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);
  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;
 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(
 336                         printk(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n"));
 337                 return;
 338         }
 339
 340         /*
 341          *      Never answer to a ICMP packet.
 342          */
 343         if (is_ineligible(skb)) {
 344                 LIMIT_NETDEBUG(
 345                         printk(KERN_DEBUG "icmpv6_send: no reply to icmp error\n"));
 346                 return;
 347         }
 348
 349         memset(&fl, 0, sizeof(fl));
 350         fl.proto = IPPROTO_ICMPV6;
 351         ipv6_addr_copy(&fl.fl6_dst, &hdr->saddr);
 352         if (saddr)
 353                 ipv6_addr_copy(&fl.fl6_src, saddr);
 354         fl.oif = iif;
 355         fl.fl_icmp_type = type;
 356         fl.fl_icmp_code = code;
 357
 358         if (icmpv6_xmit_lock())
 359                 return;
 360
 361         sk = icmpv6_socket->sk;
 362         np = inet6_sk(sk);
 363
 364         if (!icmpv6_xrlim_allow(sk, type, &fl))
 365                 goto out;
 366
 367         tmp_hdr.icmp6_type = type;
 368         tmp_hdr.icmp6_code = code;
 369         tmp_hdr.icmp6_cksum = 0;
 370         tmp_hdr.icmp6_pointer = htonl(info);
 371
 372         if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst))
 373                 fl.oif = np->mcast_oif;
 374
 375         err = ip6_dst_lookup(sk, &dst, &fl);
 376         if (err)
 377                 goto out;
 378         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
 379                 goto out_dst_release;
 380
 381         if (ipv6_addr_is_multicast(&fl.fl6_dst))
 382                 hlimit = np->mcast_hops;
 383         else
 384                 hlimit = np->hop_limit;
 385         if (hlimit < 0)
 386                 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
 387         if (hlimit < 0)
 388                 hlimit = ipv6_get_hoplimit(dst->dev);
 389
 390         msg.skb = skb;
 391         msg.offset = skb->nh.raw - skb->data;
 392
 393         len = skb->len - msg.offset;
 394         len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr));
 395         if (len < 0) {
 396                 LIMIT_NETDEBUG(
 397                         printk(KERN_DEBUG "icmp: len problem\n"));
 398                 goto out_dst_release;
 399         }
 400
 401         idev = in6_dev_get(skb->dev);
 402
 403         err = ip6_append_data(sk, icmpv6_getfrag, &msg,
 404                               len + sizeof(struct icmp6hdr),
 405                               sizeof(struct icmp6hdr),
 406                               hlimit, NULL, &fl, (struct rt6_info*)dst,
 407                               MSG_DONTWAIT);
 408         if (err) {
 409                 ip6_flush_pending_frames(sk);
 410                 goto out_put;
 411         }
 412         err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr));
 413
 414         if (type >= ICMPV6_DEST_UNREACH && type <= ICMPV6_PARAMPROB)
 415                 ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_OUTDESTUNREACHS, type - ICMPV6_DEST_UNREACH);
 416         ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS);
 417
 418 out_put:
 419         if (likely(idev != NULL))
 420                 in6_dev_put(idev);
 421 out_dst_release:
 422         dst_release(dst);
 423 out:
 424         icmpv6_xmit_unlock();
 425 }
 426
 427 static void icmpv6_echo_reply(struct sk_buff *skb)
 428 {
 429         struct sock *sk;
 430         struct inet6_dev *idev;
 431         struct ipv6_pinfo *np;
 432         struct in6_addr *saddr = NULL;
 433         struct icmp6hdr *icmph = (struct icmp6hdr *) skb->h.raw;
 434         struct icmp6hdr tmp_hdr;
 435         struct flowi fl;
 436         struct icmpv6_msg msg;
 437         struct dst_entry *dst;
 438         int err = 0;
 439         int hlimit;
 440
 441         saddr = &skb->nh.ipv6h->daddr;
 442
 443         if (!ipv6_unicast_destination(skb))
 444                 saddr = NULL;
 445
 446         memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
 447         tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
 448
 449         memset(&fl, 0, sizeof(fl));
 450         fl.proto = IPPROTO_ICMPV6;
 451         ipv6_addr_copy(&fl.fl6_dst, &skb->nh.ipv6h->saddr);
 452         if (saddr)
