Pull request: * querylog: fix end of log handling

Merge in DNS/adguard-home from 2229-query-log to master

Closes #2229.

Squashed commit of the following:

commit 32508a3f3b1e098869e1649a2774f1f17d14d41f
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Nov 10 16:51:25 2020 +0300

    * querylog: add test

commit 774159cc313a0284a8bb8327489671e5d7a3e4eb
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Nov 10 15:26:26 2020 +0300

    * querylog: better errors

commit 27b13a4dcaff9e8f9b08aec81c0c03f62ebd3fa5
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Nov 10 15:18:51 2020 +0300

    * querylog: fix end of log handling

.github/workflows/build.yml

@@ -134,23 +134,21 @@ jobs:
     runs-on: ubuntu-latest
     needs: test
     steps:
-      -
-        name: Set up Docker Buildx
-        uses: crazy-max/ghaction-docker-buildx@v1
       -
         name: Checkout
         uses: actions/checkout@v2
         with:
           fetch-depth: 0
+      -
+        name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
       -
         name: Docker Buildx (build)
         run: |
           make docker-multi-arch
-      -
-        name: Clear
-        if: always() && startsWith(github.ref, 'refs/tags/v')
-        run: |
-          rm -f ${HOME}/.docker/config.json
 
   notify:
     needs: [app, docker]

.goreleaser.yml

@@ -90,7 +90,13 @@ snapcrafts:
     apps:
       adguard-home:
         command: AdGuardHome -w $SNAP_DATA --no-check-update
-        plugs: [ network-bind ]
+        plugs:
+          # Add the "netrwork-bind" plug to bind to interfaces.
+          - network-bind
+          # Add the "netrwork-control" plug to be able to bind to ports below
+          # 1024 (cap_net_bind_service) and also to bind to a particular
+          # interface using SO_BINDTODEVICE (cap_net_raw).
+          - network-control
         daemon: simple
       adguard-home-web:
         command: adguard-home-web.sh

AGHTechDoc.md

@@ -1587,7 +1587,7 @@ Response:
 		"upstream":"...", // Upstream URL starting with tcp://, tls://, https://, or with an IP address
 		"answer_dnssec": true,
 		"client":"127.0.0.1",
-		"client_proto": "" (plain) | "doh" | "dot",
+		"client_proto": "" (plain) | "doh" | "dot" | "doq",
 		"elapsedMs":"0.098403",
 		"filterId":1,
 		"question":{

Dockerfile

@@ -59,7 +59,6 @@ RUN apk --update --no-cache add \
     ca-certificates \
     libcap \
     libressl \
-    tzdata \
   && rm -rf /tmp/* /var/cache/apk/*
 
 COPY --from=builder --chown=nobody:nogroup /app/AdGuardHome /opt/adguardhome/AdGuardHome

Makefile

@@ -109,7 +109,7 @@ $(error DOCKER_IMAGE_NAME value is not set)
 endif
 
 # OS-specific flags
-TEST_FLAGS := -race
+TEST_FLAGS := --race -v
 ifeq ($(OS),Windows_NT)
 	TEST_FLAGS :=
 endif
@@ -160,11 +160,13 @@ lint-go:
 	@echo Running go linter
 	golangci-lint run
 
-test:
-	@echo Running JS unit-tests
+test: test-js test-go
+
+test-js:
 	npm run test --prefix client
-	@echo Running Go unit-tests
-	go test $(TEST_FLAGS) -v -coverprofile=coverage.txt -covermode=atomic ./...
+
+test-go:
+	go test $(TEST_FLAGS) --coverprofile coverage.txt ./...
 
 ci: client_with_deps
 	go mod download

README.md

@@ -293,7 +293,7 @@ Here is a link to AdGuard Home project: https://crowdin.com/project/adguard-appl
 Here's what you can also do to contribute:
 
 1. [Look for issues](https://github.com/AdguardTeam/AdGuardHome/issues?q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22+) marked as "help wanted".
-2. Actualize the list of *Blocked services*. It it can be found in [dnsfilter/blocked_services.go](https://github.com/AdguardTeam/AdGuardHome/blob/master/dnsfilter/blocked_services.go).
+2. Actualize the list of *Blocked services*. It it can be found in [dnsfilter/blocked_services.go](https://github.com/AdguardTeam/AdGuardHome/blob/master/internal/dnsfilter/blocked_services.go).
 3. Actualize the list of known *trackers*. It it can be found in [client/src/helpers/trackers/adguard.json](https://github.com/AdguardTeam/AdGuardHome/blob/master/client/src/helpers/trackers/adguard.json).
 4. Actualize the list of vetted *blocklists*. It it can be found in [client/src/helpers/filters/filters.json](https://github.com/AdguardTeam/AdGuardHome/blob/master/client/src/helpers/filters/filters.json).
 

client/src/__locales/en.json

@@ -249,6 +249,7 @@
     "blocking_ipv6": "Blocking IPv6",
     "dns_over_https": "DNS-over-HTTPS",
     "dns_over_tls": "DNS-over-TLS",
+    "dns_over_quic": "DNS-over-QUIC",
     "download_mobileconfig_doh": "Download .mobileconfig for DNS-over-HTTPS",
     "download_mobileconfig_dot": "Download .mobileconfig for DNS-over-TLS",
     "plain_dns": "Plain DNS",
@@ -587,4 +588,4 @@
     "adg_will_drop_dns_queries": "AdGuard Home will be dropping all DNS queries from this client.",
     "client_not_in_allowed_clients": "The client is not allowed because it is not in the \"Allowed clients\" list.",
     "experimental": "Experimental"
-}
+}

client/src/helpers/constants.js

@@ -475,6 +475,7 @@ export const BLOCK_ACTIONS = {
 export const SCHEME_TO_PROTOCOL_MAP = {
     doh: 'dns_over_https',
     dot: 'dns_over_tls',
+    doq: 'dns_over_quic',
     '': 'plain_dns',
 };
 

client/src/helpers/highlightTextareaComments.js

@@ -17,7 +17,7 @@ export const getTextareaCommentsHighlight = (
 ) => {
     const renderLine = (line, idx) => renderHighlightedLine(line, idx, commentLineTokens);
 
-    return <code className={classnames('text-output', className)} ref={ref}>{lines?.split('\n').map(renderLine)}</code>;
+    return <code className={classnames('text-output font-monospace', className)} ref={ref}>{lines?.split('\n').map(renderLine)}</code>;
 };
 
 export const syncScroll = (e, ref) => {

go.mod

@@ -3,7 +3,7 @@ module github.com/AdguardTeam/AdGuardHome
 go 1.14
 
 require (
-	github.com/AdguardTeam/dnsproxy v0.32.6
+	github.com/AdguardTeam/dnsproxy v0.33.2
 	github.com/AdguardTeam/golibs v0.4.2
 	github.com/AdguardTeam/urlfilter v0.12.3
 	github.com/NYTimes/gziphandler v1.1.1
@@ -12,25 +12,26 @@ require (
 	github.com/gobuffalo/packr v1.30.1
 	github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714
 	github.com/insomniacslk/dhcp v0.0.0-20200621044212-d74cd86ad5b8
-	github.com/joomcode/errorx v1.0.3
+	github.com/joomcode/errorx v1.0.3 // indirect
 	github.com/kardianos/service v1.1.0
-	github.com/marten-seemann/qtls-go1-15 v0.1.1 // indirect
 	github.com/mdlayher/ethernet v0.0.0-20190606142754-0394541c37b7
 	github.com/mdlayher/raw v0.0.0-20191009151244-50f2db8cc065
-	github.com/miekg/dns v1.1.31
-	github.com/pkg/errors v0.9.1
+	github.com/miekg/dns v1.1.35
+	github.com/rogpeppe/go-internal v1.5.2 // indirect
 	github.com/satori/go.uuid v1.2.0
 	github.com/sirupsen/logrus v1.6.0 // indirect
 	github.com/sparrc/go-ping v0.0.0-20190613174326-4e5b6552494c
-	github.com/stretchr/testify v1.5.1
+	github.com/stretchr/testify v1.6.1
 	github.com/u-root/u-root v6.0.0+incompatible
 	go.etcd.io/bbolt v1.3.4
-	golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a
-	golang.org/x/net v0.0.0-20200904194848-62affa334b73
-	golang.org/x/sys v0.0.0-20200917073148-efd3b9a0ff20
-	golang.org/x/text v0.3.3 // indirect
-	google.golang.org/protobuf v1.25.0 // indirect
+	golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897
+	golang.org/x/net v0.0.0-20201110031124-69a78807bb2b
+	golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9 // indirect
+	golang.org/x/sys v0.0.0-20201109165425-215b40eba54c
+	golang.org/x/text v0.3.4 // indirect
+	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0
 	gopkg.in/yaml.v2 v2.3.0
+	gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776 // indirect
 	howett.net/plist v0.0.0-20200419221736-3b63eb3a43b5
 )

go.sum

@@ -7,8 +7,10 @@ dmitri.shuralyov.com/html/belt v0.0.0-20180602232347-f7d459c86be0/go.mod h1:JLBr
 dmitri.shuralyov.com/service/change v0.0.0-20181023043359-a85b471d5412/go.mod h1:a1inKt/atXimZ4Mv927x+r7UpyzRUf4emIoiiSC2TN4=
 dmitri.shuralyov.com/state v0.0.0-20180228185332-28bcc343414c/go.mod h1:0PRwlb0D6DFvNNtx+9ybjezNCa8XF0xaYcETyp6rHWU=
 git.apache.org/thrift.git v0.0.0-20180902110319-2566ecd5d999/go.mod h1:fPE2ZNJGynbRyZ4dJvy6G277gSllfV2HJqblrnkyeyg=
-github.com/AdguardTeam/dnsproxy v0.32.6 h1:HCKQFUvyvIP3lrJxP8t8+mE/DJwLk2HDmzI/af5PUu4=
-github.com/AdguardTeam/dnsproxy v0.32.6/go.mod h1:ZLDrKIypYxBDz2N9FQHgeehuHrwTbuhZXdGwNySshbw=
+github.com/AdguardTeam/dnsproxy v0.33.1 h1:rEAS1fBEQ3JslzsfkcyMRV96OeBWFnKzXvksduI0ous=
+github.com/AdguardTeam/dnsproxy v0.33.1/go.mod h1:kLi6lMpErnZThy5haiRSis4q0KTB8uPWO4JQsU1EDJA=
+github.com/AdguardTeam/dnsproxy v0.33.2 h1:k5aMcsw3TA/G2DR8EjIkwutDPuuRkKh8xij4cFWC6Fk=
+github.com/AdguardTeam/dnsproxy v0.33.2/go.mod h1:kLi6lMpErnZThy5haiRSis4q0KTB8uPWO4JQsU1EDJA=
 github.com/AdguardTeam/golibs v0.4.0/go.mod h1:skKsDKIBB7kkFflLJBpfGX+G8QFTx0WKUzB6TIgtUj4=
 github.com/AdguardTeam/golibs v0.4.2 h1:7M28oTZFoFwNmp8eGPb3ImmYbxGaJLyQXeIFVHjME0o=
 github.com/AdguardTeam/golibs v0.4.2/go.mod h1:skKsDKIBB7kkFflLJBpfGX+G8QFTx0WKUzB6TIgtUj4=
@@ -25,10 +27,12 @@ github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da h1:KjTM2ks9d14ZYCvmH
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da/go.mod h1:eHEWzANqSiWQsof+nXEI9bUVUyV6F53Fp89EuCh2EAA=
 github.com/aead/poly1305 v0.0.0-20180717145839-3fee0db0b635 h1:52m0LGchQBBVqJRyYYufQuIbVqRawmubW3OFGqK1ekw=
 github.com/aead/poly1305 v0.0.0-20180717145839-3fee0db0b635/go.mod h1:lmLxL+FV291OopO93Bwf9fQLQeLyt33VJRUg5VJ30us=
-github.com/ameshkov/dnscrypt v1.1.0 h1:2vAt5dD6ZmqlAxEAfzRcLBnkvdf8NI46Kn9InSwQbSI=
-github.com/ameshkov/dnscrypt v1.1.0/go.mod h1:ikduAxNLCTEfd1AaCgpIA5TgroIVQ8JY3Vb095fiFJg=
+github.com/ameshkov/dnscrypt/v2 v2.0.0 h1:i83G8MeGLrAFgUL8GSu98TVhtFDEifF7SIS7Qi/RZ3U=
+github.com/ameshkov/dnscrypt/v2 v2.0.0/go.mod h1:nbZnxJt4edIPx2Haa8n2XtC2g5AWcsdQiSuXkNH8eDI=
 github.com/ameshkov/dnsstamps v1.0.1 h1:LhGvgWDzhNJh+kBQd/AfUlq1vfVe109huiXw4JhnPug=
 github.com/ameshkov/dnsstamps v1.0.1/go.mod h1:Ii3eUu73dx4Vw5O4wjzmT5+lkCwovjzaEZZ4gKyIH5A=
+github.com/ameshkov/dnsstamps v1.0.3 h1:Srzik+J9mivH1alRACTbys2xOxs0lRH9qnTA7Y1OYVo=
+github.com/ameshkov/dnsstamps v1.0.3/go.mod h1:Ii3eUu73dx4Vw5O4wjzmT5+lkCwovjzaEZZ4gKyIH5A=
 github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239/go.mod h1:2FmKhYUyUczH0OGQWaF5ceTx0UBShxjsH6f8oGKYe2c=
 github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
 github.com/beefsack/go-rate v0.0.0-20180408011153-efa7637bb9b6 h1:KXlsf+qt/X5ttPGEjR0tPH1xaWWoKBEg9Q1THAj2h3I=
@@ -98,6 +102,8 @@ github.com/golang/protobuf v1.4.0/go.mod h1:jodUvKwWbYaEsadDk5Fwe5c77LiNKVO9IDvq
 github.com/golang/protobuf v1.4.1/go.mod h1:U8fpvMrcmy5pZrNK1lt4xCsGvpyWQ/VVv6QDs8UjoX8=
 github.com/golang/protobuf v1.4.2 h1:+Z5KGCizgyZCbGh1KZqA0fcLLkwbsjIzS4aV2v7wJX0=
 github.com/golang/protobuf v1.4.2/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
+github.com/golang/protobuf v1.4.3 h1:JjCZWpVbqXDqFVmTfYWEVTMIYrL/NPdPSCHPJ0T/raM=
+github.com/golang/protobuf v1.4.3/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
 github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
@@ -152,8 +158,8 @@ github.com/kr/pty v1.1.3/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/lucas-clemente/quic-go v0.18.0 h1:JhQDdqxdwdmGdKsKgXi1+coHRoGhvU6z0rNzOJqZ/4o=
-github.com/lucas-clemente/quic-go v0.18.0/go.mod h1:yXttHsSNxQi8AWijC/vLP+OJczXqzHSOcJrM5ITUlCg=
+github.com/lucas-clemente/quic-go v0.18.1 h1:DMR7guC0NtVS8zNZR3IO7NARZvZygkSC56GGtC6cyys=
+github.com/lucas-clemente/quic-go v0.18.1/go.mod h1:yXttHsSNxQi8AWijC/vLP+OJczXqzHSOcJrM5ITUlCg=
 github.com/lunixbochs/vtclean v1.0.0/go.mod h1:pHhQNgMf3btfWnGBVipUOjRYhoOsdGqdm/+2c2E2WMI=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mailru/easyjson v0.0.0-20190312143242-1de009706dbe/go.mod h1:C1wdFJiN94OJF2b5HbByQZoLdCWB1Yqtg26g4irojpc=
@@ -173,8 +179,9 @@ github.com/mdlayher/raw v0.0.0-20191009151244-50f2db8cc065/go.mod h1:7EpbotpCmVZ
 github.com/microcosm-cc/bluemonday v1.0.1/go.mod h1:hsXNsILzKxV+sX77C5b8FSuKF00vh2OMYv+xgHpAMF4=
 github.com/miekg/dns v1.1.29 h1:xHBEhR+t5RzcFJjBLJlax2daXOrTYtr9z4WdKEfWFzg=
 github.com/miekg/dns v1.1.29/go.mod h1:KNUDUusw/aVsxyTYZM1oqvCicbwhgbNgztCETuNZ7xM=
-github.com/miekg/dns v1.1.31 h1:sJFOl9BgwbYAWOGEwr61FU28pqsBNdpRBnhGXtO06Oo=
-github.com/miekg/dns v1.1.31/go.mod h1:KNUDUusw/aVsxyTYZM1oqvCicbwhgbNgztCETuNZ7xM=
+github.com/miekg/dns v1.1.34/go.mod h1:KNUDUusw/aVsxyTYZM1oqvCicbwhgbNgztCETuNZ7xM=
+github.com/miekg/dns v1.1.35 h1:oTfOaDH+mZkdcgdIjH6yBajRGtIwcwcaR+rt23ZSrJs=
+github.com/miekg/dns v1.1.35/go.mod h1:KNUDUusw/aVsxyTYZM1oqvCicbwhgbNgztCETuNZ7xM=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
@@ -209,6 +216,8 @@ github.com/prometheus/procfs v0.0.0-20180725123919-05ee40e3a273/go.mod h1:c3At6R
 github.com/rogpeppe/go-internal v1.1.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rogpeppe/go-internal v1.3.0 h1:RR9dF3JtopPvtkroDZuVD7qquD0bnHlKSqaQhgwt8yk=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
+github.com/rogpeppe/go-internal v1.5.2 h1:qLvObTrvO/XRCqmkKxUlOBc48bI3efyDuAZe25QiF0w=
+github.com/rogpeppe/go-internal v1.5.2/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
 github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
 github.com/satori/go.uuid v1.2.0 h1:0uYX9dsZ2yD7q2RtLRtPSdGDWzjeM3TbMJP9utgA0ww=
 github.com/satori/go.uuid v1.2.0/go.mod h1:dA0hQrYB0VpLJoorglMZABFdXlWrHn1NEOzdhQKdks0=
@@ -261,6 +270,8 @@ github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UV
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/tarm/serial v0.0.0-20180830185346-98f6abe2eb07/go.mod h1:kDXzergiv9cbyO7IOYJZWg1U88JhDg3PB6klq9Hg2pA=
 github.com/u-root/u-root v6.0.0+incompatible h1:YqPGmRoRyYmeg17KIWFRSyVq6LX5T6GSzawyA6wG6EE=
 github.com/u-root/u-root v6.0.0+incompatible/go.mod h1:RYkpo8pTHrNjW08opNd/U6p/RJE7K0D8fXO0d47+3YY=
@@ -284,12 +295,13 @@ golang.org/x/crypto v0.0.0-20200221231518-2aa609cf4a9d/go.mod h1:LzIPMQfyMNhhGPh
 golang.org/x/crypto v0.0.0-20200323165209-0ec3e9974c59/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9 h1:psW17arqaxU48Z5kZ0CQnkZWQJsqcURM6tKiBApRjXI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a h1:vclmkQCjlDX5OydZ9wv8rBCcS0QyQY66Mpf/7BZbInM=
-golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897 h1:pLI5jrR7OSLijeIDcmRxNmw2api+jEfxLoykJVice/E=
+golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20180702182130-06c8688daad7/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
+golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3 h1:XQyxROzUlZH+WIQwySDgnISgOivlhjIEwaQaJEJrrN0=
 golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -312,8 +324,11 @@ golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e/go.mod h1:qpuaurCH72eLCgpAm/
 golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/net v0.0.0-20200707034311-ab3426394381 h1:VXak5I6aEWmAXeQjA+QSZzlgNrpq9mjcfDemuexIKsU=
 golang.org/x/net v0.0.0-20200707034311-ab3426394381/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
-golang.org/x/net v0.0.0-20200904194848-62affa334b73 h1:MXfv8rhZWmFeqX3GNZRsd6vOLoaCHjYEX3qkRo3YBUA=
-golang.org/x/net v0.0.0-20200904194848-62affa334b73/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
+golang.org/x/net v0.0.0-20201016165138-7b1cca2348c0/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/net v0.0.0-20201031054903-ff519b6c9102 h1:42cLlJJdEh+ySyeUUbEQ5bsTiq8voBeTuweGVkY6Puw=
+golang.org/x/net v0.0.0-20201031054903-ff519b6c9102/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/net v0.0.0-20201110031124-69a78807bb2b h1:uwuIcX0g4Yl1NC5XAz37xsr2lTtcqevgzYNVt49waME=
+golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20181017192945-9dcd33a902f4/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20181203162652-d668ce993890/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
@@ -327,6 +342,8 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a h1:WXEvlFVvvGxCJLG6REjsT03iWnKLEWinaScsxF2Vm2o=
 golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9 h1:SQFwaSi55rU7vdNs9Yr0Z324VNlrF+0wMqRXT4St8ck=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181029174526-d69651ed3497/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -351,8 +368,12 @@ golang.org/x/sys v0.0.0-20200331124033-c3d80250170d h1:nc5K6ox/4lTFbMVSL9WRR81ix
 golang.org/x/sys v0.0.0-20200331124033-c3d80250170d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200519105757-fe76b779f299 h1:DYfZAGf2WMFjMxbgTjaC+2HC7NkNAQs+6Q8b9WEB/F4=
 golang.org/x/sys v0.0.0-20200519105757-fe76b779f299/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200917073148-efd3b9a0ff20 h1:4X356008q5SA3YXu8PiRap39KFmy4Lf6sGlceJKZQsU=
-golang.org/x/sys v0.0.0-20200917073148-efd3b9a0ff20/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201018230417-eeed37f84f13/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201107080550-4d91cf3a1aaf h1:kt3wY1Lu5MJAnKTfoMR52Cu4gwvna4VTzNOiT8tY73s=
+golang.org/x/sys v0.0.0-20201107080550-4d91cf3a1aaf/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201109165425-215b40eba54c h1:+B+zPA6081G5cEb2triOIJpcvSW4AYzmIyWAqMn2JAc=
+golang.org/x/sys v0.0.0-20201109165425-215b40eba54c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 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=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -360,6 +381,8 @@ golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.4 h1:0YWbFKbhXG/wIiuHDSKpS0Iy7FSA+u45VtBMfQcFTTc=
+golang.org/x/text v0.3.4/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/tools v0.0.0-20180828015842-6cd1fcedba52/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
@@ -376,6 +399,8 @@ golang.org/x/tools v0.0.0-20191216052735-49a3e744a425/go.mod h1:TB2adYChydJhpapK
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/api v0.0.0-20180910000450-7ca32eb868bf/go.mod h1:4mhQ8q/RsB7i+udVvVy5NUi08OU8ZlA0gRVgrF7VFY0=
 google.golang.org/api v0.0.0-20181030000543-1d582fd0359e/go.mod h1:4mhQ8q/RsB7i+udVvVy5NUi08OU8ZlA0gRVgrF7VFY0=
 google.golang.org/api v0.1.0/go.mod h1:UGEZY7KEX120AnNLIHFMKIo4obdJhkp2tPbaPlQx13Y=
@@ -427,6 +452,11 @@ gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
 gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
 gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20200605160147-a5ece683394c h1:grhR+C34yXImVGp7EzNk+DTIk+323eIUWOmEevy6bDo=
+gopkg.in/yaml.v3 v3.0.0-20200605160147-a5ece683394c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776 h1:tQIYjPdBoyREyB9XMu+nnTclpTYkz2zFM+lzLJFO4gQ=
+gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 grpc.go4.org v0.0.0-20170609214715-11d0a25b4919/go.mod h1:77eQGdRu53HpSqPFJFmuJdjuHRquDANNeA4x7B8WQ9o=
 honnef.co/go/tools v0.0.0-20180728063816-88497007e858/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

