Copy goupnp client into our repo

goupnp is an existing upnp client for go, which provides all the functionality we need, licensed
under BSD-2-Clause, so we can copy it over and modify parts of it for our case.
Specifically, we add contexts to all the methods so we can better handle timeouts, remove the
dependency on large charsets, and (eventually) trim out extra components we don't need.

Signed-off-by: julianknodt <julianknodt@gmail.com>

cmd/tailscale/depaware.txt

@@ -3,12 +3,6 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
    W 💣 github.com/alexbrainman/sspi                                 from github.com/alexbrainman/sspi/negotiate+
    W    github.com/alexbrainman/sspi/internal/common                 from github.com/alexbrainman/sspi/negotiate
    W 💣 github.com/alexbrainman/sspi/negotiate                       from tailscale.com/net/tshttpproxy
-        github.com/huin/goupnp                                       from github.com/huin/goupnp/dcps/internetgateway2
-        github.com/huin/goupnp/dcps/internetgateway2                 from tailscale.com/net/portmapper
-        github.com/huin/goupnp/httpu                                 from github.com/huin/goupnp+
-        github.com/huin/goupnp/scpd                                  from github.com/huin/goupnp
-        github.com/huin/goupnp/soap                                  from github.com/huin/goupnp+
-        github.com/huin/goupnp/ssdp                                  from github.com/huin/goupnp
         github.com/kballard/go-shellquote                            from tailscale.com/cmd/tailscale/cli
         github.com/peterbourgon/ff/v2                                from github.com/peterbourgon/ff/v2/ffcli
         github.com/peterbourgon/ff/v2/ffcli                          from tailscale.com/cmd/tailscale/cli
@@ -42,6 +36,12 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/net/tlsdial                                    from tailscale.com/derp/derphttp
         tailscale.com/net/tsaddr                                     from tailscale.com/net/interfaces+
      💣 tailscale.com/net/tshttpproxy                                from tailscale.com/derp/derphttp+
+        tailscale.com/net/upnp                                       from tailscale.com/net/upnp/dcps/internetgateway2
+        tailscale.com/net/upnp/dcps/internetgateway2                 from tailscale.com/net/portmapper
+        tailscale.com/net/upnp/httpu                                 from tailscale.com/net/upnp+
+        tailscale.com/net/upnp/scpd                                  from tailscale.com/net/upnp
+        tailscale.com/net/upnp/soap                                  from tailscale.com/net/upnp+
+        tailscale.com/net/upnp/ssdp                                  from tailscale.com/net/upnp
         tailscale.com/paths                                          from tailscale.com/cmd/tailscale/cli+
         tailscale.com/safesocket                                     from tailscale.com/cmd/tailscale/cli+
         tailscale.com/syncs                                          from tailscale.com/net/interfaces+
@@ -76,9 +76,6 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         golang.org/x/crypto/poly1305                                 from golang.org/x/crypto/chacha20poly1305+
         golang.org/x/crypto/salsa20/salsa                            from golang.org/x/crypto/nacl/box+
         golang.org/x/net/dns/dnsmessage                              from net
-        golang.org/x/net/html                                        from golang.org/x/net/html/charset
-        golang.org/x/net/html/atom                                   from golang.org/x/net/html
-        golang.org/x/net/html/charset                                from github.com/huin/goupnp
         golang.org/x/net/http/httpguts                               from net/http+
         golang.org/x/net/http/httpproxy                              from net/http
         golang.org/x/net/http2/hpack                                 from net/http
@@ -91,17 +88,6 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
   LD    golang.org/x/sys/unix                                        from tailscale.com/net/netns+
    W    golang.org/x/sys/windows                                     from golang.org/x/sys/windows/registry+
    W    golang.org/x/sys/windows/registry                            from golang.zx2c4.com/wireguard/windows/tunnel/winipcfg
-        golang.org/x/text/encoding                                   from golang.org/x/net/html/charset+
-        golang.org/x/text/encoding/charmap                           from golang.org/x/net/html/charset+
-        golang.org/x/text/encoding/htmlindex                         from golang.org/x/net/html/charset
-        golang.org/x/text/encoding/internal                          from golang.org/x/text/encoding/charmap+
-        golang.org/x/text/encoding/japanese                          from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/encoding/korean                            from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/encoding/simplifiedchinese                 from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/encoding/traditionalchinese                from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/encoding/unicode                           from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/language                                   from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/runes                                      from golang.org/x/text/encoding/unicode
         golang.org/x/text/secure/bidirule                            from golang.org/x/net/idna
         golang.org/x/text/transform                                  from golang.org/x/text/secure/bidirule+
         golang.org/x/text/unicode/bidi                               from golang.org/x/net/idna+

cmd/tailscaled/depaware.txt

@@ -10,12 +10,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
    L 💣 github.com/godbus/dbus/v5                                    from tailscale.com/net/dns
         github.com/golang/snappy                                     from github.com/klauspost/compress/zstd
         github.com/google/btree                                      from inet.af/netstack/tcpip/header+
-        github.com/huin/goupnp                                       from github.com/huin/goupnp/dcps/internetgateway2
-        github.com/huin/goupnp/dcps/internetgateway2                 from tailscale.com/net/portmapper
-        github.com/huin/goupnp/httpu                                 from github.com/huin/goupnp+
-        github.com/huin/goupnp/scpd                                  from github.com/huin/goupnp
-        github.com/huin/goupnp/soap                                  from github.com/huin/goupnp+
-        github.com/huin/goupnp/ssdp                                  from github.com/huin/goupnp
    L    github.com/josharian/native                                  from github.com/mdlayher/netlink+
    L 💣 github.com/jsimonetti/rtnetlink                              from tailscale.com/wgengine/monitor
    L    github.com/jsimonetti/rtnetlink/internal/unix                from github.com/jsimonetti/rtnetlink
@@ -118,6 +112,12 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/net/tsaddr                                     from tailscale.com/ipn/ipnlocal+
      💣 tailscale.com/net/tshttpproxy                                from tailscale.com/control/controlclient+
         tailscale.com/net/tstun                                      from tailscale.com/cmd/tailscaled+
+        tailscale.com/net/upnp                                       from tailscale.com/net/upnp/dcps/internetgateway2
+        tailscale.com/net/upnp/dcps/internetgateway2                 from tailscale.com/net/portmapper
+        tailscale.com/net/upnp/httpu                                 from tailscale.com/net/upnp+
+        tailscale.com/net/upnp/scpd                                  from tailscale.com/net/upnp
+        tailscale.com/net/upnp/soap                                  from tailscale.com/net/upnp+
+        tailscale.com/net/upnp/ssdp                                  from tailscale.com/net/upnp
         tailscale.com/paths                                          from tailscale.com/cmd/tailscaled+
         tailscale.com/portlist                                       from tailscale.com/ipn/ipnlocal
         tailscale.com/safesocket                                     from tailscale.com/ipn/ipnserver
@@ -176,9 +176,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         golang.org/x/crypto/salsa20/salsa                            from golang.org/x/crypto/nacl/box+
         golang.org/x/net/bpf                                         from github.com/mdlayher/netlink+
         golang.org/x/net/dns/dnsmessage                              from net+
-        golang.org/x/net/html                                        from golang.org/x/net/html/charset
-        golang.org/x/net/html/atom                                   from golang.org/x/net/html
-        golang.org/x/net/html/charset                                from github.com/huin/goupnp
         golang.org/x/net/http/httpguts                               from net/http+
         golang.org/x/net/http/httpproxy                              from net/http
         golang.org/x/net/http2/hpack                                 from net/http
@@ -196,17 +193,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
    W    golang.org/x/sys/windows/svc                                 from tailscale.com/cmd/tailscaled+
    W    golang.org/x/sys/windows/svc/mgr                             from tailscale.com/cmd/tailscaled
         golang.org/x/term                                            from tailscale.com/logpolicy
-        golang.org/x/text/encoding                                   from golang.org/x/net/html/charset+
-        golang.org/x/text/encoding/charmap                           from golang.org/x/net/html/charset+
-        golang.org/x/text/encoding/htmlindex                         from golang.org/x/net/html/charset
-        golang.org/x/text/encoding/internal                          from golang.org/x/text/encoding/charmap+
-        golang.org/x/text/encoding/japanese                          from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/encoding/korean                            from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/encoding/simplifiedchinese                 from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/encoding/traditionalchinese                from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/encoding/unicode                           from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/language                                   from golang.org/x/text/encoding/htmlindex
-        golang.org/x/text/runes                                      from golang.org/x/text/encoding/unicode
         golang.org/x/text/secure/bidirule                            from golang.org/x/net/idna
         golang.org/x/text/transform                                  from golang.org/x/text/secure/bidirule+
         golang.org/x/text/unicode/bidi                               from golang.org/x/net/idna+
@@ -252,7 +238,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         encoding/hex                                                 from crypto/x509+
         encoding/json                                                from expvar+
         encoding/pem                                                 from crypto/tls+
-        encoding/xml                                                 from github.com/huin/goupnp+
+        encoding/xml                                                 from tailscale.com/net/upnp+
         errors                                                       from bufio+
         expvar                                                       from tailscale.com/derp+
         flag                                                         from tailscale.com/cmd/tailscaled+

go.mod

@@ -16,7 +16,6 @@ require (
 	github.com/google/goexpect v0.0.0-20210430020637-ab937bf7fd6f
 	github.com/google/uuid v1.1.2
 	github.com/goreleaser/nfpm v1.10.3
-	github.com/huin/goupnp v1.0.0 // indirect
 	github.com/jsimonetti/rtnetlink v0.0.0-20210525051524-4cc836578190
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/klauspost/compress v1.12.2

go.sum

@@ -296,9 +296,6 @@ github.com/hashicorp/serf v0.8.2/go.mod h1:6hOLApaqBFA1NXqRQAsxw9QxuDEvNxSQRwA/J
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/huandu/xstrings v1.3.2 h1:L18LIDzqlW6xN2rEkpdV8+oL/IXWJ1APd+vsdYy4Wdw=
 github.com/huandu/xstrings v1.3.2/go.mod h1:y5/lhBue+AyNmUVz9RLU9xbLR0o4KIIExikq4ovT0aE=
-github.com/huin/goupnp v1.0.0 h1:wg75sLpL6DZqwHQN6E1Cfk6mtfzS45z8OV+ic+DtHRo=
-github.com/huin/goupnp v1.0.0/go.mod h1:n9v9KO1tAxYH82qOn+UTIFQDmx5n1Zxd/ClZDMX7Bnc=
-github.com/huin/goutil v0.0.0-20170803182201-1ca381bf3150/go.mod h1:PpLOETDnJ0o3iZrZfqZzyLl6l7F3c6L1oWn7OICBi6o=
 github.com/imdario/mergo v0.3.9/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
 github.com/imdario/mergo v0.3.11 h1:3tnifQM4i+fbajXKBHXWEH+KvNHqojZ778UH75j3bGA=
 github.com/imdario/mergo v0.3.11/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
@@ -720,7 +717,6 @@ golang.org/x/net v0.0.0-20201224014010-6772e930b67b/go.mod h1:m0MpNAwzfU5UDzcl9v
 golang.org/x/net v0.0.0-20210119194325-5f4716e94777/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
-golang.org/x/net v0.0.0-20210525063256-abc453219eb5 h1:wjuX4b5yYQnEQHzd+CBcrcC6OVR2J1CN6mUy0oSxIPo=
 golang.org/x/net v0.0.0-20210525063256-abc453219eb5/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20210610132358-84b48f89b13b h1:k+E048sYJHyVnsr1GDrRZWQ32D2C7lWs9JRc0bel53A=
 golang.org/x/net v0.0.0-20210610132358-84b48f89b13b/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=

net/portmapper/probe.go

@@ -12,11 +12,13 @@
 	"tailscale.com/net/netns"
 )
 
+/*
 type ProbeResult struct {
 	PCP  bool
 	PMP  bool
 	UPnP bool
 }
+*/
 
 // Probe returns a summary of which port mapping services are
 // available on the network.

net/portmapper/upnp.go

@@ -5,56 +5,26 @@
 
 import (
 	"context"
-	"sync"
+	"time"
 
-	"github.com/huin/goupnp/dcps/internetgateway2"
 	"golang.org/x/sync/errgroup"
+	"inet.af/netaddr"
+	"tailscale.com/net/upnp/dcps/internetgateway2"
 )
 
-// probeUPnP returns true if there are any upnp clients, or false with an error if none can be
+type upnpMapping struct {
-// found.
+	gw       netaddr.IP
-func probeUPnP(ctx context.Context) (bool, error) {
+	external netaddr.IPPort
-	wg := sync.WaitGroup{}
+	internal netaddr.IPPort
-	any := make(chan bool)
+	useUntil time.Time
-	errChan := make(chan error)
+	client   upnpClient
-	wg.Add(3)
+}
-	go func() {
-		ip1Clients, _, err := internetgateway2.NewWANIPConnection1Clients()
-		if len(ip1Clients) > 0 {
-			any <- true
-		}
-		wg.Done()
-		wg.Wait()
-		errChan <- err
-	}()
-	go func() {
-		ip2Clients, _, err := internetgateway2.NewWANIPConnection2Clients()
-		if len(ip2Clients) > 0 {
-			any <- true
-		}
-		wg.Done()
-		wg.Wait()
-		errChan <- err
-	}()
-	go func() {
-		ppp1Clients, _, err := internetgateway2.NewWANPPPConnection1Clients()
-		if len(ppp1Clients) > 0 {
-			any <- true
-		}
-		wg.Done()
-		wg.Wait()
-		errChan <- err
-	}()
 
-	select {
+func (u *upnpMapping) isCurrent() bool                { return u.useUntil.After(time.Now()) }
-	case <-any:
+func (u *upnpMapping) validUntil() time.Time          { return u.useUntil }
-		return true, nil
+func (u *upnpMapping) externalIPPort() netaddr.IPPort { return u.external }
-	case err := <-errChan:
+func (u *upnpMapping) release() {
-		// TODO probably want to take the non-nil of all the errors? Or something.
+	u.client.DeletePortMapping(context.Background(), "", u.external.Port(), "udp")
-		return false, err
-	case <-ctx.Done():
-		return false, nil
-	}
 }
 
 type upnpClient interface {
@@ -62,21 +32,61 @@ type upnpClient interface {
 	// Implicitly assume that the calls for all these are uniform, which might be a dangerous
 	// assumption.
 	AddPortMapping(
-		NewRemoteHost string,
+		ctx context.Context,
-		NewExternalPort uint16,
+		newRemoteHost string,
-		NewProtocol string,
+		newExternalPort uint16,
-		NewInternalPort uint16,
+		newProtocol string,
-		NewInternalClient string,
+		newInternalPort uint16,
-		NewEnabled bool,
+		newInternalClient string,
-		NewPortMappingDescription string,
+		newEnabled bool,
-		NewLeaseDuration uint32,
+		newPortMappingDescription string,
+		newLeaseDuration uint32,
 	) (err error)
 
-	DeletePortMapping(NewRemoteHost string, NewExternalPort uint16, NewProtocol string) error
+	DeletePortMapping(ctx context.Context, NewRemoteHost string, NewExternalPort uint16, NewProtocol string) error
-	GetStatusInfo() (status string, lastErr string, uptime uint32, err error)
+	GetStatusInfo(ctx context.Context) (status string, lastErr string, uptime uint32, err error)
 
-	RequestTermination() error
+	RequestTermination(ctx context.Context) error
-	RequestConnection() error
+	RequestConnection(ctx context.Context) error
+}
+
+func AddAnyPortMapping(
+	ctx context.Context,
+	upnp upnpClient,
+	newRemoteHost string,
+	newExternalPort uint16,
+	newProtocol string,
+	newInternalPort uint16,
+	newInternalClient string,
+	newEnabled bool,
+	newPortMappingDescription string,
+	newLeaseDuration uint32,
+) (newPort uint16, err error) {
+	if upnp, ok := upnp.(*internetgateway2.WANIPConnection2); ok {
+		return upnp.AddAnyPortMapping(
+			ctx,
+			newRemoteHost,
+			newExternalPort,
+			newProtocol,
+			newInternalPort,
+			newInternalClient,
+			newEnabled,
+			newPortMappingDescription,
+			newLeaseDuration,
+		)
+	}
+	err = upnp.AddPortMapping(
+		ctx,
+		newRemoteHost,
+		newExternalPort,
+		newProtocol,
+		newInternalPort,
+		newInternalClient,
+		newEnabled,
+		newPortMappingDescription,
+		newLeaseDuration,
+	)
+	return newInternalPort, err
 }
 
