234 lines
7.4 KiB
C++
234 lines
7.4 KiB
C++
/*
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* Copyright 2013 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "pc/sctp_utils.h"
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#include <stddef.h>
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#include <cstdint>
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#include "absl/types/optional.h"
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#include "api/priority.h"
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#include "rtc_base/byte_buffer.h"
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#include "rtc_base/copy_on_write_buffer.h"
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#include "rtc_base/logging.h"
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namespace webrtc {
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// Format defined at
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// http://tools.ietf.org/html/draft-ietf-rtcweb-data-protocol-01#section
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static const uint8_t DATA_CHANNEL_OPEN_MESSAGE_TYPE = 0x03;
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static const uint8_t DATA_CHANNEL_OPEN_ACK_MESSAGE_TYPE = 0x02;
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enum DataChannelOpenMessageChannelType {
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DCOMCT_ORDERED_RELIABLE = 0x00,
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DCOMCT_ORDERED_PARTIAL_RTXS = 0x01,
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DCOMCT_ORDERED_PARTIAL_TIME = 0x02,
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DCOMCT_UNORDERED_RELIABLE = 0x80,
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DCOMCT_UNORDERED_PARTIAL_RTXS = 0x81,
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DCOMCT_UNORDERED_PARTIAL_TIME = 0x82,
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};
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// Values of priority in the DC open protocol message.
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// These are compared against an integer, so are enum, not enum class.
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enum DataChannelPriority {
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DCO_PRIORITY_VERY_LOW = 128,
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DCO_PRIORITY_LOW = 256,
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DCO_PRIORITY_MEDIUM = 512,
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DCO_PRIORITY_HIGH = 1024,
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};
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bool IsOpenMessage(const rtc::CopyOnWriteBuffer& payload) {
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// Format defined at
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// http://tools.ietf.org/html/draft-jesup-rtcweb-data-protocol-04
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if (payload.size() < 1) {
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RTC_LOG(LS_WARNING) << "Could not read OPEN message type.";
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return false;
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}
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uint8_t message_type = payload[0];
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return message_type == DATA_CHANNEL_OPEN_MESSAGE_TYPE;
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}
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bool ParseDataChannelOpenMessage(const rtc::CopyOnWriteBuffer& payload,
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std::string* label,
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DataChannelInit* config) {
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// Format defined at
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// http://tools.ietf.org/html/draft-jesup-rtcweb-data-protocol-04
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rtc::ByteBufferReader buffer(payload.data<char>(), payload.size());
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uint8_t message_type;
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if (!buffer.ReadUInt8(&message_type)) {
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RTC_LOG(LS_WARNING) << "Could not read OPEN message type.";
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return false;
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}
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if (message_type != DATA_CHANNEL_OPEN_MESSAGE_TYPE) {
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RTC_LOG(LS_WARNING) << "Data Channel OPEN message of unexpected type: "
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<< message_type;
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return false;
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}
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uint8_t channel_type;
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if (!buffer.ReadUInt8(&channel_type)) {
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RTC_LOG(LS_WARNING) << "Could not read OPEN message channel type.";
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return false;
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}
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uint16_t priority;
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if (!buffer.ReadUInt16(&priority)) {
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RTC_LOG(LS_WARNING)
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<< "Could not read OPEN message reliabilility prioirty.";
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return false;
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}
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// Parse priority as defined in
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// https://w3c.github.io/webrtc-priority/#rtcdatachannel-processing-steps
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if (priority <= DCO_PRIORITY_VERY_LOW) {
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config->priority = Priority::kVeryLow;
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} else if (priority <= DCO_PRIORITY_LOW) {
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config->priority = Priority::kLow;
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} else if (priority <= DCO_PRIORITY_MEDIUM) {
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config->priority = Priority::kMedium;
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} else {
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config->priority = Priority::kHigh;
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}
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uint32_t reliability_param;
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if (!buffer.ReadUInt32(&reliability_param)) {
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RTC_LOG(LS_WARNING) << "Could not read OPEN message reliabilility param.";
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return false;
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}
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uint16_t label_length;
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if (!buffer.ReadUInt16(&label_length)) {
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RTC_LOG(LS_WARNING) << "Could not read OPEN message label length.";
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return false;
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}
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uint16_t protocol_length;
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if (!buffer.ReadUInt16(&protocol_length)) {
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RTC_LOG(LS_WARNING) << "Could not read OPEN message protocol length.";
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return false;
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}
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if (!buffer.ReadString(label, (size_t)label_length)) {
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RTC_LOG(LS_WARNING) << "Could not read OPEN message label";
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return false;
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}
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if (!buffer.ReadString(&config->protocol, protocol_length)) {
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RTC_LOG(LS_WARNING) << "Could not read OPEN message protocol.";
