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_BH(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_BH(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(unsigned long data) 174 { 175 struct frag_queue *fq; 176 struct net *net; 177 178 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); 179 net = container_of(fq->q.net, struct net, ipv6.frags); 180 181 ip6_expire_frag_queue(net, fq, &ip6_frags); 182 } 183 184 static struct frag_queue * 185 fq_find(struct net *net, __be32 id, const struct in6_addr *src, 186 const struct in6_addr *dst, int iif, u8 ecn) 187 { 188 struct inet_frag_queue *q; 189 struct ip6_create_arg arg; 190 unsigned int hash; 191 192 arg.id = id; 193 arg.user = IP6_DEFRAG_LOCAL_DELIVER; 194 arg.src = src; 195 arg.dst = dst; 196 arg.iif = iif; 197 arg.ecn = ecn; 198 199 hash = inet6_hash_frag(id, src, dst); 200 201 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); 202 if (IS_ERR_OR_NULL(q)) { 203 inet_frag_maybe_warn_overflow(q, pr_fmt()); 204 return NULL; 205 } 206 return container_of(q, struct frag_queue, q); 207 } 208 209 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, 210 struct frag_hdr *fhdr, int nhoff) 211 { 212 struct sk_buff *prev, *next; 213 struct net_device *dev; 214 int offset, end; 215 struct net *net = dev_net(skb_dst(skb)->dev); 216 u8 ecn; 217 218 if (fq->q.flags & INET_FRAG_COMPLETE) 219 goto err; 220 221 offset = ntohs(fhdr->frag_off) & ~0x7; 222 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - 223 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); 224 225 if ((unsigned int)end > IPV6_MAXPLEN) { 226 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 227 IPSTATS_MIB_INHDRERRORS); 228 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 229 ((u8 *)&fhdr->frag_off - 230 skb_network_header(skb))); 231 return -1; 232 } 233 234 ecn = ip6_frag_ecn(ipv6_hdr(skb)); 235 236 if (skb->ip_summed == CHECKSUM_COMPLETE) { 237 const unsigned char *nh = skb_network_header(skb); 238 skb->csum = csum_sub(skb->csum, 239 csum_partial(nh, (u8 *)(fhdr + 1) - nh, 240 0)); 241 } 242 243 /* Is this the final fragment? */ 244 if (!(fhdr->frag_off & htons(IP6_MF))) { 245 /* If we already have some bits beyond end 246 * or have different end, the segment is corrupted. 247 */ 248 if (end < fq->q.len || 249 ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len)) 250 goto err; 251 fq->q.flags |= INET_FRAG_LAST_IN; 252 fq->q.len = end; 253 } else { 254 /* Check if the fragment is rounded to 8 bytes. 255 * Required by the RFC. 256 */ 257 if (end & 0x7) { 258 /* RFC2460 says always send parameter problem in 259 * this case. -DaveM 260 */ 261 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 262 IPSTATS_MIB_INHDRERRORS); 263 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 264 offsetof(struct ipv6hdr, payload_len)); 265 return -1; 266 } 267 if (end > fq->q.len) { 268 /* Some bits beyond end -> corruption. */ 269 if (fq->q.flags & INET_FRAG_LAST_IN) 270 goto err; 271 fq->q.len = end; 272 } 273 } 274 275 if (end == offset) 276 goto err; 277 278 /* Point into the IP datagram 'data' part. */ 279 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) 280 goto err; 281 282 if (pskb_trim_rcsum(skb, end - offset)) 283 goto err; 284 285 /* Find out which fragments are in front and at the back of us 286 * in the chain of fragments so far. We must know where to put 287 * this fragment, right? 