net/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 <linux/icmpv6.h>
  22 #include <net/ipv6.h>
  23 #include <net/compat.h>
  24 #include <linux/uaccess.h>
  25 #include <linux/mutex.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/err.h>
  28 #include <linux/cpumask.h>
  29
  30 #include <linux/netfilter_ipv6/ip6_tables.h>
  31 #include <linux/netfilter/x_tables.h>
  32 #include <net/netfilter/nf_log.h>
  33 #include "../../netfilter/xt_repldata.h"
  34
  35 MODULE_LICENSE("GPL");
  36 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  37 MODULE_DESCRIPTION("IPv6 packet filter");
  38 MODULE_ALIAS("ip6t_icmp6");
  39
  40 void *ip6t_alloc_initial_table(const struct xt_table *info)
  41 {
  42         return xt_alloc_initial_table(ip6t, IP6T);
  43 }
  44 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table);
  45
  46 /* Returns whether matches rule or not. */
  47 /* Performance critical - called for every packet */
  48 static inline bool
  49 ip6_packet_match(const struct sk_buff *skb,
  50                  const char *indev,
  51                  const char *outdev,
  52                  const struct ip6t_ip6 *ip6info,
  53                  unsigned int *protoff,
  54                  int *fragoff, bool *hotdrop)
  55 {
  56         unsigned long ret;
  57         const struct ipv6hdr *ipv6 = ipv6_hdr(skb);
  58
  59         if (NF_INVF(ip6info, IP6T_INV_SRCIP,
  60                     ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk,
  61                                          &ip6info->src)) ||
  62             NF_INVF(ip6info, IP6T_INV_DSTIP,
  63                     ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk,
  64                                          &ip6info->dst)))
  65                 return false;
  66
  67         ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask);
  68
  69         if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0))
  70                 return false;
  71
  72         ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask);
  73
  74         if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0))
  75                 return false;
  76
  77 /* ... might want to do something with class and flowlabel here ... */
  78
  79         /* look for the desired protocol header */
  80         if (ip6info->flags & IP6T_F_PROTO) {
  81                 int protohdr;
  82                 unsigned short _frag_off;
  83
  84                 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL);
  85                 if (protohdr < 0) {
  86                         if (_frag_off == 0)
  87                                 *hotdrop = true;
  88                         return false;
  89                 }
  90                 *fragoff = _frag_off;
  91
  92                 if (ip6info->proto == protohdr) {
  93                         if (ip6info->invflags & IP6T_INV_PROTO)
  94                                 return false;
  95
  96                         return true;
  97                 }
  98
  99                 /* We need match for the '-p all', too! */
 100                 if ((ip6info->proto != 0) &&
 101                         !(ip6info->invflags & IP6T_INV_PROTO))
 102                         return false;
 103         }
 104         return true;
 105 }
 106
 107 /* should be ip6 safe */
 108 static bool
 109 ip6_checkentry(const struct ip6t_ip6 *ipv6)
 110 {
 111         if (ipv6->flags & ~IP6T_F_MASK)
 112                 return false;
 113         if (ipv6->invflags & ~IP6T_INV_MASK)
 114                 return false;
 115
 116         return true;
 117 }
 118
 119 static unsigned int
 120 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par)
 121 {
 122         net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);
 123
 124         return NF_DROP;
 125 }
 126
 127 static inline struct ip6t_entry *
 128 get_entry(const void *base, unsigned int offset)
 129 {
 130         return (struct ip6t_entry *)(base + offset);
 131 }
 132
 133 /* All zeroes == unconditional rule. */
 134 /* Mildly perf critical (only if packet tracing is on) */
 135 static inline bool unconditional(const struct ip6t_entry *e)
 136 {
 137         static const struct ip6t_ip6 uncond;
 138
 139         return e->target_offset == sizeof(struct ip6t_entry) &&
 140                memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0;
 141 }
 142
 143 static inline const struct xt_entry_target *
 144 ip6t_get_target_c(const struct ip6t_entry *e)
 145 {
 146         return ip6t_get_target((struct ip6t_entry *)e);
 147 }
 148
 149 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
 150 /* This cries for unification! */
 151 static const char *const hooknames[] = {
 152         [NF_INET_PRE_ROUTING]           = "PREROUTING",
 153         [NF_INET_LOCAL_IN]              = "INPUT",
 154         [NF_INET_FORWARD]               = "FORWARD",
 155         [NF_INET_LOCAL_OUT]             = "OUTPUT",
 156         [NF_INET_POST_ROUTING]          = "POSTROUTING",
 157 };
 158
 159 enum nf_ip_trace_comments {
 160         NF_IP6_TRACE_COMMENT_RULE,
 161         NF_IP6_TRACE_COMMENT_RETURN,
 162         NF_IP6_TRACE_COMMENT_POLICY,
 163 };
 164
 165 static const char *const comments[] = {
 166         [NF_IP6_TRACE_COMMENT_RULE]     = "rule",
 167         [NF_IP6_TRACE_COMMENT_RETURN]   = "return",
 168         [NF_IP6_TRACE_COMMENT_POLICY]   = "policy",
 169 };
 170
 171 static const struct nf_loginfo trace_loginfo = {
 172         .type = NF_LOG_TYPE_LOG,
 173         .u = {
 174                 .log = {
 175                         .level = LOGLEVEL_WARNING,
 176                         .logflags = NF_LOG_DEFAULT_MASK,
 177                 },
 178         },
 179 };
 180
 181 /* Mildly perf critical (only if packet tracing is on) */
 182 static inline int
 183 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e,
 184                       const char *hookname, const char **chainname,
 185                       const char **comment, unsigned int *rulenum)
 186 {
 187         const struct xt_standard_target *t = (void *)ip6t_get_target_c(s);
 188
 189         if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
 190                 /* Head of user chain: ERROR target with chainname */
 191                 *chainname = t->target.data;
 192                 (*rulenum) = 0;
 193         } else if (s == e) {
 194                 (*rulenum)++;
 195
 196                 if (unconditional(s) &&
 197                     strcmp(t->target.u.kernel.target->name,
 198                            XT_STANDARD_TARGET) == 0 &&
 199                     t->verdict < 0) {
 200                         /* Tail of chains: STANDARD target (return/policy) */
 201                         *comment = *chainname == hookname
 202                                 ? comments[NF_IP6_TRACE_COMMENT_POLICY]
 203                                 : comments[NF_IP6_TRACE_COMMENT_RETURN];
 204                 }
 205                 return 1;
 206         } else
 207                 (*rulenum)++;
 208
 209         return 0;
 210 }
 211
 212 static void trace_packet(struct net *net,
 213                          const struct sk_buff *skb,
 214                          unsigned int hook,
 215                          const struct net_device *in,
 216                          const struct net_device *out,
 217                          const char *tablename,
 218                          const struct xt_table_info *private,
 219                          const struct ip6t_entry *e)
 220 {
 221         const struct ip6t_entry *root;
 222         const char *hookname, *chainname, *comment;
 223         const struct ip6t_entry *iter;
 224         unsigned int rulenum = 0;
 225
 226         root = get_entry(private->entries, private->hook_entry[hook]);
 227
 228         hookname = chainname = hooknames[hook];
