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 32 #include <sys/cdefs.h> 33 #include "opt_inet.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/mbuf.h> 38 #include <sys/protosw.h> 39 #include <sys/socket.h> 40 #include <sys/time.h> 41 #include <sys/kernel.h> 42 #include <sys/lock.h> 43 #include <sys/sysctl.h> 44 #include <sys/syslog.h> 45 46 #include <net/if.h> 47 #include <net/if_var.h> 48 #include <net/if_private.h> 49 #include <net/if_types.h> 50 #include <net/route.h> 51 #include <net/route/route_ctl.h> 52 #include <net/route/nhop.h> 53 #include <net/vnet.h> 54 55 #include <netinet/in.h> 56 #include <netinet/in_fib.h> 57 #include <netinet/in_pcb.h> 58 #include <netinet/in_systm.h> 59 #include <netinet/in_var.h> 60 #include <netinet/ip.h> 61 #include <netinet/ip_icmp.h> 62 #include <netinet/ip_var.h> 63 #include <netinet/ip_options.h> 64 #include <netinet/sctp.h> 65 #include <netinet/tcp.h> 66 #include <netinet/tcpip.h> 67 #include <netinet/icmp_var.h> 68 69 #ifdef INET 70 71 #include <machine/in_cksum.h> 72 73 #include <security/mac/mac_framework.h> 74 #endif /* INET */ 75 76 extern ipproto_ctlinput_t *ip_ctlprotox[]; 77 78 /* 79 * ICMP routines: error generation, receive packet processing, and 80 * routines to turnaround packets back to the originator, and 81 * host table maintenance routines. 82 */ 83 static int sysctl_icmplim_and_jitter(SYSCTL_HANDLER_ARGS); 84 VNET_DEFINE_STATIC(u_int, icmplim) = 200; 85 #define V_icmplim VNET(icmplim) 86 SYSCTL_PROC(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLTYPE_UINT | 87 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmplim), 0, 88 &sysctl_icmplim_and_jitter, "IU", 89 "Maximum number of ICMP responses per second"); 90 91 VNET_DEFINE_STATIC(int, icmplim_curr_jitter[BANDLIM_MAX]) = {0}; 92 #define V_icmplim_curr_jitter VNET(icmplim_curr_jitter) 93 VNET_DEFINE_STATIC(u_int, icmplim_jitter) = 16; 94 #define V_icmplim_jitter VNET(icmplim_jitter) 95 SYSCTL_PROC(_net_inet_icmp, OID_AUTO, icmplim_jitter, CTLTYPE_UINT | 96 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmplim_jitter), 0, 97 &sysctl_icmplim_and_jitter, "IU", 98 "Random icmplim jitter adjustment limit"); 99 100 VNET_DEFINE_STATIC(int, icmplim_output) = 1; 101 #define V_icmplim_output VNET(icmplim_output) 102 SYSCTL_INT(_net_inet_icmp, OID_AUTO, icmplim_output, CTLFLAG_VNET | CTLFLAG_RW, 103 &VNET_NAME(icmplim_output), 0, 104 "Enable logging of ICMP response rate limiting"); 105 106 #ifdef INET 107 VNET_PCPUSTAT_DEFINE(struct icmpstat, icmpstat); 108 VNET_PCPUSTAT_SYSINIT(icmpstat); 109 SYSCTL_VNET_PCPUSTAT(_net_inet_icmp, ICMPCTL_STATS, stats, struct icmpstat, 110 icmpstat, "ICMP statistics (struct icmpstat, netinet/icmp_var.h)"); 111 112 #ifdef VIMAGE 113 VNET_PCPUSTAT_SYSUNINIT(icmpstat); 114 #endif /* VIMAGE */ 115 116 VNET_DEFINE_STATIC(int, icmpmaskrepl) = 0; 117 #define V_icmpmaskrepl VNET(icmpmaskrepl) 118 SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_VNET | CTLFLAG_RW, 119 &VNET_NAME(icmpmaskrepl), 0, 120 "Reply to ICMP Address Mask Request packets"); 121 122 VNET_DEFINE_STATIC(u_int, icmpmaskfake) = 0; 123 #define V_icmpmaskfake VNET(icmpmaskfake) 124 SYSCTL_UINT(_net_inet_icmp, OID_AUTO, maskfake, CTLFLAG_VNET | CTLFLAG_RW, 125 &VNET_NAME(icmpmaskfake), 0, 126 "Fake reply to ICMP Address Mask Request packets"); 127 128 VNET_DEFINE(int, drop_redirect) = 0; 129 #define V_drop_redirect VNET(drop_redirect) 130 SYSCTL_INT(_net_inet_icmp, OID_AUTO, drop_redirect, CTLFLAG_VNET | CTLFLAG_RW, 131 &VNET_NAME(drop_redirect), 0, 132 "Ignore ICMP redirects"); 133 134 VNET_DEFINE_STATIC(int, log_redirect) = 0; 135 #define V_log_redirect VNET(log_redirect) 136 SYSCTL_INT(_net_inet_icmp, OID_AUTO, log_redirect, CTLFLAG_VNET | CTLFLAG_RW, 137 &VNET_NAME(log_redirect), 0, 138 "Log ICMP redirects to the console"); 139 140 VNET_DEFINE_STATIC(int, redirtimeout) = 60 * 10; /* 10 minutes */ 141 #define V_redirtimeout VNET(redirtimeout) 142 SYSCTL_INT(_net_inet_icmp, OID_AUTO, redirtimeout, CTLFLAG_VNET | CTLFLAG_RW, 143 &VNET_NAME(redirtimeout), 0, 144 "Delay in seconds before expiring redirect route"); 145 146 VNET_DEFINE_STATIC(char, reply_src[IFNAMSIZ]); 147 #define V_reply_src VNET(reply_src) 148 SYSCTL_STRING(_net_inet_icmp, OID_AUTO, reply_src, CTLFLAG_VNET | CTLFLAG_RW, 149 &VNET_NAME(reply_src), IFNAMSIZ, 150 "ICMP reply source for non-local packets"); 