net/netfilter/x_tables.c

   1 /*
   2  * x_tables core - Backend for {ip,ip6,arp}_tables
   3  *
   4  * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
   5  *
   6  * Based on existing ip_tables code which is
   7  *   Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
   8  *   Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/socket.h>
  18 #include <linux/net.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/seq_file.h>
  21 #include <linux/string.h>
  22 #include <linux/vmalloc.h>
  23 #include <linux/mutex.h>
  24
  25 #include <linux/netfilter/x_tables.h>
  26 #include <linux/netfilter_arp.h>
  27
  28
  29 MODULE_LICENSE("GPL");
  30 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
  31 MODULE_DESCRIPTION("[ip,ip6,arp]_tables backend module");
  32
  33 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
  34
  35 struct xt_af {
  36         struct mutex mutex;
  37         struct list_head match;
  38         struct list_head target;
  39         struct list_head tables;
  40         struct mutex compat_mutex;
  41 };
  42
  43 static struct xt_af *xt;
  44
  45 #ifdef DEBUG_IP_FIREWALL_USER
  46 #define duprintf(format, args...) printk(format , ## args)
  47 #else
  48 #define duprintf(format, args...)
  49 #endif
  50
  51 enum {
  52         TABLE,
  53         TARGET,
  54         MATCH,
  55 };
  56
  57 static const char *xt_prefix[NPROTO] = {
  58         [AF_INET]       = "ip",
  59         [AF_INET6]      = "ip6",
  60         [NF_ARP]        = "arp",
  61 };
  62
  63 /* Registration hooks for targets. */
  64 int
  65 xt_register_target(struct xt_target *target)
  66 {
  67         int ret, af = target->family;
  68
  69         ret = mutex_lock_interruptible(&xt[af].mutex);
  70         if (ret != 0)
  71                 return ret;
  72         list_add(&target->list, &xt[af].target);
  73         mutex_unlock(&xt[af].mutex);
  74         return ret;
  75 }
  76 EXPORT_SYMBOL(xt_register_target);
  77
  78 void
  79 xt_unregister_target(struct xt_target *target)
  80 {
  81         int af = target->family;
  82
  83         mutex_lock(&xt[af].mutex);
  84         list_del(&target->list);
  85         mutex_unlock(&xt[af].mutex);
  86 }
  87 EXPORT_SYMBOL(xt_unregister_target);
  88
  89 int
  90 xt_register_targets(struct xt_target *target, unsigned int n)
  91 {
  92         unsigned int i;
  93         int err = 0;
  94
  95         for (i = 0; i < n; i++) {
  96                 err = xt_register_target(&target[i]);
  97                 if (err)
  98                         goto err;
  99         }
 100         return err;
 101
 102 err:
 103         if (i > 0)
 104                 xt_unregister_targets(target, i);
 105         return err;
 106 }
 107 EXPORT_SYMBOL(xt_register_targets);
 108
 109 void
 110 xt_unregister_targets(struct xt_target *target, unsigned int n)
 111 {
 112         unsigned int i;
 113
 114         for (i = 0; i < n; i++)
 115                 xt_unregister_target(&target[i]);
 116 }
 117 EXPORT_SYMBOL(xt_unregister_targets);
 118
 119 int
 120 xt_register_match(struct xt_match *match)
 121 {
 122         int ret, af = match->family;
 123
 124         ret = mutex_lock_interruptible(&xt[af].mutex);
 125         if (ret != 0)
 126                 return ret;
 127
 128         list_add(&match->list, &xt[af].match);
 129         mutex_unlock(&xt[af].mutex);
 130
 131         return ret;
 132 }
 133 EXPORT_SYMBOL(xt_register_match);
 134
 135 void
 136 xt_unregister_match(struct xt_match *match)
 137 {
 138         int af =  match->family;
 139
 140         mutex_lock(&xt[af].mutex);
 141         list_del(&match->list);
 142         mutex_unlock(&xt[af].mutex);
 143 }
 144 EXPORT_SYMBOL(xt_unregister_match);
 145
 146 int
 147 xt_register_matches(struct xt_match *match, unsigned int n)
 148 {
 149         unsigned int i;
 150         int err = 0;
 151
 152         for (i = 0; i < n; i++) {
 153                 err = xt_register_match(&match[i]);
 154                 if (err)
 155                         goto err;
 156         }
 157         return err;
 158
 159 err:
 160         if (i > 0)
 161                 xt_unregister_matches(match, i);
 162         return err;
 163 }
 164 EXPORT_SYMBOL(xt_register_matches);
 165
 166 void
 167 xt_unregister_matches(struct xt_match *match, unsigned int n)
 168 {
 169         unsigned int i;
 170
 171         for (i = 0; i < n; i++)
 172                 xt_unregister_match(&match[i]);
 173 }
 174 EXPORT_SYMBOL(xt_unregister_matches);
 175
 176
 177 /*
 178  * These are weird, but module loading must not be done with mutex
 179  * held (since they will register), and we have to have a single
 180  * function to use try_then_request_module().
