TOMOYO: Use callback for updating entries.
[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 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 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_member, head)
61                 ->member_name ==
62                 container_of(b, struct tomoyo_path_group_member, 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_path_group *group;
77         struct tomoyo_path_group_member 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_path_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_path_group *group;
112                 group = list_entry(gpos, struct tomoyo_path_group, list);
113                 list_for_each_cookie(mpos, head->read_var2,
114                                      &group->member_list) {
115                         struct tomoyo_path_group_member *member;
116                         member = list_entry(mpos,
117                                             struct tomoyo_path_group_member,
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_path_group *group)
143 {
144         struct tomoyo_path_group_member *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 }