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    Subject[PATCH v2 5/8] char: rpmb: add RPMB simulation device
    Date
    This is simple platform device for used for testing
    rpmb subystem.

    The module currently suppot two configuration options
    1.max_wr_blks: for specifying max blocks that can be written
    in a single command and.
    2. daunits: used to set storage capacity in 128K units.

    Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
    ---
    V2: remove .owner setting, it is set automatically
    drivers/char/rpmb/Kconfig | 10 +
    drivers/char/rpmb/Makefile | 1 +
    drivers/char/rpmb/rpmb_sim.c | 583 +++++++++++++++++++++++++++++++++++++++++++
    3 files changed, 594 insertions(+)
    create mode 100644 drivers/char/rpmb/rpmb_sim.c

    diff --git a/drivers/char/rpmb/Kconfig b/drivers/char/rpmb/Kconfig
    index 6794be9fcc5e..09225080c7fc 100644
    --- a/drivers/char/rpmb/Kconfig
    +++ b/drivers/char/rpmb/Kconfig
    @@ -13,3 +13,13 @@ config RPMB_INTF_DEV
    help
    Say yes here if you want to access RPMB from user space
    via character device interface /dev/rpmb%d
    +
    +
    +config RPMB_SIM
    + tristate "RPMB partition device simulator"
    + default n
    + depends on RPMB
    + select CRYPTO_SHA256
    + select CRYPTO_HMAC
    + help
    + RPMB partition simulator used for testing the RPMB subsystem
    diff --git a/drivers/char/rpmb/Makefile b/drivers/char/rpmb/Makefile
    index b5dc087b1299..81f924fd9a87 100644
    --- a/drivers/char/rpmb/Makefile
    +++ b/drivers/char/rpmb/Makefile
    @@ -1,5 +1,6 @@
    obj-$(CONFIG_RPMB) += rpmb.o
    rpmb-objs += core.o
    rpmb-$(CONFIG_RPMB_INTF_DEV) += cdev.o
    +obj-$(CONFIG_RPMB_SIM) += rpmb_sim.o

    ccflags-y += -D__CHECK_ENDIAN__
    diff --git a/drivers/char/rpmb/rpmb_sim.c b/drivers/char/rpmb/rpmb_sim.c
    new file mode 100644
    index 000000000000..d2caa80eefb0
    --- /dev/null
    +++ b/drivers/char/rpmb/rpmb_sim.c
    @@ -0,0 +1,583 @@
    +/******************************************************************************
    + * This file is provided under a dual BSD/GPLv2 license. When using or
    + * redistributing this file, you may do so under either license.
    + *
    + * GPL LICENSE SUMMARY
    + *
    + * Copyright(c) 2016 Intel Corporation. All rights reserved.
    + *
    + * This program is free software; you can redistribute it and/or modify
    + * it under the terms of version 2 of the GNU General Public License as
    + * published by the Free Software Foundation.
    + *
    + * This program is distributed in the hope that it will be useful, but
    + * WITHOUT ANY WARRANTY; without even the implied warranty of
    + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    + * General Public License for more details.
    + *
    + * The full GNU General Public License is included in this distribution
    + * in the file called LICENSE.GPL.
    + *
    + * Contact Information:
    + * Intel Corporation.
    + * linux-mei@linux.intel.com
    + * http://www.intel.com
    + *
    + * BSD LICENSE
    + *
    + * Copyright(c) 2016 Intel Corporation. All rights reserved.
    + * All rights reserved.
    + *
    + * Redistribution and use in source and binary forms, with or without
    + * modification, are permitted provided that the following conditions
    + * are met:
    + *
    + * * Redistributions of source code must retain the above copyright
    + * notice, this list of conditions and the following disclaimer.
    + * * Redistributions in binary form must reproduce the above copyright
    + * notice, this list of conditions and the following disclaimer in
    + * the documentation and/or other materials provided with the
    + * distribution.
    + * * Neither the name Intel Corporation nor the names of its
    + * contributors may be used to endorse or promote products derived
    + * from this software without specific prior written permission.
