ip_icmp.c revision 1.128.2.1
1 /* $NetBSD: ip_icmp.c,v 1.128.2.1 2013/03/31 20:52:29 riz 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 1.128.2.1 2013/03/31 20:52:29 riz 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 KAME_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 /* 137 * ICMP routines: error generation, receive packet processing, and 138 * routines to turnaround packets back to the originator, and 139 * host table maintenance routines. 140 */ 141 142 int icmpmaskrepl = 0; 143 int icmpbmcastecho = 0; 144 #ifdef ICMPPRINTFS 145 int icmpprintfs = 0; 146 #endif 147 int icmpreturndatabytes = 8; 148 149 percpu_t *icmpstat_percpu; 150 151 /* 152 * List of callbacks to notify when Path MTU changes are made. 153 */ 154 struct icmp_mtudisc_callback { 155 LIST_ENTRY(icmp_mtudisc_callback) mc_list; 156 void (*mc_func)(struct in_addr); 157 }; 158 159 LIST_HEAD(, icmp_mtudisc_callback) icmp_mtudisc_callbacks = 160 LIST_HEAD_INITIALIZER(&icmp_mtudisc_callbacks); 161 162 #if 0 163 static u_int ip_next_mtu(u_int, int); 164 #else 165 /*static*/ u_int ip_next_mtu(u_int, int); 166 #endif 167 168 extern int icmperrppslim; 169 static int icmperrpps_count = 0; 170 static struct timeval icmperrppslim_last; 171 static int icmp_rediraccept = 1; 172 static int icmp_redirtimeout = 600; 173 static struct rttimer_queue *icmp_redirect_timeout_q = NULL; 174 175 static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *); 176 static void icmp_redirect_timeout(struct rtentry *, struct rttimer *); 177 178 static void sysctl_netinet_icmp_setup(struct sysctllog **); 179 180 void 181 icmp_init(void) 182 { 183 184 sysctl_netinet_icmp_setup(NULL); 185 186 /* 187 * This is only useful if the user initializes redirtimeout to 188 * something other than zero. 189 */ 190 if (icmp_redirtimeout != 0) { 191 icmp_redirect_timeout_q = 192 rt_timer_queue_create(icmp_redirtimeout); 193 } 194 195 icmpstat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP_NSTATS); 196 } 197 198 /* 199 * Register a Path MTU Discovery callback. 200 */ 201 void 202 icmp_mtudisc_callback_register(void (*func)(struct in_addr)) 203 { 204 struct icmp_mtudisc_callback *mc; 205 206 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 207 mc = LIST_NEXT(mc, mc_list)) { 208 if (mc->mc_func == func) 209 return; 210 } 211 212 mc = malloc(sizeof(*mc), M_PCB, M_NOWAIT); 213 if (mc == NULL) 214 panic("icmp_mtudisc_callback_register"); 215 216 mc->mc_func = func; 217 LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, mc, mc_list); 218 } 219 220 /* 221 * Generate an error packet of type error 222 * in response to bad packet ip. 223 */ 224 void 225 icmp_error(struct mbuf *n, int type, int code, n_long dest, 226 int destmtu) 227 { 228 struct ip *oip = mtod(n, struct ip *), *nip; 229 unsigned oiplen = oip->ip_hl << 2; 230 struct icmp *icp; 231 struct mbuf *m; 232 struct m_tag *mtag; 233 unsigned icmplen, mblen; 234 235 #ifdef ICMPPRINTFS 236 if (icmpprintfs) 237 printf("icmp_error(%p, type:%d, code:%d)\n", oip, type, code); 238 #endif 239 if (type != ICMP_REDIRECT) 240 ICMP_STATINC(ICMP_STAT_ERROR); 241 /* 242 * Don't send error if the original packet was encrypted. 243 * Don't send error if not the first fragment of message. 244 * Don't error if the old packet protocol was ICMP 245 * error message, only known informational types. 246 */ 247 if (n->m_flags & M_DECRYPTED) 248 goto freeit; 249 if (oip->ip_off &~ htons(IP_MF|IP_DF)) 250 goto freeit; 251 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 252 n->m_len >= oiplen + ICMP_MINLEN && 253 !ICMP_INFOTYPE(((struct icmp *)((char *)oip + oiplen))->icmp_type)) { 254 ICMP_STATINC(ICMP_STAT_OLDICMP); 255 goto freeit; 256 } 257 /* Don't send error in response to a multicast or broadcast packet */ 258 if (n->m_flags & (M_BCAST|M_MCAST)) 259 goto freeit; 260 261 /* 262 * First, do a rate limitation check. 