1 /*- 2 * Copyright (c) 2015 Gleb Smirnoff <glebius@FreeBSD.org> 3 * Copyright (c) 2015 Adrian Chadd <adrian@FreeBSD.org> 4 * Copyright (c) 1982, 1986, 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_rss.h" 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/eventhandler.h> 42 #include <sys/hash.h> 43 #include <sys/mbuf.h> 44 #include <sys/malloc.h> 45 #include <sys/lock.h> 46 #include <sys/mutex.h> 47 #include <sys/sysctl.h> 48 49 #include <net/rss_config.h> 50 #include <net/netisr.h> 51 #include <net/vnet.h> 52 53 #include <netinet/in.h> 54 #include <netinet/ip.h> 55 #include <netinet/ip_var.h> 56 #include <netinet/in_rss.h> 57 #ifdef MAC 58 #include <security/mac/mac_framework.h> 59 #endif 60 61 SYSCTL_DECL(_net_inet_ip); 62 63 /* 64 * Reassembly headers are stored in hash buckets. 65 */ 66 #define IPREASS_NHASH_LOG2 6 67 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2) 68 #define IPREASS_HMASK (IPREASS_NHASH - 1) 69 70 struct ipqbucket { 71 TAILQ_HEAD(ipqhead, ipq) head; 72 struct mtx lock; 73 }; 74 75 static VNET_DEFINE(struct ipqbucket, ipq[IPREASS_NHASH]); 76 #define V_ipq VNET(ipq) 77 static VNET_DEFINE(uint32_t, ipq_hashseed); 78 #define V_ipq_hashseed VNET(ipq_hashseed) 79 80 #define IPQ_LOCK(i) mtx_lock(&V_ipq[i].lock) 81 #define IPQ_TRYLOCK(i) mtx_trylock(&V_ipq[i].lock) 82 #define IPQ_UNLOCK(i) mtx_unlock(&V_ipq[i].lock) 83 #define IPQ_LOCK_ASSERT(i) mtx_assert(&V_ipq[i].lock, MA_OWNED) 84 85 void ipreass_init(void); 86 void ipreass_drain(void); 87 void ipreass_slowtimo(void); 88 #ifdef VIMAGE 89 void ipreass_destroy(void); 90 #endif 91 static int sysctl_maxfragpackets(SYSCTL_HANDLER_ARGS); 92 static void ipreass_zone_change(void *); 93 static void ipreass_drain_tomax(void); 94 static void ipq_free(struct ipqhead *, struct ipq *); 95 static struct ipq * ipq_reuse(int); 96 97 static inline void 98 ipq_timeout(struct ipqhead *head, struct ipq *fp) 99 { 100 101 IPSTAT_ADD(ips_fragtimeout, fp->ipq_nfrags); 102 ipq_free(head, fp); 103 } 104 105 static inline void 106 ipq_drop(struct ipqhead *head, struct ipq *fp) 107 { 108 109 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags); 110 ipq_free(head, fp); 111 } 112 113 static VNET_DEFINE(uma_zone_t, ipq_zone); 114 #define V_ipq_zone VNET(ipq_zone) 115 SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_VNET | 116 CTLTYPE_INT | CTLFLAG_RW, NULL, 0, sysctl_maxfragpackets, "I", 117 "Maximum number of IPv4 fragment reassembly queue entries"); 118 SYSCTL_UMA_CUR(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_VNET, 119 &VNET_NAME(ipq_zone), 120 "Current number of IPv4 fragment reassembly queue entries"); 121 122 static VNET_DEFINE(int, noreass); 123 #define V_noreass VNET(noreass) 124 125 static VNET_DEFINE(int, maxfragsperpacket); 126 #define V_maxfragsperpacket VNET(maxfragsperpacket) 127 SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_VNET | CTLFLAG_RW, 128 &VNET_NAME(maxfragsperpacket), 0, 129 "Maximum number of IPv4 fragments allowed per packet"); 130 131 /* 132 * Take incoming datagram fragment and try to reassemble it into 133 * whole datagram. If the argument is the first fragment or one 134 * in between the function will return NULL and store the mbuf 135 * in the fragment chain. If the argument is the last fragment 136 * the packet will be reassembled and the pointer to the new 137 * mbuf returned for further processing. Only m_tags attached 138 * to the first packet/fragment are preserved. 