ip_icmp.c revision 1.154.2.1
1 /* $NetBSD: ip_icmp.c,v 1.154.2.1 2017/04/21 16:54:06 bouyer 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 1.154.2.1 2017/04/21 16:54:06 bouyer 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 /* IPSEC*/ 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 #ifdef ICMPPRINTFS 144 int icmpprintfs = 0; 145 #endif 146 int icmpreturndatabytes = 8; 147 148 percpu_t *icmpstat_percpu; 149 150 /* 151 * List of callbacks to notify when Path MTU changes are made. 152 */ 153 struct icmp_mtudisc_callback { 154 LIST_ENTRY(icmp_mtudisc_callback) mc_list; 155 void (*mc_func)(struct in_addr); 156 }; 157 158 LIST_HEAD(, icmp_mtudisc_callback) icmp_mtudisc_callbacks = 159 LIST_HEAD_INITIALIZER(&icmp_mtudisc_callbacks); 160 161 #if 0 162 static u_int ip_next_mtu(u_int, int); 163 #else 164 /*static*/ u_int ip_next_mtu(u_int, int); 165 #endif 166 167 extern int icmperrppslim; 168 static int icmperrpps_count = 0; 169 static struct timeval icmperrppslim_last; 170 static int icmp_rediraccept = 1; 171 static int icmp_redirtimeout = 600; 172 static struct rttimer_queue *icmp_redirect_timeout_q = NULL; 173 174 /* Protect mtudisc and redirect stuffs */ 175 static kmutex_t icmp_mtx __cacheline_aligned; 176 177 static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *); 178 static void icmp_redirect_timeout(struct rtentry *, struct rttimer *); 179 180 static void sysctl_netinet_icmp_setup(struct sysctllog **); 181 182 /* workqueue-based pr_input */ 183 static struct wqinput *icmp_wqinput; 184 static void _icmp_input(struct mbuf *, int, int); 185 186 void 187 icmp_init(void) 188 { 189 190 sysctl_netinet_icmp_setup(NULL); 191 192 mutex_init(&icmp_mtx, MUTEX_DEFAULT, IPL_NONE); 193 /* 194 * This is only useful if the user initializes redirtimeout to 195 * something other than zero. 196 */ 197 mutex_enter(&icmp_mtx); 198 icmp_redirect_timeout_q = rt_timer_queue_create(icmp_redirtimeout); 199 mutex_exit(&icmp_mtx); 200 201 icmpstat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP_NSTATS); 202 icmp_wqinput = wqinput_create("icmp", _icmp_input); 203 } 204 205 void 206 icmp_mtudisc_lock(void) 207 { 208 209 mutex_enter(&icmp_mtx); 210 } 211 212 void 213 icmp_mtudisc_unlock(void) 214 { 215 216 mutex_exit(&icmp_mtx); 217 } 218 219 /* 220 * Register a Path MTU Discovery callback. 221 */ 222 void 223 icmp_mtudisc_callback_register(void (*func)(struct in_addr)) 224 { 225 struct icmp_mtudisc_callback *mc, *new; 226 227 new = kmem_alloc(sizeof(*mc), KM_SLEEP); 228 229 mutex_enter(&icmp_mtx); 230 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 231 mc = LIST_NEXT(mc, mc_list)) { 232 if (mc->mc_func == func) { 233 mutex_exit(&icmp_mtx); 234 kmem_free(new, sizeof(*mc)); 235 return; 236 } 237 } 238 239 new->mc_func = func; 240 LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, new, mc_list); 241 mutex_exit(&icmp_mtx); 242 } 243 244 /* 245 * Generate an error packet of type error 246 * in response to bad packet ip. 247 */ 248 void 249 icmp_error(struct mbuf *n, int type, int code, n_long dest, 250 int destmtu) 251 { 252 struct ip *oip = mtod(n, struct ip *), *nip; 253 unsigned oiplen = oip->ip_hl << 2; 254 struct icmp *icp; 255 struct mbuf *m; 256 struct m_tag *mtag; 257 unsigned icmplen, mblen; 258 259 #ifdef ICMPPRINTFS 260 if (icmpprintfs) 261 printf("icmp_error(%p, type:%d, code:%d)\n", oip, type, code); 262 #endif 263 if (type != ICMP_REDIRECT) 264 ICMP_STATINC(ICMP_STAT_ERROR); 265 /* 266 * Don't send error if the original packet was encrypted. 267 * Don't send error if not the first fragment of message. 268 * Don't error if the old packet protocol was ICMP 269 * error message, only known informational types. 270 */ 271 if (n->m_flags & M_DECRYPTED) 272 goto freeit; 273 if (oip->ip_off &~ htons(IP_MF|IP_DF)) 274 goto freeit; 275 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 276 n->m_len >= oiplen + ICMP_MINLEN && 277 !ICMP_INFOTYPE(((struct icmp *)((char *)oip + oiplen))->icmp_type)) { 278 ICMP_STATINC(ICMP_STAT_OLDICMP); 279 goto freeit; 280 } 281 /* Don't send error in response to a multicast or broadcast packet */ 282 if (n->m_flags & (M_BCAST|M_MCAST)) 283 goto freeit; 284 285 /* 286 * First, do a rate limitation check. 