git.oblomov.eu Git - linux-2.6/blob - net/ipv6/netfilter/ip6_tables.c

   1 /*
   2  * Packet matching code.
   3  *
   4  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
   5  * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/capability.h>
  13 #include <linux/in.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/kmod.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/module.h>
  19 #include <linux/poison.h>
  20 #include <linux/icmpv6.h>
  21 #include <net/ipv6.h>
  22 #include <asm/uaccess.h>
  23 #include <linux/mutex.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/cpumask.h>
  26
  27 #include <linux/netfilter_ipv6/ip6_tables.h>
  28 #include <linux/netfilter/x_tables.h>
  29
  30 MODULE_LICENSE("GPL");
  31 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  32 MODULE_DESCRIPTION("IPv6 packet filter");
  33
  34 #define IPV6_HDR_LEN    (sizeof(struct ipv6hdr))
  35 #define IPV6_OPTHDR_LEN (sizeof(struct ipv6_opt_hdr))
  36
  37 /*#define DEBUG_IP_FIREWALL*/
  38 /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
  39 /*#define DEBUG_IP_FIREWALL_USER*/
  40
  41 #ifdef DEBUG_IP_FIREWALL
  42 #define dprintf(format, args...)  printk(format , ## args)
  43 #else
  44 #define dprintf(format, args...)
  45 #endif
  46
  47 #ifdef DEBUG_IP_FIREWALL_USER
  48 #define duprintf(format, args...) printk(format , ## args)
  49 #else
  50 #define duprintf(format, args...)
  51 #endif
  52
  53 #ifdef CONFIG_NETFILTER_DEBUG
  54 #define IP_NF_ASSERT(x)                                         \
  55 do {                                                            \
  56         if (!(x))                                               \
  57                 printk("IP_NF_ASSERT: %s:%s:%u\n",              \
  58                        __FUNCTION__, __FILE__, __LINE__);       \
  59 } while(0)
  60 #else
  61 #define IP_NF_ASSERT(x)
  62 #endif
  63
  64 #if 0
  65 /* All the better to debug you with... */
  66 #define static
  67 #define inline
  68 #endif
  69
  70 /*
  71    We keep a set of rules for each CPU, so we can avoid write-locking
  72    them in the softirq when updating the counters and therefore
  73    only need to read-lock in the softirq; doing a write_lock_bh() in user
  74    context stops packets coming through and allows user context to read
  75    the counters or update the rules.
  76
  77    Hence the start of any table is given by get_table() below.  */
  78
  79 #if 0
  80 #define down(x) do { printk("DOWN:%u:" #x "\n", __LINE__); down(x); } while(0)
  81 #define down_interruptible(x) ({ int __r; printk("DOWNi:%u:" #x "\n", __LINE__); __r = down_interruptible(x); if (__r != 0) printk("ABORT-DOWNi:%u\n", __LINE__); __r; })
  82 #define up(x) do { printk("UP:%u:" #x "\n", __LINE__); up(x); } while(0)
  83 #endif
  84
  85 /* Check for an extension */
  86 int
  87 ip6t_ext_hdr(u8 nexthdr)
  88 {
  89         return ( (nexthdr == IPPROTO_HOPOPTS)   ||
  90                  (nexthdr == IPPROTO_ROUTING)   ||
  91                  (nexthdr == IPPROTO_FRAGMENT)  ||
  92                  (nexthdr == IPPROTO_ESP)       ||
  93                  (nexthdr == IPPROTO_AH)        ||
  94                  (nexthdr == IPPROTO_NONE)      ||
  95                  (nexthdr == IPPROTO_DSTOPTS) );
  96 }
  97
  98 /* Returns whether matches rule or not. */
  99 static inline bool
 100 ip6_packet_match(const struct sk_buff *skb,
 101                  const char *indev,
 102                  const char *outdev,
 103                  const struct ip6t_ip6 *ip6info,
 104                  unsigned int *protoff,
 105                  int *fragoff, bool *hotdrop)
 106 {
 107         size_t i;
 108         unsigned long ret;
 109         const struct ipv6hdr *ipv6 = ipv6_hdr(skb);
 110
 111 #define FWINV(bool,invflg) ((bool) ^ !!(ip6info->invflags & invflg))
 112
 113         if (FWINV(ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk,
 114                                        &ip6info->src), IP6T_INV_SRCIP)
 115             || FWINV(ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk,
 116                                           &ip6info->dst), IP6T_INV_DSTIP)) {
 117                 dprintf("Source or dest mismatch.\n");
 118 /*
 119                 dprintf("SRC: %u. Mask: %u. Target: %u.%s\n", ip->saddr,
 120                         ipinfo->smsk.s_addr, ipinfo->src.s_addr,
 121                         ipinfo->invflags & IP6T_INV_SRCIP ? " (INV)" : "");
 122                 dprintf("DST: %u. Mask: %u. Target: %u.%s\n", ip->daddr,
 123                         ipinfo->dmsk.s_addr, ipinfo->dst.s_addr,
 124                         ipinfo->invflags & IP6T_INV_DSTIP ? " (INV)" : "");*/
 125                 return false;
 126         }
 127
 128         /* Look for ifname matches; this should unroll nicely. */
 129         for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
 130                 ret |= (((const unsigned long *)indev)[i]
 131                         ^ ((const unsigned long *)ip6info->iniface)[i])
 132                         & ((const unsigned long *)ip6info->iniface_mask)[i];
 133         }
 134
 135         if (FWINV(ret != 0, IP6T_INV_VIA_IN)) {
 136                 dprintf("VIA in mismatch (%s vs %s).%s\n",
 137                         indev, ip6info->iniface,
 138                         ip6info->invflags&IP6T_INV_VIA_IN ?" (INV)":"");
 139                 return false;
 140         }
 141
 142         for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
 143                 ret |= (((const unsigned long *)outdev)[i]
 144                         ^ ((const unsigned long *)ip6info->outiface)[i])
 145                         & ((const unsigned long *)ip6info->outiface_mask)[i];
 146         }
 147
 148         if (FWINV(ret != 0, IP6T_INV_VIA_OUT)) {
 149                 dprintf("VIA out mismatch (%s vs %s).%s\n",
 150                         outdev, ip6info->outiface,
 151                         ip6info->invflags&IP6T_INV_VIA_OUT ?" (INV)":"");
 152                 return false;
 153         }
 154
 155 /* ... might want to do something with class and flowlabel here ... */
 156
 157         /* look for the desired protocol header */
 158         if((ip6info->flags & IP6T_F_PROTO)) {
 159                 int protohdr;
 160                 unsigned short _frag_off;
 161
 162                 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off);
 163                 if (protohdr < 0) {
 164                         if (_frag_off == 0)
 165                                 *hotdrop = true;
 166                         return false;
 167                 }
 168                 *fragoff = _frag_off;
 169
 170                 dprintf("Packet protocol %hi ?= %s%hi.\n",
 171                                 protohdr,
 172                                 ip6info->invflags & IP6T_INV_PROTO ? "!":"",
 173                                 ip6info->proto);
 174
 175                 if (ip6info->proto == protohdr) {
 176                         if(ip6info->invflags & IP6T_INV_PROTO) {
 177                                 return false;
 178                         }
 179                         return true;
 180                 }
 181
 182                 /* We need match for the '-p all', too! */
 183                 if ((ip6info->proto != 0) &&
 184                         !(ip6info->invflags & IP6T_INV_PROTO))
 185                         return false;
 186         }
 187         return true;
 188 }
 189
 190 /* should be ip6 safe */
 191 static inline bool
 192 ip6_checkentry(const struct ip6t_ip6 *ipv6)
 193 {
 194         if (ipv6->flags & ~IP6T_F_MASK) {
 195                 duprintf("Unknown flag bits set: %08X\n",
 196                          ipv6->flags & ~IP6T_F_MASK);
 197                 return false;
 198         }
 199         if (ipv6->invflags & ~IP6T_INV_MASK) {
 200                 duprintf("Unknown invflag bits set: %08X\n",
 201                          ipv6->invflags & ~IP6T_INV_MASK);
 202                 return false;
 203         }
 204         return true;
 205 }
 206
 207 static unsigned int
