[neighbor] add methods to check neighbor state (#4280)

src/core/api/thread_api.cpp

@@ -322,7 +322,7 @@ otError otThreadGetParentInfo(otInstance *aInstance, otRouterInfo *aParentInfo)
     aParentInfo->mLinkQualityOut = parent->GetLinkQualityOut();
     aParentInfo->mAge            = static_cast<uint8_t>(Time::MsecToSec(TimerMilli::GetNow() - parent->GetLastHeard()));
     aParentInfo->mAllocated      = true;
-    aParentInfo->mLinkEstablished = parent->GetState() == Neighbor::kStateValid;
+    aParentInfo->mLinkEstablished = parent->IsStateValid();
 
 #if !OPENTHREAD_CONFIG_REFERENCE_DEVICE_ENABLE
 exit:

src/core/mac/data_poll_sender.cpp

@@ -205,7 +205,7 @@ void DataPollSender::HandlePollSent(Mac::TxFrame &aFrame, otError aError)
         Get<MeshForwarder>().UpdateNeighborOnSentFrame(aFrame, aError, macDest);
     }
 
-    if (Get<Mle::MleRouter>().GetParentCandidate()->GetState() == Neighbor::kStateInvalid)
+    if (Get<Mle::MleRouter>().GetParentCandidate()->IsStateInvalid())
     {
         StopPolling();
         Get<Mle::MleRouter>().BecomeDetached();

src/core/mac/mac.cpp

@@ -1458,7 +1458,7 @@ otError Mac::ProcessReceiveSecurity(RxFrame &aFrame, const Address &aSrcAddr, Ne
         // the tag/MIC. Such a frame is later filtered in `RxDoneTask` which only allows MAC
         // Data Request frames from a child being restored.
 
-        if (aNeighbor->GetState() == Neighbor::kStateValid)
+        if (aNeighbor->IsStateValid())
         {
             if (keySequence < aNeighbor->GetKeySequence())
             {
@@ -1514,7 +1514,7 @@ otError Mac::ProcessReceiveSecurity(RxFrame &aFrame, const Address &aSrcAddr, Ne
     VerifyOrExit(memcmp(tag, aFrame.GetFooter(), tagLength) == 0, error = OT_ERROR_SECURITY);
 #endif
 
-    if ((keyIdMode == Frame::kKeyIdMode1) && (aNeighbor->GetState() == Neighbor::kStateValid))
+    if ((keyIdMode == Frame::kKeyIdMode1) && (aNeighbor->IsStateValid()))
     {
         if (aNeighbor->GetKeySequence() != keySequence)
         {

src/core/thread/child_table.cpp

@@ -130,7 +130,7 @@ Child *ChildTable::GetNewChild(void)
 
     for (uint16_t num = mMaxChildrenAllowed; num != 0; num--, child++)
     {
-        if (child->GetState() == Child::kStateInvalid)
+        if (child->IsStateInvalid())
         {
             child->Clear();
             ExitNow();
@@ -253,7 +253,7 @@ bool ChildTable::MatchesFilter(const Child &aChild, StateFilter aFilter)
     switch (aFilter)
     {
     case kInStateValid:
-        rval = (aChild.GetState() == Child::kStateValid);
+        rval = aChild.IsStateValid();
         break;
 
     case kInStateValidOrRestoring:
@@ -261,7 +261,7 @@ bool ChildTable::MatchesFilter(const Child &aChild, StateFilter aFilter)
         break;
 
     case kInStateChildIdRequest:
-        rval = (aChild.GetState() == Child::kStateChildIdRequest);
+        rval = aChild.IsStateChildIdRequest();
         break;
 
     case kInStateValidOrAttaching:
@@ -269,7 +269,7 @@ bool ChildTable::MatchesFilter(const Child &aChild, StateFilter aFilter)
         break;
 
     case kInStateAnyExceptInvalid:
-        rval = (aChild.GetState() != Child::kStateInvalid);
+        rval = !aChild.IsStateInvalid();
         break;
 
