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 #include <linux/errno.h> 30 #include <linux/types.h> 31 #include <linux/string.h> 32 #include <linux/socket.h> 33 #include <linux/sockios.h> 34 #include <linux/jiffies.h> 35 #include <linux/net.h> 36 #include <linux/list.h> 37 #include <linux/netdevice.h> 38 #include <linux/in6.h> 39 #include <linux/ipv6.h> 40 #include <linux/icmpv6.h> 41 #include <linux/random.h> 42 #include <linux/jhash.h> 43 #include <linux/skbuff.h> 44 #include <linux/slab.h> 45 #include <linux/export.h> 46 47 #include <net/sock.h> 48 #include <net/snmp.h> 49 50 #include <net/ipv6.h> 51 #include <net/ip6_route.h> 52 #include <net/protocol.h> 53 #include <net/transp_v6.h> 54 #include <net/rawv6.h> 55 #include <net/ndisc.h> 56 #include <net/addrconf.h> 57 #include <net/inet_frag.h> 58 59 struct ip6frag_skb_cb 60 { 61 struct inet6_skb_parm h; 62 int offset; 63 }; 64 65 #define FRAG6_CB(skb) ((struct ip6frag_skb_cb*)((skb)->cb)) 66 67 68 static struct inet_frags ip6_frags; 69 70 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 71 struct net_device *dev); 72 73 /* 74 * callers should be careful not to use the hash value outside the ipfrag_lock 75 * as doing so could race with ipfrag_hash_rnd being recalculated. 76 */ 77 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, 78 const struct in6_addr *daddr, u32 rnd) 79 { 80 u32 c; 81 82 c = jhash_3words((__force u32)saddr->s6_addr32[0], 83 (__force u32)saddr->s6_addr32[1], 84 (__force u32)saddr->s6_addr32[2], 85 rnd); 86 87 c = jhash_3words((__force u32)saddr->s6_addr32[3], 88 (__force u32)daddr->s6_addr32[0], 89 (__force u32)daddr->s6_addr32[1], 90 c); 91 92 c = jhash_3words((__force u32)daddr->s6_addr32[2], 93 (__force u32)daddr->s6_addr32[3], 94 (__force u32)id, 95 c); 96 97 return c & (INETFRAGS_HASHSZ - 1); 98 } 99 EXPORT_SYMBOL_GPL(inet6_hash_frag); 100 101 static unsigned int ip6_hashfn(struct inet_frag_queue *q) 102 { 103 struct frag_queue *fq; 104 105 fq = container_of(q, struct frag_queue, q); 106 return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd); 107 } 108 109 bool ip6_frag_match(struct inet_frag_queue *q, void *a) 110 { 111 struct frag_queue *fq; 112 struct ip6_create_arg *arg = a; 113 114 fq = container_of(q, struct frag_queue, q); 115 return fq->id == arg->id && 116 fq->user == arg->user && 117 ipv6_addr_equal(&fq->saddr, arg->src) && 118 ipv6_addr_equal(&fq->daddr, arg->dst); 119 } 120 EXPORT_SYMBOL(ip6_frag_match); 121 122 void ip6_frag_init(struct inet_frag_queue *q, void *a) 123 { 124 struct frag_queue *fq = container_of(q, struct frag_queue, q); 125 struct ip6_create_arg *arg = a; 126 127 fq->id = arg->id; 128 fq->user = arg->user; 129 fq->saddr = *arg->src; 130 fq->daddr = *arg->dst; 131 } 132 EXPORT_SYMBOL(ip6_frag_init); 133 134 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq, 135 struct inet_frags *frags) 136 { 137 struct net_device *dev = NULL; 138 139 spin_lock(&fq->q.lock); 140 141 if (fq->q.last_in & INET_FRAG_COMPLETE) 142 goto out; 143 144 inet_frag_kill(&fq->q, frags); 145 146 rcu_read_lock(); 147 dev = dev_get_by_index_rcu(net, fq->iif); 148 if (!dev) 149 goto out_rcu_unlock; 150 151 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); 152 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 153 154 /* Don't send error if the first segment did not arrive. */ 155 if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments) 156 goto out_rcu_unlock; 157 158 /* 159 But use as source device on which LAST ARRIVED 160 segment was received. And do not use fq->dev 161 pointer directly, device might already disappeared. 