 453                 ipv6_addr_copy(&fl.fl6_src, saddr);
 454         fl.oif = skb->dev->ifindex;
 455         fl.fl_icmp_type = ICMPV6_ECHO_REPLY;
 456
 457         if (icmpv6_xmit_lock())
 458                 return;
 459
 460         sk = icmpv6_socket->sk;
 461         np = inet6_sk(sk);
 462
 463         if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst))
 464                 fl.oif = np->mcast_oif;
 465
 466         err = ip6_dst_lookup(sk, &dst, &fl);
 467         if (err)
 468                 goto out;
 469         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
 470                 goto out_dst_release;
 471
 472         if (ipv6_addr_is_multicast(&fl.fl6_dst))
 473                 hlimit = np->mcast_hops;
 474         else
 475                 hlimit = np->hop_limit;
 476         if (hlimit < 0)
 477                 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
 478         if (hlimit < 0)
 479                 hlimit = ipv6_get_hoplimit(dst->dev);
 480
 481         idev = in6_dev_get(skb->dev);
 482
 483         msg.skb = skb;
 484         msg.offset = 0;
 485
 486         err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
 487                                 sizeof(struct icmp6hdr), hlimit, NULL, &fl,
 488                                 (struct rt6_info*)dst, MSG_DONTWAIT);
 489
 490         if (err) {
 491                 ip6_flush_pending_frames(sk);
 492                 goto out_put;
 493         }
 494         err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, skb->len + sizeof(struct icmp6hdr));
 495
 496         ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTECHOREPLIES);
 497         ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS);
 498
 499 out_put:
 500         if (likely(idev != NULL))
 501                 in6_dev_put(idev);
 502 out_dst_release:
 503         dst_release(dst);
 504 out:
 505         icmpv6_xmit_unlock();
 506 }
 507
 508 static void icmpv6_notify(struct sk_buff *skb, int type, int code, u32 info)
 509 {
 510         struct in6_addr *saddr, *daddr;
 511         struct inet6_protocol *ipprot;
 512         struct sock *sk;
 513         int inner_offset;
 514         int hash;
 515         u8 nexthdr;
 516
 517         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 518                 return;
 519
 520         nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
 521         if (ipv6_ext_hdr(nexthdr)) {
 522                 /* now skip over extension headers */
 523                 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
 524                 if (inner_offset<0)
 525                         return;
 526         } else {
 527                 inner_offset = sizeof(struct ipv6hdr);
 528         }
 529
 530         /* Checkin header including 8 bytes of inner protocol header. */
 531         if (!pskb_may_pull(skb, inner_offset+8))
 532                 return;
 533
 534         saddr = &skb->nh.ipv6h->saddr;
 535         daddr = &skb->nh.ipv6h->daddr;
 536
 537         /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
 538            Without this we will not able f.e. to make source routed
 539            pmtu discovery.
 540            Corresponding argument (opt) to notifiers is already added.
 541            --ANK (980726)
 542          */
 543
 544         hash = nexthdr & (MAX_INET_PROTOS - 1);
 545
 546         rcu_read_lock();
 547         ipprot = rcu_dereference(inet6_protos[hash]);
 548         if (ipprot && ipprot->err_handler)
 549                 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
 550         rcu_read_unlock();
 551
 552         read_lock(&raw_v6_lock);
 553         if ((sk = sk_head(&raw_v6_htable[hash])) != NULL) {
 554                 while((sk = __raw_v6_lookup(sk, nexthdr, daddr, saddr))) {
 555                         rawv6_err(sk, skb, NULL, type, code, inner_offset, info);
 556                         sk = sk_next(sk);
 557                 }
 558         }
 559         read_unlock(&raw_v6_lock);
 560 }
 561
 562 /*
 563  *      Handle icmp messages
 564  */
 565
 566 static int icmpv6_rcv(struct sk_buff **pskb, unsigned int *nhoffp)
 567 {
 568         struct sk_buff *skb = *pskb;
 569         struct net_device *dev = skb->dev;
 570         struct inet6_dev *idev = __in6_dev_get(dev);
 571         struct in6_addr *saddr, *daddr;
 572         struct ipv6hdr *orig_hdr;
 573         struct icmp6hdr *hdr;
 574         int type;
 575
