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