1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Internet Control Message Protocol (ICMPv6) 4 * Linux INET6 implementation 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * 9 * Based on net/ipv4/icmp.c 10 * 11 * RFC 1885 12 */ 13 14 /* 15 * Changes: 16 * 17 * Andi Kleen : exception handling 18 * Andi Kleen add rate limits. never reply to a icmp. 19 * add more length checks and other fixes. 20 * yoshfuji : ensure to sent parameter problem for 21 * fragments. 22 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit. 23 * Randy Dunlap and 24 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support 25 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data 26 */ 27 28 #define pr_fmt(fmt) "IPv6: " fmt 29 30 #include <linux/module.h> 31 #include <linux/errno.h> 32 #include <linux/types.h> 33 #include <linux/socket.h> 34 #include <linux/in.h> 35 #include <linux/kernel.h> 36 #include <linux/sockios.h> 37 #include <linux/net.h> 38 #include <linux/skbuff.h> 39 #include <linux/init.h> 40 #include <linux/netfilter.h> 41 #include <linux/slab.h> 42 43 #ifdef CONFIG_SYSCTL 44 #include <linux/sysctl.h> 45 #endif 46 47 #include <linux/inet.h> 48 #include <linux/netdevice.h> 49 #include <linux/icmpv6.h> 50 51 #include <net/ip.h> 52 #include <net/sock.h> 53 54 #include <net/ipv6.h> 55 #include <net/ip6_checksum.h> 56 #include <net/ping.h> 57 #include <net/protocol.h> 58 #include <net/raw.h> 59 #include <net/rawv6.h> 60 #include <net/seg6.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 #include <net/dsfield.h> 68 #include <net/l3mdev.h> 69 70 #include <linux/uaccess.h> 71 72 static DEFINE_PER_CPU(struct sock *, ipv6_icmp_sk); 73 74 static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 75 u8 type, u8 code, int offset, __be32 info) 76 { 77 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */ 78 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset); 79 struct net *net = dev_net_rcu(skb->dev); 80 81 if (type == ICMPV6_PKT_TOOBIG) 82 ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL)); 83 else if (type == NDISC_REDIRECT) 84 ip6_redirect(skb, net, skb->dev->ifindex, 0, 85 sock_net_uid(net, NULL)); 86 87 if (!(type & ICMPV6_INFOMSG_MASK)) 88 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST) 89 ping_err(skb, offset, ntohl(info)); 90 91 return 0; 92 } 93 94 static int icmpv6_rcv(struct sk_buff *skb); 95 96 static const struct inet6_protocol icmpv6_protocol = { 97 .handler = icmpv6_rcv, 98 .err_handler = icmpv6_err, 99 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 100 }; 101 102 /* Called with BH disabled */ 103 static struct sock *icmpv6_xmit_lock(struct net *net) 104 { 105 struct sock *sk; 106 107 sk = this_cpu_read(ipv6_icmp_sk); 108 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { 109 /* This can happen if the output path (f.e. SIT or 110 * ip6ip6 tunnel) signals dst_link_failure() for an 111 * outgoing ICMP6 packet. 112 */ 113 return NULL; 114 } 115 sock_net_set(sk, net); 116 return sk; 117 } 118 119 static void icmpv6_xmit_unlock(struct sock *sk) 120 { 121 sock_net_set(sk, &init_net); 122 spin_unlock(&sk->sk_lock.slock); 123 } 124 125 /* 126 * Figure out, may we reply to this packet with icmp error. 127 * 128 * We do not reply, if: 129 * - it was icmp error message. 130 * - it is truncated, so that it is known, that protocol is ICMPV6 131 * (i.e. in the middle of some exthdr) 132 * 133 * --ANK (980726) 134 */ 135 136 static bool is_ineligible(const struct sk_buff *skb) 137 { 138 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; 139 int len = skb->len - ptr; 140 __u8 nexthdr = ipv6_hdr(skb)->nexthdr; 141 __be16 frag_off; 142 143 if (len < 0) 144 return true; 145 146 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off); 147 if (ptr < 0) 148 return false; 149 if (nexthdr == IPPROTO_ICMPV6) { 150 u8 _type, *tp; 151 tp = skb_header_pointer(skb, 152 ptr+offsetof(struct icmp6hdr, icmp6_type), 153 sizeof(_type), &_type); 154 155 /* Based on RFC 8200, Section 4.5 Fragment Header, return 156 * false if this is a fragment packet with no icmp header info. 157 */ 158 if (!tp && frag_off != 0) 159 return false; 160 else if (!tp || !(*tp & ICMPV6_INFOMSG_MASK)) 161 return true; 162 } 163 return false; 164 } 165 166 static bool icmpv6_mask_allow(struct net *net, int type) 167 { 168 if (type > ICMPV6_MSG_MAX) 169 return true; 170 171 /* Limit if icmp type is set in ratemask. */ 172 if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask)) 173 return true; 174 175 return false; 176 } 177 178 static bool icmpv6_global_allow(struct net *net, int type, 179 bool *apply_ratelimit) 180 { 181 if (icmpv6_mask_allow(net, type)) 182 return true; 183 184 if (icmp_global_allow(net)) { 185 *apply_ratelimit = true; 186 return true; 187 } 188 __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); 189 return false; 190 } 191 192 /* 193 * Check the ICMP output rate limit 194 */ 195 static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, 196 struct flowi6 *fl6, bool apply_ratelimit) 197 { 198 struct net *net = sock_net(sk); 199 struct net_device *dev; 200 struct dst_entry *dst; 201 bool res = false; 202 203 if (!apply_ratelimit) 204 return true; 205 206 /* 207 * Look up the output route. 