1 /* 2 * Internet Control Message Protocol (ICMPv6) 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * $Id: icmp.c,v 1.38 2002/02/08 03:57:19 davem Exp $ 9 * 10 * Based on net/ipv4/icmp.c 11 * 12 * RFC 1885 13 * 14 * This program is free software; you can redistribute it and/or 15 * modify it under the terms of the GNU General Public License 16 * as published by the Free Software Foundation; either version 17 * 2 of the License, or (at your option) any later version. 18 */ 19 20 /* 21 * Changes: 22 * 23 * Andi Kleen : exception handling 24 * Andi Kleen add rate limits. never reply to a icmp. 25 * add more length checks and other fixes. 26 * yoshfuji : ensure to sent parameter problem for 27 * fragments. 28 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit. 29 * Randy Dunlap and 30 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support 31 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data 32 */ 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/sched.h> 41 #include <linux/sockios.h> 42 #include <linux/net.h> 43 #include <linux/skbuff.h> 44 #include <linux/init.h> 45 #include <linux/netfilter.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/protocol.h> 61 #include <net/raw.h> 62 #include <net/rawv6.h> 63 #include <net/transp_v6.h> 64 #include <net/ip6_route.h> 65 #include <net/addrconf.h> 66 #include <net/icmp.h> 67 68 #include <asm/uaccess.h> 69 #include <asm/system.h> 70 71 DEFINE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics) __read_mostly; 72 73 /* 74 * The ICMP socket(s). This is the most convenient way to flow control 75 * our ICMP output as well as maintain a clean interface throughout 76 * all layers. All Socketless IP sends will soon be gone. 77 * 78 * On SMP we have one ICMP socket per-cpu. 79 */ 80 static DEFINE_PER_CPU(struct socket *, __icmpv6_socket) = NULL; 81 #define icmpv6_socket __get_cpu_var(__icmpv6_socket) 82 83 static int icmpv6_rcv(struct sk_buff **pskb); 84 85 static struct inet6_protocol icmpv6_protocol = { 86 .handler = icmpv6_rcv, 87 .flags = INET6_PROTO_FINAL, 88 }; 89 90 static __inline__ int icmpv6_xmit_lock(void) 91 { 92 local_bh_disable(); 93 94 if (unlikely(!spin_trylock(&icmpv6_socket->sk->sk_lock.slock))) { 95 /* This can happen if the output path (f.e. SIT or 96 * ip6ip6 tunnel) signals dst_link_failure() for an 97 * outgoing ICMP6 packet. 98 */ 99 local_bh_enable(); 100 return 1; 101 } 102 return 0; 103 } 104 105 static __inline__ void icmpv6_xmit_unlock(void) 106 { 107 spin_unlock_bh(&icmpv6_socket->sk->sk_lock.slock); 108 } 109 110 /* 111 * Slightly more convenient version of icmpv6_send. 112 */ 113 void icmpv6_param_prob(struct sk_buff *skb, int code, int pos) 114 { 115 icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev); 116 kfree_skb(skb); 117 } 118 119 /* 120 * Figure out, may we reply to this packet with icmp error. 121 * 122 * We do not reply, if: 123 * - it was icmp error message. 124 * - it is truncated, so that it is known, that protocol is ICMPV6 125 * (i.e. in the middle of some exthdr) 126 * 127 * --ANK (980726) 128 */ 129 130 static int is_ineligible(struct sk_buff *skb) 131 { 132 int ptr = (u8*)(skb->nh.ipv6h+1) - skb->data; 133 int len = skb->len - ptr; 134 __u8 nexthdr = skb->nh.ipv6h->nexthdr; 135 136 if (len < 0) 137 return 1; 138 139 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr); 140 if (ptr < 0) 141 return 0; 142 if (nexthdr == IPPROTO_ICMPV6) { 143 u8 _type, *tp; 144 tp = skb_header_pointer(skb, 145 ptr+offsetof(struct icmp6hdr, icmp6_type), 146 sizeof(_type), &_type); 147 if (tp == NULL || 148 !