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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 34 * $Id: ip_icmp.c,v 1.21 1996/07/24 18:46:17 wollman Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/malloc.h> 40 #include <sys/mbuf.h> 41 #include <sys/protosw.h> 42 #include <sys/socket.h> 43 #include <sys/time.h> 44 #include <sys/kernel.h> 45 #include <sys/socket.h> 46 #include <sys/sysctl.h> 47 48 #include <net/if.h> 49 #include <net/route.h> 50 51 #define _IP_VHL 52 #include <netinet/in.h> 53 #include <netinet/in_systm.h> 54 #include <netinet/in_var.h> 55 #include <netinet/ip.h> 56 #include <netinet/ip_icmp.h> 57 #include <netinet/ip_var.h> 58 #include <netinet/icmp_var.h> 59 60 /* 61 * ICMP routines: error generation, receive packet processing, and 62 * routines to turnaround packets back to the originator, and 63 * host table maintenance routines. 64 */ 65 66 static struct icmpstat icmpstat; 67 SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats, CTLFLAG_RD, 68 &icmpstat, icmpstat, ""); 69 70 static int icmpmaskrepl = 0; 71 SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW, 72 &icmpmaskrepl, 0, ""); 73 74 #ifdef ICMPPRINTFS 75 int icmpprintfs = 0; 76 #endif 77 78 static void icmp_reflect __P((struct mbuf *)); 79 static void icmp_send __P((struct mbuf *, struct mbuf *)); 80 static int ip_next_mtu __P((int, int)); 81 82 extern struct protosw inetsw[]; 83 84 /* 85 * Generate an error packet of type error 86 * in response to bad packet ip. 87 */ 88 void 89 icmp_error(n, type, code, dest, destifp) 90 struct mbuf *n; 91 int type, code; 92 n_long dest; 93 struct ifnet *destifp; 94 { 95 register struct ip *oip = mtod(n, struct ip *), *nip; 96 register unsigned oiplen = IP_VHL_HL(oip->ip_vhl) << 2; 97 register struct icmp *icp; 98 register struct mbuf *m; 99 unsigned icmplen; 100 101 #ifdef ICMPPRINTFS 102 if (icmpprintfs) 103 printf("icmp_error(%p, %x, %d)\n", oip, type, code); 104 #endif 105 if (type != ICMP_REDIRECT) 106 icmpstat.icps_error++; 107 /* 108 * Don't send error if not the first fragment of message. 109 * Don't error if the old packet protocol was ICMP 110 * error message, only known informational types. 111 */ 112 if (oip->ip_off &~ (IP_MF|IP_DF)) 113 goto freeit; 114 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 115 n->m_len >= oiplen + ICMP_MINLEN && 116 !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) { 117 icmpstat.icps_oldicmp++; 118 goto freeit; 119 } 120 /* Don't send error in response to a multicast or broadcast packet */ 121 if (n->m_flags & (M_BCAST|M_MCAST)) 122 goto freeit; 123 /* 124 * First, formulate icmp message 125 */ 126 m = m_gethdr(M_DONTWAIT, MT_HEADER); 127 if (m == NULL) 128 goto freeit; 129 icmplen = oiplen + min(8, oip->ip_len); 130 m->m_len = icmplen + ICMP_MINLEN; 131 MH_ALIGN(m, m->m_len); 132 icp = mtod(m, struct icmp *); 133 if ((u_int)type > ICMP_MAXTYPE) 134 panic("icmp_error"); 135 icmpstat.icps_outhist[type]++; 136 icp->icmp_type = type; 137 if (type == ICMP_REDIRECT) 138 icp->icmp_gwaddr.s_addr = dest; 139 else { 140 icp->icmp_void = 0; 141 /* 142 * The following assignments assume an overlay with the 143 * zeroed icmp_void field. 144 */ 145 if (type == ICMP_PARAMPROB) { 146 icp->icmp_pptr = code; 147 code = 0; 148 } else if (type == ICMP_UNREACH && 149 code == ICMP_UNREACH_NEEDFRAG && destifp) { 150 icp->icmp_nextmtu = htons(destifp->if_mtu); 151 } 152 } 153 154 icp->icmp_code = code; 155 bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, icmplen); 156 nip = &icp->icmp_ip; 157 nip->ip_len = htons((u_short)(nip->ip_len + oiplen)); 158 159 /* 160 * Now, copy old ip header (without options) 161 * in front of icmp message. 