1 /* $FreeBSD: src/sys/netinet6/frag6.c,v 1.2.2.6 2002/04/28 05:40:26 suz Exp $ */ 2 /* $KAME: frag6.c,v 1.33 2002/01/07 11:34:48 kjc Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/malloc.h> 36 #include <sys/mbuf.h> 37 #include <sys/domain.h> 38 #include <sys/protosw.h> 39 #include <sys/socket.h> 40 #include <sys/errno.h> 41 #include <sys/time.h> 42 #include <sys/kernel.h> 43 #include <sys/syslog.h> 44 #include <sys/thread2.h> 45 46 #include <net/if.h> 47 #include <net/route.h> 48 49 #include <netinet/in.h> 50 #include <netinet/in_var.h> 51 #include <netinet/ip6.h> 52 #include <netinet6/ip6_var.h> 53 #include <netinet/icmp6.h> 54 55 #include <net/net_osdep.h> 56 57 /* 58 * Define it to get a correct behavior on per-interface statistics. 59 * You will need to perform an extra routing table lookup, per fragment, 60 * to do it. This may, or may not be, a performance hit. 61 */ 62 #define IN6_IFSTAT_STRICT 63 64 static void frag6_enq (struct ip6asfrag *, struct ip6asfrag *); 65 static void frag6_deq (struct ip6asfrag *); 66 static void frag6_insque (struct ip6q *, struct ip6q *); 67 static void frag6_remque (struct ip6q *); 68 static void frag6_freef (struct ip6q *); 69 70 /* XXX we eventually need splreass6, or some real semaphore */ 71 int frag6_doing_reass; 72 u_int frag6_nfragpackets; 73 u_int frag6_nfrags; 74 struct ip6q ip6q; /* ip6 reassemble queue */ 75 76 /* FreeBSD tweak */ 77 MALLOC_DEFINE(M_FTABLE, "fragment", "fragment reassembly header"); 78 79 /* 80 * Initialise reassembly queue and fragment identifier. 81 */ 82 void 83 frag6_init(void) 84 { 85 struct timeval tv; 86 87 ip6_maxfragpackets = nmbclusters / 4; 88 ip6_maxfrags = nmbclusters / 4; 89 90 /* 91 * in many cases, random() here does NOT return random number 92 * as initialization during bootstrap time occur in fixed order. 93 */ 94 microtime(&tv); 95 ip6_id = krandom() ^ tv.tv_usec; 96 ip6q.ip6q_next = ip6q.ip6q_prev = &ip6q; 97 } 98 99 /* 100 * In RFC2460, fragment and reassembly rule do not agree with each other, 101 * in terms of next header field handling in fragment header. 102 * While the sender will use the same value for all of the fragmented packets, 103 * receiver is suggested not to check the consistency. 104 * 105 * fragment rule (p20): 106 * (2) A Fragment header containing: 107 * The Next Header value that identifies the first header of 108 * the Fragmentable Part of the original packet. 109 * -> next header field is same for all fragments 110 * 111 * reassembly rule (p21): 112 * The Next Header field of the last header of the Unfragmentable 113 * Part is obtained from the Next Header field of the first 114 * fragment's Fragment header. 115 * -> should grab it from the first fragment only 116 * 117 * The following note also contradicts with fragment rule - noone is going to 118 * send different fragment with different next header field. 