287 */ 288 if (icmp_ratelimit(&oip->ip_src, type, code)) { 289 /* XXX stat */ 290 goto freeit; 291 } 292 293 /* 294 * Now, formulate icmp message 295 */ 296 icmplen = oiplen + min(icmpreturndatabytes, 297 ntohs(oip->ip_len) - oiplen); 298 /* 299 * Defend against mbuf chains shorter than oip->ip_len - oiplen: 300 */ 301 mblen = 0; 302 for (m = n; m && (mblen < icmplen); m = m->m_next) 303 mblen += m->m_len; 304 icmplen = min(mblen, icmplen); 305 306 /* 307 * As we are not required to return everything we have, 308 * we return whatever we can return at ease. 309 * 310 * Note that ICMP datagrams longer than 576 octets are out of spec 311 * according to RFC1812; the limit on icmpreturndatabytes below in 312 * icmp_sysctl will keep things below that limit. 313 */ 314 315 KASSERT(ICMP_MINLEN <= MCLBYTES); 316 317 if (icmplen + ICMP_MINLEN > MCLBYTES) 318 icmplen = MCLBYTES - ICMP_MINLEN; 319 320 m = m_gethdr(M_DONTWAIT, MT_HEADER); 321 if (m && (icmplen + ICMP_MINLEN > MHLEN)) { 322 MCLGET(m, M_DONTWAIT); 323 if ((m->m_flags & M_EXT) == 0) { 324 m_freem(m); 325 m = NULL; 326 } 327 } 328 if (m == NULL) 329 goto freeit; 330 MCLAIM(m, n->m_owner); 331 m->m_len = icmplen + ICMP_MINLEN; 332 if ((m->m_flags & M_EXT) == 0) 333 MH_ALIGN(m, m->m_len); 334 else { 335 m->m_data += sizeof(struct ip); 336 m->m_len -= sizeof(struct ip); 337 } 338 icp = mtod(m, struct icmp *); 339 if ((u_int)type > ICMP_MAXTYPE) 340 panic("icmp_error"); 341 ICMP_STATINC(ICMP_STAT_OUTHIST + type); 342 icp->icmp_type = type; 343 if (type == ICMP_REDIRECT) 344 icp->icmp_gwaddr.s_addr = dest; 345 else { 346 icp->icmp_void = 0; 347 /* 348 * The following assignments assume an overlay with the 349 * zeroed icmp_void field. 350 */ 351 if (type == ICMP_PARAMPROB) { 352 icp->icmp_pptr = code; 353 code = 0; 354 } else if (type == ICMP_UNREACH && 355 code == ICMP_UNREACH_NEEDFRAG && destmtu) 356 icp->icmp_nextmtu = htons(destmtu); 357 } 358 359 icp->icmp_code = code; 360 m_copydata(n, 0, icmplen, (void *)&icp->icmp_ip); 361 362 /* 363 * Now, copy old ip header (without options) 364 * in front of icmp message. 365 */ 366 if ((m->m_flags & M_EXT) == 0 && 367 m->m_data - sizeof(struct ip) < m->m_pktdat) 368 panic("icmp len"); 369 m->m_data -= sizeof(struct ip); 370 m->m_len += sizeof(struct ip); 371 m->m_pkthdr.len = m->m_len; 372 m_copy_rcvif(m, n); 373 nip = mtod(m, struct ip *); 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 icmp_reflect(m); 391 392 freeit: 393 m_freem(n); 394 } 395 396 struct sockaddr_in icmpsrc = { 397 .sin_len = sizeof (struct sockaddr_in), 398 .sin_family = AF_INET, 399 }; 400 static struct sockaddr_in icmpdst = { 401 .sin_len = sizeof (struct sockaddr_in), 402 .sin_family = AF_INET, 403 }; 404 static struct sockaddr_in icmpgw = { 405 .sin_len = sizeof (struct sockaddr_in), 406 .sin_family = AF_INET, 407 }; 408 struct sockaddr_in icmpmask = { 409 .sin_len = 8, 410 .sin_family = 0, 411 }; 412 413 /* 414 * Process a received ICMP message. 415 */ 416 static void 417 _icmp_input(struct mbuf *m, int hlen, int proto) 418 { 419 struct icmp *icp; 420 struct ip *ip = mtod(m, struct ip *); 421 int icmplen; 422 int i; 423 struct in_ifaddr *ia; 424 void *(*ctlfunc)(int, const struct sockaddr *, void *); 425 int code; 426 struct rtentry *rt; 427 428 /* 429 * Locate icmp structure in mbuf, and check 430 * that not corrupted and of at least minimum length. 431 */ 432 icmplen = ntohs(ip->ip_len) - hlen; 433 #ifdef ICMPPRINTFS 434 if (icmpprintfs) { 435 char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; 436 printf("icmp_input from `%s' to `%s', len %d\n", 437 IN_PRINT(sbuf, &ip->ip_src), IN_PRINT(dbuf, &ip->ip_dst), 438 icmplen); 439 } 440 #endif 441 if (icmplen < ICMP_MINLEN) { 442 ICMP_STATINC(ICMP_STAT_TOOSHORT); 443 goto freeit; 444 } 445 i = hlen + min(icmplen, ICMP_ADVLENMIN); 446 if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == NULL) { 447 ICMP_STATINC(ICMP_STAT_TOOSHORT); 448 return; 449 } 450 ip = mtod(m, struct ip *); 451 m->m_len -= hlen; 452 m->m_data += hlen; 453 icp = mtod(m, struct icmp *); 454 /* Don't need to assert alignment, here. */ 455 if (in_cksum(m, icmplen)) { 456 ICMP_STATINC(ICMP_STAT_CHECKSUM); 457 goto freeit; 458 } 459 m->m_len += hlen; 460 m->m_data -= hlen; 461 462 #ifdef ICMPPRINTFS 463 /* 464 * Message type specific processing. 