drivers/char/tpm/tpm-sysfs.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  * Authors:
   4  * Leendert van Doorn <leendert@watson.ibm.com>
   5  * Dave Safford <safford@watson.ibm.com>
   6  * Reiner Sailer <sailer@watson.ibm.com>
   7  * Kylene Hall <kjhall@us.ibm.com>
   8  *
   9  * Copyright (C) 2013 Obsidian Research Corp
  10  * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
  11  *
  12  * sysfs filesystem inspection interface to the TPM
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License as
  16  * published by the Free Software Foundation, version 2 of the
  17  * License.
  18  *
  19  */
  20 #include <linux/device.h>
  21 #include "tpm.h"
  22
  23 #define READ_PUBEK_RESULT_SIZE 314
  24 #define TPM_ORD_READPUBEK cpu_to_be32(124)
  25 static struct tpm_input_header tpm_readpubek_header = {
  26         .tag = TPM_TAG_RQU_COMMAND,
  27         .length = cpu_to_be32(30),
  28         .ordinal = TPM_ORD_READPUBEK
  29 };
  30 static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
  31                           char *buf)
  32 {
  33         u8 *data;
  34         struct tpm_cmd_t tpm_cmd;
  35         ssize_t err;
  36         int i, rc;
  37         char *str = buf;
  38
  39         struct tpm_chip *chip = dev_get_drvdata(dev);
  40
  41         tpm_cmd.header.in = tpm_readpubek_header;
  42         err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
  43                                "attempting to read the PUBEK");
  44         if (err)
  45                 goto out;
  46
  47         /*
  48            ignore header 10 bytes
  49            algorithm 32 bits (1 == RSA )
  50            encscheme 16 bits
  51            sigscheme 16 bits
  52            parameters (RSA 12->bytes: keybit, #primes, expbit)
  53            keylenbytes 32 bits
  54            256 byte modulus
  55            ignore checksum 20 bytes
  56          */
  57         data = tpm_cmd.params.readpubek_out_buffer;
  58         str +=
  59             sprintf(str,
  60                     "Algorithm: %02X %02X %02X %02X\n"
  61                     "Encscheme: %02X %02X\n"
  62                     "Sigscheme: %02X %02X\n"
  63                     "Parameters: %02X %02X %02X %02X "
  64                     "%02X %02X %02X %02X "
  65                     "%02X %02X %02X %02X\n"
  66                     "Modulus length: %d\n"
  67                     "Modulus:\n",
  68                     data[0], data[1], data[2], data[3],
  69                     data[4], data[5],
  70                     data[6], data[7],
  71                     data[12], data[13], data[14], data[15],
  72                     data[16], data[17], data[18], data[19],
  73                     data[20], data[21], data[22], data[23],
  74                     be32_to_cpu(*((__be32 *) (data + 24))));
  75
  76         for (i = 0; i < 256; i++) {
  77                 str += sprintf(str, "%02X ", data[i + 28]);
  78                 if ((i + 1) % 16 == 0)
  79                         str += sprintf(str, "\n");
  80         }
  81 out:
  82         rc = str - buf;
  83         return rc;
  84 }
  85 static DEVICE_ATTR_RO(pubek);
  86
  87 static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
  88                          char *buf)
  89 {
  90         cap_t cap;
  91         u8 digest[TPM_DIGEST_SIZE];
  92         ssize_t rc;
  93         int i, j, num_pcrs;
  94         char *str = buf;
  95         struct tpm_chip *chip = dev_get_drvdata(dev);
  96
  97         rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
  98                         "attempting to determine the number of PCRS");
  99         if (rc)
 100                 return 0;
 101
 102         num_pcrs = be32_to_cpu(cap.num_pcrs);
 103         for (i = 0; i < num_pcrs; i++) {
 104                 rc = tpm_pcr_read_dev(chip, i, digest);
 105                 if (rc)
 106                         break;
 107                 str += sprintf(str, "PCR-%02d: ", i);
 108                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 109                         str += sprintf(str, "%02X ", digest[j]);
 110                 str += sprintf(str, "\n");
 111         }
 112         return str - buf;
 113 }
 114 static DEVICE_ATTR_RO(pcrs);
 115
 116 static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
 117                      char *buf)
 118 {
 119         cap_t cap;
 120         ssize_t rc;
 121
 122         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 123                          "attempting to determine the permanent enabled state");
 124         if (rc)
 125                 return 0;
 126
 127         rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
 128         return rc;
 129 }
 130 static DEVICE_ATTR_RO(enabled);
 131
 132 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
 133                     char *buf)
 134 {
 135         cap_t cap;
 136         ssize_t rc;
 137
 138         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 139                          "attempting to determine the permanent active state");
 140         if (rc)
 141                 return 0;
 142
 143         rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
 144         return rc;
 145 }
 146 static DEVICE_ATTR_RO(active);
 147
 148 static ssize_t owned_show(struct device *dev, struct device_attribute *attr,
 149                           char *buf)
 150 {
 151         cap_t cap;
 152         ssize_t rc;
 153
 154         rc = tpm_getcap(dev, TPM_CAP_PROP_OWNER, &cap,
