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  1/*
  2 * Copyright (C) 2005, 2012 IBM Corporation
  3 *
  4 * Authors:
  5 *	Kent Yoder <key@linux.vnet.ibm.com>
  6 *	Seiji Munetoh <munetoh@jp.ibm.com>
  7 *	Stefan Berger <stefanb@us.ibm.com>
  8 *	Reiner Sailer <sailer@watson.ibm.com>
  9 *	Kylene Hall <kjhall@us.ibm.com>
 10 *
 11 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
 12 *
 13 * Access to the eventlog created by a system's firmware / BIOS
 14 *
 15 * This program is free software; you can redistribute it and/or
 16 * modify it under the terms of the GNU General Public License
 17 * as published by the Free Software Foundation; either version
 18 * 2 of the License, or (at your option) any later version.
 19 *
 20 */
 21
 22#include <linux/seq_file.h>
 23#include <linux/fs.h>
 24#include <linux/security.h>
 25#include <linux/module.h>
 26#include <linux/slab.h>
 27
 28#include "tpm.h"
 29#include "tpm_eventlog.h"
 30
 31
 32static const char* tcpa_event_type_strings[] = {
 33	"PREBOOT",
 34	"POST CODE",
 35	"",
 36	"NO ACTION",
 37	"SEPARATOR",
 38	"ACTION",
 39	"EVENT TAG",
 40	"S-CRTM Contents",
 41	"S-CRTM Version",
 42	"CPU Microcode",
 43	"Platform Config Flags",
 44	"Table of Devices",
 45	"Compact Hash",
 46	"IPL",
 47	"IPL Partition Data",
 48	"Non-Host Code",
 49	"Non-Host Config",
 50	"Non-Host Info"
 51};
 52
 53static const char* tcpa_pc_event_id_strings[] = {
 54	"",
 55	"SMBIOS",
 56	"BIS Certificate",
 57	"POST BIOS ",
 58	"ESCD ",
 59	"CMOS",
 60	"NVRAM",
 61	"Option ROM",
 62	"Option ROM config",
 63	"",
 64	"Option ROM microcode ",
 65	"S-CRTM Version",
 66	"S-CRTM Contents ",
 67	"POST Contents ",
 68	"Table of Devices",
 69};
 70
 71/* returns pointer to start of pos. entry of tcg log */
 72static void *tpm_bios_measurements_start(struct seq_file *m, loff_t *pos)
 73{
 74	loff_t i;
 75	struct tpm_bios_log *log = m->private;
 76	void *addr = log->bios_event_log;
 77	void *limit = log->bios_event_log_end;
 78	struct tcpa_event *event;
 79	u32 converted_event_size;
 80	u32 converted_event_type;
 81
 82
 83	/* read over *pos measurements */
 84	for (i = 0; i < *pos; i++) {
 85		event = addr;
 86
 87		converted_event_size =
 88		    do_endian_conversion(event->event_size);
 89		converted_event_type =
 90		    do_endian_conversion(event->event_type);
 91
 92		if ((addr + sizeof(struct tcpa_event)) < limit) {
 93			if ((converted_event_type == 0) &&
 94			    (converted_event_size == 0))
 95				return NULL;
 96			addr += (sizeof(struct tcpa_event) +
 97				 converted_event_size);
 98		}
 99	}
100
101	/* now check if current entry is valid */
102	if ((addr + sizeof(struct tcpa_event)) >= limit)
103		return NULL;
104
105	event = addr;
106
107	converted_event_size = do_endian_conversion(event->event_size);
108	converted_event_type = do_endian_conversion(event->event_type);
109
110	if (((converted_event_type == 0) && (converted_event_size == 0))
111	    || ((addr + sizeof(struct tcpa_event) + converted_event_size)
112		>= limit))
113		return NULL;
114
115	return addr;
116}
117
118static void *tpm_bios_measurements_next(struct seq_file *m, void *v,
119					loff_t *pos)
120{
121	struct tcpa_event *event = v;
122	struct tpm_bios_log *log = m->private;
123	void *limit = log->bios_event_log_end;
124	u32 converted_event_size;
125	u32 converted_event_type;
126
127	converted_event_size = do_endian_conversion(event->event_size);
128
129	v += sizeof(struct tcpa_event) + converted_event_size;
130
131	/* now check if current entry is valid */
132	if ((v + sizeof(struct tcpa_event)) >= limit)
133		return NULL;
134
135	event = v;
136
137	converted_event_size = do_endian_conversion(event->event_size);
138	converted_event_type = do_endian_conversion(event->event_type);
139
140	if (((converted_event_type == 0) && (converted_event_size == 0)) ||
141	    ((v + sizeof(struct tcpa_event) + converted_event_size) >= limit))
