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 45 #include <net/sock.h> 46 #include <net/snmp.h> 47 48 #include <net/ipv6.h> 49 #include <net/ip6_route.h> 50 #include <net/protocol.h> 51 #include <net/transp_v6.h> 52 #include <net/rawv6.h> 53 #include <net/ndisc.h> 54 #include <net/addrconf.h> 55 #include <net/inet_frag.h> 56 57 struct ip6frag_skb_cb 58 { 59 struct inet6_skb_parm h; 60 int offset; 61 }; 62 63 #define FRAG6_CB(skb) ((struct ip6frag_skb_cb*)((skb)->cb)) 64 65 66 /* 67 * Equivalent of ipv4 struct ipq 68 */ 69 70 struct frag_queue 71 { 72 struct inet_frag_queue q; 73 74 __be32 id; /* fragment id */ 75 struct in6_addr saddr; 76 struct in6_addr daddr; 77 78 int iif; 79 unsigned int csum; 80 __u16 nhoffset; 81 }; 82 83 static struct inet_frags ip6_frags; 84 85 int ip6_frag_nqueues(struct net *net) 86 { 87 return net->ipv6.frags.nqueues; 88 } 89 90 int ip6_frag_mem(struct net *net) 91 { 92 return atomic_read(&net->ipv6.frags.mem); 93 } 94 95 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 96 struct net_device *dev); 97 98 /* 99 * callers should be careful not to use the hash value outside the ipfrag_lock 100 * as doing so could race with ipfrag_hash_rnd being recalculated. 101 */ 102 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, 103 const struct in6_addr *daddr, u32 rnd) 104 { 105 u32 a, b, c; 106 107 a = (__force u32)saddr->s6_addr32[0]; 108 b = (__force u32)saddr->s6_addr32[1]; 109 c = (__force u32)saddr->s6_addr32[2]; 110 111 a += JHASH_GOLDEN_RATIO; 112 b += JHASH_GOLDEN_RATIO; 113 c += rnd; 114 __jhash_mix(a, b, c); 115 116 a += (__force u32)saddr->s6_addr32[3]; 117 b += (__force u32)daddr->s6_addr32[0]; 118 c += (__force u32)daddr->s6_addr32[1]; 119 __jhash_mix(a, b, c); 120 121 a += (__force u32)daddr->s6_addr32[2]; 122 b += (__force u32)daddr->s6_addr32[3]; 123 c += (__force u32)id; 124 __jhash_mix(a, b, c); 125 126 return c & (INETFRAGS_HASHSZ - 1); 127 } 128 EXPORT_SYMBOL_GPL(inet6_hash_frag); 129 130 static unsigned int ip6_hashfn(struct inet_frag_queue *q) 131 { 132 struct frag_queue *fq; 133 134 fq = container_of(q, struct frag_queue, q); 135 return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd); 136 } 137 138 int ip6_frag_match(struct inet_frag_queue *q, void *a) 139 { 140 struct frag_queue *fq; 141 struct ip6_create_arg *arg = a; 142 143 fq = container_of(q, struct frag_queue, q); 144 return (fq->id == arg->id && 145 ipv6_addr_equal(&fq->saddr, arg->src) && 146 ipv6_addr_equal(&fq->daddr, arg->dst)); 147 } 148 EXPORT_SYMBOL(ip6_frag_match); 149 150 /* Memory Tracking Functions. */ 151 static inline void frag_kfree_skb(struct netns_frags *nf, 152 struct sk_buff *skb, int *work) 153 { 154 if (work) 155 *work -= skb->truesize; 156 atomic_sub(skb->truesize, &nf->mem); 157 kfree_skb(skb); 158 } 159 160 void ip6_frag_init(struct inet_frag_queue *q, void *a) 161 { 162 struct frag_queue *fq = container_of(q, struct frag_queue, q); 163 struct ip6_create_arg *arg = a; 164 165 fq->id = arg->id; 166 ipv6_addr_copy(&fq->saddr, arg->src); 167 ipv6_addr_copy(&fq->daddr, arg->dst); 168 } 169 EXPORT_SYMBOL(ip6_frag_init); 170 171 /* Destruction primitives. */ 172 173 static __inline__ void fq_put(struct frag_queue *fq) 174 { 175 inet_frag_put(&fq->q, &ip6_frags); 176 } 177 178 /* Kill fq entry. It is not destroyed immediately, 179 * because caller (and someone more) holds reference count. 