 155                          "attempting to determine the owner state");
 156         if (rc)
 157                 return 0;
 158
 159         rc = sprintf(buf, "%d\n", cap.owned);
 160         return rc;
 161 }
 162 static DEVICE_ATTR_RO(owned);
 163
 164 static ssize_t temp_deactivated_show(struct device *dev,
 165                                      struct device_attribute *attr, char *buf)
 166 {
 167         cap_t cap;
 168         ssize_t rc;
 169
 170         rc = tpm_getcap(dev, TPM_CAP_FLAG_VOL, &cap,
 171                          "attempting to determine the temporary state");
 172         if (rc)
 173                 return 0;
 174
 175         rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
 176         return rc;
 177 }
 178 static DEVICE_ATTR_RO(temp_deactivated);
 179
 180 static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
 181                          char *buf)
 182 {
 183         cap_t cap;
 184         ssize_t rc;
 185         char *str = buf;
 186
 187         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
 188                         "attempting to determine the manufacturer");
 189         if (rc)
 190                 return 0;
 191         str += sprintf(str, "Manufacturer: 0x%x\n",
 192                        be32_to_cpu(cap.manufacturer_id));
 193
 194         /* Try to get a TPM version 1.2 TPM_CAP_VERSION_INFO */
 195         rc = tpm_getcap(dev, CAP_VERSION_1_2, &cap,
 196                          "attempting to determine the 1.2 version");
 197         if (!rc) {
 198                 str += sprintf(str,
 199                                "TCG version: %d.%d\nFirmware version: %d.%d\n",
 200                                cap.tpm_version_1_2.Major,
 201                                cap.tpm_version_1_2.Minor,
 202                                cap.tpm_version_1_2.revMajor,
 203                                cap.tpm_version_1_2.revMinor);
 204         } else {
 205                 /* Otherwise just use TPM_STRUCT_VER */
 206                 rc = tpm_getcap(dev, CAP_VERSION_1_1, &cap,
 207                                 "attempting to determine the 1.1 version");
 208                 if (rc)
 209                         return 0;
 210                 str += sprintf(str,
 211                                "TCG version: %d.%d\nFirmware version: %d.%d\n",
 212                                cap.tpm_version.Major,
 213                                cap.tpm_version.Minor,
 214                                cap.tpm_version.revMajor,
 215                                cap.tpm_version.revMinor);
 216         }
 217
 218         return str - buf;
 219 }
 220 static DEVICE_ATTR_RO(caps);
 221
 222 static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
 223                             const char *buf, size_t count)
 224 {
 225         struct tpm_chip *chip = dev_get_drvdata(dev);
 226         if (chip == NULL)
 227                 return 0;
 228
 229         chip->ops->cancel(chip);
 230         return count;
 231 }
 232 static DEVICE_ATTR_WO(cancel);
 233
 234 static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
 235                               char *buf)
 236 {
 237         struct tpm_chip *chip = dev_get_drvdata(dev);
 238
 239         if (chip->vendor.duration[TPM_LONG] == 0)
 240                 return 0;
 241
 242         return sprintf(buf, "%d %d %d [%s]\n",
 243                        jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
 244                        jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
 245                        jiffies_to_usecs(chip->vendor.duration[TPM_LONG]),
 246                        chip->vendor.duration_adjusted
 247                        ? "adjusted" : "original");
 248 }
 249 static DEVICE_ATTR_RO(durations);
 250
 251 static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
 252                              char *buf)
 253 {
 254         struct tpm_chip *chip = dev_get_drvdata(dev);
 255
 256         return sprintf(buf, "%d %d %d %d [%s]\n",
 257                        jiffies_to_usecs(chip->vendor.timeout_a),
 258                        jiffies_to_usecs(chip->vendor.timeout_b),
 259                        jiffies_to_usecs(chip->vendor.timeout_c),
 260                        jiffies_to_usecs(chip->vendor.timeout_d),
 261                        chip->vendor.timeout_adjusted
 262                        ? "adjusted" : "original");
 263 }
 264 static DEVICE_ATTR_RO(timeouts);
 265
 266 static struct attribute *tpm_dev_attrs[] = {
 267         &dev_attr_pubek.attr,
 268         &dev_attr_pcrs.attr,
 269         &dev_attr_enabled.attr,
 270         &dev_attr_active.attr,
 271         &dev_attr_owned.attr,
 272         &dev_attr_temp_deactivated.attr,
 273         &dev_attr_caps.attr,
 274         &dev_attr_cancel.attr,
 275         &dev_attr_durations.attr,
 276         &dev_attr_timeouts.attr,
 277         NULL,
 278 };
 279
 280 static const struct attribute_group tpm_dev_group = {
 281         .attrs = tpm_dev_attrs,
 282 };
 283
 284 int tpm_sysfs_add_device(struct tpm_chip *chip)
 285 {
 286         int err;
 287         err = sysfs_create_group(&chip->pdev->kobj,
 288                                  &tpm_dev_group);
 289
 290         if (err)
 291                 dev_err(chip->pdev,
 292                         "failed to create sysfs attributes, %d\n", err);
 293         return err;
 294 }
 295
 296 void tpm_sysfs_del_device(struct tpm_chip *chip)
 297 {
 298         sysfs_remove_group(&chip->pdev->kobj, &tpm_dev_group);
 299 }