1 | /* $NetBSD: ip_icmp.c,v 1.153 2016/10/25 02:45:09 ozaki-r Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. |
5 | * All rights reserved. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions |
9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * 3. Neither the name of the project nor the names of its contributors |
16 | * may be used to endorse or promote products derived from this software |
17 | * without specific prior written permission. |
18 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND |
20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE |
23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
29 | * SUCH DAMAGE. |
30 | */ |
31 | |
32 | /*- |
33 | * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc. |
34 | * All rights reserved. |
35 | * |
36 | * This code is derived from software contributed to The NetBSD Foundation |
37 | * by Public Access Networks Corporation ("Panix"). It was developed under |
38 | * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. |
39 | * |
40 | * This code is derived from software contributed to The NetBSD Foundation |
41 | * by Jason R. Thorpe of Zembu Labs, Inc. |
42 | * |
43 | * Redistribution and use in source and binary forms, with or without |
44 | * modification, are permitted provided that the following conditions |
45 | * are met: |
46 | * 1. Redistributions of source code must retain the above copyright |
47 | * notice, this list of conditions and the following disclaimer. |
48 | * 2. Redistributions in binary form must reproduce the above copyright |
49 | * notice, this list of conditions and the following disclaimer in the |
50 | * documentation and/or other materials provided with the distribution. |
51 | * |
52 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
53 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
54 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
55 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
56 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
57 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
58 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
59 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
60 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
61 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
62 | * POSSIBILITY OF SUCH DAMAGE. |
63 | */ |
64 | |
65 | /* |
66 | * Copyright (c) 1982, 1986, 1988, 1993 |
67 | * The Regents of the University of California. All rights reserved. |
68 | * |
69 | * Redistribution and use in source and binary forms, with or without |
70 | * modification, are permitted provided that the following conditions |
71 | * are met: |
72 | * 1. Redistributions of source code must retain the above copyright |
73 | * notice, this list of conditions and the following disclaimer. |
74 | * 2. Redistributions in binary form must reproduce the above copyright |
75 | * notice, this list of conditions and the following disclaimer in the |
76 | * documentation and/or other materials provided with the distribution. |
77 | * 3. Neither the name of the University nor the names of its contributors |
78 | * may be used to endorse or promote products derived from this software |
79 | * without specific prior written permission. |
80 | * |
81 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
82 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
83 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
84 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
85 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
86 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
87 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
88 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
89 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
90 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
91 | * SUCH DAMAGE. |
92 | * |
93 | * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 |
94 | */ |
95 | |
96 | #include <sys/cdefs.h> |
97 | __KERNEL_RCSID(0, "$NetBSD: ip_icmp.c,v 1.153 2016/10/25 02:45:09 ozaki-r Exp $" ); |
98 | |
99 | #ifdef _KERNEL_OPT |
100 | #include "opt_ipsec.h" |
101 | #endif |
102 | |
103 | #include <sys/param.h> |
104 | #include <sys/systm.h> |
105 | #include <sys/mbuf.h> |
106 | #include <sys/protosw.h> |
107 | #include <sys/socket.h> |
108 | #include <sys/kmem.h> |
109 | #include <sys/time.h> |
110 | #include <sys/kernel.h> |
111 | #include <sys/syslog.h> |
112 | #include <sys/sysctl.h> |
113 | |
114 | #include <net/if.h> |
115 | #include <net/route.h> |
116 | |
117 | #include <netinet/in.h> |
118 | #include <netinet/in_systm.h> |
119 | #include <netinet/in_var.h> |
120 | #include <netinet/ip.h> |
121 | #include <netinet/ip_icmp.h> |
122 | #include <netinet/ip_var.h> |
123 | #include <netinet/in_pcb.h> |
124 | #include <netinet/in_proto.h> |
125 | #include <netinet/icmp_var.h> |
126 | #include <netinet/icmp_private.h> |
127 | |
128 | #ifdef IPSEC |
129 | #include <netipsec/ipsec.h> |
130 | #include <netipsec/key.h> |
131 | #endif /* IPSEC*/ |
132 | |
133 | /* |
134 | * ICMP routines: error generation, receive packet processing, and |
135 | * routines to turnaround packets back to the originator, and |
