1 /* $NetBSD: ip_icmp.c,v 1.131 2013/06/05 19:01:26 christos 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 1.131 2013/06/05 19:01:26 christos 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 <netipsec/ipsec.h> 128 #include <netipsec/key.h> 129 #endif /* 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_PROTOCOL: 456 code = PRC_UNREACH_PROTOCOL; 457 break; 458 459 case ICMP_UNREACH_PORT: 460 code = PRC_UNREACH_PORT; 461 break; 462 463 case ICMP_UNREACH_SRCFAIL: 464 code = PRC_UNREACH_SRCFAIL; 465 break; 466 467 case ICMP_UNREACH_NEEDFRAG: 468 code = PRC_MSGSIZE; 469 break; 470 471 case ICMP_UNREACH_NET: 472 case ICMP_UNREACH_NET_UNKNOWN: 473 case ICMP_UNREACH_NET_PROHIB: 474 case ICMP_UNREACH_TOSNET: 475 code = PRC_UNREACH_NET; 476 break; 477 478 case ICMP_UNREACH_HOST: 479 case ICMP_UNREACH_HOST_UNKNOWN: 480 case ICMP_UNREACH_ISOLATED: 481 case ICMP_UNREACH_HOST_PROHIB: 482 case ICMP_UNREACH_TOSHOST: 483 case ICMP_UNREACH_ADMIN_PROHIBIT: 484 case ICMP_UNREACH_HOST_PREC: 485 case ICMP_UNREACH_PREC_CUTOFF: 486 code = PRC_UNREACH_HOST; 487 break; 488 489 default: 490 goto badcode; 491 } 492 goto deliver; 493 494 case ICMP_TIMXCEED: 495 if (code > 1) 496 goto badcode; 497 code += PRC_TIMXCEED_INTRANS; 498 goto deliver; 499 500 case ICMP_PARAMPROB: 501 if (code > 1) 502 goto badcode; 503 code = PRC_PARAMPROB; 504 goto deliver; 505 506 case ICMP_SOURCEQUENCH: 507 if (code) 508 goto badcode; 509 code = PRC_QUENCH; 510 goto deliver; 511 512 deliver: 513 /* 514 * Problem with datagram; advise higher level routines. 515 */ 516 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 517 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 518 ICMP_STATINC(ICMP_STAT_BADLEN); 519 goto freeit; 520 } 521 if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) 522 goto badcode; 523 #ifdef ICMPPRINTFS 524 if (icmpprintfs) 525 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 526 #endif 527 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 528 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; 529 if (ctlfunc) 530 (void) (*ctlfunc)(code, sintosa(&icmpsrc), 531 &icp->icmp_ip); 532 break; 533 534 badcode: 535 ICMP_STATINC(ICMP_STAT_BADCODE); 536 break; 537 538 case ICMP_ECHO: 539 if (!icmpbmcastecho && 540 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 541 ICMP_STATINC(ICMP_STAT_BMCASTECHO); 542 break; 543 } 544 icp->icmp_type = ICMP_ECHOREPLY; 545 goto reflect; 546 547 case ICMP_TSTAMP: 548 if (icmplen < ICMP_TSLEN) { 549 ICMP_STATINC(ICMP_STAT_BADLEN); 550 break; 551 } 552 if (!icmpbmcastecho && 553 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 554 ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); 555 break; 556 } 557 icp->icmp_type = ICMP_TSTAMPREPLY; 558 icp->icmp_rtime = iptime(); 559 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 560 goto reflect; 561 562 case ICMP_MASKREQ: 563 if (icmpmaskrepl == 0) 564 break; 565 /* 566 * We are not able to respond with all ones broadcast 567 * unless we receive it over a point-to-point interface. 568 */ 569 if (icmplen < ICMP_MASKLEN) { 570 ICMP_STATINC(ICMP_STAT_BADLEN); 571 break; 572 } 573 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 574 in_nullhost(ip->ip_dst)) 575 icmpdst.sin_addr = ip->ip_src; 576 else 577 icmpdst.sin_addr = ip->ip_dst; 578 ia = ifatoia(ifaof_ifpforaddr(sintosa(&icmpdst), 579 m->m_pkthdr.rcvif)); 580 if (ia == 0) 581 break; 582 icp->icmp_type = ICMP_MASKREPLY; 583 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 584 if (in_nullhost(ip->ip_src)) { 585 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 586 ip->ip_src = ia->ia_broadaddr.sin_addr; 587 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 