ip_icmp.c revision 1.168.2.4
1 /* $NetBSD: ip_icmp.c,v 1.168.2.4 2018/09/06 06:56:44 pgoyette 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 1.168.2.4 2018/09/06 06:56:44 pgoyette 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 static int icmperrppslim = 100; /* 100pps */ 162 static int icmperrpps_count = 0; 163 static struct timeval icmperrppslim_last; 164 static int icmp_rediraccept = 1; 165 static int icmp_redirtimeout = 600; 166 static struct rttimer_queue *icmp_redirect_timeout_q = NULL; 167 168 /* Protect mtudisc and redirect stuff */ 169 static kmutex_t icmp_mtx __cacheline_aligned; 170 171 static void icmp_send(struct mbuf *, struct mbuf *); 172 static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *); 173 static void icmp_redirect_timeout(struct rtentry *, struct rttimer *); 174 175 static void sysctl_netinet_icmp_setup(struct sysctllog **); 176 177 /* workqueue-based pr_input */ 178 static struct wqinput *icmp_wqinput; 179 static void _icmp_input(struct mbuf *, int, int); 180 181 void 182 icmp_init(void) 183 { 184 185 sysctl_netinet_icmp_setup(NULL); 186 187 mutex_init(&icmp_mtx, MUTEX_DEFAULT, IPL_NONE); 188 /* 189 * This is only useful if the user initializes redirtimeout to 190 * something other than zero. 191 */ 192 mutex_enter(&icmp_mtx); 193 icmp_redirect_timeout_q = rt_timer_queue_create(icmp_redirtimeout); 194 mutex_exit(&icmp_mtx); 195 196 icmpstat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP_NSTATS); 197 icmp_wqinput = wqinput_create("icmp", _icmp_input); 198 } 199 200 void 201 icmp_mtudisc_lock(void) 202 { 203 204 mutex_enter(&icmp_mtx); 205 } 206 207 void 208 icmp_mtudisc_unlock(void) 209 { 210 211 mutex_exit(&icmp_mtx); 212 } 213 214 /* 215 * Register a Path MTU Discovery callback. 216 */ 217 void 218 icmp_mtudisc_callback_register(void (*func)(struct in_addr)) 219 { 220 struct icmp_mtudisc_callback *mc, *new; 221 222 new = kmem_alloc(sizeof(*mc), KM_SLEEP); 223 224 mutex_enter(&icmp_mtx); 225 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 226 mc = LIST_NEXT(mc, mc_list)) { 227 if (mc->mc_func == func) { 228 mutex_exit(&icmp_mtx); 229 kmem_free(new, sizeof(*mc)); 230 return; 231 } 232 } 233 234 new->mc_func = func; 235 LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, new, mc_list); 236 mutex_exit(&icmp_mtx); 237 } 238 239 /* 240 * Generate an error packet of type error in response to a bad IP packet. 'n' 241 * contains this packet. We create 'm' and send it. 242 * 243 * As we are not required to return everything we have, we return whatever 244 * we can return at ease. 245 * 246 * Note that ICMP datagrams longer than 576 octets are out of spec according 247 * to RFC1812; the limit on icmpreturndatabytes will keep things below that 248 * limit. 249 */ 250 void 251 icmp_error(struct mbuf *n, int type, int code, n_long dest, int destmtu) 252 { 253 struct ip *oip = mtod(n, struct ip *), *nip; 254 const unsigned oiphlen = oip->ip_hl << 2; 255 struct icmp *icp; 256 struct mbuf *m; 257 struct m_tag *mtag; 258 unsigned datalen, mblen; 259 int totlen; 260 261 if (type != ICMP_REDIRECT) 262 ICMP_STATINC(ICMP_STAT_ERROR); 263 264 /* 265 * Don't send error if: 266 * - The original packet was encrypted. 267 * - The packet is multicast or broadcast. 268 * - The packet is not the first fragment of the message. 269 * - The packet is an ICMP message with an unknown type. 270 */ 271 if (n->m_flags & M_DECRYPTED) 272 goto freeit; 273 if (n->m_flags & (M_BCAST|M_MCAST)) 274 goto freeit; 275 if (oip->ip_off &~ htons(IP_MF|IP_DF)) 276 goto freeit; 277 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 278 n->m_len >= oiphlen + ICMP_MINLEN) { 279 struct icmp *oicp = (struct icmp *)((char *)oip + oiphlen); 280 if (!ICMP_INFOTYPE(oicp->icmp_type)) { 281 ICMP_STATINC(ICMP_STAT_OLDICMP); 282 goto freeit; 283 } 284 } 285 286 /* 287 * First, do a rate limitation check. 