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
  26 #include <linux/netfilter/x_tables.h>
  27 #include <linux/netfilter_arp.h>
  28
  29
  30 MODULE_LICENSE("GPL");
  31 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
  32 MODULE_DESCRIPTION("[ip,ip6,arp]_tables backend module");
  33
  34 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
  35
  36 struct xt_af {
  37         struct mutex mutex;
  38         struct list_head match;
  39         struct list_head target;
  40         struct list_head tables;
  41         struct mutex compat_mutex;
  42 };
  43
  44 static struct xt_af *xt;
  45
  46 #ifdef DEBUG_IP_FIREWALL_USER
  47 #define duprintf(format, args...) printk(format , ## args)
  48 #else
  49 #define duprintf(format, args...)
  50 #endif
  51
  52 enum {
  53         TABLE,
  54         TARGET,
  55         MATCH,
  56 };
  57
  58 static const char *xt_prefix[NPROTO] = {
  59         [AF_INET]       = "ip",
  60         [AF_INET6]      = "ip6",
  61         [NF_ARP]        = "arp",
  62 };
  63
  64 /* Registration hooks for targets. */
  65 int
  66 xt_register_target(struct xt_target *target)
  67 {
  68         int ret, af = target->family;
  69
  70         ret = mutex_lock_interruptible(&xt[af].mutex);
  71         if (ret != 0)
  72                 return ret;
  73         list_add(&target->list, &xt[af].target);
  74         mutex_unlock(&xt[af].mutex);
  75         return ret;
  76 }
  77 EXPORT_SYMBOL(xt_register_target);
  78
  79 void
  80 xt_unregister_target(struct xt_target *target)
  81 {
  82         int af = target->family;
  83
  84         mutex_lock(&xt[af].mutex);
  85         list_del(&target->list);
  86         mutex_unlock(&xt[af].mutex);
  87 }
  88 EXPORT_SYMBOL(xt_unregister_target);
  89
  90 int
  91 xt_register_targets(struct xt_target *target, unsigned int n)
  92 {
  93         unsigned int i;
  94         int err = 0;
  95
  96         for (i = 0; i < n; i++) {
  97                 err = xt_register_target(&target[i]);
  98                 if (err)
  99                         goto err;
 100         }
 101         return err;
 102
 103 err:
 104         if (i > 0)
 105                 xt_unregister_targets(target, i);
 106         return err;
 107 }
 108 EXPORT_SYMBOL(xt_register_targets);
 109
 110 void
 111 xt_unregister_targets(struct xt_target *target, unsigned int n)
 112 {
 113         unsigned int i;
 114
 115         for (i = 0; i < n; i++)
 116                 xt_unregister_target(&target[i]);
 117 }
 118 EXPORT_SYMBOL(xt_unregister_targets);
 119
 120 int
 121 xt_register_match(struct xt_match *match)
 122 {
 123         int ret, af = match->family;
 124
 125         ret = mutex_lock_interruptible(&xt[af].mutex);
 126         if (ret != 0)
 127                 return ret;
 128
 129         list_add(&match->list, &xt[af].match);
 130         mutex_unlock(&xt[af].mutex);
 131
 132         return ret;
 133 }
 134 EXPORT_SYMBOL(xt_register_match);
 135
 136 void
 137 xt_unregister_match(struct xt_match *match)
 138 {
 139         int af =  match->family;
 140
 141         mutex_lock(&xt[af].mutex);
 142         list_del(&match->list);
 143         mutex_unlock(&xt[af].mutex);
 144 }
 145 EXPORT_SYMBOL(xt_unregister_match);
 146
 147 int
 148 xt_register_matches(struct xt_match *match, unsigned int n)
 149 {
 150         unsigned int i;
 151         int err = 0;
 152
 153         for (i = 0; i < n; i++) {
 154                 err = xt_register_match(&match[i]);
 155                 if (err)
 156                         goto err;
 157         }
 158         return err;
 159
 160 err:
 161         if (i > 0)
 162                 xt_unregister_matches(match, i);
 163         return err;
 164 }
 165 EXPORT_SYMBOL(xt_register_matches);
 166
 167 void
 168 xt_unregister_matches(struct xt_match *match, unsigned int n)
 169 {
 170         unsigned int i;
 171
 172         for (i = 0; i < n; i++)
 173                 xt_unregister_match(&match[i]);
 174 }
 175 EXPORT_SYMBOL(xt_unregister_matches);
 176
 177
 178 /*
 179  * These are weird, but module loading must not be done with mutex
 180  * held (since they will register), and we have to have a single
 181  * function to use try_then_request_module().
