shadowsocks server, C implementation

SYNOPSIS

ss-server [options]

DESCRIPTION

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

shadowsocks-c consists of five components. ss-server(1) runs on a remote server to provide secured tunnel service. For more information, check out shadowsocks-libev(8).

OPTIONS

Options include all supported platform variants; restrictions are noted below.

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

-s <server_host>: Set a server listening hostname or IP address. May be repeated.

-p <server_port>: Set the server listening port.

-l <local_port>: Accepted for compatibility but ignored by this program; it does not configure a local listener.

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

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

-m <encrypt_method>: Set the cipher. The default is chacha20-ietf-poly1305.

AEAD cipher names from the source (availability depends on the build):

    "aes-128-gcm",
    "aes-192-gcm",
    "aes-256-gcm",
    "2022-blake3-aes-128-gcm",
    "2022-blake3-aes-256-gcm",
    "chacha20-ietf-poly1305",
    "2022-blake3-chacha20-poly1305",
#ifdef FS_HAVE_XCHACHA20IETF
    "xchacha20-ietf-poly1305"
#endif

Legacy stream cipher names recognized by the source (disabled in minimal builds; some require backend support):

    "table",
    "rc4",
    "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",
    "cast5-cfb",
    "des-cfb",
    "idea-cfb",
    "rc2-cfb",
    "seed-cfb",
    "salsa20",
    "chacha20",
    "chacha20-ietf"

The 2022-blake3-* ciphers implement Shadowsocks 2022 (SIP022). They require a base64-encoded pre-shared key supplied with -k: 16 bytes for 2022-blake3-aes-128-gcm and 32 bytes for the other 2022 ciphers. Generate a 32-byte key with openssl rand -base64 32. Passwords are not stretched into keys for these ciphers.

-b <local_address>: Set the local address for outbound connections to destination servers.

-c <config_file>: Use a configuration file.

Refer to shadowsocks-c(8) CONFIG FILE section for more details.

-i <interface>: Send outbound traffic through the specified network interface where supported by the platform.

-d <addr>: Configure name servers for the internal c-ares DNS resolver. By default it uses the system resolver configuration.

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

-n <number>: Specify the maximum number of open files. Requires a platform with setrlimit support.

-h: Print help message.

-u: Enable UDP relay.

-U: Enable UDP relay and disable TCP relay.

-v: Enable verbose mode.

-6: Resolve hostname to IPv6 address first.

-A: Deprecated one-time authentication option. Exits with an error; use AEAD ciphers instead.

--fast-open: Enable TCP Fast Open where supported by the operating system.

--reuse-port: Enable port reuse where supported by the operating system.

--tcp-incoming-sndbuf <size>: Set TCP send buffer size for incoming connections.

--tcp-incoming-rcvbuf <size>: Set TCP receive buffer size for incoming connections.

--tcp-outgoing-sndbuf <size>: Set TCP send buffer size for outgoing connections.

--tcp-outgoing-rcvbuf <size>: Set TCP receive buffer size for outgoing connections.

--no-delay: Enable TCP_NODELAY.

--acl <acl_config>: Enable ACL (Access Control List) and specify config file.

--manager-address <address>: Set the manager control address: a UNIX domain socket path or an IP address and port.

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

--help: Print help message.

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

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

--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.

--mptcp: Enable Multipath TCP.

Only available with MPTCP enabled Linux kernel.

--nftables-sets <sets>: Linux builds with USE_NFTABLES only: add malicious IP addresses to nftables sets. Format: [<table1>:]<set1>[,[<table2>:]<set2>...].

EXAMPLE

It is recommended to use a config file when starting ss-server(1).

The config file is written in JSON and is easy to edit. Check out the SEE ALSO section for the default path of config file.

# Start the ss-server

ss-server -c /etc/shadowsocks-libev/config.json

INCOMPATIBILITY

The config file of shadowsocks-libev(8) is slightly different from original shadowsocks.

In order to listen to both IPv4/IPv6 address, use the following grammar in your config json file:

{
"server":["::0","0.0.0.0"],
...
}

ss-server(1) also does not understand "port_password" field in config file. If you want to start up multiple server instances with a single config file, please try ss-manager tool. See ss-manager(8) for details.