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Annotation of src/sys/netinet/ip_input.c, Revision 1.133

1.133   ! itojun      1: /*     $NetBSD: ip_input.c,v 1.132 2001/04/13 23:30:22 thorpej Exp $   */
1.89      itojun      2:
                      3: /*
                      4:  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
                      5:  * All rights reserved.
                      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. Neither the name of the project nor the names of its contributors
                     16:  *    may be used to endorse or promote products derived from this software
                     17:  *    without specific prior written permission.
                     18:  *
                     19:  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
                     20:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     21:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     22:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
                     23:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     24:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     25:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     26:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     27:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     28:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     29:  * SUCH DAMAGE.
                     30:  */
1.76      thorpej    31:
                     32: /*-
                     33:  * Copyright (c) 1998 The NetBSD Foundation, Inc.
                     34:  * All rights reserved.
                     35:  *
                     36:  * This code is derived from software contributed to The NetBSD Foundation
                     37:  * by Public Access Networks Corporation ("Panix").  It was developed under
                     38:  * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
                     39:  *
                     40:  * Redistribution and use in source and binary forms, with or without
                     41:  * modification, are permitted provided that the following conditions
                     42:  * are met:
                     43:  * 1. Redistributions of source code must retain the above copyright
                     44:  *    notice, this list of conditions and the following disclaimer.
                     45:  * 2. Redistributions in binary form must reproduce the above copyright
                     46:  *    notice, this list of conditions and the following disclaimer in the
                     47:  *    documentation and/or other materials provided with the distribution.
                     48:  * 3. All advertising materials mentioning features or use of this software
                     49:  *    must display the following acknowledgement:
                     50:  *     This product includes software developed by the NetBSD
                     51:  *     Foundation, Inc. and its contributors.
                     52:  * 4. Neither the name of The NetBSD Foundation nor the names of its
                     53:  *    contributors may be used to endorse or promote products derived
                     54:  *    from this software without specific prior written permission.
                     55:  *
                     56:  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
                     57:  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
                     58:  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
                     59:  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
                     60:  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
                     61:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
                     62:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
                     63:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
                     64:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
                     65:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
                     66:  * POSSIBILITY OF SUCH DAMAGE.
                     67:  */
1.14      cgd        68:
1.1       cgd        69: /*
1.13      mycroft    70:  * Copyright (c) 1982, 1986, 1988, 1993
                     71:  *     The Regents of the University of California.  All rights reserved.
1.1       cgd        72:  *
                     73:  * Redistribution and use in source and binary forms, with or without
                     74:  * modification, are permitted provided that the following conditions
                     75:  * are met:
                     76:  * 1. Redistributions of source code must retain the above copyright
                     77:  *    notice, this list of conditions and the following disclaimer.
                     78:  * 2. Redistributions in binary form must reproduce the above copyright
                     79:  *    notice, this list of conditions and the following disclaimer in the
                     80:  *    documentation and/or other materials provided with the distribution.
                     81:  * 3. All advertising materials mentioning features or use of this software
                     82:  *    must display the following acknowledgement:
                     83:  *     This product includes software developed by the University of
                     84:  *     California, Berkeley and its contributors.
                     85:  * 4. Neither the name of the University nor the names of its contributors
                     86:  *    may be used to endorse or promote products derived from this software
                     87:  *    without specific prior written permission.
                     88:  *
                     89:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     90:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     91:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     92:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     93:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     94:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     95:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     96:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     97:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     98:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     99:  * SUCH DAMAGE.
                    100:  *
1.14      cgd       101:  *     @(#)ip_input.c  8.2 (Berkeley) 1/4/94
1.1       cgd       102:  */
1.55      scottr    103:
1.62      matt      104: #include "opt_gateway.h"
1.69      mrg       105: #include "opt_pfil_hooks.h"
1.91      thorpej   106: #include "opt_ipsec.h"
1.55      scottr    107: #include "opt_mrouting.h"
1.1       cgd       108:
1.5       mycroft   109: #include <sys/param.h>
                    110: #include <sys/systm.h>
                    111: #include <sys/malloc.h>
                    112: #include <sys/mbuf.h>
                    113: #include <sys/domain.h>
                    114: #include <sys/protosw.h>
                    115: #include <sys/socket.h>
1.44      thorpej   116: #include <sys/socketvar.h>
1.5       mycroft   117: #include <sys/errno.h>
                    118: #include <sys/time.h>
                    119: #include <sys/kernel.h>
1.28      christos  120: #include <sys/proc.h>
1.72      thorpej   121: #include <sys/pool.h>
1.28      christos  122:
1.115     mrg       123: #include <uvm/uvm_extern.h>
                    124:
1.28      christos  125: #include <sys/sysctl.h>
1.1       cgd       126:
1.5       mycroft   127: #include <net/if.h>
1.44      thorpej   128: #include <net/if_dl.h>
1.5       mycroft   129: #include <net/route.h>
1.45      mrg       130: #include <net/pfil.h>
1.1       cgd       131:
1.5       mycroft   132: #include <netinet/in.h>
                    133: #include <netinet/in_systm.h>
                    134: #include <netinet/ip.h>
                    135: #include <netinet/in_pcb.h>
                    136: #include <netinet/in_var.h>
                    137: #include <netinet/ip_var.h>
                    138: #include <netinet/ip_icmp.h>
1.89      itojun    139: /* just for gif_ttl */
                    140: #include <netinet/in_gif.h>
                    141: #include "gif.h"
1.111     jdolecek  142:
                    143: #ifdef MROUTING
                    144: #include <netinet/ip_mroute.h>
                    145: #endif
1.89      itojun    146:
                    147: #ifdef IPSEC
                    148: #include <netinet6/ipsec.h>
                    149: #include <netkey/key.h>
                    150: #endif
1.44      thorpej   151:
1.1       cgd       152: #ifndef        IPFORWARDING
                    153: #ifdef GATEWAY
                    154: #define        IPFORWARDING    1       /* forward IP packets not for us */
                    155: #else /* GATEWAY */
                    156: #define        IPFORWARDING    0       /* don't forward IP packets not for us */
                    157: #endif /* GATEWAY */
                    158: #endif /* IPFORWARDING */
                    159: #ifndef        IPSENDREDIRECTS
                    160: #define        IPSENDREDIRECTS 1
                    161: #endif
1.26      thorpej   162: #ifndef IPFORWSRCRT
1.47      cjs       163: #define        IPFORWSRCRT     1       /* forward source-routed packets */
                    164: #endif
                    165: #ifndef IPALLOWSRCRT
1.48      mrg       166: #define        IPALLOWSRCRT    1       /* allow source-routed packets */
1.26      thorpej   167: #endif
1.53      kml       168: #ifndef IPMTUDISC
                    169: #define IPMTUDISC      0
                    170: #endif
1.60      kml       171: #ifndef IPMTUDISCTIMEOUT
1.61      kml       172: #define IPMTUDISCTIMEOUT (10 * 60)     /* as per RFC 1191 */
1.60      kml       173: #endif
1.53      kml       174:
1.27      thorpej   175: /*
                    176:  * Note: DIRECTED_BROADCAST is handled this way so that previous
                    177:  * configuration using this option will Just Work.
                    178:  */
                    179: #ifndef IPDIRECTEDBCAST
                    180: #ifdef DIRECTED_BROADCAST
                    181: #define IPDIRECTEDBCAST        1
                    182: #else
                    183: #define        IPDIRECTEDBCAST 0
                    184: #endif /* DIRECTED_BROADCAST */
                    185: #endif /* IPDIRECTEDBCAST */
1.1       cgd       186: int    ipforwarding = IPFORWARDING;
                    187: int    ipsendredirects = IPSENDREDIRECTS;
1.13      mycroft   188: int    ip_defttl = IPDEFTTL;
1.26      thorpej   189: int    ip_forwsrcrt = IPFORWSRCRT;
1.27      thorpej   190: int    ip_directedbcast = IPDIRECTEDBCAST;
1.47      cjs       191: int    ip_allowsrcrt = IPALLOWSRCRT;
1.53      kml       192: int    ip_mtudisc = IPMTUDISC;
1.60      kml       193: u_int  ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1       cgd       194: #ifdef DIAGNOSTIC
                    195: int    ipprintfs = 0;
                    196: #endif
                    197:
1.60      kml       198: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
                    199:
1.1       cgd       200: extern struct domain inetdomain;
                    201: int    ipqmaxlen = IFQ_MAXLEN;
1.22      mycroft   202: struct in_ifaddrhead in_ifaddr;
1.57      tls       203: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.13      mycroft   204: struct ifqueue ipintrq;
1.63      matt      205: struct ipstat  ipstat;
                    206: u_int16_t      ip_id;
1.75      thorpej   207:
1.121     thorpej   208: #ifdef PFIL_HOOKS
                    209: struct pfil_head inet_pfil_hook;
                    210: #endif
                    211:
1.63      matt      212: struct ipqhead ipq;
1.75      thorpej   213: int    ipq_locked;
1.131     itojun    214: int    ip_nfragpackets = 0;
1.133   ! itojun    215: int    ip_maxfragpackets = 200;
1.75      thorpej   216:
                    217: static __inline int ipq_lock_try __P((void));
                    218: static __inline void ipq_unlock __P((void));
                    219:
                    220: static __inline int
                    221: ipq_lock_try()
                    222: {
                    223:        int s;
                    224:
1.132     thorpej   225:        /*
                    226:         * Use splvm() -- we're bloking things that would cause
                    227:         * mbuf allocation.
