In OP-TEE we can run EDK2's StandAloneMM on a secure partition. StandAloneMM is responsible for the UEFI variable support. In combination with OP-TEE and it's U-Boot supplicant, variables are authenticated/validated in secure world and stored on an RPMB partition.
So let's add a new config option in U-Boot implementing the necessary calls to OP-TEE for the variable management.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org Signed-off-by: Pipat Methavanitpong pipat1010@gmail.com Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org --- lib/efi_loader/Kconfig | 9 + lib/efi_loader/Makefile | 4 + lib/efi_loader/efi_variable_tee.c | 662 ++++++++++++++++++++++++++++++ 3 files changed, 675 insertions(+) create mode 100644 lib/efi_loader/efi_variable_tee.c
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig index 1cfa24ffcf72..45862a1e9caf 100644 --- a/lib/efi_loader/Kconfig +++ b/lib/efi_loader/Kconfig @@ -164,4 +164,13 @@ config EFI_SECURE_BOOT it is signed with a trusted key. To do that, you need to install, at least, PK, KEK and db.
+config EFI_MM_COMM_TEE + bool "UEFI variables storage service via OP-TEE" + depends on OPTEE + default n + help + If OP-TEE is present and running StandAloneMM dispatch all UEFI variable + related operations to that. The application will verify, authenticate and + store the variables on an RPMB + endif diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile index 84d61df55b93..57c7e66ea0e2 100644 --- a/lib/efi_loader/Makefile +++ b/lib/efi_loader/Makefile @@ -35,7 +35,11 @@ obj-y += efi_root_node.o obj-y += efi_runtime.o obj-y += efi_setup.o obj-$(CONFIG_EFI_UNICODE_COLLATION_PROTOCOL2) += efi_unicode_collation.o +ifeq ($(CONFIG_EFI_MM_COMM_TEE),y) +obj-y += efi_variable_tee.o +else obj-y += efi_variable.o +endif obj-y += efi_watchdog.o obj-$(CONFIG_LCD) += efi_gop.o obj-$(CONFIG_DM_VIDEO) += efi_gop.o diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c new file mode 100644 index 000000000000..cacc76e23db1 --- /dev/null +++ b/lib/efi_loader/efi_variable_tee.c @@ -0,0 +1,662 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * EFI variable service via OP-TEE + * + * Copyright (C) 2019 Linaro Ltd. sughosh.ganu@linaro.org + * Copyright (C) 2019 Linaro Ltd. ilias.apalodimas@linaro.org + */ + +#include <common.h> +#include <efi.h> +#include <efi_api.h> +#include <efi_loader.h> +#include <tee.h> +#include <malloc.h> +#include <mm_communication.h> + +static efi_uintn_t max_buffer_size; /* comm + var + func + data */ +static efi_uintn_t max_payload_size; /* func + data */ + +struct mm_connection { + struct udevice *tee; + u32 session; +}; + +/** + * get_connection() - Retrieve OP-TEE session for a specific UUID. + * + * @conn: session buffer to fill + * Return: status code + */ +static int get_connection(struct mm_connection *conn) +{ + static const struct tee_optee_ta_uuid uuid = PTA_STMM_UUID; + struct udevice *tee = NULL; + struct tee_open_session_arg arg; + int rc; + + tee = tee_find_device(tee, NULL, NULL, NULL); + if (!tee) + return -ENODEV; + + memset(&arg, 0, sizeof(arg)); + tee_optee_ta_uuid_to_octets(arg.uuid, &uuid); + rc = tee_open_session(tee, &arg, 0, NULL); + if (!rc) { + conn->tee = tee; + conn->session = arg.session; + } + + return rc; +} + +/** + * optee_mm_communicate() - Pass a buffer to StandaloneMM running in OP-TEE + * + * @comm_buf: locally allocted communcation buffer + * @dsize: buffer size + * Return: status code + */ +static efi_status_t optee_mm_communicate(void *comm_buf, ulong dsize) +{ + ulong buf_size; + efi_status_t ret; + struct efi_mm_communicate_header *mm_hdr; + struct mm_connection conn = { NULL, 0 }; + struct tee_invoke_arg arg; + struct tee_param param[2]; + struct tee_shm *shm = NULL; + int rc; + + if (!comm_buf) + return EFI_INVALID_PARAMETER; + + mm_hdr = (struct efi_mm_communicate_header *)comm_buf; + buf_size = mm_hdr->message_len + sizeof(efi_guid_t) + sizeof(size_t); + + if (dsize != buf_size) + return