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;
123 u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
124 bool is_ima_template = false;
132 template_name = (e->template_desc->name[0] != '\0') ?
133 e->template_desc->name : e->template_desc->fmt;
137 * PCR used is always the same (config option) in
138 * little-endian format
140 ima_putc(m, &pcr, sizeof(pcr));
142 /* 2nd: template digest */
143 ima_putc(m, e->digest, TPM_DIGEST_SIZE);
145 /* 3rd: template name size */
146 namelen = strlen(template_name);
147 ima_putc(m, &namelen, sizeof(namelen));
149 /* 4th: template name */
150 ima_putc(m, template_name, namelen);
152 /* 5th: template length (except for 'ima' template) */
153 if (strcmp(template_name, IMA_TEMPLATE_IMA_NAME) == 0)
154 is_ima_template = true;
156 if (!is_ima_template)
157 ima_putc(m, &e->template_data_len,
158 sizeof(e->template_data_len));
160 /* 6th: template specific data */
161 for (i = 0; i < e->template_desc->num_fields; i++) {
162 enum ima_show_type show = IMA_SHOW_BINARY;
163 struct ima_template_field *field = e->template_desc->fields[i];
165 if (is_ima_template && strcmp(field->field_id, "d") == 0)
166 show = IMA_SHOW_BINARY_NO_FIELD_LEN;
167 if (is_ima_template && strcmp(field->field_id, "n") == 0)
168 show = IMA_SHOW_BINARY_OLD_STRING_FMT;
169 field->field_show(m, show, &e->template_data[i]);
174 static const struct seq_operations ima_measurments_seqops = {
175 .start = ima_measurements_start,
176 .next = ima_measurements_next,
177 .stop = ima_measurements_stop,
178 .show = ima_measurements_show
181 static int ima_measurements_open(struct inode *inode, struct file *file)
183 return seq_open(file, &ima_measurments_seqops);
186 static const struct file_operations ima_measurements_ops = {
187 .open = ima_measurements_open,
190 .release = seq_release,
193 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size)
197 for (i = 0; i < size; i++)
198 seq_printf(m, "%02x", *(digest + i));
202 static int ima_ascii_measurements_show(struct seq_file *m, void *v)
204 /* the list never shrinks, so we don't need a lock here */
205 struct ima_queue_entry *qe = v;
206 struct ima_template_entry *e;
215 template_name = (e->template_desc->name[0] != '\0') ?
216 e->template_desc->name : e->template_desc->fmt;
218 /* 1st: PCR used (config option) */
219 seq_printf(m, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX);
221 /* 2nd: SHA1 template hash */
222 ima_print_digest(m, e->digest, TPM_DIGEST_SIZE);
224 /* 3th: template name */
225 seq_printf(m, " %s", template_name);
227 /* 4th: template specific data */
228 for (i = 0; i < e->template_desc->num_fields; i++) {
230 if (e->template_data[i].len == 0)
233 e->template_desc->fields[i]->field_show(m, IMA_SHOW_ASCII,
234 &e->template_data[i]);
240 static const struct seq_operations ima_ascii_measurements_seqops = {
241 .start = ima_measurements_start,
242 .next = ima_measurements_next,
243 .stop = ima_measurements_stop,
244 .show = ima_ascii_measurements_show
247 static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
249 return seq_open(file, &ima_ascii_measurements_seqops);
252 static const struct file_operations ima_ascii_measurements_ops = {
253 .open = ima_ascii_measurements_open,
256 .release = seq_release,
259 static ssize_t ima_write_policy(struct file *file, const char __user *buf,
260 size_t datalen, loff_t *ppos)
265 if (datalen >= PAGE_SIZE)
266 datalen = PAGE_SIZE - 1;
268 /* No partial writes. */
274 data = kmalloc(datalen + 1, GFP_KERNEL);
278 *(data + datalen) = '\0';
281 if (copy_from_user(data, buf, datalen))
284 result = ima_parse_add_rule(data);
292 static struct dentry *ima_dir;
293 static struct dentry *binary_runtime_measurements;
294 static struct dentry *ascii_runtime_measurements;
295 static struct dentry *runtime_measurements_count;
296 static struct dentry *violations;
297 static struct dentry *ima_policy;
303 static unsigned long ima_fs_flags;
306 * ima_open_policy: sequentialize access to the policy file
308 static int ima_open_policy(struct inode *inode, struct file *filp)
310 /* No point in being allowed to open it if you aren't going to write */
311 if (!(filp->f_flags & O_WRONLY))
313 if (test_and_set_bit(IMA_FS_BUSY, &ima_fs_flags))
319 * ima_release_policy - start using the new measure policy rules.
321 * Initially, ima_measure points to the default policy rules, now
322 * point to the new policy rules, and remove the securityfs policy file,
323 * assuming a valid policy.
325 static int ima_release_policy(struct inode *inode, struct file *file)
327 const char *cause = valid_policy ? "completed" : "failed";
329 pr_info("IMA: policy update %s\n", cause);
330 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
331 "policy_update", cause, !valid_policy, 0);
336 clear_bit(IMA_FS_BUSY, &ima_fs_flags);
340 securityfs_remove(ima_policy);
345 static const struct file_operations ima_measure_policy_ops = {
346 .open = ima_open_policy,
347 .write = ima_write_policy,
348 .release = ima_release_policy,
349 .llseek = generic_file_llseek,
352 int __init ima_fs_init(void)
354 ima_dir = securityfs_create_dir("ima", NULL);
358 binary_runtime_measurements =
359 securityfs_create_file("binary_runtime_measurements",
360 S_IRUSR | S_IRGRP, ima_dir, NULL,
361 &ima_measurements_ops);
362 if (IS_ERR(binary_runtime_measurements))
365 ascii_runtime_measurements =
366 securityfs_create_file("ascii_runtime_measurements",
367 S_IRUSR | S_IRGRP, ima_dir, NULL,
368 &ima_ascii_measurements_ops);
369 if (IS_ERR(ascii_runtime_measurements))
372 runtime_measurements_count =
373 securityfs_create_file("runtime_measurements_count",
374 S_IRUSR | S_IRGRP, ima_dir, NULL,
375 &ima_measurements_count_ops);
376 if (IS_ERR(runtime_measurements_count))
380 securityfs_create_file("violations", S_IRUSR | S_IRGRP,
381 ima_dir, NULL, &ima_htable_violations_ops);
382 if (IS_ERR(violations))
385 ima_policy = securityfs_create_file("policy",
388 &ima_measure_policy_ops);
389 if (IS_ERR(ima_policy))
394 securityfs_remove(violations);
395 securityfs_remove(runtime_measurements_count);
396 securityfs_remove(ascii_runtime_measurements);
397 securityfs_remove(binary_runtime_measurements);
398 securityfs_remove(ima_dir);
399 securityfs_remove(ima_policy);