Fixed FTBFS in Debian/Ubuntu due to missing liblockdev1-dev package. Device locking is now done through 'flock()'

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
(cherry picked from commit 3ed5f6bda5dabbb74b0126982cb515de1a8e2558)

1 files changed, 43 insertions, 109 deletions

diff --git a/kandy/src/modem.cpp b/kandy/src/modem.cpp
index 86c36d675..2a275bf4d 100644
--- a/kandy/src/modem.cpp
+++ b/kandy/src/modem.cpp
@@ -30,6 +30,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
+#include <sys/file.h>
 #include <fcntl.h>
 #include <termios.h>
 #include <unistd.h>
@@ -75,10 +76,10 @@
 
 
 Modem::Modem( KandyPrefs *kprefs, TQObject *parent, const char *name ) :
-  TQObject(parent, name)
+  TQObject(parent, name), fd(-1)
 {
   mOpen = false;
-  
+
   prefs = kprefs;
 
   timer = new TQTimer( this, "modemtimer" );
@@ -185,28 +186,31 @@ bool Modem::open()
 {
   struct termios tty;
 
-
   close();
 
-  if ( !lockDevice() )
-    return false;
+	if (fd == -1)
+	{
+		TQCString dev = TQFile::encodeName( (*prefs).serialDevice() );
+		const char *fdev = dev.data();
+		if ( ( fd = ::open( fdev, O_RDWR | O_NOCTTY | O_NONBLOCK ) ) == -1 ) {
+			emit errorMessage( i18n( "Unable to open device '%1'. "
+															"Please check that you have sufficient permissions." )
+															.arg( fdev ) );
+			return false;
+		}
+	}
 
-  TQCString dev = TQFile::encodeName( (*prefs).serialDevice() );
-  const char *fdev = dev.data();
-  if ( ( fd = ::open( fdev, O_RDWR | O_NOCTTY | O_NONBLOCK ) ) == -1 ) {
-    emit errorMessage( i18n( "Unable to open device '%1'. "
-                             "Please check that you have sufficient permissions." )
-                             .arg( fdev ) );
+  if ( !lockDevice() )
     return false;
-  }
 
   tcflush( fd, TCIOFLUSH );
   if ( tcgetattr( fd, &init_tty ) == -1 ) {
     int errnumber = errno;
     emit errorMessage( i18n( "Communication setup failed (tcgetattr code: %1)" )
         .arg(strerror(errnumber)) );
+		unlockDevice();
     ::close( fd );
-    fd = 0;
+    fd = -1;
     return false;
   }
 
@@ -221,8 +225,9 @@ bool Modem::open()
 
   if ( tcsetattr( fd, TCSANOW, &tty ) == -1 ) {
     emit errorMessage( i18n( "tcsetattr() failed." ) );
+		unlockDevice();
     ::close( fd );
-    fd = 0;
+    fd = -1;
     return false;
   }
 
@@ -244,127 +249,56 @@ void Modem::close()
   delete sn;
   sn = 0;
 
+  unlockDevice();
+
   if ( fd ) {
     tcflush( fd, TCIOFLUSH );
     tcsetattr( fd, TCSANOW, &init_tty );
     ::close( fd );
-    fd = 0;
+    fd = -1;
   }
 
   xreset();
 
-  unlockDevice();
-
   mOpen = false;
 }
 
 
 void Modem::flush()
 {
-  if ( fd ) {
+  if ( fd != -1) {
     tcflush( fd, TCIOFLUSH );
     bufpos = 0;
   }
 }
 
-#ifdef HAVE_LOCKDEV
-#include <lockdev.h>
-#endif
-
 bool Modem::lockDevice()
 {
-  if ( is_locked )
+  if (is_locked)
     return true;
 
