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   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 #include <linux/cache.h>
  12 #include <linux/capability.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/kmod.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/module.h>
  18 #include <linux/icmp.h>
  19 #include <net/ip.h>
  20 #include <net/compat.h>
  21 #include <asm/uaccess.h>
  22 #include <linux/mutex.h>
  23 #include <linux/proc_fs.h>
  24 #include <linux/err.h>
  25 #include <linux/cpumask.h>
  26
  27 #include <linux/netfilter/x_tables.h>
  28 #include <linux/netfilter_ipv4/ip_tables.h>
  29
  30 MODULE_LICENSE("GPL");
  31 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  32 MODULE_DESCRIPTION("IPv4 packet filter");
  33
  34 /*#define DEBUG_IP_FIREWALL*/
  35 /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
  36 /*#define DEBUG_IP_FIREWALL_USER*/
  37
  38 #ifdef DEBUG_IP_FIREWALL
  39 #define dprintf(format, args...)  printk(format , ## args)
  40 #else
  41 #define dprintf(format, args...)
  42 #endif
  43
  44 #ifdef DEBUG_IP_FIREWALL_USER
  45 #define duprintf(format, args...) printk(format , ## args)
  46 #else
  47 #define duprintf(format, args...)
  48 #endif
  49
  50 #ifdef CONFIG_NETFILTER_DEBUG
  51 #define IP_NF_ASSERT(x)                                         \
  52 do {                                                            \
  53         if (!(x))                                               \
  54                 printk("IP_NF_ASSERT: %s:%s:%u\n",              \
  55                        __FUNCTION__, __FILE__, __LINE__);       \
  56 } while(0)
  57 #else
  58 #define IP_NF_ASSERT(x)
  59 #endif
  60
  61 #if 0
  62 /* All the better to debug you with... */
  63 #define static
  64 #define inline
  65 #endif
  66
  67 /*
  68    We keep a set of rules for each CPU, so we can avoid write-locking
  69    them in the softirq when updating the counters and therefore
  70    only need to read-lock in the softirq; doing a write_lock_bh() in user
  71    context stops packets coming through and allows user context to read
  72    the counters or update the rules.
  73
  74    Hence the start of any table is given by get_table() below.  */
  75
  76 /* Returns whether matches rule or not. */
  77 static inline int
  78 ip_packet_match(const struct iphdr *ip,
  79                 const char *indev,
  80                 const char *outdev,
  81                 const struct ipt_ip *ipinfo,
  82                 int isfrag)
  83 {
  84         size_t i;
  85         unsigned long ret;
  86
  87 #define FWINV(bool,invflg) ((bool) ^ !!(ipinfo->invflags & invflg))
  88
  89         if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
  90                   IPT_INV_SRCIP)
  91             || FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
  92                      IPT_INV_DSTIP)) {
  93                 dprintf("Source or dest mismatch.\n");
  94
  95                 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
  96                         NIPQUAD(ip->saddr),
  97                         NIPQUAD(ipinfo->smsk.s_addr),
  98                         NIPQUAD(ipinfo->src.s_addr),
  99                         ipinfo->invflags & IPT_INV_SRCIP ? " (INV)" : "");
 100                 dprintf("DST: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
 101                         NIPQUAD(ip->daddr),
 102                         NIPQUAD(ipinfo->dmsk.s_addr),
 103                         NIPQUAD(ipinfo->dst.s_addr),
 104                         ipinfo->invflags & IPT_INV_DSTIP ? " (INV)" : "");
 105                 return 0;
 106         }
 107
 108         /* Look for ifname matches; this should unroll nicely. */
 109         for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
 110                 ret |= (((const unsigned long *)indev)[i]
 111                         ^ ((const unsigned long *)ipinfo->iniface)[i])
 112                         & ((const unsigned long *)ipinfo->iniface_mask)[i];
 113         }
 114
 115         if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
 116                 dprintf("VIA in mismatch (%s vs %s).%s\n",
 117                         indev, ipinfo->iniface,
 118                         ipinfo->invflags&IPT_INV_VIA_IN ?" (INV)":"");
 119                 return 0;
 120         }
 121
 122         for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
 123                 ret |= (((const unsigned long *)outdev)[i]
 124                         ^ ((const unsigned long *)ipinfo->outiface)[i])
 125                         & ((const unsigned long *)ipinfo->outiface_mask)[i];
 126         }
 127
 128         if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
 129                 dprintf("VIA out mismatch (%s vs %s).%s\n",
 130                         outdev, ipinfo->outiface,
 131                         ipinfo->invflags&IPT_INV_VIA_OUT ?" (INV)":"");
 132                 return 0;
 133         }
 134
 135         /* Check specific protocol */
 136         if (ipinfo->proto
 137             && FWINV(ip->protocol != ipinfo->proto, IPT_INV_PROTO)) {
 138                 dprintf("Packet protocol %hi does not match %hi.%s\n",
 139                         ip->protocol, ipinfo->proto,
 140                         ipinfo->invflags&IPT_INV_PROTO ? " (INV)":"");
 141                 return 0;
 142         }
 143
 144         /* If we have a fragment rule but the packet is not a fragment
 145          * then we return zero */
 146         if (FWINV((ipinfo->flags&IPT_F_FRAG) && !isfrag, IPT_INV_FRAG)) {
 147                 dprintf("Fragment rule but not fragment.%s\n",
 148                         ipinfo->invflags & IPT_INV_FRAG ? " (INV)" : "");
 149                 return 0;
 150         }
 151
 152         return 1;
 153 }
 154
 155 static inline bool
 156 ip_checkentry(const struct ipt_ip *ip)
 157 {
 158         if (ip->flags & ~IPT_F_MASK) {
 159                 duprintf("Unknown flag bits set: %08X\n",
 160                          ip->flags & ~IPT_F_MASK);
 161                 return false;
 162         }
 163         if (ip->invflags & ~IPT_INV_MASK) {
 164                 duprintf("Unknown invflag bits set: %08X\n",
 165                          ip->invflags & ~IPT_INV_MASK);
 166                 return false;
 167         }
 168         return true;
 169 }
 170
 171 static unsigned int
 172 ipt_error(struct sk_buff *skb,
 173           const struct net_device *in,
 174           const struct net_device *out,
 175           unsigned int hooknum,
 176           const struct xt_target *target,
 177           const void *targinfo)
 178 {
 179         if (net_ratelimit())
 180                 printk("ip_tables: error: `%s'\n", (char *)targinfo);
 181
 182         return NF_DROP;
 183 }
 184
 185 static inline
 186 bool do_match(struct ipt_entry_match *m,
 187               const struct sk_buff *skb,
 188               const struct net_device *in,
 189               const struct net_device *out,
 190               int offset,
 191               bool *hotdrop)
 192 {
 193         /* Stop iteration if it doesn't match */
 194         if (!m->u.kernel.match->match(skb, in, out, m->u.kernel.match, m->data,
 195                                       offset, ip_hdrlen(skb), hotdrop))
 196                 return true;
 197         else
 198                 return false;
 199 }
 200
 201 static inline struct ipt_entry *
 202 get_entry(void *base, unsigned int offset)
 203 {
 204         return (struct ipt_entry *)(base + offset);
 205 }
 206
 207 /* All zeroes == unconditional rule. */
 208 static inline int
 209 unconditional(const struct ipt_ip *ip)
 210 {
 211         unsigned int i;
 212
 213         for (i = 0; i < sizeof(*ip)/sizeof(__u32); i++)
 214                 if (((__u32 *)ip)[i])
 215                         return 0;
 216
 217         return 1;
 218 }
 219
 220 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
 221     defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
 222 static const char *hooknames[] = {
 223         [NF_INET_PRE_ROUTING]           = "PREROUTING",
 224         [NF_INET_LOCAL_IN]              = "INPUT",
 225         [NF_INET_FORWARD]                       = "FORWARD",
 226         [NF_INET_LOCAL_OUT]             = "OUTPUT",
 227         [NF_INET_POST_ROUTING]          = "POSTROUTING",
 228 };
 229
 230 enum nf_ip_trace_comments {
 231         NF_IP_TRACE_COMMENT_RULE,
 232         NF_IP_TRACE_COMMENT_RETURN,
 233         NF_IP_TRACE_COMMENT_POLICY,
 234 };
 235
 236 static const char *comments[] = {
 237         [NF_IP_TRACE_COMMENT_RULE]      = "rule",
 238         [NF_IP_TRACE_COMMENT_RETURN]    = "return",
 239         [NF_IP_TRACE_COMMENT_POLICY]    = "policy",
 240 };
 241
 242 static struct nf_loginfo trace_loginfo = {
 243         .type = NF_LOG_TYPE_LOG,
 244         .u = {
 245                 .log = {
 246                         .level = 4,
 247                         .logflags = NF_LOG_MASK,
 248                 },
 249         },
 250 };
 251
 252 static inline int
 253 get_chainname_rulenum(struct ipt_entry *s, struct ipt_entry *e,
 254                       char *hookname, char **chainname,
 255                       char **comment, unsigned int *rulenum)
 256 {
 257         struct ipt_standard_target *t = (void *)ipt_get_target(s);
 258
 259         if (strcmp(t->target.u.kernel.target->name, IPT_ERROR_TARGET) == 0) {
 260                 /* Head of user chain: ERROR target with chainname */
 261                 *chainname = t->target.data;
 262                 (*rulenum) = 0;
 263         } else if (s == e) {
 264                 (*rulenum)++;
 265
 266                 if (s->target_offset == sizeof(struct ipt_entry)
 267                    && strcmp(t->target.u.kernel.target->name,
 268                              IPT_STANDARD_TARGET) == 0
 269                    && t->verdict < 0
 270                    && unconditional(&s->ip)) {
 271                         /* Tail of chains: STANDARD target (return/policy) */
 272                         *comment = *chainname == hookname
 273                                 ? (char *)comments[NF_IP_TRACE_COMMENT_POLICY]
 274                                 : (char *)comments[NF_IP_TRACE_COMMENT_RETURN];
 275                 }
 276                 return 1;
 277         } else
 278                 (*rulenum)++;
 279
 280         return 0;
 281 }
 282
 283 static void trace_packet(struct sk_buff *skb,
 284                          unsigned int hook,
 285                          const struct net_device *in,
 286                          const struct net_device *out,
 287                          char *tablename,
 288                          struct xt_table_info *private,
 289                          struct ipt_entry *e)
 290 {
 291         void *table_base;
 292         struct ipt_entry *root;
 293         char *hookname, *chainname, *comment;
 294         unsigned int rulenum = 0;
 295
 296         table_base = (void *)private->entries[smp_processor_id()];
 297         root = get_entry(table_base, private->hook_entry[hook]);
 298
 299         hookname = chainname = (char *)hooknames[hook];
 300         comment = (char *)comments[NF_IP_TRACE_COMMENT_RULE];
 301
 302         IPT_ENTRY_ITERATE(root,
 303                           private->size - private->hook_entry[hook],
 304                           get_chainname_rulenum,
 305                           e, hookname, &chainname, &comment, &rulenum);
 306
 307         nf_log_packet(AF_INET, hook, skb, in, out, &trace_loginfo,
 308                       "TRACE: %s:%s:%s:%u ",
 309                       tablename, chainname, comment, rulenum);
 310 }
 311 #endif
 312
 313 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
 314 unsigned int
 315 ipt_do_table(struct sk_buff *skb,
 316              unsigned int hook,
 317              const struct net_device *in,
 318              const struct net_device *out,
 319              struct xt_table *table)
 320 {
 321         static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
 322         u_int16_t offset;
 323         struct iphdr *ip;
 324         u_int16_t datalen;
 325         bool hotdrop = false;
 326         /* Initializing verdict to NF_DROP keeps gcc happy. */
