The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/net/route.c

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    1 /*
    2  * Copyright (c) 1980, 1986, 1991, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 3. All advertising materials mentioning features or use of this software
   14  *    must display the following acknowledgement:
   15  *      This product includes software developed by the University of
   16  *      California, Berkeley and its contributors.
   17  * 4. Neither the name of the University nor the names of its contributors
   18  *    may be used to endorse or promote products derived from this software
   19  *    without specific prior written permission.
   20  *
   21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   31  * SUCH DAMAGE.
   32  *
   33  *      @(#)route.c     8.3 (Berkeley) 1/9/95
   34  * $FreeBSD: releng/5.0/sys/net/route.c 106968 2002-11-15 22:53:53Z luigi $
   35  */
   36 
   37 #include "opt_inet.h"
   38 #include "opt_mrouting.h"
   39 
   40 #include <sys/param.h>
   41 #include <sys/systm.h>
   42 #include <sys/malloc.h>
   43 #include <sys/mbuf.h>
   44 #include <sys/socket.h>
   45 #include <sys/domain.h>
   46 #include <sys/kernel.h>
   47 
   48 #include <net/if.h>
   49 #include <net/route.h>
   50 
   51 #include <netinet/in.h>
   52 #include <netinet/ip_mroute.h>
   53 
   54 #define SA(p) ((struct sockaddr *)(p))
   55 
   56 struct route_cb route_cb;
   57 static struct rtstat rtstat;
   58 struct radix_node_head *rt_tables[AF_MAX+1];
   59 
   60 static int      rttrash;                /* routes not in table but not freed */
   61 
   62 static void rt_maskedcopy(struct sockaddr *,
   63             struct sockaddr *, struct sockaddr *);
   64 static void rtable_init(void **);
   65 
   66 static void
   67 rtable_init(table)
   68         void **table;
   69 {
   70         struct domain *dom;
   71         for (dom = domains; dom; dom = dom->dom_next)
   72                 if (dom->dom_rtattach)
   73                         dom->dom_rtattach(&table[dom->dom_family],
   74                             dom->dom_rtoffset);
   75 }
   76 
   77 void
   78 route_init()
   79 {
   80         rn_init();      /* initialize all zeroes, all ones, mask table */
   81         rtable_init((void **)rt_tables);
   82 }
   83 
   84 /*
   85  * Packet routing routines.
   86  */
   87 void
   88 rtalloc(ro)
   89         register struct route *ro;
   90 {
   91         rtalloc_ign(ro, 0UL);
   92 }
   93 
   94 void
   95 rtalloc_ign(ro, ignore)
   96         register struct route *ro;
   97         u_long ignore;
   98 {
   99         struct rtentry *rt;
  100         int s;
  101 
  102         if ((rt = ro->ro_rt) != NULL) {
  103                 if (rt->rt_ifp != NULL && rt->rt_flags & RTF_UP)
  104                         return;
  105                 /* XXX - We are probably always at splnet here already. */
  106                 s = splnet();
  107                 RTFREE(rt);
  108                 ro->ro_rt = NULL;
  109                 splx(s);
  110         }
  111         ro->ro_rt = rtalloc1(&ro->ro_dst, 1, ignore);
  112 }
  113 
  114 /*
  115  * Look up the route that matches the address given
  116  * Or, at least try.. Create a cloned route if needed.
  117  */
  118 struct rtentry *
  119 rtalloc1(dst, report, ignflags)
  120         register struct sockaddr *dst;
  121         int report;
  122         u_long ignflags;
  123 {
  124         register struct radix_node_head *rnh = rt_tables[dst->sa_family];
  125         register struct rtentry *rt;
  126         register struct radix_node *rn;
  127         struct rtentry *newrt = 0;
  128         struct rt_addrinfo info;
  129         u_long nflags;
  130         int  s = splnet(), err = 0, msgtype = RTM_MISS;
  131 
  132         /*
  133          * Look up the address in the table for that Address Family
  134          */
  135         if (rnh && (rn = rnh->rnh_matchaddr((caddr_t)dst, rnh)) &&
  136             ((rn->rn_flags & RNF_ROOT) == 0)) {
  137                 /*
  138                  * If we find it and it's not the root node, then
  139                  * get a refernce on the rtentry associated.
  140                  */
  141                 newrt = rt = (struct rtentry *)rn;
  142                 nflags = rt->rt_flags & ~ignflags;
  143                 if (report && (nflags & (RTF_CLONING | RTF_PRCLONING))) {
  144                         /*
  145                          * We are apparently adding (report = 0 in delete).
  146                          * If it requires that it be cloned, do so.
  147                          * (This implies it wasn't a HOST route.)
  148                          */
  149                         err = rtrequest(RTM_RESOLVE, dst, SA(0),
  150                                               SA(0), 0, &newrt);
  151                         if (err) {
  152                                 /*
  153                                  * If the cloning didn't succeed, maybe
  154                                  * what we have will do. Return that.
  155                                  */
  156                                 newrt = rt;
  157                                 rt->rt_refcnt++;
  158                                 goto miss;
  159                         }
  160                         if ((rt = newrt) && (rt->rt_flags & RTF_XRESOLVE)) {
  161                                 /*
  162                                  * If the new route specifies it be
  163                                  * externally resolved, then go do that.
