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