139 * The IP header is *NOT* adjusted out of iplen. 140 */ 141 #define M_IP_FRAG M_PROTO9 142 struct mbuf * 143 ip_reass(struct mbuf *m) 144 { 145 struct ip *ip; 146 struct mbuf *p, *q, *nq, *t; 147 struct ipq *fp; 148 struct ipqhead *head; 149 int i, hlen, next; 150 u_int8_t ecn, ecn0; 151 uint32_t hash; 152 #ifdef RSS 153 uint32_t rss_hash, rss_type; 154 #endif 155 156 /* 157 * If no reassembling or maxfragsperpacket are 0, 158 * never accept fragments. 159 */ 160 if (V_noreass == 1 || V_maxfragsperpacket == 0) { 161 IPSTAT_INC(ips_fragments); 162 IPSTAT_INC(ips_fragdropped); 163 m_freem(m); 164 return (NULL); 165 } 166 167 ip = mtod(m, struct ip *); 168 hlen = ip->ip_hl << 2; 169 170 /* 171 * Adjust ip_len to not reflect header, 172 * convert offset of this to bytes. 173 */ 174 ip->ip_len = htons(ntohs(ip->ip_len) - hlen); 175 if (ip->ip_off & htons(IP_MF)) { 176 /* 177 * Make sure that fragments have a data length 178 * that's a non-zero multiple of 8 bytes. 179 */ 180 if (ip->ip_len == htons(0) || (ntohs(ip->ip_len) & 0x7) != 0) { 181 IPSTAT_INC(ips_toosmall); /* XXX */ 182 IPSTAT_INC(ips_fragdropped); 183 m_freem(m); 184 return (NULL); 185 } 186 m->m_flags |= M_IP_FRAG; 187 } else 188 m->m_flags &= ~M_IP_FRAG; 189 ip->ip_off = htons(ntohs(ip->ip_off) << 3); 190 191 /* 192 * Attempt reassembly; if it succeeds, proceed. 193 * ip_reass() will return a different mbuf. 194 */ 195 IPSTAT_INC(ips_fragments); 196 m->m_pkthdr.PH_loc.ptr = ip; 197 198 /* 199 * Presence of header sizes in mbufs 200 * would confuse code below. 201 */ 202 m->m_data += hlen; 203 m->m_len -= hlen; 204 205 hash = ip->ip_src.s_addr ^ ip->ip_id; 206 hash = jenkins_hash32(&hash, 1, V_ipq_hashseed) & IPREASS_HMASK; 207 head = &V_ipq[hash].head; 208 IPQ_LOCK(hash); 209 210 /* 211 * Look for queue of fragments 212 * of this datagram. 213 */ 214 TAILQ_FOREACH(fp, head, ipq_list) 215 if (ip->ip_id == fp->ipq_id && 216 ip->ip_src.s_addr == fp->ipq_src.s_addr && 217 ip->ip_dst.s_addr == fp->ipq_dst.s_addr && 218 #ifdef MAC 219 mac_ipq_match(m, fp) && 220 #endif 221 ip->ip_p == fp->ipq_p) 222 break; 223 /* 224 * If first fragment to arrive, create a reassembly queue. 225 */ 226 if (fp == NULL) { 227 fp = uma_zalloc(V_ipq_zone, M_NOWAIT); 228 if (fp == NULL) 229 fp = ipq_reuse(hash); 230 #ifdef MAC 231 if (mac_ipq_init(fp, M_NOWAIT) != 0) { 232 uma_zfree(V_ipq_zone, fp); 233 fp = NULL; 234 goto dropfrag; 235 } 236 mac_ipq_create(m, fp); 237 #endif 238 TAILQ_INSERT_HEAD(head, fp, ipq_list); 239 fp->ipq_nfrags = 1; 240 fp->ipq_ttl = IPFRAGTTL; 241 fp->ipq_p = ip->ip_p; 242 fp->ipq_id = ip->ip_id; 243 fp->ipq_src = ip->ip_src; 244 fp->ipq_dst = ip->ip_dst; 245 fp->ipq_frags = m; 246 m->m_nextpkt = NULL; 247 goto done; 248 } else { 249 fp->ipq_nfrags++; 250 #ifdef MAC 251 mac_ipq_update(m, fp); 252 #endif 253 } 254 255 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.PH_loc.ptr)) 256 257 /* 258 * Handle ECN by comparing this segment with the first one; 259 * if CE is set, do not lose CE. 260 * drop if CE and not-ECT are mixed for the same packet. 