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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)ip_input.c  8.2 (Berkeley) 1/4/94
  30  * ip_input.c,v 1.11 1994/11/16 10:17:08 jkh Exp
  31  */
  32
  33 /*
  34  * Changes and additions relating to SLiRP are
  35  * Copyright (c) 1995 Danny Gasparovski.
  36  *
  37  * Please read the file COPYRIGHT for the
  38  * terms and conditions of the copyright.
  39  */
  40
  41 #include <slirp.h>
  42 #include <osdep.h>
  43 #include "ip_icmp.h"
  44
  45 #ifdef LOG_ENABLED
  46 struct ipstat ipstat;
  47 #endif
  48
  49 struct ipq ipq;
  50
  51 static struct ip *ip_reass(register struct ip *ip,
  52                            register struct ipq *fp);
  53 static void ip_freef(struct ipq *fp);
  54 static void ip_enq(register struct ipasfrag *p,
  55                    register struct ipasfrag *prev);
  56 static void ip_deq(register struct ipasfrag *p);
  57
  58 /*
  59  * IP initialization: fill in IP protocol switch table.
  60  * All protocols not implemented in kernel go to raw IP protocol handler.
  61  */
  62 void
  63 ip_init()
  64 {
  65         ipq.ip_link.next = ipq.ip_link.prev = &ipq.ip_link;
  66         ip_id = tt.tv_sec & 0xffff;
  67         udp_init();
  68         tcp_init();
  69 }
  70
  71 /*
  72  * Ip input routine.  Checksum and byte swap header.  If fragmented
  73  * try to reassemble.  Process options.  Pass to next level.
  74  */
  75 void
  76 ip_input(m)
  77         struct mbuf *m;
  78 {
  79         register struct ip *ip;
  80         int hlen;
  81
  82         DEBUG_CALL("ip_input");
  83         DEBUG_ARG("m = %lx", (long)m);
  84         DEBUG_ARG("m_len = %d", m->m_len);
  85
  86         STAT(ipstat.ips_total++);
  87
  88         if (m->m_len < sizeof (struct ip)) {
  89                 STAT(ipstat.ips_toosmall++);
  90                 return;
  91         }
  92
  93         ip = mtod(m, struct ip *);
  94
  95         if (ip->ip_v != IPVERSION) {
  96                 STAT(ipstat.ips_badvers++);
  97                 goto bad;
  98         }
  99
 100         hlen = ip->ip_hl << 2;
 101         if (hlen<sizeof(struct ip ) || hlen>m->m_len) {/* min header length */
 102           STAT(ipstat.ips_badhlen++);                     /* or packet too short */
 103           goto bad;
 104         }
 105
 106         /* keep ip header intact for ICMP reply
 107          * ip->ip_sum = cksum(m, hlen);
 108          * if (ip->ip_sum) {
 109          */
 110         if(cksum(m,hlen)) {
 111           STAT(ipstat.ips_badsum++);
 112           goto bad;
 113         }
 114
 115         /*
 116          * Convert fields to host representation.
 117          */
 118         NTOHS(ip->ip_len);
 119         if (ip->ip_len < hlen) {
 120                 STAT(ipstat.ips_badlen++);
 121                 goto bad;
 122         }
 123         NTOHS(ip->ip_id);
 124         NTOHS(ip->ip_off);
 125
 126         /*
 127          * Check that the amount of data in the buffers
 128          * is as at least much as the IP header would have us expect.
 129          * Trim mbufs if longer than we expect.
 130          * Drop packet if shorter than we expect.
