ClabureDB: Classified Bug-Reports Database

   /*
    * x_tables core - Backend for {ip,ip6,arp}_tables
    *
    * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
    *
    * Based on existing ip_tables code which is
    *   Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
    *   Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
    *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/socket.h>
  #include <linux/net.h>
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>
  #include <linux/string.h>
  #include <linux/vmalloc.h>
  #include <linux/mutex.h>
  #include <linux/mm.h>
  #include <net/net_namespace.h>
  
  #include <linux/netfilter/x_tables.h>
  #include <linux/netfilter_arp.h>
  
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
  MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
  
  #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
  
  struct compat_delta {
          struct compat_delta *next;
          unsigned int offset;
          short delta;
  };
  
  struct xt_af {
          struct mutex mutex;
          struct list_head match;
          struct list_head target;
  #ifdef CONFIG_COMPAT
          struct mutex compat_mutex;
          struct compat_delta *compat_offsets;
  #endif
  };
  
  static struct xt_af *xt;
  
  #ifdef DEBUG_IP_FIREWALL_USER
  #define duprintf(format, args...) printk(format , ## args)
  #else
  #define duprintf(format, args...)
  #endif
  
  static const char *const xt_prefix[NFPROTO_NUMPROTO] = {
          [NFPROTO_UNSPEC] = "x",
          [NFPROTO_IPV4]   = "ip",
          [NFPROTO_ARP]    = "arp",
          [NFPROTO_BRIDGE] = "eb",
          [NFPROTO_IPV6]   = "ip6",
  };
  
  /* Registration hooks for targets. */
  int
  xt_register_target(struct xt_target *target)
  {
          u_int8_t af = target->family;
          int ret;
  
          ret = mutex_lock_interruptible(&xt[af].mutex);
          if (ret != 0)
                  return ret;
          list_add(&target->list, &xt[af].target);
          mutex_unlock(&xt[af].mutex);
          return ret;
  }
  EXPORT_SYMBOL(xt_register_target);
  
  void
  xt_unregister_target(struct xt_target *target)
  {
          u_int8_t af = target->family;
  
          mutex_lock(&xt[af].mutex);
          list_del(&target->list);
          mutex_unlock(&xt[af].mutex);
  }
  EXPORT_SYMBOL(xt_unregister_target);
  
  int
  xt_register_targets(struct xt_target *target, unsigned int n)
  {
          unsigned int i;
         int err = 0;
 
         for (i = 0; i < n; i++) {
                 err = xt_register_target(&target[i]);
                 if (err)
                         goto err;
         }
         return err;
 
 err:
         if (i > 0)
                 xt_unregister_targets(target, i);
         return err;
 }
 EXPORT_SYMBOL(xt_register_targets);
 
 void
 xt_unregister_targets(struct xt_target *target, unsigned int n)
 {
         unsigned int i;
 
         for (i = 0; i < n; i++)
                 xt_unregister_target(&target[i]);
 }
 EXPORT_SYMBOL(xt_unregister_targets);
 
 int
 xt_register_match(struct xt_match *match)
 {
         u_int8_t af = match->family;
         int ret;
 
         ret = mutex_lock_interruptible(&xt[af].mutex);
         if (ret != 0)
                 return ret;
 
         list_add(&match->list, &xt[af].match);
         mutex_unlock(&xt[af].mutex);
 
         return ret;
 }
 EXPORT_SYMBOL(xt_register_match);
 
 void
 xt_unregister_match(struct xt_match *match)
 {
         u_int8_t af = match->family;
 
         mutex_lock(&xt[af].mutex);
         list_del(&match->list);
         mutex_unlock(&xt[af].mutex);
 }
 EXPORT_SYMBOL(xt_unregister_match);
 
 int
 xt_register_matches(struct xt_match *match, unsigned int n)
 {
         unsigned int i;
         int err = 0;
 
         for (i = 0; i < n; i++) {
                 err = xt_register_match(&match[i]);
                 if (err)
                         goto err;
         }
         return err;
 
 err:
         if (i > 0)
                 xt_unregister_matches(match, i);
         return err;
 }
 EXPORT_SYMBOL(xt_register_matches);
 
 void
 xt_unregister_matches(struct xt_match *match, unsigned int n)
 {
         unsigned int i;
 
         for (i = 0; i < n; i++)
                 xt_unregister_match(&match[i]);
 }
 EXPORT_SYMBOL(xt_unregister_matches);
 
