![quiche](quiche.svg) [![crates.io](https://img.shields.io/crates/v/quiche.svg)](https://crates.io/crates/quiche) [![docs.rs](https://docs.rs/quiche/badge.svg)](https://docs.rs/quiche) [![license](https://img.shields.io/github/license/cloudflare/quiche.svg)](https://opensource.org/licenses/BSD-2-Clause) ![build](https://img.shields.io/github/actions/workflow/status/cloudflare/quiche/stable.yml?branch=master) [quiche] is an implementation of the QUIC transport protocol and HTTP/3 as specified by the [IETF]. It provides a low level API for processing QUIC packets and handling connection state. The application is responsible for providing I/O (e.g. sockets handling) as well as an event loop with support for timers. For more information on how quiche came about and some insights into its design you can read a [post] on Cloudflare's blog that goes into some more detail. [quiche]: https://docs.quic.tech/quiche/ [ietf]: https://quicwg.org/ [post]: https://blog.cloudflare.com/enjoy-a-slice-of-quic-and-rust/ Who uses quiche? ---------------- ### Cloudflare quiche powers Cloudflare edge network's [HTTP/3 support][cloudflare-http3]. The [cloudflare-quic.com](https://cloudflare-quic.com) website can be used for testing and experimentation. ### Android Android's DNS resolver uses quiche to [implement DNS over HTTP/3][android-http3]. ### curl quiche can be [integrated into curl][curl-http3] to provide support for HTTP/3. ### NGINX (unofficial) quiche can be [integrated into NGINX](nginx/) using an unofficial patch to provide support for HTTP/3. [cloudflare-http3]: https://blog.cloudflare.com/http3-the-past-present-and-future/ [android-http3]: https://security.googleblog.com/2022/07/dns-over-http3-in-android.html [curl-http3]: https://github.com/curl/curl/blob/master/docs/HTTP3.md#quiche-version Getting Started --------------- ### Command-line apps Before diving into the quiche API, here are a few examples on how to use the quiche tools provided as part of the [quiche-apps](apps/) crate. After cloning the project according to the command mentioned in the [building](#building) section, the client can be run as follows: ```bash $ cargo run --bin quiche-client -- https://cloudflare-quic.com/ ``` while the server can be run as follows: ```bash $ cargo run --bin quiche-server -- --cert apps/src/bin/cert.crt --key apps/src/bin/cert.key ``` (note that the certificate provided is self-signed and should not be used in production) Use the `--help` command-line flag to get a more detailed description of each tool's options. ### Configuring connections The first step in establishing a QUIC connection using quiche is creating a [`Config`] object: ```rust let mut config = quiche::Config::new(quiche::PROTOCOL_VERSION)?; config.set_application_protos(&[b"example-proto"]); // Additional configuration specific to application and use case... ``` The [`Config`] object controls important aspects of the QUIC connection such as QUIC version, ALPN IDs, flow control, congestion control, idle timeout and other properties or features. QUIC is a general-purpose transport protocol and there are several configuration properties where there is no reasonable default value. For example, the permitted number of concurrent streams of any particular type is dependent on the application running over QUIC, and other use-case specific concerns. quiche defaults several properties to zero, applications most likely need to set these to something else to satisfy their needs using the following: - [`set_initial_max_streams_bidi()`] - [`set_initial_max_streams_uni()`] - [`set_initial_max_data()`] - [`set_initial_max_stream_data_bidi_local()`] - [`set_initial_max_stream_data_bidi_remote()`] - [`set_initial_max_stream_data_uni()`] [`Config`] also holds TLS configuration. This can be changed by mutators on the an existing object, or by constructing a TLS context manually and creating a configuration using [`with_boring_ssl_ctx()`]. A configuration object can be shared among multiple connections. ### Connection setup On the client-side the [`connect()`] utility function can be used to create a new connection, while [`accept()`] is for servers: ```rust // Client connection. let conn = quiche::connect(Some(&server_name), &scid, local, peer, &mut config)?; // Server connection. let conn = quiche::accept(&scid, None, local, peer, &mut config)?; ``` ### Handling incoming packets Using the connection's [`recv()`] method the application can process incoming packets that belong to that connection from the network: ```rust let to = socket.local_addr().unwrap(); loop { let (read, from) = socket.recv_from(&mut buf).unwrap(); let recv_info = quiche::RecvInfo { from, to }; let read = match conn.recv(&mut buf[..read], recv_info) { Ok(v) => v, Err(e) => { // An error occurred, handle it. break; }, }; } ``` ### Generating outgoing packets