288 */ 289 prev = fq->q.fragments_tail; 290 if (!prev || FRAG6_CB(prev)->offset < offset) { 291 next = NULL; 292 goto found; 293 } 294 prev = NULL; 295 for (next = fq->q.fragments; next != NULL; next = next->next) { 296 if (FRAG6_CB(next)->offset >= offset) 297 break; /* bingo! */ 298 prev = next; 299 } 300 301 found: 302 /* RFC5722, Section 4, amended by Errata ID : 3089 303 * When reassembling an IPv6 datagram, if 304 * one or more its constituent fragments is determined to be an 305 * overlapping fragment, the entire datagram (and any constituent 306 * fragments) MUST be silently discarded. 307 */ 308 309 /* Check for overlap with preceding fragment. */ 310 if (prev && 311 (FRAG6_CB(prev)->offset + prev->len) > offset) 312 goto discard_fq; 313 314 /* Look for overlap with succeeding segment. */ 315 if (next && FRAG6_CB(next)->offset < end) 316 goto discard_fq; 317 318 FRAG6_CB(skb)->offset = offset; 319 320 /* Insert this fragment in the chain of fragments. */ 321 skb->next = next; 322 if (!next) 323 fq->q.fragments_tail = skb; 324 if (prev) 325 prev->next = skb; 326 else 327 fq->q.fragments = skb; 328 329 dev = skb->dev; 330 if (dev) { 331 fq->iif = dev->ifindex; 332 skb->dev = NULL; 333 } 334 fq->q.stamp = skb->tstamp; 335 fq->q.meat += skb->len; 336 fq->ecn |= ecn; 337 add_frag_mem_limit(fq->q.net, skb->truesize); 338 339 /* The first fragment. 340 * nhoffset is obtained from the first fragment, of course. 341 */ 342 if (offset == 0) { 343 fq->nhoffset = nhoff; 344 fq->q.flags |= INET_FRAG_FIRST_IN; 345 } 346 347 if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 348 fq->q.meat == fq->q.len) { 349 int res; 350 unsigned long orefdst = skb->_skb_refdst; 351 352 skb->_skb_refdst = 0UL; 353 res = ip6_frag_reasm(fq, prev, dev); 354 skb->_skb_refdst = orefdst; 355 return res; 356 } 357 358 skb_dst_drop(skb); 359 return -1; 360 361 discard_fq: 362 inet_frag_kill(&fq->q, &ip6_frags); 363 err: 364 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 365 IPSTATS_MIB_REASMFAILS); 366 kfree_skb(skb); 367 return -1; 368 } 369 370 /* 371 * Check if this packet is complete. 372 * Returns NULL on failure by any reason, and pointer 373 * to current nexthdr field in reassembled frame. 374 * 375 * It is called with locked fq, and caller must check that 376 * queue is eligible for reassembly i.e. it is not COMPLETE, 377 * the last and the first frames arrived and all the bits are here. 378 */ 379 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 380 struct net_device *dev) 381 { 382 struct net *net = container_of(fq->q.net, struct net, ipv6.frags); 383 struct sk_buff *fp, *head = fq->q.fragments; 384 int payload_len; 385 unsigned int nhoff; 386 int sum_truesize; 387 u8 ecn; 388 389 inet_frag_kill(&fq->q, &ip6_frags); 390 391 ecn = ip_frag_ecn_table[fq->ecn]; 392 if (unlikely(ecn == 0xff)) 393 goto out_fail; 394 395 /* Make the one we just received the head. */ 396 if (prev) { 397 head = prev->next; 398 fp = skb_clone(head, GFP_ATOMIC); 399 400 if (!fp) 401 goto out_oom; 402 403 fp->next = head->next; 404 if (!fp->next) 405 fq->q.fragments_tail = fp; 406 prev->next = fp; 407 408 skb_morph(head, fq->q.fragments); 409 head->next = fq->q.fragments->next; 410 411 consume_skb(fq->q.fragments); 412 fq->q.fragments = head; 413 } 414 415 WARN_ON(head == NULL); 416 WARN_ON(FRAG6_CB(head)->offset != 0); 417 418 /* Unfragmented part is taken from