 208 ip6t_error(struct sk_buff **pskb,
 209           const struct net_device *in,
 210           const struct net_device *out,
 211           unsigned int hooknum,
 212           const struct xt_target *target,
 213           const void *targinfo)
 214 {
 215         if (net_ratelimit())
 216                 printk("ip6_tables: error: `%s'\n", (char *)targinfo);
 217
 218         return NF_DROP;
 219 }
 220
 221 static inline
 222 bool do_match(struct ip6t_entry_match *m,
 223               const struct sk_buff *skb,
 224               const struct net_device *in,
 225               const struct net_device *out,
 226               int offset,
 227               unsigned int protoff,
 228               bool *hotdrop)
 229 {
 230         /* Stop iteration if it doesn't match */
 231         if (!m->u.kernel.match->match(skb, in, out, m->u.kernel.match, m->data,
 232                                       offset, protoff, hotdrop))
 233                 return true;
 234         else
 235                 return false;
 236 }
 237
 238 static inline struct ip6t_entry *
 239 get_entry(void *base, unsigned int offset)
 240 {
 241         return (struct ip6t_entry *)(base + offset);
 242 }
 243
 244 /* All zeroes == unconditional rule. */
 245 static inline int
 246 unconditional(const struct ip6t_ip6 *ipv6)
 247 {
 248         unsigned int i;
 249
 250         for (i = 0; i < sizeof(*ipv6); i++)
 251                 if (((char *)ipv6)[i])
 252                         break;
 253
 254         return (i == sizeof(*ipv6));
 255 }
 256
 257 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
 258     defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
 259 /* This cries for unification! */
 260 static const char *hooknames[] = {
 261         [NF_IP6_PRE_ROUTING]            = "PREROUTING",
 262         [NF_IP6_LOCAL_IN]               = "INPUT",
 263         [NF_IP6_FORWARD]                = "FORWARD",
 264         [NF_IP6_LOCAL_OUT]              = "OUTPUT",
 265         [NF_IP6_POST_ROUTING]           = "POSTROUTING",
 266 };
 267
 268 enum nf_ip_trace_comments {
 269         NF_IP6_TRACE_COMMENT_RULE,
 270         NF_IP6_TRACE_COMMENT_RETURN,
 271         NF_IP6_TRACE_COMMENT_POLICY,
 272 };
 273
 274 static const char *comments[] = {
 275         [NF_IP6_TRACE_COMMENT_RULE]     = "rule",
 276         [NF_IP6_TRACE_COMMENT_RETURN]   = "return",
 277         [NF_IP6_TRACE_COMMENT_POLICY]   = "policy",
 278 };
 279
 280 static struct nf_loginfo trace_loginfo = {
 281         .type = NF_LOG_TYPE_LOG,
 282         .u = {
 283                 .log = {
 284                         .level = 4,
 285                         .logflags = NF_LOG_MASK,
 286                 },
 287         },
 288 };
 289
 290 static inline int
 291 get_chainname_rulenum(struct ip6t_entry *s, struct ip6t_entry *e,
 292                       char *hookname, char **chainname,
 293                       char **comment, unsigned int *rulenum)
 294 {
 295         struct ip6t_standard_target *t = (void *)ip6t_get_target(s);
 296
 297         if (strcmp(t->target.u.kernel.target->name, IP6T_ERROR_TARGET) == 0) {
 298                 /* Head of user chain: ERROR target with chainname */
 299                 *chainname = t->target.data;
 300                 (*rulenum) = 0;
 301         } else if (s == e) {
 302                 (*rulenum)++;
 303
 304                 if (s->target_offset == sizeof(struct ip6t_entry)
 305                    && strcmp(t->target.u.kernel.target->name,
 306                              IP6T_STANDARD_TARGET) == 0
 307                    && t->verdict < 0
 308                    && unconditional(&s->ipv6)) {
 309                         /* Tail of chains: STANDARD target (return/policy) */
 310                         *comment = *chainname == hookname
 311                                 ? (char *)comments[NF_IP6_TRACE_COMMENT_POLICY]
 312                                 : (char *)comments[NF_IP6_TRACE_COMMENT_RETURN];
 313                 }
 314                 return 1;
 315         } else
 316                 (*rulenum)++;
 317
 318         return 0;
 319 }
 320
 321 static void trace_packet(struct sk_buff *skb,
 322                          unsigned int hook,
 323                          const struct net_device *in,
 324                          const struct net_device *out,
 325                          char *tablename,
 326                          struct xt_table_info *private,
 327                          struct ip6t_entry *e)
 328 {
 329         void *table_base;
 330         struct ip6t_entry *root;
 331         char *hookname, *chainname, *comment;
 332         unsigned int rulenum = 0;
 333
 334         table_base = (void *)private->entries[smp_processor_id()];
 335         root = get_entry(table_base, private->hook_entry[hook]);
 336
 337         hookname = chainname = (char *)hooknames[hook];
 338         comment = (char *)comments[NF_IP6_TRACE_COMMENT_RULE];
 339
 340         IP6T_ENTRY_ITERATE(root,
 341                            private->size - private->hook_entry[hook],
 342                            get_chainname_rulenum,
 343                            e, hookname, &chainname, &comment, &rulenum);
 344
 345         nf_log_packet(AF_INET6, hook, skb, in, out, &trace_loginfo,
 346                       "TRACE: %s:%s:%s:%u ",
 347                       tablename, chainname, comment, rulenum);
 348 }
 349 #endif
 350
 351 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
 352 unsigned int
 353 ip6t_do_table(struct sk_buff **pskb,
 354               unsigned int hook,
 355               const struct net_device *in,
 356               const struct net_device *out,
 357               struct xt_table *table)
 358 {
 359         static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
 360         int offset = 0;
 361         unsigned int protoff = 0;
 362         bool hotdrop = false;
 363         /* Initializing verdict to NF_DROP keeps gcc happy. */
 364         unsigned int verdict = NF_DROP;
 365         const char *indev, *outdev;
 366         void *table_base;
 367         struct ip6t_entry *e, *back;
 368         struct xt_table_info *private;
 369
 370         /* Initialization */
 371         indev = in ? in->name : nulldevname;
 372         outdev = out ? out->name : nulldevname;
 373         /* We handle fragments by dealing with the first fragment as
 374          * if it was a normal packet.  All other fragments are treated
 375          * normally, except that they will NEVER match rules that ask
 376          * things we don't know, ie. tcp syn flag or ports).  If the
 377          * rule is also a fragment-specific rule, non-fragments won't
 378          * match it. */
 379
 380         read_lock_bh(&table->lock);
 381         private = table->private;
 382         IP_NF_ASSERT(table->valid_hooks & (1 << hook));
 383         table_base = (void *)private->entries[smp_processor_id()];
 384         e = get_entry(table_base, private->hook_entry[hook]);
 385
 386         /* For return from builtin chain */
 387         back = get_entry(table_base, private->underflow[hook]);
 388
 389         do {
 390                 IP_NF_ASSERT(e);
 391                 IP_NF_ASSERT(back);
 392                 if (ip6_packet_match(*pskb, indev, outdev, &e->ipv6,
 393                         &protoff, &offset, &hotdrop)) {
 394                         struct ip6t_entry_target *t;
 395
 396                         if (IP6T_MATCH_ITERATE(e, do_match,
 397                                                *pskb, in, out,
 398                                                offset, protoff, &hotdrop) != 0)
 399                                 goto no_match;
 400
 401                         ADD_COUNTER(e->counters,
 402                                     ntohs(ipv6_hdr(*pskb)->payload_len)
 403                                     + IPV6_HDR_LEN,
 404                                     1);
 405
 406                         t = ip6t_get_target(e);
 407                         IP_NF_ASSERT(t->u.kernel.target);
 408
 409 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