119 * 120 * additional note (p22): 121 * The Next Header values in the Fragment headers of different 122 * fragments of the same original packet may differ. Only the value 123 * from the Offset zero fragment packet is used for reassembly. 124 * -> should grab it from the first fragment only 125 * 126 * There is no explicit reason given in the RFC. Historical reason maybe? 127 */ 128 /* 129 * Fragment input 130 */ 131 int 132 frag6_input(struct mbuf **mp, int *offp, int proto) 133 { 134 struct mbuf *m = *mp, *t; 135 struct ip6_hdr *ip6; 136 struct ip6_frag *ip6f; 137 struct ip6q *q6; 138 struct ip6asfrag *af6, *ip6af, *af6dwn; 139 int offset = *offp, nxt, i, next; 140 int first_frag = 0; 141 int fragoff, frgpartlen; /* must be larger than u_int16_t */ 142 struct ifnet *dstifp; 143 #ifdef IN6_IFSTAT_STRICT 144 static struct route_in6 ro; 145 struct sockaddr_in6 *dst; 146 #endif 147 148 ip6 = mtod(m, struct ip6_hdr *); 149 #ifndef PULLDOWN_TEST 150 IP6_EXTHDR_CHECK(m, offset, sizeof(struct ip6_frag), IPPROTO_DONE); 151 ip6f = (struct ip6_frag *)((caddr_t)ip6 + offset); 152 #else 153 IP6_EXTHDR_GET(ip6f, struct ip6_frag *, m, offset, sizeof(*ip6f)); 154 if (ip6f == NULL) 155 return IPPROTO_DONE; 156 #endif 157 158 dstifp = NULL; 159 #ifdef IN6_IFSTAT_STRICT 160 /* find the destination interface of the packet. */ 161 dst = (struct sockaddr_in6 *)&ro.ro_dst; 162 if (ro.ro_rt && 163 (!(ro.ro_rt->rt_flags & RTF_UP) || 164 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_dst))) { 165 rtfree(ro.ro_rt); 166 ro.ro_rt = NULL; 167 } 168 if (ro.ro_rt == NULL) { 169 bzero(dst, sizeof(*dst)); 170 dst->sin6_family = AF_INET6; 171 dst->sin6_len = sizeof(struct sockaddr_in6); 172 dst->sin6_addr = ip6->ip6_dst; 173 } 174 rtalloc((struct route *)&ro); 175 if (ro.ro_rt != NULL && ro.ro_rt->rt_ifa != NULL) 176 dstifp = ((struct in6_ifaddr *)ro.ro_rt->rt_ifa)->ia_ifp; 177 #else 178 /* we are violating the spec, this is not the destination interface */ 179 if (m->m_flags & M_PKTHDR) 180 dstifp = m->m_pkthdr.rcvif; 181 #endif 182 183 /* jumbo payload can't contain a fragment header */ 184 if (ip6->ip6_plen == 0) { 185 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, offset); 186 in6_ifstat_inc(dstifp, ifs6_reass_fail); 187 return IPPROTO_DONE; 188 } 189 190 /* 191 * check whether fragment packet's fragment length is 192 * multiple of 8 octets. 193 * sizeof(struct ip6_frag) == 8 194 * sizeof(struct ip6_hdr) = 40 195 */ 196 if ((ip6f->ip6f_offlg & IP6F_MORE_FRAG) && 197 (((ntohs(ip6->ip6_plen) - offset) & 0x7) != 0)) { 198 icmp6_error(m, ICMP6_PARAM_PROB, 199 ICMP6_PARAMPROB_HEADER, 200 offsetof(struct ip6_hdr, ip6_plen)); 201 in6_ifstat_inc(dstifp, ifs6_reass_fail); 202 return IPPROTO_DONE; 203 } 204 205 ip6stat.ip6s_fragments++; 206 in6_ifstat_inc(dstifp, ifs6_reass_reqd); 207 208 /* offset now points to data portion */ 209 offset += sizeof(struct ip6_frag); 210 211 frag6_doing_reass = 1; 212 213 /* 214 * Enforce upper bound on number of fragments. 215 * If maxfrag is 0, never accept fragments. 