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