1 /* $NetBSD: ip_icmp.c,v 1.180 2025/06/05 06:29:27 ozaki-r Exp $ */ 2 3 /* 4 * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Public Access Networks Corporation ("Panix"). It was developed under 9 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 10 * 11 * This code is derived from software contributed to The NetBSD Foundation 12 * by Jason R. Thorpe of Zembu Labs, Inc. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /* 37 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 38 * All rights reserved. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. Neither the name of the project nor the names of its contributors 49 * may be used to endorse or promote products derived from this software 50 * without specific prior written permission. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62 * 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 1.180 2025/06/05 06:29:27 ozaki-r Exp $"); 98 99 #ifdef _KERNEL_OPT 100 #include "opt_ipsec.h" 101 #endif 102 103 #include <sys/param.h> 104 #include <sys/systm.h> 105 #include <sys/mbuf.h> 106 #include <sys/protosw.h> 107 #include <sys/socket.h> 108 #include <sys/socketvar.h> /* For softnet_lock */ 109 #include <sys/kmem.h> 110 #include <sys/time.h> 111 #include <sys/kernel.h> 112 #include <sys/syslog.h> 113 #include <sys/sysctl.h> 114 115 #include <net/if.h> 116 #include <net/route.h> 117 118 #include <netinet/in.h> 119 #include <netinet/in_systm.h> 120 #include <netinet/in_var.h> 121 #include <netinet/ip.h> 122 #include <netinet/ip_icmp.h> 123 #include <netinet/ip_var.h> 124 #include <netinet/in_pcb.h> 125 #include <netinet/in_proto.h> 126 #include <netinet/icmp_var.h> 127 #include <netinet/icmp_private.h> 128 #include <netinet/wqinput.h> 129 130 #ifdef IPSEC 131 #include <netipsec/ipsec.h> 132 #include <netipsec/key.h> 133 #endif 134 135 /* 136 * ICMP routines: error generation, receive packet processing, and 137 * routines to turnaround packets back to the originator, and 138 * host table maintenance routines. 139 */ 140 141 int icmpmaskrepl = 0; 142 int icmpbmcastecho = 0; 143 int icmpreturndatabytes = 8; 144 145 percpu_t *icmpstat_percpu; 146 147 /* 148 * List of callbacks to notify when Path MTU changes are made. 149 */ 150 struct icmp_mtudisc_callback { 151 LIST_ENTRY(icmp_mtudisc_callback) mc_list; 152 void (*mc_func)(struct in_addr); 153 }; 154 155 LIST_HEAD(, icmp_mtudisc_callback) icmp_mtudisc_callbacks = 156 LIST_HEAD_INITIALIZER(&icmp_mtudisc_callbacks); 157 158 /* unused... */ 159 u_int ip_next_mtu(u_int, int); 160 161 bool icmp_dynamic_rt_msg = false; 162 163 static int icmperrppslim = 100; /* 100pps */ 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 /* Protect mtudisc and redirect stuff */ 171 static kmutex_t icmp_mtx __cacheline_aligned; 172 173 static void icmp_send(struct mbuf *, struct mbuf *); 174 static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *); 175 static void icmp_redirect_timeout(struct rtentry *, struct rttimer *); 176 177 static void sysctl_netinet_icmp_setup(struct sysctllog **); 178 179 /* workqueue-based pr_input */ 180 static struct wqinput *icmp_wqinput; 181 static void _icmp_input(struct mbuf *, int, int); 182 183 void 184 icmp_init(void) 185 { 186 187 sysctl_netinet_icmp_setup(NULL); 188 189 mutex_init(&icmp_mtx, MUTEX_DEFAULT, IPL_NONE); 190 /* 191 * This is only useful if the user initializes redirtimeout to 192 * something other than zero. 193 */ 194 mutex_enter(&icmp_mtx); 195 icmp_redirect_timeout_q = rt_timer_queue_create(icmp_redirtimeout); 196 mutex_exit(&icmp_mtx); 197 198 icmpstat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP_NSTATS); 199 icmp_wqinput = wqinput_create("icmp", _icmp_input); 200 } 201 202 void 203 icmp_mtudisc_lock(void) 204 { 205 206 mutex_enter(&icmp_mtx); 207 } 208 209 void 210 icmp_mtudisc_unlock(void) 211 { 212 213 mutex_exit(&icmp_mtx); 214 } 215 216 /* 217 * Register a Path MTU Discovery callback. 