Merge branch 'master' into v2

Correctly connect to DC203/CDN

.codecov.yml

@@ -0,0 +1,4 @@
+---
+
+fixes:
+  - "github.com/9seconds/mtg/v2/::"

.dockerignore

@@ -1,3 +1,9 @@
-version.go
 vendor/
 tags
+.github/
+.bin/
+*.md
+mtg
+.golangci.toml
+.gitignore
+run.sh

.github/workflows/ci.yaml

@@ -0,0 +1,159 @@
+---
+
+name: CI
+
+permissions:
+  actions: read
+  checks: read
+  contents: read
+  deployments: read
+  issues: read
+  discussions: read
+  pull-requests: read
+  repository-projects: read
+  security-events: read
+  statuses: read
+
+on:
+  push:
+    tags:
+      - v*
+    branches:
+      - master
+      - stable
+      - v1
+  release:
+    types:
+      - published
+      - released
+  pull_request:
+    types:
+      - opened
+      - edited
+      - reopened
+      - synchronize
+      - ready_for_review
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          submodules: recursive
+
+      - uses: jdx/mise-action@v3
+        name: Install mise
+
+      - name: Run tests
+        run: mise tasks run covtest
+
+      - name: Collect coverage
+        uses: codecov/codecov-action@v5
+        with:
+          files: ./coverage.txt
+
+  fuzz:
+    name: Fuzzing
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          submodules: recursive
+
+      - uses: jdx/mise-action@v3
+        name: Install mise
+
+      - name: Run fuzzing
+        run: mise tasks run 'test:fuzz:*'
+
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          submodules: recursive
+
+      - uses: jdx/mise-action@v3
+        name: Install mise
+
+      - name: Run linter
+        run: mise tasks run lint
+
+  docker:
+    name: Docker
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          submodules: recursive
+
+      - name: Get Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            nineseconds/mtg
+            ghcr.io/${{ github.repository }}
+          tags: |
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=raw,value=latest,enable={{is_default_branch}}
+            type=raw,value=master,enable=${{ github.ref == 'refs/heads/master' }}
+            type=raw,value=stable,enable=${{ github.ref == 'refs/heads/stable' }}
+
+      - name: Setup QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Setup BuildX
+        uses: docker/setup-buildx-action@v3
+
+      - name: Setup cache
+        uses: actions/cache@v5
+        with:
+          path: /tmp/buildx-cache
+          key: ${{ runner.os }}-buildx-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-buildx-
+
+      - name: Login to DockerHub
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_PASSWORD }}
+
+      - name: Login to GitHub Container Registry
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          pull: true
+          context: .
+          platforms: linux/amd64,linux/arm64,linux/386,linux/arm/v7,linux/arm/v6
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=local,src=/tmp/buildx-cache
+          cache-to: type=local,dest=/tmp/buildx-cache

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,77 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+# https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#permissions
+# https://github.com/github/codeql-action/issues/572
+permissions:
+  actions: read
+  contents: read
+  pull-requests: read
+  security-events: write
+
+on:
+  push:
+    branches: 
+      - master
+      - stable
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ master ]
+  schedule:
+    - cron: '24 20 * * 5'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

.gitignore

@@ -6,6 +6,5 @@
 *.test
 *.out
 mtg
-vendor/
-version.go
-ccbuilds/
+coverage.txt
+dist/

.golangci.toml

@@ -1,12 +1,21 @@
+# https://golangci-lint.run/docs/configuration/file/
+
+version = '2'
+
 [run]
 concurrency = 4
-deadline = "2m"
 tests = true
-skip-dirs = ["vendor"]
-skip-files = ["version.go"]
 
-[output]
-format = "colored-line-number"
-
-[linters]
-enable-all = true
+# [linters]
+# enable-all = true
+# disable = [
+#     "containedctx",
+#     "exhaustivestruct",
+#     "exhaustruct",
+#     "gas",
+#     "gochecknoglobals",
+#     "goerr113",
+#     "ireturn",
+#     "thelper",
+#     "varnamelen",
+# ]

.goreleaser.yml

@@ -0,0 +1,69 @@
+---
+
+version: 2
+
+project_name: mtg
+
+before:
+  hooks:
+    - go mod tidy
+    - go generate ./...
+
+builds:
+  - binary: '{{ .ProjectName }}'
+    goos:
+      - darwin
+      - freebsd
+      - linux
+      - netbsd
+      - openbsd
+    goarch:
+      - 386
+      - amd64
+      - arm
+      - arm64
+    goarm:
+      - 6
+      - 7
+    env:
+      - CGO_ENABLED=0
+    flags:
+      - -trimpath
+      - -mod=readonly
+    ldflags: -s -w -X main.version={{ .Version }}
+    ignore:
+      - goos: darwin
+        goarch: 386
+      - goos: freebsd
+        goarch: arm64
+      - goos: netbsd
+        goarch: arm64
+      - goos: openbsd
+        goarch: arm64
+
+archives:
+  - name_template: '{{ .ProjectName }}-{{ .Version }}-{{ .Os }}-{{ .Arch }}{{ if .Arm }}v{{ .Arm }}{{ end }}'
+    formats:
+      - tar.gz
+    wrap_in_directory: true
+    format_overrides:
+      - goos: windows
+        formats:
+          - zip
+    files:
+      - LICENSE
+      - README.md
+      - SECURITY.md
+
+gomod:
+  proxy: true
+
+snapshot:
+  version_template: '{{ .Version }}'
+
+checksum:
+  name_template: '{{ .ProjectName }}-{{ .Version }}-checksums.txt'
+
+source:
+  enabled: true
+  name_template: '{{ .ProjectName }}-sources'

.mise.toml

@@ -0,0 +1,101 @@
+[tools]
+go = "latest"
+"go:golang.org/x/tools/gopls" = "latest"
+"go:mvdan.cc/gofumpt" = "latest"
+
+[vars]
+fuzzflags = "-fuzztime=120s"
+
+[tasks.build]
+description = "Build binary"
+sources = ["**/*.go", "go.mod", "go.sum"]
+outputs = ["mtg"]
+run = "go build"
+
+[tasks.update]
+description = "Update dependencies"
+run = [
+    "go get -u",
+    "go mod tidy -go=1.25"
+]
+
+[tasks.lint]
+description = "Run linter"
+tools.golangci-lint = "latest"
+run = "golangci-lint run"
+
+[tasks.test]
+description = "Run tests"
+run = "go test -v ./..."
+
+[tasks.covtest]
+description = "Run tests with code coverage"
+run = "go test -coverprofile=coverage.txt -covermode=atomic -parallel 2 -race -v ./..."
+
+[tasks.test-all]
+description = "Run all tests"
+depends = [
+    "test",
+    "test:fuzz:*"
+]
+
+[tasks."test:fuzz:client-hello"]
+description = "Run fuzzy test for ClientHello"
+run = "go test -v {{ vars.fuzzflags }} -fuzz=FuzzClientHello ./mtglib/internal/faketls"
+
+[tasks."test:fuzz:client-handshake"]
+description = "Run fuzzy test for ClientHandshake"
+run = "go test -v {{ vars.fuzzflags }} -fuzz=FuzzClientHandshake ./mtglib/internal/obfuscated2"
+
+[tasks."test:fuzz:server-generate-handshake-frame"]
+description = "Run fuzzy test for ServerGenerateHandshakeFrame"
+run = "go test -v {{ vars.fuzzflags }} -fuzz=FuzzServerGenerateHandshakeFrame ./mtglib/internal/obfuscated2"
+
+[tasks."test:fuzz:server-receive"]
+description = "Run fuzzy test for ServerReceive"
+run = "go test -v {{ vars.fuzzflags }} -fuzz=FuzzServerReceive ./mtglib/internal/obfuscated2"
+
+[tasks."test:fuzz:server-send"]
+description = "Run fuzzy test for ServerSend"
+run = "go test -v {{ vars.fuzzflags }} -fuzz=FuzzServerSend ./mtglib/internal/obfuscated2"
+
+[tasks.static]
+description = "Build static binary"
+sources = ["**/*.go", "go.mod", "go.sum"]
+outputs = ["mtg"]
+run = """
+#!/bin/bash
+
+version="$(git describe --exact-match HEAD 2>/dev/null || git describe --tags --always)"
+go build \
+    -trimpath \
+    -mod=readonly \
+    -ldflags="-extldflags '-static' -s -w -X 'main.version=$version'" \
+    -a \
+    -tags netgo
+"""
+
+[tasks.release]
+description = "Create release tarballs"
+tools.goreleaser = "latest"
+sources = ["**/*.go", "go.mod", "go.sum", ".goreleaser.yml"]
+run = [
+    "goreleaser --snapshot --clean",
+    "find dist -depth 1 -type d | xargs -r rm -r",
+    "rm ./dist/config.yaml"
+]
+
+[tasks.image]
+description = "Build docker image"
+sources = ["**/*.go", "go.mod", "go.sum", "Dockerfile"]
+run = "docker buildx build --pull -t mtg ."
+
+[tasks.docs]
+description = "Run doc server"
+tools."go:golang.org/x/pkgsite/cmd/pkgsite" = "latest"
+run = "pkgsite -http 0.0.0.0:10000"
+
+[tasks.fmt]
+description = "Reformat source code"
+sources = ["**/*.go"]
+run = "gofumpt -w --extra ."

.travis.yml

@@ -1,21 +0,0 @@
----
-
-language: go
-sudo: false
-dist: trusty
-
-go:
-  - "1.11.x"
-  - master
-
-before_script: make prepare
-
-script:
-  - make all
-  - make lint
-  - make critic
-  - make test
-
-matrix:
-  allow_failures:
-    - go: master

Dockerfile

@@ -1,24 +1,27 @@
 ###############################################################################
 # BUILD STAGE
 
-FROM golang:1.11-alpine
+FROM golang:1.26-alpine AS build
+
+ENV CGO_ENABLED=0
 
 RUN set -x \
   && apk --no-cache --update add \
     bash \
     ca-certificates \
-    curl \
-    git \
-    make \
-    upx \
-  && update-ca-certificates
+    git
 
-COPY . /go/src/github.com/9seconds/mtg/
+COPY . /app
+WORKDIR /app
 
 RUN set -x \
-  && cd /go/src/github.com/9seconds/mtg \
-  && make -j 4 static \
-  && upx --ultra-brute -qq ./mtg
+  && version="$(git describe --exact-match HEAD 2>/dev/null || git describe --tags --always)" \
+  && go build \
+      -trimpath \
+      -mod=readonly \
+      -ldflags="-extldflags '-static' -s -w -X 'main.version=$version'" \
+      -a \
+      -tags netgo
 
 
 ###############################################################################
@@ -26,12 +29,9 @@ RUN set -x \
 
 FROM scratch
 
-ENTRYPOINT ["/usr/local/bin/mtg"]
-ENV MTG_IP=0.0.0.0 \
-    MTG_PORT=3128 \
-    MTG_STATS_IP=0.0.0.0 \
-    MTG_STATS_PORT=3129
-EXPOSE 3128 3129
+ENTRYPOINT ["/mtg"]
+CMD ["run", "/config.toml"]
 
-COPY --from=0 /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
-COPY --from=0 /go/src/github.com/9seconds/mtg/mtg /usr/local/bin/mtg
+COPY --from=build /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
+COPY --from=build /app/mtg /mtg
+COPY --from=build /app/example.config.toml /config.toml

Makefile

@@ -1,87 +0,0 @@
-ROOT_DIR     := $(shell dirname $(realpath $(lastword $(MAKEFILE_LIST))))
-IMAGE_NAME   := mtg
-APP_NAME     := $(IMAGE_NAME)
-
-CC_BINARIES  := $(shell bash -c "echo -n $(APP_NAME)-{linux,freebsd,openbsd}-{386,amd64} $(APP_NAME)-linux-{arm,arm64}")
-APP_DEPS     := version.go
-
-GOLANGCI_LINT_VERSION := v1.10.2
-
-COMMON_BUILD_FLAGS := -ldflags="-s -w"
-
-MOD_ON  := env GO111MODULE=on
-MOD_OFF := env GO111MODULE=auto
-
-# -----------------------------------------------------------------------------
-
-$(APP_NAME): $(APP_DEPS)
-	@$(MOD_ON) go build $(COMMON_BUILD_FLAGS) -o "$(APP_NAME)"
-
-static-$(APP_NAME): $(APP_DEPS)
-	@$(MOD_ON) env CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo $(COMMON_BUILD_FLAGS) -o "$(APP_NAME)"
-
-$(APP_NAME)-%: GOOS=$(shell echo -n "$@" | sed 's?$(APP_NAME)-??' | cut -f1 -d-)
-$(APP_NAME)-%: GOARCH=$(shell echo -n "$@" | sed 's?$(APP_NAME)-??' | cut -f2 -d-)
-$(APP_NAME)-%: $(APP_DEPS) ccbuilds
-	@$(MOD_ON) env "GOOS=$(GOOS)" "GOARCH=$(GOARCH)" \
-		go build \
-		$(COMMON_BUILD_FLAGS) \
-		-o "./ccbuilds/$(APP_NAME)-$(GOOS)-$(GOARCH)"
-
-ccbuilds:
-	@rm -rf ./ccbuilds && mkdir -p ./ccbuilds
-
-version.go:
-	@$(MOD_ON) go generate main.go
-
-vendor: go.mod go.sum
-	@$(MOD_ON) go mod vendor
-
-# -----------------------------------------------------------------------------
-
-.PHONY: all
-all: $(APP_NAME)
-
-.PHONY: static
-static: static-$(APP_NAME)
-
-.PHONY: crosscompile
-crosscompile: $(CC_BINARIES)
-
-.PHONY: crosscompile-dir
-crosscompile-dir:
-	@rm -rf "$(CC_DIR)" && mkdir -p "$(CC_DIR)"
-
-.PHONY: test
-test: vendor $(APP_DEPS)
-	@$(MOD_ON) go test -v ./...
-
-.PHONY: lint
-lint: vendor $(APP_DEPS)
-	@$(MOD_OFF) golangci-lint run
-
-.PHONY: critic
-critic: vendor $(APP_DEPS)
-	@$(MOD_OFF) gocritic check-project "$(ROOT_DIR)"
-
-.PHONY: clean
-clean:
-	@git clean -xfd && \
-		git reset --hard >/dev/null && \
-		git submodule foreach --recursive sh -c 'git clean -xfd && git reset --hard' >/dev/null
-
-.PHONY: docker
-docker:
-	@docker build --pull -t "$(IMAGE_NAME)" "$(ROOT_DIR)"
-
-.PHONY: prepare
-prepare: install-lint install-critic
-
-.PHONY: install-lint
-install-lint:
-	@curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh \
-		| $(MOD_OFF) bash -s -- -b $(GOPATH)/bin $(GOLANGCI_LINT_VERSION)
-
-.PHONY: install-critic
-install-critic:
-	@$(MOD_OFF) go get -u github.com/go-critic/go-critic/...

README.md

@@ -1,11 +1,16 @@
 # mtg
 
-Bullshit-free MTPROTO proxy for Telegram
+Highly-opinionated (ex-bullshit-free) MTPROTO proxy for
+[Telegram](https://telegram.org/).
 
-[![Build Status](https://travis-ci.org/9seconds/mtg.svg?branch=master)](https://travis-ci.org/9seconds/mtg)
-[![Docker Build Status](https://img.shields.io/docker/build/nineseconds/mtg.svg)](https://hub.docker.com/r/nineseconds/mtg/)
+[![CI](https://github.com/9seconds/mtg/actions/workflows/ci.yaml/badge.svg?branch=master)](https://github.com/9seconds/mtg/actions/workflows/ci.yaml)
+[![codecov](https://codecov.io/gh/9seconds/mtg/branch/master/graph/badge.svg?token=JfdDyGVpT4)](https://codecov.io/gh/9seconds/mtg)
+[![Go Reference](https://pkg.go.dev/badge/github.com/9seconds/mtg.svg)](https://pkg.go.dev/github.com/9seconds/mtg/v2)
 
-# Rationale
+**If you use v1.0 or upgrade broke you proxy, please read the chapter
+[Version 2](#version-2)**
+
+## Rationale
 
 There are several available proxies for Telegram MTPROTO available. Here
 are the most notable:
@@ -14,223 +19,388 @@ are the most notable:
 * [Python](https://github.com/alexbers/mtprotoproxy)
 * [Erlang](https://github.com/seriyps/mtproto_proxy)
 
-Almost all of them follow the way how official proxy was build. This
-includes support of multiple secrets, support of promoted channels etc.
+You can use any of these. They work great and all implementations have
+feature parity now. This includes support of adtag, replay attack
+protection, domain fronting, faketls, and so on. mtg has a similar
+goal: to give a possibility to connect to Telegram in a restricted,
+censored environment. But it does it slightly differently in details
+that probably matter.
 
-mtg is an implementation in golang which is intended to be:
+* **Resource-efficient**
+
+  It has to be resource-efficient. It does not mean that you will see
+  the smallest memory usage. It means that it will try to use allocated
+  resources in zero-waste mode, reusing as much memory as possible and
+  so on.
 
-* **Lightweight**
-  It has to consume as less resources as possible but not by losing
-  maintainability.
 * **Easily deployable**
+
   I strongly believe that Telegram proxies should follow the way of
-  ShadowSocks: promoted channels is a strange way of doing business
-  I suppose. I think the only viable way is to have a proxy with
-  minimum configuration which should work everywhere.
-* **Single secret**
-  I think that multiple secrets solves no problems and just complexify
-  software. I also believe that in case of throwout proxies, this feature
-  is useless luxury.
-* **Minimum docker image size**
-  Official image is less than 2.5 megabytes. Literally.
+  [ShadowSocks](https://shadowsocks.org): promoted channels is a strange
+  way of doing business I suppose. I think the only viable way is to
+  have a proxy that can be restored anywhere easily.
+
+* **A single secret**
+
+  I think that multiple secrets solve no problems and just complex
+  software. I also believe that in the case of throwout proxies, this
+  the feature is a useless luxury.
+
+* **No adtag support**
+
+  Please read [Version 2](#version-2) chapter.
+
 * **No management WebUI**
-  This is an implementation of simple lightweight proxy. I won't do that.
 
-This proxy supports 2 modes of work: direct connection to Telegram and
-promoted channel mode. If you do not need promoted channels, I would
-recommend you to go with direct mode: this is way more robust.
+  This is an implementation of a simple lightweight proxy. I won't do that.
 
-To run proxy in direct mode, all you need to do is just provide a
-secret. If you do not provide ADTag as a second parameter, promoted
-channels mode won't be activated.
+* **Proxy chaining**
 
-To get promoted channel, please contact
-[@MTProxybot](https://t.me/MTProxybot) and provide generated adtag as a
-second parameter.
+  mtg has the support of [SOCKS5](https://en.wikipedia.org/wiki/SOCKS)
+  proxies. So, in theory, you can run this proxy as a frontend
+  and route traffic via [v2ray](https://www.v2ray.com/),
+  [Gost](https://docs.ginuerzh.xyz/gost/),
+  [Trojan](https://trojan-gfw.github.io/trojan/), or any other project
+  you like.
 
+* **Native blocklist support**
 
-# Source code organization
+  Previously, this was delegated to the [FireHOL](https://firehol.org/)
+  project or similar ones which track attacks and publish a list of
+  potentially dangerous IPs. mtg has native support of such blocklists.
 
-There are 2 main branches:
+* **Can be used as a library**
 
-1. `master` branch contains potentially unstable features
-2. `stable` branch contains stable version. Usually you want to use this branch.
+  mtg v2 was redesigned in a way so it can be embedded into your
+  software (written in Golang) with a minimum effort + you can replace
+  some parts with those you want.
 
-# How to build
+### Version 2
+
+If you use version 1.x before, you are probably noticed some major
+backward non-compatible details:
+
+1. Configuration file
+2. Removed support of adtag
+
+For the configuration file, please check out the full example in this
+repository. It has a lot of comments and most of the options are
+optional. We do have only `secret` and `bind-to` sections mandatory.
+Other sections in the example configuration file are filled with default
+values.
+
+Adtag support was removed completely. This was done to debloat mtg and
+keep it simple and obvious. Hopefully, this goal is achieved and the
+source code is clean and straightforward enough.
+
+I always was quite skeptical about adtag. In my POV, a proxy as a fat
+big connectivity point for hundreds of clients is an illusion. If you
+work in a censored environment, the first thing that authority does is
+IP blocking. For us, it means, those big proxies that can benefit from
+having a pinned channel are going to be blocked in a minute.
+
+Proxy has to be intimate. It has to be shared within a small group as
+a family or maybe your college friends. It has to have a small number
+of connections and never publicly announced its presence. It has to fly
+under the radar. If the proxy is detected, you need to be able to give
+a rebirth on a new IP address as soon as possible. I do no think that
+having some special channel for such a use case makes any sense.
+
+But other details like replay attack protection, domain fronting,
+accurate FakeTLS implementation, IP blacklisting, and proxy
+chaining matter here. If you work in censored perimeter like
+[GFW](https://en.wikipedia.org/wiki/Great_Firewall)-protected
+country, you probably want to have an MTPROTO proxy as
+a frontend that transports traffic via cloaked tunnels
+made by [Trojan](https://trojan-gfw.github.io/trojan/),
+[Shadowsocks](https://shadowsocks.org), [v2ray](https://www.v2ray.com/),
+or [Gost](https://docs.ginuerzh.xyz/gost/). That's why you have to have
+the support of chaining as a first-class citizen.
+
+Yes, this is possible and doable with optional adtag support. But the
+truth is that the MTPROTO proxy for Telegram is just a thing that either
+work as a normal client (direct mode) or doing some RPC calls in [TL
+language](https://core.telegram.org/mtproto/TL) (adtag support). I
+understand the intention of the developers and I understand that they
+were under high pressure fighting with [RKN](https://rkn.gov.ru/) and
+doing TON after that. Nothing is ideal. But for the proxy, it means that
+source code is full of complex non-trivial code which is required only
+to support a feature that we barely need.
+
+So, to have a reasonable MTPROTO proxy, adtag support was removed. This
+is a rare chance in my career where software v2 debloats a previous
+version. It feels so good :)
+
+### Version 1 and 2
+
+I do continue to support both versions 1 and 2. But in a different mode.
+
+Version 1 is now officially in maintenance mode. It means that I won't
+make any new features or improvements there. You can consider a feature
+freeze there. No bugs are going to be fixed there except for critical
+ones. PRs are welcome though. The goal is to keep it working. It will
+get some periodical updates like updates to the new Golang version of
+dependencies version bump, but that's mostly it.
+
+**If you want to have mtg with _adtag support_, please use version 1**.
+
+Version 2 is going to have all my love, active support, bug fixing, etc.
+It is under active development and maintenance.
+
+This project has several main branches
+
+1. [`master`](https://github.com/9seconds/mtg/tree/master) branch
+   contains a bleeding edge. It may potentially have some features
+   which will break your source code.
+2. [`stable`](https://github.com/9seconds/mtg/tree/stable) branch contains
+   dumps of a master branch when we consider it 'stable'. This is a
+   branch you probably want to pick.
+3. [`v2`](https://github.com/9seconds/mtg/tree/v2) has a development
+   of the v2.x version. In theory, it is the same as `master` but this
+   will change when we have v3.x.
+4. [`v1`](https://github.com/9seconds/mtg/tree/v1) has a version 1.x.
+
+## Getting started
+
+### Download a tool
+
+#### Download binaries
+
+Binaries can be downloaded from the release page. Also, you can download
+docker image.
+
+For the current version, please download like
 
 ```console
-make
+docker pull nineseconds/mtg:2
 ```
 
-If you want to build for another platform:
+For version 1:
 
 ```console
-make crosscompile
+docker pull nineseconds/mtg:1
 ```
 
-If you want to build Docker image (called `mtg`):
+You may also check both [Docker
+Hub](https://hub.docker.com/r/nineseconds/mtg/tags) and [Github
+Registry](https://github.com/users/9seconds/packages/container/package/mtg).
+Please do not choose `latest` or `stable` if you want to avoid
+surprises. Always choose some version tag.
+
+Also, if you have `go` installed, you can always download this tool with `go get`:
+
+```console
+go install github.com/9seconds/mtg/v2@latest
+```
+
+#### Build from sources
+
+```console
+git clone https://github.com/9seconds/mtg.git
+cd mtg
+make static
+```
+
+or for the docker image:
 
 ```console
 make docker
 ```
 
-# Docker image
+### Generate secret
 
-Docker follows the same policy as the source code organization:
-
-- `latest` mirrors the master branch
-- `stable` mirrors the stable branch
-- tags are for tagged releases
+If you already have a secret in Base64 format or that, which starts with `ee`,
+you can skip this chapter. Otherwise:
 
 ```console
-docker pull nineseconds/mtg:latest
-```
-
-```console
-docker pull nineseconds/mtg:stable
-```
-
-```console
-docker pull nineseconds/mtg:0.10
-```
-
-# Configuration
-
-Basically, to run this tool you need to configure as less as possible.
-
-First, you need to generate a secret:
-
-```console
-openssl rand -hex 16
+$ mtg generate-secret google.com
+7ibaERuTSGPH1RdztfYnN4tnb29nbGUuY29t
 ```
 
 or
 
 ```console
-head -c 512 /dev/urandom | md5sum | cut -f 1 -d ' '
+$ mtg generate-secret --hex google.com
+ee473ce5d4958eb5f968c87680a23854a0676f6f676c652e636f6d
 ```
 
