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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/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/lockhelp.h>
  64 #include <linux/netfilter_ipv4/listhelp.h>
  65
  66 struct arpt_table_info {
  67         unsigned int size;
  68         unsigned int number;
  69         unsigned int initial_entries;
  70         unsigned int hook_entry[NF_ARP_NUMHOOKS];
  71         unsigned int underflow[NF_ARP_NUMHOOKS];
  72         char entries[0] __attribute__((aligned(SMP_CACHE_BYTES)));
  73 };
  74
  75 static LIST_HEAD(arpt_target);
  76 static LIST_HEAD(arpt_tables);
  77 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
  78
  79 #ifdef CONFIG_SMP
  80 #define TABLE_OFFSET(t,p) (SMP_ALIGN((t)->size)*(p))
  81 #else
  82 #define TABLE_OFFSET(t,p) 0
  83 #endif
  84
  85 static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
  86                                       char *hdr_addr, int len)
  87 {
  88         int i, ret;
  89
  90         if (len > ARPT_DEV_ADDR_LEN_MAX)
  91                 len = ARPT_DEV_ADDR_LEN_MAX;
  92
  93         ret = 0;
  94         for (i = 0; i < len; i++)
  95                 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
  96
  97         return (ret != 0);
  98 }
  99
 100 /* Returns whether packet matches rule or not. */
 101 static inline int arp_packet_match(const struct arphdr *arphdr,
 102                                    struct net_device *dev,
 103                                    const char *indev,
 104                                    const char *outdev,
 105                                    const struct arpt_arp *arpinfo)
 106 {
 107         char *arpptr = (char *)(arphdr + 1);
 108         char *src_devaddr, *tgt_devaddr;
 109         u32 src_ipaddr, tgt_ipaddr;
 110         int i, ret;
 111
 112 #define FWINV(bool,invflg) ((bool) ^ !!(arpinfo->invflags & invflg))
 113
 114         if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
 115                   ARPT_INV_ARPOP)) {
 116                 dprintf("ARP operation field mismatch.\n");
 117                 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
 118                         arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
 119                 return 0;
 120         }
 121
 122         if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
 123                   ARPT_INV_ARPHRD)) {
 124                 dprintf("ARP hardware address format mismatch.\n");
 125                 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
 126                         arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
 127                 return 0;
 128         }
 129
 130         if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
 131                   ARPT_INV_ARPPRO)) {
 132                 dprintf("ARP protocol address format mismatch.\n");
 133                 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
 134                         arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
 135                 return 0;
 136         }
 137
 138         if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
 139                   ARPT_INV_ARPHLN)) {
 140                 dprintf("ARP hardware address length mismatch.\n");
 141                 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
 142                         arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
 143                 return 0;
 144         }
 145
 146         src_devaddr = arpptr;
 147         arpptr += dev->addr_len;
 148         memcpy(&src_ipaddr, arpptr, sizeof(u32));
 149         arpptr += sizeof(u32);
 150         tgt_devaddr = arpptr;
 151         arpptr += dev->addr_len;
 152         memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
 153
 154         if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
 155                   ARPT_INV_SRCDEVADDR) ||
 156             FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
 157                   ARPT_INV_TGTDEVADDR)) {
 158                 dprintf("Source or target device address mismatch.\n");
 159
 160                 return 0;
 161         }
 162
 163         if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
 164                   ARPT_INV_SRCIP) ||
 165             FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
 166                   ARPT_INV_TGTIP)) {
 167                 dprintf("Source or target IP address mismatch.\n");
 168
 169                 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
 170                         NIPQUAD(src_ipaddr),
 171                         NIPQUAD(arpinfo->smsk.s_addr),
 172                         NIPQUAD(arpinfo->src.s_addr),
 173                         arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
 174                 dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
 175                         NIPQUAD(tgt_ipaddr),
 176                         NIPQUAD(arpinfo->tmsk.s_addr),
 177                         NIPQUAD(arpinfo->tgt.s_addr),
 178                         arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
 179                 return 0;
 180         }
 181
 182         /* Look for ifname matches.  */
 183         for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
 184                 ret |= (indev[i] ^ arpinfo->iniface[i])
 185                         & arpinfo->iniface_mask[i];
 186         }
 187
 188         if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
 189                 dprintf("VIA in mismatch (%s vs %s).%s\n",
 190                         indev, arpinfo->iniface,
 191                         arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
 192                 return 0;
 193         }
 194
 195         for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
 196                 unsigned long odev;
 197                 memcpy(&odev, outdev + i*sizeof(unsigned long),
 198                        sizeof(unsigned long));
 199                 ret |= (odev
 200                         ^ ((const unsigned long *)arpinfo->outiface)[i])
 201                         & ((const unsigned long *)arpinfo->outiface_mask)[i];
 202         }
 203
 204         if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
 205                 dprintf("VIA out mismatch (%s vs %s).%s\n",
 206                         outdev, arpinfo->outiface,
 207                         arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
 208                 return 0;
 209         }
 210
 211         return 1;
 212 }
 213
 214 static inline int arp_checkentry(const struct arpt_arp *arp)
 215 {
 216         if (arp->flags & ~ARPT_F_MASK) {
 217                 duprintf("Unknown flag bits set: %08X\n",
 218                          arp->flags & ~ARPT_F_MASK);
 219                 return 0;
 220         }
 221         if (arp->invflags & ~ARPT_INV_MASK) {
 222                 duprintf("Unknown invflag bits set: %08X\n",
 223                          arp->invflags & ~ARPT_INV_MASK);
 224                 return 0;
 225         }
 226
 227         return 1;
 228 }
 229
 230 static unsigned int arpt_error(struct sk_buff **pskb,
 231                                unsigned int hooknum,
 232                                const struct net_device *in,
 233                                const struct net_device *out,
 234                                const void *targinfo,
 235                                void *userinfo)
 236 {
 237         if (net_ratelimit())
 238                 printk("arp_tables: error: '%s'\n", (char *)targinfo);
