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   1 /*
   2  * Packet matching code for ARP packets.
   3  *
   4  * Based heavily, if not almost entirely, upon ip_tables.c framework.
   5  *
   6  * Some ARP specific bits are:
   7  *
   8  * Copyright (C) 2002 David S. Miller (davem@redhat.com)
   9  *
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/capability.h>
  16 #include <linux/if_arp.h>
  17 #include <linux/kmod.h>
  18 #include <linux/vmalloc.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/mutex.h>
  23 #include <linux/err.h>
  24 #include <net/compat.h>
  25 #include <net/sock.h>
  26 #include <asm/uaccess.h>
  27
  28 #include <linux/netfilter/x_tables.h>
  29 #include <linux/netfilter_arp/arp_tables.h>
  30
  31 MODULE_LICENSE("GPL");
  32 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
  33 MODULE_DESCRIPTION("arptables core");
  34
  35 /*#define DEBUG_ARP_TABLES*/
  36 /*#define DEBUG_ARP_TABLES_USER*/
  37
  38 #ifdef DEBUG_ARP_TABLES
  39 #define dprintf(format, args...)  printk(format , ## args)
  40 #else
  41 #define dprintf(format, args...)
  42 #endif
  43
  44 #ifdef DEBUG_ARP_TABLES_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 ARP_NF_ASSERT(x)                                        \
  52 do {                                                            \
  53         if (!(x))                                               \
  54                 printk("ARP_NF_ASSERT: %s:%s:%u\n",             \
  55                        __func__, __FILE__, __LINE__);   \
  56 } while(0)
  57 #else
  58 #define ARP_NF_ASSERT(x)
  59 #endif
  60
  61 static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
  62                                       const char *hdr_addr, int len)
  63 {
  64         int i, ret;
  65
  66         if (len > ARPT_DEV_ADDR_LEN_MAX)
  67                 len = ARPT_DEV_ADDR_LEN_MAX;
  68
  69         ret = 0;
  70         for (i = 0; i < len; i++)
  71                 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
  72
  73         return (ret != 0);
  74 }
  75
  76 /* Returns whether packet matches rule or not. */
  77 static inline int arp_packet_match(const struct arphdr *arphdr,
  78                                    struct net_device *dev,
  79                                    const char *indev,
  80                                    const char *outdev,
  81                                    const struct arpt_arp *arpinfo)
  82 {
  83         const char *arpptr = (char *)(arphdr + 1);
  84         const char *src_devaddr, *tgt_devaddr;
  85         __be32 src_ipaddr, tgt_ipaddr;
  86         int i, ret;
  87
  88 #define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
  89
  90         if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
  91                   ARPT_INV_ARPOP)) {
  92                 dprintf("ARP operation field mismatch.\n");
  93                 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
  94                         arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
  95                 return 0;
  96         }
  97
  98         if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
  99                   ARPT_INV_ARPHRD)) {
 100                 dprintf("ARP hardware address format mismatch.\n");
 101                 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
 102                         arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
 103                 return 0;
 104         }
 105
 106         if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
 107                   ARPT_INV_ARPPRO)) {
 108                 dprintf("ARP protocol address format mismatch.\n");
 109                 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
 110                         arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
 111                 return 0;
 112         }
 113
 114         if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
 115                   ARPT_INV_ARPHLN)) {
 116                 dprintf("ARP hardware address length mismatch.\n");
 117                 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
 118                         arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
 119                 return 0;
 120         }
 121
 122         src_devaddr = arpptr;
 123         arpptr += dev->addr_len;
 124         memcpy(&src_ipaddr, arpptr, sizeof(u32));
 125         arpptr += sizeof(u32);
 126         tgt_devaddr = arpptr;
 127         arpptr += dev->addr_len;
 128         memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
 129
 130         if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
 131                   ARPT_INV_SRCDEVADDR) ||
 132             FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
 133                   ARPT_INV_TGTDEVADDR)) {
 134                 dprintf("Source or target device address mismatch.\n");
 135
 136                 return 0;
 137         }
 138
 139         if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
 140                   ARPT_INV_SRCIP) ||
 141             FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
 142                   ARPT_INV_TGTIP)) {
 143                 dprintf("Source or target IP address mismatch.\n");
 144
 145                 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
 146                         NIPQUAD(src_ipaddr),
 147                         NIPQUAD(arpinfo->smsk.s_addr),
 148                         NIPQUAD(arpinfo->src.s_addr),
 149                         arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
 150                 dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
 151                         NIPQUAD(tgt_ipaddr),
 152                         NIPQUAD(arpinfo->tmsk.s_addr),
 153                         NIPQUAD(arpinfo->tgt.s_addr),
 154                         arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
 155                 return 0;
 156         }
 157
 158         /* Look for ifname matches.  */
 159         for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
 160                 ret |= (indev[i] ^ arpinfo->iniface[i])
 161                         & arpinfo->iniface_mask[i];
 162         }
 163
 164         if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
 165                 dprintf("VIA in mismatch (%s vs %s).%s\n",
 166                         indev, arpinfo->iniface,
 167                         arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
 168                 return 0;
 169         }
 170
 171         for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
 172                 ret |= (outdev[i] ^ arpinfo->outiface[i])
 173                         & arpinfo->outiface_mask[i];
 174         }
 175
 176         if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
 177                 dprintf("VIA out mismatch (%s vs %s).%s\n",
 178                         outdev, arpinfo->outiface,
 179                         arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
 180                 return 0;
 181         }
 182
 183         return 1;
 184 #undef FWINV
 185 }
 186
 187 static inline int arp_checkentry(const struct arpt_arp *arp)
 188 {
 189         if (arp->flags & ~ARPT_F_MASK) {
 190                 duprintf("Unknown flag bits set: %08X\n",
 191                          arp->flags & ~ARPT_F_MASK);
 192                 return 0;
 193         }
 194         if (arp->invflags & ~ARPT_INV_MASK) {
 195                 duprintf("Unknown invflag bits set: %08X\n",
 196                          arp->invflags & ~ARPT_INV_MASK);
 197                 return 0;
 198         }
 199
 200         return 1;
 201 }
 202
 203 static unsigned int
 204 arpt_error(struct sk_buff *skb, const struct xt_target_param *par)
 205 {
 206         if (net_ratelimit())
 207                 printk("arp_tables: error: '%s'\n",
 208                        (const char *)par->targinfo);
 209
 210         return NF_DROP;
 211 }
 212
 213 static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
 214 {
 215         return (struct arpt_entry *)(base + offset);
 216 }
 217
 218 unsigned int arpt_do_table(struct sk_buff *skb,
 219                            unsigned int hook,
 220                            const struct net_device *in,
 221                            const struct net_device *out,
 222                            struct xt_table *table)
 223 {
 224         static const char nulldevname[IFNAMSIZ];
 225         unsigned int verdict = NF_DROP;
 226         const struct arphdr *arp;
 227         bool hotdrop = false;
 228         struct arpt_entry *e, *back;
 229         const char *indev, *outdev;
 230         void *table_base;
 231         const struct xt_table_info *private;
 232         struct xt_target_param tgpar;
 233
 234         if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
 235                 return NF_DROP;
 236
 237         indev = in ? in->name : nulldevname;
 238         outdev = out ? out->name : nulldevname;
 239
 240         read_lock_bh(&table->lock);
 241         private = table->private;
 242         table_base = (void *)private->entries[smp_processor_id()];
 243         e = get_entry(table_base, private->hook_entry[hook]);
 244         back = get_entry(table_base, private->underflow[hook]);
 245
 246         tgpar.in      = in;
 247         tgpar.out     = out;
 248         tgpar.hooknum = hook;
 249
 250         arp = arp_hdr(skb);
 251         do {
 252                 if (arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
 253                         struct arpt_entry_target *t;
 254                         int hdr_len;
 255
 256                         hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
 257                                 (2 * skb->dev->addr_len);
 258                         ADD_COUNTER(e->counters, hdr_len, 1);
 259
