Register keyword removal
[dragonfly.git] / sys / netinet / ip_icmp.c
CommitLineData
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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_icmp.c 8.2 (Berkeley) 1/4/94
34 * $FreeBSD: src/sys/netinet/ip_icmp.c,v 1.39.2.19 2003/01/24 05:11:34 sam Exp $
2256ba69 35 * $DragonFly: src/sys/netinet/ip_icmp.c,v 1.3 2003/07/26 21:00:04 rob Exp $
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36 */
37
38#include "opt_ipsec.h"
39
40#include <sys/param.h>
41#include <sys/systm.h>
42#include <sys/mbuf.h>
43#include <sys/protosw.h>
44#include <sys/socket.h>
45#include <sys/time.h>
46#include <sys/kernel.h>
47#include <sys/sysctl.h>
48
49#include <net/if.h>
50#include <net/if_types.h>
51#include <net/route.h>
52
53#define _IP_VHL
54#include <netinet/in.h>
55#include <netinet/in_systm.h>
56#include <netinet/in_var.h>
57#include <netinet/ip.h>
58#include <netinet/ip_icmp.h>
59#include <netinet/ip_var.h>
60#include <netinet/icmp_var.h>
61
62#ifdef IPSEC
63#include <netinet6/ipsec.h>
64#include <netkey/key.h>
65#endif
66
67#ifdef FAST_IPSEC
68#include <netipsec/ipsec.h>
69#include <netipsec/key.h>
70#define IPSEC
71#endif
72
73/*
74 * ICMP routines: error generation, receive packet processing, and
75 * routines to turnaround packets back to the originator, and
76 * host table maintenance routines.
77 */
78
79static struct icmpstat icmpstat;
80SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats, CTLFLAG_RW,
81 &icmpstat, icmpstat, "");
82
83static int icmpmaskrepl = 0;
84SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW,
85 &icmpmaskrepl, 0, "");
86
87static int drop_redirect = 0;
88SYSCTL_INT(_net_inet_icmp, OID_AUTO, drop_redirect, CTLFLAG_RW,
89 &drop_redirect, 0, "");
90
91static int log_redirect = 0;
92SYSCTL_INT(_net_inet_icmp, OID_AUTO, log_redirect, CTLFLAG_RW,
93 &log_redirect, 0, "");
94
95#ifdef ICMP_BANDLIM
96
97/*
98 * ICMP error-response bandwidth limiting sysctl. If not enabled, sysctl
99 * variable content is -1 and read-only.
100 */
101
102static int icmplim = 200;
103SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RW,
104 &icmplim, 0, "");
105#else
106
107static int icmplim = -1;
108SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RD,
109 &icmplim, 0, "");
110
111#endif
112
113static int icmplim_output = 1;
114SYSCTL_INT(_net_inet_icmp, OID_AUTO, icmplim_output, CTLFLAG_RW,
115 &icmplim_output, 0, "");
116
117/*
118 * ICMP broadcast echo sysctl
119 */
120
121static int icmpbmcastecho = 0;
122SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_RW,
123 &icmpbmcastecho, 0, "");
124
125
126#ifdef ICMPPRINTFS
127int icmpprintfs = 0;
128#endif
129
130static void icmp_reflect __P((struct mbuf *));
131static void icmp_send __P((struct mbuf *, struct mbuf *, struct route *));
132static int ip_next_mtu __P((int, int));
133
134extern struct protosw inetsw[];
135
136/*
137 * Generate an error packet of type error
138 * in response to bad packet ip.
139 */
140void
141icmp_error(n, type, code, dest, destifp)
142 struct mbuf *n;
143 int type, code;
144 n_long dest;
145 struct ifnet *destifp;
146{
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147 struct ip *oip = mtod(n, struct ip *), *nip;
148 unsigned oiplen = IP_VHL_HL(oip->ip_vhl) << 2;
149 struct icmp *icp;
150 struct mbuf *m;
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151 unsigned icmplen;
152
153#ifdef ICMPPRINTFS
154 if (icmpprintfs)
155 printf("icmp_error(%p, %x, %d)\n", oip, type, code);
156#endif
157 if (type != ICMP_REDIRECT)
158 icmpstat.icps_error++;
159 /*
160 * Don't send error if not the first fragment of message.