151 152 VNET_DEFINE_STATIC(int, icmp_rfi) = 0; 153 #define V_icmp_rfi VNET(icmp_rfi) 154 SYSCTL_INT(_net_inet_icmp, OID_AUTO, reply_from_interface, CTLFLAG_VNET | CTLFLAG_RW, 155 &VNET_NAME(icmp_rfi), 0, 156 "ICMP reply from incoming interface for non-local packets"); 157 /* Router requirements RFC 1812 section 4.3.2.3 requires 576 - 28. */ 158 VNET_DEFINE_STATIC(int, icmp_quotelen) = 548; 159 #define V_icmp_quotelen VNET(icmp_quotelen) 160 SYSCTL_INT(_net_inet_icmp, OID_AUTO, quotelen, CTLFLAG_VNET | CTLFLAG_RW, 161 &VNET_NAME(icmp_quotelen), 0, 162 "Number of bytes from original packet to quote in ICMP reply"); 163 164 VNET_DEFINE_STATIC(int, icmpbmcastecho) = 0; 165 #define V_icmpbmcastecho VNET(icmpbmcastecho) 166 SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_VNET | CTLFLAG_RW, 167 &VNET_NAME(icmpbmcastecho), 0, 168 "Reply to multicast ICMP Echo Request and Timestamp packets"); 169 170 VNET_DEFINE_STATIC(int, icmptstamprepl) = 1; 171 #define V_icmptstamprepl VNET(icmptstamprepl) 172 SYSCTL_INT(_net_inet_icmp, OID_AUTO, tstamprepl, CTLFLAG_VNET | CTLFLAG_RW, 173 &VNET_NAME(icmptstamprepl), 0, 174 "Respond to ICMP Timestamp packets"); 175 176 VNET_DEFINE_STATIC(int, error_keeptags) = 0; 177 #define V_error_keeptags VNET(error_keeptags) 178 SYSCTL_INT(_net_inet_icmp, OID_AUTO, error_keeptags, CTLFLAG_VNET | CTLFLAG_RW, 179 &VNET_NAME(error_keeptags), 0, 180 "ICMP error response keeps copy of mbuf_tags of original packet"); 181 182 #ifdef ICMPPRINTFS 183 int icmpprintfs = 0; 184 #endif 185 186 static void icmp_reflect(struct mbuf *); 187 static void icmp_send(struct mbuf *, struct mbuf *); 188 static int icmp_verify_redirect_gateway(struct sockaddr_in *, 189 struct sockaddr_in *, struct sockaddr_in *, u_int); 190 191 /* 192 * Kernel module interface for updating icmpstat. The argument is an index 193 * into icmpstat treated as an array of u_long. While this encodes the 194 * general layout of icmpstat into the caller, it doesn't encode its 195 * location, so that future changes to add, for example, per-CPU stats 196 * support won't cause binary compatibility problems for kernel modules. 197 */ 198 void 199 kmod_icmpstat_inc(int statnum) 200 { 201 202 counter_u64_add(VNET(icmpstat)[statnum], 1); 203 } 204 205 /* 206 * Generate an error packet of type error 207 * in response to bad packet ip. 208 */ 209 void 210 icmp_error(struct mbuf *n, int type, int code, uint32_t dest, int mtu) 211 { 212 struct ip *oip, *nip; 213 struct icmp *icp; 214 struct mbuf *m; 215 unsigned icmplen, icmpelen, nlen, oiphlen; 216 217 KASSERT((u_int)type <= ICMP_MAXTYPE, ("%s: illegal ICMP type", 218 __func__)); 219 220 if (type != ICMP_REDIRECT) 221 ICMPSTAT_INC(icps_error); 222 /* 223 * Don't send error: 224 * if the original packet was encrypted. 225 * if not the first fragment of message. 226 * in response to a multicast or broadcast packet. 227 * if the old packet protocol was an ICMP error message. 228 */ 229 if (n->m_flags & M_DECRYPTED) 230 goto freeit; 231 if (n->m_flags & (M_BCAST|M_MCAST)) 232 goto freeit; 233 234 /* Drop if IP header plus 8 bytes is not contiguous in first mbuf. */ 235 if (n->m_len < sizeof(struct ip) + ICMP_MINLEN) 236 goto freeit; 237 oip = mtod(n, struct ip *); 238 oiphlen = oip->ip_hl << 2; 239 if (n->m_len < oiphlen + ICMP_MINLEN) 240 goto freeit; 241 #ifdef ICMPPRINTFS 242 if (icmpprintfs) 243 printf("icmp_error(%p, %x, %d)\n", oip, type, code); 244 #endif 245 if (oip->ip_off & htons(~(IP_MF|IP_DF))) 246 goto freeit; 247 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 248 !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + 249 oiphlen))->icmp_type)) { 250 ICMPSTAT_INC(icps_oldicmp); 251 goto freeit; 252 } 253 /* 254 * Calculate length to quote from original packet and 255 * prevent the ICMP mbuf from overflowing. 256 * Unfortunately this is non-trivial since ip_forward() 257 * sends us truncated packets. 