[mirror_ubuntu-artful-kernel.git] / security / integrity / ima / ima_fs.c

/*
 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
 *
 * Authors:
 * Kylene Hall <kjhall@us.ibm.com>
 * Reiner Sailer <sailer@us.ibm.com>
 * Mimi Zohar <zohar@us.ibm.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, version 2 of the
 * License.
 *
 * File: ima_fs.c
 *	implemenents security file system for reporting
 *	current measurement list and IMA statistics
 */
#include <linux/fcntl.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/parser.h>
#include <linux/vmalloc.h>

#include "ima.h"

static DEFINE_MUTEX(ima_write_mutex);

static int valid_policy = 1;
#define TMPBUFLEN 12
static ssize_t ima_show_htable_value(char __user *buf, size_t count,
				     loff_t *ppos, atomic_long_t *val)
{
	char tmpbuf[TMPBUFLEN];
	ssize_t len;

	len = scnprintf(tmpbuf, TMPBUFLEN, "%li\n", atomic_long_read(val));
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
}

static ssize_t ima_show_htable_violations(struct file *filp,
					  char __user *buf,
					  size_t count, loff_t *ppos)
{
	return ima_show_htable_value(buf, count, ppos, &ima_htable.violations);
}

static const struct file_operations ima_htable_violations_ops = {
	.read = ima_show_htable_violations,
	.llseek = generic_file_llseek,
};

static ssize_t ima_show_measurements_count(struct file *filp,
					   char __user *buf,
					   size_t count, loff_t *ppos)
{
	return ima_show_htable_value(buf, count, ppos, &ima_htable.len);

}

static const struct file_operations ima_measurements_count_ops = {
	.read = ima_show_measurements_count,
	.llseek = generic_file_llseek,
};

/* returns pointer to hlist_node */
static void *ima_measurements_start(struct seq_file *m, loff_t *pos)
{
	loff_t l = *pos;
	struct ima_queue_entry *qe;

	/* we need a lock since pos could point beyond last element */
	rcu_read_lock();
	list_for_each_entry_rcu(qe, &ima_measurements, later) {
		if (!l--) {
			rcu_read_unlock();
			return qe;
		}
	}
	rcu_read_unlock();
	return NULL;
}

static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct ima_queue_entry *qe = v;

	/* lock protects when reading beyond last element
	 * against concurrent list-extension
	 */
	rcu_read_lock();
	qe = list_entry_rcu(qe->later.next, struct ima_queue_entry, later);
	rcu_read_unlock();
	(*pos)++;

	return (&qe->later == &ima_measurements) ? NULL : qe;
}

static void ima_measurements_stop(struct seq_file *m, void *v)
{
}

void ima_putc(struct seq_file *m, void *data, int datalen)
{
	while (datalen--)
		seq_putc(m, *(char *)data++);
}

/* print format:
 *       32bit-le=pcr#
 *       char[20]=template digest
 *       32bit-le=template name size
 *       char[n]=template name
 *       [eventdata length]
 *       eventdata[n]=template specific data
 */
static int ima_measurements_show(struct seq_file *m, void *v)
{
	/* the list never shrinks, so we don't need a lock here */
	struct ima_queue_entry *qe = v;
	struct ima_template_entry *e;
	char *template_name;
	int namelen;
	u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
	bool is_ima_template = false;
	int i;

	/* get entry */
	e = qe->entry;
	if (e == NULL)
		return -1;

	template_name = (e->template_desc->name[0] != '\0') ?
	    e->template_desc->name : e->template_desc->fmt;

	/*
	 * 1st: PCRIndex
	 * PCR used is always the same (config option) in
	 * little-endian format
	 */
	ima_putc(m, &pcr, sizeof(pcr));

	/* 2nd: template digest */
	ima_putc(m, e->digest, TPM_DIGEST_SIZE);

	/* 3rd: template name size */
	namelen = strlen(template_name);
	ima_putc(m, &namelen, sizeof(namelen));

	/* 4th:  template name */
	ima_putc(m, template_name, namelen);