 327         unsigned int verdict = NF_DROP;
 328         const char *indev, *outdev;
 329         void *table_base;
 330         struct ipt_entry *e, *back;
 331         struct xt_table_info *private;
 332
 333         /* Initialization */
 334         ip = ip_hdr(skb);
 335         datalen = skb->len - ip->ihl * 4;
 336         indev = in ? in->name : nulldevname;
 337         outdev = out ? out->name : nulldevname;
 338         /* We handle fragments by dealing with the first fragment as
 339          * if it was a normal packet.  All other fragments are treated
 340          * normally, except that they will NEVER match rules that ask
 341          * things we don't know, ie. tcp syn flag or ports).  If the
 342          * rule is also a fragment-specific rule, non-fragments won't
 343          * match it. */
 344         offset = ntohs(ip->frag_off) & IP_OFFSET;
 345
 346         read_lock_bh(&table->lock);
 347         IP_NF_ASSERT(table->valid_hooks & (1 << hook));
 348         private = table->private;
 349         table_base = (void *)private->entries[smp_processor_id()];
 350         e = get_entry(table_base, private->hook_entry[hook]);
 351
 352         /* For return from builtin chain */
 353         back = get_entry(table_base, private->underflow[hook]);
 354
 355         do {
 356                 IP_NF_ASSERT(e);
 357                 IP_NF_ASSERT(back);
 358                 if (ip_packet_match(ip, indev, outdev, &e->ip, offset)) {
 359                         struct ipt_entry_target *t;
 360
 361                         if (IPT_MATCH_ITERATE(e, do_match,
 362                                               skb, in, out,
 363                                               offset, &hotdrop) != 0)
 364                                 goto no_match;
 365
 366                         ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1);
 367
 368                         t = ipt_get_target(e);
 369                         IP_NF_ASSERT(t->u.kernel.target);
 370
 371 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
 372     defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
 373                         /* The packet is traced: log it */
 374                         if (unlikely(skb->nf_trace))
 375                                 trace_packet(skb, hook, in, out,
 376                                              table->name, private, e);
 377 #endif
 378                         /* Standard target? */
 379                         if (!t->u.kernel.target->target) {
 380                                 int v;
 381
 382                                 v = ((struct ipt_standard_target *)t)->verdict;
 383                                 if (v < 0) {
 384                                         /* Pop from stack? */
 385                                         if (v != IPT_RETURN) {
 386                                                 verdict = (unsigned)(-v) - 1;
 387                                                 break;
 388                                         }
 389                                         e = back;
 390                                         back = get_entry(table_base,
 391                                                          back->comefrom);
 392                                         continue;
 393                                 }
 394                                 if (table_base + v != (void *)e + e->next_offset
 395                                     && !(e->ip.flags & IPT_F_GOTO)) {
 396                                         /* Save old back ptr in next entry */
 397                                         struct ipt_entry *next
 398                                                 = (void *)e + e->next_offset;
 399                                         next->comefrom
 400                                                 = (void *)back - table_base;
 401                                         /* set back pointer to next entry */
 402                                         back = next;
 403                                 }
 404
 405                                 e = get_entry(table_base, v);
 406                         } else {
 407                                 /* Targets which reenter must return
 408                                    abs. verdicts */
 409 #ifdef CONFIG_NETFILTER_DEBUG
 410                                 ((struct ipt_entry *)table_base)->comefrom
 411                                         = 0xeeeeeeec;
 412 #endif
 413                                 verdict = t->u.kernel.target->target(skb,
 414                                                                      in, out,
 415                                                                      hook,
 416                                                                      t->u.kernel.target,
 417                                                                      t->data);
 418
 419 #ifdef CONFIG_NETFILTER_DEBUG
 420                                 if (((struct ipt_entry *)table_base)->comefrom
 421                                     != 0xeeeeeeec
 422                                     && verdict == IPT_CONTINUE) {
 423                                         printk("Target %s reentered!\n",
 424                                                t->u.kernel.target->name);
 425                                         verdict = NF_DROP;
 426                                 }
 427                                 ((struct ipt_entry *)table_base)->comefrom
 428                                         = 0x57acc001;
 429 #endif
 430                                 /* Target might have changed stuff. */
 431                                 ip = ip_hdr(skb);
 432                                 datalen = skb->len - ip->ihl * 4;
 433
 434                                 if (verdict == IPT_CONTINUE)
 435                                         e = (void *)e + e->next_offset;
 436                                 else
 437                                         /* Verdict */
 438                                         break;
 439                         }
 440                 } else {
 441
 442                 no_match:
 443                         e = (void *)e + e->next_offset;
 444                 }
 445         } while (!hotdrop);
 446
 447         read_unlock_bh(&table->lock);
 448
 449 #ifdef DEBUG_ALLOW_ALL
 450         return NF_ACCEPT;
 451 #else
 452         if (hotdrop)
 453                 return NF_DROP;
 454         else return verdict;
 455 #endif
 456 }
 457
 458 /* Figures out from what hook each rule can be called: returns 0 if
 459    there are loops.  Puts hook bitmask in comefrom. */
 460 static int
 461 mark_source_chains(struct xt_table_info *newinfo,
 462                    unsigned int valid_hooks, void *entry0)
 463 {
 464         unsigned int hook;
 465
 466         /* No recursion; use packet counter to save back ptrs (reset
 467            to 0 as we leave), and comefrom to save source hook bitmask */
 468         for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
 469                 unsigned int pos = newinfo->hook_entry[hook];
 470                 struct ipt_entry *e
 471                         = (struct ipt_entry *)(entry0 + pos);
 472
 473                 if (!(valid_hooks & (1 << hook)))
 474                         continue;
 475
 476                 /* Set initial back pointer. */
 477                 e->counters.pcnt = pos;
 478
 479                 for (;;) {
 480                         struct ipt_standard_target *t
 481                                 = (void *)ipt_get_target(e);
 482                         int visited = e->comefrom & (1 << hook);
 483
 484                         if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
 485                                 printk("iptables: loop hook %u pos %u %08X.\n",
 486                                        hook, pos, e->comefrom);
 487                                 return 0;
 488                         }
 489                         e->comefrom
 490                                 |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
 491
 492                         /* Unconditional return/END. */
 493                         if ((e->target_offset == sizeof(struct ipt_entry)
 494                             && (strcmp(t->target.u.user.name,
 495                                        IPT_STANDARD_TARGET) == 0)
 496                             && t->verdict < 0
 497                             && unconditional(&e->ip)) || visited) {
 498                                 unsigned int oldpos, size;
 499
 500                                 if (t->verdict < -NF_MAX_VERDICT - 1) {
 501                                         duprintf("mark_source_chains: bad "
 502                                                 "negative verdict (%i)\n",
 503                                                                 t->verdict);
 504                                         return 0;
 505                                 }
 506
 507                                 /* Return: backtrack through the last
 508                                    big jump. */
 509                                 do {
 510                                         e->comefrom ^= (1<<NF_INET_NUMHOOKS);
 511 #ifdef DEBUG_IP_FIREWALL_USER
 512                                         if (e->comefrom
 513                                             & (1 << NF_INET_NUMHOOKS)) {
 514                                                 duprintf("Back unset "
 515                                                          "on hook %u "
 516                                                          "rule %u\n",
 517                                                          hook, pos);
 518                                         }
 519 #endif
 520                                         oldpos = pos;
 521                                         pos = e->counters.pcnt;
 522                                         e->counters.pcnt = 0;
 523
 524                                         /* We're at the start. */
 525                                         if (pos == oldpos)
 526                                                 goto next;
 527
 528                                         e = (struct ipt_entry *)
 529                                                 (entry0 + pos);
 530                                 } while (oldpos == pos + e->next_offset);
 531
 532                                 /* Move along one */
 533                                 size = e->next_offset;
 534                                 e = (struct ipt_entry *)
 535                                         (entry0 + pos + size);
 536                                 e->counters.pcnt = pos;
 537                                 pos += size;
 538                         } else {
 539                                 int newpos = t->verdict;
 540
 541                                 if (strcmp(t->target.u.user.name,
 542                                            IPT_STANDARD_TARGET) == 0
 543                                     && newpos >= 0) {
 544                                         if (newpos > newinfo->size -
 545                                                 sizeof(struct ipt_entry)) {
 546                                                 duprintf("mark_source_chains: "
 547                                                         "bad verdict (%i)\n",
 548                                                                 newpos);
 549                                                 return 0;
 550                                         }
 551                                         /* This a jump; chase it. */
 552                                         duprintf("Jump rule %u -> %u\n",
 553                                                  pos, newpos);
 554                                 } else {
 555                                         /* ... this is a fallthru */
 556                                         newpos = pos + e->next_offset;
 557                                 }
 558                                 e = (struct ipt_entry *)
 559                                         (entry0 + newpos);
 560                                 e->counters.pcnt = pos;
 561                                 pos = newpos;
