1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1993 5 * The Regents of the University of California. 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 University 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 REGENTS 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 REGENTS 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 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 32 */ 33 34 #include <sys/cdefs.h> 35 #include "opt_inet.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/mbuf.h> 40 #include <sys/protosw.h> 41 #include <sys/socket.h> 42 #include <sys/time.h> 43 #include <sys/kernel.h> 44 #include <sys/lock.h> 45 #include <sys/sysctl.h> 46 #include <sys/syslog.h> 47 48 #include <net/if.h> 49 #include <net/if_var.h> 50 #include <net/if_private.h> 51 #include <net/if_types.h> 52 #include <net/route.h> 53 #include <net/route/route_ctl.h> 54 #include <net/route/nhop.h> 55 #include <net/vnet.h> 56 57 #include <netinet/in.h> 58 #include <netinet/in_fib.h> 59 #include <netinet/in_pcb.h> 60 #include <netinet/in_systm.h> 61 #include <netinet/in_var.h> 62 #include <netinet/ip.h> 63 #include <netinet/ip_icmp.h> 64 #include <netinet/ip_var.h> 65 #include <netinet/ip_options.h> 66 #include <netinet/sctp.h> 67 #include <netinet/tcp.h> 68 #include <netinet/tcpip.h> 69 #include <netinet/icmp_var.h> 70 71 #ifdef INET 72 73 #include <machine/in_cksum.h> 74 75 #include <security/mac/mac_framework.h> 76 #endif /* INET */ 77 78 extern ipproto_ctlinput_t *ip_ctlprotox[]; 79 80 /* 81 * ICMP routines: error generation, receive packet processing, and 82 * routines to turnaround packets back to the originator, and 83 * host table maintenance routines. 84 */ 85 static int sysctl_icmplim_and_jitter(SYSCTL_HANDLER_ARGS); 86 VNET_DEFINE_STATIC(u_int, icmplim) = 200; 87 #define V_icmplim VNET(icmplim) 88 SYSCTL_PROC(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLTYPE_UINT | 89 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmplim), 0, 90 &sysctl_icmplim_and_jitter, "IU", 91 "Maximum number of ICMP responses per second"); 92 93 VNET_DEFINE_STATIC(int, icmplim_curr_jitter) = 0; 94 #define V_icmplim_curr_jitter VNET(icmplim_curr_jitter) 95 VNET_DEFINE_STATIC(u_int, icmplim_jitter) = 16; 96 #define V_icmplim_jitter VNET(icmplim_jitter) 97 SYSCTL_PROC(_net_inet_icmp, OID_AUTO, icmplim_jitter, CTLTYPE_UINT | 98 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmplim_jitter), 0, 99 &sysctl_icmplim_and_jitter, "IU", 100 "Random icmplim jitter adjustment limit"); 101 102 VNET_DEFINE_STATIC(int, icmplim_output) = 1; 103 #define V_icmplim_output VNET(icmplim_output) 104 SYSCTL_INT(_net_inet_icmp, OID_AUTO, icmplim_output, CTLFLAG_VNET | CTLFLAG_RW, 105 &VNET_NAME(icmplim_output), 0, 106 "Enable logging of ICMP response rate limiting"); 107 108 #ifdef INET 109 VNET_PCPUSTAT_DEFINE(struct icmpstat, icmpstat); 110 VNET_PCPUSTAT_SYSINIT(icmpstat); 111 SYSCTL_VNET_PCPUSTAT(_net_inet_icmp, ICMPCTL_STATS, stats, struct icmpstat, 112 icmpstat, "ICMP statistics (struct icmpstat, netinet/icmp_var.h)"); 113 114 #ifdef VIMAGE 115 VNET_PCPUSTAT_SYSUNINIT(icmpstat); 116 #endif /* VIMAGE */ 117 118 VNET_DEFINE_STATIC(int, icmpmaskrepl) = 0; 119 #define V_icmpmaskrepl VNET(icmpmaskrepl) 120 SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_VNET | CTLFLAG_RW, 121 &VNET_NAME(icmpmaskrepl), 0, 122 "Reply to ICMP Address Mask Request packets"); 123 124 VNET_DEFINE_STATIC(u_int, icmpmaskfake) = 0; 125 #define V_icmpmaskfake VNET(icmpmaskfake) 126 SYSCTL_UINT(_net_inet_icmp, OID_AUTO, maskfake, CTLFLAG_VNET | CTLFLAG_RW, 127 &VNET_NAME(icmpmaskfake), 0, 128 "Fake reply to ICMP Address Mask Request packets"); 129 130 VNET_DEFINE(int, drop_redirect) = 0; 131 #define V_drop_redirect VNET(drop_redirect) 132 SYSCTL_INT(_net_inet_icmp, OID_AUTO, drop_redirect, CTLFLAG_VNET | CTLFLAG_RW, 133 &VNET_NAME(drop_redirect), 0, 134 "Ignore ICMP redirects"); 135 136 VNET_DEFINE_STATIC(int, log_redirect) = 0; 137 #define V_log_redirect VNET(log_redirect) 138 SYSCTL_INT(_net_inet_icmp, OID_AUTO, log_redirect, CTLFLAG_VNET | CTLFLAG_RW, 139 &VNET_NAME(log_redirect), 0, 140 "Log ICMP redirects to the console"); 141 142 VNET_DEFINE_STATIC(int, redirtimeout) = 60 * 10; /* 10 minutes */ 143 #define V_redirtimeout VNET(redirtimeout) 144 SYSCTL_INT(_net_inet_icmp, OID_AUTO, redirtimeout, CTLFLAG_VNET | CTLFLAG_RW, 145 &VNET_NAME(redirtimeout), 0, 146 "Delay