1 /* $NetBSD: ip_icmp.c,v 1.124 2010/07/02 07:02:00 kefren 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 1.124 2010/07/02 07:02:00 kefren Exp $"); 98 99 #include "opt_ipsec.h" 100 101 #include <sys/param.h> 102 #include <sys/systm.h> 103 #include <sys/malloc.h> 104 #include <sys/mbuf.h> 105 #include <sys/protosw.h> 106 #include <sys/socket.h> 107 #include <sys/time.h> 108 #include <sys/kernel.h> 109 #include <sys/syslog.h> 110 #include <sys/sysctl.h> 111 112 #include <net/if.h> 113 #include <net/route.h> 114 115 #include <netinet/in.h> 116 #include <netinet/in_systm.h> 117 #include <netinet/in_var.h> 118 #include <netinet/ip.h> 119 #include <netinet/ip_icmp.h> 120 #include <netinet/ip_var.h> 121 #include <netinet/in_pcb.h> 122 #include <netinet/in_proto.h> 123 #include <netinet/icmp_var.h> 124 #include <netinet/icmp_private.h> 125 126 #ifdef IPSEC 127 #include <netinet6/ipsec.h> 128 #include <netkey/key.h> 129 #endif 130 131 #ifdef FAST_IPSEC 132 #include <netipsec/ipsec.h> 133 #include <netipsec/key.h> 134 #endif /* FAST_IPSEC*/ 135 136 #include <machine/stdarg.h> 137 138 /* 139 * ICMP routines: error generation, receive packet processing, and 140 * routines to turnaround packets back to the originator, and 141 * host table maintenance routines. 142 */ 143 144 int icmpmaskrepl = 0; 145 int icmpbmcastecho = 0; 146 #ifdef ICMPPRINTFS 147 int icmpprintfs = 0; 148 #endif 149 int icmpreturndatabytes = 8; 150 151 percpu_t *icmpstat_percpu; 152 153 /* 154 * List of callbacks to notify when Path MTU changes are made. 155 */ 156 struct icmp_mtudisc_callback { 157 LIST_ENTRY(icmp_mtudisc_callback) mc_list; 158 void (*mc_func)(struct in_addr); 159 }; 160 161 LIST_HEAD(, icmp_mtudisc_callback) icmp_mtudisc_callbacks = 162 LIST_HEAD_INITIALIZER(&icmp_mtudisc_callbacks); 163 164 #if 0 165 static u_int ip_next_mtu(u_int, int); 166 #else 167 /*static*/ u_int ip_next_mtu(u_int, int); 168 #endif 169 170 extern int icmperrppslim; 171 static int icmperrpps_count = 0; 172 static struct timeval icmperrppslim_last; 173 static int icmp_rediraccept = 1; 174 static int icmp_redirtimeout = 600; 175 static struct rttimer_queue *icmp_redirect_timeout_q = NULL; 176 177 static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *); 178 static void icmp_redirect_timeout(struct rtentry *, struct rttimer *); 179 180 static void sysctl_netinet_icmp_setup(struct sysctllog **); 181 182 void 183 icmp_init(void) 184 { 185 186 sysctl_netinet_icmp_setup(NULL); 187 188 /* 189 * This is only useful if the user initializes redirtimeout to 190 * something other than zero. 191 */ 192 if (icmp_redirtimeout != 0) { 193 icmp_redirect_timeout_q = 194 rt_timer_queue_create(icmp_redirtimeout); 195 } 196 197 icmpstat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP_NSTATS); 198 } 199 200 /* 201 * Register a Path MTU Discovery callback. 202 */ 203 void 204 icmp_mtudisc_callback_register(void (*func)(struct in_addr)) 205 { 206 struct icmp_mtudisc_callback *mc; 207 208 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 209 mc = LIST_NEXT(mc, mc_list)) { 210 if (mc->mc_func == func) 211 return; 212 } 213 214 mc = malloc(sizeof(*mc), M_PCB, M_NOWAIT); 215 if (mc == NULL) 216 panic("icmp_mtudisc_callback_register"); 217 218 mc->mc_func = func; 219 LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, mc, mc_list); 220 } 221 222 /* 223 * Generate an error packet of type error 224 * in response to bad packet ip. 225 */ 226 void 227 icmp_error(struct mbuf *n, int type, int code, n_long dest, 228 int destmtu) 229 { 230 struct ip *oip = mtod(n, struct ip *), *nip; 231 unsigned oiplen = oip->ip_hl << 2; 232 struct icmp *icp; 233 struct mbuf *m; 234 struct m_tag *mtag; 235 unsigned icmplen, mblen; 236 237 #ifdef ICMPPRINTFS 238 if (icmpprintfs) 239 printf("icmp_error(%p, type:%d, code:%d)\n", oip, type, code); 240 #endif 241 if (type != ICMP_REDIRECT) 242 ICMP_STATINC(ICMP_STAT_ERROR); 243 /* 244 * Don't send error if the original packet was encrypted. 