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 *const 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         const 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         const 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(const 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         const 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         const 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(const 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         const 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         const 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 struct xt_names_priv {
 724         struct seq_net_private p;
 725         int af;
 726 };
 727 static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
 728 {
 729         struct xt_names_priv *priv = seq->private;
 730         struct net *net = seq_file_net(seq);
 731         int af = priv->af;
 732
 733         mutex_lock(&xt[af].mutex);
 734         return seq_list_start(&net->xt.tables[af], *pos);
 735 }
 736
 737 static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 738 {
 739         struct xt_names_priv *priv = seq->private;
 740         struct net *net = seq_file_net(seq);
 741         int af = priv->af;
 742
 743         return seq_list_next(v, &net->xt.tables[af], pos);
 744 }
 745
 746 static void xt_table_seq_stop(struct seq_file *seq, void *v)
 747 {
 748         struct xt_names_priv *priv = seq->private;
 749         int af = priv->af;
 750
 751         mutex_unlock(&xt[af].mutex);
 752 }
 753
 754 static int xt_table_seq_show(struct seq_file *seq, void *v)
 755 {
 756         struct xt_table *table = list_entry(v, struct xt_table, list);
 757
 758         if (strlen(table->name))
 759                 return seq_printf(seq, "%s\n", table->name);
 760         else
 761                 return 0;
 762 }
 763
 764 static const struct seq_operations xt_table_seq_ops = {
 765         .start  = xt_table_seq_start,
 766         .next   = xt_table_seq_next,
 767         .stop   = xt_table_seq_stop,
 768         .show   = xt_table_seq_show,
 769 };
 770
 771 static int xt_table_open(struct inode *inode, struct file *file)
 772 {
 773         int ret;
 774         struct xt_names_priv *priv;
 775
 776         ret = seq_open_net(inode, file, &xt_table_seq_ops,
 777                            sizeof(struct xt_names_priv));
 778         if (!ret) {
 779                 priv = ((struct seq_file *)file->private_data)->private;
 780                 priv->af = (unsigned long)PDE(inode)->data;
 781         }
 782         return ret;
 783 }
 784
 785 static const struct file_operations xt_table_ops = {
 786         .owner   = THIS_MODULE,
 787         .open    = xt_table_open,
 788         .read    = seq_read,
 789         .llseek  = seq_lseek,
 790         .release = seq_release_net,
 791 };
 792
 793 static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
 794 {
 795         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
 796         u_int16_t af = (unsigned long)pde->data;
 797
 798         mutex_lock(&xt[af].mutex);
 799         return seq_list_start(&xt[af].match, *pos);
 800 }
 801
 802 static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 803 {
 804         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
 805         u_int16_t af = (unsigned long)pde->data;
 806
 807         return seq_list_next(v, &xt[af].match, pos);
 808 }
 809
 810 static void xt_match_seq_stop(struct seq_file *seq, void *v)
 811 {
 812         struct proc_dir_entry *pde = seq->private;
 813         u_int16_t af = (unsigned long)pde->data;
 814
 815         mutex_unlock(&xt[af].mutex);
 816 }
 817
 818 static int xt_match_seq_show(struct seq_file *seq, void *v)
 819 {
 820         struct xt_match *match = list_entry(v, struct xt_match, list);
 821
 822         if (strlen(match->name))
 823                 return seq_printf(seq, "%s\n", match->name);
 824         else
 825                 return 0;
 826 }
 827
 828 static const struct seq_operations xt_match_seq_ops = {
 829         .start  = xt_match_seq_start,
 830         .next   = xt_match_seq_next,
 831         .stop   = xt_match_seq_stop,
 832         .show   = xt_match_seq_show,
 833 };
 834
 835 static int xt_match_open(struct inode *inode, struct file *file)
 836 {
 837         int ret;
 838
 839         ret = seq_open(file, &xt_match_seq_ops);
 840         if (!ret) {
 841                 struct seq_file *seq = file->private_data;
 842
 843                 seq->private = PDE(inode);
 844         }
 845         return ret;
 846 }
 847
 848 static const struct file_operations xt_match_ops = {
 849         .owner   = THIS_MODULE,
 850         .open    = xt_match_open,
 851         .read    = seq_read,
 852         .llseek  = seq_lseek,
 853         .release = seq_release,
 854 };
 855
 856 static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
 857 {
 858         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
 859         u_int16_t af = (unsigned long)pde->data;
 860
 861         mutex_lock(&xt[af].mutex);
 862         return seq_list_start(&xt[af].target, *pos);
 863 }
 864
 865 static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 866 {
 867         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
 868         u_int16_t af = (unsigned long)pde->data;
 869