EFI_INVALID_PARAMETER; + + rc = get_connection(&conn); + if (rc) { + log_err("Unable to open OP-TEE session (err=%d)\n", rc); + return EFI_UNSUPPORTED; + } + + if (tee_shm_register(conn.tee, comm_buf, buf_size, 0, &shm)) { + log_err("Unable to register shared memory\n"); + return EFI_UNSUPPORTED; + } + + memset(&arg, 0, sizeof(arg)); + arg.func = PTA_STMM_CMDID_COMMUNICATE; + arg.session = conn.session; + + memset(param, 0, sizeof(param)); + param[0].attr = TEE_PARAM_ATTR_TYPE_MEMREF_INOUT; + param[0].u.memref.size = buf_size; + param[0].u.memref.shm = shm; + param[1].attr = TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT; + + rc = tee_invoke_func(conn.tee, &arg, 2, param); + if (rc) + return EFI_INVALID_PARAMETER; + tee_shm_free(shm); + tee_close_session(conn.tee, conn.session); + + switch (param[1].u.value.a) { + case ARM_SMC_MM_RET_SUCCESS: + ret = EFI_SUCCESS; + break; + + case ARM_SMC_MM_RET_INVALID_PARAMS: + ret = EFI_INVALID_PARAMETER; + break; + + case ARM_SMC_MM_RET_DENIED: + ret = EFI_ACCESS_DENIED; + break; + + case ARM_SMC_MM_RET_NO_MEMORY: + ret = EFI_OUT_OF_RESOURCES; + break; + + default: + ret = EFI_ACCESS_DENIED; + } + + return ret; +} + +/** + * mm_communicate() - Adjust the cmonnucation buffer to StandAlonneMM and send + * it to OP-TEE + * + * @comm_buf: locally allocted communcation buffer + * @dsize: buffer size + * Return: status code + */ +static efi_status_t mm_communicate(u8 *comm_buf, efi_uintn_t dsize) +{ + efi_status_t ret; + struct efi_mm_communicate_header *mm_hdr; + struct smm_variable_communicate_header *var_hdr; + + dsize += MM_COMMUNICATE_HEADER_SIZE + MM_VARIABLE_COMMUNICATE_SIZE; + mm_hdr = (struct efi_mm_communicate_header *)comm_buf; + var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data; + + ret = optee_mm_communicate(comm_buf, dsize); + if (ret != EFI_SUCCESS) { + log_err("%s failed!\n", __func__); + return ret; + } + + return var_hdr->ret_status; +} + +/** + * setup_mm_hdr() - Allocate a buffer for StandAloneMM and initialize the + * header data. + * + * @dptr: pointer address of the corresponding StandAloneMM + * function + * @payload_size: buffer size + * @func: standAloneMM function number + * @ret: EFI return code + * Return: buffer or NULL + */ +static u8 *setup_mm_hdr(void **dptr, efi_uintn_t payload_size, + efi_uintn_t func, efi_status_t *ret) +{ + const efi_guid_t mm_var_guid = EFI_MM_VARIABLE_GUID; + struct efi_mm_communicate_header *mm_hdr; + struct smm_variable_communicate_header *var_hdr; + u8 *comm_buf; + + /* In the init function we initialize max_buffer_size with + * get_max_payload(). So skip the test if max_buffer_size is initialized + * StandAloneMM will perform similar checks and drop the buffer if it's + * too long + */ + if (max_buffer_size && max_buffer_size < + (MM_COMMUNICATE_HEADER_SIZE + + MM_VARIABLE_COMMUNICATE_SIZE + + payload_size)) { + *ret = EFI_INVALID_PARAMETER; + return NULL; + } + + comm_buf = calloc(1, MM_COMMUNICATE_HEADER_SIZE + + MM_VARIABLE_COMMUNICATE_SIZE + + payload_size); + if (!comm_buf) { + *ret = EFI_OUT_OF_RESOURCES; + return NULL; + } + + mm_hdr = (struct efi_mm_communicate_header *)comm_buf; + guidcpy(&mm_hdr->header_guid, &mm_var_guid); + mm_hdr->message_len = MM_VARIABLE_COMMUNICATE_SIZE + payload_size; + + var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data; + var_hdr->function = func; + if (dptr) + *dptr = var_hdr->data; + *ret = EFI_SUCCESS; + + return comm_buf; +} + +/** + * get_max_payload() - Get variable payload size from StandAloneMM. + * + * @size: size of the variable in storage + * Return: status code + */ +efi_status_t EFIAPI get_max_payload(efi_uintn_t *size) +{ + struct smm_variable_payload_size *var_payload = NULL; + efi_uintn_t payload_size; + u8 *comm_buf = NULL; + efi_status_t ret; + + if (!size) { + ret = EFI_INVALID_PARAMETER; + goto out; + } + + payload_size = sizeof(*var_payload); + comm_buf = setup_mm_hdr((void **)&var_payload, payload_size, + SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE, &ret); + if (!comm_buf) + goto out; + + ret = mm_communicate(comm_buf, payload_size); + if (ret != EFI_SUCCESS) + goto out; + + *size = var_payload->size; + +out: + free(comm_buf); + return ret; +} + +/** + * efi_get_variable() - retrieve value of a UEFI variable + * + * This function implements the GetVariable runtime service. + * + * See the Unified Extensible Firmware Interface (UEFI) specification for + * details. + * + * @name: name of the variable + * @guid: vendor GUID + * @attr: attributes of the variable + * @data_size: size of the buffer to which the variable value is copied + * @data: buffer to which the variable value is copied + * Return: status code + */ +efi_status_t EFIAPI efi_get_variable(u16 *name, const efi_guid_t *guid, + u32 *attr, efi_uintn_t *data_size, + void *data) +{ + struct smm_variable_access *var_acc; + efi_uintn_t payload_size; + efi_uintn_t name_size; + efi_uintn_t tmp_dsize; + u8 *comm_buf = NULL; + efi_status_t ret; + + EFI_ENTRY(""%ls" %pUl %p %p %p", name, guid, attr, data_size, data); + + if (!name || !guid || !data_size) { + ret = EFI_INVALID_PARAMETER; + goto out; + } + + /* Check payload size */ + name_size = u16_strsize(name); + if (name_size > max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) { + ret = EFI_INVALID_PARAMETER; + goto out; + } + + /* Trim output buffer size */ + tmp_dsize = *data_size; + if (name_size + tmp_dsize > + max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) { + tmp_dsize = max_payload_size - + MM_VARIABLE_ACCESS_HEADER_SIZE - + name_size; + } + + /* Get communication buffer and initialize header */ + payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + tmp_dsize; + comm_buf = setup_mm_hdr((void **)&var_acc, payload_size, + SMM_VARIABLE_FUNCTION_GET_VARIABLE, &ret); + if (!comm_buf) + goto out; + + /* Fill in contents */ + guidcpy(&var_acc->guid, guid); + var_acc->data_size = tmp_dsize; + var_acc->name_size = name_size; + var_acc->attr = attr ? *attr : 0; + memcpy(var_acc->name, name, name_size); + + /* Communicate */ + ret = mm_communicate(comm_buf, payload_size); + if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) { + /* Update with reported data size for trimmed case */ + *data_size = var_acc->data_size; + } + if (ret != EFI_SUCCESS) + goto out; + + if (attr) + *attr = var_acc->attr; + if (data) + memcpy(data, (u8 *)var_acc->name + var_acc->name_size, + var_acc->data_size); + else + ret = EFI_INVALID_PARAMETER; + +out: + free(comm_buf); + return EFI_EXIT(ret); +} + +/** + * efi_get_next_variable_name() - enumerate the current variable names + * + * @variable_name_size: size of variable_name buffer in bytes + * @variable_name: name of uefi variable's name in u16 + * @guid: vendor's guid + * + * This function implements the GetNextVariableName service. + * + * See the Unified Extensible Firmware Interface (UEFI) specification for + * details. + * + * Return: status code + */ +efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size, + u16 *variable_name, + efi_guid_t *guid) +{ + struct smm_variable_getnext *var_getnext; + efi_uintn_t payload_size; + efi_uintn_t out_name_size; + efi_uintn_t in_name_size; + efi_uintn_t tmp_dsize; + efi_uintn_t name_size; + u8 *comm_buf = NULL; + efi_status_t ret; + + EFI_ENTRY("%p "%ls" %pUl", variable_name_size, variable_name, guid); + + if (!variable_name_size || !variable_name || !guid) { + ret = EFI_INVALID_PARAMETER; + goto out; + } + + out_name_size = *variable_name_size; + in_name_size = u16_strsize(variable_name); + + if (out_name_size < in_name_size) { + ret = EFI_INVALID_PARAMETER; + goto out; + } + + name_size = u16_strsize(variable_name); + if (name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) { + ret = EFI_INVALID_PARAMETER; + goto out; + } + + /* Trim output buffer size */ + tmp_dsize = *variable_name_size; + if (name_size + tmp_dsize > + max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) { + tmp_dsize = max_payload_size - + MM_VARIABLE_GET_NEXT_HEADER_SIZE - + name_size; + } + + payload_size = MM_VARIABLE_GET_NEXT_HEADER_SIZE + out_name_size; + comm_buf = setup_mm_hdr((void **)&var_getnext, payload_size, + SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME, + &ret); + if (!comm_buf) + goto out; + + /* Fill in contents */ + guidcpy(&var_getnext->guid, guid); + var_getnext->name_size = out_name_size; + memcpy(var_getnext->name, variable_name, in_name_size); + memset((u8 *)var_getnext->name + in_name_size, 0x0, + out_name_size - in_name_size); + + /* Communicate */ + ret = mm_communicate(comm_buf, payload_size); + if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) { + /* Update with reported data size for trimmed case */ + *variable_name_size = var_getnext->name_size; + } + if (ret != EFI_SUCCESS) + goto out; + + guidcpy(guid, &var_getnext->guid); + memcpy(variable_name, (u8 *)var_getnext->name, + var_getnext->name_size); + +out: + free(comm_buf); + return EFI_EXIT(ret); +} + +/** + * efi_set_variable() - set value of a UEFI variable + * + * This function implements the SetVariable runtime service. + * + * See the Unified Extensible Firmware Interface (UEFI) specification for + * details. + * + * @name: name of the variable + * @guid: vendor GUID + * @attr: attributes of the variable + * @data_size: size of the buffer with the variable value + * @data: buffer with the variable value + * Return: status code + */ +efi_status_t EFIAPI efi_set_variable(u16 *name, const efi_guid_t *guid, + u32 attr, efi_uintn_t data_size, + const void *data) +{ + struct smm_variable_access *var_acc; + efi_uintn_t payload_size; + efi_uintn_t name_size; + u8 *comm_buf = NULL; + efi_status_t ret; + + EFI_ENTRY(""%ls" %pUl %x %zu %p", name, guid, attr, data_size, data); + + if (!name || name[0] == 0 || !guid) { + ret = EFI_INVALID_PARAMETER; + goto out; + } + if (data_size > 0 && !data) { + ret = EFI_INVALID_PARAMETER; + goto out; + } + + /* Check payload size */ + name_size = u16_strsize(name); + payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + data_size; + if (payload_size > max_payload_size) { + ret = EFI_INVALID_PARAMETER; + goto out; + } + + /* Get communication buffer and initialize header */ + comm_buf = setup_mm_hdr((void **)&var_acc, payload_size, + SMM_VARIABLE_FUNCTION_SET_VARIABLE, &ret); + if (!comm_buf) + goto out; + + /* Fill in contents */ + guidcpy(&var_acc->guid, guid); + var_acc->data_size = data_size; + var_acc->name_size = name_size; + var_acc->attr = attr; + memcpy(var_acc->name, name, name_size); + memcpy((u8 *)var_acc->name + name_size, data, data_size); + + /* Communicate */ + ret = mm_communicate(comm_buf, payload_size); + +out: + free(comm_buf); + return EFI_EXIT(ret); +} + +/** + * efi_query_variable_info() - get information about EFI variables + * + * This function implements the QueryVariableInfo() runtime service. + * + * See the Unified Extensible Firmware Interface (UEFI) specification for + * details. + * + * @attributes: bitmask to select variables to be + * queried + * @maximum_variable_storage_size: maximum size of storage area for the + * selected variable types + * @remaining_variable_storage_size: remaining size of storage are for the + * selected variable types + * @maximum_variable_size: maximum size of a variable of the + * selected type + * Returns: status code + */ +efi_status_t EFIAPI __efi_runtime +efi_query_variable_info(u32 attributes, u64 *max_variable_storage_size, + u64 *remain_variable_storage_size, + u64 *max_variable_size) +{ + struct smm_variable_query_info *mm_query_info; + efi_uintn_t payload_size; + efi_status_t ret; + u8 *comm_buf; + + EFI_ENTRY("%x %p %p %p", attributes, max_variable_storage_size, + remain_variable_storage_size, max_variable_size); + + payload_size = sizeof(*mm_query_info); + comm_buf = setup_mm_hdr((void **)&mm_query_info, payload_size, + SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO, + &ret); + if (!comm_buf) + goto