Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.

BUG:215923


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdelibs@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 1110 insertions, 0 deletions

diff --git a/kdecore/kextsock.h b/kdecore/kextsock.h
new file mode 100644
index 000000000..f3d1f5923
--- /dev/null
+++ b/kdecore/kextsock.h
@@ -0,0 +1,1110 @@
+/*
+ *  This file is part of the KDE libraries
+ *  Copyright (C) 2000-2004 Thiago Macieira <thiago.macieira@kdemail.net>
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library 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
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public License
+ *  along with this library; see the file COPYING.LIB.  If not, write to
+ *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA 02110-1301, USA.
+ */
+#ifndef KEXTSOCK_H
+#define KEXTSOCK_H
+
+#include "kdelibs_export.h"
+
+#ifdef Q_OS_UNIX
+
+#include <sys/time.h>
+
+#include <qstring.h>
+#include <qptrlist.h>
+#include <qiodevice.h>
+
+#include "kbufferedio.h"
+#include "ksockaddr.h"
+
+/* External reference to netdb.h */
+struct addrinfo;
+struct kde_addrinfo;
+class KAddressInfo;		/* our abstraction of it */
+class QSocketNotifier;
+
+/*
+ * This is extending QIODevice's error codes
+ *
+ * According to qiodevice.h, the last error is IO_UnspecifiedError
+ * These errors will never occur in functions declared in QIODevice
+ * (except open, but you shouldn't call open)
+ */
+#define IO_ListenError		(IO_UnspecifiedError+1)
+#define IO_AcceptError		(IO_UnspecifiedError+2)
+#define IO_LookupError		(IO_UnspecifiedError+3)
+
+class KExtendedSocketPrivate;
+/**
+ * The extended socket class.
+ *
+ * This class should be used instead of KSocket whenever the user needs
+ * fine-grained control over the socket being created. Unlike KSocket, which
+ * does everything at once, without much intervention, KExtendedSocket allows
+ * intervention at every step of the process and the setting of parameters.
+ *
+ * This class allows for the creation of both server and client sockets. The
+ * only difference is that the passiveSocket flag must be passed either to
+ * the constructor or to setSocketFlags(). If passiveSocket is used, the class will
+ * enable functions listen() and accept() and related signals, and will
+ * also disable readBlock() and writeBlock().
+ *
+ * To create a Unix socket, one would pass flag unixSocket to the constructor
+ * or setSocketFlags(). The hostname and service/port can be set to whatever is
+ * necessary. If no hostname is given, but a service/port is, the socket created
+ * will be implementation dependant (usually in /tmp). In any other case, the
+ * fields will be concatenated.
+ *
+ * To create an Internet socket, inetSocket flag can be used. If, on the other
+ * hand a specific IP protocol is desired, ipv4Socket and/or ipv6Socket can be
+ * used.
+ *
+ * Note that the socket type selection flags are cumulative. One could select
+ * Unix and Internet sockets by using unixSocket | inetSocket. Or, for instance,
+ * to make sure only IPv4 and IPv6 sockets are selected, even if future implementations
+ * support newer IP protocols, ipv4Socket | ipv6Socket is your guy.
+ *
+ * @deprecated
+ *	This class is now deprecated. Please use the classes in KNetwork for
+ *	new programs. In particular, this class is replaced by KNetwork::KStreamSocket
+ *	and @ref KNetwork::KServerSocket.
+ *
+ * @author Thiago Macieira <thiago.macieira@kdemail.net>
+ * @short an extended socket
+ */
+class KDECORE_EXPORT KExtendedSocket: public KBufferedIO // public QObject, public QIODevice
+{
+  Q_OBJECT
+
+public:
+  /**
+   * flags that can be passed down to the member functions
+   */
+  enum Flags
+  {
+    /* socket address families */
+    /*
+     * NOTE: if you change this, you have to change function valid_socket() as well
+     * These values are hard coded!
+     */
+    anySocket = 0x00,
+    knownSocket = 0x01,
+    unixSocket = knownSocket | 0x02,
+    inetSocket = knownSocket | 0x04,
+    ipv4Socket = inetSocket | 0x100,
+    ipv6Socket = inetSocket | 0x200,
+
+    passiveSocket = 0x1000,	/* passive socket (i.e., one that accepts connections) */
+    canonName = 0x2000,		/* request that the canon name be found */
+    noResolve = 0x4000,		/* do not attempt to resolve, treat as numeric host */
+
+    streamSocket = 0x8000,	/* request a streaming socket (e.g., TCP) */
+    datagramSocket = 0x10000,	/* request a datagram socket (e.g., UDP) */
+    rawSocket = 0x20000,	/* request a raw socket. This probably requires privileges */
+
+    inputBufferedSocket = 0x200000, /* buffer input in this socket */
+    outputBufferedSocket = 0x400000, /* buffer output in this socket */
+    bufferedSocket = 0x600000	/* make this a fully buffered socket */
+  };
+
+  /**
+   * status of the class
+   * The status are sequential. If a change to one status is requested,
+   * all the prior status will be passed and their actions, performed
+   */
+  enum SockStatus
+  {
+    // the numbers are scattered so that we leave room for future expansion
+    error = -1,			// invalid status!