 
 /*
  * These are weird, but module loading must not be done with mutex
  * held (since they will register), and we have to have a single
  * function to use try_then_request_module().
  */
 
 /* Find match, grabs ref.  Returns ERR_PTR() on error. */
 struct xt_match *xt_find_match(u8 af, const char *name, u8 revision)
 {
         struct xt_match *m;
         int err = 0;
 
         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
                 return ERR_PTR(-EINTR);
 
         list_for_each_entry(m, &xt[af].match, list) {
                 if (strcmp(m->name, name) == 0) {
                         if (m->revision == revision) {
                                 if (try_module_get(m->me)) {
                                         mutex_unlock(&xt[af].mutex);
                                         return m;
                                 }
                         } else
                                 err = -EPROTOTYPE; /* Found something. */
                 }
         }
         mutex_unlock(&xt[af].mutex);
 
         if (af != NFPROTO_UNSPEC)
                 /* Try searching again in the family-independent list */
                 return xt_find_match(NFPROTO_UNSPEC, name, revision);
 
         return ERR_PTR(err);
 }
 EXPORT_SYMBOL(xt_find_match);
 
 /* Find target, grabs ref.  Returns ERR_PTR() on error. */
 struct xt_target *xt_find_target(u8 af, const char *name, u8 revision)
 {
         struct xt_target *t;
         int err = 0;
 
         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
                 return ERR_PTR(-EINTR);
 
         list_for_each_entry(t, &xt[af].target, list) {
                 if (strcmp(t->name, name) == 0) {
                         if (t->revision == revision) {
                                 if (try_module_get(t->me)) {
                                         mutex_unlock(&xt[af].mutex);
                                         return t;
                                 }
                         } else
                                 err = -EPROTOTYPE; /* Found something. */
                 }
         }
         mutex_unlock(&xt[af].mutex);
 
         if (af != NFPROTO_UNSPEC)
                 /* Try searching again in the family-independent list */
                 return xt_find_target(NFPROTO_UNSPEC, name, revision);
 
         return ERR_PTR(err);
 }
 EXPORT_SYMBOL(xt_find_target);
 
 struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision)
 {
         struct xt_target *target;
 
         target = try_then_request_module(xt_find_target(af, name, revision),
                                          "%st_%s", xt_prefix[af], name);
         if (IS_ERR(target) || !target)
                 return NULL;
         return target;
 }
 EXPORT_SYMBOL_GPL(xt_request_find_target);
 
 static int match_revfn(u8 af, const char *name, u8 revision, int *bestp)
 {
         const struct xt_match *m;
         int have_rev = 0;
 
         list_for_each_entry(m, &xt[af].match, list) {
                 if (strcmp(m->name, name) == 0) {
                         if (m->revision > *bestp)
                                 *bestp = m->revision;
                         if (m->revision == revision)
                                 have_rev = 1;
                 }
         }
         return have_rev;
 }
 
 static int target_revfn(u8 af, const char *name, u8 revision, int *bestp)
 {
         const struct xt_target *t;
         int have_rev = 0;
 
         list_for_each_entry(t, &xt[af].target, list) {
                 if (strcmp(t->name, name) == 0) {
                         if (t->revision > *bestp)
                                 *bestp = t->revision;
                         if (t->revision == revision)
                                 have_rev = 1;
                 }
         }
         return have_rev;
 }
 