161 * Don't error if the old packet protocol was ICMP
162 * error message, only known informational types.
163 */
164 if (oip->ip_off &~ (IP_MF|IP_DF))
165 goto freeit;
166 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
167 n->m_len >= oiplen + ICMP_MINLEN &&
168 !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) {
169 icmpstat.icps_oldicmp++;
170 goto freeit;
171 }
172 /* Don't send error in response to a multicast or broadcast packet */
173 if (n->m_flags & (M_BCAST|M_MCAST))
174 goto freeit;
175 /*
176 * First, formulate icmp message
177 */
178 m = m_gethdr(M_DONTWAIT, MT_HEADER);
179 if (m == NULL)
180 goto freeit;
181 icmplen = min(oiplen + 8, oip->ip_len);
182 if (icmplen < sizeof(struct ip))
183 panic("icmp_error: bad length");
184 m->m_len = icmplen + ICMP_MINLEN;
185 MH_ALIGN(m, m->m_len);
186 icp = mtod(m, struct icmp *);
187 if ((u_int)type > ICMP_MAXTYPE)
188 panic("icmp_error");
189 icmpstat.icps_outhist[type]++;
190 icp->icmp_type = type;
191 if (type == ICMP_REDIRECT)
192 icp->icmp_gwaddr.s_addr = dest;
193 else {
194 icp->icmp_void = 0;
195 /*
196 * The following assignments assume an overlay with the
197 * zeroed icmp_void field.
198 */
199 if (type == ICMP_PARAMPROB) {
200 icp->icmp_pptr = code;
201 code = 0;
202 } else if (type == ICMP_UNREACH &&
203 code == ICMP_UNREACH_NEEDFRAG && destifp) {
204 icp->icmp_nextmtu = htons(destifp->if_mtu);
205 }
206 }
207
208 icp->icmp_code = code;
209 m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip);
210 nip = &icp->icmp_ip;
211
212 /*
213 * Convert fields to network representation.
214 */
215 HTONS(nip->ip_len);
216 HTONS(nip->ip_off);
217
218 /*
219 * Now, copy old ip header (without options)
220 * in front of icmp message.
221 */
222 if (m->m_data - sizeof(struct ip) < m->m_pktdat)
223 panic("icmp len");
224 m->m_data -= sizeof(struct ip);
225 m->m_len += sizeof(struct ip);
226 m->m_pkthdr.len = m->m_len;
227 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
228 nip = mtod(m, struct ip *);
229 bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip));
230 nip->ip_len = m->m_len;
231 nip->ip_vhl = IP_VHL_BORING;
232 nip->ip_p = IPPROTO_ICMP;
233 nip->ip_tos = 0;
234 icmp_reflect(m);
235
236freeit:
237 m_freem(n);
238}
239
240static struct sockaddr_in icmpsrc = { sizeof (struct sockaddr_in), AF_INET };
241static struct sockaddr_in icmpdst = { sizeof (struct sockaddr_in), AF_INET };
242static struct sockaddr_in icmpgw = { sizeof (struct sockaddr_in), AF_INET };
243
244/*
245 * Process a received ICMP message.
246 */
247void
248icmp_input(m, off, proto)
2256ba69 249 struct mbuf *m;
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250 int off, proto;
251{
252 int hlen = off;
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253 struct icmp *icp;
254 struct ip *ip = mtod(m, struct ip *);
984263bc 255 int icmplen = ip->ip_len;
2256ba69 256 int i;
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257 struct in_ifaddr *ia;
258 void (*ctlfunc) __P((int, struct sockaddr *, void *));
259 int code;
260
261 /*
262 * Locate icmp structure in mbuf, and check
263 * that not corrupted and of at least minimum length.
