net/ipv6/icmp.c

   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
  46 #ifdef CONFIG_SYSCTL
  47 #include <linux/sysctl.h>
  48 #endif
  49
  50 #include <linux/inet.h>
  51 #include <linux/netdevice.h>
  52 #include <linux/icmpv6.h>
  53
  54 #include <net/ip.h>
  55 #include <net/sock.h>
  56
  57 #include <net/ipv6.h>
  58 #include <net/ip6_checksum.h>
  59 #include <net/protocol.h>
  60 #include <net/raw.h>
  61 #include <net/rawv6.h>
  62 #include <net/transp_v6.h>
  63 #include <net/ip6_route.h>
  64 #include <net/addrconf.h>
  65 #include <net/icmp.h>
  66
  67 #include <asm/uaccess.h>
  68 #include <asm/system.h>
  69
  70 DEFINE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics) __read_mostly;
  71
  72 /*
  73  *      The ICMP socket(s). This is the most convenient way to flow control
  74  *      our ICMP output as well as maintain a clean interface throughout
  75  *      all layers. All Socketless IP sends will soon be gone.
  76  *
  77  *      On SMP we have one ICMP socket per-cpu.
  78  */
  79 static DEFINE_PER_CPU(struct socket *, __icmpv6_socket) = NULL;
  80 #define icmpv6_socket   __get_cpu_var(__icmpv6_socket)
  81
  82 static int icmpv6_rcv(struct sk_buff **pskb, unsigned int *nhoffp);
  83
  84 static struct inet6_protocol icmpv6_protocol = {
  85         .handler        =       icmpv6_rcv,
  86         .flags          =       INET6_PROTO_FINAL,
  87 };
  88
  89 static __inline__ int icmpv6_xmit_lock(void)
  90 {
  91         local_bh_disable();
  92
  93         if (unlikely(!spin_trylock(&icmpv6_socket->sk->sk_lock.slock))) {
  94                 /* This can happen if the output path (f.e. SIT or
  95                  * ip6ip6 tunnel) signals dst_link_failure() for an
  96                  * outgoing ICMP6 packet.
  97                  */
  98                 local_bh_enable();
  99                 return 1;
 100         }
 101         return 0;
 102 }
 103
 104 static __inline__ void icmpv6_xmit_unlock(void)
 105 {
 106         spin_unlock_bh(&icmpv6_socket->sk->sk_lock.slock);
 107 }
 108
 109 /*
 110  * Slightly more convenient version of icmpv6_send.
 111  */
 112 void icmpv6_param_prob(struct sk_buff *skb, int code, int pos)
 113 {
 114         icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev);
 115         kfree_skb(skb);
 116 }
 117
 118 /*
 119  * Figure out, may we reply to this packet with icmp error.
 120  *
 121  * We do not reply, if:
 122  *      - it was icmp error message.
 123  *      - it is truncated, so that it is known, that protocol is ICMPV6
 124  *        (i.e. in the middle of some exthdr)
 125  *
 126  *      --ANK (980726)
 127  */
 128
 129 static int is_ineligible(struct sk_buff *skb)
 130 {
 131         int ptr = (u8*)(skb->nh.ipv6h+1) - skb->data;
 132         int len = skb->len - ptr;
 133         __u8 nexthdr = skb->nh.ipv6h->nexthdr;
 134
 135         if (len < 0)
 136                 return 1;
 137
 138         ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr);
 139         if (ptr < 0)
 140                 return 0;
 141         if (nexthdr == IPPROTO_ICMPV6) {
 142                 u8 _type, *tp;
 143                 tp = skb_header_pointer(skb,
 144                         ptr+offsetof(struct icmp6hdr, icmp6_type),
 145                         sizeof(_type), &_type);
 146                 if (tp == NULL ||
 147                     !(*tp & ICMPV6_INFOMSG_MASK))
 148                         return 1;
 149         }
 150         return 0;
 151 }
 152
 153 static int sysctl_icmpv6_time = 1*HZ;
 154
 155 /*
 156  * Check the ICMP output rate limit
 157  */
 158 static inline int icmpv6_xrlim_allow(struct sock *sk, int type,
 159                                      struct flowi *fl)
 160 {
 161         struct dst_entry *dst;
 162         int res = 0;
 163
 164         /* Informational messages are not limited. */
 165         if (type & ICMPV6_INFOMSG_MASK)
 166                 return 1;
 167
 168         /* Do not limit pmtu discovery, it would break it. */
 169         if (type == ICMPV6_PKT_TOOBIG)
 170                 return 1;
 171
 172         /*
 173          * Look up the output route.
