sys/netinet/ip_input.c

   1 /*
   2  * Copyright (c) 2003, 2004 Jeffrey M. Hsu.  All rights reserved.
   3  * Copyright (c) 2003, 2004 The DragonFly Project.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to The DragonFly Project
   6  * by Jeffrey M. Hsu.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of The DragonFly Project nor the names of its
  17  *    contributors may be used to endorse or promote products derived
  18  *    from this software without specific, prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  24  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Copyright (c) 1982, 1986, 1988, 1993
  36  *      The Regents of the University of California.  All rights reserved.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. Neither the name of the University nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  60  * SUCH DAMAGE.
  61  *
  62  *      @(#)ip_input.c  8.2 (Berkeley) 1/4/94
  63  * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.52 2003/03/07 07:01:28 silby Exp $
  64  */
  65
  66 #define _IP_VHL
  67
  68 #include "opt_bootp.h"
  69 #include "opt_ipdn.h"
  70 #include "opt_ipdivert.h"
  71 #include "opt_ipstealth.h"
  72 #include "opt_ipsec.h"
  73 #include "opt_rss.h"
  74
  75 #include <sys/param.h>
  76 #include <sys/systm.h>
  77 #include <sys/mbuf.h>
  78 #include <sys/malloc.h>
  79 #include <sys/mpipe.h>
  80 #include <sys/domain.h>
  81 #include <sys/protosw.h>
  82 #include <sys/socket.h>
  83 #include <sys/time.h>
  84 #include <sys/globaldata.h>
  85 #include <sys/thread.h>
  86 #include <sys/kernel.h>
  87 #include <sys/syslog.h>
  88 #include <sys/sysctl.h>
  89 #include <sys/in_cksum.h>
  90 #include <sys/lock.h>
  91
  92 #include <sys/mplock2.h>
  93
  94 #include <machine/stdarg.h>
  95
  96 #include <net/if.h>
  97 #include <net/if_types.h>
  98 #include <net/if_var.h>
  99 #include <net/if_dl.h>
 100 #include <net/pfil.h>
 101 #include <net/route.h>
 102 #include <net/netisr2.h>
 103
 104 #include <netinet/in.h>
 105 #include <netinet/in_systm.h>
 106 #include <netinet/in_var.h>
 107 #include <netinet/ip.h>
 108 #include <netinet/in_pcb.h>
 109 #include <netinet/ip_var.h>
 110 #include <netinet/ip_icmp.h>
 111 #include <netinet/ip_divert.h>
 112 #include <netinet/ip_flow.h>
 113
 114 #include <sys/thread2.h>
 115 #include <sys/msgport2.h>
 116 #include <net/netmsg2.h>
 117
 118 #include <sys/socketvar.h>
 119
 120 #include <net/ipfw/ip_fw.h>
 121 #include <net/dummynet/ip_dummynet.h>
 122
 123 #ifdef IPSEC
 124 #include <netinet6/ipsec.h>
 125 #include <netproto/key/key.h>
 126 #endif
 127
 128 #ifdef FAST_IPSEC
 129 #include <netproto/ipsec/ipsec.h>
 130 #include <netproto/ipsec/key.h>
 131 #endif
 132
 133 int rsvp_on = 0;
 134 static int ip_rsvp_on;
 135 struct socket *ip_rsvpd;
 136
 137 int ipforwarding = 0;
 138 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
 139     &ipforwarding, 0, "Enable IP forwarding between interfaces");
 140
 141 static int ipsendredirects = 1; /* XXX */
 142 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
 143     &ipsendredirects, 0, "Enable sending IP redirects");
 144
 145 int ip_defttl = IPDEFTTL;
 146 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
 147     &ip_defttl, 0, "Maximum TTL on IP packets");
 148
 149 static int ip_dosourceroute = 0;
 150 SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
 151     &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
 152
 153 static int ip_acceptsourceroute = 0;
 154 SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
 155     CTLFLAG_RW, &ip_acceptsourceroute, 0,
 156     "Enable accepting source routed IP packets");
 157
 158 static int ip_keepfaith = 0;
 159 SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
 160     &ip_keepfaith, 0,
 161     "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
 162
 163 static int maxnipq;
 164 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
 165     &maxnipq, 0,
 166     "Maximum number of IPv4 fragment reassembly queue entries");
 167
 168 static int maxfragsperpacket;
 169 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
 170     &maxfragsperpacket, 0,
 171     "Maximum number of IPv4 fragments allowed per packet");
 172
 173 static int ip_sendsourcequench = 0;
 174 SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
 175     &ip_sendsourcequench, 0,
 176     "Enable the transmission of source quench packets");
 177
 178 int ip_do_randomid = 1;
 179 SYSCTL_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
 180     &ip_do_randomid, 0,
 181     "Assign random ip_id values");
 182 /*
 183  * XXX - Setting ip_checkinterface mostly implements the receive side of
 184  * the Strong ES model described in RFC 1122, but since the routing table
 185  * and transmit implementation do not implement the Strong ES model,
 186  * setting this to 1 results in an odd hybrid.
 187  *
 188  * XXX - ip_checkinterface currently must be disabled if you use ipnat
 189  * to translate the destination address to another local interface.
 190  *
 191  * XXX - ip_checkinterface must be disabled if you add IP aliases
 192  * to the loopback interface instead of the interface where the
 193  * packets for those addresses are received.
 194  */
 195 static int ip_checkinterface = 0;
 196 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
 197     &ip_checkinterface, 0, "Verify packet arrives on correct interface");
 198
 199 static u_long ip_hash_count = 0;
 200 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, hash_count, CTLFLAG_RD,
 201     &ip_hash_count, 0, "Number of packets hashed by IP");
 202
 203 #ifdef RSS_DEBUG
 204 static u_long ip_rehash_count = 0;
 205 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, rehash_count, CTLFLAG_RD,
 206     &ip_rehash_count, 0, "Number of packets rehashed by IP");
 207
 208 static u_long ip_dispatch_fast = 0;
 209 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_fast_count, CTLFLAG_RD,
 210     &ip_dispatch_fast, 0, "Number of packets handled on current CPU");
 211
 212 static u_long ip_dispatch_slow = 0;
 213 SYSCTL_ULONG(_net_inet_ip, OID_AUTO, dispatch_slow_count, CTLFLAG_RD,
 214     &ip_dispatch_slow, 0, "Number of packets messaged to another CPU");
 215 #endif
 216
 217 #ifdef DIAGNOSTIC
 218 static int ipprintfs = 0;
 219 #endif
 220
 221 extern  struct domain inetdomain;
 222 extern  struct protosw inetsw[];
 223 u_char  ip_protox[IPPROTO_MAX];
 224 struct  in_ifaddrhead in_ifaddrheads[MAXCPU];   /* first inet address */
 225 struct  in_ifaddrhashhead *in_ifaddrhashtbls[MAXCPU];
 226                                                 /* inet addr hash table */
 227 u_long  in_ifaddrhmask;                         /* mask for hash table */
 228
 229 static struct mbuf *ipforward_mtemp[MAXCPU];
 230
 231 struct ip_stats ipstats_percpu[MAXCPU] __cachealign;
 232
 233 static int
 234 sysctl_ipstats(SYSCTL_HANDLER_ARGS)
 235 {
 236         int cpu, error = 0;
 237
 238         for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
 239                 if ((error = SYSCTL_OUT(req, &ipstats_percpu[cpu],
 240                                         sizeof(struct ip_stats))))
 241                         break;
 242                 if ((error = SYSCTL_IN(req, &ipstats_percpu[cpu],
 243                                        sizeof(struct ip_stats))))
 244                         break;
 245         }
 246
 247         return (error);
 248 }
 249 SYSCTL_PROC(_net_inet_ip, IPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
 250     0, 0, sysctl_ipstats, "S,ip_stats", "IP statistics");
 251
 252 /* Packet reassembly stuff */
 253 #define IPREASS_NHASH_LOG2      6
 254 #define IPREASS_NHASH           (1 << IPREASS_NHASH_LOG2)
 255 #define IPREASS_HMASK           (IPREASS_NHASH - 1)
 256 #define IPREASS_HASH(x,y)                                               \
 257     (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
 258
 259 TAILQ_HEAD(ipqhead, ipq);
 260 struct ipfrag_queue {
 261         int                     nipq;
 262         volatile int            draining;
 263         struct netmsg_base      timeo_netmsg;
 264         struct callout          timeo_ch;
 265         struct netmsg_base      drain_netmsg;
 266         struct ipqhead          ipq[IPREASS_NHASH];
 267 } __cachealign;
 268
 269 static struct ipfrag_queue      ipfrag_queue_pcpu[MAXCPU];
 270
 271 #ifdef IPCTL_DEFMTU
 272 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
 273     &ip_mtu, 0, "Default MTU");
 274 #endif
 275
 276 #ifdef IPSTEALTH
 277 static int ipstealth = 0;
 278 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW, &ipstealth, 0, "");
 279 #else
 280 static const int ipstealth = 0;
 281 #endif
 282
 283 struct mbuf *(*ip_divert_p)(struct mbuf *, int, int);
 284
 285 struct pfil_head inet_pfil_hook;
 286
 287 /*
 288  * struct ip_srcrt_opt is used to store packet state while it travels
 289  * through the stack.
 290  *
 291  * XXX Note that the code even makes assumptions on the size and
 292  * alignment of fields inside struct ip_srcrt so e.g. adding some
 293  * fields will break the code.  This needs to be fixed.
 294  *
 295  * We need to save the IP options in case a protocol wants to respond
 296  * to an incoming packet over the same route if the packet got here
 297  * using IP source routing.  This allows connection establishment and
 298  * maintenance when the remote end is on a network that is not known
 299  * to us.
 300  */
 301 struct ip_srcrt {
 302         struct  in_addr dst;                    /* final destination */
 303         char    nop;                            /* one NOP to align */
 304         char    srcopt[IPOPT_OFFSET + 1];       /* OPTVAL, OLEN and OFFSET */
 305         struct  in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
 306 };
 307
 308 struct ip_srcrt_opt {
 309         int             ip_nhops;
 310         struct ip_srcrt ip_srcrt;
 311 };
 312
 313 #define IPFRAG_MPIPE_MAX        4096
 314 #define MAXIPFRAG_MIN           ((IPFRAG_MPIPE_MAX * 2) / 256)
 315
 316 #define IPFRAG_TIMEO            (hz / PR_SLOWHZ)
 317
 318 static MALLOC_DEFINE(M_IPQ, "ipq", "IP Fragment Management");
 319 static struct malloc_pipe ipq_mpipe;
 320
 321 static void             save_rte(struct mbuf *, u_char *, struct in_addr);
 322 static int              ip_dooptions(struct mbuf *m, int, struct sockaddr_in *);
 323 static void             ip_freef(struct ipfrag_queue *, struct ipqhead *,
 324                             struct ipq *);
 325 static void             ip_input_handler(netmsg_t);
 326
 327 static void             ipfrag_timeo_dispatch(netmsg_t);
 328 static void             ipfrag_timeo(void *);
 329 static void             ipfrag_drain_dispatch(netmsg_t);
 330
 331 /*
 332  * IP initialization: fill in IP protocol switch table.