internal/agherr/agherr.go

@@ -0,0 +1,67 @@
+// Package agherr contains the extended error type, and the function for
+// wrapping several errors.
+package agherr
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Error is the constant error type.
+type Error string
+
+// Error implements the error interface for Error.
+func (err Error) Error() (msg string) {
+	return string(err)
+}
+
+// manyError is an error containing several wrapped errors.  It is created to be
+// a simpler version of the API provided by github.com/joomcode/errorx.
+type manyError struct {
+	message    string
+	underlying []error
+}
+
+// Many wraps several errors and returns a single error.
+func Many(message string, underlying ...error) error {
+	err := &manyError{
+		message:    message,
+		underlying: underlying,
+	}
+
+	return err
+}
+
+// Error implements the error interface for *manyError.
+func (e *manyError) Error() string {
+	switch len(e.underlying) {
+	case 0:
+		return e.message
+	case 1:
+		return fmt.Sprintf("%s: %s", e.message, e.underlying[0])
+	default:
+		b := &strings.Builder{}
+
+		// Ignore errors, since strings.(*Buffer).Write never returns
+		// errors.
+		_, _ = fmt.Fprintf(b, "%s: %s (hidden: %s", e.message, e.underlying[0], e.underlying[1])
+		for _, u := range e.underlying[2:] {
+			// See comment above.
+			_, _ = fmt.Fprintf(b, ", %s", u)
+		}
+
+		// See comment above.
+		_, _ = b.WriteString(")")
+
+		return b.String()
+	}
+}
+
+// Unwrap implements the hidden errors.wrapper interface for *manyError.
+func (e *manyError) Unwrap() error {
+	if len(e.underlying) == 0 {
+		return nil
+	}
+
+	return e.underlying[0]
+}

internal/agherr/agherr_test.go

@@ -0,0 +1,73 @@
+package agherr
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestError_Error(t *testing.T) {
+	testCases := []struct {
+		name string
+		want string
+		err  error
+	}{{
+		name: "simple",
+		want: "a",
+		err:  Many("a"),
+	}, {
+		name: "wrapping",
+		want: "a: b",
+		err:  Many("a", errors.New("b")),
+	}, {
+		name: "wrapping several",
+		want: "a: b (hidden: c, d)",
+		err:  Many("a", errors.New("b"), errors.New("c"), errors.New("d")),
+	}, {
+		name: "wrapping wrapper",
+		want: "a: b: c (hidden: d)",
+		err:  Many("a", Many("b", errors.New("c"), errors.New("d"))),
+	}}
+	for _, tc := range testCases {
+		assert.Equal(t, tc.want, tc.err.Error(), tc.name)
+	}
+}
+
+func TestError_Unwrap(t *testing.T) {
+	const (
+		errSimple = iota
+		errWrapped
+		errNil
+	)
+	errs := []error{
+		errSimple:  errors.New("a"),
+		errWrapped: fmt.Errorf("%w", errors.New("nested")),
+		errNil:     nil,
+	}
+	testCases := []struct {
+		name    string
+		want    error
+		wrapped error
+	}{{
+		name:    "simple",
+		want:    errs[errSimple],
+		wrapped: Many("a", errs[errSimple]),
+	}, {
+		name:    "nested",
+		want:    errs[errWrapped],
+		wrapped: Many("b", errs[errWrapped]),
+	}, {
+		name:    "nil passed",
+		want:    errs[errNil],
+		wrapped: Many("c", errs[errNil]),
+	}, {
+		name:    "nil not passed",
+		want:    nil,
+		wrapped: Many("d"),
+	}}
+	for _, tc := range testCases {
+		assert.Equal(t, tc.want, errors.Unwrap(tc.wrapped), tc.name)
+	}
+}

internal/dhcpd/check_other_dhcp.go

@@ -10,7 +10,7 @@ import (
 	"runtime"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/dhcpd/nclient4"
+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpd/nclient4"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/insomniacslk/dhcp/dhcpv4"
 	"github.com/insomniacslk/dhcp/dhcpv6"
@@ -23,15 +23,19 @@ import (
 func CheckIfOtherDHCPServersPresentV4(ifaceName string) (bool, error) {
 	iface, err := net.InterfaceByName(ifaceName)
 	if err != nil {
-		return false, wrapErrPrint(err, "Couldn't find interface by name %s", ifaceName)
+		return false, fmt.Errorf("couldn't find interface by name %s: %w", ifaceName, err)
 	}
 
-	// get ipv4 address of an interface
-	ifaceIPNet := getIfaceIPv4(*iface)
+	ifaceIPNet, err := ifaceIPv4Addrs(iface)
+	if err != nil {
+		return false, fmt.Errorf("getting ipv4 addrs for iface %s: %w", ifaceName, err)
+	}
 	if len(ifaceIPNet) == 0 {
-		return false, fmt.Errorf("couldn't find IPv4 address of interface %s %+v", ifaceName, iface)
+		return false, fmt.Errorf("interface %s has no ipv4 addresses", ifaceName)
 	}
 
+	// TODO(a.garipov): Find out what this is about.  Perhaps this
+	// information is outdated or at least incomplete.
 	if runtime.GOOS == "darwin" {
 		return false, fmt.Errorf("can't find DHCP server: not supported on macOS")
 	}
@@ -44,7 +48,7 @@ func CheckIfOtherDHCPServersPresentV4(ifaceName string) (bool, error) {
 
 	req, err := dhcpv4.NewDiscovery(iface.HardwareAddr)
 	if err != nil {
-		return false, fmt.Errorf("dhcpv4.NewDiscovery: %s", err)
+		return false, fmt.Errorf("dhcpv4.NewDiscovery: %w", err)
 	}
 	req.Options.Update(dhcpv4.OptClientIdentifier(iface.HardwareAddr))
 	req.Options.Update(dhcpv4.OptHostName(hostname))
@@ -52,24 +56,24 @@ func CheckIfOtherDHCPServersPresentV4(ifaceName string) (bool, error) {
 	// resolve 0.0.0.0:68
 	udpAddr, err := net.ResolveUDPAddr("udp4", src)
 	if err != nil {
-		return false, wrapErrPrint(err, "Couldn't resolve UDP address %s", src)
+		return false, fmt.Errorf("couldn't resolve UDP address %s: %w", src, err)
 	}
 
 	if !udpAddr.IP.To4().Equal(srcIP) {
-		return false, wrapErrPrint(err, "Resolved UDP address is not %s", src)
+		return false, fmt.Errorf("resolved UDP address is not %s: %w", src, err)
 	}
 
 	// resolve 255.255.255.255:67
 	dstAddr, err := net.ResolveUDPAddr("udp4", dst)
 	if err != nil {
-		return false, wrapErrPrint(err, "Couldn't resolve UDP address %s", dst)
+		return false, fmt.Errorf("couldn't resolve UDP address %s: %w", dst, err)
 	}
 
 	// bind to 0.0.0.0:68
 	log.Tracef("Listening to udp4 %+v", udpAddr)
 	c, err := nclient4.NewRawUDPConn(ifaceName, 68)
 	if err != nil {
-		return false, wrapErrPrint(err, "Couldn't listen on :68")
+		return false, fmt.Errorf("couldn't listen on :68: %w", err)
 	}
 	if c != nil {
 		defer c.Close()
@@ -78,61 +82,84 @@ func CheckIfOtherDHCPServersPresentV4(ifaceName string) (bool, error) {
 	// send to 255.255.255.255:67
 	_, err = c.WriteTo(req.ToBytes(), dstAddr)
 	if err != nil {
-		return false, wrapErrPrint(err, "Couldn't send a packet to %s", dst)
+		return false, fmt.Errorf("couldn't send a packet to %s: %w", dst, err)
 	}
 
 	for {
-		// wait for answer
-		log.Tracef("Waiting %v for an answer", defaultDiscoverTime)
-		// TODO: replicate dhclient's behaviour of retrying several times with progressively bigger timeouts
-		b := make([]byte, 1500)
-		_ = c.SetReadDeadline(time.Now().Add(defaultDiscoverTime))
-		n, _, err := c.ReadFrom(b)
-		if isTimeout(err) {
-			// timed out -- no DHCP servers
-			log.Debug("DHCPv4: didn't receive DHCP response")
-			return false, nil
-		}
-		if err != nil {
-			return false, wrapErrPrint(err, "Couldn't receive packet")
-		}
-
-		log.Tracef("Received packet (%v bytes)", n)
-
-		response, err := dhcpv4.FromBytes(b[:n])
-		if err != nil {
-			log.Debug("DHCPv4: dhcpv4.FromBytes: %s", err)
+		ok, next, err := tryConn(req, c, iface)
+		if next {
 			continue
 		}
-
-		log.Debug("DHCPv4: received message from server: %s", response.Summary())
-
-		if !(response.OpCode == dhcpv4.OpcodeBootReply &&
-			response.HWType == iana.HWTypeEthernet &&
-			bytes.Equal(response.ClientHWAddr, iface.HardwareAddr) &&
-			bytes.Equal(response.TransactionID[:], req.TransactionID[:]) &&
-			response.Options.Has(dhcpv4.OptionDHCPMessageType)) {
-			log.Debug("DHCPv4: received message from server doesn't match our request")
-			continue
+		if ok {
+			return true, nil
+		}
+		if err != nil {
+			log.Debug("%s", err)
 		}
-
-		log.Tracef("The packet is from an active DHCP server")
-		// that's a DHCP server there
-		return true, nil
 	}
 }
 
+// TODO(a.garipov): Refactor further.  Inspect error handling, remove the next
+// parameter, address the TODO, etc.
+func tryConn(req *dhcpv4.DHCPv4, c net.PacketConn, iface *net.Interface) (ok, next bool, err error) {
+	// TODO: replicate dhclient's behavior of retrying several times with
+	// progressively longer timeouts.
+	log.Tracef("waiting %v for an answer", defaultDiscoverTime)
+
+	b := make([]byte, 1500)
+	_ = c.SetReadDeadline(time.Now().Add(defaultDiscoverTime))
+	n, _, err := c.ReadFrom(b)
+	if err != nil {
+		if isTimeout(err) {
+			log.Debug("dhcpv4: didn't receive dhcp response")
+
+			return false, false, nil
+		}
+
+		return false, false, fmt.Errorf("receiving packet: %w", err)
+	}
+
+	log.Tracef("received packet, %d bytes", n)
+
+	response, err := dhcpv4.FromBytes(b[:n])
+	if err != nil {
+		log.Debug("dhcpv4: encoding: %s", err)
+
+		return false, true, err
+	}
+
+	log.Debug("dhcpv4: received message from server: %s", response.Summary())
+
+	if !(response.OpCode == dhcpv4.OpcodeBootReply &&
+		response.HWType == iana.HWTypeEthernet &&
+		bytes.Equal(response.ClientHWAddr, iface.HardwareAddr) &&
+		bytes.Equal(response.TransactionID[:], req.TransactionID[:]) &&
+		response.Options.Has(dhcpv4.OptionDHCPMessageType)) {
+
+		log.Debug("dhcpv4: received message from server doesn't match our request")
+
+		return false, true, nil
+	}
+
+	log.Tracef("the packet is from an active dhcp server")
+
+	return true, false, nil
+}
+
 // CheckIfOtherDHCPServersPresentV6 sends a DHCP request to the specified network interface,
 // and waits for a response for a period defined by defaultDiscoverTime
 func CheckIfOtherDHCPServersPresentV6(ifaceName string) (bool, error) {
 	iface, err := net.InterfaceByName(ifaceName)
 	if err != nil {
-		return false, fmt.Errorf("DHCPv6: net.InterfaceByName: %s: %s", ifaceName, err)
+		return false, fmt.Errorf("dhcpv6: net.InterfaceByName: %s: %w", ifaceName, err)
 	}
 
-	ifaceIPNet := getIfaceIPv6(*iface)
+	ifaceIPNet, err := ifaceIPv6Addrs(iface)
+	if err != nil {
+		return false, fmt.Errorf("getting ipv6 addrs for iface %s: %w", ifaceName, err)
+	}
 	if len(ifaceIPNet) == 0 {
-		return false, fmt.Errorf("DHCPv6: couldn't find IPv6 address of interface %s %+v", ifaceName, iface)
+		return false, fmt.Errorf("interface %s has no ipv6 addresses", ifaceName)
 	}
 
 	srcIP := ifaceIPNet[0]
@@ -141,27 +168,27 @@ func CheckIfOtherDHCPServersPresentV6(ifaceName string) (bool, error) {
 
 	req, err := dhcpv6.NewSolicit(iface.HardwareAddr)
 	if err != nil {
-		return false, fmt.Errorf("DHCPv6: dhcpv6.NewSolicit: %s", err)
+		return false, fmt.Errorf("dhcpv6: dhcpv6.NewSolicit: %w", err)
 	}
 
 	udpAddr, err := net.ResolveUDPAddr("udp6", src)
 	if err != nil {
-		return false, wrapErrPrint(err, "DHCPv6: Couldn't resolve UDP address %s", src)
+		return false, fmt.Errorf("dhcpv6: Couldn't resolve UDP address %s: %w", src, err)
 	}
 
 	if !udpAddr.IP.To16().Equal(srcIP) {
-		return false, wrapErrPrint(err, "DHCPv6: Resolved UDP address is not %s", src)
+		return false, fmt.Errorf("dhcpv6: Resolved UDP address is not %s: %w", src, err)
 	}
 
 	dstAddr, err := net.ResolveUDPAddr("udp6", dst)
 	if err != nil {
-		return false, fmt.Errorf("DHCPv6: Couldn't resolve UDP address %s: %s", dst, err)
+		return false, fmt.Errorf("dhcpv6: Couldn't resolve UDP address %s: %w", dst, err)
 	}
 
 	log.Debug("DHCPv6: Listening to udp6 %+v", udpAddr)
 	c, err := nclient6.NewIPv6UDPConn(ifaceName, dhcpv6.DefaultClientPort)
 	if err != nil {
-		return false, fmt.Errorf("DHCPv6: Couldn't listen on :546: %s", err)
+		return false, fmt.Errorf("dhcpv6: Couldn't listen on :546: %w", err)
 	}
 	if c != nil {
 		defer c.Close()
@@ -169,7 +196,7 @@ func CheckIfOtherDHCPServersPresentV6(ifaceName string) (bool, error) {
 
 	_, err = c.WriteTo(req.ToBytes(), dstAddr)
 	if err != nil {
-		return false, fmt.Errorf("DHCPv6: Couldn't send a packet to %s: %s", dst, err)
+		return false, fmt.Errorf("dhcpv6: Couldn't send a packet to %s: %w", dst, err)
 	}
 
 	for {
@@ -182,7 +209,7 @@ func CheckIfOtherDHCPServersPresentV6(ifaceName string) (bool, error) {
 			return false, nil
 		}
 		if err != nil {
-			return false, wrapErrPrint(err, "Couldn't receive packet")
+			return false, fmt.Errorf("couldn't receive packet: %w", err)
 		}
 
 		log.Debug("DHCPv6: Received packet (%v bytes)", n)

internal/dhcpd/dhcp_http.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 
 	"github.com/AdguardTeam/golibs/jsonutil"
 	"github.com/AdguardTeam/golibs/log"
@@ -175,7 +175,7 @@ func (s *Server) handleDHCPSetConfig(w http.ResponseWriter, r *http.Request) {
 		v6conf.InterfaceName = newconfig.InterfaceName
 		v6conf.notify = s.onNotify
 		s6, err = v6Create(v6conf)
-		if s6 == nil {
+		if err != nil {
 			httpError(r, w, http.StatusBadRequest, "Invalid DHCPv6 configuration: %s", err)
 			return
 		}
@@ -302,17 +302,17 @@ func (s *Server) handleDHCPInterfaces(w http.ResponseWriter, r *http.Request) {
 func (s *Server) handleDHCPFindActiveServer(w http.ResponseWriter, r *http.Request) {
 	body, err := ioutil.ReadAll(r.Body)
 	if err != nil {
-		errorText := fmt.Sprintf("failed to read request body: %s", err)
-		log.Error(errorText)
-		http.Error(w, errorText, http.StatusBadRequest)
+		msg := fmt.Sprintf("failed to read request body: %s", err)
+		log.Error(msg)
+		http.Error(w, msg, http.StatusBadRequest)
 		return
 	}
 
 	interfaceName := strings.TrimSpace(string(body))
 	if interfaceName == "" {
-		errorText := fmt.Sprintf("empty interface name specified")
-		log.Error(errorText)
-		http.Error(w, errorText, http.StatusBadRequest)
+		msg := "empty interface name specified"
+		log.Error(msg)
+		http.Error(w, msg, http.StatusBadRequest)
 		return
 	}
 
@@ -335,7 +335,7 @@ func (s *Server) handleDHCPFindActiveServer(w http.ResponseWriter, r *http.Reque
 	foundVal := "no"
 	if found4 {
 		foundVal = "yes"
-	} else if err != nil {
+	} else if err4 != nil {
 		foundVal = "error"
 		othSrv["error"] = err4.Error()
 	}
@@ -370,7 +370,6 @@ func (s *Server) handleDHCPFindActiveServer(w http.ResponseWriter, r *http.Reque
 }
 
 func (s *Server) handleDHCPAddStaticLease(w http.ResponseWriter, r *http.Request) {
-
 	lj := staticLeaseJSON{}
 	err := json.NewDecoder(r.Body).Decode(&lj)
 	if err != nil {
@@ -424,7 +423,6 @@ func (s *Server) handleDHCPAddStaticLease(w http.ResponseWriter, r *http.Request
 }
 
 func (s *Server) handleDHCPRemoveStaticLease(w http.ResponseWriter, r *http.Request) {
-
 	lj := staticLeaseJSON{}
 	err := json.NewDecoder(r.Body).Decode(&lj)
 	if err != nil {

internal/dhcpd/dhcpd.go

@@ -9,7 +9,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/golibs/log"
 )
 

internal/dhcpd/dhcpd_test.go

@@ -12,12 +12,6 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func check(t *testing.T, result bool, msg string) {
-	if !result {
-		t.Fatal(msg)
-	}
-}
-
 func testNotify(flags uint32) {
 }
 
@@ -83,7 +77,6 @@ func TestIsValidSubnetMask(t *testing.T) {
 func TestNormalizeLeases(t *testing.T) {
 	dynLeases := []*Lease{}
 	staticLeases := []*Lease{}
-	leases := []*Lease{}
 
 	lease := &Lease{}
 	lease.HWAddr = []byte{1, 2, 3, 4}
@@ -100,7 +93,7 @@ func TestNormalizeLeases(t *testing.T) {
 	lease.HWAddr = []byte{2, 2, 3, 4}
 	staticLeases = append(staticLeases, lease)
 
