kdelibs/kinit/kinit.cpp

/*
 * This file is part of the KDE libraries
 * Copyright (c) 1999-2000 Waldo Bastian <bastian@kde.org>
 *           (c) 1999 Mario Weilguni <mweilguni@sime.com>
 *           (c) 2001 Lubos Lunak <l.lunak@kde.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License version 2 as published by the Free Software Foundation.
 *
 * 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.
 */

#define QT_NO_CAST_FROM_ASCII

#include <config.h>
#include <config-kdeinit.h>

#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <sys/select.h> // Needed on some systems.
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <locale.h>

#include <qplatformdefs.h>
#include <QtCore/QLibrary>
#include <QtCore/QString>
#include <QtCore/QFile>
#include <QtCore/QRegExp>
#include <kcomponentdata.h>
#include <kstandarddirs.h>
#include <kglobal.h>
#include <kconfig.h>
#include <kapplication.h>
#include <klocale.h>
#include <kdebug.h>
#include <kde_file.h>
#include <ksavefile.h>
#include <kpluginloader.h>
#include <kdeversion.h>
#include "klauncher_cmds.h"
#include "proctitle.h"

#ifdef Q_OS_LINUX
#include <sys/prctl.h>
#ifndef PR_SET_NAME
#define PR_SET_NAME 15
#endif
#endif

#ifdef Q_WS_X11
#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <fixx11h.h>
#include <kstartupinfo.h>
#endif

// #define SKIP_PROCTITLE 1

extern char **environ;

#ifdef Q_WS_X11
static int X11fd = -1;
static Display *X11display = 0;
static int X11_startup_notify_fd = -1;
static Display *X11_startup_notify_display = 0;
#endif
static KComponentData *s_instance = 0;
#define MAX_SOCK_FILE 255
static char sock_file[MAX_SOCK_FILE];

#ifdef Q_WS_X11
#define DISPLAY "DISPLAY"
#elif defined(Q_WS_QWS)
#define DISPLAY "QWS_DISPLAY"
#else
#error Use QT/X11 or QT/Embedded
#endif

/* Group data */
static struct {
  int maxname;
  int fd[2];
  int launcher[2]; /* socket pair for launcher communication */
  int deadpipe[2]; /* pipe used to detect dead children */
  int initpipe[2];
  int wrapper; /* socket for wrapper communication */
  int accepted_fd; /* socket accepted and that must be closed in the child process */
  char result;
  int exit_status;
  pid_t fork;
  pid_t launcher_pid;
  int n;
  char **argv;
  int (*func)(int, char *[]);
  int (*launcher_func)(int);
  bool debug_wait;
  QByteArray errorMsg;
  bool launcher_ok;
  bool suicide;
} d;

struct child
{
  pid_t pid;
  int sock; /* fd to write message when child is dead*/
  struct child *next;
};

static struct child *children;

#ifdef Q_WS_X11
extern "C" {
int kdeinit_xio_errhandler( Display * );
int kdeinit_x_errhandler( Display *, XErrorEvent *err );
}
#endif

/*
 * Clean up the file descriptor table by closing all file descriptors
 * that are still open.
 *
 * This function is called very early in the main() function, so that
 * we don't leak anything that was leaked to us.
 */
static void cleanup_fds()
{
    int maxfd = FD_SETSIZE;
    struct rlimit rl;
    if (getrlimit(RLIMIT_NOFILE, &rl) == 0)
        maxfd = rl.rlim_max;
    for (int fd = 3; fd < maxfd; ++fd)
    {
        close(fd);
    }
}

/*
 * Close fd's which are only useful for the parent process.
 * Restore default signal handlers.
 */
static void close_fds()
{
   while (struct child *child = children) {
      close(child->sock);
      children = child->next;
      free(child);
   }

   if (d.deadpipe[0] != -1)
   {
      close(d.deadpipe[0]);
      d.deadpipe[0] = -1;
   }

   if (d.deadpipe[1] != -1)
   {
      close(d.deadpipe[1]);
      d.deadpipe[1] = -1;
   }

   if (d.initpipe[0] != -1)
   {
      close(d.initpipe[0]);
      d.initpipe[0] = -1;
   }

   if (d.initpipe[1] != -1)
   {
      close(d.initpipe[1]);
      d.initpipe[1] = -1;
   }

   if (d.launcher[0] != -1)
   {
      close(d.launcher[0]);
      d.launcher[0] = -1;
   }
   if (d.wrapper != -1)
   {
      close(d.wrapper);
      d.wrapper = -1;
   }
   if (d.accepted_fd != -1)
   {
      close(d.accepted_fd);
      d.accepted_fd = -1;
   }
#ifdef Q_WS_X11
   if (X11fd >= 0)
   {
      close(X11fd);
      X11fd = -1;
   }
   if (X11_startup_notify_fd >= 0 && X11_startup_notify_fd != X11fd )
   {
      close(X11_startup_notify_fd);
      X11_startup_notify_fd = -1;
   }
#endif

   KDE_signal(SIGCHLD, SIG_DFL);
   KDE_signal(SIGPIPE, SIG_DFL);
}

/* Notify wrapper program that the child it started has finished. */
static void child_died(pid_t exit_pid, int exit_status)
{
   struct child *child, **childptr = &children;

   while ((child = *childptr))
   {
      if (child->pid == exit_pid)
      {
         /* Send a message with the return value of the child on the control socket */
         klauncher_header request_header;
         long request_data[2];
         request_header.cmd = LAUNCHER_CHILD_DIED;
         request_header.arg_length = sizeof(long) * 2;
         request_data[0] = exit_pid;
         request_data[1] = exit_status;
         write(child->sock, &request_header, sizeof(request_header));
         write(child->sock, request_data, request_header.arg_length);
         close(child->sock);

