1 /* 2 * Internet Control Message Protocol (ICMPv6) 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * Based on net/ipv4/icmp.c 9 * 10 * RFC 1885 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 */ 17 18 /* 19 * Changes: 20 * 21 * Andi Kleen : exception handling 22 * Andi Kleen add rate limits. never reply to a icmp. 23 * add more length checks and other fixes. 24 * yoshfuji : ensure to sent parameter problem for 25 * fragments. 26 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit. 27 * Randy Dunlap and 28 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support 29 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data 30 */ 31 32 #include <linux/module.h> 33 #include <linux/errno.h> 34 #include <linux/types.h> 35 #include <linux/socket.h> 36 #include <linux/in.h> 37 #include <linux/kernel.h> 38 #include <linux/sockios.h> 39 #include <linux/net.h> 40 #include <linux/skbuff.h> 41 #include <linux/init.h> 42 #include <linux/netfilter.h> 43 #include <linux/slab.h> 44 45 #ifdef CONFIG_SYSCTL 46 #include <linux/sysctl.h> 47 #endif 48 49 #include <linux/inet.h> 50 #include <linux/netdevice.h> 51 #include <linux/icmpv6.h> 52 53 #include <net/ip.h> 54 #include <net/sock.h> 55 56 #include <net/ipv6.h> 57 #include <net/ip6_checksum.h> 58 #include <net/protocol.h> 59 #include <net/raw.h> 60 #include <net/rawv6.h> 61 #include <net/transp_v6.h> 62 #include <net/ip6_route.h> 63 #include <net/addrconf.h> 64 #include <net/icmp.h> 65 #include <net/xfrm.h> 66 #include <net/inet_common.h> 67 68 #include <asm/uaccess.h> 69 #include <asm/system.h> 70 71 /* 72 * The ICMP socket(s). This is the most convenient way to flow control 73 * our ICMP output as well as maintain a clean interface throughout 74 * all layers. All Socketless IP sends will soon be gone. 75 * 76 * On SMP we have one ICMP socket per-cpu. 77 */ 78 static inline struct sock *icmpv6_sk(struct net *net) 79 { 80 return net->ipv6.icmp_sk[smp_processor_id()]; 81 } 82 83 static int icmpv6_rcv(struct sk_buff *skb); 84 85 static const struct inet6_protocol icmpv6_protocol = { 86 .handler = icmpv6_rcv, 87 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 88 }; 89 90 static __inline__ struct sock *icmpv6_xmit_lock(struct net *net) 91 { 92 struct sock *sk; 93 94 local_bh_disable(); 95 96 sk = icmpv6_sk(net); 97 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { 98 /* This can happen if the output path (f.e. SIT or 99 * ip6ip6 tunnel) signals dst_link_failure() for an 100 * outgoing ICMP6 packet. 101 */ 102 local_bh_enable(); 103 return NULL; 104 } 105 return sk; 106 } 107 108 static __inline__ void icmpv6_xmit_unlock(struct sock *sk) 109 { 110 spin_unlock_bh(&sk->sk_lock.slock); 111 } 112 113 /* 114 * Slightly more convenient version of icmpv6_send. 115 */ 116 void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) 117 { 118 icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos); 119 kfree_skb(skb); 120 } 121 122 /* 123 * Figure out, may we reply to this packet with icmp error. 124 * 125 * We do not reply, if: 126 * - it was icmp error message. 127 * - it is truncated, so that it is known, that protocol is ICMPV6 128 * (i.e. in the middle of some exthdr) 129 * 130 * --ANK (980726) 131 */ 132 133 static int is_ineligible(struct sk_buff *skb) 134 { 135 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; 136 int len = skb->len - ptr; 137 __u8 nexthdr = ipv6_hdr(skb)->nexthdr; 138 139 if (len < 0) 140 return 1; 141 142 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr); 143 if (ptr < 0) 144 return 0; 145 if (nexthdr == IPPROTO_ICMPV6) { 146 u8 _type, *tp; 147 tp = skb_header_pointer(skb, 148 ptr+offsetof(struct icmp6hdr, icmp6_type), 149 sizeof(_type), &_type); 150 if (tp == NULL || 151 !