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 <osdep.h>
  47 #include "ip_icmp.h"
  48
  49 #ifdef LOG_ENABLED
  50 struct ipstat ipstat;
  51 #endif
  52
  53 struct ipq ipq;
  54
  55 static struct ip *ip_reass(register struct ip *ip,
  56                            register struct ipq *fp);
  57 static void ip_freef(struct ipq *fp);
  58 static void ip_enq(register struct ipasfrag *p,
  59                    register struct ipasfrag *prev);
  60 static void ip_deq(register struct ipasfrag *p);
  61
  62 /*
  63  * IP initialization: fill in IP protocol switch table.
  64  * All protocols not implemented in kernel go to raw IP protocol handler.
  65  */
  66 void
  67 ip_init()
  68 {
  69         ipq.ip_link.next = ipq.ip_link.prev = &ipq.ip_link;
  70         ip_id = tt.tv_sec & 0xffff;
  71         udp_init();
  72         tcp_init();
  73 }
  74
  75 /*
  76  * Ip input routine.  Checksum and byte swap header.  If fragmented
  77  * try to reassemble.  Process options.  Pass to next level.
  78  */
  79 void
  80 ip_input(m)
  81         struct mbuf *m;
  82 {
  83         register struct ip *ip;
  84         int hlen;
  85
  86         DEBUG_CALL("ip_input");
  87         DEBUG_ARG("m = %lx", (long)m);
  88         DEBUG_ARG("m_len = %d", m->m_len);
  89
  90         STAT(ipstat.ips_total++);
  91
  92         if (m->m_len < sizeof (struct ip)) {
  93                 STAT(ipstat.ips_toosmall++);
  94                 return;
  95         }
  96
  97         ip = mtod(m, struct ip *);
  98
  99         if (ip->ip_v != IPVERSION) {
 100                 STAT(ipstat.ips_badvers++);
 101                 goto bad;
 102         }
 103
 104         hlen = ip->ip_hl << 2;
 105         if (hlen<sizeof(struct ip ) || hlen>m->m_len) {/* min header length */
 106           STAT(ipstat.ips_badhlen++);                     /* or packet too short */
 107           goto bad;
 108         }
 109
 110         /* keep ip header intact for ICMP reply
 111          * ip->ip_sum = cksum(m, hlen);
 112          * if (ip->ip_sum) {
 113          */
 114         if(cksum(m,hlen)) {
 115           STAT(ipstat.ips_badsum++);
 116           goto bad;
 117         }
 118
 119         /*
 120          * Convert fields to host representation.
 121          */
 122         NTOHS(ip->ip_len);
 123         if (ip->ip_len < hlen) {
 124                 STAT(ipstat.ips_badlen++);
 125                 goto bad;
 126         }
 127         NTOHS(ip->ip_id);
 128         NTOHS(ip->ip_off);
 129
 130         /*
 131          * Check that the amount of data in the buffers
 132          * is as at least much as the IP header would have us expect.
 133          * Trim mbufs if longer than we expect.
 134          * Drop packet if shorter than we expect.
 135          */
 136         if (m->m_len < ip->ip_len) {
 137                 STAT(ipstat.ips_tooshort++);
 138                 goto bad;
 139         }
 140
 141     if (slirp_restrict) {
 142         if (memcmp(&ip->ip_dst.s_addr, &special_addr, 3)) {
 143             if (ip->ip_dst.s_addr == 0xffffffff && ip->ip_p != IPPROTO_UDP)
 144                 goto bad;
 145         } else {
 146             int host = ntohl(ip->ip_dst.s_addr) & 0xff;
 147             struct ex_list *ex_ptr;
 148
 149             if (host == 0xff)
 150                 goto bad;
 151
 152             for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
 153                 if (ex_ptr->ex_addr == host)
 154                     break;
 155
 156             if (!ex_ptr)
 157                 goto bad;
 158         }
 159     }
 160
 161         /* Should drop packet if mbuf too long? hmmm... */
 162         if (m->m_len > ip->ip_len)
 163            m_adj(m, ip->ip_len - m->m_len);
 164
 165         /* check ip_ttl for a correct ICMP reply */
 166         if(ip->ip_ttl==0 || ip->ip_ttl==1) {
 167           icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");
 168           goto bad;
 169         }
 170
 171         /*
 172          * Process options and, if not destined for us,
 173          * ship it on.  ip_dooptions returns 1 when an
 174          * error was detected (causing an icmp message
 175          * to be sent and the original packet to be freed).
