build: Add ICMPPRINTFS as global option
[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.
dc71b7ab 13 * 3. Neither the name of the University nor the names of its contributors
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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_icmp.c 8.2 (Berkeley) 1/4/94
30 * $FreeBSD: src/sys/netinet/ip_icmp.c,v 1.39.2.19 2003/01/24 05:11:34 sam Exp $
31 */
32
33#include "opt_ipsec.h"
34
35#include <sys/param.h>
36#include <sys/systm.h>
37#include <sys/mbuf.h>
38#include <sys/protosw.h>
39#include <sys/socket.h>
e3873585 40#include <sys/socketops.h>
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41#include <sys/time.h>
42#include <sys/kernel.h>
43#include <sys/sysctl.h>
3f9db7f8 44#include <sys/in_cksum.h>
984263bc 45
a00138cb
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46#include <machine/stdarg.h>
47
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48#include <net/if.h>
49#include <net/if_types.h>
50#include <net/route.h>
51
52#define _IP_VHL
53#include <netinet/in.h>
54#include <netinet/in_systm.h>
55#include <netinet/in_var.h>
56#include <netinet/ip.h>
57#include <netinet/ip_icmp.h>
58#include <netinet/ip_var.h>
59#include <netinet/icmp_var.h>
60
61#ifdef IPSEC
62#include <netinet6/ipsec.h>
d2438d69 63#include <netproto/key/key.h>
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64#endif
65
66#ifdef FAST_IPSEC
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67#include <netproto/ipsec/ipsec.h>
68#include <netproto/ipsec/key.h>
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69#define IPSEC
70#endif
71
72/*
73 * ICMP routines: error generation, receive packet processing, and
74 * routines to turnaround packets back to the originator, and
75 * host table maintenance routines.
76 */
77
02742ec6 78struct icmpstat icmpstat;
984263bc 79SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats, CTLFLAG_RW,
c9458756 80 &icmpstat, icmpstat, "ICMP statistics");
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81
82static int icmpmaskrepl = 0;
83SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW,
c9458756 84 &icmpmaskrepl, 0, "Allow replies to netmask requests");
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85
86static int drop_redirect = 0;
f23061d4 87SYSCTL_INT(_net_inet_icmp, OID_AUTO, drop_redirect, CTLFLAG_RW,
c9458756 88 &drop_redirect, 0, "Ignore ICMP redirects");
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89
90static int log_redirect = 0;
f23061d4 91SYSCTL_INT(_net_inet_icmp, OID_AUTO, log_redirect, CTLFLAG_RW,
c9458756 92 &log_redirect, 0, "Enable output about ICMP redirects");
984263bc 93
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94static int discard_sourcequench = 1;
95SYSCTL_INT(_net_inet_icmp, OID_AUTO, discard_sourcequench, CTLFLAG_RW,
96 &discard_sourcequench, 0, "Discard ICMP Source Quench");
97
f23061d4
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98#ifdef ICMP_BANDLIM
99
100/*
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101 * ICMP error-response bandwidth limiting sysctl. If not enabled, sysctl
102 * variable content is -1 and read-only.
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103 */
104
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105static int icmplim = 200;
106SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RW,
c9458756 107 &icmplim, 0, "ICMP bandwidth limit");
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108#else
109
110static int icmplim = -1;
111SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RD,
c9458756 112 &icmplim, 0, "ICMP bandwidth limit");
984263bc 113
f23061d4 114#endif
984263bc 115
668c3d22 116static int icmplim_output = 0;
984263bc 117SYSCTL_INT(_net_inet_icmp, OID_AUTO, icmplim_output, CTLFLAG_RW,
c9458756 118 &icmplim_output, 0, "Enable output about ICMP bandwidth limits");
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119
120/*
121 * ICMP broadcast echo sysctl
122 */
123
124static int icmpbmcastecho = 0;
125SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_RW,
c9458756 126 &icmpbmcastecho, 0, "");
984263bc 127
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128static char icmp_reply_src[IFNAMSIZ];
129SYSCTL_STRING(_net_inet_icmp, OID_AUTO, reply_src, CTLFLAG_RW,
130 icmp_reply_src, IFNAMSIZ, "icmp reply source for non-local packets.");
131
132static int icmp_rfi;
133SYSCTL_INT(_net_inet_icmp, OID_AUTO, reply_from_interface, CTLFLAG_RW,
134 &icmp_rfi, 0, "ICMP reply from incoming interface for "
135 "non-local packets");
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136
137#ifdef ICMPPRINTFS
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138static int icmpprintfs = 0;
139SYSCTL_INT(_net_inet_icmp, OID_AUTO, debug_prints, CTLFLAG_RW,
140 &icmpprintfs, 0, "extra ICMP debug prints");
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141#endif
142
42a7fc75
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143static void icmp_reflect (struct mbuf *);
144static void icmp_send (struct mbuf *, struct mbuf *, struct route *);
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145
146extern struct protosw inetsw[];
147
148/*
149 * Generate an error packet of type error
150 * in response to bad packet ip.