 260                         t = arpt_get_target(e);
 261
 262                         /* Standard target? */
 263                         if (!t->u.kernel.target->target) {
 264                                 int v;
 265
 266                                 v = ((struct arpt_standard_target *)t)->verdict;
 267                                 if (v < 0) {
 268                                         /* Pop from stack? */
 269                                         if (v != ARPT_RETURN) {
 270                                                 verdict = (unsigned)(-v) - 1;
 271                                                 break;
 272                                         }
 273                                         e = back;
 274                                         back = get_entry(table_base,
 275                                                          back->comefrom);
 276                                         continue;
 277                                 }
 278                                 if (table_base + v
 279                                     != (void *)e + e->next_offset) {
 280                                         /* Save old back ptr in next entry */
 281                                         struct arpt_entry *next
 282                                                 = (void *)e + e->next_offset;
 283                                         next->comefrom =
 284                                                 (void *)back - table_base;
 285
 286                                         /* set back pointer to next entry */
 287                                         back = next;
 288                                 }
 289
 290                                 e = get_entry(table_base, v);
 291                         } else {
 292                                 /* Targets which reenter must return
 293                                  * abs. verdicts
 294                                  */
 295                                 tgpar.target   = t->u.kernel.target;
 296                                 tgpar.targinfo = t->data;
 297                                 verdict = t->u.kernel.target->target(skb,
 298                                                                      &tgpar);
 299
 300                                 /* Target might have changed stuff. */
 301                                 arp = arp_hdr(skb);
 302
 303                                 if (verdict == ARPT_CONTINUE)
 304                                         e = (void *)e + e->next_offset;
 305                                 else
 306                                         /* Verdict */
 307                                         break;
 308                         }
 309                 } else {
 310                         e = (void *)e + e->next_offset;
 311                 }
 312         } while (!hotdrop);
 313         read_unlock_bh(&table->lock);
 314
 315         if (hotdrop)
 316                 return NF_DROP;
 317         else
 318                 return verdict;
 319 }
 320
 321 /* All zeroes == unconditional rule. */
 322 static inline int unconditional(const struct arpt_arp *arp)
 323 {
 324         unsigned int i;
 325
 326         for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
 327                 if (((__u32 *)arp)[i])
 328                         return 0;
 329
 330         return 1;
 331 }
 332
 333 /* Figures out from what hook each rule can be called: returns 0 if
 334  * there are loops.  Puts hook bitmask in comefrom.
 335  */
 336 static int mark_source_chains(struct xt_table_info *newinfo,
 337                               unsigned int valid_hooks, void *entry0)
 338 {
 339         unsigned int hook;
 340
 341         /* No recursion; use packet counter to save back ptrs (reset
 342          * to 0 as we leave), and comefrom to save source hook bitmask.
 343          */
 344         for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
 345                 unsigned int pos = newinfo->hook_entry[hook];
 346                 struct arpt_entry *e
 347                         = (struct arpt_entry *)(entry0 + pos);
 348
 349                 if (!(valid_hooks & (1 << hook)))
 350                         continue;
 351
 352                 /* Set initial back pointer. */
 353                 e->counters.pcnt = pos;
 354
 355                 for (;;) {
 356                         const struct arpt_standard_target *t
 357                                 = (void *)arpt_get_target(e);
 358                         int visited = e->comefrom & (1 << hook);
 359
 360                         if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
 361                                 printk("arptables: loop hook %u pos %u %08X.\n",
 362                                        hook, pos, e->comefrom);
 363                                 return 0;
 364                         }
 365                         e->comefrom
 366                                 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
 367
 368                         /* Unconditional return/END. */
 369                         if ((e->target_offset == sizeof(struct arpt_entry)
 370                             && (strcmp(t->target.u.user.name,
 371                                        ARPT_STANDARD_TARGET) == 0)
 372                             && t->verdict < 0
 373                             && unconditional(&e->arp)) || visited) {
 374                                 unsigned int oldpos, size;
 375
 376                                 if (t->verdict < -NF_MAX_VERDICT - 1) {
 377                                         duprintf("mark_source_chains: bad "
 378                                                 "negative verdict (%i)\n",
 379                                                                 t->verdict);
 380                                         return 0;
 381                                 }
 382
 383                                 /* Return: backtrack through the last
 384                                  * big jump.
 385                                  */
 386                                 do {
 387                                         e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
 388                                         oldpos = pos;
 389                                         pos = e->counters.pcnt;
 390                                         e->counters.pcnt = 0;
 391
 392                                         /* We're at the start. */
 393                                         if (pos == oldpos)
 394                                                 goto next;
 395
 396                                         e = (struct arpt_entry *)
 397                                                 (entry0 + pos);
 398                                 } while (oldpos == pos + e->next_offset);
 399
 400                                 /* Move along one */
 401                                 size = e->next_offset;
 402                                 e = (struct arpt_entry *)
 403                                         (entry0 + pos + size);
 404                                 e->counters.pcnt = pos;
 405                                 pos += size;
 406                         } else {
 407                                 int newpos = t->verdict;
 408
 409                                 if (strcmp(t->target.u.user.name,
 410                                            ARPT_STANDARD_TARGET) == 0
 411                                     && newpos >= 0) {
 412                                         if (newpos > newinfo->size -
 413                                                 sizeof(struct arpt_entry)) {
 414                                                 duprintf("mark_source_chains: "
 415                                                         "bad verdict (%i)\n",
 416                                                                 newpos);
 417                                                 return 0;
 418                                         }
 419
 420                                         /* This a jump; chase it. */
 421                                         duprintf("Jump rule %u -> %u\n",
 422                                                  pos, newpos);
 423                                 } else {
 424                                         /* ... this is a fallthru */
 425                                         newpos = pos + e->next_offset;
 426                                 }
 427                                 e = (struct arpt_entry *)
 428                                         (entry0 + newpos);
 429                                 e->counters.pcnt = pos;
 430                                 pos = newpos;
 431                         }
 432                 }
 433                 next:
 434                 duprintf("Finished chain %u\n", hook);
 435         }
 436         return 1;
 437 }
 438
 439 static inline int check_entry(struct arpt_entry *e, const char *name)
 440 {
 441         const struct arpt_entry_target *t;
 442
 443         if (!arp_checkentry(&e->arp)) {
 444                 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
 445                 return -EINVAL;
 446         }
 447
 448         if (e->target_offset + sizeof(struct arpt_entry_target) > e->next_offset)
 449                 return -EINVAL;
 450
 451         t = arpt_get_target(e);
 452         if (e->target_offset + t->u.target_size > e->next_offset)
 453                 return -EINVAL;
 454
 455         return 0;
 456 }
 457
 458 static inline int check_target(struct arpt_entry *e, const char *name)
 459 {
 460         struct arpt_entry_target *t = arpt_get_target(e);
 461         int ret;
 462         struct xt_tgchk_param par = {
 463                 .table     = name,
 464                 .entryinfo = e,
 465                 .target    = t->u.kernel.target,
