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 struct tpm_readpubek_out {
  24         u8 algorithm[4];
  25         u8 encscheme[2];
  26         u8 sigscheme[2];
  27         __be32 paramsize;
  28         u8 parameters[12];
  29         __be32 keysize;
  30         u8 modulus[256];
  31         u8 checksum[20];
  32 } __packed;
  33
  34 #define READ_PUBEK_RESULT_MIN_BODY_SIZE (28 + 256)
  35 #define TPM_ORD_READPUBEK 124
  36
  37 static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
  38                           char *buf)
  39 {
  40         struct tpm_buf tpm_buf;
  41         struct tpm_readpubek_out *out;
  42         int i;
  43         char *str = buf;
  44         struct tpm_chip *chip = to_tpm_chip(dev);
  45         char anti_replay[20];
  46
  47         memset(&anti_replay, 0, sizeof(anti_replay));
  48
  49         if (tpm_try_get_ops(chip))
  50                 return 0;
  51
  52         if (tpm_buf_init(&tpm_buf, TPM_TAG_RQU_COMMAND, TPM_ORD_READPUBEK))
  53                 goto out_ops;
  54
  55         tpm_buf_append(&tpm_buf, anti_replay, sizeof(anti_replay));
  56
  57         if (tpm_transmit_cmd(chip, NULL, tpm_buf.data, PAGE_SIZE,
  58                               READ_PUBEK_RESULT_MIN_BODY_SIZE, 0,
  59                               "attempting to read the PUBEK"))
  60                 goto out_buf;
  61
  62         out = (struct tpm_readpubek_out *)&tpm_buf.data[10];
  63         str +=
  64             sprintf(str,
  65                     "Algorithm: %02X %02X %02X %02X\n"
  66                     "Encscheme: %02X %02X\n"
  67                     "Sigscheme: %02X %02X\n"
  68                     "Parameters: %02X %02X %02X %02X "
  69                     "%02X %02X %02X %02X "
  70                     "%02X %02X %02X %02X\n"
  71                     "Modulus length: %d\n"
  72                     "Modulus:\n",
  73                     out->algorithm[0], out->algorithm[1], out->algorithm[2],
  74                     out->algorithm[3],
  75                     out->encscheme[0], out->encscheme[1],
  76                     out->sigscheme[0], out->sigscheme[1],
  77                     out->parameters[0], out->parameters[1],
  78                     out->parameters[2], out->parameters[3],
  79                     out->parameters[4], out->parameters[5],
  80                     out->parameters[6], out->parameters[7],
  81                     out->parameters[8], out->parameters[9],
  82                     out->parameters[10], out->parameters[11],
  83                     be32_to_cpu(out->keysize));
  84
  85         for (i = 0; i < 256; i++) {
  86                 str += sprintf(str, "%02X ", out->modulus[i]);
  87                 if ((i + 1) % 16 == 0)
  88                         str += sprintf(str, "\n");
  89         }
  90
  91 out_buf:
  92         tpm_buf_destroy(&tpm_buf);
  93 out_ops:
  94         tpm_put_ops(chip);
  95         return str - buf;
  96 }
  97 static DEVICE_ATTR_RO(pubek);
  98
  99 static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
 100                          char *buf)
 101 {
 102         cap_t cap;
 103         u8 digest[TPM_DIGEST_SIZE];
 104         ssize_t rc;
 105         int i, j, num_pcrs;
 106         char *str = buf;
 107         struct tpm_chip *chip = to_tpm_chip(dev);
 108
 109         if (tpm_try_get_ops(chip))
 110                 return 0;
 111
 112         if (tpm_getcap(chip, TPM_CAP_PROP_PCR, &cap,
 113                        "attempting to determine the number of PCRS",
 114                        sizeof(cap.num_pcrs))) {
 115                 tpm_put_ops(chip);
 116                 return 0;
 117         }
 118
 119         num_pcrs = be32_to_cpu(cap.num_pcrs);
 120         for (i = 0; i < num_pcrs; i++) {
 121                 rc = tpm_pcr_read_dev(chip, i, digest);
 122                 if (rc)
 123                         break;
 124                 str += sprintf(str, "PCR-%02d: ", i);
 125                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 126                         str += sprintf(str, "%02X ", digest[j]);
 127                 str += sprintf(str, "\n");
 128         }
