[U-Boot] [PATCH v4 14/19] tee: add sandbox driver
Jens Wiklander
jens.wiklander at linaro.org
Tue Sep 25 14:40:18 UTC 2018
Adds a sandbox tee driver which emulates a generic TEE with the OP-TEE
AVB TA.
Reviewed-by: Simon Glass <sjg at chromium.org>
Signed-off-by: Jens Wiklander <jens.wiklander at linaro.org>
---
drivers/tee/Kconfig | 18 ++-
drivers/tee/Makefile | 1 +
drivers/tee/optee/Kconfig | 2 +-
drivers/tee/sandbox.c | 308 ++++++++++++++++++++++++++++++++++++++
include/sandboxtee.h | 21 +++
5 files changed, 347 insertions(+), 3 deletions(-)
create mode 100644 drivers/tee/sandbox.c
create mode 100644 include/sandboxtee.h
diff --git a/drivers/tee/Kconfig b/drivers/tee/Kconfig
index 835c256e9239..5c0c89043fac 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 +14,20 @@ 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
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..10a1e8dffa69
--- /dev/null
+++ b/drivers/tee/sandbox.c
@@ -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 %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..44f653d9cf3b
--- /dev/null
+++ b/include/sandboxtee.h
@@ -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*/
--
2.17.1
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