 466                 .targinfo  = t->data,
 467                 .hook_mask = e->comefrom,
 468         };
 469
 470         ret = xt_check_target(&par, NFPROTO_ARP,
 471               t->u.target_size - sizeof(*t), 0, false);
 472         if (ret < 0) {
 473                 duprintf("arp_tables: check failed for `%s'.\n",
 474                          t->u.kernel.target->name);
 475                 return ret;
 476         }
 477         return 0;
 478 }
 479
 480 static inline int
 481 find_check_entry(struct arpt_entry *e, const char *name, unsigned int size,
 482                  unsigned int *i)
 483 {
 484         struct arpt_entry_target *t;
 485         struct xt_target *target;
 486         int ret;
 487
 488         ret = check_entry(e, name);
 489         if (ret)
 490                 return ret;
 491
 492         t = arpt_get_target(e);
 493         target = try_then_request_module(xt_find_target(NFPROTO_ARP,
 494                                                         t->u.user.name,
 495                                                         t->u.user.revision),
 496                                          "arpt_%s", t->u.user.name);
 497         if (IS_ERR(target) || !target) {
 498                 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
 499                 ret = target ? PTR_ERR(target) : -ENOENT;
 500                 goto out;
 501         }
 502         t->u.kernel.target = target;
 503
 504         ret = check_target(e, name);
 505         if (ret)
 506                 goto err;
 507
 508         (*i)++;
 509         return 0;
 510 err:
 511         module_put(t->u.kernel.target->me);
 512 out:
 513         return ret;
 514 }
 515
 516 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
 517                                              struct xt_table_info *newinfo,
 518                                              unsigned char *base,
 519                                              unsigned char *limit,
 520                                              const unsigned int *hook_entries,
 521                                              const unsigned int *underflows,
 522                                              unsigned int *i)
 523 {
 524         unsigned int h;
 525
 526         if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
 527             || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
 528                 duprintf("Bad offset %p\n", e);
 529                 return -EINVAL;
 530         }
 531
 532         if (e->next_offset
 533             < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
 534                 duprintf("checking: element %p size %u\n",
 535                          e, e->next_offset);
 536                 return -EINVAL;
 537         }
 538
 539         /* Check hooks & underflows */
 540         for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
 541                 if ((unsigned char *)e - base == hook_entries[h])
 542                         newinfo->hook_entry[h] = hook_entries[h];
 543                 if ((unsigned char *)e - base == underflows[h])
 544                         newinfo->underflow[h] = underflows[h];
 545         }
 546
 547         /* FIXME: underflows must be unconditional, standard verdicts
 548            < 0 (not ARPT_RETURN). --RR */
 549
 550         /* Clear counters and comefrom */
 551         e->counters = ((struct xt_counters) { 0, 0 });
 552         e->comefrom = 0;
 553
 554         (*i)++;
 555         return 0;
 556 }
 557
 558 static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i)
 559 {
 560         struct xt_tgdtor_param par;
 561         struct arpt_entry_target *t;
 562
 563         if (i && (*i)-- == 0)
 564                 return 1;
 565
 566         t = arpt_get_target(e);
 567         par.target   = t->u.kernel.target;
 568         par.targinfo = t->data;
 569         if (par.target->destroy != NULL)
 570                 par.target->destroy(&par);
 571         module_put(par.target->me);
 572         return 0;
 573 }
 574
 575 /* Checks and translates the user-supplied table segment (held in
 576  * newinfo).
 577  */
 578 static int translate_table(const char *name,
 579                            unsigned int valid_hooks,
 580                            struct xt_table_info *newinfo,
 581                            void *entry0,
 582                            unsigned int size,
 583                            unsigned int number,
 584                            const unsigned int *hook_entries,
 585                            const unsigned int *underflows)
 586 {
 587         unsigned int i;
 588         int ret;
 589
 590         newinfo->size = size;
 591         newinfo->number = number;
 592
 593         /* Init all hooks to impossible value. */
 594         for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
 595                 newinfo->hook_entry[i] = 0xFFFFFFFF;
 596                 newinfo->underflow[i] = 0xFFFFFFFF;
 597         }
 598
 599         duprintf("translate_table: size %u\n", newinfo->size);
 600         i = 0;
 601
 602         /* Walk through entries, checking offsets. */
 603         ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
 604                                  check_entry_size_and_hooks,
 605                                  newinfo,
 606                                  entry0,
 607                                  entry0 + size,
 608                                  hook_entries, underflows, &i);
 609         duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
 610         if (ret != 0)
 611                 return ret;
 612
 613         if (i != number) {
 614                 duprintf("translate_table: %u not %u entries\n",
 615                          i, number);
 616                 return -EINVAL;
 617         }
 618
 619         /* Check hooks all assigned */
 620         for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
 621                 /* Only hooks which are valid */
 622                 if (!(valid_hooks & (1 << i)))
 623                         continue;
 624                 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
 625                         duprintf("Invalid hook entry %u %u\n",
 626                                  i, hook_entries[i]);
 627                         return -EINVAL;
 628                 }
 629                 if (newinfo->underflow[i] == 0xFFFFFFFF) {
 630                         duprintf("Invalid underflow %u %u\n",
 631                                  i, underflows[i]);
 632                         return -EINVAL;
 633                 }
 634         }
 635
 636         if (!mark_source_chains(newinfo, valid_hooks, entry0)) {
 637                 duprintf("Looping hook\n");
 638                 return -ELOOP;
 639         }
 640
 641         /* Finally, each sanity check must pass */
 642         i = 0;
 643         ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
 644                                  find_check_entry, name, size, &i);
 645
 646         if (ret != 0) {
 647                 ARPT_ENTRY_ITERATE(entry0, newinfo->size,
 648                                 cleanup_entry, &i);
 649                 return ret;
 650         }
 651
 652         /* And one copy for every other CPU */
 653         for_each_possible_cpu(i) {
 654                 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
 655                         memcpy(newinfo->entries[i], entry0, newinfo->size);
 656         }
 657
 658         return ret;
 659 }
 660
 661 /* Gets counters. */
 662 static inline int add_entry_to_counter(const struct arpt_entry *e,
 663                                        struct xt_counters total[],
 664                                        unsigned int *i)
 665 {
 666         ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
 667
 668         (*i)++;
 669         return 0;
 670 }
 671
 672 static inline int set_entry_to_counter(const struct arpt_entry *e,
 673                                        struct xt_counters total[],
 674                                        unsigned int *i)
 675 {
 676         SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
 677
 678         (*i)++;
 679         return 0;
 680 }
 681
 682 static void get_counters(const struct xt_table_info *t,
 683                          struct xt_counters counters[])
 684 {
 685         unsigned int cpu;
 686         unsigned int i;
 687         unsigned int curcpu;
 688
 689         /* Instead of clearing (by a previous call to memset())
 690          * the counters and using adds, we set the counters
 691          * with data used by 'current' CPU
 692          * We dont care about preemption here.
 693          */
 694         curcpu = raw_smp_processor_id();
 695
 696         i = 0;
 697         ARPT_ENTRY_ITERATE(t->entries[curcpu],
 698                            t->size,
 699                            set_entry_to_counter,
 700                            counters,
 701                            &i);
 702
 703         for_each_possible_cpu(cpu) {
 704                 if (cpu == curcpu)
 705                         continue;
 706                 i = 0;
 707                 ARPT_ENTRY_ITERATE(t->entries[cpu],
 708                                    t->size,
 709                                    add_entry_to_counter,
 710                                    counters,
 711                                    &i);
 712         }
 713 }
 714
 715 static inline struct xt_counters *alloc_counters(struct xt_table *table)
 716 {
 717         unsigned int countersize;
 718         struct xt_counters *counters;
 719         const struct xt_table_info *private = table->private;
 720
 721         /* We need atomic snapshot of counters: rest doesn't change
 722          * (other than comefrom, which userspace doesn't care
 723          * about).