-	leases = normalizeLeases(staticLeases, dynLeases)
+	leases := normalizeLeases(staticLeases, dynLeases)
 
 	assert.True(t, len(leases) == 3)
 	assert.True(t, bytes.Equal(leases[0].HWAddr, []byte{1, 2, 3, 4}))

internal/dhcpd/helpers.go

@@ -4,9 +4,6 @@ import (
 	"encoding/binary"
 	"fmt"
 	"net"
-
-	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
 )
 
 func isTimeout(err error) bool {
@@ -17,37 +14,6 @@ func isTimeout(err error) bool {
 	return operr.Timeout()
 }
 
-// Get IPv4 address list
-func getIfaceIPv4(iface net.Interface) []net.IP {
-	addrs, err := iface.Addrs()
-	if err != nil {
-		return nil
-	}
-
-	var res []net.IP
-	for _, a := range addrs {
-		ipnet, ok := a.(*net.IPNet)
-		if !ok {
-			continue
-		}
-		if ipnet.IP.To4() != nil {
-			res = append(res, ipnet.IP.To4())
-		}
-	}
-	return res
-}
-
-func wrapErrPrint(err error, message string, args ...interface{}) error {
-	var errx error
-	if err == nil {
-		errx = fmt.Errorf(message, args...)
-	} else {
-		errx = errorx.Decorate(err, message, args...)
-	}
-	log.Println(errx.Error())
-	return errx
-}
-
 func parseIPv4(text string) (net.IP, error) {
 	result := net.ParseIP(text)
 	if result == nil {

internal/dhcpd/nclient4/client.go

@@ -48,14 +48,12 @@ const (
 	ServerPort = 67
 )
 
-var (
-	// DefaultServers is the address of all link-local DHCP servers and
-	// relay agents.
-	DefaultServers = &net.UDPAddr{
-		IP:   net.IPv4bcast,
-		Port: ServerPort,
-	}
-)
+// DefaultServers is the address of all link-local DHCP servers and
+// relay agents.
+var DefaultServers = &net.UDPAddr{
+	IP:   net.IPv4bcast,
+	Port: ServerPort,
+}
 
 var (
 	// ErrNoResponse is returned when no response packet is received.
@@ -375,14 +373,6 @@ func WithHWAddr(hwAddr net.HardwareAddr) ClientOpt {
 	}
 }
 
-// nolint
-func withBufferCap(n int) ClientOpt {
-	return func(c *Client) (err error) {
-		c.bufferCap = n
-		return
-	}
-}
-
 // WithRetry configures the number of retransmissions to attempt.
 //
 // Default is 3.

internal/dhcpd/nclient4/client_test.go

@@ -122,6 +122,13 @@ func newPacket(op dhcpv4.OpcodeType, xid dhcpv4.TransactionID) *dhcpv4.DHCPv4 {
 	return p
 }
 
+func withBufferCap(n int) ClientOpt {
+	return func(c *Client) (err error) {
+		c.bufferCap = n
+		return
+	}
+}
+
 func TestSendAndRead(t *testing.T) {
 	for _, tt := range []struct {
 		desc   string

internal/dhcpd/network_utils.go

@@ -10,7 +10,7 @@ import (
 	"runtime"
 	"strings"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 
 	"github.com/AdguardTeam/golibs/file"
 
@@ -73,7 +73,6 @@ func hasStaticIPDhcpcdConf(dhcpConf, ifaceName string) bool {
 				// we found our interface
 				withinInterfaceCtx = true
 			}
-
 		} else {
 			if strings.HasPrefix(line, "interface ") {
 				// we found another interface - reset our state
@@ -240,7 +239,7 @@ func getNetworkSetupHardwareReports() map[string]string {
 		return nil
 	}
 
-	m := make(map[string]string, 0)
+	m := make(map[string]string)
 
 	matches := re.FindAllStringSubmatch(out, -1)
 	for i := range matches {

internal/dhcpd/router_adv.go

@@ -163,7 +163,7 @@ func (ra *raCtx) Init() error {
 		return nil
 	}
 
-	log.Debug("DHCPv6 RA: source IP address: %s  DNS IP address: %s",
+	log.Debug("dhcpv6 ra: source IP address: %s  DNS IP address: %s",
 		ra.ipAddr, ra.dnsIPAddr)
 
 	params := icmpv6RA{
@@ -183,7 +183,7 @@ func (ra *raCtx) Init() error {
 	ipAndScope := ra.ipAddr.String() + "%" + ra.ifaceName
 	ra.conn, err = icmp.ListenPacket("ip6:ipv6-icmp", ipAndScope)
 	if err != nil {
-		return fmt.Errorf("DHCPv6 RA: icmp.ListenPacket: %s", err)
+		return fmt.Errorf("dhcpv6 ra: icmp.ListenPacket: %w", err)
 	}
 	success := false
 	defer func() {
@@ -195,11 +195,11 @@ func (ra *raCtx) Init() error {
 	con6 := ra.conn.IPv6PacketConn()
 
 	if err := con6.SetHopLimit(255); err != nil {
-		return fmt.Errorf("DHCPv6 RA: SetHopLimit: %s", err)
+		return fmt.Errorf("dhcpv6 ra: SetHopLimit: %w", err)
 	}
 
 	if err := con6.SetMulticastHopLimit(255); err != nil {
-		return fmt.Errorf("DHCPv6 RA: SetMulticastHopLimit: %s", err)
+		return fmt.Errorf("dhcpv6 ra: SetMulticastHopLimit: %w", err)
 	}
 
 	msg := &ipv6.ControlMessage{
@@ -212,15 +212,15 @@ func (ra *raCtx) Init() error {
 	}
 
 	go func() {
-		log.Debug("DHCPv6 RA: starting to send periodic RouterAdvertisement packets")
+		log.Debug("dhcpv6 ra: starting to send periodic RouterAdvertisement packets")
 		for ra.stop.Load() == 0 {
 			_, err = con6.WriteTo(data, msg, addr)
 			if err != nil {
-				log.Error("DHCPv6 RA: WriteTo: %s", err)
+				log.Error("dhcpv6 ra: WriteTo: %s", err)
 			}
 			time.Sleep(ra.packetSendPeriod)
 		}
-		log.Debug("DHCPv6 RA: loop exit")
+		log.Debug("dhcpv6 ra: loop exit")
 	}()
 
 	success = true
@@ -229,7 +229,7 @@ func (ra *raCtx) Init() error {
 
 // Close - close module
 func (ra *raCtx) Close() {
-	log.Debug("DHCPv6 RA: closing")
+	log.Debug("dhcpv6 ra: closing")
 
 	ra.stop.Store(1)
 

internal/dhcpd/v4.go

@@ -36,7 +36,7 @@ func (s *v4Server) WriteDiskConfig6(c *V6ServerConf) {
 }
 
 // Return TRUE if IP address is within range [start..stop]
-func ip4InRange(start net.IP, stop net.IP, ip net.IP) bool {
+func ip4InRange(start, stop, ip net.IP) bool {
 	if len(start) != 4 || len(stop) != 4 {
 		return false
 	}
@@ -55,7 +55,7 @@ func (s *v4Server) ResetLeases(leases []*Lease) {
 		if l.Expiry.Unix() != leaseExpireStatic &&
 			!ip4InRange(s.conf.ipStart, s.conf.ipEnd, l.IP) {
 
-			log.Debug("DHCPv4: skipping a lease with IP %v: not within current IP range", l.IP)
+			log.Debug("dhcpv4: skipping a lease with IP %v: not within current IP range", l.IP)
 			continue
 		}
 
@@ -124,7 +124,7 @@ func (s *v4Server) blacklistLease(lease *Lease) {
 // Remove (swap) lease by index
 func (s *v4Server) leaseRemoveSwapByIndex(i int) {
 	s.ipAddrs[s.leases[i].IP[3]] = 0
-	log.Debug("DHCPv4: removed lease %s", s.leases[i].HWAddr)
+	log.Debug("dhcpv4: removed lease %s", s.leases[i].HWAddr)
 
 	n := len(s.leases)
 	if i != n-1 {
@@ -168,7 +168,7 @@ func (s *v4Server) rmDynamicLease(lease Lease) error {
 func (s *v4Server) addLease(l *Lease) {
 	s.leases = append(s.leases, l)
 	s.ipAddrs[l.IP[3]] = 1
-	log.Debug("DHCPv4: added lease %s <-> %s", l.IP, l.HWAddr)
+	log.Debug("dhcpv4: added lease %s <-> %s", l.IP, l.HWAddr)
 }
 
 // Remove a lease with the same properties
@@ -178,8 +178,7 @@ func (s *v4Server) rmLease(lease Lease) error {
 
 			if !bytes.Equal(l.HWAddr, lease.HWAddr) ||
 				l.Hostname != lease.Hostname {
-
-				return fmt.Errorf("Lease not found")
+				return fmt.Errorf("lease not found")
 			}
 
 			s.leaseRemoveSwapByIndex(i)
@@ -238,7 +237,6 @@ func (s *v4Server) RemoveStaticLease(l Lease) error {
 // Send ICMP to the specified machine
 // Return TRUE if it doesn't reply, which probably means that the IP is available
 func (s *v4Server) addrAvailable(target net.IP) bool {
-
 	if s.conf.ICMPTimeout == 0 {
 		return true
 	}
@@ -256,15 +254,15 @@ func (s *v4Server) addrAvailable(target net.IP) bool {
 	pinger.OnRecv = func(pkt *ping.Packet) {
 		reply = true
 	}
-	log.Debug("DHCPv4: Sending ICMP Echo to %v", target)
+	log.Debug("dhcpv4: Sending ICMP Echo to %v", target)
 	pinger.Run()
 
 	if reply {
-		log.Info("DHCPv4: IP conflict: %v is already used by another device", target)
+		log.Info("dhcpv4: IP conflict: %v is already used by another device", target)
 		return false
 	}
 
-	log.Debug("DHCPv4: ICMP procedure is complete: %v", target)
+	log.Debug("dhcpv4: ICMP procedure is complete: %v", target)
 	return true
 }
 
@@ -337,7 +335,7 @@ func (s *v4Server) commitLease(l *Lease) {
 }
 
 // Process Discover request and return lease
-func (s *v4Server) processDiscover(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) *Lease {
+func (s *v4Server) processDiscover(req, resp *dhcpv4.DHCPv4) *Lease {
 	mac := req.ClientHWAddr
 
 	s.leasesLock.Lock()
@@ -349,7 +347,7 @@ func (s *v4Server) processDiscover(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) *Lea
 		for lease == nil {
 			lease = s.reserveLease(mac)
 			if lease == nil {
-				log.Debug("DHCPv4: No more IP addresses")
+				log.Debug("dhcpv4: No more IP addresses")
 				if toStore {
 					s.conf.notify(LeaseChangedDBStore)
 				}
@@ -372,7 +370,7 @@ func (s *v4Server) processDiscover(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) *Lea
 		reqIP := req.Options.Get(dhcpv4.OptionRequestedIPAddress)
 		if len(reqIP) != 0 &&
 			!bytes.Equal(reqIP, lease.IP) {
-			log.Debug("DHCPv4: different RequestedIP: %v != %v", reqIP, lease.IP)
+			log.Debug("dhcpv4: different RequestedIP: %v != %v", reqIP, lease.IP)
 		}
 	}
 
@@ -407,12 +405,11 @@ func (o *optFQDN) ToBytes() []byte {
 
 	copy(b[i:], []byte(o.name))
 	return b
-
 }
 
 // Process Request request and return lease
 // Return false if we don't need to reply
-func (s *v4Server) processRequest(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) (*Lease, bool) {
+func (s *v4Server) processRequest(req, resp *dhcpv4.DHCPv4) (*Lease, bool) {
 	var lease *Lease
 	mac := req.ClientHWAddr
 	hostname := req.Options.Get(dhcpv4.OptionHostName)
@@ -424,12 +421,12 @@ func (s *v4Server) processRequest(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) (*Lea
 	sid := req.Options.Get(dhcpv4.OptionServerIdentifier)
 	if len(sid) != 0 &&
 		!bytes.Equal(sid, s.conf.dnsIPAddrs[0]) {
-		log.Debug("DHCPv4: Bad OptionServerIdentifier in Request message for %s", mac)
+		log.Debug("dhcpv4: Bad OptionServerIdentifier in Request message for %s", mac)
 		return nil, false
 	}
 
 	if len(reqIP) != 4 {
-		log.Debug("DHCPv4: Bad OptionRequestedIPAddress in Request message for %s", mac)
+		log.Debug("dhcpv4: Bad OptionRequestedIPAddress in Request message for %s", mac)
 		return nil, false
 	}
 
@@ -438,7 +435,7 @@ func (s *v4Server) processRequest(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) (*Lea
 		if bytes.Equal(l.HWAddr, mac) {
 			if !bytes.Equal(l.IP, reqIP) {
 				s.leasesLock.Unlock()
-				log.Debug("DHCPv4: Mismatched OptionRequestedIPAddress in Request message for %s", mac)
+				log.Debug("dhcpv4: Mismatched OptionRequestedIPAddress in Request message for %s", mac)
 				return nil, true
 			}
 
@@ -449,7 +446,7 @@ func (s *v4Server) processRequest(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) (*Lea
 	s.leasesLock.Unlock()
 
 	if lease == nil {
-		log.Debug("DHCPv4: No lease for %s", mac)
+		log.Debug("dhcpv4: No lease for %s", mac)
 		return nil, true
 	}
 
@@ -475,8 +472,7 @@ func (s *v4Server) processRequest(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) (*Lea
 // Return 1: OK
 // Return 0: error; reply with Nak
 // Return -1: error; don't reply
-func (s *v4Server) process(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) int {
-
+func (s *v4Server) process(req, resp *dhcpv4.DHCPv4) int {
 	var lease *Lease
 
 	resp.UpdateOption(dhcpv4.OptServerIdentifier(s.conf.dnsIPAddrs[0]))
@@ -519,7 +515,7 @@ func (s *v4Server) process(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) int {
 // client(0.0.0.0:68) -> (Request:ClientMAC,Type=Request,ClientID,ReqIP||ClientIP,HostName,ServerID,ParamReqList) -> server(255.255.255.255:67)
 // client(255.255.255.255:68) <- (Reply:YourIP,ClientMAC,Type=ACK,ServerID,SubnetMask,LeaseTime) <- server(<IP>:67)
 func (s *v4Server) packetHandler(conn net.PacketConn, peer net.Addr, req *dhcpv4.DHCPv4) {
-	log.Debug("DHCPv4: received message: %s", req.Summary())
+	log.Debug("dhcpv4: received message: %s", req.Summary())
 
 	switch req.MessageType() {
 	case dhcpv4.MessageTypeDiscover,
@@ -527,18 +523,18 @@ func (s *v4Server) packetHandler(conn net.PacketConn, peer net.Addr, req *dhcpv4
 		//
 
 	default:
-		log.Debug("DHCPv4: unsupported message type %d", req.MessageType())
+		log.Debug("dhcpv4: unsupported message type %d", req.MessageType())
 		return
 	}
 
 	resp, err := dhcpv4.NewReplyFromRequest(req)
 	if err != nil {
-		log.Debug("DHCPv4: dhcpv4.New: %s", err)
+		log.Debug("dhcpv4: dhcpv4.New: %s", err)
 		return
 	}
 
 	if len(req.ClientHWAddr) != 6 {
-		log.Debug("DHCPv4: Invalid ClientHWAddr")
+		log.Debug("dhcpv4: Invalid ClientHWAddr")
 		return
 	}
 
@@ -549,33 +545,74 @@ func (s *v4Server) packetHandler(conn net.PacketConn, peer net.Addr, req *dhcpv4
 		resp.Options.Update(dhcpv4.OptMessageType(dhcpv4.MessageTypeNak))
 	}
 
-	log.Debug("DHCPv4: sending: %s", resp.Summary())
+	log.Debug("dhcpv4: sending: %s", resp.Summary())
 
 	_, err = conn.WriteTo(resp.ToBytes(), peer)
 	if err != nil {
-		log.Error("DHCPv4: conn.Write to %s failed: %s", peer, err)
+		log.Error("dhcpv4: conn.Write to %s failed: %s", peer, err)
 		return
 	}
 }
 
-// Start - start server
+// ifaceIPv4Addrs returns the interface's IPv4 addresses.
+func ifaceIPv4Addrs(iface *net.Interface) (ips []net.IP, err error) {
+	addrs, err := iface.Addrs()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, a := range addrs {
+		ipnet, ok := a.(*net.IPNet)
+		if !ok {
+			continue
+		}
+
+		if ip := ipnet.IP.To4(); ip != nil {
+			ips = append(ips, ip)
+		}
+	}
+
+	return ips, nil
+}
+
+// Start starts the IPv4 DHCP server.
 func (s *v4Server) Start() error {
 	if !s.conf.Enabled {
 		return nil
 	}
 
-	iface, err := net.InterfaceByName(s.conf.InterfaceName)
+	ifaceName := s.conf.InterfaceName
+	iface, err := net.InterfaceByName(ifaceName)
 	if err != nil {
-		return fmt.Errorf("DHCPv4: Couldn't find interface by name %s: %s", s.conf.InterfaceName, err)
+		return fmt.Errorf("dhcpv4: finding interface %s by name: %w", ifaceName, err)
 	}
 
-	log.Debug("DHCPv4: starting...")
-	s.conf.dnsIPAddrs = getIfaceIPv4(*iface)
-	if len(s.conf.dnsIPAddrs) == 0 {
-		log.Debug("DHCPv4: no IPv6 address for interface %s", iface.Name)
-		return nil
+	log.Debug("dhcpv4: starting...")
+
+	dnsIPAddrs, err := ifaceIPv4Addrs(iface)
+	if err != nil {
+		return fmt.Errorf("dhcpv4: getting ipv4 addrs for iface %s: %w", ifaceName, err)
 	}
 
+	switch len(dnsIPAddrs) {
+	case 0:
+		log.Debug("dhcpv4: no ipv4 address for interface %s", iface.Name)
+
+		return nil
+	case 1:
+		// Some Android devices use 8.8.8.8 if there is no secondary DNS
+		// server.  Fix that by setting the secondary DNS address to our
+		// address as well.
+		//
+		// See https://github.com/AdguardTeam/AdGuardHome/issues/1708.
+		log.Debug("dhcpv4: setting secondary dns ip to iself for interface %s", iface.Name)
+		dnsIPAddrs = append(dnsIPAddrs, dnsIPAddrs[0])
+	default:
+		// Go on.
+	}
+
+	s.conf.dnsIPAddrs = dnsIPAddrs
+
 	laddr := &net.UDPAddr{
 		IP:   net.ParseIP("0.0.0.0"),
 		Port: dhcpv4.ServerPort,
@@ -585,12 +622,13 @@ func (s *v4Server) Start() error {
 		return err
 	}
 
-	log.Info("DHCPv4: listening")
+	log.Info("dhcpv4: listening")
 
 	go func() {
 		err = s.srv.Serve()
-		log.Debug("DHCPv4: srv.Serve: %s", err)
+		log.Debug("dhcpv4: srv.Serve: %s", err)
 	}()
+
 	return nil
 }
 
