tools: split out the update handler

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I367ea961c98ec822d3200d101c4f5977d77e7402
diff --git a/tools/helper.cpp b/tools/helper.cpp
new file mode 100644
index 0000000..ad2c60d
--- /dev/null
+++ b/tools/helper.cpp
@@ -0,0 +1,107 @@
+/*
+ * Copyright 2019 Google Inc.
+ *
+ * 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 "helper.hpp"
+
+#include "status.hpp"
+#include "tool_errors.hpp"
+
+#include <chrono>
+#include <ipmiblob/blob_errors.hpp>
+#include <thread>
+
+namespace host_tool
+{
+
+/* Poll an open verification session.  Handling closing the session is not yet
+ * owned by this method.
+ */
+bool pollStatus(std::uint16_t session, ipmiblob::BlobInterface* blob)
+{
+    using namespace std::chrono_literals;
+
+    static constexpr auto verificationSleep = 5s;
+    ipmi_flash::ActionStatus result = ipmi_flash::ActionStatus::unknown;
+
+    try
+    {
+        static constexpr int commandAttempts = 20;
+        int attempts = 0;
+        bool exitLoop = false;
+
+        /* Reach back the current status from the verification service output.
+         */
+        while (attempts++ < commandAttempts)
+        {
+            ipmiblob::StatResponse resp = blob->getStat(session);
+
+            if (resp.metadata.size() != sizeof(std::uint8_t))
+            {
+                /* TODO: How do we want to handle the verification failures,
+                 * because closing the session to the verify blob has a special
+                 * as-of-yet not fully defined behavior.
+                 */
+                std::fprintf(stderr, "Received invalid metadata response!!!\n");
+            }
+
+            result = static_cast<ipmi_flash::ActionStatus>(resp.metadata[0]);
+
+            switch (result)
+            {
+                case ipmi_flash::ActionStatus::failed:
+                    std::fprintf(stderr, "failed\n");
+                    exitLoop = true;
+                    break;
+                case ipmi_flash::ActionStatus::unknown:
+                    std::fprintf(stderr, "other\n");
+                    break;
+                case ipmi_flash::ActionStatus::running:
+                    std::fprintf(stderr, "running\n");
+                    break;
+                case ipmi_flash::ActionStatus::success:
+                    std::fprintf(stderr, "success\n");
+                    exitLoop = true;
+                    break;
+                default:
+                    std::fprintf(stderr, "wat\n");
+            }
+
+            if (exitLoop)
+            {
+                break;
+            }
+            std::this_thread::sleep_for(verificationSleep);
+        }
+    }
+    catch (const ipmiblob::BlobException& b)
+    {
+        throw ToolException("blob exception received: " +
+                            std::string(b.what()));
+    }
+
+    /* TODO: If this is reached and it's not success, it may be worth just
+     * throwing a ToolException with a timeout message specifying the final
+     * read's value.
+     *
+     * TODO: Given that excepting from certain points leaves the BMC update
+     * state machine in an inconsistent state, we need to carefully evaluate
+     * which exceptions from the lower layers allow one to try and delete the
+     * blobs to rollback the state and progress.
+     */
+    return (result == ipmi_flash::ActionStatus::success);
+}
+
+} // namespace host_tool