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