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SSH Idle Session Kicker
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| #!/usr/bin/env bash | |
| ### | |
| # | |
| # SSH Inactive Session Killer | |
| # | |
| ### | |
| # Set idle time in hours - default is 12 | |
| idle_time="12" | |
| # Where to store session file for logging - default is /var/ssh-session | |
| session_directory="/var/ssh-session" | |
| ############# | |
| # If idle_time is left empty, set to default of 12 hours | |
| if [[ -z $idle_time ]]; then | |
| idle_time="12" | |
| fi | |
| # If session directory is left empty, set to default of /var/ssh-session | |
| if [[ -z $session_directory ]]; then | |
| session_directory="/var/ssh-session" | |
| fi | |
| # Exit on script error - https://vaneyckt.io/posts/safer_bash_scripts_with_set_euxo_pipefail/ | |
| set -uo pipefail | |
| # Warning and disconnect timing variables in hours | |
| warning_time=$( date -d "$((idle_time - 1)) hours ago" +%s ) | |
| disconnect_time=$(date -d "$idle_time hours ago" +%s) | |
| # Create the sessions directory | |
| if [ ! -d "$session_directory" ]; then | |
| mkdir -p "$session_directory" | |
| fi | |
| # Create arrays from new lines | |
| IFS=$'\n'; | |
| # Function to create array of user session info | |
| user_info() { | |
| who -s | awk '{ print $2 }' | (cd /dev && xargs stat -c '%n %U %X') | awk '{print $1" "$2" "$3}' | grep -v "root|grep" | sort -k 3,3 | |
| } | |
| user_sessions=$(user_info) | |
| # Remove non-idle session files | |
| for f in "$session_directory"/*; do | |
| # Check that this is definitely a file | |
| test -f "$f" || continue | |
| # Create reusable variables for checking session and idle time for arithmetic later | |
| session_check=$(echo "${user_sessions[*]}" | grep "pts/${f##*/}") | |
| session_idle_time=$(echo "${user_sessions[*]}" | grep "pts/${f##*/}" | awk '{print $3}') | |
| # Check if the file exists but there's no longer a session | |
| if [[ -z $session_check ]]; then | |
| rm "$f" | |
| echo "pts/${f##*/} no longer connected, removing session file" | |
| continue | |
| # Check if the file exists, but is no longer an inactive session | |
| elif [[ ! -z $session_check ]] && [[ $session_idle_time > $warning_time ]]; then | |
| rm "$f" | |
| echo "pts/${f##*/} no longer an inactive session, removing session file" | |
| continue | |
| fi | |
| done | |
| # Loop through the current connected users | |
| for i in ${user_sessions[*]}; do | |
| # Create pts, user and session variables from the connected user data | |
| pts=$(echo "$i" | awk '{print $1}' | cut -d '/' -f2) | |
| user=$(echo "$i" | awk '{print $2}') | |
| session=$(echo "$i" | awk '{print $3}') | |
| # If the session is idle for over the idle cut off time | |
| if [[ $session < $warning_time ]]; then | |
| # If the session file doesn't exist, create it and warn the user that they will be disconnected | |
| if [[ ! -f "$session_directory/$pts" ]]; then | |
| touch "$session_directory/$pts" | |
| echo "Hi $user. Your SSH session has been inactive for $((idle_time - 1)) hours, it will be closed in 1 hour at $(date -d '1 hour') if no activity is detected." | write "$user" "pts/$pts" | |
| continue | |
| # If the session file exists, check it hasn't been there for the idle cut off time | |
| # Kill the session if over idle cut off time | |
| elif [[ -f "$session_directory/$pts" && $session < $disconnect_time ]]; then | |
| pkill -9 -t "pts/$pts" | |
| rm "$session_directory/$pts" | |
| fi | |
| fi | |
| done |
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