588 ip->ip_src = ia->ia_dstaddr.sin_addr; 589 } 590 reflect: 591 { 592 uint64_t *icps = percpu_getref(icmpstat_percpu); 593 icps[ICMP_STAT_REFLECT]++; 594 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; 595 percpu_putref(icmpstat_percpu); 596 } 597 icmp_reflect(m); 598 return; 599 600 case ICMP_REDIRECT: 601 if (code > 3) 602 goto badcode; 603 if (icmp_rediraccept == 0) 604 goto freeit; 605 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 606 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 607 ICMP_STATINC(ICMP_STAT_BADLEN); 608 break; 609 } 610 /* 611 * Short circuit routing redirects to force 612 * immediate change in the kernel's routing 613 * tables. The message is also handed to anyone 614 * listening on a raw socket (e.g. the routing 615 * daemon for use in updating its tables). 616 */ 617 icmpgw.sin_addr = ip->ip_src; 618 icmpdst.sin_addr = icp->icmp_gwaddr; 619 #ifdef ICMPPRINTFS 620 if (icmpprintfs) { 621 printf("redirect dst `%s' to `%s'\n", 622 inet_ntoa(icp->icmp_ip.ip_dst), 623 inet_ntoa(icp->icmp_gwaddr)); 624 } 625 #endif 626 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 627 rt = NULL; 628 rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst), 629 NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt); 630 if (rt != NULL && icmp_redirtimeout != 0) { 631 i = rt_timer_add(rt, icmp_redirect_timeout, 632 icmp_redirect_timeout_q); 633 if (i) 634 log(LOG_ERR, "ICMP: redirect failed to " 635 "register timeout for route to %x, " 636 "code %d\n", 637 icp->icmp_ip.ip_dst.s_addr, i); 638 } 639 if (rt != NULL) 640 rtfree(rt); 641 642 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); 643 #if defined(IPSEC) 644 key_sa_routechange((struct sockaddr *)&icmpsrc); 645 #endif 646 break; 647 648 /* 649 * No kernel processing for the following; 650 * just fall through to send to raw listener. 651 */ 652 case ICMP_ECHOREPLY: 653 case ICMP_ROUTERADVERT: 654 case ICMP_ROUTERSOLICIT: 655 case ICMP_TSTAMPREPLY: 656 case ICMP_IREQREPLY: 657 case ICMP_MASKREPLY: 658 default: 659 break; 660 } 661 662 raw: 663 rip_input(m, hlen, proto); 664 return; 665 666 freeit: 667 m_freem(m); 668 return; 669 } 670 671 /* 672 * Reflect the ip packet back to the source 673 */ 674 void 675 icmp_reflect(struct mbuf *m) 676 { 677 struct ip *ip = mtod(m, struct ip *); 678 struct in_ifaddr *ia; 679 struct ifaddr *ifa; 680 struct sockaddr_in *sin = 0; 681 struct in_addr t; 682 struct mbuf *opts = 0; 683 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 684 685 if (!in_canforward(ip->ip_src) && 686 ((ip->ip_src.s_addr & IN_CLASSA_NET) != 687 htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { 688 m_freem(m); /* Bad return address */ 689 goto done; /* ip_output() will check for broadcast */ 690 } 691 t = ip->ip_dst; 692 ip->ip_dst = ip->ip_src; 693 /* 694 * If the incoming packet was addressed directly to us, use 695 * dst as the src for the reply. Otherwise (broadcast or 696 * anonymous), use an address which corresponds to the 697 * incoming interface, with a preference for the address which 698 * corresponds to the route to the destination of the ICMP. 699 */ 700 701 /* Look for packet addressed to us */ 702 INADDR_TO_IA(t, ia); 703 704 /* look for packet sent to broadcast address */ 705 if (ia == NULL && m->m_pkthdr.rcvif && 706 (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST)) { 707 IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) { 708 if (ifa->ifa_addr->sa_family != AF_INET) 709 continue; 710 if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) { 711 ia = ifatoia(ifa); 712 break; 713 } 714 } 715 } 716 717 if (ia) 718 sin = &ia->ia_addr; 719 720 