465 */ 466 if (icmpprintfs) 467 printf("icmp_input(type:%d, code:%d)\n", icp->icmp_type, 468 icp->icmp_code); 469 #endif 470 if (icp->icmp_type > ICMP_MAXTYPE) 471 goto raw; 472 ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type); 473 code = icp->icmp_code; 474 switch (icp->icmp_type) { 475 476 case ICMP_UNREACH: 477 switch (code) { 478 case ICMP_UNREACH_PROTOCOL: 479 code = PRC_UNREACH_PROTOCOL; 480 break; 481 482 case ICMP_UNREACH_PORT: 483 code = PRC_UNREACH_PORT; 484 break; 485 486 case ICMP_UNREACH_SRCFAIL: 487 code = PRC_UNREACH_SRCFAIL; 488 break; 489 490 case ICMP_UNREACH_NEEDFRAG: 491 code = PRC_MSGSIZE; 492 break; 493 494 case ICMP_UNREACH_NET: 495 case ICMP_UNREACH_NET_UNKNOWN: 496 case ICMP_UNREACH_NET_PROHIB: 497 case ICMP_UNREACH_TOSNET: 498 code = PRC_UNREACH_NET; 499 break; 500 501 case ICMP_UNREACH_HOST: 502 case ICMP_UNREACH_HOST_UNKNOWN: 503 case ICMP_UNREACH_ISOLATED: 504 case ICMP_UNREACH_HOST_PROHIB: 505 case ICMP_UNREACH_TOSHOST: 506 case ICMP_UNREACH_ADMIN_PROHIBIT: 507 case ICMP_UNREACH_HOST_PREC: 508 case ICMP_UNREACH_PREC_CUTOFF: 509 code = PRC_UNREACH_HOST; 510 break; 511 512 default: 513 goto badcode; 514 } 515 goto deliver; 516 517 case ICMP_TIMXCEED: 518 if (code > 1) 519 goto badcode; 520 code += PRC_TIMXCEED_INTRANS; 521 goto deliver; 522 523 case ICMP_PARAMPROB: 524 if (code > 1) 525 goto badcode; 526 code = PRC_PARAMPROB; 527 goto deliver; 528 529 case ICMP_SOURCEQUENCH: 530 if (code) 531 goto badcode; 532 code = PRC_QUENCH; 533 goto deliver; 534 535 deliver: 536 /* 537 * Problem with datagram; advise higher level routines. 538 */ 539 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 540 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 541 ICMP_STATINC(ICMP_STAT_BADLEN); 542 goto freeit; 543 } 544 if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) 545 goto badcode; 546 #ifdef ICMPPRINTFS 547 if (icmpprintfs) 548 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 549 #endif 550 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 551 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; 552 if (ctlfunc) 553 (void) (*ctlfunc)(code, sintosa(&icmpsrc), 554 &icp->icmp_ip); 555 break; 556 557 badcode: 558 ICMP_STATINC(ICMP_STAT_BADCODE); 559 break; 560 561 case ICMP_ECHO: 562 if (!icmpbmcastecho && 563 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 564 ICMP_STATINC(ICMP_STAT_BMCASTECHO); 565 break; 566 } 567 icp->icmp_type = ICMP_ECHOREPLY; 568 goto reflect; 569 570 case ICMP_TSTAMP: 571 if (icmplen < ICMP_TSLEN) { 572 ICMP_STATINC(ICMP_STAT_BADLEN); 573 break; 574 } 575 if (!icmpbmcastecho && 576 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 577 ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); 578 break; 579 } 580 icp->icmp_type = ICMP_TSTAMPREPLY; 581 icp->icmp_rtime = iptime(); 582 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 583 goto reflect; 584 585 case ICMP_MASKREQ: { 586 struct ifnet *rcvif; 587 int s, ss; 588 struct ifaddr *ifa = NULL; 589 590 if (icmpmaskrepl == 0) 591 break; 592 /* 593 * We are not able to respond with all ones broadcast 594 * unless we receive it over a point-to-point interface. 