-## Secure mode
-
-If you want to support new secure mode, please prepend `dd` to the
-secret. For example, secret `cf18fa8ea0267057e2c61a5f7322a8e7` should
-be `ddcf18fa8ea0267057e2c61a5f7322a8e7`. But pay attention that some
-old clients won't support this mode. If this is not your case, I would
-suggest to go with this mode.
-
-Oneliners to generate such secrets:
+equivalent commands with docker:
 
 ```console
-echo dd$(openssl rand -hex 16)
+$ docker run --rm nineseconds/mtg:2 generate-secret google.com
+7ibaERuTSGPH1RdztfYnN4tnb29nbGUuY29t
+
+$ docker run --rm nineseconds/mtg:2 generate-secret --hex google.com
+ee473ce5d4958eb5f968c87680a23854a0676f6f676c652e636f6d
 ```
 
-or
+This secret is a keystone for a proxy and your password for a client.
+You need to keep it secured.
+
+We recommend choosing a hostname wisely. Here we have a _google.com_
+but in reality, all providers can easily detect that this is not a
+Google. Google has a list of networks it officially uses and your IP
+address won't probably belong to it. It is a great idea to hide behind
+some domain that has some relation to this IP address.
+
+For example, you've bought a VPS from [Digital
+Ocean](https://www.digitalocean.com/). Then it might be a good idea to
+generate a secret for _digitalocean.com_ then.
+
+
+### Simple run mode
+
+mtg supports 2 modes: simple and normal. Simple mode allows starting
+proxy with a small subset of configuration options you usually want to
+modify. This is quite good for oneliners that you can copy-paste and do
+not bother about external files whatsoever.
+
+Let's take a look:
 
 ```console
-echo dd$(head -c 512 /dev/urandom | md5sum | cut -f 1 -d ' ')
+Usage: mtg simple-run <bind-to> <secret>
+
+Run proxy without config file.
+
+Arguments:
+  <bind-to>    A host:port to bind proxy to.
+  <secret>     Proxy secret.
+
+Flags:
+  -h, --help                           Show context-sensitive help.
+  -v, --version                        Print version.
+
+  -d, --debug                          Run in debug mode.
+  -c, --concurrency=8192               Max number of concurrent connection to proxy.
+  -b, --tcp-buffer="4KB"               Size of TCP buffer to use.
+  -i, --prefer-ip="prefer-ipv6"        IP preference. By default we prefer IPv6 with fallback to IPv4.
+  -p, --domain-fronting-port=443       A port to access for domain fronting.
+  -n, --doh-ip=1.1.1.1                 IP address of DNS-over-HTTP to use.
+  -t, --timeout=10s                    Network timeout to use
+  -a, --antireplay-cache-size="1MB"    A size of anti-replay cache to use.
 ```
 
-If you want to enforce the usage of secure mode, please pass `-s` or
-`--secure-only` flags. In that case, clients which do not use dd-secrets
-are going to be disconnected from the proxy.
-
-
-## Environment variables
-
-It is possible to configure this tool using environment variables. You
-can configure any flag but not secret or adtag. Here is the list of
-supported environment variables:
-
-| Environment variable     | Corresponding flags    | Default value                     | Description                                                                                                                                                                                                                                                                |
-|--------------------------|------------------------|-----------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| `MTG_DEBUG`              | `-d`, `--debug`        | `false`                           | Run in debug mode. Usually, you need to run in this mode  only if you develop this tool or its maintainer is asking you to provide  logs with such verbosity.                                                                                                              |
-| `MTG_VERBOSE`            | `-v`, `--verbose`      | `false`                           | Run in verbose mode. This is way less chatty than debug mode.                                                                                                                                                                                                              |
-| `MTG_IP`                 | `-b`, `--bind-ip`      | `127.0.0.1`                       | Which IP should we bind to. As usual, `0.0.0.0` means that we want to listen on all interfaces. Also, 4 zeroes will bind to both IPv4 and IPv6.                                                                                                                            |
-| `MTG_PORT`               | `-p`, `--bind-port`    | `3128`                            | Which port should we bind to (listen on).                                                                                                                                                                                                                                  |
-| `MTG_IPV4`               | `-4`, `--public-ipv4`  | [Autodetect](https://ifconfig.co) | IPv4 address of this proxy. This is required if you NAT your proxy or run it in a docker container. In that case, you absolutely need to specify public IPv4 address of the proxy, otherwise either URLs will be broken or proxy could not access Telegram middle proxies. |
-| `MTG_IPV4_PORT`          | `--public-ipv4-port`   | Value of `--bind-port`            | Which port should be public of IPv4 interface. This affects only generated links and should be changed only if you NAT your proxy or run it in a docker container.                                                                                                         |
-| `MTG_IPV6`               | `-6`, `--public-ipv6`  | [Autodetect](https://ifconfig.co) | IPv6 address of this proxy. This is required if you NAT your proxy or run it in a docker container. In that case, you absolutely need to specify public IPv6 address of the proxy, otherwise either URLs will be broken or proxy could not access Telegram middle proxies. |
-| `MTG_IPV6_PORT`          | `--public-ipv6-port`   | Value of `--bind-port`            | Which port should be public of IPv6 interface. This affects only generated links and should be changed only if you NAT your proxy or run it in a docker container.                                                                                                         |
-| `MTG_STATS_IP`           | `-t`, `--stats-ip`     | `127.0.0.1`                       | Which IP should we bind the internal statistics HTTP server.                                                                                                                                                                                                               |
-| `MTG_STATS_PORT`         | `-q`, `--stats-port`   | `3129`                            | Which port should we bind the internal statistics HTTP server.                                                                                                                                                                                                             |
-| `MTG_STATSD_IP`          | `--statsd-ip`          |                                   | IP/host addresses of statsd service. No defaults, by defaults we do not send anything there.                                                                                                                                                                               |
-| `MTG_STATSD_PORT`        | `--statsd-port`        | `8125`                            | Which port should we use to work with statsd.                                                                                                                                                                                                                              |
-| `MTG_STATSD_NETWORK`     | `--statsd-network`     | `udp`                             | Which protocol should we use to work with statsd. Possible options are `udp` and `tcp`.                                                                                                                                                                                    |
-| `MTG_STATSD_PREFIX`      | `--statsd-prefix`      | `mtg`                             | Which bucket prefix we should use. For example, if you set `mtg`, then metric `traffic.ingress` would be send as `mtg.traffic.ingress`.                                                                                                                                    |
-| `MTG_STATSD_TAGS_FORMAT` | `--statsd-tags-format` |                                   | Which tags format we should use. By default, we are using default vanilla statsd tags format but if you want to send directly to InfluxDB or Datadog, please specify it there. Possible options are `influxdb` and `datadog`.                                              |
-| `MTG_STATSD_TAGS`        | `--statsd-tags`        |                                   | Which tags should we send to statsd with our metrics. Please specify them as `key=value` pairs.                                                                                                                                                                            |
-| `MTG_BUFFER_WRITE`       | `-w`, `--write-buffer` | `65536`                           | The size of TCP write buffer in bytes. Write buffer is the buffer for messages which are going from client to Telegram.                                                                                                                                                    |
-| `MTG_BUFFER_READ`        | `-r`, `--read-buffer`  | `131072`                          | The size of TCP read buffer in bytes. Read buffer is the buffer for messages from Telegram to client.                                                                                                                                                                      |
-| `MTG_SECURE_ONLY`        | `-s`, `--secure-only`  | `false`                           | Support only clients with secure mode (i.e only clients with dd-secrets).                                                                                                                                                                                                  |
-
-Usually you want to modify only read/write buffer sizes. If you feel
-that proxy is slow, try to increase both sizes giving more priority to
-read buffer.
-
-Unfortunately, MTPROTO proxy protocol does not allow us to use splice
-or any other neat tricks how to eliminate the need of copying data into
-userspace.
-
-# How to run the tool
-
-Now run the tool:
+So, if you want to startup a proxy with CLI only, you can do something like
 
 ```console
-mtg <secret>
+$ mtg simple-run -n 1.1.1.1 -t 30s -a 512kib 127.0.0.1:3128 7hBO-dCS4EBzenlKbdLFxyNnb29nbGUuY29t
 ```
 
-How to run the tool with ADTag:
+The rest of the configuration will be taken from default values. But
+a simple run is fine if you do not have any special requirements or
+granular tuning. If you want it, please checkout the configuration
+files.
+
+### Prepare a configuration file
+
+Please checkout an example configuration file. All options except of
+`secret` and `bind-to` are optional. You can safely have this minimal
+configuration file:
+
+```toml
+secret = "ee473ce5d4958eb5f968c87680a23854a0676f6f676c652e636f6d"
+bind-to = "0.0.0.0:443"
+```
+
+This is enough to run the whole application. All other
+options already have sensible defaults for the app at almost any scale.
+
+Oh, the configuration is done in [TOML format](https://toml.io/en/).
+
+### Run a proxy
+
+Put a binary and a config into your webserver. Just for example,
+a binary goes to `/usr/local/bin/mtg` and configuration to `/etc/mtg.toml`.
+
+Now you can create a systemd unit:
 
 ```console
-mtg <secret> <adtag>
+$ cat /etc/systemd/system/mtg.service
+[Unit]
+Description=mtg - MTProto proxy server
+Documentation=https://github.com/9seconds/mtg
+After=network.target
+
+[Service]
+ExecStart=/usr/local/bin/mtg run /etc/mtg.toml
+Restart=always
+RestartSec=3
+DynamicUser=true
+AmbientCapabilities=CAP_NET_BIND_SERVICE
+
+[Install]
+WantedBy=multi-user.target
+$ sudo systemctl daemon-reload
+$ sudo systemctl enable mtg
+$ sudo systemctl start mtg
 ```
 
-This tool will listen on port 3128 by default with the given secret.
-
-# One-line runner
+or you can run a docker image
 
 ```console
-docker run --name mtg --restart=unless-stopped -p 3128:3128 -p 3129:3129 -d nineseconds/mtg:stable $(openssl rand -hex 16)
+docker run -d -v $PWD/config.toml:/config.toml -p 443:3128 --name mtg-proxy --restart=unless-stopped nineseconds/mtg:2
 ```
 
-or in secret mode:
+where _443_ is a host port (a port you want to connect to from a
+client), and _3128_ is the one you have in your config in the `bind-to`
+section.
+
+### Access a proxy
+
+Now you can generate some useful links:
 
 ```console
-docker run --name mtg --restart=unless-stopped -p 3128:3128 -p 3129:3129 -d nineseconds/mtg:stable dd$(openssl rand -hex 16)
+$ mtg access /etc/mtg.toml
+{
+  "ipv4": {
+    "ip": "x.y.z.a",
+    "port": 3128,
+    "tg_url": "tg://proxy?...",
+    "tg_qrcode": "https://api.qrserver.com/v1/create-qr-code?data...",
+    "tme_url": "https://t.me/proxy?...",
+    "tme_qrcode": "https://api.qrserver.com/v1/create-qr-code?data..."
+  },
+  "secret": {
+    "hex": "...",
+    "base64": "..."
+  }
+}
 ```
 
-You will have this tool up and running on port 3128. Now curl
-`localhost:3129` to get `tg://` links or do `docker logs mtg`. Also,
-port 3129 will show you some statistics if you are interested in.
+or if you are using docker:
 
-Also, you can use [run-mtg.sh](https://github.com/9seconds/mtg/blob/master/run-mtg.sh) script
+```console
+$ docker exec mtg-proxy /mtg access /config.toml
+```
 
+## Metrics
 
-# statsd integration
+Out of the box, mtg works with
+[statsd](https://github.com/statsd/statsd) and
+[Prometheus](https://prometheus.io/). Please check configuration file
+example to get how to set this integration up.
 
-mtg provides an integration with statsd, you can enable it with command
-line interface. To enable it, you have to provide IP address of statsd
-service.
+Here goes a list of metrics with their types but without a prefix.
 
-Out of the box, mtg supports 2 additional dialects: [InfluxDB](https://www.influxdata.com/blog/getting-started-with-sending-statsd-metrics-to-telegraf-influxdb/)
-and [Datadog](https://docs.datadoghq.com/developers/dogstatsd/).
+| Name                        | Type    | Tags                             | Description                                                                                |
+|-----------------------------|---------|----------------------------------|--------------------------------------------------------------------------------------------|
+| client_connections          | gauge   | `ip_family`                      | Count of processing client connections.                                                    |
+| telegram_connections        | gauge   | `telegram_ip`, `dc`              | Count of connections to Telegram servers.                                                  |
+| domain_fronting_connections | gauge   | `ip_family`                      | Count of connections to fronting domain.                                                   |
+| iplist_size                 | gauge   | `ip_list`                        | A size of either allowlist or blocklist in use.                                            |
+| telegram_traffic            | counter | `telegram_ip`, `dc`, `direction` | Count of bytes, transmitted to/from Telegram.                                              |
+| domain_fronting_traffic     | counter | `direction`                      | Count of bytes, transmitted to/from fronting domain.                                       |
+| domain_fronting             | counter | –                                | Count of domain fronting events.                                                           |
+| concurrency_limited         | counter | –                                | Count of events, when client connection was rejected due to concurrency limit.             |
+| ip_blocklisted              | counter | `ip_list`                        | Count of events when client connection was rejected because IP was found in the blocklist. |
+| replay_attacks              | counter | –                                | Count of detected replay attacks.                                                          |
 
-All metrics are gauges. Here is the list of metrics and their meaning:
+Tag meaning:
 
-| Metric name                     | Unit    | Description                                               |
-|---------------------------------|---------|-----------------------------------------------------------|
-| `connections.abridged.ipv4`     | number  | The number of active abridged IPv4 connections            |
-| `connections.abridged.ipv6`     | number  | The number of active abridged IPv6 connections            |
-| `connections.intermediate.ipv4` | number  | The number of active intermediate IPv4 connections        |
-| `connections.intermediate.ipv6` | number  | The number of active intermediate IPv6 connections        |
-| `connections.secure.ipv4`       | number  | The number of active secure intermediate IPv4 connections |
-| `connections.secure.ipv6`       | number  | The number of active secure intermediate IPv6 connections |
-| `crashes`                       | number  | An amount of crashes in client handlers                   |
-| `traffic.ingress`               | bytes   | Ingress traffic from the start of application (incoming)  |
-| `traffic.egress`                | bytes   | Egress traffic from the start of application (outgoing)   |
-| `speed.ingress`                 | bytes/s | Ingress bandwidth of the latest second (incoming traffic) |
-| `speed.egress`                  | bytes/s | Egress bandwidth of the latest second (outgoing traffic)  |
-
-All metrics are prefixed with given prefix. Default prefix is `mtg`.
-With such prefix metric name `traffic.ingress`, for example, would be
-`mtg.traffic.ingress`.
+| Name        | Values                     | Description                                   |
+|-------------|----------------------------|-----------------------------------------------|
+| ip_family   | `ipv4`, `ipv6`             | A version of the IP protocol.                 |
+| dc          |                            | A number of the Telegram DC for a connection. |
+| telegram_ip |                            | IP address of the Telegram server.            |
+| direction   | `to_client`, `from_client` | A direction of the traffic flow.              |
+| ip_list     | `allowlist`, `blocklist`   | A type of the IP list.                        |

SECURITY.md

@@ -0,0 +1,24 @@
+# Security Policy
+
+## Supported Versions
+
+We support 2 tracks: 2.x and 1.x
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 2.x     | :white_check_mark: |
+| 1.x     | :interrobang:      |
+| < 1.0   | :x:                |
+
+1.x has adtag support. We do not plan any active development there but we guarantee:
+
+1. Regular dependency updates
+2. Updates for Golang versions
+3. Security vulnerability fixes
+4. Merging small PRs
+
+2.x is in active development and have a full support.
+
+## Reporting a Vulnerability
+
+If you have found a vulnerability, please report about it to nineseconds@yandex.ru, telegram @9seconds or here in issues

antireplay/init.go

@@ -0,0 +1,17 @@
+// Antireplay package has cache implementations that are effective against
+// replay attacks.
+//
+// To understand more about replay attacks, please read documentation for
+// [mtglib.AntiReplayCache] interface. This package has a list of some
+// implementations of this interface.
+package antireplay
+
+const (
+	// DefaultStableBloomFilterMaxSize is a recommended byte size for a stable
+	// bloom filter.
+	DefaultStableBloomFilterMaxSize = 1024 * 1024 // 1MiB
+
+	// DefaultStableBloomFilterErrorRate is a recommended default error rate for a
+	// stable bloom filter.
+	DefaultStableBloomFilterErrorRate = 0.001
+)

antireplay/noop.go

@@ -0,0 +1,13 @@
+package antireplay
+
+import "github.com/9seconds/mtg/v2/mtglib"
+
+type noop struct{}
+
+func (n noop) SeenBefore(_ []byte) bool { return false }
+
+// NewNoop returns an implementation that does nothing. A corresponding method
+// always returns false, so this cache accepts everything you pass to it.
+func NewNoop() mtglib.AntiReplayCache {
+	return noop{}
+}

antireplay/noop_test.go

@@ -0,0 +1,26 @@
+package antireplay_test
+
+import (
+	"testing"
+
+	"github.com/9seconds/mtg/v2/antireplay"
+	"github.com/stretchr/testify/suite"
+)
+
+type NoopTestSuite struct {
+	suite.Suite
+}
+
+func (suite *NoopTestSuite) TestOp() {
+	filter := antireplay.NewNoop()
+
+	suite.False(filter.SeenBefore([]byte{1, 2, 3}))
+	suite.False(filter.SeenBefore([]byte{4, 5, 6}))
+	suite.False(filter.SeenBefore([]byte{1, 2, 3}))
+	suite.False(filter.SeenBefore([]byte{4, 5, 6}))
+}
+
+func TestNoop(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &NoopTestSuite{})
+}

antireplay/stable_bloom_filter.go

@@ -0,0 +1,51 @@
+package antireplay
+
+import (
+	"sync"
+
+	"github.com/9seconds/mtg/v2/mtglib"
+	"github.com/OneOfOne/xxhash"
+	boom "github.com/tylertreat/BoomFilters"
+)
+
+type stableBloomFilter struct {
+	filter boom.StableBloomFilter
+	mutex  sync.Mutex
+}
+
+func (s *stableBloomFilter) SeenBefore(digest []byte) bool {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	return s.filter.TestAndAdd(digest)
+}
+
+// NewStableBloomFilter returns an implementation of AntiReplayCache based on
+// stable bloom filter.
+//
+// http://webdocs.cs.ualberta.ca/~drafiei/papers/DupDet06Sigmod.pdf
+//
+// The basic idea of a stable bloom filter is quite simple: each time when you
+// set a new element, you randomly reset P elements. There is a hardcore math
+// which proves that if you choose this P correctly, you can maintain the same
+// error rate for a stream of elements.
+//
+// byteSize is the number of bytes you want to give to a bloom filter.
+// errorRate is desired false-positive error rate. If you want to use default
+// values, please pass 0 for byteSize and <0 for errorRate.
+func NewStableBloomFilter(byteSize uint, errorRate float64) mtglib.AntiReplayCache {
+	if byteSize == 0 {
+		byteSize = DefaultStableBloomFilterMaxSize
+	}
+
+	if errorRate < 0 {
+		errorRate = DefaultStableBloomFilterErrorRate
+	}
+
+	sf := boom.NewDefaultStableBloomFilter(byteSize*8, errorRate)
+	sf.SetHash(xxhash.New64())
+
+	return &stableBloomFilter{
+		filter: *sf,
+	}
+}

antireplay/stable_bloom_filter_test.go

@@ -0,0 +1,26 @@
+package antireplay_test
+
+import (
+	"testing"
+
+	"github.com/9seconds/mtg/v2/antireplay"
+	"github.com/stretchr/testify/suite"
+)
+
+type StableBloomFilterTestSuite struct {
+	suite.Suite
+}
+
+func (suite *StableBloomFilterTestSuite) TestOp() {
+	filter := antireplay.NewStableBloomFilter(500, 0.001)
+
+	suite.False(filter.SeenBefore([]byte{1, 2, 3}))
+	suite.False(filter.SeenBefore([]byte{4, 5, 6}))
+	suite.True(filter.SeenBefore([]byte{1, 2, 3}))
+	suite.True(filter.SeenBefore([]byte{4, 5, 6}))
+}
+
+func TestStableBloomFilter(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &StableBloomFilterTestSuite{})
+}

buildinfo.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"runtime/debug"
+	"sort"
+	"strconv"
+	"time"
+)
+
+var version = "dev" // has to be set by ldflags
+
+const (
+	buildInfoModuleStart byte = iota
+	buildInfoModuleFinish
+	buildInfoModuleDelimeter
+)
+
+func getVersion() string {
+	buildInfo, ok := debug.ReadBuildInfo()
+	if !ok {
+		return version
+	}
+
+	date := time.Now()
+	commit := ""
+	goVersion := buildInfo.GoVersion
+	dirtySuffix := ""
+
+	for _, setting := range buildInfo.Settings {
+		switch setting.Key {
+		case "vcs.time":
+			date, _ = time.Parse(time.RFC3339, setting.Value)
+		case "vcs.revision":
+			commit = setting.Value
+		case "vcs.modified":
+			if dirty, _ := strconv.ParseBool(setting.Value); dirty {
+				dirtySuffix = " [dirty]"
+			}
+		}
+	}
+
+	hasher := sha256.New()
+
+	checksumModule := func(mod *debug.Module) {
+		hasher.Write([]byte{buildInfoModuleStart})
+
+		io.WriteString(hasher, mod.Path) //nolint: errcheck
+		hasher.Write([]byte{buildInfoModuleDelimeter})
+
+		io.WriteString(hasher, mod.Version) //nolint: errcheck
+		hasher.Write([]byte{buildInfoModuleDelimeter})
+
+		io.WriteString(hasher, mod.Sum) //nolint: errcheck
+
+		hasher.Write([]byte{buildInfoModuleFinish})
+	}
+
+	io.WriteString(hasher, buildInfo.Path) //nolint: errcheck
+
+	binary.Write(hasher, binary.LittleEndian, uint64(1+len(buildInfo.Deps))) //nolint: errcheck
+
+	sort.Slice(buildInfo.Deps, func(i, j int) bool {
+		return buildInfo.Deps[i].Path > buildInfo.Deps[j].Path
+	})
+
+	checksumModule(&buildInfo.Main)
+
+	for _, module := range buildInfo.Deps {
+		checksumModule(module)
+	}
+
+	return fmt.Sprintf("%s (%s: %s on %s%s, modules checksum %s)",
+		version,
+		goVersion,
+		date.Format(time.RFC3339),
+		commit,
+		dirtySuffix,
+		base64.StdEncoding.EncodeToString(hasher.Sum(nil)))
+}

client/client.go

@@ -1,14 +0,0 @@
-package client
-
-import (
-	"context"
-	"net"
-
-	"github.com/9seconds/mtg/config"
-	"github.com/9seconds/mtg/mtproto"
-	"github.com/9seconds/mtg/wrappers"
-)
-
-// Init defines common method for initializing client connections.
-type Init func(context.Context, context.CancelFunc, net.Conn, string,
-	*config.Config) (wrappers.Wrap, *mtproto.ConnectionOpts, error)

client/direct.go

@@ -1,53 +0,0 @@
-package client
-
-import (
-	"context"
-	"net"
-	"time"
-
-	"github.com/juju/errors"
-
-	"github.com/9seconds/mtg/config"
-	"github.com/9seconds/mtg/mtproto"
-	"github.com/9seconds/mtg/obfuscated2"
-	"github.com/9seconds/mtg/wrappers"
-)
-
-const handshakeTimeout = 10 * time.Second
-
-// DirectInit initializes client connection for proxy which connects to
-// Telegram directly.
-func DirectInit(ctx context.Context, cancel context.CancelFunc, socket net.Conn,
-	connID string, conf *config.Config) (wrappers.Wrap, *mtproto.ConnectionOpts, error) {
-	tcpSocket := socket.(*net.TCPConn)
-	if err := tcpSocket.SetNoDelay(false); err != nil {
-		return nil, nil, errors.Annotate(err, "Cannot disable NO_DELAY to client socket")
-	}
-	if err := tcpSocket.SetReadBuffer(conf.ReadBufferSize); err != nil {
-		return nil, nil, errors.Annotate(err, "Cannot set read buffer size of client socket")
-	}
-	if err := tcpSocket.SetWriteBuffer(conf.WriteBufferSize); err != nil {
-		return nil, nil, errors.Annotate(err, "Cannot set write buffer size of client socket")
-	}
-
-	socket.SetReadDeadline(time.Now().Add(handshakeTimeout)) // nolint: errcheck, gosec
-	frame, err := obfuscated2.ExtractFrame(socket)
-	if err != nil {
-		return nil, nil, errors.Annotate(err, "Cannot extract frame")
-	}
-	socket.SetReadDeadline(time.Time{}) // nolint: errcheck, gosec
-
-	conn := wrappers.NewConn(ctx, cancel, socket, connID, wrappers.ConnPurposeClient, conf.PublicIPv4, conf.PublicIPv6)
-	obfs2, connOpts, err := obfuscated2.ParseObfuscated2ClientFrame(conf.Secret, frame)
-	if err != nil {
-		return nil, nil, errors.Annotate(err, "Cannot parse obfuscated frame")
-	}
-	connOpts.ConnectionProto = mtproto.ConnectionProtocolAny
-	connOpts.ClientAddr = conn.RemoteAddr()
-
-	conn = wrappers.NewStreamCipher(conn, obfs2.Encryptor, obfs2.Decryptor)
-
-	conn.Logger().Infow("Client connection initialized")
-
-	return conn, connOpts, nil
-}