 /* Returns true or false (if no such extension at all) */
 int xt_find_revision(u8 af, const char *name, u8 revision, int target,
                      int *err)
 {
         int have_rev, best = -1;
 
         if (mutex_lock_interruptible(&xt[af].mutex) != 0) {
                 *err = -EINTR;
                 return 1;
         }
         if (target == 1)
                 have_rev = target_revfn(af, name, revision, &best);
         else
                 have_rev = match_revfn(af, name, revision, &best);
         mutex_unlock(&xt[af].mutex);
 
         /* Nothing at all?  Return 0 to try loading module. */
         if (best == -1) {
                 *err = -ENOENT;
                 return 0;
         }
 
         *err = best;
         if (!have_rev)
                 *err = -EPROTONOSUPPORT;
         return 1;
 }
 EXPORT_SYMBOL_GPL(xt_find_revision);
 
 int xt_check_match(struct xt_mtchk_param *par,
                    unsigned int size, u_int8_t proto, bool inv_proto)
 {
         if (XT_ALIGN(par->match->matchsize) != size &&
             par->match->matchsize != -1) {
                 /*
                  * ebt_among is exempt from centralized matchsize checking
                  * because it uses a dynamic-size data set.
                  */
                 printk("%s_tables: %s match: invalid size %Zu != %u\n",
                        xt_prefix[par->family], par->match->name,
                        XT_ALIGN(par->match->matchsize), size);
                 return -EINVAL;
         }
         if (par->match->table != NULL &&
             strcmp(par->match->table, par->table) != 0) {
                 printk("%s_tables: %s match: only valid in %s table, not %s\n",
                        xt_prefix[par->family], par->match->name,
                        par->match->table, par->table);
                 return -EINVAL;
         }
         if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) {
                 printk("%s_tables: %s match: bad hook_mask %#x/%#x\n",
                        xt_prefix[par->family], par->match->name,
                        par->hook_mask, par->match->hooks);
                 return -EINVAL;
         }
         if (par->match->proto && (par->match->proto != proto || inv_proto)) {
                 printk("%s_tables: %s match: only valid for protocol %u\n",
                        xt_prefix[par->family], par->match->name,
                        par->match->proto);
                 return -EINVAL;
         }
         if (par->match->checkentry != NULL && !par->match->checkentry(par))
                 return -EINVAL;
         return 0;
 }
 EXPORT_SYMBOL_GPL(xt_check_match);
 
 #ifdef CONFIG_COMPAT
 int xt_compat_add_offset(u_int8_t af, unsigned int offset, short delta)
 {
         struct compat_delta *tmp;
 
         tmp = kmalloc(sizeof(struct compat_delta), GFP_KERNEL);
         if (!tmp)
                 return -ENOMEM;
 
         tmp->offset = offset;
         tmp->delta = delta;
 
         if (xt[af].compat_offsets) {
                 tmp->next = xt[af].compat_offsets->next;
                 xt[af].compat_offsets->next = tmp;
         } else {
                 xt[af].compat_offsets = tmp;
                 tmp->next = NULL;
         }
         return 0;
 }
 EXPORT_SYMBOL_GPL(xt_compat_add_offset);
 
 void xt_compat_flush_offsets(u_int8_t af)
 {
         struct compat_delta *tmp, *next;
 
         if (xt[af].compat_offsets) {
                 for (tmp = xt[af].compat_offsets; tmp; tmp = next) {
                         next = tmp->next;
                         kfree(tmp);
                 }
                 xt[af].compat_offsets = NULL;
         }
 }
 EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
 
 short xt_compat_calc_jump(u_int8_t af, unsigned int offset)
 {
         struct compat_delta *tmp;
         short delta;
 
         for (tmp = xt[af].compat_offsets, delta = 0; tmp; tmp = tmp->next)
                 if (tmp->offset < offset)
                         delta += tmp->delta;
         return delta;
 }
 EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
 
 int xt_compat_match_offset(const struct xt_match *match)
 {
         u_int16_t csize = match->compatsize ? : match->matchsize;
         return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
 }
 EXPORT_SYMBOL_GPL(xt_compat_match_offset);
 
