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Annotation of src/sys/netinet/ip_input.c, Revision 1.193

1.193   ! scw         1: /*     $NetBSD: ip_input.c,v 1.192 2003/12/08 02:23:27 jonathan Exp $  */
1.89      itojun      2:
                      3: /*
                      4:  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
                      5:  * All rights reserved.
1.152     itojun      6:  *
1.89      itojun      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.
1.152     itojun     18:  *
1.89      itojun     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.
1.172     agc        81:  * 3. Neither the name of the University nor the names of its contributors
1.1       cgd        82:  *    may be used to endorse or promote products derived from this software
                     83:  *    without specific prior written permission.
                     84:  *
                     85:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     86:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     87:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     88:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     89:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     90:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     91:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     92:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     93:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     94:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     95:  * SUCH DAMAGE.
                     96:  *
1.14      cgd        97:  *     @(#)ip_input.c  8.2 (Berkeley) 1/4/94
1.1       cgd        98:  */
1.141     lukem      99:
                    100: #include <sys/cdefs.h>
1.193   ! scw       101: __KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.192 2003/12/08 02:23:27 jonathan Exp $");
1.55      scottr    102:
1.184     jonathan  103: #include "opt_inet.h"
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"
1.167     martin    108: #include "opt_mbuftrace.h"
1.135     thorpej   109: #include "opt_inet_csum.h"
1.1       cgd       110:
1.5       mycroft   111: #include <sys/param.h>
                    112: #include <sys/systm.h>
                    113: #include <sys/malloc.h>
                    114: #include <sys/mbuf.h>
                    115: #include <sys/domain.h>
                    116: #include <sys/protosw.h>
                    117: #include <sys/socket.h>
1.44      thorpej   118: #include <sys/socketvar.h>
1.5       mycroft   119: #include <sys/errno.h>
                    120: #include <sys/time.h>
                    121: #include <sys/kernel.h>
1.72      thorpej   122: #include <sys/pool.h>
1.28      christos  123: #include <sys/sysctl.h>
1.1       cgd       124:
1.5       mycroft   125: #include <net/if.h>
1.44      thorpej   126: #include <net/if_dl.h>
1.5       mycroft   127: #include <net/route.h>
1.45      mrg       128: #include <net/pfil.h>
1.1       cgd       129:
1.5       mycroft   130: #include <netinet/in.h>
                    131: #include <netinet/in_systm.h>
                    132: #include <netinet/ip.h>
                    133: #include <netinet/in_pcb.h>
                    134: #include <netinet/in_var.h>
                    135: #include <netinet/ip_var.h>
                    136: #include <netinet/ip_icmp.h>
1.89      itojun    137: /* just for gif_ttl */
                    138: #include <netinet/in_gif.h>
                    139: #include "gif.h"
1.144     martin    140: #include <net/if_gre.h>
                    141: #include "gre.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
1.173     jonathan  151: #ifdef FAST_IPSEC
                    152: #include <netipsec/ipsec.h>
                    153: #include <netipsec/key.h>
                    154: #endif /* FAST_IPSEC*/
1.44      thorpej   155:
1.1       cgd       156: #ifndef        IPFORWARDING
                    157: #ifdef GATEWAY
                    158: #define        IPFORWARDING    1       /* forward IP packets not for us */
                    159: #else /* GATEWAY */
                    160: #define        IPFORWARDING    0       /* don't forward IP packets not for us */
                    161: #endif /* GATEWAY */
                    162: #endif /* IPFORWARDING */
                    163: #ifndef        IPSENDREDIRECTS
                    164: #define        IPSENDREDIRECTS 1
                    165: #endif
1.26      thorpej   166: #ifndef IPFORWSRCRT
1.47      cjs       167: #define        IPFORWSRCRT     1       /* forward source-routed packets */
                    168: #endif
                    169: #ifndef IPALLOWSRCRT
1.48      mrg       170: #define        IPALLOWSRCRT    1       /* allow source-routed packets */
1.26      thorpej   171: #endif
1.53      kml       172: #ifndef IPMTUDISC
1.153     itojun    173: #define IPMTUDISC      1
1.53      kml       174: #endif
1.60      kml       175: #ifndef IPMTUDISCTIMEOUT
1.61      kml       176: #define IPMTUDISCTIMEOUT (10 * 60)     /* as per RFC 1191 */
1.60      kml       177: #endif
1.53      kml       178:
1.27      thorpej   179: /*
                    180:  * Note: DIRECTED_BROADCAST is handled this way so that previous
                    181:  * configuration using this option will Just Work.
                    182:  */
                    183: #ifndef IPDIRECTEDBCAST
                    184: #ifdef DIRECTED_BROADCAST
                    185: #define IPDIRECTEDBCAST        1
                    186: #else
                    187: #define        IPDIRECTEDBCAST 0
                    188: #endif /* DIRECTED_BROADCAST */
                    189: #endif /* IPDIRECTEDBCAST */
1.1       cgd       190: int    ipforwarding = IPFORWARDING;
                    191: int    ipsendredirects = IPSENDREDIRECTS;
1.13      mycroft   192: int    ip_defttl = IPDEFTTL;
1.26      thorpej   193: int    ip_forwsrcrt = IPFORWSRCRT;
1.27      thorpej   194: int    ip_directedbcast = IPDIRECTEDBCAST;
1.47      cjs       195: int    ip_allowsrcrt = IPALLOWSRCRT;
1.53      kml       196: int    ip_mtudisc = IPMTUDISC;
1.156     itojun    197: int    ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1       cgd       198: #ifdef DIAGNOSTIC
                    199: int    ipprintfs = 0;
                    200: #endif
1.184     jonathan  201:
                    202: int    ip_do_randomid = 0;
                    203:
1.165     christos  204: /*
                    205:  * XXX - Setting ip_checkinterface mostly implements the receive side of
                    206:  * the Strong ES model described in RFC 1122, but since the routing table
                    207:  * and transmit implementation do not implement the Strong ES model,
                    208:  * setting this to 1 results in an odd hybrid.
                    209:  *
                    210:  * XXX - ip_checkinterface currently must be disabled if you use ipnat
                    211:  * to translate the destination address to another local interface.
                    212:  *
                    213:  * XXX - ip_checkinterface must be disabled if you add IP aliases
                    214:  * to the loopback interface instead of the interface where the
                    215:  * packets for those addresses are received.
                    216:  */
                    217: int    ip_checkinterface = 0;
                    218:
1.1       cgd       219:
1.60      kml       220: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
                    221:
1.1       cgd       222: extern struct domain inetdomain;
                    223: int    ipqmaxlen = IFQ_MAXLEN;
1.150     matt      224: u_long in_ifaddrhash;                          /* size of hash table - 1 */
                    225: int    in_ifaddrentries;                       /* total number of addrs */
1.181     jonathan  226: struct in_ifaddrhead in_ifaddrhead;
1.57      tls       227: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.166     matt      228: u_long in_multihash;                           /* size of hash table - 1 */
                    229: int    in_multientries;                        /* total number of addrs */
                    230: struct in_multihashhead *in_multihashtbl;
1.13      mycroft   231: struct ifqueue ipintrq;
1.63      matt      232: struct ipstat  ipstat;
1.183     jonathan  233: uint16_t ip_id;
1.75      thorpej   234:
1.121     thorpej   235: #ifdef PFIL_HOOKS
                    236: struct pfil_head inet_pfil_hook;
                    237: #endif
                    238:
1.190     jonathan  239: /* IP datagram reassembly queues (hashed) */
                    240: #define IPREASS_NHASH_LOG2      6
                    241: #define IPREASS_NHASH           (1 << IPREASS_NHASH_LOG2)
                    242: #define IPREASS_HMASK           (IPREASS_NHASH - 1)
                    243: #define IPREASS_HASH(x,y) \
                    244:        (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
                    245: struct ipqhead ipq[IPREASS_NHASH];
1.75      thorpej   246: int    ipq_locked;
1.131     itojun    247: int    ip_nfragpackets = 0;
1.133     itojun    248: int    ip_maxfragpackets = 200;
1.192     jonathan  249: int    ip_nfrags = 0;         /* total fragments in reass queues */
1.75      thorpej   250:
                    251: static __inline int ipq_lock_try __P((void));
                    252: static __inline void ipq_unlock __P((void));
                    253:
                    254: static __inline int
                    255: ipq_lock_try()
                    256: {
                    257:        int s;
                    258:
1.132     thorpej   259:        /*
1.149     wiz       260:         * Use splvm() -- we're blocking things that would cause
1.132     thorpej   261:         * mbuf allocation.
                    262:         */
                    263:        s = splvm();
1.75      thorpej   264:        if (ipq_locked) {
                    265:                splx(s);
                    266:                return (0);
                    267:        }
                    268:        ipq_locked = 1;
                    269:        splx(s);
                    270:        return (1);
                    271: }
                    272:
                    273: static __inline void
                    274: ipq_unlock()
                    275: {
                    276:        int s;
                    277:
1.132     thorpej   278:        s = splvm();
1.75      thorpej   279:        ipq_locked = 0;
                    280:        splx(s);
                    281: }
                    282:
                    283: #ifdef DIAGNOSTIC
                    284: #define        IPQ_LOCK()                                                      \
                    285: do {                                                                   \
                    286:        if (ipq_lock_try() == 0) {                                      \
                    287:                printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
                    288:                panic("ipq_lock");                                      \
                    289:        }                                                               \
1.159     perry     290: } while (/*CONSTCOND*/ 0)
1.75      thorpej   291: #define        IPQ_LOCK_CHECK()                                                \
                    292: do {                                                                   \
                    293:        if (ipq_locked == 0) {                                          \
                    294:                printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
                    295:                panic("ipq lock check");                                \
                    296:        }                                                               \
1.159     perry     297: } while (/*CONSTCOND*/ 0)
1.75      thorpej   298: #else
                    299: #define        IPQ_LOCK()              (void) ipq_lock_try()
                    300: #define        IPQ_LOCK_CHECK()        /* nothing */
                    301: #endif
                    302:
                    303: #define        IPQ_UNLOCK()            ipq_unlock()
1.1       cgd       304:
1.166     matt      305: struct pool inmulti_pool;
1.72      thorpej   306: struct pool ipqent_pool;
                    307:
1.135     thorpej   308: #ifdef INET_CSUM_COUNTERS
                    309: #include <sys/device.h>
                    310:
                    311: struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
                    312:     NULL, "inet", "hwcsum bad");
                    313: struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
                    314:     NULL, "inet", "hwcsum ok");
                    315: struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
                    316:     NULL, "inet", "swcsum");
                    317:
                    318: #define        INET_CSUM_COUNTER_INCR(ev)      (ev)->ev_count++
                    319:
                    320: #else
                    321:
                    322: #define        INET_CSUM_COUNTER_INCR(ev)      /* nothing */
                    323:
                    324: #endif /* INET_CSUM_COUNTERS */
                    325:
1.1       cgd       326: /*
                    327:  * We need to save the IP options in case a protocol wants to respond
                    328:  * to an incoming packet over the same route if the packet got here
                    329:  * using IP source routing.  This allows connection establishment and
                    330:  * maintenance when the remote end is on a network that is not known
                    331:  * to us.
                    332:  */
                    333: int    ip_nhops = 0;
                    334: static struct ip_srcrt {
                    335:        struct  in_addr dst;                    /* final destination */
                    336:        char    nop;                            /* one NOP to align */
                    337:        char    srcopt[IPOPT_OFFSET + 1];       /* OPTVAL, OLEN and OFFSET */
                    338:        struct  in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
                    339: } ip_srcrt;
                    340:
1.13      mycroft   341: static void save_rte __P((u_char *, struct in_addr));
1.35      mycroft   342:
1.164     matt      343: #ifdef MBUFTRACE
                    344: struct mowner ip_rx_mowner = { "internet", "rx" };
                    345: struct mowner ip_tx_mowner = { "internet", "tx" };
                    346: #endif
                    347:
1.1       cgd       348: /*
                    349:  * IP initialization: fill in IP protocol switch table.