(*tp & ICMPV6_INFOMSG_MASK)) 149 return 1; 150 } 151 return 0; 152 } 153 154 static int sysctl_icmpv6_time __read_mostly = 1*HZ; 155 156 /* 157 * Check the ICMP output rate limit 158 */ 159 static inline int icmpv6_xrlim_allow(struct sock *sk, int type, 160 struct flowi *fl) 161 { 162 struct dst_entry *dst; 163 int res = 0; 164 165 /* Informational messages are not limited. */ 166 if (type & ICMPV6_INFOMSG_MASK) 167 return 1; 168 169 /* Do not limit pmtu discovery, it would break it. */ 170 if (type == ICMPV6_PKT_TOOBIG) 171 return 1; 172 173 /* 174 * Look up the output route. 175 * XXX: perhaps the expire for routing entries cloned by 176 * this lookup should be more aggressive (not longer than timeout). 177 */ 178 dst = ip6_route_output(sk, fl); 179 if (dst->error) { 180 IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES); 181 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { 182 res = 1; 183 } else { 184 struct rt6_info *rt = (struct rt6_info *)dst; 185 int tmo = sysctl_icmpv6_time; 186 187 /* Give more bandwidth to wider prefixes. */ 188 if (rt->rt6i_dst.plen < 128) 189 tmo >>= ((128 - rt->rt6i_dst.plen)>>5); 190 191 res = xrlim_allow(dst, tmo); 192 } 193 dst_release(dst); 194 return res; 195 } 196 197 /* 198 * an inline helper for the "simple" if statement below 199 * checks if parameter problem report is caused by an 200 * unrecognized IPv6 option that has the Option Type 201 * highest-order two bits set to 10 202 */ 203 204 static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset) 205 { 206 u8 _optval, *op; 207 208 offset += skb->nh.raw - skb->data; 209 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); 210 if (op == NULL) 211 return 1; 212 return (*op & 0xC0) == 0x80; 213 } 214 215 static int icmpv6_push_pending_frames(struct sock *sk, struct flowi *fl, struct icmp6hdr *thdr, int len) 216 { 217 struct sk_buff *skb; 218 struct icmp6hdr *icmp6h; 219 int err = 0; 220 221 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) 222 goto out; 223 224 icmp6h = (struct icmp6hdr*) skb->h.raw; 225 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); 226 icmp6h->icmp6_cksum = 0; 227 228 if (skb_queue_len(&sk->sk_write_queue) == 1) { 229 skb->csum = csum_partial((char *)icmp6h, 230 sizeof(struct icmp6hdr), skb->csum); 231 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src, 232 &fl->fl6_dst, 233 len, fl->proto, 234 skb->csum); 235 } else { 236 u32 tmp_csum = 0; 237 238 skb_queue_walk(&sk->sk_write_queue, skb) { 239 tmp_csum = csum_add(tmp_csum, skb->csum); 240 } 241 242 tmp_csum = csum_partial((char *)icmp6h, 243 sizeof(struct icmp6hdr), tmp_csum); 244 tmp_csum = csum_ipv6_magic(&fl->fl6_src, 245 &fl->fl6_dst, 246 len, fl->proto, tmp_csum); 247 icmp6h->icmp6_cksum = tmp_csum; 248 } 249 if (icmp6h->icmp6_cksum == 0) 250 icmp6h->icmp6_cksum = -1; 251 ip6_push_pending_frames(sk); 252 out: 253 return err; 254 } 255 256 struct icmpv6_msg { 257 struct sk_buff *skb; 258 int offset; 259 uint8_t type; 260 }; 261 262 static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) 263 { 264 struct icmpv6_msg *msg = (struct icmpv6_msg *) from; 265 struct sk_buff *org_skb = msg->skb; 266 __u32 csum = 0; 267 268 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, 269 to, len, csum); 270 skb->csum = csum_block_add(skb->csum, csum, odd); 271 if (!