net/ipv6/netfilter/ip6_tables.c

   1 /*
   2  * Packet matching code.
   3  *
   4  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
   5  * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
   6  * Copyright (c) 2006-2010 Patrick McHardy <kaber@trash.net>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/kernel.h>
  16 #include <linux/capability.h>
  17 #include <linux/in.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/kmod.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/netdevice.h>
  22 #include <linux/module.h>
  23 #include <linux/poison.h>
  24 #include <linux/icmpv6.h>
  25 #include <net/ipv6.h>
  26 #include <net/compat.h>
  27 #include <asm/uaccess.h>
  28 #include <linux/mutex.h>
  29 #include <linux/proc_fs.h>
  30 #include <linux/err.h>
  31 #include <linux/cpumask.h>
  32
  33 #include <linux/netfilter_ipv6/ip6_tables.h>
  34 #include <linux/netfilter/x_tables.h>
  35 #include <net/netfilter/nf_log.h>
  36 #include "../../netfilter/xt_repldata.h"
  37
  38 MODULE_LICENSE("GPL");
  39 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  40 MODULE_DESCRIPTION("IPv6 packet filter");
  41
  42 /*#define DEBUG_IP_FIREWALL*/
  43 /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
  44 /*#define DEBUG_IP_FIREWALL_USER*/
  45
  46 #ifdef DEBUG_IP_FIREWALL
  47 #define dprintf(format, args...) pr_info(format , ## args)
  48 #else
  49 #define dprintf(format, args...)
  50 #endif
  51
  52 #ifdef DEBUG_IP_FIREWALL_USER
  53 #define duprintf(format, args...) pr_info(format , ## args)
  54 #else
  55 #define duprintf(format, args...)
  56 #endif
  57
  58 #ifdef CONFIG_NETFILTER_DEBUG
  59 #define IP_NF_ASSERT(x) WARN_ON(!(x))
  60 #else
  61 #define IP_NF_ASSERT(x)
  62 #endif
  63
  64 #if 0
  65 /* All the better to debug you with... */
  66 #define static
  67 #define inline
  68 #endif
  69
  70 void *ip6t_alloc_initial_table(const struct xt_table *info)
  71 {
  72         return xt_alloc_initial_table(ip6t, IP6T);
  73 }
  74 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table);
  75
  76 /*
  77    We keep a set of rules for each CPU, so we can avoid write-locking
  78    them in the softirq when updating the counters and therefore
  79    only need to read-lock in the softirq; doing a write_lock_bh() in user
  80    context stops packets coming through and allows user context to read
  81    the counters or update the rules.
  82
  83    Hence the start of any table is given by get_table() below.  */
  84
  85 /* Returns whether matches rule or not. */
  86 /* Performance critical - called for every packet */
  87 static inline bool
  88 ip6_packet_match(const struct sk_buff *skb,
  89                  const char *indev,
  90                  const char *outdev,
  91                  const struct ip6t_ip6 *ip6info,
  92                  unsigned int *protoff,
  93                  int *fragoff, bool *hotdrop)
  94 {
  95         unsigned long ret;
  96         const struct ipv6hdr *ipv6 = ipv6_hdr(skb);
  97
  98 #define FWINV(bool, invflg) ((bool) ^ !!(ip6info->invflags & (invflg)))
  99
 100         if (FWINV(ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk,
 101                                        &ip6info->src), IP6T_INV_SRCIP) ||
 102             FWINV(ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk,
 103                                        &ip6info->dst), IP6T_INV_DSTIP)) {
 104                 dprintf("Source or dest mismatch.\n");
 105 /*
 106                 dprintf("SRC: %u. Mask: %u. Target: %u.%s\n", ip->saddr,
 107                         ipinfo->smsk.s_addr, ipinfo->src.s_addr,
 108                         ipinfo->invflags & IP6T_INV_SRCIP ? " (INV)" : "");
 109                 dprintf("DST: %u. Mask: %u. Target: %u.%s\n", ip->daddr,
 110                         ipinfo->dmsk.s_addr, ipinfo->dst.s_addr,
 111                         ipinfo->invflags & IP6T_INV_DSTIP ? " (INV)" : "");*/
 112                 return false;
 113         }
 114
 115         ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask);
 116
 117         if (FWINV(ret != 0, IP6T_INV_VIA_IN)) {
 118                 dprintf("VIA in mismatch (%s vs %s).%s\n",
 119                         indev, ip6info->iniface,
 120                         ip6info->invflags & IP6T_INV_VIA_IN ? " (INV)" : "");
 121                 return false;
 122         }
 123
 124         ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask);
 125
 126         if (FWINV(ret != 0, IP6T_INV_VIA_OUT)) {
 127                 dprintf("VIA out mismatch (%s vs %s).%s\n",
 128                         outdev, ip6info->outiface,
 129                         ip6info->invflags & IP6T_INV_VIA_OUT ? " (INV)" : "");
 130                 return false;
 131         }
 132
 133 /* ... might want to do something with class and flowlabel here ... */
 134
 135         /* look for the desired protocol header */
 136         if (ip6info->flags & IP6T_F_PROTO) {
 137                 int protohdr;
 138                 unsigned short _frag_off;
 139
 140                 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL);
 141                 if (protohdr < 0) {
 142                         if (_frag_off == 0)
 143                                 *hotdrop = true;
 144                         return false;
 145                 }
 146                 *fragoff = _frag_off;
 147
 148                 dprintf("Packet protocol %hi ?= %s%hi.\n",
 149                                 protohdr,
 150                                 ip6info->invflags & IP6T_INV_PROTO ? "!":"",
 151                                 ip6info->proto);
 152
 153                 if (ip6info->proto == protohdr) {
 154                         if (ip6info->invflags & IP6T_INV_PROTO)
 155                                 return false;
 156
 157                         return true;
 158                 }
 159
 160                 /* We need match for the '-p all', too! */
 161                 if ((ip6info->proto != 0) &&
 162                         !(ip6info->invflags & IP6T_INV_PROTO))
 163                         return false;
 164         }
 165         return true;
 166 }
 167
 168 /* should be ip6 safe */
 169 static bool
 170 ip6_checkentry(const struct ip6t_ip6 *ipv6)
 171 {
 172         if (ipv6->flags & ~IP6T_F_MASK) {
 173                 duprintf("Unknown flag bits set: %08X\n",
 174                          ipv6->flags & ~IP6T_F_MASK);
 175                 return false;
 176         }
 177         if (ipv6->invflags & ~IP6T_INV_MASK) {
 178                 duprintf("Unknown invflag bits set: %08X\n",
 179                          ipv6->invflags & ~IP6T_INV_MASK);
 180                 return false;
 181         }
 182         return true;
 183 }
 184
 185 static unsigned int
 186 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par)
 187 {
 188         net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);
 189
 190         return NF_DROP;
 191 }
 192
 193 static inline struct ip6t_entry *
 194 get_entry(const void *base, unsigned int offset)
 195 {
 196         return (struct ip6t_entry *)(base + offset);
 197 }
 198
 199 /* All zeroes == unconditional rule. */
 200 /* Mildly perf critical (only if packet tracing is on) */
 201 static inline bool unconditional(const struct ip6t_entry *e)
 202 {
 203         static const struct ip6t_ip6 uncond;
 204
 205         return e->target_offset == sizeof(struct ip6t_entry) &&
 206                memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0;
 207 }
 208
 209 static inline const struct xt_entry_target *
 210 ip6t_get_target_c(const struct ip6t_entry *e)
 211 {
 212         return ip6t_get_target((struct ip6t_entry *)e);
 213 }
 214
 215 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
 216 /* This cries for unification! */
 217 static const char *const hooknames[] = {
 218         [NF_INET_PRE_ROUTING]           = "PREROUTING",
 219         [NF_INET_LOCAL_IN]              = "INPUT",
 220         [NF_INET_FORWARD]               = "FORWARD",
 221         [NF_INET_LOCAL_OUT]             = "OUTPUT",
 222         [NF_INET_POST_ROUTING]          = "POSTROUTING",
 223 };
 224
 225 enum nf_ip_trace_comments {
 226         NF_IP6_TRACE_COMMENT_RULE,
 227         NF_IP6_TRACE_COMMENT_RETURN,
 228         NF_IP6_TRACE_COMMENT_POLICY,
 229 };
 230
 231 static const char *const comments[] = {
 232         [NF_IP6_TRACE_COMMENT_RULE]     = "rule",
 233         [NF_IP6_TRACE_COMMENT_RETURN]   = "return",
 234         [NF_IP6_TRACE_COMMENT_POLICY]   = "policy",
 235 };
 236
 237 static struct nf_loginfo trace_loginfo = {
 238         .type = NF_LOG_TYPE_LOG,
 239         .u = {
 240                 .log = {
 241                         .level = LOGLEVEL_WARNING,
 242                         .logflags = NF_LOG_MASK,
 243                 },
 244         },
 245 };
 246
 247 /* Mildly perf critical (only if packet tracing is on) */
 248 static inline int
 249 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e,
 250                       const char *hookname, const char **chainname,
 251                       const char **comment, unsigned int *rulenum)
 252 {
 253         const struct xt_standard_target *t = (void *)ip6t_get_target_c(s);
 254
 255         if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
 256                 /* Head of user chain: ERROR target with chainname */
 257                 *chainname = t->target.data;
 258                 (*rulenum) = 0;
 259         } else if (s == e) {
 260                 (*rulenum)++;
 261
 262                 if (unconditional(s) &&
 263                     strcmp(t->target.u.kernel.target->name,
 264                            XT_STANDARD_TARGET) == 0 &&
 265                     t->verdict < 0) {
 266                         /* Tail of chains: STANDARD target (return/policy) */
 267                         *comment = *chainname == hookname
 268                                 ? comments[NF_IP6_TRACE_COMMENT_POLICY]
 269                                 : comments[NF_IP6_TRACE_COMMENT_RETURN];
 270                 }
 271                 return 1;
 272         } else
 273                 (*rulenum)++;
 274
 275         return 0;
 276 }
 277
 278 static void trace_packet(struct net *net,
 279                          const struct sk_buff *skb,
 280                          unsigned int hook,
 281                          const struct net_device *in,
 282                          const struct net_device *out,
 283                          const char *tablename,
 284                          const struct xt_table_info *private,
 285                          const struct ip6t_entry *e)
 286 {
 287         const struct ip6t_entry *root;
 288         const char *hookname, *chainname, *comment;
 289         const struct ip6t_entry *iter;
 290         unsigned int rulenum = 0;
 291
 292         root = get_entry(private->entries, private->hook_entry[hook]);
 293
 294         hookname = chainname = hooknames[hook];
 295         comment = comments[NF_IP6_TRACE_COMMENT_RULE];
 296
 297         xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
 298                 if (get_chainname_rulenum(iter, e, hookname,
 299                     &chainname, &comment, &rulenum) != 0)
 300                         break;
 301
 302         nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
 303                      "TRACE: %s:%s:%s:%u ",
 304                      tablename, chainname, comment, rulenum);
 305 }
 306 #endif
 307
 308 static inline struct ip6t_entry *
 309 ip6t_next_entry(const struct ip6t_entry *entry)
 310 {
 311         return (void *)entry + entry->next_offset;
 312 }
 313
 314 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
