Repository: phylum-dev/birdcage Branch: main Commit: d0c625188385 Files: 45 Total size: 159.0 KB Directory structure: gitextract_c3jrejhf/ ├── .github/ │ ├── PULL_REQUEST_TEMPLATE.md │ ├── dependabot.yml │ └── workflows/ │ └── test.yml ├── .gitignore ├── CHANGELOG.md ├── CODE_OF_CONDUCT.md ├── Cargo.toml ├── LICENSE ├── README.md ├── SECURITY.md ├── examples/ │ └── sandbox.rs ├── integration/ │ ├── canonicalize.rs │ ├── command_io.rs │ ├── consistent_id_mappings.rs │ ├── delete_before_lockdown.rs │ ├── env.rs │ ├── exec.rs │ ├── exec_symlinked_dir.rs │ ├── exec_symlinked_dirs_exec.rs │ ├── exec_symlinked_file.rs │ ├── fs.rs │ ├── fs_broken_symlink.rs │ ├── fs_null.rs │ ├── fs_readonly.rs │ ├── fs_restrict_child.rs │ ├── fs_symlink.rs │ ├── fs_symlink_dir.rs │ ├── fs_symlink_dir_separate_perms.rs │ ├── fs_write_also_read.rs │ ├── full_env.rs │ ├── full_sandbox.rs │ ├── harness.rs │ ├── missing_exception.rs │ ├── net.rs │ └── seccomp.rs ├── rustfmt.toml └── src/ ├── error.rs ├── lib.rs ├── linux/ │ ├── mod.rs │ ├── namespaces.rs │ └── seccomp.rs ├── macos.rs └── process/ ├── linux.rs ├── macos.rs └── mod.rs ================================================ FILE CONTENTS ================================================ ================================================ FILE: .github/PULL_REQUEST_TEMPLATE.md ================================================ ================================================ FILE: .github/dependabot.yml ================================================ --- version: 2 updates: - package-ecosystem: "github-actions" directory: "/" schedule: interval: weekly ================================================ FILE: .github/workflows/test.yml ================================================ name: Test on: # Allow running this workflow manually from the Actions tab workflow_dispatch: pull_request: push: branches: - main tags: - '*' # Run weekly on the default branch to make sure it always builds with the latest rust release schedule: - cron: '30 5 * * 1' jobs: test-matrix: strategy: fail-fast: false matrix: os: - ubuntu-latest - macos-latest runs-on: ${{ matrix.os }} steps: - name: Checkout repository uses: actions/checkout@v6 - name: Install Rust toolchain run: | curl --proto '=https' --tlsv1.2 -sSfL https://sh.rustup.rs \ | sh -s -- -y --default-toolchain stable --profile minimal -c clippy echo "$HOME/.cargo/bin" >> "$GITHUB_PATH" - name: Test Stable run: | # On Ubuntu use busybox to bypass user namespace restrictions. if command -v busybox; then busybox sh -c "cargo +stable test" else cargo +stable test fi - name: Test Oldstable run: | oldstable=$(cat Cargo.toml | grep rust-version | sed 's/.*"\(.*\)".*/\1/') rustup toolchain install --profile minimal $oldstable # On Ubuntu use busybox to bypass user namespace restrictions. if command -v busybox; then busybox sh -c "cargo +$oldstable test" else cargo "+$oldstable" test fi - name: Clippy run: cargo +stable clippy - name: Rustfmt run: | rustup toolchain install nightly -c rustfmt cargo +nightly fmt -- --check # This job reports the results of the test jobs above and is used # to enforce status checks in the repo settings without needing # to update those settings every time the test jobs are updated. test-rollup: name: Test rollup runs-on: ubuntu-latest if: always() needs: test-matrix steps: - name: Check for test jobs failure or cancellation if: contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') run: exit 1 ================================================ FILE: .gitignore ================================================ /target /Cargo.lock ================================================ FILE: CHANGELOG.md ================================================ # Changelog Notable changes to Birdcage are documented in this file. The sections should follow the order `Packaging`, `Added`, `Changed`, `Fixed` and `Removed`. The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/). ## [0.8.1] - 2024-04-19 ### Fixed - Conversion from Birdcage's to STD's `Command` inheriting all STDIO ## [0.8.0] - 2024-04-19 ### Changed - `Sandbox::spawn` now takes a `birdcage::process::Command` ### Fixed - (Linux) Sandboxed process not killed when parent is terminated with a signal ## [0.7.1] - 2024-02-07 ### Changed - (Linux) Improved error message with unsupported Kernel versions ## [0.7.0] - 2023-11-30 ### Added - (Linux) PID namespace support ### Fixed - (Linux) Sandbox lockdown failing when deleting file after adding exception - (Linux) Environment variables accessible through procfs interface ## [0.6.0] - 2023-11-16 ### Fixed - (Linux) Sandbox exceptions for symbolic links - (macOS) Modifying exceptions for paths affected by existing exceptions - (Linux) Symlink/Canonical path's exceptions overriding each other ## [v0.5.0] - 2023-10-13 ### Changed - (Linux) Report invalid paths when adding exceptions - `Exception::Write` changed to `Exception::WriteAndRead` ### Fixed - (Linux) Root filesystem exceptions failing sandbox creation - (Linux) Sandbox not enforcing readonly/noexec restrictions - (Linux) Exceptions for special files (i.e. /dev/null) ## [0.4.0] - 2023-10-09 ### Added - (Linux) Seccomp system call filter ### Changed - (Linux) Minimum Kernel version reduced to 3.8 - The sandboxing process now must be single-threaded ### Fixed - (Linux) Abstract namespace isolation - (Linux) Socket and pipe isolation ### Contributors We'd like to thank [@bjorn3](https://github.com/bjorn3) for disclosing an issue with socket isolation. ## [0.3.1] - 2023-08-31 ### Fixed - Local sockets denied by network sandbox on Linux ## [0.3.0] - 2023-08-31 ### Changed - Linux seccomp network filtering now uses a whitelist instead of a blacklist ================================================ FILE: CODE_OF_CONDUCT.md ================================================ # Contributor Covenant Code of Conduct ## Our Pledge We as members, contributors, and leaders pledge to make participation in our community a harassment-free experience for everyone, regardless of age, body size, visible or invisible disability, ethnicity, sex characteristics, gender identity and expression, level of experience, education, socio-economic status, nationality, personal appearance, race, caste, color, religion, or sexual identity and orientation. We pledge to act and interact in ways that contribute to an open, welcoming, diverse, inclusive, and healthy community. ## Our Standards Examples of behavior that contributes to a positive environment for our community include: * Demonstrating empathy and kindness toward other people * Being respectful of differing opinions, viewpoints, and experiences * Giving and gracefully accepting constructive feedback * Accepting responsibility and apologizing to those affected by our mistakes, and learning from the experience * Focusing on what is best not just for us as individuals, but for the overall community Examples of unacceptable behavior include: * The use of sexualized language or imagery, and sexual attention or advances of any kind * Trolling, insulting or derogatory comments, and personal or political attacks * Public or private harassment * Publishing others' private information, such as a physical or email address, without their explicit permission * Other conduct which could reasonably be considered inappropriate in a professional setting ## Enforcement Responsibilities Community leaders are responsible for clarifying and enforcing our standards of acceptable behavior and will take appropriate and fair corrective action in response to any behavior that they deem inappropriate, threatening, offensive, or harmful. Community leaders have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, and will communicate reasons for moderation decisions when appropriate. ## Scope This Code of Conduct applies within all community spaces, and also applies when an individual is officially representing the community in public spaces. Examples of representing our community include using an official e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. ## Enforcement Instances of abusive, harassing, or otherwise unacceptable behavior may be reported to the community leaders responsible for enforcement at [engineering@phylum.io](mailto:engineering@phylum.io). All complaints will be reviewed and investigated promptly and fairly. All community leaders are obligated to respect the privacy and security of the reporter of any incident. ## Enforcement Guidelines Community leaders will follow these Community Impact Guidelines in determining the consequences for any action they deem in violation of this Code of Conduct: ### 1. Correction **Community Impact**: Use of inappropriate language or other behavior deemed unprofessional or unwelcome in the community. **Consequence**: A private, written warning from community leaders, providing clarity around the nature of the violation and an explanation of why the behavior was inappropriate. A public apology may be requested. ### 2. Warning **Community Impact**: A violation through a single incident or series of actions. **Consequence**: A warning with consequences for continued behavior. No interaction with the people involved, including unsolicited interaction with those enforcing the Code of Conduct, for a specified period of time. This includes avoiding interactions in community spaces as well as external channels like social media. Violating these terms may lead to a temporary or permanent ban. ### 3. Temporary Ban **Community Impact**: A serious violation of community standards, including sustained inappropriate behavior. **Consequence**: A temporary ban from any sort of interaction or public communication with the community for a specified period of time. No public or private interaction with the people involved, including unsolicited interaction with those enforcing the Code of Conduct, is allowed during this period. Violating these terms may lead to a permanent ban. ### 4. Permanent Ban **Community Impact**: Demonstrating a pattern of violation of community standards, including sustained inappropriate behavior, harassment of an individual, or aggression toward or disparagement of classes of individuals. **Consequence**: A permanent ban from any sort of public interaction within the community. ## Attribution This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 2.1, available at [https://www.contributor-covenant.org/version/2/1/code_of_conduct.html][v2.1]. Community Impact Guidelines were inspired by [Mozilla's code of conduct enforcement ladder][Mozilla CoC]. For answers to common questions about this code of conduct, see the FAQ at [https://www.contributor-covenant.org/faq][FAQ]. Translations are available at [https://www.contributor-covenant.org/translations][translations]. [homepage]: https://www.contributor-covenant.org [v2.1]: https://www.contributor-covenant.org/version/2/1/code_of_conduct.html [Mozilla CoC]: https://github.com/mozilla/diversity [FAQ]: https://www.contributor-covenant.org/faq [translations]: https://www.contributor-covenant.org/translations ================================================ FILE: Cargo.toml ================================================ [package] name = "birdcage" version = "0.8.1" description = "Cross-platform embeddable sandbox" authors = ["Phylum, Inc. "] repository = "https://github.com/phylum-dev/birdcage" documentation = "https://docs.rs/birdcage" rust-version = "1.70.0" license = "GPL-3.0-or-later" edition = "2021" [[test]] name = "harness" path = "integration/harness.rs" harness = false [[test]] name = "command_io" path = "integration/command_io.rs" harness = false [target.'cfg(target_os = "linux")'.dependencies] libc = "0.2.132" log = "0.4.20" rustix = { version = "0.38.31", features = ["pipe", "stdio", "thread", "process", "fs"] } seccompiler = "0.3.0" [dev-dependencies] clap = { version = "3.2.17", features = ["derive"] } serde_json = "1.0.108" serde = { version = "1.0.193", features = ["derive"] } tempfile = "3.3.0" [dependencies] bitflags = "2.4.0" ================================================ FILE: LICENSE ================================================ GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007 Copyright © 2007 Free Software Foundation, Inc. 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If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee. END OF TERMS AND CONDITIONS How to Apply These Terms to Your New Programs If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found. Birdcage, cross-platform embeddable sandbox Copyright (C) 2022 Phylum, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . Also add information on how to contact you by electronic and paper mail. If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode: Birdcage Copyright (C) 2022 Phylum, Inc. This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an “about box”. You should also get your employer (if you work as a programmer) or school, if any, to sign a “copyright disclaimer” for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see . The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read . ================================================ FILE: README.md ================================================ # Birdcage
[![GitHub](https://img.shields.io/github/license/phylum-dev/birdcage)][license] [![GitHub issues](https://img.shields.io/github/issues/phylum-dev/birdcage)][issues] [![Contributor Covenant](https://img.shields.io/badge/Contributor%20Covenant-2.1-4baaaa.svg)][CoC] [![Crate](https://img.shields.io/crates/v/birdcage)](https://crates.io/crates/birdcage) [![Documentation](https://docs.rs/birdcage/badge.svg)](https://docs.rs/birdcage) [license]: https://github.com/phylum-dev/birdcage/blob/main/LICENSE [issues]: https://github.com/phylum-dev/birdcage/issues [CoC]: https://github.com/phylum-dev/birdcage/blob/main/CODE_OF_CONDUCT.md [![Birdcage logo](./assets/Birdcage.png)][protection]