218 */ 219 void 220 icmp_mtudisc_callback_register(void (*func)(struct in_addr)) 221 { 222 struct icmp_mtudisc_callback *mc, *new; 223 224 new = kmem_alloc(sizeof(*mc), KM_SLEEP); 225 226 mutex_enter(&icmp_mtx); 227 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 228 mc = LIST_NEXT(mc, mc_list)) { 229 if (mc->mc_func == func) { 230 mutex_exit(&icmp_mtx); 231 kmem_free(new, sizeof(*mc)); 232 return; 233 } 234 } 235 236 new->mc_func = func; 237 LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, new, mc_list); 238 mutex_exit(&icmp_mtx); 239 } 240 241 /* 242 * Generate an error packet of type error in response to a bad IP packet. 'n' 243 * contains this packet. We create 'm' and send it. 244 * 245 * As we are not required to return everything we have, we return whatever 246 * we can return at ease. 247 * 248 * Note that ICMP datagrams longer than 576 octets are out of spec according 249 * to RFC1812; the limit on icmpreturndatabytes will keep things below that 250 * limit. 251 */ 252 void 253 icmp_error(struct mbuf *n, int type, int code, n_long dest, int destmtu) 254 { 255 struct ip *oip = mtod(n, struct ip *), *nip; 256 const unsigned oiphlen = oip->ip_hl << 2; 257 struct icmp *icp; 258 struct mbuf *m; 259 struct m_tag *mtag; 260 unsigned datalen, mblen; 261 int totlen; 262 263 if (type != ICMP_REDIRECT) 264 ICMP_STATINC(ICMP_STAT_ERROR); 265 266 /* 267 * Don't send error if: 268 * - The original packet was encrypted. 269 * - The packet is multicast or broadcast. 270 * - The packet is not the first fragment of the message. 271 * - The packet is an ICMP message with an unknown type. 272 */ 273 if (n->m_flags & M_DECRYPTED) 274 goto freeit; 275 if (n->m_flags & (M_BCAST|M_MCAST)) 276 goto freeit; 277 if (oip->ip_off &~ htons(IP_MF|IP_DF)) 278 goto freeit; 279 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 280 n->m_len >= oiphlen + ICMP_MINLEN) { 281 struct icmp *oicp = (struct icmp *)((char *)oip + oiphlen); 282 if (!ICMP_INFOTYPE(oicp->icmp_type)) { 283 ICMP_STATINC(ICMP_STAT_OLDICMP); 284 goto freeit; 285 } 286 } 287 288 /* 289 * First, do a rate limitation check. 290 */ 291 if (icmp_ratelimit(&oip->ip_src, type, code)) { 292 /* XXX stat */ 293 goto freeit; 294 } 295 296 /* 297 * Compute the number of bytes we will put in 'icmp_ip'. Truncate 298 * it to the size of the mbuf, if it's too big. 299 */ 300 datalen = oiphlen + uimin(icmpreturndatabytes, 301 ntohs(oip->ip_len) - oiphlen); 302 mblen = 0; 303 for (m = n; m && (mblen < datalen); m = m->m_next) 304 mblen += m->m_len; 305 datalen = uimin(mblen, datalen); 306 307 /* 308 * Compute the total length of the new packet. Truncate it if it's 309 * bigger than the size of a cluster. 310 */ 311 CTASSERT(ICMP_MINLEN + sizeof(struct ip) <= MCLBYTES); 312 totlen = sizeof(struct ip) + ICMP_MINLEN + datalen; 313 if (totlen > MCLBYTES) { 314 datalen = MCLBYTES - ICMP_MINLEN - sizeof(struct ip); 315 totlen = MCLBYTES; 316 } 317 318 /* 319 * Allocate the mbuf for the new packet. 320 */ 321 MGETHDR(m, M_DONTWAIT, MT_HEADER); 322 if (m && (totlen > MHLEN)) { 323 MCLGET(m, M_DONTWAIT); 324 if ((m->m_flags & M_EXT) == 0) { 325 m_freem(m); 326 m = NULL; 327 } 328 } 329 if (m == NULL) 330 goto freeit; 331 MCLAIM(m, n->m_owner); 332 m->m_len = totlen; 333 m->m_pkthdr.len = m->m_len; 334 m_copy_rcvif(m, n); 335 336 if ((u_int)type > ICMP_MAXTYPE) 337 panic("icmp_error"); 338 ICMP_STATINC(ICMP_STAT_OUTHIST + type); 339 340 if ((m->m_flags & M_EXT) == 0) 341 m_align(m, m->m_len); 342 343 /* 344 * Get pointers on the IP header and the ICMP header. 345 */ 346 nip = mtod(m, struct ip *); 347 icp = (struct icmp *)(nip + 1); 348 349 /* 350 * Fill in the fields of the ICMP header: icmp_type, icmp_code 351 * and icmp_ip. icmp_cksum gets filled later. 352 */ 353 icp->icmp_type = type; 354 if (type == ICMP_REDIRECT) { 355 icp->icmp_gwaddr.s_addr = dest; 356 } else { 357 icp->icmp_void = 0; 358 /* 359 * The following assignments assume an overlay with the 360 * zeroed icmp_void field. 361 */ 362 if (type == ICMP_PARAMPROB) { 363 icp->icmp_pptr = code; 364 code = 0; 365 } else if (type == ICMP_UNREACH && 366 code == ICMP_UNREACH_NEEDFRAG && destmtu) 367 icp->icmp_nextmtu = htons(destmtu); 368 } 369 icp->icmp_code = code; 370 m_copydata(n, 0, datalen, (void *)&icp->icmp_ip); 371 372 /* 373 * Now, copy the old IP header (without options) in front of the 374 * ICMP message. The src/dst fields will be swapped in icmp_reflect. 