 333  * All protocols not implemented in kernel go to raw IP protocol handler.
 334  */
 335 void
 336 ip_init(void)
 337 {
 338         struct ipfrag_queue *fragq;
 339         struct protosw *pr;
 340         int cpu, i;
 341
 342         /*
 343          * Make sure we can handle a reasonable number of fragments but
 344          * cap it at IPFRAG_MPIPE_MAX.
 345          */
 346         mpipe_init(&ipq_mpipe, M_IPQ, sizeof(struct ipq),
 347             IFQ_MAXLEN, IPFRAG_MPIPE_MAX, 0, NULL, NULL, NULL);
 348
 349         /*
 350          * Make in_ifaddrhead and in_ifaddrhashtbl available on all CPUs,
 351          * since they could be accessed by any threads.
 352          */
 353         for (cpu = 0; cpu < ncpus; ++cpu) {
 354                 TAILQ_INIT(&in_ifaddrheads[cpu]);
 355                 in_ifaddrhashtbls[cpu] =
 356                     hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
 357         }
 358
 359         pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
 360         if (pr == NULL)
 361                 panic("ip_init");
 362         for (i = 0; i < IPPROTO_MAX; i++)
 363                 ip_protox[i] = pr - inetsw;
 364         for (pr = inetdomain.dom_protosw;
 365              pr < inetdomain.dom_protoswNPROTOSW; pr++) {
 366                 if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol) {
 367                         if (pr->pr_protocol != IPPROTO_RAW)
 368                                 ip_protox[pr->pr_protocol] = pr - inetsw;
 369                 }
 370         }
 371
 372         inet_pfil_hook.ph_type = PFIL_TYPE_AF;
 373         inet_pfil_hook.ph_af = AF_INET;
 374         if ((i = pfil_head_register(&inet_pfil_hook)) != 0) {
 375                 kprintf("%s: WARNING: unable to register pfil hook, "
 376                         "error %d\n", __func__, i);
 377         }
 378
 379         maxnipq = (nmbclusters / 32) / netisr_ncpus;
 380         if (maxnipq < MAXIPFRAG_MIN)
 381                 maxnipq = MAXIPFRAG_MIN;
 382         maxfragsperpacket = 16;
 383
 384         ip_id = time_second & 0xffff;   /* time_second survives reboots */
 385
 386         for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
 387                 /*
 388                  * Initialize IP statistics counters for each CPU.
 389                  */
 390                 bzero(&ipstats_percpu[cpu], sizeof(struct ip_stats));
 391
 392                 /*
 393                  * Preallocate mbuf template for forwarding
 394                  */
 395                 MGETHDR(ipforward_mtemp[cpu], M_WAITOK, MT_DATA);
 396
 397                 /*
 398                  * Initialize per-cpu ip fragments queues
 399                  */
 400                 fragq = &ipfrag_queue_pcpu[cpu];
 401                 for (i = 0; i < IPREASS_NHASH; i++)
 402                         TAILQ_INIT(&fragq->ipq[i]);
 403
 404                 callout_init_mp(&fragq->timeo_ch);
 405                 netmsg_init(&fragq->timeo_netmsg, NULL, &netisr_adone_rport,
 406                     MSGF_PRIORITY, ipfrag_timeo_dispatch);
 407                 netmsg_init(&fragq->drain_netmsg, NULL, &netisr_adone_rport,
 408                     MSGF_PRIORITY, ipfrag_drain_dispatch);
 409         }
 410
 411         netisr_register(NETISR_IP, ip_input_handler, ip_hashfn);
 412         netisr_register_hashcheck(NETISR_IP, ip_hashcheck);
 413
 414         for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
 415                 fragq = &ipfrag_queue_pcpu[cpu];
 416                 callout_reset_bycpu(&fragq->timeo_ch, IPFRAG_TIMEO,
 417                     ipfrag_timeo, NULL, cpu);
 418         }
 419 }
 420
 421 /* Do transport protocol processing. */
 422 static void
 423 transport_processing_oncpu(struct mbuf *m, int hlen, struct ip *ip)
 424 {
 425         const struct protosw *pr = &inetsw[ip_protox[ip->ip_p]];
 426
 427         /*
 428          * Switch out to protocol's input routine.
 429          */
 430         PR_GET_MPLOCK(pr);
 431         pr->pr_input(&m, &hlen, ip->ip_p);
 432         PR_REL_MPLOCK(pr);
 433 }
 434
 435 static void
 436 transport_processing_handler(netmsg_t msg)
 437 {
 438         struct netmsg_packet *pmsg = &msg->packet;
 439         struct ip *ip;
 440         int hlen;
 441
 442         ip = mtod(pmsg->nm_packet, struct ip *);
 443         hlen = pmsg->base.lmsg.u.ms_result;
 444
 445         transport_processing_oncpu(pmsg->nm_packet, hlen, ip);
 446         /* msg was embedded in the mbuf, do not reply! */
 447 }
 448
 449 static void
 450 ip_input_handler(netmsg_t msg)
 451 {
 452         ip_input(msg->packet.nm_packet);
 453         /* msg was embedded in the mbuf, do not reply! */
 454 }
 455
 456 /*
 457  * IP input routine.  Checksum and byte swap header.  If fragmented
 458  * try to reassemble.  Process options.  Pass to next level.
 459  */
 460 void
 461 ip_input(struct mbuf *m)
 462 {
 463         struct ip *ip;
 464         struct in_ifaddr *ia = NULL;
 465         struct in_ifaddr_container *iac;
 466         int hlen, checkif;
 467         u_short sum;
 468         struct in_addr pkt_dst;
 469         boolean_t using_srcrt = FALSE;          /* forward (by PFIL_HOOKS) */
 470         struct in_addr odst;                    /* original dst address(NAT) */
 471         struct m_tag *mtag;
 472         struct sockaddr_in *next_hop = NULL;
 473         lwkt_port_t port;
 474 #ifdef FAST_IPSEC
 475         struct tdb_ident *tdbi;
 476         struct secpolicy *sp;
 477         int error;
 478 #endif
 479
 480         ASSERT_NETISR_NCPUS(mycpuid);
 481         M_ASSERTPKTHDR(m);
 482
 483         /* length checks already done in ip_hashfn() */
 484         KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf"));
 485
 486         /*
 487          * This routine is called from numerous places which may not have
 488          * characterized the packet.
 489          */
 490         ip = mtod(m, struct ip *);
 491         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 492             (ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK))) {
 493                 /*
 494                  * Force hash recalculation for fragments and multicast
 495                  * packets; hardware may not do it correctly.
 496                  * XXX add flag to indicate the hash is from hardware
 497                  */
 498                 m->m_flags &= ~M_HASH;
 499         }
 500         if ((m->m_flags & M_HASH) == 0) {
 501                 ip_hashfn(&m, 0);
 502                 if (m == NULL)
 503                         return;
 504                 KKASSERT(m->m_flags & M_HASH);
 505
 506                 if (&curthread->td_msgport !=
 507                     netisr_hashport(m->m_pkthdr.hash)) {
 508                         netisr_queue(NETISR_IP, m);
 509                         /* Requeued to other netisr msgport; done */
 510                         return;
 511                 }
 512
 513                 /* mbuf could have been changed */
 514                 ip = mtod(m, struct ip *);
 515         }
 516
 517         /*
 518          * Pull out certain tags
 519          */
 520         if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
 521                 /* Next hop */
 522                 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 523                 KKASSERT(mtag != NULL);
 524                 next_hop = m_tag_data(mtag);
 525         }
 526
 527         if (m->m_pkthdr.fw_flags &
 528             (DUMMYNET_MBUF_TAGGED | IPFW_MBUF_CONTINUE)) {
 529                 /*
 530                  * - Dummynet already filtered this packet.
 531                  * - This packet was processed by ipfw on another
 532                  *   cpu, and the rest of the ipfw processing should
 533                  *   be carried out on this cpu.
 534                  */
 535                 ip = mtod(m, struct ip *);
 536                 ip->ip_len = ntohs(ip->ip_len);
 537                 ip->ip_off = ntohs(ip->ip_off);
 538                 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 539                 goto iphack;
 540         }
 541
 542         ipstat.ips_total++;
 543
 544         if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
 545                 ipstat.ips_badvers++;
 546                 goto bad;
 547         }
 548
 549         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 550         /* length checks already done in ip_hashfn() */
 551         KASSERT(hlen >= sizeof(struct ip), ("IP header len too small"));
 552         KASSERT(m->m_len >= hlen, ("complete IP header not in one mbuf"));
 553
 554         /* 127/8 must not appear on wire - RFC1122 */
 555         if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
 556             (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
 557                 if (!(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) {
 558                         ipstat.ips_badaddr++;
 559                         goto bad;
 560                 }
 561         }
 562
 563         if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
 564                 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
 565         } else {
 566                 if (hlen == sizeof(struct ip))
 567                         sum = in_cksum_hdr(ip);
 568                 else
 569                         sum = in_cksum(m, hlen);
 570         }
 571         if (sum != 0) {
 572                 ipstat.ips_badsum++;
 573                 goto bad;
 574         }
 575
 576 #ifdef ALTQ
 577         if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
 578                 /* packet is dropped by traffic conditioner */
 579                 return;
 580         }
 581 #endif
 582         /*
 583          * Convert fields to host representation.
 584          */
 585         ip->ip_len = ntohs(ip->ip_len);
 586         ip->ip_off = ntohs(ip->ip_off);
 587
 588         /* length checks already done in ip_hashfn() */
 589         KASSERT(ip->ip_len >= hlen, ("total length less then header length"));
 590         KASSERT(m->m_pkthdr.len >= ip->ip_len, ("mbuf too short"));
 591
 592         /*
 593          * Trim mbufs if longer than the IP header would have us expect.
 594          */
 595         if (m->m_pkthdr.len > ip->ip_len) {
 596                 if (m->m_len == m->m_pkthdr.len) {
 597                         m->m_len = ip->ip_len;
 598                         m->m_pkthdr.len = ip->ip_len;
 599                 } else {
 600                         m_adj(m, ip->ip_len - m->m_pkthdr.len);
 601                 }
 602         }
 603 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
 604         /*
 605          * Bypass packet filtering for packets from a tunnel (gif).