151 */
152void
f3f70f0d 153icmp_error(struct mbuf *n, int type, int code, n_long dest, int destmtu)
984263bc 154{
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155 struct ip *oip = mtod(n, struct ip *), *nip;
156 unsigned oiplen = IP_VHL_HL(oip->ip_vhl) << 2;
157 struct icmp *icp;
158 struct mbuf *m;
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159 unsigned icmplen;
160
161#ifdef ICMPPRINTFS
162 if (icmpprintfs)
a6ec04bc 163 kprintf("icmp_error(%p, %d, %d)\n", oip, type, code);
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164#endif
165 if (type != ICMP_REDIRECT)
166 icmpstat.icps_error++;
167 /*
30de9b21 168 * Don't send error if the original packet was encrypted.
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169 * Don't send error if not the first fragment of message.
170 * Don't error if the old packet protocol was ICMP
171 * error message, only known informational types.
172 */
30de9b21
DR
173 if (n->m_flags & M_DECRYPTED)
174 goto freeit;
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175 if (oip->ip_off &~ (IP_MF|IP_DF))
176 goto freeit;
177 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
178 n->m_len >= oiplen + ICMP_MINLEN &&
179 !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) {
180 icmpstat.icps_oldicmp++;
181 goto freeit;
182 }
183 /* Don't send error in response to a multicast or broadcast packet */
184 if (n->m_flags & (M_BCAST|M_MCAST))
185 goto freeit;
186 /*
187 * First, formulate icmp message
188 */
74f1caca 189 m = m_gethdr(MB_DONTWAIT, MT_HEADER);
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190 if (m == NULL)
191 goto freeit;
192 icmplen = min(oiplen + 8, oip->ip_len);
193 if (icmplen < sizeof(struct ip))
194 panic("icmp_error: bad length");
195 m->m_len = icmplen + ICMP_MINLEN;
196 MH_ALIGN(m, m->m_len);
197 icp = mtod(m, struct icmp *);
198 if ((u_int)type > ICMP_MAXTYPE)
199 panic("icmp_error");
200 icmpstat.icps_outhist[type]++;
201 icp->icmp_type = type;
202 if (type == ICMP_REDIRECT)
203 icp->icmp_gwaddr.s_addr = dest;
204 else {
205 icp->icmp_void = 0;
206 /*
207 * The following assignments assume an overlay with the
208 * zeroed icmp_void field.
209 */
210 if (type == ICMP_PARAMPROB) {
211 icp->icmp_pptr = code;
212 code = 0;
213 } else if (type == ICMP_UNREACH &&
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214 code == ICMP_UNREACH_NEEDFRAG && destmtu) {
215 icp->icmp_nextmtu = htons(destmtu);
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216 }
217 }
218
219 icp->icmp_code = code;
220 m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip);
221 nip = &icp->icmp_ip;
222
223 /*
224 * Convert fields to network representation.
225 */
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226 nip->ip_len = htons(nip->ip_len);
227 nip->ip_off = htons(nip->ip_off);
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228
229 /*
230 * Now, copy old ip header (without options)
231 * in front of icmp message.
