Annotation of XNU/bsd/net/route.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
                      3:  *
                      4:  * @APPLE_LICENSE_HEADER_START@
                      5:  * 
                      6:  * The contents of this file constitute Original Code as defined in and
                      7:  * are subject to the Apple Public Source License Version 1.1 (the
                      8:  * "License").  You may not use this file except in compliance with the
                      9:  * License.  Please obtain a copy of the License at
                     10:  * http://www.apple.com/publicsource and read it before using this file.
                     11:  * 
                     12:  * This Original Code and all software distributed under the License are
                     13:  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
                     14:  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
                     15:  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
                     16:  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
                     17:  * License for the specific language governing rights and limitations
                     18:  * under the License.
                     19:  * 
                     20:  * @APPLE_LICENSE_HEADER_END@
                     21:  */
                     22: /*
                     23:  * Copyright (c) 1980, 1986, 1991, 1993
                     24:  *     The Regents of the University of California.  All rights reserved.
                     25:  *
                     26:  * Redistribution and use in source and binary forms, with or without
                     27:  * modification, are permitted provided that the following conditions
                     28:  * are met:
                     29:  * 1. Redistributions of source code must retain the above copyright
                     30:  *    notice, this list of conditions and the following disclaimer.
                     31:  * 2. Redistributions in binary form must reproduce the above copyright
                     32:  *    notice, this list of conditions and the following disclaimer in the
                     33:  *    documentation and/or other materials provided with the distribution.
                     34:  * 3. All advertising materials mentioning features or use of this software
                     35:  *    must display the following acknowledgement:
                     36:  *     This product includes software developed by the University of
                     37:  *     California, Berkeley and its contributors.
                     38:  * 4. Neither the name of the University nor the names of its contributors
                     39:  *    may be used to endorse or promote products derived from this software
                     40:  *    without specific prior written permission.
                     41:  *
                     42:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     43:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     44:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     45:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     46:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     47:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     48:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     49:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     50:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     51:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     52:  * SUCH DAMAGE.
                     53:  *
                     54:  *     @(#)route.c     8.2 (Berkeley) 11/15/93
                     55:  */
                     56: 
                     57: #if NOTFB31
                     58: #include "opt_inet.h"
                     59: #include "opt_mrouting.h"
                     60: #endif
                     61: 
                     62: #include <sys/param.h>
                     63: #include <sys/systm.h>
                     64: #include <sys/malloc.h>
                     65: #include <sys/mbuf.h>
                     66: #include <sys/socket.h>
                     67: #include <sys/domain.h>
                     68: 
                     69: #include <net/if.h>
                     70: #include <net/route.h>
                     71: 
                     72: #include <netinet/in.h>
                     73: #include <netinet/ip_mroute.h>
                     74: 
                     75: #define        SA(p) ((struct sockaddr *)(p))
                     76: 
                     77: struct route_cb route_cb;
                     78: static struct rtstat rtstat;
                     79: struct radix_node_head *rt_tables[AF_MAX+1];
                     80: 
                     81: static int     rttrash;                /* routes not in table but not freed */
                     82: 
                     83: static void rt_maskedcopy __P((struct sockaddr *,
                     84:            struct sockaddr *, struct sockaddr *));
                     85: static void rtable_init __P((void **));
                     86: 
                     87: static void
                     88: rtable_init(table)
                     89:        void **table;
                     90: {
                     91:        struct domain *dom;
                     92:        for (dom = domains; dom; dom = dom->dom_next)
                     93:                if (dom->dom_rtattach)
                     94:                        dom->dom_rtattach(&table[dom->dom_family],
                     95:                            dom->dom_rtoffset);
                     96: }
                     97: 
                     98: void
                     99: route_init()
                    100: {
                    101:        rn_init();      /* initialize all zeroes, all ones, mask table */
                    102:        rtable_init((void **)rt_tables);
                    103: }
                    104: 
                    105: /*
                    106:  * Packet routing routines.
                    107:  */
                    108: void
                    109: rtalloc(ro)
                    110:        register struct route *ro;
                    111: {
                    112:        if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP))
                    113:                return;                          /* XXX */
                    114:        ro->ro_rt = rtalloc1(&ro->ro_dst, 1, 0UL);
                    115: }
                    116: 
                    117: void
                    118: rtalloc_ign(ro, ignore)
                    119:        register struct route *ro;
                    120:        u_long ignore;
                    121: {
                    122:        if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP))
                    123:                return;                          /* XXX */
                    124:        ro->ro_rt = rtalloc1(&ro->ro_dst, 1, ignore);
                    125: }
                    126: 
                    127: /*
                    128:  * Look up the route that matches the address given
                    129:  * Or, at least try.. Create a cloned route if needed.
                    130:  */
                    131: struct rtentry *
                    132: rtalloc1(dst, report, ignflags)
                    133:        register struct sockaddr *dst;
                    134:        int report;
                    135:        u_long ignflags;
                    136: {
                    137:        register struct radix_node_head *rnh = rt_tables[dst->sa_family];
                    138:        register struct rtentry *rt;
                    139:        register struct radix_node *rn;
                    140:        struct rtentry *newrt = 0;
                    141:        struct rt_addrinfo info;
                    142:        u_long nflags;
                    143:        int  s = splnet(), err = 0, msgtype = RTM_MISS;
                    144: 
                    145:        /* 
                    146:         * Look up the address in the table for that Address Family
                    147:         */
                    148:        if (rnh && (rn = rnh->rnh_matchaddr((caddr_t)dst, rnh)) &&
                    149:            ((rn->rn_flags & RNF_ROOT) == 0)) {
                    150:                /*
                    151:                 * If we find it and it's not the root node, then
                    152:                 * get a refernce on the rtentry associated.