         *childptr = child->next;
         free(child);
         return;
      }

      childptr = &child->next;
   }
}


static void exitWithErrorMsg(const QString &errorMsg)
{
   fprintf( stderr, "%s\n", errorMsg.toLocal8Bit().data() );
   QByteArray utf8ErrorMsg = errorMsg.toUtf8();
   d.result = 3; // Error with msg
   write(d.fd[1], &d.result, 1);
   int l = utf8ErrorMsg.length();
   write(d.fd[1], &l, sizeof(int));
   write(d.fd[1], utf8ErrorMsg.data(), l);
   close(d.fd[1]);
   exit(255);
}

static void setup_tty( const char* tty )
{
    if( tty == NULL || *tty == '\0' )
        return;
    int fd = KDE_open( tty, O_WRONLY );
    if( fd < 0 )
    {
        perror( "kdeinit4: could not open() tty" );
        return;
    }
    if( dup2( fd, STDOUT_FILENO ) < 0 )
    {
        perror( "kdeinit4: could not dup2() stdout tty" );
    }
    if( dup2( fd, STDERR_FILENO ) < 0 )
    {
        perror( "kdeinit4: could not dup2() stderr tty" );
    }
    close( fd );
}

// from kdecore/netwm.cpp
static int get_current_desktop( Display* disp )
{
    int desktop = 0; // no desktop by default
#ifdef Q_WS_X11 // Only X11 supports multiple desktops
    Atom net_current_desktop = XInternAtom( disp, "_NET_CURRENT_DESKTOP", False );
    Atom type_ret;
    int format_ret;
    unsigned char *data_ret;
    unsigned long nitems_ret, unused;
    if( XGetWindowProperty( disp, DefaultRootWindow( disp ), net_current_desktop,
        0l, 1l, False, XA_CARDINAL, &type_ret, &format_ret, &nitems_ret, &unused, &data_ret )
	    == Success)
    {
	if (type_ret == XA_CARDINAL && format_ret == 32 && nitems_ret == 1)
	    desktop = *((long *) data_ret) + 1;
        if (data_ret)
            XFree ((char*) data_ret);
    }
#endif
    return desktop;
}

// var has to be e.g. "DISPLAY=", i.e. with =
const char* get_env_var( const char* var, int envc, const char* envs )
{
    if( envc > 0 )
    { // get the var from envs
        const char* env_l = envs;
        int ln = strlen( var );
        for (int i = 0;  i < envc; i++)
        {
            if( strncmp( env_l, var, ln ) == 0 )
                return env_l + ln;
            while(*env_l != 0) env_l++;
                env_l++;
        }
    }
    return NULL;
}

#ifdef Q_WS_X11
static void init_startup_info( KStartupInfoId& id, const char* bin,
    int envc, const char* envs )
{
    const char* dpy = get_env_var( DISPLAY"=", envc, envs );
    // this may be called in a child, so it can't use display open using X11display
    // also needed for multihead
    X11_startup_notify_display = XOpenDisplay( dpy );
    if( X11_startup_notify_display == NULL )
        return;
    X11_startup_notify_fd = XConnectionNumber( X11_startup_notify_display );
    KStartupInfoData data;
    int desktop = get_current_desktop( X11_startup_notify_display );
    data.setDesktop( desktop );
    data.setBin(QFile::decodeName(bin));
    KStartupInfo::sendChangeX( X11_startup_notify_display, id, data );
    XFlush( X11_startup_notify_display );
}

static void complete_startup_info( KStartupInfoId& id, pid_t pid )
{
    if( X11_startup_notify_display == NULL )
        return;
    if( pid == 0 ) // failure
        KStartupInfo::sendFinishX( X11_startup_notify_display, id );
    else
    {
        KStartupInfoData data;
        data.addPid( pid );
        data.setHostname();
        KStartupInfo::sendChangeX( X11_startup_notify_display, id, data );
    }
    XCloseDisplay( X11_startup_notify_display );
    X11_startup_notify_display = NULL;
    X11_startup_notify_fd = -1;
}
#endif

static QByteArray execpath_avoid_loops( const QByteArray& exec, int envc, const char* envs, bool avoid_loops )
{
     QStringList paths;
     static const QChar pathSep = QChar::fromLatin1(':');
     if( envc > 0 ) /* use the passed environment */
     {
         const char* path = get_env_var( "PATH=", envc, envs );
         if( path != NULL )
             paths = QFile::decodeName(path).split(pathSep);
     } else {
         paths = QString::fromLocal8Bit(qgetenv("PATH")).split(pathSep, QString::KeepEmptyParts);
     }
     QString execpath = s_instance->dirs()->findExe(QFile::decodeName(exec), paths.join(pathSep));
     if (avoid_loops && !execpath.isEmpty()) {
         const int pos = execpath.lastIndexOf(QLatin1Char('/'));
         const QString bin_path = execpath.left(pos);
         for( QStringList::Iterator it = paths.begin();
              it != paths.end();
              ++it ) {
             if( *it == bin_path || *it == bin_path + QLatin1Char('/')) {
                 paths.erase( it );
                 break; // -->
             }
         }
         execpath = s_instance->dirs()->findExe(QFile::decodeName(exec), paths.join(pathSep));
     }
     return QFile::encodeName(execpath);
}

static pid_t launch(int argc, const char *_name, const char *args,
                    const char *cwd=0, int envc=0, const char *envs=0,
                    const char *tty=0, bool avoid_loops = false,
                    const char* startup_id_str = "0" ) // krazy:exclude=doublequote_chars
{
    QString lib;
    QByteArray name;
    QByteArray exec;
    QString libpath;
    QByteArray execpath;

    if (_name[0] != '/') {
        name = _name;
        lib = QFile::decodeName(name);
        exec = name;
        KPluginLoader klib(lib, *s_instance );
        libpath = klib.fileName();
        execpath = execpath_avoid_loops(exec, envc, envs, avoid_loops);
    } else {
        name = _name;
        lib = QFile::decodeName(name);
        name = name.mid(name.lastIndexOf('/') + 1);
        exec = _name;
        if (lib.endsWith(QLatin1String(".so")))
            libpath = lib;
        else {
            execpath = exec;
        }
    }
#ifndef NDEBUG
    fprintf(stderr,"kdeinit4: preparing to launch %s\n", libpath.isEmpty()
        ? execpath.constData() : libpath.toUtf8().constData());
#endif
    if (!args) {
        argc = 1;
    }

  if (0 > pipe(d.fd))
  {
     perror("kdeinit4: pipe() failed");
     d.result = 3;
     d.errorMsg = i18n("Unable to start new process.\n"
                       "The system may have reached the maximum number of open files possible or the maximum number of open files that you are allowed to use has been reached.").toUtf8();
     d.fork = 0;
     return d.fork;
  }

