ipmid: channel: add max transfer size property

Each channel can have a different maximum transfer size. This should be
exposed so that it is easier to tell how many bytes it is possible to
send or receive on a given channel.

Change-Id: Ie277eb7a802edc1deeefe201a7560d371920f519
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
diff --git a/user_channel/channel_layer.hpp b/user_channel/channel_layer.hpp
index abaa0bf..87e791c 100644
--- a/user_channel/channel_layer.hpp
+++ b/user_channel/channel_layer.hpp
@@ -225,6 +225,14 @@
  */
 int getChannelActiveSessions(const uint8_t chNum);
 
+/** @brief determines maximum transfer size for a channel
+ *
+ *  @param[in] chNum - channel number
+ *
+ *  @return maximum bytes that can be transferred on this channel
+ */
+size_t getChannelMaxTransferSize(uint8_t chNum);
+
 /** @brief initializes channel management
  *
  *  @return IPMI_CC_OK for success, others for failure.