## About Birdcage is a cross-platform embeddable sandboxing library allowing restrictions to Filesystem and Network operations using native operating system APIs. Birdcage was originally developed for use by the [Phylum CLI] as an extra layer of [protection] against potentially malicious dependencies (see the [blog post] for details). To better protect yourself from these security risks, [sign up now]! [phylum cli]: https://github.com/phylum-dev/cli [protection]: https://www.phylum.io/defend-developers [blog post]: https://blog.phylum.io/sandboxing-package-installations-arms-developers-with-defense-against-open-source-attacks-and-unintended-consequences/ [sign up now]: https://www.phylum.io/ Birdcage focuses **only** on Filesystem and Network operations. It **is not** a complete sandbox preventing all side-effects or permanent damage. Applications can still execute most system calls, which is especially dangerous when execution is performed as root. Birdcage should be combined with other security mechanisms, especially if you are executing known-malicious code. ## Example An example for using Birdcage's API can be found in `./examples/sandbox`, which runs an application with CLI-configurable restrictions applied. Trying to run without any exceptions will produce an error: ```bash $ cargo run --example sandbox -- echo "Hello, Sandbox\!" Error: Os { code: 13, kind: PermissionDenied, message: "Permission denied" } ``` Running the same command with explicit permissions allows execution: ```bash $ cargo run --example sandbox -- -e /usr/bin/echo -e /usr/lib echo "Hello, Sandbox\!" Hello, Sandbox! ``` Check out `cargo run --example sandbox -- --help` for more information on how to use the example. ## Supported Platforms - Linux via [namespaces] - macOS via `sandbox_init()` (aka Seatbelt) [namespaces]: https://man7.org/linux/man-pages/man7/namespaces.7.html ================================================ FILE: SECURITY.md ================================================ # Security Policy Phylum was founded by a team of security researchers at heart, and we take the security of our tooling seriously. ## Reporting a Vulnerability We love coordinated disclosure! Please email [security@phylum.io](mailto:security@phylum.io) to start a conversation! We'll coordinate a secure communication mechanism first, then evaluate the reported issue(s) and keep you apprised each step of the way. ================================================ FILE: examples/sandbox.rs ================================================ //! Sandbox arbitrary executables. use std::error::Error; use std::path::PathBuf; use birdcage::process::Command; use birdcage::{Birdcage, Exception, Sandbox}; use clap::{Parser, ValueHint}; #[derive(Parser)] #[clap(author, about)] struct Cli { /// Allowed read paths. #[clap(short = 'r', long, value_name = "PATH", value_hint = ValueHint::AnyPath)] allow_read: Vec, /// Allowed write paths. #[clap(short = 'w', long, value_name = "PATH", value_hint = ValueHint::AnyPath)] allow_write: Vec, /// Allowed read and execute paths. #[clap(short = 'e', long, value_name = "PATH", value_hint = ValueHint::AnyPath)] allow_execute: Vec, /// Allowed environment variable access. #[clap(long, value_name = "VAR")] allow_env: Vec, /// Allow networking. #[clap(short = 'n', long)] allow_networking: bool, /// Command to be executed in the sandbox. cmd: String, /// Arguments for the sandboxed command. #[clap(allow_hyphen_values = true, multiple_values = true)] args: Vec, } fn main() -> Result<(), Box> { let cli = Cli::parse(); // Setup sandbox and its exceptions. let mut birdcage = Birdcage::new(); for path in cli.allow_read { birdcage.add_exception(Exception::Read(path))?; } for path in cli.allow_write { birdcage.add_exception(Exception::WriteAndRead(path))?; } for path in cli.allow_execute { birdcage.add_exception(Exception::ExecuteAndRead(path))?; } for var in cli.allow_env { birdcage.add_exception(Exception::Environment(var))?; } if cli.allow_networking { birdcage.add_exception(Exception::Networking)?; } // Activate sandbox. let mut command = Command::new(cli.cmd); command.args(&cli.args); let mut child = birdcage.spawn(command)?; // Wait for sandboxee to exit. child.wait()?; std::process::exit(0); } ================================================ FILE: integration/canonicalize.rs ================================================ use std::fs; use std::path::PathBuf; use birdcage::{Birdcage, Exception, Sandbox}; use crate::TestSetup; pub fn setup(_tempdir: PathBuf) -> TestSetup { let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::Read("./".into())).unwrap(); TestSetup { sandbox, data: String::new() } } pub fn validate(_data: String) { // Check for success on reading the `Cargo.toml` file. let file = fs::read_to_string("./Cargo.toml").unwrap(); assert!(file.contains("birdcage")); } ================================================ FILE: integration/command_io.rs ================================================ use std::io::Write; use std::os::unix::process::ExitStatusExt; use birdcage::process::{Command, Stdio}; use birdcage::{Birdcage, Exception, Sandbox}; // macOs uses `std::process` and thus does not require explicit testing. This // allows running multiple tests in the same process rather than having to add // multiple integeration tests. #[cfg(not(target_os = "linux"))] fn main() {} #[cfg(target_os = "linux")] fn main() { pipe_stdin_to_stdout(); exit_signal(); } #[cfg(target_os = "linux")] fn pipe_stdin_to_stdout() { // Setup echo-back command. let mut cmd = Command::new("cat"); cmd.stdin(Stdio::piped()); cmd.stdout(Stdio::piped()); // Spawn sandbox child. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::ExecuteAndRead("/".into())).unwrap(); sandbox.add_exception(Exception::WriteAndRead("/".into())).unwrap(); let mut child = sandbox.spawn(cmd).unwrap(); // Write test data to stdin. let expected = b"test\n"; child.stdin.as_mut().unwrap().write_all(expected).unwrap(); // Read stdout. let output = child.wait_with_output().unwrap(); assert_eq!(&output.stdout, expected); } #[cfg(target_os = "linux")] fn exit_signal() { // Setup echo-back command. let cmd = Command::new("cat"); // Spawn sandbox child. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::ExecuteAndRead("/".into())).unwrap(); sandbox.add_exception(Exception::WriteAndRead("/".into())).unwrap(); let mut child = sandbox.spawn(cmd).unwrap(); // Kill the child. child.kill().unwrap(); // Read stdout. let status = child.wait().unwrap(); assert_eq!(status.signal(), Some(9)); } ================================================ FILE: integration/consistent_id_mappings.rs ================================================ use std::path::PathBuf; use birdcage::{Birdcage, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; #[derive(Serialize, Deserialize)] struct TestData { uid: u32, gid: u32, euid: u32, egid: u32, } pub fn setup(_tempdir: PathBuf) -> TestSetup { let uid = unsafe { libc::getuid() }; let gid = unsafe { libc::getgid() }; let euid = unsafe { libc::geteuid() }; let egid = unsafe { libc::getegid() }; let sandbox = Birdcage::new(); // Serialize test data. let data = TestData { uid, gid, euid, egid }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); assert_eq!(data.uid, unsafe { libc::getuid() }); assert_eq!(data.gid, unsafe { libc::getgid() }); assert_eq!(data.euid, unsafe { libc::geteuid() }); assert_eq!(data.egid, unsafe { libc::getegid() }); } ================================================ FILE: integration/delete_before_lockdown.rs ================================================ use std::path::PathBuf; use birdcage::{Birdcage, Exception, Sandbox}; use tempfile::NamedTempFile; use crate::TestSetup; pub fn setup(_tempdir: PathBuf) -> TestSetup { // Create temporary file. let tempfile = NamedTempFile::new().unwrap(); // Setup sandbox exceptions. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::Read(tempfile.path().into())).unwrap(); tempfile.close().unwrap(); TestSetup { sandbox, data: String::new() } } pub fn validate(_data: String) { // We just want to test sandbox creation worked. } ================================================ FILE: integration/env.rs ================================================ use std::path::PathBuf; use std::env; use birdcage::{Birdcage, Exception, Sandbox}; use crate::TestSetup; pub fn setup(_tempdir: PathBuf) -> TestSetup { // Setup our environment variables env::set_var("PUBLIC", "GOOD"); env::set_var("PRIVATE", "BAD"); // Activate our sandbox. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::Environment("PUBLIC".into())).unwrap(); TestSetup { sandbox, data: String::new() } } pub fn validate(_data: String) { // Only the `PUBLIC` environment variable remains. let env: Vec<_> = env::vars().collect(); assert_eq!(env, vec![("PUBLIC".into(), "GOOD".into())]); } ================================================ FILE: integration/exec.rs ================================================ use std::path::PathBuf; use std::fs; use std::process::Command; use birdcage::{Birdcage, Exception, Sandbox}; use crate::TestSetup; pub fn setup(_tempdir: PathBuf) -> TestSetup { let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::ExecuteAndRead("/usr/bin/true".into())).unwrap(); TestSetup { sandbox, data: String::new() } } pub fn validate(_data: String) { // Check for success when executing `true`. let cmd = Command::new("/usr/bin/true").status().unwrap(); assert!(cmd.success()); // Check for success on reading the `true` file. let cmd_file = fs::read("/usr/bin/true"); assert!(cmd_file.is_ok()); } ================================================ FILE: integration/exec_symlinked_dir.rs ================================================ use std::os::unix::fs as unixfs; use std::path::PathBuf; use std::process::Command; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; #[derive(Serialize, Deserialize)] struct TestData { symlink_dir: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Create symlinked executable dir. let symlink_dir = tempdir.join("bin"); unixfs::symlink("/usr/bin", &symlink_dir).unwrap(); let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::ExecuteAndRead(symlink_dir.clone())).unwrap(); // Serialize test data. let data = TestData { symlink_dir }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Ensure symlinked dir's executable works. let symlink_dir_exec = data.symlink_dir.join("true"); let cmd = Command::new(symlink_dir_exec).status().unwrap(); assert!(cmd.success()); // Ensure original dir's executable works. let cmd = Command::new("/usr/bin/true").status().unwrap(); assert!(cmd.success()); } ================================================ FILE: integration/exec_symlinked_dirs_exec.rs ================================================ use std::os::unix::fs as unixfs; use std::path::PathBuf; use std::process::Command; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; #[derive(Serialize, Deserialize)] struct TestData { symlink_dir_exec: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Create symlinked executable dir. let symlink_dir = tempdir.join("bin"); let symlink_dir_exec = symlink_dir.join("true"); unixfs::symlink("/usr/bin", &symlink_dir).unwrap(); let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::ExecuteAndRead(symlink_dir_exec.clone())).unwrap(); // Serialize test data. let data = TestData { symlink_dir_exec }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Ensure symlinked dir's executable works. let cmd = Command::new(data.symlink_dir_exec).status().unwrap(); assert!(cmd.success()); // Ensure original dir's executable works. let cmd = Command::new("/usr/bin/true").status().unwrap(); assert!(cmd.success()); } ================================================ FILE: integration/exec_symlinked_file.rs ================================================ use std::fs; use std::os::unix::fs as unixfs; use std::path::PathBuf; use std::process::Command; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; #[derive(Serialize, Deserialize)] struct TestData { symlink_exec: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Create symlinked executable. let exec_dir = tempdir.join("bin"); fs::create_dir(&exec_dir).unwrap(); let symlink_exec = exec_dir.join("true"); unixfs::symlink("/usr/bin/true", &symlink_exec).unwrap(); let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::ExecuteAndRead(symlink_exec.clone())).unwrap(); // Serialize test data. let data = TestData { symlink_exec }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Ensure symlinked executable works. let cmd = Command::new(data.symlink_exec).status().unwrap(); assert!(cmd.success()); // Ensure original executable works. let cmd = Command::new("/usr/bin/true").status().unwrap(); assert!(cmd.success()); } ================================================ FILE: integration/fs.rs ================================================ use std::fs; use std::path::PathBuf; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; const FILE_CONTENT: &str = "expected content"; #[derive(Serialize, Deserialize)] struct TestData { public_path: PathBuf, private_path: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Setup our test files. let private_path = tempdir.join("private"); fs::write(&private_path, FILE_CONTENT.as_bytes()).unwrap(); let public_path = tempdir.join("public"); fs::write(&public_path, FILE_CONTENT.as_bytes()).unwrap(); // Setup sandbox exceptions. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::Read(public_path.clone())).unwrap(); // Serialize test data. let data = TestData { public_path, private_path }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Access to the public file is allowed. let content = fs::read_to_string(data.public_path).unwrap(); assert_eq!(content, FILE_CONTENT); // Access to the private file is prohibited. let result = fs::read_to_string(data.private_path); assert!(result.is_err()); } ================================================ FILE: integration/fs_broken_symlink.rs ================================================ use std::fs::{self, File}; use std::os::unix::fs as unixfs; use std::path::PathBuf; use birdcage::error::Error; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; #[derive(Serialize, Deserialize)] struct TestData { symlink: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Create a target for the symlink. let tempfile_path = tempdir.join("broken_target"); File::create(&tempfile_path).unwrap(); // Setup a symlink to the target file. let symlink_str = tempfile_path.to_string_lossy() + "_symlink"; let symlink = PathBuf::from(symlink_str.as_ref()); unixfs::symlink(&tempfile_path, &symlink).unwrap(); // Remove the target, breaking the symlink. fs::remove_file(&tempfile_path).unwrap(); assert!(!tempfile_path.exists()); // Sandbox exception fails with invalid path error. let mut sandbox = Birdcage::new(); let result = sandbox.add_exception(Exception::Read(symlink.clone())); assert!(matches!(result, Err(Error::InvalidPath(_)))); // Serialize test data. let data = TestData { symlink }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Read/Write results in error. let result = fs::read_to_string(&data.symlink); assert!(result.is_err()); let result = fs::write(&data.symlink, "bob"); assert!