Add namespace delegation and priviledged entity example

_examples/delegation/README.md

@@ -0,0 +1,5 @@
+# Advanced component: delegation
+
+`delegation` is an example of advanced component supporting Namespace Delegation
+([XEP-0355](https://xmpp.org/extensions/xep-0355.html)) and privileged entity
+([XEP-356](https://xmpp.org/extensions/xep-0356.html)).

_examples/delegation/delegation.go

@@ -0,0 +1,227 @@
+package main
+
+import (
+	"encoding/xml"
+	"fmt"
+	"log"
+
+	"gosrc.io/xmpp"
+)
+
+func main() {
+	opts := xmpp.ComponentOptions{
+		Domain:  "service.localhost",
+		Secret:  "mypass",
+		Address: "localhost:9999",
+
+		// TODO: Move that part to a component discovery handler
+		Name:     "Test Component",
+		Category: "gateway",
+		Type:     "service",
+	}
+
+	router := xmpp.NewRouter()
+	router.HandleFunc("message", HandleMessage)
+	router.NewRoute().
+		IQNamespaces(xmpp.NSDiscoInfo).
+		HandlerFunc(func(s xmpp.Sender, p xmpp.Packet) {
+			DiscoInfo(s, p, opts)
+		})
+	router.NewRoute().
+		IQNamespaces("urn:xmpp:delegation:1").
+		HandlerFunc(HandleDelegation)
+
+	component, err := xmpp.NewComponent(opts, router)
+	if err != nil {
+		log.Fatalf("%+v", err)
+	}
+
+	// If you pass the component to a stream manager, it will handle the reconnect policy
+	// for you automatically.
+	// TODO: Post Connect could be a feature of the router or the client. Move it somewhere else.
+	cm := xmpp.NewStreamManager(component, nil)
+	log.Fatal(cm.Run())
+}
+
+func HandleMessage(_ xmpp.Sender, p xmpp.Packet) {
+	msg, ok := p.(xmpp.Message)
+	if !ok {
+		return
+	}
+	var msgProcessed bool
+	for _, ext := range msg.Extensions {
+		delegation, ok := ext.(*xmpp.Delegation)
+		if ok {
+			msgProcessed = true
+			fmt.Printf("Delegation confirmed for namespace %s\n", delegation.Delegated.Namespace)
+		}
+	}
+	// TODO: Decode privilege message
+	// <message to='service.localhost' from='localhost'><privilege xmlns='urn:xmpp:privilege:1'><perm type='outgoing' access='message'/><perm type='get' access='roster'/><perm type='managed_entity' access='presence'/></privilege></message>
+
+	if !msgProcessed {
+		fmt.Printf("Ignored received message, not related to delegation: %v\n", msg)
+	}
+}
+
+const (
+	pubsubNode = "urn:xmpp:delegation:1::http://jabber.org/protocol/pubsub"
+	pepNode    = "urn:xmpp:delegation:1:bare:http://jabber.org/protocol/pubsub"
+)
+
+// TODO: replace xmpp.Sender by ctx xmpp.Context ?
+// ctx.Stream.Send / SendRaw
+// ctx.Opts
+func DiscoInfo(c xmpp.Sender, p xmpp.Packet, opts xmpp.ComponentOptions) {
+	// Type conversion & sanity checks
+	iq, ok := p.(xmpp.IQ)
+	if !ok {
+		return
+	}
+	info, ok := iq.Payload[0].(*xmpp.DiscoInfo)
+	if !ok {
+		return
+	}
+
+	iqResp := xmpp.NewIQ("result", iq.To, iq.From, iq.Id, "en")
+
+	switch info.Node {
+	case "":
+		DiscoInfoRoot(&iqResp, opts)
+	case pubsubNode:
+		DiscoInfoPubSub(&iqResp)
+	case pepNode:
+		DiscoInfoPEP(&iqResp)
+	}
+
+	_ = c.Send(iqResp)
+}
+
+func DiscoInfoRoot(iqResp *xmpp.IQ, opts xmpp.ComponentOptions) {
+	// Higher level discovery
+	identity := xmpp.Identity{
+		Name:     opts.Name,
+		Category: opts.Category,
+		Type:     opts.Type,
+	}
+	payload := xmpp.DiscoInfo{
+		XMLName: xml.Name{
