ip_icmp.c revision 1.138
1 /* $NetBSD: ip_icmp.c,v 1.138 2015/05/02 14:41:32 roy 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 1.138 2015/05/02 14:41:32 roy Exp $"); 98 99 #include "opt_ipsec.h" 100 101 #include <sys/param.h> 102 #include <sys/systm.h> 103 #include <sys/mbuf.h> 104 #include <sys/protosw.h> 105 #include <sys/socket.h> 106 #include <sys/kmem.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 = kmem_alloc(sizeof(*mc), KM_SLEEP); 208 mc->mc_func = func; 209 LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, mc, mc_list); 210 } 211 212 /* 213 * Generate an error packet of type error 214 * in response to bad packet ip. 215 */ 216 void 217 icmp_error(struct mbuf *n, int type, int code, n_long dest, 218 int destmtu) 219 { 220 struct ip *oip = mtod(n, struct ip *), *nip; 221 unsigned oiplen = oip->ip_hl << 2; 222 struct icmp *icp; 223 struct mbuf *m; 224 struct m_tag *mtag; 225 unsigned icmplen, mblen; 226 227 #ifdef ICMPPRINTFS 228 if (icmpprintfs) 229 printf("icmp_error(%p, type:%d, code:%d)\n", oip, type, code); 230 #endif 231 if (type != ICMP_REDIRECT) 232 ICMP_STATINC(ICMP_STAT_ERROR); 233 /* 234 * Don't send error if the original packet was encrypted. 235 * Don't send error if not the first fragment of message. 236 * Don't error if the old packet protocol was ICMP 237 * error message, only known informational types. 238 */ 239 if (n->m_flags & M_DECRYPTED) 240 goto freeit; 241 if (oip->ip_off &~ htons(IP_MF|IP_DF)) 242 goto freeit; 243 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 244 n->m_len >= oiplen + ICMP_MINLEN && 245 !ICMP_INFOTYPE(((struct icmp *)((char *)oip + oiplen))->icmp_type)) { 246 ICMP_STATINC(ICMP_STAT_OLDICMP); 247 goto freeit; 248 } 249 /* Don't send error in response to a multicast or broadcast packet */ 250 if (n->m_flags & (M_BCAST|M_MCAST)) 251 goto freeit; 252 253 /* 254 * First, do a rate limitation check. 255 */ 256 if (icmp_ratelimit(&oip->ip_src, type, code)) { 257 /* XXX stat */ 258 goto freeit; 259 } 260 261 /* 262 * Now, formulate icmp message 263 */ 264 icmplen = oiplen + min(icmpreturndatabytes, 265 ntohs(oip->ip_len) - oiplen); 266 /* 267 * Defend against mbuf chains shorter than oip->ip_len - oiplen: 268 */ 269 mblen = 0; 270 for (m = n; m && (mblen < icmplen); m = m->m_next) 271 mblen += m->m_len; 272 icmplen = min(mblen, icmplen); 273 274 /* 275 * As we are not required to return everything we have, 276 * we return whatever we can return at ease. 277 * 278 * Note that ICMP datagrams longer than 576 octets are out of spec 279 * according to RFC1812; the limit on icmpreturndatabytes below in 280 * icmp_sysctl will keep things below that limit. 281 */ 282 283 KASSERT(ICMP_MINLEN <= MCLBYTES); 284 285 if (icmplen + ICMP_MINLEN > MCLBYTES) 286 icmplen = MCLBYTES - ICMP_MINLEN; 287 288 m = m_gethdr(M_DONTWAIT, MT_HEADER); 289 if (m && (icmplen + ICMP_MINLEN > MHLEN)) { 290 MCLGET(m, M_DONTWAIT); 291 if ((m->m_flags & M_EXT) == 0) { 292 m_freem(m); 293 m = NULL; 294 } 295 } 296 if (m == NULL) 297 goto freeit; 298 MCLAIM(m, n->m_owner); 299 m->m_len = icmplen + ICMP_MINLEN; 300 if ((m->m_flags & M_EXT) == 0) 301 MH_ALIGN(m, m->m_len); 302 else { 303 m->m_data += sizeof(struct ip); 304 m->m_len -= sizeof(struct ip); 305 } 306 icp = mtod(m, struct icmp *); 307 if ((u_int)type > ICMP_MAXTYPE) 308 panic("icmp_error"); 309 ICMP_STATINC(ICMP_STAT_OUTHIST + type); 310 icp->icmp_type = type; 311 if (type == ICMP_REDIRECT) 312 icp->icmp_gwaddr.s_addr = dest; 313 else { 314 icp->icmp_void = 0; 315 /* 316 * The following assignments assume an overlay with the 317 * zeroed icmp_void field. 