(result.is_err()); } ================================================ FILE: integration/fs_null.rs ================================================ use std::path::PathBuf; use std::fs; use birdcage::{Birdcage, Exception, Sandbox}; use crate::TestSetup; pub fn setup(_tempdir: PathBuf) -> TestSetup { // Activate our sandbox. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::WriteAndRead("/dev/null".into())).unwrap(); TestSetup { sandbox, data: String::new() } } pub fn validate(_data: String) { // Writing to `/dev/null` is allowed. fs::write("/dev/null", "blub").unwrap(); } ================================================ FILE: integration/fs_readonly.rs ================================================ use std::fs; use std::path::PathBuf; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; const FILE_CONTENT: &str = "expected content"; #[derive(Serialize, Deserialize)] struct TestData { file: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Setup the test file. let file = tempdir.join("fs_readonly"); fs::write(&file, FILE_CONTENT.as_bytes()).unwrap(); // Activate our sandbox. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::Read(file.clone())).unwrap(); // Serialize test data. let data = TestData { file }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Reading from the file is allowed. let content = fs::read_to_string(&data.file).unwrap(); assert_eq!(content, FILE_CONTENT); // Writing to the file is prohibited. let result = fs::write(&data.file, FILE_CONTENT.as_bytes()); assert!(result.is_err()); } ================================================ FILE: integration/fs_restrict_child.rs ================================================ use std::fs; use std::path::PathBuf; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; const FILE_CONTENT: &str = "expected content"; #[derive(Serialize, Deserialize)] struct TestData { tempfile: PathBuf, tempdir: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Setup our test tree. let tempfile = tempdir.join("target-file"); fs::write(&tempfile, FILE_CONTENT.as_bytes()).unwrap(); // Setup sandbox, allowing read/write to dir, but only read for the file. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::WriteAndRead(tempdir.clone())).unwrap(); sandbox.add_exception(Exception::Read(tempfile.clone())).unwrap(); // Serialize test data. let data = TestData { tempfile, tempdir }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Write access to directory works. fs::create_dir(data.tempdir.join("boop")).unwrap(); // Read access to file works. let content = fs::read_to_string(&data.tempfile).unwrap(); assert_eq!(content, FILE_CONTENT); // Write access to file is denied. let result = fs::write(&data.tempfile, "no"); assert!(result.is_err()); } ================================================ FILE: integration/fs_symlink.rs ================================================ use std::fs; use std::os::unix::fs as unixfs; use std::path::PathBuf; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; const FILE_CONTENT: &str = "expected content"; #[derive(Serialize, Deserialize)] struct TestData { private: PathBuf, public: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Setup our test files. let private_path = tempdir.join("private"); fs::write(&private_path, FILE_CONTENT.as_bytes()).unwrap(); let public_path = tempdir.join("public"); fs::write(&public_path, FILE_CONTENT.as_bytes()).unwrap(); // Create symlinks for the files. let private_str = private_path.to_string_lossy() + "_tmpfile"; let private = PathBuf::from(private_str.as_ref()); let public_str = public_path.to_string_lossy() + "_tmpfile"; let public = PathBuf::from(public_str.as_ref()); unixfs::symlink(&private_path, &private).unwrap(); unixfs::symlink(&public_path, &public).unwrap(); // Activate our sandbox. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::Read(public.clone())).unwrap(); // Serialize test data. let data = TestData { private, public }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Access to the public file is allowed. let content = fs::read_to_string(&data.public).unwrap(); assert_eq!(content, FILE_CONTENT); // Access to the private file is prohibited. let result = fs::read_to_string(&data.private); assert!(result.is_err()); } ================================================ FILE: integration/fs_symlink_dir.rs ================================================ use std::fs; use std::os::unix::fs as unixfs; use std::path::PathBuf; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; const FILE_CONTENT: &str = "expected content"; #[derive(Serialize, Deserialize)] struct TestData { symlink: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Setup our test directory. let symlink_target = tempdir.join("target"); fs::create_dir(symlink_target).unwrap(); let symlink = tempdir.join("symlink"); unixfs::symlink(&tempdir, &symlink).unwrap(); // Activate our sandbox. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::WriteAndRead(symlink.clone())).unwrap(); // Serialize test data. let data = TestData { symlink }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Try to create a file in the symlinked directory. let path = data.symlink.join("tmpfile"); fs::write(&path, FILE_CONTENT.as_bytes()).unwrap(); let content = fs::read_to_string(&path).unwrap(); assert_eq!(content, FILE_CONTENT); } ================================================ FILE: integration/fs_symlink_dir_separate_perms.rs ================================================ use std::fs; use std::os::unix::fs as unixfs; use std::path::PathBuf; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; const FILE_CONTENT: &str = "expected content"; #[derive(Serialize, Deserialize)] struct TestData { symlink_src: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Setup our test directories. let symlink_src = tempdir.join("src"); fs::create_dir(&symlink_src).unwrap(); let symlink_dst = tempdir.join("dst"); unixfs::symlink(&symlink_src, &symlink_dst).unwrap(); // Add read+write for src, but also add readonly for dst. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::WriteAndRead(symlink_src.clone())).unwrap(); sandbox.add_exception(Exception::Read(symlink_dst.clone())).unwrap(); // Serialize test data. let data = TestData { symlink_src }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Ensure writing works. let testfile = data.symlink_src.join("file"); fs::write(&testfile, FILE_CONTENT).unwrap(); // Ensure reading works. let content = fs::read_to_string(&testfile).unwrap(); assert_eq!(content, FILE_CONTENT); } ================================================ FILE: integration/fs_write_also_read.rs ================================================ use std::fs::{self, File}; use std::path::PathBuf; use birdcage::{Birdcage, Exception, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; const FILE_CONTENT: &str = "expected content"; #[derive(Serialize, Deserialize)] struct TestData { path: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { // Setup our test files. let path = tempdir.join("fs_write_also_read"); File::create(&path).unwrap(); // Activate our sandbox. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::WriteAndRead(path.clone())).unwrap(); // Serialize test data. let data = TestData { path }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Write access is allowed. fs::write(&data.path, FILE_CONTENT.as_bytes()).unwrap(); // Read access is allowed. let content = fs::read_to_string(data.path).unwrap(); assert_eq!(content, FILE_CONTENT); } ================================================ FILE: integration/full_env.rs ================================================ use std::path::PathBuf; use std::env; use birdcage::{Birdcage, Exception, Sandbox}; use crate::TestSetup; pub fn setup(_tempdir: PathBuf) -> TestSetup { // Setup our environment variables env::set_var("PUBLIC", "GOOD"); // Activate our sandbox. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::FullEnvironment).unwrap(); TestSetup { sandbox, data: String::new() } } pub fn validate(_data: String) { // The `PUBLIC` environment variable can be accessed. assert_eq!(env::var("PUBLIC"), Ok("GOOD".into())); } ================================================ FILE: integration/full_sandbox.rs ================================================ use std::net::TcpStream; use std::path::PathBuf; use std::process::Command; use std::{env, fs}; use birdcage::{Birdcage, Sandbox}; use serde::{Deserialize, Serialize}; use crate::TestSetup; #[derive(Serialize, Deserialize)] struct TestData { path: PathBuf, } pub fn setup(tempdir: PathBuf) -> TestSetup { const FILE_CONTENT: &str = "expected content"; // Create testfile. let path = tempdir.join("full_sandbox"); // Ensure non-sandboxed write works. fs::write(&path, FILE_CONTENT.as_bytes()).unwrap(); // Ensure non-sandboxed read works. let content = fs::read_to_string(&path).unwrap(); assert_eq!(content, FILE_CONTENT); // Ensure non-sandboxed socket connect works. let stream = TcpStream::connect("phylum.io:443"); assert!(stream.is_ok()); drop(stream); // Ensure non-sandboxed execution works. let cmd = Command::new("/usr/bin/true").status(); assert!(cmd.is_ok()); // Ensure non-sandboxed env access works. env::set_var("TEST", "value"); assert_eq!(env::var("TEST"), Ok("value".into())); // Setup birdcage sandbox. let sandbox = Birdcage::new(); // Serialize test data. let data = TestData { path }; let data = serde_json::to_string(&data).unwrap(); TestSetup { sandbox, data } } pub fn validate(data: String) { // Deserialize test data. let data: TestData = serde_json::from_str(&data).unwrap(); // Ensure sandboxed write is blocked. let result = fs::write(&data.path, b"x"); assert!(result.is_err()); // Ensure sandboxed read is blocked. let result = fs::read_to_string(data.path); assert!(result.is_err()); // Ensure sandboxed socket connect is blocked. let stream = TcpStream::connect("phylum.io:443"); assert!(stream.is_err()); drop(stream); // Ensure sandboxed execution is blocked. let cmd = Command::new("/usr/bin/true").status(); assert!(cmd.is_err()); // Ensure sandboxed env access is blocked. assert_eq!(env::var_os("TEST"), None); } ================================================ FILE: integration/harness.rs ================================================ use std::path::PathBuf; use std::process::{self, Command, Stdio}; use birdcage::{Birdcage, Exception, Sandbox}; test_mods! { mod canonicalize; #[cfg(target_os = "linux")] mod consistent_id_mappings; mod delete_before_lockdown; mod env; mod exec; mod exec_symlinked_dir; mod exec_symlinked_dirs_exec; mod exec_symlinked_file; mod fs; mod fs_broken_symlink; mod fs_null; mod fs_readonly; mod fs_restrict_child; mod fs_symlink; mod fs_symlink_dir; mod fs_symlink_dir_separate_perms; mod fs_write_also_read; mod full_env; mod full_sandbox; mod missing_exception; mod net; #[cfg(target_os = "linux")] mod seccomp; } /// Integration test directory. const TEST_DIR: &str = "integration"; /// Test setup state. pub struct TestSetup { pub sandbox: Birdcage, pub data: String, } fn main() { let mut args = std::env::args().skip(1); // Get test name or spawn all the tests. let test_name = match args.next() { Some(test_name) => test_name, None => { spawn_tests(); return; }, }; // Find test matching the name. let test = match TESTS.iter().find(|(cmd, ..)| cmd == &test_name) { Some(test) => test, None => unreachable!("invalid test module name: {test_name:?}"), }; // Run setup or test validation. let arg = args.next().unwrap(); match arg.as_str() { "--setup" => { let tempdir = args.next().unwrap(); run_setup(&test_name, tempdir, &test.1); }, _ => test.2(arg), } } /// Reexecute binary to launch tests as separate processes. /// /// Returns `true` on success. fn spawn_tests() { eprintln!("\nrunning {} tests", TESTS.len()); // Spawn child processes for all tests. let current_exe = std::env::current_exe().unwrap(); let mut children = Vec::new(); for (cmd, ..) in TESTS { let tempdir = tempfile::tempdir().unwrap(); let child = Command::new(¤t_exe) .arg(cmd) .arg("--setup") .arg(tempdir.path()) .stderr(Stdio::piped()) .spawn() .unwrap(); children.push((cmd, child, tempdir)); } // Check results for each test. let mut passed = 0; for (name, child, tempdir) in children { let output = match child.wait_with_output() { Ok(output) => output, Err(err) => { eprintln!("test {TEST_DIR}/{name}.rs ... \x1b[31mHARNESS FAILURE\x1b[0m: {err}"); continue; }, }; // Report individual test results. if !output.status.success() { eprintln!("test {TEST_DIR}/{name}.rs ... \x1b[31mFAILED\x1b[0m"); // Print stderr on failure if there is some. let stderr = String::from_utf8_lossy(&output.stderr); if !stderr.is_empty() { eprintln!("\n---- {TEST_DIR}/{name}.rs stderr ----\n{}\n", stderr.trim()); } } else { eprintln!("test {TEST_DIR}/{name}.rs ... \x1b[32mok\x1b[0m"); passed += 1; } // Cleanup tempdir. tempdir.close().unwrap(); } // Print total results. let failed = TESTS.len() - passed; if failed > 0 { eprintln!("\ntest result: \x1b[31mFAILED\x1b[0m. {} passed; {} failed", passed, failed); } else { eprintln!("\ntest result: \x1b[32mok\x1b[0m. {} passed; {} failed", passed, failed); } eprintln!(); } /// Run test's setup step and spawn validation child. fn run_setup(test_name: &str, tempdir: String, setup: &fn(PathBuf) -> TestSetup) { // Run test setup. let mut test_setup = setup(PathBuf::from(tempdir)); // Add exceptions to allow self-execution. let current_exe = std::env::current_exe().unwrap(); for path in [current_exe.clone(), "/usr/lib".into(), "/lib64".into(), "/lib".into()] { if path.exists() { test_setup.sandbox.add_exception(Exception::ExecuteAndRead(path)).unwrap(); } } // Reexecute test with sandbox enabled. let mut command = birdcage::process::Command::new(current_exe); command.args([test_name, test_setup.data.as_str()]); let child = test_setup.sandbox.spawn(command).unwrap(); // Validate test results. let output = child.wait_with_output().unwrap(); if !output.status.success() { process::exit(output.status.code().unwrap_or(1)); } } #[macro_export] macro_rules! test_mods { ($($(#[$cfg:meta])? mod $mod:ident);*;) => { $( $( #[$cfg] )? mod $mod; )* const TESTS: &[(&str, fn(std::path::PathBuf) -> $crate::TestSetup, fn(String))] = &[$( $( #[$cfg] )? (stringify!($mod), $mod :: setup, $mod :: validate), )*]; }; } ================================================ FILE: integration/missing_exception.rs ================================================ use std::path::PathBuf; use birdcage::error::Error; use birdcage::{Birdcage, Exception, Sandbox}; use crate::TestSetup; pub fn setup(_tempdir: PathBuf) -> TestSetup { let mut sandbox = Birdcage::new(); // Add a path that doesn't exist. let result = sandbox.add_exception(Exception::Read("/does/not/exist".into())); // Ensure it is appropriately reported that exception was NOT added. match result { Err(Error::InvalidPath(path)) => assert_eq!