Re: [PATCH 2/4] Add MMC Password Protection (lock/unlock) supportV9: mmc_key_retention.diff

From: Anderson Briglia
Date: Wed Jan 03 2007 - 07:04:28 EST



Implement key retention operations.

Signed-off-by: Carlos Eduardo Aguiar <carlos.aguiar@xxxxxxxxxxx>
Signed-off-by: Anderson Lizardo <anderson.lizardo@xxxxxxxxxxx>
Signed-off-by: Anderson Briglia <anderson.briglia@xxxxxxxxxxx>

Index: linux-linus-2.6/drivers/mmc/Kconfig
===================================================================
--- linux-linus-2.6.orig/drivers/mmc/Kconfig 2007-01-03 07:39:53.000000000 -0400
+++ linux-linus-2.6/drivers/mmc/Kconfig 2007-01-03 07:57:40.000000000 -0400
@@ -19,6 +19,19 @@ config MMC_DEBUG
This is an option for use by developers; most people should
say N here. This enables MMC core and driver debugging.

+config MMC_PASSWORDS
+ boolean "MMC card lock/unlock passwords (EXPERIMENTAL)"
+ depends on MMC && EXPERIMENTAL
+ select KEYS
+ help
+ Say Y here to enable the use of passwords to lock and unlock
+ MMC cards. This uses the access key retention support, using
+ request_key to look up the key associated with each card.
+
+ For example, if you have an MMC card that was locked using
+ Symbian OS on your cell phone, you won't be able to read it
+ on Linux without this support.
+
config MMC_BLOCK
tristate "MMC block device driver"
depends on MMC && BLOCK
Index: linux-linus-2.6/drivers/mmc/mmc.h
===================================================================
--- linux-linus-2.6.orig/drivers/mmc/mmc.h 2007-01-03 07:39:53.000000000 -0400
+++ linux-linus-2.6/drivers/mmc/mmc.h 2007-01-03 07:57:40.000000000 -0400
@@ -19,6 +19,14 @@ int mmc_add_host_sysfs(struct mmc_host *
void mmc_remove_host_sysfs(struct mmc_host *host);
void mmc_free_host_sysfs(struct mmc_host *host);

+/* core-internal data */
+extern struct key_type mmc_key_type;
+struct mmc_key_payload {
+ struct rcu_head rcu; /* RCU destructor */
+ unsigned short datalen; /* length of this data */
+ char data[0]; /* actual data */
+};
+
int mmc_schedule_work(struct work_struct *work);
int mmc_schedule_delayed_work(struct delayed_work *work, unsigned long delay);
void mmc_flush_scheduled_work(void);
Index: linux-linus-2.6/drivers/mmc/mmc_sysfs.c
===================================================================
--- linux-linus-2.6.orig/drivers/mmc/mmc_sysfs.c 2007-01-03 07:57:37.000000000 -0400
+++ linux-linus-2.6/drivers/mmc/mmc_sysfs.c 2007-01-03 07:57:40.000000000 -0400
@@ -2,6 +2,8 @@
* linux/drivers/mmc/mmc_sysfs.c
*
* Copyright (C) 2003 Russell King, All Rights Reserved.
+ * MMC password protection (C) 2006 Instituto Nokia de Tecnologia (INdT),
+ * All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -14,6 +16,7 @@
#include <linux/device.h>
#include <linux/idr.h>
#include <linux/workqueue.h>
+#include <linux/key.h>

#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
@@ -266,6 +269,70 @@ static struct class mmc_host_class = {
static DEFINE_IDR(mmc_host_idr);
static DEFINE_SPINLOCK(mmc_host_lock);

+#ifdef CONFIG_MMC_PASSWORDS
+
+#define MMC_KEYLEN_MAXBYTES 32
+
+static int mmc_key_instantiate(struct key *key, const void *data, size_t datalen)
+{
+ struct mmc_key_payload *mpayload;
+ int ret;
+
+ ret = -EINVAL;
+ if (datalen <= 0 || datalen > MMC_KEYLEN_MAXBYTES || !data) {
+ pr_debug("Invalid data\n");
+ goto error;
+ }
+
+ ret = key_payload_reserve(key, datalen);
+ if (ret < 0) {
+ pr_debug("ret = %d\n", ret);
+ goto error;
+ }
+
+ ret = -ENOMEM;
+ mpayload = kmalloc(sizeof(*mpayload) + datalen, GFP_KERNEL);
+ if (!mpayload) {
+ pr_debug("Unable to allocate mpayload structure\n");
+ goto error;
+ }
+ mpayload->datalen = datalen;
+ memcpy(mpayload->data, data, datalen);
+
+ rcu_assign_pointer(key->payload.data, mpayload);
+
+ /* ret = 0 if there is no error */
+ ret = 0;
+
+error:
+ return ret;
+}
+
+static int mmc_key_match(const struct key *key, const void *description)
+{
+ return strcmp(key->description, description) == 0;
+}
+
+/*
+ * dispose of the data dangling from the corpse of a mmc key
+ */
+static void mmc_key_destroy(struct key *key)
+{
+ struct mmc_key_payload *mpayload = key->payload.data;
+
+ kfree(mpayload);
+}
+
+struct key_type mmc_key_type = {
+ .name = "mmc",
+ .def_datalen = MMC_KEYLEN_MAXBYTES,
+ .instantiate = mmc_key_instantiate,
+ .match = mmc_key_match,
+ .destroy = mmc_key_destroy,
+};
+
+#endif
+
/*
* Internal function. Allocate a new MMC host.
*/
@@ -355,16 +422,31 @@ static int __init mmc_init(void)
return -ENOMEM;

ret = bus_register(&mmc_bus_type);
- if (ret == 0) {
- ret = class_register(&mmc_host_class);
- if (ret)
- bus_unregister(&mmc_bus_type);
+ if (ret)
+ goto error_bus;
+ ret = class_register(&mmc_host_class);
+ if (ret)
+ goto error_class;
+#ifdef CONFIG_MMC_PASSWORDS
+ ret = register_key_type(&mmc_key_type);
+ if (ret) {
+ class_unregister(&mmc_host_class);
+ goto error_class;
}
+#endif
+ return 0;
+
+error_class:
+ bus_unregister(&mmc_bus_type);
+error_bus:
return ret;
}

static void __exit mmc_exit(void)
{
+#ifdef CONFIG_MMC_PASSWORDS
+ unregister_key_type(&mmc_key_type);
+#endif
class_unregister(&mmc_host_class);
bus_unregister(&mmc_bus_type);
destroy_workqueue(workqueue);