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return false;
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}
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config->ordered = true;
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switch (channel_type) {
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case DCOMCT_UNORDERED_RELIABLE:
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case DCOMCT_UNORDERED_PARTIAL_RTXS:
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case DCOMCT_UNORDERED_PARTIAL_TIME:
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config->ordered = false;
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}
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config->maxRetransmits = absl::nullopt;
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config->maxRetransmitTime = absl::nullopt;
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switch (channel_type) {
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case DCOMCT_ORDERED_PARTIAL_RTXS:
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case DCOMCT_UNORDERED_PARTIAL_RTXS:
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config->maxRetransmits = reliability_param;
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break;
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case DCOMCT_ORDERED_PARTIAL_TIME:
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case DCOMCT_UNORDERED_PARTIAL_TIME:
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config->maxRetransmitTime = reliability_param;
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break;
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}
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return true;
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}
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bool ParseDataChannelOpenAckMessage(const rtc::CopyOnWriteBuffer& payload) {
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if (payload.size() < 1) {
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RTC_LOG(LS_WARNING) << "Could not read OPEN_ACK message type.";
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return false;
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}
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uint8_t message_type = payload[0];
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if (message_type != DATA_CHANNEL_OPEN_ACK_MESSAGE_TYPE) {
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RTC_LOG(LS_WARNING) << "Data Channel OPEN_ACK message of unexpected type: "
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<< message_type;
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return false;
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}
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return true;
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}
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bool WriteDataChannelOpenMessage(const std::string& label,
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const DataChannelInit& config,
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rtc::CopyOnWriteBuffer* payload) {
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// Format defined at
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// http://tools.ietf.org/html/draft-ietf-rtcweb-data-protocol-09#section-5.1
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uint8_t channel_type = 0;
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uint32_t reliability_param = 0;
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uint16_t priority = 0;
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// Set priority according to
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// https://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-12#section-6.4
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if (config.priority) {
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switch (*config.priority) {
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case Priority::kVeryLow:
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priority = DCO_PRIORITY_VERY_LOW;
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break;
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case Priority::kLow:
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priority = DCO_PRIORITY_LOW;
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break;
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case Priority::kMedium:
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priority = DCO_PRIORITY_MEDIUM;
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break;
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case Priority::kHigh:
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priority = DCO_PRIORITY_HIGH;
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break;
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}
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}
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if (config.ordered) {
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if (config.maxRetransmits) {
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channel_type = DCOMCT_ORDERED_PARTIAL_RTXS;
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reliability_param = *config.maxRetransmits;
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} else if (config.maxRetransmitTime) {
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channel_type = DCOMCT_ORDERED_PARTIAL_TIME;
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reliability_param = *config.maxRetransmitTime;
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} else {
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channel_type = DCOMCT_ORDERED_RELIABLE;
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}
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} else {
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if (config.maxRetransmits) {
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channel_type = DCOMCT_UNORDERED_PARTIAL_RTXS;
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reliability_param = *config.maxRetransmits;
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} else if (config.maxRetransmitTime) {
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channel_type = DCOMCT_UNORDERED_PARTIAL_TIME;
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reliability_param = *config.maxRetransmitTime;
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} else {
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channel_type = DCOMCT_UNORDERED_RELIABLE;
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}
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}
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rtc::ByteBufferWriter buffer(NULL,
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20 + label.length() + config.protocol.length());
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// TODO(tommi): Add error handling and check resulting length.
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buffer.WriteUInt8(DATA_CHANNEL_OPEN_MESSAGE_TYPE);
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buffer.WriteUInt8(channel_type);
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buffer.WriteUInt16(priority);
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buffer.WriteUInt32(reliability_param);
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buffer.WriteUInt16(static_cast<uint16_t>(label.length()));
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buffer.WriteUInt16(static_cast<uint16_t>(config.protocol.length()));
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buffer.WriteString(label);
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buffer.WriteString(config.protocol);
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payload->SetData(buffer.Data(), buffer.Length());
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return true;
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}
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void WriteDataChannelOpenAckMessage(rtc::CopyOnWriteBuffer* payload) {
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uint8_t data = DATA_CHANNEL_OPEN_ACK_MESSAGE_TYPE;
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payload->SetData(&data, sizeof(data));
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}
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} // namespace webrtc
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