net/ipv4/netfilter/ip_tables.c

   1 /*
   2  * Packet matching code.
   3  *
   4  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
   5  * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12 #include <linux/cache.h>
  13 #include <linux/capability.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/kmod.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/module.h>
  19 #include <linux/icmp.h>
  20 #include <net/ip.h>
  21 #include <net/compat.h>
  22 #include <asm/uaccess.h>
  23 #include <linux/mutex.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/err.h>
  26 #include <linux/cpumask.h>
  27
  28 #include <linux/netfilter/x_tables.h>
  29 #include <linux/netfilter_ipv4/ip_tables.h>
  30 #include <net/netfilter/nf_log.h>
  31 #include "../../netfilter/xt_repldata.h"
  32
  33 MODULE_LICENSE("GPL");
  34 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  35 MODULE_DESCRIPTION("IPv4 packet filter");
  36
  37 /*#define DEBUG_IP_FIREWALL*/
  38 /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
  39 /*#define DEBUG_IP_FIREWALL_USER*/
  40
  41 #ifdef DEBUG_IP_FIREWALL
  42 #define dprintf(format, args...) pr_info(format , ## args)
  43 #else
  44 #define dprintf(format, args...)
  45 #endif
  46
  47 #ifdef DEBUG_IP_FIREWALL_USER
  48 #define duprintf(format, args...) pr_info(format , ## args)
  49 #else
  50 #define duprintf(format, args...)
  51 #endif
  52
  53 #ifdef CONFIG_NETFILTER_DEBUG
  54 #define IP_NF_ASSERT(x)         WARN_ON(!(x))
  55 #else
  56 #define IP_NF_ASSERT(x)
  57 #endif
  58
  59 #if 0
  60 /* All the better to debug you with... */
  61 #define static
  62 #define inline
  63 #endif
  64
  65 void *ipt_alloc_initial_table(const struct xt_table *info)
  66 {
  67         return xt_alloc_initial_table(ipt, IPT);
  68 }
  69 EXPORT_SYMBOL_GPL(ipt_alloc_initial_table);
  70
  71 /*
  72    We keep a set of rules for each CPU, so we can avoid write-locking
  73    them in the softirq when updating the counters and therefore
  74    only need to read-lock in the softirq; doing a write_lock_bh() in user
  75    context stops packets coming through and allows user context to read
  76    the counters or update the rules.
  77
  78    Hence the start of any table is given by get_table() below.  */
  79
  80 /* Returns whether matches rule or not. */
  81 /* Performance critical - called for every packet */
  82 static inline bool
  83 ip_packet_match(const struct iphdr *ip,
  84                 const char *indev,
  85                 const char *outdev,
  86                 const struct ipt_ip *ipinfo,
  87                 int isfrag)
  88 {
  89         unsigned long ret;
  90
  91 #define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
  92
  93         if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
  94                   IPT_INV_SRCIP) ||
  95             FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
  96                   IPT_INV_DSTIP)) {
  97                 dprintf("Source or dest mismatch.\n");
  98
  99                 dprintf("SRC: %pI4. Mask: %pI4. Target: %pI4.%s\n",
 100                         &ip->saddr, &ipinfo->smsk.s_addr, &ipinfo->src.s_addr,
 101                         ipinfo->invflags & IPT_INV_SRCIP ? " (INV)" : "");
 102                 dprintf("DST: %pI4 Mask: %pI4 Target: %pI4.%s\n",
 103                         &ip->daddr, &ipinfo->dmsk.s_addr, &ipinfo->dst.s_addr,
 104                         ipinfo->invflags & IPT_INV_DSTIP ? " (INV)" : "");
 105                 return false;
 106         }
 107
 108         ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask);
 109
 110         if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
 111                 dprintf("VIA in mismatch (%s vs %s).%s\n",
 112                         indev, ipinfo->iniface,
 113                         ipinfo->invflags&IPT_INV_VIA_IN ?" (INV)":"");
 114                 return false;
 115         }
 116
 117         ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask);
 118
 119         if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
 120                 dprintf("VIA out mismatch (%s vs %s).%s\n",
 121                         outdev, ipinfo->outiface,
 122                         ipinfo->invflags&IPT_INV_VIA_OUT ?" (INV)":"");
 123                 return false;
 124         }
 125
 126         /* Check specific protocol */
 127         if (ipinfo->proto &&
 128             FWINV(ip->protocol != ipinfo->proto, IPT_INV_PROTO)) {
 129                 dprintf("Packet protocol %hi does not match %hi.%s\n",
 130                         ip->protocol, ipinfo->proto,
 131                         ipinfo->invflags&IPT_INV_PROTO ? " (INV)":"");
 132                 return false;
 133         }
 134
 135         /* If we have a fragment rule but the packet is not a fragment
 136          * then we return zero */
 137         if (FWINV((ipinfo->flags&IPT_F_FRAG) && !isfrag, IPT_INV_FRAG)) {
 138                 dprintf("Fragment rule but not fragment.%s\n",
 139                         ipinfo->invflags & IPT_INV_FRAG ? " (INV)" : "");
 140                 return false;
 141         }
 142
 143         return true;
 144 }
 145
 146 static bool
 147 ip_checkentry(const struct ipt_ip *ip)
 148 {
 149         if (ip->flags & ~IPT_F_MASK) {
 150                 duprintf("Unknown flag bits set: %08X\n",
 151                          ip->flags & ~IPT_F_MASK);
 152                 return false;
 153         }
 154         if (ip->invflags & ~IPT_INV_MASK) {
 155                 duprintf("Unknown invflag bits set: %08X\n",
 156                          ip->invflags & ~IPT_INV_MASK);
 157                 return false;
 158         }
 159         return true;
 160 }
 161
 162 static unsigned int
 163 ipt_error(struct sk_buff *skb, const struct xt_action_param *par)
 164 {
 165         if (net_ratelimit())
 166                 pr_info("error: `%s'\n", (const char *)par->targinfo);
 167
 168         return NF_DROP;
 169 }
 170
 171 /* Performance critical */
 172 static inline struct ipt_entry *
 173 get_entry(const void *base, unsigned int offset)
 174 {
 175         return (struct ipt_entry *)(base + offset);
 176 }
 177
 178 /* All zeroes == unconditional rule. */
 179 /* Mildly perf critical (only if packet tracing is on) */
 180 static inline bool unconditional(const struct ipt_ip *ip)
 181 {
 182         static const struct ipt_ip uncond;
 183
 184         return memcmp(ip, &uncond, sizeof(uncond)) == 0;
 185 #undef FWINV
 186 }
 187
 188 /* for const-correctness */
 189 static inline const struct xt_entry_target *
 190 ipt_get_target_c(const struct ipt_entry *e)
 191 {
 192         return ipt_get_target((struct ipt_entry *)e);
 193 }
 194
 195 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
 196     defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
 197 static const char *const hooknames[] = {
 198         [NF_INET_PRE_ROUTING]           = "PREROUTING",
 199         [NF_INET_LOCAL_IN]              = "INPUT",
 200         [NF_INET_FORWARD]               = "FORWARD",
 201         [NF_INET_LOCAL_OUT]             = "OUTPUT",
 202         [NF_INET_POST_ROUTING]          = "POSTROUTING",
 203 };
 204
 205 enum nf_ip_trace_comments {
 206         NF_IP_TRACE_COMMENT_RULE,
 207         NF_IP_TRACE_COMMENT_RETURN,
 208         NF_IP_TRACE_COMMENT_POLICY,
 209 };
 210
 211 static const char *const comments[] = {
 212         [NF_IP_TRACE_COMMENT_RULE]      = "rule",
 213         [NF_IP_TRACE_COMMENT_RETURN]    = "return",
 214         [NF_IP_TRACE_COMMENT_POLICY]    = "policy",
 215 };
 216
 217 static struct nf_loginfo trace_loginfo = {
 218         .type = NF_LOG_TYPE_LOG,
 219         .u = {
 220                 .log = {
 221                         .level = 4,
 222                         .logflags = NF_LOG_MASK,
 223                 },
 224         },
 225 };
 226
 227 /* Mildly perf critical (only if packet tracing is on) */
 228 static inline int
 229 get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e,
 230                       const char *hookname, const char **chainname,
 231                       const char **comment, unsigned int *rulenum)
 232 {
 233         const struct xt_standard_target *t = (void *)ipt_get_target_c(s);
 234
 235         if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
 236                 /* Head of user chain: ERROR target with chainname */
 237                 *chainname = t->target.data;
 238                 (*rulenum) = 0;
 239         } else if (s == e) {
 240                 (*rulenum)++;
 241
 242                 if (s->target_offset == sizeof(struct ipt_entry) &&
 243                     strcmp(t->target.u.kernel.target->name,
 244                            XT_STANDARD_TARGET) == 0 &&
 245                    t->verdict < 0 &&
 246                    unconditional(&s->ip)) {
 247                         /* Tail of chains: STANDARD target (return/policy) */
 248                         *comment = *chainname == hookname
 249                                 ? comments[NF_IP_TRACE_COMMENT_POLICY]
 250                                 : comments[NF_IP_TRACE_COMMENT_RETURN];
 251                 }
 252                 return 1;
 253         } else
 254                 (*rulenum)++;
 255
 256         return 0;
 257 }
 258
 259 static void trace_packet(const struct sk_buff *skb,
 260                          unsigned int hook,
 261                          const struct net_device *in,
 262                          const struct net_device *out,
 263                          const char *tablename,
 264                          const struct xt_table_info *private,
 265                          const struct ipt_entry *e)
 266 {
 267         const void *table_base;
 268         const struct ipt_entry *root;
 269         const char *hookname, *chainname, *comment;
 270         const struct ipt_entry *iter;
 271         unsigned int rulenum = 0;
 272
 273         table_base = private->entries[smp_processor_id()];
 274         root = get_entry(table_base, private->hook_entry[hook]);
 275
 276         hookname = chainname = hooknames[hook];
 277         comment = comments[NF_IP_TRACE_COMMENT_RULE];
 278
 279         xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
 280                 if (get_chainname_rulenum(iter, e, hookname,
 281                     &chainname, &comment, &rulenum) != 0)
 282                         break;
 283
 284         nf_log_packet(AF_INET, hook, skb, in, out, &trace_loginfo,
 285                       "TRACE: %s:%s:%s:%u ",
 286                       tablename, chainname, comment, rulenum);
 287 }
 288 #endif
 289
 290 static inline __pure
 291 struct ipt_entry *ipt_next_entry(const struct ipt_entry *entry)
 292 {
 293         return (void *)entry + entry->next_offset;
 294 }
 295
 296 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
 297 unsigned int
 298 ipt_do_table(struct sk_buff *skb,
 299              unsigned int hook,
 300              const struct net_device *in,
 301              const struct net_device *out,
 302              struct xt_table *table)
 303 {
 304         static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
 305         const struct iphdr *ip;
 306         /* Initializing verdict to NF_DROP keeps gcc happy. */
 307         unsigned int verdict = NF_DROP;
 308         const char *indev, *outdev;
 309         const void *table_base;
 310         struct ipt_entry *e, **jumpstack;
 311         unsigned int *stackptr, origptr, cpu;