(path, PathBuf::from("/does/not/exist")), _ => panic!("expected path error"), } TestSetup { sandbox, data: String::new() } } pub fn validate(_data: String) { // Ensure locking is always successful. } ================================================ FILE: integration/net.rs ================================================ use std::path::PathBuf; use std::net::TcpStream; use birdcage::{Birdcage, Exception, Sandbox}; use crate::TestSetup; pub fn setup(_tempdir: PathBuf) -> TestSetup { // Setup sandbox exceptions. let mut sandbox = Birdcage::new(); sandbox.add_exception(Exception::Networking).unwrap(); TestSetup { sandbox, data: String::new() } } pub fn validate(_data: String) { let result = TcpStream::connect("8.8.8.8:443"); assert!(result.is_ok()); } ================================================ FILE: integration/seccomp.rs ================================================ use std::path::PathBuf; use std::ffi::CString; use birdcage::{Birdcage, Sandbox}; use crate::TestSetup; pub fn setup(_tempdir: PathBuf) -> TestSetup { TestSetup { sandbox: Birdcage::new(), data: String::new() } } pub fn validate(_data: String) { // Ensure `chdir` is allowed. let root_path = CString::new("/").unwrap(); let result = unsafe { libc::chdir(root_path.as_ptr()) }; assert_eq!(result, 0); // Ensure `unshare` is always blocked. let result = unsafe { libc::unshare(libc::CLONE_NEWUSER) }; assert_eq!(result, -1); // Ensure `clone` is blocked with `CLONE_NEWUSER`. let stack = unsafe { libc::malloc(4096) }; let flags = libc::CLONE_NEWUSER as libc::c_ulong; let result = unsafe { libc::syscall(libc::SYS_clone, flags, stack) }; assert_eq!(result, -1); } ================================================ FILE: rustfmt.toml ================================================ format_code_in_doc_comments = true group_imports = "StdExternalCrate" match_block_trailing_comma = true condense_wildcard_suffixes = true use_field_init_shorthand = true normalize_doc_attributes = true overflow_delimited_expr = true imports_granularity = "Module" use_small_heuristics = "Max" normalize_comments = true reorder_impl_items = true use_try_shorthand = true newline_style = "Unix" format_strings = true wrap_comments = true ================================================ FILE: src/error.rs ================================================ //! Sandboxing errors. use std::error::Error as StdError; use std::fmt::{self, Display, Formatter}; use std::io::Error as IoError; #[cfg(target_os = "linux")] use std::io::ErrorKind as IoErrorKind; use std::path::PathBuf; use std::result::Result as StdResult; #[cfg(target_os = "linux")] use seccompiler::{BackendError, Error as SeccompError}; /// Birdcage result type. pub type Result = StdResult; /// Sandboxing error. #[derive(Debug)] pub enum Error { /// Seccomp errors. #[cfg(target_os = "linux")] Seccomp(SeccompError), /// Invalid sandbox exception path. InvalidPath(PathBuf), /// I/O error. Io(IoError), /// Sandbox activation failed. ActivationFailed(String), } impl StdError for Error {} impl Display for Error { fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result { match self { #[cfg(target_os = "linux")] Self::Seccomp(error) => write!(f, "seccomp error: {error}"), Self::InvalidPath(path) => write!(f, "invalid path: {path:?}"), #[cfg(target_os = "linux")] Self::Io(error) if error.kind() == IoErrorKind::Unsupported => { write!( f, "unsupported operation, please ensure Kernel version is at least 5.12: {error}" ) }, Self::Io(error) => write!(f, "input/output error: {error}"), Self::ActivationFailed(error) => { write!(f, "failed to initialize a sufficient sandbox: {error}") }, } } } #[cfg(target_os = "linux")] impl From for Error { fn from(error: SeccompError) -> Self { Self::Seccomp(error) } } #[cfg(target_os = "linux")] impl From for Error { fn from(error: BackendError) -> Self { Self::Seccomp(SeccompError::Backend(error)) } } impl From for Error { fn from(error: IoError) -> Self { Self::Io(error) } } ================================================ FILE: src/lib.rs ================================================ //! Birdcage sandbox. //! //! This crate provides a cross-platform API for an embedded sandbox for macOS //! and Linux. //! //! # Example //! //! ```rust //! use std::fs; //! //! use birdcage::process::Command; //! use birdcage::{Birdcage, Exception, Sandbox}; //! //! // Reads without sandbox work. //! fs::read_to_string("./Cargo.toml").unwrap(); //! //! // Allow access to our test executable. //! let mut sandbox = Birdcage::new(); //! sandbox.add_exception(Exception::ExecuteAndRead("/bin/cat".into())).unwrap(); //! let _ = sandbox.add_exception(Exception::ExecuteAndRead("/lib64".into())); //! let _ = sandbox.add_exception(Exception::ExecuteAndRead("/lib".into())); //! //! // Initialize the sandbox; by default everything is prohibited. //! let mut command = Command::new("/bin/cat"); //! command.arg("./Cargo.toml"); //! let mut child = sandbox.spawn(command).unwrap(); //! //! // Reads with sandbox should fail. //! let status = child.wait().unwrap(); //! assert!(!status.success()); //! ``` use std::env; use std::path::PathBuf; use crate::error::Result; #[cfg(target_os = "linux")] use crate::linux::LinuxSandbox; #[cfg(target_os = "macos")] use crate::macos::MacSandbox; use crate::process::{Child, Command}; pub mod error; #[cfg(target_os = "linux")] mod linux; #[cfg(target_os = "macos")] mod macos; pub mod process; /// Default platform sandbox. /// /// This type will automatically pick the default sandbox for each available /// platform. #[cfg(target_os = "linux")] pub type Birdcage = LinuxSandbox; /// Default platform sandbox. /// /// This type will automatically pick the default sandbox for each available /// platform. #[cfg(target_os = "macos")] pub type Birdcage = MacSandbox; pub trait Sandbox: Sized { /// Setup the sandboxing environment. fn new() -> Self; /// Add a new exception to the sandbox. /// /// Exceptions added for symlinks will also automatically apply to the /// symlink's target. fn add_exception(&mut self, exception: Exception) -> Result<&mut Self>; /// Setup sandbox and spawn a new process. /// /// This will setup the sandbox in the **CURRENT** process, before launching /// the sandboxee. Since most of the restrictions will also be applied to /// the calling process, it is recommended to create a separate process /// before calling this method. The calling process is **NOT** fully /// sandboxed. /// /// # Errors /// /// Sandboxing will fail if the calling process is not single-threaded. /// /// After failure, the calling process might still be affected by partial /// sandboxing restrictions. fn spawn(self, sandboxee: Command) -> Result; } /// Sandboxing exception rule. /// /// An exception excludes certain resources from the sandbox, allowing sandboxed /// applications to still access these resources. #[derive(Debug, Clone)] pub enum Exception { /// Allow read access to the path and anything beneath it. Read(PathBuf), /// Allow writing and reading the path and anything beneath it. WriteAndRead(PathBuf), /// Allow executing and reading the path and anything beneath it. /// /// This is grouped with reading as a convenience, since execution will /// always also require read access. ExecuteAndRead(PathBuf), /// Allow reading an environment variable. Environment(String), /// Allow reading **all** environment variables. FullEnvironment, /// Allow networking. Networking, } /// Restrict access to environment variables. pub(crate) fn restrict_env_variables(exceptions: &[String]) { // Invalid unicode will cause `env::vars()` to panic, so we don't have to worry // about them getting ignored. for (key, _) in env::vars().filter(|(key, _)| !exceptions.contains(key)) { env::remove_var(key); } } ================================================ FILE: src/linux/mod.rs ================================================ //! Linux sandboxing. use std::collections::HashMap; use std::ffi::CString; use std::io::{Error as IoError, ErrorKind as IoErrorKind}; use std::os::fd::OwnedFd; use std::os::unix::ffi::OsStrExt; use std::path::{Component, Path, PathBuf}; use std::{env, fs, io, ptr}; use rustix::pipe::pipe; use rustix::process::{Gid, Pid, Uid, WaitOptions}; use crate::error::{Error, Result}; use crate::linux::namespaces::{MountAttrFlags, Namespaces}; use crate::linux::seccomp::SyscallFilter; use crate::{Child, Command, Exception, Sandbox}; mod namespaces; mod seccomp; /// Linux sandboxing. #[derive(Default)] pub struct LinuxSandbox { env_exceptions: Vec, path_exceptions: PathExceptions, allow_networking: bool, full_env: bool, } impl Sandbox for LinuxSandbox { fn new() -> Self { Self::default() } fn add_exception(&mut self, exception: Exception) -> Result<&mut Self> { match exception { Exception::Read(path) => self.path_exceptions.update(path, false, false)?, Exception::WriteAndRead(path) => self.path_exceptions.update(path, true, false)?, Exception::ExecuteAndRead(path) => self.path_exceptions.update(path, false, true)?, Exception::Environment(key) => self.env_exceptions.push(key), Exception::FullEnvironment => self.full_env = true, Exception::Networking => self.allow_networking = true, } Ok(self) } fn spawn(self, sandboxee: Command) -> Result { // Ensure calling process is not multi-threaded. assert!( thread_count().unwrap_or(0) == 1, "`Sandbox::spawn` must be called from a single-threaded process" ); // Remove environment variables. if !self.full_env { crate::restrict_env_variables(&self.env_exceptions); } // Create pipes to hook up init's stdio. let stdin_pipe = sandboxee.stdin.make_pipe(true)?; let stdout_pipe = sandboxee.stdout.make_pipe(false)?; let stderr_pipe = sandboxee.stderr.make_pipe(false)?; let exit_signal_pipe = pipe().map_err(IoError::from)?; // Spawn isolated sandbox PID 1. let allow_networking = self.allow_networking; let init_arg = ProcessInitArg::new( self, sandboxee, exit_signal_pipe, stdin_pipe, stdout_pipe, stderr_pipe, ); let init_arg = spawn_sandbox_init(init_arg, allow_networking)?; // Deconstruct init args, dropping unused FDs. let (pid, stdin_tx, stdout_rx, stderr_rx, exit_signal_rx) = { let ProcessInitArg { // Extract used fields. pid, stdin_tx, stdout_rx, stderr_rx, exit_signal_rx, // Deconstruct all remaining fields to manually drop them. path_exceptions: _x0, exit_signal_tx: _x1, parent_euid: _x2, parent_egid: _x3, stdout_tx: _x4, stderr_tx: _x5, sandboxee: _x6, stdin_rx: _x7, } = init_arg; (pid, stdin_tx, stdout_rx, stderr_rx, exit_signal_rx) }; let child = Child::new(pid, exit_signal_rx, stdin_tx, stdout_rx, stderr_rx)?; Ok(child) } } /// Create sandbox child process. /// /// This function uses `clone` to setup the sandbox's init process with user /// namespace isolations in place. /// /// Returns PID of the child process if successful. fn spawn_sandbox_init(init_arg: ProcessInitArg, allow_networking: bool) -> Result { unsafe { // Initialize child process stack memory. let stack_size = 1024 * 1024; let child_stack = libc::mmap( ptr::null_mut(), stack_size, libc::PROT_READ | libc::PROT_WRITE, libc::MAP_PRIVATE | libc::MAP_ANONYMOUS | libc::MAP_STACK, -1, 0, ); if child_stack == libc::MAP_FAILED { return Err(IoError::last_os_error().into()); } // Stack grows downward on all relevant Linux processors. let stack_top = child_stack.add(stack_size); // Construct clone flags with required namespaces. let mut flags = libc::CLONE_NEWIPC | libc::CLONE_NEWNS | libc::CLONE_NEWPID | libc::CLONE_NEWUSER; if !allow_networking { flags |= libc::CLONE_NEWNET; } // Spawn sandbox init process. let init_arg_raw = Box::into_raw(Box::new(init_arg)); let init_pid = libc::clone(sandbox_init, stack_top, flags | libc::SIGCHLD, init_arg_raw as _); if init_pid == -1 { Err(IoError::last_os_error().into()) } else { let mut init_arg = Box::from_raw(init_arg_raw); init_arg.pid = init_pid; Ok(*init_arg) } } } /// PID 1 inside the sandbox. /// /// This function is the entry point for the process which is used to launch the /// sandboxee and act as init system for the PID namespace. extern "C" fn sandbox_init(arg: *mut libc::c_void) -> libc::c_int { let init_arg: Box = unsafe { Box::from_raw(arg as _) }; match sandbox_init_inner(*init_arg) { Ok(exit_code) => exit_code, Err(err) => { eprintln!("sandboxing failure: {err}"); 1 }, } } /// PID 1 inside the sandbox. /// /// Wrapper to simplify error handling. fn sandbox_init_inner(mut init_arg: ProcessInitArg) -> io::Result { // Close all unused FDs. init_arg.stdin_tx.take(); init_arg.stdout_rx.take(); init_arg.stderr_rx.take(); drop(init_arg.exit_signal_rx); // Hook up stdio to parent process. if let Some(stdin_pipe) = &mut init_arg.stdin_rx { rustix::stdio::dup2_stdin(stdin_pipe)?; } if let Some(stdout_pipe) = &init_arg.stdout_tx { rustix::stdio::dup2_stdout(stdout_pipe)?; } if let Some(stderr_pipe) = &init_arg.stderr_tx { rustix::stdio::dup2_stderr(stderr_pipe)?; } // Map root UID and GID. namespaces::map_ids(init_arg.parent_euid.as_raw(), init_arg.parent_egid.as_raw(), 0, 0)?; // Isolate filesystem using a mount namespace. namespaces::setup_mount_namespace(init_arg.path_exceptions)?; // Create new procfs directory. let new_proc_c = CString::new("/proc")?; namespaces::mount_proc(&new_proc_c)?; // Drop root user mapping. namespaces::create_user_namespace( init_arg.parent_euid.as_raw(), init_arg.parent_egid.as_raw(), Namespaces::empty(), )?; // Setup system call filters. SyscallFilter::apply().map_err(|err| IoError::new(IoErrorKind::Other, err))?; // Block suid/sgid. // // This is also blocked by our bind mount's MS_NOSUID flag, so we're just // doubling-down here. rustix::thread::set_no_new_privs(true)?; // Spawn sandboxed process. let mut std_command = std::process::Command::from(init_arg.sandboxee); std_command.stdin(std::process::Stdio::inherit()); std_command.stdout(std::process::Stdio::inherit()); std_command.stderr(std::process::Stdio::inherit()); let child = std_command.spawn()?; // Reap zombie children. let child_pid = Pid::from_raw(child.id() as i32); loop { // Wait for any child to exit. match rustix::process::wait(WaitOptions::empty())? { Some((pid, status)) if Some(pid) == child_pid => match status.terminating_signal() { Some(signal) => { // Send exit signal to parent. rustix::io::write(init_arg.exit_signal_tx, &signal.to_le_bytes())?; return Ok(1); }, None => return Ok(status.exit_status().unwrap_or(1) as i32), }, Some(_) => (), None => unreachable!