                    228:         */
                    229:        s = splvm();
1.75      thorpej   230:        if (ipq_locked) {
                    231:                splx(s);
                    232:                return (0);
                    233:        }
                    234:        ipq_locked = 1;
                    235:        splx(s);
                    236:        return (1);
                    237: }
                    238:
                    239: static __inline void
                    240: ipq_unlock()
                    241: {
                    242:        int s;
                    243:
1.132     thorpej   244:        s = splvm();
1.75      thorpej   245:        ipq_locked = 0;
                    246:        splx(s);
                    247: }
                    248:
                    249: #ifdef DIAGNOSTIC
                    250: #define        IPQ_LOCK()                                                      \
                    251: do {                                                                   \
                    252:        if (ipq_lock_try() == 0) {                                      \
                    253:                printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
                    254:                panic("ipq_lock");                                      \
                    255:        }                                                               \
                    256: } while (0)
                    257: #define        IPQ_LOCK_CHECK()                                                \
                    258: do {                                                                   \
                    259:        if (ipq_locked == 0) {                                          \
                    260:                printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
                    261:                panic("ipq lock check");                                \
                    262:        }                                                               \
                    263: } while (0)
                    264: #else
                    265: #define        IPQ_LOCK()              (void) ipq_lock_try()
                    266: #define        IPQ_LOCK_CHECK()        /* nothing */
                    267: #endif
                    268:
                    269: #define        IPQ_UNLOCK()            ipq_unlock()
1.1       cgd       270:
1.72      thorpej   271: struct pool ipqent_pool;
                    272:
1.1       cgd       273: /*
                    274:  * We need to save the IP options in case a protocol wants to respond
                    275:  * to an incoming packet over the same route if the packet got here
                    276:  * using IP source routing.  This allows connection establishment and
                    277:  * maintenance when the remote end is on a network that is not known
                    278:  * to us.
                    279:  */
                    280: int    ip_nhops = 0;
                    281: static struct ip_srcrt {
                    282:        struct  in_addr dst;                    /* final destination */
                    283:        char    nop;                            /* one NOP to align */
                    284:        char    srcopt[IPOPT_OFFSET + 1];       /* OPTVAL, OLEN and OFFSET */
                    285:        struct  in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
                    286: } ip_srcrt;
                    287:
1.13      mycroft   288: static void save_rte __P((u_char *, struct in_addr));
1.35      mycroft   289:
1.1       cgd       290: /*
                    291:  * IP initialization: fill in IP protocol switch table.
                    292:  * All protocols not implemented in kernel go to raw IP protocol handler.
                    293:  */
1.8       mycroft   294: void
1.1       cgd       295: ip_init()
                    296: {
1.109     augustss  297:        struct protosw *pr;
                    298:        int i;
1.1       cgd       299:
1.72      thorpej   300:        pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
                    301:            0, NULL, NULL, M_IPQ);
                    302:
1.1       cgd       303:        pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
                    304:        if (pr == 0)
                    305:                panic("ip_init");
                    306:        for (i = 0; i < IPPROTO_MAX; i++)
                    307:                ip_protox[i] = pr - inetsw;
                    308:        for (pr = inetdomain.dom_protosw;
                    309:            pr < inetdomain.dom_protoswNPROTOSW; pr++)
                    310:                if (pr->pr_domain->dom_family == PF_INET &&
                    311:                    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
                    312:                        ip_protox[pr->pr_protocol] = pr - inetsw;
1.25      cgd       313:        LIST_INIT(&ipq);
1.1       cgd       314:        ip_id = time.tv_sec & 0xffff;
                    315:        ipintrq.ifq_maxlen = ipqmaxlen;
1.22      mycroft   316:        TAILQ_INIT(&in_ifaddr);
1.120     ad        317:        in_ifaddrhashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IFADDR,
                    318:            M_WAITOK, &in_ifaddrhash);
1.60      kml       319:        if (ip_mtudisc != 0)
                    320:                ip_mtudisc_timeout_q =
                    321:                    rt_timer_queue_create(ip_mtudisc_timeout);
1.73      thorpej   322: #ifdef GATEWAY
                    323:        ipflow_init();
                    324: #endif
1.121     thorpej   325:
                    326: #ifdef PFIL_HOOKS
                    327:        /* Register our Packet Filter hook. */
1.126     thorpej   328:        inet_pfil_hook.ph_type = PFIL_TYPE_AF;
                    329:        inet_pfil_hook.ph_af   = AF_INET;
1.121     thorpej   330:        i = pfil_head_register(&inet_pfil_hook);
                    331:        if (i != 0)
                    332:                printf("ip_init: WARNING: unable to register pfil hook, "
                    333:                    "error %d\n", i);
                    334: #endif /* PFIL_HOOKS */
1.1       cgd       335: }
                    336:
                    337: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
                    338: struct route ipforward_rt;
                    339:
                    340: /*
1.89      itojun    341:  * IP software interrupt routine
                    342:  */
                    343: void
                    344: ipintr()
                    345: {
                    346:        int s;
                    347:        struct mbuf *m;
                    348:
                    349:        while (1) {
1.132     thorpej   350:                s = splnet();
1.89      itojun    351:                IF_DEQUEUE(&ipintrq, m);
                    352:                splx(s);
                    353:                if (m == 0)
                    354:                        return;
                    355:                ip_input(m);
                    356:        }
                    357: }
                    358:
                    359: /*
1.1       cgd       360:  * Ip input routine.  Checksum and byte swap header.  If fragmented
                    361:  * try to reassemble.  Process options.  Pass to next level.
                    362:  */
1.8       mycroft   363: void
1.89      itojun    364: ip_input(struct mbuf *m)
1.1       cgd       365: {
1.109     augustss  366:        struct ip *ip = NULL;
                    367:        struct ipq *fp;
                    368:        struct in_ifaddr *ia;
                    369:        struct ifaddr *ifa;
1.25      cgd       370:        struct ipqent *ipqe;
1.89      itojun    371:        int hlen = 0, mff, len;
1.100     itojun    372:        int downmatch;
1.1       cgd       373:
                    374: #ifdef DIAGNOSTIC
                    375:        if ((m->m_flags & M_PKTHDR) == 0)
                    376:                panic("ipintr no HDR");
                    377: #endif
1.89      itojun    378: #ifdef IPSEC
                    379:        /*
                    380:         * should the inner packet be considered authentic?
                    381:         * see comment in ah4_input().
                    382:         */
                    383:        if (m) {
                    384:                m->m_flags &= ~M_AUTHIPHDR;
                    385:                m->m_flags &= ~M_AUTHIPDGM;
                    386:        }
                    387: #endif
1.1       cgd       388:        /*
                    389:         * If no IP addresses have been set yet but the interfaces
                    390:         * are receiving, can't do anything with incoming packets yet.
                    391:         */
1.22      mycroft   392:        if (in_ifaddr.tqh_first == 0)
1.1       cgd       393:                goto bad;
                    394:        ipstat.ips_total++;
                    395:        if (m->m_len < sizeof (struct ip) &&
                    396:            (m = m_pullup(m, sizeof (struct ip))) == 0) {
                    397:                ipstat.ips_toosmall++;
1.89      itojun    398:                return;
1.1       cgd       399:        }
                    400:        ip = mtod(m, struct ip *);
1.13      mycroft   401:        if (ip->ip_v != IPVERSION) {
                    402:                ipstat.ips_badvers++;
                    403:                goto bad;
                    404:        }
1.1       cgd       405:        hlen = ip->ip_hl << 2;
                    406:        if (hlen < sizeof(struct ip)) { /* minimum header length */
                    407:                ipstat.ips_badhlen++;
                    408:                goto bad;
                    409:        }
                    410:        if (hlen > m->m_len) {
                    411:                if ((m = m_pullup(m, hlen)) == 0) {
                    412:                        ipstat.ips_badhlen++;
1.89      itojun    413:                        return;
1.1       cgd       414:                }
                    415:                ip = mtod(m, struct ip *);
                    416:        }
1.98      thorpej   417:
1.85      hwr       418:        /*
1.99      thorpej   419:         * RFC1122: packets with a multicast source address are
1.98      thorpej   420:         * not allowed.
1.85      hwr       421:         */
                    422:        if (IN_MULTICAST(ip->ip_src.s_addr)) {
1.130     itojun    423:                ipstat.ips_badaddr++;
1.85      hwr       424:                goto bad;
1.129     itojun    425:        }
                    426:
                    427:        /* 127/8 must not appear on wire - RFC1122 */
                    428:        if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
                    429:            (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
1.130     itojun    430:                if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
                    431:                        ipstat.ips_badaddr++;
1.129     itojun    432:                        goto bad;
1.130     itojun    433:                }
1.85      hwr       434:        }
                    435:
1.78      mycroft   436:        if (in_cksum(m, hlen) != 0) {
1.1       cgd       437:                ipstat.ips_badsum++;
                    438:                goto bad;
                    439:        }
                    440:
1.121     thorpej   441:        /* Retrieve the packet length. */
                    442:        len = ntohs(ip->ip_len);
1.81      proff     443:
                    444:        /*
                    445:         * Check for additional length bogosity
                    446:         */
1.84      proff     447:        if (len < hlen) {
1.81      proff     448:                ipstat.ips_badlen++;
                    449:                goto bad;
                    450:        }
1.1       cgd       451:
                    452:        /*
                    453:         * Check that the amount of data in the buffers
                    454:         * is as at least much as the IP header would have us expect.
                    455:         * Trim mbufs if longer than we expect.
                    456:         * Drop packet if shorter than we expect.
                    457:         */
1.35      mycroft   458:        if (m->m_pkthdr.len < len) {
1.1       cgd       459:                ipstat.ips_tooshort++;
                    460:                goto bad;
                    461:        }
1.35      mycroft   462:        if (m->m_pkthdr.len > len) {
1.1       cgd       463:                if (m->m_len == m->m_pkthdr.len) {
1.35      mycroft   464:                        m->m_len = len;
                    465:                        m->m_pkthdr.len = len;
1.1       cgd       466:                } else
1.35      mycroft   467:                        m_adj(m, len - m->m_pkthdr.len);
1.1       cgd       468:        }
                    469:
1.94      itojun    470: #ifdef IPSEC
                    471:        /* ipflow (IP fast fowarding) is not compatible with IPsec. */
                    472:        m->m_flags &= ~M_CANFASTFWD;
                    473: #else
1.64      thorpej   474:        /*
                    475:         * Assume that we can create a fast-forward IP flow entry
                    476:         * based on this packet.
