1 /* $NetBSD: ip_icmp.c,v 1.151 2016/08/01 03:15:30 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 1.151 2016/08/01 03:15:30 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 ia4_acquire(ifatoia(ifa), &psref_ia); 799 break; 800 } 801 pserialize_read_exit(s); 802 } 803 804 m_put_rcvif_psref(rcvif, &psref); 805 806 /* 807 * The following happens if the packet was not addressed to us, 808 * and was received on an interface with no IP address: 809 * We find the first AF_INET address on the first non-loopback 810 * interface. 811 */ 812 if (sin == NULL) { 813 KASSERT(ia == NULL); 814 s = pserialize_read_enter(); 815 IN_ADDRLIST_READER_FOREACH(ia) { 816 if (ia->ia_ifp->if_flags & IFF_LOOPBACK) 817 continue; 818 sin = &ia->ia_addr; 819 ia4_acquire(ia, &psref_ia); 820 break; 821 } 822 pserialize_read_exit(s); 823 } 824 825 /* 826 * If we still didn't find an address, punt. We could have an 827 * interface up (and receiving packets) with no address. 828 */ 829 if (sin == NULL) { 830 KASSERT(ia == NULL); 831 m_freem(m); 832 goto done; 833 } 834 835 ip->ip_src = sin->sin_addr; 836 ip->ip_ttl = MAXTTL; 837 838 if (ia != NULL) 839 ia4_release(ia, &psref_ia); 840 841 if (optlen > 0) { 842 u_char *cp; 843 int opt, cnt; 844 u_int len; 845 846 /* 847 * Retrieve any source routing from the incoming packet; 848 * add on any record-route or timestamp options. 849 */ 850 cp = (u_char *) (ip + 1); 851 if ((opts = ip_srcroute()) == NULL && 852 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { 853 MCLAIM(opts, m->m_owner); 854 opts->m_len = sizeof(struct in_addr); 855 *mtod(opts, struct in_addr *) = zeroin_addr; 856 } 857 if (opts) { 858 #ifdef ICMPPRINTFS 859 if (icmpprintfs) 860 printf("icmp_reflect optlen %d rt %d => ", 861 optlen, opts->m_len); 862 #endif 863 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 864 opt = cp[IPOPT_OPTVAL]; 865 if (opt == IPOPT_EOL) 866 break; 867 if (opt == IPOPT_NOP) 868 len = 1; 869 else { 870 if (cnt < IPOPT_OLEN + sizeof(*cp)) 871 break; 872 len = cp[IPOPT_OLEN]; 873 if (len < IPOPT_OLEN + sizeof(*cp) || 874 len > cnt) 875 break; 876 } 877 /* 878 * Should check for overflow, but it "can't happen" 879 */ 880 if (opt == IPOPT_RR || opt == IPOPT_TS || 881 opt == IPOPT_SECURITY) { 882 memmove(mtod(opts, char *) + opts->m_len, 883 cp, len); 884 opts->m_len += len; 885 } 886 } 887 /* Terminate & pad, if necessary */ 888 if ((cnt = opts->m_len % 4) != 0) { 889 for (; cnt < 4; cnt++) { 890 *(mtod(opts, char *) + opts->m_len) = 891 IPOPT_EOL; 892 opts->m_len++; 893 } 894 } 895 #ifdef ICMPPRINTFS 896 if (icmpprintfs) 897 printf("%d\n", opts->m_len); 898 #endif 899 } 900 /* 901 * Now strip out original options by copying rest of first 902 * mbuf's data back, and adjust the IP length. 903 */ 904 ip->ip_len = htons(ntohs(ip->ip_len) - optlen); 905 ip->ip_hl = sizeof(struct ip) >> 2; 906 m->m_len -= optlen; 907 if (m->m_flags & M_PKTHDR) 908 m->m_pkthdr.len -= optlen; 909 optlen += sizeof(struct ip); 910 memmove(ip + 1, (char *)ip + optlen, 911 (unsigned)(m->m_len - sizeof(struct ip))); 912 } 913 m_tag_delete_nonpersistent(m); 914 m->m_flags &= ~(M_BCAST|M_MCAST); 915 916 /* 917 * Clear any in-bound checksum flags for this packet. 918 */ 919 if (m->m_flags & M_PKTHDR) 920 m->m_pkthdr.csum_flags = 0; 921 922 icmp_send(m, opts); 923 done: 924 curlwp_bindx(bound); 925 if (opts) 926 (void)m_free(opts); 927 } 928 929 /* 930 * Send an icmp packet back to the ip level, 931 * after supplying a checksum. 932 */ 933 void 934 icmp_send(struct mbuf *m, struct mbuf *opts) 935 { 936 struct ip *ip = mtod(m, struct ip *); 937 int hlen; 938 struct icmp *icp; 939 940 hlen = ip->ip_hl << 2; 941 m->m_data += hlen; 942 m->m_len -= hlen; 943 icp = mtod(m, struct icmp *); 944 icp->icmp_cksum = 0; 945 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 946 m->m_data -= hlen; 947 m->m_len += hlen; 948 #ifdef ICMPPRINTFS 949 if (icmpprintfs) { 950 char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; 951 printf("icmp_send to destination `%s' from `%s'\n", 952 IN_PRINT(dbuf, &ip->ip_dst), IN_PRINT(sbuf, &ip->ip_src)); 953 } 954 #endif 955 (void)ip_output(m, opts, NULL, 0, NULL, NULL); 956 } 957 958 n_time 959 iptime(void) 960 { 961 struct timeval atv; 962 u_long t; 963 964 microtime(&atv); 965 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 966 return (htonl(t)); 967 } 968 969 /* 970 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures 971 * that the new value is in the correct range. 972 */ 973 static int 974 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) 975 { 976 int error, t; 977 struct sysctlnode node; 978 979 node = *rnode; 980 node.sysctl_data = &t; 981 t = icmpreturndatabytes; 982 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 983 if (error || newp == NULL) 984 return (error); 985 986 if (t < 8 || t > 512) 987 return (EINVAL); 988 icmpreturndatabytes = t; 989 990 return (0); 991 } 992 993 /* 994 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that 995 * the given value is not less than zero and then resets the timeout 996 * queue. 997 */ 998 static int 999 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) 1000 { 1001 int error, tmp; 1002 struct sysctlnode node; 1003 1004 node = *rnode; 1005 node.sysctl_data = &tmp; 1006 tmp = icmp_redirtimeout; 1007 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1008 if (error || newp == NULL) 1009 return (error); 1010 if (tmp < 0) 1011 return (EINVAL); 1012 icmp_redirtimeout = tmp; 1013 1014 /* 1015 * was it a *defined* side-effect that anyone even *reading* 1016 * this value causes these things to happen? 1017 */ 1018 if (icmp_redirect_timeout_q != NULL) { 1019 if (icmp_redirtimeout == 0) { 1020 rt_timer_queue_destroy(icmp_redirect_timeout_q, 1021 true); 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