ipv6/netfilter/ip6_tables.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Packet matching code.
   4  *
   5  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
   6  * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
   7  * Copyright (c) 2006-2010 Patrick McHardy <kaber@trash.net>
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/kernel.h>
  13 #include <linux/capability.h>
  14 #include <linux/in.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/kmod.h>
  17 #include <linux/vmalloc.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/module.h>
  20 #include <linux/poison.h>
  21 #include <net/ipv6.h>
  22 #include <net/compat.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/mutex.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/err.h>
  27 #include <linux/cpumask.h>
  28
  29 #include <linux/netfilter_ipv6/ip6_tables.h>
  30 #include <linux/netfilter/x_tables.h>
  31 #include <net/netfilter/nf_log.h>
  32 #include "../../netfilter/xt_repldata.h"
  33
  34 MODULE_LICENSE("GPL");
  35 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  36 MODULE_DESCRIPTION("IPv6 packet filter");
  37
  38 void *ip6t_alloc_initial_table(const struct xt_table *info)
  39 {
  40         return xt_alloc_initial_table(ip6t, IP6T);
  41 }
  42 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table);
  43
  44 /* Returns whether matches rule or not. */
  45 /* Performance critical - called for every packet */
  46 static inline bool
  47 ip6_packet_match(const struct sk_buff *skb,
  48                  const char *indev,
  49                  const char *outdev,
  50                  const struct ip6t_ip6 *ip6info,
  51                  unsigned int *protoff,
  52                  u16 *fragoff, bool *hotdrop)
  53 {
  54         unsigned long ret;
  55         const struct ipv6hdr *ipv6 = ipv6_hdr(skb);
  56
  57         if (NF_INVF(ip6info, IP6T_INV_SRCIP,
  58                     ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk,
  59                                          &ip6info->src)) ||
  60             NF_INVF(ip6info, IP6T_INV_DSTIP,
  61                     ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk,
  62                                          &ip6info->dst)))
  63                 return false;
  64
  65         ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask);
  66
  67         if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0))
  68                 return false;
  69
  70         ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask);
  71
  72         if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0))
  73                 return false;
  74
  75 /* ... might want to do something with class and flowlabel here ... */
  76
  77         /* look for the desired protocol header */
  78         if (ip6info->flags & IP6T_F_PROTO) {
  79                 int protohdr;
  80                 unsigned short _frag_off;
  81
  82                 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL);
  83                 if (protohdr < 0) {
  84                         if (_frag_off == 0)
  85                                 *hotdrop = true;
  86                         return false;
  87                 }
  88                 *fragoff = _frag_off;
  89
  90                 if (ip6info->proto == protohdr) {
  91                         if (ip6info->invflags & IP6T_INV_PROTO)
  92                                 return false;
  93
  94                         return true;
  95                 }
  96
  97                 /* We need match for the '-p all', too! */
  98                 if ((ip6info->proto != 0) &&
  99                         !(ip6info->invflags & IP6T_INV_PROTO))
 100                         return false;
 101         }
 102         return true;
 103 }
 104
 105 /* should be ip6 safe */
 106 static bool
 107 ip6_checkentry(const struct ip6t_ip6 *ipv6)
 108 {
 109         if (ipv6->flags & ~IP6T_F_MASK)
 110                 return false;
 111         if (ipv6->invflags & ~IP6T_INV_MASK)
 112                 return false;
 113
 114         return true;
 115 }
 116
 117 static unsigned int
 118 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par)
 119 {
 120         net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);
 121
 122         return NF_DROP;
 123 }
 124
 125 static inline struct ip6t_entry *
 126 get_entry(const void *base, unsigned int offset)
 127 {
 128         return (struct ip6t_entry *)(base + offset);
 129 }
 130
 131 /* All zeroes == unconditional rule. */
 132 /* Mildly perf critical (only if packet tracing is on) */
 133 static inline bool unconditional(const struct ip6t_entry *e)
 134 {
 135         static const struct ip6t_ip6 uncond;
 136
 137         return e->target_offset == sizeof(struct ip6t_entry) &&
 138                memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0;
 139 }
 140
 141 static inline const struct xt_entry_target *
 142 ip6t_get_target_c(const struct ip6t_entry *e)
 143 {
 144         return ip6t_get_target((struct ip6t_entry *)e);
 145 }
 146
 147 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
 148 /* This cries for unification! */
 149 static const char *const hooknames[] = {
 150         [NF_INET_PRE_ROUTING]           = "PREROUTING",
 151         [NF_INET_LOCAL_IN]              = "INPUT",
 152         [NF_INET_FORWARD]               = "FORWARD",
 153         [NF_INET_LOCAL_OUT]             = "OUTPUT",
 154         [NF_INET_POST_ROUTING]          = "POSTROUTING",
 155 };
 156
 157 enum nf_ip_trace_comments {
 158         NF_IP6_TRACE_COMMENT_RULE,
 159         NF_IP6_TRACE_COMMENT_RETURN,
 160         NF_IP6_TRACE_COMMENT_POLICY,
 161 };
 162
 163 static const char *const comments[] = {
 164         [NF_IP6_TRACE_COMMENT_RULE]     = "rule",
 165         [NF_IP6_TRACE_COMMENT_RETURN]   = "return",
 166         [NF_IP6_TRACE_COMMENT_POLICY]   = "policy",
 167 };
 168
 169 static const struct nf_loginfo trace_loginfo = {
 170         .type = NF_LOG_TYPE_LOG,
 171         .u = {
 172                 .log = {
 173                         .level = LOGLEVEL_WARNING,
 174                         .logflags = NF_LOG_DEFAULT_MASK,
 175                 },
 176         },
 177 };
 178
 179 /* Mildly perf critical (only if packet tracing is on) */
 180 static inline int
 181 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e,
 182                       const char *hookname, const char **chainname,
 183                       const char **comment, unsigned int *rulenum)
 184 {
 185         const struct xt_standard_target *t = (void *)ip6t_get_target_c(s);
 186
 187         if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
 188                 /* Head of user chain: ERROR target with chainname */
 189                 *chainname = t->target.data;
 190                 (*rulenum) = 0;
 191         } else if (s == e) {
 192                 (*rulenum)++;
 193
 194                 if (unconditional(s) &&
 195                     strcmp(t->target.u.kernel.target->name,
 196                            XT_STANDARD_TARGET) == 0 &&
 197                     t->verdict < 0) {
 198                         /* Tail of chains: STANDARD target (return/policy) */
 199                         *comment = *chainname == hookname
 200                                 ? comments[NF_IP6_TRACE_COMMENT_POLICY]
 201                                 : comments[NF_IP6_TRACE_COMMENT_RETURN];
 202                 }
 203                 return 1;
 204         } else
 205                 (*rulenum)++;
 206
 207         return 0;
 208 }
 209
 210 static void trace_packet(struct net *net,
 211                          const struct sk_buff *skb,
 212                          unsigned int hook,
 213                          const struct net_device *in,
 214                          const struct net_device *out,
 215                          const char *tablename,
 216                          const struct xt_table_info *private,
 217                          const struct ip6t_entry *e)
 218 {
 219         const struct ip6t_entry *root;
 220         const char *hookname, *chainname, *comment;
 221         const struct ip6t_entry *iter;
 222         unsigned int rulenum = 0;
 223
 224         root = get_entry(private->entries, private->hook_entry[hook]);
 225
 226         hookname = chainname = hooknames[hook];
 227         comment = comments[NF_IP6_TRACE_COMMENT_RULE];
 228
 229         xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
 230                 if (get_chainname_rulenum(iter, e, hookname,
 231                     &chainname, &comment, &rulenum) != 0)
 232                         break;
 233
 234         nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
 235                      "TRACE: %s:%s:%s:%u ",
 236                      tablename, chainname, comment, rulenum);
 237 }
 238 #endif
 239
 240 static inline struct ip6t_entry *
 241 ip6t_next_entry(const struct ip6t_entry *entry)
 242 {
 243         return (void *)entry + entry->next_offset;
 244 }
 245
 246 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
 247 unsigned int
 248 ip6t_do_table(void *priv, struct sk_buff *skb,
 249               const struct nf_hook_state *state)
 250 {
 251         const struct xt_table *table = priv;
 252         unsigned int hook = state->hook;
 253         static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
 254         /* Initializing verdict to NF_DROP keeps gcc happy. */
 255         unsigned int verdict = NF_DROP;
 256         const char *indev, *outdev;
 257         const void *table_base;
 258         struct ip6t_entry *e, **jumpstack;
 259         unsigned int stackidx, cpu;
 260         const struct xt_table_info *private;
 261         struct xt_action_param acpar;
 262         unsigned int addend;
 263
 264         /* Initialization */
 265         stackidx = 0;
 266         indev = state->in ? state->in->name : nulldevname;
 267         outdev = state->out ? state->out->name : nulldevname;
 268         /* We handle fragments by dealing with the first fragment as
 269          * if it was a normal packet.  All other fragments are treated
 270          * normally, except that they will NEVER match rules that ask
 271          * things we don't know, ie. tcp syn flag or ports).  If the
 272          * rule is also a fragment-specific rule, non-fragments won't
 273          * match it. */
 274         acpar.fragoff = 0;
 275         acpar.hotdrop = false;
 276         acpar.state   = state;
 277
 278         WARN_ON(!(table->valid_hooks & (1 << hook)));
 279
 280         local_bh_disable();
 281         addend = xt_write_recseq_begin();
 282         private = READ_ONCE(table->private); /* Address dependency. */
 283         cpu        = smp_processor_id();
 284         table_base = private->entries;
 285         jumpstack  = (struct ip6t_entry **)private->jumpstack[cpu];
 286
 287         /* Switch to alternate jumpstack if we're being invoked via TEE.
