/*
 * 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"

#define READ_PUBEK_RESULT_SIZE 314
#define TPM_ORD_READPUBEK cpu_to_be32(124)
static const 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 = to_tpm_chip(dev);

        tpm_cmd.header.in = tpm_readpubek_header;
        err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE, 0,
                               "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 = to_tpm_chip(dev);

        rc = tpm_getcap(chip, 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(to_tpm_chip(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);

static ssize_t active_show(struct device *dev, struct device_attribute *attr,
                    char *buf)
{
        cap_t cap;
        ssize_t rc;

        rc = tpm_getcap(to_tpm_chip(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(to_tpm_chip(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(to_tpm_chip(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)
{
        struct tpm_chip *chip = to_tpm_chip(dev);
        cap_t cap;
        ssize_t rc;
        char *str = buf;

        rc = tpm_getcap(chip, 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(chip, 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(chip, 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 = to_tpm_chip(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 = to_tpm_chip(dev);

        if (chip->duration[TPM_LONG] == 0)
                return 0;

        return sprintf(buf, "%d %d %d [%s]\n",
                       jiffies_to_usecs(chip->duration[TPM_SHORT]),
                       jiffies_to_usecs(chip->duration[TPM_MEDIUM]),
                       jiffies_to_usecs(chip->duration[TPM_LONG]),
                       chip->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 = to_tpm_chip(dev);

        return sprintf(buf, "%d %d %d %d [%s]\n",
                       jiffies_to_usecs(chip->timeout_a),
                       jiffies_to_usecs(chip->timeout_b),
                       jiffies_to_usecs(chip->timeout_c),
                       jiffies_to_usecs(chip->timeout_d),
                       chip->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,
};

void tpm_sysfs_add_device(struct tpm_chip *chip)
{
        /* The sysfs routines rely on an implicit tpm_try_get_ops, device_del
         * is called before ops is null'd and the sysfs core synchronizes this
         * removal so that no callbacks are running or can run again
         */
        WARN_ON(chip->groups_cnt != 0);
        chip->groups[chip->groups_cnt++] = &tpm_dev_group;
}