                    477:         */
                    478:        m->m_flags |= M_CANFASTFWD;
1.94      itojun    479: #endif
1.64      thorpej   480:
1.36      mrg       481: #ifdef PFIL_HOOKS
1.33      mrg       482:        /*
1.64      thorpej   483:         * Run through list of hooks for input packets.  If there are any
                    484:         * filters which require that additional packets in the flow are
                    485:         * not fast-forwarded, they must clear the M_CANFASTFWD flag.
                    486:         * Note that filters must _never_ set this flag, as another filter
                    487:         * in the list may have previously cleared it.
1.33      mrg       488:         */
1.127     itojun    489:        /*
                    490:         * let ipfilter look at packet on the wire,
                    491:         * not the decapsulated packet.
                    492:         */
                    493: #ifdef IPSEC
                    494:        if (!ipsec_gethist(m, NULL))
                    495: #else
                    496:        if (1)
                    497: #endif
                    498:        {
                    499:                if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
                    500:                                   PFIL_IN) != 0)
1.121     thorpej   501:                return;
1.127     itojun    502:                if (m == NULL)
                    503:                        return;
                    504:                ip = mtod(m, struct ip *);
                    505:        }
1.36      mrg       506: #endif /* PFIL_HOOKS */
1.123     thorpej   507:
                    508: #ifdef ALTQ
                    509:        /* XXX Temporary until ALTQ is changed to use a pfil hook */
                    510:        if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
                    511:                /* packet dropped by traffic conditioner */
                    512:                return;
                    513:        }
                    514: #endif
1.121     thorpej   515:
                    516:        /*
                    517:         * Convert fields to host representation.
                    518:         */
                    519:        NTOHS(ip->ip_len);
                    520:        NTOHS(ip->ip_off);
1.33      mrg       521:
1.1       cgd       522:        /*
                    523:         * Process options and, if not destined for us,
                    524:         * ship it on.  ip_dooptions returns 1 when an
                    525:         * error was detected (causing an icmp message
                    526:         * to be sent and the original packet to be freed).
                    527:         */
                    528:        ip_nhops = 0;           /* for source routed packets */
                    529:        if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.89      itojun    530:                return;
1.1       cgd       531:
                    532:        /*
                    533:         * Check our list of addresses, to see if the packet is for us.
1.100     itojun    534:         *
                    535:         * Traditional 4.4BSD did not consult IFF_UP at all.
                    536:         * The behavior here is to treat addresses on !IFF_UP interface
                    537:         * as not mine.
1.1       cgd       538:         */
1.100     itojun    539:        downmatch = 0;
1.97      itojun    540:        for (ia = IN_IFADDR_HASH(ip->ip_dst.s_addr).lh_first;
                    541:             ia != NULL;
                    542:             ia = ia->ia_hash.le_next) {
                    543:                if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
                    544:                        if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
                    545:                                break;
1.100     itojun    546:                        else
                    547:                                downmatch++;
1.97      itojun    548:                }
                    549:        }
1.86      thorpej   550:        if (ia != NULL)
                    551:                goto ours;
1.57      tls       552:        if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
                    553:                for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
                    554:                    ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
                    555:                        if (ifa->ifa_addr->sa_family != AF_INET) continue;
                    556:                        ia = ifatoia(ifa);
1.35      mycroft   557:                        if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
                    558:                            in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20      mycroft   559:                            /*
                    560:                             * Look for all-0's host part (old broadcast addr),
                    561:                             * either for subnet or net.
                    562:                             */
                    563:                            ip->ip_dst.s_addr == ia->ia_subnet ||
1.18      mycroft   564:                            ip->ip_dst.s_addr == ia->ia_net)
1.1       cgd       565:                                goto ours;
1.57      tls       566:                        /*
                    567:                         * An interface with IP address zero accepts
                    568:                         * all packets that arrive on that interface.
                    569:                         */
                    570:                        if (in_nullhost(ia->ia_addr.sin_addr))
                    571:                                goto ours;
1.1       cgd       572:                }
                    573:        }
1.18      mycroft   574:        if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4       hpeyerl   575:                struct in_multi *inm;
                    576: #ifdef MROUTING
                    577:                extern struct socket *ip_mrouter;
1.10      brezak    578:
                    579:                if (m->m_flags & M_EXT) {
                    580:                        if ((m = m_pullup(m, hlen)) == 0) {
                    581:                                ipstat.ips_toosmall++;
1.89      itojun    582:                                return;
1.10      brezak    583:                        }
                    584:                        ip = mtod(m, struct ip *);
                    585:                }
1.4       hpeyerl   586:
                    587:                if (ip_mrouter) {
                    588:                        /*
                    589:                         * If we are acting as a multicast router, all
                    590:                         * incoming multicast packets are passed to the
                    591:                         * kernel-level multicast forwarding function.
                    592:                         * The packet is returned (relatively) intact; if
                    593:                         * ip_mforward() returns a non-zero value, the packet
                    594:                         * must be discarded, else it may be accepted below.
                    595:                         *
                    596:                         * (The IP ident field is put in the same byte order
                    597:                         * as expected when ip_mforward() is called from
                    598:                         * ip_output().)
                    599:                         */
1.13      mycroft   600:                        if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
                    601:                                ipstat.ips_cantforward++;
1.4       hpeyerl   602:                                m_freem(m);
1.89      itojun    603:                                return;
1.4       hpeyerl   604:                        }
                    605:
                    606:                        /*
                    607:                         * The process-level routing demon needs to receive
                    608:                         * all multicast IGMP packets, whether or not this
                    609:                         * host belongs to their destination groups.
                    610:                         */
                    611:                        if (ip->ip_p == IPPROTO_IGMP)
                    612:                                goto ours;
1.13      mycroft   613:                        ipstat.ips_forward++;
1.4       hpeyerl   614:                }
                    615: #endif
                    616:                /*
                    617:                 * See if we belong to the destination multicast group on the
                    618:                 * arrival interface.
                    619:                 */
                    620:                IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
                    621:                if (inm == NULL) {
1.13      mycroft   622:                        ipstat.ips_cantforward++;
1.4       hpeyerl   623:                        m_freem(m);
1.89      itojun    624:                        return;
1.4       hpeyerl   625:                }
                    626:                goto ours;
                    627:        }
1.19      mycroft   628:        if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35      mycroft   629:            in_nullhost(ip->ip_dst))
1.1       cgd       630:                goto ours;
                    631:
                    632:        /*
                    633:         * Not for us; forward if possible and desirable.
                    634:         */
                    635:        if (ipforwarding == 0) {
                    636:                ipstat.ips_cantforward++;
                    637:                m_freem(m);
1.100     itojun    638:        } else {
                    639:                /*
                    640:                 * If ip_dst matched any of my address on !IFF_UP interface,
                    641:                 * and there's no IFF_UP interface that matches ip_dst,
                    642:                 * send icmp unreach.  Forwarding it will result in in-kernel
                    643:                 * forwarding loop till TTL goes to 0.
                    644:                 */
                    645:                if (downmatch) {
                    646:                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
                    647:                        ipstat.ips_cantforward++;
                    648:                        return;
                    649:                }
1.1       cgd       650:                ip_forward(m, 0);
1.100     itojun    651:        }
1.89      itojun    652:        return;
1.1       cgd       653:
                    654: ours:
                    655:        /*
                    656:         * If offset or IP_MF are set, must reassemble.
                    657:         * Otherwise, nothing need be done.
                    658:         * (We could look in the reassembly queue to see
                    659:         * if the packet was previously fragmented,
                    660:         * but it's not worth the time; just let them time out.)
                    661:         */
1.37      perry     662:        if (ip->ip_off & ~(IP_DF|IP_RF)) {
1.1       cgd       663:                /*
                    664:                 * Look for queue of fragments
                    665:                 * of this datagram.
                    666:                 */
1.75      thorpej   667:                IPQ_LOCK();
1.25      cgd       668:                for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
1.1       cgd       669:                        if (ip->ip_id == fp->ipq_id &&
1.35      mycroft   670:                            in_hosteq(ip->ip_src, fp->ipq_src) &&
                    671:                            in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1       cgd       672:                            ip->ip_p == fp->ipq_p)
                    673:                                goto found;
                    674:                fp = 0;
                    675: found:
                    676:
                    677:                /*
                    678:                 * Adjust ip_len to not reflect header,
1.25      cgd       679:                 * set ipqe_mff if more fragments are expected,
1.1       cgd       680:                 * convert offset of this to bytes.
                    681:                 */
                    682:                ip->ip_len -= hlen;
1.25      cgd       683:                mff = (ip->ip_off & IP_MF) != 0;
                    684:                if (mff) {
1.16      cgd       685:                        /*
                    686:                         * Make sure that fragments have a data length
                    687:                         * that's a non-zero multiple of 8 bytes.
                    688:                         */
1.17      cgd       689:                        if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1.16      cgd       690:                                ipstat.ips_badfrags++;
1.75      thorpej   691:                                IPQ_UNLOCK();
1.16      cgd       692:                                goto bad;
                    693:                        }
                    694:                }
1.1       cgd       695:                ip->ip_off <<= 3;
                    696:
                    697:                /*
                    698:                 * If datagram marked as having more fragments
                    699:                 * or if this is not the first fragment,
                    700:                 * attempt reassembly; if it succeeds, proceed.
