } else {
                info->rti_info[RTAX_DST] = rt_key(rt);
                info->rti_addrs |= RTA_DST;
                if (rt_mask(rt) != NULL) {
                        info->rti_info[RTAX_NETMASK] = rt_mask(rt);
                        info->rti_addrs |= RTA_NETMASK;
                }
                if (rt->rt_flags & RTF_GATEWAY) {
                        info->rti_info[RTAX_GATEWAY] = rt->rt_gateway;
                        info->rti_addrs |= RTA_GATEWAY;
                }
        }

        rmx = info->rti_rmx;
        if (rmx != NULL) {
                info->rti_mflags |= RTV_MTU;
                rmx->rmx_mtu = rt->rt_mtu;
        }

        info->rti_flags = rt->rt_flags;
        info->rti_ifp = rt->rt_ifp;
        info->rti_ifa = rt->rt_ifa;

        if (flags & NHR_REF) {
                /* Do 'traditional' refcouting */
                if_ref(info->rti_ifp);
        }

        return (0);
}

/*
 * Lookups up route entry for @dst in RIB database for fib @fibnum.
 * Exports entry data to @info using rt_exportinfo().
 *
 * if @flags contains NHR_REF, refcouting is performed on rt_ifp.
 *   All references can be released later by calling rib_free_info()
 *
 * Returns 0 on success.
 * Returns ENOENT for lookup failure, ENOMEM for export failure.
 */
int
rib_lookup_info(uint32_t fibnum, const struct sockaddr *dst, uint32_t flags,
    uint32_t flowid, struct rt_addrinfo *info)
{
        struct rib_head *rh;
        struct radix_node *rn;
        struct rtentry *rt;
        int error;

        KASSERT((fibnum < rt_numfibs), ("rib_lookup_rte: bad fibnum"));
        rh = rt_tables_get_rnh(fibnum, dst->sa_family);
        if (rh == NULL)
                return (ENOENT);

        RIB_RLOCK(rh);
        rn = rh->rnh_matchaddr(__DECONST(void *, dst), &rh->head);
        if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
                rt = RNTORT(rn);
                /* Ensure route & ifp is UP */
                if (RT_LINK_IS_UP(rt->rt_ifp)) {
                        flags = (flags & NHR_REF) | NHR_COPY;
                        error = rt_exportinfo(rt, info, flags);
                        RIB_RUNLOCK(rh);

                        return (error);
                }
        }
        RIB_RUNLOCK(rh);

        return (ENOENT);
}

/*
 * Releases all references acquired by rib_lookup_info() when
 * called with NHR_REF flags.
 */
void
rib_free_info(struct rt_addrinfo *info)
{

        if_rele(info->rti_ifp);
}

/*
 * Iterates over all existing fibs in system calling
 *  @setwa_f function prior to traversing each fib.
 *  Calls @wa_f function for each element in current fib.
 * If af is not AF_UNSPEC, iterates over fibs in particular
 * address family.
 */
void
rt_foreach_fib_walk(int af, rt_setwarg_t *setwa_f, rt_walktree_f_t *wa_f,
    void *arg)
{
        struct rib_head *rnh;
        uint32_t fibnum;
        int i;

        for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
                /* Do we want some specific family? */
                if (af != AF_UNSPEC) {
                        rnh = rt_tables_get_rnh(fibnum, af);
                        if (rnh == NULL)
                                continue;
                        if (setwa_f != NULL)
                                setwa_f(rnh, fibnum, af, arg);

                        RIB_WLOCK(rnh);
                        rnh->rnh_walktree(&rnh->head, (walktree_f_t *)wa_f,arg);
                        RIB_WUNLOCK(rnh);
                        continue;
                }

                for (i = 1; i <= AF_MAX; i++) {
                        rnh = rt_tables_get_rnh(fibnum, i);
                        if (rnh == NULL)
                                continue;
                        if (setwa_f != NULL)
                                setwa_f(rnh, fibnum, i, arg);

                        RIB_WLOCK(rnh);
                        rnh->rnh_walktree(&rnh->head, (walktree_f_t *)wa_f,arg);
                        RIB_WUNLOCK(rnh);
                }
        }
}

struct rt_delinfo
{
        struct rt_addrinfo info;
        struct rib_head *rnh;
        struct rtentry *head;
};

/*
 * Conditionally unlinks @rn from radix tree based
 * on info data passed in @arg.
 */
static int
rt_checkdelroute(struct radix_node *rn, void *arg)
{
        struct rt_delinfo *di;
        struct rt_addrinfo *info;
        struct rtentry *rt;
        int error;

        di = (struct rt_delinfo *)arg;
        rt = (struct rtentry *)rn;
        info = &di->info;
        error = 0;

        info->rti_info[RTAX_DST] = rt_key(rt);
        info->rti_info[RTAX_NETMASK] = rt_mask(rt);
        info->rti_info[RTAX_GATEWAY] = rt->rt_gateway;

        rt = rt_unlinkrte(di->rnh, info, &error);
        if (rt == NULL) {
                /* Either not allowed or not matched. Skip entry */
                return (0);
        }

        /* Entry was unlinked. Add to the list and return */
        rt->rt_chain = di->head;
        di->head = rt;

        return (0);
}

/*
 * Iterates over all existing fibs in system.
 * Deletes each element for which @filter_f function returned
 * non-zero value.
 * If @af is not AF_UNSPEC, iterates over fibs in particular
 * address family.
 */
void
rt_foreach_fib_walk_del(int af, rt_filter_f_t *filter_f, void *arg)
{
        struct rib_head *rnh;
        struct rt_delinfo di;
        struct rtentry *rt;
        uint32_t fibnum;
        int i, start, end;

        bzero(&di, sizeof(di));
        di.info.rti_filter = filter_f;
        di.info.rti_filterdata = arg;

        for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
                /* Do we want some specific family? */
                if (af != AF_UNSPEC) {
                        start = af;
                        end = af;
                } else {
                        start = 1;
                        end = AF_MAX;
                }

                for (i = start; i <= end; i++) {
                        rnh = rt_tables_get_rnh(fibnum, i);
                        if (rnh == NULL)
                                continue;
                        di.rnh = rnh;