the first segment. */ 419 payload_len = ((head->data - skb_network_header(head)) - 420 sizeof(struct ipv6hdr) + fq->q.len - 421 sizeof(struct frag_hdr)); 422 if (payload_len > IPV6_MAXPLEN) 423 goto out_oversize; 424 425 /* Head of list must not be cloned. */ 426 if (skb_unclone(head, GFP_ATOMIC)) 427 goto out_oom; 428 429 /* If the first fragment is fragmented itself, we split 430 * it to two chunks: the first with data and paged part 431 * and the second, holding only fragments. */ 432 if (skb_has_frag_list(head)) { 433 struct sk_buff *clone; 434 int i, plen = 0; 435 436 clone = alloc_skb(0, GFP_ATOMIC); 437 if (!clone) 438 goto out_oom; 439 clone->next = head->next; 440 head->next = clone; 441 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 442 skb_frag_list_init(head); 443 for (i = 0; i < skb_shinfo(head)->nr_frags; i++) 444 plen += skb_frag_size(&skb_shinfo(head)->frags[i]); 445 clone->len = clone->data_len = head->data_len - plen; 446 head->data_len -= clone->len; 447 head->len -= clone->len; 448 clone->csum = 0; 449 clone->ip_summed = head->ip_summed; 450 add_frag_mem_limit(fq->q.net, clone->truesize); 451 } 452 453 /* We have to remove fragment header from datagram and to relocate 454 * header in order to calculate ICV correctly. */ 455 nhoff = fq->nhoffset; 456 skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; 457 memmove(head->head + sizeof(struct frag_hdr), head->head, 458 (head->data - head->head) - sizeof(struct frag_hdr)); 459 head->mac_header += sizeof(struct frag_hdr); 460 head->network_header += sizeof(struct frag_hdr); 461 462 skb_reset_transport_header(head); 463 skb_push(head, head->data - skb_network_header(head)); 464 465 sum_truesize = head->truesize; 466 for (fp = head->next; fp;) { 467 bool headstolen; 468 int delta; 469 struct sk_buff *next = fp->next; 470 471 sum_truesize += fp->truesize; 472 if (head->ip_summed != fp->ip_summed) 473 head->ip_summed = CHECKSUM_NONE; 474 else if (head->ip_summed == CHECKSUM_COMPLETE) 475 head->csum = csum_add(head->csum, fp->csum); 476 477 if (skb_try_coalesce(head, fp, &headstolen, &delta)) { 478 kfree_skb_partial(fp, headstolen); 479 } else { 480 if (!skb_shinfo(head)->frag_list) 481 skb_shinfo(head)->frag_list = fp; 482 head->data_len += fp->len; 483 head->len += fp->len; 484 head->truesize += fp->truesize; 485 } 486 fp = next; 487 } 488 sub_frag_mem_limit(fq->q.net, sum_truesize); 489 490 head->next = NULL; 491 head->dev = dev; 492 head->tstamp = fq->q.stamp; 493 ipv6_hdr(head)->payload_len = htons(payload_len); 494 ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); 495 IP6CB(head)->nhoff = nhoff; 496 IP6CB(head)->flags |= IP6SKB_FRAGMENTED; 497 498 /* Yes, and fold redundant checksum back. 8) */ 499 if (head->ip_summed == CHECKSUM_COMPLETE) 500 head->csum = csum_partial(skb_network_header(head), 501 skb_network_header_len(head), 502 head->csum); 503 504 rcu_read_lock(); 505 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); 506 rcu_read_unlock(); 507 fq->q.fragments = NULL; 508 fq->q.fragments_tail = NULL; 509 return 1; 510 511 out_oversize: 512 net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); 513 goto out_fail; 514 out_oom: 515 net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); 516 out_fail: 517 rcu_read_lock(); 518 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 519 rcu_read_unlock(); 520 return -1; 521 } 522 523 static