tdesktop/Telegram/SourceFiles/mtproto/special_config_request.cpp

883 lines
25 KiB
C++

/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.
For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#include "mtproto/special_config_request.h"
#include "mtproto/rsa_public_key.h"
#include "mtproto/dc_options.h"
#include "mtproto/auth_key.h"
#include "base/unixtime.h"
#include "base/openssl_help.h"
#include "base/call_delayed.h"
#include "facades.h"
#include <QtCore/QJsonDocument>
#include <QtCore/QJsonArray>
#include <QtCore/QJsonObject>
extern "C" {
#include <openssl/aes.h>
} // extern "C"
namespace MTP {
namespace {
constexpr auto kSendNextTimeout = crl::time(800);
constexpr auto kMinTimeToLive = 10 * crl::time(1000);
constexpr auto kMaxTimeToLive = 300 * crl::time(1000);
constexpr auto kPublicKey = str_const("\
-----BEGIN RSA PUBLIC KEY-----\n\
MIIBCgKCAQEAyr+18Rex2ohtVy8sroGPBwXD3DOoKCSpjDqYoXgCqB7ioln4eDCF\n\
fOBUlfXUEvM/fnKCpF46VkAftlb4VuPDeQSS/ZxZYEGqHaywlroVnXHIjgqoxiAd\n\
192xRGreuXIaUKmkwlM9JID9WS2jUsTpzQ91L8MEPLJ/4zrBwZua8W5fECwCCh2c\n\
9G5IzzBm+otMS/YKwmR1olzRCyEkyAEjXWqBI9Ftv5eG8m0VkBzOG655WIYdyV0H\n\
fDK/NWcvGqa0w/nriMD6mDjKOryamw0OP9QuYgMN0C9xMW9y8SmP4h92OAWodTYg\n\
Y1hZCxdv6cs5UnW9+PWvS+WIbkh+GaWYxwIDAQAB\n\
-----END RSA PUBLIC KEY-----\
");
constexpr auto kUserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
"AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.90 Safari/537.36";
const auto kRemoteProject = "peak-vista-421";
const auto kFireProject = "reserve-5a846";
const auto kConfigKey = "ipconfig";
const auto kConfigSubKey = "v3";
const auto kApiKey = "AIzaSyC2-kAkpDsroixRXw-sTw-Wfqo4NxjMwwM";
const auto kAppId = "1:560508485281:web:4ee13a6af4e84d49e67ae0";
struct DnsEntry {
QString data;
crl::time TTL = 0;
};
const std::vector<QString> &DnsDomains() {
static auto result = std::vector<QString>{
qsl("google.com"),
qsl("www.google.com"),
qsl("google.ru"),
qsl("www.google.ru"),
};
return result;
}
QString ApiDomain(const QString &service) {
return service + ".googleapis.com";
}
QString GenerateInstanceId() {
auto fid = bytes::array<17>();
bytes::set_random(fid);
fid[0] = (bytes::type(0xF0) & fid[0]) | bytes::type(0x07);
return QString::fromLatin1(
QByteArray::fromRawData(
reinterpret_cast<const char*>(fid.data()),
fid.size()
).toBase64(QByteArray::Base64UrlEncoding).mid(0, 22));
}
QString InstanceId() {
static const auto result = GenerateInstanceId();
return result;
}
bool CheckPhoneByPrefixesRules(const QString &phone, const QString &rules) {
const auto check = QString(phone).replace(
QRegularExpression("[^0-9]"),
QString());
auto result = false;
for (const auto &prefix : rules.split(',')) {
if (prefix.isEmpty()) {
result = true;
} else if (prefix[0] == '+' && check.startsWith(prefix.mid(1))) {
result = true;
} else if (prefix[0] == '-' && check.startsWith(prefix.mid(1))) {
return false;
}
}
return result;
}
QString GenerateRandomPadding() {
constexpr char kValid[] = "abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
auto result = QString();
const auto count = [&] {
constexpr auto kMinPadding = 13;
constexpr auto kMaxPadding = 128;
while (true) {
const auto result = 1 + (rand_value<uchar>() / 2);
Assert(result <= kMaxPadding);
if (result >= kMinPadding) {
return result;
}
}
}();
result.resize(count);
for (auto &ch : result) {
ch = kValid[rand_value<uchar>() % (sizeof(kValid) - 1)];
}
return result;
}
std::vector<DnsEntry> ParseDnsResponse(
const QByteArray &bytes,
