[BACK]Return to ip_input.c CVS log [TXT][DIR] Up to [cvs.NetBSD.org] / src / sys / netinet

Annotation of src/sys/netinet/ip_input.c, Revision 1.61

1.61    ! kml         1: /*     $NetBSD: ip_input.c,v 1.60 1998/04/29 03:44:11 kml Exp $        */
1.58      tls         2:
                      3: /*-
                      4:  * Copyright (c) 1998 The NetBSD Foundation, Inc.
                      5:  * All rights reserved.
                      6:  *
                      7:  * This code is derived from software contributed to The NetBSD Foundation
                      8:  * by Public Access Networks Corporation ("Panix").  It was developed under
                      9:  * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
                     10:  *
                     11:  * Redistribution and use in source and binary forms, with or without
                     12:  * modification, are permitted provided that the following conditions
                     13:  * are met:
                     14:  * 1. Redistributions of source code must retain the above copyright
                     15:  *    notice, this list of conditions and the following disclaimer.
                     16:  * 2. Redistributions in binary form must reproduce the above copyright
                     17:  *    notice, this list of conditions and the following disclaimer in the
                     18:  *    documentation and/or other materials provided with the distribution.
                     19:  * 3. All advertising materials mentioning features or use of this software
                     20:  *    must display the following acknowledgement:
                     21:  *     This product includes software developed by the NetBSD
                     22:  *     Foundation, Inc. and its contributors.
                     23:  * 4. Neither the name of The NetBSD Foundation nor the names of its
                     24:  *    contributors may be used to endorse or promote products derived
                     25:  *    from this software without specific prior written permission.
                     26:  *
                     27:  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
                     28:  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
                     29:  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
                     30:  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
                     31:  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
                     32:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
                     33:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
                     34:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
                     35:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
                     36:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
                     37:  * POSSIBILITY OF SUCH DAMAGE.
                     38:  */
1.14      cgd        39:
1.1       cgd        40: /*
1.13      mycroft    41:  * Copyright (c) 1982, 1986, 1988, 1993
                     42:  *     The Regents of the University of California.  All rights reserved.
1.1       cgd        43:  *
                     44:  * Redistribution and use in source and binary forms, with or without
                     45:  * modification, are permitted provided that the following conditions
                     46:  * are met:
                     47:  * 1. Redistributions of source code must retain the above copyright
                     48:  *    notice, this list of conditions and the following disclaimer.
                     49:  * 2. Redistributions in binary form must reproduce the above copyright
                     50:  *    notice, this list of conditions and the following disclaimer in the
                     51:  *    documentation and/or other materials provided with the distribution.
                     52:  * 3. All advertising materials mentioning features or use of this software
                     53:  *    must display the following acknowledgement:
                     54:  *     This product includes software developed by the University of
                     55:  *     California, Berkeley and its contributors.
                     56:  * 4. Neither the name of the University nor the names of its contributors
                     57:  *    may be used to endorse or promote products derived from this software
                     58:  *    without specific prior written permission.
                     59:  *
                     60:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     61:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     62:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     63:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     64:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     65:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     66:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     67:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     68:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     69:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     70:  * SUCH DAMAGE.
                     71:  *
1.14      cgd        72:  *     @(#)ip_input.c  8.2 (Berkeley) 1/4/94
1.1       cgd        73:  */
1.55      scottr     74:
                     75: #include "opt_mrouting.h"
1.1       cgd        76:
1.5       mycroft    77: #include <sys/param.h>
                     78: #include <sys/systm.h>
                     79: #include <sys/malloc.h>
                     80: #include <sys/mbuf.h>
                     81: #include <sys/domain.h>
                     82: #include <sys/protosw.h>
                     83: #include <sys/socket.h>
1.44      thorpej    84: #include <sys/socketvar.h>
1.5       mycroft    85: #include <sys/errno.h>
                     86: #include <sys/time.h>
                     87: #include <sys/kernel.h>
1.28      christos   88: #include <sys/proc.h>
                     89:
                     90: #include <vm/vm.h>
                     91: #include <sys/sysctl.h>
1.1       cgd        92:
1.5       mycroft    93: #include <net/if.h>
1.44      thorpej    94: #include <net/if_dl.h>
1.5       mycroft    95: #include <net/route.h>
1.45      mrg        96: #include <net/pfil.h>
1.1       cgd        97:
1.5       mycroft    98: #include <netinet/in.h>
                     99: #include <netinet/in_systm.h>
                    100: #include <netinet/ip.h>
                    101: #include <netinet/in_pcb.h>
                    102: #include <netinet/in_var.h>
                    103: #include <netinet/ip_var.h>
                    104: #include <netinet/ip_icmp.h>
1.44      thorpej   105:
1.1       cgd       106: #ifndef        IPFORWARDING
                    107: #ifdef GATEWAY
                    108: #define        IPFORWARDING    1       /* forward IP packets not for us */
                    109: #else /* GATEWAY */
                    110: #define        IPFORWARDING    0       /* don't forward IP packets not for us */
                    111: #endif /* GATEWAY */
                    112: #endif /* IPFORWARDING */
                    113: #ifndef        IPSENDREDIRECTS
                    114: #define        IPSENDREDIRECTS 1
                    115: #endif
1.26      thorpej   116: #ifndef IPFORWSRCRT
1.47      cjs       117: #define        IPFORWSRCRT     1       /* forward source-routed packets */
                    118: #endif
                    119: #ifndef IPALLOWSRCRT
1.48      mrg       120: #define        IPALLOWSRCRT    1       /* allow source-routed packets */
1.26      thorpej   121: #endif
1.53      kml       122: #ifndef IPMTUDISC
                    123: #define IPMTUDISC      0
                    124: #endif
1.60      kml       125: #ifndef IPMTUDISCTIMEOUT
1.61    ! kml       126: #define IPMTUDISCTIMEOUT (10 * 60)     /* as per RFC 1191 */
1.60      kml       127: #endif
1.53      kml       128:
1.27      thorpej   129: /*
                    130:  * Note: DIRECTED_BROADCAST is handled this way so that previous
                    131:  * configuration using this option will Just Work.
                    132:  */
                    133: #ifndef IPDIRECTEDBCAST
                    134: #ifdef DIRECTED_BROADCAST
                    135: #define IPDIRECTEDBCAST        1
                    136: #else
                    137: #define        IPDIRECTEDBCAST 0
                    138: #endif /* DIRECTED_BROADCAST */
                    139: #endif /* IPDIRECTEDBCAST */
1.1       cgd       140: int    ipforwarding = IPFORWARDING;
                    141: int    ipsendredirects = IPSENDREDIRECTS;
1.13      mycroft   142: int    ip_defttl = IPDEFTTL;
1.26      thorpej   143: int    ip_forwsrcrt = IPFORWSRCRT;
1.27      thorpej   144: int    ip_directedbcast = IPDIRECTEDBCAST;
1.47      cjs       145: int    ip_allowsrcrt = IPALLOWSRCRT;
1.53      kml       146: int    ip_mtudisc = IPMTUDISC;
1.60      kml       147: u_int  ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1       cgd       148: #ifdef DIAGNOSTIC
                    149: int    ipprintfs = 0;
                    150: #endif
                    151:
1.60      kml       152: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
                    153:
1.1       cgd       154: extern struct domain inetdomain;
                    155: extern struct protosw inetsw[];
                    156: u_char ip_protox[IPPROTO_MAX];
                    157: int    ipqmaxlen = IFQ_MAXLEN;
1.22      mycroft   158: struct in_ifaddrhead in_ifaddr;
1.57      tls       159: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.13      mycroft   160: struct ifqueue ipintrq;
1.1       cgd       161:
                    162: /*
                    163:  * We need to save the IP options in case a protocol wants to respond
                    164:  * to an incoming packet over the same route if the packet got here
                    165:  * using IP source routing.  This allows connection establishment and
                    166:  * maintenance when the remote end is on a network that is not known
                    167:  * to us.