 174          * XXX: perhaps the expire for routing entries cloned by
 175          * this lookup should be more aggressive (not longer than timeout).
 176          */
 177         dst = ip6_route_output(sk, fl);
 178         if (dst->error) {
 179                 IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES);
 180         } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
 181                 res = 1;
 182         } else {
 183                 struct rt6_info *rt = (struct rt6_info *)dst;
 184                 int tmo = sysctl_icmpv6_time;
 185
 186                 /* Give more bandwidth to wider prefixes. */
 187                 if (rt->rt6i_dst.plen < 128)
 188                         tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
 189
 190                 res = xrlim_allow(dst, tmo);
 191         }
 192         dst_release(dst);
 193         return res;
 194 }
 195
 196 /*
 197  *      an inline helper for the "simple" if statement below
 198  *      checks if parameter problem report is caused by an
 199  *      unrecognized IPv6 option that has the Option Type
 200  *      highest-order two bits set to 10
 201  */
 202
 203 static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset)
 204 {
 205         u8 _optval, *op;
 206
 207         offset += skb->nh.raw - skb->data;
 208         op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
 209         if (op == NULL)
 210                 return 1;
 211         return (*op & 0xC0) == 0x80;
 212 }
 213
 214 static int icmpv6_push_pending_frames(struct sock *sk, struct flowi *fl, struct icmp6hdr *thdr, int len)
 215 {
 216         struct sk_buff *skb;
 217         struct icmp6hdr *icmp6h;
 218         int err = 0;
 219
 220         if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
 221                 goto out;
 222
 223         icmp6h = (struct icmp6hdr*) skb->h.raw;
 224         memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
 225         icmp6h->icmp6_cksum = 0;
 226
 227         if (skb_queue_len(&sk->sk_write_queue) == 1) {
 228                 skb->csum = csum_partial((char *)icmp6h,
 229                                         sizeof(struct icmp6hdr), skb->csum);
 230                 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src,
 231                                                       &fl->fl6_dst,
 232                                                       len, fl->proto,
 233                                                       skb->csum);
 234         } else {
 235                 u32 tmp_csum = 0;
 236
 237                 skb_queue_walk(&sk->sk_write_queue, skb) {
 238                         tmp_csum = csum_add(tmp_csum, skb->csum);
 239                 }
 240
 241                 tmp_csum = csum_partial((char *)icmp6h,
 242                                         sizeof(struct icmp6hdr), tmp_csum);
 243                 tmp_csum = csum_ipv6_magic(&fl->fl6_src,
 244                                            &fl->fl6_dst,
 245                                            len, fl->proto, tmp_csum);
 246                 icmp6h->icmp6_cksum = tmp_csum;
 247         }
 248         if (icmp6h->icmp6_cksum == 0)
 249                 icmp6h->icmp6_cksum = -1;
 250         ip6_push_pending_frames(sk);
 251 out:
 252         return err;
 253 }
 254
 255 struct icmpv6_msg {
 256         struct sk_buff  *skb;
 257         int             offset;
 258 };
 259
 260 static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
 261 {
 262         struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
 263         struct sk_buff *org_skb = msg->skb;
 264         __u32 csum = 0;
 265
 266         csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
 267                                       to, len, csum);
 268         skb->csum = csum_block_add(skb->csum, csum, odd);
 269         return 0;
 270 }
 271
 272 /*
 273  *      Send an ICMP message in response to a packet in error
 274  */
 275 void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info,
 276                  struct net_device *dev)
 277 {
 278         struct inet6_dev *idev = NULL;
 279         struct ipv6hdr *hdr = skb->nh.ipv6h;
 280         struct sock *sk;
 281         struct ipv6_pinfo *np;
 282         struct in6_addr *saddr = NULL;
 283         struct dst_entry *dst;
 284         struct icmp6hdr tmp_hdr;
 285         struct flowi fl;
 286         struct icmpv6_msg msg;
 287         int iif = 0;
 288         int addr_type = 0;
 289         int len;
 290         int hlimit, tclass;
 291         int err = 0;
 292
 293         if ((u8*)hdr < skb->head || (u8*)(hdr+1) > skb->tail)
 294                 return;
 295
 296         /*
 297          *      Make sure we respect the rules
 298          *      i.e. RFC 1885 2.4(e)
 299          *      Rule (e.1) is enforced by not using icmpv6_send
 300          *      in any code that processes icmp errors.