318 */ 319 if (type == ICMP_PARAMPROB) { 320 icp->icmp_pptr = code; 321 code = 0; 322 } else if (type == ICMP_UNREACH && 323 code == ICMP_UNREACH_NEEDFRAG && destmtu) 324 icp->icmp_nextmtu = htons(destmtu); 325 } 326 327 icp->icmp_code = code; 328 m_copydata(n, 0, icmplen, (void *)&icp->icmp_ip); 329 330 /* 331 * Now, copy old ip header (without options) 332 * in front of icmp message. 333 */ 334 if ((m->m_flags & M_EXT) == 0 && 335 m->m_data - sizeof(struct ip) < m->m_pktdat) 336 panic("icmp len"); 337 m->m_data -= sizeof(struct ip); 338 m->m_len += sizeof(struct ip); 339 m->m_pkthdr.len = m->m_len; 340 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif; 341 nip = mtod(m, struct ip *); 342 /* ip_v set in ip_output */ 343 nip->ip_hl = sizeof(struct ip) >> 2; 344 nip->ip_tos = 0; 345 nip->ip_len = htons(m->m_len); 346 /* ip_id set in ip_output */ 347 nip->ip_off = htons(0); 348 /* ip_ttl set in icmp_reflect */ 349 nip->ip_p = IPPROTO_ICMP; 350 nip->ip_src = oip->ip_src; 351 nip->ip_dst = oip->ip_dst; 352 /* move PF m_tag to new packet, if it exists */ 353 mtag = m_tag_find(n, PACKET_TAG_PF, NULL); 354 if (mtag != NULL) { 355 m_tag_unlink(n, mtag); 356 m_tag_prepend(m, mtag); 357 } 358 icmp_reflect(m); 359 360 freeit: 361 m_freem(n); 362 } 363 364 struct sockaddr_in icmpsrc = { 365 .sin_len = sizeof (struct sockaddr_in), 366 .sin_family = AF_INET, 367 }; 368 static struct sockaddr_in icmpdst = { 369 .sin_len = sizeof (struct sockaddr_in), 370 .sin_family = AF_INET, 371 }; 372 static struct sockaddr_in icmpgw = { 373 .sin_len = sizeof (struct sockaddr_in), 374 .sin_family = AF_INET, 375 }; 376 struct sockaddr_in icmpmask = { 377 .sin_len = 8, 378 .sin_family = 0, 379 }; 380 381 /* 382 * Process a received ICMP message. 383 */ 384 void 385 icmp_input(struct mbuf *m, ...) 386 { 387 int proto; 388 struct icmp *icp; 389 struct ip *ip = mtod(m, struct ip *); 390 int icmplen; 391 int i; 392 struct in_ifaddr *ia; 393 void *(*ctlfunc)(int, const struct sockaddr *, void *); 394 int code; 395 int hlen; 396 va_list ap; 397 struct rtentry *rt; 398 399 va_start(ap, m); 400 hlen = va_arg(ap, int); 401 proto = va_arg(ap, int); 402 va_end(ap); 403 404 /* 405 * Locate icmp structure in mbuf, and check 406 * that not corrupted and of at least minimum length. 407 */ 408 icmplen = ntohs(ip->ip_len) - hlen; 409 #ifdef ICMPPRINTFS 410 if (icmpprintfs) { 411 char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; 412 printf("icmp_input from `%s' to `%s', len %d\n", 413 IN_PRINT(sbuf, &ip->ip_src), IN_PRINT(dbuf, &ip->ip_dst), 414 icmplen); 415 } 416 #endif 417 if (icmplen < ICMP_MINLEN) { 418 ICMP_STATINC(ICMP_STAT_TOOSHORT); 419 goto freeit; 420 } 421 i = hlen + min(icmplen, ICMP_ADVLENMIN); 422 if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == NULL) { 423 ICMP_STATINC(ICMP_STAT_TOOSHORT); 424 return; 425 } 426 ip = mtod(m, struct ip *); 427 m->m_len -= hlen; 428 m->m_data += hlen; 429 icp = mtod(m, struct icmp *); 430 /* Don't need to assert alignment, here. */ 431 if (in_cksum(m, icmplen)) { 432 ICMP_STATINC(ICMP_STAT_CHECKSUM); 433 goto freeit; 434 } 435 m->m_len += hlen; 436 m->m_data -= hlen; 437 438 #ifdef ICMPPRINTFS 439 /* 440 * Message type specific processing. 