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 46 #include <net/sock.h> 47 #include <net/snmp.h> 48 49 #include <net/ipv6.h> 50 #include <net/ip6_route.h> 51 #include <net/protocol.h> 52 #include <net/transp_v6.h> 53 #include <net/rawv6.h> 54 #include <net/ndisc.h> 55 #include <net/addrconf.h> 56 #include <net/inet_frag.h> 57 58 struct ip6frag_skb_cb 59 { 60 struct inet6_skb_parm h; 61 int offset; 62 }; 63 64 #define FRAG6_CB(skb) ((struct ip6frag_skb_cb*)((skb)->cb)) 65 66 67 /* 68 * Equivalent of ipv4 struct ipq 69 */ 70 71 struct frag_queue 72 { 73 struct inet_frag_queue q; 74 75 __be32 id; /* fragment id */ 76 u32 user; 77 struct in6_addr saddr; 78 struct in6_addr daddr; 79 80 int iif; 81 unsigned int csum; 82 __u16 nhoffset; 83 }; 84 85 static struct inet_frags ip6_frags; 86 87 int ip6_frag_nqueues(struct net *net) 88 { 89 return net->ipv6.frags.nqueues; 90 } 91 92 int ip6_frag_mem(struct net *net) 93 { 94 return atomic_read(&net->ipv6.frags.mem); 95 } 96 97 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 98 struct net_device *dev); 99 100 /* 101 * callers should be careful not to use the hash value outside the ipfrag_lock 102 * as doing so could race with ipfrag_hash_rnd being recalculated. 103 */ 104 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, 105 const struct in6_addr *daddr, u32 rnd) 106 { 107 u32 a, b, c; 108 109 a = (__force u32)saddr->s6_addr32[0]; 110 b = (__force u32)saddr->s6_addr32[1]; 111 c = (__force u32)saddr->s6_addr32[2]; 112 113 a += JHASH_GOLDEN_RATIO; 114 b += JHASH_GOLDEN_RATIO; 115 c += rnd; 116 __jhash_mix(a, b, c); 117 118 a += (__force u32)saddr->s6_addr32[3]; 119 b += (__force u32)daddr->s6_addr32[0]; 120 c += (__force u32)daddr->s6_addr32[1]; 121 __jhash_mix(a, b, c); 122 123 a += (__force u32)daddr->s6_addr32[2]; 124 b += (__force u32)daddr->s6_addr32[3]; 125 c += (__force u32)id; 126 __jhash_mix(a, b, c); 127 128 return c & (INETFRAGS_HASHSZ - 1); 129 } 130 EXPORT_SYMBOL_GPL(inet6_hash_frag); 131 132 static unsigned int ip6_hashfn(struct inet_frag_queue *q) 133 { 134 struct frag_queue *fq; 135 136 fq = container_of(q, struct frag_queue, q); 137 return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd); 138 } 139 140 int ip6_frag_match(struct inet_frag_queue *q, void *a) 141 { 142 struct frag_queue *fq; 143 struct ip6_create_arg *arg = a; 144 145 fq = container_of(q, struct frag_queue, q); 146 return (fq->id == arg->id && fq->user == arg->user && 147 ipv6_addr_equal(&fq->saddr, arg->src) && 148 ipv6_addr_equal(&fq->daddr, arg->dst)); 149 } 150 EXPORT_SYMBOL(ip6_frag_match); 151 152 void ip6_frag_init(struct inet_frag_queue *q, void *a) 153 { 154 struct frag_queue *fq = container_of(q, struct frag_queue, q); 155 struct ip6_create_arg *arg = a; 156 157 fq->id = arg->id; 158 fq->user = arg->user; 159 ipv6_addr_copy(&fq->saddr, arg->src); 160 ipv6_addr_copy(&fq->daddr, arg->dst); 161 } 162 EXPORT_SYMBOL(ip6_frag_init); 163 164 /* Destruction primitives. */ 165 166 static __inline__ void fq_put(struct frag_queue *fq) 167 { 168 inet_frag_put(&fq->q, &ip6_frags); 169 } 170 171 /* Kill fq entry. It is not destroyed immediately, 172 * because caller (and someone more) holds reference count. 173 */ 174 static __inline__ void fq_kill(struct frag_queue *fq) 175 { 176 inet_frag_kill(&fq->q, &ip6_frags); 177 } 178 179 static void ip6_evictor(struct net *net, struct inet6_dev *idev) 180 { 181 int evicted; 182 183 evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags); 184 if (evicted) 185 IP6_ADD_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS, evicted); 186 } 187 188 static void ip6_frag_expire(unsigned long data) 189 { 190 struct frag_queue *fq; 191 struct net_device *dev = NULL; 192 struct net *net; 193 194 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); 195 196 spin_lock(&fq->q.lock); 197 198 if (fq->q.last_in & INET_FRAG_COMPLETE) 199 goto out; 200 201 fq_kill(fq); 202 203 net = container_of(fq->q.net, struct net, ipv6.frags); 204 rcu_read_lock(); 205 dev = dev_get_by_index_rcu(net, fq->iif); 206 if (!dev) 207 goto out_rcu_unlock; 208 209 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); 210 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 211 212 /* Don't send error if the first segment did not arrive. */ 213 if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments) 214 goto out_rcu_unlock; 215 216 /* 217 But use as source device on which LAST ARRIVED 218 segment was received. And do not use fq->dev 219 pointer directly, device might already disappeared. 220 */ 221 fq->q.fragments->dev = dev; 222 icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); 223 out_rcu_unlock: 224 rcu_read_unlock(); 225 out: 226 spin_unlock(&fq->q.lock); 227 fq_put(fq); 228 } 229 230 static __inline__ struct frag_queue * 231 fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst) 232 { 233 struct inet_frag_queue *q; 234 struct ip6_create_arg arg; 235 unsigned int hash; 236 237 arg.id = id; 238 arg.user = IP6_DEFRAG_LOCAL_DELIVER; 239 arg.src = src; 240 arg.dst = dst; 241 242 read_lock(&ip6_frags.lock); 243 hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd); 244 245 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); 246 if (q == NULL) 247 return NULL; 248 249 return container_of(q, struct frag_queue, q); 250 } 251 252 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, 253 struct frag_hdr *fhdr, int nhoff) 254 { 255 struct sk_buff *prev, *next; 256 struct net_device *dev; 257 int offset, end; 258 struct net *net = dev_net(skb_dst(skb)->dev); 259 260 if (fq->q.last_in & INET_FRAG_COMPLETE) 261 goto err; 262 263 offset = ntohs(fhdr->frag_off) & ~0x7; 264 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - 265 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); 266 267 if ((unsigned int)end > IPV6_MAXPLEN) { 268 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 269 IPSTATS_MIB_INHDRERRORS); 270 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 271 ((u8 *)&fhdr->frag_off - 272 skb_network_header(skb))); 273 return -1; 274 } 275 276 if (skb->ip_summed == CHECKSUM_COMPLETE) { 277 const unsigned char *nh = skb_network_header(skb); 278 skb->csum = csum_sub(skb->csum, 279 csum_partial(nh, (u8 *)(fhdr + 1) - nh, 280 0)); 281 } 282 283 /* Is this the final fragment? */ 284 if (!(fhdr->frag_off & htons(IP6_MF))) { 285 /* If we already have some bits beyond end 286 * or have different end, the segment is corrupted. 287 */ 288 if (end < fq->q.len || 289 ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) 290 goto err; 291 fq->q.last_in |= INET_FRAG_LAST_IN; 292 fq->q.len = end; 293 } else { 294 /* Check if the fragment is rounded to 8 bytes. 295 * Required by the RFC. 296 */ 297 if (end & 0x7) { 298 /* RFC2460 says always send parameter problem in 299 * this case. -DaveM 300 */ 301 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 302 IPSTATS_MIB_INHDRERRORS); 303 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 304 offsetof(struct ipv6hdr, payload_len)); 305 return -1; 306 } 307 if (end > fq->q.len) { 308 /* Some bits beyond end -> corruption. */ 309 if (fq->q.last_in & INET_FRAG_LAST_IN) 310 goto err; 311 fq->q.len = end; 312 } 313 } 314 315 if (end == offset) 316 goto err; 317 318 /* Point into the IP datagram 'data' part. */ 319 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) 320 goto err; 321 322 if (pskb_trim_rcsum(skb, end - offset)) 323 goto err; 324 325 /* Find out which fragments are in front and at the back of us 326 * in the chain of fragments so far. We must know where to put 327 * this fragment, right? 