Harden brainstorm stop-server stale pid handling

skills/brainstorming/scripts/stop-server.sh

@@ -7,6 +7,8 @@
 # kept so mockups can be reviewed later.
 
 SESSION_DIR="$1"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+SERVER_SCRIPT="${SCRIPT_DIR}/server.cjs"
 
 if [[ -z "$SESSION_DIR" ]]; then
   echo '{"error": "Usage: stop-server.sh <session_dir>"}'
@@ -16,9 +18,333 @@ fi
 STATE_DIR="${SESSION_DIR}/state"
 PID_FILE="${STATE_DIR}/server.pid"
 
+canonical_dir() {
+  local dir="${1//\\//}"
+  if [[ ! -d "$dir" ]]; then
+    printf '%s' "$dir"
+    return
+  fi
+
+  (
+    cd "$dir" || exit 1
+    pwd -W 2>/dev/null || pwd -P
+  )
+}
+
+physical_dir() {
+  local dir="${1//\\//}"
+  if [[ ! -d "$dir" ]]; then
+    printf '%s' "$dir"
+    return
+  fi
+
+  (
+    cd "$dir" || exit 1
+    pwd -P
+  )
+}
+
+same_dir() {
+  local actual="$1"
+  local expected="$2"
+  local actual_canonical
+  local actual_physical
+  local expected_canonical
+  local expected_physical
+
+  actual_canonical="$(canonical_dir "$actual")"
+  actual_physical="$(physical_dir "$actual")"
+  expected_canonical="$(canonical_dir "$expected")"
+  expected_physical="$(physical_dir "$expected")"
+
+  [[ "$actual" == "$expected" ||
+     "$actual" == "$expected_canonical" ||
+     "$actual" == "$expected_physical" ||
+     "$actual_canonical" == "$expected_canonical" ||
+     "$actual_canonical" == "$expected_physical" ||
+     "$actual_physical" == "$expected_canonical" ||
+     "$actual_physical" == "$expected_physical" ]]
+}
+
+canonical_path() {
+  local path="${1//\\//}"
+  local dir
+  local base
+
+  dir="$(dirname "$path")"
+  base="$(basename "$path")"
+  if [[ ! -d "$dir" ]]; then
+    printf '%s' "$path"
+    return
+  fi
+
+  printf '%s/%s' "$(canonical_dir "$dir")" "$base"
+}
+
+physical_path() {
+  local path="${1//\\//}"
+  local dir
+  local base
+
+  dir="$(dirname "$path")"
+  base="$(basename "$path")"
+  if [[ ! -d "$dir" ]]; then
+    printf '%s' "$path"
+    return
+  fi
+
+  printf '%s/%s' "$(physical_dir "$dir")" "$base"
+}
+
+strip_outer_quotes() {
+  local value="$1"
+  value="${value#\"}"
+  value="${value%\"}"
+  printf '%s' "$value"
+}
+
+same_file() {
+  local actual="$1"
+  local expected="$2"
+  local actual_canonical
+  local actual_physical
+  local expected_canonical
+  local expected_physical
+
+  actual_canonical="$(canonical_path "$actual")"
+  actual_physical="$(physical_path "$actual")"
+  expected_canonical="$(canonical_path "$expected")"
+  expected_physical="$(physical_path "$expected")"
+
+  [[ "${actual//\\//}" == "${expected//\\//}" ||
+     "${actual//\\//}" == "$expected_canonical" ||
+     "${actual//\\//}" == "$expected_physical" ||
+     "$actual_canonical" == "$expected_canonical" ||
+     "$actual_canonical" == "$expected_physical" ||
+     "$actual_physical" == "$expected_canonical" ||
+     "$actual_physical" == "$expected_physical" ]]
+}
+
+process_command() {
+  local pid="$1"
+  if [[ -r "/proc/$pid/cmdline" ]]; then
+    tr '\0' ' ' < "/proc/$pid/cmdline"
+    return
+  fi
+  if ps -p "$pid" -o args= >/dev/null 2>&1; then
+    ps -p "$pid" -o args= 2>/dev/null