                    701:                 */
1.25      cgd       702:                if (mff || ip->ip_off) {
1.1       cgd       703:                        ipstat.ips_fragments++;
1.72      thorpej   704:                        ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25      cgd       705:                        if (ipqe == NULL) {
                    706:                                ipstat.ips_rcvmemdrop++;
1.75      thorpej   707:                                IPQ_UNLOCK();
1.25      cgd       708:                                goto bad;
                    709:                        }
                    710:                        ipqe->ipqe_mff = mff;
1.50      thorpej   711:                        ipqe->ipqe_m = m;
1.25      cgd       712:                        ipqe->ipqe_ip = ip;
1.50      thorpej   713:                        m = ip_reass(ipqe, fp);
1.75      thorpej   714:                        if (m == 0) {
                    715:                                IPQ_UNLOCK();
1.89      itojun    716:                                return;
1.75      thorpej   717:                        }
1.13      mycroft   718:                        ipstat.ips_reassembled++;
1.50      thorpej   719:                        ip = mtod(m, struct ip *);
1.74      thorpej   720:                        hlen = ip->ip_hl << 2;
1.79      mycroft   721:                        ip->ip_len += hlen;
1.1       cgd       722:                } else
                    723:                        if (fp)
                    724:                                ip_freef(fp);
1.75      thorpej   725:                IPQ_UNLOCK();
1.79      mycroft   726:        }
1.128     itojun    727:
                    728: #ifdef IPSEC
                    729:        /*
                    730:         * enforce IPsec policy checking if we are seeing last header.
                    731:         * note that we do not visit this with protocols with pcb layer
                    732:         * code - like udp/tcp/raw ip.
                    733:         */
                    734:        if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
                    735:            ipsec4_in_reject(m, NULL)) {
                    736:                ipsecstat.in_polvio++;
                    737:                goto bad;
                    738:        }
                    739: #endif
1.1       cgd       740:
                    741:        /*
                    742:         * Switch out to protocol's input routine.
                    743:         */
1.82      aidan     744: #if IFA_STATS
1.122     itojun    745:        if (ia && ip)
                    746:                ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
1.82      aidan     747: #endif
1.1       cgd       748:        ipstat.ips_delivered++;
1.89      itojun    749:     {
                    750:        int off = hlen, nh = ip->ip_p;
                    751:
                    752:        (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
                    753:        return;
                    754:     }
1.1       cgd       755: bad:
                    756:        m_freem(m);
                    757: }
                    758:
                    759: /*
                    760:  * Take incoming datagram fragment and try to
                    761:  * reassemble it into whole datagram.  If a chain for
                    762:  * reassembly of this datagram already exists, then it
                    763:  * is given as fp; otherwise have to make a chain.
                    764:  */
1.50      thorpej   765: struct mbuf *
1.25      cgd       766: ip_reass(ipqe, fp)
1.109     augustss  767:        struct ipqent *ipqe;
                    768:        struct ipq *fp;
1.1       cgd       769: {
1.109     augustss  770:        struct mbuf *m = ipqe->ipqe_m;
                    771:        struct ipqent *nq, *p, *q;
1.25      cgd       772:        struct ip *ip;
1.1       cgd       773:        struct mbuf *t;
1.25      cgd       774:        int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1       cgd       775:        int i, next;
                    776:
1.75      thorpej   777:        IPQ_LOCK_CHECK();
                    778:
1.1       cgd       779:        /*
                    780:         * Presence of header sizes in mbufs
                    781:         * would confuse code below.
                    782:         */
                    783:        m->m_data += hlen;
                    784:        m->m_len -= hlen;
                    785:
                    786:        /*
                    787:         * If first fragment to arrive, create a reassembly queue.
                    788:         */
                    789:        if (fp == 0) {
1.131     itojun    790:                /*
                    791:                 * Enforce upper bound on number of fragmented packets
                    792:                 * for which we attempt reassembly;
                    793:                 * If maxfrag is 0, never accept fragments.
                    794:                 * If maxfrag is -1, accept all fragments without limitation.
                    795:                 */
                    796:                if (ip_maxfragpackets < 0)
                    797:                        ;
                    798:                else if (ip_nfragpackets >= ip_maxfragpackets)
                    799:                        goto dropfrag;
                    800:                ip_nfragpackets++;
1.50      thorpej   801:                MALLOC(fp, struct ipq *, sizeof (struct ipq),
                    802:                    M_FTABLE, M_NOWAIT);
                    803:                if (fp == NULL)
1.1       cgd       804:                        goto dropfrag;
1.25      cgd       805:                LIST_INSERT_HEAD(&ipq, fp, ipq_q);
1.1       cgd       806:                fp->ipq_ttl = IPFRAGTTL;
1.25      cgd       807:                fp->ipq_p = ipqe->ipqe_ip->ip_p;
                    808:                fp->ipq_id = ipqe->ipqe_ip->ip_id;
                    809:                LIST_INIT(&fp->ipq_fragq);
                    810:                fp->ipq_src = ipqe->ipqe_ip->ip_src;
                    811:                fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
                    812:                p = NULL;
1.1       cgd       813:                goto insert;
                    814:        }
                    815:
                    816:        /*
                    817:         * Find a segment which begins after this one does.
                    818:         */
1.25      cgd       819:        for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
                    820:            p = q, q = q->ipqe_q.le_next)
                    821:                if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
1.1       cgd       822:                        break;
                    823:
                    824:        /*
                    825:         * If there is a preceding segment, it may provide some of
                    826:         * our data already.  If so, drop the data from the incoming
                    827:         * segment.  If it provides all of our data, drop us.
                    828:         */
1.25      cgd       829:        if (p != NULL) {
                    830:                i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
                    831:                    ipqe->ipqe_ip->ip_off;
1.1       cgd       832:                if (i > 0) {
1.25      cgd       833:                        if (i >= ipqe->ipqe_ip->ip_len)
1.1       cgd       834:                                goto dropfrag;
1.50      thorpej   835:                        m_adj(ipqe->ipqe_m, i);
1.25      cgd       836:                        ipqe->ipqe_ip->ip_off += i;
                    837:                        ipqe->ipqe_ip->ip_len -= i;
1.1       cgd       838:                }
                    839:        }
                    840:
                    841:        /*
                    842:         * While we overlap succeeding segments trim them or,
                    843:         * if they are completely covered, dequeue them.
                    844:         */
1.25      cgd       845:        for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
                    846:            q->ipqe_ip->ip_off; q = nq) {
                    847:                i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
                    848:                    q->ipqe_ip->ip_off;
                    849:                if (i < q->ipqe_ip->ip_len) {
                    850:                        q->ipqe_ip->ip_len -= i;
                    851:                        q->ipqe_ip->ip_off += i;
1.50      thorpej   852:                        m_adj(q->ipqe_m, i);
1.1       cgd       853:                        break;
                    854:                }
1.25      cgd       855:                nq = q->ipqe_q.le_next;
1.50      thorpej   856:                m_freem(q->ipqe_m);
1.25      cgd       857:                LIST_REMOVE(q, ipqe_q);
1.72      thorpej   858:                pool_put(&ipqent_pool, q);
1.1       cgd       859:        }
                    860:
                    861: insert:
                    862:        /*
                    863:         * Stick new segment in its place;
                    864:         * check for complete reassembly.
                    865:         */
1.25      cgd       866:        if (p == NULL) {
                    867:                LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
                    868:        } else {
                    869:                LIST_INSERT_AFTER(p, ipqe, ipqe_q);
                    870:        }
1.1       cgd       871:        next = 0;
1.25      cgd       872:        for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
                    873:            p = q, q = q->ipqe_q.le_next) {
                    874:                if (q->ipqe_ip->ip_off != next)
1.1       cgd       875:                        return (0);
1.25      cgd       876:                next += q->ipqe_ip->ip_len;
1.1       cgd       877:        }
1.25      cgd       878:        if (p->ipqe_mff)
1.1       cgd       879:                return (0);
                    880:
                    881:        /*
1.41      thorpej   882:         * Reassembly is complete.  Check for a bogus message size and
                    883:         * concatenate fragments.
1.1       cgd       884:         */
1.25      cgd       885:        q = fp->ipq_fragq.lh_first;
                    886:        ip = q->ipqe_ip;
1.41      thorpej   887:        if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
                    888:                ipstat.ips_toolong++;
                    889:                ip_freef(fp);
                    890:                return (0);
                    891:        }
1.50      thorpej   892:        m = q->ipqe_m;
1.1       cgd       893:        t = m->m_next;
                    894:        m->m_next = 0;
                    895:        m_cat(m, t);
1.25      cgd       896:        nq = q->ipqe_q.le_next;
1.72      thorpej   897:        pool_put(&ipqent_pool, q);
1.25      cgd       898:        for (q = nq; q != NULL; q = nq) {
1.50      thorpej   899:                t = q->ipqe_m;
1.25      cgd       900:                nq = q->ipqe_q.le_next;
1.72      thorpej   901:                pool_put(&ipqent_pool, q);
1.1       cgd       902:                m_cat(m, t);
                    903:        }
                    904:
                    905:        /*
                    906:         * Create header for new ip packet by
                    907:         * modifying header of first packet;
                    908:         * dequeue and discard fragment reassembly header.
                    909:         * Make header visible.
                    910:         */
                    911:        ip->ip_len = next;
1.25      cgd       912:        ip->ip_src = fp->ipq_src;
                    913:        ip->ip_dst = fp->ipq_dst;
                    914:        LIST_REMOVE(fp, ipq_q);
1.50      thorpej   915:        FREE(fp, M_FTABLE);
1.131     itojun    916:        ip_nfragpackets--;
1.1       cgd       917:        m->m_len += (ip->ip_hl << 2);
                    918:        m->m_data -= (ip->ip_hl << 2);
                    919:        /* some debugging cruft by sklower, below, will go away soon */
                    920:        if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1.109     augustss  921:                int plen = 0;
1.50      thorpej   922:                for (t = m; t; t = t->m_next)
                    923:                        plen += t->m_len;
                    924:                m->m_pkthdr.len = plen;
1.1       cgd       925:        }
1.50      thorpej   926:        return (m);
1.1       cgd       927:
                    928: dropfrag:
                    929:        ipstat.ips_fragdropped++;
                    930:        m_freem(m);
1.72      thorpej   931:        pool_put(&ipqent_pool, ipqe);
1.1       cgd       932:        return (0);
                    933: }
                    934:
                    935: /*
                    936:  * Free a fragment reassembly header and all
                    937:  * associated datagrams.
