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 struct ip6frag_skb_cb { 66 struct inet6_skb_parm h; 67 int offset; 68 }; 69 70 #define FRAG6_CB(skb) ((struct ip6frag_skb_cb *)((skb)->cb)) 71 72 static u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h) 73 { 74 return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK); 75 } 76 77 static struct inet_frags ip6_frags; 78 79 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 80 struct net_device *dev); 81 82 /* 83 * callers should be careful not to use the hash value outside the ipfrag_lock 84 * as doing so could race with ipfrag_hash_rnd being recalculated. 85 */ 86 static unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, 87 const struct in6_addr *daddr) 88 { 89 net_get_random_once(&ip6_frags.rnd, sizeof(ip6_frags.rnd)); 90 return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), 91 (__force u32)id, ip6_frags.rnd); 92 } 93 94 static unsigned int ip6_hashfn(const struct inet_frag_queue *q) 95 { 96 const struct frag_queue *fq; 97 98 fq = container_of(q, struct frag_queue, q); 99 return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr); 100 } 101 102 bool ip6_frag_match(const struct inet_frag_queue *q, const void *a) 103 { 104 const struct frag_queue *fq; 105 const struct ip6_create_arg *arg = a; 106 107 fq = container_of(q, struct frag_queue, q); 108 return fq->id == arg->id && 109 fq->user == arg->user && 110 ipv6_addr_equal(&fq->saddr, arg->src) && 111 ipv6_addr_equal(&fq->daddr, arg->dst) && 112 (arg->iif == fq->iif || 113 !(ipv6_addr_type(arg->dst) & (IPV6_ADDR_MULTICAST | 114 IPV6_ADDR_LINKLOCAL))); 115 } 116 EXPORT_SYMBOL(ip6_frag_match); 117 118 void ip6_frag_init(struct inet_frag_queue *q, const void *a) 119 { 120 struct frag_queue *fq = container_of(q, struct frag_queue, q); 121 const struct ip6_create_arg *arg = a; 122 123 fq->id = arg->id; 124 fq->user = arg->user; 125 fq->saddr = *arg->src; 126 fq->daddr = *arg->dst; 127 fq->ecn = arg->ecn; 128 } 129 EXPORT_SYMBOL(ip6_frag_init); 130 131 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq, 132 struct inet_frags *frags) 133 { 134 struct net_device *dev = NULL; 135 136 spin_lock(&fq->q.lock); 137 138 if (fq->q.flags & INET_FRAG_COMPLETE) 139 goto out; 140 141 inet_frag_kill(&fq->q, frags); 142 143 rcu_read_lock(); 144 dev = dev_get_by_index_rcu(net, fq->iif); 145 if (!dev) 146 goto out_rcu_unlock; 147 148 __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 149 150 if (inet_frag_evicting(&fq->q)) 151 goto out_rcu_unlock; 152 153 __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); 154 155 /* Don't send error if the first segment did not arrive. */ 156 if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !fq->q.fragments) 157 goto out_rcu_unlock; 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(struct timer_list *t) 174 { 175 struct inet_frag_queue *frag = from_timer(frag, t, timer); 176 struct frag_queue *fq; 177 struct net *net; 178 179 fq = container_of(frag, struct frag_queue, q); 180 net = container_of(fq->q.net, struct net, ipv6.frags); 181 182 ip6_expire_frag_queue(net, fq, &ip6_frags); 183 } 184 185 static struct frag_queue * 186 fq_find(struct net *net, __be32 id, const struct in6_addr *src, 187 const struct in6_addr *dst, int iif, u8 ecn) 188 { 189 struct inet_frag_queue *q; 190 struct ip6_create_arg arg; 191 unsigned int hash; 192 193 arg.id = id; 194 arg.user = IP6_DEFRAG_LOCAL_DELIVER; 195 arg.src = src; 196 arg.dst = dst; 197 arg.iif = iif; 198 arg.ecn = ecn; 199 200 hash = inet6_hash_frag(id, src, dst); 201 202 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); 203 if (IS_ERR_OR_NULL(q)) { 204 inet_frag_maybe_warn_overflow(q, pr_fmt()); 205 return NULL; 206 } 207 return container_of(q, struct frag_queue, q); 208 } 209 210 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, 211 struct frag_hdr *fhdr, int nhoff) 212 { 213 struct sk_buff *prev, *next; 214 struct net_device *dev; 215 int