 562                         }
 563                 }
 564                 next:
 565                 duprintf("Finished chain %u\n", hook);
 566         }
 567         return 1;
 568 }
 569
 570 static inline int
 571 cleanup_match(struct ipt_entry_match *m, unsigned int *i)
 572 {
 573         if (i && (*i)-- == 0)
 574                 return 1;
 575
 576         if (m->u.kernel.match->destroy)
 577                 m->u.kernel.match->destroy(m->u.kernel.match, m->data);
 578         module_put(m->u.kernel.match->me);
 579         return 0;
 580 }
 581
 582 static inline int
 583 check_entry(struct ipt_entry *e, const char *name)
 584 {
 585         struct ipt_entry_target *t;
 586
 587         if (!ip_checkentry(&e->ip)) {
 588                 duprintf("ip_tables: ip check failed %p %s.\n", e, name);
 589                 return -EINVAL;
 590         }
 591
 592         if (e->target_offset + sizeof(struct ipt_entry_target) > e->next_offset)
 593                 return -EINVAL;
 594
 595         t = ipt_get_target(e);
 596         if (e->target_offset + t->u.target_size > e->next_offset)
 597                 return -EINVAL;
 598
 599         return 0;
 600 }
 601
 602 static inline int check_match(struct ipt_entry_match *m, const char *name,
 603                               const struct ipt_ip *ip,
 604                               unsigned int hookmask, unsigned int *i)
 605 {
 606         struct xt_match *match;
 607         int ret;
 608
 609         match = m->u.kernel.match;
 610         ret = xt_check_match(match, AF_INET, m->u.match_size - sizeof(*m),
 611                              name, hookmask, ip->proto,
 612                              ip->invflags & IPT_INV_PROTO);
 613         if (!ret && m->u.kernel.match->checkentry
 614             && !m->u.kernel.match->checkentry(name, ip, match, m->data,
 615                                               hookmask)) {
 616                 duprintf("ip_tables: check failed for `%s'.\n",
 617                          m->u.kernel.match->name);
 618                 ret = -EINVAL;
 619         }
 620         if (!ret)
 621                 (*i)++;
 622         return ret;
 623 }
 624
 625 static inline int
 626 find_check_match(struct ipt_entry_match *m,
 627                  const char *name,
 628                  const struct ipt_ip *ip,
 629                  unsigned int hookmask,
 630                  unsigned int *i)
 631 {
 632         struct xt_match *match;
 633         int ret;
 634
 635         match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
 636                                                    m->u.user.revision),
 637                                         "ipt_%s", m->u.user.name);
 638         if (IS_ERR(match) || !match) {
 639                 duprintf("find_check_match: `%s' not found\n", m->u.user.name);
 640                 return match ? PTR_ERR(match) : -ENOENT;
 641         }
 642         m->u.kernel.match = match;
 643
 644         ret = check_match(m, name, ip, hookmask, i);
 645         if (ret)
 646                 goto err;
 647
 648         return 0;
 649 err:
 650         module_put(m->u.kernel.match->me);
 651         return ret;
 652 }
 653
 654 static inline int check_target(struct ipt_entry *e, const char *name)
 655 {
 656         struct ipt_entry_target *t;
 657         struct xt_target *target;
 658         int ret;
 659
 660         t = ipt_get_target(e);
 661         target = t->u.kernel.target;
 662         ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
 663                               name, e->comefrom, e->ip.proto,
 664                               e->ip.invflags & IPT_INV_PROTO);
 665         if (!ret && t->u.kernel.target->checkentry
 666             && !t->u.kernel.target->checkentry(name, e, target, t->data,
 667                                                e->comefrom)) {
 668                 duprintf("ip_tables: check failed for `%s'.\n",
 669                          t->u.kernel.target->name);
 670                 ret = -EINVAL;
 671         }
 672         return ret;
 673 }
 674
 675 static inline int
 676 find_check_entry(struct ipt_entry *e, const char *name, unsigned int size,
 677                  unsigned int *i)
 678 {
 679         struct ipt_entry_target *t;
 680         struct xt_target *target;
 681         int ret;
 682         unsigned int j;
 683
 684         ret = check_entry(e, name);
 685         if (ret)
 686                 return ret;
 687
 688         j = 0;
 689         ret = IPT_MATCH_ITERATE(e, find_check_match, name, &e->ip,
 690                                 e->comefrom, &j);
 691         if (ret != 0)
 692                 goto cleanup_matches;
 693
 694         t = ipt_get_target(e);
 695         target = try_then_request_module(xt_find_target(AF_INET,
 696                                                         t->u.user.name,
 697                                                         t->u.user.revision),
 698                                          "ipt_%s", t->u.user.name);
 699         if (IS_ERR(target) || !target) {
 700                 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
 701                 ret = target ? PTR_ERR(target) : -ENOENT;
 702                 goto cleanup_matches;
 703         }
 704         t->u.kernel.target = target;
 705
 706         ret = check_target(e, name);
 707         if (ret)
 708                 goto err;
 709
 710         (*i)++;
 711         return 0;
 712  err:
 713         module_put(t->u.kernel.target->me);
 714  cleanup_matches:
 715         IPT_MATCH_ITERATE(e, cleanup_match, &j);
 716         return ret;
 717 }
 718
 719 static inline int
 720 check_entry_size_and_hooks(struct ipt_entry *e,
 721                            struct xt_table_info *newinfo,
 722                            unsigned char *base,
 723                            unsigned char *limit,
 724                            const unsigned int *hook_entries,
 725                            const unsigned int *underflows,
 726                            unsigned int *i)
 727 {
 728         unsigned int h;
 729
 730         if ((unsigned long)e % __alignof__(struct ipt_entry) != 0
 731             || (unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
 732                 duprintf("Bad offset %p\n", e);
 733                 return -EINVAL;
 734         }
 735
 736         if (e->next_offset
 737             < sizeof(struct ipt_entry) + sizeof(struct ipt_entry_target)) {
 738                 duprintf("checking: element %p size %u\n",
 739                          e, e->next_offset);
 740                 return -EINVAL;
 741         }
 742
 743         /* Check hooks & underflows */
 744         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
 745                 if ((unsigned char *)e - base == hook_entries[h])
 746                         newinfo->hook_entry[h] = hook_entries[h];
 747                 if ((unsigned char *)e - base == underflows[h])
 748                         newinfo->underflow[h] = underflows[h];
 749         }
 750
 751         /* FIXME: underflows must be unconditional, standard verdicts
 752            < 0 (not IPT_RETURN). --RR */
 753
 754         /* Clear counters and comefrom */
 755         e->counters = ((struct xt_counters) { 0, 0 });
 756         e->comefrom = 0;
 757
 758         (*i)++;
 759         return 0;
 760 }
 761
 762 static inline int
 763 cleanup_entry(struct ipt_entry *e, unsigned int *i)
 764 {
 765         struct ipt_entry_target *t;
 766
 767         if (i && (*i)-- == 0)
 768                 return 1;
 769
 770         /* Cleanup all matches */
 771         IPT_MATCH_ITERATE(e, cleanup_match, NULL);
 772         t = ipt_get_target(e);
 773         if (t->u.kernel.target->destroy)
 774                 t->u.kernel.target->destroy(t->u.kernel.target, t->data);
 775         module_put(t->u.kernel.target->me);
 776         return 0;
 777 }
 778
 779 /* Checks and translates the user-supplied table segment (held in
 780    newinfo) */
 781 static int
 782 translate_table(const char *name,
 783                 unsigned int valid_hooks,
 784                 struct xt_table_info *newinfo,
 785                 void *entry0,
 786                 unsigned int size,
 787                 unsigned int number,
 788                 const unsigned int *hook_entries,
 789                 const unsigned int *underflows)
 790 {
 791         unsigned int i;
 792         int ret;
 793
 794         newinfo->size = size;
 795         newinfo->number = number;
 796
 797         /* Init all hooks to impossible value. */
 798         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 799                 newinfo->hook_entry[i] = 0xFFFFFFFF;
 800                 newinfo->underflow[i] = 0xFFFFFFFF;
 801         }
 802
 803         duprintf("translate_table: size %u\n", newinfo->size);
 804         i = 0;
 805         /* Walk through entries, checking offsets. */
 806         ret = IPT_ENTRY_ITERATE(entry0, newinfo->size,
 807                                 check_entry_size_and_hooks,
 808                                 newinfo,
 809                                 entry0,
 810                                 entry0 + size,
 811                                 hook_entries, underflows, &i);
 812         if (ret != 0)
 813                 return ret;
 814
 815         if (i != number) {
 816                 duprintf("translate_table: %u not %u entries\n",
 817                          i, number);
 818                 return -EINVAL;
 819         }
 820
 821         /* Check hooks all assigned */
 822         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
 823                 /* Only hooks which are valid */
 824                 if (!(valid_hooks & (1 << i)))
 825                         continue;
 826                 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
 827                         duprintf("Invalid hook entry %u %u\n",
 828                                  i, hook_entries[i]);
 829                         return -EINVAL;
 830                 }
 831                 if (newinfo->underflow[i] == 0xFFFFFFFF) {
 832                         duprintf("Invalid underflow %u %u\n",
 833                                  i, underflows[i]);
 834                         return -EINVAL;
 835                 }
 836         }
 837
 838         if (!mark_source_chains(newinfo, valid_hooks, entry0))
 839                 return -ELOOP;
 840
 841         /* Finally, each sanity check must pass */
 842         i = 0;
 843         ret = IPT_ENTRY_ITERATE(entry0, newinfo->size,
 844                                 find_check_entry, name, size, &i);
 845
 846         if (ret != 0) {
 847                 IPT_ENTRY_ITERATE(entry0, newinfo->size,
 848                                 cleanup_entry, &i);
 849                 return ret;
 850         }
 851
 852         /* And one copy for every other CPU */
 853         for_each_possible_cpu(i) {
 854                 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
 855                         memcpy(newinfo->entries[i], entry0, newinfo->size);
 856         }
 857
 858         return ret;
 859 }
 860
 861 /* Gets counters. */
 862 static inline int
 863 add_entry_to_counter(const struct ipt_entry *e,
 864                      struct xt_counters total[],
 865                      unsigned int *i)
 866 {
 867         ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
 868
 869         (*i)++;
 870         return 0;
 871 }
 872
 873 static inline int
 874 set_entry_to_counter(const struct ipt_entry *e,
 875                      struct ipt_counters total[],
 876                      unsigned int *i)
 877 {
 878         SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
 879
 880         (*i)++;
 881         return 0;
 882 }
 883
 884 static void
 885 get_counters(const struct xt_table_info *t,
 886              struct xt_counters counters[])
 887 {
 888         unsigned int cpu;
 889         unsigned int i;
 890         unsigned int curcpu;
 891
 892         /* Instead of clearing (by a previous call to memset())
 893          * the counters and using adds, we set the counters
 894          * with data used by 'current' CPU
 895          * We dont care about preemption here.