328 */ 329 prev = fq->q.fragments_tail; 330 if (!prev || FRAG6_CB(prev)->offset < offset) { 331 next = NULL; 332 goto found; 333 } 334 prev = NULL; 335 for(next = fq->q.fragments; next != NULL; next = next->next) { 336 if (FRAG6_CB(next)->offset >= offset) 337 break; /* bingo! */ 338 prev = next; 339 } 340 341 found: 342 /* RFC5722, Section 4: 343 * When reassembling an IPv6 datagram, if 344 * one or more its constituent fragments is determined to be an 345 * overlapping fragment, the entire datagram (and any constituent 346 * fragments, including those not yet received) MUST be silently 347 * discarded. 348 */ 349 350 /* Check for overlap with preceding fragment. */ 351 if (prev && 352 (FRAG6_CB(prev)->offset + prev->len) - offset > 0) 353 goto discard_fq; 354 355 /* Look for overlap with succeeding segment. */ 356 if (next && FRAG6_CB(next)->offset < end) 357 goto discard_fq; 358 359 FRAG6_CB(skb)->offset = offset; 360 361 /* Insert this fragment in the chain of fragments. */ 362 skb->next = next; 363 if (!next) 364 fq->q.fragments_tail = skb; 365 if (prev) 366 prev->next = skb; 367 else 368 fq->q.fragments = skb; 369 370 dev = skb->dev; 371 if (dev) { 372 fq->iif = dev->ifindex; 373 skb->dev = NULL; 374 } 375 fq->q.stamp = skb->tstamp; 376 fq->q.meat += skb->len; 377 atomic_add(skb->truesize, &fq->q.net->mem); 378 379 /* The first fragment. 380 * nhoffset is obtained from the first fragment, of course. 381 */ 382 if (offset == 0) { 383 fq->nhoffset = nhoff; 384 fq->q.last_in |= INET_FRAG_FIRST_IN; 385 } 386 387 if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 388 fq->q.meat == fq->q.len) 389 return ip6_frag_reasm(fq, prev, dev); 390 391 write_lock(&ip6_frags.lock); 392 list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list); 393 write_unlock(&ip6_frags.lock); 394 return -1; 395 396 discard_fq: 397 fq_kill(fq); 398 err: 399 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 400 IPSTATS_MIB_REASMFAILS); 401 kfree_skb(skb); 402 return -1; 403 } 404 405 /* 406 * Check if this packet is complete. 407 * Returns NULL on failure by any reason, and pointer 408 * to current nexthdr field in reassembled frame. 409 * 410 * It is called with locked fq, and caller must check that 411 * queue is eligible for reassembly i.e. it is not COMPLETE, 412 * the last and the first frames arrived and all the bits are here. 413 */ 414 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 415 struct net_device *dev) 416 { 417 struct net *net = container_of(fq->q.net, struct net, ipv6.frags); 418 struct sk_buff *fp, *head = fq->q.fragments; 419 int payload_len; 420 unsigned int nhoff; 421 422 fq_kill(fq); 423 424 /* Make the one we just received the head. */ 425 if (prev) { 426 head = prev->next; 427 fp = skb_clone(head, GFP_ATOMIC); 428 429 if (!fp) 430 goto out_oom; 431 432 fp->next = head->next; 433 if (!fp->next) 434 fq->q.fragments_tail = fp; 435 prev->next = fp; 436 437 skb_morph(head, fq->q.fragments); 438 head->next = fq->q.fragments->next; 439 440 kfree_skb(fq->q.fragments); 441 fq->q.fragments = head; 442 } 443 444 WARN_ON(head == NULL); 445 WARN_ON(FRAG6_CB(head)->offset != 0); 446 447 /* Unfragmented part is taken from the first segment. */ 448 payload_len = ((head->data - skb_network_header(head)) - 449 sizeof(struct ipv6hdr) + fq->q.len - 450 sizeof(struct frag_hdr)); 451 if (payload_len > IPV6_MAXPLEN) 452 goto out_oversize; 453 454 /* Head of list must not be cloned. */ 455 if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) 456 goto out_oom; 457 458 /* If the first fragment is fragmented itself, we split 459 * it to two chunks: the first with data and paged part 460 * and the second, holding only fragments. */ 461 if (skb_has_frag_list(head)) { 462 struct sk_buff *clone; 463 int i, plen = 0; 464 465 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) 466 goto out_oom; 467 clone->next = head->next; 468 head->next = clone; 469 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 470 skb_frag_list_init(head); 471 for (i=0; i<skb_shinfo(head)->nr_frags; i++) 472 plen += skb_shinfo(head)->frags[i].size; 473 clone->len = clone->data_len = head->data_len - plen; 474 head->data_len -= clone->len; 475 head->len -= clone->len; 476 