    + *
    + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    + *
    + *****************************************************************************/
    +#include <linux/module.h>
    +#include <linux/slab.h>
    +#include <linux/platform_device.h>
    +#include <linux/device.h>
    +#include <crypto/hash.h>
    +#include <linux/scatterlist.h>
    +#include <linux/sizes.h>
    +
    +#include <linux/rpmb.h>
    +
    +static const char id[] = "RPMB:SIM";
    +#define CAPACITY_UNIT SZ_128K
    +#define CAPACITY_MIN SZ_128K
    +#define CAPACITY_MAX SZ_16M
    +#define BLK_UNIT SZ_256
    +
    +static unsigned int max_wr_blks = 1;
    +module_param(max_wr_blks, uint, 0644);
    +MODULE_PARM_DESC(max_wr_blks,
    + "max blocks that can be written in a single command (default: 1)");
    +
    +static unsigned int daunits = 1;
    +module_param(daunits, uint, 0644);
    +MODULE_PARM_DESC(daunits,
    + "number of data area units of 128K (default: 1)");
    +
    +struct blk {
    + u8 data[BLK_UNIT];
    +};
    +
    +/**
    + * struct rpmb_sim_dev
    + *
    + * @dev: back pointer to the platform device
    + * @rdev: rpmb device
    + * @auth_key: Authentication key register which is used to authenticate
    + * accesses when MAC is calculated;
    + * @auth_key_set: true if auth key was set
    + * @write_counter: Counter value for the total amount of successful
    + * authenticated data write requests made by the host.
    + * The initial value of this register after production is 00000000h.
    + * The value will be incremented by one along with each successful
    + * programming access. The value cannot be reset. After the counter
    + * has reached the maximum value of FFFFFFFFh,
    + * it will not be incremented anymore (overflow prevention)
    + * @hash_tfm: hmac(sha256) tfm
    + *
    + * @capacity: size of the partition in bytes multiple of 128K
    + * @blkcnt: block count
    + * @da: data area in blocks
    + */
    +struct rpmb_sim_dev {
    + struct device *dev;
    + struct rpmb_dev *rdev;
    + u8 auth_key[32];
    + bool auth_key_set;
    + u32 write_counter;
    + struct crypto_shash *hash_tfm;
    +
    + size_t capacity;
    + size_t blkcnt;
    + struct blk *da;
    +};
    +
    +static __be16 op_result(struct rpmb_sim_dev *rsdev, u16 result)
    +{
    + if (!rsdev->auth_key_set)
    + return cpu_to_be16(RPMB_ERR_NO_KEY);
    +
    + if (rsdev->write_counter == 0xFFFFFFFF)
    + result |= RPMB_ERR_COUNTER_EXPIRED;
    +
    + return cpu_to_be16(result);
    +}
    +
    +static __be16 req_to_resp(u16 req)
    +{
    + return cpu_to_be16(RPMB_REQ2RESP(req));
    +}
    +
    +static int rpmb_sim_calc_hmac(struct rpmb_sim_dev *rsdev,
    + struct rpmb_frame *frames,
    + unsigned int blks, u8 *mac)
    +{
    + SHASH_DESC_ON_STACK(desc, rsdev->hash_tfm);
    + int i;
    + int ret;
    +
    + desc->tfm = rsdev->hash_tfm;
    + desc->flags = 0;
    +
    + ret = crypto_shash_init(desc);
    + if (ret)
    + goto out;
    +
    + for (i = 0; i < blks; i++) {
    + ret = crypto_shash_update(desc, frames[i].data, hmac_data_len);
    + if (ret)
    + goto out;
    + }
    + ret = crypto_shash_final(desc, mac);
    +out:
    + if (ret)
    + dev_err(rsdev->dev, "digest error = %d", ret);
    +
    + return ret;
    +}
    +
    +static int rpmb_op_not_programmed(struct rpmb_sim_dev *rsdev,
    + struct rpmb_data *rpmbd)
    +{
    + struct rpmb_frame *in_frame, *out_frame;
    + u16 req;
    +
    + in_frame = &rpmbd->in_frames[0];
    + req = be16_to_cpu(in_frame->req_resp);
    +
