summaryrefslogtreecommitdiffstats
path: root/security/tomoyo/securityfs_if.c
blob: fb9bf99deb35de73a19c894c49328990ad5288fd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
// SPDX-License-Identifier: GPL-2.0
/*
 * security/tomoyo/securityfs_if.c
 *
 * Copyright (C) 2005-2011  NTT DATA CORPORATION
 */

#include <linux/security.h>
#include "common.h"

/**
 * tomoyo_check_task_acl - Check permission for task operation.
 *
 * @r:   Pointer to "struct tomoyo_request_info".
 * @ptr: Pointer to "struct tomoyo_acl_info".
 *
 * Returns true if granted, false otherwise.
 */
static bool tomoyo_check_task_acl(struct tomoyo_request_info *r,
				  const struct tomoyo_acl_info *ptr)
{
	const struct tomoyo_task_acl *acl = container_of(ptr, typeof(*acl),
							 head);
	return !tomoyo_pathcmp(r->param.task.domainname, acl->domainname);
}

/**
 * tomoyo_write_self - write() for /sys/kernel/security/tomoyo/self_domain interface.
 *
 * @file:  Pointer to "struct file".
 * @buf:   Domainname to transit to.
 * @count: Size of @buf.
 * @ppos:  Unused.
 *
 * Returns @count on success, negative value otherwise.
 *
 * If domain transition was permitted but the domain transition failed, this
 * function returns error rather than terminating current thread with SIGKILL.
 */
static ssize_t tomoyo_write_self(struct file *file, const char __user *buf,
			      size_t count, loff_t *ppos)
{
	char *data;
	int error;
	if (!count || count >= TOMOYO_EXEC_TMPSIZE - 10)
		return -ENOMEM;
	data = memdup_user_nul(buf, count);
	if (IS_ERR(data))
		return PTR_ERR(data);
	tomoyo_normalize_line(data);
	if (tomoyo_correct_domain(data)) {
		const int idx = tomoyo_read_lock();
		struct tomoyo_path_info name;
		struct tomoyo_request_info r;
		name.name = data;
		tomoyo_fill_path_info(&name);
		/* Check "task manual_domain_transition" permission. */
		tomoyo_init_request_info(&r, NULL, TOMOYO_MAC_FILE_EXECUTE);
		r.param_type = TOMOYO_TYPE_MANUAL_TASK_ACL;
		r.param.task.domainname = &name;
		tomoyo_check_acl(&r, tomoyo_check_task_acl);
		if (!r.granted)
			error = -EPERM;
		else {
			struct tomoyo_domain_info *new_domain =
				tomoyo_assign_domain(data, true);
			if (!new_domain) {
				error = -ENOENT;
			} else {
				struct cred *cred = prepare_creds();
				if (!cred) {
					error = -ENOMEM;
				} else {
					struct tomoyo_domain_info *old_domain =
						cred->security;
					cred->security = new_domain;
					atomic_inc(&new_domain->users);
					atomic_dec(&old_domain->users);
					commit_creds(cred);
					error = 0;
				}
			}
		}
		tomoyo_read_unlock(idx);
	} else
		error = -EINVAL;
	kfree(data);
	return error ? error : count;
}

/**
 * tomoyo_read_self - read() for /sys/kernel/security/tomoyo/self_domain interface.
 *
 * @file:  Pointer to "struct file".
 * @buf:   Domainname which current thread belongs to.
 * @count: Size of @buf.
 * @ppos:  Bytes read by now.
 *
 * Returns read size on success, negative value otherwise.
 */
static ssize_t tomoyo_read_self(struct file *file, char __user *buf,
				size_t count, loff_t *ppos)
{
	const char *domain = tomoyo_domain()->domainname->name;
	loff_t len = strlen(domain);
	loff_t pos = *ppos;
	if (pos >= len || !count)
		return 0;
	len -= pos;
	if (count < len)
		len = count;
	if (copy_to_user(buf, domain + pos, len))
		return -EFAULT;
	*ppos += len;
	return len;
}

/* Operations for /sys/kernel/security/tomoyo/self_domain interface. */
static const struct file_operations tomoyo_self_operations = {
	.write = tomoyo_write_self,
	.read  = tomoyo_read_self,
};

