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