Refactor backtunnel-share with cleanup logic, duration-based termination, and improved error handling; introduce backtunnel-share-gui for streamlined GUI-based operation

scripts/backtunnel-share

@@ -5,7 +5,8 @@
 
 # backtunnel-share: Share a folder using reverse SSH for a limited duration
 # Syntax: backtunnel-share /path/to/folder with remoteuser:remotehost for 2h
-# Options: -p|--tunnel-port <PORT>  -l|--local-ssh-port <PORT>  -i|--invite [--invite-mount <PATH>] [--invite-file <FILE>] [--qr]  -h|--help
+# Options: -p|--tunnel-port <PORT>  -l|--local-ssh-port <PORT>
+#          -i|--invite [--invite-mount <PATH>] [--invite-file <FILE>] [--qr]  -h|--help
 
 set -euo pipefail
 
@@ -123,6 +124,7 @@ fi
 # --- deps check ---
 command -v ssh >/dev/null 2>&1 || { echo "ssh not found."; exit 1; }
 command -v timeout >/dev/null 2>&1 || { echo "timeout not found."; exit 1; }
+command -v tail >/dev/null 2>&1 || { echo "tail not found."; exit 1; } # used for --pid wait
 
 echo "⏳ Sharing '${FOLDER}' via reverse SSH:"
 echo "    local sshd port     : ${LOCAL_SSH_PORT}"
@@ -164,9 +166,10 @@ fi
 
 echo "Tip: On the remote side, mount with:"
 echo "     backtunnel-access '${FOLDER}' from ${REMOTE_USER}@${REMOTE_HOST} -p ${TUNNEL_PORT}"
-echo "To stop sharing early: press Ctrl+C here."
+echo "Listener will appear on: ${REMOTE_HOST}:${TUNNEL_PORT} (run access there)."
+echo "To stop sharing early: press Ctrl+C in this window."
 
-# --- optional pre-flight: warn if remote loopback port is already in use (best-effort) ---
+# --- optional pre-flight: warn if remote loopback port already in use (best-effort) ---
 if ssh -o BatchMode=yes -o ConnectTimeout=5 "${REMOTE_USER}@${REMOTE_HOST}" \
      "command -v nc >/dev/null 2>&1 && nc -z 127.0.0.1 ${TUNNEL_PORT}"; then
   echo "⚠️  Port ${TUNNEL_PORT} on remote 127.0.0.1 appears in use; choose another with -p." >&2
@@ -174,19 +177,45 @@ if ssh -o BatchMode=yes -o ConnectTimeout=5 "${REMOTE_USER}@${REMOTE_HOST}" \
   # exit 1
 fi
 
-# Bind reverse to 127.0.0.1 on the REMOTE host (private-by-default).
-# Keepalive so the tunnel drops on dead links.
-# Exit fast if the reverse bind fails (e.g., port in use).
-timeout "$DURATION" ssh -N \
+# --- run ssh in background; trap Ctrl-C/TERM/EXIT to stop it cleanly ---
+SSH_PID=""
+
+# shellcheck disable=SC2317  # cleanup is invoked indirectly via trap
+cleanup() {
+  if [[ -n "${SSH_PID:-}" ]] && kill -0 "$SSH_PID" 2>/dev/null; then
+    echo "⏹️  Stopping share..."
+    kill -TERM "$SSH_PID" 2>/dev/null || true
+    # give ssh a moment to exit gracefully
+    wait "$SSH_PID" 2>/dev/null || true
+  fi
+}
+trap cleanup INT TERM EXIT
+
+# Start reverse-tunnel ssh in background with keepalives + fast-fail on -R bind
+ssh -N \
   -o ExitOnForwardFailure=yes \
   -o ServerAliveInterval=15 \
   -o ServerAliveCountMax=3 \
   -R "${TUNNEL_PORT}:localhost:${LOCAL_SSH_PORT}" \
-  -- "${REMOTE_USER}@${REMOTE_HOST}"
+  -- "${REMOTE_USER}@${REMOTE_HOST}" &
+SSH_PID=$!
 