                    938:  */
1.8       mycroft   939: void
1.1       cgd       940: ip_freef(fp)
                    941:        struct ipq *fp;
                    942: {
1.109     augustss  943:        struct ipqent *q, *p;
1.1       cgd       944:
1.75      thorpej   945:        IPQ_LOCK_CHECK();
                    946:
1.25      cgd       947:        for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
                    948:                p = q->ipqe_q.le_next;
1.50      thorpej   949:                m_freem(q->ipqe_m);
1.25      cgd       950:                LIST_REMOVE(q, ipqe_q);
1.72      thorpej   951:                pool_put(&ipqent_pool, q);
1.1       cgd       952:        }
1.25      cgd       953:        LIST_REMOVE(fp, ipq_q);
1.50      thorpej   954:        FREE(fp, M_FTABLE);
1.131     itojun    955:        ip_nfragpackets--;
1.1       cgd       956: }
                    957:
                    958: /*
                    959:  * IP timer processing;
                    960:  * if a timer expires on a reassembly
                    961:  * queue, discard it.
                    962:  */
1.8       mycroft   963: void
1.1       cgd       964: ip_slowtimo()
                    965: {
1.109     augustss  966:        struct ipq *fp, *nfp;
1.24      mycroft   967:        int s = splsoftnet();
1.1       cgd       968:
1.75      thorpej   969:        IPQ_LOCK();
1.25      cgd       970:        for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
                    971:                nfp = fp->ipq_q.le_next;
                    972:                if (--fp->ipq_ttl == 0) {
1.1       cgd       973:                        ipstat.ips_fragtimeout++;
1.25      cgd       974:                        ip_freef(fp);
1.1       cgd       975:                }
                    976:        }
1.131     itojun    977:        /*
                    978:         * If we are over the maximum number of fragments
                    979:         * (due to the limit being lowered), drain off
                    980:         * enough to get down to the new limit.
                    981:         */
                    982:        if (ip_maxfragpackets < 0)
                    983:                ;
                    984:        else {
                    985:                while (ip_nfragpackets > ip_maxfragpackets && ipq.lh_first)
                    986:                        ip_freef(ipq.lh_first);
                    987:        }
1.75      thorpej   988:        IPQ_UNLOCK();
1.63      matt      989: #ifdef GATEWAY
                    990:        ipflow_slowtimo();
                    991: #endif
1.1       cgd       992:        splx(s);
                    993: }
                    994:
                    995: /*
                    996:  * Drain off all datagram fragments.
                    997:  */
1.8       mycroft   998: void
1.1       cgd       999: ip_drain()
                   1000: {
                   1001:
1.75      thorpej  1002:        /*
                   1003:         * We may be called from a device's interrupt context.  If
                   1004:         * the ipq is already busy, just bail out now.
                   1005:         */
                   1006:        if (ipq_lock_try() == 0)
                   1007:                return;
                   1008:
1.25      cgd      1009:        while (ipq.lh_first != NULL) {
1.1       cgd      1010:                ipstat.ips_fragdropped++;
1.25      cgd      1011:                ip_freef(ipq.lh_first);
1.1       cgd      1012:        }
1.75      thorpej  1013:
                   1014:        IPQ_UNLOCK();
1.1       cgd      1015: }
                   1016:
                   1017: /*
                   1018:  * Do option processing on a datagram,
                   1019:  * possibly discarding it if bad options are encountered,
                   1020:  * or forwarding it if source-routed.
                   1021:  * Returns 1 if packet has been forwarded/freed,
                   1022:  * 0 if the packet should be processed further.
                   1023:  */
1.8       mycroft  1024: int
1.1       cgd      1025: ip_dooptions(m)
                   1026:        struct mbuf *m;
                   1027: {
1.109     augustss 1028:        struct ip *ip = mtod(m, struct ip *);
                   1029:        u_char *cp, *cp0;
                   1030:        struct ip_timestamp *ipt;
                   1031:        struct in_ifaddr *ia;
1.1       cgd      1032:        int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.104     thorpej  1033:        struct in_addr dst;
1.1       cgd      1034:        n_time ntime;
                   1035:
1.13      mycroft  1036:        dst = ip->ip_dst;
1.1       cgd      1037:        cp = (u_char *)(ip + 1);
                   1038:        cnt = (ip->ip_hl << 2) - sizeof (struct ip);
                   1039:        for (; cnt > 0; cnt -= optlen, cp += optlen) {
                   1040:                opt = cp[IPOPT_OPTVAL];
                   1041:                if (opt == IPOPT_EOL)
                   1042:                        break;
                   1043:                if (opt == IPOPT_NOP)
                   1044:                        optlen = 1;
                   1045:                else {
1.113     itojun   1046:                        if (cnt < IPOPT_OLEN + sizeof(*cp)) {
                   1047:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1048:                                goto bad;
                   1049:                        }
1.1       cgd      1050:                        optlen = cp[IPOPT_OLEN];
1.114     itojun   1051:                        if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1.1       cgd      1052:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1053:                                goto bad;
                   1054:                        }
                   1055:                }
                   1056:                switch (opt) {
                   1057:
                   1058:                default:
                   1059:                        break;
                   1060:
                   1061:                /*
                   1062:                 * Source routing with record.
                   1063:                 * Find interface with current destination address.
                   1064:                 * If none on this machine then drop if strictly routed,
                   1065:                 * or do nothing if loosely routed.
                   1066:                 * Record interface address and bring up next address
                   1067:                 * component.  If strictly routed make sure next
                   1068:                 * address is on directly accessible net.
                   1069:                 */
                   1070:                case IPOPT_LSRR:
                   1071:                case IPOPT_SSRR:
1.47      cjs      1072:                        if (ip_allowsrcrt == 0) {
                   1073:                                type = ICMP_UNREACH;
                   1074:                                code = ICMP_UNREACH_NET_PROHIB;
                   1075:                                goto bad;
                   1076:                        }
1.114     itojun   1077:                        if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
                   1078:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1079:                                goto bad;
                   1080:                        }
1.1       cgd      1081:                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                   1082:                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                   1083:                                goto bad;
                   1084:                        }
                   1085:                        ipaddr.sin_addr = ip->ip_dst;
1.19      mycroft  1086:                        ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1       cgd      1087:                        if (ia == 0) {
                   1088:                                if (opt == IPOPT_SSRR) {
                   1089:                                        type = ICMP_UNREACH;
                   1090:                                        code = ICMP_UNREACH_SRCFAIL;
                   1091:                                        goto bad;
                   1092:                                }
                   1093:                                /*
                   1094:                                 * Loose routing, and not at next destination
                   1095:                                 * yet; nothing to do except forward.
                   1096:                                 */
                   1097:                                break;
                   1098:                        }
                   1099:                        off--;                  /* 0 origin */
1.112     sommerfe 1100:                        if ((off + sizeof(struct in_addr)) > optlen) {
1.1       cgd      1101:                                /*
                   1102:                                 * End of source route.  Should be for us.
                   1103:                                 */
                   1104:                                save_rte(cp, ip->ip_src);
                   1105:                                break;
                   1106:                        }
                   1107:                        /*
                   1108:                         * locate outgoing interface
                   1109:                         */
                   1110:                        bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
                   1111:                            sizeof(ipaddr.sin_addr));
1.96      thorpej  1112:                        if (opt == IPOPT_SSRR)
                   1113:                                ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
                   1114:                        else
1.1       cgd      1115:                                ia = ip_rtaddr(ipaddr.sin_addr);
                   1116:                        if (ia == 0) {
                   1117:                                type = ICMP_UNREACH;
                   1118:                                code = ICMP_UNREACH_SRCFAIL;
                   1119:                                goto bad;
                   1120:                        }
                   1121:                        ip->ip_dst = ipaddr.sin_addr;
1.20      mycroft  1122:                        bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd      1123:                            (caddr_t)(cp + off), sizeof(struct in_addr));
                   1124:                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13      mycroft  1125:                        /*
                   1126:                         * Let ip_intr's mcast routing check handle mcast pkts
                   1127:                         */
1.18      mycroft  1128:                        forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1       cgd      1129:                        break;
                   1130:
                   1131:                case IPOPT_RR:
1.114     itojun   1132:                        if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
                   1133:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1134:                                goto bad;
                   1135:                        }
1.1       cgd      1136:                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                   1137:                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                   1138:                                goto bad;
                   1139:                        }
                   1140:                        /*
                   1141:                         * If no space remains, ignore.
                   1142:                         */
                   1143:                        off--;                  /* 0 origin */
1.112     sommerfe 1144:                        if ((off + sizeof(struct in_addr)) > optlen)
1.1       cgd      1145:                                break;
                   1146:                        bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
                   1147:                            sizeof(ipaddr.sin_addr));
                   1148:                        /*
                   1149:                         * locate outgoing interface; if we're the destination,
                   1150:                         * use the incoming interface (should be same).
