slirp/ip_input.c

   1 /*
   2  * Copyright (c) 1982, 1986, 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)ip_input.c  8.2 (Berkeley) 1/4/94
  34  * ip_input.c,v 1.11 1994/11/16 10:17:08 jkh Exp
  35  */
  36
  37 /*
  38  * Changes and additions relating to SLiRP are
  39  * Copyright (c) 1995 Danny Gasparovski.
  40  *
  41  * Please read the file COPYRIGHT for the
  42  * terms and conditions of the copyright.
  43  */
  44
  45 #include <slirp.h>
  46 #include "ip_icmp.h"
  47
  48 int ip_defttl;
  49 struct ipstat ipstat;
  50 struct ipq ipq;
  51
  52 /*
  53  * IP initialization: fill in IP protocol switch table.
  54  * All protocols not implemented in kernel go to raw IP protocol handler.
  55  */
  56 void
  57 ip_init()
  58 {
  59         ipq.next = ipq.prev = (ipqp_32)&ipq;
  60         ip_id = tt.tv_sec & 0xffff;
  61         udp_init();
  62         tcp_init();
  63         ip_defttl = IPDEFTTL;
  64 }
  65
  66 /*
  67  * Ip input routine.  Checksum and byte swap header.  If fragmented
  68  * try to reassemble.  Process options.  Pass to next level.
  69  */
  70 void
  71 ip_input(m)
  72         struct mbuf *m;
  73 {
  74         register struct ip *ip;
  75         int hlen;
  76
  77         DEBUG_CALL("ip_input");
  78         DEBUG_ARG("m = %lx", (long)m);
  79         DEBUG_ARG("m_len = %d", m->m_len);
  80
  81         ipstat.ips_total++;
  82
  83         if (m->m_len < sizeof (struct ip)) {
  84                 ipstat.ips_toosmall++;
  85                 return;
  86         }
  87
  88         ip = mtod(m, struct ip *);
  89
  90         if (ip->ip_v != IPVERSION) {
  91                 ipstat.ips_badvers++;
  92                 goto bad;
  93         }
  94
  95         hlen = ip->ip_hl << 2;
  96         if (hlen<sizeof(struct ip ) || hlen>m->m_len) {/* min header length */
  97           ipstat.ips_badhlen++;                     /* or packet too short */
  98           goto bad;
  99         }
 100
 101         /* keep ip header intact for ICMP reply
 102          * ip->ip_sum = cksum(m, hlen);
 103          * if (ip->ip_sum) {
 104          */
 105         if(cksum(m,hlen)) {
 106           ipstat.ips_badsum++;
 107           goto bad;
 108         }
 109
 110         /*
 111          * Convert fields to host representation.
 112          */
 113         NTOHS(ip->ip_len);
 114         if (ip->ip_len < hlen) {
 115                 ipstat.ips_badlen++;
 116                 goto bad;
 117         }
 118         NTOHS(ip->ip_id);
 119         NTOHS(ip->ip_off);
 120
 121         /*
 122          * Check that the amount of data in the buffers
 123          * is as at least much as the IP header would have us expect.
 124          * Trim mbufs if longer than we expect.
 125          * Drop packet if shorter than we expect.
 126          */
 127         if (m->m_len < ip->ip_len) {
 128                 ipstat.ips_tooshort++;
 129                 goto bad;
 130         }
 131         /* Should drop packet if mbuf too long? hmmm... */
 132         if (m->m_len > ip->ip_len)
 133            m_adj(m, ip->ip_len - m->m_len);
 134
 135         /* check ip_ttl for a correct ICMP reply */
 136         if(ip->ip_ttl==0 || ip->ip_ttl==1) {
 137           icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");
 138           goto bad;
 139         }
 140
 141         /*
 142          * Process options and, if not destined for us,
 143          * ship it on.  ip_dooptions returns 1 when an
 144          * error was detected (causing an icmp message
 145          * to be sent and the original packet to be freed).