client/middle.go

@@ -1,40 +0,0 @@
-package client
-
-import (
-	"context"
-	"net"
-
-	"github.com/9seconds/mtg/config"
-	"github.com/9seconds/mtg/mtproto"
-	"github.com/9seconds/mtg/wrappers"
-)
-
-// MiddleInit initializes client connection for proxy which has to
-// support promoted channels, connect to Telegram middle proxies etc.
-func MiddleInit(ctx context.Context, cancel context.CancelFunc, socket net.Conn,
-	connID string, conf *config.Config) (wrappers.Wrap, *mtproto.ConnectionOpts, error) {
-	conn, opts, err := DirectInit(ctx, cancel, socket, connID, conf)
-	if err != nil {
-		return nil, nil, err
-	}
-	connStream := conn.(wrappers.StreamReadWriteCloser)
-
-	var newConn wrappers.PacketReadWriteCloser
-	switch opts.ConnectionType {
-	case mtproto.ConnectionTypeAbridged:
-		newConn = wrappers.NewMTProtoAbridged(connStream, opts)
-	case mtproto.ConnectionTypeIntermediate:
-		newConn = wrappers.NewMTProtoIntermediate(connStream, opts)
-	case mtproto.ConnectionTypeSecure:
-		newConn = wrappers.NewMTProtoIntermediateSecure(connStream, opts)
-	default:
-		panic("Unknown connection type")
-	}
-
-	opts.ConnectionProto = mtproto.ConnectionProtocolIPv4
-	if socket.LocalAddr().(*net.TCPAddr).IP.To4() == nil {
-		opts.ConnectionProto = mtproto.ConnectionProtocolIPv6
-	}
-
-	return newConn, opts, err
-}

config/config.go

@@ -1,213 +0,0 @@
-package config
-
-import (
-	"bytes"
-	"encoding/hex"
-	"fmt"
-	"net"
-	"strconv"
-
-	"github.com/juju/errors"
-	statsd "gopkg.in/alexcesaro/statsd.v2"
-)
-
-// Config represents common configuration of mtg.
-type Config struct {
-	Debug      bool
-	Verbose    bool
-	SecureMode bool
-	SecureOnly bool
-
-	ReadBufferSize  int
-	WriteBufferSize int
-
-	BindPort       uint16
-	PublicIPv4Port uint16
-	PublicIPv6Port uint16
-	StatsPort      uint16
-
-	BindIP     net.IP
-	PublicIPv4 net.IP
-	PublicIPv6 net.IP
-	StatsIP    net.IP
-
-	StatsD struct {
-		Addr       net.Addr
-		Prefix     string
-		Tags       map[string]string
-		TagsFormat statsd.TagFormat
-		Enabled    bool
-	}
-
-	Secret []byte
-	AdTag  []byte
-}
-
-// URLs contains links to the proxy (tg://, t.me) and their QR codes.
-type URLs struct {
-	TG        string `json:"tg_url"`
-	TMe       string `json:"tme_url"`
-	TGQRCode  string `json:"tg_qrcode"`
-	TMeQRCode string `json:"tme_qrcode"`
-}
-
-// IPURLs contains links to both ipv4 and ipv6 of the proxy.
-type IPURLs struct {
-	IPv4      URLs   `json:"ipv4"`
-	IPv6      URLs   `json:"ipv6"`
-	BotSecret string `json:"secret_for_mtproxybot"`
-}
-
-// BindAddr returns connection for this server to bind to.
-func (c *Config) BindAddr() string {
-	return getAddr(c.BindIP, c.BindPort)
-}
-
-// StatAddr returns connection string to the stats API.
-func (c *Config) StatAddr() string {
-	return getAddr(c.StatsIP, c.StatsPort)
-}
-
-// UseMiddleProxy defines if this proxy has to connect middle proxies
-// which supports promoted channels or directly access Telegram.
-func (c *Config) UseMiddleProxy() bool {
-	return len(c.AdTag) > 0
-}
-
-// BotSecretString returns secret string which should work with MTProxybot.
-func (c *Config) BotSecretString() string {
-	return hex.EncodeToString(c.Secret)
-}
-
-// SecretString returns a secret in a form entered on the start of the
-// application.
-func (c *Config) SecretString() string {
-	secret := c.BotSecretString()
-	if c.SecureMode {
-		return "dd" + secret
-	}
-	return secret
-}
-
-// GetURLs returns configured IPURLs instance with links to this server.
-func (c *Config) GetURLs() IPURLs {
-	urls := IPURLs{}
-	secret := c.SecretString()
-	if c.PublicIPv4 != nil {
-		urls.IPv4 = getURLs(c.PublicIPv4, c.PublicIPv4Port, secret)
-	}
-	if c.PublicIPv6 != nil {
-		urls.IPv6 = getURLs(c.PublicIPv6, c.PublicIPv6Port, secret)
-	}
-	urls.BotSecret = c.BotSecretString()
-
-	return urls
-}
-
-func getAddr(host fmt.Stringer, port uint16) string {
-	return net.JoinHostPort(host.String(), strconv.Itoa(int(port)))
-}
-
-// NewConfig returns new configuration. If required, it manages and
-// fetches data from external sources. Parameters passed to this
-// function, should come from command line arguments.
-func NewConfig(debug, verbose bool, // nolint: gocyclo
-	writeBufferSize, readBufferSize uint32,
-	bindIP, publicIPv4, publicIPv6, statsIP net.IP,
-	bindPort, publicIPv4Port, publicIPv6Port, statsPort, statsdPort uint16,
-	statsdIP, statsdNetwork, statsdPrefix, statsdTagsFormat string,
-	statsdTags map[string]string,
-	secureOnly bool,
-	secret, adtag []byte) (*Config, error) {
-	secureMode := secureOnly
-	if bytes.HasPrefix(secret, []byte{0xdd}) && len(secret) == 17 {
-		secureMode = true
-		secret = bytes.TrimPrefix(secret, []byte{0xdd})
-	} else if len(secret) != 16 {
-		return nil, errors.New("Telegram demands secret of length 32")
-	}
-
-	var err error
-	if publicIPv4 == nil {
-		publicIPv4, err = getGlobalIPv4()
-		if err != nil {
-			publicIPv4 = nil
-		} else if publicIPv4.To4() == nil {
-			return nil, errors.Errorf("IP %s is not IPv4", publicIPv4.String())
-		}
-	}
-	if publicIPv4Port == 0 {
-		publicIPv4Port = bindPort
-	}
-
-	if publicIPv6 == nil {
-		publicIPv6, err = getGlobalIPv6()
-		if err != nil {
-			publicIPv6 = nil
-		} else if publicIPv6.To4() != nil {
-			return nil, errors.Errorf("IP %s is not IPv6", publicIPv6.String())
-		}
-	}
-	if publicIPv6Port == 0 {
-		publicIPv6Port = bindPort
-	}
-
-	if statsIP == nil {
-		statsIP = publicIPv4
-	}
-
-	conf := &Config{
-		Debug:           debug,
-		Verbose:         verbose,
-		SecureOnly:      secureOnly,
-		BindIP:          bindIP,
-		BindPort:        bindPort,
-		PublicIPv4:      publicIPv4,
-		PublicIPv4Port:  publicIPv4Port,
-		PublicIPv6:      publicIPv6,
-		PublicIPv6Port:  publicIPv6Port,
-		StatsIP:         statsIP,
-		StatsPort:       statsPort,
-		Secret:          secret,
-		AdTag:           adtag,
-		SecureMode:      secureMode,
-		ReadBufferSize:  int(readBufferSize),
-		WriteBufferSize: int(writeBufferSize),
-	}
-
-	if statsdIP != "" {
-		conf.StatsD.Enabled = true
-		conf.StatsD.Prefix = statsdPrefix
-		conf.StatsD.Tags = statsdTags
-
-		var (
-			addr net.Addr
-			err  error
-		)
-		hostPort := net.JoinHostPort(statsdIP, strconv.Itoa(int(statsdPort)))
-		switch statsdNetwork {
-		case "tcp":
-			addr, err = net.ResolveTCPAddr("tcp", hostPort)
-		case "udp":
-			addr, err = net.ResolveUDPAddr("udp", hostPort)
-		default:
-			err = errors.Errorf("Unknown network %s", statsdNetwork)
-		}
-		if err != nil {
-			return nil, errors.Annotate(err, "Cannot resolve statsd address")
-		}
-		conf.StatsD.Addr = addr
-
-		switch statsdTagsFormat {
-		case "datadog":
-			conf.StatsD.TagsFormat = statsd.Datadog
-		case "influxdb":
-			conf.StatsD.TagsFormat = statsd.InfluxDB
-		case "":
-		default:
-			return nil, errors.Errorf("Unknown tags format %s", statsdTagsFormat)
-		}
-	}
-
-	return conf, nil
-}

config/global_ips.go

@@ -1,52 +0,0 @@
-package config
-
-import (
-	"context"
-	"io/ioutil"
-	"net"
-	"net/http"
-	"strings"
-
-	"github.com/juju/errors"
-)
-
-const ifconfigAddress = "https://ifconfig.co/ip"
-
-func getGlobalIPv4() (net.IP, error) {
-	return fetchIP("tcp4")
-}
-
-func getGlobalIPv6() (net.IP, error) {
-	return fetchIP("tcp6")
-}
-
-func fetchIP(network string) (net.IP, error) {
-	dialer := &net.Dialer{DualStack: false}
-	client := &http.Client{
-		Jar: nil,
-		Transport: &http.Transport{
-			DialContext: func(ctx context.Context, _, addr string) (net.Conn, error) {
-				return dialer.DialContext(ctx, network, addr)
-			},
-		},
-	}
-
-	resp, err := client.Get(ifconfigAddress)
-	if err != nil {
-		return nil, err
-	}
-	defer resp.Body.Close() // nolint: errcheck
-
-	respDataBytes, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		return nil, err
-	}
-	respData := strings.TrimSpace(string(respDataBytes))
-
-	ip := net.ParseIP(respData)
-	if ip == nil {
-		return nil, errors.Errorf("ifconfig.co returns incorrect IP %s", respData)
-	}
-
-	return ip, nil
-}

config/urls.go

@@ -1,58 +0,0 @@
-package config
-
-import (
-	"net"
-	"net/url"
-	"strconv"
-)
-
-func getURLs(addr net.IP, port uint16, secret string) (urls URLs) {
-	values := url.Values{}
-	values.Set("server", addr.String())
-	values.Set("port", strconv.Itoa(int(port)))
-	values.Set("secret", secret)
-
-	urls.TG = makeTGURL(values)
-	urls.TMe = makeTMeURL(values)
-	urls.TGQRCode = makeQRCodeURL(urls.TG)
-	urls.TMeQRCode = makeQRCodeURL(urls.TG)
-
-	return
-}
-
-func makeTGURL(values url.Values) string {
-	tgURL := url.URL{
-		Scheme:   "tg",
-		Host:     "proxy",
-		RawQuery: values.Encode(),
-	}
-
-	return tgURL.String()
-}
-
-func makeTMeURL(values url.Values) string {
-	tMeURL := url.URL{
-		Scheme:   "https",
-		Host:     "t.me",
-		Path:     "proxy",
-		RawQuery: values.Encode(),
-	}
-
-	return tMeURL.String()
-}
-
-func makeQRCodeURL(data string) string {
-	qr := url.URL{
-		Scheme: "https",
-		Host:   "api.qrserver.com",
-		Path:   "v1/create-qr-code",
-	}
-
-	values := url.Values{}
-	values.Set("qzone", "4")
-	values.Set("format", "svg")
-	values.Set("data", data)
-	qr.RawQuery = values.Encode()
-
-	return qr.String()
-}

essentials/conns.go

@@ -0,0 +1,26 @@
+package essentials
+
+import (
+	"io"
+	"net"
+)
+
+// CloseableReader is an [io.Reader] interface that can close its reading end.
+type CloseableReader interface {
+	io.Reader
+	CloseRead() error
+}
+
+// CloseableWriter is an [io.Writer] that can close its writing end.
+type CloseableWriter interface {
+	io.Writer
+	CloseWrite() error
+}
+
+// Conn is an extension of [net.Conn] that can close its ends. This mostly
+// implies TCP connections.
+type Conn interface {
+	net.Conn
+	CloseableReader
+	CloseableWriter
+}

essentials/doc.go

@@ -0,0 +1,6 @@
+// This is a minimal package that contains _essentials_ of mtglib and its
+// complimentary packages. This is mostly required to comply some interfaces
+// between mtglib and its internals to avoid circular dependencies.
+//
+// This package should contain only bare minimum and mostly technical.
+package essentials

events/event_stream.go

@@ -0,0 +1,110 @@
+package events
+
+import (
+	"context"
+	"math/rand"
+	"runtime"
+
+	"github.com/9seconds/mtg/v2/mtglib"
+	"github.com/OneOfOne/xxhash"
+)
+
+// EventStream is a default implementation of the [mtglib.EventStream]
+// interface.
+//
+// EventStream manages a set of goroutines, observers. Main
+// responsibility of the event stream is to route an event to relevant
+// observer based on some hash so each observer will have all events
+// which belong to some stream id.
+//
+// Thus, EventStream can spawn many observers.
+type EventStream struct {
+	ctx       context.Context
+	ctxCancel context.CancelFunc
+	chans     []chan mtglib.Event
+}
+
+// Send starts delivering of the message to observer with respect to a
+// given context If context is closed, message could be not delivered.
+func (e EventStream) Send(ctx context.Context, evt mtglib.Event) {
+	var chanNo uint32
+
+	if streamID := evt.StreamID(); streamID != "" {
+		chanNo = xxhash.ChecksumString32(streamID)
+	} else {
+		chanNo = rand.Uint32()
+	}
+
+	select {
+	case <-ctx.Done():
+	case <-e.ctx.Done():
+	case e.chans[int(chanNo)%len(e.chans)] <- evt:
+	}
+}
+
+// Shutdown stops an event stream pipeline.
+func (e EventStream) Shutdown() {
+	e.ctxCancel()
+}
+
+// NewEventStream builds a new default event stream.
+//
+// If you give an empty array of observers, then NoopObserver is going
+// to be used. If you give many observers, then they will process a
+// message concurrently.
+func NewEventStream(observerFactories []ObserverFactory) EventStream {
+	if len(observerFactories) == 0 {
+		observerFactories = append(observerFactories, NewNoopObserver)
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	rv := EventStream{
+		ctx:       ctx,
+		ctxCancel: cancel,
+		chans:     make([]chan mtglib.Event, runtime.NumCPU()),
+	}
+
+	for i := 0; i < runtime.NumCPU(); i++ {
+		rv.chans[i] = make(chan mtglib.Event, 1)
+
+		if len(observerFactories) == 1 {
+			go eventStreamProcessor(ctx, rv.chans[i], observerFactories[0]())
+		} else {
+			go eventStreamProcessor(ctx, rv.chans[i], newMultiObserver(observerFactories))
+		}
+	}
+
+	return rv
+}
+
+func eventStreamProcessor(ctx context.Context, eventChan <-chan mtglib.Event, observer Observer) { //nolint: cyclop
+	defer observer.Shutdown()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case evt := <-eventChan:
+			switch typedEvt := evt.(type) {
+			case mtglib.EventTraffic:
+				observer.EventTraffic(typedEvt)
+			case mtglib.EventStart:
+				observer.EventStart(typedEvt)
+			case mtglib.EventFinish:
+				observer.EventFinish(typedEvt)
+			case mtglib.EventConnectedToDC:
+				observer.EventConnectedToDC(typedEvt)
+			case mtglib.EventDomainFronting:
+				observer.EventDomainFronting(typedEvt)
+			case mtglib.EventIPBlocklisted:
+				observer.EventIPBlocklisted(typedEvt)
+			case mtglib.EventConcurrencyLimited:
+				observer.EventConcurrencyLimited(typedEvt)
+			case mtglib.EventReplayAttack:
+				observer.EventReplayAttack(typedEvt)
+			case mtglib.EventIPListSize:
+				observer.EventIPListSize(typedEvt)
+			}
+		}
+	}
+}

events/event_stream_test.go

@@ -0,0 +1,241 @@
+package events_test
+
+import (
+	"context"
+	"net"
+	"testing"
+	"time"
+
+	"github.com/9seconds/mtg/v2/events"
+	"github.com/9seconds/mtg/v2/mtglib"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/suite"
+)
+
+type EventStreamTestSuite struct {
+	suite.Suite
+
+	ctx           context.Context
+	ctxCancel     context.CancelFunc
+	observerMock1 *ObserverMock
+	observerMock2 *ObserverMock
+	stream        events.EventStream
+}
+
+func (suite *EventStreamTestSuite) SetupTest() {
+	suite.ctx, suite.ctxCancel = context.WithCancel(context.Background())
+
+	suite.observerMock1 = &ObserverMock{}
+	suite.observerMock2 = &ObserverMock{}
+
+	suite.observerMock1.On("Shutdown")
+	suite.observerMock2.On("Shutdown")
+
+	factories := make([]events.ObserverFactory, 2)
+	factories[0] = func() events.Observer { return suite.observerMock1 }
+	factories[1] = func() events.Observer { return suite.observerMock2 }
+
+	suite.stream = events.NewEventStream(factories)
+}
+
+func (suite *EventStreamTestSuite) TestEventStart() {
+	evt := mtglib.NewEventStart("connID", net.ParseIP("10.0.0.1"))
+
+	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
+		v.
+			On("EventStart", mock.Anything).
+			Once().
+			Run(func(args mock.Arguments) {
+				caught, ok := args.Get(0).(mtglib.EventStart)
+
+				suite.True(ok)
+				suite.Equal(evt.RemoteIP.String(), caught.RemoteIP.String())
+				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
+			})
+	}
+
+	suite.stream.Send(suite.ctx, evt)
+	time.Sleep(100 * time.Millisecond)
+}
+
+func (suite *EventStreamTestSuite) TestEventConnectedToDC() {
+	evt := mtglib.NewEventConnectedToDC("connID", net.ParseIP("10.0.0.1"), 3)
+
+	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
+		v.
+			On("EventConnectedToDC", mock.Anything).
+			Once().
+			Run(func(args mock.Arguments) {
+				caught, ok := args.Get(0).(mtglib.EventConnectedToDC)
+
+				suite.True(ok)
+				suite.Equal(evt.RemoteIP.String(), caught.RemoteIP.String())
+				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.DC, caught.DC)
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
+			})
+	}
+
+	suite.stream.Send(suite.ctx, evt)
+	time.Sleep(100 * time.Millisecond)
+}
+
+func (suite *EventStreamTestSuite) TestEventDomainFronting() {
+	evt := mtglib.NewEventDomainFronting("connID")
+
+	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
+		v.
+			On("EventDomainFronting", mock.Anything).
+			Once().
+			Run(func(args mock.Arguments) {
+				caught, ok := args.Get(0).(mtglib.EventDomainFronting)
+
+				suite.True(ok)
+				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
+			})
+	}
+
+	suite.stream.Send(suite.ctx, evt)
+	time.Sleep(100 * time.Millisecond)
+}
+
+func (suite *EventStreamTestSuite) TestEventTraffic() {
+	evt := mtglib.NewEventTraffic("connID", 1024, true)
+
+	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
+		v.
+			On("EventTraffic", mock.Anything).
+			Once().
+			Run(func(args mock.Arguments) {
+				caught, ok := args.Get(0).(mtglib.EventTraffic)
+
+				suite.True(ok)
+				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
+				suite.Equal(evt.Traffic, caught.Traffic)
+				suite.Equal(evt.IsRead, caught.IsRead)
+			})
+	}
+
+	suite.stream.Send(suite.ctx, evt)
+	time.Sleep(100 * time.Millisecond)
+}
+
+func (suite *EventStreamTestSuite) TestEventFinish() {
+	evt := mtglib.NewEventFinish("connID")
+
+	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
+		v.
+			On("EventFinish", mock.Anything).
+			Once().
+			Run(func(args mock.Arguments) {
+				caught, ok := args.Get(0).(mtglib.EventFinish)
+
+				suite.True(ok)
+				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
+			})
+	}
+
+	suite.stream.Send(suite.ctx, evt)
+	time.Sleep(100 * time.Millisecond)
+}
+
+func (suite *EventStreamTestSuite) TestEventConcurrencyLimited() {
+	evt := mtglib.NewEventConcurrencyLimited()
+
+	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
+		v.
+			On("EventConcurrencyLimited", mock.Anything).
+			Once().
+			Run(func(args mock.Arguments) {
+				caught, ok := args.Get(0).(mtglib.EventConcurrencyLimited)
+
+				suite.True(ok)
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
+				suite.Empty(evt.StreamID())
+			})
+	}
+
+	suite.stream.Send(suite.ctx, evt)
+	time.Sleep(100 * time.Millisecond)
+}
+
+func (suite *EventStreamTestSuite) TestEventIPBlocklisted() {
+	evt := mtglib.NewEventIPBlocklisted(net.ParseIP("10.0.0.10"))
+
+	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
+		v.
+			On("EventIPBlocklisted", mock.Anything).
+			Once().
+			Run(func(args mock.Arguments) {
+				caught, ok := args.Get(0).(mtglib.EventIPBlocklisted)
+
+				suite.True(ok)
+				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
+				suite.Equal(evt.RemoteIP.String(), caught.RemoteIP.String())
+			})
+	}
+
+	suite.stream.Send(suite.ctx, evt)
+	time.Sleep(100 * time.Millisecond)
+}
+
+func (suite *EventStreamTestSuite) TestEventReplayAttack() {
+	evt := mtglib.NewEventReplayAttack("CONNID")
+
+	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
+		v.
+			On("EventReplayAttack", mock.Anything).
+			Once().
+			Run(func(args mock.Arguments) {
+				caught, ok := args.Get(0).(mtglib.EventReplayAttack)
+
+				suite.True(ok)
+				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
+			})
+	}
+
+	suite.stream.Send(suite.ctx, evt)
+	time.Sleep(100 * time.Millisecond)
+}
+
+func (suite *EventStreamTestSuite) TestEventIPListSize() {
+	evt := mtglib.NewEventIPListSize(10, true)
+
+	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
+		v.
+			On("EventIPListSize", mock.Anything).
+			Once().
+			Run(func(args mock.Arguments) {
+				caught, ok := args.Get(0).(mtglib.EventIPListSize)
+
+				suite.True(ok)
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
+				suite.Equal(evt.Size, caught.Size)
+				suite.Equal(evt.IsBlockList, caught.IsBlockList)
+			})
+	}
+
+	suite.stream.Send(suite.ctx, evt)
+	time.Sleep(100 * time.Millisecond)
+}
+
+func (suite *EventStreamTestSuite) TearDownTest() {
+	suite.stream.Shutdown()
+	suite.ctxCancel()
+
+	time.Sleep(100 * time.Millisecond)
+
+	suite.observerMock1.AssertExpectations(suite.T())
+	suite.observerMock2.AssertExpectations(suite.T())
+}
+
+func TestEventStream(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &EventStreamTestSuite{})
+}

events/init.go

@@ -0,0 +1,72 @@
+// Events has a default implementations of EventStream for mtglib.
+//
+// Please see documentation for [mtglib.EventStream] interface to get an idea
+// of such an abstraction. This package has implementations for the default
+// event stream.
+//
+// Default event stream has a list of its own concepts. First, all it does is a
+// routing of messages to known observers. It takes an event, defines its type
+// and pass this message to a method of the observer.
+//
+// There might be many observers, but default event stream has a guarantee
+// though. It uses StreamID as a sharding key and guarantees that a message
+// with the same StreamID will be devlivered to the same observer instance. So,
+// each producer is guarateed to get all relevant messages related to the same
+// session. It is not possible that it will get EventFinish if it has not seen
+// EventStart for that session yet.
+package events
+
+import "github.com/9seconds/mtg/v2/mtglib"
+
+// Observer is an instance that listens for the incoming events.
+//
+// As it is said in the package description, the default event stream
+// guarantees that all events with the same StreamID are going to be routed to
+// the same instance of the observer. So, there is no need to synchronize
+// information about streams between many observers instances, they can have
+// their local storage.
+type Observer interface {
+	// EventStart reacts on incoming mtglib.EventStart event.
+	EventStart(mtglib.EventStart)
+
+	// EventFinish reacts on incoming mtglib.EventFinish event.
+	EventFinish(mtglib.EventFinish)
+
+	// EventConnectedToDC reacts on incoming mtglib.EventConnectedToDC
+	// event.
+	EventConnectedToDC(mtglib.EventConnectedToDC)
+
+	// EventDomainFronting reacts on incoming mtglib.EventDomainFronting
+	// event.
+	EventDomainFronting(mtglib.EventDomainFronting)
+
+	// EventTraffic reacts on incoming mtglib.EventTraffic event.
+	EventTraffic(mtglib.EventTraffic)
+
+	// EventConcurrencyLimited reacts on incoming
+	// mtglib.EventConcurrencyLimited event.
+	EventConcurrencyLimited(mtglib.EventConcurrencyLimited)
+
+	// EventIPBlocklisted reacts on incoming mtglib.EventIPBlocklisted event.
+	EventIPBlocklisted(mtglib.EventIPBlocklisted)
+
+	// EventReplayAttack reacts on incoming mtglib.EventReplayAttack event.
+	EventReplayAttack(mtglib.EventReplayAttack)
+
+	// EventIPListSize reacts on incoming mtglib.EventIPListSize
+	EventIPListSize(mtglib.EventIPListSize)
+
+	// Shutdown stop observer. Default event stream guarantees:
+	//   1. If shutdown is executed, it is executed only once
+	//   2. Observer won't receieve any new message after this
+	//      function call.
+	Shutdown()
+}
+
+// ObserverFactory creates a new instance of the observer.
+//
+// Default event stream creates a small set of goroutines to manage incoming
+// messages. Each message is routed to an appropriate observer based on a
+// sharding key, stream id. So, it is possible that an instance of mtg will
+// have many observer instances, not a single one.
+type ObserverFactory func() Observer