216 * If maxfrag is -1, accept all fragments without limitation. 217 */ 218 if (ip6_maxfrags < 0) 219 ; 220 else if (frag6_nfrags >= (u_int)ip6_maxfrags) 221 goto dropfrag; 222 223 for (q6 = ip6q.ip6q_next; q6 != &ip6q; q6 = q6->ip6q_next) 224 if (ip6f->ip6f_ident == q6->ip6q_ident && 225 IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &q6->ip6q_src) && 226 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &q6->ip6q_dst)) 227 break; 228 229 if (q6 == &ip6q) { 230 /* 231 * the first fragment to arrive, create a reassembly queue. 232 */ 233 first_frag = 1; 234 235 /* 236 * Enforce upper bound on number of fragmented packets 237 * for which we attempt reassembly; 238 * If maxfrag is 0, never accept fragments. 239 * If maxfrag is -1, accept all fragments without limitation. 240 */ 241 if (ip6_maxfragpackets < 0) 242 ; 243 else if (frag6_nfragpackets >= (u_int)ip6_maxfragpackets) 244 goto dropfrag; 245 frag6_nfragpackets++; 246 q6 = (struct ip6q *)kmalloc(sizeof(struct ip6q), M_FTABLE, 247 M_NOWAIT | M_ZERO); 248 if (q6 == NULL) 249 goto dropfrag; 250 251 frag6_insque(q6, &ip6q); 252 253 /* ip6q_nxt will be filled afterwards, from 1st fragment */ 254 q6->ip6q_down = q6->ip6q_up = (struct ip6asfrag *)q6; 255 #ifdef notyet 256 q6->ip6q_nxtp = (u_char *)nxtp; 257 #endif 258 q6->ip6q_ident = ip6f->ip6f_ident; 259 q6->ip6q_arrive = 0; /* Is it used anywhere? */ 260 q6->ip6q_ttl = IPV6_FRAGTTL; 261 q6->ip6q_src = ip6->ip6_src; 262 q6->ip6q_dst = ip6->ip6_dst; 263 q6->ip6q_unfrglen = -1; /* The 1st fragment has not arrived. */ 264 q6->ip6q_nfrag = 0; 265 } 266 267 /* 268 * If it's the 1st fragment, record the length of the 269 * unfragmentable part and the next header of the fragment header. 270 */ 271 fragoff = ntohs(ip6f->ip6f_offlg & IP6F_OFF_MASK); 272 if (fragoff == 0) { 273 q6->ip6q_unfrglen = offset - sizeof(struct ip6_hdr) 274 - sizeof(struct ip6_frag); 275 q6->ip6q_nxt = ip6f->ip6f_nxt; 276 } 277 278 /* 279 * Check that the reassembled packet would not exceed 65535 bytes 280 * in size. 281 * If it would exceed, discard the fragment and return an ICMP error. 282 */ 283 frgpartlen = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen) - offset; 284 if (q6->ip6q_unfrglen >= 0) { 285 /* The 1st fragment has already arrived. */ 286 if (q6->ip6q_unfrglen + fragoff + frgpartlen > IPV6_MAXPACKET) { 287 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 288 offset - sizeof(struct ip6_frag) + 289 offsetof(struct ip6_frag, ip6f_offlg)); 290 frag6_doing_reass = 0; 291 return (IPPROTO_DONE); 292 } 293 } 294 else if (fragoff + frgpartlen > IPV6_MAXPACKET) { 295 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 296 offset - sizeof(struct ip6_frag) + 297 offsetof(struct ip6_frag, ip6f_offlg)); 298 frag6_doing_reass = 0; 299 return (IPPROTO_DONE); 300 } 301 /* 302 * If it's the first fragment, do the above check for each 303 * fragment already stored in the reassembly queue. 