 312         const struct xt_table_info *private;
 313         struct xt_action_param acpar;
 314
 315         /* Initialization */
 316         ip = ip_hdr(skb);
 317         indev = in ? in->name : nulldevname;
 318         outdev = out ? out->name : nulldevname;
 319         /* We handle fragments by dealing with the first fragment as
 320          * if it was a normal packet.  All other fragments are treated
 321          * normally, except that they will NEVER match rules that ask
 322          * things we don't know, ie. tcp syn flag or ports).  If the
 323          * rule is also a fragment-specific rule, non-fragments won't
 324          * match it. */
 325         acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
 326         acpar.thoff   = ip_hdrlen(skb);
 327         acpar.hotdrop = false;
 328         acpar.in      = in;
 329         acpar.out     = out;
 330         acpar.family  = NFPROTO_IPV4;
 331         acpar.hooknum = hook;
 332
 333         IP_NF_ASSERT(table->valid_hooks & (1 << hook));
 334         xt_info_rdlock_bh();
 335         private = table->private;
 336         cpu        = smp_processor_id();
 337         table_base = private->entries[cpu];
 338         jumpstack  = (struct ipt_entry **)private->jumpstack[cpu];
 339         stackptr   = per_cpu_ptr(private->stackptr, cpu);
 340         origptr    = *stackptr;
 341
 342         e = get_entry(table_base, private->hook_entry[hook]);
 343
 344         pr_debug("Entering %s(hook %u); sp at %u (UF %p)\n",
 345                  table->name, hook, origptr,
 346                  get_entry(table_base, private->underflow[hook]));
 347
 348         do {
 349                 const struct xt_entry_target *t;
 350                 const struct xt_entry_match *ematch;
 351
 352                 IP_NF_ASSERT(e);
 353                 if (!ip_packet_match(ip, indev, outdev,
 354                     &e->ip, acpar.fragoff)) {
 355  no_match:
 356                         e = ipt_next_entry(e);
 357                         continue;
 358                 }
 359
 360                 xt_ematch_foreach(ematch, e) {
 361                         acpar.match     = ematch->u.kernel.match;
 362                         acpar.matchinfo = ematch->data;
 363                         if (!acpar.match->match(skb, &acpar))
 364                                 goto no_match;
 365                 }
 366
 367                 ADD_COUNTER(e->counters, skb->len, 1);
 368
 369                 t = ipt_get_target(e);
 370                 IP_NF_ASSERT(t->u.kernel.target);
 371
 372 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
 373     defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
 374                 /* The packet is traced: log it */
 375                 if (unlikely(skb->nf_trace))
 376                         trace_packet(skb, hook, in, out,
 377                                      table->name, private, e);
 378 #endif
 379                 /* Standard target? */
 380                 if (!t->u.kernel.target->target) {
 381                         int v;
 382
 383                         v = ((struct xt_standard_target *)t)->verdict;
 384                         if (v < 0) {
 385                                 /* Pop from stack? */
 386                                 if (v != XT_RETURN) {
 387                                         verdict = (unsigned)(-v) - 1;
 388                                         break;
 389                                 }
 390                                 if (*stackptr == 0) {
 391                                         e = get_entry(table_base,
 392                                             private->underflow[hook]);
 393                                         pr_debug("Underflow (this is normal) "
 394                                                  "to %p\n", e);
 395                                 } else {
 396                                         e = jumpstack[--*stackptr];
 397                                         pr_debug("Pulled %p out from pos %u\n",
 398                                                  e, *stackptr);
 399                                         e = ipt_next_entry(e);
 400                                 }
 401                                 continue;
 402                         }
 403                         if (table_base + v != ipt_next_entry(e) &&
 404                             !(e->ip.flags & IPT_F_GOTO)) {
 405                                 if (*stackptr >= private->stacksize) {
 406                                         verdict = NF_DROP;
 407                                         break;
 408                                 }
 409                                 jumpstack[(*stackptr)++] = e;
 410                                 pr_debug("Pushed %p into pos %u\n",
 411                                          e, *stackptr - 1);
 412                         }
 413
 414                         e = get_entry(table_base, v);
 415                         continue;
 416                 }
 417
 418                 acpar.target   = t->u.kernel.target;
 419                 acpar.targinfo = t->data;
 420
 421                 verdict = t->u.kernel.target->target(skb, &acpar);
 422                 /* Target might have changed stuff. */
 423                 ip = ip_hdr(skb);
 424                 if (verdict == XT_CONTINUE)
 425                         e = ipt_next_entry(e);
 426                 else
 427                         /* Verdict */
 428                         break;
 429         } while (!acpar.hotdrop);
 430         xt_info_rdunlock_bh();
 431         pr_debug("Exiting %s; resetting sp from %u to %u\n",
 432                  __func__, *stackptr, origptr);
 433         *stackptr = origptr;
 434 #ifdef DEBUG_ALLOW_ALL
 435         return NF_ACCEPT;
 436 #else
 437         if (acpar.hotdrop)
 438                 return NF_DROP;
 439         else return verdict;
 440 #endif
 441 }
 442
 443 /* Figures out from what hook each rule can be called: returns 0 if
 444    there are loops.  Puts hook bitmask in comefrom. */
 445 static int
 446 mark_source_chains(const struct xt_table_info *newinfo,
 447                    unsigned int valid_hooks, void *entry0)
 448 {
 449         unsigned int hook;
 450
 451         /* No recursion; use packet counter to save back ptrs (reset
 452            to 0 as we leave), and comefrom to save source hook bitmask */
 453         for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
 454                 unsigned int pos = newinfo->hook_entry[hook];
 455                 struct ipt_entry *e = (struct ipt_entry *)(entry0 + pos);
 456
 457                 if (!(valid_hooks & (1 << hook)))
 458                         continue;
 459
 460                 /* Set initial back pointer. */
 461                 e->counters.pcnt = pos;
 462
 463                 for (;;) {
 464                         const struct xt_standard_target *t
 465                                 = (void *)ipt_get_target_c(e);
 466                         int visited = e->comefrom & (1 << hook);
 467
 468                         if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
 469                                 pr_err("iptables: loop hook %u pos %u %08X.\n",
 470                                        hook, pos, e->comefrom);
 471                                 return 0;
 472                         }
 473                         e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
 474
 475                         /* Unconditional return/END. */
 476                         if ((e->target_offset == sizeof(struct ipt_entry) &&
 477                              (strcmp(t->target.u.user.name,
 478                                      XT_STANDARD_TARGET) == 0) &&
 479                              t->verdict < 0 && unconditional(&e->ip)) ||
 480                             visited) {
 481                                 unsigned int oldpos, size;
 482
 483                                 if ((strcmp(t->target.u.user.name,
 484                                             XT_STANDARD_TARGET) == 0) &&
 485                                     t->verdict < -NF_MAX_VERDICT - 1) {
 486                                         duprintf("mark_source_chains: bad "
 487                                                 "negative verdict (%i)\n",
 488                                                                 t->verdict);
 489                                         return 0;
 490                                 }
 491
 492                                 /* Return: backtrack through the last
 493                                    big jump. */
 494                                 do {
 495                                         e->comefrom ^= (1<<NF_INET_NUMHOOKS);
 496 #ifdef DEBUG_IP_FIREWALL_USER
 497                                         if (e->comefrom
 498                                             & (1 << NF_INET_NUMHOOKS)) {
 499                                                 duprintf("Back unset "
 500                                                          "on hook %u "
 501                                                          "rule %u\n",
 502                                                          hook, pos);
 503                                         }
 504 #endif
 505                                         oldpos = pos;
 506                                         pos = e->counters.pcnt;
 507                                         e->counters.pcnt = 0;
 508
 509                                         /* We're at the start. */
 510                                         if (pos == oldpos)
 511                                                 goto next;
 512
 513                                         e = (struct ipt_entry *)
 514                                                 (entry0 + pos);
 515                                 } while (oldpos == pos + e->next_offset);
 516
 517                                 /* Move along one */
 518                                 size = e->next_offset;
 519                                 e = (struct ipt_entry *)
 520                                         (entry0 + pos + size);
 521                                 e->counters.pcnt = pos;
 522                                 pos += size;
 523                         } else {
 524                                 int newpos = t->verdict;
 525
 526                                 if (strcmp(t->target.u.user.name,
 527                                            XT_STANDARD_TARGET) == 0 &&
 528                                     newpos >= 0) {
 529                                         if (newpos > newinfo->size -
 530                                                 sizeof(struct ipt_entry)) {
 531                                                 duprintf("mark_source_chains: "
 532                                                         "bad verdict (%i)\n",
 533                                                                 newpos);
 534                                                 return 0;
 535                                         }
 536                                         /* This a jump; chase it. */
 537                                         duprintf("Jump rule %u -> %u\n",
 538                                                  pos, newpos);
 539                                 } else {
 540                                         /* ... this is a fallthru */
 541                                         newpos = pos + e->next_offset;
