1 /* $NetBSD: ip_icmp.c,v 1.129 2012/03/22 20:34:38 drochner 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 1.129 2012/03/22 20:34:38 drochner 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 FAST_IPSEC 127 #include <netipsec/ipsec.h> 128 #include <netipsec/key.h> 129 #endif /* FAST_IPSEC*/ 130 131 /* 132 * ICMP routines: error generation, receive packet processing, and 133 * routines to turnaround packets back to the originator, and 134 * host table maintenance routines. 135 */ 136 137 int icmpmaskrepl = 0; 138 int icmpbmcastecho = 0; 139 #ifdef ICMPPRINTFS 140 int icmpprintfs = 0; 141 #endif 142 int icmpreturndatabytes = 8; 143 144 percpu_t *icmpstat_percpu; 145 146 /* 147 * List of callbacks to notify when Path MTU changes are made. 148 */ 149 struct icmp_mtudisc_callback { 150 LIST_ENTRY(icmp_mtudisc_callback) mc_list; 151 void (*mc_func)(struct in_addr); 152 }; 153 154 LIST_HEAD(, icmp_mtudisc_callback) icmp_mtudisc_callbacks = 155 LIST_HEAD_INITIALIZER(&icmp_mtudisc_callbacks); 156 157 #if 0 158 static u_int ip_next_mtu(u_int, int); 159 #else 160 /*static*/ u_int ip_next_mtu(u_int, int); 161 #endif 162 163 extern int icmperrppslim; 164 static int icmperrpps_count = 0; 165 static struct timeval icmperrppslim_last; 166 static int icmp_rediraccept = 1; 167 static int icmp_redirtimeout = 600; 168 static struct rttimer_queue *icmp_redirect_timeout_q = NULL; 169 170 static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *); 171 static void icmp_redirect_timeout(struct rtentry *, struct rttimer *); 172 173 static void sysctl_netinet_icmp_setup(struct sysctllog **); 174 175 void 176 icmp_init(void) 177 { 178 179 sysctl_netinet_icmp_setup(NULL); 180 181 /* 182 * This is only useful if the user initializes redirtimeout to 183 * something other than zero. 184 */ 185 if (icmp_redirtimeout != 0) { 186 icmp_redirect_timeout_q = 187 rt_timer_queue_create(icmp_redirtimeout); 188 } 189 190 icmpstat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP_NSTATS); 191 } 192 193 /* 194 * Register a Path MTU Discovery callback. 195 */ 196 void 197 icmp_mtudisc_callback_register(void (*func)(struct in_addr)) 198 { 199 struct icmp_mtudisc_callback *mc; 200 201 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 202 mc = LIST_NEXT(mc, mc_list)) { 203 if (mc->mc_func == func) 204 return; 205 } 206 207 mc = malloc(sizeof(*mc), M_PCB, M_NOWAIT); 208 if (mc == NULL) 209 panic("icmp_mtudisc_callback_register"); 210 211 mc->mc_func = func; 212 LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, mc, mc_list); 213 } 214 215 /* 216 * Generate an error packet of type error 217 * in response to bad packet ip. 218 */ 219 void 220 icmp_error(struct mbuf *n, int type, int code, n_long dest, 221 int destmtu) 222 { 223 struct ip *oip = mtod(n, struct ip *), *nip; 224 unsigned oiplen = oip->ip_hl << 2; 225 struct icmp *icp; 226 struct mbuf *m; 227 struct m_tag *mtag; 228 unsigned icmplen, mblen; 229 230 #ifdef ICMPPRINTFS 231 if (icmpprintfs) 232 printf("icmp_error(%p, type:%d, code:%d)\n", oip, type, code); 233 #endif 234 if (type != ICMP_REDIRECT) 235 ICMP_STATINC(ICMP_STAT_ERROR); 236 /* 237 * Don't send error if the original packet was encrypted. 238 * Don't send error if not the first fragment of message. 239 * Don't error if the old packet protocol was ICMP 240 * error message, only known informational types. 241 */ 242 if (n->m_flags & M_DECRYPTED) 243 goto freeit; 244 if (oip->ip_off &~ htons(IP_MF|IP_DF)) 245 goto freeit; 246 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 247 n->m_len >= oiplen + ICMP_MINLEN && 248 !ICMP_INFOTYPE(((struct icmp *)((char *)oip + oiplen))->icmp_type)) { 249 ICMP_STATINC(ICMP_STAT_OLDICMP); 250 goto freeit; 251 } 252 /* Don't send error in response to a multicast or broadcast packet */ 253 if (n->m_flags & (M_BCAST|M_MCAST)) 254 goto freeit; 255 256 /* 257 * First, do a rate limitation check. 