aboutsummaryrefslogtreecommitdiffstats
path: root/security/keys/proc.c
blob: 9d01021ca0c8cdd9c25c8292daff990204ecf466 (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
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
/* proc.c: proc files for key database enumeration
 *
 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <asm/errno.h>
#include "internal.h"

#ifdef CONFIG_KEYS_DEBUG_PROC_KEYS
static int proc_keys_open(struct inode *inode, struct file *file);
static void *proc_keys_start(struct seq_file *p, loff_t *_pos);
static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos);
static void proc_keys_stop(struct seq_file *p, void *v);
static int proc_keys_show(struct seq_file *m, void *v);

static const struct seq_operations proc_keys_ops = {
	.start	= proc_keys_start,
	.next	= proc_keys_next,
	.stop	= proc_keys_stop,
	.show	= proc_keys_show,
};

static const struct file_operations proc_keys_fops = {
	.open		= proc_keys_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};
#endif

static int proc_key_users_open(struct inode *inode, struct file *file);
static void *proc_key_users_start(struct seq_file *p, loff_t *_pos);
static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos);
static void proc_key_users_stop(struct seq_file *p, void *v);
static int proc_key_users_show(struct seq_file *m, void *v);

static const struct seq_operations proc_key_users_ops = {
	.start	= proc_key_users_start,
	.next	= proc_key_users_next,
	.stop	= proc_key_users_stop,
	.show	= proc_key_users_show,
};

static const struct file_operations proc_key_users_fops = {
	.open		= proc_key_users_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

/*****************************************************************************/
/*
 * declare the /proc files
 */
static int __init key_proc_init(void)
{
	struct proc_dir_entry *p;

#ifdef CONFIG_KEYS_DEBUG_PROC_KEYS
	p = proc_create("keys", 0, NULL, &proc_keys_fops);
	if (!p)
		panic("Cannot create /proc/keys\n");
#endif

	p = proc_create("key-users", 0, NULL, &proc_key_users_fops);
	if (!p)
		panic("Cannot create /proc/key-users\n");

	return 0;

} /* end key_proc_init() */

__initcall(key_proc_init);

/*****************************************************************************/
/*
 * implement "/proc/keys" to provides a list of the keys on the system
 */
#ifdef CONFIG_KEYS_DEBUG_PROC_KEYS

static struct rb_node *key_serial_next(struct rb_node *n)
{
	struct user_namespace *user_ns = current_user_ns();

	n = rb_next(n);
	while (n) {
		struct key *key = rb_entry(n, struct key, serial_node);
		if (key->user->user_ns == user_ns)
			break;
		n = rb_next(n);
	}
	return n;
}

static int proc_keys_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &proc_keys_ops);
}

static struct key *find_ge_key(key_serial_t id)
{
	struct user_namespace *user_ns = current_user_ns();
	struct rb_node *n = key_serial_tree.rb_node;
	struct key *minkey = NULL;

	while (n) {
		struct key *key = rb_entry(n, struct key, serial_node);
		if (id < key->serial) {
			if (!minkey || minkey->serial > key->serial)
				minkey = key;
			n = n->rb_left;
		} else if (id > key->serial) {
			n = n->rb_right;
		} else {
			minkey = key;
			break;
		}
		key = NULL;
	}

	if (!minkey)
		return NULL;

	for (;;) {
		if (minkey->user->user_ns == user_ns)
			return minkey;
		n = rb_next(&minkey->serial_node);
		if (!n)
			return NULL;
		minkey = rb_entry(n, struct key, serial_node);
	}
}

static void *proc_keys_start(struct seq_file *p, loff_t *_pos)
	__acquires(key_serial_lock)
{
	key_serial_t pos = *_pos;
	struct key *key;

	spin_lock(&key_serial_lock);

	if (*_pos > INT_MAX)
		return NULL;
	key = find_ge_key(pos);
	if (!key)
		return NULL;
	*_pos = key->serial;
	return &key->serial_node;
}

static inline key_serial_t key_node_serial(struct rb_node *n)
{
	struct key *key = rb_entry(n, struct key, serial_node);
	return key->serial;
}

static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
{
	struct rb_node *n;

	n = key_serial_next(v);
	if (n)
		*_pos = key_node_serial(n);
	return n;
}

static void proc_keys_stop(struct seq_file *p, void *v)
	__releases(key_serial_lock)
{
	spin_unlock(&key_serial_lock);
}

static int proc_keys_show(struct seq_file *m, void *v)
{
	struct rb_node *_p = v;
	struct key *key = rb_entry(_p, struct key, serial_node);
	struct timespec now;
	unsigned long timo;
	char xbuf[12];
	int rc;