 146          */
 147 /* We do no IP options */
 148 /*      if (hlen > sizeof (struct ip) && ip_dooptions(m))
 149  *              goto next;
 150  */
 151         /*
 152          * If offset or IP_MF are set, must reassemble.
 153          * Otherwise, nothing need be done.
 154          * (We could look in the reassembly queue to see
 155          * if the packet was previously fragmented,
 156          * but it's not worth the time; just let them time out.)
 157          *
 158          * XXX This should fail, don't fragment yet
 159          */
 160         if (ip->ip_off &~ IP_DF) {
 161           register struct ipq *fp;
 162                 /*
 163                  * Look for queue of fragments
 164                  * of this datagram.
 165                  */
 166                 for (fp = (struct ipq *) ipq.next; fp != &ipq;
 167                      fp = (struct ipq *) fp->next)
 168                   if (ip->ip_id == fp->ipq_id &&
 169                       ip->ip_src.s_addr == fp->ipq_src.s_addr &&
 170                       ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
 171                       ip->ip_p == fp->ipq_p)
 172                     goto found;
 173                 fp = 0;
 174         found:
 175
 176                 /*
 177                  * Adjust ip_len to not reflect header,
 178                  * set ip_mff if more fragments are expected,
 179                  * convert offset of this to bytes.
 180                  */
 181                 ip->ip_len -= hlen;
 182                 if (ip->ip_off & IP_MF)
 183                   ((struct ipasfrag *)ip)->ipf_mff |= 1;
 184                 else
 185                   ((struct ipasfrag *)ip)->ipf_mff &= ~1;
 186
 187                 ip->ip_off <<= 3;
 188
 189                 /*
 190                  * If datagram marked as having more fragments
 191                  * or if this is not the first fragment,
 192                  * attempt reassembly; if it succeeds, proceed.
 193                  */
 194                 if (((struct ipasfrag *)ip)->ipf_mff & 1 || ip->ip_off) {
 195                         ipstat.ips_fragments++;
 196                         ip = ip_reass((struct ipasfrag *)ip, fp);
 197                         if (ip == 0)
 198                                 return;
 199                         ipstat.ips_reassembled++;
 200                         m = dtom(ip);
 201                 } else
 202                         if (fp)
 203                            ip_freef(fp);
 204
 205         } else
 206                 ip->ip_len -= hlen;
 207
 208         /*
 209          * Switch out to protocol's input routine.
 210          */
 211         ipstat.ips_delivered++;
 212         switch (ip->ip_p) {
 213          case IPPROTO_TCP:
 214                 tcp_input(m, hlen, (struct socket *)NULL);
 215                 break;
 216          case IPPROTO_UDP:
 217                 udp_input(m, hlen);
 218                 break;
 219          case IPPROTO_ICMP:
 220                 icmp_input(m, hlen);
 221                 break;
 222          default:
 223                 ipstat.ips_noproto++;
 224                 m_free(m);
 225         }
 226         return;
 227 bad:
 228         m_freem(m);
 229         return;
 230 }
 231
 232 /*
 233  * Take incoming datagram fragment and try to
 234  * reassemble it into whole datagram.  If a chain for
 235  * reassembly of this datagram already exists, then it
 236  * is given as fp; otherwise have to make a chain.
 237  */
 238 struct ip *
 239 ip_reass(ip, fp)
 240         register struct ipasfrag *ip;
 241         register struct ipq *fp;
 242 {
 243         register struct mbuf *m = dtom(ip);
 244         register struct ipasfrag *q;
 245         int hlen = ip->ip_hl << 2;
 246         int i, next;
 247
 248         DEBUG_CALL("ip_reass");
 249         DEBUG_ARG("ip = %lx", (long)ip);
 250         DEBUG_ARG("fp = %lx", (long)fp);
 251         DEBUG_ARG("m = %lx", (long)m);
 252
 253         /*
 254          * Presence of header sizes in mbufs
 255          * would confuse code below.
 256          * Fragment m_data is concatenated.
 257          */
 258         m->m_data += hlen;
 259         m->m_len -= hlen;
 260
 261         /*
 262          * If first fragment to arrive, create a reassembly queue.