 724          */
 725         countersize = sizeof(struct xt_counters) * private->number;
 726         counters = vmalloc_node(countersize, numa_node_id());
 727
 728         if (counters == NULL)
 729                 return ERR_PTR(-ENOMEM);
 730
 731         /* First, sum counters... */
 732         write_lock_bh(&table->lock);
 733         get_counters(private, counters);
 734         write_unlock_bh(&table->lock);
 735
 736         return counters;
 737 }
 738
 739 static int copy_entries_to_user(unsigned int total_size,
 740                                 struct xt_table *table,
 741                                 void __user *userptr)
 742 {
 743         unsigned int off, num;
 744         struct arpt_entry *e;
 745         struct xt_counters *counters;
 746         struct xt_table_info *private = table->private;
 747         int ret = 0;
 748         void *loc_cpu_entry;
 749
 750         counters = alloc_counters(table);
 751         if (IS_ERR(counters))
 752                 return PTR_ERR(counters);
 753
 754         loc_cpu_entry = private->entries[raw_smp_processor_id()];
 755         /* ... then copy entire thing ... */
 756         if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
 757                 ret = -EFAULT;
 758                 goto free_counters;
 759         }
 760
 761         /* FIXME: use iterator macros --RR */
 762         /* ... then go back and fix counters and names */
 763         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
 764                 struct arpt_entry_target *t;
 765
 766                 e = (struct arpt_entry *)(loc_cpu_entry + off);
 767                 if (copy_to_user(userptr + off
 768                                  + offsetof(struct arpt_entry, counters),
 769                                  &counters[num],
 770                                  sizeof(counters[num])) != 0) {
 771                         ret = -EFAULT;
 772                         goto free_counters;
 773                 }
 774
 775                 t = arpt_get_target(e);
 776                 if (copy_to_user(userptr + off + e->target_offset
 777                                  + offsetof(struct arpt_entry_target,
 778                                             u.user.name),
 779                                  t->u.kernel.target->name,
 780                                  strlen(t->u.kernel.target->name)+1) != 0) {
 781                         ret = -EFAULT;
 782                         goto free_counters;
 783                 }
 784         }
 785
 786  free_counters:
 787         vfree(counters);
 788         return ret;
 789 }
 790
 791 #ifdef CONFIG_COMPAT
 792 static void compat_standard_from_user(void *dst, void *src)
 793 {
 794         int v = *(compat_int_t *)src;
 795
 796         if (v > 0)
 797                 v += xt_compat_calc_jump(NFPROTO_ARP, v);
 798         memcpy(dst, &v, sizeof(v));
 799 }
 800
 801 static int compat_standard_to_user(void __user *dst, void *src)
 802 {
 803         compat_int_t cv = *(int *)src;
 804
 805         if (cv > 0)
 806                 cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
 807         return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
 808 }
 809
 810 static int compat_calc_entry(struct arpt_entry *e,
 811                              const struct xt_table_info *info,
 812                              void *base, struct xt_table_info *newinfo)
 813 {
 814         struct arpt_entry_target *t;
 815         unsigned int entry_offset;
 816         int off, i, ret;
 817
 818         off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
 819         entry_offset = (void *)e - base;
 820
 821         t = arpt_get_target(e);
 822         off += xt_compat_target_offset(t->u.kernel.target);
 823         newinfo->size -= off;
 824         ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
 825         if (ret)
 826                 return ret;
 827
 828         for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
 829                 if (info->hook_entry[i] &&
 830                     (e < (struct arpt_entry *)(base + info->hook_entry[i])))
 831                         newinfo->hook_entry[i] -= off;
 832                 if (info->underflow[i] &&
 833                     (e < (struct arpt_entry *)(base + info->underflow[i])))
 834                         newinfo->underflow[i] -= off;
 835         }
 836         return 0;
 837 }
 838
 839 static int compat_table_info(const struct xt_table_info *info,
 840                              struct xt_table_info *newinfo)
 841 {
 842         void *loc_cpu_entry;
 843
 844         if (!newinfo || !info)
 845                 return -EINVAL;
 846
 847         /* we dont care about newinfo->entries[] */
 848         memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
 849         newinfo->initial_entries = 0;
 850         loc_cpu_entry = info->entries[raw_smp_processor_id()];
 851         return ARPT_ENTRY_ITERATE(loc_cpu_entry, info->size,
 852                                   compat_calc_entry, info, loc_cpu_entry,
 853                                   newinfo);
 854 }
 855 #endif
 856
 857 static int get_info(struct net *net, void __user *user, int *len, int compat)
 858 {
 859         char name[ARPT_TABLE_MAXNAMELEN];
 860         struct xt_table *t;
 861         int ret;
 862
 863         if (*len != sizeof(struct arpt_getinfo)) {
 864                 duprintf("length %u != %Zu\n", *len,
 865                          sizeof(struct arpt_getinfo));
 866                 return -EINVAL;
 867         }
 868
 869         if (copy_from_user(name, user, sizeof(name)) != 0)
 870                 return -EFAULT;
 871
 872         name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
 873 #ifdef CONFIG_COMPAT
 874         if (compat)
 875                 xt_compat_lock(NFPROTO_ARP);
 876 #endif
 877         t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
 878                                     "arptable_%s", name);
 879         if (t && !IS_ERR(t)) {
 880                 struct arpt_getinfo info;
 881                 const struct xt_table_info *private = t->private;
 882
 883 #ifdef CONFIG_COMPAT
 884                 if (compat) {
 885                         struct xt_table_info tmp;
 886                         ret = compat_table_info(private, &tmp);
 887                         xt_compat_flush_offsets(NFPROTO_ARP);
 888                         private = &tmp;
 889                 }
 890 #endif
 891                 info.valid_hooks = t->valid_hooks;
 892                 memcpy(info.hook_entry, private->hook_entry,
 893                        sizeof(info.hook_entry));
 894                 memcpy(info.underflow, private->underflow,
 895                        sizeof(info.underflow));
 896                 info.num_entries = private->number;
 897                 info.size = private->size;
 898                 strcpy(info.name, name);
 899
 900                 if (copy_to_user(user, &info, *len) != 0)
 901                         ret = -EFAULT;
 902                 else
 903                         ret = 0;
 904                 xt_table_unlock(t);
 905                 module_put(t->me);
 906         } else
 907                 ret = t ? PTR_ERR(t) : -ENOENT;
 908 #ifdef CONFIG_COMPAT
 909         if (compat)
 910                 xt_compat_unlock(NFPROTO_ARP);
 911 #endif
 912         return ret;
 913 }
 914
 915 static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
 916                        int *len)
 917 {
 918         int ret;
 919         struct arpt_get_entries get;
 920         struct xt_table *t;
 921
 922         if (*len < sizeof(get)) {
 923                 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
 924                 return -EINVAL;
 925         }
 926         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
 927                 return -EFAULT;
 928         if (*len != sizeof(struct arpt_get_entries) + get.size) {
 929                 duprintf("get_entries: %u != %Zu\n", *len,
 930                          sizeof(struct arpt_get_entries) + get.size);
 931                 return -EINVAL;
 932         }
 933
 934         t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
 935         if (t && !IS_ERR(t)) {
 936                 const struct xt_table_info *private = t->private;
 937
 938                 duprintf("t->private->number = %u\n",
 939                          private->number);
 940                 if (get.size == private->size)
 941                         ret = copy_entries_to_user(private->size,
 942                                                    t, uptr->entrytable);
 943                 else {
 944                         duprintf("get_entries: I've got %u not %u!\n",