in seconds before expiring redirect route"); 147 148 VNET_DEFINE_STATIC(char, reply_src[IFNAMSIZ]); 149 #define V_reply_src VNET(reply_src) 150 SYSCTL_STRING(_net_inet_icmp, OID_AUTO, reply_src, CTLFLAG_VNET | CTLFLAG_RW, 151 &VNET_NAME(reply_src), IFNAMSIZ, 152 "ICMP reply source for non-local packets"); 153 154 VNET_DEFINE_STATIC(int, icmp_rfi) = 0; 155 #define V_icmp_rfi VNET(icmp_rfi) 156 SYSCTL_INT(_net_inet_icmp, OID_AUTO, reply_from_interface, CTLFLAG_VNET | CTLFLAG_RW, 157 &VNET_NAME(icmp_rfi), 0, 158 "ICMP reply from incoming interface for non-local packets"); 159 /* Router requirements RFC 1812 section 4.3.2.3 requires 576 - 28. */ 160 VNET_DEFINE_STATIC(int, icmp_quotelen) = 548; 161 #define V_icmp_quotelen VNET(icmp_quotelen) 162 SYSCTL_INT(_net_inet_icmp, OID_AUTO, quotelen, CTLFLAG_VNET | CTLFLAG_RW, 163 &VNET_NAME(icmp_quotelen), 0, 164 "Number of bytes from original packet to quote in ICMP reply"); 165 166 VNET_DEFINE_STATIC(int, icmpbmcastecho) = 0; 167 #define V_icmpbmcastecho VNET(icmpbmcastecho) 168 SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_VNET | CTLFLAG_RW, 169 &VNET_NAME(icmpbmcastecho), 0, 170 "Reply to multicast ICMP Echo Request and Timestamp packets"); 171 172 VNET_DEFINE_STATIC(int, icmptstamprepl) = 1; 173 #define V_icmptstamprepl VNET(icmptstamprepl) 174 SYSCTL_INT(_net_inet_icmp, OID_AUTO, tstamprepl, CTLFLAG_VNET | CTLFLAG_RW, 175 &VNET_NAME(icmptstamprepl), 0, 176 "Respond to ICMP Timestamp packets"); 177 178 VNET_DEFINE_STATIC(int, error_keeptags) = 0; 179 #define V_error_keeptags VNET(error_keeptags) 180 SYSCTL_INT(_net_inet_icmp, OID_AUTO, error_keeptags, CTLFLAG_VNET | CTLFLAG_RW, 181 &VNET_NAME(error_keeptags), 0, 182 "ICMP error response keeps copy of mbuf_tags of original packet"); 183 184 #ifdef ICMPPRINTFS 185 int icmpprintfs = 0; 186 #endif 187 188 static void icmp_reflect(struct mbuf *); 189 static void icmp_send(struct mbuf *, struct mbuf *); 190 static int icmp_verify_redirect_gateway(struct sockaddr_in *, 191 struct sockaddr_in *, struct sockaddr_in *, u_int); 192 193 /* 194 * Kernel module interface for updating icmpstat. The argument is an index 195 * into icmpstat treated as an array of u_long. While this encodes the 196 * general layout of icmpstat into the caller, it doesn't encode its 197 * location, so that future changes to add, for example, per-CPU stats 198 * support won't cause binary compatibility problems for kernel modules. 199 */ 200 void 201 kmod_icmpstat_inc(int statnum) 202 { 203 204 counter_u64_add(VNET(icmpstat)[statnum], 1); 205 } 206 207 /* 208 * Generate an error packet of type error 209 * in response to bad packet ip. 210 */ 211 void 212 icmp_error(struct mbuf *n, int type, int code, uint32_t dest, int mtu) 213 { 214 struct ip *oip, *nip; 215 struct icmp *icp; 216 struct mbuf *m; 217 unsigned icmplen, icmpelen, nlen, oiphlen; 218 219 KASSERT((u_int)type <= ICMP_MAXTYPE, ("%s: illegal ICMP type", 220 __func__)); 221 222 if (type != ICMP_REDIRECT) 223 ICMPSTAT_INC(icps_error); 224 /* 225 * Don't send error: 226 * if the original packet was encrypted. 227 * if not the first fragment of message. 228 * in response to a multicast or broadcast packet. 229 * if the old packet protocol was an ICMP error message. 230 */ 231 if (n->m_flags & M_DECRYPTED) 232 goto freeit; 233 if (n->m_flags & (M_BCAST|M_MCAST)) 234 goto freeit; 235 236 /* Drop if IP header plus 8 bytes is not contiguous in first mbuf. */ 237 if (n->m_len < sizeof(struct ip) + ICMP_MINLEN) 238 goto freeit; 239 oip = mtod(n, struct ip *); 240 oiphlen = oip->ip_hl << 2; 241 if (n->m_len < oiphlen + ICMP_MINLEN) 242 goto freeit; 243 #ifdef ICMPPRINTFS 244 if (icmpprintfs) 245 printf("icmp_error(%p, %x, %d)\n", oip, type, code); 246 #endif 247 if (oip->ip_off & htons(~(IP_MF|IP_DF))) 248 goto freeit; 249 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 250 !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + 251 oiphlen))->icmp_type)) { 252 ICMPSTAT_INC(icps_oldicmp); 253 goto freeit; 254 } 255 /* 256 * Calculate length to quote from original packet and 257 * prevent the ICMP mbuf from overflowing. 258 * Unfortunately this is non-trivial since ip_forward() 259 * sends us truncated packets. 