cmake可见性和AppArmor示例
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AppArmor/demo1/.gitignore
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AppArmor/demo1/README.md
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# AppArmor 入门 Demo（demo1）技术说明
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> 环境：Ubuntu 24.04 x86_64（阿里云 ECS），内核 6.8.0-124-generic，
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> AppArmor parser 4.0.1，profile ABI 4.0。
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> 运行日期：2026-09-03，最终报告见同目录 `report.txt`。
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## 1. Demo 目标
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用一个最小可复现的例子演示 AppArmor（Linux 内核的强制访问控制 / MAC 模块）最核心的三个行为：
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| # | 场景 | 预期 |
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|---|------|------|
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| 1 | 访问 profile 中**显式允许**的路径 | 放行 |
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| 2 | 访问 profile 中 `deny` 显式禁止的路径 | **静默拒绝**（EACCES，无审计日志） |
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| 3 | 访问 profile 中**完全没有提及**的路径 | 拒绝 + 内核记录 `DENIED` 审计日志 |
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同时覆盖两种可执行体形态：
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- **ELF 二进制**（`demo_app.c` 编译出的 `demo_app`）—— profile 直接 attach 到二进制路径；
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- **Shell 脚本**（`demo_shell.sh`）—— AppArmor 不认识"脚本"，attach 的是**解释器**，转场（transition）发生在 exec `/bin/bash` 时。
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## 2. 文件清单
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```
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demo1/
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├── demo_app.c # C 测试程序：3 个文件访问探针
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├── demo_shell.sh # bash 测试脚本：3 个同类探针
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├── profile.elf # demo_app 的 AppArmor profile
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├── profile.script # demo_shell.sh 的 AppArmor profile
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├── run.sh # 一键运行脚本（需 root）
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└── report.txt # 运行产物：完整执行报告
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```
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## 3. 测试程序设计
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`demo_app.c` 与 `demo_shell.sh` 是同一组探针的两种实现：
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```c
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/* 探针1: 白名单 —— profile 允许 rw，应当成功 */
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fopen("/tmp/demo_elf.log", "w");
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/* 探针2: 显式 deny —— deny /etc/shadow r，静默拒绝 */
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fopen("/etc/shadow", "r");
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/* 探针3: 未提及路径 —— 隐式默认拒绝，拒绝并记录 DENIED 日志 */
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fopen("/tmp/demo_forbidden.log", "w");
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```
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三个探针分别命中 AppArmor 白名单规则的"允许"、`deny` 关键字、以及 enforce 模式下的默认拒绝（default deny）。
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## 4. Profile 逐行解读
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### 4.1 `profile.elf`（ELF 二进制）
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```
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abi <abi/4.0>,
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/home/fnzhang/Project/examples/AppArmor/demo1/demo_app flags=(enforce) {
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/home/fnzhang/Project/examples/AppArmor/demo1/demo_app r,
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/lib/** rm,
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/usr/lib/** rm,
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/usr/lib64/** rm,
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/etc/ld.so.cache r,
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/tmp/demo_elf.log rw,
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deny /etc/shadow r,
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}
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```
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| 语法元素 | 含义 |
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|----------|------|
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| `abi <abi/4.0>,` | 声明 profile 所依据的规则 ABI 版本。不写会按 parser 默认（本机 4.0）并可能告警；显式写出可保证规则语义在不同 parser 版本间稳定 |
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| `路径 { ... }` | **匿名 attach 写法**：profile 的 attachment 点就是这段路径本身，进程 exec 该路径时自动套用此 profile，无需 `px` 转场规则 |
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| `flags=(enforce)` | 强制模式：违规即拒绝。对比 `flags=(complain)` 只记日志不拦截（调试用） |
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| `... r,` | `r` = read；文件规则末尾必须有逗号 |
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| `/lib/** rm` | `**` 跨目录通配；`rm` = read + mmap（动态库加载需要 m 权限） |
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| `/etc/ld.so.cache r` | 动态链接器要读的缓存 |
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| `/tmp/demo_elf.log rw` | 探针 1 的白名单 |
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| `deny /etc/shadow r` | 探针 2 的显式拒绝。`deny` 的语义是**无声拒绝且不产生审计日志**——与"没写这条规则时 enforce 模式的默认拒绝（有日志）"是两种不同行为 |
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### 4.2 `profile.script`（Shell 脚本）
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```
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abi <abi/4.0>,
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/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh flags=(enforce) {
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/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh r,
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/bin/bash rm,
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/usr/bin/bash rm,
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...
