torsvc: Replace MultiNet with polymorphic Net interface

config.go

@@ -191,7 +191,7 @@ type config struct {
 	Alias string `long:"alias" description:"The node alias. Used as a moniker by peers and intelligence services"`
 	Color string `long:"color" description:"The color of the node in hex format (i.e. '#3399FF'). Used to customize node appearance in intelligence services"`
 
-	net *torsvc.MultiNet
+	net torsvc.Net
 }
 
 // loadConfig initializes and parses the config using a config file and command
@@ -301,7 +301,7 @@ func loadConfig() (*config, error) {
 	// functions. When Tor's proxy is specified, the dial function is set to
 	// the proxy specific dial function and the DNS resolution functions use
 	// Tor.
-	cfg.net = &torsvc.MultiNet{Tor: false}
+	cfg.net = &torsvc.RegularNet{}
 	if cfg.Tor.Socks != "" && cfg.Tor.DNS != "" {
 		// Validate Tor port number
 		torport, err := strconv.Atoi(cfg.Tor.Socks)
@@ -323,8 +323,10 @@ func loadConfig() (*config, error) {
 			return nil, err
 		}
 
-		cfg.net.TorDNS = cfg.Tor.DNS
+		cfg.net = &torsvc.TorProxyNet{
-		cfg.net.TorSocks = cfg.Tor.Socks
+			TorDNS:   cfg.Tor.DNS,
+			TorSocks: cfg.Tor.Socks,
+		}
 
 		// If we are using Tor, since we only want connections routed
 		// through Tor, listening is disabled.

torsvc/interface.go

@@ -4,10 +4,21 @@ import (
 	"net"
 )
 
-// Net is an interface housing a Dial function and several DNS functions.
+// Net is an interface housing a Dial function and several DNS functions, to
+// abstract the implementation of these functions over both Regular and Tor
 type Net interface {
+	// Dial accepts a network and address and returns a connection to a remote
+	// peer.
 	Dial(string, string) (net.Conn, error)
+
+	// LookupHost performs DNS resolution on a given hostname and returns
+	// addresses of that hostname
 	LookupHost(string) ([]string, error)
+
+	// LookupSRV allows a service and network to be specified and makes queries
+	// to a given DNS server for SRV queries.
 	LookupSRV(string, string, string) (string, []*net.SRV, error)
+
+	// ResolveTCPAddr is a used to resolve publicly advertised TCP addresses.
 	ResolveTCPAddr(string, string) (*net.TCPAddr, error)
 }

torsvc/net.go

@@ -5,54 +5,66 @@ import (
 	"net"
 )
 
-// MultiNet is an implementation of the Net interface that abstracts away the
+// RegularNet is an implementation of the Net interface that defines behaviour
-// "net" and "torsvc" functions from the user. This can be used to "switch"
+// for Regular network connections
-// Tor functionality on/off based on the MultiNet.Tor boolean. MultiNet allows
+type RegularNet struct{}
-// for callers to call net functions when necessary and torsvc functions when
-// necessary
-type MultiNet struct {
-	Tor      bool
-	TorDNS   string
-	TorSocks string
-}
 
-// A compile time check to ensure MultiNet implements the Net interface.
+// Dial on the regular network uses net.Dial
-var _ Net = (*MultiNet)(nil)
+func (r *RegularNet) Dial(network, address string) (net.Conn, error) {
-
-// Dial uses either the "net" or "torsvc" dial function.
-func (m *MultiNet) Dial(network, address string) (net.Conn, error) {
-	if m.Tor {
-		if network != "tcp" {
-			return nil, fmt.Errorf("Cannot dial non-tcp network via Tor")
-		}
-		return TorDial(address, m.TorSocks)
-	}
 	return net.Dial(network, address)
 }
 
-// LookupHost uses either the "net" or "torsvc LookupHost function.
+// LookupHost for regular network uses the net.LookupHost function
-func (m *MultiNet) LookupHost(host string) ([]string, error) {
+func (r *RegularNet) LookupHost(host string) ([]string, error) {
-	if m.Tor {
-		return TorLookupHost(host, m.TorSocks)
-	}
 	return net.LookupHost(host)
 }
 
-// LookupSRV uses either the "net" or "torsvc" LookupSRV function.
+// LookupSRV for regular network uses net.LookupSRV function
-func (m *MultiNet) LookupSRV(service, proto, name string) (string, []*net.SRV, error) {
+func (r *RegularNet) LookupSRV(service, proto, name string) (string, []*net.SRV, error) {
-	if m.Tor {
-		return TorLookupSRV(service, proto, name, m.TorSocks, m.TorDNS)
-	}
 	return net.LookupSRV(service, proto, name)
 }
 
-// ResolveTCPAddr uses either the "net" or "torsvc" ResolveTCP function.
+// ResolveTCPAddr for regular network uses net.ResolveTCPAddr function
-func (m *MultiNet) ResolveTCPAddr(network, address string) (*net.TCPAddr, error) {
+func (r *RegularNet) ResolveTCPAddr(network, address string) (*net.TCPAddr, error) {
-	if m.Tor {
-		if network != "tcp" {
-			return nil, fmt.Errorf("Cannot dial non-tcp network via Tor")
-		}
-		return TorResolveTCP(address, m.TorSocks)
-	}
 	return net.ResolveTCPAddr(network, address)
 }
+
+// TorProxyNet is an implementation of the Net interface that defines behaviour
+// for Tor network connections
+type TorProxyNet struct {
+	// TorDNS is the IP:PORT of the DNS server for Tor to use for SRV queries
+	TorDNS string
+
+	// TorSocks is the port which Tor's exposed SOCKS5 proxy is listening on.
+	// This is used for an outbound-only mode, so the node will not listen for
+	// incoming connections
+	TorSocks string
+}
+
+// Dial on the Tor network uses the torsvc TorDial() function, and requires
+// that network specified be tcp because only that is supported
+func (t *TorProxyNet) Dial(network, address string) (net.Conn, error) {
+	if network != "tcp" {
+		return nil, fmt.Errorf("Cannot dial non-tcp network via Tor")
+	}
+	return TorDial(address, t.TorSocks)
+}
+
+// LookupHost on Tor network uses the torsvc TorLookupHost function.
+func (t *TorProxyNet) LookupHost(host string) ([]string, error) {
+	return TorLookupHost(host, t.TorSocks)
+}
+
+// LookupSRV on Tor network uses the torsvc TorLookupHost function.
+func (t *TorProxyNet) LookupSRV(service, proto, name string) (string, []*net.SRV, error) {
+	return TorLookupSRV(service, proto, name, t.TorSocks, t.TorDNS)
+}
+
+// ResolveTCPAddr on Tor network uses the towsvc TorResolveTCP function, and
+// requires network to be "tcp" because only "tcp" is supported
+func (t *TorProxyNet) ResolveTCPAddr(network, address string) (*net.TCPAddr, error) {
+	if network != "tcp" {
+		return nil, fmt.Errorf("Cannot dial non-tcp network via Tor")
+	}
+	return TorResolveTCP(address, t.TorSocks)
+}