#ifdef Q_WS_X11
  KStartupInfoId startup_id;
  startup_id.initId( startup_id_str );
  if( !startup_id.none())
      init_startup_info( startup_id, name, envc, envs );
#endif
  // find out this path before forking, doing it afterwards
  // crashes on some platforms, notably OSX

  d.errorMsg = 0;
  d.fork = fork();
  switch(d.fork) {
  case -1:
     perror("kdeinit4: fork() failed");
     d.result = 3;
     d.errorMsg = i18n("Unable to create new process.\n"
                       "The system may have reached the maximum number of processes possible or the maximum number of processes that you are allowed to use has been reached.").toUtf8();
     close(d.fd[0]);
     close(d.fd[1]);
     d.fork = 0;
     break;
  case 0:
  {
     // Child
     close(d.fd[0]);
     close_fds();

     // Try to chdir, either to the requested directory or to the user's document path by default.
     // We ignore errors - if you write a desktop file with Exec=foo and Path=/doesnotexist,
     // we still want to execute `foo` even if the chdir() failed.
     if (cwd && *cwd) {
         (void)chdir(cwd);
     }

     for (int i = 0;  i < envc; i++)
     {
        putenv((char *)envs);
        while(*envs != 0) envs++;
        envs++;
     }

#ifdef Q_WS_X11
      if( startup_id.none())
          KStartupInfo::resetStartupEnv();
      else
          startup_id.setupStartupEnv();
#endif
     {
       int r;
       QByteArray procTitle;
       d.argv = (char **) malloc(sizeof(char *) * (argc+1));
       d.argv[0] = (char *) _name;
       for (int i = 1;  i < argc; i++)
       {
          d.argv[i] = (char *) args;
          procTitle += ' ';
          procTitle += (char *) args;
          while(*args != 0) args++;
          args++;
       }
       d.argv[argc] = 0;

#ifndef SKIP_PROCTITLE
       // Give the process a new name
#ifdef Q_OS_LINUX
       // Set the process name so that killall works like intended
       r = prctl(PR_SET_NAME, (unsigned long) name.data(), 0, 0, 0);
       if ( r == 0 )
           proctitle_set( "%s [kdeinit]%s", name.data(), procTitle.data() ? procTitle.data() : "" );
       else
           proctitle_set( "kdeinit4: %s%s", name.data(), procTitle.data() ? procTitle.data() : "" );
#else
       proctitle_set( "kdeinit4: %s%s", name.data(), procTitle.data() ? procTitle.data() : "" );
#endif
#endif
     }

     if (libpath.isEmpty() && execpath.isEmpty())
     {
        QString errorMsg = i18n("Could not find '%1' executable.", QFile::decodeName(_name));
        exitWithErrorMsg(errorMsg);
     }

     QLibrary l(libpath);

     if ( !libpath.isEmpty() )
     {
       if (!l.load() || !l.isLoaded() )
       {
          QString ltdlError (l.errorString());
          if (execpath.isEmpty())
          {
             // Error
             QString errorMsg = i18n("Could not open library '%1'.\n%2", libpath, ltdlError);
             exitWithErrorMsg(errorMsg);
          }
          else
          {
             // Print warning
             fprintf(stderr, "Could not open library %s: %s\n", qPrintable(lib),
                     qPrintable(ltdlError) );
          }
       }
     }
     if (!l.isLoaded())
     {
        d.result = 2; // Try execing
        write(d.fd[1], &d.result, 1);

        // We set the close on exec flag.
        // Closing of d.fd[1] indicates that the execvp succeeded!
        fcntl(d.fd[1], F_SETFD, FD_CLOEXEC);

        setup_tty( tty );

        if (!execpath.isEmpty())
           execvp(execpath.constData(), d.argv);

        d.result = 1; // Error
        write(d.fd[1], &d.result, 1);
        close(d.fd[1]);
        exit(255);
     }

    void * sym = l.resolve( "kdemain" );
    if ( !sym )
    {
        QString ltdlError = l.errorString();
        fprintf(stderr, "Could not find kdemain: %s\n", qPrintable(ltdlError) );
            QString errorMsg = i18n("Could not find 'kdemain' in '%1'.\n%2",
                                    libpath, ltdlError);
            exitWithErrorMsg(errorMsg);
    }

     d.result = 0; // Success
     write(d.fd[1], &d.result, 1);
     close(d.fd[1]);

     d.func = (int (*)(int, char *[])) sym;
     if (d.debug_wait)
     {
        fprintf(stderr, "kdeinit4: Suspending process\n"
                        "kdeinit4: 'gdb kdeinit4 %d' to debug\n"
                        "kdeinit4: 'kill -SIGCONT %d' to continue\n",
                        getpid(), getpid());
        kill(getpid(), SIGSTOP);
     }
     else
     {
        setup_tty( tty );
     }