+
+    nothing = 0,		// no status, the class has just been created
+
+    lookupInProgress = 50,	// lookup is in progress. Signals will be sent
+    lookupDone = 70,		// lookup has been done. Flags cannot be changed
+				// from this point on
+
+    created = 100,		// ::socket() has been called, a socket exists
+    bound = 140,		// socket has been bound
+
+    connecting = 200,		// socket is connecting (not passiveSocket)
+    connected = 220,		// socket has connected (not passiveSocket)
+
+    listening = 200,		// socket is listening (passiveSocket)
+    accepting = 220,		// socket is accepting (passiveSocket)
+
+    closing = 350,		// socket is closing (delayed close)
+
+    done = 400			// socket has been closed
+  };
+
+public:
+  /**
+   * Creates an empty KExtendedSocket.
+   */
+  KExtendedSocket();
+
+  /**
+   * Creates a socket with the given hostname and port.
+   *
+   * If this is a connecting (active) socket, the hostname and port specify
+   * the remote address to which we will connect.
+   *
+   * If this is a listening (passive) socket, the hostname and port specify
+   * the address to listen on. In order to listen on every interface
+   * available on this node, set @p host to QString::null. To let the operating
+   * system select a port, set it to 0.
+   *
+   * @sa setAddress
+   * @param host	the hostname
+   * @param port	the port number
+   * @param flags	flags
+   */
+  KExtendedSocket(const QString& host, int port, int flags = 0);
+
+  /**
+   * Creates a socket with the given hostname and service.
+   *
+   * If this is a connecting (active) socket, the hostname and service specify
+   * the remote address to which we will connect.
+   *
+   * If this is a listening (passive) socket, the hostname and service specify
+   * the address to listen on. In order to listen on every interface
+   * available on this node, set @p host to QString::null. To let the operating
+   * system select a port, set the service to "0".
+   *
+   * @sa setAddress
+   * @param host	the hostname
+   * @param service	the service
+   * @param flags	flags
+   */
+  KExtendedSocket(const QString& host, const QString& service, int flags = 0);
+
+  /**
+   * Destroys the socket, disconnecting if still connected and
+   * freeing any related resources still being kept.
+   */
+  virtual ~KExtendedSocket();
+
+  /**
+   * Resets the socket, disconnecting if still connected and
+   * freeing any related resources still being kept.
+   * @since 3.1
+   */
+  void reset();
+
+  /*
+   * --- status, flags and internal variables --- *
+   */
+
+  /**
+   * Returns the class status.
+   * @return the class status
+   * @see ::SockStatus
+   */
+  int socketStatus() const;
+
+  /**
+   * Returns the related system error code
+   * Except for IO_LookupError errors, these are codes found in
+   * errno
+   * @return the system error code
+   */
+  int systemError() const;
+
+  /**
+   * Sets the given flags.
+   * @param flags	the flags to be set
+   * @return the new flags status, or -1 if flags can no longer be set
+   */
+  int setSocketFlags(int flags);
+
+  /**
+   * Returns the current flags
+   * @return the current flags
+   * @see ::Flags
+   */
+  int socketFlags() const;
+
+  /**
+   * Sets the hostname to the given value. 
+   *
+   * If this is a listening (passive) socket, the hostname is the host to which the socket
+   * will bind in order to listen. If you want to listen in every interface, set it
+   * to "*" or QString::null.
+   *
+   * If this is a connecting (active) socket, the hostname is the host to which we will try
+   * to connect.
+   *
+   * @param host	the hostname
+   * @return true on success, false on error
+   */
+  bool setHost(const QString& host);
+
+  /**
+   * Returns the hostname.
+   * @return the hostname or QString::null if no host has been set
+   */
+  QString host() const;
+
+  /**
+   * Sets the port/service.
+   * @param port	the port
+   */
+  bool setPort(int port);
+
+  /**
+   * Sets the port/service.
+   *
+   * In the case of Unix-domain sockets, the port is the filename for the socket.
+   * If the name is not an absolute path, "/tmp/" will be prepended.
+   *
+   * @param port	the port
+   * @return true if successful, false on error (e.g. connection already established)
+   */
+  bool setPort(const QString& port);
+
+  /**
+   * Returns the port/service. If it is a port, the string contains a number.
