From e55789a3f665de4416dc4809e4a8934266110ffd Mon Sep 17 00:00:00 2001
From: fgo <fgo@ableton.com>
Date: Tue, 19 Sep 2023 15:15:31 +0200
Subject: [PATCH] Return IPv6 addresses when scanning

---
 .../ableton/platforms/posix/ScanIpIfAddrs.hpp | 41 +++++++++++++------
 .../platforms/windows/ScanIpIfAddrs.hpp       | 38 ++++++++++++++---
 2 files changed, 61 insertions(+), 18 deletions(-)

diff --git a/include/ableton/platforms/posix/ScanIpIfAddrs.hpp b/include/ableton/platforms/posix/ScanIpIfAddrs.hpp
index 4e59045e..ba07dc5f 100644
--- a/include/ableton/platforms/posix/ScanIpIfAddrs.hpp
+++ b/include/ableton/platforms/posix/ScanIpIfAddrs.hpp
@@ -22,7 +22,9 @@
 #include <ableton/discovery/AsioTypes.hpp>
 #include <arpa/inet.h>
 #include <ifaddrs.h>
+#include <map>
 #include <net/if.h>
+#include <string>
 #include <vector>
 
 namespace ableton
@@ -77,31 +79,46 @@ struct ScanIpIfAddrs
   std::vector<discovery::IpAddress> operator()()
   {
     std::vector<discovery::IpAddress> addrs;
+    std::map<std::string, discovery::IpAddress> IpInterfaceNames;
 
     detail::GetIfAddrs getIfAddrs;
-    getIfAddrs.withIfAddrs([&addrs](const struct ifaddrs& interfaces) {
+    getIfAddrs.withIfAddrs([&addrs, &IpInterfaceNames](const struct ifaddrs& interfaces) {
       const struct ifaddrs* interface;
       for (interface = &interfaces; interface; interface = interface->ifa_next)
       {
         auto addr = reinterpret_cast<const struct sockaddr_in*>(interface->ifa_addr);
-        if (addr && interface->ifa_flags & IFF_UP)
+        if (addr && interface->ifa_flags & IFF_RUNNING && addr->sin_family == AF_INET)
         {
-          if (addr->sin_family == AF_INET)
-          {
-            auto bytes = reinterpret_cast<const char*>(&addr->sin_addr);
-            addrs.emplace_back(discovery::makeAddress<discovery::IpAddressV4>(bytes));
-          }
-          else if (addr->sin_family == AF_INET6)
+          auto bytes = reinterpret_cast<const char*>(&addr->sin_addr);
+          auto address = discovery::makeAddress<discovery::IpAddressV4>(bytes);
+          addrs.emplace_back(std::move(address));
+          IpInterfaceNames.insert(std::make_pair(interface->ifa_name, address));
+        }
+      }
+    });
+
+    getIfAddrs.withIfAddrs([&addrs, &IpInterfaceNames](const struct ifaddrs& interfaces) {
+      const struct ifaddrs* interface;
+      for (interface = &interfaces; interface; interface = interface->ifa_next)
+      {
+        auto addr = reinterpret_cast<const struct sockaddr_in*>(interface->ifa_addr);
+        if (addr && interface->ifa_flags & IFF_RUNNING && addr->sin_family == AF_INET6)
+        {
+          auto addr6 = reinterpret_cast<const struct sockaddr_in6*>(addr);
+          auto bytes = reinterpret_cast<const char*>(&addr6->sin6_addr);
+          auto scopeId = addr6->sin6_scope_id;
+          auto address = discovery::makeAddress<discovery::IpAddressV6>(bytes, scopeId);
+          if (IpInterfaceNames.find(interface->ifa_name) != IpInterfaceNames.end()
+              && !address.is_loopback() && address.is_link_local())
           {
-            auto addr6 = reinterpret_cast<const struct sockaddr_in6*>(addr);
-            auto bytes = reinterpret_cast<const char*>(&addr6->sin6_addr);
-            addrs.emplace_back(discovery::makeAddress<discovery::IpAddressV6>(bytes));
+            addrs.emplace_back(std::move(address));
           }
         }
       }
     });
+
     return addrs;
-  }
+  };
 };
 