208 * XXX: perhaps the expire for routing entries cloned by 209 * this lookup should be more aggressive (not longer than timeout). 210 */ 211 dst = ip6_route_output(net, sk, fl6); 212 rcu_read_lock(); 213 dev = dst_dev_rcu(dst); 214 if (dst->error) { 215 IP6_INC_STATS(net, ip6_dst_idev(dst), 216 IPSTATS_MIB_OUTNOROUTES); 217 } else if (dev && (dev->flags & IFF_LOOPBACK)) { 218 res = true; 219 } else { 220 int tmo = READ_ONCE(net->ipv6.sysctl.icmpv6_time); 221 struct inet_peer *peer; 222 223 if (!tmo) { 224 res = true; 225 } else { 226 peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr); 227 res = inet_peer_xrlim_allow(peer, tmo); 228 } 229 } 230 rcu_read_unlock(); 231 if (!res) 232 __ICMP6_INC_STATS(net, NULL, ICMP6_MIB_RATELIMITHOST); 233 else 234 icmp_global_consume(net); 235 dst_release(dst); 236 return res; 237 } 238 239 static bool icmpv6_rt_has_prefsrc(struct sock *sk, u8 type, 240 struct flowi6 *fl6) 241 { 242 struct net *net = sock_net(sk); 243 struct dst_entry *dst; 244 bool res = false; 245 246 dst = ip6_route_output(net, sk, fl6); 247 if (!dst->error) { 248 struct rt6_info *rt = dst_rt6_info(dst); 249 struct in6_addr prefsrc; 250 251 rt6_get_prefsrc(rt, &prefsrc); 252 res = !ipv6_addr_any(&prefsrc); 253 } 254 dst_release(dst); 255 return res; 256 } 257 258 /* 259 * an inline helper for the "simple" if statement below 260 * checks if parameter problem report is caused by an 261 * unrecognized IPv6 option that has the Option Type 262 * highest-order two bits set to 10 263 */ 264 265 static bool opt_unrec(struct sk_buff *skb, __u32 offset) 266 { 267 u8 _optval, *op; 268 269 offset += skb_network_offset(skb); 270 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); 271 if (!op) 272 return true; 273 return (*op & 0xC0) == 0x80; 274 } 275 276 void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, 277 struct icmp6hdr *thdr, int len) 278 { 279 struct sk_buff *skb; 280 struct icmp6hdr *icmp6h; 281 282 skb = skb_peek(&sk->sk_write_queue); 283 if (!skb) 284 return; 285 286 icmp6h = icmp6_hdr(skb); 287 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); 288 icmp6h->icmp6_cksum = 0; 289 290 if (skb_queue_len(&sk->sk_write_queue) == 1) { 291 skb->csum = csum_partial(icmp6h, 292 sizeof(struct icmp6hdr), skb->csum); 293 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, 294 &fl6->daddr, 295 len, fl6->flowi6_proto, 296 skb->csum); 297 } else { 298 __wsum tmp_csum = 0; 299 300 skb_queue_walk(&sk->sk_write_queue, skb) { 301 tmp_csum = csum_add(tmp_csum, skb->csum); 302 } 303 304 tmp_csum = csum_partial(icmp6h, 305 sizeof(struct icmp6hdr), tmp_csum); 306 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, 307 &fl6->daddr, 308 len, fl6->flowi6_proto, 309 tmp_csum); 310 } 311 ip6_push_pending_frames(sk); 312 } 313 314 struct icmpv6_msg { 315 struct sk_buff *skb; 316 int offset; 317 uint8_t type; 318 }; 319 320 static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) 321 { 322 struct icmpv6_msg *msg = (struct icmpv6_msg *) from; 323 struct sk_buff *org_skb = msg->skb; 324 __wsum csum; 325 326 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, 327 to, len); 328 skb->csum = csum_block_add(skb->csum, csum, odd); 329 if (!(msg->type & ICMPV6_INFOMSG_MASK)) 330 nf_ct_attach(skb, org_skb); 331 return 0; 332 } 333 334 #if IS_ENABLED(CONFIG_IPV6_MIP6) 335 static void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) 336 { 337 struct ipv6hdr *iph = ipv6_hdr(skb); 338 struct ipv6_destopt_hao *hao; 339 int off; 340 341 if (opt->dsthao) { 342 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); 343 if (likely(off >= 0)) { 344 hao = (struct ipv6_destopt_hao *) 345 (skb_network_header(skb) + off); 346 swap(iph->saddr, hao->addr); 347 } 348 } 349 } 350 #else 351 static inline void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) {} 352 #endif 353 354 static struct dst_entry *icmpv6_route_lookup(struct net *net, 355 struct sk_buff *skb, 356 struct sock *sk, 357 struct flowi6 *fl6) 358 { 359 struct dst_entry *dst, *dst2; 360 struct flowi6 fl2; 361 int err; 362 363 err = ip6_dst_lookup(net, sk, &dst, fl6); 364 if (err) 365 return ERR_PTR(err); 366 367 /* 368 * We won't send icmp if the destination is known 369 * anycast unless we need to treat anycast as unicast. 