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 /* 69 * Equivalent of ipv4 struct ipq 70 */ 71 72 struct frag_queue 73 { 74 struct inet_frag_queue q; 75 76 __be32 id; /* fragment id */ 77 u32 user; 78 struct in6_addr saddr; 79 struct in6_addr daddr; 80 81 int iif; 82 unsigned int csum; 83 __u16 nhoffset; 84 }; 85 86 static struct inet_frags ip6_frags; 87 88 int ip6_frag_nqueues(struct net *net) 89 { 90 return net->ipv6.frags.nqueues; 91 } 92 93 int ip6_frag_mem(struct net *net) 94 { 95 return atomic_read(&net->ipv6.frags.mem); 96 } 97 98 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 99 struct net_device *dev); 100 101 /* 102 * callers should be careful not to use the hash value outside the ipfrag_lock 103 * as doing so could race with ipfrag_hash_rnd being recalculated. 104 */ 105 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, 106 const struct in6_addr *daddr, u32 rnd) 107 { 108 u32 c; 109 110 c = jhash_3words((__force u32)saddr->s6_addr32[0], 111 (__force u32)saddr->s6_addr32[1], 112 (__force u32)saddr->s6_addr32[2], 113 rnd); 114 115 c = jhash_3words((__force u32)saddr->s6_addr32[3], 116 (__force u32)daddr->s6_addr32[0], 117 (__force u32)daddr->s6_addr32[1], 118 c); 119 120 c = jhash_3words((__force u32)daddr->s6_addr32[2], 121 (__force u32)daddr->s6_addr32[3], 122 (__force u32)id, 123 c); 124 125 return c & (INETFRAGS_HASHSZ - 1); 126 } 127 EXPORT_SYMBOL_GPL(inet6_hash_frag); 128 129 static unsigned int ip6_hashfn(struct inet_frag_queue *q) 130 { 131 struct frag_queue *fq; 132 133 fq = container_of(q, struct frag_queue, q); 134 return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd); 135 } 136 137 bool ip6_frag_match(struct inet_frag_queue *q, void *a) 138 { 139 struct frag_queue *fq; 140 struct ip6_create_arg *arg = a; 141 142 fq = container_of(q, struct frag_queue, q); 143 return fq->id == arg->id && 144 fq->user == arg->user && 145 ipv6_addr_equal(&fq->saddr, arg->src) && 146 ipv6_addr_equal(&fq->daddr, arg->dst); 147 } 148 EXPORT_SYMBOL(ip6_frag_match); 149 150 void ip6_frag_init(struct inet_frag_queue *q, void *a) 151 { 152 struct frag_queue *fq = container_of(q, struct frag_queue, q); 153 struct ip6_create_arg *arg = a; 154 155 fq->id = arg->id; 156 fq->user = arg->user; 157 fq->saddr = *arg->src; 158 fq->daddr = *arg->dst; 159 } 160 EXPORT_SYMBOL(ip6_frag_init); 161 162 /* Destruction primitives. */ 163 164 static __inline__ void fq_put(struct frag_queue *fq) 165 { 166 inet_frag_put(&fq->q, &ip6_frags); 167 } 168 169 /* Kill fq entry. It is not destroyed immediately, 170 * because caller (and someone more) holds reference count. 171 */ 172 static __inline__ void fq_kill(struct frag_queue *fq) 173 { 174 inet_frag_kill(&fq->q, &ip6_frags); 175 } 176 177 static void ip6_evictor(struct net *net, struct inet6_dev *idev) 178 { 179 int evicted; 180 181 evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags); 182 if (evicted) 183 IP6_ADD_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS, evicted); 184 } 185 186 static void ip6_frag_expire(unsigned long data) 187 { 188 struct frag_queue *fq; 189 struct net_device *dev = NULL; 190 struct net *net; 191 192 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); 193 194 spin_lock(&fq->q.lock); 195 196 if (fq->q.last_in & INET_FRAG_COMPLETE) 197 goto out; 198 199 fq_kill(fq); 200 201 net = container_of(fq->q.net, struct net, ipv6.frags); 202 rcu_read_lock(); 203 dev = dev_get_by_index_rcu(net, fq->iif); 204 if (!dev) 205 goto out_rcu_unlock; 206 207 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); 208 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 209 210 /* Don't send error if the first segment did not arrive. */ 211 if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments) 212 goto out_rcu_unlock; 213 214 /* 215 But use as source device on which LAST ARRIVED 216 segment was received. And do not use fq->dev 217 pointer directly, device might already disappeared. 