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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/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_each_cpu(i) {
 720                 if (i == 0)
 721                         continue;
 722                 memcpy(newinfo->entries + SMP_ALIGN(newinfo->size) * i,
 723                        newinfo->entries,
 724                        SMP_ALIGN(newinfo->size));
 725         }
 726
 727         return ret;
 728 }
 729
 730 static struct arpt_table_info *replace_table(struct arpt_table *table,
 731                                              unsigned int num_counters,
 732                                              struct arpt_table_info *newinfo,
 733                                              int *error)
 734 {
 735         struct arpt_table_info *oldinfo;
 736
 737         /* Do the substitution. */
 738         write_lock_bh(&table->lock);
 739         /* Check inside lock: is the old number correct? */
 740         if (num_counters != table->private->number) {
 741                 duprintf("num_counters != table->private->number (%u/%u)\n",
 742                          num_counters, table->private->number);
 743                 write_unlock_bh(&table->lock);
 744                 *error = -EAGAIN;
 745                 return NULL;
 746         }
 747         oldinfo = table->private;
 748         table->private = newinfo;
 749         newinfo->initial_entries = oldinfo->initial_entries;
 750         write_unlock_bh(&table->lock);
 751
 752         return oldinfo;
 753 }
 754
 755 /* Gets counters. */
 756 static inline int add_entry_to_counter(const struct arpt_entry *e,
 757                                        struct arpt_counters total[],
 758                                        unsigned int *i)
 759 {
 760         ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
 761
 762         (*i)++;
 763         return 0;
 764 }
 765
 766 static void get_counters(const struct arpt_table_info *t,
 767                          struct arpt_counters counters[])
 768 {
 769         unsigned int cpu;
 770         unsigned int i;
 771
 772         for_each_cpu(cpu) {
 773                 i = 0;
 774                 ARPT_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu),
 775                                    t->size,
 776                                    add_entry_to_counter,
 777                                    counters,
 778                                    &i);
 779         }
 780 }
 781
 782 static int copy_entries_to_user(unsigned int total_size,
 783                                 struct arpt_table *table,
 784                                 void __user *userptr)
 785 {
 786         unsigned int off, num, countersize;
 787         struct arpt_entry *e;
 788         struct arpt_counters *counters;
 789         int ret = 0;
 790
 791         /* We need atomic snapshot of counters: rest doesn't change
 792          * (other than comefrom, which userspace doesn't care
 793          * about).
 794          */
 795         countersize = sizeof(struct arpt_counters) * table->private->number;
 796         counters = vmalloc(countersize);
 797
 798         if (counters == NULL)
 799                 return -ENOMEM;
 800
 801         /* First, sum counters... */
 802         memset(counters, 0, countersize);
 803         write_lock_bh(&table->lock);
 804         get_counters(table->private, counters);
 805         write_unlock_bh(&table->lock);
 806
 807         /* ... then copy entire thing from CPU 0... */
 808         if (copy_to_user(userptr, table->private->entries, total_size) != 0) {
 809                 ret = -EFAULT;
 810                 goto free_counters;
 811         }
 812
 813         /* FIXME: use iterator macros --RR */
 814         /* ... then go back and fix counters and names */
 815         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
 816                 struct arpt_entry_target *t;
 817
 818                 e = (struct arpt_entry *)(table->private->entries + off);
 819                 if (copy_to_user(userptr + off
 820                                  + offsetof(struct arpt_entry, counters),
 821                                  &counters[num],
 822                                  sizeof(counters[num])) != 0) {
 823                         ret = -EFAULT;
 824                         goto free_counters;
 825                 }
 826
 827                 t = arpt_get_target(e);
 828                 if (copy_to_user(userptr + off + e->target_offset
 829                                  + offsetof(struct arpt_entry_target,
 830                                             u.user.name),
 831                                  t->u.kernel.target->name,
 832                                  strlen(t->u.kernel.target->name)+1) != 0) {
 833                         ret = -EFAULT;
 834                         goto free_counters;
 835                 }
 836         }
 837
 838  free_counters:
 839         vfree(counters);
 840         return ret;
 841 }
 842
 843 static int get_entries(const struct arpt_get_entries *entries,
 844                        struct arpt_get_entries __user *uptr)
 845 {
 846         int ret;