 576         ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INMSGS);
 577
 578         saddr = &skb->nh.ipv6h->saddr;
 579         daddr = &skb->nh.ipv6h->daddr;
 580
 581         /* Perform checksum. */
 582         if (skb->ip_summed == CHECKSUM_HW) {
 583                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 584                 if (csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
 585                                     skb->csum)) {
 586                         LIMIT_NETDEBUG(
 587                                 printk(KERN_DEBUG "ICMPv6 hw checksum failed\n"));
 588                         skb->ip_summed = CHECKSUM_NONE;
 589                 }
 590         }
 591         if (skb->ip_summed == CHECKSUM_NONE) {
 592                 if (csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
 593                                     skb_checksum(skb, 0, skb->len, 0))) {
 594                         LIMIT_NETDEBUG(
 595                                 printk(KERN_DEBUG "ICMPv6 checksum failed [%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x > %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x]\n",
 596                                        NIP6(*saddr), NIP6(*daddr)));
 597                         goto discard_it;
 598                 }
 599         }
 600
 601         if (!pskb_pull(skb, sizeof(struct icmp6hdr)))
 602                 goto discard_it;
 603
 604         hdr = (struct icmp6hdr *) skb->h.raw;
 605
 606         type = hdr->icmp6_type;
 607
 608         if (type >= ICMPV6_DEST_UNREACH && type <= ICMPV6_PARAMPROB)
 609                 ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_INDESTUNREACHS, type - ICMPV6_DEST_UNREACH);
 610         else if (type >= ICMPV6_ECHO_REQUEST && type <= NDISC_REDIRECT)
 611                 ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_INECHOS, type - ICMPV6_ECHO_REQUEST);
 612
 613         switch (type) {
 614         case ICMPV6_ECHO_REQUEST:
 615                 icmpv6_echo_reply(skb);
 616                 break;
 617
 618         case ICMPV6_ECHO_REPLY:
 619                 /* we couldn't care less */
 620                 break;
 621
 622         case ICMPV6_PKT_TOOBIG:
 623                 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
 624                    standard destination cache. Seems, only "advanced"
 625                    destination cache will allow to solve this problem
 626                    --ANK (980726)
 627                  */
 628                 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 629                         goto discard_it;
 630                 hdr = (struct icmp6hdr *) skb->h.raw;
 631                 orig_hdr = (struct ipv6hdr *) (hdr + 1);
 632                 rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev,
 633                                    ntohl(hdr->icmp6_mtu));
 634
 635                 /*
 636                  *      Drop through to notify
 637                  */
 638
 639         case ICMPV6_DEST_UNREACH:
 640         case ICMPV6_TIME_EXCEED:
 641         case ICMPV6_PARAMPROB:
 642                 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 643                 break;
 644
 645         case NDISC_ROUTER_SOLICITATION:
 646         case NDISC_ROUTER_ADVERTISEMENT:
 647         case NDISC_NEIGHBOUR_SOLICITATION:
 648         case NDISC_NEIGHBOUR_ADVERTISEMENT:
 649         case NDISC_REDIRECT:
 650                 ndisc_rcv(skb);
 651                 break;
 652
 653         case ICMPV6_MGM_QUERY:
 654                 igmp6_event_query(skb);
 655                 break;
 656
 657         case ICMPV6_MGM_REPORT:
 658                 igmp6_event_report(skb);
 659                 break;
 660
 661         case ICMPV6_MGM_REDUCTION:
 662         case ICMPV6_NI_QUERY:
 663         case ICMPV6_NI_REPLY:
 664         case ICMPV6_MLD2_REPORT:
 665         case ICMPV6_DHAAD_REQUEST:
 666         case ICMPV6_DHAAD_REPLY:
 667         case ICMPV6_MOBILE_PREFIX_SOL:
 668         case ICMPV6_MOBILE_PREFIX_ADV:
 669                 break;
 670
 671         default:
 672                 LIMIT_NETDEBUG(
 673                         printk(KERN_DEBUG "icmpv6: msg of unknown type\n"));
 674
 675                 /* informational */
 676                 if (type & ICMPV6_INFOMSG_MASK)
 677                         break;
 678
 679                 /*
 680                  * error of unknown type.