375 */ 376 /* ip_v set in ip_output */ 377 nip->ip_hl = sizeof(struct ip) >> 2; 378 nip->ip_tos = 0; 379 nip->ip_len = htons(m->m_len); 380 /* ip_id set in ip_output */ 381 nip->ip_off = htons(0); 382 /* ip_ttl set in icmp_reflect */ 383 nip->ip_p = IPPROTO_ICMP; 384 nip->ip_src = oip->ip_src; 385 nip->ip_dst = oip->ip_dst; 386 /* move PF m_tag to new packet, if it exists */ 387 mtag = m_tag_find(n, PACKET_TAG_PF); 388 if (mtag != NULL) { 389 m_tag_unlink(n, mtag); 390 m_tag_prepend(m, mtag); 391 } 392 393 icmp_reflect(m); 394 395 freeit: 396 m_freem(n); 397 } 398 399 struct sockaddr_in icmpsrc = { 400 .sin_len = sizeof(struct sockaddr_in), 401 .sin_family = AF_INET, 402 }; 403 404 /* 405 * Process a received ICMP message. 406 */ 407 static void 408 _icmp_input(struct mbuf *m, int hlen, int proto) 409 { 410 struct icmp *icp; 411 struct ip *ip = mtod(m, struct ip *); 412 int icmplen; 413 int i; 414 struct in_ifaddr *ia; 415 void *(*ctlfunc)(int, const struct sockaddr *, void *); 416 int code; 417 struct rtentry *rt; 418 struct sockaddr_in icmpdst = { 419 .sin_len = sizeof(struct sockaddr_in), 420 .sin_family = AF_INET, 421 }; 422 struct sockaddr_in icmpgw = { 423 .sin_len = sizeof(struct sockaddr_in), 424 .sin_family = AF_INET, 425 }; 426 427 /* 428 * Locate icmp structure in mbuf, and check 429 * that not corrupted and of at least minimum length. 430 */ 431 icmplen = ntohs(ip->ip_len) - hlen; 432 if (icmplen < ICMP_MINLEN) { 433 ICMP_STATINC(ICMP_STAT_TOOSHORT); 434 goto freeit; 435 } 436 i = hlen + uimin(icmplen, ICMP_ADVLENMIN); 437 if (M_UNWRITABLE(m, i) && (m = m_pullup(m, i)) == NULL) { 438 ICMP_STATINC(ICMP_STAT_TOOSHORT); 439 return; 440 } 441 ip = mtod(m, struct ip *); 442 m->m_len -= hlen; 443 m->m_data += hlen; 444 icp = mtod(m, struct icmp *); 445 /* Don't need to assert alignment, here. */ 446 if (in_cksum(m, icmplen)) { 447 ICMP_STATINC(ICMP_STAT_CHECKSUM); 448 goto freeit; 449 } 450 m->m_len += hlen; 451 m->m_data -= hlen; 452 453 if (icp->icmp_type > ICMP_MAXTYPE) 454 goto raw; 455 ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type); 456 code = icp->icmp_code; 457 458 switch (icp->icmp_type) { 459 case ICMP_UNREACH: 460 switch (code) { 461 case ICMP_UNREACH_PROTOCOL: 462 code = PRC_UNREACH_PROTOCOL; 463 break; 464 465 case ICMP_UNREACH_PORT: 466 code = PRC_UNREACH_PORT; 467 break; 468 469 case ICMP_UNREACH_SRCFAIL: 470 code = PRC_UNREACH_SRCFAIL; 471 break; 472 473 case ICMP_UNREACH_NEEDFRAG: 474 code = PRC_MSGSIZE; 475 break; 476 477 case ICMP_UNREACH_NET: 478 case ICMP_UNREACH_NET_UNKNOWN: 479 case ICMP_UNREACH_NET_PROHIB: 480 case ICMP_UNREACH_TOSNET: 481 code = PRC_UNREACH_NET; 482 break; 483 484 case ICMP_UNREACH_HOST: 485 case ICMP_UNREACH_HOST_UNKNOWN: 486 case ICMP_UNREACH_ISOLATED: 487 case ICMP_UNREACH_HOST_PROHIB: 488 case ICMP_UNREACH_TOSHOST: 489 case ICMP_UNREACH_ADMIN_PROHIBIT: 490 case ICMP_UNREACH_HOST_PREC: 491 case ICMP_UNREACH_PREC_CUTOFF: 492 code = PRC_UNREACH_HOST; 493 break; 494 495 default: 496 goto badcode; 497 } 498 goto deliver; 499 500 case ICMP_TIMXCEED: 501 if (code > 1) 502 goto badcode; 503 code += PRC_TIMXCEED_INTRANS; 504 goto deliver; 505 506 case ICMP_PARAMPROB: 507 if (code > 1) 508 goto badcode; 509 code = PRC_PARAMPROB; 510 goto deliver; 511 512 case ICMP_SOURCEQUENCH: 513 if (code) 514 goto badcode; 515 code = PRC_QUENCH; 516 goto deliver; 517 518 deliver: 519 /* 520 * Problem with datagram; advise higher level routines. 521 */ 522 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 523 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 524 ICMP_STATINC(ICMP_STAT_BADLEN); 525 goto freeit; 526 } 527 if (m->m_len < hlen + ICMP_ADVLEN(icp)) { 528 m = m_pullup(m, hlen + ICMP_ADVLEN(icp)); 529 if (m == NULL) 530 goto freeit; 531 } 532 ip = mtod(m, struct ip *); 533 icp = (struct icmp *)(mtod(m, uint8_t *) + hlen); 534 535 if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) 536 goto badcode; 537 538 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 539 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; 540 if (ctlfunc) 541 (void) (*ctlfunc)(code, sintosa(&icmpsrc), 542 &icp->icmp_ip); 543 break; 544 545 badcode: 546 ICMP_STATINC(ICMP_STAT_BADCODE); 547 break; 548 549 case ICMP_ECHO: 550 if (!icmpbmcastecho && 551 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 552 