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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, unsigned int hookmask,
 604                                 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,
 667                                                       t->data, 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 = NULL;
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] && (e < (struct ipt_entry *)
1113                                 (base + info->hook_entry[i])))
1114                         newinfo->hook_entry[i] -= off;
1115                 if (info->underflow[i] && (e < (struct ipt_entry *)
1116                                 (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, newinfo);
1136 }
1137 #endif
1138
1139 static int get_info(void __user *user, int *len, int compat)
1140 {
1141         char name[IPT_TABLE_MAXNAMELEN];
1142         struct xt_table *t;
1143         int ret;
1144
1145         if (*len != sizeof(struct ipt_getinfo)) {
1146                 duprintf("length %u != %u\n", *len,
1147                         (unsigned int)sizeof(struct ipt_getinfo));
1148                 return -EINVAL;
1149         }
1150
1151         if (copy_from_user(name, user, sizeof(name)) != 0)
1152                 return -EFAULT;
1153
1154         name[IPT_TABLE_MAXNAMELEN-1] = '\0';
1155 #ifdef CONFIG_COMPAT
1156         if (compat)
1157                 xt_compat_lock(AF_INET);
1158 #endif
1159         t = try_then_request_module(xt_find_table_lock(AF_INET, name),
1160                         "iptable_%s", name);
1161         if (t && !IS_ERR(t)) {
1162                 struct ipt_getinfo info;
1163                 struct xt_table_info *private = t->private;
1164
1165 #ifdef CONFIG_COMPAT
1166                 if (compat) {
1167                         struct xt_table_info tmp;
1168                         ret = compat_table_info(private, &tmp);
1169                         compat_flush_offsets();
1170                         private =  &tmp;
1171                 }
1172 #endif
1173                 info.valid_hooks = t->valid_hooks;
1174                 memcpy(info.hook_entry, private->hook_entry,
1175                                 sizeof(info.hook_entry));
1176                 memcpy(info.underflow, private->underflow,
1177                                 sizeof(info.underflow));
1178                 info.num_entries = private->number;
1179                 info.size = private->size;
1180                 strcpy(info.name, name);
1181
1182                 if (copy_to_user(user, &info, *len) != 0)
1183                         ret = -EFAULT;
1184                 else
1185                         ret = 0;
1186
1187                 xt_table_unlock(t);
1188                 module_put(t->me);
1189         } else
1190                 ret = t ? PTR_ERR(t) : -ENOENT;
1191 #ifdef CONFIG_COMPAT
1192         if (compat)
1193                 xt_compat_unlock(AF_INET);
1194 #endif
1195         return ret;
1196 }
1197
1198 static int
1199 get_entries(struct ipt_get_entries __user *uptr, int *len)
1200 {
1201         int ret;
1202         struct ipt_get_entries get;
1203         struct xt_table *t;
1204
1205         if (*len < sizeof(get)) {
1206                 duprintf("get_entries: %u < %d\n", *len,
1207                                 (unsigned int)sizeof(get));
1208                 return -EINVAL;
1209         }
1210         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1211                 return -EFAULT;
1212         if (*len != sizeof(struct ipt_get_entries) + get.size) {
1213                 duprintf("get_entries: %u != %u\n", *len,
1214                                 (unsigned int)(sizeof(struct ipt_get_entries) +
1215                                 get.size));
1216                 return -EINVAL;
1217         }
1218
1219         t = xt_find_table_lock(AF_INET, get.name);
1220         if (t && !IS_ERR(t)) {
1221                 struct xt_table_info *private = t->private;
1222                 duprintf("t->private->number = %u\n",
1223                          private->number);
1224                 if (get.size == private->size)
1225                         ret = copy_entries_to_user(private->size,
1226                                                    t, uptr->entrytable);
1227                 else {
1228                         duprintf("get_entries: I've got %u not %u!\n",
1229                                  private->size,
1230                                  get.size);
1231                         ret = -EINVAL;
1232                 }
1233                 module_put(t->me);
1234                 xt_table_unlock(t);
1235         } else
1236                 ret = t ? PTR_ERR(t) : -ENOENT;
1237
1238         return ret;
1239 }
1240
1241 static int
1242 __do_replace(const char *name, unsigned int valid_hooks,
1243                 struct xt_table_info *newinfo, unsigned int num_counters,
1244                 void __user *counters_ptr)
1245 {
1246         int ret;
1247         struct xt_table *t;
1248         struct xt_table_info *oldinfo;
1249         struct xt_counters *counters;
1250         void *loc_cpu_old_entry;
1251
1252         ret = 0;
1253         counters = vmalloc(num_counters * sizeof(struct xt_counters));
1254         if (!counters) {
1255                 ret = -ENOMEM;
1256                 goto out;
1257         }
1258
1259         t = try_then_request_module(xt_find_table_lock(AF_INET, name),
1260                                     "iptable_%s", name);
1261         if (!t || IS_ERR(t)) {
