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 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, 86 const struct in6_addr *daddr, u32 rnd) 87 { 88 u32 c; 89 90 c = jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), 91 (__force u32)id, rnd); 92 93 return c & (INETFRAGS_HASHSZ - 1); 94 } 95 EXPORT_SYMBOL_GPL(inet6_hash_frag); 96 97 static unsigned int ip6_hashfn(struct inet_frag_queue *q) 98 { 99 struct frag_queue *fq; 100 101 fq = container_of(q, struct frag_queue, q); 102 return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd); 103 } 104 105 bool ip6_frag_match(struct inet_frag_queue *q, void *a) 106 { 107 struct frag_queue *fq; 108 struct ip6_create_arg *arg = a; 109 110 fq = container_of(q, struct frag_queue, q); 111 return fq->id == arg->id && 112 fq->user == arg->user && 113 ipv6_addr_equal(&fq->saddr, arg->src) && 114 ipv6_addr_equal(&fq->daddr, arg->dst); 115 } 116 EXPORT_SYMBOL(ip6_frag_match); 117 118 void ip6_frag_init(struct inet_frag_queue *q, void *a) 119 { 120 struct frag_queue *fq = container_of(q, struct frag_queue, q); 121 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.last_in & 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_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); 149 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 150 151 /* Don't send error if the first segment did not arrive. */ 152 if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments) 153 goto out_rcu_unlock; 154 155 /* 156 But use as source device on which LAST ARRIVED 157 segment was received. And do not use fq->dev 158 pointer directly, device might already disappeared. 159 */ 160 fq->q.fragments->dev = dev; 161 icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); 162 out_rcu_unlock: 163 rcu_read_unlock(); 164 out: 165 spin_unlock(&fq->q.lock); 166 inet_frag_put(&fq->q, frags); 167 } 168 EXPORT_SYMBOL(ip6_expire_frag_queue); 169 170 static void ip6_frag_expire(unsigned long data) 171 { 172 struct frag_queue *fq; 173 struct net *net; 174 175 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); 176 net = container_of(fq->q.net, struct net, ipv6.frags); 177 178 ip6_expire_frag_queue(net, fq, &ip6_frags); 179 } 180 181 static __inline__ struct frag_queue * 182 fq_find(struct net *net, __be32 id, const struct in6_addr *src, 183 const struct in6_addr *dst, u8 ecn) 184 { 185 struct inet_frag_queue *q; 186 struct ip6_create_arg arg; 187 unsigned int hash; 188 189 arg.id = id; 190 arg.user = IP6_DEFRAG_LOCAL_DELIVER; 191 arg.src = src; 192 arg.dst = dst; 193 arg.ecn = ecn; 194 195 read_lock(&ip6_frags.lock); 196 hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd); 197 198 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); 199 if (IS_ERR_OR_NULL(q)) { 200 inet_frag_maybe_warn_overflow(q, pr_fmt()); 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 u8 ecn; 214 215 if (fq->q.last_in & INET_FRAG_COMPLETE) 216 goto err; 217 218 offset = ntohs(fhdr->frag_off) & ~0x7; 219 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - 220 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); 221 222 if ((unsigned int)end > IPV6_MAXPLEN) { 223 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 224 IPSTATS_MIB_INHDRERRORS); 225 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 226 ((u8 *)&fhdr->frag_off - 227 skb_network_header(skb))); 228 return -1; 229 } 230 231 ecn = ip6_frag_ecn(ipv6_hdr(skb)); 232 233 if (skb->ip_summed == CHECKSUM_COMPLETE) { 234 const unsigned char *nh = skb_network_header(skb); 235 skb->csum = csum_sub(skb->csum, 236 csum_partial(nh, (u8 *)(fhdr + 1) - nh, 237 0)); 238 } 239 240 /* Is this the final fragment? */ 241 if (!