1 /* 2 * Copyright (c) 1982, 1986, 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 30 * $FreeBSD: src/sys/netinet/ip_icmp.c,v 1.39.2.19 2003/01/24 05:11:34 sam Exp $ 31 */ 32 33 #include "opt_ipsec.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/socketops.h> 41 #include <sys/time.h> 42 #include <sys/kernel.h> 43 #include <sys/sysctl.h> 44 #include <sys/in_cksum.h> 45 46 #include <machine/stdarg.h> 47 48 #include <net/if.h> 49 #include <net/if_types.h> 50 #include <net/netisr2.h> 51 #include <net/netmsg2.h> 52 #include <net/route.h> 53 54 #define _IP_VHL 55 #include <netinet/in.h> 56 #include <netinet/in_systm.h> 57 #include <netinet/in_var.h> 58 #include <netinet/ip.h> 59 #include <netinet/ip_icmp.h> 60 #include <netinet/ip_var.h> 61 #include <netinet/icmp_var.h> 62 63 #ifdef IPSEC 64 #include <netinet6/ipsec.h> 65 #include <netproto/key/key.h> 66 #endif 67 68 #ifdef FAST_IPSEC 69 #include <netproto/ipsec/ipsec.h> 70 #include <netproto/ipsec/key.h> 71 #define IPSEC 72 #endif 73 74 /* 75 * ICMP routines: error generation, receive packet processing, and 76 * routines to turnaround packets back to the originator, and 77 * host table maintenance routines. 78 */ 79 80 struct icmpstat icmpstat; 81 SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats, CTLFLAG_RW, 82 &icmpstat, icmpstat, "ICMP statistics"); 83 84 static int icmpmaskrepl = 0; 85 SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW, 86 &icmpmaskrepl, 0, "Allow replies to netmask requests"); 87 88 static int drop_redirect = 0; 89 SYSCTL_INT(_net_inet_icmp, OID_AUTO, drop_redirect, CTLFLAG_RW, 90 &drop_redirect, 0, "Ignore ICMP redirects"); 91 92 static int log_redirect = 0; 93 SYSCTL_INT(_net_inet_icmp, OID_AUTO, log_redirect, CTLFLAG_RW, 94 &log_redirect, 0, "Enable output about ICMP redirects"); 95 96 static int discard_sourcequench = 1; 97 SYSCTL_INT(_net_inet_icmp, OID_AUTO, discard_sourcequench, CTLFLAG_RW, 98 &discard_sourcequench, 0, "Discard ICMP Source Quench"); 99 100 #ifdef ICMP_BANDLIM 101 102 /* 103 * ICMP error-response bandwidth limiting sysctl. If not enabled, sysctl 104 * variable content is -1 and read-only. 105 */ 106 107 static int icmplim = 200; 108 SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RW, 109 &icmplim, 0, "ICMP bandwidth limit"); 110 #else 111 112 static int icmplim = -1; 113 SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RD, 114 &icmplim, 0, "ICMP bandwidth limit"); 115 116 #endif 117 118 static int icmplim_output = 0; 119 SYSCTL_INT(_net_inet_icmp, OID_AUTO, icmplim_output, CTLFLAG_RW, 120 &icmplim_output, 0, "Enable output about ICMP bandwidth limits"); 121 122 /* 123 * ICMP broadcast echo sysctl 124 */ 125 126 static int icmpbmcastecho = 0; 127 SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_RW, 128 &icmpbmcastecho, 0, ""); 129 130 static char icmp_reply_src[IFNAMSIZ]; 131 SYSCTL_STRING(_net_inet_icmp, OID_AUTO, reply_src, CTLFLAG_RW, 132 icmp_reply_src, IFNAMSIZ, "icmp reply source for non-local packets."); 133 134 static int icmp_rfi; 135 SYSCTL_INT(_net_inet_icmp, OID_AUTO, reply_from_interface, CTLFLAG_RW, 136 &icmp_rfi, 0, "ICMP reply from incoming interface for " 137 "non-local packets"); 138 139 #ifdef ICMPPRINTFS 140 static int icmpprintfs = 0; 141 SYSCTL_INT(_net_inet_icmp, OID_AUTO, debug_prints, CTLFLAG_RW, 142 &icmpprintfs, 0, "extra ICMP debug prints"); 143 #endif 144 145 static void icmp_reflect (struct mbuf *); 146 static void icmp_send (struct mbuf *, struct mbuf *, struct route *); 147 148 extern struct protosw inetsw[]; 149 150 /* 151 * Generate an error packet of type error 152 * in response to bad packet ip. 153 */ 154 void 155 icmp_error(struct mbuf *n, int type, int code, n_long dest, int destmtu) 156 { 157 struct ip *oip = mtod(n, struct ip *), *nip; 158 unsigned oiplen = IP_VHL_HL(oip->ip_vhl) << 2; 159 struct icmp *icp; 160 struct mbuf *m; 161 unsigned icmplen; 162 163 #ifdef ICMPPRINTFS 164 if (icmpprintfs) 165 kprintf("icmp_error(%p, %d, %d)\n", oip, type, code); 166 #endif 167 if (type != ICMP_REDIRECT) 168 icmpstat.icps_error++; 169 /* 170 * Don't send error if the original packet was encrypted. 171 * Don't send error if not the first fragment of message. 172 * Don't error if the old packet protocol was ICMP 173 * error message, only known informational types. 