 229         comment = comments[NF_IP6_TRACE_COMMENT_RULE];
 230
 231         xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
 232                 if (get_chainname_rulenum(iter, e, hookname,
 233                     &chainname, &comment, &rulenum) != 0)
 234                         break;
 235
 236         nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
 237                      "TRACE: %s:%s:%s:%u ",
 238                      tablename, chainname, comment, rulenum);
 239 }
 240 #endif
 241
 242 static inline struct ip6t_entry *
 243 ip6t_next_entry(const struct ip6t_entry *entry)
 244 {
 245         return (void *)entry + entry->next_offset;
 246 }
 247
 248 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
 249 unsigned int
 250 ip6t_do_table(struct sk_buff *skb,
 251               const struct nf_hook_state *state,
 252               struct xt_table *table)
 253 {
 254         unsigned int hook = state->hook;
 255         static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
 256         /* Initializing verdict to NF_DROP keeps gcc happy. */
 257         unsigned int verdict = NF_DROP;
 258         const char *indev, *outdev;
 259         const void *table_base;
 260         struct ip6t_entry *e, **jumpstack;
 261         unsigned int stackidx, cpu;
 262         const struct xt_table_info *private;
 263         struct xt_action_param acpar;
 264         unsigned int addend;
 265
 266         /* Initialization */
 267         stackidx = 0;
 268         indev = state->in ? state->in->name : nulldevname;
 269         outdev = state->out ? state->out->name : nulldevname;
 270         /* We handle fragments by dealing with the first fragment as
 271          * if it was a normal packet.  All other fragments are treated
 272          * normally, except that they will NEVER match rules that ask
 273          * things we don't know, ie. tcp syn flag or ports).  If the
 274          * rule is also a fragment-specific rule, non-fragments won't
 275          * match it. */
 276         acpar.hotdrop = false;
 277         acpar.state   = state;
 278
 279         WARN_ON(!(table->valid_hooks & (1 << hook)));
 280
 281         local_bh_disable();
 282         addend = xt_write_recseq_begin();
 283         private = READ_ONCE(table->private); /* Address dependency. */
 284         cpu        = smp_processor_id();
 285         table_base = private->entries;
 286         jumpstack  = (struct ip6t_entry **)private->jumpstack[cpu];
 287
 288         /* Switch to alternate jumpstack if we're being invoked via TEE.
 289          * TEE issues XT_CONTINUE verdict on original skb so we must not
 290          * clobber the jumpstack.
 291          *
 292          * For recursion via REJECT or SYNPROXY the stack will be clobbered
 293          * but it is no problem since absolute verdict is issued by these.
 294          */
 295         if (static_key_false(&xt_tee_enabled))
 296                 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
 297
 298         e = get_entry(table_base, private->hook_entry[hook]);
 299
 300         do {
 301                 const struct xt_entry_target *t;
 302                 const struct xt_entry_match *ematch;
 303                 struct xt_counters *counter;
 304
 305                 WARN_ON(!e);
 306                 acpar.thoff = 0;
 307                 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6,
 308                     &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) {
 309  no_match:
 310                         e = ip6t_next_entry(e);
 311                         continue;
 312                 }
 313
 314                 xt_ematch_foreach(ematch, e) {
 315                         acpar.match     = ematch->u.kernel.match;
 316                         acpar.matchinfo = ematch->data;
 317                         if (!acpar.match->match(skb, &acpar))
 318                                 goto no_match;
 319                 }
 320
 321                 counter = xt_get_this_cpu_counter(&e->counters);
 322                 ADD_COUNTER(*counter, skb->len, 1);
 323
 324                 t = ip6t_get_target_c(e);
 325                 WARN_ON(!t->u.kernel.target);
 326
 327 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
 328                 /* The packet is traced: log it */
 329                 if (unlikely(skb->nf_trace))
 330                         trace_packet(state->net, skb, hook, state->in,
 331                                      state->out, table->name, private, e);
 332 #endif
 333                 /* Standard target? */
 334                 if (!t->u.kernel.target->target) {
 335                         int v;
 336
 337                         v = ((struct xt_standard_target *)t)->verdict;
 338                         if (v < 0) {
 339                                 /* Pop from stack? */
 340                                 if (v != XT_RETURN) {
 341                                         verdict = (unsigned int)(-v) - 1;
 342                                         break;
 343                                 }
 344                                 if (stackidx == 0)
 345                                         e = get_entry(table_base,
 346                                             private->underflow[hook]);
 347                                 else
 348                                         e = ip6t_next_entry(jumpstack[--stackidx]);
 349                                 continue;
 350                         }
 351                         if (table_base + v != ip6t_next_entry(e) &&
 352                             !(e->ipv6.flags & IP6T_F_GOTO)) {
 353                                 if (unlikely(stackidx >= private->stacksize)) {
 354                                         verdict = NF_DROP;
 355                                         break;
 356                                 }
 357                                 jumpstack[stackidx++] = e;
 358                         }
 359
 360                         e = get_entry(table_base, v);
 361                         continue;
 362                 }
 363
 364                 acpar.target   = t->u.kernel.target;
 365                 acpar.targinfo = t->data;
 366
 367                 verdict = t->u.kernel.target->target(skb, &acpar);
 368                 if (verdict == XT_CONTINUE)
 369                         e = ip6t_next_entry(e);
 370                 else
 371                         /* Verdict */
 372                         break;
 373         } while (!acpar.hotdrop);
 374
 375         xt_write_recseq_end(addend);
 376         local_bh_enable();
 377
 378         if (acpar.hotdrop)
 379                 return NF_DROP;
 380         else return verdict;
 381 }
 382
 383 /* Figures out from what hook each rule can be called: returns 0 if
 384    there are loops.  Puts hook bitmask in comefrom. */
 385 static int
 386 mark_source_chains(const struct xt_table_info *newinfo,
 387                    unsigned int valid_hooks, void *entry0,
 388                    unsigned int *offsets)
 389 {
 390         unsigned int hook;
 391
 392         /* No recursion; use packet counter to save back ptrs (reset
 393            to 0 as we leave), and comefrom to save source hook bitmask */
 394         for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
 395                 unsigned int pos = newinfo->hook_entry[hook];
 396                 struct ip6t_entry *e = entry0 + pos;
 397
 398                 if (!(valid_hooks & (1 << hook)))
 399                         continue;
 400
 401                 /* Set initial back pointer. */
 402                 e->counters.pcnt = pos;
 403
 404                 for (;;) {
 405                         const struct xt_standard_target *t
 406                                 = (void *)ip6t_get_target_c(e);
 407                         int visited = e->comefrom & (1 << hook);
