qunixsocket.cpp

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#include "qunixsocket_p.h"

// #define QUNIXSOCKET_DEBUG 1

#include <QtCore/qsocketnotifier.h>
#include <QtCore/qqueue.h>
#include <QtCore/qdatetime.h>
#include "private/qcore_unix_p.h" // overrides QT_OPEN

#ifdef QUNIXSOCKET_DEBUG
#include <QtCore/qdebug.h>
#endif

extern "C" {
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/un.h>
};

#define UNIX_PATH_MAX 108 // From unix(7)

#ifdef QT_LINUXBASE
// LSB doesn't declare ucred
struct ucred
{
    pid_t pid;                    /* PID of sending process.  */
    uid_t uid;                    /* UID of sending process.  */
    gid_t gid;                    /* GID of sending process.  */
};

// LSB doesn't define the ones below
#ifndef SO_PASSCRED
#  define SO_PASSCRED   16
#endif
#ifndef SCM_CREDENTIALS
#  define SCM_CREDENTIALS 0x02
#endif
#ifndef MSG_DONTWAIT
#  define MSG_DONTWAIT 0x40
#endif
#ifndef MSG_NOSIGNAL
#  define MSG_NOSIGNAL 0x4000
#endif

#endif // QT_LINUXBASE

QT_BEGIN_NAMESPACE

// class QUnixSocketRights

struct QUnixSocketRightsPrivate : public QSharedData
{
    virtual ~QUnixSocketRightsPrivate() {
#ifdef QUNIXSOCKET_DEBUG
        int closerv =
#endif
            QT_CLOSE(fd);
#ifdef QUNIXSOCKET_DEBUG
        if(0 != closerv) {
            qDebug() << "QUnixSocketRightsPrivate: Unable to close managed"
                        " file descriptor (" << ::strerror(errno) << ')';
        }
#endif
    }

    int fd;
};

QUnixSocketRights::QUnixSocketRights(int fd)
{
    d = new QUnixSocketRightsPrivate();
    if(-1 == fd) {
        d->fd = -1;
    } else {
        d->fd = qt_safe_dup(fd);
#ifdef QUNIXSOCKET_DEBUG
        if(-1 == d->fd) {
            qDebug() << "QUnixSocketRights: Unable to duplicate fd "
                     << fd << " (" << ::strerror(errno) << ')';
        }
#endif
    }
}

QUnixSocketRights::QUnixSocketRights(int fd,int)
{
    Q_ASSERT(-1 != fd);
    d = new QUnixSocketRightsPrivate();
    d->fd = fd;
}

QUnixSocketRights::~QUnixSocketRights()
{
}

QUnixSocketRights &
QUnixSocketRights::operator=(const QUnixSocketRights & other)
{
    d = other.d;
    return *this;
}

QUnixSocketRights::QUnixSocketRights(const QUnixSocketRights & other)
: d(other.d)
{
}

bool QUnixSocketRights::isValid() const
{
    return d->fd != -1;
}

int QUnixSocketRights::dupFd() const
{
    if(-1 == d->fd) return -1;

    int rv = qt_safe_dup(d->fd);

#ifdef QUNIXSOCKET_DEBUG
    if(-1 == rv)
        qDebug() << "QUnixSocketRights: Unable to duplicate managed file "
                    "descriptor (" << ::strerror(errno) << ')';
#endif

    return rv;
}

int QUnixSocketRights::peekFd() const
{
    return d->fd;
}

// class QUnixSocketMessage
struct QUnixSocketMessagePrivate : public QSharedData
{
    QUnixSocketMessagePrivate()
    : state(Default), vec(0), iovecLen(0), dataSize(0) {}
    QUnixSocketMessagePrivate(const QByteArray & b)
    : bytes(b), state(Default), vec(0), iovecLen(0), dataSize(0) {}
    QUnixSocketMessagePrivate(const QByteArray & b,
                              const QList<QUnixSocketRights> & r)
    : bytes(b), rights(r), state(Default), vec(0), iovecLen(0), dataSize(0) {}

    int size() const { return vec ? dataSize : bytes.size(); }
    void removeBytes( unsigned int );

    QByteArray bytes;
    QList<QUnixSocketRights> rights;

    enum AncillaryDataState {
        Default = 0x00,
        Truncated = 0x01,
        Credential = 0x02
    };
    AncillaryDataState state;

    pid_t pid;
    gid_t gid;
    uid_t uid;

