From 668875e1864a405091a8064f63db94ebc7c47983 Mon Sep 17 00:00:00 2001
From: Coiby Xu <coxu@redhat.com>
Date: Wed, 23 Nov 2022 09:42:18 +0800
Subject: [PATCH] Determine whether IPv4 or IPv6 is needed

Resolves: bz2076416
Upstream: Fedora
Conflict: None

commit 9dfcacf72d2cd135bf8b72c4bbc97f15efa21250
Author: Coiby Xu <coxu@redhat.com>
Date:   Thu Sep 8 17:06:19 2022 +0800

    Determine whether IPv4 or IPv6 is needed

    According to `man nm-online`,
      "By default, connections have the ipv4.may-fail and
      ipv6.may-fail properties set to yes; this means that
      NetworkManager waits for one of the two address families to
      complete configuration before considering the connection
      activated. If you need a specific address family configured
      before network-online.target is reached, set the corresponding
      may-fail property to no."

    If a NIC has an IPv4 or IPv6 address, set the corresponding may-fail
    property to no. Otherwise, dumping vmcore over IPv6 could fail because
    only IPv4 network is ready or vice versa.

    Also disable IPv6 if only IPv4 is used and vice versa.

    Signed-off-by: Coiby Xu <coxu@redhat.com>
    Reviewed-by: Thomas Haller <thaller@redhat.com>
    Reviewed-by: Philipp Rudo <prudo@redhat.com>

Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 dracut-module-setup.sh | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index e74a026..299e105 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -365,6 +365,24 @@ kdump_setup_ifname() {
     echo "$_ifname"
 }
 
+use_ipv4_or_ipv6() {
+    local _netif=$1 _uuid=$2
+
+    if [[ -v "ipv4_usage[$_netif]" ]]; then
+        nmcli connection modify --temporary "$_uuid" ipv4.may-fail no &> >(ddebug)
+    fi
+
+    if [[ -v "ipv6_usage[$_netif]" ]]; then
+        nmcli connection modify --temporary "$_uuid" ipv6.may-fail no &> >(ddebug)
+    fi
+
+    if [[ -v "ipv4_usage[$_netif]" ]] && [[ ! -v "ipv6_usage[$_netif]" ]]; then
+        nmcli connection modify --temporary "$_uuid" ipv6.method disabled &> >(ddebug)
+    elif [[ ! -v "ipv4_usage[$_netif]" ]] && [[ -v "ipv6_usage[$_netif]" ]]; then
+        nmcli connection modify --temporary "$_uuid" ipv4.method disabled &> >(ddebug)
+    fi
+}
+
 _clone_nmconnection() {
     local _clone_output _name _unique_id
 
@@ -396,6 +414,8 @@ clone_and_modify_nmconnection() {
         exit 1
     fi
 
+    use_ipv4_or_ipv6 "$_dev" "$_uuid"
+
     _cloned_nmconnection_file_path=$(nmcli --get-values UUID,FILENAME connection show | sed -n "s/^${_uuid}://p")
     _tmp_nmconnection_file_path=$_DRACUT_KDUMP_NM_TMP_DIR/$(basename "$_nmconnection_file_path")
     cp "$_cloned_nmconnection_file_path" "$_tmp_nmconnection_file_path"
@@ -1104,7 +1124,7 @@ remove_cpu_online_rule() {
 }
 
 install() {
-    declare -A unique_netifs
+    declare -A unique_netifs ipv4_usage ipv6_usage
     local arch
 
     kdump_module_init