# shadowsocks-libev

[![Build Status](https://travis-ci.com/shadowsocks/shadowsocks-libev.svg?branch=master)](https://travis-ci.com/shadowsocks/shadowsocks-libev) [![Snap Status](https://snapcraft.io/shadowsocks-libev/badge.svg)](https://snapcraft.io/shadowsocks-libev)

## Intro

[Shadowsocks-libev](https://shadowsocks.org) is a lightweight secured SOCKS5
proxy for embedded devices and low-end boxes.

It is a port of [Shadowsocks](https://github.com/shadowsocks/shadowsocks)
created by [@clowwindy](https://github.com/clowwindy), and maintained by
[@madeye](https://github.com/madeye) and [@linusyang](https://github.com/linusyang).

Current version: 3.3.6 | [Changelog](debian/changelog)

## Features

Shadowsocks-libev is written in pure C and depends on [libev](http://software.schmorp.de/pkg/libev.html). It's designed
to be a lightweight implementation of shadowsocks protocol, in order to keep the resource usage as low as possible.

For a full list of feature comparison between different versions of shadowsocks,
refer to the [Wiki page](https://github.com/shadowsocks/shadowsocks/wiki/Feature-Comparison-across-Different-Versions).

## Quick Start

Snap is the recommended way to install the latest binaries.

### Install snap core

https://snapcraft.io/core

### Install from snapcraft.io

Stable channel:

```bash
sudo snap install shadowsocks-libev
```

Edge channel:

```bash
sudo snap install shadowsocks-libev --edge
```

## Installation

### Distribution-specific guide

- [Debian & Ubuntu](#debian--ubuntu)
    + [Install from repository](#install-from-repository-not-recommended)
    + [Build deb package from source](#build-deb-package-from-source)
    + [Configure and start the service](#configure-and-start-the-service)
- [Fedora & RHEL](#fedora--rhel)
    + [Build from source with centos](#build-from-source-with-centos)
- [Archlinux & Manjaro](#archlinux--manjaro)
- [NixOS](#nixos)
- [Nix](#nix)
- [Directly build and install on UNIX-like system](#linux)
- [FreeBSD](#freebsd)
    + [Install](#install)
    + [Configuration](#configuration)
    + [Run](#run)
    + [Run as client](#run-as-client)
- [OpenWRT](#openwrt)
- [OS X](#os-x)
- [Windows (MinGW)](#windows-mingw)
- [Docker](#docker)

* * *

### Initialise the build environment

This repository uses submodules, so you should pull them before you start, using:

```bash
git submodule update --init --recursive
```

### Pre-build configure guide

For a complete list of available configure-time options,
try `cmake -LH` from a build directory.

### Debian & Ubuntu

#### Install from repository (not recommended)

Shadowsocks-libev is available in the official repository for following distributions:

* Debian 8 or higher, including oldoldstable (jessie), old stable (stretch), stable (buster), testing (bullseye) and unstable (sid)
* Ubuntu 16.10 or higher

```bash
sudo apt update
sudo apt install shadowsocks-libev
```

#### Build deb package from source

Supported distributions:

* Debian 8, 9 or higher
* Ubuntu 14.04 LTS, 16.04 LTS, 16.10 or higher

You can build shadowsocks-libev and all its dependencies by script:

```bash
mkdir -p ~/build-area/
cp ./scripts/build_deb.sh ~/build-area/
cd ~/build-area
./build_deb.sh
```

For older systems, building `.deb` packages is not supported.
Please try to build and install directly from source. See the [Linux](#linux) section below.

**Note for Debian 8 (Jessie) users to build their own deb packages**:

We strongly encourage you to install shadowsocks-libev from `jessie-backports-sloppy`. If you insist on building from source, you will need to manually install libsodium from `jessie-backports-sloppy`, **NOT** libsodium in main repository.