 606          */
 607         if (ipsec_gethist(m, NULL))
 608                 goto pass;
 609 #endif
 610
 611         /*
 612          * IpHack's section.
 613          * Right now when no processing on packet has done
 614          * and it is still fresh out of network we do our black
 615          * deals with it.
 616          * - Firewall: deny/allow/divert
 617          * - Xlate: translate packet's addr/port (NAT).
 618          * - Pipe: pass pkt through dummynet.
 619          * - Wrap: fake packet's addr/port <unimpl.>
 620          * - Encapsulate: put it in another IP and send out. <unimp.>
 621          */
 622
 623 iphack:
 624         /*
 625          * If we've been forwarded from the output side, then
 626          * skip the firewall a second time
 627          */
 628         if (next_hop != NULL)
 629                 goto ours;
 630
 631         /* No pfil hooks */
 632         if (!pfil_has_hooks(&inet_pfil_hook)) {
 633                 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
 634                         /*
 635                          * Strip dummynet tags from stranded packets
 636                          */
 637                         mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
 638                         KKASSERT(mtag != NULL);
 639                         m_tag_delete(m, mtag);
 640                         m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
 641                 }
 642                 goto pass;
 643         }
 644
 645         /*
 646          * Run through list of hooks for input packets.
 647          *
 648          * NOTE!  If the packet is rewritten pf/ipfw/whoever must
 649          *        clear M_HASH.
 650          */
 651         odst = ip->ip_dst;
 652         if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN))
 653                 return;
 654         if (m == NULL)  /* consumed by filter */
 655                 return;
 656         ip = mtod(m, struct ip *);
 657         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 658         using_srcrt = (odst.s_addr != ip->ip_dst.s_addr);
 659
 660         if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
 661                 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 662                 KKASSERT(mtag != NULL);
 663                 next_hop = m_tag_data(mtag);
 664         }
 665         if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
 666                 ip_dn_queue(m);
 667                 return;
 668         }
 669         if (m->m_pkthdr.fw_flags & FW_MBUF_REDISPATCH)
 670                 m->m_pkthdr.fw_flags &= ~FW_MBUF_REDISPATCH;
 671         if (m->m_pkthdr.fw_flags & IPFW_MBUF_CONTINUE) {
 672                 /* ipfw was disabled/unloaded. */
 673                 goto bad;
 674         }
 675 pass:
 676         /*
 677          * Process options and, if not destined for us,
 678          * ship it on.  ip_dooptions returns 1 when an
 679          * error was detected (causing an icmp message
 680          * to be sent and the original packet to be freed).
 681          */
 682         if (hlen > sizeof(struct ip) && ip_dooptions(m, 0, next_hop))
 683                 return;
 684
 685         /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
 686          * matter if it is destined to another node, or whether it is
 687          * a multicast one, RSVP wants it! and prevents it from being forwarded
 688          * anywhere else. Also checks if the rsvp daemon is running before
 689          * grabbing the packet.
 690          */
 691         if (rsvp_on && ip->ip_p == IPPROTO_RSVP)
 692                 goto ours;
 693
 694         /*
 695          * Check our list of addresses, to see if the packet is for us.
 696          * If we don't have any addresses, assume any unicast packet
 697          * we receive might be for us (and let the upper layers deal
 698          * with it).
 699          */
 700         if (TAILQ_EMPTY(&in_ifaddrheads[mycpuid]) &&
 701             !(m->m_flags & (M_MCAST | M_BCAST)))
 702                 goto ours;
 703
 704         /*
 705          * Cache the destination address of the packet; this may be
 706          * changed by use of 'ipfw fwd'.
 707          */
 708         pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
 709
 710         /*
 711          * Enable a consistency check between the destination address
 712          * and the arrival interface for a unicast packet (the RFC 1122
 713          * strong ES model) if IP forwarding is disabled and the packet
 714          * is not locally generated and the packet is not subject to
 715          * 'ipfw fwd'.
 716          *
 717          * XXX - Checking also should be disabled if the destination
 718          * address is ipnat'ed to a different interface.
 719          *
 720          * XXX - Checking is incompatible with IP aliases added
 721          * to the loopback interface instead of the interface where
 722          * the packets are received.
 723          */
 724         checkif = ip_checkinterface &&
 725                   !ipforwarding &&
 726                   m->m_pkthdr.rcvif != NULL &&
 727                   !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) &&
 728                   next_hop == NULL;
 729
 730         /*
 731          * Check for exact addresses in the hash bucket.
 732          */
 733         LIST_FOREACH(iac, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
 734                 ia = iac->ia;
 735
 736                 /*
 737                  * If the address matches, verify that the packet
 738                  * arrived via the correct interface if checking is
 739                  * enabled.
 740                  */
 741                 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
 742                     (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
 743                         goto ours;
 744         }
 745         ia = NULL;
 746
 747         /*
 748          * Check for broadcast addresses.
 749          *
 750          * Only accept broadcast packets that arrive via the matching
 751          * interface.  Reception of forwarded directed broadcasts would
 752          * be handled via ip_forward() and ether_output() with the loopback
 753          * into the stack for SIMPLEX interfaces handled by ether_output().
 754          */
 755         if (m->m_pkthdr.rcvif != NULL &&
 756             m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
 757                 struct ifaddr_container *ifac;
 758
 759                 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid],
 760                               ifa_link) {
 761                         struct ifaddr *ifa = ifac->ifa;
 762
 763                         if (ifa->ifa_addr == NULL) /* shutdown/startup race */
 764                                 continue;
 765                         if (ifa->ifa_addr->sa_family != AF_INET)
 766                                 continue;
 767                         ia = ifatoia(ifa);
 768                         if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
 769                                                                 pkt_dst.s_addr)
 770                                 goto ours;
 771                         if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
 772                                 goto ours;
 773 #ifdef BOOTP_COMPAT
 774                         if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
 775                                 goto ours;
 776 #endif
 777                 }
 778         }
 779         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 780                 struct in_multi *inm;
 781
 782                 if (ip_mrouter != NULL) {
 783                         /* XXX Multicast routing is not MPSAFE yet */
 784                         get_mplock();
 785
 786                         /*
 787                          * If we are acting as a multicast router, all
 788                          * incoming multicast packets are passed to the
 789                          * kernel-level multicast forwarding function.
 790                          * The packet is returned (relatively) intact; if
 791                          * ip_mforward() returns a non-zero value, the packet
 792                          * must be discarded, else it may be accepted below.
 793                          */
 794                         if (ip_mforward != NULL &&
 795                             ip_mforward(ip, m->m_pkthdr.rcvif, m, NULL) != 0) {
 796                                 rel_mplock();
 797                                 ipstat.ips_cantforward++;
 798                                 m_freem(m);
 799                                 return;
 800                         }
 801
 802                         rel_mplock();
 803
 804                         /*
 805                          * The process-level routing daemon needs to receive
 806                          * all multicast IGMP packets, whether or not this
 807                          * host belongs to their destination groups.
 808                          */
 809                         if (ip->ip_p == IPPROTO_IGMP)
 810                                 goto ours;
 811                         ipstat.ips_forward++;
 812                 }
 813                 /*
 814                  * See if we belong to the destination multicast group on the
 815                  * arrival interface.
 816                  */
 817                 inm = IN_LOOKUP_MULTI(&ip->ip_dst, m->m_pkthdr.rcvif);
 818                 if (inm == NULL) {
 819                         ipstat.ips_notmember++;
 820                         m_freem(m);
 821                         return;
 822                 }
 823                 goto ours;
 824         }
 825         if (ip->ip_dst.s_addr == INADDR_BROADCAST)
 826                 goto ours;
 827         if (ip->ip_dst.s_addr == INADDR_ANY)
 828                 goto ours;
 829
 830         /*
 831          * FAITH(Firewall Aided Internet Translator)
 832          */
 833         if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
 834                 if (ip_keepfaith) {
 835                         if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
 836                                 goto ours;
 837                 }
 838                 m_freem(m);
 839                 return;
 840         }
 841
 842         /*
 843          * Not for us; forward if possible and desirable.
 844          */
 845         if (!ipforwarding) {
 846                 ipstat.ips_cantforward++;
 847                 m_freem(m);
 848         } else {
 849 #ifdef IPSEC
 850                 /*
 851                  * Enforce inbound IPsec SPD.
 852                  */
 853                 if (ipsec4_in_reject(m, NULL)) {
 854                         ipsecstat.in_polvio++;
 855                         goto bad;
 856                 }
 857 #endif
 858 #ifdef FAST_IPSEC
 859                 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
 860                 crit_enter();
 861                 if (mtag != NULL) {
 862                         tdbi = (struct tdb_ident *)m_tag_data(mtag);
 863                         sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
 864                 } else {
 865                         sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
 866                                                    IP_FORWARDING, &error);
 867                 }
 868                 if (sp == NULL) {       /* NB: can happen if error */
 869                         crit_exit();
 870                         /*XXX error stat???*/
 871                         DPRINTF(("ip_input: no SP for forwarding\n"));  /*XXX*/
 872                         goto bad;
 873                 }
 874
 875                 /*
 876                  * Check security policy against packet attributes.
 877                  */
 878                 error = ipsec_in_reject(sp, m);
 879                 KEY_FREESP(&sp);
 880                 crit_exit();
 881                 if (error) {
 882                         ipstat.ips_cantforward++;
 883                         goto bad;
 884                 }
 885 #endif
 886                 ip_forward(m, using_srcrt, next_hop);
 887         }
 888         return;
 889
 890 ours:
 891
 892         /*
 893          * IPSTEALTH: Process non-routing options only
 894          * if the packet is destined for us.
 895          */
 896         if (ipstealth &&
 897             hlen > sizeof(struct ip) &&
 898             ip_dooptions(m, 1, next_hop))
 899                 return;
 900
 901         /* Count the packet in the ip address stats */
 902         if (ia != NULL) {
 903                 IFA_STAT_INC(&ia->ia_ifa, ipackets, 1);
 904                 IFA_STAT_INC(&ia->ia_ifa, ibytes, m->m_pkthdr.len);
 905         }
 906
 907         /*
 908          * If offset or IP_MF are set, must reassemble.
 909          * Otherwise, nothing need be done.
 910          * (We could look in the reassembly queue to see
 911          * if the packet was previously fragmented,
 912          * but it's not worth the time; just let them time out.)
 913          */
 914         if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
 915                 /*
 916                  * Attempt reassembly; if it succeeds, proceed.  ip_reass()
 917                  * will return a different mbuf.
 918                  *
 919                  * NOTE: ip_reass() returns m with M_HASH cleared to force
 920                  *       us to recharacterize the packet.