events/init_test.go

@@ -0,0 +1,50 @@
+package events_test
+
+import (
+	"github.com/9seconds/mtg/v2/mtglib"
+	"github.com/stretchr/testify/mock"
+)
+
+type ObserverMock struct {
+	mock.Mock
+}
+
+func (o *ObserverMock) EventStart(evt mtglib.EventStart) {
+	o.Called(evt)
+}
+
+func (o *ObserverMock) EventConnectedToDC(evt mtglib.EventConnectedToDC) {
+	o.Called(evt)
+}
+
+func (o *ObserverMock) EventDomainFronting(evt mtglib.EventDomainFronting) {
+	o.Called(evt)
+}
+
+func (o *ObserverMock) EventTraffic(evt mtglib.EventTraffic) {
+	o.Called(evt)
+}
+
+func (o *ObserverMock) EventFinish(evt mtglib.EventFinish) {
+	o.Called(evt)
+}
+
+func (o *ObserverMock) EventConcurrencyLimited(evt mtglib.EventConcurrencyLimited) {
+	o.Called(evt)
+}
+
+func (o *ObserverMock) EventIPBlocklisted(evt mtglib.EventIPBlocklisted) {
+	o.Called(evt)
+}
+
+func (o *ObserverMock) EventReplayAttack(evt mtglib.EventReplayAttack) {
+	o.Called(evt)
+}
+
+func (o *ObserverMock) EventIPListSize(evt mtglib.EventIPListSize) {
+	o.Called(evt)
+}
+
+func (o *ObserverMock) Shutdown() {
+	o.Called()
+}

events/multi_observer.go

@@ -0,0 +1,164 @@
+package events
+
+import (
+	"sync"
+
+	"github.com/9seconds/mtg/v2/mtglib"
+)
+
+type multiObserver struct {
+	observers []Observer
+}
+
+func (m multiObserver) EventStart(evt mtglib.EventStart) {
+	wg := &sync.WaitGroup{}
+	wg.Add(len(m.observers))
+
+	for _, v := range m.observers {
+		go func(obs Observer) {
+			defer wg.Done()
+
+			obs.EventStart(evt)
+		}(v)
+	}
+
+	wg.Wait()
+}
+
+func (m multiObserver) EventConnectedToDC(evt mtglib.EventConnectedToDC) {
+	wg := &sync.WaitGroup{}
+	wg.Add(len(m.observers))
+
+	for _, v := range m.observers {
+		go func(obs Observer) {
+			defer wg.Done()
+
+			obs.EventConnectedToDC(evt)
+		}(v)
+	}
+
+	wg.Wait()
+}
+
+func (m multiObserver) EventDomainFronting(evt mtglib.EventDomainFronting) {
+	wg := &sync.WaitGroup{}
+	wg.Add(len(m.observers))
+
+	for _, v := range m.observers {
+		go func(obs Observer) {
+			defer wg.Done()
+
+			obs.EventDomainFronting(evt)
+		}(v)
+	}
+
+	wg.Wait()
+}
+
+func (m multiObserver) EventTraffic(evt mtglib.EventTraffic) {
+	wg := &sync.WaitGroup{}
+	wg.Add(len(m.observers))
+
+	for _, v := range m.observers {
+		go func(obs Observer) {
+			defer wg.Done()
+
+			obs.EventTraffic(evt)
+		}(v)
+	}
+
+	wg.Wait()
+}
+
+func (m multiObserver) EventFinish(evt mtglib.EventFinish) {
+	wg := &sync.WaitGroup{}
+	wg.Add(len(m.observers))
+
+	for _, v := range m.observers {
+		go func(obs Observer) {
+			defer wg.Done()
+
+			obs.EventFinish(evt)
+		}(v)
+	}
+
+	wg.Wait()
+}
+
+func (m multiObserver) EventConcurrencyLimited(evt mtglib.EventConcurrencyLimited) {
+	wg := &sync.WaitGroup{}
+	wg.Add(len(m.observers))
+
+	for _, v := range m.observers {
+		go func(obs Observer) {
+			defer wg.Done()
+
+			obs.EventConcurrencyLimited(evt)
+		}(v)
+	}
+
+	wg.Wait()
+}
+
+func (m multiObserver) EventIPBlocklisted(evt mtglib.EventIPBlocklisted) {
+	wg := &sync.WaitGroup{}
+	wg.Add(len(m.observers))
+
+	for _, v := range m.observers {
+		go func(obs Observer) {
+			defer wg.Done()
+
+			obs.EventIPBlocklisted(evt)
+		}(v)
+	}
+
+	wg.Wait()
+}
+
+func (m multiObserver) EventReplayAttack(evt mtglib.EventReplayAttack) {
+	wg := &sync.WaitGroup{}
+	wg.Add(len(m.observers))
+
+	for _, v := range m.observers {
+		go func(obs Observer) {
+			defer wg.Done()
+
+			obs.EventReplayAttack(evt)
+		}(v)
+	}
+
+	wg.Wait()
+}
+
+func (m multiObserver) EventIPListSize(evt mtglib.EventIPListSize) {
+	wg := &sync.WaitGroup{}
+	wg.Add(len(m.observers))
+
+	for _, v := range m.observers {
+		go func(obs Observer) {
+			defer wg.Done()
+
+			obs.EventIPListSize(evt)
+		}(v)
+	}
+
+	wg.Wait()
+}
+
+func (m multiObserver) Shutdown() {
+	for _, v := range m.observers {
+		v.Shutdown()
+	}
+}
+
+func newMultiObserver(factories []ObserverFactory) Observer {
+	observers := make([]Observer, len(factories))
+
+	for i, v := range factories {
+		observers[i] = v()
+	}
+
+	return multiObserver{
+		observers: observers,
+	}
+}

events/noop.go

@@ -0,0 +1,34 @@
+package events
+
+import (
+	"context"
+
+	"github.com/9seconds/mtg/v2/mtglib"
+)
+
+type noop struct{}
+
+func (n noop) Send(ctx context.Context, evt mtglib.Event) {}
+
+// NewNoopStream creates a stream which discards each message.
+func NewNoopStream() mtglib.EventStream {
+	return noop{}
+}
+
+type noopObserver struct{}
+
+func (n noopObserver) EventStart(_ mtglib.EventStart)                           {}
+func (n noopObserver) EventConnectedToDC(_ mtglib.EventConnectedToDC)           {}
+func (n noopObserver) EventDomainFronting(_ mtglib.EventDomainFronting)         {}
+func (n noopObserver) EventTraffic(_ mtglib.EventTraffic)                       {}
+func (n noopObserver) EventFinish(_ mtglib.EventFinish)                         {}
+func (n noopObserver) EventConcurrencyLimited(_ mtglib.EventConcurrencyLimited) {}
+func (n noopObserver) EventIPBlocklisted(_ mtglib.EventIPBlocklisted)           {}
+func (n noopObserver) EventReplayAttack(_ mtglib.EventReplayAttack)             {}
+func (n noopObserver) EventIPListSize(_ mtglib.EventIPListSize)                 {}
+func (n noopObserver) Shutdown()                                                {}
+
+// NewNoopObserver creates an observer which discards each message.
+func NewNoopObserver() Observer {
+	return noopObserver{}
+}

events/noop_test.go

@@ -0,0 +1,81 @@
+package events_test
+
+import (
+	"context"
+	"net"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/events"
+	"github.com/9seconds/mtg/v2/mtglib"
+	"github.com/stretchr/testify/suite"
+)
+
+type NoopTestSuite struct {
+	suite.Suite
+
+	testData map[string]mtglib.Event
+	ctx      context.Context
+}
+
+func (suite *NoopTestSuite) SetupSuite() {
+	suite.testData = map[string]mtglib.Event{
+		"start":               mtglib.NewEventStart("connID", net.ParseIP("127.0.0.1")),
+		"connected-to-dc":     mtglib.NewEventConnectedToDC("connID", net.ParseIP("127.1.0.1"), 2),
+		"domain-fronting":     mtglib.NewEventDomainFronting("connID"),
+		"traffic":             mtglib.NewEventTraffic("connID", 1000, true),
+		"finish":              mtglib.NewEventFinish("connID"),
+		"concurrency-limited": mtglib.NewEventConcurrencyLimited(),
+		"ip-blacklisted":      mtglib.NewEventIPBlocklisted(net.ParseIP("10.0.0.10")),
+		"replay-attack":       mtglib.NewEventReplayAttack("connID"),
+		"ip-list-size":        mtglib.NewEventIPListSize(10, true),
+	}
+	suite.ctx = context.Background()
+}
+
+func (suite *NoopTestSuite) TestStream() {
+	stream := events.NewNoopStream()
+
+	for name, v := range suite.testData {
+		value := v
+
+		suite.T().Run(name, func(t *testing.T) {
+			stream.Send(suite.ctx, value)
+		})
+	}
+}
+
+func (suite *NoopTestSuite) TestObserver() {
+	observer := events.NewNoopObserver()
+
+	for name, v := range suite.testData {
+		value := v
+
+		suite.T().Run(name, func(t *testing.T) {
+			switch typedEvt := value.(type) {
+			case mtglib.EventStart:
+				observer.EventStart(typedEvt)
+			case mtglib.EventConnectedToDC:
+				observer.EventConnectedToDC(typedEvt)
+			case mtglib.EventDomainFronting:
+				observer.EventDomainFronting(typedEvt)
+			case mtglib.EventFinish:
+				observer.EventFinish(typedEvt)
+			case mtglib.EventConcurrencyLimited:
+				observer.EventConcurrencyLimited(typedEvt)
+			case mtglib.EventIPBlocklisted:
+				observer.EventIPBlocklisted(typedEvt)
+			case mtglib.EventReplayAttack:
+				observer.EventReplayAttack(typedEvt)
+			case mtglib.EventIPListSize:
+				observer.EventIPListSize(typedEvt)
+			}
+		})
+	}
+
+	observer.Shutdown()
+}
+
+func TestNoop(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &NoopTestSuite{})
+}

example.config.toml

@@ -0,0 +1,231 @@
+# This is an example of the configuration file for mtg. You actually can
+# run mtg with it. It starts a proxy on all interfaces with a secret
+# ee367a189aee18fa31c190054efd4a8e9573746f726167652e676f6f676c65617069732e636f6d
+#
+# It has all possible options with default values. So, a real world
+# configuration file should contain only those options you are going to
+# use. You do not need to enumerate all of them. In other words, each
+# option here has a default value. If you comment a key-value pair, it
+# should not make any effect.
+#
+# stats is the only exception.
+
+# Debug starts application in debug mode. It starts to be quite verbose
+# in output. Actually, the idea is that you run it in debug mode only if
+# you have any issue.
+debug = true
+
+# A secret. Please remember that mtg supports only FakeTLS mode, legacy
+# simple and secured mode are prohibited. For you it means that secret
+# should either be base64-encoded or starts with ee.
+secret = "ee367a189aee18fa31c190054efd4a8e9573746f726167652e676f6f676c65617069732e636f6d"
+
+# Host:port pair to run proxy on.
+bind-to = "0.0.0.0:3128"
+
+# Defines how many concurrent connections are allowed to this proxy.
+# All other incoming connections are going to be dropped.
+concurrency = 8192
+
+# A size of user-space buffer for TCP to use. Since we do 2 connections,
+# then we have tcp-buffer * (4 + 2) per each connection: read/write for
+# each connection + 2 copy buffers to pump the data between sockets.
+#
+# Deprecated: this setting is no longer makes any effect.
+# tcp-buffer = "4kb"
+
+# Sometimes you want to enforce mtg to use some types of
+# IP connectivity to Telegram. We have 4 modes:
+#   - prefer-ipv6:
+#     We can use both ipv4 and ipv6 but ipv6 has a preference
+#   - prefer-ipv4:
+#     We can use both ipv4 and ipv6 but ipv4 has a preference
+#   - only-ipv6:
+#     Only ipv6 connectivity is used
+#   - only-ipv4:
+#     Only ipv4 connectivity is used
+prefer-ip = "prefer-ipv6"
+
+# FakeTLS uses domain fronting protection. So it needs to know a port to
+# access.
+domain-fronting-port = 443
+
+# FakeTLS can compare timestamps to prevent probes. Each message has
+# encrypted timestamp. So, mtg can compare this timestamp and decide if
+# we need to proceed with connection or not.
+#
+# Sometimes time can be skewed so we accept all messages within a
+# time range of this parameter.
+tolerate-time-skewness = "5s"
+
+# Telegram has a concept of DC. You can think about DC as a number of a cluster
+# with a certain purpose. Some clusters serve media, some - messages, some rule
+# channels and so on. But sometimes unknown DC number is requested by client.
+# It could be a bug or some global reconfiguration of the Telegram.
+#
+# By default, proxy rejects such requests. But it is also possible to fallback
+# this request to any DC. Telegram works in a way that any DC is able to serve
+# any request but sacrificing a latency.
+#
+# If this setting is disabled (default), mtg will reject a connection.
+# Otherwise, chose a new DC.
+allow-fallback-on-unknown-dc = false
+
+# Telegram uses different DCs for different purposes. Unfortunately, most of
+# DCs are not public, and dependent on a location of the current user, so
+# mtg cannot know upfront about all of them, and how to access them. It has
+# a default list of DCs, including some CDN IPs, but it is possible that some
+# of them are not working for you. In this case, you can override them here.
+[[dc-overrides]]
+dc = 101
+ips = ["127.0.0.1:443"]
+
+# network defines different network-related settings
+[network]
+# please be aware that mtg needs to do some external requests. For
+# example, if you do not pass public ips, it will request your public ip
+# address from some external service.
+#
+# As for 2.0, if you set a public-ip on your own, mtg won't issue any
+# network requests except of those required for Telegram.
+#
+# so, in order of doing them, it needs to do DNS lookup. mtg ignores DNS
+# resolver of the operating system and uses DOH instead. This is a host
+# it has to access.
+#
+# By default we use Cloudflare.
+doh-ip = "1.1.1.1"
+
+# mtg can work via proxies (for now, we support only socks5). Proxy
+# configuration is done via list. So, you can specify many proxies
+# there.
+#
+# Actually, if you supply an empty list, then no proxies are going to be
+# used. If you supply a single proxy, then mtg will use it exclusively.
+# If you supply >= 2, then mtg will load balance between them.
+#
+# If you add an empty string here, this is an equivalent of 'plain network',
+# with no proxy usage.
+#
+# Proxy configuration is done via ordinary URI schema:
+#
+#     socks5://user:password@host:port?open_threshold=5&half_open_timeout=1m&reset_failures_timeout=10s
+#
+# Only socks5 proxy is used. user/password is optional. As you can
+# see, you can specify some parameters in GET query. These parameters
+# configure circuit breaker.
+#
+# open_threshold means a number of errors which should happen so we stop
+# use a proxy.
+#
+# half_open_timeout means a time period (in Golang duration notation)
+# after which we can retry with this proxy
+#
+# reset_failures_timeout means a time period when we flush out errors
+# when circuit breaker in closed state.
+#
+# Please see https://docs.microsoft.com/en-us/azure/architecture/patterns/circuit-breaker
+# on details about circuit breakers.
+proxies = [
+    # "socks5://user:password@host:port?open_threshold=5&half_open_timeout=1m&reset_failures_timeout=10s"
+]
+
+# network timeouts define different settings for timeouts. tcp timeout
+# define a global timeout on establishing of network connections. idle
+# means a timeout on pumping data between sockset when nothing is
+# happening.
+#
+# please be noticed that handshakes have no timeouts intentionally. You can
+# find a reasoning here:
+# https://www.ndss-symposium.org/wp-content/uploads/2020/02/23087-paper.pdf
+[network.timeout]
+tcp = "5s"
+http = "10s"
+idle = "1m"
+
+# Some countries do active probing on Telegram connections. This technique
+# allows to protect from such effort.
+#
+# mtg has a cache of some connection fingerprints. Actually, first bytes
+# of each connection. So, it stores them in some in-memory LRU+TTL cache.
+# You can configure this cache here.
+[defense.anti-replay]
+# You can enable/disable this feature.
+enabled = true
+# max size of such a cache. Please be aware that this number is
+# approximate we try hard to store data quite dense but it is possible
+# that we can go over this limit for 10-20% under some conditions and
+# architectures.
+max-size = "1mib"
+# we use stable bloom filters for anti-replay cache. This helps
+# to maintain a desired error ratio.
+error-rate = 0.001
+
+# You can protect proxies by using different blocklists. If client has
+# ip from the given range, we do not try to do a proper handshake. We
+# actually route it to fronting domain. So, this client will never ever
+# have a chance to use mtg to access Telegram.
+#
+# Please remember that blocklists are initialized in async way. So,
+# when you start a proxy, blocklists are empty, they are populated and
+# processed in backgrounds. An error in any URL is ignored.
+[defense.blocklist]
+# You can enable/disable this feature.
+enabled = true
+# This is a limiter for concurrency. In order to protect website
+# from overloading, we download files in this number of threads.
+download-concurrency = 2
+# A list of URLs in FireHOL format (https://iplists.firehol.org/)
+# You can provider links here (starts with https:// or http://) or
+# path to a local file, but in this case it should be absolute.
+urls = [
+    "https://iplists.firehol.org/files/firehol_level1.netset",
+    # "/local.file"
+]
+# How often do we need to update a blocklist set.
+update-each = "24h"
+
+# Allowlist is an opposite to a blocklist. Only those IPs that are coming from
+# subnets defined in these lists are allowed. All others will be rejected.
+#
+# If this feature is disabled, then there won't be any check performed by this
+# validator. It is possible to combine both blocklist and whitelist.
+[defense.allowlist]
+# You can enable/disable this feature.
+enabled = false
+# This is a limiter for concurrency. In order to protect website
+# from overloading, we download files in this number of threads.
+download-concurrency = 2
+# A list of URLs in FireHOL format (https://iplists.firehol.org/)
+# You can provider links here (starts with https:// or http://) or
+# path to a local file, but in this case it should be absolute.
+urls = [
+    # "https://iplists.firehol.org/files/firehol_level1.netset",
+    # "/local.file"
+
+]
+update-each = "24h"
+
+# statsd statistics integration.
+[stats.statsd]
+# enabled/disabled
+enabled = false
+# host:port for UDP endpoint of statsd
+address = "127.0.0.1:8888"
+# prefix of metric for statsd
+metric-prefix = "mtg"
+# tag format to use
+# supported values are 'datadog', 'influxdb' and 'graphite'
+# default format is graphite.
+tag-format = "datadog"
+
+# prometheus metrics integration.
+[stats.prometheus]
+# enabled/disabled
+enabled = true
+# host:port where to start http server for endpoint
+bind-to = "127.0.0.1:3129"
+# prefix of http path
+http-path = "/"
+# prefix for metrics for prometheus
+metric-prefix = "mtg"

go.mod

@@ -1,26 +1,53 @@
-module github.com/9seconds/mtg
+module github.com/9seconds/mtg/v2
+
+go 1.25
 
