In case swtpm was to return a control channel message with an error code it
would often return less bytes than the full response. In some cases the
current reading of the returned bytes would get stuck since more bytes are
expected. Therefore, pass a separate parameter indicating how many bytes to
expect in case of an error and read that many bytes in a first step. Check
for an error code in the first 4 bytes and return if there is an error.
Read the rest in a 2nd step, if needed.

   Stefan


Stefan Berger (2):
  tpm: Use new ptm_cap_n structure for PTM_GET_CAPABILITY
  tpm_emulator: Read control channel response in 2 passes

 backends/tpm/tpm_emulator.c | 73 ++++++++++++++++++++++++++-----------
 backends/tpm/tpm_ioctl.h    | 13 ++++++-
 backends/tpm/trace-events   |  2 +-
 3 files changed, 65 insertions(+), 23 deletions(-)

-- 
2.47.0