                    350:  * All protocols not implemented in kernel go to raw IP protocol handler.
                    351:  */
1.8       mycroft   352: void
1.1       cgd       353: ip_init()
                    354: {
1.109     augustss  355:        struct protosw *pr;
                    356:        int i;
1.1       cgd       357:
1.166     matt      358:        pool_init(&inmulti_pool, sizeof(struct in_multi), 0, 0, 0, "inmltpl",
                    359:            NULL);
1.72      thorpej   360:        pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
1.146     thorpej   361:            NULL);
1.72      thorpej   362:
1.1       cgd       363:        pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
                    364:        if (pr == 0)
                    365:                panic("ip_init");
                    366:        for (i = 0; i < IPPROTO_MAX; i++)
                    367:                ip_protox[i] = pr - inetsw;
                    368:        for (pr = inetdomain.dom_protosw;
                    369:            pr < inetdomain.dom_protoswNPROTOSW; pr++)
                    370:                if (pr->pr_domain->dom_family == PF_INET &&
                    371:                    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
                    372:                        ip_protox[pr->pr_protocol] = pr - inetsw;
1.192     jonathan  373:
1.190     jonathan  374:        for (i = 0; i < IPREASS_NHASH; i++)
                    375:                LIST_INIT(&ipq[i]);
                    376:
1.183     jonathan  377:        ip_id = time.tv_sec & 0xfffff;
1.1       cgd       378:        ipintrq.ifq_maxlen = ipqmaxlen;
1.181     jonathan  379:        TAILQ_INIT(&in_ifaddrhead);
1.120     ad        380:        in_ifaddrhashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IFADDR,
                    381:            M_WAITOK, &in_ifaddrhash);
1.166     matt      382:        in_multihashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IPMADDR,
                    383:            M_WAITOK, &in_multihash);
1.160     itojun    384:        ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
1.73      thorpej   385: #ifdef GATEWAY
                    386:        ipflow_init();
                    387: #endif
1.121     thorpej   388:
                    389: #ifdef PFIL_HOOKS
                    390:        /* Register our Packet Filter hook. */
1.126     thorpej   391:        inet_pfil_hook.ph_type = PFIL_TYPE_AF;
                    392:        inet_pfil_hook.ph_af   = AF_INET;
1.121     thorpej   393:        i = pfil_head_register(&inet_pfil_hook);
                    394:        if (i != 0)
                    395:                printf("ip_init: WARNING: unable to register pfil hook, "
                    396:                    "error %d\n", i);
                    397: #endif /* PFIL_HOOKS */
1.135     thorpej   398:
                    399: #ifdef INET_CSUM_COUNTERS
                    400:        evcnt_attach_static(&ip_hwcsum_bad);
                    401:        evcnt_attach_static(&ip_hwcsum_ok);
                    402:        evcnt_attach_static(&ip_swcsum);
                    403: #endif /* INET_CSUM_COUNTERS */
1.164     matt      404:
                    405: #ifdef MBUFTRACE
                    406:        MOWNER_ATTACH(&ip_tx_mowner);
                    407:        MOWNER_ATTACH(&ip_rx_mowner);
                    408: #endif /* MBUFTRACE */
1.1       cgd       409: }
                    410:
                    411: struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
                    412: struct route ipforward_rt;
                    413:
                    414: /*
1.89      itojun    415:  * IP software interrupt routine
                    416:  */
                    417: void
                    418: ipintr()
                    419: {
                    420:        int s;
                    421:        struct mbuf *m;
                    422:
                    423:        while (1) {
1.132     thorpej   424:                s = splnet();
1.89      itojun    425:                IF_DEQUEUE(&ipintrq, m);
                    426:                splx(s);
                    427:                if (m == 0)
                    428:                        return;
1.164     matt      429:                MCLAIM(m, &ip_rx_mowner);
1.89      itojun    430:                ip_input(m);
                    431:        }
                    432: }
                    433:
                    434: /*
1.1       cgd       435:  * Ip input routine.  Checksum and byte swap header.  If fragmented
                    436:  * try to reassemble.  Process options.  Pass to next level.
                    437:  */
1.8       mycroft   438: void
1.89      itojun    439: ip_input(struct mbuf *m)
1.1       cgd       440: {
1.109     augustss  441:        struct ip *ip = NULL;
                    442:        struct ipq *fp;
                    443:        struct in_ifaddr *ia;
                    444:        struct ifaddr *ifa;
1.25      cgd       445:        struct ipqent *ipqe;
1.89      itojun    446:        int hlen = 0, mff, len;
1.100     itojun    447:        int downmatch;
1.165     christos  448:        int checkif;
1.169     itojun    449:        int srcrt = 0;
1.190     jonathan  450:        u_int hash;
1.173     jonathan  451: #ifdef FAST_IPSEC
                    452:        struct m_tag *mtag;
                    453:        struct tdb_ident *tdbi;
                    454:        struct secpolicy *sp;
                    455:        int s, error;
                    456: #endif /* FAST_IPSEC */
1.1       cgd       457:
1.164     matt      458:        MCLAIM(m, &ip_rx_mowner);
1.1       cgd       459: #ifdef DIAGNOSTIC
                    460:        if ((m->m_flags & M_PKTHDR) == 0)
                    461:                panic("ipintr no HDR");
1.89      itojun    462: #endif
1.164     matt      463:
1.1       cgd       464:        /*
                    465:         * If no IP addresses have been set yet but the interfaces
                    466:         * are receiving, can't do anything with incoming packets yet.
                    467:         */
1.181     jonathan  468:        if (TAILQ_FIRST(&in_ifaddrhead) == 0)
1.1       cgd       469:                goto bad;
                    470:        ipstat.ips_total++;
1.154     thorpej   471:        /*
                    472:         * If the IP header is not aligned, slurp it up into a new
                    473:         * mbuf with space for link headers, in the event we forward
                    474:         * it.  Otherwise, if it is aligned, make sure the entire
                    475:         * base IP header is in the first mbuf of the chain.
                    476:         */
                    477:        if (IP_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) {
                    478:                if ((m = m_copyup(m, sizeof(struct ip),
                    479:                                  (max_linkhdr + 3) & ~3)) == NULL) {
                    480:                        /* XXXJRT new stat, please */
                    481:                        ipstat.ips_toosmall++;
                    482:                        return;
                    483:                }
                    484:        } else if (__predict_false(m->m_len < sizeof (struct ip))) {
                    485:                if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
                    486:                        ipstat.ips_toosmall++;
                    487:                        return;
                    488:                }
1.1       cgd       489:        }
                    490:        ip = mtod(m, struct ip *);
1.13      mycroft   491:        if (ip->ip_v != IPVERSION) {
                    492:                ipstat.ips_badvers++;
                    493:                goto bad;
                    494:        }
1.1       cgd       495:        hlen = ip->ip_hl << 2;
                    496:        if (hlen < sizeof(struct ip)) { /* minimum header length */
                    497:                ipstat.ips_badhlen++;
                    498:                goto bad;
                    499:        }
                    500:        if (hlen > m->m_len) {
                    501:                if ((m = m_pullup(m, hlen)) == 0) {
                    502:                        ipstat.ips_badhlen++;
1.89      itojun    503:                        return;
1.1       cgd       504:                }
                    505:                ip = mtod(m, struct ip *);
                    506:        }
1.98      thorpej   507:
1.85      hwr       508:        /*
1.99      thorpej   509:         * RFC1122: packets with a multicast source address are
1.98      thorpej   510:         * not allowed.
1.85      hwr       511:         */
                    512:        if (IN_MULTICAST(ip->ip_src.s_addr)) {
1.130     itojun    513:                ipstat.ips_badaddr++;
1.85      hwr       514:                goto bad;
1.129     itojun    515:        }
                    516:
                    517:        /* 127/8 must not appear on wire - RFC1122 */
                    518:        if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
                    519:            (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
1.130     itojun    520:                if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
                    521:                        ipstat.ips_badaddr++;
1.129     itojun    522:                        goto bad;
1.130     itojun    523:                }
1.85      hwr       524:        }
                    525:
1.135     thorpej   526:        switch (m->m_pkthdr.csum_flags &
1.137     thorpej   527:                ((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
1.135     thorpej   528:                 M_CSUM_IPv4_BAD)) {
                    529:        case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
                    530:                INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
                    531:                goto badcsum;
                    532:
                    533:        case M_CSUM_IPv4:
                    534:                /* Checksum was okay. */
                    535:                INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
                    536:                break;
                    537:
                    538:        default:
                    539:                /* Must compute it ourselves. */
                    540:                INET_CSUM_COUNTER_INCR(&ip_swcsum);
                    541:                if (in_cksum(m, hlen) != 0)
                    542:                        goto bad;
                    543:                break;
1.1       cgd       544:        }
                    545:
1.121     thorpej   546:        /* Retrieve the packet length. */
                    547:        len = ntohs(ip->ip_len);
1.81      proff     548:
                    549:        /*
                    550:         * Check for additional length bogosity
                    551:         */
1.84      proff     552:        if (len < hlen) {
1.81      proff     553:                ipstat.ips_badlen++;
                    554:                goto bad;
                    555:        }
1.1       cgd       556:
                    557:        /*
                    558:         * Check that the amount of data in the buffers
                    559:         * is as at least much as the IP header would have us expect.
                    560:         * Trim mbufs if longer than we expect.
                    561:         * Drop packet if shorter than we expect.
                    562:         */
1.35      mycroft   563:        if (m->m_pkthdr.len < len) {
1.1       cgd       564:                ipstat.ips_tooshort++;
                    565:                goto bad;
                    566:        }
1.35      mycroft   567:        if (m->m_pkthdr.len > len) {
1.1       cgd       568:                if (m->m_len == m->m_pkthdr.len) {
1.35      mycroft   569:                        m->m_len = len;
                    570:                        m->m_pkthdr.len = len;
1.1       cgd       571:                } else
1.35      mycroft   572:                        m_adj(m, len - m->m_pkthdr.len);
1.1       cgd       573:        }
                    574:
1.193   ! scw       575: #if defined(IPSEC)
1.149     wiz       576:        /* ipflow (IP fast forwarding) is not compatible with IPsec. */
1.94      itojun    577:        m->m_flags &= ~M_CANFASTFWD;
                    578: #else
1.64      thorpej   579:        /*
                    580:         * Assume that we can create a fast-forward IP flow entry
                    581:         * based on this packet.
                    582:         */
                    583:        m->m_flags |= M_CANFASTFWD;
1.94      itojun    584: #endif
1.64      thorpej   585:
1.36      mrg       586: #ifdef PFIL_HOOKS
1.33      mrg       587:        /*
1.64      thorpej   588:         * Run through list of hooks for input packets.  If there are any
                    589:         * filters which require that additional packets in the flow are
                    590:         * not fast-forwarded, they must clear the M_CANFASTFWD flag.
                    591:         * Note that filters must _never_ set this flag, as another filter
                    592:         * in the list may have previously cleared it.
1.33      mrg       593:         */
1.127     itojun    594:        /*
                    595:         * let ipfilter look at packet on the wire,
                    596:         * not the decapsulated packet.