232 */
233 if (m->m_data - sizeof(struct ip) < m->m_pktdat)
234 panic("icmp len");
235 m->m_data -= sizeof(struct ip);
236 m->m_len += sizeof(struct ip);
237 m->m_pkthdr.len = m->m_len;
238 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
239 nip = mtod(m, struct ip *);
407e896e 240 bcopy(oip, nip, sizeof(struct ip));
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241 nip->ip_len = m->m_len;
242 nip->ip_vhl = IP_VHL_BORING;
243 nip->ip_p = IPPROTO_ICMP;
244 nip->ip_tos = 0;
f2c2ec09 245 m->m_pkthdr.fw_flags |= n->m_pkthdr.fw_flags & FW_MBUF_GENERATED;
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246 icmp_reflect(m);
247
248freeit:
249 m_freem(n);
250}
251
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252/*
253 * Process a received ICMP message.
254 */
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255int
256icmp_input(struct mbuf **mp, int *offp, int proto)
984263bc 257{
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258 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET };
259 struct sockaddr_in icmpdst = { sizeof(struct sockaddr_in), AF_INET };
260 struct sockaddr_in icmpgw = { sizeof(struct sockaddr_in), AF_INET };
2256ba69 261 struct icmp *icp;
984263bc 262 struct in_ifaddr *ia;
002c1265 263 struct mbuf *m = *mp;
b7929e5c 264 struct ip *ip = mtod(m, struct ip *);
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265 int icmplen = ip->ip_len;
266 int i, hlen;
002c1265 267 int code;
a00138cb 268
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269 *mp = NULL;
270 hlen = *offp;
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271
272 /*
273 * Locate icmp structure in mbuf, and check
274 * that not corrupted and of at least minimum length.
275 */
276#ifdef ICMPPRINTFS
277 if (icmpprintfs) {
1141eb20
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278 char buf[sizeof "aaa.bbb.ccc.ddd"];
279
984263bc 280 strcpy(buf, inet_ntoa(ip->ip_src));
a6ec04bc 281 kprintf("icmp_input from %s to %s, len %d\n",
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282 buf, inet_ntoa(ip->ip_dst), icmplen);
283 }
284#endif
285 if (icmplen < ICMP_MINLEN) {
286 icmpstat.icps_tooshort++;
287 goto freeit;
288 }
289 i = hlen + min(icmplen, ICMP_ADVLENMIN);
4090d6ff 290 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) {
984263bc 291 icmpstat.icps_tooshort++;
002c1265 292 return(IPPROTO_DONE);
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293 }
294 ip = mtod(m, struct ip *);
efa391c4
SZ
295
296 if (in_cksum_skip(m, hlen + icmplen, hlen)) {
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297 icmpstat.icps_checksum++;
298 goto freeit;
299 }
efa391c4 300 icp = mtod(m, struct icmp *);
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301
302 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
303 /*
304 * Deliver very specific ICMP type only.
305 */
306 switch (icp->icmp_type) {
307 case ICMP_UNREACH:
308 case ICMP_TIMXCEED:
309 break;
310 default:
311 goto freeit;
312 }
313 }
314
315#ifdef ICMPPRINTFS
316 if (icmpprintfs)
a6ec04bc 317 kprintf("icmp_input, type %d code %d\n", icp->icmp_type,
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318 icp->icmp_code);
319#endif
320
321 /*
322 * Message type specific processing.
323 */
324 if (icp->icmp_type > ICMP_MAXTYPE)
325 goto raw;
326 icmpstat.icps_inhist[icp->icmp_type]++;
327 code = icp->icmp_code;
328 switch (icp->icmp_type) {
329
330 case ICMP_UNREACH:
331 switch (code) {
332 case ICMP_UNREACH_NET:
333 case ICMP_UNREACH_HOST:
334 case ICMP_UNREACH_SRCFAIL:
335 case ICMP_UNREACH_NET_UNKNOWN:
336 case ICMP_UNREACH_HOST_UNKNOWN:
337 case ICMP_UNREACH_ISOLATED:
338 case ICMP_UNREACH_TOSNET:
339 case ICMP_UNREACH_TOSHOST:
340 case ICMP_UNREACH_HOST_PRECEDENCE:
341 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
342 code = PRC_UNREACH_NET;
343 break;
344
345 case ICMP_UNREACH_NEEDFRAG:
346 code = PRC_MSGSIZE;
347 break;
348
349 /*
350 * RFC 1122, Sections 3.2.2.1 and 4.2.3.9.