+    return
+  fi
+  if ps -p "$pid" -o command= >/dev/null 2>&1; then
+    ps -p "$pid" -o command= 2>/dev/null
+    return
+  fi
+  ps -p "$pid" 2>/dev/null | sed -n '2p'
+}
+
+process_environment() {
+  local pid="$1"
+  if [[ -r "/proc/$pid/environ" ]]; then
+    tr '\0' '\n' < "/proc/$pid/environ"
+    return
+  fi
+  if ps eww -p "$pid" >/dev/null 2>&1; then
+    ps eww -p "$pid" 2>/dev/null
+    return
+  fi
+  return 1
+}
+
+process_cwd() {
+  local pid="$1"
+  local cwd
+  if [[ -d "/proc/$pid/cwd" ]]; then
+    canonical_dir "/proc/$pid/cwd"
+    return
+  fi
+  if command -v lsof >/dev/null 2>&1; then
+    cwd="$(lsof -a -p "$pid" -d cwd -Fn 2>/dev/null | sed -n 's/^n//p' | head -1)"
+    if [[ -n "$cwd" ]]; then
+      printf '%s' "$cwd"
+      return
+    fi
+  fi
+  return 1
+}
+
+brainstorm_dir_from_environment() {
+  local env_text="$1"
+  local value
+
+  value="$(printf '%s\n' "$env_text" | sed -n 's/^BRAINSTORM_DIR=//p' | head -1)"
+  if [[ -n "$value" ]]; then
+    printf '%s' "$value"
+    return 0
+  fi
+
+  if [[ "$env_text" =~ (^|[[:space:]])BRAINSTORM_DIR=([^[:space:]]+)($|[[:space:]]) ]]; then
+    printf '%s' "${BASH_REMATCH[2]}"
+    return 0
+  fi
+
+  return 1
+}
+
+server_info_value() {
+  local key="$1"
+  local info_file="${STATE_DIR}/server-info"
+
+  [[ -r "$info_file" ]] || return 1
+  node -e '
+    const fs = require("fs");
+    const key = process.argv[1];
+    const file = process.argv[2];
+    const info = JSON.parse(fs.readFileSync(file, "utf8"));
+    if (info[key] === undefined || info[key] === null) process.exit(1);
+    process.stdout.write(String(info[key]));
+  ' "$key" "$info_file" 2>/dev/null
+}
+
+server_info_owns_pid() {
+  local pid="$1"
+  local session_dir="$2"
+  local port
+  local state_dir
+  local listener_pid
+  local expected_state_dir="${session_dir}/state"
+
+  command -v lsof >/dev/null 2>&1 || return 1
+
+  port="$(server_info_value port)" || return 1
+  state_dir="$(server_info_value state_dir)" || return 1
+  [[ "$port" =~ ^[0-9]+$ ]] || return 1
+  same_dir "$state_dir" "$expected_state_dir" || return 1
+
+  while IFS= read -r listener_pid; do
+    [[ "$listener_pid" == "$pid" ]] && return 0
+  done < <(lsof -nP -iTCP:"$port" -sTCP:LISTEN -t 2>/dev/null | sort -u)
+
+  return 1
+}
+
+resolve_process_path() {
+  local arg="${1//\\//}"
+  local cwd="$2"
+
+  if [[ "$arg" == /* || "$arg" =~ ^[A-Za-z]:/ ]]; then
+    printf '%s' "$arg"
+  else
+    printf '%s/%s' "$cwd" "$arg"
+  fi
+}
+
+command_has_node_entrypoint() {
+  local command="${1//\\//}"
+  local entry="${2//\\//}"
+  local node_name
+
+  for node_name in node node.exe; do
+    [[ "$command" == "$node_name $entry" ||
+       "$command" == "$node_name $entry "* ||
+       "$command" == "$node_name \"$entry\"" ||
+       "$command" == "$node_name \"$entry\" "* ||
+       "$command" == "$node_name '$entry'" ||
+       "$command" == "$node_name '$entry' "* ||
+       "$command" == *" $node_name $entry" ||
+       "$command" == *" $node_name $entry "* ||
+       "$command" == *" $node_name \"$entry\"" ||
+       "$command" == *" $node_name \"$entry\" "* ||
