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 static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr, 103 struct in6_addr *daddr) 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 += ip6_frags.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 } 128 129 static unsigned int ip6_hashfn(struct inet_frag_queue *q) 130 { 131 struct frag_queue *fq; 132 133 fq = container_of(q, struct frag_queue, q); 134 return ip6qhashfn(fq->id, &fq->saddr, &fq->daddr); 135 } 136 137 int ip6_frag_match(struct inet_frag_queue *q, void *a) 138 { 139 struct frag_queue *fq; 140 struct ip6_create_arg *arg = a; 141 142 fq = container_of(q, struct frag_queue, q); 143 return (fq->id == arg->id && 144 ipv6_addr_equal(&fq->saddr, arg->src) && 145 ipv6_addr_equal(&fq->daddr, arg->dst)); 146 } 147 EXPORT_SYMBOL(ip6_frag_match); 148 149 /* Memory Tracking Functions. */ 150 static inline void frag_kfree_skb(struct netns_frags *nf, 151 struct sk_buff *skb, int *work) 152 { 153 if (work) 154 *work -= skb->truesize; 155 atomic_sub(skb->truesize, &nf->mem); 156 kfree_skb(skb); 157 } 158 159 void ip6_frag_init(struct inet_frag_queue *q, void *a) 160 { 161 struct frag_queue *fq = container_of(q, struct frag_queue, q); 162 struct ip6_create_arg *arg = a; 163 164 fq->id = arg->id; 165 ipv6_addr_copy(&fq->saddr, arg->src); 166 ipv6_addr_copy(&fq->daddr, arg->dst); 167 } 168 EXPORT_SYMBOL(ip6_frag_init); 169 170 /* Destruction primitives. */ 171 172 static __inline__ void fq_put(struct frag_queue *fq) 173 { 174 inet_frag_put(&fq->q, &ip6_frags); 175 } 176 177 /* Kill fq entry. It is not destroyed immediately, 178 * because caller (and someone more) holds reference count. 179 */ 180 static __inline__ void fq_kill(struct frag_queue *fq) 181 { 182 inet_frag_kill(&fq->q, &ip6_frags); 183 } 184 185 static void ip6_evictor(struct net *net, struct inet6_dev *idev) 186 { 187 int evicted; 188 189 evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags); 190 if (evicted) 191 IP6_ADD_STATS_BH(idev, IPSTATS_MIB_REASMFAILS, evicted); 192 } 193 194 static void ip6_frag_expire(unsigned long data) 195 { 196 struct frag_queue *fq; 197 struct net_device *dev = NULL; 198 struct net *net; 199 200 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); 201 202 spin_lock(&fq->q.lock); 203 204 if (fq->q.last_in & INET_FRAG_COMPLETE) 205 goto out; 206 207 fq_kill(fq); 208 209 net = container_of(fq->q.net, struct net, ipv6.frags); 210 dev = dev_get_by_index(net, fq->iif); 211 if (!dev) 212 goto out; 213 214 rcu_read_lock(); 215 IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); 216 IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 217 rcu_read_unlock(); 218 219 /* Don't send error if the first segment did not arrive. */ 220 if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments) 221 goto out; 222 223 /* 224 But use as source device on which LAST ARRIVED 225 segment was received. And do not use fq->dev 226 pointer directly, device might already disappeared. 227 */ 228 fq->q.fragments->dev = dev; 229 icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev); 230 out: 231 if (dev) 232 dev_put(dev); 233 spin_unlock(&fq->q.lock); 234 fq_put(fq); 235 } 236 237 static __inline__ struct frag_queue * 238 fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst, 239 struct inet6_dev *idev) 240 { 241 struct inet_frag_queue *q; 242 struct ip6_create_arg arg; 243 unsigned int hash; 244 245 arg.id = id; 246 arg.src = src; 247 arg.dst = dst; 248 249 read_lock(&ip6_frags.lock); 250 hash = ip6qhashfn(id, src, dst); 251 252 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); 253 if (q == NULL) 254 goto oom; 255 256 return container_of(q, struct frag_queue, q); 257 258 oom: 259 IP6_INC_STATS_BH(idev, IPSTATS_MIB_REASMFAILS); 260 return NULL; 261 } 262 263 