 315 unsigned int
 316 ip6t_do_table(struct sk_buff *skb,
 317               const struct nf_hook_state *state,
 318               struct xt_table *table)
 319 {
 320         unsigned int hook = state->hook;
 321         static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
 322         /* Initializing verdict to NF_DROP keeps gcc happy. */
 323         unsigned int verdict = NF_DROP;
 324         const char *indev, *outdev;
 325         const void *table_base;
 326         struct ip6t_entry *e, **jumpstack;
 327         unsigned int stackidx, cpu;
 328         const struct xt_table_info *private;
 329         struct xt_action_param acpar;
 330         unsigned int addend;
 331
 332         /* Initialization */
 333         stackidx = 0;
 334         indev = state->in ? state->in->name : nulldevname;
 335         outdev = state->out ? state->out->name : nulldevname;
 336         /* We handle fragments by dealing with the first fragment as
 337          * if it was a normal packet.  All other fragments are treated
 338          * normally, except that they will NEVER match rules that ask
 339          * things we don't know, ie. tcp syn flag or ports).  If the
 340          * rule is also a fragment-specific rule, non-fragments won't
 341          * match it. */
 342         acpar.hotdrop = false;
 343         acpar.net     = state->net;
 344         acpar.in      = state->in;
 345         acpar.out     = state->out;
 346         acpar.family  = NFPROTO_IPV6;
 347         acpar.hooknum = hook;
 348
 349         IP_NF_ASSERT(table->valid_hooks & (1 << hook));
 350
 351         local_bh_disable();
 352         addend = xt_write_recseq_begin();
 353         private = table->private;
 354         /*
 355          * Ensure we load private-> members after we've fetched the base
 356          * pointer.
 357          */
 358         smp_read_barrier_depends();
 359         cpu        = smp_processor_id();
 360         table_base = private->entries;
 361         jumpstack  = (struct ip6t_entry **)private->jumpstack[cpu];
 362
 363         /* Switch to alternate jumpstack if we're being invoked via TEE.
 364          * TEE issues XT_CONTINUE verdict on original skb so we must not
 365          * clobber the jumpstack.
 366          *
 367          * For recursion via REJECT or SYNPROXY the stack will be clobbered
 368          * but it is no problem since absolute verdict is issued by these.
 369          */
 370         if (static_key_false(&xt_tee_enabled))
 371                 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
 372
 373         e = get_entry(table_base, private->hook_entry[hook]);
 374
 375         do {
 376                 const struct xt_entry_target *t;
 377                 const struct xt_entry_match *ematch;
 378                 struct xt_counters *counter;
 379
 380                 IP_NF_ASSERT(e);
 381                 acpar.thoff = 0;
 382                 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6,
 383                     &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) {
 384  no_match:
 385                         e = ip6t_next_entry(e);
 386                         continue;
 387                 }
 388
 389                 xt_ematch_foreach(ematch, e) {
 390                         acpar.match     = ematch->u.kernel.match;
 391                         acpar.matchinfo = ematch->data;
 392                         if (!acpar.match->match(skb, &acpar))
 393                                 goto no_match;
 394                 }
 395
 396                 counter = xt_get_this_cpu_counter(&e->counters);
 397                 ADD_COUNTER(*counter, skb->len, 1);
 398
 399                 t = ip6t_get_target_c(e);
 400                 IP_NF_ASSERT(t->u.kernel.target);
 401
 402 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
 403                 /* The packet is traced: log it */
 404                 if (unlikely(skb->nf_trace))
 405                         trace_packet(state->net, skb, hook, state->in,
 406                                      state->out, table->name, private, e);
 407 #endif
 408                 /* Standard target? */
 409                 if (!t->u.kernel.target->target) {
 410                         int v;
 411
 412                         v = ((struct xt_standard_target *)t)->verdict;
 413                         if (v < 0) {
 414                                 /* Pop from stack? */
 415                                 if (v != XT_RETURN) {
 416                                         verdict = (unsigned int)(-v) - 1;
 417                                         break;
 418                                 }
 419                                 if (stackidx == 0)
 420                                         e = get_entry(table_base,
 421                                             private->underflow[hook]);
 422                                 else
 423                                         e = ip6t_next_entry(jumpstack[--stackidx]);
 424                                 continue;
 425                         }
 426                         if (table_base + v != ip6t_next_entry(e) &&
 427                             !(e->ipv6.flags & IP6T_F_GOTO)) {
 428                                 jumpstack[stackidx++] = e;
 429                         }
 430
 431                         e = get_entry(table_base, v);
 432                         continue;
 433                 }
 434
 435                 acpar.target   = t->u.kernel.target;
 436                 acpar.targinfo = t->data;
 437
 438                 verdict = t->u.kernel.target->target(skb, &acpar);
 439                 if (verdict == XT_CONTINUE)
 440                         e = ip6t_next_entry(e);
 441                 else
 442                         /* Verdict */
 443                         break;
 444         } while (!acpar.hotdrop);
 445
 446         xt_write_recseq_end(addend);
 447         local_bh_enable();
 448
 449 #ifdef DEBUG_ALLOW_ALL
 450         return NF_ACCEPT;
 451 #else
 452         if (acpar.hotdrop)
 453                 return NF_DROP;
 454         else return verdict;
 455 #endif
 456 }
 457
 458 static bool find_jump_target(const struct xt_table_info *t,
 459                              const struct ip6t_entry *target)
 460 {
 461         struct ip6t_entry *iter;
 462
 463         xt_entry_foreach(iter, t->entries, t->size) {
 464                  if (iter == target)
 465                         return true;
 466         }
 467         return false;
 468 }
 469
 470 /* Figures out from what hook each rule can be called: returns 0 if
 471    there are loops.  Puts hook bitmask in comefrom. */
 472 static int
 473 mark_source_chains(const struct xt_table_info *newinfo,
 474                    unsigned int valid_hooks, void *entry0)
 475 {
 476         unsigned int hook;
 477
 478         /* No recursion; use packet counter to save back ptrs (reset
 479            to 0 as we leave), and comefrom to save source hook bitmask */
 480         for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
 481                 unsigned int pos = newinfo->hook_entry[hook];
 482                 struct ip6t_entry *e = (struct ip6t_entry *)(entry0 + pos);
 483
 484                 if (!(valid_hooks & (1 << hook)))
 485                         continue;
 486
 487                 /* Set initial back pointer. */
 488                 e->counters.pcnt = pos;
 489
 490                 for (;;) {
 491                         const struct xt_standard_target *t
 492                                 = (void *)ip6t_get_target_c(e);
 493                         int visited = e->comefrom & (1 << hook);
 494
 495                         if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
 496                                 pr_err("iptables: loop hook %u pos %u %08X.\n",
 497                                        hook, pos, e->comefrom);
 498                                 return 0;
 499                         }
 500                         e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
 501
 502                         /* Unconditional return/END. */
 503                         if ((unconditional(e) &&
 504                              (strcmp(t->target.u.user.name,
 505                                      XT_STANDARD_TARGET) == 0) &&
 506                              t->verdict < 0) || visited) {
 507                                 unsigned int oldpos, size;
 508
 509                                 if ((strcmp(t->target.u.user.name,
 510                                             XT_STANDARD_TARGET) == 0) &&
 511                                     t->verdict < -NF_MAX_VERDICT - 1) {
 512                                         duprintf("mark_source_chains: bad "
 513                                                 "negative verdict (%i)\n",
 514                                                                 t->verdict);
 515                                         return 0;
 516                                 }
 517
 518                                 /* Return: backtrack through the last
 519                                    big jump. */
 520                                 do {
 521                                         e->comefrom ^= (1<<NF_INET_NUMHOOKS);
 522 #ifdef DEBUG_IP_FIREWALL_USER
 523                                         if (e->comefrom
 524                                             & (1 << NF_INET_NUMHOOKS)) {
 525                                                 duprintf("Back unset "
 526                                                          "on hook %u "
 527                                                          "rule %u\n",
 528                                                          hook, pos);
 529                                         }
 530 #endif
 531                                         oldpos = pos;
 532                                         pos = e->counters.pcnt;
 533                                         e->counters.pcnt = 0;
 534
 535                                         /* We're at the start. */
 536                                         if (pos == oldpos)
 537                                                 goto next;
 538
 539                                         e = (struct ip6t_entry *)
 540                                                 (entry0 + pos);
 541                                 } while (oldpos == pos + e->next_offset);
 542
 543                                 /* Move along one */
 544                                 size = e->next_offset;
 545                                 e = (struct ip6t_entry *)
 546                                         (entry0 + pos + size);
 547                                 if (pos + size >= newinfo->size)
 548                                         return 0;
 549                                 e->counters.pcnt = pos;
 550                                 pos += size;
 551                         } else {
 552                                 int newpos = t->verdict;
 553
 554                                 if (strcmp(t->target.u.user.name,
 555                                            XT_STANDARD_TARGET) == 0 &&
 556                                     newpos >= 0) {
 557                                         if (newpos > newinfo->size -
 558                                                 sizeof(struct ip6t_entry)) {
 559                                                 duprintf("mark_source_chains: "
 560                                                         "bad verdict (%i)\n",
 561                                                                 newpos);
 562                                                 return 0;
