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     connect(m_socket, &QAbstractSocket::disconnected, this, &Connection::closed);
  48
  49     // reserve common size for requests, don't use the max allowed size which is too big for
  50     // memory constrained platforms
  51     m_receivedData.reserve(1024 * 1024);
  52
  53     // reset timer when there are activity
  54     m_idleTimer.start();
  55     connect(m_socket, &QIODevice::readyRead, this, [this]()
  56     {
  57         m_idleTimer.start();
  58         read();
  59     });
  60     connect(m_socket, &QIODevice::bytesWritten, this, [this]()
  61     {
  62         m_idleTimer.start();
  63     });
  64 }
  65
  66 void Connection::read()
  67 {
  68     // reuse existing buffer and avoid unnecessary memory allocation/relocation
  69     const qsizetype previousSize = m_receivedData.size();
  70     const qint64 bytesAvailable = m_socket->bytesAvailable();
  71     m_receivedData.resize(previousSize + bytesAvailable);
  72     const qint64 bytesRead = m_socket->read((m_receivedData.data() + previousSize), bytesAvailable);
  73     if (bytesRead < 0) [[unlikely]]
  74     {
  75         m_socket->close();
  76         return;
  77     }
  78     if (bytesRead < bytesAvailable) [[unlikely]]
  79         m_receivedData.chop(bytesAvailable - bytesRead);
  80
  81     while (!m_receivedData.isEmpty())
  82     {
  83         const RequestParser::ParseResult result = RequestParser::parse(m_receivedData);
  84
  85         switch (result.status)
  86         {
  87         case RequestParser::ParseStatus::Incomplete:
  88             {
  89                 const long bufferLimit = RequestParser::MAX_CONTENT_SIZE * 1.1;  // some margin for headers
  90                 if (m_receivedData.size() > bufferLimit)
  91                 {
  92                     qWarning("%s", qUtf8Printable(tr("Http request size exceeds limitation, closing socket. Limit: %1, IP: %2")
  93                         .arg(QString::number(bufferLimit), m_socket->peerAddress().toString())));
  94
  95                     Response resp(413, u"Payload Too Large"_s);
  96                     resp.headers[HEADER_CONNECTION] = u"close"_s;
  97
  98                     sendResponse(resp);
  99                     m_socket->close();
 100                 }
 101             }
 102             return;
 103
 104         case RequestParser::ParseStatus::BadMethod:
 105             {
 106                 qWarning("%s", qUtf8Printable(tr("Bad Http request method, closing socket. IP: %1. Method: \"%2\"")
 107                     .arg(m_socket->peerAddress().toString(), result.request.method)));
 108
 109                 Response resp(501, u"Not Implemented"_s);
 110                 resp.headers[HEADER_CONNECTION] = u"close"_s;
 111
 112                 sendResponse(resp);
 113                 m_socket->close();
 114             }
 115             return;
 116
 117         case RequestParser::ParseStatus::BadRequest:
 118             {
 119                 qWarning("%s", qUtf8Printable(tr("Bad Http request, closing socket. IP: %1")
 120                     .arg(m_socket->peerAddress().toString())));
 121
 122                 Response resp(400, u"Bad Request"_s);
 123                 resp.headers[HEADER_CONNECTION] = u"close"_s;
 124
 125                 sendResponse(resp);
 126                 m_socket->close();
 127             }
 128             return;
 129
 130         case RequestParser::ParseStatus::OK:
 131             {
 132                 const Environment env {m_socket->localAddress(), m_socket->localPort(), m_socket->peerAddress(), m_socket->peerPort()};
 133
 134                 if (result.request.method == HEADER_REQUEST_METHOD_HEAD)
 135                 {
 136                     Request getRequest = result.request;
 137                     getRequest.method = HEADER_REQUEST_METHOD_GET;
 138
 139                     Response resp = m_requestHandler->processRequest(getRequest, env);
 140
 141                     resp.headers[HEADER_CONNECTION] = u"keep-alive"_s;
 142                     resp.headers[HEADER_CONTENT_LENGTH] = QString::number(resp.content.length());
 143                     resp.content.clear();
 144
 145                     sendResponse(resp);
 146                 }
 147                 else
 148                 {
 149                     Response resp = m_requestHandler->processRequest(result.request, env);
 150
 151                     if (acceptsGzipEncoding(result.request.headers.value(u"accept-encoding"_s)))
 152                         resp.headers[HEADER_CONTENT_ENCODING] = u"gzip"_s;
 153                     resp.headers[HEADER_CONNECTION] = u"keep-alive"_s;
 154
 155                     sendResponse(resp);
 156                 }
 157
 158                 m_receivedData.remove(0, result.frameSize);
 159             }
 160             break;
 161
 162         default:
 163             Q_ASSERT(false);
 164             return;
 165         }
 166     }
 167 }
 168
 169 void Connection::sendResponse(const Response &response) const
 170 {
 171     m_socket->write(toByteArray(response));
 172 }
 173
 174 bool Connection::hasExpired(const qint64 timeout) const
 175 {
 176     return (m_socket->bytesAvailable() == 0)
 177         && (m_socket->bytesToWrite() == 0)
 178         && m_idleTimer.hasExpired(timeout);
 179 }
 180
 181 bool Connection::acceptsGzipEncoding(QString codings)
 182 {
 183     // [rfc7231] 5.3.4. Accept-Encoding
 184
 185     const auto isCodingAvailable = [](const QList<QStringView> &list, const QStringView encoding) -> bool
 186     {
 187         for (const QStringView &str : list)
 188         {
 189             if (!str.startsWith(encoding))
 190                 continue;
 191
 192             // without quality values
 193             if (str == encoding)
 194                 return true;
 195
 196             // [rfc7231] 5.3.1. Quality Values
 197             const QStringView substr = str.mid(encoding.size() + 3);  // ex. skip over "gzip;q="
 198
 199             bool ok = false;
 200             const double qvalue = substr.toDouble(&ok);
 201             if (!ok || (qvalue <= 0))
 202                 return false;
 203
 204             return true;
 205         }
 206         return false;
 207     };
 208
 209     const QList<QStringView> list = QStringView(codings.remove(u' ').remove(u'\t')).split(u',', Qt::SkipEmptyParts);
 210     if (list.isEmpty())
 211         return false;
 212
 213     const bool canGzip = isCodingAvailable(list, u"gzip"_s);
 214     if (canGzip)
 215         return true;
 216
 217     const bool canAny = isCodingAvailable(list, u"*"_s);
 218     if (canAny)
 219         return true;
 220
 221     return false;
 222 }