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 #define pr_fmt(fmt) "IPv6: " fmt 33 34 #include <linux/module.h> 35 #include <linux/errno.h> 36 #include <linux/types.h> 37 #include <linux/socket.h> 38 #include <linux/in.h> 39 #include <linux/kernel.h> 40 #include <linux/sockios.h> 41 #include <linux/net.h> 42 #include <linux/skbuff.h> 43 #include <linux/init.h> 44 #include <linux/netfilter.h> 45 #include <linux/slab.h> 46 47 #ifdef CONFIG_SYSCTL 48 #include <linux/sysctl.h> 49 #endif 50 51 #include <linux/inet.h> 52 #include <linux/netdevice.h> 53 #include <linux/icmpv6.h> 54 55 #include <net/ip.h> 56 #include <net/sock.h> 57 58 #include <net/ipv6.h> 59 #include <net/ip6_checksum.h> 60 #include <net/ping.h> 61 #include <net/protocol.h> 62 #include <net/raw.h> 63 #include <net/rawv6.h> 64 #include <net/transp_v6.h> 65 #include <net/ip6_route.h> 66 #include <net/addrconf.h> 67 #include <net/icmp.h> 68 #include <net/xfrm.h> 69 #include <net/inet_common.h> 70 #include <net/dsfield.h> 71 72 #include <asm/uaccess.h> 73 74 /* 75 * The ICMP socket(s). This is the most convenient way to flow control 76 * our ICMP output as well as maintain a clean interface throughout 77 * all layers. All Socketless IP sends will soon be gone. 78 * 79 * On SMP we have one ICMP socket per-cpu. 80 */ 81 static inline struct sock *icmpv6_sk(struct net *net) 82 { 83 return net->ipv6.icmp_sk[smp_processor_id()]; 84 } 85 86 static void icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 87 u8 type, u8 code, int offset, __be32 info) 88 { 89 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */ 90 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset); 91 struct net *net = dev_net(skb->dev); 92 93 if (type == ICMPV6_PKT_TOOBIG) 94 ip6_update_pmtu(skb, net, info, 0, 0); 95 else if (type == NDISC_REDIRECT) 96 ip6_redirect(skb, net, skb->dev->ifindex, 0); 97 98 if (!(type & ICMPV6_INFOMSG_MASK)) 99 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST) 100 ping_err(skb, offset, info); 101 } 102 103 static int icmpv6_rcv(struct sk_buff *skb); 104 105 static const struct inet6_protocol icmpv6_protocol = { 106 .handler = icmpv6_rcv, 107 .err_handler = icmpv6_err, 108 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 109 }; 110 111 static __inline__ struct sock *icmpv6_xmit_lock(struct net *net) 112 { 113 struct sock *sk; 114 115 local_bh_disable(); 116 117 sk = icmpv6_sk(net); 118 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { 119 /* This can happen if the output path (f.e. SIT or 120 * ip6ip6 tunnel) signals dst_link_failure() for an 121 * outgoing ICMP6 packet. 122 */ 123 local_bh_enable(); 124 return NULL; 125 } 126 return sk; 127 } 128 129 static __inline__ void icmpv6_xmit_unlock(struct sock *sk) 130 { 131 spin_unlock_bh(&sk->sk_lock.slock); 132 } 133 134 /* 135 * Figure out, may we reply to this packet with icmp error. 136 * 137 * We do not reply, if: 138 * - it was icmp error message. 139 * - it is truncated, so that it is known, that protocol is ICMPV6 140 * (i.e. in the middle of some exthdr) 141 * 142 * --ANK (980726) 143 */ 144 145 static bool is_ineligible(const struct sk_buff *skb) 146 { 147 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; 148 int len = skb->len - ptr; 149 __u8 nexthdr = ipv6_hdr(skb)->nexthdr; 150 __be16 frag_off; 151 152 if (len < 0) 153 return true; 154 155 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off); 156 if (ptr < 0) 157 return false; 158 if (nexthdr == IPPROTO_ICMPV6) { 159 u8 _type, *tp; 160 tp = skb_header_pointer(skb, 161 ptr+offsetof(struct icmp6hdr, icmp6_type), 162 sizeof(_type), &_type); 163 if (tp == NULL || 164 !