                        RIB_WLOCK(rnh);
                        rnh->rnh_walktree(&rnh->head, rt_checkdelroute, &di);
                        RIB_WUNLOCK(rnh);

                        if (di.head == NULL)
                                continue;

                        /* We might have something to reclaim */
                        while (di.head != NULL) {
                                rt = di.head;
                                di.head = rt->rt_chain;
                                rt->rt_chain = NULL;

                                /* TODO std rt -> rt_addrinfo export */
                                di.info.rti_info[RTAX_DST] = rt_key(rt);
                                di.info.rti_info[RTAX_NETMASK] = rt_mask(rt);

                                rt_notifydelete(rt, &di.info);
                                RTFREE_LOCKED(rt);
                        }

                }
        }
}

/*
 * Delete Routes for a Network Interface
 *
 * Called for each routing entry via the rnh->rnh_walktree() call above
 * to delete all route entries referencing a detaching network interface.
 *
 * Arguments:
 *      rt      pointer to rtentry
 *      arg     argument passed to rnh->rnh_walktree() - detaching interface
 *
 * Returns:
 *      0       successful
 *      errno   failed - reason indicated
 */
static int
rt_ifdelroute(const struct rtentry *rt, void *arg)
{
        struct ifnet    *ifp = arg;

        if (rt->rt_ifp != ifp)
                return (0);

        /*
         * Protect (sorta) against walktree recursion problems
         * with cloned routes
         */
        if ((rt->rt_flags & RTF_UP) == 0)
                return (0);

        return (1);
}

/*
 * Delete all remaining routes using this interface
 * Unfortuneatly the only way to do this is to slog through
 * the entire routing table looking for routes which point
 * to this interface...oh well...
 */
void
rt_flushifroutes_af(struct ifnet *ifp, int af)
{
        KASSERT((af >= 1 && af <= AF_MAX), ("%s: af %d not >= 1 and <= %d",
            __func__, af, AF_MAX));

        rt_foreach_fib_walk_del(af, rt_ifdelroute, ifp);
}

void
rt_flushifroutes(struct ifnet *ifp)
{

        rt_foreach_fib_walk_del(AF_UNSPEC, rt_ifdelroute, ifp);
}

/*
 * Conditionally unlinks rtentry matching data inside @info from @rnh.
 * Returns unlinked, locked and referenced @rtentry on success,
 * Returns NULL and sets @perror to:
 * ESRCH - if prefix was not found,
 * EADDRINUSE - if trying to delete PINNED route without appropriate flag.
 * ENOENT - if supplied filter function returned 0 (not matched).
 */
static struct rtentry *
rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info, int *perror)
{
        struct sockaddr *dst, *netmask;
        struct rtentry *rt;
        struct radix_node *rn;

        dst = info->rti_info[RTAX_DST];
        netmask = info->rti_info[RTAX_NETMASK];

        rt = (struct rtentry *)rnh->rnh_lookup(dst, netmask, &rnh->head);
        if (rt == NULL) {
                *perror = ESRCH;
                return (NULL);
        }

        if ((info->rti_flags & RTF_PINNED) == 0) {
                /* Check if target route can be deleted */
                if (rt->rt_flags & RTF_PINNED) {
                        *perror = EADDRINUSE;
                        return (NULL);
                }
        }

        if (info->rti_filter != NULL) {
                if (info->rti_filter(rt, info->rti_filterdata) == 0) {
                        /* Not matched */
                        *perror = ENOENT;
                        return (NULL);
                }

                /*
                 * Filter function requested rte deletion.
                 * Ease the caller work by filling in remaining info
                 * from that particular entry.
                 */
                info->rti_info[RTAX_GATEWAY] = rt->rt_gateway;
        }

        /*
         * Remove the item from the tree and return it.
         * Complain if it is not there and do no more processing.
         */
        *perror = ESRCH;
#ifdef RADIX_MPATH
        if (rt_mpath_capable(rnh))
                rn = rt_mpath_unlink(rnh, info, rt, perror);
        else
#endif
        rn = rnh->rnh_deladdr(dst, netmask, &rnh->head);
        if (rn == NULL)
                return (NULL);

        if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT))
                panic ("rtrequest delete");

        rt = RNTORT(rn);
        RT_LOCK(rt);
        RT_ADDREF(rt);
        rt->rt_flags &= ~RTF_UP;

        *perror = 0;

        return (rt);
}

static void
rt_notifydelete(struct rtentry *rt, struct rt_addrinfo *info)
{
        struct ifaddr *ifa;

        /*
         * give the protocol a chance to keep things in sync.
         */
        ifa = rt->rt_ifa;
        if (ifa != NULL && ifa->ifa_rtrequest != NULL)
                ifa->ifa_rtrequest(RTM_DELETE, rt, info);

        /*
         * One more rtentry floating around that is not
         * linked to the routing table. rttrash will be decremented
         * when RTFREE(rt) is eventually called.
         */
        V_rttrash++;
}


/*
 * These (questionable) definitions of apparent local variables apply
 * to the next two functions.  XXXXXX!!!
 */
#define dst     info->rti_info[RTAX_DST]
#define gateway info->rti_info[RTAX_GATEWAY]
#define netmask info->rti_info[RTAX_NETMASK]
#define ifaaddr info->rti_info[RTAX_IFA]
#define ifpaddr info->rti_info[RTAX_IFP]
#define flags   info->rti_flags