(msg->type & ICMPV6_INFOMSG_MASK)) 272 nf_ct_attach(skb, org_skb); 273 return 0; 274 } 275 276 /* 277 * Send an ICMP message in response to a packet in error 278 */ 279 void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info, 280 struct net_device *dev) 281 { 282 struct inet6_dev *idev = NULL; 283 struct ipv6hdr *hdr = skb->nh.ipv6h; 284 struct sock *sk; 285 struct ipv6_pinfo *np; 286 struct in6_addr *saddr = NULL; 287 struct dst_entry *dst; 288 struct icmp6hdr tmp_hdr; 289 struct flowi fl; 290 struct icmpv6_msg msg; 291 int iif = 0; 292 int addr_type = 0; 293 int len; 294 int hlimit, tclass; 295 int err = 0; 296 297 if ((u8*)hdr < skb->head || (u8*)(hdr+1) > skb->tail) 298 return; 299 300 /* 301 * Make sure we respect the rules 302 * i.e. RFC 1885 2.4(e) 303 * Rule (e.1) is enforced by not using icmpv6_send 304 * in any code that processes icmp errors. 305 */ 306 addr_type = ipv6_addr_type(&hdr->daddr); 307 308 if (ipv6_chk_addr(&hdr->daddr, skb->dev, 0)) 309 saddr = &hdr->daddr; 310 311 /* 312 * Dest addr check 313 */ 314 315 if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { 316 if (type != ICMPV6_PKT_TOOBIG && 317 !(type == ICMPV6_PARAMPROB && 318 code == ICMPV6_UNK_OPTION && 319 (opt_unrec(skb, info)))) 320 return; 321 322 saddr = NULL; 323 } 324 325 addr_type = ipv6_addr_type(&hdr->saddr); 326 327 /* 328 * Source addr check 329 */ 330 331 if (addr_type & IPV6_ADDR_LINKLOCAL) 332 iif = skb->dev->ifindex; 333 334 /* 335 * Must not send error if the source does not uniquely 336 * identify a single node (RFC2463 Section 2.4). 337 * We check unspecified / multicast addresses here, 338 * and anycast addresses will be checked later. 339 */ 340 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { 341 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n"); 342 return; 343 } 344 345 /* 346 * Never answer to a ICMP packet. 347 */ 348 if (is_ineligible(skb)) { 349 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n"); 350 return; 351 } 352 353 memset(&fl, 0, sizeof(fl)); 354 fl.proto = IPPROTO_ICMPV6; 355 ipv6_addr_copy(&fl.fl6_dst, &hdr->saddr); 356 if (saddr) 357 ipv6_addr_copy(&fl.fl6_src, saddr); 358 fl.oif = iif; 359 fl.fl_icmp_type = type; 360 fl.fl_icmp_code = code; 361 security_skb_classify_flow(skb, &fl); 362 363 if (icmpv6_xmit_lock()) 364 return; 365 366 sk = icmpv6_socket->sk; 367 np = inet6_sk(sk); 368 369 if (!icmpv6_xrlim_allow(sk, type, &fl)) 370 goto out; 371 372 tmp_hdr.icmp6_type = type; 373 tmp_hdr.icmp6_code = code; 374 tmp_hdr.icmp6_cksum = 0; 375 tmp_hdr.icmp6_pointer = htonl(info); 376 377 if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) 378 fl.oif = np->mcast_oif; 379 380 err = ip6_dst_lookup(sk, &dst, &fl); 381 if (err) 382 goto out; 383 384 /* 385 * We won't send icmp if the destination is known 386 * anycast. 387 */ 388 if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { 389 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n"); 390 goto out_dst_release; 391 } 392 393 if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) 394 goto out; 395 396 if (ipv6_addr_is_multicast(&fl.fl6_dst)) 397 hlimit = np->mcast_hops; 398 else 399 hlimit = np->hop_limit; 400 if (hlimit < 0) 401 hlimit = dst_metric(dst, RTAX_HOPLIMIT); 402 if (hlimit < 0) 403 hlimit = ipv6_get_hoplimit(dst->dev); 404 405 tclass = np->tclass; 406 if (tclass < 0) 407 tclass = 0; 408 409 msg.skb = skb; 410 msg.offset = skb->nh.raw - skb->data; 411 msg.type = type; 412 413 len = skb->len - msg.offset; 414 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); 415 if (len < 0) { 416 LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); 417 goto out_dst_release; 418 } 419 420 idev = in6_dev_get(skb->dev); 421 422 err = ip6_append_data(sk, icmpv6_getfrag, &msg, 423 len + sizeof(struct icmp6hdr), 424 sizeof(struct icmp6hdr), 425 hlimit, tclass, NULL, &fl, (struct rt6_info*)dst, 426 MSG_DONTWAIT); 427 if (err) { 428 