370 */ 371 if (!READ_ONCE(net->ipv6.sysctl.icmpv6_error_anycast_as_unicast) && 372 ipv6_anycast_destination(dst, &fl6->daddr)) { 373 net_dbg_ratelimited("icmp6_send: acast source\n"); 374 dst_release(dst); 375 return ERR_PTR(-EINVAL); 376 } 377 378 /* No need to clone since we're just using its address. */ 379 dst2 = dst; 380 381 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0); 382 if (!IS_ERR(dst)) { 383 if (dst != dst2) 384 return dst; 385 } else { 386 if (PTR_ERR(dst) == -EPERM) 387 dst = NULL; 388 else 389 return dst; 390 } 391 392 err = xfrm_decode_session_reverse(net, skb, flowi6_to_flowi(&fl2), AF_INET6); 393 if (err) 394 goto relookup_failed; 395 396 err = ip6_dst_lookup(net, sk, &dst2, &fl2); 397 if (err) 398 goto relookup_failed; 399 400 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP); 401 if (!IS_ERR(dst2)) { 402 dst_release(dst); 403 dst = dst2; 404 } else { 405 err = PTR_ERR(dst2); 406 if (err == -EPERM) { 407 dst_release(dst); 408 return dst2; 409 } else 410 goto relookup_failed; 411 } 412 413 relookup_failed: 414 if (dst) 415 return dst; 416 return ERR_PTR(err); 417 } 418 419 static struct net_device *icmp6_dev(const struct sk_buff *skb) 420 { 421 struct net_device *dev = skb->dev; 422 423 /* for local traffic to local address, skb dev is the loopback 424 * device. Check if there is a dst attached to the skb and if so 425 * get the real device index. Same is needed for replies to a link 426 * local address on a device enslaved to an L3 master device 427 */ 428 if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) { 429 const struct rt6_info *rt6 = skb_rt6_info(skb); 430 431 /* The destination could be an external IP in Ext Hdr (SRv6, RPL, etc.), 432 * and ip6_null_entry could be set to skb if no route is found. 433 */ 434 if (rt6 && rt6->rt6i_idev) 435 dev = rt6->rt6i_idev->dev; 436 } 437 438 return dev; 439 } 440 441 static int icmp6_iif(const struct sk_buff *skb) 442 { 443 return icmp6_dev(skb)->ifindex; 444 } 445 446 struct icmp6_ext_iio_addr6_subobj { 447 __be16 afi; 448 __be16 reserved; 449 struct in6_addr addr6; 450 }; 451 452 static unsigned int icmp6_ext_iio_len(void) 453 { 454 return sizeof(struct icmp_extobj_hdr) + 455 /* ifIndex */ 456 sizeof(__be32) + 457 /* Interface Address Sub-Object */ 458 sizeof(struct icmp6_ext_iio_addr6_subobj) + 459 /* Interface Name Sub-Object. Length must be a multiple of 4 460 * bytes. 461 */ 462 ALIGN(sizeof(struct icmp_ext_iio_name_subobj), 4) + 463 /* MTU */ 464 sizeof(__be32); 465 } 466 467 static unsigned int icmp6_ext_max_len(u8 ext_objs) 468 { 469 unsigned int ext_max_len; 470 471 ext_max_len = sizeof(struct icmp_ext_hdr); 472 473 if (ext_objs & BIT(ICMP_ERR_EXT_IIO_IIF)) 474 ext_max_len += icmp6_ext_iio_len(); 475 476 return ext_max_len; 477 } 478 479 static struct in6_addr *icmp6_ext_iio_addr6_find(const struct net_device *dev) 480 { 481 struct inet6_dev *in6_dev; 482 struct inet6_ifaddr *ifa; 483 484 in6_dev = __in6_dev_get(dev); 485 if (!in6_dev) 486 return NULL; 487 488 /* It is unclear from RFC 5837 which IP address should be chosen, but 489 * it makes sense to choose a global unicast address. 490 */ 491 list_for_each_entry_rcu(ifa, &in6_dev->addr_list, if_list) { 492 if (ifa->flags & (IFA_F_TENTATIVE | IFA_F_DADFAILED)) 493 continue; 494 if (ipv6_addr_type(&ifa->addr) != IPV6_ADDR_UNICAST || 495 ipv6_addr_src_scope(&ifa->addr) != IPV6_ADDR_SCOPE_GLOBAL) 496 continue; 497 return &ifa->addr; 498 } 499 500 return NULL; 501 } 502 503 static void icmp6_ext_iio_iif_append(struct net *net, struct sk_buff *skb, 504 int iif) 505 { 506 struct icmp_ext_iio_name_subobj *name_subobj; 507 struct icmp_extobj_hdr *objh; 508 struct net_device *dev; 509 struct in6_addr *addr6; 510 __be32 data; 511 512 if (!iif) 513 return; 514 515 /* Add the fields in the order specified by RFC 5837. */ 516 objh = skb_put(skb, sizeof(*objh)); 517 objh->class_num = ICMP_EXT_OBJ_CLASS_IIO; 518 objh->class_type = ICMP_EXT_CTYPE_IIO_ROLE(ICMP_EXT_CTYPE_IIO_ROLE_IIF); 519 520 data = htonl(iif); 521 skb_put_data(skb, &data, sizeof(__be32)); 522 objh->class_type |= ICMP_EXT_CTYPE_IIO_IFINDEX; 523 524 rcu_read_lock(); 525 526 dev = dev_get_by_index_rcu(net, iif); 527 if (!dev) 528 goto out; 529 530 addr6 = icmp6_ext_iio_addr6_find(dev); 531 if (addr6) { 532 struct icmp6_ext_iio_addr6_subobj *addr6_subobj; 533 534 addr6_subobj = skb_put_zero(skb, sizeof(*addr6_subobj)); 535 addr6_subobj->afi = htons(ICMP_AFI_IP6); 536 addr6_subobj->addr6 = *addr6; 537 objh->class_type |= ICMP_EXT_CTYPE_IIO_IPADDR; 538 } 539 540 name_subobj = skb_put_zero(skb, ALIGN(sizeof(*name_subobj), 4)); 541 name_subobj->len = ALIGN(sizeof(*name_subobj), 4); 542 netdev_copy_name(dev, name_subobj->name); 543 objh->class_type |= ICMP_EXT_CTYPE_IIO_NAME; 544 545 data = htonl(READ_ONCE(dev->mtu)); 546 skb_put_data(skb, &data, sizeof(__be32)); 547 objh->class_type |= ICMP_EXT_CTYPE_IIO_MTU; 548 549 out: 550 rcu_read_unlock(); 551 objh->length = htons(skb_tail_pointer(skb) - (unsigned char *)objh); 552 } 553 554 static void icmp6_ext_objs_append(struct net *net, struct sk_buff *skb, 555 u8 ext_objs, int iif) 556 { 557 if (ext_objs & BIT(ICMP_ERR_EXT_IIO_IIF)) 558 icmp6_ext_iio_iif_append(net, skb, iif); 559 } 560 561 static struct sk_buff * 562 icmp6_ext_append(struct net *net, struct sk_buff *skb_in, 563 struct icmp6hdr *icmp6h, unsigned int room, int iif) 564 { 565 unsigned int payload_len, ext_max_len, ext_len; 566 struct icmp_ext_hdr *ext_hdr; 567 struct sk_buff *skb; 568 u8 ext_objs; 569 int nhoff; 570 571 switch (icmp6h->icmp6_type) { 572 case ICMPV6_DEST_UNREACH: 573 case ICMPV6_TIME_EXCEED: 574 break; 575 default: 576 return NULL; 577 } 578 579 /* Do not overwrite existing extensions. This can happen when we 580 * receive an ICMPv4 message with extensions from a tunnel and 581 * translate it to an ICMPv6 message towards an IPv6 host in the 582 * overlay network. 