+   * @return the port or QString::null if it has not been set.
+   */
+  QString port() const;
+
+  /**
+   * Sets the address where we will connect to.
+   *
+   * See @ref setHost and @ref setPort for information on the parameters.
+   *
+   * @param host	the hostname
+   * @param port	port number
+   * @return true if successful, false on error (e.g. connection already established)
+   */
+  bool setAddress(const QString& host, int port);
+
+  /**
+   * Sets the address where we will connect to.
+   *
+   * See @ref setHost and @ref setPort for information on the parameters.
+   *
+   * @param host	the hostname
+   * @param serv	the service
+   * @return true if successful, false on error (e.g. connection already established)
+   */
+  bool setAddress(const QString& host, const QString& serv);
+
+  /**
+   * Sets the hostname to which we will bind locally before connecting.
+   * @param host	the hostname
+   * @return false if this is a passiveSocket, otherwise true.
+   */
+  bool setBindHost(const QString& host);
+
+  /**
+   * Unsets the bind hostname. That is, don't request a binding host.
+   * @return true if successful, false on error (e.g. connection already established)
+   */
+  bool unsetBindHost();
+
+  /**
+   * Returns the hostname to which the socket will be/is bound.
+   * @return the host or QString::null if it has not been set.
+   */
+  QString bindHost() const;
+
+  /**
+   * Sets the port/service to which we will bind before connecting
+   * @param port	the port number
+   * @return true if successful, false on error (e.g. connection already established)
+   */
+  bool setBindPort(int port);
+
+  /**
+   * Sets the port/service to which we will bind before connecting.
+   * @param service	the port number or service name
+   * @return true if successful, false on error (e.g. connection already established)
+   */
+  bool setBindPort(const QString& service);
+
+  /**
+   * Unsets the bind port/service.
+   * @return true if successful, false on error (e.g. connection already established)
+   */
+  bool unsetBindPort();
+
+  /**
+   * Returns the service to which the socket will be/is bound.
+   * @return the host or QString::null if it has not been set.
+   */
+  QString bindPort() const;
+
+  /**
+   * Sets both host and port to which we will bind the socket. Will return
+   * false if this is a passiveSocket.
+   * @param host	the hostname
+   * @param port	the port number
+   * @return true if successful, false on error (e.g. connection already established)
+   */
+  bool setBindAddress(const QString& host, int port);
+
+  /**
+   * Sets both host and service to which we will bind the socket. Will return
+   * false if this is a passiveSocket.
+   * @param host	the hostname
+   * @param service	the service
+   * @return true if successful, false on error (e.g. connection already established)
+   */
+  bool setBindAddress(const QString& host, const QString& service);
+
+  /**
+   * Unsets the bind address for the socket. That means that we won't
+   * attempt to bind to an address before connecting.
+   * @return true if successful, false on error (e.g. connection already established)
+   */
+  bool unsetBindAddress();
+
+  /**
+   * Sets the timeout value for the connection (if this is not passiveSocket) or
+   * acception (if it is). In the event the given function
+   * (connect or accept) returns due to time out, it's possible to call it again.
+   *
+   * Setting the timeout to 0 disables the timeout feature.
+   *
+   * @param secs	the timeout length, in seconds
+   * @param usecs	the timeout complement, in microseconds
+   * @return false if setting timeout makes no sense in the context.
+   */
+  bool setTimeout(int secs, int usecs = 0);
+
+  /**
+   * Returns the timeout value for the connection.
+   * @return the timeout value. 0 if there is no timeout.
+   */
+  timeval timeout() const;
+
+  /**
+   * Sets/unsets blocking mode for the socket. When non-blocking mode is enabled,
+   * I/O operations might return error and set errno to EWOULDBLOCK. Also,
+   * it's not recommended to use this when using the class signals.
+   *
+   * @param enable	if true, set blocking mode. False, non-blocking mode.
+   * @return false on error.
+   */
+  bool setBlockingMode(bool enable);
+
+  /**
+   * Returns the current blocking mode for this socket.
+   * @return true if in blocking mode
+   */
+  bool blockingMode();
+
+  /**
+   * Sets/unsets address reusing flag for this socket.
+   *
+   * This function returns true if the value was set correctly. That is NOT
+   * the result of the set.
+   * @param enable	if true, set address reusable
+   * @return true on success, false on failure. If the socket was not yet created,
+   * the value is only remembered. In this case the return value is always true.
+   */
+  bool setAddressReusable(bool enable);
+
+  /**
+   * Returns whether this socket's address can be reused
+   * @return true if the address can be reused
+   */
+  bool addressReusable();
+
+  /**
+   * Sets/unsets the v6-only flag for IPv6 sockets.