1262                 ret = t ? PTR_ERR(t) : -ENOENT;
1263                 goto free_newinfo_counters_untrans;
1264         }
1265
1266         /* You lied! */
1267         if (valid_hooks != t->valid_hooks) {
1268                 duprintf("Valid hook crap: %08X vs %08X\n",
1269                          valid_hooks, t->valid_hooks);
1270                 ret = -EINVAL;
1271                 goto put_module;
1272         }
1273
1274         oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1275         if (!oldinfo)
1276                 goto put_module;
1277
1278         /* Update module usage count based on number of rules */
1279         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1280                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1281         if ((oldinfo->number > oldinfo->initial_entries) ||
1282             (newinfo->number <= oldinfo->initial_entries))
1283                 module_put(t->me);
1284         if ((oldinfo->number > oldinfo->initial_entries) &&
1285             (newinfo->number <= oldinfo->initial_entries))
1286                 module_put(t->me);
1287
1288         /* Get the old counters. */
1289         get_counters(oldinfo, counters);
1290         /* Decrease module usage counts and free resource */
1291         loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1292         IPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL);
1293         xt_free_table_info(oldinfo);
1294         if (copy_to_user(counters_ptr, counters,
1295                          sizeof(struct xt_counters) * num_counters) != 0)
1296                 ret = -EFAULT;
1297         vfree(counters);
1298         xt_table_unlock(t);
1299         return ret;
1300
1301  put_module:
1302         module_put(t->me);
1303         xt_table_unlock(t);
1304  free_newinfo_counters_untrans:
1305         vfree(counters);
1306  out:
1307         return ret;
1308 }
1309
1310 static int
1311 do_replace(void __user *user, unsigned int len)
1312 {
1313         int ret;
1314         struct ipt_replace tmp;
1315         struct xt_table_info *newinfo;
1316         void *loc_cpu_entry;
1317
1318         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1319                 return -EFAULT;
1320
1321         /* Hack: Causes ipchains to give correct error msg --RR */
1322         if (len != sizeof(tmp) + tmp.size)
1323                 return -ENOPROTOOPT;
1324
1325         /* overflow check */
1326         if (tmp.size >= INT_MAX / num_possible_cpus())
1327                 return -ENOMEM;
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,
1352                               newinfo, tmp.num_counters,
1353                               tmp.counters);
1354         if (ret)
1355                 goto free_newinfo_untrans;
1356         return 0;
1357
1358  free_newinfo_untrans:
1359         IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
1360  free_newinfo:
1361         xt_free_table_info(newinfo);
1362         return ret;
1363 }
1364
1365 /* We're lazy, and add to the first CPU; overflow works its fey magic
1366  * and everything is OK. */
1367 static inline int
1368 add_counter_to_entry(struct ipt_entry *e,
1369                      const struct xt_counters addme[],
1370                      unsigned int *i)
1371 {
1372 #if 0
1373         duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n",
1374                  *i,
1375                  (long unsigned int)e->counters.pcnt,
1376                  (long unsigned int)e->counters.bcnt,
1377                  (long unsigned int)addme[*i].pcnt,
1378                  (long unsigned int)addme[*i].bcnt);
1379 #endif
1380
1381         ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
1382
1383         (*i)++;
1384         return 0;
1385 }
1386
1387 static int
1388 do_add_counters(void __user *user, unsigned int len, int compat)
1389 {
1390         unsigned int i;
1391         struct xt_counters_info tmp;
1392         struct xt_counters *paddc;
1393         unsigned int num_counters;
1394         char *name;
1395         int size;
1396         void *ptmp;
1397         struct xt_table *t;
1398         struct xt_table_info *private;
1399         int ret = 0;
1400         void *loc_cpu_entry;
1401 #ifdef CONFIG_COMPAT
1402         struct compat_xt_counters_info compat_tmp;
1403
1404         if (compat) {
1405                 ptmp = &compat_tmp;
1406                 size = sizeof(struct compat_xt_counters_info);
1407         } else
1408 #endif
1409         {
1410                 ptmp = &tmp;
1411                 size = sizeof(struct xt_counters_info);
1412         }
1413
1414         if (copy_from_user(ptmp, user, size) != 0)
1415                 return -EFAULT;
1416
1417 #ifdef CONFIG_COMPAT
1418         if (compat) {
1419                 num_counters = compat_tmp.num_counters;
1420                 name = compat_tmp.name;
1421         } else
1422 #endif
1423         {
1424                 num_counters = tmp.num_counters;
1425                 name = tmp.name;
1426         }
1427
1428         if (len != size + num_counters * sizeof(struct xt_counters))
1429                 return -EINVAL;
1430
1431         paddc = vmalloc_node(len - size, numa_node_id());
1432         if (!paddc)
1433                 return -ENOMEM;
1434
1435         if (copy_from_user(paddc, user + size, len - size) != 0) {
1436                 ret = -EFAULT;
1437                 goto free;
1438         }
1439
1440         t = xt_find_table_lock(AF_INET, name);
1441         if (!t || IS_ERR(t)) {
