Merge remote-tracking branch 'origin/master' into stable

Golangcilint 1.43.0

.github/workflows/ci.yaml

@@ -2,6 +2,18 @@
 
 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:
@@ -71,12 +83,12 @@ jobs:
       - name: Run linter
         uses: golangci/golangci-lint-action@v2
         with:
-          version: v1.42.0
+          version: v1.43.0
 
   docker:
     name: Docker
     runs-on: ubuntu-latest
-    timeout-minutes: 15
+    timeout-minutes: 20
     steps:
       - name: Checkout
         uses: actions/checkout@v2

.github/workflows/codeql-analysis.yml

@@ -11,6 +11,14 @@
 #
 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: 

.golangci.toml

@@ -9,4 +9,4 @@ format = "colored-line-number"
 
 [linters]
 enable-all = true
-disable = ["gochecknoglobals", "gas", "goerr113", "exhaustivestruct"]
+disable = ["ireturn", "varnamelen", "gochecknoglobals", "gas", "goerr113", "exhaustivestruct"]

Makefile

@@ -2,7 +2,7 @@ ROOT_DIR     := $(shell dirname $(realpath $(lastword $(MAKEFILE_LIST))))
 IMAGE_NAME   := mtg
 APP_NAME     := $(IMAGE_NAME)
 
-GOLANGCI_LINT_VERSION := v1.42.0
+GOLANGCI_LINT_VERSION := v1.43.0
 
 VERSION_GO         := $(shell go version)
 VERSION_DATE       := $(shell date -Ru)
@@ -39,7 +39,7 @@ vendor: go.mod go.sum
 
 .PHONY: fmt
 fmt:
-	@$(GOTOOL) gofumpt -w -s -extra "$(ROOT_DIR)"
+	@$(GOTOOL) gofumpt -w -extra "$(ROOT_DIR)"
 
 .PHONY: test
 test:
@@ -83,16 +83,16 @@ install-tools-lint: .bin
 
 .PHONY: install-tools-godoc
 install-tools-godoc: .bin
-	@$(GOTOOL) go get -u golang.org/x/tools/cmd/godoc
+	@$(GOTOOL) go install golang.org/x/tools/cmd/godoc@latest
 
 .PHONY: install-tools-gofumpt
 install-tools-gofumpt: .bin
-	@$(GOTOOL) go get -u mvdan.cc/gofumpt
+	@$(GOTOOL) go install mvdan.cc/gofumpt@latest
 
 .PHONY: goreleaser
 install-tools-goreleaser: .bin
-	@$(GOTOOL) go get -u github.com/goreleaser/goreleaser
+	@$(GOTOOL) go install github.com/goreleaser/goreleaser@latest
 
 .PHONY: update-deps
 update-deps:
-	@go get -u && go mod tidy
+	@go get -u && go mod tidy -go=1.17

README.md

@@ -196,7 +196,7 @@ go get github.com/9seconds/mtg/v2
 #### Build from sources
 
 ```console
-git clone https://github.com:9seconds/mtg.git
+git clone https://github.com/9seconds/mtg.git
 cd mtg
 make static
 ```

essentials/conns.go

@@ -0,0 +1,26 @@
+package essentials
+
+import (
+	"io"
+	"net"
+)
+
+// CloseableReader is a reader interface that can close its reading end.
+type CloseableReader interface {
+	io.Reader
+	CloseRead() error
+}
+
+// CloseableWriter is a 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

example.config.toml

@@ -30,7 +30,9 @@ 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.
-tcp-buffer = "4kb"
+#
+# 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:
@@ -56,6 +58,19 @@ domain-fronting-port = 443
 # 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
+
 # network defines different network-related settings
 [network]
 # please be aware that mtg needs to do some external requests. For
@@ -161,6 +176,27 @@ urls = [
 # 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

go.mod

@@ -4,32 +4,34 @@ go 1.17
 
 require (
 	github.com/OneOfOne/xxhash v1.2.8
-	github.com/alecthomas/kong v0.2.17
-	github.com/alecthomas/units v0.0.0-20210208195552-ff826a37aa15
+	github.com/alecthomas/kong v0.2.19
+	github.com/alecthomas/units v0.0.0-20210927113745-59d0afb8317a
 	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/golang/protobuf v1.5.2 // indirect
 	github.com/gotd/td v0.34.0
 	github.com/jarcoal/httpmock v1.0.8
-	github.com/kentik/patricia v0.0.0-20201202224819-f9447a6e25f1
+	github.com/kentik/patricia v0.0.0-20210909164817-21603333b70e
 	github.com/mccutchen/go-httpbin v1.1.1
-	github.com/panjf2000/ants/v2 v2.4.6
-	github.com/pelletier/go-toml v1.9.3
+	github.com/panjf2000/ants/v2 v2.4.7
+	github.com/pelletier/go-toml v1.9.4
 	github.com/prometheus/client_golang v1.11.0
-	github.com/prometheus/common v0.30.0 // indirect
+	github.com/prometheus/common v0.32.1 // indirect
 	github.com/prometheus/procfs v0.7.3 // indirect
-	github.com/rs/zerolog v1.24.0
+	github.com/rs/zerolog v1.26.0
 	github.com/smira/go-statsd v1.3.2
 	github.com/stretchr/objx v0.3.0 // indirect
 	github.com/stretchr/testify v1.7.0
 	github.com/tylertreat/BoomFilters v0.0.0-20210315201527-1a82519a3e43
-	golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97
-	golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985
-	golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c
+	golang.org/x/crypto v0.0.0-20211202192323-5770296d904e
+	golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2 // indirect
+	golang.org/x/sys v0.0.0-20211124211545-fe61309f8881
 	google.golang.org/protobuf v1.27.1 // indirect
 )
 
+require github.com/txthinking/socks5 v0.0.0-20211121111206-e03c1217a50b
+
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cenkalti/backoff/v4 v4.1.0 // indirect
@@ -38,9 +40,12 @@ require (
 	github.com/gotd/ige v0.1.5 // indirect
 	github.com/gotd/xor v0.1.1 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/patrickmn/go-cache v2.1.0+incompatible // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/txthinking/runnergroup v0.0.0-20210608031112-152c7c4432bf // indirect
+	github.com/txthinking/x v0.0.0-20210326105829-476fab902fbe // indirect
 	go.uber.org/atomic v1.7.0 // indirect
 	go.uber.org/multierr v1.6.0 // indirect
 	go.uber.org/zap v1.16.0 // indirect

go.sum

@@ -37,15 +37,15 @@ github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym
 github.com/OneOfOne/xxhash v1.2.8 h1:31czK/TI9sNkxIKfaUfGlU47BAxQ0ztGgd9vPyqimf8=
 github.com/OneOfOne/xxhash v1.2.8/go.mod h1:eZbhyaAYD41SGSSsnmcpxVoRiQ/MPUTjUdIIOT9Um7Q=
 github.com/PuerkitoBio/goquery v1.6.1/go.mod h1:GsLWisAFVj4WgDibEWF4pvYnkVQBpKBKeU+7zCJoLcc=
-github.com/alecthomas/kong v0.2.17 h1:URDISCI96MIgcIlQyoCAlhOmrSw6pZScBNkctg8r0W0=
-github.com/alecthomas/kong v0.2.17/go.mod h1:ka3VZ8GZNPXv9Ov+j4YNLkI8mTuhXyr/0ktSlqIydQQ=
+github.com/alecthomas/kong v0.2.19 h1:qBDfByO5XgWUXyNB4D6OOhGh5Z1eNOwWayDPQJFNWdc=
+github.com/alecthomas/kong v0.2.19/go.mod h1:ka3VZ8GZNPXv9Ov+j4YNLkI8mTuhXyr/0ktSlqIydQQ=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/alecthomas/units v0.0.0-20190717042225-c3de453c63f4/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d/go.mod h1:rBZYJk541a8SKzHPHnH3zbiI+7dagKZ0cgpgrD7Fyho=
-github.com/alecthomas/units v0.0.0-20210208195552-ff826a37aa15 h1:AUNCr9CiJuwrRYS3XieqF+Z9B9gNxo/eANAJCF2eiN4=
-github.com/alecthomas/units v0.0.0-20210208195552-ff826a37aa15/go.mod h1:OMCwj8VM1Kc9e19TLln2VL61YJF0x1XFtfdL4JdbSyE=
+github.com/alecthomas/units v0.0.0-20210927113745-59d0afb8317a h1:E/8AP5dFtMhl5KPJz66Kt9G0n+7Sn41Fy1wv9/jHOrc=
+github.com/alecthomas/units v0.0.0-20210927113745-59d0afb8317a/go.mod h1:OMCwj8VM1Kc9e19TLln2VL61YJF0x1XFtfdL4JdbSyE=
 github.com/andres-erbsen/clock v0.0.0-20160526145045-9e14626cd129/go.mod h1:rFgpPQZYZ8vdbc+48xibu8ALc3yeyd64IhHS+PU6Yyg=
 github.com/andybalholm/cascadia v1.1.0/go.mod h1:GsXiBklL0woXo1j/WYWtSYYC4ouU9PqHO0sqidkEA4Y=
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 h1:0CwZNZbxp69SHPdPJAN/hZIm0C4OItdklCFmMRWYpio=
@@ -169,8 +169,8 @@ github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7V
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
 github.com/k0kubun/colorstring v0.0.0-20150214042306-9440f1994b88/go.mod h1:3w7q1U84EfirKl04SVQ/s7nPm1ZPhiXd34z40TNz36k=
 github.com/k0kubun/pp v2.4.0+incompatible/go.mod h1:GWse8YhT0p8pT4ir3ZgBbfZild3tgzSScAn6HmfYukg=
-github.com/kentik/patricia v0.0.0-20201202224819-f9447a6e25f1 h1:D7qhJP3R49ZjUzpzKQ6B2H3lgejPs6DTO5gRomhhOpE=
-github.com/kentik/patricia v0.0.0-20201202224819-f9447a6e25f1/go.mod h1:2OfLA+0esiUJpwMjrH39pEk79cb8MvGTBS9YlZpejJ4=
+github.com/kentik/patricia v0.0.0-20210909164817-21603333b70e h1:1wAVuGu1c+lsdaOPQN+9xoP9+gaIMJV6H0ehGc+K5iA=
+github.com/kentik/patricia v0.0.0-20210909164817-21603333b70e/go.mod h1:2OfLA+0esiUJpwMjrH39pEk79cb8MvGTBS9YlZpejJ4=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
@@ -193,10 +193,12 @@ github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lN
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
-github.com/panjf2000/ants/v2 v2.4.6 h1:drmj9mcygn2gawZ155dRbo+NfXEfAssjZNU1qoIb4gQ=
-github.com/panjf2000/ants/v2 v2.4.6/go.mod h1:f6F0NZVFsGCp5A7QW/Zj/m92atWwOkY0OIhFxRNFr4A=
-github.com/pelletier/go-toml v1.9.3 h1:zeC5b1GviRUyKYd6OJPvBU/mcVDVoL1OhT17FCt5dSQ=
-github.com/pelletier/go-toml v1.9.3/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=
+github.com/panjf2000/ants/v2 v2.4.7 h1:MZnw2JRyTJxFwtaMtUJcwE618wKD04POWk2gwwP4E2M=
+github.com/panjf2000/ants/v2 v2.4.7/go.mod h1:f6F0NZVFsGCp5A7QW/Zj/m92atWwOkY0OIhFxRNFr4A=
+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 v1.9.4 h1:tjENF6MfZAg8e4ZmZTeWaWiT2vXtsoO6+iuOjFhECwM=
+github.com/pelletier/go-toml v1.9.4/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
@@ -217,8 +219,8 @@ github.com/prometheus/client_model v0.2.0/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6T
 github.com/prometheus/common v0.4.1/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/common v0.10.0/go.mod h1:Tlit/dnDKsSWFlCLTWaA1cyBgKHSMdTB80sz/V91rCo=
 github.com/prometheus/common v0.26.0/go.mod h1:M7rCNAaPfAosfx8veZJCuw84e35h3Cfd9VFqTh1DIvc=
-github.com/prometheus/common v0.30.0 h1:JEkYlQnpzrzQFxi6gnukFPdQ+ac82oRhzMcIduJu/Ug=
-github.com/prometheus/common v0.30.0/go.mod h1:vu+V0TpY+O6vW9J44gczi3Ap/oXXR10b+M/gUGO4Hls=
+github.com/prometheus/common v0.32.1 h1:hWIdL3N2HoUx3B8j3YN9mWor0qhY/NlEKZEaXxuIRh4=
+github.com/prometheus/common v0.32.1/go.mod h1:vu+V0TpY+O6vW9J44gczi3Ap/oXXR10b+M/gUGO4Hls=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/procfs v0.1.3/go.mod h1:lV6e/gmhEcM9IjHGsFOCxxuZ+z1YqCvr4OA4YeYWdaU=
@@ -229,8 +231,8 @@ github.com/quasilyte/go-ruleguard/dsl v0.3.2/go.mod h1:KeCP03KrjuSO0H1kTuZQCWlQP
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rogpeppe/go-internal v1.8.0/go.mod h1:WmiCO8CzOY8rg0OYDC4/i/2WRWAB6poM+XZ2dLUbcbE=
 github.com/rs/xid v1.3.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
-github.com/rs/zerolog v1.24.0 h1:76ivFxmVSRs1u2wUwJVg5VZDYQgeH1JpoS6ndgr9Wy8=
-github.com/rs/zerolog v1.24.0/go.mod h1:7KHcEGe0QZPOm2IE4Kpb5rTh6n1h2hIgS5OOnu1rUaI=
+github.com/rs/zerolog v1.26.0 h1:ORM4ibhEZeTeQlCojCK2kPz1ogAY4bGs4tD+SaAdGaE=
+github.com/rs/zerolog v1.26.0/go.mod h1:yBiM87lvSqX8h0Ww4sdzNSkVYZ8dL2xjZJG1lAuGZEo=
 github.com/sebdah/goldie/v2 v2.5.3/go.mod h1:oZ9fp0+se1eapSRjfYbsV/0Hqhbuu3bJVvKI/NNtssI=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/sergi/go-diff v1.1.0/go.mod h1:STckp+ISIX8hZLjrqAeVduY0gWCT9IjLuqbuNXdaHfM=
@@ -250,12 +252,18 @@ github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81P
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/txthinking/runnergroup v0.0.0-20210608031112-152c7c4432bf h1:7PflaKRtU4np/epFxRXlFhlzLXZzKFrH5/I4so5Ove0=
+github.com/txthinking/runnergroup v0.0.0-20210608031112-152c7c4432bf/go.mod h1:CLUSJbazqETbaR+i0YAhXBICV9TrKH93pziccMhmhpM=
+github.com/txthinking/socks5 v0.0.0-20211121111206-e03c1217a50b h1:6J/38A0Xmdnjacfie0Udams7OP/GdoExyTipKwuQWjY=
+github.com/txthinking/socks5 v0.0.0-20211121111206-e03c1217a50b/go.mod h1:7NloQcrxaZYKURWph5HLxVDlIwMHJXCPkeWPtpftsIg=
+github.com/txthinking/x v0.0.0-20210326105829-476fab902fbe h1:gMWxZxBFRAXqoGkwkYlPX2zvyyKNWJpxOxCrjqJkm5A=
+github.com/txthinking/x v0.0.0-20210326105829-476fab902fbe/go.mod h1:WgqbSEmUYSjEV3B1qmee/PpP2NYEz4bL9/+mF1ma+s4=
 github.com/tylertreat/BoomFilters v0.0.0-20210315201527-1a82519a3e43 h1:QEePdg0ty2r0t1+qwfZmQ4OOl/MB2UXIeJSpIZv56lg=
 github.com/tylertreat/BoomFilters v0.0.0-20210315201527-1a82519a3e43/go.mod h1:OYRfF6eb5wY9VRFkXJH8FFBi3plw2v+giaIu7P054pM=
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
-github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
+github.com/yuin/goldmark v1.4.0/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 go.opencensus.io v0.22.0/go.mod h1:+kGneAE2xo2IficOXnaByMWTGM9T73dGwxeWcUqIpI8=
 go.opencensus.io v0.22.2/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
@@ -277,8 +285,8 @@ golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529/go.mod h1:yigFU9vqHzYiE8U
 golang.org/x/crypto v0.0.0-20190605123033-f99c8df09eb5/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 h1:/UOmuWzQfxxo9UtlXMwuQU8CMgg1eZXqTRwkSQJWKOI=
-golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/crypto v0.0.0-20211202192323-5770296d904e h1:MUP6MR3rJ7Gk9LEia0LP2ytiH6MuCfs7qYz+47jGdD8=
+golang.org/x/crypto v0.0.0-20211202192323-5770296d904e/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190510132918-efd6b22b2522/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
@@ -342,11 +350,10 @@ golang.org/x/net v0.0.0-20200625001655-4c5254603344/go.mod h1:/O7V0waA8r7cgGh81R
 golang.org/x/net v0.0.0-20200707034311-ab3426394381/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20200822124328-c89045814202/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
-golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
 golang.org/x/net v0.0.0-20210525063256-abc453219eb5/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
-golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985 h1:4CSI6oo7cOjJKajidEljs9h+uP0rRZBPPPhcCbj5mw8=
-golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/net v0.0.0-20210805182204-aaa1db679c0d/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2 h1:CIJ76btIcR3eFI5EgSo6k1qKw9KJexJuRLI9G7Hp5wE=
+golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -400,13 +407,12 @@ golang.org/x/sys v0.0.0-20200803210538-64077c9b5642/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210603081109-ebe580a85c40/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c h1:F1jZWGFhYfh0Ci55sIpILtKKK8p3i2/krTr0H1rg74I=
-golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20210809222454-d867a43fc93e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20211124211545-fe61309f8881 h1:TyHqChC80pFkXWraUUf6RuB5IqFdQieMLwwCJokV2pc=
+golang.org/x/sys v0.0.0-20211124211545-fe61309f8881/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -460,8 +466,8 @@ golang.org/x/tools v0.0.0-20200729194436-6467de6f59a7/go.mod h1:njjCfa9FT2d7l9Bc
 golang.org/x/tools v0.0.0-20200804011535-6c149bb5ef0d/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
 golang.org/x/tools v0.0.0-20200820010801-b793a1359eac/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
 golang.org/x/tools v0.0.0-20200825202427-b303f430e36d/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
-golang.org/x/tools v0.1.5 h1:ouewzE6p+/VEB31YYnTbEJdi8pFqKp4P4n85vwo3DHA=
-golang.org/x/tools v0.1.5/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
+golang.org/x/tools v0.1.7 h1:6j8CgantCy3yc8JGBqkDLMKWqZ0RDU2g1HVgacojGWQ=
+golang.org/x/tools v0.1.7/go.mod h1:LGqMHiF4EqQNHR1JncWGqT5BVaXmza+X+BDGol+dOxo=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

