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         memset(&tpm_cmd, 0, sizeof(tpm_cmd));
  42
  43         tpm_cmd.header.in = tpm_readpubek_header;
  44         err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE, 0,
  45                                "attempting to read the PUBEK");
  46         if (err)
  47                 goto out;
  48
  49         /*
  50            ignore header 10 bytes
  51            algorithm 32 bits (1 == RSA )
  52            encscheme 16 bits
  53            sigscheme 16 bits
  54            parameters (RSA 12->bytes: keybit, #primes, expbit)
  55            keylenbytes 32 bits
  56            256 byte modulus
  57            ignore checksum 20 bytes
  58          */
  59         data = tpm_cmd.params.readpubek_out_buffer;
  60         str +=
  61             sprintf(str,
  62                     "Algorithm: %02X %02X %02X %02X\n"
  63                     "Encscheme: %02X %02X\n"
  64                     "Sigscheme: %02X %02X\n"
  65                     "Parameters: %02X %02X %02X %02X "
  66                     "%02X %02X %02X %02X "
  67                     "%02X %02X %02X %02X\n"
  68                     "Modulus length: %d\n"
  69                     "Modulus:\n",
  70                     data[0], data[1], data[2], data[3],
  71                     data[4], data[5],
  72                     data[6], data[7],
  73                     data[12], data[13], data[14], data[15],
  74                     data[16], data[17], data[18], data[19],
  75                     data[20], data[21], data[22], data[23],
  76                     be32_to_cpu(*((__be32 *) (data + 24))));
  77
  78         for (i = 0; i < 256; i++) {
  79                 str += sprintf(str, "%02X ", data[i + 28]);
  80                 if ((i + 1) % 16 == 0)
  81                         str += sprintf(str, "\n");
  82         }
  83 out:
  84         rc = str - buf;
  85         return rc;
  86 }
  87 static DEVICE_ATTR_RO(pubek);
  88
  89 static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
  90                          char *buf)
  91 {
  92         cap_t cap;
  93         u8 digest[TPM_DIGEST_SIZE];
  94         ssize_t rc;
  95         int i, j, num_pcrs;
  96         char *str = buf;
  97         struct tpm_chip *chip = dev_get_drvdata(dev);
  98
  99         rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
 100                         "attempting to determine the number of PCRS");
 101         if (rc)
 102                 return 0;
 103
 104         num_pcrs = be32_to_cpu(cap.num_pcrs);
 105         for (i = 0; i < num_pcrs; i++) {
 106                 rc = tpm_pcr_read_dev(chip, i, digest);
 107                 if (rc)
 108                         break;
 109                 str += sprintf(str, "PCR-%02d: ", i);
 110                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 111                         str += sprintf(str, "%02X ", digest[j]);
 112                 str += sprintf(str, "\n");
 113         }
 114         return str - buf;
 115 }
 116 static DEVICE_ATTR_RO(pcrs);
 117
 118 static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
 119                      char *buf)
 120 {
 121         cap_t cap;
 122         ssize_t rc;
 123
 124         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 125                          "attempting to determine the permanent enabled state");
 126         if (rc)
 127                 return 0;
 128
 129         rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
 130         return rc;
 131 }
 132 static DEVICE_ATTR_RO(enabled);
 133
 134 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
 135                     char *buf)
 136 {
 137         cap_t cap;
 138         ssize_t rc;
 139
 140         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 141                          "attempting to determine the permanent active state");
 142         if (rc)
 143                 return 0;
 144
 145         rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
 146         return rc;
 147 }
 148 static DEVICE_ATTR_RO(active);
 149
 150 static ssize_t owned_show(struct device *dev, struct device_attribute *attr,
 151                           char *buf)
 152 {
 153         cap_t cap;
 154         ssize_t rc;
 155
 156         rc = tpm_getcap(dev, TPM_CAP_PROP_OWNER, &cap,
 157                          "attempting to determine the owner state");
 158         if (rc)
 159                 return 0;
 160
 161         rc = sprintf(buf, "%d\n", cap.owned);
 162         return rc;
 163 }
 164 static DEVICE_ATTR_RO(owned);
 165
 166 static ssize_t temp_deactivated_show(struct device *dev,
 167                                      struct device_attribute *attr, char *buf)
 168 {
 169         cap_t cap;
 170         ssize_t rc;
 171
 172         rc = tpm_getcap(dev, TPM_CAP_FLAG_VOL, &cap,
 173                          "attempting to determine the temporary state");
 174         if (rc)
 175                 return 0;
 176
 177         rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
 178         return rc;
 179 }
 180 static DEVICE_ATTR_RO(temp_deactivated);
 181
 182 static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
