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 int fibnum; 467 468 NET_EPOCH_ASSERT(); 469 470 *mp = NULL; 471 472 /* 473 * Locate icmp structure in mbuf, and check 474 * that not corrupted and of at least minimum length. 475 */ 476 #ifdef ICMPPRINTFS 477 if (icmpprintfs) { 478 char srcbuf[INET_ADDRSTRLEN]; 479 char dstbuf[INET_ADDRSTRLEN]; 480 481 printf("icmp_input from %s to %s, len %d\n", 482 inet_ntoa_r(ip->ip_src, srcbuf), 483 inet_ntoa_r(ip->ip_dst, dstbuf), icmplen); 484 } 485 #endif 486 if (icmplen < ICMP_MINLEN) { 487 ICMPSTAT_INC(icps_tooshort); 488 goto freeit; 489 } 490 i = hlen + min(icmplen, ICMP_ADVLENMIN); 491 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) { 492 ICMPSTAT_INC(icps_tooshort); 493 return (IPPROTO_DONE); 494 } 495 ip = mtod(m, struct ip *); 496 m->m_len -= hlen; 497 m->m_data += hlen; 498 icp = mtod(m, struct icmp *); 499 if (in_cksum(m, icmplen)) { 500 ICMPSTAT_INC(icps_checksum); 501 goto freeit; 502 } 503 m->m_len += hlen; 504 m->m_data -= hlen; 505 506 #ifdef ICMPPRINTFS 507 if (icmpprintfs) 508 printf("icmp_input, type %d code %d\n", icp->icmp_type, 509 icp->icmp_code); 510 #endif 511 512 /* 513 * Message type specific processing. 514 */ 515 if (icp->icmp_type > ICMP_MAXTYPE) 516 goto raw; 517 518 /* Initialize */ 519 bzero(&icmpsrc, sizeof(icmpsrc)); 520 icmpsrc.sin_len = sizeof(struct sockaddr_in); 521 icmpsrc.sin_family = AF_INET; 522 bzero(&icmpdst, sizeof(icmpdst)); 523 icmpdst.sin_len = sizeof(struct sockaddr_in); 524 icmpdst.sin_family = AF_INET; 525 bzero(&icmpgw, sizeof(icmpgw)); 526 icmpgw.sin_len = sizeof(struct sockaddr_in); 527 icmpgw.sin_family = AF_INET; 528 529 ICMPSTAT_INC2(icps_inhist, icp->icmp_type); 530 code = icp->icmp_code; 531 switch (icp->icmp_type) { 532 case ICMP_UNREACH: 533 if (code > ICMP_UNREACH_PRECEDENCE_CUTOFF) 534 goto badcode; 535 else 536 goto deliver; 537 538 case ICMP_TIMXCEED: 539 if (code > ICMP_TIMXCEED_REASS) 540 goto badcode; 541 else 542 goto deliver; 543 544 case ICMP_PARAMPROB: 545 if (code > ICMP_PARAMPROB_LENGTH) 546 goto badcode; 547 548 deliver: 549 /* 550 * Problem with datagram; advise higher level routines. 551 */ 552 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 553 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 554 ICMPSTAT_INC(icps_badlen); 555 goto freeit; 556 } 557 /* Discard ICMP's in response to multicast packets */ 558 if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr))) 559 goto badcode; 560 /* Filter out responses to INADDR_ANY, protocols ignore it. */ 561 if (icp->icmp_ip.ip_dst.s_addr == INADDR_ANY || 562 icp->icmp_ip.ip_src.s_addr == INADDR_ANY) 563 goto freeit; 564 #ifdef ICMPPRINTFS 565 if (icmpprintfs) 566 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 567 #endif 568 /* 569 * XXX if the packet contains [IPv4 AH TCP], we can't make a 570 * notification to TCP layer. 571 */ 572 i = sizeof(struct ip) + min(icmplen, ICMP_ADVLENPREF(icp)); 573 ip_stripoptions(m); 574 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) { 575 /* This should actually not happen */ 576 ICMPSTAT_INC(icps_tooshort); 577 return (IPPROTO_DONE); 578 } 579 ip = mtod(m, struct ip *); 580 icp = (struct icmp *)(ip + 1); 581 /* 582 * The upper layer handler can rely on: 583 * - The outer IP header has no options. 584 * - The outer IP header, the ICMP header, the inner IP header, 585 * and the first n bytes of the inner payload are contiguous. 