("none without nohang"), } } } /// Init process argument passed to `clone`. struct ProcessInitArg { path_exceptions: PathExceptions, sandboxee: Command, parent_euid: Uid, parent_egid: Gid, // FDs used by the child process. stdin_rx: Option, stdout_tx: Option, stderr_tx: Option, exit_signal_tx: OwnedFd, // FDs passed to the child for closing them. stdin_tx: Option, stdout_rx: Option, stderr_rx: Option, exit_signal_rx: OwnedFd, pid: i32, } impl ProcessInitArg { fn new( sandbox: LinuxSandbox, sandboxee: Command, exit_signal: (OwnedFd, OwnedFd), stdin: (Option, Option), stdout: (Option, Option), stderr: (Option, Option), ) -> Self { // Get EUID/EGID outside of the namespaces. let parent_euid = rustix::process::geteuid(); let parent_egid = rustix::process::getegid(); Self { parent_euid, parent_egid, sandboxee, path_exceptions: sandbox.path_exceptions, stdin_rx: stdin.0, stdout_tx: stdout.1, stderr_tx: stderr.1, exit_signal_tx: exit_signal.1, stdin_tx: stdin.1, stdout_rx: stdout.0, stderr_rx: stderr.0, exit_signal_rx: exit_signal.0, pid: -1, } } } /// Path permissions required for the sandbox. #[derive(Default)] pub(crate) struct PathExceptions { bind_mounts: HashMap, symlinks: Vec<(PathBuf, PathBuf)>, } impl PathExceptions { /// Add or modify a path's exceptions. /// /// This will add a new bind mount for the canonical path with the specified /// permission if it does not exist already. /// /// If the bind mount already exists, it will *ADD* the additional /// permissions. fn update(&mut self, path: PathBuf, write: bool, execute: bool) -> Result<()> { // Use canonical path for indexing. // // This ensures that a symlink and its target are treated like the same path for // exceptions. // // If the home path cannot be accessed, we ignore the exception. let canonical_path = match path.canonicalize() { Ok(path) => path, Err(_) => return Err(Error::InvalidPath(path)), }; // Store original symlink path to create it if necessary. if path_has_symlinks(&path) { // Normalize symlink's path. let absolute = absolute(&path)?; let normalized = normalize_path(&absolute); self.symlinks.push((normalized, canonical_path.clone())); } // Update bind mount's permission flags. let flags = self .bind_mounts .entry(canonical_path) .or_insert(MountAttrFlags::RDONLY | MountAttrFlags::NOEXEC); if write { flags.remove(MountAttrFlags::RDONLY); } if execute { flags.remove(MountAttrFlags::NOEXEC); } Ok(()) } } // Copied from Rust's STD: // https://github.com/rust-lang/rust/blob/42faef503f3e765120ca0ef06991337668eafc32/library/std/src/sys/unix/path.rs#L23C1-L63C2 // // Licensed under MIT: // https://github.com/rust-lang/rust/blob/master/LICENSE-MIT // /// Make a POSIX path absolute without changing its semantics. fn absolute(path: &Path) -> io::Result { // This is mostly a wrapper around collecting `Path::components`, with // exceptions made where this conflicts with the POSIX specification. // See 4.13 Pathname Resolution, IEEE Std 1003.1-2017 // https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13 // Get the components, skipping the redundant leading "." component if it // exists. let mut components = path.strip_prefix(".").unwrap_or(path).components(); let path_os = path.as_os_str().as_bytes(); let mut normalized = if path.is_absolute() { // "If a pathname begins with two successive characters, the // first component following the leading characters may be // interpreted in an implementation-defined manner, although more than // two leading characters shall be treated as a single // character." if path_os.starts_with(b"//") && !path_os.starts_with(b"///") { components.next(); PathBuf::from("//") } else { PathBuf::new() } } else { env::current_dir()? }; normalized.extend(components); // "Interfaces using pathname resolution may specify additional constraints // when a pathname that does not name an existing directory contains at // least one non- character and contains one or more trailing // characters". // A trailing is also meaningful if "a symbolic link is // encountered during pathname resolution". if path_os.ends_with(b"/") { normalized.push(""); } Ok(normalized) } /// Normalize path components, stripping out `.` and `..`. fn normalize_path(path: &Path) -> PathBuf { let mut normalized = PathBuf::new(); for component in path.components() { match component { Component::Prefix(_) => unreachable!("impl does not consider windows"), Component::RootDir => normalized.push("/"), Component::CurDir => continue, Component::ParentDir => { normalized.pop(); }, Component::Normal(segment) => normalized.push(segment), } } normalized } /// Check if a path contains any symlinks. fn path_has_symlinks(path: &Path) -> bool { path.ancestors().any(|path| path.read_link().is_ok()) } /// Get the number of threads used by the current process. fn thread_count() -> io::Result { // Read process status from procfs. let status = fs::read_to_string("/proc/self/status")?; // Parse procfs output. let (_, threads_start) = status.split_once("Threads:").ok_or_else(|| { io::Error::new(io::ErrorKind::InvalidData, "/proc/self/status missing \"Threads:\"") })?; let thread_count = threads_start.split_whitespace().next().ok_or_else(|| { io::Error::new(io::ErrorKind::InvalidData, "/proc/self/status output malformed") })?; // Convert to number. let thread_count = thread_count .parse::() .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?; Ok(thread_count) } ================================================ FILE: src/linux/namespaces.rs ================================================ //! Linux namespaces. use std::cmp::Ordering; use std::ffi::{CStr, CString}; use std::fs::{self, File}; use std::io::Error as IoError; use std::os::unix::ffi::OsStrExt; use std::os::unix::fs as unixfs; use std::path::{Component, Path, PathBuf}; use std::{env, io, mem, ptr}; use bitflags::bitflags; use crate::linux::PathExceptions; /// Path for mount namespace's new root. const NEW_ROOT: &str = "/tmp/birdcage-root"; /// Isolate filesystem access in an existing mount namespace. /// /// This will deny access to any path which isn't part of `bind_mounts`. Allowed /// paths are mounted according to their bind mount flags. pub(crate) fn setup_mount_namespace(exceptions: PathExceptions) -> io::Result<()> { // Get target paths for new and old root. let new_root = PathBuf::from(NEW_ROOT); // Ensure new root is available as an empty directory. if !new_root.exists() { fs::create_dir_all(&new_root)?; } // Create C-friendly versions for our paths. let new_root_c = CString::new(new_root.as_os_str().as_bytes()).unwrap(); // Create tmpfs mount for the new root, allowing pivot and ensuring directories // aren't created outside the sandbox. mount_tmpfs(&new_root_c)?; // Sort bind mounts by shortest length, to create parents before their children. let mut bind_mounts: Vec<_> = exceptions.bind_mounts.into_iter().collect(); bind_mounts.sort_unstable_by(|(a_path, a_flags), (b_path, b_flags)| { match a_path.components().count().cmp(&b_path.components().count()) { Ordering::Equal => (a_path, a_flags).cmp(&(b_path, b_flags)), ord => ord, } }); // Bind mount all allowed directories. for (path, flags) in bind_mounts { let src_c = CString::new(path.as_os_str().as_bytes()).unwrap(); // Get bind mount destination. let unrooted_path = path.strip_prefix("/").unwrap(); let dst = new_root.join(unrooted_path); let dst_c = CString::new(dst.as_os_str().as_bytes()).unwrap(); // Create mount target. if let Err(err) = copy_tree(&path, &new_root) { log::error!("skipping birdcage exception {path:?}: {err}"); continue; } // Bind path with full permissions. bind_mount(&src_c, &dst_c)?; // Remount to update permissions. update_mount_flags(&dst_c, flags | MountAttrFlags::NOSUID)?; } // Ensure original symlink paths are available. create_symlinks(&new_root, exceptions.symlinks)?; // Bind mount old procfs. let old_proc_c = CString::new("/proc").unwrap(); let new_proc = new_root.join("proc"); let new_proc_c = CString::new(new_proc.as_os_str().as_bytes()).unwrap(); fs::create_dir_all(&new_proc)?; bind_mount(&old_proc_c, &new_proc_c)?; // Pivot root to `new_root`, placing the old root at the same location. pivot_root(&new_root_c, &new_root_c)?; // Remove old root mounted at /, leaving only the new root at the same location. let root_c = CString::new("/").unwrap(); umount(&root_c)?; // Prevent child mount namespaces from accessing this namespace's mounts. deny_mount_propagation()?; Ok(()) } /// Create missing symlinks. /// /// If the parent directory of a symlink is mapped, we do not need to map the /// symlink ourselves and it's not possible to mount on top of it anyway. So /// here we make sure that symlinks are created if no bind mount was created for /// their parent directory. fn create_symlinks(new_root: &Path, symlinks: Vec<(PathBuf, PathBuf)>) -> io::Result<()> { for (symlink, target) in symlinks { // Ignore symlinks if a parent bind mount exists. let unrooted_path = symlink.strip_prefix("/").unwrap(); let dst = new_root.join(unrooted_path); if dst.symlink_metadata().is_ok() { continue; } // Create all parent directories. let parent = match symlink.parent() { Some(parent) => parent, None => continue, }; copy_tree(parent, new_root)?; // Create the symlink. unixfs::symlink(target, dst)?; } Ok(()) } /// Replicate a directory tree under a different directory. /// /// This will create all missing empty diretories and copy their permissions /// from the source tree. /// /// If `src` ends in a file, an empty file with matching permissions will be /// created. fn copy_tree(src: impl AsRef, dst: impl AsRef) -> io::Result<()> { let mut dst = dst.as_ref().to_path_buf(); let mut src_sub = PathBuf::new(); let src = src.as_ref(); for component in src.components() { // Append root only to source. if component == Component::RootDir { src_sub = src_sub.join(component); continue; } src_sub = src_sub.join(component); dst = dst.join(component); // Skip nodes that already exist. if dst.exists() { continue; } // Create target file/directory. let metadata = src_sub.metadata()?; if metadata.is_dir() { fs::create_dir(&dst)?; } else { File::create(&dst)?; } // Copy permissions. let permissions = metadata.permissions(); fs::set_permissions(&dst, permissions)?; } Ok(()) } /// Mount a new tmpfs. fn mount_tmpfs(dst: &CStr) -> io::Result<()> { let flags = MountFlags::empty(); let fstype = CString::new("tmpfs").unwrap(); let res = unsafe { libc::mount(ptr::null(), dst.as_ptr(), fstype.as_ptr(), flags.bits(), ptr::null()) }; if res == 0 { Ok(()) } else { Err(IoError::last_os_error()) } } /// Mount a new procfs. pub fn mount_proc(dst: &CStr) -> io::Result<()> { let flags = MountFlags::NOSUID | MountFlags::NODEV | MountFlags::NOEXEC; let fstype = CString::new("proc").unwrap(); let res = unsafe { libc::mount(fstype.as_ptr(), dst.as_ptr(), fstype.as_ptr(), flags.bits(), ptr::null()) }; if res == 0 { Ok(()) } else { Err(IoError::last_os_error()) } } /// Create a new bind mount. fn bind_mount(src: &CStr, dst: &CStr) -> io::Result<()> { let flags = MountFlags::BIND | MountFlags::RECURSIVE; let res = unsafe { libc::mount(src.as_ptr(), dst.as_ptr(), ptr::null(), flags.bits(), ptr::null()) }; if res == 0 { Ok(()) } else { Err(IoError::last_os_error()) } } /// Remount an existing bind mount with a new set of mount flags. fn update_mount_flags(mount: &CStr, flags: MountAttrFlags) -> io::Result<()> { let attrs = MountAttr { attr_set: flags.bits(), ..Default::default() }; let res = unsafe { libc::syscall( libc::SYS_mount_setattr, libc::AT_FDCWD, mount.as_ptr(), libc::AT_RECURSIVE, &attrs as *const _, mem::size_of::(), ) }; if res == 0 { Ok(()) } else { Err(IoError::last_os_error()) } } /// Recursively update the root to deny mount propagation. fn deny_mount_propagation() -> io::Result<()> { let flags = MountFlags::PRIVATE | MountFlags::RECURSIVE; let root = CString::new("/").unwrap(); let res = unsafe { libc::mount(ptr::null(), root.as_ptr(), ptr::null(), flags.bits(), ptr::null()) }; if res == 0 { Ok(()) } else { Err(IoError::last_os_error()) } } /// Change root directory to `new_root` and mount the old root in `put_old`. /// /// The `put_old` directory must be at or undearneath `new_root`. fn pivot_root(new_root: &CStr, put_old: &CStr) -> io::Result<()> { // Get target working directory path. let working_dir = env::current_dir().unwrap_or_else(|_| PathBuf::from("/")); let result = unsafe { libc::syscall(libc::SYS_pivot_root, new_root.as_ptr(), put_old.as_ptr()) }; if result != 0 { return Err(IoError::last_os_error()); } // Attempt to recover working directory, or switch to root. // // Without this, the user's working directory would stay the same, giving him // full access to it even if it is not bound. if env::set_current_dir(working_dir).is_err() { env::set_current_dir("/")?; } Ok(()) } /// Unmount a filesystem. fn umount(target: &CStr) -> io::Result<()> { let result = unsafe { libc::umount2(target.as_ptr(), libc::MNT_DETACH) }; match result { 0 => Ok(()), _ => Err(IoError::last_os_error()), } } /// Create a new user namespace. /// /// The parent and child UIDs and GIDs define the user and group mappings /// between the parent namespace and the new user namespace. pub fn create_user_namespace( child_uid: u32, child_gid: u32, extra_namespaces: Namespaces, ) -> io::Result<()> { // Get current user's EUID and EGID. let parent_euid = unsafe { libc::geteuid() }; let parent_egid = unsafe { libc::getegid() }; // Create the namespace. unshare(Namespaces::USER | extra_namespaces)?; // Map the UID and GID. map_ids(parent_euid, parent_egid, child_uid, child_gid)?; Ok(()) } /// Update /proc uid/gid maps. /// /// This should be called after creating a user namespace to ensure proper ID /// mappings. pub fn map_ids( parent_euid: u32, parent_egid: u32, child_uid: u32, child_gid: u32, ) -> io::Result<()> { let uid_map = format!("{child_uid} {parent_euid} 1\n"); let gid_map = format!