 288          * TEE issues XT_CONTINUE verdict on original skb so we must not
 289          * clobber the jumpstack.
 290          *
 291          * For recursion via REJECT or SYNPROXY the stack will be clobbered
 292          * but it is no problem since absolute verdict is issued by these.
 293          */
 294         if (static_key_false(&xt_tee_enabled))
 295                 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
 296
 297         e = get_entry(table_base, private->hook_entry[hook]);
 298
 299         do {
 300                 const struct xt_entry_target *t;
 301                 const struct xt_entry_match *ematch;
 302                 struct xt_counters *counter;
 303
 304                 WARN_ON(!e);
 305                 acpar.thoff = 0;
 306                 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6,
 307                     &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) {
 308  no_match:
 309                         e = ip6t_next_entry(e);
 310                         continue;
 311                 }
 312
 313                 xt_ematch_foreach(ematch, e) {
 314                         acpar.match     = ematch->u.kernel.match;
 315                         acpar.matchinfo = ematch->data;
 316                         if (!acpar.match->match(skb, &acpar))
 317                                 goto no_match;
 318                 }
 319
 320                 counter = xt_get_this_cpu_counter(&e->counters);
 321                 ADD_COUNTER(*counter, skb->len, 1);
 322
 323                 t = ip6t_get_target_c(e);
 324                 WARN_ON(!t->u.kernel.target);
 325
 326 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
 327                 /* The packet is traced: log it */
 328                 if (unlikely(skb->nf_trace))
 329                         trace_packet(state->net, skb, hook, state->in,
 330                                      state->out, table->name, private, e);
 331 #endif
 332                 /* Standard target? */
 333                 if (!t->u.kernel.target->target) {
 334                         int v;
 335
 336                         v = ((struct xt_standard_target *)t)->verdict;
 337                         if (v < 0) {
 338                                 /* Pop from stack? */
 339                                 if (v != XT_RETURN) {
 340                                         verdict = (unsigned int)(-v) - 1;
 341                                         break;
 342                                 }
 343                                 if (stackidx == 0)
 344                                         e = get_entry(table_base,
 345                                             private->underflow[hook]);
 346                                 else
 347                                         e = ip6t_next_entry(jumpstack[--stackidx]);
 348                                 continue;
 349                         }
 350                         if (table_base + v != ip6t_next_entry(e) &&
 351                             !(e->ipv6.flags & IP6T_F_GOTO)) {
 352                                 if (unlikely(stackidx >= private->stacksize)) {
 353                                         verdict = NF_DROP;
 354                                         break;
 355                                 }
 356                                 jumpstack[stackidx++] = e;
 357                         }
 358
 359                         e = get_entry(table_base, v);
 360                         continue;
 361                 }
 362
 363                 acpar.target   = t->u.kernel.target;
 364                 acpar.targinfo = t->data;
 365
 366                 verdict = t->u.kernel.target->target(skb, &acpar);
 367                 if (verdict == XT_CONTINUE)
 368                         e = ip6t_next_entry(e);
 369                 else
 370                         /* Verdict */
 371                         break;
 372         } while (!acpar.hotdrop);
 373
 374         xt_write_recseq_end(addend);
 375         local_bh_enable();
 376
 377         if (acpar.hotdrop)
 378                 return NF_DROP;
 379         else return verdict;
 380 }
 381
 382 /* Figures out from what hook each rule can be called: returns 0 if
 383    there are loops.  Puts hook bitmask in comefrom. */
 384 static int
 385 mark_source_chains(const struct xt_table_info *newinfo,
 386                    unsigned int valid_hooks, void *entry0,
 387                    unsigned int *offsets)
 388 {
 389         unsigned int hook;
 390
 391         /* No recursion; use packet counter to save back ptrs (reset
 392            to 0 as we leave), and comefrom to save source hook bitmask */
 393         for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
 394                 unsigned int pos = newinfo->hook_entry[hook];
 395                 struct ip6t_entry *e = entry0 + pos;
 396
 397                 if (!(valid_hooks & (1 << hook)))
 398                         continue;
 399
 400                 /* Set initial back pointer. */
 401                 e->counters.pcnt = pos;
 402
 403                 for (;;) {
 404                         const struct xt_standard_target *t
 405                                 = (void *)ip6t_get_target_c(e);
 406                         int visited = e->comefrom & (1 << hook);
 407
 408                         if (e->comefrom & (1 << NF_INET_NUMHOOKS))
 409                                 return 0;
 410
 411                         e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
 412
 413                         /* Unconditional return/END. */
 414                         if ((unconditional(e) &&
 415                              (strcmp(t->target.u.user.name,
 416                                      XT_STANDARD_TARGET) == 0) &&
 417                              t->verdict < 0) || visited) {
 418                                 unsigned int oldpos, size;
 419
 420                                 /* Return: backtrack through the last
 421                                    big jump. */
 422                                 do {
 423                                         e->comefrom ^= (1<<NF_INET_NUMHOOKS);
 424                                         oldpos = pos;
 425                                         pos = e->counters.pcnt;
 426                                         e->counters.pcnt = 0;
 427
 428                                         /* We're at the start. */
 429                                         if (pos == oldpos)
 430                                                 goto next;
 431
 432                                         e = entry0 + pos;
 433                                 } while (oldpos == pos + e->next_offset);
 434
 435                                 /* Move along one */
 436                                 size = e->next_offset;
 437                                 e = entry0 + pos + size;
 438                                 if (pos + size >= newinfo->size)
 439                                         return 0;
 440                                 e->counters.pcnt = pos;
 441                                 pos += size;
 442                         } else {
 443                                 int newpos = t->verdict;
 444
 445                                 if (strcmp(t->target.u.user.name,
 446                                            XT_STANDARD_TARGET) == 0 &&
 447                                     newpos >= 0) {
 448                                         /* This a jump; chase it. */
 449                                         if (!xt_find_jump_offset(offsets, newpos,
 450                                                                  newinfo->number))
 451                                                 return 0;
 452                                 } else {
 453                                         /* ... this is a fallthru */
 454                                         newpos = pos + e->next_offset;
 455                                         if (newpos >= newinfo->size)
 456                                                 return 0;
 457                                 }
 458                                 e = entry0 + newpos;
 459                                 e->counters.pcnt = pos;
 460                                 pos = newpos;
 461                         }
 462                 }
 463 next:           ;
 464         }
 465         return 1;
 466 }
 467
 468 static void cleanup_match(struct xt_entry_match *m, struct net *net)
 469 {
 470         struct xt_mtdtor_param par;
 471
 472         par.net       = net;
 473         par.match     = m->u.kernel.match;
