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_DELETE(&xt[af].target, target);
  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_DELETE(&xt[af].match, match);
 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(void *match, void **dstptr, int *size, int convert)
 337 {
 338         struct xt_match *m;
 339         struct compat_xt_entry_match *pcompat_m;
 340         struct xt_entry_match *pm;
 341         u_int16_t msize;
 342         int off, ret;
 343
 344         ret = 0;
 345         m = ((struct xt_entry_match *)match)->u.kernel.match;
 346         off = XT_ALIGN(m->matchsize) - COMPAT_XT_ALIGN(m->matchsize);
 347         switch (convert) {
 348                 case COMPAT_TO_USER:
 349                         pm = (struct xt_entry_match *)match;
 350                         msize = pm->u.user.match_size;
 351                         if (copy_to_user(*dstptr, pm, msize)) {
 352                                 ret = -EFAULT;
 353                                 break;
 354                         }
 355                         msize -= off;
 356                         if (put_user(msize, (u_int16_t *)*dstptr))
 357                                 ret = -EFAULT;
 358                         *size -= off;
 359                         *dstptr += msize;
 360                         break;
 361                 case COMPAT_FROM_USER:
 362                         pcompat_m = (struct compat_xt_entry_match *)match;
 363                         pm = (struct xt_entry_match *)*dstptr;
 364                         msize = pcompat_m->u.user.match_size;
 365                         memcpy(pm, pcompat_m, msize);
 366                         msize += off;
 367                         pm->u.user.match_size = msize;
 368                         *size += off;
 369                         *dstptr += msize;
 370                         break;
 371                 case COMPAT_CALC_SIZE:
 372                         *size += off;
 373                         break;
 374                 default:
 375                         ret = -ENOPROTOOPT;
 376                         break;
 377         }
 378         return ret;
 379 }
 380 EXPORT_SYMBOL_GPL(xt_compat_match);
 381 #endif
 382
 383 int xt_check_target(const struct xt_target *target, unsigned short family,
 384                     unsigned int size, const char *table, unsigned int hook_mask,
 385                     unsigned short proto, int inv_proto)
 386 {
 387         if (XT_ALIGN(target->targetsize) != size) {
 388                 printk("%s_tables: %s target: invalid size %Zu != %u\n",
 389                        xt_prefix[family], target->name,
 390                        XT_ALIGN(target->targetsize), size);
 391                 return -EINVAL;
 392         }
 393         if (target->table && strcmp(target->table, table)) {
 394                 printk("%s_tables: %s target: only valid in %s table, not %s\n",
 395                        xt_prefix[family], target->name, target->table, table);
 396                 return -EINVAL;
 397         }
 398         if (target->hooks && (hook_mask & ~target->hooks) != 0) {
 399                 printk("%s_tables: %s target: bad hook_mask %u\n",
 400                        xt_prefix[family], target->name, hook_mask);
 401                 return -EINVAL;
 402         }
 403         if (target->proto && (target->proto != proto || inv_proto)) {
 404                 printk("%s_tables: %s target: only valid for protocol %u\n",
 405                        xt_prefix[family], target->name, target->proto);
 406                 return -EINVAL;
 407         }
 408         return 0;
 409 }
 410 EXPORT_SYMBOL_GPL(xt_check_target);
 411
 412 #ifdef CONFIG_COMPAT
 413 int xt_compat_target(void *target, void **dstptr, int *size, int convert)
 414 {
 415         struct xt_target *t;
 416         struct compat_xt_entry_target *pcompat;
 417         struct xt_entry_target *pt;
 418         u_int16_t tsize;
 419         int off, ret;
 420
 421         ret = 0;
 422         t = ((struct xt_entry_target *)target)->u.kernel.target;
 423         off = XT_ALIGN(t->targetsize) - COMPAT_XT_ALIGN(t->targetsize);
 424         switch (convert) {
 425                 case COMPAT_TO_USER:
 426                         pt = (struct xt_entry_target *)target;
 427                         tsize = pt->u.user.target_size;
 428                         if (copy_to_user(*dstptr, pt, tsize)) {
 429                                 ret = -EFAULT;
 430                                 break;
 431                         }
 432                         tsize -= off;
 433                         if (put_user(tsize, (u_int16_t *)*dstptr))