 require (
-	github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc // indirect
-	github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf // indirect
-	github.com/beevik/ntp v0.2.0
+	github.com/OneOfOne/xxhash v1.2.8
+	github.com/alecthomas/kong v1.14.0
+	github.com/alecthomas/units v0.0.0-20240927000941-0f3dac36c52b
+	github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5
+	github.com/babolivier/go-doh-client v0.0.0-20201028162107-a76cff4cb8b6
+	github.com/d4l3k/messagediff v1.2.1 // indirect
+	github.com/jarcoal/httpmock v1.0.8
+	github.com/mccutchen/go-httpbin v1.1.1
+	github.com/panjf2000/ants/v2 v2.11.5
+	github.com/prometheus/client_golang v1.23.2
+	github.com/prometheus/common v0.67.5 // indirect
+	github.com/prometheus/procfs v0.19.2 // indirect
+	github.com/rs/zerolog v1.34.0
+	github.com/smira/go-statsd v1.3.4
+	github.com/stretchr/objx v0.5.2 // indirect
+	github.com/stretchr/testify v1.11.1
+	github.com/tylertreat/BoomFilters v0.0.0-20251117164519-53813c36cc1b
+	golang.org/x/crypto v0.48.0
+	golang.org/x/net v0.49.0 // indirect
+	golang.org/x/sys v0.41.0
+	google.golang.org/protobuf v1.36.11 // indirect
+)
+
+require (
+	github.com/pelletier/go-toml/v2 v2.2.4
+	github.com/txthinking/socks5 v0.0.0-20251011041537-5c31f201a10e
+	github.com/yl2chen/cidranger v1.0.2
+)
+
+require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/dustin/go-humanize v0.0.0-20180713052910-9f541cc9db5d
-	github.com/gofrs/uuid v3.1.0+incompatible
-	github.com/juju/errors v0.0.0-20180806074554-22422dad46e1
-	github.com/juju/loggo v0.0.0-20180524022052-584905176618 // indirect
-	github.com/juju/testing v0.0.0-20180920084828-472a3e8b2073 // indirect
-	github.com/kr/pretty v0.1.0 // indirect
-	github.com/pkg/errors v0.8.0 // indirect
+	github.com/klauspost/compress v1.18.3 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/mattn/go-colorable v0.1.14 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/patrickmn/go-cache v2.1.0+incompatible // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/stretchr/testify v1.2.2
-	go.uber.org/atomic v1.3.2 // indirect
-	go.uber.org/multierr v1.1.0 // indirect
-	go.uber.org/zap v1.9.1
-	golang.org/x/net v0.0.0-20180921000356-2f5d2388922f // indirect
-	gopkg.in/alecthomas/kingpin.v2 v2.2.6
-	gopkg.in/alexcesaro/statsd.v2 v2.0.0
-	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
-	gopkg.in/mgo.v2 v2.0.0-20180705113604-9856a29383ce // indirect
-	gopkg.in/yaml.v2 v2.2.1 // indirect
+	github.com/prometheus/client_model v0.6.2 // indirect
+	github.com/rogpeppe/go-internal v1.14.1 // indirect
+	github.com/txthinking/runnergroup v0.0.0-20250224021307-5864ffeb65ae // indirect
+	go.yaml.in/yaml/v2 v2.4.3 // indirect
+	golang.org/x/sync v0.19.0 // indirect
+	golang.org/x/tools v0.41.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,48 +1,156 @@
-github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc h1:cAKDfWh5VpdgMhJosfJnn5/FoN2SRZ4p7fJNX58YPaU=
-github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
-github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf h1:qet1QNfXsQxTZqLG4oE62mJzwPIB8+Tee4RNCL9ulrY=
-github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
-github.com/beevik/ntp v0.2.0 h1:sGsd+kAXzT0bfVfzJfce04g+dSRfrs+tbQW8lweuYgw=
-github.com/beevik/ntp v0.2.0/go.mod h1:hIHWr+l3+/clUnF44zdK+CWW7fO8dR5cIylAQ76NRpg=
+github.com/OneOfOne/xxhash v1.2.8 h1:31czK/TI9sNkxIKfaUfGlU47BAxQ0ztGgd9vPyqimf8=
+github.com/OneOfOne/xxhash v1.2.8/go.mod h1:eZbhyaAYD41SGSSsnmcpxVoRiQ/MPUTjUdIIOT9Um7Q=
+github.com/alecthomas/assert/v2 v2.11.0 h1:2Q9r3ki8+JYXvGsDyBXwH3LcJ+WK5D0gc5E8vS6K3D0=
+github.com/alecthomas/assert/v2 v2.11.0/go.mod h1:Bze95FyfUr7x34QZrjL+XP+0qgp/zg8yS+TtBj1WA3k=
+github.com/alecthomas/kong v1.14.0 h1:gFgEUZWu2ZmZ+UhyZ1bDhuutbKN1nTtJTwh19Wsn21s=
+github.com/alecthomas/kong v1.14.0/go.mod h1:wrlbXem1CWqUV5Vbmss5ISYhsVPkBb1Yo7YKJghju2I=
+github.com/alecthomas/repr v0.5.2 h1:SU73FTI9D1P5UNtvseffFSGmdNci/O6RsqzeXJtP0Qs=
+github.com/alecthomas/repr v0.5.2/go.mod h1:Fr0507jx4eOXV7AlPV6AVZLYrLIuIeSOWtW57eE/O/4=
+github.com/alecthomas/units v0.0.0-20240927000941-0f3dac36c52b h1:mimo19zliBX/vSQ6PWWSL9lK8qwHozUj03+zLoEB8O0=
+github.com/alecthomas/units v0.0.0-20240927000941-0f3dac36c52b/go.mod h1:fvzegU4vN3H1qMT+8wDmzjAcDONcgo2/SZ/TyfdUOFs=
+github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 h1:0CwZNZbxp69SHPdPJAN/hZIm0C4OItdklCFmMRWYpio=
+github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5/go.mod h1:wHh0iHkYZB8zMSxRWpUBQtwG5a7fFgvEO+odwuTv2gs=
+github.com/babolivier/go-doh-client v0.0.0-20201028162107-a76cff4cb8b6 h1:4NNbNM2Iq/k57qEu7WfL67UrbPq1uFWxW4qODCohi+0=
+github.com/babolivier/go-doh-client v0.0.0-20201028162107-a76cff4cb8b6/go.mod h1:J29hk+f9lJrblVIfiJOtTFk+OblBawmib4uz/VdKzlg=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/d4l3k/messagediff v1.2.1 h1:ZcAIMYsUg0EAp9X+tt8/enBE/Q8Yd5kzPynLyKptt9U=
+github.com/d4l3k/messagediff v1.2.1/go.mod h1:Oozbb1TVXFac9FtSIxHBMnBCq2qeH/2KkEQxENCrlLo=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/dustin/go-humanize v0.0.0-20180713052910-9f541cc9db5d h1:lDrio3iIdNb0Gw9CgH7cQF+iuB5mOOjdJ9ERNJCBgb4=
-github.com/dustin/go-humanize v0.0.0-20180713052910-9f541cc9db5d/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
-github.com/gofrs/uuid v3.1.0+incompatible h1:q2rtkjaKT4YEr6E1kamy0Ha4RtepWlQBedyHx0uzKwA=
-github.com/gofrs/uuid v3.1.0+incompatible/go.mod h1:b2aQJv3Z4Fp6yNu3cdSllBxTCLRxnplIgP/c0N/04lM=
-github.com/juju/errors v0.0.0-20180806074554-22422dad46e1 h1:wnhMXidtb70kDZCeLt/EfsVtkXS5c8zLnE9y/6DIRAU=
-github.com/juju/errors v0.0.0-20180806074554-22422dad46e1/go.mod h1:W54LbzXuIE0boCoNJfwqpmkKJ1O4TCTZMetAt6jGk7Q=
-github.com/juju/loggo v0.0.0-20180524022052-584905176618 h1:MK144iBQF9hTSwBW/9eJm034bVoG30IshVm688T2hi8=
-github.com/juju/loggo v0.0.0-20180524022052-584905176618/go.mod h1:vgyd7OREkbtVEN/8IXZe5Ooef3LQePvuBm9UWj6ZL8U=
-github.com/juju/testing v0.0.0-20180920084828-472a3e8b2073 h1:WQM1NildKThwdP7qWrNAFGzp4ijNLw8RlgENkaI4MJs=
-github.com/juju/testing v0.0.0-20180920084828-472a3e8b2073/go.mod h1:63prj8cnj0tU0S9OHjGJn+b1h0ZghCndfnbQolrYTwA=
-github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
-github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
-github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
-github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
-github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
-github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
+github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
+github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
+github.com/jarcoal/httpmock v1.0.8 h1:8kI16SoO6LQKgPE7PvQuV+YuD/inwHd7fOOe2zMbo4k=
+github.com/jarcoal/httpmock v1.0.8/go.mod h1:ATjnClrvW/3tijVmpL/va5Z3aAyGvqU3gCT8nX0Txik=
+github.com/klauspost/compress v1.18.3 h1:9PJRvfbmTabkOX8moIpXPbMMbYN60bWImDDU7L+/6zw=
+github.com/klauspost/compress v1.18.3/go.mod h1:R0h/fSBs8DE4ENlcrlib3PsXS61voFxhIs2DeRhCvJ4=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
+github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
+github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHPsaIE=
+github.com/mattn/go-colorable v0.1.14/go.mod h1:6LmQG8QLFO4G5z1gPvYEzlUgJ2wF+stgPZH1UqBm1s8=
+github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
+github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/mccutchen/go-httpbin v1.1.1 h1:aEws49HEJEyXHLDnshQVswfUlCVoS8g6h9YaDyaW7RE=
+github.com/mccutchen/go-httpbin v1.1.1/go.mod h1:fhpOYavp5g2K74XDl/ao2y4KvhqVtKlkg1e+0UaQv7I=
+github.com/miekg/dns v1.1.51 h1:0+Xg7vObnhrz/4ZCZcZh7zPXlmU0aveS2HDBd0m0qSo=
+github.com/miekg/dns v1.1.51/go.mod h1:2Z9d3CP1LQWihRZUf29mQ19yDThaI4DAYzte2CaQW5c=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
+github.com/panjf2000/ants/v2 v2.11.5 h1:a7LMnMEeux/ebqTux140tRiaqcFTV0q2bEHF03nl6Rg=
+github.com/panjf2000/ants/v2 v2.11.5/go.mod h1:8u92CYMUc6gyvTIw8Ru7Mt7+/ESnJahz5EVtqfrilek=
+github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
+github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
+github.com/pelletier/go-toml/v2 v2.2.4 h1:mye9XuhQ6gvn5h28+VilKrrPoQVanw5PMw/TB0t5Ec4=
+github.com/pelletier/go-toml/v2 v2.2.4/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
-github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
-go.uber.org/atomic v1.3.2 h1:2Oa65PReHzfn29GpvgsYwloV9AVFHPDk8tYxt2c2tr4=
-go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
-go.uber.org/multierr v1.1.0 h1:HoEmRHQPVSqub6w2z2d2EOVs2fjyFRGyofhKuyDq0QI=
-go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
-go.uber.org/zap v1.9.1 h1:XCJQEf3W6eZaVwhRBof6ImoYGJSITeKWsyeh3HFu/5o=
-go.uber.org/zap v1.9.1/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
-golang.org/x/net v0.0.0-20180921000356-2f5d2388922f h1:QM2QVxvDoW9PFSPp/zy9FgxJLfaWTZlS61KEPtBwacM=
-golang.org/x/net v0.0.0-20180921000356-2f5d2388922f/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-gopkg.in/alecthomas/kingpin.v2 v2.2.6 h1:jMFz6MfLP0/4fUyZle81rXUoxOBFi19VUFKVDOQfozc=
-gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
-gopkg.in/alexcesaro/statsd.v2 v2.0.0 h1:FXkZSCZIH17vLCO5sO2UucTHsH9pc+17F6pl3JVCwMc=
-gopkg.in/alexcesaro/statsd.v2 v2.0.0/go.mod h1:i0ubccKGzBVNBpdGV5MocxyA/XlLUJzA7SLonnE4drU=
+github.com/prometheus/client_golang v1.23.2 h1:Je96obch5RDVy3FDMndoUsjAhG5Edi49h0RJWRi/o0o=
+github.com/prometheus/client_golang v1.23.2/go.mod h1:Tb1a6LWHB3/SPIzCoaDXI4I8UHKeFTEQ1YCr+0Gyqmg=
+github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
+github.com/prometheus/client_model v0.6.2/go.mod h1:y3m2F6Gdpfy6Ut/GBsUqTWZqCUvMVzSfMLjcu6wAwpE=
+github.com/prometheus/common v0.67.5 h1:pIgK94WWlQt1WLwAC5j2ynLaBRDiinoAb86HZHTUGI4=
+github.com/prometheus/common v0.67.5/go.mod h1:SjE/0MzDEEAyrdr5Gqc6G+sXI67maCxzaT3A2+HqjUw=
+github.com/prometheus/procfs v0.19.2 h1:zUMhqEW66Ex7OXIiDkll3tl9a1ZdilUOd/F6ZXw4Vws=
+github.com/prometheus/procfs v0.19.2/go.mod h1:M0aotyiemPhBCM0z5w87kL22CxfcH05ZpYlu+b4J7mw=
+github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
+github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
+github.com/rs/xid v1.6.0/go.mod h1:7XoLgs4eV+QndskICGsho+ADou8ySMSjJKDIan90Nz0=
+github.com/rs/zerolog v1.34.0 h1:k43nTLIwcTVQAncfCw4KZ2VY6ukYoZaBPNOE8txlOeY=
+github.com/rs/zerolog v1.34.0/go.mod h1:bJsvje4Z08ROH4Nhs5iH600c3IkWhwp44iRc54W6wYQ=
+github.com/smira/go-statsd v1.3.4 h1:kBYWcLSGT+qC6JVbvfz48kX7mQys32fjDOPrfmsSx2c=
+github.com/smira/go-statsd v1.3.4/go.mod h1:RjdsESPgDODtg1VpVVf9MJrEW2Hw0wtRNbmB1CAhu6A=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/objx v0.5.2 h1:xuMeJ0Sdp5ZMRXx/aWO6RZxdr3beISkG5/G/aIRr3pY=
+github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+github.com/txthinking/runnergroup v0.0.0-20210608031112-152c7c4432bf/go.mod h1:CLUSJbazqETbaR+i0YAhXBICV9TrKH93pziccMhmhpM=
+github.com/txthinking/runnergroup v0.0.0-20250224021307-5864ffeb65ae h1:ArVM1jICfm7g4E4dBet+KHUFMLuxmj1Nxdp/tr3ByCU=
+github.com/txthinking/runnergroup v0.0.0-20250224021307-5864ffeb65ae/go.mod h1:cldYm15/XHcGt7ndItnEWHwFZo7dinU+2QoyjfErhsI=
+github.com/txthinking/socks5 v0.0.0-20251011041537-5c31f201a10e h1:xA7GVlbz6teIF4FdvuqwbX6C4tiqNk2PH7FRPIDerao=
+github.com/txthinking/socks5 v0.0.0-20251011041537-5c31f201a10e/go.mod h1:ntmMHL/xPq1WLeKiw8p/eRATaae6PiVRNipHFJxI8PM=
+github.com/tylertreat/BoomFilters v0.0.0-20251117164519-53813c36cc1b h1:p+bJ3v5uUdEVMCoeFUs+BNJPsqt+Y6BLbDaPfTcbcH8=
+github.com/tylertreat/BoomFilters v0.0.0-20251117164519-53813c36cc1b/go.mod h1:OYRfF6eb5wY9VRFkXJH8FFBi3plw2v+giaIu7P054pM=
+github.com/yl2chen/cidranger v1.0.2 h1:lbOWZVCG1tCRX4u24kuM1Tb4nHqWkDxwLdoS+SevawU=
+github.com/yl2chen/cidranger v1.0.2/go.mod h1:9U1yz7WPYDwf0vpNWFaeRh0bjwz5RVgRy/9UEQfHl0g=
+github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
+go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
+go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
+go.yaml.in/yaml/v2 v2.4.3 h1:6gvOSjQoTB3vt1l+CU+tSyi/HOjfOjRLJ4YwYZGwRO0=
+go.yaml.in/yaml/v2 v2.4.3/go.mod h1:zSxWcmIDjOzPXpjlTTbAsKokqkDNAVtZO0WOMiT90s8=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
+golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=
+golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/mod v0.7.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/mod v0.32.0 h1:9F4d3PHLljb6x//jOyokMv3eX+YDeepZSEo3mFJy93c=
+golang.org/x/mod v0.32.0/go.mod h1:SgipZ/3h2Ci89DlEtEXWUk/HteuRin+HHhN+WbNhguU=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
+golang.org/x/net v0.2.0/go.mod h1:KqCZLdyyvdV855qA2rE3GC2aiw5xGR5TEjj8smXukLY=
+golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
+golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
+golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
+golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
+golang.org/x/term v0.2.0/go.mod h1:TVmDHMZPmdnySmBfhjOoOdhjzdE1h4u1VwSiw2l1Nuc=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/text v0.4.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
+golang.org/x/tools v0.3.0/go.mod h1:/rWhSS2+zyEVwoJf8YAX6L2f0ntZ7Kn/mGgAWcipA5k=
+golang.org/x/tools v0.41.0 h1:a9b8iMweWG+S0OBnlU36rzLp20z1Rp10w+IY2czHTQc=
+golang.org/x/tools v0.41.0/go.mod h1:XSY6eDqxVNiYgezAVqqCeihT4j1U2CCsqvH3WhQpnlg=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
+google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
-gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/mgo.v2 v2.0.0-20180705113604-9856a29383ce h1:xcEWjVhvbDy+nHP67nPDDpbYrY+ILlfndk4bRioVHaU=
-gopkg.in/mgo.v2 v2.0.0-20180705113604-9856a29383ce/go.mod h1:yeKp02qBN3iKW1OzL3MGk2IdtZzaj7SFntXj72NppTA=
-gopkg.in/yaml.v2 v2.2.1 h1:mUhvW9EsL+naU5Q3cakzfE91YhliOondGd6ZrsDBHQE=
-gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/cli/access.go

@@ -0,0 +1,184 @@
+package cli
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/9seconds/mtg/v2/essentials"
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/9seconds/mtg/v2/internal/utils"
+	"github.com/9seconds/mtg/v2/mtglib"
+)
+
+type accessResponse struct {
+	IPv4   *accessResponseURLs `json:"ipv4,omitempty"`
+	IPv6   *accessResponseURLs `json:"ipv6,omitempty"`
+	Secret struct {
+		Hex    string `json:"hex"`
+		Base64 string `json:"base64"`
+	} `json:"secret"`
+}
+
+type accessResponseURLs struct {
+	IP        net.IP `json:"ip"`
+	Port      uint   `json:"port"`
+	TgURL     string `json:"tg_url"`     //nolint: tagliatelle
+	TgQrCode  string `json:"tg_qrcode"`  //nolint: tagliatelle
+	TmeURL    string `json:"tme_url"`    //nolint: tagliatelle
+	TmeQrCode string `json:"tme_qrcode"` //nolint: tagliatelle
+}
+
+type Access struct {
+	ConfigPath string `kong:"arg,required,type='existingfile',help='Path to the configuration file.',name='config-path'"`                 //nolint: lll
+	PublicIPv4 net.IP `kong:"help='Public IPv4 address for proxy. By default it is resolved via remote website',name='ipv4',short='i'"`   //nolint: lll
+	PublicIPv6 net.IP `kong:"help='Public IPv6 address for proxy. By default it is resolved via remote website',name='ipv6',short='I'"`   //nolint: lll
+	Port       uint   `kong:"help='Port number. Default port is taken from configuration file, bind-to parameter',type:'uint',short='p'"` //nolint: lll
+	Hex        bool   `kong:"help='Print secret in hex encoding.',short='x'"`
+}
+
+func (a *Access) Run(cli *CLI, version string) error {
+	conf, err := utils.ReadConfig(a.ConfigPath)
+	if err != nil {
+		return fmt.Errorf("cannot init config: %w", err)
+	}
+
+	resp := &accessResponse{}
+	resp.Secret.Base64 = conf.Secret.Base64()
+	resp.Secret.Hex = conf.Secret.Hex()
+
+	ntw, err := makeNetwork(conf, version)
+	if err != nil {
+		return fmt.Errorf("cannot init network: %w", err)
+	}
+
+	wg := &sync.WaitGroup{}
+	wg.Add(2)
+
+	go func() {
+		defer wg.Done()
+
+		ip := a.PublicIPv4
+		if ip == nil {
+			ip = a.getIP(ntw, "tcp4")
+		}
+
+		if ip != nil {
+			ip = ip.To4()
+		}
+
+		resp.IPv4 = a.makeURLs(conf, ip)
+	}()
+
+	go func() {
+		defer wg.Done()
+
+		ip := a.PublicIPv6
+		if ip == nil {
+			ip = a.getIP(ntw, "tcp6")
+		}
+
+		if ip != nil {
+			ip = ip.To16()
+		}
+
+		resp.IPv6 = a.makeURLs(conf, ip)
+	}()
+
+	wg.Wait()
+
+	encoder := json.NewEncoder(os.Stdout)
+	encoder.SetEscapeHTML(false)
+	encoder.SetIndent("", "  ")
+
+	if err := encoder.Encode(resp); err != nil {
+		return fmt.Errorf("cannot dump access json: %w", err)
+	}
+
+	return nil
+}
+
+func (a *Access) getIP(ntw mtglib.Network, protocol string) net.IP {
+	client := ntw.MakeHTTPClient(func(ctx context.Context, network, address string) (essentials.Conn, error) {
+		return ntw.DialContext(ctx, protocol, address) //nolint: wrapcheck
+	})
+
+	req, err := http.NewRequest(http.MethodGet, "https://ifconfig.co", nil) //nolint: noctx
+	if err != nil {
+		panic(err)
+	}
+
+	req.Header.Add("Accept", "text/plain")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil
+	}
+
+	defer func() {
+		io.Copy(io.Discard, resp.Body) //nolint: errcheck
+		resp.Body.Close()              //nolint: errcheck
+	}()
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil
+	}
+
+	return net.ParseIP(strings.TrimSpace(string(data)))
+}
+
+func (a *Access) makeURLs(conf *config.Config, ip net.IP) *accessResponseURLs {
+	if ip == nil {
+		return nil
+	}
+
+	portNo := a.Port
+	if portNo == 0 {
+		portNo = conf.BindTo.Port
+	}
+
+	values := url.Values{}
+	values.Set("server", ip.String())
+	values.Set("port", strconv.Itoa(int(portNo)))
+
+	if a.Hex {
+		values.Set("secret", conf.Secret.Hex())
+	} else {
+		values.Set("secret", conf.Secret.Base64())
+	}
+
+	urlQuery := values.Encode()
+
+	rv := &accessResponseURLs{
+		IP:   ip,
+		Port: portNo,
+		TgURL: (&url.URL{
+			Scheme:   "tg",
+			Host:     "proxy",
+			RawQuery: urlQuery,
+		}).String(),
+		TmeURL: (&url.URL{
+			Scheme:   "https",
+			Host:     "t.me",
+			Path:     "proxy",
+			RawQuery: urlQuery,
+		}).String(),
+	}
+	rv.TgQrCode = utils.MakeQRCodeURL(rv.TgURL)
+	rv.TmeQrCode = utils.MakeQRCodeURL(rv.TmeURL)
+
+	return rv
+}

internal/cli/cli.go

@@ -0,0 +1,11 @@
+package cli
+
+import "github.com/alecthomas/kong"
+
+type CLI struct {
+	GenerateSecret GenerateSecret   `kong:"cmd,help='Generate new proxy secret'"`
+	Access         Access           `kong:"cmd,help='Print access information.'"`
+	Run            Run              `kong:"cmd,help='Run proxy.'"`
+	SimpleRun      SimpleRun        `kong:"cmd,help='Run proxy without config file.'"`
+	Version        kong.VersionFlag `kong:"help='Print version.',short='v'"`
+}

internal/cli/generate_secret.go

@@ -0,0 +1,24 @@
+package cli
+
+import (
+	"fmt"
+
+	"github.com/9seconds/mtg/v2/mtglib"
+)
+
+type GenerateSecret struct {
+	HostName string `kong:"arg,required,help='Hostname to use for domain fronting.',name='hostname'"`
+	Hex      bool   `kong:"help='Print secret in hex encoding.',short='x'"`
+}
+
+func (g *GenerateSecret) Run(cli *CLI, _ string) error {
+	secret := mtglib.GenerateSecret(cli.GenerateSecret.HostName)
+
+	if g.Hex {
+		fmt.Println(secret.Hex()) //nolint: forbidigo
+	} else {
+		fmt.Println(secret.Base64()) //nolint: forbidigo
+	}
+
+	return nil
+}

internal/cli/run.go

@@ -0,0 +1,20 @@
+package cli
+
+import (
+	"fmt"
+
+	"github.com/9seconds/mtg/v2/internal/utils"
+)
+
+type Run struct {
+	ConfigPath string `kong:"arg,required,type='existingfile',help='Path to the configuration file.',name='config-path'"` //nolint: lll
+}
+
+func (r *Run) Run(cli *CLI, version string) error {
+	conf, err := utils.ReadConfig(r.ConfigPath)
+	if err != nil {
+		return fmt.Errorf("cannot init config: %w", err)
+	}
+
+	return runProxy(conf, version)
+}

internal/cli/run_proxy.go

@@ -0,0 +1,287 @@
+package cli
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/url"
+	"os"
+
+	"github.com/9seconds/mtg/v2/antireplay"
+	"github.com/9seconds/mtg/v2/events"
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/9seconds/mtg/v2/internal/utils"
+	"github.com/9seconds/mtg/v2/ipblocklist"
+	"github.com/9seconds/mtg/v2/ipblocklist/files"
+	"github.com/9seconds/mtg/v2/logger"
+	"github.com/9seconds/mtg/v2/mtglib"
+	"github.com/9seconds/mtg/v2/network"
+	"github.com/9seconds/mtg/v2/stats"
+	"github.com/rs/zerolog"
+	"github.com/yl2chen/cidranger"
+)
+
+func makeLogger(conf *config.Config) mtglib.Logger {
+	zerolog.TimeFieldFormat = zerolog.TimeFormatUnixMs
+	zerolog.TimestampFieldName = "timestamp"
+	zerolog.LevelFieldName = "level"
+
+	if conf.Debug.Get(false) {
+		zerolog.SetGlobalLevel(zerolog.DebugLevel)
+	} else {
+		zerolog.SetGlobalLevel(zerolog.WarnLevel)
+	}
+
+	baseLogger := zerolog.New(os.Stdout).With().Timestamp().Logger()
+
+	return logger.NewZeroLogger(baseLogger)
+}
+
+func makeNetwork(conf *config.Config, version string) (mtglib.Network, error) {
+	tcpTimeout := conf.Network.Timeout.TCP.Get(network.DefaultTimeout)
+	httpTimeout := conf.Network.Timeout.HTTP.Get(network.DefaultHTTPTimeout)
+	dohIP := conf.Network.DOHIP.Get(net.ParseIP(network.DefaultDOHHostname)).String()
+	userAgent := "mtg/" + version
+
+	baseDialer, err := network.NewDefaultDialer(tcpTimeout, 0)
+	if err != nil {
+		return nil, fmt.Errorf("cannot build a default dialer: %w", err)
+	}
+
+	if len(conf.Network.Proxies) == 0 {
+		return network.NewNetwork(baseDialer, userAgent, dohIP, httpTimeout) //nolint: wrapcheck
+	}
+
+	proxyURLs := make([]*url.URL, 0, len(conf.Network.Proxies))
+
+	for _, v := range conf.Network.Proxies {
+		if value := v.Get(nil); value != nil {
+			proxyURLs = append(proxyURLs, value)
+		}
+	}
+
+	if len(proxyURLs) == 1 {
+		socksDialer, err := network.NewSocks5Dialer(baseDialer, proxyURLs[0])
+		if err != nil {
+			return nil, fmt.Errorf("cannot build socks5 dialer: %w", err)
+		}
+
+		return network.NewNetwork(socksDialer, userAgent, dohIP, httpTimeout) //nolint: wrapcheck
+	}
+
+	socksDialer, err := network.NewLoadBalancedSocks5Dialer(baseDialer, proxyURLs)
+	if err != nil {
+		return nil, fmt.Errorf("cannot build socks5 dialer: %w", err)
+	}
+
+	return network.NewNetwork(socksDialer, userAgent, dohIP, httpTimeout) //nolint: wrapcheck
+}
+
+func makeAntiReplayCache(conf *config.Config) mtglib.AntiReplayCache {
+	if !conf.Defense.AntiReplay.Enabled.Get(false) {
+		return antireplay.NewNoop()
+	}
+
+	return antireplay.NewStableBloomFilter(
+		conf.Defense.AntiReplay.MaxSize.Get(antireplay.DefaultStableBloomFilterMaxSize),
+		conf.Defense.AntiReplay.ErrorRate.Get(antireplay.DefaultStableBloomFilterErrorRate),
+	)
+}
+
+func makeIPBlocklist(conf config.ListConfig,
+	logger mtglib.Logger,
+	ntw mtglib.Network,
+	updateCallback ipblocklist.FireholUpdateCallback,
+) (mtglib.IPBlocklist, error) {
+	if !conf.Enabled.Get(false) {
+		return ipblocklist.NewNoop(), nil
+	}
+
+	remoteURLs := []string{}
+	localFiles := []string{}
+
+	for _, v := range conf.URLs {
+		if v.IsRemote() {
+			remoteURLs = append(remoteURLs, v.String())
+		} else {
+			localFiles = append(localFiles, v.String())
+		}
+	}
+
+	blocklist, err := ipblocklist.NewFirehol(logger.Named("ipblockist"),
+		ntw,
+		conf.DownloadConcurrency.Get(1),
+		remoteURLs,
+		localFiles,
+		updateCallback)
+	if err != nil {
+		return nil, fmt.Errorf("incorrect parameters for firehol: %w", err)
+	}
+
+	go blocklist.Run(conf.UpdateEach.Get(ipblocklist.DefaultFireholUpdateEach))
+
+	return blocklist, nil
+}
+
+func makeIPAllowlist(conf config.ListConfig,
+	logger mtglib.Logger,
+	ntw mtglib.Network,
+	updateCallback ipblocklist.FireholUpdateCallback,
+) (mtglib.IPBlocklist, error) {
+	var (
+		allowlist mtglib.IPBlocklist
+		err       error
+	)
+
+	if !conf.Enabled.Get(false) {
+		allowlist, err = ipblocklist.NewFireholFromFiles(
+			logger.Named("ipblocklist"),
+			1,
+			[]files.File{
+				files.NewMem([]*net.IPNet{
+					cidranger.AllIPv4,
+					cidranger.AllIPv6,
+				}),
+			},
+			updateCallback,
+		)
+
+		go allowlist.Run(conf.UpdateEach.Get(ipblocklist.DefaultFireholUpdateEach))
+	} else {
+		allowlist, err = makeIPBlocklist(
+			conf,
+			logger,
+			ntw,
+			updateCallback,
+		)
+	}
+
+	if err != nil {
+		return nil, fmt.Errorf("cannot build allowlist: %w", err)
+	}
+
+	return allowlist, nil
+}
+
+func makeEventStream(conf *config.Config, logger mtglib.Logger) (mtglib.EventStream, error) {
+	factories := make([]events.ObserverFactory, 0, 2)
+
+	if conf.Stats.StatsD.Enabled.Get(false) {
+		statsdFactory, err := stats.NewStatsd(
+			conf.Stats.StatsD.Address.Get(""),
+			logger.Named("statsd"),
+			conf.Stats.StatsD.MetricPrefix.Get(stats.DefaultStatsdMetricPrefix),
+			conf.Stats.StatsD.TagFormat.Get(stats.DefaultStatsdTagFormat))
+		if err != nil {
+			return nil, fmt.Errorf("cannot build statsd observer: %w", err)
+		}
+
+		factories = append(factories, statsdFactory.Make)
+	}
+
+	if conf.Stats.Prometheus.Enabled.Get(false) {
+		prometheus := stats.NewPrometheus(
+			conf.Stats.Prometheus.MetricPrefix.Get(stats.DefaultMetricPrefix),
+			conf.Stats.Prometheus.HTTPPath.Get("/"),
+		)
+
+		listener, err := net.Listen("tcp", conf.Stats.Prometheus.BindTo.Get(""))
+		if err != nil {
+			return nil, fmt.Errorf("cannot start a listener for prometheus: %w", err)
+		}
+
+		go prometheus.Serve(listener) //nolint: errcheck
+
+		factories = append(factories, prometheus.Make)
+	}
+
+	if len(factories) > 0 {
+		return events.NewEventStream(factories), nil
+	}
+
+	return events.NewNoopStream(), nil
+}
+
+func runProxy(conf *config.Config, version string) error { //nolint: funlen
+	logger := makeLogger(conf)
+
+	logger.BindJSON("configuration", conf.String()).Debug("configuration")
+
+	eventStream, err := makeEventStream(conf, logger)
+	if err != nil {
+		return fmt.Errorf("cannot build event stream: %w", err)
+	}
+
+	ntw, err := makeNetwork(conf, version)
+	if err != nil {
+		return fmt.Errorf("cannot build network: %w", err)
+	}
+
+	blocklist, err := makeIPBlocklist(
+		conf.Defense.Blocklist,
+		logger.Named("blocklist"),
+		ntw,
+		func(ctx context.Context, size int) {
+			eventStream.Send(ctx, mtglib.NewEventIPListSize(size, true))
+		})
+	if err != nil {
+		return fmt.Errorf("cannot build ip blocklist: %w", err)
+	}
+
+	allowlist, err := makeIPAllowlist(
+		conf.Defense.Allowlist,
+		logger.Named("allowlist"),
+		ntw,
+		func(ctx context.Context, size int) {
+			eventStream.Send(ctx, mtglib.NewEventIPListSize(size, false))
+		},
+	)
+	if err != nil {
+		return fmt.Errorf("cannot build ip allowlist: %w", err)
+	}
+
+	dcOverrides := map[int][]string{}
+	for _, override := range conf.DCOverrides {
+		dcid := override.DC.Get()
+		for _, addr := range override.IPs {
+			dcOverrides[dcid] = append(dcOverrides[dcid], addr.Get(""))
+		}
+	}
+
+	opts := mtglib.ProxyOpts{
+		Logger:          logger,
+		Network:         ntw,
+		AntiReplayCache: makeAntiReplayCache(conf),
+		IPBlocklist:     blocklist,
+		IPAllowlist:     allowlist,
+		EventStream:     eventStream,
+
+		Secret:             conf.Secret,
+		DomainFrontingPort: conf.DomainFrontingPort.Get(mtglib.DefaultDomainFrontingPort),
+		PreferIP:           conf.PreferIP.Get(mtglib.DefaultPreferIP),
+
+		AllowFallbackOnUnknownDC: conf.AllowFallbackOnUnknownDC.Get(false),
+		TolerateTimeSkewness:     conf.TolerateTimeSkewness.Value,
+		DCOverrides:              dcOverrides,
+	}
+
+	proxy, err := mtglib.NewProxy(opts)
+	if err != nil {
+		return fmt.Errorf("cannot create a proxy: %w", err)
+	}
+
+	listener, err := utils.NewListener(conf.BindTo.Get(""), 0)
+	if err != nil {
+		return fmt.Errorf("cannot start proxy: %w", err)
+	}
+
+	ctx := utils.RootContext()
+
+	go proxy.Serve(listener) //nolint: errcheck
+
+	<-ctx.Done()
+	listener.Close() //nolint: errcheck
+	proxy.Shutdown()
+
+	return nil
+}