std::optional<int> typeRestriction = std::nullopt) {
// Read and store to "result" all the data bytes from the response:
// { ..,
// "Answer": [
// { .., "data": "bytes1", "TTL": int, .. },
// { .., "data": "bytes2", "TTL": int, .. }
// ],
// .. }
auto error = QJsonParseError{ 0, QJsonParseError::NoError };
const auto document = QJsonDocument::fromJson(bytes, &error);
if (error.error != QJsonParseError::NoError) {
LOG(("Config Error: Failed to parse dns response JSON, error: %1"
).arg(error.errorString()));
return {};
} else if (!document.isObject()) {
LOG(("Config Error: Not an object received in dns response JSON."));
return {};
}
const auto response = document.object();
const auto answerIt = response.find(qsl("Answer"));
if (answerIt == response.constEnd()) {
LOG(("Config Error: Could not find Answer in dns response JSON."));
return {};
} else if (!(*answerIt).isArray()) {
LOG(("Config Error: Not an array received "
"in Answer in dns response JSON."));
return {};
}
auto result = std::vector<DnsEntry>();
for (const auto elem : (*answerIt).toArray()) {
if (!elem.isObject()) {
LOG(("Config Error: Not an object found "
"in Answer array in dns response JSON."));
continue;
}
const auto object = elem.toObject();
if (typeRestriction) {
const auto typeIt = object.find(qsl("type"));
const auto type = int(std::round((*typeIt).toDouble()));
if (!(*typeIt).isDouble()) {
LOG(("Config Error: Not a number in type field "
"in Answer array in dns response JSON."));
continue;
} else if (type != *typeRestriction) {
continue;
}
}
const auto dataIt = object.find(qsl("data"));
if (dataIt == object.constEnd()) {
LOG(("Config Error: Could not find data "
"in Answer array entry in dns response JSON."));
continue;
} else if (!(*dataIt).isString()) {
LOG(("Config Error: Not a string data found "
"in Answer array entry in dns response JSON."));
continue;
}
const auto ttlIt = object.find(qsl("TTL"));
const auto ttl = (ttlIt != object.constEnd())
? crl::time(std::round((*ttlIt).toDouble()))
: crl::time(0);
result.push_back({ (*dataIt).toString(), ttl });
}
return result;
}
QByteArray ConcatenateDnsTxtFields(const std::vector<DnsEntry> &response) {
auto entries = QMap<int, QString>();
for (const auto &entry : response) {
entries.insertMulti(INT_MAX - entry.data.size(), entry.data);
}
return QStringList(entries.values()).join(QString()).toLatin1();
}
QByteArray ParseRemoteConfigResponse(const QByteArray &bytes) {
auto error = QJsonParseError{ 0, QJsonParseError::NoError };
const auto document = QJsonDocument::fromJson(bytes, &error);
if (error.error != QJsonParseError::NoError) {
LOG(("Config Error: Failed to parse fire response JSON, error: %1"
).arg(error.errorString()));
return {};
} else if (!document.isObject()) {
LOG(("Config Error: Not an object received in fire response JSON."));
return {};
}
return document.object().value(
"entries"
).toObject().value(
qsl("%1%2").arg(kConfigKey).arg(kConfigSubKey)
).toString().toLatin1();
}
QByteArray ParseFireStoreResponse(const QByteArray &bytes) {
auto error = QJsonParseError{ 0, QJsonParseError::NoError };
const auto document = QJsonDocument::fromJson(bytes, &error);
if (error.error != QJsonParseError::NoError) {
LOG(("Config Error: Failed to parse fire response JSON, error: %1"
).arg(error.errorString()));
return {};
} else if (!document.isObject()) {
LOG(("Config Error: Not an object received in fire response JSON."));
return {};
}
return document.object().value(
"fields"
).toObject().value(
"data"
).toObject().value(