351 * Treat subcodes 2,3 as immediate RST
352 */
353 case ICMP_UNREACH_PROTOCOL:
354 case ICMP_UNREACH_PORT:
355 code = PRC_UNREACH_PORT;
356 break;
357
358 case ICMP_UNREACH_NET_PROHIB:
359 case ICMP_UNREACH_HOST_PROHIB:
360 case ICMP_UNREACH_FILTER_PROHIB:
361 code = PRC_UNREACH_ADMIN_PROHIB;
362 break;
363
364 default:
365 goto badcode;
366 }
367 goto deliver;
368
369 case ICMP_TIMXCEED:
370 if (code > 1)
371 goto badcode;
372 code += PRC_TIMXCEED_INTRANS;
373 goto deliver;
374
375 case ICMP_PARAMPROB:
376 if (code > 1)
377 goto badcode;
378 code = PRC_PARAMPROB;
379 goto deliver;
380
381 case ICMP_SOURCEQUENCH:
382 if (code)
383 goto badcode;
c9155fff
SZ
384 if (discard_sourcequench)
385 break;
984263bc 386 code = PRC_QUENCH;
7d448528 387deliver:
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388 /*
389 * Problem with datagram; advise higher level routines.
390 */
391 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
392 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
393 icmpstat.icps_badlen++;
394 goto freeit;
395 }
3c81cebc 396 icp->icmp_ip.ip_len = ntohs(icp->icmp_ip.ip_len);
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397 /* Discard ICMP's in response to multicast packets */
398 if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr)))
399 goto badcode;
400#ifdef ICMPPRINTFS
401 if (icmpprintfs)
a6ec04bc 402 kprintf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
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MD
403#endif
404 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
405#if 1
406 /*
407 * MTU discovery:
408 * If we got a needfrag and there is a host route to the
409 * original destination, and the MTU is not locked, then
410 * set the MTU in the route to the suggested new value
411 * (if given) and then notify as usual. The ULPs will
412 * notice that the MTU has changed and adapt accordingly.
413 * If no new MTU was suggested, then we guess a new one
f23061d4 414 * less than the current value. If the new MTU is
984263bc
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415 * unreasonably small (arbitrarily set at 296), then
416 * we reset the MTU to the interface value and enable the
417 * lock bit, indicating that we are no longer doing MTU
418 * discovery.
419 */
420 if (code == PRC_MSGSIZE) {
421 struct rtentry *rt;
422 int mtu;
423
f3ed2586 424 rt = rtpurelookup((struct sockaddr *)&icmpsrc);
0c3c561c 425 if (rt != NULL && (rt->rt_flags & RTF_HOST) &&
f23061d4 426 !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
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427 mtu = ntohs(icp->icmp_nextmtu);
428 if (!mtu)
429 mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu,
430 1);
431#ifdef DEBUG_MTUDISC
a6ec04bc 432 kprintf("MTU for %s reduced to %d\n",
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433 inet_ntoa(icmpsrc.sin_addr), mtu);
434#endif
435 if (mtu < 296) {
436 /* rt->rt_rmx.rmx_mtu =
437 rt->rt_ifp->if_mtu; */
438 rt->rt_rmx.rmx_locks |= RTV_MTU;
439 } else if (rt->rt_rmx.rmx_mtu > mtu) {
440 rt->rt_rmx.rmx_mtu = mtu;
441 }
442 }
0c3c561c 443 if (rt != NULL)
f23061d4 444 --rt->rt_refcnt;
984263bc 445 }
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446#endif
447 /*
448 * XXX if the packet contains [IPv4 AH TCP], we can't make a
449 * notification to TCP layer.