    ::iovec *vec;
    int iovecLen;  // number of vectors in array
    int dataSize;  // total size of vectors = payload
};

void QUnixSocketMessagePrivate::removeBytes( unsigned int bytesToDequeue )
{
    if ( vec )
    {
        ::iovec *vecPtr = vec;
        if ( bytesToDequeue > (unsigned int)dataSize ) bytesToDequeue = dataSize;
        while ( bytesToDequeue > 0 && iovecLen > 0 )
        {
            if ( vecPtr->iov_len > bytesToDequeue )
            {
                // dequeue the bytes by taking them off the front of the
                // current vector.  since we don't own the iovec, its okay
                // to "leak" this away by pointing past it
                char **base = reinterpret_cast<char**>(&(vecPtr->iov_base));
                *base += bytesToDequeue;
                vecPtr->iov_len -= bytesToDequeue;
                bytesToDequeue = 0;
            }
            else
            {
                // dequeue bytes by skipping a whole vector.  again, its ok
                // to lose the pointers to this data
                bytesToDequeue -= vecPtr->iov_len;
                iovecLen--;
                vecPtr++;
            }
        }
        dataSize -= bytesToDequeue;
        if ( iovecLen == 0 ) vec = 0;
    }
    else
    {
        bytes.remove(0, bytesToDequeue );
    }
}


QUnixSocketMessage::QUnixSocketMessage()
: d(new QUnixSocketMessagePrivate())
{
}

QUnixSocketMessage::QUnixSocketMessage(const QByteArray & bytes)
: d(new QUnixSocketMessagePrivate(bytes))
{
}

QUnixSocketMessage::QUnixSocketMessage(const QByteArray & bytes,
                                       const QList<QUnixSocketRights> & rights)
: d(new QUnixSocketMessagePrivate(bytes, rights))
{
}

QUnixSocketMessage::QUnixSocketMessage(const QUnixSocketMessage & other)
: d(other.d)
{
}

QUnixSocketMessage::QUnixSocketMessage(const ::iovec* data, int vecLen )
: d(new QUnixSocketMessagePrivate())
{
    for ( int v = 0; v < vecLen; v++ )
        d->dataSize += data[v].iov_len;
    d->vec = const_cast<iovec*>(data);
    d->iovecLen = vecLen;
}

QUnixSocketMessage & QUnixSocketMessage::operator=(const QUnixSocketMessage & other)
{
    d = other.d;
    return *this;
}

QUnixSocketMessage::~QUnixSocketMessage()
{
}

void QUnixSocketMessage::setBytes(const QByteArray & bytes)
{
    d.detach();
    d->bytes = bytes;
}

void QUnixSocketMessage::setRights(const QList<QUnixSocketRights> & rights)
{
    d.detach();
    d->rights = rights;
}

const QList<QUnixSocketRights> & QUnixSocketMessage::rights() const
{
    return d->rights;
}

bool QUnixSocketMessage::rightsWereTruncated() const
{
    return d->state & QUnixSocketMessagePrivate::Truncated;
}

const QByteArray & QUnixSocketMessage::bytes() const
{
    return d->bytes;
}

pid_t QUnixSocketMessage::processId() const
{
    if(QUnixSocketMessagePrivate::Credential & d->state)
        return d->pid;
    else
        return ::getpid();
}

uid_t QUnixSocketMessage::userId() const
{
    if(QUnixSocketMessagePrivate::Credential & d->state)
        return d->uid;
    else
        return ::geteuid();
}

gid_t QUnixSocketMessage::groupId() const
{
    if(QUnixSocketMessagePrivate::Credential & d->state)
        return d->gid;
    else
        return ::getegid();
}

void QUnixSocketMessage::setProcessId(pid_t pid)
{
    if(!(d->state & QUnixSocketMessagePrivate::Credential)) {
        d->state = (QUnixSocketMessagePrivate::AncillaryDataState)( d->state | QUnixSocketMessagePrivate::Credential );
        d->uid = ::geteuid();
        d->gid = ::getegid();
    }
    d->pid = pid;
}

void QUnixSocketMessage::setUserId(uid_t uid)
{
    if(!(d->state & QUnixSocketMessagePrivate::Credential)) {
        d->state = (QUnixSocketMessagePrivate::AncillaryDataState)( d->state | QUnixSocketMessagePrivate::Credential );
        d->pid = ::getpid();
        d->gid = ::getegid();
    }
    d->uid = uid;
}

void QUnixSocketMessage::setGroupId(gid_t gid)
{
    if(!(d->state & QUnixSocketMessagePrivate::Credential)) {
        d->state = (QUnixSocketMessagePrivate::AncillaryDataState)( d->state | QUnixSocketMessagePrivate::Credential );
        d->pid = ::getpid();
        d->uid = ::geteuid();
    }
    d->gid = gid;
}

bool QUnixSocketMessage::isValid() const
{
    return d->rights.isEmpty() || !d->bytes.isEmpty();
}