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, 264 struct frag_hdr *fhdr, int nhoff) 265 { 266 struct sk_buff *prev, *next; 267 struct net_device *dev; 268 int offset, end; 269 270 if (fq->q.last_in & INET_FRAG_COMPLETE) 271 goto err; 272 273 offset = ntohs(fhdr->frag_off) & ~0x7; 274 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - 275 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); 276 277 if ((unsigned int)end > IPV6_MAXPLEN) { 278 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), 279 IPSTATS_MIB_INHDRERRORS); 280 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 281 ((u8 *)&fhdr->frag_off - 282 skb_network_header(skb))); 283 return -1; 284 } 285 286 if (skb->ip_summed == CHECKSUM_COMPLETE) { 287 const unsigned char *nh = skb_network_header(skb); 288 skb->csum = csum_sub(skb->csum, 289 csum_partial(nh, (u8 *)(fhdr + 1) - nh, 290 0)); 291 } 292 293 /* Is this the final fragment? */ 294 if (!(fhdr->frag_off & htons(IP6_MF))) { 295 /* If we already have some bits beyond end 296 * or have different end, the segment is corrupted. 297 */ 298 if (end < fq->q.len || 299 ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) 300 goto err; 301 fq->q.last_in |= INET_FRAG_LAST_IN; 302 fq->q.len = end; 303 } else { 304 /* Check if the fragment is rounded to 8 bytes. 305 * Required by the RFC. 306 */ 307 if (end & 0x7) { 308 /* RFC2460 says always send parameter problem in 309 * this case. -DaveM 310 */ 311 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), 312 IPSTATS_MIB_INHDRERRORS); 313 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 314 offsetof(struct ipv6hdr, payload_len)); 315 return -1; 316 } 317 if (end > fq->q.len) { 318 /* Some bits beyond end -> corruption. */ 319 if (fq->q.last_in & INET_FRAG_LAST_IN) 320 goto err; 321 fq->q.len = end; 322 } 323 } 324 325 if (end == offset) 326 goto err; 327 328 /* Point into the IP datagram 'data' part. */ 329 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) 330 goto err; 331 332 if (pskb_trim_rcsum(skb, end - offset)) 333 goto err; 334 335 /* Find out which fragments are in front and at the back of us 336 * in the chain of fragments so far. We must know where to put 337 * this fragment, right? 338 */ 339 prev = NULL; 340 for(next = fq->q.fragments; next != NULL; next = next->next) { 341 if (FRAG6_CB(next)->offset >= offset) 342 break; /* bingo! */ 343 prev = next; 344 } 345 346 /* We found where to put this one. Check for overlap with 347 * preceding fragment, and, if needed, align things so that 348 * any overlaps are eliminated. 349 */ 350 if (prev) { 351 int i = (FRAG6_CB(prev)->offset + prev->len) - offset; 352 353 if (i > 0) { 354 offset += i; 355 if (end <= offset) 356 goto err; 357 if (!pskb_pull(skb, i)) 358 goto err; 359 if (skb->ip_summed != CHECKSUM_UNNECESSARY) 360 skb->ip_summed = CHECKSUM_NONE; 361 } 362 } 363 364 /* Look for overlap with succeeding segments. 365 * If we can merge fragments, do it. 366 */ 367 while (next && FRAG6_CB(next)->offset < end) { 368 int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */ 369 370 if (i < next->len) { 371 /* Eat head of the next overlapped fragment 372 * and leave the loop. The next ones cannot overlap. 373 */ 374 if (!pskb_pull(next, i)) 375 goto err; 376 FRAG6_CB(next)->offset += i; /* next fragment */ 377 fq->q.meat -= i; 378 if (next->ip_summed != CHECKSUM_UNNECESSARY) 379 next->ip_summed = CHECKSUM_NONE; 380 break; 381 } else { 382 struct sk_buff *free_it = next; 383 384 /* Old fragment is completely overridden with 385 * new one drop it. 386 */ 387 next = next->next; 388 389 if (prev) 390 prev->next = next; 391 else 392 fq->q.fragments = next; 393 394 fq->q.meat -= free_it->len; 395 frag_kfree_skb(fq->q.net, free_it, NULL); 396 } 397 } 398 399 FRAG6_CB(skb)->offset = offset; 400 401 /* Insert this fragment in the chain of fragments. */ 402 skb->next = next; 403 if (prev) 404 prev->next = skb; 405 else 406 fq->q.fragments = skb; 407 408 dev = skb->dev; 409 if (dev) { 410 fq->iif = dev->ifindex; 411 skb->dev = NULL; 412 } 413 fq->q.stamp = skb->tstamp; 414 fq->q.meat += skb->len; 415 atomic_add(skb->truesize, &fq->q.net->mem); 416 417 /* The first fragment. 