 131          */
 132         if (m->m_len < ip->ip_len) {
 133                 STAT(ipstat.ips_tooshort++);
 134                 goto bad;
 135         }
 136
 137     if (slirp_restrict) {
 138         if (memcmp(&ip->ip_dst.s_addr, &special_addr, 3)) {
 139             if (ip->ip_dst.s_addr == 0xffffffff && ip->ip_p != IPPROTO_UDP)
 140                 goto bad;
 141         } else {
 142             int host = ntohl(ip->ip_dst.s_addr) & 0xff;
 143             struct ex_list *ex_ptr;
 144
 145             if (host == 0xff)
 146                 goto bad;
 147
 148             for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
 149                 if (ex_ptr->ex_addr == host)
 150                     break;
 151
 152             if (!ex_ptr)
 153                 goto bad;
 154         }
 155     }
 156
 157         /* Should drop packet if mbuf too long? hmmm... */
 158         if (m->m_len > ip->ip_len)
 159            m_adj(m, ip->ip_len - m->m_len);
 160
 161         /* check ip_ttl for a correct ICMP reply */
 162         if(ip->ip_ttl==0 || ip->ip_ttl==1) {
 163           icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");
 164           goto bad;
 165         }
 166
 167         /*
 168          * Process options and, if not destined for us,
 169          * ship it on.  ip_dooptions returns 1 when an
 170          * error was detected (causing an icmp message
 171          * to be sent and the original packet to be freed).
 172          */
 173 /* We do no IP options */
 174 /*      if (hlen > sizeof (struct ip) && ip_dooptions(m))
 175  *              goto next;
 176  */
 177         /*
 178          * If offset or IP_MF are set, must reassemble.
 179          * Otherwise, nothing need be done.
 180          * (We could look in the reassembly queue to see
 181          * if the packet was previously fragmented,
 182          * but it's not worth the time; just let them time out.)
 183          *
 184          * XXX This should fail, don't fragment yet
 185          */
 186         if (ip->ip_off &~ IP_DF) {
 187           register struct ipq *fp;
 188       struct qlink *l;
 189                 /*
 190                  * Look for queue of fragments
 191                  * of this datagram.
 192                  */
 193                 for (l = ipq.ip_link.next; l != &ipq.ip_link; l = l->next) {
 194             fp = container_of(l, struct ipq, ip_link);
 195             if (ip->ip_id == fp->ipq_id &&
 196                     ip->ip_src.s_addr == fp->ipq_src.s_addr &&
 197                     ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
 198                     ip->ip_p == fp->ipq_p)
 199                     goto found;
 200         }
 201         fp = NULL;
 202         found:
 203
 204                 /*
 205                  * Adjust ip_len to not reflect header,
 206                  * set ip_mff if more fragments are expected,
 207                  * convert offset of this to bytes.
 208                  */
 209                 ip->ip_len -= hlen;
 210                 if (ip->ip_off & IP_MF)
 211                   ip->ip_tos |= 1;
 212                 else
 213                   ip->ip_tos &= ~1;
 214
 215                 ip->ip_off <<= 3;
 216
 217                 /*
 218                  * If datagram marked as having more fragments
 219                  * or if this is not the first fragment,
 220                  * attempt reassembly; if it succeeds, proceed.
 221                  */
 222                 if (ip->ip_tos & 1 || ip->ip_off) {
 223                         STAT(ipstat.ips_fragments++);
 224                         ip = ip_reass(ip, fp);
 225                         if (ip == 0)
 226                                 return;
 227                         STAT(ipstat.ips_reassembled++);
 228                         m = dtom(ip);
 229                 } else
 230                         if (fp)
 231                            ip_freef(fp);
 232
 233         } else
 234                 ip->ip_len -= hlen;
 235
 236         /*
 237          * Switch out to protocol's input routine.
 238          */
 239         STAT(ipstat.ips_delivered++);
 240         switch (ip->ip_p) {
 241          case IPPROTO_TCP:
 242                 tcp_input(m, hlen, (struct socket *)NULL);
 243                 break;
 244          case IPPROTO_UDP:
 245                 udp_input(m, hlen);
 246                 break;
 247          case IPPROTO_ICMP:
 248                 icmp_input(m, hlen);
 249                 break;
 250          default:
 251                 STAT(ipstat.ips_noproto++);
 252                 m_free(m);
 253         }
 254         return;
 255 bad:
 256         m_freem(m);
 257         return;
 258 }
 259
 260 #define iptofrag(P) ((struct ipasfrag *)(((char*)(P)) - sizeof(struct qlink)))
 261 #define fragtoip(P) ((struct ip*)(((char*)(P)) + sizeof(struct qlink)))
 262 /*
 263  * Take incoming datagram fragment and try to
 264  * reassemble it into whole datagram.  If a chain for
 265  * reassembly of this datagram already exists, then it
 266  * is given as fp; otherwise have to make a chain.
