1 // Copyright 2015 The Weave Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "src/notification/xmpp_iq_stanza_handler.h"
6
7 #include <base/bind.h>
8 #include <base/strings/string_number_conversions.h>
9 #include <base/strings/stringprintf.h>
10 #include <weave/provider/task_runner.h>
11
12 #include "src/notification/xml_node.h"
13 #include "src/notification/xmpp_channel.h"
14
15 namespace weave {
16
17 namespace {
18
19 // Default timeout for <iq> requests to the server. If the response hasn't been
20 // received within this time interval, the request is considered as failed.
21 const int kTimeoutIntervalSeconds = 30;
22
23 // Builds an XML stanza that looks like this:
24 // <iq id='${id}' type='${type}' from='${from}' to='${to}'>$body</iq>
25 // where 'to' and 'from' are optional attributes.
BuildIqStanza(const std::string & id,const std::string & type,const std::string & to,const std::string & from,const std::string & body)26 std::string BuildIqStanza(const std::string& id,
27 const std::string& type,
28 const std::string& to,
29 const std::string& from,
30 const std::string& body) {
31 std::string to_attr;
32 if (!to.empty()) {
33 CHECK_EQ(std::string::npos, to.find_first_of("<'>"))
34 << "Destination address contains invalid XML characters";
35 base::StringAppendF(&to_attr, " to='%s'", to.c_str());
36 }
37 std::string from_attr;
38 if (!from.empty()) {
39 CHECK_EQ(std::string::npos, from.find_first_of("<'>"))
40 << "Source address contains invalid XML characters";
41 base::StringAppendF(&from_attr, " from='%s'", from.c_str());
42 }
43 return base::StringPrintf("<iq id='%s' type='%s'%s%s>%s</iq>", id.c_str(),
44 type.c_str(), from_attr.c_str(), to_attr.c_str(),
45 body.c_str());
46 }
47
48 } // anonymous namespace
49
IqStanzaHandler(XmppChannelInterface * xmpp_channel,provider::TaskRunner * task_runner)50 IqStanzaHandler::IqStanzaHandler(XmppChannelInterface* xmpp_channel,
51 provider::TaskRunner* task_runner)
52 : xmpp_channel_{xmpp_channel}, task_runner_{task_runner} {}
53
SendRequest(const std::string & type,const std::string & from,const std::string & to,const std::string & body,const ResponseCallback & response_callback,const TimeoutCallback & timeout_callback)54 void IqStanzaHandler::SendRequest(const std::string& type,
55 const std::string& from,
56 const std::string& to,
57 const std::string& body,
58 const ResponseCallback& response_callback,
59 const TimeoutCallback& timeout_callback) {
60 return SendRequestWithCustomTimeout(
61 type, from, to, body,
62 base::TimeDelta::FromSeconds(kTimeoutIntervalSeconds), response_callback,
63 timeout_callback);
64 }
65
SendRequestWithCustomTimeout(const std::string & type,const std::string & from,const std::string & to,const std::string & body,base::TimeDelta timeout,const ResponseCallback & response_callback,const TimeoutCallback & timeout_callback)66 void IqStanzaHandler::SendRequestWithCustomTimeout(
67 const std::string& type,
68 const std::string& from,
69 const std::string& to,
70 const std::string& body,
71 base::TimeDelta timeout,
72 const ResponseCallback& response_callback,
73 const TimeoutCallback& timeout_callback) {
74 // Remember the response callback to call later.
75 requests_.insert(std::make_pair(++last_request_id_, response_callback));
76 // Schedule a time-out callback for this request.
77 if (timeout < base::TimeDelta::Max()) {
78 task_runner_->PostDelayedTask(
79 FROM_HERE,
80 base::Bind(&IqStanzaHandler::OnTimeOut, weak_ptr_factory_.GetWeakPtr(),
81 last_request_id_, timeout_callback),
82 timeout);
83 }
84
85 std::string message =
86 BuildIqStanza(std::to_string(last_request_id_), type, to, from, body);
87 xmpp_channel_->SendMessage(message);
88 }
89
HandleIqStanza(std::unique_ptr<XmlNode> stanza)90 bool IqStanzaHandler::HandleIqStanza(std::unique_ptr<XmlNode> stanza) {
91 std::string type;
92 if (!stanza->GetAttribute("type", &type)) {
93 LOG(ERROR) << "IQ stanza missing 'type' attribute";
94 return false;
95 }
96
97 std::string id_str;
98 if (!stanza->GetAttribute("id", &id_str)) {
99 LOG(ERROR) << "IQ stanza missing 'id' attribute";
100 return false;
101 }
102
103 if (type == "result" || type == "error") {
104 // These are response stanzas from the server.
105 // Find the corresponding request.
106 RequestId id;
107 if (!base::StringToInt(id_str, &id)) {
108 LOG(ERROR) << "IQ stanza's 'id' attribute is invalid";
109 return false;
110 }
111 auto p = requests_.find(id);
112 if (p != requests_.end()) {
113 task_runner_->PostDelayedTask(
114 FROM_HERE, base::Bind(p->second, base::Passed(std::move(stanza))),
115 {});
116 requests_.erase(p);
117 }
118 } else {
119 // We do not support server-initiated IQ requests ("set" / "get" / "query").
120 // So just reply with "not implemented" error (and swap "to"/"from" attrs).
121 std::string error_body =
122 "<error type='modify'>"
123 "<feature-not-implemented xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>"
124 "</error>";
125 std::string message =
126 BuildIqStanza(id_str, "error", stanza->GetAttributeOrEmpty("from"),
127 stanza->GetAttributeOrEmpty("to"), error_body);
128 xmpp_channel_->SendMessage(message);
129 }
130 return true;
131 }
132
OnTimeOut(RequestId id,const TimeoutCallback & timeout_callback)133 void IqStanzaHandler::OnTimeOut(RequestId id,
134 const TimeoutCallback& timeout_callback) {
135 // Request has not been processed yes, so a real timeout occurred.
136 if (requests_.erase(id) > 0)
137 timeout_callback.Run();
138 }
139
140 } // namespace weave
141