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;
123 bool is_ima_template = false;
133 * PCR used is always the same (config option) in
134 * little-endian format
136 ima_putc(m, &pcr, sizeof pcr);
138 /* 2nd: template digest */
139 ima_putc(m, e->digest, TPM_DIGEST_SIZE);
141 /* 3rd: template name size */
142 namelen = strlen(e->template_desc->name);
143 ima_putc(m, &namelen, sizeof namelen);
145 /* 4th: template name */
146 ima_putc(m, e->template_desc->name, namelen);
148 /* 5th: template length (except for 'ima' template) */
149 if (strcmp(e->template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0)
150 is_ima_template = true;
152 if (!is_ima_template)
153 ima_putc(m, &e->template_data_len,
154 sizeof(e->template_data_len));
156 /* 6th: template specific data */
157 for (i = 0; i < e->template_desc->num_fields; i++) {
158 enum ima_show_type show = IMA_SHOW_BINARY;
159 struct ima_template_field *field = e->template_desc->fields[i];
161 if (is_ima_template && strcmp(field->field_id, "d") == 0)
162 show = IMA_SHOW_BINARY_NO_FIELD_LEN;
163 field->field_show(m, show, &e->template_data[i]);
168 static const struct seq_operations ima_measurments_seqops = {
169 .start = ima_measurements_start,
170 .next = ima_measurements_next,
171 .stop = ima_measurements_stop,
172 .show = ima_measurements_show
175 static int ima_measurements_open(struct inode *inode, struct file *file)
177 return seq_open(file, &ima_measurments_seqops);
180 static const struct file_operations ima_measurements_ops = {
181 .open = ima_measurements_open,
184 .release = seq_release,
187 void ima_print_digest(struct seq_file *m, u8 *digest, int size)
191 for (i = 0; i < size; i++)
192 seq_printf(m, "%02x", *(digest + i));
196 static int ima_ascii_measurements_show(struct seq_file *m, void *v)
198 /* the list never shrinks, so we don't need a lock here */
199 struct ima_queue_entry *qe = v;
200 struct ima_template_entry *e;
208 /* 1st: PCR used (config option) */
209 seq_printf(m, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX);
211 /* 2nd: SHA1 template hash */
212 ima_print_digest(m, e->digest, TPM_DIGEST_SIZE);
214 /* 3th: template name */
215 seq_printf(m, " %s", e->template_desc->name);
217 /* 4th: template specific data */
218 for (i = 0; i < e->template_desc->num_fields; i++) {
220 if (e->template_data[i].len == 0)
223 e->template_desc->fields[i]->field_show(m, IMA_SHOW_ASCII,
224 &e->template_data[i]);
230 static const struct seq_operations ima_ascii_measurements_seqops = {
231 .start = ima_measurements_start,
232 .next = ima_measurements_next,
233 .stop = ima_measurements_stop,
234 .show = ima_ascii_measurements_show
237 static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
239 return seq_open(file, &ima_ascii_measurements_seqops);
242 static const struct file_operations ima_ascii_measurements_ops = {
243 .open = ima_ascii_measurements_open,
246 .release = seq_release,
249 static ssize_t ima_write_policy(struct file *file, const char __user *buf,
250 size_t datalen, loff_t *ppos)
255 if (datalen >= PAGE_SIZE)
256 datalen = PAGE_SIZE - 1;
258 /* No partial writes. */
264 data = kmalloc(datalen + 1, GFP_KERNEL);
268 *(data + datalen) = '\0';
271 if (copy_from_user(data, buf, datalen))
274 result = ima_parse_add_rule(data);
282 static struct dentry *ima_dir;
283 static struct dentry *binary_runtime_measurements;
284 static struct dentry *ascii_runtime_measurements;
285 static struct dentry *runtime_measurements_count;
286 static struct dentry *violations;
287 static struct dentry *ima_policy;
289 static atomic_t policy_opencount = ATOMIC_INIT(1);
291 * ima_open_policy: sequentialize access to the policy file
293 static int ima_open_policy(struct inode * inode, struct file * filp)
295 /* No point in being allowed to open it if you aren't going to write */
296 if (!(filp->f_flags & O_WRONLY))
298 if (atomic_dec_and_test(&policy_opencount))
304 * ima_release_policy - start using the new measure policy rules.
306 * Initially, ima_measure points to the default policy rules, now
307 * point to the new policy rules, and remove the securityfs policy file,
308 * assuming a valid policy.
310 static int ima_release_policy(struct inode *inode, struct file *file)
315 atomic_set(&policy_opencount, 1);
319 securityfs_remove(ima_policy);
324 static const struct file_operations ima_measure_policy_ops = {
325 .open = ima_open_policy,
326 .write = ima_write_policy,
327 .release = ima_release_policy,
328 .llseek = generic_file_llseek,
331 int __init ima_fs_init(void)
333 ima_dir = securityfs_create_dir("ima", NULL);
337 binary_runtime_measurements =
338 securityfs_create_file("binary_runtime_measurements",
339 S_IRUSR | S_IRGRP, ima_dir, NULL,
340 &ima_measurements_ops);
341 if (IS_ERR(binary_runtime_measurements))
344 ascii_runtime_measurements =
345 securityfs_create_file("ascii_runtime_measurements",
346 S_IRUSR | S_IRGRP, ima_dir, NULL,
347 &ima_ascii_measurements_ops);
348 if (IS_ERR(ascii_runtime_measurements))
351 runtime_measurements_count =
352 securityfs_create_file("runtime_measurements_count",
353 S_IRUSR | S_IRGRP, ima_dir, NULL,
354 &ima_measurements_count_ops);
355 if (IS_ERR(runtime_measurements_count))
359 securityfs_create_file("violations", S_IRUSR | S_IRGRP,
360 ima_dir, NULL, &ima_htable_violations_ops);
361 if (IS_ERR(violations))
364 ima_policy = securityfs_create_file("policy",
367 &ima_measure_policy_ops);
368 if (IS_ERR(ima_policy))
373 securityfs_remove(violations);
374 securityfs_remove(runtime_measurements_count);
375 securityfs_remove(ascii_runtime_measurements);
376 securityfs_remove(binary_runtime_measurements);
377 securityfs_remove(ima_dir);
378 securityfs_remove(ima_policy);