 181  */
 182
 183 /* Find match, grabs ref.  Returns ERR_PTR() on error. */
 184 struct xt_match *xt_find_match(int af, const char *name, u8 revision)
 185 {
 186         struct xt_match *m;
 187         int err = 0;
 188
 189         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 190                 return ERR_PTR(-EINTR);
 191
 192         list_for_each_entry(m, &xt[af].match, list) {
 193                 if (strcmp(m->name, name) == 0) {
 194                         if (m->revision == revision) {
 195                                 if (try_module_get(m->me)) {
 196                                         mutex_unlock(&xt[af].mutex);
 197                                         return m;
 198                                 }
 199                         } else
 200                                 err = -EPROTOTYPE; /* Found something. */
 201                 }
 202         }
 203         mutex_unlock(&xt[af].mutex);
 204         return ERR_PTR(err);
 205 }
 206 EXPORT_SYMBOL(xt_find_match);
 207
 208 /* Find target, grabs ref.  Returns ERR_PTR() on error. */
 209 struct xt_target *xt_find_target(int af, const char *name, u8 revision)
 210 {
 211         struct xt_target *t;
 212         int err = 0;
 213
 214         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 215                 return ERR_PTR(-EINTR);
 216
 217         list_for_each_entry(t, &xt[af].target, list) {
 218                 if (strcmp(t->name, name) == 0) {
 219                         if (t->revision == revision) {
 220                                 if (try_module_get(t->me)) {
 221                                         mutex_unlock(&xt[af].mutex);
 222                                         return t;
 223                                 }
 224                         } else
 225                                 err = -EPROTOTYPE; /* Found something. */
 226                 }
 227         }
 228         mutex_unlock(&xt[af].mutex);
 229         return ERR_PTR(err);
 230 }
 231 EXPORT_SYMBOL(xt_find_target);
 232
 233 struct xt_target *xt_request_find_target(int af, const char *name, u8 revision)
 234 {
 235         struct xt_target *target;
 236
 237         target = try_then_request_module(xt_find_target(af, name, revision),
 238                                          "%st_%s", xt_prefix[af], name);
 239         if (IS_ERR(target) || !target)
 240                 return NULL;
 241         return target;
 242 }
 243 EXPORT_SYMBOL_GPL(xt_request_find_target);
 244
 245 static int match_revfn(int af, const char *name, u8 revision, int *bestp)
 246 {
 247         struct xt_match *m;
 248         int have_rev = 0;
 249
 250         list_for_each_entry(m, &xt[af].match, list) {
 251                 if (strcmp(m->name, name) == 0) {
 252                         if (m->revision > *bestp)
 253                                 *bestp = m->revision;
 254                         if (m->revision == revision)
 255                                 have_rev = 1;
 256                 }
 257         }
 258         return have_rev;
 259 }
 260
 261 static int target_revfn(int af, const char *name, u8 revision, int *bestp)
 262 {
 263         struct xt_target *t;
 264         int have_rev = 0;
 265
 266         list_for_each_entry(t, &xt[af].target, list) {
 267                 if (strcmp(t->name, name) == 0) {
 268                         if (t->revision > *bestp)
 269                                 *bestp = t->revision;
 270                         if (t->revision == revision)
 271                                 have_rev = 1;
 272                 }
 273         }
 274         return have_rev;
 275 }
 276
 277 /* Returns true or false (if no such extension at all) */
 278 int xt_find_revision(int af, const char *name, u8 revision, int target,
 279                      int *err)
 280 {
 281         int have_rev, best = -1;
 282
 283         if (mutex_lock_interruptible(&xt[af].mutex) != 0) {
 284                 *err = -EINTR;
 285                 return 1;
 286         }
 287         if (target == 1)
 288                 have_rev = target_revfn(af, name, revision, &best);
 289         else
 290                 have_rev = match_revfn(af, name, revision, &best);