174 */ 175 if (n->m_flags & M_DECRYPTED) 176 goto freeit; 177 if (oip->ip_off &~ (IP_MF|IP_DF)) 178 goto freeit; 179 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 180 n->m_len >= oiplen + ICMP_MINLEN && 181 !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) { 182 icmpstat.icps_oldicmp++; 183 goto freeit; 184 } 185 /* Don't send error in response to a multicast or broadcast packet */ 186 if (n->m_flags & (M_BCAST|M_MCAST)) 187 goto freeit; 188 /* 189 * First, formulate icmp message 190 */ 191 m = m_gethdr(M_NOWAIT, MT_HEADER); 192 if (m == NULL) 193 goto freeit; 194 icmplen = min(oiplen + 8, oip->ip_len); 195 if (icmplen < sizeof(struct ip)) 196 panic("icmp_error: bad length"); 197 m->m_len = icmplen + ICMP_MINLEN; 198 MH_ALIGN(m, m->m_len); 199 icp = mtod(m, struct icmp *); 200 if ((u_int)type > ICMP_MAXTYPE) 201 panic("icmp_error"); 202 icmpstat.icps_outhist[type]++; 203 icp->icmp_type = type; 204 if (type == ICMP_REDIRECT) 205 icp->icmp_gwaddr.s_addr = dest; 206 else { 207 icp->icmp_void = 0; 208 /* 209 * The following assignments assume an overlay with the 210 * zeroed icmp_void field. 211 */ 212 if (type == ICMP_PARAMPROB) { 213 icp->icmp_pptr = code; 214 code = 0; 215 } else if (type == ICMP_UNREACH && 216 code == ICMP_UNREACH_NEEDFRAG && destmtu) { 217 icp->icmp_nextmtu = htons(destmtu); 218 } 219 } 220 221 icp->icmp_code = code; 222 m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip); 223 nip = &icp->icmp_ip; 224 225 /* 226 * Convert fields to network representation. 227 */ 228 nip->ip_len = htons(nip->ip_len); 229 nip->ip_off = htons(nip->ip_off); 230 231 /* 232 * Now, copy old ip header (without options) 233 * in front of icmp message. 234 */ 235 if (m->m_data - sizeof(struct ip) < m->m_pktdat) 236 panic("icmp len"); 237 m->m_data -= sizeof(struct ip); 238 m->m_len += sizeof(struct ip); 239 m->m_pkthdr.len = m->m_len; 240 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif; 241 nip = mtod(m, struct ip *); 242 bcopy(oip, nip, sizeof(struct ip)); 243 nip->ip_len = m->m_len; 244 nip->ip_vhl = IP_VHL_BORING; 245 nip->ip_p = IPPROTO_ICMP; 246 nip->ip_tos = 0; 247 m->m_pkthdr.fw_flags |= n->m_pkthdr.fw_flags & FW_MBUF_GENERATED; 248 icmp_reflect(m); 249 250 freeit: 251 m_freem(n); 252 } 253 254 static void 255 icmp_ctlinput_done_handler(netmsg_t nmsg) 256 { 257 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg; 258 struct mbuf *m = msg->m; 259 int hlen = msg->hlen; 260 261 rip_input(&m, &hlen, msg->proto); 262 } 263 264 static void 265 icmp_ctlinput_done(struct mbuf *m) 266 { 267 struct netmsg_ctlinput *msg = &m->m_hdr.mh_ctlmsg; 268 269 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0, 270 icmp_ctlinput_done_handler); 271 lwkt_sendmsg(netisr_cpuport(0), &msg->base.lmsg); 272 } 273 274 static void 275 icmp_mtudisc(struct mbuf *m, int hlen) 276 { 277 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET }; 278 struct rtentry *rt; 279 struct icmp *icp; 280 281 KASSERT(curthread->td_type == TD_TYPE_NETISR, ("not in netisr")); 282 283 icp = mtodoff(m, struct icmp *, hlen); 284 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 285 286 /* 287 * MTU discovery: 288 * If we got a needfrag and there is a host route to the original 289 * destination, and the MTU is not locked, then set the MTU in the 290 * route to the suggested new value (if given) and then notify as 291 * usual. The ULPs will notice that the MTU has changed and adapt 292 * accordingly. If no new MTU was suggested, then we guess a new 293 * one less than the current value. If the new MTU is unreasonably 294 * small (arbitrarily set at 296), then we reset the MTU to the 295 * interface value and enable the lock bit, indicating that we are 296 * no longer doing MTU discovery. 297 */ 298 rt = rtpurelookup((struct sockaddr *)&icmpsrc); 299 if (rt != NULL && (rt->rt_flags & RTF_HOST) && 300 !(rt->rt_rmx.rmx_locks & RTV_MTU)) { 301 #ifdef DEBUG_MTUDISC 302 char src_buf[INET_ADDRSTRLEN]; 303 #endif 304 int mtu; 305 306 mtu = ntohs(icp->icmp_nextmtu); 307 if (!mtu) 308 mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu, 1); 309 #ifdef DEBUG_MTUDISC 310 kprintf("MTU for %s reduced to %d\n", 311 inet_ntop(AF_INET, &icmpsrc.sin_addr, 312 src_buf, INET_ADDRSTRLEN), mtu); 313 #endif 314 if (mtu < 296) { 315 /* rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; */ 316 rt->rt_rmx.rmx_locks |= RTV_MTU; 317 } else if (rt->rt_rmx.rmx_mtu > mtu) { 318 rt->rt_rmx.rmx_mtu = mtu; 319 } 320 } 321 if (rt != NULL) 322 --rt->rt_refcnt; 323 324 /* 325 * XXX if the packet contains [IPv4 AH TCP], we can't make a 326 * notification to TCP layer. 