418 * nhoffset is obtained from the first fragment, of course. 419 */ 420 if (offset == 0) { 421 fq->nhoffset = nhoff; 422 fq->q.last_in |= INET_FRAG_FIRST_IN; 423 } 424 425 if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && 426 fq->q.meat == fq->q.len) 427 return ip6_frag_reasm(fq, prev, dev); 428 429 write_lock(&ip6_frags.lock); 430 list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list); 431 write_unlock(&ip6_frags.lock); 432 return -1; 433 434 err: 435 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS); 436 kfree_skb(skb); 437 return -1; 438 } 439 440 /* 441 * Check if this packet is complete. 442 * Returns NULL on failure by any reason, and pointer 443 * to current nexthdr field in reassembled frame. 444 * 445 * It is called with locked fq, and caller must check that 446 * queue is eligible for reassembly i.e. it is not COMPLETE, 447 * the last and the first frames arrived and all the bits are here. 448 */ 449 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, 450 struct net_device *dev) 451 { 452 struct sk_buff *fp, *head = fq->q.fragments; 453 int payload_len; 454 unsigned int nhoff; 455 456 fq_kill(fq); 457 458 /* Make the one we just received the head. */ 459 if (prev) { 460 head = prev->next; 461 fp = skb_clone(head, GFP_ATOMIC); 462 463 if (!fp) 464 goto out_oom; 465 466 fp->next = head->next; 467 prev->next = fp; 468 469 skb_morph(head, fq->q.fragments); 470 head->next = fq->q.fragments->next; 471 472 kfree_skb(fq->q.fragments); 473 fq->q.fragments = head; 474 } 475 476 WARN_ON(head == NULL); 477 WARN_ON(FRAG6_CB(head)->offset != 0); 478 479 /* Unfragmented part is taken from the first segment. */ 480 payload_len = ((head->data - skb_network_header(head)) - 481 sizeof(struct ipv6hdr) + fq->q.len - 482 sizeof(struct frag_hdr)); 483 if (payload_len > IPV6_MAXPLEN) 484 goto out_oversize; 485 486 /* Head of list must not be cloned. */ 487 if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) 488 goto out_oom; 489 490 /* If the first fragment is fragmented itself, we split 491 * it to two chunks: the first with data and paged part 492 * and the second, holding only fragments. */ 493 if (skb_shinfo(head)->frag_list) { 494 struct sk_buff *clone; 495 int i, plen = 0; 496 497 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) 498 goto out_oom; 499 clone->next = head->next; 500 head->next = clone; 501 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; 502 skb_shinfo(head)->frag_list = NULL; 503 for (i=0; i<skb_shinfo(head)->nr_frags; i++) 504 plen += skb_shinfo(head)->frags[i].size; 505 clone->len = clone->data_len = head->data_len - plen; 506 head->data_len -= clone->len; 507 head->len -= clone->len; 508 clone->csum = 0; 509 clone->ip_summed = head->ip_summed; 510 atomic_add(clone->truesize, &fq->q.net->mem); 511 } 512 513 /* We have to remove fragment header from datagram and to relocate 514 * header in order to calculate ICV correctly. */ 515 nhoff = fq->nhoffset; 516 skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; 517 memmove(head->head + sizeof(struct frag_hdr), head->head, 518 (head->data - head->head) - sizeof(struct frag_hdr)); 519 head->mac_header += sizeof(struct frag_hdr); 520 head->network_header += sizeof(struct frag_hdr); 521 522 skb_shinfo(head)->frag_list = head->next; 523 skb_reset_transport_header(head); 524 skb_push(head, head->data - skb_network_header(head)); 525 atomic_sub(head->truesize, &fq->q.net->mem); 526 