// class QUnixSocket
#define QUNIXSOCKET_DEFAULT_READBUFFER 1024
#define QUNIXSOCKET_DEFAULT_ANCILLARYBUFFER 0

/*
  \fn QUnixSocket::bytesWritten(qint64 bytes)

  This signal is emitted every time a payload of data has been written to the
  connection.  The \a bytes argument is set to the number of bytes that were
  written in this payload.

  \sa QUnixSocket::readyRead()
*/

/*
  \fn QUnixSocket::readyRead()

  This signal is emitted once every time new data is available for reading from
  the connection. It will only be emitted again once new data is available.

  \sa QUnixSocket::bytesWritten()
*/

class QUnixSocketPrivate : public QObject {
Q_OBJECT
public:
    QUnixSocketPrivate(QUnixSocket * _me)
    : me(_me), fd(-1), readNotifier(0), writeNotifier(0),
      state(QUnixSocket::UnconnectedState), error(QUnixSocket::NoError),
      writeQueueBytes(0), messageValid(false), dataBuffer(0),
      dataBufferLength(0), dataBufferCapacity(0), ancillaryBuffer(0),
      ancillaryBufferCount(0), closingTimer(0) {
          QObject::connect(this, SIGNAL(readyRead()), me, SIGNAL(readyRead()));
          QObject::connect(this, SIGNAL(bytesWritten(qint64)),
                           me, SIGNAL(bytesWritten(qint64)));
      }
    ~QUnixSocketPrivate()
    {
        if(dataBuffer)
            delete [] dataBuffer;
        if(ancillaryBuffer)
            delete [] ancillaryBuffer;
    }

    enum { CausedAbort = 0x70000000 };

    QUnixSocket * me;

    int fd;

    QSocketNotifier * readNotifier;
    QSocketNotifier * writeNotifier;

    QUnixSocket::SocketState state;
    QUnixSocket::SocketError error;

    QQueue<QUnixSocketMessage> writeQueue;
    unsigned int writeQueueBytes;

    bool messageValid;
    ::msghdr message;
    inline void flushAncillary()
    {
        if(!messageValid) return;
        ::cmsghdr * h = (::cmsghdr *)CMSG_FIRSTHDR(&(message));
        while(h) {

            if(SCM_RIGHTS == h->cmsg_type) {
                int * fds = (int *)CMSG_DATA(h);
                int numFds = (h->cmsg_len - CMSG_LEN(0)) / sizeof(int);

                for(int ii = 0; ii < numFds; ++ii)
                    QT_CLOSE(fds[ii]);
            }

            h = (::cmsghdr *)CMSG_NXTHDR(&(message), h);
        }

        messageValid = false;
    }


    char * dataBuffer;
    unsigned int dataBufferLength;
    unsigned int dataBufferCapacity;

    char * ancillaryBuffer;
    inline unsigned int ancillaryBufferCapacity()
    {
        return CMSG_SPACE(sizeof(::ucred)) + CMSG_SPACE(sizeof(int) * ancillaryBufferCount);
    }
    unsigned int ancillaryBufferCount;

    QByteArray address;

    int closingTimer;

    virtual void timerEvent(QTimerEvent *)
    {
        me->abort();
        killTimer(closingTimer);
        closingTimer = 0;
    }
signals:
    void readyRead();
    void bytesWritten(qint64);

public slots:
    void readActivated();
    qint64 writeActivated();
};

QUnixSocket::QUnixSocket(QObject * parent)
: QIODevice(parent), d(new QUnixSocketPrivate(this))
{
    setOpenMode(QIODevice::NotOpen);
    setReadBufferSize(QUNIXSOCKET_DEFAULT_READBUFFER);
    setRightsBufferSize(QUNIXSOCKET_DEFAULT_ANCILLARYBUFFER);
}

QUnixSocket::QUnixSocket(qint64 readBufferSize, qint64 rightsBufferSize,
                         QObject * parent)
: QIODevice(parent), d(new QUnixSocketPrivate(this))
{
    Q_ASSERT(readBufferSize > 0 && rightsBufferSize >= 0);

    setOpenMode(QIODevice::NotOpen);
    setReadBufferSize(readBufferSize);
    setRightsBufferSize(rightsBufferSize);
}