327 */ 328 so_pr_ctlinput_direct(&inetsw[ip_protox[icp->icmp_ip.ip_p]], 329 PRC_MSGSIZE, (struct sockaddr *)&icmpsrc, &icp->icmp_ip); 330 } 331 332 static void 333 icmp_mtudisc_handler(netmsg_t nmsg) 334 { 335 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg; 336 int nextcpu; 337 338 ASSERT_NETISR_NCPUS(mycpuid); 339 340 icmp_mtudisc(msg->m, msg->hlen); 341 342 nextcpu = mycpuid + 1; 343 if (nextcpu < netisr_ncpus) 344 lwkt_forwardmsg(netisr_cpuport(nextcpu), &msg->base.lmsg); 345 else 346 icmp_ctlinput_done(msg->m); 347 } 348 349 static boolean_t 350 icmp_mtudisc_start(struct mbuf *m, int hlen, int proto) 351 { 352 struct netmsg_ctlinput *msg; 353 354 ASSERT_NETISR0; 355 356 icmp_mtudisc(m, hlen); 357 358 if (netisr_ncpus == 1) { 359 /* There is only one netisr; done */ 360 return FALSE; 361 } 362 363 msg = &m->m_hdr.mh_ctlmsg; 364 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0, 365 icmp_mtudisc_handler); 366 msg->m = m; 367 msg->cmd = PRC_MSGSIZE; 368 msg->hlen = hlen; 369 msg->proto = proto; 370 371 lwkt_sendmsg(netisr_cpuport(1), &msg->base.lmsg); 372 return TRUE; 373 } 374 375 static void 376 icmp_ctlinput(struct mbuf *m, int cmd, int hlen) 377 { 378 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET }; 379 struct icmp *icp; 380 381 KASSERT(curthread->td_type == TD_TYPE_NETISR, ("not in netisr")); 382 383 icp = mtodoff(m, struct icmp *, hlen); 384 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 385 386 /* 387 * XXX if the packet contains [IPv4 AH TCP], we can't make a 388 * notification to TCP layer. 389 */ 390 so_pr_ctlinput_direct(&inetsw[ip_protox[icp->icmp_ip.ip_p]], 391 cmd, (struct sockaddr *)&icmpsrc, &icp->icmp_ip); 392 } 393 394 static void 395 icmp_ctlinput_handler(netmsg_t nmsg) 396 { 397 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg; 398 399 ASSERT_NETISR_NCPUS(mycpuid); 400 401 icmp_ctlinput(msg->m, msg->cmd, msg->hlen); 402 icmp_ctlinput_done(msg->m); 403 } 404 405 static void 406 icmp_ctlinput_start(struct mbuf *m, struct lwkt_port *port, 407 int cmd, int hlen, int proto) 408 { 409 struct netmsg_ctlinput *msg; 410 411 KASSERT(&curthread->td_msgport != port, 412 ("send icmp ctlinput to the current netisr")); 413 414 msg = &m->m_hdr.mh_ctlmsg; 415 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0, 416 icmp_ctlinput_handler); 417 msg->m = m; 418 msg->cmd = cmd; 419 msg->hlen = hlen; 420 msg->proto = proto; 421 422 lwkt_sendmsg(port, &msg->base.lmsg); 423 } 424 425 static void 426 icmp_ctlinput_global_handler(netmsg_t nmsg) 427 { 428 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg; 429 int nextcpu; 430 431 ASSERT_NETISR_NCPUS(mycpuid); 432 433 icmp_ctlinput(msg->m, msg->cmd, msg->hlen); 434 435 nextcpu = mycpuid + 1; 436 if (nextcpu < netisr_ncpus) 437 lwkt_forwardmsg(netisr_cpuport(nextcpu), &msg->base.lmsg); 438 else 439 icmp_ctlinput_done(msg->m); 440 } 441 442 static void 443 icmp_ctlinput_global_start(struct mbuf *m, int cmd, int hlen, int proto) 444 { 445 struct netmsg_ctlinput *msg; 446 447 ASSERT_NETISR0; 448 KASSERT(netisr_ncpus > 1, ("there is only 1 netisr cpu")); 449 450 icmp_ctlinput(m, cmd, hlen); 451 452 msg = &m->m_hdr.mh_ctlmsg; 453 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0, 454 icmp_ctlinput_global_handler); 455 msg->m = m; 456 msg->cmd = cmd; 457 msg->hlen = hlen; 458 msg->proto = proto; 459 460 lwkt_sendmsg(netisr_cpuport(1), &msg->base.lmsg); 461 } 462 463 #define ICMP_RTREDIRECT_FLAGS (RTF_GATEWAY | RTF_HOST) 464 465 static void 466 icmp_redirect(struct mbuf *m, int hlen, boolean_t prt) 467 { 468 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET }; 469 struct sockaddr_in icmpdst = { sizeof(struct sockaddr_in), AF_INET }; 470 struct sockaddr_in icmpgw = { sizeof(struct sockaddr_in), AF_INET }; 471 struct icmp *icp; 472 struct ip *ip; 473 474 KASSERT(curthread->td_type == TD_TYPE_NETISR, ("not in netisr")); 475 476 ip = mtod(m, struct ip *); 477 icp = mtodoff(m, struct icmp *, hlen); 478 479 /* 480 * Short circuit routing redirects to force immediate change 481 * in the kernel's routing tables. The message is also handed 482 * to anyone listening on a raw socket (e.g. the routing daemon 483 * for use in updating its tables). 