 182  */
 183
 184 /* Find match, grabs ref.  Returns ERR_PTR() on error. */
 185 struct xt_match *xt_find_match(int af, const char *name, u8 revision)
 186 {
 187         struct xt_match *m;
 188         int err = 0;
 189
 190         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 191                 return ERR_PTR(-EINTR);
 192
 193         list_for_each_entry(m, &xt[af].match, list) {
 194                 if (strcmp(m->name, name) == 0) {
 195                         if (m->revision == revision) {
 196                                 if (try_module_get(m->me)) {
 197                                         mutex_unlock(&xt[af].mutex);
 198                                         return m;
 199                                 }
 200                         } else
 201                                 err = -EPROTOTYPE; /* Found something. */
 202                 }
 203         }
 204         mutex_unlock(&xt[af].mutex);
 205         return ERR_PTR(err);
 206 }
 207 EXPORT_SYMBOL(xt_find_match);
 208
 209 /* Find target, grabs ref.  Returns ERR_PTR() on error. */
 210 struct xt_target *xt_find_target(int af, const char *name, u8 revision)
 211 {
 212         struct xt_target *t;
 213         int err = 0;
 214
 215         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 216                 return ERR_PTR(-EINTR);
 217
 218         list_for_each_entry(t, &xt[af].target, list) {
 219                 if (strcmp(t->name, name) == 0) {
 220                         if (t->revision == revision) {
 221                                 if (try_module_get(t->me)) {
 222                                         mutex_unlock(&xt[af].mutex);
 223                                         return t;
 224                                 }
 225                         } else
 226                                 err = -EPROTOTYPE; /* Found something. */
 227                 }
 228         }
 229         mutex_unlock(&xt[af].mutex);
 230         return ERR_PTR(err);
 231 }
 232 EXPORT_SYMBOL(xt_find_target);
 233
 234 struct xt_target *xt_request_find_target(int af, const char *name, u8 revision)
 235 {
 236         struct xt_target *target;
 237
 238         target = try_then_request_module(xt_find_target(af, name, revision),
 239                                          "%st_%s", xt_prefix[af], name);
 240         if (IS_ERR(target) || !target)
 241                 return NULL;
 242         return target;
 243 }
 244 EXPORT_SYMBOL_GPL(xt_request_find_target);
 245
 246 static int match_revfn(int af, const char *name, u8 revision, int *bestp)
 247 {
 248         struct xt_match *m;
 249         int have_rev = 0;
 250
 251         list_for_each_entry(m, &xt[af].match, list) {
 252                 if (strcmp(m->name, name) == 0) {
 253                         if (m->revision > *bestp)
 254                                 *bestp = m->revision;
 255                         if (m->revision == revision)
 256                                 have_rev = 1;
 257                 }
 258         }
 259         return have_rev;
 260 }
 261
 262 static int target_revfn(int af, const char *name, u8 revision, int *bestp)
 263 {
 264         struct xt_target *t;
 265         int have_rev = 0;
 266
 267         list_for_each_entry(t, &xt[af].target, list) {
 268                 if (strcmp(t->name, name) == 0) {
 269                         if (t->revision > *bestp)
 270                                 *bestp = t->revision;
 271                         if (t->revision == revision)
 272                                 have_rev = 1;
 273                 }
 274         }
 275         return have_rev;
 276 }
 277
 278 /* Returns true or false (if no such extension at all) */
 279 int xt_find_revision(int af, const char *name, u8 revision, int target,
 280                      int *err)
 281 {
 282         int have_rev, best = -1;
 283
 284         if (mutex_lock_interruptible(&xt[af].mutex) != 0) {
 285                 *err = -EINTR;
 286                 return 1;
 287         }
 288         if (target == 1)
 289                 have_rev = target_revfn(af, name, revision, &best);
 290         else
 291                 have_rev = match_revfn(af, name, revision, &best);