180 */ 181 static __inline__ void fq_kill(struct frag_queue *fq) 182 { 183 inet_frag_kill(&fq->q, &ip6_frags); 184 } 185 186 static void ip6_evictor(struct net *net, struct inet6_dev *idev) 187 { 188 int evicted; 189 190 evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags); 191 if (evicted) 192 IP6_ADD_STATS_BH(idev, IPSTATS_MIB_REASMFAILS, evicted); 193 } 194 195 static void ip6_frag_expire(unsigned long data) 196 { 197 struct frag_queue *fq; 198 struct net_device *dev = NULL; 199 struct net *net; 200 201 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); 202 203 spin_lock(&fq->q.lock); 204 205 if (fq->q.last_in & INET_FRAG_COMPLETE) 206 goto out; 207 208 fq_kill(fq); 209 210 net = container_of(fq->q.net, struct net, ipv6.frags); 211 dev = dev_get_by_index(net, fq->iif); 212 if (!dev) 213 goto out; 214 215 rcu_read_lock(); 216 IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); 217 IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 218 rcu_read_unlock(); 219 220 /* Don't send error if the first segment did not arrive. */ 221 if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments) 222 goto out; 223 224 /* 225 But use as source device on which LAST ARRIVED 226 segment was received. And do not use fq->dev 227 pointer directly, device might already disappeared. 228 */ 229 fq->q.fragments->dev = dev; 230 icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev); 231 out: 232 if (dev) 233 dev_put(dev); 234 spin_unlock(&fq->q.lock); 235 fq_put(fq); 236 } 237 238 static __inline__ struct frag_queue * 239 fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst, 240 struct inet6_dev *idev) 241 { 242 struct inet_frag_queue *q; 243 struct ip6_create_arg arg; 244 unsigned int hash; 245 246 arg.id = id; 247 arg.src = src; 248 arg.dst = dst; 249 250 read_lock(&ip6_frags.lock); 251 hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd); 252 253 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); 254 if (q == NULL) 255 goto oom; 256 257 return container_of(q, struct frag_queue, q); 258 259 oom: 260 IP6_INC_STATS_BH(idev, IPSTATS_MIB_REASMFAILS); 261 return NULL; 262 } 263 264 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, 265 struct frag_hdr *fhdr, int nhoff) 266 { 267 struct sk_buff *prev, *next; 268 struct net_device *dev; 269 int offset, end; 270 271 if (fq->q.last_in & INET_FRAG_COMPLETE) 272 goto err; 273 274 offset = ntohs(fhdr->frag_off) & ~0x7; 275 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - 276 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); 277 278 if ((unsigned int)end > IPV6_MAXPLEN) { 279 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), 280 IPSTATS_MIB_INHDRERRORS); 281 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 282 ((u8 *)&fhdr->frag_off - 283 skb_network_header(skb))); 284 return -1; 285 } 286 287 if (skb->ip_summed == CHECKSUM_COMPLETE) { 288 const unsigned char *nh = skb_network_header(skb); 289 skb->csum = csum_sub(skb->csum, 290 csum_partial(nh, (u8 *)(fhdr + 1) - nh, 291 0)); 292 } 293 294 /* Is this the final fragment? */ 295 if (!(fhdr->frag_off & htons(IP6_MF))) { 296 /* If we already have some bits beyond end 297 * or have different end, the segment is corrupted. 298 */ 299 if (end < fq->q.len || 300 ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) 301 goto err; 302 fq->q.last_in |= INET_FRAG_LAST_IN; 303 fq->q.len = end; 304 } else { 305 /* Check if the fragment is rounded to 8 bytes. 