(fhdr->frag_off & htons(IP6_MF))) { 242 /* If we already have some bits beyond end 243 * or have different end, the segment is corrupted. 244 */ 245 if (end < fq->q.len || 246 ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) 247 goto err; 248 fq->q.last_in |= INET_FRAG_LAST_IN; 249 fq->q.len = end; 250 } else { 251 /* Check if the fragment is rounded to 8 bytes. 252 * Required by the RFC. 253 */ 254 if (end & 0x7) { 255 /* RFC2460 says always send parameter problem in 256 * this case. -DaveM 257 */ 258 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 259 IPSTATS_MIB_INHDRERRORS); 260 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 261 offsetof(struct ipv6hdr, payload_len)); 262 return -1; 263 } 264 if (end > fq->q.len) { 265 /* Some bits beyond end -> corruption. */ 266 if (fq->q.last_in & INET_FRAG_LAST_IN) 267 goto err; 268 fq->q.len = end; 269 } 270 } 271 272 if (end == offset) 273 goto err; 274 275 /* Point into the IP datagram 'data' part. */ 276 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) 277 goto err; 278 279 if (pskb_trim_rcsum(skb, end - offset)) 280 goto err; 281 282 /* Find out which fragments are in front and at the back of us 283 * in the chain of fragments so far. We must know where to put 284 * this fragment, right? 285 */ 286 prev = fq->q.fragments_tail; 287 if (!prev || FRAG6_CB(prev)->offset < offset) { 288 next = NULL; 289 goto found; 290 } 291 prev = NULL; 292 for(next = fq->q.fragments; next != NULL; next = next->next) { 293 if (FRAG6_CB(next)->offset >= offset) 294 break; /* bingo! */ 295 prev = next; 296 } 297 298 found: 299 /* RFC5722, Section 4, amended by Errata ID : 3089 300 * When reassembling an IPv6 datagram, if 301 * one or more its constituent fragments is determined to be an 302 * overlapping fragment, the entire datagram (and any constituent 303 * fragments) MUST be silently discarded. 304 */ 305 306 /* Check for overlap with preceding fragment. */ 307 if (prev && 308 (FRAG6_CB(prev)->offset + prev->len) > offset) 309 goto discard_fq; 310 311 /* Look for overlap with succeeding segment. */ 312 if (next && FRAG6_CB(next)->offset < end) 313 goto discard_fq; 314 315 FRAG6_CB(skb)->offset = offset; 316 317 /* Insert this fragment in the chain of fragments. */ 318 skb->next = next; 319 if (!next) 320 fq->q.fragments_tail = skb; 321 if (prev) 322 prev->next = skb; 323 else 324 fq->q.fragments = skb; 325 326 dev = skb->dev; 327 if (dev) { 328 fq->iif = dev->ifindex; 329 skb->dev = NULL; 330 } 331 fq->q.stamp = skb->tstamp; 332 fq->q.meat += skb->len; 333 fq->ecn |= ecn; 334 add_frag_mem_limit(&fq->q, skb->truesize); 335 336 /* The first fragment. 337 * nhoffset is obtained from the first fragment, of course. 338 */ 339 if (offset == 0) { 340 fq->nhoffset = nhoff; 341 fq->q.last_in |= INET_FRAG_FIRST_IN; 342 } 343 344 if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 345 fq->q.meat == fq->q.len) 346 return ip6_frag_reasm(fq, prev, dev); 347 348 inet_frag_lru_move(&fq->q); 349 return -1; 350 351 discard_fq: 352 inet_frag_kill(&fq->q, &ip6_frags); 353 err: 354 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 355 IPSTATS_MIB_REASMFAILS); 356 kfree_skb(skb); 357 return -1; 358 } 359 360 /* 361 * Check if this packet is complete. 362 * Returns NULL on failure by any reason, and pointer 363 * to current nexthdr field in reassembled frame. 