 292         mutex_unlock(&xt[af].mutex);
 293
 294         /* Nothing at all?  Return 0 to try loading module. */
 295         if (best == -1) {
 296                 *err = -ENOENT;
 297                 return 0;
 298         }
 299
 300         *err = best;
 301         if (!have_rev)
 302                 *err = -EPROTONOSUPPORT;
 303         return 1;
 304 }
 305 EXPORT_SYMBOL_GPL(xt_find_revision);
 306
 307 int xt_check_match(const struct xt_match *match, unsigned short family,
 308                    unsigned int size, const char *table, unsigned int hook_mask,
 309                    unsigned short proto, int inv_proto)
 310 {
 311         if (XT_ALIGN(match->matchsize) != size) {
 312                 printk("%s_tables: %s match: invalid size %Zu != %u\n",
 313                        xt_prefix[family], match->name,
 314                        XT_ALIGN(match->matchsize), size);
 315                 return -EINVAL;
 316         }
 317         if (match->table && strcmp(match->table, table)) {
 318                 printk("%s_tables: %s match: only valid in %s table, not %s\n",
 319                        xt_prefix[family], match->name, match->table, table);
 320                 return -EINVAL;
 321         }
 322         if (match->hooks && (hook_mask & ~match->hooks) != 0) {
 323                 printk("%s_tables: %s match: bad hook_mask %u\n",
 324                        xt_prefix[family], match->name, hook_mask);
 325                 return -EINVAL;
 326         }
 327         if (match->proto && (match->proto != proto || inv_proto)) {
 328                 printk("%s_tables: %s match: only valid for protocol %u\n",
 329                        xt_prefix[family], match->name, match->proto);
 330                 return -EINVAL;
 331         }
 332         return 0;
 333 }
 334 EXPORT_SYMBOL_GPL(xt_check_match);
 335
 336 #ifdef CONFIG_COMPAT
 337 int xt_compat_match_offset(struct xt_match *match)
 338 {
 339         u_int16_t csize = match->compatsize ? : match->matchsize;
 340         return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
 341 }
 342 EXPORT_SYMBOL_GPL(xt_compat_match_offset);
 343
 344 void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
 345                                int *size)
 346 {
 347         struct xt_match *match = m->u.kernel.match;
 348         struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
 349         int pad, off = xt_compat_match_offset(match);
 350         u_int16_t msize = cm->u.user.match_size;
 351
 352         m = *dstptr;
 353         memcpy(m, cm, sizeof(*cm));
 354         if (match->compat_from_user)
 355                 match->compat_from_user(m->data, cm->data);
 356         else
 357                 memcpy(m->data, cm->data, msize - sizeof(*cm));
 358         pad = XT_ALIGN(match->matchsize) - match->matchsize;
 359         if (pad > 0)
 360                 memset(m->data + match->matchsize, 0, pad);
 361
 362         msize += off;
 363         m->u.user.match_size = msize;
 364
 365         *size += off;
 366         *dstptr += msize;
 367 }
 368 EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
 369
 370 int xt_compat_match_to_user(struct xt_entry_match *m, void __user **dstptr,
 371                             int *size)
 372 {
 373         struct xt_match *match = m->u.kernel.match;
 374         struct compat_xt_entry_match __user *cm = *dstptr;
 375         int off = xt_compat_match_offset(match);
 376         u_int16_t msize = m->u.user.match_size - off;
 377
 378         if (copy_to_user(cm, m, sizeof(*cm)) ||
 379             put_user(msize, &cm->u.user.match_size))
 380                 return -EFAULT;
 381
 382         if (match->compat_to_user) {
 383                 if (match->compat_to_user((void __user *)cm->data, m->data))
 384                         return -EFAULT;
 385         } else {
 386                 if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
 387                         return -EFAULT;
 388         }
 389
 390         *size -= off;
 391         *dstptr += msize;
 392         return 0;
 393 }
 394 EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
 395 #endif /* CONFIG_COMPAT */
 396