int ipv6_frag_rcv(struct sk_buff *skb) 524 { 525 struct frag_hdr *fhdr; 526 struct frag_queue *fq; 527 const struct ipv6hdr *hdr = ipv6_hdr(skb); 528 struct net *net = dev_net(skb_dst(skb)->dev); 529 530 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED) 531 goto fail_hdr; 532 533 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); 534 535 /* Jumbo payload inhibits frag. header */ 536 if (hdr->payload_len == 0) 537 goto fail_hdr; 538 539 if (!pskb_may_pull(skb, (skb_transport_offset(skb) + 540 sizeof(struct frag_hdr)))) 541 goto fail_hdr; 542 543 hdr = ipv6_hdr(skb); 544 fhdr = (struct frag_hdr *)skb_transport_header(skb); 545 546 if (!(fhdr->frag_off & htons(0xFFF9))) { 547 /* It is not a fragmented frame */ 548 skb->transport_header += sizeof(struct frag_hdr); 549 IP6_INC_STATS_BH(net, 550 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); 551 552 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); 553 IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; 554 return 1; 555 } 556 557 fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, 558 skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr)); 559 if (fq) { 560 int ret; 561 562 spin_lock(&fq->q.lock); 563 564 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); 565 566 spin_unlock(&fq->q.lock); 567 inet_frag_put(&fq->q, &ip6_frags); 568 return ret; 569 } 570 571 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); 572 kfree_skb(skb); 573 return -1; 574 575 fail_hdr: 576 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), 577 IPSTATS_MIB_INHDRERRORS); 578 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); 579 return -1; 580 } 581 582 static const struct inet6_protocol frag_protocol = { 583 .handler = ipv6_frag_rcv, 584 .flags = INET6_PROTO_NOPOLICY, 585 }; 586 587 #ifdef CONFIG_SYSCTL 588 static int zero; 589 590 static struct ctl_table ip6_frags_ns_ctl_table[] = { 591 { 592 .procname = "ip6frag_high_thresh", 593 .data = &init_net.ipv6.frags.high_thresh, 594 .maxlen = sizeof(int), 595 .mode = 0644, 596 .proc_handler = proc_dointvec_minmax, 597 .extra1 = &init_net.ipv6.frags.low_thresh 598 }, 599 { 600 .procname = "ip6frag_low_thresh", 601 .data = &init_net.ipv6.frags.low_thresh, 602 .maxlen = sizeof(int), 603 .mode = 0644, 604 .proc_handler = proc_dointvec_minmax, 605 .extra1 = &zero, 606 .extra2 = &init_net.ipv6.frags.high_thresh 607 }, 608 { 609 .procname = "ip6frag_time", 610 .data = &init_net.ipv6.frags.timeout, 611 .maxlen = sizeof(int), 612 .mode = 0644, 613 .proc_handler = proc_dointvec_jiffies, 614 }, 615 { } 616 }; 617 618 /* secret interval has been deprecated */ 619 static int ip6_frags_secret_interval_unused; 620 static struct ctl_table ip6_frags_ctl_table[] = { 621 { 622 .procname = "ip6frag_secret_interval", 623 .data = &ip6_frags_secret_interval_unused, 624 .maxlen = sizeof(int), 625 .mode = 0644, 626 .proc_handler = proc_dointvec_jiffies, 627 }, 628 { } 629 }; 630 631 static int __net_init ip6_frags_ns_sysctl_register(struct net *net) 632 { 633 struct ctl_table *table; 634 struct ctl_table_header *hdr; 635 636 table = ip6_frags_ns_ctl_table; 637 if (!net_eq(net, &init_net)) { 638 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); 639 if (!table) 640 goto err_alloc; 641 642 table[0].data = &net->ipv6.frags.high_thresh; 643 table[0].extra1 = &net->ipv6.frags.low_thresh; 644 table[0].extra2 = &init_net.ipv6.frags.high_thresh; 