 239
 240         return NF_DROP;
 241 }
 242
 243 static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
 244 {
 245         return (struct arpt_entry *)(base + offset);
 246 }
 247
 248 unsigned int arpt_do_table(struct sk_buff **pskb,
 249                            unsigned int hook,
 250                            const struct net_device *in,
 251                            const struct net_device *out,
 252                            struct arpt_table *table,
 253                            void *userdata)
 254 {
 255         static const char nulldevname[IFNAMSIZ];
 256         unsigned int verdict = NF_DROP;
 257         struct arphdr *arp;
 258         int hotdrop = 0;
 259         struct arpt_entry *e, *back;
 260         const char *indev, *outdev;
 261         void *table_base;
 262
 263         /* ARP header, plus 2 device addresses, plus 2 IP addresses.  */
 264         if (!pskb_may_pull((*pskb), (sizeof(struct arphdr) +
 265                                      (2 * (*pskb)->dev->addr_len) +
 266                                      (2 * sizeof(u32)))))
 267                 return NF_DROP;
 268
 269         indev = in ? in->name : nulldevname;
 270         outdev = out ? out->name : nulldevname;
 271
 272         read_lock_bh(&table->lock);
 273         table_base = (void *)table->private->entries
 274                 + TABLE_OFFSET(table->private,
 275                                smp_processor_id());
 276         e = get_entry(table_base, table->private->hook_entry[hook]);
 277         back = get_entry(table_base, table->private->underflow[hook]);
 278
 279         arp = (*pskb)->nh.arph;
 280         do {
 281                 if (arp_packet_match(arp, (*pskb)->dev, indev, outdev, &e->arp)) {
 282                         struct arpt_entry_target *t;
 283                         int hdr_len;
 284
 285                         hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
 286                                 (2 * (*pskb)->dev->addr_len);
 287                         ADD_COUNTER(e->counters, hdr_len, 1);
 288
 289                         t = arpt_get_target(e);
 290
 291                         /* Standard target? */
 292                         if (!t->u.kernel.target->target) {
 293                                 int v;
 294
 295                                 v = ((struct arpt_standard_target *)t)->verdict;
 296                                 if (v < 0) {
 297                                         /* Pop from stack? */
 298                                         if (v != ARPT_RETURN) {
 299                                                 verdict = (unsigned)(-v) - 1;
 300                                                 break;
 301                                         }
 302                                         e = back;
 303                                         back = get_entry(table_base,
 304                                                          back->comefrom);
 305                                         continue;
 306                                 }
 307                                 if (table_base + v
 308                                     != (void *)e + e->next_offset) {
 309                                         /* Save old back ptr in next entry */
 310                                         struct arpt_entry *next
 311                                                 = (void *)e + e->next_offset;
 312                                         next->comefrom =
 313                                                 (void *)back - table_base;
 314
 315                                         /* set back pointer to next entry */
 316                                         back = next;
 317                                 }
 318
 319                                 e = get_entry(table_base, v);
 320                         } else {
 321                                 /* Targets which reenter must return
 322                                  * abs. verdicts
 323                                  */
 324                                 verdict = t->u.kernel.target->target(pskb,
 325                                                                      hook,
 326                                                                      in, out,
 327                                                                      t->data,
 328                                                                      userdata);
 329
 330                                 /* Target might have changed stuff. */
 331                                 arp = (*pskb)->nh.arph;
 332
 333                                 if (verdict == ARPT_CONTINUE)
 334                                         e = (void *)e + e->next_offset;
 335                                 else
 336                                         /* Verdict */
 337                                         break;
 338                         }
 339                 } else {
 340                         e = (void *)e + e->next_offset;
 341                 }
 342         } while (!hotdrop);
 343         read_unlock_bh(&table->lock);
 344
 345         if (hotdrop)
 346                 return NF_DROP;
 347         else
 348                 return verdict;
 349 }
 350
 351 static inline void *find_inlist_lock_noload(struct list_head *head,
 352                                             const char *name,
 353                                             int *error,
 354                                             struct semaphore *mutex)
 355 {
 356         void *ret;
 357
 358         *error = down_interruptible(mutex);
 359         if (*error != 0)
 360                 return NULL;
 361
 362         ret = list_named_find(head, name);
 363         if (!ret) {
 364                 *error = -ENOENT;
 365                 up(mutex);
 366         }
 367         return ret;
 368 }
 369
 370 #ifndef CONFIG_KMOD
 371 #define find_inlist_lock(h,n,p,e,m) find_inlist_lock_noload((h),(n),(e),(m))
 372 #else
 373 static void *
 374 find_inlist_lock(struct list_head *head,
 375                  const char *name,
 376                  const char *prefix,
 377                  int *error,
 378                  struct semaphore *mutex)
 379 {
 380         void *ret;
 381
 382         ret = find_inlist_lock_noload(head, name, error, mutex);
 383         if (!ret) {
 384                 duprintf("find_inlist: loading `%s%s'.\n", prefix, name);
 385                 request_module("%s%s", prefix, name);
 386                 ret = find_inlist_lock_noload(head, name, error, mutex);
 387         }
 388
 389         return ret;
 390 }
 391 #endif
 392
 393 static inline struct arpt_table *arpt_find_table_lock(const char *name, int *error, struct semaphore *mutex)
 394 {
 395         return find_inlist_lock(&arpt_tables, name, "arptable_", error, mutex);
 396 }
 397
 398 static struct arpt_target *arpt_find_target_lock(const char *name, int *error, struct semaphore *mutex)
 399 {
 400         return find_inlist_lock(&arpt_target, name, "arpt_", error, mutex);
 401 }
 402
 403 /* All zeroes == unconditional rule. */
 404 static inline int unconditional(const struct arpt_arp *arp)
 405 {
 406         unsigned int i;
 407
 408         for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
 409                 if (((__u32 *)arp)[i])
 410                         return 0;
 411
 412         return 1;
 413 }
 414
 415 /* Figures out from what hook each rule can be called: returns 0 if
 416  * there are loops.  Puts hook bitmask in comefrom.