245 * Don't send error if not the first fragment of message. 246 * Don't error if the old packet protocol was ICMP 247 * error message, only known informational types. 248 */ 249 if (n->m_flags & M_DECRYPTED) 250 goto freeit; 251 if (oip->ip_off &~ htons(IP_MF|IP_DF)) 252 goto freeit; 253 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 254 n->m_len >= oiplen + ICMP_MINLEN && 255 !ICMP_INFOTYPE(((struct icmp *)((char *)oip + oiplen))->icmp_type)) { 256 ICMP_STATINC(ICMP_STAT_OLDICMP); 257 goto freeit; 258 } 259 /* Don't send error in response to a multicast or broadcast packet */ 260 if (n->m_flags & (M_BCAST|M_MCAST)) 261 goto freeit; 262 263 /* 264 * First, do a rate limitation check. 265 */ 266 if (icmp_ratelimit(&oip->ip_src, type, code)) { 267 /* XXX stat */ 268 goto freeit; 269 } 270 271 /* 272 * Now, formulate icmp message 273 */ 274 icmplen = oiplen + min(icmpreturndatabytes, 275 ntohs(oip->ip_len) - oiplen); 276 /* 277 * Defend against mbuf chains shorter than oip->ip_len - oiplen: 278 */ 279 mblen = 0; 280 for (m = n; m && (mblen < icmplen); m = m->m_next) 281 mblen += m->m_len; 282 icmplen = min(mblen, icmplen); 283 284 /* 285 * As we are not required to return everything we have, 286 * we return whatever we can return at ease. 287 * 288 * Note that ICMP datagrams longer than 576 octets are out of spec 289 * according to RFC1812; the limit on icmpreturndatabytes below in 290 * icmp_sysctl will keep things below that limit. 291 */ 292 293 KASSERT(ICMP_MINLEN <= MCLBYTES); 294 295 if (icmplen + ICMP_MINLEN > MCLBYTES) 296 icmplen = MCLBYTES - ICMP_MINLEN; 297 298 m = m_gethdr(M_DONTWAIT, MT_HEADER); 299 if (m && (icmplen + ICMP_MINLEN > MHLEN)) { 300 MCLGET(m, M_DONTWAIT); 301 if ((m->m_flags & M_EXT) == 0) { 302 m_freem(m); 303 m = NULL; 304 } 305 } 306 if (m == NULL) 307 goto freeit; 308 MCLAIM(m, n->m_owner); 309 m->m_len = icmplen + ICMP_MINLEN; 310 if ((m->m_flags & M_EXT) == 0) 311 MH_ALIGN(m, m->m_len); 312 else { 313 m->m_data += sizeof(struct ip); 314 m->m_len -= sizeof(struct ip); 315 } 316 icp = mtod(m, struct icmp *); 317 if ((u_int)type > ICMP_MAXTYPE) 318 panic("icmp_error"); 319 ICMP_STATINC(ICMP_STAT_OUTHIST + type); 320 icp->icmp_type = type; 321 if (type == ICMP_REDIRECT) 322 icp->icmp_gwaddr.s_addr = dest; 323 else { 324 icp->icmp_void = 0; 325 /* 326 * The following assignments assume an overlay with the 327 * zeroed icmp_void field. 328 */ 329 if (type == ICMP_PARAMPROB) { 330 icp->icmp_pptr = code; 331 code = 0; 332 } else if (type == ICMP_UNREACH && 333 code == ICMP_UNREACH_NEEDFRAG && destmtu) 334 icp->icmp_nextmtu = htons(destmtu); 335 } 336 337 icp->icmp_code = code; 338 m_copydata(n, 0, icmplen, (void *)&icp->icmp_ip); 339 340 /* 341 * Now, copy old ip header (without options) 342 * in front of icmp message. 343 */ 344 if ((m->m_flags & M_EXT) == 0 && 345 m->m_data - sizeof(struct ip) < m->m_pktdat) 346 panic("icmp len"); 347 m->m_data -= sizeof(struct ip); 348 m->m_len += sizeof(struct ip); 349 m->m_pkthdr.len = m->m_len; 350 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif; 351 nip = mtod(m, struct ip *); 352 /* ip_v set in ip_output */ 353 nip->ip_hl = sizeof(struct ip) >> 2; 354 nip->ip_tos = 0; 355 nip->ip_len = htons(m->m_len); 356 /* ip_id set in ip_output */ 357 nip->ip_off = htons(0); 358 /* ip_ttl set in icmp_reflect */ 359 nip->ip_p = IPPROTO_ICMP; 360 nip->ip_src = oip->ip_src; 361 nip->ip_dst = oip->ip_dst; 362 /* move PF m_tag to new packet, if it exists */ 363 mtag = m_tag_find(n, PACKET_TAG_PF, NULL); 364 if (mtag != NULL) { 365 m_tag_unlink(n, mtag); 366 m_tag_prepend(m, mtag); 367 } 368 icmp_reflect(m); 369 370 freeit: 371 m_freem(n); 372 } 373 374 struct sockaddr_in icmpsrc = { 375 .sin_len = sizeof (struct sockaddr_in), 376 .sin_family = AF_INET, 377 }; 378 static struct sockaddr_in icmpdst = { 379 .sin_len = sizeof (struct sockaddr_in), 380 .sin_family = AF_INET, 381 }; 382 static struct sockaddr_in icmpgw = { 383 .sin_len = sizeof (struct sockaddr_in), 384 .sin_family = AF_INET, 385 }; 386 struct sockaddr_in icmpmask = { 387 .sin_len = 8, 388 .sin_family = 0, 389 }; 390 391 /* 392 * Process a received ICMP message. 