@@ -600,10 +638,10 @@ func (s *v4Server) Stop() {
 		return
 	}
 
-	log.Debug("DHCPv4: stopping")
+	log.Debug("dhcpv4: stopping")
 	err := s.srv.Close()
 	if err != nil {
-		log.Error("DHCPv4: srv.Close: %s", err)
+		log.Error("dhcpv4: srv.Close: %s", err)
 	}
 	// now s.srv.Serve() will return
 	s.srv = nil
@@ -621,31 +659,31 @@ func v4Create(conf V4ServerConf) (DHCPServer, error) {
 	var err error
 	s.conf.routerIP, err = parseIPv4(s.conf.GatewayIP)
 	if err != nil {
-		return s, fmt.Errorf("DHCPv4: %s", err)
+		return s, fmt.Errorf("dhcpv4: %w", err)
 	}
 
 	subnet, err := parseIPv4(s.conf.SubnetMask)
 	if err != nil || !isValidSubnetMask(subnet) {
-		return s, fmt.Errorf("DHCPv4: invalid subnet mask: %s", s.conf.SubnetMask)
+		return s, fmt.Errorf("dhcpv4: invalid subnet mask: %s", s.conf.SubnetMask)
 	}
 	s.conf.subnetMask = make([]byte, 4)
 	copy(s.conf.subnetMask, subnet)
 
 	s.conf.ipStart, err = parseIPv4(conf.RangeStart)
 	if s.conf.ipStart == nil {
-		return s, fmt.Errorf("DHCPv4: %s", err)
+		return s, fmt.Errorf("dhcpv4: %w", err)
 	}
 	if s.conf.ipStart[0] == 0 {
-		return s, fmt.Errorf("DHCPv4: invalid range start IP")
+		return s, fmt.Errorf("dhcpv4: invalid range start IP")
 	}
 
 	s.conf.ipEnd, err = parseIPv4(conf.RangeEnd)
 	if s.conf.ipEnd == nil {
-		return s, fmt.Errorf("DHCPv4: %s", err)
+		return s, fmt.Errorf("dhcpv4: %w", err)
 	}
 	if !net.IP.Equal(s.conf.ipStart[:3], s.conf.ipEnd[:3]) ||
 		s.conf.ipStart[3] > s.conf.ipEnd[3] {
-		return s, fmt.Errorf("DHCPv4: range end IP should match range start IP")
+		return s, fmt.Errorf("dhcpv4: range end IP should match range start IP")
 	}
 
 	if conf.LeaseDuration == 0 {
@@ -658,7 +696,7 @@ func v4Create(conf V4ServerConf) (DHCPServer, error) {
 	for _, o := range conf.Options {
 		code, val := parseOptionString(o)
 		if code == 0 {
-			log.Debug("DHCPv4: bad option string: %s", o)
+			log.Debug("dhcpv4: bad option string: %s", o)
 			continue
 		}
 

internal/dhcpd/v6.go

@@ -41,10 +41,11 @@ func (s *v6Server) WriteDiskConfig6(c *V6ServerConf) {
 
 // Return TRUE if IP address is within range [start..0xff]
 // nolint(staticcheck)
-func ip6InRange(start net.IP, ip net.IP) bool {
+func ip6InRange(start, ip net.IP) bool {
 	if len(start) != 16 {
 		return false
 	}
+	//lint:ignore SA1021 TODO(e.burkov): Ignore this for now, think about using masks.
 	if !bytes.Equal(start[:15], ip[:15]) {
 		return false
 	}
@@ -72,12 +73,10 @@ func (s *v6Server) GetLeases(flags int) []Lease {
 	var result []Lease
 	s.leasesLock.Lock()
 	for _, lease := range s.leases {
-
 		if lease.Expiry.Unix() == leaseExpireStatic {
 			if (flags & LeasesStatic) != 0 {
 				result = append(result, *lease)
 			}
-
 		} else {
 			if (flags & LeasesDynamic) != 0 {
 				result = append(result, *lease)
@@ -214,8 +213,7 @@ func (s *v6Server) rmLease(lease Lease) error {
 
 			if !bytes.Equal(l.HWAddr, lease.HWAddr) ||
 				l.Hostname != lease.Hostname {
-
-				return fmt.Errorf("Lease not found")
+				return fmt.Errorf("lease not found")
 			}
 
 			s.leaseRemoveSwapByIndex(i)
@@ -302,7 +300,7 @@ func (s *v6Server) commitDynamicLease(l *Lease) {
 // Check Client ID
 func (s *v6Server) checkCID(msg *dhcpv6.Message) error {
 	if msg.Options.ClientID() == nil {
-		return fmt.Errorf("DHCPv6: no ClientID option in request")
+		return fmt.Errorf("dhcpv6: no ClientID option in request")
 	}
 	return nil
 }
@@ -317,7 +315,7 @@ func (s *v6Server) checkSID(msg *dhcpv6.Message) error {
 		dhcpv6.MessageTypeRebind:
 
 		if sid != nil {
-			return fmt.Errorf("DHCPv6: drop packet: ServerID option in message %s", msg.Type().String())
+			return fmt.Errorf("dhcpv6: drop packet: ServerID option in message %s", msg.Type().String())
 		}
 
 	case dhcpv6.MessageTypeRequest,
@@ -326,10 +324,10 @@ func (s *v6Server) checkSID(msg *dhcpv6.Message) error {
 		dhcpv6.MessageTypeDecline:
 
 		if sid == nil {
-			return fmt.Errorf("DHCPv6: drop packet: no ServerID option in message %s", msg.Type().String())
+			return fmt.Errorf("dhcpv6: drop packet: no ServerID option in message %s", msg.Type().String())
 		}
 		if !sid.Equal(s.sid) {
-			return fmt.Errorf("DHCPv6: drop packet: mismatched ServerID option in message %s: %s",
+			return fmt.Errorf("dhcpv6: drop packet: mismatched ServerID option in message %s: %s",
 				msg.Type().String(), sid.String())
 		}
 	}
@@ -371,7 +369,7 @@ func (s *v6Server) commitLease(msg *dhcpv6.Message, lease *Lease) time.Duration
 		//
 
 	case dhcpv6.MessageTypeConfirm:
-		lifetime = lease.Expiry.Sub(time.Now())
+		lifetime = time.Until(lease.Expiry)
 
 	case dhcpv6.MessageTypeRequest,
 		dhcpv6.MessageTypeRenew,
@@ -385,7 +383,7 @@ func (s *v6Server) commitLease(msg *dhcpv6.Message, lease *Lease) time.Duration
 }
 
 // Find a lease associated with MAC and prepare response
-func (s *v6Server) process(msg *dhcpv6.Message, req dhcpv6.DHCPv6, resp dhcpv6.DHCPv6) bool {
+func (s *v6Server) process(msg *dhcpv6.Message, req, resp dhcpv6.DHCPv6) bool {
 	switch msg.Type() {
 	case dhcpv6.MessageTypeSolicit,
 		dhcpv6.MessageTypeRequest,
@@ -539,24 +537,25 @@ func (s *v6Server) packetHandler(conn net.PacketConn, peer net.Addr, req dhcpv6.
 	}
 }
 
-// Get IPv6 address list
-func getIfaceIPv6(iface net.Interface) []net.IP {
+// ifaceIPv6Addrs returns the interface's IPv6 addresses.
+func ifaceIPv6Addrs(iface *net.Interface) (ips []net.IP, err error) {
 	addrs, err := iface.Addrs()
 	if err != nil {
-		return nil
+		return nil, err
 	}
 
-	var res []net.IP
 	for _, a := range addrs {
 		ipnet, ok := a.(*net.IPNet)
 		if !ok {
 			continue
 		}
-		if ipnet.IP.To4() == nil {
-			res = append(res, ipnet.IP)
+
+		if ip := ipnet.IP.To16(); ip != nil {
+			ips = append(ips, ip)
 		}
 	}
-	return res
+
+	return ips, nil
 }
 
 // initialize RA module
@@ -580,23 +579,40 @@ func (s *v6Server) initRA(iface *net.Interface) error {
 	return s.ra.Init()
 }
 
-// Start - start server
+// Start starts the IPv6 DHCP server.
 func (s *v6Server) Start() error {
 	if !s.conf.Enabled {
 		return nil
 	}
 
-	iface, err := net.InterfaceByName(s.conf.InterfaceName)
+	ifaceName := s.conf.InterfaceName
+	iface, err := net.InterfaceByName(ifaceName)
 	if err != nil {
-		return wrapErrPrint(err, "Couldn't find interface by name %s", s.conf.InterfaceName)
+		return fmt.Errorf("dhcpv6: finding interface %s by name: %w", ifaceName, err)
 	}
 
-	s.conf.dnsIPAddrs = getIfaceIPv6(*iface)
-	if len(s.conf.dnsIPAddrs) == 0 {
-		log.Debug("DHCPv6: no IPv6 address for interface %s", iface.Name)
-		return nil
+	log.Debug("dhcpv4: starting...")
+
+	dnsIPAddrs, err := ifaceIPv6Addrs(iface)
+	if err != nil {
+		return fmt.Errorf("dhcpv6: getting ipv6 addrs for iface %s: %w", ifaceName, err)
 	}
 
+	switch len(dnsIPAddrs) {
+	case 0:
+		log.Debug("dhcpv6: no ipv6 address for interface %s", iface.Name)
+
+		return nil
+	case 1:
+		// See the comment in (*v4Server).Start.
+		log.Debug("dhcpv6: setting secondary dns ip to iself for interface %s", iface.Name)
+		dnsIPAddrs = append(dnsIPAddrs, dnsIPAddrs[0])
+	default:
+		// Go on.
+	}
+
+	s.conf.dnsIPAddrs = dnsIPAddrs
+
 	err = s.initRA(iface)
 	if err != nil {
 		return err
@@ -611,7 +627,7 @@ func (s *v6Server) Start() error {
 	log.Debug("DHCPv6: starting...")
 
 	if len(iface.HardwareAddr) != 6 {
-		return fmt.Errorf("DHCPv6: invalid MAC %s", iface.HardwareAddr)
+		return fmt.Errorf("dhcpv6: invalid MAC %s", iface.HardwareAddr)
 	}
 	s.sid = dhcpv6.Duid{
 		Type:          dhcpv6.DUID_LLT,
@@ -666,7 +682,7 @@ func v6Create(conf V6ServerConf) (DHCPServer, error) {
 
 	s.conf.ipStart = net.ParseIP(conf.RangeStart)
 	if s.conf.ipStart == nil || s.conf.ipStart.To16() == nil {
-		return s, fmt.Errorf("DHCPv6: invalid range-start IP: %s", conf.RangeStart)
+		return s, fmt.Errorf("dhcpv6: invalid range-start IP: %s", conf.RangeStart)
 	}
 
 	if conf.LeaseDuration == 0 {

internal/dnsfilter/README.md

@@ -22,12 +22,12 @@ func main() {
     res, err := filter.CheckHost(host)
     if err != nil {
         // temporary failure
-        log.Fatalf("Failed to check host '%s': %s", host, err)
+        log.Fatalf("Failed to check host %q: %s", host, err)
     }
     if res.IsFiltered {
-        log.Printf("Host %s is filtered, reason - '%s', matched rule: '%s'", host, res.Reason, res.Rule)
+        log.Printf("Host %s is filtered, reason - %q, matched rule: %q", host, res.Reason, res.Rule)
     } else {
-        log.Printf("Host %s is not filtered, reason - '%s'", host, res.Reason)
+        log.Printf("Host %s is not filtered, reason - %q", host, res.Reason)
     }
 }
 ```
@@ -59,12 +59,12 @@ func main() {
     res, err := filter.CheckHost(host)
     if err != nil {
         // temporary failure
-        log.Fatalf("Failed to check host '%s': %s", host, err)
+        log.Fatalf("Failed to check host %q: %s", host, err)
     }
     if res.IsFiltered {
-        log.Printf("Host %s is filtered, reason - '%s', matched rule: '%s'", host, res.Reason, res.Rule)
+        log.Printf("Host %s is filtered, reason - %q, matched rule: %q", host, res.Reason, res.Rule)
     } else {
-        log.Printf("Host %s is not filtered, reason - '%s'", host, res.Reason)
+        log.Printf("Host %s is not filtered, reason - %q", host, res.Reason)
     }
 }
 ```

internal/dnsfilter/dnsfilter.go

@@ -1,3 +1,4 @@
+// Package dnsfilter implements a DNS filter.
 package dnsfilter
 
 import (
@@ -11,7 +12,7 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/dnsproxy/upstream"
 	"github.com/AdguardTeam/golibs/cache"
 	"github.com/AdguardTeam/golibs/log"
@@ -199,7 +200,7 @@ func (d *Dnsfilter) WriteDiskConfig(c *Config) {
 // SetFilters - set new filters (synchronously or asynchronously)
 // When filters are set asynchronously, the old filters continue working until the new filters are ready.
 //  In this case the caller must ensure that the old filter files are intact.
-func (d *Dnsfilter) SetFilters(blockFilters []Filter, allowFilters []Filter, async bool) error {
+func (d *Dnsfilter) SetFilters(blockFilters, allowFilters []Filter, async bool) error {
 	if async {
 		params := filtersInitializerParams{
 			allowFilters: allowFilters,
@@ -281,7 +282,7 @@ type Result struct {
 	CanonName string `json:",omitempty"` // CNAME value
 
 	// for RewriteEtcHosts:
-	ReverseHost string `json:",omitempty"`
+	ReverseHosts []string `json:",omitempty"`
 
 	// for ReasonRewrite & RewriteEtcHosts:
 	IPList []net.IP `json:",omitempty"` // list of IP addresses
@@ -325,18 +326,9 @@ func (d *Dnsfilter) CheckHost(host string, qtype uint16, setts *RequestFiltering
 	// Now check the hosts file -- do we have any rules for it?
 	// just like DNS rewrites, it has higher priority than filtering rules.
 	if d.Config.AutoHosts != nil {
-		ips := d.Config.AutoHosts.Process(host, qtype)
-		if ips != nil {
-			result.Reason = RewriteEtcHosts
-			result.IPList = ips
-			return result, nil
-		}
-
-		revHost := d.Config.AutoHosts.ProcessReverse(host, qtype)
-		if len(revHost) != 0 {
-			result.Reason = RewriteEtcHosts
-			result.ReverseHost = revHost + "."
-			return result, nil
+		matched, err := d.checkAutoHosts(host, qtype, &result)
+		if matched {
+			return result, err
 		}
 	}
 
@@ -401,6 +393,31 @@ func (d *Dnsfilter) CheckHost(host string, qtype uint16, setts *RequestFiltering
 	return Result{}, nil
 }
 
+func (d *Dnsfilter) checkAutoHosts(host string, qtype uint16, result *Result) (matched bool, err error) {
+	ips := d.Config.AutoHosts.Process(host, qtype)
+	if ips != nil {
+		result.Reason = RewriteEtcHosts
+		result.IPList = ips
+
+		return true, nil
+	}
+
+	revHosts := d.Config.AutoHosts.ProcessReverse(host, qtype)
+	if len(revHosts) != 0 {
+		result.Reason = RewriteEtcHosts
+
+		// TODO(a.garipov): Optimize this with a buffer.
+		result.ReverseHosts = make([]string, len(revHosts))
+		for i := range revHosts {
+			result.ReverseHosts[i] = revHosts[i] + "."
+		}
+
+		return true, nil
+	}
+
+	return false, nil
+}
+
 // Process rewrites table
 // . Find CNAME for a domain name (exact match or by wildcard)
 //  . if found and CNAME equals to domain name - this is an exception;  exit
@@ -481,13 +498,10 @@ func matchBlockedServicesRules(host string, svcs []ServiceEntry) Result {
 // Adding rule and matching against the rules
 //
 
-// Return TRUE if file exists
+// fileExists returns true if file exists.
 func fileExists(fn string) bool {
 	_, err := os.Stat(fn)
-	if err != nil {
-		return false
-	}
-	return true
+	return err == nil
 }
 
 func createFilteringEngine(filters []Filter) (*filterlist.RuleStorage, *urlfilter.DNSEngine, error) {
@@ -501,19 +515,18 @@ func createFilteringEngine(filters []Filter) (*filterlist.RuleStorage, *urlfilte
 				RulesText:      string(f.Data),
 				IgnoreCosmetic: true,
 			}
-
 		} else if !fileExists(f.FilePath) {
 			list = &filterlist.StringRuleList{
 				ID:             int(f.ID),
 				IgnoreCosmetic: true,
 			}
-
 		} else if runtime.GOOS == "windows" {
 			// On Windows we don't pass a file to urlfilter because
-			//  it's difficult to update this file while it's being used.
+			// it's difficult to update this file while it's being
+			// used.
 			data, err := ioutil.ReadFile(f.FilePath)
 			if err != nil {
-				return nil, nil, fmt.Errorf("ioutil.ReadFile(): %s: %s", f.FilePath, err)
+				return nil, nil, fmt.Errorf("ioutil.ReadFile(): %s: %w", f.FilePath, err)
 			}
 			list = &filterlist.StringRuleList{
 				ID:             int(f.ID),
@@ -525,7 +538,7 @@ func createFilteringEngine(filters []Filter) (*filterlist.RuleStorage, *urlfilte
 			var err error
 			list, err = filterlist.NewFileRuleList(int(f.ID), f.FilePath, true)
 			if err != nil {
-				return nil, nil, fmt.Errorf("filterlist.NewFileRuleList(): %s: %s", f.FilePath, err)
+				return nil, nil, fmt.Errorf("filterlist.NewFileRuleList(): %s: %w", f.FilePath, err)
 			}
 		}
 		listArray = append(listArray, list)
@@ -533,13 +546,13 @@ func createFilteringEngine(filters []Filter) (*filterlist.RuleStorage, *urlfilte
 
 	rulesStorage, err := filterlist.NewRuleStorage(listArray)
 	if err != nil {
-		return nil, nil, fmt.Errorf("filterlist.NewRuleStorage(): %s", err)
+		return nil, nil, fmt.Errorf("filterlist.NewRuleStorage(): %w", err)
 	}
 	filteringEngine := urlfilter.NewDNSEngine(rulesStorage)
 	return rulesStorage, filteringEngine, nil
 }
 
-// Initialize urlfilter objects
+// Initialize urlfilter objects.
 func (d *Dnsfilter) initFiltering(allowFilters, blockFilters []Filter) error {
 	rulesStorage, filteringEngine, err := createFilteringEngine(blockFilters)
 	if err != nil {
@@ -565,7 +578,8 @@ func (d *Dnsfilter) initFiltering(allowFilters, blockFilters []Filter) error {
 	return nil
 }
 
-// matchHost is a low-level way to check only if hostname is filtered by rules, skipping expensive safebrowsing and parental lookups
+// matchHost is a low-level way to check only if hostname is filtered by rules,
+// skipping expensive safebrowsing and parental lookups.
 func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringSettings) (Result, error) {
 	d.engineLock.RLock()
 	// Keep in mind that this lock must be held no just when calling Match()
@@ -590,7 +604,7 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringS
 				rule = rr.HostRulesV6[0]
 			}
 
-			log.Debug("Filtering: found whitelist rule for host '%s': '%s'  list_id: %d",
+			log.Debug("Filtering: found whitelist rule for host %q: %q  list_id: %d",
 				host, rule.Text(), rule.GetFilterListID())
 			res := makeResult(rule, NotFilteredWhiteList)
 			return res, nil
@@ -607,7 +621,7 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringS
 	}
 
 	if rr.NetworkRule != nil {
-		log.Debug("Filtering: found rule for host '%s': '%s'  list_id: %d",
+		log.Debug("Filtering: found rule for host %q: %q  list_id: %d",
 			host, rr.NetworkRule.Text(), rr.NetworkRule.GetFilterListID())
 		reason := FilteredBlackList
 		if rr.NetworkRule.Whitelist {
@@ -619,7 +633,7 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringS
 
 	if qtype == dns.TypeA && rr.HostRulesV4 != nil {
 		rule := rr.HostRulesV4[0] // note that we process only 1 matched rule
-		log.Debug("Filtering: found rule for host '%s': '%s'  list_id: %d",
+		log.Debug("Filtering: found rule for host %q: %q  list_id: %d",
 			host, rule.Text(), rule.GetFilterListID())
 		res := makeResult(rule, FilteredBlackList)
 		res.IP = rule.IP.To4()
@@ -628,7 +642,7 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringS
 
 	if qtype == dns.TypeAAAA && rr.HostRulesV6 != nil {
 		rule := rr.HostRulesV6[0] // note that we process only 1 matched rule
-		log.Debug("Filtering: found rule for host '%s': '%s'  list_id: %d",
+		log.Debug("Filtering: found rule for host %q: %q  list_id: %d",
 			host, rule.Text(), rule.GetFilterListID())
 		res := makeResult(rule, FilteredBlackList)
 		res.IP = rule.IP
@@ -644,7 +658,7 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringS
 		} else if rr.HostRulesV6 != nil {
 			rule = rr.HostRulesV6[0]
 		}
-		log.Debug("Filtering: found rule for host '%s': '%s'  list_id: %d",
+		log.Debug("Filtering: found rule for host %q: %q  list_id: %d",
 			host, rule.Text(), rule.GetFilterListID())
 		res := makeResult(rule, FilteredBlackList)
 		res.IP = net.IP{}
@@ -666,21 +680,18 @@ func makeResult(rule rules.Rule, reason Reason) Result {
 	return res
 }
 
-// InitModule() - manually initialize blocked services map
+// InitModule manually initializes blocked services map.
 func InitModule() {
 	initBlockedServices()
 }
 
-// New creates properly initialized DNS Filter that is ready to be used
+// New creates properly initialized DNS Filter that is ready to be used.
 func New(c *Config, blockFilters []Filter) *Dnsfilter {
-
 	if c != nil {
 		cacheConf := cache.Config{
 			EnableLRU: true,
 		}
 
-		// initialize objects only once
-
 		if gctx.safebrowsingCache == nil {
 			cacheConf.MaxSize = c.SafeBrowsingCacheSize
 			gctx.safebrowsingCache = cache.New(cacheConf)
@@ -713,7 +724,7 @@ func New(c *Config, blockFilters []Filter) *Dnsfilter {
 	bsvcs := []string{}
 	for _, s := range d.BlockedServices {
 		if !BlockedSvcKnown(s) {
-			log.Debug("skipping unknown blocked-service '%s'", s)
+			log.Debug("skipping unknown blocked-service %q", s)
 			continue
 		}
 		bsvcs = append(bsvcs, s)
@@ -750,7 +761,7 @@ func (d *Dnsfilter) Start() {
 // stats
 //
 