441 */ 442 if (icmpprintfs) 443 printf("icmp_input(type:%d, code:%d)\n", icp->icmp_type, 444 icp->icmp_code); 445 #endif 446 if (icp->icmp_type > ICMP_MAXTYPE) 447 goto raw; 448 ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type); 449 code = icp->icmp_code; 450 switch (icp->icmp_type) { 451 452 case ICMP_UNREACH: 453 switch (code) { 454 case ICMP_UNREACH_PROTOCOL: 455 code = PRC_UNREACH_PROTOCOL; 456 break; 457 458 case ICMP_UNREACH_PORT: 459 code = PRC_UNREACH_PORT; 460 break; 461 462 case ICMP_UNREACH_SRCFAIL: 463 code = PRC_UNREACH_SRCFAIL; 464 break; 465 466 case ICMP_UNREACH_NEEDFRAG: 467 code = PRC_MSGSIZE; 468 break; 469 470 case ICMP_UNREACH_NET: 471 case ICMP_UNREACH_NET_UNKNOWN: 472 case ICMP_UNREACH_NET_PROHIB: 473 case ICMP_UNREACH_TOSNET: 474 code = PRC_UNREACH_NET; 475 break; 476 477 case ICMP_UNREACH_HOST: 478 case ICMP_UNREACH_HOST_UNKNOWN: 479 case ICMP_UNREACH_ISOLATED: 480 case ICMP_UNREACH_HOST_PROHIB: 481 case ICMP_UNREACH_TOSHOST: 482 case ICMP_UNREACH_ADMIN_PROHIBIT: 483 case ICMP_UNREACH_HOST_PREC: 484 case ICMP_UNREACH_PREC_CUTOFF: 485 code = PRC_UNREACH_HOST; 486 break; 487 488 default: 489 goto badcode; 490 } 491 goto deliver; 492 493 case ICMP_TIMXCEED: 494 if (code > 1) 495 goto badcode; 496 code += PRC_TIMXCEED_INTRANS; 497 goto deliver; 498 499 case ICMP_PARAMPROB: 500 if (code > 1) 501 goto badcode; 502 code = PRC_PARAMPROB; 503 goto deliver; 504 505 case ICMP_SOURCEQUENCH: 506 if (code) 507 goto badcode; 508 code = PRC_QUENCH; 509 goto deliver; 510 511 deliver: 512 /* 513 * Problem with datagram; advise higher level routines. 514 */ 515 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 516 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 517 ICMP_STATINC(ICMP_STAT_BADLEN); 518 goto freeit; 519 } 520 if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) 521 goto badcode; 522 #ifdef ICMPPRINTFS 523 if (icmpprintfs) 524 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 525 #endif 526 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 527 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; 528 if (ctlfunc) 529 (void) (*ctlfunc)(code, sintosa(&icmpsrc), 530 &icp->icmp_ip); 531 break; 532 533 badcode: 534 ICMP_STATINC(ICMP_STAT_BADCODE); 535 break; 536 537 case ICMP_ECHO: 538 if (!icmpbmcastecho && 539 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 540 ICMP_STATINC(ICMP_STAT_BMCASTECHO); 541 break; 542 } 543 icp->icmp_type = ICMP_ECHOREPLY; 544 goto reflect; 545 546 case ICMP_TSTAMP: 547 if (icmplen < ICMP_TSLEN) { 548 ICMP_STATINC(ICMP_STAT_BADLEN); 549 break; 550 } 551 if (!icmpbmcastecho && 552 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 553 ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); 554 break; 555 } 556 icp->icmp_type = ICMP_TSTAMPREPLY; 557 icp->icmp_rtime = iptime(); 558 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 559 goto reflect; 560 561 case ICMP_MASKREQ: 562 if (icmpmaskrepl == 0) 563 break; 564 /* 565 * We are not able to respond with all ones broadcast 566 * unless we receive it over a point-to-point interface. 