	/* 5th:  template length (except for 'ima' template) */
	if (strcmp(template_name, IMA_TEMPLATE_IMA_NAME) == 0)
		is_ima_template = true;

	if (!is_ima_template)
		ima_putc(m, &e->template_data_len,
			 sizeof(e->template_data_len));

	/* 6th:  template specific data */
	for (i = 0; i < e->template_desc->num_fields; i++) {
		enum ima_show_type show = IMA_SHOW_BINARY;
		struct ima_template_field *field = e->template_desc->fields[i];

		if (is_ima_template && strcmp(field->field_id, "d") == 0)
			show = IMA_SHOW_BINARY_NO_FIELD_LEN;
		if (is_ima_template && strcmp(field->field_id, "n") == 0)
			show = IMA_SHOW_BINARY_OLD_STRING_FMT;
		field->field_show(m, show, &e->template_data[i]);
	}
	return 0;
}

static const struct seq_operations ima_measurments_seqops = {
	.start = ima_measurements_start,
	.next = ima_measurements_next,
	.stop = ima_measurements_stop,
	.show = ima_measurements_show
};

static int ima_measurements_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &ima_measurments_seqops);
}

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

void ima_print_digest(struct seq_file *m, u8 *digest, u32 size)
{
	u32 i;

	for (i = 0; i < size; i++)
		seq_printf(m, "%02x", *(digest + i));
}

/* print in ascii */
static int ima_ascii_measurements_show(struct seq_file *m, void *v)
{
	/* the list never shrinks, so we don't need a lock here */
	struct ima_queue_entry *qe = v;
	struct ima_template_entry *e;
	char *template_name;
	int i;

	/* get entry */
	e = qe->entry;
	if (e == NULL)
		return -1;

	template_name = (e->template_desc->name[0] != '\0') ?
	    e->template_desc->name : e->template_desc->fmt;

	/* 1st: PCR used (config option) */
	seq_printf(m, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX);

	/* 2nd: SHA1 template hash */
	ima_print_digest(m, e->digest, TPM_DIGEST_SIZE);

	/* 3th:  template name */
	seq_printf(m, " %s", template_name);

	/* 4th:  template specific data */
	for (i = 0; i < e->template_desc->num_fields; i++) {
		seq_puts(m, " ");
		if (e->template_data[i].len == 0)
			continue;

		e->template_desc->fields[i]->field_show(m, IMA_SHOW_ASCII,
							&e->template_data[i]);
	}
	seq_puts(m, "\n");
	return 0;
}

static const struct seq_operations ima_ascii_measurements_seqops = {
	.start = ima_measurements_start,
	.next = ima_measurements_next,
	.stop = ima_measurements_stop,
	.show = ima_ascii_measurements_show
};

static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &ima_ascii_measurements_seqops);
}

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

static ssize_t ima_read_policy(char *path)
{
	void *data;
	char *datap;
	loff_t size;
	int rc, pathlen = strlen(path);

	char *p;

	/* remove \n */
	datap = path;
	strsep(&datap, "\n");

	rc = kernel_read_file_from_path(path, &data, &size, 0, READING_POLICY);
	if (rc < 0) {
		pr_err("Unable to open file: %s (%d)", path, rc);
		return rc;
	}

	datap = data;
	while (size > 0 && (p = strsep(&datap, "\n"))) {
		pr_debug("rule: %s\n", p);
		rc = ima_parse_add_rule(p);
		if (rc < 0)
			break;
		size -= rc;
	}

	vfree(data);
	if (rc < 0)
		return rc;
	else if (size)
		return -EINVAL;
	else
		return pathlen;
}

static ssize_t ima_write_policy(struct file *file, const char __user *buf,
				size_t datalen, loff_t *ppos)
{
	char *data;
	ssize_t result;

	if (datalen >= PAGE_SIZE)
		datalen = PAGE_SIZE - 1;

	/* No partial writes. */
	result = -EINVAL;
	if (*ppos != 0)
		goto out;

	result = -ENOMEM;
	data = kmalloc(datalen + 1, GFP_KERNEL);
	if (!data)
		goto out;