261 */ 262 ecn = ip->ip_tos & IPTOS_ECN_MASK; 263 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK; 264 if (ecn == IPTOS_ECN_CE) { 265 if (ecn0 == IPTOS_ECN_NOTECT) 266 goto dropfrag; 267 if (ecn0 != IPTOS_ECN_CE) 268 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE; 269 } 270 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT) 271 goto dropfrag; 272 273 /* 274 * Find a segment which begins after this one does. 275 */ 276 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) 277 if (ntohs(GETIP(q)->ip_off) > ntohs(ip->ip_off)) 278 break; 279 280 /* 281 * If there is a preceding segment, it may provide some of 282 * our data already. If so, drop the data from the incoming 283 * segment. If it provides all of our data, drop us, otherwise 284 * stick new segment in the proper place. 285 * 286 * If some of the data is dropped from the preceding 287 * segment, then it's checksum is invalidated. 288 */ 289 if (p) { 290 i = ntohs(GETIP(p)->ip_off) + ntohs(GETIP(p)->ip_len) - 291 ntohs(ip->ip_off); 292 if (i > 0) { 293 if (i >= ntohs(ip->ip_len)) 294 goto dropfrag; 295 m_adj(m, i); 296 m->m_pkthdr.csum_flags = 0; 297 ip->ip_off = htons(ntohs(ip->ip_off) + i); 298 ip->ip_len = htons(ntohs(ip->ip_len) - i); 299 } 300 m->m_nextpkt = p->m_nextpkt; 301 p->m_nextpkt = m; 302 } else { 303 m->m_nextpkt = fp->ipq_frags; 304 fp->ipq_frags = m; 305 } 306 307 /* 308 * While we overlap succeeding segments trim them or, 309 * if they are completely covered, dequeue them. 310 */ 311 for (; q != NULL && ntohs(ip->ip_off) + ntohs(ip->ip_len) > 312 ntohs(GETIP(q)->ip_off); q = nq) { 313 i = (ntohs(ip->ip_off) + ntohs(ip->ip_len)) - 314 ntohs(GETIP(q)->ip_off); 315 if (i < ntohs(GETIP(q)->ip_len)) { 316 GETIP(q)->ip_len = htons(ntohs(GETIP(q)->ip_len) - i); 317 GETIP(q)->ip_off = htons(ntohs(GETIP(q)->ip_off) + i); 318 m_adj(q, i); 319 q->m_pkthdr.csum_flags = 0; 320 break; 321 } 322 nq = q->m_nextpkt; 323 m->m_nextpkt = nq; 324 IPSTAT_INC(ips_fragdropped); 325 fp->ipq_nfrags--; 326 m_freem(q); 327 } 328 329 /* 330 * Check for complete reassembly and perform frag per packet 331 * limiting. 332 * 333 * Frag limiting is performed here so that the nth frag has 334 * a chance to complete the packet before we drop the packet. 335 * As a result, n+1 frags are actually allowed per packet, but 336 * only n will ever be stored. (n = maxfragsperpacket.) 337 * 338 */ 339 next = 0; 340 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) { 341 if (ntohs(GETIP(q)->ip_off) != next) { 342 if (fp->ipq_nfrags > V_maxfragsperpacket) 343 ipq_drop(head, fp); 344 goto done; 345 } 346 next += ntohs(GETIP(q)->ip_len); 347 } 348 /* Make sure the last packet didn't have the IP_MF flag */ 349 if (p->m_flags & M_IP_FRAG) { 350 if (fp->ipq_nfrags > V_maxfragsperpacket) 351 ipq_drop(head, fp); 352 goto done; 353 } 354 355 /* 356 * Reassembly is complete. Make sure the packet is a sane size. 357 */ 358 q = fp->ipq_frags; 359 ip = GETIP(q); 360 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) { 361 IPSTAT_INC(ips_toolong); 362 ipq_drop(head, fp); 363 goto done; 364 } 365 366 /* 367 * Concatenate fragments. 368 */ 369 m = q; 370 t = m->m_next; 371 m->m_next = NULL; 372 m_cat(m, t); 373 nq = q->m_nextpkt; 374 q->m_nextpkt = NULL; 375 for (q = nq; q != NULL; q = nq) { 376 nq = q->m_nextpkt; 377 q->m_nextpkt = NULL; 378 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags; 379 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data; 380 m_cat(m, q); 381 } 382 /* 383 * In order to do checksumming faster we do 'end-around carry' here 384 * (and not in for{} loop), though it implies we are not going to 385 * reassemble more than 64k fragments. 