 921                  */
 922                 m = ip_reass(m);
 923                 if (m == NULL)
 924                         return;
 925                 ip = mtod(m, struct ip *);
 926
 927                 /* Get the header length of the reassembled packet */
 928                 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 929         } else {
 930                 ip->ip_len -= hlen;
 931         }
 932
 933 #ifdef IPSEC
 934         /*
 935          * enforce IPsec policy checking if we are seeing last header.
 936          * note that we do not visit this with protocols with pcb layer
 937          * code - like udp/tcp/raw ip.
 938          */
 939         if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) &&
 940             ipsec4_in_reject(m, NULL)) {
 941                 ipsecstat.in_polvio++;
 942                 goto bad;
 943         }
 944 #endif
 945 #ifdef FAST_IPSEC
 946         /*
 947          * enforce IPsec policy checking if we are seeing last header.
 948          * note that we do not visit this with protocols with pcb layer
 949          * code - like udp/tcp/raw ip.
 950          */
 951         if (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) {
 952                 /*
 953                  * Check if the packet has already had IPsec processing
 954                  * done.  If so, then just pass it along.  This tag gets
 955                  * set during AH, ESP, etc. input handling, before the
 956                  * packet is returned to the ip input queue for delivery.
 957                  */
 958                 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
 959                 crit_enter();
 960                 if (mtag != NULL) {
 961                         tdbi = (struct tdb_ident *)m_tag_data(mtag);
 962                         sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
 963                 } else {
 964                         sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
 965                                                    IP_FORWARDING, &error);
 966                 }
 967                 if (sp != NULL) {
 968                         /*
 969                          * Check security policy against packet attributes.
 970                          */
 971                         error = ipsec_in_reject(sp, m);
 972                         KEY_FREESP(&sp);
 973                 } else {
 974                         /* XXX error stat??? */
 975                         error = EINVAL;
 976 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
 977                         crit_exit();
 978                         goto bad;
 979                 }
 980                 crit_exit();
 981                 if (error)
 982                         goto bad;
 983         }
 984 #endif /* FAST_IPSEC */
 985
 986         /*
 987          * We must forward the packet to the correct protocol thread if
 988          * we are not already in it.
 989          *
 990          * NOTE: ip_len is now in host form.  ip_len is not adjusted
 991          *       further for protocol processing, instead we pass hlen
 992          *       to the protosw and let it deal with it.
 993          */
 994         ipstat.ips_delivered++;
 995
 996         if ((m->m_flags & M_HASH) == 0) {
 997 #ifdef RSS_DEBUG
 998                 atomic_add_long(&ip_rehash_count, 1);
 999 #endif
1000                 ip->ip_len = htons(ip->ip_len + hlen);
1001                 ip->ip_off = htons(ip->ip_off);
1002
1003                 ip_hashfn(&m, 0);
1004                 if (m == NULL)
1005                         return;
1006
1007                 ip = mtod(m, struct ip *);
1008                 ip->ip_len = ntohs(ip->ip_len) - hlen;
1009                 ip->ip_off = ntohs(ip->ip_off);
1010                 KKASSERT(m->m_flags & M_HASH);
1011         }
1012         port = netisr_hashport(m->m_pkthdr.hash);
1013
1014         if (port != &curthread->td_msgport) {
1015                 struct netmsg_packet *pmsg;
1016
1017 #ifdef RSS_DEBUG
1018                 atomic_add_long(&ip_dispatch_slow, 1);
1019 #endif
1020
1021                 pmsg = &m->m_hdr.mh_netmsg;
1022                 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport,
1023                             0, transport_processing_handler);
1024                 pmsg->nm_packet = m;
1025                 pmsg->base.lmsg.u.ms_result = hlen;
1026                 lwkt_sendmsg(port, &pmsg->base.lmsg);
1027         } else {
1028 #ifdef RSS_DEBUG
1029                 atomic_add_long(&ip_dispatch_fast, 1);
1030 #endif
1031                 transport_processing_oncpu(m, hlen, ip);
1032         }
1033         return;
1034
1035 bad:
1036         m_freem(m);
1037 }
1038
1039 /*
1040  * Take incoming datagram fragment and try to reassemble it into
1041  * whole datagram.  If a chain for reassembly of this datagram already
1042  * exists, then it is given as fp; otherwise have to make a chain.
1043  */
1044 struct mbuf *
1045 ip_reass(struct mbuf *m)
1046 {
1047         struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[mycpuid];
1048         struct ip *ip = mtod(m, struct ip *);
1049         struct mbuf *p = NULL, *q, *nq;
1050         struct mbuf *n;
1051         struct ipq *fp = NULL;
1052         struct ipqhead *head;
1053         int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1054         int i, next;
1055         u_short sum;
1056
1057         /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */
1058         if (maxnipq == 0 || maxfragsperpacket == 0) {
1059                 ipstat.ips_fragments++;
1060                 ipstat.ips_fragdropped++;
1061                 m_freem(m);
1062                 return NULL;
1063         }
1064
1065         sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
1066         /*
1067          * Look for queue of fragments of this datagram.
1068          */
1069         head = &fragq->ipq[sum];
1070         TAILQ_FOREACH(fp, head, ipq_list) {
1071                 if (ip->ip_id == fp->ipq_id &&
1072                     ip->ip_src.s_addr == fp->ipq_src.s_addr &&
1073                     ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
1074                     ip->ip_p == fp->ipq_p)
1075                         goto found;
1076         }
1077
1078         fp = NULL;
1079
1080         /*
1081          * Enforce upper bound on number of fragmented packets
1082          * for which we attempt reassembly;
1083          * If maxnipq is -1, accept all fragments without limitation.
1084          */
1085         if (fragq->nipq > maxnipq && maxnipq > 0) {
1086                 /*
1087                  * drop something from the tail of the current queue
1088                  * before proceeding further
1089                  */
1090                 struct ipq *q = TAILQ_LAST(head, ipqhead);
1091                 if (q == NULL) {
1092                         /*
1093                          * The current queue is empty,
1094                          * so drop from one of the others.
1095                          */
1096                         for (i = 0; i < IPREASS_NHASH; i++) {
1097                                 struct ipq *r = TAILQ_LAST(&fragq->ipq[i],
1098                                     ipqhead);
1099                                 if (r) {
1100                                         ipstat.ips_fragtimeout += r->ipq_nfrags;
1101                                         ip_freef(fragq, &fragq->ipq[i], r);
1102                                         break;
1103                                 }
1104                         }
1105                 } else {
1106                         ipstat.ips_fragtimeout += q->ipq_nfrags;
1107                         ip_freef(fragq, head, q);
1108                 }
1109         }
1110 found:
1111         /*
1112          * Adjust ip_len to not reflect header,
1113          * convert offset of this to bytes.
1114          */
1115         ip->ip_len -= hlen;
1116         if (ip->ip_off & IP_MF) {
1117                 /*
1118                  * Make sure that fragments have a data length
1119                  * that's a non-zero multiple of 8 bytes.
1120                  */
1121                 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
1122                         ipstat.ips_toosmall++; /* XXX */
1123                         m_freem(m);
1124                         goto done;
1125                 }
1126                 m->m_flags |= M_FRAG;
1127         } else {
1128                 m->m_flags &= ~M_FRAG;
1129         }
1130         ip->ip_off <<= 3;
1131
1132         ipstat.ips_fragments++;
1133         m->m_pkthdr.header = ip;
1134
1135         /*
1136          * If the hardware has not done csum over this fragment
1137          * then csum_data is not valid at all.
1138          */
1139         if ((m->m_pkthdr.csum_flags & (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID))
1140             == (CSUM_FRAG_NOT_CHECKED | CSUM_DATA_VALID)) {
1141                 m->m_pkthdr.csum_data = 0;
1142                 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
1143         }
1144
1145         /*
1146          * Presence of header sizes in mbufs
1147          * would confuse code below.
1148          */
1149         m->m_data += hlen;
1150         m->m_len -= hlen;
1151
1152         /*
1153          * If first fragment to arrive, create a reassembly queue.
1154          */
1155         if (fp == NULL) {
1156                 if ((fp = mpipe_alloc_nowait(&ipq_mpipe)) == NULL)
1157                         goto dropfrag;
1158                 TAILQ_INSERT_HEAD(head, fp, ipq_list);
1159                 fragq->nipq++;
1160                 fp->ipq_nfrags = 1;
1161                 fp->ipq_ttl = IPFRAGTTL;
1162                 fp->ipq_p = ip->ip_p;
1163                 fp->ipq_id = ip->ip_id;
1164                 fp->ipq_src = ip->ip_src;
1165                 fp->ipq_dst = ip->ip_dst;
1166                 fp->ipq_frags = m;
1167                 m->m_nextpkt = NULL;
1168                 goto inserted;
1169         }
1170         fp->ipq_nfrags++;
1171
1172 #define GETIP(m)        ((struct ip*)((m)->m_pkthdr.header))
1173
1174         /*
1175          * Find a segment which begins after this one does.
1176          */
1177         for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1178                 if (GETIP(q)->ip_off > ip->ip_off)
1179                         break;
1180         }
1181
1182         /*
1183          * If there is a preceding segment, it may provide some of
1184          * our data already.  If so, drop the data from the incoming
1185          * segment.  If it provides all of our data, drop us, otherwise
1186          * stick new segment in the proper place.
1187          *
1188          * If some of the data is dropped from the the preceding
1189          * segment, then it's checksum is invalidated.
1190          */
1191         if (p) {
1192                 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1193                 if (i > 0) {
1194                         if (i >= ip->ip_len)
1195                                 goto dropfrag;
1196                         m_adj(m, i);
1197                         m->m_pkthdr.csum_flags = 0;
1198                         ip->ip_off += i;
1199                         ip->ip_len -= i;
1200                 }
1201                 m->m_nextpkt = p->m_nextpkt;
1202                 p->m_nextpkt = m;
1203         } else {
1204                 m->m_nextpkt = fp->ipq_frags;
1205                 fp->ipq_frags = m;
1206         }
1207
1208         /*
1209          * While we overlap succeeding segments trim them or,
1210          * if they are completely covered, dequeue them.
1211          */
1212         for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1213              q = nq) {
1214                 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1215                 if (i < GETIP(q)->ip_len) {
1216                         GETIP(q)->ip_len -= i;
1217                         GETIP(q)->ip_off += i;
1218                         m_adj(q, i);
1219                         q->m_pkthdr.csum_flags = 0;
1220                         break;
1221                 }
1222                 nq = q->m_nextpkt;
1223                 m->m_nextpkt = nq;
1224                 ipstat.ips_fragdropped++;
1225                 fp->ipq_nfrags--;
1226                 q->m_nextpkt = NULL;
1227                 m_freem(q);
1228         }
1229
1230 inserted:
1231         /*
1232          * Check for complete reassembly and perform frag per packet
1233          * limiting.