162 */ 163 if (m->m_data - sizeof(struct ip) < m->m_pktdat) 164 panic("icmp len"); 165 m->m_data -= sizeof(struct ip); 166 m->m_len += sizeof(struct ip); 167 m->m_pkthdr.len = m->m_len; 168 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif; 169 nip = mtod(m, struct ip *); 170 bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip)); 171 nip->ip_len = m->m_len; 172 nip->ip_vhl = IP_VHL_BORING; 173 nip->ip_p = IPPROTO_ICMP; 174 nip->ip_tos = 0; 175 icmp_reflect(m); 176 177 freeit: 178 m_freem(n); 179 } 180 181 static struct sockaddr_in icmpsrc = { sizeof (struct sockaddr_in), AF_INET }; 182 static struct sockaddr_in icmpdst = { sizeof (struct sockaddr_in), AF_INET }; 183 static struct sockaddr_in icmpgw = { sizeof (struct sockaddr_in), AF_INET }; 184 185 /* 186 * Process a received ICMP message. 187 */ 188 void 189 icmp_input(m, hlen) 190 register struct mbuf *m; 191 int hlen; 192 { 193 register struct icmp *icp; 194 register struct ip *ip = mtod(m, struct ip *); 195 int icmplen = ip->ip_len; 196 register int i; 197 struct in_ifaddr *ia; 198 void (*ctlfunc) __P((int, struct sockaddr *, void *)); 199 int code; 200 201 /* 202 * Locate icmp structure in mbuf, and check 203 * that not corrupted and of at least minimum length. 204 */ 205 #ifdef ICMPPRINTFS 206 if (icmpprintfs) { 207 char buf[4 * sizeof "123"]; 208 strcpy(buf, inet_ntoa(ip->ip_src)); 209 printf("icmp_input from %s to %s, len %d\n", 210 buf, inet_ntoa(ip->ip_dst), icmplen); 211 } 212 #endif 213 if (icmplen < ICMP_MINLEN) { 214 icmpstat.icps_tooshort++; 215 goto freeit; 216 } 217 i = hlen + min(icmplen, ICMP_ADVLENMIN); 218 if (m->m_len < i && (m = m_pullup(m, i)) == 0) { 219 icmpstat.icps_tooshort++; 220 return; 221 } 222 ip = mtod(m, struct ip *); 223 m->m_len -= hlen; 224 m->m_data += hlen; 225 icp = mtod(m, struct icmp *); 226 if (in_cksum(m, icmplen)) { 227 icmpstat.icps_checksum++; 228 goto freeit; 229 } 230 m->m_len += hlen; 231 m->m_data -= hlen; 232 233 #ifdef ICMPPRINTFS 234 if (icmpprintfs) 235 printf("icmp_input, type %d code %d\n", icp->icmp_type, 236 icp->icmp_code); 237 #endif 238 239 /* 240 * Message type specific processing. 241 */ 242 if (icp->icmp_type > ICMP_MAXTYPE) 243 goto raw; 244 icmpstat.icps_inhist[icp->icmp_type]++; 245 code = icp->icmp_code; 246 switch (icp->icmp_type) { 247 248 case ICMP_UNREACH: 249 switch (code) { 250 case ICMP_UNREACH_NET: 251 case ICMP_UNREACH_HOST: 252 case ICMP_UNREACH_PROTOCOL: 253 case ICMP_UNREACH_PORT: 254 case ICMP_UNREACH_SRCFAIL: 255 code += PRC_UNREACH_NET; 256 break; 257 258 case ICMP_UNREACH_NEEDFRAG: 259 code = PRC_MSGSIZE; 260 break; 261 262 case ICMP_UNREACH_NET_UNKNOWN: 263 case ICMP_UNREACH_NET_PROHIB: 264 case ICMP_UNREACH_TOSNET: 265 code = PRC_UNREACH_NET; 266 break; 267 268 case ICMP_UNREACH_HOST_UNKNOWN: 269 case ICMP_UNREACH_ISOLATED: 270 case ICMP_UNREACH_HOST_PROHIB: 271 case ICMP_UNREACH_TOSHOST: 272 code = PRC_UNREACH_HOST; 273 break; 274 275 case ICMP_UNREACH_FILTER_PROHIB: 276 case ICMP_UNREACH_HOST_PRECEDENCE: 277 case ICMP_UNREACH_PRECEDENCE_CUTOFF: 278 code = PRC_UNREACH_PORT; 279 break; 280 281 default: 282 goto badcode; 283 } 284 goto deliver; 285 286 case ICMP_TIMXCEED: 287 if (code > 1) 288 goto badcode; 289 code += PRC_TIMXCEED_INTRANS; 290 goto deliver; 291 292 case ICMP_PARAMPROB: 293 if (code > 1) 294 goto badcode; 295 code = PRC_PARAMPROB; 296 goto deliver; 297 298 case ICMP_SOURCEQUENCH: 299 if (code) 300 goto badcode; 301 code = PRC_QUENCH; 302 deliver: 303 /* 304 * Problem with datagram; advise higher level routines. 