258 */ 259 nlen = m_length(n, NULL); 260 if (oip->ip_p == IPPROTO_TCP) { 261 struct tcphdr *th; 262 int tcphlen; 263 264 if (oiphlen + sizeof(struct tcphdr) > n->m_len && 265 n->m_next == NULL) 266 goto stdreply; 267 if (n->m_len < oiphlen + sizeof(struct tcphdr) && 268 (n = m_pullup(n, oiphlen + sizeof(struct tcphdr))) == NULL) 269 goto freeit; 270 oip = mtod(n, struct ip *); 271 th = mtodo(n, oiphlen); 272 tcphlen = th->th_off << 2; 273 if (tcphlen < sizeof(struct tcphdr)) 274 goto freeit; 275 if (ntohs(oip->ip_len) < oiphlen + tcphlen) 276 goto freeit; 277 if (oiphlen + tcphlen > n->m_len && n->m_next == NULL) 278 goto stdreply; 279 if (n->m_len < oiphlen + tcphlen && 280 (n = m_pullup(n, oiphlen + tcphlen)) == NULL) 281 goto freeit; 282 oip = mtod(n, struct ip *); 283 icmpelen = max(tcphlen, min(V_icmp_quotelen, 284 ntohs(oip->ip_len) - oiphlen)); 285 } else if (oip->ip_p == IPPROTO_SCTP) { 286 struct sctphdr *sh; 287 struct sctp_chunkhdr *ch; 288 289 if (ntohs(oip->ip_len) < oiphlen + sizeof(struct sctphdr)) 290 goto stdreply; 291 if (oiphlen + sizeof(struct sctphdr) > n->m_len && 292 n->m_next == NULL) 293 goto stdreply; 294 if (n->m_len < oiphlen + sizeof(struct sctphdr) && 295 (n = m_pullup(n, oiphlen + sizeof(struct sctphdr))) == NULL) 296 goto freeit; 297 oip = mtod(n, struct ip *); 298 icmpelen = max(sizeof(struct sctphdr), 299 min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen)); 300 sh = mtodo(n, oiphlen); 301 if (ntohl(sh->v_tag) == 0 && 302 ntohs(oip->ip_len) >= oiphlen + 303 sizeof(struct sctphdr) + 8 && 304 (n->m_len >= oiphlen + sizeof(struct sctphdr) + 8 || 305 n->m_next != NULL)) { 306 if (n->m_len < oiphlen + sizeof(struct sctphdr) + 8 && 307 (n = m_pullup(n, oiphlen + 308 sizeof(struct sctphdr) + 8)) == NULL) 309 goto freeit; 310 oip = mtod(n, struct ip *); 311 sh = mtodo(n, oiphlen); 312 ch = (struct sctp_chunkhdr *)(sh + 1); 313 if (ch->chunk_type == SCTP_INITIATION) { 314 icmpelen = max(sizeof(struct sctphdr) + 8, 315 min(V_icmp_quotelen, ntohs(oip->ip_len) - 316 oiphlen)); 317 } 318 } 319 } else 320 stdreply: icmpelen = max(8, min(V_icmp_quotelen, ntohs(oip->ip_len) - 321 oiphlen)); 322 323 icmplen = min(oiphlen + icmpelen, nlen); 324 if (icmplen < sizeof(struct ip)) 325 goto freeit; 326 327 if (MHLEN > sizeof(struct ip) + ICMP_MINLEN + icmplen) 328 m = m_gethdr(M_NOWAIT, MT_DATA); 329 else 330 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 331 if (m == NULL) 332 goto freeit; 333 #ifdef MAC 334 mac_netinet_icmp_reply(n, m); 335 #endif 336 icmplen = min(icmplen, M_TRAILINGSPACE(m) - 337 sizeof(struct ip) - ICMP_MINLEN); 338 m_align(m, sizeof(struct ip) + ICMP_MINLEN + icmplen); 339 m->m_data += sizeof(struct ip); 340 m->m_len = ICMP_MINLEN + icmplen; 341 342 /* XXX MRT make the outgoing packet use the same FIB 343 * that was associated with the incoming packet 344 */ 345 M_SETFIB(m, M_GETFIB(n)); 346 icp = mtod(m, struct icmp *); 347 ICMPSTAT_INC2(icps_outhist, type); 348 icp->icmp_type = type; 349 if (type == ICMP_REDIRECT) 350 icp->icmp_gwaddr.s_addr = dest; 351 else { 352 icp->icmp_void = 0; 353 /* 354 * The following assignments assume an overlay with the 355 * just zeroed icmp_void field. 356 */ 357 if (type == ICMP_PARAMPROB) { 358 icp->icmp_pptr = code; 359 code = 0; 360 } else if (type == ICMP_UNREACH && 361 code == ICMP_UNREACH_NEEDFRAG && mtu) { 362 icp->icmp_nextmtu = htons(mtu); 363 } 364 } 365 icp->icmp_code = code; 366 367 /* 368 * Copy the quotation into ICMP message and 369 * convert quoted IP header back to network representation. 370 */ 371 m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip); 372 nip = &icp->icmp_ip; 373 374 /* 375 * Set up ICMP message mbuf and copy old IP header (without options 376 * in front of ICMP message. 377 * If the original mbuf was meant to bypass the firewall, the error 378 * reply should bypass as well. 379 */ 380 m->m_flags |= n->m_flags & M_SKIP_FIREWALL; 381 KASSERT(M_LEADINGSPACE(m) >= sizeof(struct ip), 382 ("insufficient space for ip header")); 383 m->m_data -= sizeof(struct ip); 384 m->m_len += sizeof(struct ip); 385 m->m_pkthdr.len = m->m_len; 386 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif; 387 nip = mtod(m, struct ip *); 388 bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip)); 389 nip->ip_len = htons(m->m_len); 390 nip->ip_v = IPVERSION; 391 nip->ip_hl = 5; 392 nip->ip_p = IPPROTO_ICMP; 393 nip->ip_tos = 0; 394 395 if (V_error_keeptags) 396 m_tag_copy_chain(m, n, M_NOWAIT); 397 398 icmp_reflect(m); 399 400 freeit: 401 m_freem(n); 402 } 403 404 int 405 icmp_errmap(const struct icmp *icp) 406 { 407 408 switch (icp->icmp_type) { 409 case ICMP_UNREACH: 410 switch (icp->icmp_code) { 411 case ICMP_UNREACH_NET: 412 case ICMP_UNREACH_HOST: 413 case ICMP_UNREACH_SRCFAIL: 414 case ICMP_UNREACH_NET_UNKNOWN: 415 case ICMP_UNREACH_HOST_UNKNOWN: 