+       "$command" == *" $node_name '$entry'" ||
+       "$command" == *" $node_name '$entry' "* ||
+       "$command" == *"/$node_name $entry" ||
+       "$command" == *"/$node_name $entry "* ||
+       "$command" == *"/$node_name \"$entry\"" ||
+       "$command" == *"/$node_name \"$entry\" "* ||
+       "$command" == *"/$node_name '$entry'" ||
+       "$command" == *"/$node_name '$entry' "* ]] && return 0
+  done
+
+  return 1
+}
+
+process_runs_server_script() {
+  local pid="$1"
+  local argv=()
+  local arg
+  local executable
+  local script_arg
+  local cwd
+  local command
+  local server_canonical
+  local server_physical
+
+  if [[ -r "/proc/$pid/cmdline" ]]; then
+    while IFS= read -r -d '' arg || [[ -n "$arg" ]]; do
+      argv+=("$(strip_outer_quotes "$arg")")
+    done < "/proc/$pid/cmdline"
+
+    [[ ${#argv[@]} -ge 2 ]] || return 1
+    executable="$(basename "${argv[0]//\\//}")"
+    executable="${executable%.exe}"
+    [[ "$executable" == "node" || "$executable" == "nodejs" ]] || return 1
+
+    script_arg="${argv[1]}"
+    [[ "$script_arg" == -* ]] && return 1
+
+    cwd="$(process_cwd "$pid")" || return 1
+    same_file "$(resolve_process_path "$script_arg" "$cwd")" "$SERVER_SCRIPT"
+    return
+  fi
+
+  command="$(process_command "$pid")"
+  server_canonical="$(canonical_path "$SERVER_SCRIPT")"
+  server_physical="$(physical_path "$SERVER_SCRIPT")"
+
+  if command_has_node_entrypoint "$command" "$SERVER_SCRIPT" ||
+     command_has_node_entrypoint "$command" "$server_canonical" ||
+     command_has_node_entrypoint "$command" "$server_physical"; then
+    return 0
+  fi
+
+  command_has_node_entrypoint "$command" "server.cjs" || return 1
+  cwd="$(process_cwd "$pid")" || return 1
+  same_dir "$cwd" "$SCRIPT_DIR"
+}
+
+owns_pid() {
+  local pid="$1"
+  local session_dir="$2"
+  local env
+  local actual_dir
+
+  kill -0 "$pid" 2>/dev/null || return 1
+
+  process_runs_server_script "$pid" || return 1
+
+  if [[ -r "/proc/$pid/environ" ]]; then
+    env="$(tr '\0' '\n' < "/proc/$pid/environ")" || return 1
+    actual_dir="$(brainstorm_dir_from_environment "$env")" || return 1
+    same_dir "$actual_dir" "$session_dir"
+    return
+  fi
+
+  if env="$(process_environment "$pid")" &&
+     actual_dir="$(brainstorm_dir_from_environment "$env")"; then
+    same_dir "$actual_dir" "$session_dir" && return 0
+  fi
+
+  server_info_owns_pid "$pid" "$session_dir"
+}
+
 if [[ -f "$PID_FILE" ]]; then
   pid=$(cat "$PID_FILE")
 
+  if [[ ! "$pid" =~ ^[0-9]+$ ]] || ! owns_pid "$pid" "$SESSION_DIR"; then
+    rm -f "$PID_FILE" "${STATE_DIR}/server.log"
+    echo '{"status": "stale_pid"}'
+    exit 0
+  fi
+
   # Try to stop gracefully, fallback to force if still alive
   kill "$pid" 2>/dev/null || true
 
@@ -32,6 +358,12 @@ if [[ -f "$PID_FILE" ]]; then
 
   # If still running, escalate to SIGKILL
   if kill -0 "$pid" 2>/dev/null; then
+    if ! owns_pid "$pid" "$SESSION_DIR"; then
+      rm -f "$PID_FILE" "${STATE_DIR}/server.log"
+      echo '{"status": "stale_pid"}'
+      exit 0
+    fi
+
     kill -9 "$pid" 2>/dev/null || true
 
     # Give SIGKILL a moment to take effect