c988041c8e1c2e59e7f81cb296283dd0dfe5d393
[linux-2.6.git] / 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 ccs_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 }