136 | * host table maintenance routines. |
137 | */ |
138 | |
139 | int icmpmaskrepl = 0; |
140 | int icmpbmcastecho = 0; |
141 | #ifdef ICMPPRINTFS |
142 | int icmpprintfs = 0; |
143 | #endif |
144 | int icmpreturndatabytes = 8; |
145 | |
146 | percpu_t *icmpstat_percpu; |
147 | |
148 | /* |
149 | * List of callbacks to notify when Path MTU changes are made. |
150 | */ |
151 | struct icmp_mtudisc_callback { |
152 | LIST_ENTRY(icmp_mtudisc_callback) mc_list; |
153 | void (*mc_func)(struct in_addr); |
154 | }; |
155 | |
156 | LIST_HEAD(, icmp_mtudisc_callback) icmp_mtudisc_callbacks = |
157 | LIST_HEAD_INITIALIZER(&icmp_mtudisc_callbacks); |
158 | |
159 | #if 0 |
160 | static u_int ip_next_mtu(u_int, int); |
161 | #else |
162 | /*static*/ u_int ip_next_mtu(u_int, int); |
163 | #endif |
164 | |
165 | extern int icmperrppslim; |
166 | static int icmperrpps_count = 0; |
167 | static struct timeval icmperrppslim_last; |
168 | static int icmp_rediraccept = 1; |
169 | static int icmp_redirtimeout = 600; |
170 | static struct rttimer_queue *icmp_redirect_timeout_q = NULL; |
171 | |
172 | static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *); |
173 | static void icmp_redirect_timeout(struct rtentry *, struct rttimer *); |
174 | |
175 | static void sysctl_netinet_icmp_setup(struct sysctllog **); |
176 | |
177 | void |
178 | icmp_init(void) |
179 | { |
180 | |
181 | sysctl_netinet_icmp_setup(NULL); |
182 | |
183 | /* |
184 | * This is only useful if the user initializes redirtimeout to |
185 | * something other than zero. |
186 | */ |
187 | if (icmp_redirtimeout != 0) { |
188 | icmp_redirect_timeout_q = |
189 | rt_timer_queue_create(icmp_redirtimeout); |
190 | } |
191 | |
192 | icmpstat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP_NSTATS); |
193 | } |
194 | |
195 | /* |
196 | * Register a Path MTU Discovery callback. |
197 | */ |
198 | void |
199 | icmp_mtudisc_callback_register(void (*func)(struct in_addr)) |
200 | { |
201 | struct icmp_mtudisc_callback *mc; |
202 | |
203 | for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; |
204 | mc = LIST_NEXT(mc, mc_list)) { |
205 | if (mc->mc_func == func) |
206 | return; |
207 | } |
208 | |
209 | mc = kmem_alloc(sizeof(*mc), KM_SLEEP); |
210 | mc->mc_func = func; |
211 | LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, mc, mc_list); |
212 | } |
213 | |
214 | /* |
215 | * Generate an error packet of type error |
216 | * in response to bad packet ip. |
217 | */ |
218 | void |
219 | icmp_error(struct mbuf *n, int type, int code, n_long dest, |
220 | int destmtu) |
221 | { |
222 | struct ip *oip = mtod(n, struct ip *), *nip; |
223 | unsigned oiplen = oip->ip_hl << 2; |
224 | struct icmp *icp; |
225 | struct mbuf *m; |
226 | struct m_tag *mtag; |
227 | unsigned icmplen, mblen; |
228 | |
229 | #ifdef ICMPPRINTFS |
230 | if (icmpprintfs) |
231 | printf("icmp_error(%p, type:%d, code:%d)\n" , oip, type, code); |
232 | #endif |
233 | if (type != ICMP_REDIRECT) |
234 | ICMP_STATINC(ICMP_STAT_ERROR); |
235 | /* |
236 | * Don't send error if the original packet was encrypted. |
237 | * Don't send error if not the first fragment of message. |
238 | * Don't error if the old packet protocol was ICMP |
239 | * error message, only known informational types. |
240 | */ |
241 | if (n->m_flags & M_DECRYPTED) |
242 | goto freeit; |
243 | if (oip->ip_off &~ htons(IP_MF|IP_DF)) |
244 | goto freeit; |
245 | if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && |
246 | n->m_len >= oiplen + ICMP_MINLEN && |
247 | !ICMP_INFOTYPE(((struct icmp *)((char *)oip + oiplen))->icmp_type)) { |
248 | ICMP_STATINC(ICMP_STAT_OLDICMP); |
249 | goto freeit; |
250 | } |
251 | /* Don't send error in response to a multicast or broadcast packet */ |
252 | if (n->m_flags & (M_BCAST|M_MCAST)) |
253 | goto freeit; |
254 | |
255 | /* |
256 | * First, do a rate limitation check. |
257 | */ |
258 | if (icmp_ratelimit(&oip->ip_src, type, code)) { |
259 | /* XXX stat */ |
260 | goto freeit; |
261 | } |
262 | |
263 | /* |
264 | * Now, formulate icmp message |
265 | */ |
266 | icmplen = oiplen + min(icmpreturndatabytes, |
267 | ntohs(oip->ip_len) - oiplen); |
268 | /* |
269 | * Defend against mbuf chains shorter than oip->ip_len - oiplen: |
270 | */ |
271 | mblen = 0; |
272 | for (m = n; m && (mblen < icmplen); m = m->m_next) |
273 | mblen += m->m_len; |
274 | icmplen = min(mblen, icmplen); |
275 | |
276 | /* |
277 | * As we are not required to return everything we have, |
278 | * we return whatever we can return at ease. |
279 | * |
280 | * Note that ICMP datagrams longer than 576 octets are out of spec |
281 | * according to RFC1812; the limit on icmpreturndatabytes below in |
282 | * icmp_sysctl will keep things below that limit. |
283 | */ |
284 | |
285 | KASSERT(ICMP_MINLEN <= MCLBYTES); |
286 | |
287 | if (icmplen + ICMP_MINLEN > MCLBYTES) |
288 | icmplen = MCLBYTES - ICMP_MINLEN; |
289 | |
290 | m = m_gethdr(M_DONTWAIT, MT_HEADER); |
291 | if (m && (icmplen + ICMP_MINLEN > MHLEN)) { |
292 | MCLGET(m, M_DONTWAIT); |
293 | if ((m->m_flags & M_EXT) == 0) { |
294 | m_freem(m); |
295 | m = NULL; |
296 | } |
297 | } |