For more info about backports, you can refer [Debian Backports](https://backports.debian.org).

``` bash
cd shadowsocks-libev
sudo sh -c 'printf "deb http://deb.debian.org/debian jessie-backports main" > /etc/apt/sources.list.d/jessie-backports.list'
sudo sh -c 'printf "deb http://deb.debian.org/debian jessie-backports-sloppy main" >> /etc/apt/sources.list.d/jessie-backports.list'
sudo apt-get install --no-install-recommends devscripts equivs
mk-build-deps --root-cmd sudo --install --tool "apt-get -o Debug::pkgProblemResolver=yes --no-install-recommends -y"
./autogen.sh && dpkg-buildpackage -b -us -uc
cd ..
sudo dpkg -i shadowsocks-libev*.deb
```

**Note for Debian 9 (Stretch) users to build their own deb packages**:

We strongly encourage you to install shadowsocks-libev from `stretch-backports`. If you insist on building from source, you will need to manually install libsodium from `stretch-backports`, **NOT** libsodium in main repository.

For more info about backports, you can refer [Debian Backports](https://backports.debian.org).

``` bash
cd shadowsocks-libev
sudo sh -c 'printf "deb http://deb.debian.org/debian stretch-backports main" > /etc/apt/sources.list.d/stretch-backports.list'
sudo apt-get install --no-install-recommends devscripts equivs
mk-build-deps --root-cmd sudo --install --tool "apt-get -o Debug::pkgProblemResolver=yes --no-install-recommends -y"
./autogen.sh && dpkg-buildpackage -b -us -uc
cd ..
sudo dpkg -i shadowsocks-libev*.deb
```

#### Configure and start the service

```
# Edit the configuration file
sudo vim /etc/shadowsocks-libev/config.json

# Edit the default configuration for debian
sudo vim /etc/default/shadowsocks-libev

# Start the service
sudo /etc/init.d/shadowsocks-libev start    # for sysvinit, or
sudo systemctl start shadowsocks-libev      # for systemd
```

### Fedora & RHEL

Supported distributions:

* Recent Fedora versions (until EOL)
* RHEL 6, 7 and derivatives (including CentOS, Scientific Linux)

#### Build from source with centos

If you are using CentOS 7, you need to install these prerequirements to build from source code:

```bash
yum install epel-release -y
yum install gcc gettext autoconf libtool automake make pcre-devel asciidoc xmlto c-ares-devel libev-devel libsodium-devel mbedtls-devel -y
```

### Archlinux & Manjaro

```bash
sudo pacman -S shadowsocks-libev
```

Please refer to downstream [PKGBUILD](https://github.com/archlinux/svntogit-community/blob/packages/shadowsocks-libev/trunk/PKGBUILD)
script for extra modifications and distribution-specific bugs.

### NixOS

```bash
nix-env -iA nixos.shadowsocks-libev
```

### Nix

```bash
nix-env -iA nixpkgs.shadowsocks-libev
```

### Linux

In general, you need the following build dependencies:

* cmake (>= 3.2)
* a C compiler (gcc or clang)
* pkg-config
* libmbedtls
* libsodium (>= 1.0.4)
* libpcre2
* libev
* libc-ares
* asciidoc (for documentation only)
* xmlto (for documentation only)

Notes: Fedora 26  libsodium version >= 1.0.12, so you can install via dnf install libsodium instead build from source.

If your system is too old to provide libmbedtls and libsodium (later than **v1.0.8**), you will need to either install those libraries manually or upgrade your system.

If your system provides with those libraries, you **should not** install them from source. You should jump to this section and install them from the distribution repository instead.

For some of the distributions, you might install build dependencies like this:

```bash
# Installation of basic build dependencies
## Debian / Ubuntu
sudo apt-get install --no-install-recommends build-essential cmake libpcre2-dev asciidoc xmlto libev-dev libc-ares-dev libmbedtls-dev libsodium-dev pkg-config
## CentOS / Fedora / RHEL
sudo yum install gcc cmake make asciidoc xmlto c-ares-devel libev-devel
## Arch
sudo pacman -S gcc cmake make asciidoc xmlto c-ares libev

# Installation of libsodium
export LIBSODIUM_VER=1.0.16
wget https://download.libsodium.org/libsodium/releases/old/libsodium-$LIBSODIUM_VER.tar.gz
tar xvf libsodium-$LIBSODIUM_VER.tar.gz
pushd libsodium-$LIBSODIUM_VER
./configure --prefix=/usr && make
sudo make install
popd
sudo ldconfig

# Installation of MbedTLS
export MBEDTLS_VER=2.6.0
wget https://github.com/Mbed-TLS/mbedtls/archive/refs/tags/mbedtls-$MBEDTLS_VER.tar.gz
tar xvf mbedtls-$MBEDTLS_VER.tar.gz
pushd mbedtls-$MBEDTLS_VER
make SHARED=1 CFLAGS="-O2 -fPIC"
sudo make DESTDIR=/usr install
popd
sudo ldconfig

# Start building
git submodule update --init --recursive
mkdir -p build && cd build
cmake ..
make
sudo make install
```