 417  */
 418 static int mark_source_chains(struct arpt_table_info *newinfo, unsigned int valid_hooks)
 419 {
 420         unsigned int hook;
 421
 422         /* No recursion; use packet counter to save back ptrs (reset
 423          * to 0 as we leave), and comefrom to save source hook bitmask.
 424          */
 425         for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
 426                 unsigned int pos = newinfo->hook_entry[hook];
 427                 struct arpt_entry *e
 428                         = (struct arpt_entry *)(newinfo->entries + pos);
 429
 430                 if (!(valid_hooks & (1 << hook)))
 431                         continue;
 432
 433                 /* Set initial back pointer. */
 434                 e->counters.pcnt = pos;
 435
 436                 for (;;) {
 437                         struct arpt_standard_target *t
 438                                 = (void *)arpt_get_target(e);
 439
 440                         if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
 441                                 printk("arptables: loop hook %u pos %u %08X.\n",
 442                                        hook, pos, e->comefrom);
 443                                 return 0;
 444                         }
 445                         e->comefrom
 446                                 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
 447
 448                         /* Unconditional return/END. */
 449                         if (e->target_offset == sizeof(struct arpt_entry)
 450                             && (strcmp(t->target.u.user.name,
 451                                        ARPT_STANDARD_TARGET) == 0)
 452                             && t->verdict < 0
 453                             && unconditional(&e->arp)) {
 454                                 unsigned int oldpos, size;
 455
 456                                 /* Return: backtrack through the last
 457                                  * big jump.
 458                                  */
 459                                 do {
 460                                         e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
 461                                         oldpos = pos;
 462                                         pos = e->counters.pcnt;
 463                                         e->counters.pcnt = 0;
 464
 465                                         /* We're at the start. */
 466                                         if (pos == oldpos)
 467                                                 goto next;
 468
 469                                         e = (struct arpt_entry *)
 470                                                 (newinfo->entries + pos);
 471                                 } while (oldpos == pos + e->next_offset);
 472
 473                                 /* Move along one */
 474                                 size = e->next_offset;
 475                                 e = (struct arpt_entry *)
 476                                         (newinfo->entries + pos + size);
 477                                 e->counters.pcnt = pos;
 478                                 pos += size;
 479                         } else {
 480                                 int newpos = t->verdict;
 481
 482                                 if (strcmp(t->target.u.user.name,
 483                                            ARPT_STANDARD_TARGET) == 0
 484                                     && newpos >= 0) {
 485                                         /* This a jump; chase it. */
 486                                         duprintf("Jump rule %u -> %u\n",
 487                                                  pos, newpos);
 488                                 } else {
 489                                         /* ... this is a fallthru */
 490                                         newpos = pos + e->next_offset;
 491                                 }
 492                                 e = (struct arpt_entry *)
 493                                         (newinfo->entries + newpos);
 494                                 e->counters.pcnt = pos;
 495                                 pos = newpos;
 496                         }
 497                 }
 498                 next:
 499                 duprintf("Finished chain %u\n", hook);
 500         }
 501         return 1;
 502 }
 503
 504 static inline int standard_check(const struct arpt_entry_target *t,
 505                                  unsigned int max_offset)
 506 {
 507         struct arpt_standard_target *targ = (void *)t;
 508
 509         /* Check standard info. */
 510         if (t->u.target_size
 511             != ARPT_ALIGN(sizeof(struct arpt_standard_target))) {
 512                 duprintf("arpt_standard_check: target size %u != %Zu\n",
 513                          t->u.target_size,
 514                          ARPT_ALIGN(sizeof(struct arpt_standard_target)));
 515                 return 0;
 516         }
 517
 518         if (targ->verdict >= 0
 519             && targ->verdict > max_offset - sizeof(struct arpt_entry)) {
 520                 duprintf("arpt_standard_check: bad verdict (%i)\n",
 521                          targ->verdict);
 522                 return 0;
 523         }
 524
 525         if (targ->verdict < -NF_MAX_VERDICT - 1) {
 526                 duprintf("arpt_standard_check: bad negative verdict (%i)\n",
 527                          targ->verdict);
 528                 return 0;
 529         }
 530         return 1;
 531 }
 532
 533 static struct arpt_target arpt_standard_target;
 534
 535 static inline int check_entry(struct arpt_entry *e, const char *name, unsigned int size,
 536                               unsigned int *i)
 537 {
 538         struct arpt_entry_target *t;
 539         struct arpt_target *target;