     case kInStateAnyExceptValidOrRestoring:

src/core/thread/indirect_sender.cpp

@@ -165,7 +165,7 @@ exit:
 
 void IndirectSender::HandleChildModeChange(Child &aChild, Mle::DeviceMode aOldMode)
 {
-    if (!aChild.IsRxOnWhenIdle() && (aChild.GetState() == Neighbor::kStateValid))
+    if (!aChild.IsRxOnWhenIdle() && (aChild.IsStateValid()))
     {
         SetChildUseShortAddress(aChild, true);
     }

src/core/thread/mle.cpp

@@ -1677,7 +1677,7 @@ void Mle::HandleAttachTimer(void)
         // parent.
 
         if ((linkQuality == 3 || mAttachState != kAttachStateParentRequestRouter) &&
-            mParentCandidate.GetState() == Neighbor::kStateParentResponse &&
+            mParentCandidate.IsStateParentResponse() &&
             (mRole != OT_DEVICE_ROLE_CHILD || mReceivedResponseFromParent || mParentRequestMode == kAttachBetter) &&
             SendChildIdRequest() == OT_ERROR_NONE)
         {
@@ -2723,7 +2723,7 @@ void Mle::HandleUdpReceive(Message &aMessage, const Ip6::MessageInfo &aMessageIn
         break;
     }
 
-    if (neighbor != NULL && neighbor->GetState() == Neighbor::kStateValid)
+    if (neighbor != NULL && neighbor->IsStateValid())
     {
         if (keySequence == neighbor->GetKeySequence())
         {
@@ -2918,7 +2918,7 @@ otError Mle::HandleAdvertisement(const Message &aMessage, const Ip6::MessageInfo
 
     case OT_DEVICE_ROLE_ROUTER:
     case OT_DEVICE_ROLE_LEADER:
-        if ((neighbor = Get<MleRouter>().GetNeighbor(macAddr)) != NULL && neighbor->GetState() == Neighbor::kStateValid)
+        if ((neighbor = Get<MleRouter>().GetNeighbor(macAddr)) != NULL && neighbor->IsStateValid())
         {
             isNeighbor = true;
         }
@@ -3288,8 +3288,7 @@ otError Mle::HandleParentResponse(const Message &aMessage, const Ip6::MessageInf
     // Continue to process the "ParentResponse" if it is from current
     // parent candidate to update the challenge and frame counters.
 
-    if ((mParentCandidate.GetState() == Neighbor::kStateParentResponse) &&
-        (mParentCandidate.GetExtAddress() != extAddress))
+    if (mParentCandidate.IsStateParentResponse() && (mParentCandidate.GetExtAddress() != extAddress))
     {
         // if already have a candidate parent, only seek a better parent
 
@@ -3875,11 +3874,11 @@ Neighbor *Mle::GetNeighbor(uint16_t aAddress)
 {
     Neighbor *rval = NULL;
 
-    if ((mParent.IsStateValidOrRestoring()) && (mParent.GetRloc16() == aAddress))
+    if (mParent.IsStateValidOrRestoring() && (mParent.GetRloc16() == aAddress))
     {
         rval = &mParent;
     }
-    else if ((mParentCandidate.GetState() == Neighbor::kStateValid) && (mParentCandidate.GetRloc16() == aAddress))
+    else if (mParentCandidate.IsStateValid() && (mParentCandidate.GetRloc16() == aAddress))
     {
         rval = &mParentCandidate;
     }
@@ -3891,11 +3890,11 @@ Neighbor *Mle::GetNeighbor(const Mac::ExtAddress &aAddress)
 {
     Neighbor *rval = NULL;
 