 896          */
 897         curcpu = raw_smp_processor_id();
 898
 899         i = 0;
 900         IPT_ENTRY_ITERATE(t->entries[curcpu],
 901                           t->size,
 902                           set_entry_to_counter,
 903                           counters,
 904                           &i);
 905
 906         for_each_possible_cpu(cpu) {
 907                 if (cpu == curcpu)
 908                         continue;
 909                 i = 0;
 910                 IPT_ENTRY_ITERATE(t->entries[cpu],
 911                                   t->size,
 912                                   add_entry_to_counter,
 913                                   counters,
 914                                   &i);
 915         }
 916 }
 917
 918 static inline struct xt_counters * alloc_counters(struct xt_table *table)
 919 {
 920         unsigned int countersize;
 921         struct xt_counters *counters;
 922         struct xt_table_info *private = table->private;
 923
 924         /* We need atomic snapshot of counters: rest doesn't change
 925            (other than comefrom, which userspace doesn't care
 926            about). */
 927         countersize = sizeof(struct xt_counters) * private->number;
 928         counters = vmalloc_node(countersize, numa_node_id());
 929
 930         if (counters == NULL)
 931                 return ERR_PTR(-ENOMEM);
 932
 933         /* First, sum counters... */
 934         write_lock_bh(&table->lock);
 935         get_counters(private, counters);
 936         write_unlock_bh(&table->lock);
 937
 938         return counters;
 939 }
 940
 941 static int
 942 copy_entries_to_user(unsigned int total_size,
 943                      struct xt_table *table,
 944                      void __user *userptr)
 945 {
 946         unsigned int off, num;
 947         struct ipt_entry *e;
 948         struct xt_counters *counters;
 949         struct xt_table_info *private = table->private;
 950         int ret = 0;
 951         void *loc_cpu_entry;
 952
 953         counters = alloc_counters(table);
 954         if (IS_ERR(counters))
 955                 return PTR_ERR(counters);
 956
 957         /* choose the copy that is on our node/cpu, ...
 958          * This choice is lazy (because current thread is
 959          * allowed to migrate to another cpu)
 960          */
 961         loc_cpu_entry = private->entries[raw_smp_processor_id()];
 962         /* ... then copy entire thing ... */
 963         if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
 964                 ret = -EFAULT;
 965                 goto free_counters;
 966         }
 967
 968         /* FIXME: use iterator macros --RR */
 969         /* ... then go back and fix counters and names */
 970         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
 971                 unsigned int i;
 972                 struct ipt_entry_match *m;
 973                 struct ipt_entry_target *t;
 974
 975                 e = (struct ipt_entry *)(loc_cpu_entry + off);
 976                 if (copy_to_user(userptr + off
 977                                  + offsetof(struct ipt_entry, counters),
 978                                  &counters[num],
 979                                  sizeof(counters[num])) != 0) {
 980                         ret = -EFAULT;
 981                         goto free_counters;
 982                 }
 983
 984                 for (i = sizeof(struct ipt_entry);
 985                      i < e->target_offset;
 986                      i += m->u.match_size) {
 987                         m = (void *)e + i;
 988
 989                         if (copy_to_user(userptr + off + i
 990                                          + offsetof(struct ipt_entry_match,
 991                                                     u.user.name),
 992                                          m->u.kernel.match->name,
 993                                          strlen(m->u.kernel.match->name)+1)
 994                             != 0) {
 995                                 ret = -EFAULT;
 996                                 goto free_counters;
 997                         }
 998                 }
 999
1000                 t = ipt_get_target(e);
1001                 if (copy_to_user(userptr + off + e->target_offset
1002                                  + offsetof(struct ipt_entry_target,
1003                                             u.user.name),
1004                                  t->u.kernel.target->name,
1005                                  strlen(t->u.kernel.target->name)+1) != 0) {
1006                         ret = -EFAULT;
1007                         goto free_counters;
1008                 }
1009         }
1010
1011  free_counters:
1012         vfree(counters);
1013         return ret;
1014 }
1015
1016 #ifdef CONFIG_COMPAT
1017 struct compat_delta {
1018         struct compat_delta *next;
1019         unsigned int offset;
1020         short delta;
1021 };
1022
1023 static struct compat_delta *compat_offsets;
1024
1025 static int compat_add_offset(unsigned int offset, short delta)
1026 {
1027         struct compat_delta *tmp;
1028
1029         tmp = kmalloc(sizeof(struct compat_delta), GFP_KERNEL);
1030         if (!tmp)
1031                 return -ENOMEM;
1032         tmp->offset = offset;
1033         tmp->delta = delta;
1034         if (compat_offsets) {
1035                 tmp->next = compat_offsets->next;
1036                 compat_offsets->next = tmp;
1037         } else {
1038                 compat_offsets = tmp;
1039                 tmp->next = NULL;
1040         }
1041         return 0;
1042 }
1043
1044 static void compat_flush_offsets(void)
1045 {
1046         struct compat_delta *tmp, *next;
1047
1048         if (compat_offsets) {
1049                 for (tmp = compat_offsets; tmp; tmp = next) {
1050                         next = tmp->next;
1051                         kfree(tmp);
1052                 }
1053                 compat_offsets = NULL;
1054         }
1055 }
1056
1057 static short compat_calc_jump(unsigned int offset)
1058 {
1059         struct compat_delta *tmp;
1060         short delta;
1061
1062         for (tmp = compat_offsets, delta = 0; tmp; tmp = tmp->next)
1063                 if (tmp->offset < offset)
1064                         delta += tmp->delta;
1065         return delta;
1066 }
1067
1068 static void compat_standard_from_user(void *dst, void *src)
1069 {
1070         int v = *(compat_int_t *)src;
1071
1072         if (v > 0)
1073                 v += compat_calc_jump(v);
1074         memcpy(dst, &v, sizeof(v));
1075 }
1076
1077 static int compat_standard_to_user(void __user *dst, void *src)
1078 {
1079         compat_int_t cv = *(int *)src;
1080
1081         if (cv > 0)
1082                 cv -= compat_calc_jump(cv);
1083         return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
1084 }
1085
1086 static inline int
1087 compat_calc_match(struct ipt_entry_match *m, int *size)
1088 {
1089         *size += xt_compat_match_offset(m->u.kernel.match);
1090         return 0;
1091 }
1092
1093 static int compat_calc_entry(struct ipt_entry *e,
1094                              const struct xt_table_info *info,
1095                              void *base, struct xt_table_info *newinfo)
1096 {
1097         struct ipt_entry_target *t;
1098         unsigned int entry_offset;
1099         int off, i, ret;
1100
1101         off = 0;
1102         entry_offset = (void *)e - base;
1103         IPT_MATCH_ITERATE(e, compat_calc_match, &off);
1104         t = ipt_get_target(e);
1105         off += xt_compat_target_offset(t->u.kernel.target);
1106         newinfo->size -= off;
1107         ret = compat_add_offset(entry_offset, off);
1108         if (ret)
1109                 return ret;
1110
1111         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1112                 if (info->hook_entry[i] &&
1113                     (e < (struct ipt_entry *)(base + info->hook_entry[i])))
1114                         newinfo->hook_entry[i] -= off;
1115                 if (info->underflow[i] &&
1116                     (e < (struct ipt_entry *)(base + info->underflow[i])))
1117                         newinfo->underflow[i] -= off;
1118         }
1119         return 0;
1120 }
1121
1122 static int compat_table_info(const struct xt_table_info *info,
1123                              struct xt_table_info *newinfo)
1124 {
1125         void *loc_cpu_entry;
1126
1127         if (!newinfo || !info)
1128                 return -EINVAL;
1129
1130         /* we dont care about newinfo->entries[] */
1131         memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
1132         newinfo->initial_entries = 0;
1133         loc_cpu_entry = info->entries[raw_smp_processor_id()];
1134         return IPT_ENTRY_ITERATE(loc_cpu_entry, info->size,
1135                                  compat_calc_entry, info, loc_cpu_entry,
1136                                  newinfo);
1137 }
1138 #endif
1139
1140 static int get_info(void __user *user, int *len, int compat)
1141 {
1142         char name[IPT_TABLE_MAXNAMELEN];
1143         struct xt_table *t;
1144         int ret;
1145
1146         if (*len != sizeof(struct ipt_getinfo)) {
1147                 duprintf("length %u != %u\n", *len,
1148                         (unsigned int)sizeof(struct ipt_getinfo));
1149                 return -EINVAL;
1150         }
1151
1152         if (copy_from_user(name, user, sizeof(name)) != 0)
1153                 return -EFAULT;
1154
1155         name[IPT_TABLE_MAXNAMELEN-1] = '\0';
1156 #ifdef CONFIG_COMPAT
1157         if (compat)
1158                 xt_compat_lock(AF_INET);
1159 #endif
