1 /* 2 * IPv6 fragment reassembly 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * Based on: net/ipv4/ip_fragment.c 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 /* 17 * Fixes: 18 * Andi Kleen Make it work with multiple hosts. 19 * More RFC compliance. 20 * 21 * Horst von Brand Add missing #include <linux/string.h> 22 * Alexey Kuznetsov SMP races, threading, cleanup. 23 * Patrick McHardy LRU queue of frag heads for evictor. 24 * Mitsuru KANDA @USAGI Register inet6_protocol{}. 25 * David Stevens and 26 * YOSHIFUJI,H. @USAGI Always remove fragment header to 27 * calculate ICV correctly. 28 */ 29 30 #define pr_fmt(fmt) "IPv6: " fmt 31 32 #include <linux/errno.h> 33 #include <linux/types.h> 34 #include <linux/string.h> 35 #include <linux/socket.h> 36 #include <linux/sockios.h> 37 #include <linux/jiffies.h> 38 #include <linux/net.h> 39 #include <linux/list.h> 40 #include <linux/netdevice.h> 41 #include <linux/in6.h> 42 #include <linux/ipv6.h> 43 #include <linux/icmpv6.h> 44 #include <linux/random.h> 45 #include <linux/jhash.h> 46 #include <linux/skbuff.h> 47 #include <linux/slab.h> 48 #include <linux/export.h> 49 50 #include <net/sock.h> 51 #include <net/snmp.h> 52 53 #include <net/ipv6.h> 54 #include <net/ip6_route.h> 55 #include <net/protocol.h> 56 #include <net/transp_v6.h> 57 #include <net/rawv6.h> 58 #include <net/ndisc.h> 59 #include <net/addrconf.h> 60 #include <net/inet_frag.h> 61 #include <net/inet_ecn.h> 62 63 static const char ip6_frag_cache_name[] = "ip6-frags"; 64 65 static u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h) 66 { 67 return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK); 68 } 69 70 static struct inet_frags ip6_frags; 71 72 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 73 struct net_device *dev); 74 75 void ip6_frag_init(struct inet_frag_queue *q, const void *a) 76 { 77 struct frag_queue *fq = container_of(q, struct frag_queue, q); 78 const struct frag_v6_compare_key *key = a; 79 80 q->key.v6 = *key; 81 fq->ecn = 0; 82 } 83 EXPORT_SYMBOL(ip6_frag_init); 84 85 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq) 86 { 87 struct net_device *dev = NULL; 88 struct sk_buff *head; 89 90 rcu_read_lock(); 91 spin_lock(&fq->q.lock); 92 93 if (fq->q.flags & INET_FRAG_COMPLETE) 94 goto out; 95 96 inet_frag_kill(&fq->q); 97 98 dev = dev_get_by_index_rcu(net, fq->iif); 99 if (!dev) 100 goto out; 101 102 __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 103 __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); 104 105 /* Don't send error if the first segment did not arrive. */ 106 head = fq->q.fragments; 107 if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !head) 108 goto out; 109 110 /* But use as source device on which LAST ARRIVED 111 * segment was received. And do not use fq->dev 112 * pointer directly, device might already disappeared. 113 */ 114 head->dev = dev; 115 skb_get(head); 116 spin_unlock(&fq->q.lock); 117 118 icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); 119 kfree_skb(head); 120 goto out_rcu_unlock; 121 122 out: 123 spin_unlock(&fq->q.lock); 124 out_rcu_unlock: 125 rcu_read_unlock(); 126 inet_frag_put(&fq->q); 127 } 128 EXPORT_SYMBOL(ip6_expire_frag_queue); 129 130 static void ip6_frag_expire(struct timer_list *t) 131 { 132 struct inet_frag_queue *frag = from_timer(frag, t, timer); 133 struct frag_queue *fq; 134 struct net *net; 135 136 fq = container_of(frag, struct frag_queue, q); 137 net = container_of(fq->q.net, struct net, ipv6.frags); 138 139 ip6_expire_frag_queue(net, fq); 140 } 141 142 static struct frag_queue * 143 fq_find(struct net *net, __be32 id, const struct ipv6hdr *hdr, int iif) 144 { 145 struct frag_v6_compare_key key = { 146 .id = id, 147 .saddr = hdr->saddr, 148 .daddr = hdr->daddr, 149 .user = IP6_DEFRAG_LOCAL_DELIVER, 150 .iif = iif, 151 }; 152 struct inet_frag_queue *q; 153 154 if (!