263 */ 264 if (icmp_ratelimit(&oip->ip_src, type, code)) { 265 /* XXX stat */ 266 goto freeit; 267 } 268 269 /* 270 * Now, formulate icmp message 271 */ 272 icmplen = oiplen + min(icmpreturndatabytes, 273 ntohs(oip->ip_len) - oiplen); 274 /* 275 * Defend against mbuf chains shorter than oip->ip_len - oiplen: 276 */ 277 mblen = 0; 278 for (m = n; m && (mblen < icmplen); m = m->m_next) 279 mblen += m->m_len; 280 icmplen = min(mblen, icmplen); 281 282 /* 283 * As we are not required to return everything we have, 284 * we return whatever we can return at ease. 285 * 286 * Note that ICMP datagrams longer than 576 octets are out of spec 287 * according to RFC1812; the limit on icmpreturndatabytes below in 288 * icmp_sysctl will keep things below that limit. 289 */ 290 291 KASSERT(ICMP_MINLEN <= MCLBYTES); 292 293 if (icmplen + ICMP_MINLEN > MCLBYTES) 294 icmplen = MCLBYTES - ICMP_MINLEN; 295 296 m = m_gethdr(M_DONTWAIT, MT_HEADER); 297 if (m && (icmplen + ICMP_MINLEN > MHLEN)) { 298 MCLGET(m, M_DONTWAIT); 299 if ((m->m_flags & M_EXT) == 0) { 300 m_freem(m); 301 m = NULL; 302 } 303 } 304 if (m == NULL) 305 goto freeit; 306 MCLAIM(m, n->m_owner); 307 m->m_len = icmplen + ICMP_MINLEN; 308 if ((m->m_flags & M_EXT) == 0) 309 MH_ALIGN(m, m->m_len); 310 else { 311 m->m_data += sizeof(struct ip); 312 m->m_len -= sizeof(struct ip); 313 } 314 icp = mtod(m, struct icmp *); 315 if ((u_int)type > ICMP_MAXTYPE) 316 panic("icmp_error"); 317 ICMP_STATINC(ICMP_STAT_OUTHIST + type); 318 icp->icmp_type = type; 319 if (type == ICMP_REDIRECT) 320 icp->icmp_gwaddr.s_addr = dest; 321 else { 322 icp->icmp_void = 0; 323 /* 324 * The following assignments assume an overlay with the 325 * zeroed icmp_void field. 326 */ 327 if (type == ICMP_PARAMPROB) { 328 icp->icmp_pptr = code; 329 code = 0; 330 } else if (type == ICMP_UNREACH && 331 code == ICMP_UNREACH_NEEDFRAG && destmtu) 332 icp->icmp_nextmtu = htons(destmtu); 333 } 334 335 icp->icmp_code = code; 336 m_copydata(n, 0, icmplen, (void *)&icp->icmp_ip); 337 338 /* 339 * Now, copy old ip header (without options) 340 * in front of icmp message. 341 */ 342 if ((m->m_flags & M_EXT) == 0 && 343 m->m_data - sizeof(struct ip) < m->m_pktdat) 344 panic("icmp len"); 345 m->m_data -= sizeof(struct ip); 346 m->m_len += sizeof(struct ip); 347 m->m_pkthdr.len = m->m_len; 348 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif; 349 nip = mtod(m, struct ip *); 350 /* ip_v set in ip_output */ 351 nip->ip_hl = sizeof(struct ip) >> 2; 352 nip->ip_tos = 0; 353 nip->ip_len = htons(m->m_len); 354 /* ip_id set in ip_output */ 355 nip->ip_off = htons(0); 356 /* ip_ttl set in icmp_reflect */ 357 nip->ip_p = IPPROTO_ICMP; 358 nip->ip_src = oip->ip_src; 359 nip->ip_dst = oip->ip_dst; 360 /* move PF m_tag to new packet, if it exists */ 361 mtag = m_tag_find(n, PACKET_TAG_PF, NULL); 362 if (mtag != NULL) { 363 m_tag_unlink(n, mtag); 364 m_tag_prepend(m, mtag); 365 } 366 icmp_reflect(m); 367 368 freeit: 369 m_freem(n); 370 } 371 372 struct sockaddr_in icmpsrc = { 373 .sin_len = sizeof (struct sockaddr_in), 374 .sin_family = AF_INET, 375 }; 376 static struct sockaddr_in icmpdst = { 377 .sin_len = sizeof (struct sockaddr_in), 378 .sin_family = AF_INET, 379 }; 380 static struct sockaddr_in icmpgw = { 381 .sin_len = sizeof (struct sockaddr_in), 382 .sin_family = AF_INET, 383 }; 384 struct sockaddr_in icmpmask = { 385 .sin_len = 8, 386 .sin_family = 0, 387 }; 388 389 /* 390 * Process a received ICMP message. 391 */ 392 void 393 icmp_input(struct mbuf *m, ...) 394 { 395 int proto; 396 struct icmp *icp; 397 struct ip *ip = mtod(m, struct ip *); 398 int icmplen; 399 int i; 400 struct in_ifaddr *ia; 401 void *(*ctlfunc)(int, const struct sockaddr *, void *); 402 int code; 403 int hlen; 404 va_list ap; 405 struct rtentry *rt; 406 407 va_start(ap, m); 408 hlen = va_arg(ap, int); 409 proto = va_arg(ap, int); 410 va_end(ap); 411 412 /* 413 * Locate icmp structure in mbuf, and check 414 * that not corrupted and of at least minimum length. 