FreeBSD/Linux Kernel Cross Reference
sys/netinet6/in6_fib.c

     /*-
      * Copyright (c) 2015
      *      Alexander V. Chernikov <melifaro@FreeBSD.org>
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. 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.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/12.0/sys/netinet6/in6_fib.c 335250 2018-06-16 08:26:23Z ae $");
    
    #include "opt_inet.h"
    #include "opt_inet6.h"
    #include "opt_route.h"
    #include "opt_mpath.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/lock.h>
    #include <sys/rmlock.h>
    #include <sys/malloc.h>
    #include <sys/mbuf.h>
    #include <sys/socket.h>
    #include <sys/sysctl.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>
    
    #ifdef RADIX_MPATH
    #include <net/radix_mpath.h>
    #endif
    
    #include <netinet/in.h>
    #include <netinet/in_var.h>
    #include <netinet/ip_mroute.h>
    #include <netinet/ip6.h>
    #include <netinet6/in6_fib.h>
    #include <netinet6/in6_var.h>
    #include <netinet6/nd6.h>
    #include <netinet6/scope6_var.h>
    
    #include <net/if_types.h>
    
    #ifdef INET6
    static void fib6_rte_to_nh_extended(struct rtentry *rte,
        const struct in6_addr *dst, uint32_t flags, struct nhop6_extended *pnh6);
    static void fib6_rte_to_nh_basic(struct rtentry *rte, const struct in6_addr *dst,
        uint32_t flags, struct nhop6_basic *pnh6);
    static struct ifnet *fib6_get_ifaifp(struct rtentry *rte);
    #define RNTORT(p)       ((struct rtentry *)(p))
    
    /*
     * Gets real interface for the @rte.
     * Returns rt_ifp for !IFF_LOOPBACK routers.
     * Extracts "real" address interface from interface address
     * loopback routes.
     */
    static struct ifnet *
    fib6_get_ifaifp(struct rtentry *rte)
    {
            struct ifnet *ifp;
            struct sockaddr_dl *sdl;
    
            ifp = rte->rt_ifp;
            if ((ifp->if_flags & IFF_LOOPBACK) &&
                rte->rt_gateway->sa_family == AF_LINK) {
                    sdl = (struct sockaddr_dl *)rte->rt_gateway;
                    return (ifnet_byindex(sdl->sdl_index));
            }
    
            return (ifp);
    }
    
   static void
   fib6_rte_to_nh_basic(struct rtentry *rte, const struct in6_addr *dst,
       uint32_t flags, struct nhop6_basic *pnh6)
   {
           struct sockaddr_in6 *gw;
   
           /* Do explicit nexthop zero unless we're copying it */
           memset(pnh6, 0, sizeof(*pnh6));
   
           if ((flags & NHR_IFAIF) != 0)
                   pnh6->nh_ifp = fib6_get_ifaifp(rte);
           else
                   pnh6->nh_ifp = rte->rt_ifp;
   
           pnh6->nh_mtu = min(rte->rt_mtu, IN6_LINKMTU(rte->rt_ifp));
           if (rte->rt_flags & RTF_GATEWAY) {
                   gw = (struct sockaddr_in6 *)rte->rt_gateway;
                   pnh6->nh_addr = gw->sin6_addr;
                   in6_clearscope(&pnh6->nh_addr);
           } else
                   pnh6->nh_addr = *dst;
           /* Set flags */
           pnh6->nh_flags = fib_rte_to_nh_flags(rte->rt_flags);
           gw = (struct sockaddr_in6 *)rt_key(rte);
           if (IN6_IS_ADDR_UNSPECIFIED(&gw->sin6_addr))
                   pnh6->nh_flags |= NHF_DEFAULT;
   }
   
   static void
   fib6_rte_to_nh_extended(struct rtentry *rte, const struct in6_addr *dst,
       uint32_t flags, struct nhop6_extended *pnh6)
   {
           struct sockaddr_in6 *gw;
   
           /* Do explicit nexthop zero unless we're copying it */
           memset(pnh6, 0, sizeof(*pnh6));
   
           if ((flags & NHR_IFAIF) != 0)
                   pnh6->nh_ifp = fib6_get_ifaifp(rte);
           else
                   pnh6->nh_ifp = rte->rt_ifp;
   
           pnh6->nh_mtu = min(rte->rt_mtu, IN6_LINKMTU(rte->rt_ifp));
           if (rte->rt_flags & RTF_GATEWAY) {
                   gw = (struct sockaddr_in6 *)rte->rt_gateway;
                   pnh6->nh_addr = gw->sin6_addr;
                   in6_clearscope(&pnh6->nh_addr);
           } else
                   pnh6->nh_addr = *dst;
           /* Set flags */
           pnh6->nh_flags = fib_rte_to_nh_flags(rte->rt_flags);
           gw = (struct sockaddr_in6 *)rt_key(rte);
           if (IN6_IS_ADDR_UNSPECIFIED(&gw->sin6_addr))
                   pnh6->nh_flags |= NHF_DEFAULT;
   }
   