	*(data + datalen) = '\0';

	result = -EFAULT;
	if (copy_from_user(data, buf, datalen))
		goto out_free;

	result = mutex_lock_interruptible(&ima_write_mutex);
	if (result < 0)
		goto out_free;

	if (data[0] == '/') {
		result = ima_read_policy(data);
	} else if (ima_appraise & IMA_APPRAISE_POLICY) {
		pr_err("IMA: signed policy file (specified as an absolute pathname) required\n");
		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
				    "policy_update", "signed policy required",
				    1, 0);
		if (ima_appraise & IMA_APPRAISE_ENFORCE)
			result = -EACCES;
	} else {
		result = ima_parse_add_rule(data);
	}
	mutex_unlock(&ima_write_mutex);
out_free:
	kfree(data);
out:
	if (result < 0)
		valid_policy = 0;

	return result;
}

static struct dentry *ima_dir;
static struct dentry *binary_runtime_measurements;
static struct dentry *ascii_runtime_measurements;
static struct dentry *runtime_measurements_count;
static struct dentry *violations;
static struct dentry *ima_policy;

enum ima_fs_flags {
	IMA_FS_BUSY,
};

static unsigned long ima_fs_flags;

#ifdef	CONFIG_IMA_READ_POLICY
static const struct seq_operations ima_policy_seqops = {
		.start = ima_policy_start,
		.next = ima_policy_next,
		.stop = ima_policy_stop,
		.show = ima_policy_show,
};
#endif

/*
 * ima_open_policy: sequentialize access to the policy file
 */
static int ima_open_policy(struct inode *inode, struct file *filp)
{
	if (!(filp->f_flags & O_WRONLY)) {
#ifndef	CONFIG_IMA_READ_POLICY
		return -EACCES;
#else
		if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
			return -EACCES;
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		return seq_open(filp, &ima_policy_seqops);
#endif
	}
	if (test_and_set_bit(IMA_FS_BUSY, &ima_fs_flags))
		return -EBUSY;
	return 0;
}

/*
 * ima_release_policy - start using the new measure policy rules.
 *
 * Initially, ima_measure points to the default policy rules, now
 * point to the new policy rules, and remove the securityfs policy file,
 * assuming a valid policy.
 */
static int ima_release_policy(struct inode *inode, struct file *file)
{
	const char *cause = valid_policy ? "completed" : "failed";

	if ((file->f_flags & O_ACCMODE) == O_RDONLY)
		return 0;

	if (valid_policy && ima_check_policy() < 0) {
		cause = "failed";
		valid_policy = 0;
	}

	pr_info("IMA: policy update %s\n", cause);
	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
			    "policy_update", cause, !valid_policy, 0);

	if (!valid_policy) {
		ima_delete_rules();
		valid_policy = 1;
		clear_bit(IMA_FS_BUSY, &ima_fs_flags);
		return 0;
	}

	ima_update_policy();
#ifndef	CONFIG_IMA_WRITE_POLICY
	securityfs_remove(ima_policy);
	ima_policy = NULL;
#else
	clear_bit(IMA_FS_BUSY, &ima_fs_flags);
#endif
	return 0;
}

static const struct file_operations ima_measure_policy_ops = {
	.open = ima_open_policy,
	.write = ima_write_policy,
	.read = seq_read,
	.release = ima_release_policy,
	.llseek = generic_file_llseek,
};

int __init ima_fs_init(void)
{
	ima_dir = securityfs_create_dir("ima", NULL);
	if (IS_ERR(ima_dir))
		return -1;

	binary_runtime_measurements =
	    securityfs_create_file("binary_runtime_measurements",
				   S_IRUSR | S_IRGRP, ima_dir, NULL,
				   &ima_measurements_ops);
	if (IS_ERR(binary_runtime_measurements))
		goto out;

	ascii_runtime_measurements =
	    securityfs_create_file("ascii_runtime_measurements",
				   S_IRUSR | S_IRGRP, ima_dir, NULL,
				   &ima_ascii_measurements_ops);
	if (IS_ERR(ascii_runtime_measurements))
		goto out;

	runtime_measurements_count =
	    securityfs_create_file("runtime_measurements_count",
				   S_IRUSR | S_IRGRP, ima_dir, NULL,
				   &ima_measurements_count_ops);
	if (IS_ERR(runtime_measurements_count))
		goto out;

	violations =
	    securityfs_create_file("violations", S_IRUSR | S_IRGRP,
				   ima_dir, NULL, &ima_htable_violations_ops);
	if (IS_ERR(violations))
		goto out;

	ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS,
					    ima_dir, NULL,
					    &ima_measure_policy_ops);
	if (IS_ERR(ima_policy))
		goto out;

	return 0;
out:
	securityfs_remove(violations);
	securityfs_remove(runtime_measurements_count);
	securityfs_remove(ascii_runtime_measurements);
	securityfs_remove(binary_runtime_measurements);
	securityfs_remove(ima_dir);
	securityfs_remove(ima_policy);
	return -1;
}
Commit	Line	Data
bab73937 MZ	1	/*
	2	* Copyright (C) 2005,2006,2007,2008 IBM Corporation
	3	*
	4	* Authors:
	5	* Kylene Hall <kjhall@us.ibm.com>
	6	* Reiner Sailer <sailer@us.ibm.com>
	7	* Mimi Zohar <zohar@us.ibm.com>
	8	*
	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
	12	* License.
	13	*
	14	* File: ima_fs.c
	15	* implemenents security file system for reporting
	16	* current measurement list and IMA statistics
	17	*/
f850a7c0	18	#include <linux/fcntl.h>
5a0e3ad6	19	#include <linux/slab.h>
bab73937 MZ	20	#include <linux/module.h>
	21	#include <linux/seq_file.h>
	22	#include <linux/rculist.h>
	23	#include <linux/rcupdate.h>
4af4662f	24	#include <linux/parser.h>
7429b092	25	#include <linux/vmalloc.h>
bab73937 MZ	26
	27	#include "ima.h"
	28
38d859f9 PM	29	static DEFINE_MUTEX(ima_write_mutex);
38d859f9 PM	30
4af4662f	31	static int valid_policy = 1;
bab73937 MZ	32	#define TMPBUFLEN 12
	33	static ssize_t ima_show_htable_value(char __user *buf, size_t count,
	34	loff_t ppos, atomic_long_t val)
	35	{
	36	char tmpbuf[TMPBUFLEN];
	37	ssize_t len;
	38
	39	len = scnprintf(tmpbuf, TMPBUFLEN, "%li\n", atomic_long_read(val));
	40	return simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
	41	}
	42
	43	static ssize_t ima_show_htable_violations(struct file *filp,
	44	char __user *buf,
	45	size_t count, loff_t *ppos)
	46	{
	47	return ima_show_htable_value(buf, count, ppos, &ima_htable.violations);
	48	}
	49
828c0950	50	static const struct file_operations ima_htable_violations_ops = {
cdcd90f9 AB	51	.read = ima_show_htable_violations,
cdcd90f9 AB	52	.llseek = generic_file_llseek,
bab73937 MZ	53	};
	54
	55	static ssize_t ima_show_measurements_count(struct file *filp,
	56	char __user *buf,
	57	size_t count, loff_t *ppos)
	58	{
	59	return ima_show_htable_value(buf, count, ppos, &ima_htable.len);
	60
	61	}
	62
828c0950	63	static const struct file_operations ima_measurements_count_ops = {
cdcd90f9 AB	64	.read = ima_show_measurements_count,
cdcd90f9 AB	65	.llseek = generic_file_llseek,
bab73937 MZ	66	};
	67
	68	/* returns pointer to hlist_node */
	69	static void ima_measurements_start(struct seq_file m, loff_t *pos)
	70	{
	71	loff_t l = *pos;
	72	struct ima_queue_entry *qe;
	73
	74	/* we need a lock since pos could point beyond last element */
	75	rcu_read_lock();
	76	list_for_each_entry_rcu(qe, &ima_measurements, later) {
	77	if (!l--) {
	78	rcu_read_unlock();
	79	return qe;
	80	}
	81	}
	82	rcu_read_unlock();
	83	return NULL;
	84	}
	85
	86	static void ima_measurements_next(struct seq_file m, void v, loff_t pos)
	87	{
	88	struct ima_queue_entry *qe = v;
	89
	90	/* lock protects when reading beyond last element
	91	* against concurrent list-extension
	92	*/