ip6_flush_pending_frames(sk); 429 goto out_put; 430 } 431 err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr)); 432 433 if (type >= ICMPV6_DEST_UNREACH && type <= ICMPV6_PARAMPROB) 434 ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_OUTDESTUNREACHS, type - ICMPV6_DEST_UNREACH); 435 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS); 436 437 out_put: 438 if (likely(idev != NULL)) 439 in6_dev_put(idev); 440 out_dst_release: 441 dst_release(dst); 442 out: 443 icmpv6_xmit_unlock(); 444 } 445 446 static void icmpv6_echo_reply(struct sk_buff *skb) 447 { 448 struct sock *sk; 449 struct inet6_dev *idev; 450 struct ipv6_pinfo *np; 451 struct in6_addr *saddr = NULL; 452 struct icmp6hdr *icmph = (struct icmp6hdr *) skb->h.raw; 453 struct icmp6hdr tmp_hdr; 454 struct flowi fl; 455 struct icmpv6_msg msg; 456 struct dst_entry *dst; 457 int err = 0; 458 int hlimit; 459 int tclass; 460 461 saddr = &skb->nh.ipv6h->daddr; 462 463 if (!ipv6_unicast_destination(skb)) 464 saddr = NULL; 465 466 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); 467 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; 468 469 memset(&fl, 0, sizeof(fl)); 470 fl.proto = IPPROTO_ICMPV6; 471 ipv6_addr_copy(&fl.fl6_dst, &skb->nh.ipv6h->saddr); 472 if (saddr) 473 ipv6_addr_copy(&fl.fl6_src, saddr); 474 fl.oif = skb->dev->ifindex; 475 fl.fl_icmp_type = ICMPV6_ECHO_REPLY; 476 security_skb_classify_flow(skb, &fl); 477 478 if (icmpv6_xmit_lock()) 479 return; 480 481 sk = icmpv6_socket->sk; 482 np = inet6_sk(sk); 483 484 if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) 485 fl.oif = np->mcast_oif; 486 487 err = ip6_dst_lookup(sk, &dst, &fl); 488 if (err) 489 goto out; 490 if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) 491 goto out; 492 493 if (ipv6_addr_is_multicast(&fl.fl6_dst)) 494 hlimit = np->mcast_hops; 495 else 496 hlimit = np->hop_limit; 497 if (hlimit < 0) 498 hlimit = dst_metric(dst, RTAX_HOPLIMIT); 499 if (hlimit < 0) 500 hlimit = ipv6_get_hoplimit(dst->dev); 501 502 tclass = np->tclass; 503 if (tclass < 0) 504 tclass = 0; 505 506 idev = in6_dev_get(skb->dev); 507 508 msg.skb = skb; 509 msg.offset = 0; 510 msg.type = ICMPV6_ECHO_REPLY; 511 512 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), 513 sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl, 514 (struct rt6_info*)dst, MSG_DONTWAIT); 515 516 if (err) { 517 ip6_flush_pending_frames(sk); 518 goto out_put; 519 } 520 err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, skb->len + sizeof(struct icmp6hdr)); 521 522 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTECHOREPLIES); 523 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS); 524 525 out_put: 526 if (likely(idev != NULL)) 527 in6_dev_put(idev); 528 dst_release(dst); 529 out: 530 icmpv6_xmit_unlock(); 531 } 532 533 static void icmpv6_notify(struct sk_buff *skb, int type, int code, u32 info) 534 { 535 struct in6_addr *saddr, *daddr; 536 struct inet6_protocol *ipprot; 537 struct sock *sk; 538 int inner_offset; 539 int hash; 540 u8 nexthdr; 541 542 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 543 return; 544 545 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; 546 if (ipv6_ext_hdr(nexthdr)) { 547 /* now skip over extension headers */ 548 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); 549 if (inner_offset<0) 550 return; 551 } else { 552 inner_offset = sizeof(struct ipv6hdr); 553 } 554 555 /* Checkin header including 8 bytes of inner protocol header. */ 556 if (!pskb_may_pull(skb, inner_offset+8)) 557 return; 558 559 saddr = &skb->nh.ipv6h->saddr; 560 daddr = &skb->nh.ipv6h->daddr; 561 562 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. 