shadowsocks-libev/doc/ss-redir.asciidoc

ss-redir(1)
===========

NAME
----
ss-redir - shadowsocks client as transparent proxy, libev port

SYNOPSIS
--------
*ss-redir*
 [-uUv6] [-h|--help]
 [-s <server_host>] [-p <server_port>] [-l <local_port>]
 [-k <password>] [-m <encrypt_method>] [-f <pid_file>]
 [-t <timeout>] [-c <config_file>] [-b <local_address>]
 [-a <user_name>] [-n <nofile>] [--mtu <MTU>] [--no-delay]
 [--plugin <plugin_name>] [--plugin-opts <plugin_options>]
 [--password <password>] [--key <key_in_base64>]

DESCRIPTION
-----------
*Shadowsocks-libev* is a lightweight and secure socks5 proxy.
It is a port of the original shadowsocks created by clowwindy.
*Shadowsocks-libev* is written in pure C and takes advantage of libev to
achieve both high performance and low resource consumption.

*Shadowsocks-libev* consists of five components.
`ss-redir`(1) works as a transparent proxy on local machines to proxy TCP
traffic and requires netfilter's NAT module.
For more information, check out `shadowsocks-libev`(8) and the following
'EXAMPLE' section.

OPTIONS
-------
-s <server_host>::
Set the server's hostname or IP.

-p <server_port>::
Set the server's port number.

-l <local_port>::
Set the local port number.

-k <password>::
--password <password>::
Set the password. The server and the client should use the same password.

--key <key_in_base64>::
Set the key directly. The key should be encoded with URL-safe Base64.

-m <encrypt_method>::
Set the cipher.
+
*Shadowsocks-libev* accepts 19 different ciphers:
+
aes-128-gcm, aes-192-gcm, aes-256-gcm,
rc4-md5, aes-128-cfb, aes-192-cfb, aes-256-cfb,
aes-128-ctr, aes-192-ctr, aes-256-ctr, bf-cfb,
camellia-128-cfb, camellia-192-cfb, camellia-256-cfb,
chacha20-ietf-poly1305, xchacha20-ietf-poly1305,
salsa20, chacha20 and chacha20-ietf.
+
The default cipher is 'chacha20-ietf-poly1305'.
+
If built with PolarSSL or custom OpenSSL libraries, some of
these ciphers may not work.

-a <user_name>::
Run as a specific user.

-f <pid_file>::
Start shadowsocks as a daemon with specific pid file.

-t <timeout>::
Set the socket timeout in seconds. The default value is 60.

-c <config_file>::
Use a configuration file.
+
Refer to `shadowsocks-libev`(8) 'CONFIG FILE' section for more details.

-n <number>::
Specify max number of open files.
+
Only available on Linux.

-b <local_address>::
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. You may need root permission.

-U::
Enable UDP relay and disable TCP relay.

-T::
Use tproxy instead of redirect. (for tcp)

-6::
Resovle hostname to IPv6 address first.

--mtu <MTU>::
Specify the MTU of your network interface.

--mptcp::
Enable Multipath TCP.
+
Only available with MPTCP enabled Linux kernel.

--reuse-port::
Enable port reuse.
+
Only available with Linux kernel > 3.9.0.

--no-delay::
Enable TCP_NODELAY.

--plugin <plugin_name>::
Enable SIP003 plugin. (Experimental)

--plugin-opts <plugin_options>::
Set SIP003 plugin options. (Experimental)

-v::
Enable verbose mode.

-h|--help::
Print help message.

EXAMPLE
-------
ss-redir requires netfilter's NAT function. Here is an example:

....
# 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
....

SEE ALSO
--------
`ss-local`(1),
`ss-server`(1),
`ss-tunnel`(1),
`ss-manager`(1),
`shadowsocks-libev`(8),
`iptables`(8),
/etc/shadowsocks-libev/config.json