/*
 * Look up rt_addrinfo for a specific fib.  Note that if rti_ifa is defined,
 * it will be referenced so the caller must free it.
 */
int
rt_getifa_fib(struct rt_addrinfo *info, u_int fibnum)
{
        struct ifaddr *ifa;
        int error = 0;

        /*
         * ifp may be specified by sockaddr_dl
         * when protocol address is ambiguous.
         */
        if (info->rti_ifp == NULL && ifpaddr != NULL &&
            ifpaddr->sa_family == AF_LINK &&
            (ifa = ifa_ifwithnet(ifpaddr, 0, fibnum)) != NULL) {
                info->rti_ifp = ifa->ifa_ifp;
                ifa_free(ifa);
        }
        if (info->rti_ifa == NULL && ifaaddr != NULL)
                info->rti_ifa = ifa_ifwithaddr(ifaaddr);
        if (info->rti_ifa == NULL) {
                struct sockaddr *sa;

                sa = ifaaddr != NULL ? ifaaddr :
                    (gateway != NULL ? gateway : dst);
                if (sa != NULL && info->rti_ifp != NULL)
                        info->rti_ifa = ifaof_ifpforaddr(sa, info->rti_ifp);
                else if (dst != NULL && gateway != NULL)
                        info->rti_ifa = ifa_ifwithroute(flags, dst, gateway,
                                                        fibnum);
                else if (sa != NULL)
                        info->rti_ifa = ifa_ifwithroute(flags, sa, sa,
                                                        fibnum);
        }
        if ((ifa = info->rti_ifa) != NULL) {
                if (info->rti_ifp == NULL)
                        info->rti_ifp = ifa->ifa_ifp;
        } else
                error = ENETUNREACH;
        return (error);
}

static int
if_updatemtu_cb(struct radix_node *rn, void *arg)
{
        struct rtentry *rt;
        struct if_mtuinfo *ifmtu;

        rt = (struct rtentry *)rn;
        ifmtu = (struct if_mtuinfo *)arg;

        if (rt->rt_ifp != ifmtu->ifp)
                return (0);

        if (rt->rt_mtu >= ifmtu->mtu) {
                /* We have to decrease mtu regardless of flags */
                rt->rt_mtu = ifmtu->mtu;
                return (0);
        }

        /*
         * New MTU is bigger. Check if are allowed to alter it
         */
        if ((rt->rt_flags & (RTF_FIXEDMTU | RTF_GATEWAY | RTF_HOST)) != 0) {

                /*
                 * Skip routes with user-supplied MTU and
                 * non-interface routes
                 */
                return (0);
        }

        /* We are safe to update route MTU */
        rt->rt_mtu = ifmtu->mtu;

        return (0);
}

void
rt_updatemtu(struct ifnet *ifp)
{
        struct if_mtuinfo ifmtu;
        struct rib_head *rnh;
        int i, j;

        ifmtu.ifp = ifp;

        /*
         * Try to update rt_mtu for all routes using this interface
         * Unfortunately the only way to do this is to traverse all
         * routing tables in all fibs/domains.
         */
        for (i = 1; i <= AF_MAX; i++) {
                ifmtu.mtu = if_getmtu_family(ifp, i);
                for (j = 0; j < rt_numfibs; j++) {
                        rnh = rt_tables_get_rnh(j, i);
                        if (rnh == NULL)
                                continue;
                        RIB_WLOCK(rnh);
                        rnh->rnh_walktree(&rnh->head, if_updatemtu_cb, &ifmtu);
                        RIB_WUNLOCK(rnh);
                }
        }
}


#if 0
int p_sockaddr(char *buf, int buflen, struct sockaddr *s);
int rt_print(char *buf, int buflen, struct rtentry *rt);

int
p_sockaddr(char *buf, int buflen, struct sockaddr *s)
{
        void *paddr = NULL;

        switch (s->sa_family) {
        case AF_INET:
                paddr = &((struct sockaddr_in *)s)->sin_addr;
                break;
        case AF_INET6:
                paddr = &((struct sockaddr_in6 *)s)->sin6_addr;
                break;
        }

        if (paddr == NULL)
                return (0);

        if (inet_ntop(s->sa_family, paddr, buf, buflen) == NULL)
                return (0);
        
        return (strlen(buf));
}

int
rt_print(char *buf, int buflen, struct rtentry *rt)
{
        struct sockaddr *addr, *mask;
        int i = 0;

        addr = rt_key(rt);
        mask = rt_mask(rt);

        i = p_sockaddr(buf, buflen, addr);
        if (!(rt->rt_flags & RTF_HOST)) {
                buf[i++] = '/';
                i += p_sockaddr(buf + i, buflen - i, mask);
        }

        if (rt->rt_flags & RTF_GATEWAY) {
                buf[i++] = '>';
                i += p_sockaddr(buf + i, buflen - i, rt->rt_gateway);
        }

        return (i);
}
#endif

#ifdef RADIX_MPATH
/*
 * Deletes key for single-path routes, unlinks rtentry with
 * gateway specified in @info from multi-path routes.
 *
 * Returnes unlinked entry. In case of failure, returns NULL
 * and sets @perror to ESRCH.
 */
static struct radix_node *
rt_mpath_unlink(struct rib_head *rnh, struct rt_addrinfo *info,
    struct rtentry *rto, int *perror)
{
        /*
         * if we got multipath routes, we require users to specify
         * a matching RTAX_GATEWAY.
         */
        struct rtentry *rt; // *rto = NULL;
        struct radix_node *rn;
        struct sockaddr *gw;

        gw = info->rti_info[RTAX_GATEWAY];
        rt = rt_mpath_matchgate(rto, gw);
        if (rt == NULL) {
                *perror = ESRCH;
                return (NULL);
        }

