blob: 42a7b1ba8cbf221ceeaa188c2089fa2a99e01a94 [file] [log] [blame]
Tetsuo Handac3ef1502010-05-17 10:12:46 +09001/*
2 * security/tomoyo/memory.c
3 *
4 * Memory management functions for TOMOYO.
5 *
6 * Copyright (C) 2005-2010 NTT DATA CORPORATION
7 */
8
9#include <linux/hash.h>
10#include <linux/slab.h>
11#include "common.h"
12
13/**
14 * tomoyo_warn_oom - Print out of memory warning message.
15 *
16 * @function: Function's name.
17 */
18void tomoyo_warn_oom(const char *function)
19{
20 /* Reduce error messages. */
21 static pid_t tomoyo_last_pid;
22 const pid_t pid = current->pid;
23 if (tomoyo_last_pid != pid) {
24 printk(KERN_WARNING "ERROR: Out of memory at %s.\n",
25 function);
26 tomoyo_last_pid = pid;
27 }
28 if (!tomoyo_policy_loaded)
29 panic("MAC Initialization failed.\n");
30}
31
32/* Memory allocated for policy. */
33static atomic_t tomoyo_policy_memory_size;
34/* Quota for holding policy. */
35static unsigned int tomoyo_quota_for_policy;
36
37/**
38 * tomoyo_memory_ok - Check memory quota.
39 *
40 * @ptr: Pointer to allocated memory.
41 *
42 * Returns true on success, false otherwise.
43 *
44 * Returns true if @ptr is not NULL and quota not exceeded, false otherwise.
45 */
46bool tomoyo_memory_ok(void *ptr)
47{
48 size_t s = ptr ? ksize(ptr) : 0;
49 atomic_add(s, &tomoyo_policy_memory_size);
50 if (ptr && (!tomoyo_quota_for_policy ||
51 atomic_read(&tomoyo_policy_memory_size)
52 <= tomoyo_quota_for_policy)) {
53 memset(ptr, 0, s);
54 return true;
55 }
56 atomic_sub(s, &tomoyo_policy_memory_size);
57 tomoyo_warn_oom(__func__);
58 return false;
59}
60
61/**
62 * tomoyo_commit_ok - Check memory quota.
63 *
64 * @data: Data to copy from.
65 * @size: Size in byte.
66 *
67 * Returns pointer to allocated memory on success, NULL otherwise.
68 * @data is zero-cleared on success.
69 */
70void *tomoyo_commit_ok(void *data, const unsigned int size)
71{
72 void *ptr = kzalloc(size, GFP_NOFS);
73 if (tomoyo_memory_ok(ptr)) {
74 memmove(ptr, data, size);
75 memset(data, 0, size);
76 return ptr;
77 }
Xiaochen Wangcfc64fd2011-03-31 00:27:32 +090078 kfree(ptr);
Tetsuo Handac3ef1502010-05-17 10:12:46 +090079 return NULL;
80}
81
82/**
83 * tomoyo_memory_free - Free memory for elements.
84 *
85 * @ptr: Pointer to allocated memory.
86 */
87void tomoyo_memory_free(void *ptr)
88{
89 atomic_sub(ksize(ptr), &tomoyo_policy_memory_size);
90 kfree(ptr);
91}
92
Tetsuo Handa7c2ea222010-06-17 16:55:58 +090093/**
94 * tomoyo_get_group - Allocate memory for "struct tomoyo_path_group"/"struct tomoyo_number_group".
95 *
96 * @group_name: The name of address group.
97 * @idx: Index number.
98 *
99 * Returns pointer to "struct tomoyo_group" on success, NULL otherwise.