162 */ 163 fq->q.fragments->dev = dev; 164 icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); 165 out_rcu_unlock: 166 rcu_read_unlock(); 167 out: 168 spin_unlock(&fq->q.lock); 169 inet_frag_put(&fq->q, frags); 170 } 171 EXPORT_SYMBOL(ip6_expire_frag_queue); 172 173 static void ip6_frag_expire(unsigned long data) 174 { 175 struct frag_queue *fq; 176 struct net *net; 177 178 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); 179 net = container_of(fq->q.net, struct net, ipv6.frags); 180 181 ip6_expire_frag_queue(net, fq, &ip6_frags); 182 } 183 184 static __inline__ struct frag_queue * 185 fq_find(struct net *net, __be32 id, const struct in6_addr *src, const struct in6_addr *dst) 186 { 187 struct inet_frag_queue *q; 188 struct ip6_create_arg arg; 189 unsigned int hash; 190 191 arg.id = id; 192 arg.user = IP6_DEFRAG_LOCAL_DELIVER; 193 arg.src = src; 194 arg.dst = dst; 195 196 read_lock(&ip6_frags.lock); 197 hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd); 198 199 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); 200 if (q == NULL) 201 return NULL; 202 203 return container_of(q, struct frag_queue, q); 204 } 205 206 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, 207 struct frag_hdr *fhdr, int nhoff) 208 { 209 struct sk_buff *prev, *next; 210 struct net_device *dev; 211 int offset, end; 212 struct net *net = dev_net(skb_dst(skb)->dev); 213 214 if (fq->q.last_in & INET_FRAG_COMPLETE) 215 goto err; 216 217 offset = ntohs(fhdr->frag_off) & ~0x7; 218 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - 219 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); 220 221 if ((unsigned int)end > IPV6_MAXPLEN) { 222 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 223 IPSTATS_MIB_INHDRERRORS); 224 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 225 ((u8 *)&fhdr->frag_off - 226 skb_network_header(skb))); 227 return -1; 228 } 229 230 if (skb->ip_summed == CHECKSUM_COMPLETE) { 231 const unsigned char *nh = skb_network_header(skb); 232 skb->csum = csum_sub(skb->csum, 233 csum_partial(nh, (u8 *)(fhdr + 1) - nh, 234 0)); 235 } 236 237 /* Is this the final fragment? */ 238 if (!(fhdr->frag_off & htons(IP6_MF))) { 239 /* If we already have some bits beyond end 240 * or have different end, the segment is corrupted. 241 */ 242 if (end < fq->q.len || 243 ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) 244 goto err; 245 fq->q.last_in |= INET_FRAG_LAST_IN; 246 fq->q.len = end; 247 } else { 248 /* Check if the fragment is rounded to 8 bytes. 249 * Required by the RFC. 250 */ 251 if (end & 0x7) { 252 /* RFC2460 says always send parameter problem in 253 * this case. -DaveM 254 */ 255 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 256 IPSTATS_MIB_INHDRERRORS); 257 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 258 offsetof(struct ipv6hdr, payload_len)); 259 return -1; 260 } 261 if (end > fq->q.len) { 262 /* Some bits beyond end -> corruption. */ 263 if (fq->q.last_in & INET_FRAG_LAST_IN) 264 goto err; 265 fq->q.len = end; 266 } 267 } 268 269 if (end == offset) 270 goto err; 271 272 /* Point into the IP datagram 'data' part. */ 273 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) 274 goto err; 275 276 if (pskb_trim_rcsum(skb, end - offset)) 277 goto err; 278 279 /* Find out which fragments are in front and at the back of us 280 * in the chain of fragments so far. We must know where to put 281 * this fragment, right? 282 */ 283 prev = fq->q.fragments_tail; 284 if (!prev || FRAG6_CB(prev)->offset < offset) { 285 next = NULL; 286 goto found; 287 } 288 prev = NULL; 289 for(next = fq->q.fragments; next != NULL; next = next->next) { 290 if (FRAG6_CB(next)->offset >= offset) 291 break; /* bingo! */ 292 prev = next; 293 } 294 295 found: 296 /* RFC5722, Section 4, amended by Errata ID : 3089 297 * When reassembling an IPv6 datagram, if 298 * one or more its constituent fragments is determined to be an 299 * overlapping fragment, the entire datagram (and any constituent 300 * fragments) MUST be silently discarded. 