1/*
2 * libjingle
3 * Copyright 2004--2006, Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 *  1. Redistributions of source code must retain the above copyright notice,
9 *     this list of conditions and the following disclaimer.
10 *  2. Redistributions in binary form must reproduce the above copyright notice,
11 *     this list of conditions and the following disclaimer in the documentation
12 *     and/or other materials provided with the distribution.
13 *  3. The name of the author may not be used to endorse or promote products
14 *     derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "talk/xmpp/pubsub_task.h"
29
30#include <map>
31#include <string>
32
33#include "talk/xmpp/constants.h"
34#include "talk/xmpp/xmppengine.h"
35#include "webrtc/base/common.h"
36
37namespace buzz {
38
39PubsubTask::PubsubTask(XmppTaskParentInterface* parent,
40                       const buzz::Jid& pubsub_node_jid)
41    : buzz::XmppTask(parent, buzz::XmppEngine::HL_SENDER),
42      pubsub_node_jid_(pubsub_node_jid) {
43}
44
45PubsubTask::~PubsubTask() {
46}
47
48// Checks for pubsub publish events as well as responses to get IQs.
49bool PubsubTask::HandleStanza(const buzz::XmlElement* stanza) {
50  const buzz::QName& stanza_name(stanza->Name());
51  if (stanza_name == buzz::QN_MESSAGE) {
52    if (MatchStanzaFrom(stanza, pubsub_node_jid_)) {
53      const buzz::XmlElement* pubsub_event_item =
54          stanza->FirstNamed(QN_PUBSUB_EVENT);
55      if (pubsub_event_item != NULL) {
56        QueueStanza(pubsub_event_item);
57        return true;
58      }
59    }
60  } else if (stanza_name == buzz::QN_IQ) {
61    if (MatchResponseIq(stanza, pubsub_node_jid_, task_id())) {
62      const buzz::XmlElement* pubsub_item = stanza->FirstNamed(QN_PUBSUB);
63      if (pubsub_item != NULL) {
64        QueueStanza(pubsub_item);
65        return true;
66      }
67    }
68  }
69  return false;
70}
71
72int PubsubTask::ProcessResponse() {
73  const buzz::XmlElement* stanza = NextStanza();
74  if (stanza == NULL) {
75    return STATE_BLOCKED;
76  }
77
78  if (stanza->Attr(buzz::QN_TYPE) == buzz::STR_ERROR) {
79    OnPubsubError(stanza->FirstNamed(buzz::QN_ERROR));
80    return STATE_RESPONSE;
81  }
82
83  const buzz::QName& stanza_name(stanza->Name());
84  if (stanza_name == QN_PUBSUB_EVENT) {
85    HandlePubsubEventMessage(stanza);
86  } else if (stanza_name == QN_PUBSUB) {
87    HandlePubsubIqGetResponse(stanza);
88  }
89
90  return STATE_RESPONSE;
91}
92
93// Registers a function pointer to be called when the value of the pubsub
94// node changes.
95// Note that this does not actually change the XMPP pubsub
96// subscription. All publish events are always received by everyone in the
97// MUC. This function just controls whether the handle function will get
98// called when the event is received.