                   1151:                         */
1.96      thorpej  1152:                        if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
                   1153:                            == NULL &&
                   1154:                            (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1.1       cgd      1155:                                type = ICMP_UNREACH;
                   1156:                                code = ICMP_UNREACH_HOST;
                   1157:                                goto bad;
                   1158:                        }
1.20      mycroft  1159:                        bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd      1160:                            (caddr_t)(cp + off), sizeof(struct in_addr));
                   1161:                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
                   1162:                        break;
                   1163:
                   1164:                case IPOPT_TS:
                   1165:                        code = cp - (u_char *)ip;
                   1166:                        ipt = (struct ip_timestamp *)cp;
1.114     itojun   1167:                        if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
                   1168:                                code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1.1       cgd      1169:                                goto bad;
1.114     itojun   1170:                        }
                   1171:                        if (ipt->ipt_ptr < 5) {
                   1172:                                code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
                   1173:                                goto bad;
                   1174:                        }
1.15      cgd      1175:                        if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.114     itojun   1176:                                if (++ipt->ipt_oflw == 0) {
                   1177:                                        code = (u_char *)&ipt->ipt_ptr -
                   1178:                                            (u_char *)ip;
1.1       cgd      1179:                                        goto bad;
1.114     itojun   1180:                                }
1.1       cgd      1181:                                break;
                   1182:                        }
1.104     thorpej  1183:                        cp0 = (cp + ipt->ipt_ptr - 1);
1.1       cgd      1184:                        switch (ipt->ipt_flg) {
                   1185:
                   1186:                        case IPOPT_TS_TSONLY:
                   1187:                                break;
                   1188:
                   1189:                        case IPOPT_TS_TSANDADDR:
1.66      thorpej  1190:                                if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114     itojun   1191:                                    sizeof(struct in_addr) > ipt->ipt_len) {
                   1192:                                        code = (u_char *)&ipt->ipt_ptr -
                   1193:                                            (u_char *)ip;
1.1       cgd      1194:                                        goto bad;
1.114     itojun   1195:                                }
1.13      mycroft  1196:                                ipaddr.sin_addr = dst;
1.96      thorpej  1197:                                ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
                   1198:                                    m->m_pkthdr.rcvif));
1.13      mycroft  1199:                                if (ia == 0)
                   1200:                                        continue;
1.104     thorpej  1201:                                bcopy(&ia->ia_addr.sin_addr,
                   1202:                                    cp0, sizeof(struct in_addr));
1.1       cgd      1203:                                ipt->ipt_ptr += sizeof(struct in_addr);
                   1204:                                break;
                   1205:
                   1206:                        case IPOPT_TS_PRESPEC:
1.66      thorpej  1207:                                if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114     itojun   1208:                                    sizeof(struct in_addr) > ipt->ipt_len) {
                   1209:                                        code = (u_char *)&ipt->ipt_ptr -
                   1210:                                            (u_char *)ip;
1.1       cgd      1211:                                        goto bad;
1.114     itojun   1212:                                }
1.104     thorpej  1213:                                bcopy(cp0, &ipaddr.sin_addr,
1.1       cgd      1214:                                    sizeof(struct in_addr));
1.96      thorpej  1215:                                if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
                   1216:                                    == NULL)
1.1       cgd      1217:                                        continue;
                   1218:                                ipt->ipt_ptr += sizeof(struct in_addr);
                   1219:                                break;
                   1220:
                   1221:                        default:
1.114     itojun   1222:                                /* XXX can't take &ipt->ipt_flg */
                   1223:                                code = (u_char *)&ipt->ipt_ptr -
                   1224:                                    (u_char *)ip + 1;
1.1       cgd      1225:                                goto bad;
                   1226:                        }
                   1227:                        ntime = iptime();
1.107     thorpej  1228:                        cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
                   1229:                        bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1,
1.1       cgd      1230:                            sizeof(n_time));
                   1231:                        ipt->ipt_ptr += sizeof(n_time);
                   1232:                }
                   1233:        }
                   1234:        if (forward) {
1.26      thorpej  1235:                if (ip_forwsrcrt == 0) {
                   1236:                        type = ICMP_UNREACH;
                   1237:                        code = ICMP_UNREACH_SRCFAIL;
                   1238:                        goto bad;
                   1239:                }
1.1       cgd      1240:                ip_forward(m, 1);
                   1241:                return (1);
1.13      mycroft  1242:        }
                   1243:        return (0);
1.1       cgd      1244: bad:
1.13      mycroft  1245:        icmp_error(m, type, code, 0, 0);
                   1246:        ipstat.ips_badoptions++;
1.1       cgd      1247:        return (1);
                   1248: }
                   1249:
                   1250: /*
                   1251:  * Given address of next destination (final or next hop),
                   1252:  * return internet address info of interface to be used to get there.
                   1253:  */
                   1254: struct in_ifaddr *
                   1255: ip_rtaddr(dst)
                   1256:         struct in_addr dst;
                   1257: {
1.109     augustss 1258:        struct sockaddr_in *sin;
1.1       cgd      1259:
1.19      mycroft  1260:        sin = satosin(&ipforward_rt.ro_dst);
1.1       cgd      1261:
1.35      mycroft  1262:        if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1       cgd      1263:                if (ipforward_rt.ro_rt) {
                   1264:                        RTFREE(ipforward_rt.ro_rt);
                   1265:                        ipforward_rt.ro_rt = 0;
                   1266:                }
                   1267:                sin->sin_family = AF_INET;
                   1268:                sin->sin_len = sizeof(*sin);
                   1269:                sin->sin_addr = dst;
                   1270:
                   1271:                rtalloc(&ipforward_rt);
                   1272:        }
                   1273:        if (ipforward_rt.ro_rt == 0)
                   1274:                return ((struct in_ifaddr *)0);
1.19      mycroft  1275:        return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1       cgd      1276: }
                   1277:
                   1278: /*
                   1279:  * Save incoming source route for use in replies,
                   1280:  * to be picked up later by ip_srcroute if the receiver is interested.
                   1281:  */
1.13      mycroft  1282: void
1.1       cgd      1283: save_rte(option, dst)
                   1284:        u_char *option;
                   1285:        struct in_addr dst;
                   1286: {
                   1287:        unsigned olen;
                   1288:
                   1289:        olen = option[IPOPT_OLEN];
                   1290: #ifdef DIAGNOSTIC
                   1291:        if (ipprintfs)
1.39      christos 1292:                printf("save_rte: olen %d\n", olen);
1.89      itojun   1293: #endif /* 0 */
1.1       cgd      1294:        if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
                   1295:                return;
                   1296:        bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
                   1297:        ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
                   1298:        ip_srcrt.dst = dst;
                   1299: }
                   1300:
                   1301: /*
                   1302:  * Retrieve incoming source route for use in replies,
                   1303:  * in the same form used by setsockopt.
                   1304:  * The first hop is placed before the options, will be removed later.
                   1305:  */
                   1306: struct mbuf *
                   1307: ip_srcroute()
                   1308: {
1.109     augustss 1309:        struct in_addr *p, *q;
                   1310:        struct mbuf *m;
1.1       cgd      1311:
                   1312:        if (ip_nhops == 0)
                   1313:                return ((struct mbuf *)0);
                   1314:        m = m_get(M_DONTWAIT, MT_SOOPTS);
                   1315:        if (m == 0)
                   1316:                return ((struct mbuf *)0);
                   1317:
1.13      mycroft  1318: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1       cgd      1319:
                   1320:        /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
                   1321:        m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
                   1322:            OPTSIZ;
                   1323: #ifdef DIAGNOSTIC
                   1324:        if (ipprintfs)
1.39      christos 1325:                printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1       cgd      1326: #endif
                   1327:
                   1328:        /*
                   1329:         * First save first hop for return route
                   1330:         */
                   1331:        p = &ip_srcrt.route[ip_nhops - 1];
                   1332:        *(mtod(m, struct in_addr *)) = *p--;
                   1333: #ifdef DIAGNOSTIC
                   1334:        if (ipprintfs)
1.39      christos 1335:                printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1       cgd      1336: #endif
                   1337:
                   1338:        /*
                   1339:         * Copy option fields and padding (nop) to mbuf.
                   1340:         */
                   1341:        ip_srcrt.nop = IPOPT_NOP;
                   1342:        ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
                   1343:        bcopy((caddr_t)&ip_srcrt.nop,
                   1344:            mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
                   1345:        q = (struct in_addr *)(mtod(m, caddr_t) +
                   1346:            sizeof(struct in_addr) + OPTSIZ);
                   1347: #undef OPTSIZ
                   1348:        /*
                   1349:         * Record return path as an IP source route,
                   1350:         * reversing the path (pointers are now aligned).
                   1351:         */
                   1352:        while (p >= ip_srcrt.route) {
                   1353: #ifdef DIAGNOSTIC
                   1354:                if (ipprintfs)
1.39      christos 1355:                        printf(" %x", ntohl(q->s_addr));
1.1       cgd      1356: #endif
                   1357:                *q++ = *p--;
                   1358:        }
                   1359:        /*
                   1360:         * Last hop goes to final destination.
                   1361:         */
                   1362:        *q = ip_srcrt.dst;
                   1363: #ifdef DIAGNOSTIC
                   1364:        if (ipprintfs)
1.39      christos 1365:                printf(" %x\n", ntohl(q->s_addr));
1.1       cgd      1366: #endif
                   1367:        return (m);
                   1368: }
                   1369:
                   1370: /*
                   1371:  * Strip out IP options, at higher
                   1372:  * level protocol in the kernel.
                   1373:  * Second argument is buffer to which options
                   1374:  * will be moved, and return value is their length.
                   1375:  * XXX should be deleted; last arg currently ignored.
                   1376:  */
1.8       mycroft  1377: void
1.1       cgd      1378: ip_stripoptions(m, mopt)
1.109     augustss 1379:        struct mbuf *m;
1.1       cgd      1380:        struct mbuf *mopt;
                   1381: {
1.109     augustss 1382:        int i;
1.1       cgd      1383:        struct ip *ip = mtod(m, struct ip *);
1.109     augustss 1384:        caddr_t opts;
1.1       cgd      1385:        int olen;
                   1386:
1.79      mycroft  1387:        olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1       cgd      1388:        opts = (caddr_t)(ip + 1);
                   1389:        i = m->m_len - (sizeof (struct ip) + olen);
                   1390:        bcopy(opts  + olen, opts, (unsigned)i);
                   1391:        m->m_len -= olen;
                   1392:        if (m->m_flags & M_PKTHDR)
                   1393:                m->m_pkthdr.len -= olen;
1.79      mycroft  1394:        ip->ip_len -= olen;
                   1395:        ip->ip_hl = sizeof (struct ip) >> 2;
1.1       cgd      1396: }
                   1397:
1.23      mycroft  1398: int inetctlerrmap[PRC_NCMDS] = {
1.1       cgd      1399:        0,              0,              0,              0,
                   1400:        0,              EMSGSIZE,       EHOSTDOWN,      EHOSTUNREACH,
                   1401:        EHOSTUNREACH,   EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
                   1402:        EMSGSIZE,       EHOSTUNREACH,   0,              0,
                   1403:        0,              0,              0,              0,
                   1404:        ENOPROTOOPT
                   1405: };
                   1406:
                   1407: /*
                   1408:  * Forward a packet.  If some error occurs return the sender
                   1409:  * an icmp packet.  Note we can't always generate a meaningful
                   1410:  * icmp message because icmp doesn't have a large enough repertoire
                   1411:  * of codes and types.
