netipmid: Support usesolkeepalive option

ipmitool keeps SOL session active by sending Get Device ID
command or using SOL packet to keep the session active. We are
adding support for keeping the SOL session active by using SOL
packet in which case ipmitool would send a SOL payload with no
character data and a valid SOL sequence number, the BMC would
respond with acknowledgement for that sequence number.

Resolves openbmc/openbmc#2101

Change-Id: Ia10e622e761e0de3530e3cc8bc2148a477ffd4ba
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/sol/sol_context.cpp b/sol/sol_context.cpp
index c00d01c..08be77b 100644
--- a/sol/sol_context.cpp
+++ b/sol/sol_context.cpp
@@ -95,6 +95,14 @@ void Context::processInboundPayload(uint8_t seqNum,
             acceptedCount = input.size();
         }
     }
+    /*
+     * SOL payload with no character data and valid sequence number can be used
+     * as method to keep the SOL session active.
+     */
+    else if (input.empty() && seqNum)
+    {
+        respAckSeqNum = seqNum;
+    }
 
     if (seqNum != 0)
     {