 176          */
 177 /* We do no IP options */
 178 /*      if (hlen > sizeof (struct ip) && ip_dooptions(m))
 179  *              goto next;
 180  */
 181         /*
 182          * If offset or IP_MF are set, must reassemble.
 183          * Otherwise, nothing need be done.
 184          * (We could look in the reassembly queue to see
 185          * if the packet was previously fragmented,
 186          * but it's not worth the time; just let them time out.)
 187          *
 188          * XXX This should fail, don't fragment yet
 189          */
 190         if (ip->ip_off &~ IP_DF) {
 191           register struct ipq *fp;
 192       struct qlink *l;
 193                 /*
 194                  * Look for queue of fragments
 195                  * of this datagram.
 196                  */
 197                 for (l = ipq.ip_link.next; l != &ipq.ip_link; l = l->next) {
 198             fp = container_of(l, struct ipq, ip_link);
 199             if (ip->ip_id == fp->ipq_id &&
 200                     ip->ip_src.s_addr == fp->ipq_src.s_addr &&
 201                     ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
 202                     ip->ip_p == fp->ipq_p)
 203                     goto found;
 204         }
 205         fp = NULL;
 206         found:
 207
 208                 /*
 209                  * Adjust ip_len to not reflect header,
 210                  * set ip_mff if more fragments are expected,
 211                  * convert offset of this to bytes.
 212                  */
 213                 ip->ip_len -= hlen;
 214                 if (ip->ip_off & IP_MF)
 215                   ip->ip_tos |= 1;
 216                 else
 217                   ip->ip_tos &= ~1;
 218
 219                 ip->ip_off <<= 3;
 220
 221                 /*
 222                  * If datagram marked as having more fragments
 223                  * or if this is not the first fragment,
 224                  * attempt reassembly; if it succeeds, proceed.
 225                  */
 226                 if (ip->ip_tos & 1 || ip->ip_off) {
 227                         STAT(ipstat.ips_fragments++);
 228                         ip = ip_reass(ip, fp);
 229                         if (ip == 0)
 230                                 return;
 231                         STAT(ipstat.ips_reassembled++);
 232                         m = dtom(ip);
 233                 } else
 234                         if (fp)
 235                            ip_freef(fp);
 236
 237         } else
 238                 ip->ip_len -= hlen;
 239
 240         /*
 241          * Switch out to protocol's input routine.
 242          */
 243         STAT(ipstat.ips_delivered++);
 244         switch (ip->ip_p) {
 245          case IPPROTO_TCP:
 246                 tcp_input(m, hlen, (struct socket *)NULL);
 247                 break;
 248          case IPPROTO_UDP:
 249                 udp_input(m, hlen);
 250                 break;
 251          case IPPROTO_ICMP:
 252                 icmp_input(m, hlen);
 253                 break;
 254          default:
 255                 STAT(ipstat.ips_noproto++);
 256                 m_free(m);
 257         }
 258         return;
 259 bad:
 260         m_freem(m);
 261         return;
 262 }
 263
 264 #define iptofrag(P) ((struct ipasfrag *)(((char*)(P)) - sizeof(struct qlink)))
 265 #define fragtoip(P) ((struct ip*)(((char*)(P)) + sizeof(struct qlink)))
 266 /*
 267  * Take incoming datagram fragment and try to
 268  * reassemble it into whole datagram.  If a chain for
 269  * reassembly of this datagram already exists, then it
 270  * is given as fp; otherwise have to make a chain.