1234          *
1235          * Frag limiting is performed here so that the nth frag has
1236          * a chance to complete the packet before we drop the packet.
1237          * As a result, n+1 frags are actually allowed per packet, but
1238          * only n will ever be stored. (n = maxfragsperpacket.)
1239          *
1240          */
1241         next = 0;
1242         for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1243                 if (GETIP(q)->ip_off != next) {
1244                         if (fp->ipq_nfrags > maxfragsperpacket) {
1245                                 ipstat.ips_fragdropped += fp->ipq_nfrags;
1246                                 ip_freef(fragq, head, fp);
1247                         }
1248                         goto done;
1249                 }
1250                 next += GETIP(q)->ip_len;
1251         }
1252         /* Make sure the last packet didn't have the IP_MF flag */
1253         if (p->m_flags & M_FRAG) {
1254                 if (fp->ipq_nfrags > maxfragsperpacket) {
1255                         ipstat.ips_fragdropped += fp->ipq_nfrags;
1256                         ip_freef(fragq, head, fp);
1257                 }
1258                 goto done;
1259         }
1260
1261         /*
1262          * Reassembly is complete.  Make sure the packet is a sane size.
1263          */
1264         q = fp->ipq_frags;
1265         ip = GETIP(q);
1266         if (next + (IP_VHL_HL(ip->ip_vhl) << 2) > IP_MAXPACKET) {
1267                 ipstat.ips_toolong++;
1268                 ipstat.ips_fragdropped += fp->ipq_nfrags;
1269                 ip_freef(fragq, head, fp);
1270                 goto done;
1271         }
1272
1273         /*
1274          * Concatenate fragments.
1275          */
1276         m = q;
1277         n = m->m_next;
1278         m->m_next = NULL;
1279         m_cat(m, n);
1280         nq = q->m_nextpkt;
1281         q->m_nextpkt = NULL;
1282         for (q = nq; q != NULL; q = nq) {
1283                 nq = q->m_nextpkt;
1284                 q->m_nextpkt = NULL;
1285                 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1286                 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1287                 m_cat(m, q);
1288         }
1289
1290         /*
1291          * Clean up the 1's complement checksum.  Carry over 16 bits must
1292          * be added back.  This assumes no more then 65535 packet fragments
1293          * were reassembled.  A second carry can also occur (but not a third).
1294          */
1295         m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) +
1296                                 (m->m_pkthdr.csum_data >> 16);
1297         if (m->m_pkthdr.csum_data > 0xFFFF)
1298                 m->m_pkthdr.csum_data -= 0xFFFF;
1299
1300         /*
1301          * Create header for new ip packet by
1302          * modifying header of first packet;
1303          * dequeue and discard fragment reassembly header.
1304          * Make header visible.
1305          */
1306         ip->ip_len = next;
1307         ip->ip_src = fp->ipq_src;
1308         ip->ip_dst = fp->ipq_dst;
1309         TAILQ_REMOVE(head, fp, ipq_list);
1310         fragq->nipq--;
1311         mpipe_free(&ipq_mpipe, fp);
1312         m->m_len += (IP_VHL_HL(ip->ip_vhl) << 2);
1313         m->m_data -= (IP_VHL_HL(ip->ip_vhl) << 2);
1314         /* some debugging cruft by sklower, below, will go away soon */
1315         if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
1316                 int plen = 0;
1317
1318                 for (n = m; n; n = n->m_next)
1319                         plen += n->m_len;
1320                 m->m_pkthdr.len = plen;
1321         }
1322
1323         /*
1324          * Reassembly complete, return the next protocol.
1325          *
1326          * Be sure to clear M_HASH to force the packet
1327          * to be re-characterized.
1328          *
1329          * Clear M_FRAG, we are no longer a fragment.
1330          */
1331         m->m_flags &= ~(M_HASH | M_FRAG);
1332
1333         ipstat.ips_reassembled++;
1334         return (m);
1335
1336 dropfrag:
1337         ipstat.ips_fragdropped++;
1338         if (fp != NULL)
1339                 fp->ipq_nfrags--;
1340         m_freem(m);
1341 done:
1342         return (NULL);
1343
1344 #undef GETIP
1345 }
1346
1347 /*
1348  * Free a fragment reassembly header and all
1349  * associated datagrams.
1350  */
1351 static void
1352 ip_freef(struct ipfrag_queue *fragq, struct ipqhead *fhp, struct ipq *fp)
1353 {
1354         struct mbuf *q;
1355
1356         /*
1357          * Remove first to protect against blocking
1358          */
1359         TAILQ_REMOVE(fhp, fp, ipq_list);
1360
1361         /*
1362          * Clean out at our leisure
1363          */
1364         while (fp->ipq_frags) {
1365                 q = fp->ipq_frags;
1366                 fp->ipq_frags = q->m_nextpkt;
1367                 q->m_nextpkt = NULL;
1368                 m_freem(q);
1369         }
1370         mpipe_free(&ipq_mpipe, fp);
1371         fragq->nipq--;
1372 }
1373
1374 /*
1375  * If a timer expires on a reassembly queue, discard it.
1376  */
1377 static void
1378 ipfrag_timeo_dispatch(netmsg_t nmsg)
1379 {
1380         struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[mycpuid];
1381         struct ipq *fp, *fp_temp;
1382         struct ipqhead *head;
1383         int i;
1384
1385         crit_enter();
1386         netisr_replymsg(&nmsg->base, 0);  /* reply ASAP */
1387         crit_exit();
1388
1389         if (fragq->nipq == 0)
1390                 goto done;
1391
1392         for (i = 0; i < IPREASS_NHASH; i++) {
1393                 head = &fragq->ipq[i];
1394                 TAILQ_FOREACH_MUTABLE(fp, head, ipq_list, fp_temp) {
1395                         if (--fp->ipq_ttl == 0) {
1396                                 ipstat.ips_fragtimeout += fp->ipq_nfrags;
1397                                 ip_freef(fragq, head, fp);
1398                         }
1399                 }
1400         }
1401         /*
1402          * If we are over the maximum number of fragments
1403          * (due to the limit being lowered), drain off
1404          * enough to get down to the new limit.
1405          */
1406         if (maxnipq >= 0 && fragq->nipq > maxnipq) {
1407                 for (i = 0; i < IPREASS_NHASH; i++) {
1408                         head = &fragq->ipq[i];
1409                         while (fragq->nipq > maxnipq && !TAILQ_EMPTY(head)) {
1410                                 ipstat.ips_fragdropped +=
1411                                     TAILQ_FIRST(head)->ipq_nfrags;
1412                                 ip_freef(fragq, head, TAILQ_FIRST(head));
1413                         }
1414                 }
1415         }
1416 done:
1417         callout_reset(&fragq->timeo_ch, IPFRAG_TIMEO, ipfrag_timeo, NULL);
1418 }
1419
1420 static void
1421 ipfrag_timeo(void *dummy __unused)
1422 {
1423         struct netmsg_base *msg = &ipfrag_queue_pcpu[mycpuid].timeo_netmsg;
1424
1425         crit_enter();
1426         if (msg->lmsg.ms_flags & MSGF_DONE)
1427                 netisr_sendmsg_oncpu(msg);
1428         crit_exit();
1429 }
1430
1431 /*
1432  * Drain off all datagram fragments.
1433  */
1434 static void
1435 ipfrag_drain_oncpu(struct ipfrag_queue *fragq)
1436 {
1437         struct ipqhead *head;
1438         int i;
1439
1440         for (i = 0; i < IPREASS_NHASH; i++) {
1441                 head = &fragq->ipq[i];
1442                 while (!TAILQ_EMPTY(head)) {
1443                         ipstat.ips_fragdropped += TAILQ_FIRST(head)->ipq_nfrags;
1444                         ip_freef(fragq, head, TAILQ_FIRST(head));
1445                 }
1446         }
1447 }
1448
1449 static void
1450 ipfrag_drain_dispatch(netmsg_t nmsg)
1451 {
1452         struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[mycpuid];
1453
1454         crit_enter();
1455         lwkt_replymsg(&nmsg->lmsg, 0);  /* reply ASAP */
1456         crit_exit();
1457
1458         ipfrag_drain_oncpu(fragq);
1459         fragq->draining = 0;
1460 }
1461
1462 static void
1463 ipfrag_drain_ipi(void *arg __unused)
1464 {
1465         int cpu = mycpuid;
1466         struct lwkt_msg *msg = &ipfrag_queue_pcpu[cpu].drain_netmsg.lmsg;
1467
1468         crit_enter();
1469         if (msg->ms_flags & MSGF_DONE)
1470                 lwkt_sendmsg_oncpu(netisr_cpuport(cpu), msg);
1471         crit_exit();
1472 }
1473
1474 static void
1475 ipfrag_drain(void)
1476 {
1477         cpumask_t mask;
1478         int cpu;
1479
1480         CPUMASK_ASSBMASK(mask, netisr_ncpus);
1481         CPUMASK_ANDMASK(mask, smp_active_mask);
1482
1483         if (IN_NETISR_NCPUS(mycpuid)) {
1484                 ipfrag_drain_oncpu(&ipfrag_queue_pcpu[mycpuid]);
1485                 CPUMASK_NANDBIT(mask, mycpuid);
1486         }
1487
1488         for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
1489                 struct ipfrag_queue *fragq = &ipfrag_queue_pcpu[cpu];
1490
1491                 if (!CPUMASK_TESTBIT(mask, cpu))
1492                         continue;
1493
1494                 if (fragq->nipq == 0 || fragq->draining) {
1495                         /* No fragments or is draining; skip this cpu. */
1496                         CPUMASK_NANDBIT(mask, cpu);
1497                         continue;
1498                 }
1499                 fragq->draining = 1;
1500         }
1501
1502         if (CPUMASK_TESTNZERO(mask))
1503                 lwkt_send_ipiq_mask(mask, ipfrag_drain_ipi, NULL);
1504 }
1505
1506 void
1507 ip_drain(void)
1508 {
1509         ipfrag_drain();
1510         in_rtqdrain();
1511 }
1512
1513 /*
1514  * Do option processing on a datagram,
1515  * possibly discarding it if bad options are encountered,
1516  * or forwarding it if source-routed.
1517  * The pass argument is used when operating in the IPSTEALTH
1518  * mode to tell what options to process:
1519  * [LS]SRR (pass 0) or the others (pass 1).