(ipv6_addr_type(&hdr->daddr) & (IPV6_ADDR_MULTICAST | 155 IPV6_ADDR_LINKLOCAL))) 156 key.iif = 0; 157 158 q = inet_frag_find(&net->ipv6.frags, &key); 159 if (!q) 160 return NULL; 161 162 return container_of(q, struct frag_queue, q); 163 } 164 165 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, 166 struct frag_hdr *fhdr, int nhoff) 167 { 168 struct sk_buff *prev, *next; 169 struct net_device *dev; 170 int offset, end, fragsize; 171 struct net *net = dev_net(skb_dst(skb)->dev); 172 u8 ecn; 173 174 if (fq->q.flags & INET_FRAG_COMPLETE) 175 goto err; 176 177 offset = ntohs(fhdr->frag_off) & ~0x7; 178 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - 179 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); 180 181 if ((unsigned int)end > IPV6_MAXPLEN) { 182 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 183 IPSTATS_MIB_INHDRERRORS); 184 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 185 ((u8 *)&fhdr->frag_off - 186 skb_network_header(skb))); 187 return -1; 188 } 189 190 ecn = ip6_frag_ecn(ipv6_hdr(skb)); 191 192 if (skb->ip_summed == CHECKSUM_COMPLETE) { 193 const unsigned char *nh = skb_network_header(skb); 194 skb->csum = csum_sub(skb->csum, 195 csum_partial(nh, (u8 *)(fhdr + 1) - nh, 196 0)); 197 } 198 199 /* Is this the final fragment? */ 200 if (!(fhdr->frag_off & htons(IP6_MF))) { 201 /* If we already have some bits beyond end 202 * or have different end, the segment is corrupted. 203 */ 204 if (end < fq->q.len || 205 ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len)) 206 goto err; 207 fq->q.flags |= INET_FRAG_LAST_IN; 208 fq->q.len = end; 209 } else { 210 /* Check if the fragment is rounded to 8 bytes. 211 * Required by the RFC. 212 */ 213 if (end & 0x7) { 214 /* RFC2460 says always send parameter problem in 215 * this case. -DaveM 216 */ 217 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 218 IPSTATS_MIB_INHDRERRORS); 219 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 220 offsetof(struct ipv6hdr, payload_len)); 221 return -1; 222 } 223 if (end > fq->q.len) { 224 /* Some bits beyond end -> corruption. */ 225 if (fq->q.flags & INET_FRAG_LAST_IN) 226 goto err; 227 fq->q.len = end; 228 } 229 } 230 231 if (end == offset) 232 goto err; 233 234 /* Point into the IP datagram 'data' part. */ 235 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) 236 goto err; 237 238 if (pskb_trim_rcsum(skb, end - offset)) 239 goto err; 240 241 /* Find out which fragments are in front and at the back of us 242 * in the chain of fragments so far. We must know where to put 243 * this fragment, right? 244 */ 245 prev = fq->q.fragments_tail; 246 if (!prev || prev->ip_defrag_offset < offset) { 247 next = NULL; 248 goto found; 249 } 250 prev = NULL; 251 for (next = fq->q.fragments; next != NULL; next = next->next) { 252 if (next->ip_defrag_offset >= offset) 253 break; /* bingo! */ 254 prev = next; 255 } 256 257 found: 258 /* RFC5722, Section 4, amended by Errata ID : 3089 259 * When reassembling an IPv6 datagram, if 260 * one or more its constituent fragments is determined to be an 261 * overlapping fragment, the entire datagram (and any constituent 262 * fragments) MUST be silently discarded. 