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Annotation of src/sys/netinet/ip_input.c, Revision 1.23

1.23    ! mycroft     1: /*     $NetBSD: ip_input.c,v 1.22 1995/06/12 00:47:41 mycroft Exp $    */
1.14      cgd         2:
1.1       cgd         3: /*
1.13      mycroft     4:  * Copyright (c) 1982, 1986, 1988, 1993
                      5:  *     The Regents of the University of California.  All rights reserved.
1.1       cgd         6:  *
                      7:  * Redistribution and use in source and binary forms, with or without
                      8:  * modification, are permitted provided that the following conditions
                      9:  * are met:
                     10:  * 1. Redistributions of source code must retain the above copyright
                     11:  *    notice, this list of conditions and the following disclaimer.
                     12:  * 2. Redistributions in binary form must reproduce the above copyright
                     13:  *    notice, this list of conditions and the following disclaimer in the
                     14:  *    documentation and/or other materials provided with the distribution.
                     15:  * 3. All advertising materials mentioning features or use of this software
                     16:  *    must display the following acknowledgement:
                     17:  *     This product includes software developed by the University of
                     18:  *     California, Berkeley and its contributors.
                     19:  * 4. Neither the name of the University nor the names of its contributors
                     20:  *    may be used to endorse or promote products derived from this software
                     21:  *    without specific prior written permission.
                     22:  *
                     23:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     24:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     25:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     26:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     27:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     28:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     29:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     30:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     31:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     32:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     33:  * SUCH DAMAGE.
                     34:  *
1.14      cgd        35:  *     @(#)ip_input.c  8.2 (Berkeley) 1/4/94
1.1       cgd        36:  */
                     37:
1.5       mycroft    38: #include <sys/param.h>
                     39: #include <sys/systm.h>
                     40: #include <sys/malloc.h>
                     41: #include <sys/mbuf.h>
                     42: #include <sys/domain.h>
                     43: #include <sys/protosw.h>
                     44: #include <sys/socket.h>
                     45: #include <sys/errno.h>
                     46: #include <sys/time.h>
                     47: #include <sys/kernel.h>
1.1       cgd        48:
1.5       mycroft    49: #include <net/if.h>
                     50: #include <net/route.h>
1.1       cgd        51:
1.5       mycroft    52: #include <netinet/in.h>
                     53: #include <netinet/in_systm.h>
                     54: #include <netinet/ip.h>
                     55: #include <netinet/in_pcb.h>
                     56: #include <netinet/in_var.h>
                     57: #include <netinet/ip_var.h>
                     58: #include <netinet/ip_icmp.h>
1.1       cgd        59:
                     60: #ifndef        IPFORWARDING
                     61: #ifdef GATEWAY
                     62: #define        IPFORWARDING    1       /* forward IP packets not for us */
                     63: #else /* GATEWAY */
                     64: #define        IPFORWARDING    0       /* don't forward IP packets not for us */
                     65: #endif /* GATEWAY */
                     66: #endif /* IPFORWARDING */
                     67: #ifndef        IPSENDREDIRECTS
                     68: #define        IPSENDREDIRECTS 1
                     69: #endif
                     70: int    ipforwarding = IPFORWARDING;
                     71: int    ipsendredirects = IPSENDREDIRECTS;
1.13      mycroft    72: int    ip_defttl = IPDEFTTL;
1.1       cgd        73: #ifdef DIAGNOSTIC
                     74: int    ipprintfs = 0;
                     75: #endif
                     76:
                     77: extern struct domain inetdomain;
                     78: extern struct protosw inetsw[];
                     79: u_char ip_protox[IPPROTO_MAX];
                     80: int    ipqmaxlen = IFQ_MAXLEN;
1.22      mycroft    81: struct in_ifaddrhead in_ifaddr;
1.13      mycroft    82: struct ifqueue ipintrq;
1.1       cgd        83:
                     84: /*
                     85:  * We need to save the IP options in case a protocol wants to respond
                     86:  * to an incoming packet over the same route if the packet got here
                     87:  * using IP source routing.  This allows connection establishment and
                     88:  * maintenance when the remote end is on a network that is not known
                     89:  * to us.
                     90:  */
                     91: int    ip_nhops = 0;
                     92: static struct ip_srcrt {
                     93:        struct  in_addr dst;                    /* final destination */
                     94:        char    nop;                            /* one NOP to align */
                     95:        char    srcopt[IPOPT_OFFSET + 1];       /* OPTVAL, OLEN and OFFSET */
                     96:        struct  in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
                     97: } ip_srcrt;
                     98:
1.13      mycroft    99: static void save_rte __P((u_char *, struct in_addr));
1.1       cgd       100: /*
                    101:  * IP initialization: fill in IP protocol switch table.
                    102:  * All protocols not implemented in kernel go to raw IP protocol handler.
                    103:  */
1.8       mycroft   104: void
1.1       cgd       105: ip_init()
                    106: {
                    107:        register struct protosw *pr;
                    108:        register int i;
                    109:
                    110:        pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
                    111:        if (pr == 0)
                    112:                panic("ip_init");
                    113:        for (i = 0; i < IPPROTO_MAX; i++)
                    114:                ip_protox[i] = pr - inetsw;
                    115:        for (pr = inetdomain.dom_protosw;
                    116:            pr < inetdomain.dom_protoswNPROTOSW; pr++)
                    117:                if (pr->pr_domain->dom_family == PF_INET &&
                    118:                    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
                    119:                        ip_protox[pr->pr_protocol] = pr - inetsw;
                    120:        ipq.next = ipq.prev = &ipq;
                    121:        ip_id = time.tv_sec & 0xffff;
                    122:        ipintrq.ifq_maxlen = ipqmaxlen;
1.22      mycroft   123:        TAILQ_INIT(&in_ifaddr);
1.1       cgd       124: }
                    125:
                    126: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
                    127: struct route ipforward_rt;
                    128:
                    129: /*
                    130:  * Ip input routine.  Checksum and byte swap header.  If fragmented
                    131:  * try to reassemble.  Process options.  Pass to next level.