 291         mutex_unlock(&xt[af].mutex);
 292
 293         /* Nothing at all?  Return 0 to try loading module. */
 294         if (best == -1) {
 295                 *err = -ENOENT;
 296                 return 0;
 297         }
 298
 299         *err = best;
 300         if (!have_rev)
 301                 *err = -EPROTONOSUPPORT;
 302         return 1;
 303 }
 304 EXPORT_SYMBOL_GPL(xt_find_revision);
 305
 306 int xt_check_match(const struct xt_match *match, unsigned short family,
 307                    unsigned int size, const char *table, unsigned int hook_mask,
 308                    unsigned short proto, int inv_proto)
 309 {
 310         if (XT_ALIGN(match->matchsize) != size) {
 311                 printk("%s_tables: %s match: invalid size %Zu != %u\n",
 312                        xt_prefix[family], match->name,
 313                        XT_ALIGN(match->matchsize), size);
 314                 return -EINVAL;
 315         }
 316         if (match->table && strcmp(match->table, table)) {
 317                 printk("%s_tables: %s match: only valid in %s table, not %s\n",
 318                        xt_prefix[family], match->name, match->table, table);
 319                 return -EINVAL;
 320         }
 321         if (match->hooks && (hook_mask & ~match->hooks) != 0) {
 322                 printk("%s_tables: %s match: bad hook_mask %u\n",
 323                        xt_prefix[family], match->name, hook_mask);
 324                 return -EINVAL;
 325         }
 326         if (match->proto && (match->proto != proto || inv_proto)) {
 327                 printk("%s_tables: %s match: only valid for protocol %u\n",
 328                        xt_prefix[family], match->name, match->proto);
 329                 return -EINVAL;
 330         }
 331         return 0;
 332 }
 333 EXPORT_SYMBOL_GPL(xt_check_match);
 334
 335 #ifdef CONFIG_COMPAT
 336 int xt_compat_match_offset(struct xt_match *match)
 337 {
 338         u_int16_t csize = match->compatsize ? : match->matchsize;
 339         return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
 340 }
 341 EXPORT_SYMBOL_GPL(xt_compat_match_offset);
 342
 343 void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
 344                                int *size)
 345 {
 346         struct xt_match *match = m->u.kernel.match;
 347         struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
 348         int pad, off = xt_compat_match_offset(match);
 349         u_int16_t msize = cm->u.user.match_size;
 350
 351         m = *dstptr;
 352         memcpy(m, cm, sizeof(*cm));
 353         if (match->compat_from_user)
 354                 match->compat_from_user(m->data, cm->data);
 355         else
 356                 memcpy(m->data, cm->data, msize - sizeof(*cm));
 357         pad = XT_ALIGN(match->matchsize) - match->matchsize;
 358         if (pad > 0)
 359                 memset(m->data + match->matchsize, 0, pad);
 360
 361         msize += off;
 362         m->u.user.match_size = msize;
 363
 364         *size += off;
 365         *dstptr += msize;
 366 }
 367 EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
 368
 369 int xt_compat_match_to_user(struct xt_entry_match *m, void __user **dstptr,
 370                             int *size)
 371 {
 372         struct xt_match *match = m->u.kernel.match;
 373         struct compat_xt_entry_match __user *cm = *dstptr;
 374         int off = xt_compat_match_offset(match);
 375         u_int16_t msize = m->u.user.match_size - off;
 376
 377         if (copy_to_user(cm, m, sizeof(*cm)) ||
 378             put_user(msize, &cm->u.user.match_size))
 379                 return -EFAULT;
 380
 381         if (match->compat_to_user) {
 382                 if (match->compat_to_user((void __user *)cm->data, m->data))
 383                         return -EFAULT;
 384         } else {
 385                 if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
 386                         return -EFAULT;
 387         }
 388
 389         *size -= off;
 390         *dstptr += msize;
 391         return 0;
 392 }
 393 EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
 394 #endif /* CONFIG_COMPAT */
 395