 410     defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
 411                         /* The packet is traced: log it */
 412                         if (unlikely((*pskb)->nf_trace))
 413                                 trace_packet(*pskb, hook, in, out,
 414                                              table->name, private, e);
 415 #endif
 416                         /* Standard target? */
 417                         if (!t->u.kernel.target->target) {
 418                                 int v;
 419
 420                                 v = ((struct ip6t_standard_target *)t)->verdict;
 421                                 if (v < 0) {
 422                                         /* Pop from stack? */
 423                                         if (v != IP6T_RETURN) {
 424                                                 verdict = (unsigned)(-v) - 1;
 425                                                 break;
 426                                         }
 427                                         e = back;
 428                                         back = get_entry(table_base,
 429                                                          back->comefrom);
 430                                         continue;
 431                                 }
 432                                 if (table_base + v != (void *)e + e->next_offset
 433                                     && !(e->ipv6.flags & IP6T_F_GOTO)) {
 434                                         /* Save old back ptr in next entry */
 435                                         struct ip6t_entry *next
 436                                                 = (void *)e + e->next_offset;
 437                                         next->comefrom
 438                                                 = (void *)back - table_base;
 439                                         /* set back pointer to next entry */
 440                                         back = next;
 441                                 }
 442
 443                                 e = get_entry(table_base, v);
 444                         } else {
 445                                 /* Targets which reenter must return
 446                                    abs. verdicts */
 447 #ifdef CONFIG_NETFILTER_DEBUG
 448                                 ((struct ip6t_entry *)table_base)->comefrom
 449                                         = 0xeeeeeeec;
 450 #endif
 451                                 verdict = t->u.kernel.target->target(pskb,
 452                                                                      in, out,
 453                                                                      hook,
 454                                                                      t->u.kernel.target,
 455                                                                      t->data);
 456
 457 #ifdef CONFIG_NETFILTER_DEBUG
 458                                 if (((struct ip6t_entry *)table_base)->comefrom
 459                                     != 0xeeeeeeec
 460                                     && verdict == IP6T_CONTINUE) {
 461                                         printk("Target %s reentered!\n",
 462                                                t->u.kernel.target->name);
 463                                         verdict = NF_DROP;
 464                                 }
 465                                 ((struct ip6t_entry *)table_base)->comefrom
 466                                         = 0x57acc001;
 467 #endif
 468                                 if (verdict == IP6T_CONTINUE)
 469                                         e = (void *)e + e->next_offset;
 470                                 else
 471                                         /* Verdict */
 472                                         break;
 473                         }
 474                 } else {
 475
 476                 no_match:
 477                         e = (void *)e + e->next_offset;
 478                 }
 479         } while (!hotdrop);
 480
 481 #ifdef CONFIG_NETFILTER_DEBUG
 482         ((struct ip6t_entry *)table_base)->comefrom = NETFILTER_LINK_POISON;
 483 #endif
 484         read_unlock_bh(&table->lock);
 485
 486 #ifdef DEBUG_ALLOW_ALL
 487         return NF_ACCEPT;
 488 #else
 489         if (hotdrop)
 490                 return NF_DROP;
 491         else return verdict;
 492 #endif
 493 }
 494
 495 /* Figures out from what hook each rule can be called: returns 0 if
 496    there are loops.  Puts hook bitmask in comefrom. */
 497 static int
 498 mark_source_chains(struct xt_table_info *newinfo,
 499                    unsigned int valid_hooks, void *entry0)
 500 {
 501         unsigned int hook;
 502
 503         /* No recursion; use packet counter to save back ptrs (reset
 504            to 0 as we leave), and comefrom to save source hook bitmask */
 505         for (hook = 0; hook < NF_IP6_NUMHOOKS; hook++) {
 506                 unsigned int pos = newinfo->hook_entry[hook];
 507                 struct ip6t_entry *e
 508                         = (struct ip6t_entry *)(entry0 + pos);
 509                 int visited = e->comefrom & (1 << hook);
 510
 511                 if (!(valid_hooks & (1 << hook)))
 512                         continue;
 513
 514                 /* Set initial back pointer. */
 515                 e->counters.pcnt = pos;
 516
 517                 for (;;) {
 518                         struct ip6t_standard_target *t
 519                                 = (void *)ip6t_get_target(e);
 520
 521                         if (e->comefrom & (1 << NF_IP6_NUMHOOKS)) {
 522                                 printk("iptables: loop hook %u pos %u %08X.\n",
 523                                        hook, pos, e->comefrom);
 524                                 return 0;
 525                         }
 526                         e->comefrom
 527                                 |= ((1 << hook) | (1 << NF_IP6_NUMHOOKS));
 528
 529                         /* Unconditional return/END. */
 530                         if ((e->target_offset == sizeof(struct ip6t_entry)
 531                             && (strcmp(t->target.u.user.name,
 532                                        IP6T_STANDARD_TARGET) == 0)
 533                             && t->verdict < 0
 534                             && unconditional(&e->ipv6)) || visited) {
 535                                 unsigned int oldpos, size;
 536
 537                                 if (t->verdict < -NF_MAX_VERDICT - 1) {
 538                                         duprintf("mark_source_chains: bad "
 539                                                 "negative verdict (%i)\n",
 540                                                                 t->verdict);
 541                                         return 0;
 542                                 }
 543
 544                                 /* Return: backtrack through the last
 545                                    big jump. */
 546                                 do {
 547                                         e->comefrom ^= (1<<NF_IP6_NUMHOOKS);
 548 #ifdef DEBUG_IP_FIREWALL_USER
 549                                         if (e->comefrom
 550                                             & (1 << NF_IP6_NUMHOOKS)) {
 551                                                 duprintf("Back unset "
 552                                                          "on hook %u "
 553                                                          "rule %u\n",
 554                                                          hook, pos);
 555                                         }
 556 #endif
 557                                         oldpos = pos;
 558                                         pos = e->counters.pcnt;
 559                                         e->counters.pcnt = 0;
 560
 561                                         /* We're at the start. */
 562                                         if (pos == oldpos)
 563                                                 goto next;
 564
 565                                         e = (struct ip6t_entry *)