218 */ 219 fq->q.fragments->dev = dev; 220 icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); 221 out_rcu_unlock: 222 rcu_read_unlock(); 223 out: 224 spin_unlock(&fq->q.lock); 225 fq_put(fq); 226 } 227 228 static __inline__ struct frag_queue * 229 fq_find(struct net *net, __be32 id, const struct in6_addr *src, const struct in6_addr *dst) 230 { 231 struct inet_frag_queue *q; 232 struct ip6_create_arg arg; 233 unsigned int hash; 234 235 arg.id = id; 236 arg.user = IP6_DEFRAG_LOCAL_DELIVER; 237 arg.src = src; 238 arg.dst = dst; 239 240 read_lock(&ip6_frags.lock); 241 hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd); 242 243 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); 244 if (q == NULL) 245 return NULL; 246 247 return container_of(q, struct frag_queue, q); 248 } 249 250 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, 251 struct frag_hdr *fhdr, int nhoff) 252 { 253 struct sk_buff *prev, *next; 254 struct net_device *dev; 255 int offset, end; 256 struct net *net = dev_net(skb_dst(skb)->dev); 257 258 if (fq->q.last_in & INET_FRAG_COMPLETE) 259 goto err; 260 261 offset = ntohs(fhdr->frag_off) & ~0x7; 262 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - 263 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); 264 265 if ((unsigned int)end > IPV6_MAXPLEN) { 266 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 267 IPSTATS_MIB_INHDRERRORS); 268 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 269 ((u8 *)&fhdr->frag_off - 270 skb_network_header(skb))); 271 return -1; 272 } 273 274 if (skb->ip_summed == CHECKSUM_COMPLETE) { 275 const unsigned char *nh = skb_network_header(skb); 276 skb->csum = csum_sub(skb->csum, 277 csum_partial(nh, (u8 *)(fhdr + 1) - nh, 278 0)); 279 } 280 281 /* Is this the final fragment? */ 282 if (!(fhdr->frag_off & htons(IP6_MF))) { 283 /* If we already have some bits beyond end 284 * or have different end, the segment is corrupted. 285 */ 286 if (end < fq->q.len || 287 ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) 288 goto err; 289 fq->q.last_in |= INET_FRAG_LAST_IN; 290 fq->q.len = end; 291 } else { 292 /* Check if the fragment is rounded to 8 bytes. 293 * Required by the RFC. 294 */ 295 if (end & 0x7) { 296 /* RFC2460 says always send parameter problem in 297 * this case. -DaveM 298 */ 299 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 300 IPSTATS_MIB_INHDRERRORS); 301 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 302 offsetof(struct ipv6hdr, payload_len)); 303 return -1; 304 } 305 if (end > fq->q.len) { 306 /* Some bits beyond end -> corruption. */ 307 if (fq->q.last_in & INET_FRAG_LAST_IN) 308 goto err; 309 fq->q.len = end; 310 } 311 } 312 313 if (end == offset) 314 goto err; 315 316 /* Point into the IP datagram 'data' part. */ 317 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) 318 goto err; 319 320 if (pskb_trim_rcsum(skb, end - offset)) 321 goto err; 322 323 /* Find out which fragments are in front and at the back of us 324 * in the chain of fragments so far. We must know where to put 325 * this fragment, right? 326 */ 327 prev = fq->q.fragments_tail; 328 if (!prev || FRAG6_CB(prev)->offset < offset) { 329 next = NULL; 330 goto found; 331 } 332 prev = NULL; 333 for(next = fq->q.fragments; next != NULL; next = next->next) { 334 if (FRAG6_CB(next)->offset >= offset) 335 break; /* bingo! */ 336 prev = next; 337 } 338 339 found: 340 /* RFC5722, Section 4, amended by Errata ID : 3089 341 * When reassembling an IPv6 datagram, if 342 * one or more its constituent fragments is determined to be an 343 * overlapping fragment, the entire datagram (and any constituent 344 * fragments) MUST be silently discarded. 