Fixing IPv6 address parse + IPv6 host name resolution + inet family :inet or :inet6 based on peer's socket address to the client's socket

Author: Tomasz Kazimierz Motyl

src/eradius_client.erl

@@ -1,4 +1,4 @@
-%% @doc This module contains a RADIUS client that can be used to send authentication and accounting requests.
+  %% @doc This module contains a RADIUS client that can be used to send authentication and accounting requests.
 %%   A counter is kept for every NAS in order to determine the next request id and sender port
 %%   for each outgoing request. The implementation naively assumes that you won't send requests to a
 %%   distinct number of NASs over the lifetime of the VM, which is why the counters are not garbage-collected.
@@ -36,8 +36,8 @@
                         Req#radius_request.cmd == 'coareq' orelse
                         Req#radius_request.cmd == 'discreq')).
 
--type nas_address() :: {string() | binary() | inet:ip_address(), 
-                        eradius_server:port_number(), 
+-type nas_address() :: {string() | binary() | inet:ip_address(),
+                        eradius_server:port_number(),
                         eradius_lib:secret()}.
 -type options() :: [{retries, pos_integer()} |
                     {timeout, timeout()} |
@@ -63,10 +63,10 @@ send_request(NAS, Request) ->
 %   If no answer is received within the specified timeout, the request will be sent again.
 -spec send_request(nas_address(), #radius_request{}, options()) ->
     {ok, binary(), eradius_lib:authenticator()} | {error, 'timeout' | 'socket_down'}.
-send_request({Host, Port, Secret}, Request, Options) 
+send_request({Host, Port, Secret}, Request, Options)
   when ?GOOD_CMD(Request) andalso is_binary(Host) ->
     send_request({erlang:binary_to_list(Host), Port, Secret}, Request, Options);
-send_request({Host, Port, Secret}, Request, Options) 
+send_request({Host, Port, Secret}, Request, Options)
   when ?GOOD_CMD(Request) andalso is_list(Host) ->
     IP = get_ip(Host),
     send_request({IP, Port, Secret}, Request, Options);
@@ -335,10 +335,19 @@ init([]) ->
         Else            -> Else
     end.
 
+%% @private
+inet_family_based_on_peer(_PeerSocket = {{_, _, _, _}, _port}) ->
+    [inet];
+inet_family_based_on_peer(_PeerSocket = {{_, _, _, _, _, _, _, _}, _port}) ->
+    [inet6];
+inet_family_based_on_peer(_PeerSocket) ->
+    [].
+
 %% @private
 handle_call({wanna_send, Peer = {_PeerName, PeerSocket}, _MetricsInfo}, _From, State) ->
     {PortIdx, ReqId, NewIdCounters} = next_port_and_req_id(PeerSocket, State#state.no_ports, State#state.idcounters),
-    {SocketProcess, NewSockets} = find_socket_process(PortIdx, State#state.sockets, State#state.socket_ip, State#state.sup),
+    InetFamily = inet_family_based_on_peer(PeerSocket),
+    {SocketProcess, NewSockets} = find_socket_process(PortIdx, State#state.sockets, State#state.socket_ip, InetFamily, State#state.sup),
     IsCreated = lists:member(Peer, State#state.clients),
     NewState = case IsCreated of
                    false ->
@@ -512,11 +521,11 @@ next_port_and_req_id(Peer, NumberOfPorts, Counters) ->
     NewCounters = Counters#{Peer => {NextPortIdx, NextReqId}},
     {NextPortIdx, NextReqId, NewCounters}.
 
-find_socket_process(PortIdx, Sockets, SocketIP, Sup) ->
+find_socket_process(PortIdx, Sockets, SocketIP, Options, Sup) ->
     case array:get(PortIdx, Sockets) of
         undefined ->
             Res = supervisor:start_child(Sup, {PortIdx,
-                {eradius_client_socket, start, [SocketIP, self(), PortIdx]},
+                {eradius_client_socket, start, [SocketIP, self(), PortIdx, Options]},
                 transient, brutal_kill, worker, [eradius_client_socket]}),
             Pid = case Res of
                 {ok, P} -> P;
@@ -538,7 +547,7 @@ parse_ip(Address) when is_list(Address) ->
     inet_parse:address(Address);
 parse_ip(T = {_, _, _, _}) ->
     {ok, T};
-parse_ip(T = {_, _, _, _, _, _}) ->
+parse_ip(T = {_, _, _, _, _, _, _, _}) ->
     {ok, T}.
 