                    132:  */
1.8       mycroft   133: void
1.1       cgd       134: ipintr()
                    135: {
                    136:        register struct ip *ip;
                    137:        register struct mbuf *m;
                    138:        register struct ipq *fp;
                    139:        register struct in_ifaddr *ia;
                    140:        int hlen, s;
                    141:
                    142: next:
                    143:        /*
                    144:         * Get next datagram off input queue and get IP header
                    145:         * in first mbuf.
                    146:         */
                    147:        s = splimp();
                    148:        IF_DEQUEUE(&ipintrq, m);
                    149:        splx(s);
1.13      mycroft   150:        if (m == 0)
1.1       cgd       151:                return;
                    152: #ifdef DIAGNOSTIC
                    153:        if ((m->m_flags & M_PKTHDR) == 0)
                    154:                panic("ipintr no HDR");
                    155: #endif
                    156:        /*
                    157:         * If no IP addresses have been set yet but the interfaces
                    158:         * are receiving, can't do anything with incoming packets yet.
                    159:         */
1.22      mycroft   160:        if (in_ifaddr.tqh_first == 0)
1.1       cgd       161:                goto bad;
                    162:        ipstat.ips_total++;
                    163:        if (m->m_len < sizeof (struct ip) &&
                    164:            (m = m_pullup(m, sizeof (struct ip))) == 0) {
                    165:                ipstat.ips_toosmall++;
                    166:                goto next;
                    167:        }
                    168:        ip = mtod(m, struct ip *);
1.13      mycroft   169:        if (ip->ip_v != IPVERSION) {
                    170:                ipstat.ips_badvers++;
                    171:                goto bad;
                    172:        }
1.1       cgd       173:        hlen = ip->ip_hl << 2;
                    174:        if (hlen < sizeof(struct ip)) { /* minimum header length */
                    175:                ipstat.ips_badhlen++;
                    176:                goto bad;
                    177:        }
                    178:        if (hlen > m->m_len) {
                    179:                if ((m = m_pullup(m, hlen)) == 0) {
                    180:                        ipstat.ips_badhlen++;
                    181:                        goto next;
                    182:                }
                    183:                ip = mtod(m, struct ip *);
                    184:        }
                    185:        if (ip->ip_sum = in_cksum(m, hlen)) {
                    186:                ipstat.ips_badsum++;
                    187:                goto bad;
                    188:        }
                    189:
                    190:        /*
                    191:         * Convert fields to host representation.
                    192:         */
                    193:        NTOHS(ip->ip_len);
                    194:        if (ip->ip_len < hlen) {
                    195:                ipstat.ips_badlen++;
                    196:                goto bad;
                    197:        }
                    198:        NTOHS(ip->ip_id);
                    199:        NTOHS(ip->ip_off);
                    200:
                    201:        /*
                    202:         * Check that the amount of data in the buffers
                    203:         * is as at least much as the IP header would have us expect.
                    204:         * Trim mbufs if longer than we expect.
                    205:         * Drop packet if shorter than we expect.
                    206:         */
                    207:        if (m->m_pkthdr.len < ip->ip_len) {
                    208:                ipstat.ips_tooshort++;
                    209:                goto bad;
                    210:        }
                    211:        if (m->m_pkthdr.len > ip->ip_len) {
                    212:                if (m->m_len == m->m_pkthdr.len) {
                    213:                        m->m_len = ip->ip_len;
                    214:                        m->m_pkthdr.len = ip->ip_len;
                    215:                } else
                    216:                        m_adj(m, ip->ip_len - m->m_pkthdr.len);
                    217:        }
                    218:
                    219:        /*
                    220:         * Process options and, if not destined for us,
                    221:         * ship it on.  ip_dooptions returns 1 when an
                    222:         * error was detected (causing an icmp message
                    223:         * to be sent and the original packet to be freed).
                    224:         */
                    225:        ip_nhops = 0;           /* for source routed packets */
                    226:        if (hlen > sizeof (struct ip) && ip_dooptions(m))
                    227:                goto next;
                    228:
                    229:        /*
                    230:         * Check our list of addresses, to see if the packet is for us.
                    231:         */
1.22      mycroft   232:        for (ia = in_ifaddr.tqh_first; ia; ia = ia->ia_list.tqe_next) {
1.20      mycroft   233:                if (ip->ip_dst.s_addr == ia->ia_addr.sin_addr.s_addr)
1.1       cgd       234:                        goto ours;
                    235:                if (
                    236: #ifdef DIRECTED_BROADCAST
                    237:                    ia->ia_ifp == m->m_pkthdr.rcvif &&
                    238: #endif
                    239:                    (ia->ia_ifp->if_flags & IFF_BROADCAST)) {
1.20      mycroft   240:                        if (ip->ip_dst.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
                    241:                            ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr ||
                    242:                            /*
                    243:                             * Look for all-0's host part (old broadcast addr),
                    244:                             * either for subnet or net.
                    245:                             */
                    246:                            ip->ip_dst.s_addr == ia->ia_subnet ||
1.18      mycroft   247:                            ip->ip_dst.s_addr == ia->ia_net)
1.1       cgd       248:                                goto ours;
                    249:                }
                    250:        }
1.18      mycroft   251:        if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4       hpeyerl   252:                struct in_multi *inm;
                    253: #ifdef MROUTING
                    254:                extern struct socket *ip_mrouter;
1.10      brezak    255:
                    256:                if (m->m_flags & M_EXT) {
                    257:                        if ((m = m_pullup(m, hlen)) == 0) {
                    258:                                ipstat.ips_toosmall++;
                    259:                                goto next;
                    260:                        }
                    261:                        ip = mtod(m, struct ip *);
                    262:                }
1.4       hpeyerl   263:
                    264:                if (ip_mrouter) {
                    265:                        /*
                    266:                         * If we are acting as a multicast router, all
                    267:                         * incoming multicast packets are passed to the
                    268:                         * kernel-level multicast forwarding function.
