/***************************************************************************
 *   fqterm, a terminal emulator for both BBS and *nix.                    *
 *   Copyright (C) 2008 fqterm development group.                          *
 *                                                                         *
 *   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 St, Fifth Floor, Boston, MA 02110-1301 USA.               *
 ***************************************************************************/

#include <stdlib.h>
#include <ctype.h>

#include <QByteArray>
#include <QTcpSocket>
#include <QProcess>

#include "fqterm.h"
#include "fqterm_socket.h"
#include "fqterm_trace.h"

/* hack from wget/http.c */
#define BASE64_LENGTH(len) (4 * (((len) + 2) / 3))

/* Encode the octets in DATA of length LENGTH to base64 format,
   storing the result to DEST.  The output will be zero-terminated,
   and must point to a writable buffer of at least
   1+BASE64_LENGTH(length) bytes.  The function returns the length of
   the resulting base64 data, not counting the terminating zero.

   This implementation does not emit newlines after 76 characters of
   base64 data.  */

size_t
base64_encode (const void *data, size_t length, char *dest)
{
	/* Conversion table.  */
	static const char tbl[64] = {
		'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
		'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
		'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
		'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/'
	};
	/* Access bytes in DATA as unsigned char, otherwise the shifts below
		don't work for data with MSB set. */
	const unsigned char *s = (const unsigned char *)data;
	/* Theoretical ANSI violation when length < 3. */
	const unsigned char *end = (const unsigned char *) data + length - 2;
	char *p = dest;

	/* Transform the 3x8 bits to 4x6 bits, as required by base64.  */
	for (; s < end; s += 3)
	{
      *p++ = tbl[s[0] >> 2];
      *p++ = tbl[((s[0] & 3) << 4) + (s[1] >> 4)];
      *p++ = tbl[((s[1] & 0xf) << 2) + (s[2] >> 6)];
      *p++ = tbl[s[2] & 0x3f];
	}

	/* Pad the result if necessary...  */
	switch (length % 3)
	{
	case 1:
      *p++ = tbl[s[0] >> 2];
      *p++ = tbl[(s[0] & 3) << 4];
      *p++ = '=';
      *p++ = '=';
      break;
	case 2:
      *p++ = tbl[s[0] >> 2];
      *p++ = tbl[((s[0] & 3) << 4) + (s[1] >> 4)];
      *p++ = tbl[((s[1] & 0xf) << 2)];
      *p++ = '=';
      break;
	}
	/* ...and zero-terminate it.  */
	*p = '\0';

	return p - dest;
}

/* Create the authentication header contents for the `Basic' scheme.
   This is done by encoding the string `USER:PASS' in base64 and
   prepending `HEADER: Basic ' to it.  */
static char *
basic_authentication_encode(const char *user, const char *passwd,
									 const char *header)
{
	char *res;
	int len1 = strlen(user) + 1 +strlen(passwd);
	int len2 = BASE64_LENGTH(len1);

	char t1[len1+1], t2[len2+1];
	sprintf(t1, "%s:%s", user, passwd);
	base64_encode(t1, len1, t2);
	res = (char*)malloc(len2 + 11 + strlen(header));
	sprintf(res, "%s: Basic %s\r\n", header, t2);

	return res;
}

/* Parse the HTTP status line, which is of format:

   HTTP-Version SP Status-Code SP Reason-Phrase

   The function returns the status-code, or -1 if the status line is
   malformed.  The pointer to reason-phrase is returned in RP.  */
static int parse_http_status_line(const char *line, const char
                                  **reason_phrase_ptr) {
	/* (the variables must not be named `major' and `minor', because
		that breaks compilation with SunOS4 cc.)  */
	int mjr, mnr, statcode;
	const char *p;

	*reason_phrase_ptr = NULL;

	/* The standard format of HTTP-Version is: `HTTP/X.Y', where X is
		major version, and Y is minor version.  */
	if (strncmp(line, "HTTP/", 5) != 0) {
		return -1;
	}
	line += 5;