(*tp & ICMPV6_INFOMSG_MASK)) 165 return true; 166 } 167 return false; 168 } 169 170 /* 171 * Check the ICMP output rate limit 172 */ 173 static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type, 174 struct flowi6 *fl6) 175 { 176 struct dst_entry *dst; 177 struct net *net = sock_net(sk); 178 bool res = false; 179 180 /* Informational messages are not limited. */ 181 if (type & ICMPV6_INFOMSG_MASK) 182 return true; 183 184 /* Do not limit pmtu discovery, it would break it. */ 185 if (type == ICMPV6_PKT_TOOBIG) 186 return true; 187 188 /* 189 * Look up the output route. 190 * XXX: perhaps the expire for routing entries cloned by 191 * this lookup should be more aggressive (not longer than timeout). 192 */ 193 dst = ip6_route_output(net, sk, fl6); 194 if (dst->error) { 195 IP6_INC_STATS(net, ip6_dst_idev(dst), 196 IPSTATS_MIB_OUTNOROUTES); 197 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { 198 res = true; 199 } else { 200 struct rt6_info *rt = (struct rt6_info *)dst; 201 int tmo = net->ipv6.sysctl.icmpv6_time; 202 struct inet_peer *peer; 203 204 /* Give more bandwidth to wider prefixes. */ 205 if (rt->rt6i_dst.plen < 128) 206 tmo >>= ((128 - rt->rt6i_dst.plen)>>5); 207 208 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1); 209 res = inet_peer_xrlim_allow(peer, tmo); 210 if (peer) 211 inet_putpeer(peer); 212 } 213 dst_release(dst); 214 return res; 215 } 216 217 /* 218 * an inline helper for the "simple" if statement below 219 * checks if parameter problem report is caused by an 220 * unrecognized IPv6 option that has the Option Type 221 * highest-order two bits set to 10 222 */ 223 224 static bool opt_unrec(struct sk_buff *skb, __u32 offset) 225 { 226 u8 _optval, *op; 227 228 offset += skb_network_offset(skb); 229 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); 230 if (op == NULL) 231 return true; 232 return (*op & 0xC0) == 0x80; 233 } 234 235 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, 236 struct icmp6hdr *thdr, int len) 237 { 238 struct sk_buff *skb; 239 struct icmp6hdr *icmp6h; 240 int err = 0; 241 242 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) 243 goto out; 244 245 icmp6h = icmp6_hdr(skb); 246 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); 247 icmp6h->icmp6_cksum = 0; 248 249 if (skb_queue_len(&sk->sk_write_queue) == 1) { 250 skb->csum = csum_partial(icmp6h, 251 sizeof(struct icmp6hdr), skb->csum); 252 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, 253 &fl6->daddr, 254 len, fl6->flowi6_proto, 255 skb->csum); 256 } else { 257 __wsum tmp_csum = 0; 258 259 skb_queue_walk(&sk->sk_write_queue, skb) { 260 tmp_csum = csum_add(tmp_csum, skb->csum); 261 } 262 263 tmp_csum = csum_partial(icmp6h, 264 sizeof(struct icmp6hdr), tmp_csum); 265 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, 266 &fl6->daddr, 267 len, fl6->flowi6_proto, 268 tmp_csum); 269 } 270 ip6_push_pending_frames(sk); 271 out: 272 return err; 273 } 274 275 struct icmpv6_msg { 276 struct sk_buff *skb; 277 int offset; 278 uint8_t type; 279 }; 280 281 static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) 282 { 283 struct icmpv6_msg *msg = (struct icmpv6_msg *) from; 284 struct sk_buff *org_skb = msg->skb; 285 __wsum csum = 0; 286 287 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, 288 to, len, csum); 289 skb->csum = csum_block_add(skb->csum, csum, odd); 290 if (!