142		return NULL;
143
144	(*pos)++;
145	return v;
146}
147
148static void tpm_bios_measurements_stop(struct seq_file *m, void *v)
149{
150}
151
152static int get_event_name(char *dest, struct tcpa_event *event,
153			unsigned char * event_entry)
154{
155	const char *name = "";
156	/* 41 so there is room for 40 data and 1 nul */
157	char data[41] = "";
158	int i, n_len = 0, d_len = 0;
159	struct tcpa_pc_event *pc_event;
160
161	switch (do_endian_conversion(event->event_type)) {
162	case PREBOOT:
163	case POST_CODE:
164	case UNUSED:
165	case NO_ACTION:
166	case SCRTM_CONTENTS:
167	case SCRTM_VERSION:
168	case CPU_MICROCODE:
169	case PLATFORM_CONFIG_FLAGS:
170	case TABLE_OF_DEVICES:
171	case COMPACT_HASH:
172	case IPL:
173	case IPL_PARTITION_DATA:
174	case NONHOST_CODE:
175	case NONHOST_CONFIG:
176	case NONHOST_INFO:
177		name = tcpa_event_type_strings[do_endian_conversion
178						(event->event_type)];
179		n_len = strlen(name);
180		break;
181	case SEPARATOR:
182	case ACTION:
183		if (MAX_TEXT_EVENT >
184		    do_endian_conversion(event->event_size)) {
185			name = event_entry;
186			n_len = do_endian_conversion(event->event_size);
187		}
188		break;
189	case EVENT_TAG:
190		pc_event = (struct tcpa_pc_event *)event_entry;
191
192		/* ToDo Row data -> Base64 */
193
194		switch (do_endian_conversion(pc_event->event_id)) {
195		case SMBIOS:
196		case BIS_CERT:
197		case CMOS:
198		case NVRAM:
199		case OPTION_ROM_EXEC:
200		case OPTION_ROM_CONFIG:
201		case S_CRTM_VERSION:
202			name = tcpa_pc_event_id_strings[do_endian_conversion
203							(pc_event->event_id)];
204			n_len = strlen(name);
205			break;
206		/* hash data */
207		case POST_BIOS_ROM:
208		case ESCD:
209		case OPTION_ROM_MICROCODE:
210		case S_CRTM_CONTENTS:
211		case POST_CONTENTS:
212			name = tcpa_pc_event_id_strings[do_endian_conversion
213							(pc_event->event_id)];
214			n_len = strlen(name);
215			for (i = 0; i < 20; i++)
216				d_len += sprintf(&data[2*i], "%02x",
217						pc_event->event_data[i]);
218			break;
219		default:
220			break;
221		}
222	default:
223		break;
224	}
225
226	return snprintf(dest, MAX_TEXT_EVENT, "[%.*s%.*s]",
227			n_len, name, d_len, data);
228
229}
230
231static int tpm_binary_bios_measurements_show(struct seq_file *m, void *v)
232{
233	struct tcpa_event *event = v;
234	struct tcpa_event temp_event;
235	char *temp_ptr;
236	int i;
237
238	memcpy(&temp_event, event, sizeof(struct tcpa_event));
239
240	/* convert raw integers for endianness */
241	temp_event.pcr_index = do_endian_conversion(event->pcr_index);
242	temp_event.event_type = do_endian_conversion(event->event_type);
243	temp_event.event_size = do_endian_conversion(event->event_size);
244
245	temp_ptr = (char *) &temp_event;
246
247	for (i = 0; i < (sizeof(struct tcpa_event) - 1) ; i++)
248		seq_putc(m, temp_ptr[i]);
249
250	temp_ptr = (char *) v;
251
252	for (i = (sizeof(struct tcpa_event) - 1);
253	     i < (sizeof(struct tcpa_event) + temp_event.event_size); i++)
254		seq_putc(m, temp_ptr[i]);
255
256	return 0;
257
258}
259
260static int tpm_bios_measurements_release(struct inode *inode,
261					 struct file *file)
262{
263	struct seq_file *seq = file->private_data;
264	struct tpm_bios_log *log = seq->private;
265
266	if (log) {
267		kfree(log->bios_event_log);
268		kfree(log);
269	}
270
271	return seq_release(inode, file);
272}
273
274static int tpm_ascii_bios_measurements_show(struct seq_file *m, void *v)
275{
276	int len = 0;
277	char *eventname;
278	struct tcpa_event *event = v;
279	unsigned char *event_entry =
280	    (unsigned char *)(v + sizeof(struct tcpa_event));
281
282	eventname = kmalloc(MAX_TEXT_EVENT, GFP_KERNEL);
283	if (!eventname) {
284		printk(KERN_ERR "%s: ERROR - No Memory for event name\n ",
285		       __func__);
286		return -EFAULT;
287	}
288
289	/* 1st: PCR */
290	seq_printf(m, "%2d ", do_endian_conversion(event->pcr_index));
291
292	/* 2nd: SHA1 */