 301          */
 302         addr_type = ipv6_addr_type(&hdr->daddr);
 303
 304         if (ipv6_chk_addr(&hdr->daddr, skb->dev, 0))
 305                 saddr = &hdr->daddr;
 306
 307         /*
 308          *      Dest addr check
 309          */
 310
 311         if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) {
 312                 if (type != ICMPV6_PKT_TOOBIG &&
 313                     !(type == ICMPV6_PARAMPROB &&
 314                       code == ICMPV6_UNK_OPTION &&
 315                       (opt_unrec(skb, info))))
 316                         return;
 317
 318                 saddr = NULL;
 319         }
 320
 321         addr_type = ipv6_addr_type(&hdr->saddr);
 322
 323         /*
 324          *      Source addr check
 325          */
 326
 327         if (addr_type & IPV6_ADDR_LINKLOCAL)
 328                 iif = skb->dev->ifindex;
 329
 330         /*
 331          *      Must not send if we know that source is Anycast also.
 332          *      for now we don't know that.
 333          */
 334         if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
 335                 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n");
 336                 return;
 337         }
 338
 339         /*
 340          *      Never answer to a ICMP packet.
 341          */
 342         if (is_ineligible(skb)) {
 343                 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n");
 344                 return;
 345         }
 346
 347         memset(&fl, 0, sizeof(fl));
 348         fl.proto = IPPROTO_ICMPV6;
 349         ipv6_addr_copy(&fl.fl6_dst, &hdr->saddr);
 350         if (saddr)
 351                 ipv6_addr_copy(&fl.fl6_src, saddr);
 352         fl.oif = iif;
 353         fl.fl_icmp_type = type;
 354         fl.fl_icmp_code = code;
 355
 356         if (icmpv6_xmit_lock())
 357                 return;
 358
 359         sk = icmpv6_socket->sk;
 360         np = inet6_sk(sk);
 361
 362         if (!icmpv6_xrlim_allow(sk, type, &fl))
 363                 goto out;
 364
 365         tmp_hdr.icmp6_type = type;
 366         tmp_hdr.icmp6_code = code;
 367         tmp_hdr.icmp6_cksum = 0;
 368         tmp_hdr.icmp6_pointer = htonl(info);
 369
 370         if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst))
 371                 fl.oif = np->mcast_oif;
 372
 373         err = ip6_dst_lookup(sk, &dst, &fl);
 374         if (err)
 375                 goto out;
 376         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
 377                 goto out;
 378
 379         if (ipv6_addr_is_multicast(&fl.fl6_dst))
 380                 hlimit = np->mcast_hops;
 381         else
 382                 hlimit = np->hop_limit;
 383         if (hlimit < 0)
 384                 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
 385         if (hlimit < 0)
 386                 hlimit = ipv6_get_hoplimit(dst->dev);
 387
 388         tclass = np->cork.tclass;
 389         if (tclass < 0)
 390                 tclass = 0;
 391
 392         msg.skb = skb;
 393         msg.offset = skb->nh.raw - skb->data;
 394
 395         len = skb->len - msg.offset;
 396         len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr));
 397         if (len < 0) {
 398                 LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n");
 399                 goto out_dst_release;
 400         }
 401
 402         idev = in6_dev_get(skb->dev);
 403
 404         err = ip6_append_data(sk, icmpv6_getfrag, &msg,
 405                               len + sizeof(struct icmp6hdr),
 406                               sizeof(struct icmp6hdr),
 407                               hlimit, tclass, NULL, &fl, (struct rt6_info*)dst,
 408                               MSG_DONTWAIT);
 409         if (err) {
 410                 ip6_flush_pending_frames(sk);
 411                 goto out_put;
 412         }
 413         err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr));
 414
 415         if (type >= ICMPV6_DEST_UNREACH && type <= ICMPV6_PARAMPROB)
 416                 ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_OUTDESTUNREACHS, type - ICMPV6_DEST_UNREACH);
 417         ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS);
 418
 419 out_put:
 420         if (likely(idev != NULL))
 421                 in6_dev_put(idev);