(msg->type & ICMPV6_INFOMSG_MASK)) 291 nf_ct_attach(skb, org_skb); 292 return 0; 293 } 294 295 #if IS_ENABLED(CONFIG_IPV6_MIP6) 296 static void mip6_addr_swap(struct sk_buff *skb) 297 { 298 struct ipv6hdr *iph = ipv6_hdr(skb); 299 struct inet6_skb_parm *opt = IP6CB(skb); 300 struct ipv6_destopt_hao *hao; 301 struct in6_addr tmp; 302 int off; 303 304 if (opt->dsthao) { 305 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); 306 if (likely(off >= 0)) { 307 hao = (struct ipv6_destopt_hao *) 308 (skb_network_header(skb) + off); 309 tmp = iph->saddr; 310 iph->saddr = hao->addr; 311 hao->addr = tmp; 312 } 313 } 314 } 315 #else 316 static inline void mip6_addr_swap(struct sk_buff *skb) {} 317 #endif 318 319 static struct dst_entry *icmpv6_route_lookup(struct net *net, 320 struct sk_buff *skb, 321 struct sock *sk, 322 struct flowi6 *fl6) 323 { 324 struct dst_entry *dst, *dst2; 325 struct flowi6 fl2; 326 int err; 327 328 err = ip6_dst_lookup(sk, &dst, fl6); 329 if (err) 330 return ERR_PTR(err); 331 332 /* 333 * We won't send icmp if the destination is known 334 * anycast. 335 */ 336 if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { 337 LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: acast source\n"); 338 dst_release(dst); 339 return ERR_PTR(-EINVAL); 340 } 341 342 /* No need to clone since we're just using its address. */ 343 dst2 = dst; 344 345 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0); 346 if (!IS_ERR(dst)) { 347 if (dst != dst2) 348 return dst; 349 } else { 350 if (PTR_ERR(dst) == -EPERM) 351 dst = NULL; 352 else 353 return dst; 354 } 355 356 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6); 357 if (err) 358 goto relookup_failed; 359 360 err = ip6_dst_lookup(sk, &dst2, &fl2); 361 if (err) 362 goto relookup_failed; 363 364 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP); 365 if (!IS_ERR(dst2)) { 366 dst_release(dst); 367 dst = dst2; 368 } else { 369 err = PTR_ERR(dst2); 370 if (err == -EPERM) { 371 dst_release(dst); 372 return dst2; 373 } else 374 goto relookup_failed; 375 } 376 377 relookup_failed: 378 if (dst) 379 return dst; 380 return ERR_PTR(err); 381 } 382 383 /* 384 * Send an ICMP message in response to a packet in error 385 */ 386 static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) 387 { 388 struct net *net = dev_net(skb->dev); 389 struct inet6_dev *idev = NULL; 390 struct ipv6hdr *hdr = ipv6_hdr(skb); 391 struct sock *sk; 392 struct ipv6_pinfo *np; 393 const struct in6_addr *saddr = NULL; 394 struct dst_entry *dst; 395 struct icmp6hdr tmp_hdr; 396 struct flowi6 fl6; 397 struct icmpv6_msg msg; 398 int iif = 0; 399 int addr_type = 0; 400 int len; 401 int hlimit; 402 int err = 0; 403 u32 mark = IP6_REPLY_MARK(net, skb->mark); 404 405 if ((u8 *)hdr < skb->head || 406 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb)) 407 return; 408 409 /* 410 * Make sure we respect the rules 411 * i.e. RFC 1885 2.4(e) 412 * Rule (e.1) is enforced by not using icmp6_send 413 * in any code that processes icmp errors. 414 */ 415 addr_type = ipv6_addr_type(&hdr->daddr); 416 417 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) || 418 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr)) 419 saddr = &hdr->daddr; 420 421 /* 422 * Dest addr check 423 */ 424 425 if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { 426 if (type != ICMPV6_PKT_TOOBIG && 427 !(type == ICMPV6_PARAMPROB && 428 code == ICMPV6_UNK_OPTION && 429 (opt_unrec(skb, info)))) 430 return; 431 432 saddr = NULL; 433 } 434 435 addr_type = ipv6_addr_type(&hdr->saddr); 436 437 /* 438 * Source addr check 439 */ 440 441 if (__ipv6_addr_needs_scope_id(addr_type)) 442 iif = skb->dev->ifindex; 443 444 /* 445 * Must not send error if the source does not uniquely 446 * identify a single node (RFC2463 Section 2.4). 