                    597:         */
                    598: #ifdef IPSEC
1.136     itojun    599:        if (!ipsec_getnhist(m))
1.186     scw       600: #elif defined(FAST_IPSEC)
                    601:        if (!ipsec_indone(m))
1.127     itojun    602: #else
                    603:        if (1)
                    604: #endif
                    605:        {
1.169     itojun    606:                struct in_addr odst;
                    607:
                    608:                odst = ip->ip_dst;
1.127     itojun    609:                if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
1.168     itojun    610:                    PFIL_IN) != 0)
                    611:                        return;
1.127     itojun    612:                if (m == NULL)
                    613:                        return;
                    614:                ip = mtod(m, struct ip *);
1.142     darrenr   615:                hlen = ip->ip_hl << 2;
1.169     itojun    616:                srcrt = (odst.s_addr != ip->ip_dst.s_addr);
1.127     itojun    617:        }
1.36      mrg       618: #endif /* PFIL_HOOKS */
1.123     thorpej   619:
                    620: #ifdef ALTQ
                    621:        /* XXX Temporary until ALTQ is changed to use a pfil hook */
                    622:        if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
                    623:                /* packet dropped by traffic conditioner */
                    624:                return;
                    625:        }
                    626: #endif
1.121     thorpej   627:
                    628:        /*
1.1       cgd       629:         * Process options and, if not destined for us,
                    630:         * ship it on.  ip_dooptions returns 1 when an
                    631:         * error was detected (causing an icmp message
                    632:         * to be sent and the original packet to be freed).
                    633:         */
                    634:        ip_nhops = 0;           /* for source routed packets */
                    635:        if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.89      itojun    636:                return;
1.1       cgd       637:
                    638:        /*
1.165     christos  639:         * Enable a consistency check between the destination address
                    640:         * and the arrival interface for a unicast packet (the RFC 1122
                    641:         * strong ES model) if IP forwarding is disabled and the packet
                    642:         * is not locally generated.
                    643:         *
                    644:         * XXX - Checking also should be disabled if the destination
                    645:         * address is ipnat'ed to a different interface.
                    646:         *
                    647:         * XXX - Checking is incompatible with IP aliases added
                    648:         * to the loopback interface instead of the interface where
                    649:         * the packets are received.
                    650:         *
                    651:         * XXX - We need to add a per ifaddr flag for this so that
                    652:         * we get finer grain control.
                    653:         */
                    654:        checkif = ip_checkinterface && (ipforwarding == 0) &&
                    655:            (m->m_pkthdr.rcvif != NULL) &&
                    656:            ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0);
                    657:
                    658:        /*
1.1       cgd       659:         * Check our list of addresses, to see if the packet is for us.
1.100     itojun    660:         *
                    661:         * Traditional 4.4BSD did not consult IFF_UP at all.
                    662:         * The behavior here is to treat addresses on !IFF_UP interface
                    663:         * as not mine.
1.1       cgd       664:         */
1.100     itojun    665:        downmatch = 0;
1.140     matt      666:        LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
1.97      itojun    667:                if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
1.165     christos  668:                        if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif)
                    669:                                continue;
1.97      itojun    670:                        if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
                    671:                                break;
1.100     itojun    672:                        else
                    673:                                downmatch++;
1.97      itojun    674:                }
                    675:        }
1.86      thorpej   676:        if (ia != NULL)
                    677:                goto ours;
1.57      tls       678:        if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
1.140     matt      679:                TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) {
                    680:                        if (ifa->ifa_addr->sa_family != AF_INET)
                    681:                                continue;
1.57      tls       682:                        ia = ifatoia(ifa);
1.35      mycroft   683:                        if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
                    684:                            in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20      mycroft   685:                            /*
                    686:                             * Look for all-0's host part (old broadcast addr),
                    687:                             * either for subnet or net.
                    688:                             */
                    689:                            ip->ip_dst.s_addr == ia->ia_subnet ||
1.18      mycroft   690:                            ip->ip_dst.s_addr == ia->ia_net)
1.1       cgd       691:                                goto ours;
1.57      tls       692:                        /*
                    693:                         * An interface with IP address zero accepts
                    694:                         * all packets that arrive on that interface.
                    695:                         */
                    696:                        if (in_nullhost(ia->ia_addr.sin_addr))
                    697:                                goto ours;
1.1       cgd       698:                }
                    699:        }
1.18      mycroft   700:        if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4       hpeyerl   701:                struct in_multi *inm;
                    702: #ifdef MROUTING
                    703:                extern struct socket *ip_mrouter;
1.10      brezak    704:
1.147     matt      705:                if (M_READONLY(m)) {
1.10      brezak    706:                        if ((m = m_pullup(m, hlen)) == 0) {
                    707:                                ipstat.ips_toosmall++;
1.89      itojun    708:                                return;
1.10      brezak    709:                        }
                    710:                        ip = mtod(m, struct ip *);
                    711:                }
1.4       hpeyerl   712:
                    713:                if (ip_mrouter) {
                    714:                        /*
                    715:                         * If we are acting as a multicast router, all
                    716:                         * incoming multicast packets are passed to the
                    717:                         * kernel-level multicast forwarding function.
                    718:                         * The packet is returned (relatively) intact; if
                    719:                         * ip_mforward() returns a non-zero value, the packet
                    720:                         * must be discarded, else it may be accepted below.
                    721:                         *
                    722:                         * (The IP ident field is put in the same byte order
                    723:                         * as expected when ip_mforward() is called from
                    724:                         * ip_output().)
                    725:                         */
1.13      mycroft   726:                        if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
                    727:                                ipstat.ips_cantforward++;
1.4       hpeyerl   728:                                m_freem(m);
1.89      itojun    729:                                return;
1.4       hpeyerl   730:                        }
                    731:
                    732:                        /*
                    733:                         * The process-level routing demon needs to receive
                    734:                         * all multicast IGMP packets, whether or not this
                    735:                         * host belongs to their destination groups.
                    736:                         */
                    737:                        if (ip->ip_p == IPPROTO_IGMP)
                    738:                                goto ours;
1.13      mycroft   739:                        ipstat.ips_forward++;
1.4       hpeyerl   740:                }
                    741: #endif
                    742:                /*
                    743:                 * See if we belong to the destination multicast group on the
                    744:                 * arrival interface.
                    745:                 */
                    746:                IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
                    747:                if (inm == NULL) {
1.13      mycroft   748:                        ipstat.ips_cantforward++;
1.4       hpeyerl   749:                        m_freem(m);
1.89      itojun    750:                        return;
1.4       hpeyerl   751:                }
                    752:                goto ours;
                    753:        }
1.19      mycroft   754:        if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35      mycroft   755:            in_nullhost(ip->ip_dst))
1.1       cgd       756:                goto ours;
                    757:
                    758:        /*
                    759:         * Not for us; forward if possible and desirable.
                    760:         */
                    761:        if (ipforwarding == 0) {
                    762:                ipstat.ips_cantforward++;
                    763:                m_freem(m);
1.100     itojun    764:        } else {
                    765:                /*
                    766:                 * If ip_dst matched any of my address on !IFF_UP interface,
                    767:                 * and there's no IFF_UP interface that matches ip_dst,
                    768:                 * send icmp unreach.  Forwarding it will result in in-kernel
                    769:                 * forwarding loop till TTL goes to 0.
                    770:                 */
                    771:                if (downmatch) {
                    772:                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
                    773:                        ipstat.ips_cantforward++;
                    774:                        return;
                    775:                }
1.145     itojun    776: #ifdef IPSEC
                    777:                if (ipsec4_in_reject(m, NULL)) {
                    778:                        ipsecstat.in_polvio++;
                    779:                        goto bad;
                    780:                }
                    781: #endif
1.173     jonathan  782: #ifdef FAST_IPSEC
                    783:                mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
                    784:                s = splsoftnet();
                    785:                if (mtag != NULL) {
                    786:                        tdbi = (struct tdb_ident *)(mtag + 1);
                    787:                        sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
                    788:                } else {
                    789:                        sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
                    790:                                                   IP_FORWARDING, &error);
                    791:                }
                    792:                if (sp == NULL) {       /* NB: can happen if error */
                    793:                        splx(s);
                    794:                        /*XXX error stat???*/
                    795:                        DPRINTF(("ip_input: no SP for forwarding\n"));  /*XXX*/
                    796:                        goto bad;
                    797:                }
                    798:
                    799:                /*
                    800:                 * Check security policy against packet attributes.
                    801:                 */
                    802:                error = ipsec_in_reject(sp, m);
                    803:                KEY_FREESP(&sp);
                    804:                splx(s);
                    805:                if (error) {
                    806:                        ipstat.ips_cantforward++;
                    807:                        goto bad;
1.193   ! scw       808:                }
        !           809:
        !           810:                /*
        !           811:                 * Peek at the outbound SP for this packet to determine if
        !           812:                 * it's a Fast Forward candidate.
        !           813:                 */
        !           814:                mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
        !           815:                if (mtag != NULL)
        !           816:                        m->m_flags &= ~M_CANFASTFWD;
        !           817:                else {
        !           818:                        s = splsoftnet();
        !           819:                        sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND,
        !           820:                            (IP_FORWARDING |
        !           821:                             (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
        !           822:                            &error, NULL);
        !           823:                        if (sp != NULL) {
        !           824:                                m->m_flags &= ~M_CANFASTFWD;
        !           825:                                KEY_FREESP(&sp);
        !           826:                        }
        !           827:                        splx(s);
1.173     jonathan  828:                }
                    829: #endif /* FAST_IPSEC */
1.145     itojun    830:
1.169     itojun    831:                ip_forward(m, srcrt);
1.100     itojun    832:        }
1.89      itojun    833:        return;
1.1       cgd       834:
                    835: ours:
                    836:        /*
                    837:         * If offset or IP_MF are set, must reassemble.
                    838:         * Otherwise, nothing need be done.
                    839:         * (We could look in the reassembly queue to see
                    840:         * if the packet was previously fragmented,
                    841:         * but it's not worth the time; just let them time out.)
                    842:         */
1.155     itojun    843:        if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
                    844:                if (M_READONLY(m)) {
                    845:                        if ((m = m_pullup(m, hlen)) == NULL) {
                    846:                                ipstat.ips_toosmall++;
                    847:                                goto bad;
                    848:                        }
                    849:                        ip = mtod(m, struct ip *);
                    850:                }
                    851:
1.1       cgd       852:                /*
                    853:                 * Look for queue of fragments
                    854:                 * of this datagram.
                    855:                 */
1.75      thorpej   856:                IPQ_LOCK();
1.190     jonathan  857:                hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
                    858:                /* XXX LIST_FOREACH(fp, &ipq[hash], ipq_q) */
                    859:                for (fp = LIST_FIRST(&ipq[hash]); fp != NULL;
                    860:                     fp = LIST_NEXT(fp, ipq_q)) {
1.1       cgd       861:                        if (ip->ip_id == fp->ipq_id &&
1.35      mycroft   862:                            in_hosteq(ip->ip_src, fp->ipq_src) &&
                    863:                            in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1       cgd       864:                            ip->ip_p == fp->ipq_p)
                    865:                                goto found;
1.190     jonathan  866:
                    867:                }
1.1       cgd       868:                fp = 0;
                    869: found:
                    870:
                    871:                /*
                    872:                 * Adjust ip_len to not reflect header,
1.25      cgd       873:                 * set ipqe_mff if more fragments are expected,
1.1       cgd       874:                 * convert offset of this to bytes.
                    875:                 */
1.155     itojun    876:                ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
                    877:                mff = (ip->ip_off & htons(IP_MF)) != 0;
1.25      cgd       878:                if (mff) {
1.16      cgd       879:                        /*
                    880:                         * Make sure that fragments have a data length
                    881:                         * that's a non-zero multiple of 8 bytes.
                    882:                         */
1.155     itojun    883:                        if (ntohs(ip->ip_len) == 0 ||
                    884:                            (ntohs(ip->ip_len) & 0x7) != 0) {
1.16      cgd       885:                                ipstat.ips_badfrags++;
1.75      thorpej   886:                                IPQ_UNLOCK();
1.16      cgd       887:                                goto bad;
                    888:                        }
                    889:                }
1.155     itojun    890:                ip->ip_off = htons((ntohs(ip->ip_off) & IP_OFFMASK) << 3);
1.1       cgd       891:
                    892:                /*
                    893:                 * If datagram marked as having more fragments
                    894:                 * or if this is not the first fragment,
                    895:                 * attempt reassembly; if it succeeds, proceed.
