Erlang mtproto proxy

This part of code was extracted from @socksy_bot.

Features

Promoted channels! See mtproto_proxy_app.src tag option.
"secure" randomized-packet-size protocol (34-symbol secrets starting with 'dd') to prevent detection by DPI
Secure-only mode (only allow connections with 'dd'-secrets). See allowed_protocols option.
Multiple ports with unique secret and promo tag for each port
Very high performance - can handle tens of thousands connections! Scales to all CPU cores. 1Gbps, 90k connections on 4-core/8Gb RAM cloud server.
Supports multiplexing (Many connections Client -> Proxy are wrapped to small amount of connections Proxy -> Telegram Server)
Protection from replay attacks used to detect proxies in some countries
Automatic telegram configuration reload (no need for restarts once per day)
Most of the configuration options can be updated without service restart
Small codebase compared to official one
A lots of metrics could be exported (optional)

How to start - docker

To run with default settings

docker run -d --network=host seriyps/mtproto-proxy

To run on single port with custom port, secret and ad-tag

docker run -d --network=host seriyps/mtproto-proxy -p 443 -s d0d6e111bada5511fcce9584deadbeef -t dcbe8f1493fa4cd9ab300891c0b5b326

or via environmet variables

docker run -d --network=host -e MTP_PORT=443 -e MTP_SECRET=d0d6e111bada5511fcce9584deadbeef -e MTP_TAG=dcbe8f1493fa4cd9ab300891c0b5b326 seriyps/mtproto-proxy

Where

-p 443 / MTP_PORT=… proxy port
-s d0d6e111bada5511fcce9584deadbeef / MTP_SECRET=… proxy secret (don't append dd! it should be 32 chars long!)
-t dcbe8f1493fa4cd9ab300891c0b5b326 / MTP_TAG=… ad-tag that you get from @MTProxybot
-d / MTP_DD_ONLY=t only allow "secure" connections (dd-secrets)

To run with custom config-file

Get the code git clone https://github.com/seriyps/mtproto_proxy.git && cd mtproto_proxy/
Copy config templates cp config/{vm.args.example,prod-vm.args}; cp config/{sys.config.example,prod-sys.config}
Edit configs. See Settings.
Build docker build -t mtproto-proxy-erl .
Start docker run -d --network=host mtproto-proxy-erl

Installation via docker can work well for small setups (10-20k connections), but for more heavily-loaded setups it's recommended to install proxy directly into your server's OS (see below).

How to start OS-install - quick

sudo apt install erlang-nox erlang-dev build-essential
git clone https://github.com/seriyps/mtproto_proxy.git
cd mtproto_proxy/
cp config/vm.args.example config/prod-vm.args
cp config/sys.config.example config/prod-sys.config
# configure your port, secret, ad_tag. See [Settings](#settings) below.
nano config/prod-sys.config
make && sudo make install
sudo systemctl enable mtproto-proxy
sudo systemctl start mtproto-proxy

How to start OS-install - detailed

Install deps (ubuntu 18.04)

sudo apt install erlang-nox erlang-dev build-essential

You need Erlang version 20 or higher! If your version is older, please, check Erlang solutions esl-erlang package or use kerl.

Get the code:

git clone https://github.com/seriyps/mtproto_proxy.git
cd mtproto_proxy/

Create config file

see Settings.

Build and install

make && sudo make install

This will:

install proxy into /opt/mtp_proxy
create a system user
install systemd service
create a directory for logs in /var/log/mtproto-proxy
Configure ulimit of max open files and CAP_NET_BIND_SERVICE by systemd

Try to start in foreground mode

This step is optional, but it can be usefull to test if everything works as expected

./start.sh

try to run ./start.sh -h to learn some useful options.

Start in background and enable start on system start-up

sudo systemctl enable mtproto-proxy
sudo systemctl start mtproto-proxy

Done! Proxy is up and ready to serve now!