 396 int xt_check_target(const struct xt_target *target, unsigned short family,
 397                     unsigned int size, const char *table, unsigned int hook_mask,
 398                     unsigned short proto, int inv_proto)
 399 {
 400         if (XT_ALIGN(target->targetsize) != size) {
 401                 printk("%s_tables: %s target: invalid size %Zu != %u\n",
 402                        xt_prefix[family], target->name,
 403                        XT_ALIGN(target->targetsize), size);
 404                 return -EINVAL;
 405         }
 406         if (target->table && strcmp(target->table, table)) {
 407                 printk("%s_tables: %s target: only valid in %s table, not %s\n",
 408                        xt_prefix[family], target->name, target->table, table);
 409                 return -EINVAL;
 410         }
 411         if (target->hooks && (hook_mask & ~target->hooks) != 0) {
 412                 printk("%s_tables: %s target: bad hook_mask %u\n",
 413                        xt_prefix[family], target->name, hook_mask);
 414                 return -EINVAL;
 415         }
 416         if (target->proto && (target->proto != proto || inv_proto)) {
 417                 printk("%s_tables: %s target: only valid for protocol %u\n",
 418                        xt_prefix[family], target->name, target->proto);
 419                 return -EINVAL;
 420         }
 421         return 0;
 422 }
 423 EXPORT_SYMBOL_GPL(xt_check_target);
 424
 425 #ifdef CONFIG_COMPAT
 426 int xt_compat_target_offset(struct xt_target *target)
 427 {
 428         u_int16_t csize = target->compatsize ? : target->targetsize;
 429         return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
 430 }
 431 EXPORT_SYMBOL_GPL(xt_compat_target_offset);
 432
 433 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
 434                                 int *size)
 435 {
 436         struct xt_target *target = t->u.kernel.target;
 437         struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
 438         int pad, off = xt_compat_target_offset(target);
 439         u_int16_t tsize = ct->u.user.target_size;
 440
 441         t = *dstptr;
 442         memcpy(t, ct, sizeof(*ct));
 443         if (target->compat_from_user)
 444                 target->compat_from_user(t->data, ct->data);
 445         else
 446                 memcpy(t->data, ct->data, tsize - sizeof(*ct));
 447         pad = XT_ALIGN(target->targetsize) - target->targetsize;
 448         if (pad > 0)
 449                 memset(t->data + target->targetsize, 0, pad);
 450
 451         tsize += off;
 452         t->u.user.target_size = tsize;
 453
 454         *size += off;
 455         *dstptr += tsize;
 456 }
 457 EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
 458
 459 int xt_compat_target_to_user(struct xt_entry_target *t, void __user **dstptr,
 460                              int *size)
 461 {
 462         struct xt_target *target = t->u.kernel.target;
 463         struct compat_xt_entry_target __user *ct = *dstptr;
 464         int off = xt_compat_target_offset(target);
 465         u_int16_t tsize = t->u.user.target_size - off;
 466
 467         if (copy_to_user(ct, t, sizeof(*ct)) ||
 468             put_user(tsize, &ct->u.user.target_size))
 469                 return -EFAULT;
 470
 471         if (target->compat_to_user) {
 472                 if (target->compat_to_user((void __user *)ct->data, t->data))
 473                         return -EFAULT;
 474         } else {
 475                 if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
 476                         return -EFAULT;
 477         }
 478
 479         *size -= off;
 480         *dstptr += tsize;
 481         return 0;
 482 }
 483 EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
 484 #endif
 485
 486 struct xt_table_info *xt_alloc_table_info(unsigned int size)
 487 {
 488         struct xt_table_info *newinfo;
 489         int cpu;
 490
 491         /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
 492         if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
 493                 return NULL;
 494
 495         newinfo = kzalloc(sizeof(struct xt_table_info), GFP_KERNEL);