(*tp & ICMPV6_INFOMSG_MASK)) 152 return 1; 153 } 154 return 0; 155 } 156 157 /* 158 * Check the ICMP output rate limit 159 */ 160 static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type, 161 struct flowi6 *fl6) 162 { 163 struct dst_entry *dst; 164 struct net *net = sock_net(sk); 165 bool res = false; 166 167 /* Informational messages are not limited. */ 168 if (type & ICMPV6_INFOMSG_MASK) 169 return true; 170 171 /* Do not limit pmtu discovery, it would break it. */ 172 if (type == ICMPV6_PKT_TOOBIG) 173 return true; 174 175 /* 176 * Look up the output route. 177 * XXX: perhaps the expire for routing entries cloned by 178 * this lookup should be more aggressive (not longer than timeout). 179 */ 180 dst = ip6_route_output(net, sk, fl6); 181 if (dst->error) { 182 IP6_INC_STATS(net, ip6_dst_idev(dst), 183 IPSTATS_MIB_OUTNOROUTES); 184 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { 185 res = true; 186 } else { 187 struct rt6_info *rt = (struct rt6_info *)dst; 188 int tmo = net->ipv6.sysctl.icmpv6_time; 189 190 /* Give more bandwidth to wider prefixes. */ 191 if (rt->rt6i_dst.plen < 128) 192 tmo >>= ((128 - rt->rt6i_dst.plen)>>5); 193 194 if (!rt->rt6i_peer) 195 rt6_bind_peer(rt, 1); 196 res = inet_peer_xrlim_allow(rt->rt6i_peer, tmo); 197 } 198 dst_release(dst); 199 return res; 200 } 201 202 /* 203 * an inline helper for the "simple" if statement below 204 * checks if parameter problem report is caused by an 205 * unrecognized IPv6 option that has the Option Type 206 * highest-order two bits set to 10 207 */ 208 209 static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset) 210 { 211 u8 _optval, *op; 212 213 offset += skb_network_offset(skb); 214 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); 215 if (op == NULL) 216 return 1; 217 return (*op & 0xC0) == 0x80; 218 } 219 220 static int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, struct icmp6hdr *thdr, int len) 221 { 222 struct sk_buff *skb; 223 struct icmp6hdr *icmp6h; 224 int err = 0; 225 226 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) 227 goto out; 228 229 icmp6h = icmp6_hdr(skb); 230 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); 231 icmp6h->icmp6_cksum = 0; 232 233 if (skb_queue_len(&sk->sk_write_queue) == 1) { 234 skb->csum = csum_partial(icmp6h, 235 sizeof(struct icmp6hdr), skb->csum); 236 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, 237 &fl6->daddr, 238 len, fl6->flowi6_proto, 239 skb->csum); 240 } else { 241 __wsum tmp_csum = 0; 242 243 skb_queue_walk(&sk->sk_write_queue, skb) { 244 tmp_csum = csum_add(tmp_csum, skb->csum); 245 } 246 247 tmp_csum = csum_partial(icmp6h, 248 sizeof(struct icmp6hdr), tmp_csum); 249 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, 250 &fl6->daddr, 251 len, fl6->flowi6_proto, 252 tmp_csum); 253 } 254 ip6_push_pending_frames(sk); 255 out: 256 return err; 257 } 258 259 struct icmpv6_msg { 260 struct sk_buff *skb; 261 int offset; 262 uint8_t type; 263 }; 264 265 static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) 266 { 267 struct icmpv6_msg *msg = (struct icmpv6_msg *) from; 268 struct sk_buff *org_skb = msg->skb; 269 __wsum csum = 0; 270 271 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, 272 to, len, csum); 273 skb->csum = csum_block_add(skb->csum, csum, odd); 274 if (!