  164                                  */
  165                                 msgtype = RTM_RESOLVE;
  166                                 goto miss;
  167                         }
  168                         /* Inform listeners of the new route. */
  169                         bzero(&info, sizeof(info));
  170                         info.rti_info[RTAX_DST] = rt_key(rt);
  171                         info.rti_info[RTAX_NETMASK] = rt_mask(rt);
  172                         info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
  173                         if (rt->rt_ifp != NULL) {
  174                                 info.rti_info[RTAX_IFP] =
  175                                     TAILQ_FIRST(&rt->rt_ifp->if_addrhead)->ifa_addr;
  176                                 info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
  177                         }
  178                         rt_missmsg(RTM_ADD, &info, rt->rt_flags, 0);
  179                 } else
  180                         rt->rt_refcnt++;
  181         } else {
  182                 /*
  183                  * Either we hit the root or couldn't find any match,
  184                  * Which basically means
  185                  * "caint get there frm here"
  186                  */
  187                 rtstat.rts_unreach++;
  188         miss:   if (report) {
  189                         /*
  190                          * If required, report the failure to the supervising
  191                          * Authorities.
  192                          * For a delete, this is not an error. (report == 0)
  193                          */
  194                         bzero((caddr_t)&info, sizeof(info));
  195                         info.rti_info[RTAX_DST] = dst;
  196                         rt_missmsg(msgtype, &info, 0, err);
  197                 }
  198         }
  199         splx(s);
  200         return (newrt);
  201 }
  202 
  203 /*
  204  * Remove a reference count from an rtentry.
  205  * If the count gets low enough, take it out of the routing table
  206  */
  207 void
  208 rtfree(rt)
  209         register struct rtentry *rt;
  210 {
  211         /*
  212          * find the tree for that address family
  213          */
  214         register struct radix_node_head *rnh =
  215                 rt_tables[rt_key(rt)->sa_family];
  216         register struct ifaddr *ifa;
  217 
  218         if (rt == 0 || rnh == 0)
  219                 panic("rtfree");
  220 
  221         /*
  222          * decrement the reference count by one and if it reaches 0,
  223          * and there is a close function defined, call the close function
  224          */
  225         rt->rt_refcnt--;
  226         if(rnh->rnh_close && rt->rt_refcnt == 0) {
  227                 rnh->rnh_close((struct radix_node *)rt, rnh);
  228         }
  229 
  230         /*
  231          * If we are no longer "up" (and ref == 0)
  232          * then we can free the resources associated
  233          * with the route.
  234          */
  235         if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_UP) == 0) {
  236                 if (rt->rt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT))
  237                         panic ("rtfree 2");
  238                 /*
  239                  * the rtentry must have been removed from the routing table
  240                  * so it is represented in rttrash.. remove that now.
  241                  */
  242                 rttrash--;
  243 
  244 #ifdef  DIAGNOSTIC
  245                 if (rt->rt_refcnt < 0) {
  246                         printf("rtfree: %p not freed (neg refs)\n", rt);
  247                         return;
  248                 }
  249 #endif
  250 
  251                 /*
  252                  * release references on items we hold them on..
  253                  * e.g other routes and ifaddrs.
  254                  */
  255                 if((ifa = rt->rt_ifa))
  256                         IFAFREE(ifa);
  257                 if (rt->rt_parent) {
  258                         RTFREE(rt->rt_parent);
  259                 }
  260 
  261                 /*
  262                  * The key is separatly alloc'd so free it (see rt_setgate()).
  263                  * This also frees the gateway, as they are always malloc'd
  264                  * together.
  265                  */
  266                 Free(rt_key(rt));
  267 
  268                 /*
  269                  * and the rtentry itself of course
  270                  */
  271                 Free(rt);
  272         }
  273 }
  274 
  275 void
  276 ifafree(ifa)
  277         register struct ifaddr *ifa;
  278 {
  279         if (ifa == NULL)
  280                 panic("ifafree");
  281         if (ifa->ifa_refcnt == 0)
  282                 free(ifa, M_IFADDR);
  283         else
  284                 ifa->ifa_refcnt--;
  285 }
  286 
  287 /*
  288  * Force a routing table entry to the specified
  289  * destination to go through the given gateway.
  290  * Normally called as a result of a routing redirect
  291  * message from the network layer.
  292  *
  293  * N.B.: must be called at splnet
  294  *
  295  */
  296 void
  297 rtredirect(dst, gateway, netmask, flags, src, rtp)
  298         struct sockaddr *dst, *gateway, *netmask, *src;
  299         int flags;
  300         struct rtentry **rtp;
  301 {
  302         struct rtentry *rt;
  303         int error = 0;
  304         short *stat = 0;
  305         struct rt_addrinfo info;
  306         struct ifaddr *ifa;
  307 
  308         /* verify the gateway is directly reachable */
  309         if ((ifa = ifa_ifwithnet(gateway)) == 0) {
  310                 error = ENETUNREACH;
  311                 goto out;
  312         }
  313         rt = rtalloc1(dst, 0, 0UL);
  314         /*
  315          * If the redirect isn't from our current router for this dst,
  316          * it's either old or wrong.  If it redirects us to ourselves,
  317          * we have a routing loop, perhaps as a result of an interface
  318          * going down recently.
  319          */
  320 #define equal(a1, a2) (bcmp((caddr_t)(a1), (caddr_t)(a2), (a1)->sa_len) == 0)
  321         if (!(flags & RTF_DONE) && rt &&
  322              (!equal(src, rt->rt_gateway) || rt->rt_ifa != ifa))
  323                 error = EINVAL;
  324         else if (ifa_ifwithaddr(gateway))
  325                 error = EHOSTUNREACH;
  326         if (error)
  327                 goto done;
  328         /*
  329          * Create a new entry if we just got back a wildcard entry
  330          * or the the lookup failed.  This is necessary for hosts
  331          * which use routing redirects generated by smart gateways
  332          * to dynamically build the routing tables.