 474         par.matchinfo = m->data;
 475         par.family    = NFPROTO_IPV6;
 476         if (par.match->destroy != NULL)
 477                 par.match->destroy(&par);
 478         module_put(par.match->me);
 479 }
 480
 481 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
 482 {
 483         const struct ip6t_ip6 *ipv6 = par->entryinfo;
 484
 485         par->match     = m->u.kernel.match;
 486         par->matchinfo = m->data;
 487
 488         return xt_check_match(par, m->u.match_size - sizeof(*m),
 489                               ipv6->proto, ipv6->invflags & IP6T_INV_PROTO);
 490 }
 491
 492 static int
 493 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
 494 {
 495         struct xt_match *match;
 496         int ret;
 497
 498         match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
 499                                       m->u.user.revision);
 500         if (IS_ERR(match))
 501                 return PTR_ERR(match);
 502
 503         m->u.kernel.match = match;
 504
 505         ret = check_match(m, par);
 506         if (ret)
 507                 goto err;
 508
 509         return 0;
 510 err:
 511         module_put(m->u.kernel.match->me);
 512         return ret;
 513 }
 514
 515 static int check_target(struct ip6t_entry *e, struct net *net, const char *name)
 516 {
 517         struct xt_entry_target *t = ip6t_get_target(e);
 518         struct xt_tgchk_param par = {
 519                 .net       = net,
 520                 .table     = name,
 521                 .entryinfo = e,
 522                 .target    = t->u.kernel.target,
 523                 .targinfo  = t->data,
 524                 .hook_mask = e->comefrom,
 525                 .family    = NFPROTO_IPV6,
 526         };
 527
 528         return xt_check_target(&par, t->u.target_size - sizeof(*t),
 529                                e->ipv6.proto,
 530                                e->ipv6.invflags & IP6T_INV_PROTO);
 531 }
 532
 533 static int
 534 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
 535                  unsigned int size,
 536                  struct xt_percpu_counter_alloc_state *alloc_state)
 537 {
 538         struct xt_entry_target *t;
 539         struct xt_target *target;
 540         int ret;
 541         unsigned int j;
 542         struct xt_mtchk_param mtpar;
 543         struct xt_entry_match *ematch;
 544
 545         if (!xt_percpu_counter_alloc(alloc_state, &e->counters))
 546                 return -ENOMEM;
 547
 548         j = 0;
 549         memset(&mtpar, 0, sizeof(mtpar));
 550         mtpar.net       = net;
 551         mtpar.table     = name;
 552         mtpar.entryinfo = &e->ipv6;
 553         mtpar.hook_mask = e->comefrom;
 554         mtpar.family    = NFPROTO_IPV6;
 555         xt_ematch_foreach(ematch, e) {
 556                 ret = find_check_match(ematch, &mtpar);
 557                 if (ret != 0)
 558                         goto cleanup_matches;
 559                 ++j;
 560         }
 561
 562         t = ip6t_get_target(e);
 563         target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
 564                                         t->u.user.revision);
 565         if (IS_ERR(target)) {
 566                 ret = PTR_ERR(target);
 567                 goto cleanup_matches;
 568         }
 569         t->u.kernel.target = target;
 570
 571         ret = check_target(e, net, name);
 572         if (ret)
 573                 goto err;
 574         return 0;
 575  err:
 576         module_put(t->u.kernel.target->me);
 577  cleanup_matches:
 578         xt_ematch_foreach(ematch, e) {
 579                 if (j-- == 0)
 580                         break;
 581                 cleanup_match(ematch, net);
 582         }
 583
 584         xt_percpu_counter_free(&e->counters);
 585
 586         return ret;
 587 }
 588
 589 static bool check_underflow(const struct ip6t_entry *e)
 590 {
 591         const struct xt_entry_target *t;
 592         unsigned int verdict;
 593
 594         if (!unconditional(e))
 595                 return false;
 596         t = ip6t_get_target_c(e);
 597         if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
 598                 return false;
 599         verdict = ((struct xt_standard_target *)t)->verdict;
 600         verdict = -verdict - 1;
 601         return verdict == NF_DROP || verdict == NF_ACCEPT;
 602 }
 603
 604 static int
 605 check_entry_size_and_hooks(struct ip6t_entry *e,
 606                            struct xt_table_info *newinfo,
 607                            const unsigned char *base,
 608                            const unsigned char *limit,
 609                            const unsigned int *hook_entries,
 610                            const unsigned int *underflows,
 611                            unsigned int valid_hooks)
 612 {
 613         unsigned int h;
 614         int err;
 615
 616         if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 ||
 617             (unsigned char *)e + sizeof(struct ip6t_entry) >= limit ||
 618             (unsigned char *)e + e->next_offset > limit)
 619                 return -EINVAL;
 620
 621         if (e->next_offset
 622             < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target))
 623                 return -EINVAL;
 624
 625         if (!ip6_checkentry(&e->ipv6))
 626                 return -EINVAL;
 627
 628         err = xt_check_entry_offsets(e, e->elems, e->target_offset,
 629                                      e->next_offset);
 630         if (err)
 631                 return err;
 632
 633         /* Check hooks & underflows */
 634         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
 635                 if (!(valid_hooks & (1 << h)))
 636                         continue;
 637                 if ((unsigned char *)e - base == hook_entries[h])
 638                         newinfo->hook_entry[h] = hook_entries[h];
 639                 if ((unsigned char *)e - base == underflows[h]) {
 640                         if (!check_underflow(e))
 641                                 return -EINVAL;
 642
 643                         newinfo->underflow[h] = underflows[h];
 644                 }
 645         }
 646
 647         /* Clear counters and comefrom */
 648         e->counters = ((struct xt_counters) { 0, 0 });
 649         e->comefrom = 0;
 650         return 0;
 651 }
 652
 653 static void cleanup_entry(struct ip6t_entry *e, struct net *net)
 654 {
 655         struct xt_tgdtor_param par;
 656         struct xt_entry_target *t;
 657         struct xt_entry_match *ematch;
 658
 659         /* Cleanup all matches */
 660         xt_ematch_foreach(ematch, e)
 661                 cleanup_match(ematch, net);
 662         t = ip6t_get_target(e);
 663
 664         par.net      = net;
 665         par.target   = t->u.kernel.target;
 666         par.targinfo = t->data;
 667         par.family   = NFPROTO_IPV6;
 668         if (par.target->destroy != NULL)
 669                 par.target->destroy(&par);
 670         module_put(par.target->me);
 671         xt_percpu_counter_free(&e->counters);
 672 }
 673
 674 /* Checks and translates the user-supplied table segment (held in
 675    newinfo) */
 676 static int
 677 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
 678                 const struct ip6t_replace *repl)
 679 {
 680         struct xt_percpu_counter_alloc_state alloc_state = { 0 };
 681         struct ip6t_entry *iter;
 682         unsigned int *offsets;
 683         unsigned int i;
 684         int ret = 0;
 685
 686         newinfo->size = repl->size;
 687         newinfo->number = repl->num_entries;
 688
 689         /* Init all hooks to impossible value. */
 690         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 691                 newinfo->hook_entry[i] = 0xFFFFFFFF;
 692                 newinfo->underflow[i] = 0xFFFFFFFF;
 693         }
 694
 695         offsets = xt_alloc_entry_offsets(newinfo->number);
 696         if (!offsets)
 697                 return -ENOMEM;
 698         i = 0;
 699         /* Walk through entries, checking offsets. */
 700         xt_entry_foreach(iter, entry0, newinfo->size) {
 701                 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
 702                                                  entry0 + repl->size,
 703                                                  repl->hook_entry,
 704                                                  repl->underflow,
 705                                                  repl->valid_hooks);
 706                 if (ret != 0)
