OPTEE CA接口及数据结构

Linux userspace 中使用的API都按照GP标准进行定义，这些接口基本能够满足用户在userspace层面的需求，在系统中这部分会被编译成libteec库的形式存在。

一、参数宏定义：/*
* Defines the number of available memory references in an open session or
* invoke command operation payload.
*/
#define TEEC_CONFIG_PAYLOAD_REF_COUNT 4

/**
* Defines the maximum size of a single shared memory block, in bytes, of both
* API allocated and API registered memory. There is no good value to put here
* (limits depend on specific config used), so this define does not provide any
* restriction in this implementation.
*/
#define TEEC_CONFIG_SHAREDMEM_MAX_SIZE ULONG_MAX

/**
* Flag constants indicating the type of parameters encoded inside the
* operation payload (TEEC_Operation), Type is uint32_t.
*
* TEEC_NONE The Parameter is not used
*
* TEEC_VALUE_INPUT The Parameter is a TEEC_Value tagged as input.
*
* TEEC_VALUE_OUTPUT The Parameter is a TEEC_Value tagged as output.
*
* TEEC_VALUE_INOUT The Parameter is a TEEC_Value tagged as both as
* input and output, i.e., for which both the
* behaviors of TEEC_VALUE_INPUT and
* TEEC_VALUE_OUTPUT apply.
*
* TEEC_MEMREF_TEMP_INPUT The Parameter is a TEEC_TempMemoryReference
* describing a region of memory which needs to be
* temporarily registered for the duration of the
* Operation and is tagged as input.
*
* TEEC_MEMREF_TEMP_OUTPUT Same as TEEC_MEMREF_TEMP_INPUT, but the Memory
* Reference is tagged as output. The
* Implementation may update the size field to
* reflect the required output size in some use
* cases.
*
* TEEC_MEMREF_TEMP_INOUT A Temporary Memory Reference tagged as both
* input and output, i.e., for which both the
* behaviors of TEEC_MEMREF_TEMP_INPUT and
* TEEC_MEMREF_TEMP_OUTPUT apply.
*
* TEEC_MEMREF_WHOLE The Parameter is a Registered Memory Reference
* that refers to the entirety of its parent Shared
* Memory block. The parameter structure is a
* TEEC_MemoryReference. In this structure, the
* Implementation MUST read only the parent field
* and MAY update the size field when the operation
* completes.
*
* TEEC_MEMREF_PARTIAL_INPUT A Registered Memory Reference structure that
* refers to a partial region of its parent Shared
* Memory block and is tagged as input.
*
* TEEC_MEMREF_PARTIAL_OUTPUT Registered Memory Reference structure that
* refers to a partial region of its parent Shared
* Memory block and is tagged as output.
*
* TEEC_MEMREF_PARTIAL_INOUT The Registered Memory Reference structure that
* refers to a partial region of its parent Shared
* Memory block and is tagged as both input and
* output, i.e., for which both the behaviors of
* TEEC_MEMREF_PARTIAL_INPUT and
* TEEC_MEMREF_PARTIAL_OUTPUT apply.
*/
#define TEEC_NONE 0x00000000
#define TEEC_VALUE_INPUT 0x00000001
#define TEEC_VALUE_OUTPUT 0x00000002
#define TEEC_VALUE_INOUT 0x00000003
#define TEEC_MEMREF_TEMP_INPUT 0x00000005
#define TEEC_MEMREF_TEMP_OUTPUT 0x00000006
#define TEEC_MEMREF_TEMP_INOUT 0x00000007
#define TEEC_MEMREF_WHOLE 0x0000000C
#define TEEC_MEMREF_PARTIAL_INPUT 0x0000000D
#define TEEC_MEMREF_PARTIAL_OUTPUT 0x0000000E
#define TEEC_MEMREF_PARTIAL_INOUT 0x0000000F

/**
* Flag constants indicating the data transfer direction of memory in
* TEEC_Parameter. TEEC_MEM_INPUT signifies data transfer direction from the
* client application to the TEE. TEEC_MEM_OUTPUT signifies data transfer
* direction from the TEE to the client application. Type is uint32_t.
*
* TEEC_MEM_INPUT The Shared Memory can carry data from the client
* application to the Trusted Application.
* TEEC_MEM_OUTPUT The Shared Memory can carry data from the Trusted
* Application to the client application.
*/
#define TEEC_MEM_INPUT 0x00000001
#define TEEC_MEM_OUTPUT 0x00000002