 int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
                               unsigned int *size)
 {
         const struct xt_match *match = m->u.kernel.match;
         struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
         int pad, off = xt_compat_match_offset(match);
         u_int16_t msize = cm->u.user.match_size;
 
         m = *dstptr;
         memcpy(m, cm, sizeof(*cm));
         if (match->compat_from_user)
                 match->compat_from_user(m->data, cm->data);
         else
                 memcpy(m->data, cm->data, msize - sizeof(*cm));
         pad = XT_ALIGN(match->matchsize) - match->matchsize;
         if (pad > 0)
                 memset(m->data + match->matchsize, 0, pad);
 
         msize += off;
         m->u.user.match_size = msize;
 
         *size += off;
         *dstptr += msize;
         return 0;
 }
 EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
 
 int xt_compat_match_to_user(struct xt_entry_match *m, void __user **dstptr,
                             unsigned int *size)
 {
         const struct xt_match *match = m->u.kernel.match;
         struct compat_xt_entry_match __user *cm = *dstptr;
         int off = xt_compat_match_offset(match);
         u_int16_t msize = m->u.user.match_size - off;
 
         if (copy_to_user(cm, m, sizeof(*cm)) ||
             put_user(msize, &cm->u.user.match_size) ||
             copy_to_user(cm->u.user.name, m->u.kernel.match->name,
                          strlen(m->u.kernel.match->name) + 1))
                 return -EFAULT;
 
         if (match->compat_to_user) {
                 if (match->compat_to_user((void __user *)cm->data, m->data))
                         return -EFAULT;
         } else {
                 if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
                         return -EFAULT;
         }
 
         *size -= off;
         *dstptr += msize;
         return 0;
 }
 EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
 #endif /* CONFIG_COMPAT */
 
 int xt_check_target(struct xt_tgchk_param *par,
                     unsigned int size, u_int8_t proto, bool inv_proto)
 {
         if (XT_ALIGN(par->target->targetsize) != size) {
                 printk("%s_tables: %s target: invalid size %Zu != %u\n",
                        xt_prefix[par->family], par->target->name,
                        XT_ALIGN(par->target->targetsize), size);
                 return -EINVAL;
         }
         if (par->target->table != NULL &&
             strcmp(par->target->table, par->table) != 0) {
                 printk("%s_tables: %s target: only valid in %s table, not %s\n",
                        xt_prefix[par->family], par->target->name,
                        par->target->table, par->table);
                 return -EINVAL;
         }
         if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) {
                 printk("%s_tables: %s target: bad hook_mask %#x/%#x\n",
                        xt_prefix[par->family], par->target->name,
                        par->hook_mask, par->target->hooks);
                 return -EINVAL;
         }
         if (par->target->proto && (par->target->proto != proto || inv_proto)) {
                 printk("%s_tables: %s target: only valid for protocol %u\n",
                        xt_prefix[par->family], par->target->name,
                        par->target->proto);
                 return -EINVAL;
         }
         if (par->target->checkentry != NULL && !par->target->checkentry(par))
                 return -EINVAL;
         return 0;
 }
 EXPORT_SYMBOL_GPL(xt_check_target);
 
 #ifdef CONFIG_COMPAT
 int xt_compat_target_offset(const struct xt_target *target)
 {
         u_int16_t csize = target->compatsize ? : target->targetsize;
         return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
 }
 EXPORT_SYMBOL_GPL(xt_compat_target_offset);
 
 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
                                 unsigned int *size)
 {
         const struct xt_target *target = t->u.kernel.target;
         struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
         int pad, off = xt_compat_target_offset(target);
         u_int16_t tsize = ct->u.user.target_size;
 
         t = *dstptr;
         memcpy(t, ct, sizeof(*ct));
         if (target->compat_from_user)
                 target->compat_from_user(t->data, ct->data);
         else
                 memcpy(t->data, ct->data, tsize - sizeof(*ct));
         pad = XT_ALIGN(target->targetsize) - target->targetsize;
         if (pad > 0)
                 memset(t->data + target->targetsize, 0, pad);
 
         tsize += off;
         t->u.user.target_size = tsize;
 