QUnixSocket::~QUnixSocket()
{
    abort();
    delete d;
}

bool QUnixSocket::connect(const QByteArray & path)
{
    int _true;
    int crv;
#ifdef QUNIXSOCKET_DEBUG
    qDebug() << "QUnixSocket: Connect requested to '"
             << path << '\'';
#endif

    abort(); // Reset any existing connection

    if(UnconnectedState != d->state) // abort() caused a signal and someone messed
                                 // with us.  We'll assume they know what
                                 // they're doing and bail.  Alternative is to
                                 // have a special "Connecting" state
        return false;


    if(path.isEmpty() || path.size() > UNIX_PATH_MAX) {
        d->error = InvalidPath;
        return false;
    }

    // Create the socket
    d->fd = ::socket(PF_UNIX, SOCK_STREAM, 0);
    if(-1 == d->fd) {
#ifdef QUNIXSOCKET_DEBUG
        qDebug() << "QUnixSocket: Unable to create socket ("
                 << strerror(errno) << ')';
#endif
        d->error = ResourceError;
        goto connect_error;
    }

    // Set socket options
    _true = 1;
    crv = ::setsockopt(d->fd, SOL_SOCKET, SO_PASSCRED, (void *)&_true,
                       sizeof(int));
    if(-1 == crv) {
#ifdef QUNIXSOCKET_DEBUG
        qDebug() << "QUnixSocket: Unable to configure socket ("
                 << ::strerror(errno) << ')';
#endif
        d->error = ResourceError;

        goto connect_error;
    }

    // Construct our unix address
    struct ::sockaddr_un addr;
    addr.sun_family = AF_UNIX;
    ::memcpy(addr.sun_path, path.data(), path.size());
    if(path.size() < UNIX_PATH_MAX)
        addr.sun_path[path.size()] = '\0';

    // Attempt the connect
    crv = ::connect(d->fd, (sockaddr *)&addr, sizeof(sockaddr_un));
    if(-1 == crv) {
#ifdef QUNIXSOCKET_DEBUG
        qDebug() << "QUnixSocket: Unable to connect ("
                 << ::strerror(errno) << ')';
#endif
        if(ECONNREFUSED == errno)
            d->error = ConnectionRefused;
        else if(ENOENT == errno)
            d->error = NonexistentPath;
        else
            d->error = UnknownError;

        goto connect_error;
    }

    // We're connected!
    d->address = path;
    d->state = ConnectedState;
    d->readNotifier = new QSocketNotifier(d->fd, QSocketNotifier::Read, d);
    d->writeNotifier = new QSocketNotifier(d->fd, QSocketNotifier::Write, d);
    QObject::connect(d->readNotifier, SIGNAL(activated(int)),
                     d, SLOT(readActivated()));
    QObject::connect(d->writeNotifier, SIGNAL(activated(int)),
                     d, SLOT(writeActivated()));
    d->readNotifier->setEnabled(true);
    d->writeNotifier->setEnabled(false);
    setOpenMode(QIODevice::ReadWrite);
    emit stateChanged(ConnectedState);

#ifdef QUNIXSOCKET_DEBUG
    qDebug() << "QUnixSocket: Connected to " << path;
#endif
    return true;

connect_error: // Cleanup failed connection
    if(-1 != d->fd) {
#ifdef QUNIXSOCKET_DEBUG
        int closerv =
#endif
            QT_CLOSE(d->fd);
#ifdef QUNIXSOCKET_DEBUG
        if(0 != closerv) {
            qDebug() << "QUnixSocket: Unable to close file descriptor after "
                        "failed connect (" << ::strerror(errno) << ')';
        }
#endif
    }
    d->fd = -1;
    return false;
}

bool QUnixSocket::setSocketDescriptor(int socketDescriptor)
{
    abort();

    if(UnconnectedState != state()) // See QUnixSocket::connect()
        return false;

    // Attempt to set the socket options
    if(-1 == socketDescriptor) {
#ifdef QUNIXSOCKET_DEBUG
        qDebug() << "QUnixSocket: User provided socket is invalid";
#endif
        d->error = ResourceError;
        return false;
    }