  333          */
  334         if ((rt == 0) || (rt_mask(rt) && rt_mask(rt)->sa_len < 2))
  335                 goto create;
  336         /*
  337          * Don't listen to the redirect if it's
  338          * for a route to an interface.
  339          */
  340         if (rt->rt_flags & RTF_GATEWAY) {
  341                 if (((rt->rt_flags & RTF_HOST) == 0) && (flags & RTF_HOST)) {
  342                         /*
  343                          * Changing from route to net => route to host.
  344                          * Create new route, rather than smashing route to net.
  345                          */
  346                 create:
  347                         if (rt)
  348                                 rtfree(rt);
  349                         flags |=  RTF_GATEWAY | RTF_DYNAMIC;
  350                         bzero((caddr_t)&info, sizeof(info));
  351                         info.rti_info[RTAX_DST] = dst;
  352                         info.rti_info[RTAX_GATEWAY] = gateway;
  353                         info.rti_info[RTAX_NETMASK] = netmask;
  354                         info.rti_ifa = ifa;
  355                         info.rti_flags = flags;
  356                         rt = NULL;
  357                         error = rtrequest1(RTM_ADD, &info, &rt);
  358                         if (rt != NULL)
  359                                 flags = rt->rt_flags;
  360                         stat = &rtstat.rts_dynamic;
  361                 } else {
  362                         /*
  363                          * Smash the current notion of the gateway to
  364                          * this destination.  Should check about netmask!!!
  365                          */
  366                         rt->rt_flags |= RTF_MODIFIED;
  367                         flags |= RTF_MODIFIED;
  368                         stat = &rtstat.rts_newgateway;
  369                         /*
  370                          * add the key and gateway (in one malloc'd chunk).
  371                          */
  372                         rt_setgate(rt, rt_key(rt), gateway);
  373                 }
  374         } else
  375                 error = EHOSTUNREACH;
  376 done:
  377         if (rt) {
  378                 if (rtp && !error)
  379                         *rtp = rt;
  380                 else
  381                         rtfree(rt);
  382         }
  383 out:
  384         if (error)
  385                 rtstat.rts_badredirect++;
  386         else if (stat != NULL)
  387                 (*stat)++;
  388         bzero((caddr_t)&info, sizeof(info));
  389         info.rti_info[RTAX_DST] = dst;
  390         info.rti_info[RTAX_GATEWAY] = gateway;
  391         info.rti_info[RTAX_NETMASK] = netmask;
  392         info.rti_info[RTAX_AUTHOR] = src;
  393         rt_missmsg(RTM_REDIRECT, &info, flags, error);
  394 }
  395 
  396 /*
  397 * Routing table ioctl interface.
  398 */
  399 int
  400 rtioctl(req, data)
  401         u_long req;
  402         caddr_t data;
  403 {
  404 #ifdef INET
  405         /* Multicast goop, grrr... */
  406         return mrt_ioctl ? mrt_ioctl(req, data) : EOPNOTSUPP;
  407 #else /* INET */
  408         return ENXIO;
  409 #endif /* INET */
  410 }
  411 
  412 struct ifaddr *
  413 ifa_ifwithroute(flags, dst, gateway)
  414         int flags;
  415         struct sockaddr *dst, *gateway;
  416 {
  417         register struct ifaddr *ifa;
  418         if ((flags & RTF_GATEWAY) == 0) {
  419                 /*
  420                  * If we are adding a route to an interface,
  421                  * and the interface is a pt to pt link
  422                  * we should search for the destination
  423                  * as our clue to the interface.  Otherwise
  424                  * we can use the local address.
  425                  */
  426                 ifa = 0;
  427                 if (flags & RTF_HOST) {
  428                         ifa = ifa_ifwithdstaddr(dst);
  429                 }
  430                 if (ifa == 0)
  431                         ifa = ifa_ifwithaddr(gateway);
  432         } else {
  433                 /*
  434                  * If we are adding a route to a remote net
  435                  * or host, the gateway may still be on the
  436                  * other end of a pt to pt link.
  437                  */
  438                 ifa = ifa_ifwithdstaddr(gateway);
  439         }
  440         if (ifa == 0)
  441                 ifa = ifa_ifwithnet(gateway);
  442         if (ifa == 0) {
  443                 struct rtentry *rt = rtalloc1(gateway, 0, 0UL);
  444                 if (rt == 0)
  445                         return (0);
  446                 rt->rt_refcnt--;
  447                 if ((ifa = rt->rt_ifa) == 0)
  448                         return (0);
  449         }
  450         if (ifa->ifa_addr->sa_family != dst->sa_family) {
  451                 struct ifaddr *oifa = ifa;
  452                 ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
  453                 if (ifa == 0)
  454                         ifa = oifa;
  455         }
  456         return (ifa);
  457 }
  458 
  459 static int rt_fixdelete(struct radix_node *, void *);
  460 static int rt_fixchange(struct radix_node *, void *);
  461 
  462 struct rtfc_arg {
  463         struct rtentry *rt0;
  464         struct radix_node_head *rnh;
  465 };
  466 
  467 /*
  468  * Do appropriate manipulations of a routing tree given
  469  * all the bits of info needed
  470  */
  471 int
  472 rtrequest(req, dst, gateway, netmask, flags, ret_nrt)
  473         int req, flags;
  474         struct sockaddr *dst, *gateway, *netmask;
  475         struct rtentry **ret_nrt;
  476 {
  477         struct rt_addrinfo info;
  478 
  479         bzero((caddr_t)&info, sizeof(info));
  480         info.rti_flags = flags;
  481         info.rti_info[RTAX_DST] = dst;
  482         info.rti_info[RTAX_GATEWAY] = gateway;
  483         info.rti_info[RTAX_NETMASK] = netmask;
  484         return rtrequest1(req, &info, ret_nrt);
  485 }
  486 
  487 /*
  488  * These (questionable) definitions of apparent local variables apply
  489  * to the next two functions.  XXXXXX!!!