internal/cli/simple_run.go

@@ -0,0 +1,89 @@
+package cli
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+	"time"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+)
+
+type SimpleRun struct {
+	BindTo string `kong:"arg,required,name='bind-to',help='A host:port to bind proxy to.'"`
+	Secret string `kong:"arg,required,name='secret',help='Proxy secret.'"`
+
+	Debug               bool          `kong:"name='debug',short='d',help='Run in debug mode.'"`                                                                        //nolint: lll
+	Concurrency         uint64        `kong:"name='concurrency',short='c',default='8192',help='Max number of concurrent connection to proxy.'"`                        //nolint: lll
+	TCPBuffer           string        `kong:"name='tcp-buffer',short='b',default='4KB',help='Deprecated and ignored'"`                                                 //nolint: lll
+	PreferIP            string        `kong:"name='prefer-ip',short='i',default='prefer-ipv6',help='IP preference. By default we prefer IPv6 with fallback to IPv4.'"` //nolint: lll
+	DomainFrontingPort  uint64        `kong:"name='domain-fronting-port',short='p',default='443',help='A port to access for domain fronting.'"`                        //nolint: lll
+	DOHIP               net.IP        `kong:"name='doh-ip',short='n',default='1.1.1.1',help='IP address of DNS-over-HTTP to use.'"`                                    //nolint: lll
+	Timeout             time.Duration `kong:"name='timeout',short='t',default='10s',help='Network timeout to use'"`                                                    //nolint: lll
+	Socks5Proxies       []string      `kong:"name='socks5-proxy',short='s',help='Socks5 proxies to use for network access.'"`                                          //nolint: lll
+	AntiReplayCacheSize string        `kong:"name='antireplay-cache-size',short='a',default='1MB',help='A size of anti-replay cache to use.'"`                         //nolint: lll
+}
+
+func (s *SimpleRun) Run(cli *CLI, version string) error { //nolint: cyclop,funlen
+	conf := &config.Config{}
+
+	if err := conf.BindTo.Set(s.BindTo); err != nil {
+		return fmt.Errorf("incorrect bind-to parameter: %w", err)
+	}
+
+	if err := conf.Secret.Set(s.Secret); err != nil {
+		return fmt.Errorf("incorrect secret: %w", err)
+	}
+
+	if err := conf.Concurrency.Set(strconv.FormatUint(s.Concurrency, 10)); err != nil {
+		return fmt.Errorf("incorrect concurrency: %w", err)
+	}
+
+	if err := conf.PreferIP.Set(s.PreferIP); err != nil {
+		return fmt.Errorf("incorrect prefer-ip: %w", err)
+	}
+
+	if err := conf.DomainFrontingPort.Set(strconv.FormatUint(s.DomainFrontingPort, 10)); err != nil {
+		return fmt.Errorf("incorrect domain-fronting-port: %w", err)
+	}
+
+	if err := conf.Network.DOHIP.Set(s.DOHIP.String()); err != nil {
+		return fmt.Errorf("incorrect doh-ip: %w", err)
+	}
+
+	if err := conf.Network.Timeout.TCP.Set(s.Timeout.String()); err != nil {
+		return fmt.Errorf("incorrect timeout: %w", err)
+	}
+
+	if err := conf.Network.Timeout.HTTP.Set(s.Timeout.String()); err != nil {
+		return fmt.Errorf("incorrect timeout: %w", err)
+	}
+
+	if err := conf.Network.Timeout.Idle.Set(s.Timeout.String()); err != nil {
+		return fmt.Errorf("incorrect timeout: %w", err)
+	}
+
+	if err := conf.Defense.AntiReplay.MaxSize.Set(s.AntiReplayCacheSize); err != nil {
+		return fmt.Errorf("incorrect antireplay-cache-size: %w", err)
+	}
+
+	for _, v := range s.Socks5Proxies {
+		proxyURL := config.TypeProxyURL{}
+
+		if err := proxyURL.Set(v); err != nil {
+			return fmt.Errorf("incorrect socks5 proxy URL: %w", err)
+		}
+
+		conf.Network.Proxies = append(conf.Network.Proxies, proxyURL)
+	}
+
+	conf.Debug.Value = s.Debug
+	conf.AllowFallbackOnUnknownDC.Value = true
+	conf.Defense.AntiReplay.Enabled.Value = true
+
+	if err := conf.Validate(); err != nil {
+		return fmt.Errorf("invalid result configuration: %w", err)
+	}
+
+	return runProxy(conf, version)
+}

internal/config/config.go

@@ -0,0 +1,96 @@
+package config
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+
+	"github.com/9seconds/mtg/v2/mtglib"
+)
+
+type Optional struct {
+	Enabled TypeBool `json:"enabled"`
+}
+
+type ListConfig struct {
+	Optional
+
+	DownloadConcurrency TypeConcurrency    `json:"downloadConcurrency"`
+	URLs                []TypeBlocklistURI `json:"urls"`
+	UpdateEach          TypeDuration       `json:"updateEach"`
+}
+
+type Config struct {
+	Debug                    TypeBool        `json:"debug"`
+	AllowFallbackOnUnknownDC TypeBool        `json:"allowFallbackOnUnknownDc"`
+	Secret                   mtglib.Secret   `json:"secret"`
+	BindTo                   TypeHostPort    `json:"bindTo"`
+	PreferIP                 TypePreferIP    `json:"preferIp"`
+	DomainFrontingPort       TypePort        `json:"domainFrontingPort"`
+	TolerateTimeSkewness     TypeDuration    `json:"tolerateTimeSkewness"`
+	Concurrency              TypeConcurrency `json:"concurrency"`
+	Defense                  struct {
+		AntiReplay struct {
+			Optional
+
+			MaxSize   TypeBytes     `json:"maxSize"`
+			ErrorRate TypeErrorRate `json:"errorRate"`
+		} `json:"antiReplay"`
+		Blocklist ListConfig `json:"blocklist"`
+		Allowlist ListConfig `json:"allowlist"`
+	} `json:"defense"`
+	Network struct {
+		Timeout struct {
+			TCP  TypeDuration `json:"tcp"`
+			HTTP TypeDuration `json:"http"`
+			Idle TypeDuration `json:"idle"`
+		} `json:"timeout"`
+		DOHIP   TypeIP         `json:"dohIp"`
+		Proxies []TypeProxyURL `json:"proxies"`
+	} `json:"network"`
+	Stats struct {
+		StatsD struct {
+			Optional
+
+			Address      TypeHostPort        `json:"address"`
+			MetricPrefix TypeMetricPrefix    `json:"metricPrefix"`
+			TagFormat    TypeStatsdTagFormat `json:"tagFormat"`
+		} `json:"statsd"`
+		Prometheus struct {
+			Optional
+
+			BindTo       TypeHostPort     `json:"bindTo"`
+			HTTPPath     TypeHTTPPath     `json:"httpPath"`
+			MetricPrefix TypeMetricPrefix `json:"metricPrefix"`
+		} `json:"prometheus"`
+	} `json:"stats"`
+	DCOverrides []struct {
+		DC  TypeDC         `json:"dc"`
+		IPs []TypeHostPort `json:"ips"`
+	} `json:"dcOverrides"`
+}
+
+func (c *Config) Validate() error {
+	if !c.Secret.Valid() {
+		return fmt.Errorf("invalid secret %s", c.Secret.String())
+	}
+
+	if c.BindTo.Get("") == "" {
+		return fmt.Errorf("incorrect bind-to parameter %s", c.BindTo.String())
+	}
+
+	return nil
+}
+
+func (c *Config) String() string {
+	buf := &bytes.Buffer{}
+	encoder := json.NewEncoder(buf)
+
+	encoder.SetEscapeHTML(false)
+
+	if err := encoder.Encode(c); err != nil {
+		panic(err)
+	}
+
+	return buf.String()
+}

internal/config/config_test.go

@@ -0,0 +1,54 @@
+package config_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/suite"
+)
+
+type ConfigTestSuite struct {
+	suite.Suite
+}
+
+func (suite *ConfigTestSuite) ReadConfig(filename string) []byte {
+	data, err := os.ReadFile(filepath.Join("testdata", filename))
+	suite.NoError(err)
+
+	return data
+}
+
+func (suite *ConfigTestSuite) TestParseEmpty() {
+	_, err := config.Parse([]byte{})
+	suite.Error(err)
+}
+
+func (suite *ConfigTestSuite) TestParseBrokenToml() {
+	_, err := config.Parse(suite.ReadConfig("broken.toml"))
+	suite.Error(err)
+}
+
+func (suite *ConfigTestSuite) TestParseOnlySecret() {
+	_, err := config.Parse(suite.ReadConfig("only_secret.toml"))
+	suite.Error(err)
+}
+
+func (suite *ConfigTestSuite) TestParseMinimalConfig() {
+	conf, err := config.Parse(suite.ReadConfig("minimal.toml"))
+	suite.NoError(err)
+	suite.Equal("7oe1GqLy6TBc38CV3jx7q09nb29nbGUuY29t", conf.Secret.Base64())
+	suite.Equal("0.0.0.0:3128", conf.BindTo.String())
+}
+
+func (suite *ConfigTestSuite) TestString() {
+	conf, err := config.Parse(suite.ReadConfig("minimal.toml"))
+	suite.NoError(err)
+	suite.NotEmpty(conf.String())
+}
+
+func TestConfig(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &ConfigTestSuite{})
+}

internal/config/parse.go

@@ -0,0 +1,90 @@
+package config
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+
+	"github.com/pelletier/go-toml/v2"
+)
+
+type tomlConfig struct {
+	Debug                    bool   `toml:"debug" json:"debug,omitempty"`
+	AllowFallbackOnUnknownDC bool   `toml:"allow-fallback-on-unknown-dc" json:"allowFallbackOnUnknownDc,omitempty"`
+	Secret                   string `toml:"secret" json:"secret"`
+	BindTo                   string `toml:"bind-to" json:"bindTo"`
+	PreferIP                 string `toml:"prefer-ip" json:"preferIp,omitempty"`
+	DomainFrontingPort       uint   `toml:"domain-fronting-port" json:"domainFrontingPort,omitempty"`
+	TolerateTimeSkewness     string `toml:"tolerate-time-skewness" json:"tolerateTimeSkewness,omitempty"`
+	Concurrency              uint   `toml:"concurrency" json:"concurrency,omitempty"`
+	Defense                  struct {
+		AntiReplay struct {
+			Enabled   bool    `toml:"enabled" json:"enabled,omitempty"`
+			MaxSize   string  `toml:"max-size" json:"maxSize,omitempty"`
+			ErrorRate float64 `toml:"error-rate" json:"errorRate,omitempty"`
+		} `toml:"anti-replay" json:"antiReplay,omitempty"`
+		Blocklist struct {
+			Enabled             bool     `toml:"enabled" json:"enabled,omitempty"`
+			DownloadConcurrency uint     `toml:"download-concurrency" json:"downloadConcurrency,omitempty"`
+			URLs                []string `toml:"urls" json:"urls,omitempty"`
+			UpdateEach          string   `toml:"update-each" json:"updateEach,omitempty"`
+		} `toml:"blocklist" json:"blocklist,omitempty"`
+		Allowlist struct {
+			Enabled             bool     `toml:"enabled" json:"enabled,omitempty"`
+			DownloadConcurrency uint     `toml:"download-concurrency" json:"downloadConcurrency,omitempty"`
+			URLs                []string `toml:"urls" json:"urls,omitempty"`
+			UpdateEach          string   `toml:"update-each" json:"updateEach,omitempty"`
+		} `toml:"allowlist" json:"allowlist,omitempty"`
+	} `toml:"defense" json:"defense,omitempty"`
+	Network struct {
+		Timeout struct {
+			TCP  string `toml:"tcp" json:"tcp,omitempty"`
+			HTTP string `toml:"http" json:"http,omitempty"`
+			Idle string `toml:"idle" json:"idle,omitempty"`
+		} `toml:"timeout" json:"timeout,omitempty"`
+		DOHIP   string   `toml:"doh-ip" json:"dohIp,omitempty"`
+		Proxies []string `toml:"proxies" json:"proxies,omitempty"`
+	} `toml:"network" json:"network,omitempty"`
+	Stats struct {
+		StatsD struct {
+			Enabled      bool   `toml:"enabled" json:"enabled,omitempty"`
+			Address      string `toml:"address" json:"address,omitempty"`
+			MetricPrefix string `toml:"metric-prefix" json:"metricPrefix,omitempty"`
+			TagFormat    string `toml:"tag-format" json:"tagFormat,omitempty"`
+		} `toml:"statsd" json:"statsd,omitempty"`
+		Prometheus struct {
+			Enabled      bool   `toml:"enabled" json:"enabled,omitempty"`
+			BindTo       string `toml:"bind-to" json:"bindTo,omitempty"`
+			HTTPPath     string `toml:"http-path" json:"httpPath,omitempty"`
+			MetricPrefix string `toml:"metric-prefix" json:"metricPrefix,omitempty"`
+		} `toml:"prometheus" json:"prometheus,omitempty"`
+	} `toml:"stats" json:"stats,omitempty"`
+	DCOverrides []struct {
+		DC  uint     `toml:"dc" json:"dc"`
+		IPs []string `toml:"ips" json:"ips"`
+	} `toml:"dc-overrides" json:"dcOverrides,omitempty"`
+}
+
+func Parse(rawData []byte) (*Config, error) {
+	tomlConf := &tomlConfig{}
+	jsonBuf := &bytes.Buffer{}
+	conf := &Config{}
+
+	jsonEncoder := json.NewEncoder(jsonBuf)
+	jsonEncoder.SetEscapeHTML(false)
+	jsonEncoder.SetIndent("", "")
+
+	if err := toml.Unmarshal(rawData, tomlConf); err != nil {
+		return nil, fmt.Errorf("cannot parse toml config: %w", err)
+	}
+
+	if err := jsonEncoder.Encode(tomlConf); err != nil {
+		panic(err)
+	}
+
+	if err := json.NewDecoder(jsonBuf).Decode(conf); err != nil {
+		return nil, fmt.Errorf("cannot parse a config: %w", err)
+	}
+
+	return conf, nil
+}

internal/config/testdata/broken.toml

@@ -0,0 +1 @@
+s = sdfsdfds

internal/config/testdata/minimal.toml

@@ -0,0 +1,2 @@
+secret = "7oe1GqLy6TBc38CV3jx7q09nb29nbGUuY29t"
+bind-to = "0.0.0.0:3128"

internal/config/testdata/only_secret.toml

@@ -0,0 +1 @@
+secret = "7oe1GqLy6TBc38CV3jx7q09nb29nbGUuY29t"

internal/config/type_blocklist_uri.go

@@ -0,0 +1,77 @@
+package config
+
+import (
+	"fmt"
+	"net/url"
+	"os"
+	"path/filepath"
+)
+
+type TypeBlocklistURI struct {
+	Value string
+}
+
+func (t *TypeBlocklistURI) Set(value string) error {
+	if stat, err := os.Stat(value); err == nil || os.IsExist(err) {
+		switch {
+		case stat.IsDir():
+			return fmt.Errorf("value is correct filepath but directory")
+		case stat.Mode().Perm()&0o400 == 0:
+			return fmt.Errorf("value is correct filepath but not readable")
+		}
+
+		value, err = filepath.Abs(value)
+		if err != nil {
+			return fmt.Errorf(
+				"value is correct filepath but cannot resolve absolute (%s): %w",
+				value, err)
+		}
+
+		t.Value = value
+
+		return nil
+	}
+
+	parsedURL, err := url.Parse(value)
+	if err != nil {
+		return fmt.Errorf("incorrect url (%s): %w", value, err)
+	}
+
+	switch parsedURL.Scheme {
+	case "http", "https":
+	default:
+		return fmt.Errorf("unknown schema %s (%s)", parsedURL.Scheme, value)
+	}
+
+	if parsedURL.Host == "" {
+		return fmt.Errorf("incorrect url %s", value)
+	}
+
+	t.Value = parsedURL.String()
+
+	return nil
+}
+
+func (t TypeBlocklistURI) Get(defaultValue string) string {
+	if t.Value == "" {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t TypeBlocklistURI) IsRemote() bool {
+	return !filepath.IsAbs(t.Value)
+}
+
+func (t *TypeBlocklistURI) UnmarshalText(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeBlocklistURI) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeBlocklistURI) String() string {
+	return t.Value
+}

internal/config/type_blocklist_uri_test.go

@@ -0,0 +1,113 @@
+package config_test
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeBlocklistURITestStruct struct {
+	Value config.TypeBlocklistURI `json:"value"`
+}
+
+type TypeBlocklistURITestSuite struct {
+	suite.Suite
+
+	directory    string
+	absDirectory string
+}
+
+func (suite *TypeBlocklistURITestSuite) SetupSuite() {
+	dir, _ := os.Getwd()
+	absDir, _ := filepath.Abs(dir)
+
+	suite.directory = dir
+	suite.absDirectory = absDir
+}
+
+func (suite *TypeBlocklistURITestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"gopher://lalala",
+		"https:///paths",
+		"h:/=",
+		filepath.Join(suite.directory, "___"),
+		filepath.Join(suite.absDirectory, "___"),
+		suite.directory,
+		suite.absDirectory,
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeBlocklistURITestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeBlocklistURITestSuite) TestUnmarshalOk() {
+	testData := []string{
+		"http://lalala",
+		"https://lalala",
+		"https://lalala/path",
+		filepath.Join(suite.directory, "config.go"),
+		filepath.Join(suite.absDirectory, "config.go"),
+	}
+
+	for _, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			testStruct := &typeBlocklistURITestStruct{}
+
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.EqualValues(t, value, testStruct.Value.Get(""))
+
+			if strings.HasPrefix(value, "http") {
+				assert.True(t, testStruct.Value.IsRemote())
+			} else {
+				assert.False(t, testStruct.Value.IsRemote())
+			}
+		})
+	}
+}
+
+func (suite *TypeBlocklistURITestSuite) TestMarshalOk() {
+	testStruct := &typeBlocklistURITestStruct{
+		Value: config.TypeBlocklistURI{
+			Value: "http://some.url/with/path",
+		},
+	}
+
+	data, err := json.Marshal(testStruct)
+	suite.NoError(err)
+	suite.JSONEq(`{"value": "http://some.url/with/path"}`, string(data))
+}
+
+func (suite *TypeBlocklistURITestSuite) TestGet() {
+	value := config.TypeBlocklistURI{}
+	suite.Equal("/path", value.Get("/path"))
+
+	suite.NoError(value.Set("http://lalala.ru"))
+	suite.Equal("http://lalala.ru", value.Get("/path"))
+	suite.Equal("http://lalala.ru", value.Get(""))
+}
+
+func TestTypeBlocklistURI(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeBlocklistURITestSuite{})
+}

internal/config/type_bool.go

@@ -0,0 +1,37 @@
+package config
+
+import (
+	"fmt"
+	"strconv"
+)
+
+type TypeBool struct {
+	Value bool
+}
+
+func (t *TypeBool) Set(data string) error {
+	parsed, err := strconv.ParseBool(data)
+	if err != nil {
+		return fmt.Errorf("incorrect bool value: %s", data)
+	}
+
+	t.Value = parsed
+
+	return nil
+}
+
+func (t TypeBool) Get(defaultValue bool) bool {
+	return t.Value || defaultValue
+}
+
+func (t *TypeBool) UnmarshalJSON(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeBool) MarshalJSON() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeBool) String() string {
+	return strconv.FormatBool(t.Value)
+}

internal/config/type_bool_test.go

@@ -0,0 +1,107 @@
+package config_test
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeBoolTestStruct struct {
+	Value config.TypeBool `json:"value"`
+}
+
+type TypeBoolTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypeBoolTestSuite) TestUnmarshalFail() {
+	testData := []interface{}{
+		"",
+		"np",
+		"нет",
+		int(10),
+		[]int{},
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]interface{}{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(fmt.Sprintf("%v", v), func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeBoolTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeBoolTestSuite) TestUnmarshalOk() {
+	testData := []bool{
+		true,
+		false,
+	}
+
+	for _, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]bool{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(strconv.FormatBool(v), func(t *testing.T) {
+			testStruct := &typeBoolTestStruct{}
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+
+			if value {
+				assert.True(t, testStruct.Value.Value)
+			} else {
+				assert.False(t, testStruct.Value.Value)
+			}
+		})
+	}
+}
+
+func (suite *TypeBoolTestSuite) TestMarshalOk() {
+	for _, v := range []bool{true, false} {
+		value := v
+
+		suite.T().Run(strconv.FormatBool(v), func(t *testing.T) {
+			testStruct := typeBoolTestStruct{
+				Value: config.TypeBool{
+					Value: value,
+				},
+			}
+
+			encodedJSON, err := json.Marshal(testStruct)
+			assert.NoError(t, err)
+
+			expectedJSON, err := json.Marshal(map[string]bool{
+				"value": value,
+			})
+			assert.NoError(t, err)
+
+			assert.JSONEq(t, string(expectedJSON), string(encodedJSON))
+		})
+	}
+}
+
+func (suite *TypeBoolTestSuite) TestGet() {
+	value := config.TypeBool{}
+	suite.False(value.Get(false))
+	suite.True(value.Get(true))
+
+	value.Value = true
+	suite.True(value.Get(false))
+	suite.True(value.Get(true))
+}
+
+func TestTypeBool(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeBoolTestSuite{})
+}

internal/config/type_bytes.go

@@ -0,0 +1,55 @@
+package config
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/alecthomas/units"
+)
+
+var typeBytesStringCleaner = strings.NewReplacer(" ", "", "\t", "", "IB", "iB")
+
+type TypeBytes struct {
+	Value units.Base2Bytes
+}
+
+func (t *TypeBytes) Set(value string) error {
+	normalizedValue := typeBytesStringCleaner.Replace(strings.ToUpper(value))
+
+	parsedValue, err := units.ParseBase2Bytes(normalizedValue)
+	if err != nil {
+		return fmt.Errorf("incorrect bytes value (%v): %w", value, err)
+	}
+
+	if parsedValue < 0 {
+		return fmt.Errorf("bytes should be positive (%s)", value)
+	}
+
+	t.Value = parsedValue
+
+	return nil
+}
+
+func (t TypeBytes) Get(defaultValue uint) uint {
+	if t.Value == 0 {
+		return defaultValue
+	}
+
+	return uint(t.Value)
+}
+
+func (t *TypeBytes) UnmarshalText(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeBytes) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeBytes) String() string {
+	if t.Value == 0 {
+		return ""
+	}
+
+	return strings.ToLower(t.Value.String())
+}