         *size += off;
         *dstptr += tsize;
 }
 EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
 
 int xt_compat_target_to_user(struct xt_entry_target *t, void __user **dstptr,
                              unsigned int *size)
 {
         const struct xt_target *target = t->u.kernel.target;
         struct compat_xt_entry_target __user *ct = *dstptr;
         int off = xt_compat_target_offset(target);
         u_int16_t tsize = t->u.user.target_size - off;
 
         if (copy_to_user(ct, t, sizeof(*ct)) ||
             put_user(tsize, &ct->u.user.target_size) ||
             copy_to_user(ct->u.user.name, t->u.kernel.target->name,
                          strlen(t->u.kernel.target->name) + 1))
                 return -EFAULT;
 
         if (target->compat_to_user) {
                 if (target->compat_to_user((void __user *)ct->data, t->data))
                         return -EFAULT;
         } else {
                 if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
                         return -EFAULT;
         }
 
         *size -= off;
         *dstptr += tsize;
         return 0;
 }
 EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
 #endif
 
 struct xt_table_info *xt_alloc_table_info(unsigned int size)
 {
         struct xt_table_info *newinfo;
         int cpu;
 
         /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
         if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
                 return NULL;
 
         newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
         if (!newinfo)
                 return NULL;
 
         newinfo->size = size;
 
         for_each_possible_cpu(cpu) {
                 if (size <= PAGE_SIZE)
                         newinfo->entries[cpu] = kmalloc_node(size,
                                                         GFP_KERNEL,
                                                         cpu_to_node(cpu));
                 else
                         newinfo->entries[cpu] = vmalloc_node(size,
                                                         cpu_to_node(cpu));
 
                 if (newinfo->entries[cpu] == NULL) {
                         xt_free_table_info(newinfo);
                         return NULL;
                 }
         }
 
         return newinfo;
 }
 EXPORT_SYMBOL(xt_alloc_table_info);
 
 void xt_free_table_info(struct xt_table_info *info)
 {
         int cpu;
 
         for_each_possible_cpu(cpu) {
                 if (info->size <= PAGE_SIZE)
                         kfree(info->entries[cpu]);
                 else
                         vfree(info->entries[cpu]);
         }
         kfree(info);
 }
 EXPORT_SYMBOL(xt_free_table_info);
 
 /* Find table by name, grabs mutex & ref.  Returns ERR_PTR() on error. */
 struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
                                     const char *name)
 {
         struct xt_table *t;
 
         if (mutex_lock_interruptible(&xt[af].mutex) != 0)
                 return ERR_PTR(-EINTR);
 
         list_for_each_entry(t, &net->xt.tables[af], list)
                 if (strcmp(t->name, name) == 0 && try_module_get(t->me))
                         return t;
         mutex_unlock(&xt[af].mutex);
         return NULL;
 }
 EXPORT_SYMBOL_GPL(xt_find_table_lock);
 
 void xt_table_unlock(struct xt_table *table)
 {
         mutex_unlock(&xt[table->af].mutex);
 }
 EXPORT_SYMBOL_GPL(xt_table_unlock);
 
 #ifdef CONFIG_COMPAT
 void xt_compat_lock(u_int8_t af)
 {
         mutex_lock(&xt[af].compat_mutex);
 }
 EXPORT_SYMBOL_GPL(xt_compat_lock);
 
 void xt_compat_unlock(u_int8_t af)
 {
         mutex_unlock(&xt[af].compat_mutex);
 }
 EXPORT_SYMBOL_GPL(xt_compat_unlock);
 #endif
 
 struct xt_table_info *
 xt_replace_table(struct xt_table *table,
               unsigned int num_counters,
               struct xt_table_info *newinfo,
               int *error)
 {
         struct xt_table_info *oldinfo, *private;
 