263 */ 264 265 /* Check for overlap with preceding fragment. */ 266 if (prev && 267 (prev->ip_defrag_offset + prev->len) > offset) 268 goto discard_fq; 269 270 /* Look for overlap with succeeding segment. */ 271 if (next && next->ip_defrag_offset < end) 272 goto discard_fq; 273 274 /* Note : skb->ip_defrag_offset and skb->dev share the same location */ 275 dev = skb->dev; 276 if (dev) 277 fq->iif = dev->ifindex; 278 /* Makes sure compiler wont do silly aliasing games */ 279 barrier(); 280 skb->ip_defrag_offset = offset; 281 282 /* Insert this fragment in the chain of fragments. */ 283 skb->next = next; 284 if (!next) 285 fq->q.fragments_tail = skb; 286 if (prev) 287 prev->next = skb; 288 else 289 fq->q.fragments = skb; 290 291 fq->q.stamp = skb->tstamp; 292 fq->q.meat += skb->len; 293 fq->ecn |= ecn; 294 add_frag_mem_limit(fq->q.net, skb->truesize); 295 296 fragsize = -skb_network_offset(skb) + skb->len; 297 if (fragsize > fq->q.max_size) 298 fq->q.max_size = fragsize; 299 300 /* The first fragment. 301 * nhoffset is obtained from the first fragment, of course. 302 */ 303 if (offset == 0) { 304 fq->nhoffset = nhoff; 305 fq->q.flags |= INET_FRAG_FIRST_IN; 306 } 307 308 if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 309 fq->q.meat == fq->q.len) { 310 int res; 311 unsigned long orefdst = skb->_skb_refdst; 312 313 skb->_skb_refdst = 0UL; 314 res = ip6_frag_reasm(fq, prev, dev); 315 skb->_skb_refdst = orefdst; 316 return res; 317 } 318 319 skb_dst_drop(skb); 320 return -1; 321 322 discard_fq: 323 inet_frag_kill(&fq->q); 324 err: 325 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 326 IPSTATS_MIB_REASMFAILS); 327 kfree_skb(skb); 328 return -1; 329 } 330 331 /* 332 * Check if this packet is complete. 333 * Returns NULL on failure by any reason, and pointer 334 * to current nexthdr field in reassembled frame. 335 * 336 * It is called with locked fq, and caller must check that 337 * queue is eligible for reassembly i.e. it is not COMPLETE, 338 * the last and the first frames arrived and all the bits are here. 339 */ 340 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 341 struct net_device *dev) 342 { 343 struct net *net = container_of(fq->q.net, struct net, ipv6.frags); 344 struct sk_buff *fp, *head = fq->q.fragments; 345 int payload_len; 346 unsigned int nhoff; 347 int sum_truesize; 348 u8 ecn; 349 350 inet_frag_kill(&fq->q); 351 352 ecn = ip_frag_ecn_table[fq->ecn]; 353 if (unlikely(ecn == 0xff)) 354 goto out_fail; 355 356 /* Make the one we just received the head. */ 357 if (prev) { 358 head = prev->next; 359 fp = skb_clone(head, GFP_ATOMIC); 360 361 if (!fp) 362 goto out_oom; 363 364 fp->next = head->next; 365 if (!fp->next) 366 fq->q.fragments_tail = fp; 367 prev->next = fp; 368 369 skb_morph(head, fq->q.fragments); 370 head->next = fq->q.fragments->next; 371 372 consume_skb(fq->q.fragments); 373 fq->q.fragments = head; 374 } 375 376 WARN_ON(head == NULL); 377 WARN_ON(head->ip_defrag_offset != 0); 378 379 /* Unfragmented part is taken from the first segment. */ 380 payload_len = ((head->data - skb_network_header(head)) - 381 sizeof(struct ipv6hdr) + fq->q.len - 382 sizeof(struct frag_hdr)); 383 if (payload_len > IPV6_MAXPLEN) 384 goto out_oversize; 385 386 /* Head of list must not be cloned. */ 387 if (skb_unclone(head, GFP_ATOMIC)) 388 goto out_oom; 389 390 /* If the first fragment is fragmented itself, we split 391 * it to two chunks: the first with data and paged part 392 * and the second, holding only fragments. */ 393 if (skb_has_frag_list(head)) { 394 struct sk_buff *clone; 395 int i, plen = 0; 396 397 clone = alloc_skb(0, GFP_ATOMIC); 398 if (!clone) 399 goto out_oom; 400 clone->next = head->next; 401 head->next = clone; 402 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 403 skb_frag_list_init(head); 404 for (i = 0; i < skb_shinfo(head)->nr_frags; i++) 405 plen += skb_frag_size(&skb_shinfo(head)->frags[i]); 406 clone->len = clone->data_len = head->data_len - plen; 407 head->data_len -= clone->len; 408 head->len -= clone->len; 409 clone->csum = 0; 410 clone->ip_summed = head->ip_summed; 411 add_frag_mem_limit(fq->q.net, clone->truesize); 412 } 413 414 /* We have to remove fragment header from datagram and to relocate 415 * header in order to calculate ICV correctly. */ 416 nhoff = fq->nhoffset; 417 skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; 418 memmove(head->head + sizeof(struct frag_hdr), head->head, 419 (head->data - head->head) - sizeof(struct frag_hdr)); 420 if (skb_mac_header_was_set(head)) 421 head->mac_header += sizeof(struct frag_hdr); 422 head->network_header += sizeof(struct frag_hdr); 423 424 skb_reset_transport_header(head); 425 skb_push(head, head->data - skb_network_header(head)); 426 427 sum_truesize = head->truesize; 428 for (fp = head->next; fp;) { 429 bool headstolen; 430 int delta; 431 struct sk_buff *next = fp->next; 432 433 sum_truesize += fp->truesize; 434 if (head->ip_summed != fp->ip_summed) 435 head->ip_summed = CHECKSUM_NONE; 436 else if (head->ip_summed == CHECKSUM_COMPLETE) 437 head->csum = csum_add(head->csum, fp->csum); 438 439 if (skb_try_coalesce(head, fp, &headstolen, &delta)) { 440 kfree_skb_partial(fp, headstolen); 441 } else { 442 if (!skb_shinfo(head)->frag_list) 443 skb_shinfo(head)->frag_list = fp; 444 head->data_len += fp->len; 445 head->len += fp->len; 446 head->truesize += fp->truesize; 447 } 448 fp = next; 449 } 450 sub_frag_mem_limit(fq->q.net, sum_truesize); 451 452 head->next = NULL; 453 head->dev = dev; 454 head->tstamp = fq->q.stamp; 455 ipv6_hdr(head)->payload_len = htons(payload_len); 456 ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); 457 IP6CB(head)->nhoff = nhoff; 458 IP6CB(head)->flags |= IP6SKB_FRAGMENTED; 459 IP6CB(head)->frag_max_size = fq->q.max_size; 460 461 /* Yes, and fold redundant checksum back. 8) */ 462 skb_postpush_rcsum(head, skb_network_header(head), 463 skb_network_header_len(head)); 464 465 rcu_read_lock(); 466 __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); 467 rcu_read_unlock(); 468 fq->q.fragments = NULL; 469 fq->q.fragments_tail = NULL; 470 return 1; 471 472 out_oversize: 473 net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); 474 goto out_fail; 475 out_oom: 476 net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); 477 out_fail: 478 rcu_read_lock(); 479 __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 480 rcu_read_unlock(); 481 return -1; 482 } 483 484 static int ipv6_frag_rcv(struct sk_buff *skb) 485 { 486 struct frag_hdr *fhdr; 487 struct frag_queue *fq; 488 const struct ipv6hdr *hdr = ipv6_hdr(skb); 489 struct net *net = dev_net(skb_dst(skb)->dev); 490 int iif; 491 492 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED) 493 goto fail_hdr; 494 495 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); 496 497 /* Jumbo payload inhibits frag. header */ 498 if (hdr->payload_len == 0) 499 goto fail_hdr; 500 501 if (!pskb_may_pull(skb, (skb_transport_offset(skb) + 502 sizeof(struct frag_hdr)))) 503 goto fail_hdr; 504 505 hdr = ipv6_hdr(skb); 506 fhdr = (struct frag_hdr *)skb_transport_header(skb); 507 508 if (!