2 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
5 * Kylene Hall <kjhall@us.ibm.com>
6 * Reiner Sailer <sailer@us.ibm.com>
7 * Mimi Zohar <zohar@us.ibm.com>
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
15 * implemenents security file system for reporting
16 * current measurement list and IMA statistics
18 #include <linux/fcntl.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 #include <linux/seq_file.h>
22 #include <linux/rculist.h>
23 #include <linux/rcupdate.h>
24 #include <linux/parser.h>
28 static int valid_policy = 1;
30 static ssize_t ima_show_htable_value(char __user *buf, size_t count,
31 loff_t *ppos, atomic_long_t *val)
33 char tmpbuf[TMPBUFLEN];
36 len = scnprintf(tmpbuf, TMPBUFLEN, "%li\n", atomic_long_read(val));
37 return simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
40 static ssize_t ima_show_htable_violations(struct file *filp,
42 size_t count, loff_t *ppos)
44 return ima_show_htable_value(buf, count, ppos, &ima_htable.violations);
47 static const struct file_operations ima_htable_violations_ops = {
48 .read = ima_show_htable_violations,
49 .llseek = generic_file_llseek,
52 static ssize_t ima_show_measurements_count(struct file *filp,
54 size_t count, loff_t *ppos)
56 return ima_show_htable_value(buf, count, ppos, &ima_htable.len);
60 static const struct file_operations ima_measurements_count_ops = {
61 .read = ima_show_measurements_count,
62 .llseek = generic_file_llseek,
65 /* returns pointer to hlist_node */
66 static void *ima_measurements_start(struct seq_file *m, loff_t *pos)
69 struct ima_queue_entry *qe;
71 /* we need a lock since pos could point beyond last element */
73 list_for_each_entry_rcu(qe, &ima_measurements, later) {
83 static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos)
85 struct ima_queue_entry *qe = v;
87 /* lock protects when reading beyond last element
88 * against concurrent list-extension
91 qe = list_entry_rcu(qe->later.next, struct ima_queue_entry, later);
95 return (&qe->later == &ima_measurements) ? NULL : qe;
98 static void ima_measurements_stop(struct seq_file *m, void *v)
102 void ima_putc(struct seq_file *m, void *data, int datalen)
105 seq_putc(m, *(char *)data++);
110 * char[20]=template digest
111 * 32bit-le=template name size
112 * char[n]=template name
114 * eventdata[n]=template specific data
116 static int ima_measurements_show(struct seq_file *m, void *v)
118 /* the list never shrinks, so we don't need a lock here */
119 struct ima_queue_entry *qe = v;
120 struct ima_template_entry *e;
122 u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
132 * PCR used is always the same (config option) in
133 * little-endian format
135 ima_putc(m, &pcr, sizeof pcr);
137 /* 2nd: template digest */
138 ima_putc(m, e->digest, TPM_DIGEST_SIZE);
140 /* 3rd: template name size */
141 namelen = strlen(e->template_desc->name);
142 ima_putc(m, &namelen, sizeof namelen);
144 /* 4th: template name */
145 ima_putc(m, e->template_desc->name, namelen);
147 /* 5th: template length (except for 'ima' template) */
148 if (strcmp(e->template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
149 ima_putc(m, &e->template_data_len,
150 sizeof(e->template_data_len));
152 /* 6th: template specific data */
153 for (i = 0; i < e->template_desc->num_fields; i++) {
154 e->template_desc->fields[i]->field_show(m, IMA_SHOW_BINARY,
155 &e->template_data[i]);
160 static const struct seq_operations ima_measurments_seqops = {
161 .start = ima_measurements_start,
162 .next = ima_measurements_next,
163 .stop = ima_measurements_stop,
164 .show = ima_measurements_show
167 static int ima_measurements_open(struct inode *inode, struct file *file)
169 return seq_open(file, &ima_measurments_seqops);
172 static const struct file_operations ima_measurements_ops = {
173 .open = ima_measurements_open,
176 .release = seq_release,
179 void ima_print_digest(struct seq_file *m, u8 *digest, int size)
183 for (i = 0; i < size; i++)
184 seq_printf(m, "%02x", *(digest + i));