 542                                 }
 543                                 e = (struct ipt_entry *)
 544                                         (entry0 + newpos);
 545                                 e->counters.pcnt = pos;
 546                                 pos = newpos;
 547                         }
 548                 }
 549                 next:
 550                 duprintf("Finished chain %u\n", hook);
 551         }
 552         return 1;
 553 }
 554
 555 static void cleanup_match(struct xt_entry_match *m, struct net *net)
 556 {
 557         struct xt_mtdtor_param par;
 558
 559         par.net       = net;
 560         par.match     = m->u.kernel.match;
 561         par.matchinfo = m->data;
 562         par.family    = NFPROTO_IPV4;
 563         if (par.match->destroy != NULL)
 564                 par.match->destroy(&par);
 565         module_put(par.match->me);
 566 }
 567
 568 static int
 569 check_entry(const struct ipt_entry *e, const char *name)
 570 {
 571         const struct xt_entry_target *t;
 572
 573         if (!ip_checkentry(&e->ip)) {
 574                 duprintf("ip check failed %p %s.\n", e, par->match->name);
 575                 return -EINVAL;
 576         }
 577
 578         if (e->target_offset + sizeof(struct xt_entry_target) >
 579             e->next_offset)
 580                 return -EINVAL;
 581
 582         t = ipt_get_target_c(e);
 583         if (e->target_offset + t->u.target_size > e->next_offset)
 584                 return -EINVAL;
 585
 586         return 0;
 587 }
 588
 589 static int
 590 check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
 591 {
 592         const struct ipt_ip *ip = par->entryinfo;
 593         int ret;
 594
 595         par->match     = m->u.kernel.match;
 596         par->matchinfo = m->data;
 597
 598         ret = xt_check_match(par, m->u.match_size - sizeof(*m),
 599               ip->proto, ip->invflags & IPT_INV_PROTO);
 600         if (ret < 0) {
 601                 duprintf("check failed for `%s'.\n", par->match->name);
 602                 return ret;
 603         }
 604         return 0;
 605 }
 606
 607 static int
 608 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
 609 {
 610         struct xt_match *match;
 611         int ret;
 612
 613         match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
 614                                       m->u.user.revision);
 615         if (IS_ERR(match)) {
 616                 duprintf("find_check_match: `%s' not found\n", m->u.user.name);
 617                 return PTR_ERR(match);
 618         }
 619         m->u.kernel.match = match;
 620
 621         ret = check_match(m, par);
 622         if (ret)
 623                 goto err;
 624
 625         return 0;
 626 err:
 627         module_put(m->u.kernel.match->me);
 628         return ret;
 629 }
 630
 631 static int check_target(struct ipt_entry *e, struct net *net, const char *name)
 632 {
 633         struct xt_entry_target *t = ipt_get_target(e);
 634         struct xt_tgchk_param par = {
 635                 .net       = net,
 636                 .table     = name,
 637                 .entryinfo = e,
 638                 .target    = t->u.kernel.target,
 639                 .targinfo  = t->data,
 640                 .hook_mask = e->comefrom,
 641                 .family    = NFPROTO_IPV4,
 642         };
 643         int ret;
 644
 645         ret = xt_check_target(&par, t->u.target_size - sizeof(*t),
 646               e->ip.proto, e->ip.invflags & IPT_INV_PROTO);
 647         if (ret < 0) {
 648                 duprintf("check failed for `%s'.\n",
 649                          t->u.kernel.target->name);
 650                 return ret;
 651         }
 652         return 0;
 653 }
 654
 655 static int
 656 find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
 657                  unsigned int size)
 658 {
 659         struct xt_entry_target *t;
 660         struct xt_target *target;
 661         int ret;
 662         unsigned int j;
 663         struct xt_mtchk_param mtpar;
 664         struct xt_entry_match *ematch;
 665
 666         ret = check_entry(e, name);
 667         if (ret)
 668                 return ret;
 669
 670         j = 0;
 671         mtpar.net       = net;
 672         mtpar.table     = name;
 673         mtpar.entryinfo = &e->ip;
 674         mtpar.hook_mask = e->comefrom;
 675         mtpar.family    = NFPROTO_IPV4;
 676         xt_ematch_foreach(ematch, e) {
 677                 ret = find_check_match(ematch, &mtpar);
 678                 if (ret != 0)
 679                         goto cleanup_matches;
 680                 ++j;
 681         }
 682
 683         t = ipt_get_target(e);
 684         target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
 685                                         t->u.user.revision);
 686         if (IS_ERR(target)) {
 687                 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
 688                 ret = PTR_ERR(target);
 689                 goto cleanup_matches;
 690         }
 691         t->u.kernel.target = target;
 692
 693         ret = check_target(e, net, name);
 694         if (ret)
 695                 goto err;
 696         return 0;
 697  err:
 698         module_put(t->u.kernel.target->me);
 699  cleanup_matches:
 700         xt_ematch_foreach(ematch, e) {
 701                 if (j-- == 0)
 702                         break;
 703                 cleanup_match(ematch, net);
 704         }
 705         return ret;
 706 }
 707
 708 static bool check_underflow(const struct ipt_entry *e)
 709 {
 710         const struct xt_entry_target *t;
 711         unsigned int verdict;
 712
 713         if (!unconditional(&e->ip))
 714                 return false;
 715         t = ipt_get_target_c(e);
 716         if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
 717                 return false;
 718         verdict = ((struct xt_standard_target *)t)->verdict;
 719         verdict = -verdict - 1;
 720         return verdict == NF_DROP || verdict == NF_ACCEPT;
 721 }
 722
 723 static int
 724 check_entry_size_and_hooks(struct ipt_entry *e,
 725                            struct xt_table_info *newinfo,
 726                            const unsigned char *base,
 727                            const unsigned char *limit,
 728                            const unsigned int *hook_entries,
 729                            const unsigned int *underflows,
 730                            unsigned int valid_hooks)
 731 {
 732         unsigned int h;
 733
 734         if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 ||
 735             (unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
 736                 duprintf("Bad offset %p\n", e);
 737                 return -EINVAL;
 738         }
 739
 740         if (e->next_offset
 741             < sizeof(struct ipt_entry) + sizeof(struct xt_entry_target)) {
 742                 duprintf("checking: element %p size %u\n",
 743                          e, e->next_offset);
 744                 return -EINVAL;
 745         }
 746
 747         /* Check hooks & underflows */
 748         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
 749                 if (!(valid_hooks & (1 << h)))
 750                         continue;
 751                 if ((unsigned char *)e - base == hook_entries[h])
 752                         newinfo->hook_entry[h] = hook_entries[h];
 753                 if ((unsigned char *)e - base == underflows[h]) {
 754                         if (!check_underflow(e)) {
 755                                 pr_err("Underflows must be unconditional and "
 756                                        "use the STANDARD target with "
 757                                        "ACCEPT/DROP\n");
 758                                 return -EINVAL;
 759                         }
 760                         newinfo->underflow[h] = underflows[h];
 761                 }
 762         }
 763
 764         /* Clear counters and comefrom */
 765         e->counters = ((struct xt_counters) { 0, 0 });
 766         e->comefrom = 0;
 767         return 0;
 768 }
 769
 770 static void
 771 cleanup_entry(struct ipt_entry *e, struct net *net)
 772 {
 773         struct xt_tgdtor_param par;
 774         struct xt_entry_target *t;
 775         struct xt_entry_match *ematch;
 776
 777         /* Cleanup all matches */
 778         xt_ematch_foreach(ematch, e)
 779                 cleanup_match(ematch, net);
 780         t = ipt_get_target(e);
 781
 782         par.net      = net;
 783         par.target   = t->u.kernel.target;
 784         par.targinfo = t->data;
 785         par.family   = NFPROTO_IPV4;
 786         if (par.target->destroy != NULL)
 787                 par.target->destroy(&par);
 788         module_put(par.target->me);
 789 }
 790
 791 /* Checks and translates the user-supplied table segment (held in
 792    newinfo) */
 793 static int
 794 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
 795                 const struct ipt_replace *repl)
 796 {
 797         struct ipt_entry *iter;
 798         unsigned int i;
 799         int ret = 0;
 800
 801         newinfo->size = repl->size;
 802         newinfo->number = repl->num_entries;
 803
 804         /* Init all hooks to impossible value. */
 805         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 806                 newinfo->hook_entry[i] = 0xFFFFFFFF;
 807                 newinfo->underflow[i] = 0xFFFFFFFF;
 808         }
 809
 810         duprintf("translate_table: size %u\n", newinfo->size);
 811         i = 0;
 812         /* Walk through entries, checking offsets. */
 813         xt_entry_foreach(iter, entry0, newinfo->size) {
 814                 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
 815                                                  entry0 + repl->size,
 816                                                  repl->hook_entry,
 817                                                  repl->underflow,
 818                                                  repl->valid_hooks);
 819                 if (ret != 0)
 820                         return ret;
 821                 ++i;
 822                 if (strcmp(ipt_get_target(iter)->u.user.name,
 823                     XT_ERROR_TARGET) == 0)
 824                         ++newinfo->stacksize;
 825         }
 826
 827         if (i != repl->num_entries) {
 828                 duprintf("translate_table: %u not %u entries\n",
 829                          i, repl->num_entries);
 830                 return -EINVAL;
 831         }
 832
 833         /* Check hooks all assigned */
 834         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 835                 /* Only hooks which are valid */
 836                 if (!(repl->valid_hooks & (1 << i)))
 837                         continue;
 838                 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
 839                         duprintf("Invalid hook entry %u %u\n",
 840                                  i, repl->hook_entry[i]);
 841                         return -EINVAL;
 842                 }
 843                 if (newinfo->underflow[i] == 0xFFFFFFFF) {
 844                         duprintf("Invalid underflow %u %u\n",
 845                                  i, repl->underflow[i]);
 846                         return -EINVAL;
 847                 }
 848         }
 849
 850         if (!mark_source_chains(newinfo, repl->valid_hooks, entry0))