264 */
265#ifdef ICMPPRINTFS
266 if (icmpprintfs) {
267 char buf[4 * sizeof "123"];
268 strcpy(buf, inet_ntoa(ip->ip_src));
269 printf("icmp_input from %s to %s, len %d\n",
270 buf, inet_ntoa(ip->ip_dst), icmplen);
271 }
272#endif
273 if (icmplen < ICMP_MINLEN) {
274 icmpstat.icps_tooshort++;
275 goto freeit;
276 }
277 i = hlen + min(icmplen, ICMP_ADVLENMIN);
278 if (m->m_len < i && (m = m_pullup(m, i)) == 0) {
279 icmpstat.icps_tooshort++;
280 return;
281 }
282 ip = mtod(m, struct ip *);
283 m->m_len -= hlen;
284 m->m_data += hlen;
285 icp = mtod(m, struct icmp *);
286 if (in_cksum(m, icmplen)) {
287 icmpstat.icps_checksum++;
288 goto freeit;
289 }
290 m->m_len += hlen;
291 m->m_data -= hlen;
292
293 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
294 /*
295 * Deliver very specific ICMP type only.
296 */
297 switch (icp->icmp_type) {
298 case ICMP_UNREACH:
299 case ICMP_TIMXCEED:
300 break;
301 default:
302 goto freeit;
303 }
304 }
305
306#ifdef ICMPPRINTFS
307 if (icmpprintfs)
308 printf("icmp_input, type %d code %d\n", icp->icmp_type,
309 icp->icmp_code);
310#endif
311
312 /*
313 * Message type specific processing.
314 */
315 if (icp->icmp_type > ICMP_MAXTYPE)
316 goto raw;
317 icmpstat.icps_inhist[icp->icmp_type]++;
318 code = icp->icmp_code;
319 switch (icp->icmp_type) {
320
321 case ICMP_UNREACH:
322 switch (code) {
323 case ICMP_UNREACH_NET:
324 case ICMP_UNREACH_HOST:
325 case ICMP_UNREACH_SRCFAIL:
326 case ICMP_UNREACH_NET_UNKNOWN:
327 case ICMP_UNREACH_HOST_UNKNOWN:
328 case ICMP_UNREACH_ISOLATED:
329 case ICMP_UNREACH_TOSNET:
330 case ICMP_UNREACH_TOSHOST:
331 case ICMP_UNREACH_HOST_PRECEDENCE:
332 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
333 code = PRC_UNREACH_NET;
334 break;
335
336 case ICMP_UNREACH_NEEDFRAG:
337 code = PRC_MSGSIZE;
338 break;
339
340 /*
341 * RFC 1122, Sections 3.2.2.1 and 4.2.3.9.
342 * Treat subcodes 2,3 as immediate RST
343 */
344 case ICMP_UNREACH_PROTOCOL:
345 case ICMP_UNREACH_PORT:
346 code = PRC_UNREACH_PORT;
347 break;
348
349 case ICMP_UNREACH_NET_PROHIB:
350 case ICMP_UNREACH_HOST_PROHIB:
351 case ICMP_UNREACH_FILTER_PROHIB:
352 code = PRC_UNREACH_ADMIN_PROHIB;
353 break;
354
355 default:
356 goto badcode;
357 }
358 goto deliver;
359
360 case ICMP_TIMXCEED:
361 if (code > 1)
362 goto badcode;
363 code += PRC_TIMXCEED_INTRANS;
364 goto deliver;
365
366 case ICMP_PARAMPROB:
367 if (code > 1)
368 goto badcode;
369 code = PRC_PARAMPROB;
370 goto deliver;
371
372 case ICMP_SOURCEQUENCH:
373 if (code)
374 goto badcode;
375 code = PRC_QUENCH;
376 deliver:
377 /*
378 * Problem with datagram; advise higher level routines.
