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Annotation of src/sys/netinet/ip_input.c, Revision 1.224.2.5

1.224.2.5! yamt        1: /*     $NetBSD: ip_input.c,v 1.224.2.4 2006/09/03 15:25:42 yamt 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>
1.224.2.5! yamt      101: __KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.224.2.4 2006/09/03 15:25:42 yamt 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>
1.224.2.5! yamt      124: #include <sys/kauth.h>
1.1       cgd       125:
1.5       mycroft   126: #include <net/if.h>
1.44      thorpej   127: #include <net/if_dl.h>
1.5       mycroft   128: #include <net/route.h>
1.45      mrg       129: #include <net/pfil.h>
1.1       cgd       130:
1.5       mycroft   131: #include <netinet/in.h>
                    132: #include <netinet/in_systm.h>
                    133: #include <netinet/ip.h>
                    134: #include <netinet/in_pcb.h>
1.215     yamt      135: #include <netinet/in_proto.h>
1.5       mycroft   136: #include <netinet/in_var.h>
                    137: #include <netinet/ip_var.h>
                    138: #include <netinet/ip_icmp.h>
1.89      itojun    139: /* just for gif_ttl */
                    140: #include <netinet/in_gif.h>
                    141: #include "gif.h"
1.144     martin    142: #include <net/if_gre.h>
                    143: #include "gre.h"
1.111     jdolecek  144:
                    145: #ifdef MROUTING
                    146: #include <netinet/ip_mroute.h>
                    147: #endif
1.89      itojun    148:
                    149: #ifdef IPSEC
                    150: #include <netinet6/ipsec.h>
                    151: #include <netkey/key.h>
                    152: #endif
1.173     jonathan  153: #ifdef FAST_IPSEC
                    154: #include <netipsec/ipsec.h>
                    155: #include <netipsec/key.h>
                    156: #endif /* FAST_IPSEC*/
1.44      thorpej   157:
1.1       cgd       158: #ifndef        IPFORWARDING
                    159: #ifdef GATEWAY
                    160: #define        IPFORWARDING    1       /* forward IP packets not for us */
                    161: #else /* GATEWAY */
                    162: #define        IPFORWARDING    0       /* don't forward IP packets not for us */
                    163: #endif /* GATEWAY */
                    164: #endif /* IPFORWARDING */
                    165: #ifndef        IPSENDREDIRECTS
                    166: #define        IPSENDREDIRECTS 1
                    167: #endif
1.26      thorpej   168: #ifndef IPFORWSRCRT
1.47      cjs       169: #define        IPFORWSRCRT     1       /* forward source-routed packets */
                    170: #endif
                    171: #ifndef IPALLOWSRCRT
1.48      mrg       172: #define        IPALLOWSRCRT    1       /* allow source-routed packets */
1.26      thorpej   173: #endif
1.53      kml       174: #ifndef IPMTUDISC
1.153     itojun    175: #define IPMTUDISC      1
1.53      kml       176: #endif
1.60      kml       177: #ifndef IPMTUDISCTIMEOUT
1.61      kml       178: #define IPMTUDISCTIMEOUT (10 * 60)     /* as per RFC 1191 */
1.60      kml       179: #endif
1.53      kml       180:
1.27      thorpej   181: /*
                    182:  * Note: DIRECTED_BROADCAST is handled this way so that previous
                    183:  * configuration using this option will Just Work.
                    184:  */
                    185: #ifndef IPDIRECTEDBCAST
                    186: #ifdef DIRECTED_BROADCAST
                    187: #define IPDIRECTEDBCAST        1
                    188: #else
                    189: #define        IPDIRECTEDBCAST 0
                    190: #endif /* DIRECTED_BROADCAST */
                    191: #endif /* IPDIRECTEDBCAST */
1.1       cgd       192: int    ipforwarding = IPFORWARDING;
                    193: int    ipsendredirects = IPSENDREDIRECTS;
1.13      mycroft   194: int    ip_defttl = IPDEFTTL;
1.26      thorpej   195: int    ip_forwsrcrt = IPFORWSRCRT;
1.27      thorpej   196: int    ip_directedbcast = IPDIRECTEDBCAST;
1.47      cjs       197: int    ip_allowsrcrt = IPALLOWSRCRT;
1.53      kml       198: int    ip_mtudisc = IPMTUDISC;
1.156     itojun    199: int    ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
1.1       cgd       200: #ifdef DIAGNOSTIC
                    201: int    ipprintfs = 0;
                    202: #endif
1.184     jonathan  203:
                    204: int    ip_do_randomid = 0;
                    205:
1.165     christos  206: /*
                    207:  * XXX - Setting ip_checkinterface mostly implements the receive side of
                    208:  * the Strong ES model described in RFC 1122, but since the routing table
                    209:  * and transmit implementation do not implement the Strong ES model,
                    210:  * setting this to 1 results in an odd hybrid.
                    211:  *
                    212:  * XXX - ip_checkinterface currently must be disabled if you use ipnat
                    213:  * to translate the destination address to another local interface.
                    214:  *
                    215:  * XXX - ip_checkinterface must be disabled if you add IP aliases
                    216:  * to the loopback interface instead of the interface where the
                    217:  * packets for those addresses are received.
                    218:  */
                    219: int    ip_checkinterface = 0;
                    220:
1.1       cgd       221:
1.60      kml       222: struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
                    223:
1.1       cgd       224: int    ipqmaxlen = IFQ_MAXLEN;
1.150     matt      225: u_long in_ifaddrhash;                          /* size of hash table - 1 */
                    226: int    in_ifaddrentries;                       /* total number of addrs */
1.212     perry     227: struct in_ifaddrhead in_ifaddrhead;
1.57      tls       228: struct in_ifaddrhashhead *in_ifaddrhashtbl;
1.166     matt      229: u_long in_multihash;                           /* size of hash table - 1 */
                    230: int    in_multientries;                        /* total number of addrs */
                    231: struct in_multihashhead *in_multihashtbl;
1.13      mycroft   232: struct ifqueue ipintrq;
1.63      matt      233: struct ipstat  ipstat;
1.183     jonathan  234: uint16_t ip_id;
1.75      thorpej   235:
1.121     thorpej   236: #ifdef PFIL_HOOKS
                    237: struct pfil_head inet_pfil_hook;
                    238: #endif
                    239:
1.194     jonathan  240: /*
                    241:  * Cached copy of nmbclusters. If nbclusters is different,
                    242:  * recalculate IP parameters derived from nmbclusters.
                    243:  */
                    244: static int     ip_nmbclusters;                 /* copy of nmbclusters */
1.210     perry     245: static void    ip_nmbclusters_changed(void);   /* recalc limits */
1.194     jonathan  246:
1.195     thorpej   247: #define CHECK_NMBCLUSTER_PARAMS()                              \
                    248: do {                                                           \
                    249:        if (__predict_false(ip_nmbclusters != nmbclusters))     \
                    250:                ip_nmbclusters_changed();                       \
                    251: } while (/*CONSTCOND*/0)
1.194     jonathan  252:
1.190     jonathan  253: /* IP datagram reassembly queues (hashed) */
                    254: #define IPREASS_NHASH_LOG2      6
                    255: #define IPREASS_NHASH           (1 << IPREASS_NHASH_LOG2)
                    256: #define IPREASS_HMASK           (IPREASS_NHASH - 1)
                    257: #define IPREASS_HASH(x,y) \
                    258:        (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
                    259: struct ipqhead ipq[IPREASS_NHASH];
1.75      thorpej   260: int    ipq_locked;
1.212     perry     261: static int     ip_nfragpackets;        /* packets in reass queue */
1.194     jonathan  262: static int     ip_nfrags;              /* total fragments in reass queues */
                    263:
                    264: int    ip_maxfragpackets = 200;        /* limit on packets. XXX sysctl */
                    265: int    ip_maxfrags;                    /* limit on fragments. XXX sysctl */
                    266:
                    267:
                    268: /*
                    269:  * Additive-Increase/Multiplicative-Decrease (AIMD) strategy for
                    270:  * IP reassembly queue buffer managment.
1.212     perry     271:  *
1.194     jonathan  272:  * We keep a count of total IP fragments (NB: not fragmented packets!)
                    273:  * awaiting reassembly (ip_nfrags) and a limit (ip_maxfrags) on fragments.
                    274:  * If ip_nfrags exceeds ip_maxfrags the limit, we drop half the
                    275:  * total fragments in  reassembly queues.This AIMD policy avoids
                    276:  * repeatedly deleting single packets under heavy fragmentation load
                    277:  * (e.g., from lossy NFS peers).
                    278:  */
1.212     perry     279: static u_int   ip_reass_ttl_decr(u_int ticks);
1.210     perry     280: static void    ip_reass_drophalf(void);
1.194     jonathan  281:
1.75      thorpej   282:
1.223     perry     283: static inline int ipq_lock_try(void);
                    284: static inline void ipq_unlock(void);
1.75      thorpej   285:
1.223     perry     286: static inline int
1.211     perry     287: ipq_lock_try(void)
1.75      thorpej   288: {
                    289:        int s;
                    290:
1.132     thorpej   291:        /*
1.149     wiz       292:         * Use splvm() -- we're blocking things that would cause
1.132     thorpej   293:         * mbuf allocation.
                    294:         */
                    295:        s = splvm();
1.75      thorpej   296:        if (ipq_locked) {
                    297:                splx(s);
                    298:                return (0);
                    299:        }
                    300:        ipq_locked = 1;
                    301:        splx(s);
                    302:        return (1);
                    303: }
                    304:
1.223     perry     305: static inline void
1.211     perry     306: ipq_unlock(void)
1.75      thorpej   307: {
                    308:        int s;
                    309:
1.132     thorpej   310:        s = splvm();
1.75      thorpej   311:        ipq_locked = 0;
                    312:        splx(s);
                    313: }
                    314:
                    315: #ifdef DIAGNOSTIC
                    316: #define        IPQ_LOCK()                                                      \
                    317: do {                                                                   \
                    318:        if (ipq_lock_try() == 0) {                                      \
                    319:                printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
                    320:                panic("ipq_lock");                                      \
                    321:        }                                                               \
1.159     perry     322: } while (/*CONSTCOND*/ 0)
1.75      thorpej   323: #define        IPQ_LOCK_CHECK()                                                \
                    324: do {                                                                   \
                    325:        if (ipq_locked == 0) {                                          \
                    326:                printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
                    327:                panic("ipq lock check");                                \
                    328:        }                                                               \
1.159     perry     329: } while (/*CONSTCOND*/ 0)
1.75      thorpej   330: #else
                    331: #define        IPQ_LOCK()              (void) ipq_lock_try()
                    332: #define        IPQ_LOCK_CHECK()        /* nothing */
                    333: #endif
                    334:
                    335: #define        IPQ_UNLOCK()            ipq_unlock()
1.1       cgd       336:
1.200     simonb    337: POOL_INIT(inmulti_pool, sizeof(struct in_multi), 0, 0, 0, "inmltpl", NULL);
                    338: POOL_INIT(ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl", NULL);
1.72      thorpej   339:
1.135     thorpej   340: #ifdef INET_CSUM_COUNTERS
                    341: #include <sys/device.h>
                    342:
                    343: struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
                    344:     NULL, "inet", "hwcsum bad");
                    345: struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
                    346:     NULL, "inet", "hwcsum ok");
                    347: struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
                    348:     NULL, "inet", "swcsum");
                    349:
                    350: #define        INET_CSUM_COUNTER_INCR(ev)      (ev)->ev_count++
                    351:
1.201     matt      352: EVCNT_ATTACH_STATIC(ip_hwcsum_bad);
                    353: EVCNT_ATTACH_STATIC(ip_hwcsum_ok);
                    354: EVCNT_ATTACH_STATIC(ip_swcsum);
                    355:
1.135     thorpej   356: #else
                    357:
                    358: #define        INET_CSUM_COUNTER_INCR(ev)      /* nothing */
                    359:
                    360: #endif /* INET_CSUM_COUNTERS */
                    361:
1.1       cgd       362: /*
                    363:  * We need to save the IP options in case a protocol wants to respond
                    364:  * to an incoming packet over the same route if the packet got here
                    365:  * using IP source routing.  This allows connection establishment and
                    366:  * maintenance when the remote end is on a network that is not known
                    367:  * to us.
                    368:  */
                    369: int    ip_nhops = 0;
                    370: static struct ip_srcrt {
                    371:        struct  in_addr dst;                    /* final destination */
                    372:        char    nop;                            /* one NOP to align */
                    373:        char    srcopt[IPOPT_OFFSET + 1];       /* OPTVAL, OLEN and OFFSET */
                    374:        struct  in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
                    375: } ip_srcrt;
                    376:
1.210     perry     377: static void save_rte(u_char *, struct in_addr);
1.35      mycroft   378:
1.164     matt      379: #ifdef MBUFTRACE
                    380: struct mowner ip_rx_mowner = { "internet", "rx" };
                    381: struct mowner ip_tx_mowner = { "internet", "tx" };
                    382: #endif
                    383:
1.1       cgd       384: /*
1.194     jonathan  385:  * Compute IP limits derived from the value of nmbclusters.