                    269:                         * The packet is returned (relatively) intact; if
                    270:                         * ip_mforward() returns a non-zero value, the packet
                    271:                         * must be discarded, else it may be accepted below.
                    272:                         *
                    273:                         * (The IP ident field is put in the same byte order
                    274:                         * as expected when ip_mforward() is called from
                    275:                         * ip_output().)
                    276:                         */
                    277:                        ip->ip_id = htons(ip->ip_id);
1.13      mycroft   278:                        if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
                    279:                                ipstat.ips_cantforward++;
1.4       hpeyerl   280:                                m_freem(m);
                    281:                                goto next;
                    282:                        }
                    283:                        ip->ip_id = ntohs(ip->ip_id);
                    284:
                    285:                        /*
                    286:                         * The process-level routing demon needs to receive
                    287:                         * all multicast IGMP packets, whether or not this
                    288:                         * host belongs to their destination groups.
                    289:                         */
                    290:                        if (ip->ip_p == IPPROTO_IGMP)
                    291:                                goto ours;
1.13      mycroft   292:                        ipstat.ips_forward++;
1.4       hpeyerl   293:                }
                    294: #endif
                    295:                /*
                    296:                 * See if we belong to the destination multicast group on the
                    297:                 * arrival interface.
                    298:                 */
                    299:                IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
                    300:                if (inm == NULL) {
1.13      mycroft   301:                        ipstat.ips_cantforward++;
1.4       hpeyerl   302:                        m_freem(m);
                    303:                        goto next;
                    304:                }
                    305:                goto ours;
                    306:        }
1.19      mycroft   307:        if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
                    308:            ip->ip_dst.s_addr == INADDR_ANY)
1.1       cgd       309:                goto ours;
                    310:
                    311:        /*
                    312:         * Not for us; forward if possible and desirable.
                    313:         */
                    314:        if (ipforwarding == 0) {
                    315:                ipstat.ips_cantforward++;
                    316:                m_freem(m);
                    317:        } else
                    318:                ip_forward(m, 0);
                    319:        goto next;
                    320:
                    321: ours:
                    322:        /*
                    323:         * If offset or IP_MF are set, must reassemble.
                    324:         * Otherwise, nothing need be done.
                    325:         * (We could look in the reassembly queue to see
                    326:         * if the packet was previously fragmented,
                    327:         * but it's not worth the time; just let them time out.)
                    328:         */
                    329:        if (ip->ip_off &~ IP_DF) {
                    330:                if (m->m_flags & M_EXT) {               /* XXX */
                    331:                        if ((m = m_pullup(m, sizeof (struct ip))) == 0) {
                    332:                                ipstat.ips_toosmall++;
                    333:                                goto next;
                    334:                        }
                    335:                        ip = mtod(m, struct ip *);
                    336:                }
                    337:                /*
                    338:                 * Look for queue of fragments
                    339:                 * of this datagram.
                    340:                 */
                    341:                for (fp = ipq.next; fp != &ipq; fp = fp->next)
                    342:                        if (ip->ip_id == fp->ipq_id &&
                    343:                            ip->ip_src.s_addr == fp->ipq_src.s_addr &&
                    344:                            ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
                    345:                            ip->ip_p == fp->ipq_p)
                    346:                                goto found;
                    347:                fp = 0;
                    348: found:
                    349:
                    350:                /*
                    351:                 * Adjust ip_len to not reflect header,
                    352:                 * set ip_mff if more fragments are expected,
                    353:                 * convert offset of this to bytes.
                    354:                 */
                    355:                ip->ip_len -= hlen;
1.13      mycroft   356:                ((struct ipasfrag *)ip)->ipf_mff &= ~1;
1.16      cgd       357:                if (ip->ip_off & IP_MF) {
                    358:                        /*
                    359:                         * Make sure that fragments have a data length
                    360:                         * that's a non-zero multiple of 8 bytes.
                    361:                         */
1.17      cgd       362:                        if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16      cgd       363:                                ipstat.ips_badfrags++;
                    364:                                goto bad;
                    365:                        }
1.13      mycroft   366:                        ((struct ipasfrag *)ip)->ipf_mff |= 1;
1.16      cgd       367:                }
1.1       cgd       368:                ip->ip_off <<= 3;
                    369:
                    370:                /*
                    371:                 * If datagram marked as having more fragments
                    372:                 * or if this is not the first fragment,
                    373:                 * attempt reassembly; if it succeeds, proceed.
                    374:                 */
1.13      mycroft   375:                if (((struct ipasfrag *)ip)->ipf_mff & 1 || ip->ip_off) {
1.1       cgd       376:                        ipstat.ips_fragments++;
                    377:                        ip = ip_reass((struct ipasfrag *)ip, fp);
                    378:                        if (ip == 0)
                    379:                                goto next;
1.13      mycroft   380:                        ipstat.ips_reassembled++;
1.1       cgd       381:                        m = dtom(ip);
                    382:                } else
                    383:                        if (fp)
                    384:                                ip_freef(fp);
                    385:        } else
                    386:                ip->ip_len -= hlen;
                    387:
                    388:        /*
                    389:         * Switch out to protocol's input routine.
                    390:         */
                    391:        ipstat.ips_delivered++;
                    392:        (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
                    393:        goto next;
                    394: bad:
                    395:        m_freem(m);
                    396:        goto next;
                    397: }
                    398:
                    399: /*
                    400:  * Take incoming datagram fragment and try to
                    401:  * reassemble it into whole datagram.  If a chain for
                    402:  * reassembly of this datagram already exists, then it
                    403:  * is given as fp; otherwise have to make a chain.
                    404:  */
                    405: struct ip *
                    406: ip_reass(ip, fp)
                    407:        register struct ipasfrag *ip;
                    408:        register struct ipq *fp;
                    409: {
                    410:        register struct mbuf *m = dtom(ip);
                    411:        register struct ipasfrag *q;
                    412:        struct mbuf *t;
                    413:        int hlen = ip->ip_hl << 2;
                    414:        int i, next;
                    415:
                    416:        /*
                    417:         * Presence of header sizes in mbufs
                    418:         * would confuse code below.