447 * We check unspecified / multicast addresses here, 448 * and anycast addresses will be checked later. 449 */ 450 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { 451 LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: addr_any/mcast source\n"); 452 return; 453 } 454 455 /* 456 * Never answer to a ICMP packet. 457 */ 458 if (is_ineligible(skb)) { 459 LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: no reply to icmp error\n"); 460 return; 461 } 462 463 mip6_addr_swap(skb); 464 465 memset(&fl6, 0, sizeof(fl6)); 466 fl6.flowi6_proto = IPPROTO_ICMPV6; 467 fl6.daddr = hdr->saddr; 468 if (saddr) 469 fl6.saddr = *saddr; 470 fl6.flowi6_mark = mark; 471 fl6.flowi6_oif = iif; 472 fl6.fl6_icmp_type = type; 473 fl6.fl6_icmp_code = code; 474 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); 475 476 sk = icmpv6_xmit_lock(net); 477 if (sk == NULL) 478 return; 479 sk->sk_mark = mark; 480 np = inet6_sk(sk); 481 482 if (!icmpv6_xrlim_allow(sk, type, &fl6)) 483 goto out; 484 485 tmp_hdr.icmp6_type = type; 486 tmp_hdr.icmp6_code = code; 487 tmp_hdr.icmp6_cksum = 0; 488 tmp_hdr.icmp6_pointer = htonl(info); 489 490 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 491 fl6.flowi6_oif = np->mcast_oif; 492 else if (!fl6.flowi6_oif) 493 fl6.flowi6_oif = np->ucast_oif; 494 495 dst = icmpv6_route_lookup(net, skb, sk, &fl6); 496 if (IS_ERR(dst)) 497 goto out; 498 499 hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 500 501 msg.skb = skb; 502 msg.offset = skb_network_offset(skb); 503 msg.type = type; 504 505 len = skb->len - msg.offset; 506 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); 507 if (len < 0) { 508 LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); 509 goto out_dst_release; 510 } 511 512 rcu_read_lock(); 513 idev = __in6_dev_get(skb->dev); 514 515 err = ip6_append_data(sk, icmpv6_getfrag, &msg, 516 len + sizeof(struct icmp6hdr), 517 sizeof(struct icmp6hdr), hlimit, 518 np->tclass, NULL, &fl6, (struct rt6_info *)dst, 519 MSG_DONTWAIT, np->dontfrag); 520 if (err) { 521 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS); 522 ip6_flush_pending_frames(sk); 523 } else { 524 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, 525 len + sizeof(struct icmp6hdr)); 526 } 527 rcu_read_unlock(); 528 out_dst_release: 529 dst_release(dst); 530 out: 531 icmpv6_xmit_unlock(sk); 532 } 533 534 /* Slightly more convenient version of icmp6_send. 535 */ 536 void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) 537 { 538 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos); 539 kfree_skb(skb); 540 } 541 542 static void icmpv6_echo_reply(struct sk_buff *skb) 543 { 544 struct net *net = dev_net(skb->dev); 545 struct sock *sk; 546 struct inet6_dev *idev; 547 struct ipv6_pinfo *np; 548 const struct in6_addr *saddr = NULL; 549 struct icmp6hdr *icmph = icmp6_hdr(skb); 550 struct icmp6hdr tmp_hdr; 551 struct flowi6 fl6; 552 struct icmpv6_msg msg; 553 struct dst_entry *dst; 554 int err = 0; 555 int hlimit; 556 u8 tclass; 557 u32 mark = IP6_REPLY_MARK(net, skb->mark); 558 559 saddr = &ipv6_hdr(skb)->daddr; 560 561 if (!ipv6_unicast_destination(skb) && 562 !