moved net stuff into subpkg

convert.go

+package net
+
+import (
+	"fmt"
+	"net"
+	"strings"
+
+	ma "github.com/jbenet/go-multiaddr"
+)
+
+var errIncorrectNetAddr = fmt.Errorf("incorrect network addr conversion")
+
+// FromNetAddr converts a net.Addr type to a Multiaddr.
+func FromNetAddr(a net.Addr) (ma.Multiaddr, error) {
+	switch a.Network() {
+	case "tcp", "tcp4", "tcp6":
+		ac, ok := a.(*net.TCPAddr)
+		if !ok {
+			return nil, errIncorrectNetAddr
+		}
+
+		// Get IP Addr
+		ipm, err := FromIP(ac.IP)
+		if err != nil {
+			return nil, errIncorrectNetAddr
+		}
+
+		// Get TCP Addr
+		tcpm, err := ma.NewMultiaddr(fmt.Sprintf("/tcp/%d", ac.Port))
+		if err != nil {
+			return nil, errIncorrectNetAddr
+		}
+
+		// Encapsulate
+		return ipm.Encapsulate(tcpm), nil
+
+	case "udp", "upd4", "udp6":
+		ac, ok := a.(*net.UDPAddr)
+		if !ok {
+			return nil, errIncorrectNetAddr
+		}
+
+		// Get IP Addr
+		ipm, err := FromIP(ac.IP)
+		if err != nil {
+			return nil, errIncorrectNetAddr
+		}
+
+		// Get UDP Addr
+		udpm, err := ma.NewMultiaddr(fmt.Sprintf("/udp/%d", ac.Port))
+		if err != nil {
+			return nil, errIncorrectNetAddr
+		}
+
+		// Encapsulate
+		return ipm.Encapsulate(udpm), nil
+
+	case "ip", "ip4", "ip6":
+		ac, ok := a.(*net.IPAddr)
+		if !ok {
+			return nil, errIncorrectNetAddr
+		}
+		return FromIP(ac.IP)
+
+	default:
+		return nil, fmt.Errorf("unknown network %v", a.Network())
+	}
+}
+
+// ToNetAddr converts a Multiaddr to a net.Addr
+// Must be ThinWaist. acceptable protocol stacks are:
+// /ip{4,6}/{tcp, udp}
+func ToNetAddr(maddr ma.Multiaddr) (net.Addr, error) {
+	network, host, err := DialArgs(maddr)
+	if err != nil {
+		return nil, err
+	}
+
+	switch network {
+	case "tcp":
+		return net.ResolveTCPAddr(network, host)
+	case "udp":
+		return net.ResolveUDPAddr(network, host)
+	case "ip":
+		return net.ResolveIPAddr(network, host)
+	}
+
+	return nil, fmt.Errorf("network not supported: %s", network)
+}
+
+// FromIP converts a net.IP type to a Multiaddr.
+func FromIP(ip net.IP) (ma.Multiaddr, error) {
+	switch {
+	case ip.To4() != nil:
+		return ma.NewMultiaddr("/ip4/" + ip.String())
+	case ip.To16() != nil:
+		return ma.NewMultiaddr("/ip6/" + ip.String())
+	default:
+		return nil, errIncorrectNetAddr
+	}
+}
+
+// DialArgs is a convenience function returning arguments for use in net.Dial
+func DialArgs(m ma.Multiaddr) (string, string, error) {
+	if !IsThinWaist(m) {
+		return "", "", fmt.Errorf("%s is not a 'thin waist' address", m)
+	}
+
+	str := m.String()
+	parts := strings.Split(str, "/")[1:]
+
+	if len(parts) == 2 { // only IP
+		return parts[0], parts[1], nil
+	}
+
+	network := parts[2]
+	var host string
+	switch parts[0] {
+	case "ip4":
+		host = strings.Join([]string{parts[1], parts[3]}, ":")
+	case "ip6":
+		host = fmt.Sprintf("[%s]:%s", parts[1], parts[3])
+	}
+	return network, host, nil
+}
+
+// IsThinWaist returns whether a Multiaddr starts with "Thin Waist" Protocols.
+// This means: /{IP4, IP6}[/{TCP, UDP}]
+func IsThinWaist(m ma.Multiaddr) bool {
+	p := m.Protocols()
+
+	// nothing? not even a waist.
+	if len(p) == 0 {
+		return false
+	}
+
+	if p[0].Code != ma.P_IP4 && p[0].Code != ma.P_IP6 {
+		return false
+	}
+
+	// only IP? still counts.
+	if len(p) == 1 {
+		return true
+	}
+
+	switch p[1].Code {
+	case ma.P_TCP, ma.P_UDP, ma.P_IP4, ma.P_IP6:
+		return true
+	default:
+		return false
+	}
+}