    + out_frame = &rpmbd->out_frames[0];
    +
    + out_frame->req_resp = req_to_resp(req);
    + out_frame->result = op_result(rsdev, RPMB_ERR_NO_KEY);
    +
    + dev_err(rsdev->dev, "not programmed\n");
    +
    + return 0;
    +}
    +
    +static int rpmb_op_program_key(struct rpmb_sim_dev *rsdev,
    + struct rpmb_data *rpmbd)
    +{
    + struct rpmb_frame *in_frame, *out_frame;
    + u16 req;
    + int ret;
    + u16 err = RPMB_ERR_OK;
    +
    + in_frame = rpmbd->in_frames;
    + req = be16_to_cpu(in_frame[0].req_resp);
    +
    + if (req != RPMB_PROGRAM_KEY)
    + return -EINVAL;
    +
    + if (rsdev->auth_key_set) {
    + dev_err(rsdev->dev, "key allread set\n");
    + err = RPMB_ERR_WRITE;
    + goto out;
    + }
    +
    + ret = crypto_shash_setkey(rsdev->hash_tfm, in_frame[0].key_mac, 32);
    + if (ret) {
    + dev_err(rsdev->dev, "set key failed = %d\n", ret);
    + err = RPMB_ERR_GENERAL;
    + goto out;
    + }
    +
    + dev_dbg(rsdev->dev, "digest size %u",
    + crypto_shash_digestsize(rsdev->hash_tfm));
    +
    + memcpy(rsdev->auth_key, in_frame[0].key_mac, 32);
    + rsdev->auth_key_set = true;
    +out:
    + out_frame = rpmbd->out_frames;
    + memset(out_frame, 0, sizeof(struct rpmb_frame));
    +
    + out_frame[0].req_resp = req_to_resp(req);
    + out_frame[0].result = op_result(rsdev, err);
    +
    + return 0;
    +}
    +
    +
    +static int rpmb_op_get_wr_conter(struct rpmb_sim_dev *rsdev,
    + struct rpmb_data *rpmbd)
    +{
    + struct rpmb_frame *in_frame, *out_frame;
    + u16 req;
    + u16 err;
    +
    + in_frame = rpmbd->in_frames;
    + req = be16_to_cpu(in_frame[0].req_resp);
    +
    + if (req != RPMB_GET_WRITE_COUNTER)
    + return -EINVAL;
    +
    + out_frame = rpmbd->out_frames;
    + memset(out_frame, 0, sizeof(struct rpmb_frame));
    +
    + out_frame[0].req_resp = req_to_resp(req);
    + out_frame[0].write_counter = cpu_to_be32(rsdev->write_counter);
    + memcpy(out_frame[0].nonce, in_frame[0].nonce, 16);
    +
    + err = RPMB_ERR_OK;
    + out_frame[0].result = op_result(rsdev, err);
    +
    + if (rpmb_sim_calc_hmac(rsdev, out_frame, 1, out_frame->key_mac))
    + err = RPMB_ERR_READ;
    +
    + out_frame[0].result = op_result(rsdev, err);
    +
    + return 0;
    +}
    +
    +static int rpmb_op_write_data(struct rpmb_sim_dev *rsdev,
    + struct rpmb_data *rpmbd)
    +{
    + struct rpmb_frame *in_frame, *out_frame;
    + u8 mac[32];
    + u16 req, err, addr, blks;
    + unsigned int i;
    + int ret = 0;
    +
    + in_frame = rpmbd->in_frames;
    + req = be16_to_cpu(in_frame[0].req_resp);
    +
    + if (req != RPMB_WRITE_DATA)
    + return -EINVAL;
    +
    +
    + if (rsdev->write_counter == 0xFFFFFFFF) {
    + err = RPMB_ERR_WRITE;
    + goto out;
    + }
    +
    + blks = be16_to_cpu(in_frame[0].block_count);
    + if (blks == 0 || blks > rpmbd->in_frames_cnt) {
    + ret = -EINVAL;
    + err = RPMB_ERR_GENERAL;
    + goto out;
    + }
    +
    + if (blks > max_wr_blks) {
    + err = RPMB_ERR_WRITE;
    + goto out;
    + }
    +
    +
    + addr = be16_to_cpu(in_frame[0].addr);
    + if (addr >= rsdev->blkcnt) {
    + err = RPMB_ERR_ADDRESS;
    + goto out;
    + }
    +
    + if (rpmb_sim_calc_hmac(rsdev, in_frame, blks, mac)) {
    + err = RPMB_ERR_AUTH;
    + goto out;
    + }
    +
    + /* mac is in the last frame */
    + if (memcmp(mac, in_frame[blks - 1].key_mac, sizeof(mac)) != 0) {
    + err = RPMB_ERR_AUTH;
    + goto out;
    + }
    +
    + if (be32_to_cpu(in_frame[0].write_counter) != rsdev->write_counter) {
    + err = RPMB_ERR_COUNTER;
    + goto out;
