Installer for Squeezebox Radio Wifi Watchdog

install_wifi_watchdog.sh

#!/bin/sh
#
# WiFi Watchdog Installer / Updater / Uninstaller
#
# Usage:
#   Install/Update: ./install_wifi_watchdog.sh <TARGET_IP> [INTERVAL_MINUTES]
#   Uninstall:      ./install_wifi_watchdog.sh uninstall
#
# Examples:
#   ./install_wifi_watchdog.sh 192.168.2.1
#   ./install_wifi_watchdog.sh 192.168.2.1 15
#   ./install_wifi_watchdog.sh uninstall
#

# Configuration
INSTALL_DIR="/root"
SCRIPT_NAME="wifi_watchdog.sh"
FULL_PATH="$INSTALL_DIR/$SCRIPT_NAME"
LOG_FILE="/var/log/wifi_watchdog"
STATE_DIR="/var/lib/wifi_watchdog"

# --- UNINSTALL MODE ---
if [ "$1" = "uninstall" ]; then
    echo "Uninstalling WiFi Watchdog..."

    # 1. Remove from Cron
    if crontab -l 2>/dev/null | grep -F "$FULL_PATH" >/dev/null; then
        TEMP_CRON=$(mktemp)
        crontab -l 2>/dev/null | grep -Fv "$FULL_PATH" > "$TEMP_CRON"
        crontab "$TEMP_CRON"
        rm "$TEMP_CRON"
        echo " - Cron job removed."
    else
        echo " - No cron job found."
    fi

    # 2. Delete Script
    if [ -f "$FULL_PATH" ]; then
        rm -f "$FULL_PATH"
        echo " - Script deleted: $FULL_PATH"
    else
        echo " - Script not found."
    fi

    # 3. Cleanup Logs and State
    rm -f "${LOG_FILE}"* 2>/dev/null
    rm -rf "$STATE_DIR" 2>/dev/null
    echo " - Logs and state files cleaned up."

    echo "Uninstallation complete."
    exit 0
fi

# --- INSTALL / UPDATE MODE ---

TARGET_IP="$1"
INTERVAL="${2:-10}" # Default to 10 minutes

if [ -z "$TARGET_IP" ]; then
    echo "Error: You must provide a target IP address or 'uninstall'."
    echo "Usage: $0 <IP_TO_PING> [MINUTES]"
    echo "       $0 uninstall"
    exit 1
fi

# Cron Schedule: */X * * * *
CRON_JOB="*/$INTERVAL * * * * $FULL_PATH"

echo "Starting installation... (v1.5.0)"
echo "Target IP: $TARGET_IP"
echo "Run Frequency: Every $INTERVAL minutes"

# 1. Stop any running instances
killall "$SCRIPT_NAME" 2>/dev/null

# 2. Generate the Script
echo "Generating script at $FULL_PATH..."

# --- WRITE PART A (Dynamic Config) ---
cat << EOF > "$FULL_PATH"
#!/bin/sh
# Flag file indicating the watchdog ran
touch /tmp/wifi_watchdog_check.flag
# --- Configuration ---
# Target IP to ping (Injected by installer)
TARGET="$TARGET_IP"
EOF

# --- WRITE PART B (Static Logic) ---
cat << 'EOF' >> "$FULL_PATH"
# Number of retries before declaring failure
MAX_RETRIES=5
# Pause between attempts (in seconds)
SLEEP_TIME=5
# Timeout for RestartNetwork in seconds (detects driver hang)
RESTART_TIMEOUT=120
# Log tag for syslog
TAG="WiFi_Watchdog"
# Paths
LOG_FILE="/var/log/wifi_watchdog"
STATE_DIR="/var/lib/wifi_watchdog"
STATE_FILE="$STATE_DIR/state"
# Log Rotation Config (Size in bytes: 51200 = 50KB)
MAX_LOG_SIZE=51200
# ---------------------
# Ensure state directory exists
if [ ! -d "$STATE_DIR" ]; then
    mkdir -p "$STATE_DIR"
fi
# --- Log Rotation Logic ---
if [ -f "$LOG_FILE" ]; then
    FILE_SIZE=$(wc -c < "$LOG_FILE")   
    if [ "$FILE_SIZE" -ge "$MAX_LOG_SIZE" ]; then
        mv "$LOG_FILE" "$LOG_FILE.0"
        TIMESTAMP=$(date "+%Y-%m-%d %H:%M:%S")
        echo "$TIMESTAMP - $TAG: Log rotated (limit ${MAX_LOG_SIZE} bytes reached)." > "$LOG_FILE"
    fi
fi

# Attempt to extract hostname
HOSTNAME_FILE="/etc/hostname"
if [ -f "$HOSTNAME_FILE" ]; then
    HOSTNAME=$(cat "$HOSTNAME_FILE")
fi
if [ -z "$HOSTNAME" ]; then HOSTNAME="SqueezeboxRadio"; fi