258 */ 259 if (icmp_ratelimit(&oip->ip_src, type, code)) { 260 /* XXX stat */ 261 goto freeit; 262 } 263 264 /* 265 * Now, formulate icmp message 266 */ 267 icmplen = oiplen + min(icmpreturndatabytes, 268 ntohs(oip->ip_len) - oiplen); 269 /* 270 * Defend against mbuf chains shorter than oip->ip_len - oiplen: 271 */ 272 mblen = 0; 273 for (m = n; m && (mblen < icmplen); m = m->m_next) 274 mblen += m->m_len; 275 icmplen = min(mblen, icmplen); 276 277 /* 278 * As we are not required to return everything we have, 279 * we return whatever we can return at ease. 280 * 281 * Note that ICMP datagrams longer than 576 octets are out of spec 282 * according to RFC1812; the limit on icmpreturndatabytes below in 283 * icmp_sysctl will keep things below that limit. 284 */ 285 286 KASSERT(ICMP_MINLEN <= MCLBYTES); 287 288 if (icmplen + ICMP_MINLEN > MCLBYTES) 289 icmplen = MCLBYTES - ICMP_MINLEN; 290 291 m = m_gethdr(M_DONTWAIT, MT_HEADER); 292 if (m && (icmplen + ICMP_MINLEN > MHLEN)) { 293 MCLGET(m, M_DONTWAIT); 294 if ((m->m_flags & M_EXT) == 0) { 295 m_freem(m); 296 m = NULL; 297 } 298 } 299 if (m == NULL) 300 goto freeit; 301 MCLAIM(m, n->m_owner); 302 m->m_len = icmplen + ICMP_MINLEN; 303 if ((m->m_flags & M_EXT) == 0) 304 MH_ALIGN(m, m->m_len); 305 else { 306 m->m_data += sizeof(struct ip); 307 m->m_len -= sizeof(struct ip); 308 } 309 icp = mtod(m, struct icmp *); 310 if ((u_int)type > ICMP_MAXTYPE) 311 panic("icmp_error"); 312 ICMP_STATINC(ICMP_STAT_OUTHIST + type); 313 icp->icmp_type = type; 314 if (type == ICMP_REDIRECT) 315 icp->icmp_gwaddr.s_addr = dest; 316 else { 317 icp->icmp_void = 0; 318 /* 319 * The following assignments assume an overlay with the 320 * zeroed icmp_void field. 321 */ 322 if (type == ICMP_PARAMPROB) { 323 icp->icmp_pptr = code; 324 code = 0; 325 } else if (type == ICMP_UNREACH && 326 code == ICMP_UNREACH_NEEDFRAG && destmtu) 327 icp->icmp_nextmtu = htons(destmtu); 328 } 329 330 icp->icmp_code = code; 331 m_copydata(n, 0, icmplen, (void *)&icp->icmp_ip); 332 333 /* 334 * Now, copy old ip header (without options) 335 * in front of icmp message. 336 */ 337 if ((m->m_flags & M_EXT) == 0 && 338 m->m_data - sizeof(struct ip) < m->m_pktdat) 339 panic("icmp len"); 340 m->m_data -= sizeof(struct ip); 341 m->m_len += sizeof(struct ip); 342 m->m_pkthdr.len = m->m_len; 343 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif; 344 nip = mtod(m, struct ip *); 345 /* ip_v set in ip_output */ 346 nip->ip_hl = sizeof(struct ip) >> 2; 347 nip->ip_tos = 0; 348 nip->ip_len = htons(m->m_len); 349 /* ip_id set in ip_output */ 350 nip->ip_off = htons(0); 351 /* ip_ttl set in icmp_reflect */ 352 nip->ip_p = IPPROTO_ICMP; 353 nip->ip_src = oip->ip_src; 354 nip->ip_dst = oip->ip_dst; 355 /* move PF m_tag to new packet, if it exists */ 356 mtag = m_tag_find(n, PACKET_TAG_PF, NULL); 357 if (mtag != NULL) { 358 m_tag_unlink(n, mtag); 359 m_tag_prepend(m, mtag); 360 } 361 icmp_reflect(m); 362 363 freeit: 364 m_freem(n); 365 } 366 367 struct sockaddr_in icmpsrc = { 368 .sin_len = sizeof (struct sockaddr_in), 369 .sin_family = AF_INET, 370 }; 371 static struct sockaddr_in icmpdst = { 372 .sin_len = sizeof (struct sockaddr_in), 373 .sin_family = AF_INET, 374 }; 375 static struct sockaddr_in icmpgw = { 376 .sin_len = sizeof (struct sockaddr_in), 377 .sin_family = AF_INET, 378 }; 379 struct sockaddr_in icmpmask = { 380 .sin_len = 8, 381 .sin_family = 0, 382 }; 383 384 /* 385 * Process a received ICMP message. 386 */ 387 void 388 icmp_input(struct mbuf *m, ...) 389 { 390 int proto; 391 struct icmp *icp; 392 struct ip *ip = mtod(m, struct ip *); 393 int icmplen; 394 int i; 395 struct in_ifaddr *ia; 396 void *(*ctlfunc)(int, const struct sockaddr *, void *); 397 int code; 398 int hlen; 399 va_list ap; 400 struct rtentry *rt; 401 402 va_start(ap, m); 403 hlen = va_arg(ap, int); 404 proto = va_arg(ap, int); 405 va_end(ap); 406 407 /* 408 * Locate icmp structure in mbuf, and check 409 * that not corrupted and of at least minimum length. 