-    if ((mParent.IsStateValidOrRestoring()) && (mParent.GetExtAddress() == aAddress))
+    if (mParent.IsStateValidOrRestoring() && (mParent.GetExtAddress() == aAddress))
     {
         rval = &mParent;
     }
-    else if ((mParentCandidate.GetState() == Neighbor::kStateValid) && (mParentCandidate.GetExtAddress() == aAddress))
+    else if (mParentCandidate.IsStateValid() && (mParentCandidate.GetExtAddress() == aAddress))
     {
         rval = &mParentCandidate;
     }
@@ -3927,8 +3926,7 @@ Neighbor *Mle::GetNeighbor(const Mac::Address &aAddress)
 uint16_t Mle::GetNextHop(uint16_t aDestination) const
 {
     OT_UNUSED_VARIABLE(aDestination);
-    return (mParent.GetState() == Neighbor::kStateValid) ? mParent.GetRloc16()
-                                                         : static_cast<uint16_t>(Mac::kShortAddrInvalid);
+    return (mParent.IsStateValid()) ? mParent.GetRloc16() : static_cast<uint16_t>(Mac::kShortAddrInvalid);
 }
 
 bool Mle::IsRoutingLocator(const Ip6::Address &aAddress) const
@@ -3958,7 +3956,7 @@ Router *Mle::GetParentCandidate(void)
 {
     Router *rval;
 
-    if (mParentCandidate.GetState() == Neighbor::kStateValid)
+    if (mParentCandidate.IsStateValid())
     {
         rval = &mParentCandidate;
     }

src/core/thread/mle_router.cpp

@@ -495,7 +495,7 @@ otError MleRouter::SendLinkRequest(Neighbor *aNeighbor)
 
     case OT_DEVICE_ROLE_ROUTER:
     case OT_DEVICE_ROLE_LEADER:
-        if (aNeighbor == NULL || aNeighbor->GetState() != Neighbor::kStateValid)
+        if (aNeighbor == NULL || !aNeighbor->IsStateValid())
         {
             SuccessOrExit(error = AppendTlvRequest(*message, routerTlvs, sizeof(routerTlvs)));
         }
@@ -526,7 +526,7 @@ otError MleRouter::SendLinkRequest(Neighbor *aNeighbor)
     }
     else
     {
-        if (aNeighbor->GetState() != Neighbor::kStateValid)
+        if (!aNeighbor->IsStateValid())
         {
             aNeighbor->GenerateChallenge();
             SuccessOrExit(error = AppendChallenge(*message, aNeighbor->GetChallenge(), aNeighbor->GetChallengeSize()));
@@ -614,9 +614,9 @@ otError MleRouter::HandleLinkRequest(const Message &aMessage, const Ip6::Message
             // source is a router
             neighbor = mRouterTable.GetRouter(GetRouterId(rloc16));
             VerifyOrExit(neighbor != NULL, error = OT_ERROR_PARSE);
-            VerifyOrExit(neighbor->GetState() != Neighbor::kStateLinkRequest, error = OT_ERROR_ALREADY);
+            VerifyOrExit(!neighbor->IsStateLinkRequest(), error = OT_ERROR_ALREADY);
 
-            if (neighbor->GetState() != Neighbor::kStateValid)
+            if (!neighbor->IsStateValid())
             {
                 const otThreadLinkInfo *linkInfo = static_cast<const otThreadLinkInfo *>(aMessageInfo.GetLinkInfo());
 
@@ -641,7 +641,7 @@ otError MleRouter::HandleLinkRequest(const Message &aMessage, const Ip6::Message
     else
     {
         // lack of source address indicates router coming out of reset
-        VerifyOrExit((neighbor = GetNeighbor(macAddr)) != NULL && neighbor->GetState() == Neighbor::kStateValid &&
+        VerifyOrExit((neighbor = GetNeighbor(macAddr)) != NULL && neighbor->IsStateValid() &&
                          IsActiveRouter(neighbor->GetRloc16()),
                      error = OT_ERROR_DROP);
     }
@@ -688,9 +688,8 @@ otError MleRouter::SendLinkAccept(const Ip6::MessageInfo &aMessageInfo,
     Header::Command         command;
     uint8_t                 linkMargin;
 