    // Set socket options
    int _true = 1;
    int crv = ::setsockopt(socketDescriptor, SOL_SOCKET,
                           SO_PASSCRED, (void *)&_true, sizeof(int));
    if(-1 == crv) {
#ifdef QUNIXSOCKET_DEBUG
        qDebug() << "QUnixSocket: Unable to configure client provided socket ("
                 << ::strerror(errno) << ')';
#endif
        d->error = ResourceError;

        return false;
    }

    d->fd = socketDescriptor;
    d->state = ConnectedState;
    d->address = QByteArray();
    setOpenMode(QIODevice::ReadWrite);
    d->readNotifier = new QSocketNotifier(d->fd, QSocketNotifier::Read, d);
    d->writeNotifier = new QSocketNotifier(d->fd, QSocketNotifier::Write, d);
    QObject::connect(d->readNotifier, SIGNAL(activated(int)),
                     d, SLOT(readActivated()));
    QObject::connect(d->writeNotifier, SIGNAL(activated(int)),
                     d, SLOT(writeActivated()));
    d->readNotifier->setEnabled(true);
    d->writeNotifier->setEnabled(false);
    emit stateChanged(d->state);

    return true;
}

int QUnixSocket::socketDescriptor() const
{
    return d->fd;
}

void QUnixSocket::abort()
{
    setOpenMode(QIODevice::NotOpen);

    // We want to be able to use QUnixSocket::abort() to cleanup our state but
    // also preserve the error message that caused the abort.  It is not
    // possible to reorder code to do this:
    //        abort();
    //        d->error = SomeError
    // as QUnixSocket::abort() might emit a signal and we need the error to be
    // set within that signal.  So, if we want an error message to be preserved
    // across a *single* call to abort(), we set the
    // QUnixSocketPrivate::CausedAbort flag in the error.
    if(d->error & QUnixSocketPrivate::CausedAbort)
        d->error = (QUnixSocket::SocketError)(d->error &
                                              ~QUnixSocketPrivate::CausedAbort);
    else
        d->error = NoError;

    if( UnconnectedState == d->state) return;

#ifdef QUNIXSOCKET_DEBUG
    int closerv =
#endif
        ::close(d->fd);
#ifdef QUNIXSOCKET_DEBUG
    if(0 != closerv) {
        qDebug() << "QUnixSocket: Unable to close socket during abort ("
                 << strerror(errno) << ')';
    }
#endif

    // Reset variables
    d->fd = -1;
    d->state = UnconnectedState;
    d->dataBufferLength = 0;
    d->flushAncillary();
    d->address = QByteArray();
    if(d->readNotifier) {
        d->readNotifier->setEnabled(false);
        d->readNotifier->deleteLater();
    }
    if(d->writeNotifier) {
        d->writeNotifier->setEnabled(false);
        d->writeNotifier->deleteLater();
    }
    d->readNotifier = 0;
    d->writeNotifier = 0;
    d->writeQueue.clear();
    d->writeQueueBytes = 0;
    if(d->closingTimer) {
        d->killTimer(d->closingTimer);
    }
    d->closingTimer = 0;
    emit stateChanged(d->state);
}

void QUnixSocket::close()
{
    if(ConnectedState != state()) return;

    d->state = ClosingState;
    if(d->writeQueue.isEmpty()) {
        d->closingTimer = d->startTimer(0); // Start a timer to "fake"
                                            // completing writes
    }
    emit stateChanged(d->state);
}

// Note! docs partially copied from QAbstractSocket::flush()
bool QUnixSocket::flush()
{
    // This needs to have the same semantics as QAbstractSocket, if it is to
    // be used interchangeably with that class.
    if (d->writeQueue.isEmpty())
        return false;

    d->writeActivated();
    return true;
}

QUnixSocket::SocketError QUnixSocket::error() const
{
    return (QUnixSocket::SocketError)
        (d->error & ~QUnixSocketPrivate::CausedAbort);
}

QUnixSocket::SocketState QUnixSocket::state() const
{
    return d->state;
}

QByteArray QUnixSocket::address() const
{
    return d->address;
}

qint64 QUnixSocket::bytesAvailable() const
{
    return QIODevice::bytesAvailable() + d->dataBufferLength;
}

qint64 QUnixSocket::bytesToWrite() const
{
    return d->writeQueueBytes;
}

qint64 QUnixSocket::readBufferSize() const
{
    return d->dataBufferCapacity;
}

void QUnixSocket::setReadBufferSize(qint64 size)
{
    Q_ASSERT(size > 0);
    if(size == d->dataBufferCapacity || d->dataBufferLength) return;
    if(d->dataBuffer) delete [] d->dataBuffer;
    d->dataBuffer = new char[size];
    d->dataBufferCapacity = size;
}

qint64 QUnixSocket::rightsBufferSize() const
{
    return d->ancillaryBufferCount;
}