386 */ 387 while (m->m_pkthdr.csum_data & 0xffff0000) 388 m->m_pkthdr.csum_data = (m->m_pkthdr.csum_data & 0xffff) + 389 (m->m_pkthdr.csum_data >> 16); 390 #ifdef MAC 391 mac_ipq_reassemble(fp, m); 392 mac_ipq_destroy(fp); 393 #endif 394 395 /* 396 * Create header for new ip packet by modifying header of first 397 * packet; dequeue and discard fragment reassembly header. 398 * Make header visible. 399 */ 400 ip->ip_len = htons((ip->ip_hl << 2) + next); 401 ip->ip_src = fp->ipq_src; 402 ip->ip_dst = fp->ipq_dst; 403 TAILQ_REMOVE(head, fp, ipq_list); 404 uma_zfree(V_ipq_zone, fp); 405 m->m_len += (ip->ip_hl << 2); 406 m->m_data -= (ip->ip_hl << 2); 407 /* some debugging cruft by sklower, below, will go away soon */ 408 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */ 409 m_fixhdr(m); 410 IPSTAT_INC(ips_reassembled); 411 IPQ_UNLOCK(hash); 412 413 #ifdef RSS 414 /* 415 * Query the RSS layer for the flowid / flowtype for the 416 * mbuf payload. 417 * 418 * For now, just assume we have to calculate a new one. 419 * Later on we should check to see if the assigned flowid matches 420 * what RSS wants for the given IP protocol and if so, just keep it. 421 * 422 * We then queue into the relevant netisr so it can be dispatched 423 * to the correct CPU. 424 * 425 * Note - this may return 1, which means the flowid in the mbuf 426 * is correct for the configured RSS hash types and can be used. 427 */ 428 if (rss_mbuf_software_hash_v4(m, 0, &rss_hash, &rss_type) == 0) { 429 m->m_pkthdr.flowid = rss_hash; 430 M_HASHTYPE_SET(m, rss_type); 431 } 432 433 /* 434 * Queue/dispatch for reprocessing. 435 * 436 * Note: this is much slower than just handling the frame in the 437 * current receive context. It's likely worth investigating 438 * why this is. 439 */ 440 netisr_dispatch(NETISR_IP_DIRECT, m); 441 return (NULL); 442 #endif 443 444 /* Handle in-line */ 445 return (m); 446 447 dropfrag: 448 IPSTAT_INC(ips_fragdropped); 449 if (fp != NULL) 450 fp->ipq_nfrags--; 451 m_freem(m); 452 done: 453 IPQ_UNLOCK(hash); 454 return (NULL); 455 456 #undef GETIP 457 } 458 459 /* 460 * Initialize IP reassembly structures. 461 */ 462 void 463 ipreass_init(void) 464 { 465 466 for (int i = 0; i < IPREASS_NHASH; i++) { 467 TAILQ_INIT(&V_ipq[i].head); 468 mtx_init(&V_ipq[i].lock, "IP reassembly", NULL, 469 MTX_DEF | MTX_DUPOK); 470 } 471 V_ipq_hashseed = arc4random(); 472 V_maxfragsperpacket = 16; 473 V_ipq_zone = uma_zcreate("ipq", sizeof(struct ipq), NULL, NULL, NULL, 474 NULL, UMA_ALIGN_PTR, 0); 475 uma_zone_set_max(V_ipq_zone, nmbclusters / 32); 476 477 if (IS_DEFAULT_VNET(curvnet)) 478 EVENTHANDLER_REGISTER(nmbclusters_change, ipreass_zone_change, 479 NULL, EVENTHANDLER_PRI_ANY); 480 } 481 482 /* 483 * If a timer expires on a reassembly queue, discard it. 484 */ 485 void 486 ipreass_slowtimo(void) 487 { 488 struct ipq *fp, *tmp; 489 490 for (int i = 0; i < IPREASS_NHASH; i++) { 491 IPQ_LOCK(i); 492 TAILQ_FOREACH_SAFE(fp, &V_ipq[i].head, ipq_list, tmp) 493 if (--fp->ipq_ttl == 0) 494 ipq_timeout(&V_ipq[i].head, fp); 495 IPQ_UNLOCK(i); 496 } 497 } 498 499 /* 500 * Drain off all datagram fragments. 501 */ 502 void 503 ipreass_drain(void) 504 { 505 506 for (int i = 0; i < IPREASS_NHASH; i++) { 507 IPQ_LOCK(i); 508 while(!TAILQ_EMPTY(&V_ipq[i].head)) 509 ipq_drop(&V_ipq[i].head, TAILQ_FIRST(&V_ipq[i].head)); 510 IPQ_UNLOCK(i); 511 } 512 } 513 514 #ifdef VIMAGE 515 /* 516 * Destroy IP reassembly structures. 