Protect install target and add tests

README.md

@@ -52,6 +52,8 @@ sudo iptables-forward
 /usr/local/bin/iptables-forward -> /path/to/IPTables-Management/iptables-forward.sh
 ```
 
+若目标路径已存在且不是当前仓库脚本的符号链接，`install.sh` 会拒绝覆盖；`--uninstall` 也只会删除当前脚本创建的链接，避免误删其它文件。
+
 ## 使用说明
 
 ### 交互模式
@@ -148,6 +150,7 @@ tests/run_all.sh --skip-integration
 测试覆盖：
 
 - `tests/test_cli.sh`：入口脚本与安装脚本帮助输出
+- `tests/test_install.sh`：安装脚本的 install/uninstall 实际行为与误覆盖保护
 - `tests/test_interactive.sh`：交互主菜单的 add/list/delete/save 回归
 - `tests/test_common.sh`：输入校验
 - `tests/test_storage.sh`：规则存储

install.sh

@@ -25,21 +25,38 @@ require_root() {
   fi
 }
 
+target_is_current_link() {
+  [[ -L ${TARGET_BIN} ]] || return 1
+  [[ $(readlink -- "${TARGET_BIN}") == "${SOURCE_SCRIPT}" ]]
+}
+
 install_link() {
   [[ -f ${SOURCE_SCRIPT} ]] || {
     printf '未找到入口脚本: %s\n' "${SOURCE_SCRIPT}" >&2
     exit 1
   }
   mkdir -p "$(dirname -- "${TARGET_BIN}")"
-  ln -sfn "${SOURCE_SCRIPT}" "${TARGET_BIN}"
+  if [[ -e ${TARGET_BIN} || -L ${TARGET_BIN} ]]; then
+    if target_is_current_link; then
+      chmod 755 "${SOURCE_SCRIPT}"
+      printf '链接已存在: %s -> %s\n' "${TARGET_BIN}" "${SOURCE_SCRIPT}"
+      return 0
+    fi
+    printf '目标已存在且不是当前脚本的链接，拒绝覆盖: %s\n' "${TARGET_BIN}" >&2
+    exit 1
+  fi
+  ln -s "${SOURCE_SCRIPT}" "${TARGET_BIN}"
   chmod 755 "${SOURCE_SCRIPT}"
   printf '已创建链接: %s -> %s\n' "${TARGET_BIN}" "${SOURCE_SCRIPT}"
 }
 
 uninstall_link() {
-  if [[ -L ${TARGET_BIN} || -e ${TARGET_BIN} ]]; then
+  if target_is_current_link; then
     rm -f "${TARGET_BIN}"
     printf '已删除链接: %s\n' "${TARGET_BIN}"
+  elif [[ -L ${TARGET_BIN} || -e ${TARGET_BIN} ]]; then
+    printf '目标不是当前脚本创建的链接，拒绝删除: %s\n' "${TARGET_BIN}" >&2
+    exit 1
   else
     printf '未发现已安装链接: %s\n' "${TARGET_BIN}"
   fi

tests/run_all.sh

@@ -24,6 +24,7 @@ run_test() {
 
 run_test "${ROOT_DIR}/tests/test_common.sh"
 run_test "${ROOT_DIR}/tests/test_cli.sh"
+run_test "${ROOT_DIR}/tests/test_install.sh"
 run_test "${ROOT_DIR}/tests/test_interactive.sh"
 run_test "${ROOT_DIR}/tests/test_storage.sh"
 run_test "${ROOT_DIR}/tests/test_env_check.sh"

tests/test_install.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)
+# shellcheck source=tests/lib/assert.sh
+source "${ROOT_DIR}/tests/lib/assert.sh"
+
+maybe_enter_namespace() {
+  if (( EUID == 0 )); then
+    return 0
+  fi
+
+  if [[ ${IPF_IN_NAMESPACE:-0} == 1 ]]; then
+    return 0
+  fi
+
+  if command -v unshare >/dev/null 2>&1 && unshare -Ur true >/dev/null 2>&1; then
+    exec unshare -Ur env IPF_IN_NAMESPACE=1 bash "$0"
+  fi
+
+  printf 'SKIP: 安装测试需要 root 或可用的 unshare。\n'
+  exit 0
+}
+
+status_of() {
+  set +e
+  "$@" >/dev/null 2>&1
+  local rc=$?
+  set -e
+  printf '%s\n' "${rc}"
+}
+
+maybe_enter_namespace
+
+TMP_DIR=$(mktemp -d)
+trap 'rm -rf "${TMP_DIR}"' EXIT
+
+TARGET_BIN="${TMP_DIR}/bin/iptables-forward"
+OTHER_TARGET="${TMP_DIR}/bin/not-ours"
+SOURCE_SCRIPT="${ROOT_DIR}/iptables-forward.sh"
+
+install_output=$(INSTALL_TARGET="${TARGET_BIN}" "${ROOT_DIR}/install.sh")
+assert_contains "${install_output}" '已创建链接:' 'install should create symlink on first run'
+[[ -L ${TARGET_BIN} ]] || fail 'install should create a symlink'
+assert_eq "${SOURCE_SCRIPT}" "$(readlink -- "${TARGET_BIN}")" 'install should link to project entry script'
+
+install_output=$(INSTALL_TARGET="${TARGET_BIN}" "${ROOT_DIR}/install.sh")
+assert_contains "${install_output}" '链接已存在:' 'install should be idempotent for existing project link'
+
+printf 'keep-me\n' >"${OTHER_TARGET}"
+assert_status '1' "$(status_of env INSTALL_TARGET="${OTHER_TARGET}" "${ROOT_DIR}/install.sh")" 'install should refuse to overwrite non-project target'
+assert_eq 'keep-me' "$(cat "${OTHER_TARGET}")" 'install refusal should keep existing target untouched'
+
+uninstall_output=$(INSTALL_TARGET="${TARGET_BIN}" "${ROOT_DIR}/install.sh" --uninstall)
+assert_contains "${uninstall_output}" '已删除链接:' 'uninstall should remove project symlink'
+[[ ! -e ${TARGET_BIN} && ! -L ${TARGET_BIN} ]] || fail 'uninstall should remove installed symlink'
+
+assert_status '1' "$(status_of env INSTALL_TARGET="${OTHER_TARGET}" "${ROOT_DIR}/install.sh" --uninstall)" 'uninstall should refuse to delete non-project target'
+assert_eq 'keep-me' "$(cat "${OTHER_TARGET}")" 'uninstall refusal should keep existing target untouched'
+
+pass 'test_install.sh'