301 */ 302 303 /* Check for overlap with preceding fragment. */ 304 if (prev && 305 (FRAG6_CB(prev)->offset + prev->len) > offset) 306 goto discard_fq; 307 308 /* Look for overlap with succeeding segment. */ 309 if (next && FRAG6_CB(next)->offset < end) 310 goto discard_fq; 311 312 FRAG6_CB(skb)->offset = offset; 313 314 /* Insert this fragment in the chain of fragments. */ 315 skb->next = next; 316 if (!next) 317 fq->q.fragments_tail = skb; 318 if (prev) 319 prev->next = skb; 320 else 321 fq->q.fragments = skb; 322 323 dev = skb->dev; 324 if (dev) { 325 fq->iif = dev->ifindex; 326 skb->dev = NULL; 327 } 328 fq->q.stamp = skb->tstamp; 329 fq->q.meat += skb->len; 330 atomic_add(skb->truesize, &fq->q.net->mem); 331 332 /* The first fragment. 333 * nhoffset is obtained from the first fragment, of course. 334 */ 335 if (offset == 0) { 336 fq->nhoffset = nhoff; 337 fq->q.last_in |= INET_FRAG_FIRST_IN; 338 } 339 340 if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 341 fq->q.meat == fq->q.len) 342 return ip6_frag_reasm(fq, prev, dev); 343 344 write_lock(&ip6_frags.lock); 345 list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list); 346 write_unlock(&ip6_frags.lock); 347 return -1; 348 349 discard_fq: 350 inet_frag_kill(&fq->q, &ip6_frags); 351 err: 352 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 353 IPSTATS_MIB_REASMFAILS); 354 kfree_skb(skb); 355 return -1; 356 } 357 358 /* 359 * Check if this packet is complete. 360 * Returns NULL on failure by any reason, and pointer 361 * to current nexthdr field in reassembled frame. 362 * 363 * It is called with locked fq, and caller must check that 364 * queue is eligible for reassembly i.e. it is not COMPLETE, 365 * the last and the first frames arrived and all the bits are here. 366 */ 367 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 368 struct net_device *dev) 369 { 370 struct net *net = container_of(fq->q.net, struct net, ipv6.frags); 371 struct sk_buff *fp, *head = fq->q.fragments; 372 int payload_len; 373 unsigned int nhoff; 374 int sum_truesize; 375 376 inet_frag_kill(&fq->q, &ip6_frags); 377 378 /* Make the one we just received the head. */ 379 if (prev) { 380 head = prev->next; 381 fp = skb_clone(head, GFP_ATOMIC); 382 383 if (!fp) 384 goto out_oom; 385 386 fp->next = head->next; 387 if (!fp->next) 388 fq->q.fragments_tail = fp; 389 prev->next = fp; 390 391 skb_morph(head, fq->q.fragments); 392 head->next = fq->q.fragments->next; 393 394 consume_skb(fq->q.fragments); 395 fq->q.fragments = head; 396 } 397 398 WARN_ON(head == NULL); 399 WARN_ON(FRAG6_CB(head)->offset != 0); 400 401 /* Unfragmented part is taken from the first segment. */ 402 payload_len = ((head->data - skb_network_header(head)) - 403 sizeof(struct ipv6hdr) + fq->q.len - 404 sizeof(struct frag_hdr)); 405 if (payload_len > IPV6_MAXPLEN) 406 goto out_oversize; 407 408 /* Head of list must not be cloned. */ 409 if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) 410 goto out_oom; 411 412 /* If the first fragment is fragmented itself, we split 413 * it to two chunks: the first with data and paged part 414 * and the second, holding only fragments. */ 415 if (skb_has_frag_list(head)) { 416 struct sk_buff *clone; 417 int i, plen = 0; 418 419 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) 420 goto out_oom; 421 clone->next = head->next; 422 head->next = clone; 423 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 424 skb_frag_list_init(head); 425 for (i = 0; i < skb_shinfo(head)->nr_frags; i++) 426 plen += skb_frag_size(&skb_shinfo(head)->frags[i]); 427 clone->len = clone->data_len = head->data_len - plen; 428 head->data_len -= clone->len; 429 head->len -= clone->len; 430 clone->csum = 0; 431 clone->ip_summed = head->ip_summed; 432 atomic_add(clone->truesize, &fq->q.net->mem); 433 } 434 435 /* We have to remove fragment header from datagram and to relocate 436 * header in order to calculate ICV correctly. */ 437 nhoff = fq->nhoffset; 438 skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; 439 memmove(head->head + sizeof(struct frag_hdr), head->head, 440 (head->data - head->head) - sizeof(struct frag_hdr)); 441 head->mac_header += sizeof(struct frag_hdr); 442 head->network_header += sizeof(struct frag_hdr); 443 444 skb_reset_transport_header(head); 