645 table[1].data = &net->ipv6.frags.low_thresh; 646 table[1].extra2 = &net->ipv6.frags.high_thresh; 647 table[2].data = &net->ipv6.frags.timeout; 648 649 /* Don't export sysctls to unprivileged users */ 650 if (net->user_ns != &init_user_ns) 651 table[0].procname = NULL; 652 } 653 654 hdr = register_net_sysctl(net, "net/ipv6", table); 655 if (!hdr) 656 goto err_reg; 657 658 net->ipv6.sysctl.frags_hdr = hdr; 659 return 0; 660 661 err_reg: 662 if (!net_eq(net, &init_net)) 663 kfree(table); 664 err_alloc: 665 return -ENOMEM; 666 } 667 668 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) 669 { 670 struct ctl_table *table; 671 672 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; 673 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); 674 if (!net_eq(net, &init_net)) 675 kfree(table); 676 } 677 678 static struct ctl_table_header *ip6_ctl_header; 679 680 static int ip6_frags_sysctl_register(void) 681 { 682 ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", 683 ip6_frags_ctl_table); 684 return ip6_ctl_header == NULL ? -ENOMEM : 0; 685 } 686 687 static void ip6_frags_sysctl_unregister(void) 688 { 689 unregister_net_sysctl_table(ip6_ctl_header); 690 } 691 #else 692 static int ip6_frags_ns_sysctl_register(struct net *net) 693 { 694 return 0; 695 } 696 697 static void ip6_frags_ns_sysctl_unregister(struct net *net) 698 { 699 } 700 701 static int ip6_frags_sysctl_register(void) 702 { 703 return 0; 704 } 705 706 static void ip6_frags_sysctl_unregister(void) 707 { 708 } 709 #endif 710 711 static int __net_init ipv6_frags_init_net(struct net *net) 712 { 713 int res; 714 715 net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; 716 net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; 717 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; 718 719 res = inet_frags_init_net(&net->ipv6.frags); 720 if (res) 721 return res; 722 res = ip6_frags_ns_sysctl_register(net); 723 if (res) 724 inet_frags_uninit_net(&net->ipv6.frags); 725 return res; 726 } 727 728 static void __net_exit ipv6_frags_exit_net(struct net *net) 729 { 730 ip6_frags_ns_sysctl_unregister(net); 731 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); 732 } 733 734 static struct pernet_operations ip6_frags_ops = { 735 .init = ipv6_frags_init_net, 736 .exit = ipv6_frags_exit_net, 737 }; 738 739 int __init ipv6_frag_init(void) 740 { 741 int ret; 742 743 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); 744 if (ret) 745 goto out; 746 747 ret = ip6_frags_sysctl_register(); 748 if (ret) 749 goto err_sysctl; 750 751 ret = register_pernet_subsys(&ip6_frags_ops); 752 if (ret) 753 goto err_pernet; 754 755 ip6_frags.hashfn = ip6_hashfn; 756 ip6_frags.constructor = ip6_frag_init; 757 ip6_frags.destructor = NULL; 758 ip6_frags.qsize = sizeof(struct frag_queue); 759 ip6_frags.match = ip6_frag_match; 760 ip6_frags.frag_expire = ip6_frag_expire; 761 ip6_frags.frags_cache_name = ip6_frag_cache_name; 762 ret = inet_frags_init(&ip6_frags); 763 if (ret) 764 goto err_pernet; 765 out: 766 return ret; 767 768 err_pernet: 769 ip6_frags_sysctl_unregister(); 770 err_sysctl: 771 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 772 goto out; 773 } 774 775 void ipv6_frag_exit(void) 776 { 777 inet_frags_fini(&ip6_frags); 778 ip6_frags_sysctl_unregister(); 779 unregister_pernet_subsys(&ip6_frags_ops); 780 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 781 } 782