583 */ 584 if (icmp6h->icmp6_datagram_len) 585 return NULL; 586 587 ext_objs = READ_ONCE(net->ipv6.sysctl.icmpv6_errors_extension_mask); 588 if (!ext_objs) 589 return NULL; 590 591 ext_max_len = icmp6_ext_max_len(ext_objs); 592 if (ICMP_EXT_ORIG_DGRAM_MIN_LEN + ext_max_len > room) 593 return NULL; 594 595 skb = skb_clone(skb_in, GFP_ATOMIC); 596 if (!skb) 597 return NULL; 598 599 nhoff = skb_network_offset(skb); 600 payload_len = min(skb->len - nhoff, ICMP_EXT_ORIG_DGRAM_MIN_LEN); 601 602 if (!pskb_network_may_pull(skb, payload_len)) 603 goto free_skb; 604 605 if (pskb_trim(skb, nhoff + ICMP_EXT_ORIG_DGRAM_MIN_LEN) || 606 __skb_put_padto(skb, nhoff + ICMP_EXT_ORIG_DGRAM_MIN_LEN, false)) 607 goto free_skb; 608 609 if (pskb_expand_head(skb, 0, ext_max_len, GFP_ATOMIC)) 610 goto free_skb; 611 612 ext_hdr = skb_put_zero(skb, sizeof(*ext_hdr)); 613 ext_hdr->version = ICMP_EXT_VERSION_2; 614 615 icmp6_ext_objs_append(net, skb, ext_objs, iif); 616 617 /* Do not send an empty extension structure. */ 618 ext_len = skb_tail_pointer(skb) - (unsigned char *)ext_hdr; 619 if (ext_len == sizeof(*ext_hdr)) 620 goto free_skb; 621 622 ext_hdr->checksum = ip_compute_csum(ext_hdr, ext_len); 623 /* The length of the original datagram in 64-bit words (RFC 4884). */ 624 icmp6h->icmp6_datagram_len = ICMP_EXT_ORIG_DGRAM_MIN_LEN / sizeof(u64); 625 626 return skb; 627 628 free_skb: 629 consume_skb(skb); 630 return NULL; 631 } 632 633 /* 634 * Send an ICMP message in response to a packet in error 635 */ 636 void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, 637 const struct in6_addr *force_saddr, 638 const struct inet6_skb_parm *parm) 639 { 640 struct inet6_dev *idev = NULL; 641 struct ipv6hdr *hdr = ipv6_hdr(skb); 642 struct sock *sk; 643 struct net *net; 644 struct ipv6_pinfo *np; 645 const struct in6_addr *saddr = NULL; 646 bool apply_ratelimit = false; 647 struct sk_buff *ext_skb; 648 struct dst_entry *dst; 649 unsigned int room; 650 struct icmp6hdr tmp_hdr; 651 struct flowi6 fl6; 652 struct icmpv6_msg msg; 653 struct ipcm6_cookie ipc6; 654 int iif = 0; 655 int addr_type = 0; 656 int len; 657 u32 mark; 658 659 if ((u8 *)hdr < skb->head || 660 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb)) 661 return; 662 663 if (!skb->dev) 664 return; 665 666 rcu_read_lock(); 667 668 net = dev_net_rcu(skb->dev); 669 mark = IP6_REPLY_MARK(net, skb->mark); 670 /* 671 * Make sure we respect the rules 672 * i.e. RFC 1885 2.4(e) 673 * Rule (e.1) is enforced by not using icmp6_send 674 * in any code that processes icmp errors. 675 */ 676 addr_type = ipv6_addr_type(&hdr->daddr); 677 678 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) || 679 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr)) 680 saddr = &hdr->daddr; 681 682 /* 683 * Dest addr check 684 */ 685 686 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) { 687 if (type != ICMPV6_PKT_TOOBIG && 688 !(type == ICMPV6_PARAMPROB && 689 code == ICMPV6_UNK_OPTION && 690 (opt_unrec(skb, info)))) 691 goto out; 692 693 saddr = NULL; 694 } 695 696 addr_type = ipv6_addr_type(&hdr->saddr); 697 698 /* 699 * Source addr check 700 */ 701 702 if (__ipv6_addr_needs_scope_id(addr_type)) { 703 iif = icmp6_iif(skb); 704 } else { 705 /* 706 * The source device is used for looking up which routing table 707 * to use for sending an ICMP error. 708 */ 709 iif = l3mdev_master_ifindex(skb->dev); 710 } 711 712 /* 713 * Must not send error if the source does not uniquely 714 * identify a single node (RFC2463 Section 2.4). 715 * We check unspecified / multicast addresses here, 716 * and anycast addresses will be checked later. 717 */ 718 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { 719 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n", 720 &hdr->saddr, &hdr->daddr); 721 goto out; 722 } 723 724 /* 725 * Never answer to a ICMP packet. 726 */ 727 if (is_ineligible(skb)) { 728 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n", 729 &hdr->saddr, &hdr->daddr); 730 goto out; 731 } 732 733 /* Needed by both icmpv6_global_allow and icmpv6_xmit_lock */ 734 local_bh_disable(); 735 736 /* Check global sysctl_icmp_msgs_per_sec ratelimit */ 737 if (!