                    386:  */
                    387: static void
                    388: ip_nmbclusters_changed(void)
                    389: {
                    390:        ip_maxfrags = nmbclusters / 4;
                    391:        ip_nmbclusters =  nmbclusters;
                    392: }
                    393:
                    394: /*
1.1       cgd       395:  * IP initialization: fill in IP protocol switch table.
                    396:  * All protocols not implemented in kernel go to raw IP protocol handler.
                    397:  */
1.8       mycroft   398: void
1.211     perry     399: ip_init(void)
1.1       cgd       400: {
1.199     matt      401:        const struct protosw *pr;
1.109     augustss  402:        int i;
1.1       cgd       403:
                    404:        pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
                    405:        if (pr == 0)
                    406:                panic("ip_init");
                    407:        for (i = 0; i < IPPROTO_MAX; i++)
                    408:                ip_protox[i] = pr - inetsw;
                    409:        for (pr = inetdomain.dom_protosw;
                    410:            pr < inetdomain.dom_protoswNPROTOSW; pr++)
                    411:                if (pr->pr_domain->dom_family == PF_INET &&
                    412:                    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
                    413:                        ip_protox[pr->pr_protocol] = pr - inetsw;
1.192     jonathan  414:
1.190     jonathan  415:        for (i = 0; i < IPREASS_NHASH; i++)
                    416:                LIST_INIT(&ipq[i]);
                    417:
1.224.2.2  yamt      418:        ip_id = time_second & 0xfffff;
1.194     jonathan  419:
1.1       cgd       420:        ipintrq.ifq_maxlen = ipqmaxlen;
1.194     jonathan  421:        ip_nmbclusters_changed();
                    422:
1.181     jonathan  423:        TAILQ_INIT(&in_ifaddrhead);
1.120     ad        424:        in_ifaddrhashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IFADDR,
                    425:            M_WAITOK, &in_ifaddrhash);
1.166     matt      426:        in_multihashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, M_IPMADDR,
                    427:            M_WAITOK, &in_multihash);
1.160     itojun    428:        ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
1.73      thorpej   429: #ifdef GATEWAY
                    430:        ipflow_init();
                    431: #endif
1.121     thorpej   432:
                    433: #ifdef PFIL_HOOKS
                    434:        /* Register our Packet Filter hook. */
1.126     thorpej   435:        inet_pfil_hook.ph_type = PFIL_TYPE_AF;
                    436:        inet_pfil_hook.ph_af   = AF_INET;
1.121     thorpej   437:        i = pfil_head_register(&inet_pfil_hook);
                    438:        if (i != 0)
                    439:                printf("ip_init: WARNING: unable to register pfil hook, "
                    440:                    "error %d\n", i);
                    441: #endif /* PFIL_HOOKS */
1.135     thorpej   442:
1.164     matt      443: #ifdef MBUFTRACE
                    444:        MOWNER_ATTACH(&ip_tx_mowner);
                    445:        MOWNER_ATTACH(&ip_rx_mowner);
                    446: #endif /* MBUFTRACE */
1.1       cgd       447: }
                    448:
1.224.2.4  yamt      449: struct sockaddr_in ipaddr = {
                    450:        .sin_len = sizeof(ipaddr),
                    451:        .sin_family = AF_INET,
                    452: };
1.1       cgd       453: struct route ipforward_rt;
                    454:
                    455: /*
1.89      itojun    456:  * IP software interrupt routine
                    457:  */
                    458: void
1.211     perry     459: ipintr(void)
1.89      itojun    460: {
                    461:        int s;
                    462:        struct mbuf *m;
                    463:
                    464:        while (1) {
1.132     thorpej   465:                s = splnet();
1.89      itojun    466:                IF_DEQUEUE(&ipintrq, m);
                    467:                splx(s);
                    468:                if (m == 0)
                    469:                        return;
1.164     matt      470:                MCLAIM(m, &ip_rx_mowner);
1.89      itojun    471:                ip_input(m);
                    472:        }
                    473: }
                    474:
                    475: /*
1.1       cgd       476:  * Ip input routine.  Checksum and byte swap header.  If fragmented
                    477:  * try to reassemble.  Process options.  Pass to next level.
                    478:  */
1.8       mycroft   479: void
1.89      itojun    480: ip_input(struct mbuf *m)
1.1       cgd       481: {
1.109     augustss  482:        struct ip *ip = NULL;
                    483:        struct ipq *fp;
                    484:        struct in_ifaddr *ia;
                    485:        struct ifaddr *ifa;
1.25      cgd       486:        struct ipqent *ipqe;
1.89      itojun    487:        int hlen = 0, mff, len;
1.100     itojun    488:        int downmatch;
1.165     christos  489:        int checkif;
1.169     itojun    490:        int srcrt = 0;
1.190     jonathan  491:        u_int hash;
1.173     jonathan  492: #ifdef FAST_IPSEC
                    493:        struct m_tag *mtag;
                    494:        struct tdb_ident *tdbi;
                    495:        struct secpolicy *sp;
                    496:        int s, error;
                    497: #endif /* FAST_IPSEC */
1.1       cgd       498:
1.164     matt      499:        MCLAIM(m, &ip_rx_mowner);
1.1       cgd       500: #ifdef DIAGNOSTIC
                    501:        if ((m->m_flags & M_PKTHDR) == 0)
                    502:                panic("ipintr no HDR");
1.89      itojun    503: #endif
1.164     matt      504:
1.1       cgd       505:        /*
                    506:         * If no IP addresses have been set yet but the interfaces
                    507:         * are receiving, can't do anything with incoming packets yet.
                    508:         */
1.181     jonathan  509:        if (TAILQ_FIRST(&in_ifaddrhead) == 0)
1.1       cgd       510:                goto bad;
                    511:        ipstat.ips_total++;
1.154     thorpej   512:        /*
                    513:         * If the IP header is not aligned, slurp it up into a new
                    514:         * mbuf with space for link headers, in the event we forward
                    515:         * it.  Otherwise, if it is aligned, make sure the entire
                    516:         * base IP header is in the first mbuf of the chain.
                    517:         */
                    518:        if (IP_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) {
                    519:                if ((m = m_copyup(m, sizeof(struct ip),
                    520:                                  (max_linkhdr + 3) & ~3)) == NULL) {
                    521:                        /* XXXJRT new stat, please */
                    522:                        ipstat.ips_toosmall++;
                    523:                        return;
                    524:                }
                    525:        } else if (__predict_false(m->m_len < sizeof (struct ip))) {
                    526:                if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
                    527:                        ipstat.ips_toosmall++;
                    528:                        return;
                    529:                }
1.1       cgd       530:        }
                    531:        ip = mtod(m, struct ip *);
1.13      mycroft   532:        if (ip->ip_v != IPVERSION) {
                    533:                ipstat.ips_badvers++;
                    534:                goto bad;
                    535:        }
1.1       cgd       536:        hlen = ip->ip_hl << 2;
                    537:        if (hlen < sizeof(struct ip)) { /* minimum header length */
                    538:                ipstat.ips_badhlen++;
                    539:                goto bad;
                    540:        }
                    541:        if (hlen > m->m_len) {
                    542:                if ((m = m_pullup(m, hlen)) == 0) {
                    543:                        ipstat.ips_badhlen++;
1.89      itojun    544:                        return;
1.1       cgd       545:                }
                    546:                ip = mtod(m, struct ip *);
                    547:        }
1.98      thorpej   548:
1.85      hwr       549:        /*
1.99      thorpej   550:         * RFC1122: packets with a multicast source address are
1.98      thorpej   551:         * not allowed.
1.85      hwr       552:         */
                    553:        if (IN_MULTICAST(ip->ip_src.s_addr)) {
1.130     itojun    554:                ipstat.ips_badaddr++;
1.85      hwr       555:                goto bad;
1.129     itojun    556:        }
                    557:
                    558:        /* 127/8 must not appear on wire - RFC1122 */
                    559:        if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
                    560:            (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
1.130     itojun    561:                if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
                    562:                        ipstat.ips_badaddr++;
1.129     itojun    563:                        goto bad;
1.130     itojun    564:                }
1.85      hwr       565:        }
                    566:
1.135     thorpej   567:        switch (m->m_pkthdr.csum_flags &
1.137     thorpej   568:                ((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
1.135     thorpej   569:                 M_CSUM_IPv4_BAD)) {
                    570:        case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
                    571:                INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
                    572:                goto badcsum;
                    573:
                    574:        case M_CSUM_IPv4:
                    575:                /* Checksum was okay. */
                    576:                INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
                    577:                break;
                    578:
                    579:        default:
1.206     thorpej   580:                /*
                    581:                 * Must compute it ourselves.  Maybe skip checksum on
                    582:                 * loopback interfaces.
                    583:                 */
                    584:                if (__predict_true(!(m->m_pkthdr.rcvif->if_flags &
                    585:                                     IFF_LOOPBACK) || ip_do_loopback_cksum)) {
                    586:                        INET_CSUM_COUNTER_INCR(&ip_swcsum);
                    587:                        if (in_cksum(m, hlen) != 0)
                    588:                                goto badcsum;
                    589:                }
1.135     thorpej   590:                break;
1.1       cgd       591:        }
                    592:
1.121     thorpej   593:        /* Retrieve the packet length. */
                    594:        len = ntohs(ip->ip_len);
1.81      proff     595:
                    596:        /*
                    597:         * Check for additional length bogosity
                    598:         */
1.84      proff     599:        if (len < hlen) {
1.81      proff     600:                ipstat.ips_badlen++;
                    601:                goto bad;
                    602:        }
1.1       cgd       603:
                    604:        /*
                    605:         * Check that the amount of data in the buffers
                    606:         * is as at least much as the IP header would have us expect.
                    607:         * Trim mbufs if longer than we expect.
                    608:         * Drop packet if shorter than we expect.
                    609:         */
1.35      mycroft   610:        if (m->m_pkthdr.len < len) {
1.1       cgd       611:                ipstat.ips_tooshort++;
                    612:                goto bad;
                    613:        }
1.35      mycroft   614:        if (m->m_pkthdr.len > len) {
1.1       cgd       615:                if (m->m_len == m->m_pkthdr.len) {
1.35      mycroft   616:                        m->m_len = len;
                    617:                        m->m_pkthdr.len = len;
1.1       cgd       618:                } else
1.35      mycroft   619:                        m_adj(m, len - m->m_pkthdr.len);
1.1       cgd       620:        }
                    621:
1.193     scw       622: #if defined(IPSEC)
1.149     wiz       623:        /* ipflow (IP fast forwarding) is not compatible with IPsec. */
1.94      itojun    624:        m->m_flags &= ~M_CANFASTFWD;
                    625: #else
1.64      thorpej   626:        /*
                    627:         * Assume that we can create a fast-forward IP flow entry
                    628:         * based on this packet.
                    629:         */
                    630:        m->m_flags |= M_CANFASTFWD;
1.94      itojun    631: #endif
1.64      thorpej   632:
1.36      mrg       633: #ifdef PFIL_HOOKS
1.33      mrg       634:        /*
1.64      thorpej   635:         * Run through list of hooks for input packets.  If there are any
                    636:         * filters which require that additional packets in the flow are
                    637:         * not fast-forwarded, they must clear the M_CANFASTFWD flag.
                    638:         * Note that filters must _never_ set this flag, as another filter
                    639:         * in the list may have previously cleared it.
1.33      mrg       640:         */
1.127     itojun    641:        /*
                    642:         * let ipfilter look at packet on the wire,
                    643:         * not the decapsulated packet.
                    644:         */
                    645: #ifdef IPSEC
1.136     itojun    646:        if (!ipsec_getnhist(m))
1.186     scw       647: #elif defined(FAST_IPSEC)
                    648:        if (!ipsec_indone(m))
1.127     itojun    649: #else
                    650:        if (1)
                    651: #endif
                    652:        {
1.169     itojun    653:                struct in_addr odst;
                    654:
                    655:                odst = ip->ip_dst;
1.127     itojun    656:                if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
1.168     itojun    657:                    PFIL_IN) != 0)
                    658:                        return;
1.127     itojun    659:                if (m == NULL)
                    660:                        return;
                    661:                ip = mtod(m, struct ip *);
1.142     darrenr   662:                hlen = ip->ip_hl << 2;
1.205     darrenr   663:                /*
                    664:                 * XXX The setting of "srcrt" here is to prevent ip_forward()
                    665:                 * from generating ICMP redirects for packets that have
                    666:                 * been redirected by a hook back out on to the same LAN that
                    667:                 * they came from and is not an indication that the packet
                    668:                 * is being inffluenced by source routing options.  This
                    669:                 * allows things like
                    670:                 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp"
                    671:                 * where tlp0 is both on the 1.1.1.0/24 network and is the
                    672:                 * default route for hosts on 1.1.1.0/24.  Of course this
                    673:                 * also requires a "map tlp0 ..." to complete the story.
                    674:                 * One might argue whether or not this kind of network config.
1.212     perry     675:                 * should be supported in this manner...
