From: Michael Prokop <mika@grml.org>
Date: Wed, 17 Aug 2022 12:05:25 +0000 (+0200)
Subject: netcardconfig: avoid suggesting default gateway if a default route exists already
X-Git-Tag: v0.14.0~1
X-Git-Url: http://git.grml.org/?p=grml-network.git;a=commitdiff_plain;h=5681e2bcbd6864dfba753aa4a9f240d30ac085b6

netcardconfig: avoid suggesting default gateway if a default route exists already

When multiple NICs are present, a default gateway might exist already,
while adding another default gateway then fails and is confusing.
So instead let's present an empty input text dialog then, so the
defaults should work fine.

See https://github.com/grml/grml-terminalserver/issues/4
---

diff --git a/sbin/netcardconfig b/sbin/netcardconfig
index 8916642..4a3cd71 100755
--- a/sbin/netcardconfig
+++ b/sbin/netcardconfig
@@ -410,7 +410,12 @@ configiface() {
       $DIALOG --inputbox "$MESSAGE8 $DV" 10 45 "${BC:-${IP%.*}.255}" 2>"$TMP" || bailout 1
       read -r BC <"$TMP" ; rm -f "$TMP"
 
-      $DIALOG --inputbox "$MESSAGE9" 10 45 "${DG:-${IP%.*}.1}" 2>"$TMP"
+      # if we already have a default route, don't suggest to add another one as that might fail
+      __default_gw=""
+      if ! route -en | grep -q '^0.0.0.0' ; then
+        __default_gw="${DG:-${IP%.*}.1}"
+      fi
+      $DIALOG --inputbox "$MESSAGE9" 10 45 "${__default_gw}" 2>"$TMP"
       read -r DG <"$TMP" ; rm -f "$TMP"
 
       if [ -f "/etc/resolv.conf" ]; then