summaryrefslogtreecommitdiff
path: root/slirp/ip_input.c
blob: bb101da1a63daae782567f2c08947204c7504683 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
/*
 * Copyright (c) 1982, 1986, 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)ip_input.c	8.2 (Berkeley) 1/4/94
 * ip_input.c,v 1.11 1994/11/16 10:17:08 jkh Exp
 */

/*
 * Changes and additions relating to SLiRP are
 * Copyright (c) 1995 Danny Gasparovski.
 *
 * Please read the file COPYRIGHT for the
 * terms and conditions of the copyright.
 */

#include <slirp.h>
#include <osdep.h>
#include "ip_icmp.h"

static struct ip *ip_reass(Slirp *slirp, struct ip *ip, struct ipq *fp);
static void ip_freef(Slirp *slirp, struct ipq *fp);
static void ip_enq(register struct ipasfrag *p,
                   register struct ipasfrag *prev);
static void ip_deq(register struct ipasfrag *p);

/*
 * IP initialization: fill in IP protocol switch table.
 * All protocols not implemented in kernel go to raw IP protocol handler.
 */
void
ip_init(Slirp *slirp)
{
    slirp->ipq.ip_link.next = slirp->ipq.ip_link.prev = &slirp->ipq.ip_link;
    udp_init(slirp);
    tcp_init(slirp);
}

/*
 * Ip input routine.  Checksum and byte swap header.  If fragmented
 * try to reassemble.  Process options.  Pass to next level.
 */
void
ip_input(struct mbuf *m)
{
	Slirp *slirp = m->slirp;
	register struct ip *ip;
	int hlen;

	DEBUG_CALL("ip_input");
	DEBUG_ARG("m = %lx", (long)m);
	DEBUG_ARG("m_len = %d", m->m_len);

	if (m->m_len < sizeof (struct ip)) {
		return;
	}

	ip = mtod(m, struct ip *);

	if (ip->ip_v != IPVERSION) {
		goto bad;
	}

	hlen = ip->ip_hl << 2;
	if (hlen<sizeof(struct ip ) || hlen>m->m_len) {/* min header length */
	  goto bad;                                  /* or packet too short */
	}

        /* keep ip header intact for ICMP reply
	 * ip->ip_sum = cksum(m, hlen);
	 * if (ip->ip_sum) {
	 */
	if(cksum(m,hlen)) {
	  goto bad;
	}

	/*
	 * Convert fields to host representation.
	 */
	NTOHS(ip->ip_len);
	if (ip->ip_len < hlen) {
		goto bad;
	}
	NTOHS(ip->ip_id);
	NTOHS(ip->ip_off);

	/*
	 * Check that the amount of data in the buffers
	 * is as at least much as the IP header would have us expect.
	 * Trim mbufs if longer than we expect.
	 * Drop packet if shorter than we expect.
	 */
	if (m->m_len < ip->ip_len) {
		goto bad;
	}

    if (slirp->restricted) {
        if ((ip->ip_dst.s_addr & slirp->vnetwork_mask.s_addr) ==
            slirp->vnetwork_addr.s_addr) {
            if (ip->ip_dst.s_addr == 0xffffffff && ip->ip_p != IPPROTO_UDP)
                goto bad;
        } else {
            uint32_t inv_mask = ~slirp->vnetwork_mask.s_addr;
            struct ex_list *ex_ptr;

            if ((ip->ip_dst.s_addr & inv_mask) == inv_mask) {
                goto bad;
            }
            for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
                if (ex_ptr->ex_addr.s_addr == ip->ip_dst.s_addr)
                    break;

            if (!ex_ptr)
                goto bad;
        }
    }

	/* Should drop packet if mbuf too long? hmmm... */
	if (m->m_len > ip->ip_len)
	   m_adj(m, ip->ip_len - m->m_len);

	/* check ip_ttl for a correct ICMP reply */
	if(ip->ip_ttl==0 || ip->ip_ttl==1) {
	  icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");
	  goto bad;
	}