415 */ 416 icmplen = ntohs(ip->ip_len) - hlen; 417 #ifdef ICMPPRINTFS 418 if (icmpprintfs) { 419 printf("icmp_input from `%s' to ", inet_ntoa(ip->ip_src)); 420 printf("`%s', len %d\n", inet_ntoa(ip->ip_dst), icmplen); 421 } 422 #endif 423 if (icmplen < ICMP_MINLEN) { 424 ICMP_STATINC(ICMP_STAT_TOOSHORT); 425 goto freeit; 426 } 427 i = hlen + min(icmplen, ICMP_ADVLENMIN); 428 if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == NULL) { 429 ICMP_STATINC(ICMP_STAT_TOOSHORT); 430 return; 431 } 432 ip = mtod(m, struct ip *); 433 m->m_len -= hlen; 434 m->m_data += hlen; 435 icp = mtod(m, struct icmp *); 436 /* Don't need to assert alignment, here. */ 437 if (in_cksum(m, icmplen)) { 438 ICMP_STATINC(ICMP_STAT_CHECKSUM); 439 goto freeit; 440 } 441 m->m_len += hlen; 442 m->m_data -= hlen; 443 444 #ifdef ICMPPRINTFS 445 /* 446 * Message type specific processing. 447 */ 448 if (icmpprintfs) 449 printf("icmp_input(type:%d, code:%d)\n", icp->icmp_type, 450 icp->icmp_code); 451 #endif 452 if (icp->icmp_type > ICMP_MAXTYPE) 453 goto raw; 454 ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type); 455 code = icp->icmp_code; 456 switch (icp->icmp_type) { 457 458 case ICMP_UNREACH: 459 switch (code) { 460 case ICMP_UNREACH_PROTOCOL: 461 code = PRC_UNREACH_PROTOCOL; 462 break; 463 464 case ICMP_UNREACH_PORT: 465 code = PRC_UNREACH_PORT; 466 break; 467 468 case ICMP_UNREACH_SRCFAIL: 469 code = PRC_UNREACH_SRCFAIL; 470 break; 471 472 case ICMP_UNREACH_NEEDFRAG: 473 code = PRC_MSGSIZE; 474 break; 475 476 case ICMP_UNREACH_NET: 477 case ICMP_UNREACH_NET_UNKNOWN: 478 case ICMP_UNREACH_NET_PROHIB: 479 case ICMP_UNREACH_TOSNET: 480 code = PRC_UNREACH_NET; 481 break; 482 483 case ICMP_UNREACH_HOST: 484 case ICMP_UNREACH_HOST_UNKNOWN: 485 case ICMP_UNREACH_ISOLATED: 486 case ICMP_UNREACH_HOST_PROHIB: 487 case ICMP_UNREACH_TOSHOST: 488 case ICMP_UNREACH_ADMIN_PROHIBIT: 489 case ICMP_UNREACH_HOST_PREC: 490 case ICMP_UNREACH_PREC_CUTOFF: 491 code = PRC_UNREACH_HOST; 492 break; 493 494 default: 495 goto badcode; 496 } 497 goto deliver; 498 499 case ICMP_TIMXCEED: 500 if (code > 1) 501 goto badcode; 502 code += PRC_TIMXCEED_INTRANS; 503 goto deliver; 504 505 case ICMP_PARAMPROB: 506 if (code > 1) 507 goto badcode; 508 code = PRC_PARAMPROB; 509 goto deliver; 510 511 case ICMP_SOURCEQUENCH: 512 if (code) 513 goto badcode; 514 code = PRC_QUENCH; 515 goto deliver; 516 517 deliver: 518 /* 519 * Problem with datagram; advise higher level routines. 520 */ 521 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 522 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 523 ICMP_STATINC(ICMP_STAT_BADLEN); 524 goto freeit; 525 } 526 if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) 527 goto badcode; 528 #ifdef ICMPPRINTFS 529 if (icmpprintfs) 530 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 531 #endif 532 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 533 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; 534 if (ctlfunc) 535 (void) (*ctlfunc)(code, sintosa(&icmpsrc), 536 &icp->icmp_ip); 537 break; 538 539 badcode: 540 ICMP_STATINC(ICMP_STAT_BADCODE); 541 break; 542 543 case ICMP_ECHO: 544 if (!icmpbmcastecho && 545 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 546 ICMP_STATINC(ICMP_STAT_BMCASTECHO); 547 break; 548 } 549 icp->icmp_type = ICMP_ECHOREPLY; 550 goto reflect; 551 552 case ICMP_TSTAMP: 553 if (icmplen < ICMP_TSLEN) { 554 ICMP_STATINC(ICMP_STAT_BADLEN); 555 break; 556 } 557 if (!icmpbmcastecho && 558 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 559 ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); 560 break; 561 } 562 icp->icmp_type = ICMP_TSTAMPREPLY; 563 icp->icmp_rtime = iptime(); 564 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 565 goto reflect; 566 567 case ICMP_MASKREQ: 568 if (icmpmaskrepl == 0) 569 break; 570 /* 571 * We are not able to respond with all ones broadcast 572 * unless we receive it over a point-to-point interface. 