icmpdst.sin_addr = t; 721 722 /* 723 * if the packet is addressed somewhere else, compute the 724 * source address for packets routed back to the source, and 725 * use that, if it's an address on the interface which 726 * received the packet 727 */ 728 if (sin == NULL && m->m_pkthdr.rcvif) { 729 struct sockaddr_in sin_dst; 730 struct route icmproute; 731 int errornum; 732 733 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); 734 memset(&icmproute, 0, sizeof(icmproute)); 735 errornum = 0; 736 sin = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum); 737 /* errornum is never used */ 738 rtcache_free(&icmproute); 739 /* check to make sure sin is a source address on rcvif */ 740 if (sin) { 741 t = sin->sin_addr; 742 sin = NULL; 743 INADDR_TO_IA(t, ia); 744 while (ia) { 745 if (ia->ia_ifp == m->m_pkthdr.rcvif) { 746 sin = &ia->ia_addr; 747 break; 748 } 749 NEXT_IA_WITH_SAME_ADDR(ia); 750 } 751 } 752 } 753 754 /* 755 * if it was not addressed to us, but the route doesn't go out 756 * the source interface, pick an address on the source 757 * interface. This can happen when routing is asymmetric, or 758 * when the incoming packet was encapsulated 759 */ 760 if (sin == NULL && m->m_pkthdr.rcvif) { 761 IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) { 762 if (ifa->ifa_addr->sa_family != AF_INET) 763 continue; 764 sin = &(ifatoia(ifa)->ia_addr); 765 break; 766 } 767 } 768 769 /* 770 * The following happens if the packet was not addressed to us, 771 * and was received on an interface with no IP address: 772 * We find the first AF_INET address on the first non-loopback 773 * interface. 774 */ 775 if (sin == NULL) 776 TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) { 777 if (ia->ia_ifp->if_flags & IFF_LOOPBACK) 778 continue; 779 sin = &ia->ia_addr; 780 break; 781 } 782 783 /* 784 * If we still didn't find an address, punt. We could have an 785 * interface up (and receiving packets) with no address. 786 */ 787 if (sin == NULL) { 788 m_freem(m); 789 goto done; 790 } 791 792 ip->ip_src = sin->sin_addr; 793 ip->ip_ttl = MAXTTL; 794 795 if (optlen > 0) { 796 u_char *cp; 797 int opt, cnt; 798 u_int len; 799 800 /* 801 * Retrieve any source routing from the incoming packet; 802 * add on any record-route or timestamp options. 803 */ 804 cp = (u_char *) (ip + 1); 805 if ((opts = ip_srcroute()) == 0 && 806 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { 807 MCLAIM(opts, m->m_owner); 808 opts->m_len = sizeof(struct in_addr); 809 *mtod(opts, struct in_addr *) = zeroin_addr; 810 } 811 if (opts) { 812 #ifdef ICMPPRINTFS 813 if (icmpprintfs) 814 printf("icmp_reflect optlen %d rt %d => ", 815 optlen, opts->m_len); 816 #endif 817 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 818 opt = cp[IPOPT_OPTVAL]; 819 if (opt == IPOPT_EOL) 820 break; 821 if (opt == IPOPT_NOP) 822 len = 1; 823 else { 824 if (cnt < IPOPT_OLEN + sizeof(*cp)) 825 break; 826 len = cp[IPOPT_OLEN]; 827 if (len < IPOPT_OLEN + sizeof(*cp) || 828 len > cnt) 829 break; 830 } 831 /* 832 * Should check for overflow, but it "can't happen" 833 */ 834 if (opt == IPOPT_RR || opt == IPOPT_TS || 835 opt == IPOPT_SECURITY) { 836 memmove(mtod(opts, char *) + opts->m_len, 837 cp, len); 838 opts->m_len += len; 839 } 840 } 841 /* Terminate & pad, if necessary */ 842 if ((cnt = opts->m_len % 4) != 0) { 843 for (; cnt < 4; cnt++) { 844 *(mtod(opts, char *) + opts->m_len) = 845 IPOPT_EOL; 846 opts->m_len++; 847 } 848 } 849 #ifdef ICMPPRINTFS 850 if (icmpprintfs) 851 printf("%d\n", opts->m_len); 852 #endif 853 } 854 /* 855 * Now strip out original options by copying rest of first 856 * mbuf's data back, and adjust the IP length. 