To run unit tests:

```bash
cd build
ctest --output-on-failure
```

You may need to manually install missing softwares.

### FreeBSD
#### Install
Shadowsocks-libev is available in FreeBSD Ports Collection. You can install it in either way, `pkg` or `ports`.

**pkg (recommended)**

```bash
pkg install shadowsocks-libev
```

**ports**

```bash
cd /usr/ports/net/shadowsocks-libev
make install
```

#### Configuration
Edit your `config.json` file. By default, it's located in `/usr/local/etc/shadowsocks-libev`.

To enable shadowsocks-libev, add the following rc variable to your `/etc/rc.conf` file:

```
shadowsocks_libev_enable="YES"
```

#### Run

Start the Shadowsocks server:

```bash
service shadowsocks_libev start
```

#### Run as client
By default, shadowsocks-libev is running as a server in FreeBSD. If you would like to start shadowsocks-libev in client mode, you can modify the rc script (`/usr/local/etc/rc.d/shadowsocks_libev`) manually.

```
# modify the following line from "ss-server" to "ss-local"
command="/usr/local/bin/ss-local"
```

Note that is simply a workaround, each time you upgrade the port your changes will be overwritten by the new version.

### OpenWRT

The OpenWRT project is maintained here:
[openwrt-shadowsocks](https://github.com/shadowsocks/openwrt-shadowsocks).

### OS X
For OS X, use [Homebrew](http://brew.sh) to install or build.

Install Homebrew:

```bash
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
```
Install shadowsocks-libev:

```bash
brew install shadowsocks-libev
```

### Windows (MinGW)
To build Windows native binaries, the recommended method is to use Docker:

* On Windows: double-click `make.bat` in `docker\mingw`
* On Unix-like system:

        cd shadowsocks-libev/docker/mingw
        make

A tarball with 32-bit and 64-bit binaries will be generated in the same directory.

You could also manually use MinGW-w64 compilers to build in Unix-like shell (MSYS2/Cygwin), or cross-compile on Unix-like systems (Linux/MacOS). Please refer to build scripts in `docker/mingw`.

Currently you need to use a patched libev library for MinGW:

* https://github.com/shadowsocks/libev/archive/mingw.zip

Notice that TCP Fast Open (TFO) is only available on **Windows 10**, **1607** or later version (precisely, build >= 14393). If you are using **1709** (build 16299) or later version, you also need to run the following command in PowerShell/Command Prompt **as Administrator** and **reboot** to use TFO properly:

        netsh int tcp set global fastopenfallback=disabled

### Docker

As you expect, simply pull the image and run.
```
docker pull shadowsocks/shadowsocks-libev
docker run -e PASSWORD=<password> -p<server-port>:8388 -p<server-port>:8388/udp -d shadowsocks/shadowsocks-libev
```

More information about the image can be found [here](docker/alpine/README.md).

## Usage

For a detailed and complete list of all supported arguments,
you may refer to the man pages of the applications, respectively.

    ss-[local|redir|server|tunnel|manager]

       -s <server_host>           Host name or IP address of your remote server.

       -p <server_port>           Port number of your remote server.

       -l <local_port>            Port number of your local server.

       -k <password>              Password of your remote server.

       -m <encrypt_method>        Encrypt method: rc4-md5,
                                  aes-128-gcm, aes-192-gcm, aes-256-gcm,
                                  aes-128-cfb, aes-192-cfb, aes-256-cfb,
                                  aes-128-ctr, aes-192-ctr, aes-256-ctr,
                                  camellia-128-cfb, camellia-192-cfb,
                                  camellia-256-cfb, bf-cfb,
                                  chacha20-ietf-poly1305,
                                  xchacha20-ietf-poly1305,
                                  salsa20, chacha20 and chacha20-ietf.
                                  The default cipher is chacha20-ietf-poly1305.

