| #!/usr/bin/env sh | |
| set -e | |
| EXITCODE=0 | |
| # bits of this were adapted from lxc-checkconfig | |
| # see also https://github.com/lxc/lxc/blob/lxc-1.0.2/src/lxc/lxc-checkconfig.in | |
| possibleConfigs=" | |
| /proc/config.gz | |
| /boot/config-$(uname -r) | |
| /usr/src/linux-$(uname -r)/.config | |
| /usr/src/linux/.config | |
| " | |
| if [ $# -gt 0 ]; then | |
| CONFIG="$1" | |
| else | |
| : "${CONFIG:=/proc/config.gz}" | |
| fi | |
| if ! command -v zgrep > /dev/null 2>&1; then | |
| zgrep() { | |
| zcat "$2" | grep "$1" | |
| } | |
| fi | |
| useColor=true | |
| if [ "$NO_COLOR" = "1" ] || [ ! -t 1 ]; then | |
| useColor=false | |
| fi | |
| kernelVersion="$(uname -r)" | |
| kernelMajor="${kernelVersion%%.*}" | |
| kernelMinor="${kernelVersion#$kernelMajor.}" | |
| kernelMinor="${kernelMinor%%.*}" | |
| is_set() { | |
| zgrep "CONFIG_$1=[y|m]" "$CONFIG" > /dev/null | |
| } | |
| is_set_in_kernel() { | |
| zgrep "CONFIG_$1=y" "$CONFIG" > /dev/null | |
| } | |
| is_set_as_module() { | |
| zgrep "CONFIG_$1=m" "$CONFIG" > /dev/null | |
| } | |
| color() { | |
| # if stdout is not a terminal, then don't do color codes. | |
| if [ "$useColor" = "false" ]; then | |
| return 0 | |
| fi | |
| codes= | |
| if [ "$1" = 'bold' ]; then | |
| codes='1' | |
| shift | |
| fi | |
| if [ "$#" -gt 0 ]; then | |
| code= | |
| case "$1" in | |
| # see https://en.wikipedia.org/wiki/ANSI_escape_code#Colors | |
| black) code=30 ;; | |
| red) code=31 ;; | |
| green) code=32 ;; | |
| yellow) code=33 ;; | |
| blue) code=34 ;; | |
| magenta) code=35 ;; | |
| cyan) code=36 ;; | |
| white) code=37 ;; | |
| esac | |
| if [ "$code" ]; then | |
| codes="${codes:+$codes;}$code" | |
| fi | |
| fi | |
| printf '\033[%sm' "$codes" | |
| } | |
| wrap_color() { | |
| text="$1" | |
| shift | |
| color "$@" | |
| printf '%s' "$text" | |
| color reset | |
| echo | |
| } | |
| wrap_good() { | |
| echo "$(wrap_color "$1" white): $(wrap_color "$2" green)" | |
| } | |
| wrap_bad() { | |
| echo "$(wrap_color "$1" bold): $(wrap_color "$2" bold red)" | |
| } | |
| wrap_warning() { | |
| wrap_color >&2 "$*" red | |
| } | |
| check_flag() { | |
| if is_set_in_kernel "$1"; then | |
| wrap_good "CONFIG_$1" 'enabled' | |
| elif is_set_as_module "$1"; then | |
| wrap_good "CONFIG_$1" 'enabled (as module)' | |
| else | |
| wrap_bad "CONFIG_$1" 'missing' | |
| EXITCODE=1 | |
| fi | |
| } | |
| check_flags() { | |
| for flag in "$@"; do | |
| printf -- '- ' | |
| check_flag "$flag" | |
| done | |
| } | |
| check_command() { | |
| if command -v "$1" > /dev/null 2>&1; then | |
| wrap_good "$1 command" 'available' | |
| else | |
| wrap_bad "$1 command" 'missing' | |
| EXITCODE=1 | |
| fi | |