 566                                                 (entry0 + pos);
 567                                 } while (oldpos == pos + e->next_offset);
 568
 569                                 /* Move along one */
 570                                 size = e->next_offset;
 571                                 e = (struct ip6t_entry *)
 572                                         (entry0 + pos + size);
 573                                 e->counters.pcnt = pos;
 574                                 pos += size;
 575                         } else {
 576                                 int newpos = t->verdict;
 577
 578                                 if (strcmp(t->target.u.user.name,
 579                                            IP6T_STANDARD_TARGET) == 0
 580                                     && newpos >= 0) {
 581                                         if (newpos > newinfo->size -
 582                                                 sizeof(struct ip6t_entry)) {
 583                                                 duprintf("mark_source_chains: "
 584                                                         "bad verdict (%i)\n",
 585                                                                 newpos);
 586                                                 return 0;
 587                                         }
 588                                         /* This a jump; chase it. */
 589                                         duprintf("Jump rule %u -> %u\n",
 590                                                  pos, newpos);
 591                                 } else {
 592                                         /* ... this is a fallthru */
 593                                         newpos = pos + e->next_offset;
 594                                 }
 595                                 e = (struct ip6t_entry *)
 596                                         (entry0 + newpos);
 597                                 e->counters.pcnt = pos;
 598                                 pos = newpos;
 599                         }
 600                 }
 601                 next:
 602                 duprintf("Finished chain %u\n", hook);
 603         }
 604         return 1;
 605 }
 606
 607 static inline int
 608 cleanup_match(struct ip6t_entry_match *m, unsigned int *i)
 609 {
 610         if (i && (*i)-- == 0)
 611                 return 1;
 612
 613         if (m->u.kernel.match->destroy)
 614                 m->u.kernel.match->destroy(m->u.kernel.match, m->data);
 615         module_put(m->u.kernel.match->me);
 616         return 0;
 617 }
 618
 619 static inline int
 620 check_match(struct ip6t_entry_match *m,
 621             const char *name,
 622             const struct ip6t_ip6 *ipv6,
 623             unsigned int hookmask,
 624             unsigned int *i)
 625 {
 626         struct xt_match *match;
 627         int ret;
 628
 629         match = try_then_request_module(xt_find_match(AF_INET6, m->u.user.name,
 630                                         m->u.user.revision),
 631                                         "ip6t_%s", m->u.user.name);
 632         if (IS_ERR(match) || !match) {
 633                 duprintf("check_match: `%s' not found\n", m->u.user.name);
 634                 return match ? PTR_ERR(match) : -ENOENT;
 635         }
 636         m->u.kernel.match = match;
 637
 638         ret = xt_check_match(match, AF_INET6, m->u.match_size - sizeof(*m),
 639                              name, hookmask, ipv6->proto,
 640                              ipv6->invflags & IP6T_INV_PROTO);
 641         if (ret)
 642                 goto err;
 643
 644         if (m->u.kernel.match->checkentry
 645             && !m->u.kernel.match->checkentry(name, ipv6, match,  m->data,
 646                                               hookmask)) {
 647                 duprintf("ip_tables: check failed for `%s'.\n",
 648                          m->u.kernel.match->name);
 649                 ret = -EINVAL;
 650                 goto err;
 651         }
 652
 653         (*i)++;
 654         return 0;
 655 err:
 656         module_put(m->u.kernel.match->me);
 657         return ret;
 658 }
 659
 660 static struct xt_target ip6t_standard_target;
 661
 662 static inline int
 663 check_entry(struct ip6t_entry *e, const char *name, unsigned int size,
 664             unsigned int *i)
 665 {
 666         struct ip6t_entry_target *t;
 667         struct xt_target *target;
 668         int ret;
 669         unsigned int j;
 670
 671         if (!ip6_checkentry(&e->ipv6)) {
 672                 duprintf("ip_tables: ip check failed %p %s.\n", e, name);
 673                 return -EINVAL;
 674         }
 675
 676         if (e->target_offset + sizeof(struct ip6t_entry_target) >
 677                                                                 e->next_offset)
 678                 return -EINVAL;
 679
 680         j = 0;
 681         ret = IP6T_MATCH_ITERATE(e, check_match, name, &e->ipv6, e->comefrom, &j);
 682         if (ret != 0)
 683                 goto cleanup_matches;
 684
 685         t = ip6t_get_target(e);
 686         ret = -EINVAL;
 687         if (e->target_offset + t->u.target_size > e->next_offset)
 688                         goto cleanup_matches;
 689         target = try_then_request_module(xt_find_target(AF_INET6,
 690                                                         t->u.user.name,
 691                                                         t->u.user.revision),
 692                                          "ip6t_%s", t->u.user.name);
 693         if (IS_ERR(target) || !target) {
 694                 duprintf("check_entry: `%s' not found\n", t->u.user.name);
 695                 ret = target ? PTR_ERR(target) : -ENOENT;
 696                 goto cleanup_matches;
 697         }
 698         t->u.kernel.target = target;
 699
 700         ret = xt_check_target(target, AF_INET6, t->u.target_size - sizeof(*t),
 701                               name, e->comefrom, e->ipv6.proto,
 702                               e->ipv6.invflags & IP6T_INV_PROTO);
 703         if (ret)
 704                 goto err;
 705
 706         if (t->u.kernel.target->checkentry
 707                    && !t->u.kernel.target->checkentry(name, e, target, t->data,
 708                                                       e->comefrom)) {
 709                 duprintf("ip_tables: check failed for `%s'.\n",
 710                          t->u.kernel.target->name);
 711                 ret = -EINVAL;
 712                 goto err;
 713         }
 714
 715         (*i)++;
 716         return 0;
 717  err:
 718         module_put(t->u.kernel.target->me);
 719  cleanup_matches:
 720         IP6T_MATCH_ITERATE(e, cleanup_match, &j);
 721         return ret;
 722 }
 723
 724 static inline int
 725 check_entry_size_and_hooks(struct ip6t_entry *e,
 726                            struct xt_table_info *newinfo,
 727                            unsigned char *base,
 728                            unsigned char *limit,
 729                            const unsigned int *hook_entries,
 730                            const unsigned int *underflows,
 731                            unsigned int *i)
 732 {
 733         unsigned int h;
 734
 735         if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0
 736             || (unsigned char *)e + sizeof(struct ip6t_entry) >= limit) {
 737                 duprintf("Bad offset %p\n", e);
 738                 return -EINVAL;
 739         }
 740
 741         if (e->next_offset
 742             < sizeof(struct ip6t_entry) + sizeof(struct ip6t_entry_target)) {
 743                 duprintf("checking: element %p size %u\n",
 744                          e, e->next_offset);
 745                 return -EINVAL;
 746         }
 747
 748         /* Check hooks & underflows */
 749         for (h = 0; h < NF_IP6_NUMHOOKS; h++) {
 750                 if ((unsigned char *)e - base == hook_entries[h])
 751                         newinfo->hook_entry[h] = hook_entries[h];
 752                 if ((unsigned char *)e - base == underflows[h])