/**
 * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
 *
 * @inode: Pointer to "struct inode".
 * @file:  Pointer to "struct file".
 *
 * Returns 0 on success, negative value otherwise.
 */
static int tomoyo_open(struct inode *inode, struct file *file)
{
	const int key = ((u8 *) file_inode(file)->i_private)
		- ((u8 *) NULL);
	return tomoyo_open_control(key, file);
}

/**
 * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
 *
 * @file:  Pointer to "struct file".
 *
 */
static int tomoyo_release(struct inode *inode, struct file *file)
{
	tomoyo_close_control(file->private_data);
	return 0;
}

/**
 * tomoyo_poll - poll() for /sys/kernel/security/tomoyo/ interface.
 *
 * @file: Pointer to "struct file".
 * @wait: Pointer to "poll_table". Maybe NULL.
 *
 * Returns POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM if ready to read/write,
 * POLLOUT | POLLWRNORM otherwise.
 */
static __poll_t tomoyo_poll(struct file *file, poll_table *wait)
{
	return tomoyo_poll_control(file, wait);
}

/**
 * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
 *
 * @file:  Pointer to "struct file".
 * @buf:   Pointer to buffer.
 * @count: Size of @buf.
 * @ppos:  Unused.
 *
 * Returns bytes read on success, negative value otherwise.
 */
static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
			   loff_t *ppos)
{
	return tomoyo_read_control(file->private_data, buf, count);
}

/**
 * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
 *
 * @file:  Pointer to "struct file".
 * @buf:   Pointer to buffer.
 * @count: Size of @buf.
 * @ppos:  Unused.
 *
 * Returns @count on success, negative value otherwise.
 */
static ssize_t tomoyo_write(struct file *file, const char __user *buf,
			    size_t count, loff_t *ppos)
{
	return tomoyo_write_control(file->private_data, buf, count);
}

/*
 * tomoyo_operations is a "struct file_operations" which is used for handling
 * /sys/kernel/security/tomoyo/ interface.
 *
 * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
 * See tomoyo_io_buffer for internals.
 */
static const struct file_operations tomoyo_operations = {
	.open    = tomoyo_open,
	.release = tomoyo_release,
	.poll    = tomoyo_poll,
	.read    = tomoyo_read,
	.write   = tomoyo_write,
	.llseek  = noop_llseek,
};

/**
 * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
 *
 * @name:   The name of the interface file.
 * @mode:   The permission of the interface file.
 * @parent: The parent directory.
 * @key:    Type of interface.
 *
 * Returns nothing.
 */
static void __init tomoyo_create_entry(const char *name, const umode_t mode,
				       struct dentry *parent, const u8 key)
{
	securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
			       &tomoyo_operations);
}

/**
 * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
 *
 * Returns 0.
 */
static int __init tomoyo_initerface_init(void)
{
	struct dentry *tomoyo_dir;

	/* Don't create securityfs entries unless registered. */
	if (current_cred()->security != &tomoyo_kernel_domain)
		return 0;

	tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
	tomoyo_create_entry("query",            0600, tomoyo_dir,
			    TOMOYO_QUERY);
	tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
			    TOMOYO_DOMAINPOLICY);
	tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
			    TOMOYO_EXCEPTIONPOLICY);
	tomoyo_create_entry("audit",            0400, tomoyo_dir,
			    TOMOYO_AUDIT);
	tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
			    TOMOYO_PROCESS_STATUS);
	tomoyo_create_entry("stat",             0644, tomoyo_dir,
			    TOMOYO_STAT);
	tomoyo_create_entry("profile",          0600, tomoyo_dir,
			    TOMOYO_PROFILE);
	tomoyo_create_entry("manager",          0600, tomoyo_dir,
			    TOMOYO_MANAGER);
	tomoyo_create_entry("version",          0400, tomoyo_dir,
			    TOMOYO_VERSION);
	securityfs_create_file("self_domain", 0666, tomoyo_dir, NULL,
			       &tomoyo_self_operations);
	tomoyo_load_builtin_policy();
	return 0;
}

fs_initcall(tomoyo_initerface_init);