 408
 409                         if (e->comefrom & (1 << NF_INET_NUMHOOKS))
 410                                 return 0;
 411
 412                         e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
 413
 414                         /* Unconditional return/END. */
 415                         if ((unconditional(e) &&
 416                              (strcmp(t->target.u.user.name,
 417                                      XT_STANDARD_TARGET) == 0) &&
 418                              t->verdict < 0) || visited) {
 419                                 unsigned int oldpos, size;
 420
 421                                 /* Return: backtrack through the last
 422                                    big jump. */
 423                                 do {
 424                                         e->comefrom ^= (1<<NF_INET_NUMHOOKS);
 425                                         oldpos = pos;
 426                                         pos = e->counters.pcnt;
 427                                         e->counters.pcnt = 0;
 428
 429                                         /* We're at the start. */
 430                                         if (pos == oldpos)
 431                                                 goto next;
 432
 433                                         e = entry0 + pos;
 434                                 } while (oldpos == pos + e->next_offset);
 435
 436                                 /* Move along one */
 437                                 size = e->next_offset;
 438                                 e = entry0 + pos + size;
 439                                 if (pos + size >= newinfo->size)
 440                                         return 0;
 441                                 e->counters.pcnt = pos;
 442                                 pos += size;
 443                         } else {
 444                                 int newpos = t->verdict;
 445
 446                                 if (strcmp(t->target.u.user.name,
 447                                            XT_STANDARD_TARGET) == 0 &&
 448                                     newpos >= 0) {
 449                                         /* This a jump; chase it. */
 450                                         if (!xt_find_jump_offset(offsets, newpos,
 451                                                                  newinfo->number))
 452                                                 return 0;
 453                                 } else {
 454                                         /* ... this is a fallthru */
 455                                         newpos = pos + e->next_offset;
 456                                         if (newpos >= newinfo->size)
 457                                                 return 0;
 458                                 }
 459                                 e = entry0 + newpos;
 460                                 e->counters.pcnt = pos;
 461                                 pos = newpos;
 462                         }
 463                 }
 464 next:           ;
 465         }
 466         return 1;
 467 }
 468
 469 static void cleanup_match(struct xt_entry_match *m, struct net *net)
 470 {
 471         struct xt_mtdtor_param par;
 472
 473         par.net       = net;
 474         par.match     = m->u.kernel.match;
 475         par.matchinfo = m->data;
 476         par.family    = NFPROTO_IPV6;
 477         if (par.match->destroy != NULL)
 478                 par.match->destroy(&par);
 479         module_put(par.match->me);
 480 }
 481
 482 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
 483 {
 484         const struct ip6t_ip6 *ipv6 = par->entryinfo;
 485
 486         par->match     = m->u.kernel.match;
 487         par->matchinfo = m->data;
 488
 489         return xt_check_match(par, m->u.match_size - sizeof(*m),
 490                               ipv6->proto, ipv6->invflags & IP6T_INV_PROTO);
 491 }
 492
 493 static int
 494 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
 495 {
 496         struct xt_match *match;
 497         int ret;
 498
 499         match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
 500                                       m->u.user.revision);
 501         if (IS_ERR(match))
 502                 return PTR_ERR(match);
 503
 504         m->u.kernel.match = match;
 505
 506         ret = check_match(m, par);
 507         if (ret)
 508                 goto err;
 509
 510         return 0;
 511 err:
 512         module_put(m->u.kernel.match->me);
 513         return ret;
 514 }
 515
 516 static int check_target(struct ip6t_entry *e, struct net *net, const char *name)
 517 {
 518         struct xt_entry_target *t = ip6t_get_target(e);
 519         struct xt_tgchk_param par = {
 520                 .net       = net,
 521                 .table     = name,
 522                 .entryinfo = e,
 523                 .target    = t->u.kernel.target,
 524                 .targinfo  = t->data,
 525                 .hook_mask = e->comefrom,
 526                 .family    = NFPROTO_IPV6,
 527         };
 528
 529         return xt_check_target(&par, t->u.target_size - sizeof(*t),
 530                                e->ipv6.proto,
 531                                e->ipv6.invflags & IP6T_INV_PROTO);
 532 }
 533
 534 static int
 535 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
 536                  unsigned int size,
 537                  struct xt_percpu_counter_alloc_state *alloc_state)
 538 {
 539         struct xt_entry_target *t;
 540         struct xt_target *target;
 541         int ret;
 542         unsigned int j;
 543         struct xt_mtchk_param mtpar;
 544         struct xt_entry_match *ematch;
 545
 546         if (!xt_percpu_counter_alloc(alloc_state, &e->counters))
 547                 return -ENOMEM;
 548
 549         j = 0;
 550         memset(&mtpar, 0, sizeof(mtpar));
 551         mtpar.net       = net;
 552         mtpar.table     = name;
 553         mtpar.entryinfo = &e->ipv6;
 554         mtpar.hook_mask = e->comefrom;
 555         mtpar.family    = NFPROTO_IPV6;
 556         xt_ematch_foreach(ematch, e) {
 557                 ret = find_check_match(ematch, &mtpar);
 558                 if (ret != 0)
 559                         goto cleanup_matches;
 560                 ++j;
 561         }
 562
 563         t = ip6t_get_target(e);
 564         target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
 565                                         t->u.user.revision);
 566         if (IS_ERR(target)) {
 567                 ret = PTR_ERR(target);
 568                 goto cleanup_matches;
 569         }
 570         t->u.kernel.target = target;
 571
 572         ret = check_target(e, net, name);
 573         if (ret)
 574                 goto err;
 575         return 0;
 576  err:
 577         module_put(t->u.kernel.target->me);
 578  cleanup_matches:
 579         xt_ematch_foreach(ematch, e) {
 580                 if (j-- == 0)
 581                         break;
 582                 cleanup_match(ematch, net);
 583         }
 584
 585         xt_percpu_counter_free(&e->counters);
 586
 587         return ret;
 588 }
 589
 590 static bool check_underflow(const struct ip6t_entry *e)
 591 {
 592         const struct xt_entry_target *t;
 593         unsigned int verdict;
 594
 595         if (!unconditional(e))
 596                 return false;
 597         t = ip6t_get_target_c(e);
 598         if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
 599                 return false;
 600         verdict = ((struct xt_standard_target *)t)->verdict;
 601         verdict = -verdict - 1;
 602         return verdict == NF_DROP || verdict == NF_ACCEPT;
 603 }
 604
 605 static int
 606 check_entry_size_and_hooks(struct ip6t_entry *e,
 607                            struct xt_table_info *newinfo,
 608                            const unsigned char *base,