-    command = (aNeighbor == NULL || aNeighbor->GetState() == Neighbor::kStateValid)
-                  ? Header::kCommandLinkAccept
-                  : Header::kCommandLinkAcceptAndRequest;
+    command = (aNeighbor == NULL || aNeighbor->IsStateValid()) ? Header::kCommandLinkAccept
+                                                               : Header::kCommandLinkAcceptAndRequest;
 
     VerifyOrExit((message = NewMleMessage()) != NULL, error = OT_ERROR_NO_BUFS);
     SuccessOrExit(error = AppendHeader(*message, command));
@@ -731,7 +730,7 @@ otError MleRouter::SendLinkAccept(const Ip6::MessageInfo &aMessageInfo,
         }
     }
 
-    if (aNeighbor != NULL && aNeighbor->GetState() != Neighbor::kStateValid)
+    if (aNeighbor != NULL && !aNeighbor->IsStateValid())
     {
         aNeighbor->GenerateChallenge();
 
@@ -1264,7 +1263,7 @@ otError MleRouter::HandleAdvertisement(const Message &aMessage, const Ip6::Messa
             {
                 router = mRouterTable.GetRouter(routerId);
 
-                if (router != NULL && router->GetState() == Neighbor::kStateValid)
+                if (router != NULL && router->IsStateValid())
                 {
                     processRouteTlv = true;
                 }
@@ -1294,8 +1293,8 @@ otError MleRouter::HandleAdvertisement(const Message &aMessage, const Ip6::Messa
         router = (macAddr == mParent.GetExtAddress()) ? &mParent : mRouterTable.GetRouter(routerId);
         VerifyOrExit(router != NULL);
 
-        if ((router->GetState() == Neighbor::kStateValid) && IsFullThreadDevice() &&
-            (mRouterSelectionJitterTimeout == 0) && (mRouterTable.GetActiveRouterCount() < mRouterUpgradeThreshold))
+        if (router->IsStateValid() && IsFullThreadDevice() && (mRouterSelectionJitterTimeout == 0) &&
+            (mRouterTable.GetActiveRouterCount() < mRouterUpgradeThreshold))
         {
             mRouterSelectionJitterTimeout = 1 + Random::NonCrypto::GetUint8InRange(0, mRouterSelectionJitter);
             ExitNow();
@@ -1344,8 +1343,7 @@ otError MleRouter::HandleAdvertisement(const Message &aMessage, const Ip6::Messa
                 }
             }
         }
-        else if (IsFullThreadDevice() && (router->GetState() != Neighbor::kStateValid) &&
-                 (router->GetState() != Neighbor::kStateLinkRequest) &&
+        else if (IsFullThreadDevice() && !router->IsStateValid() && !router->IsStateLinkRequest() &&
                  (mRouterTable.GetActiveLinkCount() < OPENTHREAD_CONFIG_MLE_CHILD_ROUTER_LINKS))
         {
             router->SetExtAddress(macAddr);
@@ -1391,7 +1389,7 @@ otError MleRouter::HandleAdvertisement(const Message &aMessage, const Ip6::Messa
         VerifyOrExit(router != NULL);
 
         // Send link request if no link to router
-        if ((router->GetState() != Neighbor::kStateValid) && (router->GetState() != Neighbor::kStateLinkRequest) &&
+        if (!router->IsStateValid() && !router->IsStateLinkRequest() &&
             (linkMargin >= OPENTHREAD_CONFIG_MLE_LINK_REQUEST_MARGIN_MIN))
         {
             router->SetExtAddress(macAddr);
@@ -1809,8 +1807,7 @@ void MleRouter::HandleStateUpdateTimer(void)
             otLogInfoMle("Child timeout expired");
             RemoveNeighbor(child);
         }
-        else if ((mRole == OT_DEVICE_ROLE_ROUTER || mRole == OT_DEVICE_ROLE_LEADER) &&
-                 (child.GetState() == Neighbor::kStateRestored))
+        else if ((mRole == OT_DEVICE_ROLE_ROUTER || mRole == OT_DEVICE_ROLE_LEADER) && child.IsStateRestored())
         {
             SendChildUpdateRequest(child);
         }
@@ -1830,7 +1827,7 @@ void MleRouter::HandleStateUpdateTimer(void)
 
         age = TimerMilli::GetNow() - router.GetLastHeard();
 