 707                         goto out_free;
 708                 if (i < repl->num_entries)
 709                         offsets[i] = (void *)iter - entry0;
 710                 ++i;
 711                 if (strcmp(ip6t_get_target(iter)->u.user.name,
 712                     XT_ERROR_TARGET) == 0)
 713                         ++newinfo->stacksize;
 714         }
 715
 716         ret = -EINVAL;
 717         if (i != repl->num_entries)
 718                 goto out_free;
 719
 720         ret = xt_check_table_hooks(newinfo, repl->valid_hooks);
 721         if (ret)
 722                 goto out_free;
 723
 724         if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) {
 725                 ret = -ELOOP;
 726                 goto out_free;
 727         }
 728         kvfree(offsets);
 729
 730         /* Finally, each sanity check must pass */
 731         i = 0;
 732         xt_entry_foreach(iter, entry0, newinfo->size) {
 733                 ret = find_check_entry(iter, net, repl->name, repl->size,
 734                                        &alloc_state);
 735                 if (ret != 0)
 736                         break;
 737                 ++i;
 738         }
 739
 740         if (ret != 0) {
 741                 xt_entry_foreach(iter, entry0, newinfo->size) {
 742                         if (i-- == 0)
 743                                 break;
 744                         cleanup_entry(iter, net);
 745                 }
 746                 return ret;
 747         }
 748
 749         return ret;
 750  out_free:
 751         kvfree(offsets);
 752         return ret;
 753 }
 754
 755 static void
 756 get_counters(const struct xt_table_info *t,
 757              struct xt_counters counters[])
 758 {
 759         struct ip6t_entry *iter;
 760         unsigned int cpu;
 761         unsigned int i;
 762
 763         for_each_possible_cpu(cpu) {
 764                 seqcount_t *s = &per_cpu(xt_recseq, cpu);
 765
 766                 i = 0;
 767                 xt_entry_foreach(iter, t->entries, t->size) {
 768                         struct xt_counters *tmp;
 769                         u64 bcnt, pcnt;
 770                         unsigned int start;
 771
 772                         tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
 773                         do {
 774                                 start = read_seqcount_begin(s);
 775                                 bcnt = tmp->bcnt;
 776                                 pcnt = tmp->pcnt;
 777                         } while (read_seqcount_retry(s, start));
 778
 779                         ADD_COUNTER(counters[i], bcnt, pcnt);
 780                         ++i;
 781                         cond_resched();
 782                 }
 783         }
 784 }
 785
 786 static void get_old_counters(const struct xt_table_info *t,
 787                              struct xt_counters counters[])
 788 {
 789         struct ip6t_entry *iter;
 790         unsigned int cpu, i;
 791
 792         for_each_possible_cpu(cpu) {
 793                 i = 0;
 794                 xt_entry_foreach(iter, t->entries, t->size) {
 795                         const struct xt_counters *tmp;
 796
 797                         tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
 798                         ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt);
 799                         ++i;
 800                 }
 801                 cond_resched();
 802         }
 803 }
 804
 805 static struct xt_counters *alloc_counters(const struct xt_table *table)
 806 {
 807         unsigned int countersize;
 808         struct xt_counters *counters;
 809         const struct xt_table_info *private = table->private;
 810
 811         /* We need atomic snapshot of counters: rest doesn't change
 812            (other than comefrom, which userspace doesn't care
 813            about). */
 814         countersize = sizeof(struct xt_counters) * private->number;
 815         counters = vzalloc(countersize);
 816
 817         if (counters == NULL)
 818                 return ERR_PTR(-ENOMEM);
 819
 820         get_counters(private, counters);
 821
 822         return counters;
 823 }
 824
 825 static int
 826 copy_entries_to_user(unsigned int total_size,
 827                      const struct xt_table *table,
 828                      void __user *userptr)
 829 {
 830         unsigned int off, num;
 831         const struct ip6t_entry *e;
 832         struct xt_counters *counters;
 833         const struct xt_table_info *private = table->private;
 834         int ret = 0;
 835         const void *loc_cpu_entry;
 836
 837         counters = alloc_counters(table);
 838         if (IS_ERR(counters))
 839                 return PTR_ERR(counters);
 840
 841         loc_cpu_entry = private->entries;
 842
 843         /* FIXME: use iterator macros --RR */
 844         /* ... then go back and fix counters and names */
 845         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
 846                 unsigned int i;
 847                 const struct xt_entry_match *m;
 848                 const struct xt_entry_target *t;
 849
 850                 e = loc_cpu_entry + off;
 851                 if (copy_to_user(userptr + off, e, sizeof(*e))) {
 852                         ret = -EFAULT;
 853                         goto free_counters;
 854                 }
 855                 if (copy_to_user(userptr + off
 856                                  + offsetof(struct ip6t_entry, counters),
 857                                  &counters[num],
 858                                  sizeof(counters[num])) != 0) {
 859                         ret = -EFAULT;
 860                         goto free_counters;
 861                 }
 862
 863                 for (i = sizeof(struct ip6t_entry);
 864                      i < e->target_offset;
 865                      i += m->u.match_size) {
 866                         m = (void *)e + i;
 867
 868                         if (xt_match_to_user(m, userptr + off + i)) {
 869                                 ret = -EFAULT;
 870                                 goto free_counters;
 871                         }
 872                 }
 873
 874                 t = ip6t_get_target_c(e);
 875                 if (xt_target_to_user(t, userptr + off + e->target_offset)) {
 876                         ret = -EFAULT;
 877                         goto free_counters;
 878                 }
 879         }
 880
 881  free_counters:
 882         vfree(counters);
 883         return ret;
 884 }
 885
 886 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 887 static void compat_standard_from_user(void *dst, const void *src)
 888 {
 889         int v = *(compat_int_t *)src;
 890
 891         if (v > 0)
 892                 v += xt_compat_calc_jump(AF_INET6, v);
 893         memcpy(dst, &v, sizeof(v));
 894 }
 895
 896 static int compat_standard_to_user(void __user *dst, const void *src)
 897 {
 898         compat_int_t cv = *(int *)src;
 899
 900         if (cv > 0)
 901                 cv -= xt_compat_calc_jump(AF_INET6, cv);
 902         return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
 903 }
 904
 905 static int compat_calc_entry(const struct ip6t_entry *e,
 906                              const struct xt_table_info *info,
 907                              const void *base, struct xt_table_info *newinfo)
 908 {
 909         const struct xt_entry_match *ematch;
 910         const struct xt_entry_target *t;
 911         unsigned int entry_offset;
 912         int off, i, ret;
 913
 914         off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
 915         entry_offset = (void *)e - base;
 916         xt_ematch_foreach(ematch, e)
 917                 off += xt_compat_match_offset(ematch->u.kernel.match);
 918         t = ip6t_get_target_c(e);
 919         off += xt_compat_target_offset(t->u.kernel.target);
 920         newinfo->size -= off;
 921         ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
 922         if (ret)
 923                 return ret;
 924
 925         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 926                 if (info->hook_entry[i] &&
 927                     (e < (struct ip6t_entry *)(base + info->hook_entry[i])))
 928                         newinfo->hook_entry[i] -= off;
 929                 if (info->underflow[i] &&
 930                     (e < (struct ip6t_entry *)(base + info->underflow[i])))
 931                         newinfo->underflow[i] -= off;
 932         }
 933         return 0;
 934 }
 935
 936 static int compat_table_info(const struct xt_table_info *info,