        /*
         * this is the first entry in the chain
         */
        if (rto == rt) {
                rn = rn_mpath_next((struct radix_node *)rt);
                /*
                 * there is another entry, now it's active
                 */
                if (rn) {
                        rto = RNTORT(rn);
                        RT_LOCK(rto);
                        rto->rt_flags |= RTF_UP;
                        RT_UNLOCK(rto);
                } else if (rt->rt_flags & RTF_GATEWAY) {
                        /*
                         * For gateway routes, we need to 
                         * make sure that we we are deleting
                         * the correct gateway. 
                         * rt_mpath_matchgate() does not 
                         * check the case when there is only
                         * one route in the chain.  
                         */
                        if (gw &&
                            (rt->rt_gateway->sa_len != gw->sa_len ||
                                memcmp(rt->rt_gateway, gw, gw->sa_len))) {
                                *perror = ESRCH;
                                return (NULL);
                        }
                }

                /*
                 * use the normal delete code to remove
                 * the first entry
                 */
                rn = rnh->rnh_deladdr(dst, netmask, &rnh->head);
                *perror = 0;
                return (rn);
        }
                
        /*
         * if the entry is 2nd and on up
         */
        if (rt_mpath_deldup(rto, rt) == 0)
                panic ("rtrequest1: rt_mpath_deldup");
        *perror = 0;
        rn = (struct radix_node *)rt;
        return (rn);
}
#endif

#ifdef FLOWTABLE
static struct rtentry *
rt_flowtable_check_route(struct rib_head *rnh, struct rt_addrinfo *info)
{
#if defined(INET6) || defined(INET)
        struct radix_node *rn;
#endif
        struct rtentry *rt0;

        rt0 = NULL;
        /* "flow-table" only supports IPv6 and IPv4 at the moment. */
        switch (dst->sa_family) {
#ifdef INET6
        case AF_INET6:
#endif
#ifdef INET
        case AF_INET:
#endif
#if defined(INET6) || defined(INET)
                rn = rnh->rnh_matchaddr(dst, &rnh->head);
                if (rn && ((rn->rn_flags & RNF_ROOT) == 0)) {
                        struct sockaddr *mask;
                        u_char *m, *n;
                        int len;

                        /*
                         * compare mask to see if the new route is
                         * more specific than the existing one
                         */
                        rt0 = RNTORT(rn);
                        RT_LOCK(rt0);
                        RT_ADDREF(rt0);
                        RT_UNLOCK(rt0);
                        /*
                         * A host route is already present, so
                         * leave the flow-table entries as is.
                         */
                        if (rt0->rt_flags & RTF_HOST) {
                                RTFREE(rt0);
                                rt0 = NULL;
                        } else if (!(flags & RTF_HOST) && netmask) {
                                mask = rt_mask(rt0);
                                len = mask->sa_len;
                                m = (u_char *)mask;
                                n = (u_char *)netmask;
                                while (len-- > 0) {
                                        if (*n != *m)
                                                break;
                                        n++;
                                        m++;
                                }
                                if (len == 0 || (*n < *m)) {
                                        RTFREE(rt0);
                                        rt0 = NULL;
                                }
                        }
                }
#endif/* INET6 || INET */
        }

        return (rt0);
}
#endif

int
rtrequest1_fib(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt,
                                u_int fibnum)
{
        int error = 0;
        struct rtentry *rt, *rt_old;
#ifdef FLOWTABLE
        struct rtentry *rt0;
#endif
        struct radix_node *rn;
        struct rib_head *rnh;
        struct ifaddr *ifa;
        struct sockaddr *ndst;
        struct sockaddr_storage mdst;

        KASSERT((fibnum < rt_numfibs), ("rtrequest1_fib: bad fibnum"));
        KASSERT((flags & RTF_RNH_LOCKED) == 0, ("rtrequest1_fib: locked"));
        switch (dst->sa_family) {
        case AF_INET6:
        case AF_INET:
                /* We support multiple FIBs. */
                break;
        default:
                fibnum = RT_DEFAULT_FIB;
                break;
        }

        /*
         * Find the correct routing tree to use for this Address Family
         */
        rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
        if (rnh == NULL)
                return (EAFNOSUPPORT);

        /*
         * If we are adding a host route then we don't want to put
         * a netmask in the tree, nor do we want to clone it.
         */
        if (flags & RTF_HOST)
                netmask = NULL;

        switch (req) {
        case RTM_DELETE:
                if (netmask) {
                        rt_maskedcopy(dst, (struct sockaddr *)&mdst, netmask);
                        dst = (struct sockaddr *)&mdst;
                }

                RIB_WLOCK(rnh);
                rt = rt_unlinkrte(rnh, info, &error);
                RIB_WUNLOCK(rnh);
                if (error != 0)
                        return (error);

                rt_notifydelete(rt, info);

