Simplify setup_znet by copying connection profile to initrd

/usr/lib/udev/ccw_init [1] shipped by s390utils extracts the values of
SUBCHANNELS, NETTYPE and LAYER2 from /etc/sysconfig/network-scripts/ifcfg-*
or /etc/NetworkManager/system-connections/*.nmconnection to activate znet
network device. If the connection profile is copied to initrd,
there is no need to set up the "rd.znet" dracut cmdline parameter.

There are two cases addressed by this commit,
 1. znet network interface is a slave of bonding/teaming/vlan/bridging
    network. The connection profile has been copied to initrd by
    kdump_copy_nmconnection_file and it contains the info needed by
    ccw_init.
 2. znet network interface is a slave of bonding/teaming/vlan/bridging
    network. The corresponding ifcfg-*/*.nmconnection file may not contain
    info like SUBCHANNELS [2]. In this case, copy the ifcfg-*/*.nmconnection
    file that has this info to the kdump initrd. Also to prevent the copied
    connection profile from being chosen by NM, set
    connection.autoconnect=false for this connection profile.

With this implementation, there is also no need to check if znet is
used beforehand.

Note
1. ccw_init doesn't care if SUBCHANNELS, NETTYPE and LAYER2 comes from
   an active NM profile or not. If an inactive NM profile contains this
   info, it needs to be copied to the kdump initrd as well.
2. "rd.znet_ifname=$_netdev:${SUBCHANNELS}" is no longer needed needed
   because now there is no renaming of s390x network interfaces when
   reusing NetworkManager profiles. rd.znet_ifname was introduced in
   commit ce0305d ("Add a new option 'rd.znet_ifname' in order to use it
   in udev rules") to address the special case of non-persistent
   MAC address by renaming a network interface by SUBCHANNELS.

[1] https://src.fedoraproject.org/rpms/s390utils/blob/rawhide/f/ccw_init
[2] https://bugzilla.redhat.com/show_bug.cgi?id=2064708

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

dracut-module-setup.sh

@@ -467,62 +467,48 @@ kdump_setup_vlan() {
     _save_kdump_netifs "$_parent_netif"
 }
 
-# find online znet device
+_find_znet_nmconnection() {
-# return ifname (_netdev)
+    LANG=C grep -s -E -i -l \
-# code reaped from the list_configured function of
+        "^s390-subchannels=([0-9]\.[0-9]\.[a-f0-9]+;){0,2}" \
-# https://github.com/hreinecke/s390-tools/blob/master/zconf/znetconf
+        "$1"/*.nmconnection | LC_ALL=C sed -e "$2"
-find_online_znet_device() {
-    local CCWGROUPBUS_DEVICEDIR="/sys/bus/ccwgroup/devices"
-    local NETWORK_DEVICES d ifname ONLINE
-
-    [[ ! -d $CCWGROUPBUS_DEVICEDIR ]] && return
-    NETWORK_DEVICES=$(find $CCWGROUPBUS_DEVICEDIR)
-    for d in $NETWORK_DEVICES; do
-        [[ ! -f "$d/online" ]] && continue
-        read -r ONLINE < "$d/online"
-        if [[ $ONLINE -ne 1 ]]; then
-            continue
-        fi
-        # determine interface name, if there (only for qeth and if
-        # device is online)
-        if [[ -f $d/if_name ]]; then
-            read -r ifname < "$d/if_name"
-        elif [[ -d $d/net ]]; then
-            ifname=$(ls "$d/net/")
-        fi
-        [[ -n $ifname ]] && break
-    done
-    echo -n "$ifname"
 }
 
-# setup s390 znet cmdline
+# setup s390 znet
-# $1: netdev (ifname)
+#
-# $2: nmcli connection path
+# Note part of code is extracted from ccw_init provided by s390utils
 kdump_setup_znet() {
-    local _netdev="$1"
+    local _config_file _unique_name _NM_conf_dir
-    local _conpath="$2"
+    local __sed_discard_ignored_files='/\(~\|\.bak\|\.old\|\.orig\|\.rpmnew\|\.rpmorig\|\.rpmsave\)$/d'
-    local s390_prefix="802-3-ethernet.s390-"
-    local _options=""
-    local NETTYPE
-    local SUBCHANNELS
 