    + }
    +
    + if (addr + blks > rsdev->blkcnt) {
    + err = RPMB_ERR_WRITE;
    + goto out;
    + }
    +
    + err = RPMB_ERR_OK;
    + for (i = 0; i < blks; i++)
    + memcpy(rsdev->da[addr + i].data, in_frame[i].data, BLK_UNIT);
    +
    + rsdev->write_counter++;
    +
    +out:
    + out_frame = &rpmbd->out_frames[0];
    + memset(out_frame, 0, sizeof(struct rpmb_frame));
    +
    + if (err == RPMB_ERR_OK) {
    + out_frame[0].write_counter = cpu_to_be32(rsdev->write_counter);
    + memcpy(out_frame[0].key_mac, mac, sizeof(mac));
    + }
    + out_frame[0].req_resp = req_to_resp(req);
    + out_frame[0].result = op_result(rsdev, err);
    +
    + return ret;
    +}
    +
    +static int rpmb_op_read_data(struct rpmb_sim_dev *rsdev,
    + struct rpmb_data *rpmbd)
    +{
    + struct rpmb_frame *in_frame, *out_frame;
    + u8 mac[32];
    + u16 req, err, addr, blks;
    + unsigned int i;
    + int ret;
    +
    + in_frame = rpmbd->in_frames;
    + req = be16_to_cpu(in_frame[0].req_resp);
    + if (req != RPMB_READ_DATA)
    + return -EINVAL;
    +
    +
    + out_frame = rpmbd->out_frames;
    +
    + blks = be16_to_cpu(in_frame[0].block_count);
    + if (blks == 0 || blks > rpmbd->out_frames_cnt) {
    + ret = -EINVAL;
    + memset(out_frame, 0, sizeof(struct rpmb_frame));
    + err = RPMB_ERR_READ;
    + goto out;
    + }
    +
    + ret = 0;
    + memset(out_frame, 0, sizeof(struct rpmb_frame) * blks);
    +
    + addr = be16_to_cpu(in_frame[0].addr);
    + if (addr >= rsdev->blkcnt) {
    + err = RPMB_ERR_ADDRESS;
    + goto out;
    + }
    +
    + if (addr + blks > rsdev->blkcnt) {
    + err = RPMB_ERR_READ;
    + goto out;
    + }
    +
    + for (i = 0; i < blks; i++) {
    + memcpy(out_frame[i].data, rsdev->da[addr + i].data, BLK_UNIT);
    + memcpy(out_frame[i].nonce, in_frame[0].nonce, 16);
    + out_frame[i].req_resp = req_to_resp(req);
    + out_frame[i].addr = in_frame[0].addr;
    + out_frame[i].block_count = cpu_to_be16(blks);
    + }
    +
    + if (rpmb_sim_calc_hmac(rsdev, out_frame, blks, mac)) {
    + err = RPMB_ERR_AUTH;
    + goto out;
    + }
    +
    + memcpy(out_frame[blks - 1].key_mac, mac, sizeof(mac));
    +
    + err = RPMB_ERR_OK;
    +out:
    +
    + /* FIXME: not sure if this has to be updated in each frame */
    + out_frame[0].result = op_result(rsdev, err);
    +
    +
    + return ret;
    +}
    +
    +static int rpmb_sim_sequence(struct rpmb_sim_dev *rsdev,
    + struct rpmb_data *rpmbd)
    +{
    + u16 type;
    + int ret;
    +
    + type = rpmbd->req_type;
    +
    + if (rpmbd->out_frames == NULL || rpmbd->in_frames == NULL ||
    + rpmbd->out_frames_cnt == 0 || rpmbd->in_frames_cnt == 0)
    + return -EINVAL;
    +
    + if (rsdev->auth_key_set == false && type != RPMB_PROGRAM_KEY)
    + return rpmb_op_not_programmed(rsdev, rpmbd);
    +
    + switch (type) {
    + case RPMB_PROGRAM_KEY:
    + ret = rpmb_op_program_key(rsdev, rpmbd);
    + break;
    + case RPMB_WRITE_DATA:
    + ret = rpmb_op_write_data(rsdev, rpmbd);
    + break;
    + case RPMB_GET_WRITE_COUNTER:
    + ret = rpmb_op_get_wr_conter(rsdev, rpmbd);
    + break;
    + case RPMB_READ_DATA:
    + ret = rpmb_op_read_data(rsdev, rpmbd);
    + break;
    + default:
    + ret = -EINVAL;
    + goto out;
    + }
    +out:
    + return ret;
    +}
    +
    +static int rpmb_sim_send_rpmb_req(struct device *dev, struct rpmb_data *rpmbd)
    +{
    + struct platform_device *pdev = to_platform_device(dev);
    + struct rpmb_sim_dev *rsdev = platform_get_drvdata(pdev);
    +
    + if (!rsdev)
    + return -EINVAL;