-// GetStats return dns filtering stats since startup
+// GetStats return dns filtering stats since startup.
 func (d *Dnsfilter) GetStats() Stats {
 	return gctx.stats
 }

internal/dnsfilter/dnsfilter_test.go

@@ -3,9 +3,6 @@ package dnsfilter
 import (
 	"fmt"
 	"net"
-	"os"
-	"path"
-	"runtime"
 	"testing"
 
 	"github.com/AdguardTeam/urlfilter/rules"
@@ -36,13 +33,6 @@ func purgeCaches() {
 	}
 }
 
-func _Func() string {
-	pc := make([]uintptr, 10) // at least 1 entry needed
-	runtime.Callers(2, pc)
-	f := runtime.FuncForPC(pc[0])
-	return path.Base(f.Name())
-}
-
 func NewForTest(c *Config, filters []Filter) *Dnsfilter {
 	setts = RequestFilteringSettings{}
 	setts.FilteringEnabled = true
@@ -71,7 +61,7 @@ func (d *Dnsfilter) checkMatch(t *testing.T, hostname string) {
 	}
 }
 
-func (d *Dnsfilter) checkMatchIP(t *testing.T, hostname string, ip string, qtype uint16) {
+func (d *Dnsfilter) checkMatchIP(t *testing.T, hostname, ip string, qtype uint16) {
 	t.Helper()
 	ret, err := d.CheckHost(hostname, qtype, &setts)
 	if err != nil {
@@ -107,7 +97,7 @@ func TestEtcHostsMatching(t *testing.T) {
 ::1 host2
 `,
 		addr, addr6)
-	filters := []Filter{Filter{
+	filters := []Filter{{
 		ID: 0, Data: []byte(text),
 	}}
 	d := NewForTest(nil, filters)
@@ -351,11 +341,15 @@ func TestParentalControl(t *testing.T) {
 
 // FILTERING
 
-var blockingRules = "||example.org^\n"
-var whitelistRules = "||example.org^\n@@||test.example.org\n"
-var importantRules = "@@||example.org^\n||test.example.org^$important\n"
-var regexRules = "/example\\.org/\n@@||test.example.org^\n"
-var maskRules = "test*.example.org^\nexam*.com\n"
+const nl = "\n"
+
+const (
+	blockingRules  = `||example.org^` + nl
+	whitelistRules = `||example.org^` + nl + `@@||test.example.org` + nl
+	importantRules = `@@||example.org^` + nl + `||test.example.org^$important` + nl
+	regexRules     = `/example\.org/` + nl + `@@||test.example.org^` + nl
+	maskRules      = `test*.example.org^` + nl + `exam*.com` + nl
+)
 
 var tests = []struct {
 	testname   string
@@ -406,7 +400,7 @@ var tests = []struct {
 func TestMatching(t *testing.T) {
 	for _, test := range tests {
 		t.Run(fmt.Sprintf("%s-%s", test.testname, test.hostname), func(t *testing.T) {
-			filters := []Filter{Filter{
+			filters := []Filter{{
 				ID: 0, Data: []byte(test.rules),
 			}}
 			d := NewForTest(nil, filters)
@@ -430,14 +424,14 @@ func TestWhitelist(t *testing.T) {
 	rules := `||host1^
 ||host2^
 `
-	filters := []Filter{Filter{
+	filters := []Filter{{
 		ID: 0, Data: []byte(rules),
 	}}
 
 	whiteRules := `||host1^
 ||host3^
 `
-	whiteFilters := []Filter{Filter{
+	whiteFilters := []Filter{{
 		ID: 0, Data: []byte(whiteRules),
 	}}
 	d := NewForTest(nil, filters)
@@ -455,7 +449,6 @@ func TestWhitelist(t *testing.T) {
 	assert.True(t, err == nil)
 	assert.True(t, ret.IsFiltered && ret.Reason == FilteredBlackList)
 	assert.True(t, ret.Rule == "||host2^")
-
 }
 
 // CLIENT SETTINGS
@@ -476,7 +469,7 @@ func applyClientSettings(setts *RequestFilteringSettings) {
 //  then apply per-client settings and check behaviour once again
 func TestClientSettings(t *testing.T) {
 	var r Result
-	filters := []Filter{Filter{
+	filters := []Filter{{
 		ID: 0, Data: []byte("||example.org^\n"),
 	}}
 	d := NewForTest(&Config{ParentalEnabled: true, SafeBrowsingEnabled: false}, filters)
@@ -532,13 +525,6 @@ func TestClientSettings(t *testing.T) {
 	assert.True(t, r.IsFiltered && r.Reason == FilteredBlockedService)
 }
 
-func prepareTestDir() string {
-	const dir = "./agh-test"
-	_ = os.RemoveAll(dir)
-	_ = os.MkdirAll(dir, 0755)
-	return dir
-}
-
 // BENCHMARKS
 
 func BenchmarkSafeBrowsing(b *testing.B) {

internal/dnsfilter/safe_search.go

@@ -22,8 +22,7 @@ func (d *Dnsfilter) setCacheResult(cache cache.Cache, host string, res Result) i
 	var buf bytes.Buffer
 
 	expire := uint(time.Now().Unix()) + d.Config.CacheTime*60
-	var exp []byte
-	exp = make([]byte, 4)
+	exp := make([]byte, 4)
 	binary.BigEndian.PutUint32(exp, uint32(expire))
 	_, _ = buf.Write(exp)
 

internal/dnsfilter/sb_pc.go

@@ -22,11 +22,13 @@ import (
 	"golang.org/x/net/publicsuffix"
 )
 
-const dnsTimeout = 3 * time.Second
-const defaultSafebrowsingServer = "https://dns-family.adguard.com/dns-query"
-const defaultParentalServer = "https://dns-family.adguard.com/dns-query"
-const sbTXTSuffix = "sb.dns.adguard.com."
-const pcTXTSuffix = "pc.dns.adguard.com."
+const (
+	dnsTimeout                = 3 * time.Second
+	defaultSafebrowsingServer = `https://dns-family.adguard.com/dns-query`
+	defaultParentalServer     = `https://dns-family.adguard.com/dns-query`
+	sbTXTSuffix               = `sb.dns.adguard.com.`
+	pcTXTSuffix               = `pc.dns.adguard.com.`
+)
 
 func (d *Dnsfilter) initSecurityServices() error {
 	var err error
@@ -60,7 +62,7 @@ expire byte[4]
 hash byte[32]
 ...
 */
-func (c *sbCtx) setCache(prefix []byte, hashes []byte) {
+func (c *sbCtx) setCache(prefix, hashes []byte) {
 	d := make([]byte, 4+len(hashes))
 	expire := uint(time.Now().Unix()) + c.cacheTime*60
 	binary.BigEndian.PutUint32(d[:4], uint32(expire))
@@ -158,16 +160,28 @@ func hostnameToHashes(host string) map[[32]byte]string {
 
 // convert hash array to string
 func (c *sbCtx) getQuestion() string {
-	q := ""
+	b := &strings.Builder{}
+	encoder := hex.NewEncoder(b)
+
 	for hash := range c.hashToHost {
-		q += fmt.Sprintf("%s.", hex.EncodeToString(hash[0:2]))
+		// Ignore errors, since strings.(*Buffer).Write never returns
+		// errors.
+		//
+		// TODO(e.burkov, a.garipov): Find out and document why exactly
+		// this slice.
+		_, _ = encoder.Write(hash[0:2])
+		_, _ = b.WriteRune('.')
 	}
+
 	if c.svc == "SafeBrowsing" {
-		q += sbTXTSuffix
-	} else {
-		q += pcTXTSuffix
+		// See comment above.
+		_, _ = b.WriteString(sbTXTSuffix)
+		return b.String()
 	}
-	return q
+
+	// See comment above.
+	_, _ = b.WriteString(pcTXTSuffix)
+	return b.String()
 }
 
 // Find the target hash in TXT response

internal/dnsfilter/sb_pc_test.go

@@ -23,16 +23,16 @@ func TestSafeBrowsingHash(t *testing.T) {
 	assert.False(t, ok)
 
 	c := &sbCtx{
-		svc: "SafeBrowsing",
+		svc:        "SafeBrowsing",
+		hashToHost: hashes,
 	}
 
-	// test getQuestion()
-	c.hashToHost = hashes
 	q := c.getQuestion()
-	assert.True(t, strings.Index(q, "7a1b.") >= 0)
-	assert.True(t, strings.Index(q, "af5a.") >= 0)
-	assert.True(t, strings.Index(q, "eb11.") >= 0)
-	assert.True(t, strings.Index(q, "sb.dns.adguard.com.") > 0)
+
+	assert.True(t, strings.Contains(q, "7a1b."))
+	assert.True(t, strings.Contains(q, "af5a."))
+	assert.True(t, strings.Contains(q, "eb11."))
+	assert.True(t, strings.HasSuffix(q, "sb.dns.adguard.com."))
 }
 
 func TestSafeBrowsingCache(t *testing.T) {

internal/dnsforward/access.go

@@ -51,7 +51,7 @@ func (a *accessCtx) Init(allowedClients, disallowedClients, blockedHosts []strin
 	listArray = append(listArray, list)
 	rulesStorage, err := filterlist.NewRuleStorage(listArray)
 	if err != nil {
-		return fmt.Errorf("filterlist.NewRuleStorage(): %s", err)
+		return fmt.Errorf("filterlist.NewRuleStorage(): %w", err)
 	}
 	a.blockedHostsEngine = urlfilter.NewDNSEngine(rulesStorage)
 

internal/dnsforward/config.go

@@ -10,12 +10,11 @@ import (
 	"net/http"
 	"sort"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/dnsproxy/upstream"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
 )
 
 // FilteringConfig represents the DNS filtering configuration of AdGuard Home
@@ -252,14 +251,14 @@ func (s *Server) prepareUpstreamSettings() error {
 	upstreams = filterOutComments(upstreams)
 	upstreamConfig, err := proxy.ParseUpstreamsConfig(upstreams, s.conf.BootstrapDNS, DefaultTimeout)
 	if err != nil {
-		return fmt.Errorf("DNS: proxy.ParseUpstreamsConfig: %s", err)
+		return fmt.Errorf("dns: proxy.ParseUpstreamsConfig: %w", err)
 	}
 
 	if len(upstreamConfig.Upstreams) == 0 {
 		log.Info("Warning: no default upstream servers specified, using %v", defaultDNS)
 		uc, err := proxy.ParseUpstreamsConfig(defaultDNS, s.conf.BootstrapDNS, DefaultTimeout)
 		if err != nil {
-			return fmt.Errorf("DNS: failed to parse default upstreams: %v", err)
+			return fmt.Errorf("dns: failed to parse default upstreams: %v", err)
 		}
 		upstreamConfig.Upstreams = uc.Upstreams
 	}
@@ -300,13 +299,13 @@ func (s *Server) prepareTLS(proxyConfig *proxy.Config) error {
 	var err error
 	s.conf.cert, err = tls.X509KeyPair(s.conf.CertificateChainData, s.conf.PrivateKeyData)
 	if err != nil {
-		return errorx.Decorate(err, "Failed to parse TLS keypair")
+		return fmt.Errorf("failed to parse TLS keypair: %w", err)
 	}
 
 	if s.conf.StrictSNICheck {
 		x, err := x509.ParseCertificate(s.conf.cert.Certificate[0])
 		if err != nil {
-			return errorx.Decorate(err, "x509.ParseCertificate(): %s", err)
+			return fmt.Errorf("x509.ParseCertificate(): %w", err)
 		}
 		if len(x.DNSNames) != 0 {
 			s.conf.dnsNames = x.DNSNames

internal/dnsforward/dnsforward.go

@@ -1,3 +1,4 @@
+// Package dnsforward contains a DNS forwarding server.
 package dnsforward
 
 import (
@@ -8,13 +9,12 @@ import (
 	"sync"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/dhcpd"
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
-	"github.com/AdguardTeam/AdGuardHome/querylog"
-	"github.com/AdguardTeam/AdGuardHome/stats"
+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/querylog"
+	"github.com/AdguardTeam/AdGuardHome/internal/stats"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
 	"github.com/miekg/dns"
 )
 
@@ -181,12 +181,9 @@ func (s *Server) Prepare(config *ServerConfig) error {
 			s.conf.BlockingIPAddrv4 = net.ParseIP(s.conf.BlockingIPv4)
 			s.conf.BlockingIPAddrv6 = net.ParseIP(s.conf.BlockingIPv6)
 			if s.conf.BlockingIPAddrv4 == nil || s.conf.BlockingIPAddrv6 == nil {
-				return fmt.Errorf("DNS: invalid custom blocking IP address specified")
+				return fmt.Errorf("dns: invalid custom blocking IP address specified")
 			}
 		}
-		if s.conf.MaxGoroutines == 0 {
-			s.conf.MaxGoroutines = 50
-		}
 	}
 
 	// Set default values in the case if nothing is configured
@@ -249,7 +246,7 @@ func (s *Server) stopInternal() error {
 	if s.dnsProxy != nil {
 		err := s.dnsProxy.Stop()
 		if err != nil {
-			return errorx.Decorate(err, "could not stop the DNS server properly")
+			return fmt.Errorf("could not stop the DNS server properly: %w", err)
 		}
 	}
 
@@ -272,7 +269,7 @@ func (s *Server) Reconfigure(config *ServerConfig) error {
 	log.Print("Start reconfiguring the server")
 	err := s.stopInternal()
 	if err != nil {
-		return errorx.Decorate(err, "could not reconfigure the server")
+		return fmt.Errorf("could not reconfigure the server: %w", err)
 	}
 
 	// It seems that net.Listener.Close() doesn't close file descriptors right away.
@@ -281,12 +278,12 @@ func (s *Server) Reconfigure(config *ServerConfig) error {
 
 	err = s.Prepare(config)
 	if err != nil {
-		return errorx.Decorate(err, "could not reconfigure the server")
+		return fmt.Errorf("could not reconfigure the server: %w", err)
 	}
 
 	err = s.startInternal()
 	if err != nil {
-		return errorx.Decorate(err, "could not reconfigure the server")
+		return fmt.Errorf("could not reconfigure the server: %w", err)
 	}
 
 	return nil

internal/dnsforward/dnsforward_http.go

@@ -17,7 +17,7 @@ import (
 
 func httpError(r *http.Request, w http.ResponseWriter, code int, format string, args ...interface{}) {
 	text := fmt.Sprintf(format, args...)
-	log.Info("DNS: %s %s: %s", r.Method, r.URL, text)
+	log.Info("dns: %s %s: %s", r.Method, r.URL, text)
 	http.Error(w, text, code)
 }
 
@@ -102,7 +102,7 @@ func checkBootstrap(addr string) error {
 	}
 	_, err := upstream.NewResolver(addr, 0)
 	if err != nil {
-		return fmt.Errorf("invalid bootstrap server address: %s", err)
+		return fmt.Errorf("invalid bootstrap server address: %w", err)
 	}
 	return nil
 }
@@ -322,7 +322,7 @@ func separateUpstream(upstream string) (string, bool, error) {
 		// split domains and upstream string
 		domainsAndUpstream := strings.Split(strings.TrimPrefix(upstream, "[/"), "/]")
 		if len(domainsAndUpstream) != 2 {
-			return "", defaultUpstream, fmt.Errorf("wrong DNS upstream per domain specification: %s", upstream)
+			return "", defaultUpstream, fmt.Errorf("wrong dns upstream per domain specification: %s", upstream)
 		}
 
 		// split domains list and validate each one
@@ -357,7 +357,7 @@ func checkPlainDNS(upstream string) error {
 
 	_, err = strconv.ParseInt(port, 0, 64)
 	if err != nil {
-		return fmt.Errorf("%s is not a valid port: %s", port, err)
+		return fmt.Errorf("%s is not a valid port: %w", port, err)
 	}
 
 	return nil
@@ -405,7 +405,7 @@ func checkDNS(input string, bootstrap []string) error {
 	// separate upstream from domains list
 	input, defaultUpstream, err := separateUpstream(input)
 	if err != nil {
-		return fmt.Errorf("wrong upstream format: %s", err)
+		return fmt.Errorf("wrong upstream format: %w", err)
 	}
 
 	// No need to check this DNS server
@@ -414,17 +414,17 @@ func checkDNS(input string, bootstrap []string) error {
 	}
 
 	if _, err := validateUpstream(input); err != nil {
-		return fmt.Errorf("wrong upstream format: %s", err)
+		return fmt.Errorf("wrong upstream format: %w", err)
 	}
 
 	if len(bootstrap) == 0 {
 		bootstrap = defaultBootstrap
 	}
 
-	log.Debug("Checking if DNS %s works...", input)
+	log.Debug("checking if dns %s works...", input)
 	u, err := upstream.AddressToUpstream(input, upstream.Options{Bootstrap: bootstrap, Timeout: DefaultTimeout})
 	if err != nil {
-		return fmt.Errorf("failed to choose upstream for %s: %s", input, err)
+		return fmt.Errorf("failed to choose upstream for %s: %w", input, err)
 	}
 
 	req := dns.Msg{}
@@ -435,18 +435,18 @@ func checkDNS(input string, bootstrap []string) error {
 	}
 	reply, err := u.Exchange(&req)
 	if err != nil {
-		return fmt.Errorf("couldn't communicate with DNS server %s: %s", input, err)
+		return fmt.Errorf("couldn't communicate with dns server %s: %w", input, err)
 	}
 	if len(reply.Answer) != 1 {
-		return fmt.Errorf("DNS server %s returned wrong answer", input)
+		return fmt.Errorf("dns server %s returned wrong answer", input)
 	}
 	if t, ok := reply.Answer[0].(*dns.A); ok {
 		if !net.IPv4(8, 8, 8, 8).Equal(t.A) {
-			return fmt.Errorf("DNS server %s returned wrong answer: %v", input, t.A)
+			return fmt.Errorf("dns server %s returned wrong answer: %v", input, t.A)
 		}
 	}
 
-	log.Debug("DNS %s works OK", input)
+	log.Debug("dns %s works OK", input)
 	return nil
 }
 
@@ -462,7 +462,7 @@ func (s *Server) handleDOH(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if !s.IsRunning() {
-		httpError(r, w, http.StatusInternalServerError, "DNS server is not running")
+		httpError(r, w, http.StatusInternalServerError, "dns server is not running")
 		return
 	}
 

internal/dnsforward/dnsforward_test.go

@@ -18,10 +18,10 @@ import (
 	"testing"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 
-	"github.com/AdguardTeam/AdGuardHome/dhcpd"
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/dnsproxy/upstream"
 	"github.com/miekg/dns"
@@ -815,12 +815,12 @@ func sendTestMessageAsync(t *testing.T, conn *dns.Conn, g *sync.WaitGroup) {
 	req := createGoogleATestMessage()
 	err := conn.WriteMsg(req)
 	if err != nil {
-		t.Fatalf("cannot write message: %s", err)
+		panic(fmt.Sprintf("cannot write message: %s", err))
 	}
 
 	res, err := conn.ReadMsg()
 	if err != nil {
-		t.Fatalf("cannot read response to message: %s", err)
+		panic(fmt.Sprintf("cannot read response to message: %s", err))
 	}
 	assertGoogleAResponse(t, res)
 }
@@ -916,20 +916,23 @@ func publicKey(priv interface{}) interface{} {
 }
 
 func TestValidateUpstream(t *testing.T) {
-	invalidUpstreams := []string{"1.2.3.4.5",
+	invalidUpstreams := []string{
+		"1.2.3.4.5",
 		"123.3.7m",
 		"htttps://google.com/dns-query",
 		"[/host.com]tls://dns.adguard.com",
 		"[host.ru]#",
 	}
 
-	validDefaultUpstreams := []string{"1.1.1.1",
+	validDefaultUpstreams := []string{
+		"1.1.1.1",
 		"tls://1.1.1.1",
 		"https://dns.adguard.com/dns-query",
 		"sdns://AQMAAAAAAAAAFDE3Ni4xMDMuMTMwLjEzMDo1NDQzINErR_JS3PLCu_iZEIbq95zkSV2LFsigxDIuUso_OQhzIjIuZG5zY3J5cHQuZGVmYXVsdC5uczEuYWRndWFyZC5jb20",
 	}
 
-	validUpstreams := []string{"[/host.com/]1.1.1.1",
+	validUpstreams := []string{
+		"[/host.com/]1.1.1.1",
 		"[//]tls://1.1.1.1",
 		"[/www.host.com/]#",
 		"[/host.com/google.com/]8.8.8.8",
@@ -975,7 +978,8 @@ func TestValidateUpstreamsSet(t *testing.T) {
 	assert.Nil(t, err, "comments should not be validated")
 
 	// Set of valid upstreams. There is no default upstream specified
-	upstreamsSet = []string{"[/host.com/]1.1.1.1",
+	upstreamsSet = []string{
+		"[/host.com/]1.1.1.1",
 		"[//]tls://1.1.1.1",
 		"[/www.host.com/]#",
 		"[/host.com/google.com/]8.8.8.8",
@@ -1029,9 +1033,7 @@ func (d *testDHCP) Leases(flags int) []dhcpd.Lease {
 	l.Hostname = "localhost"
 	return []dhcpd.Lease{l}
 }
-func (d *testDHCP) SetOnLeaseChanged(onLeaseChanged dhcpd.OnLeaseChangedT) {
-	return
-}
+func (d *testDHCP) SetOnLeaseChanged(onLeaseChanged dhcpd.OnLeaseChangedT) {}
 
 func TestPTRResponseFromDHCPLeases(t *testing.T) {
 	dhcp := &testDHCP{}

internal/dnsforward/filter.go

@@ -1,12 +1,13 @@
 package dnsforward
 
 import (
+	"fmt"
 	"strings"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
+
 	"github.com/miekg/dns"
 )
 