 851                 return -ELOOP;
 852
 853         /* Finally, each sanity check must pass */
 854         i = 0;
 855         xt_entry_foreach(iter, entry0, newinfo->size) {
 856                 ret = find_check_entry(iter, net, repl->name, repl->size);
 857                 if (ret != 0)
 858                         break;
 859                 ++i;
 860         }
 861
 862         if (ret != 0) {
 863                 xt_entry_foreach(iter, entry0, newinfo->size) {
 864                         if (i-- == 0)
 865                                 break;
 866                         cleanup_entry(iter, net);
 867                 }
 868                 return ret;
 869         }
 870
 871         /* And one copy for every other CPU */
 872         for_each_possible_cpu(i) {
 873                 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
 874                         memcpy(newinfo->entries[i], entry0, newinfo->size);
 875         }
 876
 877         return ret;
 878 }
 879
 880 static void
 881 get_counters(const struct xt_table_info *t,
 882              struct xt_counters counters[])
 883 {
 884         struct ipt_entry *iter;
 885         unsigned int cpu;
 886         unsigned int i;
 887
 888         for_each_possible_cpu(cpu) {
 889                 seqlock_t *lock = &per_cpu(xt_info_locks, cpu).lock;
 890
 891                 i = 0;
 892                 xt_entry_foreach(iter, t->entries[cpu], t->size) {
 893                         u64 bcnt, pcnt;
 894                         unsigned int start;
 895
 896                         do {
 897                                 start = read_seqbegin(lock);
 898                                 bcnt = iter->counters.bcnt;
 899                                 pcnt = iter->counters.pcnt;
 900                         } while (read_seqretry(lock, start));
 901
 902                         ADD_COUNTER(counters[i], bcnt, pcnt);
 903                         ++i; /* macro does multi eval of i */
 904                 }
 905         }
 906 }
 907
 908 static struct xt_counters *alloc_counters(const struct xt_table *table)
 909 {
 910         unsigned int countersize;
 911         struct xt_counters *counters;
 912         const struct xt_table_info *private = table->private;
 913
 914         /* We need atomic snapshot of counters: rest doesn't change
 915            (other than comefrom, which userspace doesn't care
 916            about). */
 917         countersize = sizeof(struct xt_counters) * private->number;
 918         counters = vzalloc(countersize);
 919
 920         if (counters == NULL)
 921                 return ERR_PTR(-ENOMEM);
 922
 923         get_counters(private, counters);
 924
 925         return counters;
 926 }
 927
 928 static int
 929 copy_entries_to_user(unsigned int total_size,
 930                      const struct xt_table *table,
 931                      void __user *userptr)
 932 {
 933         unsigned int off, num;
 934         const struct ipt_entry *e;
 935         struct xt_counters *counters;
 936         const struct xt_table_info *private = table->private;
 937         int ret = 0;
 938         const void *loc_cpu_entry;
 939
 940         counters = alloc_counters(table);
 941         if (IS_ERR(counters))
 942                 return PTR_ERR(counters);
 943
 944         /* choose the copy that is on our node/cpu, ...
 945          * This choice is lazy (because current thread is
 946          * allowed to migrate to another cpu)
 947          */
 948         loc_cpu_entry = private->entries[raw_smp_processor_id()];
 949         if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
 950                 ret = -EFAULT;
 951                 goto free_counters;
 952         }
 953
 954         /* FIXME: use iterator macros --RR */
 955         /* ... then go back and fix counters and names */
 956         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
 957                 unsigned int i;
 958                 const struct xt_entry_match *m;
 959                 const struct xt_entry_target *t;
 960
 961                 e = (struct ipt_entry *)(loc_cpu_entry + off);
 962                 if (copy_to_user(userptr + off
 963                                  + offsetof(struct ipt_entry, counters),
 964                                  &counters[num],
 965                                  sizeof(counters[num])) != 0) {
 966                         ret = -EFAULT;
 967                         goto free_counters;
 968                 }
 969
 970                 for (i = sizeof(struct ipt_entry);
 971                      i < e->target_offset;
 972                      i += m->u.match_size) {
 973                         m = (void *)e + i;
 974
 975                         if (copy_to_user(userptr + off + i
 976                                          + offsetof(struct xt_entry_match,
 977                                                     u.user.name),
 978                                          m->u.kernel.match->name,
 979                                          strlen(m->u.kernel.match->name)+1)
 980                             != 0) {
 981                                 ret = -EFAULT;
 982                                 goto free_counters;
 983                         }
 984                 }
 985
 986                 t = ipt_get_target_c(e);
 987                 if (copy_to_user(userptr + off + e->target_offset
 988                                  + offsetof(struct xt_entry_target,
 989                                             u.user.name),
 990                                  t->u.kernel.target->name,
 991                                  strlen(t->u.kernel.target->name)+1) != 0) {
 992                         ret = -EFAULT;
 993                         goto free_counters;
 994                 }
 995         }
 996
 997  free_counters:
 998         vfree(counters);
 999         return ret;
1000 }
1001
1002 #ifdef CONFIG_COMPAT
1003 static void compat_standard_from_user(void *dst, const void *src)
1004 {
1005         int v = *(compat_int_t *)src;
1006
1007         if (v > 0)
1008                 v += xt_compat_calc_jump(AF_INET, v);
1009         memcpy(dst, &v, sizeof(v));
1010 }
1011
1012 static int compat_standard_to_user(void __user *dst, const void *src)
1013 {
1014         compat_int_t cv = *(int *)src;
1015
1016         if (cv > 0)
1017                 cv -= xt_compat_calc_jump(AF_INET, cv);
1018         return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
1019 }
1020
1021 static int compat_calc_entry(const struct ipt_entry *e,
1022                              const struct xt_table_info *info,
1023                              const void *base, struct xt_table_info *newinfo)
1024 {
1025         const struct xt_entry_match *ematch;
1026         const struct xt_entry_target *t;
1027         unsigned int entry_offset;
1028         int off, i, ret;
1029
1030         off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1031         entry_offset = (void *)e - base;
1032         xt_ematch_foreach(ematch, e)
1033                 off += xt_compat_match_offset(ematch->u.kernel.match);
1034         t = ipt_get_target_c(e);
1035         off += xt_compat_target_offset(t->u.kernel.target);
1036         newinfo->size -= off;
1037         ret = xt_compat_add_offset(AF_INET, entry_offset, off);
1038         if (ret)
1039                 return ret;
1040
1041         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1042                 if (info->hook_entry[i] &&
1043                     (e < (struct ipt_entry *)(base + info->hook_entry[i])))
1044                         newinfo->hook_entry[i] -= off;
1045                 if (info->underflow[i] &&
1046                     (e < (struct ipt_entry *)(base + info->underflow[i])))
1047                         newinfo->underflow[i] -= off;
1048         }
1049         return 0;
1050 }
1051
1052 static int compat_table_info(const struct xt_table_info *info,
1053                              struct xt_table_info *newinfo)
1054 {
1055         struct ipt_entry *iter;
1056         void *loc_cpu_entry;
1057         int ret;
1058
1059         if (!newinfo || !info)
1060                 return -EINVAL;
1061
1062         /* we dont care about newinfo->entries[] */
1063         memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
1064         newinfo->initial_entries = 0;
1065         loc_cpu_entry = info->entries[raw_smp_processor_id()];
1066         xt_entry_foreach(iter, loc_cpu_entry, info->size) {
1067                 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
1068                 if (ret != 0)
1069                         return ret;
1070         }
1071         return 0;
1072 }
1073 #endif
1074
1075 static int get_info(struct net *net, void __user *user,
1076                     const int *len, int compat)
1077 {
1078         char name[XT_TABLE_MAXNAMELEN];
1079         struct xt_table *t;
1080         int ret;
1081
1082         if (*len != sizeof(struct ipt_getinfo)) {
1083                 duprintf("length %u != %zu\n", *len,
1084                          sizeof(struct ipt_getinfo));
1085                 return -EINVAL;
1086         }
1087
1088         if (copy_from_user(name, user, sizeof(name)) != 0)
1089                 return -EFAULT;
1090
1091         name[XT_TABLE_MAXNAMELEN-1] = '\0';
1092 #ifdef CONFIG_COMPAT
1093         if (compat)
1094                 xt_compat_lock(AF_INET);
1095 #endif
1096         t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
1097                                     "iptable_%s", name);
1098         if (t && !IS_ERR(t)) {
1099                 struct ipt_getinfo info;
1100                 const struct xt_table_info *private = t->private;
1101 #ifdef CONFIG_COMPAT
1102                 struct xt_table_info tmp;
1103
1104                 if (compat) {
1105                         ret = compat_table_info(private, &tmp);
1106                         xt_compat_flush_offsets(AF_INET);
1107                         private = &tmp;
1108                 }
1109 #endif
1110                 memset(&info, 0, sizeof(info));
1111                 info.valid_hooks = t->valid_hooks;
1112                 memcpy(info.hook_entry, private->hook_entry,
1113                        sizeof(info.hook_entry));
1114                 memcpy(info.underflow, private->underflow,
1115                        sizeof(info.underflow));
1116                 info.num_entries = private->number;
1117                 info.size = private->size;
1118                 strcpy(info.name, name);
1119
1120                 if (copy_to_user(user, &info, *len) != 0)
1121                         ret = -EFAULT;
1122                 else
1123                         ret = 0;
1124
1125                 xt_table_unlock(t);
1126                 module_put(t->me);
1127         } else
1128                 ret = t ? PTR_ERR(t) : -ENOENT;
1129 #ifdef CONFIG_COMPAT
1130         if (compat)
1131                 xt_compat_unlock(AF_INET);
1132 #endif
1133         return ret;
1134 }
1135
1136 static int
1137 get_entries(struct net *net, struct ipt_get_entries __user *uptr,
1138             const int *len)
1139 {
1140         int ret;
1141         struct ipt_get_entries get;
1142         struct xt_table *t;
1143
1144         if (*len < sizeof(get)) {
1145                 duprintf("get_entries: %u < %zu\n", *len, sizeof(get));
1146                 return -EINVAL;
1147         }
1148         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1149                 return -EFAULT;