188 static int ima_ascii_measurements_show(struct seq_file *m, void *v)
190 /* the list never shrinks, so we don't need a lock here */
191 struct ima_queue_entry *qe = v;
192 struct ima_template_entry *e;
200 /* 1st: PCR used (config option) */
201 seq_printf(m, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX);
203 /* 2nd: SHA1 template hash */
204 ima_print_digest(m, e->digest, TPM_DIGEST_SIZE);
206 /* 3th: template name */
207 seq_printf(m, " %s", e->template_desc->name);
209 /* 4th: template specific data */
210 for (i = 0; i < e->template_desc->num_fields; i++) {
212 if (e->template_data[i].len == 0)
215 e->template_desc->fields[i]->field_show(m, IMA_SHOW_ASCII,
216 &e->template_data[i]);
222 static const struct seq_operations ima_ascii_measurements_seqops = {
223 .start = ima_measurements_start,
224 .next = ima_measurements_next,
225 .stop = ima_measurements_stop,
226 .show = ima_ascii_measurements_show
229 static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
231 return seq_open(file, &ima_ascii_measurements_seqops);
234 static const struct file_operations ima_ascii_measurements_ops = {
235 .open = ima_ascii_measurements_open,
238 .release = seq_release,
241 static ssize_t ima_write_policy(struct file *file, const char __user *buf,
242 size_t datalen, loff_t *ppos)
247 if (datalen >= PAGE_SIZE)
248 datalen = PAGE_SIZE - 1;
250 /* No partial writes. */
256 data = kmalloc(datalen + 1, GFP_KERNEL);
260 *(data + datalen) = '\0';
263 if (copy_from_user(data, buf, datalen))
266 result = ima_parse_add_rule(data);
274 static struct dentry *ima_dir;
275 static struct dentry *binary_runtime_measurements;
276 static struct dentry *ascii_runtime_measurements;
277 static struct dentry *runtime_measurements_count;
278 static struct dentry *violations;
279 static struct dentry *ima_policy;
281 static atomic_t policy_opencount = ATOMIC_INIT(1);
283 * ima_open_policy: sequentialize access to the policy file
285 static int ima_open_policy(struct inode * inode, struct file * filp)
287 /* No point in being allowed to open it if you aren't going to write */
288 if (!(filp->f_flags & O_WRONLY))
290 if (atomic_dec_and_test(&policy_opencount))
296 * ima_release_policy - start using the new measure policy rules.
298 * Initially, ima_measure points to the default policy rules, now
299 * point to the new policy rules, and remove the securityfs policy file,
300 * assuming a valid policy.
302 static int ima_release_policy(struct inode *inode, struct file *file)
307 atomic_set(&policy_opencount, 1);
311 securityfs_remove(ima_policy);
316 static const struct file_operations ima_measure_policy_ops = {
317 .open = ima_open_policy,
318 .write = ima_write_policy,
319 .release = ima_release_policy,
320 .llseek = generic_file_llseek,
323 int __init ima_fs_init(void)
325 ima_dir = securityfs_create_dir("ima", NULL);
329 binary_runtime_measurements =
330 securityfs_create_file("binary_runtime_measurements",
331 S_IRUSR | S_IRGRP, ima_dir, NULL,
332 &ima_measurements_ops);
333 if (IS_ERR(binary_runtime_measurements))
336 ascii_runtime_measurements =
337 securityfs_create_file("ascii_runtime_measurements",
338 S_IRUSR | S_IRGRP, ima_dir, NULL,
339 &ima_ascii_measurements_ops);
340 if (IS_ERR(ascii_runtime_measurements))
343 runtime_measurements_count =
344 securityfs_create_file("runtime_measurements_count",
345 S_IRUSR | S_IRGRP, ima_dir, NULL,
346 &ima_measurements_count_ops);
347 if (IS_ERR(runtime_measurements_count))
351 securityfs_create_file("violations", S_IRUSR | S_IRGRP,
352 ima_dir, NULL, &ima_htable_violations_ops);
353 if (IS_ERR(violations))
356 ima_policy = securityfs_create_file("policy",
359 &ima_measure_policy_ops);
360 if (IS_ERR(ima_policy))
365 securityfs_remove(violations);
366 securityfs_remove(runtime_measurements_count);
367 securityfs_remove(ascii_runtime_measurements);
368 securityfs_remove(binary_runtime_measurements);
369 securityfs_remove(ima_dir);
370 securityfs_remove(ima_policy);