                    419:         */
                    420:        m->m_data += hlen;
                    421:        m->m_len -= hlen;
                    422:
                    423:        /*
                    424:         * If first fragment to arrive, create a reassembly queue.
                    425:         */
                    426:        if (fp == 0) {
                    427:                if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
                    428:                        goto dropfrag;
                    429:                fp = mtod(t, struct ipq *);
                    430:                insque(fp, &ipq);
                    431:                fp->ipq_ttl = IPFRAGTTL;
                    432:                fp->ipq_p = ip->ip_p;
                    433:                fp->ipq_id = ip->ip_id;
                    434:                fp->ipq_next = fp->ipq_prev = (struct ipasfrag *)fp;
                    435:                fp->ipq_src = ((struct ip *)ip)->ip_src;
                    436:                fp->ipq_dst = ((struct ip *)ip)->ip_dst;
                    437:                q = (struct ipasfrag *)fp;
                    438:                goto insert;
                    439:        }
                    440:
                    441:        /*
                    442:         * Find a segment which begins after this one does.
                    443:         */
                    444:        for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next)
                    445:                if (q->ip_off > ip->ip_off)
                    446:                        break;
                    447:
                    448:        /*
                    449:         * If there is a preceding segment, it may provide some of
                    450:         * our data already.  If so, drop the data from the incoming
                    451:         * segment.  If it provides all of our data, drop us.
                    452:         */
                    453:        if (q->ipf_prev != (struct ipasfrag *)fp) {
                    454:                i = q->ipf_prev->ip_off + q->ipf_prev->ip_len - ip->ip_off;
                    455:                if (i > 0) {
                    456:                        if (i >= ip->ip_len)
                    457:                                goto dropfrag;
                    458:                        m_adj(dtom(ip), i);
                    459:                        ip->ip_off += i;
                    460:                        ip->ip_len -= i;
                    461:                }
                    462:        }
                    463:
                    464:        /*
                    465:         * While we overlap succeeding segments trim them or,
                    466:         * if they are completely covered, dequeue them.
                    467:         */
                    468:        while (q != (struct ipasfrag *)fp && ip->ip_off + ip->ip_len > q->ip_off) {
                    469:                i = (ip->ip_off + ip->ip_len) - q->ip_off;
                    470:                if (i < q->ip_len) {
                    471:                        q->ip_len -= i;
                    472:                        q->ip_off += i;
                    473:                        m_adj(dtom(q), i);
                    474:                        break;
                    475:                }
                    476:                q = q->ipf_next;
                    477:                m_freem(dtom(q->ipf_prev));
                    478:                ip_deq(q->ipf_prev);
                    479:        }
                    480:
                    481: insert:
                    482:        /*
                    483:         * Stick new segment in its place;
                    484:         * check for complete reassembly.
                    485:         */
                    486:        ip_enq(ip, q->ipf_prev);
                    487:        next = 0;
                    488:        for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next) {
                    489:                if (q->ip_off != next)
                    490:                        return (0);
                    491:                next += q->ip_len;
                    492:        }
1.13      mycroft   493:        if (q->ipf_prev->ipf_mff & 1)
1.1       cgd       494:                return (0);
                    495:
                    496:        /*
                    497:         * Reassembly is complete; concatenate fragments.
                    498:         */
                    499:        q = fp->ipq_next;
                    500:        m = dtom(q);
                    501:        t = m->m_next;
                    502:        m->m_next = 0;
                    503:        m_cat(m, t);
                    504:        q = q->ipf_next;
                    505:        while (q != (struct ipasfrag *)fp) {
                    506:                t = dtom(q);
                    507:                q = q->ipf_next;
                    508:                m_cat(m, t);
                    509:        }
                    510:
                    511:        /*
                    512:         * Create header for new ip packet by
                    513:         * modifying header of first packet;
                    514:         * dequeue and discard fragment reassembly header.
                    515:         * Make header visible.
                    516:         */
                    517:        ip = fp->ipq_next;
                    518:        ip->ip_len = next;
1.13      mycroft   519:        ip->ipf_mff &= ~1;
1.1       cgd       520:        ((struct ip *)ip)->ip_src = fp->ipq_src;
                    521:        ((struct ip *)ip)->ip_dst = fp->ipq_dst;
                    522:        remque(fp);
                    523:        (void) m_free(dtom(fp));
                    524:        m = dtom(ip);
                    525:        m->m_len += (ip->ip_hl << 2);
                    526:        m->m_data -= (ip->ip_hl << 2);
                    527:        /* some debugging cruft by sklower, below, will go away soon */
                    528:        if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
                    529:                register int plen = 0;
                    530:                for (t = m; m; m = m->m_next)
                    531:                        plen += m->m_len;
                    532:                t->m_pkthdr.len = plen;
                    533:        }
                    534:        return ((struct ip *)ip);
                    535:
                    536: dropfrag:
                    537:        ipstat.ips_fragdropped++;
                    538:        m_freem(m);
                    539:        return (0);
                    540: }
                    541:
                    542: /*
                    543:  * Free a fragment reassembly header and all
                    544:  * associated datagrams.
                    545:  */
1.8       mycroft   546: void
1.1       cgd       547: ip_freef(fp)
                    548:        struct ipq *fp;
                    549: {
                    550:        register struct ipasfrag *q, *p;
                    551:
                    552:        for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = p) {
                    553:                p = q->ipf_next;
                    554:                ip_deq(q);
                    555:                m_freem(dtom(q));
                    556:        }
                    557:        remque(fp);
                    558:        (void) m_free(dtom(fp));
                    559: }
                    560:
                    561: /*
                    562:  * Put an ip fragment on a reassembly chain.
                    563:  * Like insque, but pointers in middle of structure.
