net/ipv4/netfilter/arp_tables.c

   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/config.h>
  13 #include <linux/kernel.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/netdevice.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
  23 #include <asm/uaccess.h>
  24 #include <asm/semaphore.h>
  25
  26 #include <linux/netfilter_arp/arp_tables.h>
  27
  28 MODULE_LICENSE("GPL");
  29 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
  30 MODULE_DESCRIPTION("arptables core");
  31
  32 /*#define DEBUG_ARP_TABLES*/
  33 /*#define DEBUG_ARP_TABLES_USER*/
  34
  35 #ifdef DEBUG_ARP_TABLES
  36 #define dprintf(format, args...)  printk(format , ## args)
  37 #else
  38 #define dprintf(format, args...)
  39 #endif
  40
  41 #ifdef DEBUG_ARP_TABLES_USER
  42 #define duprintf(format, args...) printk(format , ## args)
  43 #else
  44 #define duprintf(format, args...)
  45 #endif
  46
  47 #ifdef CONFIG_NETFILTER_DEBUG
  48 #define ARP_NF_ASSERT(x)                                        \
  49 do {                                                            \
  50         if (!(x))                                               \
  51                 printk("ARP_NF_ASSERT: %s:%s:%u\n",             \
  52                        __FUNCTION__, __FILE__, __LINE__);       \
  53 } while(0)
  54 #else
  55 #define ARP_NF_ASSERT(x)
  56 #endif
  57 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
  58
  59 static DECLARE_MUTEX(arpt_mutex);
  60
  61 #define ASSERT_READ_LOCK(x) ARP_NF_ASSERT(down_trylock(&arpt_mutex) != 0)
  62 #define ASSERT_WRITE_LOCK(x) ARP_NF_ASSERT(down_trylock(&arpt_mutex) != 0)
  63 #include <linux/netfilter_ipv4/listhelp.h>
  64
  65 struct arpt_table_info {
  66         unsigned int size;
  67         unsigned int number;
  68         unsigned int initial_entries;
  69         unsigned int hook_entry[NF_ARP_NUMHOOKS];
  70         unsigned int underflow[NF_ARP_NUMHOOKS];
  71         char entries[0] __attribute__((aligned(SMP_CACHE_BYTES)));
  72 };
  73
  74 static LIST_HEAD(arpt_target);
  75 static LIST_HEAD(arpt_tables);
  76 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
  77
  78 #ifdef CONFIG_SMP
  79 #define TABLE_OFFSET(t,p) (SMP_ALIGN((t)->size)*(p))
  80 #else
  81 #define TABLE_OFFSET(t,p) 0
  82 #endif
  83
  84 static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
  85                                       char *hdr_addr, int len)
  86 {
  87         int i, ret;
  88
  89         if (len > ARPT_DEV_ADDR_LEN_MAX)
  90                 len = ARPT_DEV_ADDR_LEN_MAX;
  91
  92         ret = 0;
  93         for (i = 0; i < len; i++)
  94                 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
  95
  96         return (ret != 0);
  97 }
  98
  99 /* Returns whether packet matches rule or not. */
 100 static inline int arp_packet_match(const struct arphdr *arphdr,
 101                                    struct net_device *dev,
 102                                    const char *indev,
 103                                    const char *outdev,
 104                                    const struct arpt_arp *arpinfo)
 105 {
 106         char *arpptr = (char *)(arphdr + 1);
 107         char *src_devaddr, *tgt_devaddr;
 108         u32 src_ipaddr, tgt_ipaddr;
 109         int i, ret;
 110
 111 #define FWINV(bool,invflg) ((bool) ^ !!(arpinfo->invflags & invflg))
 112
 113         if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
 114                   ARPT_INV_ARPOP)) {
 115                 dprintf("ARP operation field mismatch.\n");
 116                 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
 117                         arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
 118                 return 0;
 119         }
 120
 121         if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
 122                   ARPT_INV_ARPHRD)) {
 123                 dprintf("ARP hardware address format mismatch.\n");
 124                 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
 125                         arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
 126                 return 0;
 127         }
 128
 129         if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
 130                   ARPT_INV_ARPPRO)) {
 131                 dprintf("ARP protocol address format mismatch.\n");
 132                 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
 133                         arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
 134                 return 0;
 135         }
 136
 137         if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
 138                   ARPT_INV_ARPHLN)) {
 139                 dprintf("ARP hardware address length mismatch.\n");
 140                 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
 141                         arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
 142                 return 0;
 143         }
 144
 145         src_devaddr = arpptr;
 146         arpptr += dev->addr_len;
 147         memcpy(&src_ipaddr, arpptr, sizeof(u32));
 148         arpptr += sizeof(u32);
 149         tgt_devaddr = arpptr;
 150         arpptr += dev->addr_len;
 151         memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
 152
 153         if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
 154                   ARPT_INV_SRCDEVADDR) ||
 155             FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
 156                   ARPT_INV_TGTDEVADDR)) {
 157                 dprintf("Source or target device address mismatch.\n");
 158
 159                 return 0;
 160         }
 161
 162         if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
 163                   ARPT_INV_SRCIP) ||
 164             FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
 165                   ARPT_INV_TGTIP)) {
 166                 dprintf("Source or target IP address mismatch.\n");
 167
 168                 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
 169                         NIPQUAD(src_ipaddr),
 170                         NIPQUAD(arpinfo->smsk.s_addr),
 171                         NIPQUAD(arpinfo->src.s_addr),