internal/config/type_bytes_test.go

@@ -0,0 +1,86 @@
+package config_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeBytesTestStruct struct {
+	Value config.TypeBytes `json:"value"`
+}
+
+type TypeBytesTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypeBytesTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"1m",
+		"1",
+		"-1kb",
+		"-1kib",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeBytesTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeBytesTestSuite) TestUnmarshalOk() {
+	testData := map[string]uint{
+		"1b":   1,
+		"1kb":  1024,
+		"1kib": 1024,
+		"2mb":  2 * 1024 * 1024,
+		"2mib": 2 * 1024 * 1024,
+	}
+
+	for k, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": k,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(k, func(t *testing.T) {
+			testStruct := &typeBytesTestStruct{}
+
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.EqualValues(t, value, testStruct.Value.Get(0))
+		})
+	}
+}
+
+func (suite *TypeBytesTestSuite) TestMarshalOk() {
+	value := typeBytesTestStruct{}
+	suite.NoError(value.Value.Set("1kib"))
+
+	data, err := json.Marshal(value)
+	suite.NoError(err)
+	suite.JSONEq(`{"value": "1kib"}`, string(data))
+}
+
+func (suite *TypeBytesTestSuite) TestGet() {
+	value := config.TypeBytes{}
+	suite.EqualValues(1000, value.Get(1000))
+
+	suite.NoError(value.Set("1mib"))
+	suite.EqualValues(1048576, value.Get(1000))
+}
+
+func TestTypeBytes(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeBytesTestSuite{})
+}

internal/config/type_concurrency.go

@@ -0,0 +1,45 @@
+package config
+
+import (
+	"fmt"
+	"strconv"
+)
+
+type TypeConcurrency struct {
+	Value uint
+}
+
+func (t *TypeConcurrency) Set(value string) error {
+	concurrencyValue, err := strconv.ParseUint(value, 10, 16)
+	if err != nil {
+		return fmt.Errorf("value is not uint (%s): %w", value, err)
+	}
+
+	if concurrencyValue == 0 {
+		return fmt.Errorf("value should be >0 (%s)", value)
+	}
+
+	t.Value = uint(concurrencyValue)
+
+	return nil
+}
+
+func (t TypeConcurrency) Get(defaultValue uint) uint {
+	if t.Value == 0 {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypeConcurrency) UnmarshalJSON(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeConcurrency) MarshalJSON() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeConcurrency) String() string {
+	return strconv.FormatUint(uint64(t.Value), 10)
+}

internal/config/type_concurrency_test.go

@@ -0,0 +1,73 @@
+package config_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeConcurrencyTestStruct struct {
+	Value config.TypeConcurrency `json:"value"`
+}
+
+type TypeConcurrencyTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypeConcurrencyTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"-1",
+		"0",
+		"0.0",
+		"1.0",
+		"1.1",
+		".",
+		"some_value",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeConcurrencyTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeConcurrencyTestSuite) TestUnmarshalOk() {
+	testStruct := &typeConcurrencyTestStruct{}
+
+	suite.NoError(json.Unmarshal([]byte(`{"value": 1}`), testStruct))
+	suite.EqualValues(1, testStruct.Value.Get(2))
+}
+
+func (suite *TypeConcurrencyTestSuite) TestMarshalOk() {
+	testStruct := &typeConcurrencyTestStruct{
+		Value: config.TypeConcurrency{
+			Value: 2,
+		},
+	}
+
+	data, err := json.Marshal(testStruct)
+	suite.NoError(err)
+	suite.JSONEq(`{"value": 2}`, string(data))
+}
+
+func (suite *TypeConcurrencyTestSuite) TestGet() {
+	value := config.TypeConcurrency{}
+	suite.EqualValues(1, value.Get(1))
+
+	value.Value = 3
+	suite.EqualValues(3, value.Get(1))
+}
+
+func TestTypeConcurrency(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeConcurrencyTestSuite{})
+}

internal/config/type_dc.go

@@ -0,0 +1,41 @@
+package config
+
+import (
+	"fmt"
+	"strconv"
+)
+
+type TypeDC struct {
+	Value int
+}
+
+func (t *TypeDC) Set(value string) error {
+	parsed, err := strconv.ParseInt(value, 10, 16)
+	if err != nil {
+		return fmt.Errorf("cannot parse dc: %w", err)
+	}
+
+	if parsed < 0 {
+		parsed = -parsed
+	}
+
+	t.Value = int(parsed)
+
+	return nil
+}
+
+func (t *TypeDC) UnmarshalJSON(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeDC) MarshalJSON() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeDC) String() string {
+	return strconv.Itoa(t.Value)
+}
+
+func (t TypeDC) Get() int {
+	return t.Value
+}

internal/config/type_dc_test.go

@@ -0,0 +1,96 @@
+package config_test
+
+import (
+	"encoding/json"
+	"strconv"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeDCTestStruct struct {
+	Value config.TypeDC `json:"value"`
+}
+
+type TypeDCTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypeDCTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"-1s",
+		"1202002020202",
+		"xxx",
+		"-11111111111111",
+		"",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeDCTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeDCTestSuite) TestUnmarshalOk() {
+	testData := map[int]int{
+		1:   1,
+		-1:  1,
+		203: 203,
+	}
+
+	for value, expected := range testData {
+		data, err := json.Marshal(map[string]int{
+			"value": value,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(strconv.Itoa(value), func(t *testing.T) {
+			testStruct := &typeDCTestStruct{}
+
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.Equal(t, expected, testStruct.Value.Value)
+			assert.Equal(t, expected, testStruct.Value.Get())
+		})
+	}
+}
+
+func (suite *TypeDCTestSuite) TestMarshalOk() {
+	testData := map[string]int{
+		"1":   1,
+		"203": 203,
+	}
+
+	for k, v := range testData {
+		value := k
+		expected := v
+
+		suite.T().Run(value, func(t *testing.T) {
+			testStruct := &typeDCTestStruct{}
+
+			assert.NoError(t, testStruct.Value.Set(value))
+
+			data, err := json.Marshal(testStruct)
+			assert.NoError(t, err)
+
+			expectedJSON, err := json.Marshal(map[string]int{
+				"value": expected,
+			})
+			assert.NoError(t, err)
+
+			assert.JSONEq(t, string(expectedJSON), string(data))
+		})
+	}
+}
+
+func TestTypeDC(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeDCTestSuite{})
+}

internal/config/type_duration.go

@@ -0,0 +1,53 @@
+package config
+
+import (
+	"fmt"
+	"strings"
+	"time"
+)
+
+var typeDurationStringCleaner = strings.NewReplacer(" ", "", "\t", "")
+
+type TypeDuration struct {
+	Value time.Duration
+}
+
+func (t *TypeDuration) Set(value string) error {
+	parsedValue, err := time.ParseDuration(
+		typeDurationStringCleaner.Replace(strings.ToLower(value)))
+	if err != nil {
+		return fmt.Errorf("incorrect duration (%s): %w", value, err)
+	}
+
+	if parsedValue < 0 {
+		return fmt.Errorf("duration has to be a positive: %s", value)
+	}
+
+	t.Value = parsedValue
+
+	return nil
+}
+
+func (t TypeDuration) Get(defaultValue time.Duration) time.Duration {
+	if t.Value == 0 {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypeDuration) UnmarshalText(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeDuration) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeDuration) String() string {
+	if t.Value == 0 {
+		return ""
+	}
+
+	return t.Value.String()
+}

internal/config/type_duration_test.go

@@ -0,0 +1,110 @@
+package config_test
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeDurationTestStruct struct {
+	Value config.TypeDuration `json:"value"`
+}
+
+type TypeDurationTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypeDurationTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"-1s",
+		"1 seconds ago",
+		"1s ago",
+		"",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeDurationTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeDurationTestSuite) TestUnmarshalOk() {
+	testData := map[string]time.Duration{
+		"1s":   time.Second,
+		"0":    0 * time.Second,
+		"0s":   0 * time.Second,
+		"1\tM": time.Minute,
+		"1H":   time.Hour,
+		"1 h":  time.Hour,
+	}
+
+	for k, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": k,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(k, func(t *testing.T) {
+			testStruct := &typeDurationTestStruct{}
+
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.Equal(t, value, testStruct.Value.Value)
+		})
+	}
+}
+
+func (suite *TypeDurationTestSuite) TestMarshalOk() {
+	testData := map[string]string{
+		"1s":  "1s",
+		"0":   "",
+		"0s":  "",
+		"0ms": "",
+		"1 H": "1h0m0s",
+	}
+
+	for k, v := range testData {
+		value := k
+		expected := v
+
+		suite.T().Run(value, func(t *testing.T) {
+			testStruct := &typeDurationTestStruct{}
+
+			assert.NoError(t, testStruct.Value.Set(value))
+
+			data, err := json.Marshal(testStruct)
+			assert.NoError(t, err)
+
+			expectedJSON, err := json.Marshal(map[string]string{
+				"value": expected,
+			})
+			assert.NoError(t, err)
+
+			assert.JSONEq(t, string(expectedJSON), string(data))
+		})
+	}
+}
+
+func (suite *TypeDurationTestSuite) TestGet() {
+	value := config.TypeDuration{}
+	suite.Equal(time.Second, value.Get(time.Second))
+
+	value.Value = 3 * time.Second
+	suite.Equal(3*time.Second, value.Get(time.Hour))
+}
+
+func TestTypeDuration(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeDurationTestSuite{})
+}

internal/config/type_error_rate.go

@@ -0,0 +1,47 @@
+package config
+
+import (
+	"fmt"
+	"strconv"
+)
+
+const typeErrorRateIgnoreLess = 1e-8
+
+type TypeErrorRate struct {
+	Value float64
+}
+
+func (t *TypeErrorRate) Set(value string) error {
+	parsedValue, err := strconv.ParseFloat(value, 64)
+	if err != nil {
+		return fmt.Errorf("value is not a float (%s): %w", value, err)
+	}
+
+	if parsedValue <= 0.0 || parsedValue >= 100.0 {
+		return fmt.Errorf("value should be 0 < x < 100 (%s)", value)
+	}
+
+	t.Value = parsedValue
+
+	return nil
+}
+
+func (t TypeErrorRate) Get(defaultValue float64) float64 {
+	if t.Value < typeErrorRateIgnoreLess {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypeErrorRate) UnmarshalJSON(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeErrorRate) MarshalJSON() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeErrorRate) String() string {
+	return strconv.FormatFloat(t.Value, 'f', -1, 64)
+}

internal/config/type_error_rate_test.go

@@ -0,0 +1,81 @@
+package config_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeErrorRateTestStruct struct {
+	Value config.TypeErrorRate `json:"value"`
+}
+
+type TypeErrorRateTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypeErrorRateTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"",
+		"1s",
+		"1,",
+		"1,2",
+		".",
+		"3.4.5",
+		"3.5.",
+		".3.5",
+		"some word",
+		"1e2",
+		"-1.0",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeErrorRateTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeErrorRateTestSuite) TestUnmarshalOk() {
+	data, err := json.Marshal(map[string]float64{
+		"value": 1.0,
+	})
+	suite.NoError(err)
+
+	testStruct := &typeErrorRateTestStruct{}
+	suite.NoError(json.Unmarshal(data, testStruct))
+	suite.InEpsilon(1.0, testStruct.Value.Value, 1e-10)
+}
+
+func (suite *TypeErrorRateTestSuite) TestMarshalOk() {
+	testStruct := typeErrorRateTestStruct{
+		Value: config.TypeErrorRate{
+			Value: 1.01,
+		},
+	}
+
+	encodedJSON, err := json.Marshal(testStruct)
+	suite.NoError(err)
+	suite.JSONEq(`{"value": 1.01}`, string(encodedJSON))
+}
+
+func (suite *TypeErrorRateTestSuite) TestGet() {
+	value := config.TypeErrorRate{}
+	suite.InEpsilon(1.0, value.Get(1.0), 1e-10)
+
+	value.Value = 5.0
+	suite.InEpsilon(5.0, value.Get(1.0), 1e-10)
+}
+
+func TestTypeErrorRate(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeErrorRateTestSuite{})
+}

internal/config/type_hostport.go

@@ -0,0 +1,63 @@
+package config
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+)
+
+type TypeHostPort struct {
+	Value string
+	Host  string
+	Port  uint
+}
+
+func (t *TypeHostPort) Set(value string) error {
+	host, port, err := net.SplitHostPort(value)
+	if err != nil {
+		return fmt.Errorf("incorrect host:port value (%v): %w", value, err)
+	}
+
+	portValue, err := strconv.ParseUint(port, 10, 16)
+	if err != nil {
+		return fmt.Errorf("incorrect port number (%v): %w", value, err)
+	}
+
+	if portValue == 0 {
+		return fmt.Errorf("incorrect port number (%s)", value)
+	}
+
+	if host == "" {
+		return fmt.Errorf("empty host: %s", value)
+	}
+
+	if net.ParseIP(host) == nil {
+		return fmt.Errorf("host is not an IP address: %s", value)
+	}
+
+	t.Value = net.JoinHostPort(host, port)
+	t.Port = uint(portValue)
+	t.Host = host
+
+	return nil
+}
+
+func (t TypeHostPort) Get(defaultValue string) string {
+	if t.Value == "" {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypeHostPort) UnmarshalText(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeHostPort) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeHostPort) String() string {
+	return t.Value
+}

internal/config/type_hostport_test.go

@@ -0,0 +1,88 @@
+package config_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeHostPortTestStruct struct {
+	Value config.TypeHostPort `json:"value"`
+}
+
+type TypeHostPortTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypeHostPortTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		":",
+		":800",
+		"127.0.0.1:8000000",
+		"12...:80",
+		"",
+		"localhost",
+		"google.com:",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeHostPortTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeHostPortTestSuite) TestUnmarshalOk() {
+	testData := []string{
+		"127.0.0.1:80",
+		"10.0.0.10:6553",
+	}
+
+	for _, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			testStruct := &typeHostPortTestStruct{}
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.Equal(t, value, testStruct.Value.Value)
+		})
+	}
+}
+
+func (suite *TypeHostPortTestSuite) TestMarshalOk() {
+	testStruct := typeHostPortTestStruct{
+		Value: config.TypeHostPort{
+			Value: "127.0.0.1:8000",
+		},
+	}
+
+	data, err := json.Marshal(testStruct)
+	suite.NoError(err)
+	suite.JSONEq(`{"value": "127.0.0.1:8000"}`, string(data))
+}
+
+func (suite *TypeHostPortTestSuite) TestGet() {
+	value := config.TypeHostPort{}
+	suite.Equal("127.0.0.1:9000", value.Get("127.0.0.1:9000"))
+
+	value.Value = "127.0.0.1:80"
+	suite.Equal("127.0.0.1:80", value.Get("127.0.0.1:9000"))
+}
+
+func TestTypeHostPort(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeHostPortTestSuite{})
+}

internal/config/type_http_path.go

@@ -0,0 +1,33 @@
+package config
+
+import "strings"
+
+type TypeHTTPPath struct {
+	Value string
+}
+
+func (t *TypeHTTPPath) Set(value string) error {
+	t.Value = "/" + strings.Trim(value, "/")
+
+	return nil
+}
+
+func (t TypeHTTPPath) Get(defaultValue string) string {
+	if t.Value == "" {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypeHTTPPath) UnmarshalText(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeHTTPPath) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeHTTPPath) String() string {
+	return t.Value
+}

internal/config/type_http_path_test.go

@@ -0,0 +1,67 @@
+package config_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeHTTPPathTestStruct struct {
+	Value config.TypeHTTPPath `json:"value"`
+}
+
+type TypeHTTPPathTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypeHTTPPathTestSuite) TestUnmarshalOk() {
+	testData := map[string]string{
+		"":      "/",
+		"/":     "/",
+		"/path": "/path",
+		"path":  "/path",
+	}
+
+	for k, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": k,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(k, func(t *testing.T) {
+			testStruct := &typeHTTPPathTestStruct{}
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.Equal(t, value, testStruct.Value.Get(""))
+		})
+	}
+}
+
+func (suite *TypeHTTPPathTestSuite) TestMarshalOk() {
+	value := typeHTTPPathTestStruct{
+		Value: config.TypeHTTPPath{
+			Value: "/path",
+		},
+	}
+
+	data, err := json.Marshal(value)
+	suite.NoError(err)
+	suite.JSONEq(`{"value": "/path"}`, string(data))
+}
+
+func (suite *TypeHTTPPathTestSuite) TestGet() {
+	value := config.TypeHTTPPath{}
+	suite.Equal("/hello", value.Get("/hello"))
+
+	suite.NoError(value.Set("/lalala"))
+	suite.Equal("/lalala", value.Get("/hello"))
+}
+
+func TestTypeHTTPPath(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeHTTPPathTestSuite{})
+}

internal/config/type_ip.go

@@ -0,0 +1,45 @@
+package config
+
+import (
+	"fmt"
+	"net"
+)
+
+type TypeIP struct {
+	Value net.IP
+}
+
+func (t *TypeIP) Set(value string) error {
+	ip := net.ParseIP(value)
+	if ip == nil {
+		return fmt.Errorf("incorret ip %s", value)
+	}
+
+	t.Value = ip
+
+	return nil
+}
+
+func (t *TypeIP) Get(defaultValue net.IP) net.IP {
+	if len(t.Value) == 0 {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypeIP) UnmarshalText(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeIP) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeIP) String() string {
+	if len(t.Value) == 0 {
+		return ""
+	}
+
+	return t.Value.String()
+}

internal/config/type_ip_test.go

@@ -0,0 +1,104 @@
+package config_test
+
+import (
+	"encoding/json"
+	"net"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeIPTestStruct struct {
+	Value config.TypeIP `json:"value"`
+}
+
+type TypeIPTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypeIPTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"",
+		"....",
+		"0...",
+		"300.200.200.800",
+		"[]",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeIPTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeIPTestSuite) TestUnmarshalOk() {
+	testData := map[string]string{
+		"2001:0db8:85a3:0000:0000:8a2e:0370:7334": "2001:db8:85a3::8a2e:370:7334",
+		"127.0.0.1": "127.0.0.1",
+	}
+
+	for k, v := range testData {
+		expected := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": k,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(k, func(t *testing.T) {
+			testStruct := &typeIPTestStruct{}
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.Equal(t, expected, testStruct.Value.Get(nil).String())
+		})
+	}
+}
+
+func (suite *TypeIPTestSuite) TestMarshalOk() {
+	testData := []string{
+		"2001:db8:85a3::8a2e:370:7334",
+		"127.0.0.1",
+	}
+
+	for _, v := range testData {
+		value := v
+
+		suite.T().Run(v, func(t *testing.T) {
+			testStruct := &typeIPTestStruct{
+				Value: config.TypeIP{
+					Value: net.ParseIP(value),
+				},
+			}
+
+			encodedJSON, err := json.Marshal(testStruct)
+			assert.NoError(t, err)
+
+			expectedJSON, err := json.Marshal(map[string]string{
+				"value": value,
+			})
+			assert.NoError(t, err)
+
+			assert.JSONEq(t, string(expectedJSON), string(encodedJSON))
+		})
+	}
+}
+
+func (suite *TypeIPTestSuite) TestGet() {
+	value := config.TypeIP{}
+	suite.Equal("127.0.0.1", value.Get(net.ParseIP("127.0.0.1")).String())
+
+	suite.NoError(value.Set("127.0.0.2"))
+	suite.Equal("127.0.0.2", value.Get(net.ParseIP("127.0.0.1")).String())
+}
+
+func TestTypeIP(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeIPTestSuite{})
+}

internal/config/type_metric_prefix.go

@@ -0,0 +1,40 @@
+package config
+
+import (
+	"fmt"
+	"regexp"
+)
+
+type TypeMetricPrefix struct {
+	Value string
+}
+
+func (t *TypeMetricPrefix) Set(value string) error {
+	if ok, err := regexp.MatchString("^[a-z0-9]+$", value); !ok || err != nil {
+		return fmt.Errorf("incorrect metric prefix %s: %w", value, err)
+	}
+
+	t.Value = value
+
+	return nil
+}
+
+func (t TypeMetricPrefix) Get(defaultValue string) string {
+	if t.Value == "" {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypeMetricPrefix) UnmarshalText(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeMetricPrefix) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeMetricPrefix) String() string {
+	return t.Value
+}

internal/config/type_metric_prefix_test.go

@@ -0,0 +1,70 @@
+package config_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeMetricPrefixTestStruct struct {
+	Value config.TypeMetricPrefix `json:"value"`
+}
+
+type TypeMetricPrefixTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypeMetricPrefixTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"",
+		"-",
+		"hello/world",
+		"lala*",
+		"++sdf++",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeMetricPrefixTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypeMetricPrefixTestSuite) TestUnmarshalOk() {
+	testStruct := &typeMetricPrefixTestStruct{}
+	suite.NoError(json.Unmarshal([]byte(`{"value": "mtg"}`), testStruct))
+	suite.Equal("mtg", testStruct.Value.Get("lalala"))
+}
+
+func (suite *TypeMetricPrefixTestSuite) TestMarshalOk() {
+	testStruct := &typeMetricPrefixTestStruct{
+		Value: config.TypeMetricPrefix{
+			Value: "mtg",
+		},
+	}
+
+	data, err := json.Marshal(testStruct)
+	suite.NoError(err)
+	suite.JSONEq(`{"value": "mtg"}`, string(data))
+}
+
+func (suite *TypeMetricPrefixTestSuite) TestGet() {
+	value := config.TypeMetricPrefix{}
+	suite.Equal("lalala", value.Get("lalala"))
+
+	value.Value = "mtg"
+	suite.Equal("mtg", value.Get("lalala"))
+}
+
+func TestTypeMetricPrefix(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypeMetricPrefixTestSuite{})
+}

internal/config/type_port.go

@@ -0,0 +1,45 @@
+package config
+
+import (
+	"fmt"
+	"strconv"
+)
+
+type TypePort struct {
+	Value uint
+}
+
+func (t *TypePort) Set(value string) error {
+	portValue, err := strconv.ParseUint(value, 10, 16)
+	if err != nil {
+		return fmt.Errorf("incorrect port number (%v): %w", value, err)
+	}
+
+	if portValue == 0 {
+		return fmt.Errorf("incorrect port number (%s)", value)
+	}
+
+	t.Value = uint(portValue)
+
+	return nil
+}
+
+func (t TypePort) Get(defaultValue uint) uint {
+	if t.Value == 0 {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypePort) UnmarshalJSON(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypePort) MarshalJSON() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypePort) String() string {
+	return strconv.Itoa(int(t.Value))
+}

internal/config/type_port_test.go

@@ -0,0 +1,71 @@
+package config_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typePortTestStruct struct {
+	Value config.TypePort `json:"value"`
+}
+
+type TypePortTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypePortTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"",
+		"port",
+		"0",
+		"-1",
+		"1.5",
+		"70000",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typePortTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypePortTestSuite) TestUnmarshalOk() {
+	testStruct := &typePortTestStruct{}
+	suite.NoError(json.Unmarshal([]byte(`{"value": 5}`), testStruct))
+	suite.EqualValues(5, testStruct.Value.Value)
+}
+
+func (suite *TypePortTestSuite) TestMarshalOk() {
+	testStruct := &typePortTestStruct{
+		Value: config.TypePort{
+			Value: 10,
+		},
+	}
+
+	data, err := json.Marshal(testStruct)
+	suite.NoError(err)
+	suite.JSONEq(`{"value":10}`, string(data))
+}
+
+func (suite *TypePortTestSuite) TestGet() {
+	value := config.TypePort{}
+	suite.EqualValues(10, value.Get(10))
+
+	value.Value = 100
+	suite.EqualValues(100, value.Get(10))
+}
+
+func TestTypePort(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypePortTestSuite{})
+}

internal/config/type_prefer_ip.go

@@ -0,0 +1,62 @@
+package config
+
+import (
+	"fmt"
+	"strings"
+)
+
+const (
+	// TypePreferIPPreferIPv4 states that you prefer to use IPv4 addresses
+	// but IPv6 is also possible.
+	TypePreferIPPreferIPv4 = "prefer-ipv4"
+
+	// TypePreferIPPreferIPv6 states that you prefer to use IPv6 addresses
+	// but IPv4 is also possible.
+	TypePreferIPPreferIPv6 = "prefer-ipv6"
+
+	// TypePreferOnlyIPv4 states that you prefer to use IPv4 addresses
+	// only.
+	TypePreferOnlyIPv4 = "only-ipv4"
+
+	// TypePreferOnlyIPv6 states that you prefer to use IPv6 addresses
+	// only.
+	TypePreferOnlyIPv6 = "only-ipv6"
+)
+
+type TypePreferIP struct {
+	Value string
+}
+
+func (t *TypePreferIP) Set(value string) error {
+	value = strings.ToLower(value)
+
+	switch value {
+	case TypePreferIPPreferIPv4, TypePreferIPPreferIPv6,
+		TypePreferOnlyIPv4, TypePreferOnlyIPv6:
+		t.Value = value
+
+		return nil
+	default:
+		return fmt.Errorf("unsupported ip preference: %s", value)
+	}
+}
+
+func (t *TypePreferIP) Get(defaultValue string) string {
+	if t.Value == "" {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypePreferIP) UnmarshalText(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypePreferIP) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypePreferIP) String() string {
+	return t.Value
+}

