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 compat_delta {
  38         struct compat_delta *next;
  39         unsigned int offset;
  40         short delta;
  41 };
  42
  43 struct xt_af {
  44         struct mutex mutex;
  45         struct list_head match;
  46         struct list_head target;
  47 #ifdef CONFIG_COMPAT
  48         struct mutex compat_mutex;
  49         struct compat_delta *compat_offsets;
  50 #endif
  51 };
  52
  53 static struct xt_af *xt;
  54
  55 #ifdef DEBUG_IP_FIREWALL_USER
  56 #define duprintf(format, args...) printk(format , ## args)
  57 #else
  58 #define duprintf(format, args...)
  59 #endif
  60
  61 static const char *xt_prefix[NPROTO] = {
  62         [AF_INET]       = "ip",
  63         [AF_INET6]      = "ip6",
  64         [NF_ARP]        = "arp",
  65 };
  66
  67 /* Registration hooks for targets. */
  68 int
  69 xt_register_target(struct xt_target *target)
  70 {
  71         int ret, af = target->family;
  72
  73         ret = mutex_lock_interruptible(&xt[af].mutex);
  74         if (ret != 0)
  75                 return ret;
  76         list_add(&target->list, &xt[af].target);
  77         mutex_unlock(&xt[af].mutex);
  78         return ret;
  79 }
  80 EXPORT_SYMBOL(xt_register_target);
  81
  82 void
  83 xt_unregister_target(struct xt_target *target)
  84 {
  85         int af = target->family;
  86
  87         mutex_lock(&xt[af].mutex);
  88         list_del(&target->list);
  89         mutex_unlock(&xt[af].mutex);
  90 }
  91 EXPORT_SYMBOL(xt_unregister_target);
  92
  93 int
  94 xt_register_targets(struct xt_target *target, unsigned int n)
  95 {
  96         unsigned int i;
  97         int err = 0;
  98
  99         for (i = 0; i < n; i++) {
 100                 err = xt_register_target(&target[i]);
 101                 if (err)
 102                         goto err;
 103         }
 104         return err;
 105
 106 err:
 107         if (i > 0)
 108                 xt_unregister_targets(target, i);
 109         return err;
 110 }
 111 EXPORT_SYMBOL(xt_register_targets);
 112
 113 void
 114 xt_unregister_targets(struct xt_target *target, unsigned int n)
 115 {
 116         unsigned int i;
 117
 118         for (i = 0; i < n; i++)
 119                 xt_unregister_target(&target[i]);
 120 }
 121 EXPORT_SYMBOL(xt_unregister_targets);
 122
 123 int
 124 xt_register_match(struct xt_match *match)
 125 {
 126         int ret, af = match->family;
 127
 128         ret = mutex_lock_interruptible(&xt[af].mutex);
 129         if (ret != 0)
 130                 return ret;
 131
 132         list_add(&match->list, &xt[af].match);
 133         mutex_unlock(&xt[af].mutex);
 134
 135         return ret;
 136 }
 137 EXPORT_SYMBOL(xt_register_match);
 138
 139 void
 140 xt_unregister_match(struct xt_match *match)
 141 {
 142         int af =  match->family;
 143
 144         mutex_lock(&xt[af].mutex);
 145         list_del(&match->list);
 146         mutex_unlock(&xt[af].mutex);
 147 }
 148 EXPORT_SYMBOL(xt_unregister_match);
 149
 150 int
 151 xt_register_matches(struct xt_match *match, unsigned int n)
 152 {
 153         unsigned int i;
 154         int err = 0;
 155
 156         for (i = 0; i < n; i++) {
 157                 err = xt_register_match(&match[i]);
 158                 if (err)
 159                         goto err;
 160         }
 161         return err;
 162
 163 err:
 164         if (i > 0)
 165                 xt_unregister_matches(match, i);
 166         return err;
 167 }
 168 EXPORT_SYMBOL(xt_register_matches);
 169
 170 void
 171 xt_unregister_matches(struct xt_match *match, unsigned int n)
 172 {
 173         unsigned int i;
 174
 175         for (i = 0; i < n; i++)
 176                 xt_unregister_match(&match[i]);
 177 }
 178 EXPORT_SYMBOL(xt_unregister_matches);
 179
 180
 181 /*
 182  * These are weird, but module loading must not be done with mutex
 183  * held (since they will register), and we have to have a single
 184  * function to use try_then_request_module().