 129         tpm_put_ops(chip);
 130         return str - buf;
 131 }
 132 static DEVICE_ATTR_RO(pcrs);
 133
 134 static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
 135                      char *buf)
 136 {
 137         struct tpm_chip *chip = to_tpm_chip(dev);
 138         ssize_t rc = 0;
 139         cap_t cap;
 140
 141         if (tpm_try_get_ops(chip))
 142                 return 0;
 143
 144         if (tpm_getcap(chip, TPM_CAP_FLAG_PERM, &cap,
 145                        "attempting to determine the permanent enabled state",
 146                        sizeof(cap.perm_flags)))
 147                 goto out_ops;
 148
 149         rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
 150 out_ops:
 151         tpm_put_ops(chip);
 152         return rc;
 153 }
 154 static DEVICE_ATTR_RO(enabled);
 155
 156 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
 157                     char *buf)
 158 {
 159         struct tpm_chip *chip = to_tpm_chip(dev);
 160         ssize_t rc = 0;
 161         cap_t cap;
 162
 163         if (tpm_try_get_ops(chip))
 164                 return 0;
 165
 166         if (tpm_getcap(chip, TPM_CAP_FLAG_PERM, &cap,
 167                        "attempting to determine the permanent active state",
 168                        sizeof(cap.perm_flags)))
 169                 goto out_ops;
 170
 171         rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
 172 out_ops:
 173         tpm_put_ops(chip);
 174         return rc;
 175 }
 176 static DEVICE_ATTR_RO(active);
 177
 178 static ssize_t owned_show(struct device *dev, struct device_attribute *attr,
 179                           char *buf)
 180 {
 181         struct tpm_chip *chip = to_tpm_chip(dev);
 182         ssize_t rc = 0;
 183         cap_t cap;
 184
 185         if (tpm_try_get_ops(chip))
 186                 return 0;
 187
 188         if (tpm_getcap(to_tpm_chip(dev), TPM_CAP_PROP_OWNER, &cap,
 189                        "attempting to determine the owner state",
 190                        sizeof(cap.owned)))
 191                 goto out_ops;
 192
 193         rc = sprintf(buf, "%d\n", cap.owned);
 194 out_ops:
 195         tpm_put_ops(chip);
 196         return rc;
 197 }
 198 static DEVICE_ATTR_RO(owned);
 199
 200 static ssize_t temp_deactivated_show(struct device *dev,
 201                                      struct device_attribute *attr, char *buf)
 202 {
 203         struct tpm_chip *chip = to_tpm_chip(dev);
 204         ssize_t rc = 0;
 205         cap_t cap;
 206
 207         if (tpm_try_get_ops(chip))
 208                 return 0;
 209
 210         if (tpm_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_VOL, &cap,
 211                        "attempting to determine the temporary state",
 212                        sizeof(cap.stclear_flags)))
 213                 goto out_ops;
 214
 215         rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
 216 out_ops:
 217         tpm_put_ops(chip);
 218         return rc;
 219 }
 220 static DEVICE_ATTR_RO(temp_deactivated);
 221
 222 static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
 223                          char *buf)
 224 {
 225         struct tpm_chip *chip = to_tpm_chip(dev);
 226         ssize_t rc = 0;
 227         char *str = buf;
 228         cap_t cap;
 229
 230         if (tpm_try_get_ops(chip))
 231                 return 0;
 232
 233         if (tpm_getcap(chip, TPM_CAP_PROP_MANUFACTURER, &cap,
 234                        "attempting to determine the manufacturer",
 235                        sizeof(cap.manufacturer_id)))
 236                 goto out_ops;
 237
 238         str += sprintf(str, "Manufacturer: 0x%x\n",
 239                        be32_to_cpu(cap.manufacturer_id));
 240
 241         /* Try to get a TPM version 1.2 TPM_CAP_VERSION_INFO */
 242         rc = tpm_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
 243                         "attempting to determine the 1.2 version",
 244                         sizeof(cap.tpm_version_1_2));
 245         if (!rc) {
 246                 str += sprintf(str,
 247                                "TCG version: %d.%d\nFirmware version: %d.%d\n",