/**
* Return values. Type is TEEC_Result
*
* TEEC_SUCCESS The operation was successful.
* TEEC_ERROR_GENERIC Non-specific cause.
* TEEC_ERROR_ACCESS_DENIED Access privileges are not sufficient.
* TEEC_ERROR_CANCEL The operation was canceled.
* TEEC_ERROR_ACCESS_CONFLICT Concurrent accesses caused conflict.
* TEEC_ERROR_EXCESS_DATA Too much data for the requested operation was
* passed.
* TEEC_ERROR_BAD_FORMAT Input data was of invalid format.
* TEEC_ERROR_BAD_PARAMETERS Input parameters were invalid.
* TEEC_ERROR_BAD_STATE Operation is not valid in the current state.
* TEEC_ERROR_ITEM_NOT_FOUND The requested data item is not found.
* TEEC_ERROR_NOT_IMPLEMENTED The requested operation should exist but is not
* yet implemented.
* TEEC_ERROR_NOT_SUPPORTED The requested operation is valid but is not
* supported in this implementation.
* TEEC_ERROR_NO_DATA Expected data was missing.
* TEEC_ERROR_OUT_OF_MEMORY System ran out of resources.
* TEEC_ERROR_BUSY The system is busy working on something else.
* TEEC_ERROR_COMMUNICATION Communication with a remote party failed.
* TEEC_ERROR_SECURITY A security fault was detected.
* TEEC_ERROR_SHORT_BUFFER The supplied buffer is too short for the
* generated output.
* TEEC_ERROR_TARGET_DEAD Trusted Application has panicked
* during the operation.
*/

/**
* Standard defined error codes.
*/
#define TEEC_SUCCESS 0x00000000
#define TEEC_ERROR_GENERIC 0xFFFF0000
#define TEEC_ERROR_ACCESS_DENIED 0xFFFF0001
#define TEEC_ERROR_CANCEL 0xFFFF0002
#define TEEC_ERROR_ACCESS_CONFLICT 0xFFFF0003
#define TEEC_ERROR_EXCESS_DATA 0xFFFF0004
#define TEEC_ERROR_BAD_FORMAT 0xFFFF0005
#define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006
#define TEEC_ERROR_BAD_STATE 0xFFFF0007
#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008
#define TEEC_ERROR_NOT_IMPLEMENTED 0xFFFF0009
#define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A
#define TEEC_ERROR_NO_DATA 0xFFFF000B
#define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C
#define TEEC_ERROR_BUSY 0xFFFF000D
#define TEEC_ERROR_COMMUNICATION 0xFFFF000E
#define TEEC_ERROR_SECURITY 0xFFFF000F
#define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010
#define TEEC_ERROR_EXTERNAL_CANCEL 0xFFFF0011
#define TEEC_ERROR_TARGET_DEAD 0xFFFF3024

/**
* Function error origins, of type TEEC_ErrorOrigin. These indicate where in
* the software stack a particular return value originates from.
*
* TEEC_ORIGIN_API The error originated within the TEE Client API
* implementation.
* TEEC_ORIGIN_COMMS The error originated within the underlying
* communications stack linking the rich OS with
* the TEE.
* TEEC_ORIGIN_TEE The error originated within the common TEE code.
* TEEC_ORIGIN_TRUSTED_APP The error originated within the Trusted Application
* code.
*/
#define TEEC_ORIGIN_API 0x00000001
#define TEEC_ORIGIN_COMMS 0x00000002
#define TEEC_ORIGIN_TEE 0x00000003
#define TEEC_ORIGIN_TRUSTED_APP 0x00000004

/**
* Session login methods, for use in TEEC_OpenSession() as parameter
* connectionMethod. Type is uint32_t.
*
* TEEC_LOGIN_PUBLIC No login data is provided.
* TEEC_LOGIN_USER Login data about the user running the Client
* Application process is provided.
* TEEC_LOGIN_GROUP Login data about the group running the Client
* Application process is provided.
* TEEC_LOGIN_APPLICATION Login data about the running Client Application
* itself is provided.
* TEEC_LOGIN_USER_APPLICATION Login data about the user and the running
* Client Application itself is provided.
* TEEC_LOGIN_GROUP_APPLICATION Login data about the group and the running
* Client Application itself is provided.
*/
#define TEEC_LOGIN_PUBLIC 0x00000000
#define TEEC_LOGIN_USER 0x00000001
#define TEEC_LOGIN_GROUP 0x00000002
#define TEEC_LOGIN_APPLICATION 0x00000004
#define TEEC_LOGIN_USER_APPLICATION 0x00000005
#define TEEC_LOGIN_GROUP_APPLICATION 0x00000006

//使用位操作来实现参数传递
/**
* Encode the paramTypes according to the supplied types.
*
* @param p0 The first param type.
* @param p1 The second param type.
* @param p2 The third param type.
* @param p3 The fourth param type.
*/
#define TEEC_PARAM_TYPES(p0, p1, p2, p3) \
((p0) | ((p1) << 4) | ((p2) << 8) | ((p3) << 12))