567 */ 568 if (icmplen < ICMP_MASKLEN) { 569 ICMP_STATINC(ICMP_STAT_BADLEN); 570 break; 571 } 572 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 573 in_nullhost(ip->ip_dst)) 574 icmpdst.sin_addr = ip->ip_src; 575 else 576 icmpdst.sin_addr = ip->ip_dst; 577 ia = ifatoia(ifaof_ifpforaddr(sintosa(&icmpdst), 578 m->m_pkthdr.rcvif)); 579 if (ia == 0) 580 break; 581 icp->icmp_type = ICMP_MASKREPLY; 582 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 583 if (in_nullhost(ip->ip_src)) { 584 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 585 ip->ip_src = ia->ia_broadaddr.sin_addr; 586 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 587 ip->ip_src = ia->ia_dstaddr.sin_addr; 588 } 589 reflect: 590 { 591 uint64_t *icps = percpu_getref(icmpstat_percpu); 592 icps[ICMP_STAT_REFLECT]++; 593 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; 594 percpu_putref(icmpstat_percpu); 595 } 596 icmp_reflect(m); 597 return; 598 599 case ICMP_REDIRECT: 600 if (code > 3) 601 goto badcode; 602 if (icmp_rediraccept == 0) 603 goto freeit; 604 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 605 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 606 ICMP_STATINC(ICMP_STAT_BADLEN); 607 break; 608 } 609 /* 610 * Short circuit routing redirects to force 611 * immediate change in the kernel's routing 612 * tables. The message is also handed to anyone 613 * listening on a raw socket (e.g. the routing 614 * daemon for use in updating its tables). 615 */ 616 icmpgw.sin_addr = ip->ip_src; 617 icmpdst.sin_addr = icp->icmp_gwaddr; 618 #ifdef ICMPPRINTFS 619 if (icmpprintfs) { 620 char gbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; 621 printf("redirect dst `%s' to `%s'\n", 622 IN_PRINT(dbuf, &icp->icmp_ip.ip_dst), 623 IN_PRINT(gbuf, &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 char buf[INET_ADDRSTRLEN]; 635 log(LOG_ERR, "ICMP: redirect failed to " 636 "register timeout for route to %s, " 637 "code %d\n", 638 IN_PRINT(buf, &icp->icmp_ip.ip_dst), i); 639 } 640 } 641 if (rt != NULL) 642 rtfree(rt); 643 644 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); 645 #if defined(IPSEC) 646 if (ipsec_used) 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 = NULL; 684 struct in_addr t; 685 struct mbuf *opts = NULL; 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 if (ia->ia4_flags & IN_IFF_NOTREADY) 707 ia = NULL; 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 if ((ia->ia4_flags & IN_IFF_NOTREADY) == 0) 718 break; 719 ia = NULL; 720 } 721 } 722 } 723 724 if (ia) 725 sin = &ia->ia_addr; 726 727 icmpdst.sin_addr = t; 728 729 /* 730 * if the packet is addressed somewhere else, compute the 731 * source address for packets routed back to the source, and 732 * use that, if it's an address on the interface which 733 * received the packet 734 */ 735 if (sin == NULL && m->m_pkthdr.rcvif) { 736 struct sockaddr_in sin_dst; 737 struct route icmproute; 738 int errornum; 739 740 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); 741 memset(&icmproute, 0, sizeof(icmproute)); 742 errornum = 0; 743 sin = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum); 744 /* errornum is never used */ 745 rtcache_free(&icmproute); 746 /* check to make sure sin is a source address on rcvif */ 747 if (sin) { 748 t = sin->sin_addr; 749 sin = NULL; 750 INADDR_TO_IA(t, ia); 751 while (ia) { 752 if (ia->ia_ifp == m->m_pkthdr.rcvif) { 753 sin = &ia->ia_addr; 754 break; 755 } 756 NEXT_IA_WITH_SAME_ADDR(ia); 757 } 758 } 759 } 760 761 /* 762 * if it was not addressed to us, but the route doesn't go out 763 * the source interface, pick an address on the source 764 * interface. This can happen when routing is asymmetric, or 765 * when the incoming packet was encapsulated 766 */ 767 if (sin == NULL && m->m_pkthdr.rcvif) { 768 IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) { 769 if (ifa->ifa_addr->sa_family != AF_INET) 770 continue; 771 sin = &(ifatoia(ifa)->ia_addr); 772 break; 773 } 774 } 775 776 /* 777 * The following happens if the packet was not addressed to us, 778 * and was received on an interface with no IP address: 779 * We find the first AF_INET address on the first non-loopback 780 * interface. 781 */ 782 if (sin == NULL) 783 TAILQ_FOREACH(ia, &in_ifaddrhead, ia_list) { 784 if (ia->ia_ifp->if_flags & IFF_LOOPBACK) 785 continue; 786 sin = &ia->ia_addr; 787 break; 788 } 789 790 /* 791 * If we still didn't find an address, punt. We could have an 792 * interface up (and receiving packets) with no address. 793 */ 794 if (sin == NULL) { 795 m_freem(m); 796 goto done; 797 } 798 799 ip->ip_src = sin->sin_addr; 800 ip->ip_ttl = MAXTTL; 801 802 if (optlen > 0) { 803 u_char *cp; 804 int opt, cnt; 805 u_int len; 806 807 /* 808 * Retrieve any source routing from the incoming packet; 809 * add on any record-route or timestamp options. 810 */ 811 cp = (u_char *) (ip + 1); 812 if ((opts = ip_srcroute()) == NULL && 813 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { 814 MCLAIM(opts, m->m_owner); 815 opts->m_len = sizeof(struct in_addr); 816 *mtod(opts, struct in_addr *) = zeroin_addr; 817 } 818 if (opts) { 819 #ifdef ICMPPRINTFS 820 if (icmpprintfs) 821 printf("icmp_reflect optlen %d rt %d => ", 822 optlen, opts->m_len); 823 #endif 824 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 825 opt = cp[IPOPT_OPTVAL]; 826 if (opt == IPOPT_EOL) 827 break; 828 if (opt == IPOPT_NOP) 829 len = 1; 830 else { 831 if (cnt < IPOPT_OLEN + sizeof(*cp)) 832 break; 833 len = cp[IPOPT_OLEN]; 834 if (len < IPOPT_OLEN + sizeof(*cp) || 835 len > cnt) 836 break; 837 } 838 /* 839 * Should check for overflow, but it "can't happen" 840 */ 841 if (opt == IPOPT_RR || opt == IPOPT_TS || 842 opt == IPOPT_SECURITY) { 843 memmove(mtod(opts, char *) + opts->m_len, 844 cp, len); 845 opts->m_len += len; 846 } 847 } 848 /* Terminate & pad, if necessary */ 849 if ((cnt = opts->m_len % 4) != 0) { 850 for (; cnt < 4; cnt++) { 851 *(mtod(opts, char *) + opts->m_len) = 852 IPOPT_EOL; 853 opts->m_len++; 854 } 855 } 856 #ifdef ICMPPRINTFS 857 if (icmpprintfs) 858 printf("%d\n", opts->m_len); 859 #endif 860 } 861 /* 862 * Now strip out original options by copying rest of first 863 * mbuf's data back, and adjust the IP length. 864 */ 865 ip->ip_len = htons(ntohs(ip->ip_len) - optlen); 866 ip->ip_hl = sizeof(struct ip) >> 2; 867 m->m_len -= optlen; 868 if (m->m_flags & M_PKTHDR) 869 m->m_pkthdr.len -= optlen; 870 optlen += sizeof(struct ip); 871 memmove(ip + 1, (char *)ip + optlen, 872 (unsigned)(m->m_len - sizeof(struct ip))); 873 } 874 m_tag_delete_nonpersistent(m); 875 m->m_flags &= ~(M_BCAST|M_MCAST); 876 877 /* 878 * Clear any in-bound checksum flags for this packet. 