 609                            const unsigned char *limit,
 610                            const unsigned int *hook_entries,
 611                            const unsigned int *underflows,
 612                            unsigned int valid_hooks)
 613 {
 614         unsigned int h;
 615         int err;
 616
 617         if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 ||
 618             (unsigned char *)e + sizeof(struct ip6t_entry) >= limit ||
 619             (unsigned char *)e + e->next_offset > limit)
 620                 return -EINVAL;
 621
 622         if (e->next_offset
 623             < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target))
 624                 return -EINVAL;
 625
 626         if (!ip6_checkentry(&e->ipv6))
 627                 return -EINVAL;
 628
 629         err = xt_check_entry_offsets(e, e->elems, e->target_offset,
 630                                      e->next_offset);
 631         if (err)
 632                 return err;
 633
 634         /* Check hooks & underflows */
 635         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
 636                 if (!(valid_hooks & (1 << h)))
 637                         continue;
 638                 if ((unsigned char *)e - base == hook_entries[h])
 639                         newinfo->hook_entry[h] = hook_entries[h];
 640                 if ((unsigned char *)e - base == underflows[h]) {
 641                         if (!check_underflow(e))
 642                                 return -EINVAL;
 643
 644                         newinfo->underflow[h] = underflows[h];
 645                 }
 646         }
 647
 648         /* Clear counters and comefrom */
 649         e->counters = ((struct xt_counters) { 0, 0 });
 650         e->comefrom = 0;
 651         return 0;
 652 }
 653
 654 static void cleanup_entry(struct ip6t_entry *e, struct net *net)
 655 {
 656         struct xt_tgdtor_param par;
 657         struct xt_entry_target *t;
 658         struct xt_entry_match *ematch;
 659
 660         /* Cleanup all matches */
 661         xt_ematch_foreach(ematch, e)
 662                 cleanup_match(ematch, net);
 663         t = ip6t_get_target(e);
 664
 665         par.net      = net;
 666         par.target   = t->u.kernel.target;
 667         par.targinfo = t->data;
 668         par.family   = NFPROTO_IPV6;
 669         if (par.target->destroy != NULL)
 670                 par.target->destroy(&par);
 671         module_put(par.target->me);
 672         xt_percpu_counter_free(&e->counters);
 673 }
 674
 675 /* Checks and translates the user-supplied table segment (held in
 676    newinfo) */
 677 static int
 678 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
 679                 const struct ip6t_replace *repl)
 680 {
 681         struct xt_percpu_counter_alloc_state alloc_state = { 0 };
 682         struct ip6t_entry *iter;
 683         unsigned int *offsets;
 684         unsigned int i;
 685         int ret = 0;
 686
 687         newinfo->size = repl->size;
 688         newinfo->number = repl->num_entries;
 689
 690         /* Init all hooks to impossible value. */
 691         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 692                 newinfo->hook_entry[i] = 0xFFFFFFFF;
 693                 newinfo->underflow[i] = 0xFFFFFFFF;
 694         }
 695
 696         offsets = xt_alloc_entry_offsets(newinfo->number);
 697         if (!offsets)
 698                 return -ENOMEM;
 699         i = 0;
 700         /* Walk through entries, checking offsets. */
 701         xt_entry_foreach(iter, entry0, newinfo->size) {
 702                 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
 703                                                  entry0 + repl->size,
 704                                                  repl->hook_entry,
 705                                                  repl->underflow,
 706                                                  repl->valid_hooks);
 707                 if (ret != 0)
 708                         goto out_free;
 709                 if (i < repl->num_entries)
 710                         offsets[i] = (void *)iter - entry0;
 711                 ++i;
 712                 if (strcmp(ip6t_get_target(iter)->u.user.name,
 713                     XT_ERROR_TARGET) == 0)
 714                         ++newinfo->stacksize;
 715         }
 716
 717         ret = -EINVAL;
 718         if (i != repl->num_entries)
 719                 goto out_free;
 720
 721         ret = xt_check_table_hooks(newinfo, repl->valid_hooks);
 722         if (ret)
 723                 goto out_free;
 724
 725         if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) {
 726                 ret = -ELOOP;
 727                 goto out_free;
 728         }
 729         kvfree(offsets);
 730
 731         /* Finally, each sanity check must pass */
 732         i = 0;
 733         xt_entry_foreach(iter, entry0, newinfo->size) {
 734                 ret = find_check_entry(iter, net, repl->name, repl->size,
 735                                        &alloc_state);
 736                 if (ret != 0)
 737                         break;
 738                 ++i;
 739         }
 740
 741         if (ret != 0) {
 742                 xt_entry_foreach(iter, entry0, newinfo->size) {
 743                         if (i-- == 0)
 744                                 break;
 745                         cleanup_entry(iter, net);
 746                 }
 747                 return ret;
 748         }
 749
 750         return ret;
 751  out_free:
 752         kvfree(offsets);
 753         return ret;
 754 }
 755
 756 static void
 757 get_counters(const struct xt_table_info *t,
 758              struct xt_counters counters[])
 759 {
 760         struct ip6t_entry *iter;
 761         unsigned int cpu;
 762         unsigned int i;
 763
 764         for_each_possible_cpu(cpu) {
 765                 seqcount_t *s = &per_cpu(xt_recseq, cpu);
 766
 767                 i = 0;
 768                 xt_entry_foreach(iter, t->entries, t->size) {
 769                         struct xt_counters *tmp;
 770                         u64 bcnt, pcnt;
 771                         unsigned int start;
 772
 773                         tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
 774                         do {
 775                                 start = read_seqcount_begin(s);
 776                                 bcnt = tmp->bcnt;
 777                                 pcnt = tmp->pcnt;
 778                         } while (read_seqcount_retry(s, start));
 779
 780                         ADD_COUNTER(counters[i], bcnt, pcnt);
 781                         ++i;
 782                         cond_resched();
 783                 }
 784         }
 785 }
 786
 787 static void get_old_counters(const struct xt_table_info *t,
 788                              struct xt_counters counters[])
 789 {
 790         struct ip6t_entry *iter;
 791         unsigned int cpu, i;
 792
 793         for_each_possible_cpu(cpu) {
 794                 i = 0;
 795                 xt_entry_foreach(iter, t->entries, t->size) {
 796                         const struct xt_counters *tmp;
 797
 798                         tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
 799                         ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt);
 800                         ++i;
 801                 }
 802                 cond_resched();
 803         }
 804 }
 805
 806 static struct xt_counters *alloc_counters(const struct xt_table *table)
 807 {
 808         unsigned int countersize;
 809         struct xt_counters *counters;
 810         const struct xt_table_info *private = table->private;
 811
 812         /* We need atomic snapshot of counters: rest doesn't change
 813            (other than comefrom, which userspace doesn't care
