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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/drivers/char/tpm/tpm.c

607 строки
14 KiB
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>
*
* Maintained by: <tpmdd_devel@lists.sourceforge.net>
*
* Device driver for TCG/TCPA TPM (trusted platform module).
* Specifications at www.trustedcomputinggroup.org
*
* 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.
*
* Note, the TPM chip is not interrupt driven (only polling)
* and can have very long timeouts (minutes!). Hence the unusual
* calls to msleep.
*
*/
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
#include "tpm.h"
enum tpm_const {
TPM_MINOR = 224, /* officially assigned */
TPM_BUFSIZE = 2048,
TPM_NUM_DEVICES = 256,
TPM_NUM_MASK_ENTRIES = TPM_NUM_DEVICES / (8 * sizeof(int))
};
static LIST_HEAD(tpm_chip_list);
static DEFINE_SPINLOCK(driver_lock);
static int dev_mask[TPM_NUM_MASK_ENTRIES];
static void user_reader_timeout(unsigned long ptr)
{
struct tpm_chip *chip = (struct tpm_chip *) ptr;
schedule_work(&chip->work);
}
static void timeout_work(void * ptr)
{
struct tpm_chip *chip = ptr;
down(&chip->buffer_mutex);
atomic_set(&chip->data_pending, 0);
memset(chip->data_buffer, 0, TPM_BUFSIZE);
up(&chip->buffer_mutex);
}
/*
* Internal kernel interface to transmit TPM commands
*/
static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
size_t bufsiz)
{
ssize_t rc;
u32 count;
unsigned long stop;
count = be32_to_cpu(*((__be32 *) (buf + 2)));
if (count == 0)
return -ENODATA;
if (count > bufsiz) {
dev_err(chip->dev,
"invalid count value %x %zx \n", count, bufsiz);
return -E2BIG;
}
down(&chip->tpm_mutex);
if ((rc = chip->vendor->send(chip, (u8 *) buf, count)) < 0) {
dev_err(chip->dev,
"tpm_transmit: tpm_send: error %zd\n", rc);
goto out;
}
stop = jiffies + 2 * 60 * HZ;
do {
u8 status = chip->vendor->status(chip);
if ((status & chip->vendor->req_complete_mask) ==
chip->vendor->req_complete_val) {
goto out_recv;
}
if ((status == chip->vendor->req_canceled)) {
dev_err(chip->dev, "Operation Canceled\n");
rc = -ECANCELED;
goto out;
}
msleep(TPM_TIMEOUT); /* CHECK */
rmb();
} while (time_before(jiffies, stop));
chip->vendor->cancel(chip);
dev_err(chip->dev, "Operation Timed out\n");
rc = -ETIME;
goto out;
out_recv:
rc = chip->vendor->recv(chip, (u8 *) buf, bufsiz);
if (rc < 0)
dev_err(chip->dev,
"tpm_transmit: tpm_recv: error %zd\n", rc);
out:
up(&chip->tpm_mutex);
return rc;
}
#define TPM_DIGEST_SIZE 20
#define CAP_PCR_RESULT_SIZE 18
static const u8 cap_pcr[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
0, 0, 0, 22, /* length */
0, 0, 0, 101, /* TPM_ORD_GetCapability */
0, 0, 0, 5,
0, 0, 0, 4,
0, 0, 1, 1
};
#define READ_PCR_RESULT_SIZE 30
static const u8 pcrread[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
0, 0, 0, 14, /* length */
0, 0, 0, 21, /* TPM_ORD_PcrRead */
0, 0, 0, 0 /* PCR index */
};
ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
char *buf)
{
u8 data[READ_PCR_RESULT_SIZE];
ssize_t len;
int i, j, num_pcrs;
__be32 index;
char *str = buf;
struct tpm_chip *chip = dev_get_drvdata(dev);
if (chip == NULL)
return -ENODEV;
memcpy(data, cap_pcr, sizeof(cap_pcr));
if ((len = tpm_transmit(chip, data, sizeof(data)))
< CAP_PCR_RESULT_SIZE) {
dev_dbg(chip->dev, "A TPM error (%d) occurred "
"attempting to determine the number of PCRS\n",
be32_to_cpu(*((__be32 *) (data + 6))));
return 0;
}
num_pcrs = be32_to_cpu(*((__be32 *) (data + 14)));
for (i = 0; i < num_pcrs; i++) {