 // getUPnPClients gets a client for interfacing with UPnP, ignoring the underlying protocol for

net/upnp/LICENSE

@@ -0,0 +1,23 @@
+Copyright (c) 2013, John Beisley <johnbeisleyuk@gmail.com>
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice, this
+  list of conditions and the following disclaimer in the documentation and/or
+  other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

net/upnp/README.md

@@ -0,0 +1,46 @@
+goupnp is a UPnP client library for Go
+
+## Installation
+
+Run `go get -u github.com/huin/goupnp`.
+
+## Documentation
+
+See [GUIDE.md](GUIDE.md) for a quick start on the most common use case for this
+library.
+
+Supported DCPs (you probably want to start with one of these):
+
+- [![GoDoc](https://godoc.org/github.com/huin/goupnp?status.svg) av1](https://godoc.org/github.com/huin/goupnp/dcps/av1) - Client for UPnP Device Control Protocol MediaServer v1 and MediaRenderer v1.
+- [![GoDoc](https://godoc.org/github.com/huin/goupnp?status.svg) internetgateway1](https://godoc.org/github.com/huin/goupnp/dcps/internetgateway1) - Client for UPnP Device Control Protocol Internet Gateway Device v1.
+- [![GoDoc](https://godoc.org/github.com/huin/goupnp?status.svg) internetgateway2](https://godoc.org/github.com/huin/goupnp/dcps/internetgateway2) - Client for UPnP Device Control Protocol Internet Gateway Device v2.
+
+Core components:
+
+- [![GoDoc](https://godoc.org/github.com/huin/goupnp?status.svg) (goupnp)](https://godoc.org/github.com/huin/goupnp) core library - contains datastructures and utilities typically used by the implemented DCPs.
+- [![GoDoc](https://godoc.org/github.com/huin/goupnp?status.svg) httpu](https://godoc.org/github.com/huin/goupnp/httpu) HTTPU implementation, underlies SSDP.
+- [![GoDoc](https://godoc.org/github.com/huin/goupnp?status.svg) ssdp](https://godoc.org/github.com/huin/goupnp/ssdp) SSDP client implementation (simple service discovery protocol) - used to discover UPnP services on a network.
+- [![GoDoc](https://godoc.org/github.com/huin/goupnp?status.svg) soap](https://godoc.org/github.com/huin/goupnp/soap) SOAP client implementation (simple object access protocol) - used to communicate with discovered services.
+
+## Regenerating dcps generated source code:
+
+1. Build code generator:
+
+   `go get -u github.com/huin/goupnp/cmd/goupnpdcpgen`
+
+2. Regenerate the code:
+
+   `go generate ./...`
+
+## Supporting additional UPnP devices and services:
+
+Supporting additional services is, in the trivial case, simply a matter of
+adding the service to the `dcpMetadata` whitelist in `cmd/goupnpdcpgen/metadata.go`,
+regenerating the source code (see above), and committing that source code.
+
+However, it would be helpful if anyone needing such a service could test the
+service against the service they have, and then reporting any trouble
+encountered as an [issue on this
+project](https://github.com/huin/goupnp/issues/new). If it just works, then
+please report at least minimal working functionality as an issue, and
+optionally contribute the metadata upstream.

net/upnp/cmd/goupnpdcpgen/codetemplate.go

@@ -0,0 +1,154 @@
+package main
+
+import (
+	"html/template"
+)
+
+var packageTmpl = template.Must(template.New("package").Parse(`{{$name := .Metadata.Name}}
+// Client for UPnP Device Control Protocol {{.Metadata.OfficialName}}.
+// {{if .Metadata.DocURL}}
+// This DCP is documented in detail at: {{.Metadata.DocURL}}{{end}}
+//
+// Typically, use one of the New* functions to create clients for services.
+package {{$name}}
+
+// ***********************************************************
+// GENERATED FILE - DO NOT EDIT BY HAND. See README.md
+// ***********************************************************
+
+import (
+  "context"
+	"net/url"
+	"time"
+
+	"tailscale.com/net/upnp"
+	"tailscale.com/net/upnp/soap"
+)
+
+// Hack to avoid Go complaining if time isn't used.
+var _ time.Time
+
+// Device URNs:
+const ({{range .DeviceTypes}}
+	{{.Const}} = "{{.URN}}"{{end}}
+)
+
+// Service URNs:
+const ({{range .ServiceTypes}}
+	{{.Const}} = "{{.URN}}"{{end}}
+)
+
+{{range .Services}}
+{{$srv := .}}
+{{$srvIdent := printf "%s%s" .Name .Version}}
+
+// {{$srvIdent}} is a client for UPnP SOAP service with URN "{{.URN}}". See
+// goupnp.ServiceClient, which contains RootDevice and Service attributes which
+// are provided for informational value.
+type {{$srvIdent}} struct {
+	goupnp.ServiceClient
+}
+
+// New{{$srvIdent}}Clients discovers instances of the service on the network,
+// and returns clients to any that are found. errors will contain an error for
+// any devices that replied but which could not be queried, and err will be set
+// if the discovery process failed outright.
+//
+// This is a typical entry calling point into this package.
+func New{{$srvIdent}}Clients() (clients []*{{$srvIdent}}, errors []error, err error) {
+	var genericClients []goupnp.ServiceClient
+	if genericClients, errors, err = goupnp.NewServiceClients({{$srv.Const}}); err != nil {
+		return
+	}
+	clients = new{{$srvIdent}}ClientsFromGenericClients(genericClients)
+	return
+}
+
+// New{{$srvIdent}}ClientsByURL discovers instances of the service at the given
+// URL, and returns clients to any that are found. An error is returned if
+// there was an error probing the service.
+//
+// This is a typical entry calling point into this package when reusing an
+// previously discovered service URL.
+func New{{$srvIdent}}ClientsByURL(loc *url.URL) ([]*{{$srvIdent}}, error) {
+	genericClients, err := goupnp.NewServiceClientsByURL(loc, {{$srv.Const}})
+	if err != nil {
+		return nil, err
+	}
+	return new{{$srvIdent}}ClientsFromGenericClients(genericClients), nil
+}
+
+// New{{$srvIdent}}ClientsFromRootDevice discovers instances of the service in
+// a given root device, and returns clients to any that are found. An error is
+// returned if there was not at least one instance of the service within the
+// device. The location parameter is simply assigned to the Location attribute
+// of the wrapped ServiceClient(s).
+//
+// This is a typical entry calling point into this package when reusing an
+// previously discovered root device.
+func New{{$srvIdent}}ClientsFromRootDevice(rootDevice *goupnp.RootDevice, loc *url.URL) ([]*{{$srvIdent}}, error) {
+	genericClients, err := goupnp.NewServiceClientsFromRootDevice(rootDevice, loc, {{$srv.Const}})
+	if err != nil {
+		return nil, err
+	}
+	return new{{$srvIdent}}ClientsFromGenericClients(genericClients), nil
+}
+
+func new{{$srvIdent}}ClientsFromGenericClients(genericClients []goupnp.ServiceClient) []*{{$srvIdent}} {
+	clients := make([]*{{$srvIdent}}, len(genericClients))
+	for i := range genericClients {
+		clients[i] = &{{$srvIdent}}{genericClients[i]}
+	}
+	return clients
+}
+
+{{range .SCPD.Actions}}{{/* loops over *SCPDWithURN values */}}
+
+{{$winargs := $srv.WrapArguments .InputArguments}}
+{{$woutargs := $srv.WrapArguments .OutputArguments}}
+{{if $winargs.HasDoc}}
+//
+// Arguments:{{range $winargs}}{{if .HasDoc}}
+//
+// * {{.Name}}: {{.Document}}{{end}}{{end}}{{end}}
+{{if $woutargs.HasDoc}}
+//
+// Return values:{{range $woutargs}}{{if .HasDoc}}
+//
+// * {{.Name}}: {{.Document}}{{end}}{{end}}{{end}}
+func (client *{{$srvIdent}}) {{.Name}}(ctx context.Context, {{range $winargs -}}
+{{.AsParameter}}, {{end -}}
+) ({{range $woutargs -}}
+{{.AsParameter}}, {{end}} err error) {
+	// Request structure.
+	request := {{if $winargs}}&{{template "argstruct" $winargs}}{{"{}"}}{{else}}{{"interface{}(nil)"}}{{end}}
+	// BEGIN Marshal arguments into request.
+{{range $winargs}}
+	if request.{{.Name}}, err = {{.Marshal}}; err != nil {
+		return
+	}{{end}}
+	// END Marshal arguments into request.
+
+	// Response structure.
+	response := {{if $woutargs}}&{{template "argstruct" $woutargs}}{{"{}"}}{{else}}{{"interface{}(nil)"}}{{end}}
+
+	// Perform the SOAP call.
+	if err = client.SOAPClient.PerformAction(ctx, {{$srv.URNParts.Const}}, "{{.Name}}", request, response); err != nil {
+		return
+	}
+
+	// BEGIN Unmarshal arguments from response.
+{{range $woutargs}}
+	if {{.Name}}, err = {{.Unmarshal "response"}}; err != nil {
+		return
+	}{{end}}
+	// END Unmarshal arguments from response.
+	return
+}
+{{end}}
+{{end}}
+
+{{define "argstruct"}}struct {{"{"}}
+{{range .}}{{.Name}} string
+{{end}}{{"}"}}{{end}}
+`))

net/upnp/cmd/goupnpdcpgen/dcp.go

@@ -0,0 +1,265 @@
+package main
+
+import (
+	"archive/zip"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"strings"
+
+	"tailscale.com/net/upnp"
+	"tailscale.com/net/upnp/scpd"
+)
+
+// DCP collects together information about a UPnP Device Control Protocol.
+type DCP struct {
+	Metadata     DCPMetadata
+	DeviceTypes  map[string]*URNParts
+	ServiceTypes map[string]*URNParts
+	Services     []SCPDWithURN
+}
+
+func newDCP(metadata DCPMetadata) *DCP {
+	return &DCP{
+		Metadata:     metadata,
+		DeviceTypes:  make(map[string]*URNParts),
+		ServiceTypes: make(map[string]*URNParts),
+	}
+}
+
+func (dcp *DCP) processZipFile(filename string) error {
+	archive, err := zip.OpenReader(filename)
+	if err != nil {
+		return fmt.Errorf("error reading zip file %q: %v", filename, err)
+	}
+	defer archive.Close()
+	for _, deviceFile := range globFiles("*/device/*.xml", archive) {
+		if err := dcp.processDeviceFile(deviceFile); err != nil {
+			return err
+		}
+	}
+	for _, scpdFile := range globFiles("*/service/*.xml", archive) {
+		if err := dcp.processSCPDFile(scpdFile); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (dcp *DCP) processDeviceFile(file *zip.File) error {
+	var device goupnp.Device
+	if err := unmarshalXmlFile(file, &device); err != nil {
+		return fmt.Errorf("error decoding device XML from file %q: %v", file.Name, err)
+	}
+	var mainErr error
+	device.VisitDevices(func(d *goupnp.Device) {
+		t := strings.TrimSpace(d.DeviceType)
+		if t != "" {
+			u, err := extractURNParts(t, deviceURNPrefix)
+			if err != nil {
+				mainErr = err
+			}
+			dcp.DeviceTypes[t] = u
+		}
+	})
+	device.VisitServices(func(s *goupnp.Service) {
+		u, err := extractURNParts(s.ServiceType, serviceURNPrefix)
+		if err != nil {
+			mainErr = err
+		}
+		dcp.ServiceTypes[s.ServiceType] = u
+	})
+	return mainErr
+}
+
+func (dcp *DCP) writeCode(outFile string, useGofmt bool) error {
+	packageFile, err := os.Create(outFile)
+	if err != nil {
+		return err
+	}
+	var output io.WriteCloser = packageFile
+	if useGofmt {
+		if output, err = NewGofmtWriteCloser(output); err != nil {
+			packageFile.Close()
+			return err
+		}
+	}
+	if err = packageTmpl.Execute(output, dcp); err != nil {
+		output.Close()
+		return err
+	}
+	return output.Close()
+}
+
+func (dcp *DCP) processSCPDFile(file *zip.File) error {
+	scpd := new(scpd.SCPD)
+	if err := unmarshalXmlFile(file, scpd); err != nil {
+		return fmt.Errorf("error decoding SCPD XML from file %q: %v", file.Name, err)
+	}
+	scpd.Clean()
+	urnParts, err := urnPartsFromSCPDFilename(file.Name)
+	if err != nil {
+		return fmt.Errorf("could not recognize SCPD filename %q: %v", file.Name, err)
+	}
+	dcp.Services = append(dcp.Services, SCPDWithURN{
+		URNParts: urnParts,
+		SCPD:     scpd,
+	})
+	return nil
+}
+
+type SCPDWithURN struct {
+	*URNParts
+	SCPD *scpd.SCPD
+}
+
+func (s *SCPDWithURN) WrapArguments(args []*scpd.Argument) (argumentWrapperList, error) {
+	wrappedArgs := make(argumentWrapperList, len(args))
+	for i, arg := range args {
+		wa, err := s.wrapArgument(arg)
+		if err != nil {
+			return nil, err
+		}
+		wrappedArgs[i] = wa
+	}
+	return wrappedArgs, nil
+}
+
+func (s *SCPDWithURN) wrapArgument(arg *scpd.Argument) (*argumentWrapper, error) {
+	relVar := s.SCPD.GetStateVariable(arg.RelatedStateVariable)
+	if relVar == nil {
+		return nil, fmt.Errorf("no such state variable: %q, for argument %q", arg.RelatedStateVariable, arg.Name)
+	}
+	cnv, ok := typeConvs[relVar.DataType.Name]
+	if !ok {
+		return nil, fmt.Errorf("unknown data type: %q, for state variable %q, for argument %q", relVar.DataType.Type, arg.RelatedStateVariable, arg.Name)
+	}
+	return &argumentWrapper{
+		Argument: *arg,
+		relVar:   relVar,
+		conv:     cnv,
+	}, nil
+}
+
+type argumentWrapper struct {
+	scpd.Argument
+	relVar *scpd.StateVariable
+	conv   conv
+}
+
+func (arg *argumentWrapper) AsParameter() string {
+	return fmt.Sprintf("%s %s", arg.Name, arg.conv.ExtType)
+}
+
+func (arg *argumentWrapper) HasDoc() bool {
+	rng := arg.relVar.AllowedValueRange
+	return ((rng != nil && (rng.Minimum != "" || rng.Maximum != "" || rng.Step != "")) ||
+		len(arg.relVar.AllowedValues) > 0)
+}
+
+func (arg *argumentWrapper) Document() string {
+	relVar := arg.relVar
+	if rng := relVar.AllowedValueRange; rng != nil {
+		var parts []string
+		if rng.Minimum != "" {
+			parts = append(parts, fmt.Sprintf("minimum=%s", rng.Minimum))
+		}
+		if rng.Maximum != "" {
+			parts = append(parts, fmt.Sprintf("maximum=%s", rng.Maximum))
+		}
+		if rng.Step != "" {
+			parts = append(parts, fmt.Sprintf("step=%s", rng.Step))
+		}
+		return "allowed value range: " + strings.Join(parts, ", ")
+	}
+	if len(relVar.AllowedValues) != 0 {
+		return "allowed values: " + strings.Join(relVar.AllowedValues, ", ")
+	}
+	return ""
+}
+
+func (arg *argumentWrapper) Marshal() string {
+	return fmt.Sprintf("soap.Marshal%s(%s)", arg.conv.FuncSuffix, arg.Name)
+}
+
+func (arg *argumentWrapper) Unmarshal(objVar string) string {
+	return fmt.Sprintf("soap.Unmarshal%s(%s.%s)", arg.conv.FuncSuffix, objVar, arg.Name)
+}
+
+type argumentWrapperList []*argumentWrapper
+
+func (args argumentWrapperList) HasDoc() bool {
+	for _, arg := range args {
+		if arg.HasDoc() {
+			return true
+		}
+	}
+	return false
+}
+
+type URNParts struct {
+	URN     string
+	Name    string
+	Version string
+}
+
+func (u *URNParts) Const() string {
+	return fmt.Sprintf("URN_%s_%s", u.Name, u.Version)
+}
+
+// extractURNParts extracts the name and version from a URN string.
+func extractURNParts(urn, expectedPrefix string) (*URNParts, error) {
+	if !strings.HasPrefix(urn, expectedPrefix) {
+		return nil, fmt.Errorf("%q does not have expected prefix %q", urn, expectedPrefix)
+	}
+	parts := strings.SplitN(strings.TrimPrefix(urn, expectedPrefix), ":", 2)
+	if len(parts) != 2 {
+		return nil, fmt.Errorf("%q does not have a name and version", urn)
+	}
+	name, version := parts[0], parts[1]
+	return &URNParts{urn, name, version}, nil
+}
+
+// Taken from: https://github.com/huin/goutil/blob/master/codegen/gofmt.go
+// License: https://github.com/huin/goutil/blob/master/LICENSE
+// NewGofmtWriteCloser returns an io.WriteCloser that filters what is written
+// to it through gofmt. It must be closed for this process to be completed, an
+// error from Close can be due to syntax errors in the source that has been
+// written.
+type goFmtWriteCloser struct {
+	output io.WriteCloser
+	stdin  io.WriteCloser
+	gofmt  *exec.Cmd
+}
+
+func NewGofmtWriteCloser(output io.WriteCloser) (io.WriteCloser, error) {
+	gofmt := exec.Command("gofmt")
+	gofmt.Stdout = output
+	gofmt.Stderr = os.Stderr
+	stdin, err := gofmt.StdinPipe()
+	if err != nil {
+		return nil, err
+	}
+	if err = gofmt.Start(); err != nil {
+		return nil, err
+	}
+	return &goFmtWriteCloser{
+		output: output,
+		stdin:  stdin,
+		gofmt:  gofmt,
+	}, nil
+}
+
+func (gwc *goFmtWriteCloser) Write(p []byte) (int, error) {
+	return gwc.stdin.Write(p)
+}
+
+func (gwc *goFmtWriteCloser) Close() error {
+	gwc.stdin.Close()
+	if err := gwc.output.Close(); err != nil {
+		gwc.gofmt.Wait()
+		return err
+	}
+	return gwc.gofmt.Wait()
+}