 434                                 ret = -EFAULT;
 435                         *size -= off;
 436                         *dstptr += tsize;
 437                         break;
 438                 case COMPAT_FROM_USER:
 439                         pcompat = (struct compat_xt_entry_target *)target;
 440                         pt = (struct xt_entry_target *)*dstptr;
 441                         tsize = pcompat->u.user.target_size;
 442                         memcpy(pt, pcompat, tsize);
 443                         tsize += off;
 444                         pt->u.user.target_size = tsize;
 445                         *size += off;
 446                         *dstptr += tsize;
 447                         break;
 448                 case COMPAT_CALC_SIZE:
 449                         *size += off;
 450                         break;
 451                 default:
 452                         ret = -ENOPROTOOPT;
 453                         break;
 454         }
 455         return ret;
 456 }
 457 EXPORT_SYMBOL_GPL(xt_compat_target);
 458 #endif
 459
 460 struct xt_table_info *xt_alloc_table_info(unsigned int size)
 461 {
 462         struct xt_table_info *newinfo;
 463         int cpu;
 464
 465         /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
 466         if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
 467                 return NULL;
 468
 469         newinfo = kzalloc(sizeof(struct xt_table_info), GFP_KERNEL);
 470         if (!newinfo)
 471                 return NULL;
 472
 473         newinfo->size = size;
 474
 475         for_each_possible_cpu(cpu) {
 476                 if (size <= PAGE_SIZE)
 477                         newinfo->entries[cpu] = kmalloc_node(size,
 478                                                         GFP_KERNEL,
 479                                                         cpu_to_node(cpu));
 480                 else
 481                         newinfo->entries[cpu] = vmalloc_node(size,
 482                                                         cpu_to_node(cpu));
 483
 484                 if (newinfo->entries[cpu] == NULL) {
 485                         xt_free_table_info(newinfo);
 486                         return NULL;
 487                 }
 488         }
 489
 490         return newinfo;
 491 }
 492 EXPORT_SYMBOL(xt_alloc_table_info);
 493
 494 void xt_free_table_info(struct xt_table_info *info)
 495 {
 496         int cpu;
 497
 498         for_each_possible_cpu(cpu) {
 499                 if (info->size <= PAGE_SIZE)
 500                         kfree(info->entries[cpu]);
 501                 else
 502                         vfree(info->entries[cpu]);
 503         }
 504         kfree(info);
 505 }
 506 EXPORT_SYMBOL(xt_free_table_info);
 507
 508 /* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
 509 struct xt_table *xt_find_table_lock(int af, const char *name)
 510 {
 511         struct xt_table *t;
 512
 513         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 514                 return ERR_PTR(-EINTR);
 515
 516         list_for_each_entry(t, &xt[af].tables, list)
 517                 if (strcmp(t->name, name) == 0 && try_module_get(t->me))
 518                         return t;
 519         mutex_unlock(&xt[af].mutex);
 520         return NULL;
 521 }
 522 EXPORT_SYMBOL_GPL(xt_find_table_lock);
 523
 524 void xt_table_unlock(struct xt_table *table)
 525 {
 526         mutex_unlock(&xt[table->af].mutex);
 527 }
 528 EXPORT_SYMBOL_GPL(xt_table_unlock);
 529
 530 #ifdef CONFIG_COMPAT
 531 void xt_compat_lock(int af)
 532 {
 533         mutex_lock(&xt[af].compat_mutex);
 534 }
 535 EXPORT_SYMBOL_GPL(xt_compat_lock);
 536
 537 void xt_compat_unlock(int af)
 538 {
 539         mutex_unlock(&xt[af].compat_mutex);
 540 }
 541 EXPORT_SYMBOL_GPL(xt_compat_unlock);
 542 #endif
 543
 544 struct xt_table_info *
 545 xt_replace_table(struct xt_table *table,
 546               unsigned int num_counters,
 547               struct xt_table_info *newinfo,
 548               int *error)
 549 {
 550         struct xt_table_info *oldinfo, *private;
 551
 552         /* Do the substitution. */
 553         write_lock_bh(&table->lock);
 554         private = table->private;
 555         /* Check inside lock: is the old number correct? */
 556         if (num_counters != private->number) {
 557                 duprintf("num_counters != table->private->number (%u/%u)\n",
 558                          num_counters, private->number);
 559                 write_unlock_bh(&table->lock);
 560                 *error = -EAGAIN;
 561                 return NULL;
 562         }
 563         oldinfo = private;