586 * n is at least 8, but might be larger based on 587 * ICMP_ADVLENPREF. See its definition in ip_icmp.h. 588 */ 589 if (ip_ctlprotox[icp->icmp_ip.ip_p] != NULL) 590 ip_ctlprotox[icp->icmp_ip.ip_p](icp); 591 break; 592 593 badcode: 594 ICMPSTAT_INC(icps_badcode); 595 break; 596 597 case ICMP_ECHO: 598 if (!V_icmpbmcastecho 599 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 600 ICMPSTAT_INC(icps_bmcastecho); 601 break; 602 } 603 if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0) 604 goto freeit; 605 icp->icmp_type = ICMP_ECHOREPLY; 606 goto reflect; 607 608 case ICMP_TSTAMP: 609 if (V_icmptstamprepl == 0) 610 break; 611 if (!V_icmpbmcastecho 612 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 613 ICMPSTAT_INC(icps_bmcasttstamp); 614 break; 615 } 616 if (icmplen < ICMP_TSLEN) { 617 ICMPSTAT_INC(icps_badlen); 618 break; 619 } 620 if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0) 621 goto freeit; 622 icp->icmp_type = ICMP_TSTAMPREPLY; 623 icp->icmp_rtime = iptime(); 624 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 625 goto reflect; 626 627 case ICMP_MASKREQ: 628 if (V_icmpmaskrepl == 0) 629 break; 630 /* 631 * We are not able to respond with all ones broadcast 632 * unless we receive it over a point-to-point interface. 633 */ 634 if (icmplen < ICMP_MASKLEN) 635 break; 636 if (in_broadcast(ip->ip_dst)) 637 icmpdst.sin_addr = ip->ip_src; 638 else 639 icmpdst.sin_addr = ip->ip_dst; 640 ia = (struct in_ifaddr *)ifaof_ifpforaddr( 641 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif); 642 if (ia == NULL) 643 break; 644 if (ia->ia_ifp == NULL) 645 break; 646 icp->icmp_type = ICMP_MASKREPLY; 647 if (V_icmpmaskfake == 0) 648 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 649 else 650 icp->icmp_mask = V_icmpmaskfake; 651 if (ip->ip_src.s_addr == 0) { 652 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 653 ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr; 654 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 655 ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr; 656 } 657 reflect: 658 ICMPSTAT_INC(icps_reflect); 659 ICMPSTAT_INC2(icps_outhist, icp->icmp_type); 660 icmp_reflect(m); 661 return (IPPROTO_DONE); 662 663 case ICMP_REDIRECT: 664 if (V_log_redirect) { 665 u_long src, dst, gw; 666 667 src = ntohl(ip->ip_src.s_addr); 668 dst = ntohl(icp->icmp_ip.ip_dst.s_addr); 669 gw = ntohl(icp->icmp_gwaddr.s_addr); 670 printf("icmp redirect from %d.%d.%d.%d: " 671 "%d.%d.%d.%d => %d.%d.%d.%d\n", 672 (int)(src >> 24), (int)((src >> 16) & 0xff), 673 (int)((src >> 8) & 0xff), (int)(src & 0xff), 674 (int)(dst >> 24), (int)((dst >> 16) & 0xff), 675 (int)((dst >> 8) & 0xff), (int)(dst & 0xff), 676 (int)(gw >> 24), (int)((gw >> 16) & 0xff), 677 (int)((gw >> 8) & 0xff), (int)(gw & 0xff)); 678 } 679 /* 680 * RFC1812 says we must ignore ICMP redirects if we 681 * are acting as router. 682 */ 683 if (V_drop_redirect || V_ipforwarding) 684 break; 685 if (code > 3) 686 goto badcode; 687 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 688 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 689 ICMPSTAT_INC(icps_badlen); 690 break; 691 } 692 /* 693 * Short circuit routing redirects to force 694 * immediate change in the kernel's routing 695 * tables. The message is also handed to anyone 696 * listening on a raw socket (e.g. the routing 697 * daemon for use in updating its tables). 