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/usr/bin/cat rm,
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/tmp/demo_sh.log rw,
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deny /etc/shadow r,
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}
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```
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关键点：
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1. **attach 点是脚本路径，但真正受约束的是解释器进程**。内核 exec 脚本时会切换到 `/bin/bash` 执行；AppArmor 通过脚本头部的 `#!` 识别原始路径，把 profile 转场给 bash。所以：
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- 脚本自身要 `r`（bash 要读它）；
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- `/bin/bash` 要 `rm`（exec 解释器 + mmap）；
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- 脚本里用到的**每个外部命令**（这里是 `cat`）都要单独授权 —— 本 demo 故意**不**给 `cat` 授权 `/etc/shadow` 的读取，让 `cat` 本身可以 exec、但读文件时被拒，从而演示"子进程继承 profile 约束"。
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2. `@{HOME}` 这类**变量需要先 include tunables 才能用**（`#include <tunables/global>`）。本 profile 为保持自包含、便于教学阅读，直接写绝对路径。
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## 5. 运行方式
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```bash
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cd demo1
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chmod +x run.sh demo_shell.sh
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sudo sh run.sh # 必须以 root 运行：装载/卸载 profile 需要特权
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```
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`run.sh` 流程：
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```
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Pre-cleanup ─ apparmor_parser -R 卸载可能残留的旧 profile（幂等，容错）
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Step1 ─ gcc 编译 demo_app.c
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Step2 ─ apparmor_parser -Q 只做语法校验，不装载
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Step3 ─ cp 到 /etc/apparmor.d/ 并 apparmor_parser -r -W 装载（enforce）
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└ 之后 sleep 6 等 audit ratelimit 窗口恢复（见 §7）
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Step4/5 ─ 分别运行 ELF 与脚本，收集 3 个探针的输出
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Step6 ─ aa-status --json 过滤出两个 demo profile 的模式
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Step7 ─ dmesg 过滤 apparmor="DENIED" 的审计记录
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Step8 ─ 卸载 profile、删除 /etc/apparmor.d 下文件、清理 /tmp 探针文件
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```
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## 6. 实测结果（report.txt 摘录）
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**ELF：**
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```
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[probe1] write /tmp/demo_elf.log: ALLOWED ← 白名单放行
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[probe2] open /etc/shadow: Permission denied ← deny 规则拒绝
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[probe3] open /tmp/demo_forbidden.log: Permission denied ← 默认拒绝
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-rw-r--r-- 1 root root 13 /tmp/demo_elf.log ← 允许的写确实落盘
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```
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**脚本：**
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```
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[probe1] write /tmp/demo_sh.log: ALLOWED
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demo_shell.sh: line 8: /usr/bin/cat: Permission denied ← cat 可 exec，读 shadow 被拒
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demo_shell.sh: line 12: /tmp/demo_forbidden.log: Permission denied
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```
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**aa-status：**
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```
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/home/fnzhang/Project/examples/AppArmor/demo1/demo_app: enforce
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/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh: enforce
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```
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**内核审计日志（dmesg）：**
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```
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apparmor="DENIED" operation="mknod" profile="...demo_app"
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name="/tmp/demo_forbidden.log" requested_mask="c" denied_mask="c"
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apparmor="DENIED" operation="exec" profile="...demo_shell.sh"
