requester: Add new APIs for instance ID allocation and freeing
This patch starts the move of instance id handling into libpldm.
Currently pldmd allocates instance ids, and exposes a DBus call for
external apps to get instance ids. It relies on exploiting a behaviour
of mctp-demux to reclaim used ids by monitoring all incoming PLDM
responses. When moving to AF_MCTP, PLDM messages are not broadcast to
all PLDM sockets, and so this method of reclaiming ids won't work
automatically.
As instance id handling is moving into libpldm eventually, we may as
well do that now rather than adding an additional step to address this
issue. So an allocate and free function for instance ids is added in
this patch. As this implementation uses file locking, we have the
feature of any ids belonging to a process that dies being automatically
reclaimed into the id pool.
Some context behind the file based range locking design for instance IDs
can be found here:
https://amboar.github.io/notes/2023/03/28/motivating-a-new-scheme-for-pldm-instance-id-management-in-openbmc.html
and
https://amboar.github.io/notes/2023/03/29/a-global-pldm-instance-id-allocator-for-libpldm.html
Change-Id: Ia19870b1bcae9e614bda6e475b290faa0b327a73
Signed-off-by: Rashmica Gupta <rashmica@linux.ibm.com>
diff --git a/include/libpldm/base.h b/include/libpldm/base.h
index 26e0825..7580efb 100644
--- a/include/libpldm/base.h
+++ b/include/libpldm/base.h
@@ -11,6 +11,8 @@
#include "pldm_types.h"
+typedef uint8_t pldm_tid_t;
+
/** @brief PLDM Types
*/
enum pldm_supported_types {