TPMCmd/Platform/src/RunCommand.c

/* Microsoft Reference Implementation for TPM 2.0
 *
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 *  Copyright (c) Microsoft Corporation
 *
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 *
 *  BSD License
 *
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 *  are permitted provided that the following conditions are met:
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 *  of conditions and the following disclaimer.
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//**Introduction
// This module provides the platform specific entry and fail processing. The
// _plat__RunCommand() function is used to call to ExecuteCommand() in the TPM code.
// This function does whatever processing is necessary to set up the platform 
// in anticipation of the call to the TPM including settup for error processing.
//
// The _plat__Fail() function is called when there is a failure in the TPM. The TPM
// code will have set the flag to indicate that the TPM is in failure mode.
// This call will then recursively call ExecuteCommand in order to build the
// failure mode response. When ExecuteCommand() returns to _plat__Fail(), the
// platform will do some platform specif operation to return to the environment in
// which the TPM is executing. For a simulator, setjmp/longjmp is used. For an OS,
// a system exit to the OS would be appropriate.

//** Includes and locals
#include "Platform.h"
#include <setjmp.h>
#include "ExecCommand_fp.h"

jmp_buf              s_jumpBuffer;

//** Functions

//***_plat__RunCommand()
// This version of RunCommand will set up a jum_buf and call ExecuteCommand(). If
// the command executes without failing, it will return and RunCommand will return.
// If there is a failure in the command, then _plat__Fail() is called and it will 
// longjump back to RunCommand which will call ExecuteCommand again. However, this
// time, the TPM will be in failure mode so ExecuteCommand will simply build
// a failure response and return.
LIB_EXPORT void
_plat__RunCommand(
    uint32_t         requestSize,   // IN: command buffer size
    unsigned char   *request,       // IN: command buffer
    uint32_t        *responseSize,  // IN/OUT: response buffer size
    unsigned char   **response      // IN/OUT: response buffer
    )
{
    setjmp(s_jumpBuffer);
    ExecuteCommand(requestSize, request, responseSize, response);
}
    

//***_plat__Fail()
// This is the platform depended failure exit for the TPM.
LIB_EXPORT NORETURN void
_plat__Fail(
    void
    )
{
    longjmp(&s_jumpBuffer[0], 1);
}