net/upnp/cmd/goupnpdcpgen/fileutil.go

@@ -0,0 +1,88 @@
+package main
+
+import (
+	"archive/zip"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path"
+	"regexp"
+)
+
+func acquireFile(specFilename string, xmlSpecURL string) error {
+	if f, err := os.Open(specFilename); err != nil {
+		if !os.IsNotExist(err) {
+			return err
+		}
+	} else {
+		f.Close()
+		return nil
+	}
+
+	resp, err := http.Get(xmlSpecURL)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("could not download spec %q from %q: %s",
+			specFilename, xmlSpecURL, resp.Status)
+	}
+
+	tmpFilename := specFilename + ".download"
+	w, err := os.Create(tmpFilename)
+	if err != nil {
+		return err
+	}
+	defer w.Close()
+
+	_, err = io.Copy(w, resp.Body)
+	if err != nil {
+		return err
+	}
+
+	return os.Rename(tmpFilename, specFilename)
+}
+
+func globFiles(pattern string, archive *zip.ReadCloser) []*zip.File {
+	var files []*zip.File
+	for _, f := range archive.File {
+		if matched, err := path.Match(pattern, f.Name); err != nil {
+			// This shouldn't happen - all patterns are hard-coded, errors in them
+			// are a programming error.
+			panic(err)
+		} else if matched {
+			files = append(files, f)
+		}
+	}
+	return files
+}
+
+func unmarshalXmlFile(file *zip.File, data interface{}) error {
+	r, err := file.Open()
+	if err != nil {
+		return err
+	}
+	decoder := xml.NewDecoder(r)
+	defer r.Close()
+	return decoder.Decode(data)
+}
+
+var scpdFilenameRe = regexp.MustCompile(
+	`.*/([a-zA-Z0-9]+)([0-9]+)\.xml`)
+
+func urnPartsFromSCPDFilename(filename string) (*URNParts, error) {
+	parts := scpdFilenameRe.FindStringSubmatch(filename)
+	if len(parts) != 3 {
+		return nil, fmt.Errorf("SCPD filename %q does not have expected number of parts", filename)
+	}
+	name, version := parts[1], parts[2]
+	return &URNParts{
+		URN:     serviceURNPrefix + name + ":" + version,
+		Name:    name,
+		Version: version,
+	}, nil
+}

net/upnp/cmd/goupnpdcpgen/goupnpdcpgen.go

@@ -0,0 +1,64 @@
+// Command to generate DCP package source from the XML specification.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+)
+
+var (
+	deviceURNPrefix  = "urn:schemas-upnp-org:device:"
+	serviceURNPrefix = "urn:schemas-upnp-org:service:"
+)
+
+func main() {
+	var (
+		dcpName  = flag.String("dcp_name", "", "Name of the DCP to generate.")
+		specsDir = flag.String("specs_dir", ".", "Path to the specification storage directory. "+
+			"This is used to find (and download if not present) the specification ZIP files.")
+		useGofmt = flag.Bool("gofmt", true, "Pass the generated code through gofmt. "+
+			"Disable this if debugging code generation and needing to see the generated code "+
+			"prior to being passed through gofmt.")
+	)
+	flag.Parse()
+
+	if err := run(*dcpName, *specsDir, *useGofmt); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func run(dcpName, specsDir string, useGofmt bool) error {
+	if err := os.MkdirAll(specsDir, os.ModePerm); err != nil {
+		return fmt.Errorf("could not create specs-dir %q: %v", specsDir, err)
+	}
+
+	for _, d := range dcpMetadata {
+		if d.Name != dcpName {
+			continue
+		}
+		specFilename := filepath.Join(specsDir, d.Name+".zip")
+		err := acquireFile(specFilename, d.XMLSpecURL)
+		if err != nil {
+			return fmt.Errorf("could not acquire spec for %s: %v", d.Name, err)
+		}
+		dcp := newDCP(d)
+		if err := dcp.processZipFile(specFilename); err != nil {
+			return fmt.Errorf("error processing spec for %s in file %q: %v", d.Name, specFilename, err)
+		}
+		for i, hack := range d.Hacks {
+			if err := hack(dcp); err != nil {
+				return fmt.Errorf("error with Hack[%d] for %s: %v", i, d.Name, err)
+			}
+		}
+		if err := dcp.writeCode(d.Name+".go", useGofmt); err != nil {
+			return fmt.Errorf("error writing package %q: %v", dcp.Metadata.Name, err)
+		}
+
+		return nil
+	}
+
+	return fmt.Errorf("could not find DCP with name %q", dcpName)
+}

net/upnp/cmd/goupnpdcpgen/metadata.go

@@ -0,0 +1,69 @@
+package main
+
+// DCP contains extra metadata to use when generating DCP source files.
+type DCPMetadata struct {
+	Name         string // What to name the Go DCP package.
+	OfficialName string // Official name for the DCP.
+	DocURL       string // Optional - URL for further documentation about the DCP.
+	XMLSpecURL   string // Where to download the XML spec from.
+	// Any special-case functions to run against the DCP before writing it out.
+	Hacks []DCPHackFn
+}
+
+var dcpMetadata = []DCPMetadata{
+	{
+		Name:         "internetgateway1",
+		OfficialName: "Internet Gateway Device v1",
+		DocURL:       "http://upnp.org/specs/gw/UPnP-gw-InternetGatewayDevice-v1-Device.pdf",
+		XMLSpecURL:   "http://upnp.org/specs/gw/UPnP-gw-IGD-TestFiles-20010921.zip",
+		Hacks:        []DCPHackFn{totalBytesHack},
+	},
+	{
+		Name:         "internetgateway2",
+		OfficialName: "Internet Gateway Device v2",
+		DocURL:       "http://upnp.org/specs/gw/UPnP-gw-InternetGatewayDevice-v2-Device.pdf",
+		XMLSpecURL:   "http://upnp.org/specs/gw/UPnP-gw-IGD-Testfiles-20110224.zip",
+		Hacks: []DCPHackFn{
+			func(dcp *DCP) error {
+				missingURN := "urn:schemas-upnp-org:service:WANIPv6FirewallControl:1"
+				if _, ok := dcp.ServiceTypes[missingURN]; ok {
+					return nil
+				}
+				urnParts, err := extractURNParts(missingURN, serviceURNPrefix)
+				if err != nil {
+					return err
+				}
+				dcp.ServiceTypes[missingURN] = urnParts
+				return nil
+			}, totalBytesHack,
+		},
+	},
+	{
+		Name:         "av1",
+		OfficialName: "MediaServer v1 and MediaRenderer v1",
+		DocURL:       "http://upnp.org/specs/av/av1/",
+		XMLSpecURL:   "http://upnp.org/specs/av/UPnP-av-TestFiles-20070927.zip",
+	},
+}
+
+func totalBytesHack(dcp *DCP) error {
+	for _, service := range dcp.Services {
+		if service.URN == "urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1" {
+			variables := service.SCPD.StateVariables
+			for key, variable := range variables {
+				varName := variable.Name
+				if varName == "TotalBytesSent" || varName == "TotalBytesReceived" {
+					// Fix size of total bytes which is by default ui4 or maximum 4 GiB.
+					variable.DataType.Name = "ui8"
+					variables[key] = variable
+				}
+			}
+
+			break
+		}
+	}
+
+	return nil
+}
+
+type DCPHackFn func(*DCP) error

net/upnp/cmd/goupnpdcpgen/typemap.go

@@ -0,0 +1,35 @@
+package main
+
+type conv struct {
+	FuncSuffix string
+	ExtType    string
+}
+
+// typeConvs maps from a SOAP type (e.g "fixed.14.4") to the function name
+// suffix inside the soap module (e.g "Fixed14_4") and the Go type.
+var typeConvs = map[string]conv{
+	"ui1":         {"Ui1", "uint8"},
+	"ui2":         {"Ui2", "uint16"},
+	"ui4":         {"Ui4", "uint32"},
+	"ui8":         {"Ui8", "uint64"},
+	"i1":          {"I1", "int8"},
+	"i2":          {"I2", "int16"},
+	"i4":          {"I4", "int32"},
+	"int":         {"Int", "int64"},
+	"r4":          {"R4", "float32"},
+	"r8":          {"R8", "float64"},
+	"number":      {"R8", "float64"}, // Alias for r8.
+	"fixed.14.4":  {"Fixed14_4", "float64"},
+	"float":       {"R8", "float64"},
+	"char":        {"Char", "rune"},
+	"string":      {"String", "string"},
+	"date":        {"Date", "time.Time"},
+	"dateTime":    {"DateTime", "time.Time"},
+	"dateTime.tz": {"DateTimeTz", "time.Time"},
+	"time":        {"TimeOfDay", "soap.TimeOfDay"},
+	"time.tz":     {"TimeOfDayTz", "soap.TimeOfDay"},
+	"boolean":     {"Boolean", "bool"},
+	"bin.base64":  {"BinBase64", "[]byte"},
+	"bin.hex":     {"BinHex", "[]byte"},
+	"uri":         {"URI", "*url.URL"},
+}

net/upnp/dcps/internetgateway2/.gitignore

@@ -0,0 +1 @@
+*.zip

net/upnp/dcps/internetgateway2/gen.go

@@ -0,0 +1,2 @@
+//go:generate goupnpdcpgen -dcp_name internetgateway2
+package internetgateway2

net/upnp/device.go

@@ -0,0 +1,190 @@
+// This file contains XML structures for communicating with UPnP devices.
+
+package goupnp
+
+import (
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"net/url"
+
+	"tailscale.com/net/upnp/scpd"
+	"tailscale.com/net/upnp/soap"
+)
+
+const (
+	DeviceXMLNamespace = "urn:schemas-upnp-org:device-1-0"
+)
+
+// RootDevice is the device description as described by section 2.3 "Device
+// description" in
+// http://upnp.org/specs/arch/UPnP-arch-DeviceArchitecture-v1.1.pdf
+type RootDevice struct {
+	XMLName     xml.Name    `xml:"root"`
+	SpecVersion SpecVersion `xml:"specVersion"`
+	URLBase     url.URL     `xml:"-"`
+	URLBaseStr  string      `xml:"URLBase"`
+	Device      Device      `xml:"device"`
+}
+
+// SetURLBase sets the URLBase for the RootDevice and its underlying components.
+func (root *RootDevice) SetURLBase(urlBase *url.URL) {
+	root.URLBase = *urlBase
+	root.URLBaseStr = urlBase.String()
+	root.Device.SetURLBase(urlBase)
+}
+
+// SpecVersion is part of a RootDevice, describes the version of the
+// specification that the data adheres to.
+type SpecVersion struct {
+	Major int32 `xml:"major"`
+	Minor int32 `xml:"minor"`
+}
+
+// Device is a UPnP device. It can have child devices.
+type Device struct {
+	DeviceType       string    `xml:"deviceType"`
+	FriendlyName     string    `xml:"friendlyName"`
+	Manufacturer     string    `xml:"manufacturer"`
+	ManufacturerURL  URLField  `xml:"manufacturerURL"`
+	ModelDescription string    `xml:"modelDescription"`
+	ModelName        string    `xml:"modelName"`
+	ModelNumber      string    `xml:"modelNumber"`
+	ModelURL         URLField  `xml:"modelURL"`
+	SerialNumber     string    `xml:"serialNumber"`
+	UDN              string    `xml:"UDN"`
+	UPC              string    `xml:"UPC,omitempty"`
+	Icons            []Icon    `xml:"iconList>icon,omitempty"`
+	Services         []Service `xml:"serviceList>service,omitempty"`
+	Devices          []Device  `xml:"deviceList>device,omitempty"`
+
+	// Extra observed elements:
+	PresentationURL URLField `xml:"presentationURL"`
+}
+
+// VisitDevices calls visitor for the device, and all its descendent devices.
+func (device *Device) VisitDevices(visitor func(*Device)) {
+	visitor(device)
+	for i := range device.Devices {
+		device.Devices[i].VisitDevices(visitor)
+	}
+}
+
+// VisitServices calls visitor for all Services under the device and all its
+// descendent devices.
+func (device *Device) VisitServices(visitor func(*Service)) {
+	device.VisitDevices(func(d *Device) {
+		for i := range d.Services {
+			visitor(&d.Services[i])
+		}
+	})
+}
+
+// FindService finds all (if any) Services under the device and its descendents
+// that have the given ServiceType.
+func (device *Device) FindService(serviceType string) []*Service {
+	var services []*Service
+	device.VisitServices(func(s *Service) {
+		if s.ServiceType == serviceType {
+			services = append(services, s)
+		}
+	})
+	return services
+}
+
+// SetURLBase sets the URLBase for the Device and its underlying components.
+func (device *Device) SetURLBase(urlBase *url.URL) {
+	device.ManufacturerURL.SetURLBase(urlBase)
+	device.ModelURL.SetURLBase(urlBase)
+	device.PresentationURL.SetURLBase(urlBase)
+	for i := range device.Icons {
+		device.Icons[i].SetURLBase(urlBase)
+	}
+	for i := range device.Services {
+		device.Services[i].SetURLBase(urlBase)
+	}
+	for i := range device.Devices {
+		device.Devices[i].SetURLBase(urlBase)
+	}
+}
+
+func (device *Device) String() string {
+	return fmt.Sprintf("Device ID %s : %s (%s)", device.UDN, device.DeviceType, device.FriendlyName)
+}
+
+// Icon is a representative image that a device might include in its
+// description.
+type Icon struct {
+	Mimetype string   `xml:"mimetype"`
+	Width    int32    `xml:"width"`
+	Height   int32    `xml:"height"`
+	Depth    int32    `xml:"depth"`
+	URL      URLField `xml:"url"`
+}
+
+// SetURLBase sets the URLBase for the Icon.
+func (icon *Icon) SetURLBase(url *url.URL) {
+	icon.URL.SetURLBase(url)
+}
+
+// Service is a service provided by a UPnP Device.
+type Service struct {
+	ServiceType string   `xml:"serviceType"`
+	ServiceId   string   `xml:"serviceId"`
+	SCPDURL     URLField `xml:"SCPDURL"`
+	ControlURL  URLField `xml:"controlURL"`
+	EventSubURL URLField `xml:"eventSubURL"`
+}
+
+// SetURLBase sets the URLBase for the Service.
+func (srv *Service) SetURLBase(urlBase *url.URL) {
+	srv.SCPDURL.SetURLBase(urlBase)
+	srv.ControlURL.SetURLBase(urlBase)
+	srv.EventSubURL.SetURLBase(urlBase)
+}
+
+func (srv *Service) String() string {
+	return fmt.Sprintf("Service ID %s : %s", srv.ServiceId, srv.ServiceType)
+}
+
+// RequestSCPD requests the SCPD (soap actions and state variables description)
+// for the service.
+func (srv *Service) RequestSCPD() (*scpd.SCPD, error) {
+	if !srv.SCPDURL.Ok {
+		return nil, errors.New("bad/missing SCPD URL, or no URLBase has been set")
+	}
+	s := new(scpd.SCPD)
+	if err := requestXml(srv.SCPDURL.URL.String(), scpd.SCPDXMLNamespace, s); err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
+// RequestSCDP is for compatibility only, prefer RequestSCPD. This was a
+// misspelling of RequestSCDP.
+func (srv *Service) RequestSCDP() (*scpd.SCPD, error) {
+	return srv.RequestSCPD()
+}
+
+func (srv *Service) NewSOAPClient() *soap.SOAPClient {
+	return soap.NewSOAPClient(srv.ControlURL.URL)
+}
+
+// URLField is a URL that is part of a device description.
+type URLField struct {
+	URL url.URL `xml:"-"`
+	Ok  bool    `xml:"-"`
+	Str string  `xml:",chardata"`
+}
+
+func (uf *URLField) SetURLBase(urlBase *url.URL) {
+	refUrl, err := url.Parse(uf.Str)
+	if err != nil {
+		uf.URL = url.URL{}
+		uf.Ok = false
+		return
+	}
+
+	uf.URL = *urlBase.ResolveReference(refUrl)
+	uf.Ok = true
+}