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name="/usr/bin/cat" requested_mask="x" denied_mask="x"
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```
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注意 DENIED 日志里**只有 probe3 和 `cat` 的事件，没有 `/etc/shadow`**——这正是 `deny` 规则（静默）与默认拒绝（记录日志）的区别在日志层面的直接证据。
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## 7. 踩坑记录（本 demo 调通过程中实际遇到）
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1. **profile 路径写死**：最初 profile 里是 `/home/fnzhang/aa_demo/...`（目录已不存在）。AppArmor 按可执行文件**绝对路径**匹配，路径变了 profile 就完全不生效。改 profile 前先确认二进制的实际路径。
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2. **`profile 名 flags=() 路径 {}` 是非法语法**：flags 必须放在 attachment 之后或用独立 `flags` 行；正确写法是 `路径 flags=(enforce) { ... }` 或 `profile 名 路径 flags=(enforce) { ... }`。非法语法会导致 `systemctl reload apparmor` 整体失败，且报错信息不在终端上、只在 `journalctl -u apparmor` 里。
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3. **`@{HOME}` 未声明报错**：`Found reference to variable HOME, but is never declared`——不带 `#include <tunables/global>` 时必须用绝对路径。
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4. **audit ratelimit 吞掉 DENIED 日志**：`systemctl reload apparmor` 会重载系统全部 200+ 个 profile，产生海量 `STATUS` 审计事件，触发内核 `printk_ratelimit`（`kauditd_printk_skb: xxx callbacks suppressed`），把随后几秒内 demo 真正的 DENIED 事件一并丢弃。解法：
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- 装载/卸载单条 profile 直接用 `apparmor_parser -r -W <file>` / `apparmor_parser -R <file>`，不要 `systemctl reload`；
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- 装载后 `sleep 6`（默认 ratelimit 窗口 5 秒）再触发拒绝。
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5. **`deny` 规则不产生日志是设计行为**：想在日志里看到拒绝事件，应使用"不写规则、靠 enforce 默认拒绝"的方式（demo 的 probe3 即为此设计）。
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6. **脚本 profile 授权对象**：给脚本写 profile 时，脚本内用到的外部命令都要逐个授权；漏掉会在运行时以 `Permission denied` 暴露。
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## 8. 常用命令速查
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```bash
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# 查看 AppArmor 是否启用
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cat /sys/module/apparmor/parameters/enabled # Y
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aa-status # 已装载 profile 列表与模式
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# 装载 / 替换 / 卸载单条 profile（-W 同时写缓存）
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sudo apparmor_parser -r -W /etc/apparmor.d/xxx
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sudo apparmor_parser -R /etc/apparmor.d/xxx
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# 仅语法校验
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apparmor_parser -Q /path/to/profile
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# 查看某个进程当前的 profile
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cat /proc/<pid>/attr/current
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# 查看拒绝日志
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sudo dmesg | grep 'apparmor="DENIED"'
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sudo journalctl -k | grep apparmor
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# 临时把某 profile 切到 complain 模式排查问题
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sudo aa-complain /etc/apparmor.d/xxx
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sudo aa-enforce /etc/apparmor.d/xxx
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```
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## 9. 与 SELinux 的对比（一句话版）
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| | AppArmor | SELinux |
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|---|----------|---------|
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| 标签对象 | **路径**（文件路径 + 进程可执行路径） | inode 标签（label） |
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| 规则粒度 | 每应用一个 profile，白名单易读 | 策略全局统一，类型强制（TE） |
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| 学习成本 | 低，`aa-logprof` 可从日志生成规则 | 高 |
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| 适用发行版 | Ubuntu / Debian / SUSE | RHEL / Fedora / Android |
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两者都是 LSM（Linux Security Module）钩子实现，内核只能启用其一（`CONFIG_LSM` 决定）。
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#define _GNU_SOURCE
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#include <stdio.h>
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#include <unistd.h>
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int main(void)
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{
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/* 探针1: 白名单文件 —— profile 中 /tmp/demo_elf.log rw, 应当成功 */