(fhdr->frag_off & htons(0xFFF9))) { 509 /* It is not a fragmented frame */ 510 skb->transport_header += sizeof(struct frag_hdr); 511 __IP6_INC_STATS(net, 512 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); 513 514 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); 515 IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; 516 return 1; 517 } 518 519 iif = skb->dev ? skb->dev->ifindex : 0; 520 fq = fq_find(net, fhdr->identification, hdr, iif); 521 if (fq) { 522 int ret; 523 524 spin_lock(&fq->q.lock); 525 526 fq->iif = iif; 527 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); 528 529 spin_unlock(&fq->q.lock); 530 inet_frag_put(&fq->q); 531 return ret; 532 } 533 534 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); 535 kfree_skb(skb); 536 return -1; 537 538 fail_hdr: 539 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 540 IPSTATS_MIB_INHDRERRORS); 541 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); 542 return -1; 543 } 544 545 static const struct inet6_protocol frag_protocol = { 546 .handler = ipv6_frag_rcv, 547 .flags = INET6_PROTO_NOPOLICY, 548 }; 549 550 #ifdef CONFIG_SYSCTL 551 552 static struct ctl_table ip6_frags_ns_ctl_table[] = { 553 { 554 .procname = "ip6frag_high_thresh", 555 .data = &init_net.ipv6.frags.high_thresh, 556 .maxlen = sizeof(unsigned long), 557 .mode = 0644, 558 .proc_handler = proc_doulongvec_minmax, 559 .extra1 = &init_net.ipv6.frags.low_thresh 560 }, 561 { 562 .procname = "ip6frag_low_thresh", 563 .data = &init_net.ipv6.frags.low_thresh, 564 .maxlen = sizeof(unsigned long), 565 .mode = 0644, 566 .proc_handler = proc_doulongvec_minmax, 567 .extra2 = &init_net.ipv6.frags.high_thresh 568 }, 569 { 570 .procname = "ip6frag_time", 571 .data = &init_net.ipv6.frags.timeout, 572 .maxlen = sizeof(int), 573 .mode = 0644, 574 .proc_handler = proc_dointvec_jiffies, 575 }, 576 { } 577 }; 578 579 /* secret interval has been deprecated */ 580 static int ip6_frags_secret_interval_unused; 581 static struct ctl_table ip6_frags_ctl_table[] = { 582 { 583 .procname = "ip6frag_secret_interval", 584 .data = &ip6_frags_secret_interval_unused, 585 .maxlen = sizeof(int), 586 .mode = 0644, 587 .proc_handler = proc_dointvec_jiffies, 588 }, 589 { } 590 }; 591 592 static int __net_init ip6_frags_ns_sysctl_register(struct net *net) 593 { 594 struct ctl_table *table; 595 struct ctl_table_header *hdr; 596 597 table = ip6_frags_ns_ctl_table; 598 if (!net_eq(net, &init_net)) { 599 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); 600 if (!table) 601 goto err_alloc; 602 603 table[0].data = &net->ipv6.frags.high_thresh; 604 table[0].extra1 = &net->ipv6.frags.low_thresh; 605 table[0].extra2 = &init_net.ipv6.frags.high_thresh; 606 table[1].data = &net->ipv6.frags.low_thresh; 607 table[1].extra2 = &net->ipv6.frags.high_thresh; 608 table[2].data = &net->ipv6.frags.timeout; 609 } 610 611 hdr = register_net_sysctl(net, "net/ipv6", table); 612 if (!hdr) 613 goto err_reg; 614 615 net->ipv6.sysctl.frags_hdr = hdr; 616 return 0; 617 618 err_reg: 619 if (!net_eq(net, &init_net)) 620 kfree(table); 621 err_alloc: 622 return -ENOMEM; 623 } 624 625 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) 626 { 627 struct ctl_table *table; 628 629 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; 630 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); 631 if (!net_eq(net, &init_net)) 632 kfree(table); 633 } 634 635 static struct ctl_table_header *ip6_ctl_header; 