416 case ICMP_UNREACH_ISOLATED: 417 case ICMP_UNREACH_TOSNET: 418 case ICMP_UNREACH_TOSHOST: 419 case ICMP_UNREACH_HOST_PRECEDENCE: 420 case ICMP_UNREACH_PRECEDENCE_CUTOFF: 421 return (EHOSTUNREACH); 422 case ICMP_UNREACH_NEEDFRAG: 423 return (EMSGSIZE); 424 case ICMP_UNREACH_PROTOCOL: 425 case ICMP_UNREACH_PORT: 426 case ICMP_UNREACH_NET_PROHIB: 427 case ICMP_UNREACH_HOST_PROHIB: 428 case ICMP_UNREACH_FILTER_PROHIB: 429 return (ECONNREFUSED); 430 default: 431 return (0); 432 } 433 case ICMP_TIMXCEED: 434 switch (icp->icmp_code) { 435 case ICMP_TIMXCEED_INTRANS: 436 return (EHOSTUNREACH); 437 default: 438 return (0); 439 } 440 case ICMP_PARAMPROB: 441 switch (icp->icmp_code) { 442 case ICMP_PARAMPROB_ERRATPTR: 443 case ICMP_PARAMPROB_OPTABSENT: 444 return (ENOPROTOOPT); 445 default: 446 return (0); 447 } 448 default: 449 return (0); 450 } 451 } 452 453 /* 454 * Process a received ICMP message. 455 */ 456 int 457 icmp_input(struct mbuf **mp, int *offp, int proto) 458 { 459 struct icmp *icp; 460 struct in_ifaddr *ia; 461 struct mbuf *m = *mp; 462 struct ip *ip = mtod(m, struct ip *); 463 struct sockaddr_in icmpsrc, icmpdst, icmpgw; 464 int hlen = *offp; 465 int icmplen = ntohs(ip->ip_len) - *offp; 466 int i, code; 467 int fibnum; 468 469 NET_EPOCH_ASSERT(); 470 471 *mp = NULL; 472 473 /* 474 * Locate icmp structure in mbuf, and check 475 * that not corrupted and of at least minimum length. 476 */ 477 #ifdef ICMPPRINTFS 478 if (icmpprintfs) { 479 char srcbuf[INET_ADDRSTRLEN]; 480 char dstbuf[INET_ADDRSTRLEN]; 481 482 printf("icmp_input from %s to %s, len %d\n", 483 inet_ntoa_r(ip->ip_src, srcbuf), 484 inet_ntoa_r(ip->ip_dst, dstbuf), icmplen); 485 } 486 #endif 487 if (icmplen < ICMP_MINLEN) { 488 ICMPSTAT_INC(icps_tooshort); 489 goto freeit; 490 } 491 i = hlen + min(icmplen, ICMP_ADVLENMIN); 492 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) { 493 ICMPSTAT_INC(icps_tooshort); 494 return (IPPROTO_DONE); 495 } 496 ip = mtod(m, struct ip *); 497 m->m_len -= hlen; 498 m->m_data += hlen; 499 icp = mtod(m, struct icmp *); 500 if (in_cksum(m, icmplen)) { 501 ICMPSTAT_INC(icps_checksum); 502 goto freeit; 503 } 504 m->m_len += hlen; 505 m->m_data -= hlen; 506 507 #ifdef ICMPPRINTFS 508 if (icmpprintfs) 509 printf("icmp_input, type %d code %d\n", icp->icmp_type, 510 icp->icmp_code); 511 #endif 512 513 /* 514 * Message type specific processing. 515 */ 516 if (icp->icmp_type > ICMP_MAXTYPE) 517 goto raw; 518 519 /* Initialize */ 520 bzero(&icmpsrc, sizeof(icmpsrc)); 521 icmpsrc.sin_len = sizeof(struct sockaddr_in); 522 icmpsrc.sin_family = AF_INET; 523 bzero(&icmpdst, sizeof(icmpdst)); 524 icmpdst.sin_len = sizeof(struct sockaddr_in); 525 icmpdst.sin_family = AF_INET; 526 bzero(&icmpgw, sizeof(icmpgw)); 527 icmpgw.sin_len = sizeof(struct sockaddr_in); 528 icmpgw.sin_family = AF_INET; 529 530 ICMPSTAT_INC2(icps_inhist, icp->icmp_type); 531 code = icp->icmp_code; 532 switch (icp->icmp_type) { 533 case ICMP_UNREACH: 534 if (code > ICMP_UNREACH_PRECEDENCE_CUTOFF) 535 goto badcode; 536 else 537 goto deliver; 538 539 case ICMP_TIMXCEED: 540 if (code > ICMP_TIMXCEED_REASS) 541 goto badcode; 542 else 543 goto deliver; 544 545 case ICMP_PARAMPROB: 546 if (code > ICMP_PARAMPROB_LENGTH) 547 goto badcode; 548 549 deliver: 550 /* 551 * Problem with datagram; advise higher level routines. 552 */ 553 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 554 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 555 ICMPSTAT_INC(icps_badlen); 556 goto freeit; 557 } 558 /* Discard ICMP's in response to multicast packets */ 559 if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr))) 560 goto badcode; 561 /* Filter out responses to INADDR_ANY, protocols ignore it. */ 562 if (icp->icmp_ip.ip_dst.s_addr == INADDR_ANY || 563 icp->icmp_ip.ip_src.s_addr == INADDR_ANY) 564 goto freeit; 565 #ifdef ICMPPRINTFS 566 if (icmpprintfs) 567 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 568 #endif 569 /* 570 * XXX if the packet contains [IPv4 AH TCP], we can't make a 571 * notification to TCP layer. 572 */ 573 i = sizeof(struct ip) + min(icmplen, ICMP_ADVLENPREF(icp)); 574 ip_stripoptions(m); 575 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) { 576 /* This should actually not happen */ 577 ICMPSTAT_INC(icps_tooshort); 578 return (IPPROTO_DONE); 579 } 580 ip = mtod(m, struct ip *); 581 icp = (struct icmp *)(ip + 1); 582 /* 583 * The upper layer handler can rely on: 584 * - The outer IP header has no options. 