out; + + mm_query_info->attr = attributes; + ret = mm_communicate(comm_buf, payload_size); + if (ret != EFI_SUCCESS) + goto out; + *max_variable_storage_size = mm_query_info->max_variable_storage; + *remain_variable_storage_size = + mm_query_info->remaining_variable_storage; + *max_variable_size = mm_query_info->max_variable_size; + +out: + free(comm_buf); + return EFI_EXIT(ret); +} + +/** + * efi_get_variable_runtime() - runtime implementation of GetVariable() + * + * @variable_name: name of the variable + * @guid: vendor GUID + * @attributes: attributes of the variable + * @data_size: size of the buffer to which the variable value is copied + * @data: buffer to which the variable value is copied + * Return: status code + */ +static efi_status_t __efi_runtime EFIAPI +efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *guid, + u32 *attributes, efi_uintn_t *data_size, void *data) +{ + return EFI_UNSUPPORTED; +} + +/** + * efi_get_next_variable_name_runtime() - runtime implementation of + * GetNextVariable() + * + * @variable_name_size: size of variable_name buffer in byte + * @variable_name: name of uefi variable's name in u16 + * @guid: vendor's guid + * Return: status code + */ +static efi_status_t __efi_runtime EFIAPI +efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size, + u16 *variable_name, efi_guid_t *guid) +{ + return EFI_UNSUPPORTED; +} + +/** + * efi_query_variable_info() - get information about EFI variables + * + * This function implements the QueryVariableInfo() runtime service. + * + * See the Unified Extensible Firmware Interface (UEFI) specification for + * details. + * + * @attributes: bitmask to select variables to be + * queried + * @maximum_variable_storage_size: maximum size of storage area for the + * selected variable types + * @remaining_variable_storage_size: remaining size of storage are for the + * selected variable types + * @maximum_variable_size: maximum size of a variable of the + * selected type + * Return: status code + */ +efi_status_t EFIAPI __efi_runtime +efi_query_variable_info_runtime(u32 attributes, u64 *max_variable_storage_size, + u64 *remain_variable_storage_size, + u64 *max_variable_size) +{ + return EFI_UNSUPPORTED; +} + +/** + * efi_set_variable_runtime() - runtime implementation of SetVariable() + * + * @variable_name: name of the variable + * @guid: vendor GUID + * @attributes: attributes of the variable + * @data_size: size of the buffer with the variable value + * @data: buffer with the variable value + * Return: status code + */ +static efi_status_t __efi_runtime EFIAPI +efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *guid, + u32 attributes, efi_uintn_t data_size, + const void *data) +{ + return EFI_UNSUPPORTED; +} + +/** + * efi_variables_boot_exit_notify() - notify ExitBootServices() is called + */ +void efi_variables_boot_exit_notify(void) +{ + u8 *comm_buf; + efi_status_t ret; + + comm_buf = setup_mm_hdr(NULL, 0, + SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE, &ret); + if (comm_buf) + ret = mm_communicate(comm_buf, 0); + else + ret = EFI_NOT_FOUND; + + if (ret != EFI_SUCCESS) + log_err("Unable to notify StMM for ExitBootServices\n"); + free(comm_buf); + + /* Update runtime service table */ + efi_runtime_services.query_variable_info = + efi_query_variable_info_runtime; + efi_runtime_services.get_variable = efi_get_variable_runtime; + efi_runtime_services.get_next_variable_name = + efi_get_next_variable_name_runtime; + efi_runtime_services.set_variable = efi_set_variable_runtime; + efi_update_table_header_crc32(&efi_runtime_services.hdr); +} + +/** + * efi_init_variables() - initialize variable services + * + * Return: status code + */ +efi_status_t efi_init_variables(void) +{ + efi_status_t ret; + + ret = get_max_payload(&max_payload_size); + if (ret != EFI_SUCCESS) + return ret; + + max_buffer_size = MM_COMMUNICATE_HEADER_SIZE + + MM_VARIABLE_COMMUNICATE_SIZE + + max_payload_size; + + return EFI_SUCCESS; +}