99bool PubsubTask::SubscribeToNode(const std::string& pubsub_node,
100                                 NodeHandler handler) {
101  subscribed_nodes_[pubsub_node] = handler;
102  rtc::scoped_ptr<buzz::XmlElement> get_iq_request(
103      MakeIq(buzz::STR_GET, pubsub_node_jid_, task_id()));
104  if (!get_iq_request) {
105    return false;
106  }
107  buzz::XmlElement* pubsub_element = new buzz::XmlElement(QN_PUBSUB, true);
108  buzz::XmlElement* items_element = new buzz::XmlElement(QN_PUBSUB_ITEMS, true);
109
110  items_element->AddAttr(buzz::QN_NODE, pubsub_node);
111  pubsub_element->AddElement(items_element);
112  get_iq_request->AddElement(pubsub_element);
113
114  if (SendStanza(get_iq_request.get()) != buzz::XMPP_RETURN_OK) {
115    return false;
116  }
117
118  return true;
119}
120
121void PubsubTask::UnsubscribeFromNode(const std::string& pubsub_node) {
122  subscribed_nodes_.erase(pubsub_node);
123}
124
125void PubsubTask::OnPubsubError(const buzz::XmlElement* error_stanza) {
126}
127
128// Checks for a pubsub event message like the following:
129//
130//  <message from="muvc-private-chat-some-id@groupchat.google.com"
131//   to="john@site.com/gcomm582B14C9">
132//    <event xmlns:"http://jabber.org/protocol/pubsub#event">
133//      <items node="node-name">
134//        <item id="some-id">
135//          <payload/>
136//        </item>
137//      </items>
138//    </event>
139//  </message>
140//
141// It also checks for retraction event messages like the following:
142//
143//  <message from="muvc-private-chat-some-id@groupchat.google.com"
144//   to="john@site.com/gcomm582B14C9">
145//    <event xmlns:"http://jabber.org/protocol/pubsub#event">
146//      <items node="node-name">
147//        <retract id="some-id"/>
148//      </items>
149//    </event>
150//  </message>
151void PubsubTask::HandlePubsubEventMessage(
152    const buzz::XmlElement* pubsub_event) {
153  ASSERT(pubsub_event->Name() == QN_PUBSUB_EVENT);
154  for (const buzz::XmlChild* child = pubsub_event->FirstChild();
155       child != NULL;
156       child = child->NextChild()) {
157    const buzz::XmlElement* child_element = child->AsElement();
158    const buzz::QName& child_name(child_element->Name());
159    if (child_name == QN_PUBSUB_EVENT_ITEMS) {
160      HandlePubsubItems(child_element);
161    }
162  }
163}
164
165// Checks for a response to an pubsub IQ get like the following:
166//
167//  <iq from="muvc-private-chat-some-id@groupchat.google.com"
168//   to="john@site.com/gcomm582B14C9"
169//   type="result">
170//    <pubsub xmlns:"http://jabber.org/protocol/pubsub">
171//      <items node="node-name">
172//        <item id="some-id">
173//          <payload/>
174//        </item>
175//      </items>
176//    </event>
177//  </message>
178void PubsubTask::HandlePubsubIqGetResponse(
179    const buzz::XmlElement* pubsub_iq_response) {
180  ASSERT(pubsub_iq_response->Name() == QN_PUBSUB);
181  for (const buzz::XmlChild* child = pubsub_iq_response->FirstChild();
182       child != NULL;
183       child = child->NextChild()) {
184    const buzz::XmlElement* child_element = child->AsElement();
185    const buzz::QName& child_name(child_element->Name());
186    if (child_name == QN_PUBSUB_ITEMS) {
187      HandlePubsubItems(child_element);
188    }
189  }
190}
191
192// Calls registered handlers in response to pubsub event or response to
193// IQ pubsub get.
194// 'items' is the child of a pubsub#event:event node or pubsub:pubsub node.
195void PubsubTask::HandlePubsubItems(const buzz::XmlElement* items) {
196  ASSERT(items->HasAttr(QN_NODE));
197  const std::string& node_name(items->Attr(QN_NODE));
198  NodeSubscriptions::iterator iter = subscribed_nodes_.find(node_name);
199  if (iter != subscribed_nodes_.end()) {
200    NodeHandler handler = iter->second;
201    const buzz::XmlElement* item = items->FirstElement();
202    while (item != NULL) {
203      const buzz::QName& item_name(item->Name());
204      if (item_name != QN_PUBSUB_EVENT_ITEM &&
205          item_name != QN_PUBSUB_EVENT_RETRACT &&
206          item_name != QN_PUBSUB_ITEM) {
207        continue;
208      }
209
210      (this->*handler)(item);
211      item = item->NextElement();
212    }
213    return;
214  }
215}
216
217}
218