From 30b68611f765c45f1e22ab0f60c00803bc964eb4 Mon Sep 17 00:00:00 2001
From: Coiby Xu <coxu@redhat.com>
Date: Tue, 8 Aug 2023 14:44:52 +0800
Subject: [PATCH] Add NICs that handle DNS queries to the allowlist

Resolves: bz2229287
Upstream: RHEL-ONLY
Conflict: None

There is a use case where a separate NIC is used to handle DNS queries.
In this case this NIC should be added to the allowlist as well.

Fixes: e67e4bd ("Reduce kdump memory consumption by only installing needed NIC drivers")
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 dracut-module-setup.sh | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index 0cf35a8..1fa3011 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -108,6 +108,17 @@ source_ifcfg_file() {
     fi
 }
 
+add_dns_netdev() {
+    local _server _route
+
+    _server=$1
+    _route=`/sbin/ip -o route get to $_server 2>&1`
+    [ $? != 0 ] && echo "DNS server $_server unreachable"
+
+    _netdev=$(get_ip_route_field "$_route" "dev")
+    _save_kdump_netifs "$_netdev" "$(kdump_setup_ifname $_netdev)"
+}
+
 # $1: netdev name
 kdump_setup_dns() {
     local _nameserver _dns
@@ -115,8 +126,8 @@ kdump_setup_dns() {
 
     source_ifcfg_file $1
 
-    [ -n "$DNS1" ] && echo "nameserver=$DNS1" > "$_dnsfile"
-    [ -n "$DNS2" ] && echo "nameserver=$DNS2" >> "$_dnsfile"
+    [ -n "$DNS1" ] && echo "nameserver=$DNS1" > "$_dnsfile" && add_dns_netdev "$DNS1"
+    [ -n "$DNS2" ] && echo "nameserver=$DNS2" >> "$_dnsfile" && add_dns_netdev "$DNS2"
 
     while read content;
     do
@@ -128,6 +139,7 @@ kdump_setup_dns() {
 
         if [ ! -f $_dnsfile ] || [ ! $(cat $_dnsfile | grep -q $_dns) ]; then
             echo "nameserver=$_dns" >> "$_dnsfile"
+            add_dns_netdev "$_dns"
         fi
     done < "/etc/resolv.conf"
 }