         /* Do the substitution. */
         write_lock_bh(&table->lock);
         private = table->private;
         /* Check inside lock: is the old number correct? */
         if (num_counters != private->number) {
                 duprintf("num_counters != table->private->number (%u/%u)\n",
                          num_counters, private->number);
                 write_unlock_bh(&table->lock);
                 *error = -EAGAIN;
                 return NULL;
         }
         oldinfo = private;
         table->private = newinfo;
         newinfo->initial_entries = oldinfo->initial_entries;
         write_unlock_bh(&table->lock);
 
         return oldinfo;
 }
 EXPORT_SYMBOL_GPL(xt_replace_table);
 
 struct xt_table *xt_register_table(struct net *net, struct xt_table *table,
                                    struct xt_table_info *bootstrap,
                                    struct xt_table_info *newinfo)
 {
         int ret;
         struct xt_table_info *private;
         struct xt_table *t;
 
         /* Don't add one object to multiple lists. */
         table = kmemdup(table, sizeof(struct xt_table), GFP_KERNEL);
         if (!table) {
                 ret = -ENOMEM;
                 goto out;
         }
 
         ret = mutex_lock_interruptible(&xt[table->af].mutex);
         if (ret != 0)
                 goto out_free;
 
         /* Don't autoload: we'd eat our tail... */
         list_for_each_entry(t, &net->xt.tables[table->af], list) {
                 if (strcmp(t->name, table->name) == 0) {
                         ret = -EEXIST;
                         goto unlock;
                 }
         }
 
         /* Simplifies replace_table code. */
         table->private = bootstrap;
         rwlock_init(&table->lock);
         if (!xt_replace_table(table, 0, newinfo, &ret))
                 goto unlock;
 
         private = table->private;
         duprintf("table->private->number = %u\n", private->number);
 
         /* save number of initial entries */
         private->initial_entries = private->number;
 
         list_add(&table->list, &net->xt.tables[table->af]);
         mutex_unlock(&xt[table->af].mutex);
         return table;
 
  unlock:
         mutex_unlock(&xt[table->af].mutex);
 out_free:
         kfree(table);
 out:
         return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(xt_register_table);
 
 void *xt_unregister_table(struct xt_table *table)
 {
         struct xt_table_info *private;
 
         mutex_lock(&xt[table->af].mutex);
         private = table->private;
         list_del(&table->list);
         mutex_unlock(&xt[table->af].mutex);
         kfree(table);
 
         return private;
 }
 EXPORT_SYMBOL_GPL(xt_unregister_table);
 
 #ifdef CONFIG_PROC_FS
 struct xt_names_priv {
         struct seq_net_private p;
         u_int8_t af;
 };
 static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
 {
         struct xt_names_priv *priv = seq->private;
         struct net *net = seq_file_net(seq);
         u_int8_t af = priv->af;
 
         mutex_lock(&xt[af].mutex);
         return seq_list_start(&net->xt.tables[af], *pos);
 }
 
 static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
         struct xt_names_priv *priv = seq->private;
         struct net *net = seq_file_net(seq);
         u_int8_t af = priv->af;
 
         return seq_list_next(v, &net->xt.tables[af], pos);
 }
 
 static void xt_table_seq_stop(struct seq_file *seq, void *v)
 {
         struct xt_names_priv *priv = seq->private;
         u_int8_t af = priv->af;
 
         mutex_unlock(&xt[af].mutex);
 }
 
 static int xt_table_seq_show(struct seq_file *seq, void *v)
 {
         struct xt_table *table = list_entry(v, struct xt_table, list);
 
         if (strlen(table->name))
                 return seq_printf(seq, "%s\n", table->name);
         else
                 return 0;
 }
 
 static const struct seq_operations xt_table_seq_ops = {
         .start        = xt_table_seq_start,
         .next        = xt_table_seq_next,
         .stop        = xt_table_seq_stop,
         .show        = xt_table_seq_show,
 };
 