offset, end, fragsize; 216 struct net *net = dev_net(skb_dst(skb)->dev); 217 u8 ecn; 218 219 if (fq->q.flags & INET_FRAG_COMPLETE) 220 goto err; 221 222 offset = ntohs(fhdr->frag_off) & ~0x7; 223 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - 224 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); 225 226 if ((unsigned int)end > IPV6_MAXPLEN) { 227 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 228 IPSTATS_MIB_INHDRERRORS); 229 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 230 ((u8 *)&fhdr->frag_off - 231 skb_network_header(skb))); 232 return -1; 233 } 234 235 ecn = ip6_frag_ecn(ipv6_hdr(skb)); 236 237 if (skb->ip_summed == CHECKSUM_COMPLETE) { 238 const unsigned char *nh = skb_network_header(skb); 239 skb->csum = csum_sub(skb->csum, 240 csum_partial(nh, (u8 *)(fhdr + 1) - nh, 241 0)); 242 } 243 244 /* Is this the final fragment? */ 245 if (!(fhdr->frag_off & htons(IP6_MF))) { 246 /* If we already have some bits beyond end 247 * or have different end, the segment is corrupted. 248 */ 249 if (end < fq->q.len || 250 ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len)) 251 goto err; 252 fq->q.flags |= INET_FRAG_LAST_IN; 253 fq->q.len = end; 254 } else { 255 /* Check if the fragment is rounded to 8 bytes. 256 * Required by the RFC. 257 */ 258 if (end & 0x7) { 259 /* RFC2460 says always send parameter problem in 260 * this case. -DaveM 261 */ 262 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 263 IPSTATS_MIB_INHDRERRORS); 264 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 265 offsetof(struct ipv6hdr, payload_len)); 266 return -1; 267 } 268 if (end > fq->q.len) { 269 /* Some bits beyond end -> corruption. */ 270 if (fq->q.flags & INET_FRAG_LAST_IN) 271 goto err; 272 fq->q.len = end; 273 } 274 } 275 276 if (end == offset) 277 goto err; 278 279 /* Point into the IP datagram 'data' part. */ 280 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) 281 goto err; 282 283 if (pskb_trim_rcsum(skb, end - offset)) 284 goto err; 285 286 /* Find out which fragments are in front and at the back of us 287 * in the chain of fragments so far. We must know where to put 288 * this fragment, right? 289 */ 290 prev = fq->q.fragments_tail; 291 if (!prev || FRAG6_CB(prev)->offset < offset) { 292 next = NULL; 293 goto found; 294 } 295 prev = NULL; 296 for (next = fq->q.fragments; next != NULL; next = next->next) { 297 if (FRAG6_CB(next)->offset >= offset) 298 break; /* bingo! */ 299 prev = next; 300 } 301 302 found: 303 /* RFC5722, Section 4, amended by Errata ID : 3089 304 * When reassembling an IPv6 datagram, if 305 * one or more its constituent fragments is determined to be an 306 * overlapping fragment, the entire datagram (and any constituent 307 * fragments) MUST be silently discarded. 308 */ 309 310 /* Check for overlap with preceding fragment. */ 311 if (prev && 312 (FRAG6_CB(prev)->offset + prev->len) > offset) 313 goto discard_fq; 314 315 /* Look for overlap with succeeding segment. */ 316 if (next && FRAG6_CB(next)->offset < end) 317 goto discard_fq; 318 319 FRAG6_CB(skb)->offset = offset; 320 321 /* Insert this fragment in the chain of fragments. */ 322 skb->next = next; 323 if (!next) 324 fq->q.fragments_tail = skb; 325 if (prev) 326 prev->next = skb; 327 else 328 fq->q.fragments = skb; 329 330 dev = skb->dev; 331 if (dev) { 332 fq->iif = dev->ifindex; 333 skb->dev = NULL; 334 } 335 fq->q.stamp = skb->tstamp; 336 fq->q.meat += skb->len; 337 fq->ecn |= ecn; 338 add_frag_mem_limit(fq->q.net, skb->truesize); 339 340 fragsize = -skb_network_offset(skb) + skb->len; 341 if (fragsize > fq->q.max_size) 342 fq->q.max_size = fragsize; 343 344 /* The first fragment. 345 * nhoffset is obtained from the first fragment, of course. 