   /*
    * Performs IPv6 route table lookup on @dst. Returns 0 on success.
    * Stores basic nexthop info into provided @pnh6 structure.
    * Note that
    * - nh_ifp represents logical transmit interface (rt_ifp) by default
    * - nh_ifp represents "address" interface if NHR_IFAIF flag is passed
    * - mtu from logical transmit interface will be returned.
    * - nh_ifp cannot be safely dereferenced
    * - nh_ifp represents rt_ifp (e.g. if looking up address on
    *   interface "ix0" pointer to "ix0" interface will be returned instead
    *   of "lo0")
    * - howewer mtu from "transmit" interface will be returned.
    * - scope will be embedded in nh_addr
    */
   int
   fib6_lookup_nh_basic(uint32_t fibnum, const struct in6_addr *dst, uint32_t scopeid,
       uint32_t flags, uint32_t flowid, struct nhop6_basic *pnh6)
   {
           RIB_RLOCK_TRACKER;
           struct rib_head *rh;
           struct radix_node *rn;
           struct sockaddr_in6 sin6;
           struct rtentry *rte;
   
           KASSERT((fibnum < rt_numfibs), ("fib6_lookup_nh_basic: bad fibnum"));
           rh = rt_tables_get_rnh(fibnum, AF_INET6);
           if (rh == NULL)
                   return (ENOENT);
   
           /* Prepare lookup key */
           memset(&sin6, 0, sizeof(sin6));
           sin6.sin6_addr = *dst;
           sin6.sin6_len = sizeof(struct sockaddr_in6);
           /* Assume scopeid is valid and embed it directly */
           if (IN6_IS_SCOPE_LINKLOCAL(dst))
                   sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
   
           RIB_RLOCK(rh);
           rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
           if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
                   rte = RNTORT(rn);
                   /* Ensure route & ifp is UP */
                   if (RT_LINK_IS_UP(rte->rt_ifp)) {
                           fib6_rte_to_nh_basic(rte, &sin6.sin6_addr, flags, pnh6);
                           RIB_RUNLOCK(rh);
                           return (0);
                   }
           }
           RIB_RUNLOCK(rh);
   
           return (ENOENT);
   }
   
   /*
    * Performs IPv6 route table lookup on @dst. Returns 0 on success.
    * Stores extended nexthop info into provided @pnh6 structure.
    * Note that
    * - nh_ifp cannot be safely dereferenced unless NHR_REF is specified.
    * - in that case you need to call fib6_free_nh_ext()
    * - nh_ifp represents logical transmit interface (rt_ifp) by default
    * - nh_ifp represents "address" interface if NHR_IFAIF flag is passed
    * - mtu from logical transmit interface will be returned.
    * - scope will be embedded in nh_addr
    */
   int
   fib6_lookup_nh_ext(uint32_t fibnum, const struct in6_addr *dst,uint32_t scopeid,
       uint32_t flags, uint32_t flowid, struct nhop6_extended *pnh6)
   {
           RIB_RLOCK_TRACKER;
           struct rib_head *rh;
           struct radix_node *rn;
           struct sockaddr_in6 sin6;
           struct rtentry *rte;
   
           KASSERT((fibnum < rt_numfibs), ("fib6_lookup_nh_ext: bad fibnum"));
           rh = rt_tables_get_rnh(fibnum, AF_INET6);
           if (rh == NULL)
                   return (ENOENT);
   
           /* Prepare lookup key */
           memset(&sin6, 0, sizeof(sin6));
           sin6.sin6_len = sizeof(struct sockaddr_in6);
           sin6.sin6_addr = *dst;
           /* Assume scopeid is valid and embed it directly */
           if (IN6_IS_SCOPE_LINKLOCAL(dst))
                   sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
   
           RIB_RLOCK(rh);
           rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
           if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
                   rte = RNTORT(rn);
   #ifdef RADIX_MPATH
                   rte = rt_mpath_select(rte, flowid);
                   if (rte == NULL) {
                           RIB_RUNLOCK(rh);
                           return (ENOENT);
                   }
   #endif
                   /* Ensure route & ifp is UP */
                   if (RT_LINK_IS_UP(rte->rt_ifp)) {
                           fib6_rte_to_nh_extended(rte, &sin6.sin6_addr, flags,
                               pnh6);
                           if ((flags & NHR_REF) != 0) {
                                   /* TODO: Do lwref on egress ifp's */
                           }
                           RIB_RUNLOCK(rh);
   
                           return (0);
                   }
           }
           RIB_RUNLOCK(rh);
   
           return (ENOENT);
   }
   
   void
   fib6_free_nh_ext(uint32_t fibnum, struct nhop6_extended *pnh6)
   {
   
   }
   
   #endif
   

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