  490  */
  491 #define dst     info->rti_info[RTAX_DST]
  492 #define gateway info->rti_info[RTAX_GATEWAY]
  493 #define netmask info->rti_info[RTAX_NETMASK]
  494 #define ifaaddr info->rti_info[RTAX_IFA]
  495 #define ifpaddr info->rti_info[RTAX_IFP]
  496 #define flags   info->rti_flags
  497 
  498 int
  499 rt_getifa(info)
  500         struct rt_addrinfo *info;
  501 {
  502         struct ifaddr *ifa;
  503         int error = 0;
  504 
  505         /*
  506          * ifp may be specified by sockaddr_dl
  507          * when protocol address is ambiguous.
  508          */
  509         if (info->rti_ifp == NULL && ifpaddr != NULL &&
  510             ifpaddr->sa_family == AF_LINK &&
  511             (ifa = ifa_ifwithnet(ifpaddr)) != NULL)
  512                 info->rti_ifp = ifa->ifa_ifp;
  513         if (info->rti_ifa == NULL && ifaaddr != NULL)
  514                 info->rti_ifa = ifa_ifwithaddr(ifaaddr);
  515         if (info->rti_ifa == NULL) {
  516                 struct sockaddr *sa;
  517 
  518                 sa = ifaaddr != NULL ? ifaaddr :
  519                     (gateway != NULL ? gateway : dst);
  520                 if (sa != NULL && info->rti_ifp != NULL)
  521                         info->rti_ifa = ifaof_ifpforaddr(sa, info->rti_ifp);
  522                 else if (dst != NULL && gateway != NULL)
  523                         info->rti_ifa = ifa_ifwithroute(flags, dst, gateway);
  524                 else if (sa != NULL)
  525                         info->rti_ifa = ifa_ifwithroute(flags, sa, sa);
  526         }
  527         if ((ifa = info->rti_ifa) != NULL) {
  528                 if (info->rti_ifp == NULL)
  529                         info->rti_ifp = ifa->ifa_ifp;
  530         } else
  531                 error = ENETUNREACH;
  532         return (error);
  533 }
  534 
  535 int
  536 rtrequest1(req, info, ret_nrt)
  537         int req;
  538         struct rt_addrinfo *info;
  539         struct rtentry **ret_nrt;
  540 {
  541         int s = splnet(); int error = 0;
  542         register struct rtentry *rt;
  543         register struct radix_node *rn;
  544         register struct radix_node_head *rnh;
  545         struct ifaddr *ifa;
  546         struct sockaddr *ndst;
  547 #define senderr(x) { error = x ; goto bad; }
  548 
  549         /*
  550          * Find the correct routing tree to use for this Address Family
  551          */
  552         if ((rnh = rt_tables[dst->sa_family]) == 0)
  553                 senderr(EAFNOSUPPORT);
  554         /*
  555          * If we are adding a host route then we don't want to put
  556          * a netmask in the tree, nor do we want to clone it.
  557          */
  558         if (flags & RTF_HOST) {
  559                 netmask = 0;
  560                 flags &= ~(RTF_CLONING | RTF_PRCLONING);
  561         }
  562         switch (req) {
  563         case RTM_DELETE:
  564                 /*
  565                  * Remove the item from the tree and return it.
  566                  * Complain if it is not there and do no more processing.
  567                  */
  568                 if ((rn = rnh->rnh_deladdr(dst, netmask, rnh)) == 0)
  569                         senderr(ESRCH);
  570                 if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT))
  571                         panic ("rtrequest delete");
  572                 rt = (struct rtentry *)rn;
  573 
  574                 /*
  575                  * Now search what's left of the subtree for any cloned
  576                  * routes which might have been formed from this node.
  577                  */
  578                 if ((rt->rt_flags & (RTF_CLONING | RTF_PRCLONING)) &&
  579                     rt_mask(rt)) {
  580                         rnh->rnh_walktree_from(rnh, dst, rt_mask(rt),
  581                                                rt_fixdelete, rt);
  582                 }
  583 
  584                 /*
  585                  * Remove any external references we may have.
  586                  * This might result in another rtentry being freed if
  587                  * we held its last reference.
  588                  */
  589                 if (rt->rt_gwroute) {
  590                         rt = rt->rt_gwroute;
  591                         RTFREE(rt);
  592                         (rt = (struct rtentry *)rn)->rt_gwroute = 0;
  593                 }
  594 
  595                 /*
  596                  * NB: RTF_UP must be set during the search above,
  597                  * because we might delete the last ref, causing
  598                  * rt to get freed prematurely.
  599                  *  eh? then why not just add a reference?
  600                  * I'm not sure how RTF_UP helps matters. (JRE)
  601                  */
  602                 rt->rt_flags &= ~RTF_UP;
  603 
  604                 /*
  605                  * give the protocol a chance to keep things in sync.