 static int xt_table_open(struct inode *inode, struct file *file)
 {
         int ret;
         struct xt_names_priv *priv;
 
         ret = seq_open_net(inode, file, &xt_table_seq_ops,
                            sizeof(struct xt_names_priv));
         if (!ret) {
                 priv = ((struct seq_file *)file->private_data)->private;
                 priv->af = (unsigned long)PDE(inode)->data;
         }
         return ret;
 }
 
 static const struct file_operations xt_table_ops = {
         .owner         = THIS_MODULE,
         .open         = xt_table_open,
         .read         = seq_read,
         .llseek         = seq_lseek,
         .release = seq_release_net,
 };
 
 static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
 {
         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
         u_int16_t af = (unsigned long)pde->data;
 
         mutex_lock(&xt[af].mutex);
         return seq_list_start(&xt[af].match, *pos);
 }
 
 static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
         u_int16_t af = (unsigned long)pde->data;
 
         return seq_list_next(v, &xt[af].match, pos);
 }
 
 static void xt_match_seq_stop(struct seq_file *seq, void *v)
 {
         struct proc_dir_entry *pde = seq->private;
         u_int16_t af = (unsigned long)pde->data;
 
         mutex_unlock(&xt[af].mutex);
 }
 
 static int xt_match_seq_show(struct seq_file *seq, void *v)
 {
         struct xt_match *match = list_entry(v, struct xt_match, list);
 
         if (strlen(match->name))
                 return seq_printf(seq, "%s\n", match->name);
         else
                 return 0;
 }
 
 static const struct seq_operations xt_match_seq_ops = {
         .start        = xt_match_seq_start,
         .next        = xt_match_seq_next,
         .stop        = xt_match_seq_stop,
         .show        = xt_match_seq_show,
 };
 
 static int xt_match_open(struct inode *inode, struct file *file)
 {
         int ret;
 
         ret = seq_open(file, &xt_match_seq_ops);
         if (!ret) {
                 struct seq_file *seq = file->private_data;
 
                 seq->private = PDE(inode);
         }
         return ret;
 }
 
 static const struct file_operations xt_match_ops = {
         .owner         = THIS_MODULE,
         .open         = xt_match_open,
         .read         = seq_read,
         .llseek         = seq_lseek,
         .release = seq_release,
 };
 
 static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
 {
         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
         u_int16_t af = (unsigned long)pde->data;
 
         mutex_lock(&xt[af].mutex);
         return seq_list_start(&xt[af].target, *pos);
 }
 
 static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
         struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
         u_int16_t af = (unsigned long)pde->data;
 
         return seq_list_next(v, &xt[af].target, pos);
 }
 
 static void xt_target_seq_stop(struct seq_file *seq, void *v)
 {
         struct proc_dir_entry *pde = seq->private;
         u_int16_t af = (unsigned long)pde->data;
 
         mutex_unlock(&xt[af].mutex);
 }
 
 static int xt_target_seq_show(struct seq_file *seq, void *v)
 {
         struct xt_target *target = list_entry(v, struct xt_target, list);
 
         if (strlen(target->name))
                 return seq_printf(seq, "%s\n", target->name);
         else
                 return 0;
 }
 
 static const struct seq_operations xt_target_seq_ops = {
         .start        = xt_target_seq_start,
         .next        = xt_target_seq_next,
         .stop        = xt_target_seq_stop,
         .show        = xt_target_seq_show,
 };
 
 static int xt_target_open(struct inode *inode, struct file *file)
 {
         int ret;
 
         ret = seq_open(file, &xt_target_seq_ops);
         if (!ret) {
                 struct seq_file *seq = file->private_data;
 
                 seq->private = PDE(inode);
         }
         return ret;
 }
 
 static const struct file_operations xt_target_ops = {
         .owner         = THIS_MODULE,
         .open         = xt_target_open,
         .read         = seq_read,
         .llseek         = seq_lseek,
         .release = seq_release,
 };
 
