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 /* XXX for now this helper is duplicated in tpm-interface.c */
  24 static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
  25                             int len, const char *desc)
  26 {
  27         int err;
  28
  29         len = tpm_transmit(chip, (u8 *) cmd, len);
  30         if (len <  0)
  31                 return len;
  32         else if (len < TPM_HEADER_SIZE)
  33                 return -EFAULT;
  34
  35         err = be32_to_cpu(cmd->header.out.return_code);
  36         if (err != 0 && desc)
  37                 dev_err(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
  38
  39         return err;
  40 }
  41
  42 #define READ_PUBEK_RESULT_SIZE 314
  43 #define TPM_ORD_READPUBEK cpu_to_be32(124)
  44 static struct tpm_input_header tpm_readpubek_header = {
  45         .tag = TPM_TAG_RQU_COMMAND,
  46         .length = cpu_to_be32(30),
  47         .ordinal = TPM_ORD_READPUBEK
  48 };
  49 static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
  50                           char *buf)
  51 {
  52         u8 *data;
  53         struct tpm_cmd_t tpm_cmd;
  54         ssize_t err;
  55         int i, rc;
  56         char *str = buf;
  57
  58         struct tpm_chip *chip = dev_get_drvdata(dev);
  59
  60         tpm_cmd.header.in = tpm_readpubek_header;
  61         err = transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
  62                            "attempting to read the PUBEK");
  63         if (err)
  64                 goto out;
  65
  66         /*
  67            ignore header 10 bytes
  68            algorithm 32 bits (1 == RSA )
  69            encscheme 16 bits
  70            sigscheme 16 bits
  71            parameters (RSA 12->bytes: keybit, #primes, expbit)
  72            keylenbytes 32 bits
  73            256 byte modulus
  74            ignore checksum 20 bytes
  75          */
  76         data = tpm_cmd.params.readpubek_out_buffer;
  77         str +=
  78             sprintf(str,
  79                     "Algorithm: %02X %02X %02X %02X\n"
  80                     "Encscheme: %02X %02X\n"
  81                     "Sigscheme: %02X %02X\n"
  82                     "Parameters: %02X %02X %02X %02X "
  83                     "%02X %02X %02X %02X "
  84                     "%02X %02X %02X %02X\n"
  85                     "Modulus length: %d\n"
  86                     "Modulus:\n",
  87                     data[0], data[1], data[2], data[3],
  88                     data[4], data[5],
  89                     data[6], data[7],
  90                     data[12], data[13], data[14], data[15],
  91                     data[16], data[17], data[18], data[19],
  92                     data[20], data[21], data[22], data[23],
  93                     be32_to_cpu(*((__be32 *) (data + 24))));
  94
  95         for (i = 0; i < 256; i++) {
  96                 str += sprintf(str, "%02X ", data[i + 28]);
  97                 if ((i + 1) % 16 == 0)
  98                         str += sprintf(str, "\n");
  99         }
 100 out:
 101         rc = str - buf;
 102         return rc;
 103 }
 104 static DEVICE_ATTR_RO(pubek);
 105
 106 static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
 107                          char *buf)
 108 {
 109         cap_t cap;
 110         u8 digest[TPM_DIGEST_SIZE];
 111         ssize_t rc;
 112         int i, j, num_pcrs;
 113         char *str = buf;
 114         struct tpm_chip *chip = dev_get_drvdata(dev);
 115
 116         rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
 117                         "attempting to determine the number of PCRS");
 118         if (rc)
 119                 return 0;
 120
 121         num_pcrs = be32_to_cpu(cap.num_pcrs);
 122         for (i = 0; i < num_pcrs; i++) {
 123                 rc = tpm_pcr_read_dev(chip, i, digest);
 124                 if (rc)
 125                         break;
 126                 str += sprintf(str, "PCR-%02d: ", i);
 127                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 128                         str += sprintf(str, "%02X ", digest[j]);
 129                 str += sprintf(str, "\n");
 130         }
 131         return str - buf;
 132 }
 133 static DEVICE_ATTR_RO(pcrs);
 134
 135 static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
 136                      char *buf)
 137 {
 138         cap_t cap;
 139         ssize_t rc;
 140
 141         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 142                          "attempting to determine the permanent enabled state");
 143         if (rc)
 144                 return 0;
 145
 146         rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
 147         return rc;
 148 }
 149 static DEVICE_ATTR_RO(enabled);
 150
 151 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
 152                     char *buf)
 153 {
 154         cap_t cap;
 155         ssize_t rc;
 156
 157         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 158                          "attempting to determine the permanent active state");
 159         if (rc)
 160                 return 0;
 161
 162         rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
 163         return rc;
 164 }
 165 static DEVICE_ATTR_RO(active);
 166
 167 static ssize_t owned_show(struct device *dev, struct device_attribute *attr,
 168                           char *buf)
 169 {
 170         cap_t cap;
 171         ssize_t rc;
 172
 173         rc = tpm_getcap(dev, TPM_CAP_PROP_OWNER, &cap,