 267  */
 268 static struct ip *
 269 ip_reass(register struct ip *ip, register struct ipq *fp)
 270 {
 271         register struct mbuf *m = dtom(ip);
 272         register struct ipasfrag *q;
 273         int hlen = ip->ip_hl << 2;
 274         int i, next;
 275
 276         DEBUG_CALL("ip_reass");
 277         DEBUG_ARG("ip = %lx", (long)ip);
 278         DEBUG_ARG("fp = %lx", (long)fp);
 279         DEBUG_ARG("m = %lx", (long)m);
 280
 281         /*
 282          * Presence of header sizes in mbufs
 283          * would confuse code below.
 284          * Fragment m_data is concatenated.
 285          */
 286         m->m_data += hlen;
 287         m->m_len -= hlen;
 288
 289         /*
 290          * If first fragment to arrive, create a reassembly queue.
 291          */
 292         if (fp == 0) {
 293           struct mbuf *t;
 294           if ((t = m_get()) == NULL) goto dropfrag;
 295           fp = mtod(t, struct ipq *);
 296           insque(&fp->ip_link, &ipq.ip_link);
 297           fp->ipq_ttl = IPFRAGTTL;
 298           fp->ipq_p = ip->ip_p;
 299           fp->ipq_id = ip->ip_id;
 300           fp->frag_link.next = fp->frag_link.prev = &fp->frag_link;
 301           fp->ipq_src = ip->ip_src;
 302           fp->ipq_dst = ip->ip_dst;
 303           q = (struct ipasfrag *)fp;
 304           goto insert;
 305         }
 306
 307         /*
 308          * Find a segment which begins after this one does.
 309          */
 310         for (q = fp->frag_link.next; q != (struct ipasfrag *)&fp->frag_link;
 311             q = q->ipf_next)
 312                 if (q->ipf_off > ip->ip_off)
 313                         break;
 314
 315         /*
 316          * If there is a preceding segment, it may provide some of
 317          * our data already.  If so, drop the data from the incoming
 318          * segment.  If it provides all of our data, drop us.
 319          */
 320         if (q->ipf_prev != &fp->frag_link) {
 321         struct ipasfrag *pq = q->ipf_prev;
 322                 i = pq->ipf_off + pq->ipf_len - ip->ip_off;
 323                 if (i > 0) {
 324                         if (i >= ip->ip_len)
 325                                 goto dropfrag;
 326                         m_adj(dtom(ip), i);
 327                         ip->ip_off += i;
 328                         ip->ip_len -= i;
 329                 }
 330         }
 331
 332         /*
 333          * While we overlap succeeding segments trim them or,
 334          * if they are completely covered, dequeue them.
 335          */
 336         while (q != (struct ipasfrag*)&fp->frag_link &&
 337             ip->ip_off + ip->ip_len > q->ipf_off) {
 338                 i = (ip->ip_off + ip->ip_len) - q->ipf_off;
 339                 if (i < q->ipf_len) {
 340                         q->ipf_len -= i;
 341                         q->ipf_off += i;
 342                         m_adj(dtom(q), i);
 343                         break;
 344                 }
 345                 q = q->ipf_next;
 346                 m_freem(dtom(q->ipf_prev));
 347                 ip_deq(q->ipf_prev);
 348         }
 349
 350 insert:
 351         /*
 352          * Stick new segment in its place;
 353          * check for complete reassembly.
 354          */
 355         ip_enq(iptofrag(ip), q->ipf_prev);
 356         next = 0;
 357         for (q = fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link;
 358             q = q->ipf_next) {
 359                 if (q->ipf_off != next)
 360                         return (0);
 361                 next += q->ipf_len;
 362         }
 363         if (((struct ipasfrag *)(q->ipf_prev))->ipf_tos & 1)
 364                 return (0);
 365
 366         /*
 367          * Reassembly is complete; concatenate fragments.