450 */
e3873585
SZ
451 so_pru_ctlinput(
452 &inetsw[ip_protox[icp->icmp_ip.ip_p]],
453 code, (struct sockaddr *)&icmpsrc, &icp->icmp_ip);
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454 break;
455
7d448528 456badcode:
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457 icmpstat.icps_badcode++;
458 break;
459
460 case ICMP_ECHO:
461 if (!icmpbmcastecho
462 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
463 icmpstat.icps_bmcastecho++;
464 break;
465 }
466 icp->icmp_type = ICMP_ECHOREPLY;
467#ifdef ICMP_BANDLIM
468 if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0)
469 goto freeit;
470 else
471#endif
472 goto reflect;
473
474 case ICMP_TSTAMP:
475 if (!icmpbmcastecho
476 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
477 icmpstat.icps_bmcasttstamp++;
478 break;
479 }
480 if (icmplen < ICMP_TSLEN) {
481 icmpstat.icps_badlen++;
482 break;
483 }
484 icp->icmp_type = ICMP_TSTAMPREPLY;
485 icp->icmp_rtime = iptime();
486 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
487#ifdef ICMP_BANDLIM
488 if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0)
489 goto freeit;
490 else
491#endif
492 goto reflect;
493
494 case ICMP_MASKREQ:
495 if (icmpmaskrepl == 0)
496 break;
497 /*
498 * We are not able to respond with all ones broadcast
499 * unless we receive it over a point-to-point interface.
500 */
501 if (icmplen < ICMP_MASKLEN)
502 break;
503 switch (ip->ip_dst.s_addr) {
504
505 case INADDR_BROADCAST:
506 case INADDR_ANY:
507 icmpdst.sin_addr = ip->ip_src;
508 break;
509
510 default:
511 icmpdst.sin_addr = ip->ip_dst;
512 }
513 ia = (struct in_ifaddr *)ifaof_ifpforaddr(
514 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
4090d6ff 515 if (ia == NULL)
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MD
516 break;
517 if (ia->ia_ifp == 0)
518 break;
519 icp->icmp_type = ICMP_MASKREPLY;
520 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
521 if (ip->ip_src.s_addr == 0) {
522 if (ia->ia_ifp->if_flags & IFF_BROADCAST)
523 ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr;
524 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
525 ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr;
526 }
527reflect:
528 ip->ip_len += hlen; /* since ip_input deducts this */
529 icmpstat.icps_reflect++;
530 icmpstat.icps_outhist[icp->icmp_type]++;
531 icmp_reflect(m);
002c1265 532 return(IPPROTO_DONE);
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533
534 case ICMP_REDIRECT:
535 if (log_redirect) {
536 u_long src, dst, gw;
537
538 src = ntohl(ip->ip_src.s_addr);
539 dst = ntohl(icp->icmp_ip.ip_dst.s_addr);
540 gw = ntohl(icp->icmp_gwaddr.s_addr);
a6ec04bc 541 kprintf("icmp redirect from %d.%d.%d.%d: "
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MD
542 "%d.%d.%d.%d => %d.%d.%d.%d\n",
543 (int)(src >> 24), (int)((src >> 16) & 0xff),
544 (int)((src >> 8) & 0xff), (int)(src & 0xff),
545 (int)(dst >> 24), (int)((dst >> 16) & 0xff),
546 (int)((dst >> 8) & 0xff), (int)(dst & 0xff),
547 (int)(gw >> 24), (int)((gw >> 16) & 0xff),
548 (int)((gw >> 8) & 0xff), (int)(gw & 0xff));
549 }
550 if (drop_redirect)
551 break;
552 if (code > 3)
553 goto badcode;
554 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
555 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
556 icmpstat.icps_badlen++;
557 break;
558 }
559 /*
560 * Short circuit routing redirects to force
561 * immediate change in the kernel's routing
562 * tables. The message is also handed to anyone
563 * listening on a raw socket (e.g. the routing
564 * daemon for use in updating its tables).
565 */
566 icmpgw.sin_addr = ip->ip_src;
567 icmpdst.sin_addr = icp->icmp_gwaddr;
568#ifdef ICMPPRINTFS
569 if (icmpprintfs) {
1141eb20 570 char buf[sizeof "aaa.bbb.ccc.ddd"];
984263bc 571
1141eb20 572 strcpy(buf, inet_ntoa(icp->icmp_ip.ip_dst));
a6ec04bc 573 kprintf("redirect dst %s to %s\n",
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574 buf, inet_ntoa(icp->icmp_gwaddr));
575 }
576#endif
577 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
578 rtredirect((struct sockaddr *)&icmpsrc,
579 (struct sockaddr *)&icmpdst,
60233e58 580 NULL, RTF_GATEWAY | RTF_HOST,
f6870fe3 581 (struct sockaddr *)&icmpgw);
91be174d 582 kpfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc);
984263bc
MD
583#ifdef IPSEC
584 key_sa_routechange((struct sockaddr *)&icmpsrc);
585#endif
586 break;
587
588 /*
589 * No kernel processing for the following;
590 * just fall through to send to raw listener.