                    564:  */
1.8       mycroft   565: void
1.1       cgd       566: ip_enq(p, prev)
                    567:        register struct ipasfrag *p, *prev;
                    568: {
                    569:
                    570:        p->ipf_prev = prev;
                    571:        p->ipf_next = prev->ipf_next;
                    572:        prev->ipf_next->ipf_prev = p;
                    573:        prev->ipf_next = p;
                    574: }
                    575:
                    576: /*
                    577:  * To ip_enq as remque is to insque.
                    578:  */
1.8       mycroft   579: void
1.1       cgd       580: ip_deq(p)
                    581:        register struct ipasfrag *p;
                    582: {
                    583:
                    584:        p->ipf_prev->ipf_next = p->ipf_next;
                    585:        p->ipf_next->ipf_prev = p->ipf_prev;
                    586: }
                    587:
                    588: /*
                    589:  * IP timer processing;
                    590:  * if a timer expires on a reassembly
                    591:  * queue, discard it.
                    592:  */
1.8       mycroft   593: void
1.1       cgd       594: ip_slowtimo()
                    595: {
                    596:        register struct ipq *fp;
                    597:        int s = splnet();
                    598:
                    599:        fp = ipq.next;
                    600:        if (fp == 0) {
                    601:                splx(s);
                    602:                return;
                    603:        }
                    604:        while (fp != &ipq) {
                    605:                --fp->ipq_ttl;
                    606:                fp = fp->next;
                    607:                if (fp->prev->ipq_ttl == 0) {
                    608:                        ipstat.ips_fragtimeout++;
                    609:                        ip_freef(fp->prev);
                    610:                }
                    611:        }
                    612:        splx(s);
                    613: }
                    614:
                    615: /*
                    616:  * Drain off all datagram fragments.
                    617:  */
1.8       mycroft   618: void
1.1       cgd       619: ip_drain()
                    620: {
                    621:
                    622:        while (ipq.next != &ipq) {
                    623:                ipstat.ips_fragdropped++;
                    624:                ip_freef(ipq.next);
                    625:        }
                    626: }
                    627:
                    628: /*
                    629:  * Do option processing on a datagram,
                    630:  * possibly discarding it if bad options are encountered,
                    631:  * or forwarding it if source-routed.
                    632:  * Returns 1 if packet has been forwarded/freed,
                    633:  * 0 if the packet should be processed further.
                    634:  */
1.8       mycroft   635: int
1.1       cgd       636: ip_dooptions(m)
                    637:        struct mbuf *m;
                    638: {
                    639:        register struct ip *ip = mtod(m, struct ip *);
                    640:        register u_char *cp;
                    641:        register struct ip_timestamp *ipt;
                    642:        register struct in_ifaddr *ia;
                    643:        int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13      mycroft   644:        struct in_addr *sin, dst;
1.1       cgd       645:        n_time ntime;
                    646:
1.13      mycroft   647:        dst = ip->ip_dst;
1.1       cgd       648:        cp = (u_char *)(ip + 1);
                    649:        cnt = (ip->ip_hl << 2) - sizeof (struct ip);
                    650:        for (; cnt > 0; cnt -= optlen, cp += optlen) {
                    651:                opt = cp[IPOPT_OPTVAL];
                    652:                if (opt == IPOPT_EOL)
                    653:                        break;
                    654:                if (opt == IPOPT_NOP)
                    655:                        optlen = 1;
                    656:                else {
                    657:                        optlen = cp[IPOPT_OLEN];
                    658:                        if (optlen <= 0 || optlen > cnt) {
                    659:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                    660:                                goto bad;
                    661:                        }
                    662:                }
                    663:                switch (opt) {
                    664:
                    665:                default:
                    666:                        break;
                    667:
                    668:                /*
                    669:                 * Source routing with record.
                    670:                 * Find interface with current destination address.
                    671:                 * If none on this machine then drop if strictly routed,
                    672:                 * or do nothing if loosely routed.
                    673:                 * Record interface address and bring up next address
                    674:                 * component.  If strictly routed make sure next
                    675:                 * address is on directly accessible net.
                    676:                 */
                    677:                case IPOPT_LSRR:
                    678:                case IPOPT_SSRR:
                    679:                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                    680:                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                    681:                                goto bad;
                    682:                        }
                    683:                        ipaddr.sin_addr = ip->ip_dst;
1.19      mycroft   684:                        ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1       cgd       685:                        if (ia == 0) {
                    686:                                if (opt == IPOPT_SSRR) {
                    687:                                        type = ICMP_UNREACH;
                    688:                                        code = ICMP_UNREACH_SRCFAIL;
                    689:                                        goto bad;
                    690:                                }
                    691:                                /*
                    692:                                 * Loose routing, and not at next destination
                    693:                                 * yet; nothing to do except forward.
                    694:                                 */
                    695:                                break;
                    696:                        }
                    697:                        off--;                  /* 0 origin */
                    698:                        if (off > optlen - sizeof(struct in_addr)) {
                    699:                                /*
                    700:                                 * End of source route.  Should be for us.
                    701:                                 */
                    702:                                save_rte(cp, ip->ip_src);
                    703:                                break;
                    704:                        }
                    705:                        /*
                    706:                         * locate outgoing interface
                    707:                         */
                    708:                        bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
                    709:                            sizeof(ipaddr.sin_addr));
                    710:                        if (opt == IPOPT_SSRR) {
                    711: #define        INA     struct in_ifaddr *
                    712: #define        SA      struct sockaddr *
                    713:                            if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
1.13      mycroft   714:                                ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1.1       cgd       715:                        } else
                    716:                                ia = ip_rtaddr(ipaddr.sin_addr);
                    717:                        if (ia == 0) {
                    718:                                type = ICMP_UNREACH;
                    719:                                code = ICMP_UNREACH_SRCFAIL;
                    720:                                goto bad;
                    721:                        }
                    722:                        ip->ip_dst = ipaddr.sin_addr;
1.20      mycroft   723:                        bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd       724:                            (caddr_t)(cp + off), sizeof(struct in_addr));
                    725:                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13      mycroft   726:                        /*
                    727:                         * Let ip_intr's mcast routing check handle mcast pkts
                    728:                         */
1.18      mycroft   729:                        forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1       cgd       730:                        break;
                    731:
                    732:                case IPOPT_RR:
                    733:                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                    734:                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                    735:                                goto bad;
                    736:                        }
                    737:                        /*
                    738:                         * If no space remains, ignore.