-#ifdef HAVE_LOCKDEV
-  is_locked = !dev_lock( (*prefs).serialDevice().local8Bit() );
-  if (!is_locked)
-      emit errorMessage( i18n( "Unable to lock device '%1'." ).arg(
-                             (*prefs).serialDevice() ));
-  return is_locked;
-#else
-  ssize_t count;
-  pid_t pid;
-  int lfd;
-  struct passwd *pw;
-  TQStringList pathList;
-  TQString fileName, content;
-
-  pathList = TQStringList::split( "/", (*prefs).serialDevice() );
-  fileName = (*prefs).lockDirectory() + "/LCK.." + pathList.last();
-
-  if ( !access( TQFile::encodeName( fileName ).data(), F_OK ) ) {
-    char buf[256];
-
-
-    if ( ( lfd = ::open( TQFile::encodeName( fileName ), O_RDONLY ) ) < 0 ) {
-      emit errorMessage( i18n( "Unable to open lock file '%1'.")
-                               .arg( fileName ) );
-      return false;
-    }
-
-    count = read( lfd, buf, 79 );
-
-    if ( count < 0 ) {
-       emit errorMessage( i18n( "Unable to read lock file '%1'.")
-                                .arg( fileName ) );
-       ::close( lfd );
-       return false;
-    }
-    buf[ count ] = 0;
-    ::close( lfd );
-
-    count = sscanf( buf, "%d", &pid );
-    if ( ( count != 1 ) || ( pid <= 0 ) ) {
-       emit errorMessage( i18n( "Unable to get PID from file '%1'.")
-                                .arg( fileName ) );
-       return false;
-    }
-
-    if ( !kill( (pid_t) pid, 0 ) ) {
-       emit errorMessage( i18n( "Process with PID %1, which is locking the device, is still running.")
-                                .arg( pid ) );
-       return false;
-    }
-
-    if ( errno != ESRCH ) {
-      emit errorMessage( i18n( "Unable to emit signal to PID of existing lock file.") );
-      return false;
-    }
-  }
-	
-  if ( ( lfd = creat( TQFile::encodeName( fileName ).data(), 0644 ) ) == -1 ) {
-    emit errorMessage( i18n( "Unable to create lock file '%1'. "
-                             "Please check that you have sufficient permissions.")
-                             .arg( fileName ) );
-    return false;
+	if (flock(fd, LOCK_EX))
+	{
+	  // Locking failed
+    is_locked = false;
+    emit errorMessage(i18n("Unable to lock device '%1'.").arg((*prefs).serialDevice()));
+	}
+	else
+	{
+  	is_locked = true;
   }
 
-  pid = (int) getpid();
-  pw = getpwuid( getuid() );
-  content.sprintf( "%08d %s %s", pid, "kandy", pw->pw_name );
-  write( lfd, TQFile::encodeName( content ).data(), content.length() );
-  ::close( lfd );
-
-  is_locked = true;
-
-  return true;
-#endif
+	return is_locked;
 }
 
 
 void Modem::unlockDevice()
 {
-#ifdef HAVE_LOCKDEV
-  dev_unlock( (*prefs).serialDevice().local8Bit(), getpid() );
-#else
-  if ( is_locked ) {
-    TQStringList pathList = TQStringList::split( "/", (*prefs).serialDevice() );
-
-    TQFile::remove( (*prefs).lockDirectory() + "/LCK.." + pathList.last() );
-    is_locked = false;
-  }
-#endif
+  if (fd != -1 && is_locked)
+  {
+		flock(fd, LOCK_UN);
+		is_locked = false;
+	}
 }
 
 
@@ -373,7 +307,7 @@ bool Modem::dsrOn()
   int flags;
 
 
-  if ( !fd ) {
+  if ( fd == -1 ) {
 #ifdef MODEM_DEBUG
     fprintf( stderr, "Modem: dsrOn(): File not open.\n" );
 #endif
@@ -396,7 +330,7 @@ bool Modem::ctsOn()
   int flags;
 
 
-  if ( !fd ) {
+  if ( fd == -1 ) {
 #ifdef MODEM_DEBUG
     fprintf( stderr, "Modem: ctsOn(): File not open.\n" );
 #endif
@@ -640,7 +574,7 @@ void Modem::init()
 {
   is_locked = false;
 
-  fd = 0;
+  fd = -1;
   sn = 0;
 
   cspeed = B38400;
@@ -687,7 +621,7 @@ ushort Modem::calcCRC()
   int i, j;
   ushort c = 0;
 
-	
+
   for ( i = 0; i < xsize; i++ ) {
     c ^= (ushort) buffer[ i ] << 8;
     for ( j = 0; j < 8; j++ )