288 */ 289 if (icmp_ratelimit(&oip->ip_src, type, code)) { 290 /* XXX stat */ 291 goto freeit; 292 } 293 294 /* 295 * Compute the number of bytes we will put in 'icmp_ip'. Truncate 296 * it to the size of the mbuf, if it's too big. 297 */ 298 datalen = oiphlen + uimin(icmpreturndatabytes, 299 ntohs(oip->ip_len) - oiphlen); 300 mblen = 0; 301 for (m = n; m && (mblen < datalen); m = m->m_next) 302 mblen += m->m_len; 303 datalen = uimin(mblen, datalen); 304 305 /* 306 * Compute the total length of the new packet. Truncate it if it's 307 * bigger than the size of a cluster. 308 */ 309 CTASSERT(ICMP_MINLEN + sizeof(struct ip) <= MCLBYTES); 310 totlen = sizeof(struct ip) + ICMP_MINLEN + datalen; 311 if (totlen > MCLBYTES) { 312 datalen = MCLBYTES - ICMP_MINLEN - sizeof(struct ip); 313 totlen = MCLBYTES; 314 } 315 316 /* 317 * Allocate the mbuf for the new packet. 318 */ 319 m = m_gethdr(M_DONTWAIT, MT_HEADER); 320 if (m && (totlen > MHLEN)) { 321 MCLGET(m, M_DONTWAIT); 322 if ((m->m_flags & M_EXT) == 0) { 323 m_freem(m); 324 m = NULL; 325 } 326 } 327 if (m == NULL) 328 goto freeit; 329 MCLAIM(m, n->m_owner); 330 m->m_len = totlen; 331 m->m_pkthdr.len = m->m_len; 332 m_copy_rcvif(m, n); 333 334 if ((u_int)type > ICMP_MAXTYPE) 335 panic("icmp_error"); 336 ICMP_STATINC(ICMP_STAT_OUTHIST + type); 337 338 if ((m->m_flags & M_EXT) == 0) 339 MH_ALIGN(m, m->m_len); 340 341 /* 342 * Get pointers on the IP header and the ICMP header. 343 */ 344 nip = mtod(m, struct ip *); 345 icp = (struct icmp *)(nip + 1); 346 347 /* 348 * Fill in the fields of the ICMP header: icmp_type, icmp_code 349 * and icmp_ip. icmp_cksum gets filled later. 350 */ 351 icp->icmp_type = type; 352 if (type == ICMP_REDIRECT) { 353 icp->icmp_gwaddr.s_addr = dest; 354 } else { 355 icp->icmp_void = 0; 356 /* 357 * The following assignments assume an overlay with the 358 * zeroed icmp_void field. 359 */ 360 if (type == ICMP_PARAMPROB) { 361 icp->icmp_pptr = code; 362 code = 0; 363 } else if (type == ICMP_UNREACH && 364 code == ICMP_UNREACH_NEEDFRAG && destmtu) 365 icp->icmp_nextmtu = htons(destmtu); 366 } 367 icp->icmp_code = code; 368 m_copydata(n, 0, datalen, (void *)&icp->icmp_ip); 369 370 /* 371 * Now, copy the old IP header (without options) in front of the 372 * ICMP message. The src/dst fields will be swapped in icmp_reflect. 373 */ 374 /* ip_v set in ip_output */ 375 nip->ip_hl = sizeof(struct ip) >> 2; 376 nip->ip_tos = 0; 377 nip->ip_len = htons(m->m_len); 378 /* ip_id set in ip_output */ 379 nip->ip_off = htons(0); 380 /* ip_ttl set in icmp_reflect */ 381 nip->ip_p = IPPROTO_ICMP; 382 nip->ip_src = oip->ip_src; 383 nip->ip_dst = oip->ip_dst; 384 /* move PF m_tag to new packet, if it exists */ 385 mtag = m_tag_find(n, PACKET_TAG_PF, NULL); 386 if (mtag != NULL) { 387 m_tag_unlink(n, mtag); 388 m_tag_prepend(m, mtag); 389 } 390 391 icmp_reflect(m); 392 393 freeit: 394 m_freem(n); 395 } 396 397 struct sockaddr_in icmpsrc = { 398 .sin_len = sizeof(struct sockaddr_in), 399 .sin_family = AF_INET, 400 }; 401 402 /* 403 * Process a received ICMP message. 404 */ 405 static void 406 _icmp_input(struct mbuf *m, int hlen, int proto) 407 { 408 struct icmp *icp; 409 struct ip *ip = mtod(m, struct ip *); 410 int icmplen; 411 int i; 412 struct in_ifaddr *ia; 413 void *(*ctlfunc)(int, const struct sockaddr *, void *); 414 int code; 415 struct rtentry *rt; 416 struct sockaddr_in icmpdst = { 417 .sin_len = sizeof(struct sockaddr_in), 418 .sin_family = AF_INET, 419 }; 420 struct sockaddr_in icmpgw = { 421 .sin_len = sizeof(struct sockaddr_in), 422 .sin_family = AF_INET, 423 }; 424 425 /* 426 * Locate icmp structure in mbuf, and check 427 * that not corrupted and of at least minimum length. 