 183                          char *buf)
 184 {
 185         cap_t cap;
 186         ssize_t rc;
 187         char *str = buf;
 188
 189         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
 190                         "attempting to determine the manufacturer");
 191         if (rc)
 192                 return 0;
 193         str += sprintf(str, "Manufacturer: 0x%x\n",
 194                        be32_to_cpu(cap.manufacturer_id));
 195
 196         /* Try to get a TPM version 1.2 TPM_CAP_VERSION_INFO */
 197         rc = tpm_getcap(dev, CAP_VERSION_1_2, &cap,
 198                          "attempting to determine the 1.2 version");
 199         if (!rc) {
 200                 str += sprintf(str,
 201                                "TCG version: %d.%d\nFirmware version: %d.%d\n",
 202                                cap.tpm_version_1_2.Major,
 203                                cap.tpm_version_1_2.Minor,
 204                                cap.tpm_version_1_2.revMajor,
 205                                cap.tpm_version_1_2.revMinor);
 206         } else {
 207                 /* Otherwise just use TPM_STRUCT_VER */
 208                 rc = tpm_getcap(dev, CAP_VERSION_1_1, &cap,
 209                                 "attempting to determine the 1.1 version");
 210                 if (rc)
 211                         return 0;
 212                 str += sprintf(str,
 213                                "TCG version: %d.%d\nFirmware version: %d.%d\n",
 214                                cap.tpm_version.Major,
 215                                cap.tpm_version.Minor,
 216                                cap.tpm_version.revMajor,
 217                                cap.tpm_version.revMinor);
 218         }
 219
 220         return str - buf;
 221 }
 222 static DEVICE_ATTR_RO(caps);
 223
 224 static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
 225                             const char *buf, size_t count)
 226 {
 227         struct tpm_chip *chip = dev_get_drvdata(dev);
 228         if (chip == NULL)
 229                 return 0;
 230
 231         chip->ops->cancel(chip);
 232         return count;
 233 }
 234 static DEVICE_ATTR_WO(cancel);
 235
 236 static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
 237                               char *buf)
 238 {
 239         struct tpm_chip *chip = dev_get_drvdata(dev);
 240
 241         if (chip->vendor.duration[TPM_LONG] == 0)
 242                 return 0;
 243
 244         return sprintf(buf, "%d %d %d [%s]\n",
 245                        jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
 246                        jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
 247                        jiffies_to_usecs(chip->vendor.duration[TPM_LONG]),
 248                        chip->vendor.duration_adjusted
 249                        ? "adjusted" : "original");
 250 }
 251 static DEVICE_ATTR_RO(durations);
 252
 253 static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
 254                              char *buf)
 255 {
 256         struct tpm_chip *chip = dev_get_drvdata(dev);
 257
 258         return sprintf(buf, "%d %d %d %d [%s]\n",
 259                        jiffies_to_usecs(chip->vendor.timeout_a),
 260                        jiffies_to_usecs(chip->vendor.timeout_b),
 261                        jiffies_to_usecs(chip->vendor.timeout_c),
 262                        jiffies_to_usecs(chip->vendor.timeout_d),
 263                        chip->vendor.timeout_adjusted
 264                        ? "adjusted" : "original");
 265 }
 266 static DEVICE_ATTR_RO(timeouts);
 267
 268 static struct attribute *tpm_dev_attrs[] = {
 269         &dev_attr_pubek.attr,
 270         &dev_attr_pcrs.attr,
 271         &dev_attr_enabled.attr,
 272         &dev_attr_active.attr,
 273         &dev_attr_owned.attr,
 274         &dev_attr_temp_deactivated.attr,
 275         &dev_attr_caps.attr,
 276         &dev_attr_cancel.attr,
 277         &dev_attr_durations.attr,
 278         &dev_attr_timeouts.attr,
 279         NULL,
 280 };
 281
 282 static const struct attribute_group tpm_dev_group = {
 283         .attrs = tpm_dev_attrs,
 284 };
 285
 286 int tpm_sysfs_add_device(struct tpm_chip *chip)
 287 {
 288         int err;
 289
 290         /* XXX: If you wish to remove this restriction, you must first update
 291          * tpm_sysfs to explicitly lock chip->ops.
 292          */
 293         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 294                 return 0;
 295
 296         err = sysfs_create_group(&chip->dev.parent->kobj,
 297                                  &tpm_dev_group);
 298
 299         if (err)
 300                 dev_err(&chip->dev,
 301                         "failed to create sysfs attributes, %d\n", err);
 302         return err;
 303 }
 304
 305 void tpm_sysfs_del_device(struct tpm_chip *chip)
 306 {
 307         /* The sysfs routines rely on an implicit tpm_try_get_ops, this
 308          * function is called before ops is null'd and the sysfs core
 309          * synchronizes this removal so that no callbacks are running or can
 310          * run again
 311          */
 312         sysfs_remove_group(&chip->dev.parent->kobj, &tpm_dev_group);
 313 }