linux/drivers/char/tpm/tpm-sysfs.c

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/*
* Copyright (C) 2004 IBM Corporation
* Authors:
* Leendert van Doorn <leendert@watson.ibm.com>
* Dave Safford <safford@watson.ibm.com>
* Reiner Sailer <sailer@watson.ibm.com>
* Kylene Hall <kjhall@us.ibm.com>
*
* Copyright (C) 2013 Obsidian Research Corp
* Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
*
* sysfs filesystem inspection interface to the TPM
*
* 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.
*
*/
#include <linux/device.h>
#include "tpm.h"
/* XXX for now this helper is duplicated in tpm-interface.c */
static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
int len, const char *desc)
{
int err;
len = tpm_transmit(chip, (u8 *) cmd, len);
if (len < 0)
return len;
else if (len < TPM_HEADER_SIZE)
return -EFAULT;
err = be32_to_cpu(cmd->header.out.return_code);
if (err != 0 && desc)
dev_err(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
return err;
}
#define READ_PUBEK_RESULT_SIZE 314
#define TPM_ORD_READPUBEK cpu_to_be32(124)
static struct tpm_input_header tpm_readpubek_header = {
.tag = TPM_TAG_RQU_COMMAND,
.length = cpu_to_be32(30),
.ordinal = TPM_ORD_READPUBEK
};
static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
u8 *data;
struct tpm_cmd_t tpm_cmd;
ssize_t err;
int i, rc;
char *str = buf;
struct tpm_chip *chip = dev_get_drvdata(dev);
tpm_cmd.header.in = tpm_readpubek_header;
err = transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
"attempting to read the PUBEK");
if (err)
goto out;
/*
ignore header 10 bytes
algorithm 32 bits (1 == RSA )
encscheme 16 bits
sigscheme 16 bits
parameters (RSA 12->bytes: keybit, #primes, expbit)
keylenbytes 32 bits
256 byte modulus
ignore checksum 20 bytes
*/
data = tpm_cmd.params.readpubek_out_buffer;
str +=
sprintf(str,
"Algorithm: %02X %02X %02X %02X\n"
"Encscheme: %02X %02X\n"
"Sigscheme: %02X %02X\n"
"Parameters: %02X %02X %02X %02X "
"%02X %02X %02X %02X "
"%02X %02X %02X %02X\n"
"Modulus length: %d\n"
"Modulus:\n",
data[0], data[1], data[2], data[3],
data[4], data[5],
data[6], data[7],
data[12], data[13], data[14], data[15],
data[16], data[17], data[18], data[19],
data[20], data[21], data[22], data[23],
be32_to_cpu(*((__be32 *) (data + 24))));
for (i = 0; i < 256; i++) {
str += sprintf(str, "%02X ", data[i + 28]);
if ((i + 1) % 16 == 0)
str += sprintf(str, "\n");
}
out:
rc = str - buf;
return rc;
}
static DEVICE_ATTR_RO(pubek);
static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
cap_t cap;
u8 digest[TPM_DIGEST_SIZE];
ssize_t rc;
int i, j, num_pcrs;
char *str = buf;
struct tpm_chip *chip = dev_get_drvdata(dev);
rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
"attempting to determine the number of PCRS");
if (rc)
return 0;
num_pcrs = be32_to_cpu(cap.num_pcrs);
for (i = 0; i < num_pcrs; i++) {
rc = tpm_pcr_read_dev(chip, i, digest);
if (rc)
break;
str += sprintf(str, "PCR-%02d: ", i);
for (j = 0; j < TPM_DIGEST_SIZE; j++)
str += sprintf(str, "%02X ", digest[j]);
str += sprintf(str, "\n");
}
return str - buf;
}
static DEVICE_ATTR_RO(pcrs);
static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
cap_t cap;
ssize_t rc;
rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
"attempting to determine the permanent enabled state");
if (rc)
return 0;
rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
return rc;
}
static DEVICE_ATTR_RO(enabled);
ssize_t active_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
