From b6a8048c8bb2e9fdb46dd688173ac1c71f3924a0 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Wed, 6 Apr 2022 22:26:37 +0000
Subject: [PATCH] uplink: use route with lowest metric

---
 blinkenlicht/netlink.nix | 8 +++++++-
 blinkenlicht/uplink.fnl  | 6 +++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/blinkenlicht/netlink.nix b/blinkenlicht/netlink.nix
index b1ae4fb..2855cae 100644
--- a/blinkenlicht/netlink.nix
+++ b/blinkenlicht/netlink.nix
@@ -1,4 +1,4 @@
-{ lua, lib,  fetchFromGitHub, buildLuaPackage, libmnl }:
+{ lua, lib, fetchpatch, fetchFromGitHub, buildLuaPackage, libmnl }:
 let pname = "netlink";
 in buildLuaPackage {
   inherit pname;
@@ -12,6 +12,12 @@ in buildLuaPackage {
     rev = "v0.1.1";
     hash = "sha256:1833naskl4p7rz5kk0byfgngvw1mvf6cnz64sr3ny7i202wv7s52";
   };
+  patches = [ (fetchpatch {
+    url = "https://github.com/chris2511/lua-netlink/compare/master...telent:rtnetlink-types.patch";
+    name = "rtnetlink-types.patch";
+    hash = "sha256-lBCfP8pMyBIY+XEGWD/nPQ9l2dDOnXeitR1TaRUXCq8=";
+  })];
+
   buildPhase = "$CC -shared -l mnl -o netlink.so src/*.c";
 
   installPhase = ''
diff --git a/blinkenlicht/uplink.fnl b/blinkenlicht/uplink.fnl
index b0f6ffa..deb2a7e 100644
--- a/blinkenlicht/uplink.fnl
+++ b/blinkenlicht/uplink.fnl
@@ -75,7 +75,11 @@
         ;; (e.g wwan and wlan both have default route)
         ;; we probably need to store all of them and
         ;; distinguish by metric
-        (tset routes (or event.dst "default") event)
+        (let [dst (or event.dst "default")
+              existing (. routes dst)]
+          (if (or (not existing)
+                  (< event.metric existing.metric))
+              (tset routes dst event)))
 
         {} (print :unhandled event.event)
         ))