     exit( d.func(argc, d.argv)); /* Launch! */

     break;
  }
  default:
     // Parent
     close(d.fd[1]);
     bool exec = false;
     for(;;)
     {
       d.n = read(d.fd[0], &d.result, 1);
       if (d.n == 1)
       {
          if (d.result == 2)
          {
#ifndef NDEBUG
             //fprintf(stderr, "kdeinit4: no kdeinit module, trying exec....\n");
#endif
             exec = true;
             continue;
          }
          if (d.result == 3)
          {
             int l = 0;
             d.n = read(d.fd[0], &l, sizeof(int));
             if (d.n == sizeof(int))
             {
                QByteArray tmp;
                tmp.resize(l+1);
                d.n = read(d.fd[0], tmp.data(), l);
                tmp[l] = 0;
                if (d.n == l)
                   d.errorMsg = tmp;
             }
          }
          // Finished
          break;
       }
       if (d.n == -1)
       {
          if (errno == ECHILD) {  // a child died.
             continue;
          }
          if (errno == EINTR || errno == EAGAIN) { // interrupted or more to read
             continue;
          }
       }
       if (d.n == 0)
       {
          if (exec) {
             d.result = 0;
          } else {
             fprintf(stderr,"kdeinit4: (%s %s) Pipe closed unexpectedly", name.constData(), execpath.constData());
             perror("kdeinit4: Pipe closed unexpectedly");
             d.result = 1; // Error
          }
          break;
       }
       perror("kdeinit4: Error reading from pipe");
       d.result = 1; // Error
       break;
     }
     close(d.fd[0]);
  }
#ifdef Q_WS_X11
  if( !startup_id.none())
  {
     if( d.fork && d.result == 0 ) // launched successfully
        complete_startup_info( startup_id, d.fork );
     else // failure, cancel ASN
        complete_startup_info( startup_id, 0 );
  }
#endif
  return d.fork;
}

extern "C" {

static void sig_child_handler(int)
{
   /*
    * Write into the pipe of death.
    * This way we are sure that we return from the select()
    *
    * A signal itself causes select to return as well, but
    * this creates a race-condition in case the signal arrives
    * just before we enter the select.
    */
   char c = 0;
   write(d.deadpipe[1], &c, 1);
}

}

static void init_signals()
{
  struct sigaction act;
  long options;

  if (pipe(d.deadpipe) != 0)
  {
     perror("kdeinit4: Aborting. Can not create pipe");
     exit(255);
  }

  options = fcntl(d.deadpipe[0], F_GETFL);
  if (options == -1)
  {
     perror("kdeinit4: Aborting. Can not make pipe non-blocking");
     exit(255);
  }

  if (fcntl(d.deadpipe[0], F_SETFL, options | O_NONBLOCK) == -1)
  {
     perror("kdeinit4: Aborting. Can not make pipe non-blocking");
     exit(255);
  }

  /*
   * A SIGCHLD handler is installed which sends a byte into the
   * pipe of death. This is to ensure that a dying child causes
   * an exit from select().
   */
  act.sa_handler=sig_child_handler;
  sigemptyset(&(act.sa_mask));
  sigaddset(&(act.sa_mask), SIGCHLD);
  sigprocmask(SIG_UNBLOCK, &(act.sa_mask), 0L);
  act.sa_flags = SA_NOCLDSTOP;

  // CC: take care of SunOS which automatically restarts interrupted system
  // calls (and thus does not have SA_RESTART)

#ifdef SA_RESTART
  act.sa_flags |= SA_RESTART;
#endif
  sigaction( SIGCHLD, &act, 0L);

  act.sa_handler=SIG_IGN;
  sigemptyset(&(act.sa_mask));
  sigaddset(&(act.sa_mask), SIGPIPE);
  sigprocmask(SIG_UNBLOCK, &(act.sa_mask), 0L);
  act.sa_flags = 0;
  sigaction( SIGPIPE, &act, 0L);
}

static void shutdown_kdeinit()
{
  QT_SOCKLEN_T socklen;

  /** Test if socket file is already present
   *  note that access() resolves symlinks, and so we check the actual
   *  socket file if it exists
   */
  if (access(sock_file, W_OK) == 0)
  {
     int s;
     struct sockaddr_un server;

//     fprintf(stderr, "kdeinit4: Warning, socket_file already exists!\n");
     // Create the socket stream
     s = socket(PF_UNIX, SOCK_STREAM, 0);
     if (s < 0)
     {
        perror("socket() failed");
        exit(255);
     }
     server.sun_family = AF_UNIX;
     strcpy(server.sun_path, sock_file);
     socklen = sizeof(server);

     if(connect(s, (struct sockaddr *)&server, socklen) == 0)
     {
        fprintf(stderr, "kdeinit4: Shutting down running client.\n");
        klauncher_header request_header;
        request_header.cmd = LAUNCHER_TERMINATE_KDEINIT;
        request_header.arg_length = 0;
        write(s, &request_header, sizeof(request_header));
        sleep(1); // Give it some time
     }
     close(s);
  }

  // Delete any stale socket file (and symlink)
  unlink(sock_file);
}

static void init_kdeinit_socket()
{
  struct sockaddr_un sa;
  QT_SOCKLEN_T socklen;
  long options;
  const QByteArray home_dir = qgetenv("HOME");
  int max_tries = 10;
  if (home_dir.isEmpty())
  {
     fprintf(stderr, "kdeinit4: Aborting. $HOME not set!");
     exit(255);
  }
  if (chdir(home_dir) != 0) {
     fprintf(stderr, "kdeinit4: Aborting. Couldn't enter '%s'!", home_dir.constData());
     exit(255);
  }

  {
     QByteArray path = home_dir;
     QByteArray readOnly = qgetenv("KDE_HOME_READONLY");
     if (access(path.data(), R_OK|W_OK))
     {
       if (errno == ENOENT)
       {
          fprintf(stderr, "kdeinit4: Aborting. $HOME directory (%s) does not exist.\n", path.data());
          exit(255);
       }
       else if (readOnly.isEmpty())
       {
          fprintf(stderr, "kdeinit4: Aborting. No write access to $HOME directory (%s).\n", path.data());
          exit(255);
       }
     }
#if 0 // obsolete in kde4. Should we check writing to another file instead?
     path = qgetenv("ICEAUTHORITY");
     if (path.isEmpty())
     {
        path = home_dir;
        path += "/.ICEauthority";
     }
     if (access(path.data(), R_OK|W_OK) && (errno != ENOENT))
     {
       fprintf(stderr, "kdeinit4: Aborting. No write access to '%s'.\n", path.data());
       exit(255);
     }
#endif
  }

  shutdown_kdeinit();

