look up channel from D-Bus connection

With a single IPMI execution queue and multiple bridges, it is important
for the queue to be able to map the incoming D-Bus message to a channel.
Each bridge should request a well-known name of the form
"xyz.openbmc_project.Ipmi.Channel.<name>" where name is the name field
in the /usr/share/ipmi-providers/channel_config.json file.

The mapping is done by registering a name change listener on D-Bus and
then doing some name lookups via the D-Bus interface to match well-known
names to unique names. Then, each incoming messages comes from a
unique-named sender and can be resolved to which channel it came from.

For now, any unmapped channels will show up as INTRABMC, which is not
ideal, but should not break things until the bridges can be converted to
the correct name and D-Bus API.

Tested-by: run ipmid, start and stop bridges named
           xyz.openbmc_project.Ipmi.Channel.<NAME> and see the messages
           show that a new channel has been mapped. Then, with commands
           that use the ipmi::Context, the correct channel shows up.

Change-Id: I3e6bbfbf2e068020e07eeafe64eb09d70c03dc65
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/user_channel/channel_layer.hpp b/user_channel/channel_layer.hpp
index 1a8d64c..4308794 100644
--- a/user_channel/channel_layer.hpp
+++ b/user_channel/channel_layer.hpp
@@ -24,6 +24,7 @@ namespace ipmi
 
 static constexpr uint8_t maxIpmiChannels = 16;
 static constexpr uint8_t currentChNum = 0xE;
+static constexpr uint8_t invalidChannel = 0xff;
 
 /**
  * @enum IPMI return codes specific to channel (refer spec se 22.22 response
@@ -367,4 +368,12 @@ ipmi_ret_t getChannelEnabledAuthType(const uint8_t chNum, const uint8_t priv,
  */
 std::string getChannelName(const uint8_t chNum);
 
+/** @brief Retrieves the LAN channel number from the IPMI channel name
+ *
+ *  @param[in] chName - IPMI channel name (i.e. eth0)
+ *
+ *  @return the LAN channel number
+ */
+uint8_t getChannelByName(const std::string& chName);
+
 } // namespace ipmi