 540         int ret;
 541
 542         if (!arp_checkentry(&e->arp)) {
 543                 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
 544                 return -EINVAL;
 545         }
 546
 547         t = arpt_get_target(e);
 548         target = arpt_find_target_lock(t->u.user.name, &ret, &arpt_mutex);
 549         if (!target) {
 550                 duprintf("check_entry: `%s' not found\n", t->u.user.name);
 551                 goto out;
 552         }
 553         if (!try_module_get((target->me))) {
 554                 ret = -ENOENT;
 555                 goto out_unlock;
 556         }
 557         t->u.kernel.target = target;
 558         up(&arpt_mutex);
 559
 560         if (t->u.kernel.target == &arpt_standard_target) {
 561                 if (!standard_check(t, size)) {
 562                         ret = -EINVAL;
 563                         goto out;
 564                 }
 565         } else if (t->u.kernel.target->checkentry
 566                    && !t->u.kernel.target->checkentry(name, e, t->data,
 567                                                       t->u.target_size
 568                                                       - sizeof(*t),
 569                                                       e->comefrom)) {
 570                 module_put(t->u.kernel.target->me);
 571                 duprintf("arp_tables: check failed for `%s'.\n",
 572                          t->u.kernel.target->name);
 573                 ret = -EINVAL;
 574                 goto out;
 575         }
 576
 577         (*i)++;
 578         return 0;
 579
 580 out_unlock:
 581         up(&arpt_mutex);
 582 out:
 583         return ret;
 584 }
 585
 586 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
 587                                              struct arpt_table_info *newinfo,
 588                                              unsigned char *base,
 589                                              unsigned char *limit,
 590                                              const unsigned int *hook_entries,
 591                                              const unsigned int *underflows,
 592                                              unsigned int *i)
 593 {
 594         unsigned int h;
 595
 596         if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
 597             || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
 598                 duprintf("Bad offset %p\n", e);
 599                 return -EINVAL;
 600         }
 601
 602         if (e->next_offset
 603             < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
 604                 duprintf("checking: element %p size %u\n",
 605                          e, e->next_offset);
 606                 return -EINVAL;
 607         }
 608
 609         /* Check hooks & underflows */
 610         for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
 611                 if ((unsigned char *)e - base == hook_entries[h])
 612                         newinfo->hook_entry[h] = hook_entries[h];
 613                 if ((unsigned char *)e - base == underflows[h])
 614                         newinfo->underflow[h] = underflows[h];
 615         }
 616
 617         /* FIXME: underflows must be unconditional, standard verdicts
 618            < 0 (not ARPT_RETURN). --RR */
 619
 620         /* Clear counters and comefrom */
 621         e->counters = ((struct arpt_counters) { 0, 0 });
 622         e->comefrom = 0;
 623
 624         (*i)++;
 625         return 0;
 626 }
 627
 628 static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i)
 629 {
 630         struct arpt_entry_target *t;
 631
 632         if (i && (*i)-- == 0)
 633                 return 1;
 634
 635         t = arpt_get_target(e);
 636         if (t->u.kernel.target->destroy)
 637                 t->u.kernel.target->destroy(t->data,
 638                                             t->u.target_size - sizeof(*t));
 639         module_put(t->u.kernel.target->me);
 640         return 0;
 641 }
 642
 643 /* Checks and translates the user-supplied table segment (held in
 644  * newinfo).
 645  */
 646 static int translate_table(const char *name,
 647                            unsigned int valid_hooks,
 648                            struct arpt_table_info *newinfo,
 649                            unsigned int size,
 650                            unsigned int number,
 651                            const unsigned int *hook_entries,
 652                            const unsigned int *underflows)
 653 {
 654         unsigned int i;
 655         int ret;
 656
 657         newinfo->size = size;
 658         newinfo->number = number;
 659
 660         /* Init all hooks to impossible value. */
 661         for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
 662                 newinfo->hook_entry[i] = 0xFFFFFFFF;
 663                 newinfo->underflow[i] = 0xFFFFFFFF;
 664         }
 665
 666         duprintf("translate_table: size %u\n", newinfo->size);
 667         i = 0;
 668
 669         /* Walk through entries, checking offsets. */
 670         ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
 671                                  check_entry_size_and_hooks,
 672                                  newinfo,
 673                                  newinfo->entries,
 674                                  newinfo->entries + size,
 675                                  hook_entries, underflows, &i);
 676         duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
 677         if (ret != 0)
 678                 return ret;
 679
 680         if (i != number) {
 681                 duprintf("translate_table: %u not %u entries\n",
 682                          i, number);
 683                 return -EINVAL;
 684         }
 685
 686         /* Check hooks all assigned */