428 */ 429 icmplen = ntohs(ip->ip_len) - hlen; 430 if (icmplen < ICMP_MINLEN) { 431 ICMP_STATINC(ICMP_STAT_TOOSHORT); 432 goto freeit; 433 } 434 i = hlen + uimin(icmplen, ICMP_ADVLENMIN); 435 if (M_UNWRITABLE(m, i) && (m = m_pullup(m, i)) == NULL) { 436 ICMP_STATINC(ICMP_STAT_TOOSHORT); 437 return; 438 } 439 ip = mtod(m, struct ip *); 440 m->m_len -= hlen; 441 m->m_data += hlen; 442 icp = mtod(m, struct icmp *); 443 /* Don't need to assert alignment, here. */ 444 if (in_cksum(m, icmplen)) { 445 ICMP_STATINC(ICMP_STAT_CHECKSUM); 446 goto freeit; 447 } 448 m->m_len += hlen; 449 m->m_data -= hlen; 450 451 if (icp->icmp_type > ICMP_MAXTYPE) 452 goto raw; 453 ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type); 454 code = icp->icmp_code; 455 456 switch (icp->icmp_type) { 457 case ICMP_UNREACH: 458 switch (code) { 459 case ICMP_UNREACH_PROTOCOL: 460 code = PRC_UNREACH_PROTOCOL; 461 break; 462 463 case ICMP_UNREACH_PORT: 464 code = PRC_UNREACH_PORT; 465 break; 466 467 case ICMP_UNREACH_SRCFAIL: 468 code = PRC_UNREACH_SRCFAIL; 469 break; 470 471 case ICMP_UNREACH_NEEDFRAG: 472 code = PRC_MSGSIZE; 473 break; 474 475 case ICMP_UNREACH_NET: 476 case ICMP_UNREACH_NET_UNKNOWN: 477 case ICMP_UNREACH_NET_PROHIB: 478 case ICMP_UNREACH_TOSNET: 479 code = PRC_UNREACH_NET; 480 break; 481 482 case ICMP_UNREACH_HOST: 483 case ICMP_UNREACH_HOST_UNKNOWN: 484 case ICMP_UNREACH_ISOLATED: 485 case ICMP_UNREACH_HOST_PROHIB: 486 case ICMP_UNREACH_TOSHOST: 487 case ICMP_UNREACH_ADMIN_PROHIBIT: 488 case ICMP_UNREACH_HOST_PREC: 489 case ICMP_UNREACH_PREC_CUTOFF: 490 code = PRC_UNREACH_HOST; 491 break; 492 493 default: 494 goto badcode; 495 } 496 goto deliver; 497 498 case ICMP_TIMXCEED: 499 if (code > 1) 500 goto badcode; 501 code += PRC_TIMXCEED_INTRANS; 502 goto deliver; 503 504 case ICMP_PARAMPROB: 505 if (code > 1) 506 goto badcode; 507 code = PRC_PARAMPROB; 508 goto deliver; 509 510 case ICMP_SOURCEQUENCH: 511 if (code) 512 goto badcode; 513 code = PRC_QUENCH; 514 goto deliver; 515 516 deliver: 517 /* 518 * Problem with datagram; advise higher level routines. 519 */ 520 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 521 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 522 ICMP_STATINC(ICMP_STAT_BADLEN); 523 goto freeit; 524 } 525 if (m->m_len < hlen + ICMP_ADVLEN(icp)) { 526 m = m_pullup(m, hlen + ICMP_ADVLEN(icp)); 527 if (m == NULL) 528 goto freeit; 529 } 530 ip = mtod(m, struct ip *); 531 icp = (struct icmp *)(mtod(m, uint8_t *) + hlen); 532 533 if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) 534 goto badcode; 535 536 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 537 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; 538 if (ctlfunc) 539 (void) (*ctlfunc)(code, sintosa(&icmpsrc), 540 &icp->icmp_ip); 541 break; 542 543 badcode: 544 ICMP_STATINC(ICMP_STAT_BADCODE); 545 break; 546 547 case ICMP_ECHO: 548 if (!icmpbmcastecho && 549 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 550 ICMP_STATINC(ICMP_STAT_BMCASTECHO); 551 break; 552 } 553 icp->icmp_type = ICMP_ECHOREPLY; 554 goto reflect; 555 556 case ICMP_TSTAMP: 557 if (icmplen < ICMP_TSLEN) { 558 ICMP_STATINC(ICMP_STAT_BADLEN); 559 break; 560 } 561 if (!icmpbmcastecho && 562 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 563 ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); 564 break; 565 } 566 icp->icmp_type = ICMP_TSTAMPREPLY; 567 icp->icmp_rtime = iptime(); 568 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 569 goto reflect; 570 571 case ICMP_MASKREQ: { 572 struct ifnet *rcvif; 573 int s, ss; 574 struct ifaddr *ifa = NULL; 575 576 if (icmpmaskrepl == 0) 577 break; 578 /* 579 * We are not able to respond with all ones broadcast 580 * unless we receive it over a point-to-point interface. 