	/* Calculate major HTTP version.  */
	p = line;
	for (mjr = 0; isdigit(*line); line++) {
		mjr = 10 * mjr + (*line - '0');
	}
	if (*line != '.' || p == line) {
		return -1;
	}
	++line;

	/* Calculate minor HTTP version.  */
	p = line;
	for (mnr = 0; isdigit(*line); line++) {
		mnr = 10 * mnr + (*line - '0');
	}
	if (*line != ' ' || p == line) {
		return -1;
	}
	/* Wget will accept only 1.0 and higher HTTP-versions.  The value of
		minor version can be safely ignored.  */
	if (mjr < 1) {
		return -1;
	}
	++line;

	/* Calculate status code.  */
	if (!(isdigit(*line) && isdigit(line[1]) && isdigit(line[2]))) {
		return -1;
	}
	statcode = 100 *(*line - '0') + 10 *(line[1] - '0') + (line[2] - '0');

	/* Set up the reason phrase pointer.  */
	line += 3;
	/* RFC2068 requires SPC here, but we allow the string to finish
		here, in case no reason-phrase is present.  */
	if (*line != ' ') {
		if (! *line) {
			*reason_phrase_ptr = line;
		} else {
			return -1;
		}
	} else {
		*reason_phrase_ptr = line + 1;
	}

	return statcode;
}

const char wingate_enter = 'J' &0x1f;

namespace FQTerm {

//==============================================================================
//FQTermSocketPrivate

//==============================================================================
FQTermSocketPrivate::FQTermSocketPrivate(QObject *parent)
    : QObject(parent) {
  m_socket = new QTcpSocket(this);

  // proxy related
  proxy_type = NOPROXY;
  proxy_state = 0;
  bauth = false;

  FQ_VERIFY(connect(m_socket, SIGNAL(connected()), this, SLOT(socketConnected())));
  FQ_VERIFY(connect(m_socket, SIGNAL(hostFound()), this, SIGNAL(hostFound())));
  FQ_VERIFY(connect(m_socket, SIGNAL(disconnected()), this, SIGNAL(connectionClosed())));

  FQ_VERIFY(connect(m_socket, SIGNAL(readyRead()), this, SLOT(socketReadyRead())));
  FQ_VERIFY(connect(m_socket, SIGNAL(error(QAbstractSocket::SocketError)), this, SIGNAL(error(QAbstractSocket::SocketError))));
}

FQTermSocketPrivate::~FQTermSocketPrivate() {
  delete m_socket;
}

void FQTermSocketPrivate::setProxy(int nProxyType, bool bAuth, const QString &strProxyHost,
                                   quint16 uProxyPort, const QString &strProxyUsr,
                                   const QString &strProxyPwd) {
  proxy_type = nProxyType;
  if (proxy_type == NOPROXY) {
    return ;
  }
  bauth = bAuth;
  proxy_host = strProxyHost;
  proxy_port = uProxyPort;
  proxy_usr = strProxyUsr;
  proxy_pwd = strProxyPwd;
}

void FQTermSocketPrivate::socketConnected() {
  QByteArray strPort;
  QByteArray command(9, 0);

  char *proxyauth;
  char *request;
  int len = 0;

  switch (proxy_type) {
    case NOPROXY:
      // no proxy
      emit connected();
      return ;
    case WINGATE:
      // Wingate Proxy
      strPort.setNum(port);
      writeBlock(host.toLocal8Bit());
      writeBlock(" ");
      writeBlock(strPort);
      writeBlock(&wingate_enter); // CTRL+J
      emit socketState(TSHOSTCONNECTED);
      return ;
    case SOCKS4:
      // Socks4 Proxy
      command.resize(9);
      command[0] = '\x04';
      command[1] = '\x01';
      memcpy(command.data() + 2, &addr_host.sin_port, 2);
      memcpy(command.data() + 4, &addr_host.sin_addr, 4);
      writeBlock(command);
      proxy_state = 1;
      emit socketState(TSPROXYCONNECTED);
      return ;
    case SOCKS5:
      // Socks5 Proxy
      if (bauth) {
        command.resize(4);
        command[0] = '\x05';
        command[1] = '\x02';
        command[2] = '\x02';
        command[3] = '\x00';
        writeBlock(command);
      }
      else {
        command.resize(3);
        command[0] = '\x05';
        command[1] = '\x01';
        command[2] = '\x00';
        writeBlock(command);
      }
      proxy_state = 1;
      emit socketState(TSPROXYCONNECTED);
      return ;
    case HTTP:
      proxyauth = NULL;
      if (bauth) {
        proxyauth = basic_authentication_encode(proxy_usr.toLocal8Bit(),
                                                proxy_pwd.toLocal8Bit(), "Proxy-Authorization");
      }

