tee: add sandbox driver

Adds a sandbox tee driver which emulates a generic TEE with the OP-TEE
AVB TA.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
[trini: Fix printf warnings in ta_avb_invoke_func, slots is uint]
Signed-off-by: Tom Rini <trini@konsulko.com>
This commit is contained in:
Jens Wiklander 2018-09-25 16:40:18 +02:00 committed by Tom Rini
parent fe39e8e0ee
commit eadf26f183
5 changed files with 347 additions and 3 deletions

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@ -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 +14,20 @@ 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. The emulation provides all callbacks of a regular TEE and
supports session and shared memory management. The AVB TA is
emulated with rollback indexes and device lock-state, the state
of the TA is only kept in RAM and will be reset on each boot.
The emulation only supports one open session at a time.
Interaction from the U-Boot command line in possible via the
"avb" commands.
source "drivers/tee/optee/Kconfig"
endmenu

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@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0+
obj-y += tee-uclass.o
obj-$(CONFIG_SANDBOX) += sandbox.o
obj-$(CONFIG_OPTEE) += optee/

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@ -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"

308
drivers/tee/sandbox.c Normal file
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@ -0,0 +1,308 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2018 Linaro Limited
*/
#include <common.h>
#include <dm.h>
#include <sandboxtee.h>
#include <tee.h>
#include <tee/optee_ta_avb.h>
/*
* The sandbox tee driver tries to emulate a generic Trusted Exectution
* Environment (TEE) with the Trusted Application (TA) OPTEE_TA_AVB
* available.
*/
/**
* struct ta_entry - TA entries
* @uuid: UUID of an emulated TA
* @open_session Called when a session is openened to the TA
* @invoke_func Called when a function in the TA is to be invoked
*
* This struct is used to register TAs in this sandbox emulation of a TEE.
*/
struct ta_entry {
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 %u\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 %u\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),
};

21
include/sandboxtee.h Normal file
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@ -0,0 +1,21 @@
/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2018 Linaro Limited
*/
#ifndef __SANDBOXTEE_H
#define __SANDBOXTEE_H
/**
* struct sandbox_tee_state - internal state of the sandbox TEE
* @session: current open session
* @num_shms: number of registered shared memory objects
* @ta: Trusted Application of current session
*/
struct sandbox_tee_state {
u32 session;
int num_shms;
void *ta;
};
#endif /*__SANDBOXTEE_H*/