581 */ 582 if (icmplen < ICMP_MASKLEN) { 583 ICMP_STATINC(ICMP_STAT_BADLEN); 584 break; 585 } 586 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 587 in_nullhost(ip->ip_dst)) 588 icmpdst.sin_addr = ip->ip_src; 589 else 590 icmpdst.sin_addr = ip->ip_dst; 591 ss = pserialize_read_enter(); 592 rcvif = m_get_rcvif(m, &s); 593 if (__predict_true(rcvif != NULL)) 594 ifa = ifaof_ifpforaddr(sintosa(&icmpdst), rcvif); 595 m_put_rcvif(rcvif, &s); 596 if (ifa == NULL) { 597 pserialize_read_exit(ss); 598 break; 599 } 600 ia = ifatoia(ifa); 601 icp->icmp_type = ICMP_MASKREPLY; 602 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 603 if (in_nullhost(ip->ip_src)) { 604 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 605 ip->ip_src = ia->ia_broadaddr.sin_addr; 606 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 607 ip->ip_src = ia->ia_dstaddr.sin_addr; 608 } 609 pserialize_read_exit(ss); 610 reflect: 611 { 612 uint64_t *icps = percpu_getref(icmpstat_percpu); 613 icps[ICMP_STAT_REFLECT]++; 614 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; 615 percpu_putref(icmpstat_percpu); 616 } 617 icmp_reflect(m); 618 return; 619 } 620 621 case ICMP_REDIRECT: 622 if (code > 3) 623 goto badcode; 624 if (icmp_rediraccept == 0) 625 goto freeit; 626 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 627 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 628 ICMP_STATINC(ICMP_STAT_BADLEN); 629 break; 630 } 631 /* 632 * Short circuit routing redirects to force 633 * immediate change in the kernel's routing 634 * tables. The message is also handed to anyone 635 * listening on a raw socket (e.g. the routing 636 * daemon for use in updating its tables). 637 */ 638 icmpgw.sin_addr = ip->ip_src; 639 icmpdst.sin_addr = icp->icmp_gwaddr; 640 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 641 rt = NULL; 642 rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst), 643 NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt); 644 mutex_enter(&icmp_mtx); 645 if (rt != NULL && icmp_redirtimeout != 0) { 646 i = rt_timer_add(rt, icmp_redirect_timeout, 647 icmp_redirect_timeout_q); 648 if (i) { 649 char buf[INET_ADDRSTRLEN]; 650 log(LOG_ERR, "ICMP: redirect failed to " 651 "register timeout for route to %s, " 652 "code %d\n", 653 IN_PRINT(buf, &icp->icmp_ip.ip_dst), i); 654 } 655 } 656 mutex_exit(&icmp_mtx); 657 if (rt != NULL) 658 rt_unref(rt); 659 660 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); 661 #if defined(IPSEC) 662 if (ipsec_used) 663 key_sa_routechange((struct sockaddr *)&icmpsrc); 664 #endif 665 break; 666 667 /* 668 * No kernel processing for the following; 669 * just fall through to send to raw listener. 670 */ 671 case ICMP_ECHOREPLY: 672 case ICMP_ROUTERADVERT: 673 case ICMP_ROUTERSOLICIT: 674 case ICMP_TSTAMPREPLY: 675 case ICMP_IREQREPLY: 676 case ICMP_MASKREPLY: 677 default: 678 break; 679 } 680 681 raw: 682 /* 683 * Currently, pim_input() is always called holding softnet_lock 684 * by ipintr()(!NET_MPSAFE) or PR_INPUT_WRAP()(NET_MPSAFE). 685 */ 686 KASSERT(mutex_owned(softnet_lock)); 687 rip_input(m, hlen, proto); 688 return; 689 690 freeit: 691 m_freem(m); 692 return; 693 } 694 695 void 696 icmp_input(struct mbuf *m, ...) 697 { 698 int hlen, proto; 699 va_list ap; 700 701 va_start(ap, m); 702 hlen = va_arg(ap, int); 703 proto = va_arg(ap, int); 704 va_end(ap); 705 706 wqinput_input(icmp_wqinput, m, hlen, proto); 707 } 708 709 /* 710 * Reflect the ip packet back to the source 711 */ 712 void 713 icmp_reflect(struct mbuf *m) 714 { 715 struct ip *ip = mtod(m, struct ip *); 716 struct in_ifaddr *ia; 717 struct ifaddr *ifa; 718 struct sockaddr_in *sin; 719 struct in_addr t; 720 struct mbuf *opts = NULL; 721 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 722 struct ifnet *rcvif; 723 struct psref psref, psref_ia; 724 int s; 725 int bound; 726 727 bound = curlwp_bind(); 728 729 if (!in_canforward(ip->ip_src) && 730 ((ip->ip_src.s_addr & IN_CLASSA_NET) != 731 htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { 732 m_freem(m); /* Bad return address */ 733 goto done; /* ip_output() will check for broadcast */ 734 } 735 