 847         struct arpt_table *t;
 848
 849         t = arpt_find_table_lock(entries->name, &ret, &arpt_mutex);
 850         if (t) {
 851                 duprintf("t->private->number = %u\n",
 852                          t->private->number);
 853                 if (entries->size == t->private->size)
 854                         ret = copy_entries_to_user(t->private->size,
 855                                                    t, uptr->entrytable);
 856                 else {
 857                         duprintf("get_entries: I've got %u not %u!\n",
 858                                  t->private->size,
 859                                  entries->size);
 860                         ret = -EINVAL;
 861                 }
 862                 up(&arpt_mutex);
 863         } else
 864                 duprintf("get_entries: Can't find %s!\n",
 865                          entries->name);
 866
 867         return ret;
 868 }
 869
 870 static int do_replace(void __user *user, unsigned int len)
 871 {
 872         int ret;
 873         struct arpt_replace tmp;
 874         struct arpt_table *t;
 875         struct arpt_table_info *newinfo, *oldinfo;
 876         struct arpt_counters *counters;
 877
 878         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
 879                 return -EFAULT;
 880
 881         /* Hack: Causes ipchains to give correct error msg --RR */
 882         if (len != sizeof(tmp) + tmp.size)
 883                 return -ENOPROTOOPT;
 884
 885         /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
 886         if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages)
 887                 return -ENOMEM;
 888
 889         newinfo = vmalloc(sizeof(struct arpt_table_info)
 890                           + SMP_ALIGN(tmp.size) *
 891                                         (highest_possible_processor_id()+1));
 892         if (!newinfo)
 893                 return -ENOMEM;
 894
 895         if (copy_from_user(newinfo->entries, user + sizeof(tmp),
 896                            tmp.size) != 0) {
 897                 ret = -EFAULT;
 898                 goto free_newinfo;
 899         }
 900
 901         counters = vmalloc(tmp.num_counters * sizeof(struct arpt_counters));
 902         if (!counters) {
 903                 ret = -ENOMEM;
 904                 goto free_newinfo;
 905         }
 906         memset(counters, 0, tmp.num_counters * sizeof(struct arpt_counters));
 907
 908         ret = translate_table(tmp.name, tmp.valid_hooks,
 909                               newinfo, tmp.size, tmp.num_entries,
 910                               tmp.hook_entry, tmp.underflow);
 911         if (ret != 0)
 912                 goto free_newinfo_counters;
 913
 914         duprintf("arp_tables: Translated table\n");
 915
 916         t = arpt_find_table_lock(tmp.name, &ret, &arpt_mutex);
 917         if (!t)
 918                 goto free_newinfo_counters_untrans;
 919
 920         /* You lied! */
 921         if (tmp.valid_hooks != t->valid_hooks) {
 922                 duprintf("Valid hook crap: %08X vs %08X\n",
 923                          tmp.valid_hooks, t->valid_hooks);
 924                 ret = -EINVAL;
 925                 goto free_newinfo_counters_untrans_unlock;
 926         }
 927
 928         /* Get a reference in advance, we're not allowed fail later */
 929         if (!try_module_get(t->me)) {
 930                 ret = -EBUSY;
 931                 goto free_newinfo_counters_untrans_unlock;
 932         }
 933
 934         oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret);
 935         if (!oldinfo)
 936                 goto put_module;
 937
 938         /* Update module usage count based on number of rules */
 939         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
 940                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
 941         if ((oldinfo->number > oldinfo->initial_entries) ||
 942             (newinfo->number <= oldinfo->initial_entries))
 943                 module_put(t->me);
 944         if ((oldinfo->number > oldinfo->initial_entries) &&
 945             (newinfo->number <= oldinfo->initial_entries))
 946                 module_put(t->me);
 947
 948         /* Get the old counters. */
 949         get_counters(oldinfo, counters);
 950         /* Decrease module usage counts and free resource */
 951         ARPT_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL);
 952         vfree(oldinfo);
 953         if (copy_to_user(tmp.counters, counters,
 954                          sizeof(struct arpt_counters) * tmp.num_counters) != 0)
 955                 ret = -EFAULT;
 956         vfree(counters);
 957         up(&arpt_mutex);
 958         return ret;
 959
 960  put_module:
 961         module_put(t->me);
 962  free_newinfo_counters_untrans_unlock:
 963         up(&arpt_mutex);
 964  free_newinfo_counters_untrans:
 965         ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry, NULL);
 966  free_newinfo_counters:
 967         vfree(counters);
 968  free_newinfo:
 969         vfree(newinfo);
 970         return ret;
 971 }
 972
 973 /* We're lazy, and add to the first CPU; overflow works its fey magic
 974  * and everything is OK.