 814            about). */
 815         countersize = sizeof(struct xt_counters) * private->number;
 816         counters = vzalloc(countersize);
 817
 818         if (counters == NULL)
 819                 return ERR_PTR(-ENOMEM);
 820
 821         get_counters(private, counters);
 822
 823         return counters;
 824 }
 825
 826 static int
 827 copy_entries_to_user(unsigned int total_size,
 828                      const struct xt_table *table,
 829                      void __user *userptr)
 830 {
 831         unsigned int off, num;
 832         const struct ip6t_entry *e;
 833         struct xt_counters *counters;
 834         const struct xt_table_info *private = table->private;
 835         int ret = 0;
 836         const void *loc_cpu_entry;
 837
 838         counters = alloc_counters(table);
 839         if (IS_ERR(counters))
 840                 return PTR_ERR(counters);
 841
 842         loc_cpu_entry = private->entries;
 843
 844         /* FIXME: use iterator macros --RR */
 845         /* ... then go back and fix counters and names */
 846         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
 847                 unsigned int i;
 848                 const struct xt_entry_match *m;
 849                 const struct xt_entry_target *t;
 850
 851                 e = loc_cpu_entry + off;
 852                 if (copy_to_user(userptr + off, e, sizeof(*e))) {
 853                         ret = -EFAULT;
 854                         goto free_counters;
 855                 }
 856                 if (copy_to_user(userptr + off
 857                                  + offsetof(struct ip6t_entry, counters),
 858                                  &counters[num],
 859                                  sizeof(counters[num])) != 0) {
 860                         ret = -EFAULT;
 861                         goto free_counters;
 862                 }
 863
 864                 for (i = sizeof(struct ip6t_entry);
 865                      i < e->target_offset;
 866                      i += m->u.match_size) {
 867                         m = (void *)e + i;
 868
 869                         if (xt_match_to_user(m, userptr + off + i)) {
 870                                 ret = -EFAULT;
 871                                 goto free_counters;
 872                         }
 873                 }
 874
 875                 t = ip6t_get_target_c(e);
 876                 if (xt_target_to_user(t, userptr + off + e->target_offset)) {
 877                         ret = -EFAULT;
 878                         goto free_counters;
 879                 }
 880         }
 881
 882  free_counters:
 883         vfree(counters);
 884         return ret;
 885 }
 886
 887 #ifdef CONFIG_COMPAT
 888 static void compat_standard_from_user(void *dst, const void *src)
 889 {
 890         int v = *(compat_int_t *)src;
 891
 892         if (v > 0)
 893                 v += xt_compat_calc_jump(AF_INET6, v);
 894         memcpy(dst, &v, sizeof(v));
 895 }
 896
 897 static int compat_standard_to_user(void __user *dst, const void *src)
 898 {
 899         compat_int_t cv = *(int *)src;
 900
 901         if (cv > 0)
 902                 cv -= xt_compat_calc_jump(AF_INET6, cv);
 903         return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
 904 }
 905
 906 static int compat_calc_entry(const struct ip6t_entry *e,
 907                              const struct xt_table_info *info,
 908                              const void *base, struct xt_table_info *newinfo)
 909 {
 910         const struct xt_entry_match *ematch;
 911         const struct xt_entry_target *t;
 912         unsigned int entry_offset;
 913         int off, i, ret;
 914
 915         off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
 916         entry_offset = (void *)e - base;
 917         xt_ematch_foreach(ematch, e)
 918                 off += xt_compat_match_offset(ematch->u.kernel.match);
 919         t = ip6t_get_target_c(e);
 920         off += xt_compat_target_offset(t->u.kernel.target);
 921         newinfo->size -= off;
 922         ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
 923         if (ret)
 924                 return ret;
 925
 926         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 927                 if (info->hook_entry[i] &&
 928                     (e < (struct ip6t_entry *)(base + info->hook_entry[i])))
 929                         newinfo->hook_entry[i] -= off;
 930                 if (info->underflow[i] &&
 931                     (e < (struct ip6t_entry *)(base + info->underflow[i])))
 932                         newinfo->underflow[i] -= off;
 933         }
 934         return 0;
 935 }
 936
 937 static int compat_table_info(const struct xt_table_info *info,
 938                              struct xt_table_info *newinfo)
 939 {
 940         struct ip6t_entry *iter;
 941         const void *loc_cpu_entry;
 942         int ret;
 943
 944         if (!newinfo || !info)
 945                 return -EINVAL;
 946
 947         /* we dont care about newinfo->entries */
 948         memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
 949         newinfo->initial_entries = 0;
 950         loc_cpu_entry = info->entries;
 951         ret = xt_compat_init_offsets(AF_INET6, info->number);
 952         if (ret)
 953                 return ret;
 954         xt_entry_foreach(iter, loc_cpu_entry, info->size) {
 955                 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
 956                 if (ret != 0)
 957                         return ret;
 958         }
 959         return 0;
 960 }
 961 #endif
 962
 963 static int get_info(struct net *net, void __user *user,
 964                     const int *len, int compat)
 965 {
 966         char name[XT_TABLE_MAXNAMELEN];
 967         struct xt_table *t;
 968         int ret;
 969
 970         if (*len != sizeof(struct ip6t_getinfo))
 971                 return -EINVAL;
 972
 973         if (copy_from_user(name, user, sizeof(name)) != 0)
 974                 return -EFAULT;
 975
 976         name[XT_TABLE_MAXNAMELEN-1] = '\0';
 977 #ifdef CONFIG_COMPAT
 978         if (compat)
 979                 xt_compat_lock(AF_INET6);
 980 #endif
 981         t = xt_request_find_table_lock(net, AF_INET6, name);
 982         if (!IS_ERR(t)) {
 983                 struct ip6t_getinfo info;
 984                 const struct xt_table_info *private = t->private;
 985 #ifdef CONFIG_COMPAT
 986                 struct xt_table_info tmp;
 987
 988                 if (compat) {
 989                         ret = compat_table_info(private, &tmp);
 990                         xt_compat_flush_offsets(AF_INET6);
 991                         private = &tmp;
 992                 }
 993 #endif
 994                 memset(&info, 0, sizeof(info));
 995                 info.valid_hooks = t->valid_hooks;
 996                 memcpy(info.hook_entry, private->hook_entry,
 997                        sizeof(info.hook_entry));
 998                 memcpy(info.underflow, private->underflow,
 999                        sizeof(info.underflow));
1000                 info.num_entries = private->number;
1001                 info.size = private->size;
1002                 strcpy(info.name, name);
1003
1004                 if (copy_to_user(user, &info, *len) != 0)
1005                         ret = -EFAULT;
1006                 else
1007                         ret = 0;
1008
1009                 xt_table_unlock(t);
1010                 module_put(t->me);
1011         } else
1012                 ret = PTR_ERR(t);
1013 #ifdef CONFIG_COMPAT
1014         if (compat)
1015                 xt_compat_unlock(AF_INET6);
1016 #endif
1017         return ret;
1018 }
1019
1020 static int
1021 get_entries(struct net *net, struct ip6t_get_entries __user *uptr,
1022             const int *len)
1023 {
1024         int ret;
1025         struct ip6t_get_entries get;