345 */ 346 347 /* Check for overlap with preceding fragment. */ 348 if (prev && 349 (FRAG6_CB(prev)->offset + prev->len) > offset) 350 goto discard_fq; 351 352 /* Look for overlap with succeeding segment. */ 353 if (next && FRAG6_CB(next)->offset < end) 354 goto discard_fq; 355 356 FRAG6_CB(skb)->offset = offset; 357 358 /* Insert this fragment in the chain of fragments. */ 359 skb->next = next; 360 if (!next) 361 fq->q.fragments_tail = skb; 362 if (prev) 363 prev->next = skb; 364 else 365 fq->q.fragments = skb; 366 367 dev = skb->dev; 368 if (dev) { 369 fq->iif = dev->ifindex; 370 skb->dev = NULL; 371 } 372 fq->q.stamp = skb->tstamp; 373 fq->q.meat += skb->len; 374 atomic_add(skb->truesize, &fq->q.net->mem); 375 376 /* The first fragment. 377 * nhoffset is obtained from the first fragment, of course. 378 */ 379 if (offset == 0) { 380 fq->nhoffset = nhoff; 381 fq->q.last_in |= INET_FRAG_FIRST_IN; 382 } 383 384 if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 385 fq->q.meat == fq->q.len) 386 return ip6_frag_reasm(fq, prev, dev); 387 388 write_lock(&ip6_frags.lock); 389 list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list); 390 write_unlock(&ip6_frags.lock); 391 return -1; 392 393 discard_fq: 394 fq_kill(fq); 395 err: 396 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 397 IPSTATS_MIB_REASMFAILS); 398 kfree_skb(skb); 399 return -1; 400 } 401 402 /* 403 * Check if this packet is complete. 404 * Returns NULL on failure by any reason, and pointer 405 * to current nexthdr field in reassembled frame. 406 * 407 * It is called with locked fq, and caller must check that 408 * queue is eligible for reassembly i.e. it is not COMPLETE, 409 * the last and the first frames arrived and all the bits are here. 410 */ 411 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 412 struct net_device *dev) 413 { 414 struct net *net = container_of(fq->q.net, struct net, ipv6.frags); 415 struct sk_buff *fp, *head = fq->q.fragments; 416 int payload_len; 417 unsigned int nhoff; 418 int sum_truesize; 419 420 fq_kill(fq); 421 422 /* Make the one we just received the head. */ 423 if (prev) { 424 head = prev->next; 425 fp = skb_clone(head, GFP_ATOMIC); 426 427 if (!fp) 428 goto out_oom; 429 430 fp->next = head->next; 431 if (!fp->next) 432 fq->q.fragments_tail = fp; 433 prev->next = fp; 434 435 skb_morph(head, fq->q.fragments); 436 head->next = fq->q.fragments->next; 437 438 consume_skb(fq->q.fragments); 439 fq->q.fragments = head; 440 } 441 442 WARN_ON(head == NULL); 443 WARN_ON(FRAG6_CB(head)->offset != 0); 444 445 /* Unfragmented part is taken from the first segment. */ 446 payload_len = ((head->data - skb_network_header(head)) - 447 sizeof(struct ipv6hdr) + fq->q.len - 448 sizeof(struct frag_hdr)); 449 if (payload_len > IPV6_MAXPLEN) 450 goto out_oversize; 451 452 /* Head of list must not be cloned. */ 453 if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) 454 goto out_oom; 455 456 /* If the first fragment is fragmented itself, we split 457 * it to two chunks: the first with data and paged part 458 * and the second, holding only fragments. */ 459 if (skb_has_frag_list(head)) { 460 struct sk_buff *clone; 461 int i, plen = 0; 462 463 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) 464 goto out_oom; 465 clone->next = head->next; 466 head->next = clone; 467 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 468 skb_frag_list_init(head); 469 for (i = 0; i < skb_shinfo(head)->nr_frags; i++) 470 plen += skb_frag_size(&skb_shinfo(head)->frags[i]); 471 clone->len = clone->data_len = head->data_len - plen; 472 head->data_len -= clone->len; 473 head->len -= clone->len; 474 clone->csum = 0; 475 clone->ip_summed = head->ip_summed; 476 atomic_add(clone->truesize, &fq->q.net->mem); 477 } 478 479 /* We have to remove fragment header from datagram and to relocate 480 * header in order to calculate ICV correctly. */ 481 nhoff = fq->nhoffset; 482 skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; 483 memmove(head->head + sizeof(struct frag_hdr), head->head, 484 (head->data - head->head) - sizeof(struct frag_hdr)); 485 head->mac_header += sizeof(struct frag_hdr); 486 head->network_header += sizeof(struct frag_hdr); 487 488 skb_reset_transport_header(head); 489 skb_push(head, head->data - skb_network_header(head)); 490 491 sum_truesize = head->truesize; 492 for (fp = head->next; fp;) { 493 bool headstolen; 494 int delta; 495 struct sk_buff *next = fp->next; 496 497 sum_truesize += fp->truesize; 498 if (head->ip_summed != fp->ip_summed) 499 head->ip_summed = CHECKSUM_NONE; 500 else if (head->ip_summed == CHECKSUM_COMPLETE) 501 head->csum = csum_add(head->csum, fp->csum); 502 503 if (skb_try_coalesce(head, fp, &headstolen, &delta)) { 504 kfree_skb_partial(fp, headstolen); 505 } else { 506 if (!skb_shinfo(head)->frag_list) 507 skb_shinfo(head)->frag_list = fp; 508 head->data_len += fp->len; 509 head->len += fp->len; 510 head->truesize += fp->truesize; 511 } 512 fp = next; 513 } 514 atomic_sub(sum_truesize, &fq->q.net->mem); 515 516 head->next = NULL; 517 head->dev = dev; 518 head->tstamp = fq->q.stamp; 519 ipv6_hdr(head)->payload_len = htons(payload_len); 520 IP6CB(head)->nhoff = nhoff; 521 522 /* Yes, and fold redundant checksum back. 8) */ 523 if (head->ip_summed == CHECKSUM_COMPLETE) 524 head->csum = csum_partial(skb_network_header(head), 525 skb_network_header_len(head), 526 head->csum); 527 528 rcu_read_lock(); 529 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); 530 rcu_read_unlock(); 531 fq->q.fragments = NULL; 532 fq->q.fragments_tail = NULL; 533 return 1; 534 535 out_oversize: 536 net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); 537 goto out_fail; 538 out_oom: 539 net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); 540 out_fail: 541 rcu_read_lock(); 542 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 543 rcu_read_unlock(); 544 return -1; 545 } 546 547 static int ipv6_frag_rcv(struct sk_buff *skb) 548 { 549 struct frag_hdr *fhdr; 550 struct frag_queue *fq; 551 const struct ipv6hdr *hdr = ipv6_hdr(skb); 552 struct net *net = dev_net(skb_dst(skb)->dev); 553 554 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); 555 556 /* Jumbo payload inhibits frag. header */ 557 if (hdr->payload_len==0) 558 goto fail_hdr; 559 560 if (!pskb_may_pull(skb, (skb_transport_offset(skb) + 561 sizeof(struct frag_hdr)))) 562 goto fail_hdr; 563 564 hdr = ipv6_hdr(skb); 565 fhdr = (struct frag_hdr *)skb_transport_header(skb); 566 567 if (!(fhdr->frag_off & htons(0xFFF9))) { 568 /* It is not a fragmented frame */ 569 skb->transport_header += sizeof(struct frag_hdr); 570 IP6_INC_STATS_BH(net, 571 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); 572 573 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); 574 return 1; 575 } 576 577 if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh) 578 ip6_evictor(net, ip6_dst_idev(skb_dst(skb))); 579 580 fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr); 581 if (fq != NULL) { 582 int ret; 583 584 spin_lock(&fq->q.lock); 585 586 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); 587 588 spin_unlock(&fq->q.lock); 589 fq_put(fq); 590 return ret; 591 } 592 593 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); 594 kfree_skb(skb); 595 return -1; 596 597 fail_hdr: 598 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); 599 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); 600 return -1; 601 } 602 603 static const struct inet6_protocol frag_protocol = 604 { 605 .handler = ipv6_frag_rcv, 606 .flags = INET6_PROTO_NOPOLICY, 607 }; 608 609 #ifdef CONFIG_SYSCTL 610 static struct ctl_table ip6_frags_ns_ctl_table[] = { 611 { 612 .procname = "ip6frag_high_thresh", 613 .data = &init_net.ipv6.frags.high_thresh, 614 .maxlen = sizeof(int), 615 .mode = 0644, 616 .proc_handler = proc_dointvec 617 }, 618 { 619 .procname = "ip6frag_low_thresh", 620 .data = &init_net.ipv6.frags.low_thresh, 621 .maxlen = sizeof(int), 622 .mode = 0644, 623 .proc_handler = proc_dointvec 624 }, 625 { 626 .procname = "ip6frag_time", 627 .data = &init_net.ipv6.frags.timeout, 628 .maxlen = sizeof(int), 629 .mode = 0644, 630 .proc_handler = proc_dointvec_jiffies, 631 }, 632 { } 633 }; 634 635 static struct ctl_table ip6_frags_ctl_table[] = { 636 { 637 .procname = "ip6frag_secret_interval", 638 .data = &ip6_frags.secret_interval, 639 .maxlen = sizeof(int), 640 .mode = 0644, 641 .proc_handler = proc_dointvec_jiffies, 642 }, 643 { } 644 }; 645 646 static int __net_init ip6_frags_ns_sysctl_register(struct net *net) 647 { 648 struct ctl_table *table; 649 struct ctl_table_header *hdr; 650 651 table = ip6_frags_ns_ctl_table; 652 if (!net_eq(net, &init_net)) { 653 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); 654 if (table == NULL) 655 goto err_alloc; 656 657 table[0].data = &net->ipv6.frags.high_thresh; 658 table[1].data = &net->ipv6.frags.low_thresh; 659 table[2].data = &net->ipv6.frags.timeout; 660 } 661 662 hdr = register_net_sysctl(net, "net/ipv6", table); 663 if (hdr == NULL) 664 goto err_reg; 665 666 net->ipv6.sysctl.frags_hdr = hdr; 667 return 0; 668 669 err_reg: 670 if (!net_eq(net, &init_net)) 671 kfree(table); 672 err_alloc: 673 return -ENOMEM; 674 } 675 676 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) 677 { 678 struct ctl_table *table; 679 680 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; 681 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); 682 if (!net_eq(net, &init_net)) 683 kfree(table); 684 } 685 686 static struct ctl_table_header *ip6_ctl_header; 687 688 static int ip6_frags_sysctl_register(void) 689 { 690 ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", 691 ip6_frags_ctl_table); 692 return ip6_ctl_header == NULL ? -ENOMEM : 0; 693 } 694 695 static void ip6_frags_sysctl_unregister(void) 696 { 697 unregister_net_sysctl_table(ip6_ctl_header); 698 } 699 #else 700 static inline int ip6_frags_ns_sysctl_register(struct net *net) 701 { 702 return 0; 703 } 704 705 static inline void ip6_frags_ns_sysctl_unregister(struct net *net) 706 { 707 } 708 709 static inline int ip6_frags_sysctl_register(void) 710 { 711 return 0; 712 } 713 714 static inline void ip6_frags_sysctl_unregister(void) 715 { 716 } 717 #endif 718 719 static int __net_init ipv6_frags_init_net(struct net *net) 720 { 721 net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; 722 net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; 723 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; 724 725 inet_frags_init_net(&net->ipv6.frags); 726 727 return ip6_frags_ns_sysctl_register(net); 728 } 729 730 static void __net_exit ipv6_frags_exit_net(struct net *net) 731 { 732 ip6_frags_ns_sysctl_unregister(net); 733 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); 734 } 735 736 static struct pernet_operations ip6_frags_ops = { 737 .init = ipv6_frags_init_net, 738 .exit = ipv6_frags_exit_net, 739 }; 740 741 int __init ipv6_frag_init(void) 742 { 743 int ret; 744 745 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); 746 if (ret) 747 goto out; 748 749 ret = ip6_frags_sysctl_register(); 750 if (ret) 751 goto err_sysctl; 752 753 ret = register_pernet_subsys(&ip6_frags_ops); 754 if (ret) 755 goto err_pernet; 756 757 ip6_frags.hashfn = ip6_hashfn; 758 ip6_frags.constructor = ip6_frag_init; 759 ip6_frags.destructor = NULL; 760 ip6_frags.skb_free = NULL; 761 ip6_frags.qsize = sizeof(struct frag_queue); 762 ip6_frags.match = ip6_frag_match; 763 ip6_frags.frag_expire = ip6_frag_expire; 764 ip6_frags.secret_interval = 10 * 60 * HZ; 765 inet_frags_init(&ip6_frags); 766 out: 767 return ret; 768 769 err_pernet: 770 ip6_frags_sysctl_unregister(); 771 err_sysctl: 772 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 773 goto out; 774 } 775 776 void ipv6_frag_exit(void) 777 { 778 inet_frags_fini(&ip6_frags); 779 ip6_frags_sysctl_unregister(); 780 unregister_pernet_subsys(&ip6_frags_ops); 781 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 782 } 783