393 */ 394 void 395 icmp_input(struct mbuf *m, ...) 396 { 397 int proto; 398 struct icmp *icp; 399 struct ip *ip = mtod(m, struct ip *); 400 int icmplen; 401 int i; 402 struct in_ifaddr *ia; 403 void *(*ctlfunc)(int, const struct sockaddr *, void *); 404 int code; 405 int hlen; 406 va_list ap; 407 struct rtentry *rt; 408 409 va_start(ap, m); 410 hlen = va_arg(ap, int); 411 proto = va_arg(ap, int); 412 va_end(ap); 413 414 /* 415 * Locate icmp structure in mbuf, and check 416 * that not corrupted and of at least minimum length. 417 */ 418 icmplen = ntohs(ip->ip_len) - hlen; 419 #ifdef ICMPPRINTFS 420 if (icmpprintfs) { 421 printf("icmp_input from `%s' to ", inet_ntoa(ip->ip_src)); 422 printf("`%s', len %d\n", inet_ntoa(ip->ip_dst), icmplen); 423 } 424 #endif 425 if (icmplen < ICMP_MINLEN) { 426 ICMP_STATINC(ICMP_STAT_TOOSHORT); 427 goto freeit; 428 } 429 i = hlen + min(icmplen, ICMP_ADVLENMIN); 430 if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == 0) { 431 ICMP_STATINC(ICMP_STAT_TOOSHORT); 432 return; 433 } 434 ip = mtod(m, struct ip *); 435 m->m_len -= hlen; 436 m->m_data += hlen; 437 icp = mtod(m, struct icmp *); 438 /* Don't need to assert alignment, here. */ 439 if (in_cksum(m, icmplen)) { 440 ICMP_STATINC(ICMP_STAT_CHECKSUM); 441 goto freeit; 442 } 443 m->m_len += hlen; 444 m->m_data -= hlen; 445 446 #ifdef ICMPPRINTFS 447 /* 448 * Message type specific processing. 449 */ 450 if (icmpprintfs) 451 printf("icmp_input(type:%d, code:%d)\n", icp->icmp_type, 452 icp->icmp_code); 453 #endif 454 if (icp->icmp_type > ICMP_MAXTYPE) 455 goto raw; 456 ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type); 457 code = icp->icmp_code; 458 switch (icp->icmp_type) { 459 460 case ICMP_UNREACH: 461 switch (code) { 462 case ICMP_UNREACH_NET: 463 code = PRC_UNREACH_NET; 464 break; 465 466 case ICMP_UNREACH_HOST: 467 code = PRC_UNREACH_HOST; 468 break; 469 470 case ICMP_UNREACH_PROTOCOL: 471 code = PRC_UNREACH_PROTOCOL; 472 break; 473 474 case ICMP_UNREACH_PORT: 475 code = PRC_UNREACH_PORT; 476 break; 477 478 case ICMP_UNREACH_SRCFAIL: 479 code = PRC_UNREACH_SRCFAIL; 480 break; 481 482 case ICMP_UNREACH_NEEDFRAG: 483 code = PRC_MSGSIZE; 484 break; 485 486 case ICMP_UNREACH_NET_UNKNOWN: 487 case ICMP_UNREACH_NET_PROHIB: 488 case ICMP_UNREACH_TOSNET: 489 code = PRC_UNREACH_NET; 490 break; 491 492 case ICMP_UNREACH_HOST_UNKNOWN: 493 case ICMP_UNREACH_ISOLATED: 494 case ICMP_UNREACH_HOST_PROHIB: 495 case ICMP_UNREACH_TOSHOST: 496 code = PRC_UNREACH_HOST; 497 break; 498 499 default: 500 goto badcode; 501 } 502 goto deliver; 503 504 case ICMP_TIMXCEED: 505 if (code > 1) 506 goto badcode; 507 code += PRC_TIMXCEED_INTRANS; 508 goto deliver; 509 510 case ICMP_PARAMPROB: 511 if (code > 1) 512 goto badcode; 513 code = PRC_PARAMPROB; 514 goto deliver; 515 516 case ICMP_SOURCEQUENCH: 517 if (code) 518 goto badcode; 519 code = PRC_QUENCH; 520 goto deliver; 521 522 deliver: 523 /* 524 * Problem with datagram; advise higher level routines. 525 */ 526 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 527 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 528 ICMP_STATINC(ICMP_STAT_BADLEN); 529 goto freeit; 530 } 531 if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) 532 goto badcode; 533 #ifdef ICMPPRINTFS 534 if (icmpprintfs) 535 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 536 #endif 537 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 538 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; 539 if (ctlfunc) 540 (void) (*ctlfunc)(code, sintosa(&icmpsrc), 541 &icp->icmp_ip); 542 break; 543 544 badcode: 545 ICMP_STATINC(ICMP_STAT_BADCODE); 