void QUnixSocket::setRightsBufferSize(qint64 size)
{
    Q_ASSERT(size >= 0);

    if((size == d->ancillaryBufferCount || d->dataBufferLength) &&
            d->ancillaryBuffer)
        return;

    qint64 byteSize = CMSG_SPACE(sizeof(::ucred)) +
                      CMSG_SPACE(size * sizeof(int));

    if(d->ancillaryBuffer) delete [] d->ancillaryBuffer;
    d->ancillaryBuffer = new char[byteSize];
    d->ancillaryBufferCount = size;
}

qint64 QUnixSocket::write(const QUnixSocketMessage & socketdata)
{
    if(ConnectedState != state() || !socketdata.isValid()) return -1;
    if(socketdata.d->size() == 0) return 0;

    d->writeQueue.enqueue(socketdata);
    d->writeQueueBytes += socketdata.d->size();
    d->writeNotifier->setEnabled(true);

    return socketdata.d->size();
}

QUnixSocketMessage QUnixSocket::read()
{
    QUnixSocketMessage data;
    if(!d->dataBufferLength)
        return data;

    data.d->state = QUnixSocketMessagePrivate::Credential;

    // Bytes are easy
    data.setBytes(QByteArray(d->dataBuffer, d->dataBufferLength));

    // Extract ancillary data
    QList<QUnixSocketRights> a;

    ::cmsghdr * h = (::cmsghdr *)CMSG_FIRSTHDR(&(d->message));
    while(h) {

        if(SCM_CREDENTIALS == h->cmsg_type) {
            ::ucred * cred = (::ucred *)CMSG_DATA(h);
#ifdef QUNIXSOCKET_DEBUG
            qDebug( "Credentials recd: pid %lu - gid %lu - uid %lu",
                    cred->pid, cred->gid, cred->uid );
#endif
            data.d->pid = cred->pid;
            data.d->gid = cred->gid;
            data.d->uid = cred->uid;

        } else if(SCM_RIGHTS == h->cmsg_type) {

            int * fds = (int *)CMSG_DATA(h);
            int numFds = (h->cmsg_len - CMSG_LEN(0)) / sizeof(int);

            for(int ii = 0; ii < numFds; ++ii) {
                QUnixSocketRights qusr(fds[ii], 0);
                a.append(qusr);
            }

        } else {

#ifdef QUNIXSOCKET_DEBUG
            qFatal("QUnixSocket: Unknown ancillary data type (%d) received.",
                   h->cmsg_type);
#endif

        }

        h = (::cmsghdr *)CMSG_NXTHDR(&(d->message), h);
    }

    if(d->message.msg_flags & MSG_CTRUNC) {
        data.d->state = (QUnixSocketMessagePrivate::AncillaryDataState)(QUnixSocketMessagePrivate::Truncated |
                               QUnixSocketMessagePrivate::Credential );
    }

    if(!a.isEmpty())
        data.d->rights = a;

    d->dataBufferLength = 0;
    d->messageValid = false;
    d->readNotifier->setEnabled(true);

    return data;
}

bool QUnixSocket::isSequential() const
{
    return true;
}

bool QUnixSocket::waitForReadyRead(int msecs)
{
    if(UnconnectedState == d->state)
        return false;

    if(d->messageValid) {
        return true;
    }

    Q_ASSERT(-1 != d->fd);

    int     timeout = msecs;
    struct  timeval tv;
    struct  timeval *ptrTv = 0;
    QTime   stopWatch;

    stopWatch.start();

    do
    {
        fd_set readset;

        FD_ZERO(&readset);
        FD_SET(d->fd, &readset);

        if(-1 != msecs) {
            tv.tv_sec = timeout / 1000;
            tv.tv_usec = (timeout % 1000) * 1000;
            ptrTv = &tv;
        }

        int rv = ::select(d->fd + 1, &readset, 0, 0, ptrTv);
        switch(rv) {
            case 0:
                // timeout
                return false;
            case 1:
                // ok
                d->readActivated();
                return true;
            default:
                if (errno != EINTR)
                    abort();    // error
                break;
        }

        timeout = msecs - stopWatch.elapsed();
    }
    while (timeout > 0);

    return false;
}

bool QUnixSocket::waitForBytesWritten(int msecs)
{
    if(UnconnectedState == d->state)
        return false;

    Q_ASSERT(-1 != d->fd);

    if ( d->writeQueue.isEmpty() )
        return true;