305 */ 306 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 307 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) { 308 icmpstat.icps_badlen++; 309 goto freeit; 310 } 311 NTOHS(icp->icmp_ip.ip_len); 312 /* Discard ICMP's in response to multicast packets */ 313 if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr))) 314 goto badcode; 315 #ifdef ICMPPRINTFS 316 if (icmpprintfs) 317 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 318 #endif 319 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 320 #if 1 321 /* 322 * MTU discovery: 323 * If we got a needfrag and there is a host route to the 324 * original destination, and the MTU is not locked, then 325 * set the MTU in the route to the suggested new value 326 * (if given) and then notify as usual. The ULPs will 327 * notice that the MTU has changed and adapt accordingly. 328 * If no new MTU was suggested, then we guess a new one 329 * less than the current value. If the new MTU is 330 * unreasonably small (arbitrarily set at 296), then 331 * we reset the MTU to the interface value and enable the 332 * lock bit, indicating that we are no longer doing MTU 333 * discovery. 334 */ 335 if (code == PRC_MSGSIZE) { 336 struct rtentry *rt; 337 int mtu; 338 339 rt = rtalloc1((struct sockaddr *)&icmpsrc, 0, 340 RTF_CLONING | RTF_PRCLONING); 341 if (rt && (rt->rt_flags & RTF_HOST) 342 && !(rt->rt_rmx.rmx_locks & RTV_MTU)) { 343 mtu = ntohs(icp->icmp_nextmtu); 344 if (!mtu) 345 mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu, 346 1); 347 #ifdef DEBUG_MTUDISC 348 printf("MTU for %s reduced to %d\n", 349 inet_ntoa(icmpsrc.sin_addr), mtu); 350 #endif 351 if (mtu < 296) { 352 /* rt->rt_rmx.rmx_mtu = 353 rt->rt_ifp->if_mtu; */ 354 rt->rt_rmx.rmx_locks |= RTV_MTU; 355 } else if (rt->rt_rmx.rmx_mtu > mtu) { 356 rt->rt_rmx.rmx_mtu = mtu; 357 } 358 } 359 if (rt) 360 RTFREE(rt); 361 } 362 363 #endif 364 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; 365 if (ctlfunc) 366 (*ctlfunc)(code, (struct sockaddr *)&icmpsrc, 367 (void *)&icp->icmp_ip); 368 break; 369 370 badcode: 371 icmpstat.icps_badcode++; 372 break; 373 374 case ICMP_ECHO: 375 icp->icmp_type = ICMP_ECHOREPLY; 376 goto reflect; 377 378 case ICMP_TSTAMP: 379 if (icmplen < ICMP_TSLEN) { 380 icmpstat.icps_badlen++; 381 break; 382 } 383 icp->icmp_type = ICMP_TSTAMPREPLY; 384 icp->icmp_rtime = iptime(); 385 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 386 goto reflect; 387 388 case ICMP_MASKREQ: 389 #define satosin(sa) ((struct sockaddr_in *)(sa)) 390 if (icmpmaskrepl == 0) 391 break; 392 /* 393 * We are not able to respond with all ones broadcast 394 * unless we receive it over a point-to-point interface. 395 */ 396 if (icmplen < ICMP_MASKLEN) 397 break; 398 switch (ip->ip_dst.s_addr) { 399 400 case INADDR_BROADCAST: 401 case INADDR_ANY: 402 icmpdst.sin_addr = ip->ip_src; 403 break; 404 405 default: 406 icmpdst.sin_addr = ip->ip_dst; 407 } 408 ia = (struct in_ifaddr *)ifaof_ifpforaddr( 409 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif); 410 if (ia == 0) 411 break; 412 if (ia->ia_ifp == 0) 413 break; 414 icp->icmp_type = ICMP_MASKREPLY; 415 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 416 if (ip->ip_src.s_addr == 0) { 417 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 418 ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr; 419 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 420 ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr; 421 } 422 reflect: 423 ip->ip_len += hlen; /* since ip_input deducts this */ 424 icmpstat.icps_reflect++; 425 icmpstat.icps_outhist[icp->icmp_type]++; 426 icmp_reflect(m); 427 return; 428 429 case ICMP_REDIRECT: 430 if (code > 3) 431 goto badcode; 432 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 433 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) { 434 icmpstat.icps_badlen++; 435 break; 436 } 437 /* 438 * Short circuit routing redirects to force 439 * immediate change in the kernel's routing 440 * tables. The message is also handed to anyone 441 * listening on a raw socket (e.g. the routing 442 * daemon for use in updating its tables). 443 */ 444 icmpgw.sin_addr = ip->ip_src; 445 icmpdst.sin_addr = icp->icmp_gwaddr; 446 #ifdef ICMPPRINTFS 447 if (icmpprintfs) { 448 char buf[4 * sizeof "123"]; 449 strcpy(buf, inet_ntoa(icp->icmp_ip.ip_dst)); 450 451 printf("redirect dst %s to %s\n", 452 buf, inet_ntoa(icp->icmp_gwaddr)); 453 } 454 #endif 455 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 456 rtredirect((struct sockaddr *)&icmpsrc, 457 (struct sockaddr *)&icmpdst, 458 (struct sockaddr *)0, RTF_GATEWAY | RTF_HOST, 459 (struct sockaddr *)&icmpgw, (struct rtentry **)0); 460 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc); 461 break; 462 463 /* 464 * No kernel processing for the following; 465 * just fall through to send to raw listener. 466 */ 467 case ICMP_ECHOREPLY: 468 case ICMP_ROUTERADVERT: 469 case ICMP_ROUTERSOLICIT: 470 case ICMP_TSTAMPREPLY: 471 case ICMP_IREQREPLY: 472 case ICMP_MASKREPLY: 473 default: 474 break; 475 } 476 477 raw: 478 rip_input(m, hlen); 479 return; 480 481 freeit: 482 m_freem(m); 483 } 484 485 /* 486 * Reflect the ip packet back to the source 487 */ 488 static void 489 icmp_reflect(m) 490 struct mbuf *m; 491 { 492 register struct ip *ip = mtod(m, struct ip *); 493 register struct in_ifaddr *ia; 494 struct in_addr t; 495 struct mbuf *opts = 0; 496 int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip); 497 498 if (!in_canforward(ip->ip_src) && 499 ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) != 500 (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { 501 m_freem(m); /* Bad return address */ 502 goto done; /* Ip_output() will check for broadcast */ 503 } 504 t = ip->ip_dst; 505 ip->ip_dst = ip->ip_src; 506 /* 507 * If the incoming packet was addressed directly to us, 508 * use dst as the src for the reply. Otherwise (broadcast 509 * or anonymous), use the address which corresponds 510 * to the incoming interface. 511 */ 512 for (ia = in_ifaddr; ia; ia = ia->ia_next) { 513 if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr) 514 break; 515 if (ia->ia_ifp && (ia->ia_ifp->if_flags & IFF_BROADCAST) && 516 t.s_addr == satosin(&ia->ia_broadaddr)->sin_addr.s_addr) 517 break; 518 } 519 icmpdst.sin_addr = t; 520 if (ia == (struct in_ifaddr *)0) 521 ia = (struct in_ifaddr *)ifaof_ifpforaddr( 522 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif); 523 /* 524 * The following happens if the packet was not addressed to us, 525 * and was received on an interface with no IP address. 526 */ 527 if (ia == (struct in_ifaddr *)0) 528 ia = in_ifaddr; 529 t = IA_SIN(ia)->sin_addr; 530 ip->ip_src = t; 531 ip->ip_ttl = MAXTTL; 532 533 if (optlen > 0) { 534 register u_char *cp; 535 int opt, cnt; 536 u_int len; 537 538 /* 539 * Retrieve any source routing from the incoming packet; 540 * add on any record-route or timestamp options. 