	/* check whether the current task is allowed to view the key (assuming
	 * non-possession)
	 * - the caller holds a spinlock, and thus the RCU read lock, making our
	 *   access to __current_cred() safe
	 */
	rc = key_task_permission(make_key_ref(key, 0), current_cred(),
				 KEY_VIEW);
	if (rc < 0)
		return 0;

	now = current_kernel_time();

	rcu_read_lock();

	/* come up with a suitable timeout value */
	if (key->expiry == 0) {
		memcpy(xbuf, "perm", 5);
	} else if (now.tv_sec >= key->expiry) {
		memcpy(xbuf, "expd", 5);
	} else {
		timo = key->expiry - now.tv_sec;

		if (timo < 60)
			sprintf(xbuf, "%lus", timo);
		else if (timo < 60*60)
			sprintf(xbuf, "%lum", timo / 60);
		else if (timo < 60*60*24)
			sprintf(xbuf, "%luh", timo / (60*60));
		else if (timo < 60*60*24*7)
			sprintf(xbuf, "%lud", timo / (60*60*24));
		else
			sprintf(xbuf, "%luw", timo / (60*60*24*7));
	}

#define showflag(KEY, LETTER, FLAG) \
	(test_bit(FLAG,	&(KEY)->flags) ? LETTER : '-')

	seq_printf(m, "%08x %c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
		   key->serial,
		   showflag(key, 'I', KEY_FLAG_INSTANTIATED),
		   showflag(key, 'R', KEY_FLAG_REVOKED),
		   showflag(key, 'D', KEY_FLAG_DEAD),
		   showflag(key, 'Q', KEY_FLAG_IN_QUOTA),
		   showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT),
		   showflag(key, 'N', KEY_FLAG_NEGATIVE),
		   atomic_read(&key->usage),
		   xbuf,
		   key->perm,
		   key->uid,
		   key->gid,
		   key->type->name);

#undef showflag

	if (key->type->describe)
		key->type->describe(key, m);
	seq_putc(m, '\n');

	rcu_read_unlock();
	return 0;
}

#endif /* CONFIG_KEYS_DEBUG_PROC_KEYS */

static struct rb_node *__key_user_next(struct rb_node *n)
{
	while (n) {
		struct key_user *user = rb_entry(n, struct key_user, node);
		if (user->user_ns == current_user_ns())
			break;
		n = rb_next(n);
	}
	return n;
}

static struct rb_node *key_user_next(struct rb_node *n)
{
	return __key_user_next(rb_next(n));
}

static struct rb_node *key_user_first(struct rb_root *r)
{
	struct rb_node *n = rb_first(r);
	return __key_user_next(n);
}

/*****************************************************************************/
/*
 * implement "/proc/key-users" to provides a list of the key users
 */
static int proc_key_users_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &proc_key_users_ops);
}

static void *proc_key_users_start(struct seq_file *p, loff_t *_pos)
	__acquires(key_user_lock)
{
	struct rb_node *_p;
	loff_t pos = *_pos;

	spin_lock(&key_user_lock);

	_p = key_user_first(&key_user_tree);
	while (pos > 0 && _p) {
		pos--;
		_p = key_user_next(_p);
	}

	return _p;
}

static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos)
{
	(*_pos)++;
	return key_user_next((struct rb_node *) v);
}

static void proc_key_users_stop(struct seq_file *p, void *v)
	__releases(key_user_lock)
{
	spin_unlock(&key_user_lock);
}

static int proc_key_users_show(struct seq_file *m, void *v)
{
	struct rb_node *_p = v;
	struct key_user *user = rb_entry(_p, struct key_user, node);
	unsigned maxkeys = (user->uid == 0) ?
		key_quota_root_maxkeys : key_quota_maxkeys;
	unsigned maxbytes = (user->uid == 0) ?
		key_quota_root_maxbytes : key_quota_maxbytes;

	seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
		   user->uid,
		   atomic_read(&user->usage),
		   atomic_read(&user->nkeys),
		   atomic_read(&user->nikeys),
		   user->qnkeys,
		   maxkeys,
		   user->qnbytes,
		   maxbytes);

	return 0;

}