 172                         arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
 173                 dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
 174                         NIPQUAD(tgt_ipaddr),
 175                         NIPQUAD(arpinfo->tmsk.s_addr),
 176                         NIPQUAD(arpinfo->tgt.s_addr),
 177                         arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
 178                 return 0;
 179         }
 180
 181         /* Look for ifname matches.  */
 182         for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
 183                 ret |= (indev[i] ^ arpinfo->iniface[i])
 184                         & arpinfo->iniface_mask[i];
 185         }
 186
 187         if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
 188                 dprintf("VIA in mismatch (%s vs %s).%s\n",
 189                         indev, arpinfo->iniface,
 190                         arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
 191                 return 0;
 192         }
 193
 194         for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
 195                 unsigned long odev;
 196                 memcpy(&odev, outdev + i*sizeof(unsigned long),
 197                        sizeof(unsigned long));
 198                 ret |= (odev
 199                         ^ ((const unsigned long *)arpinfo->outiface)[i])
 200                         & ((const unsigned long *)arpinfo->outiface_mask)[i];
 201         }
 202
 203         if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
 204                 dprintf("VIA out mismatch (%s vs %s).%s\n",
 205                         outdev, arpinfo->outiface,
 206                         arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
 207                 return 0;
 208         }
 209
 210         return 1;
 211 }
 212
 213 static inline int arp_checkentry(const struct arpt_arp *arp)
 214 {
 215         if (arp->flags & ~ARPT_F_MASK) {
 216                 duprintf("Unknown flag bits set: %08X\n",
 217                          arp->flags & ~ARPT_F_MASK);
 218                 return 0;
 219         }
 220         if (arp->invflags & ~ARPT_INV_MASK) {
 221                 duprintf("Unknown invflag bits set: %08X\n",
 222                          arp->invflags & ~ARPT_INV_MASK);
 223                 return 0;
 224         }
 225
 226         return 1;
 227 }
 228
 229 static unsigned int arpt_error(struct sk_buff **pskb,
 230                                unsigned int hooknum,
 231                                const struct net_device *in,
 232                                const struct net_device *out,
 233                                const void *targinfo,
 234                                void *userinfo)
 235 {
 236         if (net_ratelimit())
 237                 printk("arp_tables: error: '%s'\n", (char *)targinfo);
 238
 239         return NF_DROP;
 240 }
 241
 242 static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
 243 {
 244         return (struct arpt_entry *)(base + offset);
 245 }
 246
 247 unsigned int arpt_do_table(struct sk_buff **pskb,
 248                            unsigned int hook,
 249                            const struct net_device *in,
 250                            const struct net_device *out,
 251                            struct arpt_table *table,
 252                            void *userdata)
 253 {
 254         static const char nulldevname[IFNAMSIZ];
 255         unsigned int verdict = NF_DROP;
 256         struct arphdr *arp;
 257         int hotdrop = 0;
 258         struct arpt_entry *e, *back;
 259         const char *indev, *outdev;
 260         void *table_base;
 261
 262         /* ARP header, plus 2 device addresses, plus 2 IP addresses.  */
 263         if (!pskb_may_pull((*pskb), (sizeof(struct arphdr) +
 264                                      (2 * (*pskb)->dev->addr_len) +
 265                                      (2 * sizeof(u32)))))
 266                 return NF_DROP;
 267
 268         indev = in ? in->name : nulldevname;
 269         outdev = out ? out->name : nulldevname;
 270
 271         read_lock_bh(&table->lock);
 272         table_base = (void *)table->private->entries
 273                 + TABLE_OFFSET(table->private,
 274                                smp_processor_id());
 275         e = get_entry(table_base, table->private->hook_entry[hook]);
 276         back = get_entry(table_base, table->private->underflow[hook]);
 277
 278         arp = (*pskb)->nh.arph;
 279         do {
 280                 if (arp_packet_match(arp, (*pskb)->dev, indev, outdev, &e->arp)) {
 281                         struct arpt_entry_target *t;
 282                         int hdr_len;
 283
 284                         hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
 285                                 (2 * (*pskb)->dev->addr_len);
 286                         ADD_COUNTER(e->counters, hdr_len, 1);
 287
 288                         t = arpt_get_target(e);
 289
 290                         /* Standard target? */
 291                         if (!t->u.kernel.target->target) {
 292                                 int v;
 293
 294                                 v = ((struct arpt_standard_target *)t)->verdict;
 295                                 if (v < 0) {
 296                                         /* Pop from stack? */
 297                                         if (v != ARPT_RETURN) {
 298                                                 verdict = (unsigned)(-v) - 1;
 299                                                 break;
 300                                         }
 301                                         e = back;
 302                                         back = get_entry(table_base,
 303                                                          back->comefrom);
 304                                         continue;
 305                                 }
 306                                 if (table_base + v
 307                                     != (void *)e + e->next_offset) {
 308                                         /* Save old back ptr in next entry */
 309                                         struct arpt_entry *next