1.205     darrenr   676:                 */
1.169     itojun    677:                srcrt = (odst.s_addr != ip->ip_dst.s_addr);
1.127     itojun    678:        }
1.36      mrg       679: #endif /* PFIL_HOOKS */
1.123     thorpej   680:
                    681: #ifdef ALTQ
                    682:        /* XXX Temporary until ALTQ is changed to use a pfil hook */
                    683:        if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
                    684:                /* packet dropped by traffic conditioner */
                    685:                return;
                    686:        }
                    687: #endif
1.121     thorpej   688:
                    689:        /*
1.1       cgd       690:         * Process options and, if not destined for us,
                    691:         * ship it on.  ip_dooptions returns 1 when an
                    692:         * error was detected (causing an icmp message
                    693:         * to be sent and the original packet to be freed).
                    694:         */
                    695:        ip_nhops = 0;           /* for source routed packets */
                    696:        if (hlen > sizeof (struct ip) && ip_dooptions(m))
1.89      itojun    697:                return;
1.1       cgd       698:
                    699:        /*
1.165     christos  700:         * Enable a consistency check between the destination address
                    701:         * and the arrival interface for a unicast packet (the RFC 1122
                    702:         * strong ES model) if IP forwarding is disabled and the packet
                    703:         * is not locally generated.
                    704:         *
                    705:         * XXX - Checking also should be disabled if the destination
                    706:         * address is ipnat'ed to a different interface.
                    707:         *
                    708:         * XXX - Checking is incompatible with IP aliases added
                    709:         * to the loopback interface instead of the interface where
                    710:         * the packets are received.
                    711:         *
                    712:         * XXX - We need to add a per ifaddr flag for this so that
                    713:         * we get finer grain control.
                    714:         */
                    715:        checkif = ip_checkinterface && (ipforwarding == 0) &&
                    716:            (m->m_pkthdr.rcvif != NULL) &&
                    717:            ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0);
                    718:
                    719:        /*
1.1       cgd       720:         * Check our list of addresses, to see if the packet is for us.
1.100     itojun    721:         *
                    722:         * Traditional 4.4BSD did not consult IFF_UP at all.
                    723:         * The behavior here is to treat addresses on !IFF_UP interface
                    724:         * as not mine.
1.1       cgd       725:         */
1.100     itojun    726:        downmatch = 0;
1.140     matt      727:        LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
1.97      itojun    728:                if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
1.165     christos  729:                        if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif)
                    730:                                continue;
1.97      itojun    731:                        if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
                    732:                                break;
1.100     itojun    733:                        else
                    734:                                downmatch++;
1.97      itojun    735:                }
                    736:        }
1.86      thorpej   737:        if (ia != NULL)
                    738:                goto ours;
1.224.2.1  yamt      739:        if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
1.209     matt      740:                IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) {
1.140     matt      741:                        if (ifa->ifa_addr->sa_family != AF_INET)
                    742:                                continue;
1.57      tls       743:                        ia = ifatoia(ifa);
1.35      mycroft   744:                        if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
                    745:                            in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
1.20      mycroft   746:                            /*
                    747:                             * Look for all-0's host part (old broadcast addr),
                    748:                             * either for subnet or net.
                    749:                             */
                    750:                            ip->ip_dst.s_addr == ia->ia_subnet ||
1.18      mycroft   751:                            ip->ip_dst.s_addr == ia->ia_net)
1.1       cgd       752:                                goto ours;
1.57      tls       753:                        /*
                    754:                         * An interface with IP address zero accepts
                    755:                         * all packets that arrive on that interface.
                    756:                         */
                    757:                        if (in_nullhost(ia->ia_addr.sin_addr))
                    758:                                goto ours;
1.1       cgd       759:                }
                    760:        }
1.18      mycroft   761:        if (IN_MULTICAST(ip->ip_dst.s_addr)) {
1.4       hpeyerl   762:                struct in_multi *inm;
                    763: #ifdef MROUTING
                    764:                extern struct socket *ip_mrouter;
1.10      brezak    765:
1.4       hpeyerl   766:                if (ip_mrouter) {
                    767:                        /*
                    768:                         * If we are acting as a multicast router, all
                    769:                         * incoming multicast packets are passed to the
                    770:                         * kernel-level multicast forwarding function.
                    771:                         * The packet is returned (relatively) intact; if
                    772:                         * ip_mforward() returns a non-zero value, the packet
                    773:                         * must be discarded, else it may be accepted below.
                    774:                         *
                    775:                         * (The IP ident field is put in the same byte order
                    776:                         * as expected when ip_mforward() is called from
                    777:                         * ip_output().)
                    778:                         */
1.13      mycroft   779:                        if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
                    780:                                ipstat.ips_cantforward++;
1.4       hpeyerl   781:                                m_freem(m);
1.89      itojun    782:                                return;
1.4       hpeyerl   783:                        }
                    784:
                    785:                        /*
                    786:                         * The process-level routing demon needs to receive
                    787:                         * all multicast IGMP packets, whether or not this
                    788:                         * host belongs to their destination groups.
                    789:                         */
                    790:                        if (ip->ip_p == IPPROTO_IGMP)
                    791:                                goto ours;
1.13      mycroft   792:                        ipstat.ips_forward++;
1.4       hpeyerl   793:                }
                    794: #endif
                    795:                /*
                    796:                 * See if we belong to the destination multicast group on the
                    797:                 * arrival interface.
                    798:                 */
                    799:                IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
                    800:                if (inm == NULL) {
1.13      mycroft   801:                        ipstat.ips_cantforward++;
1.4       hpeyerl   802:                        m_freem(m);
1.89      itojun    803:                        return;
1.4       hpeyerl   804:                }
                    805:                goto ours;
                    806:        }
1.19      mycroft   807:        if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
1.35      mycroft   808:            in_nullhost(ip->ip_dst))
1.1       cgd       809:                goto ours;
                    810:
                    811:        /*
                    812:         * Not for us; forward if possible and desirable.
                    813:         */
                    814:        if (ipforwarding == 0) {
                    815:                ipstat.ips_cantforward++;
                    816:                m_freem(m);
1.100     itojun    817:        } else {
                    818:                /*
                    819:                 * If ip_dst matched any of my address on !IFF_UP interface,
                    820:                 * and there's no IFF_UP interface that matches ip_dst,
                    821:                 * send icmp unreach.  Forwarding it will result in in-kernel
                    822:                 * forwarding loop till TTL goes to 0.
                    823:                 */
                    824:                if (downmatch) {
                    825:                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
                    826:                        ipstat.ips_cantforward++;
                    827:                        return;
                    828:                }
1.145     itojun    829: #ifdef IPSEC
                    830:                if (ipsec4_in_reject(m, NULL)) {
                    831:                        ipsecstat.in_polvio++;
                    832:                        goto bad;
                    833:                }
                    834: #endif
1.173     jonathan  835: #ifdef FAST_IPSEC
                    836:                mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
                    837:                s = splsoftnet();
                    838:                if (mtag != NULL) {
                    839:                        tdbi = (struct tdb_ident *)(mtag + 1);
                    840:                        sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
                    841:                } else {
                    842:                        sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
1.212     perry     843:                                                   IP_FORWARDING, &error);
1.173     jonathan  844:                }
                    845:                if (sp == NULL) {       /* NB: can happen if error */
                    846:                        splx(s);
                    847:                        /*XXX error stat???*/
                    848:                        DPRINTF(("ip_input: no SP for forwarding\n"));  /*XXX*/
                    849:                        goto bad;
                    850:                }
                    851:
                    852:                /*
                    853:                 * Check security policy against packet attributes.
                    854:                 */
                    855:                error = ipsec_in_reject(sp, m);
                    856:                KEY_FREESP(&sp);
                    857:                splx(s);
                    858:                if (error) {
                    859:                        ipstat.ips_cantforward++;
                    860:                        goto bad;
1.193     scw       861:                }
                    862:
                    863:                /*
                    864:                 * Peek at the outbound SP for this packet to determine if
                    865:                 * it's a Fast Forward candidate.
                    866:                 */
                    867:                mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
                    868:                if (mtag != NULL)
                    869:                        m->m_flags &= ~M_CANFASTFWD;
                    870:                else {
                    871:                        s = splsoftnet();
                    872:                        sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND,
                    873:                            (IP_FORWARDING |
                    874:                             (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
                    875:                            &error, NULL);
                    876:                        if (sp != NULL) {
                    877:                                m->m_flags &= ~M_CANFASTFWD;
                    878:                                KEY_FREESP(&sp);
                    879:                        }
                    880:                        splx(s);
1.173     jonathan  881:                }
                    882: #endif /* FAST_IPSEC */
1.145     itojun    883:
1.169     itojun    884:                ip_forward(m, srcrt);
1.100     itojun    885:        }
1.89      itojun    886:        return;
1.1       cgd       887:
                    888: ours:
                    889:        /*
                    890:         * If offset or IP_MF are set, must reassemble.
                    891:         * Otherwise, nothing need be done.
                    892:         * (We could look in the reassembly queue to see
                    893:         * if the packet was previously fragmented,
                    894:         * but it's not worth the time; just let them time out.)
                    895:         */
1.155     itojun    896:        if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
                    897:
1.1       cgd       898:                /*
                    899:                 * Look for queue of fragments
                    900:                 * of this datagram.
                    901:                 */
1.75      thorpej   902:                IPQ_LOCK();
1.190     jonathan  903:                hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
                    904:                /* XXX LIST_FOREACH(fp, &ipq[hash], ipq_q) */
                    905:                for (fp = LIST_FIRST(&ipq[hash]); fp != NULL;
                    906:                     fp = LIST_NEXT(fp, ipq_q)) {
1.1       cgd       907:                        if (ip->ip_id == fp->ipq_id &&
1.35      mycroft   908:                            in_hosteq(ip->ip_src, fp->ipq_src) &&
                    909:                            in_hosteq(ip->ip_dst, fp->ipq_dst) &&
1.1       cgd       910:                            ip->ip_p == fp->ipq_p)
                    911:                                goto found;
1.190     jonathan  912:
                    913:                }
1.1       cgd       914:                fp = 0;
                    915: found:
                    916:
                    917:                /*
                    918:                 * Adjust ip_len to not reflect header,
1.25      cgd       919:                 * set ipqe_mff if more fragments are expected,
1.1       cgd       920:                 * convert offset of this to bytes.
                    921:                 */
1.155     itojun    922:                ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
                    923:                mff = (ip->ip_off & htons(IP_MF)) != 0;
1.25      cgd       924:                if (mff) {
1.16      cgd       925:                        /*
                    926:                         * Make sure that fragments have a data length
                    927:                         * that's a non-zero multiple of 8 bytes.
                    928:                         */
1.155     itojun    929:                        if (ntohs(ip->ip_len) == 0 ||
                    930:                            (ntohs(ip->ip_len) & 0x7) != 0) {
1.16      cgd       931:                                ipstat.ips_badfrags++;
1.75      thorpej   932:                                IPQ_UNLOCK();
1.16      cgd       933:                                goto bad;
                    934:                        }
                    935:                }
1.155     itojun    936:                ip->ip_off = htons((ntohs(ip->ip_off) & IP_OFFMASK) << 3);
1.1       cgd       937:
                    938:                /*
                    939:                 * If datagram marked as having more fragments
                    940:                 * or if this is not the first fragment,
                    941:                 * attempt reassembly; if it succeeds, proceed.
                    942:                 */
1.155     itojun    943:                if (mff || ip->ip_off != htons(0)) {
1.1       cgd       944:                        ipstat.ips_fragments++;
1.72      thorpej   945:                        ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
1.25      cgd       946:                        if (ipqe == NULL) {
                    947:                                ipstat.ips_rcvmemdrop++;
1.75      thorpej   948:                                IPQ_UNLOCK();
1.25      cgd       949:                                goto bad;
                    950:                        }
                    951:                        ipqe->ipqe_mff = mff;
1.50      thorpej   952:                        ipqe->ipqe_m = m;
1.25      cgd       953:                        ipqe->ipqe_ip = ip;
1.190     jonathan  954:                        m = ip_reass(ipqe, fp, &ipq[hash]);
1.75      thorpej   955:                        if (m == 0) {
                    956:                                IPQ_UNLOCK();
1.89      itojun    957:                                return;
1.75      thorpej   958:                        }
1.13      mycroft   959:                        ipstat.ips_reassembled++;
1.50      thorpej   960:                        ip = mtod(m, struct ip *);
1.74      thorpej   961:                        hlen = ip->ip_hl << 2;
1.155     itojun    962:                        ip->ip_len = htons(ntohs(ip->ip_len) + hlen);
1.1       cgd       963:                } else
                    964:                        if (fp)
                    965:                                ip_freef(fp);
1.75      thorpej   966:                IPQ_UNLOCK();
1.79      mycroft   967:        }
1.128     itojun    968:
1.173     jonathan  969: #if defined(IPSEC)
1.128     itojun    970:        /*
                    971:         * enforce IPsec policy checking if we are seeing last header.
                    972:         * note that we do not visit this with protocols with pcb layer
                    973:         * code - like udp/tcp/raw ip.
                    974:         */
                    975:        if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
                    976:            ipsec4_in_reject(m, NULL)) {
                    977:                ipsecstat.in_polvio++;
                    978:                goto bad;
                    979:        }
                    980: #endif
1.224.2.1  yamt      981: #ifdef FAST_IPSEC
1.173     jonathan  982:        /*
                    983:         * enforce IPsec policy checking if we are seeing last header.
                    984:         * note that we do not visit this with protocols with pcb layer
                    985:         * code - like udp/tcp/raw ip.
