src/base/http/connection.cpp

   1 /*
   2  * Bittorrent Client using Qt and libtorrent.
   3  * Copyright (C) 2018  Mike Tzou (Chocobo1)
   4  * Copyright (C) 2014  Vladimir Golovnev <glassez@yandex.ru>
   5  * Copyright (C) 2006  Ishan Arora and Christophe Dumez <chris@qbittorrent.org>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20  *
  21  * In addition, as a special exception, the copyright holders give permission to
  22  * link this program with the OpenSSL project's "OpenSSL" library (or with
  23  * modified versions of it that use the same license as the "OpenSSL" library),
  24  * and distribute the linked executables. You must obey the GNU General Public
  25  * License in all respects for all of the code used other than "OpenSSL".  If you
  26  * modify file(s), you may extend this exception to your version of the file(s),
  27  * but you are not obligated to do so. If you do not wish to do so, delete this
  28  * exception statement from your version.
  29  */
  30
  31 #include "connection.h"
  32
  33 #include <QTcpSocket>
  34
  35 #include "irequesthandler.h"
  36 #include "requestparser.h"
  37 #include "responsegenerator.h"
  38
  39 using namespace Http;
  40
  41 Connection::Connection(QTcpSocket *socket, IRequestHandler *requestHandler, QObject *parent)
  42     : QObject(parent)
  43     , m_socket(socket)
  44     , m_requestHandler(requestHandler)
  45 {
  46     m_socket->setParent(this);
  47
  48     // reserve common size for requests, don't use the max allowed size which is too big for
  49     // memory constrained platforms
  50     m_receivedData.reserve(1024 * 1024);
  51
  52     // reset timer when there are activity
  53     m_idleTimer.start();
  54     connect(m_socket, &QIODevice::readyRead, this, [this]()
  55     {
  56         m_idleTimer.start();
  57         read();
  58     });
  59     connect(m_socket, &QIODevice::bytesWritten, this, [this]()
  60     {
  61         m_idleTimer.start();
  62     });
  63 }
  64
  65 Connection::~Connection()
  66 {
  67     m_socket->close();
  68 }
  69
  70 void Connection::read()
  71 {
  72     // reuse existing buffer and avoid unnecessary memory allocation/relocation
  73     const qsizetype previousSize = m_receivedData.size();
  74     const qint64 bytesAvailable = m_socket->bytesAvailable();
  75     m_receivedData.resize(previousSize + bytesAvailable);
  76     const qint64 bytesRead = m_socket->read((m_receivedData.data() + previousSize), bytesAvailable);
  77     if (Q_UNLIKELY(bytesRead < 0))
  78     {
  79         m_socket->close();
  80         return;
  81     }
  82     if (Q_UNLIKELY(bytesRead < bytesAvailable))
  83         m_receivedData.chop(bytesAvailable - bytesRead);
  84
  85     while (!m_receivedData.isEmpty())
  86     {
  87         const RequestParser::ParseResult result = RequestParser::parse(m_receivedData);
  88
  89         switch (result.status)
  90         {
  91         case RequestParser::ParseStatus::Incomplete:
  92             {
  93                 const long bufferLimit = RequestParser::MAX_CONTENT_SIZE * 1.1;  // some margin for headers
  94                 if (m_receivedData.size() > bufferLimit)
  95                 {
  96                     qWarning("%s", qUtf8Printable(tr("Http request size exceeds limitation, closing socket. Limit: %1, IP: %2")
  97                         .arg(QString::number(bufferLimit), m_socket->peerAddress().toString())));
  98
  99                     Response resp(413, u"Payload Too Large"_s);
 100                     resp.headers[HEADER_CONNECTION] = u"close"_s;
 101
 102                     sendResponse(resp);
 103                     m_socket->close();
 104                 }
 105             }
 106             return;
 107
 108         case RequestParser::ParseStatus::BadMethod:
 109             {
 110                 qWarning("%s", qUtf8Printable(tr("Bad Http request method, closing socket. IP: %1. Method: \"%2\"")
 111                     .arg(m_socket->peerAddress().toString(), result.request.method)));
 112
 113                 Response resp(501, u"Not Implemented"_s);
