1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * 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 project 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 PROJECT 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 PROJECT 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 * $KAME: ip6_forward.c,v 1.69 2001/05/17 03:48:30 itojun Exp $ 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_inet.h" 36 #include "opt_inet6.h" 37 #include "opt_ipsec.h" 38 #include "opt_ipstealth.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/malloc.h> 43 #include <sys/mbuf.h> 44 #include <sys/domain.h> 45 #include <sys/protosw.h> 46 #include <sys/socket.h> 47 #include <sys/errno.h> 48 #include <sys/time.h> 49 #include <sys/kernel.h> 50 #include <sys/syslog.h> 51 52 #include <net/if.h> 53 #include <net/route.h> 54 #include <net/pfil.h> 55 56 #include <netinet/in.h> 57 #include <netinet/in_var.h> 58 #include <netinet/in_systm.h> 59 #include <netinet/ip.h> 60 #include <netinet/ip_var.h> 61 #include <netinet6/in6_var.h> 62 #include <netinet/ip6.h> 63 #include <netinet6/ip6_var.h> 64 #include <netinet6/scope6_var.h> 65 #include <netinet/icmp6.h> 66 #include <netinet6/nd6.h> 67 68 #include <netinet/in_pcb.h> 69 70 #ifdef IPSEC 71 #include <netipsec/ipsec.h> 72 #include <netipsec/ipsec6.h> 73 #include <netipsec/key.h> 74 #endif /* IPSEC */ 75 76 #include <netinet6/ip6protosw.h> 77 78 struct route_in6 ip6_forward_rt; 79 80 /* 81 * Forward a packet. If some error occurs return the sender 82 * an icmp packet. Note we can't always generate a meaningful 83 * icmp message because icmp doesn't have a large enough repertoire 84 * of codes and types. 85 * 86 * If not forwarding, just drop the packet. This could be confusing 87 * if ipforwarding was zero but some routing protocol was advancing 88 * us as a gateway to somewhere. However, we must let the routing 89 * protocol deal with that. 90 * 91 */ 92 void 93 ip6_forward(struct mbuf *m, int srcrt) 94 { 95 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 96 struct sockaddr_in6 *dst = NULL; 97 struct rtentry *rt = NULL; 98 int error, type = 0, code = 0; 99 struct mbuf *mcopy = NULL; 100 struct ifnet *origifp; /* maybe unnecessary */ 101 u_int32_t inzone, outzone; 102 struct in6_addr src_in6, dst_in6; 103 #ifdef IPSEC 104 struct secpolicy *sp = NULL; 105 int ipsecrt = 0; 106 #endif 107 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 108 109 GIANT_REQUIRED; /* XXX bz: ip6_forward_rt */ 110 111 #ifdef IPSEC 112 /* 113 * Check AH/ESP integrity. 114 */ 115 /* 116 * Don't increment ip6s_cantforward because this is the check 117 * before forwarding packet actually. 118 */ 119 if (ipsec6_in_reject(m, NULL)) { 120 ipsec6stat.in_polvio++; 121 m_freem(m); 122 return; 123 } 124 #endif /* IPSEC */ 125 126 /* 127 * Do not forward packets to multicast destination (should be handled 128 * by ip6_mforward(). 129 * Do not forward packets with unspecified source. It was discussed 130 * in July 2000, on the ipngwg mailing list. 131 */ 132 if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || 133 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 134 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { 135 ip6stat.ip6s_cantforward++; 136 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 137 if (ip6_log_time + ip6_log_interval < time_second) { 138 ip6_log_time = time_second; 139 log(LOG_DEBUG, 140 "cannot forward " 141 "from %s to %s nxt %d received on %s\n", 142 ip6_sprintf(ip6bufs, &ip6->ip6_src), 143 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 