 248                                cap.tpm_version_1_2.Major,
 249                                cap.tpm_version_1_2.Minor,
 250                                cap.tpm_version_1_2.revMajor,
 251                                cap.tpm_version_1_2.revMinor);
 252         } else {
 253                 /* Otherwise just use TPM_STRUCT_VER */
 254                 if (tpm_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
 255                                "attempting to determine the 1.1 version",
 256                                sizeof(cap.tpm_version)))
 257                         goto out_ops;
 258
 259                 str += sprintf(str,
 260                                "TCG version: %d.%d\nFirmware version: %d.%d\n",
 261                                cap.tpm_version.Major,
 262                                cap.tpm_version.Minor,
 263                                cap.tpm_version.revMajor,
 264                                cap.tpm_version.revMinor);
 265 }
 266         rc = str - buf;
 267 out_ops:
 268         tpm_put_ops(chip);
 269         return rc;
 270 }
 271 static DEVICE_ATTR_RO(caps);
 272
 273 static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
 274                             const char *buf, size_t count)
 275 {
 276         struct tpm_chip *chip = to_tpm_chip(dev);
 277
 278         if (tpm_try_get_ops(chip))
 279                 return 0;
 280
 281         chip->ops->cancel(chip);
 282         tpm_put_ops(chip);
 283         return count;
 284 }
 285 static DEVICE_ATTR_WO(cancel);
 286
 287 static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
 288                               char *buf)
 289 {
 290         struct tpm_chip *chip = to_tpm_chip(dev);
 291
 292         if (chip->duration[TPM_LONG] == 0)
 293                 return 0;
 294
 295         return sprintf(buf, "%d %d %d [%s]\n",
 296                        jiffies_to_usecs(chip->duration[TPM_SHORT]),
 297                        jiffies_to_usecs(chip->duration[TPM_MEDIUM]),
 298                        jiffies_to_usecs(chip->duration[TPM_LONG]),
 299                        chip->duration_adjusted
 300                        ? "adjusted" : "original");
 301 }
 302 static DEVICE_ATTR_RO(durations);
 303
 304 static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
 305                              char *buf)
 306 {
 307         struct tpm_chip *chip = to_tpm_chip(dev);
 308
 309         return sprintf(buf, "%d %d %d %d [%s]\n",
 310                        jiffies_to_usecs(chip->timeout_a),
 311                        jiffies_to_usecs(chip->timeout_b),
 312                        jiffies_to_usecs(chip->timeout_c),
 313                        jiffies_to_usecs(chip->timeout_d),
 314                        chip->timeout_adjusted
 315                        ? "adjusted" : "original");
 316 }
 317 static DEVICE_ATTR_RO(timeouts);
 318
 319 static struct attribute *tpm_dev_attrs[] = {
 320         &dev_attr_pubek.attr,
 321         &dev_attr_pcrs.attr,
 322         &dev_attr_enabled.attr,
 323         &dev_attr_active.attr,
 324         &dev_attr_owned.attr,
 325         &dev_attr_temp_deactivated.attr,
 326         &dev_attr_caps.attr,
 327         &dev_attr_cancel.attr,
 328         &dev_attr_durations.attr,
 329         &dev_attr_timeouts.attr,
 330         NULL,
 331 };
 332
 333 static const struct attribute_group tpm_dev_group = {
 334         .attrs = tpm_dev_attrs,
 335 };
 336
 337 void tpm_sysfs_add_device(struct tpm_chip *chip)
 338 {
 339         /* XXX: If you wish to remove this restriction, you must first update
 340          * tpm_sysfs to explicitly lock chip->ops.
 341          */
 342         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 343                 return;
 344
 345         /* The sysfs routines rely on an implicit tpm_try_get_ops, device_del
 346          * is called before ops is null'd and the sysfs core synchronizes this
 347          * removal so that no callbacks are running or can run again
 348          */
 349         WARN_ON(chip->groups_cnt != 0);
 350         chip->groups[chip->groups_cnt++] = &tpm_dev_group;
 351 }