ICMP_STATINC(ICMP_STAT_BMCASTECHO); 553 break; 554 } 555 icp->icmp_type = ICMP_ECHOREPLY; 556 goto reflect; 557 558 case ICMP_TSTAMP: 559 if (icmplen < ICMP_TSLEN) { 560 ICMP_STATINC(ICMP_STAT_BADLEN); 561 break; 562 } 563 if (!icmpbmcastecho && 564 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 565 ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); 566 break; 567 } 568 icp->icmp_type = ICMP_TSTAMPREPLY; 569 icp->icmp_rtime = iptime(); 570 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 571 goto reflect; 572 573 case ICMP_MASKREQ: { 574 struct ifnet *rcvif; 575 int s, ss; 576 struct ifaddr *ifa = NULL; 577 578 if (icmpmaskrepl == 0) 579 break; 580 /* 581 * We are not able to respond with all ones broadcast 582 * unless we receive it over a point-to-point interface. 583 */ 584 if (icmplen < ICMP_MASKLEN) { 585 ICMP_STATINC(ICMP_STAT_BADLEN); 586 break; 587 } 588 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 589 in_nullhost(ip->ip_dst)) 590 icmpdst.sin_addr = ip->ip_src; 591 else 592 icmpdst.sin_addr = ip->ip_dst; 593 ss = pserialize_read_enter(); 594 rcvif = m_get_rcvif(m, &s); 595 if (__predict_true(rcvif != NULL)) 596 ifa = ifaof_ifpforaddr(sintosa(&icmpdst), rcvif); 597 m_put_rcvif(rcvif, &s); 598 if (ifa == NULL) { 599 pserialize_read_exit(ss); 600 break; 601 } 602 ia = ifatoia(ifa); 603 icp->icmp_type = ICMP_MASKREPLY; 604 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 605 if (in_nullhost(ip->ip_src)) { 606 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 607 ip->ip_src = ia->ia_broadaddr.sin_addr; 608 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 609 ip->ip_src = ia->ia_dstaddr.sin_addr; 610 } 611 pserialize_read_exit(ss); 612 reflect: 613 { 614 uint64_t *icps = percpu_getref(icmpstat_percpu); 615 icps[ICMP_STAT_REFLECT]++; 616 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; 617 percpu_putref(icmpstat_percpu); 618 } 619 icmp_reflect(m); 620 return; 621 } 622 623 case ICMP_REDIRECT: 624 if (code > 3) 625 goto badcode; 626 if (icmp_rediraccept == 0) 627 goto freeit; 628 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 629 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 630 ICMP_STATINC(ICMP_STAT_BADLEN); 631 break; 632 } 633 /* 634 * Short circuit routing redirects to force 635 * immediate change in the kernel's routing 636 * tables. The message is also handed to anyone 637 * listening on a raw socket (e.g. the routing 638 * daemon for use in updating its tables). 639 */ 640 icmpgw.sin_addr = ip->ip_src; 641 icmpdst.sin_addr = icp->icmp_gwaddr; 642 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 643 rt = NULL; 644 rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst), 645 NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt); 646 mutex_enter(&icmp_mtx); 647 if (rt != NULL && icmp_redirtimeout != 0) { 648 i = rt_timer_add(rt, icmp_redirect_timeout, 649 icmp_redirect_timeout_q); 650 if (i) { 651 char buf[INET_ADDRSTRLEN]; 652 log(LOG_ERR, "ICMP: redirect failed to " 653 "register timeout for route to %s, " 654 "code %d\n", 655 IN_PRINT(buf, &icp->icmp_ip.ip_dst), i); 656 } 657 } 658 mutex_exit(&icmp_mtx); 659 if (rt != NULL) 660 rt_unref(rt); 661 662 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); 663 #if defined(IPSEC) 664 if (ipsec_used) 665 key_sa_routechange((struct sockaddr *)&icmpsrc); 666 #endif 667 break; 668 669 /* 670 * No kernel processing for the following; 671 * just fall through to send to raw listener. 672 */ 673 case ICMP_ECHOREPLY: 674 case ICMP_ROUTERADVERT: 675 case ICMP_ROUTERSOLICIT: 676 case ICMP_TSTAMPREPLY: 677 case ICMP_IREQREPLY: 678 case ICMP_MASKREPLY: 679 default: 680 break; 681 } 682 683 raw: 684 /* 685 * Currently, pim_input() is always called holding softnet_lock 686 * by ipintr()(!NET_MPSAFE) or PR_INPUT_WRAP()(NET_MPSAFE). 