feat(lb): user netdev ip as lb server fixed id

emqx · Sep 19, 2024 · 942356f · 942356f
1 parent 6766470
commit 942356f
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Showing 3 changed files with 56 additions and 5 deletions.
diff --git a/c_src/quicer_nif.c b/c_src/quicer_nif.c
@@ -1186,10 +1186,29 @@ openLib(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
           env, argv[0], ATOM_QUIC_PARAM_GLOBAL_LOAD_BALACING_MODE, &eterm)
       && enif_get_uint(env, eterm, &lb_mode))
     {
-      MsQuic->SetParam(NULL,
-                       QUIC_PARAM_GLOBAL_LOAD_BALACING_MODE,
-                       sizeof(uint16_t),
-                       (uint16_t *)&lb_mode);
+
+      if (lb_mode > QUIC_LOAD_BALANCING_COUNT)
+        {
+          // quicer specific load balancing settings
+          // use FixedServerID
+          QUIC_GLOBAL_SETTINGS global_settings;
+          global_settings.IsSet.LoadBalancingMode = TRUE;
+          global_settings.IsSet.FixedServerID = TRUE;
+          global_settings.LoadBalancingMode
+              = QUIC_LOAD_BALANCING_SERVER_ID_FIXED;
+          global_settings.FixedServerID = lb_mode;
+          MsQuic->SetParam(NULL,
+                           QUIC_PARAM_GLOBAL_GLOBAL_SETTINGS,
+                           sizeof(global_settings),
+                           &global_settings);
+        }
+      else
+        {
+          MsQuic->SetParam(NULL,
+                           QUIC_PARAM_GLOBAL_LOAD_BALACING_MODE,
+                           sizeof(uint16_t),
+                           (uint16_t *)&lb_mode);
+        }
     }
 
   if (enif_get_map_value(env, argv[0], ATOM_TRACE, &eterm)

diff --git a/include/quicer.hrl b/include/quicer.hrl
@@ -17,6 +17,8 @@
 -ifndef(QUICER_HRL).
 -define(QUICER_HRL, true).
 
+-define(DEFAULT_LB_DEV, "eth0").
+
 %%% ========================================
 %%% mirror macro from NIF code
 %%% ========================================
@@ -140,4 +142,10 @@
     bin :: binary()
 }).
 
+-define(QUIC_LOAD_BALANCING_DISABLED, 0).
+-define(QUIC_LOAD_BALANCING_SERVER_ID_IP, 1).
+-define(QUIC_LOAD_BALANCING_SERVER_ID_FIXED, 2).
+-define(QUIC_LOAD_BALANCING_COUNT, 3).
+-define(QUICER_LOAD_BALANCING_IFIP_AS_SERVER_ID, 100). %% User Network Interface IP as Server ID
+
 -endif. %% QUICER_HRL
diff --git a/src/quicer_nif.erl b/src/quicer_nif.erl
@@ -156,8 +156,15 @@ open_lib() ->
             {error, _} ->
                 priv_dir()
         end,
+    LBMode =
+        case application:get_env(quicer, lb_mode, 0) of
+            ?QUICER_LOAD_BALANCING_IFIP_AS_SERVER_ID ->
+                lb_server_id(ipv4, application:get_env(quicer, lb_dev, ?DEFAULT_LB_DEV));
+            X ->
+                X
+        end,
     open_lib(#{
-        load_balacing_mode => application:get_env(quicer, lb_mode, 0),
+        load_balacing_mode => LBMode,
         trace => LibFile
     }).
 
@@ -424,3 +431,20 @@ priv_dir() ->
         Dir ->
             Dir
     end.
+
+%% @doc Get the load balancing server id from the given device name. ipv4 only.
+-spec lb_server_id(ipv4, string()) -> non_neg_integer().
+lb_server_id(ipv4, DevName) ->
+    try
+        {ok, IfList} = inet:getifaddrs(),
+        %% @NOTE Be aware of the order of the bytes in the address
+        lists:foldr(
+            fun(I, V) -> V bsl 8 bor I end,
+            0,
+            tuple_to_list(proplists:get_value(addr, proplists:get_value(DevName, IfList)))
+        )
+    catch
+        _:E ->
+            logger:error("Failed to set lb mode from ~s, fallback to disabled: ~p", [DevName, E]),
+            ?QUIC_LOAD_BALANCING_DISABLED
+    end.