1150         if (*len != sizeof(struct ipt_get_entries) + get.size) {
1151                 duprintf("get_entries: %u != %zu\n",
1152                          *len, sizeof(get) + get.size);
1153                 return -EINVAL;
1154         }
1155
1156         t = xt_find_table_lock(net, AF_INET, get.name);
1157         if (t && !IS_ERR(t)) {
1158                 const struct xt_table_info *private = t->private;
1159                 duprintf("t->private->number = %u\n", private->number);
1160                 if (get.size == private->size)
1161                         ret = copy_entries_to_user(private->size,
1162                                                    t, uptr->entrytable);
1163                 else {
1164                         duprintf("get_entries: I've got %u not %u!\n",
1165                                  private->size, get.size);
1166                         ret = -EAGAIN;
1167                 }
1168                 module_put(t->me);
1169                 xt_table_unlock(t);
1170         } else
1171                 ret = t ? PTR_ERR(t) : -ENOENT;
1172
1173         return ret;
1174 }
1175
1176 static int
1177 __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1178              struct xt_table_info *newinfo, unsigned int num_counters,
1179              void __user *counters_ptr)
1180 {
1181         int ret;
1182         struct xt_table *t;
1183         struct xt_table_info *oldinfo;
1184         struct xt_counters *counters;
1185         void *loc_cpu_old_entry;
1186         struct ipt_entry *iter;
1187
1188         ret = 0;
1189         counters = vzalloc(num_counters * sizeof(struct xt_counters));
1190         if (!counters) {
1191                 ret = -ENOMEM;
1192                 goto out;
1193         }
1194
1195         t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
1196                                     "iptable_%s", name);
1197         if (!t || IS_ERR(t)) {
1198                 ret = t ? PTR_ERR(t) : -ENOENT;
1199                 goto free_newinfo_counters_untrans;
1200         }
1201
1202         /* You lied! */
1203         if (valid_hooks != t->valid_hooks) {
1204                 duprintf("Valid hook crap: %08X vs %08X\n",
1205                          valid_hooks, t->valid_hooks);
1206                 ret = -EINVAL;
1207                 goto put_module;
1208         }
1209
1210         oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1211         if (!oldinfo)
1212                 goto put_module;
1213
1214         /* Update module usage count based on number of rules */
1215         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1216                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1217         if ((oldinfo->number > oldinfo->initial_entries) ||
1218             (newinfo->number <= oldinfo->initial_entries))
1219                 module_put(t->me);
1220         if ((oldinfo->number > oldinfo->initial_entries) &&
1221             (newinfo->number <= oldinfo->initial_entries))
1222                 module_put(t->me);
1223
1224         /* Get the old counters, and synchronize with replace */
1225         get_counters(oldinfo, counters);
1226
1227         /* Decrease module usage counts and free resource */
1228         loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1229         xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
1230                 cleanup_entry(iter, net);
1231
1232         xt_free_table_info(oldinfo);
1233         if (copy_to_user(counters_ptr, counters,
1234                          sizeof(struct xt_counters) * num_counters) != 0)
1235                 ret = -EFAULT;
1236         vfree(counters);
1237         xt_table_unlock(t);
1238         return ret;
1239
1240  put_module:
1241         module_put(t->me);
1242         xt_table_unlock(t);
1243  free_newinfo_counters_untrans:
1244         vfree(counters);
1245  out:
1246         return ret;
1247 }
1248
1249 static int
1250 do_replace(struct net *net, const void __user *user, unsigned int len)
1251 {
1252         int ret;
1253         struct ipt_replace tmp;
1254         struct xt_table_info *newinfo;
1255         void *loc_cpu_entry;
1256         struct ipt_entry *iter;
1257
1258         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1259                 return -EFAULT;
1260
1261         /* overflow check */
1262         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1263                 return -ENOMEM;
1264
1265         newinfo = xt_alloc_table_info(tmp.size);
1266         if (!newinfo)
1267                 return -ENOMEM;
1268
1269         /* choose the copy that is on our node/cpu */
1270         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1271         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1272                            tmp.size) != 0) {
1273                 ret = -EFAULT;
1274                 goto free_newinfo;
1275         }
1276
1277         ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
1278         if (ret != 0)
1279                 goto free_newinfo;
1280
1281         duprintf("Translated table\n");
1282
1283         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1284                            tmp.num_counters, tmp.counters);
1285         if (ret)
1286                 goto free_newinfo_untrans;
1287         return 0;
1288
1289  free_newinfo_untrans:
1290         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1291                 cleanup_entry(iter, net);
1292  free_newinfo:
1293         xt_free_table_info(newinfo);
1294         return ret;
1295 }
1296
1297 static int
1298 do_add_counters(struct net *net, const void __user *user,
1299                 unsigned int len, int compat)
1300 {
1301         unsigned int i, curcpu;
1302         struct xt_counters_info tmp;
1303         struct xt_counters *paddc;
1304         unsigned int num_counters;
1305         const char *name;
1306         int size;
1307         void *ptmp;
1308         struct xt_table *t;
1309         const struct xt_table_info *private;
1310         int ret = 0;
1311         void *loc_cpu_entry;
1312         struct ipt_entry *iter;
1313 #ifdef CONFIG_COMPAT
1314         struct compat_xt_counters_info compat_tmp;
1315
1316         if (compat) {
1317                 ptmp = &compat_tmp;
1318                 size = sizeof(struct compat_xt_counters_info);
1319         } else
1320 #endif
1321         {
1322                 ptmp = &tmp;
1323                 size = sizeof(struct xt_counters_info);
1324         }
1325
1326         if (copy_from_user(ptmp, user, size) != 0)
1327                 return -EFAULT;
1328
1329 #ifdef CONFIG_COMPAT
1330         if (compat) {
1331                 num_counters = compat_tmp.num_counters;
1332                 name = compat_tmp.name;
1333         } else
1334 #endif
1335         {
1336                 num_counters = tmp.num_counters;
1337                 name = tmp.name;
1338         }
1339
1340         if (len != size + num_counters * sizeof(struct xt_counters))
1341                 return -EINVAL;
1342
1343         paddc = vmalloc(len - size);
1344         if (!paddc)
1345                 return -ENOMEM;
1346
1347         if (copy_from_user(paddc, user + size, len - size) != 0) {
1348                 ret = -EFAULT;
1349                 goto free;
1350         }
1351
1352         t = xt_find_table_lock(net, AF_INET, name);
1353         if (!t || IS_ERR(t)) {
1354                 ret = t ? PTR_ERR(t) : -ENOENT;
1355                 goto free;
1356         }
1357
1358         local_bh_disable();
1359         private = t->private;
1360         if (private->number != num_counters) {
1361                 ret = -EINVAL;
1362                 goto unlock_up_free;
1363         }
1364
1365         i = 0;
1366         /* Choose the copy that is on our node */
1367         curcpu = smp_processor_id();
1368         loc_cpu_entry = private->entries[curcpu];
1369         xt_info_wrlock(curcpu);
1370         xt_entry_foreach(iter, loc_cpu_entry, private->size) {
1371                 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
1372                 ++i;
1373         }
1374         xt_info_wrunlock(curcpu);
1375  unlock_up_free:
1376         local_bh_enable();
1377         xt_table_unlock(t);
1378         module_put(t->me);
1379  free:
1380         vfree(paddc);
1381
1382         return ret;
1383 }
1384
1385 #ifdef CONFIG_COMPAT
1386 struct compat_ipt_replace {
1387         char                    name[XT_TABLE_MAXNAMELEN];
1388         u32                     valid_hooks;
1389         u32                     num_entries;
1390         u32                     size;
1391         u32                     hook_entry[NF_INET_NUMHOOKS];
1392         u32                     underflow[NF_INET_NUMHOOKS];
1393         u32                     num_counters;
1394         compat_uptr_t           counters;       /* struct xt_counters * */
1395         struct compat_ipt_entry entries[0];
1396 };
1397
1398 static int
1399 compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
1400                           unsigned int *size, struct xt_counters *counters,
1401                           unsigned int i)
1402 {
1403         struct xt_entry_target *t;
1404         struct compat_ipt_entry __user *ce;
1405         u_int16_t target_offset, next_offset;
1406         compat_uint_t origsize;
1407         const struct xt_entry_match *ematch;
1408         int ret = 0;
1409
1410         origsize = *size;
1411         ce = (struct compat_ipt_entry __user *)*dstptr;
1412         if (copy_to_user(ce, e, sizeof(struct ipt_entry)) != 0 ||
1413             copy_to_user(&ce->counters, &counters[i],
1414             sizeof(counters[i])) != 0)
1415                 return -EFAULT;
1416
1417         *dstptr += sizeof(struct compat_ipt_entry);
1418         *size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1419
1420         xt_ematch_foreach(ematch, e) {
1421                 ret = xt_compat_match_to_user(ematch, dstptr, size);
1422                 if (ret != 0)
1423                         return ret;
1424         }
1425         target_offset = e->target_offset - (origsize - *size);
1426         t = ipt_get_target(e);
1427         ret = xt_compat_target_to_user(t, dstptr, size);
1428         if (ret)
1429                 return ret;
1430         next_offset = e->next_offset - (origsize - *size);
1431         if (put_user(target_offset, &ce->target_offset) != 0 ||
1432             put_user(next_offset, &ce->next_offset) != 0)
1433                 return -EFAULT;
1434         return 0;
1435 }
1436
1437 static int
1438 compat_find_calc_match(struct xt_entry_match *m,
1439                        const char *name,
1440                        const struct ipt_ip *ip,
1441                        unsigned int hookmask,
1442                        int *size)
1443 {
1444         struct xt_match *match;
1445
1446         match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
1447                                       m->u.user.revision);
1448         if (IS_ERR(match)) {
1449                 duprintf("compat_check_calc_match: `%s' not found\n",
1450                          m->u.user.name);
1451                 return PTR_ERR(match);
1452         }
1453         m->u.kernel.match = match;
1454         *size += xt_compat_match_offset(match);
1455         return 0;
1456 }
1457
1458 static void compat_release_entry(struct compat_ipt_entry *e)
1459 {
1460         struct xt_entry_target *t;
1461         struct xt_entry_match *ematch;