298 | if (m == NULL) |
299 | goto freeit; |
300 | MCLAIM(m, n->m_owner); |
301 | m->m_len = icmplen + ICMP_MINLEN; |
302 | if ((m->m_flags & M_EXT) == 0) |
303 | MH_ALIGN(m, m->m_len); |
304 | else { |
305 | m->m_data += sizeof(struct ip); |
306 | m->m_len -= sizeof(struct ip); |
307 | } |
308 | icp = mtod(m, struct icmp *); |
309 | if ((u_int)type > ICMP_MAXTYPE) |
310 | panic("icmp_error" ); |
311 | ICMP_STATINC(ICMP_STAT_OUTHIST + type); |
312 | icp->icmp_type = type; |
313 | if (type == ICMP_REDIRECT) |
314 | icp->icmp_gwaddr.s_addr = dest; |
315 | else { |
316 | icp->icmp_void = 0; |
317 | /* |
318 | * The following assignments assume an overlay with the |
319 | * zeroed icmp_void field. |
320 | */ |
321 | if (type == ICMP_PARAMPROB) { |
322 | icp->icmp_pptr = code; |
323 | code = 0; |
324 | } else if (type == ICMP_UNREACH && |
325 | code == ICMP_UNREACH_NEEDFRAG && destmtu) |
326 | icp->icmp_nextmtu = htons(destmtu); |
327 | } |
328 | |
329 | icp->icmp_code = code; |
330 | m_copydata(n, 0, icmplen, (void *)&icp->icmp_ip); |
331 | |
332 | /* |
333 | * Now, copy old ip header (without options) |
334 | * in front of icmp message. |
335 | */ |
336 | if ((m->m_flags & M_EXT) == 0 && |
337 | m->m_data - sizeof(struct ip) < m->m_pktdat) |
338 | panic("icmp len" ); |
339 | m->m_data -= sizeof(struct ip); |
340 | m->m_len += sizeof(struct ip); |
341 | m->m_pkthdr.len = m->m_len; |
342 | m_copy_rcvif(m, n); |
343 | nip = mtod(m, struct ip *); |
344 | /* ip_v set in ip_output */ |
345 | nip->ip_hl = sizeof(struct ip) >> 2; |
346 | nip->ip_tos = 0; |
347 | nip->ip_len = htons(m->m_len); |
348 | /* ip_id set in ip_output */ |
349 | nip->ip_off = htons(0); |
350 | /* ip_ttl set in icmp_reflect */ |
351 | nip->ip_p = IPPROTO_ICMP; |
352 | nip->ip_src = oip->ip_src; |
353 | nip->ip_dst = oip->ip_dst; |
354 | /* move PF m_tag to new packet, if it exists */ |
355 | mtag = m_tag_find(n, PACKET_TAG_PF, NULL); |
356 | if (mtag != NULL) { |
357 | m_tag_unlink(n, mtag); |
358 | m_tag_prepend(m, mtag); |
359 | } |
360 | icmp_reflect(m); |
361 | |
362 | freeit: |
363 | m_freem(n); |
364 | } |
365 | |
366 | struct sockaddr_in icmpsrc = { |
367 | .sin_len = sizeof (struct sockaddr_in), |
368 | .sin_family = AF_INET, |
369 | }; |
370 | static struct sockaddr_in icmpdst = { |
371 | .sin_len = sizeof (struct sockaddr_in), |
372 | .sin_family = AF_INET, |
373 | }; |
374 | static struct sockaddr_in icmpgw = { |
375 | .sin_len = sizeof (struct sockaddr_in), |
376 | .sin_family = AF_INET, |
377 | }; |
378 | struct sockaddr_in icmpmask = { |
379 | .sin_len = 8, |
380 | .sin_family = 0, |
381 | }; |
382 | |
383 | /* |
384 | * Process a received ICMP message. |
385 | */ |
386 | void |
387 | icmp_input(struct mbuf *m, ...) |
388 | { |
389 | int proto; |
390 | struct icmp *icp; |
391 | struct ip *ip = mtod(m, struct ip *); |
392 | int icmplen; |
393 | int i; |
394 | struct in_ifaddr *ia; |
395 | void *(*ctlfunc)(int, const struct sockaddr *, void *); |
396 | int code; |
397 | int hlen; |
398 | va_list ap; |
399 | struct rtentry *rt; |
400 | |
401 | va_start(ap, m); |
402 | hlen = va_arg(ap, int); |
403 | proto = va_arg(ap, int); |
404 | va_end(ap); |
405 | |
406 | /* |
407 | * Locate icmp structure in mbuf, and check |
408 | * that not corrupted and of at least minimum length. |
409 | */ |
410 | icmplen = ntohs(ip->ip_len) - hlen; |
411 | #ifdef ICMPPRINTFS |
412 | if (icmpprintfs) { |
413 | char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; |
414 | printf("icmp_input from `%s' to `%s', len %d\n" , |
415 | IN_PRINT(sbuf, &ip->ip_src), IN_PRINT(dbuf, &ip->ip_dst), |
416 | icmplen); |
417 | } |
418 | #endif |
419 | if (icmplen < ICMP_MINLEN) { |
420 | ICMP_STATINC(ICMP_STAT_TOOSHORT); |
421 | goto freeit; |
422 | } |
423 | i = hlen + min(icmplen, ICMP_ADVLENMIN); |
424 | if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == NULL) { |
425 | ICMP_STATINC(ICMP_STAT_TOOSHORT); |
426 | return; |
427 | } |
428 | ip = mtod(m, struct ip *); |
429 | m->m_len -= hlen; |
430 | m->m_data += hlen; |
431 | icp = mtod(m, struct icmp *); |
432 | /* Don't need to assert alignment, here. */ |
433 | if (in_cksum(m, icmplen)) { |
434 | ICMP_STATINC(ICMP_STAT_CHECKSUM); |
435 | goto freeit; |
436 | } |
437 | m->m_len += hlen; |
438 | m->m_data -= hlen; |
439 | |
440 | #ifdef ICMPPRINTFS |
441 | /* |
442 | * Message type specific processing. |
443 | */ |
444 | if (icmpprintfs) |
445 | printf("icmp_input(type:%d, code:%d)\n" , icp->icmp_type, |
446 | icp->icmp_code); |
447 | #endif |
448 | if (icp->icmp_type > ICMP_MAXTYPE) |
449 | goto raw; |
450 | ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type); |
451 | code = icp->icmp_code; |
452 | switch (icp->icmp_type) { |
453 | |
454 | case ICMP_UNREACH: |
455 | switch (code) { |
456 | case ICMP_UNREACH_PROTOCOL: |
457 | code = PRC_UNREACH_PROTOCOL; |
458 | break; |
459 | |
460 | case ICMP_UNREACH_PORT: |
461 | code = PRC_UNREACH_PORT; |
462 | break; |
463 | |
464 | case ICMP_UNREACH_SRCFAIL: |
465 | code = PRC_UNREACH_SRCFAIL; |
466 | break; |
467 | |
468 | case ICMP_UNREACH_NEEDFRAG: |
469 | code = PRC_MSGSIZE; |
470 | break; |
471 | |
472 | case ICMP_UNREACH_NET: |