net/upnp/goupnp.go

@@ -0,0 +1,146 @@
+// goupnp is an implementation of a client for various UPnP services.
+//
+// For most uses, it is recommended to use the code-generated packages under
+// github.com/huin/goupnp/dcps. Example use is shown at
+// http://godoc.org/github.com/huin/goupnp/example
+//
+// A commonly used client is internetgateway1.WANPPPConnection1:
+// http://godoc.org/github.com/huin/goupnp/dcps/internetgateway1#WANPPPConnection1
+//
+// Currently only a couple of schemas have code generated for them from the
+// UPnP example XML specifications. Not all methods will work on these clients,
+// because the generated stubs contain the full set of specified methods from
+// the XML specifications, and the discovered services will likely support a
+// subset of those methods.
+package goupnp
+
+import (
+	"encoding/xml"
+	"fmt"
+	"net/http"
+	"net/url"
+	"time"
+
+	"tailscale.com/net/upnp/ssdp"
+)
+
+// ContextError is an error that wraps an error with some context information.
+type ContextError struct {
+	Context string
+	Err     error
+}
+
+func ctxError(err error, msg string) ContextError {
+	return ContextError{
+		Context: msg,
+		Err:     err,
+	}
+}
+
+func ctxErrorf(err error, msg string, args ...interface{}) ContextError {
+	return ContextError{
+		Context: fmt.Sprintf(msg, args...),
+		Err:     err,
+	}
+}
+
+func (err ContextError) Error() string {
+	return fmt.Sprintf("%s: %v", err.Context, err.Err)
+}
+
+// MaybeRootDevice contains either a RootDevice or an error.
+type MaybeRootDevice struct {
+	// Identifier of the device.
+	USN string
+
+	// Set iff Err == nil.
+	Root *RootDevice
+
+	// The location the device was discovered at. This can be used with
+	// DeviceByURL, assuming the device is still present. A location represents
+	// the discovery of a device, regardless of if there was an error probing it.
+	Location *url.URL
+
+	// Any error encountered probing a discovered device.
+	Err error
+}
+
+// DiscoverDevices attempts to find targets of the given type. This is
+// typically the entry-point for this package. searchTarget is typically a URN
+// in the form "urn:schemas-upnp-org:device:..." or
+// "urn:schemas-upnp-org:service:...". A single error is returned for errors
+// while attempting to send the query. An error or RootDevice is returned for
+// each discovered RootDevice.
+func DiscoverDevices(searchTarget string) ([]MaybeRootDevice, error) {
+	hc, hcCleanup, err := httpuClient()
+	if err != nil {
+		return nil, err
+	}
+	defer hcCleanup()
+	responses, err := ssdp.SSDPRawSearch(hc, string(searchTarget), 2, 3)
+	if err != nil {
+		return nil, err
+	}
+
+	results := make([]MaybeRootDevice, len(responses))
+	for i, response := range responses {
+		maybe := &results[i]
+		maybe.USN = response.Header.Get("USN")
+		loc, err := response.Location()
+		if err != nil {
+			maybe.Err = ContextError{"unexpected bad location from search", err}
+			continue
+		}
+		maybe.Location = loc
+		if root, err := DeviceByURL(loc); err != nil {
+			maybe.Err = err
+		} else {
+			maybe.Root = root
+		}
+	}
+
+	return results, nil
+}
+
+func DeviceByURL(loc *url.URL) (*RootDevice, error) {
+	locStr := loc.String()
+	root := new(RootDevice)
+	if err := requestXml(locStr, DeviceXMLNamespace, root); err != nil {
+		return nil, ContextError{fmt.Sprintf("error requesting root device details from %q", locStr), err}
+	}
+	var urlBaseStr string
+	if root.URLBaseStr != "" {
+		urlBaseStr = root.URLBaseStr
+	} else {
+		urlBaseStr = locStr
+	}
+	urlBase, err := url.Parse(urlBaseStr)
+	if err != nil {
+		return nil, ContextError{fmt.Sprintf("error parsing location URL %q", locStr), err}
+	}
+	root.SetURLBase(urlBase)
+	return root, nil
+}
+
+func requestXml(url string, defaultSpace string, doc interface{}) error {
+	timeout := time.Duration(3 * time.Second)
+	client := http.Client{
+		Timeout: timeout,
+	}
+	resp, err := client.Get(url)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return fmt.Errorf("goupnp: got response status %s from %q",
+			resp.Status, url)
+	}
+
+	decoder := xml.NewDecoder(resp.Body)
+	decoder.DefaultSpace = defaultSpace
+	//decoder.CharsetReader = charset.NewReaderLabel
+
+	return decoder.Decode(doc)
+}

net/upnp/httpu/httpu.go

@@ -0,0 +1,151 @@
+package httpu
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"sync"
+	"time"
+)
+
+// ClientInterface is the general interface provided to perform HTTP-over-UDP
+// requests.
+type ClientInterface interface {
+	// Do performs a request. The timeout is how long to wait for before returning
+	// the responses that were received. An error is only returned for failing to
+	// send the request. Failures in receipt simply do not add to the resulting
+	// responses.
+	Do(
+		req *http.Request,
+		timeout time.Duration,
+		numSends int,
+	) ([]*http.Response, error)
+}
+
+// HTTPUClient is a client for dealing with HTTPU (HTTP over UDP). Its typical
+// function is for HTTPMU, and particularly SSDP.
+type HTTPUClient struct {
+	connLock sync.Mutex // Protects use of conn.
+	conn     net.PacketConn
+}
+
+var _ ClientInterface = &HTTPUClient{}
+
+// NewHTTPUClient creates a new HTTPUClient, opening up a new UDP socket for the
+// purpose.
+func NewHTTPUClient() (*HTTPUClient, error) {
+	conn, err := net.ListenPacket("udp", ":0")
+	if err != nil {
+		return nil, err
+	}
+	return &HTTPUClient{conn: conn}, nil
+}
+
+// NewHTTPUClientAddr creates a new HTTPUClient which will broadcast packets
+// from the specified address, opening up a new UDP socket for the purpose
+func NewHTTPUClientAddr(addr string) (*HTTPUClient, error) {
+	ip := net.ParseIP(addr)
+	if ip == nil {
+		return nil, errors.New("invalid listening address")
+	}
+	conn, err := net.ListenPacket("udp", ip.String()+":0")
+	if err != nil {
+		return nil, err
+	}
+	return &HTTPUClient{conn: conn}, nil
+}
+
+// Close shuts down the client. The client will no longer be useful following
+// this.
+func (httpu *HTTPUClient) Close() error {
+	httpu.connLock.Lock()
+	defer httpu.connLock.Unlock()
+	return httpu.conn.Close()
+}
+
+// Do implements ClientInterface.Do.
+//
+// Note that at present only one concurrent connection will happen per
+// HTTPUClient.
+func (httpu *HTTPUClient) Do(
+	req *http.Request,
+	timeout time.Duration,
+	numSends int,
+) ([]*http.Response, error) {
+	httpu.connLock.Lock()
+	defer httpu.connLock.Unlock()
+
+	// Create the request. This is a subset of what http.Request.Write does
+	// deliberately to avoid creating extra fields which may confuse some
+	// devices.
+	var requestBuf bytes.Buffer
+	method := req.Method
+	if method == "" {
+		method = "GET"
+	}
+	if _, err := fmt.Fprintf(&requestBuf, "%s %s HTTP/1.1\r\n", method, req.URL.RequestURI()); err != nil {
+		return nil, err
+	}
+	if err := req.Header.Write(&requestBuf); err != nil {
+		return nil, err
+	}
+	if _, err := requestBuf.Write([]byte{'\r', '\n'}); err != nil {
+		return nil, err
+	}
+
+	destAddr, err := net.ResolveUDPAddr("udp", req.Host)
+	if err != nil {
+		return nil, err
+	}
+	if err = httpu.conn.SetDeadline(time.Now().Add(timeout)); err != nil {
+		return nil, err
+	}
+
+	// Send request.
+	for i := 0; i < numSends; i++ {
+		if n, err := httpu.conn.WriteTo(requestBuf.Bytes(), destAddr); err != nil {
+			return nil, err
+		} else if n < len(requestBuf.Bytes()) {
+			return nil, fmt.Errorf("httpu: wrote %d bytes rather than full %d in request",
+				n, len(requestBuf.Bytes()))
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+
+	// Await responses until timeout.
+	var responses []*http.Response
+	responseBytes := make([]byte, 2048)
+	for {
+		// 2048 bytes should be sufficient for most networks.
+		n, _, err := httpu.conn.ReadFrom(responseBytes)
+		if err != nil {
+			if err, ok := err.(net.Error); ok {
+				if err.Timeout() {
+					break
+				}
+				if err.Temporary() {
+					// Sleep in case this is a persistent error to avoid pegging CPU until deadline.
+					time.Sleep(10 * time.Millisecond)
+					continue
+				}
+			}
+			return nil, err
+		}
+
+		// Parse response.
+		response, err := http.ReadResponse(bufio.NewReader(bytes.NewBuffer(responseBytes[:n])), req)
+		if err != nil {
+			log.Printf("httpu: error while parsing response: %v", err)
+			continue
+		}
+
+		responses = append(responses, response)
+	}
+
+	// Timeout reached - return discovered responses.
+	return responses, nil
+}

net/upnp/httpu/multiclient.go

@@ -0,0 +1,70 @@
+package httpu
+
+import (
+	"net/http"
+	"time"
+
+	"golang.org/x/sync/errgroup"
+)
+
+// MultiClient dispatches requests out to all the delegated clients.
+type MultiClient struct {
+	// The HTTPU clients to delegate to.
+	delegates []ClientInterface
+}
+
+var _ ClientInterface = &MultiClient{}
+
+// NewMultiClient creates a new MultiClient that delegates to all the given
+// clients.
+func NewMultiClient(delegates []ClientInterface) *MultiClient {
+	return &MultiClient{
+		delegates: delegates,
+	}
+}
+
+// Do implements ClientInterface.Do.
+func (mc *MultiClient) Do(
+	req *http.Request,
+	timeout time.Duration,
+	numSends int,
+) ([]*http.Response, error) {
+	tasks := &errgroup.Group{}
+
+	results := make(chan []*http.Response)
+	tasks.Go(func() error {
+		defer close(results)
+		return mc.sendRequests(results, req, timeout, numSends)
+	})
+
+	var responses []*http.Response
+	tasks.Go(func() error {
+		for rs := range results {
+			responses = append(responses, rs...)
+		}
+		return nil
+	})
+
+	return responses, tasks.Wait()
+}
+
+func (mc *MultiClient) sendRequests(
+	results chan<- []*http.Response,
+	req *http.Request,
+	timeout time.Duration,
+	numSends int,
+) error {
+	tasks := &errgroup.Group{}
+	for _, d := range mc.delegates {
+		d := d // copy for closure
+		tasks.Go(func() error {
+			responses, err := d.Do(req, timeout, numSends)
+			if err != nil {
+				return err
+			}
+			results <- responses
+			return nil
+		})
+	}
+	return tasks.Wait()
+}

net/upnp/httpu/serve.go

@@ -0,0 +1,108 @@
+package httpu
+
+import (
+	"bufio"
+	"bytes"
+	"log"
+	"net"
+	"net/http"
+	"regexp"
+)
+
+const (
+	DefaultMaxMessageBytes = 2048
+)
+
+var (
+	trailingWhitespaceRx = regexp.MustCompile(" +\r\n")
+	crlf                 = []byte("\r\n")
+)
+
+// Handler is the interface by which received HTTPU messages are passed to
+// handling code.
+type Handler interface {
+	// ServeMessage is called for each HTTPU message received. peerAddr contains
+	// the address that the message was received from.
+	ServeMessage(r *http.Request)
+}
+
+// HandlerFunc is a function-to-Handler adapter.
+type HandlerFunc func(r *http.Request)
+
+func (f HandlerFunc) ServeMessage(r *http.Request) {
+	f(r)
+}
+
+// A Server defines parameters for running an HTTPU server.
+type Server struct {
+	Addr            string         // UDP address to listen on
+	Multicast       bool           // Should listen for multicast?
+	Interface       *net.Interface // Network interface to listen on for multicast, nil for default multicast interface
+	Handler         Handler        // handler to invoke
+	MaxMessageBytes int            // maximum number of bytes to read from a packet, DefaultMaxMessageBytes if 0
+}
+
+// ListenAndServe listens on the UDP network address srv.Addr. If srv.Multicast
+// is true, then a multicast UDP listener will be used on srv.Interface (or
+// default interface if nil).
+func (srv *Server) ListenAndServe() error {
+	var err error
+
+	var addr *net.UDPAddr
+	if addr, err = net.ResolveUDPAddr("udp", srv.Addr); err != nil {
+		log.Fatal(err)
+	}
+
+	var conn net.PacketConn
+	if srv.Multicast {
+		if conn, err = net.ListenMulticastUDP("udp", srv.Interface, addr); err != nil {
+			return err
+		}
+	} else {
+		if conn, err = net.ListenUDP("udp", addr); err != nil {
+			return err
+		}
+	}
+
+	return srv.Serve(conn)
+}
+
+// Serve messages received on the given packet listener to the srv.Handler.
+func (srv *Server) Serve(l net.PacketConn) error {
+	maxMessageBytes := DefaultMaxMessageBytes
+	if srv.MaxMessageBytes != 0 {
+		maxMessageBytes = srv.MaxMessageBytes
+	}
+	for {
+		buf := make([]byte, maxMessageBytes)
+		n, peerAddr, err := l.ReadFrom(buf)
+		if err != nil {
+			return err
+		}
+		buf = buf[:n]
+
+		go func(buf []byte, peerAddr net.Addr) {
+			// At least one router's UPnP implementation has added a trailing space
+			// after "HTTP/1.1" - trim it.
+			buf = trailingWhitespaceRx.ReplaceAllLiteral(buf, crlf)
+
+			req, err := http.ReadRequest(bufio.NewReader(bytes.NewBuffer(buf)))
+			if err != nil {
+				log.Printf("httpu: Failed to parse request: %v", err)
+				return
+			}
+			req.RemoteAddr = peerAddr.String()
+			srv.Handler.ServeMessage(req)
+			// No need to call req.Body.Close - underlying reader is bytes.Buffer.
+		}(buf, peerAddr)
+	}
+}
+
+// Serve messages received on the given packet listener to the given handler.
+func Serve(l net.PacketConn, handler Handler) error {
+	srv := Server{
+		Handler:         handler,
+		MaxMessageBytes: DefaultMaxMessageBytes,
+	}
+	return srv.Serve(l)
+}

net/upnp/makefile

@@ -0,0 +1,4 @@
+generate:
+	cd dcps/internetgateway2 && \
+	go run ../../cmd/goupnpdcpgen/. -dcp_name internetgateway2
+

net/upnp/network.go

@@ -0,0 +1,75 @@
+package goupnp
+
+import (
+	"io"
+	"net"
+
+	"tailscale.com/net/upnp/httpu"
+)
+
+// httpuClient creates a HTTPU client that multiplexes to all multicast-capable
+// IPv4 addresses on the host. Returns a function to clean up once the client is
+// no longer required.
+func httpuClient() (httpu.ClientInterface, func(), error) {
+	addrs, err := localIPv4MCastAddrs()
+	if err != nil {
+		return nil, nil, ctxError(err, "requesting host IPv4 addresses")
+	}
+
+	closers := make([]io.Closer, 0, len(addrs))
+	delegates := make([]httpu.ClientInterface, 0, len(addrs))
+	for _, addr := range addrs {
+		c, err := httpu.NewHTTPUClientAddr(addr)
+		if err != nil {
+			return nil, nil, ctxErrorf(err,
+				"creating HTTPU client for address %s", addr)
+		}
+		closers = append(closers, c)
+		delegates = append(delegates, c)
+	}
+
+	closer := func() {
+		for _, c := range closers {
+			c.Close()
+		}
+	}
+
+	return httpu.NewMultiClient(delegates), closer, nil
+}
+
+// localIPv4MCastAddrs returns the set of IPv4 addresses on multicast-able
+// network interfaces.
+func localIPv4MCastAddrs() ([]string, error) {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return nil, ctxError(err, "requesting host interfaces")
+	}
+
+	// Find the set of addresses to listen on.
+	var addrs []string
+	for _, iface := range ifaces {
+		if iface.Flags&net.FlagMulticast == 0 || iface.Flags&net.FlagLoopback != 0 || iface.Flags&net.FlagUp == 0 {
+			// Does not support multicast or is a loopback address.
+			continue
+		}
+		ifaceAddrs, err := iface.Addrs()
+		if err != nil {
+			return nil, ctxErrorf(err,
+				"finding addresses on interface %s", iface.Name)
+		}
+		for _, netAddr := range ifaceAddrs {
+			addr, ok := netAddr.(*net.IPNet)
+			if !ok {
+				// Not an IPNet address.
+				continue
+			}
+			if addr.IP.To4() == nil {
+				// Not IPv4.
+				continue
+			}
+			addrs = append(addrs, addr.IP.String())
+		}
+	}
+
+	return addrs, nil
+}