t = ip->ip_dst; 736 ip->ip_dst = ip->ip_src; 737 738 /* 739 * If the incoming packet was addressed directly to us, use 740 * dst as the src for the reply. Otherwise (broadcast or 741 * anonymous), use an address which corresponds to the 742 * incoming interface, with a preference for the address which 743 * corresponds to the route to the destination of the ICMP. 744 */ 745 746 /* Look for packet addressed to us */ 747 ia = in_get_ia_psref(t, &psref_ia); 748 if (ia && (ia->ia4_flags & IN_IFF_NOTREADY)) { 749 ia4_release(ia, &psref_ia); 750 ia = NULL; 751 } 752 753 rcvif = m_get_rcvif_psref(m, &psref); 754 755 /* look for packet sent to broadcast address */ 756 if (ia == NULL && rcvif && 757 (rcvif->if_flags & IFF_BROADCAST)) { 758 s = pserialize_read_enter(); 759 IFADDR_READER_FOREACH(ifa, rcvif) { 760 if (ifa->ifa_addr->sa_family != AF_INET) 761 continue; 762 if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) { 763 ia = ifatoia(ifa); 764 if ((ia->ia4_flags & IN_IFF_NOTREADY) == 0) 765 break; 766 ia = NULL; 767 } 768 } 769 if (ia != NULL) 770 ia4_acquire(ia, &psref_ia); 771 pserialize_read_exit(s); 772 } 773 774 sin = ia ? &ia->ia_addr : NULL; 775 776 /* 777 * if the packet is addressed somewhere else, compute the 778 * source address for packets routed back to the source, and 779 * use that, if it's an address on the interface which 780 * received the packet 781 */ 782 if (sin == NULL && rcvif) { 783 struct sockaddr_in sin_dst; 784 struct route icmproute; 785 int errornum; 786 787 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); 788 memset(&icmproute, 0, sizeof(icmproute)); 789 errornum = 0; 790 ia = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum, 791 &psref_ia); 792 /* errornum is never used */ 793 rtcache_free(&icmproute); 794 /* check to make sure sin is a source address on rcvif */ 795 if (ia != NULL) { 796 sin = &ia->ia_addr; 797 t = sin->sin_addr; 798 sin = NULL; 799 ia4_release(ia, &psref_ia); 800 ia = in_get_ia_on_iface_psref(t, rcvif, &psref_ia); 801 if (ia != NULL) 802 sin = &ia->ia_addr; 803 } 804 } 805 806 /* 807 * if it was not addressed to us, but the route doesn't go out 808 * the source interface, pick an address on the source 809 * interface. This can happen when routing is asymmetric, or 810 * when the incoming packet was encapsulated 811 */ 812 if (sin == NULL && rcvif) { 813 KASSERT(ia == NULL); 814 s = pserialize_read_enter(); 815 IFADDR_READER_FOREACH(ifa, rcvif) { 816 if (ifa->ifa_addr->sa_family != AF_INET) 817 continue; 818 sin = &(ifatoia(ifa)->ia_addr); 819 ia = ifatoia(ifa); 820 ia4_acquire(ia, &psref_ia); 821 break; 822 } 823 pserialize_read_exit(s); 824 } 825 826 m_put_rcvif_psref(rcvif, &psref); 827 828 /* 829 * The following happens if the packet was not addressed to us, 830 * and was received on an interface with no IP address: 831 * We find the first AF_INET address on the first non-loopback 832 * interface. 833 */ 834 if (sin == NULL) { 835 KASSERT(ia == NULL); 836 s = pserialize_read_enter(); 837 IN_ADDRLIST_READER_FOREACH(ia) { 838 if (ia->ia_ifp->if_flags & IFF_LOOPBACK) 839 continue; 840 sin = &ia->ia_addr; 841 ia4_acquire(ia, &psref_ia); 842 break; 843 } 844 pserialize_read_exit(s); 845 } 846 847 /* 848 * If we still didn't find an address, punt. We could have an 849 * interface up (and receiving packets) with no address. 850 */ 851 if (sin == NULL) { 852 KASSERT(ia == NULL); 853 m_freem(m); 854 goto done; 855 } 856 857 ip->ip_src = sin->sin_addr; 858 ip->ip_ttl = MAXTTL; 859 860 if (ia != NULL) 861 ia4_release(ia, &psref_ia); 862 863 if (optlen > 0) { 864 u_char *cp; 865 int opt, cnt; 866 u_int len; 867 868 /* 869 * Retrieve any source routing from the incoming packet; 870 * add on any record-route or timestamp options. 