memcpy(data, pcrread, sizeof(pcrread));
index = cpu_to_be32(i);
memcpy(data + 10, &index, 4);
if ((len = tpm_transmit(chip, data, sizeof(data)))
< READ_PCR_RESULT_SIZE){
dev_dbg(chip->dev, "A TPM error (%d) occurred"
" attempting to read PCR %d of %d\n",
be32_to_cpu(*((__be32 *) (data + 6))),
i, num_pcrs);
goto out;
}
str += sprintf(str, "PCR-%02d: ", i);
for (j = 0; j < TPM_DIGEST_SIZE; j++)
str += sprintf(str, "%02X ", *(data + 10 + j));
str += sprintf(str, "\n");
}
out:
return str - buf;
}
EXPORT_SYMBOL_GPL(tpm_show_pcrs);
#define READ_PUBEK_RESULT_SIZE 314
static const u8 readpubek[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
0, 0, 0, 30, /* length */
0, 0, 0, 124, /* TPM_ORD_ReadPubek */
};
ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
char *buf)
{
u8 *data;
ssize_t len;
int i, rc;
char *str = buf;
struct tpm_chip *chip = dev_get_drvdata(dev);
if (chip == NULL)
return -ENODEV;
data = kzalloc(READ_PUBEK_RESULT_SIZE, GFP_KERNEL);
if (!data)
return -ENOMEM;
memcpy(data, readpubek, sizeof(readpubek));
if ((len = tpm_transmit(chip, data, READ_PUBEK_RESULT_SIZE)) <
READ_PUBEK_RESULT_SIZE) {
dev_dbg(chip->dev, "A TPM error (%d) occurred "
"attempting to read the PUBEK\n",
be32_to_cpu(*((__be32 *) (data + 6))));
rc = 0;
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
*/
str +=
sprintf(str,
"Algorithm: %02X %02X %02X %02X\nEncscheme: %02X %02X\n"
"Sigscheme: %02X %02X\nParameters: %02X %02X %02X %02X"
" %02X %02X %02X %02X %02X %02X %02X %02X\n"
"Modulus length: %d\nModulus: \n",
data[10], data[11], data[12], data[13], data[14],
data[15], data[16], data[17], data[22], data[23],
data[24], data[25], data[26], data[27], data[28],
data[29], data[30], data[31], data[32], data[33],
be32_to_cpu(*((__be32 *) (data + 34))));
for (i = 0; i < 256; i++) {
str += sprintf(str, "%02X ", data[i + 38]);
if ((i + 1) % 16 == 0)
str += sprintf(str, "\n");
}
rc = str - buf;
out:
kfree(data);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_show_pubek);
#define CAP_VER_RESULT_SIZE 18
static const u8 cap_version[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
0, 0, 0, 18, /* length */
0, 0, 0, 101, /* TPM_ORD_GetCapability */
0, 0, 0, 6,
0, 0, 0, 0
};
#define CAP_MANUFACTURER_RESULT_SIZE 18
static const u8 cap_manufacturer[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
0, 0, 0, 22, /* length */
0, 0, 0, 101, /* TPM_ORD_GetCapability */
0, 0, 0, 5,
0, 0, 0, 4,
0, 0, 1, 3
};
ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
char *buf)
{
u8 data[sizeof(cap_manufacturer)];
ssize_t len;
char *str = buf;
struct tpm_chip *chip = dev_get_drvdata(dev);
if (chip == NULL)
return -ENODEV;
memcpy(data, cap_manufacturer, sizeof(cap_manufacturer));
if ((len = tpm_transmit(chip, data, sizeof(data))) <
CAP_MANUFACTURER_RESULT_SIZE)
return len;
str += sprintf(str, "Manufacturer: 0x%x\n",
be32_to_cpu(*((__be32 *) (data + 14))));
memcpy(data, cap_version, sizeof(cap_version));
if ((len = tpm_transmit(chip, data, sizeof(data))) <
CAP_VER_RESULT_SIZE)
return len;
str +=
sprintf(str, "TCG version: %d.%d\nFirmware version: %d.%d\n",
(int) data[14], (int) data[15], (int) data[16],
(int) data[17]);
return str - buf;
}
EXPORT_SYMBOL_GPL(tpm_show_caps);
ssize_t tpm_store_cancel(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->vendor->cancel(chip);
return count;
}
EXPORT_SYMBOL_GPL(tpm_store_cancel);
/*
* Device file system interface to the TPM
*/
int tpm_open(struct inode *inode, struct file *file)