304 */ 305 if (fragoff == 0) { 306 for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; 307 af6 = af6dwn) { 308 af6dwn = af6->ip6af_down; 309 310 if (q6->ip6q_unfrglen + af6->ip6af_off + af6->ip6af_frglen > 311 IPV6_MAXPACKET) { 312 struct mbuf *merr = IP6_REASS_MBUF(af6); 313 struct ip6_hdr *ip6err; 314 int erroff = af6->ip6af_offset; 315 316 /* dequeue the fragment. */ 317 frag6_deq(af6); 318 kfree(af6, M_FTABLE); 319 320 /* adjust pointer. */ 321 ip6err = mtod(merr, struct ip6_hdr *); 322 323 /* 324 * Restore source and destination addresses 325 * in the erroneous IPv6 header. 326 */ 327 ip6err->ip6_src = q6->ip6q_src; 328 ip6err->ip6_dst = q6->ip6q_dst; 329 330 icmp6_error(merr, ICMP6_PARAM_PROB, 331 ICMP6_PARAMPROB_HEADER, 332 erroff - sizeof(struct ip6_frag) + 333 offsetof(struct ip6_frag, ip6f_offlg)); 334 } 335 } 336 } 337 338 ip6af = (struct ip6asfrag *)kmalloc(sizeof(struct ip6asfrag), M_FTABLE, 339 M_NOWAIT | M_ZERO); 340 if (ip6af == NULL) 341 goto dropfrag; 342 ip6af->ip6af_head = ip6->ip6_flow; 343 ip6af->ip6af_len = ip6->ip6_plen; 344 ip6af->ip6af_nxt = ip6->ip6_nxt; 345 ip6af->ip6af_hlim = ip6->ip6_hlim; 346 ip6af->ip6af_mff = ip6f->ip6f_offlg & IP6F_MORE_FRAG; 347 ip6af->ip6af_off = fragoff; 348 ip6af->ip6af_frglen = frgpartlen; 349 ip6af->ip6af_offset = offset; 350 IP6_REASS_MBUF(ip6af) = m; 351 352 if (first_frag) { 353 af6 = (struct ip6asfrag *)q6; 354 goto insert; 355 } 356 357 /* 358 * Find a segment which begins after this one does. 359 */ 360 for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; 361 af6 = af6->ip6af_down) 362 if (af6->ip6af_off > ip6af->ip6af_off) 363 break; 364 365 /* 366 * RFC 5722: Drop overlapping fragments 367 */ 368 if (af6->ip6af_up != (struct ip6asfrag *)q6) { 369 i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen 370 - ip6af->ip6af_off; 371 if (i > 0) { 372 kfree(ip6af, M_FTABLE); 373 goto dropfrag; 374 } 375 } 376 if (af6 != (struct ip6asfrag *)q6) { 377 i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off; 378 if (i > 0) { 379 kfree(ip6af, M_FTABLE); 380 goto dropfrag; 381 } 382 } 383 384 insert: 385 386 /* 387 * Stick new segment in its place; 388 * check for complete reassembly. 389 * Move to front of packet queue, as we are 390 * the most recently active fragmented packet. 391 */ 392 frag6_enq(ip6af, af6->ip6af_up); 393 frag6_nfrags++; 394 q6->ip6q_nfrag++; 395 #if 0 /* xxx */ 396 if (q6 != ip6q.ip6q_next) { 397 frag6_remque(q6); 398 frag6_insque(q6, &ip6q); 399 } 400 #endif 401 next = 0; 402 for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; 403 af6 = af6->ip6af_down) { 404 if (af6->ip6af_off != next) { 405 frag6_doing_reass = 0; 406 return IPPROTO_DONE; 407 } 408 next += af6->ip6af_frglen; 409 } 410 if (af6->ip6af_up->ip6af_mff) { 411 frag6_doing_reass = 0; 412 return IPPROTO_DONE; 413 } 414 415 /* 416 * Reassembly is complete; concatenate fragments. 