585 * - The outer IP header, the ICMP header, the inner IP header, 586 * and the first n bytes of the inner payload are contiguous. 587 * n is at least 8, but might be larger based on 588 * ICMP_ADVLENPREF. See its definition in ip_icmp.h. 589 */ 590 if (ip_ctlprotox[icp->icmp_ip.ip_p] != NULL) 591 ip_ctlprotox[icp->icmp_ip.ip_p](icp); 592 break; 593 594 badcode: 595 ICMPSTAT_INC(icps_badcode); 596 break; 597 598 case ICMP_ECHO: 599 if (!V_icmpbmcastecho 600 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 601 ICMPSTAT_INC(icps_bmcastecho); 602 break; 603 } 604 if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0) 605 goto freeit; 606 icp->icmp_type = ICMP_ECHOREPLY; 607 goto reflect; 608 609 case ICMP_TSTAMP: 610 if (V_icmptstamprepl == 0) 611 break; 612 if (!V_icmpbmcastecho 613 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 614 ICMPSTAT_INC(icps_bmcasttstamp); 615 break; 616 } 617 if (icmplen < ICMP_TSLEN) { 618 ICMPSTAT_INC(icps_badlen); 619 break; 620 } 621 if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0) 622 goto freeit; 623 icp->icmp_type = ICMP_TSTAMPREPLY; 624 icp->icmp_rtime = iptime(); 625 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 626 goto reflect; 627 628 case ICMP_MASKREQ: 629 if (V_icmpmaskrepl == 0) 630 break; 631 /* 632 * We are not able to respond with all ones broadcast 633 * unless we receive it over a point-to-point interface. 634 */ 635 if (icmplen < ICMP_MASKLEN) 636 break; 637 if (in_broadcast(ip->ip_dst)) 638 icmpdst.sin_addr = ip->ip_src; 639 else 640 icmpdst.sin_addr = ip->ip_dst; 641 ia = (struct in_ifaddr *)ifaof_ifpforaddr( 642 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif); 643 if (ia == NULL) 644 break; 645 if (ia->ia_ifp == NULL) 646 break; 647 icp->icmp_type = ICMP_MASKREPLY; 648 if (V_icmpmaskfake == 0) 649 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 650 else 651 icp->icmp_mask = V_icmpmaskfake; 652 if (ip->ip_src.s_addr == 0) { 653 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 654 ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr; 655 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 656 ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr; 657 } 658 reflect: 659 ICMPSTAT_INC(icps_reflect); 660 ICMPSTAT_INC2(icps_outhist, icp->icmp_type); 661 icmp_reflect(m); 662 return (IPPROTO_DONE); 663 664 case ICMP_REDIRECT: 665 if (V_log_redirect) { 666 u_long src, dst, gw; 667 668 src = ntohl(ip->ip_src.s_addr); 669 dst = ntohl(icp->icmp_ip.ip_dst.s_addr); 670 gw = ntohl(icp->icmp_gwaddr.s_addr); 671 printf("icmp redirect from %d.%d.%d.%d: " 672 "%d.%d.%d.%d => %d.%d.%d.%d\n", 673 (int)(src >> 24), (int)((src >> 16) & 0xff), 674 (int)((src >> 8) & 0xff), (int)(src & 0xff), 675 (int)(dst >> 24), (int)((dst >> 16) & 0xff), 676 (int)((dst >> 8) & 0xff), (int)(dst & 0xff), 677 (int)(gw >> 24), (int)((gw >> 16) & 0xff), 678 (int)((gw >> 8) & 0xff), (int)(gw & 0xff)); 679 } 680 /* 681 * RFC1812 says we must ignore ICMP redirects if we 682 * are acting as router. 683 */ 684 if (V_drop_redirect || V_ipforwarding) 685 break; 686 if (code > 3) 687 goto badcode; 688 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 689 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 690 ICMPSTAT_INC(icps_badlen); 691 break; 692 } 693 /* 694 * Short circuit routing redirects to force 695 * immediate change in the kernel's routing 696 * tables. The message is also handed to anyone 697 * listening on a raw socket (e.g. the routing 698 * daemon for use in updating its tables). 699 */ 700 icmpgw.sin_addr = ip->ip_src; 701 icmpdst.sin_addr = icp->icmp_gwaddr; 702 #ifdef ICMPPRINTFS 703 if (icmpprintfs) { 704 char dstbuf[INET_ADDRSTRLEN]; 705 char gwbuf[INET_ADDRSTRLEN]; 706 707 printf("redirect dst %s to %s\n", 708 inet_ntoa_r(icp->icmp_ip.ip_dst, dstbuf), 709 inet_ntoa_r(icp->icmp_gwaddr, gwbuf)); 710 } 711 #endif 712 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 713 714 /* 715 * RFC 1122 says network (code 0,2) redirects SHOULD 716 * be treated identically to the host redirects. 717 * Given that, ignore network masks. 