379 */
380 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
381 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
382 icmpstat.icps_badlen++;
383 goto freeit;
384 }
385 NTOHS(icp->icmp_ip.ip_len);
386 /* Discard ICMP's in response to multicast packets */
387 if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr)))
388 goto badcode;
389#ifdef ICMPPRINTFS
390 if (icmpprintfs)
391 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
392#endif
393 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
394#if 1
395 /*
396 * MTU discovery:
397 * If we got a needfrag and there is a host route to the
398 * original destination, and the MTU is not locked, then
399 * set the MTU in the route to the suggested new value
400 * (if given) and then notify as usual. The ULPs will
401 * notice that the MTU has changed and adapt accordingly.
402 * If no new MTU was suggested, then we guess a new one
403 * less than the current value. If the new MTU is
404 * unreasonably small (arbitrarily set at 296), then
405 * we reset the MTU to the interface value and enable the
406 * lock bit, indicating that we are no longer doing MTU
407 * discovery.
408 */
409 if (code == PRC_MSGSIZE) {
410 struct rtentry *rt;
411 int mtu;
412
413 rt = rtalloc1((struct sockaddr *)&icmpsrc, 0,
414 RTF_CLONING | RTF_PRCLONING);
415 if (rt && (rt->rt_flags & RTF_HOST)
416 && !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
417 mtu = ntohs(icp->icmp_nextmtu);
418 if (!mtu)
419 mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu,
420 1);
421#ifdef DEBUG_MTUDISC
422 printf("MTU for %s reduced to %d\n",
423 inet_ntoa(icmpsrc.sin_addr), mtu);
424#endif
425 if (mtu < 296) {
426 /* rt->rt_rmx.rmx_mtu =
427 rt->rt_ifp->if_mtu; */
428 rt->rt_rmx.rmx_locks |= RTV_MTU;
429 } else if (rt->rt_rmx.rmx_mtu > mtu) {
430 rt->rt_rmx.rmx_mtu = mtu;
431 }
432 }
433 if (rt)
434 RTFREE(rt);
435 }
436
437#endif
438 /*
439 * XXX if the packet contains [IPv4 AH TCP], we can't make a
440 * notification to TCP layer.
441 */
442 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput;
443 if (ctlfunc)
444 (*ctlfunc)(code, (struct sockaddr *)&icmpsrc,
445 (void *)&icp->icmp_ip);
446 break;
447
448 badcode:
449 icmpstat.icps_badcode++;
450 break;
451
452 case ICMP_ECHO:
453 if (!icmpbmcastecho
454 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
455 icmpstat.icps_bmcastecho++;
456 break;
457 }
458 icp->icmp_type = ICMP_ECHOREPLY;
459#ifdef ICMP_BANDLIM
460 if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0)
461 goto freeit;
462 else
463#endif
464 goto reflect;
465
466 case ICMP_TSTAMP:
467 if (!icmpbmcastecho
468 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
469 icmpstat.icps_bmcasttstamp++;
470 break;
471 }
472 if (icmplen < ICMP_TSLEN) {
473 icmpstat.icps_badlen++;
474 break;
475 }
476 icp->icmp_type = ICMP_TSTAMPREPLY;
477 icp->icmp_rtime = iptime();
478 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
479#ifdef ICMP_BANDLIM
480 if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0)
481 goto freeit;
482 else
483#endif
484 goto reflect;
485
486 case ICMP_MASKREQ:
487 if (icmpmaskrepl == 0)
488 break;
489 /*
490 * We are not able to respond with all ones broadcast
491 * unless we receive it over a point-to-point interface.