260 */ 261 nlen = m_length(n, NULL); 262 if (oip->ip_p == IPPROTO_TCP) { 263 struct tcphdr *th; 264 int tcphlen; 265 266 if (oiphlen + sizeof(struct tcphdr) > n->m_len && 267 n->m_next == NULL) 268 goto stdreply; 269 if (n->m_len < oiphlen + sizeof(struct tcphdr) && 270 (n = m_pullup(n, oiphlen + sizeof(struct tcphdr))) == NULL) 271 goto freeit; 272 oip = mtod(n, struct ip *); 273 th = mtodo(n, oiphlen); 274 tcphlen = th->th_off << 2; 275 if (tcphlen < sizeof(struct tcphdr)) 276 goto freeit; 277 if (ntohs(oip->ip_len) < oiphlen + tcphlen) 278 goto freeit; 279 if (oiphlen + tcphlen > n->m_len && n->m_next == NULL) 280 goto stdreply; 281 if (n->m_len < oiphlen + tcphlen && 282 (n = m_pullup(n, oiphlen + tcphlen)) == NULL) 283 goto freeit; 284 oip = mtod(n, struct ip *); 285 icmpelen = max(tcphlen, min(V_icmp_quotelen, 286 ntohs(oip->ip_len) - oiphlen)); 287 } else if (oip->ip_p == IPPROTO_SCTP) { 288 struct sctphdr *sh; 289 struct sctp_chunkhdr *ch; 290 291 if (ntohs(oip->ip_len) < oiphlen + sizeof(struct sctphdr)) 292 goto stdreply; 293 if (oiphlen + sizeof(struct sctphdr) > n->m_len && 294 n->m_next == NULL) 295 goto stdreply; 296 if (n->m_len < oiphlen + sizeof(struct sctphdr) && 297 (n = m_pullup(n, oiphlen + sizeof(struct sctphdr))) == NULL) 298 goto freeit; 299 oip = mtod(n, struct ip *); 300 icmpelen = max(sizeof(struct sctphdr), 301 min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen)); 302 sh = mtodo(n, oiphlen); 303 if (ntohl(sh->v_tag) == 0 && 304 ntohs(oip->ip_len) >= oiphlen + 305 sizeof(struct sctphdr) + 8 && 306 (n->m_len >= oiphlen + sizeof(struct sctphdr) + 8 || 307 n->m_next != NULL)) { 308 if (n->m_len < oiphlen + sizeof(struct sctphdr) + 8 && 309 (n = m_pullup(n, oiphlen + 310 sizeof(struct sctphdr) + 8)) == NULL) 311 goto freeit; 312 oip = mtod(n, struct ip *); 313 sh = mtodo(n, oiphlen); 314 ch = (struct sctp_chunkhdr *)(sh + 1); 315 if (ch->chunk_type == SCTP_INITIATION) { 316 icmpelen = max(sizeof(struct sctphdr) + 8, 317 min(V_icmp_quotelen, ntohs(oip->ip_len) - 318 oiphlen)); 319 } 320 } 321 } else 322 stdreply: icmpelen = max(8, min(V_icmp_quotelen, ntohs(oip->ip_len) - 323 oiphlen)); 324 325 icmplen = min(oiphlen + icmpelen, nlen); 326 if (icmplen < sizeof(struct ip)) 327 goto freeit; 328 329 if (MHLEN > sizeof(struct ip) + ICMP_MINLEN + icmplen) 330 m = m_gethdr(M_NOWAIT, MT_DATA); 331 else 332 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 333 if (m == NULL) 334 goto freeit; 335 #ifdef MAC 336 mac_netinet_icmp_reply(n, m); 337 #endif 338 icmplen = min(icmplen, M_TRAILINGSPACE(m) - 339 sizeof(struct ip) - ICMP_MINLEN); 340 m_align(m, sizeof(struct ip) + ICMP_MINLEN + icmplen); 341 m->m_data += sizeof(struct ip); 342 m->m_len = ICMP_MINLEN + icmplen; 343 344 /* XXX MRT make the outgoing packet use the same FIB 345 * that was associated with the incoming packet 346 */ 347 M_SETFIB(m, M_GETFIB(n)); 348 icp = mtod(m, struct icmp *); 349 ICMPSTAT_INC(icps_outhist[type]); 350 icp->icmp_type = type; 351 if (type == ICMP_REDIRECT) 352 icp->icmp_gwaddr.s_addr = dest; 353 else { 354 icp->icmp_void = 0; 355 /* 356 * The following assignments assume an overlay with the 357 * just zeroed icmp_void field. 358 */ 359 if (type == ICMP_PARAMPROB) { 360 icp->icmp_pptr = code; 361 code = 0; 362 } else if (type == ICMP_UNREACH && 363 code == ICMP_UNREACH_NEEDFRAG && mtu) { 364 icp->icmp_nextmtu = htons(mtu); 365 } 366 } 367 icp->icmp_code = code; 368 369 /* 370 * Copy the quotation into ICMP message and 371 * convert quoted IP header back to network representation. 372 */ 373 m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip); 374 nip = &icp->icmp_ip; 375 376 /* 377 * Set up ICMP message mbuf and copy old IP header (without options 378 * in front of ICMP message. 379 * If the original mbuf was meant to bypass the firewall, the error 380 * reply should bypass as well. 381 */ 382 m->m_flags |= n->m_flags & M_SKIP_FIREWALL; 383 KASSERT(M_LEADINGSPACE(m) >= sizeof(struct ip), 384 ("insufficient space for ip header")); 385 m->m_data -= sizeof(struct ip); 386 m->m_len += sizeof(struct ip); 387 m->m_pkthdr.len = m->m_len; 388 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif; 389 nip = mtod(m, struct ip *); 390 bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip)); 391 nip->ip_len = htons(m->m_len); 392 nip->ip_v = IPVERSION; 393 nip->ip_hl = 5; 394 nip->ip_p = IPPROTO_ICMP; 395 nip->ip_tos = 0; 396 nip->ip_off = 0; 397 398 if (V_error_keeptags) 399 m_tag_copy_chain(m, n, M_NOWAIT); 400 401 icmp_reflect(m); 402 403 freeit: 404 m_freem(n); 405 } 406 407 int 408 icmp_errmap(const struct icmp *icp) 