	/*
	 * If offset or IP_MF are set, must reassemble.
	 * Otherwise, nothing need be done.
	 * (We could look in the reassembly queue to see
	 * if the packet was previously fragmented,
	 * but it's not worth the time; just let them time out.)
	 *
	 * XXX This should fail, don't fragment yet
	 */
	if (ip->ip_off &~ IP_DF) {
	  register struct ipq *fp;
      struct qlink *l;
		/*
		 * Look for queue of fragments
		 * of this datagram.
		 */
		for (l = slirp->ipq.ip_link.next; l != &slirp->ipq.ip_link;
		     l = l->next) {
            fp = container_of(l, struct ipq, ip_link);
            if (ip->ip_id == fp->ipq_id &&
                    ip->ip_src.s_addr == fp->ipq_src.s_addr &&
                    ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
                    ip->ip_p == fp->ipq_p)
		    goto found;
        }
        fp = NULL;
	found:

		/*
		 * Adjust ip_len to not reflect header,
		 * set ip_mff if more fragments are expected,
		 * convert offset of this to bytes.
		 */
		ip->ip_len -= hlen;
		if (ip->ip_off & IP_MF)
		  ip->ip_tos |= 1;
		else
		  ip->ip_tos &= ~1;

		ip->ip_off <<= 3;

		/*
		 * If datagram marked as having more fragments
		 * or if this is not the first fragment,
		 * attempt reassembly; if it succeeds, proceed.
		 */
		if (ip->ip_tos & 1 || ip->ip_off) {
			ip = ip_reass(slirp, ip, fp);
                        if (ip == NULL)
				return;
			m = dtom(slirp, ip);
		} else
			if (fp)
		   	   ip_freef(slirp, fp);

	} else
		ip->ip_len -= hlen;

	/*
	 * Switch out to protocol's input routine.
	 */
	switch (ip->ip_p) {
	 case IPPROTO_TCP:
		tcp_input(m, hlen, (struct socket *)NULL);
		break;
	 case IPPROTO_UDP:
		udp_input(m, hlen);
		break;
	 case IPPROTO_ICMP:
		icmp_input(m, hlen);
		break;
	 default:
		m_free(m);
	}
	return;
bad:
	m_freem(m);
	return;
}

#define iptofrag(P) ((struct ipasfrag *)(((char*)(P)) - sizeof(struct qlink)))
#define fragtoip(P) ((struct ip*)(((char*)(P)) + sizeof(struct qlink)))
/*
 * Take incoming datagram fragment and try to
 * reassemble it into whole datagram.  If a chain for
 * reassembly of this datagram already exists, then it
 * is given as fp; otherwise have to make a chain.
 */
static struct ip *
ip_reass(Slirp *slirp, struct ip *ip, struct ipq *fp)
{
	register struct mbuf *m = dtom(slirp, ip);
	register struct ipasfrag *q;
	int hlen = ip->ip_hl << 2;
	int i, next;

	DEBUG_CALL("ip_reass");
	DEBUG_ARG("ip = %lx", (long)ip);
	DEBUG_ARG("fp = %lx", (long)fp);
	DEBUG_ARG("m = %lx", (long)m);

	/*
	 * Presence of header sizes in mbufs
	 * would confuse code below.
         * Fragment m_data is concatenated.
	 */
	m->m_data += hlen;
	m->m_len -= hlen;

	/*
	 * If first fragment to arrive, create a reassembly queue.
	 */
        if (fp == NULL) {
	  struct mbuf *t = m_get(slirp);

	  if (t == NULL) {
	      goto dropfrag;
	  }
	  fp = mtod(t, struct ipq *);
	  insque(&fp->ip_link, &slirp->ipq.ip_link);
	  fp->ipq_ttl = IPFRAGTTL;
	  fp->ipq_p = ip->ip_p;
	  fp->ipq_id = ip->ip_id;
	  fp->frag_link.next = fp->frag_link.prev = &fp->frag_link;
	  fp->ipq_src = ip->ip_src;
	  fp->ipq_dst = ip->ip_dst;
	  q = (struct ipasfrag *)fp;
	  goto insert;
	}