573 */ 574 if (icmplen < ICMP_MASKLEN) { 575 ICMP_STATINC(ICMP_STAT_BADLEN); 576 break; 577 } 578 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 579 in_nullhost(ip->ip_dst)) 580 icmpdst.sin_addr = ip->ip_src; 581 else 582 icmpdst.sin_addr = ip->ip_dst; 583 ia = ifatoia(ifaof_ifpforaddr(sintosa(&icmpdst), 584 m->m_pkthdr.rcvif)); 585 if (ia == 0) 586 break; 587 icp->icmp_type = ICMP_MASKREPLY; 588 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 589 if (in_nullhost(ip->ip_src)) { 590 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 591 ip->ip_src = ia->ia_broadaddr.sin_addr; 592 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 593 ip->ip_src = ia->ia_dstaddr.sin_addr; 594 } 595 reflect: 596 { 597 uint64_t *icps = percpu_getref(icmpstat_percpu); 598 icps[ICMP_STAT_REFLECT]++; 599 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; 600 percpu_putref(icmpstat_percpu); 601 } 602 icmp_reflect(m); 603 return; 604 605 case ICMP_REDIRECT: 606 if (code > 3) 607 goto badcode; 608 if (icmp_rediraccept == 0) 609 goto freeit; 610 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 611 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 612 ICMP_STATINC(ICMP_STAT_BADLEN); 613 break; 614 } 615 /* 616 * Short circuit routing redirects to force 617 * immediate change in the kernel's routing 618 * tables. The message is also handed to anyone 619 * listening on a raw socket (e.g. the routing 620 * daemon for use in updating its tables). 621 */ 622 icmpgw.sin_addr = ip->ip_src; 623 icmpdst.sin_addr = icp->icmp_gwaddr; 624 #ifdef ICMPPRINTFS 625 if (icmpprintfs) { 626 printf("redirect dst `%s' to `%s'\n", 627 inet_ntoa(icp->icmp_ip.ip_dst), 628 inet_ntoa(icp->icmp_gwaddr)); 629 } 630 #endif 631 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 632 rt = NULL; 633 rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst), 634 NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt); 635 if (rt != NULL && icmp_redirtimeout != 0) { 636 i = rt_timer_add(rt, icmp_redirect_timeout, 637 icmp_redirect_timeout_q); 638 if (i) 639 log(LOG_ERR, "ICMP: redirect failed to " 640 "register timeout for route to %x, " 641 "code %d\n", 642 icp->icmp_ip.ip_dst.s_addr, i); 643 } 644 if (rt != NULL) 645 rtfree(rt); 646 647 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); 648 #if defined(KAME_IPSEC) || defined(FAST_IPSEC) 649 key_sa_routechange((struct sockaddr *)&icmpsrc); 650 #endif 651 break; 652 653 /* 654 * No kernel processing for the following; 655 * just fall through to send to raw listener. 656 */ 657 case ICMP_ECHOREPLY: 658 case ICMP_ROUTERADVERT: 659 case ICMP_ROUTERSOLICIT: 660 case ICMP_TSTAMPREPLY: 661 case ICMP_IREQREPLY: 662 case ICMP_MASKREPLY: 663 default: 664 break; 665 } 666 667 raw: 668 rip_input(m, hlen, proto); 669 return; 670 671 freeit: 672 m_freem(m); 673 return; 674 } 675 676 /* 677 * Reflect the ip packet back to the source 678 */ 679 void 680 icmp_reflect(struct mbuf *m) 681 { 682 struct ip *ip = mtod(m, struct ip *); 683 struct in_ifaddr *ia; 684 struct ifaddr *ifa; 685 struct sockaddr_in *sin = 0; 686 struct in_addr t; 687 struct mbuf *opts = 0; 688 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 689 690 if (!in_canforward(ip->ip_src) && 691 ((ip->ip_src.s_addr & IN_CLASSA_NET) != 692 htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { 693 m_freem(m); /* Bad return address */ 694 goto done; /* ip_output() will check for broadcast */ 695 } 696 t = ip->ip_dst; 697 ip->ip_dst = ip->ip_src; 698 /* 699 * If the incoming packet was addressed directly to us, use 700 * dst as the src for the reply. Otherwise (broadcast or 701 * anonymous), use an address which corresponds to the 702 * incoming interface, with a preference for the address which 703 * corresponds to the route to the destination of the ICMP. 704 */ 705 706 /* Look for packet addressed to us */ 707 INADDR_TO_IA(t, ia); 708 709 /* look for packet sent to broadcast address */ 710 if (ia == NULL && m->m_pkthdr.rcvif && 711 (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST)) { 712 IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) { 713 if (ifa->ifa_addr->sa_family != AF_INET) 714 continue; 715 if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) { 716 ia = ifatoia(ifa); 717 break; 718 } 719 } 720 } 721 722 if (ia) 723 sin = &ia->ia_addr; 724 725 icmpdst.sin_addr = t; 726 727 /* 728 * if the packet is addressed somewhere else, compute the 729 * source address for packets routed back to the source, and 730 * use that, if it's an address on the interface which 731 * received the packet 732 */ 733 if (sin == NULL && m->m_pkthdr.rcvif) { 734 struct sockaddr_in sin_dst; 735 struct route icmproute; 736 int errornum; 737 738 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); 739 memset(&icmproute, 0, sizeof(icmproute)); 740 errornum = 0; 741 sin = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum); 742 /* errornum is never used */ 743 rtcache_free(&icmproute); 744 /* check to make sure sin is a source address on rcvif */ 745 if (sin) { 746 t = sin->sin_addr; 747 sin = NULL; 748 INADDR_TO_IA(t, ia); 749 while (ia) { 750 if (ia->ia_ifp == m->m_pkthdr.rcvif) { 751 sin = &ia->ia_addr; 752 break; 753 } 754 NEXT_IA_WITH_SAME_ADDR(ia); 755 } 756 } 757 } 758 759 /* 760 * if it was not addressed to us, but the route doesn't go out 761 * the source interface, pick an address on the source 762 * interface. This can happen when routing is asymmetric, or 763 * when the incoming packet was encapsulated 764 */ 765 if (sin == NULL && m->m_pkthdr.rcvif) { 766 IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) { 767 if (ifa->ifa_addr->sa_family != AF_INET) 768 continue; 769 sin = &(ifatoia(ifa)->ia_addr); 770 break; 771 } 772 } 773 774 /* 775 * The following happens if the packet was not addressed to us, 776 * and was received on an interface with no IP address: 777 * We find the first AF_INET address on the first non-loopback 778 * interface. 779 */ 780 if (sin == NULL) 781 TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) { 782 if (ia->ia_ifp->if_flags & IFF_LOOPBACK) 783 continue; 784 sin = &ia->ia_addr; 785 break; 786 } 787 788 /* 789 * If we still didn't find an address, punt. We could have an 790 * interface up (and receiving packets) with no address. 791 */ 792 if (sin == NULL) { 793 m_freem(m); 794 goto done; 795 } 796 797 ip->ip_src = sin->sin_addr; 798 ip->ip_ttl = MAXTTL; 799 800 if (optlen > 0) { 801 u_char *cp; 802 int opt, cnt; 803 u_int len; 804 805 /* 806 * Retrieve any source routing from the incoming packet; 807 * add on any record-route or timestamp options. 808 */ 809 cp = (u_char *) (ip + 1); 810 if ((opts = ip_srcroute()) == 0 && 811 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { 812 MCLAIM(opts, m->m_owner); 813 opts->m_len = sizeof(struct in_addr); 814 *mtod(opts, struct in_addr *) = zeroin_addr; 815 } 816 if (opts) { 817 #ifdef ICMPPRINTFS 818 if (icmpprintfs) 819 printf("icmp_reflect optlen %d rt %d => ", 820 optlen, opts->m_len); 821 #endif 822 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 823 opt = cp[IPOPT_OPTVAL]; 824 if (opt == IPOPT_EOL) 825 break; 826 if (opt == IPOPT_NOP) 827 len = 1; 828 else { 829 if (cnt < IPOPT_OLEN + sizeof(*cp)) 830 break; 831 len = cp[IPOPT_OLEN]; 832 if (len < IPOPT_OLEN + sizeof(*cp) || 833 len > cnt) 834 break; 835 } 836 /* 837 * Should check for overflow, but it "can't happen" 838 */ 839 if (opt == IPOPT_RR || opt == IPOPT_TS || 840 opt == IPOPT_SECURITY) { 841 memmove(mtod(opts, char *) + opts->m_len, 842 cp, len); 843 opts->m_len += len; 844 } 845 } 846 /* Terminate & pad, if necessary */ 847 if ((cnt = opts->m_len % 4) != 0) { 848 for (; cnt < 4; cnt++) { 849 *(mtod(opts, char *) + opts->m_len) = 850 IPOPT_EOL; 851 opts->m_len++; 852 } 853 } 854 #ifdef ICMPPRINTFS 855 if (icmpprintfs) 856 printf("%d\n", opts->m_len); 857 #endif 858 } 859 /* 860 * Now strip out original options by copying rest of first 861 * mbuf's data back, and adjust the IP length. 