@@ -49,29 +50,32 @@ func (s *Server) filterDNSRequest(ctx *dnsContext) (*dnsfilter.Result, error) {
 	res, err := s.dnsFilter.CheckHost(host, d.Req.Question[0].Qtype, ctx.setts)
 	if err != nil {
 		// Return immediately if there's an error
-		return nil, errorx.Decorate(err, "dnsfilter failed to check host '%s'", host)
-
+		return nil, fmt.Errorf("dnsfilter failed to check host %q: %w", host, err)
 	} else if res.IsFiltered {
-		log.Tracef("Host %s is filtered, reason - '%s', matched rule: '%s'", host, res.Reason, res.Rule)
+		log.Tracef("Host %s is filtered, reason - %q, matched rule: %q", host, res.Reason, res.Rule)
 		d.Res = s.genDNSFilterMessage(d, &res)
-
 	} else if res.Reason == dnsfilter.ReasonRewrite && len(res.CanonName) != 0 && len(res.IPList) == 0 {
 		ctx.origQuestion = d.Req.Question[0]
 		// resolve canonical name, not the original host name
 		d.Req.Question[0].Name = dns.Fqdn(res.CanonName)
-
-	} else if res.Reason == dnsfilter.RewriteEtcHosts && len(res.ReverseHost) != 0 {
-
+	} else if res.Reason == dnsfilter.RewriteEtcHosts && len(res.ReverseHosts) != 0 {
 		resp := s.makeResponse(req)
-		ptr := &dns.PTR{}
-		ptr.Hdr = dns.RR_Header{
-			Name:   req.Question[0].Name,
-			Rrtype: dns.TypePTR,
-			Ttl:    s.conf.BlockedResponseTTL,
-			Class:  dns.ClassINET,
+		for _, h := range res.ReverseHosts {
+			hdr := dns.RR_Header{
+				Name:   req.Question[0].Name,
+				Rrtype: dns.TypePTR,
+				Ttl:    s.conf.BlockedResponseTTL,
+				Class:  dns.ClassINET,
+			}
+
+			ptr := &dns.PTR{
+				Hdr: hdr,
+				Ptr: h,
+			}
+
+			resp.Answer = append(resp.Answer, ptr)
 		}
-		ptr.Ptr = res.ReverseHost
-		resp.Answer = append(resp.Answer, ptr)
+
 		d.Res = resp
 	} else if res.Reason == dnsfilter.ReasonRewrite || res.Reason == dnsfilter.RewriteEtcHosts {
 		resp := s.makeResponse(req)
@@ -136,7 +140,6 @@ func (s *Server) filterDNSResponse(ctx *dnsContext) (*dnsfilter.Result, error) {
 
 		if err != nil {
 			return nil, err
-
 		} else if res.IsFiltered {
 			d.Res = s.genDNSFilterMessage(d, &res)
 			log.Debug("DNSFwd: Matched %s by response: %s", d.Req.Question[0].Name, host)

internal/dnsforward/handle_dns.go

@@ -5,9 +5,9 @@ import (
 	"strings"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/dhcpd"
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/miekg/dns"

internal/dnsforward/ipset.go

@@ -5,7 +5,7 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/miekg/dns"
 )
@@ -31,13 +31,13 @@ func (c *ipsetCtx) init(ipsetConfig []string) {
 		it = strings.TrimSpace(it)
 		hostsAndNames := strings.Split(it, "/")
 		if len(hostsAndNames) != 2 {
-			log.Debug("IPSET: invalid value '%s'", it)
+			log.Debug("IPSET: invalid value %q", it)
 			continue
 		}
 
 		ipsetNames := strings.Split(hostsAndNames[1], ",")
 		if len(ipsetNames) == 0 {
-			log.Debug("IPSET: invalid value '%s'", it)
+			log.Debug("IPSET: invalid value %q", it)
 			continue
 		}
 		bad := false
@@ -49,7 +49,7 @@ func (c *ipsetCtx) init(ipsetConfig []string) {
 			}
 		}
 		if bad {
-			log.Debug("IPSET: invalid value '%s'", it)
+			log.Debug("IPSET: invalid value %q", it)
 			continue
 		}
 
@@ -58,7 +58,7 @@ func (c *ipsetCtx) init(ipsetConfig []string) {
 			host = strings.TrimSpace(host)
 			host = strings.ToLower(host)
 			if len(host) == 0 {
-				log.Debug("IPSET: invalid value '%s'", it)
+				log.Debug("IPSET: invalid value %q", it)
 				continue
 			}
 			c.ipsetList[host] = ipsetNames
@@ -131,7 +131,7 @@ func (c *ipsetCtx) process(ctx *dnsContext) int {
 				continue
 			}
 			if code != 0 {
-				log.Info("IPSET: ipset add:  code:%d  output:'%s'", code, out)
+				log.Info("IPSET: ipset add:  code:%d  output:%q", code, out)
 				continue
 			}
 			log.Debug("IPSET: added %s(%s) -> %s", host, ipStr, name)

internal/dnsforward/msg.go

@@ -5,7 +5,7 @@ import (
 	"net"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/miekg/dns"
 )
@@ -46,7 +46,6 @@ func (s *Server) genDNSFilterMessage(d *proxy.DNSContext, result *dnsfilter.Resu
 		if s.conf.BlockingMode == "null_ip" {
 			// it means that we should return 0.0.0.0 or :: for any blocked request
 			return s.makeResponseNullIP(m)
-
 		} else if s.conf.BlockingMode == "custom_ip" {
 			// means that we should return custom IP for any blocked request
 
@@ -56,12 +55,10 @@ func (s *Server) genDNSFilterMessage(d *proxy.DNSContext, result *dnsfilter.Resu
 			case dns.TypeAAAA:
 				return s.genAAAARecord(m, s.conf.BlockingIPAddrv6)
 			}
-
 		} else if s.conf.BlockingMode == "nxdomain" {
 			// means that we should return NXDOMAIN for any blocked request
 
 			return s.genNXDomain(m)
-
 		} else if s.conf.BlockingMode == "refused" {
 			// means that we should return NXDOMAIN for any blocked request
 
@@ -148,7 +145,6 @@ func (s *Server) makeResponseNullIP(req *dns.Msg) *dns.Msg {
 }
 
 func (s *Server) genBlockedHost(request *dns.Msg, newAddr string, d *proxy.DNSContext) *dns.Msg {
-
 	ip := net.ParseIP(newAddr)
 	if ip != nil {
 		return s.genResponseWithIP(request, ip)
@@ -168,7 +164,7 @@ func (s *Server) genBlockedHost(request *dns.Msg, newAddr string, d *proxy.DNSCo
 
 	err := s.dnsProxy.Resolve(newContext)
 	if err != nil {
-		log.Printf("Couldn't look up replacement host '%s': %s", newAddr, err)
+		log.Printf("Couldn't look up replacement host %q: %s", newAddr, err)
 		return s.genServerFailure(request)
 	}
 

internal/dnsforward/stats.go

@@ -5,12 +5,11 @@ import (
 	"strings"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/querylog"
-	"github.com/miekg/dns"
-
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
-	"github.com/AdguardTeam/AdGuardHome/stats"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/querylog"
+	"github.com/AdguardTeam/AdGuardHome/internal/stats"
 	"github.com/AdguardTeam/dnsproxy/proxy"
+	"github.com/miekg/dns"
 )
 
 // Write Stats data and logs
@@ -40,10 +39,16 @@ func processQueryLogsAndStats(ctx *dnsContext) int {
 			ClientIP:   getIP(d.Addr),
 		}
 
-		if d.Proto == "https" {
-			p.ClientProto = "doh"
-		} else if d.Proto == "tls" {
-			p.ClientProto = "dot"
+		switch d.Proto {
+		case proxy.ProtoHTTPS:
+			p.ClientProto = querylog.ClientProtoDOH
+		case proxy.ProtoQUIC:
+			p.ClientProto = querylog.ClientProtoDOQ
+		case proxy.ProtoTLS:
+			p.ClientProto = querylog.ClientProtoDOT
+		default:
+			// Consider this a plain DNS-over-UDP or DNS-over-TCL
+			// request.
 		}
 
 		if d.Upstream != nil {

internal/dnsforward/util.go

@@ -27,7 +27,7 @@ func stringArrayDup(a []string) []string {
 
 // Get IP address from net.Addr object
 // Note: we can't use net.SplitHostPort(a.String()) because of IPv6 zone:
-// https://github.com/AdguardTeam/AdGuardHome/issues/1261
+// https://github.com/AdguardTeam/AdGuardHome/internal/issues/1261
 func ipFromAddr(a net.Addr) string {
 	switch addr := a.(type) {
 	case *net.UDPAddr:

internal/home/auth.go

@@ -17,22 +17,22 @@ import (
 	"golang.org/x/crypto/bcrypt"
 )
 
-const cookieTTL = 365 * 24 // in hours
-const sessionCookieName = "agh_session"
+const (
+	cookieTTL         = 365 * 24 // in hours
+	sessionCookieName = "agh_session"
+)
 
 type session struct {
 	userName string
 	expire   uint32 // expiration time (in seconds)
 }
 
-/*
-expire byte[4]
-name_len byte[2]
-name byte[]
-*/
 func (s *session) serialize() []byte {
-	var data []byte
-	data = make([]byte, 4+2+len(s.userName))
+	const (
+		expireLen = 4
+		nameLen   = 2
+	)
+	data := make([]byte, expireLen+nameLen+len(s.userName))
 	binary.BigEndian.PutUint32(data[0:4], s.expire)
 	binary.BigEndian.PutUint16(data[4:6], uint16(len(s.userName)))
 	copy(data[6:], []byte(s.userName))
@@ -78,11 +78,11 @@ func InitAuth(dbFilename string, users []User, sessionTTL uint32) *Auth {
 	a.sessions = make(map[string]*session)
 	rand.Seed(time.Now().UTC().Unix())
 	var err error
-	a.db, err = bbolt.Open(dbFilename, 0644, nil)
+	a.db, err = bbolt.Open(dbFilename, 0o644, nil)
 	if err != nil {
 		log.Error("Auth: open DB: %s: %s", dbFilename, err)
 		if err.Error() == "invalid argument" {
-			log.Error("AdGuard Home cannot be initialized due to an incompatible file system.\nPlease read the explanation here: https://github.com/AdguardTeam/AdGuardHome/wiki/Getting-Started#limitations")
+			log.Error("AdGuard Home cannot be initialized due to an incompatible file system.\nPlease read the explanation here: https://github.com/AdguardTeam/AdGuardHome/internal/wiki/Getting-Started#limitations")
 		}
 		return nil
 	}
@@ -318,7 +318,7 @@ func handleLogin(w http.ResponseWriter, r *http.Request) {
 
 	cookie := Context.auth.httpCookie(req)
 	if len(cookie) == 0 {
-		log.Info("Auth: invalid user name or password: name='%s'", req.Name)
+		log.Info("Auth: invalid user name or password: name=%q", req.Name)
 		time.Sleep(1 * time.Second)
 		http.Error(w, "invalid user name or password", http.StatusBadRequest)
 		return
@@ -372,7 +372,6 @@ func parseCookie(cookie string) string {
 // nolint(gocyclo)
 func optionalAuth(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
-
 		if r.URL.Path == "/login.html" {
 			// redirect to dashboard if already authenticated
 			authRequired := Context.auth != nil && Context.auth.AuthRequired()
@@ -424,7 +423,6 @@ func optionalAuth(handler func(http.ResponseWriter, *http.Request)) func(http.Re
 				if r.URL.Path == "/" || r.URL.Path == "/index.html" {
 					if glProcessRedirect(w, r) {
 						log.Debug("Auth: redirected to login page by GL-Inet submodule")
-
 					} else {
 						w.Header().Set("Location", "/login.html")
 						w.WriteHeader(http.StatusFound)
@@ -474,7 +472,7 @@ func (a *Auth) UserAdd(u *User, password string) {
 }
 
 // UserFind - find a user
-func (a *Auth) UserFind(login string, password string) User {
+func (a *Auth) UserFind(login, password string) User {
 	a.lock.Lock()
 	defer a.lock.Unlock()
 	for _, u := range a.users {

internal/home/clients.go

@@ -13,10 +13,10 @@ import (
 
 	"github.com/AdguardTeam/dnsproxy/proxy"
 
-	"github.com/AdguardTeam/AdGuardHome/dhcpd"
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
-	"github.com/AdguardTeam/AdGuardHome/dnsforward"
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/utils"
 )
@@ -126,7 +126,6 @@ func (clients *clientsContainer) Start() {
 		}
 		go clients.periodicUpdate()
 	}
-
 }
 
 // Reload - reload auto-clients
@@ -173,7 +172,7 @@ func (clients *clientsContainer) addFromConfig(objects []clientObject) {
 
 		for _, s := range cy.BlockedServices {
 			if !dnsfilter.BlockedSvcKnown(s) {
-				log.Debug("Clients: skipping unknown blocked-service '%s'", s)
+				log.Debug("Clients: skipping unknown blocked-service %q", s)
 				continue
 			}
 			cli.BlockedServices = append(cli.BlockedServices, s)
@@ -181,7 +180,7 @@ func (clients *clientsContainer) addFromConfig(objects []clientObject) {
 
 		for _, t := range cy.Tags {
 			if !clients.tagKnown(t) {
-				log.Debug("Clients: skipping unknown tag '%s'", t)
+				log.Debug("Clients: skipping unknown tag %q", t)
 				continue
 			}
 			cli.Tags = append(cli.Tags, t)
@@ -377,7 +376,7 @@ func (clients *clientsContainer) check(c *Client) error {
 	}
 
 	if len(c.IDs) == 0 {
-		return fmt.Errorf("ID required")
+		return fmt.Errorf("id required")
 	}
 
 	for i, id := range c.IDs {
@@ -409,7 +408,7 @@ func (clients *clientsContainer) check(c *Client) error {
 
 	err := dnsforward.ValidateUpstreams(c.Upstreams)
 	if err != nil {
-		return fmt.Errorf("invalid upstream servers: %s", err)
+		return fmt.Errorf("invalid upstream servers: %w", err)
 	}
 
 	return nil
@@ -448,7 +447,7 @@ func (clients *clientsContainer) Add(c Client) (bool, error) {
 		clients.idIndex[id] = &c
 	}
 
-	log.Debug("Clients: added '%s': ID:%v [%d]", c.Name, c.IDs, len(clients.list))
+	log.Debug("Clients: added %q: ID:%v [%d]", c.Name, c.IDs, len(clients.list))
 	return true, nil
 }
 
@@ -590,7 +589,7 @@ func (clients *clientsContainer) addHost(ip, host string, source clientSource) (
 		}
 		clients.ipHost[ip] = ch
 	}
-	log.Debug("Clients: added '%s' -> '%s' [%d]", ip, host, len(clients.ipHost))
+	log.Debug("Clients: added %q -> %q [%d]", ip, host, len(clients.ipHost))
 	return true, nil
 }
 
@@ -607,22 +606,25 @@ func (clients *clientsContainer) rmHosts(source clientSource) int {
 	return n
 }
 
-// Fill clients array from system hosts-file
+// addFromHostsFile fills the clients hosts list from the system's hosts files.
 func (clients *clientsContainer) addFromHostsFile() {
 	hosts := clients.autoHosts.List()
 
 	clients.lock.Lock()
 	defer clients.lock.Unlock()
+
 	_ = clients.rmHosts(ClientSourceHostsFile)
 
 	n := 0
-	for ip, name := range hosts {
-		ok, err := clients.addHost(ip, name, ClientSourceHostsFile)
-		if err != nil {
-			log.Debug("Clients: %s", err)
-		}
-		if ok {
-			n++
+	for ip, names := range hosts {
+		for _, name := range names {
+			ok, err := clients.addHost(ip, name, ClientSourceHostsFile)
+			if err != nil {
+				log.Debug("Clients: %s", err)
+			}
+			if ok {
+				n++
+			}
 		}
 	}
 

internal/home/clients_test.go

@@ -6,7 +6,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/dhcpd"
+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
 
 	"github.com/stretchr/testify/assert"
 )

internal/home/config.go

@@ -6,11 +6,11 @@ import (
 	"path/filepath"
 	"sync"
 
-	"github.com/AdguardTeam/AdGuardHome/dhcpd"
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
-	"github.com/AdguardTeam/AdGuardHome/dnsforward"
-	"github.com/AdguardTeam/AdGuardHome/querylog"
-	"github.com/AdguardTeam/AdGuardHome/stats"
+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
+	"github.com/AdguardTeam/AdGuardHome/internal/querylog"
+	"github.com/AdguardTeam/AdGuardHome/internal/stats"
 	"github.com/AdguardTeam/golibs/file"
 	"github.com/AdguardTeam/golibs/log"
 	yaml "gopkg.in/yaml.v2"
@@ -120,6 +120,12 @@ var config = configuration{
 			Ratelimit:          20,
 			RefuseAny:          true,
 			AllServers:         false,
+
+			// set default maximum concurrent queries to 300
+			// we introduced a default limit due to this:
+			// https://github.com/AdguardTeam/AdGuardHome/issues/2015#issuecomment-674041912
+			// was later increased to 300 due to https://github.com/AdguardTeam/AdGuardHome/issues/2257
+			MaxGoroutines: 300,
 		},
 		FilteringEnabled:           true, // whether or not use filter lists
 		FiltersUpdateIntervalHours: 24,

internal/home/control.go

@@ -9,7 +9,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsforward"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/NYTimes/gziphandler"
 )

internal/home/control_filtering.go

@@ -12,7 +12,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/miekg/dns"
 )
@@ -26,10 +26,10 @@ func isValidURL(rawurl string) bool {
 
 	url, err := url.ParseRequestURI(rawurl)
 	if err != nil {
-		return false //Couldn't even parse the rawurl
+		return false // Couldn't even parse the rawurl
 	}
 	if len(url.Scheme) == 0 {
-		return false //No Scheme found
+		return false // No Scheme found
 	}
 	return true
 }
@@ -95,44 +95,57 @@ func (f *Filtering) handleFilteringAddURL(w http.ResponseWriter, r *http.Request
 }
 
 func (f *Filtering) handleFilteringRemoveURL(w http.ResponseWriter, r *http.Request) {
-
 	type request struct {
 		URL       string `json:"url"`
 		Whitelist bool   `json:"whitelist"`
 	}
+
 	req := request{}
 	err := json.NewDecoder(r.Body).Decode(&req)
 	if err != nil {
-		httpError(w, http.StatusBadRequest, "Failed to parse request body json: %s", err)
+		httpError(w, http.StatusBadRequest, "failed to parse request body json: %s", err)
 		return
 	}
 
-	// go through each element and delete if url matches
 	config.Lock()
-	newFilters := []filter{}
 	filters := &config.Filters
 	if req.Whitelist {
 		filters = &config.WhitelistFilters
 	}
-	for _, filter := range *filters {
-		if filter.URL != req.URL {
-			newFilters = append(newFilters, filter)
-		} else {
-			err := os.Rename(filter.Path(), filter.Path()+".old")
-			if err != nil {
-				log.Error("os.Rename: %s: %s", filter.Path(), err)
-			}
+
+	var deleted filter
+	var newFilters []filter
+	for _, f := range *filters {
+		if f.URL != req.URL {
+			newFilters = append(newFilters, f)
+
+			continue
+		}
+
+		deleted = f
+		path := f.Path()
+		err = os.Rename(path, path+".old")
+		if err != nil {
+			log.Error("deleting filter %q: %s", path, err)
 		}
 	}
-	// Update the configuration after removing filter files
+
 	*filters = newFilters
 	config.Unlock()
 
 	onConfigModified()
 	enableFilters(true)
 
-	// Note: the old files "filter.txt.old" aren't deleted - it's not really necessary,
-	//  but will require the additional code to run after enableFilters() is finished: i.e. complicated
+	// NOTE: The old files "filter.txt.old" aren't deleted.  It's not really
+	// necessary, but will require the additional complicated code to run
+	// after enableFilters is done.
+	//
+	// TODO(a.garipov): Make sure the above comment is true.
+
+	_, err = fmt.Fprintf(w, "OK %d rules\n", deleted.RulesCount)
+	if err != nil {
+		httpError(w, http.StatusInternalServerError, "couldn't write body: %s", err)
+	}
 }
 
 type filterURLJSON struct {

internal/home/control_install.go

@@ -13,9 +13,9 @@ import (
 	"runtime"
 	"strconv"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 
-	"github.com/AdguardTeam/AdGuardHome/dhcpd"
+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
 