492 */
493 if (icmplen < ICMP_MASKLEN)
494 break;
495 switch (ip->ip_dst.s_addr) {
496
497 case INADDR_BROADCAST:
498 case INADDR_ANY:
499 icmpdst.sin_addr = ip->ip_src;
500 break;
501
502 default:
503 icmpdst.sin_addr = ip->ip_dst;
504 }
505 ia = (struct in_ifaddr *)ifaof_ifpforaddr(
506 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
507 if (ia == 0)
508 break;
509 if (ia->ia_ifp == 0)
510 break;
511 icp->icmp_type = ICMP_MASKREPLY;
512 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
513 if (ip->ip_src.s_addr == 0) {
514 if (ia->ia_ifp->if_flags & IFF_BROADCAST)
515 ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr;
516 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
517 ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr;
518 }
519reflect:
520 ip->ip_len += hlen; /* since ip_input deducts this */
521 icmpstat.icps_reflect++;
522 icmpstat.icps_outhist[icp->icmp_type]++;
523 icmp_reflect(m);
524 return;
525
526 case ICMP_REDIRECT:
527 if (log_redirect) {
528 u_long src, dst, gw;
529
530 src = ntohl(ip->ip_src.s_addr);
531 dst = ntohl(icp->icmp_ip.ip_dst.s_addr);
532 gw = ntohl(icp->icmp_gwaddr.s_addr);
533 printf("icmp redirect from %d.%d.%d.%d: "
534 "%d.%d.%d.%d => %d.%d.%d.%d\n",
535 (int)(src >> 24), (int)((src >> 16) & 0xff),
536 (int)((src >> 8) & 0xff), (int)(src & 0xff),
537 (int)(dst >> 24), (int)((dst >> 16) & 0xff),
538 (int)((dst >> 8) & 0xff), (int)(dst & 0xff),
539 (int)(gw >> 24), (int)((gw >> 16) & 0xff),
540 (int)((gw >> 8) & 0xff), (int)(gw & 0xff));
541 }
542 if (drop_redirect)
543 break;
544 if (code > 3)
545 goto badcode;
546 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
547 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
548 icmpstat.icps_badlen++;
549 break;
550 }
551 /*
552 * Short circuit routing redirects to force
553 * immediate change in the kernel's routing
554 * tables. The message is also handed to anyone
555 * listening on a raw socket (e.g. the routing
556 * daemon for use in updating its tables).
557 */
558 icmpgw.sin_addr = ip->ip_src;
559 icmpdst.sin_addr = icp->icmp_gwaddr;
560#ifdef ICMPPRINTFS
561 if (icmpprintfs) {
562 char buf[4 * sizeof "123"];
563 strcpy(buf, inet_ntoa(icp->icmp_ip.ip_dst));
564
565 printf("redirect dst %s to %s\n",
566 buf, inet_ntoa(icp->icmp_gwaddr));
567 }
568#endif
569 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
570 rtredirect((struct sockaddr *)&icmpsrc,
571 (struct sockaddr *)&icmpdst,
572 (struct sockaddr *)0, RTF_GATEWAY | RTF_HOST,
573 (struct sockaddr *)&icmpgw, (struct rtentry **)0);
574 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc);
575#ifdef IPSEC
576 key_sa_routechange((struct sockaddr *)&icmpsrc);
577#endif
578 break;
579
580 /*
581 * No kernel processing for the following;
582 * just fall through to send to raw listener.
583 */
584 case ICMP_ECHOREPLY:
585 case ICMP_ROUTERADVERT:
586 case ICMP_ROUTERSOLICIT:
587 case ICMP_TSTAMPREPLY:
588 case ICMP_IREQREPLY:
589 case ICMP_MASKREPLY:
590 default:
591 break;
592 }
593
594raw:
595 rip_input(m, off, proto);
596 return;
597
598freeit:
599 m_freem(m);
600}
601
602/*
603 * Reflect the ip packet back to the source
604 */
605static void
606icmp_reflect(m)
607 struct mbuf *m;
608{
609 struct ip *ip = mtod(m, struct ip *);
610 struct ifaddr *ifa;
611 struct in_ifaddr *ia;
612 struct in_addr t;
613 struct mbuf *opts = 0;
614 int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
615 struct route *ro = NULL, rt;
616
617 if (!in_canforward(ip->ip_src) &&
618 ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
619 (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
620 m_freem(m); /* Bad return address */
621 icmpstat.icps_badaddr++;
622 goto done; /* Ip_output() will check for broadcast */
623 }
624 t = ip->ip_dst;
625 ip->ip_dst = ip->ip_src;
626 ro = &rt;
627 bzero(ro, sizeof(*ro));
628 /*
629 * If the incoming packet was addressed directly to us,
630 * use dst as the src for the reply. Otherwise (broadcast
631 * or anonymous), use the address which corresponds
632 * to the incoming interface.