convert_test.go

+package net
+
+import (
+	"net"
+	"testing"
+
+	ma "github.com/jbenet/go-multiaddr"
+)
+
+type GenFunc func() (ma.Multiaddr, error)
+
+func testConvert(t *testing.T, s string, gen GenFunc) {
+	m, err := gen()
+	if err != nil {
+		t.Fatal("failed to generate.")
+	}
+
+	if s2 := m.String(); err != nil || s2 != s {
+		t.Fatal("failed to convert: " + s + " != " + s2)
+	}
+}
+
+func testToNetAddr(t *testing.T, maddr, ntwk, addr string) {
+	m, err := ma.NewMultiaddr(maddr)
+	if err != nil {
+		t.Fatal("failed to generate.")
+	}
+
+	naddr, err := ToNetAddr(m)
+	if addr == "" { // should fail
+		if err == nil {
+			t.Fatalf("failed to error: %s", m)
+		}
+		return
+	}
+
+	// shouldn't fail
+	if err != nil {
+		t.Fatalf("failed to convert to net addr: %s", m)
+	}
+
+	if naddr.String() != addr {
+		t.Fatalf("naddr.Address() == %s != %s", naddr, addr)
+	}
+
+	if naddr.Network() != ntwk {
+		t.Fatalf("naddr.Network() == %s != %s", naddr.Network(), ntwk)
+	}
+
+	// should convert properly
+	switch ntwk {
+	case "tcp":
+		_ = naddr.(*net.TCPAddr)
+	case "udp":
+		_ = naddr.(*net.UDPAddr)
+	case "ip":
+		_ = naddr.(*net.IPAddr)
+	}
+}
+
+func TestFromIP4(t *testing.T) {
+	testConvert(t, "/ip4/10.20.30.40", func() (ma.Multiaddr, error) {
+		return FromIP(net.ParseIP("10.20.30.40"))
+	})
+}
+
+func TestFromIP6(t *testing.T) {
+	testConvert(t, "/ip6/2001:4860:0:2001::68", func() (ma.Multiaddr, error) {
+		return FromIP(net.ParseIP("2001:4860:0:2001::68"))
+	})
+}
+
+func TestFromTCP(t *testing.T) {
+	testConvert(t, "/ip4/10.20.30.40/tcp/1234", func() (ma.Multiaddr, error) {
+		return FromNetAddr(&net.TCPAddr{
+			IP:   net.ParseIP("10.20.30.40"),
+			Port: 1234,
+		})
+	})
+}
+
+func TestFromUDP(t *testing.T) {
+	testConvert(t, "/ip4/10.20.30.40/udp/1234", func() (ma.Multiaddr, error) {
+		return FromNetAddr(&net.UDPAddr{
+			IP:   net.ParseIP("10.20.30.40"),
+			Port: 1234,
+		})
+	})
+}
+
+func TestThinWaist(t *testing.T) {
+	addrs := map[string]bool{
+		"/ip4/127.0.0.1/udp/1234":              true,
+		"/ip4/127.0.0.1/tcp/1234":              true,
+		"/ip4/127.0.0.1/udp/1234/tcp/1234":     true,
+		"/ip4/127.0.0.1/tcp/12345/ip4/1.2.3.4": true,
+		"/ip6/::1/tcp/80":                      true,
+		"/ip6/::1/udp/80":                      true,
+		"/ip6/::1":                             true,
+		"/tcp/1234/ip4/1.2.3.4":                false,
+		"/tcp/1234":                            false,
+		"/tcp/1234/udp/1234":                   false,
+		"/ip4/1.2.3.4/ip4/2.3.4.5":             true,
+		"/ip6/::1/ip4/2.3.4.5":                 true,
+	}
+
+	for a, res := range addrs {
+		m, err := ma.NewMultiaddr(a)
+		if err != nil {
+			t.Fatalf("failed to construct Multiaddr: %s", a)
+		}
+
+		if IsThinWaist(m) != res {
+			t.Fatalf("IsThinWaist(%s) != %v", a, res)
+		}
+	}
+}
+
+func TestDialArgs(t *testing.T) {
+	m, err := ma.NewMultiaddr("/ip4/127.0.0.1/udp/1234")
+	if err != nil {
+		t.Fatal("failed to construct", "/ip4/127.0.0.1/udp/1234")
+	}
+
+	nw, host, err := DialArgs(m)
+	if err != nil {
+		t.Fatal("failed to get dial args", "/ip4/127.0.0.1/udp/1234", err)
+	}
+
+	if nw != "udp" {
+		t.Error("failed to get udp network Dial Arg")
+	}
+
+	if host != "127.0.0.1:1234" {
+		t.Error("failed to get host:port Dial Arg")
+	}
+}