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// SPDX-License-Identifier: BSD-2-Clause
/* Copyright (c) 2018, Linaro Limited */
#include <ta_avb.h>
#include <tee_internal_api.h>
#include <tee_internal_api_extensions.h>
#define DEFAULT_LOCK_STATE 0
static const uint32_t storageid = TEE_STORAGE_PRIVATE_RPMB;
static const char obj_name[] = "rb_state";
static TEE_Result get_slot_offset(size_t slot, size_t *offset)
{
if (slot >= TA_AVB_MAX_ROLLBACK_LOCATIONS)
return TEE_ERROR_BAD_PARAMETERS;
*offset = sizeof(uint32_t) /* lock_state */ + slot * sizeof(uint64_t);
return TEE_SUCCESS;
}
static TEE_Result create_state(uint32_t lock_state, TEE_ObjectHandle *h)
{
const uint32_t flags = TEE_DATA_FLAG_ACCESS_READ |
TEE_DATA_FLAG_ACCESS_WRITE |
TEE_DATA_FLAG_OVERWRITE;
return TEE_CreatePersistentObject(storageid, obj_name, sizeof(obj_name),
flags, NULL, &lock_state,
sizeof(lock_state), h);
}
static TEE_Result open_state(uint32_t default_lock_state, TEE_ObjectHandle *h)
{
uint32_t flags = TEE_DATA_FLAG_ACCESS_READ | TEE_DATA_FLAG_ACCESS_WRITE;
TEE_Result res;
res = TEE_OpenPersistentObject(storageid, obj_name,
sizeof(obj_name), flags, h);
if (!res)
return TEE_SUCCESS;
return create_state(default_lock_state, h);
}
static TEE_Result read_rb_idx(uint32_t pt, TEE_Param params[TEE_NUM_PARAMS])
{
const uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_INPUT,
TEE_PARAM_TYPE_VALUE_OUTPUT,
TEE_PARAM_TYPE_NONE,
TEE_PARAM_TYPE_NONE);
size_t slot_offset;
uint64_t idx;
uint32_t count;
TEE_Result res;
TEE_ObjectHandle h;
if (pt != exp_pt)
return TEE_ERROR_BAD_PARAMETERS;
res = get_slot_offset(params[0].value.a, &slot_offset);
if (res)
return res;
res = open_state(DEFAULT_LOCK_STATE, &h);
if (res)
return res;
res = TEE_SeekObjectData(h, slot_offset, TEE_DATA_SEEK_SET);
if (res)
goto out;
res = TEE_ReadObjectData(h, &idx, sizeof(idx), &count);
if (res)
goto out;
if (count != sizeof(idx)) {
idx = 0; /* Not yet written slots are reported as 0 */
if (count) {
/*
* Somehow the file didn't even hold a complete
* slot index entry. Write it as 0.
*/
res = TEE_SeekObjectData(h, slot_offset,
TEE_DATA_SEEK_SET);
if (res)
goto out;
res = TEE_WriteObjectData(h, &idx, sizeof(idx));
if (res)
goto out;
}
}
params[1].value.a = idx >> 32;
params[1].value.b = idx;
out:
TEE_CloseObject(h);
return res;
}
static TEE_Result write_rb_idx(uint32_t pt, TEE_Param params[TEE_NUM_PARAMS])
{
const uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_INPUT,
TEE_PARAM_TYPE_VALUE_INPUT,
TEE_PARAM_TYPE_NONE,
TEE_PARAM_TYPE_NONE);
size_t slot_offset;
uint64_t widx;
uint64_t idx;
uint32_t count;
TEE_Result res;
TEE_ObjectHandle h;
if (pt != exp_pt)
return TEE_ERROR_BAD_PARAMETERS;
res = get_slot_offset(params[0].value.a, &slot_offset);
if (res)
return res;
widx = ((uint64_t)params[1].value.a << 32) | params[1].value.b;
res = open_state(DEFAULT_LOCK_STATE, &h);
if (res)
return res;
res = TEE_SeekObjectData(h, slot_offset, TEE_DATA_SEEK_SET);
if (res)
goto out;
res = TEE_ReadObjectData(h, &idx, sizeof(idx), &count);
if (res)
goto out;
if (count != sizeof(idx))
idx = 0; /* Not yet written slots are reported as 0 */
if (widx < idx) {
res = TEE_ERROR_SECURITY;
goto out;
}
res = TEE_SeekObjectData(h, slot_offset, TEE_DATA_SEEK_SET);
if (res)
goto out;
res = TEE_WriteObjectData(h, &widx, sizeof(widx));
out:
TEE_CloseObject(h);
return res;
}
static TEE_Result read_lock_state(uint32_t pt, TEE_Param params[TEE_NUM_PARAMS])
{
const uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_OUTPUT,
TEE_PARAM_TYPE_NONE,
TEE_PARAM_TYPE_NONE,
TEE_PARAM_TYPE_NONE);
uint32_t lock_state;
uint32_t count;
TEE_Result res;
TEE_ObjectHandle h;
if (pt != exp_pt)
return TEE_ERROR_BAD_PARAMETERS;
res = open_state(DEFAULT_LOCK_STATE, &h);
if (res)
return res;
res = TEE_ReadObjectData(h, &lock_state, sizeof(lock_state), &count);
if (res)
goto out;
if (count != sizeof(lock_state)) {
/*
* Client need write the lock state to recover, this can
* normally not happen.
*/
res = TEE_ERROR_CORRUPT_OBJECT;
goto out;
}
params[0].value.a = lock_state;
out:
TEE_CloseObject(h);
return res;
}
static TEE_Result write_lock_state(uint32_t pt,
TEE_Param params[TEE_NUM_PARAMS])
{
const uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_INPUT,
TEE_PARAM_TYPE_NONE,
TEE_PARAM_TYPE_NONE,
TEE_PARAM_TYPE_NONE);
uint32_t wlock_state;
uint32_t lock_state;
uint32_t count;
TEE_Result res;
TEE_ObjectHandle h;
if (pt != exp_pt)
return TEE_ERROR_BAD_PARAMETERS;
wlock_state = params[0].value.a;
res = open_state(wlock_state, &h);
if (res)
return res;
res = TEE_ReadObjectData(h, &lock_state, sizeof(lock_state), &count);
if (res)
goto out;
if (count == sizeof(lock_state) && lock_state == wlock_state)
goto out;
res = create_state(wlock_state, &h);
out:
TEE_CloseObject(h);
return res;
}
TEE_Result TA_CreateEntryPoint(void)
{
return TEE_SUCCESS;
}
void TA_DestroyEntryPoint(void)
{
}
TEE_Result TA_OpenSessionEntryPoint(uint32_t pt __unused,
TEE_Param params[4] __unused,
void **session __unused)
{
return TEE_SUCCESS;
}
void TA_CloseSessionEntryPoint(void *sess __unused)
{
}
TEE_Result TA_InvokeCommandEntryPoint(void *sess __unused, uint32_t cmd,
uint32_t pt,
TEE_Param params[TEE_NUM_PARAMS])
{
switch (cmd) {
case TA_AVB_CMD_READ_ROLLBACK_INDEX:
return read_rb_idx(pt, params);
case TA_AVB_CMD_WRITE_ROLLBACK_INDEX:
return write_rb_idx(pt, params);
case TA_AVB_CMD_READ_LOCK_STATE:
return read_lock_state(pt, params);
case TA_AVB_CMD_WRITE_LOCK_STATE:
return write_lock_state(pt, params);
default:
EMSG("Command ID 0x%x is not supported", cmd);
return TEE_ERROR_NOT_SUPPORTED;
}
}
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