+   *
+   * When an IPv6 socket is in use, communication with IPv4 sockets is
+   * guaranteed by translating those IPv4 addresses into IPv6 ones
+   * (specifically, the v4-mapped addresses). This flag allows that
+   * behavior to be turned on and off.
+   *
+   * Note that this does not have any effect on sockets that are not
+   * IPv6 and the function will always return false in those cases.
+   * Also note that this flag defaults to off in order to accommodate
+   * existing applications.
+   *
+   * @param enable	if true, no IPv4 translation will be performed;
+   *			this socket will be restricted to IPv6 communication
+   * @returns true on success, false on failure.
+   * @see localAddress to find out if this is an IPv6 socket
+   */
+  bool setIPv6Only(bool enable);
+
+  /**
+   * Returns the status of the v6-only flag for IPv6 sockets.
+   * @returns true if the flag is set to on; false if it is not. If this
+   * socket is not an IPv6 one, the return value is false.
+   * @see setIPv6Only
+   */
+  bool isIPv6Only();
+
+  /**
+   * Sets the buffer sizes for this socket.
+   *
+   * This implementation allows any size for both parameters. The value given
+   * will be interpreted as the maximum size allowed for the buffers, after
+   * which the I/O functions will stop buffering. The value of -1 will be
+   * interpreted as "unlimited" size. The value of -2 means "no change".
+   *
+   * Note: changing the buffer size to 0 for any buffer will cause the given
+   * buffer's to be discarded. Likewise, setting the size to a value less than
+   * the current size will cause the buffer to be shrunk to the wanted value,
+   * as if the data had been read.
+   * @param rsize	read buffer size
+   * @param wsize	write buffer size
+   * @return true on success, false if this is not possible in this state (e.g. connection
+   *         not established yet)
+   */
+  virtual bool setBufferSize(int rsize, int wsize = -2);
+
+  /**
+   * Returns the local socket address
+   * @return the local socket address, can be 0 if the connection has not been established
+   *         yet
+   */
+  const ::KSocketAddress *localAddress();
+
+  /**
+   * Returns the peer socket address. Use KExtendedSocket::resolve() to
+   * resolve this to a human-readable hostname/service or port.
+   * @return the peer address, can be 0 if the connection has not been established yet
+   *         or the socket is passive
+   */
+  const ::KSocketAddress *peerAddress();
+
+  /**
+   * Returns the file descriptor
+   * @return the file descriptor. -1 if there is no fd yet.
+   */
+  inline int fd() const
+  { return sockfd; }
+
+  /*
+   * -- socket creation -- *
+   */
+
+  /**
+   * Performs lookup on the addresses we were given before.
+   *
+   * This will perform lookups on the bind addresses if they were given.
+   * @return 0 or an error. Do not rely on the values returned by lookup
+   * as of now. They are not specified.
+   */
+  virtual int lookup();
+
+  /**
+   * Starts an asynchronous lookup for the addresses given.
+   *
+   * When the lookup is done, the lookupReady signal will be emitted.
+   *
+   * Note that, depending on the parameters for the lookup, this function might
+   * know the results without the need for blocking or queuing an
+   * asynchronous lookup. That means that the lookupReady signal might be
+   * emitted by this function, so your code should be prepared for that.
+   *
+   * One such case is when noResolve flag is set.
+   * If this function is able to determine the results without queuing
+   * and the lookup failed, this function will return -1.
+   *
+   * @return 0 on success or -1 on error. Note that
+   * returning 0 means that either we are in the process of doing
+   * lookup or that it has finished already.
+   */
+  virtual int startAsyncLookup();
+
+  /**
+   * Cancels any on-going asynchronous lookups
+   */
+  virtual void cancelAsyncLookup();
+
+  /**
+   * Place the socket in listen mode. The parameters are the same as for
+   * the system listen() call.
+   * @param N		the queue length for pending connections
+   * @return 0 on success, -1 on system error (errno
+   *         available) and -2 if this is not a passiveSocket.
+   */
+  virtual int listen(int N = 5); // 5 is arbitrary
+
+  /**
+   * Accepts an incoming connection from the socket. If this socket is in
+   * blocking mode, this function will block until a connection is received.
+   * Otherwise, it might return with error. The sock parameter will be
+   * initialised with the newly created socket.
+   *
+   * Upon successful acception (i.e., this function returns 0), the newly
+   * created socket will be already connected. The socket will be unbuffered
+   * and readyRead() and readyWrite() signals will be disabled.
+   *
+   * @param sock	a pointer to an KExtendedSocket variable
+   * @return 0 on success, -1 on system error (errno set) and -2 if this is
+   * not a passiveSocket and -3 if this took too long (time out)
+   */
+  virtual int accept(KExtendedSocket *&sock);
+
+  /**
+   * Attempts to connect to the remote host.