527 for (fp=head->next; fp; fp = fp->next) { 528 head->data_len += fp->len; 529 head->len += fp->len; 530 if (head->ip_summed != fp->ip_summed) 531 head->ip_summed = CHECKSUM_NONE; 532 else if (head->ip_summed == CHECKSUM_COMPLETE) 533 head->csum = csum_add(head->csum, fp->csum); 534 head->truesize += fp->truesize; 535 atomic_sub(fp->truesize, &fq->q.net->mem); 536 } 537 538 head->next = NULL; 539 head->dev = dev; 540 head->tstamp = fq->q.stamp; 541 ipv6_hdr(head)->payload_len = htons(payload_len); 542 IP6CB(head)->nhoff = nhoff; 543 544 /* Yes, and fold redundant checksum back. 8) */ 545 if (head->ip_summed == CHECKSUM_COMPLETE) 546 head->csum = csum_partial(skb_network_header(head), 547 skb_network_header_len(head), 548 head->csum); 549 550 rcu_read_lock(); 551 IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMOKS); 552 rcu_read_unlock(); 553 fq->q.fragments = NULL; 554 return 1; 555 556 out_oversize: 557 if (net_ratelimit()) 558 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len); 559 goto out_fail; 560 out_oom: 561 if (net_ratelimit()) 562 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n"); 563 out_fail: 564 rcu_read_lock(); 565 IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 566 rcu_read_unlock(); 567 return -1; 568 } 569 570 static int ipv6_frag_rcv(struct sk_buff *skb) 571 { 572 struct frag_hdr *fhdr; 573 struct frag_queue *fq; 574 struct ipv6hdr *hdr = ipv6_hdr(skb); 575 struct net *net; 576 577 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMREQDS); 578 579 /* Jumbo payload inhibits frag. header */ 580 if (hdr->payload_len==0) { 581 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); 582 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 583 skb_network_header_len(skb)); 584 return -1; 585 } 586 if (!pskb_may_pull(skb, (skb_transport_offset(skb) + 587 sizeof(struct frag_hdr)))) { 588 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); 589 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, 590 skb_network_header_len(skb)); 591 return -1; 592 } 593 594 hdr = ipv6_hdr(skb); 595 fhdr = (struct frag_hdr *)skb_transport_header(skb); 596 597 if (!(fhdr->frag_off & htons(0xFFF9))) { 598 /* It is not a fragmented frame */ 599 skb->transport_header += sizeof(struct frag_hdr); 600 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMOKS); 601 602 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); 603 return 1; 604 } 605 606 net = dev_net(skb->dev); 607 if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh) 608 ip6_evictor(net, ip6_dst_idev(skb->dst)); 609 610 if ((fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, 611 ip6_dst_idev(skb->dst))) != NULL) { 612 int ret; 613 614 spin_lock(&fq->q.lock); 615 616 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); 617 618 spin_unlock(&fq->q.lock); 619 fq_put(fq); 620 return ret; 621 } 622 623 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS); 624 kfree_skb(skb); 625 return -1; 626 } 627 628 static struct inet6_protocol frag_protocol = 629 { 630 .handler = ipv6_frag_rcv, 631 .flags = INET6_PROTO_NOPOLICY, 632 }; 633 634 #ifdef CONFIG_SYSCTL 635 static struct ctl_table ip6_frags_ns_ctl_table[] = { 636 { 637 .ctl_name = NET_IPV6_IP6FRAG_HIGH_THRESH, 638 .procname = "ip6frag_high_thresh", 639 .data = &init_net.ipv6.frags.high_thresh, 640 .maxlen = sizeof(int), 641 .mode = 0644, 642 .proc_handler = &proc_dointvec 643 }, 644 { 645 .ctl_name = NET_IPV6_IP6FRAG_LOW_THRESH, 646 .procname = "ip6frag_low_thresh", 647 .data = &init_net.ipv6.frags.low_thresh, 648 .maxlen = sizeof(int), 649 .mode = 0644, 650 .proc_handler = &proc_dointvec 651 }, 652 { 653 .ctl_name = NET_IPV6_IP6FRAG_TIME, 654 .procname = "ip6frag_time", 655 .data = &init_net.ipv6.frags.timeout, 656 .maxlen = sizeof(int), 657 .mode = 0644, 658 .proc_handler = &proc_dointvec_jiffies, 659 .strategy = &sysctl_jiffies, 660 }, 661 { } 662 }; 663 664 static struct ctl_table ip6_frags_ctl_table[] = { 665 { 666 .ctl_name = NET_IPV6_IP6FRAG_SECRET_INTERVAL, 667 .procname = "ip6frag_secret_interval", 668 .data = &ip6_frags.secret_interval, 669 .maxlen = sizeof(int), 670 .mode = 0644, 671 .proc_handler = &proc_dointvec_jiffies, 672 .strategy = &sysctl_jiffies 673 }, 674 { } 675 }; 676 677 static int ip6_frags_ns_sysctl_register(struct net *net) 678 { 679 struct ctl_table *table; 680 struct ctl_table_header *hdr; 681 682 table = ip6_frags_ns_ctl_table; 683 if (net != &init_net) { 684 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); 685 if (table == NULL) 686 goto err_alloc; 687 688 table[0].data = &net->ipv6.frags.high_thresh; 689 table[1].data = &net->ipv6.frags.low_thresh; 690 table[2].data = &net->ipv6.frags.timeout; 691 } 692 693 hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table); 694 if (hdr == NULL) 695 goto err_reg; 696 697 net->ipv6.sysctl.frags_hdr = hdr; 698 return 0; 699 700 err_reg: 701 if (net != &init_net) 702 kfree(table); 703 err_alloc: 704 return -ENOMEM; 705 } 706 707 static void ip6_frags_ns_sysctl_unregister(struct net *net) 708 { 709 struct ctl_table *table; 710 711 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; 712 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); 713 kfree(table); 714 } 715 716 static struct ctl_table_header *ip6_ctl_header; 717 718 static int ip6_frags_sysctl_register(void) 719 { 720 ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path, 721 ip6_frags_ctl_table); 722 return ip6_ctl_header == NULL ? -ENOMEM : 0; 723 } 724 725 static void ip6_frags_sysctl_unregister(void) 726 { 727 unregister_net_sysctl_table(ip6_ctl_header); 728 } 729 #else 730 static inline int ip6_frags_ns_sysctl_register(struct net *net) 731 { 732 return 0; 733 } 734 735 static inline void ip6_frags_ns_sysctl_unregister(struct net *net) 736 { 737 } 738 739 static inline int ip6_frags_sysctl_register(void) 740 { 741 return 0; 742 } 743 744 static inline void ip6_frags_sysctl_unregister(void) 745 { 746 } 747 #endif 748 749 static int ipv6_frags_init_net(struct net *net) 750 { 751 net->ipv6.frags.high_thresh = 256 * 1024; 752 net->ipv6.frags.low_thresh = 192 * 1024; 753 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; 754 755 inet_frags_init_net(&net->ipv6.frags); 756 757 return ip6_frags_ns_sysctl_register(net); 758 } 759 760 static void ipv6_frags_exit_net(struct net *net) 761 { 762 ip6_frags_ns_sysctl_unregister(net); 763 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); 764 } 765 766 static struct pernet_operations ip6_frags_ops = { 767 .init = ipv6_frags_init_net, 768 .exit = ipv6_frags_exit_net, 769 }; 770 771 int __init ipv6_frag_init(void) 772 { 773 int ret; 774 775 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); 776 if (ret) 777 goto out; 778 779 ret = ip6_frags_sysctl_register(); 780 if (ret) 781 goto err_sysctl; 782 783 ret = register_pernet_subsys(&ip6_frags_ops); 784 if (ret) 785 goto err_pernet; 786 787 ip6_frags.hashfn = ip6_hashfn; 788 ip6_frags.constructor = ip6_frag_init; 789 ip6_frags.destructor = NULL; 790 ip6_frags.skb_free = NULL; 791 ip6_frags.qsize = sizeof(struct frag_queue); 792 ip6_frags.match = ip6_frag_match; 793 ip6_frags.frag_expire = ip6_frag_expire; 794 ip6_frags.secret_interval = 10 * 60 * HZ; 795 inet_frags_init(&ip6_frags); 796 out: 797 return ret; 798 799 err_pernet: 800 ip6_frags_sysctl_unregister(); 801 err_sysctl: 802 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 803 goto out; 804 } 805 806 void ipv6_frag_exit(void) 807 { 808 inet_frags_fini(&ip6_frags); 809 ip6_frags_sysctl_unregister(); 810 unregister_pernet_subsys(&ip6_frags_ops); 811 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); 812 } 813