clone->csum = 0; 477 clone->ip_summed = head->ip_summed; 478 atomic_add(clone->truesize, &fq->q.net->mem); 479 } 480 481 /* We have to remove fragment header from datagram and to relocate 482 * header in order to calculate ICV correctly. */ 483 nhoff = fq->nhoffset; 484 skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; 485 memmove(head->head + sizeof(struct frag_hdr), head->head, 486 (head->data - head->head) - sizeof(struct frag_hdr)); 487 head->mac_header += sizeof(struct frag_hdr); 488 head->network_header += sizeof(struct frag_hdr); 489 490 skb_shinfo(head)->frag_list = head->next; 491 skb_reset_transport_header(head); 492 skb_push(head, head->data - skb_network_header(head)); 493 494 for (fp=head->next; fp; fp = fp->next) { 495 head->data_len += fp->len; 496 head->len += fp->len; 497 if (head->ip_summed != fp->ip_summed) 498 head->ip_summed = CHECKSUM_NONE; 499 else if (head->ip_summed == CHECKSUM_COMPLETE) 500 head->csum = csum_add(head->csum, fp->csum); 501 head->truesize += fp->truesize; 502 } 503 atomic_sub(head->truesize, &fq->q.net->mem); 504 505 head->next = NULL; 506 head->dev = dev; 507 head->tstamp = fq->q.stamp; 508 ipv6_hdr(head)->payload_len = htons(payload_len); 509 IP6CB(head)->nhoff = nhoff; 510 511 /* Yes, and fold redundant checksum back. 8) */ 512 if (head->ip_summed == CHECKSUM_COMPLETE) 513 head->csum = csum_partial(skb_network_header(head), 514 skb_network_header_len(head), 515 head->csum); 516 517 rcu_read_lock(); 518 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); 519 rcu_read_unlock(); 520 fq->q.fragments = NULL; 521 fq->q.fragments_tail = NULL; 522 return 1; 523 524 out_oversize: 525 if (net_ratelimit()) 526 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len); 527 goto out_fail; 528 out_oom: 529 if (net_ratelimit()) 530 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n"); 531 out_fail: 532 rcu_read_lock(); 533 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 534 rcu_read_unlock(); 535 return -1; 536 } 537 538 static int ipv6_frag_rcv(struct sk_buff *skb) 539 { 540 struct frag_hdr *fhdr; 541 struct frag_queue *fq; 542 struct ipv6hdr *hdr = ipv6_hdr(skb); 543 struct net *net = dev_net(skb_dst(skb)->dev); 544 545 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); 546 547 /* Jumbo payload inhibits frag. header */ 548 if (hdr->payload_len==0) 549 goto fail_hdr; 550 551 if (!pskb_may_pull(skb, (skb_transport_offset(skb) + 552 sizeof(struct frag_hdr)))) 553 goto fail_hdr; 554 555 hdr = ipv6_hdr(skb); 556 fhdr = (struct frag_hdr *)skb_transport_header(skb); 557 558 if (!(fhdr->frag_off & htons(0xFFF9))) { 559 /* It is not a fragmented frame */ 560 skb->transport_header += sizeof(struct frag_hdr); 561 IP6_INC_STATS_BH(net, 562 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); 563 564 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); 565 return 1; 566 } 567 568 if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh) 569 ip6_evictor(net, ip6_dst_idev(skb_dst(skb))); 570 571 fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr); 572 if (fq != NULL) { 573 int ret; 574 575 spin_lock(&fq->q.lock); 576 577 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); 578 579 spin_unlock(&fq->q.lock); 580 fq_put(fq); 581 return ret; 582 } 583 584 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); 585 kfree_skb(skb); 586 return -1; 587 588 fail_hdr: 589 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); 590 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); 591 return -1; 592 } 593 594 static const struct inet6_protocol frag_protocol = 595 { 596 .handler = ipv6_frag_rcv, 597 .flags = INET6_PROTO_NOPOLICY, 598 }; 599 600 #ifdef CONFIG_SYSCTL 601 static struct ctl_table ip6_frags_ns_ctl_table[] = { 602 { 603 .procname = "ip6frag_high_thresh", 604 .data = &init_net.ipv6.frags.high_thresh, 605 .maxlen = sizeof(int), 606 .mode = 0644, 607 .proc_handler = proc_dointvec 608 }, 609 { 610 .procname = "ip6frag_low_thresh", 611 .data = &init_net.ipv6.frags.low_thresh, 612 .maxlen = sizeof(int), 613 .mode = 0644, 614 .proc_handler = proc_dointvec 615 }, 616 { 617 .procname = "ip6frag_time", 618 .data = &init_net.ipv6.frags.timeout, 619 .maxlen = sizeof(int), 620 .mode = 0644, 621 .proc_handler = proc_dointvec_jiffies, 622 }, 623 { } 624 }; 625 626 static struct ctl_table ip6_frags_ctl_table[] = { 627 { 628 .procname = "ip6frag_secret_interval", 629 .data = &ip6_frags.secret_interval, 630 .maxlen = sizeof(int), 631 .mode = 0644, 632 .proc_handler = proc_dointvec_jiffies, 633 }, 634 { } 635 }; 636 637 static int __net_init ip6_frags_ns_sysctl_register(struct net *net) 638 { 639 struct ctl_table *table; 640 struct ctl_table_header *hdr; 641 642 table = ip6_frags_ns_ctl_table; 643 if (!net_eq(net, &init_net)) { 644 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); 645 if (table == NULL) 646 goto err_alloc; 647 648 table[0].data = &net->ipv6.frags.high_thresh; 649 table[1].data = &net->ipv6.frags.low_thresh; 650 table[2].data = &net->ipv6.frags.timeout; 651 } 652 653 hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table); 654 if (hdr == NULL) 655 goto err_reg; 656 657 net->ipv6.sysctl.frags_hdr = hdr; 658 return 0; 659 660 err_reg: 661 if (!net_eq(net, &init_net)) 662 kfree(table); 663 err_alloc: 664 return -ENOMEM; 665 } 666 667 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) 668 { 669 struct ctl_table *table; 670 671 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; 672 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); 673 if (!net_eq(net, &init_net)) 674 kfree(table); 675 } 676 677 static struct ctl_table_header *ip6_ctl_header; 678 679 static int ip6_frags_sysctl_register(void) 680 { 681 ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path, 682 ip6_frags_ctl_table); 683 return ip6_ctl_header == NULL ? -ENOMEM : 0; 684 } 685 686 static void ip6_frags_sysctl_unregister(void) 687 { 688 unregister_net_sysctl_table(ip6_ctl_header); 689 } 690 #else 691 static inline int ip6_frags_ns_sysctl_register(struct net *net) 692 { 693 return 0; 694 } 695 696 static inline void ip6_frags_ns_sysctl_unregister(struct net *net) 697 { 698 } 699 700 static inline int ip6_frags_sysctl_register(void) 701 { 702 return 0; 703 } 704 705 static inline void ip6_frags_sysctl_unregister(void) 706 { 707 } 708 #endif 709 710 static int __net_init ipv6_frags_init_net(struct net *net) 711 { 712 net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; 713 net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; 714 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; 715 716 inet_frags_init_net(&net->ipv6.frags); 717 718 return ip6_frags_ns_sysctl_register(net); 719 } 720 721 static void __net_exit ipv6_frags_exit_net(struct net *net) 722 { 723 ip6_frags_ns_sysctl_unregister(net); 724 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); 725 } 726 727 static struct pernet_operations ip6_frags_ops = { 728 .init = ipv6_frags_init_net, 729 .exit = ipv6_frags_exit_net, 730 }; 731 732 int __init ipv6_frag_init(void) 733 { 734 int ret; 735 736 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); 737 if (ret) 738 goto out; 739 740 ret = ip6_frags_sysctl_register(); 741 if (ret) 742 goto err_sysctl; 743 744 ret = register_pernet_subsys(&ip6_frags_ops); 745 if (ret) 746 goto err_pernet; 747 748 ip6_frags.hashfn = ip6_hashfn; 749 ip6_frags.constructor = ip6_frag_init; 750 ip6_frags.destructor = NULL; 751 ip6_frags.skb_free = NULL; 752 ip6_frags.qsize = sizeof(struct frag_queue); 753 ip6_frags.match = ip6_frag_match; 754 ip6_frags.frag_expire = ip6_frag_expire; 755 ip6_frags.secret_interval = 10 * 60 * HZ; 756 inet_frags_init(&ip6_frags); 757 out: 758 return ret; 759 760 err_pernet: 761 ip6_frags_sysctl_unregister(); 762 err_sysctl: 763 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 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