+   * After successful connection (return value 0), the socket will be ready
+   * for I/O operations. Note, however, that not all signals may be enabled
+   * for emission by this socket:
+   * @li readyRead and readyWrite signals will be enabled only if
+   * enableRead or enableWrite were called. You can still enable
+   *    them by calling those functions, of course.
+   * @li #closed() will only be sent if we are indeed reading from the input
+   *    stream. That is, if this socket is buffering the input. See setBufferSize
+   *
+   * Note that, in general, functions inherited/overridden from KBufferedIO will only
+   * work on buffered sockets, like bytesAvailable and bytesToWrite.
+   * @return    The return values are:
+   * @li 0: success
+   * @li -1: system error, errno was set accordingly
+   * @li -2: this socket cannot connect(); this is a passiveSocket. It can also
+   *   mean that the function was unable to make a connection with the given
+   *   bind address or that an asynchronous connection attempt is already
+   *   in progress.
+   * @li -3: connection timed out
+   *
+   */
+  virtual int connect();
+
+  /**
+   * Starts an asynchronous connect. This works exactly the same as #connect,
+   * except that the connection result won't be returned.
+   *
+   * Note that those signals might be emitted before this function returns, so your
+   * code should be prepared for that condition.
+   *
+   * You must call cancelAsyncConnect() before you delete the socket if you
+   * call this.  Otherwise you will have crashes.
+   *
+   * @return 0 on successful queuing of the connect or -1 on error.
+   *         If this function returns 0, then the connectionSuccess() or the
+   * connectionFailed() signals will be emitted.
+   */
+  virtual int startAsyncConnect();
+
+  /**
+   * Cancels any on-going asynchronous connection attempt.
+   */
+  virtual void cancelAsyncConnect();
+
+  /**
+   * Implementation of QIODevice::open() pure virtual function.
+   * This depends on the target host address already being there.
+   * If this is a passiveSocket, this is identical to call listen(); else, if
+   * this is not a passiveSocket and no connection attempt is in progress, this
+   * is like connect(). If one is in progress, this function will fail.
+   * @param mode the open mode. Must be IO_Raw | IO_ReadWrite
+   * @return true if successful, false when an error occurred or the most was
+   *         not correct
+   */
+  virtual bool open(int mode = IO_Raw | IO_ReadWrite);
+
+  /**
+   * Closes the socket. If we have data still in the write buffer yet to be
+   * sent, the socket won't be closed right now. It'll be closed after we managed
+   * to send everything out.
+   * If you want to close the socket now, you may want to call flush() first,
+   * and then closeNow().
+   */
+  virtual void close();
+
+  /**
+   * Closes the socket now, discarding the contents of the write buffer, if any.
+   * The read buffer's contents are kept until they are emptied by read operations
+   * or the class is destroyed.
+   */
+  virtual void closeNow();
+
+  /**
+   * Releases the socket and anything we have holding on it. The class cannot
+   * be used anymore. In other words, this is just like closeNow(), but it does
+   * not actually close the socket.
+   *
+   * This is useful if you just want to connect and don't need the rest of the
+   * class.
+   *
+   * Note that the buffers' contents will be discarded.
+   *
+   * Use of this method is discouraged, because the socket created might be such that
+   * normal library routines can't handle (read, write, close, etc.)
+   */
+  virtual void release();
+
+  /*
+   * -- I/O --
+   */
+
+  /**
+   * Flushes the socket buffer. You need not call this method during normal
+   * operation as we will try and send everything as soon as possible.
+   * However, if you want to make sure that data in the buffer is being sent
+   * at this moment, you can call this function. It will try to send as much
+   * data as possible, but it will stop as soon as the kernel cannot receive
+   * any more data, and would possibly block.
+   *
+   * By repeatedly calling this function, the behavior will be like that of
+   * a blocking socket. Indeed, if this function is called with the kernel not
+   * ready to receive data, it will block, unless this is a non-blocking socket.
+   *
+   * This function does not touch the read buffer. You can empty it by calling
+   * readBlock() with a null destination buffer.
+   */
+  virtual void flush();
+
+  /**
+   * Returns length of this socket. This call is not supported on sockets.
+   * @return the length of this socket, or 0 if unsupported
+   */
+  virtual inline Q_ULONG size() const
+  { return 0; }
+
+  /**
+   * Returns relative position from start. This call is not supported on sockets.
+   * @return the relative position from the start, or 0 if unsupported
+   */
+  virtual inline Q_ULONG at() const
+  { return 0; }
+
+  /**
+   * Returns true if we are at position. This is not supported on sockets.
+   * @param i the position to check
+   * @return true if we art at the given position, or always true if unsupported.