 422 out_dst_release:
 423         dst_release(dst);
 424 out:
 425         icmpv6_xmit_unlock();
 426 }
 427
 428 static void icmpv6_echo_reply(struct sk_buff *skb)
 429 {
 430         struct sock *sk;
 431         struct inet6_dev *idev;
 432         struct ipv6_pinfo *np;
 433         struct in6_addr *saddr = NULL;
 434         struct icmp6hdr *icmph = (struct icmp6hdr *) skb->h.raw;
 435         struct icmp6hdr tmp_hdr;
 436         struct flowi fl;
 437         struct icmpv6_msg msg;
 438         struct dst_entry *dst;
 439         int err = 0;
 440         int hlimit;
 441         int tclass;
 442
 443         saddr = &skb->nh.ipv6h->daddr;
 444
 445         if (!ipv6_unicast_destination(skb))
 446                 saddr = NULL;
 447
 448         memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
 449         tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
 450
 451         memset(&fl, 0, sizeof(fl));
 452         fl.proto = IPPROTO_ICMPV6;
 453         ipv6_addr_copy(&fl.fl6_dst, &skb->nh.ipv6h->saddr);
 454         if (saddr)
 455                 ipv6_addr_copy(&fl.fl6_src, saddr);
 456         fl.oif = skb->dev->ifindex;
 457         fl.fl_icmp_type = ICMPV6_ECHO_REPLY;
 458
 459         if (icmpv6_xmit_lock())
 460                 return;
 461
 462         sk = icmpv6_socket->sk;
 463         np = inet6_sk(sk);
 464
 465         if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst))
 466                 fl.oif = np->mcast_oif;
 467
 468         err = ip6_dst_lookup(sk, &dst, &fl);
 469         if (err)
 470                 goto out;
 471         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
 472                 goto out;
 473
 474         if (ipv6_addr_is_multicast(&fl.fl6_dst))
 475                 hlimit = np->mcast_hops;
 476         else
 477                 hlimit = np->hop_limit;
 478         if (hlimit < 0)
 479                 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
 480         if (hlimit < 0)
 481                 hlimit = ipv6_get_hoplimit(dst->dev);
 482
 483         tclass = np->cork.tclass;
 484         if (tclass < 0)
 485                 tclass = 0;
 486
 487         idev = in6_dev_get(skb->dev);
 488
 489         msg.skb = skb;
 490         msg.offset = 0;
 491
 492         err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
 493                                 sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl,
 494                                 (struct rt6_info*)dst, MSG_DONTWAIT);
 495
 496         if (err) {
 497                 ip6_flush_pending_frames(sk);
 498                 goto out_put;
 499         }
 500         err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, skb->len + sizeof(struct icmp6hdr));
 501
 502         ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTECHOREPLIES);
 503         ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS);
 504
 505 out_put:
 506         if (likely(idev != NULL))
 507                 in6_dev_put(idev);
 508         dst_release(dst);
 509 out:
 510         icmpv6_xmit_unlock();
 511 }
 512
 513 static void icmpv6_notify(struct sk_buff *skb, int type, int code, u32 info)
 514 {
 515         struct in6_addr *saddr, *daddr;
 516         struct inet6_protocol *ipprot;
 517         struct sock *sk;
 518         int inner_offset;
 519         int hash;
 520         u8 nexthdr;
 521
 522         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 523                 return;
 524
 525         nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
 526         if (ipv6_ext_hdr(nexthdr)) {
 527                 /* now skip over extension headers */
 528                 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
 529                 if (inner_offset<0)
 530                         return;
 531         } else {
 532                 inner_offset = sizeof(struct ipv6hdr);
 533         }
 534
 535         /* Checkin header including 8 bytes of inner protocol header. */
 536         if (!pskb_may_pull(skb, inner_offset+8))
 537                 return;
 538
 539         saddr = &skb->nh.ipv6h->saddr;
 540         daddr = &skb->nh.ipv6h->daddr;
 541
 542         /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
 543            Without this we will not able f.e. to make source routed
 544            pmtu discovery.