internal/cli/access.go

@@ -13,6 +13,7 @@ import (
 	"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"
@@ -106,7 +107,7 @@ func (a *Access) Run(cli *CLI, version string) error {
 }
 
 func (a *Access) getIP(ntw mtglib.Network, protocol string) net.IP {
-	client := ntw.MakeHTTPClient(func(ctx context.Context, network, address string) (net.Conn, error) {
+	client := ntw.MakeHTTPClient(func(ctx context.Context, network, address string) (essentials.Conn, error) {
 		return ntw.DialContext(ctx, protocol, address) // nolint: wrapcheck
 	})
 

internal/cli/run_proxy.go

@@ -38,10 +38,9 @@ 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()
-	bufferSize := conf.TCPBuffer.Get(network.DefaultBufferSize)
 	userAgent := "mtg/" + version
 
-	baseDialer, err := network.NewDefaultDialer(tcpTimeout, int(bufferSize))
+	baseDialer, err := network.NewDefaultDialer(tcpTimeout, 0)
 	if err != nil {
 		return nil, fmt.Errorf("cannot build a default dialer: %w", err)
 	}
@@ -86,15 +85,15 @@ func makeAntiReplayCache(conf *config.Config) mtglib.AntiReplayCache {
 	)
 }
 
-func makeIPBlocklist(conf *config.Config, logger mtglib.Logger, ntw mtglib.Network) (mtglib.IPBlocklist, error) {
-	if !conf.Defense.Blocklist.Enabled.Get(false) {
+func makeIPBlocklist(conf config.ListConfig, logger mtglib.Logger, ntw mtglib.Network) (mtglib.IPBlocklist, error) {
+	if !conf.Enabled.Get(false) {
 		return ipblocklist.NewNoop(), nil
 	}
 
 	remoteURLs := []string{}
 	localFiles := []string{}
 
-	for _, v := range conf.Defense.Blocklist.URLs {
+	for _, v := range conf.URLs {
 		if v.IsRemote() {
 			remoteURLs = append(remoteURLs, v.String())
 		} else {
@@ -104,7 +103,7 @@ func makeIPBlocklist(conf *config.Config, logger mtglib.Logger, ntw mtglib.Netwo
 
 	firehol, err := ipblocklist.NewFirehol(logger.Named("ipblockist"),
 		ntw,
-		conf.Defense.Blocklist.DownloadConcurrency.Get(1),
+		conf.DownloadConcurrency.Get(1),
 		remoteURLs,
 		localFiles)
 	if err != nil {
@@ -153,21 +152,32 @@ func makeEventStream(conf *config.Config, logger mtglib.Logger) (mtglib.EventStr
 	return events.NewNoopStream(), nil
 }
 
-func runProxy(conf *config.Config, version string) error {
+func runProxy(conf *config.Config, version string) error { // nolint: funlen
 	logger := makeLogger(conf)
 
-	logger.BindStr("configuration", conf.String()).Debug("configuration")
+	logger.BindJSON("configuration", conf.String()).Debug("configuration")
 
 	ntw, err := makeNetwork(conf, version)
 	if err != nil {
 		return fmt.Errorf("cannot build network: %w", err)
 	}
 
-	blocklist, err := makeIPBlocklist(conf, logger, ntw)
+	blocklist, err := makeIPBlocklist(conf.Defense.Blocklist, logger, ntw)
 	if err != nil {
 		return fmt.Errorf("cannot build ip blocklist: %w", err)
 	}
 
+	var whitelist mtglib.IPBlocklist
+
+	if conf.Defense.Allowlist.Enabled.Get(false) {
+		whlist, err := makeIPBlocklist(conf.Defense.Allowlist, logger, ntw)
+		if err != nil {
+			return fmt.Errorf("cannot build ip blocklist: %w", err)
+		}
+
+		whitelist = whlist
+	}
+
 	eventStream, err := makeEventStream(conf, logger)
 	if err != nil {
 		return fmt.Errorf("cannot build event stream: %w", err)
@@ -178,12 +188,15 @@ func runProxy(conf *config.Config, version string) error {
 		Network:         ntw,
 		AntiReplayCache: makeAntiReplayCache(conf),
 		IPBlocklist:     blocklist,
+		IPWhitelist:     whitelist,
 		EventStream:     eventStream,
 
 		Secret:             conf.Secret,
-		BufferSize:         conf.TCPBuffer.Get(mtglib.DefaultBufferSize),
 		DomainFrontingPort: conf.DomainFrontingPort.Get(mtglib.DefaultDomainFrontingPort),
 		PreferIP:           conf.PreferIP.Get(mtglib.DefaultPreferIP),
+
+		AllowFallbackOnUnknownDC: conf.AllowFallbackOnUnknownDC.Get(false),
+		TolerateTimeSkewness:     conf.TolerateTimeSkewness.Value,
 	}
 
 	proxy, err := mtglib.NewProxy(opts)
@@ -191,7 +204,7 @@ func runProxy(conf *config.Config, version string) error {
 		return fmt.Errorf("cannot create a proxy: %w", err)
 	}
 
-	listener, err := utils.NewListener(conf.BindTo.Get(""), int(opts.BufferSize))
+	listener, err := utils.NewListener(conf.BindTo.Get(""), 0)
 	if err != nil {
 		return fmt.Errorf("cannot start proxy: %w", err)
 	}

internal/cli/simple_run.go

@@ -15,7 +15,7 @@ type SimpleRun struct {
 
 	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='Size of TCP buffer to use.'"`                                             // 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='9.9.9.9',help='IP address of DNS-over-HTTP to use.'"`                                    // nolint: lll
@@ -38,10 +38,6 @@ func (s *SimpleRun) Run(cli *CLI, version string) error { // nolint: cyclop
 		return fmt.Errorf("incorrect concurrency: %w", err)
 	}
 