/**
* Get the i_th param type from the paramType.
*
* @param p The paramType.
* @param i The i-th parameter to get the type for.
*/
#define TEEC_PARAM_TYPE_GET(p, i) (((p) >> (i * 4)) & 0xF)二、基本数据结构：

//使用的数据结构

typedef uint32_t TEEC_Result;

/**
* struct TEEC_Context - Represents a connection between a client application
* and a TEE.
*/
typedef struct {
/* Implementation defined */
int fd;
bool reg_mem;
} TEEC_Context;

/**
* This type contains a Universally Unique Resource Identifier (UUID) type as
* defined in RFC4122. These UUID values are used to identify Trusted
* Applications.
*/
typedef struct {
uint32_t timeLow;
uint16_t timeMid;
uint16_t timeHiAndVersion;
uint8_t clockSeqAndNode[8];
} TEEC_UUID;

/**
* struct TEEC_SharedMemory - Memory to transfer data between a client
* application and trusted code.
*
* @param buffer      The memory buffer which is to be, or has been, shared
*                    with the TEE.
* @param size        The size, in bytes, of the memory buffer.
* @param flags       Bit-vector which holds properties of buffer.
*                    The bit-vector can contain either or both of the
*                    TEEC_MEM_INPUT and TEEC_MEM_OUTPUT flags.
*
* A shared memory block is a region of memory allocated in the context of the
* client application memory space that can be used to transfer data between
* that client application and a trusted application. The user of this struct
* is responsible to populate the buffer pointer.
*/
typedef struct {
void *buffer;
size_t size;
uint32_t flags;
/*
* Implementation-Defined
*/
int id;
size_t alloced_size;
void *shadow_buffer;
int registered_fd;
bool buffer_allocated;
} TEEC_SharedMemory;

/**
* struct TEEC_TempMemoryReference - Temporary memory to transfer data between
* a client application and trusted code, only used for the duration of the
* operation.
*
* @param buffer  The memory buffer which is to be, or has been shared with
*                the TEE.
* @param size    The size, in bytes, of the memory buffer.
*
* A memory buffer that is registered temporarily for the duration of the
* operation to be called.
*/
typedef struct {
void *buffer;
size_t size;
} TEEC_TempMemoryReference;

/**
* struct TEEC_RegisteredMemoryReference - use a pre-registered or
* pre-allocated shared memory block of memory to transfer data between
* a client application and trusted code.
*
* @param parent  Points to a shared memory structure. The memory reference
*                may utilize the whole shared memory or only a part of it.
*                Must not be NULL
*
* @param size    The size, in bytes, of the memory buffer.
*
* @param offset  The offset, in bytes, of the referenced memory region from
*                the start of the shared memory block.
*
*/
typedef struct {
TEEC_SharedMemory *parent;
size_t size;
size_t offset;
} TEEC_RegisteredMemoryReference;

/**
* 用于传输数据量少的场景
* struct TEEC_Value - Small raw data container
*
* Instead of allocating a shared memory buffer this structure can be used
* to pass small raw data between a client application and trusted code.
*
* @param a  The first integer value.
*
* @param b  The second second value.
*/
typedef struct {
uint32_t a;
uint32_t b;
} TEEC_Value;

/**
* union TEEC_Parameter - Memory container to be used when passing data between
*                        client application and trusted code.
*
* Either the client uses a shared memory reference, parts of it or a small raw
* data container.
*
* @param tmpref  A temporary memory reference only valid for the duration
*                of the operation.
*
* @param memref  The entire shared memory or parts of it.
*
* @param value   The small raw data container to use
*/
typedef union {
TEEC_TempMemoryReference tmpref;
TEEC_RegisteredMemoryReference memref;
TEEC_Value value;
} TEEC_Parameter;

/**
* struct TEEC_Session - Represents a connection between a client application
* and a trusted application.
*/
typedef struct {
/* Implementation defined */
TEEC_Context *ctx;
uint32_t session_id;
} TEEC_Session;

/**
* struct TEEC_Operation - Holds information and memory references used in
* TEEC_InvokeCommand().
*
* @param   started     Client must initialize to zero if it needs to cancel
*                      an operation about to be performed.
* @param   paramTypes  Type of data passed. Use TEEC_PARAMS_TYPE macro to
*                      create the correct flags.
*                      0 means TEEC_NONE is passed for all params.
* @param   params      Array of parameters of type TEEC_Parameter.
* @param   session     Internal pointer to the last session used by
*                      TEEC_InvokeCommand with this operation.
*
*/
typedef struct {
uint32_t started;
uint32_t paramTypes;
TEEC_Parameter params[TEEC_CONFIG_PAYLOAD_REF_COUNT];
/* Implementation-Defined */
TEEC_Session *session;
} TEEC_Operation;

三、接口函数及参数说明

//函数接口及参数说明
/**
* TEEC_InitializeContext() - Initializes a context holding connection
* information on the specific TEE, designated by the name string.