                    986:         */
                    987:        if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
                    988:                /*
                    989:                 * Check if the packet has already had IPsec processing
                    990:                 * done.  If so, then just pass it along.  This tag gets
                    991:                 * set during AH, ESP, etc. input handling, before the
                    992:                 * packet is returned to the ip input queue for delivery.
1.212     perry     993:                 */
1.173     jonathan  994:                mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
                    995:                s = splsoftnet();
                    996:                if (mtag != NULL) {
                    997:                        tdbi = (struct tdb_ident *)(mtag + 1);
                    998:                        sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
                    999:                } else {
                   1000:                        sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
1.212     perry    1001:                                                   IP_FORWARDING, &error);
1.173     jonathan 1002:                }
                   1003:                if (sp != NULL) {
                   1004:                        /*
                   1005:                         * Check security policy against packet attributes.
                   1006:                         */
                   1007:                        error = ipsec_in_reject(sp, m);
                   1008:                        KEY_FREESP(&sp);
                   1009:                } else {
                   1010:                        /* XXX error stat??? */
                   1011:                        error = EINVAL;
                   1012: DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
                   1013:                        goto bad;
                   1014:                }
                   1015:                splx(s);
                   1016:                if (error)
                   1017:                        goto bad;
                   1018:        }
                   1019: #endif /* FAST_IPSEC */
1.1       cgd      1020:
                   1021:        /*
                   1022:         * Switch out to protocol's input routine.
                   1023:         */
1.82      aidan    1024: #if IFA_STATS
1.122     itojun   1025:        if (ia && ip)
1.155     itojun   1026:                ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
1.82      aidan    1027: #endif
1.1       cgd      1028:        ipstat.ips_delivered++;
1.89      itojun   1029:     {
                   1030:        int off = hlen, nh = ip->ip_p;
                   1031:
                   1032:        (*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
                   1033:        return;
                   1034:     }
1.1       cgd      1035: bad:
                   1036:        m_freem(m);
1.135     thorpej  1037:        return;
                   1038:
                   1039: badcsum:
                   1040:        ipstat.ips_badsum++;
                   1041:        m_freem(m);
1.1       cgd      1042: }
                   1043:
                   1044: /*
                   1045:  * Take incoming datagram fragment and try to
                   1046:  * reassemble it into whole datagram.  If a chain for
                   1047:  * reassembly of this datagram already exists, then it
                   1048:  * is given as fp; otherwise have to make a chain.
                   1049:  */
1.50      thorpej  1050: struct mbuf *
1.211     perry    1051: ip_reass(struct ipqent *ipqe, struct ipq *fp, struct ipqhead *ipqhead)
1.1       cgd      1052: {
1.109     augustss 1053:        struct mbuf *m = ipqe->ipqe_m;
                   1054:        struct ipqent *nq, *p, *q;
1.25      cgd      1055:        struct ip *ip;
1.1       cgd      1056:        struct mbuf *t;
1.25      cgd      1057:        int hlen = ipqe->ipqe_ip->ip_hl << 2;
1.1       cgd      1058:        int i, next;
                   1059:
1.75      thorpej  1060:        IPQ_LOCK_CHECK();
                   1061:
1.1       cgd      1062:        /*
                   1063:         * Presence of header sizes in mbufs
                   1064:         * would confuse code below.
                   1065:         */
                   1066:        m->m_data += hlen;
                   1067:        m->m_len -= hlen;
                   1068:
1.194     jonathan 1069: #ifdef notyet
                   1070:        /* make sure fragment limit is up-to-date */
                   1071:        CHECK_NMBCLUSTER_PARAMS();
                   1072:
                   1073:        /* If we have too many fragments, drop the older half. */
                   1074:        if (ip_nfrags >= ip_maxfrags)
                   1075:                ip_reass_drophalf(void);
                   1076: #endif
                   1077:
1.1       cgd      1078:        /*
1.192     jonathan 1079:         * We are about to add a fragment; increment frag count.
                   1080:         */
                   1081:        ip_nfrags++;
1.212     perry    1082:
1.192     jonathan 1083:        /*
1.1       cgd      1084:         * If first fragment to arrive, create a reassembly queue.
                   1085:         */
                   1086:        if (fp == 0) {
1.131     itojun   1087:                /*
                   1088:                 * Enforce upper bound on number of fragmented packets
                   1089:                 * for which we attempt reassembly;
                   1090:                 * If maxfrag is 0, never accept fragments.
                   1091:                 * If maxfrag is -1, accept all fragments without limitation.
                   1092:                 */
                   1093:                if (ip_maxfragpackets < 0)
                   1094:                        ;
                   1095:                else if (ip_nfragpackets >= ip_maxfragpackets)
                   1096:                        goto dropfrag;
                   1097:                ip_nfragpackets++;
1.50      thorpej  1098:                MALLOC(fp, struct ipq *, sizeof (struct ipq),
                   1099:                    M_FTABLE, M_NOWAIT);
                   1100:                if (fp == NULL)
1.1       cgd      1101:                        goto dropfrag;
1.190     jonathan 1102:                LIST_INSERT_HEAD(ipqhead, fp, ipq_q);
1.192     jonathan 1103:                fp->ipq_nfrags = 1;
1.1       cgd      1104:                fp->ipq_ttl = IPFRAGTTL;
1.25      cgd      1105:                fp->ipq_p = ipqe->ipqe_ip->ip_p;
                   1106:                fp->ipq_id = ipqe->ipqe_ip->ip_id;
1.148     matt     1107:                TAILQ_INIT(&fp->ipq_fragq);
1.25      cgd      1108:                fp->ipq_src = ipqe->ipqe_ip->ip_src;
                   1109:                fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
                   1110:                p = NULL;
1.1       cgd      1111:                goto insert;
1.192     jonathan 1112:        } else {
                   1113:                fp->ipq_nfrags++;
1.1       cgd      1114:        }
                   1115:
                   1116:        /*
                   1117:         * Find a segment which begins after this one does.
                   1118:         */
1.148     matt     1119:        for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
                   1120:            p = q, q = TAILQ_NEXT(q, ipqe_q))
1.155     itojun   1121:                if (ntohs(q->ipqe_ip->ip_off) > ntohs(ipqe->ipqe_ip->ip_off))
1.1       cgd      1122:                        break;
                   1123:
                   1124:        /*
                   1125:         * If there is a preceding segment, it may provide some of
                   1126:         * our data already.  If so, drop the data from the incoming
                   1127:         * segment.  If it provides all of our data, drop us.
                   1128:         */
1.25      cgd      1129:        if (p != NULL) {
1.155     itojun   1130:                i = ntohs(p->ipqe_ip->ip_off) + ntohs(p->ipqe_ip->ip_len) -
                   1131:                    ntohs(ipqe->ipqe_ip->ip_off);
1.1       cgd      1132:                if (i > 0) {
1.155     itojun   1133:                        if (i >= ntohs(ipqe->ipqe_ip->ip_len))
1.1       cgd      1134:                                goto dropfrag;
1.50      thorpej  1135:                        m_adj(ipqe->ipqe_m, i);
1.155     itojun   1136:                        ipqe->ipqe_ip->ip_off =
                   1137:                            htons(ntohs(ipqe->ipqe_ip->ip_off) + i);
                   1138:                        ipqe->ipqe_ip->ip_len =
                   1139:                            htons(ntohs(ipqe->ipqe_ip->ip_len) - i);
1.1       cgd      1140:                }
                   1141:        }
                   1142:
                   1143:        /*
                   1144:         * While we overlap succeeding segments trim them or,
                   1145:         * if they are completely covered, dequeue them.
                   1146:         */
1.155     itojun   1147:        for (; q != NULL &&
                   1148:            ntohs(ipqe->ipqe_ip->ip_off) + ntohs(ipqe->ipqe_ip->ip_len) >
                   1149:            ntohs(q->ipqe_ip->ip_off); q = nq) {
                   1150:                i = (ntohs(ipqe->ipqe_ip->ip_off) +
                   1151:                    ntohs(ipqe->ipqe_ip->ip_len)) - ntohs(q->ipqe_ip->ip_off);
                   1152:                if (i < ntohs(q->ipqe_ip->ip_len)) {
                   1153:                        q->ipqe_ip->ip_len =
                   1154:                            htons(ntohs(q->ipqe_ip->ip_len) - i);
                   1155:                        q->ipqe_ip->ip_off =
                   1156:                            htons(ntohs(q->ipqe_ip->ip_off) + i);
1.50      thorpej  1157:                        m_adj(q->ipqe_m, i);
1.1       cgd      1158:                        break;
                   1159:                }
1.148     matt     1160:                nq = TAILQ_NEXT(q, ipqe_q);
1.50      thorpej  1161:                m_freem(q->ipqe_m);
1.148     matt     1162:                TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72      thorpej  1163:                pool_put(&ipqent_pool, q);
1.192     jonathan 1164:                fp->ipq_nfrags--;
                   1165:                ip_nfrags--;
1.1       cgd      1166:        }
                   1167:
                   1168: insert:
                   1169:        /*
                   1170:         * Stick new segment in its place;
                   1171:         * check for complete reassembly.
                   1172:         */
1.25      cgd      1173:        if (p == NULL) {
1.148     matt     1174:                TAILQ_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
1.25      cgd      1175:        } else {
1.148     matt     1176:                TAILQ_INSERT_AFTER(&fp->ipq_fragq, p, ipqe, ipqe_q);
1.25      cgd      1177:        }
1.1       cgd      1178:        next = 0;
1.148     matt     1179:        for (p = NULL, q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL;
                   1180:            p = q, q = TAILQ_NEXT(q, ipqe_q)) {
1.155     itojun   1181:                if (ntohs(q->ipqe_ip->ip_off) != next)
1.1       cgd      1182:                        return (0);
1.155     itojun   1183:                next += ntohs(q->ipqe_ip->ip_len);
1.1       cgd      1184:        }
1.25      cgd      1185:        if (p->ipqe_mff)
1.1       cgd      1186:                return (0);
                   1187:
                   1188:        /*
1.41      thorpej  1189:         * Reassembly is complete.  Check for a bogus message size and
                   1190:         * concatenate fragments.
1.1       cgd      1191:         */
1.148     matt     1192:        q = TAILQ_FIRST(&fp->ipq_fragq);
1.25      cgd      1193:        ip = q->ipqe_ip;
1.41      thorpej  1194:        if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
                   1195:                ipstat.ips_toolong++;
                   1196:                ip_freef(fp);
                   1197:                return (0);
                   1198:        }
1.50      thorpej  1199:        m = q->ipqe_m;
1.1       cgd      1200:        t = m->m_next;
                   1201:        m->m_next = 0;
                   1202:        m_cat(m, t);
1.148     matt     1203:        nq = TAILQ_NEXT(q, ipqe_q);
1.72      thorpej  1204:        pool_put(&ipqent_pool, q);
1.25      cgd      1205:        for (q = nq; q != NULL; q = nq) {
1.50      thorpej  1206:                t = q->ipqe_m;
1.148     matt     1207:                nq = TAILQ_NEXT(q, ipqe_q);
1.72      thorpej  1208:                pool_put(&ipqent_pool, q);
1.1       cgd      1209:                m_cat(m, t);
                   1210:        }
1.192     jonathan 1211:        ip_nfrags -= fp->ipq_nfrags;
1.1       cgd      1212:
                   1213:        /*
                   1214:         * Create header for new ip packet by
                   1215:         * modifying header of first packet;
                   1216:         * dequeue and discard fragment reassembly header.
                   1217:         * Make header visible.
                   1218:         */
1.155     itojun   1219:        ip->ip_len = htons(next);
1.25      cgd      1220:        ip->ip_src = fp->ipq_src;
                   1221:        ip->ip_dst = fp->ipq_dst;
                   1222:        LIST_REMOVE(fp, ipq_q);
1.50      thorpej  1223:        FREE(fp, M_FTABLE);
1.131     itojun   1224:        ip_nfragpackets--;
1.1       cgd      1225:        m->m_len += (ip->ip_hl << 2);
                   1226:        m->m_data -= (ip->ip_hl << 2);
                   1227:        /* some debugging cruft by sklower, below, will go away soon */
                   1228:        if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1.109     augustss 1229:                int plen = 0;
1.50      thorpej  1230:                for (t = m; t; t = t->m_next)
                   1231:                        plen += t->m_len;
                   1232:                m->m_pkthdr.len = plen;
1.213     yamt     1233:                m->m_pkthdr.csum_flags = 0;
1.1       cgd      1234:        }
1.50      thorpej  1235:        return (m);
1.1       cgd      1236:
                   1237: dropfrag:
1.192     jonathan 1238:        if (fp != 0)
                   1239:                fp->ipq_nfrags--;
                   1240:        ip_nfrags--;
1.1       cgd      1241:        ipstat.ips_fragdropped++;
                   1242:        m_freem(m);
1.72      thorpej  1243:        pool_put(&ipqent_pool, ipqe);
1.1       cgd      1244:        return (0);
                   1245: }
                   1246:
                   1247: /*
                   1248:  * Free a fragment reassembly header and all
                   1249:  * associated datagrams.