 937                              struct xt_table_info *newinfo)
 938 {
 939         struct ip6t_entry *iter;
 940         const void *loc_cpu_entry;
 941         int ret;
 942
 943         if (!newinfo || !info)
 944                 return -EINVAL;
 945
 946         /* we dont care about newinfo->entries */
 947         memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
 948         newinfo->initial_entries = 0;
 949         loc_cpu_entry = info->entries;
 950         ret = xt_compat_init_offsets(AF_INET6, info->number);
 951         if (ret)
 952                 return ret;
 953         xt_entry_foreach(iter, loc_cpu_entry, info->size) {
 954                 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
 955                 if (ret != 0)
 956                         return ret;
 957         }
 958         return 0;
 959 }
 960 #endif
 961
 962 static int get_info(struct net *net, void __user *user, const int *len)
 963 {
 964         char name[XT_TABLE_MAXNAMELEN];
 965         struct xt_table *t;
 966         int ret;
 967
 968         if (*len != sizeof(struct ip6t_getinfo))
 969                 return -EINVAL;
 970
 971         if (copy_from_user(name, user, sizeof(name)) != 0)
 972                 return -EFAULT;
 973
 974         name[XT_TABLE_MAXNAMELEN-1] = '\0';
 975 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 976         if (in_compat_syscall())
 977                 xt_compat_lock(AF_INET6);
 978 #endif
 979         t = xt_request_find_table_lock(net, AF_INET6, name);
 980         if (!IS_ERR(t)) {
 981                 struct ip6t_getinfo info;
 982                 const struct xt_table_info *private = t->private;
 983 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 984                 struct xt_table_info tmp;
 985
 986                 if (in_compat_syscall()) {
 987                         ret = compat_table_info(private, &tmp);
 988                         xt_compat_flush_offsets(AF_INET6);
 989                         private = &tmp;
 990                 }
 991 #endif
 992                 memset(&info, 0, sizeof(info));
 993                 info.valid_hooks = t->valid_hooks;
 994                 memcpy(info.hook_entry, private->hook_entry,
 995                        sizeof(info.hook_entry));
 996                 memcpy(info.underflow, private->underflow,
 997                        sizeof(info.underflow));
 998                 info.num_entries = private->number;
 999                 info.size = private->size;
1000                 strcpy(info.name, name);
1001
1002                 if (copy_to_user(user, &info, *len) != 0)
1003                         ret = -EFAULT;
1004                 else
1005                         ret = 0;
1006
1007                 xt_table_unlock(t);
1008                 module_put(t->me);
1009         } else
1010                 ret = PTR_ERR(t);
1011 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1012         if (in_compat_syscall())
1013                 xt_compat_unlock(AF_INET6);
1014 #endif
1015         return ret;
1016 }
1017
1018 static int
1019 get_entries(struct net *net, struct ip6t_get_entries __user *uptr,
1020             const int *len)
1021 {
1022         int ret;
1023         struct ip6t_get_entries get;
1024         struct xt_table *t;
1025
1026         if (*len < sizeof(get))
1027                 return -EINVAL;
1028         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1029                 return -EFAULT;
1030         if (*len != sizeof(struct ip6t_get_entries) + get.size)
1031                 return -EINVAL;
1032
1033         get.name[sizeof(get.name) - 1] = '\0';
1034
1035         t = xt_find_table_lock(net, AF_INET6, get.name);
1036         if (!IS_ERR(t)) {
1037                 struct xt_table_info *private = t->private;
1038                 if (get.size == private->size)
1039                         ret = copy_entries_to_user(private->size,
1040                                                    t, uptr->entrytable);
1041                 else
1042                         ret = -EAGAIN;
1043
1044                 module_put(t->me);
1045                 xt_table_unlock(t);
1046         } else
1047                 ret = PTR_ERR(t);
1048
1049         return ret;
1050 }
1051
1052 static int
1053 __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1054              struct xt_table_info *newinfo, unsigned int num_counters,
1055              void __user *counters_ptr)
1056 {
1057         int ret;
1058         struct xt_table *t;
1059         struct xt_table_info *oldinfo;
1060         struct xt_counters *counters;
1061         struct ip6t_entry *iter;
1062
1063         counters = xt_counters_alloc(num_counters);
1064         if (!counters) {
1065                 ret = -ENOMEM;
1066                 goto out;
1067         }
1068
1069         t = xt_request_find_table_lock(net, AF_INET6, name);
1070         if (IS_ERR(t)) {
1071                 ret = PTR_ERR(t);
1072                 goto free_newinfo_counters_untrans;
1073         }
1074
1075         /* You lied! */
1076         if (valid_hooks != t->valid_hooks) {
1077                 ret = -EINVAL;
1078                 goto put_module;
1079         }
1080
1081         oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1082         if (!oldinfo)
1083                 goto put_module;
1084
1085         /* Update module usage count based on number of rules */
1086         if ((oldinfo->number > oldinfo->initial_entries) ||
1087             (newinfo->number <= oldinfo->initial_entries))
1088                 module_put(t->me);
1089         if ((oldinfo->number > oldinfo->initial_entries) &&
1090             (newinfo->number <= oldinfo->initial_entries))
1091                 module_put(t->me);
1092
1093         xt_table_unlock(t);
1094
1095         get_old_counters(oldinfo, counters);
1096
1097         /* Decrease module usage counts and free resource */
1098         xt_entry_foreach(iter, oldinfo->entries, oldinfo->size)
1099                 cleanup_entry(iter, net);
1100
1101         xt_free_table_info(oldinfo);
1102         if (copy_to_user(counters_ptr, counters,
1103                          sizeof(struct xt_counters) * num_counters) != 0) {
1104                 /* Silent error, can't fail, new table is already in place */
1105                 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n");
1106         }
1107         vfree(counters);
1108         return 0;
1109
1110  put_module:
1111         module_put(t->me);
1112         xt_table_unlock(t);
1113  free_newinfo_counters_untrans:
1114         vfree(counters);
1115  out:
1116         return ret;
1117 }
1118
1119 static int
1120 do_replace(struct net *net, sockptr_t arg, unsigned int len)
1121 {
1122         int ret;
1123         struct ip6t_replace tmp;
1124         struct xt_table_info *newinfo;
1125         void *loc_cpu_entry;
1126         struct ip6t_entry *iter;
1127
1128         if (len < sizeof(tmp))
1129                 return -EINVAL;
1130         if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
1131                 return -EFAULT;
1132
1133         /* overflow check */
1134         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1135                 return -ENOMEM;
1136         if (tmp.num_counters == 0)
1137                 return -EINVAL;
1138         if ((u64)len < (u64)tmp.size + sizeof(tmp))
1139                 return -EINVAL;
1140
1141         tmp.name[sizeof(tmp.name)-1] = 0;
1142
1143         newinfo = xt_alloc_table_info(tmp.size);
1144         if (!newinfo)
1145                 return -ENOMEM;
1146
1147         loc_cpu_entry = newinfo->entries;
1148         if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp),
1149                         tmp.size) != 0) {
1150                 ret = -EFAULT;
1151                 goto free_newinfo;
1152         }
1153
1154         ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
1155         if (ret != 0)
1156                 goto free_newinfo;
1157
1158         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1159                            tmp.num_counters, tmp.counters);
1160         if (ret)
1161                 goto free_newinfo_untrans;
1162         return 0;
1163
1164  free_newinfo_untrans:
1165         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1166                 cleanup_entry(iter, net);
1167  free_newinfo:
1168         xt_free_table_info(newinfo);
1169         return ret;
1170 }
1171
1172 static int
1173 do_add_counters(struct net *net, sockptr_t arg, unsigned int len)
1174 {
1175         unsigned int i;
1176         struct xt_counters_info tmp;