 #define FORMAT_TABLES        "_tables_names"
 #define        FORMAT_MATCHES        "_tables_matches"
 #define FORMAT_TARGETS         "_tables_targets"
 
 #endif /* CONFIG_PROC_FS */
 
 int xt_proto_init(struct net *net, u_int8_t af)
 {
 #ifdef CONFIG_PROC_FS
         char buf[XT_FUNCTION_MAXNAMELEN];
         struct proc_dir_entry *proc;
 #endif
 
         if (af >= ARRAY_SIZE(xt_prefix))
                 return -EINVAL;
 
 
 #ifdef CONFIG_PROC_FS
         strlcpy(buf, xt_prefix[af], sizeof(buf));
         strlcat(buf, FORMAT_TABLES, sizeof(buf));
         proc = proc_create_data(buf, 0440, net->proc_net, &xt_table_ops,
                                 (void *)(unsigned long)af);
         if (!proc)
                 goto out;
 
         strlcpy(buf, xt_prefix[af], sizeof(buf));
         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
         proc = proc_create_data(buf, 0440, net->proc_net, &xt_match_ops,
                                 (void *)(unsigned long)af);
         if (!proc)
                 goto out_remove_tables;
 
         strlcpy(buf, xt_prefix[af], sizeof(buf));
         strlcat(buf, FORMAT_TARGETS, sizeof(buf));
         proc = proc_create_data(buf, 0440, net->proc_net, &xt_target_ops,
                                 (void *)(unsigned long)af);
         if (!proc)
                 goto out_remove_matches;
 #endif
 
         return 0;
 
 #ifdef CONFIG_PROC_FS
 out_remove_matches:
         strlcpy(buf, xt_prefix[af], sizeof(buf));
         strlcat(buf, FORMAT_MATCHES, sizeof(buf));
         proc_net_remove(net, buf);
 
 out_remove_tables:
         strlcpy(buf, xt_prefix[af], sizeof(buf));
         strlcat(buf, FORMAT_TABLES, sizeof(buf));
         proc_net_remove(net, buf);
out:
        return -1;
#endif
}
EXPORT_SYMBOL_GPL(xt_proto_init);

void xt_proto_fini(struct net *net, u_int8_t af)
{
#ifdef CONFIG_PROC_FS
        char buf[XT_FUNCTION_MAXNAMELEN];

        strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_TABLES, sizeof(buf));
        proc_net_remove(net, buf);

        strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_TARGETS, sizeof(buf));
        proc_net_remove(net, buf);

        strlcpy(buf, xt_prefix[af], sizeof(buf));
        strlcat(buf, FORMAT_MATCHES, sizeof(buf));
        proc_net_remove(net, buf);
#endif /*CONFIG_PROC_FS*/
}
EXPORT_SYMBOL_GPL(xt_proto_fini);

static int __net_init xt_net_init(struct net *net)
{
        int i;

        for (i = 0; i < NFPROTO_NUMPROTO; i++)
                INIT_LIST_HEAD(&net->xt.tables[i]);
        return 0;
}

static struct pernet_operations xt_net_ops = {
        .init = xt_net_init,
};

static int __init xt_init(void)
{
        int i, rv;

        xt = kmalloc(sizeof(struct xt_af) * NFPROTO_NUMPROTO, GFP_KERNEL);
        if (!xt)
                return -ENOMEM;

        for (i = 0; i < NFPROTO_NUMPROTO; i++) {
                mutex_init(&xt[i].mutex);
#ifdef CONFIG_COMPAT
                mutex_init(&xt[i].compat_mutex);
                xt[i].compat_offsets = NULL;
#endif
                INIT_LIST_HEAD(&xt[i].target);
                INIT_LIST_HEAD(&xt[i].match);
        }
        rv = register_pernet_subsys(&xt_net_ops);
        if (rv < 0)
                kfree(xt);
        return rv;
}

static void __exit xt_fini(void)
{
        unregister_pernet_subsys(&xt_net_ops);
        kfree(xt);
}

module_init(xt_init);
module_exit(xt_fini);