                   1250:  */
1.8       mycroft  1251: void
1.211     perry    1252: ip_freef(struct ipq *fp)
1.1       cgd      1253: {
1.109     augustss 1254:        struct ipqent *q, *p;
1.192     jonathan 1255:        u_int nfrags = 0;
1.1       cgd      1256:
1.75      thorpej  1257:        IPQ_LOCK_CHECK();
                   1258:
1.148     matt     1259:        for (q = TAILQ_FIRST(&fp->ipq_fragq); q != NULL; q = p) {
                   1260:                p = TAILQ_NEXT(q, ipqe_q);
1.50      thorpej  1261:                m_freem(q->ipqe_m);
1.192     jonathan 1262:                nfrags++;
1.148     matt     1263:                TAILQ_REMOVE(&fp->ipq_fragq, q, ipqe_q);
1.72      thorpej  1264:                pool_put(&ipqent_pool, q);
1.1       cgd      1265:        }
1.192     jonathan 1266:
                   1267:        if (nfrags != fp->ipq_nfrags)
                   1268:            printf("ip_freef: nfrags %d != %d\n", fp->ipq_nfrags, nfrags);
                   1269:        ip_nfrags -= nfrags;
1.25      cgd      1270:        LIST_REMOVE(fp, ipq_q);
1.50      thorpej  1271:        FREE(fp, M_FTABLE);
1.131     itojun   1272:        ip_nfragpackets--;
1.1       cgd      1273: }
                   1274:
                   1275: /*
1.194     jonathan 1276:  * IP reassembly TTL machinery for  multiplicative drop.
                   1277:  */
                   1278: static u_int   fragttl_histo[(IPFRAGTTL+1)];
                   1279:
                   1280:
                   1281: /*
                   1282:  * Decrement TTL of all reasembly queue entries by `ticks'.
                   1283:  * Count number of distinct fragments (as opposed to partial, fragmented
                   1284:  * datagrams) in the reassembly queue.  While we  traverse the entire
                   1285:  * reassembly queue, compute and return the median TTL over all fragments.
                   1286:  */
                   1287: static u_int
                   1288: ip_reass_ttl_decr(u_int ticks)
                   1289: {
1.198     matt     1290:        u_int nfrags, median, dropfraction, keepfraction;
1.194     jonathan 1291:        struct ipq *fp, *nfp;
1.198     matt     1292:        int i;
1.212     perry    1293:
1.194     jonathan 1294:        nfrags = 0;
                   1295:        memset(fragttl_histo, 0, sizeof fragttl_histo);
1.212     perry    1296:
1.194     jonathan 1297:        for (i = 0; i < IPREASS_NHASH; i++) {
                   1298:                for (fp = LIST_FIRST(&ipq[i]); fp != NULL; fp = nfp) {
                   1299:                        fp->ipq_ttl = ((fp->ipq_ttl  <= ticks) ?
                   1300:                                       0 : fp->ipq_ttl - ticks);
                   1301:                        nfp = LIST_NEXT(fp, ipq_q);
                   1302:                        if (fp->ipq_ttl == 0) {
                   1303:                                ipstat.ips_fragtimeout++;
                   1304:                                ip_freef(fp);
                   1305:                        } else {
                   1306:                                nfrags += fp->ipq_nfrags;
                   1307:                                fragttl_histo[fp->ipq_ttl] += fp->ipq_nfrags;
                   1308:                        }
                   1309:                }
                   1310:        }
                   1311:
                   1312:        KASSERT(ip_nfrags == nfrags);
                   1313:
                   1314:        /* Find median (or other drop fraction) in histogram. */
                   1315:        dropfraction = (ip_nfrags / 2);
                   1316:        keepfraction = ip_nfrags - dropfraction;
                   1317:        for (i = IPFRAGTTL, median = 0; i >= 0; i--) {
                   1318:                median +=  fragttl_histo[i];
                   1319:                if (median >= keepfraction)
                   1320:                        break;
                   1321:        }
                   1322:
                   1323:        /* Return TTL of median (or other fraction). */
                   1324:        return (u_int)i;
                   1325: }
                   1326:
                   1327: void
                   1328: ip_reass_drophalf(void)
                   1329: {
                   1330:
                   1331:        u_int median_ticks;
                   1332:        /*
                   1333:         * Compute median TTL of all fragments, and count frags
                   1334:         * with that TTL or lower (roughly half of all fragments).
                   1335:         */
                   1336:        median_ticks = ip_reass_ttl_decr(0);
                   1337:
                   1338:        /* Drop half. */
                   1339:        median_ticks = ip_reass_ttl_decr(median_ticks);
                   1340:
                   1341: }
                   1342:
                   1343: /*
1.1       cgd      1344:  * IP timer processing;
                   1345:  * if a timer expires on a reassembly
                   1346:  * queue, discard it.
                   1347:  */
1.8       mycroft  1348: void
1.211     perry    1349: ip_slowtimo(void)
1.1       cgd      1350: {
1.191     jonathan 1351:        static u_int dropscanidx = 0;
                   1352:        u_int i;
1.194     jonathan 1353:        u_int median_ttl;
1.24      mycroft  1354:        int s = splsoftnet();
1.1       cgd      1355:
1.75      thorpej  1356:        IPQ_LOCK();
1.194     jonathan 1357:
                   1358:        /* Age TTL of all fragments by 1 tick .*/
                   1359:        median_ttl = ip_reass_ttl_decr(1);
                   1360:
                   1361:        /* make sure fragment limit is up-to-date */
                   1362:        CHECK_NMBCLUSTER_PARAMS();
                   1363:
                   1364:        /* If we have too many fragments, drop the older half. */
                   1365:        if (ip_nfrags > ip_maxfrags)
                   1366:                ip_reass_ttl_decr(median_ttl);
                   1367:
1.131     itojun   1368:        /*
1.194     jonathan 1369:         * If we are over the maximum number of fragmented packets
1.131     itojun   1370:         * (due to the limit being lowered), drain off
1.190     jonathan 1371:         * enough to get down to the new limit. Start draining
                   1372:         * from the reassembly hashqueue most recently drained.
1.131     itojun   1373:         */
                   1374:        if (ip_maxfragpackets < 0)
                   1375:                ;
                   1376:        else {
1.190     jonathan 1377:                int wrapped = 0;
                   1378:
                   1379:                i = dropscanidx;
                   1380:                while (ip_nfragpackets > ip_maxfragpackets && wrapped == 0) {
                   1381:                        while (LIST_FIRST(&ipq[i]) != NULL)
                   1382:                                ip_freef(LIST_FIRST(&ipq[i]));
                   1383:                        if (++i >= IPREASS_NHASH) {
                   1384:                                i = 0;
                   1385:                        }
                   1386:                        /*
                   1387:                         * Dont scan forever even if fragment counters are
                   1388:                         * wrong: stop after scanning entire reassembly queue.
                   1389:                         */
                   1390:                        if (i == dropscanidx)
                   1391:                            wrapped = 1;
                   1392:                }
                   1393:                dropscanidx = i;
1.131     itojun   1394:        }
1.75      thorpej  1395:        IPQ_UNLOCK();
1.63      matt     1396: #ifdef GATEWAY
                   1397:        ipflow_slowtimo();
                   1398: #endif
1.1       cgd      1399:        splx(s);
                   1400: }
                   1401:
                   1402: /*
                   1403:  * Drain off all datagram fragments.
                   1404:  */
1.8       mycroft  1405: void
1.211     perry    1406: ip_drain(void)
1.1       cgd      1407: {
                   1408:
1.75      thorpej  1409:        /*
                   1410:         * We may be called from a device's interrupt context.  If
                   1411:         * the ipq is already busy, just bail out now.
                   1412:         */
                   1413:        if (ipq_lock_try() == 0)
                   1414:                return;
                   1415:
1.194     jonathan 1416:        /*
                   1417:         * Drop half the total fragments now. If more mbufs are needed,
                   1418:         *  we will be called again soon.
                   1419:         */
                   1420:        ip_reass_drophalf();
1.75      thorpej  1421:
                   1422:        IPQ_UNLOCK();
1.1       cgd      1423: }
                   1424:
                   1425: /*
                   1426:  * Do option processing on a datagram,
                   1427:  * possibly discarding it if bad options are encountered,
                   1428:  * or forwarding it if source-routed.
                   1429:  * Returns 1 if packet has been forwarded/freed,
                   1430:  * 0 if the packet should be processed further.
                   1431:  */
1.8       mycroft  1432: int
1.211     perry    1433: ip_dooptions(struct mbuf *m)
1.1       cgd      1434: {
1.109     augustss 1435:        struct ip *ip = mtod(m, struct ip *);
                   1436:        u_char *cp, *cp0;
                   1437:        struct ip_timestamp *ipt;
                   1438:        struct in_ifaddr *ia;
1.1       cgd      1439:        int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1.104     thorpej  1440:        struct in_addr dst;
1.1       cgd      1441:        n_time ntime;
                   1442:
1.13      mycroft  1443:        dst = ip->ip_dst;
1.1       cgd      1444:        cp = (u_char *)(ip + 1);
                   1445:        cnt = (ip->ip_hl << 2) - sizeof (struct ip);
                   1446:        for (; cnt > 0; cnt -= optlen, cp += optlen) {
                   1447:                opt = cp[IPOPT_OPTVAL];
                   1448:                if (opt == IPOPT_EOL)
                   1449:                        break;
                   1450:                if (opt == IPOPT_NOP)
                   1451:                        optlen = 1;
                   1452:                else {
1.113     itojun   1453:                        if (cnt < IPOPT_OLEN + sizeof(*cp)) {
                   1454:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1455:                                goto bad;
                   1456:                        }
1.1       cgd      1457:                        optlen = cp[IPOPT_OLEN];
1.114     itojun   1458:                        if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1.1       cgd      1459:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1460:                                goto bad;
                   1461:                        }
                   1462:                }
                   1463:                switch (opt) {
                   1464:
                   1465:                default:
                   1466:                        break;
                   1467:
                   1468:                /*
                   1469:                 * Source routing with record.
                   1470:                 * Find interface with current destination address.
                   1471:                 * If none on this machine then drop if strictly routed,
                   1472:                 * or do nothing if loosely routed.
                   1473:                 * Record interface address and bring up next address
                   1474:                 * component.  If strictly routed make sure next
                   1475:                 * address is on directly accessible net.
                   1476:                 */
                   1477:                case IPOPT_LSRR:
                   1478:                case IPOPT_SSRR:
1.47      cjs      1479:                        if (ip_allowsrcrt == 0) {
                   1480:                                type = ICMP_UNREACH;
                   1481:                                code = ICMP_UNREACH_NET_PROHIB;
                   1482:                                goto bad;
                   1483:                        }
1.114     itojun   1484:                        if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
                   1485:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1486:                                goto bad;
                   1487:                        }
1.1       cgd      1488:                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                   1489:                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                   1490:                                goto bad;
                   1491:                        }
                   1492:                        ipaddr.sin_addr = ip->ip_dst;
1.19      mycroft  1493:                        ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1.1       cgd      1494:                        if (ia == 0) {
                   1495:                                if (opt == IPOPT_SSRR) {
                   1496:                                        type = ICMP_UNREACH;
                   1497:                                        code = ICMP_UNREACH_SRCFAIL;
                   1498:                                        goto bad;
                   1499:                                }
                   1500:                                /*
                   1501:                                 * Loose routing, and not at next destination
                   1502:                                 * yet; nothing to do except forward.
                   1503:                                 */
                   1504:                                break;
                   1505:                        }
                   1506:                        off--;                  /* 0 origin */
1.112     sommerfe 1507:                        if ((off + sizeof(struct in_addr)) > optlen) {
1.1       cgd      1508:                                /*
                   1509:                                 * End of source route.  Should be for us.
                   1510:                                 */
                   1511:                                save_rte(cp, ip->ip_src);
                   1512:                                break;
                   1513:                        }
                   1514:                        /*
                   1515:                         * locate outgoing interface
                   1516:                         */
                   1517:                        bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
                   1518:                            sizeof(ipaddr.sin_addr));
1.96      thorpej  1519:                        if (opt == IPOPT_SSRR)
1.196     itojun   1520:                                ia = ifatoia(ifa_ifwithladdr(sintosa(&ipaddr)));
1.96      thorpej  1521:                        else
1.1       cgd      1522:                                ia = ip_rtaddr(ipaddr.sin_addr);
                   1523:                        if (ia == 0) {
                   1524:                                type = ICMP_UNREACH;
                   1525:                                code = ICMP_UNREACH_SRCFAIL;
                   1526:                                goto bad;
                   1527:                        }
                   1528:                        ip->ip_dst = ipaddr.sin_addr;
1.20      mycroft  1529:                        bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd      1530:                            (caddr_t)(cp + off), sizeof(struct in_addr));
                   1531:                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1.13      mycroft  1532:                        /*
                   1533:                         * Let ip_intr's mcast routing check handle mcast pkts
                   1534:                         */
1.18      mycroft  1535:                        forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1.1       cgd      1536:                        break;
                   1537:
                   1538:                case IPOPT_RR:
1.114     itojun   1539:                        if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
                   1540:                                code = &cp[IPOPT_OLEN] - (u_char *)ip;
                   1541:                                goto bad;
                   1542:                        }
1.1       cgd      1543:                        if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
                   1544:                                code = &cp[IPOPT_OFFSET] - (u_char *)ip;
                   1545:                                goto bad;
                   1546:                        }
                   1547:                        /*
                   1548:                         * If no space remains, ignore.