       [-a <user>]                Run as another user.

       [-f <pid_file>]            The file path to store pid.

       [-t <timeout>]             Socket timeout in seconds.

       [-c <config_file>]         The path to config file.

       [-n <number>]              Max number of open files.

       [-i <interface>]           Network interface to bind.
                                  (not available in redir mode)

       [-b <local_address>]       Local address to bind.
                                  For servers: Specify the local address to use 
                                  while this server is making outbound 
                                  connections to remote servers on behalf of the
                                  clients.
                                  For clients: Specify the local address to use 
                                  while this client is making outbound 
                                  connections to the server.

       [-u]                       Enable UDP relay.
                                  (TPROXY is required in redir mode)

       [-U]                       Enable UDP relay and disable TCP relay.
                                  (not available in local mode)

       [-T]                       Use tproxy instead of redirect. (for tcp)
                                  (only available in redir mode)

       [-L <addr>:<port>]         Destination server address and port
                                  for local port forwarding.
                                  (only available in tunnel mode)

       [-6]                       Resolve hostname to IPv6 address first.

       [-d <addr>]                Name servers for internal DNS resolver.
                                  (only available in server mode)

       [--reuse-port]             Enable port reuse.

       [--fast-open]              Enable TCP fast open.
                                  with Linux kernel > 3.7.0.
                                  (only available in local and server mode)

       [--acl <acl_file>]         Path to ACL (Access Control List).
                                  (only available in local and server mode)

       [--manager-address <addr>] UNIX domain socket address.
                                  (only available in server and manager mode)

       [--mtu <MTU>]              MTU of your network interface.

       [--mptcp]                  Enable Multipath TCP on MPTCP Kernel.

       [--no-delay]               Enable TCP_NODELAY.

       [--executable <path>]      Path to the executable of ss-server.
                                  (only available in manager mode)

       [-D <path>]                Path to the working directory of ss-manager.
                                  (only available in manager mode)

       [--key <key_in_base64>]    Key of your remote server.

       [--plugin <name>]          Enable SIP003 plugin. (Experimental)

       [--plugin-opts <options>]  Set SIP003 plugin options. (Experimental)

       [-v]                       Verbose mode.

## Transparent proxy

The latest shadowsocks-libev has provided a *redir* mode. You can configure your Linux-based box or router to proxy all TCP traffic transparently, which is handy if you use an OpenWRT-powered router.

    # Create new chain
    iptables -t nat -N SHADOWSOCKS
    iptables -t mangle -N SHADOWSOCKS

    # Ignore your shadowsocks server's addresses
    # It's very IMPORTANT, just be careful.
    iptables -t nat -A SHADOWSOCKS -d 123.123.123.123 -j RETURN

    # Ignore LANs and any other addresses you'd like to bypass the proxy
    # See Wikipedia and RFC5735 for full list of reserved networks.
    # See ashi009/bestroutetb for a highly optimized CHN route list.
    iptables -t nat -A SHADOWSOCKS -d 0.0.0.0/8 -j RETURN
    iptables -t nat -A SHADOWSOCKS -d 10.0.0.0/8 -j RETURN
    iptables -t nat -A SHADOWSOCKS -d 127.0.0.0/8 -j RETURN
    iptables -t nat -A SHADOWSOCKS -d 169.254.0.0/16 -j RETURN
    iptables -t nat -A SHADOWSOCKS -d 172.16.0.0/12 -j RETURN
    iptables -t nat -A SHADOWSOCKS -d 192.168.0.0/16 -j RETURN
    iptables -t nat -A SHADOWSOCKS -d 224.0.0.0/4 -j RETURN
    iptables -t nat -A SHADOWSOCKS -d 240.0.0.0/4 -j RETURN

    # Anything else should be redirected to shadowsocks's local port
    iptables -t nat -A SHADOWSOCKS -p tcp -j REDIRECT --to-ports 12345