 945                                  private->size, get.size);
 946                         ret = -EAGAIN;
 947                 }
 948                 module_put(t->me);
 949                 xt_table_unlock(t);
 950         } else
 951                 ret = t ? PTR_ERR(t) : -ENOENT;
 952
 953         return ret;
 954 }
 955
 956 static int __do_replace(struct net *net, const char *name,
 957                         unsigned int valid_hooks,
 958                         struct xt_table_info *newinfo,
 959                         unsigned int num_counters,
 960                         void __user *counters_ptr)
 961 {
 962         int ret;
 963         struct xt_table *t;
 964         struct xt_table_info *oldinfo;
 965         struct xt_counters *counters;
 966         void *loc_cpu_old_entry;
 967
 968         ret = 0;
 969         counters = vmalloc_node(num_counters * sizeof(struct xt_counters),
 970                                 numa_node_id());
 971         if (!counters) {
 972                 ret = -ENOMEM;
 973                 goto out;
 974         }
 975
 976         t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
 977                                     "arptable_%s", name);
 978         if (!t || IS_ERR(t)) {
 979                 ret = t ? PTR_ERR(t) : -ENOENT;
 980                 goto free_newinfo_counters_untrans;
 981         }
 982
 983         /* You lied! */
 984         if (valid_hooks != t->valid_hooks) {
 985                 duprintf("Valid hook crap: %08X vs %08X\n",
 986                          valid_hooks, t->valid_hooks);
 987                 ret = -EINVAL;
 988                 goto put_module;
 989         }
 990
 991         oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
 992         if (!oldinfo)
 993                 goto put_module;
 994
 995         /* Update module usage count based on number of rules */
 996         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
 997                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
 998         if ((oldinfo->number > oldinfo->initial_entries) ||
 999             (newinfo->number <= oldinfo->initial_entries))
1000                 module_put(t->me);
1001         if ((oldinfo->number > oldinfo->initial_entries) &&
1002             (newinfo->number <= oldinfo->initial_entries))
1003                 module_put(t->me);
1004
1005         /* Get the old counters. */
1006         get_counters(oldinfo, counters);
1007         /* Decrease module usage counts and free resource */
1008         loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1009         ARPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,
1010                            NULL);
1011
1012         xt_free_table_info(oldinfo);
1013         if (copy_to_user(counters_ptr, counters,
1014                          sizeof(struct xt_counters) * num_counters) != 0)
1015                 ret = -EFAULT;
1016         vfree(counters);
1017         xt_table_unlock(t);
1018         return ret;
1019
1020  put_module:
1021         module_put(t->me);
1022         xt_table_unlock(t);
1023  free_newinfo_counters_untrans:
1024         vfree(counters);
1025  out:
1026         return ret;
1027 }
1028
1029 static int do_replace(struct net *net, void __user *user, unsigned int len)
1030 {
1031         int ret;
1032         struct arpt_replace tmp;
1033         struct xt_table_info *newinfo;
1034         void *loc_cpu_entry;
1035
1036         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1037                 return -EFAULT;
1038
1039         /* overflow check */
1040         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1041                 return -ENOMEM;
1042
1043         newinfo = xt_alloc_table_info(tmp.size);
1044         if (!newinfo)
1045                 return -ENOMEM;
1046
1047         /* choose the copy that is on our node/cpu */
1048         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1049         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1050                            tmp.size) != 0) {
1051                 ret = -EFAULT;
1052                 goto free_newinfo;
1053         }
1054
1055         ret = translate_table(tmp.name, tmp.valid_hooks,
1056                               newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
1057                               tmp.hook_entry, tmp.underflow);
1058         if (ret != 0)
1059                 goto free_newinfo;
1060
1061         duprintf("arp_tables: Translated table\n");
1062
1063         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1064                            tmp.num_counters, tmp.counters);
1065         if (ret)
1066                 goto free_newinfo_untrans;
1067         return 0;
1068
1069  free_newinfo_untrans:
1070         ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
1071  free_newinfo:
1072         xt_free_table_info(newinfo);
1073         return ret;
1074 }
1075
1076 /* We're lazy, and add to the first CPU; overflow works its fey magic
1077  * and everything is OK.
1078  */
1079 static inline int add_counter_to_entry(struct arpt_entry *e,
1080                                        const struct xt_counters addme[],
1081                                        unsigned int *i)
1082 {
1083
1084         ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
1085
1086         (*i)++;
1087         return 0;
1088 }
1089
1090 static int do_add_counters(struct net *net, void __user *user, unsigned int len,
1091                            int compat)
1092 {
1093         unsigned int i;
1094         struct xt_counters_info tmp;
1095         struct xt_counters *paddc;
1096         unsigned int num_counters;
1097         const char *name;
1098         int size;
1099         void *ptmp;
1100         struct xt_table *t;
1101         const struct xt_table_info *private;
1102         int ret = 0;
1103         void *loc_cpu_entry;
1104 #ifdef CONFIG_COMPAT
1105         struct compat_xt_counters_info compat_tmp;
1106
1107         if (compat) {
1108                 ptmp = &compat_tmp;
1109                 size = sizeof(struct compat_xt_counters_info);
1110         } else
1111 #endif
1112         {
1113                 ptmp = &tmp;
1114                 size = sizeof(struct xt_counters_info);
1115         }
1116
1117         if (copy_from_user(ptmp, user, size) != 0)
1118                 return -EFAULT;
1119
1120 #ifdef CONFIG_COMPAT
1121         if (compat) {
1122                 num_counters = compat_tmp.num_counters;
1123                 name = compat_tmp.name;
1124         } else
1125 #endif
1126         {
1127                 num_counters = tmp.num_counters;
1128                 name = tmp.name;
1129         }
1130
1131         if (len != size + num_counters * sizeof(struct xt_counters))
1132                 return -EINVAL;
1133
1134         paddc = vmalloc_node(len - size, numa_node_id());
1135         if (!paddc)
1136                 return -ENOMEM;
1137
1138         if (copy_from_user(paddc, user + size, len - size) != 0) {
1139                 ret = -EFAULT;
1140                 goto free;
1141         }
1142
1143         t = xt_find_table_lock(net, NFPROTO_ARP, name);
1144         if (!t || IS_ERR(t)) {
1145                 ret = t ? PTR_ERR(t) : -ENOENT;
1146                 goto free;
1147         }
1148
1149         write_lock_bh(&t->lock);
1150         private = t->private;
1151         if (private->number != num_counters) {
1152                 ret = -EINVAL;
1153                 goto unlock_up_free;
1154         }
1155
1156         i = 0;
1157         /* Choose the copy that is on our node */
1158         loc_cpu_entry = private->entries[smp_processor_id()];
1159         ARPT_ENTRY_ITERATE(loc_cpu_entry,
1160                            private->size,
1161                            add_counter_to_entry,
1162                            paddc,
1163                            &i);
1164  unlock_up_free:
1165         write_unlock_bh(&t->lock);
1166         xt_table_unlock(t);
1167         module_put(t->me);
1168  free:
1169         vfree(paddc);
1170
1171         return ret;
1172 }
1173
1174 #ifdef CONFIG_COMPAT
1175 static inline int
1176 compat_release_entry(struct compat_arpt_entry *e, unsigned int *i)
1177 {
1178         struct arpt_entry_target *t;
1179
1180         if (i && (*i)-- == 0)
1181                 return 1;
1182
1183         t = compat_arpt_get_target(e);
1184         module_put(t->u.kernel.target->me);
1185         return 0;
1186 }
1187
1188 static inline int
1189 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
1190                                   struct xt_table_info *newinfo,
1191                                   unsigned int *size,
1192                                   unsigned char *base,
1193                                   unsigned char *limit,