410 */ 411 icmplen = ntohs(ip->ip_len) - hlen; 412 #ifdef ICMPPRINTFS 413 if (icmpprintfs) { 414 printf("icmp_input from `%s' to ", inet_ntoa(ip->ip_src)); 415 printf("`%s', len %d\n", inet_ntoa(ip->ip_dst), icmplen); 416 } 417 #endif 418 if (icmplen < ICMP_MINLEN) { 419 ICMP_STATINC(ICMP_STAT_TOOSHORT); 420 goto freeit; 421 } 422 i = hlen + min(icmplen, ICMP_ADVLENMIN); 423 if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == NULL) { 424 ICMP_STATINC(ICMP_STAT_TOOSHORT); 425 return; 426 } 427 ip = mtod(m, struct ip *); 428 m->m_len -= hlen; 429 m->m_data += hlen; 430 icp = mtod(m, struct icmp *); 431 /* Don't need to assert alignment, here. */ 432 if (in_cksum(m, icmplen)) { 433 ICMP_STATINC(ICMP_STAT_CHECKSUM); 434 goto freeit; 435 } 436 m->m_len += hlen; 437 m->m_data -= hlen; 438 439 #ifdef ICMPPRINTFS 440 /* 441 * Message type specific processing. 442 */ 443 if (icmpprintfs) 444 printf("icmp_input(type:%d, code:%d)\n", icp->icmp_type, 445 icp->icmp_code); 446 #endif 447 if (icp->icmp_type > ICMP_MAXTYPE) 448 goto raw; 449 ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type); 450 code = icp->icmp_code; 451 switch (icp->icmp_type) { 452 453 case ICMP_UNREACH: 454 switch (code) { 455 case ICMP_UNREACH_NET: 456 code = PRC_UNREACH_NET; 457 break; 458 459 case ICMP_UNREACH_HOST: 460 code = PRC_UNREACH_HOST; 461 break; 462 463 case ICMP_UNREACH_PROTOCOL: 464 code = PRC_UNREACH_PROTOCOL; 465 break; 466 467 case ICMP_UNREACH_PORT: 468 code = PRC_UNREACH_PORT; 469 break; 470 471 case ICMP_UNREACH_SRCFAIL: 472 code = PRC_UNREACH_SRCFAIL; 473 break; 474 475 case ICMP_UNREACH_NEEDFRAG: 476 code = PRC_MSGSIZE; 477 break; 478 479 case ICMP_UNREACH_NET_UNKNOWN: 480 case ICMP_UNREACH_NET_PROHIB: 481 case ICMP_UNREACH_TOSNET: 482 code = PRC_UNREACH_NET; 483 break; 484 485 case ICMP_UNREACH_HOST_UNKNOWN: 486 case ICMP_UNREACH_ISOLATED: 487 case ICMP_UNREACH_HOST_PROHIB: 488 case ICMP_UNREACH_TOSHOST: 489 code = PRC_UNREACH_HOST; 490 break; 491 492 default: 493 goto badcode; 494 } 495 goto deliver; 496 497 case ICMP_TIMXCEED: 498 if (code > 1) 499 goto badcode; 500 code += PRC_TIMXCEED_INTRANS; 501 goto deliver; 502 503 case ICMP_PARAMPROB: 504 if (code > 1) 505 goto badcode; 506 code = PRC_PARAMPROB; 507 goto deliver; 508 509 case ICMP_SOURCEQUENCH: 510 if (code) 511 goto badcode; 512 code = PRC_QUENCH; 513 goto deliver; 514 515 deliver: 516 /* 517 * Problem with datagram; advise higher level routines. 518 */ 519 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 520 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 521 ICMP_STATINC(ICMP_STAT_BADLEN); 522 goto freeit; 523 } 524 if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) 525 goto badcode; 526 #ifdef ICMPPRINTFS 527 if (icmpprintfs) 528 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 529 #endif 530 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 531 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; 532 if (ctlfunc) 533 (void) (*ctlfunc)(code, sintosa(&icmpsrc), 534 &icp->icmp_ip); 535 break; 536 537 badcode: 538 ICMP_STATINC(ICMP_STAT_BADCODE); 539 break; 540 541 case ICMP_ECHO: 542 if (!icmpbmcastecho && 543 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 544 ICMP_STATINC(ICMP_STAT_BMCASTECHO); 545 break; 546 } 547 icp->icmp_type = ICMP_ECHOREPLY; 548 goto reflect; 549 550 case ICMP_TSTAMP: 551 if (icmplen < ICMP_TSLEN) { 552 ICMP_STATINC(ICMP_STAT_BADLEN); 553 break; 554 } 555 if (!icmpbmcastecho && 556 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 557 ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); 558 break; 559 } 560 icp->icmp_type = ICMP_TSTAMPREPLY; 561 icp->icmp_rtime = iptime(); 562 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 563 goto reflect; 564 565 case ICMP_MASKREQ: 566 if (icmpmaskrepl == 0) 567 break; 568 /* 569 * We are not able to respond with all ones broadcast 570 * unless we receive it over a point-to-point interface. 