From ab57ca2f44b4d74fd47d19dd065d95b0ca5d7cb4 Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Wed, 18 May 2022 15:35:05 -0700
Subject: [PATCH] [ip6] simplify `Ip6::ShouldForwardToThread()` (#7706)

---
 src/core/net/ip6.cpp | 32 +++++++++-----------------------
 1 file changed, 9 insertions(+), 23 deletions(-)

diff --git a/src/core/net/ip6.cpp b/src/core/net/ip6.cpp
index 3f5ec0de3..b510fb12c 100644
--- a/src/core/net/ip6.cpp
+++ b/src/core/net/ip6.cpp
@@ -1309,43 +1309,29 @@ exit:
 
 bool Ip6::ShouldForwardToThread(const MessageInfo &aMessageInfo, bool aFromHost) const
 {
-    OT_UNUSED_VARIABLE(aFromHost);
+    bool shouldForward = false;
 
-    bool rval = false;
-
-    if (aMessageInfo.GetSockAddr().IsMulticast())
+    if (aMessageInfo.GetSockAddr().IsMulticast() || aMessageInfo.GetSockAddr().IsLinkLocal())
     {
-        // multicast
-        ExitNow(rval = true);
-    }
-    else if (aMessageInfo.GetSockAddr().IsLinkLocal())
-    {
-        // on-link link-local address
-        ExitNow(rval = true);
+        shouldForward = true;
     }
     else if (IsOnLink(aMessageInfo.GetSockAddr()))
     {
-        // on-link global address
 #if OPENTHREAD_FTD && OPENTHREAD_CONFIG_BACKBONE_ROUTER_DUA_NDPROXYING_ENABLE
-        ExitNow(rval = (aFromHost ||
-                        !Get<BackboneRouter::Manager>().ShouldForwardDuaToBackbone(aMessageInfo.GetSockAddr())));
+        shouldForward =
+            (aFromHost || !Get<BackboneRouter::Manager>().ShouldForwardDuaToBackbone(aMessageInfo.GetSockAddr()));
 #else
-        ExitNow(rval = true);
+        OT_UNUSED_VARIABLE(aFromHost);
+        shouldForward = true;
 #endif
     }
     else if (Get<ThreadNetif>().RouteLookup(aMessageInfo.GetPeerAddr(), aMessageInfo.GetSockAddr(), nullptr) ==
              kErrorNone)
     {
-        // route
-        ExitNow(rval = true);
-    }
-    else
-    {
-        ExitNow(rval = false);
+        shouldForward = true;
     }
 
-exit:
-    return rval;
+    return shouldForward;
 }
 
 const Netif::UnicastAddress *Ip6::SelectSourceAddress(MessageInfo &aMessageInfo)