 310                                                 = (void *)e + e->next_offset;
 311                                         next->comefrom =
 312                                                 (void *)back - table_base;
 313
 314                                         /* set back pointer to next entry */
 315                                         back = next;
 316                                 }
 317
 318                                 e = get_entry(table_base, v);
 319                         } else {
 320                                 /* Targets which reenter must return
 321                                  * abs. verdicts
 322                                  */
 323                                 verdict = t->u.kernel.target->target(pskb,
 324                                                                      hook,
 325                                                                      in, out,
 326                                                                      t->data,
 327                                                                      userdata);
 328
 329                                 /* Target might have changed stuff. */
 330                                 arp = (*pskb)->nh.arph;
 331
 332                                 if (verdict == ARPT_CONTINUE)
 333                                         e = (void *)e + e->next_offset;
 334                                 else
 335                                         /* Verdict */
 336                                         break;
 337                         }
 338                 } else {
 339                         e = (void *)e + e->next_offset;
 340                 }
 341         } while (!hotdrop);
 342         read_unlock_bh(&table->lock);
 343
 344         if (hotdrop)
 345                 return NF_DROP;
 346         else
 347                 return verdict;
 348 }
 349
 350 static inline void *find_inlist_lock_noload(struct list_head *head,
 351                                             const char *name,
 352                                             int *error,
 353                                             struct semaphore *mutex)
 354 {
 355         void *ret;
 356
 357         *error = down_interruptible(mutex);
 358         if (*error != 0)
 359                 return NULL;
 360
 361         ret = list_named_find(head, name);
 362         if (!ret) {
 363                 *error = -ENOENT;
 364                 up(mutex);
 365         }
 366         return ret;
 367 }
 368
 369 #ifndef CONFIG_KMOD
 370 #define find_inlist_lock(h,n,p,e,m) find_inlist_lock_noload((h),(n),(e),(m))
 371 #else
 372 static void *
 373 find_inlist_lock(struct list_head *head,
 374                  const char *name,
 375                  const char *prefix,
 376                  int *error,
 377                  struct semaphore *mutex)
 378 {
 379         void *ret;
 380
 381         ret = find_inlist_lock_noload(head, name, error, mutex);
 382         if (!ret) {
 383                 duprintf("find_inlist: loading `%s%s'.\n", prefix, name);
 384                 request_module("%s%s", prefix, name);
 385                 ret = find_inlist_lock_noload(head, name, error, mutex);
 386         }
 387
 388         return ret;
 389 }
 390 #endif
 391
 392 static inline struct arpt_table *arpt_find_table_lock(const char *name, int *error, struct semaphore *mutex)
 393 {
 394         return find_inlist_lock(&arpt_tables, name, "arptable_", error, mutex);
 395 }
 396
 397 static struct arpt_target *arpt_find_target_lock(const char *name, int *error, struct semaphore *mutex)
 398 {
 399         return find_inlist_lock(&arpt_target, name, "arpt_", error, mutex);
 400 }
 401
 402 /* All zeroes == unconditional rule. */
 403 static inline int unconditional(const struct arpt_arp *arp)
 404 {
 405         unsigned int i;
 406
 407         for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
 408                 if (((__u32 *)arp)[i])
 409                         return 0;
 410
 411         return 1;
 412 }
 413
 414 /* Figures out from what hook each rule can be called: returns 0 if
 415  * there are loops.  Puts hook bitmask in comefrom.
 416  */
 417 static int mark_source_chains(struct arpt_table_info *newinfo, unsigned int valid_hooks)
 418 {
 419         unsigned int hook;
 420
 421         /* No recursion; use packet counter to save back ptrs (reset
 422          * to 0 as we leave), and comefrom to save source hook bitmask.
 423          */
 424         for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
 425                 unsigned int pos = newinfo->hook_entry[hook];
 426                 struct arpt_entry *e
 427                         = (struct arpt_entry *)(newinfo->entries + pos);
 428
 429                 if (!(valid_hooks & (1 << hook)))
 430                         continue;
 431
 432                 /* Set initial back pointer. */
 433                 e->counters.pcnt = pos;
 434
 435                 for (;;) {
 436                         struct arpt_standard_target *t
 437                                 = (void *)arpt_get_target(e);
 438
 439                         if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
 440                                 printk("arptables: loop hook %u pos %u %08X.\n",
 441                                        hook, pos, e->comefrom);
 442                                 return 0;
 443                         }
 444                         e->comefrom
 445                                 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
 446
 447                         /* Unconditional return/END. */
 448                         if (e->target_offset == sizeof(struct arpt_entry)
 449                             && (strcmp(t->target.u.user.name,
 450                                        ARPT_STANDARD_TARGET) == 0)
 451                             && t->verdict < 0
 452                             && unconditional(&e->arp)) {
 453                                 unsigned int oldpos, size;
 454
 455                                 /* Return: backtrack through the last
 456                                  * big jump.