                    896:                 */
1.155     itojun    897:                if (mff || ip->ip_off != htons(0)) {
1.1       cgd       898:                        ipstat.ips_fragments++;
1.72      thorpej   899:                        ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25      cgd       900:                        if (ipqe == NULL) {
                    901:                                ipstat.ips_rcvmemdrop++;
1.75      thorpej   902:                                IPQ_UNLOCK();
1.25      cgd       903:                                goto bad;
                    904:                        }
                    905:                        ipqe->ipqe_mff = mff;
1.50      thorpej   906:                        ipqe->ipqe_m = m;
1.25      cgd       907:                        ipqe->ipqe_ip = ip;
1.190     jonathan  908:                        m = ip_reass(ipqe, fp, &ipq[hash]);
1.75      thorpej   909:                        if (m == 0) {
                    910:                                IPQ_UNLOCK();
1.89      itojun    911:                                return;
1.75      thorpej   912:                        }
1.13      mycroft   913:                        ipstat.ips_reassembled++;
1.50      thorpej   914:                        ip = mtod(m, struct ip *);
1.74      thorpej   915:                        hlen = ip->ip_hl << 2;
1.155     itojun    916:                        ip->ip_len = htons(ntohs(ip->ip_len) + hlen);
1.1       cgd       917:                } else
                    918:                        if (fp)
                    919:                                ip_freef(fp);
1.75      thorpej   920:                IPQ_UNLOCK();
1.79      mycroft   921:        }
1.128     itojun    922:
1.173     jonathan  923: #if defined(IPSEC)
1.128     itojun    924:        /*
                    925:         * enforce IPsec policy checking if we are seeing last header.
                    926:         * note that we do not visit this with protocols with pcb layer
                    927:         * code - like udp/tcp/raw ip.
                    928:         */
                    929:        if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
                    930:            ipsec4_in_reject(m, NULL)) {
                    931:                ipsecstat.in_polvio++;
                    932:                goto bad;
                    933:        }
                    934: #endif
1.173     jonathan  935: #if FAST_IPSEC
                    936:        /*
                    937:         * enforce IPsec policy checking if we are seeing last header.
                    938:         * note that we do not visit this with protocols with pcb layer
                    939:         * code - like udp/tcp/raw ip.
                    940:         */
                    941:        if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
                    942:                /*
                    943:                 * Check if the packet has already had IPsec processing
                    944:                 * done.  If so, then just pass it along.  This tag gets
                    945:                 * set during AH, ESP, etc. input handling, before the
                    946:                 * packet is returned to the ip input queue for delivery.
                    947:                 */
                    948:                mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
                    949:                s = splsoftnet();
                    950:                if (mtag != NULL) {
                    951:                        tdbi = (struct tdb_ident *)(mtag + 1);
                    952:                        sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
                    953:                } else {
                    954:                        sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
                    955:                                                   IP_FORWARDING, &error);
                    956:                }
                    957:                if (sp != NULL) {
                    958:                        /*
                    959:                         * Check security policy against packet attributes.
                    960:                         */
                    961:                        error = ipsec_in_reject(sp, m);
                    962:                        KEY_FREESP(&sp);
                    963:                } else {
                    964:                        /* XXX error stat??? */
                    965:                        error = EINVAL;
                    966: DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
                    967:                        goto bad;
                    968:                }
                    969:                splx(s);
                    970:                if (error)
                    971:                        goto bad;
                    972:        }
                    973: #endif /* FAST_IPSEC */
1.1       cgd       974:
                    975:        /*
                    976:         * Switch out to protocol's input routine.
                    977:         */
1.82      aidan     978: #if IFA_STATS
1.122     itojun    979:        if (ia && ip)
1.155     itojun    980:                ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
1.82      aidan     981: #endif
1.1       cgd       982:        ipstat.ips_delivered++;
1.89      itojun    983:     {
                    984:        int off = hlen, nh = ip->ip_p;
                    985:
                    986:        (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
                    987:        return;
                    988:     }
1.1       cgd       989: bad:
                    990:        m_freem(m);
1.135     thorpej   991:        return;
                    992:
                    993: badcsum:
                    994:        ipstat.ips_badsum++;
                    995:        m_freem(m);
1.1       cgd       996: }
                    997:
                    998: /*
                    999:  * Take incoming datagram fragment and try to
                   1000:  * reassemble it into whole datagram.  If a chain for
                   1001:  * reassembly of this datagram already exists, then it
                   1002:  * is given as fp; otherwise have to make a chain.
                   1003:  */
1.50      thorpej  1004: struct mbuf *
1.190     jonathan 1005: ip_reass(ipqe, fp, ipqhead)
1.109     augustss 1006:        struct ipqent *ipqe;
                   1007:        struct ipq *fp;
1.190     jonathan 1008:        struct ipqhead *ipqhead;
1.1       cgd      1009: {
1.109     augustss 1010:        struct mbuf *m = ipqe->ipqe_m;
                   1011:        struct ipqent *nq, *p, *q;
1.25      cgd      1012:        struct ip *ip;
1.1       cgd      1013:        struct mbuf *t;
1.25      cgd      1014:        int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1       cgd      1015:        int i, next;
                   1016:
1.75      thorpej  1017:        IPQ_LOCK_CHECK();
                   1018:
1.1       cgd      1019:        /*
                   1020:         * Presence of header sizes in mbufs
                   1021:         * would confuse code below.
                   1022:         */
                   1023:        m->m_data += hlen;
                   1024:        m->m_len -= hlen;
                   1025:
                   1026:        /*
1.192     jonathan 1027:         * We are about to add a fragment; increment frag count.
                   1028:         */
                   1029:        ip_nfrags++;
                   1030:
                   1031:        /*
1.1       cgd      1032:         * If first fragment to arrive, create a reassembly queue.
                   1033:         */
                   1034:        if (fp == 0) {
1.131     itojun   1035:                /*
                   1036:                 * Enforce upper bound on number of fragmented packets
                   1037:                 * for which we attempt reassembly;
                   1038:                 * If maxfrag is 0, never accept fragments.
                   1039:                 * If maxfrag is -1, accept all fragments without limitation.
                   1040:                 */
                   1041:                if (ip_maxfragpackets < 0)
                   1042:                        ;
                   1043:                else if (ip_nfragpackets >= ip_maxfragpackets)
                   1044:                        goto dropfrag;
                   1045:                ip_nfragpackets++;
1.50      thorpej  1046:                MALLOC(fp, struct ipq *, sizeof (struct ipq),
                   1047:                    M_FTABLE, M_NOWAIT);
                   1048:                if (fp == NULL)
1.1       cgd      1049:                        goto dropfrag;
1.190     jonathan 1050:                LIST_INSERT_HEAD(ipqhead, fp, ipq_q);
1.192     jonathan 1051:                fp->ipq_nfrags = 1;
1.1       cgd      1052:                fp->ipq_ttl = IPFRAGTTL;
1.25      cgd      1053:                fp->ipq_p = ipqe->ipqe_ip->ip_p;
                   1054:                fp->ipq_id = ipqe->ipqe_ip->ip_id;
1.148     matt     1055:                TAILQ_INIT(&fp->ipq_fragq);
1.25      cgd      1056:                fp->ipq_src = ipqe->ipqe_ip->ip_src;
                   1057:                fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
                   1058:                p = NULL;
1.1       cgd      1059:                goto insert;
1.192     jonathan 1060:        } else {
                   1061:                fp->ipq_nfrags++;
1.1       cgd      1062:        }
                   1063:
                   1064:        /*
                   1065:         * Find a segment which begins after this one does.
                   1066:         */
1.148     matt     1067:        for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
                   1068:            p = q, q = TAILQ_NEXT(q, ipqe_q))
1.155     itojun   1069:                if (ntohs(q->ipqe_ip->ip_off) > ntohs(ipqe->ipqe_ip->ip_off))
1.1       cgd      1070:                        break;
                   1071:
                   1072:        /*
                   1073:         * If there is a preceding segment, it may provide some of
                   1074:         * our data already.  If so, drop the data from the incoming
                   1075:         * segment.  If it provides all of our data, drop us.
                   1076:         */
1.25      cgd      1077:        if (p != NULL) {
1.155     itojun   1078:                i = ntohs(p->ipqe_ip->ip_off) + ntohs(p->ipqe_ip->ip_len) -
                   1079:                    ntohs(ipqe->ipqe_ip->ip_off);
1.1       cgd      1080:                if (i > 0) {
1.155     itojun   1081:                        if (i >= ntohs(ipqe->ipqe_ip->ip_len))
1.1       cgd      1082:                                goto dropfrag;
1.50      thorpej  1083:                        m_adj(ipqe->ipqe_m, i);
1.155     itojun   1084:                        ipqe->ipqe_ip->ip_off =
                   1085:                            htons(ntohs(ipqe->ipqe_ip->ip_off) + i);
                   1086:                        ipqe->ipqe_ip->ip_len =
                   1087:                            htons(ntohs(ipqe->ipqe_ip->ip_len) - i);
1.1       cgd      1088:                }
                   1089:        }
                   1090:
                   1091:        /*
                   1092:         * While we overlap succeeding segments trim them or,
                   1093:         * if they are completely covered, dequeue them.
                   1094:         */
1.155     itojun   1095:        for (; q != NULL &&
                   1096:            ntohs(ipqe->ipqe_ip->ip_off) + ntohs(ipqe->ipqe_ip->ip_len) >
                   1097:            ntohs(q->ipqe_ip->ip_off); q = nq) {
                   1098:                i = (ntohs(ipqe->ipqe_ip->ip_off) +
                   1099:                    ntohs(ipqe->ipqe_ip->ip_len)) - ntohs(q->ipqe_ip->ip_off);
                   1100:                if (i < ntohs(q->ipqe_ip->ip_len)) {
                   1101:                        q->ipqe_ip->ip_len =
                   1102:                            htons(ntohs(q->ipqe_ip->ip_len) - i);
                   1103:                        q->ipqe_ip->ip_off =
                   1104:                            htons(ntohs(q->ipqe_ip->ip_off) + i);
1.50      thorpej  1105:                        m_adj(q->ipqe_m, i);
1.1       cgd      1106:                        break;
                   1107:                }
1.148     matt     1108:                nq = TAILQ_NEXT(q, ipqe_q);
1.50      thorpej  1109:                m_freem(q->ipqe_m);
1.148     matt     1110:                TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72      thorpej  1111:                pool_put(&ipqent_pool, q);
1.192     jonathan 1112:                fp->ipq_nfrags--;
                   1113:                ip_nfrags--;
1.1       cgd      1114:        }
                   1115:
                   1116: insert:
                   1117:        /*
                   1118:         * Stick new segment in its place;
                   1119:         * check for complete reassembly.
                   1120:         */
1.25      cgd      1121:        if (p == NULL) {
1.148     matt     1122:                TAILQ_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
1.25      cgd      1123:        } else {
1.148     matt     1124:                TAILQ_INSERT_AFTER(&fp->ipq_fragq, p, ipqe, ipqe_q);
1.25      cgd      1125:        }
1.1       cgd      1126:        next = 0;
1.148     matt     1127:        for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
                   1128:            p = q, q = TAILQ_NEXT(q, ipqe_q)) {
1.155     itojun   1129:                if (ntohs(q->ipqe_ip->ip_off) != next)
1.1       cgd      1130:                        return (0);
1.155     itojun   1131:                next += ntohs(q->ipqe_ip->ip_len);
1.1       cgd      1132:        }
1.25      cgd      1133:        if (p->ipqe_mff)
1.1       cgd      1134:                return (0);
                   1135:
                   1136:        /*
1.41      thorpej  1137:         * Reassembly is complete.  Check for a bogus message size and
                   1138:         * concatenate fragments.