 563                                         }
 564                                         /* This a jump; chase it. */
 565                                         duprintf("Jump rule %u -> %u\n",
 566                                                  pos, newpos);
 567                                         e = (struct ip6t_entry *)
 568                                                 (entry0 + newpos);
 569                                         if (!find_jump_target(newinfo, e))
 570                                                 return 0;
 571                                 } else {
 572                                         /* ... this is a fallthru */
 573                                         newpos = pos + e->next_offset;
 574                                         if (newpos >= newinfo->size)
 575                                                 return 0;
 576                                 }
 577                                 e = (struct ip6t_entry *)
 578                                         (entry0 + newpos);
 579                                 e->counters.pcnt = pos;
 580                                 pos = newpos;
 581                         }
 582                 }
 583 next:
 584                 duprintf("Finished chain %u\n", hook);
 585         }
 586         return 1;
 587 }
 588
 589 static void cleanup_match(struct xt_entry_match *m, struct net *net)
 590 {
 591         struct xt_mtdtor_param par;
 592
 593         par.net       = net;
 594         par.match     = m->u.kernel.match;
 595         par.matchinfo = m->data;
 596         par.family    = NFPROTO_IPV6;
 597         if (par.match->destroy != NULL)
 598                 par.match->destroy(&par);
 599         module_put(par.match->me);
 600 }
 601
 602 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
 603 {
 604         const struct ip6t_ip6 *ipv6 = par->entryinfo;
 605         int ret;
 606
 607         par->match     = m->u.kernel.match;
 608         par->matchinfo = m->data;
 609
 610         ret = xt_check_match(par, m->u.match_size - sizeof(*m),
 611                              ipv6->proto, ipv6->invflags & IP6T_INV_PROTO);
 612         if (ret < 0) {
 613                 duprintf("ip_tables: check failed for `%s'.\n",
 614                          par.match->name);
 615                 return ret;
 616         }
 617         return 0;
 618 }
 619
 620 static int
 621 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
 622 {
 623         struct xt_match *match;
 624         int ret;
 625
 626         match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
 627                                       m->u.user.revision);
 628         if (IS_ERR(match)) {
 629                 duprintf("find_check_match: `%s' not found\n", m->u.user.name);
 630                 return PTR_ERR(match);
 631         }
 632         m->u.kernel.match = match;
 633
 634         ret = check_match(m, par);
 635         if (ret)
 636                 goto err;
 637
 638         return 0;
 639 err:
 640         module_put(m->u.kernel.match->me);
 641         return ret;
 642 }
 643
 644 static int check_target(struct ip6t_entry *e, struct net *net, const char *name)
 645 {
 646         struct xt_entry_target *t = ip6t_get_target(e);
 647         struct xt_tgchk_param par = {
 648                 .net       = net,
 649                 .table     = name,
 650                 .entryinfo = e,
 651                 .target    = t->u.kernel.target,
 652                 .targinfo  = t->data,
 653                 .hook_mask = e->comefrom,
 654                 .family    = NFPROTO_IPV6,
 655         };
 656         int ret;
 657
 658         t = ip6t_get_target(e);
 659         ret = xt_check_target(&par, t->u.target_size - sizeof(*t),
 660               e->ipv6.proto, e->ipv6.invflags & IP6T_INV_PROTO);
 661         if (ret < 0) {
 662                 duprintf("ip_tables: check failed for `%s'.\n",
 663                          t->u.kernel.target->name);
 664                 return ret;
 665         }
 666         return 0;
 667 }
 668
 669 static int
 670 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
 671                  unsigned int size)
 672 {
 673         struct xt_entry_target *t;
 674         struct xt_target *target;
 675         int ret;
 676         unsigned int j;
 677         struct xt_mtchk_param mtpar;
 678         struct xt_entry_match *ematch;
 679
 680         e->counters.pcnt = xt_percpu_counter_alloc();
 681         if (IS_ERR_VALUE(e->counters.pcnt))
 682                 return -ENOMEM;
 683
 684         j = 0;
 685         mtpar.net       = net;
 686         mtpar.table     = name;
 687         mtpar.entryinfo = &e->ipv6;
 688         mtpar.hook_mask = e->comefrom;
 689         mtpar.family    = NFPROTO_IPV6;
 690         xt_ematch_foreach(ematch, e) {
 691                 ret = find_check_match(ematch, &mtpar);
 692                 if (ret != 0)
 693                         goto cleanup_matches;
 694                 ++j;
 695         }
 696
 697         t = ip6t_get_target(e);
 698         target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
 699                                         t->u.user.revision);
 700         if (IS_ERR(target)) {
 701                 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
 702                 ret = PTR_ERR(target);
 703                 goto cleanup_matches;
 704         }
 705         t->u.kernel.target = target;
 706
 707         ret = check_target(e, net, name);
 708         if (ret)
 709                 goto err;
 710         return 0;
 711  err:
 712         module_put(t->u.kernel.target->me);
 713  cleanup_matches:
 714         xt_ematch_foreach(ematch, e) {
 715                 if (j-- == 0)
 716                         break;
 717                 cleanup_match(ematch, net);
 718         }
 719
 720         xt_percpu_counter_free(e->counters.pcnt);
 721
 722         return ret;
 723 }
 724
 725 static bool check_underflow(const struct ip6t_entry *e)
 726 {
 727         const struct xt_entry_target *t;
 728         unsigned int verdict;
 729
 730         if (!unconditional(e))
 731                 return false;
 732         t = ip6t_get_target_c(e);
 733         if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
 734                 return false;
 735         verdict = ((struct xt_standard_target *)t)->verdict;
 736         verdict = -verdict - 1;
 737         return verdict == NF_DROP || verdict == NF_ACCEPT;
 738 }
 739
 740 static int
 741 check_entry_size_and_hooks(struct ip6t_entry *e,
 742                            struct xt_table_info *newinfo,
 743                            const unsigned char *base,
 744                            const unsigned char *limit,
 745                            const unsigned int *hook_entries,
 746                            const unsigned int *underflows,
 747                            unsigned int valid_hooks)
 748 {
 749         unsigned int h;
 750         int err;
 751
 752         if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 ||
 753             (unsigned char *)e + sizeof(struct ip6t_entry) >= limit ||
 754             (unsigned char *)e + e->next_offset > limit) {
 755                 duprintf("Bad offset %p\n", e);
 756                 return -EINVAL;
 757         }
 758
 759         if (e->next_offset
 760             < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target)) {
 761                 duprintf("checking: element %p size %u\n",
 762                          e, e->next_offset);
 763                 return -EINVAL;
 764         }
 765
 766         if (!ip6_checkentry(&e->ipv6))
 767                 return -EINVAL;
 768
 769         err = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
 770         if (err)
 771                 return err;
 772
 773         /* Check hooks & underflows */
 774         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
 775                 if (!(valid_hooks & (1 << h)))
 776                         continue;
 777                 if ((unsigned char *)e - base == hook_entries[h])
 778                         newinfo->hook_entry[h] = hook_entries[h];
 779                 if ((unsigned char *)e - base == underflows[h]) {
 780                         if (!check_underflow(e)) {
 781                                 pr_debug("Underflows must be unconditional and "
 782                                          "use the STANDARD target with "
 783                                          "ACCEPT/DROP\n");
 784                                 return -EINVAL;
 785                         }
 786                         newinfo->underflow[h] = underflows[h];
 787                 }
 788         }
 789
 790         /* Clear counters and comefrom */
 791         e->counters = ((struct xt_counters) { 0, 0 });
 792         e->comefrom = 0;
 793         return 0;
 794 }
 795
 796 static void cleanup_entry(struct ip6t_entry *e, struct net *net)
 797 {
 798         struct xt_tgdtor_param par;
 799         struct xt_entry_target *t;
 800         struct xt_entry_match *ematch;
 801
 802         /* Cleanup all matches */
 803         xt_ematch_foreach(ematch, e)
 804                 cleanup_match(ematch, net);
 805         t = ip6t_get_target(e);
 806
 807         par.net      = net;
 808         par.target   = t->u.kernel.target;
 809         par.targinfo = t->data;
 810         par.family   = NFPROTO_IPV6;
 811         if (par.target->destroy != NULL)
 812                 par.target->destroy(&par);
 813         module_put(par.target->me);
 814
 815         xt_percpu_counter_free(e->counters.pcnt);
 816 }
 817
 818 /* Checks and translates the user-supplied table segment (held in
 819    newinfo) */
 820 static int
 821 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
 822                 const struct ip6t_replace *repl)
 823 {
 824         struct ip6t_entry *iter;
 825         unsigned int i;
 826         int ret = 0;
 827
 828         newinfo->size = repl->size;
 829         newinfo->number = repl->num_entries;
 830
 831         /* Init all hooks to impossible value. */
 832         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 833                 newinfo->hook_entry[i] = 0xFFFFFFFF;
 834                 newinfo->underflow[i] = 0xFFFFFFFF;
 835         }
 836
 837         duprintf("translate_table: size %u\n", newinfo->size);
 838         i = 0;
 839         /* Walk through entries, checking offsets. */
 840         xt_entry_foreach(iter, entry0, newinfo->size) {
 841                 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
 842                                                  entry0 + repl->size,
 843                                                  repl->hook_entry,
 844                                                  repl->underflow,
 845                                                  repl->valid_hooks);
 846                 if (ret != 0)
 847                         return ret;
 848                 ++i;
 849                 if (strcmp(ip6t_get_target(iter)->u.user.name,
 850                     XT_ERROR_TARGET) == 0)
 851                         ++newinfo->stacksize;
 852         }
 853
 854         if (i != repl->num_entries) {
 855                 duprintf("translate_table: %u not %u entries\n",
 856                          i, repl->num_entries);
 857                 return -EINVAL;
 858         }
 859
 860         /* Check hooks all assigned */
 861         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 862                 /* Only hooks which are valid */
 863                 if (!(repl->valid_hooks & (1 << i)))
 864                         continue;