 753                         newinfo->underflow[h] = underflows[h];
 754         }
 755
 756         /* FIXME: underflows must be unconditional, standard verdicts
 757            < 0 (not IP6T_RETURN). --RR */
 758
 759         /* Clear counters and comefrom */
 760         e->counters = ((struct xt_counters) { 0, 0 });
 761         e->comefrom = 0;
 762
 763         (*i)++;
 764         return 0;
 765 }
 766
 767 static inline int
 768 cleanup_entry(struct ip6t_entry *e, unsigned int *i)
 769 {
 770         struct ip6t_entry_target *t;
 771
 772         if (i && (*i)-- == 0)
 773                 return 1;
 774
 775         /* Cleanup all matches */
 776         IP6T_MATCH_ITERATE(e, cleanup_match, NULL);
 777         t = ip6t_get_target(e);
 778         if (t->u.kernel.target->destroy)
 779                 t->u.kernel.target->destroy(t->u.kernel.target, t->data);
 780         module_put(t->u.kernel.target->me);
 781         return 0;
 782 }
 783
 784 /* Checks and translates the user-supplied table segment (held in
 785    newinfo) */
 786 static int
 787 translate_table(const char *name,
 788                 unsigned int valid_hooks,
 789                 struct xt_table_info *newinfo,
 790                 void *entry0,
 791                 unsigned int size,
 792                 unsigned int number,
 793                 const unsigned int *hook_entries,
 794                 const unsigned int *underflows)
 795 {
 796         unsigned int i;
 797         int ret;
 798
 799         newinfo->size = size;
 800         newinfo->number = number;
 801
 802         /* Init all hooks to impossible value. */
 803         for (i = 0; i < NF_IP6_NUMHOOKS; i++) {
 804                 newinfo->hook_entry[i] = 0xFFFFFFFF;
 805                 newinfo->underflow[i] = 0xFFFFFFFF;
 806         }
 807
 808         duprintf("translate_table: size %u\n", newinfo->size);
 809         i = 0;
 810         /* Walk through entries, checking offsets. */
 811         ret = IP6T_ENTRY_ITERATE(entry0, newinfo->size,
 812                                 check_entry_size_and_hooks,
 813                                 newinfo,
 814                                 entry0,
 815                                 entry0 + size,
 816                                 hook_entries, underflows, &i);
 817         if (ret != 0)
 818                 return ret;
 819
 820         if (i != number) {
 821                 duprintf("translate_table: %u not %u entries\n",
 822                          i, number);
 823                 return -EINVAL;
 824         }
 825
 826         /* Check hooks all assigned */
 827         for (i = 0; i < NF_IP6_NUMHOOKS; i++) {
 828                 /* Only hooks which are valid */
 829                 if (!(valid_hooks & (1 << i)))
 830                         continue;
 831                 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
 832                         duprintf("Invalid hook entry %u %u\n",
 833                                  i, hook_entries[i]);
 834                         return -EINVAL;
 835                 }
 836                 if (newinfo->underflow[i] == 0xFFFFFFFF) {
 837                         duprintf("Invalid underflow %u %u\n",
 838                                  i, underflows[i]);
 839                         return -EINVAL;
 840                 }
 841         }
 842
 843         if (!mark_source_chains(newinfo, valid_hooks, entry0))
 844                 return -ELOOP;
 845
 846         /* Finally, each sanity check must pass */
 847         i = 0;
 848         ret = IP6T_ENTRY_ITERATE(entry0, newinfo->size,
 849                                 check_entry, name, size, &i);
 850
 851         if (ret != 0) {
 852                 IP6T_ENTRY_ITERATE(entry0, newinfo->size,
 853                                    cleanup_entry, &i);
 854                 return ret;
 855         }
 856
 857         /* And one copy for every other CPU */
 858         for_each_possible_cpu(i) {
 859                 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
 860                         memcpy(newinfo->entries[i], entry0, newinfo->size);
 861         }
 862
 863         return 0;
 864 }
 865
 866 /* Gets counters. */
 867 static inline int
 868 add_entry_to_counter(const struct ip6t_entry *e,
 869                      struct xt_counters total[],
 870                      unsigned int *i)
 871 {
 872         ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
 873
 874         (*i)++;
 875         return 0;
 876 }
 877
 878 static inline int
 879 set_entry_to_counter(const struct ip6t_entry *e,
 880                      struct ip6t_counters total[],
 881                      unsigned int *i)
 882 {
 883         SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
 884
 885         (*i)++;
 886         return 0;
 887 }
 888
 889 static void
 890 get_counters(const struct xt_table_info *t,
 891              struct xt_counters counters[])
 892 {
 893         unsigned int cpu;
 894         unsigned int i;
 895         unsigned int curcpu;
 896
 897         /* Instead of clearing (by a previous call to memset())
 898          * the counters and using adds, we set the counters
 899          * with data used by 'current' CPU
 900          * We dont care about preemption here.
 901          */
 902         curcpu = raw_smp_processor_id();
 903
 904         i = 0;
 905         IP6T_ENTRY_ITERATE(t->entries[curcpu],
 906                            t->size,
 907                            set_entry_to_counter,
 908                            counters,
 909                            &i);
 910
 911         for_each_possible_cpu(cpu) {
 912                 if (cpu == curcpu)
 913                         continue;
 914                 i = 0;
 915                 IP6T_ENTRY_ITERATE(t->entries[cpu],
 916                                   t->size,
 917                                   add_entry_to_counter,
 918                                   counters,
 919                                   &i);
 920         }
 921 }
 922
 923 static int
 924 copy_entries_to_user(unsigned int total_size,
 925                      struct xt_table *table,
 926                      void __user *userptr)
 927 {
 928         unsigned int off, num, countersize;
 929         struct ip6t_entry *e;
 930         struct xt_counters *counters;
 931         struct xt_table_info *private = table->private;
 932         int ret = 0;
 933         void *loc_cpu_entry;
 934
 935         /* We need atomic snapshot of counters: rest doesn't change
 936            (other than comefrom, which userspace doesn't care
 937            about). */
 938         countersize = sizeof(struct xt_counters) * private->number;
 939         counters = vmalloc(countersize);
 940
 941         if (counters == NULL)
 942                 return -ENOMEM;
 943
 944         /* First, sum counters... */
 945         write_lock_bh(&table->lock);
 946         get_counters(private, counters);
 947         write_unlock_bh(&table->lock);
 948
 949         /* choose the copy that is on ourc node/cpu */
 950         loc_cpu_entry = private->entries[raw_smp_processor_id()];
 951         if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
 952                 ret = -EFAULT;
 953                 goto free_counters;
 954         }
 955
 956         /* FIXME: use iterator macros --RR */
 957         /* ... then go back and fix counters and names */
 958         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
 959                 unsigned int i;
 960                 struct ip6t_entry_match *m;
 961                 struct ip6t_entry_target *t;
 962
 963                 e = (struct ip6t_entry *)(loc_cpu_entry + off);
 964                 if (copy_to_user(userptr + off
 965                                  + offsetof(struct ip6t_entry, counters),
 966                                  &counters[num],
 967                                  sizeof(counters[num])) != 0) {
 968                         ret = -EFAULT;
 969                         goto free_counters;
 970                 }
 971
 972                 for (i = sizeof(struct ip6t_entry);