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FILE* fp = fopen("/tmp/demo_elf.log","w");
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if(fp){
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fprintf(fp,"elf write ok\n");
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fclose(fp);
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printf("[probe1] write /tmp/demo_elf.log: ALLOWED\n");
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}else{
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perror("[probe1] open /tmp/demo_elf.log");
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}
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/* 探针2: 显式 deny 规则 —— deny /etc/shadow r, 静默拒绝, 不产生审计日志 */
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fp = fopen("/etc/shadow","r");
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if(fp){
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printf("[probe2] read /etc/shadow: ALLOWED (unexpected!)\n");
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fclose(fp);
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}else{
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perror("[probe2] open /etc/shadow");
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}
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/* 探针3: 未在 profile 中列出的路径 —— 隐式默认拒绝(enforce), 拒绝并记录 DENIED 日志 */
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fp = fopen("/tmp/demo_forbidden.log","w");
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if(fp){
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fprintf(fp,"should not be here\n");
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fclose(fp);
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printf("[probe3] write /tmp/demo_forbidden.log: ALLOWED (unexpected!)\n");
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}else{
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perror("[probe3] open /tmp/demo_forbidden.log");
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}
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return 0;
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}
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14
AppArmor/demo1/demo_shell.sh
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AppArmor/demo1/demo_shell.sh
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#!/bin/bash
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# 探针1: 白名单文件 —— profile 中 /tmp/demo_sh.log rw, 应当成功
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echo "[probe1] shell try write /tmp/demo_sh.log"
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echo "shell write ok" > /tmp/demo_sh.log && echo "[probe1] write /tmp/demo_sh.log: ALLOWED"
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# 探针2: 显式 deny —— deny /etc/shadow r, 静默拒绝
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echo "[probe2] shell try read /etc/shadow"
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cat /etc/shadow && echo "[probe2] read /etc/shadow: ALLOWED (unexpected!)"
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# 探针3: 未列出的路径 —— 隐式默认拒绝, 记录 DENIED 日志
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echo "[probe3] shell try write /tmp/demo_forbidden.log"
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echo "should not be here" > /tmp/demo_forbidden.log && echo "[probe3] write /tmp/demo_forbidden.log: ALLOWED (unexpected!)"
|
||||||
|
|
||||||
|
exit 0
|
||||||
11
AppArmor/demo1/profile.elf
Normal file
11
AppArmor/demo1/profile.elf
Normal file
|
|
@ -0,0 +1,11 @@
|
||||||
|
abi <abi/4.0>,
|
||||||
|
|
||||||
|
/home/fnzhang/Project/examples/AppArmor/demo1/demo_app flags=(enforce) {
|
||||||
|
/home/fnzhang/Project/examples/AppArmor/demo1/demo_app r,
|
||||||
|
/lib/** rm,
|
||||||
|
/usr/lib/** rm,
|
||||||
|
/usr/lib64/** rm,
|
||||||
|
/etc/ld.so.cache r,
|
||||||
|
/tmp/demo_elf.log rw,
|
||||||
|
deny /etc/shadow r,
|
||||||
|
}
|
||||||
27
AppArmor/demo1/profile.script
Normal file
27
AppArmor/demo1/profile.script
Normal file
|
|
@ -0,0 +1,27 @@
|
||||||
|
abi <abi/4.0>,
|
||||||
|
|
||||||
|
/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh flags=(enforce) {
|
||||||
|
# 解释器与自身
|
||||||
|
/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh r,
|
||||||
|
/bin/bash rm,
|
||||||
|
/usr/bin/bash rm,
|
||||||
|
/etc/ld.so.cache r,
|
||||||
|
/lib/** rm,
|
||||||
|
/usr/lib/** rm,
|
||||||
|
/usr/lib64/** rm,
|
||||||
|
|
||||||
|
# bash 运行所需的基础文件
|
||||||
|
/etc/bash.bashrc r,
|
||||||
|
/etc/profile r,
|
||||||
|
/etc/profile.d/** r,
|
||||||
|
/home/fnzhang/.bashrc r,
|
||||||
|
/home/fnzhang/.profile r,
|