862 */ 863 ip->ip_len = htons(ntohs(ip->ip_len) - optlen); 864 ip->ip_hl = sizeof(struct ip) >> 2; 865 m->m_len -= optlen; 866 if (m->m_flags & M_PKTHDR) 867 m->m_pkthdr.len -= optlen; 868 optlen += sizeof(struct ip); 869 memmove(ip + 1, (char *)ip + optlen, 870 (unsigned)(m->m_len - sizeof(struct ip))); 871 } 872 m_tag_delete_nonpersistent(m); 873 m->m_flags &= ~(M_BCAST|M_MCAST); 874 875 /* 876 * Clear any in-bound checksum flags for this packet. 877 */ 878 if (m->m_flags & M_PKTHDR) 879 m->m_pkthdr.csum_flags = 0; 880 881 icmp_send(m, opts); 882 done: 883 if (opts) 884 (void)m_free(opts); 885 } 886 887 /* 888 * Send an icmp packet back to the ip level, 889 * after supplying a checksum. 890 */ 891 void 892 icmp_send(struct mbuf *m, struct mbuf *opts) 893 { 894 struct ip *ip = mtod(m, struct ip *); 895 int hlen; 896 struct icmp *icp; 897 898 hlen = ip->ip_hl << 2; 899 m->m_data += hlen; 900 m->m_len -= hlen; 901 icp = mtod(m, struct icmp *); 902 icp->icmp_cksum = 0; 903 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 904 m->m_data -= hlen; 905 m->m_len += hlen; 906 #ifdef ICMPPRINTFS 907 if (icmpprintfs) { 908 printf("icmp_send to destination `%s' from `%s'\n", 909 inet_ntoa(ip->ip_dst), inet_ntoa(ip->ip_src)); 910 } 911 #endif 912 (void)ip_output(m, opts, NULL, 0, NULL, NULL); 913 } 914 915 n_time 916 iptime(void) 917 { 918 struct timeval atv; 919 u_long t; 920 921 microtime(&atv); 922 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 923 return (htonl(t)); 924 } 925 926 /* 927 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures 928 * that the new value is in the correct range. 929 */ 930 static int 931 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) 932 { 933 int error, t; 934 struct sysctlnode node; 935 936 node = *rnode; 937 node.sysctl_data = &t; 938 t = icmpreturndatabytes; 939 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 940 if (error || newp == NULL) 941 return (error); 942 943 if (t < 8 || t > 512) 944 return (EINVAL); 945 icmpreturndatabytes = t; 946 947 return (0); 948 } 949 950 /* 951 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that 952 * the given value is not less than zero and then resets the timeout 953 * queue. 954 */ 955 static int 956 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) 957 { 958 int error, tmp; 959 struct sysctlnode node; 960 961 node = *rnode; 962 node.sysctl_data = &tmp; 963 tmp = icmp_redirtimeout; 964 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 965 if (error || newp == NULL) 966 return (error); 967 if (tmp < 0) 968 return (EINVAL); 969 icmp_redirtimeout = tmp; 970 971 /* 972 * was it a *defined* side-effect that anyone even *reading* 973 * this value causes these things to happen? 974 */ 975 if (icmp_redirect_timeout_q != NULL) { 976 if (icmp_redirtimeout == 0) { 977 rt_timer_queue_destroy(icmp_redirect_timeout_q, 978 true); 979 icmp_redirect_timeout_q = NULL; 980 } else { 981 rt_timer_queue_change(icmp_redirect_timeout_q, 982 icmp_redirtimeout); 983 } 984 } else if (icmp_redirtimeout > 0) { 985 icmp_redirect_timeout_q = 986 rt_timer_queue_create(icmp_redirtimeout); 987 } 988 989 return (0); 990 } 991 992 static int 993 sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) 994 { 995 996 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); 997 } 998 999 static void 1000 sysctl_netinet_icmp_setup(struct