	/*
	 * Find a segment which begins after this one does.
	 */
	for (q = fp->frag_link.next; q != (struct ipasfrag *)&fp->frag_link;
            q = q->ipf_next)
		if (q->ipf_off > ip->ip_off)
			break;

	/*
	 * If there is a preceding segment, it may provide some of
	 * our data already.  If so, drop the data from the incoming
	 * segment.  If it provides all of our data, drop us.
	 */
	if (q->ipf_prev != &fp->frag_link) {
        struct ipasfrag *pq = q->ipf_prev;
		i = pq->ipf_off + pq->ipf_len - ip->ip_off;
		if (i > 0) {
			if (i >= ip->ip_len)
				goto dropfrag;
			m_adj(dtom(slirp, ip), i);
			ip->ip_off += i;
			ip->ip_len -= i;
		}
	}

	/*
	 * While we overlap succeeding segments trim them or,
	 * if they are completely covered, dequeue them.
	 */
	while (q != (struct ipasfrag*)&fp->frag_link &&
            ip->ip_off + ip->ip_len > q->ipf_off) {
		i = (ip->ip_off + ip->ip_len) - q->ipf_off;
		if (i < q->ipf_len) {
			q->ipf_len -= i;
			q->ipf_off += i;
			m_adj(dtom(slirp, q), i);
			break;
		}
		q = q->ipf_next;
		m_freem(dtom(slirp, q->ipf_prev));
		ip_deq(q->ipf_prev);
	}

insert:
	/*
	 * Stick new segment in its place;
	 * check for complete reassembly.
	 */
	ip_enq(iptofrag(ip), q->ipf_prev);
	next = 0;
	for (q = fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link;
            q = q->ipf_next) {
		if (q->ipf_off != next)
                        return NULL;
		next += q->ipf_len;
	}
	if (((struct ipasfrag *)(q->ipf_prev))->ipf_tos & 1)
                return NULL;

	/*
	 * Reassembly is complete; concatenate fragments.
	 */
    q = fp->frag_link.next;
	m = dtom(slirp, q);

	q = (struct ipasfrag *) q->ipf_next;
	while (q != (struct ipasfrag*)&fp->frag_link) {
	  struct mbuf *t = dtom(slirp, q);
	  q = (struct ipasfrag *) q->ipf_next;
	  m_cat(m, t);
	}

	/*
	 * Create header for new ip packet by
	 * modifying header of first packet;
	 * dequeue and discard fragment reassembly header.
	 * Make header visible.
	 */
	q = fp->frag_link.next;

	/*
	 * If the fragments concatenated to an mbuf that's
	 * bigger than the total size of the fragment, then and
	 * m_ext buffer was alloced. But fp->ipq_next points to
	 * the old buffer (in the mbuf), so we must point ip
	 * into the new buffer.
	 */
	if (m->m_flags & M_EXT) {
	  int delta = (char *)q - m->m_dat;
	  q = (struct ipasfrag *)(m->m_ext + delta);
	}

    ip = fragtoip(q);
	ip->ip_len = next;
	ip->ip_tos &= ~1;
	ip->ip_src = fp->ipq_src;
	ip->ip_dst = fp->ipq_dst;
	remque(&fp->ip_link);
	(void) m_free(dtom(slirp, fp));
	m->m_len += (ip->ip_hl << 2);
	m->m_data -= (ip->ip_hl << 2);

	return ip;

dropfrag:
	m_freem(m);
        return NULL;
}

/*
 * Free a fragment reassembly header and all
 * associated datagrams.
 */
static void
ip_freef(Slirp *slirp, struct ipq *fp)
{
	register struct ipasfrag *q, *p;

	for (q = fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link; q = p) {
		p = q->ipf_next;
		ip_deq(q);
		m_freem(dtom(slirp, q));
	}
	remque(&fp->ip_link);
	(void) m_free(dtom(slirp, fp));
}