 687         for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
 688                 /* Only hooks which are valid */
 689                 if (!(valid_hooks & (1 << i)))
 690                         continue;
 691                 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
 692                         duprintf("Invalid hook entry %u %u\n",
 693                                  i, hook_entries[i]);
 694                         return -EINVAL;
 695                 }
 696                 if (newinfo->underflow[i] == 0xFFFFFFFF) {
 697                         duprintf("Invalid underflow %u %u\n",
 698                                  i, underflows[i]);
 699                         return -EINVAL;
 700                 }
 701         }
 702
 703         if (!mark_source_chains(newinfo, valid_hooks)) {
 704                 duprintf("Looping hook\n");
 705                 return -ELOOP;
 706         }
 707
 708         /* Finally, each sanity check must pass */
 709         i = 0;
 710         ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
 711                                  check_entry, name, size, &i);
 712
 713         if (ret != 0) {
 714                 ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
 715                                    cleanup_entry, &i);
 716                 return ret;
 717         }
 718
 719         /* And one copy for every other CPU */
 720         for (i = 1; i < num_possible_cpus(); i++) {
 721                 memcpy(newinfo->entries + SMP_ALIGN(newinfo->size)*i,
 722                        newinfo->entries,
 723                        SMP_ALIGN(newinfo->size));
 724         }
 725
 726         return ret;
 727 }
 728
 729 static struct arpt_table_info *replace_table(struct arpt_table *table,
 730                                              unsigned int num_counters,
 731                                              struct arpt_table_info *newinfo,
 732                                              int *error)
 733 {
 734         struct arpt_table_info *oldinfo;
 735
 736         /* Do the substitution. */
 737         write_lock_bh(&table->lock);
 738         /* Check inside lock: is the old number correct? */
 739         if (num_counters != table->private->number) {
 740                 duprintf("num_counters != table->private->number (%u/%u)\n",
 741                          num_counters, table->private->number);
 742                 write_unlock_bh(&table->lock);
 743                 *error = -EAGAIN;
 744                 return NULL;
 745         }
 746         oldinfo = table->private;
 747         table->private = newinfo;
 748         newinfo->initial_entries = oldinfo->initial_entries;
 749         write_unlock_bh(&table->lock);
 750
 751         return oldinfo;
 752 }
 753
 754 /* Gets counters. */
 755 static inline int add_entry_to_counter(const struct arpt_entry *e,
 756                                        struct arpt_counters total[],
 757                                        unsigned int *i)
 758 {
 759         ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
 760
 761         (*i)++;
 762         return 0;
 763 }
 764
 765 static void get_counters(const struct arpt_table_info *t,
 766                          struct arpt_counters counters[])
 767 {
 768         unsigned int cpu;
 769         unsigned int i;
 770
 771         for (cpu = 0; cpu < num_possible_cpus(); cpu++) {
 772                 i = 0;
 773                 ARPT_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu),
 774                                    t->size,
 775                                    add_entry_to_counter,
 776                                    counters,
 777                                    &i);
 778         }
 779 }
 780
 781 static int copy_entries_to_user(unsigned int total_size,
 782                                 struct arpt_table *table,
 783                                 void __user *userptr)
 784 {
 785         unsigned int off, num, countersize;
 786         struct arpt_entry *e;
 787         struct arpt_counters *counters;
 788         int ret = 0;
 789
 790         /* We need atomic snapshot of counters: rest doesn't change
 791          * (other than comefrom, which userspace doesn't care
 792          * about).
 793          */
 794         countersize = sizeof(struct arpt_counters) * table->private->number;
 795         counters = vmalloc(countersize);
 796
 797         if (counters == NULL)
 798                 return -ENOMEM;
 799
 800         /* First, sum counters... */
 801         memset(counters, 0, countersize);
 802         write_lock_bh(&table->lock);
 803         get_counters(table->private, counters);
 804         write_unlock_bh(&table->lock);
 805
 806         /* ... then copy entire thing from CPU 0... */
 807         if (copy_to_user(userptr, table->private->entries, total_size) != 0) {
 808                 ret = -EFAULT;
 809                 goto free_counters;
 810         }
 811
 812         /* FIXME: use iterator macros --RR */
 813         /* ... then go back and fix counters and names */
 814         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
 815                 struct arpt_entry_target *t;
 816
 817                 e = (struct arpt_entry *)(table->private->entries + off);
 818                 if (copy_to_user(userptr + off
 819                                  + offsetof(struct arpt_entry, counters),
 820                                  &counters[num],
 821                                  sizeof(counters[num])) != 0) {
 822                         ret = -EFAULT;
 823                         goto free_counters;
 824                 }
 825
 826                 t = arpt_get_target(e);
 827                 if (copy_to_user(userptr + off + e->target_offset