-        if (router.GetState() == Neighbor::kStateValid)
+        if (router.IsStateValid())
         {
 #if OPENTHREAD_CONFIG_MLE_SEND_LINK_REQUEST_ON_ADV_TIMEOUT == 0
 
@@ -1859,7 +1856,7 @@ void MleRouter::HandleStateUpdateTimer(void)
 
 #endif
         }
-        else if (router.GetState() == Neighbor::kStateLinkRequest)
+        else if (router.IsStateLinkRequest())
         {
             if (age >= kMaxLinkRequestTimeout)
             {
@@ -2161,7 +2158,7 @@ otError MleRouter::HandleChildIdRequest(const Message &         aMessage,
         RemoveNeighbor(*router);
     }
 
-    if (child->GetState() != Neighbor::kStateValid)
+    if (!child->IsStateValid())
     {
         child->SetState(Neighbor::kStateChildIdRequest);
     }
@@ -2260,7 +2257,7 @@ otError MleRouter::HandleChildUpdateRequest(const Message &         aMessage,
 
     // Not proceed if the Child Update Request is from the peer which is not the device's child or
     // which was the device's child but becomes invalid.
-    if (child == NULL || child->GetState() == Neighbor::kStateInvalid)
+    if (child == NULL || child->IsStateInvalid())
     {
         // For invalid non-sleepy child, Send Child Update Response with status TLV (error)
         if (mode.GetMode().IsRxOnWhenIdle())
@@ -2357,7 +2354,7 @@ otError MleRouter::HandleChildUpdateRequest(const Message &         aMessage,
         SetChildStateToValid(*child);
         child->SetKeySequence(aKeySequence);
     }
-    else if (child->GetState() == Neighbor::kStateValid)
+    else if (child->IsStateValid())
     {
         if (childDidChange)
         {
@@ -2937,7 +2934,7 @@ otError MleRouter::SendChildUpdateRequest(Child &aChild)
     SuccessOrExit(error = AppendActiveTimestamp(*message));
     SuccessOrExit(error = AppendPendingTimestamp(*message));
 
-    if (aChild.GetState() != Neighbor::kStateValid)
+    if (!aChild.IsStateValid())
     {
         SuccessOrExit(error = AppendTlvRequest(*message, tlvs, sizeof(tlvs)));
         aChild.GenerateChallenge();
@@ -3171,7 +3168,7 @@ void MleRouter::RemoveNeighbor(Neighbor &aNeighbor)
 
             RemoveStoredChild(aNeighbor.GetRloc16());
         }
-        else if (aNeighbor.GetState() == Neighbor::kStateValid)
+        else if (aNeighbor.IsStateValid())
         {
             Signal(OT_NEIGHBOR_TABLE_EVENT_ROUTER_REMOVED, aNeighbor);
             mRouterTable.RemoveNeighbor(static_cast<Router &>(aNeighbor));
@@ -3384,7 +3381,7 @@ uint16_t MleRouter::GetNextHop(uint16_t aDestination)
     if ((routeCost + GetLinkCost(router->GetNextHop())) < linkCost)
     {
         nextHop = mRouterTable.GetRouter(router->GetNextHop());
-        VerifyOrExit(nextHop != NULL && nextHop->GetState() != Neighbor::kStateInvalid);
+        VerifyOrExit(nextHop != NULL && !nextHop->IsStateInvalid());
 
         rval = GetRloc16(router->GetNextHop());
     }
@@ -3672,7 +3669,7 @@ otError MleRouter::GetNextNeighborInfo(otNeighborInfoIterator &aIterator, otNeig
                 break;
             }
 