"stringValue"
).toString().toLatin1();
}
QByteArray ParseRealtimeResponse(const QByteArray &bytes) {
if (bytes.size() < 2
|| bytes[0] != '"'
|| bytes[bytes.size() - 1] != '"') {
return QByteArray();
}
return bytes.mid(1, bytes.size() - 2);
}
[[nodiscard]] QDateTime ParseHttpDate(const QString &date) {
// Wed, 10 Jul 2019 14:33:38 GMT
static const auto expression = QRegularExpression(
R"(\w\w\w, (\d\d) (\w\w\w) (\d\d\d\d) (\d\d):(\d\d):(\d\d) GMT)");
const auto match = expression.match(date);
if (!match.hasMatch()) {
return QDateTime();
}
const auto number = [&](int index) {
return match.capturedRef(index).toInt();
};
const auto day = number(1);
const auto month = [&] {
static const auto months = {
"Jan",
"Feb",
"Mar",
"Apr",
"May",
"Jun",
"Jul",
"Aug",
"Sep",
"Oct",
"Nov",
"Dec"
};
const auto captured = match.capturedRef(2);
for (auto i = begin(months); i != end(months); ++i) {
if (captured == (*i)) {
return 1 + int(i - begin(months));
}
}
return 0;
}();
const auto year = number(3);
const auto hour = number(4);
const auto minute = number(5);
const auto second = number(6);
return QDateTime(
QDate(year, month, day),
QTime(hour, minute, second),
Qt::UTC);
}
} // namespace
ServiceWebRequest::ServiceWebRequest(not_null<QNetworkReply*> reply)
: reply(reply.get()) {
}
ServiceWebRequest::ServiceWebRequest(ServiceWebRequest &&other)
: reply(base::take(other.reply)) {
}
ServiceWebRequest &ServiceWebRequest::operator=(ServiceWebRequest &&other) {
if (reply != other.reply) {
destroy();
reply = base::take(other.reply);
}
return *this;
}
void ServiceWebRequest::destroy() {
if (const auto value = base::take(reply)) {
value->disconnect(
value,
&QNetworkReply::finished,
nullptr,
nullptr);
value->abort();
value->deleteLater();
}
}
ServiceWebRequest::~ServiceWebRequest() {
if (reply) {
reply->deleteLater();
}
}
SpecialConfigRequest::SpecialConfigRequest(
Fn<void(
DcId dcId,
const std::string &ip,
int port,
bytes::const_span secret)> callback,
Fn<void()> timeDoneCallback,
const QString &phone)
: _callback(std::move(callback))
, _timeDoneCallback(std::move(timeDoneCallback))
, _phone(phone) {
Expects((_callback == nullptr) != (_timeDoneCallback == nullptr));
_manager.setProxy(QNetworkProxy::NoProxy);
auto domains = DnsDomains();
const auto domainsCount = domains.size();
std::random_device rd;
ranges::shuffle(domains, std::mt19937(rd()));
const auto takeDomain = [&] {
const auto result = domains.back();
domains.pop_back();
return result;
};
const auto shuffle = [&](int from, int till) {
Expects(till > from);
ranges::shuffle(
begin(_attempts) + from,
begin(_attempts) + till,
std::mt19937(rd()));
};
_attempts = {};
_attempts.push_back({ Type::Google, "dns.google.com" });
_attempts.push_back({ Type::Google, takeDomain(), "dns" });
_attempts.push_back({ Type::Mozilla, "mozilla.cloudflare-dns.com" });
_attempts.push_back({ Type::RemoteConfig, "firebaseremoteconfig" });
while (!domains.empty()) {
_attempts.push_back({ Type::Google, takeDomain(), "dns" });
}
if (!_timeDoneCallback) {
_attempts.push_back({ Type::Realtime, "firebaseio.com" });
_attempts.push_back({ Type::FireStore, "firestore" });
for (const auto &domain : DnsDomains()) {
_attempts.push_back({ Type::FireStore, domain, "firestore" });
}
}
shuffle(0, 2);
shuffle(2, 4);
if (!_timeDoneCallback) {
shuffle(
_attempts.size() - (2 + domainsCount),
_attempts.size() - domainsCount);
shuffle(_attempts.size() - domainsCount, _attempts.size());
}
ranges::reverse(_attempts); // We go from last to first.
