tpm: modularize event log collection

Break ACPI-specific pieces of the event log handling into their own file
and create tpm_eventlog.[ch] to store common event log handling code.
This will be required to integrate future event log sources on platforms
without ACPI tables.

Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>

1 files changed, 419 insertions, 0 deletions

diff --git a/drivers/char/tpm/tpm_eventlog.c b/drivers/char/tpm/tpm_eventlog.c
new file mode 100644
index 000000000000..84ddc557b8f8
--- /dev/null
+++ b/drivers/char/tpm/tpm_eventlog.c
@@ -0,0 +1,419 @@
+/*
+ * Copyright (C) 2005, 2012 IBM Corporation
+ *
+ * Authors:
+ *	Kent Yoder <key@linux.vnet.ibm.com>
+ *	Seiji Munetoh <munetoh@jp.ibm.com>
+ *	Stefan Berger <stefanb@us.ibm.com>
+ *	Reiner Sailer <sailer@watson.ibm.com>
+ *	Kylene Hall <kjhall@us.ibm.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * Access to the eventlog created by a system's firmware / BIOS
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/seq_file.h>
+#include <linux/fs.h>
+#include <linux/security.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "tpm.h"
+#include "tpm_eventlog.h"
+
+
+static const char* tcpa_event_type_strings[] = {
+	"PREBOOT",
+	"POST CODE",
+	"",
+	"NO ACTION",
+	"SEPARATOR",
+	"ACTION",
+	"EVENT TAG",
+	"S-CRTM Contents",
+	"S-CRTM Version",
+	"CPU Microcode",
+	"Platform Config Flags",
+	"Table of Devices",
+	"Compact Hash",
+	"IPL",
+	"IPL Partition Data",
+	"Non-Host Code",
+	"Non-Host Config",
+	"Non-Host Info"
+};
+
+static const char* tcpa_pc_event_id_strings[] = {
+	"",
+	"SMBIOS",
+	"BIS Certificate",
+	"POST BIOS ",
+	"ESCD ",
+	"CMOS",
+	"NVRAM",
+	"Option ROM",
+	"Option ROM config",
+	"",
+	"Option ROM microcode ",
+	"S-CRTM Version",
+	"S-CRTM Contents ",
+	"POST Contents ",
+	"Table of Devices",
+};
+
+/* returns pointer to start of pos. entry of tcg log */
+static void *tpm_bios_measurements_start(struct seq_file *m, loff_t *pos)
+{
+	loff_t i;
+	struct tpm_bios_log *log = m->private;
+	void *addr = log->bios_event_log;
+	void *limit = log->bios_event_log_end;
+	struct tcpa_event *event;
+
+	/* read over *pos measurements */
+	for (i = 0; i < *pos; i++) {
+		event = addr;
+
+		if ((addr + sizeof(struct tcpa_event)) < limit) {
+			if (event->event_type == 0 && event->event_size == 0)
+				return NULL;
+			addr += sizeof(struct tcpa_event) + event->event_size;
+		}
+	}
+
+	/* now check if current entry is valid */
+	if ((addr + sizeof(struct tcpa_event)) >= limit)
+		return NULL;
+
+	event = addr;
+
+	if ((event->event_type == 0 && event->event_size == 0) ||
+	    ((addr + sizeof(struct tcpa_event) + event->event_size) >= limit))
+		return NULL;
+
+	return addr;
+}
+
+static void *tpm_bios_measurements_next(struct seq_file *m, void *v,
+					loff_t *pos)
+{
+	struct tcpa_event *event = v;
+	struct tpm_bios_log *log = m->private;
+	void *limit = log->bios_event_log_end;
+
+	v += sizeof(struct tcpa_event) + event->event_size;
+
+	/* now check if current entry is valid */
+	if ((v + sizeof(struct tcpa_event)) >= limit)
+		return NULL;
+
+	event = v;
+
+	if (event->event_type == 0 && event->event_size == 0)
+		return NULL;
+
+	if ((event->event_type == 0 && event->event_size == 0) ||
+	    ((v + sizeof(struct tcpa_event) + event->event_size) >= limit))