 828                                  + offsetof(struct arpt_entry_target,
 829                                             u.user.name),
 830                                  t->u.kernel.target->name,
 831                                  strlen(t->u.kernel.target->name)+1) != 0) {
 832                         ret = -EFAULT;
 833                         goto free_counters;
 834                 }
 835         }
 836
 837  free_counters:
 838         vfree(counters);
 839         return ret;
 840 }
 841
 842 static int get_entries(const struct arpt_get_entries *entries,
 843                        struct arpt_get_entries __user *uptr)
 844 {
 845         int ret;
 846         struct arpt_table *t;
 847
 848         t = arpt_find_table_lock(entries->name, &ret, &arpt_mutex);
 849         if (t) {
 850                 duprintf("t->private->number = %u\n",
 851                          t->private->number);
 852                 if (entries->size == t->private->size)
 853                         ret = copy_entries_to_user(t->private->size,
 854                                                    t, uptr->entrytable);
 855                 else {
 856                         duprintf("get_entries: I've got %u not %u!\n",
 857                                  t->private->size,
 858                                  entries->size);
 859                         ret = -EINVAL;
 860                 }
 861                 up(&arpt_mutex);
 862         } else
 863                 duprintf("get_entries: Can't find %s!\n",
 864                          entries->name);
 865
 866         return ret;
 867 }
 868
 869 static int do_replace(void __user *user, unsigned int len)
 870 {
 871         int ret;
 872         struct arpt_replace tmp;
 873         struct arpt_table *t;
 874         struct arpt_table_info *newinfo, *oldinfo;
 875         struct arpt_counters *counters;
 876
 877         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
 878                 return -EFAULT;
 879
 880         /* Hack: Causes ipchains to give correct error msg --RR */
 881         if (len != sizeof(tmp) + tmp.size)
 882                 return -ENOPROTOOPT;
 883
 884         /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
 885         if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages)
 886                 return -ENOMEM;
 887
 888         newinfo = vmalloc(sizeof(struct arpt_table_info)
 889                           + SMP_ALIGN(tmp.size) * num_possible_cpus());
 890         if (!newinfo)
 891                 return -ENOMEM;
 892
 893         if (copy_from_user(newinfo->entries, user + sizeof(tmp),
 894                            tmp.size) != 0) {
 895                 ret = -EFAULT;
 896                 goto free_newinfo;
 897         }
 898
 899         counters = vmalloc(tmp.num_counters * sizeof(struct arpt_counters));
 900         if (!counters) {
 901                 ret = -ENOMEM;
 902                 goto free_newinfo;
 903         }
 904         memset(counters, 0, tmp.num_counters * sizeof(struct arpt_counters));
 905
 906         ret = translate_table(tmp.name, tmp.valid_hooks,
 907                               newinfo, tmp.size, tmp.num_entries,
 908                               tmp.hook_entry, tmp.underflow);
 909         if (ret != 0)
 910                 goto free_newinfo_counters;
 911
 912         duprintf("arp_tables: Translated table\n");
 913
 914         t = arpt_find_table_lock(tmp.name, &ret, &arpt_mutex);
 915         if (!t)
 916                 goto free_newinfo_counters_untrans;
 917
 918         /* You lied! */
 919         if (tmp.valid_hooks != t->valid_hooks) {
 920                 duprintf("Valid hook crap: %08X vs %08X\n",
 921                          tmp.valid_hooks, t->valid_hooks);
 922                 ret = -EINVAL;
 923                 goto free_newinfo_counters_untrans_unlock;
 924         }
 925
 926         /* Get a reference in advance, we're not allowed fail later */
 927         if (!try_module_get(t->me)) {
 928                 ret = -EBUSY;
 929                 goto free_newinfo_counters_untrans_unlock;
 930         }
 931
 932         oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret);
 933         if (!oldinfo)
 934                 goto put_module;
 935
 936         /* Update module usage count based on number of rules */
 937         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
 938                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
 939         if ((oldinfo->number > oldinfo->initial_entries) ||
 940             (newinfo->number <= oldinfo->initial_entries))
 941                 module_put(t->me);
 942         if ((oldinfo->number > oldinfo->initial_entries) &&
 943             (newinfo->number <= oldinfo->initial_entries))
 944                 module_put(t->me);
 945
 946         /* Get the old counters. */
 947         get_counters(oldinfo, counters);
 948         /* Decrease module usage counts and free resource */
 949         ARPT_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL);
 950         vfree(oldinfo);
 951         if (copy_to_user(tmp.counters, counters,
 952                          sizeof(struct arpt_counters) * tmp.num_counters) != 0)
 953                 ret = -EFAULT;
 954         vfree(counters);
 955         up(&arpt_mutex);
 956         return ret;
 957
 958  put_module:
 959         module_put(t->me);
 960  free_newinfo_counters_untrans_unlock:
 961         up(&arpt_mutex);
 962  free_newinfo_counters_untrans:
 963         ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry, NULL);
 964  free_newinfo_counters:
 965         vfree(counters);
 966  free_newinfo:
 967         vfree(newinfo);
 968         return ret;
 969 }
 970
 971 /* We're lazy, and add to the first CPU; overflow works its fey magic
 972  * and everything is OK.