 975  */
 976 static inline int add_counter_to_entry(struct arpt_entry *e,
 977                                        const struct arpt_counters addme[],
 978                                        unsigned int *i)
 979 {
 980
 981         ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
 982
 983         (*i)++;
 984         return 0;
 985 }
 986
 987 static int do_add_counters(void __user *user, unsigned int len)
 988 {
 989         unsigned int i;
 990         struct arpt_counters_info tmp, *paddc;
 991         struct arpt_table *t;
 992         int ret;
 993
 994         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
 995                 return -EFAULT;
 996
 997         if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct arpt_counters))
 998                 return -EINVAL;
 999
1000         paddc = vmalloc(len);
1001         if (!paddc)
1002                 return -ENOMEM;
1003
1004         if (copy_from_user(paddc, user, len) != 0) {
1005                 ret = -EFAULT;
1006                 goto free;
1007         }
1008
1009         t = arpt_find_table_lock(tmp.name, &ret, &arpt_mutex);
1010         if (!t)
1011                 goto free;
1012
1013         write_lock_bh(&t->lock);
1014         if (t->private->number != paddc->num_counters) {
1015                 ret = -EINVAL;
1016                 goto unlock_up_free;
1017         }
1018
1019         i = 0;
1020         ARPT_ENTRY_ITERATE(t->private->entries,
1021                            t->private->size,
1022                            add_counter_to_entry,
1023                            paddc->counters,
1024                            &i);
1025  unlock_up_free:
1026         write_unlock_bh(&t->lock);
1027         up(&arpt_mutex);
1028  free:
1029         vfree(paddc);
1030
1031         return ret;
1032 }
1033
1034 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1035 {
1036         int ret;
1037
1038         if (!capable(CAP_NET_ADMIN))
1039                 return -EPERM;
1040
1041         switch (cmd) {
1042         case ARPT_SO_SET_REPLACE:
1043                 ret = do_replace(user, len);
1044                 break;
1045
1046         case ARPT_SO_SET_ADD_COUNTERS:
1047                 ret = do_add_counters(user, len);
1048                 break;
1049
1050         default:
1051                 duprintf("do_arpt_set_ctl:  unknown request %i\n", cmd);
1052                 ret = -EINVAL;
1053         }
1054
1055         return ret;
1056 }
1057
1058 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1059 {
1060         int ret;
1061
1062         if (!capable(CAP_NET_ADMIN))
1063                 return -EPERM;
1064
1065         switch (cmd) {
1066         case ARPT_SO_GET_INFO: {
1067                 char name[ARPT_TABLE_MAXNAMELEN];
1068                 struct arpt_table *t;
1069
1070                 if (*len != sizeof(struct arpt_getinfo)) {
1071                         duprintf("length %u != %Zu\n", *len,
1072                                  sizeof(struct arpt_getinfo));
1073                         ret = -EINVAL;
1074                         break;
1075                 }
1076
1077                 if (copy_from_user(name, user, sizeof(name)) != 0) {
1078                         ret = -EFAULT;
1079                         break;
1080                 }
1081                 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
1082                 t = arpt_find_table_lock(name, &ret, &arpt_mutex);
1083                 if (t) {
1084                         struct arpt_getinfo info;
1085
1086                         info.valid_hooks = t->valid_hooks;
1087                         memcpy(info.hook_entry, t->private->hook_entry,
1088                                sizeof(info.hook_entry));
1089                         memcpy(info.underflow, t->private->underflow,
1090                                sizeof(info.underflow));
1091                         info.num_entries = t->private->number;
1092                         info.size = t->private->size;
1093                         strcpy(info.name, name);
1094
1095                         if (copy_to_user(user, &info, *len) != 0)