1160         t = try_then_request_module(xt_find_table_lock(AF_INET, name),
1161                                     "iptable_%s", name);
1162         if (t && !IS_ERR(t)) {
1163                 struct ipt_getinfo info;
1164                 struct xt_table_info *private = t->private;
1165
1166 #ifdef CONFIG_COMPAT
1167                 if (compat) {
1168                         struct xt_table_info tmp;
1169                         ret = compat_table_info(private, &tmp);
1170                         compat_flush_offsets();
1171                         private = &tmp;
1172                 }
1173 #endif
1174                 info.valid_hooks = t->valid_hooks;
1175                 memcpy(info.hook_entry, private->hook_entry,
1176                        sizeof(info.hook_entry));
1177                 memcpy(info.underflow, private->underflow,
1178                        sizeof(info.underflow));
1179                 info.num_entries = private->number;
1180                 info.size = private->size;
1181                 strcpy(info.name, name);
1182
1183                 if (copy_to_user(user, &info, *len) != 0)
1184                         ret = -EFAULT;
1185                 else
1186                         ret = 0;
1187
1188                 xt_table_unlock(t);
1189                 module_put(t->me);
1190         } else
1191                 ret = t ? PTR_ERR(t) : -ENOENT;
1192 #ifdef CONFIG_COMPAT
1193         if (compat)
1194                 xt_compat_unlock(AF_INET);
1195 #endif
1196         return ret;
1197 }
1198
1199 static int
1200 get_entries(struct ipt_get_entries __user *uptr, int *len)
1201 {
1202         int ret;
1203         struct ipt_get_entries get;
1204         struct xt_table *t;
1205
1206         if (*len < sizeof(get)) {
1207                 duprintf("get_entries: %u < %d\n", *len,
1208                                 (unsigned int)sizeof(get));
1209                 return -EINVAL;
1210         }
1211         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1212                 return -EFAULT;
1213         if (*len != sizeof(struct ipt_get_entries) + get.size) {
1214                 duprintf("get_entries: %u != %u\n", *len,
1215                                 (unsigned int)(sizeof(struct ipt_get_entries) +
1216                                 get.size));
1217                 return -EINVAL;
1218         }
1219
1220         t = xt_find_table_lock(AF_INET, get.name);
1221         if (t && !IS_ERR(t)) {
1222                 struct xt_table_info *private = t->private;
1223                 duprintf("t->private->number = %u\n",
1224                          private->number);
1225                 if (get.size == private->size)
1226                         ret = copy_entries_to_user(private->size,
1227                                                    t, uptr->entrytable);
1228                 else {
1229                         duprintf("get_entries: I've got %u not %u!\n",
1230                                  private->size,
1231                                  get.size);
1232                         ret = -EINVAL;
1233                 }
1234                 module_put(t->me);
1235                 xt_table_unlock(t);
1236         } else
1237                 ret = t ? PTR_ERR(t) : -ENOENT;
1238
1239         return ret;
1240 }
1241
1242 static int
1243 __do_replace(const char *name, unsigned int valid_hooks,
1244              struct xt_table_info *newinfo, unsigned int num_counters,
1245              void __user *counters_ptr)
1246 {
1247         int ret;
1248         struct xt_table *t;
1249         struct xt_table_info *oldinfo;
1250         struct xt_counters *counters;
1251         void *loc_cpu_old_entry;
1252
1253         ret = 0;
1254         counters = vmalloc(num_counters * sizeof(struct xt_counters));
1255         if (!counters) {
1256                 ret = -ENOMEM;
1257                 goto out;
1258         }
1259
1260         t = try_then_request_module(xt_find_table_lock(AF_INET, name),
1261                                     "iptable_%s", name);
1262         if (!t || IS_ERR(t)) {
1263                 ret = t ? PTR_ERR(t) : -ENOENT;
1264                 goto free_newinfo_counters_untrans;
1265         }
1266
1267         /* You lied! */
1268         if (valid_hooks != t->valid_hooks) {
1269                 duprintf("Valid hook crap: %08X vs %08X\n",
1270                          valid_hooks, t->valid_hooks);
1271                 ret = -EINVAL;
1272                 goto put_module;
1273         }
1274
1275         oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1276         if (!oldinfo)
1277                 goto put_module;
1278
1279         /* Update module usage count based on number of rules */
1280         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1281                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1282         if ((oldinfo->number > oldinfo->initial_entries) ||
1283             (newinfo->number <= oldinfo->initial_entries))
1284                 module_put(t->me);
1285         if ((oldinfo->number > oldinfo->initial_entries) &&
1286             (newinfo->number <= oldinfo->initial_entries))
1287                 module_put(t->me);
1288
1289         /* Get the old counters. */
1290         get_counters(oldinfo, counters);
1291         /* Decrease module usage counts and free resource */
1292         loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1293         IPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,
1294                           NULL);
1295         xt_free_table_info(oldinfo);
1296         if (copy_to_user(counters_ptr, counters,
1297                          sizeof(struct xt_counters) * num_counters) != 0)
1298                 ret = -EFAULT;
1299         vfree(counters);
1300         xt_table_unlock(t);
1301         return ret;
1302
1303  put_module:
1304         module_put(t->me);
1305         xt_table_unlock(t);
1306  free_newinfo_counters_untrans:
1307         vfree(counters);
1308  out:
1309         return ret;
1310 }
1311
1312 static int
1313 do_replace(void __user *user, unsigned int len)
1314 {
1315         int ret;
1316         struct ipt_replace tmp;
1317         struct xt_table_info *newinfo;
1318         void *loc_cpu_entry;
1319
1320         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1321                 return -EFAULT;
1322
1323         /* Hack: Causes ipchains to give correct error msg --RR */
1324         if (len != sizeof(tmp) + tmp.size)
1325                 return -ENOPROTOOPT;
1326
1327         /* overflow check */
1328         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1329                 return -ENOMEM;
1330
1331         newinfo = xt_alloc_table_info(tmp.size);
1332         if (!newinfo)
1333                 return -ENOMEM;
1334
1335         /* choose the copy that is our node/cpu */
1336         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1337         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1338                            tmp.size) != 0) {
1339                 ret = -EFAULT;
1340                 goto free_newinfo;
1341         }
1342
1343         ret = translate_table(tmp.name, tmp.valid_hooks,
1344                               newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
1345                               tmp.hook_entry, tmp.underflow);
1346         if (ret != 0)
1347                 goto free_newinfo;
1348
1349         duprintf("ip_tables: Translated table\n");
1350
1351         ret = __do_replace(tmp.name, tmp.valid_hooks, newinfo,
1352                            tmp.num_counters, tmp.counters);
1353         if (ret)
1354                 goto free_newinfo_untrans;
1355         return 0;
1356
1357  free_newinfo_untrans:
1358         IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
1359  free_newinfo:
1360         xt_free_table_info(newinfo);
1361         return ret;
1362 }
1363
1364 /* We're lazy, and add to the first CPU; overflow works its fey magic
1365  * and everything is OK. */
1366 static inline int
1367 add_counter_to_entry(struct ipt_entry *e,
1368                      const struct xt_counters addme[],
1369                      unsigned int *i)
1370 {
1371 #if 0
1372         duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n",
1373                  *i,
1374                  (long unsigned int)e->counters.pcnt,
1375                  (long unsigned int)e->counters.bcnt,
1376                  (long unsigned int)addme[*i].pcnt,
1377                  (long unsigned int)addme[*i].bcnt);
1378 #endif
1379
1380         ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
1381
1382         (*i)++;
1383         return 0;
1384 }
1385
1386 static int
1387 do_add_counters(void __user *user, unsigned int len, int compat)
1388 {
1389         unsigned int i;
1390         struct xt_counters_info tmp;
1391         struct xt_counters *paddc;
1392         unsigned int num_counters;
1393         char *name;
1394         int size;
1395         void *ptmp;
1396         struct xt_table *t;
1397         struct xt_table_info *private;
1398         int ret = 0;
1399         void *loc_cpu_entry;
1400 #ifdef CONFIG_COMPAT
1401         struct compat_xt_counters_info compat_tmp;
1402
1403         if (compat) {
1404                 ptmp = &compat_tmp;
1405                 size = sizeof(struct compat_xt_counters_info);
1406         } else
1407 #endif
1408         {
1409                 ptmp = &tmp;
1410                 size = sizeof(struct xt_counters_info);
1411         }
1412
1413         if (copy_from_user(ptmp, user, size) != 0)
1414                 return -EFAULT;
1415
1416 #ifdef CONFIG_COMPAT
1417         if (compat) {