                    168:  */
                    169: int    ip_nhops = 0;
                    170: static struct ip_srcrt {
                    171:        struct  in_addr dst;                    /* final destination */
                    172:        char    nop;                            /* one NOP to align */
                    173:        char    srcopt[IPOPT_OFFSET + 1];       /* OPTVAL, OLEN and OFFSET */
                    174:        struct  in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
                    175: } ip_srcrt;
                    176:
1.13      mycroft   177: static void save_rte __P((u_char *, struct in_addr));
1.35      mycroft   178:
1.1       cgd       179: /*
                    180:  * IP initialization: fill in IP protocol switch table.
                    181:  * All protocols not implemented in kernel go to raw IP protocol handler.
                    182:  */
1.8       mycroft   183: void
1.1       cgd       184: ip_init()
                    185: {
                    186:        register struct protosw *pr;
                    187:        register int i;
                    188:
                    189:        pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
                    190:        if (pr == 0)
                    191:                panic("ip_init");
                    192:        for (i = 0; i < IPPROTO_MAX; i++)
                    193:                ip_protox[i] = pr - inetsw;
                    194:        for (pr = inetdomain.dom_protosw;
                    195:            pr < inetdomain.dom_protoswNPROTOSW; pr++)
                    196:                if (pr->pr_domain->dom_family == PF_INET &&
                    197:                    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
                    198:                        ip_protox[pr->pr_protocol] = pr - inetsw;
1.25      cgd       199:        LIST_INIT(&ipq);
1.1       cgd       200:        ip_id = time.tv_sec & 0xffff;
                    201:        ipintrq.ifq_maxlen = ipqmaxlen;
1.22      mycroft   202:        TAILQ_INIT(&in_ifaddr);
1.57      tls       203:        in_ifaddrhashtbl =
                    204:            hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash);
1.60      kml       205:        if (ip_mtudisc != 0)
                    206:                ip_mtudisc_timeout_q =
                    207:                    rt_timer_queue_create(ip_mtudisc_timeout);
1.1       cgd       208: }
                    209:
                    210: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
                    211: struct route ipforward_rt;
                    212:
                    213: /*
                    214:  * Ip input routine.  Checksum and byte swap header.  If fragmented
                    215:  * try to reassemble.  Process options.  Pass to next level.
                    216:  */
1.8       mycroft   217: void
1.1       cgd       218: ipintr()
                    219: {
1.33      mrg       220:        register struct ip *ip = NULL;
1.1       cgd       221:        register struct mbuf *m;
                    222:        register struct ipq *fp;
                    223:        register struct in_ifaddr *ia;
1.57      tls       224:        register struct ifaddr *ifa;
1.25      cgd       225:        struct ipqent *ipqe;
1.35      mycroft   226:        int hlen = 0, mff, len, s;
1.36      mrg       227: #ifdef PFIL_HOOKS
1.33      mrg       228:        struct packet_filter_hook *pfh;
                    229:        struct mbuf *m0;
1.43      mrg       230:        int rv;
1.36      mrg       231: #endif /* PFIL_HOOKS */
1.1       cgd       232:
                    233: next:
                    234:        /*
                    235:         * Get next datagram off input queue and get IP header
                    236:         * in first mbuf.
                    237:         */
                    238:        s = splimp();
                    239:        IF_DEQUEUE(&ipintrq, m);
                    240:        splx(s);
1.13      mycroft   241:        if (m == 0)
1.1       cgd       242:                return;
                    243: #ifdef DIAGNOSTIC
                    244:        if ((m->m_flags & M_PKTHDR) == 0)
                    245:                panic("ipintr no HDR");
                    246: #endif
                    247:        /*
                    248:         * If no IP addresses have been set yet but the interfaces
                    249:         * are receiving, can't do anything with incoming packets yet.
                    250:         */
1.22      mycroft   251:        if (in_ifaddr.tqh_first == 0)
1.1       cgd       252:                goto bad;
                    253:        ipstat.ips_total++;
                    254:        if (m->m_len < sizeof (struct ip) &&
                    255:            (m = m_pullup(m, sizeof (struct ip))) == 0) {
                    256:                ipstat.ips_toosmall++;
                    257:                goto next;
                    258:        }
                    259:        ip = mtod(m, struct ip *);
1.13      mycroft   260:        if (ip->ip_v != IPVERSION) {
                    261:                ipstat.ips_badvers++;
                    262:                goto bad;
                    263:        }
1.1       cgd       264:        hlen = ip->ip_hl << 2;
                    265:        if (hlen < sizeof(struct ip)) { /* minimum header length */
                    266:                ipstat.ips_badhlen++;
                    267:                goto bad;
                    268:        }
                    269:        if (hlen > m->m_len) {
                    270:                if ((m = m_pullup(m, hlen)) == 0) {
                    271:                        ipstat.ips_badhlen++;
                    272:                        goto next;
                    273:                }
                    274:                ip = mtod(m, struct ip *);
                    275:        }
1.28      christos  276:        if ((ip->ip_sum = in_cksum(m, hlen)) != 0) {
1.1       cgd       277:                ipstat.ips_badsum++;
                    278:                goto bad;
                    279:        }
                    280:
                    281:        /*
                    282:         * Convert fields to host representation.
                    283:         */
                    284:        NTOHS(ip->ip_len);
                    285:        NTOHS(ip->ip_id);
                    286:        NTOHS(ip->ip_off);
1.35      mycroft   287:        len = ip->ip_len;
1.1       cgd       288:
                    289:        /*
                    290:         * Check that the amount of data in the buffers
                    291:         * is as at least much as the IP header would have us expect.
                    292:         * Trim mbufs if longer than we expect.
                    293:         * Drop packet if shorter than we expect.
                    294:         */
1.35      mycroft   295:        if (m->m_pkthdr.len < len) {
1.1       cgd       296:                ipstat.ips_tooshort++;
                    297:                goto bad;
                    298:        }
1.35      mycroft   299:        if (m->m_pkthdr.len > len) {
1.1       cgd       300:                if (m->m_len == m->m_pkthdr.len) {
1.35      mycroft   301:                        m->m_len = len;
                    302:                        m->m_pkthdr.len = len;
1.1       cgd       303:                } else
1.35      mycroft   304:                        m_adj(m, len - m->m_pkthdr.len);
1.1       cgd       305:        }
                    306:
1.36      mrg       307: #ifdef PFIL_HOOKS
1.33      mrg       308:        /*
                    309:         * Run through list of hooks for input packets.
                    310:         */
                    311:        m0 = m;
1.59      mrg       312:        for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
1.33      mrg       313:                if (pfh->pfil_func) {
1.43      mrg       314:                        rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
                    315:                        if (rv)
1.40      veego     316:                                goto next;
1.49      christos  317:                        ip = mtod(m = m0, struct ip *);
1.33      mrg       318:                }
1.36      mrg       319: #endif /* PFIL_HOOKS */
1.33      mrg       320:
1.1       cgd       321:        /*
                    322:         * Process options and, if not destined for us,
                    323:         * ship it on.  ip_dooptions returns 1 when an
                    324:         * error was detected (causing an icmp message
                    325:         * to be sent and the original packet to be freed).