                    153:                 */
                    154:                newrt = rt = (struct rtentry *)rn;
                    155:                nflags = rt->rt_flags & ~ignflags;
                    156:                if (report && (nflags & (RTF_CLONING | RTF_PRCLONING))) {
                    157:                        /*
                    158:                         * We are apparently adding (report = 0 in delete).
                    159:                         * If it requires that it be cloned, do so.
                    160:                         * (This implies it wasn't a HOST route.)
                    161:                         */
                    162:                        err = rtrequest(RTM_RESOLVE, dst, SA(0),
                    163:                                              SA(0), 0, &newrt);
                    164:                        if (err) {
                    165:                                /*
                    166:                                 * If the cloning didn't succeed, maybe
                    167:                                 * what we have will do. Return that.
                    168:                                 */
                    169:                                newrt = rt;
                    170:                                rt->rt_refcnt++;
                    171:                                goto miss;
                    172:                        }
                    173:                        if ((rt = newrt) && (rt->rt_flags & RTF_XRESOLVE)) {
                    174:                                /*
                    175:                                 * If the new route specifies it be 
                    176:                                 * externally resolved, then go do that.
                    177:                                 */
                    178:                                msgtype = RTM_RESOLVE;
                    179:                                goto miss;
                    180:                        }
                    181:                } else
                    182:                        rt->rt_refcnt++;
                    183:        } else {
                    184:                /*
                    185:                 * Either we hit the root or couldn't find any match,
                    186:                 * Which basically means
                    187:                 * "caint get there frm here"
                    188:                 */
                    189:                rtstat.rts_unreach++;
                    190:        miss:   if (report) {
                    191:                        /*
                    192:                         * If required, report the failure to the supervising
                    193:                         * Authorities.
                    194:                         * For a delete, this is not an error. (report == 0)
                    195:                         */
                    196:                        bzero((caddr_t)&info, sizeof(info));
                    197:                        info.rti_info[RTAX_DST] = dst;
                    198:                        rt_missmsg(msgtype, &info, 0, err);
                    199:                }
                    200:        }
                    201:        splx(s);
                    202:        return (newrt);
                    203: }
                    204: 
                    205: /*
                    206:  * Remove a reference count from an rtentry.
                    207:  * If the count gets low enough, take it out of the routing table
                    208:  */
                    209: void
                    210: rtfree(rt)
                    211:        register struct rtentry *rt;
                    212: {
                    213:        /*
                    214:         * find the tree for that address family
                    215:         */
                    216:        register struct radix_node_head *rnh =
                    217:                rt_tables[rt_key(rt)->sa_family];
                    218:        register struct ifaddr *ifa;
                    219: 
                    220:        if (rt == 0 || rnh == 0)
                    221:                panic("rtfree");
                    222: 
                    223:        /*
                    224:         * decrement the reference count by one and if it reaches 0,
                    225:         * and there is a close function defined, call the close function
                    226:         */
                    227:        rt->rt_refcnt--;
                    228:        if(rnh->rnh_close && rt->rt_refcnt == 0) {
                    229:                rnh->rnh_close((struct radix_node *)rt, rnh);
                    230:        }
                    231: 
                    232:        /*
                    233:         * If we are no longer "up" (and ref == 0)
                    234:         * then we can free the resources associated
                    235:         * with the route.
                    236:         */
                    237:        if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_UP) == 0) {
                    238:                if (rt->rt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT))
                    239:                        panic ("rtfree 2");
                    240:                /* 
                    241:                 * the rtentry must have been removed from the routing table
                    242:                 * so it is represented in rttrash.. remove that now.
                    243:                 */
                    244:                rttrash--;
                    245: 
                    246: #ifdef DIAGNOSTIC
                    247:                if (rt->rt_refcnt < 0) {
                    248:                        printf("rtfree: %p not freed (neg refs)\n", rt);
                    249:                        return;
                    250:                }
                    251: #endif
                    252: 
                    253:                /* 
                    254:                 * release references on items we hold them on..
                    255:                 * e.g other routes and ifaddrs.
                    256:                 */
                    257:                if((ifa = rt->rt_ifa))
                    258:                        IFAFREE(ifa);
                    259:                if (rt->rt_parent) {
                    260:                        RTFREE(rt->rt_parent);
                    261:                }
                    262: 
                    263:                /*
                    264:                 * The key is separatly alloc'd so free it (see rt_setgate()).
                    265:                 * This also frees the gateway, as they are always malloc'd
                    266:                 * together.
                    267:                 */
                    268:                Free(rt_key(rt));
                    269: 
                    270:                /*
                    271:                 * and the rtentry itself of course
                    272:                 */
                    273:                Free(rt);
                    274:        }
                    275: }
                    276: 
                    277: void
                    278: ifafree(ifa)
                    279:        register struct ifaddr *ifa;
                    280: {
                    281:        if (ifa == NULL)
                    282:                panic("ifafree");
                    283:        if (ifa->ifa_refcnt == 0)
                    284:                FREE(ifa, M_IFADDR);
                    285:        else
                    286:                ifa->ifa_refcnt--;
                    287: }
                    288: 
                    289: /*
                    290:  * Force a routing table entry to the specified
                    291:  * destination to go through the given gateway.
                    292:  * Normally called as a result of a routing redirect
                    293:  * message from the network layer.
