From 20efc8dd1a4a9aa395b2f4f50d362976bba0dc2a Mon Sep 17 00:00:00 2001
From: rongli <rongli@nestlabs.com>
Date: Fri, 12 May 2017 10:30:24 +0800
Subject: [PATCH] Fix routing cost comparison issue when chosing BR (#1759)

* Fix routing cost comparison issue when chosing BR

* remove extra space

* update for comments
---
 src/core/thread/mle_router.cpp          | 20 ++++++++++++++++++++
 src/core/thread/mle_router_ftd.hpp      | 10 ++++++++++
 src/core/thread/mle_router_mtd.hpp      |  1 +
 src/core/thread/network_data_leader.cpp |  5 ++---
 tests/scripts/thread-cert/node_cli.py   |  2 +-
 5 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/src/core/thread/mle_router.cpp b/src/core/thread/mle_router.cpp
index ed95dcb3e..ee38550f5 100644
--- a/src/core/thread/mle_router.cpp
+++ b/src/core/thread/mle_router.cpp
@@ -3376,6 +3376,26 @@ exit:
     return rval;
 }
 
+uint8_t MleRouter::GetCost(uint16_t aRloc16)
+{
+    uint8_t routerId = GetRouterId(aRloc16);
+    uint8_t cost = GetLinkCost(routerId);
+    Router *router = GetRouter(routerId);
+    uint8_t routeCost;
+
+    VerifyOrExit(router != NULL && GetRouter(router->GetNextHop()) != NULL);
+
+    routeCost = GetRouteCost(aRloc16) + GetLinkCost(GetRouter(routerId)->GetNextHop());
+
+    if (cost > routeCost)
+    {
+        cost = routeCost;
+    }
+
+exit:
+    return cost;
+}
+
 uint8_t MleRouter::GetRouteCost(uint16_t aRloc16) const
 {
     uint8_t rval = kMaxRouteCost;
diff --git a/src/core/thread/mle_router_ftd.hpp b/src/core/thread/mle_router_ftd.hpp
index a72d1d65d..8f459b1ef 100644
--- a/src/core/thread/mle_router_ftd.hpp
+++ b/src/core/thread/mle_router_ftd.hpp
@@ -264,6 +264,16 @@ public:
      */
     uint8_t GetLinkCost(uint8_t aRouterId);
 
+    /**
+     * This method returns the minimum cost to the given router.
+     *
+     * @param[in]  aRloc16  The short address of the given router.
+     *
+     * @returns The minimum cost to the given router (via direct link or forwarding).
+     *
+     */
+    uint8_t GetCost(uint16_t aRloc16);
+
     /**
      * This method returns the ROUTER_SELECTION_JITTER value.
      *
diff --git a/src/core/thread/mle_router_mtd.hpp b/src/core/thread/mle_router_mtd.hpp
index d313a49c8..ad5ffc94f 100644
--- a/src/core/thread/mle_router_mtd.hpp
+++ b/src/core/thread/mle_router_mtd.hpp
@@ -69,6 +69,7 @@ public:
 
     uint8_t GetRouteCost(uint16_t) const { return 0; }
     uint8_t GetLinkCost(uint16_t) { return 0; }
+    uint8_t GetCost(uint16_t) { return 0; }
 
     uint8_t GetRouterIdSequence(void) const { return 0; }
 
diff --git a/src/core/thread/network_data_leader.cpp b/src/core/thread/network_data_leader.cpp
index b62ae3d24..b4e4cd2fb 100644
--- a/src/core/thread/network_data_leader.cpp
+++ b/src/core/thread/network_data_leader.cpp
@@ -329,8 +329,7 @@ ThreadError LeaderBase::ExternalRouteLookup(uint8_t aDomainId, const Ip6::Addres
                     if (rvalRoute == NULL ||
                         entry->GetPreference() > rvalRoute->GetPreference() ||
                         (entry->GetPreference() == rvalRoute->GetPreference() &&
-                         mNetif.GetMle().GetRouteCost(entry->GetRloc()) <
-                         mNetif.GetMle().GetRouteCost(rvalRoute->GetRloc())))
+                         mNetif.GetMle().GetCost(entry->GetRloc()) < mNetif.GetMle().GetCost(rvalRoute->GetRloc())))
                     {
                         rvalRoute = entry;
                         rval_plen = static_cast<uint8_t>(plen);
@@ -387,7 +386,7 @@ ThreadError LeaderBase::DefaultRouteLookup(PrefixTlv &aPrefix, uint16_t *aRloc16
             if (route == NULL ||
                 entry->GetPreference() > route->GetPreference() ||
                 (entry->GetPreference() == route->GetPreference() &&
-                 mNetif.GetMle().GetRouteCost(entry->GetRloc()) < mNetif.GetMle().GetRouteCost(route->GetRloc())))
+                 mNetif.GetMle().GetCost(entry->GetRloc()) < mNetif.GetMle().GetCost(route->GetRloc())))
             {
                 route = entry;
             }
diff --git a/tests/scripts/thread-cert/node_cli.py b/tests/scripts/thread-cert/node_cli.py
index 3590bc250..27a8af1d3 100644
--- a/tests/scripts/thread-cert/node_cli.py
+++ b/tests/scripts/thread-cert/node_cli.py
@@ -382,7 +382,7 @@ class otCli:
         self.pexpect.expect('Done')
 
     def remove_prefix(self, prefix):
-        cmd = ' prefix remove ' + prefix
+        cmd = 'prefix remove ' + prefix
         self.send_command(cmd)
         self.pexpect.expect('Done')