sonic-buildimage/files/initramfs-tools/union-mount.j2
xumia 76a395cdbf
[secure boot] Support rw files allowlist (#4585)
* Support rw files allowlist for Sonic Secure Boot
* Improve the performance
* fix bug
* Move the config description into a md file
* Change to use a simple way to remove the blank line
* Support chmod a-x in rw folder
* Change function name
* Change some unnecessary words
2020-06-13 00:10:13 -07:00

130 lines
4.8 KiB
Django/Jinja

#!/bin/sh -e
PREREQS="varlog"
prereqs() { echo "$PREREQS"; }
case $1 in
prereqs)
prereqs
exit 0
;;
esac
set_tmpfs_log_partition_size()
{
varlogsize=128
# NOTE: certain platforms, when reaching initramfs stage, have a small
# limit of mounting tmpfs partition, potentially due to amount
# of RAM available in this stage. e.g. Arista 7050-qx32[s] and 7060-cx32s
[ X"$aboot_platform" = X"x86_64-arista_7050_qx32" ] && return
[ X"$aboot_platform" = X"x86_64-arista_7050_qx32s" ] && return
[ X"$aboot_platform" = X"x86_64-arista_7060_cx32s" ] && return
[ X"$aboot_platform" = X"x86_64-arista_7060cx2_32s" ] && return
# set varlogsize to existing var-log.ext4 size
if [ -f ${rootmnt}/host/disk-img/var-log.ext4 ]; then
varlogsize=$(ls -l ${rootmnt}/host/disk-img/var-log.ext4 | awk '{print $5}')
varlogsize=$(($varlogsize/1024/1024))
fi
# make sure varlogsize is between 5% to 10% of total memory size
memkb=$(grep MemTotal /proc/meminfo | awk '{print $2}')
memmb=$(($memkb/1024))
minsize=$(($memmb*5/100))
maxsize=$(($memmb*10/100))
[ $minsize -ge $varlogsize ] && varlogsize=$minsize
[ $maxsize -le $varlogsize ] && varlogsize=$maxsize
}
remove_not_in_allowlist_files()
{
image_dir=$1
allowlist_file=${rootmnt}/host/$image_dir/allowlist_paths.conf
# Return if the secure_boot_enable option is not set
if ! (cat /proc/cmdline | grep -i -q "secure_boot_enable=[y1]"); then
return
fi
# Return if the allowlist file does not exist
if ! test -f "${allowlist_file}"; then
echo "The file ${allowlist_file} is missing, failed to mount rw folder." 1>&2
exit 1
fi
rw_dir=${rootmnt}/host/$image_dir/rw
# Set the grep pattern file, remove the blank line in config file
allowlist_pattern_file=${rootmnt}/host/$image_dir/allowlist_paths.pattern
awk -v rw_dir="$rw_dir" 'NF {print rw_dir"/"$0"$"}' ${allowlist_file} > $allowlist_pattern_file
# Find the files in the rw folder, and remove the files not in the allowlist
find ${rw_dir} -type f | grep -v -f $allowlist_pattern_file | xargs /bin/rm -f
rm -f $allowlist_pattern_file
}
## Mount the overlay file system: rw layer over squashfs
image_dir=$(cat /proc/cmdline | sed -e 's/.*loop=\(\S*\)\/.*/\1/')
mkdir -p ${rootmnt}/host/$image_dir/rw
mkdir -p ${rootmnt}/host/$image_dir/work
## Remove the files not in allowlist in the rw folder
remove_not_in_allowlist_files "$image_dir"
## Remove the executable permission for all the files in rw folder except home folder
rw_dir=${rootmnt}/host/$image_dir/rw
find ${rw_dir} -type f -not -path ${rw_dir}/home -exec chmod a-x {} +
mount -n -o lowerdir=${rootmnt},upperdir=${rootmnt}/host/$image_dir/rw,workdir=${rootmnt}/host/$image_dir/work -t overlay root-overlay ${rootmnt}
## Check if the root block device is still there
[ -b ${ROOT} ] || mdev -s
case "${ROOT}" in
ubi*)
mtd=$(cat /proc/cmdline | sed -e 's/.*ubi.mtd=\([0-9]\) .*/\1/')
if [ ! -f /dev/${ROOT}_0 ]; then
ubiattach /dev/ubi_ctrl -m $mtd || true
fi
mount -t ubifs /dev/${ROOT}_0 ${rootmnt}/host
;;
*)
## Mount the raw partition again
mount ${ROOT} ${rootmnt}/host
;;
esac
mkdir -p ${rootmnt}/var/lib/docker
if [ -f ${rootmnt}/host/$image_dir/{{ FILESYSTEM_DOCKERFS }} ]; then
## mount tmpfs and extract docker into it
mount -t tmpfs -o rw,nodev,size={{ DOCKER_RAMFS_SIZE }} tmpfs ${rootmnt}/var/lib/docker
tar xz --numeric-owner -f ${rootmnt}/host/$image_dir/{{ FILESYSTEM_DOCKERFS }} -C ${rootmnt}/var/lib/docker
else
## Mount the working directory of docker engine in the raw partition, bypass the overlay
mount --bind ${rootmnt}/host/$image_dir/{{ DOCKERFS_DIR }} ${rootmnt}/var/lib/docker
fi
## Mount the boot directory in the raw partition, bypass the overlay
mkdir -p ${rootmnt}/boot
mount --bind ${rootmnt}/host/$image_dir/boot ${rootmnt}/boot
## Mount loop device or tmpfs for /var/log
onie_platform=""
aboot_platform=""
. ${rootmnt}/host/machine.conf
if [ X"$aboot_platform" = X"x86_64-arista_7050_qx32" ] ||
[ X"$aboot_platform" = X"x86_64-arista_7050_qx32s" ] ||
[ X"$aboot_platform" = X"x86_64-arista_7060_cx32s" ]
then
set_tmpfs_log_partition_size
mount -t tmpfs -o rw,nosuid,nodev,size=${varlogsize}M tmpfs ${rootmnt}/var/log
[ -f ${rootmnt}/host/disk-img/var-log.ext4 ] && rm -rf ${rootmnt}/host/disk-img/var-log.ext4
else
[ -f ${rootmnt}/host/disk-img/var-log.ext4 ] && fsck.ext4 -v -p ${rootmnt}/host/disk-img/var-log.ext4 2>&1 \
| gzip -c >> /tmp/fsck.log.gz
[ -f ${rootmnt}/host/disk-img/var-log.ext4 ] && mount -t ext4 -o loop,rw ${rootmnt}/host/disk-img/var-log.ext4 ${rootmnt}/var/log
fi
## fscklog file: /tmp will be lost when overlayfs is mounted
if [ -f /tmp/fsck.log.gz ]; then
mv /tmp/fsck.log.gz ${rootmnt}/var/log
fi