473 | case ICMP_UNREACH_NET_UNKNOWN: |
474 | case ICMP_UNREACH_NET_PROHIB: |
475 | case ICMP_UNREACH_TOSNET: |
476 | code = PRC_UNREACH_NET; |
477 | break; |
478 | |
479 | case ICMP_UNREACH_HOST: |
480 | case ICMP_UNREACH_HOST_UNKNOWN: |
481 | case ICMP_UNREACH_ISOLATED: |
482 | case ICMP_UNREACH_HOST_PROHIB: |
483 | case ICMP_UNREACH_TOSHOST: |
484 | case ICMP_UNREACH_ADMIN_PROHIBIT: |
485 | case ICMP_UNREACH_HOST_PREC: |
486 | case ICMP_UNREACH_PREC_CUTOFF: |
487 | code = PRC_UNREACH_HOST; |
488 | break; |
489 | |
490 | default: |
491 | goto badcode; |
492 | } |
493 | goto deliver; |
494 | |
495 | case ICMP_TIMXCEED: |
496 | if (code > 1) |
497 | goto badcode; |
498 | code += PRC_TIMXCEED_INTRANS; |
499 | goto deliver; |
500 | |
501 | case ICMP_PARAMPROB: |
502 | if (code > 1) |
503 | goto badcode; |
504 | code = PRC_PARAMPROB; |
505 | goto deliver; |
506 | |
507 | case ICMP_SOURCEQUENCH: |
508 | if (code) |
509 | goto badcode; |
510 | code = PRC_QUENCH; |
511 | goto deliver; |
512 | |
513 | deliver: |
514 | /* |
515 | * Problem with datagram; advise higher level routines. |
516 | */ |
517 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || |
518 | icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { |
519 | ICMP_STATINC(ICMP_STAT_BADLEN); |
520 | goto freeit; |
521 | } |
522 | if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) |
523 | goto badcode; |
524 | #ifdef ICMPPRINTFS |
525 | if (icmpprintfs) |
526 | printf("deliver to protocol %d\n" , icp->icmp_ip.ip_p); |
527 | #endif |
528 | icmpsrc.sin_addr = icp->icmp_ip.ip_dst; |
529 | ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; |
530 | if (ctlfunc) |
531 | (void) (*ctlfunc)(code, sintosa(&icmpsrc), |
532 | &icp->icmp_ip); |
533 | break; |
534 | |
535 | badcode: |
536 | ICMP_STATINC(ICMP_STAT_BADCODE); |
537 | break; |
538 | |
539 | case ICMP_ECHO: |
540 | if (!icmpbmcastecho && |
541 | (m->m_flags & (M_MCAST | M_BCAST)) != 0) { |
542 | ICMP_STATINC(ICMP_STAT_BMCASTECHO); |
543 | break; |
544 | } |
545 | icp->icmp_type = ICMP_ECHOREPLY; |
546 | goto reflect; |
547 | |
548 | case ICMP_TSTAMP: |
549 | if (icmplen < ICMP_TSLEN) { |
550 | ICMP_STATINC(ICMP_STAT_BADLEN); |
551 | break; |
552 | } |
553 | if (!icmpbmcastecho && |
554 | (m->m_flags & (M_MCAST | M_BCAST)) != 0) { |
555 | ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); |
556 | break; |
557 | } |
558 | icp->icmp_type = ICMP_TSTAMPREPLY; |
559 | icp->icmp_rtime = iptime(); |
560 | icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ |
561 | goto reflect; |
562 | |
563 | case ICMP_MASKREQ: { |
564 | struct ifnet *rcvif; |
565 | int s, ss; |
566 | struct ifaddr *ifa; |
567 | |
568 | if (icmpmaskrepl == 0) |
569 | break; |
570 | /* |
571 | * We are not able to respond with all ones broadcast |
572 | * unless we receive it over a point-to-point interface. |
573 | */ |
574 | if (icmplen < ICMP_MASKLEN) { |
575 | ICMP_STATINC(ICMP_STAT_BADLEN); |
576 | break; |
577 | } |
578 | if (ip->ip_dst.s_addr == INADDR_BROADCAST || |
579 | in_nullhost(ip->ip_dst)) |
580 | icmpdst.sin_addr = ip->ip_src; |
581 | else |
582 | icmpdst.sin_addr = ip->ip_dst; |
583 | ss = pserialize_read_enter(); |
584 | rcvif = m_get_rcvif(m, &s); |
585 | ifa = ifaof_ifpforaddr(sintosa(&icmpdst), rcvif); |
586 | m_put_rcvif(rcvif, &s); |
587 | if (ifa == NULL) { |
588 | pserialize_read_exit(ss); |
589 | break; |
590 | } |
591 | ia = ifatoia(ifa); |
592 | icp->icmp_type = ICMP_MASKREPLY; |
593 | icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; |
594 | if (in_nullhost(ip->ip_src)) { |
595 | if (ia->ia_ifp->if_flags & IFF_BROADCAST) |
596 | ip->ip_src = ia->ia_broadaddr.sin_addr; |
597 | else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) |
598 | ip->ip_src = ia->ia_dstaddr.sin_addr; |
599 | } |
600 | pserialize_read_exit(ss); |
601 | reflect: |
602 | { |
603 | uint64_t *icps = percpu_getref(icmpstat_percpu); |
604 | icps[ICMP_STAT_REFLECT]++; |
605 | icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; |
606 | percpu_putref(icmpstat_percpu); |
607 | } |
608 | icmp_reflect(m); |
609 | return; |
610 | } |
611 | |
612 | case ICMP_REDIRECT: |
613 | if (code > 3) |
614 | goto badcode; |
615 | if (icmp_rediraccept == 0) |
616 | goto freeit; |
617 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || |
618 | icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { |
619 | ICMP_STATINC(ICMP_STAT_BADLEN); |
620 | break; |
621 | } |
622 | /* |
623 | * Short circuit routing redirects to force |
624 | * immediate change in the kernel's routing |
625 | * tables. The message is also handed to anyone |
626 | * listening on a raw socket (e.g. the routing |
627 | * daemon for use in updating its tables). |
628 | */ |
629 | icmpgw.sin_addr = ip->ip_src; |
630 | icmpdst.sin_addr = icp->icmp_gwaddr; |
631 | #ifdef ICMPPRINTFS |
632 | if (icmpprintfs) { |
633 | char gbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; |
634 | printf("redirect dst `%s' to `%s'\n" , |
635 | IN_PRINT(dbuf, &icp->icmp_ip.ip_dst), |
636 | IN_PRINT(gbuf, &icp->icmp_gwaddr)); |
637 | } |
638 | #endif |
639 | icmpsrc.sin_addr = icp->icmp_ip.ip_dst; |
640 | rt = NULL; |