                    294:  *
                    295:  * N.B.: must be called at splnet
                    296:  *
                    297:  */
                    298: void
                    299: rtredirect(dst, gateway, netmask, flags, src, rtp)
                    300:        struct sockaddr *dst, *gateway, *netmask, *src;
                    301:        int flags;
                    302:        struct rtentry **rtp;
                    303: {
                    304:        register struct rtentry *rt;
                    305:        int error = 0;
                    306:        short *stat = 0;
                    307:        struct rt_addrinfo info;
                    308:        struct ifaddr *ifa;
                    309: 
                    310:        /* verify the gateway is directly reachable */
                    311:        if ((ifa = ifa_ifwithnet(gateway)) == 0) {
                    312:                error = ENETUNREACH;
                    313:                goto out;
                    314:        }
                    315:        rt = rtalloc1(dst, 0, 0UL);
                    316:        /*
                    317:         * If the redirect isn't from our current router for this dst,
                    318:         * it's either old or wrong.  If it redirects us to ourselves,
                    319:         * we have a routing loop, perhaps as a result of an interface
                    320:         * going down recently.
                    321:         */
                    322: #define        equal(a1, a2) (bcmp((caddr_t)(a1), (caddr_t)(a2), (a1)->sa_len) == 0)
                    323:        if (!(flags & RTF_DONE) && rt &&
                    324:             (!equal(src, rt->rt_gateway) || rt->rt_ifa != ifa))
                    325:                error = EINVAL;
                    326:        else if (ifa_ifwithaddr(gateway))
                    327:                error = EHOSTUNREACH;
                    328:        if (error)
                    329:                goto done;
                    330:        /*
                    331:         * Create a new entry if we just got back a wildcard entry
                    332:         * or the the lookup failed.  This is necessary for hosts
                    333:         * which use routing redirects generated by smart gateways
                    334:         * to dynamically build the routing tables.
                    335:         */
                    336:        if ((rt == 0) || (rt_mask(rt) && rt_mask(rt)->sa_len < 2))
                    337:                goto create;
                    338:        /*
                    339:         * Don't listen to the redirect if it's
                    340:         * for a route to an interface.
                    341:         */
                    342:        if (rt->rt_flags & RTF_GATEWAY) {
                    343:                if (((rt->rt_flags & RTF_HOST) == 0) && (flags & RTF_HOST)) {
                    344:                        /*
                    345:                         * Changing from route to net => route to host.
                    346:                         * Create new route, rather than smashing route to net.
                    347:                         */
                    348:                create:
                    349:                        flags |=  RTF_GATEWAY | RTF_DYNAMIC;
                    350:                        error = rtrequest((int)RTM_ADD, dst, gateway,
                    351:                                    netmask, flags,
                    352:                                    (struct rtentry **)0);
                    353:                        stat = &rtstat.rts_dynamic;
                    354:                } else {
                    355:                        /*
                    356:                         * Smash the current notion of the gateway to
                    357:                         * this destination.  Should check about netmask!!!
                    358:                         */
                    359:                        rt->rt_flags |= RTF_MODIFIED;
                    360:                        flags |= RTF_MODIFIED;
                    361:                        stat = &rtstat.rts_newgateway;
                    362:                        /*
                    363:                         * add the key and gateway (in one malloc'd chunk).
                    364:                         */
                    365:                        rt_setgate(rt, rt_key(rt), gateway);
                    366:                }
                    367:        } else
                    368:                error = EHOSTUNREACH;
                    369: done:
                    370:        if (rt) {
                    371:                if (rtp && !error)
                    372:                        *rtp = rt;
                    373:                else
                    374:                        rtfree(rt);
                    375:        }
                    376: out:
                    377:        if (error)
                    378:                rtstat.rts_badredirect++;
                    379:        else if (stat != NULL)
                    380:                (*stat)++;
                    381:        bzero((caddr_t)&info, sizeof(info));
                    382:        info.rti_info[RTAX_DST] = dst;
                    383:        info.rti_info[RTAX_GATEWAY] = gateway;
                    384:        info.rti_info[RTAX_NETMASK] = netmask;
                    385:        info.rti_info[RTAX_AUTHOR] = src;
                    386:        rt_missmsg(RTM_REDIRECT, &info, flags, error);
                    387: }
                    388: 
                    389: /*
                    390: * Routing table ioctl interface.
                    391: */
                    392: int
                    393: rtioctl(req, data, p)
                    394:        int req;
                    395:        caddr_t data;
                    396:        struct proc *p;
                    397: {
                    398: #if INET
                    399:        /* Multicast goop, grrr... */
                    400: #if MROUTING
                    401:        return mrt_ioctl(req, data);
                    402: #else
                    403:        return mrt_ioctl(req, data, p);
                    404: #endif
                    405: #else /* INET */
                    406:        return ENXIO;
                    407: #endif /* INET */
                    408: }
                    409: 
                    410: struct ifaddr *
                    411: ifa_ifwithroute(flags, dst, gateway)
                    412:        int flags;
                    413:        struct sockaddr *dst, *gateway;
                    414: {
                    415:        register struct ifaddr *ifa;
                    416:        if ((flags & RTF_GATEWAY) == 0) {
                    417:                /*
                    418:                 * If we are adding a route to an interface,
                    419:                 * and the interface is a pt to pt link
                    420:                 * we should search for the destination
                    421:                 * as our clue to the interface.  Otherwise
                    422:                 * we can use the local address.
                    423:                 */
                    424:                ifa = 0;
                    425:                if (flags & RTF_HOST) {
                    426:                        ifa = ifa_ifwithdstaddr(dst);
                    427:                }
                    428:                if (ifa == 0)
                    429:                        ifa = ifa_ifwithaddr(gateway);
                    430:        } else {
                    431:                /*
                    432:                 * If we are adding a route to a remote net
                    433:                 * or host, the gateway may still be on the
                    434:                 * other end of a pt to pt link.