 397 int xt_check_target(const struct xt_target *target, unsigned short family,
 398                     unsigned int size, const char *table, unsigned int hook_mask,
 399                     unsigned short proto, int inv_proto)
 400 {
 401         if (XT_ALIGN(target->targetsize) != size) {
 402                 printk("%s_tables: %s target: invalid size %Zu != %u\n",
 403                        xt_prefix[family], target->name,
 404                        XT_ALIGN(target->targetsize), size);
 405                 return -EINVAL;
 406         }
 407         if (target->table && strcmp(target->table, table)) {
 408                 printk("%s_tables: %s target: only valid in %s table, not %s\n",
 409                        xt_prefix[family], target->name, target->table, table);
 410                 return -EINVAL;
 411         }
 412         if (target->hooks && (hook_mask & ~target->hooks) != 0) {
 413                 printk("%s_tables: %s target: bad hook_mask %u\n",
 414                        xt_prefix[family], target->name, hook_mask);
 415                 return -EINVAL;
 416         }
 417         if (target->proto && (target->proto != proto || inv_proto)) {
 418                 printk("%s_tables: %s target: only valid for protocol %u\n",
 419                        xt_prefix[family], target->name, target->proto);
 420                 return -EINVAL;
 421         }
 422         return 0;
 423 }
 424 EXPORT_SYMBOL_GPL(xt_check_target);
 425
 426 #ifdef CONFIG_COMPAT
 427 int xt_compat_target_offset(struct xt_target *target)
 428 {
 429         u_int16_t csize = target->compatsize ? : target->targetsize;
 430         return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
 431 }
 432 EXPORT_SYMBOL_GPL(xt_compat_target_offset);
 433
 434 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
 435                                 int *size)
 436 {
 437         struct xt_target *target = t->u.kernel.target;
 438         struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
 439         int pad, off = xt_compat_target_offset(target);
 440         u_int16_t tsize = ct->u.user.target_size;
 441
 442         t = *dstptr;
 443         memcpy(t, ct, sizeof(*ct));
 444         if (target->compat_from_user)
 445                 target->compat_from_user(t->data, ct->data);
 446         else
 447                 memcpy(t->data, ct->data, tsize - sizeof(*ct));
 448         pad = XT_ALIGN(target->targetsize) - target->targetsize;
 449         if (pad > 0)
 450                 memset(t->data + target->targetsize, 0, pad);
 451
 452         tsize += off;
 453         t->u.user.target_size = tsize;
 454
 455         *size += off;
 456         *dstptr += tsize;
 457 }
 458 EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
 459
 460 int xt_compat_target_to_user(struct xt_entry_target *t, void __user **dstptr,
 461                              int *size)
 462 {
 463         struct xt_target *target = t->u.kernel.target;
 464         struct compat_xt_entry_target __user *ct = *dstptr;
 465         int off = xt_compat_target_offset(target);
 466         u_int16_t tsize = t->u.user.target_size - off;
 467
 468         if (copy_to_user(ct, t, sizeof(*ct)) ||
 469             put_user(tsize, &ct->u.user.target_size))
 470                 return -EFAULT;
 471
 472         if (target->compat_to_user) {
 473                 if (target->compat_to_user((void __user *)ct->data, t->data))
 474                         return -EFAULT;
 475         } else {
 476                 if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
 477                         return -EFAULT;
 478         }
 479
 480         *size -= off;
 481         *dstptr += tsize;
 482         return 0;
 483 }
 484 EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
 485 #endif
 486
 487 struct xt_table_info *xt_alloc_table_info(unsigned int size)
 488 {
 489         struct xt_table_info *newinfo;
 490         int cpu;
 491
 492         /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
 493         if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
 494                 return NULL;
 495
 496         newinfo = kzalloc(sizeof(struct xt_table_info), GFP_KERNEL);