1462
1463         /* Cleanup all matches */
1464         xt_ematch_foreach(ematch, e)
1465                 module_put(ematch->u.kernel.match->me);
1466         t = compat_ipt_get_target(e);
1467         module_put(t->u.kernel.target->me);
1468 }
1469
1470 static int
1471 check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
1472                                   struct xt_table_info *newinfo,
1473                                   unsigned int *size,
1474                                   const unsigned char *base,
1475                                   const unsigned char *limit,
1476                                   const unsigned int *hook_entries,
1477                                   const unsigned int *underflows,
1478                                   const char *name)
1479 {
1480         struct xt_entry_match *ematch;
1481         struct xt_entry_target *t;
1482         struct xt_target *target;
1483         unsigned int entry_offset;
1484         unsigned int j;
1485         int ret, off, h;
1486
1487         duprintf("check_compat_entry_size_and_hooks %p\n", e);
1488         if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 ||
1489             (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) {
1490                 duprintf("Bad offset %p, limit = %p\n", e, limit);
1491                 return -EINVAL;
1492         }
1493
1494         if (e->next_offset < sizeof(struct compat_ipt_entry) +
1495                              sizeof(struct compat_xt_entry_target)) {
1496                 duprintf("checking: element %p size %u\n",
1497                          e, e->next_offset);
1498                 return -EINVAL;
1499         }
1500
1501         /* For purposes of check_entry casting the compat entry is fine */
1502         ret = check_entry((struct ipt_entry *)e, name);
1503         if (ret)
1504                 return ret;
1505
1506         off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1507         entry_offset = (void *)e - (void *)base;
1508         j = 0;
1509         xt_ematch_foreach(ematch, e) {
1510                 ret = compat_find_calc_match(ematch, name,
1511                                              &e->ip, e->comefrom, &off);
1512                 if (ret != 0)
1513                         goto release_matches;
1514                 ++j;
1515         }
1516
1517         t = compat_ipt_get_target(e);
1518         target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
1519                                         t->u.user.revision);
1520         if (IS_ERR(target)) {
1521                 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1522                          t->u.user.name);
1523                 ret = PTR_ERR(target);
1524                 goto release_matches;
1525         }
1526         t->u.kernel.target = target;
1527
1528         off += xt_compat_target_offset(target);
1529         *size += off;
1530         ret = xt_compat_add_offset(AF_INET, entry_offset, off);
1531         if (ret)
1532                 goto out;
1533
1534         /* Check hooks & underflows */
1535         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1536                 if ((unsigned char *)e - base == hook_entries[h])
1537                         newinfo->hook_entry[h] = hook_entries[h];
1538                 if ((unsigned char *)e - base == underflows[h])
1539                         newinfo->underflow[h] = underflows[h];
1540         }
1541
1542         /* Clear counters and comefrom */
1543         memset(&e->counters, 0, sizeof(e->counters));
1544         e->comefrom = 0;
1545         return 0;
1546
1547 out:
1548         module_put(t->u.kernel.target->me);
1549 release_matches:
1550         xt_ematch_foreach(ematch, e) {
1551                 if (j-- == 0)
1552                         break;
1553                 module_put(ematch->u.kernel.match->me);
1554         }
1555         return ret;
1556 }
1557
1558 static int
1559 compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
1560                             unsigned int *size, const char *name,
1561                             struct xt_table_info *newinfo, unsigned char *base)
1562 {
1563         struct xt_entry_target *t;
1564         struct xt_target *target;
1565         struct ipt_entry *de;
1566         unsigned int origsize;
1567         int ret, h;
1568         struct xt_entry_match *ematch;
1569
1570         ret = 0;
1571         origsize = *size;
1572         de = (struct ipt_entry *)*dstptr;
1573         memcpy(de, e, sizeof(struct ipt_entry));
1574         memcpy(&de->counters, &e->counters, sizeof(e->counters));
1575
1576         *dstptr += sizeof(struct ipt_entry);
1577         *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1578
1579         xt_ematch_foreach(ematch, e) {
1580                 ret = xt_compat_match_from_user(ematch, dstptr, size);
1581                 if (ret != 0)
1582                         return ret;
1583         }
1584         de->target_offset = e->target_offset - (origsize - *size);
1585         t = compat_ipt_get_target(e);
1586         target = t->u.kernel.target;
1587         xt_compat_target_from_user(t, dstptr, size);
1588
1589         de->next_offset = e->next_offset - (origsize - *size);
1590         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1591                 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1592                         newinfo->hook_entry[h] -= origsize - *size;
1593                 if ((unsigned char *)de - base < newinfo->underflow[h])
1594                         newinfo->underflow[h] -= origsize - *size;
1595         }
1596         return ret;
1597 }
1598
1599 static int
1600 compat_check_entry(struct ipt_entry *e, struct net *net, const char *name)
1601 {
1602         struct xt_entry_match *ematch;
1603         struct xt_mtchk_param mtpar;
1604         unsigned int j;
1605         int ret = 0;
1606
1607         j = 0;
1608         mtpar.net       = net;
1609         mtpar.table     = name;
1610         mtpar.entryinfo = &e->ip;
1611         mtpar.hook_mask = e->comefrom;
1612         mtpar.family    = NFPROTO_IPV4;
1613         xt_ematch_foreach(ematch, e) {
1614                 ret = check_match(ematch, &mtpar);
1615                 if (ret != 0)
1616                         goto cleanup_matches;
1617                 ++j;
1618         }
1619
1620         ret = check_target(e, net, name);
1621         if (ret)
1622                 goto cleanup_matches;
1623         return 0;
1624
1625  cleanup_matches:
1626         xt_ematch_foreach(ematch, e) {
1627                 if (j-- == 0)
1628                         break;
1629                 cleanup_match(ematch, net);
1630         }
1631         return ret;
1632 }
1633
1634 static int
1635 translate_compat_table(struct net *net,
1636                        const char *name,
1637                        unsigned int valid_hooks,
1638                        struct xt_table_info **pinfo,
1639                        void **pentry0,
1640                        unsigned int total_size,
1641                        unsigned int number,
1642                        unsigned int *hook_entries,
1643                        unsigned int *underflows)
1644 {
1645         unsigned int i, j;
1646         struct xt_table_info *newinfo, *info;
1647         void *pos, *entry0, *entry1;
1648         struct compat_ipt_entry *iter0;
1649         struct ipt_entry *iter1;
1650         unsigned int size;
1651         int ret;
1652
1653         info = *pinfo;
1654         entry0 = *pentry0;
1655         size = total_size;
1656         info->number = number;
1657
1658         /* Init all hooks to impossible value. */
1659         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1660                 info->hook_entry[i] = 0xFFFFFFFF;
1661                 info->underflow[i] = 0xFFFFFFFF;
1662         }
1663
1664         duprintf("translate_compat_table: size %u\n", info->size);
1665         j = 0;
1666         xt_compat_lock(AF_INET);
1667         /* Walk through entries, checking offsets. */
1668         xt_entry_foreach(iter0, entry0, total_size) {
1669                 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1670                                                         entry0,
1671                                                         entry0 + total_size,
1672                                                         hook_entries,
1673                                                         underflows,
1674                                                         name);
1675                 if (ret != 0)
1676                         goto out_unlock;
1677                 ++j;
1678         }
1679
1680         ret = -EINVAL;
1681         if (j != number) {
1682                 duprintf("translate_compat_table: %u not %u entries\n",
1683                          j, number);
1684                 goto out_unlock;
1685         }
1686
1687         /* Check hooks all assigned */
1688         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1689                 /* Only hooks which are valid */
1690                 if (!(valid_hooks & (1 << i)))
1691                         continue;
1692                 if (info->hook_entry[i] == 0xFFFFFFFF) {
1693                         duprintf("Invalid hook entry %u %u\n",
1694                                  i, hook_entries[i]);
1695                         goto out_unlock;
1696                 }
1697                 if (info->underflow[i] == 0xFFFFFFFF) {
1698                         duprintf("Invalid underflow %u %u\n",
1699                                  i, underflows[i]);
1700                         goto out_unlock;
1701                 }
1702         }
1703
1704         ret = -ENOMEM;
1705         newinfo = xt_alloc_table_info(size);
1706         if (!newinfo)
1707                 goto out_unlock;
1708
1709         newinfo->number = number;
1710         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1711                 newinfo->hook_entry[i] = info->hook_entry[i];
1712                 newinfo->underflow[i] = info->underflow[i];
1713         }
1714         entry1 = newinfo->entries[raw_smp_processor_id()];
1715         pos = entry1;
1716         size = total_size;
1717         xt_entry_foreach(iter0, entry0, total_size) {
1718                 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1719                                                   name, newinfo, entry1);
1720                 if (ret != 0)
1721                         break;
1722         }
1723         xt_compat_flush_offsets(AF_INET);
1724         xt_compat_unlock(AF_INET);
1725         if (ret)
1726                 goto free_newinfo;
1727
1728         ret = -ELOOP;
1729         if (!mark_source_chains(newinfo, valid_hooks, entry1))
1730                 goto free_newinfo;
1731
1732         i = 0;
1733         xt_entry_foreach(iter1, entry1, newinfo->size) {
1734                 ret = compat_check_entry(iter1, net, name);
1735                 if (ret != 0)
1736                         break;
1737                 ++i;
1738                 if (strcmp(ipt_get_target(iter1)->u.user.name,
1739                     XT_ERROR_TARGET) == 0)
1740                         ++newinfo->stacksize;
1741         }
1742         if (ret) {
1743                 /*
1744                  * The first i matches need cleanup_entry (calls ->destroy)
1745                  * because they had called ->check already. The other j-i
1746                  * entries need only release.