 865                 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
 866                         duprintf("Invalid hook entry %u %u\n",
 867                                  i, repl->hook_entry[i]);
 868                         return -EINVAL;
 869                 }
 870                 if (newinfo->underflow[i] == 0xFFFFFFFF) {
 871                         duprintf("Invalid underflow %u %u\n",
 872                                  i, repl->underflow[i]);
 873                         return -EINVAL;
 874                 }
 875         }
 876
 877         if (!mark_source_chains(newinfo, repl->valid_hooks, entry0))
 878                 return -ELOOP;
 879
 880         /* Finally, each sanity check must pass */
 881         i = 0;
 882         xt_entry_foreach(iter, entry0, newinfo->size) {
 883                 ret = find_check_entry(iter, net, repl->name, repl->size);
 884                 if (ret != 0)
 885                         break;
 886                 ++i;
 887         }
 888
 889         if (ret != 0) {
 890                 xt_entry_foreach(iter, entry0, newinfo->size) {
 891                         if (i-- == 0)
 892                                 break;
 893                         cleanup_entry(iter, net);
 894                 }
 895                 return ret;
 896         }
 897
 898         return ret;
 899 }
 900
 901 static void
 902 get_counters(const struct xt_table_info *t,
 903              struct xt_counters counters[])
 904 {
 905         struct ip6t_entry *iter;
 906         unsigned int cpu;
 907         unsigned int i;
 908
 909         for_each_possible_cpu(cpu) {
 910                 seqcount_t *s = &per_cpu(xt_recseq, cpu);
 911
 912                 i = 0;
 913                 xt_entry_foreach(iter, t->entries, t->size) {
 914                         struct xt_counters *tmp;
 915                         u64 bcnt, pcnt;
 916                         unsigned int start;
 917
 918                         tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
 919                         do {
 920                                 start = read_seqcount_begin(s);
 921                                 bcnt = tmp->bcnt;
 922                                 pcnt = tmp->pcnt;
 923                         } while (read_seqcount_retry(s, start));
 924
 925                         ADD_COUNTER(counters[i], bcnt, pcnt);
 926                         ++i;
 927                 }
 928         }
 929 }
 930
 931 static struct xt_counters *alloc_counters(const struct xt_table *table)
 932 {
 933         unsigned int countersize;
 934         struct xt_counters *counters;
 935         const struct xt_table_info *private = table->private;
 936
 937         /* We need atomic snapshot of counters: rest doesn't change
 938            (other than comefrom, which userspace doesn't care
 939            about). */
 940         countersize = sizeof(struct xt_counters) * private->number;
 941         counters = vzalloc(countersize);
 942
 943         if (counters == NULL)
 944                 return ERR_PTR(-ENOMEM);
 945
 946         get_counters(private, counters);
 947
 948         return counters;
 949 }
 950
 951 static int
 952 copy_entries_to_user(unsigned int total_size,
 953                      const struct xt_table *table,
 954                      void __user *userptr)
 955 {
 956         unsigned int off, num;
 957         const struct ip6t_entry *e;
 958         struct xt_counters *counters;
 959         const struct xt_table_info *private = table->private;
 960         int ret = 0;
 961         const void *loc_cpu_entry;
 962
 963         counters = alloc_counters(table);
 964         if (IS_ERR(counters))
 965                 return PTR_ERR(counters);
 966
 967         loc_cpu_entry = private->entries;
 968         if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
 969                 ret = -EFAULT;
 970                 goto free_counters;
 971         }
 972
 973         /* FIXME: use iterator macros --RR */
 974         /* ... then go back and fix counters and names */
 975         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
 976                 unsigned int i;
 977                 const struct xt_entry_match *m;
 978                 const struct xt_entry_target *t;
 979
 980                 e = (struct ip6t_entry *)(loc_cpu_entry + off);
 981                 if (copy_to_user(userptr + off
 982                                  + offsetof(struct ip6t_entry, counters),
 983                                  &counters[num],
 984                                  sizeof(counters[num])) != 0) {
 985                         ret = -EFAULT;
 986                         goto free_counters;
 987                 }
 988
 989                 for (i = sizeof(struct ip6t_entry);
 990                      i < e->target_offset;
 991                      i += m->u.match_size) {
 992                         m = (void *)e + i;
 993
 994                         if (copy_to_user(userptr + off + i
 995                                          + offsetof(struct xt_entry_match,
 996                                                     u.user.name),
 997                                          m->u.kernel.match->name,
 998                                          strlen(m->u.kernel.match->name)+1)
 999                             != 0) {
1000                                 ret = -EFAULT;
1001                                 goto free_counters;
1002                         }
1003                 }
1004
1005                 t = ip6t_get_target_c(e);
1006                 if (copy_to_user(userptr + off + e->target_offset
1007                                  + offsetof(struct xt_entry_target,
1008                                             u.user.name),
1009                                  t->u.kernel.target->name,
1010                                  strlen(t->u.kernel.target->name)+1) != 0) {
1011                         ret = -EFAULT;
1012                         goto free_counters;
1013                 }
1014         }
1015
1016  free_counters:
1017         vfree(counters);
1018         return ret;
1019 }
1020
1021 #ifdef CONFIG_COMPAT
1022 static void compat_standard_from_user(void *dst, const void *src)
1023 {
1024         int v = *(compat_int_t *)src;
1025
1026         if (v > 0)
1027                 v += xt_compat_calc_jump(AF_INET6, v);
1028         memcpy(dst, &v, sizeof(v));
1029 }
1030
1031 static int compat_standard_to_user(void __user *dst, const void *src)
1032 {
1033         compat_int_t cv = *(int *)src;
1034
1035         if (cv > 0)
1036                 cv -= xt_compat_calc_jump(AF_INET6, cv);
1037         return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
1038 }
1039
1040 static int compat_calc_entry(const struct ip6t_entry *e,
1041                              const struct xt_table_info *info,
1042                              const void *base, struct xt_table_info *newinfo)
1043 {
1044         const struct xt_entry_match *ematch;
1045         const struct xt_entry_target *t;
1046         unsigned int entry_offset;
1047         int off, i, ret;
1048
1049         off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1050         entry_offset = (void *)e - base;
1051         xt_ematch_foreach(ematch, e)
1052                 off += xt_compat_match_offset(ematch->u.kernel.match);
1053         t = ip6t_get_target_c(e);
1054         off += xt_compat_target_offset(t->u.kernel.target);
1055         newinfo->size -= off;
1056         ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
1057         if (ret)
1058                 return ret;
1059
1060         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1061                 if (info->hook_entry[i] &&
1062                     (e < (struct ip6t_entry *)(base + info->hook_entry[i])))
1063                         newinfo->hook_entry[i] -= off;
1064                 if (info->underflow[i] &&
1065                     (e < (struct ip6t_entry *)(base + info->underflow[i])))
1066                         newinfo->underflow[i] -= off;
1067         }
1068         return 0;
1069 }
1070
1071 static int compat_table_info(const struct xt_table_info *info,
1072                              struct xt_table_info *newinfo)
1073 {
1074         struct ip6t_entry *iter;
1075         const void *loc_cpu_entry;
1076         int ret;
1077
1078         if (!newinfo || !info)
1079                 return -EINVAL;
1080
1081         /* we dont care about newinfo->entries */
1082         memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
1083         newinfo->initial_entries = 0;
1084         loc_cpu_entry = info->entries;
1085         xt_compat_init_offsets(AF_INET6, info->number);
1086         xt_entry_foreach(iter, loc_cpu_entry, info->size) {
1087                 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
1088                 if (ret != 0)
1089                         return ret;
1090         }
1091         return 0;
1092 }
1093 #endif
1094
1095 static int get_info(struct net *net, void __user *user,
1096                     const int *len, int compat)
1097 {
1098         char name[XT_TABLE_MAXNAMELEN];
1099         struct xt_table *t;
1100         int ret;
1101
1102         if (*len != sizeof(struct ip6t_getinfo)) {
1103                 duprintf("length %u != %zu\n", *len,
1104                          sizeof(struct ip6t_getinfo));
1105                 return -EINVAL;
1106         }
1107
1108         if (copy_from_user(name, user, sizeof(name)) != 0)
1109                 return -EFAULT;
1110
1111         name[XT_TABLE_MAXNAMELEN-1] = '\0';
1112 #ifdef CONFIG_COMPAT
1113         if (compat)
1114                 xt_compat_lock(AF_INET6);
1115 #endif
1116         t = try_then_request_module(xt_find_table_lock(net, AF_INET6, name),
1117                                     "ip6table_%s", name);
1118         if (!IS_ERR_OR_NULL(t)) {
1119                 struct ip6t_getinfo info;
1120                 const struct xt_table_info *private = t->private;
1121 #ifdef CONFIG_COMPAT
1122                 struct xt_table_info tmp;
1123
1124                 if (compat) {
1125                         ret = compat_table_info(private, &tmp);
1126                         xt_compat_flush_offsets(AF_INET6);
1127                         private = &tmp;
1128                 }
1129 #endif
1130                 memset(&info, 0, sizeof(info));
1131                 info.valid_hooks = t->valid_hooks;
1132                 memcpy(info.hook_entry, private->hook_entry,
1133                        sizeof(info.hook_entry));
1134                 memcpy(info.underflow, private->underflow,
1135                        sizeof(info.underflow));
1136                 info.num_entries = private->number;
1137                 info.size = private->size;
1138                 strcpy(info.name, name);
1139
1140                 if (copy_to_user(user, &info, *len) != 0)
1141                         ret = -EFAULT;
1142                 else
1143                         ret = 0;
1144
1145                 xt_table_unlock(t);
1146                 module_put(t->me);
1147         } else
1148                 ret = t ? PTR_ERR(t) : -ENOENT;
1149 #ifdef CONFIG_COMPAT
1150         if (compat)
1151                 xt_compat_unlock(AF_INET6);
1152 #endif
1153         return ret;
1154 }
1155
1156 static int
1157 get_entries(struct net *net, struct ip6t_get_entries __user *uptr,
1158             const int *len)
1159 {
1160         int ret;
1161         struct ip6t_get_entries get;
1162         struct xt_table *t;
1163
1164         if (*len < sizeof(get)) {
1165                 duprintf("get_entries: %u < %zu\n", *len, sizeof(get));
1166                 return -EINVAL;
1167         }