    # Add any UDP rules
    ip route add local default dev lo table 100
    ip rule add fwmark 1 lookup 100
    iptables -t mangle -A SHADOWSOCKS -p udp --dport 53 -j TPROXY --on-port 12345 --tproxy-mark 0x01/0x01

    # Apply the rules
    iptables -t nat -A PREROUTING -p tcp -j SHADOWSOCKS
    iptables -t mangle -A PREROUTING -j SHADOWSOCKS

    # Start the shadowsocks-redir
    ss-redir -u -c /etc/config/shadowsocks.json -f /var/run/shadowsocks.pid

## Transparent proxy (pure tproxy)

Executing this script on the linux host can proxy all outgoing traffic of this machine (except the traffic sent to the reserved address). Other hosts under the same LAN can also change their default gateway to the ip of this linux host (at the same time change the dns server to 1.1.1.1 or 8.8.8.8, etc.) to proxy their outgoing traffic.

> Of course, the ipv6 proxy is similar, just change `iptables` to `ip6tables`, `ip` to `ip -6`, `127.0.0.1` to `::1`, and other details.

```shell
#!/bin/bash

start_ssredir() {
    # please modify MyIP, MyPort, etc.
    (ss-redir -s MyIP -p MyPort -m MyMethod -k MyPasswd -b 127.0.0.1 -l 60080 --no-delay -u -T -v </dev/null &>>/var/log/ss-redir.log &)
}

stop_ssredir() {
    kill -9 $(pidof ss-redir) &>/dev/null
}

start_iptables() {
    ##################### SSREDIR #####################
    iptables -t mangle -N SSREDIR

    # connection-mark -> packet-mark
    iptables -t mangle -A SSREDIR -j CONNMARK --restore-mark
    iptables -t mangle -A SSREDIR -m mark --mark 0x2333 -j RETURN

    # please modify MyIP, MyPort, etc.
    # ignore traffic sent to ss-server
    iptables -t mangle -A SSREDIR -p tcp -d MyIP --dport MyPort -j RETURN
    iptables -t mangle -A SSREDIR -p udp -d MyIP --dport MyPort -j RETURN

    # ignore traffic sent to reserved addresses
    iptables -t mangle -A SSREDIR -d 0.0.0.0/8          -j RETURN
    iptables -t mangle -A SSREDIR -d 10.0.0.0/8         -j RETURN
    iptables -t mangle -A SSREDIR -d 100.64.0.0/10      -j RETURN
    iptables -t mangle -A SSREDIR -d 127.0.0.0/8        -j RETURN
    iptables -t mangle -A SSREDIR -d 169.254.0.0/16     -j RETURN
    iptables -t mangle -A SSREDIR -d 172.16.0.0/12      -j RETURN
    iptables -t mangle -A SSREDIR -d 192.0.0.0/24       -j RETURN
    iptables -t mangle -A SSREDIR -d 192.0.2.0/24       -j RETURN
    iptables -t mangle -A SSREDIR -d 192.88.99.0/24     -j RETURN
    iptables -t mangle -A SSREDIR -d 192.168.0.0/16     -j RETURN
    iptables -t mangle -A SSREDIR -d 198.18.0.0/15      -j RETURN
    iptables -t mangle -A SSREDIR -d 198.51.100.0/24    -j RETURN
    iptables -t mangle -A SSREDIR -d 203.0.113.0/24     -j RETURN
    iptables -t mangle -A SSREDIR -d 224.0.0.0/4        -j RETURN
    iptables -t mangle -A SSREDIR -d 240.0.0.0/4        -j RETURN
    iptables -t mangle -A SSREDIR -d 255.255.255.255/32 -j RETURN

    # mark the first packet of the connection
    iptables -t mangle -A SSREDIR -p tcp --syn                      -j MARK --set-mark 0x2333
    iptables -t mangle -A SSREDIR -p udp -m conntrack --ctstate NEW -j MARK --set-mark 0x2333

    # packet-mark -> connection-mark
    iptables -t mangle -A SSREDIR -j CONNMARK --save-mark

    ##################### OUTPUT #####################
    # proxy the outgoing traffic from this machine
    iptables -t mangle -A OUTPUT -p tcp -m addrtype --src-type LOCAL ! --dst-type LOCAL -j SSREDIR
    iptables -t mangle -A OUTPUT -p udp -m addrtype --src-type LOCAL ! --dst-type LOCAL -j SSREDIR