 457                                  */
 458                                 do {
 459                                         e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
 460                                         oldpos = pos;
 461                                         pos = e->counters.pcnt;
 462                                         e->counters.pcnt = 0;
 463
 464                                         /* We're at the start. */
 465                                         if (pos == oldpos)
 466                                                 goto next;
 467
 468                                         e = (struct arpt_entry *)
 469                                                 (newinfo->entries + pos);
 470                                 } while (oldpos == pos + e->next_offset);
 471
 472                                 /* Move along one */
 473                                 size = e->next_offset;
 474                                 e = (struct arpt_entry *)
 475                                         (newinfo->entries + pos + size);
 476                                 e->counters.pcnt = pos;
 477                                 pos += size;
 478                         } else {
 479                                 int newpos = t->verdict;
 480
 481                                 if (strcmp(t->target.u.user.name,
 482                                            ARPT_STANDARD_TARGET) == 0
 483                                     && newpos >= 0) {
 484                                         /* This a jump; chase it. */
 485                                         duprintf("Jump rule %u -> %u\n",
 486                                                  pos, newpos);
 487                                 } else {
 488                                         /* ... this is a fallthru */
 489                                         newpos = pos + e->next_offset;
 490                                 }
 491                                 e = (struct arpt_entry *)
 492                                         (newinfo->entries + newpos);
 493                                 e->counters.pcnt = pos;
 494                                 pos = newpos;
 495                         }
 496                 }
 497                 next:
 498                 duprintf("Finished chain %u\n", hook);
 499         }
 500         return 1;
 501 }
 502
 503 static inline int standard_check(const struct arpt_entry_target *t,
 504                                  unsigned int max_offset)
 505 {
 506         struct arpt_standard_target *targ = (void *)t;
 507
 508         /* Check standard info. */
 509         if (t->u.target_size
 510             != ARPT_ALIGN(sizeof(struct arpt_standard_target))) {
 511                 duprintf("arpt_standard_check: target size %u != %Zu\n",
 512                          t->u.target_size,
 513                          ARPT_ALIGN(sizeof(struct arpt_standard_target)));
 514                 return 0;
 515         }
 516
 517         if (targ->verdict >= 0
 518             && targ->verdict > max_offset - sizeof(struct arpt_entry)) {
 519                 duprintf("arpt_standard_check: bad verdict (%i)\n",
 520                          targ->verdict);
 521                 return 0;
 522         }
 523
 524         if (targ->verdict < -NF_MAX_VERDICT - 1) {
 525                 duprintf("arpt_standard_check: bad negative verdict (%i)\n",
 526                          targ->verdict);
 527                 return 0;
 528         }
 529         return 1;
 530 }
 531
 532 static struct arpt_target arpt_standard_target;
 533
 534 static inline int check_entry(struct arpt_entry *e, const char *name, unsigned int size,
 535                               unsigned int *i)
 536 {
 537         struct arpt_entry_target *t;
 538         struct arpt_target *target;
 539         int ret;
 540
 541         if (!arp_checkentry(&e->arp)) {
 542                 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
 543                 return -EINVAL;
 544         }
 545
 546         t = arpt_get_target(e);
 547         target = arpt_find_target_lock(t->u.user.name, &ret, &arpt_mutex);
 548         if (!target) {
 549                 duprintf("check_entry: `%s' not found\n", t->u.user.name);
 550                 goto out;
 551         }
 552         if (!try_module_get((target->me))) {
 553                 ret = -ENOENT;
 554                 goto out_unlock;
 555         }
 556         t->u.kernel.target = target;
 557         up(&arpt_mutex);
 558
 559         if (t->u.kernel.target == &arpt_standard_target) {
 560                 if (!standard_check(t, size)) {
 561                         ret = -EINVAL;
 562                         goto out;
 563                 }
 564         } else if (t->u.kernel.target->checkentry
 565                    && !t->u.kernel.target->checkentry(name, e, t->data,
 566                                                       t->u.target_size
 567                                                       - sizeof(*t),
 568                                                       e->comefrom)) {
 569                 module_put(t->u.kernel.target->me);
 570                 duprintf("arp_tables: check failed for `%s'.\n",
 571                          t->u.kernel.target->name);
 572                 ret = -EINVAL;
 573                 goto out;
 574         }
 575
 576         (*i)++;
 577         return 0;
 578
 579 out_unlock:
 580         up(&arpt_mutex);
 581 out:
 582         return ret;
 583 }
 584
 585 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
 586                                              struct arpt_table_info *newinfo,
 587                                              unsigned char *base,
 588                                              unsigned char *limit,
 589                                              const unsigned int *hook_entries,
 590                                              const unsigned int *underflows,
 591                                              unsigned int *i)
 592 {
 593         unsigned int h;
 594
 595         if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
 596             || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
 597                 duprintf("Bad offset %p\n", e);
 598                 return -EINVAL;
 599         }
 600
 601         if (e->next_offset
 602             < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
 603                 duprintf("checking: element %p size %u\n",
 604                          e, e->next_offset);
 605                 return -EINVAL;
 606         }
 607
 608         /* Check hooks & underflows */
 609         for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
 610                 if ((unsigned char *)e - base == hook_entries[h])
 611                         newinfo->hook_entry[h] = hook_entries[h];
 612                 if ((unsigned char *)e - base == underflows[h])
 613                         newinfo->underflow[h] = underflows[h];
 614         }
 615
 616         /* FIXME: underflows must be unconditional, standard verdicts
 617            < 0 (not ARPT_RETURN). --RR */
 618
 619         /* Clear counters and comefrom */
 620         e->counters = ((struct arpt_counters) { 0, 0 });
 621         e->comefrom = 0;
 622
 623         (*i)++;
 624         return 0;
 625 }
 626
 627 static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i)
 628 {
 629         struct arpt_entry_target *t;
 630
 631         if (i && (*i)-- == 0)
 632                 return 1;
 633
 634         t = arpt_get_target(e);
 635         if (t->u.kernel.target->destroy)
 636                 t->u.kernel.target->destroy(t->data,
 637                                             t->u.target_size - sizeof(*t));
 638         module_put(t->u.kernel.target->me);
 639         return 0;
 640 }
 641
 642 /* Checks and translates the user-supplied table segment (held in
 643  * newinfo).