+			Space: xmpp.NSDiscoInfo,
+			Local: "query",
+		},
+		Identity: identity,
+		Features: []xmpp.Feature{
+			{Var: xmpp.NSDiscoInfo},
+			{Var: xmpp.NSDiscoItems},
+			{Var: "jabber:iq:version"},
+			{Var: "urn:xmpp:delegation:1"},
+		},
+	}
+	iqResp.AddPayload(&payload)
+}
+
+func DiscoInfoPubSub(iqResp *xmpp.IQ) {
+	payload := xmpp.DiscoInfo{
+		XMLName: xml.Name{
+			Space: xmpp.NSDiscoInfo,
+			Local: "query",
+		},
+		Node: pubsubNode,
+		Features: []xmpp.Feature{
+			{Var: "http://jabber.org/protocol/pubsub"},
+			{Var: "http://jabber.org/protocol/pubsub#publish"},
+			{Var: "http://jabber.org/protocol/pubsub#subscribe"},
+			{Var: "http://jabber.org/protocol/pubsub#publish-options"},
+		},
+	}
+	iqResp.AddPayload(&payload)
+}
+
+func DiscoInfoPEP(iqResp *xmpp.IQ) {
+	identity := xmpp.Identity{
+		Category: "pubsub",
+		Type:     "pep",
+	}
+	payload := xmpp.DiscoInfo{
+		XMLName: xml.Name{
+			Space: xmpp.NSDiscoInfo,
+			Local: "query",
+		},
+		Identity: identity,
+		Node:     pepNode,
+		Features: []xmpp.Feature{
+			{Var: "http://jabber.org/protocol/pubsub#access-presence"},
+			{Var: "http://jabber.org/protocol/pubsub#auto-create"},
+			{Var: "http://jabber.org/protocol/pubsub#auto-subscribe"},
+			{Var: "http://jabber.org/protocol/pubsub#config-node"},
+			{Var: "http://jabber.org/protocol/pubsub#create-and-configure"},
+			{Var: "http://jabber.org/protocol/pubsub#create-nodes"},
+			{Var: "http://jabber.org/protocol/pubsub#filtered-notifications"},
+			{Var: "http://jabber.org/protocol/pubsub#persistent-items"},
+			{Var: "http://jabber.org/protocol/pubsub#publish"},
+			{Var: "http://jabber.org/protocol/pubsub#retrieve-items"},
+			{Var: "http://jabber.org/protocol/pubsub#subscribe"},
+		},
+	}
+	iqResp.AddPayload(&payload)
+}
+
+func HandleDelegation(s xmpp.Sender, p xmpp.Packet) {
+	// Type conversion & sanity checks
+	iq, ok := p.(xmpp.IQ)
+	if !ok {
+		return
+	}
+
+	payload1 := iq.Payload[0]
+	delegation, ok := payload1.(*xmpp.Delegation)
+	if !ok {
+		return
+	}
+	forwardedPacket := delegation.Forwarded.Stanza
+	fmt.Println(forwardedPacket)
+	forwardedIQ, ok := forwardedPacket.(xmpp.IQ)
+	if !ok {
+		return
+	}
+	payload := forwardedIQ.Payload
+	if len(payload) == 0 {
+		return
+	}
+
+	pubsub, ok := payload[0].(*xmpp.PubSub)
+	if !ok {
+		// We only support pubsub delegation
+		return
+	}
+
+	if pubsub.Publish.XMLName.Local == "publish" {
+		// Prepare pubsub IQ reply
+		iqResp := xmpp.NewIQ("result", forwardedIQ.To, forwardedIQ.From, forwardedIQ.Id, "en")
+		payload := xmpp.PubSub{
+			XMLName: xml.Name{
+				Space: "http://jabber.org/protocol/pubsub",
+				Local: "pubsub",
+			},
+		}
+		iqResp.AddPayload(&payload)
+		// Wrap the reply in delegation 'forward'
+		iqForward := xmpp.NewIQ("result", iq.To, iq.From, iq.Id, "en")
+		delegPayload := xmpp.Delegation{
+			XMLName: xml.Name{
+				Space: "urn:xmpp:delegation:1",
+				Local: "delegation",
+			},
+			Forwarded: &xmpp.Forwarded{
+				XMLName: xml.Name{
+					Space: "urn:xmpp:forward:0",
+					Local: "forward",
+				},
+				Stanza: iqResp,
+			},
+		}
+		iqForward.AddPayload(&delegPayload)
+		_ = s.Send(iqForward)
+		// TODO: The component should actually broadcast the mood to subscribers
+	}
+}