(msg->type & ICMPV6_INFOMSG_MASK)) 275 nf_ct_attach(skb, org_skb); 276 return 0; 277 } 278 279 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 280 static void mip6_addr_swap(struct sk_buff *skb) 281 { 282 struct ipv6hdr *iph = ipv6_hdr(skb); 283 struct inet6_skb_parm *opt = IP6CB(skb); 284 struct ipv6_destopt_hao *hao; 285 struct in6_addr tmp; 286 int off; 287 288 if (opt->dsthao) { 289 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); 290 if (likely(off >= 0)) { 291 hao = (struct ipv6_destopt_hao *) 292 (skb_network_header(skb) + off); 293 ipv6_addr_copy(&tmp, &iph->saddr); 294 ipv6_addr_copy(&iph->saddr, &hao->addr); 295 ipv6_addr_copy(&hao->addr, &tmp); 296 } 297 } 298 } 299 #else 300 static inline void mip6_addr_swap(struct sk_buff *skb) {} 301 #endif 302 303 static struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb, 304 struct sock *sk, struct flowi6 *fl6) 305 { 306 struct dst_entry *dst, *dst2; 307 struct flowi6 fl2; 308 int err; 309 310 err = ip6_dst_lookup(sk, &dst, fl6); 311 if (err) 312 return ERR_PTR(err); 313 314 /* 315 * We won't send icmp if the destination is known 316 * anycast. 317 */ 318 if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { 319 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n"); 320 dst_release(dst); 321 return ERR_PTR(-EINVAL); 322 } 323 324 /* No need to clone since we're just using its address. */ 325 dst2 = dst; 326 327 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0); 328 if (!IS_ERR(dst)) { 329 if (dst != dst2) 330 return dst; 331 } else { 332 if (PTR_ERR(dst) == -EPERM) 333 dst = NULL; 334 else 335 return dst; 336 } 337 338 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6); 339 if (err) 340 goto relookup_failed; 341 342 err = ip6_dst_lookup(sk, &dst2, &fl2); 343 if (err) 344 goto relookup_failed; 345 346 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP); 347 if (!IS_ERR(dst2)) { 348 dst_release(dst); 349 dst = dst2; 350 } else { 351 err = PTR_ERR(dst2); 352 if (err == -EPERM) { 353 dst_release(dst); 354 return dst2; 355 } else 356 goto relookup_failed; 357 } 358 359 relookup_failed: 360 if (dst) 361 return dst; 362 return ERR_PTR(err); 363 } 364 365 /* 366 * Send an ICMP message in response to a packet in error 367 */ 368 void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) 369 { 370 struct net *net = dev_net(skb->dev); 371 struct inet6_dev *idev = NULL; 372 struct ipv6hdr *hdr = ipv6_hdr(skb); 373 struct sock *sk; 374 struct ipv6_pinfo *np; 375 struct in6_addr *saddr = NULL; 376 struct dst_entry *dst; 377 struct icmp6hdr tmp_hdr; 378 struct flowi6 fl6; 379 struct icmpv6_msg msg; 380 int iif = 0; 381 int addr_type = 0; 382 int len; 383 int hlimit; 384 int err = 0; 385 386 if ((u8 *)hdr < skb->head || 387 (skb->network_header + sizeof(*hdr)) > skb->tail) 388 return; 389 390 /* 391 * Make sure we respect the rules 392 * i.e. RFC 1885 2.4(e) 393 * Rule (e.1) is enforced by not using icmpv6_send 394 * in any code that processes icmp errors. 395 */ 396 addr_type = ipv6_addr_type(&hdr->daddr); 397 398 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0)) 399 saddr = &hdr->daddr; 400 401 /* 402 * Dest addr check 403 */ 404 405 if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { 406 if (type != ICMPV6_PKT_TOOBIG && 407 !