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
|
// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "chrome/browser/ash/net/network_diagnostics/https_firewall_routine.h"
#include <algorithm>
#include <string>
#include <utility>
#include <vector>
#include "base/functional/bind.h"
#include "chrome/browser/ash/net/network_diagnostics/network_diagnostics_util.h"
#include "chrome/browser/profiles/profile.h"
#include "content/public/browser/storage_partition.h"
#include "services/network/public/mojom/network_context.mojom.h"
namespace ash {
namespace network_diagnostics {
namespace {
namespace mojom = ::chromeos::network_diagnostics::mojom;
// Https port number.
constexpr int kHttpsPort = 443;
// Https scheme.
constexpr char kHttpsScheme[] = "https://";
// Effetively, the number of random hosts to query.
// total hosts queried by this routine = random hosts + fixed hosts, where
// information about fixed hosts is found in network_diagnostics_util.cc.
constexpr int kTotalAdditionalHostsToQuery = 3;
// The length of a random eight letter prefix obtained by the characters from
// |kPossibleChars|.
constexpr int kHostPrefixLength = 8;
// The threshold describing the number of DNS resolution failures permitted.
// E.g. If 10 host resolution attempts are made, any more than two DNS failures
// would result in a problem.
constexpr double kDnsResolutionFailureRateThreshold = 0.2;
// The threshold describing number of TLS probe failures permitted. E.g. If 10
// TLS probes are attempted, any more than two failures would result in a
// problem. This number does not take into account the number of TLS probes that
// failed due to unsuccessful DNS resolution.
constexpr double kTlsProbeFailureRateThreshold = 0.2;
// For an explanation of error codes, see "net/base/net_error_list.h".
constexpr int kRetryResponseCodes[] = {net::ERR_TIMED_OUT,
net::ERR_DNS_TIMED_OUT};
} // namespace
const int kTotalNumRetries = 3;
HttpsFirewallRoutine::HttpsFirewallRoutine(mojom::RoutineCallSource source)
: NetworkDiagnosticsRoutine(source),
num_retries_(kTotalNumRetries),
tls_prober_getter_callback_(base::BindRepeating(
&HttpsFirewallRoutine::CreateAndExecuteTlsProber)) {
std::vector<std::string> url_strings =
util::GetRandomAndFixedHostsWithSchemeAndPort(
kTotalAdditionalHostsToQuery, kHostPrefixLength, kHttpsScheme,
kHttpsPort);
for (const auto& url_string : url_strings) {
urls_to_query_.push_back(GURL(url_string));
}
num_urls_to_query_ = urls_to_query_.size();
}
HttpsFirewallRoutine::~HttpsFirewallRoutine() = default;
mojom::RoutineType HttpsFirewallRoutine::Type() {
return mojom::RoutineType::kHttpsFirewall;
}
void HttpsFirewallRoutine::Run() {
ProbeNextUrl();
}
void HttpsFirewallRoutine::AnalyzeResultsAndExecuteCallback() {
// There should at least `kTotalAdditionalHostsToQuery` (=3) URLs to query.
DCHECK(num_urls_to_query_);
double dns_resolution_failure_rate =
static_cast<double>(dns_resolution_failures_) /
static_cast<double>(num_urls_to_query_);
if (dns_resolution_failure_rate > kDnsResolutionFailureRateThreshold) {
set_verdict(mojom::RoutineVerdict::kProblem);
problems_.push_back(
mojom::HttpsFirewallProblem::kHighDnsResolutionFailureRate);
} else {
// When `dns_resolution_failure_rate` is below the threshold, there must be
// probes that is not "DNS failure".
DCHECK(num_no_dns_failure_tls_probes_attempted_);
double tls_probe_failure_rate =
static_cast<double>(tls_probe_failures_) /
static_cast<double>(num_no_dns_failure_tls_probes_attempted_);
if (tls_probe_failure_rate <= kTlsProbeFailureRateThreshold) {
set_verdict(mojom::RoutineVerdict::kNoProblem);
} else if (tls_probe_failures_ ==
num_no_dns_failure_tls_probes_attempted_) {
set_verdict(mojom::RoutineVerdict::kProblem);
problems_.push_back(mojom::HttpsFirewallProblem::kFirewallDetected);
} else {
// It cannot be conclusively determined whether a firewall exists;
// however, since reaching this case means tls_probe_failure_rate >
// kTlsProbeFailureRateThreshold, a firewall could potentially
// exist.
set_verdict(mojom::RoutineVerdict::kProblem);
problems_.push_back(mojom::HttpsFirewallProblem::kPotentialFirewall);
}
}
set_problems(mojom::RoutineProblems::NewHttpsFirewallProblems(problems_));
ExecuteCallback();
}
void HttpsFirewallRoutine::ProbeNextUrl() {
DCHECK(urls_to_query_.size() > 0);
auto url = urls_to_query_.back();
urls_to_query_.pop_back();
AttemptProbe(url);
}
void HttpsFirewallRoutine::AttemptProbe(const GURL& url) {
// Store the instance of TlsProber.
tls_prober_ = tls_prober_getter_callback_.Run(
base::BindRepeating(&HttpsFirewallRoutine::GetNetworkContext),
net::HostPortPair::FromURL(url),
/*negotiate_tls=*/true,
base::BindOnce(&HttpsFirewallRoutine::OnProbeComplete, weak_ptr(), url));
}
void HttpsFirewallRoutine::OnProbeComplete(
const GURL& url,
int result,
TlsProber::ProbeExitEnum probe_exit_enum) {
if (probe_exit_enum == TlsProber::ProbeExitEnum::kDnsFailure) {
dns_resolution_failures_++;
} else {
const auto* iter = std::ranges::find(kRetryResponseCodes, result);
if (iter != std::end(kRetryResponseCodes) && num_retries_ > 0) {
num_retries_--;
AttemptProbe(url);
return;
}
if (result < 0) {
tls_probe_failures_++;
}
num_no_dns_failure_tls_probes_attempted_++;
}
if (urls_to_query_.size() == 0) {
AnalyzeResultsAndExecuteCallback();
return;
}
ProbeNextUrl();
}
network::mojom::NetworkContext* HttpsFirewallRoutine::GetNetworkContext() {
Profile* profile = util::GetUserProfile();
DCHECK(profile);
return profile->GetDefaultStoragePartition()->GetNetworkContext();
}
std::unique_ptr<TlsProber> HttpsFirewallRoutine::CreateAndExecuteTlsProber(
network::NetworkContextGetter network_context_getter,
net::HostPortPair host_port_pair,
bool negotiate_tls,
TlsProber::TlsProbeCompleteCallback callback) {
return std::make_unique<TlsProber>(std::move(network_context_getter),
host_port_pair, negotiate_tls,
std::move(callback));
}
} // namespace network_diagnostics
} // namespace ash
|
