1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * security/tomoyo/securityfs_if.c
4 *
5 * Copyright (C) 2005-2011 NTT DATA CORPORATION
6 */
7
8 #include <linux/security.h>
9 #include "common.h"
10
11 /**
12 * tomoyo_check_task_acl - Check permission for task operation.
13 *
14 * @r: Pointer to "struct tomoyo_request_info".
15 * @ptr: Pointer to "struct tomoyo_acl_info".
16 *
17 * Returns true if granted, false otherwise.
18 */
19 static bool tomoyo_check_task_acl(struct tomoyo_request_info *r,
20 const struct tomoyo_acl_info *ptr)
21 {
22 const struct tomoyo_task_acl *acl = container_of(ptr, typeof(*acl),
23 head);
24
25 return !tomoyo_pathcmp(r->param.task.domainname, acl->domainname);
26 }
27
28 /**
29 * tomoyo_write_self - write() for /sys/kernel/security/tomoyo/self_domain interface.
30 *
31 * @file: Pointer to "struct file".
32 * @buf: Domainname to transit to.
33 * @count: Size of @buf.
34 * @ppos: Unused.
35 *
36 * Returns @count on success, negative value otherwise.
37 *
38 * If domain transition was permitted but the domain transition failed, this
39 * function returns error rather than terminating current thread with SIGKILL.
40 */
41 static ssize_t tomoyo_write_self(struct file *file, const char __user *buf,
42 size_t count, loff_t *ppos)
43 {
44 char *data;
45 int error;
46
47 if (!count || count >= TOMOYO_EXEC_TMPSIZE - 10)
48 return -ENOMEM;
49 data = memdup_user_nul(buf, count);
50 if (IS_ERR(data))
51 return PTR_ERR(data);
52 tomoyo_normalize_line(data);
53 if (tomoyo_correct_domain(data)) {
54 const int idx = tomoyo_read_lock();
55 struct tomoyo_path_info name;
56 struct tomoyo_request_info r;
57
58 name.name = data;
59 tomoyo_fill_path_info(&name);
60 /* Check "task manual_domain_transition" permission. */
61 tomoyo_init_request_info(&r, NULL, TOMOYO_MAC_FILE_EXECUTE);
62 r.param_type = TOMOYO_TYPE_MANUAL_TASK_ACL;
63 r.param.task.domainname = &name;
64 tomoyo_check_acl(&r, tomoyo_check_task_acl);
65 if (!r.granted)
66 error = -EPERM;
67 else {
68 struct tomoyo_domain_info *new_domain =
69 tomoyo_assign_domain(data, true);
70 if (!new_domain) {
71 error = -ENOENT;
72 } else {
73 struct tomoyo_task *s = tomoyo_task(current);
74 struct tomoyo_domain_info *old_domain =
75 s->domain_info;
76
77 s->domain_info = new_domain;
78 atomic_inc(&new_domain->users);
79 atomic_dec(&old_domain->users);
80 error = 0;
81 }
82 }
83 tomoyo_read_unlock(idx);
84 } else
85 error = -EINVAL;
86 kfree(data);
87 return error ? error : count;
88 }
89
90 /**
91 * tomoyo_read_self - read() for /sys/kernel/security/tomoyo/self_domain interface.
92 *
93 * @file: Pointer to "struct file".
94 * @buf: Domainname which current thread belongs to.
95 * @count: Size of @buf.
96 * @ppos: Bytes read by now.
97 *
98 * Returns read size on success, negative value otherwise.
99 */
100 static ssize_t tomoyo_read_self(struct file *file, char __user *buf,
101 size_t count, loff_t *ppos)
102 {
103 const char *domain = tomoyo_domain()->domainname->name;
104 loff_t len = strlen(domain);
105 loff_t pos = *ppos;
106
107 if (pos >= len || !count)
108 return 0;
109 len -= pos;
110 if (count < len)
111 len = count;
112 if (copy_to_user(buf, domain + pos, len))
113 return -EFAULT;
114 *ppos += len;
115 return len;
116 }
117
118 /* Operations for /sys/kernel/security/tomoyo/self_domain interface. */
119 static const struct file_operations tomoyo_self_operations = {
120 .write = tomoyo_write_self,
121 .read = tomoyo_read_self,
122 };
123
124 /**
125 * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
126 *
127 * @inode: Pointer to "struct inode".
128 * @file: Pointer to "struct file".
129 *
130 * Returns 0 on success, negative value otherwise.