-	if err := conf.TCPBuffer.Set(s.TCPBuffer); err != nil {
-		return fmt.Errorf("incorrect tcp-buffer: %w", err)
-	}
-
 	if err := conf.PreferIP.Set(s.PreferIP); err != nil {
 		return fmt.Errorf("incorrect prefer-ip: %w", err)
 	}
@@ -71,6 +67,7 @@ func (s *SimpleRun) Run(cli *CLI, version string) error { // nolint: cyclop
 	}
 
 	conf.Debug.Value = s.Debug
+	conf.AllowFallbackOnUnknownDC.Value = true
 	conf.Defense.AntiReplay.Enabled.Value = true
 
 	if err := conf.Validate(); err != nil {

internal/config/config.go

@@ -8,27 +8,36 @@ import (
 	"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"`
-	Secret               mtglib.Secret   `json:"secret"`
-	BindTo               TypeHostPort    `json:"bindTo"`
-	TCPBuffer            TypeBytes       `json:"tcpBuffer"`
-	PreferIP             TypePreferIP    `json:"preferIp"`
-	DomainFrontingPort   TypePort        `json:"domainFrontingPort"`
-	TolerateTimeSkewness TypeDuration    `json:"tolerateTimeSkewness"`
-	Concurrency          TypeConcurrency `json:"concurrency"`
-	Defense              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 {
-			Enabled   TypeBool      `json:"enabled"`
+			Optional
+
 			MaxSize   TypeBytes     `json:"maxSize"`
 			ErrorRate TypeErrorRate `json:"errorRate"`
 		} `json:"antiReplay"`
-		Blocklist struct {
-			Enabled             TypeBool           `json:"enabled"`
-			DownloadConcurrency TypeConcurrency    `json:"downloadConcurrency"`
-			URLs                []TypeBlocklistURI `json:"urls"`
-			UpdateEach          TypeDuration       `json:"updateEach"`
-		} `json:"blocklist"`
+		Blocklist ListConfig `json:"blocklist"`
+		Allowlist ListConfig `json:"allowlist"`
 	} `json:"defense"`
 	Network struct {
 		Timeout struct {
@@ -41,13 +50,15 @@ type Config struct {
 	} `json:"network"`
 	Stats struct {
 		StatsD struct {
-			Enabled      TypeBool            `json:"enabled"`
+			Optional
+
 			Address      TypeHostPort        `json:"address"`
 			MetricPrefix TypeMetricPrefix    `json:"metricPrefix"`
 			TagFormat    TypeStatsdTagFormat `json:"tagFormat"`
 		} `json:"statsd"`
 		Prometheus struct {
-			Enabled      TypeBool         `json:"enabled"`
+			Optional
+
 			BindTo       TypeHostPort     `json:"bindTo"`
 			HTTPPath     TypeHTTPPath     `json:"httpPath"`
 			MetricPrefix TypeMetricPrefix `json:"metricPrefix"`

internal/config/parse.go

@@ -9,15 +9,15 @@ import (
 )
 
 type tomlConfig struct {
-	Debug                bool   `toml:"debug" json:"debug,omitempty"`
-	Secret               string `toml:"secret" json:"secret"`
-	BindTo               string `toml:"bind-to" json:"bindTo"`
-	TCPBuffer            string `toml:"tcp-buffer" json:"tcpBuffer,omitempty"`
-	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 {
+	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"`
@@ -29,6 +29,12 @@ type tomlConfig struct {
 			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 {

internal/testlib/mtglib_network_mock.go

@@ -2,9 +2,9 @@ package testlib
 
 import (
 	"context"
-	"net"
 	"net/http"
 
+	"github.com/9seconds/mtg/v2/essentials"
 	"github.com/stretchr/testify/mock"
 )
 
@@ -12,19 +12,19 @@ type MtglibNetworkMock struct {
 	mock.Mock
 }
 
-func (m *MtglibNetworkMock) Dial(network, address string) (net.Conn, error) {
+func (m *MtglibNetworkMock) Dial(network, address string) (essentials.Conn, error) {
 	args := m.Called(network, address)
 
-	return args.Get(0).(net.Conn), args.Error(1) // nolint: wrapcheck
+	return args.Get(0).(essentials.Conn), args.Error(1) // nolint: wrapcheck
 }
 
-func (m *MtglibNetworkMock) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+func (m *MtglibNetworkMock) DialContext(ctx context.Context, network, address string) (essentials.Conn, error) {
 	args := m.Called(ctx, network, address)
 
-	return args.Get(0).(net.Conn), args.Error(1) // nolint: wrapcheck
+	return args.Get(0).(essentials.Conn), args.Error(1) // nolint: wrapcheck
 }
 
 func (m *MtglibNetworkMock) MakeHTTPClient(dialFunc func(ctx context.Context,
-	network, address string) (net.Conn, error)) *http.Client {
+	network, address string) (essentials.Conn, error)) *http.Client {
 	return m.Called(dialFunc).Get(0).(*http.Client)
 }

internal/testlib/net_conn_mock.go

@@ -7,42 +7,50 @@ import (
 	"github.com/stretchr/testify/mock"
 )
 
-type NetConnMock struct {
+type EssentialsConnMock struct {
 	mock.Mock
 }
 
-func (n *NetConnMock) Read(b []byte) (int, error) {
+func (n *EssentialsConnMock) Read(b []byte) (int, error) {
 	args := n.Called(b)
 
 	return args.Int(0), args.Error(1)
 }
 
-func (n *NetConnMock) Write(b []byte) (int, error) {
+func (n *EssentialsConnMock) Write(b []byte) (int, error) {
 	args := n.Called(b)
 
 	return args.Int(0), args.Error(1)
 }
 
-func (n *NetConnMock) Close() error {
+func (n *EssentialsConnMock) Close() error {
 	return n.Called().Error(0) // nolint: wrapcheck
 }
 
-func (n *NetConnMock) LocalAddr() net.Addr {
+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)
 }
 
-func (n *NetConnMock) RemoteAddr() net.Addr {
+func (n *EssentialsConnMock) RemoteAddr() net.Addr {
 	return n.Called().Get(0).(net.Addr)
 }
 
-func (n *NetConnMock) SetDeadline(t time.Time) error {
+func (n *EssentialsConnMock) SetDeadline(t time.Time) error {
 	return n.Called(t).Error(0) // nolint: wrapcheck
 }
 
-func (n *NetConnMock) SetReadDeadline(t time.Time) error {
+func (n *EssentialsConnMock) SetReadDeadline(t time.Time) error {
 	return n.Called(t).Error(0) // nolint: wrapcheck
 }
 
-func (n *NetConnMock) SetWriteDeadline(t time.Time) error {
+func (n *EssentialsConnMock) SetWriteDeadline(t time.Time) error {
 	return n.Called(t).Error(0) // nolint: wrapcheck
 }

internal/utils/net_listener.go

@@ -9,8 +9,6 @@ import (
 
 type Listener struct {
 	net.Listener
-
-	bufferSize int
 }
 
 func (l Listener) Accept() (net.Conn, error) {
@@ -19,7 +17,7 @@ func (l Listener) Accept() (net.Conn, error) {
 		return nil, err // nolint: wrapcheck
 	}
 
-	if err := network.SetClientSocketOptions(conn, l.bufferSize); err != nil {
+	if err := network.SetClientSocketOptions(conn, 0); err != nil {
 		conn.Close()
 
 		return nil, fmt.Errorf("cannot set TCP options: %w", err)
@@ -35,7 +33,6 @@ func NewListener(bindTo string, bufferSize int) (net.Listener, error) {
 	}
 
 	return Listener{
-		Listener:   base,
-		bufferSize: bufferSize,
+		Listener: base,
 	}, nil
 }

internal/utils/rlimit.go

@@ -1,3 +1,4 @@
+//go:build !windows
 // +build !windows
 
 package utils

internal/utils/rlimit_windows.go

@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package utils

internal/utils/root_context.go

@@ -1,3 +1,4 @@
+//go:build !windows
 // +build !windows
 
 package utils

internal/utils/root_context_windows.go

@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package utils

ipblocklist/files/http.go

@@ -0,0 +1,63 @@
+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()
+		}
+
+		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
+}
+
+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()
+
+	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 +1,14 @@
+package files
+
+import (
+	"context"
+	"errors"
+	"io"
+)
+
+var ErrBadHTTPClient = errors.New("incorrect http client")
+
+type File interface {
+	Open(context.Context) (io.ReadCloser, error)
+	String() string
+}

ipblocklist/files/local.go

@@ -0,0 +1,30 @@
+package files
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+)
+
+type localFile struct {
+	path string
+}
+
+func (l localFile) Open(ctx context.Context) (io.ReadCloser, error) {
+	return os.Open(l.path) // nolint: wrapcheck
+}
+
+func (l localFile) String() string {
+	return l.path
+}
+
+func NewLocal(path string) (File, error) {
+	if stat, err := os.Stat(path); os.IsNotExist(err) || stat.IsDir() || stat.Mode().Perm()&0o400 == 0 {
+		return nil, fmt.Errorf("%s is not a readable file", path)
+	}
+
+	return localFile{
+		path: path,
+	}, nil
+}

ipblocklist/files/local_test.go

@@ -0,0 +1,55 @@
+package files_test
+
+import (
+	"context"
+	"io"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/9seconds/mtg/v2/ipblocklist/files"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type LocalTestSuite struct {
+	suite.Suite
+}
+
+func (suite *LocalTestSuite) getLocalFile(name string) string {
+	return filepath.Join("testdata", name)
+}
+
+func (suite *LocalTestSuite) TestIncorrect() {
+	names := []string{
+		"absent",
+		"directory",
+	}
+
+	for _, v := range names {
+		value := v
+
+		suite.T().Run(v, func(t *testing.T) {
+			_, err := files.NewLocal(suite.getLocalFile(value))
+			assert.Error(t, err)
+		})
+	}
+}
+
+func (suite *LocalTestSuite) TestOk() {
+	file, err := files.NewLocal(suite.getLocalFile("readable"))
+	suite.NoError(err)
+
+	reader, err := file.Open(context.Background())
+	suite.NoError(err)
+
+	data, err := io.ReadAll(reader)
+	suite.NoError(err)
+
+	suite.Equal("Hooray!", strings.TrimSpace(string(data)))
+}
+
+func TestLocal(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &LocalTestSuite{})
+}

ipblocklist/files/testdata/readable

@@ -0,0 +1 @@
+Hooray!

ipblocklist/firehol.go

@@ -4,16 +4,13 @@ import (
 	"bufio"
 	"context"
 	"fmt"
-	"io"
 	"net"
-	"net/http"
-	"net/url"
-	"os"
 	"regexp"
 	"strings"
 	"sync"
 	"time"
 
+	"github.com/9seconds/mtg/v2/ipblocklist/files"
 	"github.com/9seconds/mtg/v2/mtglib"
 	"github.com/kentik/patricia"
 	"github.com/kentik/patricia/bool_tree"
@@ -41,20 +38,16 @@ var fireholRegexpComment = regexp.MustCompile(`\s*#.*?$`)
 //     127.0.0.1   # you can specify an IP
 //     10.0.0.0/8  # or cidr
 type Firehol struct {
-	ctx       context.Context
-	ctxCancel context.CancelFunc
-	logger    mtglib.Logger
+	ctx         context.Context
+	ctxCancel   context.CancelFunc
+	logger      mtglib.Logger
+	updateMutex sync.RWMutex
 
-	rwMutex sync.RWMutex
+	blocklists []files.File
 
-	remoteURLs []string
-	localFiles []string
-
-	httpClient *http.Client
 	workerPool *ants.Pool
-
-	treeV4 *bool_tree.TreeV4
-	treeV6 *bool_tree.TreeV6
+	treeV4     *bool_tree.TreeV4
+	treeV6     *bool_tree.TreeV6
 }
 
 // Shutdown stop a background update process.
@@ -68,8 +61,8 @@ func (f *Firehol) Contains(ip net.IP) bool {
 		return true
 	}
 
-	f.rwMutex.RLock()
-	defer f.rwMutex.RUnlock()
+	f.updateMutex.RLock()
+	defer f.updateMutex.RUnlock()
 
 	if ip4 := ip.To4(); ip4 != nil {
 		return f.containsIPv4(ip4)
@@ -98,22 +91,14 @@ func (f *Firehol) Run(updateEach time.Duration) {
 		}
 	}()
 
-	if err := f.update(); err != nil {
-		f.logger.WarningError("cannot update blocklist", err)
-	} else {
-		f.logger.Info("blocklist was updated")
-	}
+	f.update()
 
 	for {
 		select {
 		case <-f.ctx.Done():
 			return
 		case <-ticker.C:
-			if err := f.update(); err != nil {
-				f.logger.WarningError("cannot update blocklist", err)
-			} else {
-				f.logger.Info("blocklist was updated")
-			}
+			f.update()
 		}
 	}
 }
@@ -121,7 +106,7 @@ func (f *Firehol) Run(updateEach time.Duration) {
 func (f *Firehol) containsIPv4(addr net.IP) bool {
 	ip := patricia.NewIPv4AddressFromBytes(addr, 32) // nolint: gomnd
 
-	if ok, _, err := f.treeV4.FindDeepestTag(ip); ok && err == nil {
+	if ok, _ := f.treeV4.FindDeepestTag(ip); ok {
 		return true
 	}
 
@@ -131,128 +116,60 @@ func (f *Firehol) containsIPv4(addr net.IP) bool {
 func (f *Firehol) containsIPv6(addr net.IP) bool {
 	ip := patricia.NewIPv6Address(addr, 128) // nolint: gomnd
 