                /*
                 * If the caller wants it, then it can have it,
                 * but it's up to it to free the rtentry as we won't be
                 * doing it.
                 */
                if (ret_nrt) {
                        *ret_nrt = rt;
                        RT_UNLOCK(rt);
                } else
                        RTFREE_LOCKED(rt);
                break;
        case RTM_RESOLVE:
                /*
                 * resolve was only used for route cloning
                 * here for compat
                 */
                break;
        case RTM_ADD:
                if ((flags & RTF_GATEWAY) && !gateway)
                        return (EINVAL);
                if (dst && gateway && (dst->sa_family != gateway->sa_family) && 
                    (gateway->sa_family != AF_UNSPEC) && (gateway->sa_family != AF_LINK))
                        return (EINVAL);

                if (info->rti_ifa == NULL) {
                        error = rt_getifa_fib(info, fibnum);
                        if (error)
                                return (error);
                } else
                        ifa_ref(info->rti_ifa);
                ifa = info->rti_ifa;
                rt = uma_zalloc(V_rtzone, M_NOWAIT);
                if (rt == NULL) {
                        ifa_free(ifa);
                        return (ENOBUFS);
                }
                rt->rt_flags = RTF_UP | flags;
                rt->rt_fibnum = fibnum;
                /*
                 * Add the gateway. Possibly re-malloc-ing the storage for it.
                 */
                if ((error = rt_setgate(rt, dst, gateway)) != 0) {
                        ifa_free(ifa);
                        uma_zfree(V_rtzone, rt);
                        return (error);
                }

                /*
                 * point to the (possibly newly malloc'd) dest address.
                 */
                ndst = (struct sockaddr *)rt_key(rt);

                /*
                 * make sure it contains the value we want (masked if needed).
                 */
                if (netmask) {
                        rt_maskedcopy(dst, ndst, netmask);
                } else
                        bcopy(dst, ndst, dst->sa_len);

                /*
                 * We use the ifa reference returned by rt_getifa_fib().
                 * This moved from below so that rnh->rnh_addaddr() can
                 * examine the ifa and  ifa->ifa_ifp if it so desires.
                 */
                rt->rt_ifa = ifa;
                rt->rt_ifp = ifa->ifa_ifp;
                rt->rt_weight = 1;

                rt_setmetrics(info, rt);

                RIB_WLOCK(rnh);
                RT_LOCK(rt);
#ifdef RADIX_MPATH
                /* do not permit exactly the same dst/mask/gw pair */
                if (rt_mpath_capable(rnh) &&
                        rt_mpath_conflict(rnh, rt, netmask)) {
                        RIB_WUNLOCK(rnh);

                        ifa_free(rt->rt_ifa);
                        R_Free(rt_key(rt));
                        uma_zfree(V_rtzone, rt);
                        return (EEXIST);
                }
#endif

#ifdef FLOWTABLE
                rt0 = rt_flowtable_check_route(rnh, info);
#endif /* FLOWTABLE */

                /* XXX mtu manipulation will be done in rnh_addaddr -- itojun */
                rn = rnh->rnh_addaddr(ndst, netmask, &rnh->head, rt->rt_nodes);

                rt_old = NULL;
                if (rn == NULL && (info->rti_flags & RTF_PINNED) != 0) {

                        /*
                         * Force removal and re-try addition
                         * TODO: better multipath&pinned support
                         */
                        struct sockaddr *info_dst = info->rti_info[RTAX_DST];
                        info->rti_info[RTAX_DST] = ndst;
                        /* Do not delete existing PINNED(interface) routes */
                        info->rti_flags &= ~RTF_PINNED;
                        rt_old = rt_unlinkrte(rnh, info, &error);
                        info->rti_flags |= RTF_PINNED;
                        info->rti_info[RTAX_DST] = info_dst;
                        if (rt_old != NULL)
                                rn = rnh->rnh_addaddr(ndst, netmask, &rnh->head,
                                    rt->rt_nodes);
                }
                RIB_WUNLOCK(rnh);

                if (rt_old != NULL)
                        RT_UNLOCK(rt_old);

                /*
                 * If it still failed to go into the tree,
                 * then un-make it (this should be a function)
                 */
                if (rn == NULL) {
                        ifa_free(rt->rt_ifa);
                        R_Free(rt_key(rt));
                        uma_zfree(V_rtzone, rt);
#ifdef FLOWTABLE
                        if (rt0 != NULL)
                                RTFREE(rt0);
#endif
                        return (EEXIST);
                } 
#ifdef FLOWTABLE
                else if (rt0 != NULL) {
                        flowtable_route_flush(dst->sa_family, rt0);
                        RTFREE(rt0);
                }
#endif

                if (rt_old != NULL) {
                        rt_notifydelete(rt_old, info);
                        RTFREE(rt_old);
                }

                /*
                 * If this protocol has something to add to this then
                 * allow it to do that as well.
                 */
                if (ifa->ifa_rtrequest)
                        ifa->ifa_rtrequest(req, rt, info);

                /*
                 * actually return a resultant rtentry and
                 * give the caller a single reference.
                 */
                if (ret_nrt) {
                        *ret_nrt = rt;
                        RT_ADDREF(rt);
                }
                rnh->rnh_gen++;         /* Routing table updated */
                RT_UNLOCK(rt);
                break;
        case RTM_CHANGE:
                RIB_WLOCK(rnh);
                error = rtrequest1_fib_change(rnh, info, ret_nrt, fibnum);
                RIB_WUNLOCK(rnh);
                break;
        default:
                error = EOPNOTSUPP;
        }

        return (error);
}

#undef dst
#undef gateway
#undef netmask
#undef ifaaddr
#undef ifpaddr
#undef flags

static int
rtrequest1_fib_change(struct rib_head *rnh, struct rt_addrinfo *info,
    struct rtentry **ret_nrt, u_int fibnum)
{
        struct rtentry *rt = NULL;
        int error = 0;
        int free_ifa = 0;
        int family, mtu;
        struct if_mtuinfo ifmtu;

        rt = (struct rtentry *)rnh->rnh_lookup(info->rti_info[RTAX_DST],
            info->rti_info[RTAX_NETMASK], &rnh->head);

        if (rt == NULL)
                return (ESRCH);

