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
 23struct 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
 37static 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}
 97static DEVICE_ATTR_RO(pubek);
 98
 99static 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}
127static DEVICE_ATTR_RO(pcrs);
128
129static 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}
144static DEVICE_ATTR_RO(enabled);
145
146static 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}
161static DEVICE_ATTR_RO(active);
162
163static 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}
178static DEVICE_ATTR_RO(owned);
179
180static 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}
195static DEVICE_ATTR_RO(temp_deactivated);
196
197static 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}
241static DEVICE_ATTR_RO(caps);
242
243static 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}
253static DEVICE_ATTR_WO(cancel);
254
255static 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}
270static DEVICE_ATTR_RO(durations);
271
272static 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}
285static DEVICE_ATTR_RO(timeouts);
286
287static 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
301static const struct attribute_group tpm_dev_group = {
302	.attrs = tpm_dev_attrs,
303};
304
305void 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}