687 */ 688 KASSERT(mutex_owned(softnet_lock)); 689 rip_input(m, hlen, proto); 690 return; 691 692 freeit: 693 m_freem(m); 694 return; 695 } 696 697 void 698 icmp_input(struct mbuf *m, int off, int proto) 699 { 700 wqinput_input(icmp_wqinput, m, off, proto); 701 } 702 703 /* 704 * Reflect the ip packet back to the source 705 */ 706 void 707 icmp_reflect(struct mbuf *m) 708 { 709 struct ip *ip = mtod(m, struct ip *); 710 struct in_ifaddr *ia; 711 struct ifaddr *ifa; 712 struct sockaddr_in *sin; 713 struct in_addr t; 714 struct mbuf *opts = NULL; 715 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 716 struct ifnet *rcvif; 717 struct psref psref, psref_ia; 718 int s; 719 int bound; 720 721 bound = curlwp_bind(); 722 723 if (!in_canforward(ip->ip_src) && 724 ((ip->ip_src.s_addr & IN_CLASSA_NET) != 725 htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { 726 m_freem(m); /* Bad return address */ 727 goto done; /* ip_output() will check for broadcast */ 728 } 729 t = ip->ip_dst; 730 ip->ip_dst = ip->ip_src; 731 732 /* 733 * If the incoming packet was addressed directly to us, use 734 * dst as the src for the reply. Otherwise (broadcast or 735 * anonymous), use an address which corresponds to the 736 * incoming interface, with a preference for the address which 737 * corresponds to the route to the destination of the ICMP. 738 */ 739 740 /* Look for packet addressed to us */ 741 ia = in_get_ia_psref(t, &psref_ia); 742 if (ia && (ia->ia4_flags & IN_IFF_NOTREADY)) { 743 ia4_release(ia, &psref_ia); 744 ia = NULL; 745 } 746 747 rcvif = m_get_rcvif_psref(m, &psref); 748 749 /* look for packet sent to broadcast address */ 750 if (ia == NULL && rcvif && 751 (rcvif->if_flags & IFF_BROADCAST)) { 752 s = pserialize_read_enter(); 753 IFADDR_READER_FOREACH(ifa, rcvif) { 754 if (ifa->ifa_addr->sa_family != AF_INET) 755 continue; 756 if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) { 757 ia = ifatoia(ifa); 758 if ((ia->ia4_flags & IN_IFF_NOTREADY) == 0) 759 break; 760 ia = NULL; 761 } 762 } 763 if (ia != NULL) 764 ia4_acquire(ia, &psref_ia); 765 pserialize_read_exit(s); 766 } 767 768 sin = ia ? &ia->ia_addr : NULL; 769 770 /* 771 * if the packet is addressed somewhere else, compute the 772 * source address for packets routed back to the source, and 773 * use that, if it's an address on the interface which 774 * received the packet 775 */ 776 if (sin == NULL && rcvif) { 777 struct sockaddr_in sin_dst; 778 struct route icmproute; 779 int errornum; 780 781 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); 782 memset(&icmproute, 0, sizeof(icmproute)); 783 errornum = 0; 784 ia = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum, 785 &psref_ia); 786 /* errornum is never used */ 787 rtcache_free(&icmproute); 788 /* check to make sure sin is a source address on rcvif */ 789 if (ia != NULL) { 790 sin = &ia->ia_addr; 791 t = sin->sin_addr; 792 sin = NULL; 793 ia4_release(ia, &psref_ia); 794 ia = in_get_ia_on_iface_psref(t, rcvif, &psref_ia); 795 if (ia != NULL) 796 sin = &ia->ia_addr; 797 } 798 } 799 800 /* 801 * if it was not addressed to us, but the route doesn't go out 802 * the source interface, pick an address on the source 803 * interface. This can happen when routing is asymmetric, or 804 * when the incoming packet was encapsulated 805 */ 806 if (sin == NULL && rcvif) { 807 KASSERT(ia == NULL); 808 809 ifa = if_first_addr_psref(rcvif, AF_INET, &psref_ia); 810 if (ifa != NULL) { 811 ia = ifatoia(ifa); 812 sin = &(ia->ia_addr); 813 } 814 } 815 816 m_put_rcvif_psref(rcvif, &psref); 817 818 /* 819 * The following happens if the packet was not addressed to us, 820 * and was received on an interface with no IP address: 821 * We find the first AF_INET address on the first non-loopback 822 * interface. 823 */ 824 if (sin == NULL) { 825 KASSERT(ia == NULL); 826 s = pserialize_read_enter(); 827 IN_ADDRLIST_READER_FOREACH(ia) { 828 if (ia->ia_ifp->if_flags & IFF_LOOPBACK) 829 continue; 830 sin = &ia->ia_addr; 831 ia4_acquire(ia, &psref_ia); 832 break; 833 } 834 pserialize_read_exit(s); 835 } 836 837 /* 838 * If we still didn't find an address, punt. We could have an 839 * interface up (and receiving packets) with no address. 840 */ 841 if (sin == NULL) { 842 KASSERT(ia == NULL); 843 m_freem(m); 844 goto done; 845 } 846 847 ip->ip_src = sin->sin_addr; 848 ip->ip_ttl = MAXTTL; 849 850 if (ia != NULL) 851 ia4_release(ia, &psref_ia); 852 853 if (optlen > 0) { 854 u_char *cp; 855 int opt, cnt; 856 u_int len; 857 858 /* 859 * Retrieve any source routing from the incoming packet; 860 * add on any record-route or timestamp options. 