698 */ 699 icmpgw.sin_addr = ip->ip_src; 700 icmpdst.sin_addr = icp->icmp_gwaddr; 701 #ifdef ICMPPRINTFS 702 if (icmpprintfs) { 703 char dstbuf[INET_ADDRSTRLEN]; 704 char gwbuf[INET_ADDRSTRLEN]; 705 706 printf("redirect dst %s to %s\n", 707 inet_ntoa_r(icp->icmp_ip.ip_dst, dstbuf), 708 inet_ntoa_r(icp->icmp_gwaddr, gwbuf)); 709 } 710 #endif 711 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 712 713 /* 714 * RFC 1122 says network (code 0,2) redirects SHOULD 715 * be treated identically to the host redirects. 716 * Given that, ignore network masks. 717 */ 718 719 /* 720 * Variable values: 721 * icmpsrc: route destination 722 * icmpdst: route gateway 723 * icmpgw: message source 724 */ 725 726 if (icmp_verify_redirect_gateway(&icmpgw, &icmpsrc, &icmpdst, 727 M_GETFIB(m)) != 0) { 728 /* TODO: increment bad redirects here */ 729 break; 730 } 731 732 for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) { 733 rib_add_redirect(fibnum, (struct sockaddr *)&icmpsrc, 734 (struct sockaddr *)&icmpdst, 735 (struct sockaddr *)&icmpgw, m->m_pkthdr.rcvif, 736 RTF_GATEWAY, V_redirtimeout); 737 } 738 break; 739 740 /* 741 * No kernel processing for the following; 742 * just fall through to send to raw listener. 743 */ 744 case ICMP_ECHOREPLY: 745 case ICMP_ROUTERADVERT: 746 case ICMP_ROUTERSOLICIT: 747 case ICMP_TSTAMPREPLY: 748 case ICMP_IREQREPLY: 749 case ICMP_MASKREPLY: 750 case ICMP_SOURCEQUENCH: 751 default: 752 break; 753 } 754 755 raw: 756 *mp = m; 757 rip_input(mp, offp, proto); 758 return (IPPROTO_DONE); 759 760 freeit: 761 m_freem(m); 762 return (IPPROTO_DONE); 763 } 764 765 /* 766 * Reflect the ip packet back to the source 767 */ 768 static void 769 icmp_reflect(struct mbuf *m) 770 { 771 struct ip *ip = mtod(m, struct ip *); 772 struct ifaddr *ifa; 773 struct ifnet *ifp; 774 struct in_ifaddr *ia; 775 struct in_addr t; 776 struct nhop_object *nh; 777 struct mbuf *opts = NULL; 778 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 779 780 NET_EPOCH_ASSERT(); 781 782 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)) || 783 (IN_EXPERIMENTAL(ntohl(ip->ip_src.s_addr)) && !V_ip_allow_net240) || 784 (IN_ZERONET(ntohl(ip->ip_src.s_addr)) && !V_ip_allow_net0) || 785 in_nullhost(ip->ip_src) ) { 786 m_freem(m); /* Bad return address */ 787 ICMPSTAT_INC(icps_badaddr); 788 goto done; /* ip_output() will check for broadcast */ 789 } 790 791 t = ip->ip_dst; 792 ip->ip_dst = ip->ip_src; 793 794 /* 795 * Source selection for ICMP replies: 796 * 797 * If the incoming packet was addressed directly to one of our 798 * own addresses, use dst as the src for the reply. 799 */ 800 CK_LIST_FOREACH(ia, INADDR_HASH(t.s_addr), ia_hash) { 801 if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr) { 802 t = IA_SIN(ia)->sin_addr; 803 goto match; 804 } 805 } 806 807 /* 808 * If the incoming packet was addressed to one of our broadcast 809 * addresses, use the first non-broadcast address which corresponds 810 * to the incoming interface. 811 */ 812 ifp = m->m_pkthdr.rcvif; 813 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) { 814 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 815 if (ifa->ifa_addr->sa_family != AF_INET) 816 continue; 817 ia = ifatoia(ifa); 818 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == 819 t.s_addr) { 820 t = IA_SIN(ia)->sin_addr; 821 goto match; 822 } 823 } 824 } 825 /* 826 * If the packet was transiting through us, use the address of 827 * the interface the packet came through in. If that interface 828 * doesn't have a suitable IP address, the normal selection 829 * criteria apply. 