Attn: Refactor dbus calls for pel handling

Removed hard-coded system names and instead find system name by dbus
object path and interface. Add try/catch handling around dbus calls that
could throw exceptions.

Signed-off-by: Ben Tyner <ben.tyner@ibm.com>
Change-Id: I9cfe5fce858ba690fc9a7f0e61a4d249d5a1ef84
diff --git a/attn/attn_dbus.cpp b/attn/attn_dbus.cpp
new file mode 100644
index 0000000..72b637e
--- /dev/null
+++ b/attn/attn_dbus.cpp
@@ -0,0 +1,212 @@
+#include <attn_logging.hpp>
+
+#include <string>
+#include <vector>
+
+namespace attn
+{
+
+/**
+ * Create a dbus method
+ *
+ * Find the dbus service associated with the dbus object path and create
+ * a dbus method for calling the specified dbus interface and function.
+ *
+ * @param i_path - dbus object path
+ * @param i_interface - dbus method interface
+ * @param i_function - dbus interface function
+ * @param o_method - method that is created
+ * @return non-zero if error
+ *
+ **/
+int dbusMethod(const std::string& i_path, const std::string& i_interface,
+               const std::string& i_function,
+               sdbusplus::message::message& o_method)
+{
+    int rc = 1; // assume error
+
+    try
+    {
+        constexpr auto serviceFind   = "xyz.openbmc_project.ObjectMapper";
+        constexpr auto pathFind      = "/xyz/openbmc_project/object_mapper";
+        constexpr auto interfaceFind = "xyz.openbmc_project.ObjectMapper";
+        constexpr auto functionFind  = "GetObject";
+
+        auto bus = sdbusplus::bus::new_system(); // using system dbus
+
+        // method to find service from object path and object interface
+        auto method = bus.new_method_call(serviceFind, pathFind, interfaceFind,
+                                          functionFind);
+
+        // find the service for specified object path and interface
+        method.append(i_path.c_str());
+        method.append(std::vector<std::string>({i_interface}));
+        auto reply = bus.call(method);
+
+        // dbus call results
+        std::map<std::string, std::vector<std::string>> responseFindService;
+        reply.read(responseFindService);
+
+        // If we successfully found the service associated with the dbus object
+        // path and interface then create a method for the specified interface
+        // and function.
+        if (!responseFindService.empty())
+        {
+            auto service = responseFindService.begin()->first;
+
+            // return the method
+            o_method =
+                bus.new_method_call(service.c_str(), i_path.c_str(),
+                                    i_interface.c_str(), i_function.c_str());
+
+            rc = 0;
+        }
+        else
+        {
+            std::stringstream ss;
+            ss << "dbusMethod service not found:  " << i_path.c_str() << ", "
+               << i_interface.c_str();
+            trace<level::INFO>(ss.str().c_str());
+        }
+    }
+    catch (const sdbusplus::exception::SdBusError& e)
+    {
+        std::stringstream ss;
+        ss << "dbusMethod exception:  " << e.what();
+        trace<level::INFO>(ss.str().c_str());
+    }
+
+    return rc;
+}
+
+/** @brief Create a PEL for the specified event type */
+uint32_t createPel(const std::string& i_event,
+                   std::map<std::string, std::string>& i_additional,
+                   const std::vector<util::FFDCTuple>& i_ffdc)
+{
+    // CreatePELWithFFDCFiles returns plid
+    int plid = 0;
+
+    // Need to provide pid when using create or create-with-ffdc methods
+    i_additional.emplace("_PID", std::to_string(getpid()));
+
+    // Sdbus call specifics
+    constexpr auto interface = "org.open_power.Logging.PEL";
+    constexpr auto function  = "CreatePELWithFFDCFiles";
+
+    sdbusplus::message::message method;
+
+    if (0 == dbusMethod(pathLogging, interface, function, method))
+    {
+        try
+        {
+            // append additional dbus call paramaters
+            method.append(i_event, levelPelError, i_additional, i_ffdc);
+
+            // using system dbus
+            auto bus      = sdbusplus::bus::new_system();
+            auto response = bus.call(method);
+
+            // reply will be tuple containing bmc log id, platform log id
+            std::tuple<uint32_t, uint32_t> reply = {0, 0};
+
+            // parse dbus reply
+            response.read(reply);
+            plid = std::get<1>(reply); // platform log id is tuple "second"
+        }
+        catch (const sdbusplus::exception::SdBusError& e)
+        {
+            std::stringstream ss;
+            ss << "createPel exception:  " << e.what();
+            trace<level::INFO>(ss.str().c_str());
+        }
+    }
+
+    return plid; // platform log id or 0
+}
+
+/** @brief Create a PEL from raw PEL data */
+void createPelRaw(const std::vector<uint8_t>& i_buffer)
+{
+    // Create FFDC file from buffer data
+    util::FFDCFile pelFile{util::FFDCFormat::Text};
+    auto fd = pelFile.getFileDescriptor();
+    write(fd, i_buffer.data(), i_buffer.size());
+    lseek(fd, 0, SEEK_SET);
+
+    auto filePath = pelFile.getPath(); // path to ffdc file
+
+    // Additional data for log
+    std::map<std::string, std::string> additional;
+    additional.emplace("RAWPEL", filePath.string());
+    additional.emplace("_PID", std::to_string(getpid()));
+
+    // dbus specifics
+    constexpr auto interface = "xyz.openbmc_project.Logging.Create";
+    constexpr auto function  = "Create";
+
+    sdbusplus::message::message method;
+
+    if (0 == dbusMethod(pathLogging, interface, function, method))
+    {
+        try
+        {
+            // append additional dbus call parameters
+            method.append(eventPelTerminate, levelPelError, additional);
+
+            // using system dbus, no reply
+            auto bus = sdbusplus::bus::new_system();
+            bus.call_noreply(method);
+        }
+        catch (const sdbusplus::exception::SdBusError& e)
+        {
+            std::stringstream ss;
+            ss << "createPelRaw exception:  " << e.what();
+            trace<level::INFO>(ss.str().c_str());
+        }
+    }
+}
+
+/** @brief Get file descriptor of exisitng PEL */
+int getPel(const uint32_t i_pelId)
+{
+    // GetPEL returns file descriptor (int)
+    int fd = -1;
+
+    // dbus specifics
+    constexpr auto interface = "org.open_power.Logging.PEL";
+    constexpr auto function  = "GetPEL";
+
+    sdbusplus::message::message method;
+
+    if (0 == dbusMethod(pathLogging, interface, function, method))
+    {
+        try
+        {
+            // additional dbus call parameters
+            method.append(i_pelId);
+
+            // using system dbus
+            auto bus      = sdbusplus::bus::new_system();
+            auto response = bus.call(method);
+
+            // reply will be a unix file descriptor
+            sdbusplus::message::unix_fd reply;
+
+            // parse dbus reply
+            response.read(reply);
+
+            fd = dup(reply); // need to copy (dup) the file descriptor
+        }
+        catch (const sdbusplus::exception::SdBusError& e)
+        {
+            std::stringstream ss;
+            ss << "getPel exception:  " << e.what();
+            trace<level::INFO>(ss.str().c_str());
+        }
+    }
+
+    return fd; // file descriptor or -1
+}
+
+} // namespace attn