1177         struct xt_counters *paddc;
1178         struct xt_table *t;
1179         const struct xt_table_info *private;
1180         int ret = 0;
1181         struct ip6t_entry *iter;
1182         unsigned int addend;
1183
1184         paddc = xt_copy_counters(arg, len, &tmp);
1185         if (IS_ERR(paddc))
1186                 return PTR_ERR(paddc);
1187         t = xt_find_table_lock(net, AF_INET6, tmp.name);
1188         if (IS_ERR(t)) {
1189                 ret = PTR_ERR(t);
1190                 goto free;
1191         }
1192
1193         local_bh_disable();
1194         private = t->private;
1195         if (private->number != tmp.num_counters) {
1196                 ret = -EINVAL;
1197                 goto unlock_up_free;
1198         }
1199
1200         i = 0;
1201         addend = xt_write_recseq_begin();
1202         xt_entry_foreach(iter, private->entries, private->size) {
1203                 struct xt_counters *tmp;
1204
1205                 tmp = xt_get_this_cpu_counter(&iter->counters);
1206                 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt);
1207                 ++i;
1208         }
1209         xt_write_recseq_end(addend);
1210  unlock_up_free:
1211         local_bh_enable();
1212         xt_table_unlock(t);
1213         module_put(t->me);
1214  free:
1215         vfree(paddc);
1216
1217         return ret;
1218 }
1219
1220 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1221 struct compat_ip6t_replace {
1222         char                    name[XT_TABLE_MAXNAMELEN];
1223         u32                     valid_hooks;
1224         u32                     num_entries;
1225         u32                     size;
1226         u32                     hook_entry[NF_INET_NUMHOOKS];
1227         u32                     underflow[NF_INET_NUMHOOKS];
1228         u32                     num_counters;
1229         compat_uptr_t           counters;       /* struct xt_counters * */
1230         struct compat_ip6t_entry entries[];
1231 };
1232
1233 static int
1234 compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr,
1235                           unsigned int *size, struct xt_counters *counters,
1236                           unsigned int i)
1237 {
1238         struct xt_entry_target *t;
1239         struct compat_ip6t_entry __user *ce;
1240         u_int16_t target_offset, next_offset;
1241         compat_uint_t origsize;
1242         const struct xt_entry_match *ematch;
1243         int ret = 0;
1244
1245         origsize = *size;
1246         ce = *dstptr;
1247         if (copy_to_user(ce, e, sizeof(struct ip6t_entry)) != 0 ||
1248             copy_to_user(&ce->counters, &counters[i],
1249             sizeof(counters[i])) != 0)
1250                 return -EFAULT;
1251
1252         *dstptr += sizeof(struct compat_ip6t_entry);
1253         *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1254
1255         xt_ematch_foreach(ematch, e) {
1256                 ret = xt_compat_match_to_user(ematch, dstptr, size);
1257                 if (ret != 0)
1258                         return ret;
1259         }
1260         target_offset = e->target_offset - (origsize - *size);
1261         t = ip6t_get_target(e);
1262         ret = xt_compat_target_to_user(t, dstptr, size);
1263         if (ret)
1264                 return ret;
1265         next_offset = e->next_offset - (origsize - *size);
1266         if (put_user(target_offset, &ce->target_offset) != 0 ||
1267             put_user(next_offset, &ce->next_offset) != 0)
1268                 return -EFAULT;
1269         return 0;
1270 }
1271
1272 static int
1273 compat_find_calc_match(struct xt_entry_match *m,
1274                        const struct ip6t_ip6 *ipv6,
1275                        int *size)
1276 {
1277         struct xt_match *match;
1278
1279         match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
1280                                       m->u.user.revision);
1281         if (IS_ERR(match))
1282                 return PTR_ERR(match);
1283
1284         m->u.kernel.match = match;
1285         *size += xt_compat_match_offset(match);
1286         return 0;
1287 }
1288
1289 static void compat_release_entry(struct compat_ip6t_entry *e)
1290 {
1291         struct xt_entry_target *t;
1292         struct xt_entry_match *ematch;
1293
1294         /* Cleanup all matches */
1295         xt_ematch_foreach(ematch, e)
1296                 module_put(ematch->u.kernel.match->me);
1297         t = compat_ip6t_get_target(e);
1298         module_put(t->u.kernel.target->me);
1299 }
1300
1301 static int
1302 check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
1303                                   struct xt_table_info *newinfo,
1304                                   unsigned int *size,
1305                                   const unsigned char *base,
1306                                   const unsigned char *limit)
1307 {
1308         struct xt_entry_match *ematch;
1309         struct xt_entry_target *t;
1310         struct xt_target *target;
1311         unsigned int entry_offset;
1312         unsigned int j;
1313         int ret, off;
1314
1315         if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 ||
1316             (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit ||
1317             (unsigned char *)e + e->next_offset > limit)
1318                 return -EINVAL;
1319
1320         if (e->next_offset < sizeof(struct compat_ip6t_entry) +
1321                              sizeof(struct compat_xt_entry_target))
1322                 return -EINVAL;
1323
1324         if (!ip6_checkentry(&e->ipv6))
1325                 return -EINVAL;
1326
1327         ret = xt_compat_check_entry_offsets(e, e->elems,
1328                                             e->target_offset, e->next_offset);
1329         if (ret)
1330                 return ret;
1331
1332         off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1333         entry_offset = (void *)e - (void *)base;
1334         j = 0;
1335         xt_ematch_foreach(ematch, e) {
1336                 ret = compat_find_calc_match(ematch, &e->ipv6, &off);
1337                 if (ret != 0)
1338                         goto release_matches;
1339                 ++j;
1340         }
1341
1342         t = compat_ip6t_get_target(e);
1343         target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
1344                                         t->u.user.revision);
1345         if (IS_ERR(target)) {
1346                 ret = PTR_ERR(target);
1347                 goto release_matches;
1348         }
1349         t->u.kernel.target = target;
1350
1351         off += xt_compat_target_offset(target);
1352         *size += off;
1353         ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
1354         if (ret)
1355                 goto out;
1356
1357         return 0;
1358
1359 out:
1360         module_put(t->u.kernel.target->me);
1361 release_matches:
1362         xt_ematch_foreach(ematch, e) {
1363                 if (j-- == 0)
1364                         break;
1365                 module_put(ematch->u.kernel.match->me);
1366         }
1367         return ret;
1368 }
1369
1370 static void
1371 compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr,
1372                             unsigned int *size,
1373                             struct xt_table_info *newinfo, unsigned char *base)
1374 {
1375         struct xt_entry_target *t;
1376         struct ip6t_entry *de;
1377         unsigned int origsize;
1378         int h;
1379         struct xt_entry_match *ematch;
1380
1381         origsize = *size;
1382         de = *dstptr;
1383         memcpy(de, e, sizeof(struct ip6t_entry));
1384         memcpy(&de->counters, &e->counters, sizeof(e->counters));
1385
1386         *dstptr += sizeof(struct ip6t_entry);
1387         *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1388
1389         xt_ematch_foreach(ematch, e)
1390                 xt_compat_match_from_user(ematch, dstptr, size);
1391
1392         de->target_offset = e->target_offset - (origsize - *size);
1393         t = compat_ip6t_get_target(e);
1394         xt_compat_target_from_user(t, dstptr, size);
1395
1396         de->next_offset = e->next_offset - (origsize - *size);
1397         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1398                 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1399                         newinfo->hook_entry[h] -= origsize - *size;
1400                 if ((unsigned char *)de - base < newinfo->underflow[h])
1401                         newinfo->underflow[h] -= origsize - *size;
1402         }