 545            Corresponding argument (opt) to notifiers is already added.
 546            --ANK (980726)
 547          */
 548
 549         hash = nexthdr & (MAX_INET_PROTOS - 1);
 550
 551         rcu_read_lock();
 552         ipprot = rcu_dereference(inet6_protos[hash]);
 553         if (ipprot && ipprot->err_handler)
 554                 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
 555         rcu_read_unlock();
 556
 557         read_lock(&raw_v6_lock);
 558         if ((sk = sk_head(&raw_v6_htable[hash])) != NULL) {
 559                 while((sk = __raw_v6_lookup(sk, nexthdr, daddr, saddr,
 560                                             IP6CB(skb)->iif))) {
 561                         rawv6_err(sk, skb, NULL, type, code, inner_offset, info);
 562                         sk = sk_next(sk);
 563                 }
 564         }
 565         read_unlock(&raw_v6_lock);
 566 }
 567
 568 /*
 569  *      Handle icmp messages
 570  */
 571
 572 static int icmpv6_rcv(struct sk_buff **pskb, unsigned int *nhoffp)
 573 {
 574         struct sk_buff *skb = *pskb;
 575         struct net_device *dev = skb->dev;
 576         struct inet6_dev *idev = __in6_dev_get(dev);
 577         struct in6_addr *saddr, *daddr;
 578         struct ipv6hdr *orig_hdr;
 579         struct icmp6hdr *hdr;
 580         int type;
 581
 582         ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INMSGS);
 583
 584         saddr = &skb->nh.ipv6h->saddr;
 585         daddr = &skb->nh.ipv6h->daddr;
 586
 587         /* Perform checksum. */
 588         if (skb->ip_summed == CHECKSUM_HW) {
 589                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 590                 if (csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
 591                                     skb->csum)) {
 592                         LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 hw checksum failed\n");
 593                         skb->ip_summed = CHECKSUM_NONE;
 594                 }
 595         }
 596         if (skb->ip_summed == CHECKSUM_NONE) {
 597                 if (csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
 598                                     skb_checksum(skb, 0, skb->len, 0))) {
 599                         LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x > %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x]\n",
 600                                        NIP6(*saddr), NIP6(*daddr));
 601                         goto discard_it;
 602                 }
 603         }
 604
 605         if (!pskb_pull(skb, sizeof(struct icmp6hdr)))
 606                 goto discard_it;
 607
 608         hdr = (struct icmp6hdr *) skb->h.raw;
 609
 610         type = hdr->icmp6_type;
 611
 612         if (type >= ICMPV6_DEST_UNREACH && type <= ICMPV6_PARAMPROB)
 613                 ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_INDESTUNREACHS, type - ICMPV6_DEST_UNREACH);
 614         else if (type >= ICMPV6_ECHO_REQUEST && type <= NDISC_REDIRECT)
 615                 ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_INECHOS, type - ICMPV6_ECHO_REQUEST);
 616
 617         switch (type) {
 618         case ICMPV6_ECHO_REQUEST:
 619                 icmpv6_echo_reply(skb);
 620                 break;
 621
 622         case ICMPV6_ECHO_REPLY:
 623                 /* we couldn't care less */
 624                 break;
 625
 626         case ICMPV6_PKT_TOOBIG:
 627                 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
 628                    standard destination cache. Seems, only "advanced"
 629                    destination cache will allow to solve this problem
 630                    --ANK (980726)
 631                  */
 632                 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 633                         goto discard_it;
 634                 hdr = (struct icmp6hdr *) skb->h.raw;
 635                 orig_hdr = (struct ipv6hdr *) (hdr + 1);
 636                 rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev,
 637                                    ntohl(hdr->icmp6_mtu));
 638
 639                 /*
 640                  *      Drop through to notify
 641                  */
 642
 643         case ICMPV6_DEST_UNREACH:
 644         case ICMPV6_TIME_EXCEED:
 645         case ICMPV6_PARAMPROB:
 646                 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 647                 break;
 648
 649         case NDISC_ROUTER_SOLICITATION:
 650         case NDISC_ROUTER_ADVERTISEMENT:
 651         case NDISC_NEIGHBOUR_SOLICITATION:
 652         case NDISC_NEIGHBOUR_ADVERTISEMENT:
 653         case NDISC_REDIRECT:
 654                 ndisc_rcv(skb);
 655                 break;
 656
 657         case ICMPV6_MGM_QUERY:
 658                 igmp6_event_query(skb);
 659                 break;
 660
 661         case ICMPV6_MGM_REPORT:
 662                 igmp6_event_report(skb);
 663                 break;
 664
 665         case ICMPV6_MGM_REDUCTION:
 666         case ICMPV6_NI_QUERY:
 667         case ICMPV6_NI_REPLY:
 668         case ICMPV6_MLD2_REPORT:
 669         case ICMPV6_DHAAD_REQUEST:
 670         case ICMPV6_DHAAD_REPLY:
 671         case ICMPV6_MOBILE_PREFIX_SOL:
 672         case ICMPV6_MOBILE_PREFIX_ADV:
 673                 break;
 674
 675         default:
 676                 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n");
 677
 678                 /* informational */
 679                 if (type & ICMPV6_INFOMSG_MASK)
 680                         break;
 681
 682                 /*
 683                  * error of unknown type.