(net->ipv6.sysctl.anycast_src_echo_reply && 563 ipv6_anycast_destination(skb))) 564 saddr = NULL; 565 566 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); 567 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; 568 569 memset(&fl6, 0, sizeof(fl6)); 570 fl6.flowi6_proto = IPPROTO_ICMPV6; 571 fl6.daddr = ipv6_hdr(skb)->saddr; 572 if (saddr) 573 fl6.saddr = *saddr; 574 fl6.flowi6_oif = skb->dev->ifindex; 575 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY; 576 fl6.flowi6_mark = mark; 577 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); 578 579 sk = icmpv6_xmit_lock(net); 580 if (sk == NULL) 581 return; 582 sk->sk_mark = mark; 583 np = inet6_sk(sk); 584 585 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 586 fl6.flowi6_oif = np->mcast_oif; 587 else if (!fl6.flowi6_oif) 588 fl6.flowi6_oif = np->ucast_oif; 589 590 err = ip6_dst_lookup(sk, &dst, &fl6); 591 if (err) 592 goto out; 593 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); 594 if (IS_ERR(dst)) 595 goto out; 596 597 hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 598 599 idev = __in6_dev_get(skb->dev); 600 601 msg.skb = skb; 602 msg.offset = 0; 603 msg.type = ICMPV6_ECHO_REPLY; 604 605 tclass = ipv6_get_dsfield(ipv6_hdr(skb)); 606 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), 607 sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl6, 608 (struct rt6_info *)dst, MSG_DONTWAIT, 609 np->dontfrag); 610 611 if (err) { 612 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); 613 ip6_flush_pending_frames(sk); 614 } else { 615 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, 616 skb->len + sizeof(struct icmp6hdr)); 617 } 618 dst_release(dst); 619 out: 620 icmpv6_xmit_unlock(sk); 621 } 622 623 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) 624 { 625 const struct inet6_protocol *ipprot; 626 int inner_offset; 627 __be16 frag_off; 628 u8 nexthdr; 629 630 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 631 return; 632 633 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; 634 if (ipv6_ext_hdr(nexthdr)) { 635 /* now skip over extension headers */ 636 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), 637 &nexthdr, &frag_off); 638 if (inner_offset<0) 639 return; 640 } else { 641 inner_offset = sizeof(struct ipv6hdr); 642 } 643 644 /* Checkin header including 8 bytes of inner protocol header. */ 645 if (!pskb_may_pull(skb, inner_offset+8)) 646 return; 647 648 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. 649 Without this we will not able f.e. to make source routed 650 pmtu discovery. 651 Corresponding argument (opt) to notifiers is already added. 652 --ANK (980726) 653 */ 654 655 rcu_read_lock(); 656 ipprot = rcu_dereference(inet6_protos[nexthdr]); 657 if (ipprot && ipprot->err_handler) 658 ipprot->err_handler(skb, NULL, type, code, inner_offset, info); 659 rcu_read_unlock(); 660 661 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); 662 } 663 664 /* 665 * Handle icmp messages 666 */ 667 668 static int icmpv6_rcv(struct sk_buff *skb) 669 { 670 struct net_device *dev = skb->dev; 671 struct inet6_dev *idev = __in6_dev_get(dev); 672 const struct in6_addr *saddr, *daddr; 673 struct icmp6hdr *hdr; 674 u8 type; 675 676 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 677 struct sec_path *sp = skb_sec_path(skb); 678 int nh; 679 680 if (!