                    326:         */
                    327:        ip_nhops = 0;           /* for source routed packets */
                    328:        if (hlen > sizeof (struct ip) && ip_dooptions(m))
                    329:                goto next;
                    330:
                    331:        /*
                    332:         * Check our list of addresses, to see if the packet is for us.
                    333:         */
1.57      tls       334:        INADDR_TO_IA(ip->ip_dst, ia);
                    335:        if (ia != NULL) goto ours;
                    336:        if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
                    337:                for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
                    338:                    ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
                    339:                        if (ifa->ifa_addr->sa_family != AF_INET) continue;
                    340:                        ia = ifatoia(ifa);
1.35      mycroft   341:                        if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
                    342:                            in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20      mycroft   343:                            /*
                    344:                             * Look for all-0's host part (old broadcast addr),
                    345:                             * either for subnet or net.
                    346:                             */
                    347:                            ip->ip_dst.s_addr == ia->ia_subnet ||
1.18      mycroft   348:                            ip->ip_dst.s_addr == ia->ia_net)
1.1       cgd       349:                                goto ours;
1.57      tls       350:                        /*
                    351:                         * An interface with IP address zero accepts
                    352:                         * all packets that arrive on that interface.
                    353:                         */
                    354:                        if (in_nullhost(ia->ia_addr.sin_addr))
                    355:                                goto ours;
1.1       cgd       356:                }
                    357:        }
1.18      mycroft   358:        if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4       hpeyerl   359:                struct in_multi *inm;
                    360: #ifdef MROUTING
                    361:                extern struct socket *ip_mrouter;
1.10      brezak    362:
                    363:                if (m->m_flags & M_EXT) {
                    364:                        if ((m = m_pullup(m, hlen)) == 0) {
                    365:                                ipstat.ips_toosmall++;
                    366:                                goto next;
                    367:                        }
                    368:                        ip = mtod(m, struct ip *);
                    369:                }
1.4       hpeyerl   370:
                    371:                if (ip_mrouter) {
                    372:                        /*
                    373:                         * If we are acting as a multicast router, all
                    374:                         * incoming multicast packets are passed to the
                    375:                         * kernel-level multicast forwarding function.
                    376:                         * The packet is returned (relatively) intact; if
                    377:                         * ip_mforward() returns a non-zero value, the packet
                    378:                         * must be discarded, else it may be accepted below.
                    379:                         *
                    380:                         * (The IP ident field is put in the same byte order
                    381:                         * as expected when ip_mforward() is called from
                    382:                         * ip_output().)
                    383:                         */
                    384:                        ip->ip_id = htons(ip->ip_id);
1.13      mycroft   385:                        if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
                    386:                                ipstat.ips_cantforward++;
1.4       hpeyerl   387:                                m_freem(m);
                    388:                                goto next;
                    389:                        }
                    390:                        ip->ip_id = ntohs(ip->ip_id);
                    391:
                    392:                        /*
                    393:                         * The process-level routing demon needs to receive
                    394:                         * all multicast IGMP packets, whether or not this
                    395:                         * host belongs to their destination groups.
                    396:                         */
                    397:                        if (ip->ip_p == IPPROTO_IGMP)
                    398:                                goto ours;
1.13      mycroft   399:                        ipstat.ips_forward++;
1.4       hpeyerl   400:                }
                    401: #endif
                    402:                /*
                    403:                 * See if we belong to the destination multicast group on the
                    404:                 * arrival interface.
                    405:                 */
                    406:                IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
                    407:                if (inm == NULL) {
1.13      mycroft   408:                        ipstat.ips_cantforward++;
1.4       hpeyerl   409:                        m_freem(m);
                    410:                        goto next;
                    411:                }
                    412:                goto ours;
                    413:        }
1.19      mycroft   414:        if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35      mycroft   415:            in_nullhost(ip->ip_dst))
1.1       cgd       416:                goto ours;
                    417:
                    418:        /*
                    419:         * Not for us; forward if possible and desirable.
                    420:         */
                    421:        if (ipforwarding == 0) {
                    422:                ipstat.ips_cantforward++;
                    423:                m_freem(m);
                    424:        } else
                    425:                ip_forward(m, 0);
                    426:        goto next;
                    427:
                    428: ours:
                    429:        /*
                    430:         * If offset or IP_MF are set, must reassemble.
                    431:         * Otherwise, nothing need be done.
                    432:         * (We could look in the reassembly queue to see
                    433:         * if the packet was previously fragmented,
                    434:         * but it's not worth the time; just let them time out.)
                    435:         */
1.37      perry     436:        if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1       cgd       437:                /*
                    438:                 * Look for queue of fragments
                    439:                 * of this datagram.
                    440:                 */
1.25      cgd       441:                for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1       cgd       442:                        if (ip->ip_id == fp->ipq_id &&
1.35      mycroft   443:                            in_hosteq(ip->ip_src, fp->ipq_src) &&
                    444:                            in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1       cgd       445:                            ip->ip_p == fp->ipq_p)
                    446:                                goto found;
                    447:                fp = 0;
                    448: found:
                    449:
                    450:                /*
                    451:                 * Adjust ip_len to not reflect header,
1.25      cgd       452:                 * set ipqe_mff if more fragments are expected,
1.1       cgd       453:                 * convert offset of this to bytes.
                    454:                 */
                    455:                ip->ip_len -= hlen;
1.25      cgd       456:                mff = (ip->ip_off & IP_MF) != 0;
                    457:                if (mff) {
1.16      cgd       458:                        /*
                    459:                         * Make sure that fragments have a data length
                    460:                         * that's a non-zero multiple of 8 bytes.
                    461:                         */
1.17      cgd       462:                        if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16      cgd       463:                                ipstat.ips_badfrags++;
                    464:                                goto bad;
                    465:                        }
                    466:                }
1.1       cgd       467:                ip->ip_off <<= 3;
                    468:
                    469:                /*
                    470:                 * If datagram marked as having more fragments
                    471:                 * or if this is not the first fragment,
                    472:                 * attempt reassembly; if it succeeds, proceed.
                    473:                 */
1.25      cgd       474:                if (mff || ip->ip_off) {
1.1       cgd       475:                        ipstat.ips_fragments++;
1.25      cgd       476:                        MALLOC(ipqe, struct ipqent *, sizeof (struct ipqent),
                    477:                            M_IPQ, M_NOWAIT);
                    478:                        if (ipqe == NULL) {
                    479:                                ipstat.ips_rcvmemdrop++;
                    480:                                goto bad;
                    481:                        }
                    482:                        ipqe->ipqe_mff = mff;
1.50      thorpej   483:                        ipqe->ipqe_m = m;
1.25      cgd       484:                        ipqe->ipqe_ip = ip;
1.50      thorpej   485:                        m = ip_reass(ipqe, fp);
                    486:                        if (m == 0)
1.1       cgd       487:                                goto next;
1.13      mycroft   488:                        ipstat.ips_reassembled++;
1.50      thorpej   489:                        ip = mtod(m, struct ip *);
1.1       cgd       490:                } else
                    491:                        if (fp)
                    492:                                ip_freef(fp);
                    493:        } else
                    494:                ip->ip_len -= hlen;
                    495:
                    496:        /*
                    497:         * Switch out to protocol's input routine.