871 */ 872 cp = (u_char *)(ip + 1); 873 if ((opts = ip_srcroute(m)) == NULL && 874 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { 875 MCLAIM(opts, m->m_owner); 876 opts->m_len = sizeof(struct in_addr); 877 *mtod(opts, struct in_addr *) = zeroin_addr; 878 } 879 880 if (opts) { 881 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 882 opt = cp[IPOPT_OPTVAL]; 883 if (opt == IPOPT_EOL) 884 break; 885 if (opt == IPOPT_NOP) 886 len = 1; 887 else { 888 if (cnt < IPOPT_OLEN + sizeof(*cp)) 889 break; 890 len = cp[IPOPT_OLEN]; 891 if (len < IPOPT_OLEN + sizeof(*cp) || 892 len > cnt) 893 break; 894 } 895 896 /* Overflows can't happen */ 897 KASSERT(opts->m_len + len <= MHLEN); 898 899 if (opt == IPOPT_RR || opt == IPOPT_TS || 900 opt == IPOPT_SECURITY) { 901 memmove(mtod(opts, char *) + 902 opts->m_len, cp, len); 903 opts->m_len += len; 904 } 905 } 906 907 /* Terminate & pad, if necessary */ 908 if ((cnt = opts->m_len % 4) != 0) { 909 for (; cnt < 4; cnt++) { 910 *(mtod(opts, char *) + opts->m_len) = 911 IPOPT_EOL; 912 opts->m_len++; 913 } 914 } 915 } 916 917 /* 918 * Now strip out original options by copying rest of first 919 * mbuf's data back, and adjust the IP length. 920 */ 921 ip->ip_len = htons(ntohs(ip->ip_len) - optlen); 922 ip->ip_hl = sizeof(struct ip) >> 2; 923 m->m_len -= optlen; 924 if (m->m_flags & M_PKTHDR) 925 m->m_pkthdr.len -= optlen; 926 optlen += sizeof(struct ip); 927 memmove(ip + 1, (char *)ip + optlen, 928 (unsigned)(m->m_len - sizeof(struct ip))); 929 } 930 m_tag_delete_nonpersistent(m); 931 m->m_flags &= ~(M_BCAST|M_MCAST); 932 933 /* 934 * Clear any in-bound checksum flags for this packet. 935 */ 936 if (m->m_flags & M_PKTHDR) 937 m->m_pkthdr.csum_flags = 0; 938 939 icmp_send(m, opts); 940 done: 941 curlwp_bindx(bound); 942 if (opts) 943 (void)m_free(opts); 944 } 945 946 /* 947 * Send an icmp packet back to the ip level, 948 * after supplying a checksum. 949 */ 950 static void 951 icmp_send(struct mbuf *m, struct mbuf *opts) 952 { 953 struct ip *ip = mtod(m, struct ip *); 954 int hlen; 955 struct icmp *icp; 956 957 hlen = ip->ip_hl << 2; 958 m->m_data += hlen; 959 m->m_len -= hlen; 960 icp = mtod(m, struct icmp *); 961 icp->icmp_cksum = 0; 962 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 963 m->m_data -= hlen; 964 m->m_len += hlen; 965 966 (void)ip_output(m, opts, NULL, 0, NULL, NULL); 967 } 968 969 n_time 970 iptime(void) 971 { 972 struct timeval atv; 973 u_long t; 974 975 microtime(&atv); 976 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 977 return (htonl(t)); 978 } 979 980 /* 981 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures 982 * that the new value is in the correct range. 983 */ 984 static int 985 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) 986 { 987 int error, t; 988 struct sysctlnode node; 989 990 node = *rnode; 991 node.sysctl_data = &t; 992 t = icmpreturndatabytes; 993 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 994 if (error || newp == NULL) 995 return error; 996 997 if (t < 8 || t > 512) 998 return EINVAL; 999 icmpreturndatabytes = t; 1000 1001 return 0; 1002 } 1003 1004 /* 1005 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that 1006 * the given value is not less than zero and then resets the timeout 1007 * queue. 1008 */ 1009 static int 1010 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) 1011 { 1012 int error, tmp; 1013 struct sysctlnode node; 1014 1015 mutex_enter(&icmp_mtx); 1016 1017 node = *rnode; 1018 node.sysctl_data = &tmp; 1019 tmp = icmp_redirtimeout; 1020 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1021 if (error || newp == NULL) 1022 goto out; 1023 if (tmp < 0) { 1024 error = EINVAL; 1025 goto out; 1026 } 1027 icmp_redirtimeout = tmp; 1028 1029 /* 1030 * was it a *defined* side-effect that anyone even *reading* 1031 * this value causes these things to happen? 