("{child_gid} {parent_egid} 1\n"); fs::write("/proc/self/uid_map", uid_map.as_bytes())?; fs::write("/proc/self/setgroups", b"deny")?; fs::write("/proc/self/gid_map", gid_map.as_bytes())?; Ok(()) } /// Enter a namespace. fn unshare(namespaces: Namespaces) -> io::Result<()> { let result = unsafe { libc::unshare(namespaces.bits()) }; match result { 0 => Ok(()), _ => Err(IoError::last_os_error()), } } bitflags! { /// Mount syscall flags. #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] pub struct MountFlags: libc::c_ulong { /// Ignore suid and sgid bits. const NOSUID = libc::MS_NOSUID; /// Disallow access to device special files. const NODEV = libc::MS_NODEV; /// Disallow program execution. const NOEXEC = libc::MS_NOEXEC; /// Create a bind mount. const BIND = libc::MS_BIND; /// Used in conjuction with [`Self::BIND`] to create a recursive bind mount, and /// in conjuction with the propagation type flags to recursively change the /// propagation type of all of the mounts in a sub-tree. const RECURSIVE = libc::MS_REC; /// Make this mount private. Mount and unmount events do not propagate into or /// out of this mount. const PRIVATE = libc::MS_PRIVATE; /// Do not follow symbolic links when resolving paths. const NOSYMFOLLOW = 256; } } /// Parameter for the `mount_setattr` syscall. #[repr(C)] #[derive(Default)] struct MountAttr { attr_set: u64, attr_clr: u64, propagation: u64, userns_fd: u64, } bitflags! { /// Flags for the `mount_setattr` syscall. #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] pub struct MountAttrFlags: u64 { /// Mount read-only. const RDONLY = 0x00000001; /// Ignore suid and sgid bits. const NOSUID = 0x00000002; /// Disallow access to device special files. const NODEV = 0x00000004; /// Disallow program execution. const NOEXEC = 0x00000008; /// Setting on how atime should be updated. const _ATIME = 0x00000070; /// - Update atime relative to mtime/ctime. const RELATI = 0x00000000; /// - Do not update access times. const NOATIM = 0x00000010; /// - Always perform atime updates. const STRICTATIME = 0x00000020; /// Do not update directory access times. const NODIRATIME = 0x00000080; /// Idmap mount to @userns_fd in struct mount_attr. const IDMAP = 0x00100000; /// Do not follow symlinks. const NOSYMFOLLOW = 0x00200000; } } bitflags! { /// Unshare system call namespace flags. #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] pub struct Namespaces: libc::c_int { /// Unshare the file descriptor table, so that the calling process no longer /// shares its file descriptors with any other process. const FILES = libc::CLONE_FILES; /// Unshare filesystem attributes, so that the calling process no longer shares /// its root directory, current directory, or umask attributes with any other process. const FS = libc::CLONE_FS; /// Unshare the cgroup namespace. const CGROUP = libc::CLONE_NEWCGROUP; /// Unshare the IPC namespace, so that the calling process has a private copy of /// the IPC namespace which is not shared with any other process. Specifying /// this flag automatically implies [`Namespaces::SYSVSEM`] as well. const IPC = libc::CLONE_NEWIPC; /// Unshare the network namespace, so that the calling process is moved into a /// new network namespace which is not shared with any previously existing process. const NETWORK = libc::CLONE_NEWNET; /// Unshare the mount namespace, so that the calling process has a private copy /// of its namespace which is not shared with any other process. Specifying this /// flag automatically implies [`Namespaces::FS`] as well. const MOUNT = libc::CLONE_NEWNS; /// Unshare the PID namespace, so that the calling process has a new PID /// namespace for its children which is not shared with any previously existing /// process. The calling process is **not** moved into the new namespace. The /// first child created by the calling process will have the process ID 1 and /// will assume the role of init in the new namespace. Specifying this flag /// automatically implies [`libc::CLONE_THREAD`] as well. const PID = libc::CLONE_NEWPID; /// Unshare the time namespace, so that the calling process has a new time /// namespace for its children which is not shared with any previously existing /// process. The calling process is **not** moved into the new namespace. const TIME = 0x80; /// Unshare the user namespace, so that the calling process is moved into a new /// user namespace which is not shared with any previously existing process. The /// caller obtains a full set of capabilities in the new namespace. /// /// Requires that the calling process is not threaded; specifying this flag /// automatically implies [`libc::CLONE_THREAD`] and [`Namespaces::FS`] as well. const USER = libc::CLONE_NEWUSER; /// Unshare the UTS IPC namespace, so that the calling process has a private /// copy of the UTS namespace which is not shared with any other process. const UTS = libc::CLONE_NEWUTS; /// Unshare System V semaphore adjustment (semadj) values, so that the calling /// process has a new empty semadj list that is not shared with any other /// process. If this is the last process that has a reference to the process's /// current semadj list, then the adjustments in that list are applied to the /// corresponding semaphores const SYSVSEM = libc::CLONE_SYSVSEM; } } ================================================ FILE: src/linux/seccomp.rs ================================================ //! Seccomp system call filtering. use std::collections::BTreeMap; use seccompiler::{ BpfProgram, SeccompAction, SeccompCmpArgLen, SeccompCmpOp, SeccompCondition, SeccompFilter, SeccompRule, TargetArch, }; use crate::Result; #[cfg(target_arch = "x86_64")] const ARCH: TargetArch = TargetArch::x86_64; #[cfg(target_arch = "aarch64")] const ARCH: TargetArch = TargetArch::aarch64; /// Bitmask for the clone syscall seccomp filter. /// /// A 1 in the bitmask means system calls with this flag set will be denied. /// /// Filtered flags: /// - CLONE_NEWNS = 0x00020000 /// - CLONE_NEWCGROUP = 0x02000000 /// - CLONE_NEWUTS = 0x04000000 /// - CLONE_NEWIPC = 0x08000000 /// - CLONE_NEWUSER = 0x10000000 /// - CLONE_NEWPID = 0x20000000 /// - CLONE_NEWNET = 0x40000000 const CLONE_NAMESPACE_FILTER: u32 = 0b01111110000000100000000000000000; /// Seccomp system call filter. /// /// This filter is aimed at restricting system calls which shouldn't be /// executable by an untrusted client. #[derive(Default)] pub struct SyscallFilter; impl SyscallFilter { /// Apply the seccomp filter. pub fn apply() -> Result<()> { let mut rules = BTreeMap::new(); // Add exceptions for allowed syscalls. for syscall in SYSCALL_WHITELIST { rules.insert(*syscall, Vec::new()); } // Add exception for the `clone` syscall. let allow_clone = SeccompCondition::new( 0, SeccompCmpArgLen::Qword, SeccompCmpOp::MaskedEq(CLONE_NAMESPACE_FILTER as u64), 0, )?; let clone_rule = SeccompRule::new(vec![allow_clone])?; rules.insert(libc::SYS_clone, vec![clone_rule]); // Apply seccomp filter. let filter = SeccompFilter::new( rules, // Action performed if no rule matches. SeccompAction::Errno(libc::EACCES as u32), // Action performed if any rule matches. SeccompAction::Allow, ARCH, )?; let program: BpfProgram = filter.try_into()?; seccompiler::apply_filter(&program)?; // Change `clone3` syscall error to "not implemented", to force `clone` usage. let mut rules = BTreeMap::new(); rules.insert(libc::SYS_clone3, Vec::new()); let filter = SeccompFilter::new( rules, // Action performed if no rule matches. SeccompAction::Allow, // Action performed if any rule matches. SeccompAction::Errno(libc::ENOSYS as u32), ARCH, )?; let program: BpfProgram = filter.try_into()?; seccompiler::apply_filter(&program)?; Ok(()) } } /// Unconditionally allowed syscalls for networking. const SYSCALL_WHITELIST: &[libc::c_long] = &[ libc::SYS_read, libc::SYS_write, #[cfg(target_arch = "x86_64")] libc::SYS_open, libc::SYS_close, #[cfg(target_arch = "x86_64")] libc::SYS_stat, libc::SYS_fstat, #[cfg(target_arch = "x86_64")] libc::SYS_lstat, #[cfg(target_arch = "x86_64")] libc::SYS_poll, libc::SYS_lseek, libc::SYS_mmap, libc::SYS_mprotect, libc::SYS_munmap, libc::SYS_brk, libc::SYS_rt_sigaction, libc::SYS_rt_sigprocmask, libc::SYS_rt_sigreturn, libc::SYS_ioctl, libc::SYS_pread64, libc::SYS_pwrite64, libc::SYS_readv, libc::SYS_writev, #[cfg(target_arch = "x86_64")] libc::SYS_access, #[cfg(target_arch = "x86_64")] libc::SYS_pipe, #[cfg(target_arch = "x86_64")] libc::SYS_select, libc::SYS_sched_yield, libc::SYS_mremap, libc::SYS_msync, libc::SYS_mincore, libc::SYS_madvise, libc::SYS_shmget, libc::SYS_shmat, libc::SYS_shmctl, libc::SYS_dup, #[cfg(target_arch = "x86_64")] libc::SYS_dup2, #[cfg(target_arch = "x86_64")] libc::SYS_pause, libc::SYS_nanosleep, libc::SYS_getitimer, #[cfg(target_arch = "x86_64")] libc::SYS_alarm, libc::SYS_setitimer, libc::SYS_getpid, #[cfg(target_arch = "x86_64")] libc::SYS_sendfile, libc::SYS_connect, libc::SYS_accept, libc::SYS_sendto, libc::SYS_recvfrom, libc::SYS_sendmsg, libc::SYS_recvmsg, libc::SYS_shutdown, libc::SYS_bind, libc::SYS_listen, libc::SYS_getsockname, libc::SYS_getpeername, libc::SYS_setsockopt, libc::SYS_getsockopt, #[cfg(target_arch = "x86_64")] libc::SYS_fork, #[cfg(target_arch = "x86_64")] libc::SYS_vfork, libc::SYS_execve, libc::SYS_exit, libc::SYS_wait4, libc::SYS_kill, libc::SYS_uname, libc::SYS_semget, libc::SYS_semop, libc::SYS_semctl, libc::SYS_shmdt, libc::SYS_msgget, libc::SYS_msgsnd, libc::SYS_msgrcv, libc::SYS_msgctl, libc::SYS_fcntl, libc::SYS_flock, libc::SYS_fsync, libc::SYS_fdatasync, libc::SYS_truncate, libc::SYS_ftruncate, #[cfg(target_arch = "x86_64")] libc::SYS_getdents, libc::SYS_getcwd, libc::SYS_chdir, libc::SYS_fchdir, #[cfg(target_arch = "x86_64")] libc::SYS_rename, #[cfg(target_arch = "x86_64")] libc::SYS_mkdir, #[cfg(target_arch = "x86_64")] libc::SYS_rmdir, #[cfg(target_arch = "x86_64")] libc::SYS_creat, #[cfg(target_arch = "x86_64")] libc::SYS_link, #[cfg(target_arch = "x86_64")] libc::SYS_unlink, #[cfg(target_arch = "x86_64")] libc::SYS_symlink, #[cfg(target_arch = "x86_64")] libc::SYS_readlink, #[cfg(target_arch = "x86_64")] libc::SYS_chmod, libc::SYS_fchmod, #[cfg(target_arch = "x86_64")] libc::SYS_chown, libc::SYS_fchown, #[cfg(target_arch = "x86_64")] libc::SYS_lchown, libc::SYS_umask, libc::SYS_gettimeofday, libc::SYS_getrlimit, libc::SYS_getrusage, libc::SYS_sysinfo, libc::SYS_times, libc::SYS_getuid, libc::SYS_getgid, libc::SYS_setuid, libc::SYS_setgid, libc::SYS_geteuid, libc::SYS_getegid, libc::SYS_setpgid, libc::SYS_getppid, #[cfg(target_arch = "x86_64")] libc::SYS_getpgrp, libc::SYS_setsid, libc::SYS_setreuid, libc::SYS_setregid, libc::SYS_getgroups, libc::SYS_setgroups, libc::SYS_setresuid, libc::SYS_getresuid, libc::SYS_setresgid, libc::SYS_getresgid, libc::SYS_getpgid, libc::SYS_setfsuid, libc::SYS_setfsgid, libc::SYS_getsid, libc::SYS_capget, libc::SYS_capset, libc::SYS_rt_sigpending, libc::SYS_rt_sigtimedwait, libc::SYS_rt_sigqueueinfo, libc::SYS_rt_sigsuspend, libc::SYS_sigaltstack, #[cfg(target_arch = "x86_64")] libc::SYS_utime, #[cfg(target_arch = "x86_64")] libc::SYS_mknod, libc::SYS_statfs, libc::SYS_fstatfs, libc::SYS_getpriority, libc::SYS_setpriority, libc::SYS_sched_setparam, libc::SYS_sched_getparam, libc::SYS_sched_setscheduler, libc::SYS_sched_getscheduler, libc::SYS_sched_get_priority_max, libc::SYS_sched_get_priority_min, libc::SYS_sched_rr_get_interval, libc::SYS_mlock, libc::SYS_munlock, libc::SYS_mlockall, libc::SYS_munlockall, #[cfg(target_arch = "x86_64")] libc::SYS_modify_ldt, libc::SYS_prctl, #[cfg(target_arch = "x86_64")] libc::SYS_arch_prctl, libc::SYS_adjtimex, libc::SYS_setrlimit, libc::SYS_sync, libc::SYS_gettid, libc::SYS_readahead, libc::SYS_setxattr, libc::SYS_lsetxattr, libc::SYS_fsetxattr, libc::SYS_getxattr, libc::SYS_lgetxattr, libc::SYS_fgetxattr, libc::SYS_listxattr, libc::SYS_llistxattr, libc::SYS_flistxattr, libc::SYS_removexattr, libc::SYS_lremovexattr, libc::SYS_fremovexattr, libc::SYS_tkill, #[cfg(target_arch = "x86_64")] libc::SYS_time, libc::SYS_futex, libc::SYS_sched_setaffinity, libc::SYS_sched_getaffinity, #[cfg(target_arch = "x86_64")] libc::SYS_set_thread_area, libc::SYS_io_setup, libc::SYS_io_destroy, libc::SYS_io_getevents, libc::SYS_io_submit, libc::SYS_io_cancel, #[cfg(target_arch = "x86_64")] libc::SYS_get_thread_area, #[cfg(target_arch = "x86_64")] libc::SYS_epoll_create, #[cfg(target_arch = "x86_64")] libc::SYS_epoll_ctl_old, #[cfg(target_arch = "x86_64")] libc::SYS_epoll_wait_old, libc::SYS_remap_file_pages, libc::SYS_getdents64, libc::SYS_set_tid_address, libc::SYS_restart_syscall, libc::SYS_semtimedop, #[cfg(target_arch = "x86_64")] libc::SYS_fadvise64, libc::SYS_timer_create, libc::SYS_timer_settime, libc::SYS_timer_gettime, libc::SYS_timer_getoverrun, libc::SYS_timer_delete, libc::SYS_clock_gettime, libc::SYS_clock_getres, libc::SYS_clock_nanosleep, libc::SYS_exit_group, #[cfg(target_arch = "x86_64")] libc::SYS_epoll_wait, libc::SYS_epoll_ctl, libc::SYS_tgkill, #[cfg(target_arch = "x86_64")] libc::SYS_utimes, libc::SYS_mq_open, libc::SYS_mq_unlink, libc::SYS_mq_timedsend, libc::SYS_mq_timedreceive, libc::SYS_mq_notify, libc::SYS_mq_getsetattr, libc::SYS_waitid, libc::SYS_ioprio_set, libc::SYS_ioprio_get, #[cfg(target_arch = "x86_64")] libc::SYS_inotify_init, libc::SYS_inotify_add_watch, libc::SYS_inotify_rm_watch, libc::SYS_migrate_pages, libc::SYS_openat, libc::SYS_mkdirat, libc::SYS_mknodat, libc::SYS_fchownat, #[cfg(target_arch = "x86_64")] libc::SYS_futimesat, libc::SYS_newfstatat, libc::SYS_unlinkat, libc::SYS_renameat, libc::SYS_linkat, libc::SYS_symlinkat, libc::SYS_readlinkat, libc::SYS_fchmodat, libc::SYS_faccessat, libc::SYS_pselect6, libc::SYS_ppoll, libc::SYS_set_robust_list, libc::SYS_get_robust_list, libc::SYS_splice, libc::SYS_tee, libc::SYS_sync_file_range, libc::SYS_vmsplice, libc::SYS_utimensat, libc::SYS_epoll_pwait, #[cfg(target_arch = "x86_64")] libc::SYS_signalfd, libc::SYS_timerfd_create, #[cfg(target_arch = "x86_64")] libc::SYS_eventfd, libc::SYS_fallocate, libc::SYS_timerfd_settime, libc::SYS_timerfd_gettime, libc::SYS_accept4, libc::SYS_signalfd4, libc::SYS_eventfd2, libc::SYS_epoll_create1, libc::SYS_dup3, libc::SYS_pipe2, libc::SYS_inotify_init1, libc::SYS_preadv, libc::SYS_pwritev, libc::SYS_rt_tgsigqueueinfo, libc::SYS_recvmmsg, libc::SYS_fanotify_mark, libc::SYS_prlimit64, libc::SYS_name_to_handle_at, libc::SYS_syncfs, libc::SYS_sendmmsg, libc::SYS_getcpu, libc::SYS_sched_setattr, libc::SYS_sched_getattr, libc::SYS_renameat2, libc::SYS_seccomp, libc::SYS_getrandom, libc::SYS_memfd_create, libc::SYS_execveat, libc::SYS_membarrier, libc::SYS_mlock2, libc::SYS_copy_file_range, libc::SYS_preadv2, libc::SYS_pwritev2, libc::SYS_pkey_mprotect, libc::SYS_pkey_alloc, libc::SYS_pkey_free, libc::SYS_statx, libc::SYS_rseq, libc::SYS_pidfd_send_signal, libc::SYS_pidfd_open, libc::SYS_close_range, libc::SYS_openat2, libc::SYS_faccessat2, libc::SYS_epoll_pwait2, libc::SYS_landlock_create_ruleset, libc::SYS_landlock_add_rule, libc::SYS_landlock_restrict_self, libc::SYS_memfd_secret, libc::SYS_process_mrelease, libc::SYS_futex_waitv, libc::SYS_socketpair, libc::SYS_socket, libc::SYS_io_uring_enter, libc::SYS_io_uring_register, libc::SYS_io_uring_setup, ]; ================================================ FILE: src/macos.rs ================================================ //! Linux sandboxing. //! //! This module implements sandboxing on macOS using `sandbox_init`. use std::collections::HashMap; use std::ffi::{CStr, CString}; use std::io::{Result as IoResult, Write}; use std::path::{Path, PathBuf}; use std::{fs, ptr}; use bitflags::bitflags; use crate::error::{Error, Result}; use crate::{Child, Command, Exception, Sandbox}; /// Deny-all fallback rule. static DEFAULT_RULE: &[u8] = b"\ (version 1) (import \"system.sb\") (deny default) (allow mach*) (allow ipc*) (allow signal (target others)) (allow process-fork) (allow sysctl*) (allow system*) (allow file-read-metadata) (system-network) "; /// macOS sandboxing based on Seatbelt. #[derive(Default)] pub struct MacSandbox { path_exceptions: HashMap, env_exceptions: Vec, net_exception: bool, full_env: bool, } impl Sandbox for MacSandbox { fn new() -> Self { Self::default() } fn add_exception(&mut self, exception: Exception) -> Result<&mut Self> { match exception { Exception::Read(path) => self.update_path_exceptions(path, PathException::READ)?, Exception::WriteAndRead(path) => { self.update_path_exceptions(path, PathException::WRITE | PathException::READ)? }, Exception::ExecuteAndRead(path) => { self.update_path_exceptions(path, PathException::EXECUTE | PathException::READ)? }, Exception::Networking => self.net_exception = true, Exception::Environment(key) => { self.env_exceptions.push(key); return Ok(self); }, Exception::FullEnvironment => { self.full_env = true; return Ok(self); }, } Ok(self) } fn spawn(self, mut sandboxee: Command) -> Result { // Remove environment variables. if !self.full_env { crate::restrict_env_variables(&self.env_exceptions); } // Create the seatbelt sandbox profile. let profile = self.create_profile()?; let profile = CString::new(profile).map_err(|_| Error::ActivationFailed("invalid profile".into()))?; let mut error = ptr::null_mut(); let result = unsafe { sandbox_init(profile.as_ptr(), 0, &mut error) }; if result == 0 { Ok(sandboxee.spawn()?) } else { unsafe { let error_text = CStr::from_ptr(error) .to_str() .map_err(|_| Error::ActivationFailed("sandbox_init failed".into()))? .to_owned(); sandbox_free_error(error); Err(Error::ActivationFailed(error_text)) } } } } impl MacSandbox { /// Add or modify a path's exceptions. fn update_path_exceptions(&mut self, path: PathBuf, exceptions: PathException) -> Result<()> { // Canonicalize all exception paths. // // Since the macOS sandbox only cares about permissions for symlink targets, due // to the `(allow file-read-metadata)` rule, we don't need to bother with // keeping the original paths. let escaped_path = escape_path(&path)?; let exception = self.path_exceptions.entry(escaped_path).or_insert(PathException::empty()); exception.insert(exceptions); Ok(()) } /// Create a seatbelt profile for the requested sandbox configuration. fn create_profile(&self) -> Result> { let mut profile = DEFAULT_RULE.to_vec(); // Sort by component count to ensure parent paths appear before descendants. let mut path_exceptions: Vec<_> = self.path_exceptions.iter().collect(); path_exceptions.sort_unstable_by(|a, b| a.0.len().cmp(&b.0.len())); for (path, exception) in path_exceptions { // Deny all access to clear existing permission grants. Self::revoke_path_access(&mut profile, path)?; if exception.contains(PathException::READ) { let rule = PathRule::new(RuleMode::Allow, "file-read*", path.into()); rule.write_to(&mut profile)?; } if exception.contains(PathException::WRITE) { let rule = PathRule::new(RuleMode::Allow, "file-write*", path.into()); rule.write_to(&mut profile)?; } if exception.contains(PathException::EXECUTE) { let rule = PathRule::new(RuleMode::Allow, "process-exec", path.into()); rule.write_to(&mut profile)?; } } if self.net_exception { profile.write_all(b"(allow network*)\n")?; } Ok(profile) } /// Revoke all access permisisons for a path. /// /// This is necessary to grant more restrictive permissions to a child of a /// directory which was previously granted permissions. fn revoke_path_access(buffer: &mut Vec, path: &str) -> Result<()> { let rule = PathRule::new(RuleMode::Deny, "file-read*", path.into()); rule.write_to(buffer)?; let rule = PathRule::new(RuleMode::Deny, "file-write*", path.into()); rule.write_to(buffer)?; let rule = PathRule::new(RuleMode::Deny, "process-exec", path.into()); rule.write_to(buffer)?; Ok(()) } } struct PathRule { mode: RuleMode, access_type: &'static str, path: String, } impl PathRule { fn new(mode: RuleMode, access_type: &'static str, path: String) -> Self { Self { mode, access_type, path } } /// Write this rule to a profile. fn write_to(&self, buffer: &mut Vec) -> IoResult<()> { buffer.write_all(b"(")?; buffer.write_all(self.mode.as_str().as_bytes())?; buffer.write_all(b" ")?; buffer.write_all(self.access_type.as_bytes())?; buffer.write_all(b" (subpath ")?; buffer.write_all(self.path.as_bytes())?; buffer.write_all(b"))\n")?; Ok(()) } } /// Mode for a seatbelt rule. enum RuleMode { Allow, Deny, } impl RuleMode { fn as_str(&self) -> &str { match self { Self::Allow => "allow", Self::Deny => "deny", } } } bitflags! { /// Types of sandbox filesystem exceptions. struct PathException: u8 { const EXECUTE = 0b0001; const WRITE = 0b0010; const READ = 0b0100; } } /// Escape a path: /tt/in\a"x -> "/tt/in\\a\"x" fn escape_path(path: &Path) -> Result { // Canonicalize the incoming path to support relative paths. // The `subpath` action only allows absolute paths. let canonical_path = fs::canonicalize(&path).map_err(|_| Error::InvalidPath(path.to_path_buf()))?; let mut path_str = canonical_path .into_os_string() .into_string() .map_err(|_| Error::InvalidPath(path.to_path_buf()))?; // Paths in `subpath` expressions must not end with /. while path_str.ends_with('/') && path_str != "/" { String::pop(&mut path_str); } path_str = path_str.replace('"', r#"\""#); path_str = path_str.replace('\\', r#"\\"#); Ok(format!("\"{path_str}\"")) } extern "C" { fn sandbox_init(profile: *const i8, flags: u64, errorbuf: *mut *mut i8) -> i32; fn sandbox_free_error(errorbuf: *mut i8); } ================================================ FILE: src/process/linux.rs ================================================ //! Linux process implementation. //! //! Documentation in this module has been largely copied from [STD] and is //! thus dual-licensed under MIT and Apache. //! //! [STD]: https://doc.rust-lang.org/std/process/index.html use std::ffi::{OsStr, OsString}; use std::io::{self, Read, Write}; use std::mem; use std::os::fd::{AsRawFd, OwnedFd, RawFd}; use std::os::unix::ffi::OsStrExt; use std::os::unix::process::ExitStatusExt; pub use std::process::{ExitStatus, Output}; use rustix::fs::{Mode, OFlags}; use rustix::pipe::pipe; use rustix::process::{Pid, Signal}; /// A process builder, providing fine-grained control /// over how a new process should be spawned. /// /// A default configuration can be generated using `Command::new(program)`, /// where `program` gives a path to the program to be executed. Additional /// builder methods allow the configuration to be changed (for example, by /// adding arguments) prior to spawning: /// /// ```no_run /// use birdcage::process::Command; /// /// Command::new("sh").arg("-c").arg("echo hello"); /// ``` pub struct Command { program: OsString, args: Vec, pub(crate) stdin: Stdio, pub(crate) stdout: Stdio, pub(crate) stderr: Stdio, } impl Command { /// Constructs a new `Command` for launching the program at /// path `program`, with the following default configuration: /// /// * No arguments to the program /// * Inherit the current process's working directory /// * Inherit stdin/stdout/stderr /// /// Builder methods are provided to change these defaults and /// otherwise configure the process. /// /// If `program` is not an absolute path, the `PATH` will be searched in /// an OS-defined way. /// /// # Examples /// /// Basic usage: /// /// ```no_run /// use birdcage::process::Command; /// /// Command::new("sh"); /// ``` pub fn new>(program: S) -> Self { let program = program.as_ref().to_os_string(); Self { program, stdout: Default::default(), stderr: Default::default(), stdin: Default::default(), args: Default::default(), } } /// Adds an argument to pass to the program. /// /// Only one argument can be passed per use. So instead of: /// /// ```no_run /// # birdcage::process::Command::new("sh") /// .arg("-C /path/to/repo") /// # ; /// ``` /// /// usage would be: /// /// ```no_run /// # birdcage::process::Command::new("sh") /// .arg("-C") /// .arg("/path/to/repo") /// # ; /// ``` /// /// To pass multiple arguments see [`args`]. /// /// [`args`]: Command::args /// /// Note that the argument is not passed through a shell, but given /// literally to the program. This means that shell syntax like quotes, /// escaped characters, word splitting, glob patterns, variable /// substitution, etc. have no effect. /// /// # Examples /// /// Basic usage: /// /// ```no_run /// use birdcage::process::Command; /// /// Command::new("ls").arg("-l").arg("-a"); /// ``` pub fn arg>(&mut self, arg: S) -> &mut Self { let arg = arg.as_ref().to_os_string(); self.args.push(arg); self } /// Adds multiple arguments to pass to the program. /// /// To pass a single argument see [`arg`]. /// /// [`arg`]: Command::arg /// /// Note that the arguments are not passed through a shell, but given /// literally to the program. This means that shell syntax like quotes, /// escaped characters, word splitting, glob patterns, variable /// substitution, etc. have no effect. /// /// # Examples /// /// Basic usage: /// /// ```no_run /// use birdcage::process::Command; /// /// Command::new("ls").args(["-l", "-a"]); /// ``` pub fn args(&mut self, args: I) -> &mut Self where I: IntoIterator, S: AsRef, { for arg in args { let arg = arg.as_ref().to_os_string(); self.args.push(arg); } self } /// Configuration for the child process's standard input (stdin) handle. /// /// Defaults to [`inherit`]. /// /// [`inherit`]: Stdio::inherit /// /// # Examples /// /// Basic usage: /// /// ```no_run /// use birdcage::process::{Command, Stdio}; /// /// Command::new("ls").stdin(Stdio::null()); /// ``` pub fn stdin>(&mut self, cfg: T) -> &mut Self { self.stdin = cfg.into(); self } /// Configuration for the child process's standard output (stdout) handle. /// /// Defaults to [`inherit`]. /// /// [`inherit`]: Stdio::inherit /// /// # Examples /// /// Basic usage: /// /// ```no_run /// use birdcage::process::{Command, Stdio}; /// /// Command::new("ls").stdout(Stdio::null()); /// ``` pub fn stdout>(&mut self, cfg: T) -> &mut Self { self.stdout = cfg.into(); self } /// Configuration for the child process's standard error (stderr) handle. /// /// Defaults to [`inherit`]. /// /// [`inherit`]: Stdio::inherit /// /// # Examples /// /// Basic usage: /// /// ```no_run /// use birdcage::process::{Command, Stdio}; /// /// Command::new("ls").stderr(Stdio::null()); /// ``` pub fn stderr>(&mut self, cfg: T) -> &mut Self { self.stderr = cfg.into(); self } /// Returns the path to the program that was given to [`Command::new`]. /// /// # Examples /// /// ``` /// use birdcage::process::Command; /// /// let cmd = Command::new("echo"); /// assert_eq!(cmd.get_program(), "echo"); /// ``` pub fn get_program(&self) -> &OsStr { OsStr::from_bytes(self.program.as_bytes()) } } impl From for std::process::Command { fn from(command: Command) -> Self { let mut std_command = std::process::Command::new(command.program); std_command.args(command.args); let stdin: Option = command.stdin.into(); if let Some(stdin) = stdin { std_command.stdin(stdin); } let stdout: Option = command.stdout.into(); if let Some(stdout) = stdout { std_command.stdout(stdout); } let stderr: Option = command.stderr.into(); if let Some(stderr) = stderr { std_command.stderr(stderr); } std_command } } /// Representation of a running or exited child process. /// /// This structure is used to represent and manage child processes. A child /// process is created via the [`Command`] struct, which configures the /// spawning process and can itself be constructed using a builder-style /// interface. /// /// There is no implementation of [`Drop`] for child processes, /// so if you do not ensure the `Child` has exited then it will continue to /// run, even after the `Child` handle to the child process has gone out of /// scope. /// /// Calling [`wait`] (or other functions that wrap around it) will make /// the parent process wait until the child has actually exited before /// continuing. /// /// # Warning /// /// On some systems, calling [`wait`] or similar is necessary for the OS to /// release resources. A process that terminated but has not been waited on is /// still around as a "zombie". Leaving too many zombies around may exhaust /// global resources (for example process IDs). /// /// Birdcage does *not* automatically wait on child processes (not even if the /// `Child` is dropped), it is up to the application developer to do so. As a /// consequence, dropping `Child` handles without waiting on them first is not /// recommended in long-running applications. /// /// # Examples /// /// ```should_panic /// use birdcage::process::Command; /// use birdcage::{Birdcage, Sandbox}; /// /// let mut cmd = Command::new("/bin/cat"); /// cmd.arg("file.txt"); /// let mut child = Birdcage::new().spawn(cmd).expect("failed to execute child"); /// /// let ecode = child.wait().expect("failed to wait on child"); /// /// assert!