 496         if (!newinfo)
 497                 return NULL;
 498
 499         newinfo->size = size;
 500
 501         for_each_possible_cpu(cpu) {
 502                 if (size <= PAGE_SIZE)
 503                         newinfo->entries[cpu] = kmalloc_node(size,
 504                                                         GFP_KERNEL,
 505                                                         cpu_to_node(cpu));
 506                 else
 507                         newinfo->entries[cpu] = vmalloc_node(size,
 508                                                         cpu_to_node(cpu));
 509
 510                 if (newinfo->entries[cpu] == NULL) {
 511                         xt_free_table_info(newinfo);
 512                         return NULL;
 513                 }
 514         }
 515
 516         return newinfo;
 517 }
 518 EXPORT_SYMBOL(xt_alloc_table_info);
 519
 520 void xt_free_table_info(struct xt_table_info *info)
 521 {
 522         int cpu;
 523
 524         for_each_possible_cpu(cpu) {
 525                 if (info->size <= PAGE_SIZE)
 526                         kfree(info->entries[cpu]);
 527                 else
 528                         vfree(info->entries[cpu]);
 529         }
 530         kfree(info);
 531 }
 532 EXPORT_SYMBOL(xt_free_table_info);
 533
 534 /* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
 535 struct xt_table *xt_find_table_lock(int af, const char *name)
 536 {
 537         struct xt_table *t;
 538
 539         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 540                 return ERR_PTR(-EINTR);
 541
 542         list_for_each_entry(t, &xt[af].tables, list)
 543                 if (strcmp(t->name, name) == 0 && try_module_get(t->me))
 544                         return t;
 545         mutex_unlock(&xt[af].mutex);
 546         return NULL;
 547 }
 548 EXPORT_SYMBOL_GPL(xt_find_table_lock);
 549
 550 void xt_table_unlock(struct xt_table *table)
 551 {
 552         mutex_unlock(&xt[table->af].mutex);
 553 }
 554 EXPORT_SYMBOL_GPL(xt_table_unlock);
 555
 556 #ifdef CONFIG_COMPAT
 557 void xt_compat_lock(int af)
 558 {
 559         mutex_lock(&xt[af].compat_mutex);
 560 }
 561 EXPORT_SYMBOL_GPL(xt_compat_lock);
 562
 563 void xt_compat_unlock(int af)
 564 {
 565         mutex_unlock(&xt[af].compat_mutex);
 566 }
 567 EXPORT_SYMBOL_GPL(xt_compat_unlock);
 568 #endif
 569
 570 struct xt_table_info *
 571 xt_replace_table(struct xt_table *table,
 572               unsigned int num_counters,
 573               struct xt_table_info *newinfo,
 574               int *error)
 575 {
 576         struct xt_table_info *oldinfo, *private;
 577
 578         /* Do the substitution. */
 579         write_lock_bh(&table->lock);
 580         private = table->private;
 581         /* Check inside lock: is the old number correct? */
 582         if (num_counters != private->number) {
 583                 duprintf("num_counters != table->private->number (%u/%u)\n",
 584                          num_counters, private->number);
 585                 write_unlock_bh(&table->lock);
 586                 *error = -EAGAIN;
 587                 return NULL;
 588         }
 589         oldinfo = private;
 590         table->private = newinfo;
 591         newinfo->initial_entries = oldinfo->initial_entries;
 592         write_unlock_bh(&table->lock);
 593
 594         return oldinfo;
 595 }
 596 EXPORT_SYMBOL_GPL(xt_replace_table);
 597
 598 int xt_register_table(struct xt_table *table,
 599                       struct xt_table_info *bootstrap,
 600                       struct xt_table_info *newinfo)
 601 {
 602         int ret;
 603         struct xt_table_info *private;
 604         struct xt_table *t;
 605
 606         ret = mutex_lock_interruptible(&xt[table->af].mutex);
 607         if (ret != 0)
 608                 return ret;
 609
 610         /* Don't autoload: we'd eat our tail... */
 611         list_for_each_entry(t, &xt[table->af].tables, list) {
 612                 if (strcmp(t->name, table->name) == 0) {
 613                         ret = -EEXIST;
 614                         goto unlock;
 615                 }
 616         }
 617
 618         /* Simplifies replace_table code. */