net/upnp/scpd/scpd.go

@@ -0,0 +1,167 @@
+package scpd
+
+import (
+	"encoding/xml"
+	"strings"
+)
+
+const (
+	SCPDXMLNamespace = "urn:schemas-upnp-org:service-1-0"
+)
+
+func cleanWhitespace(s *string) {
+	*s = strings.TrimSpace(*s)
+}
+
+// SCPD is the service description as described by section 2.5 "Service
+// description" in
+// http://upnp.org/specs/arch/UPnP-arch-DeviceArchitecture-v1.1.pdf
+type SCPD struct {
+	XMLName        xml.Name        `xml:"scpd"`
+	ConfigId       string          `xml:"configId,attr"`
+	SpecVersion    SpecVersion     `xml:"specVersion"`
+	Actions        []Action        `xml:"actionList>action"`
+	StateVariables []StateVariable `xml:"serviceStateTable>stateVariable"`
+}
+
+// Clean attempts to remove stray whitespace etc. in the structure. It seems
+// unfortunately common for stray whitespace to be present in SCPD documents,
+// this method attempts to make it easy to clean them out.
+func (scpd *SCPD) Clean() {
+	cleanWhitespace(&scpd.ConfigId)
+	for i := range scpd.Actions {
+		scpd.Actions[i].clean()
+	}
+	for i := range scpd.StateVariables {
+		scpd.StateVariables[i].clean()
+	}
+}
+
+func (scpd *SCPD) GetStateVariable(variable string) *StateVariable {
+	for i := range scpd.StateVariables {
+		v := &scpd.StateVariables[i]
+		if v.Name == variable {
+			return v
+		}
+	}
+	return nil
+}
+
+func (scpd *SCPD) GetAction(action string) *Action {
+	for i := range scpd.Actions {
+		a := &scpd.Actions[i]
+		if a.Name == action {
+			return a
+		}
+	}
+	return nil
+}
+
+// SpecVersion is part of a SCPD document, describes the version of the
+// specification that the data adheres to.
+type SpecVersion struct {
+	Major int32 `xml:"major"`
+	Minor int32 `xml:"minor"`
+}
+
+type Action struct {
+	Name      string     `xml:"name"`
+	Arguments []Argument `xml:"argumentList>argument"`
+}
+
+func (action *Action) clean() {
+	cleanWhitespace(&action.Name)
+	for i := range action.Arguments {
+		action.Arguments[i].clean()
+	}
+}
+
+func (action *Action) InputArguments() []*Argument {
+	var result []*Argument
+	for i := range action.Arguments {
+		arg := &action.Arguments[i]
+		if arg.IsInput() {
+			result = append(result, arg)
+		}
+	}
+	return result
+}
+
+func (action *Action) OutputArguments() []*Argument {
+	var result []*Argument
+	for i := range action.Arguments {
+		arg := &action.Arguments[i]
+		if arg.IsOutput() {
+			result = append(result, arg)
+		}
+	}
+	return result
+}
+
+type Argument struct {
+	Name                 string `xml:"name"`
+	Direction            string `xml:"direction"`            // in|out
+	RelatedStateVariable string `xml:"relatedStateVariable"` // ?
+	Retval               string `xml:"retval"`               // ?
+}
+
+func (arg *Argument) clean() {
+	cleanWhitespace(&arg.Name)
+	cleanWhitespace(&arg.Direction)
+	cleanWhitespace(&arg.RelatedStateVariable)
+	cleanWhitespace(&arg.Retval)
+}
+
+func (arg *Argument) IsInput() bool {
+	return arg.Direction == "in"
+}
+
+func (arg *Argument) IsOutput() bool {
+	return arg.Direction == "out"
+}
+
+type StateVariable struct {
+	Name              string             `xml:"name"`
+	SendEvents        string             `xml:"sendEvents,attr"` // yes|no
+	Multicast         string             `xml:"multicast,attr"`  // yes|no
+	DataType          DataType           `xml:"dataType"`
+	DefaultValue      string             `xml:"defaultValue"`
+	AllowedValueRange *AllowedValueRange `xml:"allowedValueRange"`
+	AllowedValues     []string           `xml:"allowedValueList>allowedValue"`
+}
+
+func (v *StateVariable) clean() {
+	cleanWhitespace(&v.Name)
+	cleanWhitespace(&v.SendEvents)
+	cleanWhitespace(&v.Multicast)
+	v.DataType.clean()
+	cleanWhitespace(&v.DefaultValue)
+	if v.AllowedValueRange != nil {
+		v.AllowedValueRange.clean()
+	}
+	for i := range v.AllowedValues {
+		cleanWhitespace(&v.AllowedValues[i])
+	}
+}
+
+type AllowedValueRange struct {
+	Minimum string `xml:"minimum"`
+	Maximum string `xml:"maximum"`
+	Step    string `xml:"step"`
+}
+
+func (r *AllowedValueRange) clean() {
+	cleanWhitespace(&r.Minimum)
+	cleanWhitespace(&r.Maximum)
+	cleanWhitespace(&r.Step)
+}
+
+type DataType struct {
+	Name string `xml:",chardata"`
+	Type string `xml:"type,attr"`
+}
+
+func (dt *DataType) clean() {
+	cleanWhitespace(&dt.Name)
+	cleanWhitespace(&dt.Type)
+}

net/upnp/service_client.go

@@ -0,0 +1,88 @@
+package goupnp
+
+import (
+	"fmt"
+	"net/url"
+
+	"tailscale.com/net/upnp/soap"
+)
+
+// ServiceClient is a SOAP client, root device and the service for the SOAP
+// client rolled into one value. The root device, location, and service are
+// intended to be informational. Location can be used to later recreate a
+// ServiceClient with NewServiceClientByURL if the service is still present;
+// bypassing the discovery process.
+type ServiceClient struct {
+	SOAPClient *soap.SOAPClient
+	RootDevice *RootDevice
+	Location   *url.URL
+	Service    *Service
+}
+
+// NewServiceClients discovers services, and returns clients for them. err will
+// report any error with the discovery process (blocking any device/service
+// discovery), errors reports errors on a per-root-device basis.
+func NewServiceClients(searchTarget string) (clients []ServiceClient, errors []error, err error) {
+	var maybeRootDevices []MaybeRootDevice
+	if maybeRootDevices, err = DiscoverDevices(searchTarget); err != nil {
+		return
+	}
+
+	clients = make([]ServiceClient, 0, len(maybeRootDevices))
+
+	for _, maybeRootDevice := range maybeRootDevices {
+		if maybeRootDevice.Err != nil {
+			errors = append(errors, maybeRootDevice.Err)
+			continue
+		}
+
+		deviceClients, err := NewServiceClientsFromRootDevice(maybeRootDevice.Root, maybeRootDevice.Location, searchTarget)
+		if err != nil {
+			errors = append(errors, err)
+			continue
+		}
+		clients = append(clients, deviceClients...)
+	}
+
+	return
+}
+
+// NewServiceClientsByURL creates client(s) for the given service URN, for a
+// root device at the given URL.
+func NewServiceClientsByURL(loc *url.URL, searchTarget string) ([]ServiceClient, error) {
+	rootDevice, err := DeviceByURL(loc)
+	if err != nil {
+		return nil, err
+	}
+	return NewServiceClientsFromRootDevice(rootDevice, loc, searchTarget)
+}
+
+// NewServiceClientsFromDevice creates client(s) for the given service URN, in
+// 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) {
+	device := &rootDevice.Device
+	srvs := device.FindService(searchTarget)
+	if len(srvs) == 0 {
+		return nil, fmt.Errorf("goupnp: service %q not found within device %q (UDN=%q)",
+			searchTarget, device.FriendlyName, device.UDN)
+	}
+
+	clients := make([]ServiceClient, 0, len(srvs))
+	for _, srv := range srvs {
+		clients = append(clients, ServiceClient{
+			SOAPClient: srv.NewSOAPClient(),
+			RootDevice: rootDevice,
+			Location:   loc,
+			Service:    srv,
+		})
+	}
+	return clients, nil
+}
+
+// GetServiceClient returns the ServiceClient itself. This is provided so that the
+// service client attributes can be accessed via an interface method on a
+// wrapping type.
+func (client *ServiceClient) GetServiceClient() *ServiceClient {
+	return client
+}

net/upnp/soap/soap.go

@@ -0,0 +1,200 @@
+// Definition for the SOAP structure required for UPnP's SOAP usage.
+
+package soap
+
+import (
+	"bytes"
+	"context"
+	"encoding/xml"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"reflect"
+	"regexp"
+)
+
+const (
+	soapEncodingStyle = "http://schemas.xmlsoap.org/soap/encoding/"
+	soapPrefix        = xml.Header + `<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"><s:Body>`
+	soapSuffix        = `</s:Body></s:Envelope>`
+)
+
+type SOAPClient struct {
+	EndpointURL url.URL
+	HTTPClient  http.Client
+}
+
+func NewSOAPClient(endpointURL url.URL) *SOAPClient {
+	return &SOAPClient{
+		EndpointURL: endpointURL,
+	}
+}
+
+// PerformSOAPAction makes a SOAP request, with the given action.
+// inAction and outAction must both be pointers to structs with string fields
+// only.
+func (client *SOAPClient) PerformAction(ctx context.Context, actionNamespace, actionName string, inAction interface{}, outAction interface{}) error {
+	requestBytes, err := encodeRequestAction(actionNamespace, actionName, inAction)
+	if err != nil {
+		return err
+	}
+
+	req := &http.Request{
+		Method: "POST",
+		URL:    &client.EndpointURL,
+		Header: http.Header{
+			"SOAPACTION":   []string{`"` + actionNamespace + "#" + actionName + `"`},
+			"CONTENT-TYPE": []string{"text/xml; charset=\"utf-8\""},
+		},
+		Body: ioutil.NopCloser(bytes.NewBuffer(requestBytes)),
+		// Set ContentLength to avoid chunked encoding - some servers might not support it.
+		ContentLength: int64(len(requestBytes)),
+	}
+
+	response, err := client.HTTPClient.Do(req.WithContext(ctx))
+	if err != nil {
+		return fmt.Errorf("goupnp: error performing SOAP HTTP request: %v", err)
+	}
+	defer response.Body.Close()
+	if response.StatusCode != 200 && response.ContentLength == 0 {
+		return fmt.Errorf("goupnp: SOAP request got HTTP %s", response.Status)
+	}
+
+	responseEnv := newSOAPEnvelope()
+	decoder := xml.NewDecoder(response.Body)
+	if err := decoder.Decode(responseEnv); err != nil {
+		return fmt.Errorf("goupnp: error decoding response body: %v", err)
+	}
+
+	if responseEnv.Body.Fault != nil {
+		return responseEnv.Body.Fault
+	} else if response.StatusCode != 200 {
+		return fmt.Errorf("goupnp: SOAP request got HTTP %s", response.Status)
+	}
+
+	if outAction != nil {
+		if err := xml.Unmarshal(responseEnv.Body.RawAction, outAction); err != nil {
+			return fmt.Errorf("goupnp: error unmarshalling out action: %v, %v", err, responseEnv.Body.RawAction)
+		}
+	}
+
+	return nil
+}
+
+// newSOAPAction creates a soapEnvelope with the given action and arguments.
+func newSOAPEnvelope() *soapEnvelope {
+	return &soapEnvelope{
+		EncodingStyle: soapEncodingStyle,
+	}
+}
+
+// encodeRequestAction is a hacky way to create an encoded SOAP envelope
+// containing the given action. Experiments with one router have shown that it
+// 500s for requests where the outer default xmlns is set to the SOAP
+// namespace, and then reassigning the default namespace within that to the
+// service namespace. Hand-coding the outer XML to work-around this.
+func encodeRequestAction(actionNamespace, actionName string, inAction interface{}) ([]byte, error) {
+	requestBuf := new(bytes.Buffer)
+	requestBuf.WriteString(soapPrefix)
+	requestBuf.WriteString(`<u:`)
+	xml.EscapeText(requestBuf, []byte(actionName))
+	requestBuf.WriteString(` xmlns:u="`)
+	xml.EscapeText(requestBuf, []byte(actionNamespace))
+	requestBuf.WriteString(`">`)
+	if inAction != nil {
+		if err := encodeRequestArgs(requestBuf, inAction); err != nil {
+			return nil, err
+		}
+	}
+	requestBuf.WriteString(`</u:`)
+	xml.EscapeText(requestBuf, []byte(actionName))
+	requestBuf.WriteString(`>`)
+	requestBuf.WriteString(soapSuffix)
+	return requestBuf.Bytes(), nil
+}
+
+func encodeRequestArgs(w *bytes.Buffer, inAction interface{}) error {
+	in := reflect.Indirect(reflect.ValueOf(inAction))
+	if in.Kind() != reflect.Struct {
+		return fmt.Errorf("goupnp: SOAP inAction is not a struct but of type %v", in.Type())
+	}
+	enc := xml.NewEncoder(w)
+	nFields := in.NumField()
+	inType := in.Type()
+	for i := 0; i < nFields; i++ {
+		field := inType.Field(i)
+		argName := field.Name
+		if nameOverride := field.Tag.Get("soap"); nameOverride != "" {
+			argName = nameOverride
+		}
+		value := in.Field(i)
+		if value.Kind() != reflect.String {
+			return fmt.Errorf("goupnp: SOAP arg %q is not of type string, but of type %v", argName, value.Type())
+		}
+		elem := xml.StartElement{Name: xml.Name{Space: "", Local: argName}, Attr: nil}
+		if err := enc.EncodeToken(elem); err != nil {
+			return fmt.Errorf("goupnp: error encoding start element for SOAP arg %q: %v", argName, err)
+		}
+		if err := enc.Flush(); err != nil {
+			return fmt.Errorf("goupnp: error flushing start element for SOAP arg %q: %v", argName, err)
+		}
+		if _, err := w.Write([]byte(escapeXMLText(value.Interface().(string)))); err != nil {
+			return fmt.Errorf("goupnp: error writing value for SOAP arg %q: %v", argName, err)
+		}
+		if err := enc.EncodeToken(elem.End()); err != nil {
+			return fmt.Errorf("goupnp: error encoding end element for SOAP arg %q: %v", argName, err)
+		}
+	}
+	enc.Flush()
+	return nil
+}
+
+var xmlCharRx = regexp.MustCompile("[<>&]")
+
+// escapeXMLText is used by generated code to escape text in XML, but only
+// escaping the characters `<`, `>`, and `&`.
+//
+// This is provided in order to work around SOAP server implementations that
+// fail to decode XML correctly, specifically failing to decode `"`, `'`. Note
+// that this can only be safely used for injecting into XML text, but not into
+// attributes or other contexts.
+func escapeXMLText(s string) string {
+	return xmlCharRx.ReplaceAllStringFunc(s, replaceEntity)
+}
+
+func replaceEntity(s string) string {
+	switch s {
+	case "<":
+		return "&lt;"
+	case ">":
+		return "&gt;"
+	case "&":
+		return "&amp;"
+	}
+	return s
+}
+
+type soapEnvelope struct {
+	XMLName       xml.Name `xml:"http://schemas.xmlsoap.org/soap/envelope/ Envelope"`
+	EncodingStyle string   `xml:"http://schemas.xmlsoap.org/soap/envelope/ encodingStyle,attr"`
+	Body          soapBody `xml:"http://schemas.xmlsoap.org/soap/envelope/ Body"`
+}
+
+type soapBody struct {
+	Fault     *SOAPFaultError `xml:"Fault"`
+	RawAction []byte          `xml:",innerxml"`
+}
+
+// SOAPFaultError implements error, and contains SOAP fault information.
+type SOAPFaultError struct {
+	FaultCode   string `xml:"faultCode"`
+	FaultString string `xml:"faultString"`
+	Detail      struct {
+		Raw []byte `xml:",innerxml"`
+	} `xml:"detail"`
+}
+
+func (err *SOAPFaultError) Error() string {
+	return fmt.Sprintf("SOAP fault: %s", err.FaultString)
+}

net/upnp/soap/soap_test.go

@@ -0,0 +1,111 @@
+package soap
+
+import (
+	"bytes"
+	"context"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"reflect"
+	"testing"
+)
+
+type capturingRoundTripper struct {
+	err         error
+	resp        *http.Response
+	capturedReq *http.Request
+}
+
+func (rt *capturingRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	rt.capturedReq = req
+	return rt.resp, rt.err
+}
+
+func TestActionInputs(t *testing.T) {
+	t.Parallel()
+	url, err := url.Parse("http://example.com/soap")
+	if err != nil {
+		t.Fatal(err)
+	}
+	rt := &capturingRoundTripper{
+		err: nil,
+		resp: &http.Response{
+			StatusCode: 200,
+			Body: ioutil.NopCloser(bytes.NewBufferString(`
+				<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
+					<s:Body>
+						<u:myactionResponse xmlns:u="mynamespace">
+							<A>valueA</A>
+							<B>valueB</B>
+						</u:myactionResponse>
+					</s:Body>
+				</s:Envelope>
+			`)),
+		},
+	}
+	client := SOAPClient{
+		EndpointURL: *url,
+		HTTPClient: http.Client{
+			Transport: rt,
+		},
+	}
+
+	type In struct {
+		Foo string
+		Bar string `soap:"bar"`
+		Baz string
+	}
+	type Out struct {
+		A string
+		B string
+	}
+	in := In{"foo", "bar", "quoted=\"baz\""}
+	gotOut := Out{}
+	err = client.PerformAction(context.Background(), "mynamespace", "myaction", &in, &gotOut)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	wantBody := (soapPrefix +
+		`<u:myaction xmlns:u="mynamespace">` +
+		`<Foo>foo</Foo>` +
+		`<bar>bar</bar>` +
+		`<Baz>quoted="baz"</Baz>` +
+		`</u:myaction>` +
+		soapSuffix)
+	body, err := ioutil.ReadAll(rt.capturedReq.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+	gotBody := string(body)
+	if wantBody != gotBody {
+		t.Errorf("Bad request body\nwant: %q\n got: %q", wantBody, gotBody)
+	}
+
+	wantOut := Out{"valueA", "valueB"}
+	if !reflect.DeepEqual(wantOut, gotOut) {
+		t.Errorf("Bad output\nwant: %+v\n got: %+v", wantOut, gotOut)
+	}
+}
+
+func TestEscapeXMLText(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		input string
+		want  string
+	}{
+		{"", ""},
+		{"abc123", "abc123"},
+		{"<foo>&", "&lt;foo&gt;&amp;"},
+		{"\"foo'", "\"foo'"},
+	}
+	for _, test := range tests {
+		test := test
+		t.Run(test.input, func(t *testing.T) {
+			got := escapeXMLText(test.input)
+			if got != test.want {
+				t.Errorf("want %q, got %q", test.want, got)
+			}
+		})
+	}
+}