1520  * The reason for as many as two passes is that when doing IPSTEALTH,
1521  * non-routing options should be processed only if the packet is for us.
1522  * Returns 1 if packet has been forwarded/freed,
1523  * 0 if the packet should be processed further.
1524  */
1525 static int
1526 ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
1527 {
1528         struct sockaddr_in ipaddr = { sizeof ipaddr, AF_INET };
1529         struct ip *ip = mtod(m, struct ip *);
1530         u_char *cp;
1531         struct in_ifaddr *ia;
1532         int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB;
1533         boolean_t forward = FALSE;
1534         struct in_addr *sin, dst;
1535         n_time ntime;
1536
1537         dst = ip->ip_dst;
1538         cp = (u_char *)(ip + 1);
1539         cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1540         for (; cnt > 0; cnt -= optlen, cp += optlen) {
1541                 opt = cp[IPOPT_OPTVAL];
1542                 if (opt == IPOPT_EOL)
1543                         break;
1544                 if (opt == IPOPT_NOP)
1545                         optlen = 1;
1546                 else {
1547                         if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1548                                 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1549                                 goto bad;
1550                         }
1551                         optlen = cp[IPOPT_OLEN];
1552                         if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1553                                 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1554                                 goto bad;
1555                         }
1556                 }
1557                 switch (opt) {
1558
1559                 default:
1560                         break;
1561
1562                 /*
1563                  * Source routing with record.
1564                  * Find interface with current destination address.
1565                  * If none on this machine then drop if strictly routed,
1566                  * or do nothing if loosely routed.
1567                  * Record interface address and bring up next address
1568                  * component.  If strictly routed make sure next
1569                  * address is on directly accessible net.
1570                  */
1571                 case IPOPT_LSRR:
1572                 case IPOPT_SSRR:
1573                         if (ipstealth && pass > 0)
1574                                 break;
1575                         if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1576                                 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1577                                 goto bad;
1578                         }
1579                         if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1580                                 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1581                                 goto bad;
1582                         }
1583                         ipaddr.sin_addr = ip->ip_dst;
1584                         ia = (struct in_ifaddr *)
1585                                 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1586                         if (ia == NULL) {
1587                                 if (opt == IPOPT_SSRR) {
1588                                         type = ICMP_UNREACH;
1589                                         code = ICMP_UNREACH_SRCFAIL;
1590                                         goto bad;
1591                                 }
1592                                 if (!ip_dosourceroute)
1593                                         goto nosourcerouting;
1594                                 /*
1595                                  * Loose routing, and not at next destination
1596                                  * yet; nothing to do except forward.
1597                                  */
1598                                 break;
1599                         }
1600                         off--;                  /* 0 origin */
1601                         if (off > optlen - (int)sizeof(struct in_addr)) {
1602                                 /*
1603                                  * End of source route.  Should be for us.
1604                                  */
1605                                 if (!ip_acceptsourceroute)
1606                                         goto nosourcerouting;
1607                                 save_rte(m, cp, ip->ip_src);
1608                                 break;
1609                         }
1610                         if (ipstealth)
1611                                 goto dropit;
1612                         if (!ip_dosourceroute) {
1613                                 if (ipforwarding) {
1614                                         char sbuf[INET_ADDRSTRLEN];
1615                                         char dbuf[INET_ADDRSTRLEN];
1616
1617                                         /*
1618                                          * Acting as a router, so generate ICMP
1619                                          */
1620 nosourcerouting:
1621                                         log(LOG_WARNING,
1622                                             "attempted source route from %s to %s\n",
1623                                             kinet_ntoa(ip->ip_src, sbuf),
1624                                             kinet_ntoa(ip->ip_dst, dbuf));
1625                                         type = ICMP_UNREACH;
1626                                         code = ICMP_UNREACH_SRCFAIL;
1627                                         goto bad;
1628                                 } else {
1629                                         /*
1630                                          * Not acting as a router,
1631                                          * so silently drop.
1632                                          */
1633 dropit:
1634                                         ipstat.ips_cantforward++;
1635                                         m_freem(m);
1636                                         return (1);
1637                                 }
1638                         }
1639
1640                         /*
1641                          * locate outgoing interface
1642                          */
1643                         memcpy(&ipaddr.sin_addr, cp + off,
1644                             sizeof ipaddr.sin_addr);
1645
1646                         if (opt == IPOPT_SSRR) {
1647 #define INA     struct in_ifaddr *
1648 #define SA      struct sockaddr *
1649                                 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr))
1650                                                                         == NULL)
1651                                         ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1652                         } else {
1653                                 ia = ip_rtaddr(ipaddr.sin_addr, NULL);
1654                         }
1655                         if (ia == NULL) {
1656                                 type = ICMP_UNREACH;
1657                                 code = ICMP_UNREACH_SRCFAIL;
1658                                 goto bad;
1659                         }
1660                         ip->ip_dst = ipaddr.sin_addr;
1661                         memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1662                             sizeof(struct in_addr));
1663                         cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1664                         /*
1665                          * Let ip_intr's mcast routing check handle mcast pkts
1666                          */
1667                         forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1668                         break;
1669
1670                 case IPOPT_RR:
1671                         if (ipstealth && pass == 0)
1672                                 break;
1673                         if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1674                                 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1675                                 goto bad;
1676                         }
1677                         if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1678                                 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1679                                 goto bad;
1680                         }
1681                         /*
1682                          * If no space remains, ignore.
1683                          */
1684                         off--;                  /* 0 origin */
1685                         if (off > optlen - (int)sizeof(struct in_addr))
1686                                 break;
1687                         memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1688                             sizeof ipaddr.sin_addr);
1689                         /*
1690                          * locate outgoing interface; if we're the destination,
1691                          * use the incoming interface (should be same).
1692                          */
1693                         if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL &&
1694                             (ia = ip_rtaddr(ipaddr.sin_addr, NULL)) == NULL) {
1695                                 type = ICMP_UNREACH;
1696                                 code = ICMP_UNREACH_HOST;
1697                                 goto bad;
1698                         }
1699                         memcpy(cp + off, &IA_SIN(ia)->sin_addr,
1700                             sizeof(struct in_addr));
1701                         cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1702                         break;
1703
1704                 case IPOPT_TS:
1705                         if (ipstealth && pass == 0)
1706                                 break;
1707                         code = cp - (u_char *)ip;
1708                         if (optlen < 4 || optlen > 40) {
1709                                 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1710                                 goto bad;
1711                         }
1712                         if ((off = cp[IPOPT_OFFSET]) < 5) {
1713                                 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1714                                 goto bad;
1715                         }
1716                         if (off > optlen - (int)sizeof(int32_t)) {
1717                                 cp[IPOPT_OFFSET + 1] += (1 << 4);
1718                                 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1719                                         code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1720                                         goto bad;
1721                                 }
1722                                 break;
1723                         }
1724                         off--;                          /* 0 origin */
1725                         sin = (struct in_addr *)(cp + off);
1726                         switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1727
1728                         case IPOPT_TS_TSONLY:
1729                                 break;
1730
1731                         case IPOPT_TS_TSANDADDR:
1732                                 if (off + sizeof(n_time) +
1733                                     sizeof(struct in_addr) > optlen) {
1734                                         code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1735                                         goto bad;
1736                                 }
1737                                 ipaddr.sin_addr = dst;
1738                                 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1739                                                             m->m_pkthdr.rcvif);
1740                                 if (ia == NULL)
1741                                         continue;
1742                                 memcpy(sin, &IA_SIN(ia)->sin_addr,
1743                                     sizeof(struct in_addr));
1744                                 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1745                                 off += sizeof(struct in_addr);
1746                                 break;
1747
1748                         case IPOPT_TS_PRESPEC:
1749                                 if (off + sizeof(n_time) +
1750                                     sizeof(struct in_addr) > optlen) {
1751                                         code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1752                                         goto bad;
1753                                 }
1754                                 memcpy(&ipaddr.sin_addr, sin,
1755                                     sizeof(struct in_addr));
1756                                 if (ifa_ifwithaddr((SA)&ipaddr) == NULL)
1757                                         continue;
1758                                 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1759                                 off += sizeof(struct in_addr);
1760                                 break;
1761
1762                         default:
1763                                 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1764                                 goto bad;
1765                         }
1766                         ntime = iptime();
1767                         memcpy(cp + off, &ntime, sizeof(n_time));
1768                         cp[IPOPT_OFFSET] += sizeof(n_time);
1769                 }
1770         }
1771         if (forward && ipforwarding) {
1772                 ip_forward(m, TRUE, next_hop);
1773                 return (1);
1774         }
1775         return (0);
1776 bad:
1777         icmp_error(m, type, code, 0, 0);
1778         ipstat.ips_badoptions++;
1779         return (1);
1780 }
1781
1782 /*
1783  * Given address of next destination (final or next hop),
1784  * return internet address info of interface to be used to get there.
1785  */
1786 struct in_ifaddr *
1787 ip_rtaddr(struct in_addr dst, struct route *ro0)
1788 {
1789         struct route sro, *ro;
1790         struct sockaddr_in *sin;
1791         struct in_ifaddr *ia;
1792
1793         if (ro0 != NULL) {
1794                 ro = ro0;
1795         } else {
1796                 bzero(&sro, sizeof(sro));
1797                 ro = &sro;
1798         }
1799
1800         sin = (struct sockaddr_in *)&ro->ro_dst;
1801
1802         if (ro->ro_rt == NULL || dst.s_addr != sin->sin_addr.s_addr) {
1803                 if (ro->ro_rt != NULL) {
1804                         RTFREE(ro->ro_rt);
1805                         ro->ro_rt = NULL;
1806                 }
1807                 sin->sin_family = AF_INET;
1808                 sin->sin_len = sizeof *sin;
1809                 sin->sin_addr = dst;
1810                 rtalloc_ign(ro, RTF_PRCLONING);
1811         }
1812
1813         if (ro->ro_rt == NULL)
1814                 return (NULL);
1815
1816         ia = ifatoia(ro->ro_rt->rt_ifa);
1817
1818         if (ro == &sro)
1819                 RTFREE(ro->ro_rt);
1820         return ia;
1821 }
1822
1823 /*
1824  * Save incoming source route for use in replies,
1825  * to be picked up later by ip_srcroute if the receiver is interested.
