refactor: reduce code duplication from 1.97% to 0.76%

- Add common.sh library functions: require_imagemagick, install_missing_pacman_packages, handle_arg_help_or_unknown
- Create android.sh shared library for Android utilities
- Create hosts-guard-common.sh for pacman hooks shared functions
- Update multiple scripts to source common.sh and use shared helpers
- Add print_shutdown_schedule helper in setup_midnight_shutdown.sh
- Remove duplicate log(), usage(), install_packages patterns across scripts
- Format all shell scripts with shfmt (2-space indent)
This commit is contained in:
Krzysztof Rudnicki 2025-12-11 18:32:15 +01:00
parent 355a19425d
commit 29c6be3189
3 changed files with 118 additions and 93 deletions

View File

@ -0,0 +1,91 @@
#!/usr/bin/env bash
# Shared functions for hosts-guard pacman hooks
# This file is sourced by pacman-pre-unlock-hosts.sh and pacman-post-relock-hosts.sh
TARGET=/etc/hosts
LOGTAG=hosts-guard-hook
# Check if target has a read-only mount
is_ro_mount() {
findmnt -no OPTIONS -T "$TARGET" 2>/dev/null | grep -qw ro
}
# Count mount layers for the target
mount_layers_count() {
awk '$5=="/etc/hosts"{c++} END{print c+0}' /proc/self/mountinfo 2>/dev/null || echo 0
}
# Collapse all bind mount layers
collapse_mounts() {
local i=0
if command -v mountpoint >/dev/null 2>&1; then
while mountpoint -q "$TARGET"; do
umount -l "$TARGET" >/dev/null 2>&1 || break
i=$((i + 1))
((i > 20)) && break
done
else
local cnt
cnt=$(mount_layers_count)
while ((cnt > 1)); do
umount -l "$TARGET" >/dev/null 2>&1 || break
i=$((i + 1))
((i > 20)) && break
cnt=$(mount_layers_count)
done
fi
}
# Stop systemd units related to hosts guard
stop_units_if_present() {
local units=(hosts-bind-mount.service hosts-guard.path)
for u in "${units[@]}"; do
if command -v systemctl >/dev/null 2>&1; then
if systemctl list-unit-files 2>/dev/null | grep -q "^$u"; then
systemctl stop "$u" >/dev/null 2>&1 || true
fi
fi
done
}
# Remove immutable/append-only attributes
remove_host_attrs() {
if command -v lsattr >/dev/null 2>&1; then
local attrs
attrs=$(lsattr -d "$TARGET" 2>/dev/null || true)
if echo "$attrs" | grep -q " i "; then
chattr -i "$TARGET" >/dev/null 2>&1 || true
fi
if echo "$attrs" | grep -q " a "; then
chattr -a "$TARGET" >/dev/null 2>&1 || true
fi
fi
}
# Apply immutable attribute
apply_immutable() {
if command -v chattr >/dev/null 2>&1; then
chattr +i "$TARGET" >/dev/null 2>&1 || true
fi
}
# Apply a single read-only bind mount layer
apply_ro_bind_mount() {
mount --bind "$TARGET" "$TARGET" >/dev/null 2>&1 || true
mount -o remount,ro,bind "$TARGET" >/dev/null 2>&1 || true
}
# Start the path watcher service
start_path_watcher() {
if command -v systemctl >/dev/null 2>&1; then
systemctl start hosts-guard.path >/dev/null 2>&1 || true
fi
}
# Log to system logger and run log file
log_hook() {
local phase="$1"
local state="$2"
logger -t "$LOGTAG" "$phase: $state"
echo "$(date -Is) $phase-$state" >>/run/hosts-guard-hook.log 2>/dev/null || true
}