+   */
+  virtual inline bool at(int i)
+  { Q_UNUSED(i);return true; }
+
+  /**
+   * Returns true if we are at the end. This is not supported on sockets, but
+   * we always are at the end in a socket...
+   * @return true if we are at the end. Always false if unsupported.
+   */
+  virtual inline bool atEnd() const
+  { return false; }
+
+  /**
+   * Reads a block of data from the socket.
+   *
+   * If the socket is not buffered, this function will simply call the underlying
+   * read method. This function will block if the socket is not on non-blocking mode
+   * (see setBlockingMode) and there is not enough data to be read in the
+   * Operating System yet. If we are in non-blocking operation, the call will
+   * fail in this case.
+   *
+   * However, if we are buffering, this function will instead read from the
+   * buffer while there is available data. This function will never block
+   * in buffering mode, which means that if you try to read while the buffers
+   * are empty, this function will always return -1 and set the system error to
+   * EWOULDBLOCK (aka EAGAIN), so as to mimic non-blocking operation.
+   *
+   * @param data	where we will write the read data to
+   * @param maxlen	maximum length of data to be read
+   * @return the number of bytes effectively read, or a negative number in case
+   * or an error. If the @p data param is not null, then this is also the number
+   * of bytes copied into that buffer. If the return value is different than
+   * @p maxlen, then this function encountered a situation in which no more
+   * bytes were available. Subsequent calls might cause this function to one
+   * of these behaviours:
+   * @li return an error, with EWOULDBLOCK system error, if we buffering
+   *   or we are in non-blocking mode
+   * @li otherwise, it'll block
+   * This function returns 0, if the function detected end-of-file condition
+   * (socket was closed)
+   */
+  virtual Q_LONG readBlock(char *data, Q_ULONG maxlen);
+
+  /**
+   * Writes a block of data to the socket.
+   *
+   * If the socket is not buffered, this function will simply call the underlying
+   * write method. This means that the function might block if that method blocks
+   * as well. That situation is possible if we are not in non-blocking mode and
+   * the operating system buffers are full for this socket. If we are in
+   * non-blocking mode and the operating system buffers are full, this function
+   * will return -1 and the system error will be set to EWOULDBLOCK.
+   *
+   * If we are buffering, this function will simply transfer the data into the
+   * write buffer. This function will then always succeed, as long as there is
+   * enough room in the buffer. If the buffer size was limited and that limit
+   * is reached, this function will copy no more bytes than that limit. Trying
+   * to write with a full buffer will return -1 and set system error to
+   * EWOULDBLOCK.
+   *
+   * @param data	the data to write
+   * @param len		the length of data to write
+   * @return the number of bytes written from @p data buffer.
+   * The return value might be less than @p len if the output buffers cannot
+   * accommodate that many bytes and -1 in the case of an errro.
+   */
+  virtual Q_LONG writeBlock(const char *data, Q_ULONG len);
+
+  /**
+   * Peeks at a block of data from the socket.
+   *
+   * This is exactly like read, except that the data won't be flushed from the
+   * read buffer.
+   *
+   * If this socket is not buffered, this function will always return with
+   * 0 bytes copied.
+   *
+   * @param data	where to store the data
+   * @param maxlen	how many bytes to copy, at most
+   * @return the number of bytes copied. 0 does not mean end-of-file
+   *         condition.
+   */
+  virtual int peekBlock(char *data, uint maxlen);
+
+  /**
+   * Reimplementation of unreadBlock() method. This is so because unreading in
+   * sockets doesn't make sense, so this function will always return -1 (error)
+   * and set the system error to ENOSYS.
+   * @return always -1 (error)
+   */
+  virtual int unreadBlock(const char *data, uint len);
+
+  /**
+   * Returns the number of available bytes yet to be read via readBlock
+   * and family of functions.
+   *
+   * Note: as of now, this only works on input-buffered sockets. This will
+   * change in the future
+   * @return The number of available bytes, or -1 on error or -2 if this call is invalid
+   * in the current state.
+   */
+  virtual int bytesAvailable() const;
+
+  /**
+   * Waits @p msec milliseconds for more data to be available (use 0 to
+   * wait forever). The return value is the amount of data available for
+   * read in the read buffer.
+   *
+   * @param msec	milliseconds to wait
+   * @return -1 in case of system error and -2 in case of invalid socket
+   *         state
+   */
+  virtual int waitForMore(int msec);
+
+  /**
+   * Gets a single character (unsigned char) from the stream.
+   * @return the value of the character. Negative if there was an error.
+   */
+  virtual int getch();
+
+  /**
+   * Writes a single character (unsigned char) to the stream. All other bits
+   * will be ignored.
+   * @param ch	character to write, converted to char
+   */
+  virtual int putch(int ch);
+
+  /**
+   * Unreads one character from the stream. This is not possible on sockets.