1747                  */
1748                 int skip = i;
1749                 j -= i;
1750                 xt_entry_foreach(iter0, entry0, newinfo->size) {
1751                         if (skip-- > 0)
1752                                 continue;
1753                         if (j-- == 0)
1754                                 break;
1755                         compat_release_entry(iter0);
1756                 }
1757                 xt_entry_foreach(iter1, entry1, newinfo->size) {
1758                         if (i-- == 0)
1759                                 break;
1760                         cleanup_entry(iter1, net);
1761                 }
1762                 xt_free_table_info(newinfo);
1763                 return ret;
1764         }
1765
1766         /* And one copy for every other CPU */
1767         for_each_possible_cpu(i)
1768                 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1769                         memcpy(newinfo->entries[i], entry1, newinfo->size);
1770
1771         *pinfo = newinfo;
1772         *pentry0 = entry1;
1773         xt_free_table_info(info);
1774         return 0;
1775
1776 free_newinfo:
1777         xt_free_table_info(newinfo);
1778 out:
1779         xt_entry_foreach(iter0, entry0, total_size) {
1780                 if (j-- == 0)
1781                         break;
1782                 compat_release_entry(iter0);
1783         }
1784         return ret;
1785 out_unlock:
1786         xt_compat_flush_offsets(AF_INET);
1787         xt_compat_unlock(AF_INET);
1788         goto out;
1789 }
1790
1791 static int
1792 compat_do_replace(struct net *net, void __user *user, unsigned int len)
1793 {
1794         int ret;
1795         struct compat_ipt_replace tmp;
1796         struct xt_table_info *newinfo;
1797         void *loc_cpu_entry;
1798         struct ipt_entry *iter;
1799
1800         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1801                 return -EFAULT;
1802
1803         /* overflow check */
1804         if (tmp.size >= INT_MAX / num_possible_cpus())
1805                 return -ENOMEM;
1806         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1807                 return -ENOMEM;
1808
1809         newinfo = xt_alloc_table_info(tmp.size);
1810         if (!newinfo)
1811                 return -ENOMEM;
1812
1813         /* choose the copy that is on our node/cpu */
1814         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1815         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1816                            tmp.size) != 0) {
1817                 ret = -EFAULT;
1818                 goto free_newinfo;
1819         }
1820
1821         ret = translate_compat_table(net, tmp.name, tmp.valid_hooks,
1822                                      &newinfo, &loc_cpu_entry, tmp.size,
1823                                      tmp.num_entries, tmp.hook_entry,
1824                                      tmp.underflow);
1825         if (ret != 0)
1826                 goto free_newinfo;
1827
1828         duprintf("compat_do_replace: Translated table\n");
1829
1830         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1831                            tmp.num_counters, compat_ptr(tmp.counters));
1832         if (ret)
1833                 goto free_newinfo_untrans;
1834         return 0;
1835
1836  free_newinfo_untrans:
1837         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1838                 cleanup_entry(iter, net);
1839  free_newinfo:
1840         xt_free_table_info(newinfo);
1841         return ret;
1842 }
1843
1844 static int
1845 compat_do_ipt_set_ctl(struct sock *sk,  int cmd, void __user *user,
1846                       unsigned int len)
1847 {
1848         int ret;
1849
1850         if (!capable(CAP_NET_ADMIN))
1851                 return -EPERM;
1852
1853         switch (cmd) {
1854         case IPT_SO_SET_REPLACE:
1855                 ret = compat_do_replace(sock_net(sk), user, len);
1856                 break;
1857
1858         case IPT_SO_SET_ADD_COUNTERS:
1859                 ret = do_add_counters(sock_net(sk), user, len, 1);
1860                 break;
1861
1862         default:
1863                 duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
1864                 ret = -EINVAL;
1865         }
1866
1867         return ret;
1868 }
1869
1870 struct compat_ipt_get_entries {
1871         char name[XT_TABLE_MAXNAMELEN];
1872         compat_uint_t size;
1873         struct compat_ipt_entry entrytable[0];
1874 };
1875
1876 static int
1877 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1878                             void __user *userptr)
1879 {
1880         struct xt_counters *counters;
1881         const struct xt_table_info *private = table->private;
1882         void __user *pos;
1883         unsigned int size;
1884         int ret = 0;
1885         const void *loc_cpu_entry;
1886         unsigned int i = 0;
1887         struct ipt_entry *iter;
1888
1889         counters = alloc_counters(table);
1890         if (IS_ERR(counters))
1891                 return PTR_ERR(counters);
1892
1893         /* choose the copy that is on our node/cpu, ...