 368          */
 369     q = fp->frag_link.next;
 370         m = dtom(q);
 371
 372         q = (struct ipasfrag *) q->ipf_next;
 373         while (q != (struct ipasfrag*)&fp->frag_link) {
 374           struct mbuf *t = dtom(q);
 375           q = (struct ipasfrag *) q->ipf_next;
 376           m_cat(m, t);
 377         }
 378
 379         /*
 380          * Create header for new ip packet by
 381          * modifying header of first packet;
 382          * dequeue and discard fragment reassembly header.
 383          * Make header visible.
 384          */
 385         q = fp->frag_link.next;
 386
 387         /*
 388          * If the fragments concatenated to an mbuf that's
 389          * bigger than the total size of the fragment, then and
 390          * m_ext buffer was alloced. But fp->ipq_next points to
 391          * the old buffer (in the mbuf), so we must point ip
 392          * into the new buffer.
 393          */
 394         if (m->m_flags & M_EXT) {
 395           int delta;
 396           delta = (char *)ip - m->m_dat;
 397           q = (struct ipasfrag *)(m->m_ext + delta);
 398         }
 399
 400         /* DEBUG_ARG("ip = %lx", (long)ip);
 401          * ip=(struct ipasfrag *)m->m_data; */
 402
 403     ip = fragtoip(q);
 404         ip->ip_len = next;
 405         ip->ip_tos &= ~1;
 406         ip->ip_src = fp->ipq_src;
 407         ip->ip_dst = fp->ipq_dst;
 408         remque(&fp->ip_link);
 409         (void) m_free(dtom(fp));
 410         m->m_len += (ip->ip_hl << 2);
 411         m->m_data -= (ip->ip_hl << 2);
 412
 413         return ip;
 414
 415 dropfrag:
 416         STAT(ipstat.ips_fragdropped++);
 417         m_freem(m);
 418         return (0);
 419 }
 420
 421 /*
 422  * Free a fragment reassembly header and all
 423  * associated datagrams.
 424  */
 425 static void
 426 ip_freef(struct ipq *fp)
 427 {
 428         register struct ipasfrag *q, *p;
 429
 430         for (q = fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link; q = p) {
 431                 p = q->ipf_next;
 432                 ip_deq(q);
 433                 m_freem(dtom(q));
 434         }
 435         remque(&fp->ip_link);
 436         (void) m_free(dtom(fp));
 437 }
 438
 439 /*
 440  * Put an ip fragment on a reassembly chain.
 441  * Like insque, but pointers in middle of structure.
 442  */
 443 static void
 444 ip_enq(register struct ipasfrag *p, register struct ipasfrag *prev)
 445 {
 446         DEBUG_CALL("ip_enq");
 447         DEBUG_ARG("prev = %lx", (long)prev);
 448         p->ipf_prev =  prev;
 449         p->ipf_next = prev->ipf_next;
 450         ((struct ipasfrag *)(prev->ipf_next))->ipf_prev = p;
 451         prev->ipf_next = p;
 452 }
 453
 454 /*
 455  * To ip_enq as remque is to insque.
 456  */
 457 static void
 458 ip_deq(register struct ipasfrag *p)
 459 {
 460         ((struct ipasfrag *)(p->ipf_prev))->ipf_next = p->ipf_next;
 461         ((struct ipasfrag *)(p->ipf_next))->ipf_prev = p->ipf_prev;
 462 }
 463
 464 /*
 465  * IP timer processing;
 466  * if a timer expires on a reassembly
 467  * queue, discard it.
 468  */
 469 void
 470 ip_slowtimo()
 471 {
 472     struct qlink *l;
 473
 474         DEBUG_CALL("ip_slowtimo");
 475
 476     l = ipq.ip_link.next;
 477
 478         if (l == 0)
 479            return;
 480
 481         while (l != &ipq.ip_link) {
 482         struct ipq *fp = container_of(l, struct ipq, ip_link);
 483         l = l->next;
 484                 if (--fp->ipq_ttl == 0) {
 485                         STAT(ipstat.ips_fragtimeout++);
 486                         ip_freef(fp);
 487                 }
 488         }
 489 }
 490
 491 /*
 492  * Do option processing on a datagram,
 493  * possibly discarding it if bad options are encountered,
 494  * or forwarding it if source-routed.