 644  */
 645 static int translate_table(const char *name,
 646                            unsigned int valid_hooks,
 647                            struct arpt_table_info *newinfo,
 648                            unsigned int size,
 649                            unsigned int number,
 650                            const unsigned int *hook_entries,
 651                            const unsigned int *underflows)
 652 {
 653         unsigned int i;
 654         int ret;
 655
 656         newinfo->size = size;
 657         newinfo->number = number;
 658
 659         /* Init all hooks to impossible value. */
 660         for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
 661                 newinfo->hook_entry[i] = 0xFFFFFFFF;
 662                 newinfo->underflow[i] = 0xFFFFFFFF;
 663         }
 664
 665         duprintf("translate_table: size %u\n", newinfo->size);
 666         i = 0;
 667
 668         /* Walk through entries, checking offsets. */
 669         ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
 670                                  check_entry_size_and_hooks,
 671                                  newinfo,
 672                                  newinfo->entries,
 673                                  newinfo->entries + size,
 674                                  hook_entries, underflows, &i);
 675         duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
 676         if (ret != 0)
 677                 return ret;
 678
 679         if (i != number) {
 680                 duprintf("translate_table: %u not %u entries\n",
 681                          i, number);
 682                 return -EINVAL;
 683         }
 684
 685         /* Check hooks all assigned */
 686         for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
 687                 /* Only hooks which are valid */
 688                 if (!(valid_hooks & (1 << i)))
 689                         continue;
 690                 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
 691                         duprintf("Invalid hook entry %u %u\n",
 692                                  i, hook_entries[i]);
 693                         return -EINVAL;
 694                 }
 695                 if (newinfo->underflow[i] == 0xFFFFFFFF) {
 696                         duprintf("Invalid underflow %u %u\n",
 697                                  i, underflows[i]);
 698                         return -EINVAL;
 699                 }
 700         }
 701
 702         if (!mark_source_chains(newinfo, valid_hooks)) {
 703                 duprintf("Looping hook\n");
 704                 return -ELOOP;
 705         }
 706
 707         /* Finally, each sanity check must pass */
 708         i = 0;
 709         ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
 710                                  check_entry, name, size, &i);
 711
 712         if (ret != 0) {
 713                 ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
 714                                    cleanup_entry, &i);
 715                 return ret;
 716         }
 717
 718         /* And one copy for every other CPU */
 719         for (i = 1; i < num_possible_cpus(); i++) {
 720                 memcpy(newinfo->entries + SMP_ALIGN(newinfo->size)*i,
 721                        newinfo->entries,
 722                        SMP_ALIGN(newinfo->size));
 723         }
 724
 725         return ret;
 726 }
 727
 728 static struct arpt_table_info *replace_table(struct arpt_table *table,
 729                                              unsigned int num_counters,
 730                                              struct arpt_table_info *newinfo,
 731                                              int *error)
 732 {
 733         struct arpt_table_info *oldinfo;
 734
 735         /* Do the substitution. */
 736         write_lock_bh(&table->lock);
 737         /* Check inside lock: is the old number correct? */
 738         if (num_counters != table->private->number) {
 739                 duprintf("num_counters != table->private->number (%u/%u)\n",
 740                          num_counters, table->private->number);
 741                 write_unlock_bh(&table->lock);
 742                 *error = -EAGAIN;
 743                 return NULL;
 744         }
 745         oldinfo = table->private;
 746         table->private = newinfo;
 747         newinfo->initial_entries = oldinfo->initial_entries;
 748         write_unlock_bh(&table->lock);
 749
 750         return oldinfo;
 751 }
 752
 753 /* Gets counters. */
 754 static inline int add_entry_to_counter(const struct arpt_entry *e,
 755                                        struct arpt_counters total[],
 756                                        unsigned int *i)
 757 {
 758         ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
 759
 760         (*i)++;
 761         return 0;
 762 }
 763
 764 static void get_counters(const struct arpt_table_info *t,
 765                          struct arpt_counters counters[])
 766 {
 767         unsigned int cpu;
 768         unsigned int i;
 769
 770         for (cpu = 0; cpu < num_possible_cpus(); cpu++) {
 771                 i = 0;
 772                 ARPT_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu),
 773                                    t->size,
 774                                    add_entry_to_counter,
 775                                    counters,
 776                                    &i);
 777         }
 778 }
 779
 780 static int copy_entries_to_user(unsigned int total_size,
 781                                 struct arpt_table *table,
 782                                 void __user *userptr)
 783 {
 784         unsigned int off, num, countersize;
 785         struct arpt_entry *e;
 786         struct arpt_counters *counters;
 787         int ret = 0;
 788
 789         /* We need atomic snapshot of counters: rest doesn't change
 790          * (other than comefrom, which userspace doesn't care
 791          * about).
