tree 1c3e43d0894de6a7c72a05c2e8523f32ea393cf6
parent 0b566d54978e4462e51e01414bcfc13918efcb45
author Dhruvaraj Subhashchandran <dhruvaraj@in.ibm.com> 1638956903 -0600
committer Dhruvaraj Subhashchandran <dhruvaraj@in.ibm.com> 1687345768 -0500

Implement GetFileHandle in dump entry interface

Certain applications need to offload the dump in various
ways, for example, performing DMA transfer of the dump to
the host memory. These applications require direct access
to the file to read from the BMC storage.

This commit introduces the GetFileHandle method in the
dump entry interface. This method provides direct access
to the Unix file handle of the dump entry, facilitating
more direct read operations on the dump file.
The returned file descriptor is read-only, which ensures
the integrity of the dump file.

The definition of the file handle is moved from the
specific 'bmc_dump_entry' class to the parent 'dump_entry'
class. This allows all dump types inheriting from
'dump_entry' to use this new method, thus increasing
its utility across various dump types.

The introduction of this method primarily benefits PLDM
for offloading the dump to the host, and bmcweb for
offloading the dump to Redfish clients. By providing
a file handle instead of exposing the file path,
it resolves potential access issues for applications
running in non-root contexts.

Test:
Created a dump and made sure it reached host
successfully
Executed with additional traces
Jun 21 10:56:09 pldmd[1856]: Requesting file handle
Jun 21 10:56:09 pldmd[1856]: File handle received fd=9
Jun 21 10:56:09 pldmd[1856]: Transfer data rc= 0
Jun 21 10:56:09 phosphor-dump-manager[480]: File handle \
request
Jun 21 10:56:09 phosphor-dump-manager[480]: returning fd=11
Jun 21 10:56:09 pldmd[1856]: File handle received fd=9
Jun 21 10:56:09 pldmd[1856]: File read rc=15

In th host:
Service Processor Dump:
  Maximum file size:           0 (0x00000000) bytes (0 MBs)
  Dumps this PHYP IPL:         1
 Pending Dump:
  Dump ID:                     00000009
  File size:                   3749662 \
(0x000000000039371E) bytes (3 MBs)
  SP dump sub type:            0x000000000000000F BMC
  File name:                   \
BMCDUMP.1392A20.00000009.20230621105510
  Dump create time:            06/21/2023 10:55:10.00
  PHYP notify time:            06/21/2023 10:56:00.5918570000
  LP recipient:                1
  LP notify time:              06/21/2023 10:56:00.5918580000

Signed-off-by: Dhruvaraj Subhashchandran <dhruvaraj@in.ibm.com>
Change-Id: If398940b655b4d90688273f0c76a20d4ead61992