(skb->dev->flags & IFF_LOOPBACK) && 738 !icmpv6_global_allow(net, type, &apply_ratelimit)) 739 goto out_bh_enable; 740 741 mip6_addr_swap(skb, parm); 742 743 sk = icmpv6_xmit_lock(net); 744 if (!sk) 745 goto out_bh_enable; 746 747 memset(&fl6, 0, sizeof(fl6)); 748 fl6.flowi6_proto = IPPROTO_ICMPV6; 749 fl6.daddr = hdr->saddr; 750 if (force_saddr) 751 saddr = force_saddr; 752 if (saddr) { 753 fl6.saddr = *saddr; 754 } else if (!icmpv6_rt_has_prefsrc(sk, type, &fl6)) { 755 /* select a more meaningful saddr from input if */ 756 struct net_device *in_netdev; 757 758 in_netdev = dev_get_by_index(net, parm->iif); 759 if (in_netdev) { 760 ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr, 761 inet6_sk(sk)->srcprefs, 762 &fl6.saddr); 763 dev_put(in_netdev); 764 } 765 } 766 fl6.flowi6_mark = mark; 767 fl6.flowi6_oif = iif; 768 fl6.fl6_icmp_type = type; 769 fl6.fl6_icmp_code = code; 770 fl6.flowi6_uid = sock_net_uid(net, NULL); 771 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL); 772 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6)); 773 774 np = inet6_sk(sk); 775 776 if (!icmpv6_xrlim_allow(sk, type, &fl6, apply_ratelimit)) 777 goto out_unlock; 778 779 tmp_hdr.icmp6_type = type; 780 tmp_hdr.icmp6_code = code; 781 tmp_hdr.icmp6_cksum = 0; 782 tmp_hdr.icmp6_pointer = htonl(info); 783 784 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 785 fl6.flowi6_oif = READ_ONCE(np->mcast_oif); 786 else if (!fl6.flowi6_oif) 787 fl6.flowi6_oif = READ_ONCE(np->ucast_oif); 788 789 ipcm6_init_sk(&ipc6, sk); 790 ipc6.sockc.mark = mark; 791 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 792 793 dst = icmpv6_route_lookup(net, skb, sk, &fl6); 794 if (IS_ERR(dst)) 795 goto out_unlock; 796 797 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 798 799 msg.skb = skb; 800 msg.offset = skb_network_offset(skb); 801 msg.type = type; 802 803 room = IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr); 804 ext_skb = icmp6_ext_append(net, skb, &tmp_hdr, room, parm->iif); 805 if (ext_skb) 806 msg.skb = ext_skb; 807 808 len = msg.skb->len - msg.offset; 809 len = min_t(unsigned int, len, room); 810 if (len < 0) { 811 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n", 812 &hdr->saddr, &hdr->daddr); 813 goto out_dst_release; 814 } 815 816 idev = __in6_dev_get(skb->dev); 817 818 if (ip6_append_data(sk, icmpv6_getfrag, &msg, 819 len + sizeof(struct icmp6hdr), 820 sizeof(struct icmp6hdr), 821 &ipc6, &fl6, dst_rt6_info(dst), 822 MSG_DONTWAIT)) { 823 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS); 824 ip6_flush_pending_frames(sk); 825 } else { 826 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, 827 len + sizeof(struct icmp6hdr)); 828 } 829 830 out_dst_release: 831 if (ext_skb) 832 consume_skb(ext_skb); 833 dst_release(dst); 834 out_unlock: 835 icmpv6_xmit_unlock(sk); 836 out_bh_enable: 837 local_bh_enable(); 838 out: 839 rcu_read_unlock(); 840 } 841 EXPORT_SYMBOL(icmp6_send); 842 843 /* Slightly more convenient version of icmp6_send with drop reasons. 844 */ 845 void icmpv6_param_prob_reason(struct sk_buff *skb, u8 code, int pos, 846 enum skb_drop_reason reason) 847 { 848 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb)); 849 kfree_skb_reason(skb, reason); 850 } 851 852 /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH 853 * if sufficient data bytes are available 854 * @nhs is the size of the tunnel header(s) : 855 * Either an IPv4 header for SIT encap 856 * an IPv4 header + GRE header for GRE encap 857 */ 858 int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type, 859 unsigned int data_len) 860 { 861 struct in6_addr temp_saddr; 862 struct rt6_info *rt; 863 struct sk_buff *skb2; 864 u32 info = 0; 865 866 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8)) 867 return 1; 868 869 /* RFC 4884 (partial) support for ICMP extensions */ 870 if (data_len < 128 || (data_len & 7) || skb->len < data_len) 871 data_len = 0; 872 873 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC); 874 875 if (!skb2) 876 return 1; 877 878 /* Remove debris left by IPv4 stack. */ 879 memset(IP6CB(skb2), 0, sizeof(*IP6CB(skb2))); 880 881 skb_dst_drop(skb2); 882 skb_pull(skb2, nhs); 883 skb_reset_network_header(skb2); 884 885 rt = rt6_lookup(dev_net_rcu(skb->dev), &ipv6_hdr(skb2)->saddr, 886 NULL, 0, skb, 0); 887 888 if (rt && rt->dst.dev) 889 skb2->dev = rt->dst.dev; 890 891 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr); 892 893 if (data_len) { 894 /* RFC 4884 (partial) support : 895 * insert 0 padding at the end, before the extensions 896 */ 897 __skb_push(skb2, nhs); 898 skb_reset_network_header(skb2); 899 memmove(skb2->data, skb2->data + nhs, data_len - nhs); 900 memset(skb2->data + data_len - nhs, 0, nhs); 901 /* RFC 4884 4.5 : Length is measured in 64-bit words, 902 * and stored in reserved[0] 903 */ 904 info = (data_len/8) << 24; 905 } 906 if (type == ICMP_TIME_EXCEEDED) 907 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 908 info, &temp_saddr, IP6CB(skb2)); 909 else 910 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 911 info, &temp_saddr, IP6CB(skb2)); 912 if (rt) 913 ip6_rt_put(rt); 914 915 kfree_skb(skb2); 916 917 return 0; 918 } 919 EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach); 920 921 static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) 922 { 923 struct net *net = dev_net_rcu(skb->dev); 924 struct sock *sk; 925 struct inet6_dev *idev; 926 struct ipv6_pinfo *np; 927 const struct in6_addr *saddr = NULL; 928 struct icmp6hdr *icmph = icmp6_hdr(skb); 929 bool apply_ratelimit = false; 930 struct icmp6hdr tmp_hdr; 931 struct flowi6 fl6; 932 struct icmpv6_msg msg; 933 struct dst_entry *dst; 934 struct ipcm6_cookie ipc6; 935 u32 mark = IP6_REPLY_MARK(net, skb->mark); 936 SKB_DR(reason); 937 bool acast; 938 u8 type; 939 940 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) && 941 net->ipv6.sysctl.icmpv6_echo_ignore_multicast) 942 return reason; 943 944 saddr = &ipv6_hdr(skb)->daddr; 945 946 acast = ipv6_anycast_destination(skb_dst(skb), saddr); 947 if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast) 948 return reason; 949 950 if (!ipv6_unicast_destination(skb) && 951 !(net->ipv6.sysctl.anycast_src_echo_reply && acast)) 952 saddr = NULL; 953 954 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST) 955 type = ICMPV6_EXT_ECHO_REPLY; 956 else 957 type = ICMPV6_ECHO_REPLY; 958 959 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); 960 tmp_hdr.icmp6_type = type; 961 962 memset(&fl6, 0, sizeof(fl6)); 963 if (READ_ONCE(net->ipv6.sysctl.flowlabel_reflect) & 964 FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES) 965 fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb)); 966 967 fl6.flowi6_proto = IPPROTO_ICMPV6; 968 fl6.daddr = ipv6_hdr(skb)->saddr; 969 if (saddr) 970 fl6.saddr = *saddr; 971 fl6.flowi6_oif = ipv6_addr_loopback(&fl6.daddr) ? 972 skb->dev->ifindex : 973 icmp6_iif(skb); 974 fl6.fl6_icmp_type = type; 975 fl6.flowi6_mark = mark; 976 fl6.flowi6_uid = sock_net_uid(net, NULL); 977 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6)); 978 979 local_bh_disable(); 980 sk = icmpv6_xmit_lock(net); 981 if (!sk) 982 goto out_bh_enable; 983 np = inet6_sk(sk); 984 985 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 986 fl6.flowi6_oif = READ_ONCE(np->mcast_oif); 987 else if (!fl6.flowi6_oif) 988 fl6.flowi6_oif = READ_ONCE(np->ucast_oif); 989 990 if (ip6_dst_lookup(net, sk, &dst, &fl6)) 991 goto out; 992 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); 993 if (IS_ERR(dst)) 994 goto out; 995 996 /* Check the ratelimit */ 997 if ((!(skb->dev->flags & IFF_LOOPBACK) && 998 !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY, &apply_ratelimit)) || 999 !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6, apply_ratelimit)) 1000 goto out_dst_release; 1001 1002 idev = __in6_dev_get(skb->dev); 1003 1004 msg.skb = skb; 1005 msg.offset = 0; 1006 msg.type = type; 1007 1008 ipcm6_init_sk(&ipc6, sk); 1009 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 1010 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb)); 1011 ipc6.sockc.mark = mark; 1012 1013 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST) 1014 if (!icmp_build_probe(skb, (struct icmphdr *)&tmp_hdr)) 1015 goto out_dst_release; 1016 1017 if (ip6_append_data(sk, icmpv6_getfrag, &msg, 1018 skb->len + sizeof(struct icmp6hdr), 1019 sizeof(struct icmp6hdr), &ipc6, &fl6, 1020 dst_rt6_info(dst), MSG_DONTWAIT)) { 1021 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS); 1022 ip6_flush_pending_frames(sk); 1023 } else { 1024 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, 1025 skb->len + sizeof(struct icmp6hdr)); 1026 reason = SKB_CONSUMED; 1027 } 1028 out_dst_release: 1029 dst_release(dst); 1030 out: 1031 icmpv6_xmit_unlock(sk); 1032 out_bh_enable: 1033 local_bh_enable(); 1034 return reason; 1035 } 1036 1037 enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type, 1038 u8 code, __be32 info) 1039 { 1040 struct inet6_skb_parm *opt = IP6CB(skb); 1041 struct net *net = dev_net_rcu(skb->dev); 1042 const struct inet6_protocol *ipprot; 1043 enum skb_drop_reason reason; 1044 int inner_offset; 1045 __be16 frag_off; 1046 u8 nexthdr; 1047 1048 reason = pskb_may_pull_reason(skb, sizeof(struct ipv6hdr)); 1049 if (reason != SKB_NOT_DROPPED_YET) 1050 goto out; 1051 1052 seg6_icmp_srh(skb, opt); 1053 1054 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; 1055 if (ipv6_ext_hdr(nexthdr)) { 1056 /* now skip over extension headers */ 1057 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), 1058 &nexthdr, &frag_off); 1059 if (inner_offset < 0) { 1060 SKB_DR_SET(reason, IPV6_BAD_EXTHDR); 1061 goto out; 1062 } 1063 } else { 1064 inner_offset = sizeof(struct ipv6hdr); 1065 } 1066 1067 /* Checkin header including 8 bytes of inner protocol header. */ 1068 reason = pskb_may_pull_reason(skb, inner_offset + 8); 1069 if (reason != SKB_NOT_DROPPED_YET) 1070 goto out; 1071 1072 if (nexthdr == IPPROTO_RAW) { 1073 /* Add a more specific reason later ? */ 1074 reason = SKB_DROP_REASON_NOT_SPECIFIED; 1075 goto out; 1076 } 1077 1078 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. 1079 Without this we will not able f.e. to make source routed 1080 pmtu discovery. 1081 Corresponding argument (opt) to notifiers is already added. 