595 */ 596 if (icmplen < ICMP_MASKLEN) { 597 ICMP_STATINC(ICMP_STAT_BADLEN); 598 break; 599 } 600 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 601 in_nullhost(ip->ip_dst)) 602 icmpdst.sin_addr = ip->ip_src; 603 else 604 icmpdst.sin_addr = ip->ip_dst; 605 ss = pserialize_read_enter(); 606 rcvif = m_get_rcvif(m, &s); 607 if (__predict_true(rcvif != NULL)) 608 ifa = ifaof_ifpforaddr(sintosa(&icmpdst), rcvif); 609 m_put_rcvif(rcvif, &s); 610 if (ifa == NULL) { 611 pserialize_read_exit(ss); 612 break; 613 } 614 ia = ifatoia(ifa); 615 icp->icmp_type = ICMP_MASKREPLY; 616 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 617 if (in_nullhost(ip->ip_src)) { 618 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 619 ip->ip_src = ia->ia_broadaddr.sin_addr; 620 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 621 ip->ip_src = ia->ia_dstaddr.sin_addr; 622 } 623 pserialize_read_exit(ss); 624 reflect: 625 { 626 uint64_t *icps = percpu_getref(icmpstat_percpu); 627 icps[ICMP_STAT_REFLECT]++; 628 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; 629 percpu_putref(icmpstat_percpu); 630 } 631 icmp_reflect(m); 632 return; 633 } 634 635 case ICMP_REDIRECT: 636 if (code > 3) 637 goto badcode; 638 if (icmp_rediraccept == 0) 639 goto freeit; 640 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 641 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 642 ICMP_STATINC(ICMP_STAT_BADLEN); 643 break; 644 } 645 /* 646 * Short circuit routing redirects to force 647 * immediate change in the kernel's routing 648 * tables. The message is also handed to anyone 649 * listening on a raw socket (e.g. the routing 650 * daemon for use in updating its tables). 651 */ 652 icmpgw.sin_addr = ip->ip_src; 653 icmpdst.sin_addr = icp->icmp_gwaddr; 654 #ifdef ICMPPRINTFS 655 if (icmpprintfs) { 656 char gbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; 657 printf("redirect dst `%s' to `%s'\n", 658 IN_PRINT(dbuf, &icp->icmp_ip.ip_dst), 659 IN_PRINT(gbuf, &icp->icmp_gwaddr)); 660 } 661 #endif 662 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 663 rt = NULL; 664 rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst), 665 NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt); 666 mutex_enter(&icmp_mtx); 667 if (rt != NULL && icmp_redirtimeout != 0) { 668 i = rt_timer_add(rt, icmp_redirect_timeout, 669 icmp_redirect_timeout_q); 670 if (i) { 671 char buf[INET_ADDRSTRLEN]; 672 log(LOG_ERR, "ICMP: redirect failed to " 673 "register timeout for route to %s, " 674 "code %d\n", 675 IN_PRINT(buf, &icp->icmp_ip.ip_dst), i); 676 } 677 } 678 mutex_exit(&icmp_mtx); 679 if (rt != NULL) 680 rt_unref(rt); 681 682 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); 683 #if defined(IPSEC) 684 if (ipsec_used) 685 key_sa_routechange((struct sockaddr *)&icmpsrc); 686 #endif 687 break; 688 689 /* 690 * No kernel processing for the following; 691 * just fall through to send to raw listener. 692 */ 693 case ICMP_ECHOREPLY: 694 case ICMP_ROUTERADVERT: 695 case ICMP_ROUTERSOLICIT: 696 case ICMP_TSTAMPREPLY: 697 case ICMP_IREQREPLY: 698 case ICMP_MASKREPLY: 699 default: 700 break; 701 } 702 703 raw: 704 rip_input(m, hlen, proto); 705 return; 706 707 freeit: 708 m_freem(m); 709 return; 710 } 711 712 void 713 icmp_input(struct mbuf *m, ...) 714 { 715 int hlen, proto; 716 va_list ap; 717 718 va_start(ap, m); 719 hlen = va_arg(ap, int); 720 proto = va_arg(ap, int); 721 va_end(ap); 722 723 wqinput_input(icmp_wqinput, m, hlen, proto); 724 } 725 726 /* 727 * Reflect the ip packet back to the source 728 */ 729 void 730 icmp_reflect(struct mbuf *m) 731 { 732 struct ip *ip = mtod(m, struct ip *); 733 struct in_ifaddr *ia; 734 struct ifaddr *ifa; 735 struct sockaddr_in *sin; 736 struct in_addr t; 737 struct mbuf *opts = NULL; 738 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 739 struct ifnet *rcvif; 740 struct psref psref, psref_ia; 741 int s; 742 int bound; 743 744 bound = curlwp_bind(); 745 746 if (!in_canforward(ip->ip_src) && 747 ((ip->ip_src.s_addr & IN_CLASSA_NET) != 748 htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { 749 m_freem(m); /* Bad return address */ 750 goto done; /* ip_output() will check for broadcast */ 751 } 752 t = ip->ip_dst; 753 ip->ip_dst = ip->ip_src; 754 /* 755 * If the incoming packet was addressed directly to us, use 756 * dst as the src for the reply. Otherwise (broadcast or 757 * anonymous), use an address which corresponds to the 758 * incoming interface, with a preference