  // Create socket
  d.wrapper = socket(PF_UNIX, SOCK_STREAM, 0);
  if (d.wrapper < 0)
  {
     perror("kdeinit4: Aborting. socket() failed");
     exit(255);
  }

  options = fcntl(d.wrapper, F_GETFL);
  if (options == -1)
  {
     perror("kdeinit4: Aborting. Can not make socket non-blocking");
     close(d.wrapper);
     exit(255);
  }

  if (fcntl(d.wrapper, F_SETFL, options | O_NONBLOCK) == -1)
  {
     perror("kdeinit4: Aborting. Can not make socket non-blocking");
     close(d.wrapper);
     exit(255);
  }

  while (1) {
      // Bind it
      socklen = sizeof(sa);
      memset(&sa, 0, socklen);
      sa.sun_family = AF_UNIX;
      strcpy(sa.sun_path, sock_file);
      if(bind(d.wrapper, (struct sockaddr *)&sa, socklen) != 0)
      {
          if (max_tries == 0) {
              perror("kdeinit4: Aborting. bind() failed");
              fprintf(stderr, "Could not bind to socket '%s'\n", sock_file);
              close(d.wrapper);
              exit(255);
          }
          max_tries--;
      } else
          break;
  }

  // Set permissions
  if (chmod(sock_file, 0600) != 0)
  {
     perror("kdeinit4: Aborting. Can not set permissions on socket");
     fprintf(stderr, "Wrong permissions of socket '%s'\n", sock_file);
     unlink(sock_file);
     close(d.wrapper);
     exit(255);
  }

  if(listen(d.wrapper, SOMAXCONN) < 0)
  {
     perror("kdeinit4: Aborting. listen() failed");
     unlink(sock_file);
     close(d.wrapper);
     exit(255);
  }
}

/*
 * Read 'len' bytes from 'sock' into buffer.
 * returns 0 on success, -1 on failure.
 */
static int read_socket(int sock, char *buffer, int len)
{
  ssize_t result;
  int bytes_left = len;
  while ( bytes_left > 0)
  {
     result = read(sock, buffer, bytes_left);
     if (result > 0)
     {
        buffer += result;
        bytes_left -= result;
     }
     else if (result == 0)
        return -1;
     else if ((result == -1) && (errno != EINTR) && (errno != EAGAIN))
        return -1;
  }
  return 0;
}

static void start_klauncher()
{
    if (socketpair(AF_UNIX, SOCK_STREAM, 0, d.launcher) < 0) {
        perror("kdeinit4: socketpair() failed");
        exit(255);
    }
    char args[32];
    strcpy(args, "--fd=");
    sprintf(args + 5, "%d", d.launcher[1]);
    d.launcher_pid = launch( 2, "klauncher", args );
    close(d.launcher[1]);
#ifndef NDEBUG
    fprintf(stderr, "kdeinit4: Launched KLauncher, pid = %ld, result = %d\n",
                    (long) d.launcher_pid, d.result);
#endif
}

static void launcher_died()
{
   if (!d.launcher_ok)
   {
      /* This is bad. */
      fprintf(stderr, "kdeinit4: Communication error with launcher. Exiting!\n");
      ::exit(255);
      return;
   }

   // KLauncher died... restart
#ifndef NDEBUG
   fprintf(stderr, "kdeinit4: KLauncher died unexpectedly.\n");
#endif
   // Make sure it's really dead.
   if (d.launcher_pid)
   {
      kill(d.launcher_pid, SIGKILL);
      sleep(1); // Give it some time
   }

   d.launcher_ok = false;
   d.launcher_pid = 0;
   close(d.launcher[0]);
   d.launcher[0] = -1;

   start_klauncher();
}

static bool handle_launcher_request(int sock, const char *who)
{
   (void)who; // for NDEBUG

   klauncher_header request_header;
   char *request_data = 0L;
   int result = read_socket(sock, (char *) &request_header, sizeof(request_header));
   if (result != 0)
   {
      return false;
   }

   if ( request_header.arg_length != 0 )
   {
       request_data = (char *) malloc(request_header.arg_length);

       result = read_socket(sock, request_data, request_header.arg_length);
       if (result != 0)
       {
           free(request_data);
           return false;
       }
   }

   //kDebug() << "Got cmd" << request_header.cmd << commandToString(request_header.cmd);
   if (request_header.cmd == LAUNCHER_OK)
   {
      d.launcher_ok = true;
   }
   else if (request_header.arg_length &&
      ((request_header.cmd == LAUNCHER_EXEC) ||
       (request_header.cmd == LAUNCHER_EXT_EXEC) ||
       (request_header.cmd == LAUNCHER_EXEC_NEW)))
   {
      pid_t pid;
      klauncher_header response_header;
      long response_data;
      long l;
      memcpy( &l, request_data, sizeof( long ));
      int argc = l;
      const char *name = request_data + sizeof(long);
      const char *args = name + strlen(name) + 1;
      const char *cwd = 0;
      int envc = 0;
      const char *envs = 0;
      const char *tty = 0;
      int avoid_loops = 0;
      const char *startup_id_str = "0"; // krazy:exclude=doublequote_chars

#ifndef NDEBUG
     fprintf(stderr, "kdeinit4: Got %s '%s' from %s.\n",
             commandToString(request_header.cmd),
             name, who);
#endif

      const char *arg_n = args;
      for(int i = 1; i < argc; i++)
      {
        arg_n = arg_n + strlen(arg_n) + 1;
      }

      if( request_header.cmd == LAUNCHER_EXT_EXEC || request_header.cmd == LAUNCHER_EXEC_NEW )
      {
         memcpy( &l, arg_n, sizeof( long ));
         envc = l;
         arg_n += sizeof(long);
         envs = arg_n;
         for(int i = 0; i < envc; i++)
         {
           arg_n = arg_n + strlen(arg_n) + 1;
         }
         memcpy( &l, arg_n, sizeof( long ));
         avoid_loops = l;
         arg_n += sizeof( long );
      }

     if( request_header.cmd == LAUNCHER_EXT_EXEC )
     {
         startup_id_str = arg_n;
         arg_n += strlen( startup_id_str ) + 1;
     }

     if ((request_header.arg_length > (arg_n - request_data)) &&
         (request_header.cmd == LAUNCHER_EXT_EXEC || request_header.cmd == LAUNCHER_EXEC_NEW ))
     {
         // Optional cwd
         cwd = arg_n; arg_n += strlen(cwd) + 1;
     }

     if ((arg_n - request_data) != request_header.arg_length)
     {
#ifndef NDEBUG
       fprintf(stderr, "kdeinit4: EXEC request has invalid format.\n");
#endif
       free(request_data);
       d.debug_wait = false;
       return true; // sure?
     }

      pid = launch( argc, name, args, cwd, envc, envs,
          tty, avoid_loops, startup_id_str );

      if (pid && (d.result == 0))
      {
         response_header.cmd = LAUNCHER_OK;
         response_header.arg_length = sizeof(response_data);
         response_data = pid;
         write(sock, &response_header, sizeof(response_header));
         write(sock, &response_data, response_header.arg_length);