546 break; 547 548 case ICMP_ECHO: 549 if (!icmpbmcastecho && 550 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 551 ICMP_STATINC(ICMP_STAT_BMCASTECHO); 552 break; 553 } 554 icp->icmp_type = ICMP_ECHOREPLY; 555 goto reflect; 556 557 case ICMP_TSTAMP: 558 if (icmplen < ICMP_TSLEN) { 559 ICMP_STATINC(ICMP_STAT_BADLEN); 560 break; 561 } 562 if (!icmpbmcastecho && 563 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 564 ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); 565 break; 566 } 567 icp->icmp_type = ICMP_TSTAMPREPLY; 568 icp->icmp_rtime = iptime(); 569 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 570 goto reflect; 571 572 case ICMP_MASKREQ: 573 if (icmpmaskrepl == 0) 574 break; 575 /* 576 * We are not able to respond with all ones broadcast 577 * unless we receive it over a point-to-point interface. 578 */ 579 if (icmplen < ICMP_MASKLEN) { 580 ICMP_STATINC(ICMP_STAT_BADLEN); 581 break; 582 } 583 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 584 in_nullhost(ip->ip_dst)) 585 icmpdst.sin_addr = ip->ip_src; 586 else 587 icmpdst.sin_addr = ip->ip_dst; 588 ia = ifatoia(ifaof_ifpforaddr(sintosa(&icmpdst), 589 m->m_pkthdr.rcvif)); 590 if (ia == 0) 591 break; 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 reflect: 601 { 602 uint64_t *icps = percpu_getref(icmpstat_percpu); 603 icps[ICMP_STAT_REFLECT]++; 604 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; 605 percpu_putref(icmpstat_percpu); 606 } 607 icmp_reflect(m); 608 return; 609 610 case ICMP_REDIRECT: 611 if (code > 3) 612 goto badcode; 613 if (icmp_rediraccept == 0) 614 goto freeit; 615 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 616 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 617 ICMP_STATINC(ICMP_STAT_BADLEN); 618 break; 619 } 620 /* 621 * Short circuit routing redirects to force 622 * immediate change in the kernel's routing 623 * tables. The message is also handed to anyone 624 * listening on a raw socket (e.g. the routing 625 * daemon for use in updating its tables). 626 */ 627 icmpgw.sin_addr = ip->ip_src; 628 icmpdst.sin_addr = icp->icmp_gwaddr; 629 #ifdef ICMPPRINTFS 630 if (icmpprintfs) { 631 printf("redirect dst `%s' to `%s'\n", 632 inet_ntoa(icp->icmp_ip.ip_dst), 633 inet_ntoa(icp->icmp_gwaddr)); 634 } 635 #endif 636 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 637 rt = NULL; 638 rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst), 639 NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt); 640 if (rt != NULL && icmp_redirtimeout != 0) { 641 i = rt_timer_add(rt, icmp_redirect_timeout, 642 icmp_redirect_timeout_q); 643 if (i) 644 log(LOG_ERR, "ICMP: redirect failed to " 645 "register timeout for route to %x, " 646 "code %d\n", 647 icp->icmp_ip.ip_dst.s_addr, i); 648 } 649 if (rt != NULL) 650 rtfree(rt); 651 652 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); 653 #if defined(IPSEC) || defined(FAST_IPSEC) 654 key_sa_routechange((struct sockaddr *)&icmpsrc); 655 #endif 656 break; 657 658 /* 659 * No kernel processing for the following; 660 * just fall through to send to raw listener. 661 */ 662 case ICMP_ECHOREPLY: 663 case ICMP_ROUTERADVERT: 664 case ICMP_ROUTERSOLICIT: 665 case ICMP_TSTAMPREPLY: 666 case ICMP_IREQREPLY: 667 case ICMP_MASKREPLY: 668 default: 669 break; 670 } 671 672 raw: 673 rip_input(m, hlen, proto); 674 return; 675 676 freeit: 677 m_freem(m); 678 return; 679 } 680 681 /* 682 * Reflect the ip packet back to the source 683 */ 684 void 685 icmp_reflect(struct mbuf *m) 686 { 687 struct ip *ip = mtod(m, struct ip *); 688 struct in_ifaddr *ia; 689 struct ifaddr *ifa; 690 struct sockaddr_in *sin = 0; 691 struct in_addr t; 692 struct mbuf *opts = 0; 693 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 694 695 if (!in_canforward(ip->ip_src) && 696 ((ip->ip_src.s_addr & IN_CLASSA_NET) != 697 htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { 698 m_freem(m); /* Bad return