Files
Max Lv d6691b9e33 C++20 port 4/14: compile the event loop, UDP relay and programs as C++ (#3068)
* Make the event loop, UDP relay and programs compile as C++

Cast allocator results and void* callback data explicitly, cast string
literals stored in char * variables, replace compound literals in
ss_event.c with zeroing plus member assignment, and give ss-server's
listener array its MAX_REMOTE_NUM bound instead of a VLA.

Where a goto CLEAN_UP jumps over an initialised declaration (C++
rejects that), split the declaration from its initialisation in place.
The variables were already indeterminate at the label in C, and the
cleanup code does not read them. Checked for every MODULE_* variant of
udprelay.c, plus LIB_ONLY for local.c. Still valid C.

* Compile the event loop, UDP relay and programs as C++

Rename utils, ss_event, udprelay, winsock, local, server, tunnel, redir
and manager from .c to .cpp. Inside the moved files only the
\snippet{doc} file references and header comments change; snippet
references in doc/*.md, tests/test_cli_docs.py, the build files and
CONTRIBUTION.md follow the new names.

Also cast the Windows-only string literal returned by
get_default_conf(), found by the zig x86_64-windows-gnu build.

Every module of src/ except the unbuilt android.c and the vendored
blake3 is now compiled as C++20. The new .cpp files join the no-heap
ratchet baseline.

* Add the two casts ss-redir needs as C++

ss-redir only builds on Linux, so the macOS conversion checks never
compiled it: getsockname() wants a struct sockaddr *, and memcpy's
void * result needs a cast.
2026-10-15 09:53:31 +08:00

2.5 KiB

\page ss-redir ss-redir

\brief shadowsocks client as transparent proxy, C implementation

\section ss_redir_synopsis SYNOPSIS

ss-redir [options]

\section ss_redir_description 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-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.

\section ss_redir_options OPTIONS

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

\snippet{doc} redir.cpp cli-options

\section ss_redir_example 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

\section ss_redir_see_also SEE ALSO

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