go.mod

@@ -3,7 +3,7 @@ module github.com/AdguardTeam/dnsproxy
 go 1.17
 
 require (
-	github.com/AdguardTeam/golibs v0.10.6
+	github.com/AdguardTeam/golibs v0.10.8
 	github.com/ameshkov/dnscrypt/v2 v2.2.3
 	github.com/ameshkov/dnsstamps v1.0.3
 	github.com/beefsack/go-rate v0.0.0-20200827232406-6cde80facd47

go.sum

@@ -8,8 +8,8 @@ dmitri.shuralyov.com/service/change v0.0.0-20181023043359-a85b471d5412/go.mod h1
 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/golibs v0.4.2/go.mod h1:skKsDKIBB7kkFflLJBpfGX+G8QFTx0WKUzB6TIgtUj4=
-github.com/AdguardTeam/golibs v0.10.6 h1:6UG6LxWFnG7TfjNzeApw+T68Kqqov0fcDYk9RjhTdhc=
-github.com/AdguardTeam/golibs v0.10.6/go.mod h1:rSfQRGHIdgfxriDDNgNJ7HmE5zRoURq8R+VdR81Zuzw=
+github.com/AdguardTeam/golibs v0.10.8 h1:diU9gP9qG1qeLbAkzIwfUerpHSqzR6zaBgzvRMR/m6Q=
+github.com/AdguardTeam/golibs v0.10.8/go.mod h1:rSfQRGHIdgfxriDDNgNJ7HmE5zRoURq8R+VdR81Zuzw=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da h1:KjTM2ks9d14ZYCvmHS9iAKVt9AyzRSqNU1qabPih5BY=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da/go.mod h1:eHEWzANqSiWQsof+nXEI9bUVUyV6F53Fp89EuCh2EAA=

proxy/helpers.go

@@ -155,55 +155,3 @@ func setECS(m *dns.Msg, ip net.IP, scope uint8) (subnet *net.IPNet) {
 
 	return subnet
 }
-
-// isPublicIP returns true if ip is within public Internet IP range.
-//
-// TODO(e.burkov, a.garipov):  Add an interface-based subnet detector to the
-// netutil.
-//
-// nolint (gocyclo)
-func isPublicIP(ip net.IP) (ok bool) {
-	if ip = ip.To4(); ip == nil {
-		return !ip.IsLoopback() && !ip.IsLinkLocalMulticast() && !ip.IsLinkLocalUnicast()
-	}
-
-	switch ip[0] {
-	case 0, 10, 127:
-		// Software, private network, loopback.
-		return false
-	case 169:
-		// Link-local.
-		return ip[1] != 254
-	case 172:
-		// Private network.
-		return ip[1] < 16 || ip[1] > 31
-	case 192:
-		switch ip[1] {
-		case 0:
-			// Private network, documentation.
-			return ip[2] != 0 && ip[2] != 2
-		case 88:
-			// Reserved.
-			return ip[2] != 99
-		case 168:
-			// Private network.
-			return false
-		default:
-			return true
-		}
-	case 198:
-		// Private network, documentation.
-		return (ip[1] != 18 && ip[2] != 19) && (ip[1] != 51 && ip[2] != 100)
-	case 203:
-		// Documentation.
-		return ip[1] != 0 || ip[2] != 113
-	case 224:
-		// Multicast.
-		return ip[1] != 0 || ip[2] != 0
-	case 255:
-		// Broadcast.
-		return ip[1] != 255 || ip[2] != 255 || ip[3] != 255
-	default:
-		return true
-	}
-}

proxy/proxy.go

@@ -525,7 +525,7 @@ func (dctx *DNSContext) processECS(cliIP net.IP) {
 		}
 	}
 
-	if isPublicIP(cliIP) {
+	if !netutil.IsSpecialPurpose(cliIP) {
 		// A Stub Resolver MUST set SCOPE PREFIX-LENGTH to 0.  See RFC 7871
 		// Section 6.
 		dctx.ReqECS = setECS(dctx.Req, cliIP, 0)