/*
 * Put an ip fragment on a reassembly chain.
 * Like insque, but pointers in middle of structure.
 */
static void
ip_enq(register struct ipasfrag *p, register struct ipasfrag *prev)
{
	DEBUG_CALL("ip_enq");
	DEBUG_ARG("prev = %lx", (long)prev);
	p->ipf_prev =  prev;
	p->ipf_next = prev->ipf_next;
	((struct ipasfrag *)(prev->ipf_next))->ipf_prev = p;
	prev->ipf_next = p;
}

/*
 * To ip_enq as remque is to insque.
 */
static void
ip_deq(register struct ipasfrag *p)
{
	((struct ipasfrag *)(p->ipf_prev))->ipf_next = p->ipf_next;
	((struct ipasfrag *)(p->ipf_next))->ipf_prev = p->ipf_prev;
}

/*
 * IP timer processing;
 * if a timer expires on a reassembly
 * queue, discard it.
 */
void
ip_slowtimo(Slirp *slirp)
{
    struct qlink *l;

	DEBUG_CALL("ip_slowtimo");

    l = slirp->ipq.ip_link.next;

        if (l == NULL)
	   return;

    while (l != &slirp->ipq.ip_link) {
        struct ipq *fp = container_of(l, struct ipq, ip_link);
        l = l->next;
		if (--fp->ipq_ttl == 0) {
			ip_freef(slirp, fp);
		}
    }
}

/*
 * Do option processing on a datagram,
 * possibly discarding it if bad options are encountered,
 * or forwarding it if source-routed.
 * Returns 1 if packet has been forwarded/freed,
 * 0 if the packet should be processed further.
 */

#ifdef notdef

int
ip_dooptions(m)
	struct mbuf *m;
{
	register struct ip *ip = mtod(m, struct ip *);
	register u_char *cp;
	register struct ip_timestamp *ipt;
	register struct in_ifaddr *ia;
	int opt, optlen, cnt, off, code, type, forward = 0;
	struct in_addr *sin, dst;
typedef u_int32_t n_time;
	n_time ntime;

	dst = ip->ip_dst;
	cp = (u_char *)(ip + 1);
	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
	for (; cnt > 0; cnt -= optlen, cp += optlen) {
		opt = cp[IPOPT_OPTVAL];
		if (opt == IPOPT_EOL)
			break;
		if (opt == IPOPT_NOP)
			optlen = 1;
		else {
			optlen = cp[IPOPT_OLEN];
			if (optlen <= 0 || optlen > cnt) {
				code = &cp[IPOPT_OLEN] - (u_char *)ip;
				goto bad;
			}
		}
		switch (opt) {

		default:
			break;

		/*
		 * Source routing with record.
		 * Find interface with current destination address.
		 * If none on this machine then drop if strictly routed,
		 * or do nothing if loosely routed.
		 * Record interface address and bring up next address
		 * component.  If strictly routed make sure next
		 * address is on directly accessible net.
		 */
		case IPOPT_LSRR:
		case IPOPT_SSRR:
			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
				goto bad;
			}
			ipaddr.sin_addr = ip->ip_dst;
			ia = (struct in_ifaddr *)
				ifa_ifwithaddr((struct sockaddr *)&ipaddr);
			if (ia == 0) {
				if (opt == IPOPT_SSRR) {
					type = ICMP_UNREACH;
					code = ICMP_UNREACH_SRCFAIL;
					goto bad;
				}
				/*
				 * Loose routing, and not at next destination
				 * yet; nothing to do except forward.
				 */
				break;
			}
			off--;			/ * 0 origin *  /
			if (off > optlen - sizeof(struct in_addr)) {
				/*
				 * End of source route.  Should be for us.
				 */
				save_rte(cp, ip->ip_src);
				break;
			}
			/*
			 * locate outgoing interface
			 */
			bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
			    sizeof(ipaddr.sin_addr));
			if (opt == IPOPT_SSRR) {
#define	INA	struct in_ifaddr *
#define	SA	struct sockaddr *
 			    if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
				ia = (INA)ifa_ifwithnet((SA)&ipaddr);
			} else
				ia = ip_rtaddr(ipaddr.sin_addr);
			if (ia == 0) {
				type = ICMP_UNREACH;
				code = ICMP_UNREACH_SRCFAIL;
				goto bad;
			}
			ip->ip_dst = ipaddr.sin_addr;
			bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
			    (caddr_t)(cp + off), sizeof(struct in_addr));
			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
			/*
			 * Let ip_intr's mcast routing check handle mcast pkts
			 */
			forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
			break;