 497         if (!newinfo)
 498                 return NULL;
 499
 500         newinfo->size = size;
 501
 502         for_each_possible_cpu(cpu) {
 503                 if (size <= PAGE_SIZE)
 504                         newinfo->entries[cpu] = kmalloc_node(size,
 505                                                         GFP_KERNEL,
 506                                                         cpu_to_node(cpu));
 507                 else
 508                         newinfo->entries[cpu] = vmalloc_node(size,
 509                                                         cpu_to_node(cpu));
 510
 511                 if (newinfo->entries[cpu] == NULL) {
 512                         xt_free_table_info(newinfo);
 513                         return NULL;
 514                 }
 515         }
 516
 517         return newinfo;
 518 }
 519 EXPORT_SYMBOL(xt_alloc_table_info);
 520
 521 void xt_free_table_info(struct xt_table_info *info)
 522 {
 523         int cpu;
 524
 525         for_each_possible_cpu(cpu) {
 526                 if (info->size <= PAGE_SIZE)
 527                         kfree(info->entries[cpu]);
 528                 else
 529                         vfree(info->entries[cpu]);
 530         }
 531         kfree(info);
 532 }
 533 EXPORT_SYMBOL(xt_free_table_info);
 534
 535 /* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
 536 struct xt_table *xt_find_table_lock(int af, const char *name)
 537 {
 538         struct xt_table *t;
 539
 540         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 541                 return ERR_PTR(-EINTR);
 542
 543         list_for_each_entry(t, &xt[af].tables, list)
 544                 if (strcmp(t->name, name) == 0 && try_module_get(t->me))
 545                         return t;
 546         mutex_unlock(&xt[af].mutex);
 547         return NULL;
 548 }
 549 EXPORT_SYMBOL_GPL(xt_find_table_lock);
 550
 551 void xt_table_unlock(struct xt_table *table)
 552 {
 553         mutex_unlock(&xt[table->af].mutex);
 554 }
 555 EXPORT_SYMBOL_GPL(xt_table_unlock);
 556
 557 #ifdef CONFIG_COMPAT
 558 void xt_compat_lock(int af)
 559 {
 560         mutex_lock(&xt[af].compat_mutex);
 561 }
 562 EXPORT_SYMBOL_GPL(xt_compat_lock);
 563
 564 void xt_compat_unlock(int af)
 565 {
 566         mutex_unlock(&xt[af].compat_mutex);
 567 }
 568 EXPORT_SYMBOL_GPL(xt_compat_unlock);
 569 #endif
 570
 571 struct xt_table_info *
 572 xt_replace_table(struct xt_table *table,
 573               unsigned int num_counters,
 574               struct xt_table_info *newinfo,
 575               int *error)
 576 {
 577         struct xt_table_info *oldinfo, *private;
 578
 579         /* Do the substitution. */
 580         write_lock_bh(&table->lock);
 581         private = table->private;
 582         /* Check inside lock: is the old number correct? */
 583         if (num_counters != private->number) {
 584                 duprintf("num_counters != table->private->number (%u/%u)\n",
 585                          num_counters, private->number);
 586                 write_unlock_bh(&table->lock);
 587                 *error = -EAGAIN;
 588                 return NULL;
 589         }
 590         oldinfo = private;
 591         table->private = newinfo;
 592         newinfo->initial_entries = oldinfo->initial_entries;
 593         write_unlock_bh(&table->lock);
 594
 595         return oldinfo;
 596 }
 597 EXPORT_SYMBOL_GPL(xt_replace_table);
 598
 599 int xt_register_table(struct xt_table *table,
 600                       struct xt_table_info *bootstrap,
 601                       struct xt_table_info *newinfo)
 602 {
 603         int ret;
 604         struct xt_table_info *private;
 605         struct xt_table *t;
 606
 607         ret = mutex_lock_interruptible(&xt[table->af].mutex);
 608         if (ret != 0)
 609                 return ret;
 610
 611         /* Don't autoload: we'd eat our tail... */
 612         list_for_each_entry(t, &xt[table->af].tables, list) {
 613                 if (strcmp(t->name, table->name) == 0) {
 614                         ret = -EEXIST;
 615                         goto unlock;
 616                 }
 617         }
 618
 619         /* Simplifies replace_table code. */