                    435:                 */
                    436:                ifa = ifa_ifwithdstaddr(gateway);
                    437:        }
                    438:        if (ifa == 0)
                    439:                ifa = ifa_ifwithnet(gateway);
                    440:        if (ifa == 0) {
                    441:                struct rtentry *rt = rtalloc1(dst, 0, 0UL);
                    442:                if (rt == 0)
                    443:                        return (0);
                    444:                rt->rt_refcnt--;
                    445:                if ((ifa = rt->rt_ifa) == 0)
                    446:                        return (0);
                    447:        }
                    448:        if (ifa->ifa_addr->sa_family != dst->sa_family) {
                    449:                struct ifaddr *oifa = ifa;
                    450:                ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
                    451:                if (ifa == 0)
                    452:                        ifa = oifa;
                    453:        }
                    454:        return (ifa);
                    455: }
                    456: 
                    457: #define ROUNDUP(a) (a>0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
                    458: 
                    459: static int rt_fixdelete __P((struct radix_node *, void *));
                    460: static int rt_fixchange __P((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:        int s = splnet(); int error = 0;
                    478:        register struct rtentry *rt;
                    479:        register struct radix_node *rn;
                    480:        register struct radix_node_head *rnh;
                    481:        struct ifaddr *ifa;
                    482:        struct sockaddr *ndst;
                    483: #define senderr(x) { error = x ; goto bad; }
                    484: 
                    485:        /*
                    486:         * Find the correct routing tree to use for this Address Family
                    487:         */
                    488:        if ((rnh = rt_tables[dst->sa_family]) == 0)
                    489:                senderr(ESRCH);
                    490:        /*
                    491:         * If we are adding a host route then we don't want to put
                    492:         * a netmask in the tree
                    493:         */
                    494:        if (flags & RTF_HOST)
                    495:                netmask = 0;
                    496:        switch (req) {
                    497:        case RTM_DELETE:
                    498:                /*
                    499:                 * Remove the item from the tree and return it.
                    500:                 * Complain if it is not there and do no more processing.
                    501:                 */
                    502:                if ((rn = rnh->rnh_deladdr(dst, netmask, rnh)) == 0)
                    503:                        senderr(ESRCH);
                    504:                if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT))
                    505:                        panic ("rtrequest delete");
                    506:                rt = (struct rtentry *)rn;
                    507: 
                    508:                /*
                    509:                 * Now search what's left of the subtree for any cloned
                    510:                 * routes which might have been formed from this node.
                    511:                 */
                    512:                if ((rt->rt_flags & RTF_PRCLONING) && netmask) {
                    513:                        rnh->rnh_walktree_from(rnh, dst, netmask,
                    514:                                               rt_fixdelete, rt);
                    515:                }
                    516: 
                    517:                /*
                    518:                 * Remove any external references we may have.
                    519:                 * This might result in another rtentry being freed if
                    520:                 * we held its last reference.
                    521:                 */
                    522:                if (rt->rt_gwroute) {
                    523:                        rt = rt->rt_gwroute;
                    524:                        RTFREE(rt);
                    525:                        (rt = (struct rtentry *)rn)->rt_gwroute = 0;
                    526:                }
                    527: 
                    528:                /*
                    529:                 * NB: RTF_UP must be set during the search above,
                    530:                 * because we might delete the last ref, causing
                    531:                 * rt to get freed prematurely.
                    532:                 *  eh? then why not just add a reference?
                    533:                 * I'm not sure how RTF_UP helps matters. (JRE)
                    534:                 */
                    535:                rt->rt_flags &= ~RTF_UP;
                    536: 
                    537:                /* 
                    538:                 * give the protocol a chance to keep things in sync.
                    539:                 */
                    540:                if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest)
                    541:                        ifa->ifa_rtrequest(RTM_DELETE, rt, SA(0));
                    542: 
                    543:                /*
                    544:                 * one more rtentry floating around that is not
                    545:                 * linked to the routing table.
                    546:                 */
                    547:                rttrash++;
                    548: 
                    549:                /*
                    550:                 * If the caller wants it, then it can have it,
                    551:                 * but it's up to it to free the rtentry as we won't be
                    552:                 * doing it.
                    553:                 */
                    554:                if (ret_nrt)
                    555:                        *ret_nrt = rt;
                    556:                else if (rt->rt_refcnt <= 0) {
                    557:                        rt->rt_refcnt++;
                    558:                        rtfree(rt);
                    559:                }
                    560:                break;
                    561: 
                    562:        case RTM_RESOLVE:
                    563:                if (ret_nrt == 0 || (rt = *ret_nrt) == 0)
                    564:                        senderr(EINVAL);
                    565:                ifa = rt->rt_ifa;
                    566:                flags = rt->rt_flags &
                    567:                    ~(RTF_CLONING | RTF_PRCLONING | RTF_STATIC);
                    568:                flags |= RTF_WASCLONED;
                    569:                gateway = rt->rt_gateway;
                    570:                if ((netmask = rt->rt_genmask) == 0)
                    571:                        flags |= RTF_HOST;
                    572:                goto makeroute;
                    573: 
                    574:        case RTM_ADD:
                    575:                if ((flags & RTF_GATEWAY) && !gateway)
                    576:                        panic("rtrequest: GATEWAY but no gateway");
                    577: 
                    578:                if ((ifa = ifa_ifwithroute(flags, dst, gateway)) == 0)
                    579:                        senderr(ENETUNREACH);
                    580: 
                    581:        makeroute:
                    582:                R_Malloc(rt, struct rtentry *, sizeof(*rt));
                    583:                if (rt == 0)
                    584:                        senderr(ENOBUFS);
                    585:                Bzero(rt, sizeof(*rt));
                    586:                rt->rt_flags = RTF_UP | flags;
                    587:                /*
                    588:                 * Add the gateway. Possibly re-malloc-ing the storage for it
                    589:                 * also add the rt_gwroute if possible.
