kexec April 2021

kexec@lists.fedoraproject.org

10 participants
34 discussions

[PATCH v3 1/2] Implement IP netmask calculation to replace "ipcalc -m"
by Coiby Xu 19 Apr '21

19 Apr '21

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 $i "-6") if [[ "$mask_expected" != "$mask_actual" ]]; then echo "prefix="$i, "expected="$mask_expected, "acutal="$mask_actual exit fi done echo "IPv6 tests passed" for i in {0..32}; do mask_expected=$(ipcalc -m 8.8.8.8/$i| cut -d"=" -f2) mask_actual=$(cal_netmask_by_prefix $i "") if [[ "$mask_expected" != "$mask_actual" ]]; then echo "prefix="$i, "expected="$mask_expected, "acutal="$mask_actual exit fi done echo "IPv4 tests passed" i=-2 res=$(cal_netmask_by_prefix "$i" "") if [[ $? -ne 1 ]]; then echo "cal_netmask_by_prefix should exit when prefix<0" exit fi res=$(cal_netmask_by_prefix "$i" "") if [[ $? -ne 1 ]]; then echo "cal_netmask_by_prefix should exit when prefix<0" exit fi i=33 $(cal_netmask_by_prefix $i "") if [[ $? -ne 1 ]]; then echo "cal_netmask_by_prefix should exit when prefix>32 for IPv4" exit fi i=129 $(cal_netmask_by_prefix $i "-6") if [[ $? -ne 1 ]]; then echo "cal_netmask_by_prefix should exit when prefix>128 for IPv4" exit fi echo "Bad prefixes tests passed" echo "All tests passed" Reported-by: Jie Li <jieli(a)redhat.com> Signed-off-by: Coiby Xu <coxu(a)redhat.com> --- v3 -> v2: 1. Don't introduce "boolean" _ipv6 in kdump_static_ip and don't use fake boolean true/false which is not reliable [Kairui] 2. use ((1)) and((0)) to tell if it's IPv6 or not instead 3. Add tests for bad prefixes 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 | 119 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 117 insertions(+), 2 deletions(-) diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh index 8316589..aeb2e45 100755 --- a/dracut-module-setup.sh +++ b/dracut-module-setup.sh @@ -121,12 +121,122 @@ 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_flag="-6" indicates it's IPv6 +# 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_flag="$2" _ipv6 + local _bits_per_octet=8 + local _count _res _octets_per_group _octets_total _seperator _total_groups + local _max_group_value _max_group_value_repr _bits_per_group _tmp _zero_bits + + if [[ "$_ipv6_flag" == "-6" ]]; then + _ipv6=1 + else + _ipv6=0 + fi + + if [[ "$_prefix" -lt 0 || "$_prefix" -gt 128 ]] || \ + (((!_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="$2" _ipv6_flag - local _netmask _gateway _ipaddr _target _nexthop + local _netmask _gateway _ipaddr _target _nexthop _prefix _ipaddr=$(ip addr show dev $_netdev permanent | awk "/ $_srcaddr\/.* /{print \$2}") @@ -144,7 +254,12 @@ kdump_static_ip() { _srcaddr="[$_srcaddr]" _gateway="[$_gateway]" else - _netmask=$(ipcalc -m $_ipaddr | cut -d'=' -f2) + _prefix=$(cut -d'/' -f2 <<< "$_ipaddr") + _netmask=$(cal_netmask_by_prefix "$_prefix" "$_ipv6_flag") + if [[ "$?" -ne 0 ]]; then + derror "Failed to calculate netmask for $_ipaddr" + exit 1 + fi fi echo -n "${_srcaddr}::${_gateway}:${_netmask}::" fi -- 2.31.0