417 */ 418 ip6af = q6->ip6q_down; 419 t = m = IP6_REASS_MBUF(ip6af); 420 af6 = ip6af->ip6af_down; 421 frag6_deq(ip6af); 422 while (af6 != (struct ip6asfrag *)q6) { 423 af6dwn = af6->ip6af_down; 424 frag6_deq(af6); 425 while (t->m_next) 426 t = t->m_next; 427 t->m_next = IP6_REASS_MBUF(af6); 428 m_adj(t->m_next, af6->ip6af_offset); 429 kfree(af6, M_FTABLE); 430 af6 = af6dwn; 431 } 432 433 /* adjust offset to point where the original next header starts */ 434 offset = ip6af->ip6af_offset - sizeof(struct ip6_frag); 435 kfree(ip6af, M_FTABLE); 436 ip6 = mtod(m, struct ip6_hdr *); 437 ip6->ip6_plen = htons((u_short)next + offset - sizeof(struct ip6_hdr)); 438 ip6->ip6_src = q6->ip6q_src; 439 ip6->ip6_dst = q6->ip6q_dst; 440 nxt = q6->ip6q_nxt; 441 #ifdef notyet 442 *q6->ip6q_nxtp = (u_char)(nxt & 0xff); 443 #endif 444 445 /* 446 * Delete frag6 header with as a few cost as possible. 447 */ 448 if (offset < m->m_len) { 449 ovbcopy((caddr_t)ip6, (caddr_t)ip6 + sizeof(struct ip6_frag), 450 offset); 451 m->m_data += sizeof(struct ip6_frag); 452 m->m_len -= sizeof(struct ip6_frag); 453 } else { 454 /* this comes with no copy if the boundary is on cluster */ 455 if ((t = m_split(m, offset, M_NOWAIT)) == NULL) { 456 frag6_remque(q6); 457 frag6_nfrags -= q6->ip6q_nfrag; 458 kfree(q6, M_FTABLE); 459 frag6_nfragpackets--; 460 goto dropfrag; 461 } 462 m_adj(t, sizeof(struct ip6_frag)); 463 m_cat(m, t); 464 } 465 466 /* 467 * Store NXT to the original. 468 */ 469 { 470 char *prvnxtp = ip6_get_prevhdr(m, offset); /* XXX */ 471 *prvnxtp = nxt; 472 } 473 474 frag6_remque(q6); 475 frag6_nfrags -= q6->ip6q_nfrag; 476 kfree(q6, M_FTABLE); 477 frag6_nfragpackets--; 478 479 if (m->m_flags & M_PKTHDR) { /* Isn't it always true? */ 480 int plen = 0; 481 for (t = m; t; t = t->m_next) 482 plen += t->m_len; 483 m->m_pkthdr.len = plen; 484 } 485 486 ip6stat.ip6s_reassembled++; 487 in6_ifstat_inc(dstifp, ifs6_reass_ok); 488 489 /* 490 * Reassembly complete, return the next protocol. 491 * Be sure to clear M_HASH to force the packet 492 * to be re-characterized. 493 */ 494 m->m_flags &= ~M_HASH; 495 496 *mp = m; 497 *offp = offset; 498 499 frag6_doing_reass = 0; 500 return nxt; 501 502 dropfrag: 503 in6_ifstat_inc(dstifp, ifs6_reass_fail); 504 ip6stat.ip6s_fragdropped++; 505 m_freem(m); 506 frag6_doing_reass = 0; 507 return IPPROTO_DONE; 508 } 509 510 /* 511 * Free a fragment reassembly header and all 512 * associated datagrams. 513 */ 514 static void 515 frag6_freef(struct ip6q *q6) 516 { 517 struct ip6asfrag *af6, *down6; 518 519 for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; 520 af6 = down6) { 521 struct mbuf *m = IP6_REASS_MBUF(af6); 522 523 down6 = af6->ip6af_down; 524 frag6_deq(af6); 525 526 /* 527 * Return ICMP time exceeded error for the 1st fragment. 528 * Just free other fragments. 