  606                  */
  607                 if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest)
  608                         ifa->ifa_rtrequest(RTM_DELETE, rt, info);
  609 
  610                 /*
  611                  * one more rtentry floating around that is not
  612                  * linked to the routing table.
  613                  */
  614                 rttrash++;
  615 
  616                 /*
  617                  * If the caller wants it, then it can have it,
  618                  * but it's up to it to free the rtentry as we won't be
  619                  * doing it.
  620                  */
  621                 if (ret_nrt)
  622                         *ret_nrt = rt;
  623                 else if (rt->rt_refcnt <= 0) {
  624                         rt->rt_refcnt++; /* make a 1->0 transition */
  625                         rtfree(rt);
  626                 }
  627                 break;
  628 
  629         case RTM_RESOLVE:
  630                 if (ret_nrt == 0 || (rt = *ret_nrt) == 0)
  631                         senderr(EINVAL);
  632                 ifa = rt->rt_ifa;
  633                 flags = rt->rt_flags &
  634                     ~(RTF_CLONING | RTF_PRCLONING | RTF_STATIC);
  635                 flags |= RTF_WASCLONED;
  636                 gateway = rt->rt_gateway;
  637                 if ((netmask = rt->rt_genmask) == 0)
  638                         flags |= RTF_HOST;
  639                 goto makeroute;
  640 
  641         case RTM_ADD:
  642                 if ((flags & RTF_GATEWAY) && !gateway)
  643                         panic("rtrequest: GATEWAY but no gateway");
  644 
  645                 if (info->rti_ifa == NULL && (error = rt_getifa(info)))
  646                         senderr(error);
  647                 ifa = info->rti_ifa;
  648 
  649         makeroute:
  650                 R_Malloc(rt, struct rtentry *, sizeof(*rt));
  651                 if (rt == 0)
  652                         senderr(ENOBUFS);
  653                 Bzero(rt, sizeof(*rt));
  654                 rt->rt_flags = RTF_UP | flags;
  655                 /*
  656                  * Add the gateway. Possibly re-malloc-ing the storage for it
  657                  * also add the rt_gwroute if possible.
  658                  */
  659                 if ((error = rt_setgate(rt, dst, gateway)) != 0) {
  660                         Free(rt);
  661                         senderr(error);
  662                 }
  663 
  664                 /*
  665                  * point to the (possibly newly malloc'd) dest address.
  666                  */
  667                 ndst = rt_key(rt);
  668 
  669                 /*
  670                  * make sure it contains the value we want (masked if needed).
  671                  */
  672                 if (netmask) {
  673                         rt_maskedcopy(dst, ndst, netmask);
  674                 } else
  675                         Bcopy(dst, ndst, dst->sa_len);
  676 
  677                 /*
  678                  * Note that we now have a reference to the ifa.
  679                  * This moved from below so that rnh->rnh_addaddr() can
  680                  * examine the ifa and  ifa->ifa_ifp if it so desires.
  681                  */
  682                 ifa->ifa_refcnt++;
  683                 rt->rt_ifa = ifa;
  684                 rt->rt_ifp = ifa->ifa_ifp;
  685                 /* XXX mtu manipulation will be done in rnh_addaddr -- itojun */
  686 
  687                 rn = rnh->rnh_addaddr((caddr_t)ndst, (caddr_t)netmask,
  688                                         rnh, rt->rt_nodes);
  689                 if (rn == 0) {
  690                         struct rtentry *rt2;
  691                         /*
  692                          * Uh-oh, we already have one of these in the tree.
  693                          * We do a special hack: if the route that's already
  694                          * there was generated by the protocol-cloning
  695                          * mechanism, then we just blow it away and retry
  696                          * the insertion of the new one.
  697                          */
  698                         rt2 = rtalloc1(dst, 0, RTF_PRCLONING);
  699                         if (rt2 && rt2->rt_parent) {
  700                                 rtrequest(RTM_DELETE,
  701                                           (struct sockaddr *)rt_key(rt2),
  702                                           rt2->rt_gateway,
  703                                           rt_mask(rt2), rt2->rt_flags, 0);
  704                                 RTFREE(rt2);
  705                                 rn = rnh->rnh_addaddr((caddr_t)ndst,
  706                                                       (caddr_t)netmask,
  707                                                       rnh, rt->rt_nodes);
  708                         } else if (rt2) {
  709                                 /* undo the extra ref we got */
  710                                 RTFREE(rt2);
  711                         }
  712                 }
  713 
  714                 /*
  715                  * If it still failed to go into the tree,
  716                  * then un-make it (this should be a function)
  717                  */
  718                 if (rn == 0) {
  719                         if (rt->rt_gwroute)
  720                                 rtfree(rt->rt_gwroute);
  721                         if (rt->rt_ifa) {
  722                                 IFAFREE(rt->rt_ifa);
  723                         }
  724                         Free(rt_key(rt));
  725                         Free(rt);
  726                         senderr(EEXIST);
  727                 }
  728 
  729                 rt->rt_parent = 0;
  730 
  731                 /*
  732                  * If we got here from RESOLVE, then we are cloning
  733                  * so clone the rest, and note that we
  734                  * are a clone (and increment the parent's references)
  735                  */
  736                 if (req == RTM_RESOLVE) {
  737                         rt->rt_rmx = (*ret_nrt)->rt_rmx; /* copy metrics */
  738                         rt->rt_rmx.rmx_pksent = 0; /* reset packet counter */
  739                         if ((*ret_nrt)->rt_flags & (RTF_CLONING | RTF_PRCLONING)) {
  740                                 rt->rt_parent = (*ret_nrt);
  741                                 (*ret_nrt)->rt_refcnt++;
  742                         }
  743                 }
  744 
  745                 /*
  746                  * if this protocol has something to add to this then
  747                  * allow it to do that as well.