internal/config/type_prefer_ip_test.go

@@ -0,0 +1,113 @@
+package config_test
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typePreferIPTestStruct struct {
+	Value config.TypePreferIP `json:"value"`
+}
+
+type TypePreferIPTestSuite struct {
+	suite.Suite
+}
+
+func (suite *TypePreferIPTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"",
+		"prefer",
+		"preferipv4",
+		config.TypePreferIPPreferIPv4 + "_",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typePreferIPTestStruct{}))
+		})
+	}
+}
+
+func (suite *TypePreferIPTestSuite) TestUnmarshalOk() {
+	testData := []string{
+		config.TypePreferIPPreferIPv4,
+		config.TypePreferIPPreferIPv6,
+		config.TypePreferOnlyIPv4,
+		config.TypePreferOnlyIPv6,
+		strings.ToTitle(config.TypePreferOnlyIPv4),
+		strings.ToTitle(config.TypePreferOnlyIPv6),
+		strings.ToTitle(config.TypePreferIPPreferIPv4),
+		strings.ToTitle(config.TypePreferIPPreferIPv6),
+	}
+
+	for _, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			testStruct := &typePreferIPTestStruct{}
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.Equal(t, strings.ToLower(value), testStruct.Value.Value)
+		})
+	}
+}
+
+func (suite *TypePreferIPTestSuite) TestMarshalOk() {
+	testData := []string{
+		config.TypePreferIPPreferIPv4,
+		config.TypePreferIPPreferIPv6,
+		config.TypePreferOnlyIPv4,
+		config.TypePreferOnlyIPv6,
+	}
+
+	for _, v := range testData {
+		value := v
+
+		suite.T().Run(v, func(t *testing.T) {
+			testStruct := &typePreferIPTestStruct{
+				Value: config.TypePreferIP{
+					Value: value,
+				},
+			}
+
+			encodedJSON, err := json.Marshal(testStruct)
+			assert.NoError(t, err)
+
+			expectedJSON, err := json.Marshal(map[string]string{
+				"value": value,
+			})
+			assert.NoError(t, err)
+
+			assert.JSONEq(t, string(expectedJSON), string(encodedJSON))
+		})
+	}
+}
+
+func (suite *TypePreferIPTestSuite) TestGet() {
+	value := config.TypePreferIP{}
+	suite.Equal(config.TypePreferIPPreferIPv4,
+		value.Get(config.TypePreferIPPreferIPv4))
+
+	suite.NoError(value.Set(config.TypePreferIPPreferIPv6))
+	suite.Equal(config.TypePreferIPPreferIPv6,
+		value.Get(config.TypePreferIPPreferIPv4))
+}
+
+func TestTypePreferIP(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &TypePreferIPTestSuite{})
+}

internal/config/type_proxy_url.go

@@ -0,0 +1,61 @@
+package config
+
+import (
+	"fmt"
+	"net"
+	"net/url"
+)
+
+const typeProxyURLDefaultSOCKS5Port = "1080"
+
+type TypeProxyURL struct {
+	Value *url.URL
+}
+
+func (t *TypeProxyURL) Set(value string) error {
+	parsedURL, err := url.Parse(value)
+	if err != nil {
+		return fmt.Errorf("value is not corect URL (%s): %w", value, err)
+	}
+
+	if parsedURL.Host == "" {
+		return fmt.Errorf("url has to have a schema: %s", value)
+	}
+
+	if parsedURL.Scheme != "socks5" {
+		return fmt.Errorf("unsupported schema: %s", parsedURL.Scheme)
+	}
+
+	if _, _, err := net.SplitHostPort(parsedURL.Host); err != nil {
+		parsedURL.Host = net.JoinHostPort(parsedURL.Host,
+			typeProxyURLDefaultSOCKS5Port)
+	}
+
+	t.Value = parsedURL
+
+	return nil
+}
+
+func (t *TypeProxyURL) Get(defaultValue *url.URL) *url.URL {
+	if t.Value == nil {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypeProxyURL) UnmarshalText(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t TypeProxyURL) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t TypeProxyURL) String() string {
+	if t.Value == nil {
+		return ""
+	}
+
+	return t.Value.String()
+}

internal/config/type_proxy_url_test.go

@@ -0,0 +1,96 @@
+package config_test
+
+import (
+	"encoding/json"
+	"net/url"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeProxyURLTestStruct struct {
+	Value config.TypeProxyURL `json:"value"`
+}
+
+type ProxyURLTestSuite struct {
+	suite.Suite
+}
+
+func (suite *ProxyURLTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"",
+		"socks5://",
+		"://lala",
+		"/path",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeProxyURLTestStruct{}))
+		})
+	}
+}
+
+func (suite *ProxyURLTestSuite) TestUnmarshalOk() {
+	testData := map[string]string{
+		"socks5://127.0.0.1/?open_threshold=1": "socks5://127.0.0.1:1080/?open_threshold=1",
+		"socks5://127.0.0.1:80":                "socks5://127.0.0.1:80",
+	}
+
+	for k, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": k,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(k, func(t *testing.T) {
+			testStruct := &typeProxyURLTestStruct{}
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+
+			parsed, _ := url.Parse(value)
+
+			assert.Equal(t, parsed.Scheme, testStruct.Value.Get(nil).Scheme)
+			assert.Equal(t, parsed.Host, testStruct.Value.Get(nil).Host)
+			assert.Equal(t, parsed.RawQuery, testStruct.Value.Get(nil).RawQuery)
+			assert.Equal(t, parsed.Path, testStruct.Value.Get(nil).Path)
+		})
+	}
+}
+
+func (suite *ProxyURLTestSuite) TestMarshalOk() {
+	parsed, _ := url.Parse("socks5://127.0.0.1:1080?open_threshold=1")
+	testStruct := &typeProxyURLTestStruct{
+		Value: config.TypeProxyURL{
+			Value: parsed,
+		},
+	}
+
+	encodedJSON, err := json.Marshal(testStruct)
+	suite.NoError(err)
+	suite.JSONEq(`{"value": "socks5://127.0.0.1:1080?open_threshold=1"}`,
+		string(encodedJSON))
+}
+
+func (suite *ProxyURLTestSuite) TestGet() {
+	emptyURL := &url.URL{}
+
+	value := config.TypeProxyURL{}
+	suite.Equal(emptyURL, value.Get(emptyURL))
+
+	value.Value = &url.URL{}
+	suite.Equal(value.Value, value.Get(emptyURL))
+}
+
+func TestTypeProxyURL(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &ProxyURLTestSuite{})
+}

internal/config/type_statsd_tag_format.go

@@ -0,0 +1,58 @@
+package config
+
+import (
+	"fmt"
+	"strings"
+)
+
+const (
+	// TypeStatsdTagFormatInfluxdb defines a tag format compatible with
+	// InfluxDB.
+	TypeStatsdTagFormatInfluxdb = "influxdb"
+
+	// TypeStatsdTagFormatDatadog defines a tag format compatible with
+	// DataDog.
+	TypeStatsdTagFormatDatadog = "datadog"
+
+	// TypeStatsdTagFormatGraphite defines a tag format compatible with
+	// Graphite.
+	TypeStatsdTagFormatGraphite = "graphite"
+)
+
+type TypeStatsdTagFormat struct {
+	Value string
+}
+
+func (t *TypeStatsdTagFormat) Set(value string) error {
+	lowercasedValue := strings.ToLower(value)
+
+	switch lowercasedValue {
+	case TypeStatsdTagFormatDatadog, TypeStatsdTagFormatInfluxdb,
+		TypeStatsdTagFormatGraphite:
+		t.Value = lowercasedValue
+
+		return nil
+	default:
+		return fmt.Errorf("unknown tag format %s", value)
+	}
+}
+
+func (t TypeStatsdTagFormat) Get(defaultValue string) string {
+	if t.Value == "" {
+		return defaultValue
+	}
+
+	return t.Value
+}
+
+func (t *TypeStatsdTagFormat) UnmarshalText(data []byte) error {
+	return t.Set(string(data))
+}
+
+func (t *TypeStatsdTagFormat) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+func (t *TypeStatsdTagFormat) String() string {
+	return t.Value
+}

internal/config/type_statsd_tag_format_test.go

@@ -0,0 +1,108 @@
+package config_test
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type typeStatsdTagFormatTestStruct struct {
+	Value config.TypeStatsdTagFormat `json:"value"`
+}
+
+type StatsdTagFormatTestSuite struct {
+	suite.Suite
+}
+
+func (suite *StatsdTagFormatTestSuite) TestUnmarshalFail() {
+	testData := []string{
+		"",
+		"dogdog",
+	}
+
+	for _, v := range testData {
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			assert.Error(t, json.Unmarshal(data, &typeStatsdTagFormatTestStruct{}))
+		})
+	}
+}
+
+func (suite *StatsdTagFormatTestSuite) TestUnmarshalOk() {
+	testData := []string{
+		config.TypeStatsdTagFormatInfluxdb,
+		config.TypeStatsdTagFormatGraphite,
+		config.TypeStatsdTagFormatDatadog,
+		strings.ToUpper(config.TypeStatsdTagFormatInfluxdb),
+		strings.ToUpper(config.TypeStatsdTagFormatGraphite),
+		strings.ToUpper(config.TypeStatsdTagFormatDatadog),
+	}
+
+	for _, v := range testData {
+		value := v
+
+		data, err := json.Marshal(map[string]string{
+			"value": v,
+		})
+		suite.NoError(err)
+
+		suite.T().Run(v, func(t *testing.T) {
+			testStruct := &typeStatsdTagFormatTestStruct{}
+			assert.NoError(t, json.Unmarshal(data, testStruct))
+			assert.Equal(t, strings.ToLower(value), testStruct.Value.Value)
+		})
+	}
+}
+
+func (suite *StatsdTagFormatTestSuite) TestMarshalOk() {
+	testData := []string{
+		config.TypeStatsdTagFormatInfluxdb,
+		config.TypeStatsdTagFormatGraphite,
+		config.TypeStatsdTagFormatDatadog,
+	}
+
+	for _, v := range testData {
+		value := v
+
+		suite.T().Run(v, func(t *testing.T) {
+			testStruct := &typeStatsdTagFormatTestStruct{
+				Value: config.TypeStatsdTagFormat{
+					Value: value,
+				},
+			}
+
+			encodedJSON, err := json.Marshal(testStruct)
+			assert.NoError(t, err)
+
+			expectedJSON, err := json.Marshal(map[string]string{
+				"value": value,
+			})
+			assert.NoError(t, err)
+
+			assert.JSONEq(t, string(expectedJSON), string(encodedJSON))
+		})
+	}
+}
+
+func (suite *StatsdTagFormatTestSuite) TestGet() {
+	value := config.TypeStatsdTagFormat{}
+	suite.Equal(config.TypeStatsdTagFormatDatadog,
+		value.Get(config.TypeStatsdTagFormatDatadog))
+
+	suite.NoError(value.Set(config.TypeStatsdTagFormatInfluxdb))
+	suite.Equal(config.TypeStatsdTagFormatInfluxdb,
+		value.Get(config.TypeStatsdTagFormatDatadog))
+}
+
+func TestTypeStatsdTagFormat(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &StatsdTagFormatTestSuite{})
+}

internal/testlib/capture_output.go

@@ -0,0 +1,42 @@
+package testlib
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"strings"
+)
+
+func CaptureStdout(callback func()) string {
+	return captureOutput(&os.Stdout, callback)
+}
+
+func CaptureStderr(callback func()) string {
+	return captureOutput(&os.Stderr, callback)
+}
+
+func captureOutput(filefp **os.File, callback func()) string {
+	oldFp := *filefp
+
+	defer func() {
+		*filefp = oldFp
+	}()
+
+	reader, writer, _ := os.Pipe()
+	buf := &bytes.Buffer{}
+	closeChan := make(chan bool)
+
+	go func() {
+		io.Copy(buf, reader) //nolint: errcheck
+		close(closeChan)
+	}()
+
+	*filefp = writer
+
+	callback()
+
+	writer.Close() //nolint: errcheck
+	<-closeChan
+
+	return strings.TrimSpace(buf.String())
+}

internal/testlib/events_observer_mock.go

@@ -0,0 +1,7 @@
+package testlib
+
+import "github.com/stretchr/testify/mock"
+
+type EventsObserverMock struct {
+	mock.Mock
+}

internal/testlib/mtglib_antireplay_cache_mock.go

@@ -0,0 +1,11 @@
+package testlib
+
+import "github.com/stretchr/testify/mock"
+
+type MtglibAntiReplayCacheMock struct {
+	mock.Mock
+}
+
+func (m *MtglibAntiReplayCacheMock) SeenBefore(data []byte) bool {
+	return m.Called(data).Bool(0)
+}

internal/testlib/mtglib_network_mock.go

@@ -0,0 +1,31 @@
+package testlib
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/9seconds/mtg/v2/essentials"
+	"github.com/stretchr/testify/mock"
+)
+
+type MtglibNetworkMock struct {
+	mock.Mock
+}
+
+func (m *MtglibNetworkMock) Dial(network, address string) (essentials.Conn, error) {
+	args := m.Called(network, address)
+
+	return args.Get(0).(essentials.Conn), args.Error(1) //nolint: wrapcheck, forcetypeassert
+}
+
+func (m *MtglibNetworkMock) DialContext(ctx context.Context, network, address string) (essentials.Conn, error) {
+	args := m.Called(ctx, network, address)
+
+	return args.Get(0).(essentials.Conn), args.Error(1) //nolint: wrapcheck, forcetypeassert
+}
+
+func (m *MtglibNetworkMock) MakeHTTPClient(dialFunc func(ctx context.Context,
+	network, address string) (essentials.Conn, error),
+) *http.Client {
+	return m.Called(dialFunc).Get(0).(*http.Client) //nolint: forcetypeassert
+}

internal/testlib/net_conn_mock.go

@@ -0,0 +1,56 @@
+package testlib
+
+import (
+	"net"
+	"time"
+
+	"github.com/stretchr/testify/mock"
+)
+
+type EssentialsConnMock struct {
+	mock.Mock
+}
+
+func (n *EssentialsConnMock) Read(b []byte) (int, error) {
+	args := n.Called(b)
+
+	return args.Int(0), args.Error(1)
+}
+
+func (n *EssentialsConnMock) Write(b []byte) (int, error) {
+	args := n.Called(b)
+
+	return args.Int(0), args.Error(1)
+}
+
+func (n *EssentialsConnMock) Close() error {
+	return n.Called().Error(0) //nolint: wrapcheck
+}
+
+func (n *EssentialsConnMock) CloseRead() error {
+	return n.Called().Error(0) //nolint: wrapcheck
+}
+
+func (n *EssentialsConnMock) CloseWrite() error {
+	return n.Called().Error(0) //nolint: wrapcheck
+}
+
+func (n *EssentialsConnMock) LocalAddr() net.Addr {
+	return n.Called().Get(0).(net.Addr) //nolint: forcetypeassert
+}
+
+func (n *EssentialsConnMock) RemoteAddr() net.Addr {
+	return n.Called().Get(0).(net.Addr) //nolint: forcetypeassert
+}
+
+func (n *EssentialsConnMock) SetDeadline(t time.Time) error {
+	return n.Called(t).Error(0) //nolint: wrapcheck
+}
+
+func (n *EssentialsConnMock) SetReadDeadline(t time.Time) error {
+	return n.Called(t).Error(0) //nolint: wrapcheck
+}
+
+func (n *EssentialsConnMock) SetWriteDeadline(t time.Time) error {
+	return n.Called(t).Error(0) //nolint: wrapcheck
+}

internal/utils/make_qr_code_url.go

@@ -0,0 +1,19 @@
+package utils
+
+import "net/url"
+
+func MakeQRCodeURL(data string) string {
+	values := url.Values{}
+	values.Set("qzone", "4")
+	values.Set("format", "svg")
+	values.Set("data", data)
+
+	rv := url.URL{
+		Scheme:   "https",
+		Host:     "api.qrserver.com",
+		Path:     "/v1/create-qr-code",
+		RawQuery: values.Encode(),
+	}
+
+	return rv.String()
+}

internal/utils/make_qr_code_url_test.go

@@ -0,0 +1,31 @@
+package utils_test
+
+import (
+	"net/url"
+	"strings"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/utils"
+	"github.com/stretchr/testify/suite"
+)
+
+type MakeQRCodeURLTestSuite struct {
+	suite.Suite
+}
+
+func (suite *MakeQRCodeURLTestSuite) TestSomeData() {
+	value := utils.MakeQRCodeURL("some data")
+
+	parsed, err := url.Parse(value)
+	suite.NoError(err)
+
+	suite.Equal("some data", parsed.Query().Get("data"))
+	suite.Equal("svg", parsed.Query().Get("format"))
+	suite.Equal("api.qrserver.com", strings.TrimPrefix(parsed.Host, "www."))
+	suite.Equal("v1/create-qr-code", strings.Trim(parsed.Path, "/"))
+}
+
+func TestMakeQRCodeURL(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &MakeQRCodeURLTestSuite{})
+}

internal/utils/net_listener.go

@@ -0,0 +1,38 @@
+package utils
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/9seconds/mtg/v2/network"
+)
+
+type Listener struct {
+	net.Listener
+}
+
+func (l Listener) Accept() (net.Conn, error) {
+	conn, err := l.Listener.Accept()
+	if err != nil {
+		return nil, err //nolint: wrapcheck
+	}
+
+	if err := network.SetClientSocketOptions(conn, 0); err != nil {
+		conn.Close() //nolint: errcheck
+
+		return nil, fmt.Errorf("cannot set TCP options: %w", err)
+	}
+
+	return conn, nil
+}
+
+func NewListener(bindTo string, bufferSize int) (net.Listener, error) {
+	base, err := net.Listen("tcp", bindTo)
+	if err != nil {
+		return nil, fmt.Errorf("cannot build a base listener: %w", err)
+	}
+
+	return Listener{
+		Listener: base,
+	}, nil
+}

internal/utils/read_config.go

@@ -0,0 +1,26 @@
+package utils
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/9seconds/mtg/v2/internal/config"
+)
+
+func ReadConfig(path string) (*config.Config, error) {
+	content, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("cannot read config file: %w", err)
+	}
+
+	conf, err := config.Parse(content)
+	if err != nil {
+		return nil, fmt.Errorf("cannot parse config: %w", err)
+	}
+
+	if err := conf.Validate(); err != nil {
+		return nil, fmt.Errorf("invalid config: %w", err)
+	}
+
+	return conf, nil
+}

internal/utils/read_config_test.go

@@ -0,0 +1,55 @@
+package utils_test
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/internal/utils"
+	"github.com/stretchr/testify/suite"
+)
+
+type ReadConfigTestSuite struct {
+	suite.Suite
+}
+
+func (suite *ReadConfigTestSuite) GetConfigPath(filename string) string {
+	return filepath.Join("testdata", filename)
+}
+
+func (suite *ReadConfigTestSuite) TestReadMinimal() {
+	conf, err := utils.ReadConfig(suite.GetConfigPath("minimal.toml"))
+	suite.NoError(err)
+	suite.NoError(conf.Validate())
+	suite.Equal("0.0.0.0:80", conf.BindTo.Get(""))
+	suite.Equal("7mqFMMq3P2Tvvt_rPx5qhmFnb29nbGUuY29t", conf.Secret.Base64())
+}
+
+func (suite *ReadConfigTestSuite) TestReadAbsentFile() {
+	_, err := utils.ReadConfig(suite.GetConfigPath("unknown.file"))
+	suite.Error(err)
+}
+
+func (suite *ReadConfigTestSuite) TestBrokenFile() {
+	_, err := utils.ReadConfig(suite.GetConfigPath("broken.toml"))
+	suite.Error(err)
+}
+
+func (suite *ReadConfigTestSuite) TestMissedBindTo() {
+	_, err := utils.ReadConfig(suite.GetConfigPath("missed-bindto.toml"))
+	suite.Error(err)
+}
+
+func (suite *ReadConfigTestSuite) TestMissedSecret() {
+	_, err := utils.ReadConfig(suite.GetConfigPath("missed-secret.toml"))
+	suite.Error(err)
+}
+
+func (suite *ReadConfigTestSuite) TestEmpty() {
+	_, err := utils.ReadConfig(suite.GetConfigPath("empty.toml"))
+	suite.Error(err)
+}
+
+func TestReadConfig(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &ReadConfigTestSuite{})
+}

internal/utils/root_context.go

@@ -0,0 +1,26 @@
+//go:build !windows
+// +build !windows
+
+package utils
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+func RootContext() context.Context {
+	ctx, cancel := context.WithCancel(context.Background())
+	sigChan := make(chan os.Signal, 1)
+
+	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+
+	go func() {
+		for range sigChan {
+			cancel()
+		}
+	}()
+
+	return ctx
+}

internal/utils/root_context_windows.go

@@ -0,0 +1,24 @@
+//go:build windows
+// +build windows
+
+package utils
+
+import (
+	"context"
+	"os"
+	"os/signal"
+)
+
+func RootContext() context.Context {
+	ctx, cancel := context.WithCancel(context.Background())
+	sigChan := make(chan os.Signal, 1)
+
+	signal.Notify(sigChan, os.Interrupt)
+	go func() {
+		for range sigChan {
+			cancel()
+		}
+	}()
+
+	return ctx
+}

internal/utils/testdata/broken.toml

@@ -0,0 +1 @@
+11

internal/utils/testdata/minimal.toml

@@ -0,0 +1,2 @@
+secret = "7mqFMMq3P2Tvvt_rPx5qhmFnb29nbGUuY29t"
+bind-to = "0.0.0.0:80"

internal/utils/testdata/missed-bindto.toml

@@ -0,0 +1,2 @@
+
+secret = "7mqFMMq3P2Tvvt_rPx5qhmFnb29nbGUuY29t"

internal/utils/testdata/missed-secret.toml

@@ -0,0 +1 @@
+bind-to = "0.0.0.0:80"

ipblocklist/files/doc.go

@@ -0,0 +1,8 @@
+// files defines a set of abstraction for 'files': an openable entities that
+// could be read after.
+//
+// This is not a file on a filesystem of your local machine, it also can
+// include "in memory" files or even remote ones, like HTTP endpoints. If you
+// make a GET request to HTTP endpoint, then a body is readable and you can
+// consider it as an openable file.
+package files

ipblocklist/files/http.go

@@ -0,0 +1,65 @@
+package files
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+)
+
+type httpFile struct {
+	http *http.Client
+	url  string
+}
+
+func (h httpFile) Open(ctx context.Context) (io.ReadCloser, error) {
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, h.url, nil)
+	if err != nil {
+		panic(err)
+	}
+
+	response, err := h.http.Do(request)
+	if err != nil {
+		if response != nil {
+			io.Copy(io.Discard, response.Body) //nolint: errcheck
+			response.Body.Close()              //nolint: errcheck
+		}
+
+		return nil, fmt.Errorf("cannot get url %s: %w", h.url, err)
+	}
+
+	if response.StatusCode >= http.StatusBadRequest {
+		return nil, fmt.Errorf("unexpected status code %d", response.StatusCode)
+	}
+
+	return response.Body, nil
+}
+
+func (h httpFile) String() string {
+	return h.url
+}
+
+// NewHTTP returns a file abstraction for HTTP/HTTPS endpoint. You also need to
+// provide a valid instance of [http.Client] to access it.
+func NewHTTP(client *http.Client, endpoint string) (File, error) {
+	if client == nil {
+		return nil, ErrBadHTTPClient
+	}
+
+	parsed, err := url.Parse(endpoint)
+	if err != nil {
+		return nil, fmt.Errorf("incorrect url %s: %w", endpoint, err)
+	}
+
+	switch parsed.Scheme {
+	case "http", "https":
+	default:
+		return nil, fmt.Errorf("unsupported url %s", endpoint)
+	}
+
+	return httpFile{
+		http: client,
+		url:  endpoint,
+	}, nil
+}

ipblocklist/files/http_test.go

@@ -0,0 +1,90 @@
+package files_test
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/ipblocklist/files"
+	"github.com/stretchr/testify/suite"
+)
+
+type HTTPTestSuite struct {
+	suite.Suite
+
+	httpClient *http.Client
+	httpServer *httptest.Server
+	ctx        context.Context
+	ctxCancel  context.CancelFunc
+}
+
+func (suite *HTTPTestSuite) makeFile(path string) (files.File, error) {
+	return files.NewHTTP(suite.httpClient, suite.httpServer.URL+"/"+path) //nolint: wrapcheck
+}
+
+func (suite *HTTPTestSuite) SetupSuite() {
+	mux := http.NewServeMux()
+
+	mux.Handle("/", http.FileServer(http.Dir("testdata")))
+
+	suite.httpServer = httptest.NewServer(mux)
+	suite.httpClient = suite.httpServer.Client()
+}
+
+func (suite *HTTPTestSuite) SetupTest() {
+	suite.ctx, suite.ctxCancel = context.WithCancel(context.Background())
+}
+
+func (suite *HTTPTestSuite) TearDownTest() {
+	suite.ctxCancel()
+	suite.httpServer.CloseClientConnections()
+}
+
+func (suite *HTTPTestSuite) TearDownSuite() {
+	suite.httpServer.Close()
+}
+
+func (suite *HTTPTestSuite) TestBadURL() {
+	_, err := files.NewHTTP(suite.httpClient, "sdfsdf")
+	suite.Error(err)
+}
+
+func (suite *HTTPTestSuite) TestBadSchema() {
+	_, err := files.NewHTTP(suite.httpClient, "gopher://lala")
+	suite.Error(err)
+}
+
+func (suite *HTTPTestSuite) TestNilHTTPClient() {
+	_, err := files.NewHTTP(nil, "")
+	suite.Error(err)
+}
+
+func (suite *HTTPTestSuite) TestAbsentFile() {
+	file, err := suite.makeFile("absent")
+	suite.NoError(err)
+
+	_, err = file.Open(suite.ctx)
+	suite.Error(err)
+}
+
+func (suite *HTTPTestSuite) TestOk() {
+	file, err := suite.makeFile("readable")
+	suite.NoError(err)
+
+	readCloser, err := file.Open(suite.ctx)
+	suite.NoError(err)
+
+	defer readCloser.Close() //nolint: errcheck
+
+	data, err := io.ReadAll(readCloser)
+	suite.NoError(err)
+	suite.Equal("Hooray!", strings.TrimSpace(string(data)))
+}
+
+func TestHTTP(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &HTTPTestSuite{})
+}

ipblocklist/files/init.go

@@ -0,0 +1,21 @@
+package files
+
+import (
+	"context"
+	"errors"
+	"io"
+)
+
+// ErrBadHTTPClient is returned if given HTTP client is initialized
+// incorrectly.
+var ErrBadHTTPClient = errors.New("incorrect http client")
+
+// File is an abstraction for a entity that can be opened in some context.
+type File interface {
+	// Open returns an readable entity for a file. It is important to not forget
+	// to close it after the usage.
+	Open(context.Context) (io.ReadCloser, error)
+
+	// String returns a short text description for the file
+	String() string
+}