(type == ICMPV6_PARAMPROB && 408 code == ICMPV6_UNK_OPTION && 409 (opt_unrec(skb, info)))) 410 return; 411 412 saddr = NULL; 413 } 414 415 addr_type = ipv6_addr_type(&hdr->saddr); 416 417 /* 418 * Source addr check 419 */ 420 421 if (addr_type & IPV6_ADDR_LINKLOCAL) 422 iif = skb->dev->ifindex; 423 424 /* 425 * Must not send error if the source does not uniquely 426 * identify a single node (RFC2463 Section 2.4). 427 * We check unspecified / multicast addresses here, 428 * and anycast addresses will be checked later. 429 */ 430 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { 431 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n"); 432 return; 433 } 434 435 /* 436 * Never answer to a ICMP packet. 437 */ 438 if (is_ineligible(skb)) { 439 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n"); 440 return; 441 } 442 443 mip6_addr_swap(skb); 444 445 memset(&fl6, 0, sizeof(fl6)); 446 fl6.flowi6_proto = IPPROTO_ICMPV6; 447 ipv6_addr_copy(&fl6.daddr, &hdr->saddr); 448 if (saddr) 449 ipv6_addr_copy(&fl6.saddr, saddr); 450 fl6.flowi6_oif = iif; 451 fl6.uli.icmpt.type = type; 452 fl6.uli.icmpt.code = code; 453 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); 454 455 sk = icmpv6_xmit_lock(net); 456 if (sk == NULL) 457 return; 458 np = inet6_sk(sk); 459 460 if (!icmpv6_xrlim_allow(sk, type, &fl6)) 461 goto out; 462 463 tmp_hdr.icmp6_type = type; 464 tmp_hdr.icmp6_code = code; 465 tmp_hdr.icmp6_cksum = 0; 466 tmp_hdr.icmp6_pointer = htonl(info); 467 468 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 469 fl6.flowi6_oif = np->mcast_oif; 470 471 dst = icmpv6_route_lookup(net, skb, sk, &fl6); 472 if (IS_ERR(dst)) 473 goto out; 474 475 if (ipv6_addr_is_multicast(&fl6.daddr)) 476 hlimit = np->mcast_hops; 477 else 478 hlimit = np->hop_limit; 479 if (hlimit < 0) 480 hlimit = ip6_dst_hoplimit(dst); 481 482 msg.skb = skb; 483 msg.offset = skb_network_offset(skb); 484 msg.type = type; 485 486 len = skb->len - msg.offset; 487 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); 488 if (len < 0) { 489 LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); 490 goto out_dst_release; 491 } 492 493 idev = in6_dev_get(skb->dev); 494 495 err = ip6_append_data(sk, icmpv6_getfrag, &msg, 496 len + sizeof(struct icmp6hdr), 497 sizeof(struct icmp6hdr), hlimit, 498 np->tclass, NULL, &fl6, (struct rt6_info*)dst, 499 MSG_DONTWAIT, np->dontfrag); 500 if (err) { 501 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); 502 ip6_flush_pending_frames(sk); 503 goto out_put; 504 } 505 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, len + sizeof(struct icmp6hdr)); 506 507 out_put: 508 if (likely(idev != NULL)) 509 in6_dev_put(idev); 510 out_dst_release: 511 dst_release(dst); 512 out: 513 icmpv6_xmit_unlock(sk); 514 } 515 516 EXPORT_SYMBOL(icmpv6_send); 517 518 static void icmpv6_echo_reply(struct sk_buff *skb) 519 { 520 struct net *net = dev_net(skb->dev); 521 struct sock *sk; 522 struct inet6_dev *idev; 523 struct ipv6_pinfo *np; 524 struct in6_addr *saddr = NULL; 525 struct icmp6hdr *icmph = icmp6_hdr(skb); 526 struct icmp6hdr tmp_hdr; 527 struct flowi6 fl6; 528 struct icmpv6_msg msg; 529 struct dst_entry *dst; 530 int err = 0; 531 int hlimit; 532 533 saddr = &ipv6_hdr(skb)->daddr; 534 535 if (!ipv6_unicast_destination(skb)) 536 saddr = NULL; 537 538 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); 539 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; 540 541 memset(&fl6, 0, sizeof(fl6)); 542 fl6.flowi6_proto = IPPROTO_ICMPV6; 543 ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->saddr); 544 if (saddr) 545 ipv6_addr_copy(&fl6.saddr, saddr); 546 fl6.flowi6_oif = skb->dev->ifindex; 