| } | |
| check_device() { | |
| if [ -c "$1" ]; then | |
| wrap_good "$1" 'present' | |
| else | |
| wrap_bad "$1" 'missing' | |
| EXITCODE=1 | |
| fi | |
| } | |
| check_distro_userns() { | |
| if [ ! -e /etc/os-release ]; then | |
| return | |
| fi | |
| . /etc/os-release 2> /dev/null || /bin/true | |
| case "$ID" in | |
| centos | rhel) | |
| case "$VERSION_ID" in | |
| 7*) | |
| # this is a CentOS7 or RHEL7 system | |
| grep -q 'user_namespace.enable=1' /proc/cmdline || { | |
| # no user namespace support enabled | |
| wrap_bad " (RHEL7/CentOS7" "User namespaces disabled; add 'user_namespace.enable=1' to boot command line)" | |
| EXITCODE=1 | |
| } | |
| ;; | |
| esac | |
| ;; | |
| esac | |
| } | |
| if [ ! -e "$CONFIG" ]; then | |
| wrap_warning "warning: $CONFIG does not exist, searching other paths for kernel config ..." | |
| for tryConfig in $possibleConfigs; do | |
| if [ -e "$tryConfig" ]; then | |
| CONFIG="$tryConfig" | |
| break | |
| fi | |
| done | |
| if [ ! -e "$CONFIG" ]; then | |
| wrap_warning "error: cannot find kernel config" | |
| wrap_warning " try running this script again, specifying the kernel config:" | |
| wrap_warning " CONFIG=/path/to/kernel/.config $0 or $0 /path/to/kernel/.config" | |
| exit 1 | |
| fi | |
| fi | |
| wrap_color "info: reading kernel config from $CONFIG ..." white | |
| echo | |
| echo 'Generally Necessary:' | |
| printf -- '- ' | |
| if [ "$(stat -f -c %t /sys/fs/cgroup 2> /dev/null)" = '63677270' ]; then | |
| wrap_good 'cgroup hierarchy' 'cgroupv2' | |
| cgroupv2ControllerFile='/sys/fs/cgroup/cgroup.controllers' | |
| if [ -f "$cgroupv2ControllerFile" ]; then | |
| echo ' Controllers:' | |
| for controller in cpu cpuset io memory pids; do | |
| if grep -qE '(^| )'"$controller"'($| )' "$cgroupv2ControllerFile"; then | |
| echo " - $(wrap_good "$controller" 'available')" | |
| else | |
| echo " - $(wrap_bad "$controller" 'missing')" | |
| fi | |
| done | |
| else | |
| wrap_bad "$cgroupv2ControllerFile" 'nonexistent??' | |
| fi | |
| # TODO find an efficient way to check if cgroup.freeze exists in subdir | |
| else | |
| cgroupSubsystemDir="$(sed -rne '/^[^ ]+ ([^ ]+) cgroup ([^ ]*,)?(cpu|cpuacct|cpuset|devices|freezer|memory)[, ].*$/ { s//\1/p; q }' /proc/mounts)" | |
| cgroupDir="$(dirname "$cgroupSubsystemDir")" | |
| if [ -d "$cgroupDir/cpu" ] || [ -d "$cgroupDir/cpuacct" ] || [ -d "$cgroupDir/cpuset" ] || [ -d "$cgroupDir/devices" ] || [ -d "$cgroupDir/freezer" ] || [ -d "$cgroupDir/memory" ]; then | |
| echo "$(wrap_good 'cgroup hierarchy' 'properly mounted') [$cgroupDir]" | |
| else | |
| if [ "$cgroupSubsystemDir" ]; then | |
| echo "$(wrap_bad 'cgroup hierarchy' 'single mountpoint!') [$cgroupSubsystemDir]" | |