293	seq_printf(m, "%20phN", event->pcr_value);
294
295	/* 3rd: event type identifier */
296	seq_printf(m, " %02x", do_endian_conversion(event->event_type));
297
298	len += get_event_name(eventname, event, event_entry);
299
300	/* 4th: eventname <= max + \'0' delimiter */
301	seq_printf(m, " %s\n", eventname);
302
303	kfree(eventname);
304	return 0;
305}
306
307static const struct seq_operations tpm_ascii_b_measurments_seqops = {
308	.start = tpm_bios_measurements_start,
309	.next = tpm_bios_measurements_next,
310	.stop = tpm_bios_measurements_stop,
311	.show = tpm_ascii_bios_measurements_show,
312};
313
314static const struct seq_operations tpm_binary_b_measurments_seqops = {
315	.start = tpm_bios_measurements_start,
316	.next = tpm_bios_measurements_next,
317	.stop = tpm_bios_measurements_stop,
318	.show = tpm_binary_bios_measurements_show,
319};
320
321static int tpm_ascii_bios_measurements_open(struct inode *inode,
322					    struct file *file)
323{
324	int err;
325	struct tpm_bios_log *log;
326	struct seq_file *seq;
327
328	log = kzalloc(sizeof(struct tpm_bios_log), GFP_KERNEL);
329	if (!log)
330		return -ENOMEM;
331
332	if ((err = read_log(log)))
333		goto out_free;
334
335	/* now register seq file */
336	err = seq_open(file, &tpm_ascii_b_measurments_seqops);
337	if (!err) {
338		seq = file->private_data;
339		seq->private = log;
340	} else {
341		goto out_free;
342	}
343
344out:
345	return err;
346out_free:
347	kfree(log->bios_event_log);
348	kfree(log);
349	goto out;
350}
351
352static const struct file_operations tpm_ascii_bios_measurements_ops = {
353	.open = tpm_ascii_bios_measurements_open,
354	.read = seq_read,
355	.llseek = seq_lseek,
356	.release = tpm_bios_measurements_release,
357};
358
359static int tpm_binary_bios_measurements_open(struct inode *inode,
360					     struct file *file)
361{
362	int err;
363	struct tpm_bios_log *log;
364	struct seq_file *seq;
365
366	log = kzalloc(sizeof(struct tpm_bios_log), GFP_KERNEL);
367	if (!log)
368		return -ENOMEM;
369
370	if ((err = read_log(log)))
371		goto out_free;
372
373	/* now register seq file */
374	err = seq_open(file, &tpm_binary_b_measurments_seqops);
375	if (!err) {
376		seq = file->private_data;
377		seq->private = log;
378	} else {
379		goto out_free;
380	}
381
382out:
383	return err;
384out_free:
385	kfree(log->bios_event_log);
386	kfree(log);
387	goto out;
388}
389
390static const struct file_operations tpm_binary_bios_measurements_ops = {
391	.open = tpm_binary_bios_measurements_open,
392	.read = seq_read,
393	.llseek = seq_lseek,
394	.release = tpm_bios_measurements_release,
395};
396
397static int is_bad(void *p)
398{
399	if (!p)
400		return 1;
401	if (IS_ERR(p) && (PTR_ERR(p) != -ENODEV))
402		return 1;
403	return 0;
404}
405
406struct dentry **tpm_bios_log_setup(char *name)
407{
408	struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;
409
410	tpm_dir = securityfs_create_dir(name, NULL);
411	if (is_bad(tpm_dir))
412		goto out;
413
414	bin_file =
415	    securityfs_create_file("binary_bios_measurements",
416				   S_IRUSR | S_IRGRP, tpm_dir, NULL,
417				   &tpm_binary_bios_measurements_ops);
418	if (is_bad(bin_file))
419		goto out_tpm;
420
421	ascii_file =
422	    securityfs_create_file("ascii_bios_measurements",
423				   S_IRUSR | S_IRGRP, tpm_dir, NULL,
424				   &tpm_ascii_bios_measurements_ops);
425	if (is_bad(ascii_file))
426		goto out_bin;
427
428	ret = kmalloc(3 * sizeof(struct dentry *), GFP_KERNEL);
429	if (!ret)
430		goto out_ascii;
431
432	ret[0] = ascii_file;
433	ret[1] = bin_file;
434	ret[2] = tpm_dir;
435
436	return ret;
437
438out_ascii:
439	securityfs_remove(ascii_file);
440out_bin:
441	securityfs_remove(bin_file);
442out_tpm:
443	securityfs_remove(tpm_dir);
444out:
445	return NULL;
446}
447
448void tpm_bios_log_teardown(struct dentry **lst)
449{
450	int i;
451
452	for (i = 0; i < 3; i++)
453		securityfs_remove(lst[i]);
454}