 185  */
 186
 187 /* Find match, grabs ref.  Returns ERR_PTR() on error. */
 188 struct xt_match *xt_find_match(int af, const char *name, u8 revision)
 189 {
 190         struct xt_match *m;
 191         int err = 0;
 192
 193         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 194                 return ERR_PTR(-EINTR);
 195
 196         list_for_each_entry(m, &xt[af].match, list) {
 197                 if (strcmp(m->name, name) == 0) {
 198                         if (m->revision == revision) {
 199                                 if (try_module_get(m->me)) {
 200                                         mutex_unlock(&xt[af].mutex);
 201                                         return m;
 202                                 }
 203                         } else
 204                                 err = -EPROTOTYPE; /* Found something. */
 205                 }
 206         }
 207         mutex_unlock(&xt[af].mutex);
 208         return ERR_PTR(err);
 209 }
 210 EXPORT_SYMBOL(xt_find_match);
 211
 212 /* Find target, grabs ref.  Returns ERR_PTR() on error. */
 213 struct xt_target *xt_find_target(int af, const char *name, u8 revision)
 214 {
 215         struct xt_target *t;
 216         int err = 0;
 217
 218         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 219                 return ERR_PTR(-EINTR);
 220
 221         list_for_each_entry(t, &xt[af].target, list) {
 222                 if (strcmp(t->name, name) == 0) {
 223                         if (t->revision == revision) {
 224                                 if (try_module_get(t->me)) {
 225                                         mutex_unlock(&xt[af].mutex);
 226                                         return t;
 227                                 }
 228                         } else
 229                                 err = -EPROTOTYPE; /* Found something. */
 230                 }
 231         }
 232         mutex_unlock(&xt[af].mutex);
 233         return ERR_PTR(err);
 234 }
 235 EXPORT_SYMBOL(xt_find_target);
 236
 237 struct xt_target *xt_request_find_target(int af, const char *name, u8 revision)
 238 {
 239         struct xt_target *target;
 240
 241         target = try_then_request_module(xt_find_target(af, name, revision),
 242                                          "%st_%s", xt_prefix[af], name);
 243         if (IS_ERR(target) || !target)
 244                 return NULL;
 245         return target;
 246 }
 247 EXPORT_SYMBOL_GPL(xt_request_find_target);
 248
 249 static int match_revfn(int af, const char *name, u8 revision, int *bestp)
 250 {
 251         struct xt_match *m;
 252         int have_rev = 0;
 253
 254         list_for_each_entry(m, &xt[af].match, list) {
 255                 if (strcmp(m->name, name) == 0) {
 256                         if (m->revision > *bestp)
 257                                 *bestp = m->revision;
 258                         if (m->revision == revision)
 259                                 have_rev = 1;
 260                 }
 261         }
 262         return have_rev;
 263 }
 264
 265 static int target_revfn(int af, const char *name, u8 revision, int *bestp)
 266 {
 267         struct xt_target *t;
 268         int have_rev = 0;
 269
 270         list_for_each_entry(t, &xt[af].target, list) {
 271                 if (strcmp(t->name, name) == 0) {
 272                         if (t->revision > *bestp)
 273                                 *bestp = t->revision;
 274                         if (t->revision == revision)
 275                                 have_rev = 1;
 276                 }
 277         }
 278         return have_rev;
 279 }
 280
 281 /* Returns true or false (if no such extension at all) */
 282 int xt_find_revision(int af, const char *name, u8 revision, int target,
 283                      int *err)
 284 {
 285         int have_rev, best = -1;
 286
 287         if (mutex_lock_interruptible(&xt[af].mutex) != 0) {
 288                 *err = -EINTR;
 289                 return 1;
 290         }
 291         if (target == 1)
 292                 have_rev = target_revfn(af, name, revision, &best);
 293         else
 294                 have_rev = match_revfn(af, name, revision, &best);
 295         mutex_unlock(&xt[af].mutex);
 296
 297         /* Nothing at all?  Return 0 to try loading module. */