                   1549:                         */
                   1550:                        off--;                  /* 0 origin */
1.112     sommerfe 1551:                        if ((off + sizeof(struct in_addr)) > optlen)
1.1       cgd      1552:                                break;
                   1553:                        bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
                   1554:                            sizeof(ipaddr.sin_addr));
                   1555:                        /*
                   1556:                         * locate outgoing interface; if we're the destination,
                   1557:                         * use the incoming interface (should be same).
                   1558:                         */
1.96      thorpej  1559:                        if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
                   1560:                            == NULL &&
                   1561:                            (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1.1       cgd      1562:                                type = ICMP_UNREACH;
                   1563:                                code = ICMP_UNREACH_HOST;
                   1564:                                goto bad;
                   1565:                        }
1.20      mycroft  1566:                        bcopy((caddr_t)&ia->ia_addr.sin_addr,
1.1       cgd      1567:                            (caddr_t)(cp + off), sizeof(struct in_addr));
                   1568:                        cp[IPOPT_OFFSET] += sizeof(struct in_addr);
                   1569:                        break;
                   1570:
                   1571:                case IPOPT_TS:
                   1572:                        code = cp - (u_char *)ip;
                   1573:                        ipt = (struct ip_timestamp *)cp;
1.114     itojun   1574:                        if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
                   1575:                                code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1.1       cgd      1576:                                goto bad;
1.114     itojun   1577:                        }
                   1578:                        if (ipt->ipt_ptr < 5) {
                   1579:                                code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
                   1580:                                goto bad;
                   1581:                        }
1.15      cgd      1582:                        if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1.114     itojun   1583:                                if (++ipt->ipt_oflw == 0) {
                   1584:                                        code = (u_char *)&ipt->ipt_ptr -
                   1585:                                            (u_char *)ip;
1.1       cgd      1586:                                        goto bad;
1.114     itojun   1587:                                }
1.1       cgd      1588:                                break;
                   1589:                        }
1.104     thorpej  1590:                        cp0 = (cp + ipt->ipt_ptr - 1);
1.1       cgd      1591:                        switch (ipt->ipt_flg) {
                   1592:
                   1593:                        case IPOPT_TS_TSONLY:
                   1594:                                break;
                   1595:
                   1596:                        case IPOPT_TS_TSANDADDR:
1.66      thorpej  1597:                                if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114     itojun   1598:                                    sizeof(struct in_addr) > ipt->ipt_len) {
                   1599:                                        code = (u_char *)&ipt->ipt_ptr -
                   1600:                                            (u_char *)ip;
1.1       cgd      1601:                                        goto bad;
1.114     itojun   1602:                                }
1.13      mycroft  1603:                                ipaddr.sin_addr = dst;
1.96      thorpej  1604:                                ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
                   1605:                                    m->m_pkthdr.rcvif));
1.13      mycroft  1606:                                if (ia == 0)
                   1607:                                        continue;
1.104     thorpej  1608:                                bcopy(&ia->ia_addr.sin_addr,
                   1609:                                    cp0, sizeof(struct in_addr));
1.1       cgd      1610:                                ipt->ipt_ptr += sizeof(struct in_addr);
                   1611:                                break;
                   1612:
                   1613:                        case IPOPT_TS_PRESPEC:
1.66      thorpej  1614:                                if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1.114     itojun   1615:                                    sizeof(struct in_addr) > ipt->ipt_len) {
                   1616:                                        code = (u_char *)&ipt->ipt_ptr -
                   1617:                                            (u_char *)ip;
1.1       cgd      1618:                                        goto bad;
1.114     itojun   1619:                                }
1.104     thorpej  1620:                                bcopy(cp0, &ipaddr.sin_addr,
1.1       cgd      1621:                                    sizeof(struct in_addr));
1.96      thorpej  1622:                                if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
                   1623:                                    == NULL)
1.1       cgd      1624:                                        continue;
                   1625:                                ipt->ipt_ptr += sizeof(struct in_addr);
                   1626:                                break;
                   1627:
                   1628:                        default:
1.114     itojun   1629:                                /* XXX can't take &ipt->ipt_flg */
                   1630:                                code = (u_char *)&ipt->ipt_ptr -
                   1631:                                    (u_char *)ip + 1;
1.1       cgd      1632:                                goto bad;
                   1633:                        }
                   1634:                        ntime = iptime();
1.107     thorpej  1635:                        cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
                   1636:                        bcopy(cp0, (caddr_t)cp + ipt->ipt_ptr - 1,
1.1       cgd      1637:                            sizeof(n_time));
                   1638:                        ipt->ipt_ptr += sizeof(n_time);
                   1639:                }
                   1640:        }
                   1641:        if (forward) {
1.26      thorpej  1642:                if (ip_forwsrcrt == 0) {
                   1643:                        type = ICMP_UNREACH;
                   1644:                        code = ICMP_UNREACH_SRCFAIL;
                   1645:                        goto bad;
                   1646:                }
1.1       cgd      1647:                ip_forward(m, 1);
                   1648:                return (1);
1.13      mycroft  1649:        }
                   1650:        return (0);
1.1       cgd      1651: bad:
1.13      mycroft  1652:        icmp_error(m, type, code, 0, 0);
                   1653:        ipstat.ips_badoptions++;
1.1       cgd      1654:        return (1);
                   1655: }
                   1656:
                   1657: /*
                   1658:  * Given address of next destination (final or next hop),
                   1659:  * return internet address info of interface to be used to get there.
                   1660:  */
                   1661: struct in_ifaddr *
1.211     perry    1662: ip_rtaddr(struct in_addr dst)
1.1       cgd      1663: {
1.109     augustss 1664:        struct sockaddr_in *sin;
1.1       cgd      1665:
1.19      mycroft  1666:        sin = satosin(&ipforward_rt.ro_dst);
1.1       cgd      1667:
1.35      mycroft  1668:        if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
1.1       cgd      1669:                if (ipforward_rt.ro_rt) {
                   1670:                        RTFREE(ipforward_rt.ro_rt);
                   1671:                        ipforward_rt.ro_rt = 0;
                   1672:                }
                   1673:                sin->sin_family = AF_INET;
                   1674:                sin->sin_len = sizeof(*sin);
                   1675:                sin->sin_addr = dst;
                   1676:
                   1677:                rtalloc(&ipforward_rt);
                   1678:        }
                   1679:        if (ipforward_rt.ro_rt == 0)
                   1680:                return ((struct in_ifaddr *)0);
1.19      mycroft  1681:        return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
1.1       cgd      1682: }
                   1683:
                   1684: /*
                   1685:  * Save incoming source route for use in replies,
                   1686:  * to be picked up later by ip_srcroute if the receiver is interested.
                   1687:  */
1.13      mycroft  1688: void
1.211     perry    1689: save_rte(u_char *option, struct in_addr dst)
1.1       cgd      1690: {
                   1691:        unsigned olen;
                   1692:
                   1693:        olen = option[IPOPT_OLEN];
                   1694: #ifdef DIAGNOSTIC
                   1695:        if (ipprintfs)
1.39      christos 1696:                printf("save_rte: olen %d\n", olen);
1.89      itojun   1697: #endif /* 0 */
1.1       cgd      1698:        if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
                   1699:                return;
                   1700:        bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
                   1701:        ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
                   1702:        ip_srcrt.dst = dst;
                   1703: }
                   1704:
                   1705: /*
                   1706:  * Retrieve incoming source route for use in replies,
                   1707:  * in the same form used by setsockopt.
                   1708:  * The first hop is placed before the options, will be removed later.
                   1709:  */
                   1710: struct mbuf *
1.211     perry    1711: ip_srcroute(void)
1.1       cgd      1712: {
1.109     augustss 1713:        struct in_addr *p, *q;
                   1714:        struct mbuf *m;
1.1       cgd      1715:
                   1716:        if (ip_nhops == 0)
                   1717:                return ((struct mbuf *)0);
                   1718:        m = m_get(M_DONTWAIT, MT_SOOPTS);
                   1719:        if (m == 0)
                   1720:                return ((struct mbuf *)0);
                   1721:
1.164     matt     1722:        MCLAIM(m, &inetdomain.dom_mowner);
1.13      mycroft  1723: #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1.1       cgd      1724:
                   1725:        /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
                   1726:        m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
                   1727:            OPTSIZ;
                   1728: #ifdef DIAGNOSTIC
                   1729:        if (ipprintfs)
1.39      christos 1730:                printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1.1       cgd      1731: #endif
                   1732:
                   1733:        /*
                   1734:         * First save first hop for return route
                   1735:         */
                   1736:        p = &ip_srcrt.route[ip_nhops - 1];
                   1737:        *(mtod(m, struct in_addr *)) = *p--;
                   1738: #ifdef DIAGNOSTIC
                   1739:        if (ipprintfs)
1.39      christos 1740:                printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1.1       cgd      1741: #endif
                   1742:
                   1743:        /*
                   1744:         * Copy option fields and padding (nop) to mbuf.
                   1745:         */
                   1746:        ip_srcrt.nop = IPOPT_NOP;
                   1747:        ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
                   1748:        bcopy((caddr_t)&ip_srcrt.nop,
                   1749:            mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
                   1750:        q = (struct in_addr *)(mtod(m, caddr_t) +
                   1751:            sizeof(struct in_addr) + OPTSIZ);
                   1752: #undef OPTSIZ
                   1753:        /*
                   1754:         * Record return path as an IP source route,
                   1755:         * reversing the path (pointers are now aligned).
                   1756:         */
                   1757:        while (p >= ip_srcrt.route) {
                   1758: #ifdef DIAGNOSTIC
                   1759:                if (ipprintfs)
1.39      christos 1760:                        printf(" %x", ntohl(q->s_addr));
1.1       cgd      1761: #endif
                   1762:                *q++ = *p--;
                   1763:        }
                   1764:        /*
                   1765:         * Last hop goes to final destination.
                   1766:         */
                   1767:        *q = ip_srcrt.dst;
                   1768: #ifdef DIAGNOSTIC
                   1769:        if (ipprintfs)
1.39      christos 1770:                printf(" %x\n", ntohl(q->s_addr));
1.1       cgd      1771: #endif
                   1772:        return (m);
                   1773: }
                   1774:
                   1775: /*
                   1776:  * Strip out IP options, at higher
                   1777:  * level protocol in the kernel.
                   1778:  * Second argument is buffer to which options
                   1779:  * will be moved, and return value is their length.
                   1780:  * XXX should be deleted; last arg currently ignored.
                   1781:  */
1.8       mycroft  1782: void
1.211     perry    1783: ip_stripoptions(struct mbuf *m, struct mbuf *mopt)
1.1       cgd      1784: {
1.109     augustss 1785:        int i;
1.1       cgd      1786:        struct ip *ip = mtod(m, struct ip *);
1.109     augustss 1787:        caddr_t opts;
1.1       cgd      1788:        int olen;
                   1789:
1.79      mycroft  1790:        olen = (ip->ip_hl << 2) - sizeof (struct ip);
1.1       cgd      1791:        opts = (caddr_t)(ip + 1);
                   1792:        i = m->m_len - (sizeof (struct ip) + olen);
                   1793:        bcopy(opts  + olen, opts, (unsigned)i);
                   1794:        m->m_len -= olen;
                   1795:        if (m->m_flags & M_PKTHDR)
                   1796:                m->m_pkthdr.len -= olen;
1.155     itojun   1797:        ip->ip_len = htons(ntohs(ip->ip_len) - olen);
1.79      mycroft  1798:        ip->ip_hl = sizeof (struct ip) >> 2;
1.1       cgd      1799: }
                   1800:
1.139     matt     1801: const int inetctlerrmap[PRC_NCMDS] = {
1.1       cgd      1802:        0,              0,              0,              0,
                   1803:        0,              EMSGSIZE,       EHOSTDOWN,      EHOSTUNREACH,
                   1804:        EHOSTUNREACH,   EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
                   1805:        EMSGSIZE,       EHOSTUNREACH,   0,              0,
                   1806:        0,              0,              0,              0,
                   1807:        ENOPROTOOPT
                   1808: };
                   1809:
                   1810: /*
                   1811:  * Forward a packet.  If some error occurs return the sender
                   1812:  * an icmp packet.  Note we can't always generate a meaningful
                   1813:  * icmp message because icmp doesn't have a large enough repertoire
                   1814:  * of codes and types.
                   1815:  *
                   1816:  * If not forwarding, just drop the packet.  This could be confusing
                   1817:  * if ipforwarding was zero but some routing protocol was advancing
                   1818:  * us as a gateway to somewhere.  However, we must let the routing
                   1819:  * protocol deal with that.
                   1820:  *
                   1821:  * The srcrt parameter indicates whether the packet is being forwarded
                   1822:  * via a source route.
                   1823:  */
1.13      mycroft  1824: void
1.211     perry    1825: ip_forward(struct mbuf *m, int srcrt)
1.1       cgd      1826: {
1.109     augustss 1827:        struct ip *ip = mtod(m, struct ip *);
                   1828:        struct sockaddr_in *sin;
                   1829:        struct rtentry *rt;
1.220     christos 1830:        int error, type = 0, code = 0, destmtu = 0;
1.1       cgd      1831:        struct mbuf *mcopy;
1.13      mycroft  1832:        n_long dest;
1.164     matt     1833:
                   1834:        /*
                   1835:         * We are now in the output path.
