[U-Boot] [PATCH v3 15/20] tee: add sandbox driver
Simon Glass
sjg at chromium.org
Fri Sep 14 10:53:56 UTC 2018
Hi Jens,
On 3 September 2018 at 16:47, Jens Wiklander <jens.wiklander at linaro.org> wrote:
> Adds a sandboxtee driver which emulates a generic TEE with the OP-TEE
sandbox tee
> AVB TA.
>
> Signed-off-by: Jens Wiklander <jens.wiklander at linaro.org>
> ---
> drivers/tee/Kconfig | 12 +-
> drivers/tee/Makefile | 1 +
> drivers/tee/optee/Kconfig | 2 +-
> drivers/tee/sandbox.c | 299 ++++++++++++++++++++++++++++++++++++++
> include/sandboxtee.h | 15 ++
> 5 files changed, 326 insertions(+), 3 deletions(-)
> create mode 100644 drivers/tee/sandbox.c
> create mode 100644 include/sandboxtee.h
Reviewed-by: Simon Glass <sjg at chromium.org>
nits below.
>
> diff --git a/drivers/tee/Kconfig b/drivers/tee/Kconfig
> index 835c256e9239..4697b80913d6 100644
> --- a/drivers/tee/Kconfig
> +++ b/drivers/tee/Kconfig
> @@ -1,8 +1,8 @@
> # Generic Trusted Execution Environment Configuration
> config TEE
> bool "Trusted Execution Environment support"
> - depends on ARM && (ARM64 || CPU_V7A)
> - select ARM_SMCCC
> + depends on (ARM && (ARM64 || CPU_V7A)) || SANDBOX
> + select ARM_SMCCC if ARM
> help
> This implements a generic interface towards a Trusted Execution
> Environment (TEE). A TEE is a trusted OS running in some secure
> @@ -14,6 +14,14 @@ if TEE
>
> menu "TEE drivers"
>
> +config SANDBOX_TEE
> + bool "Sandbox TEE emulator"
> + depends on SANDBOX
> + default y
> + help
> + This emulates a generic TEE needed for testing including the AVB
> + TA.
Can you please expand this? What features does it implement? How do
you access it from the U-Boot command line?
> +
> source "drivers/tee/optee/Kconfig"
>
> endmenu
> diff --git a/drivers/tee/Makefile b/drivers/tee/Makefile
> index 19633b60f235..f72c68c09f33 100644
> --- a/drivers/tee/Makefile
> +++ b/drivers/tee/Makefile
> @@ -1,4 +1,5 @@
> # SPDX-License-Identifier: GPL-2.0+
>
> obj-y += tee-uclass.o
> +obj-$(CONFIG_SANDBOX) += sandbox.o
> obj-$(CONFIG_OPTEE) += optee/
> diff --git a/drivers/tee/optee/Kconfig b/drivers/tee/optee/Kconfig
> index dbfa7846a30f..d489834df926 100644
> --- a/drivers/tee/optee/Kconfig
> +++ b/drivers/tee/optee/Kconfig
> @@ -10,7 +10,7 @@ config OPTEE
> handle Remote Procedure Calls (RPC) from OP-TEE needed to
> execute a service. For more information see: https://www.op-tee.org
>
> -if OPTEE
> +if OPTEE || SANDBOX
>
> menu "OP-TEE options"
>
> diff --git a/drivers/tee/sandbox.c b/drivers/tee/sandbox.c
> new file mode 100644
> index 000000000000..cd073497615f
> --- /dev/null
> +++ b/drivers/tee/sandbox.c
> @@ -0,0 +1,299 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2018 Linaro Limited
> + */
> +#include <common.h>
> +#include <dm.h>
> +#include <sandboxtee.h>
Could this go in asm/ ?
> +#include <tee.h>
> +#include <tee/optee_ta_avb.h>
> +
> +/*
> + * The sandbox tee driver tries to emulate a generic TEE with the TA
> + * OPTEE_TA_AVB available.
What is TEE?
What is TA?
Please expand out the names once in this comment so people can see
immediately what you are referring to.
> + */
> +
> +struct ta_entry {
What is this struct for? Please add a comment
> + struct tee_optee_ta_uuid uuid;
> + u32 (*open_session)(uint num_params, struct tee_param *params);
> + u32 (*invoke_func)(u32 func, uint num_params, struct tee_param *params);
> +};
> +
> +#ifdef CONFIG_OPTEE_TA_AVB
> +static u32 get_attr(uint n, uint num_params, struct tee_param *params)
> +{
> + if (n >= num_params)
> + return TEE_PARAM_ATTR_TYPE_NONE;
> +
> + return params[n].attr;
> +}
> +
> +static u32 check_params(u8 p0, u8 p1, u8 p2, u8 p3, uint num_params,
> + struct tee_param *params)
> +{
> + u8 p[] = { p0, p1, p2, p3};
> + uint n;
> +
> + for (n = 0; n < ARRAY_SIZE(p); n++)
> + if (p[n] != get_attr(n, num_params, params))
> + goto bad_params;
> +
> + for (; n < num_params; n++)
> + if (get_attr(n, num_params, params))
> + goto bad_params;
> +
> + return TEE_SUCCESS;
> +
> +bad_params:
> + printf("Bad param attrs\n");
> +
> + return TEE_ERROR_BAD_PARAMETERS;
> +}
> +
> +static u64 ta_avb_rollback_indexes[TA_AVB_MAX_ROLLBACK_LOCATIONS];
> +static u32 ta_avb_lock_state;
> +
> +static u32 ta_avb_open_session(uint num_params, struct tee_param *params)
> +{
> + /*
> + * We don't expect additional parameters when opening a session to
> + * this TA.