306 * Required by the RFC. 307 */ 308 if (end & 0x7) { 309 /* RFC2460 says always send parameter problem in 310 * this case. -DaveM 311 */ 312 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), 313 IPSTATS_MIB_INHDRERRORS); 314 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 315 offsetof(struct ipv6hdr, payload_len)); 316 return -1; 317 } 318 if (end > fq->q.len) { 319 /* Some bits beyond end -> corruption. */ 320 if (fq->q.last_in & INET_FRAG_LAST_IN) 321 goto err; 322 fq->q.len = end; 323 } 324 } 325 326 if (end == offset) 327 goto err; 328 329 /* Point into the IP datagram 'data' part. */ 330 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) 331 goto err; 332 333 if (pskb_trim_rcsum(skb, end - offset)) 334 goto err; 335 336 /* Find out which fragments are in front and at the back of us 337 * in the chain of fragments so far. We must know where to put 338 * this fragment, right? 339 */ 340 prev = NULL; 341 for(next = fq->q.fragments; next != NULL; next = next->next) { 342 if (FRAG6_CB(next)->offset >= offset) 343 break; /* bingo! */ 344 prev = next; 345 } 346 347 /* We found where to put this one. Check for overlap with 348 * preceding fragment, and, if needed, align things so that 349 * any overlaps are eliminated. 350 */ 351 if (prev) { 352 int i = (FRAG6_CB(prev)->offset + prev->len) - offset; 353 354 if (i > 0) { 355 offset += i; 356 if (end <= offset) 357 goto err; 358 if (!pskb_pull(skb, i)) 359 goto err; 360 if (skb->ip_summed != CHECKSUM_UNNECESSARY) 361 skb->ip_summed = CHECKSUM_NONE; 362 } 363 } 364 365 /* Look for overlap with succeeding segments. 366 * If we can merge fragments, do it. 367 */ 368 while (next && FRAG6_CB(next)->offset < end) { 369 int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */ 370 371 if (i < next->len) { 372 /* Eat head of the next overlapped fragment 373 * and leave the loop. The next ones cannot overlap. 374 */ 375 if (!pskb_pull(next, i)) 376 goto err; 377 FRAG6_CB(next)->offset += i; /* next fragment */ 378 fq->q.meat -= i; 379 if (next->ip_summed != CHECKSUM_UNNECESSARY) 380 next->ip_summed = CHECKSUM_NONE; 381 break; 382 } else { 383 struct sk_buff *free_it = next; 384 385 /* Old fragment is completely overridden with 386 * new one drop it. 387 */ 388 next = next->next; 389 390 if (prev) 391 prev->next = next; 392 else 393 fq->q.fragments = next; 394 395 fq->q.meat -= free_it->len; 396 frag_kfree_skb(fq->q.net, free_it, NULL); 397 } 398 } 399 400 FRAG6_CB(skb)->offset = offset; 401 402 /* Insert this fragment in the chain of fragments. */ 403 skb->next = next; 404 if (prev) 405 prev->next = skb; 406 else 407 fq->q.fragments = skb; 408 409 dev = skb->dev; 410 if (dev) { 411 fq->iif = dev->ifindex; 412 skb->dev = NULL; 413 } 414 fq->q.stamp = skb->tstamp; 415 fq->q.meat += skb->len; 416 atomic_add(skb->truesize, &fq->q.net->mem); 417 418 /* The first fragment. 419 * nhoffset is obtained from the first fragment, of course. 420 */ 421 if (offset == 0) { 422 fq->nhoffset = nhoff; 423 fq->q.last_in |= INET_FRAG_FIRST_IN; 424 } 425 426 if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 427 fq->q.meat == fq->q.len) 428 return ip6_frag_reasm(fq, prev, dev); 429 430 write_lock(&ip6_frags.lock); 431 list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list); 432 write_unlock(&ip6_frags.lock); 433 return -1; 434 435 err: 436 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS); 437 kfree_skb(skb); 438 return -1; 439 } 440 441 /* 442 * Check if this packet is complete. 