 298         if (best == -1) {
 299                 *err = -ENOENT;
 300                 return 0;
 301         }
 302
 303         *err = best;
 304         if (!have_rev)
 305                 *err = -EPROTONOSUPPORT;
 306         return 1;
 307 }
 308 EXPORT_SYMBOL_GPL(xt_find_revision);
 309
 310 int xt_check_match(const struct xt_match *match, unsigned short family,
 311                    unsigned int size, const char *table, unsigned int hook_mask,
 312                    unsigned short proto, int inv_proto)
 313 {
 314         if (XT_ALIGN(match->matchsize) != size) {
 315                 printk("%s_tables: %s match: invalid size %Zu != %u\n",
 316                        xt_prefix[family], match->name,
 317                        XT_ALIGN(match->matchsize), size);
 318                 return -EINVAL;
 319         }
 320         if (match->table && strcmp(match->table, table)) {
 321                 printk("%s_tables: %s match: only valid in %s table, not %s\n",
 322                        xt_prefix[family], match->name, match->table, table);
 323                 return -EINVAL;
 324         }
 325         if (match->hooks && (hook_mask & ~match->hooks) != 0) {
 326                 printk("%s_tables: %s match: bad hook_mask %u/%u\n",
 327                        xt_prefix[family], match->name, hook_mask, match->hooks);
 328                 return -EINVAL;
 329         }
 330         if (match->proto && (match->proto != proto || inv_proto)) {
 331                 printk("%s_tables: %s match: only valid for protocol %u\n",
 332                        xt_prefix[family], match->name, match->proto);
 333                 return -EINVAL;
 334         }
 335         return 0;
 336 }
 337 EXPORT_SYMBOL_GPL(xt_check_match);
 338
 339 #ifdef CONFIG_COMPAT
 340 int xt_compat_add_offset(int af, unsigned int offset, short delta)
 341 {
 342         struct compat_delta *tmp;
 343
 344         tmp = kmalloc(sizeof(struct compat_delta), GFP_KERNEL);
 345         if (!tmp)
 346                 return -ENOMEM;
 347
 348         tmp->offset = offset;
 349         tmp->delta = delta;
 350
 351         if (xt[af].compat_offsets) {
 352                 tmp->next = xt[af].compat_offsets->next;
 353                 xt[af].compat_offsets->next = tmp;
 354         } else {
 355                 xt[af].compat_offsets = tmp;
 356                 tmp->next = NULL;
 357         }
 358         return 0;
 359 }
 360 EXPORT_SYMBOL_GPL(xt_compat_add_offset);
 361
 362 void xt_compat_flush_offsets(int af)
 363 {
 364         struct compat_delta *tmp, *next;
 365
 366         if (xt[af].compat_offsets) {
 367                 for (tmp = xt[af].compat_offsets; tmp; tmp = next) {
 368                         next = tmp->next;
 369                         kfree(tmp);
 370                 }
 371                 xt[af].compat_offsets = NULL;
 372         }
 373 }
 374 EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
 375
 376 short xt_compat_calc_jump(int af, unsigned int offset)
 377 {
 378         struct compat_delta *tmp;
 379         short delta;
 380
 381         for (tmp = xt[af].compat_offsets, delta = 0; tmp; tmp = tmp->next)
 382                 if (tmp->offset < offset)
 383                         delta += tmp->delta;
 384         return delta;
 385 }
 386 EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
 387
 388 int xt_compat_match_offset(struct xt_match *match)
 389 {
 390         u_int16_t csize = match->compatsize ? : match->matchsize;
 391         return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
 392 }
 393 EXPORT_SYMBOL_GPL(xt_compat_match_offset);
 394
 395 int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
 396                               unsigned int *size)
 397 {
 398         struct xt_match *match = m->u.kernel.match;
 399         struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
 400         int pad, off = xt_compat_match_offset(match);
 401         u_int16_t msize = cm->u.user.match_size;
 402
 403         m = *dstptr;
 404         memcpy(m, cm, sizeof(*cm));
 405         if (match->compat_from_user)
 406                 match->compat_from_user(m->data, cm->data);
 407         else
 408                 memcpy(m->data, cm->data, msize - sizeof(*cm));
 409         pad = XT_ALIGN(match->matchsize) - match->matchsize;