#ifdef RADIX_MPATH
        /*
         * If we got multipath routes,
         * we require users to specify a matching RTAX_GATEWAY.
         */
        if (rt_mpath_capable(rnh)) {
                rt = rt_mpath_matchgate(rt, info->rti_info[RTAX_GATEWAY]);
                if (rt == NULL)
                        return (ESRCH);
        }
#endif

        RT_LOCK(rt);

        rt_setmetrics(info, rt);

        /*
         * 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 (((rt->rt_flags & RTF_GATEWAY) &&
            info->rti_info[RTAX_GATEWAY] != NULL) ||
            info->rti_info[RTAX_IFP] != NULL ||
            (info->rti_info[RTAX_IFA] != NULL &&
             !sa_equal(info->rti_info[RTAX_IFA], rt->rt_ifa->ifa_addr))) {

                error = rt_getifa_fib(info, fibnum);
                if (info->rti_ifa != NULL)
                        free_ifa = 1;

                if (error != 0)
                        goto bad;
        }

        /* Check if outgoing interface has changed */
        if (info->rti_ifa != NULL && info->rti_ifa != rt->rt_ifa &&
            rt->rt_ifa != NULL && rt->rt_ifa->ifa_rtrequest != NULL) {
                rt->rt_ifa->ifa_rtrequest(RTM_DELETE, rt, info);
                ifa_free(rt->rt_ifa);
        }
        /* Update gateway address */
        if (info->rti_info[RTAX_GATEWAY] != NULL) {
                error = rt_setgate(rt, rt_key(rt), info->rti_info[RTAX_GATEWAY]);
                if (error != 0)
                        goto bad;

                rt->rt_flags &= ~RTF_GATEWAY;
                rt->rt_flags |= (RTF_GATEWAY & info->rti_flags);
        }

        if (info->rti_ifa != NULL && info->rti_ifa != rt->rt_ifa) {
                ifa_ref(info->rti_ifa);
                rt->rt_ifa = info->rti_ifa;
                rt->rt_ifp = info->rti_ifp;
        }
        /* Allow some flags to be toggled on change. */
        rt->rt_flags &= ~RTF_FMASK;
        rt->rt_flags |= info->rti_flags & RTF_FMASK;

        if (rt->rt_ifa && rt->rt_ifa->ifa_rtrequest != NULL)
               rt->rt_ifa->ifa_rtrequest(RTM_ADD, rt, info);

        /* Alter route MTU if necessary */
        if (rt->rt_ifp != NULL) {
                family = info->rti_info[RTAX_DST]->sa_family;
                mtu = if_getmtu_family(rt->rt_ifp, family);
                /* Set default MTU */
                if (rt->rt_mtu == 0)
                        rt->rt_mtu = mtu;
                if (rt->rt_mtu != mtu) {
                        /* Check if we really need to update */
                        ifmtu.ifp = rt->rt_ifp;
                        ifmtu.mtu = mtu;
                        if_updatemtu_cb(rt->rt_nodes, &ifmtu);
                }
        }

        if (ret_nrt) {
                *ret_nrt = rt;
                RT_ADDREF(rt);
        }
bad:
        RT_UNLOCK(rt);
        if (free_ifa != 0)
                ifa_free(info->rti_ifa);
        return (error);
}

static void
rt_setmetrics(const struct rt_addrinfo *info, struct rtentry *rt)
{

        if (info->rti_mflags & RTV_MTU) {
                if (info->rti_rmx->rmx_mtu != 0) {

                        /*
                         * MTU was explicitly provided by user.
                         * Keep it.
                         */
                        rt->rt_flags |= RTF_FIXEDMTU;
                } else {

                        /*
                         * User explicitly sets MTU to 0.
                         * Assume rollback to default.
                         */
                        rt->rt_flags &= ~RTF_FIXEDMTU;
                }
                rt->rt_mtu = info->rti_rmx->rmx_mtu;
        }
        if (info->rti_mflags & RTV_WEIGHT)
                rt->rt_weight = info->rti_rmx->rmx_weight;
        /* Kernel -> userland timebase conversion. */
        if (info->rti_mflags & RTV_EXPIRE)
                rt->rt_expire = info->rti_rmx->rmx_expire ?
                    info->rti_rmx->rmx_expire - time_second + time_uptime : 0;
}

int
rt_setgate(struct rtentry *rt, struct sockaddr *dst, struct sockaddr *gate)
{
        /* XXX dst may be overwritten, can we move this to below */
        int dlen = SA_SIZE(dst), glen = SA_SIZE(gate);

        /*
         * Prepare to store the gateway in rt->rt_gateway.
         * Both dst and gateway are stored one after the other in the same
         * malloc'd chunk. If we have room, we can reuse the old buffer,
         * rt_gateway already points to the right place.
         * Otherwise, malloc a new block and update the 'dst' address.
         */
        if (rt->rt_gateway == NULL || glen > SA_SIZE(rt->rt_gateway)) {
                caddr_t new;

                R_Malloc(new, caddr_t, dlen + glen);
                if (new == NULL)
                        return ENOBUFS;
                /*
                 * XXX note, we copy from *dst and not *rt_key(rt) because
                 * rt_setgate() can be called to initialize a newly
                 * allocated route entry, in which case rt_key(rt) == NULL
                 * (and also rt->rt_gateway == NULL).
                 * Free()/free() handle a NULL argument just fine.
                 */
                bcopy(dst, new, dlen);
                R_Free(rt_key(rt));     /* free old block, if any */
                rt_key(rt) = (struct sockaddr *)new;
                rt->rt_gateway = (struct sockaddr *)(new + dlen);
        }