1442                 ret = t ? PTR_ERR(t) : -ENOENT;
1443                 goto free;
1444         }
1445
1446         write_lock_bh(&t->lock);
1447         private = t->private;
1448         if (private->number != num_counters) {
1449                 ret = -EINVAL;
1450                 goto unlock_up_free;
1451         }
1452
1453         i = 0;
1454         /* Choose the copy that is on our node */
1455         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1456         IPT_ENTRY_ITERATE(loc_cpu_entry,
1457                           private->size,
1458                           add_counter_to_entry,
1459                           paddc,
1460                           &i);
1461  unlock_up_free:
1462         write_unlock_bh(&t->lock);
1463         xt_table_unlock(t);
1464         module_put(t->me);
1465  free:
1466         vfree(paddc);
1467
1468         return ret;
1469 }
1470
1471 #ifdef CONFIG_COMPAT
1472 struct compat_ipt_replace {
1473         char                    name[IPT_TABLE_MAXNAMELEN];
1474         u32                     valid_hooks;
1475         u32                     num_entries;
1476         u32                     size;
1477         u32                     hook_entry[NF_INET_NUMHOOKS];
1478         u32                     underflow[NF_INET_NUMHOOKS];
1479         u32                     num_counters;
1480         compat_uptr_t           counters;       /* struct ipt_counters * */
1481         struct compat_ipt_entry entries[0];
1482 };
1483
1484 static inline int compat_copy_match_to_user(struct ipt_entry_match *m,
1485                 void __user **dstptr, compat_uint_t *size)
1486 {
1487         return xt_compat_match_to_user(m, dstptr, size);
1488 }
1489
1490 static int
1491 compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
1492                           compat_uint_t *size, struct xt_counters *counters,
1493                           unsigned int *i)
1494 {
1495         struct ipt_entry_target *t;
1496         struct compat_ipt_entry __user *ce;
1497         u_int16_t target_offset, next_offset;
1498         compat_uint_t origsize;
1499         int ret;
1500
1501         ret = -EFAULT;
1502         origsize = *size;
1503         ce = (struct compat_ipt_entry __user *)*dstptr;
1504         if (copy_to_user(ce, e, sizeof(struct ipt_entry)))
1505                 goto out;
1506
1507         if (copy_to_user(&ce->counters, &counters[*i], sizeof(counters[*i])))
1508                 goto out;
1509
1510         *dstptr += sizeof(struct compat_ipt_entry);
1511         ret = IPT_MATCH_ITERATE(e, compat_copy_match_to_user, dstptr, size);
1512         target_offset = e->target_offset - (origsize - *size);
1513         if (ret)
1514                 goto out;
1515         t = ipt_get_target(e);
1516         ret = xt_compat_target_to_user(t, dstptr, size);
1517         if (ret)
1518                 goto out;
1519         ret = -EFAULT;
1520         next_offset = e->next_offset - (origsize - *size);
1521         if (put_user(target_offset, &ce->target_offset))
1522                 goto out;
1523         if (put_user(next_offset, &ce->next_offset))
1524                 goto out;
1525
1526         (*i)++;
1527         return 0;
1528 out:
1529         return ret;
1530 }
1531
1532 static inline int
1533 compat_find_calc_match(struct ipt_entry_match *m,
1534             const char *name,
1535             const struct ipt_ip *ip,
1536             unsigned int hookmask,
1537             int *size, int *i)
1538 {
1539         struct xt_match *match;
1540
1541         match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
1542                                                    m->u.user.revision),
1543                                         "ipt_%s", m->u.user.name);
1544         if (IS_ERR(match) || !match) {
1545                 duprintf("compat_check_calc_match: `%s' not found\n",
1546                                 m->u.user.name);
1547                 return match ? PTR_ERR(match) : -ENOENT;
1548         }
1549         m->u.kernel.match = match;
1550         *size += xt_compat_match_offset(match);
1551
1552         (*i)++;
1553         return 0;
1554 }
1555
1556 static inline int
1557 compat_release_match(struct ipt_entry_match *m, unsigned int *i)
1558 {
1559         if (i && (*i)-- == 0)
1560                 return 1;
1561
1562         module_put(m->u.kernel.match->me);
1563         return 0;
1564 }
1565
1566 static inline int
1567 compat_release_entry(struct ipt_entry *e, unsigned int *i)
1568 {
1569         struct ipt_entry_target *t;
1570
1571         if (i && (*i)-- == 0)
1572                 return 1;
1573
1574         /* Cleanup all matches */
1575         IPT_MATCH_ITERATE(e, compat_release_match, NULL);
1576         t = ipt_get_target(e);
1577         module_put(t->u.kernel.target->me);
1578         return 0;
1579 }
1580
1581 static inline int
1582 check_compat_entry_size_and_hooks(struct ipt_entry *e,
1583                            struct xt_table_info *newinfo,
1584                            unsigned int *size,
1585                            unsigned char *base,
1586                            unsigned char *limit,
1587                            unsigned int *hook_entries,
1588                            unsigned int *underflows,
1589                            unsigned int *i,
1590                            const char *name)
1591 {
1592         struct ipt_entry_target *t;
1593         struct xt_target *target;
1594         unsigned int entry_offset;
1595         int ret, off, h, j;
1596