636 637 static int ip6_frags_sysctl_register(void) 638 { 639 ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", 640 ip6_frags_ctl_table); 641 return ip6_ctl_header == NULL ? -ENOMEM : 0; 642 } 643 644 static void ip6_frags_sysctl_unregister(void) 645 { 646 unregister_net_sysctl_table(ip6_ctl_header); 647 } 648 #else 649 static int ip6_frags_ns_sysctl_register(struct net *net) 650 { 651 return 0; 652 } 653 654 static void ip6_frags_ns_sysctl_unregister(struct net *net) 655 { 656 } 657 658 static int ip6_frags_sysctl_register(void) 659 { 660 return 0; 661 } 662 663 static void ip6_frags_sysctl_unregister(void) 664 { 665 } 666 #endif 667 668 static int __net_init ipv6_frags_init_net(struct net *net) 669 { 670 int res; 671 672 net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; 673 net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; 674 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; 675 net->ipv6.frags.f = &ip6_frags; 676 677 res = inet_frags_init_net(&net->ipv6.frags); 678 if (res < 0) 679 return res; 680 681 res = ip6_frags_ns_sysctl_register(net); 682 if (res < 0) 683 inet_frags_exit_net(&net->ipv6.frags); 684 return res; 685 } 686 687 static void __net_exit ipv6_frags_exit_net(struct net *net) 688 { 689 ip6_frags_ns_sysctl_unregister(net); 690 inet_frags_exit_net(&net->ipv6.frags); 691 } 692 693 static struct pernet_operations ip6_frags_ops = { 694 .init = ipv6_frags_init_net, 695 .exit = ipv6_frags_exit_net, 696 }; 697 698 static u32 ip6_key_hashfn(const void *data, u32 len, u32 seed) 699 { 700 return jhash2(data, 701 sizeof(struct frag_v6_compare_key) / sizeof(u32), seed); 702 } 703 704 static u32 ip6_obj_hashfn(const void *data, u32 len, u32 seed) 705 { 706 const struct inet_frag_queue *fq = data; 707 708 return jhash2((const u32 *)&fq->key.v6, 709 sizeof(struct frag_v6_compare_key) / sizeof(u32), seed); 710 } 711 712 static int ip6_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr) 713 { 714 const struct frag_v6_compare_key *key = arg->key; 715 const struct inet_frag_queue *fq = ptr; 716 717 return !!memcmp(&fq->key, key, sizeof(*key)); 718 } 719 720 const struct rhashtable_params ip6_rhash_params = { 721 .head_offset = offsetof(struct inet_frag_queue, node), 722 .hashfn = ip6_key_hashfn, 723 .obj_hashfn = ip6_obj_hashfn, 724 .obj_cmpfn = ip6_obj_cmpfn, 725 .automatic_shrinking = true, 726 }; 727 EXPORT_SYMBOL(ip6_rhash_params); 728 729 int __init ipv6_frag_init(void) 730 { 731 int ret; 732 733 ip6_frags.constructor = ip6_frag_init; 734 ip6_frags.destructor = NULL; 735 ip6_frags.qsize = sizeof(struct frag_queue); 736 ip6_frags.frag_expire = ip6_frag_expire; 737 ip6_frags.frags_cache_name = ip6_frag_cache_name; 738 ip6_frags.rhash_params = ip6_rhash_params; 739 ret = inet_frags_init(&ip6_frags); 740 if (ret) 741 goto out; 742 743 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); 744 if (ret) 745 goto err_protocol; 746 747 ret = ip6_frags_sysctl_register(); 748 if (ret) 749 goto err_sysctl; 750 751 ret = register_pernet_subsys(&ip6_frags_ops); 752 if (ret) 753 goto err_pernet; 754 755 out: 756 return ret; 757 758 err_pernet: 759 ip6_frags_sysctl_unregister(); 760 err_sysctl: 761 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 762 err_protocol: 763 inet_frags_fini(&ip6_frags); 764 goto out; 765 } 766 767 void ipv6_frag_exit(void) 768 { 769 inet_frags_fini(&ip6_frags); 770 ip6_frags_sysctl_unregister(); 771 unregister_pernet_subsys(&ip6_frags_ops); 772 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 773 } 774