# Function: Log to syslog and file
log_event() {
    MSG="$1"
    TIMESTAMP=$(date "+%Y-%m-%d %H:%M:%S")
    logger -t "$TAG" "$MSG"
    echo "$TIMESTAMP - $TAG: $MSG" >> "$LOG_FILE"
}
# Function: Action to take on new failure
RestartNetwork() {
    log_event "Action Triggered: Restarting network services..."
    if [ -x /etc/init.d/wlan ]; then /etc/init.d/wlan stop; fi
    killall udhcpc 2>/dev/null
    sleep 5
    if [ -x /etc/init.d/wlan ]; then /etc/init.d/wlan start; fi
    sleep 5
    
    log_event "Restarting DHCP client..."
    udhcpc -R -a -p/var/run/udhcpc.eth1.pid -b --syslog -ieth1 -H "$HOSTNAME" -s/etc/network/udhcpc_action
    log_event "Network restart sequence finished."
}
# Function: Check connection
check_connection() {
    ping -c 1 "$TARGET" > /dev/null 2>&1
    return $?
}
# --- Main Logic ---
if check_connection; then
    CURRENT_STATUS="OK"
else
    # Initial check failed, entering retry loop
    count=0
    CURRENT_STATUS="FAIL"
    while [ "$count" -lt "$MAX_RETRIES" ]; do
        sleep "$SLEEP_TIME"
        if check_connection; then
            CURRENT_STATUS="OK"
            break
        fi
        count=$((count + 1))
    done
fi
if [ -f "$STATE_FILE" ]; then
    PREV_STATUS=$(cat "$STATE_FILE")
else
    PREV_STATUS="OK"
fi
if [ "$CURRENT_STATUS" != "$PREV_STATUS" ]; then
    # State HAS Changed
    echo "$CURRENT_STATUS" > "$STATE_FILE"
    
    if [ "$CURRENT_STATUS" = "FAIL" ]; then
        log_event "State Change: OK -> FAIL. Connection lost after retries."
        sync
        
        # --- HANG DETECTION WRAPPER START ---
        # Run RestartNetwork in background subshell
        RestartNetwork &
        PID=$!
        
        # Watchdog Loop
        WAITED=0
        FINISHED=0
        while [ "$WAITED" -lt "$RESTART_TIMEOUT" ]; do
            # Check if PID is still running (signal 0 check)
            if ! kill -0 "$PID" 2>/dev/null; then
                FINISHED=1
                break
            fi
            sleep 1
            WAITED=$((WAITED + 1))
        done
        
        if [ "$FINISHED" -eq 0 ]; then
            log_event "CRITICAL: RestartNetwork hung for ${RESTART_TIMEOUT}s (Driver freeze). Force REBOOTING."
            kill -9 "$PID" 2>/dev/null
            sync
            /sbin/reboot
            exit 1
        fi
        # --- HANG DETECTION WRAPPER END ---
        
        log_event "Waiting 15s for network to settle..."
        sleep 15
        
        if check_connection; then
            log_event "Network restart SUCCESSFUL."
            # BUGFIX: Network is fixed. Write OK to disk so a FUTURE failure is detected.
            echo "OK" > "$STATE_FILE"
        else
            log_event "Network restart FAILED. REBOOTING system."
            sync
            /sbin/reboot
        fi
    elif [ "$CURRENT_STATUS" = "OK" ]; then
        log_event "State Change: FAIL -> OK. Connection restored."
    fi
else
    log_event "Status did not change: $CURRENT_STATUS"
    if [ "$CURRENT_STATUS" = "FAIL" ]; then
        log_event "Persistent Failure: Connection still down."
        # No Reboot here. We already tried once (or hung once).
        # If that didn't work, we accept defeat to prevent loops.
    fi
fi
EOF

# 3. Set Permissions
chmod +x "$FULL_PATH"

# 4. Update Cron
echo "Updating cron job..."

# Clean up OLD jobs first to avoid duplicates or multiple schedules
TEMP_CRON=$(mktemp)
crontab -l 2>/dev/null | grep -Fv "$FULL_PATH" > "$TEMP_CRON"

# Add NEW job
echo "$CRON_JOB" >> "$TEMP_CRON"

# Install new cron file
crontab "$TEMP_CRON"
rm "$TEMP_CRON"

echo "Success! Script installed."
echo "Config: Pinging $TARGET_IP every $INTERVAL minutes."

I don’t think that getting the hostname from SlimDiscovery.lua is a good idea. There is a good chance that this name is incompatible with DNS, and the firmware doesn’t use this name anyway. Simple example: what happens if this name contains a space ?

I would suggest just using the name in /etc/hostname, with a fallback to SqueezeboxRadio if, for some unknown reason, the hostname file has disappeared.

Yes, good point. That logic comes from wlanpoke:
https://github.com/PomDev2/wlanpoke/blob/main/wlanpoke.sh#L79

But I agree the name maybe does not comply to valid DNS names. Using /etc/hostname is an option. But I kinda like that feature that the devices appear with invidual names in the router. Using hostname might lead to every device being just SqueezeboxRadio. Removing all non-alphanumeric characters from the SlimDiscovery.lua thing would also be an option.

But, I guess no point in reinventing the wheel here. The script should imo replicate what the vanilla Radio code is doing which is probably to just use /etc/hostname (at least my Fritzbox reports the original device name to be SqueezeboxRadio).
So, I will change it to that.

It looks as if revision 9 is handling the case where wlan stop just hangs. I was going to point this out, but now I don’t have to !

I have observed this occasionally. For some reason it seems that unloading the module just doesn’t work. I don’t know why.

Yes, I was greeted this morning my by radio in the bathroom with a red symbol. After connecting wired LAN, the log suggested that the watchdog script stopped running and never finished (while the process was gone also). So, I added that timeout. Let's see if this is the last quirk ;)