1168         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1169                 return -EFAULT;
1170         if (*len != sizeof(struct ip6t_get_entries) + get.size) {
1171                 duprintf("get_entries: %u != %zu\n",
1172                          *len, sizeof(get) + get.size);
1173                 return -EINVAL;
1174         }
1175
1176         t = xt_find_table_lock(net, AF_INET6, get.name);
1177         if (!IS_ERR_OR_NULL(t)) {
1178                 struct xt_table_info *private = t->private;
1179                 duprintf("t->private->number = %u\n", private->number);
1180                 if (get.size == private->size)
1181                         ret = copy_entries_to_user(private->size,
1182                                                    t, uptr->entrytable);
1183                 else {
1184                         duprintf("get_entries: I've got %u not %u!\n",
1185                                  private->size, get.size);
1186                         ret = -EAGAIN;
1187                 }
1188                 module_put(t->me);
1189                 xt_table_unlock(t);
1190         } else
1191                 ret = t ? PTR_ERR(t) : -ENOENT;
1192
1193         return ret;
1194 }
1195
1196 static int
1197 __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1198              struct xt_table_info *newinfo, unsigned int num_counters,
1199              void __user *counters_ptr)
1200 {
1201         int ret;
1202         struct xt_table *t;
1203         struct xt_table_info *oldinfo;
1204         struct xt_counters *counters;
1205         struct ip6t_entry *iter;
1206
1207         ret = 0;
1208         counters = vzalloc(num_counters * sizeof(struct xt_counters));
1209         if (!counters) {
1210                 ret = -ENOMEM;
1211                 goto out;
1212         }
1213
1214         t = try_then_request_module(xt_find_table_lock(net, AF_INET6, name),
1215                                     "ip6table_%s", name);
1216         if (IS_ERR_OR_NULL(t)) {
1217                 ret = t ? PTR_ERR(t) : -ENOENT;
1218                 goto free_newinfo_counters_untrans;
1219         }
1220
1221         /* You lied! */
1222         if (valid_hooks != t->valid_hooks) {
1223                 duprintf("Valid hook crap: %08X vs %08X\n",
1224                          valid_hooks, t->valid_hooks);
1225                 ret = -EINVAL;
1226                 goto put_module;
1227         }
1228
1229         oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1230         if (!oldinfo)
1231                 goto put_module;
1232
1233         /* Update module usage count based on number of rules */
1234         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1235                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1236         if ((oldinfo->number > oldinfo->initial_entries) ||
1237             (newinfo->number <= oldinfo->initial_entries))
1238                 module_put(t->me);
1239         if ((oldinfo->number > oldinfo->initial_entries) &&
1240             (newinfo->number <= oldinfo->initial_entries))
1241                 module_put(t->me);
1242
1243         /* Get the old counters, and synchronize with replace */
1244         get_counters(oldinfo, counters);
1245
1246         /* Decrease module usage counts and free resource */
1247         xt_entry_foreach(iter, oldinfo->entries, oldinfo->size)
1248                 cleanup_entry(iter, net);
1249
1250         xt_free_table_info(oldinfo);
1251         if (copy_to_user(counters_ptr, counters,
1252                          sizeof(struct xt_counters) * num_counters) != 0) {
1253                 /* Silent error, can't fail, new table is already in place */
1254                 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n");
1255         }
1256         vfree(counters);
1257         xt_table_unlock(t);
1258         return ret;
1259
1260  put_module:
1261         module_put(t->me);
1262         xt_table_unlock(t);
1263  free_newinfo_counters_untrans:
1264         vfree(counters);
1265  out:
1266         return ret;
1267 }
1268
1269 static int
1270 do_replace(struct net *net, const void __user *user, unsigned int len)
1271 {
1272         int ret;
1273         struct ip6t_replace tmp;
1274         struct xt_table_info *newinfo;
1275         void *loc_cpu_entry;
1276         struct ip6t_entry *iter;
1277
1278         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1279                 return -EFAULT;
1280
1281         /* overflow check */
1282         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1283                 return -ENOMEM;
1284         if (tmp.num_counters == 0)
1285                 return -EINVAL;
1286
1287         tmp.name[sizeof(tmp.name)-1] = 0;
1288
1289         newinfo = xt_alloc_table_info(tmp.size);
1290         if (!newinfo)
1291                 return -ENOMEM;
1292
1293         loc_cpu_entry = newinfo->entries;
1294         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1295                            tmp.size) != 0) {
1296                 ret = -EFAULT;
1297                 goto free_newinfo;
1298         }
1299
1300         ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
1301         if (ret != 0)
1302                 goto free_newinfo;
1303
1304         duprintf("ip_tables: Translated table\n");
1305
1306         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1307                            tmp.num_counters, tmp.counters);
1308         if (ret)
1309                 goto free_newinfo_untrans;
1310         return 0;
1311
1312  free_newinfo_untrans:
1313         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1314                 cleanup_entry(iter, net);
1315  free_newinfo:
1316         xt_free_table_info(newinfo);
1317         return ret;
1318 }
1319
1320 static int
1321 do_add_counters(struct net *net, const void __user *user, unsigned int len,
1322                 int compat)
1323 {
1324         unsigned int i;
1325         struct xt_counters_info tmp;
1326         struct xt_counters *paddc;
1327         unsigned int num_counters;
1328         char *name;
1329         int size;
1330         void *ptmp;
1331         struct xt_table *t;
1332         const struct xt_table_info *private;
1333         int ret = 0;
1334         struct ip6t_entry *iter;
1335         unsigned int addend;
1336 #ifdef CONFIG_COMPAT
1337         struct compat_xt_counters_info compat_tmp;
1338
1339         if (compat) {
1340                 ptmp = &compat_tmp;
1341                 size = sizeof(struct compat_xt_counters_info);
1342         } else
1343 #endif
1344         {
1345                 ptmp = &tmp;
1346                 size = sizeof(struct xt_counters_info);
1347         }
1348
1349         if (copy_from_user(ptmp, user, size) != 0)
1350                 return -EFAULT;
1351
1352 #ifdef CONFIG_COMPAT
1353         if (compat) {
1354                 num_counters = compat_tmp.num_counters;
1355                 name = compat_tmp.name;
1356         } else
1357 #endif
1358         {
1359                 num_counters = tmp.num_counters;
1360                 name = tmp.name;
1361         }
1362
1363         if (len != size + num_counters * sizeof(struct xt_counters))
1364                 return -EINVAL;
1365
1366         paddc = vmalloc(len - size);
1367         if (!paddc)
1368                 return -ENOMEM;
1369
1370         if (copy_from_user(paddc, user + size, len - size) != 0) {
1371                 ret = -EFAULT;
1372                 goto free;
1373         }
1374
1375         t = xt_find_table_lock(net, AF_INET6, name);
1376         if (IS_ERR_OR_NULL(t)) {
1377                 ret = t ? PTR_ERR(t) : -ENOENT;
1378                 goto free;
1379         }
1380
1381         local_bh_disable();
1382         private = t->private;
1383         if (private->number != num_counters) {
1384                 ret = -EINVAL;
1385                 goto unlock_up_free;
1386         }
1387
1388         i = 0;
1389         addend = xt_write_recseq_begin();
1390         xt_entry_foreach(iter, private->entries, private->size) {
1391                 struct xt_counters *tmp;
1392
1393                 tmp = xt_get_this_cpu_counter(&iter->counters);
1394                 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt);
1395                 ++i;
1396         }
1397         xt_write_recseq_end(addend);
1398  unlock_up_free:
1399         local_bh_enable();
1400         xt_table_unlock(t);
1401         module_put(t->me);
1402  free:
1403         vfree(paddc);
1404
1405         return ret;
1406 }
1407
1408 #ifdef CONFIG_COMPAT
1409 struct compat_ip6t_replace {
1410         char                    name[XT_TABLE_MAXNAMELEN];
1411         u32                     valid_hooks;
1412         u32                     num_entries;
1413         u32                     size;
1414         u32                     hook_entry[NF_INET_NUMHOOKS];
1415         u32                     underflow[NF_INET_NUMHOOKS];
1416         u32                     num_counters;
1417         compat_uptr_t           counters;       /* struct xt_counters * */
1418         struct compat_ip6t_entry entries[0];
1419 };
1420
1421 static int
1422 compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr,
1423                           unsigned int *size, struct xt_counters *counters,
1424                           unsigned int i)
1425 {
1426         struct xt_entry_target *t;
1427         struct compat_ip6t_entry __user *ce;
1428         u_int16_t target_offset, next_offset;
1429         compat_uint_t origsize;
1430         const struct xt_entry_match *ematch;
1431         int ret = 0;
1432
1433         origsize = *size;
1434         ce = (struct compat_ip6t_entry __user *)*dstptr;
1435         if (copy_to_user(ce, e, sizeof(struct ip6t_entry)) != 0 ||
1436             copy_to_user(&ce->counters, &counters[i],
1437             sizeof(counters[i])) != 0)
1438                 return -EFAULT;
1439
1440         *dstptr += sizeof(struct compat_ip6t_entry);
1441         *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1442
1443         xt_ematch_foreach(ematch, e) {
1444                 ret = xt_compat_match_to_user(ematch, dstptr, size);
1445                 if (ret != 0)
1446                         return ret;
1447         }
1448         target_offset = e->target_offset - (origsize - *size);
1449         t = ip6t_get_target(e);
1450         ret = xt_compat_target_to_user(t, dstptr, size);
1451         if (ret)
1452                 return ret;
1453         next_offset = e->next_offset - (origsize - *size);
1454         if (put_user(target_offset, &ce->target_offset) != 0 ||
1455             put_user(next_offset, &ce->next_offset) != 0)
1456                 return -EFAULT;
1457         return 0;
1458 }
1459
1460 static int
1461 compat_find_calc_match(struct xt_entry_match *m,
1462                        const char *name,
1463                        const struct ip6t_ip6 *ipv6,
1464                        int *size)
1465 {
1466         struct xt_match *match;
1467
1468         match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
1469                                       m->u.user.revision);
1470         if (IS_ERR(match)) {
1471                 duprintf("compat_check_calc_match: `%s' not found\n",
1472                          m->u.user.name);
1473                 return PTR_ERR(match);
1474         }
1475         m->u.kernel.match = match;
1476         *size += xt_compat_match_offset(match);
1477         return 0;
1478 }
1479
1480 static void compat_release_entry(struct compat_ip6t_entry *e)
1481 {
1482         struct xt_entry_target *t;
1483         struct xt_entry_match *ematch;
1484
1485         /* Cleanup all matches */
