From be8b3122f94f12594f0e987e44374e9f1c6ea889 Mon Sep 17 00:00:00 2001
From: Lyndsay Roger <gombadi@users.noreply.github.com>
Date: Sat, 12 Sep 2015 15:16:22 +1200
Subject: [PATCH] Don't ask for remote addr if we are full and restrict number
 of addr from one node

---
 crawler.go | 15 ++++++++++++---
 network.go | 10 ++++++----
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/crawler.go b/crawler.go
index c4ba931..550b913 100644
--- a/crawler.go
+++ b/crawler.go
@@ -39,7 +39,7 @@ func crawlNode(s *dnsseeder, nd *node) {
 	}
 
 	// connect to the remote ip and ask them for their addr list
-	rna, e := crawlIP(s.pver, s.id, nd)
+	rna, e := crawlIP(s.pver, s.id, nd, s.isFull())
 
 	if e != nil {
 		// update the fact that we have not connected to this node
@@ -99,6 +99,8 @@ func crawlNode(s *dnsseeder, nd *node) {
 	nd.statusStr = "ok: received remote address list"
 
 	added := 0
+	// do not accept more than one third of maxSize addresses from one node
+	oneThird := int(float64(s.maxSize / 3))
 
 	// if we are full then skip adding more possible clients
 	if s.isFull() == false {
@@ -106,7 +108,9 @@ func crawlNode(s *dnsseeder, nd *node) {
 		for _, na := range rna {
 			// a new network address so add to the system
 			if x := s.addNa(na); x == true {
-				added++
+				if added++; added > oneThird {
+					break
+				}
 			}
 		}
 	}
@@ -136,7 +140,7 @@ func crawlEnd(nd *node) {
 }
 
 // crawlIP retrievs a slice of ip addresses from a client
-func crawlIP(pver uint32, netID wire.BitcoinNet, nd *node) ([]*wire.NetAddress, *crawlError) {
+func crawlIP(pver uint32, netID wire.BitcoinNet, nd *node, full bool) ([]*wire.NetAddress, *crawlError) {
 
 	ip := nd.na.IP.String()
 	port := strconv.Itoa(int(nd.na.Port))
@@ -221,6 +225,11 @@ func crawlIP(pver uint32, netID wire.BitcoinNet, nd *node) ([]*wire.NetAddress,
 		return nil, &crawlError{"Did not receive expected Ver Ack message from remote client", errors.New("")}
 	}
 
+	// if we get this far and if the seeder is full then don't ask for addresses. This will reduce bandwith usage while still
+	// confirming that we can connect to the remote node
+	if full {
+		return nil, nil
+	}
 	// send getaddr command
 	msgGetAddr := wire.NewMsgGetAddr()
 
diff --git a/network.go b/network.go
index 7e7cf7c..a7d6326 100644
--- a/network.go
+++ b/network.go
@@ -41,7 +41,7 @@ func createNetFile() {
 		Desc:       "Description of SeederNet",
 		SeederType: "Combined",
 		Secret:     "32bYTesoFSECretThAtiSASecrET!!",
-		Remote:     "ipofdnsserver.example.com:1234",
+		Remote:     "http://dnsserver.example.com:1234/updatedns",
 		Seeder1:    "seeder1.example.com",
 		Seeder2:    "seed1.bob.com",
 		Seeder3:    "seed2.example.com",
@@ -91,10 +91,12 @@ func initNetwork(jnw JNetwork) (*dnsseeder, error) {
 		return nil, errors.New(fmt.Sprintf("No DNS Hostname supplied"))
 	}
 
-	if ok := checkBlockSize(jnw.Secret); ok != true {
-		return nil, errors.New(fmt.Sprintf("shared secret must be either 16, 24 or 32 bytes long. currently: %v", len(jnw.Secret)))
+	// we only need a secret if we are a crawler or dns type
+	if needSecret := convertSeederType(jnw.SeederType); needSecret != typeCombined {
+		if ok := checkBlockSize(jnw.Secret); ok != true {
+			return nil, errors.New(fmt.Sprintf("shared secret must be either 16, 24 or 32 bytes long. currently: %v", len(jnw.Secret)))
+		}
 	}
-
 	if _, ok := config.seeders[jnw.Name]; ok {
 		return nil, errors.New(fmt.Sprintf("Name already exists from previous file - %s", jnw.Name))
 	}