346 */ 347 if (offset == 0) { 348 fq->nhoffset = nhoff; 349 fq->q.flags |= INET_FRAG_FIRST_IN; 350 } 351 352 if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 353 fq->q.meat == fq->q.len) { 354 int res; 355 unsigned long orefdst = skb->_skb_refdst; 356 357 skb->_skb_refdst = 0UL; 358 res = ip6_frag_reasm(fq, prev, dev); 359 skb->_skb_refdst = orefdst; 360 return res; 361 } 362 363 skb_dst_drop(skb); 364 return -1; 365 366 discard_fq: 367 inet_frag_kill(&fq->q, &ip6_frags); 368 err: 369 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 370 IPSTATS_MIB_REASMFAILS); 371 kfree_skb(skb); 372 return -1; 373 } 374 375 /* 376 * Check if this packet is complete. 377 * Returns NULL on failure by any reason, and pointer 378 * to current nexthdr field in reassembled frame. 379 * 380 * It is called with locked fq, and caller must check that 381 * queue is eligible for reassembly i.e. it is not COMPLETE, 382 * the last and the first frames arrived and all the bits are here. 383 */ 384 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 385 struct net_device *dev) 386 { 387 struct net *net = container_of(fq->q.net, struct net, ipv6.frags); 388 struct sk_buff *fp, *head = fq->q.fragments; 389 int payload_len; 390 unsigned int nhoff; 391 int sum_truesize; 392 u8 ecn; 393 394 inet_frag_kill(&fq->q, &ip6_frags); 395 396 ecn = ip_frag_ecn_table[fq->ecn]; 397 if (unlikely(ecn == 0xff)) 398 goto out_fail; 399 400 /* Make the one we just received the head. */ 401 if (prev) { 402 head = prev->next; 403 fp = skb_clone(head, GFP_ATOMIC); 404 405 if (!fp) 406 goto out_oom; 407 408 fp->next = head->next; 409 if (!fp->next) 410 fq->q.fragments_tail = fp; 411 prev->next = fp; 412 413 skb_morph(head, fq->q.fragments); 414 head->next = fq->q.fragments->next; 415 416 consume_skb(fq->q.fragments); 417 fq->q.fragments = head; 418 } 419 420 WARN_ON(head == NULL); 421 WARN_ON(FRAG6_CB(head)->offset != 0); 422 423 /* Unfragmented part is taken from the first segment. */ 424 payload_len = ((head->data - skb_network_header(head)) - 425 sizeof(struct ipv6hdr) + fq->q.len - 426 sizeof(struct frag_hdr)); 427 if (payload_len > IPV6_MAXPLEN) 428 goto out_oversize; 429 430 /* Head of list must not be cloned. */ 431 if (skb_unclone(head, GFP_ATOMIC)) 432 goto out_oom; 433 434 /* If the first fragment is fragmented itself, we split 435 * it to two chunks: the first with data and paged part 436 * and the second, holding only fragments. */ 437 if (skb_has_frag_list(head)) { 438 struct sk_buff *clone; 439 int i, plen = 0; 440 441 clone = alloc_skb(0, GFP_ATOMIC); 442 if (!clone) 443 goto out_oom; 444 clone->next = head->next; 445 head->next = clone; 446 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 447 skb_frag_list_init(head); 448 for (i = 0; i < skb_shinfo(head)->nr_frags; i++) 449 plen += skb_frag_size(&skb_shinfo(head)->frags[i]); 450 clone->len = clone->data_len = head->data_len - plen; 451 head->data_len -= clone->len; 452 head->len -= clone->len; 453 clone->csum = 0; 454 clone->ip_summed = head->ip_summed; 455 add_frag_mem_limit(fq->q.net, clone->truesize); 456 } 457 458 /* We have to remove fragment header from datagram and to relocate 459 * header in order to calculate ICV correctly. */ 460 nhoff = fq->nhoffset; 461 skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; 462 memmove(head->head + sizeof(struct frag_hdr), head->head, 463 (head->data - head->head) - sizeof(struct frag_hdr)); 464 if (skb_mac_header_was_set(head)) 465 head->mac_header += sizeof(struct frag_hdr); 466 head->network_header += sizeof(struct frag_hdr); 467 468 skb_reset_transport_header(head); 469 skb_push(head, head->data - skb_network_header(head)); 470 471 sum_truesize = head->truesize; 472 for (fp = head->next; fp;) { 473 bool headstolen; 474 int delta; 475 struct sk_buff *next = fp->next; 476 477 sum_truesize += fp->truesize; 478 if (head->ip_summed != fp->ip_summed) 479 head->ip_summed = CHECKSUM_NONE; 480 else if (head->ip_summed == CHECKSUM_COMPLETE) 481 head->csum = csum_add(head->csum, fp->csum); 482 483 if (skb_try_coalesce(head, fp, &headstolen, &delta)) { 484 kfree_skb_partial(fp, headstolen); 485 } else { 486 if (!skb_shinfo(head)->frag_list) 487 skb_shinfo(head)->frag_list = fp; 488 head->data_len += fp->len; 489 head->len += fp->len; 490 head->truesize += fp->truesize; 491 } 492 fp = next; 493 } 494 sub_frag_mem_limit(fq->q.net, sum_truesize); 495 496 head->next = NULL; 497 head->dev = dev; 498 head->tstamp = fq->q.stamp; 499 ipv6_hdr(head)->payload_len = htons(payload_len); 500 ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); 501 IP6CB(head)->nhoff = nhoff; 502 IP6CB(head)->flags |= IP6SKB_FRAGMENTED; 503 IP6CB(head)->frag_max_size = fq->q.max_size; 504 505 /* Yes, and fold redundant checksum back. 8) */ 506 skb_postpush_rcsum(head, skb_network_header(head), 507 skb_network_header_len(head)); 508 509 rcu_read_lock(); 510 __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); 511 rcu_read_unlock(); 512 fq->q.fragments = NULL; 513 fq->q.fragments_tail = NULL; 514 return 1; 515 516 out_oversize: 517 net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); 518 goto out_fail; 519 out_oom: 520 net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); 521 out_fail: 522 rcu_read_lock(); 523 __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 524 rcu_read_unlock(); 525 return -1; 526 } 527 528 static int ipv6_frag_rcv(struct sk_buff *skb) 529 { 530 struct frag_hdr *fhdr; 531 struct frag_queue *fq; 532 const struct ipv6hdr *hdr = ipv6_hdr(skb); 533 struct net *net = dev_net(skb_dst(skb)->dev); 534 535 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED) 536 goto fail_hdr; 537 538 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); 539 540 /* Jumbo payload inhibits frag. header */ 541 if (hdr->payload_len == 0) 542 goto fail_hdr; 543 544 if (!pskb_may_pull(skb, (skb_transport_offset(skb) + 545 sizeof(struct frag_hdr)))) 546 goto fail_hdr; 547 548 hdr = ipv6_hdr(skb); 549 fhdr = (struct frag_hdr *)skb_transport_header(skb); 550 551 if (!(fhdr->frag_off & htons(0xFFF9))) { 552 /* It is not a fragmented frame */ 553 skb->transport_header += sizeof(struct frag_hdr); 554 __IP6_INC_STATS(net, 555 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); 556 557 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); 558 IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; 559 return 1; 560 } 561 562 fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, 563 skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr)); 564 if (fq) { 565 int ret; 566 567 spin_lock(&fq->q.lock); 568 569 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); 570 571 spin_unlock(&fq->q.lock); 572 inet_frag_put(&fq->q, &ip6_frags); 573 return ret; 574 } 575 576 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); 577 kfree_skb(skb); 578 return -1; 579 580 fail_hdr: 581 __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 582 IPSTATS_MIB_INHDRERRORS); 583 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); 584 return -1; 585 } 586 587 static const struct inet6_protocol frag_protocol = { 588 .handler = ipv6_frag_rcv, 589 .flags = INET6_PROTO_NOPOLICY, 590 }; 591 592 #ifdef CONFIG_SYSCTL 593 static int zero; 594 595 static struct ctl_table ip6_frags_ns_ctl_table[] = { 596 { 597 .procname = "ip6frag_high_thresh", 598 .data = &init_net.ipv6.frags.high_thresh, 599 .maxlen = sizeof(int), 600 .mode = 0644, 601 .proc_handler = proc_dointvec_minmax, 602 .extra1 = &init_net.ipv6.frags.low_thresh 603 }, 604 { 605 .procname = "ip6frag_low_thresh", 606 .data = &init_net.ipv6.frags.low_thresh, 607 .maxlen = sizeof(int), 608 .mode = 0644, 609 .proc_handler = proc_dointvec_minmax, 610 .extra1 = &zero, 611 .extra2 = &init_net.ipv6.frags.high_thresh 612 }, 613 { 614 .procname = "ip6frag_time", 615 .data = &init_net.ipv6.frags.timeout, 616 .maxlen = sizeof(int), 617 .mode = 0644, 618 .proc_handler = proc_dointvec_jiffies, 619 }, 620 { } 621 }; 622 623 /* secret interval has been deprecated */ 624 static int ip6_frags_secret_interval_unused; 625 static struct ctl_table ip6_frags_ctl_table[] = { 626 { 627 .procname = "ip6frag_secret_interval", 628 .data = &ip6_frags_secret_interval_unused, 629 .maxlen = sizeof(int), 630 .mode = 0644, 631 .proc_handler = proc_dointvec_jiffies, 632 }, 633 { } 634 }; 635 636 static int __net_init ip6_frags_ns_sysctl_register(struct net *net) 637 { 638 struct ctl_table *table; 639 struct ctl_table_header *hdr; 640 641 table = ip6_frags_ns_ctl_table; 642 if (!net_eq(net, &init_net)) { 643 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); 644 if (!table) 645 goto err_alloc; 646 647 table[0].data = &net->ipv6.frags.high_thresh; 648 table[0].extra1 = &net->ipv6.frags.low_thresh; 649 table[0].extra2 = &init_net.ipv6.frags.high_thresh; 650 table[1].data = &net->ipv6.frags.low_thresh; 651 table[1].extra2 = &net->ipv6.frags.high_thresh; 652 table[2].data = &net->ipv6.frags.timeout; 653 654 /* Don't export sysctls to unprivileged users */ 655 if (net->user_ns != &init_user_ns) 656 table[0].procname = NULL; 657 } 658 659 hdr = register_net_sysctl(net, "net/ipv6", table); 660 if (!hdr) 661 goto err_reg; 662 663 net->ipv6.sysctl.frags_hdr = hdr; 664 return 0; 665 666 err_reg: 667 if (!net_eq(net, &init_net)) 668 kfree(table); 669 err_alloc: 670 return -ENOMEM; 671 } 672 673 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) 674 { 675 struct ctl_table *table; 676 677 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; 678 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); 679 if (!net_eq(net, &init_net)) 680 kfree(table); 681 } 682 683 static struct ctl_table_header *ip6_ctl_header; 684 685 static int ip6_frags_sysctl_register(void) 686 { 687 ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", 688 ip6_frags_ctl_table); 689 return ip6_ctl_header == NULL ? -ENOMEM : 0; 690 } 691 692 static void ip6_frags_sysctl_unregister(void) 693 { 694 unregister_net_sysctl_table(ip6_ctl_header); 695 } 696 #else 697 static int ip6_frags_ns_sysctl_register(struct net *net) 698 { 699 return 0; 700 } 701 702 static void ip6_frags_ns_sysctl_unregister(struct net *net) 703 { 704 } 705 706 static int ip6_frags_sysctl_register(void) 707 { 708 return 0; 709 } 710 711 static void ip6_frags_sysctl_unregister(void) 712 { 713 } 714 #endif 715 716 static int __net_init ipv6_frags_init_net(struct net *net) 717 { 718 net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; 719 net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; 720 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; 721 722 inet_frags_init_net(&net->ipv6.frags); 723 724 return ip6_frags_ns_sysctl_register(net); 725 } 726 727 static void __net_exit ipv6_frags_exit_net(struct net *net) 728 { 729 ip6_frags_ns_sysctl_unregister(net); 730 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); 731 } 732 733 static struct pernet_operations ip6_frags_ops = { 734 .init = ipv6_frags_init_net, 735 .exit = ipv6_frags_exit_net, 736 }; 737 738 int __init ipv6_frag_init(void) 739 { 740 int ret; 741 742 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); 743 if (ret) 744 goto out; 745 746 ret = ip6_frags_sysctl_register(); 747 if (ret) 748 goto err_sysctl; 749 750 ret = register_pernet_subsys(&ip6_frags_ops); 751 if (ret) 752 goto err_pernet; 753 754 ip6_frags.hashfn = ip6_hashfn; 755 ip6_frags.constructor = ip6_frag_init; 756 ip6_frags.destructor = NULL; 757 ip6_frags.qsize = sizeof(struct frag_queue); 758 ip6_frags.match = ip6_frag_match; 759 ip6_frags.frag_expire = ip6_frag_expire; 760 ip6_frags.frags_cache_name = ip6_frag_cache_name; 761 ret = inet_frags_init(&ip6_frags); 762 if (ret) 763 goto err_pernet; 764 out: 765 return ret; 766 767 err_pernet: 768 ip6_frags_sysctl_unregister(); 769 err_sysctl: 770 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 771 goto out; 772 } 773 774 void ipv6_frag_exit(void) 775 { 776 inet_frags_fini(&ip6_frags); 777 ip6_frags_sysctl_unregister(); 778 unregister_pernet_subsys(&ip6_frags_ops); 779 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 780 } 781