                    498:         */
                    499:        ipstat.ips_delivered++;
                    500:        (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
                    501:        goto next;
                    502: bad:
                    503:        m_freem(m);
                    504:        goto next;
                    505: }
                    506:
                    507: /*
                    508:  * Take incoming datagram fragment and try to
                    509:  * reassemble it into whole datagram.  If a chain for
                    510:  * reassembly of this datagram already exists, then it
                    511:  * is given as fp; otherwise have to make a chain.
                    512:  */
1.50      thorpej   513: struct mbuf *
1.25      cgd       514: ip_reass(ipqe, fp)
                    515:        register struct ipqent *ipqe;
1.1       cgd       516:        register struct ipq *fp;
                    517: {
1.50      thorpej   518:        register struct mbuf *m = ipqe->ipqe_m;
1.25      cgd       519:        register struct ipqent *nq, *p, *q;
                    520:        struct ip *ip;
1.1       cgd       521:        struct mbuf *t;
1.25      cgd       522:        int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1       cgd       523:        int i, next;
                    524:
                    525:        /*
                    526:         * Presence of header sizes in mbufs
                    527:         * would confuse code below.
                    528:         */
                    529:        m->m_data += hlen;
                    530:        m->m_len -= hlen;
                    531:
                    532:        /*
                    533:         * If first fragment to arrive, create a reassembly queue.
                    534:         */
                    535:        if (fp == 0) {
1.50      thorpej   536:                MALLOC(fp, struct ipq *, sizeof (struct ipq),
                    537:                    M_FTABLE, M_NOWAIT);
                    538:                if (fp == NULL)
1.1       cgd       539:                        goto dropfrag;
1.25      cgd       540:                LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1       cgd       541:                fp->ipq_ttl = IPFRAGTTL;
1.25      cgd       542:                fp->ipq_p = ipqe->ipqe_ip->ip_p;
                    543:                fp->ipq_id = ipqe->ipqe_ip->ip_id;
                    544:                LIST_INIT(&fp->ipq_fragq);
                    545:                fp->ipq_src = ipqe->ipqe_ip->ip_src;
                    546:                fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
                    547:                p = NULL;
1.1       cgd       548:                goto insert;
                    549:        }
                    550:
                    551:        /*
                    552:         * Find a segment which begins after this one does.
                    553:         */
1.25      cgd       554:        for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
                    555:            p = q, q = q->ipqe_q.le_next)
                    556:                if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1       cgd       557:                        break;
                    558:
                    559:        /*
                    560:         * If there is a preceding segment, it may provide some of
                    561:         * our data already.  If so, drop the data from the incoming
                    562:         * segment.  If it provides all of our data, drop us.
                    563:         */
1.25      cgd       564:        if (p != NULL) {
                    565:                i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
                    566:                    ipqe->ipqe_ip->ip_off;
1.1       cgd       567:                if (i > 0) {
1.25      cgd       568:                        if (i >= ipqe->ipqe_ip->ip_len)
1.1       cgd       569:                                goto dropfrag;
1.50      thorpej   570:                        m_adj(ipqe->ipqe_m, i);
1.25      cgd       571:                        ipqe->ipqe_ip->ip_off += i;
                    572:                        ipqe->ipqe_ip->ip_len -= i;
1.1       cgd       573:                }
                    574:        }
                    575:
                    576:        /*
                    577:         * While we overlap succeeding segments trim them or,
                    578:         * if they are completely covered, dequeue them.
                    579:         */
1.25      cgd       580:        for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
                    581:            q->ipqe_ip->ip_off; q = nq) {
                    582:                i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
                    583:                    q->ipqe_ip->ip_off;
                    584:                if (i < q->ipqe_ip->ip_len) {
                    585:                        q->ipqe_ip->ip_len -= i;
                    586:                        q->ipqe_ip->ip_off += i;
1.50      thorpej   587:                        m_adj(q->ipqe_m, i);
1.1       cgd       588:                        break;
                    589:                }
1.25      cgd       590:                nq = q->ipqe_q.le_next;
1.50      thorpej   591:                m_freem(q->ipqe_m);
1.25      cgd       592:                LIST_REMOVE(q, ipqe_q);
                    593:                FREE(q, M_IPQ);
1.1       cgd       594:        }
                    595:
                    596: insert:
                    597:        /*
                    598:         * Stick new segment in its place;
                    599:         * check for complete reassembly.
                    600:         */
1.25      cgd       601:        if (p == NULL) {
                    602:                LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
                    603:        } else {
                    604:                LIST_INSERT_AFTER(p, ipqe, ipqe_q);
                    605:        }
1.1       cgd       606:        next = 0;
1.25      cgd       607:        for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
                    608:            p = q, q = q->ipqe_q.le_next) {
                    609:                if (q->ipqe_ip->ip_off != next)
1.1       cgd       610:                        return (0);
1.25      cgd       611:                next += q->ipqe_ip->ip_len;
1.1       cgd       612:        }
1.25      cgd       613:        if (p->ipqe_mff)
1.1       cgd       614:                return (0);
                    615:
                    616:        /*
1.41      thorpej   617:         * Reassembly is complete.  Check for a bogus message size and
                    618:         * concatenate fragments.
1.1       cgd       619:         */
1.25      cgd       620:        q = fp->ipq_fragq.lh_first;
                    621:        ip = q->ipqe_ip;
1.41      thorpej   622:        if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
                    623:                ipstat.ips_toolong++;
                    624:                ip_freef(fp);
                    625:                return (0);
                    626:        }
1.50      thorpej   627:        m = q->ipqe_m;
1.1       cgd       628:        t = m->m_next;
                    629:        m->m_next = 0;
                    630:        m_cat(m, t);
1.25      cgd       631:        nq = q->ipqe_q.le_next;
                    632:        FREE(q, M_IPQ);
                    633:        for (q = nq; q != NULL; q = nq) {
1.50      thorpej   634:                t = q->ipqe_m;
1.25      cgd       635:                nq = q->ipqe_q.le_next;
                    636:                FREE(q, M_IPQ);
1.1       cgd       637:                m_cat(m, t);
                    638:        }
                    639:
                    640:        /*
                    641:         * Create header for new ip packet by
                    642:         * modifying header of first packet;
                    643:         * dequeue and discard fragment reassembly header.
                    644:         * Make header visible.
                    645:         */
                    646:        ip->ip_len = next;
1.25      cgd       647:        ip->ip_src = fp->ipq_src;
                    648:        ip->ip_dst = fp->ipq_dst;
                    649:        LIST_REMOVE(fp, ipq_q);
1.50      thorpej   650:        FREE(fp, M_FTABLE);
1.1       cgd       651:        m->m_len += (ip->ip_hl << 2);
                    652:        m->m_data -= (ip->ip_hl << 2);
                    653:        /* some debugging cruft by sklower, below, will go away soon */
                    654:        if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
                    655:                register int plen = 0;
1.50      thorpej   656:                for (t = m; t; t = t->m_next)
                    657:                        plen += t->m_len;
                    658:                m->m_pkthdr.len = plen;
1.1       cgd       659:        }
1.50      thorpej   660:        return (m);
1.1       cgd       661:
                    662: dropfrag:
                    663:        ipstat.ips_fragdropped++;
                    664:        m_freem(m);
1.25      cgd       665:        FREE(ipqe, M_IPQ);
1.1       cgd       666:        return (0);
                    667: }
                    668:
                    669: /*
                    670:  * Free a fragment reassembly header and all
                    671:  * associated datagrams.