-	if ok, _, err := f.treeV6.FindDeepestTag(ip); ok && err == nil {
+	if ok, _ := f.treeV6.FindDeepestTag(ip); ok {
 		return true
 	}
 
 	return false
 }
 
-func (f *Firehol) update() error { // nolint: funlen, cyclop
+func (f *Firehol) update() {
 	ctx, cancel := context.WithCancel(f.ctx)
 	defer cancel()
 
 	wg := &sync.WaitGroup{}
-	wg.Add(len(f.remoteURLs) + len(f.localFiles))
+	wg.Add(len(f.blocklists))
 
 	treeMutex := &sync.Mutex{}
 	v4tree := bool_tree.NewTreeV4()
 	v6tree := bool_tree.NewTreeV6()
 
-	errorChan := make(chan error, 1)
-	defer close(errorChan)
-
-	for _, v := range f.localFiles {
-		go func(filename string) {
+	for _, v := range f.blocklists {
+		go func(file files.File) {
 			defer wg.Done()
 
-			if err := f.updateLocalFile(ctx, filename, treeMutex, v4tree, v6tree); err != nil {
-				cancel()
-				f.logger.BindStr("filename", filename).WarningError("cannot update", err)
+			logger := f.logger.BindStr("filename", file.String())
 
-				select {
-				case errorChan <- err:
-				default:
-				}
+			fileContent, err := file.Open(ctx)
+			if err != nil {
+				logger.WarningError("update has failed", err)
+
+				return
+			}
+
+			defer fileContent.Close()
+
+			if err := f.updateFromFile(treeMutex, v4tree, v6tree, bufio.NewScanner(fileContent)); err != nil {
+				logger.WarningError("update has failed", err)
 			}
 		}(v)
 	}
 
-	for _, v := range f.remoteURLs {
-		value := v
-
-		f.workerPool.Submit(func() { // nolint: errcheck
-			defer wg.Done()
-
-			if err := f.updateRemoteURL(ctx, value, treeMutex, v4tree, v6tree); err != nil {
-				cancel()
-				f.logger.BindStr("url", value).WarningError("cannot update", err)
-
-				select {
-				case errorChan <- err:
-				default:
-				}
-			}
-		})
-	}
-
 	wg.Wait()
 
-	select {
-	case err := <-errorChan:
-		return fmt.Errorf("cannot update trees: %w", err)
-	default:
-	}
-
-	f.rwMutex.Lock()
-	defer f.rwMutex.Unlock()
+	f.updateMutex.Lock()
+	defer f.updateMutex.Unlock()
 
 	f.treeV4 = v4tree
 	f.treeV6 = v6tree
 
-	return nil
+	f.logger.Info("blocklist was updated")
 }
 
-func (f *Firehol) updateLocalFile(ctx context.Context, filename string,
-	mutex sync.Locker,
-	v4tree *bool_tree.TreeV4, v6tree *bool_tree.TreeV6) error {
-	filefp, err := os.Open(filename)
-	if err != nil {
-		return fmt.Errorf("cannot open file: %w", err)
-	}
-
-	go func(ctx context.Context, closer io.Closer) {
-		<-ctx.Done()
-		closer.Close()
-	}(ctx, filefp)
-
-	defer filefp.Close()
-
-	return f.updateTrees(mutex, filefp, v4tree, v6tree)
-}
-
-func (f *Firehol) updateRemoteURL(ctx context.Context, url string,
-	mutex sync.Locker,
-	v4tree *bool_tree.TreeV4, v6tree *bool_tree.TreeV6) error {
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
-	if err != nil {
-		return fmt.Errorf("cannot build a request: %w", err)
-	}
-
-	resp, err := f.httpClient.Do(req) // nolint: bodyclose
-	if err != nil {
-		return fmt.Errorf("cannot request a remote URL %s: %w", url, err)
-	}
-
-	go func(ctx context.Context, closer io.Closer) {
-		<-ctx.Done()
-		closer.Close()
-	}(ctx, resp.Body)
-
-	defer func(rc io.ReadCloser) {
-		io.Copy(io.Discard, rc) // nolint: errcheck
-		rc.Close()
-	}(resp.Body)
-
-	return f.updateTrees(mutex, resp.Body, v4tree, v6tree)
-}
-
-func (f *Firehol) updateTrees(mutex sync.Locker,
-	reader io.Reader,
+func (f *Firehol) updateFromFile(mutex sync.Locker,
 	v4tree *bool_tree.TreeV4,
-	v6tree *bool_tree.TreeV6) error {
-	scanner := bufio.NewScanner(reader)
-
+	v6tree *bool_tree.TreeV6,
+	scanner *bufio.Scanner) error {
 	for scanner.Scan() {
 		text := scanner.Text()
 		text = fireholRegexpComment.ReplaceAllLiteralString(text, "")
@@ -267,13 +184,11 @@ func (f *Firehol) updateTrees(mutex sync.Locker,
 			return fmt.Errorf("cannot parse a line: %w", err)
 		}
 
-		if err := f.updateAddToTrees(ip, cidr, mutex, v4tree, v6tree); err != nil {
-			return fmt.Errorf("cannot add a node to the tree: %w", err)
-		}
+		f.updateAddToTrees(ip, cidr, mutex, v4tree, v6tree)
 	}
 
 	if scanner.Err() != nil {
-		return fmt.Errorf("cannot parse a response: %w", scanner.Err())
+		return fmt.Errorf("cannot parse a file: %w", scanner.Err())
 	}
 
 	return nil
@@ -302,25 +217,15 @@ func (f *Firehol) updateParseLine(text string) (net.IP, uint, error) {
 
 func (f *Firehol) updateAddToTrees(ip net.IP, cidr uint,
 	mutex sync.Locker,
-	v4tree *bool_tree.TreeV4, v6tree *bool_tree.TreeV6) error {
+	v4tree *bool_tree.TreeV4, v6tree *bool_tree.TreeV6) {
 	mutex.Lock()
 	defer mutex.Unlock()
 
 	if ip.To4() != nil {
-		addr := patricia.NewIPv4AddressFromBytes(ip, cidr)
-
-		if _, _, err := v4tree.Set(addr, true); err != nil {
-			return err // nolint: wrapcheck
-		}
+		v4tree.Set(patricia.NewIPv4AddressFromBytes(ip, cidr), true)
 	} else {
-		addr := patricia.NewIPv6Address(ip, cidr)
-
-		if _, _, err := v6tree.Set(addr, true); err != nil {
-			return err // nolint: wrapcheck
-		}
+		v6tree.Set(patricia.NewIPv6Address(ip, cidr), true)
 	}
-
-	return nil
 }
 
 // NewFirehol creates a new instance of FireHOL IP blocklist.
@@ -329,27 +234,36 @@ func (f *Firehol) updateAddToTrees(ip net.IP, cidr uint,
 // when it is necessary.
 func NewFirehol(logger mtglib.Logger, network mtglib.Network,
 	downloadConcurrency uint,
-	remoteURLs []string,
+	urls []string,
 	localFiles []string) (*Firehol, error) {
-	for _, v := range remoteURLs {
-		parsed, err := url.Parse(v)
-		if err != nil {
-			return nil, fmt.Errorf("incorrect url %s: %w", v, err)
-		}
-
-		switch parsed.Scheme {
-		case "http", "https":
-		default:
-			return nil, fmt.Errorf("unsupported url %s", v)
-		}
-	}
+	blocklists := []files.File{}
 
 	for _, v := range localFiles {
-		if stat, err := os.Stat(v); os.IsNotExist(err) || stat.IsDir() || stat.Mode().Perm()&0o400 == 0 {
-			return nil, fmt.Errorf("%s is not a readable file", v)
+		file, err := files.NewLocal(v)
+		if err != nil {
+			return nil, fmt.Errorf("cannot create a local file %s: %w", v, err)
 		}
+
+		blocklists = append(blocklists, file)
 	}
 
+	httpClient := network.MakeHTTPClient(nil)
+
+	for _, v := range urls {
+		file, err := files.NewHTTP(httpClient, v)
+		if err != nil {
+			return nil, fmt.Errorf("cannot create a HTTP file %s: %w", v, err)
+		}
+
+		blocklists = append(blocklists, file)
+	}
+
+	return NewFireholFromFiles(logger, downloadConcurrency, blocklists)
+}
+
+func NewFireholFromFiles(logger mtglib.Logger,
+	downloadConcurrency uint,
+	blocklists []files.File) (*Firehol, error) {
 	if downloadConcurrency == 0 {
 		downloadConcurrency = DefaultFireholDownloadConcurrency
 	}
@@ -361,11 +275,9 @@ func NewFirehol(logger mtglib.Logger, network mtglib.Network,
 		ctx:        ctx,
 		ctxCancel:  cancel,
 		logger:     logger.Named("firehol"),
-		httpClient: network.MakeHTTPClient(nil),
 		treeV4:     bool_tree.NewTreeV4(),
 		treeV6:     bool_tree.NewTreeV6(),
 		workerPool: workerPool,
-		remoteURLs: remoteURLs,
-		localFiles: localFiles,
+		blocklists: blocklists,
 	}, nil
 }

logger/noop.go

@@ -7,6 +7,7 @@ type noopLogger struct{}
 func (n noopLogger) Named(_ string) mtglib.Logger          { return n }
 func (n noopLogger) BindInt(_ string, _ int) mtglib.Logger { return n }
 func (n noopLogger) BindStr(_, _ string) mtglib.Logger     { return n }
+func (n noopLogger) BindJSON(_, _ string) mtglib.Logger    { return n }
 func (n noopLogger) Printf(_ string, _ ...interface{})     {}
 func (n noopLogger) Info(_ string)                         {}
 func (n noopLogger) Warning(_ string)                      {}

logger/zerolog.go

@@ -15,6 +15,7 @@ const (
 	zeroLogContextVarTypeUnknown zeroLogContextVarType = iota
 	zeroLogContextVarTypeStr
 	zeroLogContextVarTypeInt
+	zeroLogContextVarTypeJSON
 )
 
 type zeroLogContext struct {
@@ -66,6 +67,17 @@ func (z *zeroLogContext) BindStr(name, value string) mtglib.Logger {
 	}
 }
 
+func (z *zeroLogContext) BindJSON(name, value string) mtglib.Logger {
+	return &zeroLogContext{
+		name:       z.name,
+		log:        z.log,
+		ctxVarType: zeroLogContextVarTypeJSON,
+		ctxVarName: name,
+		ctxVarStr:  value,
+		parent:     z,
+	}
+}
+
 func (z *zeroLogContext) Printf(format string, args ...interface{}) {
 	z.Debug(fmt.Sprintf(format, args...))
 }
@@ -110,6 +122,8 @@ func (z *zeroLogContext) attachCtx(evt *zerolog.Event) {
 		evt.Str(z.ctxVarName, z.ctxVarStr)
 	case zeroLogContextVarTypeInt:
 		evt.Int(z.ctxVarName, z.ctxVarInt)
+	case zeroLogContextVarTypeJSON:
+		evt.RawJSON(z.ctxVarName, []byte(z.ctxVarStr))
 	case zeroLogContextVarTypeUnknown:
 	}
 }

mtglib/conns.go

@@ -4,12 +4,13 @@ import (
 	"bytes"
 	"context"
 	"io"
-	"net"
 	"sync"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
 type connTraffic struct {
-	net.Conn
+	essentials.Conn
 
 	streamID string
 	stream   EventStream
@@ -37,7 +38,7 @@ func (c connTraffic) Write(b []byte) (int, error) {
 }
 
 type connRewind struct {
-	net.Conn
+	essentials.Conn
 
 	active io.Reader
 	buf    bytes.Buffer
@@ -58,7 +59,7 @@ func (c *connRewind) Rewind() {
 	c.active = io.MultiReader(&c.buf, c.Conn)
 }
 
-func newConnRewind(conn net.Conn) *connRewind {
+func newConnRewind(conn essentials.Conn) *connRewind {
 	rv := &connRewind{
 		Conn: conn,
 	}

mtglib/conns_internal_test.go

@@ -14,7 +14,7 @@ import (
 )
 
 type ConnRewindBaseConn struct {
-	testlib.NetConnMock
+	testlib.EssentialsConnMock
 
 	readBuffer bytes.Buffer
 }
@@ -29,13 +29,13 @@ type ConnTrafficTestSuite struct {
 	suite.Suite
 
 	eventStreamMock *EventStreamMock
-	connMock        *testlib.NetConnMock
+	connMock        *testlib.EssentialsConnMock
 	conn            io.ReadWriter
 }
 
 func (suite *ConnTrafficTestSuite) SetupTest() {
 	suite.eventStreamMock = &EventStreamMock{}
-	suite.connMock = &testlib.NetConnMock{}
+	suite.connMock = &testlib.EssentialsConnMock{}
 	suite.conn = connTraffic{
 		Conn:     suite.connMock,
 		streamID: "CONNID",

mtglib/init.go

@@ -23,6 +23,8 @@ import (
 	"net"
 	"net/http"
 	"time"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
 var (
@@ -61,6 +63,8 @@ const (
 	DefaultConcurrency = 4096
 