                    590:                 */
                    591:                if (error = rt_setgate(rt, dst, gateway)) {
                    592:                        Free(rt);
                    593:                        senderr(error);
                    594:                }
                    595: 
                    596:                /*
                    597:                 * point to the (possibly newly malloc'd) dest address.
                    598:                 */
                    599:                ndst = rt_key(rt);
                    600: 
                    601:                /*
                    602:                 * make sure it contains the value we want (masked if needed).
                    603:                 */
                    604:                if (netmask) {
                    605:                        rt_maskedcopy(dst, ndst, netmask);
                    606:                } else
                    607:                        Bcopy(dst, ndst, dst->sa_len);
                    608: 
                    609:                /*
                    610:                 * Note that we now have a reference to the ifa.
                    611:                 * This moved from below so that rnh->rnh_addaddr() can
                    612:                 * examine the ifa and  ifa->ifa_ifp if it so desires.
                    613:                 */
                    614:                ifa->ifa_refcnt++;
                    615:                rt->rt_ifa = ifa;
                    616:                rt->rt_ifp = ifa->ifa_ifp;
                    617:                rt->rt_dlt = ifa->ifa_dlt;
                    618:                rn = rnh->rnh_addaddr((caddr_t)ndst, (caddr_t)netmask,
                    619:                                        rnh, rt->rt_nodes);
                    620:                if (rn == 0) {
                    621:                        struct rtentry *rt2;
                    622:                        /*
                    623:                         * Uh-oh, we already have one of these in the tree.
                    624:                         * We do a special hack: if the route that's already
                    625:                         * there was generated by the protocol-cloning
                    626:                         * mechanism, then we just blow it away and retry
                    627:                         * the insertion of the new one.
                    628:                         */
                    629:                        rt2 = rtalloc1(dst, 0, RTF_PRCLONING);
                    630:                        if (rt2 && rt2->rt_parent) {
                    631:                                rtrequest(RTM_DELETE, 
                    632:                                          (struct sockaddr *)rt_key(rt2),
                    633:                                          rt2->rt_gateway,
                    634:                                          rt_mask(rt2), rt2->rt_flags, 0);
                    635:                                RTFREE(rt2);
                    636:                                rn = rnh->rnh_addaddr((caddr_t)ndst,
                    637:                                                      (caddr_t)netmask,
                    638:                                                      rnh, rt->rt_nodes);
                    639:                        } else if (rt2) {
                    640:                                /* undo the extra ref we got */
                    641:                                RTFREE(rt2);
                    642:                        }
                    643:                }
                    644: 
                    645:                /*
                    646:                 * If it still failed to go into the tree,
                    647:                 * then un-make it (this should be a function)
                    648:                 */
                    649:                if (rn == 0) {
                    650:                        if (rt->rt_gwroute)
                    651:                                rtfree(rt->rt_gwroute);
                    652:                        if (rt->rt_ifa) {
                    653:                                IFAFREE(rt->rt_ifa);
                    654:                        }
                    655:                        Free(rt_key(rt));
                    656:                        Free(rt);
                    657:                        senderr(EEXIST);
                    658:                }
                    659: 
                    660:                rt->rt_parent = 0;
                    661: 
                    662:                /* 
                    663:                 * If we got here from RESOLVE, then we are cloning
                    664:                 * so clone the rest, and note that we 
                    665:                 * are a clone (and increment the parent's references)
                    666:                 */
                    667:                if (req == RTM_RESOLVE) {
                    668:                        rt->rt_rmx = (*ret_nrt)->rt_rmx; /* copy metrics */
                    669:                        if ((*ret_nrt)->rt_flags & RTF_PRCLONING) {
                    670:                                rt->rt_parent = (*ret_nrt);
                    671:                                (*ret_nrt)->rt_refcnt++;
                    672:                        }
                    673:                }
                    674: 
                    675:                /*
                    676:                 * if this protocol has something to add to this then
                    677:                 * allow it to do that as well.
                    678:                 */
                    679:                if (ifa->ifa_rtrequest)
                    680:                        ifa->ifa_rtrequest(req, rt, SA(ret_nrt ? *ret_nrt : 0));
                    681: 
                    682:                /*
                    683:                 * We repeat the same procedure from rt_setgate() here because
                    684:                 * it doesn't fire when we call it there because the node
                    685:                 * hasn't been added to the tree yet.
                    686:                 */
                    687:                if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != 0) {
                    688:                        struct rtfc_arg arg;
                    689:                        arg.rnh = rnh;
                    690:                        arg.rt0 = rt;
                    691:                        rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt),
                    692:                                               rt_fixchange, &arg);
                    693:                }
                    694: 
                    695:                /*
                    696:                 * actually return a resultant rtentry and
                    697:                 * give the caller a single reference.
                    698:                 */
                    699:                if (ret_nrt) {
                    700:                        *ret_nrt = rt;
                    701:                        rt->rt_refcnt++;
                    702:                }
                    703:                break;
                    704:        }
                    705: bad:
                    706:        splx(s);
                    707:        return (error);
                    708: }
                    709: 
                    710: /*
                    711:  * Called from rtrequest(RTM_DELETE, ...) to fix up the route's ``family''
                    712:  * (i.e., the routes related to it by the operation of cloning).  This
                    713:  * routine is iterated over all potential former-child-routes by way of
                    714:  * rnh->rnh_walktree_from() above, and those that actually are children of
                    715:  * the late parent (passed in as VP here) are themselves deleted.