571 */ 572 if (icmplen < ICMP_MASKLEN) { 573 ICMP_STATINC(ICMP_STAT_BADLEN); 574 break; 575 } 576 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 577 in_nullhost(ip->ip_dst)) 578 icmpdst.sin_addr = ip->ip_src; 579 else 580 icmpdst.sin_addr = ip->ip_dst; 581 ia = ifatoia(ifaof_ifpforaddr(sintosa(&icmpdst), 582 m->m_pkthdr.rcvif)); 583 if (ia == 0) 584 break; 585 icp->icmp_type = ICMP_MASKREPLY; 586 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 587 if (in_nullhost(ip->ip_src)) { 588 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 589 ip->ip_src = ia->ia_broadaddr.sin_addr; 590 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 591 ip->ip_src = ia->ia_dstaddr.sin_addr; 592 } 593 reflect: 594 { 595 uint64_t *icps = percpu_getref(icmpstat_percpu); 596 icps[ICMP_STAT_REFLECT]++; 597 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; 598 percpu_putref(icmpstat_percpu); 599 } 600 icmp_reflect(m); 601 return; 602 603 case ICMP_REDIRECT: 604 if (code > 3) 605 goto badcode; 606 if (icmp_rediraccept == 0) 607 goto freeit; 608 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 609 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 610 ICMP_STATINC(ICMP_STAT_BADLEN); 611 break; 612 } 613 /* 614 * Short circuit routing redirects to force 615 * immediate change in the kernel's routing 616 * tables. The message is also handed to anyone 617 * listening on a raw socket (e.g. the routing 618 * daemon for use in updating its tables). 619 */ 620 icmpgw.sin_addr = ip->ip_src; 621 icmpdst.sin_addr = icp->icmp_gwaddr; 622 #ifdef ICMPPRINTFS 623 if (icmpprintfs) { 624 printf("redirect dst `%s' to `%s'\n", 625 inet_ntoa(icp->icmp_ip.ip_dst), 626 inet_ntoa(icp->icmp_gwaddr)); 627 } 628 #endif 629 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 630 rt = NULL; 631 rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst), 632 NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt); 633 if (rt != NULL && icmp_redirtimeout != 0) { 634 i = rt_timer_add(rt, icmp_redirect_timeout, 635 icmp_redirect_timeout_q); 636 if (i) 637 log(LOG_ERR, "ICMP: redirect failed to " 638 "register timeout for route to %x, " 639 "code %d\n", 640 icp->icmp_ip.ip_dst.s_addr, i); 641 } 642 if (rt != NULL) 643 rtfree(rt); 644 645 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); 646 #if defined(FAST_IPSEC) 647 key_sa_routechange((struct sockaddr *)&icmpsrc); 648 #endif 649 break; 650 651 /* 652 * No kernel processing for the following; 653 * just fall through to send to raw listener. 654 */ 655 case ICMP_ECHOREPLY: 656 case ICMP_ROUTERADVERT: 657 case ICMP_ROUTERSOLICIT: 658 case ICMP_TSTAMPREPLY: 659 case ICMP_IREQREPLY: 660 case ICMP_MASKREPLY: 661 default: 662 break; 663 } 664 665 raw: 666 rip_input(m, hlen, proto); 667 return; 668 669 freeit: 670 m_freem(m); 671 return; 672 } 673 674 /* 675 * Reflect the ip packet back to the source 676 */ 677 void 678 icmp_reflect(struct mbuf *m) 679 { 680 struct ip *ip = mtod(m, struct ip *); 681 struct in_ifaddr *ia; 682 struct ifaddr *ifa; 683 struct sockaddr_in *sin = 0; 684 struct in_addr t; 685 struct mbuf *opts = 0; 686 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 687 688 if (!in_canforward(ip->ip_src) && 689 ((ip->ip_src.s_addr & IN_CLASSA_NET) != 690 htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { 691 m_freem(m); /* Bad return address */ 692 goto done; /* ip_output() will check for broadcast */ 693 } 694 t = ip->ip_dst; 695 ip->ip_dst = ip->ip_src; 696 /* 697 * If the incoming packet was addressed directly to us, use 698 * dst as the src for the reply. Otherwise (broadcast or 699 * anonymous), use an address which corresponds to the 700 * incoming interface, with a preference for the address which 701 * corresponds to the route to the destination of the ICMP. 702 */ 703 704 /* Look for packet addressed to us */ 705 INADDR_TO_IA(t, ia); 706 707 /* look for packet sent to broadcast address */ 708 if (ia == NULL && m->m_pkthdr.rcvif && 709 (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST)) { 710 IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) { 711 if (ifa->ifa_addr->sa_family != AF_INET) 712 continue; 713 if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) { 714 ia = ifatoia(ifa); 715 break; 716 } 717 } 718 } 719 720 if (ia) 721 sin = &ia->ia_addr; 722 723 icmpdst.sin_addr = t; 724 725 /* 726 * if the packet is addressed somewhere else, compute the 727 * source address for packets routed back to the source, and 728 * use that, if it's an address on the interface which 729 * received the packet 730 */ 731 if (sin == NULL && m->m_pkthdr.rcvif) { 732 struct sockaddr_in sin_dst; 733 struct route icmproute; 734 int errornum; 735 736 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); 737 memset(&icmproute, 0, sizeof(icmproute)); 738 errornum = 0; 739 sin = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum); 740 /* errornum is never used */ 741 rtcache_free(&icmproute); 742 /* check to make sure sin is a source address on rcvif */ 743 if (sin) { 744 t = sin->sin_addr; 745 sin = NULL; 746 INADDR_TO_IA(t, ia); 747 while (ia) { 748 if (ia->ia_ifp == m->m_pkthdr.rcvif) { 749 sin = &ia->ia_addr; 750 break; 751 } 752 NEXT_IA_WITH_SAME_ADDR(ia); 753 } 754 } 755 } 756 757 /* 758 * if it was not addressed to us, but the route doesn't go out 759 * the source interface, pick an address on the source 760 * interface. This can happen when routing is asymmetric, or 761 * when the incoming packet was encapsulated 762 */ 763 if (sin == NULL && m->m_pkthdr.rcvif) { 764 IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) { 765 if (ifa->ifa_addr->sa_family != AF_INET) 766 continue; 767 sin = &(ifatoia(ifa)->ia_addr); 768 break; 769 } 770 } 771 772 /* 773 * The following happens if the packet was not addressed to us, 774 * and was received on an interface with no IP address: 775 * We find the first AF_INET address on the first non-loopback 776 * interface. 777 */ 778 if (sin == NULL) 779 TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) { 780 if (ia->ia_ifp->if_flags & IFF_LOOPBACK) 781 continue; 782 sin = &ia->ia_addr; 783 break; 784 } 785 786 /* 787 * If we still didn't find an address, punt. We could have an 788 * interface up (and receiving packets) with no address. 789 */ 790 if (sin == NULL) { 791 m_freem(m); 792 goto done; 793 } 794 795 ip->ip_src = sin->sin_addr; 796 ip->ip_ttl = MAXTTL; 797 798 if (optlen > 0) { 799 u_char *cp; 800 int opt, cnt; 801 u_int len; 802 803 /* 804 * Retrieve any source routing from the incoming packet; 805 * add on any record-route or timestamp options. 806 */ 807 cp = (u_char *) (ip + 1); 808 if ((opts = ip_srcroute()) == 0 && 809 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { 810 MCLAIM(opts, m->m_owner); 811 opts->m_len = sizeof(struct in_addr); 812 *mtod(opts, struct in_addr *) = zeroin_addr; 813 } 814 if (opts) { 815 #ifdef ICMPPRINTFS 816 if (icmpprintfs) 817 printf("icmp_reflect optlen %d rt %d => ", 818 optlen, opts->m_len); 819 #endif 820 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 821 opt = cp[IPOPT_OPTVAL]; 822 if (opt == IPOPT_EOL) 823 break; 824 if (opt == IPOPT_NOP) 825 len = 1; 826 else { 827 if (cnt < IPOPT_OLEN + sizeof(*cp)) 828 break; 829 len = cp[IPOPT_OLEN]; 830 if (len < IPOPT_OLEN + sizeof(*cp) || 831 len > cnt) 832 break; 833 } 834 /* 835 * Should check for overflow, but it "can't happen" 836 */ 837 if (opt == IPOPT_RR || opt == IPOPT_TS || 838 opt == IPOPT_SECURITY) { 839 memmove(mtod(opts, char *) + opts->m_len, 840 cp, len); 841 opts->m_len += len; 842 } 843 } 844 /* Terminate & pad, if necessary */ 845 if ((cnt = opts->m_len % 4) != 0) { 846 for (; cnt < 4; cnt++) { 847 *(mtod(opts, char *) + opts->m_len) = 848 IPOPT_EOL; 849 opts->m_len++; 850 } 851 } 852 #ifdef ICMPPRINTFS 853 if (icmpprintfs) 854 printf("%d\n", opts->m_len); 855 #endif 856 } 857 /* 858 * Now strip out original options by copying rest of first 859 * mbuf's data back, and adjust the IP length. 