+		return NULL;
+
+	(*pos)++;
+	return v;
+}
+
+static void tpm_bios_measurements_stop(struct seq_file *m, void *v)
+{
+}
+
+static int get_event_name(char *dest, struct tcpa_event *event,
+			unsigned char * event_entry)
+{
+	const char *name = "";
+	/* 41 so there is room for 40 data and 1 nul */
+	char data[41] = "";
+	int i, n_len = 0, d_len = 0;
+	struct tcpa_pc_event *pc_event;
+
+	switch(event->event_type) {
+	case PREBOOT:
+	case POST_CODE:
+	case UNUSED:
+	case NO_ACTION:
+	case SCRTM_CONTENTS:
+	case SCRTM_VERSION:
+	case CPU_MICROCODE:
+	case PLATFORM_CONFIG_FLAGS:
+	case TABLE_OF_DEVICES:
+	case COMPACT_HASH:
+	case IPL:
+	case IPL_PARTITION_DATA:
+	case NONHOST_CODE:
+	case NONHOST_CONFIG:
+	case NONHOST_INFO:
+		name = tcpa_event_type_strings[event->event_type];
+		n_len = strlen(name);
+		break;
+	case SEPARATOR:
+	case ACTION:
+		if (MAX_TEXT_EVENT > event->event_size) {
+			name = event_entry;
+			n_len = event->event_size;
+		}
+		break;
+	case EVENT_TAG:
+		pc_event = (struct tcpa_pc_event *)event_entry;
+
+		/* ToDo Row data -> Base64 */
+
+		switch (pc_event->event_id) {
+		case SMBIOS:
+		case BIS_CERT:
+		case CMOS:
+		case NVRAM:
+		case OPTION_ROM_EXEC:
+		case OPTION_ROM_CONFIG:
+		case S_CRTM_VERSION:
+			name = tcpa_pc_event_id_strings[pc_event->event_id];
+			n_len = strlen(name);
+			break;
+		/* hash data */
+		case POST_BIOS_ROM:
+		case ESCD:
+		case OPTION_ROM_MICROCODE:
+		case S_CRTM_CONTENTS:
+		case POST_CONTENTS:
+			name = tcpa_pc_event_id_strings[pc_event->event_id];
+			n_len = strlen(name);
+			for (i = 0; i < 20; i++)
+				d_len += sprintf(&data[2*i], "%02x",
+						pc_event->event_data[i]);
+			break;
+		default:
+			break;
+		}
+	default:
+		break;
+	}
+
+	return snprintf(dest, MAX_TEXT_EVENT, "[%.*s%.*s]",
+			n_len, name, d_len, data);
+
+}
+
+static int tpm_binary_bios_measurements_show(struct seq_file *m, void *v)
+{
+	struct tcpa_event *event = v;
+	char *data = v;
+	int i;
+
+	for (i = 0; i < sizeof(struct tcpa_event) + event->event_size; i++)
+		seq_putc(m, data[i]);
+
+	return 0;
+}
+
+static int tpm_bios_measurements_release(struct inode *inode,
+					 struct file *file)
+{
+	struct seq_file *seq = file->private_data;
+	struct tpm_bios_log *log = seq->private;
+
+	if (log) {
+		kfree(log->bios_event_log);
+		kfree(log);
+	}
+
+	return seq_release(inode, file);
+}
+
+static int tpm_ascii_bios_measurements_show(struct seq_file *m, void *v)
+{
+	int len = 0;
+	int i;
+	char *eventname;
+	struct tcpa_event *event = v;
+	unsigned char *event_entry =
+	    (unsigned char *) (v + sizeof(struct tcpa_event));
+
+	eventname = kmalloc(MAX_TEXT_EVENT, GFP_KERNEL);
+	if (!eventname) {
+		printk(KERN_ERR "%s: ERROR - No Memory for event name\n ",
+		       __func__);
+		return -EFAULT;
+	}
+
+	seq_printf(m, "%2d ", event->pcr_index);
+
+	/* 2nd: SHA1 */
+	for (i = 0; i < 20; i++)
+		seq_printf(m, "%02x", event->pcr_value[i]);
+
+	/* 3rd: event type identifier */
+	seq_printf(m, " %02x", event->event_type);
+
+	len += get_event_name(eventname, event, event_entry);
+
+	/* 4th: eventname <= max + \'0' delimiter */
+	seq_printf(m, " %s\n", eventname);
+
+	kfree(eventname);
+	return 0;
+}
+
+static const struct seq_operations tpm_ascii_b_measurments_seqops = {