 564         table->private = newinfo;
 565         newinfo->initial_entries = oldinfo->initial_entries;
 566         write_unlock_bh(&table->lock);
 567
 568         return oldinfo;
 569 }
 570 EXPORT_SYMBOL_GPL(xt_replace_table);
 571
 572 int xt_register_table(struct xt_table *table,
 573                       struct xt_table_info *bootstrap,
 574                       struct xt_table_info *newinfo)
 575 {
 576         int ret;
 577         struct xt_table_info *private;
 578
 579         ret = mutex_lock_interruptible(&xt[table->af].mutex);
 580         if (ret != 0)
 581                 return ret;
 582
 583         /* Don't autoload: we'd eat our tail... */
 584         if (list_named_find(&xt[table->af].tables, table->name)) {
 585                 ret = -EEXIST;
 586                 goto unlock;
 587         }
 588
 589         /* Simplifies replace_table code. */
 590         table->private = bootstrap;
 591         rwlock_init(&table->lock);
 592         if (!xt_replace_table(table, 0, newinfo, &ret))
 593                 goto unlock;
 594
 595         private = table->private;
 596         duprintf("table->private->number = %u\n", private->number);
 597
 598         /* save number of initial entries */
 599         private->initial_entries = private->number;
 600
 601         list_prepend(&xt[table->af].tables, table);
 602
 603         ret = 0;
 604  unlock:
 605         mutex_unlock(&xt[table->af].mutex);
 606         return ret;
 607 }
 608 EXPORT_SYMBOL_GPL(xt_register_table);
 609
 610 void *xt_unregister_table(struct xt_table *table)
 611 {
 612         struct xt_table_info *private;
 613
 614         mutex_lock(&xt[table->af].mutex);
 615         private = table->private;
 616         LIST_DELETE(&xt[table->af].tables, table);
 617         mutex_unlock(&xt[table->af].mutex);
 618
 619         return private;
 620 }
 621 EXPORT_SYMBOL_GPL(xt_unregister_table);
 622
 623 #ifdef CONFIG_PROC_FS
 624 static char *xt_proto_prefix[NPROTO] = {
 625         [AF_INET]       = "ip",
 626         [AF_INET6]      = "ip6",
 627         [NF_ARP]        = "arp",
 628 };
 629
 630 static struct list_head *xt_get_idx(struct list_head *list, struct seq_file *seq, loff_t pos)
 631 {
 632         struct list_head *head = list->next;
 633
 634         if (!head || list_empty(list))
 635                 return NULL;
 636
 637         while (pos && (head = head->next)) {
 638                 if (head == list)
 639                         return NULL;
 640                 pos--;
 641         }
 642         return pos ? NULL : head;
 643 }
 644
 645 static struct list_head *type2list(u_int16_t af, u_int16_t type)
 646 {
 647         struct list_head *list;
 648
 649         switch (type) {
 650         case TARGET:
 651                 list = &xt[af].target;
 652                 break;
 653         case MATCH:
 654                 list = &xt[af].match;
 655                 break;
 656         case TABLE:
 657                 list = &xt[af].tables;
 658                 break;
 659         default:
 660                 list = NULL;
 661                 break;
 662         }
 663
 664         return list;
 665 }
 666
 667 static void *xt_tgt_seq_start(struct seq_file *seq, loff_t *pos)
 668 {
 669         struct proc_dir_entry *pde = (struct proc_dir_entry *) seq->private;
 670         u_int16_t af = (unsigned long)pde->data & 0xffff;
 671         u_int16_t type = (unsigned long)pde->data >> 16;
 672         struct list_head *list;
 673
 674         if (af >= NPROTO)
 675                 return NULL;
 676
 677         list = type2list(af, type);
 678         if (!list)
 679                 return NULL;
 680
 681         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 682                 return NULL;
 683
 684         return xt_get_idx(list, seq, *pos);
 685 }
 686
 687 static void *xt_tgt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 688 {
 689         struct proc_dir_entry *pde = seq->private;
 690         u_int16_t af = (unsigned long)pde->data & 0xffff;
 691         u_int16_t type = (unsigned long)pde->data >> 16;
 692         struct list_head *list;
 693
 694         if (af >= NPROTO)
 695                 return NULL;
 696
 697         list = type2list(af, type);
 698         if (!list)
 699                 return NULL;
 700
 701         (*pos)++;
 702         return xt_get_idx(list, seq, *pos);
 703 }
 704
 705 static void xt_tgt_seq_stop(struct seq_file *seq, void *v)
 706 {
 707         struct proc_dir_entry *pde = seq->private;
 708         u_int16_t af = (unsigned long)pde->data & 0xffff;
 709
 710         mutex_unlock(&xt[af].mutex);
 711 }
 712