		case IPOPT_RR:
			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
				goto bad;
			}
			/*
			 * If no space remains, ignore.
			 */
			off--;			 * 0 origin *
			if (off > optlen - sizeof(struct in_addr))
				break;
			bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
			    sizeof(ipaddr.sin_addr));
			/*
			 * locate outgoing interface; if we're the destination,
			 * use the incoming interface (should be same).
			 */
			if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
			    (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
				type = ICMP_UNREACH;
				code = ICMP_UNREACH_HOST;
				goto bad;
			}
			bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
			    (caddr_t)(cp + off), sizeof(struct in_addr));
			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
			break;

		case IPOPT_TS:
			code = cp - (u_char *)ip;
			ipt = (struct ip_timestamp *)cp;
			if (ipt->ipt_len < 5)
				goto bad;
			if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
				if (++ipt->ipt_oflw == 0)
					goto bad;
				break;
			}
			sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
			switch (ipt->ipt_flg) {

			case IPOPT_TS_TSONLY:
				break;

			case IPOPT_TS_TSANDADDR:
				if (ipt->ipt_ptr + sizeof(n_time) +
				    sizeof(struct in_addr) > ipt->ipt_len)
					goto bad;
				ipaddr.sin_addr = dst;
				ia = (INA)ifaof_ i f p foraddr((SA)&ipaddr,
							    m->m_pkthdr.rcvif);
				if (ia == 0)
					continue;
				bcopy((caddr_t)&IA_SIN(ia)->sin_addr,
				    (caddr_t)sin, sizeof(struct in_addr));
				ipt->ipt_ptr += sizeof(struct in_addr);
				break;

			case IPOPT_TS_PRESPEC:
				if (ipt->ipt_ptr + sizeof(n_time) +
				    sizeof(struct in_addr) > ipt->ipt_len)
					goto bad;
				bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
				    sizeof(struct in_addr));
				if (ifa_ifwithaddr((SA)&ipaddr) == 0)
					continue;
				ipt->ipt_ptr += sizeof(struct in_addr);
				break;

			default:
				goto bad;
			}
			ntime = iptime();
			bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
			    sizeof(n_time));
			ipt->ipt_ptr += sizeof(n_time);
		}
	}
	if (forward) {
		ip_forward(m, 1);
		return (1);
	}
	return (0);
bad:
 	icmp_error(m, type, code, 0, 0);

	return (1);
}

#endif /* notdef */

/*
 * Strip out IP options, at higher
 * level protocol in the kernel.
 * Second argument is buffer to which options
 * will be moved, and return value is their length.
 * (XXX) should be deleted; last arg currently ignored.
 */
void
ip_stripoptions(register struct mbuf *m, struct mbuf *mopt)
{
	register int i;
	struct ip *ip = mtod(m, struct ip *);
	register caddr_t opts;
	int olen;

	olen = (ip->ip_hl<<2) - sizeof (struct ip);
	opts = (caddr_t)(ip + 1);
	i = m->m_len - (sizeof (struct ip) + olen);
	memcpy(opts, opts  + olen, (unsigned)i);
	m->m_len -= olen;

	ip->ip_hl = sizeof(struct ip) >> 2;
}