 973  */
 974 static inline int add_counter_to_entry(struct arpt_entry *e,
 975                                        const struct arpt_counters addme[],
 976                                        unsigned int *i)
 977 {
 978
 979         ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
 980
 981         (*i)++;
 982         return 0;
 983 }
 984
 985 static int do_add_counters(void __user *user, unsigned int len)
 986 {
 987         unsigned int i;
 988         struct arpt_counters_info tmp, *paddc;
 989         struct arpt_table *t;
 990         int ret;
 991
 992         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
 993                 return -EFAULT;
 994
 995         if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct arpt_counters))
 996                 return -EINVAL;
 997
 998         paddc = vmalloc(len);
 999         if (!paddc)
1000                 return -ENOMEM;
1001
1002         if (copy_from_user(paddc, user, len) != 0) {
1003                 ret = -EFAULT;
1004                 goto free;
1005         }
1006
1007         t = arpt_find_table_lock(tmp.name, &ret, &arpt_mutex);
1008         if (!t)
1009                 goto free;
1010
1011         write_lock_bh(&t->lock);
1012         if (t->private->number != paddc->num_counters) {
1013                 ret = -EINVAL;
1014                 goto unlock_up_free;
1015         }
1016
1017         i = 0;
1018         ARPT_ENTRY_ITERATE(t->private->entries,
1019                            t->private->size,
1020                            add_counter_to_entry,
1021                            paddc->counters,
1022                            &i);
1023  unlock_up_free:
1024         write_unlock_bh(&t->lock);
1025         up(&arpt_mutex);
1026  free:
1027         vfree(paddc);
1028
1029         return ret;
1030 }
1031
1032 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1033 {
1034         int ret;
1035
1036         if (!capable(CAP_NET_ADMIN))
1037                 return -EPERM;
1038
1039         switch (cmd) {
1040         case ARPT_SO_SET_REPLACE:
1041                 ret = do_replace(user, len);
1042                 break;
1043
1044         case ARPT_SO_SET_ADD_COUNTERS:
1045                 ret = do_add_counters(user, len);
1046                 break;
1047
1048         default:
1049                 duprintf("do_arpt_set_ctl:  unknown request %i\n", cmd);
1050                 ret = -EINVAL;
1051         }
1052
1053         return ret;
1054 }
1055
1056 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1057 {
1058         int ret;
1059
1060         if (!capable(CAP_NET_ADMIN))
1061                 return -EPERM;
1062
1063         switch (cmd) {
1064         case ARPT_SO_GET_INFO: {
1065                 char name[ARPT_TABLE_MAXNAMELEN];
1066                 struct arpt_table *t;
1067
1068                 if (*len != sizeof(struct arpt_getinfo)) {
1069                         duprintf("length %u != %Zu\n", *len,
1070                                  sizeof(struct arpt_getinfo));
1071                         ret = -EINVAL;
1072                         break;
1073                 }
1074
1075                 if (copy_from_user(name, user, sizeof(name)) != 0) {
1076                         ret = -EFAULT;
1077                         break;
1078                 }
1079                 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
1080                 t = arpt_find_table_lock(name, &ret, &arpt_mutex);
1081                 if (t) {
1082                         struct arpt_getinfo info;
1083
1084                         info.valid_hooks = t->valid_hooks;
1085                         memcpy(info.hook_entry, t->private->hook_entry,
1086                                sizeof(info.hook_entry));
1087                         memcpy(info.underflow, t->private->underflow,
1088                                sizeof(info.underflow));
1089                         info.num_entries = t->private->number;
1090                         info.size = t->private->size;
1091                         strcpy(info.name, name);
1092
1093                         if (copy_to_user(user, &info, *len) != 0)
1094                                 ret = -EFAULT;
1095                         else
1096                                 ret = 0;
1097
1098                         up(&arpt_mutex);
1099                 }
1100         }
1101         break;
1102
1103         case ARPT_SO_GET_ENTRIES: {
1104                 struct arpt_get_entries get;
1105
1106                 if (*len < sizeof(get)) {
1107                         duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
1108                         ret = -EINVAL;
1109                 } else if (copy_from_user(&get, user, sizeof(get)) != 0) {
1110                         ret = -EFAULT;
1111                 } else if (*len != sizeof(struct arpt_get_entries) + get.size) {
1112                         duprintf("get_entries: %u != %Zu\n", *len,
1113                                  sizeof(struct arpt_get_entries) + get.size);
1114                         ret = -EINVAL;
1115                 } else
1116                         ret = get_entries(&get, user);
1117                 break;
1118         }
1119
1120         default:
1121                 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1122                 ret = -EINVAL;
1123         }
1124
1125         return ret;
1126 }
1127
1128 /* Registration hooks for targets. */
1129 int arpt_register_target(struct arpt_target *target)
1130 {
1131         int ret;
1132
1133         ret = down_interruptible(&arpt_mutex);
1134         if (ret != 0)
1135                 return ret;
1136
1137         if (!list_named_insert(&arpt_target, target)) {
1138                 duprintf("arpt_register_target: `%s' already in list!\n",
1139                          target->name);
1140                 ret = -EINVAL;
1141         }
1142         up(&arpt_mutex);
1143         return ret;
1144 }
1145
1146 void arpt_unregister_target(struct arpt_target *target)
1147 {
1148         down(&arpt_mutex);
1149         LIST_DELETE(&arpt_target, target);
1150         up(&arpt_mutex);
1151 }
1152