                   1836:         */
                   1837:        MCLAIM(m, &ip_tx_mowner);
1.135     thorpej  1838:
                   1839:        /*
                   1840:         * Clear any in-bound checksum flags for this packet.
                   1841:         */
                   1842:        m->m_pkthdr.csum_flags = 0;
1.1       cgd      1843:
1.13      mycroft  1844:        dest = 0;
1.1       cgd      1845: #ifdef DIAGNOSTIC
1.224     joerg    1846:        if (ipprintfs) {
                   1847:                printf("forward: src %s ", inet_ntoa(ip->ip_src));
                   1848:                printf("dst %s ttl %x\n", inet_ntoa(ip->ip_dst), ip->ip_ttl);
                   1849:        }
1.1       cgd      1850: #endif
1.93      sommerfe 1851:        if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1.1       cgd      1852:                ipstat.ips_cantforward++;
                   1853:                m_freem(m);
                   1854:                return;
                   1855:        }
                   1856:        if (ip->ip_ttl <= IPTTLDEC) {
1.13      mycroft  1857:                icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1.1       cgd      1858:                return;
                   1859:        }
                   1860:
1.19      mycroft  1861:        sin = satosin(&ipforward_rt.ro_dst);
1.1       cgd      1862:        if ((rt = ipforward_rt.ro_rt) == 0 ||
1.35      mycroft  1863:            !in_hosteq(ip->ip_dst, sin->sin_addr)) {
1.1       cgd      1864:                if (ipforward_rt.ro_rt) {
                   1865:                        RTFREE(ipforward_rt.ro_rt);
                   1866:                        ipforward_rt.ro_rt = 0;
                   1867:                }
                   1868:                sin->sin_family = AF_INET;
1.35      mycroft  1869:                sin->sin_len = sizeof(struct sockaddr_in);
1.1       cgd      1870:                sin->sin_addr = ip->ip_dst;
                   1871:
                   1872:                rtalloc(&ipforward_rt);
                   1873:                if (ipforward_rt.ro_rt == 0) {
1.218     seanb    1874:                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1.1       cgd      1875:                        return;
                   1876:                }
                   1877:                rt = ipforward_rt.ro_rt;
                   1878:        }
                   1879:
                   1880:        /*
1.34      mycroft  1881:         * Save at most 68 bytes of the packet in case
1.1       cgd      1882:         * we need to generate an ICMP message to the src.
1.119     itojun   1883:         * Pullup to avoid sharing mbuf cluster between m and mcopy.
1.1       cgd      1884:         */
1.155     itojun   1885:        mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1.119     itojun   1886:        if (mcopy)
                   1887:                mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1.1       cgd      1888:
1.221     christos 1889:        ip->ip_ttl -= IPTTLDEC;
                   1890:
1.1       cgd      1891:        /*
                   1892:         * If forwarding packet using same interface that it came in on,
                   1893:         * perhaps should send a redirect to sender to shortcut a hop.
                   1894:         * Only send redirect if source is sending directly to us,
                   1895:         * and if packet was not source routed (or has any options).
                   1896:         * Also, don't send redirect if forwarding using a default route
                   1897:         * or a route modified by a redirect.
                   1898:         */
                   1899:        if (rt->rt_ifp == m->m_pkthdr.rcvif &&
                   1900:            (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1.35      mycroft  1901:            !in_nullhost(satosin(rt_key(rt))->sin_addr) &&
1.1       cgd      1902:            ipsendredirects && !srcrt) {
1.19      mycroft  1903:                if (rt->rt_ifa &&
                   1904:                    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
                   1905:                    ifatoia(rt->rt_ifa)->ia_subnet) {
1.77      thorpej  1906:                        if (rt->rt_flags & RTF_GATEWAY)
                   1907:                                dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
                   1908:                        else
                   1909:                                dest = ip->ip_dst.s_addr;
                   1910:                        /*
                   1911:                         * Router requirements says to only send host
                   1912:                         * redirects.
                   1913:                         */
                   1914:                        type = ICMP_REDIRECT;
                   1915:                        code = ICMP_REDIRECT_HOST;
1.1       cgd      1916: #ifdef DIAGNOSTIC
1.77      thorpej  1917:                        if (ipprintfs)
                   1918:                                printf("redirect (%d) to %x\n", code,
                   1919:                                    (u_int32_t)dest);
1.1       cgd      1920: #endif
                   1921:                }
                   1922:        }
                   1923:
1.27      thorpej  1924:        error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1.173     jonathan 1925:            (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1.174     itojun   1926:            (struct ip_moptions *)NULL, (struct socket *)NULL);
1.173     jonathan 1927:
1.1       cgd      1928:        if (error)
                   1929:                ipstat.ips_cantforward++;
                   1930:        else {
                   1931:                ipstat.ips_forward++;
                   1932:                if (type)
                   1933:                        ipstat.ips_redirectsent++;
                   1934:                else {
1.63      matt     1935:                        if (mcopy) {
                   1936: #ifdef GATEWAY
1.64      thorpej  1937:                                if (mcopy->m_flags & M_CANFASTFWD)
                   1938:                                        ipflow_create(&ipforward_rt, mcopy);
1.63      matt     1939: #endif
1.1       cgd      1940:                                m_freem(mcopy);
1.63      matt     1941:                        }
1.1       cgd      1942:                        return;
                   1943:                }
                   1944:        }
                   1945:        if (mcopy == NULL)
                   1946:                return;
1.13      mycroft  1947:
1.1       cgd      1948:        switch (error) {
                   1949:
                   1950:        case 0:                         /* forwarded, but need redirect */
                   1951:                /* type, code set above */
                   1952:                break;
                   1953:
                   1954:        case ENETUNREACH:               /* shouldn't happen, checked above */
                   1955:        case EHOSTUNREACH:
                   1956:        case ENETDOWN:
                   1957:        case EHOSTDOWN:
                   1958:        default:
                   1959:                type = ICMP_UNREACH;
                   1960:                code = ICMP_UNREACH_HOST;
                   1961:                break;
                   1962:
                   1963:        case EMSGSIZE:
                   1964:                type = ICMP_UNREACH;
                   1965:                code = ICMP_UNREACH_NEEDFRAG;
1.173     jonathan 1966: #if !defined(IPSEC) && !defined(FAST_IPSEC)
1.13      mycroft  1967:                if (ipforward_rt.ro_rt)
1.220     christos 1968:                        destmtu = ipforward_rt.ro_rt->rt_ifp->if_mtu;
1.89      itojun   1969: #else
                   1970:                /*
                   1971:                 * If the packet is routed over IPsec tunnel, tell the
                   1972:                 * originator the tunnel MTU.
                   1973:                 *      tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
                   1974:                 * XXX quickhack!!!
                   1975:                 */
                   1976:                if (ipforward_rt.ro_rt) {
                   1977:                        struct secpolicy *sp;
                   1978:                        int ipsecerror;
1.95      itojun   1979:                        size_t ipsechdr;
1.89      itojun   1980:                        struct route *ro;
                   1981:
                   1982:                        sp = ipsec4_getpolicybyaddr(mcopy,
1.170     itojun   1983:                            IPSEC_DIR_OUTBOUND, IP_FORWARDING,
                   1984:                            &ipsecerror);
1.89      itojun   1985:
                   1986:                        if (sp == NULL)
1.220     christos 1987:                                destmtu = ipforward_rt.ro_rt->rt_ifp->if_mtu;
1.89      itojun   1988:                        else {
                   1989:                                /* count IPsec header size */
1.95      itojun   1990:                                ipsechdr = ipsec4_hdrsiz(mcopy,
1.170     itojun   1991:                                    IPSEC_DIR_OUTBOUND, NULL);
1.89      itojun   1992:
                   1993:                                /*
                   1994:                                 * find the correct route for outer IPv4
                   1995:                                 * header, compute tunnel MTU.
                   1996:                                 */
1.220     christos 1997:
1.89      itojun   1998:                                if (sp->req != NULL
1.95      itojun   1999:                                 && sp->req->sav != NULL
                   2000:                                 && sp->req->sav->sah != NULL) {
                   2001:                                        ro = &sp->req->sav->sah->sa_route;
1.89      itojun   2002:                                        if (ro->ro_rt && ro->ro_rt->rt_ifp) {
1.220     christos 2003:                                                destmtu =
1.151     itojun   2004:                                                    ro->ro_rt->rt_rmx.rmx_mtu ?
                   2005:                                                    ro->ro_rt->rt_rmx.rmx_mtu :
1.89      itojun   2006:                                                    ro->ro_rt->rt_ifp->if_mtu;
1.220     christos 2007:                                                destmtu -= ipsechdr;
1.89      itojun   2008:                                        }
                   2009:                                }
                   2010:
1.173     jonathan 2011: #ifdef IPSEC
1.89      itojun   2012:                                key_freesp(sp);
1.173     jonathan 2013: #else
                   2014:                                KEY_FREESP(&sp);
                   2015: #endif
1.89      itojun   2016:                        }
                   2017:                }
                   2018: #endif /*IPSEC*/
1.1       cgd      2019:                ipstat.ips_cantfrag++;
                   2020:                break;
                   2021:
                   2022:        case ENOBUFS:
1.143     itojun   2023: #if 1
                   2024:                /*
                   2025:                 * a router should not generate ICMP_SOURCEQUENCH as
                   2026:                 * required in RFC1812 Requirements for IP Version 4 Routers.
                   2027:                 * source quench could be a big problem under DoS attacks,
1.149     wiz      2028:                 * or if the underlying interface is rate-limited.
1.143     itojun   2029:                 */
                   2030:                if (mcopy)
                   2031:                        m_freem(mcopy);
                   2032:                return;
                   2033: #else
1.1       cgd      2034:                type = ICMP_SOURCEQUENCH;
                   2035:                code = 0;
                   2036:                break;
1.143     itojun   2037: #endif
1.1       cgd      2038:        }
1.220     christos 2039:        icmp_error(mcopy, type, code, dest, destmtu);
1.44      thorpej  2040: }
                   2041:
                   2042: void
1.211     perry    2043: ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
                   2044:     struct mbuf *m)
1.44      thorpej  2045: {
                   2046:
                   2047:        if (inp->inp_socket->so_options & SO_TIMESTAMP) {
                   2048:                struct timeval tv;
                   2049:
                   2050:                microtime(&tv);
                   2051:                *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
                   2052:                    SCM_TIMESTAMP, SOL_SOCKET);
                   2053:                if (*mp)
                   2054:                        mp = &(*mp)->m_next;
                   2055:        }
                   2056:        if (inp->inp_flags & INP_RECVDSTADDR) {
                   2057:                *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
                   2058:                    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
                   2059:                if (*mp)
                   2060:                        mp = &(*mp)->m_next;
                   2061:        }
                   2062: #ifdef notyet
                   2063:        /*
                   2064:         * XXX
                   2065:         * Moving these out of udp_input() made them even more broken
                   2066:         * than they already were.
                   2067:         *      - fenner@parc.xerox.com
                   2068:         */
                   2069:        /* options were tossed already */
                   2070:        if (inp->inp_flags & INP_RECVOPTS) {
                   2071:                *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
                   2072:                    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
                   2073:                if (*mp)
                   2074:                        mp = &(*mp)->m_next;
                   2075:        }
                   2076:        /* ip_srcroute doesn't do what we want here, need to fix */
                   2077:        if (inp->inp_flags & INP_RECVRETOPTS) {
                   2078:                *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
                   2079:                    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
                   2080:                if (*mp)
                   2081:                        mp = &(*mp)->m_next;
                   2082:        }
                   2083: #endif
                   2084:        if (inp->inp_flags & INP_RECVIF) {
                   2085:                struct sockaddr_dl sdl;
                   2086:
                   2087:                sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
                   2088:                sdl.sdl_family = AF_LINK;
                   2089:                sdl.sdl_index = m->m_pkthdr.rcvif ?
                   2090:                    m->m_pkthdr.rcvif->if_index : 0;
                   2091:                sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
                   2092:                *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
                   2093:                    IP_RECVIF, IPPROTO_IP);
                   2094:                if (*mp)
                   2095:                        mp = &(*mp)->m_next;
                   2096:        }
1.13      mycroft  2097: }
                   2098:
1.189     atatat   2099: /*
1.224.2.3  yamt     2100:  * sysctl helper routine for net.inet.ip.forwsrcrt.
                   2101:  */
                   2102: static int
                   2103: sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
                   2104: {
                   2105:        int error, tmp;
                   2106:        struct sysctlnode node;
                   2107:
                   2108:        node = *rnode;
                   2109:        tmp = ip_forwsrcrt;
                   2110:        node.sysctl_data = &tmp;
                   2111:        error = sysctl_lookup(SYSCTLFN_CALL(&node));
                   2112:        if (error || newp == NULL)
                   2113:                return (error);
                   2114:
1.224.2.5! yamt     2115:        if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
        !          2116:            NULL, NULL, NULL, NULL))
1.224.2.3  yamt     2117:                return (EPERM);
                   2118:
                   2119:        ip_forwsrcrt = tmp;
                   2120:
                   2121:        return (0);
                   2122: }
                   2123:
                   2124: /*
1.189     atatat   2125:  * sysctl helper routine for net.inet.ip.mtudisctimeout.  checks the
                   2126:  * range of the new value and tweaks timers if it changes.