net/upnp/soap/types.go

@@ -0,0 +1,526 @@
+package soap
+
+import (
+	"encoding/base64"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"net/url"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+	"unicode/utf8"
+)
+
+var (
+	// localLoc acts like time.Local for this package, but is faked out by the
+	// unit tests to ensure that things stay constant (especially when running
+	// this test in a place where local time is UTC which might mask bugs).
+	localLoc = time.Local
+)
+
+func MarshalUi1(v uint8) (string, error) {
+	return strconv.FormatUint(uint64(v), 10), nil
+}
+
+func UnmarshalUi1(s string) (uint8, error) {
+	v, err := strconv.ParseUint(s, 10, 8)
+	return uint8(v), err
+}
+
+func MarshalUi2(v uint16) (string, error) {
+	return strconv.FormatUint(uint64(v), 10), nil
+}
+
+func UnmarshalUi2(s string) (uint16, error) {
+	v, err := strconv.ParseUint(s, 10, 16)
+	return uint16(v), err
+}
+
+func MarshalUi4(v uint32) (string, error) {
+	return strconv.FormatUint(uint64(v), 10), nil
+}
+
+func UnmarshalUi4(s string) (uint32, error) {
+	v, err := strconv.ParseUint(s, 10, 32)
+	return uint32(v), err
+}
+
+func MarshalUi8(v uint64) (string, error) {
+	return strconv.FormatUint(v, 10), nil
+}
+
+func UnmarshalUi8(s string) (uint64, error) {
+	v, err := strconv.ParseUint(s, 10, 64)
+	return uint64(v), err
+}
+
+func MarshalI1(v int8) (string, error) {
+	return strconv.FormatInt(int64(v), 10), nil
+}
+
+func UnmarshalI1(s string) (int8, error) {
+	v, err := strconv.ParseInt(s, 10, 8)
+	return int8(v), err
+}
+
+func MarshalI2(v int16) (string, error) {
+	return strconv.FormatInt(int64(v), 10), nil
+}
+
+func UnmarshalI2(s string) (int16, error) {
+	v, err := strconv.ParseInt(s, 10, 16)
+	return int16(v), err
+}
+
+func MarshalI4(v int32) (string, error) {
+	return strconv.FormatInt(int64(v), 10), nil
+}
+
+func UnmarshalI4(s string) (int32, error) {
+	v, err := strconv.ParseInt(s, 10, 32)
+	return int32(v), err
+}
+
+func MarshalInt(v int64) (string, error) {
+	return strconv.FormatInt(v, 10), nil
+}
+
+func UnmarshalInt(s string) (int64, error) {
+	return strconv.ParseInt(s, 10, 64)
+}
+
+func MarshalR4(v float32) (string, error) {
+	return strconv.FormatFloat(float64(v), 'G', -1, 32), nil
+}
+
+func UnmarshalR4(s string) (float32, error) {
+	v, err := strconv.ParseFloat(s, 32)
+	return float32(v), err
+}
+
+func MarshalR8(v float64) (string, error) {
+	return strconv.FormatFloat(v, 'G', -1, 64), nil
+}
+
+func UnmarshalR8(s string) (float64, error) {
+	v, err := strconv.ParseFloat(s, 64)
+	return float64(v), err
+}
+
+// MarshalFixed14_4 marshals float64 to SOAP "fixed.14.4" type.
+func MarshalFixed14_4(v float64) (string, error) {
+	if v >= 1e14 || v <= -1e14 {
+		return "", fmt.Errorf("soap fixed14.4: value %v out of bounds", v)
+	}
+	return strconv.FormatFloat(v, 'f', 4, 64), nil
+}
+
+// UnmarshalFixed14_4 unmarshals float64 from SOAP "fixed.14.4" type.
+func UnmarshalFixed14_4(s string) (float64, error) {
+	v, err := strconv.ParseFloat(s, 64)
+	if err != nil {
+		return 0, err
+	}
+	if v >= 1e14 || v <= -1e14 {
+		return 0, fmt.Errorf("soap fixed14.4: value %q out of bounds", s)
+	}
+	return v, nil
+}
+
+// MarshalChar marshals rune to SOAP "char" type.
+func MarshalChar(v rune) (string, error) {
+	if v == 0 {
+		return "", errors.New("soap char: rune 0 is not allowed")
+	}
+	return string(v), nil
+}
+
+// UnmarshalChar unmarshals rune from SOAP "char" type.
+func UnmarshalChar(s string) (rune, error) {
+	if len(s) == 0 {
+		return 0, errors.New("soap char: got empty string")
+	}
+	r, n := utf8.DecodeRune([]byte(s))
+	if n != len(s) {
+		return 0, fmt.Errorf("soap char: value %q is not a single rune", s)
+	}
+	return r, nil
+}
+
+func MarshalString(v string) (string, error) {
+	return v, nil
+}
+
+func UnmarshalString(v string) (string, error) {
+	return v, nil
+}
+
+func parseInt(s string, err *error) int {
+	v, parseErr := strconv.ParseInt(s, 10, 64)
+	if parseErr != nil {
+		*err = parseErr
+	}
+	return int(v)
+}
+
+var dateRegexps = []*regexp.Regexp{
+	// yyyy[-mm[-dd]]
+	regexp.MustCompile(`^(\d{4})(?:-(\d{2})(?:-(\d{2}))?)?$`),
+	// yyyy[mm[dd]]
+	regexp.MustCompile(`^(\d{4})(?:(\d{2})(?:(\d{2}))?)?$`),
+}
+
+func parseDateParts(s string) (year, month, day int, err error) {
+	var parts []string
+	for _, re := range dateRegexps {
+		parts = re.FindStringSubmatch(s)
+		if parts != nil {
+			break
+		}
+	}
+	if parts == nil {
+		err = fmt.Errorf("soap date: value %q is not in a recognized ISO8601 date format", s)
+		return
+	}
+
+	year = parseInt(parts[1], &err)
+	month = 1
+	day = 1
+	if len(parts[2]) != 0 {
+		month = parseInt(parts[2], &err)
+		if len(parts[3]) != 0 {
+			day = parseInt(parts[3], &err)
+		}
+	}
+
+	if err != nil {
+		err = fmt.Errorf("soap date: %q: %v", s, err)
+	}
+
+	return
+}
+
+var timeRegexps = []*regexp.Regexp{
+	// hh[:mm[:ss]]
+	regexp.MustCompile(`^(\d{2})(?::(\d{2})(?::(\d{2}))?)?$`),
+	// hh[mm[ss]]
+	regexp.MustCompile(`^(\d{2})(?:(\d{2})(?:(\d{2}))?)?$`),
+}
+
+func parseTimeParts(s string) (hour, minute, second int, err error) {
+	var parts []string
+	for _, re := range timeRegexps {
+		parts = re.FindStringSubmatch(s)
+		if parts != nil {
+			break
+		}
+	}
+	if parts == nil {
+		err = fmt.Errorf("soap time: value %q is not in ISO8601 time format", s)
+		return
+	}
+
+	hour = parseInt(parts[1], &err)
+	if len(parts[2]) != 0 {
+		minute = parseInt(parts[2], &err)
+		if len(parts[3]) != 0 {
+			second = parseInt(parts[3], &err)
+		}
+	}
+
+	if err != nil {
+		err = fmt.Errorf("soap time: %q: %v", s, err)
+	}
+
+	return
+}
+
+// (+|-)hh[[:]mm]
+var timezoneRegexp = regexp.MustCompile(`^([+-])(\d{2})(?::?(\d{2}))?$`)
+
+func parseTimezone(s string) (offset int, err error) {
+	if s == "Z" {
+		return 0, nil
+	}
+	parts := timezoneRegexp.FindStringSubmatch(s)
+	if parts == nil {
+		err = fmt.Errorf("soap timezone: value %q is not in ISO8601 timezone format", s)
+		return
+	}
+
+	offset = parseInt(parts[2], &err) * 3600
+	if len(parts[3]) != 0 {
+		offset += parseInt(parts[3], &err) * 60
+	}
+	if parts[1] == "-" {
+		offset = -offset
+	}
+
+	if err != nil {
+		err = fmt.Errorf("soap timezone: %q: %v", s, err)
+	}
+
+	return
+}
+
+var completeDateTimeZoneRegexp = regexp.MustCompile(`^([^T]+)(?:T([^-+Z]+)(.+)?)?$`)
+
+// splitCompleteDateTimeZone splits date, time and timezone apart from an
+// ISO8601 string. It does not ensure that the contents of each part are
+// correct, it merely splits on certain delimiters.
+// e.g "2010-09-08T12:15:10+0700" => "2010-09-08", "12:15:10", "+0700".
+// Timezone can only be present if time is also present.
+func splitCompleteDateTimeZone(s string) (dateStr, timeStr, zoneStr string, err error) {
+	parts := completeDateTimeZoneRegexp.FindStringSubmatch(s)
+	if parts == nil {
+		err = fmt.Errorf("soap date/time/zone: value %q is not in ISO8601 datetime format", s)
+		return
+	}
+	dateStr = parts[1]
+	timeStr = parts[2]
+	zoneStr = parts[3]
+	return
+}
+
+// MarshalDate marshals time.Time to SOAP "date" type. Note that this converts
+// to local time, and discards the time-of-day components.
+func MarshalDate(v time.Time) (string, error) {
+	return v.In(localLoc).Format("2006-01-02"), nil
+}
+
+// UnmarshalDate unmarshals time.Time from SOAP "date" type. This outputs the
+// date as midnight in the local time zone.
+func UnmarshalDate(s string) (time.Time, error) {
+	year, month, day, err := parseDateParts(s)
+	if err != nil {
+		return time.Time{}, err
+	}
+	return time.Date(year, time.Month(month), day, 0, 0, 0, 0, localLoc), nil
+}
+
+// TimeOfDay is used in cases where SOAP "time" or "time.tz" is used.
+type TimeOfDay struct {
+	// Duration of time since midnight.
+	FromMidnight time.Duration
+
+	// Set to true if Offset is specified. If false, then the timezone is
+	// unspecified (and by ISO8601 - implies some "local" time).
+	HasOffset bool
+
+	// Offset is non-zero only if time.tz is used. It is otherwise ignored. If
+	// non-zero, then it is regarded as a UTC offset in seconds. Note that the
+	// sub-minutes is ignored by the marshal function.
+	Offset int
+}
+
+// MarshalTimeOfDay marshals TimeOfDay to the "time" type.
+func MarshalTimeOfDay(v TimeOfDay) (string, error) {
+	d := int64(v.FromMidnight / time.Second)
+	hour := d / 3600
+	d = d % 3600
+	minute := d / 60
+	second := d % 60
+
+	return fmt.Sprintf("%02d:%02d:%02d", hour, minute, second), nil
+}
+
+// UnmarshalTimeOfDay unmarshals TimeOfDay from the "time" type.
+func UnmarshalTimeOfDay(s string) (TimeOfDay, error) {
+	t, err := UnmarshalTimeOfDayTz(s)
+	if err != nil {
+		return TimeOfDay{}, err
+	} else if t.HasOffset {
+		return TimeOfDay{}, fmt.Errorf("soap time: value %q contains unexpected timezone", s)
+	}
+	return t, nil
+}
+
+// MarshalTimeOfDayTz marshals TimeOfDay to the "time.tz" type.
+func MarshalTimeOfDayTz(v TimeOfDay) (string, error) {
+	d := int64(v.FromMidnight / time.Second)
+	hour := d / 3600
+	d = d % 3600
+	minute := d / 60
+	second := d % 60
+
+	tz := ""
+	if v.HasOffset {
+		if v.Offset == 0 {
+			tz = "Z"
+		} else {
+			offsetMins := v.Offset / 60
+			sign := '+'
+			if offsetMins < 1 {
+				offsetMins = -offsetMins
+				sign = '-'
+			}
+			tz = fmt.Sprintf("%c%02d:%02d", sign, offsetMins/60, offsetMins%60)
+		}
+	}
+
+	return fmt.Sprintf("%02d:%02d:%02d%s", hour, minute, second, tz), nil
+}
+
+// UnmarshalTimeOfDayTz unmarshals TimeOfDay from the "time.tz" type.
+func UnmarshalTimeOfDayTz(s string) (tod TimeOfDay, err error) {
+	zoneIndex := strings.IndexAny(s, "Z+-")
+	var timePart string
+	var hasOffset bool
+	var offset int
+	if zoneIndex == -1 {
+		hasOffset = false
+		timePart = s
+	} else {
+		hasOffset = true
+		timePart = s[:zoneIndex]
+		if offset, err = parseTimezone(s[zoneIndex:]); err != nil {
+			return
+		}
+	}
+
+	hour, minute, second, err := parseTimeParts(timePart)
+	if err != nil {
+		return
+	}
+
+	fromMidnight := time.Duration(hour*3600+minute*60+second) * time.Second
+
+	// ISO8601 special case - values up to 24:00:00 are allowed, so using
+	// strictly greater-than for the maximum value.
+	if fromMidnight > 24*time.Hour || minute >= 60 || second >= 60 {
+		return TimeOfDay{}, fmt.Errorf("soap time.tz: value %q has value(s) out of range", s)
+	}
+
+	return TimeOfDay{
+		FromMidnight: time.Duration(hour*3600+minute*60+second) * time.Second,
+		HasOffset:    hasOffset,
+		Offset:       offset,
+	}, nil
+}
+
+// MarshalDateTime marshals time.Time to SOAP "dateTime" type. Note that this
+// converts to local time.
+func MarshalDateTime(v time.Time) (string, error) {
+	return v.In(localLoc).Format("2006-01-02T15:04:05"), nil
+}
+
+// UnmarshalDateTime unmarshals time.Time from the SOAP "dateTime" type. This
+// returns a value in the local timezone.
+func UnmarshalDateTime(s string) (result time.Time, err error) {
+	dateStr, timeStr, zoneStr, err := splitCompleteDateTimeZone(s)
+	if err != nil {
+		return
+	}
+
+	if len(zoneStr) != 0 {
+		err = fmt.Errorf("soap datetime: unexpected timezone in %q", s)
+		return
+	}
+
+	year, month, day, err := parseDateParts(dateStr)
+	if err != nil {
+		return
+	}
+
+	var hour, minute, second int
+	if len(timeStr) != 0 {
+		hour, minute, second, err = parseTimeParts(timeStr)
+		if err != nil {
+			return
+		}
+	}
+
+	result = time.Date(year, time.Month(month), day, hour, minute, second, 0, localLoc)
+	return
+}
+
+// MarshalDateTimeTz marshals time.Time to SOAP "dateTime.tz" type.
+func MarshalDateTimeTz(v time.Time) (string, error) {
+	return v.Format("2006-01-02T15:04:05-07:00"), nil
+}
+
+// UnmarshalDateTimeTz unmarshals time.Time from the SOAP "dateTime.tz" type.
+// This returns a value in the local timezone when the timezone is unspecified.
+func UnmarshalDateTimeTz(s string) (result time.Time, err error) {
+	dateStr, timeStr, zoneStr, err := splitCompleteDateTimeZone(s)
+	if err != nil {
+		return
+	}
+
+	year, month, day, err := parseDateParts(dateStr)
+	if err != nil {
+		return
+	}
+
+	var hour, minute, second int
+	var location *time.Location = localLoc
+	if len(timeStr) != 0 {
+		hour, minute, second, err = parseTimeParts(timeStr)
+		if err != nil {
+			return
+		}
+		if len(zoneStr) != 0 {
+			var offset int
+			offset, err = parseTimezone(zoneStr)
+			if offset == 0 {
+				location = time.UTC
+			} else {
+				location = time.FixedZone("", offset)
+			}
+		}
+	}
+
+	result = time.Date(year, time.Month(month), day, hour, minute, second, 0, location)
+	return
+}
+
+// MarshalBoolean marshals bool to SOAP "boolean" type.
+func MarshalBoolean(v bool) (string, error) {
+	if v {
+		return "1", nil
+	}
+	return "0", nil
+}
+
+// UnmarshalBoolean unmarshals bool from the SOAP "boolean" type.
+func UnmarshalBoolean(s string) (bool, error) {
+	switch s {
+	case "0", "false", "no":
+		return false, nil
+	case "1", "true", "yes":
+		return true, nil
+	}
+	return false, fmt.Errorf("soap boolean: %q is not a valid boolean value", s)
+}
+
+// MarshalBinBase64 marshals []byte to SOAP "bin.base64" type.
+func MarshalBinBase64(v []byte) (string, error) {
+	return base64.StdEncoding.EncodeToString(v), nil
+}
+
+// UnmarshalBinBase64 unmarshals []byte from the SOAP "bin.base64" type.
+func UnmarshalBinBase64(s string) ([]byte, error) {
+	return base64.StdEncoding.DecodeString(s)
+}
+
+// MarshalBinHex marshals []byte to SOAP "bin.hex" type.
+func MarshalBinHex(v []byte) (string, error) {
+	return hex.EncodeToString(v), nil
+}
+
+// UnmarshalBinHex unmarshals []byte from the SOAP "bin.hex" type.
+func UnmarshalBinHex(s string) ([]byte, error) {
+	return hex.DecodeString(s)
+}
+
+// MarshalURI marshals *url.URL to SOAP "uri" type.
+func MarshalURI(v *url.URL) (string, error) {
+	return v.String(), nil
+}
+
+// UnmarshalURI unmarshals *url.URL from the SOAP "uri" type.
+func UnmarshalURI(s string) (*url.URL, error) {
+	return url.Parse(s)
+}

