ssh-fwd : prendre en compte les redirections en dehors d'un control

master

bin/ssh-fwd

@@ -1,68 +1,73 @@
 #!/bin/bash
 
-# Alias si le terminal est kitty
-if [ "$TERM" = xterm-kitty ]; then
-    ssh=(kitty +kitten ssh)
-else
-    ssh=(ssh)
-fi
+step() {
+    printf '\033[1;32m*\033[0m \033[1m%s...\033[0m\n' "$*"
+}
 
-# Variables
-declare -a args
-
-# Foncitons
 error() {
-    >&2 printf '\033[1;31m%s\033[0m \033[1m%s\033[0m\n' ERROR: "$*"
+    >&2 printf '\033[1;31mERROR:\033[0m \033[1m%s\033[0m\n' "$error"
+    return "$1"
 }
 
-help() {
-    local name
-    name="$(basename "$0")"
-    cat << EOF
-${name}: utilisation:
-    ${name} SERVEUR PORT_LOCAL PORT_DISTANT [CIBLE] [-- ARGUMENTS_SSH...]
-EOF
+error_null_arg() {
+    local error
+    error="Argument \"${arg_name}\" can't be null"
+    error 1
 }
 
-error_help() {
-    error "Invalid usage"
-    >&2 help
-    exit 1
+# Lancer la redirection SSH
+start_forwarding() {
+    ssh \
+        -f -N \
+        -L "${local_port}:${target}:${distant_port}" \
+        "$@" \
+        "$ssh_host"
 }
 
-requested_port_bridge_pid() {
-    lsof -nP -i TCP -s TCP:LISTEN | awk '($1 == "ssh" && $9 ~ /.*:'"${1}"'/) { print $2 }' | uniq | head -n 1
+show_redirection_info() {
+    lsof -i -P -n | awk '($1 == "ssh" && $10 == "(LISTEN)" && $9 ~ /.*:'"${local_port}"'/) { print }'
 }
 
-# Analyser les arguments
-while [ -n "$1" ]; do
-    case "$1" in
-        --)
-            shift
-            break
-            ;;
-        *)
-            args+=("$1")
-            shift
-            ;;
-    esac
-done
+get_ssh_pid() {
+    show_redirection_info | awk '{ print $2 }' | sort | uniq
+}
 
-# Il doit y avoir au moins 3 arguments dans le tableau
-if [ "${#args[@]}" -lt 3 ]; then
-    error_help
+# Supprimer la redirection SSH
+stop_forwarding() {
+    start_forwarding -O cancel
+    if [ "$?" -eq 255 ]; then
+        echo "Okay then, brutally killing SSH..."
+        kill "$(get_ssh_pid)"
+    fi
+}
+
+# Retourner 0 si le port de la redirection est déjà utilisé par SSH
+is_forwarding_active() {
+    [ -n "$(show_redirection_info)" ]
+}
+
+# Parser les variables
+trap error_null_arg EXIT
+set -e
+
+arg_name='SSH host'    ; ssh_host="$1"    ; shift
+arg_name='local port'  ; local_port="$1"  ; shift
+arg_name='distant port'; distant_port="$1"; shift
+trap - EXIT
+unset arg_name
+
+if [ -n "$1" ]
+    then target="$1"
+    else target=localhost
 fi
 
-pid="$(requested_port_bridge_pid "${args[1]}")"
-if [ -z "$pid" ]; then
-    exec "${ssh[@]}" \
-        -f \
-        -N \
-        -L "${args[1]}:${args[3]:-localhost}:${args[2]}" \
-        "${args[0]}" \
-        "$@"
+set +e
+
+# Branchement principal
+if ! is_forwarding_active; then
+    step "Starting the redirection"
+    start_forwarding
 else
-    echo "Suppression de la redirection..."
-    kill "$pid"
+    step "Stopping the redirection"
+    stop_forwarding
 fi
-