 263          */
 264         if (fp == 0) {
 265           struct mbuf *t;
 266           if ((t = m_get()) == NULL) goto dropfrag;
 267           fp = mtod(t, struct ipq *);
 268           insque_32(fp, &ipq);
 269           fp->ipq_ttl = IPFRAGTTL;
 270           fp->ipq_p = ip->ip_p;
 271           fp->ipq_id = ip->ip_id;
 272           fp->ipq_next = fp->ipq_prev = (ipasfragp_32)fp;
 273           fp->ipq_src = ((struct ip *)ip)->ip_src;
 274           fp->ipq_dst = ((struct ip *)ip)->ip_dst;
 275           q = (struct ipasfrag *)fp;
 276           goto insert;
 277         }
 278
 279         /*
 280          * Find a segment which begins after this one does.
 281          */
 282         for (q = (struct ipasfrag *)fp->ipq_next; q != (struct ipasfrag *)fp;
 283             q = (struct ipasfrag *)q->ipf_next)
 284                 if (q->ip_off > ip->ip_off)
 285                         break;
 286
 287         /*
 288          * If there is a preceding segment, it may provide some of
 289          * our data already.  If so, drop the data from the incoming
 290          * segment.  If it provides all of our data, drop us.
 291          */
 292         if (q->ipf_prev != (ipasfragp_32)fp) {
 293                 i = ((struct ipasfrag *)(q->ipf_prev))->ip_off +
 294                   ((struct ipasfrag *)(q->ipf_prev))->ip_len - ip->ip_off;
 295                 if (i > 0) {
 296                         if (i >= ip->ip_len)
 297                                 goto dropfrag;
 298                         m_adj(dtom(ip), i);
 299                         ip->ip_off += i;
 300                         ip->ip_len -= i;
 301                 }
 302         }
 303
 304         /*
 305          * While we overlap succeeding segments trim them or,
 306          * if they are completely covered, dequeue them.
 307          */
 308         while (q != (struct ipasfrag *)fp && ip->ip_off + ip->ip_len > q->ip_off) {
 309                 i = (ip->ip_off + ip->ip_len) - q->ip_off;
 310                 if (i < q->ip_len) {
 311                         q->ip_len -= i;
 312                         q->ip_off += i;
 313                         m_adj(dtom(q), i);
 314                         break;
 315                 }
 316                 q = (struct ipasfrag *) q->ipf_next;
 317                 m_freem(dtom((struct ipasfrag *) q->ipf_prev));
 318                 ip_deq((struct ipasfrag *) q->ipf_prev);
 319         }
 320
 321 insert:
 322         /*
 323          * Stick new segment in its place;
 324          * check for complete reassembly.
 325          */
 326         ip_enq(ip, (struct ipasfrag *) q->ipf_prev);
 327         next = 0;
 328         for (q = (struct ipasfrag *) fp->ipq_next; q != (struct ipasfrag *)fp;
 329              q = (struct ipasfrag *) q->ipf_next) {
 330                 if (q->ip_off != next)
 331                         return (0);
 332                 next += q->ip_len;
 333         }
 334         if (((struct ipasfrag *)(q->ipf_prev))->ipf_mff & 1)
 335                 return (0);
 336
 337         /*
 338          * Reassembly is complete; concatenate fragments.
 339          */
 340         q = (struct ipasfrag *) fp->ipq_next;
 341         m = dtom(q);
 342
 343         q = (struct ipasfrag *) q->ipf_next;
 344         while (q != (struct ipasfrag *)fp) {
 345           struct mbuf *t;
 346           t = dtom(q);
 347           q = (struct ipasfrag *) q->ipf_next;
 348           m_cat(m, t);
 349         }
 350
 351         /*
 352          * Create header for new ip packet by
 353          * modifying header of first packet;
 354          * dequeue and discard fragment reassembly header.
 355          * Make header visible.