Outgoing packet are generated using the connection's [`send()`] method instead: ```rust loop { let (write, send_info) = match conn.send(&mut out) { Ok(v) => v, Err(quiche::Error::Done) => { // Done writing. break; }, Err(e) => { // An error occurred, handle it. break; }, }; socket.send_to(&out[..write], &send_info.to).unwrap(); } ``` When packets are sent, the application is responsible for maintaining a timer to react to time-based connection events. The timer expiration can be obtained using the connection's [`timeout()`] method. ```rust let timeout = conn.timeout(); ``` The application is responsible for providing a timer implementation, which can be specific to the operating system or networking framework used. When a timer expires, the connection's [`on_timeout()`] method should be called, after which additional packets might need to be sent on the network: ```rust // Timeout expired, handle it. conn.on_timeout(); // Send more packets as needed after timeout. loop { let (write, send_info) = match conn.send(&mut out) { Ok(v) => v, Err(quiche::Error::Done) => { // Done writing. break; }, Err(e) => { // An error occurred, handle it. break; }, }; socket.send_to(&out[..write], &send_info.to).unwrap(); } ``` #### Pacing It is recommended that applications [pace] sending of outgoing packets to avoid creating packet bursts that could cause short-term congestion and losses in the network. quiche exposes pacing hints for outgoing packets through the [`at`] field of the [`SendInfo`] structure that is returned by the [`send()`] method. This field represents the time when a specific packet should be sent into the network. Applications can use these hints by artificially delaying the sending of packets through platform-specific mechanisms (such as the [`SO_TXTIME`] socket option on Linux), or custom methods (for example by using user-space timers). [pace]: https://datatracker.ietf.org/doc/html/rfc9002#section-7.7 [`SO_TXTIME`]: https://man7.org/linux/man-pages/man8/tc-etf.8.html ### Sending and receiving stream data After some back and forth, the connection will complete its handshake and will be ready for sending or receiving application data. Data can be sent on a stream by using the [`stream_send()`] method: ```rust if conn.is_established() { // Handshake completed, send some data on stream 0. conn.stream_send(0, b"hello", true)?; } ``` The application can check whether there are any readable streams by using the connection's [`readable()`] method, which returns an iterator over all the streams that have outstanding data to read. The [`stream_recv()`] method can then be used to retrieve the application data from the readable stream: ```rust if conn.is_established() { // Iterate over readable streams. for stream_id in conn.readable() { // Stream is readable, read until there's no more data. while let Ok((read, fin)) = conn.stream_recv(stream_id, &mut buf) { println!("Got {} bytes on stream {}", read, stream_id); } } } ``` ### HTTP/3 The quiche [HTTP/3 module] provides a high level API for sending and receiving HTTP requests and responses on top of the QUIC transport protocol. [`Config`]: https://docs.quic.tech/quiche/struct.Config.html [`set_initial_max_streams_bidi()`]: https://docs.rs/quiche/latest/quiche/struct.Config.html#method.set_initial_max_streams_bidi [`set_initial_max_streams_uni()`]: https://docs.rs/quiche/latest/quiche/struct.Config.html#method.set_initial_max_streams_uni [`set_initial_max_data()`]: https://docs.rs/quiche/latest/quiche/struct.Config.html#method.set_initial_max_data [`set_initial_max_stream_data_bidi_local()`]: https://docs.rs/quiche/latest/quiche/struct.Config.html#method.set_initial_max_stream_data_bidi_local [`set_initial_max_stream_data_bidi_remote()`]: https://docs.rs/quiche/latest/quiche/struct.Config.html#method.set_initial_max_stream_data_bidi_remote [`set_initial_max_stream_data_uni()`]: https://docs.rs/quiche/latest/quiche/struct.Config.html#method.set_initial_max_stream_data_uni [`with_boring_ssl_ctx()`]: https://docs.quic.tech/quiche/struct.Config.html#method.with_boring_ssl_ctx [`connect()`]: https://docs.quic.tech/quiche/fn.connect.html [`accept()`]: https://docs.quic.tech/quiche/fn.accept.html [`recv()`]: https://docs.quic.tech/quiche/struct.Connection.html#method.recv [`send()`]: https://docs.quic.tech/quiche/struct.Connection.html#method.send [`timeout()`]: https://docs.quic.tech/quiche/struct.Connection.html#method.timeout [`on_timeout()`]: https://docs.quic.tech/quiche/struct.Connection.html#method.on_timeout [`stream_send()`]: https://docs.quic.tech/quiche/struct.Connection.html#method.stream_send [`readable()`]: https://docs.quic.tech/quiche/struct.Connection.html#method.readable [`stream_recv()`]: https://docs.quic.tech/quiche/struct.Connection.html#method.stream_recv [HTTP/3 module]: https://docs.quic.tech/quiche/h3/index.html