1597         duprintf("check_compat_entry_size_and_hooks %p\n", e);
1598         if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0
1599             || (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) {
1600                 duprintf("Bad offset %p, limit = %p\n", e, limit);
1601                 return -EINVAL;
1602         }
1603
1604         if (e->next_offset < sizeof(struct compat_ipt_entry) +
1605                         sizeof(struct compat_xt_entry_target)) {
1606                 duprintf("checking: element %p size %u\n",
1607                          e, e->next_offset);
1608                 return -EINVAL;
1609         }
1610
1611         ret = check_entry(e, name);
1612         if (ret)
1613                 return ret;
1614
1615         off = 0;
1616         entry_offset = (void *)e - (void *)base;
1617         j = 0;
1618         ret = IPT_MATCH_ITERATE(e, compat_find_calc_match, name, &e->ip,
1619                         e->comefrom, &off, &j);
1620         if (ret != 0)
1621                 goto release_matches;
1622
1623         t = ipt_get_target(e);
1624         target = try_then_request_module(xt_find_target(AF_INET,
1625                                                      t->u.user.name,
1626                                                      t->u.user.revision),
1627                                          "ipt_%s", t->u.user.name);
1628         if (IS_ERR(target) || !target) {
1629                 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1630                                                         t->u.user.name);
1631                 ret = target ? PTR_ERR(target) : -ENOENT;
1632                 goto release_matches;
1633         }
1634         t->u.kernel.target = target;
1635
1636         off += xt_compat_target_offset(target);
1637         *size += off;
1638         ret = compat_add_offset(entry_offset, off);
1639         if (ret)
1640                 goto out;
1641
1642         /* Check hooks & underflows */
1643         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1644                 if ((unsigned char *)e - base == hook_entries[h])
1645                         newinfo->hook_entry[h] = hook_entries[h];
1646                 if ((unsigned char *)e - base == underflows[h])
1647                         newinfo->underflow[h] = underflows[h];
1648         }
1649
1650         /* Clear counters and comefrom */
1651         e->counters = ((struct ipt_counters) { 0, 0 });
1652         e->comefrom = 0;
1653
1654         (*i)++;
1655         return 0;
1656
1657 out:
1658         module_put(t->u.kernel.target->me);
1659 release_matches:
1660         IPT_MATCH_ITERATE(e, compat_release_match, &j);
1661         return ret;
1662 }
1663
1664 static inline int compat_copy_match_from_user(struct ipt_entry_match *m,
1665         void **dstptr, compat_uint_t *size, const char *name,
1666         const struct ipt_ip *ip, unsigned int hookmask)
1667 {
1668         xt_compat_match_from_user(m, dstptr, size);
1669         return 0;
1670 }
1671
1672 static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
1673         unsigned int *size, const char *name,
1674         struct xt_table_info *newinfo, unsigned char *base)
1675 {
1676         struct ipt_entry_target *t;
1677         struct xt_target *target;
1678         struct ipt_entry *de;
1679         unsigned int origsize;
1680         int ret, h;
1681
1682         ret = 0;
1683         origsize = *size;
1684         de = (struct ipt_entry *)*dstptr;
1685         memcpy(de, e, sizeof(struct ipt_entry));
1686
1687         *dstptr += sizeof(struct compat_ipt_entry);
1688         ret = IPT_MATCH_ITERATE(e, compat_copy_match_from_user, dstptr, size,
1689                         name, &de->ip, de->comefrom);
1690         if (ret)
1691                 return ret;
1692         de->target_offset = e->target_offset - (origsize - *size);
1693         t = ipt_get_target(e);
1694         target = t->u.kernel.target;
1695         xt_compat_target_from_user(t, dstptr, size);
1696
1697         de->next_offset = e->next_offset - (origsize - *size);
1698         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1699                 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1700                         newinfo->hook_entry[h] -= origsize - *size;
1701                 if ((unsigned char *)de - base < newinfo->underflow[h])
1702                         newinfo->underflow[h] -= origsize - *size;
1703         }
1704         return ret;
1705 }
1706
1707 static inline int compat_check_entry(struct ipt_entry *e, const char *name,
1708                                                 unsigned int *i)
1709 {
1710         int j, ret;
1711
1712         j = 0;
1713         ret = IPT_MATCH_ITERATE(e, check_match, name, &e->ip, e->comefrom, &j);
1714         if (ret)
1715                 goto cleanup_matches;
1716
1717         ret = check_target(e, name);
1718         if (ret)
1719                 goto cleanup_matches;
1720
1721         (*i)++;
1722         return 0;
1723
1724  cleanup_matches:
1725         IPT_MATCH_ITERATE(e, cleanup_match, &j);
1726         return ret;
1727 }
1728
1729 static int
1730 translate_compat_table(const char *name,
1731                 unsigned int valid_hooks,
1732                 struct xt_table_info **pinfo,
1733                 void **pentry0,
1734                 unsigned int total_size,
1735                 unsigned int number,
1736                 unsigned int *hook_entries,
1737                 unsigned int *underflows)