    QTime stopWatch;
    stopWatch.start();

    while ( true )
    {
        fd_set fdwrite;
        FD_ZERO(&fdwrite);
        FD_SET(d->fd, &fdwrite);
        int timeout = msecs < 0 ? 0 : msecs - stopWatch.elapsed();
        struct timeval tv;
        struct timeval *ptrTv = 0;
        if ( -1 != msecs )
        {
            tv.tv_sec = timeout / 1000;
            tv.tv_usec = (timeout % 1000) * 1000;
            ptrTv = &tv;
        }

        int rv = ::select(d->fd + 1, 0, &fdwrite, 0, ptrTv);
        switch ( rv )
        {
            case 0:
                // timeout
                return false;
            case 1:
            {
                // ok to write
                qint64 bytesWritten = d->writeActivated();
                if (bytesWritten == 0) {
                    // We need to retry
                    int delay = 1;
                    do {
                        if (-1 != msecs) {
                            timeout = msecs - stopWatch.elapsed();
                            if (timeout <= 0) {
                                // We have exceeded our allotted time
                                return false;
                            } else {
                                if (delay > timeout)
                                    delay = timeout;
                            }
                        }

                        // Pause before we make another attempt to send
                        ::usleep(delay * 1000);
                        if (delay < 1024)
                            delay *= 2;

                        bytesWritten = d->writeActivated();
                    } while (bytesWritten == 0);
                }
                return (bytesWritten != -1);
            }
            default:
                // error - or an uncaught signal!!!!!!!!!
                if ( rv == EINTR )
                    continue;
                abort();
                return false;
        }
    }
    return false; // fix warnings
}

bool QUnixSocket::canReadLine() const
{
    for(unsigned int ii = 0; ii < d->dataBufferLength; ++ii)
        if(d->dataBuffer[ii] == '\n') return true;
    return false;
}

qint64 QUnixSocket::readData(char * data, qint64 maxSize)
{
    Q_ASSERT(data);
    if(0 >= maxSize) return 0;
    if(!d->dataBufferLength) return 0;

    // Read data
    unsigned int size = d->dataBufferLength>maxSize?maxSize:d->dataBufferLength;
    memcpy(data, d->dataBuffer, size);
    if(size == d->dataBufferLength) {
        d->dataBufferLength = 0;
    } else {
        memmove(d->dataBuffer, d->dataBuffer + size, d->dataBufferLength - size);
        d->dataBufferLength -= size;
    }


    // Flush ancillary
    d->flushAncillary();

    if(0 == d->dataBufferLength)
        d->readNotifier->setEnabled(true);

    return size;
}

qint64 QUnixSocket::writeData (const char * data, qint64 maxSize)
{
    return write(QUnixSocketMessage(QByteArray(data, maxSize)));
}

qint64 QUnixSocketPrivate::writeActivated()
{
    writeNotifier->setEnabled(false);

    QUnixSocketMessage & m = writeQueue.head();
    const QList<QUnixSocketRights> & a = m.rights();

    //
    // Construct the message
    //
    ::iovec vec;
    if ( !m.d->vec ) // message does not already have an iovec
    {
        vec.iov_base = (void *)m.bytes().constData();
        vec.iov_len = m.bytes().size();
    }

    // Allocate the control buffer
    ::msghdr sendmessage;
    ::bzero(&sendmessage, sizeof(::msghdr));
    if ( m.d->vec )
    {
        sendmessage.msg_iov = m.d->vec;
        sendmessage.msg_iovlen = m.d->iovecLen;
    }
    else
    {
        sendmessage.msg_iov = &vec;
        sendmessage.msg_iovlen = 1;
    }
    unsigned int required = CMSG_SPACE(sizeof(::ucred)) +
                            a.size() * CMSG_SPACE(sizeof(int));
    sendmessage.msg_control = new char[required];
    ::bzero(sendmessage.msg_control, required);
    sendmessage.msg_controllen = required;

    // Create ancillary buffer
    ::cmsghdr * h = CMSG_FIRSTHDR(&sendmessage);

    if(m.d->state & QUnixSocketMessagePrivate::Credential) {
        h->cmsg_len = CMSG_LEN(sizeof(::ucred));
        h->cmsg_level = SOL_SOCKET;
        h->cmsg_type = SCM_CREDENTIALS;
        ((::ucred *)CMSG_DATA(h))->pid = m.d->pid;
        ((::ucred *)CMSG_DATA(h))->gid = m.d->gid;
        ((::ucred *)CMSG_DATA(h))->uid = m.d->uid;
        h = CMSG_NXTHDR(&sendmessage, h);
    } else {
        sendmessage.msg_controllen -= CMSG_SPACE(sizeof(::ucred));
    }

    for(int ii = 0; ii < a.count(); ++ii) {
        const QUnixSocketRights & r = a.at(ii);

        if(r.isValid()) {
            h->cmsg_len = CMSG_LEN(sizeof(int));
            h->cmsg_level = SOL_SOCKET;
            h->cmsg_type = SCM_RIGHTS;
            *((int *)CMSG_DATA(h)) = r.peekFd();
            h = CMSG_NXTHDR(&sendmessage, h);
        } else {
            sendmessage.msg_controllen -= CMSG_SPACE(sizeof(int));
        }
    }