	93	rcu_read_lock();
089bc8e9	94	qe = list_entry_rcu(qe->later.next, struct ima_queue_entry, later);
bab73937 MZ	95	rcu_read_unlock();
	96	(*pos)++;
	97
	98	return (&qe->later == &ima_measurements) ? NULL : qe;
	99	}
	100
	101	static void ima_measurements_stop(struct seq_file m, void v)
	102	{
	103	}
	104
3ce1217d	105	void ima_putc(struct seq_file m, void data, int datalen)
bab73937 MZ	106	{
	107	while (datalen--)
	108	seq_putc(m, (char )data++);
	109	}
	110
	111	/* print format:
	112	* 32bit-le=pcr#
	113	* char[20]=template digest
	114	* 32bit-le=template name size
	115	* char[n]=template name
a71dc65d	116	* [eventdata length]
bab73937 MZ	117	* eventdata[n]=template specific data
	118	*/
	119	static int ima_measurements_show(struct seq_file m, void v)
	120	{
	121	/* the list never shrinks, so we don't need a lock here */
	122	struct ima_queue_entry *qe = v;
	123	struct ima_template_entry *e;
7dbdb420	124	char *template_name;
bab73937 MZ	125	int namelen;
bab73937 MZ	126	u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
3e8e5503	127	bool is_ima_template = false;
a71dc65d	128	int i;
bab73937 MZ	129
	130	/* get entry */
	131	e = qe->entry;
	132	if (e == NULL)
	133	return -1;
	134
7dbdb420 RS	135	template_name = (e->template_desc->name[0] != '\0') ?
	136	e->template_desc->name : e->template_desc->fmt;
	137
bab73937 MZ	138	/*
	139	* 1st: PCRIndex
	140	* PCR used is always the same (config option) in
	141	* little-endian format
	142	*/
2bb930ab	143	ima_putc(m, &pcr, sizeof(pcr));
bab73937 MZ	144
bab73937 MZ	145	/* 2nd: template digest */
140d8022	146	ima_putc(m, e->digest, TPM_DIGEST_SIZE);
bab73937 MZ	147
bab73937 MZ	148	/* 3rd: template name size */
7dbdb420	149	namelen = strlen(template_name);
2bb930ab	150	ima_putc(m, &namelen, sizeof(namelen));
bab73937 MZ	151
bab73937 MZ	152	/* 4th: template name */
7dbdb420	153	ima_putc(m, template_name, namelen);
a71dc65d RS	154
a71dc65d RS	155	/* 5th: template length (except for 'ima' template) */
7dbdb420	156	if (strcmp(template_name, IMA_TEMPLATE_IMA_NAME) == 0)
3e8e5503 RS	157	is_ima_template = true;
	158
	159	if (!is_ima_template)
a71dc65d RS	160	ima_putc(m, &e->template_data_len,
a71dc65d RS	161	sizeof(e->template_data_len));
bab73937	162
a71dc65d RS	163	/* 6th: template specific data */
a71dc65d RS	164	for (i = 0; i < e->template_desc->num_fields; i++) {
3e8e5503 RS	165	enum ima_show_type show = IMA_SHOW_BINARY;
	166	struct ima_template_field *field = e->template_desc->fields[i];
	167
	168	if (is_ima_template && strcmp(field->field_id, "d") == 0)
	169	show = IMA_SHOW_BINARY_NO_FIELD_LEN;
c019e307 RS	170	if (is_ima_template && strcmp(field->field_id, "n") == 0)
c019e307 RS	171	show = IMA_SHOW_BINARY_OLD_STRING_FMT;
3e8e5503	172	field->field_show(m, show, &e->template_data[i]);
a71dc65d	173	}
bab73937 MZ	174	return 0;
	175	}
	176
88e9d34c	177	static const struct seq_operations ima_measurments_seqops = {
bab73937 MZ	178	.start = ima_measurements_start,
	179	.next = ima_measurements_next,
	180	.stop = ima_measurements_stop,
	181	.show = ima_measurements_show
	182	};
	183
	184	static int ima_measurements_open(struct inode inode, struct file file)