633 */
634 LIST_FOREACH(ia, INADDR_HASH(t.s_addr), ia_hash)
635 if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr)
636 goto match;
637 if (m->m_pkthdr.rcvif != NULL &&
638 m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
639 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
640 if (ifa->ifa_addr->sa_family != AF_INET)
641 continue;
642 ia = ifatoia(ifa);
643 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
644 t.s_addr)
645 goto match;
646 }
647 }
648 ia = ip_rtaddr(ip->ip_dst, ro);
649 /* We need a route to do anything useful. */
650 if (ia == NULL) {
651 m_freem(m);
652 icmpstat.icps_noroute++;
653 goto done;
654 }
655match:
656 t = IA_SIN(ia)->sin_addr;
657 ip->ip_src = t;
658 ip->ip_ttl = ip_defttl;
659
660 if (optlen > 0) {
2256ba69 661 u_char *cp;
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662 int opt, cnt;
663 u_int len;
664
665 /*
666 * Retrieve any source routing from the incoming packet;
667 * add on any record-route or timestamp options.
668 */
669 cp = (u_char *) (ip + 1);
670 if ((opts = ip_srcroute()) == 0 &&
671 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) {
672 opts->m_len = sizeof(struct in_addr);
673 mtod(opts, struct in_addr *)->s_addr = 0;
674 }
675 if (opts) {
676#ifdef ICMPPRINTFS
677 if (icmpprintfs)
678 printf("icmp_reflect optlen %d rt %d => ",
679 optlen, opts->m_len);
680#endif
681 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
682 opt = cp[IPOPT_OPTVAL];
683 if (opt == IPOPT_EOL)
684 break;
685 if (opt == IPOPT_NOP)
686 len = 1;
687 else {
688 if (cnt < IPOPT_OLEN + sizeof(*cp))
689 break;
690 len = cp[IPOPT_OLEN];
691 if (len < IPOPT_OLEN + sizeof(*cp) ||
692 len > cnt)
693 break;
694 }
695 /*
696 * Should check for overflow, but it "can't happen"
697 */
698 if (opt == IPOPT_RR || opt == IPOPT_TS ||
699 opt == IPOPT_SECURITY) {
700 bcopy((caddr_t)cp,
701 mtod(opts, caddr_t) + opts->m_len, len);
702 opts->m_len += len;
703 }
704 }
705 /* Terminate & pad, if necessary */
706 cnt = opts->m_len % 4;
707 if (cnt) {
708 for (; cnt < 4; cnt++) {
709 *(mtod(opts, caddr_t) + opts->m_len) =
710 IPOPT_EOL;
711 opts->m_len++;
712 }
713 }
714#ifdef ICMPPRINTFS
715 if (icmpprintfs)
716 printf("%d\n", opts->m_len);
717#endif
718 }
719 /*
720 * Now strip out original options by copying rest of first
721 * mbuf's data back, and adjust the IP length.
722 */
723 ip->ip_len -= optlen;
724 ip->ip_vhl = IP_VHL_BORING;
725 m->m_len -= optlen;
726 if (m->m_flags & M_PKTHDR)
727 m->m_pkthdr.len -= optlen;
728 optlen += sizeof(struct ip);
729 bcopy((caddr_t)ip + optlen, (caddr_t)(ip + 1),
730 (unsigned)(m->m_len - sizeof(struct ip)));
731 }
732 m->m_flags &= ~(M_BCAST|M_MCAST);
733 icmp_send(m, opts, ro);
734done:
735 if (opts)
736 (void)m_free(opts);
737 if (ro && ro->ro_rt)
738 RTFREE(ro->ro_rt);
739}
740
741/*
742 * Send an icmp packet back to the ip level,
743 * after supplying a checksum.