> + */
> + return check_params(TEE_PARAM_ATTR_TYPE_NONE, TEE_PARAM_ATTR_TYPE_NONE,
> + TEE_PARAM_ATTR_TYPE_NONE, TEE_PARAM_ATTR_TYPE_NONE,
> + num_params, params);
> +}
> +
> +static u32 ta_avb_invoke_func(u32 func, uint num_params,
> + struct tee_param *params)
> +{
> + u32 res;
> + uint slot;
> + u64 val;
> +
> + switch (func) {
> + case TA_AVB_CMD_READ_ROLLBACK_INDEX:
> + res = check_params(TEE_PARAM_ATTR_TYPE_VALUE_INPUT,
> + TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT,
> + TEE_PARAM_ATTR_TYPE_NONE,
> + TEE_PARAM_ATTR_TYPE_NONE,
> + num_params, params);
> + if (res)
> + return res;
> +
> + slot = params[0].u.value.a;
> + if (slot >= ARRAY_SIZE(ta_avb_rollback_indexes)) {
> + printf("Rollback index slot out of bounds %lu\n", slot);
> + return TEE_ERROR_BAD_PARAMETERS;
> + }
> +
> + val = ta_avb_rollback_indexes[slot];
> + params[1].u.value.a = val >> 32;
> + params[1].u.value.b = val;
> + return TEE_SUCCESS;
> +
> + case TA_AVB_CMD_WRITE_ROLLBACK_INDEX:
> + res = check_params(TEE_PARAM_ATTR_TYPE_VALUE_INPUT,
> + TEE_PARAM_ATTR_TYPE_VALUE_INPUT,
> + TEE_PARAM_ATTR_TYPE_NONE,
> + TEE_PARAM_ATTR_TYPE_NONE,
> + num_params, params);
> + if (res)
> + return res;
> +
> + slot = params[0].u.value.a;
> + if (slot >= ARRAY_SIZE(ta_avb_rollback_indexes)) {
> + printf("Rollback index slot out of bounds %lu\n", slot);
> + return TEE_ERROR_BAD_PARAMETERS;
> + }
> +
> + val = (u64)params[1].u.value.a << 32 | params[1].u.value.b;
> + if (val < ta_avb_rollback_indexes[slot])
> + return TEE_ERROR_SECURITY;
> +
> + ta_avb_rollback_indexes[slot] = val;
> + return TEE_SUCCESS;
> +
> + case TA_AVB_CMD_READ_LOCK_STATE:
> + res = check_params(TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT,
> + TEE_PARAM_ATTR_TYPE_NONE,
> + TEE_PARAM_ATTR_TYPE_NONE,
> + TEE_PARAM_ATTR_TYPE_NONE,
> + num_params, params);
> + if (res)
> + return res;
> +
> + params[0].u.value.a = ta_avb_lock_state;
> + return TEE_SUCCESS;
> +
> + case TA_AVB_CMD_WRITE_LOCK_STATE:
> + res = check_params(TEE_PARAM_ATTR_TYPE_VALUE_INPUT,
> + TEE_PARAM_ATTR_TYPE_NONE,
> + TEE_PARAM_ATTR_TYPE_NONE,
> + TEE_PARAM_ATTR_TYPE_NONE,
> + num_params, params);
> + if (res)
> + return res;
> +
> + if (ta_avb_lock_state != params[0].u.value.a) {
> + ta_avb_lock_state = params[0].u.value.a;
> + memset(ta_avb_rollback_indexes, 0,
> + sizeof(ta_avb_rollback_indexes));
> + }
> +
> + return TEE_SUCCESS;
> +
> + default:
> + return TEE_ERROR_NOT_SUPPORTED;
> + }
> +}
> +#endif /*OPTEE_TA_AVB*/
> +
> +static const struct ta_entry ta_entries[] = {
> +#ifdef CONFIG_OPTEE_TA_AVB
> + { .uuid = TA_AVB_UUID,
> + .open_session = ta_avb_open_session,
> + .invoke_func = ta_avb_invoke_func,
> + },
> +#endif
> +};
> +
> +static void sandbox_tee_get_version(struct udevice *dev,
> + struct tee_version_data *vers)
> +{
> + struct tee_version_data v = {
> + .gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM,
> + };
> +
> + *vers = v;
> +}
> +
> +static int sandbox_tee_close_session(struct udevice *dev, u32 session)
> +{
> + struct sandbox_tee_state *state = dev_get_priv(dev);
> +
> + if (!state->ta || state->session != session)
> + return -EINVAL;
> +
> + state->session = 0;
> + state->ta = NULL;
> +
> + return 0;
> +}
> +
> +static const struct ta_entry *find_ta_entry(u8 uuid[TEE_UUID_LEN])
> +{
> + struct tee_optee_ta_uuid u;
