network/retrieve: add bzz-retrieve protocol (#1589)

* network/retrieve: initial commit

* network: import dependencies from stream package branch

* network/retrieve: address pr comments

* network/retrieve: fix pr comments

* network/retrieve: create logger for peer

* network: address pr comments

* network/retrieve: lint

* network/retrieve: prevent forever loop

* network/retrieve: address pr comments

* network/retrieve: fix linter

* network/retrieve: pr comments

* network/retrieval: pr comments

testutil/node.go

@@ -0,0 +1,58 @@
+// Copyright 2019 The Swarm Authors
+// This file is part of the Swarm library.
+//
+// The Swarm library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The Swarm library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the Swarm library. If not, see <http://www.gnu.org/licenses/>.
+
+package testutil
+
+import (
+	"net"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
+	"github.com/ethersphere/swarm/chunk"
+	"github.com/ethersphere/swarm/network"
+)
+
+// NodeConfigAtPo brute forces a node config to create a node that has an overlay address at the provided po in relation to the given baseaddr
+func NodeConfigAtPo(t *testing.T, baseaddr []byte, po int) *adapters.NodeConfig {
+	foundPo := -1
+	var conf *adapters.NodeConfig
+	for foundPo != po {
+		conf = adapters.RandomNodeConfig()
+		ip := net.IPv4(127, 0, 0, 1)
+		enrIP := enr.IP(ip)
+		conf.Record.Set(&enrIP)
+		enrTCPPort := enr.TCP(conf.Port)
+		conf.Record.Set(&enrTCPPort)
+		enrUDPPort := enr.UDP(0)
+		conf.Record.Set(&enrUDPPort)
+
+		err := enode.SignV4(&conf.Record, conf.PrivateKey)
+		if err != nil {
+			t.Fatalf("unable to generate ENR: %v", err)
+		}
+		nod, err := enode.New(enode.V4ID{}, &conf.Record)
+		if err != nil {
+			t.Fatalf("unable to create enode: %v", err)
+		}
+
+		n := network.NewAddr(nod)
+		foundPo = chunk.Proximity(baseaddr, n.Over())
+	}
+
+	return conf
+}