 870         return seq_list_next(v, &xt[af].target, pos);
 871 }
 872
 873 static void xt_target_seq_stop(struct seq_file *seq, void *v)
 874 {
 875         struct proc_dir_entry *pde = seq->private;
 876         u_int16_t af = (unsigned long)pde->data;
 877
 878         mutex_unlock(&xt[af].mutex);
 879 }
 880
 881 static int xt_target_seq_show(struct seq_file *seq, void *v)
 882 {
 883         struct xt_target *target = list_entry(v, struct xt_target, list);
 884
 885         if (strlen(target->name))
 886                 return seq_printf(seq, "%s\n", target->name);
 887         else
 888                 return 0;
 889 }
 890
 891 static const struct seq_operations xt_target_seq_ops = {
 892         .start  = xt_target_seq_start,
 893         .next   = xt_target_seq_next,
 894         .stop   = xt_target_seq_stop,
 895         .show   = xt_target_seq_show,
 896 };
 897
 898 static int xt_target_open(struct inode *inode, struct file *file)
 899 {
 900         int ret;
 901
 902         ret = seq_open(file, &xt_target_seq_ops);
 903         if (!ret) {
 904                 struct seq_file *seq = file->private_data;
 905
 906                 seq->private = PDE(inode);
 907         }
 908         return ret;
 909 }
 910
 911 static const struct file_operations xt_target_ops = {
 912         .owner   = THIS_MODULE,
 913         .open    = xt_target_open,
 914         .read    = seq_read,
 915         .llseek  = seq_lseek,
 916         .release = seq_release,
 917 };
 918
 919 #define FORMAT_TABLES   "_tables_names"
 920 #define FORMAT_MATCHES  "_tables_matches"
 921 #define FORMAT_TARGETS  "_tables_targets"
 922
 923 #endif /* CONFIG_PROC_FS */
 924
 925 int xt_proto_init(struct net *net, int af)
 926 {
 927 #ifdef CONFIG_PROC_FS
 928         char buf[XT_FUNCTION_MAXNAMELEN];
 929         struct proc_dir_entry *proc;
 930 #endif
 931
 932         if (af >= NPROTO)
 933                 return -EINVAL;
 934
 935
 936 #ifdef CONFIG_PROC_FS
 937         strlcpy(buf, xt_prefix[af], sizeof(buf));
 938         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 939         proc = proc_create_data(buf, 0440, net->proc_net, &xt_table_ops,
 940                                 (void *)(unsigned long)af);
 941         if (!proc)
 942                 goto out;
 943
 944         strlcpy(buf, xt_prefix[af], sizeof(buf));
 945         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 946         proc = proc_create_data(buf, 0440, net->proc_net, &xt_match_ops,
 947                                 (void *)(unsigned long)af);
 948         if (!proc)
 949                 goto out_remove_tables;
 950
 951         strlcpy(buf, xt_prefix[af], sizeof(buf));
 952         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 953         proc = proc_create_data(buf, 0440, net->proc_net, &xt_target_ops,
 954                                 (void *)(unsigned long)af);
 955         if (!proc)
 956                 goto out_remove_matches;
 957 #endif
 958
 959         return 0;
 960
 961 #ifdef CONFIG_PROC_FS
 962 out_remove_matches:
 963         strlcpy(buf, xt_prefix[af], sizeof(buf));
 964         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 965         proc_net_remove(net, buf);
 966
 967 out_remove_tables:
 968         strlcpy(buf, xt_prefix[af], sizeof(buf));
 969         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 970         proc_net_remove(net, buf);
 971 out:
 972         return -1;
 973 #endif
 974 }
 975 EXPORT_SYMBOL_GPL(xt_proto_init);
 976
 977 void xt_proto_fini(struct net *net, int af)
 978 {
 979 #ifdef CONFIG_PROC_FS
 980         char buf[XT_FUNCTION_MAXNAMELEN];
 981
 982         strlcpy(buf, xt_prefix[af], sizeof(buf));
 983         strlcat(buf, FORMAT_TABLES, sizeof(buf));
 984         proc_net_remove(net, buf);
 985
 986         strlcpy(buf, xt_prefix[af], sizeof(buf));
 987         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 988         proc_net_remove(net, buf);
 989
 990         strlcpy(buf, xt_prefix[af], sizeof(buf));
 991         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 992         proc_net_remove(net, buf);
 993 #endif /*CONFIG_PROC_FS*/
 994 }
 995 EXPORT_SYMBOL_GPL(xt_proto_fini);
 996
 997 static int __net_init xt_net_init(struct net *net)
 998 {
 999         int i;
1000
1001         for (i = 0; i < NPROTO; i++)
1002                 INIT_LIST_HEAD(&net->xt.tables[i]);
1003         return 0;
1004 }
1005
1006 static struct pernet_operations xt_net_ops = {
1007         .init = xt_net_init,
1008 };
1009
1010 static int __init xt_init(void)
1011 {
1012         int i, rv;
1013
1014         xt = kmalloc(sizeof(struct xt_af) * NPROTO, GFP_KERNEL);
1015         if (!xt)
1016                 return -ENOMEM;
1017
1018         for (i = 0; i < NPROTO; i++) {
1019                 mutex_init(&xt[i].mutex);
1020 #ifdef CONFIG_COMPAT
1021                 mutex_init(&xt[i].compat_mutex);
1022                 xt[i].compat_offsets = NULL;
1023 #endif
1024                 INIT_LIST_HEAD(&xt[i].target);
1025                 INIT_LIST_HEAD(&xt[i].match);
1026         }
1027         rv = register_pernet_subsys(&xt_net_ops);
1028         if (rv < 0)
1029                 kfree(xt);
1030         return rv;
1031 }
1032
1033 static void __exit xt_fini(void)
1034 {
1035         unregister_pernet_subsys(&xt_net_ops);
1036         kfree(xt);
1037 }
1038
1039 module_init(xt_init);
1040 module_exit(xt_fini);
1041