1738 {
1739         unsigned int i, j;
1740         struct xt_table_info *newinfo, *info;
1741         void *pos, *entry0, *entry1;
1742         unsigned int size;
1743         int ret;
1744
1745         info = *pinfo;
1746         entry0 = *pentry0;
1747         size = total_size;
1748         info->number = number;
1749
1750         /* Init all hooks to impossible value. */
1751         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1752                 info->hook_entry[i] = 0xFFFFFFFF;
1753                 info->underflow[i] = 0xFFFFFFFF;
1754         }
1755
1756         duprintf("translate_compat_table: size %u\n", info->size);
1757         j = 0;
1758         xt_compat_lock(AF_INET);
1759         /* Walk through entries, checking offsets. */
1760         ret = IPT_ENTRY_ITERATE(entry0, total_size,
1761                                 check_compat_entry_size_and_hooks,
1762                                 info, &size, entry0,
1763                                 entry0 + total_size,
1764                                 hook_entries, underflows, &j, name);
1765         if (ret != 0)
1766                 goto out_unlock;
1767
1768         ret = -EINVAL;
1769         if (j != number) {
1770                 duprintf("translate_compat_table: %u not %u entries\n",
1771                          j, number);
1772                 goto out_unlock;
1773         }
1774
1775         /* Check hooks all assigned */
1776         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1777                 /* Only hooks which are valid */
1778                 if (!(valid_hooks & (1 << i)))
1779                         continue;
1780                 if (info->hook_entry[i] == 0xFFFFFFFF) {
1781                         duprintf("Invalid hook entry %u %u\n",
1782                                  i, hook_entries[i]);
1783                         goto out_unlock;
1784                 }
1785                 if (info->underflow[i] == 0xFFFFFFFF) {
1786                         duprintf("Invalid underflow %u %u\n",
1787                                  i, underflows[i]);
1788                         goto out_unlock;
1789                 }
1790         }
1791
1792         ret = -ENOMEM;
1793         newinfo = xt_alloc_table_info(size);
1794         if (!newinfo)
1795                 goto out_unlock;
1796
1797         newinfo->number = number;
1798         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1799                 newinfo->hook_entry[i] = info->hook_entry[i];
1800                 newinfo->underflow[i] = info->underflow[i];
1801         }
1802         entry1 = newinfo->entries[raw_smp_processor_id()];
1803         pos = entry1;
1804         size =  total_size;
1805         ret = IPT_ENTRY_ITERATE(entry0, total_size,
1806                         compat_copy_entry_from_user, &pos, &size,
1807                         name, newinfo, entry1);
1808         compat_flush_offsets();
1809         xt_compat_unlock(AF_INET);
1810         if (ret)
1811                 goto free_newinfo;
1812
1813         ret = -ELOOP;
1814         if (!mark_source_chains(newinfo, valid_hooks, entry1))
1815                 goto free_newinfo;
1816
1817         i = 0;
1818         ret = IPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
1819                                                                 name, &i);
1820         if (ret) {
1821                 j -= i;
1822                 IPT_ENTRY_ITERATE_CONTINUE(entry1, newinfo->size, i,
1823                                                 compat_release_entry, &j);
1824                 IPT_ENTRY_ITERATE(entry1, newinfo->size, cleanup_entry, &i);
1825                 xt_free_table_info(newinfo);
1826                 return ret;
1827         }
1828
1829         /* And one copy for every other CPU */
1830         for_each_possible_cpu(i)
1831                 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1832                         memcpy(newinfo->entries[i], entry1, newinfo->size);
1833
1834         *pinfo = newinfo;
1835         *pentry0 = entry1;
1836         xt_free_table_info(info);
1837         return 0;
1838
1839 free_newinfo:
1840         xt_free_table_info(newinfo);
1841 out:
1842         IPT_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
1843         return ret;
1844 out_unlock:
1845         compat_flush_offsets();
1846         xt_compat_unlock(AF_INET);
1847         goto out;
1848 }
1849
1850 static int
1851 compat_do_replace(void __user *user, unsigned int len)
1852 {
1853         int ret;
1854         struct compat_ipt_replace tmp;
1855         struct xt_table_info *newinfo;
1856         void *loc_cpu_entry;
1857
1858         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1859                 return -EFAULT;
1860
1861         /* Hack: Causes ipchains to give correct error msg --RR */
1862         if (len != sizeof(tmp) + tmp.size)
1863                 return -ENOPROTOOPT;
1864
1865         /* overflow check */
1866         if (tmp.size >= INT_MAX / num_possible_cpus())
1867                 return -ENOMEM;
1868         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1869                 return -ENOMEM;
1870
1871         newinfo = xt_alloc_table_info(tmp.size);
1872         if (!newinfo)
1873                 return -ENOMEM;
1874
1875         /* choose the copy that is our node/cpu */
1876         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1877         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1878                            tmp.size) != 0) {