547 fl6.uli.icmpt.type = ICMPV6_ECHO_REPLY; 548 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); 549 550 sk = icmpv6_xmit_lock(net); 551 if (sk == NULL) 552 return; 553 np = inet6_sk(sk); 554 555 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 556 fl6.flowi6_oif = np->mcast_oif; 557 558 err = ip6_dst_lookup(sk, &dst, &fl6); 559 if (err) 560 goto out; 561 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); 562 if (IS_ERR(dst)) 563 goto out; 564 565 if (ipv6_addr_is_multicast(&fl6.daddr)) 566 hlimit = np->mcast_hops; 567 else 568 hlimit = np->hop_limit; 569 if (hlimit < 0) 570 hlimit = ip6_dst_hoplimit(dst); 571 572 idev = in6_dev_get(skb->dev); 573 574 msg.skb = skb; 575 msg.offset = 0; 576 msg.type = ICMPV6_ECHO_REPLY; 577 578 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), 579 sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl6, 580 (struct rt6_info*)dst, MSG_DONTWAIT, 581 np->dontfrag); 582 583 if (err) { 584 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); 585 ip6_flush_pending_frames(sk); 586 goto out_put; 587 } 588 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, skb->len + sizeof(struct icmp6hdr)); 589 590 out_put: 591 if (likely(idev != NULL)) 592 in6_dev_put(idev); 593 dst_release(dst); 594 out: 595 icmpv6_xmit_unlock(sk); 596 } 597 598 static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) 599 { 600 const struct inet6_protocol *ipprot; 601 int inner_offset; 602 int hash; 603 u8 nexthdr; 604 605 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 606 return; 607 608 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; 609 if (ipv6_ext_hdr(nexthdr)) { 610 /* now skip over extension headers */ 611 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); 612 if (inner_offset<0) 613 return; 614 } else { 615 inner_offset = sizeof(struct ipv6hdr); 616 } 617 618 /* Checkin header including 8 bytes of inner protocol header. */ 619 if (!pskb_may_pull(skb, inner_offset+8)) 620 return; 621 622 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. 623 Without this we will not able f.e. to make source routed 624 pmtu discovery. 625 Corresponding argument (opt) to notifiers is already added. 626 --ANK (980726) 627 */ 628 629 hash = nexthdr & (MAX_INET_PROTOS - 1); 630 631 rcu_read_lock(); 632 ipprot = rcu_dereference(inet6_protos[hash]); 633 if (ipprot && ipprot->err_handler) 634 ipprot->err_handler(skb, NULL, type, code, inner_offset, info); 635 rcu_read_unlock(); 636 637 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); 638 } 639 640 /* 641 * Handle icmp messages 642 */ 643 644 static int icmpv6_rcv(struct sk_buff *skb) 645 { 646 struct net_device *dev = skb->dev; 647 struct inet6_dev *idev = __in6_dev_get(dev); 648 struct in6_addr *saddr, *daddr; 649 struct ipv6hdr *orig_hdr; 650 struct icmp6hdr *hdr; 651 u8 type; 652 653 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 654 struct sec_path *sp = skb_sec_path(skb); 655 int nh; 656 657 if (!(sp && sp->xvec[sp->len - 1]->props.flags & 658 XFRM_STATE_ICMP)) 659 goto drop_no_count; 660 661 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr))) 662 goto drop_no_count; 663 664 nh = skb_network_offset(skb); 665 skb_set_network_header(skb, sizeof(*hdr)); 666 667 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) 668 goto drop_no_count; 669 670 skb_set_network_header(skb, nh); 671 } 672 673 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS); 674 675 saddr = &ipv6_hdr(skb)->saddr; 676 daddr = &ipv6_hdr(skb)->daddr; 