for the address which 759 * corresponds to the route to the destination of the ICMP. 760 */ 761 762 /* Look for packet addressed to us */ 763 ia = in_get_ia_psref(t, &psref_ia); 764 if (ia && (ia->ia4_flags & IN_IFF_NOTREADY)) { 765 ia4_release(ia, &psref_ia); 766 ia = NULL; 767 } 768 769 rcvif = m_get_rcvif_psref(m, &psref); 770 771 /* look for packet sent to broadcast address */ 772 if (ia == NULL && rcvif && 773 (rcvif->if_flags & IFF_BROADCAST)) { 774 s = pserialize_read_enter(); 775 IFADDR_READER_FOREACH(ifa, rcvif) { 776 if (ifa->ifa_addr->sa_family != AF_INET) 777 continue; 778 if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) { 779 ia = ifatoia(ifa); 780 if ((ia->ia4_flags & IN_IFF_NOTREADY) == 0) 781 break; 782 ia = NULL; 783 } 784 } 785 if (ia != NULL) 786 ia4_acquire(ia, &psref_ia); 787 pserialize_read_exit(s); 788 } 789 790 sin = ia ? &ia->ia_addr : NULL; 791 792 icmpdst.sin_addr = t; 793 794 /* 795 * if the packet is addressed somewhere else, compute the 796 * source address for packets routed back to the source, and 797 * use that, if it's an address on the interface which 798 * received the packet 799 */ 800 if (sin == NULL && rcvif) { 801 struct sockaddr_in sin_dst; 802 struct route icmproute; 803 int errornum; 804 805 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); 806 memset(&icmproute, 0, sizeof(icmproute)); 807 errornum = 0; 808 ia = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum, 809 &psref_ia); 810 /* errornum is never used */ 811 rtcache_free(&icmproute); 812 /* check to make sure sin is a source address on rcvif */ 813 if (ia != NULL) { 814 sin = &ia->ia_addr; 815 t = sin->sin_addr; 816 sin = NULL; 817 ia4_release(ia, &psref_ia); 818 ia = in_get_ia_on_iface_psref(t, rcvif, &psref_ia); 819 if (ia != NULL) 820 sin = &ia->ia_addr; 821 } 822 } 823 824 /* 825 * if it was not addressed to us, but the route doesn't go out 826 * the source interface, pick an address on the source 827 * interface. This can happen when routing is asymmetric, or 828 * when the incoming packet was encapsulated 829 */ 830 if (sin == NULL && rcvif) { 831 KASSERT(ia == NULL); 832 s = pserialize_read_enter(); 833 IFADDR_READER_FOREACH(ifa, rcvif) { 834 if (ifa->ifa_addr->sa_family != AF_INET) 835 continue; 836 sin = &(ifatoia(ifa)->ia_addr); 837 ia = ifatoia(ifa); 838 ia4_acquire(ia, &psref_ia); 839 break; 840 } 841 pserialize_read_exit(s); 842 } 843 844 m_put_rcvif_psref(rcvif, &psref); 845 846 /* 847 * The following happens if the packet was not addressed to us, 848 * and was received on an interface with no IP address: 849 * We find the first AF_INET address on the first non-loopback 850 * interface. 851 */ 852 if (sin == NULL) { 853 KASSERT(ia == NULL); 854 s = pserialize_read_enter(); 855 IN_ADDRLIST_READER_FOREACH(ia) { 856 if (ia->ia_ifp->if_flags & IFF_LOOPBACK) 857 continue; 858 sin = &ia->ia_addr; 859 ia4_acquire(ia, &psref_ia); 860 break; 861 } 862 pserialize_read_exit(s); 863 } 864 865 /* 866 * If we still didn't find an address, punt. We could have an 867 * interface up (and receiving packets) with no address. 868 */ 869 if (sin == NULL) { 870 KASSERT(ia == NULL); 871 m_freem(m); 872 goto done; 873 } 874 875 ip->ip_src = sin->sin_addr; 876 ip->ip_ttl = MAXTTL; 877 878 if (ia != NULL) 879 ia4_release(ia, &psref_ia); 880 881 if (optlen > 0) { 882 u_char *cp; 883 int opt, cnt; 884 u_int len; 885 886 /* 887 * Retrieve any source routing from the incoming packet; 888 * add on any record-route or timestamp options. 