744 */
745static void
746icmp_send(m, opts, rt)
2256ba69 747 struct mbuf *m;
984263bc
MD
748 struct mbuf *opts;
749 struct route *rt;
750{
2256ba69
RG
751 struct ip *ip = mtod(m, struct ip *);
752 int hlen;
753 struct icmp *icp;
984263bc
MD
754
755 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
756 m->m_data += hlen;
757 m->m_len -= hlen;
758 icp = mtod(m, struct icmp *);
759 icp->icmp_cksum = 0;
760 icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
761 m->m_data -= hlen;
762 m->m_len += hlen;
763 m->m_pkthdr.rcvif = (struct ifnet *)0;
764#ifdef ICMPPRINTFS
765 if (icmpprintfs) {
766 char buf[4 * sizeof "123"];
767 strcpy(buf, inet_ntoa(ip->ip_dst));
768 printf("icmp_send dst %s src %s\n",
769 buf, inet_ntoa(ip->ip_src));
770 }
771#endif
772 (void) ip_output(m, opts, rt, 0, NULL, NULL);
773}
774
775n_time
776iptime()
777{
778 struct timeval atv;
779 u_long t;
780
781 getmicrotime(&atv);
782 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
783 return (htonl(t));
784}
785
786#if 1
787/*
788 * Return the next larger or smaller MTU plateau (table from RFC 1191)
789 * given current value MTU. If DIR is less than zero, a larger plateau
790 * is returned; otherwise, a smaller value is returned.
791 */
792static int
793ip_next_mtu(mtu, dir)
794 int mtu;
795 int dir;
796{
797 static int mtutab[] = {
798 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296,
799 68, 0
800 };
801 int i;
802
803 for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
804 if (mtu >= mtutab[i])
805 break;
806 }
807
808 if (dir < 0) {
809 if (i == 0) {
810 return 0;
811 } else {
812 return mtutab[i - 1];
813 }
814 } else {
815 if (mtutab[i] == 0) {
816 return 0;
817 } else if(mtu > mtutab[i]) {
818 return mtutab[i];
819 } else {
820 return mtutab[i + 1];
821 }
822 }
823}
824#endif
825
826#ifdef ICMP_BANDLIM
827
828/*
829 * badport_bandlim() - check for ICMP bandwidth limit
830 *
831 * Return 0 if it is ok to send an ICMP error response, -1 if we have
832 * hit our bandwidth limit and it is not ok.
833 *
834 * If icmplim is <= 0, the feature is disabled and 0 is returned.
835 *
836 * For now we separate the TCP and UDP subsystems w/ different 'which'
837 * values. We may eventually remove this separation (and simplify the
838 * code further).
839 *
840 * Note that the printing of the error message is delayed so we can
841 * properly print the icmp error rate that the system was trying to do
842 * (i.e. 22000/100 pps, etc...). This can cause long delays in printing
843 * the 'final' error, but it doesn't make sense to solve the printing
844 * delay with more complex code.
845 */
846
847int
848badport_bandlim(int which)
849{
850 static int lticks[BANDLIM_MAX + 1];
851 static int lpackets[BANDLIM_MAX + 1];
852 int dticks;
853 const char *bandlimittype[] = {
854 "Limiting icmp unreach response",
855 "Limiting icmp ping response",
856 "Limiting icmp tstamp response",
857 "Limiting closed port RST response",
858 "Limiting open port RST response"
859 };
860
861 /*
862 * Return ok status if feature disabled or argument out of
863 * ranage.
864 */
865
866 if (icmplim <= 0 || which > BANDLIM_MAX || which < 0)
867 return(0);
868 dticks = ticks - lticks[which];
869
870 /*
871 * reset stats when cumulative dt exceeds one second.
872 */
873
874 if ((unsigned int)dticks > hz) {
875 if (lpackets[which] > icmplim && icmplim_output) {
876 printf("%s from %d to %d packets per second\n",
877 bandlimittype[which],
878 lpackets[which],
879 icmplim
880 );
881 }
882 lticks[which] = ticks;
883 lpackets[which] = 0;
884 }
885
886 /*
887 * bump packet count
888 */
889
890 if (++lpackets[which] > icmplim) {
891 return(-1);
892 }
893 return(0);
894}
895
896#endif
897
898