{
int rc = 0, minor = iminor(inode);
struct tpm_chip *chip = NULL, *pos;
spin_lock(&driver_lock);
list_for_each_entry(pos, &tpm_chip_list, list) {
if (pos->vendor->miscdev.minor == minor) {
chip = pos;
break;
}
}
if (chip == NULL) {
rc = -ENODEV;
goto err_out;
}
if (chip->num_opens) {
dev_dbg(chip->dev, "Another process owns this TPM\n");
rc = -EBUSY;
goto err_out;
}
chip->num_opens++;
get_device(chip->dev);
spin_unlock(&driver_lock);
chip->data_buffer = kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
if (chip->data_buffer == NULL) {
chip->num_opens--;
put_device(chip->dev);
return -ENOMEM;
}
atomic_set(&chip->data_pending, 0);
file->private_data = chip;
return 0;
err_out:
spin_unlock(&driver_lock);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_open);
int tpm_release(struct inode *inode, struct file *file)
{
struct tpm_chip *chip = file->private_data;
spin_lock(&driver_lock);
file->private_data = NULL;
chip->num_opens--;
del_singleshot_timer_sync(&chip->user_read_timer);
flush_scheduled_work();
atomic_set(&chip->data_pending, 0);
put_device(chip->dev);
kfree(chip->data_buffer);
spin_unlock(&driver_lock);
return 0;
}
EXPORT_SYMBOL_GPL(tpm_release);
ssize_t tpm_write(struct file *file, const char __user *buf,
size_t size, loff_t * off)
{
struct tpm_chip *chip = file->private_data;
int in_size = size, out_size;
/* cannot perform a write until the read has cleared
either via tpm_read or a user_read_timer timeout */
while (atomic_read(&chip->data_pending) != 0)
msleep(TPM_TIMEOUT);
down(&chip->buffer_mutex);
if (in_size > TPM_BUFSIZE)
in_size = TPM_BUFSIZE;
if (copy_from_user
(chip->data_buffer, (void __user *) buf, in_size)) {
up(&chip->buffer_mutex);
return -EFAULT;
}
/* atomic tpm command send and result receive */
out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
atomic_set(&chip->data_pending, out_size);
up(&chip->buffer_mutex);
/* Set a timeout by which the reader must come claim the result */
mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
return in_size;
}
EXPORT_SYMBOL_GPL(tpm_write);
ssize_t tpm_read(struct file * file, char __user *buf,
size_t size, loff_t * off)
{
struct tpm_chip *chip = file->private_data;
int ret_size;
del_singleshot_timer_sync(&chip->user_read_timer);
flush_scheduled_work();
ret_size = atomic_read(&chip->data_pending);
atomic_set(&chip->data_pending, 0);
if (ret_size > 0) { /* relay data */
if (size < ret_size)
ret_size = size;
down(&chip->buffer_mutex);
if (copy_to_user(buf, chip->data_buffer, ret_size))
ret_size = -EFAULT;
up(&chip->buffer_mutex);
}
return ret_size;
}
EXPORT_SYMBOL_GPL(tpm_read);
void tpm_remove_hardware(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
if (chip == NULL) {
dev_err(dev, "No device data found\n");
return;
}
spin_lock(&driver_lock);
list_del(&chip->list);
spin_unlock(&driver_lock);
dev_set_drvdata(dev, NULL);
misc_deregister(&chip->vendor->miscdev);
kfree(chip->vendor->miscdev.name);
sysfs_remove_group(&dev->kobj, chip->vendor->attr_group);
tpm_bios_log_teardown(chip->bios_dir);
dev_mask[chip->dev_num / TPM_NUM_MASK_ENTRIES ] &=
~(1 << (chip->dev_num % TPM_NUM_MASK_ENTRIES));
kfree(chip);
put_device(dev);
}
EXPORT_SYMBOL_GPL(tpm_remove_hardware);
static u8 savestate[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
0, 0, 0, 10, /* blob length (in bytes) */
0, 0, 0, 152 /* TPM_ORD_SaveState */
};
/*
* We are about to suspend. Save the TPM state
* so that it can be restored.