         /* add new child to list */
         struct child *child = (struct child *) malloc(sizeof(struct child));
         child->pid = pid;
         child->sock = dup(sock);
         child->next = children;
         children = child;
      }
      else
      {
         int l = d.errorMsg.length();
         if (l) l++; // Include trailing null.
         response_header.cmd = LAUNCHER_ERROR;
         response_header.arg_length = l;
         write(sock, &response_header, sizeof(response_header));
         if (l)
            write(sock, d.errorMsg.data(), l);
      }
      d.debug_wait = false;
   }
   else if (request_header.arg_length && request_header.cmd == LAUNCHER_SETENV)
   {
      const char *env_name;
      const char *env_value;
      env_name = request_data;
      env_value = env_name + strlen(env_name) + 1;

#ifndef NDEBUG
      fprintf(stderr, "kdeinit4: Got SETENV '%s=%s' from %s.\n", env_name, env_value, who);
#endif

      if ( request_header.arg_length !=
          (int) (strlen(env_name) + strlen(env_value) + 2))
      {
#ifndef NDEBUG
         fprintf(stderr, "kdeinit4: SETENV request has invalid format.\n");
#endif
         free(request_data);
         return true; // sure?
      }
      setenv( env_name, env_value, 1);
   }
   else if (request_header.cmd == LAUNCHER_TERMINATE_KDEINIT)
   {
#ifndef NDEBUG
      fprintf(stderr,"kdeinit4: Got termination request (PID %ld).\n", (long) getpid());
#endif
      if (d.launcher_pid) {
         kill(d.launcher_pid, SIGTERM);
         d.launcher_pid = 0;
         close(d.launcher[0]);
         d.launcher[0] = -1;
      }
      unlink(sock_file);
      if (children) {
         close(d.wrapper);
         d.wrapper = -1;
#ifndef NDEBUG
         fprintf(stderr,"kdeinit4: Closed sockets, but not exiting until all children terminate.\n");
#endif
      } else {
         raise(SIGTERM);
      }
   }
   else if (request_header.cmd == LAUNCHER_DEBUG_WAIT)
   {
#ifndef NDEBUG
       fprintf(stderr,"kdeinit4: Debug wait activated.\n");
#endif
       d.debug_wait = true;
   }
   if (request_data)
       free(request_data);
   return true;
}

static void handle_requests(pid_t waitForPid)
{
   int max_sock = d.deadpipe[0];
   if (d.wrapper > max_sock)
      max_sock = d.wrapper;
   if (d.launcher[0] > max_sock)
      max_sock = d.launcher[0];
#ifdef Q_WS_X11
   if (X11fd > max_sock)
      max_sock = X11fd;
#endif
   max_sock++;

   while(1)
   {
      fd_set rd_set;
      fd_set wr_set;
      fd_set e_set;
      int result;
      pid_t exit_pid;
      int exit_status;
      char c;

      /* Flush the pipe of death */
      while( read(d.deadpipe[0], &c, 1) == 1)
        {}

      /* Handle dying children */
      do {
        exit_pid = waitpid(-1, &exit_status, WNOHANG);
        if (exit_pid > 0)
        {
#ifndef NDEBUG
           fprintf(stderr, "kdeinit4: PID %ld terminated.\n", (long) exit_pid);
#endif
           if (waitForPid && (exit_pid == waitForPid))
              return;

           if( WIFEXITED( exit_status )) // fix process return value
               exit_status = WEXITSTATUS(exit_status);
           else if( WIFSIGNALED(exit_status))
               exit_status = 128 + WTERMSIG( exit_status );
           child_died(exit_pid, exit_status);

           if (d.wrapper < 0 && !children) {
#ifndef NDEBUG
               fprintf(stderr, "kdeinit4: Last child terminated, exiting (PID %ld).\n",
                               (long) getpid());
#endif
               raise(SIGTERM);
           }
        }
      }
      while( exit_pid > 0);

      FD_ZERO(&rd_set);
      FD_ZERO(&wr_set);
      FD_ZERO(&e_set);

      if (d.launcher[0] >= 0)
         FD_SET(d.launcher[0], &rd_set);
      if (d.wrapper >= 0)
         FD_SET(d.wrapper, &rd_set);
      FD_SET(d.deadpipe[0], &rd_set);
#ifdef Q_WS_X11
      if(X11fd >= 0) FD_SET(X11fd, &rd_set);
#endif

      result = select(max_sock, &rd_set, &wr_set, &e_set, 0);
      if (result < 0) {
          if (errno == EINTR || errno == EAGAIN)
              continue;
          perror("kdeinit4: Aborting. select() failed");
          return;
      }

      /* Handle wrapper request */
      if (d.wrapper >= 0 && FD_ISSET(d.wrapper, &rd_set))
      {
         struct sockaddr_un client;
         QT_SOCKLEN_T sClient = sizeof(client);
         int sock = accept(d.wrapper, (struct sockaddr *)&client, &sClient);
         if (sock >= 0)
         {
            d.accepted_fd = sock;
            handle_launcher_request(sock, "wrapper");
            close(sock);
            d.accepted_fd = -1;
         }
      }