641 | rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst), |
642 | NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt); |
643 | if (rt != NULL && icmp_redirtimeout != 0) { |
644 | i = rt_timer_add(rt, icmp_redirect_timeout, |
645 | icmp_redirect_timeout_q); |
646 | if (i) { |
647 | char buf[INET_ADDRSTRLEN]; |
648 | log(LOG_ERR, "ICMP: redirect failed to " |
649 | "register timeout for route to %s, " |
650 | "code %d\n" , |
651 | IN_PRINT(buf, &icp->icmp_ip.ip_dst), i); |
652 | } |
653 | } |
654 | if (rt != NULL) |
655 | rtfree(rt); |
656 | |
657 | pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); |
658 | #if defined(IPSEC) |
659 | if (ipsec_used) |
660 | key_sa_routechange((struct sockaddr *)&icmpsrc); |
661 | #endif |
662 | break; |
663 | |
664 | /* |
665 | * No kernel processing for the following; |
666 | * just fall through to send to raw listener. |
667 | */ |
668 | case ICMP_ECHOREPLY: |
669 | case ICMP_ROUTERADVERT: |
670 | case ICMP_ROUTERSOLICIT: |
671 | case ICMP_TSTAMPREPLY: |
672 | case ICMP_IREQREPLY: |
673 | case ICMP_MASKREPLY: |
674 | default: |
675 | break; |
676 | } |
677 | |
678 | raw: |
679 | rip_input(m, hlen, proto); |
680 | return; |
681 | |
682 | freeit: |
683 | m_freem(m); |
684 | return; |
685 | } |
686 | |
687 | /* |
688 | * Reflect the ip packet back to the source |
689 | */ |
690 | void |
691 | icmp_reflect(struct mbuf *m) |
692 | { |
693 | struct ip *ip = mtod(m, struct ip *); |
694 | struct in_ifaddr *ia; |
695 | struct ifaddr *ifa; |
696 | struct sockaddr_in *sin; |
697 | struct in_addr t; |
698 | struct mbuf *opts = NULL; |
699 | int optlen = (ip->ip_hl << 2) - sizeof(struct ip); |
700 | struct ifnet *rcvif; |
701 | struct psref psref, psref_ia; |
702 | int s; |
703 | int bound; |
704 | |
705 | bound = curlwp_bind(); |
706 | |
707 | if (!in_canforward(ip->ip_src) && |
708 | ((ip->ip_src.s_addr & IN_CLASSA_NET) != |
709 | htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { |
710 | m_freem(m); /* Bad return address */ |
711 | goto done; /* ip_output() will check for broadcast */ |
712 | } |
713 | t = ip->ip_dst; |
714 | ip->ip_dst = ip->ip_src; |
715 | /* |
716 | * If the incoming packet was addressed directly to us, use |
717 | * dst as the src for the reply. Otherwise (broadcast or |
718 | * anonymous), use an address which corresponds to the |
719 | * incoming interface, with a preference for the address which |
720 | * corresponds to the route to the destination of the ICMP. |
721 | */ |
722 | |
723 | /* Look for packet addressed to us */ |
724 | ia = in_get_ia_psref(t, &psref_ia); |
725 | if (ia && (ia->ia4_flags & IN_IFF_NOTREADY)) { |
726 | ia4_release(ia, &psref_ia); |
727 | ia = NULL; |
728 | } |
729 | |
730 | rcvif = m_get_rcvif_psref(m, &psref); |
731 | |
732 | /* look for packet sent to broadcast address */ |
733 | if (ia == NULL && rcvif && |
734 | (rcvif->if_flags & IFF_BROADCAST)) { |
735 | s = pserialize_read_enter(); |
736 | IFADDR_READER_FOREACH(ifa, rcvif) { |
737 | if (ifa->ifa_addr->sa_family != AF_INET) |
738 | continue; |
739 | if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) { |
740 | ia = ifatoia(ifa); |
741 | if ((ia->ia4_flags & IN_IFF_NOTREADY) == 0) |
742 | break; |
743 | ia = NULL; |
744 | } |
745 | } |
746 | if (ia != NULL) |
747 | ia4_acquire(ia, &psref_ia); |
748 | pserialize_read_exit(s); |
749 | } |
750 | |
751 | sin = ia ? &ia->ia_addr : NULL; |
752 | |
753 | icmpdst.sin_addr = t; |
754 | |
755 | /* |
756 | * if the packet is addressed somewhere else, compute the |
757 | * source address for packets routed back to the source, and |
758 | * use that, if it's an address on the interface which |
759 | * received the packet |
760 | */ |
761 | if (sin == NULL && rcvif) { |
762 | struct sockaddr_in sin_dst; |
763 | struct route icmproute; |
764 | int errornum; |
765 | |
766 | sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); |
767 | memset(&icmproute, 0, sizeof(icmproute)); |
768 | errornum = 0; |
769 | ia = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum, |
770 | &psref_ia); |
771 | /* errornum is never used */ |
772 | rtcache_free(&icmproute); |
773 | /* check to make sure sin is a source address on rcvif */ |
774 | if (ia != NULL) { |
775 | sin = &ia->ia_addr; |
776 | t = sin->sin_addr; |
777 | sin = NULL; |
778 | ia4_release(ia, &psref_ia); |
779 | ia = in_get_ia_on_iface_psref(t, rcvif, &psref_ia); |
780 | if (ia != NULL) |
781 | sin = &ia->ia_addr; |
782 | } |
783 | } |
784 | |
785 | /* |
786 | * if it was not addressed to us, but the route doesn't go out |
787 | * the source interface, pick an address on the source |
788 | * interface. This can happen when routing is asymmetric, or |
789 | * when the incoming packet was encapsulated |
790 | */ |
791 | if (sin == NULL && rcvif) { |
792 | KASSERT(ia == NULL); |
793 | s = pserialize_read_enter(); |
794 | IFADDR_READER_FOREACH(ifa, rcvif) { |
795 | if (ifa->ifa_addr->sa_family != AF_INET) |
796 | continue; |
797 | sin = &(ifatoia(ifa)->ia_addr); |
798 | ia = ifatoia(ifa); |
799 | ia4_acquire(ia, &psref_ia); |
800 | break; |
801 | } |
802 | pserialize_read_exit(s); |
803 | } |
804 | |
805 | m_put_rcvif_psref(rcvif, &psref); |