1879                 ret = -EFAULT;
1880                 goto free_newinfo;
1881         }
1882
1883         ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1884                               &newinfo, &loc_cpu_entry, tmp.size,
1885                               tmp.num_entries, tmp.hook_entry, tmp.underflow);
1886         if (ret != 0)
1887                 goto free_newinfo;
1888
1889         duprintf("compat_do_replace: Translated table\n");
1890
1891         ret = __do_replace(tmp.name, tmp.valid_hooks,
1892                               newinfo, tmp.num_counters,
1893                               compat_ptr(tmp.counters));
1894         if (ret)
1895                 goto free_newinfo_untrans;
1896         return 0;
1897
1898  free_newinfo_untrans:
1899         IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
1900  free_newinfo:
1901         xt_free_table_info(newinfo);
1902         return ret;
1903 }
1904
1905 static int
1906 compat_do_ipt_set_ctl(struct sock *sk,  int cmd, void __user *user,
1907                 unsigned int len)
1908 {
1909         int ret;
1910
1911         if (!capable(CAP_NET_ADMIN))
1912                 return -EPERM;
1913
1914         switch (cmd) {
1915         case IPT_SO_SET_REPLACE:
1916                 ret = compat_do_replace(user, len);
1917                 break;
1918
1919         case IPT_SO_SET_ADD_COUNTERS:
1920                 ret = do_add_counters(user, len, 1);
1921                 break;
1922
1923         default:
1924                 duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
1925                 ret = -EINVAL;
1926         }
1927
1928         return ret;
1929 }
1930
1931 struct compat_ipt_get_entries
1932 {
1933         char name[IPT_TABLE_MAXNAMELEN];
1934         compat_uint_t size;
1935         struct compat_ipt_entry entrytable[0];
1936 };
1937
1938 static int compat_copy_entries_to_user(unsigned int total_size,
1939                      struct xt_table *table, void __user *userptr)
1940 {
1941         struct xt_counters *counters;
1942         struct xt_table_info *private = table->private;
1943         void __user *pos;
1944         unsigned int size;
1945         int ret = 0;
1946         void *loc_cpu_entry;
1947         unsigned int i = 0;
1948
1949         counters = alloc_counters(table);
1950         if (IS_ERR(counters))
1951                 return PTR_ERR(counters);
1952
1953         /* choose the copy that is on our node/cpu, ...
1954          * This choice is lazy (because current thread is
1955          * allowed to migrate to another cpu)
1956          */
1957         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1958         pos = userptr;
1959         size = total_size;
1960         ret = IPT_ENTRY_ITERATE(loc_cpu_entry, total_size,
1961                                 compat_copy_entry_to_user,
1962                                 &pos, &size, counters, &i);
1963
1964         vfree(counters);
1965         return ret;
1966 }
1967
1968 static int
1969 compat_get_entries(struct compat_ipt_get_entries __user *uptr, int *len)
1970 {
1971         int ret;
1972         struct compat_ipt_get_entries get;
1973         struct xt_table *t;
1974
1975
1976         if (*len < sizeof(get)) {
1977                 duprintf("compat_get_entries: %u < %u\n",
1978                                 *len, (unsigned int)sizeof(get));
1979                 return -EINVAL;
1980         }
1981
1982         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1983                 return -EFAULT;
1984
1985         if (*len != sizeof(struct compat_ipt_get_entries) + get.size) {
1986                 duprintf("compat_get_entries: %u != %u\n", *len,
1987                         (unsigned int)(sizeof(struct compat_ipt_get_entries) +
1988                         get.size));
1989                 return -EINVAL;
1990         }
1991
1992         xt_compat_lock(AF_INET);
1993         t = xt_find_table_lock(AF_INET, get.name);
1994         if (t && !IS_ERR(t)) {
1995                 struct xt_table_info *private = t->private;
1996                 struct xt_table_info info;
1997                 duprintf("t->private->number = %u\n",
1998                          private->number);
1999                 ret = compat_table_info(private, &info);
2000                 if (!ret && get.size == info.size) {
2001                         ret = compat_copy_entries_to_user(private->size,
2002                                                    t, uptr->entrytable);
2003                 } else if (!ret) {
2004                         duprintf("compat_get_entries: I've got %u not %u!\n",
2005                                  private->size,
2006                                  get.size);
2007                         ret = -EINVAL;
2008                 }
2009                 compat_flush_offsets();
2010                 module_put(t->me);
2011                 xt_table_unlock(t);
2012         } else
2013                 ret = t ? PTR_ERR(t) : -ENOENT;
2014
2015         xt_compat_unlock(AF_INET);
2016         return ret;
2017 }
2018
2019 static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
2020
2021 static int
2022 compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2023 {
2024         int ret;
2025
2026         if (!capable(CAP_NET_ADMIN))
2027                 return -EPERM;
2028
2029         switch (cmd) {
2030         case IPT_SO_GET_INFO:
2031                 ret = get_info(user, len, 1);
2032                 break;
2033         case IPT_SO_GET_ENTRIES:
2034                 ret = compat_get_entries(user, len);