      /* Handle launcher request */
      if (d.launcher[0] >= 0 && FD_ISSET(d.launcher[0], &rd_set))
      {
         if (!handle_launcher_request(d.launcher[0], "launcher"))
             launcher_died();
         if (waitForPid == d.launcher_pid)
            return;
      }

#ifdef Q_WS_X11
      /* Look for incoming X11 events */
      if(X11fd >= 0 && FD_ISSET(X11fd,&rd_set)) {
          if (X11display != 0) {
	    XEvent event_return;
	    while (XPending(X11display))
	      XNextEvent(X11display, &event_return);
	  }
      }
#endif
   }
}

static void kdeinit_library_path()
{
   QByteArray display = qgetenv(DISPLAY);
   if (display.isEmpty())
   {
#if defined(Q_WS_X11) || defined(Q_WS_QWS)
     fprintf(stderr, "kdeinit4: Aborting. $" DISPLAY " is not set.\n");
     exit(255);
#endif
   }
   int i;
   if((i = display.lastIndexOf('.')) > display.lastIndexOf(':') && i >= 0)
     display.truncate(i);

   display.replace(':','_');
   // WARNING, if you change the socket name, adjust kwrapper too
   const QString socketFileName = QString::fromLatin1("kdeinit4_%1").arg(QLatin1String(display));
   QByteArray socketName = QFile::encodeName(KStandardDirs::locateLocal("tmp", socketFileName, *s_instance));
   if (socketName.length() >= MAX_SOCK_FILE)
   {
     fprintf(stderr, "kdeinit4: Aborting. Socket name will be too long:\n");
     fprintf(stderr, "         '%s'\n", socketName.data());
     exit(255);
   }
   strcpy(sock_file, socketName.data());
}

int kdeinit_xio_errhandler( Display *disp )
{
    // disp is 0L when KDE shuts down. We don't want those warnings then.
    if ( disp )
       kWarning() << "Fatal IO error: client killed";

    if (sock_file[0])
    {
      // Delete any stale socket file
      unlink(sock_file);
    }

    // Don't kill our children in suicide mode, they may still be in use
    if (d.suicide)
    {
       if (d.launcher_pid)
          kill(d.launcher_pid, SIGTERM);
       exit( 0 );
    }

    if ( disp )
       kWarning() << "Sending SIGHUP to children.";

    // this should remove all children we started
    KDE_signal(SIGHUP, SIG_IGN);
    kill(0, SIGHUP);

    sleep(2);

    if ( disp )
       kWarning() << "Sending SIGTERM to children.";

    // And if they don't listen to us, this should work
    KDE_signal(SIGTERM, SIG_IGN);
    kill(0, SIGTERM);

    if ( disp )
       kWarning() << "Exit.";

    exit( 0 );
    return 0;
}

#ifdef Q_WS_X11
int kdeinit_x_errhandler( Display *dpy, XErrorEvent *err )
{
#ifndef NDEBUG
    char errstr[256];
    // kdeinit almost doesn't use X, and therefore there shouldn't be any X error
    XGetErrorText( dpy, err->error_code, errstr, 256 );
    fprintf(stderr, "kdeinit4(%d) : KDE detected X Error: %s %d\n"
                    "         Major opcode: %d\n"
                    "         Minor opcode: %d\n"
                    "         Resource id:  0x%lx\n",
            getpid(), errstr, err->error_code, err->request_code, err->minor_code, err->resourceid );

    //kDebug() << kBacktrace();

#else
    Q_UNUSED(dpy);
    Q_UNUSED(err);
#endif
    return 0;
}
#endif

#ifdef Q_WS_X11
// needs to be done sooner than initXconnection() because of also opening
// another X connection for startup notification purposes
static void setupX()
{
    XSetIOErrorHandler(kdeinit_xio_errhandler);
    XSetErrorHandler(kdeinit_x_errhandler);
/*
    Handle the tricky case of running via kdesudo/su/sudo/etc. There the usual case
    is that kdesudo (etc.) creates a file with xauth information, sets XAUTHORITY,
    runs the command and removes the xauth file after the command finishes. However,
    dbus and kdeinit daemon currently don't clean up properly and keeping running.
    Which means that running a KDE app via kdesudo the second time talks to kdeinit
    with obsolete xauth information, which makes it unable to connect to X or launch
    any X11 applications.
    Even fixing the cleanup probably wouldn't be sufficient, since it'd be possible to
    launch one kdesudo session, another one, exit the first one and the app from the second
    session would be using kdeinit from the first one.
    So the trick here is to duplicate the xauth file to another file in KDE's tmp
    location, make the file have a consistent name so that future sessions will use it
    as well, point XAUTHORITY there and never remove the file (except for possible
    tmp cleanup).
*/
    if( !qgetenv( "XAUTHORITY" ).isEmpty()) {
        QByteArray display = qgetenv( DISPLAY );
        int i;
        if((i = display.lastIndexOf('.')) > display.lastIndexOf(':') && i >= 0)
            display.truncate(i);
        display.replace(':','_');
        QString xauth = s_instance->dirs()->saveLocation( "tmp" ) + QLatin1String( "xauth-" )
            + QString::number( getuid()) + QLatin1String( "-" ) + QString::fromLocal8Bit( display );
        KSaveFile xauthfile( xauth );
        QFile xauthfrom( QFile::decodeName( qgetenv( "XAUTHORITY" )));
        if( !xauthfrom.open( QFile::ReadOnly ) || !xauthfile.open( QFile::WriteOnly )
            || xauthfile.write( xauthfrom.readAll()) != xauthfrom.size() || !xauthfile.finalize()) {
            xauthfile.abort();
        } else {
            setenv( "XAUTHORITY", QFile::encodeName( xauth ), true );
        }
    }
}