857 */ 858 ip->ip_len = htons(ntohs(ip->ip_len) - optlen); 859 ip->ip_hl = sizeof(struct ip) >> 2; 860 m->m_len -= optlen; 861 if (m->m_flags & M_PKTHDR) 862 m->m_pkthdr.len -= optlen; 863 optlen += sizeof(struct ip); 864 memmove(ip + 1, (char *)ip + optlen, 865 (unsigned)(m->m_len - sizeof(struct ip))); 866 } 867 m_tag_delete_nonpersistent(m); 868 m->m_flags &= ~(M_BCAST|M_MCAST); 869 870 /* 871 * Clear any in-bound checksum flags for this packet. 872 */ 873 if (m->m_flags & M_PKTHDR) 874 m->m_pkthdr.csum_flags = 0; 875 876 icmp_send(m, opts); 877 done: 878 if (opts) 879 (void)m_free(opts); 880 } 881 882 /* 883 * Send an icmp packet back to the ip level, 884 * after supplying a checksum. 885 */ 886 void 887 icmp_send(struct mbuf *m, struct mbuf *opts) 888 { 889 struct ip *ip = mtod(m, struct ip *); 890 int hlen; 891 struct icmp *icp; 892 893 hlen = ip->ip_hl << 2; 894 m->m_data += hlen; 895 m->m_len -= hlen; 896 icp = mtod(m, struct icmp *); 897 icp->icmp_cksum = 0; 898 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 899 m->m_data -= hlen; 900 m->m_len += hlen; 901 #ifdef ICMPPRINTFS 902 if (icmpprintfs) { 903 printf("icmp_send to destination `%s' from `%s'\n", 904 inet_ntoa(ip->ip_dst), inet_ntoa(ip->ip_src)); 905 } 906 #endif 907 (void)ip_output(m, opts, NULL, 0, NULL, NULL); 908 } 909 910 n_time 911 iptime(void) 912 { 913 struct timeval atv; 914 u_long t; 915 916 microtime(&atv); 917 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 918 return (htonl(t)); 919 } 920 921 /* 922 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures 923 * that the new value is in the correct range. 924 */ 925 static int 926 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) 927 { 928 int error, t; 929 struct sysctlnode node; 930 931 node = *rnode; 932 node.sysctl_data = &t; 933 t = icmpreturndatabytes; 934 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 935 if (error || newp == NULL) 936 return (error); 937 938 if (t < 8 || t > 512) 939 return (EINVAL); 940 icmpreturndatabytes = t; 941 942 return (0); 943 } 944 945 /* 946 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that 947 * the given value is not less than zero and then resets the timeout 948 * queue. 949 */ 950 static int 951 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) 952 { 953 int error, tmp; 954 struct sysctlnode node; 955 956 node = *rnode; 957 node.sysctl_data = &tmp; 958 tmp = icmp_redirtimeout; 959 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 960 if (error || newp == NULL) 961 return (error); 962 if (tmp < 0) 963 return (EINVAL); 964 icmp_redirtimeout = tmp; 965 966 /* 967 * was it a *defined* side-effect that anyone even *reading* 968 * this value causes these things to happen? 969 */ 970 if (icmp_redirect_timeout_q != NULL) { 971 if (icmp_redirtimeout == 0) { 972 rt_timer_queue_destroy(icmp_redirect_timeout_q, 973 true); 974 icmp_redirect_timeout_q = NULL; 975 } else { 976 rt_timer_queue_change(icmp_redirect_timeout_q, 977 icmp_redirtimeout); 978 } 979 } else if (icmp_redirtimeout > 0) { 980 icmp_redirect_timeout_q = 981 rt_timer_queue_create(icmp_redirtimeout); 982 } 983 984 return (0); 985 } 986 987 static int 988 sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) 989 { 990 991 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); 992 } 993 994 static void 995 sysctl_netinet_icmp_setup(struct sysctllog **clog) 996 { 997 998 sysctl_createv(clog, 0, NULL, NULL, 999 CTLFLAG_PERMANENT, 1000 CTLTYPE_NODE, "net", NULL, 1001 NULL, 0, NULL, 0, 1002 CTL_NET, CTL_EOL); 1003 sysctl_createv(clog, 0, NULL, NULL, 1004 CTLFLAG_PERMANENT, 1005 CTLTYPE_NODE, "inet", NULL, 1006 NULL, 0, NULL, 0, 1007 CTL_NET, PF_INET, CTL_EOL); 