                   1412:  *
                   1413:  * If not forwarding, just drop the packet.  This could be confusing
                   1414:  * if ipforwarding was zero but some routing protocol was advancing
                   1415:  * us as a gateway to somewhere.  However, we must let the routing
                   1416:  * protocol deal with that.
                   1417:  *
                   1418:  * The srcrt parameter indicates whether the packet is being forwarded
                   1419:  * via a source route.
                   1420:  */
1.13      mycroft  1421: void
1.1       cgd      1422: ip_forward(m, srcrt)
                   1423:        struct mbuf *m;
                   1424:        int srcrt;
                   1425: {
1.109     augustss 1426:        struct ip *ip = mtod(m, struct ip *);
                   1427:        struct sockaddr_in *sin;
                   1428:        struct rtentry *rt;
1.28      christos 1429:        int error, type = 0, code = 0;
1.1       cgd      1430:        struct mbuf *mcopy;
1.13      mycroft  1431:        n_long dest;
                   1432:        struct ifnet *destifp;
1.89      itojun   1433: #ifdef IPSEC
                   1434:        struct ifnet dummyifp;
                   1435: #endif
1.1       cgd      1436:
1.13      mycroft  1437:        dest = 0;
1.1       cgd      1438: #ifdef DIAGNOSTIC
                   1439:        if (ipprintfs)
1.70      thorpej  1440:                printf("forward: src %2.2x dst %2.2x ttl %x\n",
                   1441:                    ntohl(ip->ip_src.s_addr),
                   1442:                    ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1       cgd      1443: #endif
1.93      sommerfe 1444:        if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1.1       cgd      1445:                ipstat.ips_cantforward++;
                   1446:                m_freem(m);
                   1447:                return;
                   1448:        }
                   1449:        if (ip->ip_ttl <= IPTTLDEC) {
1.13      mycroft  1450:                icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1       cgd      1451:                return;
                   1452:        }
                   1453:        ip->ip_ttl -= IPTTLDEC;
                   1454:
1.19      mycroft  1455:        sin = satosin(&ipforward_rt.ro_dst);
1.1       cgd      1456:        if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35      mycroft  1457:            !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1       cgd      1458:                if (ipforward_rt.ro_rt) {
                   1459:                        RTFREE(ipforward_rt.ro_rt);
                   1460:                        ipforward_rt.ro_rt = 0;
                   1461:                }
                   1462:                sin->sin_family = AF_INET;
1.35      mycroft  1463:                sin->sin_len = sizeof(struct sockaddr_in);
1.1       cgd      1464:                sin->sin_addr = ip->ip_dst;
                   1465:
                   1466:                rtalloc(&ipforward_rt);
                   1467:                if (ipforward_rt.ro_rt == 0) {
1.13      mycroft  1468:                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1       cgd      1469:                        return;
                   1470:                }
                   1471:                rt = ipforward_rt.ro_rt;
                   1472:        }
                   1473:
                   1474:        /*
1.34      mycroft  1475:         * Save at most 68 bytes of the packet in case
1.1       cgd      1476:         * we need to generate an ICMP message to the src.
1.119     itojun   1477:         * Pullup to avoid sharing mbuf cluster between m and mcopy.
1.1       cgd      1478:         */
1.119     itojun   1479:        mcopy = m_copym(m, 0, imin((int)ip->ip_len, 68), M_DONTWAIT);
                   1480:        if (mcopy)
                   1481:                mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1.1       cgd      1482:
                   1483:        /*
                   1484:         * If forwarding packet using same interface that it came in on,
                   1485:         * perhaps should send a redirect to sender to shortcut a hop.
                   1486:         * Only send redirect if source is sending directly to us,
                   1487:         * and if packet was not source routed (or has any options).
                   1488:         * Also, don't send redirect if forwarding using a default route
                   1489:         * or a route modified by a redirect.
                   1490:         */
                   1491:        if (rt->rt_ifp == m->m_pkthdr.rcvif &&
                   1492:            (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35      mycroft  1493:            !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1       cgd      1494:            ipsendredirects && !srcrt) {
1.19      mycroft  1495:                if (rt->rt_ifa &&
                   1496:                    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
                   1497:                    ifatoia(rt->rt_ifa)->ia_subnet) {
1.77      thorpej  1498:                        if (rt->rt_flags & RTF_GATEWAY)
                   1499:                                dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
                   1500:                        else
                   1501:                                dest = ip->ip_dst.s_addr;
                   1502:                        /*
                   1503:                         * Router requirements says to only send host
                   1504:                         * redirects.
                   1505:                         */
                   1506:                        type = ICMP_REDIRECT;
                   1507:                        code = ICMP_REDIRECT_HOST;
1.1       cgd      1508: #ifdef DIAGNOSTIC
1.77      thorpej  1509:                        if (ipprintfs)
                   1510:                                printf("redirect (%d) to %x\n", code,
                   1511:                                    (u_int32_t)dest);
1.1       cgd      1512: #endif
                   1513:                }
                   1514:        }
                   1515:
1.89      itojun   1516: #ifdef IPSEC
1.103     itojun   1517:        /* Don't lookup socket in forwading case */
1.127     itojun   1518:        (void)ipsec_setsocket(m, NULL);
1.103     itojun   1519: #endif
1.27      thorpej  1520:        error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
                   1521:            (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
1.1       cgd      1522:        if (error)
                   1523:                ipstat.ips_cantforward++;
                   1524:        else {
                   1525:                ipstat.ips_forward++;
                   1526:                if (type)
                   1527:                        ipstat.ips_redirectsent++;
                   1528:                else {
1.63      matt     1529:                        if (mcopy) {
                   1530: #ifdef GATEWAY
1.64      thorpej  1531:                                if (mcopy->m_flags & M_CANFASTFWD)
                   1532:                                        ipflow_create(&ipforward_rt, mcopy);
1.63      matt     1533: #endif
1.1       cgd      1534:                                m_freem(mcopy);
1.63      matt     1535:                        }
1.1       cgd      1536:                        return;
                   1537:                }
                   1538:        }
                   1539:        if (mcopy == NULL)
                   1540:                return;
1.13      mycroft  1541:        destifp = NULL;
                   1542:
1.1       cgd      1543:        switch (error) {
                   1544:
                   1545:        case 0:                         /* forwarded, but need redirect */
                   1546:                /* type, code set above */
                   1547:                break;
                   1548:
                   1549:        case ENETUNREACH:               /* shouldn't happen, checked above */
                   1550:        case EHOSTUNREACH:
                   1551:        case ENETDOWN:
                   1552:        case EHOSTDOWN:
                   1553:        default:
                   1554:                type = ICMP_UNREACH;
                   1555:                code = ICMP_UNREACH_HOST;
                   1556:                break;
                   1557:
                   1558:        case EMSGSIZE:
                   1559:                type = ICMP_UNREACH;
                   1560:                code = ICMP_UNREACH_NEEDFRAG;
1.89      itojun   1561: #ifndef IPSEC
1.13      mycroft  1562:                if (ipforward_rt.ro_rt)
                   1563:                        destifp = ipforward_rt.ro_rt->rt_ifp;
1.89      itojun   1564: #else
                   1565:                /*
                   1566:                 * If the packet is routed over IPsec tunnel, tell the
                   1567:                 * originator the tunnel MTU.
                   1568:                 *      tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
                   1569:                 * XXX quickhack!!!
                   1570:                 */
                   1571:                if (ipforward_rt.ro_rt) {
                   1572:                        struct secpolicy *sp;
                   1573:                        int ipsecerror;
1.95      itojun   1574:                        size_t ipsechdr;
1.89      itojun   1575:                        struct route *ro;
                   1576:
                   1577:                        sp = ipsec4_getpolicybyaddr(mcopy,
1.95      itojun   1578:                                                    IPSEC_DIR_OUTBOUND,
                   1579:                                                    IP_FORWARDING,
                   1580:                                                    &ipsecerror);
1.89      itojun   1581:
                   1582:                        if (sp == NULL)
                   1583:                                destifp = ipforward_rt.ro_rt->rt_ifp;
                   1584:                        else {
                   1585:                                /* count IPsec header size */
1.95      itojun   1586:                                ipsechdr = ipsec4_hdrsiz(mcopy,
                   1587:                                                         IPSEC_DIR_OUTBOUND,
                   1588:                                                         NULL);
1.89      itojun   1589:
                   1590:                                /*
                   1591:                                 * find the correct route for outer IPv4
                   1592:                                 * header, compute tunnel MTU.
                   1593:                                 *
                   1594:                                 * XXX BUG ALERT
                   1595:                                 * The "dummyifp" code relies upon the fact
                   1596:                                 * that icmp_error() touches only ifp->if_mtu.