445 skb_push(head, head->data - skb_network_header(head)); 446 447 sum_truesize = head->truesize; 448 for (fp = head->next; fp;) { 449 bool headstolen; 450 int delta; 451 struct sk_buff *next = fp->next; 452 453 sum_truesize += fp->truesize; 454 if (head->ip_summed != fp->ip_summed) 455 head->ip_summed = CHECKSUM_NONE; 456 else if (head->ip_summed == CHECKSUM_COMPLETE) 457 head->csum = csum_add(head->csum, fp->csum); 458 459 if (skb_try_coalesce(head, fp, &headstolen, &delta)) { 460 kfree_skb_partial(fp, headstolen); 461 } else { 462 if (!skb_shinfo(head)->frag_list) 463 skb_shinfo(head)->frag_list = fp; 464 head->data_len += fp->len; 465 head->len += fp->len; 466 head->truesize += fp->truesize; 467 } 468 fp = next; 469 } 470 atomic_sub(sum_truesize, &fq->q.net->mem); 471 472 head->next = NULL; 473 head->dev = dev; 474 head->tstamp = fq->q.stamp; 475 ipv6_hdr(head)->payload_len = htons(payload_len); 476 IP6CB(head)->nhoff = nhoff; 477 478 /* Yes, and fold redundant checksum back. 8) */ 479 if (head->ip_summed == CHECKSUM_COMPLETE) 480 head->csum = csum_partial(skb_network_header(head), 481 skb_network_header_len(head), 482 head->csum); 483 484 rcu_read_lock(); 485 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); 486 rcu_read_unlock(); 487 fq->q.fragments = NULL; 488 fq->q.fragments_tail = NULL; 489 return 1; 490 491 out_oversize: 492 net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); 493 goto out_fail; 494 out_oom: 495 net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); 496 out_fail: 497 rcu_read_lock(); 498 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 499 rcu_read_unlock(); 500 return -1; 501 } 502 503 static int ipv6_frag_rcv(struct sk_buff *skb) 504 { 505 struct frag_hdr *fhdr; 506 struct frag_queue *fq; 507 const struct ipv6hdr *hdr = ipv6_hdr(skb); 508 struct net *net = dev_net(skb_dst(skb)->dev); 509 int evicted; 510 511 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); 512 513 /* Jumbo payload inhibits frag. header */ 514 if (hdr->payload_len==0) 515 goto fail_hdr; 516 517 if (!pskb_may_pull(skb, (skb_transport_offset(skb) + 518 sizeof(struct frag_hdr)))) 519 goto fail_hdr; 520 521 hdr = ipv6_hdr(skb); 522 fhdr = (struct frag_hdr *)skb_transport_header(skb); 523 524 if (!(fhdr->frag_off & htons(0xFFF9))) { 525 /* It is not a fragmented frame */ 526 skb->transport_header += sizeof(struct frag_hdr); 527 IP6_INC_STATS_BH(net, 528 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); 529 530 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); 531 return 1; 532 } 533 534 evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags, false); 535 if (evicted) 536 IP6_ADD_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 537 IPSTATS_MIB_REASMFAILS, evicted); 538 539 fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr); 540 if (fq != NULL) { 541 int ret; 542 543 spin_lock(&fq->q.lock); 544 545 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); 546 547 spin_unlock(&fq->q.lock); 548 inet_frag_put(&fq->q, &ip6_frags); 549 return ret; 550 } 551 552 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); 553 kfree_skb(skb); 554 return -1; 555 556 fail_hdr: 557 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); 558 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); 559 return -1; 560 } 561 562 static const struct inet6_protocol frag_protocol = 563 { 564 .handler = ipv6_frag_rcv, 565 .flags = INET6_PROTO_NOPOLICY, 566 }; 567 568 #ifdef CONFIG_SYSCTL 569 static struct ctl_table ip6_frags_ns_ctl_table[] = { 570 { 571 .procname = "ip6frag_high_thresh", 572 .data = &init_net.ipv6.frags.high_thresh, 573 .maxlen = sizeof(int), 574 .mode = 0644, 575 .proc_handler = proc_dointvec 576 }, 577 { 578 .procname = "ip6frag_low_thresh", 579 .data = &init_net.ipv6.frags.low_thresh, 580 .maxlen = sizeof(int), 581 .mode = 0644, 582 .proc_handler = proc_dointvec 583 }, 584 { 585 .procname = "ip6frag_time", 586 .data = &init_net.ipv6.frags.timeout, 587 .maxlen = sizeof(int), 588 .mode = 0644, 589 .proc_handler = proc_dointvec_jiffies, 590 }, 591 { } 592 }; 593 594 static struct ctl_table ip6_frags_ctl_table[] = { 595 { 596 .procname = "ip6frag_secret_interval", 597 .data = &ip6_frags.secret_interval, 598 .maxlen = sizeof(int), 599 .mode = 0644, 600 .proc_handler = proc_dointvec_jiffies, 601 }, 602 { } 603 }; 604 605 static int __net_init ip6_frags_ns_sysctl_register(struct net *net) 606 { 607 struct ctl_table *table; 608 struct ctl_table_header *hdr; 609 610 table = ip6_frags_ns_ctl_table; 611 if (!net_eq(net, &init_net)) { 612 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); 613 if (table == NULL) 614 goto err_alloc; 615 616 table[0].data = &net->ipv6.frags.high_thresh; 617 table[1].data = &net->ipv6.frags.low_thresh; 618 table[2].data = &net->ipv6.frags.timeout; 619 620 /* Don't export sysctls to unprivileged users */ 621 if (net->user_ns != &init_user_ns) 622 table[0].procname = NULL; 623 } 624 625 hdr = register_net_sysctl(net, "net/ipv6", table); 626 if (hdr == NULL) 627 goto err_reg; 628 629 net->ipv6.sysctl.frags_hdr = hdr; 630 return 0; 631 632 err_reg: 633 if (!net_eq(net, &init_net)) 634 kfree(table); 635 err_alloc: 636 return -ENOMEM; 637 } 638 639 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) 640 { 641 struct ctl_table *table; 642 643 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; 644 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); 645 if (!net_eq(net, &init_net)) 646 kfree(table); 647 } 648 649 static struct ctl_table_header *ip6_ctl_header; 650 651 static int ip6_frags_sysctl_register(void) 652 { 653 ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", 654 ip6_frags_ctl_table); 655 return ip6_ctl_header == NULL ? -ENOMEM : 0; 656 } 657 658 static void ip6_frags_sysctl_unregister(void) 659 { 660 unregister_net_sysctl_table(ip6_ctl_header); 661 } 662 #else 663 static inline int ip6_frags_ns_sysctl_register(struct net *net) 664 { 665 return 0; 666 } 667 668 static inline void ip6_frags_ns_sysctl_unregister(struct net *net) 669 { 670 } 671 672 static inline int ip6_frags_sysctl_register(void) 673 { 674 return 0; 675 } 676 677 static inline void ip6_frags_sysctl_unregister(void) 678 { 679 } 680 #endif 681 682 static int __net_init ipv6_frags_init_net(struct net *net) 683 { 684 net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; 685 net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; 686 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; 687 688 inet_frags_init_net(&net->ipv6.frags); 689 690 return ip6_frags_ns_sysctl_register(net); 691 } 692 693 static void __net_exit ipv6_frags_exit_net(struct net *net) 694 { 695 ip6_frags_ns_sysctl_unregister(net); 696 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); 697 } 698 699 static struct pernet_operations ip6_frags_ops = { 700 .init = ipv6_frags_init_net, 701 .exit = ipv6_frags_exit_net, 702 }; 703 704 int __init ipv6_frag_init(void) 705 { 706 int ret; 707 708 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); 709 if (ret) 710 goto out; 711 712 ret = ip6_frags_sysctl_register(); 713 if (ret) 714 goto err_sysctl; 715 716 ret = register_pernet_subsys(&ip6_frags_ops); 717 if (ret) 718 goto err_pernet; 719 720 ip6_frags.hashfn = ip6_hashfn; 721 ip6_frags.constructor = ip6_frag_init; 722 ip6_frags.destructor = NULL; 723 ip6_frags.skb_free = NULL; 724 ip6_frags.qsize = sizeof(struct frag_queue); 725 ip6_frags.match = ip6_frag_match; 726 ip6_frags.frag_expire = ip6_frag_expire; 727 ip6_frags.secret_interval = 10 * 60 * HZ; 728 inet_frags_init(&ip6_frags); 729 out: 730 return ret; 731 732 err_pernet: 733 ip6_frags_sysctl_unregister(); 734 err_sysctl: 735 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 736 goto out; 737 } 738 739 void ipv6_frag_exit(void) 740 { 741 inet_frags_fini(&ip6_frags); 742 ip6_frags_sysctl_unregister(); 743 unregister_pernet_subsys(&ip6_frags_ops); 744 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 745 } 746