 271  */
 272 static struct ip *
 273 ip_reass(register struct ip *ip, register struct ipq *fp)
 274 {
 275         register struct mbuf *m = dtom(ip);
 276         register struct ipasfrag *q;
 277         int hlen = ip->ip_hl << 2;
 278         int i, next;
 279
 280         DEBUG_CALL("ip_reass");
 281         DEBUG_ARG("ip = %lx", (long)ip);
 282         DEBUG_ARG("fp = %lx", (long)fp);
 283         DEBUG_ARG("m = %lx", (long)m);
 284
 285         /*
 286          * Presence of header sizes in mbufs
 287          * would confuse code below.
 288          * Fragment m_data is concatenated.
 289          */
 290         m->m_data += hlen;
 291         m->m_len -= hlen;
 292
 293         /*
 294          * If first fragment to arrive, create a reassembly queue.
 295          */
 296         if (fp == 0) {
 297           struct mbuf *t;
 298           if ((t = m_get()) == NULL) goto dropfrag;
 299           fp = mtod(t, struct ipq *);
 300           insque(&fp->ip_link, &ipq.ip_link);
 301           fp->ipq_ttl = IPFRAGTTL;
 302           fp->ipq_p = ip->ip_p;
 303           fp->ipq_id = ip->ip_id;
 304           fp->frag_link.next = fp->frag_link.prev = &fp->frag_link;
 305           fp->ipq_src = ip->ip_src;
 306           fp->ipq_dst = ip->ip_dst;
 307           q = (struct ipasfrag *)fp;
 308           goto insert;
 309         }
 310
 311         /*
 312          * Find a segment which begins after this one does.
 313          */
 314         for (q = fp->frag_link.next; q != (struct ipasfrag *)&fp->frag_link;
 315             q = q->ipf_next)
 316                 if (q->ipf_off > ip->ip_off)
 317                         break;
 318
 319         /*
 320          * If there is a preceding segment, it may provide some of
 321          * our data already.  If so, drop the data from the incoming
 322          * segment.  If it provides all of our data, drop us.
 323          */
 324         if (q->ipf_prev != &fp->frag_link) {
 325         struct ipasfrag *pq = q->ipf_prev;
 326                 i = pq->ipf_off + pq->ipf_len - ip->ip_off;
 327                 if (i > 0) {
 328                         if (i >= ip->ip_len)
 329                                 goto dropfrag;
 330                         m_adj(dtom(ip), i);
 331                         ip->ip_off += i;
 332                         ip->ip_len -= i;
 333                 }
 334         }
 335
 336         /*
 337          * While we overlap succeeding segments trim them or,
 338          * if they are completely covered, dequeue them.
 339          */
 340         while (q != (struct ipasfrag*)&fp->frag_link &&
 341             ip->ip_off + ip->ip_len > q->ipf_off) {
 342                 i = (ip->ip_off + ip->ip_len) - q->ipf_off;
 343                 if (i < q->ipf_len) {
 344                         q->ipf_len -= i;
 345                         q->ipf_off += i;
 346                         m_adj(dtom(q), i);
 347                         break;
 348                 }
 349                 q = q->ipf_next;
 350                 m_freem(dtom(q->ipf_prev));
 351                 ip_deq(q->ipf_prev);
 352         }
 353
 354 insert:
 355         /*
 356          * Stick new segment in its place;
 357          * check for complete reassembly.
 358          */
 359         ip_enq(iptofrag(ip), q->ipf_prev);
 360         next = 0;
 361         for (q = fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link;
 362             q = q->ipf_next) {
 363                 if (q->ipf_off != next)
 364                         return (0);
 365                 next += q->ipf_len;
 366         }
 367         if (((struct ipasfrag *)(q->ipf_prev))->ipf_tos & 1)
 368                 return (0);
 369
 370         /*
 371          * Reassembly is complete; concatenate fragments.
 372          */
 373     q = fp->frag_link.next;
 374         m = dtom(q);
 375
 376         q = (struct ipasfrag *) q->ipf_next;
 377         while (q != (struct ipasfrag*)&fp->frag_link) {
 378           struct mbuf *t = dtom(q);
 379           q = (struct ipasfrag *) q->ipf_next;
 380           m_cat(m, t);
 381         }
 382
 383         /*
 384          * Create header for new ip packet by
 385          * modifying header of first packet;
 386          * dequeue and discard fragment reassembly header.