	185	{
	186	return seq_open(file, &ima_measurments_seqops);
	187	}
	188
828c0950	189	static const struct file_operations ima_measurements_ops = {
bab73937 MZ	190	.open = ima_measurements_open,
	191	.read = seq_read,
	192	.llseek = seq_lseek,
	193	.release = seq_release,
	194	};
	195
45b26133	196	void ima_print_digest(struct seq_file m, u8 digest, u32 size)
bab73937	197	{
45b26133	198	u32 i;
bab73937	199
140d8022	200	for (i = 0; i < size; i++)
bab73937 MZ	201	seq_printf(m, "%02x", *(digest + i));
	202	}
	203
bab73937 MZ	204	/* print in ascii */
	205	static int ima_ascii_measurements_show(struct seq_file m, void v)
	206	{
	207	/* the list never shrinks, so we don't need a lock here */
	208	struct ima_queue_entry *qe = v;
	209	struct ima_template_entry *e;
7dbdb420	210	char *template_name;
a71dc65d	211	int i;
bab73937 MZ	212
	213	/* get entry */
	214	e = qe->entry;
	215	if (e == NULL)
	216	return -1;
	217
7dbdb420 RS	218	template_name = (e->template_desc->name[0] != '\0') ?
	219	e->template_desc->name : e->template_desc->fmt;
	220
bab73937 MZ	221	/* 1st: PCR used (config option) */
	222	seq_printf(m, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX);
	223
	224	/* 2nd: SHA1 template hash */
140d8022	225	ima_print_digest(m, e->digest, TPM_DIGEST_SIZE);
bab73937 MZ	226
bab73937 MZ	227	/* 3th: template name */
7dbdb420	228	seq_printf(m, " %s", template_name);
bab73937 MZ	229
bab73937 MZ	230	/* 4th: template specific data */
a71dc65d RS	231	for (i = 0; i < e->template_desc->num_fields; i++) {
	232	seq_puts(m, " ");
	233	if (e->template_data[i].len == 0)
	234	continue;
	235
	236	e->template_desc->fields[i]->field_show(m, IMA_SHOW_ASCII,
	237	&e->template_data[i]);
	238	}
	239	seq_puts(m, "\n");
bab73937 MZ	240	return 0;
	241	}
	242
88e9d34c	243	static const struct seq_operations ima_ascii_measurements_seqops = {
bab73937 MZ	244	.start = ima_measurements_start,
	245	.next = ima_measurements_next,
	246	.stop = ima_measurements_stop,
	247	.show = ima_ascii_measurements_show
	248	};
	249
	250	static int ima_ascii_measurements_open(struct inode inode, struct file file)
	251	{
	252	return seq_open(file, &ima_ascii_measurements_seqops);
	253	}
	254
828c0950	255	static const struct file_operations ima_ascii_measurements_ops = {
bab73937 MZ	256	.open = ima_ascii_measurements_open,
	257	.read = seq_read,
	258	.llseek = seq_lseek,
	259	.release = seq_release,
	260	};
	261
7429b092 DK	262	static ssize_t ima_read_policy(char *path)
	263	{
	264	void *data;
	265	char *datap;
	266	loff_t size;
	267	int rc, pathlen = strlen(path);
	268
	269	char *p;
	270
	271	/* remove \n */
	272	datap = path;
	273	strsep(&datap, "\n");
	274
	275	rc = kernel_read_file_from_path(path, &data, &size, 0, READING_POLICY);
	276	if (rc < 0) {
	277	pr_err("Unable to open file: %s (%d)", path, rc);
	278	return rc;
	279	}
	280
	281	datap = data;
	282	while (size > 0 && (p = strsep(&datap, "\n"))) {
	283	pr_debug("rule: %s\n", p);
	284	rc = ima_parse_add_rule(p);
	285	if (rc < 0)
	286	break;
	287	size -= rc;
	288	}
	289
	290	vfree(data);
	291	if (rc < 0)
	292	return rc;
	293	else if (size)