                    739:                         */
                    740:                        off--;                  /* 0 origin */
                    741:                        if (off > optlen - sizeof(struct in_addr))
                    742:                                break;
                    743:                        bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
                    744:                            sizeof(ipaddr.sin_addr));
                    745:                        /*
                    746:                         * locate outgoing interface; if we're the destination,
                    747:                         * use the incoming interface (should be same).
                    748:                         */
                    749:                        if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
                    750:                            (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
                    751:                                type = ICMP_UNREACH;
                    752:                                code = ICMP_UNREACH_HOST;
                    753:                                goto bad;
                    754:                        }
1.20      mycroft   755:                        bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd       756:                            (caddr_t)(cp + off), sizeof(struct in_addr));
                    757:                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
                    758:                        break;
                    759:
                    760:                case IPOPT_TS:
                    761:                        code = cp - (u_char *)ip;
                    762:                        ipt = (struct ip_timestamp *)cp;
                    763:                        if (ipt->ipt_len < 5)
                    764:                                goto bad;
1.15      cgd       765:                        if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1       cgd       766:                                if (++ipt->ipt_oflw == 0)
                    767:                                        goto bad;
                    768:                                break;
                    769:                        }
                    770:                        sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
                    771:                        switch (ipt->ipt_flg) {
                    772:
                    773:                        case IPOPT_TS_TSONLY:
                    774:                                break;
                    775:
                    776:                        case IPOPT_TS_TSANDADDR:
                    777:                                if (ipt->ipt_ptr + sizeof(n_time) +
                    778:                                    sizeof(struct in_addr) > ipt->ipt_len)
                    779:                                        goto bad;
1.13      mycroft   780:                                ipaddr.sin_addr = dst;
                    781:                                ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
                    782:                                                            m->m_pkthdr.rcvif);
                    783:                                if (ia == 0)
                    784:                                        continue;
1.20      mycroft   785:                                bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd       786:                                    (caddr_t)sin, sizeof(struct in_addr));
                    787:                                ipt->ipt_ptr += sizeof(struct in_addr);
                    788:                                break;
                    789:
                    790:                        case IPOPT_TS_PRESPEC:
                    791:                                if (ipt->ipt_ptr + sizeof(n_time) +
                    792:                                    sizeof(struct in_addr) > ipt->ipt_len)
                    793:                                        goto bad;
                    794:                                bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
                    795:                                    sizeof(struct in_addr));
                    796:                                if (ifa_ifwithaddr((SA)&ipaddr) == 0)
                    797:                                        continue;
                    798:                                ipt->ipt_ptr += sizeof(struct in_addr);
                    799:                                break;
                    800:
                    801:                        default:
                    802:                                goto bad;
                    803:                        }
                    804:                        ntime = iptime();
                    805:                        bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
                    806:                            sizeof(n_time));
                    807:                        ipt->ipt_ptr += sizeof(n_time);
                    808:                }
                    809:        }
                    810:        if (forward) {
                    811:                ip_forward(m, 1);
                    812:                return (1);
1.13      mycroft   813:        }
                    814:        return (0);
1.1       cgd       815: bad:
1.13      mycroft   816:        ip->ip_len -= ip->ip_hl << 2;   /* XXX icmp_error adds in hdr length */
                    817:        icmp_error(m, type, code, 0, 0);
                    818:        ipstat.ips_badoptions++;
1.1       cgd       819:        return (1);
                    820: }
                    821:
                    822: /*
                    823:  * Given address of next destination (final or next hop),
                    824:  * return internet address info of interface to be used to get there.
                    825:  */
                    826: struct in_ifaddr *
                    827: ip_rtaddr(dst)
                    828:         struct in_addr dst;
                    829: {
                    830:        register struct sockaddr_in *sin;
                    831:
1.19      mycroft   832:        sin = satosin(&ipforward_rt.ro_dst);
1.1       cgd       833:
                    834:        if (ipforward_rt.ro_rt == 0 || dst.s_addr != sin->sin_addr.s_addr) {
                    835:                if (ipforward_rt.ro_rt) {
                    836:                        RTFREE(ipforward_rt.ro_rt);
                    837:                        ipforward_rt.ro_rt = 0;
                    838:                }
                    839:                sin->sin_family = AF_INET;
                    840:                sin->sin_len = sizeof(*sin);
                    841:                sin->sin_addr = dst;
                    842:
                    843:                rtalloc(&ipforward_rt);
                    844:        }
                    845:        if (ipforward_rt.ro_rt == 0)
                    846:                return ((struct in_ifaddr *)0);
1.19      mycroft   847:        return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1       cgd       848: }
                    849:
                    850: /*
                    851:  * Save incoming source route for use in replies,
                    852:  * to be picked up later by ip_srcroute if the receiver is interested.
                    853:  */
1.13      mycroft   854: void
1.1       cgd       855: save_rte(option, dst)
                    856:        u_char *option;
                    857:        struct in_addr dst;
                    858: {
                    859:        unsigned olen;
                    860:
                    861:        olen = option[IPOPT_OLEN];
                    862: #ifdef DIAGNOSTIC
                    863:        if (ipprintfs)
                    864:                printf("save_rte: olen %d\n", olen);
                    865: #endif
                    866:        if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
                    867:                return;
                    868:        bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
                    869:        ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
                    870:        ip_srcrt.dst = dst;
                    871: }
                    872:
                    873: /*
                    874:  * Retrieve incoming source route for use in replies,
                    875:  * in the same form used by setsockopt.
                    876:  * The first hop is placed before the options, will be removed later.