879 */ 880 if (m->m_flags & M_PKTHDR) 881 m->m_pkthdr.csum_flags = 0; 882 883 icmp_send(m, opts); 884 done: 885 if (opts) 886 (void)m_free(opts); 887 } 888 889 /* 890 * Send an icmp packet back to the ip level, 891 * after supplying a checksum. 892 */ 893 void 894 icmp_send(struct mbuf *m, struct mbuf *opts) 895 { 896 struct ip *ip = mtod(m, struct ip *); 897 int hlen; 898 struct icmp *icp; 899 900 hlen = ip->ip_hl << 2; 901 m->m_data += hlen; 902 m->m_len -= hlen; 903 icp = mtod(m, struct icmp *); 904 icp->icmp_cksum = 0; 905 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 906 m->m_data -= hlen; 907 m->m_len += hlen; 908 #ifdef ICMPPRINTFS 909 if (icmpprintfs) { 910 char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; 911 printf("icmp_send to destination `%s' from `%s'\n", 912 IN_PRINT(dbuf, &ip->ip_dst), IN_PRINT(sbuf, &ip->ip_src)); 913 } 914 #endif 915 (void)ip_output(m, opts, NULL, 0, NULL, NULL); 916 } 917 918 n_time 919 iptime(void) 920 { 921 struct timeval atv; 922 u_long t; 923 924 microtime(&atv); 925 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 926 return (htonl(t)); 927 } 928 929 /* 930 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures 931 * that the new value is in the correct range. 932 */ 933 static int 934 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) 935 { 936 int error, t; 937 struct sysctlnode node; 938 939 node = *rnode; 940 node.sysctl_data = &t; 941 t = icmpreturndatabytes; 942 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 943 if (error || newp == NULL) 944 return (error); 945 946 if (t < 8 || t > 512) 947 return (EINVAL); 948 icmpreturndatabytes = t; 949 950 return (0); 951 } 952 953 /* 954 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that 955 * the given value is not less than zero and then resets the timeout 956 * queue. 957 */ 958 static int 959 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) 960 { 961 int error, tmp; 962 struct sysctlnode node; 963 964 node = *rnode; 965 node.sysctl_data = &tmp; 966 tmp = icmp_redirtimeout; 967 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 968 if (error || newp == NULL) 969 return (error); 970 if (tmp < 0) 971 return (EINVAL); 972 icmp_redirtimeout = tmp; 973 974 /* 975 * was it a *defined* side-effect that anyone even *reading* 976 * this value causes these things to happen? 977 */ 978 if (icmp_redirect_timeout_q != NULL) { 979 if (icmp_redirtimeout == 0) { 980 rt_timer_queue_destroy(icmp_redirect_timeout_q, 981 true); 982 icmp_redirect_timeout_q = NULL; 983 } else { 984 rt_timer_queue_change(icmp_redirect_timeout_q, 985 icmp_redirtimeout); 986 } 987 } else if (icmp_redirtimeout > 0) { 988 icmp_redirect_timeout_q = 989 rt_timer_queue_create(icmp_redirtimeout); 990 } 991 992 return (0); 993 } 994 995 static int 996 sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) 997 { 998 999 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); 1000 } 1001 1002 static void 1003 sysctl_netinet_icmp_setup(struct sysctllog **clog) 1004 { 1005 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 == NULL) 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 KASSERT(rt != NULL); 1217 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 KASSERT(rt != NULL); 1233 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
Indexes created Fri Sep 26 08:10:20 GMT 2025