860 */ 861 ip->ip_len = htons(ntohs(ip->ip_len) - optlen); 862 ip->ip_hl = sizeof(struct ip) >> 2; 863 m->m_len -= optlen; 864 if (m->m_flags & M_PKTHDR) 865 m->m_pkthdr.len -= optlen; 866 optlen += sizeof(struct ip); 867 memmove(ip + 1, (char *)ip + optlen, 868 (unsigned)(m->m_len - sizeof(struct ip))); 869 } 870 m_tag_delete_nonpersistent(m); 871 m->m_flags &= ~(M_BCAST|M_MCAST); 872 873 /* 874 * Clear any in-bound checksum flags for this packet. 875 */ 876 if (m->m_flags & M_PKTHDR) 877 m->m_pkthdr.csum_flags = 0; 878 879 icmp_send(m, opts); 880 done: 881 if (opts) 882 (void)m_free(opts); 883 } 884 885 /* 886 * Send an icmp packet back to the ip level, 887 * after supplying a checksum. 888 */ 889 void 890 icmp_send(struct mbuf *m, struct mbuf *opts) 891 { 892 struct ip *ip = mtod(m, struct ip *); 893 int hlen; 894 struct icmp *icp; 895 896 hlen = ip->ip_hl << 2; 897 m->m_data += hlen; 898 m->m_len -= hlen; 899 icp = mtod(m, struct icmp *); 900 icp->icmp_cksum = 0; 901 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 902 m->m_data -= hlen; 903 m->m_len += hlen; 904 #ifdef ICMPPRINTFS 905 if (icmpprintfs) { 906 printf("icmp_send to destination `%s' from `%s'\n", 907 inet_ntoa(ip->ip_dst), inet_ntoa(ip->ip_src)); 908 } 909 #endif 910 (void)ip_output(m, opts, NULL, 0, NULL, NULL); 911 } 912 913 n_time 914 iptime(void) 915 { 916 struct timeval atv; 917 u_long t; 918 919 microtime(&atv); 920 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 921 return (htonl(t)); 922 } 923 924 /* 925 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures 926 * that the new value is in the correct range. 927 */ 928 static int 929 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) 930 { 931 int error, t; 932 struct sysctlnode node; 933 934 node = *rnode; 935 node.sysctl_data = &t; 936 t = icmpreturndatabytes; 937 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 938 if (error || newp == NULL) 939 return (error); 940 941 if (t < 8 || t > 512) 942 return (EINVAL); 943 icmpreturndatabytes = t; 944 945 return (0); 946 } 947 948 /* 949 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that 950 * the given value is not less than zero and then resets the timeout 951 * queue. 952 */ 953 static int 954 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) 955 { 956 int error, tmp; 957 struct sysctlnode node; 958 959 node = *rnode; 960 node.sysctl_data = &tmp; 961 tmp = icmp_redirtimeout; 962 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 963 if (error || newp == NULL) 964 return (error); 965 if (tmp < 0) 966 return (EINVAL); 967 icmp_redirtimeout = tmp; 968 969 /* 970 * was it a *defined* side-effect that anyone even *reading* 971 * this value causes these things to happen? 972 */ 973 if (icmp_redirect_timeout_q != NULL) { 974 if (icmp_redirtimeout == 0) { 975 rt_timer_queue_destroy(icmp_redirect_timeout_q, 976 true); 977 icmp_redirect_timeout_q = NULL; 978 } else { 979 rt_timer_queue_change(icmp_redirect_timeout_q, 980 icmp_redirtimeout); 981 } 982 } else if (icmp_redirtimeout > 0) { 983 icmp_redirect_timeout_q = 984 rt_timer_queue_create(icmp_redirtimeout); 985 } 986 987 return (0); 988 } 989 990 static int 991 sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) 992 { 993 994 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); 995 } 996 997 static void 998 