tcti-device: enable nonblocking mode on tcti-device

Enable non-blocking mode on tcti-device. This new feature
requires the TPM driver to support asynchronous mode of operation.
(As of kernel v3.18 the driver doesn't support it)

It is therefor configure time enabled by a new flag called
enable-tcti-device-async (off by default)

There are two places where the new flag changes the behavior:
1. In tcti_device_get_poll_handles(), where if the flag is enabled,
   the function will populate handles with the tcti_dev->fd,
   set num_handles to 1, and return TSS2_RC_SUCCESS.
   If the flag is not enabled the function returns
   TSS2_TCTI_RC_NOT_IMPLEMENTED.
2. In tcti_device_receive(), where if the flag is not enabled
   the only acceptable timeout value is TSS2_TCTI_TIMEOUT_BLOCK,
   to enforce synchronous mode. If the flag is enabled the valid
   timeout values are: -1 to block forever, 0 for nonblocking,
   and any positive value as the actual timeout value in milliseconds.

The device interface will always be open in non-blocking mode
as the flag is ignored by the driver and invoking poll() currently
always returns with the POLLIN flag set.

When this feature will be supported by the driver and the
enable-tcti-device-async flag is not enabled the behavior
doesn't change because it it enforced to be synchronous
in tcti_device_get_poll_handles(), but if the flag is enabled
it will enable the asynchronous behavior of the tcti-device module.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
3 files changed
tree: b2fc270e63d2206934a0fca1de556b8efde592e8
  1. dist/
  2. doc/
  3. include/
  4. lib/
  5. m4/
  6. man/
  7. script/
  8. src/
  9. test/
  10. .appveyor.yml
  11. .gitattributes
  12. .gitignore
  13. .travis.yml
  14. bootstrap
  15. CHANGELOG.md
  16. configure.ac
  17. CONTRIBUTING.md
  18. Dockerfile
  19. Doxyfile.in
  20. INSTALL.md
  21. LICENSE
  22. MAINTAINERS
  23. Makefile-test.am
  24. Makefile.am
  25. README.md
  26. RELEASE.md
  27. tpm2-tss.sln
README.md

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Overview

This repository hosts source code implementing the Trusted Computing Group's (TCG) TPM2 Software Stack (TSS). This stack consists of the following layers from top to bottom:

  • Enhanced System API (ESAPI) as described in the TSS 2.0 Enhanced System API (ESAPI) Specification. This API is a 1-to-1 mapping of the TPM2 commands documented in Part 3 of the TPM2 specification. Additionally there are asynchronous versions of each command. In addition to SAPI, the ESAPI performs tracking of meta data for TPM object and automatic calculation of session based authorization and encryption values. Both the synchronous and asynchronous API are exposed through a single library: libtss2-esys.
  • System API (SAPI) as described in the system level API and TPM command transmission interface specification. This API is a 1-to-1 mapping of the TPM2 commands documented in Part 3 of the TPM2 specification. Additionally there are asynchronous versions of each command. These asynchronous variants may be useful for integration into event-driven programming environments. Both the synchronous and asynchronous API are exposed through a single library: libtss2-sys.
  • Marshaling/Unmarshaling (MU) as described in the TCG TSS 2.0 Marshaling/Unmarshaling API Specification. This API provides a set of marshaling and unmarshaling functions for all data types define by the TPM library specification. The Marshaling/Unmarshaling API is exposed through a library called libtss2-mu.
  • TPM Command Transmission Interface (TCTI) that is described in the same specification. This API provides a standard interface to transmit / receive TPM command / response buffers. It is expected that any number of libraries implementing the TCTI API will be implemented as a way to abstract various platform specific IPC mechanisms. Currently this repository provides two TCTI implementations: libtss2-tcti-device and libtss2-tcti-mssim. The former should be used for direct access to the TPM through the Linux kernel driver. The latter implements the protocol exposed by the Microsoft software TPM2 simulator.
  • The TCG TSS 2.0 Overview and Common Structures Specification forms the basis for all implementations in this project. NOTE: We deviate from this draft of the specification by increasing the value of TPM2_NUM_PCR_BANKS from 3 to 16 to ensure compatibility with TPM2 implementations that have enabled a lareger than typical number of PCR banks. This larger value for TPM2_NUM_PCR_BANKS is expected to be included in a future revision of the specification.

Build and Installation Instructions:

Instructions to build and install tpm2-tss are available in the INSTALL file.

Getting in Touch:

If you're looking to discuss the source code in this project or get some questions answered you should join the 01.org TPM2 mailing list: https://lists.01.org/mailman/listinfo/tpm2. We also have an IRC channel set up on FreeNode called #tpm2.0-tss.

Test Suite

This repository contains a test suite intended to exercise the TCTI, SAPI and ESAPI code. This test suite is not intended to test a TPM implementation, so this test suite should only be run against a TPM simulator. If this test suite is executed against a TPM other than the software simulator it may cause damage to the TPM (NV storage wear out, etc.). You have been warned.

Simulator

The TPM library specification contains reference code sufficient to construct a software TPM 2.0 simulator. This code was provided by Microsoft and they provide a binary download for Windows here. IBM has repackaged this code with a few Makefiles so that the Microsoft code can be built and run on Linux systems. The Linux version of the Microsoft TPM 2.0 simulator can be obtained here. Once you've downloaded and successfully built and execute the simulator it will, by default, be accepting connections on the localhost, TCP ports 2321 and 2322.

Issues building or running the simulator should be reported to the IBM software TPM2 project.

NOTE: The Intel TCG TSS is currently tested against version 974 of the simulator. Compatibility with later versions has not yet been tested.

Testing

To test the various TCTI, SAPI and ESAPI api calls, unit and integration tests can be run by configuring the build to enable unit testing and running the "check" build target. It is recommended to use a simulator for testing, and the simulator will be automatically launched by the tests. Please review the dependency list in INSTALL for dependencies when building the test suite.

$ ./configure --enable-unit --enable-integration
$ make -j$(nproc) check

This will generate a file called "test-suite.log" in the root of the build directory.

Please report failures in a Github 'issue' with a full log of the test run.

NOTE: The unit and integration tests can be enabled independently. The --enable-unit option controls unit tests, and --enable-integration controls the integration tests.

Architecture/Block Diagram

SAPI library, TAB/RM, and Test Code Block Diagram: Architecture Block Diagram

Project Layout

├── doc : various bits of documentation
├── include : header files installed in $(includedir)
│ └── tss2 : all public headers for this project
├── lib : data files used by the build or installed into $(libdir)
├── m4 : autoconf support macros
├── man : man pages
├── script : scripts used by the build or CI
├── src : all source files
│ ├── tss2-esys : enhanced system API (ESAPI) implementation
│ │   └── api : ESAPI TPM API implementation
│ ├── tss2-mu : TPM2 type marshaling/unmarshaling (MU) API implementation
│ ├── tss2-sys : system API (SAPI) implementation
│ │   └── api : SAPI public API implementation
│ ├── tss2-tcti : TCTI implementations for device and mssim
│ └── util : Internal utility library (e.g. logging framework)
└── test : test code
   ├── integration : integration test harness and test cases
   ├── tpmclient : monolithic, legacy test application
   └── unit : unit tests