aria2/src/PeerConnection.cc

249 lines
7.5 KiB
C++

/* <!-- copyright */
/*
* aria2 - The high speed download utility
*
* Copyright (C) 2006 Tatsuhiro Tsujikawa
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* In addition, as a special exception, the copyright holders give
* permission to link the code of portions of this program with the
* OpenSSL library under certain conditions as described in each
* individual source file, and distribute linked combinations
* including the two.
* You must obey the GNU General Public License in all respects
* for all of the code used other than OpenSSL. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you
* do not wish to do so, delete this exception statement from your
* version. If you delete this exception statement from all source
* files in the program, then also delete it here.
*/
/* copyright --> */
#include "PeerConnection.h"
#include "message.h"
#include "DlAbortEx.h"
#include "LogFactory.h"
#include "Logger.h"
#include "BtHandshakeMessage.h"
#include "Socket.h"
#include "a2netcompat.h"
#include "ARC4Encryptor.h"
#include "ARC4Decryptor.h"
#include "StringFormat.h"
#include <cstring>
#include <cassert>
#include <algorithm>
namespace aria2 {
PeerConnection::PeerConnection(int32_t cuid,
const SocketHandle& socket,
const Option* op)
:cuid(cuid),
socket(socket),
option(op),
logger(LogFactory::getInstance()),
resbufLength(0),
currentPayloadLength(0),
lenbufLength(0),
_socketBuffer(socket),
_encryptionEnabled(false),
_prevPeek(false)
{}
PeerConnection::~PeerConnection() {}
ssize_t PeerConnection::sendMessage(const unsigned char* data,
size_t dataLength)
{
ssize_t writtenLength = sendData(data, dataLength, _encryptionEnabled);
logger->debug("sent %d byte(s).", writtenLength);
return writtenLength;
}
bool PeerConnection::receiveMessage(unsigned char* data, size_t& dataLength) {
if(resbufLength == 0 && 4 > lenbufLength) {
if(!socket->isReadable(0)) {
return false;
}
// read payload size, 32bit unsigned integer
size_t remaining = 4-lenbufLength;
size_t temp = remaining;
readData(lenbuf+lenbufLength, remaining, _encryptionEnabled);
if(remaining == 0) {
if(socket->wantRead() || socket->wantWrite()) {
return false;
}
// we got EOF
logger->debug("CUID#%d - In PeerConnection::receiveMessage(), remain=%lu",
cuid, static_cast<unsigned long>(temp));
throw DlAbortEx(EX_EOF_FROM_PEER);
}
lenbufLength += remaining;
if(4 > lenbufLength) {
// still 4-lenbufLength bytes to go
return false;
}
uint32_t payloadLength = ntohl(*(reinterpret_cast<uint32_t*>(lenbuf)));
if(payloadLength > MAX_PAYLOAD_LEN) {
throw DlAbortEx(StringFormat(EX_TOO_LONG_PAYLOAD, payloadLength).str());
}
currentPayloadLength = payloadLength;
}
if(!socket->isReadable(0)) {
return false;
}
// we have currentPayloadLen-resbufLen bytes to read
size_t remaining = currentPayloadLength-resbufLength;
size_t temp = remaining;
if(remaining > 0) {
readData(resbuf+resbufLength, remaining, _encryptionEnabled);
if(remaining == 0) {
if(socket->wantRead() || socket->wantWrite()) {
return false;
}
// we got EOF
logger->debug("CUID#%d - In PeerConnection::receiveMessage(),"
" payloadlen=%lu, remaining=%lu",
cuid,
static_cast<unsigned long>(currentPayloadLength),
static_cast<unsigned long>(temp));
throw DlAbortEx(EX_EOF_FROM_PEER);
}
resbufLength += remaining;
if(currentPayloadLength > resbufLength) {
return false;
}
}
// we got whole payload.
resbufLength = 0;
lenbufLength = 0;
memcpy(data, resbuf, currentPayloadLength);
dataLength = currentPayloadLength;
return true;
}
bool PeerConnection::receiveHandshake(unsigned char* data, size_t& dataLength,
bool peek) {
assert(BtHandshakeMessage::MESSAGE_LENGTH >= resbufLength);
bool retval = true;
if(_prevPeek && !peek && resbufLength) {
// We have data in previous peek.
// There is a chance that socket is readable because of EOF, for example,
// official bttrack shutdowns socket after sending first 48 bytes of
// handshake in its NAT checking.
// So if there are data in resbuf, return it without checking socket
// status.
_prevPeek = false;
retval = BtHandshakeMessage::MESSAGE_LENGTH <= resbufLength;
} else {
_prevPeek = peek;
size_t remaining = BtHandshakeMessage::MESSAGE_LENGTH-resbufLength;
if(remaining > 0 && !socket->isReadable(0)) {
dataLength = 0;
return false;
}
if(remaining > 0) {
size_t temp = remaining;
readData(resbuf+resbufLength, remaining, _encryptionEnabled);
if(remaining == 0) {
if(socket->wantRead() || socket->wantWrite()) {
return false;
}
// we got EOF
logger->debug
("CUID#%d - In PeerConnection::receiveHandshake(), remain=%lu",
cuid, static_cast<unsigned long>(temp));
throw DlAbortEx(EX_EOF_FROM_PEER);
}
resbufLength += remaining;
if(BtHandshakeMessage::MESSAGE_LENGTH > resbufLength) {
retval = false;
}
}
}
size_t writeLength = std::min(resbufLength, dataLength);
memcpy(data, resbuf, writeLength);
dataLength = writeLength;
if(retval && !peek) {
resbufLength = 0;
}
return retval;
}
void PeerConnection::readData(unsigned char* data, size_t& length, bool encryption)
{
if(encryption) {
unsigned char temp[MAX_PAYLOAD_LEN];
assert(MAX_PAYLOAD_LEN >= length);
socket->readData(temp, length);
_decryptor->decrypt(data, length, temp, length);
} else {
socket->readData(data, length);
}
}
ssize_t PeerConnection::sendData(const unsigned char* data,
size_t length, bool encryption)
{
if(encryption) {
unsigned char temp[4096];
const unsigned char* dptr = data;
size_t r = length;
while(r > 0) {
size_t s = std::min(r, sizeof(temp));
_encryptor->encrypt(temp, s, dptr, s);
_socketBuffer.feedSendBuffer(std::string(&temp[0], &temp[s]));
dptr += s;
r -= s;
}
} else {
_socketBuffer.feedSendBuffer(std::string(&data[0], &data[length]));
}
return _socketBuffer.send();
}
void PeerConnection::enableEncryption(const SharedHandle<ARC4Encryptor>& encryptor,
const SharedHandle<ARC4Decryptor>& decryptor)
{
_encryptor = encryptor;
_decryptor = decryptor;
_encryptionEnabled = true;
}
void PeerConnection::presetBuffer(const unsigned char* data, size_t length)
{
size_t nwrite = std::min((size_t)MAX_PAYLOAD_LEN, length);
memcpy(resbuf, data, nwrite);
resbufLength = length;
}
bool PeerConnection::sendBufferIsEmpty() const
{
return _socketBuffer.sendBufferIsEmpty();
}
ssize_t PeerConnection::sendPendingData()
{
ssize_t writtenLength = _socketBuffer.send();
logger->debug("sent %d byte(s).", writtenLength);
return writtenLength;
}
} // namespace aria2