sysctllog **clog) 1001 { 1002 1003 sysctl_createv(clog, 0, NULL, NULL, 1004 CTLFLAG_PERMANENT, 1005 CTLTYPE_NODE, "net", NULL, 1006 NULL, 0, NULL, 0, 1007 CTL_NET, CTL_EOL); 1008 sysctl_createv(clog, 0, NULL, NULL, 1009 CTLFLAG_PERMANENT, 1010 CTLTYPE_NODE, "inet", NULL, 1011 NULL, 0, NULL, 0, 1012 CTL_NET, PF_INET, CTL_EOL); 1013 sysctl_createv(clog, 0, NULL, NULL, 1014 CTLFLAG_PERMANENT, 1015 CTLTYPE_NODE, "icmp", 1016 SYSCTL_DESCR("ICMPv4 related settings"), 1017 NULL, 0, NULL, 0, 1018 CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL); 1019 1020 sysctl_createv(clog, 0, NULL, NULL, 1021 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1022 CTLTYPE_INT, "maskrepl", 1023 SYSCTL_DESCR("Respond to ICMP_MASKREQ messages"), 1024 NULL, 0, &icmpmaskrepl, 0, 1025 CTL_NET, PF_INET, IPPROTO_ICMP, 1026 ICMPCTL_MASKREPL, CTL_EOL); 1027 sysctl_createv(clog, 0, NULL, NULL, 1028 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1029 CTLTYPE_INT, "returndatabytes", 1030 SYSCTL_DESCR("Number of bytes to return in an ICMP " 1031 "error message"), 1032 sysctl_net_inet_icmp_returndatabytes, 0, 1033 &icmpreturndatabytes, 0, 1034 CTL_NET, PF_INET, IPPROTO_ICMP, 1035 ICMPCTL_RETURNDATABYTES, CTL_EOL); 1036 sysctl_createv(clog, 0, NULL, NULL, 1037 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1038 CTLTYPE_INT, "errppslimit", 1039 SYSCTL_DESCR("Maximum number of outgoing ICMP error " 1040 "messages per second"), 1041 NULL, 0, &icmperrppslim, 0, 1042 CTL_NET, PF_INET, IPPROTO_ICMP, 1043 ICMPCTL_ERRPPSLIMIT, CTL_EOL); 1044 sysctl_createv(clog, 0, NULL, NULL, 1045 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1046 CTLTYPE_INT, "rediraccept", 1047 SYSCTL_DESCR("Accept ICMP_REDIRECT messages"), 1048 NULL, 0, &icmp_rediraccept, 0, 1049 CTL_NET, PF_INET, IPPROTO_ICMP, 1050 ICMPCTL_REDIRACCEPT, CTL_EOL); 1051 sysctl_createv(clog, 0, NULL, NULL, 1052 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1053 CTLTYPE_INT, "redirtimeout", 1054 SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated " 1055 "routes"), 1056 sysctl_net_inet_icmp_redirtimeout, 0, 1057 &icmp_redirtimeout, 0, 1058 CTL_NET, PF_INET, IPPROTO_ICMP, 1059 ICMPCTL_REDIRTIMEOUT, CTL_EOL); 1060 sysctl_createv(clog, 0, NULL, NULL, 1061 CTLFLAG_PERMANENT, 1062 CTLTYPE_STRUCT, "stats", 1063 SYSCTL_DESCR("ICMP statistics"), 1064 sysctl_net_inet_icmp_stats, 0, NULL, 0, 1065 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS, 1066 CTL_EOL); 1067 sysctl_createv(clog, 0, NULL, NULL, 1068 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1069 CTLTYPE_INT, "bmcastecho", 1070 SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP " 1071 "message to the broadcast or multicast"), 1072 NULL, 0, &icmpbmcastecho, 0, 1073 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO, 1074 CTL_EOL); 1075 } 1076 1077 void 1078 icmp_statinc(u_int stat) 1079 { 1080 1081 KASSERT(stat < ICMP_NSTATS); 1082 ICMP_STATINC(stat); 1083 } 1084 1085 /* Table of common MTUs: */ 1086 1087 static const u_int mtu_table[] = { 1088 65535, 65280, 32000, 17914, 9180, 8166, 1089 4352, 2002, 1492, 1006, 508, 296, 68, 0 1090 }; 1091 1092 void 1093 icmp_mtudisc(struct icmp *icp, struct in_addr faddr) 1094 { 1095 struct icmp_mtudisc_callback *mc; 1096 struct sockaddr *dst = sintosa(&icmpsrc); 1097 struct rtentry *rt; 1098 u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */ 1099 int error; 1100 1101 rt = rtalloc1(dst, 1); 1102 if (rt == 0) 1103 return; 1104 1105 /* If we didn't get a host route, allocate one */ 1106 1107 if ((rt->rt_flags & RTF_HOST) == 0) { 1108 struct rtentry *nrt; 1109 1110 error = rtrequest((int) RTM_ADD, dst, 1111 (struct sockaddr *) rt->rt_gateway, NULL, 1112 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); 1113 if (error) { 1114 rtfree(rt); 1115 return; 1116 } 1117 nrt->rt_rmx = rt->rt_rmx; 1118 rtfree(rt); 1119 rt = nrt; 1120 } 