> + uint n;
> +
> + tee_optee_ta_uuid_from_octets(&u, uuid);
> +
> + for (n = 0; n < ARRAY_SIZE(ta_entries); n++)
> + if (!memcmp(&u, &ta_entries[n].uuid, sizeof(u)))
> + return ta_entries + n;
> +
> + return NULL;
> +}
> +
> +static int sandbox_tee_open_session(struct udevice *dev,
> + struct tee_open_session_arg *arg,
> + uint num_params, struct tee_param *params)
> +{
> + struct sandbox_tee_state *state = dev_get_priv(dev);
> + const struct ta_entry *ta;
> +
> + if (state->ta) {
> + printf("A session is already open\n");
> + return -EBUSY;
> + }
> +
> + ta = find_ta_entry(arg->uuid);
> + if (!ta) {
> + printf("Cannot find TA\n");
> + arg->ret = TEE_ERROR_ITEM_NOT_FOUND;
> + arg->ret_origin = TEE_ORIGIN_TEE;
> +
> + return 0;
> + }
> +
> + arg->ret = ta->open_session(num_params, params);
> + arg->ret_origin = TEE_ORIGIN_TRUSTED_APP;
> +
> + if (!arg->ret) {
> + state->ta = (void *)ta;
> + state->session = 1;
> + arg->session = state->session;
> + } else {
> + printf("Cannot open session, TA returns error\n");
> + }
> +
> + return 0;
> +}
> +
> +static int sandbox_tee_invoke_func(struct udevice *dev,
> + struct tee_invoke_arg *arg,
> + uint num_params, struct tee_param *params)
> +{
> + struct sandbox_tee_state *state = dev_get_priv(dev);
> + struct ta_entry *ta = state->ta;
> +
> + if (!arg->session) {
> + printf("Missing session\n");
> + return -EINVAL;
> + }
> +
> + if (!ta) {
> + printf("TA session not available\n");
> + return -EINVAL;
> + }
> +
> + if (arg->session != state->session) {
> + printf("Session mismatch\n");
> + return -EINVAL;
> + }
> +
> + arg->ret = ta->invoke_func(arg->func, num_params, params);
> + arg->ret_origin = TEE_ORIGIN_TRUSTED_APP;
> +
> + return 0;
> +}
> +
> +static int sandbox_tee_shm_register(struct udevice *dev, struct tee_shm *shm)
> +{
> + struct sandbox_tee_state *state = dev_get_priv(dev);
> +
> + state->num_shms++;
> +
> + return 0;
> +}
> +
> +static int sandbox_tee_shm_unregister(struct udevice *dev, struct tee_shm *shm)
> +{
> + struct sandbox_tee_state *state = dev_get_priv(dev);
> +
> + state->num_shms--;
> +
> + return 0;
> +}
> +
> +static const struct tee_driver_ops sandbox_tee_ops = {
> + .get_version = sandbox_tee_get_version,
> + .open_session = sandbox_tee_open_session,
> + .close_session = sandbox_tee_close_session,
> + .invoke_func = sandbox_tee_invoke_func,
> + .shm_register = sandbox_tee_shm_register,
> + .shm_unregister = sandbox_tee_shm_unregister,
> +};
> +
> +static const struct udevice_id sandbox_tee_match[] = {
> + { .compatible = "sandbox,tee" },
> + {},
> +};
> +
> +U_BOOT_DRIVER(sandbox_tee) = {
> + .name = "sandbox_tee",
> + .id = UCLASS_TEE,
> + .of_match = sandbox_tee_match,
> + .ops = &sandbox_tee_ops,
> + .priv_auto_alloc_size = sizeof(struct sandbox_tee_state),
> +};
> diff --git a/include/sandboxtee.h b/include/sandboxtee.h
> new file mode 100644
> index 000000000000..59cbb621820b
> --- /dev/null
> +++ b/include/sandboxtee.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright (C) 2018 Linaro Limited
> + */
> +
> +#ifndef __SANDBOXTEE_H
> +#define __SANDBOXTEE_H
> +
> +struct sandbox_tee_state {
> + u32 session;
> + int num_shms;
> + void *ta;
struct/members need comments
> +};
> +
> +#endif /*__SANDBOXTEE_H*/
> --
> 2.17.1
>
Regards,
Simon
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