 init_server_status_metrics() ->
@@ -689,5 +698,15 @@ get_ip(Host) ->
         {ok, #hostent{h_addrtype = inet, h_addr_list = [_ | _] = IPs}} ->
             Index = rand:uniform(length(IPs)),
             lists:nth(Index, IPs);
-        _ -> error(badarg)
+        _ ->
+          case inet:gethostbyname(Host, inet6) of
+              {ok, #hostent{h_addrtype = inet6, h_addr_list = [IP]}} ->
+                  send_request({IP, Port, Secret}, Request, Options);
+              {ok, #hostent{h_addrtype = inet6, h_addr_list = [_ | _] = IPs}} ->
+                  Index = rand:uniform(length(IPs)),
+                  IP = lists:nth(Index, IPs),
+                  send_request({IP, Port, Secret}, Request, Options);
+              _Err ->
+                  error(badarg)
+          end
     end.

src/eradius_client_socket.erl

@@ -2,22 +2,23 @@
 
 -behaviour(gen_server).
 
--export([start/3]).
+-export([start/4]).
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
 
 -record(state, {client, socket, pending, mode, counter}).
 
-start(SocketIP, Client, PortIdx) ->
-    gen_server:start_link(?MODULE, [SocketIP, Client, PortIdx], []).
+start(SocketIP, Client, PortIdx, Options) ->
+    gen_server:start_link(?MODULE, [SocketIP, Client, PortIdx, Options], []).
 
-init([SocketIP, Client, PortIdx]) ->
+init([SocketIP, Client, PortIdx, Options]) ->
     Client ! {PortIdx, self()},
-    case SocketIP of
-        undefined ->
-            ExtraOptions = [];
-        SocketIP when is_tuple(SocketIP) ->
-            ExtraOptions = [{ip, SocketIP}]
-    end,
+    ExtraOptions =
+        case SocketIP of
+            undefined ->
+                Options;
+            SocketIP when is_tuple(SocketIP) ->
+                [{ip, SocketIP} | Options]
+        end,
     RecBuf = application:get_env(eradius, recbuf, 8192),
     SndBuf = application:get_env(eradius, sndbuf, 131072),
     {ok, Socket} = gen_udp:open(0, [{active, once}, binary , {recbuf, RecBuf}, {sndbuf, SndBuf} | ExtraOptions]),

test/eradius_client_SUITE.erl

@@ -148,7 +148,7 @@ split2(N, List1, [L|List2]) -> split2(N-1, [L|List1], List2).
 
 meckStart() ->
     ok = meck:new(eradius_client_socket),
-    ok = meck:expect(eradius_client_socket, start, fun(X, Y, Z) -> eradius_client_socket_test:start(X, Y, Z) end),
+    ok = meck:expect(eradius_client_socket, start, fun(X, Y, Z, O) -> eradius_client_socket_test:start(X, Y, Z, O) end),
     ok = meck:expect(eradius_client_socket, init, fun(X) -> eradius_client_socket_test:init(X) end),
     ok = meck:expect(eradius_client_socket, handle_call, fun(X, Y, Z) -> eradius_client_socket_test:handle_call(X, Y, Z) end),
     ok = meck:expect(eradius_client_socket, handle_cast, fun(X, Y) -> eradius_client_socket_test:handle_cast(X, Y) end),
@@ -165,7 +165,7 @@ parse_ip(Address) when is_list(Address) ->
     inet_parse:address(Address);
 parse_ip(T = {_, _, _, _}) ->
     {ok, T};
-parse_ip(T = {_, _, _, _, _, _}) ->
+parse_ip(T = {_, _, _, _, _, _, _, _}) ->
     {ok, T}.
 
 %% CHECK

test/eradius_client_socket_test.erl

@@ -22,15 +22,15 @@
 
 -behaviour(gen_server).
 
--export([start/3]).
+-export([start/4]).
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
 
 -record(state, {client, socket, pending, mode, counter}).
 
-start(SocketIP, Client, PortIdx) ->
-    gen_server:start_link(?MODULE, [SocketIP, Client, PortIdx], []).
+start(SocketIP, Client, PortIdx, Options) ->
+    gen_server:start_link(?MODULE, [SocketIP, Client, PortIdx, Options], []).
 
-init([_SocketIP, Client, PortIdx]) ->
+init([_SocketIP, Client, PortIdx, Options]) ->
     Client ! {PortIdx, self()},
     eradius_client_SUITE:addSocket(),
     {ok, #state{pending = maps:new(), mode = active, counter = 0}}.