+   * @return always returns -1 on sockets.
+   */
+  virtual int ungetch(int)
+  { return -1; }
+
+  /**
+   * Toggles the emission of the readyRead signal.
+   *
+   * Note that this signal is emitted every time more data is available to be
+   * read, so you might get flooded with it being emitted every time, when in
+   * non-buffered mode. However, in buffered mode, this signal will be
+   * emitted only when there is data coming in from the wire.
+   * By default, this flag is set to false, i.e., signal not being emitted.
+   * @param enable	if true, the signal will be emitted
+   */
+  virtual void enableRead(bool enable);
+
+  /**
+   * Toggles the emission of the readyWrite signal.
+   *
+   * Note that this signal is emitted only when the OS is ready to receive more
+   * data, which means that the write buffer is empty. And when that is reached,
+   * this signal will possibly be emitted on every loop, so you might
+   * want to disable it. By default, this flag is set to false.
+   * @param enable	if true, the signal will be emitted
+   */
+  virtual void enableWrite(bool enable);
+
+signals:
+  /**
+   * This signal is emitted whenever an asynchronous lookup process is done.
+   * The parameter @p count tells
+   * @param count the number of results
+   */
+  void lookupFinished(int count);
+
+  /**
+   * This signal is emitted whenever we connected asynchronously to a host.
+   */
+  void connectionSuccess();
+
+  /**
+   * This signal is emitted whenever our asynchronous connection attempt
+   * failed to all hosts listed.
+   * @param error	the errno code of the last connection attempt
+   */
+  void connectionFailed(int error);
+
+  /**
+   * This signal is emitted whenever this socket is ready to accept another
+   * socket.
+   * @see accept()
+   */
+  void readyAccept();
+
+protected:
+  int sockfd;			// file descriptor of the socket
+
+protected slots:
+
+  void socketActivityRead();
+  void socketActivityWrite();
+  void dnsResultsReady();
+  void startAsyncConnectSlot();
+  void connectionEvent();
+
+protected:
+
+  QSocketNotifier *readNotifier();
+  QSocketNotifier *writeNotifier();
+
+private:
+
+  // protection against accidental use
+  KExtendedSocket(KExtendedSocket&);
+  KExtendedSocket& operator=(KExtendedSocket&);
+
+  /**
+   * This is actually a wrapper around getaddrinfo().
+   * @internal
+   */
+  static int doLookup(const QString& host, const QString& serv, addrinfo& hint,
+		      kde_addrinfo** result);
+
+protected:
+  /**
+   * Sets the error code
+   */
+  void setError(int errorkind, int error);
+
+  inline void cleanError()
+  { setError(IO_Ok, 0); }
+
+  /**
+   * Sets the socket status. For derived classes only.
+   */
+  void setSocketStatus(int status);
+
+public:
+  /**
+   * Performs resolution on the given socket address.
+   *
+   * That is, tries to resolve the raw form of the socket address into a textual
+   * representation.
+   *
+   * @param sock	the socket address
+   * @param len         the length of the socket address
+   * @param host	where the hostname will be written
+   * @param port	where the service-port will be written
+   * @param flags	the same flags as getnameinfo()
+   * @returns 0 on success, nonzero otherwise.
+   */
+  static int resolve(sockaddr* sock, ksocklen_t len, QString& host, QString& port, int flags = 0) KDE_DEPRECATED;
+
+  /**
+   * Performs resolution on the given socket address.
+   *
+   * That is, tries to resolve the raw form of the socket address into a textual
+   * representation.
+   *
+   * @param sock	the socket address
+   * @param host	where the hostname will be written
+   * @param port	where the service-port will be written
+   * @param flags	the same flags as getnameinfo()
+   * @returns 0 on success, nonzero otherwise.
+   */
+  static int resolve(::KSocketAddress* sock, QString& host, QString& port, int flags = 0) KDE_DEPRECATED;
+
+  /** @deprecated
+   * This function is now deprecated. Please use @ref KNetwork::KResolver::resolve.
+   *
+   * Performs lookup on the given hostname/port combination and returns a list
+   * of matching addresses.
+   * The error code can be transformed into string by KExtendedSocket::strError()
+   * with code of IO_LookupError.
+   *
+   * IMPORTANT: the result values of the QPtrList must be deleted after use. So,
+   * if you don't copy the KAddressInfo objects, the best way to assure that
+   * is to call setAutoDelete(true) on the list right after this function
+   * returns. If you do copy the results out, you must assure that the objects
+   * get deleted when they are not needed any more.
