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 struct ip6frag_skb_cb 64 { 65 struct inet6_skb_parm h; 66 int offset; 67 }; 68 69 #define FRAG6_CB(skb) ((struct ip6frag_skb_cb*)((skb)->cb)) 70 71 static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h) 72 { 73 return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK); 74 } 75 76 static struct inet_frags ip6_frags; 77 78 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 79 struct net_device *dev); 80 81 /* 82 * callers should be careful not to use the hash value outside the ipfrag_lock 83 * as doing so could race with ipfrag_hash_rnd being recalculated. 84 */ 85 static unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, 86 const struct in6_addr *daddr) 87 { 88 net_get_random_once(&ip6_frags.rnd, sizeof(ip6_frags.rnd)); 89 return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), 90 (__force u32)id, ip6_frags.rnd); 91 } 92 93 static unsigned int ip6_hashfn(const struct inet_frag_queue *q) 94 { 95 const struct frag_queue *fq; 96 97 fq = container_of(q, struct frag_queue, q); 98 return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr); 99 } 100 101 bool ip6_frag_match(const struct inet_frag_queue *q, const void *a) 102 { 103 const struct frag_queue *fq; 104 const struct ip6_create_arg *arg = a; 105 106 fq = container_of(q, struct frag_queue, q); 107 return fq->id == arg->id && 108 fq->user == arg->user && 109 ipv6_addr_equal(&fq->saddr, arg->src) && 110 ipv6_addr_equal(&fq->daddr, arg->dst); 111 } 112 EXPORT_SYMBOL(ip6_frag_match); 113 114 void ip6_frag_init(struct inet_frag_queue *q, const void *a) 115 { 116 struct frag_queue *fq = container_of(q, struct frag_queue, q); 117 const struct ip6_create_arg *arg = a; 118 119 fq->id = arg->id; 120 fq->user = arg->user; 121 fq->saddr = *arg->src; 122 fq->daddr = *arg->dst; 123 fq->ecn = arg->ecn; 124 } 125 EXPORT_SYMBOL(ip6_frag_init); 126 127 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq, 128 struct inet_frags *frags) 129 { 130 struct net_device *dev = NULL; 131 132 spin_lock(&fq->q.lock); 133 134 if (fq->q.last_in & INET_FRAG_COMPLETE) 135 goto out; 136 137 inet_frag_kill(&fq->q, frags); 138 139 rcu_read_lock(); 140 dev = dev_get_by_index_rcu(net, fq->iif); 141 if (!dev) 142 goto out_rcu_unlock; 143 144 if (!(fq->q.last_in & INET_FRAG_EVICTED)) 145 IP6_INC_STATS_BH(net, __in6_dev_get(dev), 146 IPSTATS_MIB_REASMTIMEOUT); 147 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 148 149 /* Don't send error if the first segment did not arrive. */ 150 if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments) 151 goto out_rcu_unlock; 152 153 /* 154 But use as source device on which LAST ARRIVED 155 segment was received. And do not use fq->dev 156 pointer directly, device might already disappeared. 157 */ 158 fq->q.fragments->dev = dev; 159 icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); 160 out_rcu_unlock: 161 rcu_read_unlock(); 162 out: 163 spin_unlock(&fq->q.lock); 164 inet_frag_put(&fq->q, frags); 165 } 166 EXPORT_SYMBOL(ip6_expire_frag_queue); 167 168 static void ip6_frag_expire(unsigned long data) 169 { 170 struct frag_queue *fq; 171 struct net *net; 172 173 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); 174 net = container_of(fq->q.net, struct net, ipv6.frags); 175 176 ip6_expire_frag_queue(net, fq, &ip6_frags); 177 } 178 179 static __inline__ struct frag_queue * 180 fq_find(struct net *net, __be32 id, const struct in6_addr *src, 181 const struct in6_addr *dst, u8 ecn) 182 { 183 struct inet_frag_queue *q; 184 struct ip6_create_arg arg; 185 unsigned int hash; 186 187 arg.id = id; 188 arg.user = IP6_DEFRAG_LOCAL_DELIVER; 189 arg.src = src; 190 arg.dst = dst; 191 arg.ecn = ecn; 192 193 read_lock(&ip6_frags.lock); 194 hash = inet6_hash_frag(id, src, dst); 195 196 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); 197 if (IS_ERR_OR_NULL(q)) { 