1082 --ANK (980726) 1083 */ 1084 1085 ipprot = rcu_dereference(inet6_protos[nexthdr]); 1086 if (ipprot && ipprot->err_handler) 1087 ipprot->err_handler(skb, opt, type, code, inner_offset, info); 1088 1089 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); 1090 return SKB_CONSUMED; 1091 1092 out: 1093 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); 1094 return reason; 1095 } 1096 1097 /* 1098 * Handle icmp messages 1099 */ 1100 1101 static int icmpv6_rcv(struct sk_buff *skb) 1102 { 1103 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 1104 struct net *net = dev_net_rcu(skb->dev); 1105 struct net_device *dev = icmp6_dev(skb); 1106 struct inet6_dev *idev = __in6_dev_get(dev); 1107 const struct in6_addr *saddr, *daddr; 1108 struct icmp6hdr *hdr; 1109 u8 type; 1110 1111 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 1112 struct sec_path *sp = skb_sec_path(skb); 1113 int nh; 1114 1115 if (!(sp && sp->xvec[sp->len - 1]->props.flags & 1116 XFRM_STATE_ICMP)) { 1117 reason = SKB_DROP_REASON_XFRM_POLICY; 1118 goto drop_no_count; 1119 } 1120 1121 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr))) 1122 goto drop_no_count; 1123 1124 nh = skb_network_offset(skb); 1125 skb_set_network_header(skb, sizeof(*hdr)); 1126 1127 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, 1128 skb)) { 1129 reason = SKB_DROP_REASON_XFRM_POLICY; 1130 goto drop_no_count; 1131 } 1132 1133 skb_set_network_header(skb, nh); 1134 } 1135 1136 __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_INMSGS); 1137 1138 saddr = &ipv6_hdr(skb)->saddr; 1139 daddr = &ipv6_hdr(skb)->daddr; 1140 1141 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) { 1142 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n", 1143 saddr, daddr); 1144 goto csum_error; 1145 } 1146 1147 if (!pskb_pull(skb, sizeof(*hdr))) 1148 goto discard_it; 1149 1150 hdr = icmp6_hdr(skb); 1151 1152 type = hdr->icmp6_type; 1153 1154 ICMP6MSGIN_INC_STATS(dev_net_rcu(dev), idev, type); 1155 1156 switch (type) { 1157 case ICMPV6_ECHO_REQUEST: 1158 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all) 1159 reason = icmpv6_echo_reply(skb); 1160 break; 1161 case ICMPV6_EXT_ECHO_REQUEST: 1162 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all && 1163 READ_ONCE(net->ipv4.sysctl_icmp_echo_enable_probe)) 1164 reason = icmpv6_echo_reply(skb); 1165 break; 1166 1167 case ICMPV6_ECHO_REPLY: 1168 case ICMPV6_EXT_ECHO_REPLY: 1169 ping_rcv(skb); 1170 return 0; 1171 1172 case ICMPV6_PKT_TOOBIG: 1173 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update 1174 standard destination cache. Seems, only "advanced" 1175 destination cache will allow to solve this problem 1176 --ANK (980726) 1177 */ 1178 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 1179 goto discard_it; 1180 hdr = icmp6_hdr(skb); 1181 1182 /* to notify */ 1183 fallthrough; 1184 case ICMPV6_DEST_UNREACH: 1185 case ICMPV6_TIME_EXCEED: 1186 case ICMPV6_PARAMPROB: 1187 reason = icmpv6_notify(skb, type, hdr->icmp6_code, 1188 hdr->icmp6_mtu); 1189 break; 1190 1191 case NDISC_ROUTER_SOLICITATION: 1192 case NDISC_ROUTER_ADVERTISEMENT: 1193 case NDISC_NEIGHBOUR_SOLICITATION: 1194 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1195 case NDISC_REDIRECT: 1196 reason = ndisc_rcv(skb); 1197 break; 1198 1199 case ICMPV6_MGM_QUERY: 1200 igmp6_event_query(skb); 1201 return 0; 1202 1203 case ICMPV6_MGM_REPORT: 1204 igmp6_event_report(skb); 1205 return 0; 1206 1207 case ICMPV6_MGM_REDUCTION: 1208 case ICMPV6_NI_QUERY: 1209 case ICMPV6_NI_REPLY: 1210 case ICMPV6_MLD2_REPORT: 1211 case ICMPV6_DHAAD_REQUEST: 1212 case ICMPV6_DHAAD_REPLY: 1213 case ICMPV6_MOBILE_PREFIX_SOL: 1214 case ICMPV6_MOBILE_PREFIX_ADV: 1215 break; 1216 1217 default: 1218 /* informational */ 1219 if (type & ICMPV6_INFOMSG_MASK) 1220 break; 1221 1222 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n", 1223 saddr, daddr); 1224 1225 /* 1226 * error of unknown type. 1227 * must pass to upper level 1228 */ 1229 1230 reason = icmpv6_notify(skb, type, hdr->icmp6_code, 1231 hdr->icmp6_mtu); 1232 } 1233 1234 /* until the v6 path can be better sorted assume failure and 1235 * preserve the status quo behaviour for the rest of the paths to here 1236 */ 1237 if (reason) 1238 kfree_skb_reason(skb, reason); 1239 else 1240 consume_skb(skb); 1241 1242 return 0; 1243 1244 csum_error: 1245 reason = SKB_DROP_REASON_ICMP_CSUM; 1246 __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_CSUMERRORS); 1247 discard_it: 1248 __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_INERRORS); 1249 drop_no_count: 1250 kfree_skb_reason(skb, reason); 1251 return 0; 1252 } 1253 1254 void icmpv6_flow_init(const struct sock *sk, struct flowi6 *fl6, u8 type, 1255 const struct in6_addr *saddr, 1256 const struct in6_addr *daddr, int oif) 1257 { 1258 memset(fl6, 0, sizeof(*fl6)); 1259 fl6->saddr = *saddr; 1260 fl6->daddr = *daddr; 1261 fl6->flowi6_proto = IPPROTO_ICMPV6; 1262 fl6->fl6_icmp_type = type; 1263 fl6->fl6_icmp_code = 0; 1264 fl6->flowi6_oif = oif; 1265 security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6)); 1266 } 1267 1268 int __init icmpv6_init(void) 1269 { 1270 struct sock *sk; 1271 int err, i; 1272 1273 for_each_possible_cpu(i) { 1274 err = inet_ctl_sock_create(&sk, PF_INET6, 1275 SOCK_RAW, IPPROTO_ICMPV6, &init_net); 1276 if (err < 0) { 1277 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n", 1278 err); 1279 return err; 1280 } 1281 1282 per_cpu(ipv6_icmp_sk, i) = sk; 1283 1284 /* Enough space for 2 64K ICMP packets, including 1285 * sk_buff struct overhead. 