| else | |
| wrap_bad 'cgroup hierarchy' 'nonexistent??' | |
| fi | |
| EXITCODE=1 | |
| echo " $(wrap_color '(see https://github.com/tianon/cgroupfs-mount)' yellow)" | |
| fi | |
| fi | |
| if [ "$(cat /sys/module/apparmor/parameters/enabled 2> /dev/null)" = 'Y' ]; then | |
| printf -- '- ' | |
| if command -v apparmor_parser > /dev/null 2>&1; then | |
| wrap_good 'apparmor' 'enabled and tools installed' | |
| else | |
| wrap_bad 'apparmor' 'enabled, but apparmor_parser missing' | |
| printf ' ' | |
| if command -v apt-get > /dev/null 2>&1; then | |
| wrap_color '(use "apt-get install apparmor" to fix this)' | |
| elif command -v yum > /dev/null 2>&1; then | |
| wrap_color '(your best bet is "yum install apparmor-parser")' | |
| else | |
| wrap_color '(look for an "apparmor" package for your distribution)' | |
| fi | |
| EXITCODE=1 | |
| fi | |
| fi | |
| check_flags \ | |
| NAMESPACES NET_NS PID_NS IPC_NS UTS_NS \ | |
| CGROUPS CGROUP_CPUACCT CGROUP_DEVICE CGROUP_FREEZER CGROUP_SCHED CPUSETS MEMCG \ | |
| KEYS \ | |
| VETH BRIDGE BRIDGE_NETFILTER \ | |
| IP_NF_FILTER IP_NF_MANGLE IP_NF_TARGET_MASQUERADE \ | |
| NETFILTER_XT_MATCH_ADDRTYPE \ | |
| NETFILTER_XT_MATCH_CONNTRACK \ | |
| NETFILTER_XT_MATCH_IPVS \ | |
| NETFILTER_XT_MARK \ | |
| IP_NF_NAT NF_NAT \ | |
| POSIX_MQUEUE | |
| # (POSIX_MQUEUE is required for bind-mounting /dev/mqueue into containers) | |
| if [ "$kernelMajor" -lt 4 ] || ([ "$kernelMajor" -eq 4 ] && [ "$kernelMinor" -lt 8 ]); then | |
| check_flags DEVPTS_MULTIPLE_INSTANCES | |
| fi | |
| if [ "$kernelMajor" -lt 5 ] || [ "$kernelMajor" -eq 5 -a "$kernelMinor" -le 1 ]; then | |
| check_flags NF_NAT_IPV4 | |
| fi | |
| if [ "$kernelMajor" -lt 5 ] || [ "$kernelMajor" -eq 5 -a "$kernelMinor" -le 2 ]; then | |
| check_flags NF_NAT_NEEDED | |
| fi | |
| # check availability of BPF_CGROUP_DEVICE support | |
| if [ "$kernelMajor" -ge 5 ] || ([ "$kernelMajor" -eq 4 ] && [ "$kernelMinor" -ge 15 ]); then | |
| check_flags CGROUP_BPF | |
| fi | |
| echo | |
| echo 'Optional Features:' | |
| { | |
| check_flags USER_NS | |
| check_distro_userns | |
| } | |
| { | |
| check_flags SECCOMP | |
| check_flags SECCOMP_FILTER | |
| } | |
| { | |
| check_flags CGROUP_PIDS | |
| } | |
| { | |
| check_flags MEMCG_SWAP | |
| # Kernel v5.8+ removes MEMCG_SWAP_ENABLED. | |
| if [ "$kernelMajor" -lt 5 ] || [ "$kernelMajor" -eq 5 -a "$kernelMinor" -le 8 ]; then | |
| CODE=${EXITCODE} | |
| check_flags MEMCG_SWAP_ENABLED | |
| # FIXME this check is cgroupv1-specific | |
| if [ -e /sys/fs/cgroup/memory/memory.memsw.limit_in_bytes ]; then | |
| echo " $(wrap_color '(cgroup swap accounting is currently enabled)' bold black)" | |