 410         if (pad > 0)
 411                 memset(m->data + match->matchsize, 0, pad);
 412
 413         msize += off;
 414         m->u.user.match_size = msize;
 415
 416         *size += off;
 417         *dstptr += msize;
 418         return 0;
 419 }
 420 EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
 421
 422 int xt_compat_match_to_user(struct xt_entry_match *m, void __user **dstptr,
 423                             unsigned int *size)
 424 {
 425         struct xt_match *match = m->u.kernel.match;
 426         struct compat_xt_entry_match __user *cm = *dstptr;
 427         int off = xt_compat_match_offset(match);
 428         u_int16_t msize = m->u.user.match_size - off;
 429
 430         if (copy_to_user(cm, m, sizeof(*cm)) ||
 431             put_user(msize, &cm->u.user.match_size) ||
 432             copy_to_user(cm->u.user.name, m->u.kernel.match->name,
 433                          strlen(m->u.kernel.match->name) + 1))
 434                 return -EFAULT;
 435
 436         if (match->compat_to_user) {
 437                 if (match->compat_to_user((void __user *)cm->data, m->data))
 438                         return -EFAULT;
 439         } else {
 440                 if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
 441                         return -EFAULT;
 442         }
 443
 444         *size -= off;
 445         *dstptr += msize;
 446         return 0;
 447 }
 448 EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
 449 #endif /* CONFIG_COMPAT */
 450
 451 int xt_check_target(const struct xt_target *target, unsigned short family,
 452                     unsigned int size, const char *table, unsigned int hook_mask,
 453                     unsigned short proto, int inv_proto)
 454 {
 455         if (XT_ALIGN(target->targetsize) != size) {
 456                 printk("%s_tables: %s target: invalid size %Zu != %u\n",
 457                        xt_prefix[family], target->name,
 458                        XT_ALIGN(target->targetsize), size);
 459                 return -EINVAL;
 460         }
 461         if (target->table && strcmp(target->table, table)) {
 462                 printk("%s_tables: %s target: only valid in %s table, not %s\n",
 463                        xt_prefix[family], target->name, target->table, table);
 464                 return -EINVAL;
 465         }
 466         if (target->hooks && (hook_mask & ~target->hooks) != 0) {
 467                 printk("%s_tables: %s target: bad hook_mask %u/%u\n",
 468                        xt_prefix[family], target->name, hook_mask,
 469                        target->hooks);
 470                 return -EINVAL;
 471         }
 472         if (target->proto && (target->proto != proto || inv_proto)) {
 473                 printk("%s_tables: %s target: only valid for protocol %u\n",
 474                        xt_prefix[family], target->name, target->proto);
 475                 return -EINVAL;
 476         }
 477         return 0;
 478 }
 479 EXPORT_SYMBOL_GPL(xt_check_target);
 480
 481 #ifdef CONFIG_COMPAT
 482 int xt_compat_target_offset(struct xt_target *target)
 483 {
 484         u_int16_t csize = target->compatsize ? : target->targetsize;
 485         return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
 486 }
 487 EXPORT_SYMBOL_GPL(xt_compat_target_offset);
 488
 489 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
 490                                 unsigned int *size)
 491 {
 492         struct xt_target *target = t->u.kernel.target;
 493         struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
 494         int pad, off = xt_compat_target_offset(target);
 495         u_int16_t tsize = ct->u.user.target_size;
 496
 497         t = *dstptr;
 498         memcpy(t, ct, sizeof(*ct));
 499         if (target->compat_from_user)
 500                 target->compat_from_user(t->data, ct->data);
 501         else
 502                 memcpy(t->data, ct->data, tsize - sizeof(*ct));
 503         pad = XT_ALIGN(target->targetsize) - target->targetsize;
 504         if (pad > 0)
 505                 memset(t->data + target->targetsize, 0, pad);
 506
 507         tsize += off;
 508         t->u.user.target_size = tsize;
 509
 510         *size += off;
 511         *dstptr += tsize;
 512 }