1403 }
1404
1405 static int
1406 translate_compat_table(struct net *net,
1407                        struct xt_table_info **pinfo,
1408                        void **pentry0,
1409                        const struct compat_ip6t_replace *compatr)
1410 {
1411         unsigned int i, j;
1412         struct xt_table_info *newinfo, *info;
1413         void *pos, *entry0, *entry1;
1414         struct compat_ip6t_entry *iter0;
1415         struct ip6t_replace repl;
1416         unsigned int size;
1417         int ret;
1418
1419         info = *pinfo;
1420         entry0 = *pentry0;
1421         size = compatr->size;
1422         info->number = compatr->num_entries;
1423
1424         j = 0;
1425         xt_compat_lock(AF_INET6);
1426         ret = xt_compat_init_offsets(AF_INET6, compatr->num_entries);
1427         if (ret)
1428                 goto out_unlock;
1429         /* Walk through entries, checking offsets. */
1430         xt_entry_foreach(iter0, entry0, compatr->size) {
1431                 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1432                                                         entry0,
1433                                                         entry0 + compatr->size);
1434                 if (ret != 0)
1435                         goto out_unlock;
1436                 ++j;
1437         }
1438
1439         ret = -EINVAL;
1440         if (j != compatr->num_entries)
1441                 goto out_unlock;
1442
1443         ret = -ENOMEM;
1444         newinfo = xt_alloc_table_info(size);
1445         if (!newinfo)
1446                 goto out_unlock;
1447
1448         memset(newinfo->entries, 0, size);
1449
1450         newinfo->number = compatr->num_entries;
1451         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1452                 newinfo->hook_entry[i] = compatr->hook_entry[i];
1453                 newinfo->underflow[i] = compatr->underflow[i];
1454         }
1455         entry1 = newinfo->entries;
1456         pos = entry1;
1457         size = compatr->size;
1458         xt_entry_foreach(iter0, entry0, compatr->size)
1459                 compat_copy_entry_from_user(iter0, &pos, &size,
1460                                             newinfo, entry1);
1461
1462         /* all module references in entry0 are now gone. */
1463         xt_compat_flush_offsets(AF_INET6);
1464         xt_compat_unlock(AF_INET6);
1465
1466         memcpy(&repl, compatr, sizeof(*compatr));
1467
1468         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1469                 repl.hook_entry[i] = newinfo->hook_entry[i];
1470                 repl.underflow[i] = newinfo->underflow[i];
1471         }
1472
1473         repl.num_counters = 0;
1474         repl.counters = NULL;
1475         repl.size = newinfo->size;
1476         ret = translate_table(net, newinfo, entry1, &repl);
1477         if (ret)
1478                 goto free_newinfo;
1479
1480         *pinfo = newinfo;
1481         *pentry0 = entry1;
1482         xt_free_table_info(info);
1483         return 0;
1484
1485 free_newinfo:
1486         xt_free_table_info(newinfo);
1487         return ret;
1488 out_unlock:
1489         xt_compat_flush_offsets(AF_INET6);
1490         xt_compat_unlock(AF_INET6);
1491         xt_entry_foreach(iter0, entry0, compatr->size) {
1492                 if (j-- == 0)
1493                         break;
1494                 compat_release_entry(iter0);
1495         }
1496         return ret;
1497 }
1498
1499 static int
1500 compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
1501 {
1502         int ret;
1503         struct compat_ip6t_replace tmp;
1504         struct xt_table_info *newinfo;
1505         void *loc_cpu_entry;
1506         struct ip6t_entry *iter;
1507
1508         if (len < sizeof(tmp))
1509                 return -EINVAL;
1510         if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
1511                 return -EFAULT;
1512
1513         /* overflow check */
1514         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1515                 return -ENOMEM;
1516         if (tmp.num_counters == 0)
1517                 return -EINVAL;
1518         if ((u64)len < (u64)tmp.size + sizeof(tmp))
1519                 return -EINVAL;
1520
1521         tmp.name[sizeof(tmp.name)-1] = 0;
1522
1523         newinfo = xt_alloc_table_info(tmp.size);
1524         if (!newinfo)
1525                 return -ENOMEM;
1526
1527         loc_cpu_entry = newinfo->entries;
1528         if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp),
1529                         tmp.size) != 0) {
1530                 ret = -EFAULT;
1531                 goto free_newinfo;
1532         }
1533
1534         ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp);
1535         if (ret != 0)
1536                 goto free_newinfo;
1537
1538         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1539                            tmp.num_counters, compat_ptr(tmp.counters));
1540         if (ret)
1541                 goto free_newinfo_untrans;
1542         return 0;
1543
1544  free_newinfo_untrans:
1545         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1546                 cleanup_entry(iter, net);
1547  free_newinfo:
1548         xt_free_table_info(newinfo);
1549         return ret;
1550 }
1551
1552 struct compat_ip6t_get_entries {
1553         char name[XT_TABLE_MAXNAMELEN];
1554         compat_uint_t size;
1555         struct compat_ip6t_entry entrytable[];
1556 };
1557
1558 static int
1559 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1560                             void __user *userptr)
1561 {
1562         struct xt_counters *counters;
1563         const struct xt_table_info *private = table->private;
1564         void __user *pos;
1565         unsigned int size;
1566         int ret = 0;
1567         unsigned int i = 0;
1568         struct ip6t_entry *iter;
1569
1570         counters = alloc_counters(table);
1571         if (IS_ERR(counters))
1572                 return PTR_ERR(counters);
1573
1574         pos = userptr;
1575         size = total_size;
1576         xt_entry_foreach(iter, private->entries, total_size) {
1577                 ret = compat_copy_entry_to_user(iter, &pos,
1578                                                 &size, counters, i++);
1579                 if (ret != 0)
1580                         break;
1581         }
1582
1583         vfree(counters);
1584         return ret;
1585 }
1586
1587 static int
1588 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr,
1589                    int *len)
1590 {
1591         int ret;
1592         struct compat_ip6t_get_entries get;
1593         struct xt_table *t;
1594
1595         if (*len < sizeof(get))
1596                 return -EINVAL;
1597
1598         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1599                 return -EFAULT;
1600
1601         if (*len != sizeof(struct compat_ip6t_get_entries) + get.size)
1602                 return -EINVAL;
1603
1604         get.name[sizeof(get.name) - 1] = '\0';
1605
1606         xt_compat_lock(AF_INET6);
1607         t = xt_find_table_lock(net, AF_INET6, get.name);
1608         if (!IS_ERR(t)) {
1609                 const struct xt_table_info *private = t->private;
1610                 struct xt_table_info info;
1611                 ret = compat_table_info(private, &info);
1612                 if (!ret && get.size == info.size)
1613                         ret = compat_copy_entries_to_user(private->size,
1614                                                           t, uptr->entrytable);
1615                 else if (!ret)
1616                         ret = -EAGAIN;
1617
1618                 xt_compat_flush_offsets(AF_INET6);
1619                 module_put(t->me);
1620                 xt_table_unlock(t);
1621         } else
1622                 ret = PTR_ERR(t);
1623
1624         xt_compat_unlock(AF_INET6);
1625         return ret;
1626 }
1627 #endif
1628
1629 static int
1630 do_ip6t_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len)
1631 {
1632         int ret;
1633
1634         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1635                 return -EPERM;
1636
1637         switch (cmd) {
1638         case IP6T_SO_SET_REPLACE:
1639 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1640                 if (in_compat_syscall())
1641                         ret = compat_do_replace(sock_net(sk), arg, len);
1642                 else
1643 #endif
1644                         ret = do_replace(sock_net(sk), arg, len);
1645                 break;
1646
1647         case IP6T_SO_SET_ADD_COUNTERS:
1648                 ret = do_add_counters(sock_net(sk), arg, len);
1649                 break;
1650
1651         default:
1652                 ret = -EINVAL;
1653         }
1654
1655         return ret;
1656 }
1657
1658 static int
1659 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1660 {
1661         int ret;
1662
1663         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1664                 return -EPERM;
1665
1666         switch (cmd) {
1667         case IP6T_SO_GET_INFO:
1668                 ret = get_info(sock_net(sk), user, len);
1669                 break;
1670
1671         case IP6T_SO_GET_ENTRIES:
1672 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1673                 if (in_compat_syscall())
1674                         ret = compat_get_entries(sock_net(sk), user, len);
1675                 else
1676 #endif
1677                         ret = get_entries(sock_net(sk), user, len);
1678                 break;
1679
1680         case IP6T_SO_GET_REVISION_MATCH:
1681         case IP6T_SO_GET_REVISION_TARGET: {
1682                 struct xt_get_revision rev;
1683                 int target;
1684
1685                 if (*len != sizeof(rev)) {
1686                         ret = -EINVAL;
1687                         break;
1688                 }
1689                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1690                         ret = -EFAULT;
1691                         break;
1692                 }
1693                 rev.name[sizeof(rev.name)-1] = 0;
1694
1695                 if (cmd == IP6T_SO_GET_REVISION_TARGET)
1696                         target = 1;
1697                 else
1698                         target = 0;
1699
1700                 try_then_request_module(xt_find_revision(AF_INET6, rev.name,
1701                                                          rev.revision,
1702                                                          target, &ret),
1703                                         "ip6t_%s", rev.name);
1704                 break;
1705         }
1706
1707         default:
1708                 ret = -EINVAL;
1709         }
1710
1711         return ret;
1712 }
1713
1714 static void __ip6t_unregister_table(struct net *net, struct xt_table *table)
1715 {
1716         struct xt_table_info *private;
1717         void *loc_cpu_entry;
1718         struct module *table_owner = table->me;
1719         struct ip6t_entry *iter;
1720
1721         private = xt_unregister_table(table);
1722
1723         /* Decrease module usage counts and free resources */
1724         loc_cpu_entry = private->entries;
1725         xt_entry_foreach(iter, loc_cpu_entry, private->size)
1726                 cleanup_entry(iter, net);
1727         if (private->number > private->initial_entries)
1728                 module_put(table_owner);
1729         xt_free_table_info(private);
1730 }
1731
1732 int ip6t_register_table(struct net *net, const struct xt_table *table,
1733                         const struct ip6t_replace *repl,
1734                         const struct nf_hook_ops *template_ops)
1735 {
1736         struct nf_hook_ops *ops;
1737         unsigned int num_ops;
1738         int ret, i;
1739         struct xt_table_info *newinfo;
1740         struct xt_table_info bootstrap = {0};
1741         void *loc_cpu_entry;
1742         struct xt_table *new_table;
1743
1744         newinfo = xt_alloc_table_info(repl->size);
1745         if (!newinfo)
1746                 return -ENOMEM;
1747
1748         loc_cpu_entry = newinfo->entries;
1749         memcpy(loc_cpu_entry, repl->entries, repl->size);
1750
1751         ret = translate_table(net, newinfo, loc_cpu_entry, repl);
1752         if (ret != 0) {
1753                 xt_free_table_info(newinfo);
1754                 return ret;
1755         }
1756
1757         new_table = xt_register_table(net, table, &bootstrap, newinfo);
1758         if (IS_ERR(new_table)) {
1759                 struct ip6t_entry *iter;
1760
1761                 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1762                         cleanup_entry(iter, net);
1763                 xt_free_table_info(newinfo);
1764                 return PTR_ERR(new_table);
1765         }
1766
1767         if (!template_ops)
1768                 return 0;
1769
1770         num_ops = hweight32(table->valid_hooks);
1771         if (num_ops == 0) {
1772                 ret = -EINVAL;
1773                 goto out_free;
1774         }
1775
1776         ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
1777         if (!ops) {
1778                 ret = -ENOMEM;
1779                 goto out_free;
1780         }
1781
1782         for (i = 0; i < num_ops; i++)
1783                 ops[i].priv = new_table;
1784
1785         new_table->ops = ops;
1786
1787         ret = nf_register_net_hooks(net, ops, num_ops);
1788         if (ret != 0)
1789                 goto out_free;
1790
1791         return ret;
1792
1793 out_free:
1794         __ip6t_unregister_table(net, new_table);
1795         return ret;
1796 }
1797
1798 void ip6t_unregister_table_pre_exit(struct net *net, const char *name)
1799 {
1800         struct xt_table *table = xt_find_table(net, NFPROTO_IPV6, name);
1801
1802         if (table)
1803                 nf_unregister_net_hooks(net, table->ops, hweight32(table->valid_hooks));
1804 }
1805
1806 void ip6t_unregister_table_exit(struct net *net, const char *name)
1807 {
1808         struct xt_table *table = xt_find_table(net, NFPROTO_IPV6, name);
1809
1810         if (table)
1811                 __ip6t_unregister_table(net, table);
1812 }
1813
1814 /* The built-in targets: standard (NULL) and error. */
1815 static struct xt_target ip6t_builtin_tg[] __read_mostly = {
1816         {
1817                 .name             = XT_STANDARD_TARGET,
1818                 .targetsize       = sizeof(int),
1819                 .family           = NFPROTO_IPV6,
1820 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1821                 .compatsize       = sizeof(compat_int_t),
1822                 .compat_from_user = compat_standard_from_user,
1823                 .compat_to_user   = compat_standard_to_user,
1824 #endif
1825         },
1826         {
1827                 .name             = XT_ERROR_TARGET,
1828                 .target           = ip6t_error,
1829                 .targetsize       = XT_FUNCTION_MAXNAMELEN,
1830                 .family           = NFPROTO_IPV6,
1831         },
1832 };
1833
1834 static struct nf_sockopt_ops ip6t_sockopts = {
1835         .pf             = PF_INET6,
1836         .set_optmin     = IP6T_BASE_CTL,
1837         .set_optmax     = IP6T_SO_SET_MAX+1,
1838         .set            = do_ip6t_set_ctl,
1839         .get_optmin     = IP6T_BASE_CTL,
1840         .get_optmax     = IP6T_SO_GET_MAX+1,
1841         .get            = do_ip6t_get_ctl,
1842         .owner          = THIS_MODULE,
1843 };
1844
1845 static int __net_init ip6_tables_net_init(struct net *net)
1846 {
1847         return xt_proto_init(net, NFPROTO_IPV6);
1848 }
1849
1850 static void __net_exit ip6_tables_net_exit(struct net *net)
1851 {
1852         xt_proto_fini(net, NFPROTO_IPV6);
1853 }
1854
1855 static struct pernet_operations ip6_tables_net_ops = {
1856         .init = ip6_tables_net_init,
1857         .exit = ip6_tables_net_exit,
1858 };
1859
1860 static int __init ip6_tables_init(void)
1861 {
1862         int ret;
1863
1864         ret = register_pernet_subsys(&ip6_tables_net_ops);
1865         if (ret < 0)
1866                 goto err1;
1867
1868         /* No one else will be downing sem now, so we won't sleep */
1869         ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1870         if (ret < 0)
1871                 goto err2;
1872
1873         /* Register setsockopt */
1874         ret = nf_register_sockopt(&ip6t_sockopts);
1875         if (ret < 0)
1876                 goto err4;
1877
1878         return 0;
1879
1880 err4:
1881         xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1882 err2:
1883         unregister_pernet_subsys(&ip6_tables_net_ops);
1884 err1:
1885         return ret;
1886 }
1887
1888 static void __exit ip6_tables_fini(void)
1889 {
1890         nf_unregister_sockopt(&ip6t_sockopts);
1891
1892         xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1893         unregister_pernet_subsys(&ip6_tables_net_ops);
1894 }
1895
1896 EXPORT_SYMBOL(ip6t_register_table);
1897 EXPORT_SYMBOL(ip6t_unregister_table_pre_exit);
1898 EXPORT_SYMBOL(ip6t_unregister_table_exit);
1899 EXPORT_SYMBOL(ip6t_do_table);
1900
1901 module_init(ip6_tables_init);
1902 module_exit(ip6_tables_fini);