 	// DefaultBufferSize is a default size of a copy buffer.
+	//
+	// Deprecated: this setting no longer makes any effect.
 	DefaultBufferSize = 16 * 1024 // 16 kib
 
 	// DefaultDomainFrontingPort is a default port (HTTPS) to connect to in
@@ -114,16 +118,16 @@ const (
 // 3. Doing HTTP requests (for example, for FireHOL ipblocklist).
 type Network interface {
 	// Dial establishes context-free TCP connections.
-	Dial(network, address string) (net.Conn, error)
+	Dial(network, address string) (essentials.Conn, error)
 
 	// DialContext dials using a context. This is a preferrable
 	// way of establishing TCP connections.
-	DialContext(ctx context.Context, network, address string) (net.Conn, error)
+	DialContext(ctx context.Context, network, address string) (essentials.Conn, error)
 
 	// MakeHTTPClient build an HTTP client with given dial function. If
 	// nothing is provided, then DialContext of this interface is going
 	// to be used.
-	MakeHTTPClient(func(ctx context.Context, network, address string) (net.Conn, error)) *http.Client
+	MakeHTTPClient(func(ctx context.Context, network, address string) (essentials.Conn, error)) *http.Client
 }
 
 // AntiReplayCache is an interface that is used to detect replay attacks
@@ -245,6 +249,9 @@ type Logger interface {
 	// BindStr binds new string parameter to a new logger instance.
 	BindStr(name, value string) Logger
 
+	// BindJSON binds a new JSON-encoded string to a new logger instance.
+	BindJSON(name, value string) Logger
+
 	// Printf is to support log.Logger behavior.
 	Printf(format string, args ...interface{})
 

mtglib/init_internal_test.go

@@ -11,6 +11,7 @@ type NoopLogger struct{}
 func (n NoopLogger) Named(_ string) Logger             { return n }
 func (n NoopLogger) BindInt(_ string, _ int) Logger    { return n }
 func (n NoopLogger) BindStr(_, _ string) Logger        { return n }
+func (n NoopLogger) BindJSON(_, _ string) Logger       { return n }
 func (n NoopLogger) Printf(_ string, _ ...interface{}) {}
 func (n NoopLogger) Info(_ string)                     {}
 func (n NoopLogger) Warning(_ string)                  {}

mtglib/internal/faketls/conn.go

@@ -4,13 +4,13 @@ import (
 	"bytes"
 	"fmt"
 	"math/rand"
-	"net"
 
+	"github.com/9seconds/mtg/v2/essentials"
 	"github.com/9seconds/mtg/v2/mtglib/internal/faketls/record"
 )
 
 type Conn struct {
-	net.Conn
+	essentials.Conn
 
 	readBuffer bytes.Buffer
 }

mtglib/internal/faketls/conn_test.go

@@ -15,7 +15,7 @@ import (
 )
 
 type ConnMock struct {
-	testlib.NetConnMock
+	testlib.EssentialsConnMock
 
 	readBuffer  bytes.Buffer
 	writeBuffer bytes.Buffer

mtglib/internal/obfuscated2/client_handshake_test.go

@@ -42,7 +42,7 @@ func (suite *ClientHandshakeTestSuite) TestOk() {
 			writeData := make([]byte, len(snapshot.Encrypted.Text.data))
 			readData := make([]byte, len(snapshot.Decrypted.Text.data))
 
-			connMock := &testlib.NetConnMock{}
+			connMock := &testlib.EssentialsConnMock{}
 			connMock.On("Read", mock.Anything).
 				Once().
 				Return(len(snapshot.Decrypted.Text.data), nil).

mtglib/internal/obfuscated2/conn.go

@@ -2,11 +2,12 @@ package obfuscated2
 
 import (
 	"crypto/cipher"
-	"net"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
 type Conn struct {
-	net.Conn
+	essentials.Conn
 
 	Encryptor cipher.Stream
 	Decryptor cipher.Stream

mtglib/internal/obfuscated2/server_handshake_test.go

@@ -16,7 +16,7 @@ import (
 type ServerHandshakeTestSuite struct {
 	suite.Suite
 
-	connMock  *testlib.NetConnMock
+	connMock  *testlib.EssentialsConnMock
 	proxyConn obfuscated2.Conn
 	encryptor cipher.Stream
 	decryptor cipher.Stream
@@ -24,7 +24,7 @@ type ServerHandshakeTestSuite struct {
 
 func (suite *ServerHandshakeTestSuite) SetupTest() {
 	buf := &bytes.Buffer{}
-	suite.connMock = &testlib.NetConnMock{}
+	suite.connMock = &testlib.EssentialsConnMock{}
 
 	encryptor, decryptor, err := obfuscated2.ServerHandshake(buf)
 	suite.NoError(err)

mtglib/internal/relay/conn.go

@@ -1,19 +0,0 @@
-package relay
-
-import (
-	"fmt"
-	"net"
-	"time"
-)
-
-type conn struct {
-	net.Conn
-}
-
-func (c conn) Read(p []byte) (int, error) {
-	if err := c.SetReadDeadline(time.Now().Add(getTimeout())); err != nil {
-		return 0, fmt.Errorf("cannot set read deadline: %w", err)
-	}
-
-	return c.Conn.Read(p) // nolint: wrapcheck
-}

mtglib/internal/relay/init.go

@@ -1,12 +1,7 @@
 package relay
 
-import "time"
-
 const (
-	ConnectionTimeToLiveMin = 2 * time.Minute
-	ConnectionTimeToLiveMax = 10 * time.Minute
-	TimeoutMin              = 20 * time.Second
-	TimeoutMax              = time.Minute
+	copyBufferSize = 64 * 1024
 )
 
 type Logger interface {

mtglib/internal/relay/pools.go

@@ -2,31 +2,18 @@ package relay
 
 import "sync"
 
-type eastWest struct {
-	east []byte
-	west []byte
-}
-
-var eastWestPool = sync.Pool{
+var copyBufferPool = sync.Pool{
 	New: func() interface{} {
-		return &eastWest{}
+		rv := make([]byte, copyBufferSize)
+
+		return &rv
 	},
 }
 
-func acquireEastWest(bufferSize int) *eastWest {
-	wanted := eastWestPool.Get().(*eastWest) // nolint: forcetypeassert
-
-	if len(wanted.east) != bufferSize {
-		wanted.east = make([]byte, bufferSize)
-	}
-
-	if len(wanted.west) != bufferSize {
-		wanted.west = make([]byte, bufferSize)
-	}
-
-	return wanted
+func acquireCopyBuffer() *[]byte {
+	return copyBufferPool.Get().(*[]byte)
 }
 
-func releaseEastWest(ew *eastWest) {
-	eastWestPool.Put(ew)
+func releaseCopyBuffer(buf *[]byte) {
+	copyBufferPool.Put(buf)
 }

mtglib/internal/relay/relay.go

@@ -2,17 +2,17 @@ package relay
 
 import (
 	"context"
+	"errors"
 	"io"
-	"net"
-	"sync"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
-func Relay(ctx context.Context, log Logger, bufferSize int,
-	telegramConn net.Conn, clientConn io.ReadWriteCloser) {
+func Relay(ctx context.Context, log Logger, telegramConn, clientConn essentials.Conn) {
 	defer telegramConn.Close()
 	defer clientConn.Close()
 
-	ctx, cancel := context.WithTimeout(ctx, getConnectionTimeToLive())
+	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
 	go func() {
@@ -21,30 +21,34 @@ func Relay(ctx context.Context, log Logger, bufferSize int,
 		clientConn.Close()
 	}()
 
-	buffers := acquireEastWest(bufferSize)
-	defer releaseEastWest(buffers)
+	closeChan := make(chan struct{})
 
-	telegramConn = conn{
-		Conn: telegramConn,
-	}
+	go func() {
+		defer close(closeChan)
 
-	wg := &sync.WaitGroup{}
-	wg.Add(2) // nolint: gomnd
+		pump(log, telegramConn, clientConn, "client -> telegram")
+	}()
 
-	go pump(log, telegramConn, clientConn, wg, buffers.east, "east -> west")
+	pump(log, clientConn, telegramConn, "telegram -> client")
 
-	pump(log, clientConn, telegramConn, wg, buffers.west, "west -> east")
-
-	wg.Wait()
+	<-closeChan
 }
 
-func pump(log Logger, src io.ReadCloser, dst io.WriteCloser, wg *sync.WaitGroup,
-	buf []byte, direction string) {
-	defer wg.Done()
-	defer src.Close()
-	defer dst.Close()
+func pump(log Logger, src, dst essentials.Conn, direction string) {
+	defer src.CloseRead()  // nolint: errcheck
+	defer dst.CloseWrite() // nolint: errcheck
 
-	if n, err := io.CopyBuffer(dst, src, buf); err != nil {
-		log.Printf("cannot pump %s (written %d bytes): %w", direction, n, err)
+	copyBuffer := acquireCopyBuffer()
+	defer releaseCopyBuffer(copyBuffer)
+
+	n, err := io.CopyBuffer(src, dst, *copyBuffer)
+
+	switch {
+	case err == nil:
+		log.Printf("%s has been finished", direction)
+	case errors.Is(err, io.EOF):
+		log.Printf("%s has been finished because of EOF. Written %d bytes", direction, n)
+	default:
+		log.Printf("%s has been finished (written %d bytes): %v", direction, n, err)
 	}
 }

mtglib/internal/relay/relay_test.go

@@ -17,8 +17,8 @@ type RelayTestSuite struct {
 	loggerMock       relay.Logger
 	ctx              context.Context
 	ctxCancel        context.CancelFunc
-	telegramConnMock *testlib.NetConnMock
-	clientConnMock   *testlib.NetConnMock
+	telegramConnMock *testlib.EssentialsConnMock
+	clientConnMock   *testlib.EssentialsConnMock
 }
 
 func (suite *RelayTestSuite) SetupTest() {
@@ -26,8 +26,8 @@ func (suite *RelayTestSuite) SetupTest() {
 	suite.ctx = ctx
 	suite.ctxCancel = cancel
 	suite.loggerMock = &loggerMock{}
-	suite.telegramConnMock = &testlib.NetConnMock{}
-	suite.clientConnMock = &testlib.NetConnMock{}
+	suite.telegramConnMock = &testlib.EssentialsConnMock{}
+	suite.clientConnMock = &testlib.EssentialsConnMock{}
 }
 
 func (suite *RelayTestSuite) TearDownTest() {
@@ -37,17 +37,19 @@ func (suite *RelayTestSuite) TearDownTest() {
 }
 
 func (suite *RelayTestSuite) TestExit() {
-	suite.telegramConnMock.On("SetReadDeadline", mock.Anything).Return(nil)
 	suite.telegramConnMock.On("Close").Return(nil)
+	suite.telegramConnMock.On("CloseRead").Return(nil).Once()
+	suite.telegramConnMock.On("CloseWrite").Return(nil).Once()
 	suite.telegramConnMock.On("Read", mock.Anything).Return(10, io.EOF).Once()
 	suite.telegramConnMock.On("Write", mock.Anything).Return(10, io.EOF).Maybe()
 
 	suite.clientConnMock.On("Read", mock.Anything).Return(0, io.EOF).Once()
 	suite.clientConnMock.On("Write", mock.Anything).Return(10, io.EOF).Maybe()
 	suite.clientConnMock.On("Close").Return(nil)
+	suite.clientConnMock.On("CloseRead").Return(nil).Once()
+	suite.clientConnMock.On("CloseWrite").Return(nil).Once()
 