 387          * Make header visible.
 388          */
 389         q = fp->frag_link.next;
 390
 391         /*
 392          * If the fragments concatenated to an mbuf that's
 393          * bigger than the total size of the fragment, then and
 394          * m_ext buffer was alloced. But fp->ipq_next points to
 395          * the old buffer (in the mbuf), so we must point ip
 396          * into the new buffer.
 397          */
 398         if (m->m_flags & M_EXT) {
 399           int delta;
 400           delta = (char *)ip - m->m_dat;
 401           q = (struct ipasfrag *)(m->m_ext + delta);
 402         }
 403
 404         /* DEBUG_ARG("ip = %lx", (long)ip);
 405          * ip=(struct ipasfrag *)m->m_data; */
 406
 407     ip = fragtoip(q);
 408         ip->ip_len = next;
 409         ip->ip_tos &= ~1;
 410         ip->ip_src = fp->ipq_src;
 411         ip->ip_dst = fp->ipq_dst;
 412         remque(&fp->ip_link);
 413         (void) m_free(dtom(fp));
 414         m->m_len += (ip->ip_hl << 2);
 415         m->m_data -= (ip->ip_hl << 2);
 416
 417         return ip;
 418
 419 dropfrag:
 420         STAT(ipstat.ips_fragdropped++);
 421         m_freem(m);
 422         return (0);
 423 }
 424
 425 /*
 426  * Free a fragment reassembly header and all
 427  * associated datagrams.
 428  */
 429 static void
 430 ip_freef(struct ipq *fp)
 431 {
 432         register struct ipasfrag *q, *p;
 433
 434         for (q = fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link; q = p) {
 435                 p = q->ipf_next;
 436                 ip_deq(q);
 437                 m_freem(dtom(q));
 438         }
 439         remque(&fp->ip_link);
 440         (void) m_free(dtom(fp));
 441 }
 442
 443 /*
 444  * Put an ip fragment on a reassembly chain.
 445  * Like insque, but pointers in middle of structure.
 446  */
 447 static void
 448 ip_enq(register struct ipasfrag *p, register struct ipasfrag *prev)
 449 {
 450         DEBUG_CALL("ip_enq");
 451         DEBUG_ARG("prev = %lx", (long)prev);
 452         p->ipf_prev =  prev;
 453         p->ipf_next = prev->ipf_next;
 454         ((struct ipasfrag *)(prev->ipf_next))->ipf_prev = p;
 455         prev->ipf_next = p;
 456 }
 457
 458 /*
 459  * To ip_enq as remque is to insque.
 460  */
 461 static void
 462 ip_deq(register struct ipasfrag *p)
 463 {
 464         ((struct ipasfrag *)(p->ipf_prev))->ipf_next = p->ipf_next;
 465         ((struct ipasfrag *)(p->ipf_next))->ipf_prev = p->ipf_prev;
 466 }
 467
 468 /*
 469  * IP timer processing;
 470  * if a timer expires on a reassembly
 471  * queue, discard it.
 472  */
 473 void
 474 ip_slowtimo()
 475 {
 476     struct qlink *l;
 477
 478         DEBUG_CALL("ip_slowtimo");
 479
 480     l = ipq.ip_link.next;
 481
 482         if (l == 0)
 483            return;
 484
 485         while (l != &ipq.ip_link) {
 486         struct ipq *fp = container_of(l, struct ipq, ip_link);
 487         l = l->next;
 488                 if (--fp->ipq_ttl == 0) {
 489                         STAT(ipstat.ips_fragtimeout++);
 490                         ip_freef(fp);
 491                 }
 492         }
 493 }
 494
 495 /*
 496  * Do option processing on a datagram,
 497  * possibly discarding it if bad options are encountered,
 498  * or forwarding it if source-routed.
 499  * Returns 1 if packet has been forwarded/freed,
 500  * 0 if the packet should be processed further.