      len = proxyauth != NULL ? strlen(proxyauth): 0;

      request = new char[host.length() + len + 81];

      sprintf(request, "CONNECT %s:%u HTTP/1.0\r\n""%s\r\n", host.toLatin1().constData(), port,
              proxyauth != NULL ? proxyauth : "");


      writeBlock(request);
      delete [] request;
      free(proxyauth);
      proxy_state = 1;
      emit socketState(TSPROXYCONNECTED);
      return ;
    default:
      emit socketState(TSHOSTCONNECTED);
      return ;
  }
}

void FQTermSocketPrivate::socketReadyRead() {
  if (proxy_type == NOPROXY || proxy_state == 0) {
    emit readyRead();
  }

  int nbytes, nread;
  QByteArray from_socket;
  // get the data size
  nbytes = bytesAvailable();
  if (nbytes <= 0) {
    return ;
  }

  //resize input buffer
  from_socket.resize(0);

  //read data from socket to from_socket
  from_socket = readBlock(nbytes);
  nread = from_socket.size();
  //do some checks
  if (nread <= 0) {
    FQ_TRACE("socket", 0) << "Failed to read socket: " << nread << " <= 0";
    return ;
  }
  if (nread > nbytes) {
    FQ_TRACE("socket", 0) << "Overflow when reading socket: "
                          << " nread = " << nread
                          << " > nbytes = " << nbytes;
    return ;
  }

  // Socks4 Proxy Reply
  if (proxy_type == SOCKS4 && proxy_state == 1) {
    if (nread != 8) {
      emit socketState(TSPROXYERROR);
      return ;
    }

    if (from_socket.at(1) == 90) {
      emit connected();
    } else {
      emit socketState(TSPROXYFAIL);
    }
    proxy_state = 0;
    return ;
  }

  // HTTP Proxy Reply
  if (proxy_type == HTTP && proxy_state != 0) {
    const char *error;
    int statcode = parse_http_status_line(from_socket.data(), &error);
    if (statcode >= 200 && statcode < 300) {
      emit connected();
    } else {
      emit socketState(TSPROXYFAIL);
    }
    proxy_state = 0;
    return ;
  }

  // Socks5 Proxy Reply
  if (proxy_type == SOCKS5 && proxy_state != 0) {
    socks5_reply(from_socket, nread);
    return ;
  }
}

void FQTermSocketPrivate::flush() {
  m_socket->flush();
}

/////////////////////////////////////////////////////
//originally version from qhostaddress.cpp, qt4.3.2, --dp
static bool isIp4(const QString& address)
{
  QStringList ipv4 = address.split(QLatin1String("."));
  if (ipv4.count() != 4)
    return false;

  for (int i = 0; i < 4; ++i) {
    bool ok = false;
    uint byteValue = ipv4.at(i).toUInt(&ok);
    if (!ok || byteValue > 255)
      return false;

  }

  return true;
}
/////////////////////////////////////////////////////////

void FQTermSocketPrivate::connectToHost(const QString &hostname, quint16 portnumber) {
  host = hostname;
  port = portnumber;
  addr_host.sin_port = htons(portnumber);

  if (proxy_type == NOPROXY) {
    m_socket->connectToHost(host, port);
  } else {
    //get ip addr from name
    struct hostent *hostent;
#if defined(_OS_WIN32_) || defined(Q_OS_WIN32)
    WSADATA wsd;
    if (WSAStartup(0x202, &wsd) != 0) {
      emit socketState(TSEINIWINSOCK);
      WSACleanup();
      return ;
    }
#endif
    //    QHostAddress ha(host);
	//ipv4 address check -- dp
	if(isIp4(host)) {
      hostent = gethostbyaddr( host.toLocal8Bit(), host.length(), AF_INET );
	  FQ_TRACE("ssh", 1) << "by addr";
    } else {
      hostent = gethostbyname(host.toLocal8Bit());
	  FQ_TRACE("ssh", 1) << "by name";
    }