        /*
         * Copy the new gateway value into the memory chunk.
         */
        bcopy(gate, rt->rt_gateway, glen);

        return (0);
}

void
rt_maskedcopy(struct sockaddr *src, struct sockaddr *dst, struct sockaddr *netmask)
{
        u_char *cp1 = (u_char *)src;
        u_char *cp2 = (u_char *)dst;
        u_char *cp3 = (u_char *)netmask;
        u_char *cplim = cp2 + *cp3;
        u_char *cplim2 = cp2 + *cp1;

        *cp2++ = *cp1++; *cp2++ = *cp1++; /* copies sa_len & sa_family */
        cp3 += 2;
        if (cplim > cplim2)
                cplim = cplim2;
        while (cp2 < cplim)
                *cp2++ = *cp1++ & *cp3++;
        if (cp2 < cplim2)
                bzero((caddr_t)cp2, (unsigned)(cplim2 - cp2));
}

/*
 * Set up a routing table entry, normally
 * for an interface.
 */
#define _SOCKADDR_TMPSIZE 128 /* Not too big.. kernel stack size is limited */
static inline  int
rtinit1(struct ifaddr *ifa, int cmd, int flags, int fibnum)
{
        struct sockaddr *dst;
        struct sockaddr *netmask;
        struct rtentry *rt = NULL;
        struct rt_addrinfo info;
        int error = 0;
        int startfib, endfib;
        char tempbuf[_SOCKADDR_TMPSIZE];
        int didwork = 0;
        int a_failure = 0;
        static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
        struct rib_head *rnh;

        if (flags & RTF_HOST) {
                dst = ifa->ifa_dstaddr;
                netmask = NULL;
        } else {
                dst = ifa->ifa_addr;
                netmask = ifa->ifa_netmask;
        }
        if (dst->sa_len == 0)
                return(EINVAL);
        switch (dst->sa_family) {
        case AF_INET6:
        case AF_INET:
                /* We support multiple FIBs. */
                break;
        default:
                fibnum = RT_DEFAULT_FIB;
                break;
        }
        if (fibnum == RT_ALL_FIBS) {
                if (V_rt_add_addr_allfibs == 0 && cmd == (int)RTM_ADD)
                        startfib = endfib = ifa->ifa_ifp->if_fib;
                else {
                        startfib = 0;
                        endfib = rt_numfibs - 1;
                }
        } else {
                KASSERT((fibnum < rt_numfibs), ("rtinit1: bad fibnum"));
                startfib = fibnum;
                endfib = fibnum;
        }

        /*
         * If it's a delete, check that if it exists,
         * it's on the correct interface or we might scrub
         * a route to another ifa which would
         * be confusing at best and possibly worse.
         */
        if (cmd == RTM_DELETE) {
                /*
                 * It's a delete, so it should already exist..
                 * If it's a net, mask off the host bits
                 * (Assuming we have a mask)
                 * XXX this is kinda inet specific..
                 */
                if (netmask != NULL) {
                        rt_maskedcopy(dst, (struct sockaddr *)tempbuf, netmask);
                        dst = (struct sockaddr *)tempbuf;
                }
        }
        /*
         * Now go through all the requested tables (fibs) and do the
         * requested action. Realistically, this will either be fib 0
         * for protocols that don't do multiple tables or all the
         * tables for those that do.
         */
        for ( fibnum = startfib; fibnum <= endfib; fibnum++) {
                if (cmd == RTM_DELETE) {
                        struct radix_node *rn;
                        /*
                         * Look up an rtentry that is in the routing tree and
                         * contains the correct info.
                         */
                        rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
                        if (rnh == NULL)
                                /* this table doesn't exist but others might */
                                continue;
                        RIB_RLOCK(rnh);
                        rn = rnh->rnh_lookup(dst, netmask, &rnh->head);
#ifdef RADIX_MPATH
                        if (rt_mpath_capable(rnh)) {

                                if (rn == NULL) 
                                        error = ESRCH;
                                else {
                                        rt = RNTORT(rn);
                                        /*
                                         * for interface route the
                                         * rt->rt_gateway is sockaddr_intf
                                         * for cloning ARP entries, so
                                         * rt_mpath_matchgate must use the
                                         * interface address
                                         */
                                        rt = rt_mpath_matchgate(rt,
                                            ifa->ifa_addr);
                                        if (rt == NULL) 
                                                error = ESRCH;
                                }
                        }
#endif
                        error = (rn == NULL ||
                            (rn->rn_flags & RNF_ROOT) ||
                            RNTORT(rn)->rt_ifa != ifa);
                        RIB_RUNLOCK(rnh);
                        if (error) {
                                /* this is only an error if bad on ALL tables */
                                continue;
                        }
                }
                /*
                 * Do the actual request
                 */
                bzero((caddr_t)&info, sizeof(info));
                info.rti_ifa = ifa;
                info.rti_flags = flags |
                    (ifa->ifa_flags & ~IFA_RTSELF) | RTF_PINNED;
                info.rti_info[RTAX_DST] = dst;
                /* 
                 * doing this for compatibility reasons
                 */
                if (cmd == RTM_ADD)
                        info.rti_info[RTAX_GATEWAY] =
                            (struct sockaddr *)&null_sdl;
                else
                        info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr;
                info.rti_info[RTAX_NETMASK] = netmask;
                error = rtrequest1_fib(cmd, &info, &rt, fibnum);