                    672:  */
1.8       mycroft   673: void
1.1       cgd       674: ip_freef(fp)
                    675:        struct ipq *fp;
                    676: {
1.25      cgd       677:        register struct ipqent *q, *p;
1.1       cgd       678:
1.25      cgd       679:        for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
                    680:                p = q->ipqe_q.le_next;
1.50      thorpej   681:                m_freem(q->ipqe_m);
1.25      cgd       682:                LIST_REMOVE(q, ipqe_q);
                    683:                FREE(q, M_IPQ);
1.1       cgd       684:        }
1.25      cgd       685:        LIST_REMOVE(fp, ipq_q);
1.50      thorpej   686:        FREE(fp, M_FTABLE);
1.1       cgd       687: }
                    688:
                    689: /*
                    690:  * IP timer processing;
                    691:  * if a timer expires on a reassembly
                    692:  * queue, discard it.
                    693:  */
1.8       mycroft   694: void
1.1       cgd       695: ip_slowtimo()
                    696: {
1.25      cgd       697:        register struct ipq *fp, *nfp;
1.24      mycroft   698:        int s = splsoftnet();
1.1       cgd       699:
1.25      cgd       700:        for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
                    701:                nfp = fp->ipq_q.le_next;
                    702:                if (--fp->ipq_ttl == 0) {
1.1       cgd       703:                        ipstat.ips_fragtimeout++;
1.25      cgd       704:                        ip_freef(fp);
1.1       cgd       705:                }
                    706:        }
                    707:        splx(s);
                    708: }
                    709:
                    710: /*
                    711:  * Drain off all datagram fragments.
                    712:  */
1.8       mycroft   713: void
1.1       cgd       714: ip_drain()
                    715: {
                    716:
1.25      cgd       717:        while (ipq.lh_first != NULL) {
1.1       cgd       718:                ipstat.ips_fragdropped++;
1.25      cgd       719:                ip_freef(ipq.lh_first);
1.1       cgd       720:        }
                    721: }
                    722:
                    723: /*
                    724:  * Do option processing on a datagram,
                    725:  * possibly discarding it if bad options are encountered,
                    726:  * or forwarding it if source-routed.
                    727:  * Returns 1 if packet has been forwarded/freed,
                    728:  * 0 if the packet should be processed further.
                    729:  */
1.8       mycroft   730: int
1.1       cgd       731: ip_dooptions(m)
                    732:        struct mbuf *m;
                    733: {
                    734:        register struct ip *ip = mtod(m, struct ip *);
                    735:        register u_char *cp;
                    736:        register struct ip_timestamp *ipt;
                    737:        register struct in_ifaddr *ia;
                    738:        int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.13      mycroft   739:        struct in_addr *sin, dst;
1.1       cgd       740:        n_time ntime;
                    741:
1.13      mycroft   742:        dst = ip->ip_dst;
1.1       cgd       743:        cp = (u_char *)(ip + 1);
                    744:        cnt = (ip->ip_hl << 2) - sizeof (struct ip);
                    745:        for (; cnt > 0; cnt -= optlen, cp += optlen) {
                    746:                opt = cp[IPOPT_OPTVAL];
                    747:                if (opt == IPOPT_EOL)
                    748:                        break;
                    749:                if (opt == IPOPT_NOP)
                    750:                        optlen = 1;
                    751:                else {
                    752:                        optlen = cp[IPOPT_OLEN];
                    753:                        if (optlen <= 0 || optlen > cnt) {
                    754:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                    755:                                goto bad;
                    756:                        }
                    757:                }
                    758:                switch (opt) {
                    759:
                    760:                default:
                    761:                        break;
                    762:
                    763:                /*
                    764:                 * Source routing with record.
                    765:                 * Find interface with current destination address.
                    766:                 * If none on this machine then drop if strictly routed,
                    767:                 * or do nothing if loosely routed.
                    768:                 * Record interface address and bring up next address
                    769:                 * component.  If strictly routed make sure next
                    770:                 * address is on directly accessible net.
                    771:                 */
                    772:                case IPOPT_LSRR:
                    773:                case IPOPT_SSRR:
1.47      cjs       774:                        if (ip_allowsrcrt == 0) {
                    775:                                type = ICMP_UNREACH;
                    776:                                code = ICMP_UNREACH_NET_PROHIB;
                    777:                                goto bad;
                    778:                        }
1.1       cgd       779:                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                    780:                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                    781:                                goto bad;
                    782:                        }
                    783:                        ipaddr.sin_addr = ip->ip_dst;
1.19      mycroft   784:                        ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1       cgd       785:                        if (ia == 0) {
                    786:                                if (opt == IPOPT_SSRR) {
                    787:                                        type = ICMP_UNREACH;
                    788:                                        code = ICMP_UNREACH_SRCFAIL;
                    789:                                        goto bad;
                    790:                                }
                    791:                                /*
                    792:                                 * Loose routing, and not at next destination
                    793:                                 * yet; nothing to do except forward.
                    794:                                 */
                    795:                                break;
                    796:                        }
                    797:                        off--;                  /* 0 origin */
                    798:                        if (off > optlen - sizeof(struct in_addr)) {
                    799:                                /*
                    800:                                 * End of source route.  Should be for us.
                    801:                                 */
                    802:                                save_rte(cp, ip->ip_src);
                    803:                                break;
                    804:                        }
                    805:                        /*
                    806:                         * locate outgoing interface
                    807:                         */
                    808:                        bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
                    809:                            sizeof(ipaddr.sin_addr));
                    810:                        if (opt == IPOPT_SSRR) {
                    811: #define        INA     struct in_ifaddr *
                    812: #define        SA      struct sockaddr *
1.29      mrg       813:                            ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
1.1       cgd       814:                        } else
                    815:                                ia = ip_rtaddr(ipaddr.sin_addr);
                    816:                        if (ia == 0) {
                    817:                                type = ICMP_UNREACH;
                    818:                                code = ICMP_UNREACH_SRCFAIL;
                    819:                                goto bad;
                    820:                        }
                    821:                        ip->ip_dst = ipaddr.sin_addr;
1.20      mycroft   822:                        bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd       823:                            (caddr_t)(cp + off), sizeof(struct in_addr));
                    824:                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13      mycroft   825:                        /*
                    826:                         * Let ip_intr's mcast routing check handle mcast pkts
                    827:                         */
1.18      mycroft   828:                        forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1       cgd       829:                        break;
                    830:
                    831:                case IPOPT_RR:
                    832:                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                    833:                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                    834:                                goto bad;
                    835:                        }
                    836:                        /*
                    837:                         * If no space remains, ignore.
                    838:                         */
                    839:                        off--;                  /* 0 origin */
                    840:                        if (off > optlen - sizeof(struct in_addr))
                    841:                                break;
                    842:                        bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
                    843:                            sizeof(ipaddr.sin_addr));
                    844:                        /*
                    845:                         * locate outgoing interface; if we're the destination,
                    846:                         * use the incoming interface (should be same).