1008 sysctl_createv(clog, 0, NULL, NULL, 1009 CTLFLAG_PERMANENT, 1010 CTLTYPE_NODE, "icmp", 1011 SYSCTL_DESCR("ICMPv4 related settings"), 1012 NULL, 0, NULL, 0, 1013 CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL); 1014 1015 sysctl_createv(clog, 0, NULL, NULL, 1016 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1017 CTLTYPE_INT, "maskrepl", 1018 SYSCTL_DESCR("Respond to ICMP_MASKREQ messages"), 1019 NULL, 0, &icmpmaskrepl, 0, 1020 CTL_NET, PF_INET, IPPROTO_ICMP, 1021 ICMPCTL_MASKREPL, CTL_EOL); 1022 sysctl_createv(clog, 0, NULL, NULL, 1023 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1024 CTLTYPE_INT, "returndatabytes", 1025 SYSCTL_DESCR("Number of bytes to return in an ICMP " 1026 "error message"), 1027 sysctl_net_inet_icmp_returndatabytes, 0, 1028 &icmpreturndatabytes, 0, 1029 CTL_NET, PF_INET, IPPROTO_ICMP, 1030 ICMPCTL_RETURNDATABYTES, CTL_EOL); 1031 sysctl_createv(clog, 0, NULL, NULL, 1032 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1033 CTLTYPE_INT, "errppslimit", 1034 SYSCTL_DESCR("Maximum number of outgoing ICMP error " 1035 "messages per second"), 1036 NULL, 0, &icmperrppslim, 0, 1037 CTL_NET, PF_INET, IPPROTO_ICMP, 1038 ICMPCTL_ERRPPSLIMIT, CTL_EOL); 1039 sysctl_createv(clog, 0, NULL, NULL, 1040 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1041 CTLTYPE_INT, "rediraccept", 1042 SYSCTL_DESCR("Accept ICMP_REDIRECT messages"), 1043 NULL, 0, &icmp_rediraccept, 0, 1044 CTL_NET, PF_INET, IPPROTO_ICMP, 1045 ICMPCTL_REDIRACCEPT, CTL_EOL); 1046 sysctl_createv(clog, 0, NULL, NULL, 1047 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1048 CTLTYPE_INT, "redirtimeout", 1049 SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated " 1050 "routes"), 1051 sysctl_net_inet_icmp_redirtimeout, 0, 1052 &icmp_redirtimeout, 0, 1053 CTL_NET, PF_INET, IPPROTO_ICMP, 1054 ICMPCTL_REDIRTIMEOUT, CTL_EOL); 1055 sysctl_createv(clog, 0, NULL, NULL, 1056 CTLFLAG_PERMANENT, 1057 CTLTYPE_STRUCT, "stats", 1058 SYSCTL_DESCR("ICMP statistics"), 1059 sysctl_net_inet_icmp_stats, 0, NULL, 0, 1060 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS, 1061 CTL_EOL); 1062 sysctl_createv(clog, 0, NULL, NULL, 1063 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1064 CTLTYPE_INT, "bmcastecho", 1065 SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP " 1066 "message to the broadcast or multicast"), 1067 NULL, 0, &icmpbmcastecho, 0, 1068 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO, 1069 CTL_EOL); 1070 } 1071 1072 void 1073 icmp_statinc(u_int stat) 1074 { 1075 1076 KASSERT(stat < ICMP_NSTATS); 1077 ICMP_STATINC(stat); 1078 } 1079 1080 /* Table of common MTUs: */ 1081 1082 static const u_int mtu_table[] = { 1083 65535, 65280, 32000, 17914, 9180, 8166, 1084 4352, 2002, 1492, 1006, 508, 296, 68, 0 1085 }; 1086 1087 void 1088 icmp_mtudisc(struct icmp *icp, struct in_addr faddr) 1089 { 1090 struct icmp_mtudisc_callback *mc; 1091 struct sockaddr *dst = sintosa(&icmpsrc); 1092 struct rtentry *rt; 1093 u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */ 1094 int error; 1095 1096 rt = rtalloc1(dst, 1); 1097 if (rt == 0) 1098 return; 1099 1100 /* If we didn't get a host route, allocate one */ 1101 1102 if ((rt->rt_flags & RTF_HOST) == 0) { 1103 struct rtentry *nrt; 1104 1105 error = rtrequest((int) RTM_ADD, dst, 1106 (struct sockaddr *) rt->rt_gateway, NULL, 1107 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); 1108 if (error) { 1109 rtfree(rt); 1110 return; 1111 } 1112 nrt->rt_rmx = rt->rt_rmx; 1113 rtfree(rt); 1114 rt = nrt; 1115 } 1116 error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q); 1117 if (error) { 1118 rtfree(rt); 1119 return; 1120 } 1121 1122 if (mtu == 