  748                  */
  749                 if (ifa->ifa_rtrequest)
  750                         ifa->ifa_rtrequest(req, rt, info);
  751 
  752                 /*
  753                  * We repeat the same procedure from rt_setgate() here because
  754                  * it doesn't fire when we call it there because the node
  755                  * hasn't been added to the tree yet.
  756                  */
  757                 if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != 0) {
  758                         struct rtfc_arg arg;
  759                         arg.rnh = rnh;
  760                         arg.rt0 = rt;
  761                         rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt),
  762                                                rt_fixchange, &arg);
  763                 }
  764 
  765                 /*
  766                  * actually return a resultant rtentry and
  767                  * give the caller a single reference.
  768                  */
  769                 if (ret_nrt) {
  770                         *ret_nrt = rt;
  771                         rt->rt_refcnt++;
  772                 }
  773                 break;
  774         default:
  775                 error = EOPNOTSUPP;
  776         }
  777 bad:
  778         splx(s);
  779         return (error);
  780 #undef dst
  781 #undef gateway
  782 #undef netmask
  783 #undef ifaaddr
  784 #undef ifpaddr
  785 #undef flags
  786 }
  787 
  788 /*
  789  * Called from rtrequest(RTM_DELETE, ...) to fix up the route's ``family''
  790  * (i.e., the routes related to it by the operation of cloning).  This
  791  * routine is iterated over all potential former-child-routes by way of
  792  * rnh->rnh_walktree_from() above, and those that actually are children of
  793  * the late parent (passed in as VP here) are themselves deleted.
  794  */
  795 static int
  796 rt_fixdelete(rn, vp)
  797         struct radix_node *rn;
  798         void *vp;
  799 {
  800         struct rtentry *rt = (struct rtentry *)rn;
  801         struct rtentry *rt0 = vp;
  802 
  803         if (rt->rt_parent == rt0 && !(rt->rt_flags & RTF_PINNED)) {
  804                 return rtrequest(RTM_DELETE, rt_key(rt),
  805                                  (struct sockaddr *)0, rt_mask(rt),
  806                                  rt->rt_flags, (struct rtentry **)0);
  807         }
  808         return 0;
  809 }
  810 
  811 /*
  812  * This routine is called from rt_setgate() to do the analogous thing for
  813  * adds and changes.  There is the added complication in this case of a
  814  * middle insert; i.e., insertion of a new network route between an older
  815  * network route and (cloned) host routes.  For this reason, a simple check
  816  * of rt->rt_parent is insufficient; each candidate route must be tested
  817  * against the (mask, value) of the new route (passed as before in vp)
  818  * to see if the new route matches it.
  819  *
  820  * XXX - it may be possible to do fixdelete() for changes and reserve this
  821  * routine just for adds.  I'm not sure why I thought it was necessary to do
  822  * changes this way.
  823  */
  824 #ifdef DEBUG
  825 static int rtfcdebug = 0;
  826 #endif
  827 
  828 static int
  829 rt_fixchange(rn, vp)
  830         struct radix_node *rn;
  831         void *vp;
  832 {
  833         struct rtentry *rt = (struct rtentry *)rn;
  834         struct rtfc_arg *ap = vp;
  835         struct rtentry *rt0 = ap->rt0;
  836         struct radix_node_head *rnh = ap->rnh;
  837         u_char *xk1, *xm1, *xk2, *xmp;
  838         int i, len, mlen;
  839 
  840 #ifdef DEBUG
  841         if (rtfcdebug)
  842                 printf("rt_fixchange: rt %p, rt0 %p\n", rt, rt0);
  843 #endif
  844 
  845         if (!rt->rt_parent || (rt->rt_flags & RTF_PINNED)) {
  846 #ifdef DEBUG
  847                 if(rtfcdebug) printf("no parent or pinned\n");
  848 #endif
  849                 return 0;
  850         }
  851 
  852         if (rt->rt_parent == rt0) {
  853 #ifdef DEBUG
  854                 if(rtfcdebug) printf("parent match\n");
  855 #endif
  856                 return rtrequest(RTM_DELETE, rt_key(rt),
  857                                  (struct sockaddr *)0, rt_mask(rt),
  858                                  rt->rt_flags, (struct rtentry **)0);
  859         }
  860 
  861         /*
  862          * There probably is a function somewhere which does this...
  863          * if not, there should be.