2 3

[PATCH] Remove dracut-squash dependency
by Tao Liu 16 Apr '21

16 Apr '21

dracut-squash is not a must-have component for kexec, nor essential for minimal host installations as BaseOS or CoreOS. Link [1][2] has already changed dracut-squash dependency from "Requires" to "Recommends". As quoting the RHEL 9 Content Structure and Guidelines: "Weak dependencies are allowed, but discouraged." Let's drop the dependency. [1]: https://github.com/coreos/fedora-coreos-config/pull/708 [2]: https://src.fedoraproject.org/rpms/kexec-tools/pull-request/4# Signed-off-by: Tao Liu <ltao(a)redhat.com> --- kexec-tools.spec | 1 - 1 file changed, 1 deletion(-) diff --git a/kexec-tools.spec b/kexec-tools.spec index 91bc0f3..dafb672 100644 --- a/kexec-tools.spec +++ b/kexec-tools.spec @@ -61,7 +61,6 @@ Requires(postun): systemd-units Requires(pre): coreutils sed zlib Requires: dracut >= 050 Requires: dracut-network >= 050 -Recommends: dracut-squash >= 050 Requires: ethtool BuildRequires: make BuildRequires: zlib-devel elfutils-devel glib2-devel bzip2-devel ncurses-devel bison flex lzo-devel snappy-devel -- 2.29.2

2 2

[PATCH v2] Write to `/var/lib/kdump` if $KDUMP_BOOTDIR not writable
by Kelvin Fan 16 Apr '21

16 Apr '21

The /boot directory on some operating systems might be read-only. If we cannot write to $KDUMP_BOOTDIR when generating the kdump initrd, attempt to place the generated initrd at `/var/lib/kdump` instead. Signed-off by: Kelvin Fan <kfan(a)redhat.com> --- 60-kdump.install | 14 ++++++++++---- kdump-lib.sh | 24 +++++++++++++++++------- kdumpctl | 4 ++-- kexec-tools.spec | 2 ++ 4 files changed, 31 insertions(+), 13 deletions(-) diff --git a/60-kdump.install b/60-kdump.install index 0a3b40e..7221e56 100755 --- a/60-kdump.install +++ b/60-kdump.install @@ -2,17 +2,23 @@ COMMAND="$1" KERNEL_VERSION="$2" -BOOT_DIR_ABS="$3" +KDUMP_INITRD_DIR_ABS="$3" KERNEL_IMAGE="$4" if ! [[ ${KERNEL_INSTALL_MACHINE_ID-x} ]]; then exit 0 fi -if [[ -d "$BOOT_DIR_ABS" ]]; then +if [[ -d "$KDUMP_INITRD_DIR_ABS" ]]; then KDUMP_INITRD="initrdkdump" else - BOOT_DIR_ABS="/boot" + # If `KDUMP_BOOTDIR` is not writable, then the kdump + # initrd must have been placed at `/var/lib/kdump` + if [[ ! -w "$KDUMP_BOOTDIR" ]]; then + KDUMP_INITRD_DIR_ABS="/var/lib/kdump" + else + KDUMP_INITRD_DIR_ABS="/boot" + fi KDUMP_INITRD="initramfs-${KERNEL_VERSION}kdump.img" fi @@ -23,7 +29,7 @@ case "$COMMAND" in # and managed by kdump service ;; remove) - rm -f -- "$BOOT_DIR_ABS/$KDUMP_INITRD" + rm -f -- "$KDUMP_INITRD_DIR_ABS/$KDUMP_INITRD" ret=$? ;; esac diff --git a/kdump-lib.sh b/kdump-lib.sh index 21271cf..5f53a8a 100755 --- a/kdump-lib.sh +++ b/kdump-lib.sh @@ -733,20 +733,30 @@ prepare_kdump_bootinfo() boot_initrdlist="initramfs-$KDUMP_KERNELVER.img initrd" for initrd in $boot_initrdlist; do if [ -f "$KDUMP_BOOTDIR/$initrd" ]; then - DEFAULT_INITRD="$KDUMP_BOOTDIR/$initrd" + defaut_initrd_base="$initrd" + DEFAULT_INITRD="$KDUMP_BOOTDIR/$defaut_initrd_base" break fi done - # Get kdump initrd from default initrd filename + # Create kdump initrd basename from default initrd basename # initramfs-5.7.9-200.fc32.x86_64.img => initramfs-5.7.9-200.fc32.x86_64kdump.img # initrd => initrdkdump - if [[ -z "$DEFAULT_INITRD" ]]; then - KDUMP_INITRD=${KDUMP_BOOTDIR}/initramfs-${KDUMP_KERNELVER}kdump.img - elif [[ $(basename $DEFAULT_INITRD) == *.* ]]; then - KDUMP_INITRD=${DEFAULT_INITRD%.*}kdump.${DEFAULT_INITRD##*.} + if [[ -z "$defaut_initrd_base" ]]; then + kdump_initrd_base=initramfs-${KDUMP_KERNELVER}kdump.img + elif [[ $defaut_initrd_base == *.* ]]; then + kdump_initrd_base=${defaut_initrd_base%.*}kdump.${DEFAULT_INITRD##*.} else - KDUMP_INITRD=${DEFAULT_INITRD}kdump + kdump_initrd_base=${defaut_initrd_base}kdump + fi + + # Place kdump initrd in `/var/lib/kdump` if `KDUMP_BOOTDIR` not writable + if [[ ! -w "$KDUMP_BOOTDIR" ]];then + var_target_initrd_dir="/var/lib/kdump" + mkdir -p "$var_target_initrd_dir" + KDUMP_INITRD="$var_target_initrd_dir/$kdump_initrd_base" + else + KDUMP_INITRD="$KDUMP_BOOTDIR/$kdump_initrd_base" fi } diff --git a/kdumpctl b/kdumpctl index c3311ad..b0846fa 100755 --- a/kdumpctl +++ b/kdumpctl @@ -151,8 +151,8 @@ rebuild_kdump_initrd() rebuild_initrd() { - if [[ ! -w "$KDUMP_BOOTDIR" ]];then - derror "$KDUMP_BOOTDIR does not have write permission. Can not rebuild $TARGET_INITRD" + if [[ ! -w $(dirname $TARGET_INITRD) ]];then + derror "$(dirname $TARGET_INITRD) does not have write permission. Cannot rebuild $TARGET_INITRD" return 1 fi diff --git a/kexec-tools.spec b/kexec-tools.spec index 24c6b36..74b7877 100644 --- a/kexec-tools.spec +++ b/kexec-tools.spec @@ -170,6 +170,7 @@ mkdir -p $RPM_BUILD_ROOT%{_unitdir} mkdir -p -m755 $RPM_BUILD_ROOT%{_bindir} mkdir -p -m755 $RPM_BUILD_ROOT%{_libdir} mkdir -p -m755 $RPM_BUILD_ROOT%{_prefix}/lib/kdump +mkdir -p -m755 $RPM_BUILD_ROOT%{_sharedstatedir}/kdump install -m 755 %{SOURCE1} $RPM_BUILD_ROOT%{_bindir}/kdumpctl install -m 755 build/sbin/kexec $RPM_BUILD_ROOT/usr/sbin/kexec @@ -335,6 +336,7 @@ done %dir %{_sysconfdir}/kdump %dir %{_sysconfdir}/kdump/pre.d %dir %{_sysconfdir}/kdump/post.d +%dir %{_sharedstatedir}/kdump %{_mandir}/man8/kdumpctl.8.gz %{_mandir}/man8/kexec.8.gz %ifarch %{ix86} x86_64 ppc64 s390x ppc64le aarch64 -- 2.29.2