-            if (child->GetState() == Neighbor::kStateValid)
+            if (child->IsStateValid())
             {
                 neighbor            = child;
                 aNeighInfo.mIsChild = true;
@@ -3691,7 +3688,7 @@ otError MleRouter::GetNextNeighborInfo(otNeighborInfoIterator &aIterator, otNeig
     {
         Router *router = mRouterTable.GetRouter(static_cast<uint8_t>(index));
 
-        if (router != NULL && router->GetState() == Neighbor::kStateValid)
+        if (router != NULL && router->IsStateValid())
         {
             neighbor            = router;
             aNeighInfo.mIsChild = false;
@@ -4266,7 +4263,7 @@ void MleRouter::FillConnectivityTlv(ConnectivityTlv &aTlv)
             continue;
         }
 
-        if (router.GetState() != Neighbor::kStateValid)
+        if (!router.IsStateValid())
         {
             // skip non-neighbor routers
             continue;
@@ -4440,7 +4437,7 @@ bool MleRouter::HasMinDowngradeNeighborRouters(void)
     {
         Router &router = *iter.GetRouter();
 
-        if (router.GetState() != Neighbor::kStateValid)
+        if (!router.IsStateValid())
         {
             continue;
         }
@@ -4480,7 +4477,7 @@ bool MleRouter::HasOneNeighborWithComparableConnectivity(const RouteTlv &aRoute,
         }
 
         // check if neighbor is valid
-        if (router.GetState() == Neighbor::kStateValid)
+        if (router.IsStateValid())
         {
             // if neighbor is just peer
             if (router.GetRouterId() == aRouterId)
@@ -4534,7 +4531,7 @@ exit:
 
 void MleRouter::SetChildStateToValid(Child &aChild)
 {
-    VerifyOrExit(aChild.GetState() != Neighbor::kStateValid);
+    VerifyOrExit(!aChild.IsStateValid());
 
     aChild.SetState(Neighbor::kStateValid);
     StoreChild(aChild);

src/core/thread/router_table.cpp

@@ -101,7 +101,7 @@ void RouterTable::ClearNeighbors(void)
     {
         Router &router = mRouters[index];
 
-        if (router.GetState() == Neighbor::kStateValid)
+        if (router.IsStateValid())
         {
             Get<Mle::MleRouter>().Signal(OT_NEIGHBOR_TABLE_EVENT_ROUTER_REMOVED, router);
         }
@@ -335,7 +335,7 @@ uint8_t RouterTable::GetActiveLinkCount(void) const
 
     for (const Router *router = GetFirstEntry(); router != NULL; router = GetNextEntry(router))
     {
-        if (router->GetState() == Neighbor::kStateValid)
+        if (router->IsStateValid())
         {
             activeLinks++;
         }
@@ -352,7 +352,7 @@ Router *RouterTable::GetNeighbor(uint16_t aRloc16)
 
     for (router = GetFirstEntry(); router != NULL; router = GetNextEntry(router))
     {
-        if (router->GetState() == Neighbor::kStateValid && router->GetRloc16() == aRloc16)
+        if (router->IsStateValid() && router->GetRloc16() == aRloc16)
         {
             ExitNow();
         }
@@ -370,7 +370,7 @@ Router *RouterTable::GetNeighbor(const Mac::ExtAddress &aExtAddress)
 
     for (router = GetFirstEntry(); router != NULL; router = GetNextEntry(router))
     {
-        if (router->GetState() == Neighbor::kStateValid && router->GetExtAddress() == aExtAddress)
+        if (router->IsStateValid() && router->GetExtAddress() == aExtAddress)
         {
             ExitNow();
         }
@@ -437,7 +437,7 @@ otError RouterTable::GetRouterInfo(uint16_t aRouterId, otRouterInfo &aRouterInfo
     aRouterInfo.mExtAddress      = router->GetExtAddress();
     aRouterInfo.mAllocated       = true;
     aRouterInfo.mNextHop         = router->GetNextHop();
-    aRouterInfo.mLinkEstablished = router->GetState() == Neighbor::kStateValid;
+    aRouterInfo.mLinkEstablished = router->IsStateValid();
     aRouterInfo.mPathCost        = router->GetCost();
     aRouterInfo.mLinkQualityIn   = router->GetLinkInfo().GetLinkQuality();
     aRouterInfo.mLinkQualityOut  = router->GetLinkQualityOut();
@@ -463,7 +463,7 @@ uint8_t RouterTable::GetNeighborCount(void) const
 