+   *
+   * @param host	the hostname to look up
+   * @param port	the port/service to look up
+   * @param flags	flags to be used when looking up, Flags
+   * @param error	pointer to a variable holding the error code
+   * @return a list of KAddressInfos
+   */
+  static QPtrList<KAddressInfo> lookup(const QString& host, const QString& port, int flags = 0, int *error = 0) KDE_DEPRECATED;
+
+  /**
+   * Returns the local socket address
+   * Remember to delete the returned object when it is no longer needed.
+   * @param fd		the file descriptor
+   * @return the local socket address or 0 if an error occurred. Delete after use.
+   */
+  static ::KSocketAddress *localAddress(int fd) KDE_DEPRECATED;
+
+  /**
+   * Returns the peer socket address. Use KExtendedSocket::resolve() to
+   * resolve this to a human-readable hostname/service or port.
+   * Remember to delete the returned object when it is no longer needed.
+   * @param fd		the file descriptor
+   * @return the peer socket address or 0 if an error occurred. Delete after use.
+   */
+  static ::KSocketAddress *peerAddress(int fd) KDE_DEPRECATED;
+
+  /**
+   * Returns the representing text of this error code
+   * @param code	the error code, as seen in status()
+   * @param syserr	the system error, as from systemError()
+   * @return the text for the given error code
+   */
+  static QString strError(int code, int syserr);
+
+  /**
+   * Sets/unsets address reusing flag for this socket.
+   *
+   * This function returns true if the value was set correctly. That is NOT
+   * the result of the set.
+   * @param fd	the file descriptor
+   * @param enable	if true, set address reusable
+   * @return true on success, false on failure.
+   */
+  static bool setAddressReusable(int fd, bool enable) KDE_DEPRECATED;
+
+protected:
+  virtual void virtual_hook( int id, void* data );
+private:
+  KExtendedSocketPrivate *d;
+
+  friend class KSocket;
+  friend class KServerSocket;
+};
+
+/** @deprecated
+ * This class is now deprecated. Please see @ref KNetwork::KResolver for the new API.
+ *
+ * Contains information about an internet address. It wraps addrinfo,
+ * see getaddrinfo(3) for more information.
+ */
+class KDECORE_EXPORT KAddressInfo
+{
+private:
+  addrinfo *ai;
+  ::KSocketAddress *addr;
+
+  inline KAddressInfo() : ai(0), addr(0)
+  { }
+
+  //  KAddressInfo(addrinfo *ai);
+  KAddressInfo(KAddressInfo&) { }
+  KAddressInfo& operator=(KAddressInfo&) { return *this; }
+
+public:
+  ~KAddressInfo();
+
+  /**
+   * Returns the KAddressInfo's KSocketAddress.
+   * Only valid as long as the KAddressInfo exists.
+   */
+  inline KDE_DEPRECATED operator const ::KSocketAddress*() const 
+  { return addr; }
+
+  /**
+   * Returns the KAddressInfo's addrinfo.
+   */
+  inline KDE_DEPRECATED operator const addrinfo&() const
+  { return *ai; }
+
+  /**
+   * Returns a pointer to KAddressInfo's addrinfo.
+   * Only valid as long as the KAddressInfo exists.
+   */
+  inline KDE_DEPRECATED operator const addrinfo*() const
+  { return ai; }
+
+  /**
+   * Returns the KAddressInfo's KSocketAddress.
+   * Only valid as long as the KAddressInfo exists.
+   * @return the KAddressInfo's KSocketAddress.
+   */
+  inline KDE_DEPRECATED const ::KSocketAddress* address() const
+  { return addr; }
+
+  /**
+   * Returns the flags of the address info (see getaddrinfo(3)).
+   * @return the flags of the addres info.
+   */
+  int flags() const KDE_DEPRECATED;
+
+  /**
+   * Returns the family of the address info (see getaddrinfo(3)).
+   * @return the family of the addres info.
+   */
+  int family() const KDE_DEPRECATED;
+
+  /**
+   * Returns the socket type of the address info (see getaddrinfo(3)).
+   * @return the socket type of the addres info.
+   */
+  int socktype() const KDE_DEPRECATED;
+
+  /**
+   * Returns the protocol of the address info (see getaddrinfo(3)).
+   * @return the protocol of the addres info.
+   */
+  int protocol() const KDE_DEPRECATED;
+
+
+  /**
+   * Returns the official name of the host (see getaddrinfo(3)).
+   * Only valid as long as the KAddressInfo exists.
+   * @return the official name of the host
+   */
+  const char* canonname() const KDE_DEPRECATED;
+
+  /**
+   * Returns the length of the KSocketAddress.
+   * @return the KSocketAddress's length
+   */
+  inline int length() const
+  { if (addr) return addr->size(); return 0; }
+
+  friend class KExtendedSocket;
+};
+
+#endif //Q_OS_UNIX
+
+#endif // KEXTSOCK_H