                    847:                         */
                    848:                        if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
                    849:                            (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
                    850:                                type = ICMP_UNREACH;
                    851:                                code = ICMP_UNREACH_HOST;
                    852:                                goto bad;
                    853:                        }
1.20      mycroft   854:                        bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd       855:                            (caddr_t)(cp + off), sizeof(struct in_addr));
                    856:                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
                    857:                        break;
                    858:
                    859:                case IPOPT_TS:
                    860:                        code = cp - (u_char *)ip;
                    861:                        ipt = (struct ip_timestamp *)cp;
                    862:                        if (ipt->ipt_len < 5)
                    863:                                goto bad;
1.15      cgd       864:                        if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.1       cgd       865:                                if (++ipt->ipt_oflw == 0)
                    866:                                        goto bad;
                    867:                                break;
                    868:                        }
                    869:                        sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
                    870:                        switch (ipt->ipt_flg) {
                    871:
                    872:                        case IPOPT_TS_TSONLY:
                    873:                                break;
                    874:
                    875:                        case IPOPT_TS_TSANDADDR:
                    876:                                if (ipt->ipt_ptr + sizeof(n_time) +
                    877:                                    sizeof(struct in_addr) > ipt->ipt_len)
                    878:                                        goto bad;
1.13      mycroft   879:                                ipaddr.sin_addr = dst;
                    880:                                ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
                    881:                                                            m->m_pkthdr.rcvif);
                    882:                                if (ia == 0)
                    883:                                        continue;
1.20      mycroft   884:                                bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd       885:                                    (caddr_t)sin, sizeof(struct in_addr));
                    886:                                ipt->ipt_ptr += sizeof(struct in_addr);
                    887:                                break;
                    888:
                    889:                        case IPOPT_TS_PRESPEC:
                    890:                                if (ipt->ipt_ptr + sizeof(n_time) +
                    891:                                    sizeof(struct in_addr) > ipt->ipt_len)
                    892:                                        goto bad;
                    893:                                bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
                    894:                                    sizeof(struct in_addr));
                    895:                                if (ifa_ifwithaddr((SA)&ipaddr) == 0)
                    896:                                        continue;
                    897:                                ipt->ipt_ptr += sizeof(struct in_addr);
                    898:                                break;
                    899:
                    900:                        default:
                    901:                                goto bad;
                    902:                        }
                    903:                        ntime = iptime();
                    904:                        bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
                    905:                            sizeof(n_time));
                    906:                        ipt->ipt_ptr += sizeof(n_time);
                    907:                }
                    908:        }
                    909:        if (forward) {
1.26      thorpej   910:                if (ip_forwsrcrt == 0) {
                    911:                        type = ICMP_UNREACH;
                    912:                        code = ICMP_UNREACH_SRCFAIL;
                    913:                        goto bad;
                    914:                }
1.1       cgd       915:                ip_forward(m, 1);
                    916:                return (1);
1.13      mycroft   917:        }
                    918:        return (0);
1.1       cgd       919: bad:
1.13      mycroft   920:        ip->ip_len -= ip->ip_hl << 2;   /* XXX icmp_error adds in hdr length */
                    921:        icmp_error(m, type, code, 0, 0);
                    922:        ipstat.ips_badoptions++;
1.1       cgd       923:        return (1);
                    924: }
                    925:
                    926: /*
                    927:  * Given address of next destination (final or next hop),
                    928:  * return internet address info of interface to be used to get there.
                    929:  */
                    930: struct in_ifaddr *
                    931: ip_rtaddr(dst)
                    932:         struct in_addr dst;
                    933: {
                    934:        register struct sockaddr_in *sin;
                    935:
1.19      mycroft   936:        sin = satosin(&ipforward_rt.ro_dst);
1.1       cgd       937:
1.35      mycroft   938:        if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1       cgd       939:                if (ipforward_rt.ro_rt) {
                    940:                        RTFREE(ipforward_rt.ro_rt);
                    941:                        ipforward_rt.ro_rt = 0;
                    942:                }
                    943:                sin->sin_family = AF_INET;
                    944:                sin->sin_len = sizeof(*sin);
                    945:                sin->sin_addr = dst;
                    946:
                    947:                rtalloc(&ipforward_rt);
                    948:        }
                    949:        if (ipforward_rt.ro_rt == 0)
                    950:                return ((struct in_ifaddr *)0);
1.19      mycroft   951:        return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1       cgd       952: }
                    953:
                    954: /*
                    955:  * Save incoming source route for use in replies,
                    956:  * to be picked up later by ip_srcroute if the receiver is interested.
                    957:  */
1.13      mycroft   958: void
1.1       cgd       959: save_rte(option, dst)
                    960:        u_char *option;
                    961:        struct in_addr dst;
                    962: {
                    963:        unsigned olen;
                    964:
                    965:        olen = option[IPOPT_OLEN];
                    966: #ifdef DIAGNOSTIC
                    967:        if (ipprintfs)
1.39      christos  968:                printf("save_rte: olen %d\n", olen);
1.1       cgd       969: #endif
                    970:        if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
                    971:                return;
                    972:        bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
                    973:        ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
                    974:        ip_srcrt.dst = dst;
                    975: }
                    976:
                    977: /*
                    978:  * Retrieve incoming source route for use in replies,
                    979:  * in the same form used by setsockopt.
                    980:  * The first hop is placed before the options, will be removed later.
                    981:  */
                    982: struct mbuf *
                    983: ip_srcroute()
                    984: {
                    985:        register struct in_addr *p, *q;
                    986:        register struct mbuf *m;
                    987:
                    988:        if (ip_nhops == 0)
                    989:                return ((struct mbuf *)0);
                    990:        m = m_get(M_DONTWAIT, MT_SOOPTS);
                    991:        if (m == 0)
                    992:                return ((struct mbuf *)0);
                    993:
1.13      mycroft   994: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1       cgd       995:
                    996:        /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
                    997:        m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
                    998:            OPTSIZ;
                    999: #ifdef DIAGNOSTIC
                   1000:        if (ipprintfs)
1.39      christos 1001:                printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1       cgd      1002: #endif
                   1003:
                   1004:        /*
                   1005:         * First save first hop for return route
                   1006:         */
                   1007:        p = &ip_srcrt.route[ip_nhops - 1];
                   1008:        *(mtod(m, struct in_addr *)) = *p--;
                   1009: #ifdef DIAGNOSTIC
                   1010:        if (ipprintfs)
1.39      christos 1011:                printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1       cgd      1012: #endif
                   1013:
                   1014:        /*
                   1015:         * Copy option fields and padding (nop) to mbuf.
                   1016:         */
                   1017:        ip_srcrt.nop = IPOPT_NOP;
                   1018:        ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
                   1019:        bcopy((caddr_t)&ip_srcrt.nop,
                   1020:            mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
                   1021:        q = (struct in_addr *)(mtod(m, caddr_t) +
                   1022:            sizeof(struct in_addr) + OPTSIZ);
                   1023: #undef OPTSIZ
                   1024:        /*
                   1025:         * Record return path as an IP source route,
                   1026:         * reversing the path (pointers are now aligned).
                   1027:         */
                   1028:        while (p >= ip_srcrt.route) {
                   1029: #ifdef DIAGNOSTIC
                   1030:                if (ipprintfs)
1.39      christos 1031:                        printf(" %x", ntohl(q->s_addr));
1.1       cgd      1032: #endif
                   1033:                *q++ = *p--;
                   1034:        }
                   1035:        /*
                   1036:         * Last hop goes to final destination.
                   1037:         */
                   1038:        *q = ip_srcrt.dst;
                   1039: #ifdef DIAGNOSTIC
                   1040:        if (ipprintfs)
1.39      christos 1041:                printf(" %x\n", ntohl(q->s_addr));
1.1       cgd      1042: #endif
                   1043:        return (m);
                   1044: }
                   1045:
                   1046: /*
                   1047:  * Strip out IP options, at higher
                   1048:  * level protocol in the kernel.