| EXITCODE=${CODE} | |
| elif is_set MEMCG_SWAP && ! is_set MEMCG_SWAP_ENABLED; then | |
| echo " $(wrap_color '(cgroup swap accounting is currently not enabled, you can enable it by setting boot option "swapaccount=1")' bold black)" | |
| fi | |
| else | |
| # Kernel v5.8+ enables swap accounting by default. | |
| echo " $(wrap_color '(cgroup swap accounting is currently enabled)' bold black)" | |
| fi | |
| } | |
| { | |
| if is_set LEGACY_VSYSCALL_NATIVE; then | |
| printf -- '- ' | |
| wrap_bad "CONFIG_LEGACY_VSYSCALL_NATIVE" 'enabled' | |
| echo " $(wrap_color '(dangerous, provides an ASLR-bypassing target with usable ROP gadgets.)' bold black)" | |
| elif is_set LEGACY_VSYSCALL_EMULATE; then | |
| printf -- '- ' | |
| wrap_good "CONFIG_LEGACY_VSYSCALL_EMULATE" 'enabled' | |
| elif is_set LEGACY_VSYSCALL_NONE; then | |
| printf -- '- ' | |
| wrap_bad "CONFIG_LEGACY_VSYSCALL_NONE" 'enabled' | |
| echo " $(wrap_color '(containers using eglibc <= 2.13 will not work. Switch to' bold black)" | |
| echo " $(wrap_color ' "CONFIG_VSYSCALL_[NATIVE|EMULATE]" or use "vsyscall=[native|emulate]"' bold black)" | |
| echo " $(wrap_color ' on kernel command line. Note that this will disable ASLR for the,' bold black)" | |
| echo " $(wrap_color ' VDSO which may assist in exploiting security vulnerabilities.)' bold black)" | |
| # else Older kernels (prior to 3dc33bd30f3e, released in v4.40-rc1) do | |
| # not have these LEGACY_VSYSCALL options and are effectively | |
| # LEGACY_VSYSCALL_EMULATE. Even older kernels are presumably | |
| # effectively LEGACY_VSYSCALL_NATIVE. | |
| fi | |
| } | |
| if [ "$kernelMajor" -lt 4 ] || ([ "$kernelMajor" -eq 4 ] && [ "$kernelMinor" -le 5 ]); then | |
| check_flags MEMCG_KMEM | |
| fi | |
| if [ "$kernelMajor" -lt 3 ] || ([ "$kernelMajor" -eq 3 ] && [ "$kernelMinor" -le 18 ]); then | |
| check_flags RESOURCE_COUNTERS | |
| fi | |
| if [ "$kernelMajor" -lt 3 ] || ([ "$kernelMajor" -eq 3 ] && [ "$kernelMinor" -le 13 ]); then | |
| netprio=NETPRIO_CGROUP | |
| else | |
| netprio=CGROUP_NET_PRIO | |
| fi | |
| if [ "$kernelMajor" -lt 5 ]; then | |
| check_flags IOSCHED_CFQ CFQ_GROUP_IOSCHED | |
| fi | |
| check_flags \ | |
| BLK_CGROUP BLK_DEV_THROTTLING \ | |
| CGROUP_PERF \ | |
| CGROUP_HUGETLB \ | |
| NET_CLS_CGROUP $netprio \ | |
| CFS_BANDWIDTH FAIR_GROUP_SCHED \ | |
| IP_NF_TARGET_REDIRECT \ | |
| IP_VS \ | |
| IP_VS_NFCT \ | |
| IP_VS_PROTO_TCP \ | |
| IP_VS_PROTO_UDP \ | |
| IP_VS_RR \ | |
| SECURITY_SELINUX \ | |
| SECURITY_APPARMOR | |
| if ! is_set EXT4_USE_FOR_EXT2; then | |
| check_flags EXT3_FS EXT3_FS_XATTR EXT3_FS_POSIX_ACL EXT3_FS_SECURITY | |
| if ! is_set EXT3_FS || ! is_set EXT3_FS_XATTR || ! is_set EXT3_FS_POSIX_ACL || ! is_set EXT3_FS_SECURITY; then | |