1286 */ 1287 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); 1288 } 1289 1290 err = -EAGAIN; 1291 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) 1292 goto fail; 1293 1294 err = inet6_register_icmp_sender(icmp6_send); 1295 if (err) 1296 goto sender_reg_err; 1297 return 0; 1298 1299 sender_reg_err: 1300 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); 1301 fail: 1302 pr_err("Failed to register ICMP6 protocol\n"); 1303 return err; 1304 } 1305 1306 void icmpv6_cleanup(void) 1307 { 1308 inet6_unregister_icmp_sender(icmp6_send); 1309 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); 1310 } 1311 1312 1313 static const struct icmp6_err { 1314 int err; 1315 int fatal; 1316 } tab_unreach[] = { 1317 { /* NOROUTE */ 1318 .err = ENETUNREACH, 1319 .fatal = 0, 1320 }, 1321 { /* ADM_PROHIBITED */ 1322 .err = EACCES, 1323 .fatal = 1, 1324 }, 1325 { /* Was NOT_NEIGHBOUR, now reserved */ 1326 .err = EHOSTUNREACH, 1327 .fatal = 0, 1328 }, 1329 { /* ADDR_UNREACH */ 1330 .err = EHOSTUNREACH, 1331 .fatal = 0, 1332 }, 1333 { /* PORT_UNREACH */ 1334 .err = ECONNREFUSED, 1335 .fatal = 1, 1336 }, 1337 { /* POLICY_FAIL */ 1338 .err = EACCES, 1339 .fatal = 1, 1340 }, 1341 { /* REJECT_ROUTE */ 1342 .err = EACCES, 1343 .fatal = 1, 1344 }, 1345 }; 1346 1347 int icmpv6_err_convert(u8 type, u8 code, int *err) 1348 { 1349 int fatal = 0; 1350 1351 *err = EPROTO; 1352 1353 switch (type) { 1354 case ICMPV6_DEST_UNREACH: 1355 fatal = 1; 1356 if (code < ARRAY_SIZE(tab_unreach)) { 1357 *err = tab_unreach[code].err; 1358 fatal = tab_unreach[code].fatal; 1359 } 1360 break; 1361 1362 case ICMPV6_PKT_TOOBIG: 1363 *err = EMSGSIZE; 1364 break; 1365 1366 case ICMPV6_PARAMPROB: 1367 *err = EPROTO; 1368 fatal = 1; 1369 break; 1370 1371 case ICMPV6_TIME_EXCEED: 1372 *err = EHOSTUNREACH; 1373 break; 1374 } 1375 1376 return fatal; 1377 } 1378 EXPORT_SYMBOL(icmpv6_err_convert); 1379 1380 #ifdef CONFIG_SYSCTL 1381 1382 static u32 icmpv6_errors_extension_mask_all = 1383 GENMASK_U8(ICMP_ERR_EXT_COUNT - 1, 0); 1384 1385 static struct ctl_table ipv6_icmp_table_template[] = { 1386 { 1387 .procname = "ratelimit", 1388 .data = &init_net.ipv6.sysctl.icmpv6_time, 1389 .maxlen = sizeof(int), 1390 .mode = 0644, 1391 .proc_handler = proc_dointvec_ms_jiffies, 1392 }, 1393 { 1394 .procname = "echo_ignore_all", 1395 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all, 1396 .maxlen = sizeof(u8), 1397 .mode = 0644, 1398 .proc_handler = proc_dou8vec_minmax, 1399 }, 1400 { 1401 .procname = "echo_ignore_multicast", 1402 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast, 1403 .maxlen = sizeof(u8), 1404 .mode = 0644, 1405 .proc_handler = proc_dou8vec_minmax, 1406 }, 1407 { 1408 .procname = "echo_ignore_anycast", 1409 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast, 1410 .maxlen = sizeof(u8), 1411 .mode = 0644, 1412 .proc_handler = proc_dou8vec_minmax, 1413 }, 1414 { 1415 .procname = "ratemask", 1416 .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr, 1417 .maxlen = ICMPV6_MSG_MAX + 1, 1418 .mode = 0644, 1419 .proc_handler = proc_do_large_bitmap, 1420 }, 1421 { 1422 .procname = "error_anycast_as_unicast", 1423 .data = &init_net.ipv6.sysctl.icmpv6_error_anycast_as_unicast, 1424 .maxlen = sizeof(u8), 1425 .mode = 0644, 1426 .proc_handler = proc_dou8vec_minmax, 1427 .extra1 = SYSCTL_ZERO, 1428 .extra2 = SYSCTL_ONE, 1429 }, 1430 { 1431 .procname = "errors_extension_mask", 1432 .data = &init_net.ipv6.sysctl.icmpv6_errors_extension_mask, 1433 .maxlen = sizeof(u8), 1434 .mode = 0644, 1435 .proc_handler = proc_dou8vec_minmax, 1436 .extra1 = SYSCTL_ZERO, 1437 .extra2 = &icmpv6_errors_extension_mask_all, 1438 }, 1439 }; 1440 1441 struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) 1442 { 1443 struct ctl_table *table; 1444 1445 table = kmemdup(ipv6_icmp_table_template, 1446 sizeof(ipv6_icmp_table_template), 1447 GFP_KERNEL); 1448 1449 if (table) { 1450 table[0].data = &net->ipv6.sysctl.icmpv6_time; 1451 table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all; 1452 table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast; 1453 table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast; 1454 table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr; 1455 table[5].data = &net->ipv6.sysctl.icmpv6_error_anycast_as_unicast; 1456 table[6].data = &net->ipv6.sysctl.icmpv6_errors_extension_mask; 1457 } 1458 return table; 1459 } 1460 1461 size_t ipv6_icmp_sysctl_table_size(void) 1462 { 1463 return ARRAY_SIZE(ipv6_icmp_table_template); 1464 } 1465 #endif 1466