sendNextRequest();
}
SpecialConfigRequest::SpecialConfigRequest(
Fn<void(
DcId dcId,
const std::string &ip,
int port,
bytes::const_span secret)> callback,
const QString &phone)
: SpecialConfigRequest(std::move(callback), nullptr, phone) {
}
SpecialConfigRequest::SpecialConfigRequest(Fn<void()> timeDoneCallback)
: SpecialConfigRequest(nullptr, std::move(timeDoneCallback), QString()) {
}
void SpecialConfigRequest::sendNextRequest() {
Expects(!_attempts.empty());
const auto attempt = _attempts.back();
_attempts.pop_back();
if (!_attempts.empty()) {
base::call_delayed(kSendNextTimeout, this, [=] {
sendNextRequest();
});
}
performRequest(attempt);
}
void SpecialConfigRequest::performRequest(const Attempt &attempt) {
const auto type = attempt.type;
auto url = QUrl();
url.setScheme(qsl("https"));
auto request = QNetworkRequest();
auto payload = QByteArray();
switch (type) {
case Type::Mozilla: {
url.setHost(attempt.data);
url.setPath(qsl("/dns-query"));
url.setQuery(qsl("name=%1&type=16&random_padding=%2"
).arg(Global::TxtDomainString()
).arg(GenerateRandomPadding()));
request.setRawHeader("accept", "application/dns-json");
} break;
case Type::Google: {
url.setHost(attempt.data);
url.setPath(qsl("/resolve"));
url.setQuery(qsl("name=%1&type=ANY&random_padding=%2"
).arg(Global::TxtDomainString()
).arg(GenerateRandomPadding()));
if (!attempt.host.isEmpty()) {
const auto host = attempt.host + ".google.com";
request.setRawHeader("Host", host.toLatin1());
}
} break;
case Type::RemoteConfig: {
url.setHost(ApiDomain(attempt.data));
url.setPath(qsl("/v1/projects/%1/namespaces/firebase:fetch"
).arg(kRemoteProject));
url.setQuery(qsl("key=%1").arg(kApiKey));
payload = qsl("{\"app_id\":\"%1\",\"app_instance_id\":\"%2\"}"
).arg(kAppId
).arg(InstanceId()).toLatin1();
request.setRawHeader("Content-Type", "application/json");
} break;
case Type::Realtime: {
url.setHost(kFireProject + qsl(".%1").arg(attempt.data));
url.setPath(qsl("/%1%2.json").arg(kConfigKey).arg(kConfigSubKey));
} break;
case Type::FireStore: {
url.setHost(attempt.host.isEmpty()
? ApiDomain(attempt.data)
: attempt.data);
url.setPath(qsl("/v1/projects/%1/databases/(default)/documents/%2/%3"
).arg(kFireProject
).arg(kConfigKey
).arg(kConfigSubKey));
if (!attempt.host.isEmpty()) {
const auto host = ApiDomain(attempt.host);
request.setRawHeader("Host", host.toLatin1());
}
} break;
default: Unexpected("Type in SpecialConfigRequest::performRequest.");
}
request.setUrl(url);
request.setRawHeader("User-Agent", kUserAgent);
const auto reply = _requests.emplace_back(payload.isEmpty()
? _manager.get(request)
: _manager.post(request, payload)
).reply;
connect(reply, &QNetworkReply::finished, this, [=] {
requestFinished(type, reply);
});
}
void SpecialConfigRequest::handleHeaderUnixtime(
not_null<QNetworkReply*> reply) {
if (reply->error() != QNetworkReply::NoError) {
return;
}
const auto date = QString::fromLatin1([&] {
for (const auto &pair : reply->rawHeaderPairs()) {
if (pair.first == "Date") {
return pair.second;
}
}
return QByteArray();
}());
if (date.isEmpty()) {
LOG(("Config Error: No 'Date' header received."));
return;
}
const auto parsed = ParseHttpDate(date);
if (!parsed.isValid()) {
LOG(("Config Error: Bad 'Date' header received: %1").arg(date));
return;
}
base::unixtime::http_update(parsed.toTime_t());
if (_timeDoneCallback) {
_timeDoneCallback();
}
}
void SpecialConfigRequest::requestFinished(
Type type,
not_null<QNetworkReply*> reply) {
handleHeaderUnixtime(reply);
const auto result = finalizeRequest(reply);
if (!_callback) {
return;
}
switch (type) {
case Type::Mozilla:
case Type::Google: {
constexpr auto kTypeRestriction = 16; // TXT
handleResponse(ConcatenateDnsTxtFields(
ParseDnsResponse(result, kTypeRestriction)));
} break;
case Type::RemoteConfig: {
handleResponse(ParseRemoteConfigResponse(result));