 174                          "attempting to determine the owner state");
 175         if (rc)
 176                 return 0;
 177
 178         rc = sprintf(buf, "%d\n", cap.owned);
 179         return rc;
 180 }
 181 static DEVICE_ATTR_RO(owned);
 182
 183 static ssize_t temp_deactivated_show(struct device *dev,
 184                                      struct device_attribute *attr, char *buf)
 185 {
 186         cap_t cap;
 187         ssize_t rc;
 188
 189         rc = tpm_getcap(dev, TPM_CAP_FLAG_VOL, &cap,
 190                          "attempting to determine the temporary state");
 191         if (rc)
 192                 return 0;
 193
 194         rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
 195         return rc;
 196 }
 197 static DEVICE_ATTR_RO(temp_deactivated);
 198
 199 static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
 200                          char *buf)
 201 {
 202         cap_t cap;
 203         ssize_t rc;
 204         char *str = buf;
 205
 206         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
 207                         "attempting to determine the manufacturer");
 208         if (rc)
 209                 return 0;
 210         str += sprintf(str, "Manufacturer: 0x%x\n",
 211                        be32_to_cpu(cap.manufacturer_id));
 212
 213         /* Try to get a TPM version 1.2 TPM_CAP_VERSION_INFO */
 214         rc = tpm_getcap(dev, CAP_VERSION_1_2, &cap,
 215                          "attempting to determine the 1.2 version");
 216         if (!rc) {
 217                 str += sprintf(str,
 218                                "TCG version: %d.%d\nFirmware version: %d.%d\n",
 219                                cap.tpm_version_1_2.Major,
 220                                cap.tpm_version_1_2.Minor,
 221                                cap.tpm_version_1_2.revMajor,
 222                                cap.tpm_version_1_2.revMinor);
 223         } else {
 224                 /* Otherwise just use TPM_STRUCT_VER */
 225                 rc = tpm_getcap(dev, CAP_VERSION_1_1, &cap,
 226                                 "attempting to determine the 1.1 version");
 227                 if (rc)
 228                         return 0;
 229                 str += sprintf(str,
 230                                "TCG version: %d.%d\nFirmware version: %d.%d\n",
 231                                cap.tpm_version.Major,
 232                                cap.tpm_version.Minor,
 233                                cap.tpm_version.revMajor,
 234                                cap.tpm_version.revMinor);
 235         }
 236
 237         return str - buf;
 238 }
 239 static DEVICE_ATTR_RO(caps);
 240
 241 static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
 242                             const char *buf, size_t count)
 243 {
 244         struct tpm_chip *chip = dev_get_drvdata(dev);
 245         if (chip == NULL)
 246                 return 0;
 247
 248         chip->ops->cancel(chip);
 249         return count;
 250 }
 251 static DEVICE_ATTR_WO(cancel);
 252
 253 static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
 254                               char *buf)
 255 {
 256         struct tpm_chip *chip = dev_get_drvdata(dev);
 257
 258         if (chip->vendor.duration[TPM_LONG] == 0)
 259                 return 0;
 260
 261         return sprintf(buf, "%d %d %d [%s]\n",
 262                        jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
 263                        jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
 264                        jiffies_to_usecs(chip->vendor.duration[TPM_LONG]),
 265                        chip->vendor.duration_adjusted
 266                        ? "adjusted" : "original");
 267 }
 268 static DEVICE_ATTR_RO(durations);
 269
 270 static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
 271                              char *buf)
 272 {
 273         struct tpm_chip *chip = dev_get_drvdata(dev);
 274
 275         return sprintf(buf, "%d %d %d %d [%s]\n",
 276                        jiffies_to_usecs(chip->vendor.timeout_a),
 277                        jiffies_to_usecs(chip->vendor.timeout_b),
 278                        jiffies_to_usecs(chip->vendor.timeout_c),
 279                        jiffies_to_usecs(chip->vendor.timeout_d),
 280                        chip->vendor.timeout_adjusted
 281                        ? "adjusted" : "original");
 282 }
 283 static DEVICE_ATTR_RO(timeouts);
 284
 285 static struct attribute *tpm_dev_attrs[] = {
 286         &dev_attr_pubek.attr,
 287         &dev_attr_pcrs.attr,
 288         &dev_attr_enabled.attr,
 289         &dev_attr_active.attr,
 290         &dev_attr_owned.attr,
 291         &dev_attr_temp_deactivated.attr,
 292         &dev_attr_caps.attr,
 293         &dev_attr_cancel.attr,
 294         &dev_attr_durations.attr,
 295         &dev_attr_timeouts.attr,
 296         NULL,
 297 };
 298
 299 static const struct attribute_group tpm_dev_group = {
 300         .attrs = tpm_dev_attrs,
 301 };
 302
 303 int tpm_sysfs_add_device(struct tpm_chip *chip)
 304 {
 305         int err;
 306         err = sysfs_create_group(&chip->dev->kobj,
 307                                  &tpm_dev_group);
 308
 309         if (err)
 310                 dev_err(chip->dev,
 311                         "failed to create sysfs attributes, %d\n", err);
 312         return err;
 313 }
 314
 315 void tpm_sysfs_del_device(struct tpm_chip *chip)
 316 {
 317         sysfs_remove_group(&chip->dev->kobj, &tpm_dev_group);
 318 }