718 */ 719 720 /* 721 * Variable values: 722 * icmpsrc: route destination 723 * icmpdst: route gateway 724 * icmpgw: message source 725 */ 726 727 if (icmp_verify_redirect_gateway(&icmpgw, &icmpsrc, &icmpdst, 728 M_GETFIB(m)) != 0) { 729 /* TODO: increment bad redirects here */ 730 break; 731 } 732 733 for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) { 734 rib_add_redirect(fibnum, (struct sockaddr *)&icmpsrc, 735 (struct sockaddr *)&icmpdst, 736 (struct sockaddr *)&icmpgw, m->m_pkthdr.rcvif, 737 RTF_GATEWAY, V_redirtimeout); 738 } 739 break; 740 741 /* 742 * No kernel processing for the following; 743 * just fall through to send to raw listener. 744 */ 745 case ICMP_ECHOREPLY: 746 case ICMP_ROUTERADVERT: 747 case ICMP_ROUTERSOLICIT: 748 case ICMP_TSTAMPREPLY: 749 case ICMP_IREQREPLY: 750 case ICMP_MASKREPLY: 751 case ICMP_SOURCEQUENCH: 752 default: 753 break; 754 } 755 756 raw: 757 *mp = m; 758 rip_input(mp, offp, proto); 759 return (IPPROTO_DONE); 760 761 freeit: 762 m_freem(m); 763 return (IPPROTO_DONE); 764 } 765 766 /* 767 * Reflect the ip packet back to the source 768 */ 769 static void 770 icmp_reflect(struct mbuf *m) 771 { 772 struct ip *ip = mtod(m, struct ip *); 773 struct ifaddr *ifa; 774 struct ifnet *ifp; 775 struct in_ifaddr *ia; 776 struct in_addr t; 777 struct nhop_object *nh; 778 struct mbuf *opts = NULL; 779 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 780 781 NET_EPOCH_ASSERT(); 782 783 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)) || 784 (IN_EXPERIMENTAL(ntohl(ip->ip_src.s_addr)) && !V_ip_allow_net240) || 785 (IN_ZERONET(ntohl(ip->ip_src.s_addr)) && !V_ip_allow_net0) || 786 in_nullhost(ip->ip_src) ) { 787 m_freem(m); /* Bad return address */ 788 ICMPSTAT_INC(icps_badaddr); 789 goto done; /* ip_output() will check for broadcast */ 790 } 791 792 t = ip->ip_dst; 793 ip->ip_dst = ip->ip_src; 794 795 /* 796 * Source selection for ICMP replies: 797 * 798 * If the incoming packet was addressed directly to one of our 799 * own addresses, use dst as the src for the reply. 800 */ 801 CK_LIST_FOREACH(ia, INADDR_HASH(t.s_addr), ia_hash) { 802 if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr) { 803 t = IA_SIN(ia)->sin_addr; 804 goto match; 805 } 806 } 807 808 /* 809 * If the incoming packet was addressed to one of our broadcast 810 * addresses, use the first non-broadcast address which corresponds 811 * to the incoming interface. 812 */ 813 ifp = m->m_pkthdr.rcvif; 814 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) { 815 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 816 if (ifa->ifa_addr->sa_family != AF_INET) 817 continue; 818 ia = ifatoia(ifa); 819 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == 820 t.s_addr) { 821 t = IA_SIN(ia)->sin_addr; 822 goto match; 823 } 824 } 825 } 826 /* 827 * If the packet was transiting through us, use the address of 828 * the interface the packet came through in. If that interface 829 * doesn't have a suitable IP address, the normal selection 830 * criteria apply. 831 */ 832 if (V_icmp_rfi && ifp != NULL) { 833 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 834 if (ifa->ifa_addr->sa_family != AF_INET) 835 continue; 836 ia = ifatoia(ifa); 837 t = IA_SIN(ia)->sin_addr; 838 goto match; 839 } 840 } 841 /* 842 * If the incoming packet was not addressed directly to us, use 843 * designated interface for icmp replies specified by sysctl 844 * net.inet.icmp.reply_src (default not set). Otherwise continue 845 * with normal source selection. 846 */ 847 if (V_reply_src[0] != '\0' && (ifp = ifunit(V_reply_src))) { 848 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 849 if (ifa->ifa_addr->sa_family != AF_INET) 850 continue; 851 ia = ifatoia(ifa); 852 t = IA_SIN(ia)->sin_addr; 853 goto match; 854 } 855 } 856 /* 857 * If the packet was transiting through us, use the address of 858 * the interface that is the closest to the packet source. 859 * When we don't have a route back to the packet source, stop here 860 * and drop the packet. 861 */ 862 nh = fib4_lookup(M_GETFIB(m), ip->ip_dst, 0, NHR_NONE, 0); 863 if (nh == NULL) { 864 m_freem(m); 865 ICMPSTAT_INC(icps_noroute); 866 goto done; 867 } 868 t = IA_SIN(ifatoia(nh->nh_ifa))->sin_addr; 869 match: 870 #ifdef MAC 871 mac_netinet_icmp_replyinplace(m); 872 #endif 873 ip->ip_src = t; 874 /* ip->ip_tos will be reflected. */ 875 ip->ip_off = htons(0); 876 ip->ip_ttl = V_ip_defttl; 877 878 if (optlen > 0) { 879 u_char *cp; 880 int opt, cnt; 881 u_int len; 882 883 /* 884 * Retrieve any source routing from the incoming packet; 885 * add on any record-route or timestamp options. 