 620         table->private = bootstrap;
 621         rwlock_init(&table->lock);
 622         if (!xt_replace_table(table, 0, newinfo, &ret))
 623                 goto unlock;
 624
 625         private = table->private;
 626         duprintf("table->private->number = %u\n", private->number);
 627
 628         /* save number of initial entries */
 629         private->initial_entries = private->number;
 630
 631         list_add(&table->list, &xt[table->af].tables);
 632
 633         ret = 0;
 634  unlock:
 635         mutex_unlock(&xt[table->af].mutex);
 636         return ret;
 637 }
 638 EXPORT_SYMBOL_GPL(xt_register_table);
 639
 640 void *xt_unregister_table(struct xt_table *table)
 641 {
 642         struct xt_table_info *private;
 643
 644         mutex_lock(&xt[table->af].mutex);
 645         private = table->private;
 646         list_del(&table->list);
 647         mutex_unlock(&xt[table->af].mutex);
 648
 649         return private;
 650 }
 651 EXPORT_SYMBOL_GPL(xt_unregister_table);
 652
 653 #ifdef CONFIG_PROC_FS
 654 static char *xt_proto_prefix[NPROTO] = {
 655         [AF_INET]       = "ip",
 656         [AF_INET6]      = "ip6",
 657         [NF_ARP]        = "arp",
 658 };
 659
 660 static struct list_head *xt_get_idx(struct list_head *list, struct seq_file *seq, loff_t pos)
 661 {
 662         struct list_head *head = list->next;
 663
 664         if (!head || list_empty(list))
 665                 return NULL;
 666
 667         while (pos && (head = head->next)) {
 668                 if (head == list)
 669                         return NULL;
 670                 pos--;
 671         }
 672         return pos ? NULL : head;
 673 }
 674
 675 static struct list_head *type2list(u_int16_t af, u_int16_t type)
 676 {
 677         struct list_head *list;
 678
 679         switch (type) {
 680         case TARGET:
 681                 list = &xt[af].target;
 682                 break;
 683         case MATCH:
 684                 list = &xt[af].match;
 685                 break;
 686         case TABLE:
 687                 list = &xt[af].tables;
 688                 break;
 689         default:
 690                 list = NULL;
 691                 break;
 692         }
 693
 694         return list;
 695 }
 696
 697 static void *xt_tgt_seq_start(struct seq_file *seq, loff_t *pos)
 698 {
 699         struct proc_dir_entry *pde = (struct proc_dir_entry *) seq->private;
 700         u_int16_t af = (unsigned long)pde->data & 0xffff;
 701         u_int16_t type = (unsigned long)pde->data >> 16;
 702         struct list_head *list;
 703
 704         if (af >= NPROTO)
 705                 return NULL;
 706
 707         list = type2list(af, type);
 708         if (!list)
 709                 return NULL;
 710
 711         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 712                 return NULL;
 713
 714         return xt_get_idx(list, seq, *pos);
 715 }
 716
 717 static void *xt_tgt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 718 {
 719         struct proc_dir_entry *pde = seq->private;
 720         u_int16_t af = (unsigned long)pde->data & 0xffff;
 721         u_int16_t type = (unsigned long)pde->data >> 16;
 722         struct list_head *list;
 723
 724         if (af >= NPROTO)
 725                 return NULL;
 726
 727         list = type2list(af, type);
 728         if (!list)
 729                 return NULL;
 730
 731         (*pos)++;
 732         return xt_get_idx(list, seq, *pos);
 733 }
 734
 735 static void xt_tgt_seq_stop(struct seq_file *seq, void *v)
 736 {
 737         struct proc_dir_entry *pde = seq->private;
 738         u_int16_t af = (unsigned long)pde->data & 0xffff;
 739
 740         mutex_unlock(&xt[af].mutex);
 741 }
 742
 743 static int xt_name_seq_show(struct seq_file *seq, void *v)
 744 {
 745         char *name = (char *)v + sizeof(struct list_head);
 746
 747         if (strlen(name))
 748                 return seq_printf(seq, "%s\n", name);
 749         else
 750                 return 0;
 751 }
 752
 753 static struct seq_operations xt_tgt_seq_ops = {
 754         .start  = xt_tgt_seq_start,
 755         .next   = xt_tgt_seq_next,
 756         .stop   = xt_tgt_seq_stop,