 } // namespace posix
diff --git a/include/ableton/platforms/windows/ScanIpIfAddrs.hpp b/include/ableton/platforms/windows/ScanIpIfAddrs.hpp
index 0d79f7e5..229486e9 100644
--- a/include/ableton/platforms/windows/ScanIpIfAddrs.hpp
+++ b/include/ableton/platforms/windows/ScanIpIfAddrs.hpp
@@ -21,7 +21,9 @@
 
 #include <ableton/discovery/AsioTypes.hpp>
 #include <iphlpapi.h>
+#include <map>
 #include <stdio.h>
+#include <string>
 #include <vector>
 #include <winsock2.h>
 #include <ws2tcpip.h>
@@ -101,9 +103,10 @@ struct ScanIpIfAddrs
   std::vector<discovery::IpAddress> operator()()
   {
     std::vector<discovery::IpAddress> addrs;
+    std::map<std::string, discovery::IpAddress> IpInterfaceNames;
 
     detail::GetIfAddrs getIfAddrs;
-    getIfAddrs.withIfAddrs([&addrs](const IP_ADAPTER_ADDRESSES& interfaces) {
+    getIfAddrs.withIfAddrs([&](const IP_ADAPTER_ADDRESSES& interfaces) {
       const IP_ADAPTER_ADDRESSES* networkInterface;
       for (networkInterface = &interfaces; networkInterface;
            networkInterface = networkInterface->Next)
@@ -118,18 +121,41 @@ struct ScanIpIfAddrs
             SOCKADDR_IN* addr4 =
               reinterpret_cast<SOCKADDR_IN*>(address->Address.lpSockaddr);
             auto bytes = reinterpret_cast<const char*>(&addr4->sin_addr);
-            addrs.emplace_back(discovery::makeAddress<discovery::IpAddressV4>(bytes));
+            auto ipv4address = discovery::makeAddress<discovery::IpAddressV4>(bytes);
+            addrs.emplace_back(ipv4address);
+            IpInterfaceNames.insert(
+              std::make_pair(networkInterface->AdapterName, ipv4address));
           }
-          else if (AF_INET6 == family)
+        }
+      }
+    });
+
+    getIfAddrs.withIfAddrs([&](const IP_ADAPTER_ADDRESSES& interfaces) {
+      const IP_ADAPTER_ADDRESSES* networkInterface;
+      for (networkInterface = &interfaces; networkInterface;
+           networkInterface = networkInterface->Next)
+      {
+        for (IP_ADAPTER_UNICAST_ADDRESS* address = networkInterface->FirstUnicastAddress;
+             NULL != address; address = address->Next)
+        {
+          auto family = address->Address.lpSockaddr->sa_family;
+          if (AF_INET6 == family
+              && IpInterfaceNames.find(networkInterface->AdapterName)
+                   != IpInterfaceNames.end())
           {
-            SOCKADDR_IN6* addr6 =
+            SOCKADDR_IN6* sockAddr =
               reinterpret_cast<SOCKADDR_IN6*>(address->Address.lpSockaddr);
-            auto bytes = reinterpret_cast<const char*>(&addr6->sin6_addr);
-            addrs.emplace_back(discovery::makeAddress<discovery::IpAddressV6>(bytes));
+            auto bytes = reinterpret_cast<const char*>(&sockAddr->sin6_addr);
+            auto addr6 = discovery::makeAddress<discovery::IpAddressV6>(bytes);
+            if (!addr6.is_loopback() && addr6.is_link_local())
+            {
+              addrs.emplace_back(addr6);
+            }
           }
         }
       }
     });
+
     return addrs;
   }
 };