1486         xt_ematch_foreach(ematch, e)
1487                 module_put(ematch->u.kernel.match->me);
1488         t = compat_ip6t_get_target(e);
1489         module_put(t->u.kernel.target->me);
1490 }
1491
1492 static int
1493 check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
1494                                   struct xt_table_info *newinfo,
1495                                   unsigned int *size,
1496                                   const unsigned char *base,
1497                                   const unsigned char *limit,
1498                                   const unsigned int *hook_entries,
1499                                   const unsigned int *underflows,
1500                                   const char *name)
1501 {
1502         struct xt_entry_match *ematch;
1503         struct xt_entry_target *t;
1504         struct xt_target *target;
1505         unsigned int entry_offset;
1506         unsigned int j;
1507         int ret, off, h;
1508
1509         duprintf("check_compat_entry_size_and_hooks %p\n", e);
1510         if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 ||
1511             (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit ||
1512             (unsigned char *)e + e->next_offset > limit) {
1513                 duprintf("Bad offset %p, limit = %p\n", e, limit);
1514                 return -EINVAL;
1515         }
1516
1517         if (e->next_offset < sizeof(struct compat_ip6t_entry) +
1518                              sizeof(struct compat_xt_entry_target)) {
1519                 duprintf("checking: element %p size %u\n",
1520                          e, e->next_offset);
1521                 return -EINVAL;
1522         }
1523
1524         if (!ip6_checkentry(&e->ipv6))
1525                 return -EINVAL;
1526
1527         ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
1528         if (ret)
1529                 return ret;
1530
1531         off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1532         entry_offset = (void *)e - (void *)base;
1533         j = 0;
1534         xt_ematch_foreach(ematch, e) {
1535                 ret = compat_find_calc_match(ematch, name, &e->ipv6, &off);
1536                 if (ret != 0)
1537                         goto release_matches;
1538                 ++j;
1539         }
1540
1541         t = compat_ip6t_get_target(e);
1542         target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
1543                                         t->u.user.revision);
1544         if (IS_ERR(target)) {
1545                 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1546                          t->u.user.name);
1547                 ret = PTR_ERR(target);
1548                 goto release_matches;
1549         }
1550         t->u.kernel.target = target;
1551
1552         off += xt_compat_target_offset(target);
1553         *size += off;
1554         ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
1555         if (ret)
1556                 goto out;
1557
1558         /* Check hooks & underflows */
1559         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1560                 if ((unsigned char *)e - base == hook_entries[h])
1561                         newinfo->hook_entry[h] = hook_entries[h];
1562                 if ((unsigned char *)e - base == underflows[h])
1563                         newinfo->underflow[h] = underflows[h];
1564         }
1565
1566         /* Clear counters and comefrom */
1567         memset(&e->counters, 0, sizeof(e->counters));
1568         e->comefrom = 0;
1569         return 0;
1570
1571 out:
1572         module_put(t->u.kernel.target->me);
1573 release_matches:
1574         xt_ematch_foreach(ematch, e) {
1575                 if (j-- == 0)
1576                         break;
1577                 module_put(ematch->u.kernel.match->me);
1578         }
1579         return ret;
1580 }
1581
1582 static int
1583 compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr,
1584                             unsigned int *size, const char *name,
1585                             struct xt_table_info *newinfo, unsigned char *base)
1586 {
1587         struct xt_entry_target *t;
1588         struct ip6t_entry *de;
1589         unsigned int origsize;
1590         int ret, h;
1591         struct xt_entry_match *ematch;
1592
1593         ret = 0;
1594         origsize = *size;
1595         de = (struct ip6t_entry *)*dstptr;
1596         memcpy(de, e, sizeof(struct ip6t_entry));
1597         memcpy(&de->counters, &e->counters, sizeof(e->counters));
1598
1599         *dstptr += sizeof(struct ip6t_entry);
1600         *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1601
1602         xt_ematch_foreach(ematch, e) {
1603                 ret = xt_compat_match_from_user(ematch, dstptr, size);
1604                 if (ret != 0)
1605                         return ret;
1606         }
1607         de->target_offset = e->target_offset - (origsize - *size);
1608         t = compat_ip6t_get_target(e);
1609         xt_compat_target_from_user(t, dstptr, size);
1610
1611         de->next_offset = e->next_offset - (origsize - *size);
1612         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1613                 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1614                         newinfo->hook_entry[h] -= origsize - *size;
1615                 if ((unsigned char *)de - base < newinfo->underflow[h])
1616                         newinfo->underflow[h] -= origsize - *size;
1617         }
1618         return ret;
1619 }
1620
1621 static int compat_check_entry(struct ip6t_entry *e, struct net *net,
1622                               const char *name)
1623 {
1624         unsigned int j;
1625         int ret = 0;
1626         struct xt_mtchk_param mtpar;
1627         struct xt_entry_match *ematch;
1628
1629         e->counters.pcnt = xt_percpu_counter_alloc();
1630         if (IS_ERR_VALUE(e->counters.pcnt))
1631                 return -ENOMEM;
1632         j = 0;
1633         mtpar.net       = net;
1634         mtpar.table     = name;
1635         mtpar.entryinfo = &e->ipv6;
1636         mtpar.hook_mask = e->comefrom;
1637         mtpar.family    = NFPROTO_IPV6;
1638         xt_ematch_foreach(ematch, e) {
1639                 ret = check_match(ematch, &mtpar);
1640                 if (ret != 0)
1641                         goto cleanup_matches;
1642                 ++j;
1643         }
1644
1645         ret = check_target(e, net, name);
1646         if (ret)
1647                 goto cleanup_matches;
1648         return 0;
1649
1650  cleanup_matches:
1651         xt_ematch_foreach(ematch, e) {
1652                 if (j-- == 0)
1653                         break;
1654                 cleanup_match(ematch, net);
1655         }
1656
1657         xt_percpu_counter_free(e->counters.pcnt);
1658
1659         return ret;
1660 }
1661
1662 static int
1663 translate_compat_table(struct net *net,
1664                        const char *name,
1665                        unsigned int valid_hooks,
1666                        struct xt_table_info **pinfo,
1667                        void **pentry0,
1668                        unsigned int total_size,
1669                        unsigned int number,
1670                        unsigned int *hook_entries,
1671                        unsigned int *underflows)
1672 {
1673         unsigned int i, j;
1674         struct xt_table_info *newinfo, *info;
1675         void *pos, *entry0, *entry1;
1676         struct compat_ip6t_entry *iter0;
1677         struct ip6t_entry *iter1;
1678         unsigned int size;
1679         int ret = 0;
1680
1681         info = *pinfo;
1682         entry0 = *pentry0;
1683         size = total_size;
1684         info->number = number;
1685
1686         /* Init all hooks to impossible value. */
1687         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1688                 info->hook_entry[i] = 0xFFFFFFFF;
1689                 info->underflow[i] = 0xFFFFFFFF;
1690         }
1691
1692         duprintf("translate_compat_table: size %u\n", info->size);
1693         j = 0;
1694         xt_compat_lock(AF_INET6);
1695         xt_compat_init_offsets(AF_INET6, number);
1696         /* Walk through entries, checking offsets. */
1697         xt_entry_foreach(iter0, entry0, total_size) {
1698                 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1699                                                         entry0,
1700                                                         entry0 + total_size,
1701                                                         hook_entries,
1702                                                         underflows,
1703                                                         name);
1704                 if (ret != 0)
1705                         goto out_unlock;
1706                 ++j;
1707         }
1708
1709         ret = -EINVAL;
1710         if (j != number) {
1711                 duprintf("translate_compat_table: %u not %u entries\n",
1712                          j, number);
1713                 goto out_unlock;
1714         }
1715
1716         /* Check hooks all assigned */
1717         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1718                 /* Only hooks which are valid */
1719                 if (!(valid_hooks & (1 << i)))
1720                         continue;
1721                 if (info->hook_entry[i] == 0xFFFFFFFF) {
1722                         duprintf("Invalid hook entry %u %u\n",
1723                                  i, hook_entries[i]);
1724                         goto out_unlock;
1725                 }
1726                 if (info->underflow[i] == 0xFFFFFFFF) {
1727                         duprintf("Invalid underflow %u %u\n",
1728                                  i, underflows[i]);
1729                         goto out_unlock;
1730                 }
1731         }
1732
1733         ret = -ENOMEM;
1734         newinfo = xt_alloc_table_info(size);
1735         if (!newinfo)
1736                 goto out_unlock;
1737
1738         newinfo->number = number;
1739         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1740                 newinfo->hook_entry[i] = info->hook_entry[i];
1741                 newinfo->underflow[i] = info->underflow[i];
1742         }
1743         entry1 = newinfo->entries;
1744         pos = entry1;
1745         size = total_size;
1746         xt_entry_foreach(iter0, entry0, total_size) {
1747                 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1748                                                   name, newinfo, entry1);
1749                 if (ret != 0)
1750                         break;
1751         }
1752         xt_compat_flush_offsets(AF_INET6);
1753         xt_compat_unlock(AF_INET6);
1754         if (ret)
1755                 goto free_newinfo;
1756
1757         ret = -ELOOP;
1758         if (!mark_source_chains(newinfo, valid_hooks, entry1))
1759                 goto free_newinfo;
1760
1761         i = 0;
1762         xt_entry_foreach(iter1, entry1, newinfo->size) {
1763                 ret = compat_check_entry(iter1, net, name);
1764                 if (ret != 0)
1765                         break;
1766                 ++i;
1767                 if (strcmp(ip6t_get_target(iter1)->u.user.name,
1768                     XT_ERROR_TARGET) == 0)
1769                         ++newinfo->stacksize;
1770         }
1771         if (ret) {
1772                 /*
1773                  * The first i matches need cleanup_entry (calls ->destroy)
1774                  * because they had called ->check already. The other j-i
1775                  * entries need only release.