409 { 410 411 switch (icp->icmp_type) { 412 case ICMP_UNREACH: 413 switch (icp->icmp_code) { 414 case ICMP_UNREACH_NET: 415 case ICMP_UNREACH_HOST: 416 case ICMP_UNREACH_SRCFAIL: 417 case ICMP_UNREACH_NET_UNKNOWN: 418 case ICMP_UNREACH_HOST_UNKNOWN: 419 case ICMP_UNREACH_ISOLATED: 420 case ICMP_UNREACH_TOSNET: 421 case ICMP_UNREACH_TOSHOST: 422 case ICMP_UNREACH_HOST_PRECEDENCE: 423 case ICMP_UNREACH_PRECEDENCE_CUTOFF: 424 return (EHOSTUNREACH); 425 case ICMP_UNREACH_NEEDFRAG: 426 return (EMSGSIZE); 427 case ICMP_UNREACH_PROTOCOL: 428 case ICMP_UNREACH_PORT: 429 case ICMP_UNREACH_NET_PROHIB: 430 case ICMP_UNREACH_HOST_PROHIB: 431 case ICMP_UNREACH_FILTER_PROHIB: 432 return (ECONNREFUSED); 433 default: 434 return (0); 435 } 436 case ICMP_TIMXCEED: 437 switch (icp->icmp_code) { 438 case ICMP_TIMXCEED_INTRANS: 439 return (EHOSTUNREACH); 440 default: 441 return (0); 442 } 443 case ICMP_PARAMPROB: 444 switch (icp->icmp_code) { 445 case ICMP_PARAMPROB_ERRATPTR: 446 case ICMP_PARAMPROB_OPTABSENT: 447 return (ENOPROTOOPT); 448 default: 449 return (0); 450 } 451 default: 452 return (0); 453 } 454 } 455 456 /* 457 * Process a received ICMP message. 458 */ 459 int 460 icmp_input(struct mbuf **mp, int *offp, int proto) 461 { 462 struct icmp *icp; 463 struct in_ifaddr *ia; 464 struct mbuf *m = *mp; 465 struct ip *ip = mtod(m, struct ip *); 466 struct sockaddr_in icmpsrc, icmpdst, icmpgw; 467 int hlen = *offp; 468 int icmplen = ntohs(ip->ip_len) - *offp; 469 int i, code; 470 int fibnum; 471 472 NET_EPOCH_ASSERT(); 473 474 *mp = NULL; 475 476 /* 477 * Locate icmp structure in mbuf, and check 478 * that not corrupted and of at least minimum length. 479 */ 480 #ifdef ICMPPRINTFS 481 if (icmpprintfs) { 482 char srcbuf[INET_ADDRSTRLEN]; 483 char dstbuf[INET_ADDRSTRLEN]; 484 485 printf("icmp_input from %s to %s, len %d\n", 486 inet_ntoa_r(ip->ip_src, srcbuf), 487 inet_ntoa_r(ip->ip_dst, dstbuf), icmplen); 488 } 489 #endif 490 if (icmplen < ICMP_MINLEN) { 491 ICMPSTAT_INC(icps_tooshort); 492 goto freeit; 493 } 494 i = hlen + min(icmplen, ICMP_ADVLENMIN); 495 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) { 496 ICMPSTAT_INC(icps_tooshort); 497 return (IPPROTO_DONE); 498 } 499 ip = mtod(m, struct ip *); 500 m->m_len -= hlen; 501 m->m_data += hlen; 502 icp = mtod(m, struct icmp *); 503 if (in_cksum(m, icmplen)) { 504 ICMPSTAT_INC(icps_checksum); 505 goto freeit; 506 } 507 m->m_len += hlen; 508 m->m_data -= hlen; 509 510 #ifdef ICMPPRINTFS 511 if (icmpprintfs) 512 printf("icmp_input, type %d code %d\n", icp->icmp_type, 513 icp->icmp_code); 514 #endif 515 516 /* 517 * Message type specific processing. 518 */ 519 if (icp->icmp_type > ICMP_MAXTYPE) 520 goto raw; 521 522 /* Initialize */ 523 bzero(&icmpsrc, sizeof(icmpsrc)); 524 icmpsrc.sin_len = sizeof(struct sockaddr_in); 525 icmpsrc.sin_family = AF_INET; 526 bzero(&icmpdst, sizeof(icmpdst)); 527 icmpdst.sin_len = sizeof(struct sockaddr_in); 528 icmpdst.sin_family = AF_INET; 529 bzero(&icmpgw, sizeof(icmpgw)); 530 icmpgw.sin_len = sizeof(struct sockaddr_in); 531 icmpgw.sin_family = AF_INET; 532 533 ICMPSTAT_INC(icps_inhist[icp->icmp_type]); 534 code = icp->icmp_code; 535 switch (icp->icmp_type) { 536 case ICMP_UNREACH: 537 if (code > ICMP_UNREACH_PRECEDENCE_CUTOFF) 538 goto badcode; 539 else 540 goto deliver; 541 542 case ICMP_TIMXCEED: 543 if (code > ICMP_TIMXCEED_REASS) 544 goto badcode; 545 else 546 goto deliver; 547 548 case ICMP_PARAMPROB: 549 if (code > ICMP_PARAMPROB_LENGTH) 550 goto badcode; 551 552 deliver: 553 /* 554 * Problem with datagram; advise higher level routines. 555 */ 556 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 557 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 558 ICMPSTAT_INC(icps_badlen); 559 goto freeit; 560 } 561 /* Discard ICMP's in response to multicast packets */ 562 if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr))) 563 goto badcode; 564 /* Filter out responses to INADDR_ANY, protocols ignore it. */ 565 if (icp->icmp_ip.ip_dst.s_addr == INADDR_ANY || 566 icp->icmp_ip.ip_src.s_addr == INADDR_ANY) 567 goto freeit; 568 #ifdef ICMPPRINTFS 569 if (icmpprintfs) 570 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 571 #endif 572 /* 573 * XXX if the packet contains [IPv4 AH TCP], we can't make a 574 * notification to TCP layer. 