1.1       cgd      1139:         */
1.148     matt     1140:        q = TAILQ_FIRST(&fp->ipq_fragq);
1.25      cgd      1141:        ip = q->ipqe_ip;
1.41      thorpej  1142:        if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
                   1143:                ipstat.ips_toolong++;
                   1144:                ip_freef(fp);
                   1145:                return (0);
                   1146:        }
1.50      thorpej  1147:        m = q->ipqe_m;
1.1       cgd      1148:        t = m->m_next;
                   1149:        m->m_next = 0;
                   1150:        m_cat(m, t);
1.148     matt     1151:        nq = TAILQ_NEXT(q, ipqe_q);
1.72      thorpej  1152:        pool_put(&ipqent_pool, q);
1.25      cgd      1153:        for (q = nq; q != NULL; q = nq) {
1.50      thorpej  1154:                t = q->ipqe_m;
1.148     matt     1155:                nq = TAILQ_NEXT(q, ipqe_q);
1.72      thorpej  1156:                pool_put(&ipqent_pool, q);
1.1       cgd      1157:                m_cat(m, t);
                   1158:        }
1.192     jonathan 1159:        ip_nfrags -= fp->ipq_nfrags;
1.1       cgd      1160:
                   1161:        /*
                   1162:         * Create header for new ip packet by
                   1163:         * modifying header of first packet;
                   1164:         * dequeue and discard fragment reassembly header.
                   1165:         * Make header visible.
                   1166:         */
1.155     itojun   1167:        ip->ip_len = htons(next);
1.25      cgd      1168:        ip->ip_src = fp->ipq_src;
                   1169:        ip->ip_dst = fp->ipq_dst;
                   1170:        LIST_REMOVE(fp, ipq_q);
1.50      thorpej  1171:        FREE(fp, M_FTABLE);
1.131     itojun   1172:        ip_nfragpackets--;
1.1       cgd      1173:        m->m_len += (ip->ip_hl << 2);
                   1174:        m->m_data -= (ip->ip_hl << 2);
                   1175:        /* some debugging cruft by sklower, below, will go away soon */
                   1176:        if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1.109     augustss 1177:                int plen = 0;
1.50      thorpej  1178:                for (t = m; t; t = t->m_next)
                   1179:                        plen += t->m_len;
                   1180:                m->m_pkthdr.len = plen;
1.1       cgd      1181:        }
1.50      thorpej  1182:        return (m);
1.1       cgd      1183:
                   1184: dropfrag:
1.192     jonathan 1185:        if (fp != 0)
                   1186:                fp->ipq_nfrags--;
                   1187:        ip_nfrags--;
1.1       cgd      1188:        ipstat.ips_fragdropped++;
                   1189:        m_freem(m);
1.72      thorpej  1190:        pool_put(&ipqent_pool, ipqe);
1.1       cgd      1191:        return (0);
                   1192: }
                   1193:
                   1194: /*
                   1195:  * Free a fragment reassembly header and all
                   1196:  * associated datagrams.
                   1197:  */
1.8       mycroft  1198: void
1.1       cgd      1199: ip_freef(fp)
                   1200:        struct ipq *fp;
                   1201: {
1.109     augustss 1202:        struct ipqent *q, *p;
1.192     jonathan 1203:        u_int nfrags = 0;
1.1       cgd      1204:
1.75      thorpej  1205:        IPQ_LOCK_CHECK();
                   1206:
1.148     matt     1207:        for (q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL; q = p) {
                   1208:                p = TAILQ_NEXT(q, ipqe_q);
1.50      thorpej  1209:                m_freem(q->ipqe_m);
1.192     jonathan 1210:                nfrags++;
1.148     matt     1211:                TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72      thorpej  1212:                pool_put(&ipqent_pool, q);
1.1       cgd      1213:        }
1.192     jonathan 1214:
                   1215:        if (nfrags != fp->ipq_nfrags)
                   1216:            printf("ip_freef: nfrags %d != %d\n", fp->ipq_nfrags, nfrags);
                   1217:        ip_nfrags -= nfrags;
1.25      cgd      1218:        LIST_REMOVE(fp, ipq_q);
1.50      thorpej  1219:        FREE(fp, M_FTABLE);
1.131     itojun   1220:        ip_nfragpackets--;
1.1       cgd      1221: }
                   1222:
                   1223: /*
                   1224:  * IP timer processing;
                   1225:  * if a timer expires on a reassembly
                   1226:  * queue, discard it.
                   1227:  */
1.8       mycroft  1228: void
1.1       cgd      1229: ip_slowtimo()
                   1230: {
1.191     jonathan 1231:        static u_int dropscanidx = 0;
                   1232:        u_int i;
1.109     augustss 1233:        struct ipq *fp, *nfp;
1.24      mycroft  1234:        int s = splsoftnet();
1.1       cgd      1235:
1.75      thorpej  1236:        IPQ_LOCK();
1.190     jonathan 1237:        for (i = 0; i < IPREASS_NHASH; i++) {
                   1238:                for (fp = LIST_FIRST(&ipq[i]); fp != NULL; fp = nfp) {
                   1239:                        nfp = LIST_NEXT(fp, ipq_q);
                   1240:                        if (--fp->ipq_ttl == 0) {
                   1241:                                ipstat.ips_fragtimeout++;
                   1242:                                ip_freef(fp);
                   1243:                        }
1.1       cgd      1244:                }
                   1245:        }
1.131     itojun   1246:        /*
                   1247:         * If we are over the maximum number of fragments
                   1248:         * (due to the limit being lowered), drain off
1.190     jonathan 1249:         * enough to get down to the new limit. Start draining
                   1250:         * from the reassembly hashqueue most recently drained.
1.131     itojun   1251:         */
                   1252:        if (ip_maxfragpackets < 0)
                   1253:                ;
                   1254:        else {
1.190     jonathan 1255:                int wrapped = 0;
                   1256:
                   1257:                i = dropscanidx;
                   1258:                while (ip_nfragpackets > ip_maxfragpackets && wrapped == 0) {
                   1259:                        while (LIST_FIRST(&ipq[i]) != NULL)
                   1260:                                ip_freef(LIST_FIRST(&ipq[i]));
                   1261:                        if (++i >= IPREASS_NHASH) {
                   1262:                                i = 0;
                   1263:                        }
                   1264:                        /*
                   1265:                         * Dont scan forever even if fragment counters are
                   1266:                         * wrong: stop after scanning entire reassembly queue.
                   1267:                         */
                   1268:                        if (i == dropscanidx)
                   1269:                            wrapped = 1;
                   1270:                }
                   1271:                dropscanidx = i;
1.131     itojun   1272:        }
1.75      thorpej  1273:        IPQ_UNLOCK();
1.63      matt     1274: #ifdef GATEWAY
                   1275:        ipflow_slowtimo();
                   1276: #endif
1.1       cgd      1277:        splx(s);
                   1278: }
                   1279:
                   1280: /*
                   1281:  * Drain off all datagram fragments.
                   1282:  */
1.8       mycroft  1283: void
1.1       cgd      1284: ip_drain()
                   1285: {
1.190     jonathan 1286:        int i;
1.1       cgd      1287:
1.75      thorpej  1288:        /*
                   1289:         * We may be called from a device's interrupt context.  If
                   1290:         * the ipq is already busy, just bail out now.
                   1291:         */
                   1292:        if (ipq_lock_try() == 0)
                   1293:                return;
                   1294:
1.190     jonathan 1295:        for (i = 0; i < IPREASS_NHASH; i++) {
                   1296:                struct ipqhead *ipqh = &ipq[i];
                   1297:                struct ipq *fp, *nfp;
                   1298:                for (fp = LIST_FIRST(ipqh); fp != NULL; fp = nfp) {
                   1299:                        nfp = LIST_NEXT(fp, ipq_q);
                   1300:                        ip_freef(fp);
                   1301:                        ipstat.ips_fragdropped++;
                   1302:                }
1.1       cgd      1303:        }
1.75      thorpej  1304:
                   1305:        IPQ_UNLOCK();
1.1       cgd      1306: }
                   1307:
                   1308: /*
                   1309:  * Do option processing on a datagram,
                   1310:  * possibly discarding it if bad options are encountered,
                   1311:  * or forwarding it if source-routed.
                   1312:  * Returns 1 if packet has been forwarded/freed,
                   1313:  * 0 if the packet should be processed further.
                   1314:  */
1.8       mycroft  1315: int
1.1       cgd      1316: ip_dooptions(m)
                   1317:        struct mbuf *m;
                   1318: {
1.109     augustss 1319:        struct ip *ip = mtod(m, struct ip *);
                   1320:        u_char *cp, *cp0;
                   1321:        struct ip_timestamp *ipt;
                   1322:        struct in_ifaddr *ia;
1.1       cgd      1323:        int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.104     thorpej  1324:        struct in_addr dst;
1.1       cgd      1325:        n_time ntime;
                   1326:
1.13      mycroft  1327:        dst = ip->ip_dst;
1.1       cgd      1328:        cp = (u_char *)(ip + 1);
                   1329:        cnt = (ip->ip_hl << 2) - sizeof (struct ip);
                   1330:        for (; cnt > 0; cnt -= optlen, cp += optlen) {
                   1331:                opt = cp[IPOPT_OPTVAL];
                   1332:                if (opt == IPOPT_EOL)
                   1333:                        break;
                   1334:                if (opt == IPOPT_NOP)
                   1335:                        optlen = 1;
                   1336:                else {
1.113     itojun   1337:                        if (cnt < IPOPT_OLEN + sizeof(*cp)) {
                   1338:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1339:                                goto bad;
                   1340:                        }
1.1       cgd      1341:                        optlen = cp[IPOPT_OLEN];
1.114     itojun   1342:                        if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1.1       cgd      1343:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1344:                                goto bad;
                   1345:                        }
                   1346:                }
                   1347:                switch (opt) {
                   1348:
                   1349:                default:
                   1350:                        break;
                   1351:
                   1352:                /*
                   1353:                 * Source routing with record.
                   1354:                 * Find interface with current destination address.
                   1355:                 * If none on this machine then drop if strictly routed,
                   1356:                 * or do nothing if loosely routed.
                   1357:                 * Record interface address and bring up next address
                   1358:                 * component.  If strictly routed make sure next
                   1359:                 * address is on directly accessible net.
                   1360:                 */
                   1361:                case IPOPT_LSRR:
                   1362:                case IPOPT_SSRR:
1.47      cjs      1363:                        if (ip_allowsrcrt == 0) {
                   1364:                                type = ICMP_UNREACH;
                   1365:                                code = ICMP_UNREACH_NET_PROHIB;
                   1366:                                goto bad;
                   1367:                        }
1.114     itojun   1368:                        if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
                   1369:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1370:                                goto bad;
                   1371:                        }
1.1       cgd      1372:                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                   1373:                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                   1374:                                goto bad;
                   1375:                        }
                   1376:                        ipaddr.sin_addr = ip->ip_dst;
1.19      mycroft  1377:                        ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1       cgd      1378:                        if (ia == 0) {
                   1379:                                if (opt == IPOPT_SSRR) {
                   1380:                                        type = ICMP_UNREACH;
                   1381:                                        code = ICMP_UNREACH_SRCFAIL;
                   1382:                                        goto bad;
                   1383:                                }
                   1384:                                /*
                   1385:                                 * Loose routing, and not at next destination
                   1386:                                 * yet; nothing to do except forward.
                   1387:                                 */
                   1388:                                break;
                   1389:                        }
                   1390:                        off--;                  /* 0 origin */
1.112     sommerfe 1391:                        if ((off + sizeof(struct in_addr)) > optlen) {
1.1       cgd      1392:                                /*
                   1393:                                 * End of source route.  Should be for us.
