From 9a175befedd6a14c8dfb8390a933c19c8056a599 Mon Sep 17 00:00:00 2001
From: rongli <rongli@nestlabs.com>
Date: Fri, 17 Mar 2017 00:04:51 +0800
Subject: [PATCH] Fix bugs in Announce (#1471)

---
 src/core/api/thread_api.cpp |  2 +-
 src/core/thread/mle.cpp     | 16 ++++++----------
 src/core/thread/mle.hpp     |  6 ++++--
 3 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/src/core/api/thread_api.cpp b/src/core/api/thread_api.cpp
index 464fb4a78..34f227591 100644
--- a/src/core/api/thread_api.cpp
+++ b/src/core/api/thread_api.cpp
@@ -589,7 +589,7 @@ ThreadError otThreadSetEnabled(otInstance *aInstance, bool aEnabled)
     {
         VerifyOrExit(aInstance->mThreadNetif.GetMac().GetPanId() != Mac::kPanIdBroadcast,
                      error = kThreadError_InvalidState);
-        error = aInstance->mThreadNetif.GetMle().Start(true);
+        error = aInstance->mThreadNetif.GetMle().Start(true, false);
     }
     else
     {
diff --git a/src/core/thread/mle.cpp b/src/core/thread/mle.cpp
index b83bca352..d3bf89060 100644
--- a/src/core/thread/mle.cpp
+++ b/src/core/thread/mle.cpp
@@ -202,7 +202,7 @@ exit:
     return error;
 }
 
-ThreadError Mle::Start(bool aEnableReattach)
+ThreadError Mle::Start(bool aEnableReattach, bool aAnnounceAttach)
 {
     ThreadError error = kThreadError_None;
 
@@ -223,7 +223,7 @@ ThreadError Mle::Start(bool aEnableReattach)
         mReattachState = kReattachStart;
     }
 
-    if (GetRloc16() == Mac::kShortAddrInvalid)
+    if (aAnnounceAttach || (GetRloc16() == Mac::kShortAddrInvalid))
     {
         BecomeChild(kMleAttachAnyPartition);
     }
@@ -562,7 +562,9 @@ ThreadError Mle::SetStateChild(uint16_t aRloc16)
     mNetif.GetIp6().SetForwardingEnabled(false);
     mNetif.GetIp6().mMpl.SetTimerExpirations(kMplChildDataMessageTimerExpirations);
 
-    if (mPreviousPanId != Mac::kPanIdBroadcast && (mDeviceMode & ModeTlv::kModeFFD))
+    // Once the Thread device receives the new Active Commissioning Dataset, the device MUST
+    // transmit its own Announce messages on the channel it was on prior to the attachment.
+    if (mPreviousPanId != Mac::kPanIdBroadcast)
     {
         mPreviousPanId = Mac::kPanIdBroadcast;
         mNetif.GetAnnounceBeginServer().SendAnnounce(1 << mPreviousChannel);
@@ -2448,12 +2450,6 @@ ThreadError Mle::HandleLeaderData(const Message &aMessage, const Ip6::MessageInf
         mNetif.GetPendingDataset().Clear(false);
     }
 
-    if (mPreviousPanId != Mac::kPanIdBroadcast && ((mDeviceMode & ModeTlv::kModeFFD) == 0))
-    {
-        mPreviousPanId = Mac::kPanIdBroadcast;
-        mNetif.GetAnnounceBeginServer().SendAnnounce(1 << mPreviousChannel);
-    }
-
     mRetrieveNewNetworkData = false;
 
 exit:
@@ -2993,7 +2989,7 @@ ThreadError Mle::HandleAnnounce(const Message &aMessage, const Ip6::MessageInfo
         mPreviousPanId = mNetif.GetMac().GetPanId();
         mNetif.GetMac().SetChannel(static_cast<uint8_t>(channel.GetChannel()));
         mNetif.GetMac().SetPanId(panid.GetPanId());
-        Start(false);
+        Start(false, true);
     }
     else
     {
diff --git a/src/core/thread/mle.hpp b/src/core/thread/mle.hpp
index 3d61f9f3b..49fbe6cc2 100644
--- a/src/core/thread/mle.hpp
+++ b/src/core/thread/mle.hpp
@@ -488,13 +488,15 @@ public:
     /**
      * This method starts the MLE protocol operation.
      *
-     * @param[in]  aEnableReattach  True to enable reattach process using stored dataset, False not.
+     * @param[in]  aEnableReattach True if reattach using stored dataset, or False if not.
+     * @param[in]  aAnnounceAttach True if attach on the announced thread network with newer active timestamp,
+     *                             or False if not.
      *
      * @retval kThreadError_None     Successfully started the protocol operation.
      * @retval kThreadError_Already  The protocol operation was already started.
      *
      */
-    ThreadError Start(bool aEnableReattach);
+    ThreadError Start(bool aEnableReattach, bool aAnnounceAttach);
 
     /**
      * This method stops the MLE protocol operation.