+# Wait for ssh to exit, but bounded by duration:
+# Use 'timeout … tail --pid=PID -f /dev/null' so we don't need bash -c 'wait "$1"'
+if timeout "$DURATION" tail --pid="$SSH_PID" -f /dev/null; then
+  # ssh exited on its own before timeout
+  exit 0
+else
   rc=$?
   if [[ $rc -eq 124 ]]; then
     echo "⏹️  Sharing ended: reached duration (${DURATION})."
+    # ensure the child is gone
+    if kill -0 "$SSH_PID" 2>/dev/null; then
+      kill -TERM "$SSH_PID" 2>/dev/null || true
+      wait "$SSH_PID" 2>/dev/null || true
+    fi
     exit 0
   fi
+  # other error from timeout/tail
   exit "$rc"
+fi

scripts/backtunnel-share-gui

@@ -0,0 +1,45 @@
+#!/usr/bin/env bash
+
+# Copyright (c) 2025. LUXIM d.o.o., Slovenia - Matjaž Mozetič.
+
+# GUI wrapper for BackTunnel "Share" action (Dolphin service menu)
+# Prompts for parameters via kdialog and launches backtunnel-share in Konsole.
+
+set -euo pipefail
+
+# --- Selection from Dolphin ---
+FOLDER="${1:-}"
+if [[ -z "$FOLDER" ]]; then
+  kdialog --error "No folder selected." || true
+  exit 1
+fi
+
+# --- Defaults ---
+REMOTE_DEFAULT="user@vps.example.com"
+DURATION_DEFAULT="2h"
+TPORT_DEFAULT="2222"
+LPORT_DEFAULT="22"
+INVITE_MOUNT_DEFAULT="/mnt/remote-rssh"
+
+# --- Prompts ---
+REMOTE="$(kdialog --inputbox "Remote (user@host or user:host):" "$REMOTE_DEFAULT")" || exit 1
+DUR="$(kdialog --combobox "Share duration" 30m 2h 6h 1d 2d --editable "$DURATION_DEFAULT")" || exit 1
+TPORT="$(kdialog --inputbox "Tunnel port on remote:" "$TPORT_DEFAULT")" || exit 1
+LPORT="$(kdialog --inputbox "Local SSH port to expose:" "$LPORT_DEFAULT")" || exit 1
+
+INV=""   # explicit if-then; avoids SC2015 ("A && B || C is not if-then-else")
+if kdialog --yesno "Print invite line for chat?"; then
+  INV="-i"
+fi
+
+QR=""
+if kdialog --yesno "Show QR code for the invite?"; then
+  QR="--qr"
+fi
+
+MP="$(kdialog --inputbox "Suggested mount point in invite:" "$INVITE_MOUNT_DEFAULT")" || exit 1
+
+# --- Run share in Konsole (keeps session open) ---
+exec konsole --noclose -e backtunnel-share \
+  "$FOLDER" with "$REMOTE" for "$DUR" \
+  -p "$TPORT" -l "$LPORT" $INV $QR --invite-mount "$MP"

servicemenus/backtunnel_share.desktop

@@ -10,4 +10,4 @@ X-KDE-Priority=TopLevel
 [Desktop Action BackTunnelShare]
 Name=Share via BackTunnel…
 Icon=network-server
-Exec=/bin/bash -lc 'FOLDER="$1"; REMOTE="$(kdialog --inputbox "Remote (user@host or user:host):" "user@vps.example.com")" || exit 1; DUR="$(kdialog --combobox "Share duration" 30m 2h 6h 1d 2d --editable "2h")" || exit 1; TPORT="$(kdialog --inputbox "Tunnel port on remote:" "2222")" || exit 1; LPORT="$(kdialog --inputbox "Local SSH port to expose:" "22")" || exit 1; if kdialog --yesno "Print invite line for chat?"; then INV="-i"; else INV=""; fi; if kdialog --yesno "Show QR code for the invite?"; then QR="--qr"; else QR=""; fi; MP="$(kdialog --inputbox "Suggested mount point in invite:" "/mnt/remote-rssh")" || exit 1; exec konsole --noclose -e backtunnel-share "$FOLDER" with "$REMOTE" for "$DUR" -p "$TPORT" -l "$LPORT" $INV $QR --invite-mount "$MP"' _ %f
+Exec=backtunnel-share-gui %f