  864          */
  865         len = imin(((struct sockaddr *)rt_key(rt0))->sa_len,
  866                    ((struct sockaddr *)rt_key(rt))->sa_len);
  867 
  868         xk1 = (u_char *)rt_key(rt0);
  869         xm1 = (u_char *)rt_mask(rt0);
  870         xk2 = (u_char *)rt_key(rt);
  871 
  872         /* avoid applying a less specific route */
  873         xmp = (u_char *)rt_mask(rt->rt_parent);
  874         mlen = ((struct sockaddr *)rt_key(rt->rt_parent))->sa_len;
  875         if (mlen > ((struct sockaddr *)rt_key(rt0))->sa_len) {
  876 #ifdef DEBUG
  877                 if (rtfcdebug)
  878                         printf("rt_fixchange: inserting a less "
  879                                "specific route\n");
  880 #endif
  881                 return 0;
  882         }
  883         for (i = rnh->rnh_treetop->rn_offset; i < mlen; i++) {
  884                 if ((xmp[i] & ~(xmp[i] ^ xm1[i])) != xmp[i]) {
  885 #ifdef DEBUG
  886                         if (rtfcdebug)
  887                                 printf("rt_fixchange: inserting a less "
  888                                        "specific route\n");
  889 #endif
  890                         return 0;
  891                 }
  892         }
  893 
  894         for (i = rnh->rnh_treetop->rn_offset; i < len; i++) {
  895                 if ((xk2[i] & xm1[i]) != xk1[i]) {
  896 #ifdef DEBUG
  897                         if(rtfcdebug) printf("no match\n");
  898 #endif
  899                         return 0;
  900                 }
  901         }
  902 
  903         /*
  904          * OK, this node is a clone, and matches the node currently being
  905          * changed/added under the node's mask.  So, get rid of it.
  906          */
  907 #ifdef DEBUG
  908         if(rtfcdebug) printf("deleting\n");
  909 #endif
  910         return rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0,
  911                          rt_mask(rt), rt->rt_flags, (struct rtentry **)0);
  912 }
  913 
  914 #define ROUNDUP(a) (a>0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
  915 
  916 int
  917 rt_setgate(rt0, dst, gate)
  918         struct rtentry *rt0;
  919         struct sockaddr *dst, *gate;
  920 {
  921         caddr_t new, old;
  922         int dlen = ROUNDUP(dst->sa_len), glen = ROUNDUP(gate->sa_len);
  923         register struct rtentry *rt = rt0;
  924         struct radix_node_head *rnh = rt_tables[dst->sa_family];
  925 
  926         /*
  927          * A host route with the destination equal to the gateway
  928          * will interfere with keeping LLINFO in the routing
  929          * table, so disallow it.
  930          */
  931         if (((rt0->rt_flags & (RTF_HOST|RTF_GATEWAY|RTF_LLINFO)) ==
  932                                         (RTF_HOST|RTF_GATEWAY)) &&
  933             (dst->sa_len == gate->sa_len) &&
  934             (bcmp(dst, gate, dst->sa_len) == 0)) {
  935                 /*
  936                  * The route might already exist if this is an RTM_CHANGE
  937                  * or a routing redirect, so try to delete it.
  938                  */
  939                 if (rt_key(rt0))
  940                         rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt0),
  941                             rt0->rt_gateway, rt_mask(rt0), rt0->rt_flags, 0);
  942                 return EADDRNOTAVAIL;
  943         }
  944 
  945         /*
  946          * Both dst and gateway are stored in the same malloc'd chunk
  947          * (If I ever get my hands on....)
  948          * if we need to malloc a new chunk, then keep the old one around
  949          * till we don't need it any more.
  950          */
  951         if (rt->rt_gateway == 0 || glen > ROUNDUP(rt->rt_gateway->sa_len)) {
  952                 old = (caddr_t)rt_key(rt);
  953                 R_Malloc(new, caddr_t, dlen + glen);
  954                 if (new == 0)
  955                         return ENOBUFS;
  956                 rt->rt_nodes->rn_key = new;
  957         } else {
  958                 /*
  959                  * otherwise just overwrite the old one
  960                  */
  961                 new = rt->rt_nodes->rn_key;
  962                 old = 0;
  963         }
  964 
  965         /*
  966          * copy the new gateway value into the memory chunk
  967          */
  968         Bcopy(gate, (rt->rt_gateway = (struct sockaddr *)(new + dlen)), glen);
  969 
  970         /*
  971          * if we are replacing the chunk (or it's new) we need to
  972          * replace the dst as well
  973          */
  974         if (old) {
  975                 Bcopy(dst, new, dlen);
  976                 Free(old);
  977         }
  978 
  979         /*
  980          * If there is already a gwroute, it's now almost definitly wrong
  981          * so drop it.
  982          */
  983         if (rt->rt_gwroute != NULL) {
  984                 RTFREE(rt->rt_gwroute);
  985                 rt->rt_gwroute = NULL;
  986         }
  987         /*
  988          * Cloning loop avoidance:
  989          * In the presence of protocol-cloning and bad configuration,
  990          * it is possible to get stuck in bottomless mutual recursion
  991          * (rtrequest rt_setgate rtalloc1).  We avoid this by not allowing
  992          * protocol-cloning to operate for gateways (which is probably the
  993          * correct choice anyway), and avoid the resulting reference loops
  994          * by disallowing any route to run through itself as a gateway.
  995          * This is obviously mandatory when we get rt->rt_output().
  996          */
  997         if (rt->rt_flags & RTF_GATEWAY) {
  998                 rt->rt_gwroute = rtalloc1(gate, 1, RTF_PRCLONING);
  999                 if (rt->rt_gwroute == rt) {
 1000                         RTFREE(rt->rt_gwroute);
 1001                         rt->rt_gwroute = 0;
 1002                         return EDQUOT; /* failure */
 1003                 }
 1004         }
 1005 
 1006         /*
 1007          * This isn't going to do anything useful for host routes, so
 1008          * don't bother.  Also make sure we have a reasonable mask
 1009          * (we don't yet have one during adds).