 	"github.com/AdguardTeam/golibs/log"
 )
@@ -71,6 +71,7 @@ type checkConfigReqEnt struct {
 	IP      string `json:"ip"`
 	Autofix bool   `json:"autofix"`
 }
+
 type checkConfigReq struct {
 	Web         checkConfigReqEnt `json:"web"`
 	DNS         checkConfigReqEnt `json:"dns"`
@@ -81,11 +82,13 @@ type checkConfigRespEnt struct {
 	Status     string `json:"status"`
 	CanAutofix bool   `json:"can_autofix"`
 }
+
 type staticIPJSON struct {
 	Static string `json:"static"`
 	IP     string `json:"ip"`
 	Error  string `json:"error"`
 }
+
 type checkConfigResp struct {
 	Web      checkConfigRespEnt `json:"web"`
 	DNS      checkConfigRespEnt `json:"dns"`
@@ -214,31 +217,33 @@ func checkDNSStubListener() bool {
 	return true
 }
 
-const resolvedConfPath = "/etc/systemd/resolved.conf.d/adguardhome.conf"
-const resolvedConfData = `[Resolve]
+const (
+	resolvedConfPath = "/etc/systemd/resolved.conf.d/adguardhome.conf"
+	resolvedConfData = `[Resolve]
 DNS=127.0.0.1
 DNSStubListener=no
 `
+)
 const resolvConfPath = "/etc/resolv.conf"
 
 // Deactivate DNSStubListener
 func disableDNSStubListener() error {
 	dir := filepath.Dir(resolvedConfPath)
-	err := os.MkdirAll(dir, 0755)
+	err := os.MkdirAll(dir, 0o755)
 	if err != nil {
-		return fmt.Errorf("os.MkdirAll: %s: %s", dir, err)
+		return fmt.Errorf("os.MkdirAll: %s: %w", dir, err)
 	}
 
-	err = ioutil.WriteFile(resolvedConfPath, []byte(resolvedConfData), 0644)
+	err = ioutil.WriteFile(resolvedConfPath, []byte(resolvedConfData), 0o644)
 	if err != nil {
-		return fmt.Errorf("ioutil.WriteFile: %s: %s", resolvedConfPath, err)
+		return fmt.Errorf("ioutil.WriteFile: %s: %w", resolvedConfPath, err)
 	}
 
 	_ = os.Rename(resolvConfPath, resolvConfPath+".backup")
 	err = os.Symlink("/run/systemd/resolve/resolv.conf", resolvConfPath)
 	if err != nil {
 		_ = os.Remove(resolvedConfPath) // remove the file we've just created
-		return fmt.Errorf("os.Symlink: %s: %s", resolvConfPath, err)
+		return fmt.Errorf("os.Symlink: %s: %w", resolvConfPath, err)
 	}
 
 	cmd := exec.Command("systemctl", "reload-or-restart", "systemd-resolved")
@@ -259,6 +264,7 @@ type applyConfigReqEnt struct {
 	IP   string `json:"ip"`
 	Port int    `json:"port"`
 }
+
 type applyConfigReq struct {
 	Web      applyConfigReqEnt `json:"web"`
 	DNS      applyConfigReqEnt `json:"dns"`

internal/home/control_update.go

@@ -10,8 +10,8 @@ import (
 	"strings"
 	"syscall"
 
-	"github.com/AdguardTeam/AdGuardHome/update"
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/update"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/golibs/log"
 )
 
@@ -46,7 +46,7 @@ func handleGetVersionJSON(w http.ResponseWriter, r *http.Request) {
 		Context.controlLock.Unlock()
 		if err != nil && strings.HasSuffix(err.Error(), "i/o timeout") {
 			// This case may happen while we're restarting DNS server
-			// https://github.com/AdguardTeam/AdGuardHome/issues/934
+			// https://github.com/AdguardTeam/AdGuardHome/internal/issues/934
 			continue
 		}
 		break

internal/home/control_update_test.go

@@ -53,10 +53,10 @@ func TestDoUpdate(t *testing.T) {
 		updateDir:        Context.workDir + "/agh-update-" + newver,
 		backupDir:        Context.workDir + "/agh-backup",
 		configName:       Context.workDir + "/AdGuardHome.yaml",
-		updateConfigName: Context.workDir + "/agh-update-" + newver + "/AdGuardHome/AdGuardHome.yaml",
+		updateConfigName: Context.workDir + "/agh-update-" + newver + "/AdGuardHome/internal/AdGuardHome.yaml",
 		curBinName:       Context.workDir + "/AdGuardHome",
 		bkpBinName:       Context.workDir + "/agh-backup/AdGuardHome",
-		newBinName:       Context.workDir + "/agh-update-" + newver + "/AdGuardHome/AdGuardHome",
+		newBinName:       Context.workDir + "/agh-update-" + newver + "/AdGuardHome/internal/AdGuardHome",
 	}
 
 	assert.Equal(t, uu.pkgURL, u.pkgURL)

internal/home/dns.go

@@ -5,14 +5,13 @@ import (
 	"net"
 	"path/filepath"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
-	"github.com/AdguardTeam/AdGuardHome/dnsforward"
-	"github.com/AdguardTeam/AdGuardHome/querylog"
-	"github.com/AdguardTeam/AdGuardHome/stats"
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
+	"github.com/AdguardTeam/AdGuardHome/internal/querylog"
+	"github.com/AdguardTeam/AdGuardHome/internal/stats"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
 )
 
 // Called by other modules when configuration is changed
@@ -75,7 +74,7 @@ func initDNSServer() error {
 	err = Context.dnsServer.Prepare(&dnsConfig)
 	if err != nil {
 		closeDNSServer()
-		return fmt.Errorf("dnsServer.Prepare: %s", err)
+		return fmt.Errorf("dnsServer.Prepare: %w", err)
 	}
 
 	Context.rdns = InitRDNS(Context.dnsServer, &Context.clients)
@@ -96,41 +95,41 @@ func isPublicIP(ip net.IP) bool {
 	if ip4 != nil {
 		switch ip4[0] {
 		case 0:
-			return false //software
+			return false // software
 		case 10:
-			return false //private network
+			return false // private network
 		case 127:
-			return false //loopback
+			return false // loopback
 		case 169:
 			if ip4[1] == 254 {
-				return false //link-local
+				return false // link-local
 			}
 		case 172:
 			if ip4[1] >= 16 && ip4[1] <= 31 {
-				return false //private network
+				return false // private network
 			}
 		case 192:
-			if (ip4[1] == 0 && ip4[2] == 0) || //private network
-				(ip4[1] == 0 && ip4[2] == 2) || //documentation
-				(ip4[1] == 88 && ip4[2] == 99) || //reserved
-				(ip4[1] == 168) { //private network
+			if (ip4[1] == 0 && ip4[2] == 0) || // private network
+				(ip4[1] == 0 && ip4[2] == 2) || // documentation
+				(ip4[1] == 88 && ip4[2] == 99) || // reserved
+				(ip4[1] == 168) { // private network
 				return false
 			}
 		case 198:
-			if (ip4[1] == 18 || ip4[2] == 19) || //private network
-				(ip4[1] == 51 || ip4[2] == 100) { //documentation
+			if (ip4[1] == 18 || ip4[2] == 19) || // private network
+				(ip4[1] == 51 || ip4[2] == 100) { // documentation
 				return false
 			}
 		case 203:
-			if ip4[1] == 0 && ip4[2] == 113 { //documentation
+			if ip4[1] == 0 && ip4[2] == 113 { // documentation
 				return false
 			}
 		case 224:
-			if ip4[1] == 0 && ip4[2] == 0 { //multicast
+			if ip4[1] == 0 && ip4[2] == 0 { // multicast
 				return false
 			}
 		case 255:
-			if ip4[1] == 255 && ip4[2] == 255 && ip4[3] == 255 { //subnet
+			if ip4[1] == 255 && ip4[2] == 255 && ip4[3] == 255 { // subnet
 				return false
 			}
 		}
@@ -313,7 +312,7 @@ func startDNSServer() error {
 
 	err := Context.dnsServer.Start()
 	if err != nil {
-		return errorx.Decorate(err, "Couldn't start forwarding DNS server")
+		return fmt.Errorf("couldn't start forwarding DNS server: %w", err)
 	}
 
 	Context.dnsFilter.Start()
@@ -340,7 +339,7 @@ func reconfigureDNSServer() error {
 	newconfig := generateServerConfig()
 	err := Context.dnsServer.Reconfigure(&newconfig)
 	if err != nil {
-		return errorx.Decorate(err, "Couldn't start forwarding DNS server")
+		return fmt.Errorf("couldn't start forwarding DNS server: %w", err)
 	}
 
 	return nil
@@ -353,7 +352,7 @@ func stopDNSServer() error {
 
 	err := Context.dnsServer.Stop()
 	if err != nil {
-		return errorx.Decorate(err, "Couldn't stop forwarding DNS server")
+		return fmt.Errorf("couldn't stop forwarding DNS server: %w", err)
 	}
 
 	closeDNSServer()

internal/home/filter.go

@@ -15,14 +15,11 @@ import (
 	"sync/atomic"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
 	"github.com/AdguardTeam/golibs/log"
 )
 
-var (
-	nextFilterID = time.Now().Unix() // semi-stable way to generate an unique ID
-)
+var nextFilterID = time.Now().Unix() // semi-stable way to generate an unique ID
 
 // Filtering - module object
 type Filtering struct {
@@ -35,7 +32,7 @@ type Filtering struct {
 // Init - initialize the module
 func (f *Filtering) Init() {
 	f.filterTitleRegexp = regexp.MustCompile(`^! Title: +(.*)$`)
-	_ = os.MkdirAll(filepath.Join(Context.getDataDir(), filterDir), 0755)
+	_ = os.MkdirAll(filepath.Join(Context.getDataDir(), filterDir), 0o755)
 	f.loadFilters(config.Filters)
 	f.loadFilters(config.WhitelistFilters)
 	deduplicateFilters()
@@ -466,7 +463,6 @@ func (f *Filtering) parseFilterContents(file io.Reader) (int, uint32, string) {
 		line = strings.TrimSpace(line)
 		if len(line) == 0 {
 			//
-
 		} else if line[0] == '!' {
 			m := f.filterTitleRegexp.FindAllStringSubmatch(line, -1)
 			if len(m) > 0 && len(m[0]) >= 2 && !seenTitle {
@@ -476,7 +472,6 @@ func (f *Filtering) parseFilterContents(file io.Reader) (int, uint32, string) {
 
 		} else if line[0] == '#' {
 			//
-
 		} else {
 			rulesCount++
 		}
@@ -521,7 +516,7 @@ func (f *Filtering) updateIntl(filter *filter) (bool, error) {
 	if filepath.IsAbs(filter.URL) {
 		f, err := os.Open(filter.URL)
 		if err != nil {
-			return false, fmt.Errorf("open file: %s", err)
+			return false, fmt.Errorf("open file: %w", err)
 		}
 		defer f.Close()
 		reader = f
@@ -552,8 +547,10 @@ func (f *Filtering) updateIntl(filter *filter) (bool, error) {
 		total += n
 
 		if htmlTest {
-			// gather full buffer firstChunk and perform its data tests
-			num := util.MinInt(n, len(firstChunk)-firstChunkLen)
+			num := len(firstChunk) - firstChunkLen
+			if n < num {
+				num = n
+			}
 			copied := copy(firstChunk[firstChunkLen:], buf[:num])
 			firstChunkLen += copied
 
@@ -563,8 +560,7 @@ func (f *Filtering) updateIntl(filter *filter) (bool, error) {
 				}
 
 				s := strings.ToLower(string(firstChunk))
-				if strings.Index(s, "<html") >= 0 ||
-					strings.Index(s, "<!doctype") >= 0 {
+				if strings.Contains(s, "<html") || strings.Contains(s, "<!doctype") {
 					return false, fmt.Errorf("data is HTML, not plain text")
 				}
 

internal/home/home.go

@@ -1,3 +1,4 @@
+// Package home contains AdGuard Home's HTTP API methods.
 package home
 
 import (
@@ -8,6 +9,7 @@ import (
 	"io/ioutil"
 	"net"
 	"net/http"
+	"net/http/pprof"
 	"net/url"
 	"os"
 	"os/signal"
@@ -20,18 +22,15 @@ import (
 
 	"gopkg.in/natefinch/lumberjack.v2"
 
-	"github.com/AdguardTeam/AdGuardHome/update"
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/agherr"
+	"github.com/AdguardTeam/AdGuardHome/internal/update"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 
-	"github.com/joomcode/errorx"
-
-	"github.com/AdguardTeam/AdGuardHome/isdelve"
-
-	"github.com/AdguardTeam/AdGuardHome/dhcpd"
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
-	"github.com/AdguardTeam/AdGuardHome/dnsforward"
-	"github.com/AdguardTeam/AdGuardHome/querylog"
-	"github.com/AdguardTeam/AdGuardHome/stats"
+	"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
+	"github.com/AdguardTeam/AdGuardHome/internal/querylog"
+	"github.com/AdguardTeam/AdGuardHome/internal/stats"
 	"github.com/AdguardTeam/golibs/log"
 )
 
@@ -95,7 +94,7 @@ func (c *homeContext) getDataDir() string {
 var Context homeContext
 
 // Main is the entry point
-func Main(version string, channel string, armVer string) {
+func Main(version, channel, armVer string) {
 	// Init update-related global variables
 	versionString = version
 	updateChannel = channel
@@ -111,7 +110,7 @@ func Main(version string, channel string, armVer string) {
 	go func() {
 		for {
 			sig := <-Context.appSignalChannel
-			log.Info("Received signal '%s'", sig)
+			log.Info("Received signal %q", sig)
 			switch sig {
 			case syscall.SIGHUP:
 				Context.clients.Reload()
@@ -264,7 +263,11 @@ func run(args options) {
 
 		if config.DebugPProf {
 			mux := http.NewServeMux()
-			util.PProfRegisterWebHandlers(mux)
+			mux.HandleFunc("/debug/pprof/", pprof.Index)
+			mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
+			mux.HandleFunc("/debug/pprof/profile", pprof.Profile)
+			mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol)
+			mux.HandleFunc("/debug/pprof/trace", pprof.Trace)
 			go func() {
 				log.Info("pprof: listening on localhost:6060")
 				err := http.ListenAndServe("localhost:6060", mux)
@@ -273,7 +276,7 @@ func run(args options) {
 		}
 	}
 
-	err := os.MkdirAll(Context.getDataDir(), 0755)
+	err := os.MkdirAll(Context.getDataDir(), 0o755)
 	if err != nil {
 		log.Fatalf("Cannot create DNS data dir at %s: %s", Context.getDataDir(), err)
 	}
@@ -352,10 +355,7 @@ func checkPermissions() {
 		// On Windows we need to have admin rights to run properly
 
 		admin, _ := util.HaveAdminRights()
-		if //noinspection ALL
-		admin || isdelve.Enabled {
-			// Don't forget that for this to work you need to add "delve" tag explicitly
-			// https://stackoverflow.com/questions/47879070/how-can-i-see-if-the-goland-debugger-is-running-in-the-program
+		if admin {
 			return
 		}
 
@@ -381,7 +381,7 @@ Please note, that this is crucial for a server to be able to use privileged port
 You have two options:
 1. Run AdGuard Home with root privileges
 2. On Linux you can grant the CAP_NET_BIND_SERVICE capability:
-https://github.com/AdguardTeam/AdGuardHome/wiki/Getting-Started#running-without-superuser`
+https://github.com/AdguardTeam/AdGuardHome/internal/wiki/Getting-Started#running-without-superuser`
 
 				log.Fatal(msg)
 			}
@@ -398,7 +398,7 @@ Please note, that this is crucial for a DNS server to be able to use that port.`
 // Write PID to a file
 func writePIDFile(fn string) bool {
 	data := fmt.Sprintf("%d", os.Getpid())
-	err := ioutil.WriteFile(fn, []byte(data), 0644)
+	err := ioutil.WriteFile(fn, []byte(data), 0o644)
 	if err != nil {
 		log.Error("Couldn't write PID to file %s: %v", fn, err)
 		return false
@@ -481,7 +481,7 @@ func configureLogger(args options) {
 			logFilePath = ls.LogFile
 		}
 
-		_, err := os.OpenFile(logFilePath, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
+		_, err := os.OpenFile(logFilePath, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0o644)
 		if err != nil {
 			log.Fatalf("cannot create a log file: %s", err)
 		}
@@ -492,7 +492,7 @@ func configureLogger(args options) {
 			LocalTime:  ls.LogLocalTime,
 			MaxBackups: ls.LogMaxBackups,
 			MaxSize:    ls.LogMaxSize, // megabytes
-			MaxAge:     ls.LogMaxAge,  //days
+			MaxAge:     ls.LogMaxAge,  // days
 		})
 	}
 }
@@ -611,11 +611,7 @@ func detectFirstRun() bool {
 		configfile = filepath.Join(Context.workDir, Context.configFilename)
 	}
 	_, err := os.Stat(configfile)
-	if !os.IsNotExist(err) {
-		// do nothing, file exists
-		return false
-	}
-	return true
+	return os.IsNotExist(err)
 }
 
 // Connect to a remote server resolving hostname using our own DNS server
@@ -656,7 +652,7 @@ func customDialContext(ctx context.Context, network, addr string) (net.Conn, err
 		}
 		return con, err
 	}
-	return nil, errorx.DecorateMany(fmt.Sprintf("couldn't dial to %s", addr), dialErrs...)
+	return nil, agherr.Many(fmt.Sprintf("couldn't dial to %s", addr), dialErrs...)
 }
 
 func getHTTPProxy(req *http.Request) (*url.URL, error) {

internal/home/i18n.go

@@ -58,9 +58,9 @@ func handleI18nCurrentLanguage(w http.ResponseWriter, r *http.Request) {
 	log.Printf("config.Language is %s", config.Language)
 	_, err := fmt.Fprintf(w, "%s\n", config.Language)
 	if err != nil {
-		errorText := fmt.Sprintf("Unable to write response json: %s", err)
-		log.Println(errorText)
-		http.Error(w, errorText, http.StatusInternalServerError)
+		msg := fmt.Sprintf("Unable to write response json: %s", err)
+		log.Println(msg)
+		http.Error(w, msg, http.StatusInternalServerError)
 		return
 	}
 }
@@ -68,23 +68,23 @@ func handleI18nCurrentLanguage(w http.ResponseWriter, r *http.Request) {
 func handleI18nChangeLanguage(w http.ResponseWriter, r *http.Request) {
 	body, err := ioutil.ReadAll(r.Body)
 	if err != nil {
-		errorText := fmt.Sprintf("failed to read request body: %s", err)
-		log.Println(errorText)
-		http.Error(w, errorText, http.StatusBadRequest)
+		msg := fmt.Sprintf("failed to read request body: %s", err)
+		log.Println(msg)
+		http.Error(w, msg, http.StatusBadRequest)
 		return
 	}
 
 	language := strings.TrimSpace(string(body))
 	if language == "" {
-		errorText := fmt.Sprintf("empty language specified")
-		log.Println(errorText)
-		http.Error(w, errorText, http.StatusBadRequest)
+		msg := "empty language specified"
+		log.Println(msg)
+		http.Error(w, msg, http.StatusBadRequest)
 		return
 	}
 	if !isLanguageAllowed(language) {
-		errorText := fmt.Sprintf("unknown language specified: %s", language)
-		log.Println(errorText)
-		http.Error(w, errorText, http.StatusBadRequest)
+		msg := fmt.Sprintf("unknown language specified: %s", language)
+		log.Println(msg)
+		http.Error(w, msg, http.StatusBadRequest)
 		return
 	}
 

internal/home/memory.go

@@ -11,7 +11,7 @@ import (
 // memoryUsage implements a couple of not really beautiful hacks which purpose is to
 // make OS reclaim the memory freed by AdGuard Home as soon as possible.
 // See this for the details on the performance hits & gains:
-// https://github.com/AdguardTeam/AdGuardHome/issues/2044#issuecomment-687042211
+// https://github.com/AdguardTeam/AdGuardHome/internal/issues/2044#issuecomment-687042211
 func memoryUsage(args options) {
 	if args.disableMemoryOptimization {
 		log.Info("Memory optimization is disabled")
@@ -32,13 +32,9 @@ func memoryUsage(args options) {
 	// that the OS could reclaim the free memory
 	go func() {
 		ticker := time.NewTicker(5 * time.Minute)
-		for {
-			select {
-			case t := <-ticker.C:
-				t.Second()
-				log.Debug("Free OS memory")
-				debug.FreeOSMemory()
-			}
+		for range ticker.C {
+			log.Debug("free os memory")
+			debug.FreeOSMemory()
 		}
 	}()
 }

internal/home/mobileconfig.go

@@ -2,6 +2,7 @@ package home
 
 import (
 	"fmt"
+	"net"
 	"net/http"
 
 	uuid "github.com/satori/go.uuid"
@@ -14,7 +15,7 @@ type DNSSettings struct {
 	ServerName  string `plist:",omitempty"`
 }
 
