1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
//
// Copyright (C) 2013 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#include "shill/traffic_monitor.h"
#include <base/bind.h>
#include <base/strings/stringprintf.h>
#include <netinet/in.h>
#include "shill/device.h"
#include "shill/device_info.h"
#include "shill/event_dispatcher.h"
#include "shill/logging.h"
#include "shill/socket_info_reader.h"
using base::StringPrintf;
using std::string;
using std::vector;
namespace shill {
namespace Logging {
static auto kModuleLogScope = ScopeLogger::kLink;
static string ObjectID(Device* d) { return d->link_name(); }
}
// static
const uint16_t TrafficMonitor::kDnsPort = 53;
const int64_t TrafficMonitor::kDnsTimedOutThresholdSeconds = 15;
const int TrafficMonitor::kMinimumFailedSamplesToTrigger = 2;
const int64_t TrafficMonitor::kSamplingIntervalMilliseconds = 5000;
TrafficMonitor::TrafficMonitor(const DeviceRefPtr& device,
EventDispatcher* dispatcher)
: device_(device),
dispatcher_(dispatcher),
socket_info_reader_(new SocketInfoReader),
accummulated_congested_tx_queues_samples_(0),
connection_info_reader_(new ConnectionInfoReader),
accummulated_dns_failures_samples_(0) {
}
TrafficMonitor::~TrafficMonitor() {
Stop();
}
void TrafficMonitor::Start() {
SLOG(device_.get(), 2) << __func__;
Stop();
sample_traffic_callback_.Reset(base::Bind(&TrafficMonitor::SampleTraffic,
base::Unretained(this)));
dispatcher_->PostDelayedTask(sample_traffic_callback_.callback(),
kSamplingIntervalMilliseconds);
}
void TrafficMonitor::Stop() {
SLOG(device_.get(), 2) << __func__;
sample_traffic_callback_.Cancel();
ResetCongestedTxQueuesStats();
ResetDnsFailingStats();
}
void TrafficMonitor::ResetCongestedTxQueuesStats() {
accummulated_congested_tx_queues_samples_ = 0;
}
void TrafficMonitor::ResetCongestedTxQueuesStatsWithLogging() {
SLOG(device_.get(), 2) << __func__ << ": Tx-queues decongested";
ResetCongestedTxQueuesStats();
}
void TrafficMonitor::BuildIPPortToTxQueueLength(
const vector<SocketInfo>& socket_infos,
IPPortToTxQueueLengthMap* tx_queue_lengths) {
SLOG(device_.get(), 3) << __func__;
string device_ip_address = device_->ipconfig()->properties().address;
for (const auto& info : socket_infos) {
SLOG(device_.get(), 4) << "SocketInfo(IP="
<< info.local_ip_address().ToString()
<< ", TX=" << info.transmit_queue_value()
<< ", State=" << info.connection_state()
<< ", TimerState=" << info.timer_state();
if (info.local_ip_address().ToString() != device_ip_address ||
info.transmit_queue_value() == 0 ||
info.connection_state() != SocketInfo::kConnectionStateEstablished ||
(info.timer_state() != SocketInfo::kTimerStateRetransmitTimerPending &&
info.timer_state() !=
SocketInfo::kTimerStateZeroWindowProbeTimerPending)) {
SLOG(device_.get(), 4) << "Connection Filtered.";
continue;
}
SLOG(device_.get(), 3) << "Monitoring connection: TX="
<< info.transmit_queue_value()
<< " TimerState=" << info.timer_state();
string local_ip_port =
StringPrintf("%s:%d",
info.local_ip_address().ToString().c_str(),
info.local_port());
(*tx_queue_lengths)[local_ip_port] = info.transmit_queue_value();
}
}
bool TrafficMonitor::IsCongestedTxQueues() {
SLOG(device_.get(), 4) << __func__;
vector<SocketInfo> socket_infos;
if (!socket_info_reader_->LoadTcpSocketInfo(&socket_infos) ||
socket_infos.empty()) {
SLOG(device_.get(), 3) << __func__ << ": Empty socket info";
ResetCongestedTxQueuesStatsWithLogging();
return false;
}
bool congested_tx_queues = true;
IPPortToTxQueueLengthMap curr_tx_queue_lengths;
BuildIPPortToTxQueueLength(socket_infos, &curr_tx_queue_lengths);
if (curr_tx_queue_lengths.empty()) {
SLOG(device_.get(), 3) << __func__ << ": No interesting socket info";
ResetCongestedTxQueuesStatsWithLogging();
} else {
for (const auto& length_entry : old_tx_queue_lengths_) {
IPPortToTxQueueLengthMap::iterator curr_tx_queue_it =
curr_tx_queue_lengths.find(length_entry.first);
if (curr_tx_queue_it == curr_tx_queue_lengths.end() ||
curr_tx_queue_it->second < length_entry.second) {
congested_tx_queues = false;
// TODO(armansito): If we had a false positive earlier, we may
// want to correct it here by invoking a "connection back to normal
// callback", so that the OutOfCredits property can be set to
// false.