 681                  * must pass to upper level
 682                  */
 683
 684                 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 685         };
 686         kfree_skb(skb);
 687         return 0;
 688
 689 discard_it:
 690         ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
 691         kfree_skb(skb);
 692         return 0;
 693 }
 694
 695 int __init icmpv6_init(struct net_proto_family *ops)
 696 {
 697         struct sock *sk;
 698         int err, i, j;
 699
 700         for (i = 0; i < NR_CPUS; i++) {
 701                 if (!cpu_possible(i))
 702                         continue;
 703
 704                 err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6,
 705                                        &per_cpu(__icmpv6_socket, i));
 706                 if (err < 0) {
 707                         printk(KERN_ERR
 708                                "Failed to initialize the ICMP6 control socket "
 709                                "(err %d).\n",
 710                                err);
 711                         goto fail;
 712                 }
 713
 714                 sk = per_cpu(__icmpv6_socket, i)->sk;
 715                 sk->sk_allocation = GFP_ATOMIC;
 716
 717                 /* Enough space for 2 64K ICMP packets, including
 718                  * sk_buff struct overhead.
 719                  */
 720                 sk->sk_sndbuf =
 721                         (2 * ((64 * 1024) + sizeof(struct sk_buff)));
 722
 723                 sk->sk_prot->unhash(sk);
 724         }
 725
 726
 727         if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) {
 728                 printk(KERN_ERR "Failed to register ICMP6 protocol\n");
 729                 err = -EAGAIN;
 730                 goto fail;
 731         }
 732
 733         return 0;
 734
 735  fail:
 736         for (j = 0; j < i; j++) {
 737                 if (!cpu_possible(j))
 738                         continue;
 739                 sock_release(per_cpu(__icmpv6_socket, j));
 740         }
 741
 742         return err;
 743 }
 744
 745 void icmpv6_cleanup(void)
 746 {
 747         int i;
 748
 749         for (i = 0; i < NR_CPUS; i++) {
 750                 if (!cpu_possible(i))
 751                         continue;
 752                 sock_release(per_cpu(__icmpv6_socket, i));
 753         }
 754         inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
 755 }
 756
 757 static struct icmp6_err {
 758         int err;
 759         int fatal;
 760 } tab_unreach[] = {
 761         {       /* NOROUTE */
 762                 .err    = ENETUNREACH,
 763                 .fatal  = 0,
 764         },
 765         {       /* ADM_PROHIBITED */
 766                 .err    = EACCES,
 767                 .fatal  = 1,
 768         },
 769         {       /* Was NOT_NEIGHBOUR, now reserved */
 770                 .err    = EHOSTUNREACH,
 771                 .fatal  = 0,
 772         },
 773         {       /* ADDR_UNREACH */
 774                 .err    = EHOSTUNREACH,
 775                 .fatal  = 0,
 776         },
 777         {       /* PORT_UNREACH */
 778                 .err    = ECONNREFUSED,
 779                 .fatal  = 1,
 780         },
 781 };
 782
 783 int icmpv6_err_convert(int type, int code, int *err)
 784 {
 785         int fatal = 0;
 786
 787         *err = EPROTO;
 788
 789         switch (type) {
 790         case ICMPV6_DEST_UNREACH:
 791                 fatal = 1;
 792                 if (code <= ICMPV6_PORT_UNREACH) {
 793                         *err  = tab_unreach[code].err;
 794                         fatal = tab_unreach[code].fatal;
 795                 }
 796                 break;
 797
 798         case ICMPV6_PKT_TOOBIG:
 799                 *err = EMSGSIZE;
 800                 break;
 801
 802         case ICMPV6_PARAMPROB:
 803                 *err = EPROTO;
 804                 fatal = 1;
 805                 break;
 806
 807         case ICMPV6_TIME_EXCEED:
 808                 *err = EHOSTUNREACH;
 809                 break;
 810         };
 811
 812         return fatal;
 813 }
 814
 815 #ifdef CONFIG_SYSCTL
 816 ctl_table ipv6_icmp_table[] = {
 817         {
 818                 .ctl_name       = NET_IPV6_ICMP_RATELIMIT,
 819                 .procname       = "ratelimit",
 820                 .data           = &sysctl_icmpv6_time,
 821                 .maxlen         = sizeof(int),
 822                 .mode           = 0644,
 823                 .proc_handler   = &proc_dointvec
 824         },
 825         { .ctl_name = 0 },
 826 };
 827 #endif
 828