484 */ 485 #ifdef ICMPPRINTFS 486 if (icmpprintfs && prt) { 487 char dst_buf[INET_ADDRSTRLEN], gw_buf[INET_ADDRSTRLEN]; 488 489 kprintf("redirect dst %s to %s\n", 490 inet_ntop(AF_INET, &icp->icmp_ip.ip_dst, 491 dst_buf, INET_ADDRSTRLEN), 492 inet_ntop(AF_INET, &icp->icmp_gwaddr, 493 gw_buf, INET_ADDRSTRLEN)); 494 } 495 #endif 496 icmpgw.sin_addr = ip->ip_src; 497 icmpdst.sin_addr = icp->icmp_gwaddr; 498 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 499 rtredirect_oncpu((struct sockaddr *)&icmpsrc, 500 (struct sockaddr *)&icmpdst, NULL, ICMP_RTREDIRECT_FLAGS, 501 (struct sockaddr *)&icmpgw); 502 kpfctlinput_direct(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc); 503 } 504 505 static void 506 icmp_redirect_done_handler(netmsg_t nmsg) 507 { 508 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg; 509 struct mbuf *m = msg->m; 510 int hlen = msg->hlen; 511 #ifdef IPSEC 512 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET }; 513 struct icmp *icp = mtodoff(m, struct icmp *, hlen);; 514 515 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 516 key_sa_routechange((struct sockaddr *)&icmpsrc); 517 #endif 518 rip_input(&m, &hlen, msg->proto); 519 } 520 521 static void 522 icmp_redirect_done(struct mbuf *m, int hlen, boolean_t dispatch_rip) 523 { 524 struct rt_addrinfo rtinfo; 525 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET }; 526 struct sockaddr_in icmpdst = { sizeof(struct sockaddr_in), AF_INET }; 527 struct sockaddr_in icmpgw = { sizeof(struct sockaddr_in), AF_INET }; 528 struct icmp *icp; 529 struct ip *ip; 530 531 ip = mtod(m, struct ip *); 532 icp = mtodoff(m, struct icmp *, hlen); 533 534 icmpgw.sin_addr = ip->ip_src; 535 icmpdst.sin_addr = icp->icmp_gwaddr; 536 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 537 538 bzero(&rtinfo, sizeof(struct rt_addrinfo)); 539 rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&icmpsrc; 540 rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&icmpdst; 541 rtinfo.rti_info[RTAX_NETMASK] = NULL; 542 rtinfo.rti_info[RTAX_AUTHOR] = (struct sockaddr *)&icmpgw; 543 rt_missmsg(RTM_REDIRECT, &rtinfo, ICMP_RTREDIRECT_FLAGS, 0); 544 545 if (dispatch_rip) { 546 struct netmsg_ctlinput *msg = &m->m_hdr.mh_ctlmsg; 547 548 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0, 549 icmp_redirect_done_handler); 550 lwkt_sendmsg(netisr_cpuport(0), &msg->base.lmsg); 551 } 552 } 553 554 static void 555 icmp_redirect_handler(netmsg_t nmsg) 556 { 557 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg; 558 int nextcpu; 559 560 ASSERT_NETISR_NCPUS(mycpuid); 561 562 icmp_redirect(msg->m, msg->hlen, FALSE); 563 564 nextcpu = mycpuid + 1; 565 if (nextcpu < netisr_ncpus) 566 lwkt_forwardmsg(netisr_cpuport(nextcpu), &msg->base.lmsg); 567 else 568 icmp_redirect_done(msg->m, msg->hlen, TRUE); 569 } 570 571 static boolean_t 572 icmp_redirect_start(struct mbuf *m, int hlen, int proto) 573 { 574 struct netmsg_ctlinput *msg; 575 576 ASSERT_NETISR0; 577 578 icmp_redirect(m, hlen, TRUE); 579 580 if (netisr_ncpus == 1) { 581 /* There is only one netisr; done */ 582 icmp_redirect_done(m, hlen, FALSE); 583 return FALSE; 584 } 585 586 msg = &m->m_hdr.mh_ctlmsg; 587 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0, 588 icmp_redirect_handler); 589 msg->m = m; 590 msg->cmd = PRC_REDIRECT_HOST; 591 msg->hlen = hlen; 592 msg->proto = proto; 593 594 lwkt_sendmsg(netisr_cpuport(1), &msg->base.lmsg); 595 return TRUE; 596 } 597 598 /* 599 * Process a received ICMP message. 600 */ 601 int 602 icmp_input(struct mbuf **mp, int *offp, int proto) 603 { 604 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET }; 605 struct sockaddr_in icmpdst = { sizeof(struct sockaddr_in), AF_INET }; 606 struct icmp *icp; 607 struct in_ifaddr *ia; 608 struct mbuf *m = *mp; 609 struct ip *ip = mtod(m, struct ip *); 610 int icmplen = ip->ip_len; 611 int i, hlen; 612 int code; 613 614 ASSERT_NETISR0; 615 616 *mp = NULL; 617 hlen = *offp; 618 619 /* 620 * Locate icmp structure in mbuf, and check 621 * that not corrupted and of at least minimum length. 