cap_t cap;
ssize_t rc;
rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
"attempting to determine the permanent active state");
if (rc)
return 0;
rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
return rc;
}
static DEVICE_ATTR_RO(active);
static ssize_t owned_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
cap_t cap;
ssize_t rc;
rc = tpm_getcap(dev, TPM_CAP_PROP_OWNER, &cap,
"attempting to determine the owner state");
if (rc)
return 0;
rc = sprintf(buf, "%d\n", cap.owned);
return rc;
}
static DEVICE_ATTR_RO(owned);
static ssize_t temp_deactivated_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
cap_t cap;
ssize_t rc;
rc = tpm_getcap(dev, TPM_CAP_FLAG_VOL, &cap,
"attempting to determine the temporary state");
if (rc)
return 0;
rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
return rc;
}
static DEVICE_ATTR_RO(temp_deactivated);
static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
cap_t cap;
ssize_t rc;
char *str = buf;
rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
"attempting to determine the manufacturer");
if (rc)
return 0;
str += sprintf(str, "Manufacturer: 0x%x\n",
be32_to_cpu(cap.manufacturer_id));
/* Try to get a TPM version 1.2 TPM_CAP_VERSION_INFO */
rc = tpm_getcap(dev, CAP_VERSION_1_2, &cap,
"attempting to determine the 1.2 version");
if (!rc) {
str += sprintf(str,
"TCG version: %d.%d\nFirmware version: %d.%d\n",
cap.tpm_version_1_2.Major,
cap.tpm_version_1_2.Minor,
cap.tpm_version_1_2.revMajor,
cap.tpm_version_1_2.revMinor);
} else {
/* Otherwise just use TPM_STRUCT_VER */
rc = tpm_getcap(dev, CAP_VERSION_1_1, &cap,
"attempting to determine the 1.1 version");
if (rc)
return 0;
str += sprintf(str,
"TCG version: %d.%d\nFirmware version: %d.%d\n",
cap.tpm_version.Major,
cap.tpm_version.Minor,
cap.tpm_version.revMajor,
cap.tpm_version.revMinor);
}
return str - buf;
}
static DEVICE_ATTR_RO(caps);
static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
if (chip == NULL)
return 0;
chip->ops->cancel(chip);
return count;
}
static DEVICE_ATTR_WO(cancel);
static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
if (chip->vendor.duration[TPM_LONG] == 0)
return 0;
return sprintf(buf, "%d %d %d [%s]\n",
jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
jiffies_to_usecs(chip->vendor.duration[TPM_LONG]),
chip->vendor.duration_adjusted
? "adjusted" : "original");
}
static DEVICE_ATTR_RO(durations);
static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
return sprintf(buf, "%d %d %d %d [%s]\n",
jiffies_to_usecs(chip->vendor.timeout_a),
jiffies_to_usecs(chip->vendor.timeout_b),
jiffies_to_usecs(chip->vendor.timeout_c),
jiffies_to_usecs(chip->vendor.timeout_d),
chip->vendor.timeout_adjusted
? "adjusted" : "original");
}
static DEVICE_ATTR_RO(timeouts);
static struct attribute *tpm_dev_attrs[] = {
&dev_attr_pubek.attr,
&dev_attr_pcrs.attr,
&dev_attr_enabled.attr,
&dev_attr_active.attr,
&dev_attr_owned.attr,
&dev_attr_temp_deactivated.attr,
&dev_attr_caps.attr,
&dev_attr_cancel.attr,
&dev_attr_durations.attr,
&dev_attr_timeouts.attr,
NULL,
};
static const struct attribute_group tpm_dev_group = {
.attrs = tpm_dev_attrs,
};
int tpm_sysfs_add_device(struct tpm_chip *chip)
{
int err;
err = sysfs_create_group(&chip->dev->kobj,
&tpm_dev_group);
if (err)
dev_err(chip->dev,
"failed to create sysfs attributes, %d\n", err);
return err;
}
void tpm_sysfs_del_device(struct tpm_chip *chip)
{
sysfs_remove_group(&chip->dev->kobj, &tpm_dev_group);
}