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