                   1394:                                 */
                   1395:                                save_rte(cp, ip->ip_src);
                   1396:                                break;
                   1397:                        }
                   1398:                        /*
                   1399:                         * locate outgoing interface
                   1400:                         */
                   1401:                        bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
                   1402:                            sizeof(ipaddr.sin_addr));
1.96      thorpej  1403:                        if (opt == IPOPT_SSRR)
                   1404:                                ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
                   1405:                        else
1.1       cgd      1406:                                ia = ip_rtaddr(ipaddr.sin_addr);
                   1407:                        if (ia == 0) {
                   1408:                                type = ICMP_UNREACH;
                   1409:                                code = ICMP_UNREACH_SRCFAIL;
                   1410:                                goto bad;
                   1411:                        }
                   1412:                        ip->ip_dst = ipaddr.sin_addr;
1.20      mycroft  1413:                        bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd      1414:                            (caddr_t)(cp + off), sizeof(struct in_addr));
                   1415:                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13      mycroft  1416:                        /*
                   1417:                         * Let ip_intr's mcast routing check handle mcast pkts
                   1418:                         */
1.18      mycroft  1419:                        forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1       cgd      1420:                        break;
                   1421:
                   1422:                case IPOPT_RR:
1.114     itojun   1423:                        if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
                   1424:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1425:                                goto bad;
                   1426:                        }
1.1       cgd      1427:                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                   1428:                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                   1429:                                goto bad;
                   1430:                        }
                   1431:                        /*
                   1432:                         * If no space remains, ignore.
                   1433:                         */
                   1434:                        off--;                  /* 0 origin */
1.112     sommerfe 1435:                        if ((off + sizeof(struct in_addr)) > optlen)
1.1       cgd      1436:                                break;
                   1437:                        bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
                   1438:                            sizeof(ipaddr.sin_addr));
                   1439:                        /*
                   1440:                         * locate outgoing interface; if we're the destination,
                   1441:                         * use the incoming interface (should be same).
                   1442:                         */
1.96      thorpej  1443:                        if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
                   1444:                            == NULL &&
                   1445:                            (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1.1       cgd      1446:                                type = ICMP_UNREACH;
                   1447:                                code = ICMP_UNREACH_HOST;
                   1448:                                goto bad;
                   1449:                        }
1.20      mycroft  1450:                        bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd      1451:                            (caddr_t)(cp + off), sizeof(struct in_addr));
                   1452:                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
                   1453:                        break;
                   1454:
                   1455:                case IPOPT_TS:
                   1456:                        code = cp - (u_char *)ip;
                   1457:                        ipt = (struct ip_timestamp *)cp;
1.114     itojun   1458:                        if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
                   1459:                                code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1.1       cgd      1460:                                goto bad;
1.114     itojun   1461:                        }
                   1462:                        if (ipt->ipt_ptr < 5) {
                   1463:                                code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
                   1464:                                goto bad;
                   1465:                        }
1.15      cgd      1466:                        if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.114     itojun   1467:                                if (++ipt->ipt_oflw == 0) {
                   1468:                                        code = (u_char *)&ipt->ipt_ptr -
                   1469:                                            (u_char *)ip;
1.1       cgd      1470:                                        goto bad;
1.114     itojun   1471:                                }
1.1       cgd      1472:                                break;
                   1473:                        }
1.104     thorpej  1474:                        cp0 = (cp + ipt->ipt_ptr - 1);
1.1       cgd      1475:                        switch (ipt->ipt_flg) {
                   1476:
                   1477:                        case IPOPT_TS_TSONLY:
                   1478:                                break;
                   1479:
                   1480:                        case IPOPT_TS_TSANDADDR:
1.66      thorpej  1481:                                if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114     itojun   1482:                                    sizeof(struct in_addr) > ipt->ipt_len) {
                   1483:                                        code = (u_char *)&ipt->ipt_ptr -
                   1484:                                            (u_char *)ip;
1.1       cgd      1485:                                        goto bad;
1.114     itojun   1486:                                }
1.13      mycroft  1487:                                ipaddr.sin_addr = dst;
1.96      thorpej  1488:                                ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
                   1489:                                    m->m_pkthdr.rcvif));
1.13      mycroft  1490:                                if (ia == 0)
                   1491:                                        continue;
1.104     thorpej  1492:                                bcopy(&ia->ia_addr.sin_addr,
                   1493:                                    cp0, sizeof(struct in_addr));
1.1       cgd      1494:                                ipt->ipt_ptr += sizeof(struct in_addr);
                   1495:                                break;
                   1496:
                   1497:                        case IPOPT_TS_PRESPEC:
1.66      thorpej  1498:                                if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114     itojun   1499:                                    sizeof(struct in_addr) > ipt->ipt_len) {
                   1500:                                        code = (u_char *)&ipt->ipt_ptr -
                   1501:                                            (u_char *)ip;
1.1       cgd      1502:                                        goto bad;
1.114     itojun   1503:                                }
1.104     thorpej  1504:                                bcopy(cp0, &ipaddr.sin_addr,
1.1       cgd      1505:                                    sizeof(struct in_addr));
1.96      thorpej  1506:                                if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
                   1507:                                    == NULL)
1.1       cgd      1508:                                        continue;
                   1509:                                ipt->ipt_ptr += sizeof(struct in_addr);
                   1510:                                break;
                   1511:
                   1512:                        default:
1.114     itojun   1513:                                /* XXX can't take &ipt->ipt_flg */
                   1514:                                code = (u_char *)&ipt->ipt_ptr -
                   1515:                                    (u_char *)ip + 1;
1.1       cgd      1516:                                goto bad;
                   1517:                        }
                   1518:                        ntime = iptime();
1.107     thorpej  1519:                        cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
                   1520:                        bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1,
1.1       cgd      1521:                            sizeof(n_time));
                   1522:                        ipt->ipt_ptr += sizeof(n_time);
                   1523:                }
                   1524:        }
                   1525:        if (forward) {
1.26      thorpej  1526:                if (ip_forwsrcrt == 0) {
                   1527:                        type = ICMP_UNREACH;
                   1528:                        code = ICMP_UNREACH_SRCFAIL;
                   1529:                        goto bad;
                   1530:                }
1.1       cgd      1531:                ip_forward(m, 1);
                   1532:                return (1);
1.13      mycroft  1533:        }
                   1534:        return (0);
1.1       cgd      1535: bad:
1.13      mycroft  1536:        icmp_error(m, type, code, 0, 0);
                   1537:        ipstat.ips_badoptions++;
1.1       cgd      1538:        return (1);
                   1539: }
                   1540:
                   1541: /*
                   1542:  * Given address of next destination (final or next hop),
                   1543:  * return internet address info of interface to be used to get there.
                   1544:  */
                   1545: struct in_ifaddr *
                   1546: ip_rtaddr(dst)
                   1547:         struct in_addr dst;
                   1548: {
1.109     augustss 1549:        struct sockaddr_in *sin;
1.1       cgd      1550:
1.19      mycroft  1551:        sin = satosin(&ipforward_rt.ro_dst);
1.1       cgd      1552:
1.35      mycroft  1553:        if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1       cgd      1554:                if (ipforward_rt.ro_rt) {
                   1555:                        RTFREE(ipforward_rt.ro_rt);
                   1556:                        ipforward_rt.ro_rt = 0;
                   1557:                }
                   1558:                sin->sin_family = AF_INET;
                   1559:                sin->sin_len = sizeof(*sin);
                   1560:                sin->sin_addr = dst;
                   1561:
                   1562:                rtalloc(&ipforward_rt);
                   1563:        }
                   1564:        if (ipforward_rt.ro_rt == 0)
                   1565:                return ((struct in_ifaddr *)0);
1.19      mycroft  1566:        return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1       cgd      1567: }
                   1568:
                   1569: /*
                   1570:  * Save incoming source route for use in replies,
                   1571:  * to be picked up later by ip_srcroute if the receiver is interested.
                   1572:  */
1.13      mycroft  1573: void
1.1       cgd      1574: save_rte(option, dst)
                   1575:        u_char *option;
                   1576:        struct in_addr dst;
                   1577: {
                   1578:        unsigned olen;
                   1579:
                   1580:        olen = option[IPOPT_OLEN];
                   1581: #ifdef DIAGNOSTIC
                   1582:        if (ipprintfs)
1.39      christos 1583:                printf("save_rte: olen %d\n", olen);
1.89      itojun   1584: #endif /* 0 */
1.1       cgd      1585:        if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
                   1586:                return;
                   1587:        bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
                   1588:        ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
                   1589:        ip_srcrt.dst = dst;
                   1590: }
                   1591:
                   1592: /*
                   1593:  * Retrieve incoming source route for use in replies,
                   1594:  * in the same form used by setsockopt.
                   1595:  * The first hop is placed before the options, will be removed later.
                   1596:  */
                   1597: struct mbuf *
                   1598: ip_srcroute()
                   1599: {
1.109     augustss 1600:        struct in_addr *p, *q;
                   1601:        struct mbuf *m;
1.1       cgd      1602:
                   1603:        if (ip_nhops == 0)
                   1604:                return ((struct mbuf *)0);
                   1605:        m = m_get(M_DONTWAIT, MT_SOOPTS);
                   1606:        if (m == 0)
                   1607:                return ((struct mbuf *)0);
                   1608:
1.164     matt     1609:        MCLAIM(m, &inetdomain.dom_mowner);
1.13      mycroft  1610: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1       cgd      1611:
                   1612:        /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
                   1613:        m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
                   1614:            OPTSIZ;
                   1615: #ifdef DIAGNOSTIC
                   1616:        if (ipprintfs)
1.39      christos 1617:                printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1       cgd      1618: #endif
                   1619:
                   1620:        /*
                   1621:         * First save first hop for return route
                   1622:         */
                   1623:        p = &ip_srcrt.route[ip_nhops - 1];
                   1624:        *(mtod(m, struct in_addr *)) = *p--;
                   1625: #ifdef DIAGNOSTIC
                   1626:        if (ipprintfs)
1.39      christos 1627:                printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1       cgd      1628: #endif
                   1629:
                   1630:        /*
                   1631:         * Copy option fields and padding (nop) to mbuf.
                   1632:         */
                   1633:        ip_srcrt.nop = IPOPT_NOP;
                   1634:        ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
                   1635:        bcopy((caddr_t)&ip_srcrt.nop,
                   1636:            mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
                   1637:        q = (struct in_addr *)(mtod(m, caddr_t) +
                   1638:            sizeof(struct in_addr) + OPTSIZ);
                   1639: #undef OPTSIZ
                   1640:        /*
                   1641:         * Record return path as an IP source route,
                   1642:         * reversing the path (pointers are now aligned).
                   1643:         */
                   1644:        while (p >= ip_srcrt.route) {
                   1645: #ifdef DIAGNOSTIC
                   1646:                if (ipprintfs)
1.39      christos 1647:                        printf(" %x", ntohl(q->s_addr));
1.1       cgd      1648: #endif
                   1649:                *q++ = *p--;
                   1650:        }
                   1651:        /*
                   1652:         * Last hop goes to final destination.
                   1653:         */
                   1654:        *q = ip_srcrt.dst;
                   1655: #ifdef DIAGNOSTIC
                   1656:        if (ipprintfs)
1.39      christos 1657:                printf(" %x\n", ntohl(q->s_addr));
1.1       cgd      1658: #endif
                   1659:        return (m);
                   1660: }
                   1661:
                   1662: /*
                   1663:  * Strip out IP options, at higher
                   1664:  * level protocol in the kernel.
                   1665:  * Second argument is buffer to which options
                   1666:  * will be moved, and return value is their length.
                   1667:  * XXX should be deleted; last arg currently ignored.