1418                 num_counters = compat_tmp.num_counters;
1419                 name = compat_tmp.name;
1420         } else
1421 #endif
1422         {
1423                 num_counters = tmp.num_counters;
1424                 name = tmp.name;
1425         }
1426
1427         if (len != size + num_counters * sizeof(struct xt_counters))
1428                 return -EINVAL;
1429
1430         paddc = vmalloc_node(len - size, numa_node_id());
1431         if (!paddc)
1432                 return -ENOMEM;
1433
1434         if (copy_from_user(paddc, user + size, len - size) != 0) {
1435                 ret = -EFAULT;
1436                 goto free;
1437         }
1438
1439         t = xt_find_table_lock(AF_INET, name);
1440         if (!t || IS_ERR(t)) {
1441                 ret = t ? PTR_ERR(t) : -ENOENT;
1442                 goto free;
1443         }
1444
1445         write_lock_bh(&t->lock);
1446         private = t->private;
1447         if (private->number != num_counters) {
1448                 ret = -EINVAL;
1449                 goto unlock_up_free;
1450         }
1451
1452         i = 0;
1453         /* Choose the copy that is on our node */
1454         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1455         IPT_ENTRY_ITERATE(loc_cpu_entry,
1456                           private->size,
1457                           add_counter_to_entry,
1458                           paddc,
1459                           &i);
1460  unlock_up_free:
1461         write_unlock_bh(&t->lock);
1462         xt_table_unlock(t);
1463         module_put(t->me);
1464  free:
1465         vfree(paddc);
1466
1467         return ret;
1468 }
1469
1470 #ifdef CONFIG_COMPAT
1471 struct compat_ipt_replace {
1472         char                    name[IPT_TABLE_MAXNAMELEN];
1473         u32                     valid_hooks;
1474         u32                     num_entries;
1475         u32                     size;
1476         u32                     hook_entry[NF_INET_NUMHOOKS];
1477         u32                     underflow[NF_INET_NUMHOOKS];
1478         u32                     num_counters;
1479         compat_uptr_t           counters;       /* struct ipt_counters * */
1480         struct compat_ipt_entry entries[0];
1481 };
1482
1483 static int
1484 compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
1485                           compat_uint_t *size, struct xt_counters *counters,
1486                           unsigned int *i)
1487 {
1488         struct ipt_entry_target *t;
1489         struct compat_ipt_entry __user *ce;
1490         u_int16_t target_offset, next_offset;
1491         compat_uint_t origsize;
1492         int ret;
1493
1494         ret = -EFAULT;
1495         origsize = *size;
1496         ce = (struct compat_ipt_entry __user *)*dstptr;
1497         if (copy_to_user(ce, e, sizeof(struct ipt_entry)))
1498                 goto out;
1499
1500         if (copy_to_user(&ce->counters, &counters[*i], sizeof(counters[*i])))
1501                 goto out;
1502
1503         *dstptr += sizeof(struct compat_ipt_entry);
1504         ret = IPT_MATCH_ITERATE(e, xt_compat_match_to_user, dstptr, size);
1505         target_offset = e->target_offset - (origsize - *size);
1506         if (ret)
1507                 goto out;
1508         t = ipt_get_target(e);
1509         ret = xt_compat_target_to_user(t, dstptr, size);
1510         if (ret)
1511                 goto out;
1512         ret = -EFAULT;
1513         next_offset = e->next_offset - (origsize - *size);
1514         if (put_user(target_offset, &ce->target_offset))
1515                 goto out;
1516         if (put_user(next_offset, &ce->next_offset))
1517                 goto out;
1518
1519         (*i)++;
1520         return 0;
1521 out:
1522         return ret;
1523 }
1524
1525 static inline int
1526 compat_find_calc_match(struct ipt_entry_match *m,
1527                        const char *name,
1528                        const struct ipt_ip *ip,
1529                        unsigned int hookmask,
1530                        int *size, int *i)
1531 {
1532         struct xt_match *match;
1533
1534         match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
1535                                                       m->u.user.revision),
1536                                         "ipt_%s", m->u.user.name);
1537         if (IS_ERR(match) || !match) {
1538                 duprintf("compat_check_calc_match: `%s' not found\n",
1539                          m->u.user.name);
1540                 return match ? PTR_ERR(match) : -ENOENT;
1541         }
1542         m->u.kernel.match = match;
1543         *size += xt_compat_match_offset(match);
1544
1545         (*i)++;
1546         return 0;
1547 }
1548
1549 static inline int
1550 compat_release_match(struct ipt_entry_match *m, unsigned int *i)
1551 {
1552         if (i && (*i)-- == 0)
1553                 return 1;
1554
1555         module_put(m->u.kernel.match->me);
1556         return 0;
1557 }
1558
1559 static inline int
1560 compat_release_entry(struct ipt_entry *e, unsigned int *i)
1561 {
1562         struct ipt_entry_target *t;
1563
1564         if (i && (*i)-- == 0)
1565                 return 1;
1566
1567         /* Cleanup all matches */
1568         IPT_MATCH_ITERATE(e, compat_release_match, NULL);
1569         t = ipt_get_target(e);
1570         module_put(t->u.kernel.target->me);
1571         return 0;
1572 }
1573
1574 static inline int
1575 check_compat_entry_size_and_hooks(struct ipt_entry *e,
1576                                   struct xt_table_info *newinfo,
1577                                   unsigned int *size,
1578                                   unsigned char *base,
1579                                   unsigned char *limit,
1580                                   unsigned int *hook_entries,
1581                                   unsigned int *underflows,
1582                                   unsigned int *i,
1583                                   const char *name)
1584 {
1585         struct ipt_entry_target *t;
1586         struct xt_target *target;
1587         unsigned int entry_offset;
1588         int ret, off, h, j;
1589
1590         duprintf("check_compat_entry_size_and_hooks %p\n", e);
1591         if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0
1592             || (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) {
1593                 duprintf("Bad offset %p, limit = %p\n", e, limit);
1594                 return -EINVAL;
1595         }
1596
1597         if (e->next_offset < sizeof(struct compat_ipt_entry) +
1598                              sizeof(struct compat_xt_entry_target)) {
1599                 duprintf("checking: element %p size %u\n",
1600                          e, e->next_offset);
1601                 return -EINVAL;
1602         }
1603
1604         ret = check_entry(e, name);
1605         if (ret)
1606                 return ret;
1607
1608         off = 0;
1609         entry_offset = (void *)e - (void *)base;
1610         j = 0;
1611         ret = IPT_MATCH_ITERATE(e, compat_find_calc_match, name, &e->ip,
1612                                 e->comefrom, &off, &j);
1613         if (ret != 0)
1614                 goto release_matches;
1615
1616         t = ipt_get_target(e);
1617         target = try_then_request_module(xt_find_target(AF_INET,
1618                                                         t->u.user.name,
1619                                                         t->u.user.revision),
1620                                          "ipt_%s", t->u.user.name);
1621         if (IS_ERR(target) || !target) {
1622                 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1623                          t->u.user.name);
1624                 ret = target ? PTR_ERR(target) : -ENOENT;
1625                 goto release_matches;
1626         }
1627         t->u.kernel.target = target;
1628
1629         off += xt_compat_target_offset(target);
1630         *size += off;
1631         ret = compat_add_offset(entry_offset, off);
1632         if (ret)
1633                 goto out;
1634
1635         /* Check hooks & underflows */
1636         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1637                 if ((unsigned char *)e - base == hook_entries[h])
1638                         newinfo->hook_entry[h] = hook_entries[h];
1639                 if ((unsigned char *)e - base == underflows[h])
1640                         newinfo->underflow[h] = underflows[h];
1641         }
1642
1643         /* Clear counters and comefrom */
1644         e->counters = ((struct ipt_counters) { 0, 0 });
1645         e->comefrom = 0;
1646
1647         (*i)++;
1648         return 0;
1649
1650 out:
1651         module_put(t->u.kernel.target->me);
1652 release_matches:
1653         IPT_MATCH_ITERATE(e, compat_release_match, &j);
1654         return ret;
1655 }
1656
1657 static int
1658 compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
1659                             unsigned int *size, const char *name,
1660                             struct xt_table_info *newinfo, unsigned char *base)
1661 {
1662         struct ipt_entry_target *t;
1663         struct xt_target *target;
1664         struct ipt_entry *de;
1665         unsigned int origsize;
1666         int ret, h;
1667
1668         ret = 0;
1669         origsize = *size;
1670         de = (struct ipt_entry *)*dstptr;
1671         memcpy(de, e, sizeof(struct ipt_entry));
1672
1673         *dstptr += sizeof(struct compat_ipt_entry);
1674         ret = IPT_MATCH_ITERATE(e, xt_compat_match_from_user, dstptr, size);
1675         if (ret)
1676                 return ret;