 495  * Returns 1 if packet has been forwarded/freed,
 496  * 0 if the packet should be processed further.
 497  */
 498
 499 #ifdef notdef
 500
 501 int
 502 ip_dooptions(m)
 503         struct mbuf *m;
 504 {
 505         register struct ip *ip = mtod(m, struct ip *);
 506         register u_char *cp;
 507         register struct ip_timestamp *ipt;
 508         register struct in_ifaddr *ia;
 509 /*      int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; */
 510         int opt, optlen, cnt, off, code, type, forward = 0;
 511         struct in_addr *sin, dst;
 512 typedef u_int32_t n_time;
 513         n_time ntime;
 514
 515         dst = ip->ip_dst;
 516         cp = (u_char *)(ip + 1);
 517         cnt = (ip->ip_hl << 2) - sizeof (struct ip);
 518         for (; cnt > 0; cnt -= optlen, cp += optlen) {
 519                 opt = cp[IPOPT_OPTVAL];
 520                 if (opt == IPOPT_EOL)
 521                         break;
 522                 if (opt == IPOPT_NOP)
 523                         optlen = 1;
 524                 else {
 525                         optlen = cp[IPOPT_OLEN];
 526                         if (optlen <= 0 || optlen > cnt) {
 527                                 code = &cp[IPOPT_OLEN] - (u_char *)ip;
 528                                 goto bad;
 529                         }
 530                 }
 531                 switch (opt) {
 532
 533                 default:
 534                         break;
 535
 536                 /*
 537                  * Source routing with record.
 538                  * Find interface with current destination address.
 539                  * If none on this machine then drop if strictly routed,
 540                  * or do nothing if loosely routed.
 541                  * Record interface address and bring up next address
 542                  * component.  If strictly routed make sure next
 543                  * address is on directly accessible net.
 544                  */
 545                 case IPOPT_LSRR:
 546                 case IPOPT_SSRR:
 547                         if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
 548                                 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
 549                                 goto bad;
 550                         }
 551                         ipaddr.sin_addr = ip->ip_dst;
 552                         ia = (struct in_ifaddr *)
 553                                 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
 554                         if (ia == 0) {
 555                                 if (opt == IPOPT_SSRR) {
 556                                         type = ICMP_UNREACH;
 557                                         code = ICMP_UNREACH_SRCFAIL;
 558                                         goto bad;
 559                                 }
 560                                 /*
 561                                  * Loose routing, and not at next destination
 562                                  * yet; nothing to do except forward.
 563                                  */
 564                                 break;
 565                         }
 566                         off--;                  / * 0 origin *  /
 567                         if (off > optlen - sizeof(struct in_addr)) {
 568                                 /*
 569                                  * End of source route.  Should be for us.
 570                                  */
 571                                 save_rte(cp, ip->ip_src);
 572                                 break;
 573                         }
 574                         /*
 575                          * locate outgoing interface
 576                          */
 577                         bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
 578                             sizeof(ipaddr.sin_addr));
 579                         if (opt == IPOPT_SSRR) {
 580 #define INA     struct in_ifaddr *
 581 #define SA      struct sockaddr *
 582                             if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
 583                                 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
 584                         } else
 585                                 ia = ip_rtaddr(ipaddr.sin_addr);
 586                         if (ia == 0) {
 587                                 type = ICMP_UNREACH;
 588                                 code = ICMP_UNREACH_SRCFAIL;
 589                                 goto bad;
 590                         }
 591                         ip->ip_dst = ipaddr.sin_addr;
 592                         bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
 593                             (caddr_t)(cp + off), sizeof(struct in_addr));
 594                         cp[IPOPT_OFFSET] += sizeof(struct in_addr);
 595                         /*
 596                          * Let ip_intr's mcast routing check handle mcast pkts
 597                          */
 598                         forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
 599                         break;
 600
 601                 case IPOPT_RR:
 602                         if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
 603                                 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
 604                                 goto bad;
 605                         }
 606                         /*
 607                          * If no space remains, ignore.
