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