 713 static int xt_name_seq_show(struct seq_file *seq, void *v)
 714 {
 715         char *name = (char *)v + sizeof(struct list_head);
 716
 717         if (strlen(name))
 718                 return seq_printf(seq, "%s\n", name);
 719         else
 720                 return 0;
 721 }
 722
 723 static struct seq_operations xt_tgt_seq_ops = {
 724         .start  = xt_tgt_seq_start,
 725         .next   = xt_tgt_seq_next,
 726         .stop   = xt_tgt_seq_stop,
 727         .show   = xt_name_seq_show,
 728 };
 729
 730 static int xt_tgt_open(struct inode *inode, struct file *file)
 731 {
 732         int ret;
 733
 734         ret = seq_open(file, &xt_tgt_seq_ops);
 735         if (!ret) {
 736                 struct seq_file *seq = file->private_data;
 737                 struct proc_dir_entry *pde = PDE(inode);
 738
 739                 seq->private = pde;
 740         }
 741
 742         return ret;
 743 }
 744
 745 static struct file_operations xt_file_ops = {
 746         .owner   = THIS_MODULE,
 747         .open    = xt_tgt_open,
 748         .read    = seq_read,
 749         .llseek  = seq_lseek,
 750         .release = seq_release,
 751 };
 752
 753 #define FORMAT_TABLES   "_tables_names"
 754 #define FORMAT_MATCHES  "_tables_matches"
 755 #define FORMAT_TARGETS  "_tables_targets"
 756
 757 #endif /* CONFIG_PROC_FS */
 758
 759 int xt_proto_init(int af)
 760 {
 761 #ifdef CONFIG_PROC_FS
 762         char buf[XT_FUNCTION_MAXNAMELEN];
 763         struct proc_dir_entry *proc;
 764 #endif
 765
 766         if (af >= NPROTO)
 767                 return -EINVAL;
 768
 769
 770 #ifdef CONFIG_PROC_FS
 771         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 772         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 773         proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
 774         if (!proc)
 775                 goto out;
 776         proc->data = (void *) ((unsigned long) af | (TABLE << 16));
 777
 778
 779         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 780         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 781         proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
 782         if (!proc)
 783                 goto out_remove_tables;
 784         proc->data = (void *) ((unsigned long) af | (MATCH << 16));
 785
 786         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 787         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 788         proc = proc_net_fops_create(buf, 0440, &xt_file_ops);
 789         if (!proc)
 790                 goto out_remove_matches;
 791         proc->data = (void *) ((unsigned long) af | (TARGET << 16));
 792 #endif
 793
 794         return 0;
 795
 796 #ifdef CONFIG_PROC_FS
 797 out_remove_matches:
 798         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 799         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 800         proc_net_remove(buf);
 801
 802 out_remove_tables:
 803         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 804         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 805         proc_net_remove(buf);
 806 out:
 807         return -1;
 808 #endif
 809 }
 810 EXPORT_SYMBOL_GPL(xt_proto_init);
 811
 812 void xt_proto_fini(int af)
 813 {
 814 #ifdef CONFIG_PROC_FS
 815         char buf[XT_FUNCTION_MAXNAMELEN];
 816
 817         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 818         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 819         proc_net_remove(buf);
 820
 821         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 822         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 823         proc_net_remove(buf);
 824
 825         strlcpy(buf, xt_proto_prefix[af], sizeof(buf));
 826         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 827         proc_net_remove(buf);
 828 #endif /*CONFIG_PROC_FS*/
 829 }
 830 EXPORT_SYMBOL_GPL(xt_proto_fini);
 831
 832
 833 static int __init xt_init(void)
 834 {
 835         int i;
 836
 837         xt = kmalloc(sizeof(struct xt_af) * NPROTO, GFP_KERNEL);
 838         if (!xt)
 839                 return -ENOMEM;
 840
 841         for (i = 0; i < NPROTO; i++) {
 842                 mutex_init(&xt[i].mutex);
 843 #ifdef CONFIG_COMPAT
 844                 mutex_init(&xt[i].compat_mutex);
 845 #endif
 846                 INIT_LIST_HEAD(&xt[i].target);
 847                 INIT_LIST_HEAD(&xt[i].match);
 848                 INIT_LIST_HEAD(&xt[i].tables);
 849         }
 850         return 0;
 851 }
 852
 853 static void __exit xt_fini(void)
 854 {
 855         kfree(xt);
 856 }
 857
 858 module_init(xt_init);
 859 module_exit(xt_fini);
 860