Pull request: 2799 trusted proxy

Merge in DNS/adguard-home from 2799-trusted-proxy to master

Updates #2799.

Squashed commit of the following:

commit 708a06b30116126a575767ea70865a6de90de774
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Fri Jul 23 18:56:16 2021 +0300

    all: add trusted proxy mechanism

CHANGELOG.md

@@ -42,6 +42,8 @@ and this project adheres to
 
 ### Changed
 
+- Proxied DNS-over-HTTPS queries are now only accepted from proxy servers on the
+  `trusted_proxies` list ([#2799]).
 - Clients who are blocked by access settings now receive a `REFUSED` response
   when a protocol other than DNS-over-UDP and DNSCrypt is used.
 - `querylog_interval` setting is now formatted in hours.
@@ -60,6 +62,7 @@ and this project adheres to
 
 ### Fixed
 
+- Wrong IP address for proxied DNS-over-HTTPS queries ([#2799]).
 - Domain name letter case mismatches in DNS rewrites ([#3351]).
 - Conflicts between IPv4 and IPv6 DNS rewrites ([#3343]).
 - Letter case mismatches in `CNAME` filtering ([#3335]).
@@ -89,6 +92,7 @@ and this project adheres to
 [#2504]: https://github.com/AdguardTeam/AdGuardHome/issues/2504
 [#2624]: https://github.com/AdguardTeam/AdGuardHome/issues/2624
 [#2763]: https://github.com/AdguardTeam/AdGuardHome/issues/2763
+[#2799]: https://github.com/AdguardTeam/AdGuardHome/issues/2799
 [#3012]: https://github.com/AdguardTeam/AdGuardHome/issues/3012
 [#3013]: https://github.com/AdguardTeam/AdGuardHome/issues/3013
 [#3136]: https://github.com/AdguardTeam/AdGuardHome/issues/3136

go.mod

@@ -3,7 +3,7 @@ module github.com/AdguardTeam/AdGuardHome
 go 1.16
 
 require (
-	github.com/AdguardTeam/dnsproxy v0.38.3
+	github.com/AdguardTeam/dnsproxy v0.39.0
 	github.com/AdguardTeam/golibs v0.8.0
 	github.com/AdguardTeam/urlfilter v0.14.6
 	github.com/NYTimes/gziphandler v1.1.1

go.sum

@@ -11,6 +11,8 @@ github.com/AdguardTeam/dhcp v0.0.0-20210519141215-51808c73c0bf h1:gc042VRSIRSUzZ
 github.com/AdguardTeam/dhcp v0.0.0-20210519141215-51808c73c0bf/go.mod h1:TKl4jN3Voofo4UJIicyNhWGp/nlQqQkFxmwIFTvBkKI=
 github.com/AdguardTeam/dnsproxy v0.38.3 h1:DvycTEOn2wuHmY+HE5XL4EnCV2EVbpREpbgZB06IJ0I=
 github.com/AdguardTeam/dnsproxy v0.38.3/go.mod h1:aNXKNdTyKfgAG2OS712SYSaGIM9AasZsZxfiY4YiR/0=
+github.com/AdguardTeam/dnsproxy v0.39.0 h1:5/PN2mpUeCTWtvqXUbSPTMJSOad4lJscPzm+C2f4jB4=
+github.com/AdguardTeam/dnsproxy v0.39.0/go.mod h1:aNXKNdTyKfgAG2OS712SYSaGIM9AasZsZxfiY4YiR/0=
 github.com/AdguardTeam/golibs v0.4.0/go.mod h1:skKsDKIBB7kkFflLJBpfGX+G8QFTx0WKUzB6TIgtUj4=
 github.com/AdguardTeam/golibs v0.4.2/go.mod h1:skKsDKIBB7kkFflLJBpfGX+G8QFTx0WKUzB6TIgtUj4=
 github.com/AdguardTeam/golibs v0.8.0 h1:rHo+yIgT2fivFG0yW2Cwk/DPc2+t/Aw6QvzPpiIFre0=
@@ -105,6 +107,7 @@ github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpO
 github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714 h1:/jC7qQFrv8CrSJVmaolDVOxTfS9kc36uB6H40kdbQq8=
 github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714/go.mod h1:2Goc3h8EklBH5mspfHFxBnEoURQCGzQQH1ga9Myjvis=
 github.com/jellevandenhooff/dkim v0.0.0-20150330215556-f50fe3d243e1/go.mod h1:E0B/fFc00Y+Rasa88328GlI/XbtyysCtTHZS8h7IrBU=
+github.com/jessevdk/go-flags v1.4.0 h1:4IU2WS7AumrZ/40jfhf4QVDMsQwqA7VEHozFRrGARJA=
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
 github.com/joomcode/errorx v1.0.1/go.mod h1:kgco15ekB6cs+4Xjzo7SPeXzx38PbJzBwbnu9qfVNHQ=
 github.com/joomcode/errorx v1.0.3 h1:3e1mi0u7/HTPNdg6d6DYyKGBhA5l9XpsfuVE29NxnWw=

internal/dnsforward/config.go

@@ -94,6 +94,11 @@ type FilteringConfig struct {
 	AllowedClients    []string `yaml:"allowed_clients"`    // IP addresses of whitelist clients
 	DisallowedClients []string `yaml:"disallowed_clients"` // IP addresses of clients that should be blocked
 	BlockedHosts      []string `yaml:"blocked_hosts"`      // hosts that should be blocked
+	// TrustedProxies is the list of IP addresses and CIDR networks to
+	// detect proxy servers addresses the DoH requests from which should be
+	// handled.  The value of nil or an empty slice for this field makes
+	// Proxy not trust any address.
+	TrustedProxies []string `yaml:"trusted_proxies"`
 
 	// DNS cache settings
 	// --
@@ -210,6 +215,7 @@ func (s *Server) createProxyConfig() (proxy.Config, error) {
 		Ratelimit:              int(s.conf.Ratelimit),
 		RatelimitWhitelist:     s.conf.RatelimitWhitelist,
 		RefuseAny:              s.conf.RefuseAny,
+		TrustedProxies:         s.conf.TrustedProxies,
 		CacheMinTTL:            s.conf.CacheMinTTL,
 		CacheMaxTTL:            s.conf.CacheMaxTTL,
 		CacheOptimistic:        s.conf.CacheOptimistic,

internal/dnsforward/dnsforward.go

@@ -227,6 +227,7 @@ func (s *Server) WriteDiskConfig(c *FilteringConfig) {
 	c.AllowedClients = aghstrings.CloneSlice(sc.AllowedClients)
 	c.DisallowedClients = aghstrings.CloneSlice(sc.DisallowedClients)
 	c.BlockedHosts = aghstrings.CloneSlice(sc.BlockedHosts)
+	c.TrustedProxies = aghstrings.CloneSlice(sc.TrustedProxies)
 	c.UpstreamDNS = aghstrings.CloneSlice(sc.UpstreamDNS)
 }
 

internal/home/config.go

@@ -179,6 +179,8 @@ var config = configuration{
 			RefuseAny:          true,
 			AllServers:         false,
 
+			TrustedProxies: []string{"127.0.0.0/8", "::1/128"},
+
 			// set default maximum concurrent queries to 300
 			// we introduced a default limit due to this:
 			// https://github.com/AdguardTeam/AdGuardHome/issues/2015#issuecomment-674041912