861 */ 862 cp = (u_char *)(ip + 1); 863 if ((opts = ip_srcroute(m)) == NULL && 864 (MGETHDR(opts, M_DONTWAIT, MT_HEADER))) { 865 MCLAIM(opts, m->m_owner); 866 opts->m_len = sizeof(struct in_addr); 867 *mtod(opts, struct in_addr *) = zeroin_addr; 868 } 869 870 if (opts) { 871 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 872 opt = cp[IPOPT_OPTVAL]; 873 if (opt == IPOPT_EOL) 874 break; 875 if (opt == IPOPT_NOP) 876 len = 1; 877 else { 878 if (cnt < IPOPT_OLEN + sizeof(*cp)) 879 break; 880 len = cp[IPOPT_OLEN]; 881 if (len < IPOPT_OLEN + sizeof(*cp) || 882 len > cnt) 883 break; 884 } 885 886 /* Overflows can't happen */ 887 KASSERT(opts->m_len + len <= MHLEN); 888 889 if (opt == IPOPT_RR || opt == IPOPT_TS || 890 opt == IPOPT_SECURITY) { 891 memmove(mtod(opts, char *) + 892 opts->m_len, cp, len); 893 opts->m_len += len; 894 } 895 } 896 897 /* Terminate & pad, if necessary */ 898 if ((cnt = opts->m_len % 4) != 0) { 899 for (; cnt < 4; cnt++) { 900 *(mtod(opts, char *) + opts->m_len) = 901 IPOPT_EOL; 902 opts->m_len++; 903 } 904 } 905 } 906 907 /* 908 * Now strip out original options by copying rest of first 909 * mbuf's data back, and adjust the IP length. 910 */ 911 ip->ip_len = htons(ntohs(ip->ip_len) - optlen); 912 ip->ip_hl = sizeof(struct ip) >> 2; 913 m->m_len -= optlen; 914 if (m->m_flags & M_PKTHDR) 915 m->m_pkthdr.len -= optlen; 916 optlen += sizeof(struct ip); 917 memmove(ip + 1, (char *)ip + optlen, 918 (unsigned)(m->m_len - sizeof(struct ip))); 919 } 920 m_tag_delete_chain(m); 921 m->m_flags &= ~(M_BCAST|M_MCAST); 922 923 /* 924 * Clear any in-bound checksum flags for this packet. 925 */ 926 if (m->m_flags & M_PKTHDR) 927 m->m_pkthdr.csum_flags = 0; 928 929 icmp_send(m, opts); 930 done: 931 curlwp_bindx(bound); 932 if (opts) 933 (void)m_free(opts); 934 } 935 936 /* 937 * Send an icmp packet back to the ip level, 938 * after supplying a checksum. 939 */ 940 static void 941 icmp_send(struct mbuf *m, struct mbuf *opts) 942 { 943 struct ip *ip = mtod(m, struct ip *); 944 int hlen; 945 struct icmp *icp; 946 947 hlen = ip->ip_hl << 2; 948 m->m_data += hlen; 949 m->m_len -= hlen; 950 icp = mtod(m, struct icmp *); 951 icp->icmp_cksum = 0; 952 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 953 m->m_data -= hlen; 954 m->m_len += hlen; 955 956 (void)ip_output(m, opts, NULL, 0, NULL, NULL); 957 } 958 959 n_time 960 iptime(void) 961 { 962 struct timeval atv; 963 u_long t; 964 965 microtime(&atv); 966 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 967 return (htonl(t)); 968 } 969 970 /* 971 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures 972 * that the new value is in the correct range. 973 */ 974 static int 975 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) 976 { 977 int error, t; 978 struct sysctlnode node; 979 980 node = *rnode; 981 node.sysctl_data = &t; 982 t = icmpreturndatabytes; 983 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 984 if (error || newp == NULL) 985 return error; 986 987 if (t < 8 || t > 512) 988 return EINVAL; 989 icmpreturndatabytes = t; 990 991 return 0; 992 } 993 994 /* 995 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that 996 * the given value is not less than zero and then resets the timeout 997 * queue. 998 */ 999 static int 1000 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) 1001 { 1002 int error, tmp; 1003 struct sysctlnode node; 1004 1005 mutex_enter(&icmp_mtx); 1006 1007 node = *rnode; 1008 node.sysctl_data = &tmp; 1009 tmp = icmp_redirtimeout; 1010 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1011 if (error || newp == NULL) 1012 goto out; 1013 if (tmp < 0) { 1014 error = EINVAL; 1015 goto out; 1016 } 1017 icmp_redirtimeout = tmp; 1018 1019 /* 1020 * was it a *defined* side-effect that anyone even *reading* 1021 * this value causes these things to happen? 