1194                                   unsigned int *hook_entries,
1195                                   unsigned int *underflows,
1196                                   unsigned int *i,
1197                                   const char *name)
1198 {
1199         struct arpt_entry_target *t;
1200         struct xt_target *target;
1201         unsigned int entry_offset;
1202         int ret, off, h;
1203
1204         duprintf("check_compat_entry_size_and_hooks %p\n", e);
1205         if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0
1206             || (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
1207                 duprintf("Bad offset %p, limit = %p\n", e, limit);
1208                 return -EINVAL;
1209         }
1210
1211         if (e->next_offset < sizeof(struct compat_arpt_entry) +
1212                              sizeof(struct compat_xt_entry_target)) {
1213                 duprintf("checking: element %p size %u\n",
1214                          e, e->next_offset);
1215                 return -EINVAL;
1216         }
1217
1218         /* For purposes of check_entry casting the compat entry is fine */
1219         ret = check_entry((struct arpt_entry *)e, name);
1220         if (ret)
1221                 return ret;
1222
1223         off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1224         entry_offset = (void *)e - (void *)base;
1225
1226         t = compat_arpt_get_target(e);
1227         target = try_then_request_module(xt_find_target(NFPROTO_ARP,
1228                                                         t->u.user.name,
1229                                                         t->u.user.revision),
1230                                          "arpt_%s", t->u.user.name);
1231         if (IS_ERR(target) || !target) {
1232                 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1233                          t->u.user.name);
1234                 ret = target ? PTR_ERR(target) : -ENOENT;
1235                 goto out;
1236         }
1237         t->u.kernel.target = target;
1238
1239         off += xt_compat_target_offset(target);
1240         *size += off;
1241         ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
1242         if (ret)
1243                 goto release_target;
1244
1245         /* Check hooks & underflows */
1246         for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1247                 if ((unsigned char *)e - base == hook_entries[h])
1248                         newinfo->hook_entry[h] = hook_entries[h];
1249                 if ((unsigned char *)e - base == underflows[h])
1250                         newinfo->underflow[h] = underflows[h];
1251         }
1252
1253         /* Clear counters and comefrom */
1254         memset(&e->counters, 0, sizeof(e->counters));
1255         e->comefrom = 0;
1256
1257         (*i)++;
1258         return 0;
1259
1260 release_target:
1261         module_put(t->u.kernel.target->me);
1262 out:
1263         return ret;
1264 }
1265
1266 static int
1267 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
1268                             unsigned int *size, const char *name,
1269                             struct xt_table_info *newinfo, unsigned char *base)
1270 {
1271         struct arpt_entry_target *t;
1272         struct xt_target *target;
1273         struct arpt_entry *de;
1274         unsigned int origsize;
1275         int ret, h;
1276
1277         ret = 0;
1278         origsize = *size;
1279         de = (struct arpt_entry *)*dstptr;
1280         memcpy(de, e, sizeof(struct arpt_entry));
1281         memcpy(&de->counters, &e->counters, sizeof(e->counters));
1282
1283         *dstptr += sizeof(struct arpt_entry);
1284         *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1285
1286         de->target_offset = e->target_offset - (origsize - *size);
1287         t = compat_arpt_get_target(e);
1288         target = t->u.kernel.target;
1289         xt_compat_target_from_user(t, dstptr, size);
1290
1291         de->next_offset = e->next_offset - (origsize - *size);
1292         for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1293                 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1294                         newinfo->hook_entry[h] -= origsize - *size;
1295                 if ((unsigned char *)de - base < newinfo->underflow[h])
1296                         newinfo->underflow[h] -= origsize - *size;
1297         }
1298         return ret;
1299 }
1300
1301 static inline int compat_check_entry(struct arpt_entry *e, const char *name,
1302                                      unsigned int *i)
1303 {
1304         int ret;
1305
1306         ret = check_target(e, name);
1307         if (ret)
1308                 return ret;
1309
1310         (*i)++;
1311         return 0;
1312 }
1313
1314 static int translate_compat_table(const char *name,
1315                                   unsigned int valid_hooks,
1316                                   struct xt_table_info **pinfo,
1317                                   void **pentry0,
1318                                   unsigned int total_size,
1319                                   unsigned int number,
1320                                   unsigned int *hook_entries,
1321                                   unsigned int *underflows)
1322 {
1323         unsigned int i, j;
1324         struct xt_table_info *newinfo, *info;
1325         void *pos, *entry0, *entry1;
1326         unsigned int size;
1327         int ret;
1328
1329         info = *pinfo;
1330         entry0 = *pentry0;
1331         size = total_size;
1332         info->number = number;
1333
1334         /* Init all hooks to impossible value. */
1335         for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1336                 info->hook_entry[i] = 0xFFFFFFFF;
1337                 info->underflow[i] = 0xFFFFFFFF;
1338         }
1339
1340         duprintf("translate_compat_table: size %u\n", info->size);
1341         j = 0;
1342         xt_compat_lock(NFPROTO_ARP);
1343         /* Walk through entries, checking offsets. */
1344         ret = COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size,
1345                                         check_compat_entry_size_and_hooks,
1346                                         info, &size, entry0,
1347                                         entry0 + total_size,
1348                                         hook_entries, underflows, &j, name);
1349         if (ret != 0)
1350                 goto out_unlock;
1351
1352         ret = -EINVAL;
1353         if (j != number) {
1354                 duprintf("translate_compat_table: %u not %u entries\n",
1355                          j, number);
1356                 goto out_unlock;
1357         }
1358
1359         /* Check hooks all assigned */
1360         for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1361                 /* Only hooks which are valid */
1362                 if (!(valid_hooks & (1 << i)))
1363                         continue;
1364                 if (info->hook_entry[i] == 0xFFFFFFFF) {
1365                         duprintf("Invalid hook entry %u %u\n",
1366                                  i, hook_entries[i]);
1367                         goto out_unlock;
1368                 }
1369                 if (info->underflow[i] == 0xFFFFFFFF) {
1370                         duprintf("Invalid underflow %u %u\n",
1371                                  i, underflows[i]);
1372                         goto out_unlock;
1373                 }
1374         }
1375
1376         ret = -ENOMEM;
1377         newinfo = xt_alloc_table_info(size);
1378         if (!newinfo)
1379                 goto out_unlock;
1380
1381         newinfo->number = number;
1382         for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1383                 newinfo->hook_entry[i] = info->hook_entry[i];
1384                 newinfo->underflow[i] = info->underflow[i];
1385         }
1386         entry1 = newinfo->entries[raw_smp_processor_id()];
1387         pos = entry1;
1388         size = total_size;
1389         ret = COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size,
1390                                         compat_copy_entry_from_user,
1391                                         &pos, &size, name, newinfo, entry1);
1392         xt_compat_flush_offsets(NFPROTO_ARP);
1393         xt_compat_unlock(NFPROTO_ARP);
1394         if (ret)
1395                 goto free_newinfo;
1396
1397         ret = -ELOOP;
1398         if (!mark_source_chains(newinfo, valid_hooks, entry1))
1399                 goto free_newinfo;
1400
1401         i = 0;
1402         ret = ARPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
