+ whois: add WHOIS information for a client

+ return WHOIS info in GET /clients response

home/dns.go

@@ -25,6 +25,8 @@ type dnsContext struct {
 	rdnsIP   map[string]bool
 	rdnsLock sync.Mutex        // synchronize access to rdnsIP
 	upstream upstream.Upstream // Upstream object for our own DNS server
+
+	whois *Whois
 }
 
 // initDNSServer creates an instance of the dnsforward.Server
@@ -56,6 +58,7 @@ func initDNSServer(baseDir string) {
 	config.Users = nil
 
 	initRDNS()
+	config.dnsctx.whois = initWhois(&config.clients)
 	initFiltering()
 }
 
@@ -63,6 +66,59 @@ func isRunning() bool {
 	return config.dnsServer != nil && config.dnsServer.IsRunning()
 }
 
+// Return TRUE if IP is within public Internet IP range
+func isPublicIP(ip net.IP) bool {
+	ip4 := ip.To4()
+	if ip4 != nil {
+		switch ip4[0] {
+		case 0:
+			return false //software
+		case 10:
+			return false //private network
+		case 127:
+			return false //loopback
+		case 169:
+			if ip4[1] == 254 {
+				return false //link-local
+			}
+		case 172:
+			if ip4[1] >= 16 && ip4[1] <= 31 {
+				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
+				return false
+			}
+		case 198:
+			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
+				return false
+			}
+		case 224:
+			if ip4[1] == 0 && ip4[2] == 0 { //multicast
+				return false
+			}
+		case 255:
+			if ip4[1] == 255 && ip4[2] == 255 && ip4[3] == 255 { //subnet
+				return false
+			}
+		}
+	} else {
+		if ip.IsLoopback() || ip.IsLinkLocalMulticast() || ip.IsLinkLocalUnicast() {
+			return false
+		}
+	}
+
+	return true
+}
+
 func onDNSRequest(d *proxy.DNSContext) {
 	qType := d.Req.Question[0].Qtype
 	if qType != dns.TypeA && qType != dns.TypeAAAA {
@@ -79,6 +135,9 @@ func onDNSRequest(d *proxy.DNSContext) {
 	if !ipAddr.IsLoopback() {
 		beginAsyncRDNS(ip)
 	}
+	if isPublicIP(ipAddr) {
+		config.dnsctx.whois.Begin(ip)
+	}
 }
 
 func generateServerConfig() (dnsforward.ServerConfig, error) {