886 */ 887 cp = (u_char *) (ip + 1); 888 if ((opts = ip_srcroute(m)) == NULL && 889 (opts = m_gethdr(M_NOWAIT, MT_DATA))) { 890 opts->m_len = sizeof(struct in_addr); 891 mtod(opts, struct in_addr *)->s_addr = 0; 892 } 893 if (opts) { 894 #ifdef ICMPPRINTFS 895 if (icmpprintfs) 896 printf("icmp_reflect optlen %d rt %d => ", 897 optlen, opts->m_len); 898 #endif 899 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 900 opt = cp[IPOPT_OPTVAL]; 901 if (opt == IPOPT_EOL) 902 break; 903 if (opt == IPOPT_NOP) 904 len = 1; 905 else { 906 if (cnt < IPOPT_OLEN + sizeof(*cp)) 907 break; 908 len = cp[IPOPT_OLEN]; 909 if (len < IPOPT_OLEN + sizeof(*cp) || 910 len > cnt) 911 break; 912 } 913 /* 914 * Should check for overflow, but it "can't happen" 915 */ 916 if (opt == IPOPT_RR || opt == IPOPT_TS || 917 opt == IPOPT_SECURITY) { 918 bcopy((caddr_t)cp, 919 mtod(opts, caddr_t) + opts->m_len, len); 920 opts->m_len += len; 921 } 922 } 923 /* Terminate & pad, if necessary */ 924 cnt = opts->m_len % 4; 925 if (cnt) { 926 for (; cnt < 4; cnt++) { 927 *(mtod(opts, caddr_t) + opts->m_len) = 928 IPOPT_EOL; 929 opts->m_len++; 930 } 931 } 932 #ifdef ICMPPRINTFS 933 if (icmpprintfs) 934 printf("%d\n", opts->m_len); 935 #endif 936 } 937 ip_stripoptions(m); 938 } 939 m_tag_delete_nonpersistent(m); 940 m->m_flags &= ~(M_BCAST|M_MCAST); 941 icmp_send(m, opts); 942 done: 943 if (opts) 944 (void)m_free(opts); 945 } 946 947 /* 948 * Verifies if redirect message is valid, according to RFC 1122 949 * 950 * @src: sockaddr with address of redirect originator 951 * @dst: sockaddr with destination in question 952 * @gateway: new proposed gateway 953 * 954 * Returns 0 on success. 955 */ 956 static int 957 icmp_verify_redirect_gateway(struct sockaddr_in *src, struct sockaddr_in *dst, 958 struct sockaddr_in *gateway, u_int fibnum) 959 { 960 struct nhop_object *nh; 961 struct ifaddr *ifa; 962 963 NET_EPOCH_ASSERT(); 964 965 /* Verify the gateway is directly reachable. */ 966 if ((ifa = ifa_ifwithnet((struct sockaddr *)gateway, 0, fibnum))==NULL) 967 return (ENETUNREACH); 968 969 /* TODO: fib-aware. */ 970 if (ifa_ifwithaddr_check((struct sockaddr *)gateway)) 971 return (EHOSTUNREACH); 972 973 nh = fib4_lookup(fibnum, dst->sin_addr, 0, NHR_NONE, 0); 974 if (nh == NULL) 975 return (EINVAL); 976 977 /* 978 * If the redirect isn't from our current router for this dst, 979 * it's either old or wrong. If it redirects us to ourselves, 980 * we have a routing loop, perhaps as a result of an interface 981 * going down recently. 982 */ 983 if (!sa_equal((struct sockaddr *)src, &nh->gw_sa)) 984 return (EINVAL); 985 if (nh->nh_ifa != ifa && ifa->ifa_addr->sa_family != AF_LINK) 986 return (EINVAL); 987 988 /* If host route already exists, ignore redirect. */ 989 if (nh->nh_flags & NHF_HOST) 990 return (EEXIST); 991 992 /* If the prefix is directly reachable, ignore redirect. */ 993 if (!(nh->nh_flags & NHF_GATEWAY)) 994 return (EEXIST); 995 996 return (0); 997 } 998 999 /* 1000 * Send an icmp packet back to the ip level, 1001 * after supplying a checksum. 1002 */ 1003 static void 1004 icmp_send(struct mbuf *m, struct mbuf *opts) 1005 { 1006 struct ip *ip = mtod(m, struct ip *); 1007 int hlen; 1008 struct icmp *icp; 1009 1010 hlen = ip->ip_hl << 2; 1011 m->m_data += hlen; 1012 m->m_len -= hlen; 1013 icp = mtod(m, struct icmp *); 1014 icp->icmp_cksum = 0; 1015 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 1016 m->m_data -= hlen; 1017 m->m_len += hlen; 1018 m->m_pkthdr.rcvif = (struct ifnet *)0; 1019 #ifdef ICMPPRINTFS 1020 if (icmpprintfs) { 1021 char dstbuf[INET_ADDRSTRLEN]; 1022 char srcbuf[INET_ADDRSTRLEN]; 1023 1024 printf("icmp_send dst %s src %s\n", 1025 inet_ntoa_r(ip->ip_dst, dstbuf), 1026 inet_ntoa_r(ip->ip_src, srcbuf)); 1027 } 1028 #endif 1029 (void) ip_output(m, opts, NULL, 0, NULL, NULL); 1030 } 1031 1032 /* 1033 * Return milliseconds since 00:00 UTC in network format. 1034 */ 1035 uint32_t 1036 iptime(void) 1037 { 1038 struct timeval atv; 1039 u_long t; 1040 1041 getmicrotime(&atv); 1042 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 1043 return (htonl(t)); 1044 } 1045 1046 /* 1047 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1048 * given current value MTU. If DIR is less than zero, a larger plateau 1049 * is returned; otherwise, a smaller value is returned. 