address */ 699 goto done; /* ip_output() will check for broadcast */ 700 } 701 t = ip->ip_dst; 702 ip->ip_dst = ip->ip_src; 703 /* 704 * If the incoming packet was addressed directly to us, use 705 * dst as the src for the reply. Otherwise (broadcast or 706 * anonymous), use an address which corresponds to the 707 * incoming interface, with a preference for the address which 708 * corresponds to the route to the destination of the ICMP. 709 */ 710 711 /* Look for packet addressed to us */ 712 INADDR_TO_IA(t, ia); 713 714 /* look for packet sent to broadcast address */ 715 if (ia == NULL && m->m_pkthdr.rcvif && 716 (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST)) { 717 IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) { 718 if (ifa->ifa_addr->sa_family != AF_INET) 719 continue; 720 if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) { 721 ia = ifatoia(ifa); 722 break; 723 } 724 } 725 } 726 727 if (ia) 728 sin = &ia->ia_addr; 729 730 icmpdst.sin_addr = t; 731 732 /* 733 * if the packet is addressed somewhere else, compute the 734 * source address for packets routed back to the source, and 735 * use that, if it's an address on the interface which 736 * received the packet 737 */ 738 if (sin == NULL && m->m_pkthdr.rcvif) { 739 struct sockaddr_in sin_dst; 740 struct route icmproute; 741 int errornum; 742 743 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); 744 memset(&icmproute, 0, sizeof(icmproute)); 745 errornum = 0; 746 sin = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum); 747 /* errornum is never used */ 748 rtcache_free(&icmproute); 749 /* check to make sure sin is a source address on rcvif */ 750 if (sin) { 751 t = sin->sin_addr; 752 sin = NULL; 753 INADDR_TO_IA(t, ia); 754 while (ia) { 755 if (ia->ia_ifp == m->m_pkthdr.rcvif) { 756 sin = &ia->ia_addr; 757 break; 758 } 759 NEXT_IA_WITH_SAME_ADDR(ia); 760 } 761 } 762 } 763 764 /* 765 * if it was not addressed to us, but the route doesn't go out 766 * the source interface, pick an address on the source 767 * interface. This can happen when routing is asymmetric, or 768 * when the incoming packet was encapsulated 769 */ 770 if (sin == NULL && m->m_pkthdr.rcvif) { 771 IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) { 772 if (ifa->ifa_addr->sa_family != AF_INET) 773 continue; 774 sin = &(ifatoia(ifa)->ia_addr); 775 break; 776 } 777 } 778 779 /* 780 * The following happens if the packet was not addressed to us, 781 * and was received on an interface with no IP address: 782 * We find the first AF_INET address on the first non-loopback 783 * interface. 784 */ 785 if (sin == NULL) 786 TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) { 787 if (ia->ia_ifp->if_flags & IFF_LOOPBACK) 788 continue; 789 sin = &ia->ia_addr; 790 break; 791 } 792 793 /* 794 * If we still didn't find an address, punt. We could have an 795 * interface up (and receiving packets) with no address. 796 */ 797 if (sin == NULL) { 798 m_freem(m); 799 goto done; 800 } 801 802 ip->ip_src = sin->sin_addr; 803 ip->ip_ttl = MAXTTL; 804 805 if (optlen > 0) { 806 u_char *cp; 807 int opt, cnt; 808 u_int len; 809 810 /* 811 * Retrieve any source routing from the incoming packet; 812 * add on any record-route or timestamp options. 813 */ 814 cp = (u_char *) (ip + 1); 815 if ((opts = ip_srcroute()) == 0 && 816 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { 817 MCLAIM(opts, m->m_owner); 818 opts->m_len = sizeof(struct in_addr); 819 *mtod(opts, struct in_addr *) = zeroin_addr; 820 } 821 if (opts) { 822 #ifdef ICMPPRINTFS 823 if (icmpprintfs) 824 printf("icmp_reflect optlen %d rt %d => ", 825 optlen, opts->m_len); 826 #endif 827 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 828 opt = cp[IPOPT_OPTVAL]; 829 if (opt == IPOPT_EOL) 830 break; 831 if (opt == IPOPT_NOP) 832 len = 1; 833 else { 834 if (cnt < IPOPT_OLEN + sizeof(*cp)) 835 break; 836 len = cp[IPOPT_OLEN]; 837 if (len < IPOPT_OLEN + sizeof(*cp) || 838 len > cnt) 839 break; 840 } 841 /* 842 * Should check for overflow, but it "can't happen" 843 */ 844 if (opt == IPOPT_RR || opt == IPOPT_TS || 845 opt == IPOPT_SECURITY) { 846 memmove(mtod(opts, char *) + opts->m_len, 847 cp, len); 848 opts->m_len += len; 849 } 850 } 851 /* Terminate & pad, if necessary */ 852 if ((cnt = opts->m_len % 4) != 0) { 853 for (; cnt < 4; cnt++) { 854 *(mtod(opts, char *) + opts->m_len) = 855 IPOPT_EOL; 856 opts->m_len++; 857 } 858 } 859 #ifdef ICMPPRINTFS 860 if (icmpprintfs) 861 printf("%d\n", opts->m_len); 862 #endif 863 } 864 /* 865 * Now strip out original options by copying rest of first 866 * mbuf's data back, and adjust the IP length. 867 */ 868 ip->ip_len = htons(ntohs(ip->ip_len) - optlen); 869 ip->ip_hl = sizeof(struct ip) >> 2; 870 m->m_len -= optlen; 871 if (m->m_flags & M_PKTHDR) 872 m->m_pkthdr.len -= optlen; 873 optlen += sizeof(struct ip); 874 memmove(ip + 1, (char *)ip + optlen, 875 (unsigned)(m->m_len - sizeof(struct ip))); 876 } 877 m_tag_delete_nonpersistent(m); 878 m->m_flags &= ~(M_BCAST|M_MCAST); 879 880 /* 881 * Clear any in-bound checksum flags for this packet. 882 */ 883 if (m->m_flags & M_PKTHDR) 884 m->m_pkthdr.csum_flags = 0; 885 886 icmp_send(m, opts); 887 done: 888 if (opts) 889 (void)m_free(opts); 890 } 891 892 /* 893 * Send an icmp packet back to the ip level, 894 * after supplying a checksum. 895 */ 896 void 897 icmp_send(struct mbuf *m, struct mbuf *opts) 898 { 899 struct ip *ip = mtod(m, struct ip *); 900 int hlen; 901 struct icmp *icp; 902 903 hlen = ip->ip_hl << 2; 904 m->m_data += hlen; 905 m->m_len -= hlen; 906 icp = mtod(m, struct icmp *); 907 icp->icmp_cksum = 0; 908 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 909 m->m_data -= hlen; 910 m->m_len += hlen; 911 #ifdef ICMPPRINTFS 912 if (icmpprintfs) { 913 printf("icmp_send to destination `%s' from `%s'\n", 914 inet_ntoa(ip->ip_dst), inet_ntoa(ip->ip_src)); 915 } 916 #endif 917 (void)ip_output(m, opts, NULL, 0, NULL, NULL); 918 } 919 920 n_time 921 iptime(void) 922 { 923 struct timeval atv; 924 u_long t; 925 926 microtime(&atv); 927 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 928 return (htonl(t)); 929 } 930 931 /* 932 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures 933 * that the new value is in the correct range. 934 */ 935 static int 936 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) 937 { 938 int error, t; 939 struct sysctlnode node; 940 941 node = *rnode; 942 node.sysctl_data = &t; 943 t = icmpreturndatabytes; 944 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 945 if (error || newp == NULL) 946 return (error); 947 948 if (t < 8 || t > 512) 949 return (EINVAL); 950 icmpreturndatabytes = t; 951 952 return (0); 953 } 954 955 /* 956 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that 957 * the given value is not less than zero and then resets the timeout 958 * queue. 959 */ 960 static int 961 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) 962 { 963 int error, tmp; 964 struct sysctlnode node; 965 966 node = *rnode; 967 node.sysctl_data = &tmp; 968 tmp = icmp_redirtimeout; 969 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 970 if (error || newp == NULL) 971 return (error); 972 if (tmp < 0) 973 return (EINVAL); 974 icmp_redirtimeout = tmp; 975 976 /* 977 * was it a *defined* side-effect that anyone even *reading* 978 * this value causes these things to happen? 