575 */ 576 i = sizeof(struct ip) + min(icmplen, ICMP_ADVLENPREF(icp)); 577 ip_stripoptions(m); 578 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) { 579 /* This should actually not happen */ 580 ICMPSTAT_INC(icps_tooshort); 581 return (IPPROTO_DONE); 582 } 583 ip = mtod(m, struct ip *); 584 icp = (struct icmp *)(ip + 1); 585 /* 586 * The upper layer handler can rely on: 587 * - The outer IP header has no options. 588 * - The outer IP header, the ICMP header, the inner IP header, 589 * and the first n bytes of the inner payload are contiguous. 590 * n is at least 8, but might be larger based on 591 * ICMP_ADVLENPREF. See its definition in ip_icmp.h. 592 */ 593 if (ip_ctlprotox[icp->icmp_ip.ip_p] != NULL) 594 ip_ctlprotox[icp->icmp_ip.ip_p](icp); 595 break; 596 597 badcode: 598 ICMPSTAT_INC(icps_badcode); 599 break; 600 601 case ICMP_ECHO: 602 if (!V_icmpbmcastecho 603 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 604 ICMPSTAT_INC(icps_bmcastecho); 605 break; 606 } 607 if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0) 608 goto freeit; 609 icp->icmp_type = ICMP_ECHOREPLY; 610 goto reflect; 611 612 case ICMP_TSTAMP: 613 if (V_icmptstamprepl == 0) 614 break; 615 if (!V_icmpbmcastecho 616 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 617 ICMPSTAT_INC(icps_bmcasttstamp); 618 break; 619 } 620 if (icmplen < ICMP_TSLEN) { 621 ICMPSTAT_INC(icps_badlen); 622 break; 623 } 624 if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0) 625 goto freeit; 626 icp->icmp_type = ICMP_TSTAMPREPLY; 627 icp->icmp_rtime = iptime(); 628 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 629 goto reflect; 630 631 case ICMP_MASKREQ: 632 if (V_icmpmaskrepl == 0) 633 break; 634 /* 635 * We are not able to respond with all ones broadcast 636 * unless we receive it over a point-to-point interface. 637 */ 638 if (icmplen < ICMP_MASKLEN) 639 break; 640 switch (ip->ip_dst.s_addr) { 641 case INADDR_BROADCAST: 642 case INADDR_ANY: 643 icmpdst.sin_addr = ip->ip_src; 644 break; 645 646 default: 647 icmpdst.sin_addr = ip->ip_dst; 648 } 649 ia = (struct in_ifaddr *)ifaof_ifpforaddr( 650 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif); 651 if (ia == NULL) 652 break; 653 if (ia->ia_ifp == NULL) 654 break; 655 icp->icmp_type = ICMP_MASKREPLY; 656 if (V_icmpmaskfake == 0) 657 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 658 else 659 icp->icmp_mask = V_icmpmaskfake; 660 if (ip->ip_src.s_addr == 0) { 661 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 662 ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr; 663 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 664 ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr; 665 } 666 reflect: 667 ICMPSTAT_INC(icps_reflect); 668 ICMPSTAT_INC(icps_outhist[icp->icmp_type]); 669 icmp_reflect(m); 670 return (IPPROTO_DONE); 671 672 case ICMP_REDIRECT: 673 if (V_log_redirect) { 674 u_long src, dst, gw; 675 676 src = ntohl(ip->ip_src.s_addr); 677 dst = ntohl(icp->icmp_ip.ip_dst.s_addr); 678 gw = ntohl(icp->icmp_gwaddr.s_addr); 679 printf("icmp redirect from %d.%d.%d.%d: " 680 "%d.%d.%d.%d => %d.%d.%d.%d\n", 681 (int)(src >> 24), (int)((src >> 16) & 0xff), 682 (int)((src >> 8) & 0xff), (int)(src & 0xff), 683 (int)(dst >> 24), (int)((dst >> 16) & 0xff), 684 (int)((dst >> 8) & 0xff), (int)(dst & 0xff), 685 (int)(gw >> 24), (int)((gw >> 16) & 0xff), 686 (int)((gw >> 8) & 0xff), (int)(gw & 0xff)); 687 } 688 /* 689 * RFC1812 says we must ignore ICMP redirects if we 690 * are acting as router. 691 */ 692 if (V_drop_redirect || V_ipforwarding) 693 break; 694 if (code > 3) 695 goto badcode; 696 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 697 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 698 ICMPSTAT_INC(icps_badlen); 699 break; 700 } 701 /* 702 * Short circuit routing redirects to force 703 * immediate change in the kernel's routing 704 * tables. The message is also handed to anyone 705 * listening on a raw socket (e.g. the routing 706 * daemon for use in updating its tables). 707 */ 708 icmpgw.sin_addr = ip->ip_src; 709 icmpdst.sin_addr = icp->icmp_gwaddr; 710 #ifdef ICMPPRINTFS 711 if (icmpprintfs) { 712 char dstbuf[INET_ADDRSTRLEN]; 713 char gwbuf[INET_ADDRSTRLEN]; 714 715 printf("redirect dst %s to %s\n", 716 inet_ntoa_r(icp->icmp_ip.ip_dst, dstbuf), 717 inet_ntoa_r(icp->icmp_gwaddr, gwbuf)); 718 } 719 #endif 720 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 721 722 /* 723 * RFC 1122 says network (code 0,2) redirects SHOULD 724 * be treated identically to the host redirects. 