 501  */
 502
 503 #ifdef notdef
 504
 505 int
 506 ip_dooptions(m)
 507         struct mbuf *m;
 508 {
 509         register struct ip *ip = mtod(m, struct ip *);
 510         register u_char *cp;
 511         register struct ip_timestamp *ipt;
 512         register struct in_ifaddr *ia;
 513 /*      int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; */
 514         int opt, optlen, cnt, off, code, type, forward = 0;
 515         struct in_addr *sin, dst;
 516 typedef u_int32_t n_time;
 517         n_time ntime;
 518
 519         dst = ip->ip_dst;
 520         cp = (u_char *)(ip + 1);
 521         cnt = (ip->ip_hl << 2) - sizeof (struct ip);
 522         for (; cnt > 0; cnt -= optlen, cp += optlen) {
 523                 opt = cp[IPOPT_OPTVAL];
 524                 if (opt == IPOPT_EOL)
 525                         break;
 526                 if (opt == IPOPT_NOP)
 527                         optlen = 1;
 528                 else {
 529                         optlen = cp[IPOPT_OLEN];
 530                         if (optlen <= 0 || optlen > cnt) {
 531                                 code = &cp[IPOPT_OLEN] - (u_char *)ip;
 532                                 goto bad;
 533                         }
 534                 }
 535                 switch (opt) {
 536
 537                 default:
 538                         break;
 539
 540                 /*
 541                  * Source routing with record.
 542                  * Find interface with current destination address.
 543                  * If none on this machine then drop if strictly routed,
 544                  * or do nothing if loosely routed.
 545                  * Record interface address and bring up next address
 546                  * component.  If strictly routed make sure next
 547                  * address is on directly accessible net.
 548                  */
 549                 case IPOPT_LSRR:
 550                 case IPOPT_SSRR:
 551                         if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
 552                                 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
 553                                 goto bad;
 554                         }
 555                         ipaddr.sin_addr = ip->ip_dst;
 556                         ia = (struct in_ifaddr *)
 557                                 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
 558                         if (ia == 0) {
 559                                 if (opt == IPOPT_SSRR) {
 560                                         type = ICMP_UNREACH;
 561                                         code = ICMP_UNREACH_SRCFAIL;
 562                                         goto bad;
 563                                 }
 564                                 /*
 565                                  * Loose routing, and not at next destination
 566                                  * yet; nothing to do except forward.
 567                                  */
 568                                 break;
 569                         }
 570                         off--;                  / * 0 origin *  /
 571                         if (off > optlen - sizeof(struct in_addr)) {
 572                                 /*
 573                                  * End of source route.  Should be for us.
 574                                  */
 575                                 save_rte(cp, ip->ip_src);
 576                                 break;
 577                         }
 578                         /*
 579                          * locate outgoing interface
 580                          */
 581                         bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
 582                             sizeof(ipaddr.sin_addr));
 583                         if (opt == IPOPT_SSRR) {
 584 #define INA     struct in_ifaddr *
 585 #define SA      struct sockaddr *
 586                             if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
 587                                 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
 588                         } else
 589                                 ia = ip_rtaddr(ipaddr.sin_addr);
 590                         if (ia == 0) {
 591                                 type = ICMP_UNREACH;
 592                                 code = ICMP_UNREACH_SRCFAIL;
 593                                 goto bad;
 594                         }
 595                         ip->ip_dst = ipaddr.sin_addr;
 596                         bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
 597                             (caddr_t)(cp + off), sizeof(struct in_addr));
 598                         cp[IPOPT_OFFSET] += sizeof(struct in_addr);
 599                         /*
 600                          * Let ip_intr's mcast routing check handle mcast pkts
 601                          */
 602                         forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
 603                         break;
 604
 605                 case IPOPT_RR:
 606                         if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
 607                                 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
 608                                 goto bad;
 609                         }
 610                         /*
 611                          * If no space remains, ignore.