1677         de->target_offset = e->target_offset - (origsize - *size);
1678         t = ipt_get_target(e);
1679         target = t->u.kernel.target;
1680         xt_compat_target_from_user(t, dstptr, size);
1681
1682         de->next_offset = e->next_offset - (origsize - *size);
1683         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1684                 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1685                         newinfo->hook_entry[h] -= origsize - *size;
1686                 if ((unsigned char *)de - base < newinfo->underflow[h])
1687                         newinfo->underflow[h] -= origsize - *size;
1688         }
1689         return ret;
1690 }
1691
1692 static inline int compat_check_entry(struct ipt_entry *e, const char *name,
1693                                      unsigned int *i)
1694 {
1695         int j, ret;
1696
1697         j = 0;
1698         ret = IPT_MATCH_ITERATE(e, check_match, name, &e->ip, e->comefrom, &j);
1699         if (ret)
1700                 goto cleanup_matches;
1701
1702         ret = check_target(e, name);
1703         if (ret)
1704                 goto cleanup_matches;
1705
1706         (*i)++;
1707         return 0;
1708
1709  cleanup_matches:
1710         IPT_MATCH_ITERATE(e, cleanup_match, &j);
1711         return ret;
1712 }
1713
1714 static int
1715 translate_compat_table(const char *name,
1716                        unsigned int valid_hooks,
1717                        struct xt_table_info **pinfo,
1718                        void **pentry0,
1719                        unsigned int total_size,
1720                        unsigned int number,
1721                        unsigned int *hook_entries,
1722                        unsigned int *underflows)
1723 {
1724         unsigned int i, j;
1725         struct xt_table_info *newinfo, *info;
1726         void *pos, *entry0, *entry1;
1727         unsigned int size;
1728         int ret;
1729
1730         info = *pinfo;
1731         entry0 = *pentry0;
1732         size = total_size;
1733         info->number = number;
1734
1735         /* Init all hooks to impossible value. */
1736         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1737                 info->hook_entry[i] = 0xFFFFFFFF;
1738                 info->underflow[i] = 0xFFFFFFFF;
1739         }
1740
1741         duprintf("translate_compat_table: size %u\n", info->size);
1742         j = 0;
1743         xt_compat_lock(AF_INET);
1744         /* Walk through entries, checking offsets. */
1745         ret = IPT_ENTRY_ITERATE(entry0, total_size,
1746                                 check_compat_entry_size_and_hooks,
1747                                 info, &size, entry0,
1748                                 entry0 + total_size,
1749                                 hook_entries, underflows, &j, name);
1750         if (ret != 0)
1751                 goto out_unlock;
1752
1753         ret = -EINVAL;
1754         if (j != number) {
1755                 duprintf("translate_compat_table: %u not %u entries\n",
1756                          j, number);
1757                 goto out_unlock;
1758         }
1759
1760         /* Check hooks all assigned */
1761         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1762                 /* Only hooks which are valid */
1763                 if (!(valid_hooks & (1 << i)))
1764                         continue;
1765                 if (info->hook_entry[i] == 0xFFFFFFFF) {
1766                         duprintf("Invalid hook entry %u %u\n",
1767                                  i, hook_entries[i]);
1768                         goto out_unlock;
1769                 }
1770                 if (info->underflow[i] == 0xFFFFFFFF) {
1771                         duprintf("Invalid underflow %u %u\n",
1772                                  i, underflows[i]);
1773                         goto out_unlock;
1774                 }
1775         }
1776
1777         ret = -ENOMEM;
1778         newinfo = xt_alloc_table_info(size);
1779         if (!newinfo)
1780                 goto out_unlock;
1781
1782         newinfo->number = number;
1783         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1784                 newinfo->hook_entry[i] = info->hook_entry[i];
1785                 newinfo->underflow[i] = info->underflow[i];
1786         }
1787         entry1 = newinfo->entries[raw_smp_processor_id()];
1788         pos = entry1;
1789         size = total_size;
1790         ret = IPT_ENTRY_ITERATE(entry0, total_size,
1791                                 compat_copy_entry_from_user, &pos, &size,
1792                                 name, newinfo, entry1);
1793         compat_flush_offsets();
1794         xt_compat_unlock(AF_INET);
1795         if (ret)
1796                 goto free_newinfo;
1797
1798         ret = -ELOOP;
1799         if (!mark_source_chains(newinfo, valid_hooks, entry1))
1800                 goto free_newinfo;
1801
1802         i = 0;
1803         ret = IPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
1804                                 name, &i);
1805         if (ret) {
1806                 j -= i;
1807                 IPT_ENTRY_ITERATE_CONTINUE(entry1, newinfo->size, i,
1808                                            compat_release_entry, &j);
1809                 IPT_ENTRY_ITERATE(entry1, newinfo->size, cleanup_entry, &i);
1810                 xt_free_table_info(newinfo);
1811                 return ret;
1812         }
1813
1814         /* And one copy for every other CPU */
1815         for_each_possible_cpu(i)
1816                 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1817                         memcpy(newinfo->entries[i], entry1, newinfo->size);
1818
1819         *pinfo = newinfo;
1820         *pentry0 = entry1;
1821         xt_free_table_info(info);
1822         return 0;
1823
1824 free_newinfo:
1825         xt_free_table_info(newinfo);
1826 out:
1827         IPT_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
1828         return ret;
1829 out_unlock:
1830         compat_flush_offsets();
1831         xt_compat_unlock(AF_INET);
1832         goto out;
1833 }
1834
1835 static int
1836 compat_do_replace(void __user *user, unsigned int len)
1837 {
1838         int ret;
1839         struct compat_ipt_replace tmp;
1840         struct xt_table_info *newinfo;
1841         void *loc_cpu_entry;
1842
1843         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1844                 return -EFAULT;
1845
1846         /* Hack: Causes ipchains to give correct error msg --RR */
1847         if (len != sizeof(tmp) + tmp.size)
1848                 return -ENOPROTOOPT;
1849
1850         /* overflow check */
1851         if (tmp.size >= INT_MAX / num_possible_cpus())
1852                 return -ENOMEM;
1853         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1854                 return -ENOMEM;
1855
1856         newinfo = xt_alloc_table_info(tmp.size);
1857         if (!newinfo)
1858                 return -ENOMEM;
1859
1860         /* choose the copy that is our node/cpu */
1861         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1862         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1863                            tmp.size) != 0) {
1864                 ret = -EFAULT;
1865                 goto free_newinfo;
1866         }
1867
1868         ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1869                                      &newinfo, &loc_cpu_entry, tmp.size,
1870                                      tmp.num_entries, tmp.hook_entry,
1871                                      tmp.underflow);
1872         if (ret != 0)
1873                 goto free_newinfo;
1874
1875         duprintf("compat_do_replace: Translated table\n");
1876
1877         ret = __do_replace(tmp.name, tmp.valid_hooks, newinfo,
1878                            tmp.num_counters, compat_ptr(tmp.counters));
1879         if (ret)
1880                 goto free_newinfo_untrans;
1881         return 0;
1882
1883  free_newinfo_untrans:
1884         IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
1885  free_newinfo:
1886         xt_free_table_info(newinfo);
1887         return ret;
1888 }
1889
1890 static int
1891 compat_do_ipt_set_ctl(struct sock *sk,  int cmd, void __user *user,
1892                       unsigned int len)
1893 {
1894         int ret;
1895
1896         if (!capable(CAP_NET_ADMIN))
1897                 return -EPERM;
1898
1899         switch (cmd) {
1900         case IPT_SO_SET_REPLACE:
1901                 ret = compat_do_replace(user, len);
1902                 break;
1903
1904         case IPT_SO_SET_ADD_COUNTERS:
1905                 ret = do_add_counters(user, len, 1);
1906                 break;
1907
1908         default:
1909                 duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
1910                 ret = -EINVAL;
1911         }
1912
1913         return ret;
1914 }
1915
1916 struct compat_ipt_get_entries {
1917         char name[IPT_TABLE_MAXNAMELEN];
1918         compat_uint_t size;
1919         struct compat_ipt_entry entrytable[0];
1920 };
1921
1922 static int
1923 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1924                             void __user *userptr)
1925 {
1926         struct xt_counters *counters;
1927         struct xt_table_info *private = table->private;
1928         void __user *pos;
1929         unsigned int size;
1930         int ret = 0;
1931         void *loc_cpu_entry;
1932         unsigned int i = 0;
1933
1934         counters = alloc_counters(table);
1935         if (IS_ERR(counters))
1936                 return PTR_ERR(counters);
1937
1938         /* choose the copy that is on our node/cpu, ...