} break;
case Type::Realtime: {
handleResponse(ParseRealtimeResponse(result));
} break;
case Type::FireStore: {
handleResponse(ParseFireStoreResponse(result));
} break;
default: Unexpected("Type in SpecialConfigRequest::requestFinished.");
}
}
QByteArray SpecialConfigRequest::finalizeRequest(
not_null<QNetworkReply*> reply) {
if (reply->error() != QNetworkReply::NoError) {
LOG(("Config Error: Failed to get response, error: %2 (%3)"
).arg(reply->errorString()
).arg(reply->error()));
}
const auto result = reply->readAll();
const auto from = ranges::remove(
_requests,
reply,
[](const ServiceWebRequest &request) { return request.reply; });
_requests.erase(from, end(_requests));
return result;
}
bool SpecialConfigRequest::decryptSimpleConfig(const QByteArray &bytes) {
auto cleanBytes = bytes;
auto removeFrom = std::remove_if(cleanBytes.begin(), cleanBytes.end(), [](char ch) {
auto isGoodBase64 = (ch == '+') || (ch == '=') || (ch == '/')
|| (ch >= 'a' && ch <= 'z')
|| (ch >= 'A' && ch <= 'Z')
|| (ch >= '0' && ch <= '9');
return !isGoodBase64;
});
if (removeFrom != cleanBytes.end()) {
cleanBytes.remove(removeFrom - cleanBytes.begin(), cleanBytes.end() - removeFrom);
}
constexpr auto kGoodSizeBase64 = 344;
if (cleanBytes.size() != kGoodSizeBase64) {
LOG(("Config Error: Bad data size %1 required %2").arg(cleanBytes.size()).arg(kGoodSizeBase64));
return false;
}
constexpr auto kGoodSizeData = 256;
auto decodedBytes = QByteArray::fromBase64(cleanBytes, QByteArray::Base64Encoding);
if (decodedBytes.size() != kGoodSizeData) {
LOG(("Config Error: Bad data size %1 required %2").arg(decodedBytes.size()).arg(kGoodSizeData));
return false;
}
auto publicKey = internal::RSAPublicKey(bytes::make_span(
kPublicKey.c_str(),
kPublicKey.size()));
auto decrypted = publicKey.decrypt(bytes::make_span(decodedBytes));
auto decryptedBytes = gsl::make_span(decrypted);
auto aesEncryptedBytes = decryptedBytes.subspan(CTRState::KeySize);
auto aesivec = bytes::make_vector(decryptedBytes.subspan(CTRState::KeySize - CTRState::IvecSize, CTRState::IvecSize));
AES_KEY aeskey;
AES_set_decrypt_key(reinterpret_cast<const unsigned char*>(decryptedBytes.data()), CTRState::KeySize * CHAR_BIT, &aeskey);
AES_cbc_encrypt(reinterpret_cast<const unsigned char*>(aesEncryptedBytes.data()), reinterpret_cast<unsigned char*>(aesEncryptedBytes.data()), aesEncryptedBytes.size(), &aeskey, reinterpret_cast<unsigned char*>(aesivec.data()), AES_DECRYPT);
constexpr auto kDigestSize = 16;
auto dataSize = aesEncryptedBytes.size() - kDigestSize;
auto data = aesEncryptedBytes.subspan(0, dataSize);
auto hash = openssl::Sha256(data);
if (bytes::compare(gsl::make_span(hash).subspan(0, kDigestSize), aesEncryptedBytes.subspan(dataSize)) != 0) {
LOG(("Config Error: Bad digest."));
return false;
}
mtpBuffer buffer;
buffer.resize(data.size() / sizeof(mtpPrime));
bytes::copy(bytes::make_span(buffer), data);
auto from = &*buffer.cbegin();
auto end = from + buffer.size();
auto realLength = *from++;
if (realLength <= 0 || realLength > dataSize || (realLength & 0x03)) {
LOG(("Config Error: Bad length %1.").arg(realLength));
return false;
}
if (!_simpleConfig.read(from, end)) {
LOG(("Config Error: Could not read configSimple."));
return false;
}
if ((end - from) * sizeof(mtpPrime) != (dataSize - realLength)) {
LOG(("Config Error: Bad read length %1, should be %2.").arg((end - from) * sizeof(mtpPrime)).arg(dataSize - realLength));
return false;
}
return true;
}
void SpecialConfigRequest::handleResponse(const QByteArray &bytes) {
if (!decryptSimpleConfig(bytes)) {
return;
}
Assert(_simpleConfig.type() == mtpc_help_configSimple);
const auto &config = _simpleConfig.c_help_configSimple();
const auto now = base::unixtime::http_now();
if (now > config.vexpires().v) {
LOG(("Config Error: "
"Bad date frame for simple config: %1-%2, our time is %3."
