1/*
2 * libjingle
3 * Copyright 2013 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/app/webrtc/sctputils.h"
29
30#include "webrtc/base/buffer.h"
31#include "webrtc/base/bytebuffer.h"
32#include "webrtc/base/logging.h"
33
34namespace webrtc {
35
36// Format defined at
37// http://tools.ietf.org/html/draft-ietf-rtcweb-data-protocol-01#section
38
39static const uint8_t DATA_CHANNEL_OPEN_MESSAGE_TYPE = 0x03;
40static const uint8_t DATA_CHANNEL_OPEN_ACK_MESSAGE_TYPE = 0x02;
41
42enum DataChannelOpenMessageChannelType {
43  DCOMCT_ORDERED_RELIABLE = 0x00,
44  DCOMCT_ORDERED_PARTIAL_RTXS = 0x01,
45  DCOMCT_ORDERED_PARTIAL_TIME = 0x02,
46  DCOMCT_UNORDERED_RELIABLE = 0x80,
47  DCOMCT_UNORDERED_PARTIAL_RTXS = 0x81,
48  DCOMCT_UNORDERED_PARTIAL_TIME = 0x82,
49};
50
51bool IsOpenMessage(const rtc::Buffer& payload) {
52  // Format defined at
53  // http://tools.ietf.org/html/draft-jesup-rtcweb-data-protocol-04
54
55  rtc::ByteBuffer buffer(payload);
56  uint8_t message_type;
57  if (!buffer.ReadUInt8(&message_type)) {
58    LOG(LS_WARNING) << "Could not read OPEN message type.";
59    return false;
60  }
61  return message_type == DATA_CHANNEL_OPEN_MESSAGE_TYPE;
62}
63
64bool ParseDataChannelOpenMessage(const rtc::Buffer& payload,
65                                 std::string* label,
66                                 DataChannelInit* config) {
67  // Format defined at
68  // http://tools.ietf.org/html/draft-jesup-rtcweb-data-protocol-04
69
70  rtc::ByteBuffer buffer(payload);
71  uint8_t message_type;
72  if (!buffer.ReadUInt8(&message_type)) {
73    LOG(LS_WARNING) << "Could not read OPEN message type.";
74    return false;
75  }
76  if (message_type != DATA_CHANNEL_OPEN_MESSAGE_TYPE) {
77    LOG(LS_WARNING) << "Data Channel OPEN message of unexpected type: "
78                    << message_type;
79    return false;
80  }
81
82  uint8_t channel_type;
83  if (!buffer.ReadUInt8(&channel_type)) {
84    LOG(LS_WARNING) << "Could not read OPEN message channel type.";
85    return false;
86  }
87
88  uint16_t priority;
89  if (!buffer.ReadUInt16(&priority)) {
90    LOG(LS_WARNING) << "Could not read OPEN message reliabilility prioirty.";
91    return false;
92  }
93  uint32_t reliability_param;
94  if (!buffer.ReadUInt32(&reliability_param)) {
95    LOG(LS_WARNING) << "Could not read OPEN message reliabilility param.";
96    return false;
97  }
98  uint16_t label_length;
99  if (!buffer.ReadUInt16(&label_length)) {
100    LOG(LS_WARNING) << "Could not read OPEN message label length.";
101    return false;
102  }
103  uint16_t protocol_length;
104  if (!buffer.ReadUInt16(&protocol_length)) {
105    LOG(LS_WARNING) << "Could not read OPEN message protocol length.";
106    return false;
107  }
108  if (!buffer.ReadString(label, (size_t) label_length)) {
109    LOG(LS_WARNING) << "Could not read OPEN message label";
110    return false;
111  }
112  if (!buffer.ReadString(&config->protocol, protocol_length)) {
113    LOG(LS_WARNING) << "Could not read OPEN message protocol.";
114    return false;
115  }
116
117  config->ordered = true;
118  switch (channel_type) {
119    case DCOMCT_UNORDERED_RELIABLE:
120    case DCOMCT_UNORDERED_PARTIAL_RTXS:
121    case DCOMCT_UNORDERED_PARTIAL_TIME:
122      config->ordered = false;
123  }
124
125  config->maxRetransmits = -1;
126  config->maxRetransmitTime = -1;
127  switch (channel_type) {
128    case DCOMCT_ORDERED_PARTIAL_RTXS:
129    case DCOMCT_UNORDERED_PARTIAL_RTXS:
130      config->maxRetransmits = reliability_param;
131      break;
132    case DCOMCT_ORDERED_PARTIAL_TIME:
133    case DCOMCT_UNORDERED_PARTIAL_TIME:
134      config->maxRetransmitTime = reliability_param;
135      break;
136  }
137  return true;
138}
139
140bool ParseDataChannelOpenAckMessage(const rtc::Buffer& payload) {
141  rtc::ByteBuffer buffer(payload);
142  uint8_t message_type;
143  if (!buffer.ReadUInt8(&message_type)) {
144    LOG(LS_WARNING) << "Could not read OPEN_ACK message type.";
145    return false;
146  }
147  if (message_type != DATA_CHANNEL_OPEN_ACK_MESSAGE_TYPE) {
148    LOG(LS_WARNING) << "Data Channel OPEN_ACK message of unexpected type: "
149                    << message_type;
150    return false;
151  }
152  return true;
153}
154
155bool WriteDataChannelOpenMessage(const std::string& label,
156                                 const DataChannelInit& config,
157                                 rtc::Buffer* payload) {
158  // Format defined at
159  // http://tools.ietf.org/html/draft-ietf-rtcweb-data-protocol-00#section-6.1
160  uint8_t channel_type = 0;
161  uint32_t reliability_param = 0;
162  uint16_t priority = 0;
163  if (config.ordered) {
164    if (config.maxRetransmits > -1) {
165      channel_type = DCOMCT_ORDERED_PARTIAL_RTXS;
166      reliability_param = config.maxRetransmits;
167    } else if (config.maxRetransmitTime > -1) {
168      channel_type = DCOMCT_ORDERED_PARTIAL_TIME;
169      reliability_param = config.maxRetransmitTime;
170    } else {
171      channel_type = DCOMCT_ORDERED_RELIABLE;
172    }
173  } else {
174    if (config.maxRetransmits > -1) {
175      channel_type = DCOMCT_UNORDERED_PARTIAL_RTXS;
176      reliability_param = config.maxRetransmits;
177    } else if (config.maxRetransmitTime > -1) {
178      channel_type = DCOMCT_UNORDERED_PARTIAL_TIME;
179      reliability_param = config.maxRetransmitTime;
180    } else {
181      channel_type = DCOMCT_UNORDERED_RELIABLE;
182    }
183  }
184
185  rtc::ByteBuffer buffer(
186      NULL, 20 + label.length() + config.protocol.length(),
187      rtc::ByteBuffer::ORDER_NETWORK);
188  buffer.WriteUInt8(DATA_CHANNEL_OPEN_MESSAGE_TYPE);
189  buffer.WriteUInt8(channel_type);
190  buffer.WriteUInt16(priority);
191  buffer.WriteUInt32(reliability_param);
192  buffer.WriteUInt16(static_cast<uint16_t>(label.length()));
193  buffer.WriteUInt16(static_cast<uint16_t>(config.protocol.length()));
194  buffer.WriteString(label);
195  buffer.WriteString(config.protocol);
196  payload->SetData(buffer.Data(), buffer.Length());
197  return true;
198}
199
200void WriteDataChannelOpenAckMessage(rtc::Buffer* payload) {
201  rtc::ByteBuffer buffer(rtc::ByteBuffer::ORDER_NETWORK);
202  buffer.WriteUInt8(DATA_CHANNEL_OPEN_ACK_MESSAGE_TYPE);
203  payload->SetData(buffer.Data(), buffer.Length());
204}
205}  // namespace webrtc
206