806 | |
807 | /* |
808 | * The following happens if the packet was not addressed to us, |
809 | * and was received on an interface with no IP address: |
810 | * We find the first AF_INET address on the first non-loopback |
811 | * interface. |
812 | */ |
813 | if (sin == NULL) { |
814 | KASSERT(ia == NULL); |
815 | s = pserialize_read_enter(); |
816 | IN_ADDRLIST_READER_FOREACH(ia) { |
817 | if (ia->ia_ifp->if_flags & IFF_LOOPBACK) |
818 | continue; |
819 | sin = &ia->ia_addr; |
820 | ia4_acquire(ia, &psref_ia); |
821 | break; |
822 | } |
823 | pserialize_read_exit(s); |
824 | } |
825 | |
826 | /* |
827 | * If we still didn't find an address, punt. We could have an |
828 | * interface up (and receiving packets) with no address. |
829 | */ |
830 | if (sin == NULL) { |
831 | KASSERT(ia == NULL); |
832 | m_freem(m); |
833 | goto done; |
834 | } |
835 | |
836 | ip->ip_src = sin->sin_addr; |
837 | ip->ip_ttl = MAXTTL; |
838 | |
839 | if (ia != NULL) |
840 | ia4_release(ia, &psref_ia); |
841 | |
842 | if (optlen > 0) { |
843 | u_char *cp; |
844 | int opt, cnt; |
845 | u_int len; |
846 | |
847 | /* |
848 | * Retrieve any source routing from the incoming packet; |
849 | * add on any record-route or timestamp options. |
850 | */ |
851 | cp = (u_char *) (ip + 1); |
852 | if ((opts = ip_srcroute()) == NULL && |
853 | (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { |
854 | MCLAIM(opts, m->m_owner); |
855 | opts->m_len = sizeof(struct in_addr); |
856 | *mtod(opts, struct in_addr *) = zeroin_addr; |
857 | } |
858 | if (opts) { |
859 | #ifdef ICMPPRINTFS |
860 | if (icmpprintfs) |
861 | printf("icmp_reflect optlen %d rt %d => " , |
862 | optlen, opts->m_len); |
863 | #endif |
864 | for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { |
865 | opt = cp[IPOPT_OPTVAL]; |
866 | if (opt == IPOPT_EOL) |
867 | break; |
868 | if (opt == IPOPT_NOP) |
869 | len = 1; |
870 | else { |
871 | if (cnt < IPOPT_OLEN + sizeof(*cp)) |
872 | break; |
873 | len = cp[IPOPT_OLEN]; |
874 | if (len < IPOPT_OLEN + sizeof(*cp) || |
875 | len > cnt) |
876 | break; |
877 | } |
878 | /* |
879 | * Should check for overflow, but it "can't happen" |
880 | */ |
881 | if (opt == IPOPT_RR || opt == IPOPT_TS || |
882 | opt == IPOPT_SECURITY) { |
883 | memmove(mtod(opts, char *) + opts->m_len, |
884 | cp, len); |
885 | opts->m_len += len; |
886 | } |
887 | } |
888 | /* Terminate & pad, if necessary */ |
889 | if ((cnt = opts->m_len % 4) != 0) { |
890 | for (; cnt < 4; cnt++) { |
891 | *(mtod(opts, char *) + opts->m_len) = |
892 | IPOPT_EOL; |
893 | opts->m_len++; |
894 | } |
895 | } |
896 | #ifdef ICMPPRINTFS |
897 | if (icmpprintfs) |
898 | printf("%d\n" , opts->m_len); |
899 | #endif |
900 | } |
901 | /* |
902 | * Now strip out original options by copying rest of first |
903 | * mbuf's data back, and adjust the IP length. |
904 | */ |
905 | ip->ip_len = htons(ntohs(ip->ip_len) - optlen); |
906 | ip->ip_hl = sizeof(struct ip) >> 2; |
907 | m->m_len -= optlen; |
908 | if (m->m_flags & M_PKTHDR) |
909 | m->m_pkthdr.len -= optlen; |
910 | optlen += sizeof(struct ip); |
911 | memmove(ip + 1, (char *)ip + optlen, |
912 | (unsigned)(m->m_len - sizeof(struct ip))); |
913 | } |
914 | m_tag_delete_nonpersistent(m); |
915 | m->m_flags &= ~(M_BCAST|M_MCAST); |
916 | |
917 | /* |
918 | * Clear any in-bound checksum flags for this packet. |
919 | */ |
920 | if (m->m_flags & M_PKTHDR) |
921 | m->m_pkthdr.csum_flags = 0; |
922 | |
923 | icmp_send(m, opts); |
924 | done: |
925 | curlwp_bindx(bound); |
926 | if (opts) |
927 | (void)m_free(opts); |
928 | } |
929 | |
930 | /* |
931 | * Send an icmp packet back to the ip level, |
932 | * after supplying a checksum. |
933 | */ |
934 | void |
935 | icmp_send(struct mbuf *m, struct mbuf *opts) |
936 | { |
937 | struct ip *ip = mtod(m, struct ip *); |
938 | int hlen; |
939 | struct icmp *icp; |
940 | |
941 | hlen = ip->ip_hl << 2; |
942 | m->m_data += hlen; |
943 | m->m_len -= hlen; |
944 | icp = mtod(m, struct icmp *); |
945 | icp->icmp_cksum = 0; |
946 | icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); |
947 | m->m_data -= hlen; |
948 | m->m_len += hlen; |
949 | #ifdef ICMPPRINTFS |
950 | if (icmpprintfs) { |
951 | char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; |
952 | printf("icmp_send to destination `%s' from `%s'\n" , |
953 | IN_PRINT(dbuf, &ip->ip_dst), IN_PRINT(sbuf, &ip->ip_src)); |
954 | } |
955 | #endif |
956 | (void)ip_output(m, opts, NULL, 0, NULL, NULL); |
957 | } |
958 | |
959 | n_time |
960 | iptime(void) |
961 | { |
962 | struct timeval atv; |
963 | u_long t; |
964 | |
965 | microtime(&atv); |
966 | t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; |
967 | return (htonl(t)); |
968 | } |
969 | |
970 | /* |
971 | * sysctl helper routine for net.inet.icmp.returndatabytes. ensures |
972 | * that the new value is in the correct range. |
973 | */ |
974 | static int |
975 | sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) |
976 | { |
977 | int error, t; |
978 | struct sysctlnode node; |
979 | |
980 | node = *rnode; |
981 | node.sysctl_data = &t; |
982 | t = icmpreturndatabytes; |
983 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