889 */ 890 cp = (u_char *) (ip + 1); 891 if ((opts = ip_srcroute(m)) == NULL && 892 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { 893 MCLAIM(opts, m->m_owner); 894 opts->m_len = sizeof(struct in_addr); 895 *mtod(opts, struct in_addr *) = zeroin_addr; 896 } 897 if (opts) { 898 #ifdef ICMPPRINTFS 899 if (icmpprintfs) 900 printf("icmp_reflect optlen %d rt %d => ", 901 optlen, opts->m_len); 902 #endif 903 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 904 opt = cp[IPOPT_OPTVAL]; 905 if (opt == IPOPT_EOL) 906 break; 907 if (opt == IPOPT_NOP) 908 len = 1; 909 else { 910 if (cnt < IPOPT_OLEN + sizeof(*cp)) 911 break; 912 len = cp[IPOPT_OLEN]; 913 if (len < IPOPT_OLEN + sizeof(*cp) || 914 len > cnt) 915 break; 916 } 917 /* 918 * Should check for overflow, but it "can't happen" 919 */ 920 if (opt == IPOPT_RR || opt == IPOPT_TS || 921 opt == IPOPT_SECURITY) { 922 memmove(mtod(opts, char *) + opts->m_len, 923 cp, len); 924 opts->m_len += len; 925 } 926 } 927 /* Terminate & pad, if necessary */ 928 if ((cnt = opts->m_len % 4) != 0) { 929 for (; cnt < 4; cnt++) { 930 *(mtod(opts, char *) + opts->m_len) = 931 IPOPT_EOL; 932 opts->m_len++; 933 } 934 } 935 #ifdef ICMPPRINTFS 936 if (icmpprintfs) 937 printf("%d\n", opts->m_len); 938 #endif 939 } 940 /* 941 * Now strip out original options by copying rest of first 942 * mbuf's data back, and adjust the IP length. 943 */ 944 ip->ip_len = htons(ntohs(ip->ip_len) - optlen); 945 ip->ip_hl = sizeof(struct ip) >> 2; 946 m->m_len -= optlen; 947 if (m->m_flags & M_PKTHDR) 948 m->m_pkthdr.len -= optlen; 949 optlen += sizeof(struct ip); 950 memmove(ip + 1, (char *)ip + optlen, 951 (unsigned)(m->m_len - sizeof(struct ip))); 952 } 953 m_tag_delete_nonpersistent(m); 954 m->m_flags &= ~(M_BCAST|M_MCAST); 955 956 /* 957 * Clear any in-bound checksum flags for this packet. 958 */ 959 if (m->m_flags & M_PKTHDR) 960 m->m_pkthdr.csum_flags = 0; 961 962 icmp_send(m, opts); 963 done: 964 curlwp_bindx(bound); 965 if (opts) 966 (void)m_free(opts); 967 } 968 969 /* 970 * Send an icmp packet back to the ip level, 971 * after supplying a checksum. 972 */ 973 void 974 icmp_send(struct mbuf *m, struct mbuf *opts) 975 { 976 struct ip *ip = mtod(m, struct ip *); 977 int hlen; 978 struct icmp *icp; 979 980 hlen = ip->ip_hl << 2; 981 m->m_data += hlen; 982 m->m_len -= hlen; 983 icp = mtod(m, struct icmp *); 984 icp->icmp_cksum = 0; 985 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 986 m->m_data -= hlen; 987 m->m_len += hlen; 988 #ifdef ICMPPRINTFS 989 if (icmpprintfs) { 990 char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; 991 printf("icmp_send to destination `%s' from `%s'\n", 992 IN_PRINT(dbuf, &ip->ip_dst), IN_PRINT(sbuf, &ip->ip_src)); 993 } 994 #endif 995 (void)ip_output(m, opts, NULL, 0, NULL, NULL); 996 } 997 998 n_time 999 iptime(void) 1000 { 1001 struct timeval atv; 1002 u_long t; 1003 1004 microtime(&atv); 1005 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 1006 return (htonl(t)); 1007 } 1008 1009 /* 1010 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures 1011 * that the new value is in the correct range. 1012 */ 1013 static int 1014 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) 1015 { 1016 int error, t; 1017 struct sysctlnode node; 1018 1019 node = *rnode; 1020 node.sysctl_data = &t; 1021 t = icmpreturndatabytes; 1022 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1023 if (error || newp == NULL) 1024 return (error); 1025 1026 if (t < 8 || t > 512) 1027 return (EINVAL); 1028 icmpreturndatabytes = t; 1029 1030 return (0); 1031 } 1032 1033 /* 1034 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that 1035 * the given value is not less than zero and then resets the timeout 1036 * queue. 1037 */ 1038 static int 1039 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) 1040 { 1041 int error, tmp; 1042 struct sysctlnode node; 1043 1044 mutex_enter(&icmp_mtx); 1045 1046 node = *rnode; 1047 node.sysctl_data = &tmp; 1048 tmp = icmp_redirtimeout; 1049 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1050 if (error || newp == NULL) 1051 goto out; 1052 if (tmp < 0) { 1053 error = EINVAL; 1054 goto out; 1055 } 1056 icmp_redirtimeout = tmp; 1057 1058 /* 1059 * was it a *defined* side-effect that anyone even *reading* 1060 * this value causes these things to happen? 