100 */
101struct tomoyo_group *tomoyo_get_group(const char *group_name, const u8 idx)
102{
103 struct tomoyo_group e = { };
104 struct tomoyo_group *group = NULL;
105 bool found = false;
106 if (!tomoyo_correct_word(group_name) || idx >= TOMOYO_MAX_GROUP)
107 return NULL;
108 e.group_name = tomoyo_get_name(group_name);
109 if (!e.group_name)
110 return NULL;
111 if (mutex_lock_interruptible(&tomoyo_policy_lock))
112 goto out;
113 list_for_each_entry(group, &tomoyo_group_list[idx], list) {
114 if (e.group_name != group->group_name)
115 continue;
116 atomic_inc(&group->users);
117 found = true;
118 break;
119 }
120 if (!found) {
121 struct tomoyo_group *entry = tomoyo_commit_ok(&e, sizeof(e));
122 if (entry) {
123 INIT_LIST_HEAD(&entry->member_list);
124 atomic_set(&entry->users, 1);
125 list_add_tail_rcu(&entry->list,
126 &tomoyo_group_list[idx]);
127 group = entry;
128 found = true;
129 }
130 }
131 mutex_unlock(&tomoyo_policy_lock);
132 out:
133 tomoyo_put_name(e.group_name);
134 return found ? group : NULL;
135}
136
Tetsuo Handac3ef1502010-05-17 10:12:46 +0900137/*
138 * tomoyo_name_list is used for holding string data used by TOMOYO.
139 * Since same string data is likely used for multiple times (e.g.
140 * "/lib/libc-2.5.so"), TOMOYO shares string data in the form of
141 * "const struct tomoyo_path_info *".
142 */
143struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];
144
145/**
146 * tomoyo_get_name - Allocate permanent memory for string data.
147 *
148 * @name: The string to store into the permernent memory.
149 *
150 * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
151 */
152const struct tomoyo_path_info *tomoyo_get_name(const char *name)
153{
Tetsuo Handae2bf6902010-06-25 11:16:00 +0900154 struct tomoyo_name *ptr;
Tetsuo Handac3ef1502010-05-17 10:12:46 +0900155 unsigned int hash;
156 int len;
157 int allocated_len;
158 struct list_head *head;
159
160 if (!name)
161 return NULL;
162 len = strlen(name) + 1;
163 hash = full_name_hash((const unsigned char *) name, len - 1);
164 head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)];
165 if (mutex_lock_interruptible(&tomoyo_policy_lock))
166 return NULL;
167 list_for_each_entry(ptr, head, list) {
168 if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name))
169 continue;
170 atomic_inc(&ptr->users);
171 goto out;
172 }
173 ptr = kzalloc(sizeof(*ptr) + len, GFP_NOFS);
174 allocated_len = ptr ? ksize(ptr) : 0;
175 if (!ptr || (tomoyo_quota_for_policy &&
176 atomic_read(&tomoyo_policy_memory_size) + allocated_len
177 > tomoyo_quota_for_policy)) {
178 kfree(ptr);
179 ptr = NULL;
180 tomoyo_warn_oom(__func__);
181 goto out;
182 }
183 atomic_add(allocated_len, &tomoyo_policy_memory_size);
184 ptr->entry.name = ((char *) ptr) + sizeof(*ptr);
185 memmove((char *) ptr->entry.name, name, len);
186 atomic_set(&ptr->users, 1);
187 tomoyo_fill_path_info(&ptr->entry);
188 list_add_tail(&ptr->list, head);
189 out:
190 mutex_unlock(&tomoyo_policy_lock);
191 return ptr ? &ptr->entry : NULL;
192}
193
194/**
195 * tomoyo_mm_init - Initialize mm related code.