563 Without this we will not able f.e. to make source routed 564 pmtu discovery. 565 Corresponding argument (opt) to notifiers is already added. 566 --ANK (980726) 567 */ 568 569 hash = nexthdr & (MAX_INET_PROTOS - 1); 570 571 rcu_read_lock(); 572 ipprot = rcu_dereference(inet6_protos[hash]); 573 if (ipprot && ipprot->err_handler) 574 ipprot->err_handler(skb, NULL, type, code, inner_offset, info); 575 rcu_read_unlock(); 576 577 read_lock(&raw_v6_lock); 578 if ((sk = sk_head(&raw_v6_htable[hash])) != NULL) { 579 while((sk = __raw_v6_lookup(sk, nexthdr, daddr, saddr, 580 IP6CB(skb)->iif))) { 581 rawv6_err(sk, skb, NULL, type, code, inner_offset, info); 582 sk = sk_next(sk); 583 } 584 } 585 read_unlock(&raw_v6_lock); 586 } 587 588 /* 589 * Handle icmp messages 590 */ 591 592 static int icmpv6_rcv(struct sk_buff **pskb) 593 { 594 struct sk_buff *skb = *pskb; 595 struct net_device *dev = skb->dev; 596 struct inet6_dev *idev = __in6_dev_get(dev); 597 struct in6_addr *saddr, *daddr; 598 struct ipv6hdr *orig_hdr; 599 struct icmp6hdr *hdr; 600 int type; 601 602 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INMSGS); 603 604 saddr = &skb->nh.ipv6h->saddr; 605 daddr = &skb->nh.ipv6h->daddr; 606 607 /* Perform checksum. */ 608 switch (skb->ip_summed) { 609 case CHECKSUM_COMPLETE: 610 if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, 611 skb->csum)) 612 break; 613 /* fall through */ 614 case CHECKSUM_NONE: 615 skb->csum = ~csum_ipv6_magic(saddr, daddr, skb->len, 616 IPPROTO_ICMPV6, 0); 617 if (__skb_checksum_complete(skb)) { 618 LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [" NIP6_FMT " > " NIP6_FMT "]\n", 619 NIP6(*saddr), NIP6(*daddr)); 620 goto discard_it; 621 } 622 } 623 624 if (!pskb_pull(skb, sizeof(struct icmp6hdr))) 625 goto discard_it; 626 627 hdr = (struct icmp6hdr *) skb->h.raw; 628 629 type = hdr->icmp6_type; 630 631 if (type >= ICMPV6_DEST_UNREACH && type <= ICMPV6_PARAMPROB) 632 ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_INDESTUNREACHS, type - ICMPV6_DEST_UNREACH); 633 else if (type >= ICMPV6_ECHO_REQUEST && type <= NDISC_REDIRECT) 634 ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_INECHOS, type - ICMPV6_ECHO_REQUEST); 635 636 switch (type) { 637 case ICMPV6_ECHO_REQUEST: 638 icmpv6_echo_reply(skb); 639 break; 640 641 case ICMPV6_ECHO_REPLY: 642 /* we couldn't care less */ 643 break; 644 645 case ICMPV6_PKT_TOOBIG: 646 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update 647 standard destination cache. Seems, only "advanced" 648 destination cache will allow to solve this problem 649 --ANK (980726) 650 */ 651 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 652 goto discard_it; 653 hdr = (struct icmp6hdr *) skb->h.raw; 654 orig_hdr = (struct ipv6hdr *) (hdr + 1); 655 rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, 656 ntohl(hdr->icmp6_mtu)); 657 658 /* 659 * Drop through to notify 660 */ 661 662 case ICMPV6_DEST_UNREACH: 663 case ICMPV6_TIME_EXCEED: 664 case ICMPV6_PARAMPROB: 665 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); 666 break; 667 668 case NDISC_ROUTER_SOLICITATION: 669 case NDISC_ROUTER_ADVERTISEMENT: 670 case NDISC_NEIGHBOUR_SOLICITATION: 671 case NDISC_NEIGHBOUR_ADVERTISEMENT: 672 case NDISC_REDIRECT: 673 ndisc_rcv(skb); 674 break; 675 676 case ICMPV6_MGM_QUERY: 677 igmp6_event_query(skb); 678 break; 679 680 case ICMPV6_MGM_REPORT: 681 igmp6_event_report(skb); 682 break; 683 684 case ICMPV6_MGM_REDUCTION: 685 case ICMPV6_NI_QUERY: 686 case ICMPV6_NI_REPLY: 687 case ICMPV6_MLD2_REPORT: 688 