Have a look at the [quiche/examples/] directory for more complete examples on how to use the quiche API, including examples on how to use quiche in C/C++ applications (see below for more information). [examples/]: quiche/examples/ Calling quiche from C/C++ ------------------------- quiche exposes a [thin C API] on top of the Rust API that can be used to more easily integrate quiche into C/C++ applications (as well as in other languages that allow calling C APIs via some form of FFI). The C API follows the same design of the Rust one, modulo the constraints imposed by the C language itself. When running ``cargo build``, a static library called ``libquiche.a`` will be built automatically alongside the Rust one. This is fully stand-alone and can be linked directly into C/C++ applications. Note that in order to enable the FFI API, the ``ffi`` feature must be enabled (it is disabled by default), by passing ``--features ffi`` to ``cargo``. [thin C API]: https://github.com/cloudflare/quiche/blob/master/quiche/include/quiche.h Building -------- quiche requires Rust 1.66 or later to build. The latest stable Rust release can be installed using [rustup](https://rustup.rs/). Once the Rust build environment is setup, the quiche source code can be fetched using git: ```bash $ git clone --recursive https://github.com/cloudflare/quiche ``` and then built using cargo: ```bash $ cargo build --examples ``` cargo can also be used to run the testsuite: ```bash $ cargo test ``` Note that [BoringSSL], which is used to implement QUIC's cryptographic handshake based on TLS, needs to be built and linked to quiche. This is done automatically when building quiche using cargo, but requires the `cmake` command to be available during the build process. On Windows you also need [NASM](https://www.nasm.us/). The [official BoringSSL documentation](https://github.com/google/boringssl/blob/master/BUILDING.md) has more details. In alternative you can use your own custom build of BoringSSL by configuring the BoringSSL directory with the ``QUICHE_BSSL_PATH`` environment variable: ```bash $ QUICHE_BSSL_PATH="/path/to/boringssl" cargo build --examples ``` [BoringSSL]: https://boringssl.googlesource.com/boringssl/ ### Building for Android Building quiche for Android (NDK version 19 or higher, 21 recommended), can be done using [cargo-ndk] (v2.0 or later). First the [Android NDK] needs to be installed, either using Android Studio or directly, and the `ANDROID_NDK_HOME` environment variable needs to be set to the NDK installation path, e.g.: ```bash $ export ANDROID_NDK_HOME=/usr/local/share/android-ndk ``` Then the Rust toolchain for the Android architectures needed can be installed as follows: ```bash $ rustup target add aarch64-linux-android armv7-linux-androideabi i686-linux-android x86_64-linux-android ``` Note that the minimum API level is 21 for all target architectures. [cargo-ndk] (v2.0 or later) also needs to be installed: ```bash $ cargo install cargo-ndk ``` Finally the quiche library can be built using the following procedure. Note that the `-t ` and `-p ` options are mandatory. ```bash $ cargo ndk -t arm64-v8a -p 21 -- build --features ffi ``` See [build_android_ndk19.sh] for more information. [Android NDK]: https://developer.android.com/ndk [cargo-ndk]: https://docs.rs/crate/cargo-ndk [build_android_ndk19.sh]: https://github.com/cloudflare/quiche/blob/master/tools/android/build_android_ndk19.sh ### Building for iOS To build quiche for iOS, you need the following: - Install Xcode command-line tools. You can install them with Xcode or with the following command: ```bash $ xcode-select --install ``` - Install the Rust toolchain for iOS architectures: ```bash $ rustup target add aarch64-apple-ios x86_64-apple-ios ``` - Install `cargo-lipo`: ```bash $ cargo install cargo-lipo ``` To build libquiche, run the following command: ```bash $ cargo lipo --features ffi ``` or ```bash $ cargo lipo --features ffi --release ``` iOS build is tested in Xcode 10.1 and Xcode 11.2. ### Building Docker images In order to build the Docker images, simply run the following command: ```bash $ make docker-build ``` You can find the quiche Docker images on the following Docker Hub repositories: - [cloudflare/quiche](https://hub.docker.com/repository/docker/cloudflare/quiche) - [cloudflare/quiche-qns](https://hub.docker.com/repository/docker/cloudflare/quiche-qns) The `latest` tag will be updated whenever quiche master branch updates. **cloudflare/quiche** Provides a server and client installed in /usr/local/bin. **cloudflare/quiche-qns** Provides the script to test quiche within the [quic-interop-runner](https://github.com/marten-seemann/quic-interop-runner). Copyright --------- Copyright (C) 2018-2019, Cloudflare, Inc. See [COPYING] for the license. [COPYING]: https://github.com/cloudflare/quiche/tree/master/COPYING