 619         table->private = bootstrap;
 620         rwlock_init(&table->lock);
 621         if (!xt_replace_table(table, 0, newinfo, &ret))
 622                 goto unlock;
 623
 624         private = table->private;
 625         duprintf("table->private->number = %u\n", private->number);
 626
 627         /* save number of initial entries */
 628         private->initial_entries = private->number;
 629
 630         list_add(&table->list, &xt[table->af].tables);
 631
 632         ret = 0;
 633  unlock:
 634         mutex_unlock(&xt[table->af].mutex);
 635         return ret;
 636 }
 637 EXPORT_SYMBOL_GPL(xt_register_table);
 638
 639 void *xt_unregister_table(struct xt_table *table)
 640 {
 641         struct xt_table_info *private;
 642
 643         mutex_lock(&xt[table->af].mutex);
 644         private = table->private;
 645         list_del(&table->list);
 646         mutex_unlock(&xt[table->af].mutex);
 647
 648         return private;
 649 }
 650 EXPORT_SYMBOL_GPL(xt_unregister_table);
 651
 652 #ifdef CONFIG_PROC_FS
 653 static char *xt_proto_prefix[NPROTO] = {
 654         [AF_INET]       = "ip",
 655         [AF_INET6]      = "ip6",
 656         [NF_ARP]        = "arp",
 657 };
 658
 659 static struct list_head *xt_get_idx(struct list_head *list, struct seq_file *seq, loff_t pos)
 660 {
 661         struct list_head *head = list->next;
 662
 663         if (!head || list_empty(list))
 664                 return NULL;
 665
 666         while (pos && (head = head->next)) {
 667                 if (head == list)
 668                         return NULL;
 669                 pos--;
 670         }
 671         return pos ? NULL : head;
 672 }
 673
 674 static struct list_head *type2list(u_int16_t af, u_int16_t type)
 675 {
 676         struct list_head *list;
 677
 678         switch (type) {
 679         case TARGET:
 680                 list = &xt[af].target;
 681                 break;
 682         case MATCH:
 683                 list = &xt[af].match;
 684                 break;
 685         case TABLE:
 686                 list = &xt[af].tables;
 687                 break;
 688         default:
 689                 list = NULL;
 690                 break;
 691         }
 692
 693         return list;
 694 }
 695
 696 static void *xt_tgt_seq_start(struct seq_file *seq, loff_t *pos)
 697 {
 698         struct proc_dir_entry *pde = (struct proc_dir_entry *) seq->private;
 699         u_int16_t af = (unsigned long)pde->data & 0xffff;
 700         u_int16_t type = (unsigned long)pde->data >> 16;
 701         struct list_head *list;
 702
 703         if (af >= NPROTO)
 704                 return NULL;
 705
 706         list = type2list(af, type);
 707         if (!list)
 708                 return NULL;
 709
 710         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 711                 return NULL;
 712
 713         return xt_get_idx(list, seq, *pos);
 714 }
 715
 716 static void *xt_tgt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 717 {
 718         struct proc_dir_entry *pde = seq->private;
 719         u_int16_t af = (unsigned long)pde->data & 0xffff;
 720         u_int16_t type = (unsigned long)pde->data >> 16;
 721         struct list_head *list;
 722
 723         if (af >= NPROTO)
 724                 return NULL;
 725
 726         list = type2list(af, type);
 727         if (!list)
 728                 return NULL;
 729
 730         (*pos)++;
 731         return xt_get_idx(list, seq, *pos);
 732 }
 733
 734 static void xt_tgt_seq_stop(struct seq_file *seq, void *v)
 735 {
 736         struct proc_dir_entry *pde = seq->private;
 737         u_int16_t af = (unsigned long)pde->data & 0xffff;
 738
 739         mutex_unlock(&xt[af].mutex);
 740 }
 741
 742 static int xt_name_seq_show(struct seq_file *seq, void *v)
 743 {
 744         char *name = (char *)v + sizeof(struct list_head);
 745
 746         if (strlen(name))
 747                 return seq_printf(seq, "%s\n", name);
 748         else
 749                 return 0;
 750 }
 751
 752 static struct seq_operations xt_tgt_seq_ops = {
 753         .start  = xt_tgt_seq_start,
 754         .next   = xt_tgt_seq_next,
 755         .stop   = xt_tgt_seq_stop,