2 1

[PATCH 0/8] Better support for LUKS targets
by Kairui Song 16 Apr '21

16 Apr '21

This series make kdump support LUKS targets with a lower memory usage and allow second kernel to decrypt the target automatically without password or keyfile. Current the problem with LUKS is master key decryption from key slot consume massive memory and require keyfile or password prompt, make it not very usable for kdump. This series improve it by passing master key directly. When there is a LUKS crypt target, and key is stored in dm-crypt, kdump will try to retrive the key automatically. If it success, second kernel will just work without any manual input. Output of kdumpctl restart in such case: # kdumpctl restart kdump: kexec: unloaded kdump kernel kdump: Stopping kdump: [OK] kdump: kexec: loaded kdump kernel kdump: Starting kdump: [OK] <second kernel works with normal crashkernel and no password prompt> If LUKS key is stored in kernel keyring, then kdump can't retrive the key. kdump will still work but kdumpctl will print a warning message, warn the user second kernel have some extra requirement: Output of kdumpctl restart in such case: # kdumpctl restart kdump: kexec: unloaded kdump kernel kdump: Stopping kdump: [OK] kdump: Can't get key of LUKS device /dev/vda3 kdump: Can't retrive LUKS key, crashkernel value should be large enough for LUKS key decryption, and kdump kernel will prompt for password. kdump: kexec: loaded kdump kernel kdump: Starting kdump: [OK] <second kernel need a large crashkernel and need password prompt> If LUKS key is stored in kernel keyring, and a --askpass param is passed to kdumpctl, kdumpctl will prompt for password for the LUKS device. This way it can also get the LUKS key and pass it to second kernel, bypass key decryption in second kernel, and avoids the extra memory requirement and password promption. Output of kdumpctl restart in such case: # kdumpctl restart --askpass kdump: kexec: unloaded kdump kernel kdump: Stopping kdump: [OK] Enter passphrase for /dev/vda3: <user input password here> kdump: kexec: loaded kdump kernel kdump: Starting kdump: [OK] <second kernel works with normal crashkernel and no password prompt> There is no need to rebuild initramfs for key location or LUKS config change, just need a kdumpctl restart or reload. And this only works for kdump, not for fadump as fadump reuse the initramfs and we can't append the key to the default initramfs which is too dangerous. Useful commands for testing the patch: To check LUKS key status: # cryptsetup status luks-a0d62a54-6b2f-4667-ae33-65751343e212 Output of a LUKS config with key in keyring: type: LUKS2 cipher: aes-xts-plain64 keysize: 512 bits key location: keyring device: /dev/vda3 sector size: 512 offset: 32768 sectors size: 38580224 sectors mode: read/write flags: discards Output of a LUKS config with key in dm-crypt: type: LUKS1 cipher: aes-xts-plain64 keysize: 512 bits key location: dm-crypt device: /dev/nvme0n1p2 sector size: 512 offset: 4096 sectors size: 1997780992 sectors mode: read/write flags: discards To change the key location at runtime for LUKS2 (LUKS1 is always stored in dm-crypt): Change the key location to keyring: # cryptsetup refresh luks-a0d62a54-6b2f-4667-ae33-65751343e212 Change the key location to dm-crypt: # cryptsetup refresh luks-a0d62a54-6b2f-4667-ae33-65751343e212 --disable-keyring Kairui Song (8): kdump-lib: add support to get dev name from dev ID kdump-lib: add a helper to append files into existing initramfs kdump-lib.sh: introduce a helper to get underlying crypt device mkdumprd: make use of the new get_luks_crypt_dev helper Add helper to get LUKS key of a crypted target Add master key based crypt target support kdumpctl: accept a --askpass param for loading kdump resource mkdumprd: remove LUKS target warning for non-fadump case dracut-module-setup.sh | 13 +++++ kdump-lib.sh | 126 +++++++++++++++++++++++++++++++++++++++++ kdumpctl | 124 +++++++++++++++++++++++++++++++++++----- kexec-crypt-init.sh | 18 ++++++ kexec-crypt-setup.sh | 18 ++++++ kexec-tools.spec | 4 ++ mkdumprd | 34 +++-------- 7 files changed, 296 insertions(+), 41 deletions(-) create mode 100644 kexec-crypt-init.sh create mode 100644 kexec-crypt-setup.sh -- 2.30.2

1 8

[PATCH] Don't iterate the whole /sys/devices just to find drm device
by Kairui Song 15 Apr '21

15 Apr '21

On some large systems, /sys/devices is huge and it's not a wise idea to iterate it. `find` may cause tremendous contention on the kernfs_mutex when there are already stress on /sys, and it will perform very very poorly. Simply check if drm class presents should be good enough. Signed-off-by: Kairui Song <kasong(a)redhat.com> --- dracut-module-setup.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh index ac0f196..ce05de7 100755 --- a/dracut-module-setup.sh +++ b/dracut-module-setup.sh @@ -58,7 +58,7 @@ depends() { _dep="$_dep znet" fi - if [ -n "$( find /sys/devices -name drm )" ] || [ -d /sys/module/hyperv_fb ]; then + if [ -n "$( ls -A /sys/class/drm 2>/dev/null )" ] || [ -d /sys/module/hyperv_fb ]; then add_opt_module drm fi -- 2.29.2