144 ip6->ip6_nxt, 145 if_name(m->m_pkthdr.rcvif)); 146 } 147 m_freem(m); 148 return; 149 } 150 151 #ifdef IPSTEALTH 152 if (!ip6stealth) { 153 #endif 154 if (ip6->ip6_hlim <= IPV6_HLIMDEC) { 155 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 156 icmp6_error(m, ICMP6_TIME_EXCEEDED, 157 ICMP6_TIME_EXCEED_TRANSIT, 0); 158 return; 159 } 160 ip6->ip6_hlim -= IPV6_HLIMDEC; 161 162 #ifdef IPSTEALTH 163 } 164 #endif 165 166 /* 167 * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - 168 * size of IPv6 + ICMPv6 headers) bytes of the packet in case 169 * we need to generate an ICMP6 message to the src. 170 * Thanks to M_EXT, in most cases copy will not occur. 171 * 172 * It is important to save it before IPsec processing as IPsec 173 * processing may modify the mbuf. 174 */ 175 mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); 176 177 #ifdef IPSEC 178 /* get a security policy for this packet */ 179 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 180 IP_FORWARDING, &error); 181 if (sp == NULL) { 182 ipsec6stat.out_inval++; 183 ip6stat.ip6s_cantforward++; 184 if (mcopy) { 185 #if 0 186 /* XXX: what icmp ? */ 187 #else 188 m_freem(mcopy); 189 #endif 190 } 191 m_freem(m); 192 return; 193 } 194 195 error = 0; 196 197 /* check policy */ 198 switch (sp->policy) { 199 case IPSEC_POLICY_DISCARD: 200 /* 201 * This packet is just discarded. 202 */ 203 ipsec6stat.out_polvio++; 204 ip6stat.ip6s_cantforward++; 205 KEY_FREESP(&sp); 206 if (mcopy) { 207 #if 0 208 /* XXX: what icmp ? */ 209 #else 210 m_freem(mcopy); 211 #endif 212 } 213 m_freem(m); 214 return; 215 216 case IPSEC_POLICY_BYPASS: 217 case IPSEC_POLICY_NONE: 218 /* no need to do IPsec. */ 219 KEY_FREESP(&sp); 220 goto skip_ipsec; 221 222 case IPSEC_POLICY_IPSEC: 223 if (sp->req == NULL) { 224 /* XXX should be panic ? */ 225 printf("ip6_forward: No IPsec request specified.\n"); 226 ip6stat.ip6s_cantforward++; 227 KEY_FREESP(&sp); 228 if (mcopy) { 229 #if 0 230 /* XXX: what icmp ? */ 231 #else 232 m_freem(mcopy); 233 #endif 234 } 235 m_freem(m); 236 return; 237 } 238 /* do IPsec */ 239 break; 240 241 case IPSEC_POLICY_ENTRUST: 242 default: 243 /* should be panic ?? */ 244 printf("ip6_forward: Invalid policy found. %d\n", sp->policy); 245 KEY_FREESP(&sp); 246 goto skip_ipsec; 247 } 248 249 { 250 struct ipsecrequest *isr = NULL; 251 struct ipsec_output_state state; 252 253 /* 254 * when the kernel forwards a packet, it is not proper to apply 255 * IPsec transport mode to the packet is not proper. this check 256 * avoid from this. 257 * at present, if there is even a transport mode SA request in the 258 * security policy, the kernel does not apply IPsec to the packet. 259 * this check is not enough because the following case is valid. 260 * ipsec esp/tunnel/xxx-xxx/require esp/transport//require; 261 */ 262 for (isr = sp->req; isr; isr = isr->next) { 263 if (isr->saidx.mode == IPSEC_MODE_ANY) 264 goto doipsectunnel; 265 if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 266 goto doipsectunnel; 267 } 268 269 /* 270 * if there's no need for tunnel mode IPsec, skip. 271 */ 272 if (!isr) 273 goto skip_ipsec; 274 275 doipsectunnel: 276 /* 277 * All the extension headers will become inaccessible 278 * (since they can be encrypted). 279 * Don't panic, we need no more updates to extension headers 280 * on inner IPv6 packet (since they are now encapsulated). 