case ICMPV6_DHAAD_REQUEST: 689 case ICMPV6_DHAAD_REPLY: 690 case ICMPV6_MOBILE_PREFIX_SOL: 691 case ICMPV6_MOBILE_PREFIX_ADV: 692 break; 693 694 default: 695 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); 696 697 /* informational */ 698 if (type & ICMPV6_INFOMSG_MASK) 699 break; 700 701 /* 702 * error of unknown type. 703 * must pass to upper level 704 */ 705 706 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); 707 }; 708 kfree_skb(skb); 709 return 0; 710 711 discard_it: 712 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS); 713 kfree_skb(skb); 714 return 0; 715 } 716 717 /* 718 * Special lock-class for __icmpv6_socket: 719 */ 720 static struct lock_class_key icmpv6_socket_sk_dst_lock_key; 721 722 int __init icmpv6_init(struct net_proto_family *ops) 723 { 724 struct sock *sk; 725 int err, i, j; 726 727 for_each_possible_cpu(i) { 728 err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, 729 &per_cpu(__icmpv6_socket, i)); 730 if (err < 0) { 731 printk(KERN_ERR 732 "Failed to initialize the ICMP6 control socket " 733 "(err %d).\n", 734 err); 735 goto fail; 736 } 737 738 sk = per_cpu(__icmpv6_socket, i)->sk; 739 sk->sk_allocation = GFP_ATOMIC; 740 /* 741 * Split off their lock-class, because sk->sk_dst_lock 742 * gets used from softirqs, which is safe for 743 * __icmpv6_socket (because those never get directly used 744 * via userspace syscalls), but unsafe for normal sockets. 745 */ 746 lockdep_set_class(&sk->sk_dst_lock, 747 &icmpv6_socket_sk_dst_lock_key); 748 749 /* Enough space for 2 64K ICMP packets, including 750 * sk_buff struct overhead. 751 */ 752 sk->sk_sndbuf = 753 (2 * ((64 * 1024) + sizeof(struct sk_buff))); 754 755 sk->sk_prot->unhash(sk); 756 } 757 758 759 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) { 760 printk(KERN_ERR "Failed to register ICMP6 protocol\n"); 761 err = -EAGAIN; 762 goto fail; 763 } 764 765 return 0; 766 767 fail: 768 for (j = 0; j < i; j++) { 769 if (!cpu_possible(j)) 770 continue; 771 sock_release(per_cpu(__icmpv6_socket, j)); 772 } 773 774 return err; 775 } 776 777 void icmpv6_cleanup(void) 778 { 779 int i; 780 781 for_each_possible_cpu(i) { 782 sock_release(per_cpu(__icmpv6_socket, i)); 783 } 784 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); 785 } 786 787 static const struct icmp6_err { 788 int err; 789 int fatal; 790 } tab_unreach[] = { 791 { /* NOROUTE */ 792 .err = ENETUNREACH, 793 .fatal = 0, 794 }, 795 { /* ADM_PROHIBITED */ 796 .err = EACCES, 797 .fatal = 1, 798 }, 799 { /* Was NOT_NEIGHBOUR, now reserved */ 800 .err = EHOSTUNREACH, 801 .fatal = 0, 802 }, 803 { /* ADDR_UNREACH */ 804 .err = EHOSTUNREACH, 805 .fatal = 0, 806 }, 807 { /* PORT_UNREACH */ 808 .err = ECONNREFUSED, 809 .fatal = 1, 810 }, 811 }; 812 813 int icmpv6_err_convert(int type, int code, int *err) 814 { 815 int fatal = 0; 816 817 *err = EPROTO; 818 819 switch (type) { 820 case ICMPV6_DEST_UNREACH: 821 fatal = 1; 822 if (code <= ICMPV6_PORT_UNREACH) { 823 *err = tab_unreach[code].err; 824 fatal = tab_unreach[code].fatal; 825 } 826 break; 827 828 case ICMPV6_PKT_TOOBIG: 829 *err = EMSGSIZE; 830 break; 831 832 case ICMPV6_PARAMPROB: 833 *err = EPROTO; 834 fatal = 1; 835 break; 836 837 case ICMPV6_TIME_EXCEED: 838 *err = EHOSTUNREACH; 839 break; 840 }; 841 842 return fatal; 843 } 844 845 #ifdef CONFIG_SYSCTL 846 ctl_table ipv6_icmp_table[] = { 847 { 848 .ctl_name = NET_IPV6_ICMP_RATELIMIT, 849 .procname = "ratelimit", 850 .data = &sysctl_icmpv6_time, 851 .maxlen = sizeof(int), 852 .mode = 0644, 853 .proc_handler = &proc_dointvec 854 }, 855 { .ctl_name = 0 }, 856 }; 857 #endif 858 859