830 */ 831 if (V_icmp_rfi && ifp != NULL) { 832 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 833 if (ifa->ifa_addr->sa_family != AF_INET) 834 continue; 835 ia = ifatoia(ifa); 836 t = IA_SIN(ia)->sin_addr; 837 goto match; 838 } 839 } 840 /* 841 * If the incoming packet was not addressed directly to us, use 842 * designated interface for icmp replies specified by sysctl 843 * net.inet.icmp.reply_src (default not set). Otherwise continue 844 * with normal source selection. 845 */ 846 if (V_reply_src[0] != '\0' && (ifp = ifunit(V_reply_src))) { 847 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 848 if (ifa->ifa_addr->sa_family != AF_INET) 849 continue; 850 ia = ifatoia(ifa); 851 t = IA_SIN(ia)->sin_addr; 852 goto match; 853 } 854 } 855 /* 856 * If the packet was transiting through us, use the address of 857 * the interface that is the closest to the packet source. 858 * When we don't have a route back to the packet source, stop here 859 * and drop the packet. 860 */ 861 nh = fib4_lookup(M_GETFIB(m), ip->ip_dst, 0, NHR_NONE, 0); 862 if (nh == NULL) { 863 m_freem(m); 864 ICMPSTAT_INC(icps_noroute); 865 goto done; 866 } 867 t = IA_SIN(ifatoia(nh->nh_ifa))->sin_addr; 868 match: 869 #ifdef MAC 870 mac_netinet_icmp_replyinplace(m); 871 #endif 872 ip->ip_src = t; 873 /* ip->ip_tos will be reflected. */ 874 ip->ip_off = htons(0); 875 ip->ip_ttl = V_ip_defttl; 876 877 if (optlen > 0) { 878 u_char *cp; 879 int opt, cnt; 880 u_int len; 881 882 /* 883 * Retrieve any source routing from the incoming packet; 884 * add on any record-route or timestamp options. 885 */ 886 cp = (u_char *) (ip + 1); 887 if ((opts = ip_srcroute(m)) == NULL && 888 (opts = m_gethdr(M_NOWAIT, MT_DATA))) { 889 opts->m_len = sizeof(struct in_addr); 890 mtod(opts, struct in_addr *)->s_addr = 0; 891 } 892 if (opts) { 893 #ifdef ICMPPRINTFS 894 if (icmpprintfs) 895 printf("icmp_reflect optlen %d rt %d => ", 896 optlen, opts->m_len); 897 #endif 898 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 899 opt = cp[IPOPT_OPTVAL]; 900 if (opt == IPOPT_EOL) 901 break; 902 if (opt == IPOPT_NOP) 903 len = 1; 904 else { 905 if (cnt < IPOPT_OLEN + sizeof(*cp)) 906 break; 907 len = cp[IPOPT_OLEN]; 908 if (len < IPOPT_OLEN + sizeof(*cp) || 909 len > cnt) 910 break; 911 } 912 /* 913 * Should check for overflow, but it "can't happen" 914 */ 915 if (opt == IPOPT_RR || opt == IPOPT_TS || 916 opt == IPOPT_SECURITY) { 917 bcopy((caddr_t)cp, 918 mtod(opts, caddr_t) + opts->m_len, len); 919 opts->m_len += len; 920 } 921 } 922 /* Terminate & pad, if necessary */ 923 cnt = opts->m_len % 4; 924 if (cnt) { 925 for (; cnt < 4; cnt++) { 926 *(mtod(opts, caddr_t) + opts->m_len) = 927 IPOPT_EOL; 928 opts->m_len++; 929 } 930 } 931 #ifdef ICMPPRINTFS 932 if (icmpprintfs) 933 printf("%d\n", opts->m_len); 934 #endif 935 } 936 ip_stripoptions(m); 937 } 938 m_tag_delete_nonpersistent(m); 939 m->m_flags &= ~(M_BCAST|M_MCAST); 940 icmp_send(m, opts); 941 done: 942 if (opts) 943 (void)m_free(opts); 944 } 945 946 /* 947 * Verifies if redirect message is valid, according to RFC 1122 948 * 949 * @src: sockaddr with address of redirect originator 950 * @dst: sockaddr with destination in question 951 * @gateway: new proposed gateway 952 * 953 * Returns 0 on success. 