Merge branch 'route-poker-bugfix-duplicate-removals' into dev

llarp/constants/platform.hpp

@@ -94,7 +94,20 @@ namespace llarp::platform
   /// are we a mobile phone ?
   inline constexpr bool is_mobile = is_android or is_iphone;
 
-  /// does this platform support native ipv6 ?
-  // TODO: make windows support ipv6
-  inline constexpr bool supports_ipv6 = not is_windows;
+  /// every platform is a special snowflake.
+  /// we document every single workaround for their excentricities here.
+  namespace quarks
+  {
+
+    /// this is set to true on all platforms were we cannot enable a route when we have duplicate
+    /// gateways
+    inline constexpr bool duplicate_gateways_routes_fail = llarp::platform::is_windows;
+
+    /// set to true on platforms we cannot do os level ipv6 with tunneling.
+    inline constexpr bool disable_ipv6 = is_windows or is_android;
+
+  }  // namespace quarks
+
+  /// compat value, lokinet is ipv6 inside.
+  inline constexpr bool supports_ipv6 = not quarks::disable_ipv6;
 }  // namespace llarp::platform

llarp/router/route_poker.cpp

@@ -4,6 +4,7 @@
 #include <llarp/service/context.hpp>
 #include <llarp/dns/platform.hpp>
 #include <unordered_set>
+#include <llarp/constants/platform.hpp>
 
 namespace llarp
 {
@@ -12,23 +13,12 @@ namespace llarp
   void
   RoutePoker::AddRoute(net::ipv4addr_t ip)
   {
-    if (not m_up)
-      return;
-    bool has_existing = m_PokedRoutes.count(ip);
-    // set up route and apply as needed
-    auto& gw = m_PokedRoutes[ip];
-    if (m_CurrentGateway)
-    {
-      // remove existing mapping as needed
-      if (has_existing)
-        DisableRoute(ip, gw);
-      // update and add new mapping
-      gw = *m_CurrentGateway;
-      log::info(logcat, "add route {} via {}", ip, gw);
-      EnableRoute(ip, gw);
-    }
-    else
-      gw = net::ipv4addr_t{};
+    auto [itr, inserted] =
+        m_PokedRoutes.try_emplace(ip, m_CurrentGateway.value_or(net::ipv4addr_t{}), 0);
+    if (inserted)
+      EnableRoute(itr->first, std::get<0>(itr->second));
+
+    std::get<1>(itr->second) += 1;
   }
 
   void
@@ -36,6 +26,7 @@ namespace llarp
   {
     if (ip.n and gateway.n and IsEnabled())
     {
+      log::info(logcat, "delete route {} via {}", ip, gateway);
       vpn::IRouteManager& route = m_Router->GetVPNPlatform()->RouteManager();
       route.DelRoute(ip, gateway);
     }
@@ -46,6 +37,7 @@ namespace llarp
   {
     if (ip.n and gateway.n and IsEnabled())
     {
+      log::info(logcat, "add route {} via {}", ip, gateway);
       vpn::IRouteManager& route = m_Router->GetVPNPlatform()->RouteManager();
       route.AddRoute(ip, gateway);
     }
@@ -54,11 +46,19 @@ namespace llarp
   void
   RoutePoker::DelRoute(net::ipv4addr_t ip)
   {
-    const auto itr = m_PokedRoutes.find(ip);
+    auto itr = m_PokedRoutes.find(ip);
     if (itr == m_PokedRoutes.end())
       return;
-    log::info(logcat, "del route {} via {}", itr->first, itr->second);
-    DisableRoute(itr->first, itr->second);
+
+    auto& [gw, refs] = itr->second;
+
+    // decrement reference count and then early return if we have uses still.
+    --refs;
+    if (refs)
+      return;
+
+    // unamp route if we have no uses of it left.
+    DisableRoute(ip, gw);
     m_PokedRoutes.erase(itr);
   }
 
@@ -76,27 +76,34 @@ namespace llarp
   }
 
   void
-  RoutePoker::DeleteAllRoutes()
+  RoutePoker::RefreshAllRoutes()
   {
-    // DelRoute will check enabled, so no need here
-    for (const auto& item : m_PokedRoutes)
-      DelRoute(item.first);
-  }
+    if (not m_CurrentGateway)
+      return;
 
-  void
-  RoutePoker::DisableAllRoutes()
-  {
-    for (const auto& [ip, gateway] : m_PokedRoutes)
+    const auto& current_gw = *m_CurrentGateway;
+
+    for (auto& [ip, entry] : m_PokedRoutes)
     {
-      DisableRoute(ip, gateway);
-    }
-  }
+      auto& gw = std::get<0>(entry);
+      if (gw != current_gw)
+      {
+        if constexpr (not llarp::platform::quarks::duplicate_gateways_routes_fail)
+        {
+          // normal behavior
+          EnableRoute(ip, current_gw);
+          DisableRoute(ip, gw);
+        }
+        else
+        {
+          // reverse order because platform quark
+          DisableRoute(ip, gw);
+          EnableRoute(ip, current_gw);
+        }
 
-  void
-  RoutePoker::RefreshAllRoutes()
-  {
-    for (const auto& item : m_PokedRoutes)
-      AddRoute(item.first);
+        gw = current_gw;
+      }
+    }
   }
 
   RoutePoker::~RoutePoker()
@@ -105,10 +112,12 @@ namespace llarp
       return;
 
     auto& route = m_Router->GetVPNPlatform()->RouteManager();
-    for (const auto& [ip, gateway] : m_PokedRoutes)
+    for (const auto& [ip, entry] : m_PokedRoutes)
     {
-      if (gateway.n and ip.n)
-        route.DelRoute(ip, gateway);
+      const auto& gw = std::get<0>(entry);
+
+      if (gw.n and ip.n)
+        route.DelRoute(ip, gw);
     }
     route.DelBlackhole();
   }
@@ -179,9 +188,11 @@ namespace llarp
       {
         log::info(logcat, "default gateway found at {}", *next_gw);
         m_CurrentGateway = next_gw;
+        if (not m_PokedRoutes.empty())
+          RefreshAllRoutes();
       }
     }
-    else if (m_Router->HasClientExit())
+    if (m_Router->HasClientExit())
       Up();
   }
 

llarp/router/route_poker.hpp

@@ -12,9 +12,16 @@ namespace llarp
 
   struct RoutePoker : public std::enable_shared_from_this<RoutePoker>
   {
+    /// add a route exception to an edge by ip
+    /// if we have a default gateway and our routes are set to be "up" we will enable this route.
+    /// if there is an existing entry for this ip, we increment a reference counter and keep the
+    /// route previously added in.
     void
     AddRoute(net::ipv4addr_t ip);
 
+    /// remove a route exception to an edge by ip.
+    /// decrements the number of edges that use this ip. when the reference counter hits zero and we
+    /// are "up" we unmap the route.
     void
     DelRoute(net::ipv4addr_t ip);
 
@@ -43,12 +50,6 @@ namespace llarp
     bool
     IsEnabled() const;
 
-    void
-    DeleteAllRoutes();
-
-    void
-    DisableAllRoutes();
-
     void
     RefreshAllRoutes();
 
@@ -58,7 +59,7 @@ namespace llarp
     void
     DisableRoute(net::ipv4addr_t ip, net::ipv4addr_t gateway);
 
-    std::unordered_map<net::ipv4addr_t, net::ipv4addr_t> m_PokedRoutes;
+    std::unordered_map<net::ipv4addr_t, std::tuple<net::ipv4addr_t, int>> m_PokedRoutes;
 
     std::optional<net::ipv4addr_t> m_CurrentGateway;