    if (hostent == NULL) {
      emit socketState(TSEGETHOSTBYNAME);
      return ;
    }
    //now only ipv4 support
    memcpy(&addr_host.sin_addr, hostent->h_addr, 4);
    m_socket->connectToHost(proxy_host, proxy_port);
  }

}

void FQTermSocketPrivate::close() {
  m_socket->close();
}

QByteArray FQTermSocketPrivate::readBlock(unsigned long maxlen) {
  return m_socket->read(maxlen);
}

long FQTermSocketPrivate::writeBlock(const QByteArray &data) {
  return m_socket->write(data);
}

unsigned long FQTermSocketPrivate::bytesAvailable() {
  return m_socket->bytesAvailable();
}

/*------------------------------------------------------------------------
 * connect command for socks5
 *------------------------------------------------------------------------
 */
void FQTermSocketPrivate::socks5_connect() {
  QByteArray command(10, 0);
  command[0] = '\x05';
  command[1] = '\x01';
  command[2] = '\x00';
  command[3] = '\x01';
  memcpy(command.data() + 4, &addr_host.sin_addr, 4);
  memcpy(command.data() + 8, &addr_host.sin_port, 2);
  writeBlock(command);
}

/*------------------------------------------------------------------------
 * authentation command for socks5
 *------------------------------------------------------------------------
 */
void FQTermSocketPrivate::socks5_auth() {
  int ulen = proxy_usr.length();
  int plen = proxy_pwd.length();
  QByteArray command(3+ulen + plen, 0);
  sprintf((char*)command.data(), "  %s %s", proxy_usr.toLocal8Bit().data(),
          proxy_pwd.toLocal8Bit().data());
  command[0] = '\x01';
  command[1] = ulen;
  command[2+ulen] = plen;
  writeBlock(command);
}

/*------------------------------------------------------------------------
 * reply  from socks5
 *------------------------------------------------------------------------
 */
void FQTermSocketPrivate::socks5_reply(const QByteArray &from_socket, int nread) {
  if (proxy_state == 1) { // Socks5 Proxy Replay 1
    if (nread != 2) {
      proxy_state = 0;
      emit socketState(TSPROXYERROR);
      return ;
    }
    switch (from_socket.at(1)) {
      case '\x00':
        // no authentation needed
        socks5_connect();
        proxy_state = 3;
        emit socketState(TSCONNECTVIAPROXY);
        return ;
      case '\x02':
        //need user/password
        socks5_auth();
        proxy_state = 2;
        emit socketState(TSPROXYAUTH);
        return ;
      case '\xff':
        proxy_state = 0;
        emit socketState(TSPROXYFAIL);
        return ;
      default:
        proxy_state = 0;
        emit socketState(TSPROXYFAIL);
        return ;
    }
  } else if (proxy_state == 2) { //Socks5 Proxy Replay 2
    if (nread != 2) {
      proxy_state = 0;
      emit socketState(TSPROXYERROR);
      return ;
    }


    if (from_socket.at(1) != '\00') {
      proxy_state = 0;
      emit socketState(TSPROXYFAIL);
      return ;
    }
    socks5_connect();
    proxy_state = 3;
    emit socketState(TSCONNECTVIAPROXY);
    return ;
  } else if (proxy_state == 3) { //Socks5 Proxy Replay 3
    proxy_state = 0;
    if (nread != 10) {
      emit socketState(TSPROXYERROR);
      return ;
    }
    if (from_socket.at(1) != '\00') {
      emit socketState(TSPROXYFAIL);
      return ;
    }
    emit connected();
    return ;
  } else {
    proxy_state = 0;
    return ;
  }
}


}  // namespace FQTerm

#include "fqterm_socket_private.moc"