+	.start = tpm_bios_measurements_start,
+	.next = tpm_bios_measurements_next,
+	.stop = tpm_bios_measurements_stop,
+	.show = tpm_ascii_bios_measurements_show,
+};
+
+static const struct seq_operations tpm_binary_b_measurments_seqops = {
+	.start = tpm_bios_measurements_start,
+	.next = tpm_bios_measurements_next,
+	.stop = tpm_bios_measurements_stop,
+	.show = tpm_binary_bios_measurements_show,
+};
+
+static int tpm_ascii_bios_measurements_open(struct inode *inode,
+					    struct file *file)
+{
+	int err;
+	struct tpm_bios_log *log;
+	struct seq_file *seq;
+
+	log = kzalloc(sizeof(struct tpm_bios_log), GFP_KERNEL);
+	if (!log)
+		return -ENOMEM;
+
+	if ((err = read_log(log)))
+		goto out_free;
+
+	/* now register seq file */
+	err = seq_open(file, &tpm_ascii_b_measurments_seqops);
+	if (!err) {
+		seq = file->private_data;
+		seq->private = log;
+	} else {
+		goto out_free;
+	}
+
+out:
+	return err;
+out_free:
+	kfree(log->bios_event_log);
+	kfree(log);
+	goto out;
+}
+
+static const struct file_operations tpm_ascii_bios_measurements_ops = {
+	.open = tpm_ascii_bios_measurements_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = tpm_bios_measurements_release,
+};
+
+static int tpm_binary_bios_measurements_open(struct inode *inode,
+					     struct file *file)
+{
+	int err;
+	struct tpm_bios_log *log;
+	struct seq_file *seq;
+
+	log = kzalloc(sizeof(struct tpm_bios_log), GFP_KERNEL);
+	if (!log)
+		return -ENOMEM;
+
+	if ((err = read_log(log)))
+		goto out_free;
+
+	/* now register seq file */
+	err = seq_open(file, &tpm_binary_b_measurments_seqops);
+	if (!err) {
+		seq = file->private_data;
+		seq->private = log;
+	} else {
+		goto out_free;
+	}
+
+out:
+	return err;
+out_free:
+	kfree(log->bios_event_log);
+	kfree(log);
+	goto out;
+}
+
+static const struct file_operations tpm_binary_bios_measurements_ops = {
+	.open = tpm_binary_bios_measurements_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = tpm_bios_measurements_release,
+};
+
+static int is_bad(void *p)
+{
+	if (!p)
+		return 1;
+	if (IS_ERR(p) && (PTR_ERR(p) != -ENODEV))
+		return 1;
+	return 0;
+}
+
+struct dentry **tpm_bios_log_setup(char *name)
+{
+	struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;
+
+	tpm_dir = securityfs_create_dir(name, NULL);
+	if (is_bad(tpm_dir))
+		goto out;
+
+	bin_file =
+	    securityfs_create_file("binary_bios_measurements",
+				   S_IRUSR | S_IRGRP, tpm_dir, NULL,
+				   &tpm_binary_bios_measurements_ops);
+	if (is_bad(bin_file))
+		goto out_tpm;
+
+	ascii_file =
+	    securityfs_create_file("ascii_bios_measurements",
+				   S_IRUSR | S_IRGRP, tpm_dir, NULL,
+				   &tpm_ascii_bios_measurements_ops);
+	if (is_bad(ascii_file))
+		goto out_bin;
+
+	ret = kmalloc(3 * sizeof(struct dentry *), GFP_KERNEL);
+	if (!ret)
+		goto out_ascii;
+
+	ret[0] = ascii_file;
+	ret[1] = bin_file;
+	ret[2] = tpm_dir;
+
+	return ret;
+
+out_ascii:
+	securityfs_remove(ascii_file);
+out_bin:
+	securityfs_remove(bin_file);
+out_tpm:
+	securityfs_remove(tpm_dir);
+out:
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(tpm_bios_log_setup);
+
+void tpm_bios_log_teardown(struct dentry **lst)
+{
+	int i;
+
+	for (i = 0; i < 3; i++)
+		securityfs_remove(lst[i]);
+}
+EXPORT_SYMBOL_GPL(tpm_bios_log_teardown);
+MODULE_LICENSE("GPL");