From 63e3961e1c2692d974f15ac51f32f0aeed187617 Mon Sep 17 00:00:00 2001
From: Paul Guyot <pguyot@kallisys.net>
Date: Sat, 14 Dec 2024 15:10:09 +0100
Subject: [PATCH] Add `inet:getaddr/2`

Signed-off-by: Paul Guyot <pguyot@kallisys.net>
---
 CHANGELOG.md                      |  1 +
 libs/estdlib/src/inet.erl         | 33 +++++++++++++++++++++++++--
 tests/libs/estdlib/CMakeLists.txt |  1 +
 tests/libs/estdlib/test_inet.erl  | 38 +++++++++++++++++++++++++++++++
 tests/libs/estdlib/tests.erl      |  1 +
 5 files changed, 72 insertions(+), 2 deletions(-)
 create mode 100644 tests/libs/estdlib/test_inet.erl

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a55020586..ec553b896 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added a limited implementation of the OTP `ets` interface
 - Added `code:all_loaded/0` and `code:all_available/0`
 - Added `erlang:split_binary/2`
+- Added `inet:getaddr/2`
 
 ## [0.6.6] - Unreleased
 
diff --git a/libs/estdlib/src/inet.erl b/libs/estdlib/src/inet.erl
index 6af6c9a60..8eb3b2b61 100644
--- a/libs/estdlib/src/inet.erl
+++ b/libs/estdlib/src/inet.erl
@@ -20,7 +20,7 @@
 
 -module(inet).
 
--export([port/1, close/1, sockname/1, peername/1]).
+-export([port/1, close/1, sockname/1, peername/1, getaddr/2]).
 
 -include("inet-priv.hrl").
 
@@ -30,7 +30,8 @@
 -type port_number() :: 0..65535.
 -type ip_address() :: ip4_address().
 -type ip4_address() :: {0..255, 0..255, 0..255, 0..255}.
--type hostname() :: iodata().
+-type hostname() :: atom() | string().
+-type address_family() :: inet.
 
 -export_type([socket/0, port_number/0, ip_address/0, ip4_address/0, hostname/0]).
 
@@ -85,3 +86,31 @@ sockname({Moniker, Socket, Module}) when
     {ok, {ip_address(), port_number()}} | {error, Reason :: term()}.
 peername({?GEN_TCP_MONIKER, Socket, Module}) ->
     Module:peername(Socket).
+
+%%-----------------------------------------------------------------------------
+%% @param   Name the name to resolve
+%% @param   Family the family to resolve it to
+%% @returns The address or an error tuple.
+%% @doc     Get the IP address associated with a given name.
+%% @end
+%%-----------------------------------------------------------------------------
+-spec getaddr(Name :: ip_address() | hostname(), Family :: address_family()) ->
+    {ok, ip_address()} | {error, Reason :: term()}.
+getaddr(Name, _Family) when is_tuple(Name) ->
+    {ok, Name};
+getaddr(Name, Family) when is_atom(Name) ->
+    getaddr(atom_to_list(Name), Family);
+getaddr(Name, Family) ->
+    try net:getaddrinfo(Name) of
+        {ok, Results} ->
+            Filtered = [Addr || #{family := F, addr := #{addr := Addr}} <- Results, F =:= Family],
+            case Filtered of
+                [] -> {error, nxdomain};
+                [IPAddr | _] -> {ok, IPAddr}
+            end;
+        {error, _} = Err ->
+            Err
+    catch
+        error:function_clause ->
+            {error, einval}
+    end.
diff --git a/tests/libs/estdlib/CMakeLists.txt b/tests/libs/estdlib/CMakeLists.txt
index ebc4754f4..3e63834b6 100644
--- a/tests/libs/estdlib/CMakeLists.txt
+++ b/tests/libs/estdlib/CMakeLists.txt
@@ -31,6 +31,7 @@ set(ERLANG_MODULES
     test_gen_statem
     test_gen_udp
     test_gen_tcp
+    test_inet
     test_io_lib
     test_lists
     test_logger
diff --git a/tests/libs/estdlib/test_inet.erl b/tests/libs/estdlib/test_inet.erl
new file mode 100644
index 000000000..6703aaa35
--- /dev/null
+++ b/tests/libs/estdlib/test_inet.erl
@@ -0,0 +1,38 @@
+%
+% This file is part of AtomVM.
+%
+% Copyright 2024 Paul Guyot <pguyot@kallisys.net>
+%
+% Licensed under the Apache License, Version 2.0 (the "License");
+% you may not use this file except in compliance with the License.
+% You may obtain a copy of the License at
+%
+%    http://www.apache.org/licenses/LICENSE-2.0
+%
+% Unless required by applicable law or agreed to in writing, software
+% distributed under the License is distributed on an "AS IS" BASIS,
+% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+% See the License for the specific language governing permissions and
+% limitations under the License.
+%
+% SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later
+%
+
+-module(test_inet).
+
+-export([test/0]).
+
+test() ->
+    ok = test_getaddr(),
+    ok.
+
+test_getaddr() ->
+    {ok, {127, 0, 0, 1}} = inet:getaddr(localhost, inet),
+    {ok, {127, 0, 0, 1}} = inet:getaddr("localhost", inet),
+    {ok, {_, _, _, _}} = inet:getaddr("www.atomvm.net", inet),
+    % RFC8880
+    {ok, {192, 0, 0, LastByte}} = inet:getaddr("ipv4only.arpa", inet),
+    true = LastByte =:= 170 orelse LastByte =:= 171,
+    {error, einval} = inet:getaddr(<<"localhost">>, inet),
+    {error, _} = inet:getaddr("localhost.invalid", inet),
+    ok.
diff --git a/tests/libs/estdlib/tests.erl b/tests/libs/estdlib/tests.erl
index 21de828b8..ae70db2fd 100644
--- a/tests/libs/estdlib/tests.erl
+++ b/tests/libs/estdlib/tests.erl
@@ -52,6 +52,7 @@ get_tests(_OTPVersion) ->
         test_gen_statem,
         test_gen_udp,
         test_gen_tcp,
+        test_inet,
         test_io_lib,
         test_logger,
         test_maps,