1776                  */
1777                 int skip = i;
1778                 j -= i;
1779                 xt_entry_foreach(iter0, entry0, newinfo->size) {
1780                         if (skip-- > 0)
1781                                 continue;
1782                         if (j-- == 0)
1783                                 break;
1784                         compat_release_entry(iter0);
1785                 }
1786                 xt_entry_foreach(iter1, entry1, newinfo->size) {
1787                         if (i-- == 0)
1788                                 break;
1789                         cleanup_entry(iter1, net);
1790                 }
1791                 xt_free_table_info(newinfo);
1792                 return ret;
1793         }
1794
1795         *pinfo = newinfo;
1796         *pentry0 = entry1;
1797         xt_free_table_info(info);
1798         return 0;
1799
1800 free_newinfo:
1801         xt_free_table_info(newinfo);
1802 out:
1803         xt_entry_foreach(iter0, entry0, total_size) {
1804                 if (j-- == 0)
1805                         break;
1806                 compat_release_entry(iter0);
1807         }
1808         return ret;
1809 out_unlock:
1810         xt_compat_flush_offsets(AF_INET6);
1811         xt_compat_unlock(AF_INET6);
1812         goto out;
1813 }
1814
1815 static int
1816 compat_do_replace(struct net *net, void __user *user, unsigned int len)
1817 {
1818         int ret;
1819         struct compat_ip6t_replace tmp;
1820         struct xt_table_info *newinfo;
1821         void *loc_cpu_entry;
1822         struct ip6t_entry *iter;
1823
1824         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1825                 return -EFAULT;
1826
1827         /* overflow check */
1828         if (tmp.size >= INT_MAX / num_possible_cpus())
1829                 return -ENOMEM;
1830         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1831                 return -ENOMEM;
1832         if (tmp.num_counters == 0)
1833                 return -EINVAL;
1834
1835         tmp.name[sizeof(tmp.name)-1] = 0;
1836
1837         newinfo = xt_alloc_table_info(tmp.size);
1838         if (!newinfo)
1839                 return -ENOMEM;
1840
1841         loc_cpu_entry = newinfo->entries;
1842         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1843                            tmp.size) != 0) {
1844                 ret = -EFAULT;
1845                 goto free_newinfo;
1846         }
1847
1848         ret = translate_compat_table(net, tmp.name, tmp.valid_hooks,
1849                                      &newinfo, &loc_cpu_entry, tmp.size,
1850                                      tmp.num_entries, tmp.hook_entry,
1851                                      tmp.underflow);
1852         if (ret != 0)
1853                 goto free_newinfo;
1854
1855         duprintf("compat_do_replace: Translated table\n");
1856
1857         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1858                            tmp.num_counters, compat_ptr(tmp.counters));
1859         if (ret)
1860                 goto free_newinfo_untrans;
1861         return 0;
1862
1863  free_newinfo_untrans:
1864         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1865                 cleanup_entry(iter, net);
1866  free_newinfo:
1867         xt_free_table_info(newinfo);
1868         return ret;
1869 }
1870
1871 static int
1872 compat_do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user,
1873                        unsigned int len)
1874 {
1875         int ret;
1876
1877         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1878                 return -EPERM;
1879
1880         switch (cmd) {
1881         case IP6T_SO_SET_REPLACE:
1882                 ret = compat_do_replace(sock_net(sk), user, len);
1883                 break;
1884
1885         case IP6T_SO_SET_ADD_COUNTERS:
1886                 ret = do_add_counters(sock_net(sk), user, len, 1);
1887                 break;
1888
1889         default:
1890                 duprintf("do_ip6t_set_ctl:  unknown request %i\n", cmd);
1891                 ret = -EINVAL;
1892         }
1893
1894         return ret;
1895 }
1896
1897 struct compat_ip6t_get_entries {
1898         char name[XT_TABLE_MAXNAMELEN];
1899         compat_uint_t size;
1900         struct compat_ip6t_entry entrytable[0];
1901 };
1902
1903 static int
1904 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1905                             void __user *userptr)
1906 {
1907         struct xt_counters *counters;
1908         const struct xt_table_info *private = table->private;
1909         void __user *pos;
1910         unsigned int size;
1911         int ret = 0;
1912         unsigned int i = 0;
1913         struct ip6t_entry *iter;
1914
1915         counters = alloc_counters(table);
1916         if (IS_ERR(counters))
1917                 return PTR_ERR(counters);
1918
1919         pos = userptr;
1920         size = total_size;
1921         xt_entry_foreach(iter, private->entries, total_size) {
1922                 ret = compat_copy_entry_to_user(iter, &pos,
1923                                                 &size, counters, i++);
1924                 if (ret != 0)
1925                         break;
1926         }
1927
1928         vfree(counters);
1929         return ret;
1930 }
1931
1932 static int
1933 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr,
1934                    int *len)
1935 {
1936         int ret;
1937         struct compat_ip6t_get_entries get;
1938         struct xt_table *t;
1939
1940         if (*len < sizeof(get)) {
1941                 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1942                 return -EINVAL;
1943         }
1944
1945         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1946                 return -EFAULT;
1947
1948         if (*len != sizeof(struct compat_ip6t_get_entries) + get.size) {
1949                 duprintf("compat_get_entries: %u != %zu\n",
1950                          *len, sizeof(get) + get.size);
1951                 return -EINVAL;
1952         }
1953
1954         xt_compat_lock(AF_INET6);
1955         t = xt_find_table_lock(net, AF_INET6, get.name);
1956         if (!IS_ERR_OR_NULL(t)) {
1957                 const struct xt_table_info *private = t->private;
1958                 struct xt_table_info info;
1959                 duprintf("t->private->number = %u\n", private->number);
1960                 ret = compat_table_info(private, &info);
1961                 if (!ret && get.size == info.size) {
1962                         ret = compat_copy_entries_to_user(private->size,
1963                                                           t, uptr->entrytable);
1964                 } else if (!ret) {
1965                         duprintf("compat_get_entries: I've got %u not %u!\n",
1966                                  private->size, get.size);
1967                         ret = -EAGAIN;
1968                 }
1969                 xt_compat_flush_offsets(AF_INET6);
1970                 module_put(t->me);
1971                 xt_table_unlock(t);
1972         } else
1973                 ret = t ? PTR_ERR(t) : -ENOENT;
1974
1975         xt_compat_unlock(AF_INET6);
1976         return ret;
1977 }
1978
1979 static int do_ip6t_get_ctl(struct sock *, int, void __user *, int *);
1980
1981 static int
1982 compat_do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1983 {
1984         int ret;
1985
1986         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1987                 return -EPERM;
1988
1989         switch (cmd) {
1990         case IP6T_SO_GET_INFO:
1991                 ret = get_info(sock_net(sk), user, len, 1);
1992                 break;
1993         case IP6T_SO_GET_ENTRIES:
1994                 ret = compat_get_entries(sock_net(sk), user, len);
1995                 break;
1996         default:
1997                 ret = do_ip6t_get_ctl(sk, cmd, user, len);
1998         }
1999         return ret;
2000 }
2001 #endif
2002
2003 static int
2004 do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
2005 {
2006         int ret;
2007
2008         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2009                 return -EPERM;
2010
2011         switch (cmd) {
2012         case IP6T_SO_SET_REPLACE:
2013                 ret = do_replace(sock_net(sk), user, len);
2014                 break;
2015
2016         case IP6T_SO_SET_ADD_COUNTERS:
2017                 ret = do_add_counters(sock_net(sk), user, len, 0);
2018                 break;
2019
2020         default:
2021                 duprintf("do_ip6t_set_ctl:  unknown request %i\n", cmd);
2022                 ret = -EINVAL;
2023         }
2024
2025         return ret;
2026 }
2027
2028 static int
2029 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2030 {
2031         int ret;
2032
2033         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2034                 return -EPERM;
2035
2036         switch (cmd) {
2037         case IP6T_SO_GET_INFO:
2038                 ret = get_info(sock_net(sk), user, len, 0);
