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1 /* proc.c: proc files for key database enumeration
2  *
3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
16 #include <linux/fs.h>
17 #include <linux/proc_fs.h>
18 #include <linux/seq_file.h>
19 #include <asm/errno.h>
20 #include "internal.h"
21 
22 #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS
23 static int proc_keys_open(struct inode *inode, struct file *file);
24 static void *proc_keys_start(struct seq_file *p, loff_t *_pos);
25 static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos);
26 static void proc_keys_stop(struct seq_file *p, void *v);
27 static int proc_keys_show(struct seq_file *m, void *v);
28 
29 static const struct seq_operations proc_keys_ops = {
30 	.start	= proc_keys_start,
31 	.next	= proc_keys_next,
32 	.stop	= proc_keys_stop,
33 	.show	= proc_keys_show,
34 };
35 
36 static const struct file_operations proc_keys_fops = {
37 	.open		= proc_keys_open,
38 	.read		= seq_read,
39 	.llseek		= seq_lseek,
40 	.release	= seq_release,
41 };
42 #endif
43 
44 static int proc_key_users_open(struct inode *inode, struct file *file);
45 static void *proc_key_users_start(struct seq_file *p, loff_t *_pos);
46 static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos);
47 static void proc_key_users_stop(struct seq_file *p, void *v);
48 static int proc_key_users_show(struct seq_file *m, void *v);
49 
50 static const struct seq_operations proc_key_users_ops = {
51 	.start	= proc_key_users_start,
52 	.next	= proc_key_users_next,
53 	.stop	= proc_key_users_stop,
54 	.show	= proc_key_users_show,
55 };
56 
57 static const struct file_operations proc_key_users_fops = {
58 	.open		= proc_key_users_open,
59 	.read		= seq_read,
60 	.llseek		= seq_lseek,
61 	.release	= seq_release,
62 };
63 
64 /*****************************************************************************/
65 /*
66  * declare the /proc files
67  */
key_proc_init(void)68 static int __init key_proc_init(void)
69 {
70 	struct proc_dir_entry *p;
71 
72 #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS
73 	p = proc_create("keys", 0, NULL, &proc_keys_fops);
74 	if (!p)
75 		panic("Cannot create /proc/keys\n");
76 #endif
77 
78 	p = proc_create("key-users", 0, NULL, &proc_key_users_fops);
79 	if (!p)
80 		panic("Cannot create /proc/key-users\n");
81 
82 	return 0;
83 
84 } /* end key_proc_init() */
85 
86 __initcall(key_proc_init);
87 
88 /*****************************************************************************/
89 /*
90  * implement "/proc/keys" to provides a list of the keys on the system
91  */
92 #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS
93 
proc_keys_open(struct inode * inode,struct file * file)94 static int proc_keys_open(struct inode *inode, struct file *file)
95 {
96 	return seq_open(file, &proc_keys_ops);
97 
98 }
99 
proc_keys_start(struct seq_file * p,loff_t * _pos)100 static void *proc_keys_start(struct seq_file *p, loff_t *_pos)
101 {
102 	struct rb_node *_p;
103 	loff_t pos = *_pos;
104 
105 	spin_lock(&key_serial_lock);
106 
107 	_p = rb_first(&key_serial_tree);
108 	while (pos > 0 && _p) {
109 		pos--;
110 		_p = rb_next(_p);
111 	}
112 
113 	return _p;
114 
115 }
116 
proc_keys_next(struct seq_file * p,void * v,loff_t * _pos)117 static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
118 {
119 	(*_pos)++;
120 	return rb_next((struct rb_node *) v);
121 
122 }
123 
proc_keys_stop(struct seq_file * p,void * v)124 static void proc_keys_stop(struct seq_file *p, void *v)
125 {
126 	spin_unlock(&key_serial_lock);
127 }
128 
proc_keys_show(struct seq_file * m,void * v)129 static int proc_keys_show(struct seq_file *m, void *v)
130 {
131 	struct rb_node *_p = v;
132 	struct key *key = rb_entry(_p, struct key, serial_node);
133 	struct timespec now;
134 	unsigned long timo;