* @param name    A zero-terminated string identifying the TEE to connect to.
*                If name is set to NULL, the default TEE is connected to. NULL
*                is the only supported value in this version of the API
*                implementation.
*
* @param context The context structure which is to be initialized.
*
* @return TEEC_SUCCESS  The initialization was successful.
* @return TEEC_Result   Something failed.
*/
TEEC_Result TEEC_InitializeContext(const char *name, TEEC_Context *context);

/**
* TEEC_FinalizeContext() - Destroys a context holding connection information
* on the specific TEE.
*
* This function destroys an initialized TEE context, closing the connection
* between the client application and the TEE. This function must only be
* called when all sessions related to this TEE context have been closed and
* all shared memory blocks have been released.
*
* @param context       The context to be destroyed.
*/
void TEEC_FinalizeContext(TEEC_Context *context);

/**
* TEEC_OpenSession() - Opens a new session with the specified trusted
*                      application.
*
* @param context            The initialized TEE context structure in which
*                           scope to open the session.
* @param session            The session to initialize.
* @param destination        A structure identifying the trusted application
*                           with which to open a session.
*
* @param connectionMethod   The connection method to use.
* @param connectionData     Any data necessary to connect with the chosen
*                           connection method. Not supported, should be set to
*                           NULL.
* @param operation          An operation structure to use in the session. May
*                           be set to NULL to signify no operation structure
*                           needed.
*
* @param returnOrigin       A parameter which will hold the error origin if
*                           this function returns any value other than
*                           TEEC_SUCCESS.
*
* @return TEEC_SUCCESS      OpenSession successfully opened a new session.
* @return TEEC_Result       Something failed.
*
*/
TEEC_Result TEEC_OpenSession(TEEC_Context *context,
TEEC_Session *session,
const TEEC_UUID *destination,
uint32_t connectionMethod,
const void *connectionData,
TEEC_Operation *operation,
uint32_t *returnOrigin);

/**
* TEEC_CloseSession() - Closes the session which has been opened with the
* specific trusted application.
*
* @param session The opened session to close.
*/
void TEEC_CloseSession(TEEC_Session *session);

/**
* TEEC_InvokeCommand() - Executes a command in the specified trusted
* application.
*
* @param session        A handle to an open connection to the trusted
*                       application.
* @param commandID      Identifier of the command in the trusted application
*                       to invoke.
* @param operation      An operation structure to use in the invoke command.
*                       May be set to NULL to signify no operation structure
*                       needed.
* @param returnOrigin   A parameter which will hold the error origin if this
*                       function returns any value other than TEEC_SUCCESS.
*
* @return TEEC_SUCCESS  OpenSession successfully opened a new session.
* @return TEEC_Result   Something failed.
*/
TEEC_Result TEEC_InvokeCommand(TEEC_Session *session,
uint32_t commandID,
TEEC_Operation *operation,
uint32_t *returnOrigin);

/**
* TEEC_RegisterSharedMemory() - Register a block of existing memory as a
* shared block within the scope of the specified context.
*
* @param context    The initialized TEE context structure in which scope to
*                   open the session.
* @param sharedMem  pointer to the shared memory structure to register.
*
* @return TEEC_SUCCESS              The registration was successful.
* @return TEEC_ERROR_OUT_OF_MEMORY  Memory exhaustion.
* @return TEEC_Result               Something failed.
*/
TEEC_Result TEEC_RegisterSharedMemory(TEEC_Context *context,
TEEC_SharedMemory *sharedMem);

/**
* TEEC_AllocateSharedMemory() - Allocate shared memory for TEE.
*
* @param context     The initialized TEE context structure in which scope to
*                    open the session.
* @param sharedMem   Pointer to the allocated shared memory.
*
* @return TEEC_SUCCESS              The registration was successful.
* @return TEEC_ERROR_OUT_OF_MEMORY  Memory exhaustion.
* @return TEEC_Result               Something failed.
*/
TEEC_Result TEEC_AllocateSharedMemory(TEEC_Context *context,
TEEC_SharedMemory *sharedMem);

/**
* TEEC_ReleaseSharedMemory() - Free or deregister the shared memory.
*
* @param sharedMem  Pointer to the shared memory to be freed.
*/
void TEEC_ReleaseSharedMemory(TEEC_SharedMemory *sharedMemory);

/**
* TEEC_RequestCancellation() - Request the cancellation of a pending open
*                              session or command invocation.
*
* @param operation Pointer to an operation previously passed to open session
*                  or invoke.
*/
void TEEC_RequestCancellation(TEEC_Operation *operation);