1026         struct xt_table *t;
1027
1028         if (*len < sizeof(get))
1029                 return -EINVAL;
1030         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1031                 return -EFAULT;
1032         if (*len != sizeof(struct ip6t_get_entries) + get.size)
1033                 return -EINVAL;
1034
1035         get.name[sizeof(get.name) - 1] = '\0';
1036
1037         t = xt_find_table_lock(net, AF_INET6, get.name);
1038         if (!IS_ERR(t)) {
1039                 struct xt_table_info *private = t->private;
1040                 if (get.size == private->size)
1041                         ret = copy_entries_to_user(private->size,
1042                                                    t, uptr->entrytable);
1043                 else
1044                         ret = -EAGAIN;
1045
1046                 module_put(t->me);
1047                 xt_table_unlock(t);
1048         } else
1049                 ret = PTR_ERR(t);
1050
1051         return ret;
1052 }
1053
1054 static int
1055 __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1056              struct xt_table_info *newinfo, unsigned int num_counters,
1057              void __user *counters_ptr)
1058 {
1059         int ret;
1060         struct xt_table *t;
1061         struct xt_table_info *oldinfo;
1062         struct xt_counters *counters;
1063         struct ip6t_entry *iter;
1064
1065         ret = 0;
1066         counters = xt_counters_alloc(num_counters);
1067         if (!counters) {
1068                 ret = -ENOMEM;
1069                 goto out;
1070         }
1071
1072         t = xt_request_find_table_lock(net, AF_INET6, name);
1073         if (IS_ERR(t)) {
1074                 ret = PTR_ERR(t);
1075                 goto free_newinfo_counters_untrans;
1076         }
1077
1078         /* You lied! */
1079         if (valid_hooks != t->valid_hooks) {
1080                 ret = -EINVAL;
1081                 goto put_module;
1082         }
1083
1084         oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1085         if (!oldinfo)
1086                 goto put_module;
1087
1088         /* Update module usage count based on number of rules */
1089         if ((oldinfo->number > oldinfo->initial_entries) ||
1090             (newinfo->number <= oldinfo->initial_entries))
1091                 module_put(t->me);
1092         if ((oldinfo->number > oldinfo->initial_entries) &&
1093             (newinfo->number <= oldinfo->initial_entries))
1094                 module_put(t->me);
1095
1096         xt_table_unlock(t);
1097
1098         get_old_counters(oldinfo, counters);
1099
1100         /* Decrease module usage counts and free resource */
1101         xt_entry_foreach(iter, oldinfo->entries, oldinfo->size)
1102                 cleanup_entry(iter, net);
1103
1104         xt_free_table_info(oldinfo);
1105         if (copy_to_user(counters_ptr, counters,
1106                          sizeof(struct xt_counters) * num_counters) != 0) {
1107                 /* Silent error, can't fail, new table is already in place */
1108                 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n");
1109         }
1110         vfree(counters);
1111         return ret;
1112
1113  put_module:
1114         module_put(t->me);
1115         xt_table_unlock(t);
1116  free_newinfo_counters_untrans:
1117         vfree(counters);
1118  out:
1119         return ret;
1120 }
1121
1122 static int
1123 do_replace(struct net *net, const void __user *user, unsigned int len)
1124 {
1125         int ret;
1126         struct ip6t_replace tmp;
1127         struct xt_table_info *newinfo;
1128         void *loc_cpu_entry;
1129         struct ip6t_entry *iter;
1130
1131         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1132                 return -EFAULT;
1133
1134         /* overflow check */
1135         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1136                 return -ENOMEM;
1137         if (tmp.num_counters == 0)
1138                 return -EINVAL;
1139
1140         tmp.name[sizeof(tmp.name)-1] = 0;
1141
1142         newinfo = xt_alloc_table_info(tmp.size);
1143         if (!newinfo)
1144                 return -ENOMEM;
1145
1146         loc_cpu_entry = newinfo->entries;
1147         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1148                            tmp.size) != 0) {
1149                 ret = -EFAULT;
1150                 goto free_newinfo;
1151         }
1152
1153         ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
1154         if (ret != 0)
1155                 goto free_newinfo;
1156
1157         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1158                            tmp.num_counters, tmp.counters);
1159         if (ret)
1160                 goto free_newinfo_untrans;
1161         return 0;
1162
1163  free_newinfo_untrans:
1164         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1165                 cleanup_entry(iter, net);
1166  free_newinfo:
1167         xt_free_table_info(newinfo);
1168         return ret;
1169 }
1170
1171 static int
1172 do_add_counters(struct net *net, const void __user *user, unsigned int len,
1173                 int compat)
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_from_user(user, len, &tmp, compat);
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_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[0];
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         newinfo->number = compatr->num_entries;
1449         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1450                 newinfo->hook_entry[i] = compatr->hook_entry[i];
1451                 newinfo->underflow[i] = compatr->underflow[i];
1452         }
1453         entry1 = newinfo->entries;
1454         pos = entry1;
1455         size = compatr->size;
1456         xt_entry_foreach(iter0, entry0, compatr->size)
1457                 compat_copy_entry_from_user(iter0, &pos, &size,
1458                                             newinfo, entry1);
1459
1460         /* all module references in entry0 are now gone. */
1461         xt_compat_flush_offsets(AF_INET6);
1462         xt_compat_unlock(AF_INET6);
1463
1464         memcpy(&repl, compatr, sizeof(*compatr));
1465
1466         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1467                 repl.hook_entry[i] = newinfo->hook_entry[i];
1468                 repl.underflow[i] = newinfo->underflow[i];
1469         }
1470
1471         repl.num_counters = 0;
1472         repl.counters = NULL;
1473         repl.size = newinfo->size;
1474         ret = translate_table(net, newinfo, entry1, &repl);
1475         if (ret)
1476                 goto free_newinfo;
1477
1478         *pinfo = newinfo;
1479         *pentry0 = entry1;
1480         xt_free_table_info(info);
1481         return 0;
1482
1483 free_newinfo:
1484         xt_free_table_info(newinfo);
1485         return ret;
1486 out_unlock:
1487         xt_compat_flush_offsets(AF_INET6);
1488         xt_compat_unlock(AF_INET6);
1489         xt_entry_foreach(iter0, entry0, compatr->size) {
1490                 if (j-- == 0)
1491                         break;
1492                 compat_release_entry(iter0);
1493         }
1494         return ret;
1495 }
1496
1497 static int
1498 compat_do_replace(struct net *net, void __user *user, unsigned int len)
1499 {
1500         int ret;
1501         struct compat_ip6t_replace tmp;
1502         struct xt_table_info *newinfo;
1503         void *loc_cpu_entry;
1504         struct ip6t_entry *iter;
1505
1506         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1507                 return -EFAULT;
1508
1509         /* overflow check */
1510         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1511                 return -ENOMEM;
1512         if (tmp.num_counters == 0)
1513                 return -EINVAL;