1939          * This choice is lazy (because current thread is
1940          * allowed to migrate to another cpu)
1941          */
1942         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1943         pos = userptr;
1944         size = total_size;
1945         ret = IPT_ENTRY_ITERATE(loc_cpu_entry, total_size,
1946                                 compat_copy_entry_to_user,
1947                                 &pos, &size, counters, &i);
1948
1949         vfree(counters);
1950         return ret;
1951 }
1952
1953 static int
1954 compat_get_entries(struct compat_ipt_get_entries __user *uptr, int *len)
1955 {
1956         int ret;
1957         struct compat_ipt_get_entries get;
1958         struct xt_table *t;
1959
1960         if (*len < sizeof(get)) {
1961                 duprintf("compat_get_entries: %u < %u\n",
1962                          *len, (unsigned int)sizeof(get));
1963                 return -EINVAL;
1964         }
1965
1966         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1967                 return -EFAULT;
1968
1969         if (*len != sizeof(struct compat_ipt_get_entries) + get.size) {
1970                 duprintf("compat_get_entries: %u != %u\n", *len,
1971                          (unsigned int)(sizeof(struct compat_ipt_get_entries) +
1972                          get.size));
1973                 return -EINVAL;
1974         }
1975
1976         xt_compat_lock(AF_INET);
1977         t = xt_find_table_lock(AF_INET, get.name);
1978         if (t && !IS_ERR(t)) {
1979                 struct xt_table_info *private = t->private;
1980                 struct xt_table_info info;
1981                 duprintf("t->private->number = %u\n",
1982                          private->number);
1983                 ret = compat_table_info(private, &info);
1984                 if (!ret && get.size == info.size) {
1985                         ret = compat_copy_entries_to_user(private->size,
1986                                                           t, uptr->entrytable);
1987                 } else if (!ret) {
1988                         duprintf("compat_get_entries: I've got %u not %u!\n",
1989                                  private->size,
1990                                  get.size);
1991                         ret = -EINVAL;
1992                 }
1993                 compat_flush_offsets();
1994                 module_put(t->me);
1995                 xt_table_unlock(t);
1996         } else
1997                 ret = t ? PTR_ERR(t) : -ENOENT;
1998
1999         xt_compat_unlock(AF_INET);
2000         return ret;
2001 }
2002
2003 static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
2004
2005 static int
2006 compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2007 {
2008         int ret;
2009
2010         if (!capable(CAP_NET_ADMIN))
2011                 return -EPERM;
2012
2013         switch (cmd) {
2014         case IPT_SO_GET_INFO:
2015                 ret = get_info(user, len, 1);
2016                 break;
2017         case IPT_SO_GET_ENTRIES:
2018                 ret = compat_get_entries(user, len);
2019                 break;
2020         default:
2021                 ret = do_ipt_get_ctl(sk, cmd, user, len);
2022         }
2023         return ret;
2024 }
2025 #endif
2026
2027 static int
2028 do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
2029 {
2030         int ret;
2031
2032         if (!capable(CAP_NET_ADMIN))
2033                 return -EPERM;
2034
2035         switch (cmd) {
2036         case IPT_SO_SET_REPLACE:
2037                 ret = do_replace(user, len);
2038                 break;
2039
2040         case IPT_SO_SET_ADD_COUNTERS:
2041                 ret = do_add_counters(user, len, 0);
2042                 break;
2043
2044         default:
2045                 duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
2046                 ret = -EINVAL;
2047         }
2048
2049         return ret;
2050 }
2051
2052 static int
2053 do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2054 {
2055         int ret;
2056
2057         if (!capable(CAP_NET_ADMIN))
2058                 return -EPERM;
2059
2060         switch (cmd) {
2061         case IPT_SO_GET_INFO:
2062                 ret = get_info(user, len, 0);
2063                 break;
2064
2065         case IPT_SO_GET_ENTRIES:
2066                 ret = get_entries(user, len);
2067                 break;
2068
2069         case IPT_SO_GET_REVISION_MATCH:
2070         case IPT_SO_GET_REVISION_TARGET: {
2071                 struct ipt_get_revision rev;
2072                 int target;
2073
2074                 if (*len != sizeof(rev)) {
2075                         ret = -EINVAL;
2076                         break;
2077                 }
2078                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
2079                         ret = -EFAULT;
2080                         break;
2081                 }
2082
2083                 if (cmd == IPT_SO_GET_REVISION_TARGET)
2084                         target = 1;
2085                 else
2086                         target = 0;
2087
2088                 try_then_request_module(xt_find_revision(AF_INET, rev.name,
2089                                                          rev.revision,
2090                                                          target, &ret),
2091                                         "ipt_%s", rev.name);
2092                 break;
2093         }
2094
2095         default:
2096                 duprintf("do_ipt_get_ctl: unknown request %i\n", cmd);
2097                 ret = -EINVAL;
2098         }
2099
2100         return ret;
2101 }
2102
2103 int ipt_register_table(struct xt_table *table, const struct ipt_replace *repl)
2104 {
2105         int ret;
2106         struct xt_table_info *newinfo;
2107         struct xt_table_info bootstrap
2108                 = { 0, 0, 0, { 0 }, { 0 }, { } };
2109         void *loc_cpu_entry;
2110
2111         newinfo = xt_alloc_table_info(repl->size);
2112         if (!newinfo)
2113                 return -ENOMEM;
2114
2115         /* choose the copy on our node/cpu
2116          * but dont care of preemption
2117          */
2118         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
2119         memcpy(loc_cpu_entry, repl->entries, repl->size);
2120
2121         ret = translate_table(table->name, table->valid_hooks,
2122                               newinfo, loc_cpu_entry, repl->size,
2123                               repl->num_entries,
2124                               repl->hook_entry,
2125                               repl->underflow);
2126         if (ret != 0) {
2127                 xt_free_table_info(newinfo);
2128                 return ret;
2129         }
2130
2131         ret = xt_register_table(table, &bootstrap, newinfo);
2132         if (ret != 0) {
2133                 xt_free_table_info(newinfo);
2134                 return ret;
2135         }
2136
2137         return 0;
2138 }
2139
2140 void ipt_unregister_table(struct xt_table *table)
2141 {
2142         struct xt_table_info *private;
2143         void *loc_cpu_entry;
2144
2145         private = xt_unregister_table(table);
2146
2147         /* Decrease module usage counts and free resources */
2148         loc_cpu_entry = private->entries[raw_smp_processor_id()];
2149         IPT_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, NULL);
2150         xt_free_table_info(private);
2151 }
2152
2153 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
2154 static inline bool
2155 icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
2156                      u_int8_t type, u_int8_t code,
2157                      bool invert)
2158 {
2159         return ((test_type == 0xFF) || (type == test_type && code >= min_code && code <= max_code))
2160                 ^ invert;
2161 }
2162
2163 static bool
2164 icmp_match(const struct sk_buff *skb,
2165            const struct net_device *in,
2166            const struct net_device *out,
2167            const struct xt_match *match,
2168            const void *matchinfo,
2169            int offset,
2170            unsigned int protoff,
2171            bool *hotdrop)
2172 {
2173         struct icmphdr _icmph, *ic;
2174         const struct ipt_icmp *icmpinfo = matchinfo;
2175
2176         /* Must not be a fragment. */
2177         if (offset)
2178                 return false;
2179
2180         ic = skb_header_pointer(skb, protoff, sizeof(_icmph), &_icmph);
2181         if (ic == NULL) {
2182                 /* We've been asked to examine this packet, and we
2183                  * can't.  Hence, no choice but to drop.
2184                  */
2185                 duprintf("Dropping evil ICMP tinygram.\n");
2186                 *hotdrop = true;
2187                 return false;
2188         }
2189
2190         return icmp_type_code_match(icmpinfo->type,
2191                                     icmpinfo->code[0],
2192                                     icmpinfo->code[1],
2193                                     ic->type, ic->code,
2194                                     !!(icmpinfo->invflags&IPT_ICMP_INV));
2195 }
2196
2197 /* Called when user tries to insert an entry of this type. */
2198 static bool
2199 icmp_checkentry(const char *tablename,
2200            const void *info,
2201            const struct xt_match *match,
2202            void *matchinfo,
2203            unsigned int hook_mask)
2204 {
2205         const struct ipt_icmp *icmpinfo = matchinfo;
2206
2207         /* Must specify no unknown invflags */
2208         return !(icmpinfo->invflags & ~IPT_ICMP_INV);
2209 }
2210
2211 /* The built-in targets: standard (NULL) and error. */
2212 static struct xt_target ipt_standard_target __read_mostly = {
2213         .name           = IPT_STANDARD_TARGET,
2214         .targetsize     = sizeof(int),
2215         .family         = AF_INET,
2216 #ifdef CONFIG_COMPAT
2217         .compatsize     = sizeof(compat_int_t),
2218         .compat_from_user = compat_standard_from_user,
2219         .compat_to_user = compat_standard_to_user,
2220 #endif
2221 };
2222
2223 static struct xt_target ipt_error_target __read_mostly = {
2224         .name           = IPT_ERROR_TARGET,
2225         .target         = ipt_error,
2226         .targetsize     = IPT_FUNCTION_MAXNAMELEN,
2227         .family         = AF_INET,
2228 };
2229
2230 static struct nf_sockopt_ops ipt_sockopts = {
2231         .pf             = PF_INET,
2232         .set_optmin     = IPT_BASE_CTL,
2233         .set_optmax     = IPT_SO_SET_MAX+1,
2234         .set            = do_ipt_set_ctl,
2235 #ifdef CONFIG_COMPAT
2236         .compat_set     = compat_do_ipt_set_ctl,
2237 #endif
2238         .get_optmin     = IPT_BASE_CTL,
2239         .get_optmax     = IPT_SO_GET_MAX+1,
2240         .get            = do_ipt_get_ctl,
2241 #ifdef CONFIG_COMPAT
2242         .compat_get     = compat_do_ipt_get_ctl,
2243 #endif
2244         .owner          = THIS_MODULE,
2245 };
2246
2247 static struct xt_match icmp_matchstruct __read_mostly = {
2248         .name           = "icmp",
2249         .match          = icmp_match,
2250         .matchsize      = sizeof(struct ipt_icmp),
2251         .proto          = IPPROTO_ICMP,
2252         .family         = AF_INET,
2253         .checkentry     = icmp_checkentry,
2254 };
2255
2256 static int __init ip_tables_init(void)
2257 {
2258         int ret;
2259
2260         ret = xt_proto_init(AF_INET);
2261         if (ret < 0)
2262                 goto err1;
2263
2264         /* Noone else will be downing sem now, so we won't sleep */
2265         ret = xt_register_target(&ipt_standard_target);
2266         if (ret < 0)
2267                 goto err2;
2268         ret = xt_register_target(&ipt_error_target);
2269         if (ret < 0)
2270                 goto err3;
2271         ret = xt_register_match(&icmp_matchstruct);
2272         if (ret < 0)
2273                 goto err4;
2274
2275         /* Register setsockopt */
2276         ret = nf_register_sockopt(&ipt_sockopts);
2277         if (ret < 0)
2278                 goto err5;
2279
2280         printk(KERN_INFO "ip_tables: (C) 2000-2006 Netfilter Core Team\n");
2281         return 0;
2282
2283 err5:
2284         xt_unregister_match(&icmp_matchstruct);
2285 err4:
2286         xt_unregister_target(&ipt_error_target);
2287 err3:
2288         xt_unregister_target(&ipt_standard_target);
2289 err2:
2290         xt_proto_fini(AF_INET);
2291 err1:
2292         return ret;
2293 }
2294
2295 static void __exit ip_tables_fini(void)
2296 {
2297         nf_unregister_sockopt(&ipt_sockopts);
2298
2299         xt_unregister_match(&icmp_matchstruct);
2300         xt_unregister_target(&ipt_error_target);
2301         xt_unregister_target(&ipt_standard_target);
2302
2303         xt_proto_fini(AF_INET);
2304 }
2305
2306 EXPORT_SYMBOL(ipt_register_table);
2307 EXPORT_SYMBOL(ipt_unregister_table);
2308 EXPORT_SYMBOL(ipt_do_table);
2309 module_init(ip_tables_init);
2310 module_exit(ip_tables_fini);