-	relay.Relay(suite.ctx, suite.loggerMock, 1024,
-		suite.telegramConnMock, suite.clientConnMock)
+	relay.Relay(suite.ctx, suite.loggerMock, suite.telegramConnMock, suite.clientConnMock)
 }
 
 func TestRelay(t *testing.T) {

mtglib/internal/relay/timeouts.go

@@ -1,22 +0,0 @@
-package relay
-
-import (
-	"math/rand"
-	"time"
-)
-
-func getConnectionTimeToLive() time.Duration {
-	return getTime(ConnectionTimeToLiveMin, ConnectionTimeToLiveMax)
-}
-
-func getTimeout() time.Duration {
-	return getTime(TimeoutMin, TimeoutMax)
-}
-
-func getTime(minDuration, maxDuration time.Duration) time.Duration {
-	minDurationInSeconds := int(minDuration.Seconds())
-	maxDurationInSeconds := int(maxDuration.Seconds())
-	number := minDurationInSeconds + rand.Intn(maxDurationInSeconds-minDurationInSeconds)
-
-	return time.Duration(number) * time.Second
-}

mtglib/internal/relay/timeouts_internal_test.go

@@ -1,37 +0,0 @@
-package relay
-
-import (
-	"fmt"
-	"testing"
-
-	"github.com/stretchr/testify/suite"
-)
-
-type TimeoutsTestSuite struct {
-	suite.Suite
-}
-
-func (suite *TimeoutsTestSuite) TestGetConnectionTimeToLive() {
-	for i := 0; i < 100; i++ {
-		value := getConnectionTimeToLive()
-		message := fmt.Sprintf("generated value is %v", value)
-
-		suite.GreaterOrEqual(value, ConnectionTimeToLiveMin, message)
-		suite.LessOrEqual(value, ConnectionTimeToLiveMax, message)
-	}
-}
-
-func (suite *TimeoutsTestSuite) TestGetTimeout() {
-	for i := 0; i < 100; i++ {
-		value := getTimeout()
-		message := fmt.Sprintf("generated value is %v", value)
-
-		suite.GreaterOrEqual(value, TimeoutMin, message)
-		suite.LessOrEqual(value, TimeoutMax, message)
-	}
-}
-
-func TestTimeouts(t *testing.T) {
-	t.Parallel()
-	suite.Run(t, &TimeoutsTestSuite{})
-}

mtglib/internal/telegram/address_pool.go

@@ -7,6 +7,14 @@ type addressPool struct {
 	v6 [][]tgAddr
 }
 
+func (a addressPool) isValidDC(dc int) bool {
+	return dc > 0 && dc <= len(a.v4) && dc <= len(a.v6)
+}
+
+func (a addressPool) getRandomDC() int {
+	return 1 + rand.Intn(len(a.v4))
+}
+
 func (a addressPool) getV4(dc int) []tgAddr {
 	return a.get(a.v4, dc-1)
 }

mtglib/internal/telegram/init.go

@@ -2,7 +2,8 @@ package telegram
 
 import (
 	"context"
-	"net"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
 type preferIP uint8
@@ -82,5 +83,5 @@ var (
 )
 
 type Dialer interface {
-	DialContext(ctx context.Context, network, address string) (net.Conn, error)
+	DialContext(ctx context.Context, network, address string) (essentials.Conn, error)
 }

mtglib/internal/telegram/telegram.go

@@ -3,8 +3,9 @@ package telegram
 import (
 	"context"
 	"fmt"
-	"net"
 	"strings"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
 type Telegram struct {
@@ -13,7 +14,7 @@ type Telegram struct {
 	pool     addressPool
 }
 
-func (t Telegram) Dial(ctx context.Context, dc int) (net.Conn, error) {
+func (t Telegram) Dial(ctx context.Context, dc int) (essentials.Conn, error) {
 	var addresses []tgAddr
 
 	switch t.preferIP {
@@ -28,7 +29,7 @@ func (t Telegram) Dial(ctx context.Context, dc int) (net.Conn, error) {
 	}
 
 	var (
-		conn net.Conn
+		conn essentials.Conn
 		err  error
 	)
 
@@ -42,6 +43,14 @@ func (t Telegram) Dial(ctx context.Context, dc int) (net.Conn, error) {
 	return nil, fmt.Errorf("cannot dial to %d dc: %w", dc, err)
 }
 
+func (t Telegram) IsKnownDC(dc int) bool {
+	return t.pool.isValidDC(dc)
+}
+
+func (t Telegram) GetFallbackDC() int {
+	return t.pool.getRandomDC()
+}
+
 func New(dialer Dialer, ipPreference string, useTestDCs bool) (*Telegram, error) {
 	var pref preferIP
 

mtglib/internal/telegram/telegram_internal_test.go

@@ -44,6 +44,7 @@ func (suite *TelegramTestSuite) TestUnknownDC() {
 		suite.T().Run(strconv.Itoa(value), func(t *testing.T) {
 			_, err := suite.t.Dial(context.Background(), value)
 			assert.Error(t, err)
+			assert.False(t, suite.t.IsKnownDC(value))
 		})
 	}
 }
@@ -71,6 +72,7 @@ func (suite *TelegramTestSuite) TestDialToCorrectIPs() {
 
 			_, err := suite.t.Dial(context.Background(), idx)
 			assert.True(t, errors.Is(err, io.EOF))
+			assert.True(t, suite.t.IsKnownDC(idx))
 		})
 	}
 }
@@ -135,6 +137,22 @@ func (suite *TelegramTestSuite) TestUnknownPreferIP() {
 	suite.Error(err)
 }
 
+func (suite *TelegramTestSuite) TestFallbackDC() {
+	dcs := make([]int, 10)
+
+	for i := 0; i < len(dcs); i++ {
+		dcs[i] = suite.t.GetFallbackDC()
+	}
+
+	for _, v := range dcs {
+		value := v
+
+		suite.T().Run(strconv.Itoa(value), func(t *testing.T) {
+			assert.True(t, suite.t.IsKnownDC(value))
+		})
+	}
+}
+
 func TestTelegram(t *testing.T) {
 	t.Parallel()
 	suite.Run(t, &TelegramTestSuite{})

mtglib/proxy.go

@@ -9,6 +9,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/9seconds/mtg/v2/essentials"
 	"github.com/9seconds/mtg/v2/mtglib/internal/faketls"
 	"github.com/9seconds/mtg/v2/mtglib/internal/faketls/record"
 	"github.com/9seconds/mtg/v2/mtglib/internal/obfuscated2"
@@ -23,16 +24,17 @@ type Proxy struct {
 	ctxCancel       context.CancelFunc
 	streamWaitGroup sync.WaitGroup
 
-	tolerateTimeSkewness time.Duration
-	bufferSize           int
-	domainFrontingPort   int
-	workerPool           *ants.PoolWithFunc
-	telegram             *telegram.Telegram
+	allowFallbackOnUnknownDC bool
+	tolerateTimeSkewness     time.Duration
+	domainFrontingPort       int
+	workerPool               *ants.PoolWithFunc
+	telegram                 *telegram.Telegram
 
 	secret          Secret
 	network         Network
 	antiReplayCache AntiReplayCache
-	ipBlocklist     IPBlocklist
+	blocklist       IPBlocklist
+	whitelist       IPBlocklist
 	eventStream     EventStream
 	logger          Logger
 }
@@ -44,7 +46,7 @@ func (p *Proxy) DomainFrontingAddress() string {
 
 // ServeConn serves a connection. We do not check IP blocklist and
 // concurrency limit here.
-func (p *Proxy) ServeConn(conn net.Conn) {
+func (p *Proxy) ServeConn(conn essentials.Conn) {
 	p.streamWaitGroup.Add(1)
 	defer p.streamWaitGroup.Done()
 
@@ -83,14 +85,13 @@ func (p *Proxy) ServeConn(conn net.Conn) {
 	relay.Relay(
 		ctx,
 		ctx.logger.Named("relay"),
-		p.bufferSize,
 		ctx.telegramConn,
 		ctx.clientConn,
 	)
 }
 
 // Serve starts a proxy on a given listener.
-func (p *Proxy) Serve(listener net.Listener) error {
+func (p *Proxy) Serve(listener net.Listener) error { // nolint: cyclop
 	p.streamWaitGroup.Add(1)
 	defer p.streamWaitGroup.Done()
 
@@ -108,7 +109,15 @@ func (p *Proxy) Serve(listener net.Listener) error {
 		ipAddr := conn.RemoteAddr().(*net.TCPAddr).IP
 		logger := p.logger.BindStr("ip", ipAddr.String())
 
-		if p.ipBlocklist.Contains(ipAddr) {
+		if p.whitelist != nil && !p.whitelist.Contains(ipAddr) {
+			conn.Close()
+			logger.Info("ip was rejected by whitelist")
+			p.eventStream.Send(p.ctx, NewEventIPBlocklisted(ipAddr))
+
+			continue
+		}
+
+		if p.blocklist.Contains(ipAddr) {
 			conn.Close()
 			logger.Info("ip was blacklisted")
 			p.eventStream.Send(p.ctx, NewEventIPBlocklisted(ipAddr))
@@ -207,7 +216,16 @@ func (p *Proxy) doObfuscated2Handshake(ctx *streamContext) error {
 }
 
 func (p *Proxy) doTelegramCall(ctx *streamContext) error {
-	conn, err := p.telegram.Dial(ctx, ctx.dc)
+	dc := ctx.dc
+
+	if p.allowFallbackOnUnknownDC && !p.telegram.IsKnownDC(dc) {
+		dc = p.telegram.GetFallbackDC()
+		ctx.logger = ctx.logger.BindInt("fallback_dc", dc)
+
+		ctx.logger.Warning("unknown DC, fallbacks")
+	}
+
+	conn, err := p.telegram.Dial(ctx, dc)
 	if err != nil {
 		return fmt.Errorf("cannot dial to Telegram: %w", err)
 	}
@@ -257,7 +275,6 @@ func (p *Proxy) doDomainFronting(ctx *streamContext, conn *connRewind) {
 	relay.Relay(
 		ctx,
 		ctx.logger.Named("domain-fronting"),
-		p.bufferSize,
 		frontConn,
 		conn,
 	)
@@ -276,23 +293,24 @@ func NewProxy(opts ProxyOpts) (*Proxy, error) {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	proxy := &Proxy{
-		ctx:                  ctx,
-		ctxCancel:            cancel,
-		secret:               opts.Secret,
-		network:              opts.Network,
-		antiReplayCache:      opts.AntiReplayCache,
-		ipBlocklist:          opts.IPBlocklist,
-		eventStream:          opts.EventStream,
-		logger:               opts.getLogger("proxy"),
-		domainFrontingPort:   opts.getDomainFrontingPort(),
-		tolerateTimeSkewness: opts.getTolerateTimeSkewness(),
-		bufferSize:           opts.getBufferSize(),
-		telegram:             tg,
+		ctx:                      ctx,
+		ctxCancel:                cancel,
+		secret:                   opts.Secret,
+		network:                  opts.Network,
+		antiReplayCache:          opts.AntiReplayCache,
+		blocklist:                opts.IPBlocklist,
+		whitelist:                opts.IPWhitelist,
+		eventStream:              opts.EventStream,
+		logger:                   opts.getLogger("proxy"),
+		domainFrontingPort:       opts.getDomainFrontingPort(),
+		tolerateTimeSkewness:     opts.getTolerateTimeSkewness(),
+		allowFallbackOnUnknownDC: opts.AllowFallbackOnUnknownDC,
+		telegram:                 tg,
 	}
 
 	pool, err := ants.NewPoolWithFunc(opts.getConcurrency(),
 		func(arg interface{}) {
-			proxy.ServeConn(arg.(net.Conn))
+			proxy.ServeConn(arg.(essentials.Conn))
 		},
 		ants.WithLogger(opts.getLogger("ants")),
 		ants.WithNonblocking(true))

mtglib/proxy_opts.go

@@ -28,6 +28,11 @@ type ProxyOpts struct {
 	// This is a mandatory setting.
 	IPBlocklist IPBlocklist
 
+	// IPWhitelist defines a whitelist of IPs to allow to use proxy.
+	//
+	// This is an optional setting, ignored by default (no restrictions).
+	IPWhitelist IPBlocklist
+
 	// EventStream defines an instance of event stream.
 	//
 	// This ia a mandatory setting.
@@ -45,6 +50,8 @@ type ProxyOpts struct {
 	// buffers: to and from.
 	//
 	// This is an optional setting.
+	//
+	// Deprecated: this setting is no longer makes any effect.
 	BufferSize uint
 
 	// Concurrency is a size of the worker pool for connection management.
@@ -90,6 +97,16 @@ type ProxyOpts struct {
 	// This is an optional setting.
 	DomainFrontingPort uint
 
+	// AllowFallbackOnUnknownDC defines how proxy behaves if unknown DC was
+	// requested. If this setting is set to false, then such connection
+	// will be rejected. Otherwise, proxy will chose any DC.
+	//
+	// Telegram is designed in a way that any DC can serve any request,
+	// the problem is a latency.
+	//
+	// This is an optional setting.
+	AllowFallbackOnUnknownDC bool
+
 	// UseTestDCs defines if we have to connect to production or to staging
 	// DCs of Telegram.
 	//
@@ -119,14 +136,6 @@ func (p ProxyOpts) valid() error {
 	return nil
 }
 
-func (p ProxyOpts) getBufferSize() int {
-	if p.BufferSize < 1 {
-		return DefaultBufferSize
-	}
-
-	return int(p.BufferSize)
-}
-
 func (p ProxyOpts) getConcurrency() int {
 	if p.Concurrency == 0 {
 		return DefaultConcurrency

mtglib/stream_context.go

@@ -6,13 +6,15 @@ import (
 	"encoding/base64"
 	"net"
 	"time"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
 type streamContext struct {
 	ctx          context.Context
 	ctxCancel    context.CancelFunc
-	clientConn   net.Conn
-	telegramConn net.Conn
+	clientConn   essentials.Conn
+	telegramConn essentials.Conn
 	streamID     string
 	dc           int
 	logger       Logger
@@ -50,7 +52,7 @@ func (s *streamContext) ClientIP() net.IP {
 	return s.clientConn.RemoteAddr().(*net.TCPAddr).IP
 }
 