 608                          */
 609                         off--;                   * 0 origin *
 610                         if (off > optlen - sizeof(struct in_addr))
 611                                 break;
 612                         bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
 613                             sizeof(ipaddr.sin_addr));
 614                         /*
 615                          * locate outgoing interface; if we're the destination,
 616                          * use the incoming interface (should be same).
 617                          */
 618                         if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
 619                             (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
 620                                 type = ICMP_UNREACH;
 621                                 code = ICMP_UNREACH_HOST;
 622                                 goto bad;
 623                         }
 624                         bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
 625                             (caddr_t)(cp + off), sizeof(struct in_addr));
 626                         cp[IPOPT_OFFSET] += sizeof(struct in_addr);
 627                         break;
 628
 629                 case IPOPT_TS:
 630                         code = cp - (u_char *)ip;
 631                         ipt = (struct ip_timestamp *)cp;
 632                         if (ipt->ipt_len < 5)
 633                                 goto bad;
 634                         if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
 635                                 if (++ipt->ipt_oflw == 0)
 636                                         goto bad;
 637                                 break;
 638                         }
 639                         sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
 640                         switch (ipt->ipt_flg) {
 641
 642                         case IPOPT_TS_TSONLY:
 643                                 break;
 644
 645                         case IPOPT_TS_TSANDADDR:
 646                                 if (ipt->ipt_ptr + sizeof(n_time) +
 647                                     sizeof(struct in_addr) > ipt->ipt_len)
 648                                         goto bad;
 649                                 ipaddr.sin_addr = dst;
 650                                 ia = (INA)ifaof_ i f p foraddr((SA)&ipaddr,
 651                                                             m->m_pkthdr.rcvif);
 652                                 if (ia == 0)
 653                                         continue;
 654                                 bcopy((caddr_t)&IA_SIN(ia)->sin_addr,
 655                                     (caddr_t)sin, sizeof(struct in_addr));
 656                                 ipt->ipt_ptr += sizeof(struct in_addr);
 657                                 break;
 658
 659                         case IPOPT_TS_PRESPEC:
 660                                 if (ipt->ipt_ptr + sizeof(n_time) +
 661                                     sizeof(struct in_addr) > ipt->ipt_len)
 662                                         goto bad;
 663                                 bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
 664                                     sizeof(struct in_addr));
 665                                 if (ifa_ifwithaddr((SA)&ipaddr) == 0)
 666                                         continue;
 667                                 ipt->ipt_ptr += sizeof(struct in_addr);
 668                                 break;
 669
 670                         default:
 671                                 goto bad;
 672                         }
 673                         ntime = iptime();
 674                         bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
 675                             sizeof(n_time));
 676                         ipt->ipt_ptr += sizeof(n_time);
 677                 }
 678         }
 679         if (forward) {
 680                 ip_forward(m, 1);
 681                 return (1);
 682         }
 683                 }
 684         }
 685         return (0);
 686 bad:
 687         /* ip->ip_len -= ip->ip_hl << 2;   XXX icmp_error adds in hdr length */
 688
 689 /* Not yet */
 690         icmp_error(m, type, code, 0, 0);
 691
 692         STAT(ipstat.ips_badoptions++);
 693         return (1);
 694 }
 695
 696 #endif /* notdef */
 697
 698 /*
 699  * Strip out IP options, at higher
 700  * level protocol in the kernel.
 701  * Second argument is buffer to which options
 702  * will be moved, and return value is their length.
 703  * (XXX) should be deleted; last arg currently ignored.
 704  */
 705 void
 706 ip_stripoptions(m, mopt)
 707         register struct mbuf *m;
 708         struct mbuf *mopt;
 709 {
 710         register int i;
 711         struct ip *ip = mtod(m, struct ip *);
 712         register caddr_t opts;
 713         int olen;
 714
 715         olen = (ip->ip_hl<<2) - sizeof (struct ip);
 716         opts = (caddr_t)(ip + 1);
 717         i = m->m_len - (sizeof (struct ip) + olen);
 718         memcpy(opts, opts  + olen, (unsigned)i);
 719         m->m_len -= olen;
 720
 721         ip->ip_hl = sizeof(struct ip) >> 2;
 722 }