dsp: base: Don't extract MultipartReceive resp's CRC once complete

According to DSP0240 v1.2.0 - Table 17 MultipartReceive Request and
Response Message Format, `DataIntegrityChecksum` field:

- Shall be included with all part transfers.
- Shall be omitted in response to a request message where
TransferOperation was set to XFER_COMPLETE or XFER_ABORT.

The only possible TransferFlag in a response for a request, where
TransferOperation was set to `XFER_COMPLETE` or `XFER_ABORT`, is
`ACKNOWLEDGE_COMPLETION`. So this is the only condition to ignore the
`DataIntegrityChecksum` field.

In the current implementation, `DataIntegrityChecksum` field is only
extracted when `TransferOperation` is `END` or `START_AND_END` and this
is incorrect.

Therefore, this commit updates `decode_pldm_base_multipart_receive_resp`
function to not extract `DataIntegrityChecksum` only when `TransferFlag`
field is `ACKNOWLEDGE_COMPLETION`. This also adds 2 more unit tests for
the API, which are respectively decoding an `ACKNOWLEDGE_COMPLETION`
response with a redundant checksum field and decoding a
non-`ACKNOWLEDGE_COMPLETION` response without a checksum field.

Change-Id: I325a6393eaabfecc08f758dcae417470dde65efb
Fixes: 8836784f1e06 ("dsp: base: Add encode req & decode resp for MultipartReceive command")
Signed-off-by: Chau Ly <chaul@amperecomputing.com>
3 files changed
tree: de4cb3d04f2f9f17f24ba459c295027eba471af0
  1. abi/
  2. docs/
  3. evolutions/
  4. include/
  5. instance-db/
  6. scripts/
  7. src/
  8. subprojects/
  9. tests/
  10. tools/
  11. .clang-format
  12. .clang-tidy
  13. CHANGELOG.md
  14. CONTRIBUTING.md
  15. Doxyfile.in
  16. LICENSE
  17. meson.build
  18. meson.options
  19. OWNERS
  20. README.md
README.md

libpldm

This is a library which deals with the encoding and decoding of PLDM messages. It should be possible to use this library by projects other than OpenBMC, and hence certain constraints apply to it:

  • keeping it light weight
  • implementation in C
  • minimal dynamic memory allocations
  • endian-safe
  • no OpenBMC specific dependencies

Source files are named according to the PLDM Type, for eg base.[h/c], fru.[h/c], etc.

Given a PLDM command "foo", the library will provide the following API: For the Requester function:

encode_foo_req() - encode a foo request
decode_foo_resp() - decode a response to foo

For the Responder function:

decode_foo_req() - decode a foo request
encode_foo_resp() - encode a response to foo

The library also provides API to pack and unpack PLDM headers.

To Build

libpldm is configured and built using meson. Python's pip or pipx can be used to install a recent version on your machine:

pipx install meson

Once meson is installed:

meson setup build && meson compile -C build

To run unit tests

meson test -C build

Working with libpldm

Components of the library ABI[^1] (loosely, functions) are separated into three categories:

[^1]: "library API + compiler ABI = library ABI"

  1. Stable
  2. Testing
  3. Deprecated

Applications depending on libpldm should aim to only use functions from the stable category. However, this may not always be possible. What to do when required functions fall into the deprecated or testing categories is discussed in CONTRIBUTING.

Upgrading libpldm

libpldm is maintained with the expectation that users move between successive releases when upgrading. This constraint allows the library to reintroduce types and functions of the same name in subsequent releases in the knowledge that there are no remaining users of previous definitions. While strategies are employed to avoid breaking existing APIs unnecessarily, the library is still to reach maturity, and we must allow for improvements to be made in the design.