                    716:  */
                    717: static int
                    718: rt_fixdelete(rn, vp)
                    719:        struct radix_node *rn;
                    720:        void *vp;
                    721: {
                    722:        struct rtentry *rt = (struct rtentry *)rn;
                    723:        struct rtentry *rt0 = vp;
                    724: 
                    725:        if (rt->rt_parent == rt0 && !(rt->rt_flags & RTF_PINNED)) {
                    726:                return rtrequest(RTM_DELETE, rt_key(rt),
                    727:                                 (struct sockaddr *)0, rt_mask(rt),
                    728:                                 rt->rt_flags, (struct rtentry **)0);
                    729:        }
                    730:        return 0;
                    731: }
                    732: 
                    733: /*
                    734:  * This routine is called from rt_setgate() to do the analogous thing for
                    735:  * adds and changes.  There is the added complication in this case of a
                    736:  * middle insert; i.e., insertion of a new network route between an older
                    737:  * network route and (cloned) host routes.  For this reason, a simple check
                    738:  * of rt->rt_parent is insufficient; each candidate route must be tested
                    739:  * against the (mask, value) of the new route (passed as before in vp)
                    740:  * to see if the new route matches it.  Unfortunately, this has the obnoxious
                    741:  * property of also triggering for insertion /above/ a pre-existing network
                    742:  * route and clones.  Sigh.  This may be fixed some day.
                    743:  *
                    744:  * XXX - it may be possible to do fixdelete() for changes and reserve this
                    745:  * routine just for adds.  I'm not sure why I thought it was necessary to do
                    746:  * changes this way.
                    747:  */
                    748: #ifdef DEBUG
                    749: static int rtfcdebug = 0;
                    750: #endif
                    751: 
                    752: static int
                    753: rt_fixchange(rn, vp)
                    754:        struct radix_node *rn;
                    755:        void *vp;
                    756: {
                    757:        struct rtentry *rt = (struct rtentry *)rn;
                    758:        struct rtfc_arg *ap = vp;
                    759:        struct rtentry *rt0 = ap->rt0;
                    760:        struct radix_node_head *rnh = ap->rnh;
                    761:        u_char *xk1, *xm1, *xk2;
                    762:        int i, len;
                    763: 
                    764: #ifdef DEBUG
                    765:        if (rtfcdebug)
                    766:                printf("rt_fixchange: rt %p, rt0 %p\n", rt, rt0);
                    767: #endif
                    768: 
                    769:        if (!rt->rt_parent || (rt->rt_flags & RTF_PINNED)) {
                    770: #ifdef DEBUG
                    771:                if(rtfcdebug) printf("no parent or pinned\n");
                    772: #endif
                    773:                return 0;
                    774:        }
                    775: 
                    776:        if (rt->rt_parent == rt0) {
                    777: #ifdef DEBUG
                    778:                if(rtfcdebug) printf("parent match\n");
                    779: #endif
                    780:                return rtrequest(RTM_DELETE, rt_key(rt),
                    781:                                 (struct sockaddr *)0, rt_mask(rt),
                    782:                                 rt->rt_flags, (struct rtentry **)0);
                    783:        }
                    784: 
                    785:        /*
                    786:         * There probably is a function somewhere which does this...
                    787:         * if not, there should be.
                    788:         */
                    789:        len = imin(((struct sockaddr *)rt_key(rt0))->sa_len,
                    790:                   ((struct sockaddr *)rt_key(rt))->sa_len);
                    791: 
                    792:        xk1 = (u_char *)rt_key(rt0);
                    793:        xm1 = (u_char *)rt_mask(rt0);
                    794:        xk2 = (u_char *)rt_key(rt);
                    795: 
                    796:        for (i = rnh->rnh_treetop->rn_off; i < len; i++) {
                    797:                if ((xk2[i] & xm1[i]) != xk1[i]) {
                    798: #ifdef DEBUG
                    799:                        if(rtfcdebug) printf("no match\n");
                    800: #endif
                    801:                        return 0;
                    802:                }
                    803:        }
                    804: 
                    805:        /*
                    806:         * OK, this node is a clone, and matches the node currently being
                    807:         * changed/added under the node's mask.  So, get rid of it.
                    808:         */
                    809: #ifdef DEBUG
                    810:        if(rtfcdebug) printf("deleting\n");
                    811: #endif
                    812:        return rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0,
                    813:                         rt_mask(rt), rt->rt_flags, (struct rtentry **)0);
                    814: }
                    815: 
                    816: int
                    817: rt_setgate(rt0, dst, gate)
                    818:        struct rtentry *rt0;
                    819:        struct sockaddr *dst, *gate;
                    820: {
                    821:        caddr_t new, old;
                    822:        int dlen = ROUNDUP(dst->sa_len), glen = ROUNDUP(gate->sa_len);
                    823:        register struct rtentry *rt = rt0;
                    824:        struct radix_node_head *rnh = rt_tables[dst->sa_family];
                    825: 
                    826:        /*
                    827:         * A host route with the destination equal to the gateway
                    828:         * will interfere with keeping LLINFO in the routing
                    829:         * table, so disallow it.
                    830:         */
                    831:        if (((rt0->rt_flags & (RTF_HOST|RTF_GATEWAY|RTF_LLINFO)) ==
                    832:                                        (RTF_HOST|RTF_GATEWAY)) &&
                    833:            (dst->sa_len == gate->sa_len) &&
                    834:            (bcmp(dst, gate, dst->sa_len) == 0)) {
                    835:                /*
                    836:                 * The route might already exist if this is an RTM_CHANGE
                    837:                 * or a routing redirect, so try to delete it.