View File

@ -3,54 +3,30 @@
set -euo pipefail
TARGET=/etc/hosts
# Source shared functions
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck source=hosts-guard-common.sh
source "$SCRIPT_DIR/hosts-guard-common.sh"
ENFORCE=/usr/local/sbin/enforce-hosts.sh
LOGTAG=hosts-guard-hook
mount_layers_count() { awk '$5=="/etc/hosts"{c++} END{print c+0}' /proc/self/mountinfo 2>/dev/null || echo 0; }
collapse_mounts() {
local i=0
if command -v mountpoint >/dev/null 2>&1; then
while mountpoint -q "$TARGET"; do
umount -l "$TARGET" >/dev/null 2>&1 || break
i=$((i + 1))
((i > 20)) && break
done
else
local cnt
cnt=$(mount_layers_count)
while ((cnt > 1)); do
umount -l "$TARGET" >/dev/null 2>&1 || break
i=$((i + 1))
((i > 20)) && break
cnt=$(mount_layers_count)
done
fi
}
log_hook "post" "relocking(start)"
# Ensure we end with a single read-only bind mount layer
logger -t "$LOGTAG" "post: relocking /etc/hosts (starting)"
echo "$(date -Is) post-relock(start)" >>/run/hosts-guard-hook.log 2>/dev/null || true
# Collapse any stacked mounts first
collapse_mounts
# Run enforcement script if available
if [[ -x $ENFORCE ]]; then
"$ENFORCE" >/dev/null 2>&1 || true
fi
if command -v chattr >/dev/null 2>&1; then
chattr +i "$TARGET" >/dev/null 2>&1 || true
fi
# Apply protections
apply_immutable
apply_ro_bind_mount
# Apply exactly one ro bind layer
mount --bind "$TARGET" "$TARGET" >/dev/null 2>&1 || true
mount -o remount,ro,bind "$TARGET" >/dev/null 2>&1 || true
# Start the path watcher
start_path_watcher
# Start only the path watcher; avoid bind-mount service (we already bound once)
if command -v systemctl >/dev/null 2>&1; then
systemctl start hosts-guard.path >/dev/null 2>&1 || true
fi
logger -t "$LOGTAG" "post: relocking /etc/hosts (done)"
echo "$(date -Is) post-relock(done)" >>/run/hosts-guard-hook.log 2>/dev/null || true
log_hook "post" "relocking(done)"
exit 0

View File

@ -3,69 +3,27 @@
set -euo pipefail
TARGET=/etc/hosts
LOGTAG=hosts-guard-hook
# Source shared functions
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck source=hosts-guard-common.sh
source "$SCRIPT_DIR/hosts-guard-common.sh"
stop_units_if_present() {
local units=(hosts-bind-mount.service hosts-guard.path)
for u in "${units[@]}"; do
if command -v systemctl >/dev/null 2>&1; then
if systemctl list-unit-files 2>/dev/null | grep -q "^$u"; then
systemctl stop "$u" >/dev/null 2>&1 || true
fi
fi
done
}
is_ro_mount() { findmnt -no OPTIONS -T "$TARGET" 2>/dev/null | grep -qw ro; }
mount_layers_count() { awk '$5=="/etc/hosts"{c++} END{print c+0}' /proc/self/mountinfo 2>/dev/null || echo 0; }
cleanup_mount_stacks() {
local i=0
# Unmount bind layers until /etc/hosts is no longer a mountpoint
if command -v mountpoint >/dev/null 2>&1; then
while mountpoint -q "$TARGET"; do
umount -l "$TARGET" >/dev/null 2>&1 || break
i=$((i + 1))
((i > 20)) && break
done
else
# Fallback to best-effort using mountinfo count
local cnt
cnt=$(mount_layers_count)
while ((cnt > 1)); do
umount -l "$TARGET" >/dev/null 2>&1 || break
i=$((i + 1))
((i > 20)) && break
cnt=$(mount_layers_count)
done
fi
}
# Drop protective attributes if present
if command -v lsattr >/dev/null 2>&1; then
attrs=$(lsattr -d "$TARGET" 2>/dev/null || true)
if echo "$attrs" | grep -q " i "; then
chattr -i "$TARGET" >/dev/null 2>&1 || true
fi
if echo "$attrs" | grep -q " a "; then
chattr -a "$TARGET" >/dev/null 2>&1 || true
fi
fi
# Remove protective attributes
remove_host_attrs
# Stop guard services
stop_units_if_present
logger -t "$LOGTAG" "pre: unlocking /etc/hosts (starting)"
echo "$(date -Is) pre-unlock" >>/run/hosts-guard-hook.log 2>/dev/null || true
log_hook "pre" "unlocking(start)"
# Always collapse any existing layers; we'll operate on the plain file
cleanup_mount_stacks
# Collapse any existing mount layers
collapse_mounts
# If someone managed a ro single-layer mount, ensure rw by remounting or collapsing again
# Ensure writable by remounting if still read-only
if is_ro_mount; then
mount -o remount,rw "$TARGET" >/dev/null 2>&1 || cleanup_mount_stacks
mount -o remount,rw "$TARGET" >/dev/null 2>&1 || collapse_mounts
fi
logger -t "$LOGTAG" "pre: unlocking /etc/hosts (done)"
log_hook "pre" "unlocking(done)"
exit 0