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
  10 /**
  11  * tomoyo_get_group - Allocate memory for "struct tomoyo_path_group".
  12  *
  13  * @group_name: The name of pathname group.
  14  *
  15  * Returns pointer to "struct tomoyo_path_group" on success, NULL otherwise.
  16  */
  17 struct tomoyo_group *tomoyo_get_path_group(const char *group_name)
  18 {
  19         struct tomoyo_group *entry = NULL;
  20         struct tomoyo_group *group = NULL;
  21         const struct tomoyo_path_info *saved_group_name;
  22         int error = -ENOMEM;
  23         if (!tomoyo_correct_word(group_name))
  24                 return NULL;
  25         saved_group_name = tomoyo_get_name(group_name);
  26         if (!saved_group_name)
  27                 return NULL;
  28         entry = kzalloc(sizeof(*entry), GFP_NOFS);
  29         if (mutex_lock_interruptible(&tomoyo_policy_lock))
  30                 goto out;
  31         list_for_each_entry_rcu(group, &tomoyo_group_list[TOMOYO_PATH_GROUP],
  32                                 list) {
  33                 if (saved_group_name != group->group_name)
  34                         continue;
  35                 atomic_inc(&group->users);
  36                 error = 0;
  37                 break;
  38         }
  39         if (error && tomoyo_memory_ok(entry)) {
  40                 INIT_LIST_HEAD(&entry->member_list);
  41                 entry->group_name = saved_group_name;
  42                 saved_group_name = NULL;
  43                 atomic_set(&entry->users, 1);
  44                 list_add_tail_rcu(&entry->list,
  45                                   &tomoyo_group_list[TOMOYO_PATH_GROUP]);
  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 static bool tomoyo_same_path_group(const struct tomoyo_acl_head *a,
  58                                    const struct tomoyo_acl_head *b)
  59 {
  60         return container_of(a, struct tomoyo_path_group, head)
  61                 ->member_name ==
  62                 container_of(b, struct tomoyo_path_group, head)
  63                 ->member_name;
  64 }
  65
  66 /**
  67  * tomoyo_write_path_group_policy - Write "struct tomoyo_path_group" list.
  68  *
  69  * @data:      String to parse.
  70  * @is_delete: True if it is a delete request.
  71  *
  72  * Returns 0 on success, nagative value otherwise.
  73  */
  74 int tomoyo_write_path_group_policy(char *data, const bool is_delete)
  75 {
  76         struct tomoyo_group *group;
  77         struct tomoyo_path_group e = { };
  78         int error = is_delete ? -ENOENT : -ENOMEM;
  79         char *w[2];
  80         if (!tomoyo_tokenize(data, w, sizeof(w)) || !w[1][0])
  81                 return -EINVAL;
  82         group = tomoyo_get_path_group(w[0]);
  83         if (!group)
  84                 return -ENOMEM;
  85         e.member_name = tomoyo_get_name(w[1]);
  86         if (!e.member_name)
  87                 goto out;
  88         error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
  89                                      &group->member_list,
  90                                      tomoyo_same_path_group);
  91  out:
  92         tomoyo_put_name(e.member_name);
  93         tomoyo_put_group(group);
  94         return error;
  95 }
  96
  97 /**
  98  * tomoyo_path_matches_group - Check whether the given pathname matches members of the given pathname group.
  99  *
 100  * @pathname:        The name of pathname.
 101  * @group:           Pointer to "struct tomoyo_path_group".
 102  *
 103  * Returns true if @pathname matches pathnames in @group, false otherwise.
 104  *
 105  * Caller holds tomoyo_read_lock().
 106  */
 107 bool tomoyo_path_matches_group(const struct tomoyo_path_info *pathname,
 108                                const struct tomoyo_group *group)
 109 {
 110         struct tomoyo_path_group *member;
 111         bool matched = false;
 112         list_for_each_entry_rcu(member, &group->member_list, head.list) {
 113                 if (member->head.is_deleted)
 114                         continue;
 115                 if (!tomoyo_path_matches_pattern(pathname,
 116                                                  member->member_name))
 117                         continue;
 118                 matched = true;
 119                 break;
 120         }
 121         return matched;
 122 }