198 inet_frag_maybe_warn_overflow(q, pr_fmt()); 199 return NULL; 200 } 201 return container_of(q, struct frag_queue, q); 202 } 203 204 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, 205 struct frag_hdr *fhdr, int nhoff) 206 { 207 struct sk_buff *prev, *next; 208 struct net_device *dev; 209 int offset, end; 210 struct net *net = dev_net(skb_dst(skb)->dev); 211 u8 ecn; 212 213 if (fq->q.last_in & INET_FRAG_COMPLETE) 214 goto err; 215 216 offset = ntohs(fhdr->frag_off) & ~0x7; 217 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - 218 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); 219 220 if ((unsigned int)end > IPV6_MAXPLEN) { 221 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 222 IPSTATS_MIB_INHDRERRORS); 223 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 224 ((u8 *)&fhdr->frag_off - 225 skb_network_header(skb))); 226 return -1; 227 } 228 229 ecn = ip6_frag_ecn(ipv6_hdr(skb)); 230 231 if (skb->ip_summed == CHECKSUM_COMPLETE) { 232 const unsigned char *nh = skb_network_header(skb); 233 skb->csum = csum_sub(skb->csum, 234 csum_partial(nh, (u8 *)(fhdr + 1) - nh, 235 0)); 236 } 237 238 /* Is this the final fragment? */ 239 if (!(fhdr->frag_off & htons(IP6_MF))) { 240 /* If we already have some bits beyond end 241 * or have different end, the segment is corrupted. 242 */ 243 if (end < fq->q.len || 244 ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) 245 goto err; 246 fq->q.last_in |= INET_FRAG_LAST_IN; 247 fq->q.len = end; 248 } else { 249 /* Check if the fragment is rounded to 8 bytes. 250 * Required by the RFC. 251 */ 252 if (end & 0x7) { 253 /* RFC2460 says always send parameter problem in 254 * this case. -DaveM 255 */ 256 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 257 IPSTATS_MIB_INHDRERRORS); 258 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 259 offsetof(struct ipv6hdr, payload_len)); 260 return -1; 261 } 262 if (end > fq->q.len) { 263 /* Some bits beyond end -> corruption. */ 264 if (fq->q.last_in & INET_FRAG_LAST_IN) 265 goto err; 266 fq->q.len = end; 267 } 268 } 269 270 if (end == offset) 271 goto err; 272 273 /* Point into the IP datagram 'data' part. */ 274 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) 275 goto err; 276 277 if (pskb_trim_rcsum(skb, end - offset)) 278 goto err; 279 280 /* Find out which fragments are in front and at the back of us 281 * in the chain of fragments so far. We must know where to put 282 * this fragment, right? 283 */ 284 prev = fq->q.fragments_tail; 285 if (!prev || FRAG6_CB(prev)->offset < offset) { 286 next = NULL; 287 goto found; 288 } 289 prev = NULL; 290 for(next = fq->q.fragments; next != NULL; next = next->next) { 291 if (FRAG6_CB(next)->offset >= offset) 292 break; /* bingo! */ 293 prev = next; 294 } 295 296 found: 297 /* RFC5722, Section 4, amended by Errata ID : 3089 298 * When reassembling an IPv6 datagram, if 299 * one or more its constituent fragments is determined to be an 300 * overlapping fragment, the entire datagram (and any constituent 301 * fragments) MUST be silently discarded. 302 */ 303 304 /* Check for overlap with preceding fragment. */ 305 if (prev && 306 (FRAG6_CB(prev)->offset + prev->len) > offset) 307 goto discard_fq; 308 309 /* Look for overlap with succeeding segment. */ 310 if (next && FRAG6_CB(next)->offset < end) 311 goto discard_fq; 312 313 FRAG6_CB(skb)->offset = offset; 314 315 /* Insert this fragment in the chain of fragments. */ 316 skb->next = next; 317 if (!next) 318 fq->q.fragments_tail = skb; 319 if (prev) 320 prev->next = skb; 321 else 322 fq->q.fragments = skb; 323 324 dev = skb->dev; 325 if (dev) { 326 fq->iif = dev->ifindex; 327 skb->dev = NULL; 328 } 329 fq->q.stamp = skb->tstamp; 330 fq->q.meat += skb->len; 331 fq->ecn |= ecn; 332 add_frag_mem_limit(&fq->q, skb->truesize); 333 334 /* The first fragment. 335 * nhoffset is obtained from the first fragment, of course. 