     for (const Router *router = GetFirstEntry(); router != NULL; router = GetNextEntry(router))
     {
-        if (router->GetState() == Neighbor::kStateValid)
+        if (router->IsStateValid())
         {
             count++;
         }
@@ -476,8 +476,7 @@ uint8_t RouterTable::GetLinkCost(Router &aRouter)
 {
     uint8_t rval = Mle::kMaxRouteCost;
 
-    VerifyOrExit(aRouter.GetRloc16() != Get<Mle::MleRouter>().GetRloc16() &&
-                 aRouter.GetState() == Neighbor::kStateValid);
+    VerifyOrExit(aRouter.GetRloc16() != Get<Mle::MleRouter>().GetRloc16() && aRouter.IsStateValid());
 
     rval = aRouter.GetLinkInfo().GetLinkQuality();
 

src/core/thread/topology.hpp

@@ -92,7 +92,39 @@ public:
     void SetState(State aState) { mState = static_cast<uint8_t>(aState); }
 
     /**
-     * This method indicates whether the neighbor/child is being restored.
+     * This method indicates whether the neighbor is in the Invalid state.
+     *
+     * @returns TRUE if the neighbor is in the Invalid state, FALSE otherwise.
+     *
+     */
+    bool IsStateInvalid(void) const { return (mState == kStateInvalid); }
+
+    /**
+     * This method indicates whether the neighbor is in the Child ID Request state.
+     *
+     * @returns TRUE if the neighbor is in the Child ID Request state, FALSE otherwise.
+     *
+     */
+    bool IsStateChildIdRequest(void) const { return (mState == kStateChildIdRequest); }
+
+    /**
+     * This method indicates whether the neighbor is in the Link Request state.
+     *
+     * @returns TRUE if the neighbor is in the Link Request state, FALSE otherwise.
+     *
+     */
+    bool IsStateLinkRequest(void) const { return (mState == kStateLinkRequest); }
+
+    /**
+     * This method indicates whether the neighbor is in the Parent Response state.
+     *
+     * @returns TRUE if the neighbor is in the Parent Response state, FALSE otherwise.
+     *
+     */
+    bool IsStateParentResponse(void) const { return (mState == kStateParentResponse); }
+
+    /**
+     * This method indicates whether the neighbor is being restored.
      *
      * @returns TRUE if the neighbor is being restored, FALSE otherwise.
      *
@@ -100,9 +132,25 @@ public:
     bool IsStateRestoring(void) const { return (mState == kStateRestored) || (mState == kStateChildUpdateRequest); }
 
     /**
-     * This method indicates whether the neighbor/child is in valid state or if it is being restored.
+     * This method indicates whether the neighbor is in the Restored state.
      *
-     * When in these states messages can be sent to and/or received from the neighbor/child.
+     * @returns TRUE if the neighbor is in the Restored state, FALSE otherwise.
+     *
+     */
+    bool IsStateRestored(void) const { return (mState == kStateRestored); }
+
+    /**
+     * This method indicates whether the neighbor is valid (frame counters are synchronized).
+     *
+     * @returns TRUE if the neighbor is valid, FALSE otherwise.
+     *
+     */
+    bool IsStateValid(void) const { return (mState == kStateValid); }
+
+    /**
+     * This method indicates whether the neighbor is in valid state or if it is being restored.
+     *
+     * When in these states messages can be sent to and/or received from the neighbor.
      *
      * @returns TRUE if the neighbor is in valid, restored, or being restored states, FALSE otherwise.
      *