message: Add get bus function

Function to get the dbus bus from a dbus message.
Forward declare it and implement it in bus.hpp so
that the return type is sdbusplus::bus::bus.

Change-Id: Ice55c8ce484ae1b575e762cc0d9e2826b4ba6504
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>

2 files changed, 15 insertions, 0 deletions

diff --git a/sdbusplus/bus.hpp b/sdbusplus/bus.hpp
index d0536d7..5ec1ff7 100644
--- a/sdbusplus/bus.hpp
+++ b/sdbusplus/bus.hpp
@@ -211,4 +211,15 @@ inline bus new_system()
 
 } // namespace bus
 
+/** @brief Get the dbus bus from the message.
+ *
+ *  @return The dbus bus.
+ */
+inline auto message::message::get_bus()
+{
+    sd_bus* b = nullptr;
+    b = sd_bus_message_get_bus(_msg.get());
+    return bus::bus(sd_bus_ref(b));
+}
+
 } // namespace sdbusplus
diff --git a/sdbusplus/message.hpp b/sdbusplus/message.hpp
index 7ef81e6..8c9414e 100644
--- a/sdbusplus/message.hpp
+++ b/sdbusplus/message.hpp
@@ -96,6 +96,10 @@ struct message
         sdbusplus::message::read(_msg.get(), std::forward<Args>(args)...);
     }
 
+    /** @brief Get the dbus bus from the message. */
+    // Forward declare.
+    auto get_bus();
+
     /** @brief Get the signature of a message.
      *
      *  @return A [weak] pointer to the signature of the message.