 513 EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
 514
 515 int xt_compat_target_to_user(struct xt_entry_target *t, void __user **dstptr,
 516                              unsigned int *size)
 517 {
 518         struct xt_target *target = t->u.kernel.target;
 519         struct compat_xt_entry_target __user *ct = *dstptr;
 520         int off = xt_compat_target_offset(target);
 521         u_int16_t tsize = t->u.user.target_size - off;
 522
 523         if (copy_to_user(ct, t, sizeof(*ct)) ||
 524             put_user(tsize, &ct->u.user.target_size) ||
 525             copy_to_user(ct->u.user.name, t->u.kernel.target->name,
 526                          strlen(t->u.kernel.target->name) + 1))
 527                 return -EFAULT;
 528
 529         if (target->compat_to_user) {
 530                 if (target->compat_to_user((void __user *)ct->data, t->data))
 531                         return -EFAULT;
 532         } else {
 533                 if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
 534                         return -EFAULT;
 535         }
 536
 537         *size -= off;
 538         *dstptr += tsize;
 539         return 0;
 540 }
 541 EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
 542 #endif
 543
 544 struct xt_table_info *xt_alloc_table_info(unsigned int size)
 545 {
 546         struct xt_table_info *newinfo;
 547         int cpu;
 548
 549         /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
 550         if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
 551                 return NULL;
 552
 553         newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
 554         if (!newinfo)
 555                 return NULL;
 556
 557         newinfo->size = size;
 558
 559         for_each_possible_cpu(cpu) {
 560                 if (size <= PAGE_SIZE)
 561                         newinfo->entries[cpu] = kmalloc_node(size,
 562                                                         GFP_KERNEL,
 563                                                         cpu_to_node(cpu));
 564                 else
 565                         newinfo->entries[cpu] = vmalloc_node(size,
 566                                                         cpu_to_node(cpu));
 567
 568                 if (newinfo->entries[cpu] == NULL) {
 569                         xt_free_table_info(newinfo);
 570                         return NULL;
 571                 }
 572         }
 573
 574         return newinfo;
 575 }
 576 EXPORT_SYMBOL(xt_alloc_table_info);
 577
 578 void xt_free_table_info(struct xt_table_info *info)
 579 {
 580         int cpu;
 581
 582         for_each_possible_cpu(cpu) {
 583                 if (info->size <= PAGE_SIZE)
 584                         kfree(info->entries[cpu]);
 585                 else
 586                         vfree(info->entries[cpu]);
 587         }
 588         kfree(info);
 589 }
 590 EXPORT_SYMBOL(xt_free_table_info);
 591
 592 /* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
 593 struct xt_table *xt_find_table_lock(struct net *net, int af, const char *name)
 594 {
 595         struct xt_table *t;
 596
 597         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
 598                 return ERR_PTR(-EINTR);
 599
 600         list_for_each_entry(t, &net->xt.tables[af], list)
 601                 if (strcmp(t->name, name) == 0 && try_module_get(t->me))
 602                         return t;
 603         mutex_unlock(&xt[af].mutex);
 604         return NULL;
 605 }
 606 EXPORT_SYMBOL_GPL(xt_find_table_lock);
 607
 608 void xt_table_unlock(struct xt_table *table)
 609 {
 610         mutex_unlock(&xt[table->af].mutex);
 611 }
 612 EXPORT_SYMBOL_GPL(xt_table_unlock);
 613
 614 #ifdef CONFIG_COMPAT
 615 void xt_compat_lock(int af)
 616 {
 617         mutex_lock(&xt[af].compat_mutex);
 618 }
 619 EXPORT_SYMBOL_GPL(xt_compat_lock);
 620
 621 void xt_compat_unlock(int af)
 622 {
 623         mutex_unlock(&xt[af].compat_mutex);
 624 }
 625 EXPORT_SYMBOL_GPL(xt_compat_unlock);
 626 #endif
 627
 628 struct xt_table_info *
 629 xt_replace_table(struct xt_table *table,
 630               unsigned int num_counters,
 631               struct xt_table_info *newinfo,
 632               int *error)
 633 {
 634         struct xt_table_info *oldinfo, *private;
 635
 636         /* Do the substitution. */