net/upnp/soap/types_test.go

@@ -0,0 +1,497 @@
+package soap
+
+import (
+	"bytes"
+	"math"
+	"net/url"
+	"testing"
+	"time"
+)
+
+type convTest interface {
+	Marshal() (string, error)
+	Unmarshal(string) (interface{}, error)
+	Equal(result interface{}) bool
+}
+
+// duper is an interface that convTest values may optionally also implement to
+// generate another convTest for a value in an otherwise identical testCase.
+type duper interface {
+	Dupe(tag string) []convTest
+}
+
+type testCase struct {
+	value            convTest
+	str              string
+	wantMarshalErr   bool
+	wantUnmarshalErr bool
+	noMarshal        bool
+	noUnMarshal      bool
+	tag              string
+}
+
+type Ui1Test uint8
+
+func (v Ui1Test) Marshal() (string, error) {
+	return MarshalUi1(uint8(v))
+}
+func (v Ui1Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalUi1(s)
+}
+func (v Ui1Test) Equal(result interface{}) bool {
+	return uint8(v) == result.(uint8)
+}
+func (v Ui1Test) Dupe(tag string) []convTest {
+	if tag == "dupe" {
+		return []convTest{
+			Ui2Test(v),
+			Ui4Test(v),
+		}
+	}
+	return nil
+}
+
+type Ui2Test uint16
+
+func (v Ui2Test) Marshal() (string, error) {
+	return MarshalUi2(uint16(v))
+}
+func (v Ui2Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalUi2(s)
+}
+func (v Ui2Test) Equal(result interface{}) bool {
+	return uint16(v) == result.(uint16)
+}
+
+type Ui4Test uint32
+
+func (v Ui4Test) Marshal() (string, error) {
+	return MarshalUi4(uint32(v))
+}
+func (v Ui4Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalUi4(s)
+}
+func (v Ui4Test) Equal(result interface{}) bool {
+	return uint32(v) == result.(uint32)
+}
+
+type I1Test int8
+
+func (v I1Test) Marshal() (string, error) {
+	return MarshalI1(int8(v))
+}
+func (v I1Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalI1(s)
+}
+func (v I1Test) Equal(result interface{}) bool {
+	return int8(v) == result.(int8)
+}
+func (v I1Test) Dupe(tag string) []convTest {
+	if tag == "dupe" {
+		return []convTest{
+			I2Test(v),
+			I4Test(v),
+		}
+	}
+	return nil
+}
+
+type I2Test int16
+
+func (v I2Test) Marshal() (string, error) {
+	return MarshalI2(int16(v))
+}
+func (v I2Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalI2(s)
+}
+func (v I2Test) Equal(result interface{}) bool {
+	return int16(v) == result.(int16)
+}
+
+type I4Test int32
+
+func (v I4Test) Marshal() (string, error) {
+	return MarshalI4(int32(v))
+}
+func (v I4Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalI4(s)
+}
+func (v I4Test) Equal(result interface{}) bool {
+	return int32(v) == result.(int32)
+}
+
+type IntTest int64
+
+func (v IntTest) Marshal() (string, error) {
+	return MarshalInt(int64(v))
+}
+func (v IntTest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalInt(s)
+}
+func (v IntTest) Equal(result interface{}) bool {
+	return int64(v) == result.(int64)
+}
+
+type Fixed14_4Test float64
+
+func (v Fixed14_4Test) Marshal() (string, error) {
+	return MarshalFixed14_4(float64(v))
+}
+func (v Fixed14_4Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalFixed14_4(s)
+}
+func (v Fixed14_4Test) Equal(result interface{}) bool {
+	return math.Abs(float64(v)-result.(float64)) < 0.001
+}
+
+type CharTest rune
+
+func (v CharTest) Marshal() (string, error) {
+	return MarshalChar(rune(v))
+}
+func (v CharTest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalChar(s)
+}
+func (v CharTest) Equal(result interface{}) bool {
+	return rune(v) == result.(rune)
+}
+
+type DateTest struct{ time.Time }
+
+func (v DateTest) Marshal() (string, error) {
+	return MarshalDate(time.Time(v.Time))
+}
+func (v DateTest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalDate(s)
+}
+func (v DateTest) Equal(result interface{}) bool {
+	return v.Time.Equal(result.(time.Time))
+}
+func (v DateTest) Dupe(tag string) []convTest {
+	if tag != "no:dateTime" {
+		return []convTest{DateTimeTest(v)}
+	}
+	return nil
+}
+
+type TimeOfDayTest struct {
+	TimeOfDay
+}
+
+func (v TimeOfDayTest) Marshal() (string, error) {
+	return MarshalTimeOfDay(v.TimeOfDay)
+}
+func (v TimeOfDayTest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalTimeOfDay(s)
+}
+func (v TimeOfDayTest) Equal(result interface{}) bool {
+	return v.TimeOfDay == result.(TimeOfDay)
+}
+func (v TimeOfDayTest) Dupe(tag string) []convTest {
+	if tag != "no:time.tz" {
+		return []convTest{TimeOfDayTzTest(v)}
+	}
+	return nil
+}
+
+type TimeOfDayTzTest struct {
+	TimeOfDay
+}
+
+func (v TimeOfDayTzTest) Marshal() (string, error) {
+	return MarshalTimeOfDayTz(v.TimeOfDay)
+}
+func (v TimeOfDayTzTest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalTimeOfDayTz(s)
+}
+func (v TimeOfDayTzTest) Equal(result interface{}) bool {
+	return v.TimeOfDay == result.(TimeOfDay)
+}
+
+type DateTimeTest struct{ time.Time }
+
+func (v DateTimeTest) Marshal() (string, error) {
+	return MarshalDateTime(time.Time(v.Time))
+}
+func (v DateTimeTest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalDateTime(s)
+}
+func (v DateTimeTest) Equal(result interface{}) bool {
+	return v.Time.Equal(result.(time.Time))
+}
+func (v DateTimeTest) Dupe(tag string) []convTest {
+	if tag != "no:dateTime.tz" {
+		return []convTest{DateTimeTzTest(v)}
+	}
+	return nil
+}
+
+type DateTimeTzTest struct{ time.Time }
+
+func (v DateTimeTzTest) Marshal() (string, error) {
+	return MarshalDateTimeTz(time.Time(v.Time))
+}
+func (v DateTimeTzTest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalDateTimeTz(s)
+}
+func (v DateTimeTzTest) Equal(result interface{}) bool {
+	return v.Time.Equal(result.(time.Time))
+}
+
+type BooleanTest bool
+
+func (v BooleanTest) Marshal() (string, error) {
+	return MarshalBoolean(bool(v))
+}
+func (v BooleanTest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalBoolean(s)
+}
+func (v BooleanTest) Equal(result interface{}) bool {
+	return bool(v) == result.(bool)
+}
+
+type BinBase64Test []byte
+
+func (v BinBase64Test) Marshal() (string, error) {
+	return MarshalBinBase64([]byte(v))
+}
+func (v BinBase64Test) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalBinBase64(s)
+}
+func (v BinBase64Test) Equal(result interface{}) bool {
+	return bytes.Equal([]byte(v), result.([]byte))
+}
+
+type BinHexTest []byte
+
+func (v BinHexTest) Marshal() (string, error) {
+	return MarshalBinHex([]byte(v))
+}
+func (v BinHexTest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalBinHex(s)
+}
+func (v BinHexTest) Equal(result interface{}) bool {
+	return bytes.Equal([]byte(v), result.([]byte))
+}
+
+type URITest struct{ URL *url.URL }
+
+func (v URITest) Marshal() (string, error) {
+	return MarshalURI(v.URL)
+}
+func (v URITest) Unmarshal(s string) (interface{}, error) {
+	return UnmarshalURI(s)
+}
+func (v URITest) Equal(result interface{}) bool {
+	return v.URL.String() == result.(*url.URL).String()
+}
+
+func Test(t *testing.T) {
+	const time010203 time.Duration = (1*3600 + 2*60 + 3) * time.Second
+	const time0102 time.Duration = (1*3600 + 2*60) * time.Second
+	const time01 time.Duration = (1 * 3600) * time.Second
+	const time235959 time.Duration = (23*3600 + 59*60 + 59) * time.Second
+
+	// Fake out the local time for the implementation.
+	localLoc = time.FixedZone("Fake/Local", 6*3600)
+	defer func() {
+		localLoc = time.Local
+	}()
+
+	tests := []testCase{
+		// ui1
+		{str: "", value: Ui1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: " ", value: Ui1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: "abc", value: Ui1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: "-1", value: Ui1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: "0", value: Ui1Test(0), tag: "dupe"},
+		{str: "1", value: Ui1Test(1), tag: "dupe"},
+		{str: "255", value: Ui1Test(255), tag: "dupe"},
+		{str: "256", value: Ui1Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// ui2
+		{str: "65535", value: Ui2Test(65535)},
+		{str: "65536", value: Ui2Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// ui4
+		{str: "4294967295", value: Ui4Test(4294967295)},
+		{str: "4294967296", value: Ui4Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// i1
+		{str: "", value: I1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: " ", value: I1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: "abc", value: I1Test(0), wantUnmarshalErr: true, noMarshal: true, tag: "dupe"},
+		{str: "0", value: I1Test(0), tag: "dupe"},
+		{str: "-1", value: I1Test(-1), tag: "dupe"},
+		{str: "127", value: I1Test(127), tag: "dupe"},
+		{str: "-128", value: I1Test(-128), tag: "dupe"},
+		{str: "128", value: I1Test(0), wantUnmarshalErr: true, noMarshal: true},
+		{str: "-129", value: I1Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// i2
+		{str: "32767", value: I2Test(32767)},
+		{str: "-32768", value: I2Test(-32768)},
+		{str: "32768", value: I2Test(0), wantUnmarshalErr: true, noMarshal: true},
+		{str: "-32769", value: I2Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// i4
+		{str: "2147483647", value: I4Test(2147483647)},
+		{str: "-2147483648", value: I4Test(-2147483648)},
+		{str: "2147483648", value: I4Test(0), wantUnmarshalErr: true, noMarshal: true},
+		{str: "-2147483649", value: I4Test(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// int
+		{str: "9223372036854775807", value: IntTest(9223372036854775807)},
+		{str: "-9223372036854775808", value: IntTest(-9223372036854775808)},
+		{str: "9223372036854775808", value: IntTest(0), wantUnmarshalErr: true, noMarshal: true},
+		{str: "-9223372036854775809", value: IntTest(0), wantUnmarshalErr: true, noMarshal: true},
+
+		// fixed.14.4
+		{str: "0.0000", value: Fixed14_4Test(0)},
+		{str: "1.0000", value: Fixed14_4Test(1)},
+		{str: "1.2346", value: Fixed14_4Test(1.23456)},
+		{str: "-1.0000", value: Fixed14_4Test(-1)},
+		{str: "-1.2346", value: Fixed14_4Test(-1.23456)},
+		{str: "10000000000000.0000", value: Fixed14_4Test(1e13)},
+		{str: "100000000000000.0000", value: Fixed14_4Test(1e14), wantMarshalErr: true, wantUnmarshalErr: true},
+		{str: "-10000000000000.0000", value: Fixed14_4Test(-1e13)},
+		{str: "-100000000000000.0000", value: Fixed14_4Test(-1e14), wantMarshalErr: true, wantUnmarshalErr: true},
+
+		// char
+		{str: "a", value: CharTest('a')},
+		{str: "z", value: CharTest('z')},
+		{str: "\u1234", value: CharTest(0x1234)},
+		{str: "aa", value: CharTest(0), wantMarshalErr: true, wantUnmarshalErr: true},
+		{str: "", value: CharTest(0), wantMarshalErr: true, wantUnmarshalErr: true},
+
+		// date
+		{str: "2013-10-08", value: DateTest{time.Date(2013, 10, 8, 0, 0, 0, 0, localLoc)}, tag: "no:dateTime"},
+		{str: "20131008", value: DateTest{time.Date(2013, 10, 8, 0, 0, 0, 0, localLoc)}, noMarshal: true, tag: "no:dateTime"},
+		{str: "2013-10-08T10:30:50", value: DateTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:dateTime"},
+		{str: "2013-10-08T10:30:50Z", value: DateTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:dateTime"},
+		{str: "", value: DateTest{}, wantMarshalErr: true, wantUnmarshalErr: true, noMarshal: true},
+		{str: "-1", value: DateTest{}, wantUnmarshalErr: true, noMarshal: true},
+
+		// time
+		{str: "00:00:00", value: TimeOfDayTest{TimeOfDay{FromMidnight: 0}}},
+		{str: "000000", value: TimeOfDayTest{TimeOfDay{FromMidnight: 0}}, noMarshal: true},
+		{str: "24:00:00", value: TimeOfDayTest{TimeOfDay{FromMidnight: 24 * time.Hour}}, noMarshal: true}, // ISO8601 special case
+		{str: "24:01:00", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true},
+		{str: "24:00:01", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true},
+		{str: "25:00:00", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true},
+		{str: "00:60:00", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true},
+		{str: "00:00:60", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true},
+		{str: "01:02:03", value: TimeOfDayTest{TimeOfDay{FromMidnight: time010203}}},
+		{str: "010203", value: TimeOfDayTest{TimeOfDay{FromMidnight: time010203}}, noMarshal: true},
+		{str: "23:59:59", value: TimeOfDayTest{TimeOfDay{FromMidnight: time235959}}},
+		{str: "235959", value: TimeOfDayTest{TimeOfDay{FromMidnight: time235959}}, noMarshal: true},
+		{str: "01:02", value: TimeOfDayTest{TimeOfDay{FromMidnight: time0102}}, noMarshal: true},
+		{str: "0102", value: TimeOfDayTest{TimeOfDay{FromMidnight: time0102}}, noMarshal: true},
+		{str: "01", value: TimeOfDayTest{TimeOfDay{FromMidnight: time01}}, noMarshal: true},
+		{str: "foo 01:02:03", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+		{str: "foo\n01:02:03", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+		{str: "01:02:03 foo", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+		{str: "01:02:03\nfoo", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+		{str: "01:02:03Z", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+		{str: "01:02:03+01", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+		{str: "01:02:03+01:23", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+		{str: "01:02:03+0123", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+		{str: "01:02:03-01", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+		{str: "01:02:03-01:23", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+		{str: "01:02:03-0123", value: TimeOfDayTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:time.tz"},
+
+		// time.tz
+		{str: "24:00:01", value: TimeOfDayTzTest{}, wantUnmarshalErr: true, noMarshal: true},
+		{str: "01Z", value: TimeOfDayTzTest{TimeOfDay{time01, true, 0}}, noMarshal: true},
+		{str: "01:02:03Z", value: TimeOfDayTzTest{TimeOfDay{time010203, true, 0}}},
+		{str: "01+01", value: TimeOfDayTzTest{TimeOfDay{time01, true, 3600}}, noMarshal: true},
+		{str: "01:02:03+01", value: TimeOfDayTzTest{TimeOfDay{time010203, true, 3600}}, noMarshal: true},
+		{str: "01:02:03+01:23", value: TimeOfDayTzTest{TimeOfDay{time010203, true, 3600 + 23*60}}},
+		{str: "01:02:03+0123", value: TimeOfDayTzTest{TimeOfDay{time010203, true, 3600 + 23*60}}, noMarshal: true},
+		{str: "01:02:03-01", value: TimeOfDayTzTest{TimeOfDay{time010203, true, -3600}}, noMarshal: true},
+		{str: "01:02:03-01:23", value: TimeOfDayTzTest{TimeOfDay{time010203, true, -(3600 + 23*60)}}},
+		{str: "01:02:03-0123", value: TimeOfDayTzTest{TimeOfDay{time010203, true, -(3600 + 23*60)}}, noMarshal: true},
+
+		// dateTime
+		{str: "2013-10-08T00:00:00", value: DateTimeTest{time.Date(2013, 10, 8, 0, 0, 0, 0, localLoc)}, tag: "no:dateTime.tz"},
+		{str: "20131008", value: DateTimeTest{time.Date(2013, 10, 8, 0, 0, 0, 0, localLoc)}, noMarshal: true},
+		{str: "2013-10-08T10:30:50", value: DateTimeTest{time.Date(2013, 10, 8, 10, 30, 50, 0, localLoc)}, tag: "no:dateTime.tz"},
+		{str: "2013-10-08T10:30:50T", value: DateTimeTest{}, wantUnmarshalErr: true, noMarshal: true},
+		{str: "2013-10-08T10:30:50+01", value: DateTimeTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:dateTime.tz"},
+		{str: "2013-10-08T10:30:50+01:23", value: DateTimeTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:dateTime.tz"},
+		{str: "2013-10-08T10:30:50+0123", value: DateTimeTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:dateTime.tz"},
+		{str: "2013-10-08T10:30:50-01", value: DateTimeTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:dateTime.tz"},
+		{str: "2013-10-08T10:30:50-01:23", value: DateTimeTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:dateTime.tz"},
+		{str: "2013-10-08T10:30:50-0123", value: DateTimeTest{}, wantUnmarshalErr: true, noMarshal: true, tag: "no:dateTime.tz"},
+
+		// dateTime.tz
+		{str: "2013-10-08T10:30:50", value: DateTimeTzTest{time.Date(2013, 10, 8, 10, 30, 50, 0, localLoc)}, noMarshal: true},
+		{str: "2013-10-08T10:30:50+01", value: DateTimeTzTest{time.Date(2013, 10, 8, 10, 30, 50, 0, time.FixedZone("+01:00", 3600))}, noMarshal: true},
+		{str: "2013-10-08T10:30:50+01:23", value: DateTimeTzTest{time.Date(2013, 10, 8, 10, 30, 50, 0, time.FixedZone("+01:23", 3600+23*60))}},
+		{str: "2013-10-08T10:30:50+0123", value: DateTimeTzTest{time.Date(2013, 10, 8, 10, 30, 50, 0, time.FixedZone("+01:23", 3600+23*60))}, noMarshal: true},
+		{str: "2013-10-08T10:30:50-01", value: DateTimeTzTest{time.Date(2013, 10, 8, 10, 30, 50, 0, time.FixedZone("-01:00", -3600))}, noMarshal: true},
+		{str: "2013-10-08T10:30:50-01:23", value: DateTimeTzTest{time.Date(2013, 10, 8, 10, 30, 50, 0, time.FixedZone("-01:23", -(3600+23*60)))}},
+		{str: "2013-10-08T10:30:50-0123", value: DateTimeTzTest{time.Date(2013, 10, 8, 10, 30, 50, 0, time.FixedZone("-01:23", -(3600+23*60)))}, noMarshal: true},
+
+		// boolean
+		{str: "0", value: BooleanTest(false)},
+		{str: "1", value: BooleanTest(true)},
+		{str: "false", value: BooleanTest(false), noMarshal: true},
+		{str: "true", value: BooleanTest(true), noMarshal: true},
+		{str: "no", value: BooleanTest(false), noMarshal: true},
+		{str: "yes", value: BooleanTest(true), noMarshal: true},
+		{str: "", value: BooleanTest(false), noMarshal: true, wantUnmarshalErr: true},
+		{str: "other", value: BooleanTest(false), noMarshal: true, wantUnmarshalErr: true},
+		{str: "2", value: BooleanTest(false), noMarshal: true, wantUnmarshalErr: true},
+		{str: "-1", value: BooleanTest(false), noMarshal: true, wantUnmarshalErr: true},
+
+		// bin.base64
+		{str: "", value: BinBase64Test{}},
+		{str: "YQ==", value: BinBase64Test("a")},
+		{str: "TG9uZ2VyIFN0cmluZy4=", value: BinBase64Test("Longer String.")},
+		{str: "TG9uZ2VyIEFsaWduZWQu", value: BinBase64Test("Longer Aligned.")},
+
+		// bin.hex
+		{str: "", value: BinHexTest{}},
+		{str: "61", value: BinHexTest("a")},
+		{str: "4c6f6e67657220537472696e672e", value: BinHexTest("Longer String.")},
+		{str: "4C6F6E67657220537472696E672E", value: BinHexTest("Longer String."), noMarshal: true},
+
+		// uri
+		{str: "http://example.com/path", value: URITest{&url.URL{Scheme: "http", Host: "example.com", Path: "/path"}}},
+	}
+
+	// Generate extra test cases from convTests that implement duper.
+	var extras []testCase
+	for i := range tests {
+		if duper, ok := tests[i].value.(duper); ok {
+			dupes := duper.Dupe(tests[i].tag)
+			for _, duped := range dupes {
+				dupedCase := testCase(tests[i])
+				dupedCase.value = duped
+				extras = append(extras, dupedCase)
+			}
+		}
+	}
+	tests = append(tests, extras...)
+
+	for _, test := range tests {
+		if test.noMarshal {
+		} else if resultStr, err := test.value.Marshal(); err != nil && !test.wantMarshalErr {
+			t.Errorf("For %T marshal %v, want %q, got error: %v", test.value, test.value, test.str, err)
+		} else if err == nil && test.wantMarshalErr {
+			t.Errorf("For %T marshal %v, want error, got %q", test.value, test.value, resultStr)
+		} else if err == nil && resultStr != test.str {
+			t.Errorf("For %T marshal %v, want %q, got %q", test.value, test.value, test.str, resultStr)
+		}
+
+		if test.noUnMarshal {
+		} else if resultValue, err := test.value.Unmarshal(test.str); err != nil && !test.wantUnmarshalErr {
+			t.Errorf("For %T unmarshal %q, want %v, got error: %v", test.value, test.str, test.value, err)
+		} else if err == nil && test.wantUnmarshalErr {
+			t.Errorf("For %T unmarshal %q, want error, got %v", test.value, test.str, resultValue)
+		} else if err == nil && !test.value.Equal(resultValue) {
+			t.Errorf("For %T unmarshal %q, want %v, got %v", test.value, test.str, test.value, resultValue)
+		}
+	}
+}