 973                      i < e->target_offset;
 974                      i += m->u.match_size) {
 975                         m = (void *)e + i;
 976
 977                         if (copy_to_user(userptr + off + i
 978                                          + offsetof(struct ip6t_entry_match,
 979                                                     u.user.name),
 980                                          m->u.kernel.match->name,
 981                                          strlen(m->u.kernel.match->name)+1)
 982                             != 0) {
 983                                 ret = -EFAULT;
 984                                 goto free_counters;
 985                         }
 986                 }
 987
 988                 t = ip6t_get_target(e);
 989                 if (copy_to_user(userptr + off + e->target_offset
 990                                  + offsetof(struct ip6t_entry_target,
 991                                             u.user.name),
 992                                  t->u.kernel.target->name,
 993                                  strlen(t->u.kernel.target->name)+1) != 0) {
 994                         ret = -EFAULT;
 995                         goto free_counters;
 996                 }
 997         }
 998
 999  free_counters:
1000         vfree(counters);
1001         return ret;
1002 }
1003
1004 static int
1005 get_entries(const struct ip6t_get_entries *entries,
1006             struct ip6t_get_entries __user *uptr)
1007 {
1008         int ret;
1009         struct xt_table *t;
1010
1011         t = xt_find_table_lock(AF_INET6, entries->name);
1012         if (t && !IS_ERR(t)) {
1013                 struct xt_table_info *private = t->private;
1014                 duprintf("t->private->number = %u\n", private->number);
1015                 if (entries->size == private->size)
1016                         ret = copy_entries_to_user(private->size,
1017                                                    t, uptr->entrytable);
1018                 else {
1019                         duprintf("get_entries: I've got %u not %u!\n",
1020                                  private->size, entries->size);
1021                         ret = -EINVAL;
1022                 }
1023                 module_put(t->me);
1024                 xt_table_unlock(t);
1025         } else
1026                 ret = t ? PTR_ERR(t) : -ENOENT;
1027
1028         return ret;
1029 }
1030
1031 static int
1032 do_replace(void __user *user, unsigned int len)
1033 {
1034         int ret;
1035         struct ip6t_replace tmp;
1036         struct xt_table *t;
1037         struct xt_table_info *newinfo, *oldinfo;
1038         struct xt_counters *counters;
1039         void *loc_cpu_entry, *loc_cpu_old_entry;
1040
1041         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1042                 return -EFAULT;
1043
1044         /* overflow check */
1045         if (tmp.size >= (INT_MAX - sizeof(struct xt_table_info)) / NR_CPUS -
1046                         SMP_CACHE_BYTES)
1047                 return -ENOMEM;
1048         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1049                 return -ENOMEM;
1050
1051         newinfo = xt_alloc_table_info(tmp.size);
1052         if (!newinfo)
1053                 return -ENOMEM;
1054
1055         /* choose the copy that is on our node/cpu */
1056         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1057         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1058                            tmp.size) != 0) {
1059                 ret = -EFAULT;
1060                 goto free_newinfo;
1061         }
1062
1063         counters = vmalloc(tmp.num_counters * sizeof(struct xt_counters));
1064         if (!counters) {
1065                 ret = -ENOMEM;
1066                 goto free_newinfo;
1067         }
1068
1069         ret = translate_table(tmp.name, tmp.valid_hooks,
1070                               newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
1071                               tmp.hook_entry, tmp.underflow);
1072         if (ret != 0)
1073                 goto free_newinfo_counters;
1074
1075         duprintf("ip_tables: Translated table\n");
1076
1077         t = try_then_request_module(xt_find_table_lock(AF_INET6, tmp.name),
1078                                     "ip6table_%s", tmp.name);
1079         if (!t || IS_ERR(t)) {
1080                 ret = t ? PTR_ERR(t) : -ENOENT;
1081                 goto free_newinfo_counters_untrans;
1082         }
1083
1084         /* You lied! */
1085         if (tmp.valid_hooks != t->valid_hooks) {
1086                 duprintf("Valid hook crap: %08X vs %08X\n",
1087                          tmp.valid_hooks, t->valid_hooks);
1088                 ret = -EINVAL;
1089                 goto put_module;
1090         }
1091
1092         oldinfo = xt_replace_table(t, tmp.num_counters, newinfo, &ret);
1093         if (!oldinfo)
1094                 goto put_module;
1095
1096         /* Update module usage count based on number of rules */
1097         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1098                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1099         if ((oldinfo->number > oldinfo->initial_entries) ||
1100             (newinfo->number <= oldinfo->initial_entries))
1101                 module_put(t->me);
1102         if ((oldinfo->number > oldinfo->initial_entries) &&
1103             (newinfo->number <= oldinfo->initial_entries))
1104                 module_put(t->me);
1105
1106         /* Get the old counters. */
1107         get_counters(oldinfo, counters);
1108         /* Decrease module usage counts and free resource */
1109         loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1110         IP6T_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL);
1111         xt_free_table_info(oldinfo);
1112         if (copy_to_user(tmp.counters, counters,
1113                          sizeof(struct xt_counters) * tmp.num_counters) != 0)
1114                 ret = -EFAULT;
1115         vfree(counters);
1116         xt_table_unlock(t);
1117         return ret;
1118
1119  put_module:
1120         module_put(t->me);
1121         xt_table_unlock(t);
1122  free_newinfo_counters_untrans:
1123         IP6T_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
1124  free_newinfo_counters:
1125         vfree(counters);
1126  free_newinfo:
1127         xt_free_table_info(newinfo);
1128         return ret;
1129 }
1130
1131 /* We're lazy, and add to the first CPU; overflow works its fey magic
1132  * and everything is OK. */
1133 static inline int
1134 add_counter_to_entry(struct ip6t_entry *e,
1135                      const struct xt_counters addme[],
1136                      unsigned int *i)
1137 {
1138 #if 0
1139         duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n",
1140                  *i,
1141                  (long unsigned int)e->counters.pcnt,
1142                  (long unsigned int)e->counters.bcnt,
1143                  (long unsigned int)addme[*i].pcnt,
1144                  (long unsigned int)addme[*i].bcnt);
1145 #endif
1146
1147         ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
1148
1149         (*i)++;
1150         return 0;
1151 }
1152
1153 static int
1154 do_add_counters(void __user *user, unsigned int len)
1155 {
1156         unsigned int i;
1157         struct xt_counters_info tmp, *paddc;
1158         struct xt_table_info *private;
1159         struct xt_table *t;
1160         int ret = 0;
1161         void *loc_cpu_entry;
1162
1163         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1164                 return -EFAULT;
1165
1166         if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct xt_counters))
1167                 return -EINVAL;
1168
1169         paddc = vmalloc(len);
1170         if (!paddc)
1171                 return -ENOMEM;
1172
1173         if (copy_from_user(paddc, user, len) != 0) {
1174                 ret = -EFAULT;
1175                 goto free;
1176         }
1177
1178         t = xt_find_table_lock(AF_INET6, tmp.name);