 792          */
 793         countersize = sizeof(struct arpt_counters) * table->private->number;
 794         counters = vmalloc(countersize);
 795
 796         if (counters == NULL)
 797                 return -ENOMEM;
 798
 799         /* First, sum counters... */
 800         memset(counters, 0, countersize);
 801         write_lock_bh(&table->lock);
 802         get_counters(table->private, counters);
 803         write_unlock_bh(&table->lock);
 804
 805         /* ... then copy entire thing from CPU 0... */
 806         if (copy_to_user(userptr, table->private->entries, total_size) != 0) {
 807                 ret = -EFAULT;
 808                 goto free_counters;
 809         }
 810
 811         /* FIXME: use iterator macros --RR */
 812         /* ... then go back and fix counters and names */
 813         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
 814                 struct arpt_entry_target *t;
 815
 816                 e = (struct arpt_entry *)(table->private->entries + off);
 817                 if (copy_to_user(userptr + off
 818                                  + offsetof(struct arpt_entry, counters),
 819                                  &counters[num],
 820                                  sizeof(counters[num])) != 0) {
 821                         ret = -EFAULT;
 822                         goto free_counters;
 823                 }
 824
 825                 t = arpt_get_target(e);
 826                 if (copy_to_user(userptr + off + e->target_offset
 827                                  + offsetof(struct arpt_entry_target,
 828                                             u.user.name),
 829                                  t->u.kernel.target->name,
 830                                  strlen(t->u.kernel.target->name)+1) != 0) {
 831                         ret = -EFAULT;
 832                         goto free_counters;
 833                 }
 834         }
 835
 836  free_counters:
 837         vfree(counters);
 838         return ret;
 839 }
 840
 841 static int get_entries(const struct arpt_get_entries *entries,
 842                        struct arpt_get_entries __user *uptr)
 843 {
 844         int ret;
 845         struct arpt_table *t;
 846
 847         t = arpt_find_table_lock(entries->name, &ret, &arpt_mutex);
 848         if (t) {
 849                 duprintf("t->private->number = %u\n",
 850                          t->private->number);
 851                 if (entries->size == t->private->size)
 852                         ret = copy_entries_to_user(t->private->size,
 853                                                    t, uptr->entrytable);
 854                 else {
 855                         duprintf("get_entries: I've got %u not %u!\n",
 856                                  t->private->size,
 857                                  entries->size);
 858                         ret = -EINVAL;
 859                 }
 860                 up(&arpt_mutex);
 861         } else
 862                 duprintf("get_entries: Can't find %s!\n",
 863                          entries->name);
 864
 865         return ret;
 866 }
 867
 868 static int do_replace(void __user *user, unsigned int len)
 869 {
 870         int ret;
 871         struct arpt_replace tmp;
 872         struct arpt_table *t;
 873         struct arpt_table_info *newinfo, *oldinfo;
 874         struct arpt_counters *counters;
 875
 876         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
 877                 return -EFAULT;
 878
 879         /* Hack: Causes ipchains to give correct error msg --RR */
 880         if (len != sizeof(tmp) + tmp.size)
 881                 return -ENOPROTOOPT;
 882
 883         /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
 884         if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages)
 885                 return -ENOMEM;
 886
 887         newinfo = vmalloc(sizeof(struct arpt_table_info)
 888                           + SMP_ALIGN(tmp.size) * num_possible_cpus());
 889         if (!newinfo)
 890                 return -ENOMEM;
 891
 892         if (copy_from_user(newinfo->entries, user + sizeof(tmp),
 893                            tmp.size) != 0) {
 894                 ret = -EFAULT;
 895                 goto free_newinfo;
 896         }
 897
 898         counters = vmalloc(tmp.num_counters * sizeof(struct arpt_counters));
 899         if (!counters) {
 900                 ret = -ENOMEM;
 901                 goto free_newinfo;
 902         }
 903         memset(counters, 0, tmp.num_counters * sizeof(struct arpt_counters));
 904
 905         ret = translate_table(tmp.name, tmp.valid_hooks,
 906                               newinfo, tmp.size, tmp.num_entries,
 907                               tmp.hook_entry, tmp.underflow);
 908         if (ret != 0)
 909                 goto free_newinfo_counters;
 910
 911         duprintf("arp_tables: Translated table\n");
 912
 913         t = arpt_find_table_lock(tmp.name, &ret, &arpt_mutex);
 914         if (!t)
 915                 goto free_newinfo_counters_untrans;
 916
 917         /* You lied! */
 918         if (tmp.valid_hooks != t->valid_hooks) {
 919                 duprintf("Valid hook crap: %08X vs %08X\n",
 920                          tmp.valid_hooks, t->valid_hooks);
 921                 ret = -EINVAL;
 922                 goto free_newinfo_counters_untrans_unlock;
 923         }
 924
 925         /* Get a reference in advance, we're not allowed fail later */
 926         if (!try_module_get(t->me)) {
 927                 ret = -EBUSY;
 928                 goto free_newinfo_counters_untrans_unlock;
 929         }
 930
 931         oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret);
 932         if (!oldinfo)
 933                 goto put_module;
 934
 935         /* Update module usage count based on number of rules */
 936         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
 937                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
 938         if ((oldinfo->number > oldinfo->initial_entries) ||
 939             (newinfo->number <= oldinfo->initial_entries))
 940                 module_put(t->me);
 941         if ((oldinfo->number > oldinfo->initial_entries) &&
 942             (newinfo->number <= oldinfo->initial_entries))
 943                 module_put(t->me);
 944
 945         /* Get the old counters. */
 946         get_counters(oldinfo, counters);
 947         /* Decrease module usage counts and free resource */
 948         ARPT_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL);
 949         vfree(oldinfo);
 950         if (copy_to_user(tmp.counters, counters,
 951                          sizeof(struct arpt_counters) * tmp.num_counters) != 0)
 952                 ret = -EFAULT;
 953         vfree(counters);
 954         up(&arpt_mutex);
 955         return ret;
 956
 957  put_module:
 958         module_put(t->me);
 959  free_newinfo_counters_untrans_unlock:
 960         up(&arpt_mutex);
 961  free_newinfo_counters_untrans:
 962         ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry, NULL);
 963  free_newinfo_counters:
 964         vfree(counters);
 965  free_newinfo:
 966         vfree(newinfo);
 967         return ret;
 968 }
 969
 970 /* We're lazy, and add to the first CPU; overflow works its fey magic
 971  * and everything is OK.