1032 */ 1033 if (icmp_redirect_timeout_q != NULL) { 1034 if (icmp_redirtimeout == 0) { 1035 rt_timer_queue_destroy(icmp_redirect_timeout_q); 1036 icmp_redirect_timeout_q = NULL; 1037 } else { 1038 rt_timer_queue_change(icmp_redirect_timeout_q, 1039 icmp_redirtimeout); 1040 } 1041 } else if (icmp_redirtimeout > 0) { 1042 icmp_redirect_timeout_q = 1043 rt_timer_queue_create(icmp_redirtimeout); 1044 } 1045 error = 0; 1046 out: 1047 mutex_exit(&icmp_mtx); 1048 return error; 1049 } 1050 1051 static int 1052 sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) 1053 { 1054 1055 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); 1056 } 1057 1058 static void 1059 sysctl_netinet_icmp_setup(struct sysctllog **clog) 1060 { 1061 1062 sysctl_createv(clog, 0, NULL, NULL, 1063 CTLFLAG_PERMANENT, 1064 CTLTYPE_NODE, "inet", NULL, 1065 NULL, 0, NULL, 0, 1066 CTL_NET, PF_INET, CTL_EOL); 1067 sysctl_createv(clog, 0, NULL, NULL, 1068 CTLFLAG_PERMANENT, 1069 CTLTYPE_NODE, "icmp", 1070 SYSCTL_DESCR("ICMPv4 related settings"), 1071 NULL, 0, NULL, 0, 1072 CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL); 1073 1074 sysctl_createv(clog, 0, NULL, NULL, 1075 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1076 CTLTYPE_INT, "maskrepl", 1077 SYSCTL_DESCR("Respond to ICMP_MASKREQ messages"), 1078 NULL, 0, &icmpmaskrepl, 0, 1079 CTL_NET, PF_INET, IPPROTO_ICMP, 1080 ICMPCTL_MASKREPL, CTL_EOL); 1081 sysctl_createv(clog, 0, NULL, NULL, 1082 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1083 CTLTYPE_INT, "returndatabytes", 1084 SYSCTL_DESCR("Number of bytes to return in an ICMP " 1085 "error message"), 1086 sysctl_net_inet_icmp_returndatabytes, 0, 1087 &icmpreturndatabytes, 0, 1088 CTL_NET, PF_INET, IPPROTO_ICMP, 1089 ICMPCTL_RETURNDATABYTES, CTL_EOL); 1090 sysctl_createv(clog, 0, NULL, NULL, 1091 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1092 CTLTYPE_INT, "errppslimit", 1093 SYSCTL_DESCR("Maximum number of outgoing ICMP error " 1094 "messages per second"), 1095 NULL, 0, &icmperrppslim, 0, 1096 CTL_NET, PF_INET, IPPROTO_ICMP, 1097 ICMPCTL_ERRPPSLIMIT, CTL_EOL); 1098 sysctl_createv(clog, 0, NULL, NULL, 1099 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1100 CTLTYPE_INT, "rediraccept", 1101 SYSCTL_DESCR("Accept ICMP_REDIRECT messages"), 1102 NULL, 0, &icmp_rediraccept, 0, 1103 CTL_NET, PF_INET, IPPROTO_ICMP, 1104 ICMPCTL_REDIRACCEPT, CTL_EOL); 1105 sysctl_createv(clog, 0, NULL, NULL, 1106 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1107 CTLTYPE_INT, "redirtimeout", 1108 SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated " 1109 "routes"), 1110 sysctl_net_inet_icmp_redirtimeout, 0, 1111 &icmp_redirtimeout, 0, 1112 CTL_NET, PF_INET, IPPROTO_ICMP, 1113 ICMPCTL_REDIRTIMEOUT, CTL_EOL); 1114 sysctl_createv(clog, 0, NULL, NULL, 1115 CTLFLAG_PERMANENT, 1116 CTLTYPE_STRUCT, "stats", 1117 SYSCTL_DESCR("ICMP statistics"), 1118 sysctl_net_inet_icmp_stats, 0, NULL, 0, 1119 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS, 1120 CTL_EOL); 1121 sysctl_createv(clog, 0, NULL, NULL, 1122 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1123 CTLTYPE_INT, "bmcastecho", 1124 SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP " 1125 "message to the broadcast or multicast"), 1126 NULL, 0, &icmpbmcastecho, 0, 1127 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO, 1128 CTL_EOL); 1129 } 1130 1131 void 1132 icmp_statinc(u_int stat) 1133 { 1134 1135 KASSERT(stat < ICMP_NSTATS); 1136 ICMP_STATINC(stat); 1137 } 1138 1139 /* Table of common MTUs */ 1140 static const u_int mtu_table[] = { 1141 65535, 65280, 32000, 17914, 9180, 8166, 1142 4352, 2002, 1492, 1006, 508, 296, 68, 0 1143 }; 1144 1145 void 1146 icmp_mtudisc(struct icmp *icp, struct in_addr faddr) 1147 { 1148 struct icmp_mtudisc_callback *mc; 1149 struct sockaddr *dst = sintosa(&icmpsrc); 1150 struct rtentry *rt; 1151 u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */ 1152 int error; 1153 1154 rt = rtalloc1(dst, 1); 1155 if (rt == NULL) 