-    NETTYPE=$(get_nmcli_field_by_conpath "${s390_prefix}nettype" "$_conpath")
+    if [[ "$(uname -m)" != "s390x" ]]; then
-    SUBCHANNELS=$(get_nmcli_field_by_conpath "${s390_prefix}subchannels" "$_conpath")
+        return
-    _options=$(get_nmcli_field_by_conpath "${s390_prefix}options" "$_conpath")
-
-    if [[ -z $NETTYPE || -z $SUBCHANNELS || -z $_options ]]; then
-        dwarning "Failed to get znet configuration via nmlci output. Now try sourcing ifcfg script."
-        source_ifcfg_file "$_netdev"
-        for i in $OPTIONS; do
-            _options=${_options},$i
-        done
     fi
 
-    if [[ -z $NETTYPE || -z $SUBCHANNELS || -z $_options ]]; then
+    _NM_conf_dir="/etc/NetworkManager/system-connections"
-        exit 1
+
+    _config_file=$(_find_znet_nmconnection "$initdir/$_NM_conf_dir" "$__sed_discard_ignored_files")
+    if [[ -n "$_config_file" ]]; then
+        ddebug "$_config_file has already contained the znet config"
+        return
+    fi
+
+    _config_file=$(LANG=C grep -s -E -i -l \
+        "^[[:space:]]*SUBCHANNELS=['\"]?([0-9]\.[0-9]\.[a-f0-9]+,){0,2}" \
+        /etc/sysconfig/network-scripts/ifcfg-* \
+        | LC_ALL=C sed -e "$__sed_discard_ignored_files")
+
+    if [[ -z "$_config_file" ]]; then
+        _config_file=$(_find_znet_nmconnection "$_NM_conf_dir" "$__sed_discard_ignored_files")
+    fi
+
+    if [[ -n "$_config_file" ]]; then
+        _unique_name=$(cat /proc/sys/kernel/random/uuid)
+        nmcli connection clone --temporary "$_config_file" "$_unique_name" &> >(ddebug)
+        nmcli connection modify --temporary "$_unique_name" connection.autoconnect false
+        inst "/run/NetworkManager/system-connections/${_unique_name}.nmconnection" "${_NM_conf_dir}/${_unique_name}.nmconnection"
+        nmcli connection del "$_unique_name" &> >(ddebug)
     fi
 
-    echo "rd.znet=${NETTYPE},${SUBCHANNELS},${_options} rd.znet_ifname=$_netdev:${SUBCHANNELS}" > "${initdir}/etc/cmdline.d/30znet.conf"
 }
 
 kdump_get_remote_ip() {
@@ -542,22 +528,12 @@ kdump_get_remote_ip() {
 # $1: destination host
 kdump_collect_netif_usage() {
     local _destaddr _srcaddr _route _netdev
-    local _znet_netdev _znet_conpath
 
     _destaddr=$(kdump_get_remote_ip "$1")
     _route=$(kdump_get_ip_route "$_destaddr")
     _srcaddr=$(kdump_get_ip_route_field "$_route" "src")
     _netdev=$(kdump_get_ip_route_field "$_route" "dev")
 
-    _znet_netdev=$(find_online_znet_device)
-    if [[ -n $_znet_netdev ]]; then
-        _znet_conpath=$(get_nmcli_connection_apath_by_ifname "$_znet_netdev")
-        if ! (kdump_setup_znet "$_znet_netdev" "$_znet_conpath"); then
-            derror "Failed to set up znet"
-            exit 1
-        fi
-    fi
-
     if kdump_is_bridge "$_netdev"; then
         kdump_setup_bridge "$_netdev"
     elif kdump_is_bond "$_netdev"; then
@@ -594,6 +570,7 @@ kdump_install_net() {
     if [[ -n "$_netifs" ]]; then
         kdump_install_nmconnections
         apply_nm_initrd_generator_timeouts
+        kdump_setup_znet
         kdump_install_nm_netif_allowlist "$_netifs"
         kdump_install_nic_driver "$_netifs"
     fi