Stop / uninstall

Stop:

sudo systemctl stop mtproto-proxy

Uninstall:

sudo systemctl stop mtproto-proxy
sudo systemctl disable mtproto-proxy
sudo make uninstall

Logs can be found at

/var/log/mtproto-proxy/application.log

Settings

All possible documanted configuration options could be found in src/mtproto_proxy.app.src. Do not edit this file!

To change configuration, edit config/prod-sys.config:

Comments in this file start from %%. Default port is 1443 and default secret is d0d6e111bada5511fcce9584deadbeef.

Secret key and proxy URL will be printed on start.

The easiest way to update config right now is to edit config/prod-sys.config and then re-install proxy by

sudo make uninstall && make && sudo make install

There are other ways as well. It's even possible to update configuration options without service restart / without downtime, but it's a bit trickier.

Change default port / secret / ad tag

To change default settings, change mtproto_proxy section of prod-sys.config as:

 {mtproto_proxy,
  %% see src/mtproto_proxy.app.src for examples.
  %% DO NOT EDIT src/mtproto_proxy.app.src!!!
  [
   {ports,
    [#{name => mtp_handler1,
       listen_ip => "0.0.0.0",
       port => 1443,
       secret => <<"d0d6e111bada5511fcce9584deadbeef">>,
       tag => <<"dcbe8f1493fa4cd9ab300891c0b5b326">>}
    ]}
   ]},

 {lager,
<...>

(so, remove %%s) and replace port / secret / tag with yours.

Listen on multiple ports / IPs

You can start proxy on many IP addresses or ports with different secrets/ad tags. To do so, just add more configs to ports section, separated by comma, eg:

 {mtproto_proxy,
  %% see src/mtproto_proxy.app.src for examples.
  %% DO NOT EDIT src/mtproto_proxy.app.src!!!
  [
   {ports,
    [#{name => mtp_handler_1,
       listen_ip => "0.0.0.0",
       port => 1443,
       secret => <<"d0d6e111bada5511fcce9584deadbeef">>,
       tag => <<"dcbe8f1493fa4cd9ab300891c0b5b326">>},
     #{name => mtp_handler_2,
       listen_ip => "0.0.0.0",
       port => 2443,
       secret => <<"100000000000000000000000000000001">>,
       tag => <<"cf8e6baff125ed5f661a761e69567711">>}
    ]}
   ]},

 {lager,
<...>

Each section should have unique name!

Only allow connections with 'dd'-secrets

It might be useful in Iran, where proxies are detected by DPI. You should disable all protocols other than mtp_secure by providing allowed_protocols option:

  {mtproto_proxy,
   [
    {allowed_protocols, [mtp_secure]},
    {ports,
     [#{name => mtp_handler_1,
      <..>

Tune resource consumption

If your server have low amount of RAM, try to set

{upstream_socket_buffer_size, 5120},
{downstream_socket_buffer_size, 51200},
{replay_checks_enabled, []},

this may make proxy slower, it can start consume more CPU, will be vulnerable to replay attacks, but will use less RAM.

If your server have lots of RAM, you can make it faster (users will get higher uppload/download speed), it will use less CPU and will be better protected from replay attacks, but will use more RAM:

{upstream_socket_buffer_size, 20480},
{downstream_socket_buffer_size, 512000},
{replay_checks_enabled, [mtp_session_storage]},
{replay_check_session_storage_opts,
  #{max_memory_mb => 2048,
    max_age_minutes => 1440}},

Also, for highload setups it's recommended to increase sysctl parameters:

sudo sysctl net.ipv4.tcp_max_orphans=128000
sudo sysctl 'net.ipv4.tcp_mem=179200 256000 384000'

Values for tcp_mem are in pages. Size of one page can be found by getconf PAGESIZE and is most likely 4kb.

Helpers

Number of connections

/opt/mtp_proxy/bin/mtp_proxy eval 'lists:sum([proplists:get_value(all_connections, L) || {_, L} <- ranch:info()]).'

esfand/mtproto_proxy