    ##################### PREROUTING #####################
    # proxy traffic passing through this machine (other->other)
    iptables -t mangle -A PREROUTING -p tcp -m addrtype ! --src-type LOCAL ! --dst-type LOCAL -j SSREDIR
    iptables -t mangle -A PREROUTING -p udp -m addrtype ! --src-type LOCAL ! --dst-type LOCAL -j SSREDIR

    # hand over the marked package to TPROXY for processing
    iptables -t mangle -A PREROUTING -p tcp -m mark --mark 0x2333 -j TPROXY --on-ip 127.0.0.1 --on-port 60080
    iptables -t mangle -A PREROUTING -p udp -m mark --mark 0x2333 -j TPROXY --on-ip 127.0.0.1 --on-port 60080
}

stop_iptables() {
    ##################### PREROUTING #####################
    iptables -t mangle -D PREROUTING -p tcp -m mark --mark 0x2333 -j TPROXY --on-ip 127.0.0.1 --on-port 60080 &>/dev/null
    iptables -t mangle -D PREROUTING -p udp -m mark --mark 0x2333 -j TPROXY --on-ip 127.0.0.1 --on-port 60080 &>/dev/null

    iptables -t mangle -D PREROUTING -p tcp -m addrtype ! --src-type LOCAL ! --dst-type LOCAL -j SSREDIR &>/dev/null
    iptables -t mangle -D PREROUTING -p udp -m addrtype ! --src-type LOCAL ! --dst-type LOCAL -j SSREDIR &>/dev/null

    ##################### OUTPUT #####################
    iptables -t mangle -D OUTPUT -p tcp -m addrtype --src-type LOCAL ! --dst-type LOCAL -j SSREDIR &>/dev/null
    iptables -t mangle -D OUTPUT -p udp -m addrtype --src-type LOCAL ! --dst-type LOCAL -j SSREDIR &>/dev/null

    ##################### SSREDIR #####################
    iptables -t mangle -F SSREDIR &>/dev/null
    iptables -t mangle -X SSREDIR &>/dev/null
}

start_iproute2() {
    ip route add local default dev lo table 100
    ip rule  add fwmark 0x2333        table 100
}

stop_iproute2() {
    ip rule  del   table 100 &>/dev/null
    ip route flush table 100 &>/dev/null
}

start_resolvconf() {
    # or nameserver 8.8.8.8, etc.
    echo "nameserver 1.1.1.1" >/etc/resolv.conf
}

stop_resolvconf() {
    echo "nameserver 114.114.114.114" >/etc/resolv.conf
}

start() {
    echo "start ..."
    start_ssredir
    start_iptables
    start_iproute2
    start_resolvconf
    echo "start end"
}

stop() {
    echo "stop ..."
    stop_resolvconf
    stop_iproute2
    stop_iptables
    stop_ssredir
    echo "stop end"
}

restart() {
    stop
    sleep 1
    start
}

main() {
    if [ $# -eq 0 ]; then
        echo "usage: $0 start|stop|restart ..."
        return 1
    fi

    for funcname in "$@"; do
        if [ "$(type -t $funcname)" != 'function' ]; then
            echo "'$funcname' not a shell function"
            return 1
        fi
    done

    for funcname in "$@"; do
        $funcname
    done
    return 0
}
main "$@"
```

## Security Tips

For any public server, to avoid users accessing localhost of your server, please add `--acl acl/server_block_local.acl` to the command line.

Although shadowsocks-libev can handle thousands of concurrent connections nicely, we still recommend
setting up your server's firewall rules to limit connections from each user:

    # Up to 32 connections are enough for normal usage
    iptables -A INPUT -p tcp --syn --dport ${SHADOWSOCKS_PORT} -m connlimit --connlimit-above 32 -j REJECT --reject-with tcp-reset

## License

```
Copyright: 2013-2015, Clow Windy <clowwindy42@gmail.com>
           2013-2018, Max Lv <max.c.lv@gmail.com>
           2014, Linus Yang <linusyang@gmail.com>

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 <http://www.gnu.org/licenses/>.
```