364 * 365 * It is called with locked fq, and caller must check that 366 * queue is eligible for reassembly i.e. it is not COMPLETE, 367 * the last and the first frames arrived and all the bits are here. 368 */ 369 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 370 struct net_device *dev) 371 { 372 struct net *net = container_of(fq->q.net, struct net, ipv6.frags); 373 struct sk_buff *fp, *head = fq->q.fragments; 374 int payload_len; 375 unsigned int nhoff; 376 int sum_truesize; 377 u8 ecn; 378 379 inet_frag_kill(&fq->q, &ip6_frags); 380 381 ecn = ip_frag_ecn_table[fq->ecn]; 382 if (unlikely(ecn == 0xff)) 383 goto out_fail; 384 385 /* Make the one we just received the head. */ 386 if (prev) { 387 head = prev->next; 388 fp = skb_clone(head, GFP_ATOMIC); 389 390 if (!fp) 391 goto out_oom; 392 393 fp->next = head->next; 394 if (!fp->next) 395 fq->q.fragments_tail = fp; 396 prev->next = fp; 397 398 skb_morph(head, fq->q.fragments); 399 head->next = fq->q.fragments->next; 400 401 consume_skb(fq->q.fragments); 402 fq->q.fragments = head; 403 } 404 405 WARN_ON(head == NULL); 406 WARN_ON(FRAG6_CB(head)->offset != 0); 407 408 /* Unfragmented part is taken from the first segment. */ 409 payload_len = ((head->data - skb_network_header(head)) - 410 sizeof(struct ipv6hdr) + fq->q.len - 411 sizeof(struct frag_hdr)); 412 if (payload_len > IPV6_MAXPLEN) 413 goto out_oversize; 414 415 /* Head of list must not be cloned. */ 416 if (skb_unclone(head, GFP_ATOMIC)) 417 goto out_oom; 418 419 /* If the first fragment is fragmented itself, we split 420 * it to two chunks: the first with data and paged part 421 * and the second, holding only fragments. */ 422 if (skb_has_frag_list(head)) { 423 struct sk_buff *clone; 424 int i, plen = 0; 425 426 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) 427 goto out_oom; 428 clone->next = head->next; 429 head->next = clone; 430 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 431 skb_frag_list_init(head); 432 for (i = 0; i < skb_shinfo(head)->nr_frags; i++) 433 plen += skb_frag_size(&skb_shinfo(head)->frags[i]); 434 clone->len = clone->data_len = head->data_len - plen; 435 head->data_len -= clone->len; 436 head->len -= clone->len; 437 clone->csum = 0; 438 clone->ip_summed = head->ip_summed; 439 add_frag_mem_limit(&fq->q, clone->truesize); 440 } 441 442 /* We have to remove fragment header from datagram and to relocate 443 * header in order to calculate ICV correctly. */ 444 nhoff = fq->nhoffset; 445 skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; 446 memmove(head->head + sizeof(struct frag_hdr), head->head, 447 (head->data - head->head) - sizeof(struct frag_hdr)); 448 head->mac_header += sizeof(struct frag_hdr); 449 head->network_header += sizeof(struct frag_hdr); 450 451 skb_reset_transport_header(head); 452 skb_push(head, head->data - skb_network_header(head)); 453 454 sum_truesize = head->truesize; 455 for (fp = head->next; fp;) { 456 bool headstolen; 457 int delta; 458 struct sk_buff *next = fp->next; 459 460 sum_truesize += fp->truesize; 461 if (head->ip_summed != fp->ip_summed) 462 head->ip_summed = CHECKSUM_NONE; 463 else if (head->ip_summed == CHECKSUM_COMPLETE) 464 head->csum = csum_add(head->csum, fp->csum); 465 466 if (skb_try_coalesce(head, fp, &headstolen, &delta)) { 467 kfree_skb_partial(fp, headstolen); 468 } else { 469 if (!skb_shinfo(head)->frag_list) 470 skb_shinfo(head)->frag_list = fp; 471 head->data_len += fp->len; 472 head->len += fp->len; 473 head->truesize += fp->truesize; 474 } 475 fp = next; 476 } 477 sub_frag_mem_limit(&fq->q, sum_truesize); 478 479 head->next = NULL; 480 head->dev = dev; 481 head->tstamp = fq->q.stamp; 482 ipv6_hdr(head)->payload_len = htons(payload_len); 483 ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); 484 IP6CB(head)->nhoff = nhoff; 485 486 /* Yes, and fold redundant checksum back. 8) */ 487 if (head->ip_summed == CHECKSUM_COMPLETE) 488 head->csum = csum_partial(skb_network_header(head), 489 skb_network_header_len(head), 490 head->csum); 491 492 rcu_read_lock(); 493 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); 494 rcu_read_unlock(); 495 fq->q.fragments = NULL; 496 fq->q.fragments_tail = NULL; 497 return 1; 498 499 out_oversize: 500 net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); 501 goto out_fail; 502 out_oom: 503 net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); 504 out_fail: 505 rcu_read_lock(); 506 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 507 rcu_read_unlock(); 508 return -1; 509 } 510 511 static int ipv6_frag_rcv(struct sk_buff *skb) 512 { 513 struct frag_hdr *fhdr; 514 struct frag_queue *fq; 515 const struct ipv6hdr *hdr = ipv6_hdr(skb); 516 struct net *net = dev_net(skb_dst(skb)->dev); 517 int evicted; 518 519 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); 520 521 /* Jumbo payload inhibits frag. header */ 522 if (hdr->payload_len==0) 523 goto fail_hdr; 524 525 if (!pskb_may_pull(skb, (skb_transport_offset(skb) + 526 sizeof(struct frag_hdr)))) 527 goto fail_hdr; 528 529 hdr = ipv6_hdr(skb); 530 fhdr = (struct frag_hdr *)skb_transport_header(skb); 531 532 if (!(fhdr->frag_off & htons(0xFFF9))) { 533 /* It is not a fragmented frame */ 534 skb->transport_header += sizeof(struct frag_hdr); 535 IP6_INC_STATS_BH(net, 536 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); 537 538 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); 539 return 1; 540 } 541 542 evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags, false); 543 if (evicted) 544 IP6_ADD_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 545 IPSTATS_MIB_REASMFAILS, evicted); 546 547 fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, 548 ip6_frag_ecn(hdr)); 549 if (fq != NULL) { 550 int ret; 551 552 spin_lock(&fq->q.lock); 553 554 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); 555 556 spin_unlock(&fq->q.lock); 557 inet_frag_put(&fq->q, &ip6_frags); 558 return ret; 559 } 560 561 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); 562 kfree_skb(skb); 563 return -1; 564 565 fail_hdr: 566 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); 567 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); 568 return -1; 569 } 570 571 static const struct inet6_protocol frag_protocol = 572 { 573 .handler = ipv6_frag_rcv, 574 .flags = INET6_PROTO_NOPOLICY, 575 }; 576 577 #ifdef CONFIG_SYSCTL 578 static struct ctl_table ip6_frags_ns_ctl_table[] = { 579 { 580 .procname = "ip6frag_high_thresh", 581 .data = &init_net.ipv6.frags.high_thresh, 582 .maxlen = sizeof(int), 583 .mode = 0644, 584 .proc_handler = proc_dointvec 585 }, 586 { 587 .procname = "ip6frag_low_thresh", 588 .data = &init_net.ipv6.frags.low_thresh, 589 .maxlen = sizeof(int), 590 .mode = 0644, 591 .proc_handler = proc_dointvec 592 }, 593 { 594 .procname = "ip6frag_time", 595 .data = &init_net.ipv6.frags.timeout, 596 .maxlen = sizeof(int), 597 .mode = 0644, 598 .proc_handler = proc_dointvec_jiffies, 599 }, 600 { } 601 }; 602 603 static struct ctl_table ip6_frags_ctl_table[] = { 604 { 605 .procname = "ip6frag_secret_interval", 606 .data = &ip6_frags.secret_interval, 607 .maxlen = sizeof(int), 608 .mode = 0644, 609 .proc_handler = proc_dointvec_jiffies, 610 }, 611 { } 612 }; 613 614 static int __net_init