security/tomoyo/path_group.c

   1 /*
   2  * security/tomoyo/path_group.c
   3  *
   4  * Copyright (C) 2005-2009  NTT DATA CORPORATION
   5  */
   6
   7 #include <linux/slab.h>
   8 #include "common.h"
   9 /* The list for "struct tomoyo_path_group". */
  10 LIST_HEAD(tomoyo_path_group_list);
  11
  12 /**
  13  * tomoyo_get_path_group - Allocate memory for "struct tomoyo_path_group".
  14  *
  15  * @group_name: The name of pathname group.
  16  *
  17  * Returns pointer to "struct tomoyo_path_group" on success, NULL otherwise.
  18  */
  19 struct tomoyo_path_group *tomoyo_get_path_group(const char *group_name)
  20 {
  21         struct tomoyo_path_group *entry = NULL;
  22         struct tomoyo_path_group *group = NULL;
  23         const struct tomoyo_path_info *saved_group_name;
  24         int error = -ENOMEM;
  25         if (!tomoyo_is_correct_path(group_name, 0, 0, 0) ||
  26             !group_name[0])
  27                 return NULL;
  28         saved_group_name = tomoyo_get_name(group_name);
  29         if (!saved_group_name)
  30                 return NULL;
  31         entry = kzalloc(sizeof(*entry), GFP_NOFS);
  32         if (mutex_lock_interruptible(&tomoyo_policy_lock))
  33                 goto out;
  34         list_for_each_entry_rcu(group, &tomoyo_path_group_list, list) {
  35                 if (saved_group_name != group->group_name)
  36                         continue;
  37                 atomic_inc(&group->users);
  38                 error = 0;
  39                 break;
  40         }
  41         if (error && tomoyo_memory_ok(entry)) {
  42                 INIT_LIST_HEAD(&entry->member_list);
  43                 entry->group_name = saved_group_name;
  44                 saved_group_name = NULL;
  45                 atomic_set(&entry->users, 1);
  46                 list_add_tail_rcu(&entry->list, &tomoyo_path_group_list);
  47                 group = entry;
  48                 entry = NULL;
  49                 error = 0;
  50         }
  51         mutex_unlock(&tomoyo_policy_lock);
  52  out:
  53         tomoyo_put_name(saved_group_name);
  54         kfree(entry);
  55         return !error ? group : NULL;
  56 }
  57
  58 /**
  59  * tomoyo_write_path_group_policy - Write "struct tomoyo_path_group" list.
  60  *
  61  * @data:      String to parse.
  62  * @is_delete: True if it is a delete request.
  63  *
  64  * Returns 0 on success, nagative value otherwise.
  65  */
  66 int tomoyo_write_path_group_policy(char *data, const bool is_delete)
  67 {
  68         struct tomoyo_path_group *group;
  69         struct tomoyo_path_group_member *member;
  70         struct tomoyo_path_group_member e = { };
  71         int error = is_delete ? -ENOENT : -ENOMEM;
  72         char *w[2];
  73         if (!tomoyo_tokenize(data, w, sizeof(w)) || !w[1][0])
  74                 return -EINVAL;
  75         group = tomoyo_get_path_group(w[0]);
  76         if (!group)
  77                 return -ENOMEM;
  78         e.member_name = tomoyo_get_name(w[1]);
  79         if (!e.member_name)
  80                 goto out;
  81         if (mutex_lock_interruptible(&tomoyo_policy_lock))
  82                 goto out;
  83         list_for_each_entry_rcu(member, &group->member_list, list) {
  84                 if (member->member_name != e.member_name)
  85                         continue;
  86                 member->is_deleted = is_delete;
  87                 error = 0;
  88                 break;
  89         }
  90         if (!is_delete && error) {
  91                 struct tomoyo_path_group_member *entry =
  92                         tomoyo_commit_ok(&e, sizeof(e));
  93                 if (entry) {
  94                         list_add_tail_rcu(&entry->list, &group->member_list);
  95                         error = 0;
  96                 }
  97         }
  98         mutex_unlock(&tomoyo_policy_lock);
  99  out:
 100         tomoyo_put_name(e.member_name);
 101         tomoyo_put_path_group(group);
 102         return error;
 103 }
 104
 105 /**
 106  * tomoyo_read_path_group_policy - Read "struct tomoyo_path_group" list.
 107  *
 108  * @head: Pointer to "struct tomoyo_io_buffer".
 109  *
 110  * Returns true on success, false otherwise.
 111  *
 112  * Caller holds tomoyo_read_lock().
 113  */
 114 bool tomoyo_read_path_group_policy(struct tomoyo_io_buffer *head)
 115 {
 116         struct list_head *gpos;
 117         struct list_head *mpos;
 118         list_for_each_cookie(gpos, head->read_var1, &tomoyo_path_group_list) {
 119                 struct tomoyo_path_group *group;
 120                 group = list_entry(gpos, struct tomoyo_path_group, list);
 121                 list_for_each_cookie(mpos, head->read_var2,
 122                                      &group->member_list) {
 123                         struct tomoyo_path_group_member *member;
 124                         member = list_entry(mpos,
 125                                             struct tomoyo_path_group_member,
 126                                             list);
 127                         if (member->is_deleted)
 128                                 continue;
 129                         if (!tomoyo_io_printf(head, TOMOYO_KEYWORD_PATH_GROUP
 130                                               "%s %s\n",
 131                                               group->group_name->name,
 132                                               member->member_name->name))
 133                                 return false;
 134                 }
 135         }
 136         return true;
 137 }
 138
 139 /**
 140  * tomoyo_path_matches_group - Check whether the given pathname matches members of the given pathname group.
 141  *
 142  * @pathname:        The name of pathname.
 143  * @group:           Pointer to "struct tomoyo_path_group".
 144  * @may_use_pattern: True if wild card is permitted.
 145  *
 146  * Returns true if @pathname matches pathnames in @group, false otherwise.
 147  *
 148  * Caller holds tomoyo_read_lock().
 149  */
 150 bool tomoyo_path_matches_group(const struct tomoyo_path_info *pathname,
 151                                const struct tomoyo_path_group *group,
 152                                const bool may_use_pattern)
 153 {
 154         struct tomoyo_path_group_member *member;
 155         bool matched = false;
 156         list_for_each_entry_rcu(member, &group->member_list, list) {
 157                 if (member->is_deleted)
 158                         continue;
 159                 if (!member->member_name->is_patterned) {
 160                         if (tomoyo_pathcmp(pathname, member->member_name))
 161                                 continue;
 162                 } else if (may_use_pattern) {
 163                         if (!tomoyo_path_matches_pattern(pathname,
 164                                                          member->member_name))
 165                                 continue;
 166                 } else
 167                         continue;
 168                 matched = true;
 169                 break;
 170         }
 171         return matched;
 172 }