1121 error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q); 1122 if (error) { 1123 rtfree(rt); 1124 return; 1125 } 1126 1127 if (mtu == 0) { 1128 int i = 0; 1129 1130 mtu = ntohs(icp->icmp_ip.ip_len); 1131 /* Some 4.2BSD-based routers incorrectly adjust the ip_len */ 1132 if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0) 1133 mtu -= (icp->icmp_ip.ip_hl << 2); 1134 1135 /* If we still can't guess a value, try the route */ 1136 1137 if (mtu == 0) { 1138 mtu = rt->rt_rmx.rmx_mtu; 1139 1140 /* If no route mtu, default to the interface mtu */ 1141 1142 if (mtu == 0) 1143 mtu = rt->rt_ifp->if_mtu; 1144 } 1145 1146 for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++) 1147 if (mtu > mtu_table[i]) { 1148 mtu = mtu_table[i]; 1149 break; 1150 } 1151 } 1152 1153 /* 1154 * XXX: RTV_MTU is overloaded, since the admin can set it 1155 * to turn off PMTU for a route, and the kernel can 1156 * set it to indicate a serious problem with PMTU 1157 * on a route. We should be using a separate flag 1158 * for the kernel to indicate this. 1159 */ 1160 1161 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1162 if (mtu < 296 || mtu > rt->rt_ifp->if_mtu) 1163 rt->rt_rmx.rmx_locks |= RTV_MTU; 1164 else if (rt->rt_rmx.rmx_mtu > mtu || 1165 rt->rt_rmx.rmx_mtu == 0) { 1166 ICMP_STATINC(ICMP_STAT_PMTUCHG); 1167 rt->rt_rmx.rmx_mtu = mtu; 1168 } 1169 } 1170 1171 if (rt) 1172 rtfree(rt); 1173 1174 /* 1175 * Notify protocols that the MTU for this destination 1176 * has changed. 1177 */ 1178 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 1179 mc = LIST_NEXT(mc, mc_list)) 1180 (*mc->mc_func)(faddr); 1181 } 1182 1183 /* 1184 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1185 * given current value MTU. If DIR is less than zero, a larger plateau 1186 * is returned; otherwise, a smaller value is returned. 1187 */ 1188 u_int 1189 ip_next_mtu(u_int mtu, int dir) /* XXX */ 1190 { 1191 int i; 1192 1193 for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) { 1194 if (mtu >= mtu_table[i]) 1195 break; 1196 } 1197 1198 if (dir < 0) { 1199 if (i == 0) { 1200 return 0; 1201 } else { 1202 return mtu_table[i - 1]; 1203 } 1204 } else { 1205 if (mtu_table[i] == 0) { 1206 return 0; 1207 } else if (mtu > mtu_table[i]) { 1208 return mtu_table[i]; 1209 } else { 1210 return mtu_table[i + 1]; 1211 } 1212 } 1213 } 1214 1215 static void 1216 icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) 1217 { 1218 if (rt == NULL) 1219 panic("icmp_mtudisc_timeout: bad route to timeout"); 1220 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1221 (RTF_DYNAMIC | RTF_HOST)) { 1222 rtrequest((int) RTM_DELETE, rt_getkey(rt), 1223 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1224 } else { 1225 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1226 rt->rt_rmx.rmx_mtu = 0; 1227 } 1228 } 1229 } 1230 1231 static void 1232 icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r) 1233 { 1234 if (rt == NULL) 1235 panic("icmp_redirect_timeout: bad route to timeout"); 1236 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1237 (RTF_DYNAMIC | RTF_HOST)) { 1238 rtrequest((int) RTM_DELETE, rt_getkey(rt), 1239 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); 1240 } 1241 } 1242 1243 /* 1244 * Perform rate limit check. 1245 * Returns 0 if it is okay to send the icmp packet. 1246 * Returns 1 if the router SHOULD NOT send this icmp packet due to rate 1247 * limitation. 1248 * 1249 * XXX per-destination/type check necessary? 1250 */ 1251 int 1252 icmp_ratelimit(const struct in_addr *dst, const int type, 1253 const int code) 1254 { 1255 1256 /* PPS limit */ 1257 if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count, 1258 icmperrppslim)) { 1259 /* The packet is subject to rate limit */ 1260 return 1; 1261 } 1262 1263 /* okay to send */ 1264 return 0; 1265 } 1266
Indexes created Fri Oct 03 02:09:57 GMT 2025