281 * 282 * IPv6 [ESP|AH] IPv6 [extension headers] payload 283 */ 284 bzero(&state, sizeof(state)); 285 state.m = m; 286 state.ro = NULL; /* update at ipsec6_output_tunnel() */ 287 state.dst = NULL; /* update at ipsec6_output_tunnel() */ 288 289 error = ipsec6_output_tunnel(&state, sp, 0); 290 291 m = state.m; 292 KEY_FREESP(&sp); 293 294 if (error) { 295 /* mbuf is already reclaimed in ipsec6_output_tunnel. */ 296 switch (error) { 297 case EHOSTUNREACH: 298 case ENETUNREACH: 299 case EMSGSIZE: 300 case ENOBUFS: 301 case ENOMEM: 302 break; 303 default: 304 printf("ip6_output (ipsec): error code %d\n", error); 305 /* FALLTHROUGH */ 306 case ENOENT: 307 /* don't show these error codes to the user */ 308 break; 309 } 310 ip6stat.ip6s_cantforward++; 311 if (mcopy) { 312 #if 0 313 /* XXX: what icmp ? */ 314 #else 315 m_freem(mcopy); 316 #endif 317 } 318 m_freem(m); 319 return; 320 } else { 321 /* 322 * In the FAST IPSec case we have already 323 * re-injected the packet and it has been freed 324 * by the ipsec_done() function. So, just clean 325 * up after ourselves. 326 */ 327 m = NULL; 328 goto freecopy; 329 } 330 331 if ((m != NULL) && (ip6 != mtod(m, struct ip6_hdr *)) ){ 332 /* 333 * now tunnel mode headers are added. we are originating 334 * packet instead of forwarding the packet. 335 */ 336 ip6_output(m, NULL, NULL, IPV6_FORWARDING/*XXX*/, NULL, NULL, 337 NULL); 338 goto freecopy; 339 } 340 341 /* adjust pointer */ 342 dst = (struct sockaddr_in6 *)state.dst; 343 rt = state.ro ? state.ro->ro_rt : NULL; 344 if (dst != NULL && rt != NULL) 345 ipsecrt = 1; 346 } 347 skip_ipsec: 348 #endif /* IPSEC */ 349 350 #ifdef IPSEC 351 if (ipsecrt) 352 goto skip_routing; 353 #endif 354 355 dst = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 356 if (!srcrt) { 357 /* ip6_forward_rt.ro_dst.sin6_addr is equal to ip6->ip6_dst */ 358 if (ip6_forward_rt.ro_rt == 0 || 359 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) == 0) { 360 if (ip6_forward_rt.ro_rt) { 361 RTFREE(ip6_forward_rt.ro_rt); 362 ip6_forward_rt.ro_rt = 0; 363 } 364 365 /* this probably fails but give it a try again */ 366 rtalloc((struct route *)&ip6_forward_rt); 367 } 368 369 if (ip6_forward_rt.ro_rt == 0) { 370 ip6stat.ip6s_noroute++; 371 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 372 if (mcopy) { 373 icmp6_error(mcopy, ICMP6_DST_UNREACH, 374 ICMP6_DST_UNREACH_NOROUTE, 0); 375 } 376 m_freem(m); 377 return; 378 } 379 } else if ((rt = ip6_forward_rt.ro_rt) == 0 || 380 !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr)) { 381 if (ip6_forward_rt.ro_rt) { 382 RTFREE(ip6_forward_rt.ro_rt); 383 ip6_forward_rt.ro_rt = 0; 384 } 385 bzero(dst, sizeof(*dst)); 386 dst->sin6_len = sizeof(struct sockaddr_in6); 387 dst->sin6_family = AF_INET6; 388 dst->sin6_addr = ip6->ip6_dst; 389 390 rtalloc((struct route *)&ip6_forward_rt); 391 if (ip6_forward_rt.ro_rt == 0) { 392 ip6stat.ip6s_noroute++; 393 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 394 if (mcopy) { 395 icmp6_error(mcopy, ICMP6_DST_UNREACH, 396 ICMP6_DST_UNREACH_NOROUTE, 0); 397 } 398 m_freem(m); 399 return; 400 } 401 } 402 rt = ip6_forward_rt.ro_rt; 403 #ifdef IPSEC 404 skip_routing:; 405 #endif 406 407 /* 408 * Source scope check: if a packet can't be delivered to its 409 * destination for the reason that the destination is beyond the scope 410 * of the source address, discard the packet and return an icmp6 411 * destination unreachable error with Code 2 (beyond scope of source 412 * address). We use a local copy of ip6_src, since in6_setscope() 413 * will possibly modify its first argument. 