1403                                  name, &i);
1404         if (ret) {
1405                 j -= i;
1406                 COMPAT_ARPT_ENTRY_ITERATE_CONTINUE(entry0, newinfo->size, i,
1407                                                    compat_release_entry, &j);
1408                 ARPT_ENTRY_ITERATE(entry1, newinfo->size, cleanup_entry, &i);
1409                 xt_free_table_info(newinfo);
1410                 return ret;
1411         }
1412
1413         /* And one copy for every other CPU */
1414         for_each_possible_cpu(i)
1415                 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1416                         memcpy(newinfo->entries[i], entry1, newinfo->size);
1417
1418         *pinfo = newinfo;
1419         *pentry0 = entry1;
1420         xt_free_table_info(info);
1421         return 0;
1422
1423 free_newinfo:
1424         xt_free_table_info(newinfo);
1425 out:
1426         COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
1427         return ret;
1428 out_unlock:
1429         xt_compat_flush_offsets(NFPROTO_ARP);
1430         xt_compat_unlock(NFPROTO_ARP);
1431         goto out;
1432 }
1433
1434 struct compat_arpt_replace {
1435         char                            name[ARPT_TABLE_MAXNAMELEN];
1436         u32                             valid_hooks;
1437         u32                             num_entries;
1438         u32                             size;
1439         u32                             hook_entry[NF_ARP_NUMHOOKS];
1440         u32                             underflow[NF_ARP_NUMHOOKS];
1441         u32                             num_counters;
1442         compat_uptr_t                   counters;
1443         struct compat_arpt_entry        entries[0];
1444 };
1445
1446 static int compat_do_replace(struct net *net, void __user *user,
1447                              unsigned int len)
1448 {
1449         int ret;
1450         struct compat_arpt_replace tmp;
1451         struct xt_table_info *newinfo;
1452         void *loc_cpu_entry;
1453
1454         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1455                 return -EFAULT;
1456
1457         /* overflow check */
1458         if (tmp.size >= INT_MAX / num_possible_cpus())
1459                 return -ENOMEM;
1460         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1461                 return -ENOMEM;
1462
1463         newinfo = xt_alloc_table_info(tmp.size);
1464         if (!newinfo)
1465                 return -ENOMEM;
1466
1467         /* choose the copy that is on our node/cpu */
1468         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1469         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
1470                 ret = -EFAULT;
1471                 goto free_newinfo;
1472         }
1473
1474         ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1475                                      &newinfo, &loc_cpu_entry, tmp.size,
1476                                      tmp.num_entries, tmp.hook_entry,
1477                                      tmp.underflow);
1478         if (ret != 0)
1479                 goto free_newinfo;
1480
1481         duprintf("compat_do_replace: Translated table\n");
1482
1483         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1484                            tmp.num_counters, compat_ptr(tmp.counters));
1485         if (ret)
1486                 goto free_newinfo_untrans;
1487         return 0;
1488
1489  free_newinfo_untrans:
1490         ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
1491  free_newinfo:
1492         xt_free_table_info(newinfo);
1493         return ret;
1494 }
1495
1496 static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
1497                                   unsigned int len)
1498 {
1499         int ret;
1500
1501         if (!capable(CAP_NET_ADMIN))
1502                 return -EPERM;
1503
1504         switch (cmd) {
1505         case ARPT_SO_SET_REPLACE:
1506                 ret = compat_do_replace(sock_net(sk), user, len);
1507                 break;
1508
1509         case ARPT_SO_SET_ADD_COUNTERS:
1510                 ret = do_add_counters(sock_net(sk), user, len, 1);
1511                 break;
1512
1513         default:
1514                 duprintf("do_arpt_set_ctl:  unknown request %i\n", cmd);
1515                 ret = -EINVAL;
1516         }
1517
1518         return ret;
1519 }
1520
1521 static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
1522                                      compat_uint_t *size,
1523                                      struct xt_counters *counters,
1524                                      unsigned int *i)
1525 {
1526         struct arpt_entry_target *t;
1527         struct compat_arpt_entry __user *ce;
1528         u_int16_t target_offset, next_offset;
1529         compat_uint_t origsize;
1530         int ret;
1531
1532         ret = -EFAULT;
1533         origsize = *size;
1534         ce = (struct compat_arpt_entry __user *)*dstptr;
1535         if (copy_to_user(ce, e, sizeof(struct arpt_entry)))
1536                 goto out;
1537
1538         if (copy_to_user(&ce->counters, &counters[*i], sizeof(counters[*i])))
1539                 goto out;
1540
1541         *dstptr += sizeof(struct compat_arpt_entry);
1542         *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1543
1544         target_offset = e->target_offset - (origsize - *size);
1545
1546         t = arpt_get_target(e);
1547         ret = xt_compat_target_to_user(t, dstptr, size);
1548         if (ret)
1549                 goto out;
1550         ret = -EFAULT;
1551         next_offset = e->next_offset - (origsize - *size);
1552         if (put_user(target_offset, &ce->target_offset))
1553                 goto out;
1554         if (put_user(next_offset, &ce->next_offset))
1555                 goto out;
1556
1557         (*i)++;
1558         return 0;
1559 out:
1560         return ret;
1561 }
1562
1563 static int compat_copy_entries_to_user(unsigned int total_size,
1564                                        struct xt_table *table,
1565                                        void __user *userptr)
1566 {
1567         struct xt_counters *counters;
1568         const struct xt_table_info *private = table->private;
1569         void __user *pos;
1570         unsigned int size;
1571         int ret = 0;
1572         void *loc_cpu_entry;
1573         unsigned int i = 0;
1574
1575         counters = alloc_counters(table);
1576         if (IS_ERR(counters))
1577                 return PTR_ERR(counters);
1578
1579         /* choose the copy on our node/cpu */
1580         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1581         pos = userptr;
1582         size = total_size;
1583         ret = ARPT_ENTRY_ITERATE(loc_cpu_entry, total_size,
1584                                  compat_copy_entry_to_user,
1585                                  &pos, &size, counters, &i);
1586         vfree(counters);
1587         return ret;
1588 }
1589
1590 struct compat_arpt_get_entries {
1591         char name[ARPT_TABLE_MAXNAMELEN];
1592         compat_uint_t size;
1593         struct compat_arpt_entry entrytable[0];
1594 };
1595
1596 static int compat_get_entries(struct net *net,
1597                               struct compat_arpt_get_entries __user *uptr,
1598                               int *len)
1599 {
1600         int ret;
1601         struct compat_arpt_get_entries get;
1602         struct xt_table *t;
1603
1604         if (*len < sizeof(get)) {
1605                 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1606                 return -EINVAL;
1607         }
1608         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1609                 return -EFAULT;
1610         if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
1611                 duprintf("compat_get_entries: %u != %zu\n",
1612                          *len, sizeof(get) + get.size);
1613                 return -EINVAL;
1614         }
1615
1616         xt_compat_lock(NFPROTO_ARP);
1617         t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
1618         if (t && !IS_ERR(t)) {
1619                 const struct xt_table_info *private = t->private;
1620                 struct xt_table_info info;
1621
1622                 duprintf("t->private->number = %u\n", private->number);
1623                 ret = compat_table_info(private, &info);
1624                 if (!ret && get.size == info.size) {
1625                         ret = compat_copy_entries_to_user(private->size,
1626                                                           t, uptr->entrytable);
1627                 } else if (!ret) {
1628                         duprintf("compat_get_entries: I've got %u not %u!\n",
1629                                  private->size, get.size);
