FreeBSD/Linux Kernel Cross Reference
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: releng/11.0/sys/net/route.c 302054 2016-06-21 13:48:49Z bz $
     */
    /************************************************************************
     * 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);
          }
  }
  

Cache object: e54128347a0aaa32058ad799ff84653a