591 */
592 case ICMP_ECHOREPLY:
593 case ICMP_ROUTERADVERT:
594 case ICMP_ROUTERSOLICIT:
595 case ICMP_TSTAMPREPLY:
596 case ICMP_IREQREPLY:
597 case ICMP_MASKREPLY:
598 default:
599 break;
600 }
601
602raw:
002c1265
MD
603 *mp = m;
604 rip_input(mp, offp, proto);
605 return(IPPROTO_DONE);
984263bc
MD
606
607freeit:
608 m_freem(m);
002c1265 609 return(IPPROTO_DONE);
984263bc
MD
610}
611
612/*
613 * Reflect the ip packet back to the source
614 */
615static void
f3f70f0d 616icmp_reflect(struct mbuf *m)
984263bc
MD
617{
618 struct ip *ip = mtod(m, struct ip *);
984263bc 619 struct in_ifaddr *ia;
f8983475 620 struct in_ifaddr_container *iac;
b6b45528
SZ
621 struct ifaddr_container *ifac;
622 struct ifnet *ifp;
984263bc 623 struct in_addr t;
4090d6ff 624 struct mbuf *opts = NULL;
984263bc
MD
625 int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
626 struct route *ro = NULL, rt;
627
628 if (!in_canforward(ip->ip_src) &&
629 ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
630 (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
631 m_freem(m); /* Bad return address */
632 icmpstat.icps_badaddr++;
633 goto done; /* Ip_output() will check for broadcast */
634 }
635 t = ip->ip_dst;
636 ip->ip_dst = ip->ip_src;
b6b45528 637
984263bc 638 ro = &rt;
407e896e 639 bzero(ro, sizeof *ro);
b6b45528 640
984263bc
MD
641 /*
642 * If the incoming packet was addressed directly to us,
643 * use dst as the src for the reply. Otherwise (broadcast
644 * or anonymous), use the address which corresponds
645 * to the incoming interface.
646 */
f8983475
SZ
647 ia = NULL;
648 LIST_FOREACH(iac, INADDR_HASH(t.s_addr), ia_hash) {
649 if (t.s_addr == IA_SIN(iac->ia)->sin_addr.s_addr) {
650 ia = iac->ia;
984263bc 651 goto match;
f8983475
SZ
652 }
653 }
b6b45528
SZ
654 ifp = m->m_pkthdr.rcvif;
655 if (ifp != NULL && (ifp->if_flags & IFF_BROADCAST)) {
656 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
b2632176
SZ
657 struct ifaddr *ifa = ifac->ifa;
658
984263bc
MD
659 if (ifa->ifa_addr->sa_family != AF_INET)
660 continue;
661 ia = ifatoia(ifa);
662 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
663 t.s_addr)
664 goto match;
665 }
666 }
b6b45528
SZ
667 /*
668 * If the packet was transiting through us, use the address of
669 * the interface the packet came through in. If that interface
670 * doesn't have a suitable IP address, the normal selection
671 * criteria apply.
672 */
673 if (icmp_rfi && ifp != NULL) {
674 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
675 struct ifaddr *ifa = ifac->ifa;
676
677 if (ifa->ifa_addr->sa_family != AF_INET)
678 continue;
679 ia = ifatoia(ifa);
680 goto match;
681 }
682 }
683 /*
684 * If the incoming packet was not addressed directly to us, use
685 * designated interface for icmp replies specified by sysctl
686 * net.inet.icmp.reply_src (default not set). Otherwise continue
687 * with normal source selection.
688 */
689 if (icmp_reply_src[0] != '\0' && (ifp = ifunit(icmp_reply_src))) {
690 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
691 struct ifaddr *ifa = ifac->ifa;
692
693 if (ifa->ifa_addr->sa_family != AF_INET)
694 continue;
695 ia = ifatoia(ifa);
696 goto match;
697 }
698 }
699 /*
700 * If the packet was transiting through us, use the address of
701 * the interface that is the closest to the packet source.