                    877:  */
                    878: struct mbuf *
                    879: ip_srcroute()
                    880: {
                    881:        register struct in_addr *p, *q;
                    882:        register struct mbuf *m;
                    883:
                    884:        if (ip_nhops == 0)
                    885:                return ((struct mbuf *)0);
                    886:        m = m_get(M_DONTWAIT, MT_SOOPTS);
                    887:        if (m == 0)
                    888:                return ((struct mbuf *)0);
                    889:
1.13      mycroft   890: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1       cgd       891:
                    892:        /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
                    893:        m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
                    894:            OPTSIZ;
                    895: #ifdef DIAGNOSTIC
                    896:        if (ipprintfs)
                    897:                printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
                    898: #endif
                    899:
                    900:        /*
                    901:         * First save first hop for return route
                    902:         */
                    903:        p = &ip_srcrt.route[ip_nhops - 1];
                    904:        *(mtod(m, struct in_addr *)) = *p--;
                    905: #ifdef DIAGNOSTIC
                    906:        if (ipprintfs)
                    907:                printf(" hops %lx", ntohl(mtod(m, struct in_addr *)->s_addr));
                    908: #endif
                    909:
                    910:        /*
                    911:         * Copy option fields and padding (nop) to mbuf.
                    912:         */
                    913:        ip_srcrt.nop = IPOPT_NOP;
                    914:        ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
                    915:        bcopy((caddr_t)&ip_srcrt.nop,
                    916:            mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
                    917:        q = (struct in_addr *)(mtod(m, caddr_t) +
                    918:            sizeof(struct in_addr) + OPTSIZ);
                    919: #undef OPTSIZ
                    920:        /*
                    921:         * Record return path as an IP source route,
                    922:         * reversing the path (pointers are now aligned).
                    923:         */
                    924:        while (p >= ip_srcrt.route) {
                    925: #ifdef DIAGNOSTIC
                    926:                if (ipprintfs)
                    927:                        printf(" %lx", ntohl(q->s_addr));
                    928: #endif
                    929:                *q++ = *p--;
                    930:        }
                    931:        /*
                    932:         * Last hop goes to final destination.
                    933:         */
                    934:        *q = ip_srcrt.dst;
                    935: #ifdef DIAGNOSTIC
                    936:        if (ipprintfs)
                    937:                printf(" %lx\n", ntohl(q->s_addr));
                    938: #endif
                    939:        return (m);
                    940: }
                    941:
                    942: /*
                    943:  * Strip out IP options, at higher
                    944:  * level protocol in the kernel.
                    945:  * Second argument is buffer to which options
                    946:  * will be moved, and return value is their length.
                    947:  * XXX should be deleted; last arg currently ignored.
                    948:  */
1.8       mycroft   949: void
1.1       cgd       950: ip_stripoptions(m, mopt)
                    951:        register struct mbuf *m;
                    952:        struct mbuf *mopt;
                    953: {
                    954:        register int i;
                    955:        struct ip *ip = mtod(m, struct ip *);
                    956:        register caddr_t opts;
                    957:        int olen;
                    958:
                    959:        olen = (ip->ip_hl<<2) - sizeof (struct ip);
                    960:        opts = (caddr_t)(ip + 1);
                    961:        i = m->m_len - (sizeof (struct ip) + olen);
                    962:        bcopy(opts  + olen, opts, (unsigned)i);
                    963:        m->m_len -= olen;
                    964:        if (m->m_flags & M_PKTHDR)
                    965:                m->m_pkthdr.len -= olen;
                    966:        ip->ip_hl = sizeof(struct ip) >> 2;
                    967: }
                    968:
1.23    ! mycroft   969: int inetctlerrmap[PRC_NCMDS] = {
1.1       cgd       970:        0,              0,              0,              0,
                    971:        0,              EMSGSIZE,       EHOSTDOWN,      EHOSTUNREACH,
                    972:        EHOSTUNREACH,   EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
                    973:        EMSGSIZE,       EHOSTUNREACH,   0,              0,
                    974:        0,              0,              0,              0,
                    975:        ENOPROTOOPT
                    976: };
                    977:
                    978: /*
                    979:  * Forward a packet.  If some error occurs return the sender
                    980:  * an icmp packet.  Note we can't always generate a meaningful
                    981:  * icmp message because icmp doesn't have a large enough repertoire
                    982:  * of codes and types.
                    983:  *
                    984:  * If not forwarding, just drop the packet.  This could be confusing
                    985:  * if ipforwarding was zero but some routing protocol was advancing
                    986:  * us as a gateway to somewhere.  However, we must let the routing
                    987:  * protocol deal with that.
                    988:  *
                    989:  * The srcrt parameter indicates whether the packet is being forwarded
                    990:  * via a source route.
                    991:  */
1.13      mycroft   992: void
1.1       cgd       993: ip_forward(m, srcrt)
                    994:        struct mbuf *m;
                    995:        int srcrt;
                    996: {
                    997:        register struct ip *ip = mtod(m, struct ip *);
                    998:        register struct sockaddr_in *sin;
                    999:        register struct rtentry *rt;
                   1000:        int error, type = 0, code;
                   1001:        struct mbuf *mcopy;
1.13      mycroft  1002:        n_long dest;
                   1003:        struct ifnet *destifp;
1.1       cgd      1004:
1.13      mycroft  1005:        dest = 0;
1.1       cgd      1006: #ifdef DIAGNOSTIC
                   1007:        if (ipprintfs)
                   1008:                printf("forward: src %x dst %x ttl %x\n", ip->ip_src,
                   1009:                        ip->ip_dst, ip->ip_ttl);
                   1010: #endif
                   1011:        if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
                   1012:                ipstat.ips_cantforward++;
                   1013:                m_freem(m);
                   1014:                return;
                   1015:        }
                   1016:        HTONS(ip->ip_id);
                   1017:        if (ip->ip_ttl <= IPTTLDEC) {
1.13      mycroft  1018:                icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1       cgd      1019:                return;
                   1020:        }
                   1021:        ip->ip_ttl -= IPTTLDEC;
                   1022:
1.19      mycroft  1023:        sin = satosin(&ipforward_rt.ro_dst);
1.1       cgd      1024:        if ((rt = ipforward_rt.ro_rt) == 0 ||
                   1025:            ip->ip_dst.s_addr != sin->sin_addr.s_addr) {
                   1026:                if (ipforward_rt.ro_rt) {
                   1027:                        RTFREE(ipforward_rt.ro_rt);
                   1028:                        ipforward_rt.ro_rt = 0;
                   1029:                }
                   1030:                sin->sin_family = AF_INET;
                   1031:                sin->sin_len = sizeof(*sin);
                   1032:                sin->sin_addr = ip->ip_dst;
                   1033:
                   1034:                rtalloc(&ipforward_rt);
                   1035:                if (ipforward_rt.ro_rt == 0) {
1.13      mycroft  1036:                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1       cgd      1037:                        return;
                   1038:                }
                   1039:                rt = ipforward_rt.ro_rt;
                   1040:        }
                   1041:
                   1042:        /*
                   1043:         * Save at most 64 bytes of the packet in case
                   1044:         * we need to generate an ICMP message to the src.