 612                          */
 613                         off--;                   * 0 origin *
 614                         if (off > optlen - sizeof(struct in_addr))
 615                                 break;
 616                         bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
 617                             sizeof(ipaddr.sin_addr));
 618                         /*
 619                          * locate outgoing interface; if we're the destination,
 620                          * use the incoming interface (should be same).
 621                          */
 622                         if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
 623                             (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
 624                                 type = ICMP_UNREACH;
 625                                 code = ICMP_UNREACH_HOST;
 626                                 goto bad;
 627                         }
 628                         bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
 629                             (caddr_t)(cp + off), sizeof(struct in_addr));
 630                         cp[IPOPT_OFFSET] += sizeof(struct in_addr);
 631                         break;
 632
 633                 case IPOPT_TS:
 634                         code = cp - (u_char *)ip;
 635                         ipt = (struct ip_timestamp *)cp;
 636                         if (ipt->ipt_len < 5)
 637                                 goto bad;
 638                         if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
 639                                 if (++ipt->ipt_oflw == 0)
 640                                         goto bad;
 641                                 break;
 642                         }
 643                         sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
 644                         switch (ipt->ipt_flg) {
 645
 646                         case IPOPT_TS_TSONLY:
 647                                 break;
 648
 649                         case IPOPT_TS_TSANDADDR:
 650                                 if (ipt->ipt_ptr + sizeof(n_time) +
 651                                     sizeof(struct in_addr) > ipt->ipt_len)
 652                                         goto bad;
 653                                 ipaddr.sin_addr = dst;
 654                                 ia = (INA)ifaof_ i f p foraddr((SA)&ipaddr,
 655                                                             m->m_pkthdr.rcvif);
 656                                 if (ia == 0)
 657                                         continue;
 658                                 bcopy((caddr_t)&IA_SIN(ia)->sin_addr,
 659                                     (caddr_t)sin, sizeof(struct in_addr));
 660                                 ipt->ipt_ptr += sizeof(struct in_addr);
 661                                 break;
 662
 663                         case IPOPT_TS_PRESPEC:
 664                                 if (ipt->ipt_ptr + sizeof(n_time) +
 665                                     sizeof(struct in_addr) > ipt->ipt_len)
 666                                         goto bad;
 667                                 bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
 668                                     sizeof(struct in_addr));
 669                                 if (ifa_ifwithaddr((SA)&ipaddr) == 0)
 670                                         continue;
 671                                 ipt->ipt_ptr += sizeof(struct in_addr);
 672                                 break;
 673
 674                         default:
 675                                 goto bad;
 676                         }
 677                         ntime = iptime();
 678                         bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
 679                             sizeof(n_time));
 680                         ipt->ipt_ptr += sizeof(n_time);
 681                 }
 682         }
 683         if (forward) {
 684                 ip_forward(m, 1);
 685                 return (1);
 686         }
 687                 }
 688         }
 689         return (0);
 690 bad:
 691         /* ip->ip_len -= ip->ip_hl << 2;   XXX icmp_error adds in hdr length */
 692
 693 /* Not yet */
 694         icmp_error(m, type, code, 0, 0);
 695
 696         STAT(ipstat.ips_badoptions++);
 697         return (1);
 698 }
 699
 700 #endif /* notdef */
 701
 702 /*
 703  * Strip out IP options, at higher
 704  * level protocol in the kernel.
 705  * Second argument is buffer to which options
 706  * will be moved, and return value is their length.
 707  * (XXX) should be deleted; last arg currently ignored.
 708  */
 709 void
 710 ip_stripoptions(m, mopt)
 711         register struct mbuf *m;
 712         struct mbuf *mopt;
 713 {
 714         register int i;
 715         struct ip *ip = mtod(m, struct ip *);
 716         register caddr_t opts;
 717         int olen;
 718
 719         olen = (ip->ip_hl<<2) - sizeof (struct ip);
 720         opts = (caddr_t)(ip + 1);
 721         i = m->m_len - (sizeof (struct ip) + olen);
 722         memcpy(opts, opts  + olen, (unsigned)i);
 723         m->m_len -= olen;
 724
 725         ip->ip_hl = sizeof(struct ip) >> 2;
 726 }