1 files changed, 140 insertions, 0 deletions
diff --git a/agent/sila/powerstate.cpp b/agent/sila/powerstate.cpp
new file mode 100644
index 0000000..d82ad23
--- /dev/null
+++ b/agent/sila/powerstate.cpp
@@ -0,0 +1,140 @@
+/**
+ * @brief SILA host power state implementation.
+ *
+ * This file is part of sila-snmp project.
+ *
+ * Copyright (c) 2022 SILA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+#include "data/scalar.hpp"
+#include "sila/sila_oid.hpp"
+#include "tracing.hpp"
+
+#include <net-snmp/net-snmp-config.h>
+#include <net-snmp/net-snmp-includes.h>
+#include <net-snmp/agent/net-snmp-agent-includes.h>
+
+#include "snmptrap.hpp"
+
+namespace sila
+{
+namespace host
+{
+namespace power
+{
+namespace state
+{
+using OID = phosphor::snmp::agent::OID;
+
+static const OID state_oid = SILA_OID(1, 1);
+static const OID notify_oid = SILA_OID(0, 1);
+
+// Values specified in the MIB file.
+constexpr int UNKNOWN = -1;
+constexpr int OFF = 0;
+constexpr int ON = 1;
+
+struct State : public phosphor::snmp::data::Scalar<std::string>
+{
+    static constexpr auto IFACE = "xyz.openbmc_project.State.Host";
+    static constexpr auto PATH = "/xyz/openbmc_project/state/host0";
+
+    State() :
+        phosphor::snmp::data::Scalar<std::string>(PATH, IFACE,
+                                                  "CurrentHostState", "")
+    {
+    }
+
+    void setValue(value_t& var)
+    {
+        auto prev = getValue();
+        phosphor::snmp::data::Scalar<std::string>::setValue(var);
+
+        auto curr = getValue();
+        if (prev != curr)
+        {
+            DEBUGMSGTL(("sila:powerstate",
+                        "Host power state changed: '%s' -> '%s'\n",
+                        prev.c_str(), curr.c_str()));
+
+            phosphor::snmp::agent::Trap trap(notify_oid);
+            trap.add_field(state_oid, toSNMPValue());
+            trap.send();
+        }
+    }
+
+    int toSNMPValue() const
+    {
+        auto value = getValue();
+        if (value == "xyz.openbmc_project.State.Host.HostState.Running")
+        {
+            return ON;
+        }
+        if (value == "xyz.openbmc_project.State.Host.HostState.Off")
+        {
+            return OFF;
+        }
+
+        return UNKNOWN;
+    }
+};
+
+static State state;
+
+/** @brief Handler for snmp requests */
+static int State_snmp_handler(netsnmp_mib_handler* /*handler*/,
+                              netsnmp_handler_registration* /*reginfo*/,
+                              netsnmp_agent_request_info* reqinfo,
+                              netsnmp_request_info* requests)
+{
+    DEBUGMSGTL(("sila:handle",
+                "Processing request (%d) for silaHostPowerState\n",
+                reqinfo->mode));
+
+    switch (reqinfo->mode)
+    {
+        case MODE_GET:
+            for (netsnmp_request_info* request = requests; request;
+                 request = request->next)
+            {
+                phosphor::snmp::agent::VariableList::set(request->requestvb,
+                                                         state.toSNMPValue());
+            }
+            break;
+    }
+
+    return SNMP_ERR_NOERROR;
+}
+
+void init()
+{
+    DEBUGMSGTL(("sila:init", "Initialize silaHostPowerState\n"));
+
+    state.update();
+
+    netsnmp_register_read_only_instance(netsnmp_create_handler_registration(
+        "silaHostPowerState", State_snmp_handler, state_oid.data(),
+        state_oid.size(), HANDLER_CAN_RONLY));
+}
+void destroy()
+{
+    DEBUGMSGTL(("sila:shutdown", "destroy silaHostPowerState\n"));
+    unregister_mib(const_cast<oid*>(state_oid.data()), state_oid.size());
+}
+
+} // namespace state
+} // namespace power
+} // namespace host
+} // namespace sila