131 */
132 static int tomoyo_open(struct inode *inode, struct file *file)
133 {
134 const u8 key = (uintptr_t) file_inode(file)->i_private;
135
136 return tomoyo_open_control(key, file);
137 }
138
139 /**
140 * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
141 *
142 * @inode: Pointer to "struct inode".
143 * @file: Pointer to "struct file".
144 *
145 */
146 static int tomoyo_release(struct inode *inode, struct file *file)
147 {
148 tomoyo_close_control(file->private_data);
149 return 0;
150 }
151
152 /**
153 * tomoyo_poll - poll() for /sys/kernel/security/tomoyo/ interface.
154 *
155 * @file: Pointer to "struct file".
156 * @wait: Pointer to "poll_table". Maybe NULL.
157 *
158 * Returns EPOLLIN | EPOLLRDNORM | EPOLLOUT | EPOLLWRNORM if ready to read/write,
159 * EPOLLOUT | EPOLLWRNORM otherwise.
160 */
161 static __poll_t tomoyo_poll(struct file *file, poll_table *wait)
162 {
163 return tomoyo_poll_control(file, wait);
164 }
165
166 /**
167 * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
168 *
169 * @file: Pointer to "struct file".
170 * @buf: Pointer to buffer.
171 * @count: Size of @buf.
172 * @ppos: Unused.
173 *
174 * Returns bytes read on success, negative value otherwise.
175 */
176 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
177 loff_t *ppos)
178 {
179 return tomoyo_read_control(file->private_data, buf, count);
180 }
181
182 /**
183 * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
184 *
185 * @file: Pointer to "struct file".
186 * @buf: Pointer to buffer.
187 * @count: Size of @buf.
188 * @ppos: Unused.
189 *
190 * Returns @count on success, negative value otherwise.
191 */
192 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
193 size_t count, loff_t *ppos)
194 {
195 return tomoyo_write_control(file->private_data, buf, count);
196 }
197
198 /*
199 * tomoyo_operations is a "struct file_operations" which is used for handling
200 * /sys/kernel/security/tomoyo/ interface.
201 *
202 * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
203 * See tomoyo_io_buffer for internals.
204 */
205 static const struct file_operations tomoyo_operations = {
206 .open = tomoyo_open,
207 .release = tomoyo_release,
208 .poll = tomoyo_poll,
209 .read = tomoyo_read,
210 .write = tomoyo_write,
211 .llseek = noop_llseek,
212 };
213
214 /**
215 * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
216 *
217 * @name: The name of the interface file.
218 * @mode: The permission of the interface file.
219 * @parent: The parent directory.
220 * @key: Type of interface.
221 *
222 * Returns nothing.
223 */
224 static void __init tomoyo_create_entry(const char *name, const umode_t mode,
225 struct dentry *parent, const u8 key)
226 {
227 securityfs_create_file(name, mode, parent, (void *) (uintptr_t) key,
228 &tomoyo_operations);
229 }
230
231 /**
232 * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
233 *
234 * Returns 0.
235 */
236 static int __init tomoyo_initerface_init(void)
237 {
238 struct tomoyo_domain_info *domain;
239 struct dentry *tomoyo_dir;
240
241 if (!tomoyo_enabled)
242 return 0;
243 domain = tomoyo_domain();
244 /* Don't create securityfs entries unless registered. */
245 if (domain != &tomoyo_kernel_domain)
246 return 0;
247
248 tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
249 tomoyo_create_entry("query", 0600, tomoyo_dir,
250 TOMOYO_QUERY);
251 tomoyo_create_entry("domain_policy", 0600, tomoyo_dir,
252 TOMOYO_DOMAINPOLICY);
253 tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
254 TOMOYO_EXCEPTIONPOLICY);
255 tomoyo_create_entry("audit", 0400, tomoyo_dir,
256 TOMOYO_AUDIT);
257 tomoyo_create_entry(".process_status", 0600, tomoyo_dir,
258 TOMOYO_PROCESS_STATUS);
259 tomoyo_create_entry("stat", 0644, tomoyo_dir,
260 TOMOYO_STAT);
261 tomoyo_create_entry("profile", 0600, tomoyo_dir,
262 TOMOYO_PROFILE);
263 tomoyo_create_entry("manager", 0600, tomoyo_dir,
264 TOMOYO_MANAGER);
265 tomoyo_create_entry("version", 0400, tomoyo_dir,
266 TOMOYO_VERSION);
267 securityfs_create_file("self_domain", 0666, tomoyo_dir, NULL,
268 &tomoyo_self_operations);
269 tomoyo_load_builtin_policy();
270 return 0;
271 }
272
273 fs_initcall(tomoyo_initerface_init);
274
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.