979 */ 980 if (icmp_redirect_timeout_q != NULL) { 981 if (icmp_redirtimeout == 0) { 982 rt_timer_queue_destroy(icmp_redirect_timeout_q, 983 true); 984 icmp_redirect_timeout_q = NULL; 985 } else { 986 rt_timer_queue_change(icmp_redirect_timeout_q, 987 icmp_redirtimeout); 988 } 989 } else if (icmp_redirtimeout > 0) { 990 icmp_redirect_timeout_q = 991 rt_timer_queue_create(icmp_redirtimeout); 992 } 993 994 return (0); 995 } 996 997 static int 998 sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) 999 { 1000 1001 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); 1002 } 1003 1004 static void 1005 sysctl_netinet_icmp_setup(struct sysctllog **clog) 1006 { 1007 1008 sysctl_createv(clog, 0, NULL, NULL, 1009 CTLFLAG_PERMANENT, 1010 CTLTYPE_NODE, "net", NULL, 1011 NULL, 0, NULL, 0, 1012 CTL_NET, CTL_EOL); 1013 sysctl_createv(clog, 0, NULL, NULL, 1014 CTLFLAG_PERMANENT, 1015 CTLTYPE_NODE, "inet", NULL, 1016 NULL, 0, NULL, 0, 1017 CTL_NET, PF_INET, CTL_EOL); 1018 sysctl_createv(clog, 0, NULL, NULL, 1019 CTLFLAG_PERMANENT, 1020 CTLTYPE_NODE, "icmp", 1021 SYSCTL_DESCR("ICMPv4 related settings"), 1022 NULL, 0, NULL, 0, 1023 CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL); 1024 1025 sysctl_createv(clog, 0, NULL, NULL, 1026 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1027 CTLTYPE_INT, "maskrepl", 1028 SYSCTL_DESCR("Respond to ICMP_MASKREQ messages"), 1029 NULL, 0, &icmpmaskrepl, 0, 1030 CTL_NET, PF_INET, IPPROTO_ICMP, 1031 ICMPCTL_MASKREPL, CTL_EOL); 1032 sysctl_createv(clog, 0, NULL, NULL, 1033 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1034 CTLTYPE_INT, "returndatabytes", 1035 SYSCTL_DESCR("Number of bytes to return in an ICMP " 1036 "error message"), 1037 sysctl_net_inet_icmp_returndatabytes, 0, 1038 &icmpreturndatabytes, 0, 1039 CTL_NET, PF_INET, IPPROTO_ICMP, 1040 ICMPCTL_RETURNDATABYTES, CTL_EOL); 1041 sysctl_createv(clog, 0, NULL, NULL, 1042 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1043 CTLTYPE_INT, "errppslimit", 1044 SYSCTL_DESCR("Maximum number of outgoing ICMP error " 1045 "messages per second"), 1046 NULL, 0, &icmperrppslim, 0, 1047 CTL_NET, PF_INET, IPPROTO_ICMP, 1048 ICMPCTL_ERRPPSLIMIT, CTL_EOL); 1049 sysctl_createv(clog, 0, NULL, NULL, 1050 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1051 CTLTYPE_INT, "rediraccept", 1052 SYSCTL_DESCR("Accept ICMP_REDIRECT messages"), 1053 NULL, 0, &icmp_rediraccept, 0, 1054 CTL_NET, PF_INET, IPPROTO_ICMP, 1055 ICMPCTL_REDIRACCEPT, CTL_EOL); 1056 sysctl_createv(clog, 0, NULL, NULL, 1057 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1058 CTLTYPE_INT, "redirtimeout", 1059 SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated " 1060 "routes"), 1061 sysctl_net_inet_icmp_redirtimeout, 0, 1062 &icmp_redirtimeout, 0, 1063 CTL_NET, PF_INET, IPPROTO_ICMP, 1064 ICMPCTL_REDIRTIMEOUT, CTL_EOL); 1065 sysctl_createv(clog, 0, NULL, NULL, 1066 CTLFLAG_PERMANENT, 1067 CTLTYPE_STRUCT, "stats", 1068 SYSCTL_DESCR("ICMP statistics"), 1069 sysctl_net_inet_icmp_stats, 0, NULL, 0, 1070 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS, 1071 CTL_EOL); 1072 sysctl_createv(clog, 0, NULL, NULL, 1073 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1074 CTLTYPE_INT, "bmcastecho", 1075 SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP " 1076 "message to the broadcast or multicast"), 1077 NULL, 0, &icmpbmcastecho, 0, 1078 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO, 1079 CTL_EOL); 1080 } 1081 1082 void 1083 icmp_statinc(u_int stat) 1084 { 1085 1086 KASSERT(stat < ICMP_NSTATS); 1087 ICMP_STATINC(stat); 1088 } 1089 1090 /* Table of common MTUs: */ 1091 1092 static const u_int mtu_table[] = { 1093 65535, 65280, 32000, 17914, 9180, 8166, 1094 4352, 2002, 1492, 1006, 508, 296, 68, 0 1095 }; 1096 1097 void 1098 icmp_mtudisc(struct icmp *icp, struct in_addr faddr) 1099 { 1100 struct icmp_mtudisc_callback *mc; 1101 struct sockaddr *dst = sintosa(&icmpsrc); 1102 struct rtentry *rt; 1103 u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */ 1104 int error; 1105 1106 rt = rtalloc1(dst, 1); 1107 if (rt == 0) 1108 return; 1109 1110 /* If we didn't get a host route, allocate one */ 1111 1112 if ((rt->rt_flags & RTF_HOST) == 0) { 1113 struct rtentry *nrt; 1114 1115 error = rtrequest((int) RTM_ADD, dst, 1116 (struct sockaddr *) rt->rt_gateway, 1117 (struct sockaddr *) 0, 1118 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); 1119 if (error) { 