1061 */ 1062 if (icmp_redirect_timeout_q != NULL) { 1063 if (icmp_redirtimeout == 0) { 1064 rt_timer_queue_destroy(icmp_redirect_timeout_q); 1065 icmp_redirect_timeout_q = NULL; 1066 } else { 1067 rt_timer_queue_change(icmp_redirect_timeout_q, 1068 icmp_redirtimeout); 1069 } 1070 } else if (icmp_redirtimeout > 0) { 1071 icmp_redirect_timeout_q = 1072 rt_timer_queue_create(icmp_redirtimeout); 1073 } 1074 error = 0; 1075 out: 1076 mutex_exit(&icmp_mtx); 1077 return error; 1078 } 1079 1080 static int 1081 sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) 1082 { 1083 1084 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); 1085 } 1086 1087 static void 1088 sysctl_netinet_icmp_setup(struct sysctllog **clog) 1089 { 1090 1091 sysctl_createv(clog, 0, NULL, NULL, 1092 CTLFLAG_PERMANENT, 1093 CTLTYPE_NODE, "inet", NULL, 1094 NULL, 0, NULL, 0, 1095 CTL_NET, PF_INET, CTL_EOL); 1096 sysctl_createv(clog, 0, NULL, NULL, 1097 CTLFLAG_PERMANENT, 1098 CTLTYPE_NODE, "icmp", 1099 SYSCTL_DESCR("ICMPv4 related settings"), 1100 NULL, 0, NULL, 0, 1101 CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL); 1102 1103 sysctl_createv(clog, 0, NULL, NULL, 1104 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1105 CTLTYPE_INT, "maskrepl", 1106 SYSCTL_DESCR("Respond to ICMP_MASKREQ messages"), 1107 NULL, 0, &icmpmaskrepl, 0, 1108 CTL_NET, PF_INET, IPPROTO_ICMP, 1109 ICMPCTL_MASKREPL, CTL_EOL); 1110 sysctl_createv(clog, 0, NULL, NULL, 1111 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1112 CTLTYPE_INT, "returndatabytes", 1113 SYSCTL_DESCR("Number of bytes to return in an ICMP " 1114 "error message"), 1115 sysctl_net_inet_icmp_returndatabytes, 0, 1116 &icmpreturndatabytes, 0, 1117 CTL_NET, PF_INET, IPPROTO_ICMP, 1118 ICMPCTL_RETURNDATABYTES, CTL_EOL); 1119 sysctl_createv(clog, 0, NULL, NULL, 1120 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1121 CTLTYPE_INT, "errppslimit", 1122 SYSCTL_DESCR("Maximum number of outgoing ICMP error " 1123 "messages per second"), 1124 NULL, 0, &icmperrppslim, 0, 1125 CTL_NET, PF_INET, IPPROTO_ICMP, 1126 ICMPCTL_ERRPPSLIMIT, CTL_EOL); 1127 sysctl_createv(clog, 0, NULL, NULL, 1128 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1129 CTLTYPE_INT, "rediraccept", 1130 SYSCTL_DESCR("Accept ICMP_REDIRECT messages"), 1131 NULL, 0, &icmp_rediraccept, 0, 1132 CTL_NET, PF_INET, IPPROTO_ICMP, 1133 ICMPCTL_REDIRACCEPT, CTL_EOL); 1134 sysctl_createv(clog, 0, NULL, NULL, 1135 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1136 CTLTYPE_INT, "redirtimeout", 1137 SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated " 1138 "routes"), 1139 sysctl_net_inet_icmp_redirtimeout, 0, 1140 &icmp_redirtimeout, 0, 1141 CTL_NET, PF_INET, IPPROTO_ICMP, 1142 ICMPCTL_REDIRTIMEOUT, CTL_EOL); 1143 sysctl_createv(clog, 0, NULL, NULL, 1144 CTLFLAG_PERMANENT, 1145 CTLTYPE_STRUCT, "stats", 1146 SYSCTL_DESCR("ICMP statistics"), 1147 sysctl_net_inet_icmp_stats, 0, NULL, 0, 1148 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS, 1149 CTL_EOL); 1150 sysctl_createv(clog, 0, NULL, NULL, 1151 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1152 CTLTYPE_INT, "bmcastecho", 1153 SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP " 1154 "message to the broadcast or multicast"), 1155 NULL, 0, &icmpbmcastecho, 0, 1156 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO, 1157 CTL_EOL); 1158 } 1159 1160 void 1161 icmp_statinc(u_int stat) 1162 { 1163 1164 KASSERT(stat < ICMP_NSTATS); 1165 ICMP_STATINC(stat); 1166 } 1167 1168 /* Table of common MTUs: */ 1169 1170 static const u_int mtu_table[] = { 1171 65535, 65280, 32000, 17914, 9180, 8166, 1172 4352, 2002, 1492, 1006, 508, 296, 68, 0 1173 }; 1174 1175 void 1176 icmp_mtudisc(struct icmp *icp, struct in_addr faddr) 1177 { 1178 struct icmp_mtudisc_callback *mc; 1179 struct sockaddr *dst = sintosa(&icmpsrc); 1180 struct rtentry *rt; 1181 u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */ 1182 int error; 1183 1184 rt = rtalloc1(dst, 1); 1185 if (rt == NULL) 1186 return; 1187 1188 /* If we didn't get a host route, allocate one */ 1189 1190 if ((rt->rt_flags & RTF_HOST) == 0) { 1191 struct rtentry *nrt; 1192 1193 error = rtrequest(RTM_ADD, dst, rt->rt_gateway, NULL, 1194 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); 1195 if (error) { 1196 rt_unref(rt); 1197 