 757         .show   = xt_name_seq_show,
 758 };
 759
 760 static int xt_tgt_open(struct inode *inode, struct file *file)
 761 {
 762         int ret;
 763
 764         ret = seq_open(file, &xt_tgt_seq_ops);
 765         if (!ret) {
 766                 struct seq_file *seq = file->private_data;
 767                 struct proc_dir_entry *pde = PDE(inode);
 768
 769                 seq->private = pde;
 770         }
 771
 772         return ret;
 773 }
 774
 775 static const struct file_operations xt_file_ops = {
 776         .owner   = THIS_MODULE,
 777         .open    = xt_tgt_open,
 778         .read    = seq_read,
 779         .llseek  = seq_lseek,
 780         .release = seq_release,
 781 };
 782
 783 #define FORMAT_TABLES   "_tables_names"
 784 #define FORMAT_MATCHES  "_tables_matches"
 785 #define FORMAT_TARGETS  "_tables_targets"
 786
 787 #endif /* CONFIG_PROC_FS */
 788
 789 int xt_proto_init(int af)
 790 {
 791 #ifdef CONFIG_PROC_FS
 792         char buf[XT_FUNCTION_MAXNAMELEN];
 793         struct proc_dir_entry *proc;
 794 #endif
 795
 796         if (af >= NPROTO)
 797                 return -EINVAL;
 798
 799
 800 #ifdef CONFIG_PROC_FS
 801         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 802         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 803         proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
 804         if (!proc)
 805                 goto out;
 806         proc->data = (void *) ((unsigned long) af | (TABLE << 16));
 807
 808
 809         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 810         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 811         proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
 812         if (!proc)
 813                 goto out_remove_tables;
 814         proc->data = (void *) ((unsigned long) af | (MATCH << 16));
 815
 816         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 817         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 818         proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
 819         if (!proc)
 820                 goto out_remove_matches;
 821         proc->data = (void *) ((unsigned long) af | (TARGET << 16));
 822 #endif
 823
 824         return 0;
 825
 826 #ifdef CONFIG_PROC_FS
 827 out_remove_matches:
 828         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 829         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 830         proc_net_remove(buf);
 831
 832 out_remove_tables:
 833         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 834         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 835         proc_net_remove(buf);
 836 out:
 837         return -1;
 838 #endif
 839 }
 840 EXPORT_SYMBOL_GPL(xt_proto_init);
 841
 842 void xt_proto_fini(int af)
 843 {
 844 #ifdef CONFIG_PROC_FS
 845         char buf[XT_FUNCTION_MAXNAMELEN];
 846
 847         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 848         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 849         proc_net_remove(buf);
 850
 851         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 852         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 853         proc_net_remove(buf);
 854
 855         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 856         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 857         proc_net_remove(buf);
 858 #endif /*CONFIG_PROC_FS*/
 859 }
 860 EXPORT_SYMBOL_GPL(xt_proto_fini);
 861
 862
 863 static int __init xt_init(void)
 864 {
 865         int i;
 866
 867         xt = kmalloc(sizeof(struct xt_af) * NPROTO, GFP_KERNEL);
 868         if (!xt)
 869                 return -ENOMEM;
 870
 871         for (i = 0; i < NPROTO; i++) {
 872                 mutex_init(&xt[i].mutex);
 873 #ifdef CONFIG_COMPAT
 874                 mutex_init(&xt[i].compat_mutex);
 875 #endif
 876                 INIT_LIST_HEAD(&xt[i].target);
 877                 INIT_LIST_HEAD(&xt[i].match);
 878                 INIT_LIST_HEAD(&xt[i].tables);
 879         }
 880         return 0;
 881 }
 882
 883 static void __exit xt_fini(void)
 884 {
 885         kfree(xt);
 886 }
 887
 888 module_init(xt_init);
 889 module_exit(xt_fini);
 890