0) { 1123 int i = 0; 1124 1125 mtu = ntohs(icp->icmp_ip.ip_len); 1126 /* Some 4.2BSD-based routers incorrectly adjust the ip_len */ 1127 if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0) 1128 mtu -= (icp->icmp_ip.ip_hl << 2); 1129 1130 /* If we still can't guess a value, try the route */ 1131 1132 if (mtu == 0) { 1133 mtu = rt->rt_rmx.rmx_mtu; 1134 1135 /* If no route mtu, default to the interface mtu */ 1136 1137 if (mtu == 0) 1138 mtu = rt->rt_ifp->if_mtu; 1139 } 1140 1141 for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++) 1142 if (mtu > mtu_table[i]) { 1143 mtu = mtu_table[i]; 1144 break; 1145 } 1146 } 1147 1148 /* 1149 * XXX: RTV_MTU is overloaded, since the admin can set it 1150 * to turn off PMTU for a route, and the kernel can 1151 * set it to indicate a serious problem with PMTU 1152 * on a route. We should be using a separate flag 1153 * for the kernel to indicate this. 1154 */ 1155 1156 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1157 if (mtu < 296 || mtu > rt->rt_ifp->if_mtu) 1158 rt->rt_rmx.rmx_locks |= RTV_MTU; 1159 else if (rt->rt_rmx.rmx_mtu > mtu || 1160 rt->rt_rmx.rmx_mtu == 0) { 1161 ICMP_STATINC(ICMP_STAT_PMTUCHG); 1162 rt->rt_rmx.rmx_mtu = mtu; 1163 } 1164 } 1165 1166 if (rt) 1167 rtfree(rt); 1168 1169 /* 1170 * Notify protocols that the MTU for this destination 1171 * has changed. 1172 */ 1173 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 1174 mc = LIST_NEXT(mc, mc_list)) 1175 (*mc->mc_func)(faddr); 1176 } 1177 1178 /* 1179 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1180 * given current value MTU. If DIR is less than zero, a larger plateau 1181 * is returned; otherwise, a smaller value is returned. 1182 */ 1183 u_int 1184 ip_next_mtu(u_int mtu, int dir) /* XXX */ 1185 { 1186 int i; 1187 1188 for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) { 1189 if (mtu >= mtu_table[i]) 1190 break; 1191 } 1192 1193 if (dir < 0) { 1194 if (i == 0) { 1195 return 0; 1196 } else { 1197 return mtu_table[i - 1]; 1198 } 1199 } else { 1200 if (mtu_table[i] == 0) { 1201 return 0; 1202 } else if (mtu > mtu_table[i]) { 1203 return mtu_table[i]; 1204 } else { 1205 return mtu_table[i + 1]; 1206 } 1207 } 1208 } 1209 1210 static void 1211 icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) 1212 { 1213 if (rt == NULL) 1214 panic("icmp_mtudisc_timeout: bad route to timeout"); 1215 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1216 (RTF_DYNAMIC | RTF_HOST)) { 1217 rtrequest((int) RTM_DELETE, rt_getkey(rt), 1218 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1219 } else { 1220 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1221 rt->rt_rmx.rmx_mtu = 0; 1222 } 1223 } 1224 } 1225 1226 static void 1227 icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r) 1228 { 1229 if (rt == NULL) 1230 panic("icmp_redirect_timeout: bad route to timeout"); 1231 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1232 (RTF_DYNAMIC | RTF_HOST)) { 1233 rtrequest((int) RTM_DELETE, rt_getkey(rt), 1234 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1235 } 1236 } 1237 1238 /* 1239 * Perform rate limit check. 1240 * Returns 0 if it is okay to send the icmp packet. 1241 * Returns 1 if the router SHOULD NOT send this icmp packet due to rate 1242 * limitation. 1243 * 1244 * XXX per-destination/type check necessary? 1245 */ 1246 int 1247 icmp_ratelimit(const struct in_addr *dst, const int type, 1248 const int code) 1249 { 1250 1251 /* PPS limit */ 1252 if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count, 1253 icmperrppslim)) { 1254 /* The packet is subject to rate limit */ 1255 return 1; 1256 } 1257 1258 /* okay to send */ 1259 return 0; 1260 } 1261