1096                                 ret = -EFAULT;
1097                         else
1098                                 ret = 0;
1099
1100                         up(&arpt_mutex);
1101                 }
1102         }
1103         break;
1104
1105         case ARPT_SO_GET_ENTRIES: {
1106                 struct arpt_get_entries get;
1107
1108                 if (*len < sizeof(get)) {
1109                         duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
1110                         ret = -EINVAL;
1111                 } else if (copy_from_user(&get, user, sizeof(get)) != 0) {
1112                         ret = -EFAULT;
1113                 } else if (*len != sizeof(struct arpt_get_entries) + get.size) {
1114                         duprintf("get_entries: %u != %Zu\n", *len,
1115                                  sizeof(struct arpt_get_entries) + get.size);
1116                         ret = -EINVAL;
1117                 } else
1118                         ret = get_entries(&get, user);
1119                 break;
1120         }
1121
1122         default:
1123                 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1124                 ret = -EINVAL;
1125         }
1126
1127         return ret;
1128 }
1129
1130 /* Registration hooks for targets. */
1131 int arpt_register_target(struct arpt_target *target)
1132 {
1133         int ret;
1134
1135         ret = down_interruptible(&arpt_mutex);
1136         if (ret != 0)
1137                 return ret;
1138
1139         if (!list_named_insert(&arpt_target, target)) {
1140                 duprintf("arpt_register_target: `%s' already in list!\n",
1141                          target->name);
1142                 ret = -EINVAL;
1143         }
1144         up(&arpt_mutex);
1145         return ret;
1146 }
1147
1148 void arpt_unregister_target(struct arpt_target *target)
1149 {
1150         down(&arpt_mutex);
1151         LIST_DELETE(&arpt_target, target);
1152         up(&arpt_mutex);
1153 }
1154
1155 int arpt_register_table(struct arpt_table *table,
1156                         const struct arpt_replace *repl)
1157 {
1158         int ret;
1159         struct arpt_table_info *newinfo;
1160         static struct arpt_table_info bootstrap
1161                 = { 0, 0, 0, { 0 }, { 0 }, { } };
1162
1163         newinfo = vmalloc(sizeof(struct arpt_table_info)
1164                           + SMP_ALIGN(repl->size) *
1165                                         (highest_possible_processor_id()+1));
1166         if (!newinfo) {
1167                 ret = -ENOMEM;
1168                 return ret;
1169         }
1170         memcpy(newinfo->entries, repl->entries, repl->size);
1171
1172         ret = translate_table(table->name, table->valid_hooks,
1173                               newinfo, repl->size,
1174                               repl->num_entries,
1175                               repl->hook_entry,
1176                               repl->underflow);
1177         duprintf("arpt_register_table: translate table gives %d\n", ret);
1178         if (ret != 0) {
1179                 vfree(newinfo);
1180                 return ret;
1181         }
1182
1183         ret = down_interruptible(&arpt_mutex);
1184         if (ret != 0) {
1185                 vfree(newinfo);
1186                 return ret;
1187         }
1188
1189         /* Don't autoload: we'd eat our tail... */
1190         if (list_named_find(&arpt_tables, table->name)) {
1191                 ret = -EEXIST;
1192                 goto free_unlock;
1193         }
1194
1195         /* Simplifies replace_table code. */
1196         table->private = &bootstrap;
1197         if (!replace_table(table, 0, newinfo, &ret))
1198                 goto free_unlock;
1199
1200         duprintf("table->private->number = %u\n",
1201                  table->private->number);
1202
1203         /* save number of initial entries */
1204         table->private->initial_entries = table->private->number;
1205
1206         rwlock_init(&table->lock);
1207         list_prepend(&arpt_tables, table);
1208
1209  unlock:
1210         up(&arpt_mutex);