(ecode.success()); /// ``` /// /// [`wait`]: Child::wait pub struct Child { /// The handle for writing to the child's standard input (stdin), if it /// has been captured. You might find it helpful to do /// /// ```compile_fail,E0425 /// let stdin = child.stdin.take().unwrap(); /// ``` /// /// to avoid partially moving the `child` and thus blocking yourself from /// calling functions on `child` while using `stdin`. pub stdin: Option, /// The handle for reading from the child's standard output (stdout), if it /// has been captured. You might find it helpful to do /// /// ```compile_fail,E0425 /// let stdout = child.stdout.take().unwrap(); /// ``` /// /// to avoid partially moving the `child` and thus blocking yourself from /// calling functions on `child` while using `stdout`. pub stdout: Option, /// The handle for reading from the child's standard error (stderr), if it /// has been captured. You might find it helpful to do /// /// ```compile_fail,E0425 /// let stderr = child.stderr.take().unwrap(); /// ``` /// /// to avoid partially moving the `child` and thus blocking yourself from /// calling functions on `child` while using `stderr`. pub stderr: Option, exit_signal: OwnedFd, pid: u32, } impl Child { /// Create child from a process and its Stdio pipes. pub(crate) fn new( pid: i32, exit_signal: OwnedFd, stdin: Option, stdout: Option, stderr: Option, ) -> io::Result { Ok(Self { exit_signal, pid: pid as u32, stdin: stdin.map(ChildStdin::new).transpose()?, stdout: stdout.map(ChildStdout::new).transpose()?, stderr: stderr.map(ChildStderr::new).transpose()?, }) } /// Forces the child process to exit. If the child has already exited, /// `Ok(())` is returned. /// /// The mapping to [`ErrorKind`]s is not part of the compatibility contract /// of the function. /// /// This is equivalent to sending a SIGKILL. /// /// # Examples /// /// Basic usage: /// /// ```no_run /// use birdcage::process::Command; /// use birdcage::{Birdcage, Sandbox}; /// /// let command = Command::new("yes"); /// if let Ok(mut child) = Birdcage::new().spawn(command) { /// child.kill().expect("command couldn't be killed"); /// } else { /// println!("yes command didn't start"); /// } /// ``` /// /// [`ErrorKind`]: io::ErrorKind /// [`InvalidInput`]: io::ErrorKind::InvalidInput pub fn kill(&mut self) -> io::Result<()> { let pid = Pid::from_raw(self.pid as i32).unwrap(); rustix::process::kill_process(pid, Signal::Kill)?; Ok(()) } /// Returns the OS-assigned process identifier associated with this child. /// /// # Examples /// /// Basic usage: /// /// ```no_run /// use birdcage::process::Command; /// use birdcage::{Birdcage, Sandbox}; /// /// let command = Command::new("ls"); /// if let Ok(child) = Birdcage::new().spawn(command) { /// println!("Child's ID is {}", child.id()); /// } else { /// println!("ls command didn't start"); /// } /// ``` pub fn id(&self) -> u32 { self.pid } /// Waits for the child to exit completely, returning the status that it /// exited with. This function will continue to have the same return value /// after it has been called at least once. /// /// The stdin handle to the child process, if any, will be closed /// before waiting. This helps avoid deadlock: it ensures that the /// child does not block waiting for input from the parent, while /// the parent waits for the child to exit. /// /// # Examples /// /// Basic usage: /// /// ```no_run /// use birdcage::process::Command; /// use birdcage::{Birdcage, Sandbox}; /// /// let mut command = Command::new("ls"); /// if let Ok(mut child) = Birdcage::new().spawn(command) { /// child.wait().expect("command wasn't running"); /// println!("Child has finished its execution!"); /// } else { /// println!("ls command didn't start"); /// } /// ``` pub fn wait(&mut self) -> io::Result { // Wait for child process to exit. unsafe { let mut status: libc::c_int = 0; if libc::waitpid(self.pid as i32, &mut status, 0) == -1 { Err(io::Error::last_os_error()) } else { match self.exit_signal()? { Some(exit_signal) => Ok(exit_signal), None => Ok(ExitStatus::from_raw(status)), } } } } /// Attempts to collect the exit status of the child if it has already /// exited. /// /// This function will not block the calling thread and will only /// check to see if the child process has exited or not. If the child has /// exited then on Unix the process ID is reaped. This function is /// guaranteed to repeatedly return a successful exit status so long as the /// child has already exited. /// /// If the child has exited, then `Ok(Some(status))` is returned. If the /// exit status is not available at this time then `Ok(None)` is returned. /// If an error occurs, then that error is returned. /// /// Note that unlike `wait`, this function will not attempt to drop stdin. /// /// # Examples /// /// Basic usage: /// /// ```no_run /// use birdcage::process::Command; /// use birdcage::{Birdcage, Sandbox}; /// /// let cmd = Command::new("ls"); /// let mut child = Birdcage::new().spawn(cmd).unwrap(); /// /// match child.try_wait() { /// Ok(Some(status)) => println!("exited with: {status}"), /// Ok(None) => { /// println!("status not ready yet, let's really wait"); /// let res = child.wait(); /// println!("result: {res:?}"); /// }, /// Err(e) => println!("error attempting to wait: {e}"), /// } /// ``` pub fn try_wait(&mut self) -> io::Result> { // Wait for child process to exit. unsafe { let mut status: libc::c_int = 0; let pid = libc::waitpid(self.pid as i32, &mut status, libc::WNOHANG); if pid == -1 { Err(io::Error::last_os_error()) } else if pid == 0 { Ok(None) } else { match self.exit_signal()? { Some(exit_signal) => Ok(Some(exit_signal)), None => Ok(Some(ExitStatus::from_raw(status))), } } } } /// Simultaneously waits for the child to exit and collect all remaining /// output on the stdout/stderr handles, returning an `Output` /// instance. /// /// The stdin handle to the child process, if any, will be closed /// before waiting. This helps avoid deadlock: it ensures that the /// child does not block waiting for input from the parent, while /// the parent waits for the child to exit. /// /// By default, stdin, stdout and stderr are inherited from the parent. /// In order to capture the output into this `Result` it is /// necessary to create new pipes between parent and child. Use /// `stdout(Stdio::piped())` or `stderr(Stdio::piped())`, respectively. /// /// # Examples /// /// ```should_panic /// use birdcage::process::{Command, Stdio}; /// use birdcage::{Birdcage, Sandbox}; /// /// let mut cmd = Command::new("/bin/cat"); /// cmd.arg("file.txt"); /// cmd.stdout(Stdio::piped()); /// let child = Birdcage::new().spawn(cmd).expect("failed to execute child"); /// /// let output = child.wait_with_output().expect("failed to wait on child"); /// /// assert!(output.status.success()); /// ``` pub fn wait_with_output(mut self) -> io::Result { // Drop stdin, to avoid deadlocks. let _ = self.stdin.take(); // Collect stdio buffers. let reader = ChildReader::new(self.stdout.take(), self.stderr.take())?; let (stdout, stderr) = reader.read()?; // Wait for process termination. let status = self.wait()?; Ok(Output { status, stdout, stderr }) } /// Get the child's exit signal. fn exit_signal(&self) -> io::Result> { // Don't block when trying to read. rustix::fs::fcntl_setfl(&self.exit_signal, OFlags::NONBLOCK)?; // Read exit signal from pipe. let mut bytes = [0; mem::size_of::()]; let read = match rustix::io::read(&self.exit_signal, &mut bytes) { Ok(read) => read, Err(err) if err.kind() == io::ErrorKind::WouldBlock => return Ok(None), Err(err) => return Err(err.into()), }; // Convert signal to exit status. if read == mem::size_of::() { let signal = u32::from_le_bytes(bytes); // Exit signal are the lowest 7 bits of wstatus: // https://github.com/torvalds/linux/blob/259f7d5e2baf87fcbb4fabc46526c9c47fed1914/tools/include/nolibc/types.h#L110 assert!(signal <= 0x7f); Ok(Some(ExitStatus::from_raw(signal as i32))) } else { Ok(None) } } } /// Describes what to do with a standard I/O stream for a child process when /// passed to the [`stdin`], [`stdout`], and [`stderr`] methods of [`Command`]. /// /// [`stdin`]: Command::stdin /// [`stdout`]: Command::stdout /// [`stderr`]: Command::stderr #[derive(Default)] pub struct Stdio { pub(crate) ty: StdioType, } impl Stdio { /// A new pipe should be arranged to connect the parent and child processes. /// /// # Examples /// /// With stdout: /// /// ```no_run /// use birdcage::process::{Command, Stdio}; /// /// Command::new("echo").arg("Hello, world!").stdout(Stdio::piped()); /// ``` /// /// With stdin: /// /// ```no_run /// use std::io::Write; /// /// use birdcage::process::{Command, Stdio}; /// use birdcage::{Birdcage, Sandbox}; /// /// let mut cmd = Command::new("rev"); /// cmd.stdin(Stdio::piped()); /// cmd.stdout(Stdio::piped()); /// let mut child = Birdcage::new().spawn(cmd).expect("Failed to spawn child process"); /// /// let mut stdin = child.stdin.take().expect("Failed to open stdin"); /// std::thread::spawn(move || { /// stdin.write_all("Hello, world!".as_bytes()).expect("Failed to write to stdin"); /// }); /// /// let output = child.wait_with_output().expect("Failed to read stdout"); /// assert_eq!(String::from_utf8_lossy(&output.stdout), "!dlrow ,olleH"); /// ``` /// /// Writing more than a pipe buffer's worth of input to stdin without also /// reading stdout and stderr at the same time may cause a deadlock. /// This is an issue when running any program that doesn't guarantee that it /// reads its entire stdin before writing more than a pipe buffer's /// worth of output. The size of a pipe buffer varies on different /// targets. pub fn piped() -> Self { Self { ty: StdioType::Piped } } /// The child inherits from the corresponding parent descriptor. /// /// # Examples /// /// ```no_run /// use birdcage::process::{Command, Stdio}; /// /// let output = Command::new("echo").arg("Hello, world!").stdout(Stdio::inherit()); /// ``` pub fn inherit() -> Self { Self { ty: StdioType::Inherit } } /// This stream will be ignored. This is the equivalent of attaching the /// stream to `/dev/null`. /// /// # Examples /// /// ```no_run /// use birdcage::process::{Command, Stdio}; /// /// let output = Command::new("echo").arg("Hello, world!").stdout(Stdio::null()); /// ``` pub fn null() -> Self { Self { ty: StdioType::Null } } /// Create pipes necessary for the stdio type. /// /// This will return the corresponding read and write FDs. pub(crate) fn make_pipe(&self, stdin: bool) -> io::Result<(Option, Option)> { match self.ty { StdioType::Inherit | StdioType::Default => Ok((None, None)), StdioType::Piped => { let (rx, tx) = pipe()?; Ok((Some(rx), Some(tx))) }, StdioType::Null => { let null_fd = rustix::fs::open("/dev/null", OFlags::RDWR, Mode::empty())?; if stdin { Ok((Some(null_fd), None)) } else { Ok((None, Some(null_fd))) } }, } } } impl From for Option { fn from(stdio: Stdio) -> Option { match stdio.ty { StdioType::Default => None, StdioType::Inherit => Some(std::process::Stdio::inherit()), StdioType::Piped => Some(std::process::Stdio::piped()), StdioType::Null => Some(std::process::Stdio::null()), } } } /// Type of parent/child I/O coupling. #[derive(Default, Copy, Clone)] pub(crate) enum StdioType { #[default] Default, Piped, Inherit, Null, } /// A handle to a child process's standard input (stdin). /// /// This struct is used in the [`stdin`] field on [`Child`]. /// /// When an instance of `ChildStdin` is [dropped], the `ChildStdin`'s underlying /// file handle will be closed. If the child process was blocked on input prior /// to being dropped, it will become unblocked after dropping. /// /// [`stdin`]: Child::stdin /// [dropped]: Drop pub struct ChildStdin { fd: OwnedFd, } impl ChildStdin { fn new(fd: OwnedFd) -> io::Result { Ok(Self { fd }) } } impl Write for ChildStdin { fn write(&mut self, buf: &[u8]) -> io::Result { rustix::io::write(&self.fd, buf).map_err(io::Error::from) } fn flush(&mut self) -> io::Result<()> { Ok(()) } } /// A handle to a child process's standard output (stdout). /// /// This struct is used in the [`stdout`] field on [`Child`]. /// /// When an instance of `ChildStdout` is [dropped], the `ChildStdout`'s /// underlying file handle will be closed. /// /// [`stdout`]: Child::stdout /// [dropped]: Drop pub struct ChildStdout { fd: OwnedFd, } impl ChildStdout { fn new(fd: OwnedFd) -> io::Result { Ok(Self { fd }) } } impl Read for ChildStdout { fn read(&mut self, buf: &mut [u8]) -> io::Result { rustix::io::read(&self.fd, buf).map_err(io::Error::from) } } /// A handle to a child process's stderr. /// /// This struct is used in the [`stderr`] field on [`Child`]. /// /// When an instance of `ChildStderr` is [dropped], the `ChildStderr`'s /// underlying file handle will be closed. /// /// [`stderr`]: Child::stderr /// [dropped]: Drop pub type ChildStderr = ChildStdout; struct ChildReader { poll_fds: Vec, stdout: Option, stderr: Option, stdout_buffer: Vec, stderr_buffer: Vec, } impl ChildReader { fn new(stdout: Option, stderr: Option) -> io::Result { let mut poll_fds = Vec::new(); if let Some(stdout) = &stdout { rustix::fs::fcntl_setfl(&stdout.fd, OFlags::NONBLOCK)?; let fd = stdout.fd.as_raw_fd(); poll_fds.push(libc::pollfd { fd, events: libc::POLLIN, revents: 0 }); } if let Some(stderr) = &stderr { rustix::fs::fcntl_setfl(&stderr.fd, OFlags::NONBLOCK)?; let fd = stderr.fd.as_raw_fd(); poll_fds.push(libc::pollfd { fd, events: libc::POLLIN, revents: 0 }); } Ok(Self { poll_fds, stdout, stderr, stdout_buffer: Default::default(), stderr_buffer: Default::default(), }) } /// Read stdout and stderr into buffers. fn read(mut self) -> io::Result<(Vec, Vec)> { while !self.poll_fds.is_empty() { // Block for next FD readiness. let result = unsafe { libc::poll(self.poll_fds.as_mut_ptr(), 2, -1) }; if result == -1 { return Err(io::Error::last_os_error()); } // Read from all FDs. for i in (0..self.poll_fds.len()).rev() { // Ignore FDs that aren't ready. let poll_fd = &self.poll_fds[i]; if poll_fd.revents == 0 { continue; } // Get stdio/buffer corresponding to the FD. let (stdio, buffer) = self.stdio_from_fd(poll_fd.fd); // Read all available data. match stdio.read_to_end(buffer) { Ok(_) => { self.poll_fds.remove(i); }, Err(err) if err.kind() == io::ErrorKind::WouldBlock => (), Err(err) => return Err(err), } } } Ok((self.stdout_buffer, self.stderr_buffer)) } /// Get the stdio handles corresponding to a FD. fn stdio_from_fd(&mut self, fd: RawFd) -> (&mut ChildStdout, &mut Vec) { match (self.stdout.as_mut(), self.stderr.as_mut()) { (Some(stdout), _) if stdout.fd.as_raw_fd() == fd => (stdout, &mut self.stdout_buffer), (_, Some(stderr)) if stderr.fd.as_raw_fd() == fd => (stderr, &mut self.stderr_buffer), _ => unreachable!(), } } } ================================================ FILE: src/process/macos.rs ================================================ //! macOS process implementation. // We just re-export STD, since we can spawn this command directly. pub use std::process::{ Child, ChildStderr, ChildStdin, ChildStdout, Command, ExitStatus, Output, Stdio, }; ================================================ FILE: src/process/mod.rs ================================================ #[cfg(target_os = "linux")] mod linux; #[cfg(target_os = "macos")] mod macos; #[cfg(target_os = "linux")] pub use crate::process::linux::{ Child, ChildStderr, ChildStdin, ChildStdout, Command, ExitStatus, Output, Stdio, }; #[cfg(target_os = "macos")] pub use crate::process::macos::{ Child, ChildStderr, ChildStdin, ChildStdout, Command, ExitStatus, Output, Stdio, };