                    838:                 */
                    839:                if (rt_key(rt0))
                    840:                        rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt0),
                    841:                            rt0->rt_gateway, rt_mask(rt0), rt0->rt_flags, 0);
                    842:                return EADDRNOTAVAIL;
                    843:        }
                    844: 
                    845:        /*
                    846:         * Both dst and gateway are stored in the same malloc'd chunk
                    847:         * (If I ever get my hands on....)
                    848:         * if we need to malloc a new chunk, then keep the old one around
                    849:         * till we don't need it any more.
                    850:         */
                    851:        if (rt->rt_gateway == 0 || glen > ROUNDUP(rt->rt_gateway->sa_len)) {
                    852:                old = (caddr_t)rt_key(rt);
                    853:                R_Malloc(new, caddr_t, dlen + glen);
                    854:                if (new == 0)
                    855:                        return ENOBUFS;
                    856:                rt->rt_nodes->rn_key = new;
                    857:        } else {
                    858:                /*
                    859:                 * otherwise just overwrite the old one
                    860:                 */
                    861:                new = rt->rt_nodes->rn_key;
                    862:                old = 0;
                    863:        }
                    864: 
                    865:        /*
                    866:         * copy the new gateway value into the memory chunk
                    867:         */
                    868:        Bcopy(gate, (rt->rt_gateway = (struct sockaddr *)(new + dlen)), glen);
                    869: 
                    870:        /* 
                    871:         * if we are replacing the chunk (or it's new) we need to 
                    872:         * replace the dst as well
                    873:         */
                    874:        if (old) {
                    875:                Bcopy(dst, new, dlen);
                    876:                Free(old);
                    877:        }
                    878: 
                    879:        /*
                    880:         * If there is already a gwroute, it's now almost definitly wrong
                    881:         * so drop it.
                    882:         */
                    883:        if (rt->rt_gwroute) {
                    884:                rt = rt->rt_gwroute; RTFREE(rt);
                    885:                rt = rt0; rt->rt_gwroute = 0;
                    886:        }
                    887:        /*
                    888:         * Cloning loop avoidance:
                    889:         * In the presence of protocol-cloning and bad configuration,
                    890:         * it is possible to get stuck in bottomless mutual recursion
                    891:         * (rtrequest rt_setgate rtalloc1).  We avoid this by not allowing
                    892:         * protocol-cloning to operate for gateways (which is probably the
                    893:         * correct choice anyway), and avoid the resulting reference loops
                    894:         * by disallowing any route to run through itself as a gateway.
                    895:         * This is obviously mandatory when we get rt->rt_output().
                    896:         */
                    897:        if (rt->rt_flags & RTF_GATEWAY) {
                    898:                rt->rt_gwroute = rtalloc1(gate, 1, RTF_PRCLONING);
                    899:                if (rt->rt_gwroute == rt) {
                    900:                        RTFREE(rt->rt_gwroute);
                    901:                        rt->rt_gwroute = 0;
                    902:                        return EDQUOT; /* failure */
                    903:                }
                    904:        }
                    905: 
                    906:        /*
                    907:         * This isn't going to do anything useful for host routes, so
                    908:         * don't bother.  Also make sure we have a reasonable mask
                    909:         * (we don't yet have one during adds).
                    910:         */
                    911:        if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != 0) {
                    912:                struct rtfc_arg arg;
                    913:                arg.rnh = rnh;
                    914:                arg.rt0 = rt;
                    915:                rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt),
                    916:                                       rt_fixchange, &arg);
                    917:        }
                    918: 
                    919:        return 0;
                    920: }
                    921: 
                    922: static void
                    923: rt_maskedcopy(src, dst, netmask)
                    924:        struct sockaddr *src, *dst, *netmask;
                    925: {
                    926:        register u_char *cp1 = (u_char *)src;
                    927:        register u_char *cp2 = (u_char *)dst;
                    928:        register u_char *cp3 = (u_char *)netmask;
                    929:        u_char *cplim = cp2 + *cp3;
                    930:        u_char *cplim2 = cp2 + *cp1;
                    931: 
                    932:        *cp2++ = *cp1++; *cp2++ = *cp1++; /* copies sa_len & sa_family */
                    933:        cp3 += 2;
                    934:        if (cplim > cplim2)
                    935:                cplim = cplim2;
                    936:        while (cp2 < cplim)
                    937:                *cp2++ = *cp1++ & *cp3++;
                    938:        if (cp2 < cplim2)
                    939:                bzero((caddr_t)cp2, (unsigned)(cplim2 - cp2));
                    940: }
                    941: 
                    942: /*
                    943:  * Set up a routing table entry, normally
                    944:  * for an interface.
                    945:  */
                    946: int
                    947: rtinit(ifa, cmd, flags)
                    948:        register struct ifaddr *ifa;
                    949:        int cmd, flags;
                    950: {
                    951:        register struct rtentry *rt;
                    952:        register struct sockaddr *dst;
                    953:        register struct sockaddr *deldst;
                    954:        struct mbuf *m = 0;
                    955:        struct rtentry *nrt = 0;
                    956:        int error;
                    957: 
                    958:        dst = flags & RTF_HOST ? ifa->ifa_dstaddr : ifa->ifa_addr;
                    959:        /*
                    960:         * If it's a delete, check that if it exists, it's on the correct
                    961:         * interface or we might scrub a route to another ifa which would
                    962:         * be confusing at best and possibly worse.