                   1045:         */
                   1046:        mcopy = m_copy(m, 0, imin((int)ip->ip_len, 64));
                   1047:
                   1048:        /*
                   1049:         * If forwarding packet using same interface that it came in on,
                   1050:         * perhaps should send a redirect to sender to shortcut a hop.
                   1051:         * Only send redirect if source is sending directly to us,
                   1052:         * and if packet was not source routed (or has any options).
                   1053:         * Also, don't send redirect if forwarding using a default route
                   1054:         * or a route modified by a redirect.
                   1055:         */
                   1056:        if (rt->rt_ifp == m->m_pkthdr.rcvif &&
                   1057:            (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
                   1058:            satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
                   1059:            ipsendredirects && !srcrt) {
1.19      mycroft  1060:                if (rt->rt_ifa &&
                   1061:                    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
                   1062:                    ifatoia(rt->rt_ifa)->ia_subnet) {
1.1       cgd      1063:                    if (rt->rt_flags & RTF_GATEWAY)
1.13      mycroft  1064:                        dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1.1       cgd      1065:                    else
1.13      mycroft  1066:                        dest = ip->ip_dst.s_addr;
                   1067:                    /* Router requirements says to only send host redirects */
1.1       cgd      1068:                    type = ICMP_REDIRECT;
1.13      mycroft  1069:                    code = ICMP_REDIRECT_HOST;
1.1       cgd      1070: #ifdef DIAGNOSTIC
                   1071:                    if (ipprintfs)
1.15      cgd      1072:                        printf("redirect (%d) to %lx\n", code, (u_int32_t)dest);
1.1       cgd      1073: #endif
                   1074:                }
                   1075:        }
                   1076:
1.13      mycroft  1077:        error = ip_output(m, (struct mbuf *)0, &ipforward_rt, IP_FORWARDING
1.9       mycroft  1078: #ifdef DIRECTED_BROADCAST
1.13      mycroft  1079:                            | IP_ALLOWBROADCAST
1.9       mycroft  1080: #endif
1.13      mycroft  1081:                                                , 0);
1.1       cgd      1082:        if (error)
                   1083:                ipstat.ips_cantforward++;
                   1084:        else {
                   1085:                ipstat.ips_forward++;
                   1086:                if (type)
                   1087:                        ipstat.ips_redirectsent++;
                   1088:                else {
                   1089:                        if (mcopy)
                   1090:                                m_freem(mcopy);
                   1091:                        return;
                   1092:                }
                   1093:        }
                   1094:        if (mcopy == NULL)
                   1095:                return;
1.13      mycroft  1096:        destifp = NULL;
                   1097:
1.1       cgd      1098:        switch (error) {
                   1099:
                   1100:        case 0:                         /* forwarded, but need redirect */
                   1101:                /* type, code set above */
                   1102:                break;
                   1103:
                   1104:        case ENETUNREACH:               /* shouldn't happen, checked above */
                   1105:        case EHOSTUNREACH:
                   1106:        case ENETDOWN:
                   1107:        case EHOSTDOWN:
                   1108:        default:
                   1109:                type = ICMP_UNREACH;
                   1110:                code = ICMP_UNREACH_HOST;
                   1111:                break;
                   1112:
                   1113:        case EMSGSIZE:
                   1114:                type = ICMP_UNREACH;
                   1115:                code = ICMP_UNREACH_NEEDFRAG;
1.13      mycroft  1116:                if (ipforward_rt.ro_rt)
                   1117:                        destifp = ipforward_rt.ro_rt->rt_ifp;
1.1       cgd      1118:                ipstat.ips_cantfrag++;
                   1119:                break;
                   1120:
                   1121:        case ENOBUFS:
                   1122:                type = ICMP_SOURCEQUENCH;
                   1123:                code = 0;
                   1124:                break;
                   1125:        }
1.13      mycroft  1126:        icmp_error(mcopy, type, code, dest, destifp);
                   1127: }
                   1128:
                   1129: int
                   1130: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
                   1131:        int *name;
                   1132:        u_int namelen;
                   1133:        void *oldp;
                   1134:        size_t *oldlenp;
                   1135:        void *newp;
                   1136:        size_t newlen;
                   1137: {
                   1138:        /* All sysctl names at this level are terminal. */
                   1139:        if (namelen != 1)
                   1140:                return (ENOTDIR);
                   1141:
                   1142:        switch (name[0]) {
                   1143:        case IPCTL_FORWARDING:
                   1144:                return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
                   1145:        case IPCTL_SENDREDIRECTS:
                   1146:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1147:                        &ipsendredirects));
                   1148:        case IPCTL_DEFTTL:
                   1149:                return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
                   1150: #ifdef notyet
                   1151:        case IPCTL_DEFMTU:
                   1152:                return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
                   1153: #endif
                   1154:        default:
                   1155:                return (EOPNOTSUPP);
                   1156:        }
                   1157:        /* NOTREACHED */
1.1       cgd      1158: }

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