Merge branch 'develop' of https://github.com/jarradh/eth-go into jarradh-develop

ethereum.go

@@ -263,20 +263,45 @@ func (s *Ethereum) Start() {
 
 	if ethutil.Config.Seed {
 		ethutil.Config.Log.Debugln("Seeding")
-		// Testnet seed bootstrapping
-		resp, err := http.Get("https://www.ethereum.org/servers.poc3.txt")
-		if err != nil {
-			log.Println("Fetching seed failed:", err)
-			return
-		}
-		defer resp.Body.Close()
-		body, err := ioutil.ReadAll(resp.Body)
-		if err != nil {
-			log.Println("Reading seed failed:", err)
-			return
-		}
+		// DNS Bootstrapping
+		_, nodes, err := net.LookupSRV("eth", "tcp", "ethereum.org")
+		if err == nil {
+			peers := []string{}
+			// Iterate SRV nodes
+			for _, n := range nodes {
+				target := n.Target
+				port := strconv.Itoa(int(n.Port))
+				// Resolve target to ip (Go returns list, so may resolve to multiple ips?)
+				addr, err := net.LookupHost(target)
+				if err == nil {
+					for _, a := range addr {
+						// Build string out of SRV port and Resolved IP
+						peer := net.JoinHostPort(a, port)
+						log.Println("Found DNS Bootstrap Peer:", peer)
+						peers = append(peers, peer)
+					}
+				} else {
+					log.Println("Couldn't resolve :", target)
+				}
+			}
+			// Connect to Peer list
+			s.ProcessPeerList(peers)
+		} else {
+			// Fallback to servers.poc3.txt
+			resp, err := http.Get("http://www.ethereum.org/servers.poc3.txt")
+			if err != nil {
+				log.Println("Fetching seed failed:", err)
+				return
+			}
+			defer resp.Body.Close()
+			body, err := ioutil.ReadAll(resp.Body)
+			if err != nil {
+				log.Println("Reading seed failed:", err)
+				return
+			}
 
-		s.ConnectToPeer(string(body))
+			s.ConnectToPeer(string(body))
+		}
 	}
 }