702 * When we don't have a route back to the packet source, stop here
703 * and drop the packet.
704 */
984263bc 705 ia = ip_rtaddr(ip->ip_dst, ro);
984263bc
MD
706 if (ia == NULL) {
707 m_freem(m);
708 icmpstat.icps_noroute++;
709 goto done;
710 }
711match:
712 t = IA_SIN(ia)->sin_addr;
713 ip->ip_src = t;
714 ip->ip_ttl = ip_defttl;
715
716 if (optlen > 0) {
2256ba69 717 u_char *cp;
984263bc
MD
718 int opt, cnt;
719 u_int len;
720
721 /*
722 * Retrieve any source routing from the incoming packet;
723 * add on any record-route or timestamp options.
724 */
725 cp = (u_char *) (ip + 1);
4090d6ff 726 if ((opts = ip_srcroute(m)) == NULL &&
74f1caca 727 (opts = m_gethdr(MB_DONTWAIT, MT_HEADER))) {
984263bc
MD
728 opts->m_len = sizeof(struct in_addr);
729 mtod(opts, struct in_addr *)->s_addr = 0;
730 }
731 if (opts) {
732#ifdef ICMPPRINTFS
f23061d4 733 if (icmpprintfs)
a6ec04bc 734 kprintf("icmp_reflect optlen %d rt %d => ",
f23061d4 735 optlen, opts->m_len);
984263bc 736#endif
f23061d4
JH
737 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
738 opt = cp[IPOPT_OPTVAL];
739 if (opt == IPOPT_EOL)
740 break;
741 if (opt == IPOPT_NOP)
742 len = 1;
743 else {
407e896e 744 if (cnt < IPOPT_OLEN + sizeof *cp)
f23061d4
JH
745 break;
746 len = cp[IPOPT_OLEN];
407e896e 747 if (len < IPOPT_OLEN + sizeof *cp ||
f23061d4
JH
748 len > cnt)
749 break;
750 }
751 /*
752 * Should check for overflow, but it
753 * "can't happen".
754 */
755 if (opt == IPOPT_RR || opt == IPOPT_TS ||
756 opt == IPOPT_SECURITY) {
407e896e 757 bcopy(cp,
f23061d4
JH
758 mtod(opts, caddr_t) + opts->m_len,
759 len);
760 opts->m_len += len;
761 }
762 }
763 /* Terminate & pad, if necessary */
764 cnt = opts->m_len % 4;
765 if (cnt) {
766 for (; cnt < 4; cnt++) {
767 *(mtod(opts, caddr_t) + opts->m_len) =
768 IPOPT_EOL;
769 opts->m_len++;
770 }
771 }
984263bc 772#ifdef ICMPPRINTFS
f23061d4 773 if (icmpprintfs)
a6ec04bc 774 kprintf("%d\n", opts->m_len);
984263bc
MD
775#endif
776 }
777 /*
778 * Now strip out original options by copying rest of first
779 * mbuf's data back, and adjust the IP length.
780 */
781 ip->ip_len -= optlen;
782 ip->ip_vhl = IP_VHL_BORING;
783 m->m_len -= optlen;
784 if (m->m_flags & M_PKTHDR)
785 m->m_pkthdr.len -= optlen;
786 optlen += sizeof(struct ip);
407e896e
JH
787 bcopy((caddr_t)ip + optlen, ip + 1,
788 m->m_len - sizeof(struct ip));
984263bc 789 }
f2c2ec09 790 m->m_pkthdr.fw_flags &= FW_MBUF_GENERATED;
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MD
791 m->m_flags &= ~(M_BCAST|M_MCAST);
792 icmp_send(m, opts, ro);
793done:
794 if (opts)
f23061d4 795 m_free(opts);
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MD
796 if (ro && ro->ro_rt)
797 RTFREE(ro->ro_rt);
798}
799
800/*
801 * Send an icmp packet back to the ip level,
802 * after supplying a checksum.