 356          */
 357         ip = (struct ipasfrag *) fp->ipq_next;
 358
 359         /*
 360          * If the fragments concatenated to an mbuf that's
 361          * bigger than the total size of the fragment, then and
 362          * m_ext buffer was alloced. But fp->ipq_next points to
 363          * the old buffer (in the mbuf), so we must point ip
 364          * into the new buffer.
 365          */
 366         if (m->m_flags & M_EXT) {
 367           int delta;
 368           delta = (char *)ip - m->m_dat;
 369           ip = (struct ipasfrag *)(m->m_ext + delta);
 370         }
 371
 372         /* DEBUG_ARG("ip = %lx", (long)ip);
 373          * ip=(struct ipasfrag *)m->m_data; */
 374
 375         ip->ip_len = next;
 376         ip->ipf_mff &= ~1;
 377         ((struct ip *)ip)->ip_src = fp->ipq_src;
 378         ((struct ip *)ip)->ip_dst = fp->ipq_dst;
 379         remque_32(fp);
 380         (void) m_free(dtom(fp));
 381         m = dtom(ip);
 382         m->m_len += (ip->ip_hl << 2);
 383         m->m_data -= (ip->ip_hl << 2);
 384
 385         return ((struct ip *)ip);
 386
 387 dropfrag:
 388         ipstat.ips_fragdropped++;
 389         m_freem(m);
 390         return (0);
 391 }
 392
 393 /*
 394  * Free a fragment reassembly header and all
 395  * associated datagrams.
 396  */
 397 void
 398 ip_freef(fp)
 399         struct ipq *fp;
 400 {
 401         register struct ipasfrag *q, *p;
 402
 403         for (q = (struct ipasfrag *) fp->ipq_next; q != (struct ipasfrag *)fp;
 404             q = p) {
 405                 p = (struct ipasfrag *) q->ipf_next;
 406                 ip_deq(q);
 407                 m_freem(dtom(q));
 408         }
 409         remque_32(fp);
 410         (void) m_free(dtom(fp));
 411 }
 412
 413 /*
 414  * Put an ip fragment on a reassembly chain.
 415  * Like insque, but pointers in middle of structure.
 416  */
 417 void
 418 ip_enq(p, prev)
 419         register struct ipasfrag *p, *prev;
 420 {
 421         DEBUG_CALL("ip_enq");
 422         DEBUG_ARG("prev = %lx", (long)prev);
 423         p->ipf_prev = (ipasfragp_32) prev;
 424         p->ipf_next = prev->ipf_next;
 425         ((struct ipasfrag *)(prev->ipf_next))->ipf_prev = (ipasfragp_32) p;
 426         prev->ipf_next = (ipasfragp_32) p;
 427 }
 428
 429 /*
 430  * To ip_enq as remque is to insque.
 431  */
 432 void
 433 ip_deq(p)
 434         register struct ipasfrag *p;
 435 {
 436         ((struct ipasfrag *)(p->ipf_prev))->ipf_next = p->ipf_next;
 437         ((struct ipasfrag *)(p->ipf_next))->ipf_prev = p->ipf_prev;
 438 }
 439
 440 /*
 441  * IP timer processing;
 442  * if a timer expires on a reassembly
 443  * queue, discard it.
 444  */
 445 void
 446 ip_slowtimo()
 447 {
 448         register struct ipq *fp;
 449
 450         DEBUG_CALL("ip_slowtimo");
 451
 452         fp = (struct ipq *) ipq.next;
 453         if (fp == 0)
 454            return;
 455
 456         while (fp != &ipq) {
 457                 --fp->ipq_ttl;
 458                 fp = (struct ipq *) fp->next;
 459                 if (((struct ipq *)(fp->prev))->ipq_ttl == 0) {
 460                         ipstat.ips_fragtimeout++;
 461                         ip_freef((struct ipq *) fp->prev);
 462                 }
 463         }
 464 }
 465
 466 /*
 467  * Do option processing on a datagram,
 468  * possibly discarding it if bad options are encountered,
 469  * or forwarding it if source-routed.
 470  * Returns 1 if packet has been forwarded/freed,
 471  * 0 if the packet should be processed further.