622 */ 623 #ifdef ICMPPRINTFS 624 if (icmpprintfs) { 625 char src_buf[INET_ADDRSTRLEN], dst_buf[INET_ADDRSTRLEN]; 626 627 kprintf("icmp_input from %s to %s, len %d\n", 628 inet_ntop(AF_INET, &ip->ip_src, src_buf, INET_ADDRSTRLEN), 629 inet_ntop(AF_INET, &ip->ip_dst, dst_buf, INET_ADDRSTRLEN), 630 icmplen); 631 } 632 #endif 633 if (icmplen < ICMP_MINLEN) { 634 icmpstat.icps_tooshort++; 635 goto freeit; 636 } 637 i = hlen + min(icmplen, ICMP_ADVLENMIN); 638 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) { 639 icmpstat.icps_tooshort++; 640 return(IPPROTO_DONE); 641 } 642 ip = mtod(m, struct ip *); 643 644 if (in_cksum_skip(m, hlen + icmplen, hlen)) { 645 icmpstat.icps_checksum++; 646 goto freeit; 647 } 648 icp = (struct icmp *)((caddr_t)ip + hlen); 649 650 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) { 651 /* 652 * Deliver very specific ICMP type only. 653 */ 654 switch (icp->icmp_type) { 655 case ICMP_UNREACH: 656 case ICMP_TIMXCEED: 657 break; 658 default: 659 goto freeit; 660 } 661 } 662 663 #ifdef ICMPPRINTFS 664 if (icmpprintfs) 665 kprintf("icmp_input, type %d code %d\n", icp->icmp_type, 666 icp->icmp_code); 667 #endif 668 669 /* 670 * Message type specific processing. 671 */ 672 if (icp->icmp_type > ICMP_MAXTYPE) 673 goto raw; 674 icmpstat.icps_inhist[icp->icmp_type]++; 675 code = icp->icmp_code; 676 switch (icp->icmp_type) { 677 678 case ICMP_UNREACH: 679 switch (code) { 680 case ICMP_UNREACH_NET: 681 case ICMP_UNREACH_HOST: 682 case ICMP_UNREACH_SRCFAIL: 683 case ICMP_UNREACH_NET_UNKNOWN: 684 case ICMP_UNREACH_HOST_UNKNOWN: 685 case ICMP_UNREACH_ISOLATED: 686 case ICMP_UNREACH_TOSNET: 687 case ICMP_UNREACH_TOSHOST: 688 case ICMP_UNREACH_HOST_PRECEDENCE: 689 case ICMP_UNREACH_PRECEDENCE_CUTOFF: 690 code = PRC_UNREACH_NET; 691 break; 692 693 case ICMP_UNREACH_NEEDFRAG: 694 code = PRC_MSGSIZE; 695 break; 696 697 /* 698 * RFC 1122, Sections 3.2.2.1 and 4.2.3.9. 699 * Treat subcodes 2,3 as immediate RST 700 */ 701 case ICMP_UNREACH_PROTOCOL: 702 case ICMP_UNREACH_PORT: 703 code = PRC_UNREACH_PORT; 704 break; 705 706 case ICMP_UNREACH_NET_PROHIB: 707 case ICMP_UNREACH_HOST_PROHIB: 708 case ICMP_UNREACH_FILTER_PROHIB: 709 code = PRC_UNREACH_ADMIN_PROHIB; 710 break; 711 712 default: 713 goto badcode; 714 } 715 goto deliver; 716 717 case ICMP_TIMXCEED: 718 if (code > 1) 719 goto badcode; 720 code += PRC_TIMXCEED_INTRANS; 721 goto deliver; 722 723 case ICMP_PARAMPROB: 724 if (code > 1) 725 goto badcode; 726 code = PRC_PARAMPROB; 727 goto deliver; 728 729 case ICMP_SOURCEQUENCH: 730 if (code) 731 goto badcode; 732 if (discard_sourcequench) 733 break; 734 code = PRC_QUENCH; 735 deliver: 736 /* 737 * Problem with datagram; advise higher level routines. 738 */ 739 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 740 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) { 741 icmpstat.icps_badlen++; 742 goto freeit; 743 } 744 /* Discard ICMP's in response to multicast packets */ 745 if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr))) 746 goto badcode; 747 #ifdef ICMPPRINTFS 748 if (icmpprintfs) 749 kprintf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 750 #endif 751 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 752 753 /* 754 * MTU discovery 755 */ 756 if (code == PRC_MSGSIZE) { 757 /* Run MTU discovery in all netisrs */ 758 if (icmp_mtudisc_start(m, hlen, proto)) { 759 /* Forwarded; done */ 760 return IPPROTO_DONE; 761 } 762 /* Move on; run rip_input() directly */ 763 } else { 764 struct protosw *pr; 765 struct lwkt_port *port; 766 int cpu; 767 768 pr = &inetsw[ip_protox[icp->icmp_ip.ip_p]]; 769 port = so_pr_ctlport(pr, code, 770 (struct sockaddr *)&icmpsrc, &icp->icmp_ip, &cpu); 771 if (port != NULL) { 772 if (cpu == netisr_ncpus) { 773 if (netisr_ncpus > 1) { 774 /* 775 * Run pr_ctlinput in all 776 * netisrs 777 */ 778 icmp_ctlinput_global_start(m, 779 code, hlen, proto); 780 return IPPROTO_DONE; 781 } 782 /* 783 * There is only one netisr; run 784 * pr_ctlinput directly. 785 */ 786 } else if (cpu != mycpuid) { 787 /* 788 * Send to the target netisr to run 789 * pr_ctlinput. 790 */ 791 icmp_ctlinput_start(m, port, 792 code, hlen, proto); 793 return IPPROTO_DONE; 794 } 795 796 /* 797 * The target netisr is this netisr. 798 * 799 * XXX if the packet contains [IPv4 AH TCP], 800 * we can't make a notification to TCP layer. 