#48: Add local address information

goupnp.go

@@ -18,10 +18,12 @@ import (
 	"encoding/xml"
 	"fmt"
 	"io"
+	"net"
 	"net/http"
 	"net/url"
 	"time"
 
+	"github.com/huin/goupnp/httpu"
 	"github.com/huin/goupnp/ssdp"
 )
 
@@ -63,6 +65,9 @@ type MaybeRootDevice struct {
 	// the discovery of a device, regardless of if there was an error probing it.
 	Location *url.URL
 
+	// The address from which the device was discovered (if known - otherwise nil).
+	LocalAddr net.IP
+
 	// Any error encountered probing a discovered device.
 	Err error
 }
@@ -99,6 +104,9 @@ func DiscoverDevices(searchTarget string) ([]MaybeRootDevice, error) {
 		} else {
 			maybe.Root = root
 		}
+		if i := response.Header.Get(httpu.LocalAddressHeader); len(i) > 0 {
+			maybe.LocalAddr = net.ParseIP(i)
+		}
 	}
 
 	return results, nil

httpu/httpu.go

@@ -143,9 +143,16 @@ func (httpu *HTTPUClient) Do(
 			continue
 		}
 
+		// Set the related local address used to discover the device.
+		if a, ok := httpu.conn.LocalAddr().(*net.UDPAddr); ok {
+			response.Header.Add(LocalAddressHeader, a.IP.String())
+		}
+
 		responses = append(responses, response)
 	}
 
 	// Timeout reached - return discovered responses.
 	return responses, nil
 }
+
+const LocalAddressHeader = "goupnp-local-address"

service_client.go

@@ -2,6 +2,7 @@ package goupnp
 
 import (
 	"fmt"
+	"net"
 	"net/url"
 
 	"github.com/huin/goupnp/soap"
@@ -17,6 +18,7 @@ type ServiceClient struct {
 	RootDevice *RootDevice
 	Location   *url.URL
 	Service    *Service
+	localAddr  net.IP
 }
 
 // NewServiceClients discovers services, and returns clients for them. err will
@@ -36,7 +38,7 @@ func NewServiceClients(searchTarget string) (clients []ServiceClient, errors []e
 			continue
 		}
 
-		deviceClients, err := NewServiceClientsFromRootDevice(maybeRootDevice.Root, maybeRootDevice.Location, searchTarget)
+		deviceClients, err := newServiceClientsFromRootDevice(maybeRootDevice.Root, maybeRootDevice.Location, searchTarget, maybeRootDevice.LocalAddr)
 		if err != nil {
 			errors = append(errors, err)
 			continue
@@ -61,6 +63,15 @@ func NewServiceClientsByURL(loc *url.URL, searchTarget string) ([]ServiceClient,
 // a given root device. The loc parameter is simply assigned to the
 // Location attribute of the returned ServiceClient(s).
 func NewServiceClientsFromRootDevice(rootDevice *RootDevice, loc *url.URL, searchTarget string) ([]ServiceClient, error) {
+	return newServiceClientsFromRootDevice(rootDevice, loc, searchTarget, nil)
+}
+
+func newServiceClientsFromRootDevice(
+	rootDevice *RootDevice,
+	loc *url.URL,
+	searchTarget string,
+	lAddr net.IP,
+) ([]ServiceClient, error) {
 	device := &rootDevice.Device
 	srvs := device.FindService(searchTarget)
 	if len(srvs) == 0 {
@@ -75,6 +86,7 @@ func NewServiceClientsFromRootDevice(rootDevice *RootDevice, loc *url.URL, searc
 			RootDevice: rootDevice,
 			Location:   loc,
 			Service:    srv,
+			localAddr:  lAddr,
 		})
 	}
 	return clients, nil
@@ -86,3 +98,8 @@ func NewServiceClientsFromRootDevice(rootDevice *RootDevice, loc *url.URL, searc
 func (client *ServiceClient) GetServiceClient() *ServiceClient {
 	return client
 }
+
+// LocalAddr returns the address from which the device was discovered (if known - otherwise empty).
+func (client *ServiceClient) LocalAddr() net.IP {
+	return client.localAddr
+}