725 * Given that, ignore network masks. 726 */ 727 728 /* 729 * Variable values: 730 * icmpsrc: route destination 731 * icmpdst: route gateway 732 * icmpgw: message source 733 */ 734 735 if (icmp_verify_redirect_gateway(&icmpgw, &icmpsrc, &icmpdst, 736 M_GETFIB(m)) != 0) { 737 /* TODO: increment bad redirects here */ 738 break; 739 } 740 741 for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) { 742 rib_add_redirect(fibnum, (struct sockaddr *)&icmpsrc, 743 (struct sockaddr *)&icmpdst, 744 (struct sockaddr *)&icmpgw, m->m_pkthdr.rcvif, 745 RTF_GATEWAY, V_redirtimeout); 746 } 747 break; 748 749 /* 750 * No kernel processing for the following; 751 * just fall through to send to raw listener. 752 */ 753 case ICMP_ECHOREPLY: 754 case ICMP_ROUTERADVERT: 755 case ICMP_ROUTERSOLICIT: 756 case ICMP_TSTAMPREPLY: 757 case ICMP_IREQREPLY: 758 case ICMP_MASKREPLY: 759 case ICMP_SOURCEQUENCH: 760 default: 761 break; 762 } 763 764 raw: 765 *mp = m; 766 rip_input(mp, offp, proto); 767 return (IPPROTO_DONE); 768 769 freeit: 770 m_freem(m); 771 return (IPPROTO_DONE); 772 } 773 774 /* 775 * Reflect the ip packet back to the source 776 */ 777 static void 778 icmp_reflect(struct mbuf *m) 779 { 780 struct ip *ip = mtod(m, struct ip *); 781 struct ifaddr *ifa; 782 struct ifnet *ifp; 783 struct in_ifaddr *ia; 784 struct in_addr t; 785 struct nhop_object *nh; 786 struct mbuf *opts = NULL; 787 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 788 789 NET_EPOCH_ASSERT(); 790 791 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)) || 792 (IN_EXPERIMENTAL(ntohl(ip->ip_src.s_addr)) && !V_ip_allow_net240) || 793 (IN_ZERONET(ntohl(ip->ip_src.s_addr)) && !V_ip_allow_net0) ) { 794 m_freem(m); /* Bad return address */ 795 ICMPSTAT_INC(icps_badaddr); 796 goto done; /* Ip_output() will check for broadcast */ 797 } 798 799 t = ip->ip_dst; 800 ip->ip_dst = ip->ip_src; 801 802 /* 803 * Source selection for ICMP replies: 804 * 805 * If the incoming packet was addressed directly to one of our 806 * own addresses, use dst as the src for the reply. 807 */ 808 CK_LIST_FOREACH(ia, INADDR_HASH(t.s_addr), ia_hash) { 809 if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr) { 810 t = IA_SIN(ia)->sin_addr; 811 goto match; 812 } 813 } 814 815 /* 816 * If the incoming packet was addressed to one of our broadcast 817 * addresses, use the first non-broadcast address which corresponds 818 * to the incoming interface. 819 */ 820 ifp = m->m_pkthdr.rcvif; 821 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) { 822 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 823 if (ifa->ifa_addr->sa_family != AF_INET) 824 continue; 825 ia = ifatoia(ifa); 826 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == 827 t.s_addr) { 828 t = IA_SIN(ia)->sin_addr; 829 goto match; 830 } 831 } 832 } 833 /* 834 * If the packet was transiting through us, use the address of 835 * the interface the packet came through in. If that interface 836 * doesn't have a suitable IP address, the normal selection 837 * criteria apply. 838 */ 839 if (V_icmp_rfi && ifp != NULL) { 840 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 841 if (ifa->ifa_addr->sa_family != AF_INET) 842 continue; 843 ia = ifatoia(ifa); 844 t = IA_SIN(ia)->sin_addr; 845 goto match; 846 } 847 } 848 /* 849 * If the incoming packet was not addressed directly to us, use 850 * designated interface for icmp replies specified by sysctl 851 * net.inet.icmp.reply_src (default not set). Otherwise continue 852 * with normal source selection. 853 */ 854 if (V_reply_src[0] != '\0' && (ifp = ifunit(V_reply_src))) { 855 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 856 if (ifa->ifa_addr->sa_family != AF_INET) 857 continue; 858 ia = ifatoia(ifa); 859 t = IA_SIN(ia)->sin_addr; 860 goto match; 861 } 862 } 863 /* 864 * If the packet was transiting through us, use the address of 865 * the interface that is the closest to the packet source. 866 * When we don't have a route back to the packet source, stop here 867 * and drop the packet. 868 */ 869 nh = fib4_lookup(M_GETFIB(m), ip->ip_dst, 0, NHR_NONE, 0); 870 if (nh == NULL) { 871 m_freem(m); 872 ICMPSTAT_INC(icps_noroute); 873 goto done; 874 } 875 t = IA_SIN(ifatoia(nh->nh_ifa))->sin_addr; 876 match: 877 #ifdef MAC 878 mac_netinet_icmp_replyinplace(m); 879 #endif 880 ip->ip_src = t; 881 ip->ip_ttl = V_ip_defttl; 882 883 if (optlen > 0) { 884 u_char *cp; 885 int opt, cnt; 886 u_int len; 887 888 /* 889 * Retrieve any source routing from the incoming packet; 890 * add on any record-route or timestamp options. 