yang123vc / libsocks2c

A multithreaded socks5 proxy lib with utcp support

Macro

1. LOG_DEBUG_DETAIL more detail log
2. DISABLE_DEBUG_LOG disable all debug log
3. UDP_DEBUG_DETAIL enable tcp log
4. TCP_DEBUG_DETAIL enable udp log
5. MULTITHREAD_IO enable multithread support
6. BUILD_DLL export dll, by default only static lib is compiled

---

bUild

1. by adding option -DENABLE_UOUT=ON, udp over utcp feature will be enabled and it requires some extra libraries

   on Linux or OSX, libtins, libpcap are required
   on Windows, wpcap, WinDivert, tins are required

   check the following list for support info

2. when building lib for mobile platform, you need to add -DBUILD_MOBILE_LIB=ON

   generate xcode project for generic device:

    mkdir build
    &&
    cmake .. -G Xcode -DCMAKE_TOOLCHAIN_FILE=../ios.toolchain.cmake -DPLATFORM=OS64 -DBUILD_MOBILE_LIB=ON
   

   for more detail, visit https://github.com/leetal/ios-cmake

   UOUT is not support on mobile platform

---

Encryption:

the encryption method AES-256-GCM provided by libsodium

---

UDP over uTCP

proxy udp over unordered tcp connection

what it basically does is wrapping your udp packet with tcp header and send it via tcp connection which doesn't have retransmission and initiative congestion control

support list:

Platform	Server	Client
OSX	✘	✔
Linux	✔	✔
Win64	✘	✔
Win32	✘	✔

---

The following libraries are required

1. spdlog 1.3.1
2. libsodium 1.0.17
3. libboost_coroutine 1.70.0
4. libboost_context
5. libboost_regex
6. libboost_system

if UDP_OVER_UTCP is defined, on Linux || OSX you also need

1. libtins v4.2
2. libpcap 1.9.0
3. libboost_filesystem 1.70.0

on Win64 you need

1. libtins v4.2
2. WpdPack 4.1.2
3. WinDivert-1.4.3-A

Startup Config

1. udp_over_utcp enable UDP over uTCP feature, the udp packet will be proxy via unordered tcp connection.

2. local_uout_ifname On Linux or Mac you have to specified the name of default network interface for sending packet.

3. local_uout_ip if it is set to "" or left blank, it would try to fetch the ip of default network interface on startup, if it retrives the wrong ip, the uout connection would be unable to establish, you might set an ip to override.

4. server_uout_port the Port for uout connection.

5. dnsuout whether to proxy dns packet via utcp, it just simply check if the dst port is 53, we are not doing any packet inspection

Misc

1. resolve_dns if set true, it will resolve dns locally instead of sending domain proxy request, udp proxy doesn't support domain resolve

2. logtofile set true to write log to file at the current directory

Benchmark

Test Platform:
    i3 8100
    DDR4 2400 16G
    Ubuntu 18.04 64bit

Server and Client are running on the same machine, we use iperf + proxychains4 for testing

server: iperf -s -i 1

client: proxychains4 iperf -c 127.0.0.1 -P x -t 10 where x is the connection number

Result:

Direct connect 70.5 Gbits/sec

Proxy via libsocks2c
    1 Conn: 1.290 Gbits/sec
    2 Conn: 2.400 Gbits/sec
    3 Conn: 2.340 Gbits/sec
    4 Conn: 2.390 Gbits/sec

i3 8100 has only 4 cores and no HT support, we can get almost double performance when increase conn number from 1 to 2, but the curve start to drop slightly when we add more conn into testing.

the tcp session buffer limits the bandwidth,increase buff size to 20480 bytes yields 8.6 Gbits/sec(about 1024MB/s) with dual core which is about 3.6 times than the default.The encryption and obfuscation also have significant impact on performance.