1179         if (!t || IS_ERR(t)) {
1180                 ret = t ? PTR_ERR(t) : -ENOENT;
1181                 goto free;
1182         }
1183
1184         write_lock_bh(&t->lock);
1185         private = t->private;
1186         if (private->number != tmp.num_counters) {
1187                 ret = -EINVAL;
1188                 goto unlock_up_free;
1189         }
1190
1191         i = 0;
1192         /* Choose the copy that is on our node */
1193         loc_cpu_entry = private->entries[smp_processor_id()];
1194         IP6T_ENTRY_ITERATE(loc_cpu_entry,
1195                           private->size,
1196                           add_counter_to_entry,
1197                           paddc->counters,
1198                           &i);
1199  unlock_up_free:
1200         write_unlock_bh(&t->lock);
1201         xt_table_unlock(t);
1202         module_put(t->me);
1203  free:
1204         vfree(paddc);
1205
1206         return ret;
1207 }
1208
1209 static int
1210 do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1211 {
1212         int ret;
1213
1214         if (!capable(CAP_NET_ADMIN))
1215                 return -EPERM;
1216
1217         switch (cmd) {
1218         case IP6T_SO_SET_REPLACE:
1219                 ret = do_replace(user, len);
1220                 break;
1221
1222         case IP6T_SO_SET_ADD_COUNTERS:
1223                 ret = do_add_counters(user, len);
1224                 break;
1225
1226         default:
1227                 duprintf("do_ip6t_set_ctl:  unknown request %i\n", cmd);
1228                 ret = -EINVAL;
1229         }
1230
1231         return ret;
1232 }
1233
1234 static int
1235 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1236 {
1237         int ret;
1238
1239         if (!capable(CAP_NET_ADMIN))
1240                 return -EPERM;
1241
1242         switch (cmd) {
1243         case IP6T_SO_GET_INFO: {
1244                 char name[IP6T_TABLE_MAXNAMELEN];
1245                 struct xt_table *t;
1246
1247                 if (*len != sizeof(struct ip6t_getinfo)) {
1248                         duprintf("length %u != %u\n", *len,
1249                                  sizeof(struct ip6t_getinfo));
1250                         ret = -EINVAL;
1251                         break;
1252                 }
1253
1254                 if (copy_from_user(name, user, sizeof(name)) != 0) {
1255                         ret = -EFAULT;
1256                         break;
1257                 }
1258                 name[IP6T_TABLE_MAXNAMELEN-1] = '\0';
1259
1260                 t = try_then_request_module(xt_find_table_lock(AF_INET6, name),
1261                                             "ip6table_%s", name);
1262                 if (t && !IS_ERR(t)) {
1263                         struct ip6t_getinfo info;
1264                         struct xt_table_info *private = t->private;
1265
1266                         info.valid_hooks = t->valid_hooks;
1267                         memcpy(info.hook_entry, private->hook_entry,
1268                                sizeof(info.hook_entry));
1269                         memcpy(info.underflow, private->underflow,
1270                                sizeof(info.underflow));
1271                         info.num_entries = private->number;
1272                         info.size = private->size;
1273                         memcpy(info.name, name, sizeof(info.name));
1274
1275                         if (copy_to_user(user, &info, *len) != 0)
1276                                 ret = -EFAULT;
1277                         else
1278                                 ret = 0;
1279                         xt_table_unlock(t);
1280                         module_put(t->me);
1281                 } else
1282                         ret = t ? PTR_ERR(t) : -ENOENT;
1283         }
1284         break;
1285
1286         case IP6T_SO_GET_ENTRIES: {
1287                 struct ip6t_get_entries get;
1288
1289                 if (*len < sizeof(get)) {
1290                         duprintf("get_entries: %u < %u\n", *len, sizeof(get));
1291                         ret = -EINVAL;
1292                 } else if (copy_from_user(&get, user, sizeof(get)) != 0) {
1293                         ret = -EFAULT;
1294                 } else if (*len != sizeof(struct ip6t_get_entries) + get.size) {
1295                         duprintf("get_entries: %u != %u\n", *len,
1296                                  sizeof(struct ip6t_get_entries) + get.size);
1297                         ret = -EINVAL;
1298                 } else
1299                         ret = get_entries(&get, user);
1300                 break;
1301         }
1302
1303         case IP6T_SO_GET_REVISION_MATCH:
1304         case IP6T_SO_GET_REVISION_TARGET: {
1305                 struct ip6t_get_revision rev;
1306                 int target;
1307
1308                 if (*len != sizeof(rev)) {
1309                         ret = -EINVAL;
1310                         break;
1311                 }
1312                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1313                         ret = -EFAULT;
1314                         break;
1315                 }
1316
1317                 if (cmd == IP6T_SO_GET_REVISION_TARGET)
1318                         target = 1;
1319                 else
1320                         target = 0;
1321
1322                 try_then_request_module(xt_find_revision(AF_INET6, rev.name,
1323                                                          rev.revision,
1324                                                          target, &ret),
1325                                         "ip6t_%s", rev.name);
1326                 break;
1327         }
1328
1329         default:
1330                 duprintf("do_ip6t_get_ctl: unknown request %i\n", cmd);
1331                 ret = -EINVAL;
1332         }
1333
1334         return ret;
1335 }
1336
1337 int ip6t_register_table(struct xt_table *table,
1338                         const struct ip6t_replace *repl)
1339 {
1340         int ret;
1341         struct xt_table_info *newinfo;
1342         static struct xt_table_info bootstrap
1343                 = { 0, 0, 0, { 0 }, { 0 }, { } };
1344         void *loc_cpu_entry;
1345
1346         newinfo = xt_alloc_table_info(repl->size);
1347         if (!newinfo)
1348                 return -ENOMEM;
1349
1350         /* choose the copy on our node/cpu */
1351         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1352         memcpy(loc_cpu_entry, repl->entries, repl->size);
1353
1354         ret = translate_table(table->name, table->valid_hooks,
1355                               newinfo, loc_cpu_entry, repl->size,
1356                               repl->num_entries,
1357                               repl->hook_entry,
1358                               repl->underflow);
1359         if (ret != 0) {
1360                 xt_free_table_info(newinfo);
1361                 return ret;
1362         }
1363
1364         ret = xt_register_table(table, &bootstrap, newinfo);
1365         if (ret != 0) {
1366                 xt_free_table_info(newinfo);
1367                 return ret;
1368         }
1369
1370         return 0;
1371 }
1372
1373 void ip6t_unregister_table(struct xt_table *table)
1374 {
1375         struct xt_table_info *private;
1376         void *loc_cpu_entry;
1377
1378         private = xt_unregister_table(table);
1379
1380         /* Decrease module usage counts and free resources */
1381         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1382         IP6T_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, NULL);
1383         xt_free_table_info(private);
1384 }
1385
1386 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
1387 static inline bool
1388 icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
1389                      u_int8_t type, u_int8_t code,
1390                      bool invert)
1391 {
1392         return (type == test_type && code >= min_code && code <= max_code)
1393                 ^ invert;
1394 }
1395
1396 static bool
1397 icmp6_match(const struct sk_buff *skb,
1398            const struct net_device *in,