954 */ 955 static int 956 icmp_verify_redirect_gateway(struct sockaddr_in *src, struct sockaddr_in *dst, 957 struct sockaddr_in *gateway, u_int fibnum) 958 { 959 struct nhop_object *nh; 960 struct ifaddr *ifa; 961 962 NET_EPOCH_ASSERT(); 963 964 /* Verify the gateway is directly reachable. */ 965 if ((ifa = ifa_ifwithnet((struct sockaddr *)gateway, 0, fibnum))==NULL) 966 return (ENETUNREACH); 967 968 /* TODO: fib-aware. */ 969 if (ifa_ifwithaddr_check((struct sockaddr *)gateway)) 970 return (EHOSTUNREACH); 971 972 nh = fib4_lookup(fibnum, dst->sin_addr, 0, NHR_NONE, 0); 973 if (nh == NULL) 974 return (EINVAL); 975 976 /* 977 * If the redirect isn't from our current router for this dst, 978 * it's either old or wrong. If it redirects us to ourselves, 979 * we have a routing loop, perhaps as a result of an interface 980 * going down recently. 981 */ 982 if (!sa_equal((struct sockaddr *)src, &nh->gw_sa)) 983 return (EINVAL); 984 if (nh->nh_ifa != ifa && ifa->ifa_addr->sa_family != AF_LINK) 985 return (EINVAL); 986 987 /* If host route already exists, ignore redirect. */ 988 if (nh->nh_flags & NHF_HOST) 989 return (EEXIST); 990 991 /* If the prefix is directly reachable, ignore redirect. */ 992 if (!(nh->nh_flags & NHF_GATEWAY)) 993 return (EEXIST); 994 995 return (0); 996 } 997 998 /* 999 * Send an icmp packet back to the ip level, 1000 * after supplying a checksum. 1001 */ 1002 static void 1003 icmp_send(struct mbuf *m, struct mbuf *opts) 1004 { 1005 struct ip *ip = mtod(m, struct ip *); 1006 int hlen; 1007 struct icmp *icp; 1008 1009 hlen = ip->ip_hl << 2; 1010 m->m_data += hlen; 1011 m->m_len -= hlen; 1012 icp = mtod(m, struct icmp *); 1013 icp->icmp_cksum = 0; 1014 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 1015 m->m_data -= hlen; 1016 m->m_len += hlen; 1017 m->m_pkthdr.rcvif = (struct ifnet *)0; 1018 #ifdef ICMPPRINTFS 1019 if (icmpprintfs) { 1020 char dstbuf[INET_ADDRSTRLEN]; 1021 char srcbuf[INET_ADDRSTRLEN]; 1022 1023 printf("icmp_send dst %s src %s\n", 1024 inet_ntoa_r(ip->ip_dst, dstbuf), 1025 inet_ntoa_r(ip->ip_src, srcbuf)); 1026 } 1027 #endif 1028 (void) ip_output(m, opts, NULL, 0, NULL, NULL); 1029 } 1030 1031 /* 1032 * Return milliseconds since 00:00 UTC in network format. 1033 */ 1034 uint32_t 1035 iptime(void) 1036 { 1037 struct timeval atv; 1038 u_long t; 1039 1040 getmicrotime(&atv); 1041 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 1042 return (htonl(t)); 1043 } 1044 1045 /* 1046 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1047 * given current value MTU. If DIR is less than zero, a larger plateau 1048 * is returned; otherwise, a smaller value is returned. 1049 */ 1050 int 1051 ip_next_mtu(int mtu, int dir) 1052 { 1053 static int mtutab[] = { 1054 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1280, 1006, 508, 1055 296, 68, 0 1056 }; 1057 int i, size; 1058 1059 size = (sizeof mtutab) / (sizeof mtutab[0]); 1060 if (dir >= 0) { 1061 for (i = 0; i < size; i++) 1062 if (mtu > mtutab[i]) 1063 return mtutab[i]; 1064 } else { 1065 for (i = size - 1; i >= 0; i--) 1066 if (mtu < mtutab[i]) 1067 return mtutab[i]; 1068 if (mtu == mtutab[0]) 1069 return mtutab[0]; 1070 } 1071 return 0; 1072 } 1073 #endif /* INET */ 1074 1075 /* 1076 * badport_bandlim() - check for ICMP bandwidth limit 1077 * 1078 * Return 0 if it is ok to send an ICMP error response, -1 if we have 1079 * hit our bandwidth limit and it is not ok. 1080 * 1081 * If icmplim is <= 0, the feature is disabled and 0 is returned. 1082 * 1083 * For now we separate the TCP and UDP subsystems w/ different 'which' 1084 * values. We may eventually remove this separation (and simplify the 1085 * code further). 