-func newStreamContext(ctx context.Context, logger Logger, clientConn net.Conn) *streamContext {
+func newStreamContext(ctx context.Context, logger Logger, clientConn essentials.Conn) *streamContext {
 	connIDBytes := make([]byte, ConnectionIDBytesLength)
 
 	if _, err := rand.Read(connIDBytes); err != nil {

mtglib/stream_context_internal_test.go

@@ -12,7 +12,7 @@ import (
 type StreamContextTestSuite struct {
 	suite.Suite
 
-	connMock  *testlib.NetConnMock
+	connMock  *testlib.EssentialsConnMock
 	logger    NoopLogger
 	ctx       *streamContext
 	ctxCancel context.CancelFunc
@@ -27,7 +27,7 @@ func (suite *StreamContextTestSuite) SetupTest() {
 	ctx = context.WithValue(ctx, "key", "value") // nolint: golint, revive, staticcheck
 
 	suite.ctxCancel = cancel
-	suite.connMock = &testlib.NetConnMock{}
+	suite.connMock = &testlib.EssentialsConnMock{}
 
 	addr := &net.TCPAddr{
 		IP:   net.ParseIP("10.0.0.10"),
@@ -73,7 +73,7 @@ func (suite *StreamContextTestSuite) TestClientIP() {
 func (suite *StreamContextTestSuite) TestClose() {
 	suite.connMock.On("Close").Once().Return(nil)
 
-	tgConnMock := &testlib.NetConnMock{}
+	tgConnMock := &testlib.EssentialsConnMock{}
 	tgConnMock.On("Close").Once().Return(nil)
 
 	suite.ctx.telegramConn = tgConnMock

network/circuit_breaker.go

@@ -2,9 +2,10 @@ package network
 
 import (
 	"context"
-	"net"
 	"sync/atomic"
 	"time"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
 const (
@@ -30,12 +31,12 @@ type circuitBreakerDialer struct {
 	resetFailuresTimeout time.Duration
 }
 
-func (c *circuitBreakerDialer) Dial(network, address string) (net.Conn, error) {
+func (c *circuitBreakerDialer) Dial(network, address string) (essentials.Conn, error) {
 	return c.DialContext(context.Background(), network, address)
 }
 
 func (c *circuitBreakerDialer) DialContext(ctx context.Context,
-	network, address string) (net.Conn, error) {
+	network, address string) (essentials.Conn, error) {
 	switch atomic.LoadUint32(&c.state) {
 	case circuitBreakerStateClosed:
 		return c.doClosed(ctx, network, address)
@@ -47,7 +48,7 @@ func (c *circuitBreakerDialer) DialContext(ctx context.Context,
 }
 
 func (c *circuitBreakerDialer) doClosed(ctx context.Context,
-	network, address string) (net.Conn, error) {
+	network, address string) (essentials.Conn, error) {
 	conn, err := c.Dialer.DialContext(ctx, network, address)
 
 	select {
@@ -78,7 +79,8 @@ func (c *circuitBreakerDialer) doClosed(ctx context.Context,
 	return conn, err // nolint: wrapcheck
 }
 
-func (c *circuitBreakerDialer) doHalfOpened(ctx context.Context, network, address string) (net.Conn, error) {
+func (c *circuitBreakerDialer) doHalfOpened(ctx context.Context,
+	network, address string) (essentials.Conn, error) {
 	if !atomic.CompareAndSwapUint32(&c.halfOpenAttempts, 0, 1) {
 		return nil, ErrCircuitBreakerOpened
 	}

network/circuit_breaker_internal_test.go

@@ -21,7 +21,7 @@ type CircuitBreakerTestSuite struct {
 	mutex          sync.Mutex
 	ctx            context.Context
 	ctxCancel      context.CancelFunc
-	connMock       *testlib.NetConnMock
+	connMock       *testlib.EssentialsConnMock
 	baseDialerMock *DialerMock
 }
 
@@ -29,7 +29,7 @@ func (suite *CircuitBreakerTestSuite) SetupTest() {
 	suite.mutex = sync.Mutex{}
 	suite.ctx, suite.ctxCancel = context.WithCancel(context.Background())
 	suite.baseDialerMock = &DialerMock{}
-	suite.connMock = &testlib.NetConnMock{}
+	suite.connMock = &testlib.EssentialsConnMock{}
 	suite.d = newCircuitBreakerDialer(suite.baseDialerMock,
 		3, 100*time.Millisecond, 50*time.Millisecond)
 }

network/default.go

@@ -5,19 +5,19 @@ import (
 	"fmt"
 	"net"
 	"time"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
 type defaultDialer struct {
 	net.Dialer
-
-	bufferSize int
 }
 
-func (d *defaultDialer) Dial(network, address string) (net.Conn, error) {
+func (d *defaultDialer) Dial(network, address string) (essentials.Conn, error) {
 	return d.DialContext(context.Background(), network, address)
 }
 
-func (d *defaultDialer) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+func (d *defaultDialer) DialContext(ctx context.Context, network, address string) (essentials.Conn, error) {
 	switch network {
 	case "tcp", "tcp4", "tcp6": // nolint: goconst
 	default:
@@ -30,13 +30,13 @@ func (d *defaultDialer) DialContext(ctx context.Context, network, address string
 	}
 
 	// we do not need to call to end user. End users call us.
-	if err := SetServerSocketOptions(conn, d.bufferSize); err != nil {
+	if err := SetServerSocketOptions(conn, 0); err != nil {
 		conn.Close()
 
 		return nil, fmt.Errorf("cannot set socket options: %w", err)
 	}
 
-	return conn, nil
+	return conn.(essentials.Conn), nil
 }
 
 // NewDefaultDialer build a new dialer which dials bypassing proxies
@@ -44,26 +44,20 @@ func (d *defaultDialer) DialContext(ctx context.Context, network, address string
 //
 // The most default one you can imagine. But it has tunes TCP
 // connections and setups SO_REUSEPORT.
+//
+// bufferSize is deprecated and ignored. It is kept here for backward
+// compatibility.
 func NewDefaultDialer(timeout time.Duration, bufferSize int) (Dialer, error) {
 	switch {
 	case timeout < 0:
 		return nil, fmt.Errorf("timeout %v should be positive number", timeout)
-	case bufferSize < 0:
-		return nil, fmt.Errorf("buffer size %d should be positive number", bufferSize)
-	}
-
-	if timeout == 0 {
+	case timeout == 0:
 		timeout = DefaultTimeout
 	}
 
-	if bufferSize == 0 {
-		bufferSize = DefaultBufferSize
-	}
-
 	return &defaultDialer{
 		Dialer: net.Dialer{
 			Timeout: timeout,
 		},
-		bufferSize: bufferSize,
 	}, nil
 }

network/default_test.go

@@ -30,11 +30,6 @@ func (suite *DefaultDialerTestSuite) TestNegativeTimeout() {
 	suite.Error(err)
 }
 
-func (suite *DefaultDialerTestSuite) TestNegativeBufferSize() {
-	_, err := network.NewDefaultDialer(0, -1)
-	suite.Error(err)
-}
-
 func (suite *DefaultDialerTestSuite) TestUnsupportedProtocol() {
 	_, err := suite.d.DialContext(context.Background(),
 		"udp",

network/dns_resolver.go

@@ -1,6 +1,8 @@
 package network
 
 import (
+	"fmt"
+	"net"
 	"net/http"
 	"sync"
 	"time"
@@ -83,8 +85,13 @@ func (d *dnsResolver) LookupAAAA(hostname string) []string {
 	return ips
 }
 
-func newDNSResolver(hostname string, httpClient *http.Client) *dnsResolver {
-	return &dnsResolver{
+func newDNSResolver(hostname string, httpClient *http.Client) (ret *dnsResolver) {
+	if net.ParseIP(hostname).To4() == nil {
+		// the hostname is an IPv6 address
+		hostname = fmt.Sprintf("[%s]", hostname)
+	}
+
+	ret = &dnsResolver{
 		resolver: doh.Resolver{
 			Host:       hostname,
 			Class:      doh.IN,
@@ -92,4 +99,6 @@ func newDNSResolver(hostname string, httpClient *http.Client) *dnsResolver {
 		},
 		cache: map[string]dnsResolverCacheEntry{},
 	}
+
+	return
 }

network/init.go

@@ -20,8 +20,9 @@ package network
 import (
 	"context"
 	"errors"
-	"net"
 	"time"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
 const (
@@ -33,10 +34,16 @@ const (
 	// request.
 	DefaultHTTPTimeout = 10 * time.Second
 
+	// Deprecated:
+	//
 	// DefaultBufferSize defines a TCP buffer size. Both read and write, so
 	// for real size, please multiply this number by 2.
 	DefaultBufferSize = 16 * 1024 // 16 kib
 
+	// DefaultTCPKeepAlivePeriod defines a time period between 2
+	// consequitive probes.
+	DefaultTCPKeepAlivePeriod = 10 * time.Second
+
 	// ProxyDialerOpenThreshold is used for load balancing SOCKS5 dialer
 	// only.
 	//
@@ -89,6 +96,6 @@ var (
 // Dialer defines an interface which is required to bootstrap a network
 // instance from.
 type Dialer interface {
-	Dial(network, address string) (net.Conn, error)
-	DialContext(ctx context.Context, network, address string) (net.Conn, error)
+	Dial(network, address string) (essentials.Conn, error)
+	DialContext(ctx context.Context, network, address string) (essentials.Conn, error)
 }

network/init_internal_test.go

@@ -2,8 +2,8 @@ package network
 
 import (
 	"context"
-	"net"
 
+	"github.com/9seconds/mtg/v2/essentials"
 	"github.com/stretchr/testify/mock"
 )
 
@@ -11,14 +11,14 @@ type DialerMock struct {
 	mock.Mock
 }
 
-func (d *DialerMock) Dial(network, address string) (net.Conn, error) {
+func (d *DialerMock) Dial(network, address string) (essentials.Conn, error) {
 	args := d.Called(network, address)
 
-	return args.Get(0).(net.Conn), args.Error(1) // nolint: wrapcheck
+	return args.Get(0).(essentials.Conn), args.Error(1) // nolint: wrapcheck
 }
 
-func (d *DialerMock) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+func (d *DialerMock) DialContext(ctx context.Context, network, address string) (essentials.Conn, error) {
 	args := d.Called(ctx, network, address)
 
-	return args.Get(0).(net.Conn), args.Error(1) // nolint: wrapcheck
+	return args.Get(0).(essentials.Conn), args.Error(1) // nolint: wrapcheck
 }

network/init_test.go

@@ -8,6 +8,7 @@ import (
 	"net/url"
 	"strings"
 
+	"github.com/9seconds/mtg/v2/essentials"
 	"github.com/9seconds/mtg/v2/network"
 	socks5 "github.com/armon/go-socks5"
 	"github.com/mccutchen/go-httpbin/httpbin"
@@ -18,16 +19,16 @@ type DialerMock struct {
 	mock.Mock
 }
 
-func (d *DialerMock) Dial(network, address string) (net.Conn, error) {
+func (d *DialerMock) Dial(network, address string) (essentials.Conn, error) {
 	args := d.Called(network, address)
 
-	return args.Get(0).(net.Conn), args.Error(1) // nolint: wrapcheck
+	return args.Get(0).(essentials.Conn), args.Error(1) // nolint: wrapcheck
 }
 
-func (d *DialerMock) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+func (d *DialerMock) DialContext(ctx context.Context, network, address string) (essentials.Conn, error) {
 	args := d.Called(ctx, network, address)
 
-	return args.Get(0).(net.Conn), args.Error(1) // nolint: wrapcheck
+	return args.Get(0).(essentials.Conn), args.Error(1) // nolint: wrapcheck
 }
 
 type HTTPServerTestSuite struct {
@@ -53,7 +54,9 @@ func (suite *HTTPServerTestSuite) MakeURL(path string) string {
 func (suite *HTTPServerTestSuite) MakeHTTPClient(dialer network.Dialer) *http.Client {
 	return &http.Client{
 		Transport: &http.Transport{
-			DialContext: dialer.DialContext,
+			DialContext: func(ctx context.Context, network, address string) (net.Conn, error) {
+				return dialer.DialContext(ctx, network, address) // nolint: wrapcheck
+			},
 		},
 	}
 }

network/load_balanced_socks5.go

@@ -4,19 +4,20 @@ import (
 	"context"
 	"fmt"
 	"math/rand"
-	"net"
 	"net/url"
+
+	"github.com/9seconds/mtg/v2/essentials"
 )
 
 type loadBalancedSocks5Dialer struct {
 	dialers []Dialer
 }
 
-func (l loadBalancedSocks5Dialer) Dial(network, address string) (net.Conn, error) {
+func (l loadBalancedSocks5Dialer) Dial(network, address string) (essentials.Conn, error) {
 	return l.DialContext(context.Background(), network, address)
 }
 