                   1049:  * Second argument is buffer to which options
                   1050:  * will be moved, and return value is their length.
                   1051:  * XXX should be deleted; last arg currently ignored.
                   1052:  */
1.8       mycroft  1053: void
1.1       cgd      1054: ip_stripoptions(m, mopt)
                   1055:        register struct mbuf *m;
                   1056:        struct mbuf *mopt;
                   1057: {
                   1058:        register int i;
                   1059:        struct ip *ip = mtod(m, struct ip *);
                   1060:        register caddr_t opts;
                   1061:        int olen;
                   1062:
                   1063:        olen = (ip->ip_hl<<2) - sizeof (struct ip);
                   1064:        opts = (caddr_t)(ip + 1);
                   1065:        i = m->m_len - (sizeof (struct ip) + olen);
                   1066:        bcopy(opts  + olen, opts, (unsigned)i);
                   1067:        m->m_len -= olen;
                   1068:        if (m->m_flags & M_PKTHDR)
                   1069:                m->m_pkthdr.len -= olen;
                   1070:        ip->ip_hl = sizeof(struct ip) >> 2;
                   1071: }
                   1072:
1.23      mycroft  1073: int inetctlerrmap[PRC_NCMDS] = {
1.1       cgd      1074:        0,              0,              0,              0,
                   1075:        0,              EMSGSIZE,       EHOSTDOWN,      EHOSTUNREACH,
                   1076:        EHOSTUNREACH,   EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
                   1077:        EMSGSIZE,       EHOSTUNREACH,   0,              0,
                   1078:        0,              0,              0,              0,
                   1079:        ENOPROTOOPT
                   1080: };
                   1081:
                   1082: /*
                   1083:  * Forward a packet.  If some error occurs return the sender
                   1084:  * an icmp packet.  Note we can't always generate a meaningful
                   1085:  * icmp message because icmp doesn't have a large enough repertoire
                   1086:  * of codes and types.
                   1087:  *
                   1088:  * If not forwarding, just drop the packet.  This could be confusing
                   1089:  * if ipforwarding was zero but some routing protocol was advancing
                   1090:  * us as a gateway to somewhere.  However, we must let the routing
                   1091:  * protocol deal with that.
                   1092:  *
                   1093:  * The srcrt parameter indicates whether the packet is being forwarded
                   1094:  * via a source route.
                   1095:  */
1.13      mycroft  1096: void
1.1       cgd      1097: ip_forward(m, srcrt)
                   1098:        struct mbuf *m;
                   1099:        int srcrt;
                   1100: {
                   1101:        register struct ip *ip = mtod(m, struct ip *);
                   1102:        register struct sockaddr_in *sin;
                   1103:        register struct rtentry *rt;
1.28      christos 1104:        int error, type = 0, code = 0;
1.1       cgd      1105:        struct mbuf *mcopy;
1.13      mycroft  1106:        n_long dest;
                   1107:        struct ifnet *destifp;
1.1       cgd      1108:
1.13      mycroft  1109:        dest = 0;
1.1       cgd      1110: #ifdef DIAGNOSTIC
                   1111:        if (ipprintfs)
1.39      christos 1112:                printf("forward: src %x dst %x ttl %x\n",
1.35      mycroft  1113:                    ip->ip_src.s_addr, ip->ip_dst.s_addr, ip->ip_ttl);
1.1       cgd      1114: #endif
                   1115:        if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
                   1116:                ipstat.ips_cantforward++;
                   1117:                m_freem(m);
                   1118:                return;
                   1119:        }
                   1120:        HTONS(ip->ip_id);
                   1121:        if (ip->ip_ttl <= IPTTLDEC) {
1.13      mycroft  1122:                icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1       cgd      1123:                return;
                   1124:        }
                   1125:        ip->ip_ttl -= IPTTLDEC;
                   1126:
1.19      mycroft  1127:        sin = satosin(&ipforward_rt.ro_dst);
1.1       cgd      1128:        if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35      mycroft  1129:            !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1       cgd      1130:                if (ipforward_rt.ro_rt) {
                   1131:                        RTFREE(ipforward_rt.ro_rt);
                   1132:                        ipforward_rt.ro_rt = 0;
                   1133:                }
                   1134:                sin->sin_family = AF_INET;
1.35      mycroft  1135:                sin->sin_len = sizeof(struct sockaddr_in);
1.1       cgd      1136:                sin->sin_addr = ip->ip_dst;
                   1137:
                   1138:                rtalloc(&ipforward_rt);
                   1139:                if (ipforward_rt.ro_rt == 0) {
1.13      mycroft  1140:                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1       cgd      1141:                        return;
                   1142:                }
                   1143:                rt = ipforward_rt.ro_rt;
                   1144:        }
                   1145:
                   1146:        /*
1.34      mycroft  1147:         * Save at most 68 bytes of the packet in case
1.1       cgd      1148:         * we need to generate an ICMP message to the src.
                   1149:         */
1.34      mycroft  1150:        mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
1.1       cgd      1151:
                   1152:        /*
                   1153:         * If forwarding packet using same interface that it came in on,
                   1154:         * perhaps should send a redirect to sender to shortcut a hop.
                   1155:         * Only send redirect if source is sending directly to us,
                   1156:         * and if packet was not source routed (or has any options).
                   1157:         * Also, don't send redirect if forwarding using a default route
                   1158:         * or a route modified by a redirect.
                   1159:         */
                   1160:        if (rt->rt_ifp == m->m_pkthdr.rcvif &&
                   1161:            (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35      mycroft  1162:            !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1       cgd      1163:            ipsendredirects && !srcrt) {
1.19      mycroft  1164:                if (rt->rt_ifa &&
                   1165:                    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
                   1166:                    ifatoia(rt->rt_ifa)->ia_subnet) {
1.1       cgd      1167:                    if (rt->rt_flags & RTF_GATEWAY)
1.13      mycroft  1168:                        dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1.1       cgd      1169:                    else
1.13      mycroft  1170:                        dest = ip->ip_dst.s_addr;
                   1171:                    /* Router requirements says to only send host redirects */
1.1       cgd      1172:                    type = ICMP_REDIRECT;
1.13      mycroft  1173:                    code = ICMP_REDIRECT_HOST;
1.1       cgd      1174: #ifdef DIAGNOSTIC
                   1175:                    if (ipprintfs)
1.39      christos 1176:                        printf("redirect (%d) to %x\n", code, (u_int32_t)dest);
1.1       cgd      1177: #endif
                   1178:                }
                   1179:        }
                   1180:
1.27      thorpej  1181:        error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
                   1182:            (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1       cgd      1183:        if (error)
                   1184:                ipstat.ips_cantforward++;
                   1185:        else {
                   1186:                ipstat.ips_forward++;
                   1187:                if (type)
                   1188:                        ipstat.ips_redirectsent++;
                   1189:                else {
                   1190:                        if (mcopy)
                   1191:                                m_freem(mcopy);
                   1192:                        return;
                   1193:                }
                   1194:        }
                   1195:        if (mcopy == NULL)
                   1196:                return;
1.13      mycroft  1197:        destifp = NULL;
                   1198:
1.1       cgd      1199:        switch (error) {
                   1200:
                   1201:        case 0:                         /* forwarded, but need redirect */
                   1202:                /* type, code set above */
                   1203:                break;
                   1204:
                   1205:        case ENETUNREACH:               /* shouldn't happen, checked above */
                   1206:        case EHOSTUNREACH:
                   1207:        case ENETDOWN:
                   1208:        case EHOSTDOWN:
                   1209:        default:
                   1210:                type = ICMP_UNREACH;
                   1211:                code = ICMP_UNREACH_HOST;
                   1212:                break;
                   1213:
                   1214:        case EMSGSIZE:
                   1215:                type = ICMP_UNREACH;
                   1216:                code = ICMP_UNREACH_NEEDFRAG;
1.13      mycroft  1217:                if (ipforward_rt.ro_rt)
                   1218:                        destifp = ipforward_rt.ro_rt->rt_ifp;
1.1       cgd      1219:                ipstat.ips_cantfrag++;
                   1220:                break;
                   1221:
                   1222:        case ENOBUFS:
                   1223:                type = ICMP_SOURCEQUENCH;
                   1224:                code = 0;
                   1225:                break;
                   1226:        }
1.13      mycroft  1227:        icmp_error(mcopy, type, code, dest, destifp);
1.44      thorpej  1228: }
                   1229:
                   1230: void
                   1231: ip_savecontrol(inp, mp, ip, m)
                   1232:        register struct inpcb *inp;
                   1233:        register struct mbuf **mp;
                   1234:        register struct ip *ip;
                   1235:        register struct mbuf *m;
                   1236: {
                   1237:
                   1238:        if (inp->inp_socket->so_options & SO_TIMESTAMP) {
                   1239:                struct timeval tv;
                   1240:
                   1241:                microtime(&tv);
                   1242:                *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
                   1243:                    SCM_TIMESTAMP, SOL_SOCKET);
                   1244:                if (*mp)
                   1245:                        mp = &(*mp)->m_next;
                   1246:        }
                   1247:        if (inp->inp_flags & INP_RECVDSTADDR) {
                   1248:                *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
                   1249:                    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
                   1250:                if (*mp)
                   1251:                        mp = &(*mp)->m_next;
                   1252:        }
                   1253: #ifdef notyet
                   1254:        /*
                   1255:         * XXX
                   1256:         * Moving these out of udp_input() made them even more broken
                   1257:         * than they already were.