1120 rtfree(rt); 1121 return; 1122 } 1123 nrt->rt_rmx = rt->rt_rmx; 1124 rtfree(rt); 1125 rt = nrt; 1126 } 1127 error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q); 1128 if (error) { 1129 rtfree(rt); 1130 return; 1131 } 1132 1133 if (mtu == 0) { 1134 int i = 0; 1135 1136 mtu = ntohs(icp->icmp_ip.ip_len); 1137 /* Some 4.2BSD-based routers incorrectly adjust the ip_len */ 1138 if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0) 1139 mtu -= (icp->icmp_ip.ip_hl << 2); 1140 1141 /* If we still can't guess a value, try the route */ 1142 1143 if (mtu == 0) { 1144 mtu = rt->rt_rmx.rmx_mtu; 1145 1146 /* If no route mtu, default to the interface mtu */ 1147 1148 if (mtu == 0) 1149 mtu = rt->rt_ifp->if_mtu; 1150 } 1151 1152 for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++) 1153 if (mtu > mtu_table[i]) { 1154 mtu = mtu_table[i]; 1155 break; 1156 } 1157 } 1158 1159 /* 1160 * XXX: RTV_MTU is overloaded, since the admin can set it 1161 * to turn off PMTU for a route, and the kernel can 1162 * set it to indicate a serious problem with PMTU 1163 * on a route. We should be using a separate flag 1164 * for the kernel to indicate this. 1165 */ 1166 1167 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1168 if (mtu < 296 || mtu > rt->rt_ifp->if_mtu) 1169 rt->rt_rmx.rmx_locks |= RTV_MTU; 1170 else if (rt->rt_rmx.rmx_mtu > mtu || 1171 rt->rt_rmx.rmx_mtu == 0) { 1172 ICMP_STATINC(ICMP_STAT_PMTUCHG); 1173 rt->rt_rmx.rmx_mtu = mtu; 1174 } 1175 } 1176 1177 if (rt) 1178 rtfree(rt); 1179 1180 /* 1181 * Notify protocols that the MTU for this destination 1182 * has changed. 1183 */ 1184 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 1185 mc = LIST_NEXT(mc, mc_list)) 1186 (*mc->mc_func)(faddr); 1187 } 1188 1189 /* 1190 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1191 * given current value MTU. If DIR is less than zero, a larger plateau 1192 * is returned; otherwise, a smaller value is returned. 1193 */ 1194 u_int 1195 ip_next_mtu(u_int mtu, int dir) /* XXX */ 1196 { 1197 int i; 1198 1199 for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) { 1200 if (mtu >= mtu_table[i]) 1201 break; 1202 } 1203 1204 if (dir < 0) { 1205 if (i == 0) { 1206 return 0; 1207 } else { 1208 return mtu_table[i - 1]; 1209 } 1210 } else { 1211 if (mtu_table[i] == 0) { 1212 return 0; 1213 } else if (mtu > mtu_table[i]) { 1214 return mtu_table[i]; 1215 } else { 1216 return mtu_table[i + 1]; 1217 } 1218 } 1219 } 1220 1221 static void 1222 icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) 1223 { 1224 if (rt == NULL) 1225 panic("icmp_mtudisc_timeout: bad route to timeout"); 1226 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1227 (RTF_DYNAMIC | RTF_HOST)) { 1228 rtrequest((int) RTM_DELETE, rt_getkey(rt), 1229 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1230 } else { 1231 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1232 rt->rt_rmx.rmx_mtu = 0; 1233 } 1234 } 1235 } 1236 1237 static void 1238 icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r) 1239 { 1240 if (rt == NULL) 1241 panic("icmp_redirect_timeout: bad route to timeout"); 1242 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1243 (RTF_DYNAMIC | RTF_HOST)) { 1244 rtrequest((int) RTM_DELETE, rt_getkey(rt), 1245 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1246 } 1247 } 1248 1249 /* 1250 * Perform rate limit check. 1251 * Returns 0 if it is okay to send the icmp packet. 1252 * Returns 1 if the router SHOULD NOT send this icmp packet due to rate 1253 * limitation. 1254 * 1255 * XXX per-destination/type check necessary? 1256 */ 1257 int 1258 icmp_ratelimit(const struct in_addr *dst, const int type, 1259 const int code) 1260 { 1261 1262 /* PPS limit */ 1263 if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count, 1264 icmperrppslim)) { 1265 /* The packet is subject to rate limit */ 1266 return 1; 1267 } 1268 1269 /* okay to send */ 1270 return 0; 1271 } 1272