 472  */
 473
 474 #ifdef notdef
 475
 476 int
 477 ip_dooptions(m)
 478         struct mbuf *m;
 479 {
 480         register struct ip *ip = mtod(m, struct ip *);
 481         register u_char *cp;
 482         register struct ip_timestamp *ipt;
 483         register struct in_ifaddr *ia;
 484 /*      int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; */
 485         int opt, optlen, cnt, off, code, type, forward = 0;
 486         struct in_addr *sin, dst;
 487 typedef u_int32_t n_time;
 488         n_time ntime;
 489
 490         dst = ip->ip_dst;
 491         cp = (u_char *)(ip + 1);
 492         cnt = (ip->ip_hl << 2) - sizeof (struct ip);
 493         for (; cnt > 0; cnt -= optlen, cp += optlen) {
 494                 opt = cp[IPOPT_OPTVAL];
 495                 if (opt == IPOPT_EOL)
 496                         break;
 497                 if (opt == IPOPT_NOP)
 498                         optlen = 1;
 499                 else {
 500                         optlen = cp[IPOPT_OLEN];
 501                         if (optlen <= 0 || optlen > cnt) {
 502                                 code = &cp[IPOPT_OLEN] - (u_char *)ip;
 503                                 goto bad;
 504                         }
 505                 }
 506                 switch (opt) {
 507
 508                 default:
 509                         break;
 510
 511                 /*
 512                  * Source routing with record.
 513                  * Find interface with current destination address.
 514                  * If none on this machine then drop if strictly routed,
 515                  * or do nothing if loosely routed.
 516                  * Record interface address and bring up next address
 517                  * component.  If strictly routed make sure next
 518                  * address is on directly accessible net.
 519                  */
 520                 case IPOPT_LSRR:
 521                 case IPOPT_SSRR:
 522                         if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
 523                                 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
 524                                 goto bad;
 525                         }
 526                         ipaddr.sin_addr = ip->ip_dst;
 527                         ia = (struct in_ifaddr *)
 528                                 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
 529                         if (ia == 0) {
 530                                 if (opt == IPOPT_SSRR) {
 531                                         type = ICMP_UNREACH;
 532                                         code = ICMP_UNREACH_SRCFAIL;
 533                                         goto bad;
 534                                 }
 535                                 /*
 536                                  * Loose routing, and not at next destination
 537                                  * yet; nothing to do except forward.
 538                                  */
 539                                 break;
 540                         }
 541                         off--;                  / * 0 origin *  /
 542                         if (off > optlen - sizeof(struct in_addr)) {
 543                                 /*
 544                                  * End of source route.  Should be for us.
 545                                  */
 546                                 save_rte(cp, ip->ip_src);
 547                                 break;
 548                         }
 549                         /*
 550                          * locate outgoing interface
 551                          */
 552                         bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
 553                             sizeof(ipaddr.sin_addr));
 554                         if (opt == IPOPT_SSRR) {
 555 #define INA     struct in_ifaddr *
 556 #define SA      struct sockaddr *
 557                             if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
 558                                 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
 559                         } else
 560                                 ia = ip_rtaddr(ipaddr.sin_addr);
 561                         if (ia == 0) {
 562                                 type = ICMP_UNREACH;
 563                                 code = ICMP_UNREACH_SRCFAIL;
 564                                 goto bad;
 565                         }
 566                         ip->ip_dst = ipaddr.sin_addr;
 567                         bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
 568                             (caddr_t)(cp + off), sizeof(struct in_addr));
 569                         cp[IPOPT_OFFSET] += sizeof(struct in_addr);
 570                         /*
 571                          * Let ip_intr's mcast routing check handle mcast pkts
 572                          */
 573                         forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
 574                         break;
 575
 576                 case IPOPT_RR:
 577                         if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
 578                                 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
 579                                 goto bad;
 580                         }
 581                         /*
 582                          * If no space remains, ignore.