-type PayloadContent = struct {
+type PayloadContent struct {
 	Name               string
 	PayloadDescription string
 	PayloadDisplayName string
@@ -25,7 +26,7 @@ type PayloadContent = struct {
 	DNSSettings        DNSSettings
 }
 
-type MobileConfig = struct {
+type MobileConfig struct {
 	PayloadContent           []PayloadContent
 	PayloadDescription       string
 	PayloadDisplayName       string
@@ -40,8 +41,21 @@ func genUUIDv4() string {
 	return uuid.NewV4().String()
 }
 
-func getMobileConfig(r *http.Request, d DNSSettings) ([]byte, error) {
-	name := fmt.Sprintf("%s DNS over %s", r.Host, d.DNSProtocol)
+const (
+	dnsProtoHTTPS = "HTTPS"
+	dnsProtoTLS   = "TLS"
+)
+
+func getMobileConfig(d DNSSettings) ([]byte, error) {
+	var name string
+	switch d.DNSProtocol {
+	case dnsProtoHTTPS:
+		name = fmt.Sprintf("%s DoH", d.ServerName)
+	case dnsProtoTLS:
+		name = fmt.Sprintf("%s DoT", d.ServerName)
+	default:
+		return nil, fmt.Errorf("bad dns protocol %q", d.DNSProtocol)
+	}
 
 	data := MobileConfig{
 		PayloadContent: []PayloadContent{{
@@ -66,9 +80,8 @@ func getMobileConfig(r *http.Request, d DNSSettings) ([]byte, error) {
 	return plist.MarshalIndent(data, plist.XMLFormat, "\t")
 }
 
-func handleMobileConfig(w http.ResponseWriter, r *http.Request, d DNSSettings) {
-	mobileconfig, err := getMobileConfig(r, d)
-
+func handleMobileConfig(w http.ResponseWriter, d DNSSettings) {
+	mobileconfig, err := getMobileConfig(d)
 	if err != nil {
 		httpError(w, http.StatusInternalServerError, "plist.MarshalIndent: %s", err)
 	}
@@ -78,15 +91,23 @@ func handleMobileConfig(w http.ResponseWriter, r *http.Request, d DNSSettings) {
 }
 
 func handleMobileConfigDoh(w http.ResponseWriter, r *http.Request) {
-	handleMobileConfig(w, r, DNSSettings{
-		DNSProtocol: "HTTPS",
+	handleMobileConfig(w, DNSSettings{
+		DNSProtocol: dnsProtoHTTPS,
 		ServerURL:   fmt.Sprintf("https://%s/dns-query", r.Host),
 	})
 }
 
 func handleMobileConfigDot(w http.ResponseWriter, r *http.Request) {
-	handleMobileConfig(w, r, DNSSettings{
-		DNSProtocol: "TLS",
-		ServerName:  r.Host,
+	var err error
+
+	var host string
+	host, _, err = net.SplitHostPort(r.Host)
+	if err != nil {
+		httpError(w, http.StatusBadRequest, "getting host: %s", err)
+	}
+
+	handleMobileConfig(w, DNSSettings{
+		DNSProtocol: dnsProtoTLS,
+		ServerName:  host,
 	})
 }

internal/home/mobileconfig_test.go

@@ -0,0 +1,33 @@
+package home
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"howett.net/plist"
+)
+
+func TestHandleMobileConfigDot(t *testing.T) {
+	var err error
+
+	var r *http.Request
+	r, err = http.NewRequest(http.MethodGet, "https://example.com:12345/apple/dot.mobileconfig", nil)
+	assert.Nil(t, err)
+
+	w := httptest.NewRecorder()
+
+	handleMobileConfigDot(w, r)
+	assert.Equal(t, http.StatusOK, w.Code)
+
+	var mc MobileConfig
+	_, err = plist.Unmarshal(w.Body.Bytes(), &mc)
+	assert.Nil(t, err)
+
+	if assert.Equal(t, 1, len(mc.PayloadContent)) {
+		assert.Equal(t, "example.com DoT", mc.PayloadContent[0].Name)
+		assert.Equal(t, "example.com DoT", mc.PayloadContent[0].PayloadDisplayName)
+		assert.Equal(t, "example.com", mc.PayloadContent[0].DNSSettings.ServerName)
+	}
+}

internal/home/options.go

@@ -106,7 +106,7 @@ var portArg = arg{
 		var p int
 		minPort, maxPort := 0, 1<<16-1
 		if p, err = strconv.Atoi(v); err != nil {
-			err = fmt.Errorf("port '%s' is not a number", v)
+			err = fmt.Errorf("port %q is not a number", v)
 		} else if p < minPort || p > maxPort {
 			err = fmt.Errorf("port %d not in range %d - %d", p, minPort, maxPort)
 		} else {

internal/home/rdns.go

@@ -5,7 +5,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsforward"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
 	"github.com/AdguardTeam/golibs/cache"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/miekg/dns"
@@ -116,8 +116,7 @@ func (r *RDNS) resolve(ip string) string {
 // Add the hostname:IP pair to "Clients" array
 func (r *RDNS) workerLoop() {
 	for {
-		var ip string
-		ip = <-r.ipChannel
+		ip := <-r.ipChannel
 
 		host := r.resolve(ip)
 		if len(host) == 0 {

internal/home/rdns_test.go

@@ -3,7 +3,7 @@ package home
 import (
 	"testing"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsforward"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
 	"github.com/stretchr/testify/assert"
 )
 

internal/home/service.go

@@ -9,7 +9,7 @@ import (
 	"strings"
 	"syscall"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/kardianos/service"
 )
@@ -104,7 +104,7 @@ func sendSigReload() {
 		return
 	}
 
-	pid, err := strconv.Atoi(parts[0])
+	pid, err := strconv.Atoi(strings.TrimSpace(parts[0]))
 	if err != nil {
 		log.Error("Can't read PID file %s: %s", pidfile, err)
 		return
@@ -203,7 +203,7 @@ func handleServiceInstallCommand(s service.Service) {
 		log.Fatal(err)
 	}
 
-	if util.IsOpenWrt() {
+	if util.IsOpenWRT() {
 		// On OpenWrt it is important to run enable after the service installation
 		// Otherwise, the service won't start on the system startup
 		_, err := runInitdCommand("enable")
@@ -230,7 +230,7 @@ Click on the link below and follow the Installation Wizard steps to finish setup
 
 // handleServiceStatusCommand handles service "uninstall" command
 func handleServiceUninstallCommand(s service.Service) {
-	if util.IsOpenWrt() {
+	if util.IsOpenWRT() {
 		// On OpenWrt it is important to run disable command first
 		// as it will remove the symlink
 		_, err := runInitdCommand("disable")
@@ -272,14 +272,14 @@ func configureService(c *service.Config) {
 	// Redirect StdErr & StdOut to files.
 	c.Option["LogOutput"] = true
 
-	// Use modified service file templates
+	// Use modified service file templates.
 	c.Option["SystemdScript"] = systemdScript
 	c.Option["SysvScript"] = sysvScript
 
-	// On OpenWrt we're using a different type of sysvScript
-	if util.IsOpenWrt() {
+	// On OpenWrt we're using a different type of sysvScript.
+	if util.IsOpenWRT() {
 		c.Option["SysvScript"] = openWrtScript
-	} else if util.IsFreeBSD() {
+	} else if runtime.GOOS == "freebsd" {
 		c.Option["SysvScript"] = freeBSDScript
 	}
 }
@@ -452,7 +452,7 @@ exit 0
 `
 
 // OpenWrt procd init script
-// https://github.com/AdguardTeam/AdGuardHome/issues/1386
+// https://github.com/AdguardTeam/AdGuardHome/internal/issues/1386
 const openWrtScript = `#!/bin/sh /etc/rc.common
 
 USE_PROCD=1
@@ -502,6 +502,7 @@ status() {
     fi
 }
 `
+
 const freeBSDScript = `#!/bin/sh
 # PROVIDE: {{.Name}}
 # REQUIRE: networking

internal/home/tls.go

@@ -20,7 +20,6 @@ import (
 	"time"
 
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
 )
 
 var tlsWebHandlersRegistered = false
@@ -136,6 +135,10 @@ func (t *TLSMod) Reload() {
 	t.certLastMod = fi.ModTime().UTC()
 
 	_ = reconfigureDNSServer()
+
+	t.confLock.Lock()
+	tlsConf = t.conf
+	t.confLock.Unlock()
 	Context.web.TLSConfigChanged(tlsConf)
 }
 
@@ -302,12 +305,11 @@ func (t *TLSMod) handleTLSConfigure(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-func verifyCertChain(data *tlsConfigStatus, certChain string, serverName string) error {
+func verifyCertChain(data *tlsConfigStatus, certChain, serverName string) error {
 	log.Tracef("TLS: got certificate: %d bytes", len(certChain))
 
 	// now do a more extended validation
-	var certs []*pem.Block    // PEM-encoded certificates
-	var skippedBytes []string // skipped bytes
+	var certs []*pem.Block // PEM-encoded certificates
 
 	pemblock := []byte(certChain)
 	for {
@@ -318,10 +320,6 @@ func verifyCertChain(data *tlsConfigStatus, certChain string, serverName string)
 		}
 		if decoded.Type == "CERTIFICATE" {
 			certs = append(certs, decoded)
-		} else {
-			// ignore "this result of append is never used" warning
-			// nolint
-			skippedBytes = append(skippedBytes, decoded.Type)
 		}
 	}
 
@@ -337,7 +335,7 @@ func verifyCertChain(data *tlsConfigStatus, certChain string, serverName string)
 	}
 
 	if len(parsedCerts) == 0 {
-		data.WarningValidation = fmt.Sprintf("You have specified an empty certificate")
+		data.WarningValidation = "You have specified an empty certificate"
 		return errors.New(data.WarningValidation)
 	}
 
@@ -387,8 +385,7 @@ func verifyCertChain(data *tlsConfigStatus, certChain string, serverName string)
 
 func validatePkey(data *tlsConfigStatus, pkey string) error {
 	// now do a more extended validation
-	var key *pem.Block        // PEM-encoded certificates
-	var skippedBytes []string // skipped bytes
+	var key *pem.Block // PEM-encoded certificates
 
 	// go through all pem blocks, but take first valid pem block and drop the rest
 	pemblock := []byte(pkey)
@@ -401,10 +398,6 @@ func validatePkey(data *tlsConfigStatus, pkey string) error {
 		if decoded.Type == "PRIVATE KEY" || strings.HasSuffix(decoded.Type, " PRIVATE KEY") {
 			key = decoded
 			break
-		} else {
-			// ignore "this result of append is never used"
-			// nolint
-			skippedBytes = append(skippedBytes, decoded.Type)
 		}
 	}
 
@@ -490,13 +483,13 @@ func unmarshalTLS(r *http.Request) (tlsConfigSettings, error) {
 	data := tlsConfigSettings{}
 	err := json.NewDecoder(r.Body).Decode(&data)
 	if err != nil {
-		return data, errorx.Decorate(err, "Failed to parse new TLS config json")
+		return data, fmt.Errorf("failed to parse new TLS config json: %w", err)
 	}
 
 	if data.CertificateChain != "" {
 		certPEM, err := base64.StdEncoding.DecodeString(data.CertificateChain)
 		if err != nil {
-			return data, errorx.Decorate(err, "Failed to base64-decode certificate chain")
+			return data, fmt.Errorf("failed to base64-decode certificate chain: %w", err)
 		}
 		data.CertificateChain = string(certPEM)
 		if data.CertificatePath != "" {
@@ -507,7 +500,7 @@ func unmarshalTLS(r *http.Request) (tlsConfigSettings, error) {
 	if data.PrivateKey != "" {
 		keyPEM, err := base64.StdEncoding.DecodeString(data.PrivateKey)
 		if err != nil {
-			return data, errorx.Decorate(err, "Failed to base64-decode private key")
+			return data, fmt.Errorf("failed to base64-decode private key: %w", err)
 		}
 
 		data.PrivateKey = string(keyPEM)

internal/home/upgrade.go

@@ -5,7 +5,7 @@ import (
 	"os"
 	"path/filepath"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 
 	"github.com/AdguardTeam/golibs/file"
 	"github.com/AdguardTeam/golibs/log"
@@ -184,7 +184,7 @@ func upgradeSchema2to3(diskConfig *map[string]interface{}) error {
 			newDNSConfig[fmt.Sprint(k)] = v
 		}
 	default:
-		return fmt.Errorf("DNS configuration is not a map")
+		return fmt.Errorf("dns configuration is not a map")
 	}
 
 	// Replace bootstrap_dns value filed with new array contains old bootstrap_dns inside
@@ -217,7 +217,6 @@ func upgradeSchema3to4(diskConfig *map[string]interface{}) error {
 	case []interface{}:
 
 		for i := range arr {
-
 			switch c := arr[i].(type) {
 
 			case map[interface{}]interface{}:
@@ -309,7 +308,6 @@ func upgradeSchema5to6(diskConfig *map[string]interface{}) error {
 	case []interface{}:
 
 		for i := range arr {
-
 			switch c := arr[i].(type) {
 
 			case map[interface{}]interface{}:

internal/home/web.go

@@ -9,7 +9,7 @@ import (
 	"strconv"
 	"sync"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/NYTimes/gziphandler"
 	"github.com/gobuffalo/packr"
@@ -63,7 +63,7 @@ func CreateWeb(conf *WebConfig) *Web {
 	w.errLogger = golog.New(&lw, "", 0)
 
 	// Initialize and run the admin Web interface
-	box := packr.NewBox("../build/static")
+	box := packr.NewBox("../../build/static")
 
 	// if not configured, redirect / to /install.html, otherwise redirect /install.html to /
 	http.Handle("/", postInstallHandler(optionalAuthHandler(gziphandler.GzipHandler(http.FileServer(box)))))

internal/home/whois.go

@@ -9,7 +9,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/util"
+	"github.com/AdguardTeam/AdGuardHome/internal/util"
 
 	"github.com/AdguardTeam/golibs/cache"
 	"github.com/AdguardTeam/golibs/log"
@@ -116,7 +116,7 @@ func whoisParse(data string) map[string]string {
 }
 
 // Send request to a server and receive the response
-func (w *Whois) query(target string, serverAddr string) (string, error) {
+func (w *Whois) query(target, serverAddr string) (string, error) {
 	addr, _, _ := net.SplitHostPort(serverAddr)
 	if addr == "whois.arin.net" {
 		target = "n + " + target
@@ -168,7 +168,7 @@ func (w *Whois) queryAll(target string) (string, error) {
 
 		log.Debug("Whois: redirected to %s  IP:%s", redir, target)
 	}
-	return "", fmt.Errorf("Whois: redirect loop")
+	return "", fmt.Errorf("whois: redirect loop")
 }
 
 // Request WHOIS information
@@ -224,8 +224,7 @@ func (w *Whois) Begin(ip string) {
 // Get IP address from channel; get WHOIS info; associate info with a client
 func (w *Whois) workerLoop() {
 	for {
-		var ip string
-		ip = <-w.ipChan
+		ip := <-w.ipChan
 
 		info := w.process(ip)
 		if len(info) == 0 {

internal/home/whois_test.go

@@ -3,7 +3,7 @@ package home
 import (
 	"testing"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsforward"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
 	"github.com/stretchr/testify/assert"
 )
 

internal/querylog/decode.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/miekg/dns"
 )
@@ -38,7 +38,7 @@ func decodeLogEntry(ent *logEntry, str string) {
 			ent.QClass = v
 
 		case "CP":
-			ent.ClientProto = v
+			ent.ClientProto, err = NewClientProto(v)
 
 		case "Answer":
 			ent.Answer, err = base64.StdEncoding.DecodeString(v)

internal/querylog/decode_test.go

@@ -15,7 +15,7 @@ func TestJSON(t *testing.T) {
 	assert.Equal(t, "keystr", k)
 	assert.Equal(t, "val", v)
 
-	k, v, jtype = readJSON(&s)
+	k, _, jtype = readJSON(&s)
 	assert.Equal(t, jtype, int32(jsonTObj))
 	assert.Equal(t, "obj", k)
 
@@ -29,6 +29,6 @@ func TestJSON(t *testing.T) {
 	assert.Equal(t, "keyint", k)
 	assert.Equal(t, "123456", v)
 
-	k, v, jtype = readJSON(&s)
+	_, _, jtype = readJSON(&s)
 	assert.True(t, jtype == jsonTErr)
 }

internal/querylog/qlog.go

@@ -1,13 +1,15 @@
+// Package querylog provides query log functions and interfaces.
 package querylog
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
 	"sync"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/miekg/dns"
 )
@@ -29,6 +31,33 @@ type queryLog struct {
 	fileWriteLock sync.Mutex
 }
 
+// ClientProto values are names of the client protocols.
+type ClientProto string
+
+// Client protocol names.
+const (
+	ClientProtoDOH   ClientProto = "doh"
+	ClientProtoDOQ   ClientProto = "doq"
+	ClientProtoDOT   ClientProto = "dot"
+	ClientProtoPlain ClientProto = ""
+)
+
+// NewClientProto validates that the client protocol name is valid and returns
+// the name as a ClientProto.
+func NewClientProto(s string) (cp ClientProto, err error) {
+	switch cp = ClientProto(s); cp {
+	case
+		ClientProtoDOH,
+		ClientProtoDOQ,
+		ClientProtoDOT,
+		ClientProtoPlain:
+
+		return cp, nil
+	default:
+		return "", fmt.Errorf("invalid client proto: %q", s)
+	}
+}
+
 // logEntry - represents a single log entry
 type logEntry struct {
 	IP   string    `json:"IP"` // Client IP
@@ -38,7 +67,7 @@ type logEntry struct {
 	QType  string `json:"QT"`
 	QClass string `json:"QC"`
 
-	ClientProto string `json:"CP"` // "" or "doh"
+	ClientProto ClientProto `json:"CP"`
 
 	Answer     []byte `json:",omitempty"` // sometimes empty answers happen like binerdunt.top or rev2.globalrootservers.net
 	OrigAnswer []byte `json:",omitempty"`
@@ -158,7 +187,6 @@ func (l *queryLog) Add(params AddParams) {
 			// writing to file is disabled - just remove the oldest entry from array
 			l.buffer = l.buffer[1:]
 		}
-
 	} else if !l.flushPending {
 		needFlush = len(l.buffer) >= int(l.conf.MemSize)
 		if needFlush {

internal/querylog/qlog_file.go

@@ -6,14 +6,16 @@ import (
 	"sync"
 	"time"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/agherr"
 	"github.com/AdguardTeam/golibs/log"
-
-	"github.com/pkg/errors"
 )
 
-// ErrSeekNotFound is returned from the Seek method
-// if we failed to find the desired record
-var ErrSeekNotFound = errors.New("Seek not found the record")
+// ErrSeekNotFound is returned from Seek if when it fails to find the requested
+// record.
+const ErrSeekNotFound agherr.Error = "seek: record not found"
+
+// ErrEndOfLog is returned from Seek when the end of the current log is reached.
+const ErrEndOfLog agherr.Error = "seek: end of log"
 
 // TODO: Find a way to grow buffer instead of relying on this value when reading strings
 const maxEntrySize = 16 * 1024
@@ -40,8 +42,7 @@ type QLogFile struct {
 
 // NewQLogFile initializes a new instance of the QLogFile
 func NewQLogFile(path string) (*QLogFile, error) {
-	f, err := os.OpenFile(path, os.O_RDONLY, 0644)
-
+	f, err := os.OpenFile(path, os.O_RDONLY, 0o644)
 	if err != nil {
 		return nil, err
 	}
@@ -107,6 +108,8 @@ func (q *QLogFile) Seek(timestamp int64) (int64, int, error) {
 			// the scope is too narrow and we won't find anything anymore
 			log.Error("querylog: didn't find timestamp:%v", timestamp)
 			return 0, depth, ErrSeekNotFound
+		} else if lineIdx == end && lineEndIdx == end {
+			return 0, depth, ErrEndOfLog
 		}
 
 		// Save the last found idx
@@ -228,7 +231,7 @@ func (q *QLogFile) readNextLine(position int64) (string, int64, error) {
 
 	// Look for the end of the prev line
 	// This is where we'll read from
-	var startLine = int64(0)
+	startLine := int64(0)
 	for i := relativePos - 1; i >= 0; i-- {
 		if q.buffer[i] == '\n' {
 			startLine = i + 1
@@ -294,7 +297,7 @@ func (q *QLogFile) readProbeLine(position int64) (string, int64, int64, error) {
 
 	// Now start looking for the new line character starting
 	// from the relativePos and going left
-	var startLine = int64(0)
+	startLine := int64(0)
 	for i := relativePos - 1; i >= 0; i-- {
 		if buffer[i] == '\n' {
 			startLine = i + 1
@@ -302,7 +305,7 @@ func (q *QLogFile) readProbeLine(position int64) (string, int64, int64, error) {
 		}
 	}
 	// Looking for the end of line now
-	var endLine = int64(bufferLen)
+	endLine := int64(bufferLen)
 	lineEndIdx := endLine + seekPosition
 	for i := relativePos; i < int64(bufferLen); i++ {
 		if buffer[i] == '\n' {