 756         .show   = xt_name_seq_show,
 757 };
 758
 759 static int xt_tgt_open(struct inode *inode, struct file *file)
 760 {
 761         int ret;
 762
 763         ret = seq_open(file, &xt_tgt_seq_ops);
 764         if (!ret) {
 765                 struct seq_file *seq = file->private_data;
 766                 struct proc_dir_entry *pde = PDE(inode);
 767
 768                 seq->private = pde;
 769         }
 770
 771         return ret;
 772 }
 773
 774 static struct file_operations xt_file_ops = {
 775         .owner   = THIS_MODULE,
 776         .open    = xt_tgt_open,
 777         .read    = seq_read,
 778         .llseek  = seq_lseek,
 779         .release = seq_release,
 780 };
 781
 782 #define FORMAT_TABLES   "_tables_names"
 783 #define FORMAT_MATCHES  "_tables_matches"
 784 #define FORMAT_TARGETS  "_tables_targets"
 785
 786 #endif /* CONFIG_PROC_FS */
 787
 788 int xt_proto_init(int af)
 789 {
 790 #ifdef CONFIG_PROC_FS
 791         char buf[XT_FUNCTION_MAXNAMELEN];
 792         struct proc_dir_entry *proc;
 793 #endif
 794
 795         if (af >= NPROTO)
 796                 return -EINVAL;
 797
 798
 799 #ifdef CONFIG_PROC_FS
 800         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 801         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 802         proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
 803         if (!proc)
 804                 goto out;
 805         proc->data = (void *) ((unsigned long) af | (TABLE << 16));
 806
 807
 808         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 809         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 810         proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
 811         if (!proc)
 812                 goto out_remove_tables;
 813         proc->data = (void *) ((unsigned long) af | (MATCH << 16));
 814
 815         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 816         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 817         proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
 818         if (!proc)
 819                 goto out_remove_matches;
 820         proc->data = (void *) ((unsigned long) af | (TARGET << 16));
 821 #endif
 822
 823         return 0;
 824
 825 #ifdef CONFIG_PROC_FS
 826 out_remove_matches:
 827         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 828         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 829         proc_net_remove(buf);
 830
 831 out_remove_tables:
 832         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 833         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 834         proc_net_remove(buf);
 835 out:
 836         return -1;
 837 #endif
 838 }
 839 EXPORT_SYMBOL_GPL(xt_proto_init);
 840
 841 void xt_proto_fini(int af)
 842 {
 843 #ifdef CONFIG_PROC_FS
 844         char buf[XT_FUNCTION_MAXNAMELEN];
 845
 846         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 847         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 848         proc_net_remove(buf);
 849
 850         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 851         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 852         proc_net_remove(buf);
 853
 854         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 855         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 856         proc_net_remove(buf);
 857 #endif /*CONFIG_PROC_FS*/
 858 }
 859 EXPORT_SYMBOL_GPL(xt_proto_fini);
 860
 861
 862 static int __init xt_init(void)
 863 {
 864         int i;
 865
 866         xt = kmalloc(sizeof(struct xt_af) * NPROTO, GFP_KERNEL);
 867         if (!xt)
 868                 return -ENOMEM;
 869
 870         for (i = 0; i < NPROTO; i++) {
 871                 mutex_init(&xt[i].mutex);
 872 #ifdef CONFIG_COMPAT
 873                 mutex_init(&xt[i].compat_mutex);
 874 #endif
 875                 INIT_LIST_HEAD(&xt[i].target);
 876                 INIT_LIST_HEAD(&xt[i].match);
 877                 INIT_LIST_HEAD(&xt[i].tables);
 878         }
 879         return 0;
 880 }
 881
 882 static void __exit xt_fini(void)
 883 {
 884         kfree(xt);
 885 }
 886
 887 module_init(xt_init);
 888 module_exit(xt_fini);
 889