677 678 /* Perform checksum. */ 679 switch (skb->ip_summed) { 680 case CHECKSUM_COMPLETE: 681 if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, 682 skb->csum)) 683 break; 684 /* fall through */ 685 case CHECKSUM_NONE: 686 skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len, 687 IPPROTO_ICMPV6, 0)); 688 if (__skb_checksum_complete(skb)) { 689 LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%pI6 > %pI6]\n", 690 saddr, daddr); 691 goto discard_it; 692 } 693 } 694 695 if (!pskb_pull(skb, sizeof(*hdr))) 696 goto discard_it; 697 698 hdr = icmp6_hdr(skb); 699 700 type = hdr->icmp6_type; 701 702 ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type); 703 704 switch (type) { 705 case ICMPV6_ECHO_REQUEST: 706 icmpv6_echo_reply(skb); 707 break; 708 709 case ICMPV6_ECHO_REPLY: 710 /* we couldn't care less */ 711 break; 712 713 case ICMPV6_PKT_TOOBIG: 714 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update 715 standard destination cache. Seems, only "advanced" 716 destination cache will allow to solve this problem 717 --ANK (980726) 718 */ 719 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 720 goto discard_it; 721 hdr = icmp6_hdr(skb); 722 orig_hdr = (struct ipv6hdr *) (hdr + 1); 723 rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, 724 ntohl(hdr->icmp6_mtu)); 725 726 /* 727 * Drop through to notify 728 */ 729 730 case ICMPV6_DEST_UNREACH: 731 case ICMPV6_TIME_EXCEED: 732 case ICMPV6_PARAMPROB: 733 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); 734 break; 735 736 case NDISC_ROUTER_SOLICITATION: 737 case NDISC_ROUTER_ADVERTISEMENT: 738 case NDISC_NEIGHBOUR_SOLICITATION: 739 case NDISC_NEIGHBOUR_ADVERTISEMENT: 740 case NDISC_REDIRECT: 741 ndisc_rcv(skb); 742 break; 743 744 case ICMPV6_MGM_QUERY: 745 igmp6_event_query(skb); 746 break; 747 748 case ICMPV6_MGM_REPORT: 749 igmp6_event_report(skb); 750 break; 751 752 case ICMPV6_MGM_REDUCTION: 753 case ICMPV6_NI_QUERY: 754 case ICMPV6_NI_REPLY: 755 case ICMPV6_MLD2_REPORT: 756 case ICMPV6_DHAAD_REQUEST: 757 case ICMPV6_DHAAD_REPLY: 758 case ICMPV6_MOBILE_PREFIX_SOL: 759 case ICMPV6_MOBILE_PREFIX_ADV: 760 break; 761 762 default: 763 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); 764 765 /* informational */ 766 if (type & ICMPV6_INFOMSG_MASK) 767 break; 768 769 /* 770 * error of unknown type. 771 * must pass to upper level 772 */ 773 774 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); 775 } 776 777 kfree_skb(skb); 778 return 0; 779 780 discard_it: 781 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS); 782 drop_no_count: 783 kfree_skb(skb); 784 return 0; 785 } 786 787 void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6, 788 u8 type, 789 const struct in6_addr *saddr, 790 const struct in6_addr *daddr, 791 int oif) 792 { 793 memset(fl6, 0, sizeof(*fl6)); 794 ipv6_addr_copy(&fl6->saddr, saddr); 795 ipv6_addr_copy(&fl6->daddr, daddr); 796 fl6->flowi6_proto = IPPROTO_ICMPV6; 797 fl6->uli.icmpt.type = type; 798 fl6->uli.icmpt.code = 0; 799 fl6->flowi6_oif = oif; 800 security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); 801 } 802 803 /* 804 * Special lock-class for __icmpv6_sk: 805 */ 806 static struct lock_class_key icmpv6_socket_sk_dst_lock_key; 807 808 static int __net_init icmpv6_sk_init(struct net *net) 809 { 810 struct sock *sk; 811 int err, i, j; 812 813 net->ipv6.icmp_sk = 814 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); 815 if (net->ipv6.icmp_sk == NULL) 816 return -ENOMEM; 817 818 for_each_possible_cpu(i) { 819 err = inet_ctl_sock_create(&sk, PF_INET6, 820 SOCK_RAW, IPPROTO_ICMPV6, net); 821 if (err < 0) { 822 printk(KERN_ERR 823 "Failed to initialize the ICMP6 control socket " 824 "(err %d).