414 * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1] 415 */ 416 src_in6 = ip6->ip6_src; 417 if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) { 418 /* XXX: this should not happen */ 419 ip6stat.ip6s_cantforward++; 420 ip6stat.ip6s_badscope++; 421 m_freem(m); 422 return; 423 } 424 if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { 425 ip6stat.ip6s_cantforward++; 426 ip6stat.ip6s_badscope++; 427 m_freem(m); 428 return; 429 } 430 if (inzone != outzone 431 #ifdef IPSEC 432 && !ipsecrt 433 #endif 434 ) { 435 ip6stat.ip6s_cantforward++; 436 ip6stat.ip6s_badscope++; 437 in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); 438 439 if (ip6_log_time + ip6_log_interval < time_second) { 440 ip6_log_time = time_second; 441 log(LOG_DEBUG, 442 "cannot forward " 443 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 444 ip6_sprintf(ip6bufs, &ip6->ip6_src), 445 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 446 ip6->ip6_nxt, 447 if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); 448 } 449 if (mcopy) 450 icmp6_error(mcopy, ICMP6_DST_UNREACH, 451 ICMP6_DST_UNREACH_BEYONDSCOPE, 0); 452 m_freem(m); 453 return; 454 } 455 456 /* 457 * Destination scope check: if a packet is going to break the scope 458 * zone of packet's destination address, discard it. This case should 459 * usually be prevented by appropriately-configured routing table, but 460 * we need an explicit check because we may mistakenly forward the 461 * packet to a different zone by (e.g.) a default route. 462 */ 463 dst_in6 = ip6->ip6_dst; 464 if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || 465 in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || 466 inzone != outzone) { 467 ip6stat.ip6s_cantforward++; 468 ip6stat.ip6s_badscope++; 469 m_freem(m); 470 return; 471 } 472 473 if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { 474 in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); 475 if (mcopy) { 476 u_long mtu; 477 #ifdef IPSEC 478 struct secpolicy *sp; 479 int ipsecerror; 480 size_t ipsechdrsiz; 481 #endif /* IPSEC */ 482 483 mtu = IN6_LINKMTU(rt->rt_ifp); 484 #ifdef IPSEC 485 /* 486 * When we do IPsec tunnel ingress, we need to play 487 * with the link value (decrement IPsec header size 488 * from mtu value). The code is much simpler than v4 489 * case, as we have the outgoing interface for 490 * encapsulated packet as "rt->rt_ifp". 491 */ 492 sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, 493 IP_FORWARDING, &ipsecerror); 494 if (sp) { 495 ipsechdrsiz = ipsec6_hdrsiz(mcopy, 496 IPSEC_DIR_OUTBOUND, NULL); 497 if (ipsechdrsiz < mtu) 498 mtu -= ipsechdrsiz; 499 } 500 501 /* 502 * if mtu becomes less than minimum MTU, 503 * tell minimum MTU (and I'll need to fragment it). 504 */ 505 if (mtu < IPV6_MMTU) 506 mtu = IPV6_MMTU; 507 #endif /* IPSEC */ 508 icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); 509 } 510 m_freem(m); 511 return; 512 } 513 514 if (rt->rt_flags & RTF_GATEWAY) 515 dst = (struct sockaddr_in6 *)rt->rt_gateway; 516 517 /* 518 * If we are to forward the packet using the same interface 519 * as one we got the packet from, perhaps we should send a redirect 520 * to sender to shortcut a hop. 521 * Only send redirect if source is sending directly to us, 522 * and if packet was not source routed (or has any options). 523 * Also, don't send redirect if forwarding using a route 524 * modified by a redirect. 