1211         return ret;
1212
1213  free_unlock:
1214         vfree(newinfo);
1215         goto unlock;
1216 }
1217
1218 void arpt_unregister_table(struct arpt_table *table)
1219 {
1220         down(&arpt_mutex);
1221         LIST_DELETE(&arpt_tables, table);
1222         up(&arpt_mutex);
1223
1224         /* Decrease module usage counts and free resources */
1225         ARPT_ENTRY_ITERATE(table->private->entries, table->private->size,
1226                            cleanup_entry, NULL);
1227         vfree(table->private);
1228 }
1229
1230 /* The built-in targets: standard (NULL) and error. */
1231 static struct arpt_target arpt_standard_target = {
1232         .name           = ARPT_STANDARD_TARGET,
1233 };
1234
1235 static struct arpt_target arpt_error_target = {
1236         .name           = ARPT_ERROR_TARGET,
1237         .target         = arpt_error,
1238 };
1239
1240 static struct nf_sockopt_ops arpt_sockopts = {
1241         .pf             = PF_INET,
1242         .set_optmin     = ARPT_BASE_CTL,
1243         .set_optmax     = ARPT_SO_SET_MAX+1,
1244         .set            = do_arpt_set_ctl,
1245         .get_optmin     = ARPT_BASE_CTL,
1246         .get_optmax     = ARPT_SO_GET_MAX+1,
1247         .get            = do_arpt_get_ctl,
1248 };
1249
1250 #ifdef CONFIG_PROC_FS
1251 static inline int print_name(const struct arpt_table *t,
1252                              off_t start_offset, char *buffer, int length,
1253                              off_t *pos, unsigned int *count)
1254 {
1255         if ((*count)++ >= start_offset) {
1256                 unsigned int namelen;
1257
1258                 namelen = sprintf(buffer + *pos, "%s\n", t->name);
1259                 if (*pos + namelen > length) {
1260                         /* Stop iterating */
1261                         return 1;
1262                 }
1263                 *pos += namelen;
1264         }
1265         return 0;
1266 }
1267
1268 static int arpt_get_tables(char *buffer, char **start, off_t offset, int length)
1269 {
1270         off_t pos = 0;
1271         unsigned int count = 0;
1272
1273         if (down_interruptible(&arpt_mutex) != 0)
1274                 return 0;
1275
1276         LIST_FIND(&arpt_tables, print_name, struct arpt_table *,
1277                   offset, buffer, length, &pos, &count);
1278
1279         up(&arpt_mutex);
1280
1281         /* `start' hack - see fs/proc/generic.c line ~105 */
1282         *start=(char *)((unsigned long)count-offset);
1283         return pos;
1284 }
1285 #endif /*CONFIG_PROC_FS*/
1286
1287 static int __init init(void)
1288 {
1289         int ret;
1290
1291         /* Noone else will be downing sem now, so we won't sleep */
1292         down(&arpt_mutex);
1293         list_append(&arpt_target, &arpt_standard_target);
1294         list_append(&arpt_target, &arpt_error_target);
1295         up(&arpt_mutex);
1296
1297         /* Register setsockopt */
1298         ret = nf_register_sockopt(&arpt_sockopts);
1299         if (ret < 0) {
1300                 duprintf("Unable to register sockopts.\n");
1301                 return ret;
1302         }
1303
1304 #ifdef CONFIG_PROC_FS
1305         {
1306                 struct proc_dir_entry *proc;
1307
1308                 proc = proc_net_create("arp_tables_names", 0, arpt_get_tables);
1309                 if (!proc) {
1310                         nf_unregister_sockopt(&arpt_sockopts);
1311                         return -ENOMEM;
1312                 }
1313                 proc->owner = THIS_MODULE;
1314         }
1315 #endif
1316
1317         printk("arp_tables: (C) 2002 David S. Miller\n");
1318         return 0;
1319 }
1320
1321 static void __exit fini(void)
1322 {
1323         nf_unregister_sockopt(&arpt_sockopts);
1324 #ifdef CONFIG_PROC_FS
1325         proc_net_remove("arp_tables_names");
1326 #endif
1327 }
1328
1329 EXPORT_SYMBOL(arpt_register_table);
1330 EXPORT_SYMBOL(arpt_unregister_table);
1331 EXPORT_SYMBOL(arpt_do_table);
1332 EXPORT_SYMBOL(arpt_register_target);
1333 EXPORT_SYMBOL(arpt_unregister_target);
1334
1335 module_init(init);
1336 module_exit(fini);