891 */ 892 cp = (u_char *) (ip + 1); 893 if ((opts = ip_srcroute(m)) == NULL && 894 (opts = m_gethdr(M_NOWAIT, MT_DATA))) { 895 opts->m_len = sizeof(struct in_addr); 896 mtod(opts, struct in_addr *)->s_addr = 0; 897 } 898 if (opts) { 899 #ifdef ICMPPRINTFS 900 if (icmpprintfs) 901 printf("icmp_reflect optlen %d rt %d => ", 902 optlen, opts->m_len); 903 #endif 904 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 905 opt = cp[IPOPT_OPTVAL]; 906 if (opt == IPOPT_EOL) 907 break; 908 if (opt == IPOPT_NOP) 909 len = 1; 910 else { 911 if (cnt < IPOPT_OLEN + sizeof(*cp)) 912 break; 913 len = cp[IPOPT_OLEN]; 914 if (len < IPOPT_OLEN + sizeof(*cp) || 915 len > cnt) 916 break; 917 } 918 /* 919 * Should check for overflow, but it "can't happen" 920 */ 921 if (opt == IPOPT_RR || opt == IPOPT_TS || 922 opt == IPOPT_SECURITY) { 923 bcopy((caddr_t)cp, 924 mtod(opts, caddr_t) + opts->m_len, len); 925 opts->m_len += len; 926 } 927 } 928 /* Terminate & pad, if necessary */ 929 cnt = opts->m_len % 4; 930 if (cnt) { 931 for (; cnt < 4; cnt++) { 932 *(mtod(opts, caddr_t) + opts->m_len) = 933 IPOPT_EOL; 934 opts->m_len++; 935 } 936 } 937 #ifdef ICMPPRINTFS 938 if (icmpprintfs) 939 printf("%d\n", opts->m_len); 940 #endif 941 } 942 ip_stripoptions(m); 943 } 944 m_tag_delete_nonpersistent(m); 945 m->m_flags &= ~(M_BCAST|M_MCAST); 946 icmp_send(m, opts); 947 done: 948 if (opts) 949 (void)m_free(opts); 950 } 951 952 /* 953 * Verifies if redirect message is valid, according to RFC 1122 954 * 955 * @src: sockaddr with address of redirect originator 956 * @dst: sockaddr with destination in question 957 * @gateway: new proposed gateway 958 * 959 * Returns 0 on success. 960 */ 961 static int 962 icmp_verify_redirect_gateway(struct sockaddr_in *src, struct sockaddr_in *dst, 963 struct sockaddr_in *gateway, u_int fibnum) 964 { 965 struct nhop_object *nh; 966 struct ifaddr *ifa; 967 968 NET_EPOCH_ASSERT(); 969 970 /* Verify the gateway is directly reachable. */ 971 if ((ifa = ifa_ifwithnet((struct sockaddr *)gateway, 0, fibnum))==NULL) 972 return (ENETUNREACH); 973 974 /* TODO: fib-aware. */ 975 if (ifa_ifwithaddr_check((struct sockaddr *)gateway)) 976 return (EHOSTUNREACH); 977 978 nh = fib4_lookup(fibnum, dst->sin_addr, 0, NHR_NONE, 0); 979 if (nh == NULL) 980 return (EINVAL); 981 982 /* 983 * If the redirect isn't from our current router for this dst, 984 * it's either old or wrong. If it redirects us to ourselves, 985 * we have a routing loop, perhaps as a result of an interface 986 * going down recently. 987 */ 988 if (!sa_equal((struct sockaddr *)src, &nh->gw_sa)) 989 return (EINVAL); 990 if (nh->nh_ifa != ifa && ifa->ifa_addr->sa_family != AF_LINK) 991 return (EINVAL); 992 993 /* If host route already exists, ignore redirect. */ 994 if (nh->nh_flags & NHF_HOST) 995 return (EEXIST); 996 997 /* If the prefix is directly reachable, ignore redirect. */ 998 if (!(nh->nh_flags & NHF_GATEWAY)) 999 return (EEXIST); 1000 1001 return (0); 1002 } 1003 1004 /* 1005 * Send an icmp packet back to the ip level, 1006 * after supplying a checksum. 1007 */ 1008 static void 1009 icmp_send(struct mbuf *m, struct mbuf *opts) 1010 { 1011 struct ip *ip = mtod(m, struct ip *); 1012 int hlen; 1013 struct icmp *icp; 1014 1015 hlen = ip->ip_hl << 2; 1016 m->m_data += hlen; 1017 m->m_len -= hlen; 1018 icp = mtod(m, struct icmp *); 1019 icp->icmp_cksum = 0; 1020 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 1021 m->m_data -= hlen; 1022 m->m_len += hlen; 1023 m->m_pkthdr.rcvif = (struct ifnet *)0; 1024 #ifdef ICMPPRINTFS 1025 if (icmpprintfs) { 1026 char dstbuf[INET_ADDRSTRLEN]; 1027 char srcbuf[INET_ADDRSTRLEN]; 1028 1029 printf("icmp_send dst %s src %s\n", 1030 inet_ntoa_r(ip->ip_dst, dstbuf), 1031 inet_ntoa_r(ip->ip_src, srcbuf)); 1032 } 1033 #endif 1034 (void) ip_output(m, opts, NULL, 0, NULL, NULL); 1035 } 1036 1037 /* 1038 * Return milliseconds since 00:00 UTC in network format. 1039 */ 1040 uint32_t 1041 iptime(void) 1042 { 1043 struct timeval atv; 1044 u_long t; 1045 1046 getmicrotime(&atv); 1047 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 1048 return (htonl(t)); 1049 } 1050 1051 /* 1052 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1053 * given current value MTU. If DIR is less than zero, a larger plateau 1054 * is returned; otherwise, a smaller value is returned. 