#ifdef QUNIXSOCKET_DEBUG
    qDebug() << "QUnixSocket: Transmitting message (length" << m.d->size() << ')';
#endif
    ::ssize_t s = ::sendmsg(fd, &sendmessage, MSG_DONTWAIT | MSG_NOSIGNAL);
#ifdef QUNIXSOCKET_DEBUG
    qDebug() << "QUnixSocket: Transmitted message (" << s << ')';
#endif

    if(-1 == s) {
        if(EAGAIN == errno || EWOULDBLOCK == errno || EINTR == errno) {
            writeNotifier->setEnabled(true);
        } else if(EPIPE == errno) {
#ifdef QUNIXSOCKET_DEBUG
            qDebug() << "QUnixSocket: Remote side disconnected during transmit "
                        "(" << ::strerror(errno) << ')';
#endif
            me->abort();
        } else {
#ifdef QUNIXSOCKET_DEBUG
            qDebug() << "QUnixSocket: Unable to transmit data ("
                     << ::strerror(errno) << ')';
#endif
            error = (QUnixSocket::SocketError)(QUnixSocket::WriteFailure |
                    CausedAbort);
            me->abort();
        }
    } else if(s != m.d->size()) {

        // A partial transmission
        writeNotifier->setEnabled(true);
        delete [] (char *)sendmessage.msg_control;
        m.d->rights = QList<QUnixSocketRights>();
        m.d->removeBytes( s );
        writeQueueBytes -= s;
        emit bytesWritten(s);
        return s;

    } else {

        // Success!
        writeQueue.dequeue();
        Q_ASSERT(writeQueueBytes >= (unsigned)s);
        writeQueueBytes -= s;
        emit bytesWritten(s);

    }

    delete [] (char *)sendmessage.msg_control;
    if(-1 != s && !writeQueue.isEmpty())
        return writeActivated();
    else if(QUnixSocket::ClosingState == me->state() && writeQueue.isEmpty())
        me->abort();

    if((-1 == s) && (EAGAIN == errno || EWOULDBLOCK == errno || EINTR == errno))
        // Return zero bytes written to indicate retry may be required
        return 0;
    else
        return s;
}

void QUnixSocketPrivate::readActivated()
{
#ifdef QUNIXSOCKET_DEBUG
    qDebug() << "QUnixSocket: readActivated";
#endif
    readNotifier->setEnabled(false);

    ::iovec vec;
    vec.iov_base = dataBuffer;
    vec.iov_len = dataBufferCapacity;

    bzero(&message, sizeof(::msghdr));
    message.msg_iov = &vec;
    message.msg_iovlen = 1;
    message.msg_controllen = ancillaryBufferCapacity();
    message.msg_control = ancillaryBuffer;

    int flags = 0;
#ifdef MSG_CMSG_CLOEXEC
    flags = MSG_CMSG_CLOEXEC;
#endif

    int recvrv = ::recvmsg(fd, &message, flags);
#ifdef QUNIXSOCKET_DEBUG
    qDebug() << "QUnixSocket: Received message (" << recvrv << ')';
#endif
    if(-1 == recvrv) {
#ifdef QUNIXSOCKET_DEBUG
        qDebug() << "QUnixSocket: Unable to receive data ("
                 << ::strerror(errno) << ')';
#endif
        error = (QUnixSocket::SocketError)(QUnixSocket::ReadFailure |
                                           CausedAbort);
        me->abort();
    } else if(0 == recvrv) {
        me->abort();
    } else {
        Q_ASSERT(recvrv);
        Q_ASSERT((unsigned)recvrv <= dataBufferCapacity);
        dataBufferLength = recvrv;
        messageValid = true;

#ifdef QUNIXSOCKET_DEBUG
        qDebug() << "QUnixSocket: readyRead() " << dataBufferLength;
#endif
        emit readyRead();
    }
}

QT_END_NAMESPACE

#include "qunixsocket.moc"