).arg(config.vdate().v
).arg(config.vexpires().v
).arg(now));
return;
}
if (config.vrules().v.empty()) {
LOG(("Config Error: Empty simple config received."));
return;
}
for (const auto &rule : config.vrules().v) {
Assert(rule.type() == mtpc_accessPointRule);
const auto &data = rule.c_accessPointRule();
const auto phoneRules = qs(data.vphone_prefix_rules());
if (!CheckPhoneByPrefixesRules(_phone, phoneRules)) {
continue;
}
const auto dcId = data.vdc_id().v;
for (const auto &address : data.vips().v) {
const auto parseIp = [](const MTPint &ipv4) {
const auto ip = *reinterpret_cast<const uint32*>(&ipv4.v);
return qsl("%1.%2.%3.%4"
).arg((ip >> 24) & 0xFF
).arg((ip >> 16) & 0xFF
).arg((ip >> 8) & 0xFF
).arg(ip & 0xFF).toStdString();
};
switch (address.type()) {
case mtpc_ipPort: {
const auto &fields = address.c_ipPort();
const auto ip = parseIp(fields.vipv4());
if (!ip.empty()) {
_callback(dcId, ip, fields.vport().v, {});
}
} break;
case mtpc_ipPortSecret: {
const auto &fields = address.c_ipPortSecret();
const auto ip = parseIp(fields.vipv4());
if (!ip.empty()) {
_callback(
dcId,
ip,
fields.vport().v,
bytes::make_span(fields.vsecret().v));
}
} break;
default: Unexpected("Type in simpleConfig ips.");
}
}
}
_callback(0, std::string(), 0, {});
}
DomainResolver::DomainResolver(Fn<void(
const QString &host,
const QStringList &ips,
crl::time expireAt)> callback)
: _callback(std::move(callback)) {
_manager.setProxy(QNetworkProxy::NoProxy);
}
void DomainResolver::resolve(const QString &domain) {
resolve({ domain, false });
resolve({ domain, true });
}
void DomainResolver::resolve(const AttemptKey &key) {
if (_attempts.find(key) != end(_attempts)) {
return;
} else if (_requests.find(key) != end(_requests)) {
return;
}
const auto i = _cache.find(key);
_lastTimestamp = crl::now();
if (i != end(_cache) && i->second.expireAt > _lastTimestamp) {
checkExpireAndPushResult(key.domain);
return;
}
auto attempts = std::vector<Attempt>();
auto domains = DnsDomains();
std::random_device rd;
ranges::shuffle(domains, std::mt19937(rd()));
const auto takeDomain = [&] {
const auto result = domains.back();
domains.pop_back();
return result;
};
const auto shuffle = [&](int from, int till) {
Expects(till > from);
ranges::shuffle(
begin(attempts) + from,
begin(attempts) + till,
std::mt19937(rd()));
};
attempts.push_back({ Type::Google, "dns.google.com" });
attempts.push_back({ Type::Google, takeDomain(), "dns" });
attempts.push_back({ Type::Mozilla, "mozilla.cloudflare-dns.com" });
while (!domains.empty()) {
attempts.push_back({ Type::Google, takeDomain(), "dns" });
}
shuffle(0, 2);
ranges::reverse(attempts); // We go from last to first.