break;
}
}
if (congested_tx_queues) {
++accummulated_congested_tx_queues_samples_;
SLOG(device_.get(), 2) << __func__
<< ": Congested tx-queues detected ("
<< accummulated_congested_tx_queues_samples_
<< ")";
}
}
old_tx_queue_lengths_ = curr_tx_queue_lengths;
return congested_tx_queues;
}
void TrafficMonitor::ResetDnsFailingStats() {
accummulated_dns_failures_samples_ = 0;
}
void TrafficMonitor::ResetDnsFailingStatsWithLogging() {
SLOG(device_.get(), 2) << __func__ << ": DNS queries restored";
ResetDnsFailingStats();
}
bool TrafficMonitor::IsDnsFailing() {
SLOG(device_.get(), 4) << __func__;
vector<ConnectionInfo> connection_infos;
if (!connection_info_reader_->LoadConnectionInfo(&connection_infos) ||
connection_infos.empty()) {
SLOG(device_.get(), 3) << __func__ << ": Empty connection info";
} else {
// The time-to-expire counter is used to determine when a DNS request
// has timed out. This counter is the number of seconds remaining until
// the entry is removed from the system IP connection tracker. The
// default time is 30 seconds. This is too long of a wait. Instead, we
// want to time out at |kDnsTimedOutThresholdSeconds|. Unfortunately,
// we cannot simply look for entries less than
// |kDnsTimedOutThresholdSeconds| because we will count the entry
// multiple times once its time-to-expire is less than
// |kDnsTimedOutThresholdSeconds|. To ensure that we only count an
// entry once, we look for entries in this time window between
// |kDnsTimedOutThresholdSeconds| and |kDnsTimedOutLowerThresholdSeconds|.
const int64_t kDnsTimedOutLowerThresholdSeconds =
kDnsTimedOutThresholdSeconds - kSamplingIntervalMilliseconds / 1000;
string device_ip_address = device_->ipconfig()->properties().address;
for (const auto& info : connection_infos) {
if (info.protocol() != IPPROTO_UDP ||
info.time_to_expire_seconds() > kDnsTimedOutThresholdSeconds ||
info.time_to_expire_seconds() <= kDnsTimedOutLowerThresholdSeconds ||
!info.is_unreplied() ||
info.original_source_ip_address().ToString() != device_ip_address ||
info.original_destination_port() != kDnsPort)
continue;
++accummulated_dns_failures_samples_;
SLOG(device_.get(), 2) << __func__
<< ": DNS failures detected ("
<< accummulated_dns_failures_samples_ << ")";
return true;
}
}
ResetDnsFailingStatsWithLogging();
return false;
}
void TrafficMonitor::SampleTraffic() {
SLOG(device_.get(), 3) << __func__;
// Schedule the sample callback first, so it is possible for the network
// problem callback to stop the traffic monitor.
dispatcher_->PostDelayedTask(sample_traffic_callback_.callback(),
kSamplingIntervalMilliseconds);
if (IsCongestedTxQueues() &&
accummulated_congested_tx_queues_samples_ ==
kMinimumFailedSamplesToTrigger) {
LOG(WARNING) << "Congested tx queues detected, out-of-credits?";
network_problem_detected_callback_.Run(kNetworkProblemCongestedTxQueue);
} else if (IsDnsFailing() &&
accummulated_dns_failures_samples_ ==
kMinimumFailedSamplesToTrigger) {
LOG(WARNING) << "DNS queries failing, out-of-credits?";
network_problem_detected_callback_.Run(kNetworkProblemDNSFailure);
}
}
} // namespace shill
|