2035                 break;
2036         default:
2037                 ret = do_ipt_get_ctl(sk, cmd, user, len);
2038         }
2039         return ret;
2040 }
2041 #endif
2042
2043 static int
2044 do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
2045 {
2046         int ret;
2047
2048         if (!capable(CAP_NET_ADMIN))
2049                 return -EPERM;
2050
2051         switch (cmd) {
2052         case IPT_SO_SET_REPLACE:
2053                 ret = do_replace(user, len);
2054                 break;
2055
2056         case IPT_SO_SET_ADD_COUNTERS:
2057                 ret = do_add_counters(user, len, 0);
2058                 break;
2059
2060         default:
2061                 duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
2062                 ret = -EINVAL;
2063         }
2064
2065         return ret;
2066 }
2067
2068 static int
2069 do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2070 {
2071         int ret;
2072
2073         if (!capable(CAP_NET_ADMIN))
2074                 return -EPERM;
2075
2076         switch (cmd) {
2077         case IPT_SO_GET_INFO:
2078                 ret = get_info(user, len, 0);
2079                 break;
2080
2081         case IPT_SO_GET_ENTRIES:
2082                 ret = get_entries(user, len);
2083                 break;
2084
2085         case IPT_SO_GET_REVISION_MATCH:
2086         case IPT_SO_GET_REVISION_TARGET: {
2087                 struct ipt_get_revision rev;
2088                 int target;
2089
2090                 if (*len != sizeof(rev)) {
2091                         ret = -EINVAL;
2092                         break;
2093                 }
2094                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
2095                         ret = -EFAULT;
2096                         break;
2097                 }
2098
2099                 if (cmd == IPT_SO_GET_REVISION_TARGET)
2100                         target = 1;
2101                 else
2102                         target = 0;
2103
2104                 try_then_request_module(xt_find_revision(AF_INET, rev.name,
2105                                                          rev.revision,
2106                                                          target, &ret),
2107                                         "ipt_%s", rev.name);
2108                 break;
2109         }
2110
2111         default:
2112                 duprintf("do_ipt_get_ctl: unknown request %i\n", cmd);
2113                 ret = -EINVAL;
2114         }
2115
2116         return ret;
2117 }
2118
2119 int ipt_register_table(struct xt_table *table, const struct ipt_replace *repl)
2120 {
2121         int ret;
2122         struct xt_table_info *newinfo;
2123         struct xt_table_info bootstrap
2124                 = { 0, 0, 0, { 0 }, { 0 }, { } };
2125         void *loc_cpu_entry;
2126
2127         newinfo = xt_alloc_table_info(repl->size);
2128         if (!newinfo)
2129                 return -ENOMEM;
2130
2131         /* choose the copy on our node/cpu
2132          * but dont care of preemption
2133          */
2134         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
2135         memcpy(loc_cpu_entry, repl->entries, repl->size);
2136
2137         ret = translate_table(table->name, table->valid_hooks,
2138                               newinfo, loc_cpu_entry, repl->size,
2139                               repl->num_entries,
2140                               repl->hook_entry,
2141                               repl->underflow);
2142         if (ret != 0) {
2143                 xt_free_table_info(newinfo);
2144                 return ret;
2145         }
2146
2147         ret = xt_register_table(table, &bootstrap, newinfo);
2148         if (ret != 0) {
2149                 xt_free_table_info(newinfo);
2150                 return ret;
2151         }
2152
2153         return 0;
2154 }
2155
2156 void ipt_unregister_table(struct xt_table *table)
2157 {
2158         struct xt_table_info *private;
2159         void *loc_cpu_entry;
2160
2161         private = xt_unregister_table(table);
2162
2163         /* Decrease module usage counts and free resources */
2164         loc_cpu_entry = private->entries[raw_smp_processor_id()];
2165         IPT_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, NULL);
2166         xt_free_table_info(private);
2167 }
2168
2169 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
2170 static inline bool
2171 icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
2172                      u_int8_t type, u_int8_t code,
2173                      bool invert)
2174 {
2175         return ((test_type == 0xFF) || (type == test_type && code >= min_code && code <= max_code))
2176                 ^ invert;
2177 }
2178
2179 static bool
2180 icmp_match(const struct sk_buff *skb,
2181            const struct net_device *in,
2182            const struct net_device *out,
2183            const struct xt_match *match,
2184            const void *matchinfo,
2185            int offset,
2186            unsigned int protoff,
2187            bool *hotdrop)
2188 {
2189         struct icmphdr _icmph, *ic;
2190         const struct ipt_icmp *icmpinfo = matchinfo;
2191
2192         /* Must not be a fragment. */
2193         if (offset)
2194                 return false;
2195
2196         ic = skb_header_pointer(skb, protoff, sizeof(_icmph), &_icmph);
2197         if (ic == NULL) {
2198                 /* We've been asked to examine this packet, and we
2199                  * can't.  Hence, no choice but to drop.