                   1668:  */
1.8       mycroft  1669: void
1.1       cgd      1670: ip_stripoptions(m, mopt)
1.109     augustss 1671:        struct mbuf *m;
1.1       cgd      1672:        struct mbuf *mopt;
                   1673: {
1.109     augustss 1674:        int i;
1.1       cgd      1675:        struct ip *ip = mtod(m, struct ip *);
1.109     augustss 1676:        caddr_t opts;
1.1       cgd      1677:        int olen;
                   1678:
1.79      mycroft  1679:        olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1       cgd      1680:        opts = (caddr_t)(ip + 1);
                   1681:        i = m->m_len - (sizeof (struct ip) + olen);
                   1682:        bcopy(opts  + olen, opts, (unsigned)i);
                   1683:        m->m_len -= olen;
                   1684:        if (m->m_flags & M_PKTHDR)
                   1685:                m->m_pkthdr.len -= olen;
1.155     itojun   1686:        ip->ip_len = htons(ntohs(ip->ip_len) - olen);
1.79      mycroft  1687:        ip->ip_hl = sizeof (struct ip) >> 2;
1.1       cgd      1688: }
                   1689:
1.139     matt     1690: const int inetctlerrmap[PRC_NCMDS] = {
1.1       cgd      1691:        0,              0,              0,              0,
                   1692:        0,              EMSGSIZE,       EHOSTDOWN,      EHOSTUNREACH,
                   1693:        EHOSTUNREACH,   EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
                   1694:        EMSGSIZE,       EHOSTUNREACH,   0,              0,
                   1695:        0,              0,              0,              0,
                   1696:        ENOPROTOOPT
                   1697: };
                   1698:
                   1699: /*
                   1700:  * Forward a packet.  If some error occurs return the sender
                   1701:  * an icmp packet.  Note we can't always generate a meaningful
                   1702:  * icmp message because icmp doesn't have a large enough repertoire
                   1703:  * of codes and types.
                   1704:  *
                   1705:  * If not forwarding, just drop the packet.  This could be confusing
                   1706:  * if ipforwarding was zero but some routing protocol was advancing
                   1707:  * us as a gateway to somewhere.  However, we must let the routing
                   1708:  * protocol deal with that.
                   1709:  *
                   1710:  * The srcrt parameter indicates whether the packet is being forwarded
                   1711:  * via a source route.
                   1712:  */
1.13      mycroft  1713: void
1.1       cgd      1714: ip_forward(m, srcrt)
                   1715:        struct mbuf *m;
                   1716:        int srcrt;
                   1717: {
1.109     augustss 1718:        struct ip *ip = mtod(m, struct ip *);
                   1719:        struct sockaddr_in *sin;
                   1720:        struct rtentry *rt;
1.28      christos 1721:        int error, type = 0, code = 0;
1.1       cgd      1722:        struct mbuf *mcopy;
1.13      mycroft  1723:        n_long dest;
                   1724:        struct ifnet *destifp;
1.173     jonathan 1725: #if defined(IPSEC) || defined(FAST_IPSEC)
1.89      itojun   1726:        struct ifnet dummyifp;
                   1727: #endif
1.164     matt     1728:
                   1729:        /*
                   1730:         * We are now in the output path.
                   1731:         */
                   1732:        MCLAIM(m, &ip_tx_mowner);
1.135     thorpej  1733:
                   1734:        /*
                   1735:         * Clear any in-bound checksum flags for this packet.
                   1736:         */
                   1737:        m->m_pkthdr.csum_flags = 0;
1.1       cgd      1738:
1.13      mycroft  1739:        dest = 0;
1.1       cgd      1740: #ifdef DIAGNOSTIC
                   1741:        if (ipprintfs)
1.70      thorpej  1742:                printf("forward: src %2.2x dst %2.2x ttl %x\n",
                   1743:                    ntohl(ip->ip_src.s_addr),
                   1744:                    ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
1.1       cgd      1745: #endif
1.93      sommerfe 1746:        if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1.1       cgd      1747:                ipstat.ips_cantforward++;
                   1748:                m_freem(m);
                   1749:                return;
                   1750:        }
                   1751:        if (ip->ip_ttl <= IPTTLDEC) {
1.13      mycroft  1752:                icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1       cgd      1753:                return;
                   1754:        }
                   1755:        ip->ip_ttl -= IPTTLDEC;
                   1756:
1.19      mycroft  1757:        sin = satosin(&ipforward_rt.ro_dst);
1.1       cgd      1758:        if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35      mycroft  1759:            !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1       cgd      1760:                if (ipforward_rt.ro_rt) {
                   1761:                        RTFREE(ipforward_rt.ro_rt);
                   1762:                        ipforward_rt.ro_rt = 0;
                   1763:                }
                   1764:                sin->sin_family = AF_INET;
1.35      mycroft  1765:                sin->sin_len = sizeof(struct sockaddr_in);
1.1       cgd      1766:                sin->sin_addr = ip->ip_dst;
                   1767:
                   1768:                rtalloc(&ipforward_rt);
                   1769:                if (ipforward_rt.ro_rt == 0) {
1.13      mycroft  1770:                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1.1       cgd      1771:                        return;
                   1772:                }
                   1773:                rt = ipforward_rt.ro_rt;
                   1774:        }
                   1775:
                   1776:        /*
1.34      mycroft  1777:         * Save at most 68 bytes of the packet in case
1.1       cgd      1778:         * we need to generate an ICMP message to the src.
1.119     itojun   1779:         * Pullup to avoid sharing mbuf cluster between m and mcopy.
1.1       cgd      1780:         */
1.155     itojun   1781:        mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1.119     itojun   1782:        if (mcopy)
                   1783:                mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1.1       cgd      1784:
                   1785:        /*
                   1786:         * If forwarding packet using same interface that it came in on,
                   1787:         * perhaps should send a redirect to sender to shortcut a hop.
                   1788:         * Only send redirect if source is sending directly to us,
                   1789:         * and if packet was not source routed (or has any options).
                   1790:         * Also, don't send redirect if forwarding using a default route
                   1791:         * or a route modified by a redirect.
                   1792:         */
                   1793:        if (rt->rt_ifp == m->m_pkthdr.rcvif &&
                   1794:            (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35      mycroft  1795:            !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1       cgd      1796:            ipsendredirects && !srcrt) {
1.19      mycroft  1797:                if (rt->rt_ifa &&
                   1798:                    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
                   1799:                    ifatoia(rt->rt_ifa)->ia_subnet) {
1.77      thorpej  1800:                        if (rt->rt_flags & RTF_GATEWAY)
                   1801:                                dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
                   1802:                        else
                   1803:                                dest = ip->ip_dst.s_addr;
                   1804:                        /*
                   1805:                         * Router requirements says to only send host
                   1806:                         * redirects.
                   1807:                         */
                   1808:                        type = ICMP_REDIRECT;
                   1809:                        code = ICMP_REDIRECT_HOST;
1.1       cgd      1810: #ifdef DIAGNOSTIC
1.77      thorpej  1811:                        if (ipprintfs)
                   1812:                                printf("redirect (%d) to %x\n", code,
                   1813:                                    (u_int32_t)dest);
1.1       cgd      1814: #endif
                   1815:                }
                   1816:        }
                   1817:
1.27      thorpej  1818:        error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1.173     jonathan 1819:            (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1.174     itojun   1820:            (struct ip_moptions *)NULL, (struct socket *)NULL);
1.173     jonathan 1821:
1.1       cgd      1822:        if (error)
                   1823:                ipstat.ips_cantforward++;
                   1824:        else {
                   1825:                ipstat.ips_forward++;
                   1826:                if (type)
                   1827:                        ipstat.ips_redirectsent++;
                   1828:                else {
1.63      matt     1829:                        if (mcopy) {
                   1830: #ifdef GATEWAY
1.64      thorpej  1831:                                if (mcopy->m_flags & M_CANFASTFWD)
                   1832:                                        ipflow_create(&ipforward_rt, mcopy);
1.63      matt     1833: #endif
1.1       cgd      1834:                                m_freem(mcopy);
1.63      matt     1835:                        }
1.1       cgd      1836:                        return;
                   1837:                }
                   1838:        }
                   1839:        if (mcopy == NULL)
                   1840:                return;
1.13      mycroft  1841:        destifp = NULL;
                   1842:
1.1       cgd      1843:        switch (error) {
                   1844:
                   1845:        case 0:                         /* forwarded, but need redirect */
                   1846:                /* type, code set above */
                   1847:                break;
                   1848:
                   1849:        case ENETUNREACH:               /* shouldn't happen, checked above */
                   1850:        case EHOSTUNREACH:
                   1851:        case ENETDOWN:
                   1852:        case EHOSTDOWN:
                   1853:        default:
                   1854:                type = ICMP_UNREACH;
                   1855:                code = ICMP_UNREACH_HOST;
                   1856:                break;
                   1857:
                   1858:        case EMSGSIZE:
                   1859:                type = ICMP_UNREACH;
                   1860:                code = ICMP_UNREACH_NEEDFRAG;
1.173     jonathan 1861: #if !defined(IPSEC) && !defined(FAST_IPSEC)
1.13      mycroft  1862:                if (ipforward_rt.ro_rt)
                   1863:                        destifp = ipforward_rt.ro_rt->rt_ifp;
1.89      itojun   1864: #else
                   1865:                /*
                   1866:                 * If the packet is routed over IPsec tunnel, tell the
                   1867:                 * originator the tunnel MTU.
                   1868:                 *      tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
                   1869:                 * XXX quickhack!!!
                   1870:                 */
                   1871:                if (ipforward_rt.ro_rt) {
                   1872:                        struct secpolicy *sp;
                   1873:                        int ipsecerror;
1.95      itojun   1874:                        size_t ipsechdr;
1.89      itojun   1875:                        struct route *ro;
                   1876:
                   1877:                        sp = ipsec4_getpolicybyaddr(mcopy,
1.170     itojun   1878:                            IPSEC_DIR_OUTBOUND, IP_FORWARDING,
                   1879:                            &ipsecerror);
1.89      itojun   1880:
                   1881:                        if (sp == NULL)
                   1882:                                destifp = ipforward_rt.ro_rt->rt_ifp;
                   1883:                        else {
                   1884:                                /* count IPsec header size */
1.95      itojun   1885:                                ipsechdr = ipsec4_hdrsiz(mcopy,
1.170     itojun   1886:                                    IPSEC_DIR_OUTBOUND, NULL);
1.89      itojun   1887:
                   1888:                                /*
                   1889:                                 * find the correct route for outer IPv4
                   1890:                                 * header, compute tunnel MTU.
                   1891:                                 *
                   1892:                                 * XXX BUG ALERT
                   1893:                                 * The "dummyifp" code relies upon the fact
                   1894:                                 * that icmp_error() touches only ifp->if_mtu.
                   1895:                                 */
                   1896:                                /*XXX*/
                   1897:                                destifp = NULL;
                   1898:                                if (sp->req != NULL
1.95      itojun   1899:                                 && sp->req->sav != NULL
                   1900:                                 && sp->req->sav->sah != NULL) {
                   1901:                                        ro = &sp->req->sav->sah->sa_route;
1.89      itojun   1902:                                        if (ro->ro_rt && ro->ro_rt->rt_ifp) {
                   1903:                                                dummyifp.if_mtu =
1.151     itojun   1904:                                                    ro->ro_rt->rt_rmx.rmx_mtu ?
                   1905:                                                    ro->ro_rt->rt_rmx.rmx_mtu :
1.89      itojun   1906:                                                    ro->ro_rt->rt_ifp->if_mtu;
                   1907:                                                dummyifp.if_mtu -= ipsechdr;
                   1908:                                                destifp = &dummyifp;
                   1909:                                        }
                   1910:                                }
                   1911:
1.173     jonathan 1912: #ifdef IPSEC
1.89      itojun   1913:                                key_freesp(sp);
1.173     jonathan 1914: #else
                   1915:                                KEY_FREESP(&sp);
                   1916: #endif
1.89      itojun   1917:                        }
                   1918:                }
                   1919: #endif /*IPSEC*/
1.1       cgd      1920:                ipstat.ips_cantfrag++;
                   1921:                break;
                   1922:
                   1923:        case ENOBUFS:
1.143     itojun   1924: #if 1
                   1925:                /*
                   1926:                 * a router should not generate ICMP_SOURCEQUENCH as
                   1927:                 * required in RFC1812 Requirements for IP Version 4 Routers.