984 | if (error || newp == NULL) |
985 | return (error); |
986 | |
987 | if (t < 8 || t > 512) |
988 | return (EINVAL); |
989 | icmpreturndatabytes = t; |
990 | |
991 | return (0); |
992 | } |
993 | |
994 | /* |
995 | * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that |
996 | * the given value is not less than zero and then resets the timeout |
997 | * queue. |
998 | */ |
999 | static int |
1000 | sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) |
1001 | { |
1002 | int error, tmp; |
1003 | struct sysctlnode node; |
1004 | |
1005 | node = *rnode; |
1006 | node.sysctl_data = &tmp; |
1007 | tmp = icmp_redirtimeout; |
1008 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
1009 | if (error || newp == NULL) |
1010 | return (error); |
1011 | if (tmp < 0) |
1012 | return (EINVAL); |
1013 | icmp_redirtimeout = tmp; |
1014 | |
1015 | /* |
1016 | * was it a *defined* side-effect that anyone even *reading* |
1017 | * this value causes these things to happen? |
1018 | */ |
1019 | if (icmp_redirect_timeout_q != NULL) { |
1020 | if (icmp_redirtimeout == 0) { |
1021 | rt_timer_queue_destroy(icmp_redirect_timeout_q); |
1022 | icmp_redirect_timeout_q = NULL; |
1023 | } else { |
1024 | rt_timer_queue_change(icmp_redirect_timeout_q, |
1025 | icmp_redirtimeout); |
1026 | } |
1027 | } else if (icmp_redirtimeout > 0) { |
1028 | icmp_redirect_timeout_q = |
1029 | rt_timer_queue_create(icmp_redirtimeout); |
1030 | } |
1031 | |
1032 | return (0); |
1033 | } |
1034 | |
1035 | static int |
1036 | sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) |
1037 | { |
1038 | |
1039 | return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); |
1040 | } |
1041 | |
1042 | static void |
1043 | sysctl_netinet_icmp_setup(struct sysctllog **clog) |
1044 | { |
1045 | |
1046 | sysctl_createv(clog, 0, NULL, NULL, |
1047 | CTLFLAG_PERMANENT, |
1048 | CTLTYPE_NODE, "inet" , NULL, |
1049 | NULL, 0, NULL, 0, |
1050 | CTL_NET, PF_INET, CTL_EOL); |
1051 | sysctl_createv(clog, 0, NULL, NULL, |
1052 | CTLFLAG_PERMANENT, |
1053 | CTLTYPE_NODE, "icmp" , |
1054 | SYSCTL_DESCR("ICMPv4 related settings" ), |
1055 | NULL, 0, NULL, 0, |
1056 | CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL); |
1057 | |
1058 | sysctl_createv(clog, 0, NULL, NULL, |
1059 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
1060 | CTLTYPE_INT, "maskrepl" , |
1061 | SYSCTL_DESCR("Respond to ICMP_MASKREQ messages" ), |
1062 | NULL, 0, &icmpmaskrepl, 0, |
1063 | CTL_NET, PF_INET, IPPROTO_ICMP, |
1064 | ICMPCTL_MASKREPL, CTL_EOL); |
1065 | sysctl_createv(clog, 0, NULL, NULL, |
1066 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
1067 | CTLTYPE_INT, "returndatabytes" , |
1068 | SYSCTL_DESCR("Number of bytes to return in an ICMP " |
1069 | "error message" ), |
1070 | sysctl_net_inet_icmp_returndatabytes, 0, |
1071 | &icmpreturndatabytes, 0, |
1072 | CTL_NET, PF_INET, IPPROTO_ICMP, |
1073 | ICMPCTL_RETURNDATABYTES, CTL_EOL); |
1074 | sysctl_createv(clog, 0, NULL, NULL, |
1075 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
1076 | CTLTYPE_INT, "errppslimit" , |
1077 | SYSCTL_DESCR("Maximum number of outgoing ICMP error " |
1078 | "messages per second" ), |
1079 | NULL, 0, &icmperrppslim, 0, |
1080 | CTL_NET, PF_INET, IPPROTO_ICMP, |
1081 | ICMPCTL_ERRPPSLIMIT, CTL_EOL); |
1082 | sysctl_createv(clog, 0, NULL, NULL, |
1083 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
1084 | CTLTYPE_INT, "rediraccept" , |
1085 | SYSCTL_DESCR("Accept ICMP_REDIRECT messages" ), |
1086 | NULL, 0, &icmp_rediraccept, 0, |
1087 | CTL_NET, PF_INET, IPPROTO_ICMP, |
1088 | ICMPCTL_REDIRACCEPT, CTL_EOL); |
1089 | sysctl_createv(clog, 0, NULL, NULL, |
1090 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
1091 | CTLTYPE_INT, "redirtimeout" , |
1092 | SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated " |
1093 | "routes" ), |
1094 | sysctl_net_inet_icmp_redirtimeout, 0, |
1095 | &icmp_redirtimeout, 0, |
1096 | CTL_NET, PF_INET, IPPROTO_ICMP, |
1097 | ICMPCTL_REDIRTIMEOUT, CTL_EOL); |
1098 | sysctl_createv(clog, 0, NULL, NULL, |
1099 | CTLFLAG_PERMANENT, |
1100 | CTLTYPE_STRUCT, "stats" , |
1101 | SYSCTL_DESCR("ICMP statistics" ), |
1102 | sysctl_net_inet_icmp_stats, 0, NULL, 0, |
1103 | CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS, |
1104 | CTL_EOL); |
1105 | sysctl_createv(clog, 0, NULL, NULL, |
1106 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
1107 | CTLTYPE_INT, "bmcastecho" , |
1108 | SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP " |
1109 | "message to the broadcast or multicast" ), |
1110 | NULL, 0, &icmpbmcastecho, 0, |
1111 | CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO, |
1112 | CTL_EOL); |
1113 | } |
1114 | |
1115 | void |
1116 | icmp_statinc(u_int stat) |
1117 | { |
1118 | |
1119 | KASSERT(stat < ICMP_NSTATS); |
1120 | ICMP_STATINC(stat); |
1121 | } |
1122 | |
1123 | /* Table of common MTUs: */ |
1124 | |
1125 | static const u_int mtu_table[] = { |
1126 | 65535, 65280, 32000, 17914, 9180, 8166, |
1127 | 4352, 2002, 1492, 1006, 508, 296, 68, 0 |
1128 | }; |
1129 | |
1130 | void |
1131 | icmp_mtudisc(struct icmp *icp, struct in_addr faddr) |
1132 | { |