    +
    + if (!rpmbd)
    + return -EINVAL;
    +
    + return rpmb_sim_sequence(rsdev, rpmbd);
    +}
    +
    +static struct rpmb_ops rpmb_sim_ops = {
    + .send_rpmb_req = rpmb_sim_send_rpmb_req,
    + .type = RPMB_TYPE_EMMC,
    +};
    +
    +static int rpmb_sim_hmac_256_alloc(struct rpmb_sim_dev *rsdev)
    +{
    + struct crypto_shash *hash_tfm;
    +
    + hash_tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
    + if (IS_ERR(hash_tfm))
    + return PTR_ERR(hash_tfm);
    +
    + rsdev->hash_tfm = hash_tfm;
    +
    + dev_dbg(rsdev->dev, "hamac(sha256) registered\n");
    + return 0;
    +}
    +
    +static void rpmb_sim_hmac_256_free(struct rpmb_sim_dev *rsdev)
    +{
    + if (rsdev->hash_tfm)
    + crypto_free_shash(rsdev->hash_tfm);
    +
    + rsdev->hash_tfm = NULL;
    +}
    +
    +static int rpmb_sim_probe(struct platform_device *pdev)
    +{
    + struct rpmb_sim_dev *rsdev;
    + int ret;
    +
    + rsdev = kzalloc(sizeof(struct rpmb_sim_dev), GFP_KERNEL);
    + if (!rsdev)
    + return -ENOMEM;
    +
    + rsdev->dev = &pdev->dev;
    +
    + ret = rpmb_sim_hmac_256_alloc(rsdev);
    + if (ret)
    + goto err;
    +
    + rsdev->capacity = CAPACITY_UNIT * daunits;
    + rsdev->blkcnt = rsdev->capacity / BLK_UNIT;
    + rsdev->da = kzalloc(rsdev->capacity, GFP_KERNEL);
    + if (!rsdev->da) {
    + ret = -ENOMEM;
    + goto err;
    + }
    +
    + rpmb_sim_ops.dev_id_len = strlen(id);
    + rpmb_sim_ops.dev_id = id;
    + rpmb_sim_ops.reliable_wr_cnt = max_wr_blks;
    +
    + rsdev->rdev = rpmb_dev_register(rsdev->dev, &rpmb_sim_ops);
    + if (IS_ERR(rsdev->rdev)) {
    + ret = PTR_ERR(rsdev->rdev);
    + goto err;
    + }
    +
    + dev_info(&pdev->dev, "registered RPMB capacity = %zu of %zu blocks\n",
    + rsdev->capacity, rsdev->blkcnt);
    +
    + platform_set_drvdata(pdev, rsdev);
    +
    + return 0;
    +err:
    + rpmb_sim_hmac_256_free(rsdev);
    + if (rsdev)
    + kfree(rsdev->da);
    + kfree(rsdev);
    + return ret;
    +}
    +
    +static int rpmb_sim_remove(struct platform_device *pdev)
    +{
    + struct rpmb_sim_dev *rsdev;
    +
    + rsdev = platform_get_drvdata(pdev);
    +
    + rpmb_dev_unregister(rsdev->dev);
    +
    + platform_set_drvdata(pdev, NULL);
    +
    + rpmb_sim_hmac_256_free(rsdev);
    +
    + kfree(rsdev->da);
    + kfree(rsdev);
    + return 0;
    +}
    +
    +static struct platform_driver rpmb_sim_driver = {
    + .driver = {
    + .name = "rpmb_sim",
    + },
    + .probe = rpmb_sim_probe,
    + .remove = rpmb_sim_remove,
    +};
    +
    +static struct platform_device *rpmb_sim_pdev;
    +
    +static int __init rpmb_sim_init(void)
    +{
    + int ret;
    +
    + rpmb_sim_pdev = platform_device_register_simple("rpmb_sim", -1,
    + NULL, 0);
    +
    + if (IS_ERR(rpmb_sim_pdev))
    + return PTR_ERR(rpmb_sim_pdev);
    +
    + ret = platform_driver_register(&rpmb_sim_driver);
    + if (ret)
    + platform_device_unregister(rpmb_sim_pdev);
    +
    + return ret;
    +}
    +
    +static void __exit rpmb_sim_exit(void)
    +{
    + platform_device_unregister(rpmb_sim_pdev);
    + platform_driver_unregister(&rpmb_sim_driver);
    +}
    +
    +module_init(rpmb_sim_init);
    +module_exit(rpmb_sim_exit);
    +
    +MODULE_AUTHOR("Tomas Winkler <tomas.winkler@intel.com");
    +MODULE_LICENSE("Dual BSD/GPL");
    +MODULE_ALIAS("platform:rpmb_sim");
    --
    2.4.3
    \
     
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      Last update: 2016-04-04 14:01    [W:3.002 / U:0.320 seconds]
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