||||||
|
/dev/tty rw,
|
||||||
|
|
||||||
|
# 外部命令
|
||||||
|
/usr/bin/cat rm,
|
||||||
|
|
||||||
|
# 允许写目标文件、拒绝读 shadow
|
||||||
|
/tmp/demo_sh.log rw,
|
||||||
|
deny /etc/shadow r,
|
||||||
|
}
|
||||||
46
AppArmor/demo1/report.txt
Normal file
46
AppArmor/demo1/report.txt
Normal file
|
|
@ -0,0 +1,46 @@
|
||||||
|
|
||||||
|
===== Pre‑cleanup: remove leftover profile =====
|
||||||
|
pre‑cleanup done
|
||||||
|
|
||||||
|
===== Step1 compile C elf =====
|
||||||
|
compile done: /home/fnzhang/Project/examples/AppArmor/demo1/demo_app
|
||||||
|
|
||||||
|
===== Step2 validate profile syntax =====
|
||||||
|
profile.elf syntax OK
|
||||||
|
profile.script syntax OK
|
||||||
|
|
||||||
|
===== Step3 install profile =====
|
||||||
|
profile installed & enforce enabled
|
||||||
|
|
||||||
|
===== Step4 run elf demo_app =====
|
||||||
|
[probe2] open /etc/shadow: Permission denied
|
||||||
|
[probe3] open /tmp/demo_forbidden.log: Permission denied
|
||||||
|
[probe1] write /tmp/demo_elf.log: ALLOWED
|
||||||
|
-- verify /tmp/demo_elf.log exists (allowed write):
|
||||||
|
-rw-r--r-- 1 root root 13 Sep 3 09:48 /tmp/demo_elf.log
|
||||||
|
|
||||||
|
===== Step5 run shell script =====
|
||||||
|
[probe1] shell try write /tmp/demo_sh.log
|
||||||
|
[probe1] write /tmp/demo_sh.log: ALLOWED
|
||||||
|
[probe2] shell try read /etc/shadow
|
||||||
|
/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh: line 8: /usr/bin/cat: Permission denied
|
||||||
|
[probe3] shell try write /tmp/demo_forbidden.log
|
||||||
|
/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh: line 12: /tmp/demo_forbidden.log: Permission denied
|
||||||
|
-- verify /tmp/demo_sh.log exists (allowed write):
|
||||||
|
-rw-r--r-- 1 root root 15 Sep 3 09:48 /tmp/demo_sh.log
|
||||||
|
|
||||||
|
===== Step6 aa-status snapshot =====
|
||||||
|
/home/fnzhang/Project/examples/AppArmor/demo1/demo_app: enforce
|
||||||
|
/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh: enforce
|
||||||
|
|
||||||
|
===== Step7 AppArmor DENIED logs =====
|
||||||
|
[397463.022144] audit: type=1400 audit(1788400106.547:1352): apparmor="DENIED" operation="mknod" class="file" profile="/home/fnzhang/Project/examples/AppArmor/demo1/demo_app" name="/tmp/demo_forbidden.log" pid=382024 comm="demo_app" requested_mask="c" denied_mask="c" fsuid=0 ouid=0
|
||||||
|
[397463.026257] audit: type=1400 audit(1788400106.552:1353): apparmor="DENIED" operation="exec" class="file" profile="/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh" name="/usr/bin/cat" pid=382031 comm="demo_shell.sh" requested_mask="x" denied_mask="x" fsuid=0 ouid=0
|
||||||
|
[397463.026325] audit: type=1400 audit(1788400106.552:1354): apparmor="DENIED" operation="open" class="file" profile="/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh" name="/etc/locale.alias" pid=382031 comm="demo_shell.sh" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
|
||||||
|
[397463.026690] audit: type=1400 audit(1788400106.553:1355): apparmor="DENIED" operation="mknod" class="file" profile="/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh" name="/tmp/demo_forbidden.log" pid=382029 comm="demo_shell.sh" requested_mask="c" denied_mask="c" fsuid=0 ouid=0
|
||||||
|
[397463.026706] audit: type=1400 audit(1788400106.553:1356): apparmor="DENIED" operation="open" class="file" profile="/home/fnzhang/Project/examples/AppArmor/demo1/demo_shell.sh" name="/etc/locale.alias" pid=382029 comm="demo_shell.sh" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
|
||||||
|
|
||||||
|
===== Step8 clean resources =====
|
||||||
|
|
||||||
|
========================================
|
||||||
|
Demo finished, report file: /home/fnzhang/Project/examples/AppArmor/demo1/report.txt
|
||||||
123
AppArmor/demo1/run.sh
Executable file
123
AppArmor/demo1/run.sh
Executable file
|
|
@ -0,0 +1,123 @@
|
||||||
|
#!/bin/bash
|
||||||
|
# 运行方法：
|
||||||
|
# step1: chmod +x run.sh demo_shell.sh
|
||||||
|
# step2: sudo sh run.sh
|
||||||
|
set -e
|
||||||
|
|
||||||
|
WORK_DIR=$(cd "$(dirname "$0")" && pwd)
|
||||||
|
cd "${WORK_DIR}"
|
||||||
|
|
||||||
|
if [ "$(id -u)" -ne 0 ];then
|
||||||
|
echo "please run with sudo: sudo sh run.sh"
|
||||||
|
exit 1
|
||||||
|
fi
|
||||||
|
|
||||||
|
ELF_BIN="${WORK_DIR}/demo_app"
|
||||||
|
SCRIPT_FILE="${WORK_DIR}/demo_shell.sh"
|
||||||
|
|
||||||
|
PROFILE_ELF_NAME="home.fnzhang.aa_demo.demo_app"
|
||||||
|
PROFILE_SCRIPT_NAME="home.fnzhang.aa_demo.demo_shell"
|
||||||
|
PROFILE_ELF="/etc/apparmor.d/${PROFILE_ELF_NAME}"
|
||||||
|
PROFILE_SCRIPT="/etc/apparmor.d/${PROFILE_SCRIPT_NAME}"
|
||||||
|
|
||||||
|
REPORT="${WORK_DIR}/report.txt"
|
||||||
|