(sp && sp->xvec[sp->len - 1]->props.flags & 681 XFRM_STATE_ICMP)) 682 goto drop_no_count; 683 684 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr))) 685 goto drop_no_count; 686 687 nh = skb_network_offset(skb); 688 skb_set_network_header(skb, sizeof(*hdr)); 689 690 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) 691 goto drop_no_count; 692 693 skb_set_network_header(skb, nh); 694 } 695 696 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS); 697 698 saddr = &ipv6_hdr(skb)->saddr; 699 daddr = &ipv6_hdr(skb)->daddr; 700 701 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) { 702 LIMIT_NETDEBUG(KERN_DEBUG 703 "ICMPv6 checksum failed [%pI6c > %pI6c]\n", 704 saddr, daddr); 705 goto csum_error; 706 } 707 708 if (!pskb_pull(skb, sizeof(*hdr))) 709 goto discard_it; 710 711 hdr = icmp6_hdr(skb); 712 713 type = hdr->icmp6_type; 714 715 ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type); 716 717 switch (type) { 718 case ICMPV6_ECHO_REQUEST: 719 icmpv6_echo_reply(skb); 720 break; 721 722 case ICMPV6_ECHO_REPLY: 723 ping_rcv(skb); 724 break; 725 726 case ICMPV6_PKT_TOOBIG: 727 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update 728 standard destination cache. Seems, only "advanced" 729 destination cache will allow to solve this problem 730 --ANK (980726) 731 */ 732 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 733 goto discard_it; 734 hdr = icmp6_hdr(skb); 735 736 /* 737 * Drop through to notify 738 */ 739 740 case ICMPV6_DEST_UNREACH: 741 case ICMPV6_TIME_EXCEED: 742 case ICMPV6_PARAMPROB: 743 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); 744 break; 745 746 case NDISC_ROUTER_SOLICITATION: 747 case NDISC_ROUTER_ADVERTISEMENT: 748 case NDISC_NEIGHBOUR_SOLICITATION: 749 case NDISC_NEIGHBOUR_ADVERTISEMENT: 750 case NDISC_REDIRECT: 751 ndisc_rcv(skb); 752 break; 753 754 case ICMPV6_MGM_QUERY: 755 igmp6_event_query(skb); 756 break; 757 758 case ICMPV6_MGM_REPORT: 759 igmp6_event_report(skb); 760 break; 761 762 case ICMPV6_MGM_REDUCTION: 763 case ICMPV6_NI_QUERY: 764 case ICMPV6_NI_REPLY: 765 case ICMPV6_MLD2_REPORT: 766 case ICMPV6_DHAAD_REQUEST: 767 case ICMPV6_DHAAD_REPLY: 768 case ICMPV6_MOBILE_PREFIX_SOL: 769 case ICMPV6_MOBILE_PREFIX_ADV: 770 break; 771 772 default: 773 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); 774 775 /* informational */ 776 if (type & ICMPV6_INFOMSG_MASK) 777 break; 778 779 /* 780 * error of unknown type. 781 * must pass to upper level 782 */ 783 784 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); 785 } 786 787 kfree_skb(skb); 788 return 0; 789 790 csum_error: 791 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS); 792 discard_it: 793 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS); 794 drop_no_count: 795 kfree_skb(skb); 796 return 0; 797 } 798 799 void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6, 800 u8 type, 801 const struct in6_addr *saddr, 802 const struct in6_addr *daddr, 803 int oif) 804 { 805 memset(fl6, 0, sizeof(*fl6)); 806 fl6->saddr = *saddr; 807 fl6->daddr = *daddr; 808 fl6->flowi6_proto = IPPROTO_ICMPV6; 809 fl6->fl6_icmp_type = type; 810 fl6->fl6_icmp_code = 0; 811 fl6->flowi6_oif = oif; 812 security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); 813 } 814 815 /* 816 * Special lock-class for __icmpv6_sk: 817 */ 818 static struct lock_class_key icmpv6_socket_sk_dst_lock_key; 819 820 static int __net_init icmpv6_sk_init(struct net *net) 821 { 822 struct sock *sk; 823 int err, i, j; 824 825 net->ipv6.icmp_sk = 826 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); 827 if (net->ipv6.icmp_sk == NULL) 828 return -ENOMEM; 829 830 for_each_possible_cpu(i) { 831 err = inet_ctl_sock_create(&sk, PF_INET6, 832 SOCK_RAW, IPPROTO_ICMPV6, net); 833 if (err < 0) { 834 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n", 835 err); 836 goto fail; 837 } 838 839 net->ipv6.icmp_sk[i] = sk; 840 841 /* 842 * Split off their lock-class, because sk->sk_dst_lock 843 * gets used from softirqs, which is safe for 844 * __icmpv6_sk (because those never get directly used 845 * via userspace syscalls), but unsafe for normal sockets. 