// Borrowed from kdebase/kaudio/kaudioserver.cpp
static int initXconnection()
{
  X11display = XOpenDisplay(NULL);
  if ( X11display != 0 ) {
    XCreateSimpleWindow(X11display, DefaultRootWindow(X11display), 0,0,1,1, \
        0,
        BlackPixelOfScreen(DefaultScreenOfDisplay(X11display)),
        BlackPixelOfScreen(DefaultScreenOfDisplay(X11display)) );
#ifndef NDEBUG
    fprintf(stderr, "kdeinit4: opened connection to %s\n", DisplayString(X11display));
#endif
    int fd = XConnectionNumber( X11display );
    int on = 1;
    (void) setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (char *) &on, (int) sizeof(on));
    return fd;
  } else
    fprintf(stderr, "kdeinit4: Can not connect to the X Server.\n" \
     "kdeinit4: Might not terminate at end of session.\n");

  return -1;
}
#endif

extern "C" {

static void secondary_child_handler(int)
{
   waitpid(-1, 0, WNOHANG);
}

}

int main(int argc, char **argv)
{
    setlocale (LC_ALL, "");
    setlocale (LC_NUMERIC, "C");

   pid_t pid;
   bool do_fork = true;
   int launch_klauncher = 1;
   int do_shutdown = 0;
   d.suicide = false;

   // Save arguments first...
   char **safe_argv = (char **) malloc( sizeof(char *) * argc);
   for(int i = 0; i < argc; i++)
   {
      safe_argv[i] = strcpy((char*)malloc(strlen(argv[i])+1), argv[i]);
      if (strcmp(safe_argv[i], "--no-klauncher") == 0)
         launch_klauncher = 0;
      if (strcmp(safe_argv[i], "--no-fork") == 0)
         do_fork = false;
      if (strcmp(safe_argv[i], "--suicide") == 0)
         d.suicide = true;
      if (strcmp(safe_argv[i], "--shutdown") == 0)
         do_shutdown = 1;
      if (strcmp(safe_argv[i], "--version") == 0)
      {
         printf("Katie: %s\n", qVersion());
         printf("KDE: %s\n", KDE_VERSION_STRING);
         exit(0);
      }
      if (strcmp(safe_argv[i], "--help") == 0)
      {
        printf("Usage: kdeinit4 [options]\n");
        printf("    --no-fork         Do not fork\n");
        printf("    --no-klauncher    Do not start klauncher\n");
        printf("    --suicide         Terminate when no KDE applications are left running\n");
        printf("    --version         Show version information\n");
        printf("    --shutdown        Shutdown running kdeinit4 instance\n");
        exit(0);
      }
   }

   if (do_shutdown) {
      KDE_signal(SIGPIPE, SIG_IGN);
      s_instance = new KComponentData("kdeinit4", QByteArray(), KComponentData::SkipMainComponentRegistration);
      kdeinit_library_path();
      shutdown_kdeinit();
      return 0;
   }

   cleanup_fds();

   // Redirect stdout to stderr. We have no reason to use stdout anyway.
   // This minimizes our impact on commands used in pipes.
   (void)dup2(2, 1);

   if (do_fork) {
      if (pipe(d.initpipe) != 0) {
          perror("kdeinit4: pipe failed");
          return 1;
      }

      // Fork here and let parent process exit.
      // Parent process may only exit after all required services have been
      // launched. (dcopserver/klauncher and services which start with '+')
      KDE_signal( SIGCHLD, secondary_child_handler);
      if (fork() > 0) // Go into background
      {
         close(d.initpipe[1]);
         d.initpipe[1] = -1;
         // wait till init is complete
         char c;
         while( read(d.initpipe[0], &c, 1) < 0)
            ;
         // then exit;
         close(d.initpipe[0]);
         d.initpipe[0] = -1;
         return 0;
      }
      close(d.initpipe[0]);
      d.initpipe[0] = -1;
   }

   // Make process group leader (for shutting down children later)
   setsid();

   // Create our instance
   s_instance = new KComponentData("kdeinit4", QByteArray(), KComponentData::SkipMainComponentRegistration);

   // Prepare to change process name
#ifndef SKIP_PROCTITLE
   proctitle_init(argc, argv);
#endif

   kdeinit_library_path();
   // Don't make our instance the global instance
   // (do it only after kdeinit_library_path, that one indirectly uses KConfig,
   // which seems to be buggy and always use KGlobal instead of the matching KComponentData)
   Q_ASSERT(!KGlobal::hasMainComponent());
   // don't change envvars before proctitle_init()
   unsetenv("LD_BIND_NOW");

   d.maxname = strlen(argv[0]);
   d.launcher_pid = 0;
   d.wrapper = -1;
   d.accepted_fd = -1;
   d.debug_wait = false;
   d.launcher_ok = false;
   children = NULL;
   init_signals();
#ifdef Q_WS_X11
   setupX();
#endif

   // Create socket for incoming wrapper requests
   init_kdeinit_socket();

   if (launch_klauncher)
   {
      start_klauncher();
      handle_requests(d.launcher_pid); // Wait for klauncher to be ready
   }

#ifdef Q_WS_X11
   X11fd = initXconnection();
#endif

   for(int i = 1; i < argc; i++)
   {
      if (safe_argv[i][0] == '+')
      {
         pid = launch( 1, safe_argv[i]+1, 0);
#ifndef NDEBUG
      fprintf(stderr, "kdeinit4: Launched '%s', pid = %ld result = %d\n", safe_argv[i]+1, (long) pid, d.result);
#endif
         handle_requests(pid);
      }
      else if (safe_argv[i][0] == '-')
      {
         // Ignore
      }
      else
      {
         pid = launch( 1, safe_argv[i], 0 );
#ifndef NDEBUG
      fprintf(stderr, "kdeinit4: Launched '%s', pid = %ld result = %d\n", safe_argv[i], (long) pid, d.result);
#endif
      }
   }

   // Free argumentsf
   for(int i = 0; i < argc; i++)
   {
      free(safe_argv[i]);
   }
   free (safe_argv);

#ifndef SKIP_PROCTITLE
   proctitle_set("kdeinit4 Running...");
#endif

   if (d.initpipe[1] != -1)
   {
      char c = 0;
      write(d.initpipe[1], &c, 1); // Kdeinit is started.
      close(d.initpipe[1]);
      d.initpipe[1] = -1;
   }

   handle_requests(0);

   return 0;
}