1156 return; 1157 1158 /* If we didn't get a host route, allocate one */ 1159 if ((rt->rt_flags & RTF_HOST) == 0) { 1160 struct rtentry *nrt; 1161 1162 error = rtrequest(RTM_ADD, dst, rt->rt_gateway, NULL, 1163 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); 1164 if (error) { 1165 rt_unref(rt); 1166 return; 1167 } 1168 nrt->rt_rmx = rt->rt_rmx; 1169 rt_unref(rt); 1170 rt = nrt; 1171 } 1172 1173 mutex_enter(&icmp_mtx); 1174 error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q); 1175 mutex_exit(&icmp_mtx); 1176 if (error) { 1177 rt_unref(rt); 1178 return; 1179 } 1180 1181 if (mtu == 0) { 1182 int i = 0; 1183 1184 mtu = ntohs(icp->icmp_ip.ip_len); 1185 /* Some 4.2BSD-based routers incorrectly adjust the ip_len */ 1186 if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0) 1187 mtu -= (icp->icmp_ip.ip_hl << 2); 1188 1189 /* If we still can't guess a value, try the route */ 1190 if (mtu == 0) { 1191 mtu = rt->rt_rmx.rmx_mtu; 1192 1193 /* If no route mtu, default to the interface mtu */ 1194 if (mtu == 0) 1195 mtu = rt->rt_ifp->if_mtu; 1196 } 1197 1198 for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++) { 1199 if (mtu > mtu_table[i]) { 1200 mtu = mtu_table[i]; 1201 break; 1202 } 1203 } 1204 } 1205 1206 /* 1207 * XXX: RTV_MTU is overloaded, since the admin can set it 1208 * to turn off PMTU for a route, and the kernel can 1209 * set it to indicate a serious problem with PMTU 1210 * on a route. We should be using a separate flag 1211 * for the kernel to indicate this. 1212 */ 1213 1214 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1215 if (mtu < 296 || mtu > rt->rt_ifp->if_mtu) 1216 rt->rt_rmx.rmx_locks |= RTV_MTU; 1217 else if (rt->rt_rmx.rmx_mtu > mtu || 1218 rt->rt_rmx.rmx_mtu == 0) { 1219 ICMP_STATINC(ICMP_STAT_PMTUCHG); 1220 rt->rt_rmx.rmx_mtu = mtu; 1221 } 1222 } 1223 1224 if (rt != NULL) 1225 rt_unref(rt); 1226 1227 /* 1228 * Notify protocols that the MTU for this destination 1229 * has changed. 1230 */ 1231 mutex_enter(&icmp_mtx); 1232 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 1233 mc = LIST_NEXT(mc, mc_list)) 1234 (*mc->mc_func)(faddr); 1235 mutex_exit(&icmp_mtx); 1236 } 1237 1238 /* 1239 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1240 * given current value MTU. If DIR is less than zero, a larger plateau 1241 * is returned; otherwise, a smaller value is returned. 1242 */ 1243 u_int 1244 ip_next_mtu(u_int mtu, int dir) /* XXX unused */ 1245 { 1246 int i; 1247 1248 for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) { 1249 if (mtu >= mtu_table[i]) 1250 break; 1251 } 1252 1253 if (dir < 0) { 1254 if (i == 0) { 1255 return 0; 1256 } else { 1257 return mtu_table[i - 1]; 1258 } 1259 } else { 1260 if (mtu_table[i] == 0) { 1261 return 0; 1262 } else if (mtu > mtu_table[i]) { 1263 return mtu_table[i]; 1264 } else { 1265 return mtu_table[i + 1]; 1266 } 1267 } 1268 } 1269 1270 static void 1271 icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) 1272 { 1273 struct rtentry *retrt; 1274 1275 KASSERT(rt != NULL); 1276 rt_assert_referenced(rt); 1277 1278 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1279 (RTF_DYNAMIC | RTF_HOST)) { 1280 rtrequest(RTM_DELETE, rt_getkey(rt), 1281 rt->rt_gateway, rt_mask(rt), rt->rt_flags, &retrt); 1282 rt_unref(rt); 1283 rt_free(retrt); 1284 } else { 1285 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1286 rt->rt_rmx.rmx_mtu = 0; 1287 } 1288 } 1289 } 1290 1291 static void 1292 icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r) 1293 { 1294 struct rtentry *retrt; 1295 1296 KASSERT(rt != NULL); 1297 rt_assert_referenced(rt); 1298 1299 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1300 (RTF_DYNAMIC | RTF_HOST)) { 1301 rtrequest(RTM_DELETE, rt_getkey(rt), 1302 rt->rt_gateway, rt_mask(rt), rt->rt_flags, &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 Fri Oct 03 02:09:57 GMT 2025