525 */ 526 if (ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && 527 #ifdef IPSEC 528 !ipsecrt && 529 #endif /* IPSEC */ 530 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { 531 if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { 532 /* 533 * If the incoming interface is equal to the outgoing 534 * one, and the link attached to the interface is 535 * point-to-point, then it will be highly probable 536 * that a routing loop occurs. Thus, we immediately 537 * drop the packet and send an ICMPv6 error message. 538 * 539 * type/code is based on suggestion by Rich Draves. 540 * not sure if it is the best pick. 541 */ 542 icmp6_error(mcopy, ICMP6_DST_UNREACH, 543 ICMP6_DST_UNREACH_ADDR, 0); 544 m_freem(m); 545 return; 546 } 547 type = ND_REDIRECT; 548 } 549 550 /* 551 * Fake scoped addresses. Note that even link-local source or 552 * destinaion can appear, if the originating node just sends the 553 * packet to us (without address resolution for the destination). 554 * Since both icmp6_error and icmp6_redirect_output fill the embedded 555 * link identifiers, we can do this stuff after making a copy for 556 * returning an error. 557 */ 558 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { 559 /* 560 * See corresponding comments in ip6_output. 561 * XXX: but is it possible that ip6_forward() sends a packet 562 * to a loopback interface? I don't think so, and thus 563 * I bark here. (jinmei@kame.net) 564 * XXX: it is common to route invalid packets to loopback. 565 * also, the codepath will be visited on use of ::1 in 566 * rthdr. (itojun) 567 */ 568 #if 1 569 if (0) 570 #else 571 if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) 572 #endif 573 { 574 printf("ip6_forward: outgoing interface is loopback. " 575 "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 576 ip6_sprintf(ip6bufs, &ip6->ip6_src), 577 ip6_sprintf(ip6bufd, &ip6->ip6_dst), 578 ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), 579 if_name(rt->rt_ifp)); 580 } 581 582 /* we can just use rcvif in forwarding. */ 583 origifp = m->m_pkthdr.rcvif; 584 } 585 else 586 origifp = rt->rt_ifp; 587 /* 588 * clear embedded scope identifiers if necessary. 589 * in6_clearscope will touch the addresses only when necessary. 590 */ 591 in6_clearscope(&ip6->ip6_src); 592 in6_clearscope(&ip6->ip6_dst); 593 594 /* Jump over all PFIL processing if hooks are not active. */ 595 if (!PFIL_HOOKED(&inet6_pfil_hook)) 596 goto pass; 597 598 /* Run through list of hooks for output packets. */ 599 error = pfil_run_hooks(&inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL); 600 if (error != 0) 601 goto senderr; 602 if (m == NULL) 603 goto freecopy; 604 ip6 = mtod(m, struct ip6_hdr *); 605 606 pass: 607 error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); 608 if (error) { 609 in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); 610 ip6stat.ip6s_cantforward++; 611 } else { 612 ip6stat.ip6s_forward++; 613 in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); 614 if (type) 615 ip6stat.ip6s_redirectsent++; 616 else { 617 if (mcopy) 618 goto freecopy; 619 } 620 } 621 622 senderr: 623 if (mcopy == NULL) 624 return; 625 switch (error) { 626 case 0: 627 if (type == ND_REDIRECT) { 628 icmp6_redirect_output(mcopy, rt); 629 return; 630 } 631 goto freecopy; 632 633 case EMSGSIZE: 634 /* xxx MTU is constant in PPP? */ 635 goto freecopy; 636 637 case ENOBUFS: 638 /* Tell source to slow down like source quench in IP? */ 639 goto freecopy; 640 641 case ENETUNREACH: /* shouldn't happen, checked above */ 642 case EHOSTUNREACH: 643 case ENETDOWN: 644 case EHOSTDOWN: 645 default: 646 type = ICMP6_DST_UNREACH; 647 code = ICMP6_DST_UNREACH_ADDR; 648 break; 649 } 650 icmp6_error(mcopy, type, code, 0); 651 return; 652 653 freecopy: 654 m_freem(mcopy); 655 return; 656 } 657