1055 */ 1056 int 1057 ip_next_mtu(int mtu, int dir) 1058 { 1059 static int mtutab[] = { 1060 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1280, 1006, 508, 1061 296, 68, 0 1062 }; 1063 int i, size; 1064 1065 size = (sizeof mtutab) / (sizeof mtutab[0]); 1066 if (dir >= 0) { 1067 for (i = 0; i < size; i++) 1068 if (mtu > mtutab[i]) 1069 return mtutab[i]; 1070 } else { 1071 for (i = size - 1; i >= 0; i--) 1072 if (mtu < mtutab[i]) 1073 return mtutab[i]; 1074 if (mtu == mtutab[0]) 1075 return mtutab[0]; 1076 } 1077 return 0; 1078 } 1079 #endif /* INET */ 1080 1081 /* 1082 * badport_bandlim() - check for ICMP bandwidth limit 1083 * 1084 * Return 0 if it is ok to send an ICMP error response, -1 if we have 1085 * hit our bandwidth limit and it is not ok. 1086 * 1087 * If icmplim is <= 0, the feature is disabled and 0 is returned. 1088 * 1089 * For now we separate the TCP and UDP subsystems w/ different 'which' 1090 * values. We may eventually remove this separation (and simplify the 1091 * code further). 1092 * 1093 * Note that the printing of the error message is delayed so we can 1094 * properly print the icmp error rate that the system was trying to do 1095 * (i.e. 22000/100 pps, etc...). This can cause long delays in printing 1096 * the 'final' error, but it doesn't make sense to solve the printing 1097 * delay with more complex code. 1098 */ 1099 VNET_DEFINE_STATIC(struct counter_rate, icmp_rates[BANDLIM_MAX]); 1100 #define V_icmp_rates VNET(icmp_rates) 1101 1102 static const char *icmp_rate_descrs[BANDLIM_MAX] = { 1103 [BANDLIM_ICMP_UNREACH] = "icmp unreach", 1104 [BANDLIM_ICMP_ECHO] = "icmp ping", 1105 [BANDLIM_ICMP_TSTAMP] = "icmp tstamp", 1106 [BANDLIM_RST_CLOSEDPORT] = "closed port RST", 1107 [BANDLIM_RST_OPENPORT] = "open port RST", 1108 [BANDLIM_ICMP6_UNREACH] = "icmp6 unreach", 1109 [BANDLIM_SCTP_OOTB] = "sctp ootb", 1110 }; 1111 1112 static void 1113 icmplim_new_jitter(void) 1114 { 1115 /* 1116 * Adjust limit +/- to jitter the measurement to deny a side-channel 1117 * port scan as in https://dl.acm.org/doi/10.1145/3372297.3417280 1118 */ 1119 if (V_icmplim_jitter > 0) 1120 V_icmplim_curr_jitter = 1121 arc4random_uniform(V_icmplim_jitter * 2 + 1) - 1122 V_icmplim_jitter; 1123 } 1124 1125 static int 1126 sysctl_icmplim_and_jitter(SYSCTL_HANDLER_ARGS) 1127 { 1128 uint32_t new; 1129 int error; 1130 bool lim; 1131 1132 MPASS(oidp->oid_arg1 == &VNET_NAME(icmplim) || 1133 oidp->oid_arg1 == &VNET_NAME(icmplim_jitter)); 1134 1135 lim = (oidp->oid_arg1 == &VNET_NAME(icmplim)); 1136 new = lim ? V_icmplim : V_icmplim_jitter; 1137 error = sysctl_handle_int(oidp, &new, 0, req); 1138 if (error == 0 && req->newptr) { 1139 if (lim) { 1140 if (new != 0 && new <= V_icmplim_jitter) 1141 error = EINVAL; 1142 else 1143 V_icmplim = new; 1144 } else { 1145 if (new >= V_icmplim) 1146 error = EINVAL; 1147 else { 1148 V_icmplim_jitter = new; 1149 icmplim_new_jitter(); 1150 } 1151 } 1152 } 1153 MPASS(V_icmplim + V_icmplim_curr_jitter >= 0); 1154 1155 return (error); 1156 } 1157 1158 static void 1159 icmp_bandlimit_init(void) 1160 { 1161 1162 for (int i = 0; i < BANDLIM_MAX; i++) { 1163 V_icmp_rates[i].cr_rate = counter_u64_alloc(M_WAITOK); 1164 V_icmp_rates[i].cr_ticks = ticks; 1165 } 1166 icmplim_new_jitter(); 1167 } 1168 VNET_SYSINIT(icmp_bandlimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, 1169 icmp_bandlimit_init, NULL); 1170 1171 #ifdef VIMAGE 1172 static void 1173 icmp_bandlimit_uninit(void) 1174 { 1175 1176 for (int i = 0; i < BANDLIM_MAX; i++) 1177 counter_u64_free(V_icmp_rates[i].cr_rate); 1178 } 1179 VNET_SYSUNINIT(icmp_bandlimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, 1180 icmp_bandlimit_uninit, NULL); 1181 #endif 1182 1183 int 1184 badport_bandlim(int which) 1185 { 1186 int64_t pps; 1187 1188 if (V_icmplim == 0 || which == BANDLIM_UNLIMITED) 1189 return (0); 1190 1191 KASSERT(which >= 0 && which < BANDLIM_MAX, 1192 ("%s: which %d", __func__, which)); 1193 1194 pps = counter_ratecheck(&V_icmp_rates[which], V_icmplim + 1195 V_icmplim_curr_jitter); 1196 if (pps > 0) { 1197 if (V_icmplim_output) 1198 log(LOG_NOTICE, 1199 "Limiting %s response from %jd to %d packets/sec\n", 1200 icmp_rate_descrs[which], (intmax_t )pps, 1201 V_icmplim + V_icmplim_curr_jitter); 1202 icmplim_new_jitter(); 1203 } 1204 if (pps == -1) 1205 return (-1); 1206 return (0); 1207 } 1208