443 * Returns NULL on failure by any reason, and pointer 444 * to current nexthdr field in reassembled frame. 445 * 446 * It is called with locked fq, and caller must check that 447 * queue is eligible for reassembly i.e. it is not COMPLETE, 448 * the last and the first frames arrived and all the bits are here. 449 */ 450 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 451 struct net_device *dev) 452 { 453 struct sk_buff *fp, *head = fq->q.fragments; 454 int payload_len; 455 unsigned int nhoff; 456 457 fq_kill(fq); 458 459 /* Make the one we just received the head. */ 460 if (prev) { 461 head = prev->next; 462 fp = skb_clone(head, GFP_ATOMIC); 463 464 if (!fp) 465 goto out_oom; 466 467 fp->next = head->next; 468 prev->next = fp; 469 470 skb_morph(head, fq->q.fragments); 471 head->next = fq->q.fragments->next; 472 473 kfree_skb(fq->q.fragments); 474 fq->q.fragments = head; 475 } 476 477 WARN_ON(head == NULL); 478 WARN_ON(FRAG6_CB(head)->offset != 0); 479 480 /* Unfragmented part is taken from the first segment. */ 481 payload_len = ((head->data - skb_network_header(head)) - 482 sizeof(struct ipv6hdr) + fq->q.len - 483 sizeof(struct frag_hdr)); 484 if (payload_len > IPV6_MAXPLEN) 485 goto out_oversize; 486 487 /* Head of list must not be cloned. */ 488 if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) 489 goto out_oom; 490 491 /* If the first fragment is fragmented itself, we split 492 * it to two chunks: the first with data and paged part 493 * and the second, holding only fragments. */ 494 if (skb_shinfo(head)->frag_list) { 495 struct sk_buff *clone; 496 int i, plen = 0; 497 498 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) 499 goto out_oom; 500 clone->next = head->next; 501 head->next = clone; 502 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 503 skb_shinfo(head)->frag_list = NULL; 504 for (i=0; i<skb_shinfo(head)->nr_frags; i++) 505 plen += skb_shinfo(head)->frags[i].size; 506 clone->len = clone->data_len = head->data_len - plen; 507 head->data_len -= clone->len; 508 head->len -= clone->len; 509 clone->csum = 0; 510 clone->ip_summed = head->ip_summed; 511 atomic_add(clone->truesize, &fq->q.net->mem); 512 } 513 514 /* We have to remove fragment header from datagram and to relocate 515 * header in order to calculate ICV correctly. */ 516 nhoff = fq->nhoffset; 517 skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; 518 memmove(head->head + sizeof(struct frag_hdr), head->head, 519 (head->data - head->head) - sizeof(struct frag_hdr)); 520 head->mac_header += sizeof(struct frag_hdr); 521 head->network_header += sizeof(struct frag_hdr); 522 523 skb_shinfo(head)->frag_list = head->next; 524 skb_reset_transport_header(head); 525 skb_push(head, head->data - skb_network_header(head)); 526 atomic_sub(head->truesize, &fq->q.net->mem); 527 528 for (fp=head->next; fp; fp = fp->next) { 529 head->data_len += fp->len; 530 head->len += fp->len; 531 if (head->ip_summed != fp->ip_summed) 532 head->ip_summed = CHECKSUM_NONE; 533 else if (head->ip_summed == CHECKSUM_COMPLETE) 534 head->csum = csum_add(head->csum, fp->csum); 535 head->truesize += fp->truesize; 536 atomic_sub(fp->truesize, &fq->q.net->mem); 537 } 538 539 head->next = NULL; 540 head->dev = dev; 541 head->tstamp = fq->q.stamp; 542 ipv6_hdr(head)->payload_len = htons(payload_len); 543 IP6CB(head)->nhoff = nhoff; 544 545 /* Yes, and fold redundant checksum back. 