 114                 resp.headers[HEADER_CONNECTION] = u"close"_s;
 115
 116                 sendResponse(resp);
 117                 m_socket->close();
 118             }
 119             return;
 120
 121         case RequestParser::ParseStatus::BadRequest:
 122             {
 123                 qWarning("%s", qUtf8Printable(tr("Bad Http request, closing socket. IP: %1")
 124                     .arg(m_socket->peerAddress().toString())));
 125
 126                 Response resp(400, u"Bad Request"_s);
 127                 resp.headers[HEADER_CONNECTION] = u"close"_s;
 128
 129                 sendResponse(resp);
 130                 m_socket->close();
 131             }
 132             return;
 133
 134         case RequestParser::ParseStatus::OK:
 135             {
 136                 const Environment env {m_socket->localAddress(), m_socket->localPort(), m_socket->peerAddress(), m_socket->peerPort()};
 137
 138                 if (result.request.method == HEADER_REQUEST_METHOD_HEAD)
 139                 {
 140                     Request getRequest = result.request;
 141                     getRequest.method = HEADER_REQUEST_METHOD_GET;
 142
 143                     Response resp = m_requestHandler->processRequest(getRequest, env);
 144
 145                     resp.headers[HEADER_CONNECTION] = u"keep-alive"_s;
 146                     resp.headers[HEADER_CONTENT_LENGTH] = QString::number(resp.content.length());
 147                     resp.content.clear();
 148
 149                     sendResponse(resp);
 150                 }
 151                 else
 152                 {
 153                     Response resp = m_requestHandler->processRequest(result.request, env);
 154
 155                     if (acceptsGzipEncoding(result.request.headers.value(u"accept-encoding"_s)))
 156                         resp.headers[HEADER_CONTENT_ENCODING] = u"gzip"_s;
 157                     resp.headers[HEADER_CONNECTION] = u"keep-alive"_s;
 158
 159                     sendResponse(resp);
 160                 }
 161
 162                 m_receivedData.remove(0, result.frameSize);
 163             }
 164             break;
 165
 166         default:
 167             Q_ASSERT(false);
 168             return;
 169         }
 170     }
 171 }
 172
 173 void Connection::sendResponse(const Response &response) const
 174 {
 175     m_socket->write(toByteArray(response));
 176 }
 177
 178 bool Connection::hasExpired(const qint64 timeout) const
 179 {
 180     return (m_socket->bytesAvailable() == 0)
 181         && (m_socket->bytesToWrite() == 0)
 182         && m_idleTimer.hasExpired(timeout);
 183 }
 184
 185 bool Connection::isClosed() const
 186 {
 187     return (m_socket->state() == QAbstractSocket::UnconnectedState);
 188 }
 189
 190 bool Connection::acceptsGzipEncoding(QString codings)
 191 {
 192     // [rfc7231] 5.3.4. Accept-Encoding
 193
 194     const auto isCodingAvailable = [](const QList<QStringView> &list, const QStringView encoding) -> bool
 195     {
 196         for (const QStringView &str : list)
 197         {
 198             if (!str.startsWith(encoding))
 199                 continue;
 200
 201             // without quality values
 202             if (str == encoding)
 203                 return true;
 204
 205             // [rfc7231] 5.3.1. Quality Values
 206             const QStringView substr = str.mid(encoding.size() + 3);  // ex. skip over "gzip;q="
 207
 208             bool ok = false;
 209             const double qvalue = substr.toDouble(&ok);
 210             if (!ok || (qvalue <= 0))
 211                 return false;
 212
 213             return true;
 214         }
 215         return false;
 216     };
 217
 218     const QList<QStringView> list = QStringView(codings.remove(u' ').remove(u'\t')).split(u',', Qt::SkipEmptyParts);
 219     if (list.isEmpty())
 220         return false;
 221
 222     const bool canGzip = isCodingAvailable(list, u"gzip"_s);
 223     if (canGzip)
 224         return true;
 225
 226     const bool canAny = isCodingAvailable(list, u"*"_s);
 227     if (canAny)
 228         return true;
 229
 230     return false;
 231 }