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