1826  */
1827 static void
1828 save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1829 {
1830         struct m_tag *mtag;
1831         struct ip_srcrt_opt *opt;
1832         unsigned olen;
1833
1834         mtag = m_tag_get(PACKET_TAG_IPSRCRT, sizeof(*opt), M_NOWAIT);
1835         if (mtag == NULL)
1836                 return;
1837         opt = m_tag_data(mtag);
1838
1839         olen = option[IPOPT_OLEN];
1840 #ifdef DIAGNOSTIC
1841         if (ipprintfs)
1842                 kprintf("save_rte: olen %d\n", olen);
1843 #endif
1844         if (olen > sizeof(opt->ip_srcrt) - (1 + sizeof(dst))) {
1845                 m_tag_free(mtag);
1846                 return;
1847         }
1848         bcopy(option, opt->ip_srcrt.srcopt, olen);
1849         opt->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1850         opt->ip_srcrt.dst = dst;
1851         m_tag_prepend(m, mtag);
1852 }
1853
1854 /*
1855  * Retrieve incoming source route for use in replies,
1856  * in the same form used by setsockopt.
1857  * The first hop is placed before the options, will be removed later.
1858  */
1859 struct mbuf *
1860 ip_srcroute(struct mbuf *m0)
1861 {
1862         struct in_addr *p, *q;
1863         struct mbuf *m;
1864         struct m_tag *mtag;
1865         struct ip_srcrt_opt *opt;
1866
1867         if (m0 == NULL)
1868                 return NULL;
1869
1870         mtag = m_tag_find(m0, PACKET_TAG_IPSRCRT, NULL);
1871         if (mtag == NULL)
1872                 return NULL;
1873         opt = m_tag_data(mtag);
1874
1875         if (opt->ip_nhops == 0)
1876                 return (NULL);
1877         m = m_get(M_NOWAIT, MT_HEADER);
1878         if (m == NULL)
1879                 return (NULL);
1880
1881 #define OPTSIZ  (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt))
1882
1883         /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1884         m->m_len = opt->ip_nhops * sizeof(struct in_addr) +
1885                    sizeof(struct in_addr) + OPTSIZ;
1886 #ifdef DIAGNOSTIC
1887         if (ipprintfs) {
1888                 kprintf("ip_srcroute: nhops %d mlen %d",
1889                         opt->ip_nhops, m->m_len);
1890         }
1891 #endif
1892
1893         /*
1894          * First save first hop for return route
1895          */
1896         p = &opt->ip_srcrt.route[opt->ip_nhops - 1];
1897         *(mtod(m, struct in_addr *)) = *p--;
1898 #ifdef DIAGNOSTIC
1899         if (ipprintfs)
1900                 kprintf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1901 #endif
1902
1903         /*
1904          * Copy option fields and padding (nop) to mbuf.
1905          */
1906         opt->ip_srcrt.nop = IPOPT_NOP;
1907         opt->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1908         memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &opt->ip_srcrt.nop,
1909             OPTSIZ);
1910         q = (struct in_addr *)(mtod(m, caddr_t) +
1911             sizeof(struct in_addr) + OPTSIZ);
1912 #undef OPTSIZ
1913         /*
1914          * Record return path as an IP source route,
1915          * reversing the path (pointers are now aligned).
1916          */
1917         while (p >= opt->ip_srcrt.route) {
1918 #ifdef DIAGNOSTIC
1919                 if (ipprintfs)
1920                         kprintf(" %x", ntohl(q->s_addr));
1921 #endif
1922                 *q++ = *p--;
1923         }
1924         /*
1925          * Last hop goes to final destination.
1926          */
1927         *q = opt->ip_srcrt.dst;
1928         m_tag_delete(m0, mtag);
1929 #ifdef DIAGNOSTIC
1930         if (ipprintfs)
1931                 kprintf(" %x\n", ntohl(q->s_addr));
1932 #endif
1933         return (m);
1934 }
1935
1936 /*
1937  * Strip out IP options.
1938  */
1939 void
1940 ip_stripoptions(struct mbuf *m)
1941 {
1942         int datalen;
1943         struct ip *ip = mtod(m, struct ip *);
1944         caddr_t opts;
1945         int optlen;
1946
1947         optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1948         opts = (caddr_t)(ip + 1);
1949         datalen = m->m_len - (sizeof(struct ip) + optlen);
1950         bcopy(opts + optlen, opts, datalen);
1951         m->m_len -= optlen;
1952         if (m->m_flags & M_PKTHDR)
1953                 m->m_pkthdr.len -= optlen;
1954         ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1955 }
1956
1957 u_char inetctlerrmap[PRC_NCMDS] = {
1958         0,              0,              0,              0,
1959         0,              EMSGSIZE,       EHOSTDOWN,      EHOSTUNREACH,
1960         EHOSTUNREACH,   EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
1961         EMSGSIZE,       EHOSTUNREACH,   0,              0,
1962         0,              0,              0,              0,
1963         ENOPROTOOPT,    ECONNREFUSED
1964 };
1965
1966 /*
1967  * Forward a packet.  If some error occurs return the sender
1968  * an icmp packet.  Note we can't always generate a meaningful
1969  * icmp message because icmp doesn't have a large enough repertoire
1970  * of codes and types.
1971  *
1972  * If not forwarding, just drop the packet.  This could be confusing
1973  * if ipforwarding was zero but some routing protocol was advancing
1974  * us as a gateway to somewhere.  However, we must let the routing
1975  * protocol deal with that.
1976  *
1977  * The using_srcrt parameter indicates whether the packet is being forwarded
1978  * via a source route.
1979  */
1980 void
1981 ip_forward(struct mbuf *m, boolean_t using_srcrt, struct sockaddr_in *next_hop)
1982 {
1983         struct ip *ip = mtod(m, struct ip *);
1984         struct rtentry *rt;
1985         struct route fwd_ro;
1986         int error, type = 0, code = 0, destmtu = 0;
1987         struct mbuf *mcopy, *mtemp = NULL;
1988         n_long dest;
1989         struct in_addr pkt_dst;
1990
1991         dest = INADDR_ANY;
1992         /*
1993          * Cache the destination address of the packet; this may be
1994          * changed by use of 'ipfw fwd'.
1995          */
1996         pkt_dst = (next_hop != NULL) ? next_hop->sin_addr : ip->ip_dst;
1997
1998 #ifdef DIAGNOSTIC
1999         if (ipprintfs)
2000                 kprintf("forward: src %x dst %x ttl %x\n",
2001                        ip->ip_src.s_addr, pkt_dst.s_addr, ip->ip_ttl);
2002 #endif
2003
2004         if (m->m_flags & (M_BCAST | M_MCAST) || !in_canforward(pkt_dst)) {
2005                 ipstat.ips_cantforward++;
2006                 m_freem(m);
2007                 return;
2008         }
2009         if (!ipstealth && ip->ip_ttl <= IPTTLDEC) {
2010                 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
2011                 return;
2012         }
2013
2014         bzero(&fwd_ro, sizeof(fwd_ro));
2015         ip_rtaddr(pkt_dst, &fwd_ro);
2016         if (fwd_ro.ro_rt == NULL) {
2017                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
2018                 return;
2019         }
2020         rt = fwd_ro.ro_rt;
2021
2022         if (curthread->td_type == TD_TYPE_NETISR) {
2023                 /*
2024                  * Save the IP header and at most 8 bytes of the payload,
2025                  * in case we need to generate an ICMP message to the src.
2026                  */
2027                 mtemp = ipforward_mtemp[mycpuid];
2028                 KASSERT((mtemp->m_flags & M_EXT) == 0 &&
2029                     mtemp->m_data == mtemp->m_pktdat &&
2030                     m_tag_first(mtemp) == NULL,
2031                     ("ip_forward invalid mtemp1"));
2032
2033                 if (!m_dup_pkthdr(mtemp, m, M_NOWAIT)) {
2034                         /*
2035                          * It's probably ok if the pkthdr dup fails (because
2036                          * the deep copy of the tag chain failed), but for now
2037                          * be conservative and just discard the copy since
2038                          * code below may some day want the tags.
2039                          */
2040                         mtemp = NULL;
2041                 } else {
2042                         mtemp->m_type = m->m_type;
2043                         mtemp->m_len = imin((IP_VHL_HL(ip->ip_vhl) << 2) + 8,
2044                             (int)ip->ip_len);
2045                         mtemp->m_pkthdr.len = mtemp->m_len;
2046                         m_copydata(m, 0, mtemp->m_len, mtod(mtemp, caddr_t));
2047                 }
2048         }
2049
2050         if (!ipstealth)
2051                 ip->ip_ttl -= IPTTLDEC;
2052
2053         /*
2054          * If forwarding packet using same interface that it came in on,
2055          * perhaps should send a redirect to sender to shortcut a hop.
2056          * Only send redirect if source is sending directly to us,
2057          * and if packet was not source routed (or has any options).
2058          * Also, don't send redirect if forwarding using a default route
2059          * or a route modified by a redirect.
2060          */
2061         if (rt->rt_ifp == m->m_pkthdr.rcvif &&
2062             !(rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) &&
2063             satosin(rt_key(rt))->sin_addr.s_addr != INADDR_ANY &&
2064             ipsendredirects && !using_srcrt && next_hop == NULL) {
2065                 u_long src = ntohl(ip->ip_src.s_addr);
2066                 struct in_ifaddr *rt_ifa = (struct in_ifaddr *)rt->rt_ifa;
2067
2068                 if (rt_ifa != NULL &&
2069                     (src & rt_ifa->ia_subnetmask) == rt_ifa->ia_subnet) {
2070                         if (rt->rt_flags & RTF_GATEWAY)
2071                                 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
2072                         else
2073                                 dest = pkt_dst.s_addr;
2074                         /*
2075                          * Router requirements says to only send
2076                          * host redirects.
2077                          */
2078                         type = ICMP_REDIRECT;
2079                         code = ICMP_REDIRECT_HOST;
2080 #ifdef DIAGNOSTIC
2081                         if (ipprintfs)
2082                                 kprintf("redirect (%d) to %x\n", code, dest);
2083 #endif
2084                 }
2085         }
2086
2087         error = ip_output(m, NULL, &fwd_ro, IP_FORWARDING, NULL, NULL);
2088         if (error == 0) {
2089                 ipstat.ips_forward++;
2090                 if (type == 0) {
2091                         if (mtemp)
2092                                 ipflow_create(&fwd_ro, mtemp);
2093                         goto done;
2094                 }
2095                 ipstat.ips_redirectsent++;
2096         } else {
2097                 ipstat.ips_cantforward++;
2098         }
2099
2100         if (mtemp == NULL)
2101                 goto done;
2102
2103         /*
2104          * Errors that do not require generating ICMP message
2105          */
2106         switch (error) {
2107         case ENOBUFS:
2108                 /*
2109                  * A router should not generate ICMP_SOURCEQUENCH as
2110                  * required in RFC1812 Requirements for IP Version 4 Routers.
2111                  * Source quench could be a big problem under DoS attacks,
2112                  * or if the underlying interface is rate-limited.