 1010          */
 1011         if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != 0) {
 1012                 struct rtfc_arg arg;
 1013                 arg.rnh = rnh;
 1014                 arg.rt0 = rt;
 1015                 rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt),
 1016                                        rt_fixchange, &arg);
 1017         }
 1018 
 1019         return 0;
 1020 }
 1021 
 1022 static void
 1023 rt_maskedcopy(src, dst, netmask)
 1024         struct sockaddr *src, *dst, *netmask;
 1025 {
 1026         register u_char *cp1 = (u_char *)src;
 1027         register u_char *cp2 = (u_char *)dst;
 1028         register u_char *cp3 = (u_char *)netmask;
 1029         u_char *cplim = cp2 + *cp3;
 1030         u_char *cplim2 = cp2 + *cp1;
 1031 
 1032         *cp2++ = *cp1++; *cp2++ = *cp1++; /* copies sa_len & sa_family */
 1033         cp3 += 2;
 1034         if (cplim > cplim2)
 1035                 cplim = cplim2;
 1036         while (cp2 < cplim)
 1037                 *cp2++ = *cp1++ & *cp3++;
 1038         if (cp2 < cplim2)
 1039                 bzero((caddr_t)cp2, (unsigned)(cplim2 - cp2));
 1040 }
 1041 
 1042 /*
 1043  * Set up a routing table entry, normally
 1044  * for an interface.
 1045  */
 1046 int
 1047 rtinit(ifa, cmd, flags)
 1048         register struct ifaddr *ifa;
 1049         int cmd, flags;
 1050 {
 1051         register struct rtentry *rt;
 1052         register struct sockaddr *dst;
 1053         register struct sockaddr *deldst;
 1054         struct sockaddr *netmask;
 1055         struct mbuf *m = 0;
 1056         struct rtentry *nrt = 0;
 1057         struct radix_node_head *rnh;
 1058         struct radix_node *rn;
 1059         int error;
 1060         struct rt_addrinfo info;
 1061 
 1062         if (flags & RTF_HOST) {
 1063                 dst = ifa->ifa_dstaddr;
 1064                 netmask = NULL;
 1065         } else {
 1066                 dst = ifa->ifa_addr;
 1067                 netmask = ifa->ifa_netmask;
 1068         }
 1069         /*
 1070          * If it's a delete, check that if it exists, it's on the correct
 1071          * interface or we might scrub a route to another ifa which would
 1072          * be confusing at best and possibly worse.
 1073          */
 1074         if (cmd == RTM_DELETE) {
 1075                 /*
 1076                  * It's a delete, so it should already exist..
 1077                  * If it's a net, mask off the host bits
 1078                  * (Assuming we have a mask)
 1079                  */
 1080                 if (netmask != NULL) {
 1081                         m = m_get(M_DONTWAIT, MT_SONAME);
 1082                         if (m == NULL)
 1083                                 return(ENOBUFS);
 1084                         deldst = mtod(m, struct sockaddr *);
 1085                         rt_maskedcopy(dst, deldst, netmask);
 1086                         dst = deldst;
 1087                 }
 1088                 /*
 1089                  * Look up an rtentry that is in the routing tree and
 1090                  * contains the correct info.
 1091                  */
 1092                 if ((rnh = rt_tables[dst->sa_family]) == NULL ||
 1093                     (rn = rnh->rnh_lookup(dst, netmask, rnh)) == NULL ||
 1094                     (rn->rn_flags & RNF_ROOT) ||
 1095                     ((struct rtentry *)rn)->rt_ifa != ifa ||
 1096                     !equal(SA(rn->rn_key), dst)) {
 1097                         if (m)
 1098                                 (void) m_free(m);
 1099                         return (flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
 1100                 }
 1101                 /* XXX */
 1102 #if 0
 1103                 else {
 1104                         /*
 1105                          * One would think that as we are deleting, and we know
 1106                          * it doesn't exist, we could just return at this point
 1107                          * with an "ELSE" clause, but apparently not..
 1108                          */
 1109                         return (flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
 1110                 }
 1111 #endif
 1112         }
 1113         /*
 1114          * Do the actual request
 1115          */
 1116         bzero((caddr_t)&info, sizeof(info));
 1117         info.rti_ifa = ifa;
 1118         info.rti_flags = flags | ifa->ifa_flags;
 1119         info.rti_info[RTAX_DST] = dst;
 1120         info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr;
 1121         info.rti_info[RTAX_NETMASK] = netmask;
 1122         error = rtrequest1(cmd, &info, &nrt);
 1123         if (error == 0 && (rt = nrt) != NULL) {
 1124                 /*
 1125                  * notify any listening routing agents of the change
 1126                  */
 1127                 rt_newaddrmsg(cmd, ifa, error, rt);
 1128                 if (cmd == RTM_DELETE) {
 1129                         /*
 1130                          * If we are deleting, and we found an entry, then
 1131                          * it's been removed from the tree.. now throw it away.
 1132                          */
 1133                         if (rt->rt_refcnt <= 0) {
 1134                                 rt->rt_refcnt++; /* make a 1->0 transition */
 1135                                 rtfree(rt);
 1136                         }
 1137                 } else if (cmd == RTM_ADD) {
 1138                         /*
 1139                          * We just wanted to add it.. we don't actually
 1140                          * need a reference.
 1141                          */
 1142                         rt->rt_refcnt--;
 1143                 }
 1144         }
 1145         if (m)
 1146                 (void) m_free(m);
 1147         return (error);
 1148 }
 1149 
 1150 /* This must be before ip6_init2(), which is now SI_ORDER_MIDDLE */
 1151 SYSINIT(route, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, route_init, 0);

Cache object: 2b1c33e2a65ee599cc95a7ecb4a6f826


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