801 */ 802 so_pr_ctlinput_direct(pr, code, 803 (struct sockaddr *)&icmpsrc, &icp->icmp_ip); 804 } 805 /* Move on; run rip_input() directly */ 806 } 807 break; 808 badcode: 809 icmpstat.icps_badcode++; 810 break; 811 812 case ICMP_ECHO: 813 if (!icmpbmcastecho 814 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 815 icmpstat.icps_bmcastecho++; 816 break; 817 } 818 icp->icmp_type = ICMP_ECHOREPLY; 819 #ifdef ICMP_BANDLIM 820 if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0) 821 goto freeit; 822 else 823 #endif 824 goto reflect; 825 826 case ICMP_TSTAMP: 827 if (!icmpbmcastecho 828 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 829 icmpstat.icps_bmcasttstamp++; 830 break; 831 } 832 if (icmplen < ICMP_TSLEN) { 833 icmpstat.icps_badlen++; 834 break; 835 } 836 icp->icmp_type = ICMP_TSTAMPREPLY; 837 icp->icmp_rtime = iptime(); 838 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 839 #ifdef ICMP_BANDLIM 840 if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0) 841 goto freeit; 842 else 843 #endif 844 goto reflect; 845 846 case ICMP_MASKREQ: 847 if (icmpmaskrepl == 0) 848 break; 849 /* 850 * We are not able to respond with all ones broadcast 851 * unless we receive it over a point-to-point interface. 852 */ 853 if (icmplen < ICMP_MASKLEN) 854 break; 855 switch (ip->ip_dst.s_addr) { 856 857 case INADDR_BROADCAST: 858 case INADDR_ANY: 859 icmpdst.sin_addr = ip->ip_src; 860 break; 861 862 default: 863 icmpdst.sin_addr = ip->ip_dst; 864 } 865 ia = (struct in_ifaddr *)ifaof_ifpforaddr( 866 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif); 867 if (ia == NULL) 868 break; 869 if (ia->ia_ifp == 0) 870 break; 871 icp->icmp_type = ICMP_MASKREPLY; 872 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 873 if (ip->ip_src.s_addr == 0) { 874 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 875 ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr; 876 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 877 ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr; 878 } 879 reflect: 880 ip->ip_len += hlen; /* since ip_input deducts this */ 881 icmpstat.icps_reflect++; 882 icmpstat.icps_outhist[icp->icmp_type]++; 883 icmp_reflect(m); 884 return(IPPROTO_DONE); 885 886 case ICMP_REDIRECT: 887 if (log_redirect) { 888 char src_buf[INET_ADDRSTRLEN]; 889 char dst_buf[INET_ADDRSTRLEN]; 890 char gwy_buf[INET_ADDRSTRLEN]; 891 892 kprintf("icmp redirect from %s: %s => %s\n", 893 inet_ntop(AF_INET, &ip->ip_src, 894 src_buf, INET_ADDRSTRLEN), 895 inet_ntop(AF_INET, &icp->icmp_ip.ip_dst, 896 dst_buf, INET_ADDRSTRLEN), 897 inet_ntop(AF_INET, &icp->icmp_gwaddr, 898 gwy_buf, INET_ADDRSTRLEN)); 899 } 900 if (drop_redirect) 901 break; 902 if (code > 3) 903 goto badcode; 904 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 905 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) { 906 icmpstat.icps_badlen++; 907 break; 908 } 909 #ifdef ICMPPRINTFS 910 if (icmpprintfs) { 911 char dst_buf[INET_ADDRSTRLEN], gw_buf[INET_ADDRSTRLEN]; 912 913 kprintf("redirect dst %s to %s\n", 914 inet_ntop(AF_INET, &icp->icmp_ip.ip_dst, 915 dst_buf, INET_ADDRSTRLEN), 916 inet_ntop(AF_INET, &icp->icmp_gwaddr, 917 gw_buf, INET_ADDRSTRLEN)); 918 } 919 #endif 920 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 921 922 /* Run redirect in all netisrs */ 923 if (icmp_redirect_start(m, hlen, proto)) { 924 /* Forwarded; done */ 925 return IPPROTO_DONE; 926 } 927 /* Move on; run rip_input() directly */ 928 #ifdef IPSEC 929 key_sa_routechange((struct sockaddr *)&icmpsrc); 930 #endif 931 break; 932 933 /* 934 * No kernel processing for the following; 935 * just fall through to send to raw listener. 936 */ 937 case ICMP_ECHOREPLY: 938 case ICMP_ROUTERADVERT: 939 case ICMP_ROUTERSOLICIT: 940 case ICMP_TSTAMPREPLY: 941 case ICMP_IREQREPLY: 942 case ICMP_MASKREPLY: 943 default: 944 break; 945 } 946 947 raw: 948 *mp = m; 949 rip_input(mp, offp, proto); 950 return(IPPROTO_DONE); 951 952 freeit: 953 m_freem(m); 954 return(IPPROTO_DONE); 955 } 956 957 /* 958 * Reflect the ip packet back to the source 959 */ 960 static void 961 icmp_reflect(struct mbuf *m) 962 { 963 struct ip *ip = mtod(m, struct ip *); 964 struct in_ifaddr *ia; 965 struct in_ifaddr_container *iac; 966 struct ifaddr_container *ifac; 967 struct ifnet *ifp; 968 struct in_addr t; 969 struct mbuf *opts = NULL; 970 int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 971 struct route *ro = NULL, rt; 972 973 if (!in_canforward(ip->ip_src) && 974 ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) != 975 (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { 976 m_freem(m); /* Bad return address */ 977 icmpstat.icps_badaddr++; 978 goto done; /* Ip_output() will check for broadcast */ 979 } 980 t = ip->ip_dst; 981 ip->ip_dst = ip->ip_src; 982 983 ro = &rt; 984 bzero(ro, sizeof *ro); 985 986 /* 987 * If the incoming packet was addressed directly to us, 988 * use dst as the src for the reply. Otherwise (broadcast 989 * or anonymous), use the address which corresponds 990 * to the incoming interface. 