                   2127:  */
                   2128: static int
                   2129: sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1.13      mycroft  2130: {
1.189     atatat   2131:        int error, tmp;
                   2132:        struct sysctlnode node;
                   2133:
                   2134:        node = *rnode;
                   2135:        tmp = ip_mtudisc_timeout;
                   2136:        node.sysctl_data = &tmp;
                   2137:        error = sysctl_lookup(SYSCTLFN_CALL(&node));
                   2138:        if (error || newp == NULL)
                   2139:                return (error);
                   2140:        if (tmp < 0)
                   2141:                return (EINVAL);
1.52      thorpej  2142:
1.189     atatat   2143:        ip_mtudisc_timeout = tmp;
                   2144:        rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
                   2145:
                   2146:        return (0);
                   2147: }
1.54      lukem    2148:
1.65      matt     2149: #ifdef GATEWAY
1.189     atatat   2150: /*
                   2151:  * sysctl helper routine for net.inet.ip.maxflows.  apparently if
                   2152:  * maxflows is even looked up, we "reap flows".
                   2153:  */
                   2154: static int
                   2155: sysctl_net_inet_ip_maxflows(SYSCTLFN_ARGS)
                   2156: {
                   2157:        int s;
1.67      thorpej  2158:
1.217     atatat   2159:        s = sysctl_lookup(SYSCTLFN_CALL(rnode));
1.189     atatat   2160:        if (s)
                   2161:                return (s);
1.212     perry    2162:
1.189     atatat   2163:        s = splsoftnet();
                   2164:        ipflow_reap(0);
                   2165:        splx(s);
1.144     martin   2166:
1.189     atatat   2167:        return (0);
                   2168: }
                   2169: #endif /* GATEWAY */
1.117     tron     2170:
1.131     itojun   2171:
1.189     atatat   2172: SYSCTL_SETUP(sysctl_net_inet_ip_setup, "sysctl net.inet.ip subtree setup")
                   2173: {
                   2174:        extern int subnetsarelocal, hostzeroisbroadcast;
1.180     jonathan 2175:
1.197     atatat   2176:        sysctl_createv(clog, 0, NULL, NULL,
                   2177:                       CTLFLAG_PERMANENT,
1.189     atatat   2178:                       CTLTYPE_NODE, "net", NULL,
                   2179:                       NULL, 0, NULL, 0,
                   2180:                       CTL_NET, CTL_EOL);
1.197     atatat   2181:        sysctl_createv(clog, 0, NULL, NULL,
                   2182:                       CTLFLAG_PERMANENT,
1.203     atatat   2183:                       CTLTYPE_NODE, "inet",
                   2184:                       SYSCTL_DESCR("PF_INET related settings"),
1.189     atatat   2185:                       NULL, 0, NULL, 0,
                   2186:                       CTL_NET, PF_INET, CTL_EOL);
1.197     atatat   2187:        sysctl_createv(clog, 0, NULL, NULL,
                   2188:                       CTLFLAG_PERMANENT,
1.203     atatat   2189:                       CTLTYPE_NODE, "ip",
                   2190:                       SYSCTL_DESCR("IPv4 related settings"),
1.189     atatat   2191:                       NULL, 0, NULL, 0,
                   2192:                       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1.212     perry    2193:
1.197     atatat   2194:        sysctl_createv(clog, 0, NULL, NULL,
                   2195:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2196:                       CTLTYPE_INT, "forwarding",
                   2197:                       SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1.189     atatat   2198:                       NULL, 0, &ipforwarding, 0,
                   2199:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2200:                       IPCTL_FORWARDING, CTL_EOL);
1.197     atatat   2201:        sysctl_createv(clog, 0, NULL, NULL,
                   2202:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2203:                       CTLTYPE_INT, "redirect",
                   2204:                       SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1.189     atatat   2205:                       NULL, 0, &ipsendredirects, 0,
                   2206:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2207:                       IPCTL_SENDREDIRECTS, CTL_EOL);
1.197     atatat   2208:        sysctl_createv(clog, 0, NULL, NULL,
                   2209:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2210:                       CTLTYPE_INT, "ttl",
                   2211:                       SYSCTL_DESCR("Default TTL for an INET datagram"),
1.189     atatat   2212:                       NULL, 0, &ip_defttl, 0,
                   2213:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2214:                       IPCTL_DEFTTL, CTL_EOL);
                   2215: #ifdef IPCTL_DEFMTU
1.197     atatat   2216:        sysctl_createv(clog, 0, NULL, NULL,
                   2217:                       CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */,
1.203     atatat   2218:                       CTLTYPE_INT, "mtu",
                   2219:                       SYSCTL_DESCR("Default MTA for an INET route"),
1.189     atatat   2220:                       NULL, 0, &ip_mtu, 0,
                   2221:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2222:                       IPCTL_DEFMTU, CTL_EOL);
                   2223: #endif /* IPCTL_DEFMTU */
1.197     atatat   2224:        sysctl_createv(clog, 0, NULL, NULL,
1.224.2.3  yamt     2225:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2226:                       CTLTYPE_INT, "forwsrcrt",
                   2227:                       SYSCTL_DESCR("Enable forwarding of source-routed "
                   2228:                                    "datagrams"),
1.224.2.3  yamt     2229:                       sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1.189     atatat   2230:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2231:                       IPCTL_FORWSRCRT, CTL_EOL);
1.197     atatat   2232:        sysctl_createv(clog, 0, NULL, NULL,
                   2233:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2234:                       CTLTYPE_INT, "directed-broadcast",
                   2235:                       SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1.189     atatat   2236:                       NULL, 0, &ip_directedbcast, 0,
                   2237:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2238:                       IPCTL_DIRECTEDBCAST, CTL_EOL);
1.197     atatat   2239:        sysctl_createv(clog, 0, NULL, NULL,
                   2240:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2241:                       CTLTYPE_INT, "allowsrcrt",
                   2242:                       SYSCTL_DESCR("Accept source-routed datagrams"),
1.189     atatat   2243:                       NULL, 0, &ip_allowsrcrt, 0,
                   2244:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2245:                       IPCTL_ALLOWSRCRT, CTL_EOL);
1.197     atatat   2246:        sysctl_createv(clog, 0, NULL, NULL,
                   2247:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2248:                       CTLTYPE_INT, "subnetsarelocal",
                   2249:                       SYSCTL_DESCR("Whether logical subnets are considered "
                   2250:                                    "local"),
1.189     atatat   2251:                       NULL, 0, &subnetsarelocal, 0,
                   2252:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2253:                       IPCTL_SUBNETSARELOCAL, CTL_EOL);
1.197     atatat   2254:        sysctl_createv(clog, 0, NULL, NULL,
                   2255:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2256:                       CTLTYPE_INT, "mtudisc",
                   2257:                       SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1.189     atatat   2258:                       NULL, 0, &ip_mtudisc, 0,
                   2259:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2260:                       IPCTL_MTUDISC, CTL_EOL);
1.197     atatat   2261:        sysctl_createv(clog, 0, NULL, NULL,
                   2262:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2263:                       CTLTYPE_INT, "anonportmin",
                   2264:                       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1.189     atatat   2265:                       sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
                   2266:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2267:                       IPCTL_ANONPORTMIN, CTL_EOL);
1.197     atatat   2268:        sysctl_createv(clog, 0, NULL, NULL,
                   2269:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2270:                       CTLTYPE_INT, "anonportmax",
                   2271:                       SYSCTL_DESCR("Highest ephemeral port number to assign"),
1.189     atatat   2272:                       sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
                   2273:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2274:                       IPCTL_ANONPORTMAX, CTL_EOL);
1.197     atatat   2275:        sysctl_createv(clog, 0, NULL, NULL,
                   2276:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2277:                       CTLTYPE_INT, "mtudisctimeout",
                   2278:                       SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1.189     atatat   2279:                       sysctl_net_inet_ip_pmtudto, 0, &ip_mtudisc_timeout, 0,
                   2280:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2281:                       IPCTL_MTUDISCTIMEOUT, CTL_EOL);
                   2282: #ifdef GATEWAY
1.197     atatat   2283:        sysctl_createv(clog, 0, NULL, NULL,
                   2284:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2285:                       CTLTYPE_INT, "maxflows",
                   2286:                       SYSCTL_DESCR("Number of flows for fast forwarding"),
1.189     atatat   2287:                       sysctl_net_inet_ip_maxflows, 0, &ip_maxflows, 0,
                   2288:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2289:                       IPCTL_MAXFLOWS, CTL_EOL);
                   2290: #endif /* GATEWAY */
1.197     atatat   2291:        sysctl_createv(clog, 0, NULL, NULL,
                   2292:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2293:                       CTLTYPE_INT, "hostzerobroadcast",
                   2294:                       SYSCTL_DESCR("All zeroes address is broadcast address"),
1.189     atatat   2295:                       NULL, 0, &hostzeroisbroadcast, 0,
                   2296:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2297:                       IPCTL_HOSTZEROBROADCAST, CTL_EOL);
                   2298: #if NGIF > 0
1.197     atatat   2299:        sysctl_createv(clog, 0, NULL, NULL,
                   2300:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2301:                       CTLTYPE_INT, "gifttl",
                   2302:                       SYSCTL_DESCR("Default TTL for a gif tunnel datagram"),
1.189     atatat   2303:                       NULL, 0, &ip_gif_ttl, 0,
                   2304:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2305:                       IPCTL_GIF_TTL, CTL_EOL);
                   2306: #endif /* NGIF */
                   2307: #ifndef IPNOPRIVPORTS
1.197     atatat   2308:        sysctl_createv(clog, 0, NULL, NULL,
                   2309:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2310:                       CTLTYPE_INT, "lowportmin",
                   2311:                       SYSCTL_DESCR("Lowest privileged ephemeral port number "
                   2312:                                    "to assign"),
1.189     atatat   2313:                       sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
                   2314:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2315:                       IPCTL_LOWPORTMIN, CTL_EOL);
1.197     atatat   2316:        sysctl_createv(clog, 0, NULL, NULL,
                   2317:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2318:                       CTLTYPE_INT, "lowportmax",
                   2319:                       SYSCTL_DESCR("Highest privileged ephemeral port number "
                   2320:                                    "to assign"),
1.189     atatat   2321:                       sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
                   2322:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2323:                       IPCTL_LOWPORTMAX, CTL_EOL);
                   2324: #endif /* IPNOPRIVPORTS */
1.197     atatat   2325:        sysctl_createv(clog, 0, NULL, NULL,
                   2326:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2327:                       CTLTYPE_INT, "maxfragpackets",
                   2328:                       SYSCTL_DESCR("Maximum number of fragments to retain for "
                   2329:                                    "possible reassembly"),
1.189     atatat   2330:                       NULL, 0, &ip_maxfragpackets, 0,
                   2331:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2332:                       IPCTL_MAXFRAGPACKETS, CTL_EOL);
                   2333: #if NGRE > 0
1.197     atatat   2334:        sysctl_createv(clog, 0, NULL, NULL,
                   2335:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2336:                       CTLTYPE_INT, "grettl",
                   2337:                       SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1.189     atatat   2338:                       NULL, 0, &ip_gre_ttl, 0,
                   2339:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2340:                       IPCTL_GRE_TTL, CTL_EOL);
                   2341: #endif /* NGRE */
1.197     atatat   2342:        sysctl_createv(clog, 0, NULL, NULL,
                   2343:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2344:                       CTLTYPE_INT, "checkinterface",
                   2345:                       SYSCTL_DESCR("Enable receive side of Strong ES model "
                   2346:                                    "from RFC1122"),
1.189     atatat   2347:                       NULL, 0, &ip_checkinterface, 0,
                   2348:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2349:                       IPCTL_CHECKINTERFACE, CTL_EOL);
1.197     atatat   2350:        sysctl_createv(clog, 0, NULL, NULL,
                   2351:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1.203     atatat   2352:                       CTLTYPE_INT, "random_id",
                   2353:                       SYSCTL_DESCR("Assign random ip_id values"),
1.189     atatat   2354:                       NULL, 0, &ip_do_randomid, 0,
                   2355:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2356:                       IPCTL_RANDOMID, CTL_EOL);
1.206     thorpej  2357:        sysctl_createv(clog, 0, NULL, NULL,
                   2358:                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                   2359:                       CTLTYPE_INT, "do_loopback_cksum",
                   2360:                       SYSCTL_DESCR("Perform IP checksum on loopback"),
                   2361:                       NULL, 0, &ip_do_loopback_cksum, 0,
                   2362:                       CTL_NET, PF_INET, IPPROTO_IP,
                   2363:                       IPCTL_LOOPBACKCKSUM, CTL_EOL);
1.219     elad     2364:        sysctl_createv(clog, 0, NULL, NULL,
                   2365:                       CTLFLAG_PERMANENT,
                   2366:                       CTLTYPE_STRUCT, "stats",
                   2367:                       SYSCTL_DESCR("IP statistics"),
                   2368:                       NULL, 0, &ipstat, sizeof(ipstat),
                   2369:                       CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
                   2370:                       CTL_EOL);
1.1       cgd      2371: }

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