135 	char xbuf[12];
136 	int rc;
137 
138 	/* check whether the current task is allowed to view the key (assuming
139 	 * non-possession)
140 	 * - the caller holds a spinlock, and thus the RCU read lock, making our
141 	 *   access to __current_cred() safe
142 	 */
143 	rc = key_task_permission(make_key_ref(key, 0), current_cred(),
144 				 KEY_VIEW);
145 	if (rc < 0)
146 		return 0;
147 
148 	now = current_kernel_time();
149 
150 	rcu_read_lock();
151 
152 	/* come up with a suitable timeout value */
153 	if (key->expiry == 0) {
154 		memcpy(xbuf, "perm", 5);
155 	}
156 	else if (now.tv_sec >= key->expiry) {
157 		memcpy(xbuf, "expd", 5);
158 	}
159 	else {
160 		timo = key->expiry - now.tv_sec;
161 
162 		if (timo < 60)
163 			sprintf(xbuf, "%lus", timo);
164 		else if (timo < 60*60)
165 			sprintf(xbuf, "%lum", timo / 60);
166 		else if (timo < 60*60*24)
167 			sprintf(xbuf, "%luh", timo / (60*60));
168 		else if (timo < 60*60*24*7)
169 			sprintf(xbuf, "%lud", timo / (60*60*24));
170 		else
171 			sprintf(xbuf, "%luw", timo / (60*60*24*7));
172 	}
173 
174 #define showflag(KEY, LETTER, FLAG) \
175 	(test_bit(FLAG,	&(KEY)->flags) ? LETTER : '-')
176 
177 	seq_printf(m, "%08x %c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
178 		   key->serial,
179 		   showflag(key, 'I', KEY_FLAG_INSTANTIATED),
180 		   showflag(key, 'R', KEY_FLAG_REVOKED),
181 		   showflag(key, 'D', KEY_FLAG_DEAD),
182 		   showflag(key, 'Q', KEY_FLAG_IN_QUOTA),
183 		   showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT),
184 		   showflag(key, 'N', KEY_FLAG_NEGATIVE),
185 		   atomic_read(&key->usage),
186 		   xbuf,
187 		   key->perm,
188 		   key->uid,
189 		   key->gid,
190 		   key->type->name);
191 
192 #undef showflag
193 
194 	if (key->type->describe)
195 		key->type->describe(key, m);
196 	seq_putc(m, '\n');
197 
198 	rcu_read_unlock();
199 
200 	return 0;
201 
202 }
203 
204 #endif /* CONFIG_KEYS_DEBUG_PROC_KEYS */
205 
206 /*****************************************************************************/
207 /*
208  * implement "/proc/key-users" to provides a list of the key users
209  */
proc_key_users_open(struct inode * inode,struct file * file)210 static int proc_key_users_open(struct inode *inode, struct file *file)
211 {
212 	return seq_open(file, &proc_key_users_ops);
213 
214 }
215 
proc_key_users_start(struct seq_file * p,loff_t * _pos)216 static void *proc_key_users_start(struct seq_file *p, loff_t *_pos)
217 {
218 	struct rb_node *_p;
219 	loff_t pos = *_pos;
220 
221 	spin_lock(&key_user_lock);
222 
223 	_p = rb_first(&key_user_tree);
224 	while (pos > 0 && _p) {
225 		pos--;
226 		_p = rb_next(_p);
227 	}
228 
229 	return _p;
230 
231 }
232 
proc_key_users_next(struct seq_file * p,void * v,loff_t * _pos)233 static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos)
234 {
235 	(*_pos)++;
236 	return rb_next((struct rb_node *) v);
237 
238 }
239 
proc_key_users_stop(struct seq_file * p,void * v)240 static void proc_key_users_stop(struct seq_file *p, void *v)
241 {
242 	spin_unlock(&key_user_lock);
243 }
244 
proc_key_users_show(struct seq_file * m,void * v)245 static int proc_key_users_show(struct seq_file *m, void *v)
246 {
247 	struct rb_node *_p = v;
248 	struct key_user *user = rb_entry(_p, struct key_user, node);
249 	unsigned maxkeys = (user->uid == 0) ?
250 		key_quota_root_maxkeys : key_quota_maxkeys;
251 	unsigned maxbytes = (user->uid == 0) ?
252 		key_quota_root_maxbytes : key_quota_maxbytes;
253 
254 	seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
255 		   user->uid,
256 		   atomic_read(&user->usage),
257 		   atomic_read(&user->nkeys),
258 		   atomic_read(&user->nikeys),
259 		   user->qnkeys,
260 		   maxkeys,
261 		   user->qnbytes,
262 		   maxbytes);
263 
264 	return 0;
265 
266 }
267