1 files changed, 312 insertions, 0 deletions
diff --git a/vendor/github.com/huin/goupnp/ssdp/registry.go b/vendor/github.com/huin/goupnp/ssdp/registry.go
new file mode 100644
index 000000000..2f84beaae
--- /dev/null
+++ b/vendor/github.com/huin/goupnp/ssdp/registry.go
@@ -0,0 +1,312 @@
+package ssdp
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strconv"
+	"sync"
+	"time"
+
+	"github.com/huin/goupnp/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
+}