196 */
197void __init tomoyo_mm_init(void)
198{
199 int idx;
200
Tetsuo Handaa230f9e2010-06-17 16:53:24 +0900201 for (idx = 0; idx < TOMOYO_MAX_POLICY; idx++)
202 INIT_LIST_HEAD(&tomoyo_policy_list[idx]);
203 for (idx = 0; idx < TOMOYO_MAX_GROUP; idx++)
204 INIT_LIST_HEAD(&tomoyo_group_list[idx]);
Tetsuo Handac3ef1502010-05-17 10:12:46 +0900205 for (idx = 0; idx < TOMOYO_MAX_HASH; idx++)
206 INIT_LIST_HEAD(&tomoyo_name_list[idx]);
207 INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list);
208 tomoyo_kernel_domain.domainname = tomoyo_get_name(TOMOYO_ROOT_NAME);
209 list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list);
210 idx = tomoyo_read_lock();
211 if (tomoyo_find_domain(TOMOYO_ROOT_NAME) != &tomoyo_kernel_domain)
212 panic("Can't register tomoyo_kernel_domain");
213 {
214 /* Load built-in policy. */
Tetsuo Handa5448ec42010-06-21 11:14:39 +0900215 tomoyo_write_transition_control("/sbin/hotplug", false,
216 TOMOYO_TRANSITION_CONTROL_INITIALIZE);
217 tomoyo_write_transition_control("/sbin/modprobe", false,
218 TOMOYO_TRANSITION_CONTROL_INITIALIZE);
Tetsuo Handac3ef1502010-05-17 10:12:46 +0900219 }
220 tomoyo_read_unlock(idx);
221}
222
223
224/* Memory allocated for query lists. */
225unsigned int tomoyo_query_memory_size;
226/* Quota for holding query lists. */
227unsigned int tomoyo_quota_for_query;
228
229/**
230 * tomoyo_read_memory_counter - Check for memory usage in bytes.
231 *
232 * @head: Pointer to "struct tomoyo_io_buffer".
233 *
234 * Returns memory usage.
235 */
Tetsuo Handa8fbe71f2010-06-16 16:29:59 +0900236void tomoyo_read_memory_counter(struct tomoyo_io_buffer *head)
Tetsuo Handac3ef1502010-05-17 10:12:46 +0900237{
Tetsuo Handaf23571e2010-06-24 14:57:16 +0900238 if (!head->r.eof) {
Tetsuo Handac3ef1502010-05-17 10:12:46 +0900239 const unsigned int policy
240 = atomic_read(&tomoyo_policy_memory_size);
241 const unsigned int query = tomoyo_query_memory_size;
242 char buffer[64];
243
244 memset(buffer, 0, sizeof(buffer));
245 if (tomoyo_quota_for_policy)
246 snprintf(buffer, sizeof(buffer) - 1,
247 " (Quota: %10u)",
248 tomoyo_quota_for_policy);
249 else
250 buffer[0] = '\0';
251 tomoyo_io_printf(head, "Policy: %10u%s\n", policy,
252 buffer);
253 if (tomoyo_quota_for_query)
254 snprintf(buffer, sizeof(buffer) - 1,
255 " (Quota: %10u)",
256 tomoyo_quota_for_query);
257 else
258 buffer[0] = '\0';
259 tomoyo_io_printf(head, "Query lists: %10u%s\n", query,
260 buffer);
261 tomoyo_io_printf(head, "Total: %10u\n", policy + query);
Tetsuo Handaf23571e2010-06-24 14:57:16 +0900262 head->r.eof = true;
Tetsuo Handac3ef1502010-05-17 10:12:46 +0900263 }
Tetsuo Handac3ef1502010-05-17 10:12:46 +0900264}
265
266/**
267 * tomoyo_write_memory_quota - Set memory quota.
268 *
269 * @head: Pointer to "struct tomoyo_io_buffer".
270 *
271 * Returns 0.
272 */
273int tomoyo_write_memory_quota(struct tomoyo_io_buffer *head)
274{
275 char *data = head->write_buf;
276 unsigned int size;
277
278 if (sscanf(data, "Policy: %u", &size) == 1)
279 tomoyo_quota_for_policy = size;
280 else if (sscanf(data, "Query lists: %u", &size) == 1)
281 tomoyo_quota_for_query = size;
282 return 0;
283}