From 96de36385ae67b689fc574512234ce4916538e7c Mon Sep 17 00:00:00 2001
From: Krzysztof Bogucki <kristofbo@gmail.com>
Date: Wed, 13 Feb 2019 17:59:33 +0100
Subject: [PATCH] [ip6] messages sent to Service Locator will not be filtered
 out (#3585)

Messages sent to Service Locator will not be filtered out, when thread
control traffic filtering is enabled via SetReceiveIp6FilterEnabled().
---
 src/core/net/ip6.cpp         | 9 +++++----
 src/core/net/ip6_address.cpp | 6 ++++++
 src/core/net/ip6_address.hpp | 9 +++++++++
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/core/net/ip6.cpp b/src/core/net/ip6.cpp
index 9bfcf9b70..84c73f0f8 100644
--- a/src/core/net/ip6.cpp
+++ b/src/core/net/ip6.cpp
@@ -701,10 +701,11 @@ otError Ip6::ProcessReceiveCallback(const Message &    aMessage,
 
     if (mIsReceiveIp6FilterEnabled)
     {
-        // do not pass messages sent to an RLOC/ALOC
-        VerifyOrExit(!aMessageInfo.GetSockAddr().IsRoutingLocator() &&
-                         !aMessageInfo.GetSockAddr().IsAnycastRoutingLocator(),
-                     error = OT_ERROR_NO_ROUTE);
+        // do not pass messages sent to an RLOC/ALOC, except Service Locator
+        VerifyOrExit(
+            (!aMessageInfo.GetSockAddr().IsRoutingLocator() && !aMessageInfo.GetSockAddr().IsAnycastRoutingLocator()) ||
+                aMessageInfo.GetSockAddr().IsAnycastServiceLocator(),
+            error = OT_ERROR_NO_ROUTE);
 
         switch (aIpProto)
         {
diff --git a/src/core/net/ip6_address.cpp b/src/core/net/ip6_address.cpp
index afe61a666..4975755c9 100644
--- a/src/core/net/ip6_address.cpp
+++ b/src/core/net/ip6_address.cpp
@@ -130,6 +130,12 @@ bool Address::IsAnycastRoutingLocator(void) const
             mFields.m16[6] == HostSwap16(0xfe00) && mFields.m8[14] == kAloc16Mask);
 }
 
+bool Address::IsAnycastServiceLocator(void) const
+{
+    return IsAnycastRoutingLocator() && (mFields.m16[7] >= HostSwap16(Mle::kAloc16ServiceStart)) &&
+           (mFields.m16[7] <= HostSwap16(Mle::kAloc16ServiceEnd));
+}
+
 bool Address::IsSubnetRouterAnycast(void) const
 {
     return (mFields.m32[2] == 0 && mFields.m32[3] == 0);
diff --git a/src/core/net/ip6_address.hpp b/src/core/net/ip6_address.hpp
index 44a8f955b..e5af2f5fb 100644
--- a/src/core/net/ip6_address.hpp
+++ b/src/core/net/ip6_address.hpp
@@ -243,6 +243,15 @@ public:
      */
     bool IsAnycastRoutingLocator(void) const;
 
+    /**
+     * This method indicates whether or not the IPv6 address is an Anycast Service Locator.
+     *
+     * @retval TRUE   If the IPv6 address is an Anycast Service Locator.
+     * @retval FALSE  If the IPv6 address is not an Anycast Service Locator.
+     *
+     */
+    bool IsAnycastServiceLocator(void) const;
+
     /**
      * This method indicates whether or not the IPv6 address is Subnet-Router Anycast (RFC 4291),
      *