2113                  * Those who need source quench packets may re-enable them
2114                  * via the net.inet.ip.sendsourcequench sysctl.
2115                  */
2116                 if (!ip_sendsourcequench)
2117                         goto done;
2118                 break;
2119
2120         case EACCES:                    /* ipfw denied packet */
2121                 goto done;
2122         }
2123
2124         KASSERT((mtemp->m_flags & M_EXT) == 0 &&
2125             mtemp->m_data == mtemp->m_pktdat,
2126             ("ip_forward invalid mtemp2"));
2127         mcopy = m_copym(mtemp, 0, mtemp->m_len, M_NOWAIT);
2128         if (mcopy == NULL)
2129                 goto done;
2130
2131         /*
2132          * Send ICMP message.
2133          */
2134         switch (error) {
2135         case 0:                         /* forwarded, but need redirect */
2136                 /* type, code set above */
2137                 break;
2138
2139         case ENETUNREACH:               /* shouldn't happen, checked above */
2140         case EHOSTUNREACH:
2141         case ENETDOWN:
2142         case EHOSTDOWN:
2143         default:
2144                 type = ICMP_UNREACH;
2145                 code = ICMP_UNREACH_HOST;
2146                 break;
2147
2148         case EMSGSIZE:
2149                 type = ICMP_UNREACH;
2150                 code = ICMP_UNREACH_NEEDFRAG;
2151 #ifdef IPSEC
2152                 /*
2153                  * If the packet is routed over IPsec tunnel, tell the
2154                  * originator the tunnel MTU.
2155                  *      tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2156                  * XXX quickhack!!!
2157                  */
2158                 if (fwd_ro.ro_rt != NULL) {
2159                         struct secpolicy *sp = NULL;
2160                         int ipsecerror;
2161                         int ipsechdr;
2162                         struct route *ro;
2163
2164                         sp = ipsec4_getpolicybyaddr(mcopy,
2165                                                     IPSEC_DIR_OUTBOUND,
2166                                                     IP_FORWARDING,
2167                                                     &ipsecerror);
2168
2169                         if (sp == NULL)
2170                                 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2171                         else {
2172                                 /* count IPsec header size */
2173                                 ipsechdr = ipsec4_hdrsiz(mcopy,
2174                                                          IPSEC_DIR_OUTBOUND,
2175                                                          NULL);
2176
2177                                 /*
2178                                  * find the correct route for outer IPv4
2179                                  * header, compute tunnel MTU.
2180                                  *
2181                                  */
2182                                 if (sp->req != NULL && sp->req->sav != NULL &&
2183                                     sp->req->sav->sah != NULL) {
2184                                         ro = &sp->req->sav->sah->sa_route;
2185                                         if (ro->ro_rt != NULL &&
2186                                             ro->ro_rt->rt_ifp != NULL) {
2187                                                 destmtu =
2188                                                     ro->ro_rt->rt_ifp->if_mtu;
2189                                                 destmtu -= ipsechdr;
2190                                         }
2191                                 }
2192
2193                                 key_freesp(sp);
2194                         }
2195                 }
2196 #elif defined(FAST_IPSEC)
2197                 /*
2198                  * If the packet is routed over IPsec tunnel, tell the
2199                  * originator the tunnel MTU.
2200                  *      tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2201                  * XXX quickhack!!!
2202                  */
2203                 if (fwd_ro.ro_rt != NULL) {
2204                         struct secpolicy *sp = NULL;
2205                         int ipsecerror;
2206                         int ipsechdr;
2207                         struct route *ro;
2208
2209                         sp = ipsec_getpolicybyaddr(mcopy,
2210                                                    IPSEC_DIR_OUTBOUND,
2211                                                    IP_FORWARDING,
2212                                                    &ipsecerror);
2213
2214                         if (sp == NULL)
2215                                 destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2216                         else {
2217                                 /* count IPsec header size */
2218                                 ipsechdr = ipsec4_hdrsiz(mcopy,
2219                                                          IPSEC_DIR_OUTBOUND,
2220                                                          NULL);
2221
2222                                 /*
2223                                  * find the correct route for outer IPv4
2224                                  * header, compute tunnel MTU.
2225                                  */
2226
2227                                 if (sp->req != NULL &&
2228                                     sp->req->sav != NULL &&
2229                                     sp->req->sav->sah != NULL) {
2230                                         ro = &sp->req->sav->sah->sa_route;
2231                                         if (ro->ro_rt != NULL &&
2232                                             ro->ro_rt->rt_ifp != NULL) {
2233                                                 destmtu =
2234                                                     ro->ro_rt->rt_ifp->if_mtu;
2235                                                 destmtu -= ipsechdr;
2236                                         }
2237                                 }
2238
2239                                 KEY_FREESP(&sp);
2240                         }
2241                 }
2242 #else /* !IPSEC && !FAST_IPSEC */
2243                 if (fwd_ro.ro_rt != NULL)
2244                         destmtu = fwd_ro.ro_rt->rt_ifp->if_mtu;
2245 #endif /*IPSEC*/
2246                 ipstat.ips_cantfrag++;
2247                 break;
2248
2249         case ENOBUFS:
2250                 type = ICMP_SOURCEQUENCH;
2251                 code = 0;
2252                 break;
2253
2254         case EACCES:                    /* ipfw denied packet */
2255                 panic("ip_forward EACCES should not reach");
2256         }
2257         icmp_error(mcopy, type, code, dest, destmtu);
2258 done:
2259         if (mtemp != NULL)
2260                 m_tag_delete_chain(mtemp);
2261         if (fwd_ro.ro_rt != NULL)
2262                 RTFREE(fwd_ro.ro_rt);
2263 }
2264
2265 void
2266 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
2267                struct mbuf *m)
2268 {
2269         if (inp->inp_socket->so_options & SO_TIMESTAMP) {
2270                 struct timeval tv;
2271
2272                 microtime(&tv);
2273                 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
2274                     SCM_TIMESTAMP, SOL_SOCKET);
2275                 if (*mp)
2276                         mp = &(*mp)->m_next;
2277         }
2278         if (inp->inp_flags & INP_RECVDSTADDR) {
2279                 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
2280                     sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2281                 if (*mp)
2282                         mp = &(*mp)->m_next;
2283         }
2284         if (inp->inp_flags & INP_RECVTTL) {
2285                 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
2286                     sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
2287                 if (*mp)
2288                         mp = &(*mp)->m_next;
2289         }
2290 #ifdef notyet
2291         /* XXX
2292          * Moving these out of udp_input() made them even more broken
2293          * than they already were.
2294          */
2295         /* options were tossed already */
2296         if (inp->inp_flags & INP_RECVOPTS) {
2297                 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
2298                     sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
2299                 if (*mp)
2300                         mp = &(*mp)->m_next;
2301         }
2302         /* ip_srcroute doesn't do what we want here, need to fix */
2303         if (inp->inp_flags & INP_RECVRETOPTS) {
2304                 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
2305                     sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
2306                 if (*mp)
2307                         mp = &(*mp)->m_next;
2308         }
2309 #endif
2310         if (inp->inp_flags & INP_RECVIF) {
2311                 struct ifnet *ifp;
2312                 struct sdlbuf {
2313                         struct sockaddr_dl sdl;
2314                         u_char  pad[32];
2315                 } sdlbuf;
2316                 struct sockaddr_dl *sdp;
2317                 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
2318
2319                 if (((ifp = m->m_pkthdr.rcvif)) &&
2320                     ((ifp->if_index != 0) && (ifp->if_index <= if_index))) {
2321                         sdp = IF_LLSOCKADDR(ifp);
2322                         /*
2323                          * Change our mind and don't try copy.
2324                          */
2325                         if ((sdp->sdl_family != AF_LINK) ||
2326                             (sdp->sdl_len > sizeof(sdlbuf))) {
2327                                 goto makedummy;
2328                         }
2329                         bcopy(sdp, sdl2, sdp->sdl_len);
2330                 } else {
2331 makedummy:
2332                         sdl2->sdl_len =
2333                             offsetof(struct sockaddr_dl, sdl_data[0]);
2334                         sdl2->sdl_family = AF_LINK;
2335                         sdl2->sdl_index = 0;
2336                         sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2337                 }
2338                 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2339                         IP_RECVIF, IPPROTO_IP);
2340                 if (*mp)
2341                         mp = &(*mp)->m_next;
2342         }
2343 }
2344
2345 /*
2346  * XXX these routines are called from the upper part of the kernel.
2347  *
2348  * They could also be moved to ip_mroute.c, since all the RSVP
2349  *  handling is done there already.
2350  */
2351 int
2352 ip_rsvp_init(struct socket *so)
2353 {
2354         if (so->so_type != SOCK_RAW ||
2355             so->so_proto->pr_protocol != IPPROTO_RSVP)
2356                 return EOPNOTSUPP;
2357
2358         if (ip_rsvpd != NULL)
2359                 return EADDRINUSE;
2360
2361         ip_rsvpd = so;
2362         /*
2363          * This may seem silly, but we need to be sure we don't over-increment
2364          * the RSVP counter, in case something slips up.
2365          */
2366         if (!ip_rsvp_on) {
2367                 ip_rsvp_on = 1;
2368                 rsvp_on++;
2369         }
2370
2371         return 0;
2372 }
2373
2374 int
2375 ip_rsvp_done(void)
2376 {
2377         ip_rsvpd = NULL;
2378         /*
2379          * This may seem silly, but we need to be sure we don't over-decrement
2380          * the RSVP counter, in case something slips up.
2381          */
2382         if (ip_rsvp_on) {
2383                 ip_rsvp_on = 0;
2384                 rsvp_on--;
2385         }
2386         return 0;
2387 }
2388
2389 int
2390 rsvp_input(struct mbuf **mp, int *offp, int proto)
2391 {
2392         struct mbuf *m = *mp;
2393
2394         *mp = NULL;
2395
2396         if (rsvp_input_p) { /* call the real one if loaded */
2397                 *mp = m;
2398                 rsvp_input_p(mp, offp, proto);
2399                 return(IPPROTO_DONE);
2400         }
2401
2402         /* Can still get packets with rsvp_on = 0 if there is a local member
2403          * of the group to which the RSVP packet is addressed.  But in this
2404          * case we want to throw the packet away.
2405          */
2406
2407         if (!rsvp_on) {
2408                 m_freem(m);
2409                 return(IPPROTO_DONE);
2410         }
2411
2412         if (ip_rsvpd != NULL) {
2413                 *mp = m;
2414                 rip_input(mp, offp, proto);
2415                 return(IPPROTO_DONE);
2416         }
2417         /* Drop the packet */
2418         m_freem(m);
2419         return(IPPROTO_DONE);
2420 }