 637         write_lock_bh(&table->lock);
 638         private = table->private;
 639         /* Check inside lock: is the old number correct? */
 640         if (num_counters != private->number) {
 641                 duprintf("num_counters != table->private->number (%u/%u)\n",
 642                          num_counters, private->number);
 643                 write_unlock_bh(&table->lock);
 644                 *error = -EAGAIN;
 645                 return NULL;
 646         }
 647         oldinfo = private;
 648         table->private = newinfo;
 649         newinfo->initial_entries = oldinfo->initial_entries;
 650         write_unlock_bh(&table->lock);
 651
 652         return oldinfo;
 653 }
 654 EXPORT_SYMBOL_GPL(xt_replace_table);
 655
 656 struct xt_table *xt_register_table(struct net *net, struct xt_table *table,
 657                                    struct xt_table_info *bootstrap,
 658                                    struct xt_table_info *newinfo)
 659 {
 660         int ret;
 661         struct xt_table_info *private;
 662         struct xt_table *t;
 663
 664         /* Don't add one object to multiple lists. */
 665         table = kmemdup(table, sizeof(struct xt_table), GFP_KERNEL);
 666         if (!table) {
 667                 ret = -ENOMEM;
 668                 goto out;
 669         }
 670
 671         ret = mutex_lock_interruptible(&xt[table->af].mutex);
 672         if (ret != 0)
 673                 goto out_free;
 674
 675         /* Don't autoload: we'd eat our tail... */
 676         list_for_each_entry(t, &net->xt.tables[table->af], list) {
 677                 if (strcmp(t->name, table->name) == 0) {
 678                         ret = -EEXIST;
 679                         goto unlock;
 680                 }
 681         }
 682
 683         /* Simplifies replace_table code. */
 684         table->private = bootstrap;
 685         rwlock_init(&table->lock);
 686         if (!xt_replace_table(table, 0, newinfo, &ret))
 687                 goto unlock;
 688
 689         private = table->private;
 690         duprintf("table->private->number = %u\n", private->number);
 691
 692         /* save number of initial entries */
 693         private->initial_entries = private->number;
 694
 695         list_add(&table->list, &net->xt.tables[table->af]);
 696         mutex_unlock(&xt[table->af].mutex);
 697         return table;
 698
 699  unlock:
 700         mutex_unlock(&xt[table->af].mutex);
 701 out_free:
 702         kfree(table);
 703 out:
 704         return ERR_PTR(ret);
 705 }
 706 EXPORT_SYMBOL_GPL(xt_register_table);
 707
 708 void *xt_unregister_table(struct xt_table *table)
 709 {
 710         struct xt_table_info *private;
 711
 712         mutex_lock(&xt[table->af].mutex);
 713         private = table->private;
 714         list_del(&table->list);
 715         mutex_unlock(&xt[table->af].mutex);
 716         kfree(table);
 717
 718         return private;
 719 }
 720 EXPORT_SYMBOL_GPL(xt_unregister_table);
 721
 722 #ifdef CONFIG_PROC_FS
 723 static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
 724 {
 725         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
 726         u_int16_t af = (unsigned long)pde->data;
 727
 728         mutex_lock(&xt[af].mutex);
 729         return seq_list_start(&init_net.xt.tables[af], *pos);
 730 }
 731
 732 static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 733 {
 734         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
 735         u_int16_t af = (unsigned long)pde->data;
 736
 737         return seq_list_next(v, &init_net.xt.tables[af], pos);
 738 }
 739
 740 static void xt_table_seq_stop(struct seq_file *seq, void *v)
 741 {
 742         struct proc_dir_entry *pde = seq->private;
 743         u_int16_t af = (unsigned long)pde->data;
 744
 745         mutex_unlock(&xt[af].mutex);
 746 }
 747
 748 static int xt_table_seq_show(struct seq_file *seq, void *v)
 749 {
 750         struct xt_table *table = list_entry(v, struct xt_table, list);
 751
 752         if (strlen(table->name))
 753                 return seq_printf(seq, "%s\n", table->name);
 754         else
 755                 return 0;
 756 }
 757
 758 static const struct seq_operations xt_table_seq_ops = {
 759         .start  = xt_table_seq_start,
