From b6e95c425ea85de587c6c95592652f7ee3a32b7f Mon Sep 17 00:00:00 2001
From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Mon, 22 Nov 2021 12:05:30 +0100
Subject: [PATCH] dnsdist: Add Lua bindings to get the list of network
 interfaces, addresses

---
 pdns/dnsdist-console.cc                    |  2 ++
 pdns/dnsdist-lua-bindings.cc               | 20 ++++++++++++++++++++
 pdns/dnsdistdist/docs/reference/config.rst | 16 ++++++++++++++++
 3 files changed, 38 insertions(+)

diff --git a/pdns/dnsdist-console.cc b/pdns/dnsdist-console.cc
index a052779e38..09be3c0132 100644
--- a/pdns/dnsdist-console.cc
+++ b/pdns/dnsdist-console.cc
@@ -457,6 +457,8 @@ const std::vector<ConsoleKeyword> g_consoleKeywords{
   { "getDNSCryptBindCount", true, "", "returns the number of DNSCrypt listeners" },
   { "getDOHFrontend", true, "n", "returns the DOH frontend with index n" },
   { "getDOHFrontendCount", true, "", "returns the number of DoH listeners" },
+  { "getListOfAddressesOfNetworkInterface", true, "itf", "returns the list of addresses configured on a given network interface, as strings" },
+  { "getListOfNetworkInterfaces", true, "", "returns the list of network interfaces present on the system, as strings" },
   { "getOutgoingTLSSessionCacheSize", true, "", "returns the number of TLS sessions (for outgoing connections) currently cached" },
   { "getPool", true, "name", "return the pool named `name`, or \"\" for the default pool" },
   { "getPoolServers", true, "pool", "return servers part of this pool" },
diff --git a/pdns/dnsdist-lua-bindings.cc b/pdns/dnsdist-lua-bindings.cc
index ae44c7b631..5e51e19264 100644
--- a/pdns/dnsdist-lua-bindings.cc
+++ b/pdns/dnsdist-lua-bindings.cc
@@ -616,4 +616,24 @@ void setupLuaBindings(LuaContext& luaCtx, bool client)
 
     return parameters;
   });
+
+  luaCtx.writeFunction("getListOfNetworkInterfaces", []() {
+    std::vector<std::pair<int, std::string>> result;
+    auto itfs = getListOfNetworkInterfaces();
+    int counter = 1;
+    for (const auto& itf : itfs) {
+      result.push_back({counter++, itf});
+    }
+    return result;
+  });
+
+  luaCtx.writeFunction("getListOfAddressesOfNetworkInterface", [](const std::string& itf) {
+    std::vector<std::pair<int, std::string>> result;
+    auto addrs = getListOfAddressesOfNetworkInterface(itf);
+    int counter = 1;
+    for (const auto& addr : addrs) {
+      result.push_back({counter++, addr.toString()});
+    }
+    return result;
+  });
 }
diff --git a/pdns/dnsdistdist/docs/reference/config.rst b/pdns/dnsdistdist/docs/reference/config.rst
index 5b5cc0cf83..e0b6db8f72 100644
--- a/pdns/dnsdistdist/docs/reference/config.rst
+++ b/pdns/dnsdistdist/docs/reference/config.rst
@@ -950,6 +950,22 @@ Status, Statistics and More
 
   Return the number of DOHFrontend binds.
 
+.. function:: getListOfAddressesOfNetworkInterface(itf)
+
+  .. versionadded:: 1.8.0
+
+  Return the list of addresses configured on a given network interface, as strings.
+  This function requires support for ``getifaddrs``, which is known to be present on FreeBSD, Linux, and OpenBSD at least.
+
+  :param str itf: The name of the network interface
+
+.. function:: getListOfNetworkInterfaces()
+
+  .. versionadded:: 1.8.0
+
+  Return the list of network interfaces configured on the system, as strings
+  This function requires support for ``getifaddrs``, which is known to be present on FreeBSD, Linux, and OpenBSD at least.
+
 .. function:: getOutgoingTLSSessionCacheSize()
 
   .. versionadded:: 1.7.0
-- 
2.47.2