1894          * This choice is lazy (because current thread is
1895          * allowed to migrate to another cpu)
1896          */
1897         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1898         pos = userptr;
1899         size = total_size;
1900         xt_entry_foreach(iter, loc_cpu_entry, total_size) {
1901                 ret = compat_copy_entry_to_user(iter, &pos,
1902                                                 &size, counters, i++);
1903                 if (ret != 0)
1904                         break;
1905         }
1906
1907         vfree(counters);
1908         return ret;
1909 }
1910
1911 static int
1912 compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
1913                    int *len)
1914 {
1915         int ret;
1916         struct compat_ipt_get_entries get;
1917         struct xt_table *t;
1918
1919         if (*len < sizeof(get)) {
1920                 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1921                 return -EINVAL;
1922         }
1923
1924         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1925                 return -EFAULT;
1926
1927         if (*len != sizeof(struct compat_ipt_get_entries) + get.size) {
1928                 duprintf("compat_get_entries: %u != %zu\n",
1929                          *len, sizeof(get) + get.size);
1930                 return -EINVAL;
1931         }
1932
1933         xt_compat_lock(AF_INET);
1934         t = xt_find_table_lock(net, AF_INET, get.name);
1935         if (t && !IS_ERR(t)) {
1936                 const struct xt_table_info *private = t->private;
1937                 struct xt_table_info info;
1938                 duprintf("t->private->number = %u\n", private->number);
1939                 ret = compat_table_info(private, &info);
1940                 if (!ret && get.size == info.size) {
1941                         ret = compat_copy_entries_to_user(private->size,
1942                                                           t, uptr->entrytable);
1943                 } else if (!ret) {
1944                         duprintf("compat_get_entries: I've got %u not %u!\n",
1945                                  private->size, get.size);
1946                         ret = -EAGAIN;
1947                 }
1948                 xt_compat_flush_offsets(AF_INET);
1949                 module_put(t->me);
1950                 xt_table_unlock(t);
1951         } else
1952                 ret = t ? PTR_ERR(t) : -ENOENT;
1953
1954         xt_compat_unlock(AF_INET);
1955         return ret;
1956 }
1957
1958 static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
1959
1960 static int
1961 compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1962 {
1963         int ret;
1964
1965         if (!capable(CAP_NET_ADMIN))
1966                 return -EPERM;
1967
1968         switch (cmd) {
1969         case IPT_SO_GET_INFO:
1970                 ret = get_info(sock_net(sk), user, len, 1);
1971                 break;
1972         case IPT_SO_GET_ENTRIES:
1973                 ret = compat_get_entries(sock_net(sk), user, len);
1974                 break;
1975         default:
1976                 ret = do_ipt_get_ctl(sk, cmd, user, len);
1977         }
1978         return ret;
1979 }
1980 #endif
1981
1982 static int
1983 do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1984 {
1985         int ret;
1986
1987         if (!capable(CAP_NET_ADMIN))
1988                 return -EPERM;
1989
1990         switch (cmd) {
1991         case IPT_SO_SET_REPLACE:
1992                 ret = do_replace(sock_net(sk), user, len);
1993                 break;
1994
1995         case IPT_SO_SET_ADD_COUNTERS:
1996                 ret = do_add_counters(sock_net(sk), user, len, 0);
1997                 break;
1998
1999         default:
2000                 duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
2001                 ret = -EINVAL;
2002         }
2003
2004         return ret;
2005 }
2006
2007 static int
2008 do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2009 {
2010         int ret;
2011
2012         if (!capable(CAP_NET_ADMIN))
2013                 return -EPERM;
2014
2015         switch (cmd) {
2016         case IPT_SO_GET_INFO:
2017                 ret = get_info(sock_net(sk), user, len, 0);
2018                 break;
2019
2020         case IPT_SO_GET_ENTRIES:
2021                 ret = get_entries(sock_net(sk), user, len);
2022                 break;
2023
2024         case IPT_SO_GET_REVISION_MATCH:
2025         case IPT_SO_GET_REVISION_TARGET: {
2026                 struct xt_get_revision rev;
2027                 int target;
2028
2029                 if (*len != sizeof(rev)) {
2030                         ret = -EINVAL;
2031                         break;
2032                 }
2033                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
2034                         ret = -EFAULT;
2035                         break;
2036                 }
2037
2038                 if (cmd == IPT_SO_GET_REVISION_TARGET)
2039                         target = 1;
2040                 else
2041                         target = 0;
2042
2043                 try_then_request_module(xt_find_revision(AF_INET, rev.name,
2044                                                          rev.revision,
2045                                                          target, &ret),
2046                                         "ipt_%s", rev.name);
2047                 break;
2048         }
2049
2050         default:
2051                 duprintf("do_ipt_get_ctl: unknown request %i\n", cmd);
2052                 ret = -EINVAL;
2053         }
2054
2055         return ret;
2056 }
2057
2058 struct xt_table *ipt_register_table(struct net *net,
2059                                     const struct xt_table *table,
2060                                     const struct ipt_replace *repl)
2061 {
2062         int ret;
2063         struct xt_table_info *newinfo;
2064         struct xt_table_info bootstrap = {0};
2065         void *loc_cpu_entry;
2066         struct xt_table *new_table;
2067
2068         newinfo = xt_alloc_table_info(repl->size);
2069         if (!newinfo) {
2070                 ret = -ENOMEM;
2071                 goto out;
2072         }
2073
2074         /* choose the copy on our node/cpu, but dont care about preemption */
2075         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
2076         memcpy(loc_cpu_entry, repl->entries, repl->size);
2077
2078         ret = translate_table(net, newinfo, loc_cpu_entry, repl);
2079         if (ret != 0)
2080                 goto out_free;
2081
2082         new_table = xt_register_table(net, table, &bootstrap, newinfo);
2083         if (IS_ERR(new_table)) {
2084                 ret = PTR_ERR(new_table);
2085                 goto out_free;
2086         }
2087
2088         return new_table;
2089
2090 out_free:
2091         xt_free_table_info(newinfo);
2092 out:
2093         return ERR_PTR(ret);
2094 }
2095
2096 void ipt_unregister_table(struct net *net, struct xt_table *table)
2097 {
2098         struct xt_table_info *private;
2099         void *loc_cpu_entry;
2100         struct module *table_owner = table->me;
2101         struct ipt_entry *iter;
2102
2103         private = xt_unregister_table(table);
2104
2105         /* Decrease module usage counts and free resources */
2106         loc_cpu_entry = private->entries[raw_smp_processor_id()];
2107         xt_entry_foreach(iter, loc_cpu_entry, private->size)
2108                 cleanup_entry(iter, net);
2109         if (private->number > private->initial_entries)
2110                 module_put(table_owner);
2111         xt_free_table_info(private);
2112 }
2113
2114 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
2115 static inline bool
2116 icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
2117                      u_int8_t type, u_int8_t code,
2118                      bool invert)
2119 {
2120         return ((test_type == 0xFF) ||
2121                 (type == test_type && code >= min_code && code <= max_code))
2122                 ^ invert;
2123 }
2124
2125 static bool
2126 icmp_match(const struct sk_buff *skb, struct xt_action_param *par)
2127 {
2128         const struct icmphdr *ic;
2129         struct icmphdr _icmph;
2130         const struct ipt_icmp *icmpinfo = par->matchinfo;
2131
2132         /* Must not be a fragment. */
2133         if (par->fragoff != 0)
2134                 return false;
2135
2136         ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
2137         if (ic == NULL) {
2138                 /* We've been asked to examine this packet, and we
2139                  * can't.  Hence, no choice but to drop.
2140                  */
2141                 duprintf("Dropping evil ICMP tinygram.\n");
2142                 par->hotdrop = true;
2143                 return false;
2144         }
2145
2146         return icmp_type_code_match(icmpinfo->type,
2147                                     icmpinfo->code[0],
2148                                     icmpinfo->code[1],
2149                                     ic->type, ic->code,
2150                                     !!(icmpinfo->invflags&IPT_ICMP_INV));
2151 }
2152
2153 static int icmp_checkentry(const struct xt_mtchk_param *par)
2154 {
2155         const struct ipt_icmp *icmpinfo = par->matchinfo;
2156
2157         /* Must specify no unknown invflags */
2158         return (icmpinfo->invflags & ~IPT_ICMP_INV) ? -EINVAL : 0;
2159 }
2160
2161 static struct xt_target ipt_builtin_tg[] __read_mostly = {
2162         {
2163                 .name             = XT_STANDARD_TARGET,
2164                 .targetsize       = sizeof(int),
2165                 .family           = NFPROTO_IPV4,
2166 #ifdef CONFIG_COMPAT
2167                 .compatsize       = sizeof(compat_int_t),
2168                 .compat_from_user = compat_standard_from_user,
2169                 .compat_to_user   = compat_standard_to_user,
2170 #endif
2171         },
2172         {
2173                 .name             = XT_ERROR_TARGET,
2174                 .target           = ipt_error,
2175                 .targetsize       = XT_FUNCTION_MAXNAMELEN,
2176                 .family           = NFPROTO_IPV4,
2177         },
2178 };
2179
2180 static struct nf_sockopt_ops ipt_sockopts = {
2181         .pf             = PF_INET,
2182         .set_optmin     = IPT_BASE_CTL,
2183         .set_optmax     = IPT_SO_SET_MAX+1,
2184         .set            = do_ipt_set_ctl,
2185 #ifdef CONFIG_COMPAT
2186         .compat_set     = compat_do_ipt_set_ctl,
2187 #endif
2188         .get_optmin     = IPT_BASE_CTL,
2189         .get_optmax     = IPT_SO_GET_MAX+1,
2190         .get            = do_ipt_get_ctl,
2191 #ifdef CONFIG_COMPAT
2192         .compat_get     = compat_do_ipt_get_ctl,
2193 #endif
2194         .owner          = THIS_MODULE,
2195 };
2196
2197 static struct xt_match ipt_builtin_mt[] __read_mostly = {
2198         {
2199                 .name       = "icmp",
2200                 .match      = icmp_match,
2201                 .matchsize  = sizeof(struct ipt_icmp),
2202                 .checkentry = icmp_checkentry,
2203                 .proto      = IPPROTO_ICMP,
2204                 .family     = NFPROTO_IPV4,
2205         },
2206 };
2207
2208 static int __net_init ip_tables_net_init(struct net *net)
2209 {
2210         return xt_proto_init(net, NFPROTO_IPV4);
2211 }
2212
2213 static void __net_exit ip_tables_net_exit(struct net *net)
2214 {
2215         xt_proto_fini(net, NFPROTO_IPV4);
2216 }
2217
2218 static struct pernet_operations ip_tables_net_ops = {
2219         .init = ip_tables_net_init,
2220         .exit = ip_tables_net_exit,
2221 };
2222
2223 static int __init ip_tables_init(void)
2224 {
2225         int ret;
2226
2227         ret = register_pernet_subsys(&ip_tables_net_ops);
2228         if (ret < 0)
2229                 goto err1;
2230
2231         /* Noone else will be downing sem now, so we won't sleep */
2232         ret = xt_register_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
2233         if (ret < 0)
2234                 goto err2;
2235         ret = xt_register_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
2236         if (ret < 0)
2237                 goto err4;
2238
2239         /* Register setsockopt */
2240         ret = nf_register_sockopt(&ipt_sockopts);
2241         if (ret < 0)
2242                 goto err5;
2243
2244         pr_info("(C) 2000-2006 Netfilter Core Team\n");
2245         return 0;
2246
2247 err5:
2248         xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
2249 err4:
2250         xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
2251 err2:
2252         unregister_pernet_subsys(&ip_tables_net_ops);
2253 err1:
2254         return ret;
2255 }
2256
2257 static void __exit ip_tables_fini(void)
2258 {
2259         nf_unregister_sockopt(&ipt_sockopts);
2260
2261         xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
2262         xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
2263         unregister_pernet_subsys(&ip_tables_net_ops);
2264 }
2265
2266 EXPORT_SYMBOL(ipt_register_table);
2267 EXPORT_SYMBOL(ipt_unregister_table);
2268 EXPORT_SYMBOL(ipt_do_table);
2269 module_init(ip_tables_init);
2270 module_exit(ip_tables_fini);