rclone/vendor/github.com/anacrolix/dms/upnp/eventing.go
2019-01-09 19:14:14 +00:00

92 lines
2.3 KiB
Go

package upnp
import (
"crypto/rand"
"encoding/xml"
"fmt"
"io"
"log"
"net/url"
"regexp"
"time"
)
// TODO: Why use namespace prefixes in PropertySet et al? Because the spec
// uses them, and I believe the Golang standard library XML spec implementers
// incorrectly assume that you can get away with just xmlns="".
// propertyset is the root element sent in an event callback.
type PropertySet struct {
XMLName struct{} `xml:"e:propertyset"`
Properties []Property
// This should be set to `"urn:schemas-upnp-org:event-1-0"`.
Space string `xml:"xmlns:e,attr"`
}
// propertys provide namespacing to the contained variables.
type Property struct {
XMLName struct{} `xml:"e:property"`
Variable Variable
}
// Represents an evented state variable that has sendEvents="yes" in its
// service spec.
type Variable struct {
XMLName xml.Name
Value string `xml:",chardata"`
}
type subscriber struct {
sid string
nextSeq uint32 // 0 for initial event, wraps from Uint32Max to 1.
urls []*url.URL
expiry time.Time
}
// Intended to eventually be an embeddable implementation for managing
// eventing for a service. Not complete.
type Eventing struct {
subscribers map[string]*subscriber
}
func (me *Eventing) Subscribe(callback []*url.URL, timeoutSeconds int) (sid string, actualTimeout int, err error) {
var uuid [16]byte
io.ReadFull(rand.Reader, uuid[:])
sid = FormatUUID(uuid[:])
if _, ok := me.subscribers[sid]; ok {
err = fmt.Errorf("already subscribed: %s", sid)
return
}
ssr := &subscriber{
sid: sid,
urls: callback,
expiry: time.Now().Add(time.Duration(timeoutSeconds) * time.Second),
}
if me.subscribers == nil {
me.subscribers = make(map[string]*subscriber)
}
me.subscribers[sid] = ssr
actualTimeout = int(ssr.expiry.Sub(time.Now()) / time.Second)
return
}
func (me *Eventing) Unsubscribe(sid string) error {
return nil
}
var callbackURLRegexp = regexp.MustCompile("<(.*?)>")
// Parse the CALLBACK HTTP header in an event subscription request. See UPnP
// Device Architecture 4.1.2.
func ParseCallbackURLs(callback string) (ret []*url.URL) {
for _, match := range callbackURLRegexp.FindAllStringSubmatch(callback, -1) {
_url, err := url.Parse(match[1])
if err != nil {
log.Printf("bad callback url: %q", match[1])
continue
}
ret = append(ret, _url)
}
return
}