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");