541 */ 542 cp = (u_char *) (ip + 1); 543 if ((opts = ip_srcroute()) == 0 && 544 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { 545 opts->m_len = sizeof(struct in_addr); 546 mtod(opts, struct in_addr *)->s_addr = 0; 547 } 548 if (opts) { 549 #ifdef ICMPPRINTFS 550 if (icmpprintfs) 551 printf("icmp_reflect optlen %d rt %d => ", 552 optlen, opts->m_len); 553 #endif 554 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 555 opt = cp[IPOPT_OPTVAL]; 556 if (opt == IPOPT_EOL) 557 break; 558 if (opt == IPOPT_NOP) 559 len = 1; 560 else { 561 len = cp[IPOPT_OLEN]; 562 if (len <= 0 || len > cnt) 563 break; 564 } 565 /* 566 * Should check for overflow, but it "can't happen" 567 */ 568 if (opt == IPOPT_RR || opt == IPOPT_TS || 569 opt == IPOPT_SECURITY) { 570 bcopy((caddr_t)cp, 571 mtod(opts, caddr_t) + opts->m_len, len); 572 opts->m_len += len; 573 } 574 } 575 /* Terminate & pad, if necessary */ 576 cnt = opts->m_len % 4; 577 if (cnt) { 578 for (; cnt < 4; cnt++) { 579 *(mtod(opts, caddr_t) + opts->m_len) = 580 IPOPT_EOL; 581 opts->m_len++; 582 } 583 } 584 #ifdef ICMPPRINTFS 585 if (icmpprintfs) 586 printf("%d\n", opts->m_len); 587 #endif 588 } 589 /* 590 * Now strip out original options by copying rest of first 591 * mbuf's data back, and adjust the IP length. 592 */ 593 ip->ip_len -= optlen; 594 ip->ip_vhl = IP_VHL_BORING; 595 m->m_len -= optlen; 596 if (m->m_flags & M_PKTHDR) 597 m->m_pkthdr.len -= optlen; 598 optlen += sizeof(struct ip); 599 bcopy((caddr_t)ip + optlen, (caddr_t)(ip + 1), 600 (unsigned)(m->m_len - sizeof(struct ip))); 601 } 602 m->m_flags &= ~(M_BCAST|M_MCAST); 603 icmp_send(m, opts); 604 done: 605 if (opts) 606 (void)m_free(opts); 607 } 608 609 /* 610 * Send an icmp packet back to the ip level, 611 * after supplying a checksum. 612 */ 613 static void 614 icmp_send(m, opts) 615 register struct mbuf *m; 616 struct mbuf *opts; 617 { 618 register struct ip *ip = mtod(m, struct ip *); 619 register int hlen; 620 register struct icmp *icp; 621 struct route ro; 622 623 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 624 m->m_data += hlen; 625 m->m_len -= hlen; 626 icp = mtod(m, struct icmp *); 627 icp->icmp_cksum = 0; 628 icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen); 629 m->m_data -= hlen; 630 m->m_len += hlen; 631 #ifdef ICMPPRINTFS 632 if (icmpprintfs) { 633 char buf[4 * sizeof "123"]; 634 strcpy(buf, inet_ntoa(ip->ip_dst)); 635 printf("icmp_send dst %s src %s\n", 636 buf, inet_ntoa(ip->ip_src)); 637 } 638 #endif 639 bzero(&ro, sizeof ro); 640 (void) ip_output(m, opts, &ro, 0, NULL); 641 if (ro.ro_rt) 642 RTFREE(ro.ro_rt); 643 } 644 645 n_time 646 iptime() 647 { 648 struct timeval atv; 649 u_long t; 650 651 microtime(&atv); 652 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 653 return (htonl(t)); 654 } 655 656 #if 1 657 /* 658 * Return the next larger or smaller MTU plateau (table from RFC 1191) 659 * given current value MTU. If DIR is less than zero, a larger plateau 660 * is returned; otherwise, a smaller value is returned. 661 */ 662 static int 663 ip_next_mtu(mtu, dir) 664 int mtu; 665 int dir; 666 { 667 static int mtutab[] = { 668 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296, 669 68, 0 670 }; 671 int i; 672 673 for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) { 674 if (mtu >= mtutab[i]) 675 break; 676 } 677 678 if (dir < 0) { 679 if (i == 0) { 680 return 0; 681 } else { 682 return mtutab[i - 1]; 683 } 684 } else { 685 if (mtutab[i] == 0) { 686 return 0; 687 } else if(mtu > mtutab[i]) { 688 return mtutab[i]; 689 } else { 690 return mtutab[i + 1]; 691 } 692 } 693 } 694 #endif 695