 684                  * must pass to upper level
 685                  */
 686
 687                 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 688         };
 689         kfree_skb(skb);
 690         return 0;
 691
 692 discard_it:
 693         ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
 694         kfree_skb(skb);
 695         return 0;
 696 }
 697
 698 int __init icmpv6_init(struct net_proto_family *ops)
 699 {
 700         struct sock *sk;
 701         int err, i, j;
 702
 703         for (i = 0; i < NR_CPUS; i++) {
 704                 if (!cpu_possible(i))
 705                         continue;
 706
 707                 err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6,
 708                                        &per_cpu(__icmpv6_socket, i));
 709                 if (err < 0) {
 710                         printk(KERN_ERR
 711                                "Failed to initialize the ICMP6 control socket "
 712                                "(err %d).\n",
 713                                err);
 714                         goto fail;
 715                 }
 716
 717                 sk = per_cpu(__icmpv6_socket, i)->sk;
 718                 sk->sk_allocation = GFP_ATOMIC;
 719
 720                 /* Enough space for 2 64K ICMP packets, including
 721                  * sk_buff struct overhead.
 722                  */
 723                 sk->sk_sndbuf =
 724                         (2 * ((64 * 1024) + sizeof(struct sk_buff)));
 725
 726                 sk->sk_prot->unhash(sk);
 727         }
 728
 729
 730         if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) {
 731                 printk(KERN_ERR "Failed to register ICMP6 protocol\n");
 732                 err = -EAGAIN;
 733                 goto fail;
 734         }
 735
 736         return 0;
 737
 738  fail:
 739         for (j = 0; j < i; j++) {
 740                 if (!cpu_possible(j))
 741                         continue;
 742                 sock_release(per_cpu(__icmpv6_socket, j));
 743         }
 744
 745         return err;
 746 }
 747
 748 void icmpv6_cleanup(void)
 749 {
 750         int i;
 751
 752         for (i = 0; i < NR_CPUS; i++) {
 753                 if (!cpu_possible(i))
 754                         continue;
 755                 sock_release(per_cpu(__icmpv6_socket, i));
 756         }
 757         inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
 758 }
 759
 760 static struct icmp6_err {
 761         int err;
 762         int fatal;
 763 } tab_unreach[] = {
 764         {       /* NOROUTE */
 765                 .err    = ENETUNREACH,
 766                 .fatal  = 0,
 767         },
 768         {       /* ADM_PROHIBITED */
 769                 .err    = EACCES,
 770                 .fatal  = 1,
 771         },
 772         {       /* Was NOT_NEIGHBOUR, now reserved */
 773                 .err    = EHOSTUNREACH,
 774                 .fatal  = 0,
 775         },
 776         {       /* ADDR_UNREACH */
 777                 .err    = EHOSTUNREACH,
 778                 .fatal  = 0,
 779         },
 780         {       /* PORT_UNREACH */
 781                 .err    = ECONNREFUSED,
 782                 .fatal  = 1,
 783         },
 784 };
 785
 786 int icmpv6_err_convert(int type, int code, int *err)
 787 {
 788         int fatal = 0;
 789
 790         *err = EPROTO;
 791
 792         switch (type) {
 793         case ICMPV6_DEST_UNREACH:
 794                 fatal = 1;
 795                 if (code <= ICMPV6_PORT_UNREACH) {
 796                         *err  = tab_unreach[code].err;
 797                         fatal = tab_unreach[code].fatal;
 798                 }
 799                 break;
 800
 801         case ICMPV6_PKT_TOOBIG:
 802                 *err = EMSGSIZE;
 803                 break;
 804
 805         case ICMPV6_PARAMPROB:
 806                 *err = EPROTO;
 807                 fatal = 1;
 808                 break;
 809
 810         case ICMPV6_TIME_EXCEED:
 811                 *err = EHOSTUNREACH;
 812                 break;
 813         };
 814
 815         return fatal;
 816 }
 817
 818 #ifdef CONFIG_SYSCTL
 819 ctl_table ipv6_icmp_table[] = {
 820         {
 821                 .ctl_name       = NET_IPV6_ICMP_RATELIMIT,
 822                 .procname       = "ratelimit",
 823                 .data           = &sysctl_icmpv6_time,
 824                 .maxlen         = sizeof(int),
 825                 .mode           = 0644,
 826                 .proc_handler   = &proc_dointvec
 827         },
 828         { .ctl_name = 0 },
 829 };
 830 #endif
 831