1022 */ 1023 if (icmp_redirect_timeout_q != NULL) { 1024 if (icmp_redirtimeout == 0) { 1025 rt_timer_queue_destroy(icmp_redirect_timeout_q); 1026 icmp_redirect_timeout_q = NULL; 1027 } else { 1028 rt_timer_queue_change(icmp_redirect_timeout_q, 1029 icmp_redirtimeout); 1030 } 1031 } else if (icmp_redirtimeout > 0) { 1032 icmp_redirect_timeout_q = 1033 rt_timer_queue_create(icmp_redirtimeout); 1034 } 1035 error = 0; 1036 out: 1037 mutex_exit(&icmp_mtx); 1038 return error; 1039 } 1040 1041 static int 1042 sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) 1043 { 1044 1045 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); 1046 } 1047 1048 static void 1049 sysctl_netinet_icmp_setup(struct sysctllog **clog) 1050 { 1051 1052 sysctl_createv(clog, 0, NULL, NULL, 1053 CTLFLAG_PERMANENT, 1054 CTLTYPE_NODE, "inet", NULL, 1055 NULL, 0, NULL, 0, 1056 CTL_NET, PF_INET, CTL_EOL); 1057 sysctl_createv(clog, 0, NULL, NULL, 1058 CTLFLAG_PERMANENT, 1059 CTLTYPE_NODE, "icmp", 1060 SYSCTL_DESCR("ICMPv4 related settings"), 1061 NULL, 0, NULL, 0, 1062 CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL); 1063 1064 sysctl_createv(clog, 0, NULL, NULL, 1065 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1066 CTLTYPE_INT, "maskrepl", 1067 SYSCTL_DESCR("Respond to ICMP_MASKREQ messages"), 1068 NULL, 0, &icmpmaskrepl, 0, 1069 CTL_NET, PF_INET, IPPROTO_ICMP, 1070 ICMPCTL_MASKREPL, CTL_EOL); 1071 sysctl_createv(clog, 0, NULL, NULL, 1072 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1073 CTLTYPE_INT, "returndatabytes", 1074 SYSCTL_DESCR("Number of bytes to return in an ICMP " 1075 "error message"), 1076 sysctl_net_inet_icmp_returndatabytes, 0, 1077 &icmpreturndatabytes, 0, 1078 CTL_NET, PF_INET, IPPROTO_ICMP, 1079 ICMPCTL_RETURNDATABYTES, CTL_EOL); 1080 sysctl_createv(clog, 0, NULL, NULL, 1081 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1082 CTLTYPE_INT, "errppslimit", 1083 SYSCTL_DESCR("Maximum number of outgoing ICMP error " 1084 "messages per second"), 1085 NULL, 0, &icmperrppslim, 0, 1086 CTL_NET, PF_INET, IPPROTO_ICMP, 1087 ICMPCTL_ERRPPSLIMIT, CTL_EOL); 1088 sysctl_createv(clog, 0, NULL, NULL, 1089 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1090 CTLTYPE_INT, "rediraccept", 1091 SYSCTL_DESCR("Accept ICMP_REDIRECT messages"), 1092 NULL, 0, &icmp_rediraccept, 0, 1093 CTL_NET, PF_INET, IPPROTO_ICMP, 1094 ICMPCTL_REDIRACCEPT, CTL_EOL); 1095 sysctl_createv(clog, 0, NULL, NULL, 1096 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1097 CTLTYPE_INT, "redirtimeout", 1098 SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated " 1099 "routes"), 1100 sysctl_net_inet_icmp_redirtimeout, 0, 1101 &icmp_redirtimeout, 0, 1102 CTL_NET, PF_INET, IPPROTO_ICMP, 1103 ICMPCTL_REDIRTIMEOUT, CTL_EOL); 1104 sysctl_createv(clog, 0, NULL, NULL, 1105 CTLFLAG_PERMANENT, 1106 CTLTYPE_STRUCT, "stats", 1107 SYSCTL_DESCR("ICMP statistics"), 1108 sysctl_net_inet_icmp_stats, 0, NULL, 0, 1109 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS, 1110 CTL_EOL); 1111 sysctl_createv(clog, 0, NULL, NULL, 1112 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1113 CTLTYPE_INT, "bmcastecho", 1114 SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP " 1115 "message to the broadcast or multicast"), 1116 NULL, 0, &icmpbmcastecho, 0, 1117 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO, 1118 CTL_EOL); 1119 sysctl_createv(clog, 0, NULL, NULL, 1120 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1121 CTLTYPE_BOOL, "dynamic_rt_msg", 1122 SYSCTL_DESCR("Send routing message for RTF_DYNAMIC"), 1123 NULL, 0, &icmp_dynamic_rt_msg, 0, 1124 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_DYNAMIC_RT_MSG, 1125 CTL_EOL); 1126 } 1127 1128 void 1129 icmp_statinc(u_int stat) 1130 { 1131 1132 KASSERT(stat < ICMP_NSTATS); 1133 ICMP_STATINC(stat); 1134 } 1135 1136 /* Table of common MTUs */ 1137 static const u_int mtu_table[] = { 1138 65535, 65280, 32000, 17914, 9180, 8166, 1139 4352, 2002, 1492, 1006, 508, 296, 68, 0 1140 }; 1141 1142 void 1143 icmp_mtudisc(struct icmp *icp, struct in_addr faddr) 1144 { 1145 struct icmp_mtudisc_callback *mc; 1146 struct sockaddr *dst = sintosa(&icmpsrc); 1147 struct rtentry *rt; 1148 u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */ 1149 int error; 1150 1151 rt = rtalloc1(dst, 1); 1152 if (rt == NULL) 1153 return; 1154 1155 /* If we didn't get a host route, allocate one */ 1156 if ((rt->rt_flags & RTF_HOST) == 0) { 1157 struct rtentry *nrt; 1158 1159 error = rtrequest(RTM_ADD, dst, rt->rt_gateway, NULL, 1160 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); 1161 if (error) { 1162 rt_unref(rt); 1163 return; 1164 } 1165 nrt->rt_rmx = rt->rt_rmx; 1166 rt_newmsg_dynamic(RTM_ADD, nrt); 