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Fix crash in tcp connection implementation.

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This commit is contained in:
John Preston 2018-07-20 15:28:26 +03:00
parent 06fc23fc59
commit 4c0551ebb1
2 changed files with 34 additions and 23 deletions
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56
Telegram/SourceFiles/mtproto/connection_tcp.cpp
View file

@ -22,6 +22,7 @@ namespace {
constexpr auto kPacketSizeMax = int(0x01000000 * sizeof(mtpPrime));
constexpr auto kFullConnectionTimeout = 8 * TimeMs(1000);
constexpr auto kSmallBufferSize = 256 * 1024;
constexpr auto kMinPacketBuffer = 256;
using ErrorSignal = void(QTcpSocket::*)(QAbstractSocket::SocketError);
const auto QTcpSocket_error = ErrorSignal(&QAbstractSocket::error);
@ -266,6 +267,34 @@ ConnectionPointer TcpConnection::clone(const ProxyData &proxy) {
return ConnectionPointer::New<TcpConnection>(thread(), proxy);
}
void TcpConnection::ensureAvailableInBuffer(int amount) {
auto &buffer = _usingLargeBuffer ? _largeBuffer : _smallBuffer;
const auto full = bytes::make_span(buffer).subspan(
_offsetBytes);
if (full.size() >= amount) {
return;
}
const auto read = full.subspan(0, _readBytes);
if (amount <= _smallBuffer.size()) {
if (_usingLargeBuffer) {
bytes::copy(_smallBuffer, read);
_usingLargeBuffer = false;
_largeBuffer.clear();
} else {
bytes::move(_smallBuffer, read);
}
} else if (amount <= _largeBuffer.size()) {
Assert(_usingLargeBuffer);
bytes::move(_largeBuffer, read);
} else {
auto enough = bytes::vector(amount);
bytes::copy(enough, read);
_largeBuffer = std::move(enough);
_usingLargeBuffer = true;
}
_offsetBytes = 0;
}
void TcpConnection::socketRead() {
Expects(_leftBytes > 0 || !_usingLargeBuffer);
@ -332,33 +361,14 @@ void TcpConnection::socketRead() {
available = available.subspan(packetSize);
_offsetBytes += packetSize;
_readBytes -= packetSize;
// If we have too little space left in the buffer.
ensureAvailableInBuffer(kMinPacketBuffer);
} else {
_leftBytes = packetSize - available.size();
// If the next packet won't fit in the buffer.
const auto full = bytes::make_span(buffer).subspan(
_offsetBytes);
if (full.size() < packetSize) {
const auto read = full.subspan(0, _readBytes);
if (packetSize <= _smallBuffer.size()) {
if (_usingLargeBuffer) {
bytes::copy(_smallBuffer, read);
_usingLargeBuffer = false;
_largeBuffer.clear();
} else {
bytes::move(_smallBuffer, read);
}
} else if (packetSize <= _largeBuffer.size()) {
Assert(_usingLargeBuffer);
bytes::move(_largeBuffer, read);
} else {
auto enough = bytes::vector(packetSize);
bytes::copy(enough, read);
_largeBuffer = std::move(enough);
_usingLargeBuffer = true;
}
_offsetBytes = 0;
}
ensureAvailableInBuffer(packetSize);
TCP_LOG(("TCP Info: not enough %1 for packet! "
"full size %2 read %3"

1
Telegram/SourceFiles/mtproto/connection_tcp.h
View file

@ -58,6 +58,7 @@ private:
void socketError(QAbstractSocket::SocketError e);
mtpBuffer parsePacket(bytes::const_span bytes);
void ensureAvailableInBuffer(int amount);
static void handleError(QAbstractSocket::SocketError e, QTcpSocket &sock);
static uint32 fourCharsToUInt(char ch1, char ch2, char ch3, char ch4) {
char ch[4] = { ch1, ch2, ch3, ch4 };