803 */
804static void
f3f70f0d 805icmp_send(struct mbuf *m, struct mbuf *opts, struct route *rt)
984263bc 806{
2256ba69 807 struct ip *ip = mtod(m, struct ip *);
2256ba69 808 struct icmp *icp;
002c1265 809 int hlen;
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MD
810
811 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
812 m->m_data += hlen;
813 m->m_len -= hlen;
814 icp = mtod(m, struct icmp *);
815 icp->icmp_cksum = 0;
816 icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
817 m->m_data -= hlen;
818 m->m_len += hlen;
60233e58 819 m->m_pkthdr.rcvif = NULL;
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MD
820#ifdef ICMPPRINTFS
821 if (icmpprintfs) {
1141eb20
JH
822 char buf[sizeof "aaa.bbb.ccc.ddd"];
823
984263bc 824 strcpy(buf, inet_ntoa(ip->ip_dst));
a6ec04bc 825 kprintf("icmp_send dst %s src %s\n", buf, inet_ntoa(ip->ip_src));
984263bc
MD
826 }
827#endif
f23061d4 828 ip_output(m, opts, rt, 0, NULL, NULL);
984263bc
MD
829}
830
831n_time
f3f70f0d 832iptime(void)
984263bc
MD
833{
834 struct timeval atv;
835 u_long t;
836
837 getmicrotime(&atv);
838 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
839 return (htonl(t));
840}
841
842#if 1
843/*
844 * Return the next larger or smaller MTU plateau (table from RFC 1191)
845 * given current value MTU. If DIR is less than zero, a larger plateau
846 * is returned; otherwise, a smaller value is returned.
847 */
7d448528
JH
848int
849ip_next_mtu(int mtu, int dir)
984263bc
MD
850{
851 static int mtutab[] = {
852 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296,
853 68, 0
854 };
855 int i;
856
857 for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
858 if (mtu >= mtutab[i])
859 break;
860 }
861
862 if (dir < 0) {
863 if (i == 0) {
864 return 0;
865 } else {
866 return mtutab[i - 1];
867 }
868 } else {
869 if (mtutab[i] == 0) {
870 return 0;
871 } else if(mtu > mtutab[i]) {
872 return mtutab[i];
873 } else {
874 return mtutab[i + 1];
875 }
876 }
877}
878#endif
879
880#ifdef ICMP_BANDLIM
984263bc
MD
881/*
882 * badport_bandlim() - check for ICMP bandwidth limit
883 *
884 * Return 0 if it is ok to send an ICMP error response, -1 if we have
f23061d4 885 * hit our bandwidth limit and it is not ok.
984263bc
MD
886 *
887 * If icmplim is <= 0, the feature is disabled and 0 is returned.
888 *
889 * For now we separate the TCP and UDP subsystems w/ different 'which'
890 * values. We may eventually remove this separation (and simplify the
891 * code further).
892 *
893 * Note that the printing of the error message is delayed so we can
894 * properly print the icmp error rate that the system was trying to do
895 * (i.e. 22000/100 pps, etc...). This can cause long delays in printing
f23061d4 896 * the 'final' error, but it doesn't make sense to solve the printing
984263bc
MD
897 * delay with more complex code.
898 */
984263bc
MD
899int
900badport_bandlim(int which)
901{
902 static int lticks[BANDLIM_MAX + 1];
903 static int lpackets[BANDLIM_MAX + 1];
904 int dticks;
905 const char *bandlimittype[] = {
906 "Limiting icmp unreach response",
907 "Limiting icmp ping response",
908 "Limiting icmp tstamp response",
909 "Limiting closed port RST response",
910 "Limiting open port RST response"
911 };
912
913 /*
914 * Return ok status if feature disabled or argument out of
915 * ranage.
916 */
917
918 if (icmplim <= 0 || which > BANDLIM_MAX || which < 0)
919 return(0);
920 dticks = ticks - lticks[which];
921
922 /*
923 * reset stats when cumulative dt exceeds one second.
924 */
925
926 if ((unsigned int)dticks > hz) {
927 if (lpackets[which] > icmplim && icmplim_output) {
a6ec04bc 928 kprintf("%s from %d to %d packets per second\n",
984263bc
MD
929 bandlimittype[which],
930 lpackets[which],
931 icmplim
932 );
933 }
934 lticks[which] = ticks;
935 lpackets[which] = 0;
936 }
937
938 /*
939 * bump packet count
940 */
941
942 if (++lpackets[which] > icmplim) {
943 return(-1);
944 }
945 return(0);
946}
984263bc 947#endif