8) */ 546 if (head->ip_summed == CHECKSUM_COMPLETE) 547 head->csum = csum_partial(skb_network_header(head), 548 skb_network_header_len(head), 549 head->csum); 550 551 rcu_read_lock(); 552 IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMOKS); 553 rcu_read_unlock(); 554 fq->q.fragments = NULL; 555 return 1; 556 557 out_oversize: 558 if (net_ratelimit()) 559 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len); 560 goto out_fail; 561 out_oom: 562 if (net_ratelimit()) 563 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n"); 564 out_fail: 565 rcu_read_lock(); 566 IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 567 rcu_read_unlock(); 568 return -1; 569 } 570 571 static int ipv6_frag_rcv(struct sk_buff *skb) 572 { 573 struct frag_hdr *fhdr; 574 struct frag_queue *fq; 575 struct ipv6hdr *hdr = ipv6_hdr(skb); 576 struct net *net; 577 578 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMREQDS); 579 580 /* Jumbo payload inhibits frag. header */ 581 if (hdr->payload_len==0) 582 goto fail_hdr; 583 584 if (!pskb_may_pull(skb, (skb_transport_offset(skb) + 585 sizeof(struct frag_hdr)))) 586 goto fail_hdr; 587 588 hdr = ipv6_hdr(skb); 589 fhdr = (struct frag_hdr *)skb_transport_header(skb); 590 591 if (!(fhdr->frag_off & htons(0xFFF9))) { 592 /* It is not a fragmented frame */ 593 skb->transport_header += sizeof(struct frag_hdr); 594 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMOKS); 595 596 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); 597 return 1; 598 } 599 600 net = dev_net(skb->dev); 601 if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh) 602 ip6_evictor(net, ip6_dst_idev(skb->dst)); 603 604 if ((fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, 605 ip6_dst_idev(skb->dst))) != NULL) { 606 int ret; 607 608 spin_lock(&fq->q.lock); 609 610 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); 611 612 spin_unlock(&fq->q.lock); 613 fq_put(fq); 614 return ret; 615 } 616 617 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS); 618 kfree_skb(skb); 619 return -1; 620 621 fail_hdr: 622 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); 623 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); 624 return -1; 625 } 626 627 static struct inet6_protocol frag_protocol = 628 { 629 .handler = ipv6_frag_rcv, 630 .flags = INET6_PROTO_NOPOLICY, 631 }; 632 633 #ifdef CONFIG_SYSCTL 634 static struct ctl_table ip6_frags_ns_ctl_table[] = { 635 { 636 .ctl_name = NET_IPV6_IP6FRAG_HIGH_THRESH, 637 .procname = "ip6frag_high_thresh", 638 .data = &init_net.ipv6.frags.high_thresh, 639 .maxlen = sizeof(int), 640 .mode = 0644, 641 .proc_handler = &proc_dointvec 642 }, 643 { 644 .ctl_name = NET_IPV6_IP6FRAG_LOW_THRESH, 645 .procname = "ip6frag_low_thresh", 646 .data = &init_net.ipv6.frags.low_thresh, 647 .maxlen = sizeof(int), 648 .mode = 0644, 649 .proc_handler = &proc_dointvec 650 }, 651 { 652 .ctl_name = NET_IPV6_IP6FRAG_TIME, 653 .procname = "ip6frag_time", 654 .data = &init_net.ipv6.frags.timeout, 655 .maxlen = sizeof(int), 656 .mode = 0644, 657 .proc_handler = &proc_dointvec_jiffies, 658 .strategy = &sysctl_jiffies, 659 }, 660 { } 661 }; 662 663 static struct ctl_table ip6_frags_ctl_table[] = { 664 { 665 .ctl_name = NET_IPV6_IP6FRAG_SECRET_INTERVAL, 666 .procname = "ip6frag_secret_interval", 667 .data = &ip6_frags.secret_interval, 668 .maxlen = sizeof(int), 669 .mode = 0644, 670 .proc_handler = &proc_dointvec_jiffies, 671 .strategy = &sysctl_jiffies 672 }, 673 { } 674 }; 675 676 static int ip6_frags_ns_sysctl_register(struct net *net) 677 { 678 struct ctl_table *table; 679 struct ctl_table_header *hdr; 680 681 table = ip6_frags_ns_ctl_table; 682 if (net != &init_net) { 683 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); 684 if (table == NULL) 685 goto err_alloc; 686 687 table[0].data = &net->ipv6.frags.high_thresh; 688 table[1].data = &net->ipv6.frags.low_thresh; 689 table[2].data = &net->ipv6.frags.timeout; 690 } 691 692 hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table); 693 if (hdr == NULL) 694 goto err_reg; 695 696 net->ipv6.sysctl.frags_hdr = hdr; 697 return 0; 698 699 err_reg: 700 if (net != &init_net) 701 kfree(table); 702 err_alloc: 703 return -ENOMEM; 704 } 705 706 static void ip6_frags_ns_sysctl_unregister(struct net *net) 707 { 708 struct ctl_table *table; 709 710 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; 711 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); 712 kfree(table); 713 } 714 715 static struct ctl_table_header *ip6_ctl_header; 716 717 static int ip6_frags_sysctl_register(void) 718 { 719 ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path, 720 ip6_frags_ctl_table); 721 return ip6_ctl_header == NULL ? -ENOMEM : 0; 722 } 723 724 static void ip6_frags_sysctl_unregister(void) 725 { 726 unregister_net_sysctl_table(ip6_ctl_header); 727 } 728 #else 729 static inline int ip6_frags_ns_sysctl_register(struct net *net) 730 { 731 return 0; 732 } 733 734 static inline void ip6_frags_ns_sysctl_unregister(struct net *net) 735 { 736 } 737 738 static inline int ip6_frags_sysctl_register(void) 739 { 740 return 0; 741 } 742 743 static inline void ip6_frags_sysctl_unregister(void) 744 { 745 } 746 #endif 747 748 static int ipv6_frags_init_net(struct net *net) 749 { 750 net->ipv6.frags.high_thresh = 256 * 1024; 751 net->ipv6.frags.low_thresh = 192 * 1024; 752 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; 753 754 inet_frags_init_net(&net->ipv6.frags); 755 756 return ip6_frags_ns_sysctl_register(net); 757 } 758 759 static void ipv6_frags_exit_net(struct net *net) 760 { 761 ip6_frags_ns_sysctl_unregister(net); 762 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); 763 } 764 765 static struct pernet_operations ip6_frags_ops = { 766 .init = ipv6_frags_init_net, 767 .exit = ipv6_frags_exit_net, 768 }; 769 770 int __init ipv6_frag_init(void) 771 { 772 int ret; 773 774 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); 775 if (ret) 776 goto out; 777 778 ret = ip6_frags_sysctl_register(); 779 if (ret) 780 goto err_sysctl; 781 782 ret = register_pernet_subsys(&ip6_frags_ops); 783 if (ret) 784 goto err_pernet; 785 786 ip6_frags.hashfn = ip6_hashfn; 787 ip6_frags.constructor = ip6_frag_init; 788 ip6_frags.destructor = NULL; 789 ip6_frags.skb_free = NULL; 790 ip6_frags.qsize = sizeof(struct frag_queue); 791 ip6_frags.match = ip6_frag_match; 792 ip6_frags.frag_expire = ip6_frag_expire; 793 ip6_frags.secret_interval = 10 * 60 * HZ; 794 inet_frags_init(&ip6_frags); 795 out: 796 return ret; 797 798 err_pernet: 799 ip6_frags_sysctl_unregister(); 800 err_sysctl: 801 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 802 goto out; 803 } 804 805 void ipv6_frag_exit(void) 806 { 807 inet_frags_fini(&ip6_frags); 808 ip6_frags_sysctl_unregister(); 809 unregister_pernet_subsys(&ip6_frags_ops); 810 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 811 } 812