1514
1515         tmp.name[sizeof(tmp.name)-1] = 0;
1516
1517         newinfo = xt_alloc_table_info(tmp.size);
1518         if (!newinfo)
1519                 return -ENOMEM;
1520
1521         loc_cpu_entry = newinfo->entries;
1522         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1523                            tmp.size) != 0) {
1524                 ret = -EFAULT;
1525                 goto free_newinfo;
1526         }
1527
1528         ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp);
1529         if (ret != 0)
1530                 goto free_newinfo;
1531
1532         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1533                            tmp.num_counters, compat_ptr(tmp.counters));
1534         if (ret)
1535                 goto free_newinfo_untrans;
1536         return 0;
1537
1538  free_newinfo_untrans:
1539         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1540                 cleanup_entry(iter, net);
1541  free_newinfo:
1542         xt_free_table_info(newinfo);
1543         return ret;
1544 }
1545
1546 static int
1547 compat_do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user,
1548                        unsigned int len)
1549 {
1550         int ret;
1551
1552         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1553                 return -EPERM;
1554
1555         switch (cmd) {
1556         case IP6T_SO_SET_REPLACE:
1557                 ret = compat_do_replace(sock_net(sk), user, len);
1558                 break;
1559
1560         case IP6T_SO_SET_ADD_COUNTERS:
1561                 ret = do_add_counters(sock_net(sk), user, len, 1);
1562                 break;
1563
1564         default:
1565                 ret = -EINVAL;
1566         }
1567
1568         return ret;
1569 }
1570
1571 struct compat_ip6t_get_entries {
1572         char name[XT_TABLE_MAXNAMELEN];
1573         compat_uint_t size;
1574         struct compat_ip6t_entry entrytable[0];
1575 };
1576
1577 static int
1578 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1579                             void __user *userptr)
1580 {
1581         struct xt_counters *counters;
1582         const struct xt_table_info *private = table->private;
1583         void __user *pos;
1584         unsigned int size;
1585         int ret = 0;
1586         unsigned int i = 0;
1587         struct ip6t_entry *iter;
1588
1589         counters = alloc_counters(table);
1590         if (IS_ERR(counters))
1591                 return PTR_ERR(counters);
1592
1593         pos = userptr;
1594         size = total_size;
1595         xt_entry_foreach(iter, private->entries, total_size) {
1596                 ret = compat_copy_entry_to_user(iter, &pos,
1597                                                 &size, counters, i++);
1598                 if (ret != 0)
1599                         break;
1600         }
1601
1602         vfree(counters);
1603         return ret;
1604 }
1605
1606 static int
1607 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr,
1608                    int *len)
1609 {
1610         int ret;
1611         struct compat_ip6t_get_entries get;
1612         struct xt_table *t;
1613
1614         if (*len < sizeof(get))
1615                 return -EINVAL;
1616
1617         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1618                 return -EFAULT;
1619
1620         if (*len != sizeof(struct compat_ip6t_get_entries) + get.size)
1621                 return -EINVAL;
1622
1623         get.name[sizeof(get.name) - 1] = '\0';
1624
1625         xt_compat_lock(AF_INET6);
1626         t = xt_find_table_lock(net, AF_INET6, get.name);
1627         if (!IS_ERR(t)) {
1628                 const struct xt_table_info *private = t->private;
1629                 struct xt_table_info info;
1630                 ret = compat_table_info(private, &info);
1631                 if (!ret && get.size == info.size)
1632                         ret = compat_copy_entries_to_user(private->size,
1633                                                           t, uptr->entrytable);
1634                 else if (!ret)
1635                         ret = -EAGAIN;
1636
1637                 xt_compat_flush_offsets(AF_INET6);
1638                 module_put(t->me);
1639                 xt_table_unlock(t);
1640         } else
1641                 ret = PTR_ERR(t);
1642
1643         xt_compat_unlock(AF_INET6);
1644         return ret;
1645 }
1646
1647 static int do_ip6t_get_ctl(struct sock *, int, void __user *, int *);
1648
1649 static int
1650 compat_do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1651 {
1652         int ret;
1653
1654         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1655                 return -EPERM;
1656
1657         switch (cmd) {
1658         case IP6T_SO_GET_INFO:
1659                 ret = get_info(sock_net(sk), user, len, 1);
1660                 break;
1661         case IP6T_SO_GET_ENTRIES:
1662                 ret = compat_get_entries(sock_net(sk), user, len);
1663                 break;
1664         default:
1665                 ret = do_ip6t_get_ctl(sk, cmd, user, len);
1666         }
1667         return ret;
1668 }
1669 #endif
1670
1671 static int
1672 do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1673 {
1674         int ret;
1675
1676         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1677                 return -EPERM;
1678
1679         switch (cmd) {
1680         case IP6T_SO_SET_REPLACE:
1681                 ret = do_replace(sock_net(sk), user, len);
1682                 break;
1683
1684         case IP6T_SO_SET_ADD_COUNTERS:
1685                 ret = do_add_counters(sock_net(sk), user, len, 0);
1686                 break;
1687
1688         default:
1689                 ret = -EINVAL;
1690         }
1691
1692         return ret;
1693 }
1694
1695 static int
1696 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1697 {
1698         int ret;
1699
1700         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1701                 return -EPERM;
1702
1703         switch (cmd) {
1704         case IP6T_SO_GET_INFO:
1705                 ret = get_info(sock_net(sk), user, len, 0);
1706                 break;
1707
1708         case IP6T_SO_GET_ENTRIES:
1709                 ret = get_entries(sock_net(sk), user, len);
1710                 break;
1711
1712         case IP6T_SO_GET_REVISION_MATCH:
1713         case IP6T_SO_GET_REVISION_TARGET: {
1714                 struct xt_get_revision rev;
1715                 int target;
1716
1717                 if (*len != sizeof(rev)) {
1718                         ret = -EINVAL;
1719                         break;
1720                 }
1721                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1722                         ret = -EFAULT;
1723                         break;
1724                 }
1725                 rev.name[sizeof(rev.name)-1] = 0;
1726
1727                 if (cmd == IP6T_SO_GET_REVISION_TARGET)
1728                         target = 1;
1729                 else
1730                         target = 0;
1731
1732                 try_then_request_module(xt_find_revision(AF_INET6, rev.name,
1733                                                          rev.revision,
1734                                                          target, &ret),
1735                                         "ip6t_%s", rev.name);
1736                 break;
1737         }
1738
1739         default:
1740                 ret = -EINVAL;
1741         }
1742
1743         return ret;
1744 }
1745
1746 static void __ip6t_unregister_table(struct net *net, struct xt_table *table)
1747 {
1748         struct xt_table_info *private;
1749         void *loc_cpu_entry;
1750         struct module *table_owner = table->me;
1751         struct ip6t_entry *iter;
1752
1753         private = xt_unregister_table(table);
1754