_attempts.emplace(key, Attempts{ std::move(attempts) });
sendNextRequest(key);
}
void DomainResolver::checkExpireAndPushResult(const QString &domain) {
const auto ipv4 = _cache.find({ domain, false });
if (ipv4 == end(_cache) || ipv4->second.expireAt <= _lastTimestamp) {
return;
}
auto result = ipv4->second;
const auto ipv6 = _cache.find({ domain, true });
if (ipv6 != end(_cache) && ipv6->second.expireAt > _lastTimestamp) {
result.ips.append(ipv6->second.ips);
accumulate_min(result.expireAt, ipv6->second.expireAt);
}
InvokeQueued(this, [=] {
_callback(domain, result.ips, result.expireAt);
});
}
void DomainResolver::sendNextRequest(const AttemptKey &key) {
auto i = _attempts.find(key);
if (i == end(_attempts)) {
return;
}
auto &attempts = i->second;
auto &list = attempts.list;
const auto attempt = list.back();
list.pop_back();
if (!list.empty()) {
base::call_delayed(kSendNextTimeout, &attempts.guard, [=] {
sendNextRequest(key);
});
}
performRequest(key, attempt);
}
void DomainResolver::performRequest(
const AttemptKey &key,
const Attempt &attempt) {
auto url = QUrl();
url.setScheme(qsl("https"));
auto request = QNetworkRequest();
switch (attempt.type) {
case Type::Mozilla: {
url.setHost(attempt.data);
url.setPath(qsl("/dns-query"));
url.setQuery(qsl("name=%1&type=%2&random_padding=%3"
).arg(key.domain
).arg(key.ipv6 ? 28 : 1
).arg(GenerateRandomPadding()));
request.setRawHeader("accept", "application/dns-json");
} break;
case Type::Google: {
url.setHost(attempt.data);
url.setPath(qsl("/resolve"));
url.setQuery(qsl("name=%1&type=%2&random_padding=%3"
).arg(key.domain
).arg(key.ipv6 ? 28 : 1
).arg(GenerateRandomPadding()));
if (!attempt.host.isEmpty()) {
const auto host = attempt.host + ".google.com";
request.setRawHeader("Host", host.toLatin1());
}
} break;
default: Unexpected("Type in SpecialConfigRequest::performRequest.");
}
request.setUrl(url);
request.setRawHeader("User-Agent", kUserAgent);
const auto i = _requests.emplace(
key,
std::vector<ServiceWebRequest>()).first;
const auto reply = i->second.emplace_back(
_manager.get(request)
).reply;
connect(reply, &QNetworkReply::finished, this, [=] {
requestFinished(key, reply);
});
}
void DomainResolver::requestFinished(
const AttemptKey &key,
not_null<QNetworkReply*> reply) {
const auto result = finalizeRequest(key, reply);
const auto response = ParseDnsResponse(result);
if (response.empty()) {
return;
}
_requests.erase(key);
_attempts.erase(key);
auto entry = CacheEntry();
auto ttl = kMaxTimeToLive;
for (const auto &item : response) {
entry.ips.push_back(item.data);
accumulate_min(ttl, std::max(
item.TTL * crl::time(1000),
kMinTimeToLive));
}
_lastTimestamp = crl::now();
entry.expireAt = _lastTimestamp + ttl;
_cache[key] = std::move(entry);
checkExpireAndPushResult(key.domain);
}
QByteArray DomainResolver::finalizeRequest(
const AttemptKey &key,
not_null<QNetworkReply*> reply) {
if (reply->error() != QNetworkReply::NoError) {
LOG(("Resolve Error: Failed to get response, error: %2 (%3)"
).arg(reply->errorString()
).arg(reply->error()));
}
const auto result = reply->readAll();
const auto i = _requests.find(key);
if (i != end(_requests)) {
auto &requests = i->second;
const auto from = ranges::remove(
requests,
reply,
[](const ServiceWebRequest &request) { return request.reply; });
requests.erase(from, end(requests));
if (requests.empty()) {
_requests.erase(i);
}
}
return result;
}
} // namespace MTP