                   1928:                 * source quench could be a big problem under DoS attacks,
1.149     wiz      1929:                 * or if the underlying interface is rate-limited.
1.143     itojun   1930:                 */
                   1931:                if (mcopy)
                   1932:                        m_freem(mcopy);
                   1933:                return;
                   1934: #else
1.1       cgd      1935:                type = ICMP_SOURCEQUENCH;
                   1936:                code = 0;
                   1937:                break;
1.143     itojun   1938: #endif
1.1       cgd      1939:        }
1.13      mycroft  1940:        icmp_error(mcopy, type, code, dest, destifp);
1.44      thorpej  1941: }
                   1942:
                   1943: void
                   1944: ip_savecontrol(inp, mp, ip, m)
1.109     augustss 1945:        struct inpcb *inp;
                   1946:        struct mbuf **mp;
                   1947:        struct ip *ip;
                   1948:        struct mbuf *m;
1.44      thorpej  1949: {
                   1950:
                   1951:        if (inp->inp_socket->so_options & SO_TIMESTAMP) {
                   1952:                struct timeval tv;
                   1953:
                   1954:                microtime(&tv);
                   1955:                *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
                   1956:                    SCM_TIMESTAMP, SOL_SOCKET);
                   1957:                if (*mp)
                   1958:                        mp = &(*mp)->m_next;
                   1959:        }
                   1960:        if (inp->inp_flags & INP_RECVDSTADDR) {
                   1961:                *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
                   1962:                    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
                   1963:                if (*mp)
                   1964:                        mp = &(*mp)->m_next;
                   1965:        }
                   1966: #ifdef notyet
                   1967:        /*
                   1968:         * XXX
                   1969:         * Moving these out of udp_input() made them even more broken
                   1970:         * than they already were.
                   1971:         *      - fenner@parc.xerox.com
                   1972:         */
                   1973:        /* options were tossed already */
                   1974:        if (inp->inp_flags & INP_RECVOPTS) {
                   1975:                *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
                   1976:                    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
                   1977:                if (*mp)
                   1978:                        mp = &(*mp)->m_next;
                   1979:        }
                   1980:        /* ip_srcroute doesn't do what we want here, need to fix */
                   1981:        if (inp->inp_flags & INP_RECVRETOPTS) {
                   1982:                *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
                   1983:                    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
                   1984:                if (*mp)
                   1985:                        mp = &(*mp)->m_next;
                   1986:        }
                   1987: #endif
                   1988:        if (inp->inp_flags & INP_RECVIF) {
                   1989:                struct sockaddr_dl sdl;
                   1990:
                   1991:                sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
                   1992:                sdl.sdl_family = AF_LINK;
                   1993:                sdl.sdl_index = m->m_pkthdr.rcvif ?
                   1994:                    m->m_pkthdr.rcvif->if_index : 0;
                   1995:                sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
                   1996:                *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
                   1997:                    IP_RECVIF, IPPROTO_IP);
                   1998:                if (*mp)
                   1999:                        mp = &(*mp)->m_next;
                   2000:        }
1.13      mycroft  2001: }
                   2002:
1.189     atatat   2003: /*
                   2004:  * sysctl helper routine for net.inet.ip.mtudisctimeout.  checks the
                   2005:  * range of the new value and tweaks timers if it changes.
                   2006:  */
                   2007: static int
                   2008: sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1.13      mycroft  2009: {
1.189     atatat   2010:        int error, tmp;
                   2011:        struct sysctlnode node;
                   2012:
                   2013:        node = *rnode;
                   2014:        tmp = ip_mtudisc_timeout;
                   2015:        node.sysctl_data = &tmp;
                   2016:        error = sysctl_lookup(SYSCTLFN_CALL(&node));
                   2017:        if (error || newp == NULL)
                   2018:                return (error);
                   2019:        if (tmp < 0)
                   2020:                return (EINVAL);
1.52      thorpej  2021:
1.189     atatat   2022:        ip_mtudisc_timeout = tmp;
                   2023:        rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
                   2024:
                   2025:        return (0);
                   2026: }
1.54      lukem    2027:
1.65      matt     2028: #ifdef GATEWAY
1.189     atatat   2029: /*
                   2030:  * sysctl helper routine for net.inet.ip.maxflows.  apparently if
                   2031:  * maxflows is even looked up, we "reap flows".
                   2032:  */
                   2033: static int
                   2034: sysctl_net_inet_ip_maxflows(SYSCTLFN_ARGS)
                   2035: {
                   2036:        int s;
1.67      thorpej  2037:
1.189     atatat   2038:        s = sysctl_lookup(SYSCTLFN_CALL(rnode));
                   2039:        if (s)
                   2040:                return (s);
                   2041:
                   2042:        s = splsoftnet();
                   2043:        ipflow_reap(0);
                   2044:        splx(s);
1.144     martin   2045:
1.189     atatat   2046:        return (0);
                   2047: }
                   2048: #endif /* GATEWAY */
1.117     tron     2049:
1.131     itojun   2050:
1.189     atatat   2051: SYSCTL_SETUP(sysctl_net_inet_ip_setup, "sysctl net.inet.ip subtree setup")
                   2052: {
                   2053:        extern int subnetsarelocal, hostzeroisbroadcast;
1.180     jonathan 2054:
1.189     atatat   2055:        sysctl_createv(SYSCTL_PERMANENT,
                   2056:                       CTLTYPE_NODE, "net", NULL,
                   2057:                       NULL, 0, NULL, 0,
                   2058:                       CTL_NET, CTL_EOL);
                   2059:        sysctl_createv(SYSCTL_PERMANENT,
                   2060:                       CTLTYPE_NODE, "inet", NULL,
                   2061:                       NULL, 0, NULL, 0,
                   2062:                       CTL_NET, PF_INET, CTL_EOL);
                   2063:        sysctl_createv(SYSCTL_PERMANENT,
                   2064:                       CTLTYPE_NODE, "ip", NULL,
                   2065:                       NULL, 0, NULL, 0,
                   2066:                       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
                   2067:
                   2068:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2069:                       CTLTYPE_INT, "forwarding", NULL,
                   2070:                       NULL, 0, &ipforwarding, 0,
                   2071:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2072:                       IPCTL_FORWARDING, CTL_EOL);
                   2073:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2074:                       CTLTYPE_INT, "redirect", NULL,
                   2075:                       NULL, 0, &ipsendredirects, 0,
                   2076:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2077:                       IPCTL_SENDREDIRECTS, CTL_EOL);
                   2078:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2079:                       CTLTYPE_INT, "ttl", NULL,
                   2080:                       NULL, 0, &ip_defttl, 0,
                   2081:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2082:                       IPCTL_DEFTTL, CTL_EOL);
                   2083: #ifdef IPCTL_DEFMTU
                   2084:        sysctl_createv(SYSCTL_PERMANENT /* |SYSCTL_READWRITE? */,
                   2085:                       CTLTYPE_INT, "mtu", NULL,
                   2086:                       NULL, 0, &ip_mtu, 0,
                   2087:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2088:                       IPCTL_DEFMTU, CTL_EOL);
                   2089: #endif /* IPCTL_DEFMTU */
                   2090:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READONLY1,
                   2091:                       CTLTYPE_INT, "forwsrcrt", NULL,
                   2092:                       NULL, 0, &ip_forwsrcrt, 0,
                   2093:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2094:                       IPCTL_FORWSRCRT, CTL_EOL);
                   2095:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2096:                       CTLTYPE_INT, "directed-broadcast", NULL,
                   2097:                       NULL, 0, &ip_directedbcast, 0,
                   2098:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2099:                       IPCTL_DIRECTEDBCAST, CTL_EOL);
                   2100:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2101:                       CTLTYPE_INT, "allowsrcrt", NULL,
                   2102:                       NULL, 0, &ip_allowsrcrt, 0,
                   2103:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2104:                       IPCTL_ALLOWSRCRT, CTL_EOL);
                   2105:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2106:                       CTLTYPE_INT, "subnetsarelocal", NULL,
                   2107:                       NULL, 0, &subnetsarelocal, 0,
                   2108:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2109:                       IPCTL_SUBNETSARELOCAL, CTL_EOL);
                   2110:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2111:                       CTLTYPE_INT, "mtudisc", NULL,
                   2112:                       NULL, 0, &ip_mtudisc, 0,
                   2113:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2114:                       IPCTL_MTUDISC, CTL_EOL);
                   2115:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2116:                       CTLTYPE_INT, "anonportmin", NULL,
                   2117:                       sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
                   2118:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2119:                       IPCTL_ANONPORTMIN, CTL_EOL);
                   2120:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2121:                       CTLTYPE_INT, "anonportmax", NULL,
                   2122:                       sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
                   2123:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2124:                       IPCTL_ANONPORTMAX, CTL_EOL);
                   2125:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2126:                       CTLTYPE_INT, "mtudisctimeout", NULL,
                   2127:                       sysctl_net_inet_ip_pmtudto, 0, &ip_mtudisc_timeout, 0,
                   2128:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2129:                       IPCTL_MTUDISCTIMEOUT, CTL_EOL);
                   2130: #ifdef GATEWAY
                   2131:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2132:                       CTLTYPE_INT, "maxflows", NULL,
                   2133:                       sysctl_net_inet_ip_maxflows, 0, &ip_maxflows, 0,
                   2134:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2135:                       IPCTL_MAXFLOWS, CTL_EOL);
                   2136: #endif /* GATEWAY */
                   2137:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2138:                       CTLTYPE_INT, "hostzerobroadcast", NULL,
                   2139:                       NULL, 0, &hostzeroisbroadcast, 0,
                   2140:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2141:                       IPCTL_HOSTZEROBROADCAST, CTL_EOL);
                   2142: #if NGIF > 0
                   2143:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2144:                       CTLTYPE_INT, "gifttl", NULL,
                   2145:                       NULL, 0, &ip_gif_ttl, 0,
                   2146:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2147:                       IPCTL_GIF_TTL, CTL_EOL);
                   2148: #endif /* NGIF */
                   2149: #ifndef IPNOPRIVPORTS
                   2150:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2151:                       CTLTYPE_INT, "lowportmin", NULL,
                   2152:                       sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
                   2153:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2154:                       IPCTL_LOWPORTMIN, CTL_EOL);
                   2155:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2156:                       CTLTYPE_INT, "lowportmax", NULL,
                   2157:                       sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
                   2158:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2159:                       IPCTL_LOWPORTMAX, CTL_EOL);
                   2160: #endif /* IPNOPRIVPORTS */
                   2161:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2162:                       CTLTYPE_INT, "maxfragpackets", NULL,
                   2163:                       NULL, 0, &ip_maxfragpackets, 0,
                   2164:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2165:                       IPCTL_MAXFRAGPACKETS, CTL_EOL);
                   2166: #if NGRE > 0
                   2167:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2168:                       CTLTYPE_INT, "grettl", NULL,
                   2169:                       NULL, 0, &ip_gre_ttl, 0,
                   2170:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2171:                       IPCTL_GRE_TTL, CTL_EOL);
                   2172: #endif /* NGRE */
                   2173:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2174:                       CTLTYPE_INT, "checkinterface", NULL,
                   2175:                       NULL, 0, &ip_checkinterface, 0,
                   2176:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2177:                       IPCTL_CHECKINTERFACE, CTL_EOL);
                   2178:        sysctl_createv(SYSCTL_PERMANENT|SYSCTL_READWRITE,
                   2179:                       CTLTYPE_INT, "random_id", NULL,
                   2180:                       NULL, 0, &ip_do_randomid, 0,
                   2181:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2182:                       IPCTL_RANDOMID, CTL_EOL);
1.1       cgd      2183: }

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