-func (l loadBalancedSocks5Dialer) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+func (l loadBalancedSocks5Dialer) DialContext(ctx context.Context, network, address string) (essentials.Conn, error) {
 	length := len(l.dialers)
 	start := rand.Intn(length)
 	moved := false

network/network.go

@@ -9,6 +9,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/9seconds/mtg/v2/essentials"
 	"github.com/9seconds/mtg/v2/mtglib"
 )
 
@@ -30,11 +31,11 @@ type network struct {
 	dns         *dnsResolver
 }
 
-func (n *network) Dial(protocol, address string) (net.Conn, error) {
+func (n *network) Dial(protocol, address string) (essentials.Conn, error) {
 	return n.DialContext(context.Background(), protocol, address)
 }
 
-func (n *network) DialContext(ctx context.Context, protocol, address string) (net.Conn, error) {
+func (n *network) DialContext(ctx context.Context, protocol, address string) (essentials.Conn, error) {
 	host, port, _ := net.SplitHostPort(address)
 
 	ips, err := n.dnsResolve(protocol, host)
@@ -46,7 +47,8 @@ func (n *network) DialContext(ctx context.Context, protocol, address string) (ne
 		ips[i], ips[j] = ips[j], ips[i]
 	})
 
-	var conn net.Conn
+	var conn essentials.Conn
+
 	for _, v := range ips {
 		conn, err = n.dialer.DialContext(ctx, protocol, net.JoinHostPort(v, port))
 
@@ -59,7 +61,7 @@ func (n *network) DialContext(ctx context.Context, protocol, address string) (ne
 }
 
 func (n *network) MakeHTTPClient(dialFunc func(ctx context.Context,
-	network, address string) (net.Conn, error)) *http.Client {
+	network, address string) (essentials.Conn, error)) *http.Client {
 	if dialFunc == nil {
 		dialFunc = n.DialContext
 	}
@@ -144,13 +146,15 @@ func NewNetwork(dialer Dialer,
 
 func makeHTTPClient(userAgent string,
 	timeout time.Duration,
-	dialFunc func(ctx context.Context, network, address string) (net.Conn, error)) *http.Client {
+	dialFunc func(ctx context.Context, network, address string) (essentials.Conn, error)) *http.Client {
 	return &http.Client{
 		Timeout: timeout,
 		Transport: networkHTTPTransport{
 			userAgent: userAgent,
 			next: &http.Transport{
-				DialContext: dialFunc,
+				DialContext: func(ctx context.Context, network, address string) (net.Conn, error) {
+					return dialFunc(ctx, network, address)
+				},
 			},
 		},
 	}

network/sockopts.go

@@ -3,45 +3,25 @@ package network
 import (
 	"fmt"
 	"net"
-
-	"golang.org/x/sys/unix"
 )
 
 // SetClientSocketOptions tunes a TCP socket that represents a connection to
 // end user (not Telegram service or fronting domain).
+//
+// bufferSize setting is deprecated and ignored.
 func SetClientSocketOptions(conn net.Conn, bufferSize int) error {
-	tcpConn := conn.(*net.TCPConn) // nolint: forcetypeassert
-
-	if err := tcpConn.SetNoDelay(false); err != nil {
-		return fmt.Errorf("cannot disable TCP_NO_DELAY: %w", err)
-	}
-
-	return setCommonSocketOptions(tcpConn, bufferSize)
+	return setCommonSocketOptions(conn.(*net.TCPConn))
 }
 
 // SetServerSocketOptions tunes a TCP socket that represents a connection to
 // remote server like Telegram or fronting domain (but not end user).
 func SetServerSocketOptions(conn net.Conn, bufferSize int) error {
-	tcpConn := conn.(*net.TCPConn) // nolint: forcetypeassert
-
-	if err := tcpConn.SetNoDelay(true); err != nil {
-		return fmt.Errorf("cannot enable TCP_NO_DELAY: %w", err)
-	}
-
-	return setCommonSocketOptions(tcpConn, bufferSize)
+	return setCommonSocketOptions(conn.(*net.TCPConn))
 }
 
-func setCommonSocketOptions(conn *net.TCPConn, bufferSize int) error {
-	if err := conn.SetReadBuffer(bufferSize); err != nil {
-		return fmt.Errorf("cannot set read buffer size: %w", err)
-	}
-
-	if err := conn.SetWriteBuffer(bufferSize); err != nil {
-		return fmt.Errorf("cannot set write buffer size: %w", err)
-	}
-
-	if err := conn.SetKeepAlive(false); err != nil {
-		return fmt.Errorf("cannot disable TCP keepalive probes: %w", err)
+func setCommonSocketOptions(conn *net.TCPConn) error {
+	if err := conn.SetKeepAlivePeriod(DefaultTCPKeepAlivePeriod); err != nil {
+		return fmt.Errorf("cannot set time period of TCP keepalive probes: %w", err)
 	}
 
 	if err := conn.SetLinger(tcpLingerTimeout); err != nil {
@@ -50,22 +30,12 @@ func setCommonSocketOptions(conn *net.TCPConn, bufferSize int) error {
 
 	rawConn, err := conn.SyscallConn()
 	if err != nil {
-		return fmt.Errorf("cannot get underlying raw connection")
+		return fmt.Errorf("cannot get underlying raw connection: %w", err)
 	}
 
-	rawConn.Control(func(fd uintptr) { // nolint: errcheck
-		err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
-		if err != nil {
-			err = fmt.Errorf("cannot set SO_REUSEADDR: %w", err)
-
-			return
-		}
-
-		err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
-		if err != nil {
-			err = fmt.Errorf("cannot set SO_REUSEPORT: %w", err)
-		}
-	})
+	if err := setSocketReuseAddrPort(rawConn); err != nil {
+		return fmt.Errorf("cannot setup SO_REUSEADDR/PORT: %w", err)
+	}
 
 	return nil
 }

network/sockopts_unix.go

@@ -0,0 +1,31 @@
+//go:build !windows
+// +build !windows
+
+package network
+
+import (
+	"fmt"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+func setSocketReuseAddrPort(conn syscall.RawConn) error {
+	var err error
+
+	conn.Control(func(fd uintptr) { // nolint: errcheck
+		err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
+		if err != nil {
+			err = fmt.Errorf("cannot set SO_REUSEADDR: %w", err)
+
+			return
+		}
+
+		err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
+		if err != nil {
+			err = fmt.Errorf("cannot set SO_REUSEPORT: %w", err)
+		}
+	})
+
+	return err
+}

network/sockopts_windows.go

@@ -0,0 +1,10 @@
+//go:build windows
+// +build windows
+
+package network
+
+import "syscall"
+
+func setSocketReuseAddrPort(conn syscall.RawConn) error {
+	return nil
+}

network/socks5.go

@@ -1,21 +1,162 @@
 package network
 
 import (
+	"context"
 	"fmt"
+	"io"
+	"net"
 	"net/url"
 
-	"golang.org/x/net/proxy"
+	"github.com/9seconds/mtg/v2/essentials"
+	"github.com/txthinking/socks5"
 )
 
+type socks5Dialer struct {
+	Dialer
+
+	username     []byte
+	password     []byte
+	proxyAddress string
+}
+
+func (s socks5Dialer) Dial(network, address string) (essentials.Conn, error) {
+	return s.DialContext(context.Background(), network, address)
+}
+
+func (s socks5Dialer) DialContext(ctx context.Context, network, address string) (essentials.Conn, error) {
+	switch network {
+	case "tcp", "tcp4", "tcp6":
+	default:
+		return nil, fmt.Errorf("%s network type is not supported", network)
+	}
+
+	conn, err := s.Dialer.DialContext(ctx, network, s.proxyAddress)
+	if err != nil {
+		return nil, fmt.Errorf("cannot dial to the proxy: %w", err)
+	}
+
+	if err := s.handshake(conn); err != nil {
+		conn.Close()
+
+		return nil, fmt.Errorf("cannot perform a handshake: %w", err)
+	}
+
+	if err := s.connect(conn, address); err != nil {
+		conn.Close()
+
+		return nil, fmt.Errorf("cannot connect to a destination host %s: %w", address, err)
+	}
+
+	return conn, nil
+}
+
+func (s socks5Dialer) handshake(conn io.ReadWriter) error {
+	authMethod := socks5.MethodUsernamePassword
+	if len(s.username)+len(s.password) == 0 {
+		authMethod = socks5.MethodNone
+	}
+
+	if err := s.handshakeNegotiation(conn, authMethod); err != nil {
+		return fmt.Errorf("cannot perform negotiation: %w", err)
+	}
+
+	if authMethod == socks5.MethodNone {
+		return nil
+	}
+
+	if err := s.handshakeAuth(conn); err != nil {
+		return fmt.Errorf("cannot authenticate: %w", err)
+	}
+
+	return nil
+}
+
+func (s socks5Dialer) handshakeNegotiation(conn io.ReadWriter, authMethod byte) error {
+	request := socks5.NewNegotiationRequest([]byte{authMethod})
+	if _, err := request.WriteTo(conn); err != nil {
+		return fmt.Errorf("cannot send request: %w", err)
+	}
+
+	response, err := socks5.NewNegotiationReplyFrom(conn)
+	if err != nil {
+		return fmt.Errorf("cannot read response: %w", err)
+	}
+
+	if response.Method != authMethod {
+		return fmt.Errorf("%v is unsupported auth method", authMethod)
+	}
+
+	return nil
+}
+
+func (s socks5Dialer) handshakeAuth(conn io.ReadWriter) error {
+	request := socks5.NewUserPassNegotiationRequest(s.username, s.password)
+
+	if _, err := request.WriteTo(conn); err != nil {
+		return fmt.Errorf("cannot send a request: %w", err)
+	}
+
+	response, err := socks5.NewUserPassNegotiationReplyFrom(conn)
+	if err != nil {
+		return fmt.Errorf("cannot read a response: %w", err)
+	}
+
+	if response.Status != socks5.UserPassStatusSuccess {
+		return fmt.Errorf("authenticate has failed: %v", response.Status)
+	}
+
+	return nil
+}
+
+func (s socks5Dialer) connect(conn io.ReadWriter, address string) error {
+	addrType, host, port, err := socks5.ParseAddress(address)
+	if err != nil {
+		return fmt.Errorf("cannot parse address: %w", err)
+	}
+
+	if addrType == socks5.ATYPDomain {
+		host = host[1:]
+	}
+
+	request := socks5.NewRequest(socks5.CmdConnect, addrType, host, port)
+
+	if _, err := request.WriteTo(conn); err != nil {
+		return fmt.Errorf("cannot send a request: %w", err)
+	}
+
+	response, err := socks5.NewReplyFrom(conn)
+	if err != nil {
+		return fmt.Errorf("cannot read a response: %w", err)
+	}
+
+	if response.Rep != socks5.RepSuccess {
+		return fmt.Errorf("unsuccessful request: %v", response.Rep)
+	}
+
+	return nil
+}
+
 // NewSocks5Dialer build a new dialer from a given one (so, in theory
 // you can chain here). Proxy parameters are passed with URI in a form of:
 //
 //     socks5://[user:[password]]@host:port
 func NewSocks5Dialer(baseDialer Dialer, proxyURL *url.URL) (Dialer, error) {
-	rv, err := proxy.FromURL(proxyURL, baseDialer)
-	if err != nil {
-		return nil, fmt.Errorf("cannot initialize socks5 proxy dialer: %w", err)
+	if _, _, err := net.SplitHostPort(proxyURL.Host); err != nil {
+		return nil, fmt.Errorf("incorrect url %s", proxyURL.Redacted())
 	}
 
-	return rv.(Dialer), nil
+	dialer := socks5Dialer{
+		Dialer:       baseDialer,
+		proxyAddress: proxyURL.Host,
+	}
+
+	if proxyURL.User != nil {
+		password, isSet := proxyURL.User.Password()
+		if isSet {
+			dialer.username = []byte(proxyURL.User.Username())
+			dialer.password = []byte(password)
+		}
+	}
+
+	return dialer, nil
 }

network/socks5_test.go

@@ -55,7 +55,7 @@ func (suite *Socks5TestSuite) TestRequestOk() {
 	suite.Equal(http.StatusOK, resp.StatusCode)
 }
 
-func TestSocks5TestSuite(t *testing.T) {
+func TestSocks5(t *testing.T) {
 	t.Parallel()
 	suite.Run(t, &Socks5TestSuite{})
 }