On Wed, Apr 07, 2021 at 02:17:16PM +0800, Kairui Song wrote:
On Fri, Mar 26, 2021 at 10:46 PM Coiby Xu coxu@redhat.com wrote:
Recently, dracut-network drops depedency on dhcp-client which requires ipcalc. Thus the dependency chain "kexec-tools -> dracut-network -> dhcp-client -> ipcalc" is broken. When NIC is configured to a static IP, kexec-tools depended on "ipcalc -m" to get netmask. This commit implements the shell equivalent of "ipcalc -m".
The following test code shows cal_netmask_by_prefix is consistent with "ipcalc -m",
#!/bin/bash . dracut-module-setup.sh for i in {0..128}; do mask_expected=$(ipcalc -m fe::/$i| cut -d"=" -f2) mask_actual=$(cal_netmask_by_prefix $i true) if [[ "$mask_expected" != "$mask_actual" ]]; then echo $i, "expected=", $mask_expected, "acutal=", $mask_actual fi done for i in {0..32}; do mask_expected=$(ipcalc -m 8.8.8.8/$i| cut -d"=" -f2) mask_actual=$(cal_netmask_by_prefix $i false) if [[ "$mask_expected" != "$mask_actual" ]]; then echo $i, "expected=", $mask_expected, "acutal=", $mask_actual fi doneReported-by: Jie Li jieli@redhat.com Signed-off-by: Coiby Xu coxu@redhat.com
v1 -> v2: 1. Check subshell exit code when calling cal_netmask_by_prefix 2. Stop using die when bad prefix is passed to cal_netmask_by_prefix 3. Remove trailing spaces
dracut-module-setup.sh | 115 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 113 insertions(+), 2 deletions(-)
diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh index 8316589..ea6f7ea 100755 --- a/dracut-module-setup.sh +++ b/dracut-module-setup.sh @@ -121,17 +121,123 @@ kdump_setup_dns() { done < "/etc/resolv.conf" }
+# $1: repeat times +# $2: string to be repeated +# $3: separator +repeatedly_join_str() {
- local _count="$1"
- local _str="$2"
- local _separator="$3"
- local i _res
- if [[ "$_count" -le 0 ]]; then
echo -n ""return- fi
- i=0
- _res="$_str"
- ((_count--))
- while [[ "$i" -lt "$_count" ]]; do
((i++))_res="${_res}${_separator}${_str}"- done
- echo -n "$_res"
+}
+# $1: prefix +# $2: ipv6 or not +# Given a prefix, calculate the netmask (equivalent of "ipcalc -m") +# by concatenating three parts, +# 1) the groups with all bits set 1 +# 2) a group with partial bits set to 0 +# 3) the groups with all bits set to 0 +cal_netmask_by_prefix() {
- local _prefix="$1"
- local _ipv6="$2"
- local _bits_per_octet=8
- local _count _res _octets_per_group _octets_total _seperator _total_groups
- local _max_group_value _max_group_value_repr _bits_per_group _tmp _zero_bits
- if [[ "$_prefix" -lt 0 || ("$_ipv6" && "$_prefix" -gt 128) || \
(!"$_ipv6" && "$_prefix" -gt 32) ]]; thenHi Coiby, I think you missed a space here, should it be like this? (! "$_ipv6" && "$_prefix" -gt 32) ]]; then
derror "Bad prefix:$_prefix for calculating netmask"exit 1- fi
- if "$_ipv6"; then
_octets_per_group=2_octets_total=16_seperator=":"- else
_octets_per_group=1_octets_total=4_seperator="."- fi
- _total_groups=$((_octets_total/_octets_per_group))
- _bits_per_group=$((_octets_per_group * _bits_per_octet))
- _max_group_value=$(((1 << _bits_per_group) - 1))
- if "$_ipv6"; then
_max_group_value_repr=$(printf "%x" $_max_group_value)- else
_max_group_value_repr="$_max_group_value"- fi
- _count=$((_prefix/_octets_per_group/_bits_per_octet))
- _first_part=$(repeatedly_join_str "$_count" "$_max_group_value_repr" "$_seperator")
- _res="$_first_part"
- _tmp=$((_octets_total*_bits_per_octet-_prefix))
- _zero_bits=$(expr $_tmp % $_bits_per_group)
- if [[ "$_zero_bits" -ne 0 ]]; then
_second_part=$((_max_group_value >> _zero_bits << _zero_bits))if "$_ipv6"; then_second_part=$(printf "%x" $_second_part)fi((_count++))if [[ -z "$_first_part" ]]; then_res="$_second_part"else_res="${_first_part}${_seperator}${_second_part}"fi- fi
- _count=$((_total_groups-_count))
- if [[ "$_count" -eq 0 ]]; then
echo -n "$_res"return- fi
- if "$_ipv6" && [[ "$_count" -gt 1 ]] ; then
# use condensed notion for IPv6_third_part=":"- else
_third_part=$(repeatedly_join_str "$_count" "0" "$_seperator")- fi
- if [[ -z "$_res" ]] && ! "$_ipv6" ; then
echo -n "${_third_part}"- else
echo -n "${_res}${_seperator}${_third_part}"- fi
+}
#$1: netdev name #$2: srcaddr #if it use static ip echo it, or echo null kdump_static_ip() { local _netdev="$1" _srcaddr="$2" _ipv6_flag
- local _netmask _gateway _ipaddr _target _nexthop
local _netmask _gateway _ipaddr _target _nexthop _prefix
local _ipv6=false
_ipaddr=$(ip addr show dev $_netdev permanent | awk "/ $_srcaddr/.* /{print $2}")
if is_ipv6_address $_srcaddr; then _ipv6_flag="-6"
_ipv6=truefi
if [ -n "$_ipaddr" ]; then
@@ -144,7 +250,12 @@ kdump_static_ip() { _srcaddr="[$_srcaddr]" _gateway="[$_gateway]" else
_netmask=$(ipcalc -m $_ipaddr | cut -d'=' -f2)
_prefix=$(cut -d'/' -f2 <<< "$_ipaddr")_netmask=$(cal_netmask_by_prefix "$_prefix" "$_ipv6")I think we can avoid introduce a new _ipv6 variable by just passing _ipv6_flag, and detect if the flag is empty in cal_netmask_by_prefix.
How about introducing _ipv6 variable in cal_netmask_by_prefix instead? In cal_netmask_by_prefix, there are many places we need to tell if it's IPv6. Introducing a boolean variable could simplify the coding.
if [[ "$?" -ne 0 ]]; thenderror "Failed to calculate netmask for $_ipaddr"exit 1fi fi echo -n "${_srcaddr}::${_gateway}:${_netmask}::"-- 2.31.0 _______________________________________________ kexec mailing list -- kexec@lists.fedoraproject.org To unsubscribe send an email to kexec-leave@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kexec@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
-- Best Regards, Kairui Song