                    963:         */
                    964:        if (cmd == RTM_DELETE) {
                    965:                /* 
                    966:                 * It's a delete, so it should already exist..
                    967:                 * If it's a net, mask off the host bits
                    968:                 * (Assuming we have a mask)
                    969:                 */
                    970:                if ((flags & RTF_HOST) == 0 && ifa->ifa_netmask) {
                    971:                        m = m_get(M_WAIT, MT_SONAME);
                    972:                        deldst = mtod(m, struct sockaddr *);
                    973:                        rt_maskedcopy(dst, deldst, ifa->ifa_netmask);
                    974:                        dst = deldst;
                    975:                }
                    976:                /*
                    977:                 * Get an rtentry that is in the routing tree and
                    978:                 * contains the correct info. (if this fails, can't get there).
                    979:                 * We set "report" to FALSE so that if it doesn't exist,
                    980:                 * it doesn't report an error or clone a route, etc. etc.
                    981:                 */
                    982:                rt = rtalloc1(dst, 0, 0UL);
                    983:                if (rt) {
                    984:                        /*
                    985:                         * Ok so we found the rtentry. it has an extra reference
                    986:                         * for us at this stage. we won't need that so
                    987:                         * lop that off now.
                    988:                         */
                    989:                        rt->rt_refcnt--;
                    990:                        if (rt->rt_ifa != ifa) {
                    991:                                /*
                    992:                                 * If the interface in the rtentry doesn't match
                    993:                                 * the interface we are using, then we don't
                    994:                                 * want to delete it, so return an error.
                    995:                                 * This seems to be the only point of 
                    996:                                 * this whole RTM_DELETE clause.
                    997:                                 */
                    998:                                if (m)
                    999:                                        (void) m_free(m);
                   1000:                                return (flags & RTF_HOST ? EHOSTUNREACH
                   1001:                                                        : ENETUNREACH);
                   1002:                        }
                   1003:                }
                   1004:                /* XXX */
                   1005: #if 0
                   1006:                else {
                   1007:                        /* 
                   1008:                         * One would think that as we are deleting, and we know
                   1009:                         * it doesn't exist, we could just return at this point
                   1010:                         * with an "ELSE" clause, but apparently not..
                   1011:                         */
                   1012:                        return (flags & RTF_HOST ? EHOSTUNREACH
                   1013:                                                        : ENETUNREACH);
                   1014:                }
                   1015: #endif
                   1016:        }
                   1017:        /*
                   1018:         * Do the actual request
                   1019:         */
                   1020:        error = rtrequest(cmd, dst, ifa->ifa_addr, ifa->ifa_netmask,
                   1021:                        flags | ifa->ifa_flags, &nrt);
                   1022:        if (m)
                   1023:                (void) m_free(m);
                   1024:        /*
                   1025:         * If we are deleting, and we found an entry, then
                   1026:         * it's been removed from the tree.. now throw it away.
                   1027:         */
                   1028:        if (cmd == RTM_DELETE && error == 0 && (rt = nrt)) {
                   1029:                /*
                   1030:                 * notify any listenning routing agents of the change
                   1031:                 */
                   1032:                rt_newaddrmsg(cmd, ifa, error, nrt);
                   1033:                if (rt->rt_refcnt <= 0) {
                   1034:                        rt->rt_refcnt++;
                   1035:                        rtfree(rt);
                   1036:                }
                   1037:        }
                   1038: 
                   1039:        /*
                   1040:         * We are adding, and we have a returned routing entry.
                   1041:         * We need to sanity check the result.
                   1042:         */
                   1043:        if (cmd == RTM_ADD && error == 0 && (rt = nrt)) {
                   1044:                /*
                   1045:                 * We just wanted to add it.. we don't actually need a reference
                   1046:                 */
                   1047:                rt->rt_refcnt--;
                   1048:                /*
                   1049:                 * If it came back with an unexpected interface, then it must 
                   1050:                 * have already existed or something. (XXX)
                   1051:                 */
                   1052:                if (rt->rt_ifa != ifa) {
                   1053:                        printf("rtinit: wrong ifa (%p) was (%p)\n", ifa,
                   1054:                                rt->rt_ifa);
                   1055:                        /*
                   1056:                         * Ask that the protocol in question
                   1057:                         * remove anything it has associated with
                   1058:                         * this route and ifaddr.
                   1059:                         */
                   1060:                        if (rt->rt_ifa->ifa_rtrequest)
                   1061:                            rt->rt_ifa->ifa_rtrequest(RTM_DELETE, rt, SA(0));
                   1062:                        /* 
                   1063:                         * Remove the referenve to the it's ifaddr.
                   1064:                         */
                   1065:                        IFAFREE(rt->rt_ifa);
                   1066:                        /*
                   1067:                         * And substitute in references to the ifaddr
                   1068:                         * we are adding.
                   1069:                         */
                   1070:                        rt->rt_ifa = ifa;
                   1071:                        rt->rt_ifp = ifa->ifa_ifp;
                   1072:                        rt->rt_dlt = ifa->ifa_dlt;
                   1073:                        ifa->ifa_refcnt++;
                   1074:                        /*
                   1075:                         * Now ask the protocol to check if it needs
                   1076:                         * any special processing in its new form.
                   1077:                         */
                   1078:                        if (ifa->ifa_rtrequest)
                   1079:                            ifa->ifa_rtrequest(RTM_ADD, rt, SA(0));
                   1080:                }
                   1081:                /*
                   1082:                 * notify any listenning routing agents of the change
                   1083:                 */
                   1084:                rt_newaddrmsg(cmd, ifa, error, nrt);
                   1085:        }
                   1086:        return (error);
                   1087: }

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