                if (error == 0 && rt != NULL) {
                        /*
                         * notify any listening routing agents of the change
                         */
                        RT_LOCK(rt);
#ifdef RADIX_MPATH
                        /*
                         * in case address alias finds the first address
                         * e.g. ifconfig bge0 192.0.2.246/24
                         * e.g. ifconfig bge0 192.0.2.247/24
                         * the address set in the route is 192.0.2.246
                         * so we need to replace it with 192.0.2.247
                         */
                        if (memcmp(rt->rt_ifa->ifa_addr,
                            ifa->ifa_addr, ifa->ifa_addr->sa_len)) {
                                ifa_free(rt->rt_ifa);
                                ifa_ref(ifa);
                                rt->rt_ifp = ifa->ifa_ifp;
                                rt->rt_ifa = ifa;
                        }
#endif
                        /* 
                         * doing this for compatibility reasons
                         */
                        if (cmd == RTM_ADD) {
                            ((struct sockaddr_dl *)rt->rt_gateway)->sdl_type  =
                                rt->rt_ifp->if_type;
                            ((struct sockaddr_dl *)rt->rt_gateway)->sdl_index =
                                rt->rt_ifp->if_index;
                        }
                        RT_ADDREF(rt);
                        RT_UNLOCK(rt);
                        rt_newaddrmsg_fib(cmd, ifa, error, rt, fibnum);
                        RT_LOCK(rt);
                        RT_REMREF(rt);
                        if (cmd == RTM_DELETE) {
                                /*
                                 * If we are deleting, and we found an entry,
                                 * then it's been removed from the tree..
                                 * now throw it away.
                                 */
                                RTFREE_LOCKED(rt);
                        } else {
                                if (cmd == RTM_ADD) {
                                        /*
                                         * We just wanted to add it..
                                         * we don't actually need a reference.
                                         */
                                        RT_REMREF(rt);
                                }
                                RT_UNLOCK(rt);
                        }
                        didwork = 1;
                }
                if (error)
                        a_failure = error;
        }
        if (cmd == RTM_DELETE) {
                if (didwork) {
                        error = 0;
                } else {
                        /* we only give an error if it wasn't in any table */
                        error = ((flags & RTF_HOST) ?
                            EHOSTUNREACH : ENETUNREACH);
                }
        } else {
                if (a_failure) {
                        /* return an error if any of them failed */
                        error = a_failure;
                }
        }
        return (error);
}

/*
 * Set up a routing table entry, normally
 * for an interface.
 */
int
rtinit(struct ifaddr *ifa, int cmd, int flags)
{
        struct sockaddr *dst;
        int fib = RT_DEFAULT_FIB;

        if (flags & RTF_HOST) {
                dst = ifa->ifa_dstaddr;
        } else {
                dst = ifa->ifa_addr;
        }

        switch (dst->sa_family) {
        case AF_INET6:
        case AF_INET:
                /* We do support multiple FIBs. */
                fib = RT_ALL_FIBS;
                break;
        }
        return (rtinit1(ifa, cmd, flags, fib));
}

/*
 * Announce interface address arrival/withdraw
 * Returns 0 on success.
 */
int
rt_addrmsg(int cmd, struct ifaddr *ifa, int fibnum)
{

        KASSERT(cmd == RTM_ADD || cmd == RTM_DELETE,
            ("unexpected cmd %d", cmd));
        
        KASSERT(fibnum == RT_ALL_FIBS || (fibnum >= 0 && fibnum < rt_numfibs),
            ("%s: fib out of range 0 <=%d<%d", __func__, fibnum, rt_numfibs));

#if defined(INET) || defined(INET6)
#ifdef SCTP
        /*
         * notify the SCTP stack
         * this will only get called when an address is added/deleted
         * XXX pass the ifaddr struct instead if ifa->ifa_addr...
         */
        sctp_addr_change(ifa, cmd);
#endif /* SCTP */
#endif
        return (rtsock_addrmsg(cmd, ifa, fibnum));
}

/*
 * Announce route addition/removal.
 * Users of this function MUST validate input data BEFORE calling.
 * However we have to be able to handle invalid data:
 * if some userland app sends us "invalid" route message (invalid mask,
 * no dst, wrong address families, etc...) we need to pass it back
 * to app (and any other rtsock consumers) with rtm_errno field set to
 * non-zero value.
 * Returns 0 on success.
 */
int
rt_routemsg(int cmd, struct ifnet *ifp, int error, struct rtentry *rt,
    int fibnum)
{

        KASSERT(cmd == RTM_ADD || cmd == RTM_DELETE,
            ("unexpected cmd %d", cmd));
        
        KASSERT(fibnum == RT_ALL_FIBS || (fibnum >= 0 && fibnum < rt_numfibs),
            ("%s: fib out of range 0 <=%d<%d", __func__, fibnum, rt_numfibs));

        KASSERT(rt_key(rt) != NULL, (":%s: rt_key must be supplied", __func__));

        return (rtsock_routemsg(cmd, ifp, error, rt, fibnum));
}

void
rt_newaddrmsg(int cmd, struct ifaddr *ifa, int error, struct rtentry *rt)
{

        rt_newaddrmsg_fib(cmd, ifa, error, rt, RT_ALL_FIBS);
}

/*
 * This is called to generate messages from the routing socket
 * indicating a network interface has had addresses associated with it.
 */
void
rt_newaddrmsg_fib(int cmd, struct ifaddr *ifa, int error, struct rtentry *rt,
    int fibnum)
{

        KASSERT(cmd == RTM_ADD || cmd == RTM_DELETE,
                ("unexpected cmd %u", cmd));
        KASSERT(fibnum == RT_ALL_FIBS || (fibnum >= 0 && fibnum < rt_numfibs),
            ("%s: fib out of range 0 <=%d<%d", __func__, fibnum, rt_numfibs));

        if (cmd == RTM_ADD) {
                rt_addrmsg(cmd, ifa, fibnum);
                if (rt != NULL)
                        rt_routemsg(cmd, ifa->ifa_ifp, error, rt, fibnum);
        } else {
                if (rt != NULL)
                        rt_routemsg(cmd, ifa->ifa_ifp, error, rt, fibnum);
                rt_addrmsg(cmd, ifa, fibnum);
        }
}