[PATCH 3/8] integrity: IMA display

Mimi Zohar
2009-02-06T19:59:46Z

Make the measurement lists available through securityfs.
- removed test for NULL return code from securityfs_create_file/dir

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
---
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index 9d6bf97..787c4cb 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -5,5 +5,5 @@

obj-$(CONFIG_IMA) += ima.o

-ima-y := ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
+ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
ima_policy.o ima_iint.o ima_audit.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index bfa72ed..9c280cc 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -67,6 +67,9 @@ void integrity_audit_msg(int audit_msgno, struct inode *inode,
/* Internal IMA function definitions */
void ima_iintcache_init(void);
int ima_init(void);
+void ima_cleanup(void);
+int ima_fs_init(void);
+void ima_fs_cleanup(void);
int ima_add_template_entry(struct ima_template_entry *entry, int violation,
const char *op, struct inode *inode);
int ima_calc_hash(struct file *file, char *digest);
@@ -115,6 +118,8 @@ void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
const unsigned char *filename);
int ima_store_template(struct ima_template_entry *entry, int violation,
struct inode *inode);
+void ima_template_show(struct seq_file *m, void *e,
+ enum ima_show_type show);

/* radix tree calls to lookup, insert, delete
* integrity data associated with an inode.
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
new file mode 100644
index 0000000..4f25be7
--- /dev/null
+++ b/security/integrity/ima/ima_fs.c
@@ -0,0 +1,296 @@
+/*
+ * 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/module.h>
+#include <linux/seq_file.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+
+#include "ima.h"
+
+#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 struct file_operations ima_htable_violations_ops = {
+ .read = ima_show_htable_violations
+};
+
+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 struct file_operations ima_measurements_count_ops = {
+ .read = ima_show_measurements_count
+};
+
+/* 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_dereference(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)
+{
+}
+
+static 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[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;
+ int namelen;
+ u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
+
+ /* get entry */
+ e = qe->entry;
+ if (e == NULL)
+ return -1;
+
+ /*
+ * 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, IMA_DIGEST_SIZE);
+
+ /* 3rd: template name size */
+ namelen = strlen(e->template_name);
+ ima_putc(m, &namelen, sizeof namelen);
+
+ /* 4th: template name */
+ ima_putc(m, e->template_name, namelen);
+
+ /* 5th: template specific data */
+ ima_template_show(m, (struct ima_template_data *)&e->template,
+ IMA_SHOW_BINARY);
+ return 0;
+}
+
+static 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 struct file_operations ima_measurements_ops = {
+ .open = ima_measurements_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static void ima_print_digest(struct seq_file *m, u8 *digest)
+{
+ int i;
+
+ for (i = 0; i < IMA_DIGEST_SIZE; i++)
+ seq_printf(m, "%02x", *(digest + i));
+}
+
+void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show)
+{
+ struct ima_template_data *entry = e;
+ int namelen;
+
+ switch (show) {
+ case IMA_SHOW_ASCII:
+ ima_print_digest(m, entry->digest);
+ seq_printf(m, " %s\n", entry->file_name);
+ break;
+ case IMA_SHOW_BINARY:
+ ima_putc(m, entry->digest, IMA_DIGEST_SIZE);
+
+ namelen = strlen(entry->file_name);
+ ima_putc(m, &namelen, sizeof namelen);
+ ima_putc(m, entry->file_name, namelen);
+ default:
+ break;
+ }
+}
+
+/* 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;
+
+ /* get entry */
+ e = qe->entry;
+ if (e == NULL)
+ return -1;
+
+ /* 1st: PCR used (config option) */
+ seq_printf(m, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX);
+
+ /* 2nd: SHA1 template hash */
+ ima_print_digest(m, e->digest);
+
+ /* 3th: template name */
+ seq_printf(m, " %s ", e->template_name);
+
+ /* 4th: template specific data */
+ ima_template_show(m, (struct ima_template_data *)&e->template,
+ IMA_SHOW_ASCII);
+ return 0;
+}
+
+static 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 struct file_operations ima_ascii_measurements_ops = {
+ .open = ima_ascii_measurements_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+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;
+
+int 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;
+
+ return 0;
+
+out:
+ securityfs_remove(runtime_measurements_count);
+ securityfs_remove(ascii_runtime_measurements);
+ securityfs_remove(binary_runtime_measurements);
+ securityfs_remove(ima_dir);
+ return -1;
+}
+
+void __exit ima_fs_cleanup(void)
+{
+ securityfs_remove(violations);
+ securityfs_remove(runtime_measurements_count);
+ securityfs_remove(ascii_runtime_measurements);
+ securityfs_remove(binary_runtime_measurements);
+ securityfs_remove(ima_dir);
+}
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index e0f02e3..cf227db 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -86,5 +86,11 @@ int ima_init(void)

ima_add_boot_aggregate(); /* boot aggregate must be first entry */
ima_init_policy();
- return 0;
+
+ return ima_fs_init();
+}
+
+void __exit ima_cleanup(void)
+{
+ ima_fs_cleanup();
}
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 53cee4c..871e356 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -274,6 +274,11 @@ static int __init init_ima(void)
return error;
}

+static void __exit cleanup_ima(void)
+{
+ ima_cleanup();
+}
+
late_initcall(init_ima); /* Start IMA after the TPM is available */

MODULE_DESCRIPTION("Integrity Measurement Architecture");
--
1.5.6.6