From 8c535a0198c132928fb87e1cf949adaeb5fcc60c Mon Sep 17 00:00:00 2001
From: Paul Kulchenko <paul@kulchenko.com>
Date: Sun, 31 Oct 2021 17:10:43 -0700
Subject: [PATCH] Add redbean Lua IsLoopbackClient function

---
 tool/net/help.txt  | 4 ++++
 tool/net/redbean.c | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/tool/net/help.txt b/tool/net/help.txt
index 3bc82887b..9c21645e6 100644
--- a/tool/net/help.txt
+++ b/tool/net/help.txt
@@ -761,6 +761,10 @@ FUNCTIONS
            Returns true if IP address is part of a private network
            (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16).
 
+   IsLoopbackClient() → bool
+           Returns true if the client IP address (returned by GetRemoteAddr)
+           is part of the localhost network (127.0.0.0/8).
+
    IsLoopbackIp(uint32) → bool
            Returns true if IP address is part of the localhost network
            (127.0.0.0/8).
diff --git a/tool/net/redbean.c b/tool/net/redbean.c
index 583e54f7a..54dd1269b 100644
--- a/tool/net/redbean.c
+++ b/tool/net/redbean.c
@@ -3980,6 +3980,12 @@ static int LuaIsLoopbackIp(lua_State *L) {
   return LuaIsIp(L, IsLoopbackIp);
 }
 
+static int LuaIsLoopbackClient(lua_State *L) {
+  OnlyCallDuringRequest(L, "IsLoopbackClient");
+  lua_pushboolean(L, IsLoopbackClient());
+  return 1;
+}
+
 static int LuaCategorizeIp(lua_State *L) {
   lua_pushstring(L, GetIpCategoryName(CategorizeIp(luaL_checkinteger(L, 1))));
   return 1;
@@ -5369,6 +5375,7 @@ static const luaL_Reg kLuaFuncs[] = {
     {"IsCompressed", LuaIsCompressed},                          //
     {"IsDaemon", LuaIsDaemon},                                  //
     {"IsHiddenPath", LuaIsHiddenPath},                          //
+    {"IsLoopbackClient", LuaIsLoopbackClient},                  //
     {"IsLoopbackIp", LuaIsLoopbackIp},                          //
     {"IsPrivateIp", LuaIsPrivateIp},                            //
     {"IsPublicIp", LuaIsPublicIp},                              //