> "${REPORT}"
|
||||||
|
|
||||||
|
log(){
|
||||||
|
echo "$1"
|
||||||
|
echo "$1" >> "${REPORT}"
|
||||||
|
}
|
||||||
|
|
||||||
|
echo "========================================"
|
||||||
|
echo "AppArmor Demo start, workdir: ${WORK_DIR}"
|
||||||
|
echo "========================================"
|
||||||
|
|
||||||
|
# ========== 【前置清理：解决上次残留冲突】 ==========
|
||||||
|
log ""
|
||||||
|
log "===== Pre‑cleanup: remove leftover profile ====="
|
||||||
|
# 卸载内核中可能残留的旧 profile（-R 按 profile 名卸载）
|
||||||
|
apparmor_parser -R "${PROFILE_ELF}" 2>/dev/null || true
|
||||||
|
apparmor_parser -R "${PROFILE_SCRIPT}" 2>/dev/null || true
|
||||||
|
# 清掉 /etc/apparmor.d 下旧文件（含上次失败残留的错误 profile）
|
||||||
|
rm -f "${PROFILE_ELF}" "${PROFILE_SCRIPT}"
|
||||||
|
# 注意：不使用 systemctl reload apparmor —— 它会重载全部 200+ 个 profile，
|
||||||
|
# 触发内核 printk ratelimit（kauditd callbacks suppressed），
|
||||||
|
# 把随后 demo 真正的 DENIED 审计事件一并丢弃。
|
||||||
|
log "pre‑cleanup done"
|
||||||
|
|
||||||
|
# ========== Step1 compile C elf ==========
|
||||||
|
log ""
|
||||||
|
log "===== Step1 compile C elf ====="
|
||||||
|
gcc "${WORK_DIR}/demo_app.c" -o "${ELF_BIN}"
|
||||||
|
chmod +x "${ELF_BIN}"
|
||||||
|
log "compile done: ${ELF_BIN}"
|
||||||
|
|
||||||
|
# ========== Step2 validate profile syntax ==========
|
||||||
|
log ""
|
||||||
|
log "===== Step2 validate profile syntax ====="
|
||||||
|
apparmor_parser -Q "${WORK_DIR}/profile.elf" && log "profile.elf syntax OK"
|
||||||
|
apparmor_parser -Q "${WORK_DIR}/profile.script" && log "profile.script syntax OK"
|
||||||
|
|
||||||
|
# ========== Step3 install profile ==========
|
||||||
|
log ""
|
||||||
|
log "===== Step3 install profile ====="
|
||||||
|
cp "${WORK_DIR}/profile.elf" "${PROFILE_ELF}"
|
||||||
|
cp "${WORK_DIR}/profile.script" "${PROFILE_SCRIPT}"
|
||||||
|
apparmor_parser -r -W "${PROFILE_ELF}" || { rm -f "${PROFILE_ELF}"; log "ERROR: elf profile load failed"; exit 1; }
|
||||||
|
apparmor_parser -r -W "${PROFILE_SCRIPT}" || { rm -f "${PROFILE_SCRIPT}"; log "ERROR: script profile load failed"; exit 1; }
|
||||||
|
|
||||||
|
log "profile installed & enforce enabled"
|
||||||
|
|
||||||
|
# 等待内核 audit ratelimit 窗口恢复，避免 DENIED 事件被 printk ratelimit 吞掉
|
||||||
|
sleep 6
|
||||||
|
|
||||||
|
# ========== Step4 run elf demo_app ==========
|
||||||
|
log ""
|
||||||
|
log "===== Step4 run elf demo_app ====="
|
||||||
|
rm -f /tmp/demo_elf.log /tmp/demo_forbidden.log
|
||||||
|
"${ELF_BIN}" 2>&1 | tee -a "${REPORT}" || log "(demo_app returned non-zero / was killed - expected)"
|
||||||
|
log "-- verify /tmp/demo_elf.log exists (allowed write):"
|
||||||
|
ls -l /tmp/demo_elf.log 2>&1 | tee -a "${REPORT}"
|
||||||
|
|
||||||
|
# ========== Step5 run shell script ==========
|
||||||
|
log ""
|
||||||
|
log "===== Step5 run shell script ====="
|
||||||
|
rm -f /tmp/demo_sh.log /tmp/demo_forbidden.log
|
||||||
|
"${SCRIPT_FILE}" 2>&1 | tee -a "${REPORT}" || log "(demo_shell.sh returned non-zero / was killed - expected)"
|
||||||
|
log "-- verify /tmp/demo_sh.log exists (allowed write):"
|
||||||
|
ls -l /tmp/demo_sh.log 2>&1 | tee -a "${REPORT}"
|
||||||
|
|
||||||
|
# ========== Step6 aa-status snapshot ==========
|
||||||
|
log ""
|
||||||
|
log "===== Step6 aa-status snapshot ====="
|
||||||
|
aa-status --json 2>/dev/null | python3 -c "
|
||||||
|
import json,sys
|
||||||
|
d = json.load(sys.stdin)
|
||||||
|
for name, mode in sorted(d.get('profiles', {}).items()):
|
||||||
|
if 'demo_app' in name or 'demo_shell' in name:
|
||||||
|
print(f' {name}: {mode}')
|
||||||
|
" | tee -a "${REPORT}"
|
||||||
|
|
||||||
|
# ========== Step7 check deny evidences ==========
|
||||||
|
log ""
|
||||||
|
log "===== Step7 AppArmor DENIED logs ====="
|
||||||
|
# 等 ratelimit 窗口过去再收集（sleep 6 已在 Step3 后做过，这里直接查）
|
||||||
|
dmesg 2>/dev/null | grep -iE 'apparmor=\"DENIED\"' | grep -iE 'demo_app|demo_shell' | tail -10 | tee -a "${REPORT}" \
|
||||||
|
|| journalctl -k -b --no-pager 2>/dev/null | grep -iE 'apparmor=\"DENIED\"' | grep -iE 'demo_app|demo_shell' | tail -10 | tee -a "${REPORT}"
|
||||||
|
if [ -z "$(dmesg 2>/dev/null | grep 'apparmor=\"DENIED\"' | grep -iE 'demo_app|demo_shell')" ]; then
|
||||||
|
log "(提示: 若此处为空, 可能被内核 printk ratelimit 抑制; 显式 deny 规则本身不产生日志)"
|
||||||
|
fi
|
||||||
|
|
||||||
|
# ========== Step8 clean resources ==========
|
||||||
|
log ""
|
||||||
|
log "===== Step8 clean resources ====="
|
||||||
|
apparmor_parser -R "${PROFILE_ELF}" 2>/dev/null || true
|
||||||
|
apparmor_parser -R "${PROFILE_SCRIPT}" 2>/dev/null || true
|
||||||
|
rm -f "${PROFILE_ELF}" "${PROFILE_SCRIPT}"
|
||||||
|
|
||||||
|
rm -f "${ELF_BIN}"
|