1755         /* Decrease module usage counts and free resources */
1756         loc_cpu_entry = private->entries;
1757         xt_entry_foreach(iter, loc_cpu_entry, private->size)
1758                 cleanup_entry(iter, net);
1759         if (private->number > private->initial_entries)
1760                 module_put(table_owner);
1761         xt_free_table_info(private);
1762 }
1763
1764 int ip6t_register_table(struct net *net, const struct xt_table *table,
1765                         const struct ip6t_replace *repl,
1766                         const struct nf_hook_ops *ops,
1767                         struct xt_table **res)
1768 {
1769         int ret;
1770         struct xt_table_info *newinfo;
1771         struct xt_table_info bootstrap = {0};
1772         void *loc_cpu_entry;
1773         struct xt_table *new_table;
1774
1775         newinfo = xt_alloc_table_info(repl->size);
1776         if (!newinfo)
1777                 return -ENOMEM;
1778
1779         loc_cpu_entry = newinfo->entries;
1780         memcpy(loc_cpu_entry, repl->entries, repl->size);
1781
1782         ret = translate_table(net, newinfo, loc_cpu_entry, repl);
1783         if (ret != 0)
1784                 goto out_free;
1785
1786         new_table = xt_register_table(net, table, &bootstrap, newinfo);
1787         if (IS_ERR(new_table)) {
1788                 ret = PTR_ERR(new_table);
1789                 goto out_free;
1790         }
1791
1792         /* set res now, will see skbs right after nf_register_net_hooks */
1793         WRITE_ONCE(*res, new_table);
1794         if (!ops)
1795                 return 0;
1796
1797         ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1798         if (ret != 0) {
1799                 __ip6t_unregister_table(net, new_table);
1800                 *res = NULL;
1801         }
1802
1803         return ret;
1804
1805 out_free:
1806         xt_free_table_info(newinfo);
1807         return ret;
1808 }
1809
1810 void ip6t_unregister_table(struct net *net, struct xt_table *table,
1811                            const struct nf_hook_ops *ops)
1812 {
1813         if (ops)
1814                 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1815         __ip6t_unregister_table(net, table);
1816 }
1817
1818 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
1819 static inline bool
1820 icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
1821                      u_int8_t type, u_int8_t code,
1822                      bool invert)
1823 {
1824         return (type == test_type && code >= min_code && code <= max_code)
1825                 ^ invert;
1826 }
1827
1828 static bool
1829 icmp6_match(const struct sk_buff *skb, struct xt_action_param *par)
1830 {
1831         const struct icmp6hdr *ic;
1832         struct icmp6hdr _icmph;
1833         const struct ip6t_icmp *icmpinfo = par->matchinfo;
1834
1835         /* Must not be a fragment. */
1836         if (par->fragoff != 0)
1837                 return false;
1838
1839         ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
1840         if (ic == NULL) {
1841                 /* We've been asked to examine this packet, and we
1842                  * can't.  Hence, no choice but to drop.
1843                  */
1844                 par->hotdrop = true;
1845                 return false;
1846         }
1847
1848         return icmp6_type_code_match(icmpinfo->type,
1849                                      icmpinfo->code[0],
1850                                      icmpinfo->code[1],
1851                                      ic->icmp6_type, ic->icmp6_code,
1852                                      !!(icmpinfo->invflags&IP6T_ICMP_INV));
1853 }
1854
1855 /* Called when user tries to insert an entry of this type. */
1856 static int icmp6_checkentry(const struct xt_mtchk_param *par)
1857 {
1858         const struct ip6t_icmp *icmpinfo = par->matchinfo;
1859
1860         /* Must specify no unknown invflags */
1861         return (icmpinfo->invflags & ~IP6T_ICMP_INV) ? -EINVAL : 0;
1862 }
1863
1864 /* The built-in targets: standard (NULL) and error. */
1865 static struct xt_target ip6t_builtin_tg[] __read_mostly = {
1866         {
1867                 .name             = XT_STANDARD_TARGET,
1868                 .targetsize       = sizeof(int),
1869                 .family           = NFPROTO_IPV6,
1870 #ifdef CONFIG_COMPAT
1871                 .compatsize       = sizeof(compat_int_t),
1872                 .compat_from_user = compat_standard_from_user,
1873                 .compat_to_user   = compat_standard_to_user,
1874 #endif
1875         },
1876         {
1877                 .name             = XT_ERROR_TARGET,
1878                 .target           = ip6t_error,
1879                 .targetsize       = XT_FUNCTION_MAXNAMELEN,
1880                 .family           = NFPROTO_IPV6,
1881         },
1882 };
1883
1884 static struct nf_sockopt_ops ip6t_sockopts = {
1885         .pf             = PF_INET6,
1886         .set_optmin     = IP6T_BASE_CTL,
1887         .set_optmax     = IP6T_SO_SET_MAX+1,
1888         .set            = do_ip6t_set_ctl,
1889 #ifdef CONFIG_COMPAT
1890         .compat_set     = compat_do_ip6t_set_ctl,
1891 #endif
1892         .get_optmin     = IP6T_BASE_CTL,
1893         .get_optmax     = IP6T_SO_GET_MAX+1,
1894         .get            = do_ip6t_get_ctl,
1895 #ifdef CONFIG_COMPAT
1896         .compat_get     = compat_do_ip6t_get_ctl,
1897 #endif
1898         .owner          = THIS_MODULE,
1899 };
1900
1901 static struct xt_match ip6t_builtin_mt[] __read_mostly = {
1902         {
1903                 .name       = "icmp6",
1904                 .match      = icmp6_match,
1905                 .matchsize  = sizeof(struct ip6t_icmp),
1906                 .checkentry = icmp6_checkentry,
1907                 .proto      = IPPROTO_ICMPV6,
1908                 .family     = NFPROTO_IPV6,
1909                 .me         = THIS_MODULE,
1910         },
1911 };
1912
1913 static int __net_init ip6_tables_net_init(struct net *net)
1914 {
1915         return xt_proto_init(net, NFPROTO_IPV6);
1916 }
1917
1918 static void __net_exit ip6_tables_net_exit(struct net *net)
1919 {
1920         xt_proto_fini(net, NFPROTO_IPV6);
1921 }
1922
1923 static struct pernet_operations ip6_tables_net_ops = {
1924         .init = ip6_tables_net_init,
1925         .exit = ip6_tables_net_exit,
1926 };
1927
1928 static int __init ip6_tables_init(void)
1929 {
1930         int ret;
1931
1932         ret = register_pernet_subsys(&ip6_tables_net_ops);
1933         if (ret < 0)
1934                 goto err1;
1935
1936         /* No one else will be downing sem now, so we won't sleep */
1937         ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1938         if (ret < 0)
1939                 goto err2;
1940         ret = xt_register_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
1941         if (ret < 0)
1942                 goto err4;
1943
1944         /* Register setsockopt */
1945         ret = nf_register_sockopt(&ip6t_sockopts);
1946         if (ret < 0)
1947                 goto err5;
1948
1949         return 0;
1950
1951 err5:
1952         xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
1953 err4:
1954         xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1955 err2:
1956         unregister_pernet_subsys(&ip6_tables_net_ops);
1957 err1:
1958         return ret;
1959 }
1960
1961 static void __exit ip6_tables_fini(void)
1962 {
1963         nf_unregister_sockopt(&ip6t_sockopts);
1964
1965         xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
1966         xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1967         unregister_pernet_subsys(&ip6_tables_net_ops);
1968 }
1969
1970 EXPORT_SYMBOL(ip6t_register_table);
1971 EXPORT_SYMBOL(ip6t_unregister_table);
1972 EXPORT_SYMBOL(ip6t_do_table);
1973
1974 module_init(ip6_tables_init);
1975 module_exit(ip6_tables_fini);