*/
int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
if (chip == NULL)
return -ENODEV;
tpm_transmit(chip, savestate, sizeof(savestate));
return 0;
}
EXPORT_SYMBOL_GPL(tpm_pm_suspend);
/*
* Resume from a power safe. The BIOS already restored
* the TPM state.
*/
int tpm_pm_resume(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
if (chip == NULL)
return -ENODEV;
return 0;
}
EXPORT_SYMBOL_GPL(tpm_pm_resume);
/*
* Called from tpm_<specific>.c probe function only for devices
* the driver has determined it should claim. Prior to calling
* this function the specific probe function has called pci_enable_device
* upon errant exit from this function specific probe function should call
* pci_disable_device
*/
int tpm_register_hardware(struct device *dev, struct tpm_vendor_specific *entry)
{
#define DEVNAME_SIZE 7
char *devname;
struct tpm_chip *chip;
int i, j;
/* Driver specific per-device data */
chip = kzalloc(sizeof(*chip), GFP_KERNEL);
if (chip == NULL)
return -ENOMEM;
init_MUTEX(&chip->buffer_mutex);
init_MUTEX(&chip->tpm_mutex);
INIT_LIST_HEAD(&chip->list);
INIT_WORK(&chip->work, timeout_work, chip);
init_timer(&chip->user_read_timer);
chip->user_read_timer.function = user_reader_timeout;
chip->user_read_timer.data = (unsigned long) chip;
chip->vendor = entry;
chip->dev_num = -1;
for (i = 0; i < TPM_NUM_MASK_ENTRIES; i++)
for (j = 0; j < 8 * sizeof(int); j++)
if ((dev_mask[i] & (1 << j)) == 0) {
chip->dev_num =
i * TPM_NUM_MASK_ENTRIES + j;
dev_mask[i] |= 1 << j;
goto dev_num_search_complete;
}
dev_num_search_complete:
if (chip->dev_num < 0) {
dev_err(dev, "No available tpm device numbers\n");
kfree(chip);
return -ENODEV;
} else if (chip->dev_num == 0)
chip->vendor->miscdev.minor = TPM_MINOR;
else
chip->vendor->miscdev.minor = MISC_DYNAMIC_MINOR;
devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
chip->vendor->miscdev.name = devname;
chip->vendor->miscdev.dev = dev;
chip->dev = get_device(dev);
if (misc_register(&chip->vendor->miscdev)) {
dev_err(chip->dev,
"unable to misc_register %s, minor %d\n",
chip->vendor->miscdev.name,
chip->vendor->miscdev.minor);
put_device(dev);
kfree(chip);
dev_mask[i] &= !(1 << j);
return -ENODEV;
}
spin_lock(&driver_lock);
dev_set_drvdata(dev, chip);
list_add(&chip->list, &tpm_chip_list);
spin_unlock(&driver_lock);
sysfs_create_group(&dev->kobj, chip->vendor->attr_group);
chip->bios_dir = tpm_bios_log_setup(devname);
return 0;
}
EXPORT_SYMBOL_GPL(tpm_register_hardware);
MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
MODULE_DESCRIPTION("TPM Driver");
MODULE_VERSION("2.0");
MODULE_LICENSE("GPL");
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