||||||
|
rm -f /tmp/demo_elf.log /tmp/demo_sh.log /tmp/demo_forbidden.log
|
||||||
|
|
||||||
|
log ""
|
||||||
|
log "========================================"
|
||||||
|
log "Demo finished, report file: ${REPORT}"
|
||||||
35
cmake/visibility/CMakeLists.txt
Normal file
35
cmake/visibility/CMakeLists.txt
Normal file
|
|
@ -0,0 +1,35 @@
|
||||||
|
cmake_minimum_required(VERSION 3.15)
|
||||||
|
project(visibility_demo CXX)
|
||||||
|
set(CMAKE_CXX_STANDARD 17)
|
||||||
|
|
||||||
|
# ============ color ============
|
||||||
|
add_library(color
|
||||||
|
color/src/color.cpp
|
||||||
|
color/src/rgb_convert.cpp
|
||||||
|
)
|
||||||
|
target_include_directories(color
|
||||||
|
PUBLIC color/public # 对外头目录：用户由此 #include <color/color.h>
|
||||||
|
PRIVATE color/include # 内部头目录：rgb_convert.h 只有 color 自己可见
|
||||||
|
)
|
||||||
|
# 宏出现在公开头文件的 #ifdef 里，决定 API 形状。
|
||||||
|
# 若只标 PRIVATE：color.cpp 编译出了 brightColorCode，
|
||||||
|
# 但用户看到的头文件里该声明被预处理掉 → 库和用户对 API 的理解不一致。
|
||||||
|
target_compile_definitions(color PUBLIC COLOR_ENABLE_BRIGHT)
|
||||||
|
|
||||||
|
# ============ timeutil ============
|
||||||
|
add_library(timeutil timeutil/timeutil.cpp)
|
||||||
|
target_include_directories(timeutil PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/timeutil)
|
||||||
|
|
||||||
|
# ============ printer ============
|
||||||
|
add_library(printer printer/src/printer.cpp)
|
||||||
|
target_include_directories(printer PUBLIC printer/public)
|
||||||
|
target_link_libraries(printer
|
||||||
|
PUBLIC color # printer.h 引用了 color/color.h → 契约的一部分
|
||||||
|
PRIVATE timeutil # 只有 printer.cpp 用 → 实现细节
|
||||||
|
)
|
||||||
|
# 时间格式只影响 printer.cpp 的编译 → PRIVATE，不泄漏、改格式不触发下游重编
|
||||||
|
target_compile_definitions(printer PRIVATE "PRINTER_TIME_FORMAT=\"%H:%M:%S\"")
|
||||||
|
|
||||||
|
# ============ app ============
|
||||||
|
add_executable(app app/main.cpp)
|
||||||
|
target_link_libraries(app PRIVATE printer)
|
||||||
64
cmake/visibility/README.md
Normal file
64
cmake/visibility/README.md
Normal file
|
|
@ -0,0 +1,64 @@
|
||||||
|
# CMake target 可见性 Demo（visibility）
|
||||||
|
|
||||||
|
> 来自博客 `docs/编程/20-接口可见性.md` §5.2「完整 Demo」。
|
||||||
|
> 演示 `target_include_directories` / `target_link_libraries` /
|
||||||
|
> `target_compile_definitions` 上 PUBLIC / PRIVATE / INTERFACE 的传播语义。
|
||||||
|
|
||||||
|
## 运行
|
||||||
|
|
||||||
|
```bash
|
||||||
|
cd cmake/visibility
|
||||||
|
cmake -B build && cmake --build build
|
||||||
|
./build/app
|
||||||
|
```
|
||||||
|
|
||||||
|
预期输出（终端里是彩色的）：
|
||||||
|
|
||||||
|
```
|
||||||
|
10:37:06 hello （绿色）
|
||||||
|
bright red （高亮红 —— PUBLIC 宏 COLOR_ENABLE_BRIGHT 传播到 app 的证据）
|
||||||
|
（没有 "leaked!" —— printer 的 PRIVATE 宏 PRINTER_TIME_FORMAT 被隔离的证据）
|
||||||
|
```
|
||||||
|
|
||||||
|
## 目录结构
|
||||||
|
|
||||||
|
```
|
||||||
|
visibility/
|
||||||
|
├── CMakeLists.txt
|
||||||
|
├── app/
|
||||||
|
│ └── main.cpp # 最终用户，只认识 printer
|
||||||
|
├── color/
|
||||||
|
│ ├── public/color/color.h # 对外 API 头（含 PUBLIC 宏开关 COLOR_ENABLE_BRIGHT）
|
||||||
|
│ ├── include/rgb_convert.h # 内部中间件头，仅库内 .cpp 共享（PRIVATE 目录）
|
||||||
|
│ └── src/{color,rgb_convert}.cpp
|
||||||
|
├── timeutil/
|
||||||
|
│ └── {timeutil.h,timeutil.cpp} # printer 的私有依赖
|
||||||
|
└── printer/
|
||||||
|
├── public/printer/printer.h # 对外 API 头（引用了 color → color 是 PUBLIC 依赖）
|
||||||
|
└── src/printer.cpp
|
||||||
|
```
|
||||||
|
|
||||||
|
依赖与可见性一图流：
|
||||||
|
|
||||||
|
```
|
||||||
|
app ──PRIVATE──> printer ──PUBLIC──> color ✓ app 能 include color.h、感知 COLOR_ENABLE_BRIGHT
|
||||||
|
│ └─(内部) rgb_convert.h ✗ 外部看不见（include/ 是 PRIVATE 目录）
|
||||||
|
└────PRIVATE──> timeutil ✗ app 看不见 timeutil.h
|
||||||
|
└────PRIVATE 宏 PRINTER_TIME_FORMAT ✗ 不泄漏给 app
|
||||||
|
```
|
||||||
|
|
||||||
|
## 验证实验（§5.3）
|
||||||
|
|
||||||
|
| # | 操作 | 实测结果 |
|
||||||
|
|---|------|---------|
|
||||||
|
| 1 | 直接编译运行 | ✅ 输出 bright red，不输出 leaked! |
|
||||||
|
| 2 | main.cpp 加 `#include "rgb_convert.h"` | ✅ `fatal error: rgb_convert.h: No such file or directory` |
|
||||||
|
| 3 | main.cpp 加 `#include "timeutil.h"` | ✅ `fatal error: timeutil.h: No such file or directory` |
|
||||||
|
| 4 | printer 的 `PUBLIC color` 改 `PRIVATE color` | （未跑）printer 自身编译过，app 找不到 color/color.h 报错 |
|
||||||
|
|
||||||
|
## 判断口诀
|
||||||
|
|
||||||
|
打开自己的公开头文件看一眼：
|
||||||
|
- 头文件里 `#include` 了谁 → 那个库 **PUBLIC**
|
||||||
|
- 头文件里 `#ifdef` 了哪个宏（宏影响 API 形状）→ 那个宏 **PUBLIC**
|
||||||
|
- 只在 .cpp 里出现的库/宏/路径 → **PRIVATE**
|
||||||
19
cmake/visibility/app/main.cpp
Normal file
19
cmake/visibility/app/main.cpp
Normal file
|
|
@ -0,0 +1,19 @@
|
||||||
|
#include <printer/printer.h>
|
||||||
|
#include <iostream>
|
||||||