1050 */ 1051 int 1052 ip_next_mtu(int mtu, int dir) 1053 { 1054 static int mtutab[] = { 1055 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1280, 1006, 508, 1056 296, 68, 0 1057 }; 1058 int i, size; 1059 1060 size = (sizeof mtutab) / (sizeof mtutab[0]); 1061 if (dir >= 0) { 1062 for (i = 0; i < size; i++) 1063 if (mtu > mtutab[i]) 1064 return mtutab[i]; 1065 } else { 1066 for (i = size - 1; i >= 0; i--) 1067 if (mtu < mtutab[i]) 1068 return mtutab[i]; 1069 if (mtu == mtutab[0]) 1070 return mtutab[0]; 1071 } 1072 return 0; 1073 } 1074 #endif /* INET */ 1075 1076 /* 1077 * badport_bandlim() - check for ICMP bandwidth limit 1078 * 1079 * Return 0 if it is ok to send an ICMP error response, -1 if we have 1080 * hit our bandwidth limit and it is not ok. 1081 * 1082 * If icmplim is <= 0, the feature is disabled and 0 is returned. 1083 * 1084 * For now we separate the TCP and UDP subsystems w/ different 'which' 1085 * values. We may eventually remove this separation (and simplify the 1086 * code further). 1087 * 1088 * Note that the printing of the error message is delayed so we can 1089 * properly print the icmp error rate that the system was trying to do 1090 * (i.e. 22000/100 pps, etc...). This can cause long delays in printing 1091 * the 'final' error, but it doesn't make sense to solve the printing 1092 * delay with more complex code. 1093 */ 1094 VNET_DEFINE_STATIC(struct counter_rate *, icmp_rates[BANDLIM_MAX]); 1095 #define V_icmp_rates VNET(icmp_rates) 1096 1097 static const char *icmp_rate_descrs[BANDLIM_MAX] = { 1098 [BANDLIM_ICMP_UNREACH] = "icmp unreach", 1099 [BANDLIM_ICMP_ECHO] = "icmp ping", 1100 [BANDLIM_ICMP_TSTAMP] = "icmp tstamp", 1101 [BANDLIM_TCP_RST] = "tcp reset", 1102 [BANDLIM_ICMP6_UNREACH] = "icmp6 unreach", 1103 [BANDLIM_SCTP_OOTB] = "sctp ootb", 1104 }; 1105 1106 static void 1107 icmplim_new_jitter(int which) 1108 { 1109 /* 1110 * Adjust limit +/- to jitter the measurement to deny a side-channel 1111 * port scan as in https://dl.acm.org/doi/10.1145/3372297.3417280 1112 */ 1113 KASSERT(which >= 0 && which < BANDLIM_MAX, 1114 ("%s: which %d", __func__, which)); 1115 if (V_icmplim_jitter > 0) 1116 V_icmplim_curr_jitter[which] = 1117 arc4random_uniform(V_icmplim_jitter * 2 + 1) - 1118 V_icmplim_jitter; 1119 } 1120 1121 static int 1122 sysctl_icmplim_and_jitter(SYSCTL_HANDLER_ARGS) 1123 { 1124 uint32_t new; 1125 int error; 1126 bool lim; 1127 1128 MPASS(oidp->oid_arg1 == &VNET_NAME(icmplim) || 1129 oidp->oid_arg1 == &VNET_NAME(icmplim_jitter)); 1130 1131 lim = (oidp->oid_arg1 == &VNET_NAME(icmplim)); 1132 new = lim ? V_icmplim : V_icmplim_jitter; 1133 error = sysctl_handle_int(oidp, &new, 0, req); 1134 if (error == 0 && req->newptr) { 1135 if (lim) { 1136 if (new != 0 && new <= V_icmplim_jitter) 1137 error = EINVAL; 1138 else 1139 V_icmplim = new; 1140 } else { 1141 if (new >= V_icmplim) 1142 error = EINVAL; 1143 else { 1144 V_icmplim_jitter = new; 1145 for (int i = 0; i < BANDLIM_MAX; i++) { 1146 icmplim_new_jitter(i); 1147 } 1148 } 1149 } 1150 } 1151 MPASS(V_icmplim == 0 || V_icmplim > V_icmplim_jitter); 1152 1153 return (error); 1154 } 1155 1156 static void 1157 icmp_bandlimit_init(void) 1158 { 1159 1160 for (int i = 0; i < BANDLIM_MAX; i++) { 1161 V_icmp_rates[i] = counter_rate_alloc(M_WAITOK, 1); 1162 icmplim_new_jitter(i); 1163 } 1164 } 1165 VNET_SYSINIT(icmp_bandlimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, 1166 icmp_bandlimit_init, NULL); 1167 1168 #ifdef VIMAGE 1169 static void 1170 icmp_bandlimit_uninit(void) 1171 { 1172 1173 for (int i = 0; i < BANDLIM_MAX; i++) 1174 counter_rate_free(V_icmp_rates[i]); 1175 } 1176 VNET_SYSUNINIT(icmp_bandlimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, 1177 icmp_bandlimit_uninit, NULL); 1178 #endif 1179 1180 int 1181 badport_bandlim(int which) 1182 { 1183 int64_t pps; 1184 1185 if (V_icmplim == 0) 1186 return (0); 1187 1188 KASSERT(which >= 0 && which < BANDLIM_MAX, 1189 ("%s: which %d", __func__, which)); 1190 1191 pps = counter_ratecheck(V_icmp_rates[which], V_icmplim + 1192 V_icmplim_curr_jitter[which]); 1193 if (pps > 0) { 1194 if (V_icmplim_output) 1195 log(LOG_NOTICE, 1196 "Limiting %s response from %jd to %d packets/sec\n", 1197 icmp_rate_descrs[which], (intmax_t )pps, 1198 V_icmplim + V_icmplim_curr_jitter[which]); 1199 icmplim_new_jitter(which); 1200 } 1201 if (pps == -1) 1202 return (-1); 1203 return (0); 1204 } 1205