From 1dfa50876fd5346df912567427b49551b97d3534 Mon Sep 17 00:00:00 2001
From: Shu Chen <chenshu@google.com>
Date: Thu, 24 Nov 2016 23:40:44 +0800
Subject: [PATCH] Increment the Commissioner Session ID when the Leader resigns
 an active Commissioner (#1010)

---
 src/core/meshcop/leader.cpp     | 19 +++++++++++++++----
 src/core/meshcop/leader_ftd.hpp |  2 ++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/core/meshcop/leader.cpp b/src/core/meshcop/leader.cpp
index 38b3bf790..517ea3d20 100644
--- a/src/core/meshcop/leader.cpp
+++ b/src/core/meshcop/leader.cpp
@@ -181,8 +181,7 @@ void Leader::HandleKeepAlive(Coap::Header &aHeader, Message &aMessage, const Ip6
     {
         responseState = StateTlv::kReject;
         mTimer.Stop();
-        mNetworkData.SetCommissioningData(NULL, 0);
-        otLogInfoMeshCoP("commissioner inactive");
+        ResignCommissioner();
     }
     else
     {
@@ -267,12 +266,24 @@ void Leader::HandleTimer(void)
 {
     VerifyOrExit(mNetif.GetMle().GetDeviceState() == Mle::kDeviceStateLeader, ;);
 
-    otLogInfoMeshCoP("commissioner inactive");
-    mNetworkData.SetCommissioningData(NULL, 0);
+    ResignCommissioner();
 
 exit:
     return;
 }
 
+void Leader::ResignCommissioner(void)
+{
+    CommissionerSessionIdTlv mCommissionerSessionId;
+
+    mCommissionerSessionId.Init();
+    mCommissionerSessionId.SetCommissionerSessionId(++mSessionId);
+
+    mNetworkData.SetCommissioningData(reinterpret_cast<uint8_t *>(&mCommissionerSessionId),
+                                      sizeof(Tlv) + mCommissionerSessionId.GetLength());
+
+    otLogInfoMeshCoP("commissioner inactive");
+}
+
 }  // namespace MeshCoP
 }  // namespace Thread
diff --git a/src/core/meshcop/leader_ftd.hpp b/src/core/meshcop/leader_ftd.hpp
index c234045dc..00d35d04c 100644
--- a/src/core/meshcop/leader_ftd.hpp
+++ b/src/core/meshcop/leader_ftd.hpp
@@ -104,6 +104,8 @@ private:
 
     static void HandleUdpReceive(void *aContext, otMessage aMessage, const otMessageInfo *aMessageInfo);
 
+    void ResignCommissioner(void);
+
     Coap::Resource mPetition;
     Coap::Resource mKeepAlive;
     Coap::Server &mCoapServer;