1133 | struct icmp_mtudisc_callback *mc; |
1134 | struct sockaddr *dst = sintosa(&icmpsrc); |
1135 | struct rtentry *rt; |
1136 | u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */ |
1137 | int error; |
1138 | |
1139 | rt = rtalloc1(dst, 1); |
1140 | if (rt == NULL) |
1141 | return; |
1142 | |
1143 | /* If we didn't get a host route, allocate one */ |
1144 | |
1145 | if ((rt->rt_flags & RTF_HOST) == 0) { |
1146 | struct rtentry *nrt; |
1147 | |
1148 | error = rtrequest(RTM_ADD, dst, rt->rt_gateway, NULL, |
1149 | RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); |
1150 | if (error) { |
1151 | rtfree(rt); |
1152 | return; |
1153 | } |
1154 | nrt->rt_rmx = rt->rt_rmx; |
1155 | rtfree(rt); |
1156 | rt = nrt; |
1157 | } |
1158 | error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q); |
1159 | if (error) { |
1160 | rtfree(rt); |
1161 | return; |
1162 | } |
1163 | |
1164 | if (mtu == 0) { |
1165 | int i = 0; |
1166 | |
1167 | mtu = ntohs(icp->icmp_ip.ip_len); |
1168 | /* Some 4.2BSD-based routers incorrectly adjust the ip_len */ |
1169 | if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0) |
1170 | mtu -= (icp->icmp_ip.ip_hl << 2); |
1171 | |
1172 | /* If we still can't guess a value, try the route */ |
1173 | |
1174 | if (mtu == 0) { |
1175 | mtu = rt->rt_rmx.rmx_mtu; |
1176 | |
1177 | /* If no route mtu, default to the interface mtu */ |
1178 | |
1179 | if (mtu == 0) |
1180 | mtu = rt->rt_ifp->if_mtu; |
1181 | } |
1182 | |
1183 | for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++) |
1184 | if (mtu > mtu_table[i]) { |
1185 | mtu = mtu_table[i]; |
1186 | break; |
1187 | } |
1188 | } |
1189 | |
1190 | /* |
1191 | * XXX: RTV_MTU is overloaded, since the admin can set it |
1192 | * to turn off PMTU for a route, and the kernel can |
1193 | * set it to indicate a serious problem with PMTU |
1194 | * on a route. We should be using a separate flag |
1195 | * for the kernel to indicate this. |
1196 | */ |
1197 | |
1198 | if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { |
1199 | if (mtu < 296 || mtu > rt->rt_ifp->if_mtu) |
1200 | rt->rt_rmx.rmx_locks |= RTV_MTU; |
1201 | else if (rt->rt_rmx.rmx_mtu > mtu || |
1202 | rt->rt_rmx.rmx_mtu == 0) { |
1203 | ICMP_STATINC(ICMP_STAT_PMTUCHG); |
1204 | rt->rt_rmx.rmx_mtu = mtu; |
1205 | } |
1206 | } |
1207 | |
1208 | if (rt) |
1209 | rtfree(rt); |
1210 | |
1211 | /* |
1212 | * Notify protocols that the MTU for this destination |
1213 | * has changed. |
1214 | */ |
1215 | for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; |
1216 | mc = LIST_NEXT(mc, mc_list)) |
1217 | (*mc->mc_func)(faddr); |
1218 | } |
1219 | |
1220 | /* |
1221 | * Return the next larger or smaller MTU plateau (table from RFC 1191) |
1222 | * given current value MTU. If DIR is less than zero, a larger plateau |
1223 | * is returned; otherwise, a smaller value is returned. |
1224 | */ |
1225 | u_int |
1226 | ip_next_mtu(u_int mtu, int dir) /* XXX */ |
1227 | { |
1228 | int i; |
1229 | |
1230 | for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) { |
1231 | if (mtu >= mtu_table[i]) |
1232 | break; |
1233 | } |
1234 | |
1235 | if (dir < 0) { |
1236 | if (i == 0) { |
1237 | return 0; |
1238 | } else { |
1239 | return mtu_table[i - 1]; |
1240 | } |
1241 | } else { |
1242 | if (mtu_table[i] == 0) { |
1243 | return 0; |
1244 | } else if (mtu > mtu_table[i]) { |
1245 | return mtu_table[i]; |
1246 | } else { |
1247 | return mtu_table[i + 1]; |
1248 | } |
1249 | } |
1250 | } |
1251 | |
1252 | static void |
1253 | icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) |
1254 | { |
1255 | |
1256 | KASSERT(rt != NULL); |
1257 | rt_assert_referenced(rt); |
1258 | |
1259 | if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == |
1260 | (RTF_DYNAMIC | RTF_HOST)) { |
1261 | rtrequest(RTM_DELETE, rt_getkey(rt), |
1262 | rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); |
1263 | } else { |
1264 | if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { |
1265 | rt->rt_rmx.rmx_mtu = 0; |
1266 | } |
1267 | } |
1268 | } |
1269 | |
1270 | static void |
1271 | icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r) |
1272 | { |
1273 | |
1274 | KASSERT(rt != NULL); |
1275 | rt_assert_referenced(rt); |
1276 | |
1277 | if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == |
1278 | (RTF_DYNAMIC | RTF_HOST)) { |
1279 | rtrequest(RTM_DELETE, rt_getkey(rt), |
1280 | rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); |
1281 | } |
1282 | } |
1283 | |
1284 | /* |
1285 | * Perform rate limit check. |
1286 | * Returns 0 if it is okay to send the icmp packet. |
1287 | * Returns 1 if the router SHOULD NOT send this icmp packet due to rate |
1288 | * limitation. |
1289 | * |
1290 | * XXX per-destination/type check necessary? |
1291 | */ |
1292 | int |
1293 | icmp_ratelimit(const struct in_addr *dst, const int type, |
1294 | const int code) |
1295 | { |
1296 | |
1297 | /* PPS limit */ |
1298 | if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count, |
1299 | icmperrppslim)) { |
1300 | /* The packet is subject to rate limit */ |
1301 | return 1; |
1302 | } |
1303 | |
1304 | /* okay to send */ |
1305 | return 0; |
1306 | } |
1307 | |