Add mctpreactor for dynamic configuration of MCTP networks
While mctpd[1] may see heavy use in projects such as OpenBMC, it
implements generic functionality necessary to operate MCTP as a
protocol. It therefore should be easy to use in other contexts, and so
it feels unwise to embed OpenBMC-specific details in its implementation.
Conversely, entity-manager's scope is to expose inventory and board
configuration. It externalises all other responsibilities for the sake
of stability and maintenance. While entity-manager is central to
OpenBMC's implementation and has little use in other contexts, embedding
details of how to configure mctpd in entity-manager exceeds its scope.
Thus we reach the design point of mctpreactor, an intermediary process
that encapsulates OpenBMC-specific and mctpd-specific behaviors to
constrain their dispersion in either direction. The design-point was
reached via discussion at [2].
mctpreactor tracks instances of transport-specific MCTP device
configurations[3] appearing as a result of inventory changes, and uses
them to assign endpoint IDs via mctpd.
The lifecycle of an MCTP device can be quite dynamic - mctpd provides
behaviors to recover[4] or remove endpoints from the network. Their
presence cannot be assumed. mctpreactor handles these events: If
a device is removed at the MCTP layer (as it may be unresponsive),
mctpreactor will periodically attempt to re-establish it as an endpoint
so long as the associated configuration on the entity-manager inventory
object remains exposed.
[1]: https://github.com/CodeConstruct/mctp/
[2]: https://github.com/CodeConstruct/mctp/pull/17
[3]: https://gerrit.openbmc.org/c/openbmc/entity-manager/+/70628
[4]: https://github.com/CodeConstruct/mctp/blob/7ec2f8daa3a8948066390aee621d6afa03f6ecd9/docs/endpoint-recovery.md
Change-Id: I5e362cf6e5ce80ce282bab48d912a1038003e236
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/service_files/meson.build b/service_files/meson.build
index 20bd84a..c3b23e0 100644
--- a/service_files/meson.build
+++ b/service_files/meson.build
@@ -12,6 +12,7 @@
['hwmon-temp', 'xyz.openbmc_project.hwmontempsensor.service'],
['ipmb', 'xyz.openbmc_project.ipmbsensor.service'],
['intrusion', 'xyz.openbmc_project.intrusionsensor.service'],
+ ['mctp', 'xyz.openbmc_project.mctpreactor.service'],
['mcu', 'xyz.openbmc_project.mcutempsensor.service'],
['nvme', 'xyz.openbmc_project.nvmesensor.service'],
['psu', 'xyz.openbmc_project.psusensor.service'],
diff --git a/service_files/xyz.openbmc_project.mctpreactor.service b/service_files/xyz.openbmc_project.mctpreactor.service
new file mode 100644
index 0000000..71a61fd
--- /dev/null
+++ b/service_files/xyz.openbmc_project.mctpreactor.service
@@ -0,0 +1,17 @@
+[Unit]
+Description=MCTP device configuration
+Requires=xyz.openbmc_project.EntityManager.service
+After=xyz.openbmc_project.EntityManager.service
+Requires=mctpd.service
+After=mctpd.service
+
+[Service]
+Type=dbus
+BusName=xyz.openbmc_project.MCTPReactor
+
+Restart=always
+RestartSec=5
+ExecStart=/usr/bin/mctpreactor
+
+[Install]
+WantedBy=multi-user.target