2200                  */
2201                 duprintf("Dropping evil ICMP tinygram.\n");
2202                 *hotdrop = true;
2203                 return false;
2204         }
2205
2206         return icmp_type_code_match(icmpinfo->type,
2207                                     icmpinfo->code[0],
2208                                     icmpinfo->code[1],
2209                                     ic->type, ic->code,
2210                                     !!(icmpinfo->invflags&IPT_ICMP_INV));
2211 }
2212
2213 /* Called when user tries to insert an entry of this type. */
2214 static bool
2215 icmp_checkentry(const char *tablename,
2216            const void *info,
2217            const struct xt_match *match,
2218            void *matchinfo,
2219            unsigned int hook_mask)
2220 {
2221         const struct ipt_icmp *icmpinfo = matchinfo;
2222
2223         /* Must specify no unknown invflags */
2224         return !(icmpinfo->invflags & ~IPT_ICMP_INV);
2225 }
2226
2227 /* The built-in targets: standard (NULL) and error. */
2228 static struct xt_target ipt_standard_target __read_mostly = {
2229         .name           = IPT_STANDARD_TARGET,
2230         .targetsize     = sizeof(int),
2231         .family         = AF_INET,
2232 #ifdef CONFIG_COMPAT
2233         .compatsize     = sizeof(compat_int_t),
2234         .compat_from_user = compat_standard_from_user,
2235         .compat_to_user = compat_standard_to_user,
2236 #endif
2237 };
2238
2239 static struct xt_target ipt_error_target __read_mostly = {
2240         .name           = IPT_ERROR_TARGET,
2241         .target         = ipt_error,
2242         .targetsize     = IPT_FUNCTION_MAXNAMELEN,
2243         .family         = AF_INET,
2244 };
2245
2246 static struct nf_sockopt_ops ipt_sockopts = {
2247         .pf             = PF_INET,
2248         .set_optmin     = IPT_BASE_CTL,
2249         .set_optmax     = IPT_SO_SET_MAX+1,
2250         .set            = do_ipt_set_ctl,
2251 #ifdef CONFIG_COMPAT
2252         .compat_set     = compat_do_ipt_set_ctl,
2253 #endif
2254         .get_optmin     = IPT_BASE_CTL,
2255         .get_optmax     = IPT_SO_GET_MAX+1,
2256         .get            = do_ipt_get_ctl,
2257 #ifdef CONFIG_COMPAT
2258         .compat_get     = compat_do_ipt_get_ctl,
2259 #endif
2260         .owner          = THIS_MODULE,
2261 };
2262
2263 static struct xt_match icmp_matchstruct __read_mostly = {
2264         .name           = "icmp",
2265         .match          = icmp_match,
2266         .matchsize      = sizeof(struct ipt_icmp),
2267         .proto          = IPPROTO_ICMP,
2268         .family         = AF_INET,
2269         .checkentry     = icmp_checkentry,
2270 };
2271
2272 static int __init ip_tables_init(void)
2273 {
2274         int ret;
2275
2276         ret = xt_proto_init(AF_INET);
2277         if (ret < 0)
2278                 goto err1;
2279
2280         /* Noone else will be downing sem now, so we won't sleep */
2281         ret = xt_register_target(&ipt_standard_target);
2282         if (ret < 0)
2283                 goto err2;
2284         ret = xt_register_target(&ipt_error_target);
2285         if (ret < 0)
2286                 goto err3;
2287         ret = xt_register_match(&icmp_matchstruct);
2288         if (ret < 0)
2289                 goto err4;
2290
2291         /* Register setsockopt */
2292         ret = nf_register_sockopt(&ipt_sockopts);
2293         if (ret < 0)
2294                 goto err5;
2295
2296         printk(KERN_INFO "ip_tables: (C) 2000-2006 Netfilter Core Team\n");
2297         return 0;
2298
2299 err5:
2300         xt_unregister_match(&icmp_matchstruct);
2301 err4:
2302         xt_unregister_target(&ipt_error_target);
2303 err3:
2304         xt_unregister_target(&ipt_standard_target);
2305 err2:
2306         xt_proto_fini(AF_INET);
2307 err1:
2308         return ret;
2309 }
2310
2311 static void __exit ip_tables_fini(void)
2312 {
2313         nf_unregister_sockopt(&ipt_sockopts);
2314
2315         xt_unregister_match(&icmp_matchstruct);
2316         xt_unregister_target(&ipt_error_target);
2317         xt_unregister_target(&ipt_standard_target);
2318
2319         xt_proto_fini(AF_INET);
2320 }
2321
2322 EXPORT_SYMBOL(ipt_register_table);
2323 EXPORT_SYMBOL(ipt_unregister_table);
2324 EXPORT_SYMBOL(ipt_do_table);
2325 module_init(ip_tables_init);
2326 module_exit(ip_tables_fini);