                   1597:                                 */
                   1598:                                /*XXX*/
                   1599:                                destifp = NULL;
                   1600:                                if (sp->req != NULL
1.95      itojun   1601:                                 && sp->req->sav != NULL
                   1602:                                 && sp->req->sav->sah != NULL) {
                   1603:                                        ro = &sp->req->sav->sah->sa_route;
1.89      itojun   1604:                                        if (ro->ro_rt && ro->ro_rt->rt_ifp) {
                   1605:                                                dummyifp.if_mtu =
                   1606:                                                    ro->ro_rt->rt_ifp->if_mtu;
                   1607:                                                dummyifp.if_mtu -= ipsechdr;
                   1608:                                                destifp = &dummyifp;
                   1609:                                        }
                   1610:                                }
                   1611:
                   1612:                                key_freesp(sp);
                   1613:                        }
                   1614:                }
                   1615: #endif /*IPSEC*/
1.1       cgd      1616:                ipstat.ips_cantfrag++;
                   1617:                break;
                   1618:
                   1619:        case ENOBUFS:
                   1620:                type = ICMP_SOURCEQUENCH;
                   1621:                code = 0;
                   1622:                break;
                   1623:        }
1.13      mycroft  1624:        icmp_error(mcopy, type, code, dest, destifp);
1.44      thorpej  1625: }
                   1626:
                   1627: void
                   1628: ip_savecontrol(inp, mp, ip, m)
1.109     augustss 1629:        struct inpcb *inp;
                   1630:        struct mbuf **mp;
                   1631:        struct ip *ip;
                   1632:        struct mbuf *m;
1.44      thorpej  1633: {
                   1634:
                   1635:        if (inp->inp_socket->so_options & SO_TIMESTAMP) {
                   1636:                struct timeval tv;
                   1637:
                   1638:                microtime(&tv);
                   1639:                *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
                   1640:                    SCM_TIMESTAMP, SOL_SOCKET);
                   1641:                if (*mp)
                   1642:                        mp = &(*mp)->m_next;
                   1643:        }
                   1644:        if (inp->inp_flags & INP_RECVDSTADDR) {
                   1645:                *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
                   1646:                    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
                   1647:                if (*mp)
                   1648:                        mp = &(*mp)->m_next;
                   1649:        }
                   1650: #ifdef notyet
                   1651:        /*
                   1652:         * XXX
                   1653:         * Moving these out of udp_input() made them even more broken
                   1654:         * than they already were.
                   1655:         *      - fenner@parc.xerox.com
                   1656:         */
                   1657:        /* options were tossed already */
                   1658:        if (inp->inp_flags & INP_RECVOPTS) {
                   1659:                *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
                   1660:                    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
                   1661:                if (*mp)
                   1662:                        mp = &(*mp)->m_next;
                   1663:        }
                   1664:        /* ip_srcroute doesn't do what we want here, need to fix */
                   1665:        if (inp->inp_flags & INP_RECVRETOPTS) {
                   1666:                *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
                   1667:                    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
                   1668:                if (*mp)
                   1669:                        mp = &(*mp)->m_next;
                   1670:        }
                   1671: #endif
                   1672:        if (inp->inp_flags & INP_RECVIF) {
                   1673:                struct sockaddr_dl sdl;
                   1674:
                   1675:                sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
                   1676:                sdl.sdl_family = AF_LINK;
                   1677:                sdl.sdl_index = m->m_pkthdr.rcvif ?
                   1678:                    m->m_pkthdr.rcvif->if_index : 0;
                   1679:                sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
                   1680:                *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
                   1681:                    IP_RECVIF, IPPROTO_IP);
                   1682:                if (*mp)
                   1683:                        mp = &(*mp)->m_next;
                   1684:        }
1.13      mycroft  1685: }
                   1686:
                   1687: int
                   1688: ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
                   1689:        int *name;
                   1690:        u_int namelen;
                   1691:        void *oldp;
                   1692:        size_t *oldlenp;
                   1693:        void *newp;
                   1694:        size_t newlen;
                   1695: {
1.88      sommerfe 1696:        extern int subnetsarelocal, hostzeroisbroadcast;
1.52      thorpej  1697:
1.54      lukem    1698:        int error, old;
                   1699:
1.13      mycroft  1700:        /* All sysctl names at this level are terminal. */
                   1701:        if (namelen != 1)
                   1702:                return (ENOTDIR);
                   1703:
                   1704:        switch (name[0]) {
                   1705:        case IPCTL_FORWARDING:
                   1706:                return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
                   1707:        case IPCTL_SENDREDIRECTS:
                   1708:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1709:                        &ipsendredirects));
                   1710:        case IPCTL_DEFTTL:
                   1711:                return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
                   1712: #ifdef notyet
                   1713:        case IPCTL_DEFMTU:
                   1714:                return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
                   1715: #endif
1.26      thorpej  1716:        case IPCTL_FORWSRCRT:
1.47      cjs      1717:                /* Don't allow this to change in a secure environment.  */
1.26      thorpej  1718:                if (securelevel > 0)
1.46      cjs      1719:                        return (sysctl_rdint(oldp, oldlenp, newp,
                   1720:                            ip_forwsrcrt));
                   1721:                else
                   1722:                        return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1723:                            &ip_forwsrcrt));
1.27      thorpej  1724:        case IPCTL_DIRECTEDBCAST:
                   1725:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1726:                    &ip_directedbcast));
1.47      cjs      1727:        case IPCTL_ALLOWSRCRT:
                   1728:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1729:                    &ip_allowsrcrt));
1.52      thorpej  1730:        case IPCTL_SUBNETSARELOCAL:
                   1731:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1732:                    &subnetsarelocal));
1.53      kml      1733:        case IPCTL_MTUDISC:
1.60      kml      1734:                error = sysctl_int(oldp, oldlenp, newp, newlen,
                   1735:                    &ip_mtudisc);
                   1736:                if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
                   1737:                        ip_mtudisc_timeout_q =
                   1738:                            rt_timer_queue_create(ip_mtudisc_timeout);
                   1739:                } else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
                   1740:                        rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
                   1741:                        ip_mtudisc_timeout_q = NULL;
                   1742:                }
                   1743:                return error;
1.54      lukem    1744:        case IPCTL_ANONPORTMIN:
                   1745:                old = anonportmin;
                   1746:                error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
1.118     itojun   1747:                if (anonportmin >= anonportmax || anonportmin < 0
                   1748:                    || anonportmin > 65535
1.54      lukem    1749: #ifndef IPNOPRIVPORTS
                   1750:                    || anonportmin < IPPORT_RESERVED
                   1751: #endif
                   1752:                    ) {
                   1753:                        anonportmin = old;
                   1754:                        return (EINVAL);
                   1755:                }
                   1756:                return (error);
                   1757:        case IPCTL_ANONPORTMAX:
                   1758:                old = anonportmax;
                   1759:                error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
1.118     itojun   1760:                if (anonportmin >= anonportmax || anonportmax < 0
                   1761:                    || anonportmax > 65535
1.54      lukem    1762: #ifndef IPNOPRIVPORTS
                   1763:                    || anonportmax < IPPORT_RESERVED
                   1764: #endif
                   1765:                    ) {
                   1766:                        anonportmax = old;
                   1767:                        return (EINVAL);
                   1768:                }
1.60      kml      1769:                return (error);
                   1770:        case IPCTL_MTUDISCTIMEOUT:
                   1771:                error = sysctl_int(oldp, oldlenp, newp, newlen,
                   1772:                   &ip_mtudisc_timeout);
                   1773:                if (ip_mtudisc_timeout_q != NULL)
                   1774:                        rt_timer_queue_change(ip_mtudisc_timeout_q,
                   1775:                                              ip_mtudisc_timeout);
1.54      lukem    1776:                return (error);
1.65      matt     1777: #ifdef GATEWAY
                   1778:        case IPCTL_MAXFLOWS:
1.67      thorpej  1779:            {
                   1780:                int s;
                   1781:
1.65      matt     1782:                error = sysctl_int(oldp, oldlenp, newp, newlen,
                   1783:                   &ip_maxflows);
1.67      thorpej  1784:                s = splsoftnet();
1.65      matt     1785:                ipflow_reap(0);
1.67      thorpej  1786:                splx(s);
1.65      matt     1787:                return (error);
1.67      thorpej  1788:            }
1.89      itojun   1789: #endif
1.90      itojun   1790:        case IPCTL_HOSTZEROBROADCAST:
                   1791:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1792:                    &hostzeroisbroadcast));
1.89      itojun   1793: #if NGIF > 0
                   1794:        case IPCTL_GIF_TTL:
                   1795:                return(sysctl_int(oldp, oldlenp, newp, newlen,
1.90      itojun   1796:                                  &ip_gif_ttl));
1.117     tron     1797: #endif
                   1798:
                   1799: #ifndef IPNOPRIVPORTS
                   1800:        case IPCTL_LOWPORTMIN:
                   1801:                old = lowportmin;
                   1802:                error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmin);
                   1803:                if (lowportmin >= lowportmax
                   1804:                    || lowportmin > IPPORT_RESERVEDMAX
                   1805:                    || lowportmin < IPPORT_RESERVEDMIN
                   1806:                    ) {
                   1807:                        lowportmin = old;
                   1808:                        return (EINVAL);
                   1809:                }
                   1810:                return (error);
                   1811:        case IPCTL_LOWPORTMAX:
                   1812:                old = lowportmax;
                   1813:                error = sysctl_int(oldp, oldlenp, newp, newlen, &lowportmax);
                   1814:                if (lowportmin >= lowportmax
                   1815:                    || lowportmax > IPPORT_RESERVEDMAX
                   1816:                    || lowportmax < IPPORT_RESERVEDMIN
                   1817:                    ) {
                   1818:                        lowportmax = old;
                   1819:                        return (EINVAL);
                   1820:                }
                   1821:                return (error);
1.65      matt     1822: #endif
1.131     itojun   1823:
                   1824:        case IPCTL_MAXFRAGPACKETS:
                   1825:                return (sysctl_int(oldp, oldlenp, newp, newlen,
                   1826:                    &ip_maxfragpackets));
1.88      sommerfe 1827:
1.13      mycroft  1828:        default:
                   1829:                return (EOPNOTSUPP);
                   1830:        }
                   1831:        /* NOTREACHED */
1.1       cgd      1832: }

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