336 */ 337 if (offset == 0) { 338 fq->nhoffset = nhoff; 339 fq->q.last_in |= INET_FRAG_FIRST_IN; 340 } 341 342 if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 343 fq->q.meat == fq->q.len) { 344 int res; 345 unsigned long orefdst = skb->_skb_refdst; 346 347 skb->_skb_refdst = 0UL; 348 res = ip6_frag_reasm(fq, prev, dev); 349 skb->_skb_refdst = orefdst; 350 return res; 351 } 352 353 skb_dst_drop(skb); 354 return -1; 355 356 discard_fq: 357 inet_frag_kill(&fq->q, &ip6_frags); 358 err: 359 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 360 IPSTATS_MIB_REASMFAILS); 361 kfree_skb(skb); 362 return -1; 363 } 364 365 /* 366 * Check if this packet is complete. 367 * Returns NULL on failure by any reason, and pointer 368 * to current nexthdr field in reassembled frame. 369 * 370 * It is called with locked fq, and caller must check that 371 * queue is eligible for reassembly i.e. it is not COMPLETE, 372 * the last and the first frames arrived and all the bits are here. 373 */ 374 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 375 struct net_device *dev) 376 { 377 struct net *net = container_of(fq->q.net, struct net, ipv6.frags); 378 struct sk_buff *fp, *head = fq->q.fragments; 379 int payload_len; 380 unsigned int nhoff; 381 int sum_truesize; 382 u8 ecn; 383 384 inet_frag_kill(&fq->q, &ip6_frags); 385 386 ecn = ip_frag_ecn_table[fq->ecn]; 387 if (unlikely(ecn == 0xff)) 388 goto out_fail; 389 390 /* Make the one we just received the head. */ 391 if (prev) { 392 head = prev->next; 393 fp = skb_clone(head, GFP_ATOMIC); 394 395 if (!fp) 396 goto out_oom; 397 398 fp->next = head->next; 399 if (!fp->next) 400 fq->q.fragments_tail = fp; 401 prev->next = fp; 402 403 skb_morph(head, fq->q.fragments); 404 head->next = fq->q.fragments->next; 405 406 consume_skb(fq->q.fragments); 407 fq->q.fragments = head; 408 } 409 410 WARN_ON(head == NULL); 411 WARN_ON(FRAG6_CB(head)->offset != 0); 412 413 /* Unfragmented part is taken from the first segment. */ 414 payload_len = ((head->data - skb_network_header(head)) - 415 sizeof(struct ipv6hdr) + fq->q.len - 416 sizeof(struct frag_hdr)); 417 if (payload_len > IPV6_MAXPLEN) 418 goto out_oversize; 419 420 /* Head of list must not be cloned. */ 421 if (skb_unclone(head, GFP_ATOMIC)) 422 goto out_oom; 423 424 /* If the first fragment is fragmented itself, we split 425 * it to two chunks: the first with data and paged part 426 * and the second, holding only fragments. */ 427 if (skb_has_frag_list(head)) { 428 struct sk_buff *clone; 429 int i, plen = 0; 430 431 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) 432 goto out_oom; 433 clone->next = head->next; 434 head->next = clone; 435 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 436 skb_frag_list_init(head); 437 for (i = 0; i < skb_shinfo(head)->nr_frags; i++) 438 plen += skb_frag_size(&skb_shinfo(head)->frags[i]); 439 clone->len = clone->data_len = head->data_len - plen; 440 head->data_len -= clone->len; 441 head->len -= clone->len; 442 clone->csum = 0; 443 clone->ip_summed = head->ip_summed; 444 add_frag_mem_limit(&fq->q, clone->truesize); 445 } 446 447 /* We have to remove fragment header from datagram and to relocate 448 * header in order to calculate ICV correctly. */ 449 nhoff = fq->nhoffset; 450 skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; 451 memmove(head->head + sizeof(struct frag_hdr), head->head, 452 (head->data - head->head) - sizeof(struct frag_hdr)); 453 head->mac_header += sizeof(struct frag_hdr); 454 head->network_header += sizeof(struct frag_hdr); 455 456 skb_reset_transport_header(head); 457 skb_push(head, head->data - skb_network_header(head)); 458 459 sum_truesize = head->truesize; 460 for (fp = head->next; fp;) { 461 bool headstolen; 462 int delta; 463 struct sk_buff *next = fp->next; 464 465 sum_truesize += fp->truesize; 466 if (head->ip_summed != fp->ip_summed) 467 head->ip_summed = CHECKSUM_NONE; 468 else if (head->ip_summed == CHECKSUM_COMPLETE) 469 head->csum = csum_add(head->csum, fp->csum); 470 471 if (skb_try_coalesce(head, fp, &headstolen, &delta)) { 472 kfree_skb_partial(fp, headstolen); 473 } else { 474 if (!skb_shinfo(head)->frag_list) 475 skb_shinfo(head)->frag_list = fp; 476 head->data_len += fp->len; 477 head->len += fp->len; 478 head->truesize += fp->truesize; 479 } 480 fp = next; 481 } 482 sub_frag_mem_limit(&fq->q, sum_truesize); 483 484 head->next = NULL; 485 head->dev = dev; 486 head->tstamp = fq->q.stamp; 487 ipv6_hdr(head)->payload_len = htons(payload_len); 488 ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); 489 IP6CB(head)->nhoff = nhoff; 490 IP6CB(head)->flags |= IP6SKB_FRAGMENTED; 491 492 /* Yes, and fold redundant checksum back. 8) */ 493 if (head->ip_summed == CHECKSUM_COMPLETE) 494 head->csum = csum_partial(skb_network_header(head), 495 skb_network_header_len(head), 496 head->csum); 497 498 rcu_read_lock(); 499 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); 500 rcu_read_unlock(); 501 fq->q.fragments = NULL; 502 fq->q.fragments_tail = NULL; 503 return 1; 504 505 out_oversize: 506 net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); 507 goto out_fail; 508 out_oom: 509 net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); 510 out_fail: 511 rcu_read_lock(); 512 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 513 rcu_read_unlock(); 514 return -1; 515 } 516 517 static int ipv6_frag_rcv(struct sk_buff *skb) 518 { 519 struct frag_hdr *fhdr; 520 struct frag_queue *fq; 521 const struct ipv6hdr *hdr = ipv6_hdr(skb); 522 struct net *net = dev_net(skb_dst(skb)->dev); 523 524 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED) 525 goto fail_hdr; 526 527 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); 528 529 /* Jumbo payload inhibits frag. header */ 530 if (hdr->payload_len==0) 531 goto fail_hdr; 532 533 if (!pskb_may_pull(skb, (skb_transport_offset(skb) + 534 sizeof(struct frag_hdr)))) 535 goto fail_hdr; 536 537 hdr = ipv6_hdr(skb); 538 fhdr = (struct frag_hdr *)skb_transport_header(skb); 539 540 if (!(fhdr->frag_off & htons(0xFFF9))) { 541 /* It is not a fragmented frame */ 542 skb->transport_header += sizeof(struct frag_hdr); 543 IP6_INC_STATS_BH(net, 544 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); 545 546 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); 547 IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; 548 return 1; 549 } 550 551 fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, 552 ip6_frag_ecn(hdr)); 553 if (fq != NULL) { 554 int ret; 555 556 spin_lock(&fq->q.lock); 557 558 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); 559 560 spin_unlock(&fq->q.lock); 561 inet_frag_put(&fq->q, &ip6_frags); 562 return ret; 563 } 564 565 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); 566 kfree_skb(skb); 567 return -1; 568 569 fail_hdr: 570 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); 571 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); 572 return -1; 573 } 574 575 static const struct inet6_protocol frag_protocol = 576 { 577 .handler = ipv6_frag_rcv, 578 .flags = INET6_PROTO_NOPOLICY, 579 }; 580 581 #ifdef CONFIG_SYSCTL 582 static struct ctl_table ip6_frags_ns_ctl_table[] = { 583 { 584 .procname = "ip6frag_high_thresh", 585 .data = &init_net.ipv6.frags.high_thresh, 586 .maxlen = sizeof(int), 587 .mode = 0644, 588 .proc_handler = proc_dointvec 589 }, 590 { 591 .procname = "ip6frag_low_thresh", 592 .data = &init_net.ipv6.frags.low_thresh, 593 .maxlen = sizeof(int), 594 .mode = 0644, 595 .proc_handler = proc_dointvec 596 }, 597 { 598 .procname = "ip6frag_time", 599 .data = &init_net.ipv6.frags.timeout, 600 .maxlen = sizeof(int), 601 .mode = 0644, 602 .proc_handler = proc_dointvec_jiffies, 603 }, 604 { } 605 }; 606 