 760         .next   = xt_table_seq_next,
 761         .stop   = xt_table_seq_stop,
 762         .show   = xt_table_seq_show,
 763 };
 764
 765 static int xt_table_open(struct inode *inode, struct file *file)
 766 {
 767         int ret;
 768
 769         ret = seq_open(file, &xt_table_seq_ops);
 770         if (!ret) {
 771                 struct seq_file *seq = file->private_data;
 772
 773                 seq->private = PDE(inode);
 774         }
 775         return ret;
 776 }
 777
 778 static const struct file_operations xt_table_ops = {
 779         .owner   = THIS_MODULE,
 780         .open    = xt_table_open,
 781         .read    = seq_read,
 782         .llseek  = seq_lseek,
 783         .release = seq_release,
 784 };
 785
 786 static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
 787 {
 788         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
 789         u_int16_t af = (unsigned long)pde->data;
 790
 791         mutex_lock(&xt[af].mutex);
 792         return seq_list_start(&xt[af].match, *pos);
 793 }
 794
 795 static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 796 {
 797         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
 798         u_int16_t af = (unsigned long)pde->data;
 799
 800         return seq_list_next(v, &xt[af].match, pos);
 801 }
 802
 803 static void xt_match_seq_stop(struct seq_file *seq, void *v)
 804 {
 805         struct proc_dir_entry *pde = seq->private;
 806         u_int16_t af = (unsigned long)pde->data;
 807
 808         mutex_unlock(&xt[af].mutex);
 809 }
 810
 811 static int xt_match_seq_show(struct seq_file *seq, void *v)
 812 {
 813         struct xt_match *match = list_entry(v, struct xt_match, list);
 814
 815         if (strlen(match->name))
 816                 return seq_printf(seq, "%s\n", match->name);
 817         else
 818                 return 0;
 819 }
 820
 821 static const struct seq_operations xt_match_seq_ops = {
 822         .start  = xt_match_seq_start,
 823         .next   = xt_match_seq_next,
 824         .stop   = xt_match_seq_stop,
 825         .show   = xt_match_seq_show,
 826 };
 827
 828 static int xt_match_open(struct inode *inode, struct file *file)
 829 {
 830         int ret;
 831
 832         ret = seq_open(file, &xt_match_seq_ops);
 833         if (!ret) {
 834                 struct seq_file *seq = file->private_data;
 835
 836                 seq->private = PDE(inode);
 837         }
 838         return ret;
 839 }
 840
 841 static const struct file_operations xt_match_ops = {
 842         .owner   = THIS_MODULE,
 843         .open    = xt_match_open,
 844         .read    = seq_read,
 845         .llseek  = seq_lseek,
 846         .release = seq_release,
 847 };
 848
 849 static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
 850 {
 851         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
 852         u_int16_t af = (unsigned long)pde->data;
 853
 854         mutex_lock(&xt[af].mutex);
 855         return seq_list_start(&xt[af].target, *pos);
 856 }
 857
 858 static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 859 {
 860         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
 861         u_int16_t af = (unsigned long)pde->data;
 862
 863         return seq_list_next(v, &xt[af].target, pos);
 864 }
 865
 866 static void xt_target_seq_stop(struct seq_file *seq, void *v)
 867 {
 868         struct proc_dir_entry *pde = seq->private;
 869         u_int16_t af = (unsigned long)pde->data;
 870
 871         mutex_unlock(&xt[af].mutex);
 872 }
 873
 874 static int xt_target_seq_show(struct seq_file *seq, void *v)
 875 {
 876         struct xt_target *target = list_entry(v, struct xt_target, list);
 877
 878         if (strlen(target->name))
 879                 return seq_printf(seq, "%s\n", target->name);
 880         else
 881                 return 0;
 882 }
 883
 884 static const struct seq_operations xt_target_seq_ops = {
 885         .start  = xt_target_seq_start,
 886         .next   = xt_target_seq_next,
 887         .stop   = xt_target_seq_stop,
 888         .show   = xt_target_seq_show,
 889 };
 890
 891 static int xt_target_open(struct inode *inode, struct file *file)
 892 {
 893         int ret;
 894
 895         ret = seq_open(file, &xt_target_seq_ops);
 896         if (!ret) {