 972  */
 973 static inline int add_counter_to_entry(struct arpt_entry *e,
 974                                        const struct arpt_counters addme[],
 975                                        unsigned int *i)
 976 {
 977
 978         ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
 979
 980         (*i)++;
 981         return 0;
 982 }
 983
 984 static int do_add_counters(void __user *user, unsigned int len)
 985 {
 986         unsigned int i;
 987         struct arpt_counters_info tmp, *paddc;
 988         struct arpt_table *t;
 989         int ret;
 990
 991         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
 992                 return -EFAULT;
 993
 994         if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct arpt_counters))
 995                 return -EINVAL;
 996
 997         paddc = vmalloc(len);
 998         if (!paddc)
 999                 return -ENOMEM;
1000
1001         if (copy_from_user(paddc, user, len) != 0) {
1002                 ret = -EFAULT;
1003                 goto free;
1004         }
1005
1006         t = arpt_find_table_lock(tmp.name, &ret, &arpt_mutex);
1007         if (!t)
1008                 goto free;
1009
1010         write_lock_bh(&t->lock);
1011         if (t->private->number != paddc->num_counters) {
1012                 ret = -EINVAL;
1013                 goto unlock_up_free;
1014         }
1015
1016         i = 0;
1017         ARPT_ENTRY_ITERATE(t->private->entries,
1018                            t->private->size,
1019                            add_counter_to_entry,
1020                            paddc->counters,
1021                            &i);
1022  unlock_up_free:
1023         write_unlock_bh(&t->lock);
1024         up(&arpt_mutex);
1025  free:
1026         vfree(paddc);
1027
1028         return ret;
1029 }
1030
1031 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1032 {
1033         int ret;
1034
1035         if (!capable(CAP_NET_ADMIN))
1036                 return -EPERM;
1037
1038         switch (cmd) {
1039         case ARPT_SO_SET_REPLACE:
1040                 ret = do_replace(user, len);
1041                 break;
1042
1043         case ARPT_SO_SET_ADD_COUNTERS:
1044                 ret = do_add_counters(user, len);
1045                 break;
1046
1047         default:
1048                 duprintf("do_arpt_set_ctl:  unknown request %i\n", cmd);
1049                 ret = -EINVAL;
1050         }
1051
1052         return ret;
1053 }
1054
1055 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1056 {
1057         int ret;
1058
1059         if (!capable(CAP_NET_ADMIN))
1060                 return -EPERM;
1061
1062         switch (cmd) {
1063         case ARPT_SO_GET_INFO: {
1064                 char name[ARPT_TABLE_MAXNAMELEN];
1065                 struct arpt_table *t;
1066
1067                 if (*len != sizeof(struct arpt_getinfo)) {
1068                         duprintf("length %u != %Zu\n", *len,
1069                                  sizeof(struct arpt_getinfo));
1070                         ret = -EINVAL;
1071                         break;
1072                 }
1073
1074                 if (copy_from_user(name, user, sizeof(name)) != 0) {
1075                         ret = -EFAULT;
1076                         break;
1077                 }
1078                 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
1079                 t = arpt_find_table_lock(name, &ret, &arpt_mutex);
1080                 if (t) {
1081                         struct arpt_getinfo info;
1082
1083                         info.valid_hooks = t->valid_hooks;
1084                         memcpy(info.hook_entry, t->private->hook_entry,
1085                                sizeof(info.hook_entry));
1086                         memcpy(info.underflow, t->private->underflow,
1087                                sizeof(info.underflow));
1088                         info.num_entries = t->private->number;
1089                         info.size = t->private->size;
1090                         strcpy(info.name, name);
1091
1092                         if (copy_to_user(user, &info, *len) != 0)
1093                                 ret = -EFAULT;
1094                         else
1095                                 ret = 0;
1096
1097                         up(&arpt_mutex);
1098                 }
1099         }
1100         break;
1101
1102         case ARPT_SO_GET_ENTRIES: {
1103                 struct arpt_get_entries get;
1104
1105                 if (*len < sizeof(get)) {
1106                         duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
1107                         ret = -EINVAL;
1108                 } else if (copy_from_user(&get, user, sizeof(get)) != 0) {
1109                         ret = -EFAULT;
1110                 } else if (*len != sizeof(struct arpt_get_entries) + get.size) {
1111                         duprintf("get_entries: %u != %Zu\n", *len,
1112                                  sizeof(struct arpt_get_entries) + get.size);
1113                         ret = -EINVAL;
1114                 } else
1115                         ret = get_entries(&get, user);
1116                 break;
1117         }
1118
1119         default:
1120                 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1121                 ret = -EINVAL;
1122         }
1123
1124         return ret;
1125 }
1126
1127 /* Registration hooks for targets. */
1128 int arpt_register_target(struct arpt_target *target)
1129 {
1130         int ret;
1131
1132         ret = down_interruptible(&arpt_mutex);
1133         if (ret != 0)
1134                 return ret;
1135
1136         if (!list_named_insert(&arpt_target, target)) {
1137                 duprintf("arpt_register_target: `%s' already in list!\n",
1138                          target->name);
1139                 ret = -EINVAL;
1140         }
1141         up(&arpt_mutex);
1142         return ret;
1143 }
1144
1145 void arpt_unregister_target(struct arpt_target *target)
1146 {
1147         down(&arpt_mutex);
1148         LIST_DELETE(&arpt_target, target);
1149         up(&arpt_mutex);
1150 }
1151