1153 int arpt_register_table(struct arpt_table *table,
1154                         const struct arpt_replace *repl)
1155 {
1156         int ret;
1157         struct arpt_table_info *newinfo;
1158         static struct arpt_table_info bootstrap
1159                 = { 0, 0, 0, { 0 }, { 0 }, { } };
1160
1161         newinfo = vmalloc(sizeof(struct arpt_table_info)
1162                           + SMP_ALIGN(repl->size) * num_possible_cpus());
1163         if (!newinfo) {
1164                 ret = -ENOMEM;
1165                 return ret;
1166         }
1167         memcpy(newinfo->entries, repl->entries, repl->size);
1168
1169         ret = translate_table(table->name, table->valid_hooks,
1170                               newinfo, repl->size,
1171                               repl->num_entries,
1172                               repl->hook_entry,
1173                               repl->underflow);
1174         duprintf("arpt_register_table: translate table gives %d\n", ret);
1175         if (ret != 0) {
1176                 vfree(newinfo);
1177                 return ret;
1178         }
1179
1180         ret = down_interruptible(&arpt_mutex);
1181         if (ret != 0) {
1182                 vfree(newinfo);
1183                 return ret;
1184         }
1185
1186         /* Don't autoload: we'd eat our tail... */
1187         if (list_named_find(&arpt_tables, table->name)) {
1188                 ret = -EEXIST;
1189                 goto free_unlock;
1190         }
1191
1192         /* Simplifies replace_table code. */
1193         table->private = &bootstrap;
1194         if (!replace_table(table, 0, newinfo, &ret))
1195                 goto free_unlock;
1196
1197         duprintf("table->private->number = %u\n",
1198                  table->private->number);
1199
1200         /* save number of initial entries */
1201         table->private->initial_entries = table->private->number;
1202
1203         rwlock_init(&table->lock);
1204         list_prepend(&arpt_tables, table);
1205
1206  unlock:
1207         up(&arpt_mutex);
1208         return ret;
1209
1210  free_unlock:
1211         vfree(newinfo);
1212         goto unlock;
1213 }
1214
1215 void arpt_unregister_table(struct arpt_table *table)
1216 {
1217         down(&arpt_mutex);
1218         LIST_DELETE(&arpt_tables, table);
1219         up(&arpt_mutex);
1220
1221         /* Decrease module usage counts and free resources */
1222         ARPT_ENTRY_ITERATE(table->private->entries, table->private->size,
1223                            cleanup_entry, NULL);
1224         vfree(table->private);
1225 }
1226
1227 /* The built-in targets: standard (NULL) and error. */
1228 static struct arpt_target arpt_standard_target = {
1229         .name           = ARPT_STANDARD_TARGET,
1230 };
1231
1232 static struct arpt_target arpt_error_target = {
1233         .name           = ARPT_ERROR_TARGET,
1234         .target         = arpt_error,
1235 };
1236
1237 static struct nf_sockopt_ops arpt_sockopts = {
1238         .pf             = PF_INET,
1239         .set_optmin     = ARPT_BASE_CTL,
1240         .set_optmax     = ARPT_SO_SET_MAX+1,
1241         .set            = do_arpt_set_ctl,
1242         .get_optmin     = ARPT_BASE_CTL,
1243         .get_optmax     = ARPT_SO_GET_MAX+1,
1244         .get            = do_arpt_get_ctl,
1245 };
1246
1247 #ifdef CONFIG_PROC_FS
1248 static inline int print_name(const struct arpt_table *t,
1249                              off_t start_offset, char *buffer, int length,
1250                              off_t *pos, unsigned int *count)
1251 {
1252         if ((*count)++ >= start_offset) {
1253                 unsigned int namelen;
1254
1255                 namelen = sprintf(buffer + *pos, "%s\n", t->name);
1256                 if (*pos + namelen > length) {
1257                         /* Stop iterating */
1258                         return 1;
1259                 }
1260                 *pos += namelen;
1261         }
1262         return 0;
1263 }
1264
1265 static int arpt_get_tables(char *buffer, char **start, off_t offset, int length)
1266 {
1267         off_t pos = 0;
1268         unsigned int count = 0;
1269
1270         if (down_interruptible(&arpt_mutex) != 0)
1271                 return 0;
1272
1273         LIST_FIND(&arpt_tables, print_name, struct arpt_table *,
1274                   offset, buffer, length, &pos, &count);
1275
1276         up(&arpt_mutex);
1277
1278         /* `start' hack - see fs/proc/generic.c line ~105 */
1279         *start=(char *)((unsigned long)count-offset);
1280         return pos;
1281 }
1282 #endif /*CONFIG_PROC_FS*/
1283
1284 static int __init init(void)
1285 {
1286         int ret;
1287
1288         /* Noone else will be downing sem now, so we won't sleep */
1289         down(&arpt_mutex);
1290         list_append(&arpt_target, &arpt_standard_target);
1291         list_append(&arpt_target, &arpt_error_target);
1292         up(&arpt_mutex);
1293
1294         /* Register setsockopt */
1295         ret = nf_register_sockopt(&arpt_sockopts);
1296         if (ret < 0) {
1297                 duprintf("Unable to register sockopts.\n");
1298                 return ret;
1299         }
1300
1301 #ifdef CONFIG_PROC_FS
1302         {
1303                 struct proc_dir_entry *proc;
1304
1305                 proc = proc_net_create("arp_tables_names", 0, arpt_get_tables);
1306                 if (!proc) {
1307                         nf_unregister_sockopt(&arpt_sockopts);
1308                         return -ENOMEM;
1309                 }
1310                 proc->owner = THIS_MODULE;
1311         }
1312 #endif
1313
1314         printk("arp_tables: (C) 2002 David S. Miller\n");
1315         return 0;
1316 }
1317
1318 static void __exit fini(void)
1319 {
1320         nf_unregister_sockopt(&arpt_sockopts);
1321 #ifdef CONFIG_PROC_FS
1322         proc_net_remove("arp_tables_names");
1323 #endif
1324 }
1325
1326 EXPORT_SYMBOL(arpt_register_table);
1327 EXPORT_SYMBOL(arpt_unregister_table);
1328 EXPORT_SYMBOL(arpt_do_table);
1329 EXPORT_SYMBOL(arpt_register_target);
1330 EXPORT_SYMBOL(arpt_unregister_target);
1331
1332 module_init(init);
1333 module_exit(fini);