 897                 struct seq_file *seq = file->private_data;
 898
 899                 seq->private = PDE(inode);
 900         }
 901         return ret;
 902 }
 903
 904 static const struct file_operations xt_target_ops = {
 905         .owner   = THIS_MODULE,
 906         .open    = xt_target_open,
 907         .read    = seq_read,
 908         .llseek  = seq_lseek,
 909         .release = seq_release,
 910 };
 911
 912 #define FORMAT_TABLES   "_tables_names"
 913 #define FORMAT_MATCHES  "_tables_matches"
 914 #define FORMAT_TARGETS  "_tables_targets"
 915
 916 #endif /* CONFIG_PROC_FS */
 917
 918 int xt_proto_init(int af)
 919 {
 920 #ifdef CONFIG_PROC_FS
 921         char buf[XT_FUNCTION_MAXNAMELEN];
 922         struct proc_dir_entry *proc;
 923 #endif
 924
 925         if (af >= NPROTO)
 926                 return -EINVAL;
 927
 928
 929 #ifdef CONFIG_PROC_FS
 930         strlcpy(buf, xt_prefix[af], sizeof(buf));
 931         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 932         proc = proc_net_fops_create(&init_net, buf, 0440, &xt_table_ops);
 933         if (!proc)
 934                 goto out;
 935         proc->data = (void *)(unsigned long)af;
 936
 937
 938         strlcpy(buf, xt_prefix[af], sizeof(buf));
 939         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 940         proc = proc_net_fops_create(&init_net, buf, 0440, &xt_match_ops);
 941         if (!proc)
 942                 goto out_remove_tables;
 943         proc->data = (void *)(unsigned long)af;
 944
 945         strlcpy(buf, xt_prefix[af], sizeof(buf));
 946         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 947         proc = proc_net_fops_create(&init_net, buf, 0440, &xt_target_ops);
 948         if (!proc)
 949                 goto out_remove_matches;
 950         proc->data = (void *)(unsigned long)af;
 951 #endif
 952
 953         return 0;
 954
 955 #ifdef CONFIG_PROC_FS
 956 out_remove_matches:
 957         strlcpy(buf, xt_prefix[af], sizeof(buf));
 958         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 959         proc_net_remove(&init_net, buf);
 960
 961 out_remove_tables:
 962         strlcpy(buf, xt_prefix[af], sizeof(buf));
 963         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 964         proc_net_remove(&init_net, buf);
 965 out:
 966         return -1;
 967 #endif
 968 }
 969 EXPORT_SYMBOL_GPL(xt_proto_init);
 970
 971 void xt_proto_fini(int af)
 972 {
 973 #ifdef CONFIG_PROC_FS
 974         char buf[XT_FUNCTION_MAXNAMELEN];
 975
 976         strlcpy(buf, xt_prefix[af], sizeof(buf));
 977         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 978         proc_net_remove(&init_net, buf);
 979
 980         strlcpy(buf, xt_prefix[af], sizeof(buf));
 981         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 982         proc_net_remove(&init_net, buf);
 983
 984         strlcpy(buf, xt_prefix[af], sizeof(buf));
 985         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 986         proc_net_remove(&init_net, buf);
 987 #endif /*CONFIG_PROC_FS*/
 988 }
 989 EXPORT_SYMBOL_GPL(xt_proto_fini);
 990
 991 static int __net_init xt_net_init(struct net *net)
 992 {
 993         int i;
 994
 995         for (i = 0; i < NPROTO; i++)
 996                 INIT_LIST_HEAD(&net->xt.tables[i]);
 997         return 0;
 998 }
 999
1000 static struct pernet_operations xt_net_ops = {
1001         .init = xt_net_init,
1002 };
1003
1004 static int __init xt_init(void)
1005 {
1006         int i, rv;
1007
1008         xt = kmalloc(sizeof(struct xt_af) * NPROTO, GFP_KERNEL);
1009         if (!xt)
1010                 return -ENOMEM;
1011
1012         for (i = 0; i < NPROTO; i++) {
1013                 mutex_init(&xt[i].mutex);
1014 #ifdef CONFIG_COMPAT
1015                 mutex_init(&xt[i].compat_mutex);
1016                 xt[i].compat_offsets = NULL;
1017 #endif
1018                 INIT_LIST_HEAD(&xt[i].target);
1019                 INIT_LIST_HEAD(&xt[i].match);
1020         }
1021         rv = register_pernet_subsys(&xt_net_ops);
1022         if (rv < 0)
1023                 kfree(xt);
1024         return rv;
1025 }
1026
1027 static void __exit xt_fini(void)
1028 {
1029         unregister_pernet_subsys(&xt_net_ops);
1030         kfree(xt);
1031 }
1032
1033 module_init(xt_init);
1034 module_exit(xt_fini);
1035