1167 rt_unref(rt); 1168 rt = nrt; 1169 } 1170 1171 mutex_enter(&icmp_mtx); 1172 error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q); 1173 mutex_exit(&icmp_mtx); 1174 if (error) { 1175 rt_unref(rt); 1176 return; 1177 } 1178 1179 if (mtu == 0) { 1180 int i = 0; 1181 1182 mtu = ntohs(icp->icmp_ip.ip_len); 1183 /* Some 4.2BSD-based routers incorrectly adjust the ip_len */ 1184 if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0) 1185 mtu -= (icp->icmp_ip.ip_hl << 2); 1186 1187 /* If we still can't guess a value, try the route */ 1188 if (mtu == 0) { 1189 mtu = rt->rt_rmx.rmx_mtu; 1190 1191 /* If no route mtu, default to the interface mtu */ 1192 if (mtu == 0) 1193 mtu = rt->rt_ifp->if_mtu; 1194 } 1195 1196 for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++) { 1197 if (mtu > mtu_table[i]) { 1198 mtu = mtu_table[i]; 1199 break; 1200 } 1201 } 1202 } 1203 1204 /* 1205 * XXX: RTV_MTU is overloaded, since the admin can set it 1206 * to turn off PMTU for a route, and the kernel can 1207 * set it to indicate a serious problem with PMTU 1208 * on a route. We should be using a separate flag 1209 * for the kernel to indicate this. 1210 */ 1211 1212 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1213 if (mtu < 296 || mtu > rt->rt_ifp->if_mtu) 1214 rt->rt_rmx.rmx_locks |= RTV_MTU; 1215 else if (rt->rt_rmx.rmx_mtu > mtu || 1216 rt->rt_rmx.rmx_mtu == 0) { 1217 ICMP_STATINC(ICMP_STAT_PMTUCHG); 1218 rt->rt_rmx.rmx_mtu = mtu; 1219 } 1220 } 1221 1222 if (rt != NULL) 1223 rt_unref(rt); 1224 1225 /* 1226 * Notify protocols that the MTU for this destination 1227 * has changed. 1228 */ 1229 mutex_enter(&icmp_mtx); 1230 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 1231 mc = LIST_NEXT(mc, mc_list)) 1232 (*mc->mc_func)(faddr); 1233 mutex_exit(&icmp_mtx); 1234 } 1235 1236 /* 1237 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1238 * given current value MTU. If DIR is less than zero, a larger plateau 1239 * is returned; otherwise, a smaller value is returned. 1240 */ 1241 u_int 1242 ip_next_mtu(u_int mtu, int dir) /* XXX unused */ 1243 { 1244 int i; 1245 1246 for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) { 1247 if (mtu >= mtu_table[i]) 1248 break; 1249 } 1250 1251 if (dir < 0) { 1252 if (i == 0) { 1253 return 0; 1254 } else { 1255 return mtu_table[i - 1]; 1256 } 1257 } else { 1258 if (mtu_table[i] == 0) { 1259 return 0; 1260 } else if (mtu > mtu_table[i]) { 1261 return mtu_table[i]; 1262 } else { 1263 return mtu_table[i + 1]; 1264 } 1265 } 1266 } 1267 1268 static void 1269 icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) 1270 { 1271 struct rtentry *retrt; 1272 1273 KASSERT(rt != NULL); 1274 rt_assert_referenced(rt); 1275 1276 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1277 (RTF_DYNAMIC | RTF_HOST)) { 1278 rtrequest(RTM_DELETE, rt_getkey(rt), 1279 rt->rt_gateway, rt_mask(rt), rt->rt_flags, &retrt); 1280 rt_newmsg_dynamic(RTM_DELETE, retrt); 1281 rt_unref(rt); 1282 rt_free(retrt); 1283 } else { 1284 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1285 rt->rt_rmx.rmx_mtu = 0; 1286 } 1287 } 1288 } 1289 1290 static void 1291 icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r) 1292 { 1293 struct rtentry *retrt; 1294 1295 KASSERT(rt != NULL); 1296 rt_assert_referenced(rt); 1297 1298 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1299 (RTF_DYNAMIC | RTF_HOST)) { 1300 rtrequest(RTM_DELETE, rt_getkey(rt), 1301 rt->rt_gateway, rt_mask(rt), rt->rt_flags, &retrt); 1302 rt_newmsg_dynamic(RTM_DELETE, retrt); 1303 rt_unref(rt); 1304 rt_free(retrt); 1305 } 1306 } 1307 1308 /* 1309 * Perform rate limit check. 1310 * Returns 0 if it is okay to send the icmp packet. 1311 * Returns 1 if the router SHOULD NOT send this icmp packet due to rate 1312 * limitation. 1313 * 1314 * XXX per-destination/type check necessary? 1315 */ 1316 int 1317 icmp_ratelimit(const struct in_addr *dst, const int type, 1318 const int code) 1319 { 1320 1321 /* PPS limit */ 1322 if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count, 1323 icmperrppslim)) { 1324 /* The packet is subject to rate limit */ 1325 return 1; 1326 } 1327 1328 /* okay to send */ 1329 return 0; 1330 } 1331
Indexes created Sat Sep 20 22:09:52 GMT 2025