2039                 break;
2040
2041         case IP6T_SO_GET_ENTRIES:
2042                 ret = get_entries(sock_net(sk), user, len);
2043                 break;
2044
2045         case IP6T_SO_GET_REVISION_MATCH:
2046         case IP6T_SO_GET_REVISION_TARGET: {
2047                 struct xt_get_revision rev;
2048                 int target;
2049
2050                 if (*len != sizeof(rev)) {
2051                         ret = -EINVAL;
2052                         break;
2053                 }
2054                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
2055                         ret = -EFAULT;
2056                         break;
2057                 }
2058                 rev.name[sizeof(rev.name)-1] = 0;
2059
2060                 if (cmd == IP6T_SO_GET_REVISION_TARGET)
2061                         target = 1;
2062                 else
2063                         target = 0;
2064
2065                 try_then_request_module(xt_find_revision(AF_INET6, rev.name,
2066                                                          rev.revision,
2067                                                          target, &ret),
2068                                         "ip6t_%s", rev.name);
2069                 break;
2070         }
2071
2072         default:
2073                 duprintf("do_ip6t_get_ctl: unknown request %i\n", cmd);
2074                 ret = -EINVAL;
2075         }
2076
2077         return ret;
2078 }
2079
2080 struct xt_table *ip6t_register_table(struct net *net,
2081                                      const struct xt_table *table,
2082                                      const struct ip6t_replace *repl)
2083 {
2084         int ret;
2085         struct xt_table_info *newinfo;
2086         struct xt_table_info bootstrap = {0};
2087         void *loc_cpu_entry;
2088         struct xt_table *new_table;
2089
2090         newinfo = xt_alloc_table_info(repl->size);
2091         if (!newinfo) {
2092                 ret = -ENOMEM;
2093                 goto out;
2094         }
2095
2096         loc_cpu_entry = newinfo->entries;
2097         memcpy(loc_cpu_entry, repl->entries, repl->size);
2098
2099         ret = translate_table(net, newinfo, loc_cpu_entry, repl);
2100         if (ret != 0)
2101                 goto out_free;
2102
2103         new_table = xt_register_table(net, table, &bootstrap, newinfo);
2104         if (IS_ERR(new_table)) {
2105                 ret = PTR_ERR(new_table);
2106                 goto out_free;
2107         }
2108         return new_table;
2109
2110 out_free:
2111         xt_free_table_info(newinfo);
2112 out:
2113         return ERR_PTR(ret);
2114 }
2115
2116 void ip6t_unregister_table(struct net *net, struct xt_table *table)
2117 {
2118         struct xt_table_info *private;
2119         void *loc_cpu_entry;
2120         struct module *table_owner = table->me;
2121         struct ip6t_entry *iter;
2122
2123         private = xt_unregister_table(table);
2124
2125         /* Decrease module usage counts and free resources */
2126         loc_cpu_entry = private->entries;
2127         xt_entry_foreach(iter, loc_cpu_entry, private->size)
2128                 cleanup_entry(iter, net);
2129         if (private->number > private->initial_entries)
2130                 module_put(table_owner);
2131         xt_free_table_info(private);
2132 }
2133
2134 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
2135 static inline bool
2136 icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
2137                      u_int8_t type, u_int8_t code,
2138                      bool invert)
2139 {
2140         return (type == test_type && code >= min_code && code <= max_code)
2141                 ^ invert;
2142 }
2143
2144 static bool
2145 icmp6_match(const struct sk_buff *skb, struct xt_action_param *par)
2146 {
2147         const struct icmp6hdr *ic;
2148         struct icmp6hdr _icmph;
2149         const struct ip6t_icmp *icmpinfo = par->matchinfo;
2150
2151         /* Must not be a fragment. */
2152         if (par->fragoff != 0)
2153                 return false;
2154
2155         ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
2156         if (ic == NULL) {
2157                 /* We've been asked to examine this packet, and we
2158                  * can't.  Hence, no choice but to drop.
2159                  */
2160                 duprintf("Dropping evil ICMP tinygram.\n");
2161                 par->hotdrop = true;
2162                 return false;
2163         }
2164
2165         return icmp6_type_code_match(icmpinfo->type,
2166                                      icmpinfo->code[0],
2167                                      icmpinfo->code[1],
2168                                      ic->icmp6_type, ic->icmp6_code,
2169                                      !!(icmpinfo->invflags&IP6T_ICMP_INV));
2170 }
2171
2172 /* Called when user tries to insert an entry of this type. */
2173 static int icmp6_checkentry(const struct xt_mtchk_param *par)
2174 {
2175         const struct ip6t_icmp *icmpinfo = par->matchinfo;
2176
2177         /* Must specify no unknown invflags */
2178         return (icmpinfo->invflags & ~IP6T_ICMP_INV) ? -EINVAL : 0;
2179 }
2180
2181 /* The built-in targets: standard (NULL) and error. */
2182 static struct xt_target ip6t_builtin_tg[] __read_mostly = {
2183         {
2184                 .name             = XT_STANDARD_TARGET,
2185                 .targetsize       = sizeof(int),
2186                 .family           = NFPROTO_IPV6,
2187 #ifdef CONFIG_COMPAT
2188                 .compatsize       = sizeof(compat_int_t),
2189                 .compat_from_user = compat_standard_from_user,
2190                 .compat_to_user   = compat_standard_to_user,
2191 #endif
2192         },
2193         {
2194                 .name             = XT_ERROR_TARGET,
2195                 .target           = ip6t_error,
2196                 .targetsize       = XT_FUNCTION_MAXNAMELEN,
2197                 .family           = NFPROTO_IPV6,
2198         },
2199 };
2200
2201 static struct nf_sockopt_ops ip6t_sockopts = {
2202         .pf             = PF_INET6,
2203         .set_optmin     = IP6T_BASE_CTL,
2204         .set_optmax     = IP6T_SO_SET_MAX+1,
2205         .set            = do_ip6t_set_ctl,
2206 #ifdef CONFIG_COMPAT
2207         .compat_set     = compat_do_ip6t_set_ctl,
2208 #endif
2209         .get_optmin     = IP6T_BASE_CTL,
2210         .get_optmax     = IP6T_SO_GET_MAX+1,
2211         .get            = do_ip6t_get_ctl,
2212 #ifdef CONFIG_COMPAT
2213         .compat_get     = compat_do_ip6t_get_ctl,
2214 #endif
2215         .owner          = THIS_MODULE,
2216 };
2217
2218 static struct xt_match ip6t_builtin_mt[] __read_mostly = {
2219         {
2220                 .name       = "icmp6",
2221                 .match      = icmp6_match,
2222                 .matchsize  = sizeof(struct ip6t_icmp),
2223                 .checkentry = icmp6_checkentry,
2224                 .proto      = IPPROTO_ICMPV6,
2225                 .family     = NFPROTO_IPV6,
2226         },
2227 };
2228
2229 static int __net_init ip6_tables_net_init(struct net *net)
2230 {
2231         return xt_proto_init(net, NFPROTO_IPV6);
2232 }
2233
2234 static void __net_exit ip6_tables_net_exit(struct net *net)
2235 {
2236         xt_proto_fini(net, NFPROTO_IPV6);
2237 }
2238
2239 static struct pernet_operations ip6_tables_net_ops = {
2240         .init = ip6_tables_net_init,
2241         .exit = ip6_tables_net_exit,
2242 };
2243
2244 static int __init ip6_tables_init(void)
2245 {
2246         int ret;
2247
2248         ret = register_pernet_subsys(&ip6_tables_net_ops);
2249         if (ret < 0)
2250                 goto err1;
2251
2252         /* No one else will be downing sem now, so we won't sleep */
2253         ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
2254         if (ret < 0)
2255                 goto err2;
2256         ret = xt_register_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
2257         if (ret < 0)
2258                 goto err4;
2259
2260         /* Register setsockopt */
2261         ret = nf_register_sockopt(&ip6t_sockopts);
2262         if (ret < 0)
2263                 goto err5;
2264
2265         pr_info("(C) 2000-2006 Netfilter Core Team\n");
2266         return 0;
2267
2268 err5:
2269         xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
2270 err4:
2271         xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
2272 err2:
2273         unregister_pernet_subsys(&ip6_tables_net_ops);
2274 err1:
2275         return ret;
2276 }
2277
2278 static void __exit ip6_tables_fini(void)
2279 {
2280         nf_unregister_sockopt(&ip6t_sockopts);
2281
2282         xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
2283         xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
2284         unregister_pernet_subsys(&ip6_tables_net_ops);
2285 }
2286
2287 EXPORT_SYMBOL(ip6t_register_table);
2288 EXPORT_SYMBOL(ip6t_unregister_table);
2289 EXPORT_SYMBOL(ip6t_do_table);
2290
2291 module_init(ip6_tables_init);
2292 module_exit(ip6_tables_fini);