|
|
||||||
|
int main() {
|
||||||
|
Printer p;
|
||||||
|
p.print("hello", Color::Green);
|
||||||
|
|
||||||
|
// COLOR_ENABLE_BRIGHT 是 color 的 PUBLIC 宏，
|
||||||
|
// 顺着 app → printer → color 传播到这里，本分支会被编译进去：
|
||||||
|
#ifdef COLOR_ENABLE_BRIGHT
|
||||||
|
std::cout << brightColorCode(Color::Red) << "bright red" << "\033[0m\n";
|
||||||
|
#endif
|
||||||
|
|
||||||
|
// PRINTER_TIME_FORMAT 是 printer 的 PRIVATE 宏，这里看不见：
|
||||||
|
#ifdef PRINTER_TIME_FORMAT
|
||||||
|
std::cout << "leaked!\n"; // 永远不会被编译进去
|
||||||
|
#endif
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
4
cmake/visibility/color/include/rgb_convert.h
Normal file
4
cmake/visibility/color/include/rgb_convert.h
Normal file
|
|
@ -0,0 +1,4 @@
|
||||||
|
#pragma once
|
||||||
|
// 内部工具：把 RGB 分量拼成 ANSI 真彩色转义码。
|
||||||
|
// 供 color 库内部多个 .cpp 共享，不属于对外 API。
|
||||||
|
const char* rgbToAnsi(int r, int g, int b);
|
||||||
11
cmake/visibility/color/public/color/color.h
Normal file
11
cmake/visibility/color/public/color/color.h
Normal file
|
|
@ -0,0 +1,11 @@
|
||||||
|
#pragma once
|
||||||
|
|
||||||
|
enum class Color { Red, Green, Blue };
|
||||||
|
|
||||||
|
const char* colorCode(Color c);
|
||||||
|
|
||||||
|
// 这个宏出现在公开头文件里，直接决定 API 的形状（多不多一个函数）。
|
||||||
|
// 因此该宏必须对"用 color 的人"同样可见 → CMake 里标 PUBLIC。
|
||||||
|
#ifdef COLOR_ENABLE_BRIGHT
|
||||||
|
const char* brightColorCode(Color c); // 高亮色版本
|
||||||
|
#endif
|
||||||
22
cmake/visibility/color/src/color.cpp
Normal file
22
cmake/visibility/color/src/color.cpp
Normal file
|
|
@ -0,0 +1,22 @@
|
||||||
|
#include "color/color.h"
|
||||||
|
#include "rgb_convert.h" // 内部头：能找到它，靠的是 PRIVATE 的 include/ 搜索路径
|
||||||
|
|
||||||
|
const char* colorCode(Color c) {
|
||||||
|
switch (c) {
|
||||||
|
case Color::Red: return rgbToAnsi(205, 49, 49);
|
||||||
|
case Color::Green: return rgbToAnsi(13, 188, 121);
|
||||||
|
case Color::Blue: return rgbToAnsi(36, 114, 200);
|
||||||
|
}
|
||||||
|
return "";
|
||||||
|
}
|
||||||
|
|
||||||
|
#ifdef COLOR_ENABLE_BRIGHT
|
||||||
|
const char* brightColorCode(Color c) {
|
||||||
|
switch (c) {
|
||||||
|
case Color::Red: return rgbToAnsi(241, 76, 76);
|
||||||
|
case Color::Green: return rgbToAnsi(35, 209, 139);
|
||||||
|
case Color::Blue: return rgbToAnsi(59, 142, 234);
|
||||||
|
}
|
||||||
|
return "";
|
||||||
|
}
|
||||||
|
#endif
|
||||||
8
cmake/visibility/color/src/rgb_convert.cpp
Normal file
8
cmake/visibility/color/src/rgb_convert.cpp
Normal file
|
|
@ -0,0 +1,8 @@
|
||||||
|
#include "rgb_convert.h"
|
||||||
|
#include <cstdio>
|
||||||
|
|
||||||
|
const char* rgbToAnsi(int r, int g, int b) {
|
||||||
|
static char buf[32]; // demo 从简，非线程安全
|
||||||
|
std::snprintf(buf, sizeof(buf), "\033[38;2;%d;%d;%dm", r, g, b);
|
||||||
|
return buf;
|
||||||
|
}
|
||||||
9
cmake/visibility/printer/public/printer/printer.h
Normal file
9
cmake/visibility/printer/public/printer/printer.h
Normal file
|
|
@ -0,0 +1,9 @@
|
||||||
|
#pragma once
|
||||||
|
#include <string>
|
||||||
|
#include <color/color.h> // 公开头引用了 color → color 必须是 PUBLIC 依赖
|
||||||
|
// 注意：这里没有 timeutil.h，也没有 PRINTER_TIME_FORMAT
|
||||||
|
|
||||||
|
class Printer {
|
||||||
|
public:
|
||||||
|
void print(const std::string& msg, Color c);
|
||||||
|
};
|
||||||
12
cmake/visibility/printer/src/printer.cpp
Normal file
12
cmake/visibility/printer/src/printer.cpp
Normal file
|
|
@ -0,0 +1,12 @@
|
||||||
|
#include "printer/printer.h"
|
||||||
|
#include "timeutil.h" // 只在实现里用 → timeutil 是 PRIVATE 依赖
|
||||||
|
#include <iostream>
|
||||||
|
|
||||||
|
#ifndef PRINTER_TIME_FORMAT // 只在本 .cpp 里用的宏 → PRIVATE
|
||||||
|
#define PRINTER_TIME_FORMAT "%H:%M:%S" // 没从 CMake 传进来时的兜底
|
||||||
|
#endif
|
||||||
|
|
||||||
|
void Printer::print(const std::string& msg, Color c) {
|
||||||
|
std::cout << timestamp(PRINTER_TIME_FORMAT) << " "
|
||||||
|
<< colorCode(c) << msg << "\033[0m" << std::endl;
|
||||||
|
}
|
||||||
9
cmake/visibility/timeutil/timeutil.cpp
Normal file
9
cmake/visibility/timeutil/timeutil.cpp
Normal file
|
|
@ -0,0 +1,9 @@
|
||||||
|
#include "timeutil.h"
|
||||||
|
#include <ctime>
|
||||||
|
|
||||||
|
std::string timestamp(const char* fmt) {
|
||||||
|
char buf[32];
|
||||||
|
std::time_t t = std::time(nullptr);
|
||||||
|
std::strftime(buf, sizeof(buf), fmt, std::localtime(&t));
|
||||||
|
return buf;
|
||||||
|
}
|
||||||
3
cmake/visibility/timeutil/timeutil.h
Normal file
3
cmake/visibility/timeutil/timeutil.h
Normal file
|
|
@ -0,0 +1,3 @@
|
||||||
|
#pragma once
|
||||||
|
#include <string>
|
||||||
|
std::string timestamp(const char* fmt); // fmt 形如 "%H:%M:%S"
|
||||||
Loading…
Add table
Add a link
Reference in a new issue