sysctl_netinet_icmp_setup(struct sysctllog **clog) 999 { 1000 1001 sysctl_createv(clog, 0, NULL, NULL, 1002 CTLFLAG_PERMANENT, 1003 CTLTYPE_NODE, "net", NULL, 1004 NULL, 0, NULL, 0, 1005 CTL_NET, CTL_EOL); 1006 sysctl_createv(clog, 0, NULL, NULL, 1007 CTLFLAG_PERMANENT, 1008 CTLTYPE_NODE, "inet", NULL, 1009 NULL, 0, NULL, 0, 1010 CTL_NET, PF_INET, CTL_EOL); 1011 sysctl_createv(clog, 0, NULL, NULL, 1012 CTLFLAG_PERMANENT, 1013 CTLTYPE_NODE, "icmp", 1014 SYSCTL_DESCR("ICMPv4 related settings"), 1015 NULL, 0, NULL, 0, 1016 CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL); 1017 1018 sysctl_createv(clog, 0, NULL, NULL, 1019 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1020 CTLTYPE_INT, "maskrepl", 1021 SYSCTL_DESCR("Respond to ICMP_MASKREQ messages"), 1022 NULL, 0, &icmpmaskrepl, 0, 1023 CTL_NET, PF_INET, IPPROTO_ICMP, 1024 ICMPCTL_MASKREPL, CTL_EOL); 1025 sysctl_createv(clog, 0, NULL, NULL, 1026 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1027 CTLTYPE_INT, "returndatabytes", 1028 SYSCTL_DESCR("Number of bytes to return in an ICMP " 1029 "error message"), 1030 sysctl_net_inet_icmp_returndatabytes, 0, 1031 &icmpreturndatabytes, 0, 1032 CTL_NET, PF_INET, IPPROTO_ICMP, 1033 ICMPCTL_RETURNDATABYTES, CTL_EOL); 1034 sysctl_createv(clog, 0, NULL, NULL, 1035 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1036 CTLTYPE_INT, "errppslimit", 1037 SYSCTL_DESCR("Maximum number of outgoing ICMP error " 1038 "messages per second"), 1039 NULL, 0, &icmperrppslim, 0, 1040 CTL_NET, PF_INET, IPPROTO_ICMP, 1041 ICMPCTL_ERRPPSLIMIT, CTL_EOL); 1042 sysctl_createv(clog, 0, NULL, NULL, 1043 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1044 CTLTYPE_INT, "rediraccept", 1045 SYSCTL_DESCR("Accept ICMP_REDIRECT messages"), 1046 NULL, 0, &icmp_rediraccept, 0, 1047 CTL_NET, PF_INET, IPPROTO_ICMP, 1048 ICMPCTL_REDIRACCEPT, CTL_EOL); 1049 sysctl_createv(clog, 0, NULL, NULL, 1050 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1051 CTLTYPE_INT, "redirtimeout", 1052 SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated " 1053 "routes"), 1054 sysctl_net_inet_icmp_redirtimeout, 0, 1055 &icmp_redirtimeout, 0, 1056 CTL_NET, PF_INET, IPPROTO_ICMP, 1057 ICMPCTL_REDIRTIMEOUT, CTL_EOL); 1058 sysctl_createv(clog, 0, NULL, NULL, 1059 CTLFLAG_PERMANENT, 1060 CTLTYPE_STRUCT, "stats", 1061 SYSCTL_DESCR("ICMP statistics"), 1062 sysctl_net_inet_icmp_stats, 0, NULL, 0, 1063 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS, 1064 CTL_EOL); 1065 sysctl_createv(clog, 0, NULL, NULL, 1066 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1067 CTLTYPE_INT, "bmcastecho", 1068 SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP " 1069 "message to the broadcast or multicast"), 1070 NULL, 0, &icmpbmcastecho, 0, 1071 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO, 1072 CTL_EOL); 1073 } 1074 1075 void 1076 icmp_statinc(u_int stat) 1077 { 1078 1079 KASSERT(stat < ICMP_NSTATS); 1080 ICMP_STATINC(stat); 1081 } 1082 1083 /* Table of common MTUs: */ 1084 1085 static const u_int mtu_table[] = { 1086 65535, 65280, 32000, 17914, 9180, 8166, 1087 4352, 2002, 1492, 1006, 508, 296, 68, 0 1088 }; 1089 1090 void 1091 icmp_mtudisc(struct icmp *icp, struct in_addr faddr) 1092 { 1093 struct icmp_mtudisc_callback *mc; 1094 struct sockaddr *dst = sintosa(&icmpsrc); 1095 struct rtentry *rt; 1096 u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */ 1097 int error; 1098 1099 rt = rtalloc1(dst, 1); 1100 if (rt == 0) 1101 return; 1102 1103 /* If we didn't get a host route, allocate one */ 1104 1105 if ((rt->rt_flags & RTF_HOST) == 0) { 1106 struct rtentry *nrt; 1107 1108 error = rtrequest((int) RTM_ADD, dst, 1109 (struct sockaddr *) rt->rt_gateway, NULL, 1110 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); 1111 if (error) { 1112 rtfree(rt); 1113 return; 1114 } 1115 nrt->rt_rmx = rt->rt_rmx; 