\n", 825 err); 826 goto fail; 827 } 828 829 net->ipv6.icmp_sk[i] = sk; 830 831 /* 832 * Split off their lock-class, because sk->sk_dst_lock 833 * gets used from softirqs, which is safe for 834 * __icmpv6_sk (because those never get directly used 835 * via userspace syscalls), but unsafe for normal sockets. 836 */ 837 lockdep_set_class(&sk->sk_dst_lock, 838 &icmpv6_socket_sk_dst_lock_key); 839 840 /* Enough space for 2 64K ICMP packets, including 841 * sk_buff struct overhead. 842 */ 843 sk->sk_sndbuf = 844 (2 * ((64 * 1024) + sizeof(struct sk_buff))); 845 } 846 return 0; 847 848 fail: 849 for (j = 0; j < i; j++) 850 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]); 851 kfree(net->ipv6.icmp_sk); 852 return err; 853 } 854 855 static void __net_exit icmpv6_sk_exit(struct net *net) 856 { 857 int i; 858 859 for_each_possible_cpu(i) { 860 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]); 861 } 862 kfree(net->ipv6.icmp_sk); 863 } 864 865 static struct pernet_operations icmpv6_sk_ops = { 866 .init = icmpv6_sk_init, 867 .exit = icmpv6_sk_exit, 868 }; 869 870 int __init icmpv6_init(void) 871 { 872 int err; 873 874 err = register_pernet_subsys(&icmpv6_sk_ops); 875 if (err < 0) 876 return err; 877 878 err = -EAGAIN; 879 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) 880 goto fail; 881 return 0; 882 883 fail: 884 printk(KERN_ERR "Failed to register ICMP6 protocol\n"); 885 unregister_pernet_subsys(&icmpv6_sk_ops); 886 return err; 887 } 888 889 void icmpv6_cleanup(void) 890 { 891 unregister_pernet_subsys(&icmpv6_sk_ops); 892 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); 893 } 894 895 896 static const struct icmp6_err { 897 int err; 898 int fatal; 899 } tab_unreach[] = { 900 { /* NOROUTE */ 901 .err = ENETUNREACH, 902 .fatal = 0, 903 }, 904 { /* ADM_PROHIBITED */ 905 .err = EACCES, 906 .fatal = 1, 907 }, 908 { /* Was NOT_NEIGHBOUR, now reserved */ 909 .err = EHOSTUNREACH, 910 .fatal = 0, 911 }, 912 { /* ADDR_UNREACH */ 913 .err = EHOSTUNREACH, 914 .fatal = 0, 915 }, 916 { /* PORT_UNREACH */ 917 .err = ECONNREFUSED, 918 .fatal = 1, 919 }, 920 }; 921 922 int icmpv6_err_convert(u8 type, u8 code, int *err) 923 { 924 int fatal = 0; 925 926 *err = EPROTO; 927 928 switch (type) { 929 case ICMPV6_DEST_UNREACH: 930 fatal = 1; 931 if (code <= ICMPV6_PORT_UNREACH) { 932 *err = tab_unreach[code].err; 933 fatal = tab_unreach[code].fatal; 934 } 935 break; 936 937 case ICMPV6_PKT_TOOBIG: 938 *err = EMSGSIZE; 939 break; 940 941 case ICMPV6_PARAMPROB: 942 *err = EPROTO; 943 fatal = 1; 944 break; 945 946 case ICMPV6_TIME_EXCEED: 947 *err = EHOSTUNREACH; 948 break; 949 } 950 951 return fatal; 952 } 953 954 EXPORT_SYMBOL(icmpv6_err_convert); 955 956 #ifdef CONFIG_SYSCTL 957 ctl_table ipv6_icmp_table_template[] = { 958 { 959 .procname = "ratelimit", 960 .data = &init_net.ipv6.sysctl.icmpv6_time, 961 .maxlen = sizeof(int), 962 .mode = 0644, 963 .proc_handler = proc_dointvec_ms_jiffies, 964 }, 965 { }, 966 }; 967 968 struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) 969 { 970 struct ctl_table *table; 971 972 table = kmemdup(ipv6_icmp_table_template, 973 sizeof(ipv6_icmp_table_template), 974 GFP_KERNEL); 975 976 if (table) 977 table[0].data = &net->ipv6.sysctl.icmpv6_time; 978 979 return table; 980 } 981 #endif 982 983