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_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_group *tomoyo_get_path_group(const char *group_name)
  20 {
  21         struct tomoyo_group *entry = NULL;
  22         struct tomoyo_group *group = NULL;
  23         const struct tomoyo_path_info *saved_group_name;
  24         int error = -ENOMEM;
  25         if (!tomoyo_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 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_read_path_group_policy - Read "struct tomoyo_path_group" list.
  99  *
 100  * @head: Pointer to "struct tomoyo_io_buffer".
 101  *
 102  * Returns true on success, false otherwise.
 103  *
 104  * Caller holds tomoyo_read_lock().
 105  */
 106 bool tomoyo_read_path_group_policy(struct tomoyo_io_buffer *head)
 107 {
 108         struct list_head *gpos;
 109         struct list_head *mpos;
 110         list_for_each_cookie(gpos, head->read_var1, &tomoyo_path_group_list) {
 111                 struct tomoyo_group *group;
 112                 group = list_entry(gpos, struct tomoyo_group, list);
 113                 list_for_each_cookie(mpos, head->read_var2,
 114                                      &group->member_list) {
 115                         struct tomoyo_path_group *member;
 116                         member = list_entry(mpos,
 117                                             struct tomoyo_path_group,
 118                                             head.list);
 119                         if (member->head.is_deleted)
 120                                 continue;
 121                         if (!tomoyo_io_printf(head, TOMOYO_KEYWORD_PATH_GROUP
 122                                               "%s %s\n",
 123                                               group->group_name->name,
 124                                               member->member_name->name))
 125                                 return false;
 126                 }
 127         }
 128         return true;
 129 }
 130
 131 /**
 132  * tomoyo_path_matches_group - Check whether the given pathname matches members of the given pathname group.
 133  *
 134  * @pathname:        The name of pathname.
 135  * @group:           Pointer to "struct tomoyo_path_group".
 136  *
 137  * Returns true if @pathname matches pathnames in @group, false otherwise.
 138  *
 139  * Caller holds tomoyo_read_lock().
 140  */
 141 bool tomoyo_path_matches_group(const struct tomoyo_path_info *pathname,
 142                                const struct tomoyo_group *group)
 143 {
 144         struct tomoyo_path_group *member;
 145         bool matched = false;
 146         list_for_each_entry_rcu(member, &group->member_list, head.list) {
 147                 if (member->head.is_deleted)
 148                         continue;
 149                 if (!tomoyo_path_matches_pattern(pathname,
 150                                                  member->member_name))
 151                         continue;
 152                 matched = true;
 153                 break;
 154         }
 155         return matched;
 156 }