529 */ 530 if (af6->ip6af_off == 0) { 531 struct ip6_hdr *ip6; 532 533 /* adjust pointer */ 534 ip6 = mtod(m, struct ip6_hdr *); 535 536 /* restoure source and destination addresses */ 537 ip6->ip6_src = q6->ip6q_src; 538 ip6->ip6_dst = q6->ip6q_dst; 539 540 icmp6_error(m, ICMP6_TIME_EXCEEDED, 541 ICMP6_TIME_EXCEED_REASSEMBLY, 0); 542 } else 543 m_freem(m); 544 kfree(af6, M_FTABLE); 545 } 546 frag6_remque(q6); 547 frag6_nfrags -= q6->ip6q_nfrag; 548 kfree(q6, M_FTABLE); 549 frag6_nfragpackets--; 550 } 551 552 /* 553 * Put an ip fragment on a reassembly chain. 554 * Like insque, but pointers in middle of structure. 555 */ 556 static void 557 frag6_enq(struct ip6asfrag *af6, struct ip6asfrag *up6) 558 { 559 af6->ip6af_up = up6; 560 af6->ip6af_down = up6->ip6af_down; 561 up6->ip6af_down->ip6af_up = af6; 562 up6->ip6af_down = af6; 563 } 564 565 /* 566 * To frag6_enq as remque is to insque. 567 */ 568 static void 569 frag6_deq(struct ip6asfrag *af6) 570 { 571 af6->ip6af_up->ip6af_down = af6->ip6af_down; 572 af6->ip6af_down->ip6af_up = af6->ip6af_up; 573 } 574 575 static void 576 frag6_insque(struct ip6q *new, struct ip6q *old) 577 { 578 new->ip6q_prev = old; 579 new->ip6q_next = old->ip6q_next; 580 old->ip6q_next->ip6q_prev= new; 581 old->ip6q_next = new; 582 } 583 584 static void 585 frag6_remque(struct ip6q *p6) 586 { 587 p6->ip6q_prev->ip6q_next = p6->ip6q_next; 588 p6->ip6q_next->ip6q_prev = p6->ip6q_prev; 589 } 590 591 /* 592 * IPv6 reassembling timer processing; 593 * if a timer expires on a reassembly 594 * queue, discard it. 595 */ 596 void 597 frag6_slowtimo(void) 598 { 599 struct ip6q *q6; 600 601 crit_enter(); 602 frag6_doing_reass = 1; 603 q6 = ip6q.ip6q_next; 604 if (q6) 605 while (q6 != &ip6q) { 606 --q6->ip6q_ttl; 607 q6 = q6->ip6q_next; 608 if (q6->ip6q_prev->ip6q_ttl == 0) { 609 ip6stat.ip6s_fragtimeout++; 610 /* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */ 611 frag6_freef(q6->ip6q_prev); 612 } 613 } 614 /* 615 * If we are over the maximum number of fragments 616 * (due to the limit being lowered), drain off 617 * enough to get down to the new limit. 618 */ 619 while (frag6_nfragpackets > (u_int)ip6_maxfragpackets && 620 ip6q.ip6q_prev) { 621 ip6stat.ip6s_fragoverflow++; 622 /* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */ 623 frag6_freef(ip6q.ip6q_prev); 624 } 625 frag6_doing_reass = 0; 626 627 #if 0 628 /* 629 * Routing changes might produce a better route than we last used; 630 * make sure we notice eventually, even if forwarding only for one 631 * destination and the cache is never replaced. 632 */ 633 if (ip6_forward_rt.ro_rt) { 634 RTFREE(ip6_forward_rt.ro_rt); 635 ip6_forward_rt.ro_rt = NULL; 636 } 637 if (ipsrcchk_rt.ro_rt) { 638 RTFREE(ipsrcchk_rt.ro_rt); 639 ipsrcchk_rt.ro_rt = NULL; 640 } 641 #endif 642 643 crit_exit(); 644 } 645 646 /* 647 * Drain off all datagram fragments. 648 */ 649 void 650 frag6_drain(void) 651 { 652 if (frag6_doing_reass) 653 return; 654 while (ip6q.ip6q_next != &ip6q) { 655 ip6stat.ip6s_fragdropped++; 656 /* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */ 657 frag6_freef(ip6q.ip6q_next); 658 } 659 } 660