517 */ 518 void 519 ipreass_destroy(void) 520 { 521 522 ipreass_drain(); 523 uma_zdestroy(V_ipq_zone); 524 for (int i = 0; i < IPREASS_NHASH; i++) 525 mtx_destroy(&V_ipq[i].lock); 526 } 527 #endif 528 529 /* 530 * After maxnipq has been updated, propagate the change to UMA. The UMA zone 531 * max has slightly different semantics than the sysctl, for historical 532 * reasons. 533 */ 534 static void 535 ipreass_drain_tomax(void) 536 { 537 int target; 538 539 /* 540 * If we are over the maximum number of fragments, 541 * drain off enough to get down to the new limit, 542 * stripping off last elements on queues. Every 543 * run we strip the oldest element from each bucket. 544 */ 545 target = uma_zone_get_max(V_ipq_zone); 546 while (uma_zone_get_cur(V_ipq_zone) > target) { 547 struct ipq *fp; 548 549 for (int i = 0; i < IPREASS_NHASH; i++) { 550 IPQ_LOCK(i); 551 fp = TAILQ_LAST(&V_ipq[i].head, ipqhead); 552 if (fp != NULL) 553 ipq_timeout(&V_ipq[i].head, fp); 554 IPQ_UNLOCK(i); 555 } 556 } 557 } 558 559 static void 560 ipreass_zone_change(void *tag) 561 { 562 563 uma_zone_set_max(V_ipq_zone, nmbclusters / 32); 564 ipreass_drain_tomax(); 565 } 566 567 /* 568 * Change the limit on the UMA zone, or disable the fragment allocation 569 * at all. Since 0 and -1 is a special values here, we need our own handler, 570 * instead of sysctl_handle_uma_zone_max(). 571 */ 572 static int 573 sysctl_maxfragpackets(SYSCTL_HANDLER_ARGS) 574 { 575 int error, max; 576 577 if (V_noreass == 0) { 578 max = uma_zone_get_max(V_ipq_zone); 579 if (max == 0) 580 max = -1; 581 } else 582 max = 0; 583 error = sysctl_handle_int(oidp, &max, 0, req); 584 if (error || !req->newptr) 585 return (error); 586 if (max > 0) { 587 /* 588 * XXXRW: Might be a good idea to sanity check the argument 589 * and place an extreme upper bound. 590 */ 591 max = uma_zone_set_max(V_ipq_zone, max); 592 ipreass_drain_tomax(); 593 V_noreass = 0; 594 } else if (max == 0) { 595 V_noreass = 1; 596 ipreass_drain(); 597 } else if (max == -1) { 598 V_noreass = 0; 599 uma_zone_set_max(V_ipq_zone, 0); 600 } else 601 return (EINVAL); 602 return (0); 603 } 604 605 /* 606 * Seek for old fragment queue header that can be reused. Try to 607 * reuse a header from currently locked hash bucket. 608 */ 609 static struct ipq * 610 ipq_reuse(int start) 611 { 612 struct ipq *fp; 613 int i; 614 615 IPQ_LOCK_ASSERT(start); 616 617 for (i = start;; i++) { 618 if (i == IPREASS_NHASH) 619 i = 0; 620 if (i != start && IPQ_TRYLOCK(i) == 0) 621 continue; 622 fp = TAILQ_LAST(&V_ipq[i].head, ipqhead); 623 if (fp) { 624 struct mbuf *m; 625 626 IPSTAT_ADD(ips_fragtimeout, fp->ipq_nfrags); 627 while (fp->ipq_frags) { 628 m = fp->ipq_frags; 629 fp->ipq_frags = m->m_nextpkt; 630 m_freem(m); 631 } 632 TAILQ_REMOVE(&V_ipq[i].head, fp, ipq_list); 633 if (i != start) 634 IPQ_UNLOCK(i); 635 IPQ_LOCK_ASSERT(start); 636 return (fp); 637 } 638 if (i != start) 639 IPQ_UNLOCK(i); 640 } 641 } 642 643 /* 644 * Free a fragment reassembly header and all associated datagrams. 645 */ 646 static void 647 ipq_free(struct ipqhead *fhp, struct ipq *fp) 648 { 649 struct mbuf *q; 650 651 while (fp->ipq_frags) { 652 q = fp->ipq_frags; 653 fp->ipq_frags = q->m_nextpkt; 654 m_freem(q); 655 } 656 TAILQ_REMOVE(fhp, fp, ipq_list); 657 uma_zfree(V_ipq_zone, fp); 658 } 659