991 */ 992 ia = NULL; 993 LIST_FOREACH(iac, INADDR_HASH(t.s_addr), ia_hash) { 994 if (t.s_addr == IA_SIN(iac->ia)->sin_addr.s_addr) { 995 ia = iac->ia; 996 goto match; 997 } 998 } 999 ifp = m->m_pkthdr.rcvif; 1000 if (ifp != NULL && (ifp->if_flags & IFF_BROADCAST)) { 1001 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) { 1002 struct ifaddr *ifa = ifac->ifa; 1003 1004 if (ifa->ifa_addr->sa_family != AF_INET) 1005 continue; 1006 ia = ifatoia(ifa); 1007 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == 1008 t.s_addr) 1009 goto match; 1010 } 1011 } 1012 /* 1013 * If the packet was transiting through us, use the address of 1014 * the interface the packet came through in. If that interface 1015 * doesn't have a suitable IP address, the normal selection 1016 * criteria apply. 1017 */ 1018 if (icmp_rfi && ifp != NULL) { 1019 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) { 1020 struct ifaddr *ifa = ifac->ifa; 1021 1022 if (ifa->ifa_addr->sa_family != AF_INET) 1023 continue; 1024 ia = ifatoia(ifa); 1025 goto match; 1026 } 1027 } 1028 /* 1029 * If the incoming packet was not addressed directly to us, use 1030 * designated interface for icmp replies specified by sysctl 1031 * net.inet.icmp.reply_src (default not set). Otherwise continue 1032 * with normal source selection. 1033 */ 1034 if (icmp_reply_src[0] != '\0' && 1035 (ifp = ifunit_netisr(icmp_reply_src))) { 1036 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) { 1037 struct ifaddr *ifa = ifac->ifa; 1038 1039 if (ifa->ifa_addr->sa_family != AF_INET) 1040 continue; 1041 ia = ifatoia(ifa); 1042 goto match; 1043 } 1044 } 1045 /* 1046 * If the packet was transiting through us, use the address of 1047 * the interface that is the closest to the packet source. 1048 * When we don't have a route back to the packet source, stop here 1049 * and drop the packet. 1050 */ 1051 ia = ip_rtaddr(ip->ip_dst, ro); 1052 if (ia == NULL) { 1053 m_freem(m); 1054 icmpstat.icps_noroute++; 1055 goto done; 1056 } 1057 match: 1058 t = IA_SIN(ia)->sin_addr; 1059 ip->ip_src = t; 1060 ip->ip_ttl = ip_defttl; 1061 1062 if (optlen > 0) { 1063 u_char *cp; 1064 int opt, cnt; 1065 u_int len; 1066 1067 /* 1068 * Retrieve any source routing from the incoming packet; 1069 * add on any record-route or timestamp options. 1070 */ 1071 cp = (u_char *) (ip + 1); 1072 if ((opts = ip_srcroute(m)) == NULL && 1073 (opts = m_gethdr(M_NOWAIT, MT_HEADER))) { 1074 opts->m_len = sizeof(struct in_addr); 1075 mtod(opts, struct in_addr *)->s_addr = 0; 1076 } 1077 if (opts) { 1078 #ifdef ICMPPRINTFS 1079 if (icmpprintfs) 1080 kprintf("icmp_reflect optlen %d rt %d => ", 1081 optlen, opts->m_len); 1082 #endif 1083 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 1084 opt = cp[IPOPT_OPTVAL]; 1085 if (opt == IPOPT_EOL) 1086 break; 1087 if (opt == IPOPT_NOP) 1088 len = 1; 1089 else { 1090 if (cnt < IPOPT_OLEN + sizeof *cp) 1091 break; 1092 len = cp[IPOPT_OLEN]; 1093 if (len < IPOPT_OLEN + sizeof *cp || 1094 len > cnt) 1095 break; 1096 } 1097 /* 1098 * Should check for overflow, but it 1099 * "can't happen". 1100 */ 1101 if (opt == IPOPT_RR || opt == IPOPT_TS || 1102 opt == IPOPT_SECURITY) { 1103 bcopy(cp, 1104 mtod(opts, caddr_t) + opts->m_len, 1105 len); 1106 opts->m_len += len; 1107 } 1108 } 1109 /* Terminate & pad, if necessary */ 1110 cnt = opts->m_len % 4; 1111 if (cnt) { 1112 for (; cnt < 4; cnt++) { 1113 *(mtod(opts, caddr_t) + opts->m_len) = 1114 IPOPT_EOL; 1115 opts->m_len++; 1116 } 1117 } 1118 #ifdef ICMPPRINTFS 1119 if (icmpprintfs) 1120 kprintf("%d\n", opts->m_len); 1121 #endif 1122 } 1123 /* 1124 * Now strip out original options by copying rest of first 1125 * mbuf's data back, and adjust the IP length. 