1152 int arpt_register_table(struct arpt_table *table,
1153                         const struct arpt_replace *repl)
1154 {
1155         int ret;
1156         struct arpt_table_info *newinfo;
1157         static struct arpt_table_info bootstrap
1158                 = { 0, 0, 0, { 0 }, { 0 }, { } };
1159
1160         newinfo = vmalloc(sizeof(struct arpt_table_info)
1161                           + SMP_ALIGN(repl->size) * num_possible_cpus());
1162         if (!newinfo) {
1163                 ret = -ENOMEM;
1164                 return ret;
1165         }
1166         memcpy(newinfo->entries, repl->entries, repl->size);
1167
1168         ret = translate_table(table->name, table->valid_hooks,
1169                               newinfo, repl->size,
1170                               repl->num_entries,
1171                               repl->hook_entry,
1172                               repl->underflow);
1173         duprintf("arpt_register_table: translate table gives %d\n", ret);
1174         if (ret != 0) {
1175                 vfree(newinfo);
1176                 return ret;
1177         }
1178
1179         ret = down_interruptible(&arpt_mutex);
1180         if (ret != 0) {
1181                 vfree(newinfo);
1182                 return ret;
1183         }
1184
1185         /* Don't autoload: we'd eat our tail... */
1186         if (list_named_find(&arpt_tables, table->name)) {
1187                 ret = -EEXIST;
1188                 goto free_unlock;
1189         }
1190
1191         /* Simplifies replace_table code. */
1192         table->private = &bootstrap;
1193         if (!replace_table(table, 0, newinfo, &ret))
1194                 goto free_unlock;
1195
1196         duprintf("table->private->number = %u\n",
1197                  table->private->number);
1198
1199         /* save number of initial entries */
1200         table->private->initial_entries = table->private->number;
1201
1202         rwlock_init(&table->lock);
1203         list_prepend(&arpt_tables, table);
1204
1205  unlock:
1206         up(&arpt_mutex);
1207         return ret;
1208
1209  free_unlock:
1210         vfree(newinfo);
1211         goto unlock;
1212 }
1213
1214 void arpt_unregister_table(struct arpt_table *table)
1215 {
1216         down(&arpt_mutex);
1217         LIST_DELETE(&arpt_tables, table);
1218         up(&arpt_mutex);
1219
1220         /* Decrease module usage counts and free resources */
1221         ARPT_ENTRY_ITERATE(table->private->entries, table->private->size,
1222                            cleanup_entry, NULL);
1223         vfree(table->private);
1224 }
1225
1226 /* The built-in targets: standard (NULL) and error. */
1227 static struct arpt_target arpt_standard_target = {
1228         .name           = ARPT_STANDARD_TARGET,
1229 };
1230
1231 static struct arpt_target arpt_error_target = {
1232         .name           = ARPT_ERROR_TARGET,
1233         .target         = arpt_error,
1234 };
1235
1236 static struct nf_sockopt_ops arpt_sockopts = {
1237         .pf             = PF_INET,
1238         .set_optmin     = ARPT_BASE_CTL,
1239         .set_optmax     = ARPT_SO_SET_MAX+1,
1240         .set            = do_arpt_set_ctl,
1241         .get_optmin     = ARPT_BASE_CTL,
1242         .get_optmax     = ARPT_SO_GET_MAX+1,
1243         .get            = do_arpt_get_ctl,
1244 };
1245
1246 #ifdef CONFIG_PROC_FS
1247 static inline int print_name(const struct arpt_table *t,
1248                              off_t start_offset, char *buffer, int length,
1249                              off_t *pos, unsigned int *count)
1250 {
1251         if ((*count)++ >= start_offset) {
1252                 unsigned int namelen;
1253
1254                 namelen = sprintf(buffer + *pos, "%s\n", t->name);
1255                 if (*pos + namelen > length) {
1256                         /* Stop iterating */
1257                         return 1;
1258                 }
1259                 *pos += namelen;
1260         }
1261         return 0;
1262 }
1263
1264 static int arpt_get_tables(char *buffer, char **start, off_t offset, int length)
1265 {
1266         off_t pos = 0;
1267         unsigned int count = 0;
1268
1269         if (down_interruptible(&arpt_mutex) != 0)
1270                 return 0;
1271
1272         LIST_FIND(&arpt_tables, print_name, struct arpt_table *,
1273                   offset, buffer, length, &pos, &count);
1274
1275         up(&arpt_mutex);
1276
1277         /* `start' hack - see fs/proc/generic.c line ~105 */
1278         *start=(char *)((unsigned long)count-offset);
1279         return pos;
1280 }
1281 #endif /*CONFIG_PROC_FS*/
1282
1283 static int __init init(void)
1284 {
1285         int ret;
1286
1287         /* Noone else will be downing sem now, so we won't sleep */
1288         down(&arpt_mutex);
1289         list_append(&arpt_target, &arpt_standard_target);
1290         list_append(&arpt_target, &arpt_error_target);
1291         up(&arpt_mutex);
1292
1293         /* Register setsockopt */
1294         ret = nf_register_sockopt(&arpt_sockopts);
1295         if (ret < 0) {
1296                 duprintf("Unable to register sockopts.\n");
1297                 return ret;
1298         }
1299
1300 #ifdef CONFIG_PROC_FS
1301         {
1302                 struct proc_dir_entry *proc;
1303
1304                 proc = proc_net_create("arp_tables_names", 0, arpt_get_tables);
1305                 if (!proc) {
1306                         nf_unregister_sockopt(&arpt_sockopts);
1307                         return -ENOMEM;
1308                 }
1309                 proc->owner = THIS_MODULE;
1310         }
1311 #endif
1312
1313         printk("arp_tables: (C) 2002 David S. Miller\n");
1314         return 0;
1315 }
1316
1317 static void __exit fini(void)
1318 {
1319         nf_unregister_sockopt(&arpt_sockopts);
1320 #ifdef CONFIG_PROC_FS
1321         proc_net_remove("arp_tables_names");
1322 #endif
1323 }
1324
1325 EXPORT_SYMBOL(arpt_register_table);
1326 EXPORT_SYMBOL(arpt_unregister_table);
1327 EXPORT_SYMBOL(arpt_do_table);
1328 EXPORT_SYMBOL(arpt_register_target);
1329 EXPORT_SYMBOL(arpt_unregister_target);
1330
1331 module_init(init);
1332 module_exit(fini);