 583                          */
 584                         off--;                   * 0 origin *
 585                         if (off > optlen - sizeof(struct in_addr))
 586                                 break;
 587                         bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
 588                             sizeof(ipaddr.sin_addr));
 589                         /*
 590                          * locate outgoing interface; if we're the destination,
 591                          * use the incoming interface (should be same).
 592                          */
 593                         if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
 594                             (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
 595                                 type = ICMP_UNREACH;
 596                                 code = ICMP_UNREACH_HOST;
 597                                 goto bad;
 598                         }
 599                         bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
 600                             (caddr_t)(cp + off), sizeof(struct in_addr));
 601                         cp[IPOPT_OFFSET] += sizeof(struct in_addr);
 602                         break;
 603
 604                 case IPOPT_TS:
 605                         code = cp - (u_char *)ip;
 606                         ipt = (struct ip_timestamp *)cp;
 607                         if (ipt->ipt_len < 5)
 608                                 goto bad;
 609                         if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
 610                                 if (++ipt->ipt_oflw == 0)
 611                                         goto bad;
 612                                 break;
 613                         }
 614                         sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
 615                         switch (ipt->ipt_flg) {
 616
 617                         case IPOPT_TS_TSONLY:
 618                                 break;
 619
 620                         case IPOPT_TS_TSANDADDR:
 621                                 if (ipt->ipt_ptr + sizeof(n_time) +
 622                                     sizeof(struct in_addr) > ipt->ipt_len)
 623                                         goto bad;
 624                                 ipaddr.sin_addr = dst;
 625                                 ia = (INA)ifaof_ i f p foraddr((SA)&ipaddr,
 626                                                             m->m_pkthdr.rcvif);
 627                                 if (ia == 0)
 628                                         continue;
 629                                 bcopy((caddr_t)&IA_SIN(ia)->sin_addr,
 630                                     (caddr_t)sin, sizeof(struct in_addr));
 631                                 ipt->ipt_ptr += sizeof(struct in_addr);
 632                                 break;
 633
 634                         case IPOPT_TS_PRESPEC:
 635                                 if (ipt->ipt_ptr + sizeof(n_time) +
 636                                     sizeof(struct in_addr) > ipt->ipt_len)
 637                                         goto bad;
 638                                 bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
 639                                     sizeof(struct in_addr));
 640                                 if (ifa_ifwithaddr((SA)&ipaddr) == 0)
 641                                         continue;
 642                                 ipt->ipt_ptr += sizeof(struct in_addr);
 643                                 break;
 644
 645                         default:
 646                                 goto bad;
 647                         }
 648                         ntime = iptime();
 649                         bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
 650                             sizeof(n_time));
 651                         ipt->ipt_ptr += sizeof(n_time);
 652                 }
 653         }
 654         if (forward) {
 655                 ip_forward(m, 1);
 656                 return (1);
 657         }
 658                 }
 659         }
 660         return (0);
 661 bad:
 662         /* ip->ip_len -= ip->ip_hl << 2;   XXX icmp_error adds in hdr length */
 663
 664 /* Not yet */
 665         icmp_error(m, type, code, 0, 0);
 666
 667         ipstat.ips_badoptions++;
 668         return (1);
 669 }
 670
 671 #endif /* notdef */
 672
 673 /*
 674  * Strip out IP options, at higher
 675  * level protocol in the kernel.
 676  * Second argument is buffer to which options
 677  * will be moved, and return value is their length.
 678  * (XXX) should be deleted; last arg currently ignored.
 679  */
 680 void
 681 ip_stripoptions(m, mopt)
 682         register struct mbuf *m;
 683         struct mbuf *mopt;
 684 {
 685         register int i;
 686         struct ip *ip = mtod(m, struct ip *);
 687         register caddr_t opts;
 688         int olen;
 689
 690         olen = (ip->ip_hl<<2) - sizeof (struct ip);
 691         opts = (caddr_t)(ip + 1);
 692         i = m->m_len - (sizeof (struct ip) + olen);
 693         memcpy(opts, opts  + olen, (unsigned)i);
 694         m->m_len -= olen;
 695
 696         ip->ip_hl = sizeof(struct ip) >> 2;
 697 }