| echo " $(wrap_color '(enable these ext3 configs if you are using ext3 as backing filesystem)' bold black)" | |
| fi | |
| fi | |
| check_flags EXT4_FS EXT4_FS_POSIX_ACL EXT4_FS_SECURITY | |
| if ! is_set EXT4_FS || ! is_set EXT4_FS_POSIX_ACL || ! is_set EXT4_FS_SECURITY; then | |
| if is_set EXT4_USE_FOR_EXT2; then | |
| echo " $(wrap_color 'enable these ext4 configs if you are using ext3 or ext4 as backing filesystem' bold black)" | |
| else | |
| echo " $(wrap_color 'enable these ext4 configs if you are using ext4 as backing filesystem' bold black)" | |
| fi | |
| fi | |
| echo '- Network Drivers:' | |
| echo " - \"$(wrap_color 'overlay' blue)\":" | |
| check_flags VXLAN BRIDGE_VLAN_FILTERING | sed 's/^/ /' | |
| echo ' Optional (for encrypted networks):' | |
| check_flags CRYPTO CRYPTO_AEAD CRYPTO_GCM CRYPTO_SEQIV CRYPTO_GHASH \ | |
| XFRM XFRM_USER XFRM_ALGO INET_ESP NETFILTER_XT_MATCH_BPF | sed 's/^/ /' | |
| if [ "$kernelMajor" -lt 5 ] || [ "$kernelMajor" -eq 5 -a "$kernelMinor" -le 3 ]; then | |
| check_flags INET_XFRM_MODE_TRANSPORT | sed 's/^/ /' | |
| fi | |
| echo " - \"$(wrap_color 'ipvlan' blue)\":" | |
| check_flags IPVLAN | sed 's/^/ /' | |
| echo " - \"$(wrap_color 'macvlan' blue)\":" | |
| check_flags MACVLAN DUMMY | sed 's/^/ /' | |
| echo " - \"$(wrap_color 'ftp,tftp client in container' blue)\":" | |
| check_flags NF_NAT_FTP NF_CONNTRACK_FTP NF_NAT_TFTP NF_CONNTRACK_TFTP | sed 's/^/ /' | |
| # only fail if no storage drivers available | |
| CODE=${EXITCODE} | |
| EXITCODE=0 | |
| STORAGE=1 | |
| echo '- Storage Drivers:' | |
| echo " - \"$(wrap_color 'btrfs' blue)\":" | |
| check_flags BTRFS_FS | sed 's/^/ /' | |
| check_flags BTRFS_FS_POSIX_ACL | sed 's/^/ /' | |
| [ "$EXITCODE" = 0 ] && STORAGE=0 | |
| EXITCODE=0 | |
| echo " - \"$(wrap_color 'overlay' blue)\":" | |
| check_flags OVERLAY_FS | sed 's/^/ /' | |
| [ "$EXITCODE" = 0 ] && STORAGE=0 | |
| EXITCODE=0 | |
| echo " - \"$(wrap_color 'zfs' blue)\":" | |
| printf ' - ' | |
| check_device /dev/zfs | |
| printf ' - ' | |
| check_command zfs | |
| printf ' - ' | |
| check_command zpool | |
| [ "$EXITCODE" = 0 ] && STORAGE=0 | |
| EXITCODE=0 | |
| EXITCODE=$CODE | |
| [ "$STORAGE" = 1 ] && EXITCODE=1 | |
| echo | |
| check_limit_over() { | |
| if [ "$(cat "$1")" -le "$2" ]; then | |
| wrap_bad "- $1" "$(cat "$1")" | |
| wrap_color " This should be set to at least $2, for example set: sysctl -w kernel/keys/root_maxkeys=1000000" bold black | |
| EXITCODE=1 | |
| else | |
| wrap_good "- $1" "$(cat "$1")" | |
| fi | |
| } | |
| echo 'Limits:' | |
| check_limit_over /proc/sys/kernel/keys/root_maxkeys 10000 | |
| echo | |
| exit $EXITCODE |