1116 rtfree(rt); 1117 rt = nrt; 1118 } 1119 error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q); 1120 if (error) { 1121 rtfree(rt); 1122 return; 1123 } 1124 1125 if (mtu == 0) { 1126 int i = 0; 1127 1128 mtu = ntohs(icp->icmp_ip.ip_len); 1129 /* Some 4.2BSD-based routers incorrectly adjust the ip_len */ 1130 if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0) 1131 mtu -= (icp->icmp_ip.ip_hl << 2); 1132 1133 /* If we still can't guess a value, try the route */ 1134 1135 if (mtu == 0) { 1136 mtu = rt->rt_rmx.rmx_mtu; 1137 1138 /* If no route mtu, default to the interface mtu */ 1139 1140 if (mtu == 0) 1141 mtu = rt->rt_ifp->if_mtu; 1142 } 1143 1144 for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++) 1145 if (mtu > mtu_table[i]) { 1146 mtu = mtu_table[i]; 1147 break; 1148 } 1149 } 1150 1151 /* 1152 * XXX: RTV_MTU is overloaded, since the admin can set it 1153 * to turn off PMTU for a route, and the kernel can 1154 * set it to indicate a serious problem with PMTU 1155 * on a route. We should be using a separate flag 1156 * for the kernel to indicate this. 1157 */ 1158 1159 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1160 if (mtu < 296 || mtu > rt->rt_ifp->if_mtu) 1161 rt->rt_rmx.rmx_locks |= RTV_MTU; 1162 else if (rt->rt_rmx.rmx_mtu > mtu || 1163 rt->rt_rmx.rmx_mtu == 0) { 1164 ICMP_STATINC(ICMP_STAT_PMTUCHG); 1165 rt->rt_rmx.rmx_mtu = mtu; 1166 } 1167 } 1168 1169 if (rt) 1170 rtfree(rt); 1171 1172 /* 1173 * Notify protocols that the MTU for this destination 1174 * has changed. 1175 */ 1176 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 1177 mc = LIST_NEXT(mc, mc_list)) 1178 (*mc->mc_func)(faddr); 1179 } 1180 1181 /* 1182 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1183 * given current value MTU. If DIR is less than zero, a larger plateau 1184 * is returned; otherwise, a smaller value is returned. 1185 */ 1186 u_int 1187 ip_next_mtu(u_int mtu, int dir) /* XXX */ 1188 { 1189 int i; 1190 1191 for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) { 1192 if (mtu >= mtu_table[i]) 1193 break; 1194 } 1195 1196 if (dir < 0) { 1197 if (i == 0) { 1198 return 0; 1199 } else { 1200 return mtu_table[i - 1]; 1201 } 1202 } else { 1203 if (mtu_table[i] == 0) { 1204 return 0; 1205 } else if (mtu > mtu_table[i]) { 1206 return mtu_table[i]; 1207 } else { 1208 return mtu_table[i + 1]; 1209 } 1210 } 1211 } 1212 1213 static void 1214 icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) 1215 { 1216 if (rt == NULL) 1217 panic("icmp_mtudisc_timeout: bad route to timeout"); 1218 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1219 (RTF_DYNAMIC | RTF_HOST)) { 1220 rtrequest((int) RTM_DELETE, rt_getkey(rt), 1221 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1222 } else { 1223 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1224 rt->rt_rmx.rmx_mtu = 0; 1225 } 1226 } 1227 } 1228 1229 static void 1230 icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r) 1231 { 1232 if (rt == NULL) 1233 panic("icmp_redirect_timeout: bad route to timeout"); 1234 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1235 (RTF_DYNAMIC | RTF_HOST)) { 1236 rtrequest((int) RTM_DELETE, rt_getkey(rt), 1237 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1238 } 1239 } 1240 1241 /* 1242 * Perform rate limit check. 1243 * Returns 0 if it is okay to send the icmp packet. 1244 * Returns 1 if the router SHOULD NOT send this icmp packet due to rate 1245 * limitation. 1246 * 1247 * XXX per-destination/type check necessary? 1248 */ 1249 int 1250 icmp_ratelimit(const struct in_addr *dst, const int type, 1251 const int code) 1252 { 1253 1254 /* PPS limit */ 1255 if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count, 1256 icmperrppslim)) { 1257 /* The packet is subject to rate limit */ 1258 return 1; 1259 } 1260 1261 /* okay to send */ 1262 return 0; 1263 } 1264