1630                         ret = -EAGAIN;
1631                 }
1632                 xt_compat_flush_offsets(NFPROTO_ARP);
1633                 module_put(t->me);
1634                 xt_table_unlock(t);
1635         } else
1636                 ret = t ? PTR_ERR(t) : -ENOENT;
1637
1638         xt_compat_unlock(NFPROTO_ARP);
1639         return ret;
1640 }
1641
1642 static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
1643
1644 static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
1645                                   int *len)
1646 {
1647         int ret;
1648
1649         if (!capable(CAP_NET_ADMIN))
1650                 return -EPERM;
1651
1652         switch (cmd) {
1653         case ARPT_SO_GET_INFO:
1654                 ret = get_info(sock_net(sk), user, len, 1);
1655                 break;
1656         case ARPT_SO_GET_ENTRIES:
1657                 ret = compat_get_entries(sock_net(sk), user, len);
1658                 break;
1659         default:
1660                 ret = do_arpt_get_ctl(sk, cmd, user, len);
1661         }
1662         return ret;
1663 }
1664 #endif
1665
1666 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1667 {
1668         int ret;
1669
1670         if (!capable(CAP_NET_ADMIN))
1671                 return -EPERM;
1672
1673         switch (cmd) {
1674         case ARPT_SO_SET_REPLACE:
1675                 ret = do_replace(sock_net(sk), user, len);
1676                 break;
1677
1678         case ARPT_SO_SET_ADD_COUNTERS:
1679                 ret = do_add_counters(sock_net(sk), user, len, 0);
1680                 break;
1681
1682         default:
1683                 duprintf("do_arpt_set_ctl:  unknown request %i\n", cmd);
1684                 ret = -EINVAL;
1685         }
1686
1687         return ret;
1688 }
1689
1690 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1691 {
1692         int ret;
1693
1694         if (!capable(CAP_NET_ADMIN))
1695                 return -EPERM;
1696
1697         switch (cmd) {
1698         case ARPT_SO_GET_INFO:
1699                 ret = get_info(sock_net(sk), user, len, 0);
1700                 break;
1701
1702         case ARPT_SO_GET_ENTRIES:
1703                 ret = get_entries(sock_net(sk), user, len);
1704                 break;
1705
1706         case ARPT_SO_GET_REVISION_TARGET: {
1707                 struct xt_get_revision rev;
1708
1709                 if (*len != sizeof(rev)) {
1710                         ret = -EINVAL;
1711                         break;
1712                 }
1713                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1714                         ret = -EFAULT;
1715                         break;
1716                 }
1717
1718                 try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
1719                                                          rev.revision, 1, &ret),
1720                                         "arpt_%s", rev.name);
1721                 break;
1722         }
1723
1724         default:
1725                 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1726                 ret = -EINVAL;
1727         }
1728
1729         return ret;
1730 }
1731
1732 struct xt_table *arpt_register_table(struct net *net, struct xt_table *table,
1733                                      const struct arpt_replace *repl)
1734 {
1735         int ret;
1736         struct xt_table_info *newinfo;
1737         struct xt_table_info bootstrap
1738                 = { 0, 0, 0, { 0 }, { 0 }, { } };
1739         void *loc_cpu_entry;
1740         struct xt_table *new_table;
1741
1742         newinfo = xt_alloc_table_info(repl->size);
1743         if (!newinfo) {
1744                 ret = -ENOMEM;
1745                 goto out;
1746         }
1747
1748         /* choose the copy on our node/cpu */
1749         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1750         memcpy(loc_cpu_entry, repl->entries, repl->size);
1751
1752         ret = translate_table(table->name, table->valid_hooks,
1753                               newinfo, loc_cpu_entry, repl->size,
1754                               repl->num_entries,
1755                               repl->hook_entry,
1756                               repl->underflow);
1757
1758         duprintf("arpt_register_table: translate table gives %d\n", ret);
1759         if (ret != 0)
1760                 goto out_free;
1761
1762         new_table = xt_register_table(net, table, &bootstrap, newinfo);
1763         if (IS_ERR(new_table)) {
1764                 ret = PTR_ERR(new_table);
1765                 goto out_free;
1766         }
1767         return new_table;
1768
1769 out_free:
1770         xt_free_table_info(newinfo);
1771 out:
1772         return ERR_PTR(ret);
1773 }
1774
1775 void arpt_unregister_table(struct xt_table *table)
1776 {
1777         struct xt_table_info *private;
1778         void *loc_cpu_entry;
1779         struct module *table_owner = table->me;
1780
1781         private = xt_unregister_table(table);
1782
1783         /* Decrease module usage counts and free resources */
1784         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1785         ARPT_ENTRY_ITERATE(loc_cpu_entry, private->size,
1786                            cleanup_entry, NULL);
1787         if (private->number > private->initial_entries)
1788                 module_put(table_owner);
1789         xt_free_table_info(private);
1790 }
1791
1792 /* The built-in targets: standard (NULL) and error. */
1793 static struct xt_target arpt_standard_target __read_mostly = {
1794         .name           = ARPT_STANDARD_TARGET,
1795         .targetsize     = sizeof(int),
1796         .family         = NFPROTO_ARP,
1797 #ifdef CONFIG_COMPAT
1798         .compatsize     = sizeof(compat_int_t),
1799         .compat_from_user = compat_standard_from_user,
1800         .compat_to_user = compat_standard_to_user,
1801 #endif
1802 };
1803
1804 static struct xt_target arpt_error_target __read_mostly = {
1805         .name           = ARPT_ERROR_TARGET,
1806         .target         = arpt_error,
1807         .targetsize     = ARPT_FUNCTION_MAXNAMELEN,
1808         .family         = NFPROTO_ARP,
1809 };
1810
1811 static struct nf_sockopt_ops arpt_sockopts = {
1812         .pf             = PF_INET,
1813         .set_optmin     = ARPT_BASE_CTL,
1814         .set_optmax     = ARPT_SO_SET_MAX+1,
1815         .set            = do_arpt_set_ctl,
1816 #ifdef CONFIG_COMPAT
1817         .compat_set     = compat_do_arpt_set_ctl,
1818 #endif
1819         .get_optmin     = ARPT_BASE_CTL,
1820         .get_optmax     = ARPT_SO_GET_MAX+1,
1821         .get            = do_arpt_get_ctl,
1822 #ifdef CONFIG_COMPAT
1823         .compat_get     = compat_do_arpt_get_ctl,
1824 #endif
1825         .owner          = THIS_MODULE,
1826 };
1827
1828 static int __net_init arp_tables_net_init(struct net *net)
1829 {
1830         return xt_proto_init(net, NFPROTO_ARP);
1831 }
1832
1833 static void __net_exit arp_tables_net_exit(struct net *net)
1834 {
1835         xt_proto_fini(net, NFPROTO_ARP);
1836 }
1837
1838 static struct pernet_operations arp_tables_net_ops = {
1839         .init = arp_tables_net_init,
1840         .exit = arp_tables_net_exit,
1841 };
1842
1843 static int __init arp_tables_init(void)
1844 {
1845         int ret;
1846
1847         ret = register_pernet_subsys(&arp_tables_net_ops);
1848         if (ret < 0)
1849                 goto err1;
1850
1851         /* Noone else will be downing sem now, so we won't sleep */
1852         ret = xt_register_target(&arpt_standard_target);
1853         if (ret < 0)
1854                 goto err2;
1855         ret = xt_register_target(&arpt_error_target);
1856         if (ret < 0)
1857                 goto err3;
1858
1859         /* Register setsockopt */
1860         ret = nf_register_sockopt(&arpt_sockopts);
1861         if (ret < 0)
1862                 goto err4;
1863
1864         printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
1865         return 0;
1866
1867 err4:
1868         xt_unregister_target(&arpt_error_target);
1869 err3:
1870         xt_unregister_target(&arpt_standard_target);
1871 err2:
1872         unregister_pernet_subsys(&arp_tables_net_ops);
1873 err1:
1874         return ret;
1875 }
1876
1877 static void __exit arp_tables_fini(void)
1878 {
1879         nf_unregister_sockopt(&arpt_sockopts);
1880         xt_unregister_target(&arpt_error_target);
1881         xt_unregister_target(&arpt_standard_target);
1882         unregister_pernet_subsys(&arp_tables_net_ops);
1883 }
1884
1885 EXPORT_SYMBOL(arpt_register_table);
1886 EXPORT_SYMBOL(arpt_unregister_table);
1887 EXPORT_SYMBOL(arpt_do_table);
1888
1889 module_init(arp_tables_init);
1890 module_exit(arp_tables_fini);