1086 * 1087 * Note that the printing of the error message is delayed so we can 1088 * properly print the icmp error rate that the system was trying to do 1089 * (i.e. 22000/100 pps, etc...). This can cause long delays in printing 1090 * the 'final' error, but it doesn't make sense to solve the printing 1091 * delay with more complex code. 1092 */ 1093 VNET_DEFINE_STATIC(struct counter_rate *, icmp_rates[BANDLIM_MAX]); 1094 #define V_icmp_rates VNET(icmp_rates) 1095 1096 static const char *icmp_rate_descrs[BANDLIM_MAX] = { 1097 [BANDLIM_ICMP_UNREACH] = "icmp unreach", 1098 [BANDLIM_ICMP_ECHO] = "icmp ping", 1099 [BANDLIM_ICMP_TSTAMP] = "icmp tstamp", 1100 [BANDLIM_TCP_RST] = "tcp reset", 1101 [BANDLIM_ICMP6_UNREACH] = "icmp6 unreach", 1102 [BANDLIM_SCTP_OOTB] = "sctp ootb", 1103 }; 1104 1105 static void 1106 icmplim_new_jitter(int which) 1107 { 1108 /* 1109 * Adjust limit +/- to jitter the measurement to deny a side-channel 1110 * port scan as in https://dl.acm.org/doi/10.1145/3372297.3417280 1111 */ 1112 KASSERT(which >= 0 && which < BANDLIM_MAX, 1113 ("%s: which %d", __func__, which)); 1114 if (V_icmplim_jitter > 0) 1115 V_icmplim_curr_jitter[which] = 1116 arc4random_uniform(V_icmplim_jitter * 2 + 1) - 1117 V_icmplim_jitter; 1118 } 1119 1120 static int 1121 sysctl_icmplim_and_jitter(SYSCTL_HANDLER_ARGS) 1122 { 1123 uint32_t new; 1124 int error; 1125 bool lim; 1126 1127 MPASS(oidp->oid_arg1 == &VNET_NAME(icmplim) || 1128 oidp->oid_arg1 == &VNET_NAME(icmplim_jitter)); 1129 1130 lim = (oidp->oid_arg1 == &VNET_NAME(icmplim)); 1131 new = lim ? V_icmplim : V_icmplim_jitter; 1132 error = sysctl_handle_int(oidp, &new, 0, req); 1133 if (error == 0 && req->newptr) { 1134 if (lim) { 1135 if (new != 0 && new <= V_icmplim_jitter) 1136 error = EINVAL; 1137 else 1138 V_icmplim = new; 1139 } else { 1140 if (new >= V_icmplim) 1141 error = EINVAL; 1142 else { 1143 V_icmplim_jitter = new; 1144 for (int i = 0; i < BANDLIM_MAX; i++) { 1145 icmplim_new_jitter(i); 1146 } 1147 } 1148 } 1149 } 1150 MPASS(V_icmplim == 0 || V_icmplim > V_icmplim_jitter); 1151 1152 return (error); 1153 } 1154 1155 static void 1156 icmp_bandlimit_init(void) 1157 { 1158 1159 for (int i = 0; i < BANDLIM_MAX; i++) { 1160 V_icmp_rates[i] = counter_rate_alloc(M_WAITOK, 1); 1161 icmplim_new_jitter(i); 1162 } 1163 } 1164 VNET_SYSINIT(icmp_bandlimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, 1165 icmp_bandlimit_init, NULL); 1166 1167 #ifdef VIMAGE 1168 static void 1169 icmp_bandlimit_uninit(void) 1170 { 1171 1172 for (int i = 0; i < BANDLIM_MAX; i++) 1173 counter_rate_free(V_icmp_rates[i]); 1174 } 1175 VNET_SYSUNINIT(icmp_bandlimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, 1176 icmp_bandlimit_uninit, NULL); 1177 #endif 1178 1179 int 1180 badport_bandlim(int which) 1181 { 1182 int64_t pps; 1183 1184 if (V_icmplim == 0) 1185 return (0); 1186 1187 KASSERT(which >= 0 && which < BANDLIM_MAX, 1188 ("%s: which %d", __func__, which)); 1189 1190 pps = counter_ratecheck(V_icmp_rates[which], V_icmplim + 1191 V_icmplim_curr_jitter[which]); 1192 if (pps > 0) { 1193 if (V_icmplim_output) 1194 log(LOG_NOTICE, 1195 "Limiting %s response from %jd to %d packets/sec\n", 1196 icmp_rate_descrs[which], (intmax_t )pps, 1197 V_icmplim + V_icmplim_curr_jitter[which]); 1198 icmplim_new_jitter(which); 1199 } 1200 if (pps == -1) 1201 return (-1); 1202 return (0); 1203 } 1204