                   1258:         *      - fenner@parc.xerox.com
                   1259:         */
                   1260:        /* options were tossed already */
                   1261:        if (inp->inp_flags & INP_RECVOPTS) {
                   1262:                *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
                   1263:                    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
                   1264:                if (*mp)
                   1265:                        mp = &(*mp)->m_next;
                   1266:        }
                   1267:        /* ip_srcroute doesn't do what we want here, need to fix */
                   1268:        if (inp->inp_flags & INP_RECVRETOPTS) {
                   1269:                *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
                   1270:                    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
                   1271:                if (*mp)
                   1272:                        mp = &(*mp)->m_next;
                   1273:        }
                   1274: #endif
                   1275:        if (inp->inp_flags & INP_RECVIF) {
                   1276:                struct sockaddr_dl sdl;
                   1277:
                   1278:                sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
                   1279:                sdl.sdl_family = AF_LINK;
                   1280:                sdl.sdl_index = m->m_pkthdr.rcvif ?
                   1281:                    m->m_pkthdr.rcvif->if_index : 0;
                   1282:                sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
                   1283:                *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
                   1284:                    IP_RECVIF, IPPROTO_IP);
                   1285:                if (*mp)
                   1286:                        mp = &(*mp)->m_next;
                   1287:        }
1.13      mycroft  1288: }
                   1289:
                   1290: int
                   1291: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
                   1292:        int *name;
                   1293:        u_int namelen;
                   1294:        void *oldp;
                   1295:        size_t *oldlenp;
                   1296:        void *newp;
                   1297:        size_t newlen;
                   1298: {
1.52      thorpej  1299:        extern int subnetsarelocal;
                   1300:
1.54      lukem    1301:        int error, old;
                   1302:
1.13      mycroft  1303:        /* All sysctl names at this level are terminal. */
                   1304:        if (namelen != 1)
                   1305:                return (ENOTDIR);
                   1306:
                   1307:        switch (name[0]) {
                   1308:        case IPCTL_FORWARDING:
                   1309:                return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
                   1310:        case IPCTL_SENDREDIRECTS:
                   1311:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1312:                        &ipsendredirects));
                   1313:        case IPCTL_DEFTTL:
                   1314:                return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
                   1315: #ifdef notyet
                   1316:        case IPCTL_DEFMTU:
                   1317:                return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
                   1318: #endif
1.26      thorpej  1319:        case IPCTL_FORWSRCRT:
1.47      cjs      1320:                /* Don't allow this to change in a secure environment.  */
1.26      thorpej  1321:                if (securelevel > 0)
1.46      cjs      1322:                        return (sysctl_rdint(oldp, oldlenp, newp,
                   1323:                            ip_forwsrcrt));
                   1324:                else
                   1325:                        return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1326:                            &ip_forwsrcrt));
1.27      thorpej  1327:        case IPCTL_DIRECTEDBCAST:
                   1328:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1329:                    &ip_directedbcast));
1.47      cjs      1330:        case IPCTL_ALLOWSRCRT:
                   1331:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1332:                    &ip_allowsrcrt));
1.52      thorpej  1333:        case IPCTL_SUBNETSARELOCAL:
                   1334:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1335:                    &subnetsarelocal));
1.53      kml      1336:        case IPCTL_MTUDISC:
1.60      kml      1337:                error = sysctl_int(oldp, oldlenp, newp, newlen,
                   1338:                    &ip_mtudisc);
                   1339:                if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
                   1340:                        ip_mtudisc_timeout_q =
                   1341:                            rt_timer_queue_create(ip_mtudisc_timeout);
                   1342:                } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
                   1343:                        rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
                   1344:                        ip_mtudisc_timeout_q = NULL;
                   1345:                }
                   1346:                return error;
1.54      lukem    1347:        case IPCTL_ANONPORTMIN:
                   1348:                old = anonportmin;
                   1349:                error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
                   1350:                if (anonportmin >= anonportmax || anonportmin > 65535
                   1351: #ifndef IPNOPRIVPORTS
                   1352:                    || anonportmin < IPPORT_RESERVED
                   1353: #endif
                   1354:                    ) {
                   1355:                        anonportmin = old;
                   1356:                        return (EINVAL);
                   1357:                }
                   1358:                return (error);
                   1359:        case IPCTL_ANONPORTMAX:
                   1360:                old = anonportmax;
                   1361:                error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
                   1362:                if (anonportmin >= anonportmax || anonportmax > 65535
                   1363: #ifndef IPNOPRIVPORTS
                   1364:                    || anonportmax < IPPORT_RESERVED
                   1365: #endif
                   1366:                    ) {
                   1367:                        anonportmax = old;
                   1368:                        return (EINVAL);
                   1369:                }
1.60      kml      1370:                return (error);
                   1371:        case IPCTL_MTUDISCTIMEOUT:
                   1372:                error = sysctl_int(oldp, oldlenp, newp, newlen,
                   1373:                   &ip_mtudisc_timeout);
                   1374:                if (ip_mtudisc_timeout_q != NULL)
                   1375:                        rt_timer_queue_change(ip_mtudisc_timeout_q,
                   1376:                                              ip_mtudisc_timeout);
1.54      lukem    1377:                return (error);
1.13      mycroft  1378:        default:
                   1379:                return (EOPNOTSUPP);
                   1380:        }
                   1381:        /* NOTREACHED */
1.1       cgd      1382: }

CVSweb <webmaster@jp.NetBSD.org>