return; 1198 } 1199 nrt->rt_rmx = rt->rt_rmx; 1200 rt_unref(rt); 1201 rt = nrt; 1202 } 1203 1204 mutex_enter(&icmp_mtx); 1205 error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q); 1206 mutex_exit(&icmp_mtx); 1207 if (error) { 1208 rt_unref(rt); 1209 return; 1210 } 1211 1212 if (mtu == 0) { 1213 int i = 0; 1214 1215 mtu = ntohs(icp->icmp_ip.ip_len); 1216 /* Some 4.2BSD-based routers incorrectly adjust the ip_len */ 1217 if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0) 1218 mtu -= (icp->icmp_ip.ip_hl << 2); 1219 1220 /* If we still can't guess a value, try the route */ 1221 1222 if (mtu == 0) { 1223 mtu = rt->rt_rmx.rmx_mtu; 1224 1225 /* If no route mtu, default to the interface mtu */ 1226 1227 if (mtu == 0) 1228 mtu = rt->rt_ifp->if_mtu; 1229 } 1230 1231 for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++) 1232 if (mtu > mtu_table[i]) { 1233 mtu = mtu_table[i]; 1234 break; 1235 } 1236 } 1237 1238 /* 1239 * XXX: RTV_MTU is overloaded, since the admin can set it 1240 * to turn off PMTU for a route, and the kernel can 1241 * set it to indicate a serious problem with PMTU 1242 * on a route. We should be using a separate flag 1243 * for the kernel to indicate this. 1244 */ 1245 1246 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1247 if (mtu < 296 || mtu > rt->rt_ifp->if_mtu) 1248 rt->rt_rmx.rmx_locks |= RTV_MTU; 1249 else if (rt->rt_rmx.rmx_mtu > mtu || 1250 rt->rt_rmx.rmx_mtu == 0) { 1251 ICMP_STATINC(ICMP_STAT_PMTUCHG); 1252 rt->rt_rmx.rmx_mtu = mtu; 1253 } 1254 } 1255 1256 if (rt != NULL) 1257 rt_unref(rt); 1258 1259 /* 1260 * Notify protocols that the MTU for this destination 1261 * has changed. 1262 */ 1263 mutex_enter(&icmp_mtx); 1264 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 1265 mc = LIST_NEXT(mc, mc_list)) 1266 (*mc->mc_func)(faddr); 1267 mutex_exit(&icmp_mtx); 1268 } 1269 1270 /* 1271 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1272 * given current value MTU. If DIR is less than zero, a larger plateau 1273 * is returned; otherwise, a smaller value is returned. 1274 */ 1275 u_int 1276 ip_next_mtu(u_int mtu, int dir) /* XXX */ 1277 { 1278 int i; 1279 1280 for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) { 1281 if (mtu >= mtu_table[i]) 1282 break; 1283 } 1284 1285 if (dir < 0) { 1286 if (i == 0) { 1287 return 0; 1288 } else { 1289 return mtu_table[i - 1]; 1290 } 1291 } else { 1292 if (mtu_table[i] == 0) { 1293 return 0; 1294 } else if (mtu > mtu_table[i]) { 1295 return mtu_table[i]; 1296 } else { 1297 return mtu_table[i + 1]; 1298 } 1299 } 1300 } 1301 1302 static void 1303 icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) 1304 { 1305 1306 KASSERT(rt != NULL); 1307 rt_assert_referenced(rt); 1308 1309 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1310 (RTF_DYNAMIC | RTF_HOST)) { 1311 rtrequest(RTM_DELETE, rt_getkey(rt), 1312 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); 1313 } else { 1314 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1315 rt->rt_rmx.rmx_mtu = 0; 1316 } 1317 } 1318 } 1319 1320 static void 1321 icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r) 1322 { 1323 1324 KASSERT(rt != NULL); 1325 rt_assert_referenced(rt); 1326 1327 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1328 (RTF_DYNAMIC | RTF_HOST)) { 1329 rtrequest(RTM_DELETE, rt_getkey(rt), 1330 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); 1331 } 1332 } 1333 1334 /* 1335 * Perform rate limit check. 1336 * Returns 0 if it is okay to send the icmp packet. 1337 * Returns 1 if the router SHOULD NOT send this icmp packet due to rate 1338 * limitation. 1339 * 1340 * XXX per-destination/type check necessary? 1341 */ 1342 int 1343 icmp_ratelimit(const struct in_addr *dst, const int type, 1344 const int code) 1345 { 1346 1347 /* PPS limit */ 1348 if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count, 1349 icmperrppslim)) { 1350 /* The packet is subject to rate limit */ 1351 return 1; 1352 } 1353 1354 /* okay to send */ 1355 return 0; 1356 } 1357
Indexes created Fri Oct 03 02:09:57 GMT 2025