1126 */ 1127 ip->ip_len -= optlen; 1128 ip->ip_vhl = IP_VHL_BORING; 1129 m->m_len -= optlen; 1130 if (m->m_flags & M_PKTHDR) 1131 m->m_pkthdr.len -= optlen; 1132 optlen += sizeof(struct ip); 1133 bcopy((caddr_t)ip + optlen, ip + 1, 1134 m->m_len - sizeof(struct ip)); 1135 } 1136 m->m_pkthdr.fw_flags &= FW_MBUF_GENERATED; 1137 m->m_flags &= ~(M_BCAST|M_MCAST); 1138 icmp_send(m, opts, ro); 1139 done: 1140 if (opts) 1141 m_free(opts); 1142 if (ro && ro->ro_rt) 1143 RTFREE(ro->ro_rt); 1144 } 1145 1146 /* 1147 * Send an icmp packet back to the ip level, 1148 * after supplying a checksum. 1149 */ 1150 static void 1151 icmp_send(struct mbuf *m, struct mbuf *opts, struct route *rt) 1152 { 1153 struct ip *ip = mtod(m, struct ip *); 1154 struct icmp *icp; 1155 int hlen; 1156 1157 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 1158 m->m_data += hlen; 1159 m->m_len -= hlen; 1160 icp = mtod(m, struct icmp *); 1161 icp->icmp_cksum = 0; 1162 icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen); 1163 m->m_data -= hlen; 1164 m->m_len += hlen; 1165 m->m_pkthdr.rcvif = NULL; 1166 #ifdef ICMPPRINTFS 1167 if (icmpprintfs) { 1168 char dst_buf[INET_ADDRSTRLEN], src_buf[INET_ADDRSTRLEN]; 1169 1170 kprintf("icmp_send dst %s src %s\n", 1171 inet_ntop(AF_INET, &ip->ip_dst, dst_buf, INET_ADDRSTRLEN), 1172 inet_ntop(AF_INET, &ip->ip_src, src_buf, INET_ADDRSTRLEN)); 1173 } 1174 #endif 1175 ip_output(m, opts, rt, 0, NULL, NULL); 1176 } 1177 1178 n_time 1179 iptime(void) 1180 { 1181 struct timeval atv; 1182 u_long t; 1183 1184 getmicrotime(&atv); 1185 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 1186 return (htonl(t)); 1187 } 1188 1189 #if 1 1190 /* 1191 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1192 * given current value MTU. If DIR is less than zero, a larger plateau 1193 * is returned; otherwise, a smaller value is returned. 1194 */ 1195 int 1196 ip_next_mtu(int mtu, int dir) 1197 { 1198 static int mtutab[] = { 1199 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296, 1200 68, 0 1201 }; 1202 int i; 1203 1204 for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) { 1205 if (mtu >= mtutab[i]) 1206 break; 1207 } 1208 1209 if (dir < 0) { 1210 if (i == 0) { 1211 return 0; 1212 } else { 1213 return mtutab[i - 1]; 1214 } 1215 } else { 1216 if (mtutab[i] == 0) { 1217 return 0; 1218 } else if(mtu > mtutab[i]) { 1219 return mtutab[i]; 1220 } else { 1221 return mtutab[i + 1]; 1222 } 1223 } 1224 } 1225 #endif 1226 1227 #ifdef ICMP_BANDLIM 1228 /* 1229 * badport_bandlim() - check for ICMP bandwidth limit 1230 * 1231 * Return 0 if it is ok to send an ICMP error response, -1 if we have 1232 * hit our bandwidth limit and it is not ok. 1233 * 1234 * If icmplim is <= 0, the feature is disabled and 0 is returned. 1235 * 1236 * For now we separate the TCP and UDP subsystems w/ different 'which' 1237 * values. We may eventually remove this separation (and simplify the 1238 * code further). 1239 * 1240 * Note that the printing of the error message is delayed so we can 1241 * properly print the icmp error rate that the system was trying to do 1242 * (i.e. 22000/100 pps, etc...). This can cause long delays in printing 1243 * the 'final' error, but it doesn't make sense to solve the printing 1244 * delay with more complex code. 1245 */ 1246 int 1247 badport_bandlim(int which) 1248 { 1249 static int lticks[BANDLIM_MAX + 1]; 1250 static int lpackets[BANDLIM_MAX + 1]; 1251 int dticks; 1252 const char *bandlimittype[] = { 1253 "Limiting icmp unreach response", 1254 "Limiting icmp ping response", 1255 "Limiting icmp tstamp response", 1256 "Limiting closed port RST response", 1257 "Limiting open port RST response" 1258 }; 1259 1260 /* 1261 * Return ok status if feature disabled or argument out of 1262 * ranage. 1263 */ 1264 1265 if (icmplim <= 0 || which > BANDLIM_MAX || which < 0) 1266 return(0); 1267 dticks = ticks - lticks[which]; 1268 1269 /* 1270 * reset stats when cumulative dt exceeds one second. 1271 */ 1272 1273 if ((unsigned int)dticks > hz) { 1274 if (lpackets[which] > icmplim && icmplim_output) { 1275 kprintf("%s from %d to %d packets per second\n", 1276 bandlimittype[which], 1277 lpackets[which], 1278 icmplim 1279 ); 1280 } 1281 lticks[which] = ticks; 1282 lpackets[which] = 0; 1283 } 1284 1285 /* 1286 * bump packet count 1287 */ 1288 1289 if (++lpackets[which] > icmplim) { 1290 return(-1); 1291 } 1292 return(0); 1293 } 1294 #endif 1295