2 1

Is packit suitable for tests (kdump tests) that need to start a VM via QEMU and then check the console output?
by Coiby Xu 15 Apr '21

15 Apr '21

Hi, I'm adding some kdump tests to dracut to prevent dracut's change from breaking kexec-tools [1]. One suggestion is to make use of packit. The kdump tests are different from other tests because we need to reboot into the second kernel (a dump-capture kernel) to dump the system kernel's memory locally fs or to a remote fs (e.g. an nfs fs). Take the nfs-kdump test [2] as an example, here are what this test does, 1. Build the rpms for dracut and kexec-tools 2. Download the Fedora 33 Cloud Base Image 3. Start NFS server in a VM 4. For the kdump tests done as an NFS client, - Install the rpms onto another copy of Fedora 33 Cloud Base Image - Start another VM and trigger sysrq to boot into the dump-capture kernel to do vmcore dump - Check the console output to see if vmcore dump is successful I'm not sure packit is suitable for these kdump tests. For example, I need to get the path of the rpm built automatically by packit so the package can be installed onto the VM image but nowhere can I find anything related to that in packit's docs [3] or [4]. [1] https://github.com/dracutdevs/dracut/pull/1163 [2] https://src.fedoraproject.org/rpms/kexec-tools/blob/f34/f/tests/scripts/tes… [3] https://packit.dev/docs/testing-farm/ [4] https://docs.fedoraproject.org/en-US/ci/ -- Best regards, Coiby

4 16

[PATCH v2 0/3] Use a standalone kdump emergency shell
by Kairui Song 08 Apr '21

08 Apr '21

Currently kdump use some wrapper around dracut emergency service and emergency shell, this have many problems: - If dracut-initqueue failed back to emergency mode due to timeout, and faiure action is set to dump_to_rootfs, kdump will try start initqueue again, lead to double timeout error. - Dracut's emergency shell have many builtin actions, like perform dracut emergency_action, ask for root password, generate rdsosreport etc. This series remove the emergency wrapper, and use a standalone kdump emergency shell. Kdump will always perform final_action after kdump shell, so simplified version works fine. Update from V1: Fix initqueue status detection in patch 1/3, thanks to Coiby. Kairui Song (3): Don's try to restart dracut-initqueue if it's already there Remove the kdump error handler isolation wrapper Use a customized emergency shell dracut-kdump-emergency.service | 25 +++++++++---------- dracut-kdump-error-handler.service | 33 ------------------------ dracut-module-setup.sh | 1 - kdump-lib-initramfs.sh | 40 +++++++++++++++++++++++++----- kexec-tools.spec | 2 -- 5 files changed, 46 insertions(+), 55 deletions(-) delete mode 100644 dracut-kdump-error-handler.service -- 2.30.2

2 5

[PATCH v2 1/2] Implement IP netmask calculation to replace "ipcalc -m"
by Coiby Xu 07 Apr '21

07 Apr '21

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 done Reported-by: Jie Li <jieli(a)redhat.com> Signed-off-by: Coiby Xu <coxu(a)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) ]]; 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 $_srcaddr; then _ipv6_flag="-6" + _ipv6=true fi if [ -n "$_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") + if [[ "$?" -ne 0 ]]; then + derror "Failed to calculate netmask for $_ipaddr" + exit 1 + fi fi echo -n "${_srcaddr}::${_gateway}:${_netmask}::" fi -- 2.31.0

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Re: [PATCH] kdumpctl: Write to `/var/lib/kdump` if $KDUMP_BOOTDIR not writable
by Kelvin Fan 06 Apr '21

06 Apr '21

Hi Kairui, Thank you for the review! I have addressed all your comments and submitted a PATCH v2. Regarding the SELinux bit, where kexec cannot load the kdump initrd if it's in `/var/lib/kdump`, I've removed the `chcon` line. Do you (or your team) mind submitting a patch to the Fedora SELinux policy repo to update the policies regarding this new directory? This is my first time sending email patches, so I apologize in advance if I'm not following all the proper conventions. Thank you! Kelvin

1 1

[PATCH] kdumpctl: Write to `/var/lib/kdump` if $KDUMP_BOOTDIR not writable
by Kelvin Fan 06 Apr '21

06 Apr '21

2 2

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