846 */ 847 lockdep_set_class(&sk->sk_dst_lock, 848 &icmpv6_socket_sk_dst_lock_key); 849 850 /* Enough space for 2 64K ICMP packets, including 851 * sk_buff struct overhead. 852 */ 853 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); 854 } 855 return 0; 856 857 fail: 858 for (j = 0; j < i; j++) 859 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]); 860 kfree(net->ipv6.icmp_sk); 861 return err; 862 } 863 864 static void __net_exit icmpv6_sk_exit(struct net *net) 865 { 866 int i; 867 868 for_each_possible_cpu(i) { 869 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]); 870 } 871 kfree(net->ipv6.icmp_sk); 872 } 873 874 static struct pernet_operations icmpv6_sk_ops = { 875 .init = icmpv6_sk_init, 876 .exit = icmpv6_sk_exit, 877 }; 878 879 int __init icmpv6_init(void) 880 { 881 int err; 882 883 err = register_pernet_subsys(&icmpv6_sk_ops); 884 if (err < 0) 885 return err; 886 887 err = -EAGAIN; 888 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) 889 goto fail; 890 891 err = inet6_register_icmp_sender(icmp6_send); 892 if (err) 893 goto sender_reg_err; 894 return 0; 895 896 sender_reg_err: 897 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); 898 fail: 899 pr_err("Failed to register ICMP6 protocol\n"); 900 unregister_pernet_subsys(&icmpv6_sk_ops); 901 return err; 902 } 903 904 void icmpv6_cleanup(void) 905 { 906 inet6_unregister_icmp_sender(icmp6_send); 907 unregister_pernet_subsys(&icmpv6_sk_ops); 908 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); 909 } 910 911 912 static const struct icmp6_err { 913 int err; 914 int fatal; 915 } tab_unreach[] = { 916 { /* NOROUTE */ 917 .err = ENETUNREACH, 918 .fatal = 0, 919 }, 920 { /* ADM_PROHIBITED */ 921 .err = EACCES, 922 .fatal = 1, 923 }, 924 { /* Was NOT_NEIGHBOUR, now reserved */ 925 .err = EHOSTUNREACH, 926 .fatal = 0, 927 }, 928 { /* ADDR_UNREACH */ 929 .err = EHOSTUNREACH, 930 .fatal = 0, 931 }, 932 { /* PORT_UNREACH */ 933 .err = ECONNREFUSED, 934 .fatal = 1, 935 }, 936 { /* POLICY_FAIL */ 937 .err = EACCES, 938 .fatal = 1, 939 }, 940 { /* REJECT_ROUTE */ 941 .err = EACCES, 942 .fatal = 1, 943 }, 944 }; 945 946 int icmpv6_err_convert(u8 type, u8 code, int *err) 947 { 948 int fatal = 0; 949 950 *err = EPROTO; 951 952 switch (type) { 953 case ICMPV6_DEST_UNREACH: 954 fatal = 1; 955 if (code < ARRAY_SIZE(tab_unreach)) { 956 *err = tab_unreach[code].err; 957 fatal = tab_unreach[code].fatal; 958 } 959 break; 960 961 case ICMPV6_PKT_TOOBIG: 962 *err = EMSGSIZE; 963 break; 964 965 case ICMPV6_PARAMPROB: 966 *err = EPROTO; 967 fatal = 1; 968 break; 969 970 case ICMPV6_TIME_EXCEED: 971 *err = EHOSTUNREACH; 972 break; 973 } 974 975 return fatal; 976 } 977 EXPORT_SYMBOL(icmpv6_err_convert); 978 979 #ifdef CONFIG_SYSCTL 980 static struct ctl_table ipv6_icmp_table_template[] = { 981 { 982 .procname = "ratelimit", 983 .data = &init_net.ipv6.sysctl.icmpv6_time, 984 .maxlen = sizeof(int), 985 .mode = 0644, 986 .proc_handler = proc_dointvec_ms_jiffies, 987 }, 988 { }, 989 }; 990 991 struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) 992 { 993 struct ctl_table *table; 994 995 table = kmemdup(ipv6_icmp_table_template, 996 sizeof(ipv6_icmp_table_template), 997 GFP_KERNEL); 998 999 if (table) 1000 table[0].data = &net->ipv6.sysctl.icmpv6_time; 1001 1002 return table; 1003 } 1004 #endif 1005 1006