net/upnp/ssdp/registry.go

@@ -0,0 +1,312 @@
+package ssdp
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strconv"
+	"sync"
+	"time"
+
+	"tailscale.com/net/upnp/httpu"
+)
+
+const (
+	maxExpiryTimeSeconds = 24 * 60 * 60
+)
+
+var (
+	maxAgeRx = regexp.MustCompile("max-age= *([0-9]+)")
+)
+
+const (
+	EventAlive = EventType(iota)
+	EventUpdate
+	EventByeBye
+)
+
+type EventType int8
+
+func (et EventType) String() string {
+	switch et {
+	case EventAlive:
+		return "EventAlive"
+	case EventUpdate:
+		return "EventUpdate"
+	case EventByeBye:
+		return "EventByeBye"
+	default:
+		return fmt.Sprintf("EventUnknown(%d)", int8(et))
+	}
+}
+
+type Update struct {
+	// The USN of the service.
+	USN string
+	// What happened.
+	EventType EventType
+	// The entry, which is nil if the service was not known and
+	// EventType==EventByeBye. The contents of this must not be modified as it is
+	// shared with the registry and other listeners. Once created, the Registry
+	// does not modify the Entry value - any updates are replaced with a new
+	// Entry value.
+	Entry *Entry
+}
+
+type Entry struct {
+	// The address that the entry data was actually received from.
+	RemoteAddr string
+	// Unique Service Name. Identifies a unique instance of a device or service.
+	USN string
+	// Notfication Type. The type of device or service being announced.
+	NT string
+	// Server's self-identifying string.
+	Server string
+	Host   string
+	// Location of the UPnP root device description.
+	Location url.URL
+
+	// Despite BOOTID,CONFIGID being required fields, apparently they are not
+	// always set by devices. Set to -1 if not present.
+
+	BootID   int32
+	ConfigID int32
+
+	SearchPort uint16
+
+	// When the last update was received for this entry identified by this USN.
+	LastUpdate time.Time
+	// When the last update's cached values are advised to expire.
+	CacheExpiry time.Time
+}
+
+func newEntryFromRequest(r *http.Request) (*Entry, error) {
+	now := time.Now()
+	expiryDuration, err := parseCacheControlMaxAge(r.Header.Get("CACHE-CONTROL"))
+	if err != nil {
+		return nil, fmt.Errorf("ssdp: error parsing CACHE-CONTROL max age: %v", err)
+	}
+
+	loc, err := url.Parse(r.Header.Get("LOCATION"))
+	if err != nil {
+		return nil, fmt.Errorf("ssdp: error parsing entry Location URL: %v", err)
+	}
+
+	bootID, err := parseUpnpIntHeader(r.Header, "BOOTID.UPNP.ORG", -1)
+	if err != nil {
+		return nil, err
+	}
+	configID, err := parseUpnpIntHeader(r.Header, "CONFIGID.UPNP.ORG", -1)
+	if err != nil {
+		return nil, err
+	}
+	searchPort, err := parseUpnpIntHeader(r.Header, "SEARCHPORT.UPNP.ORG", ssdpSearchPort)
+	if err != nil {
+		return nil, err
+	}
+
+	if searchPort < 1 || searchPort > 65535 {
+		return nil, fmt.Errorf("ssdp: search port %d is out of range", searchPort)
+	}
+
+	return &Entry{
+		RemoteAddr:  r.RemoteAddr,
+		USN:         r.Header.Get("USN"),
+		NT:          r.Header.Get("NT"),
+		Server:      r.Header.Get("SERVER"),
+		Host:        r.Header.Get("HOST"),
+		Location:    *loc,
+		BootID:      bootID,
+		ConfigID:    configID,
+		SearchPort:  uint16(searchPort),
+		LastUpdate:  now,
+		CacheExpiry: now.Add(expiryDuration),
+	}, nil
+}
+
+func parseCacheControlMaxAge(cc string) (time.Duration, error) {
+	matches := maxAgeRx.FindStringSubmatch(cc)
+	if len(matches) != 2 {
+		return 0, fmt.Errorf("did not find exactly one max-age in cache control header: %q", cc)
+	}
+	expirySeconds, err := strconv.ParseInt(matches[1], 10, 16)
+	if err != nil {
+		return 0, err
+	}
+	if expirySeconds < 1 || expirySeconds > maxExpiryTimeSeconds {
+		return 0, fmt.Errorf("rejecting bad expiry time of %d seconds", expirySeconds)
+	}
+	return time.Duration(expirySeconds) * time.Second, nil
+}
+
+// parseUpnpIntHeader is intended to parse the
+// {BOOT,CONFIGID,SEARCHPORT}.UPNP.ORG header fields. It returns the def if
+// the head is empty or missing.
+func parseUpnpIntHeader(headers http.Header, headerName string, def int32) (int32, error) {
+	s := headers.Get(headerName)
+	if s == "" {
+		return def, nil
+	}
+	v, err := strconv.ParseInt(s, 10, 32)
+	if err != nil {
+		return 0, fmt.Errorf("ssdp: could not parse header %s: %v", headerName, err)
+	}
+	return int32(v), nil
+}
+
+var _ httpu.Handler = new(Registry)
+
+// Registry maintains knowledge of discovered devices and services.
+//
+// NOTE: the interface for this is experimental and may change, or go away
+// entirely.
+type Registry struct {
+	lock  sync.Mutex
+	byUSN map[string]*Entry
+
+	listenersLock sync.RWMutex
+	listeners     map[chan<- Update]struct{}
+}
+
+func NewRegistry() *Registry {
+	return &Registry{
+		byUSN:     make(map[string]*Entry),
+		listeners: make(map[chan<- Update]struct{}),
+	}
+}
+
+// NewServerAndRegistry is a convenience function to create a registry, and an
+// httpu server to pass it messages. Call ListenAndServe on the server for
+// messages to be processed.
+func NewServerAndRegistry() (*httpu.Server, *Registry) {
+	reg := NewRegistry()
+	srv := &httpu.Server{
+		Addr:      ssdpUDP4Addr,
+		Multicast: true,
+		Handler:   reg,
+	}
+	return srv, reg
+}
+
+func (reg *Registry) AddListener(c chan<- Update) {
+	reg.listenersLock.Lock()
+	defer reg.listenersLock.Unlock()
+	reg.listeners[c] = struct{}{}
+}
+
+func (reg *Registry) RemoveListener(c chan<- Update) {
+	reg.listenersLock.Lock()
+	defer reg.listenersLock.Unlock()
+	delete(reg.listeners, c)
+}
+
+func (reg *Registry) sendUpdate(u Update) {
+	reg.listenersLock.RLock()
+	defer reg.listenersLock.RUnlock()
+	for c := range reg.listeners {
+		c <- u
+	}
+}
+
+// GetService returns known service (or device) entries for the given service
+// URN.
+func (reg *Registry) GetService(serviceURN string) []*Entry {
+	// Currently assumes that the map is small, so we do a linear search rather
+	// than indexed to avoid maintaining two maps.
+	var results []*Entry
+	reg.lock.Lock()
+	defer reg.lock.Unlock()
+	for _, entry := range reg.byUSN {
+		if entry.NT == serviceURN {
+			results = append(results, entry)
+		}
+	}
+	return results
+}
+
+// ServeMessage implements httpu.Handler, and uses SSDP NOTIFY requests to
+// maintain the registry of devices and services.
+func (reg *Registry) ServeMessage(r *http.Request) {
+	if r.Method != methodNotify {
+		return
+	}
+
+	nts := r.Header.Get("nts")
+
+	var err error
+	switch nts {
+	case ntsAlive:
+		err = reg.handleNTSAlive(r)
+	case ntsUpdate:
+		err = reg.handleNTSUpdate(r)
+	case ntsByebye:
+		err = reg.handleNTSByebye(r)
+	default:
+		err = fmt.Errorf("unknown NTS value: %q", nts)
+	}
+	if err != nil {
+		log.Printf("goupnp/ssdp: failed to handle %s message from %s: %v", nts, r.RemoteAddr, err)
+	}
+}
+
+func (reg *Registry) handleNTSAlive(r *http.Request) error {
+	entry, err := newEntryFromRequest(r)
+	if err != nil {
+		return err
+	}
+
+	reg.lock.Lock()
+	reg.byUSN[entry.USN] = entry
+	reg.lock.Unlock()
+
+	reg.sendUpdate(Update{
+		USN:       entry.USN,
+		EventType: EventAlive,
+		Entry:     entry,
+	})
+
+	return nil
+}
+
+func (reg *Registry) handleNTSUpdate(r *http.Request) error {
+	entry, err := newEntryFromRequest(r)
+	if err != nil {
+		return err
+	}
+	nextBootID, err := parseUpnpIntHeader(r.Header, "NEXTBOOTID.UPNP.ORG", -1)
+	if err != nil {
+		return err
+	}
+	entry.BootID = nextBootID
+
+	reg.lock.Lock()
+	reg.byUSN[entry.USN] = entry
+	reg.lock.Unlock()
+
+	reg.sendUpdate(Update{
+		USN:       entry.USN,
+		EventType: EventUpdate,
+		Entry:     entry,
+	})
+
+	return nil
+}
+
+func (reg *Registry) handleNTSByebye(r *http.Request) error {
+	usn := r.Header.Get("USN")
+
+	reg.lock.Lock()
+	entry := reg.byUSN[usn]
+	delete(reg.byUSN, usn)
+	reg.lock.Unlock()
+
+	reg.sendUpdate(Update{
+		USN:       usn,
+		EventType: EventByeBye,
+		Entry:     entry,
+	})
+
+	return nil
+}

net/upnp/ssdp/ssdp.go

@@ -0,0 +1,102 @@
+package ssdp
+
+import (
+	"errors"
+	"log"
+	"net/http"
+	"net/url"
+	"strconv"
+	"time"
+)
+
+const (
+	ssdpDiscover   = `"ssdp:discover"`
+	ntsAlive       = `ssdp:alive`
+	ntsByebye      = `ssdp:byebye`
+	ntsUpdate      = `ssdp:update`
+	ssdpUDP4Addr   = "239.255.255.250:1900"
+	ssdpSearchPort = 1900
+	methodSearch   = "M-SEARCH"
+	methodNotify   = "NOTIFY"
+
+	// SSDPAll is a value for searchTarget that searches for all devices and services.
+	SSDPAll = "ssdp:all"
+	// UPNPRootDevice is a value for searchTarget that searches for all root devices.
+	UPNPRootDevice = "upnp:rootdevice"
+)
+
+// HTTPUClient is the interface required to perform HTTP-over-UDP requests.
+type HTTPUClient interface {
+	Do(
+		req *http.Request,
+		timeout time.Duration,
+		numSends int,
+	) ([]*http.Response, error)
+}
+
+// SSDPRawSearch performs a fairly raw SSDP search request, and returns the
+// unique response(s) that it receives. Each response has the requested
+// searchTarget, a USN, and a valid location. maxWaitSeconds states how long to
+// wait for responses in seconds, and must be a minimum of 1 (the
+// implementation waits an additional 100ms for responses to arrive), 2 is a
+// reasonable value for this. numSends is the number of requests to send - 3 is
+// a reasonable value for this.
+func SSDPRawSearch(
+	httpu HTTPUClient,
+	searchTarget string,
+	maxWaitSeconds int,
+	numSends int,
+) ([]*http.Response, error) {
+	if maxWaitSeconds < 1 {
+		return nil, errors.New("ssdp: maxWaitSeconds must be >= 1")
+	}
+
+	req := http.Request{
+		Method: methodSearch,
+		// TODO: Support both IPv4 and IPv6.
+		Host: ssdpUDP4Addr,
+		URL:  &url.URL{Opaque: "*"},
+		Header: http.Header{
+			// Putting headers in here avoids them being title-cased.
+			// (The UPnP discovery protocol uses case-sensitive headers)
+			"HOST": []string{ssdpUDP4Addr},
+			"MX":   []string{strconv.FormatInt(int64(maxWaitSeconds), 10)},
+			"MAN":  []string{ssdpDiscover},
+			"ST":   []string{searchTarget},
+		},
+	}
+	allResponses, err := httpu.Do(&req, time.Duration(maxWaitSeconds)*time.Second+100*time.Millisecond, numSends)
+	if err != nil {
+		return nil, err
+	}
+
+	isExactSearch := searchTarget != SSDPAll && searchTarget != UPNPRootDevice
+
+	seenUSNs := make(map[string]bool)
+	var responses []*http.Response
+	for _, response := range allResponses {
+		if response.StatusCode != 200 {
+			log.Printf("ssdp: got response status code %q in search response", response.Status)
+			continue
+		}
+		if st := response.Header.Get("ST"); isExactSearch && st != searchTarget {
+			continue
+		}
+		usn := response.Header.Get("USN")
+		if usn == "" {
+			// Empty/missing USN in search response - using location instead.
+			location, err := response.Location()
+			if err != nil {
+				// No usable location in search response - discard.
+				continue
+			}
+			usn = location.String()
+		}
+		if _, alreadySeen := seenUSNs[usn]; !alreadySeen {
+			seenUSNs[usn] = true
+			responses = append(responses, response)
+		}
+	}
+
+	return responses, nil
+}