	294	return -EINVAL;
	295	else
	296	return pathlen;
	297	}
	298
4af4662f MZ	299	static ssize_t ima_write_policy(struct file file, const char __user buf,
	300	size_t datalen, loff_t *ppos)
	301	{
6427e6c7	302	char *data;
6ccd0456	303	ssize_t result;
4af4662f MZ	304
4af4662f MZ	305	if (datalen >= PAGE_SIZE)
6ccd0456 EP	306	datalen = PAGE_SIZE - 1;
	307
	308	/* No partial writes. */
	309	result = -EINVAL;
	310	if (*ppos != 0)
	311	goto out;
	312
	313	result = -ENOMEM;
4af4662f MZ	314	data = kmalloc(datalen + 1, GFP_KERNEL);
4af4662f MZ	315	if (!data)
6ccd0456	316	goto out;
4af4662f	317
4af4662f	318	*(data + datalen) = '\0';
4af4662f	319
6ccd0456 EP	320	result = -EFAULT;
6ccd0456 EP	321	if (copy_from_user(data, buf, datalen))
6427e6c7	322	goto out_free;
6ccd0456	323
6427e6c7 PM	324	result = mutex_lock_interruptible(&ima_write_mutex);
	325	if (result < 0)
	326	goto out_free;
6427e6c7	327
19f8a847	328	if (data[0] == '/') {
7429b092	329	result = ima_read_policy(data);
19f8a847 MZ	330	} else if (ima_appraise & IMA_APPRAISE_POLICY) {
	331	pr_err("IMA: signed policy file (specified as an absolute pathname) required\n");
	332	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
	333	"policy_update", "signed policy required",
	334	1, 0);
	335	if (ima_appraise & IMA_APPRAISE_ENFORCE)
	336	result = -EACCES;
	337	} else {
7429b092	338	result = ima_parse_add_rule(data);
19f8a847	339	}
7429b092	340	mutex_unlock(&ima_write_mutex);
6427e6c7 PM	341	out_free:
6427e6c7 PM	342	kfree(data);
6ccd0456 EP	343	out:
	344	if (result < 0)
	345	valid_policy = 0;
38d859f9	346
6ccd0456	347	return result;
4af4662f MZ	348	}
4af4662f MZ	349
bab73937 MZ	350	static struct dentry *ima_dir;
	351	static struct dentry *binary_runtime_measurements;
	352	static struct dentry *ascii_runtime_measurements;
	353	static struct dentry *runtime_measurements_count;
	354	static struct dentry *violations;
4af4662f MZ	355	static struct dentry *ima_policy;
4af4662f MZ	356
0716abbb DK	357	enum ima_fs_flags {
	358	IMA_FS_BUSY,
	359	};
	360
	361	static unsigned long ima_fs_flags;
	362
80eae209 PM	363	#ifdef CONFIG_IMA_READ_POLICY
	364	static const struct seq_operations ima_policy_seqops = {
	365	.start = ima_policy_start,
	366	.next = ima_policy_next,
	367	.stop = ima_policy_stop,
	368	.show = ima_policy_show,
	369	};
	370	#endif
	371
f4bd857b MZ	372	/*
	373	* ima_open_policy: sequentialize access to the policy file
	374	*/
2bb930ab	375	static int ima_open_policy(struct inode inode, struct file filp)
f4bd857b	376	{
80eae209 PM	377	if (!(filp->f_flags & O_WRONLY)) {
80eae209 PM	378	#ifndef CONFIG_IMA_READ_POLICY
f850a7c0	379	return -EACCES;
80eae209 PM	380	#else
	381	if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
	382	return -EACCES;
	383	if (!capable(CAP_SYS_ADMIN))
	384	return -EPERM;
	385	return seq_open(filp, &ima_policy_seqops);
	386	#endif
	387	}
0716abbb DK	388	if (test_and_set_bit(IMA_FS_BUSY, &ima_fs_flags))
	389	return -EBUSY;
	390	return 0;
f4bd857b MZ	391	}
f4bd857b MZ	392
4af4662f MZ	393	/*
	394	* ima_release_policy - start using the new measure policy rules.
	395	*
	396	* Initially, ima_measure points to the default policy rules, now