1399            const struct net_device *out,
1400            const struct xt_match *match,
1401            const void *matchinfo,
1402            int offset,
1403            unsigned int protoff,
1404            bool *hotdrop)
1405 {
1406         struct icmp6hdr _icmp, *ic;
1407         const struct ip6t_icmp *icmpinfo = matchinfo;
1408
1409         /* Must not be a fragment. */
1410         if (offset)
1411                 return false;
1412
1413         ic = skb_header_pointer(skb, protoff, sizeof(_icmp), &_icmp);
1414         if (ic == NULL) {
1415                 /* We've been asked to examine this packet, and we
1416                    can't.  Hence, no choice but to drop. */
1417                 duprintf("Dropping evil ICMP tinygram.\n");
1418                 *hotdrop = true;
1419                 return false;
1420         }
1421
1422         return icmp6_type_code_match(icmpinfo->type,
1423                                      icmpinfo->code[0],
1424                                      icmpinfo->code[1],
1425                                      ic->icmp6_type, ic->icmp6_code,
1426                                      !!(icmpinfo->invflags&IP6T_ICMP_INV));
1427 }
1428
1429 /* Called when user tries to insert an entry of this type. */
1430 static bool
1431 icmp6_checkentry(const char *tablename,
1432            const void *entry,
1433            const struct xt_match *match,
1434            void *matchinfo,
1435            unsigned int hook_mask)
1436 {
1437         const struct ip6t_icmp *icmpinfo = matchinfo;
1438
1439         /* Must specify no unknown invflags */
1440         return !(icmpinfo->invflags & ~IP6T_ICMP_INV);
1441 }
1442
1443 /* The built-in targets: standard (NULL) and error. */
1444 static struct xt_target ip6t_standard_target __read_mostly = {
1445         .name           = IP6T_STANDARD_TARGET,
1446         .targetsize     = sizeof(int),
1447         .family         = AF_INET6,
1448 };
1449
1450 static struct xt_target ip6t_error_target __read_mostly = {
1451         .name           = IP6T_ERROR_TARGET,
1452         .target         = ip6t_error,
1453         .targetsize     = IP6T_FUNCTION_MAXNAMELEN,
1454         .family         = AF_INET6,
1455 };
1456
1457 static struct nf_sockopt_ops ip6t_sockopts = {
1458         .pf             = PF_INET6,
1459         .set_optmin     = IP6T_BASE_CTL,
1460         .set_optmax     = IP6T_SO_SET_MAX+1,
1461         .set            = do_ip6t_set_ctl,
1462         .get_optmin     = IP6T_BASE_CTL,
1463         .get_optmax     = IP6T_SO_GET_MAX+1,
1464         .get            = do_ip6t_get_ctl,
1465 };
1466
1467 static struct xt_match icmp6_matchstruct __read_mostly = {
1468         .name           = "icmp6",
1469         .match          = &icmp6_match,
1470         .matchsize      = sizeof(struct ip6t_icmp),
1471         .checkentry     = icmp6_checkentry,
1472         .proto          = IPPROTO_ICMPV6,
1473         .family         = AF_INET6,
1474 };
1475
1476 static int __init ip6_tables_init(void)
1477 {
1478         int ret;
1479
1480         ret = xt_proto_init(AF_INET6);
1481         if (ret < 0)
1482                 goto err1;
1483
1484         /* Noone else will be downing sem now, so we won't sleep */
1485         ret = xt_register_target(&ip6t_standard_target);
1486         if (ret < 0)
1487                 goto err2;
1488         ret = xt_register_target(&ip6t_error_target);
1489         if (ret < 0)
1490                 goto err3;
1491         ret = xt_register_match(&icmp6_matchstruct);
1492         if (ret < 0)
1493                 goto err4;
1494
1495         /* Register setsockopt */
1496         ret = nf_register_sockopt(&ip6t_sockopts);
1497         if (ret < 0)
1498                 goto err5;
1499
1500         printk(KERN_INFO "ip6_tables: (C) 2000-2006 Netfilter Core Team\n");
1501         return 0;
1502
1503 err5:
1504         xt_unregister_match(&icmp6_matchstruct);
1505 err4:
1506         xt_unregister_target(&ip6t_error_target);
1507 err3:
1508         xt_unregister_target(&ip6t_standard_target);
1509 err2:
1510         xt_proto_fini(AF_INET6);
1511 err1:
1512         return ret;
1513 }
1514
1515 static void __exit ip6_tables_fini(void)
1516 {
1517         nf_unregister_sockopt(&ip6t_sockopts);
1518         xt_unregister_match(&icmp6_matchstruct);
1519         xt_unregister_target(&ip6t_error_target);
1520         xt_unregister_target(&ip6t_standard_target);
1521         xt_proto_fini(AF_INET6);
1522 }
1523
1524 /*
1525  * find the offset to specified header or the protocol number of last header
1526  * if target < 0. "last header" is transport protocol header, ESP, or
1527  * "No next header".
1528  *
1529  * If target header is found, its offset is set in *offset and return protocol
1530  * number. Otherwise, return -1.
1531  *
1532  * If the first fragment doesn't contain the final protocol header or
1533  * NEXTHDR_NONE it is considered invalid.
1534  *
1535  * Note that non-1st fragment is special case that "the protocol number
1536  * of last header" is "next header" field in Fragment header. In this case,
1537  * *offset is meaningless and fragment offset is stored in *fragoff if fragoff
1538  * isn't NULL.
1539  *
1540  */
1541 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
1542                   int target, unsigned short *fragoff)
1543 {
1544         unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
1545         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
1546         unsigned int len = skb->len - start;
1547
1548         if (fragoff)
1549                 *fragoff = 0;
1550
1551         while (nexthdr != target) {
1552                 struct ipv6_opt_hdr _hdr, *hp;
1553                 unsigned int hdrlen;
1554
1555                 if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {
1556                         if (target < 0)
1557                                 break;
1558                         return -ENOENT;
1559                 }
1560
1561                 hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
1562                 if (hp == NULL)
1563                         return -EBADMSG;
1564                 if (nexthdr == NEXTHDR_FRAGMENT) {
1565                         unsigned short _frag_off;
1566                         __be16 *fp;
1567                         fp = skb_header_pointer(skb,
1568                                                 start+offsetof(struct frag_hdr,
1569                                                                frag_off),
1570                                                 sizeof(_frag_off),
1571                                                 &_frag_off);
1572                         if (fp == NULL)
1573                                 return -EBADMSG;
1574
1575                         _frag_off = ntohs(*fp) & ~0x7;
1576                         if (_frag_off) {
1577                                 if (target < 0 &&
1578                                     ((!ipv6_ext_hdr(hp->nexthdr)) ||
1579                                      hp->nexthdr == NEXTHDR_NONE)) {
1580                                         if (fragoff)
1581                                                 *fragoff = _frag_off;
1582                                         return hp->nexthdr;
1583                                 }
1584                                 return -ENOENT;
1585                         }
1586                         hdrlen = 8;
1587                 } else if (nexthdr == NEXTHDR_AUTH)
1588                         hdrlen = (hp->hdrlen + 2) << 2;
1589                 else
1590                         hdrlen = ipv6_optlen(hp);
1591
1592                 nexthdr = hp->nexthdr;
1593                 len -= hdrlen;
1594                 start += hdrlen;
1595         }
1596
1597         *offset = start;
1598         return nexthdr;
1599 }
1600
1601 EXPORT_SYMBOL(ip6t_register_table);
1602 EXPORT_SYMBOL(ip6t_unregister_table);
1603 EXPORT_SYMBOL(ip6t_do_table);
1604 EXPORT_SYMBOL(ip6t_ext_hdr);
1605 EXPORT_SYMBOL(ipv6_find_hdr);
1606
1607 module_init(ip6_tables_init);
1608 module_exit(ip6_tables_fini);