ip6_frags_ns_sysctl_register(struct net *net) 615 { 616 struct ctl_table *table; 617 struct ctl_table_header *hdr; 618 619 table = ip6_frags_ns_ctl_table; 620 if (!net_eq(net, &init_net)) { 621 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); 622 if (table == NULL) 623 goto err_alloc; 624 625 table[0].data = &net->ipv6.frags.high_thresh; 626 table[1].data = &net->ipv6.frags.low_thresh; 627 table[2].data = &net->ipv6.frags.timeout; 628 629 /* Don't export sysctls to unprivileged users */ 630 if (net->user_ns != &init_user_ns) 631 table[0].procname = NULL; 632 } 633 634 hdr = register_net_sysctl(net, "net/ipv6", table); 635 if (hdr == NULL) 636 goto err_reg; 637 638 net->ipv6.sysctl.frags_hdr = hdr; 639 return 0; 640 641 err_reg: 642 if (!net_eq(net, &init_net)) 643 kfree(table); 644 err_alloc: 645 return -ENOMEM; 646 } 647 648 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) 649 { 650 struct ctl_table *table; 651 652 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; 653 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); 654 if (!net_eq(net, &init_net)) 655 kfree(table); 656 } 657 658 static struct ctl_table_header *ip6_ctl_header; 659 660 static int ip6_frags_sysctl_register(void) 661 { 662 ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", 663 ip6_frags_ctl_table); 664 return ip6_ctl_header == NULL ? -ENOMEM : 0; 665 } 666 667 static void ip6_frags_sysctl_unregister(void) 668 { 669 unregister_net_sysctl_table(ip6_ctl_header); 670 } 671 #else 672 static inline int ip6_frags_ns_sysctl_register(struct net *net) 673 { 674 return 0; 675 } 676 677 static inline void ip6_frags_ns_sysctl_unregister(struct net *net) 678 { 679 } 680 681 static inline int ip6_frags_sysctl_register(void) 682 { 683 return 0; 684 } 685 686 static inline void ip6_frags_sysctl_unregister(void) 687 { 688 } 689 #endif 690 691 static int __net_init ipv6_frags_init_net(struct net *net) 692 { 693 net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; 694 net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; 695 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; 696 697 inet_frags_init_net(&net->ipv6.frags); 698 699 return ip6_frags_ns_sysctl_register(net); 700 } 701 702 static void __net_exit ipv6_frags_exit_net(struct net *net) 703 { 704 ip6_frags_ns_sysctl_unregister(net); 705 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); 706 } 707 708 static struct pernet_operations ip6_frags_ops = { 709 .init = ipv6_frags_init_net, 710 .exit = ipv6_frags_exit_net, 711 }; 712 713 int __init ipv6_frag_init(void) 714 { 715 int ret; 716 717 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); 718 if (ret) 719 goto out; 720 721 ret = ip6_frags_sysctl_register(); 722 if (ret) 723 goto err_sysctl; 724 725 ret = register_pernet_subsys(&ip6_frags_ops); 726 if (ret) 727 goto err_pernet; 728 729 ip6_frags.hashfn = ip6_hashfn; 730 ip6_frags.constructor = ip6_frag_init; 731 ip6_frags.destructor = NULL; 732 ip6_frags.skb_free = NULL; 733 ip6_frags.qsize = sizeof(struct frag_queue); 734 ip6_frags.match = ip6_frag_match; 735 ip6_frags.frag_expire = ip6_frag_expire; 736 ip6_frags.secret_interval = 10 * 60 * HZ; 737 inet_frags_init(&ip6_frags); 738 out: 739 return ret; 740 741 err_pernet: 742 ip6_frags_sysctl_unregister(); 743 err_sysctl: 744 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 745 goto out; 746 } 747 748 void ipv6_frag_exit(void) 749 { 750 inet_frags_fini(&ip6_frags); 751 ip6_frags_sysctl_unregister(); 752 unregister_pernet_subsys(&ip6_frags_ops); 753 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 754 } 755