f4bd857b MZ	397	* point to the new policy rules, and remove the securityfs policy file,
f4bd857b MZ	398	* assuming a valid policy.
4af4662f MZ	399	*/
	400	static int ima_release_policy(struct inode inode, struct file file)
	401	{
0716abbb DK	402	const char *cause = valid_policy ? "completed" : "failed";
0716abbb DK	403
80eae209 PM	404	if ((file->f_flags & O_ACCMODE) == O_RDONLY)
	405	return 0;
	406
0112721d SL	407	if (valid_policy && ima_check_policy() < 0) {
	408	cause = "failed";
	409	valid_policy = 0;
	410	}
	411
0716abbb DK	412	pr_info("IMA: policy update %s\n", cause);
	413	integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
	414	"policy_update", cause, !valid_policy, 0);
	415
4af4662f MZ	416	if (!valid_policy) {
4af4662f MZ	417	ima_delete_rules();
f4bd857b	418	valid_policy = 1;
0716abbb	419	clear_bit(IMA_FS_BUSY, &ima_fs_flags);
4af4662f MZ	420	return 0;
4af4662f MZ	421	}
80eae209	422
4af4662f	423	ima_update_policy();
38d859f9	424	#ifndef CONFIG_IMA_WRITE_POLICY
4af4662f MZ	425	securityfs_remove(ima_policy);
4af4662f MZ	426	ima_policy = NULL;
38d859f9 PM	427	#else
	428	clear_bit(IMA_FS_BUSY, &ima_fs_flags);
	429	#endif
4af4662f MZ	430	return 0;
	431	}
	432
828c0950	433	static const struct file_operations ima_measure_policy_ops = {
f4bd857b	434	.open = ima_open_policy,
4af4662f	435	.write = ima_write_policy,
80eae209	436	.read = seq_read,
cdcd90f9 AB	437	.release = ima_release_policy,
cdcd90f9 AB	438	.llseek = generic_file_llseek,
4af4662f	439	};
bab73937	440
932995f0	441	int __init ima_fs_init(void)
bab73937 MZ	442	{
	443	ima_dir = securityfs_create_dir("ima", NULL);
	444	if (IS_ERR(ima_dir))
	445	return -1;
	446
	447	binary_runtime_measurements =
	448	securityfs_create_file("binary_runtime_measurements",
	449	S_IRUSR \| S_IRGRP, ima_dir, NULL,
	450	&ima_measurements_ops);
	451	if (IS_ERR(binary_runtime_measurements))
	452	goto out;
	453
	454	ascii_runtime_measurements =
	455	securityfs_create_file("ascii_runtime_measurements",
	456	S_IRUSR \| S_IRGRP, ima_dir, NULL,
	457	&ima_ascii_measurements_ops);
	458	if (IS_ERR(ascii_runtime_measurements))
	459	goto out;
	460
	461	runtime_measurements_count =
	462	securityfs_create_file("runtime_measurements_count",
	463	S_IRUSR \| S_IRGRP, ima_dir, NULL,
	464	&ima_measurements_count_ops);
	465	if (IS_ERR(runtime_measurements_count))
	466	goto out;
	467
	468	violations =
	469	securityfs_create_file("violations", S_IRUSR \| S_IRGRP,
	470	ima_dir, NULL, &ima_htable_violations_ops);
	471	if (IS_ERR(violations))
	472	goto out;
	473
80eae209	474	ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS,
4af4662f MZ	475	ima_dir, NULL,
	476	&ima_measure_policy_ops);
	477	if (IS_ERR(ima_policy))
	478	goto out;
bab73937	479
4af4662f	480	return 0;
bab73937	481	out:
0ea4f8ae	482	securityfs_remove(violations);
bab73937 MZ	483	securityfs_remove(runtime_measurements_count);
	484	securityfs_remove(ascii_runtime_measurements);
	485	securityfs_remove(binary_runtime_measurements);
	486	securityfs_remove(ima_dir);
4af4662f	487	securityfs_remove(ima_policy);
bab73937 MZ	488	return -1;
bab73937 MZ	489	}