607 static struct ctl_table ip6_frags_ctl_table[] = { 608 { 609 .procname = "ip6frag_secret_interval", 610 .data = &ip6_frags.secret_interval, 611 .maxlen = sizeof(int), 612 .mode = 0644, 613 .proc_handler = proc_dointvec_jiffies, 614 }, 615 { } 616 }; 617 618 static int __net_init ip6_frags_ns_sysctl_register(struct net *net) 619 { 620 struct ctl_table *table; 621 struct ctl_table_header *hdr; 622 623 table = ip6_frags_ns_ctl_table; 624 if (!net_eq(net, &init_net)) { 625 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); 626 if (table == NULL) 627 goto err_alloc; 628 629 table[0].data = &net->ipv6.frags.high_thresh; 630 table[1].data = &net->ipv6.frags.low_thresh; 631 table[2].data = &net->ipv6.frags.timeout; 632 633 /* Don't export sysctls to unprivileged users */ 634 if (net->user_ns != &init_user_ns) 635 table[0].procname = NULL; 636 } 637 638 hdr = register_net_sysctl(net, "net/ipv6", table); 639 if (hdr == NULL) 640 goto err_reg; 641 642 net->ipv6.sysctl.frags_hdr = hdr; 643 return 0; 644 645 err_reg: 646 if (!net_eq(net, &init_net)) 647 kfree(table); 648 err_alloc: 649 return -ENOMEM; 650 } 651 652 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) 653 { 654 struct ctl_table *table; 655 656 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; 657 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); 658 if (!net_eq(net, &init_net)) 659 kfree(table); 660 } 661 662 static struct ctl_table_header *ip6_ctl_header; 663 664 static int ip6_frags_sysctl_register(void) 665 { 666 ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", 667 ip6_frags_ctl_table); 668 return ip6_ctl_header == NULL ? -ENOMEM : 0; 669 } 670 671 static void ip6_frags_sysctl_unregister(void) 672 { 673 unregister_net_sysctl_table(ip6_ctl_header); 674 } 675 #else 676 static inline int ip6_frags_ns_sysctl_register(struct net *net) 677 { 678 return 0; 679 } 680 681 static inline void ip6_frags_ns_sysctl_unregister(struct net *net) 682 { 683 } 684 685 static inline int ip6_frags_sysctl_register(void) 686 { 687 return 0; 688 } 689 690 static inline void ip6_frags_sysctl_unregister(void) 691 { 692 } 693 #endif 694 695 static int __net_init ipv6_frags_init_net(struct net *net) 696 { 697 net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; 698 net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; 699 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; 700 701 inet_frags_init_net(&net->ipv6.frags); 702 703 return ip6_frags_ns_sysctl_register(net); 704 } 705 706 static void __net_exit ipv6_frags_exit_net(struct net *net) 707 { 708 ip6_frags_ns_sysctl_unregister(net); 709 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); 710 } 711 712 static struct pernet_operations ip6_frags_ops = { 713 .init = ipv6_frags_init_net, 714 .exit = ipv6_frags_exit_net, 715 }; 716 717 int __init ipv6_frag_init(void) 718 { 719 int ret; 720 721 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); 722 if (ret) 723 goto out; 724 725 ret = ip6_frags_sysctl_register(); 726 if (ret) 727 goto err_sysctl; 728 729 ret = register_pernet_subsys(&ip6_frags_ops); 730 if (ret) 731 goto err_pernet; 732 733 ip6_frags.hashfn = ip6_hashfn; 734 ip6_frags.constructor = ip6_frag_init; 735 ip6_frags.destructor = NULL; 736 ip6_frags.skb_free = NULL; 737 ip6_frags.qsize = sizeof(struct frag_queue); 738 ip6_frags.match = ip6_frag_match; 739 ip6_frags.frag_expire = ip6_frag_expire; 740 ip6_frags.secret_interval = 10 * 60 * HZ; 741 inet_frags_init(&ip6_frags); 742 out: 743 return ret; 744 745 err_pernet: 746 ip6_frags_sysctl_unregister(); 747 err_sysctl: 748 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 749 goto out; 750 } 751 752 void ipv6_frag_exit(void) 753 { 754 inet_frags_fini(&ip6_frags); 755 ip6_frags_sysctl_unregister(); 756 unregister_pernet_subsys(&ip6_frags_ops); 757 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 758 } 759