check that the version of __sync_sub_and_fetch that returns a value is supported...

[wxWidgets.git] / src / unix / snglinst.cpp

diff --git a/src/unix/snglinst.cpp b/src/unix/snglinst.cpp
index ccb6788d1191694589be62ba26e3f0509418355f..26bab35d8bcdfb1120637ce42fd8e25433bfeb83 100644 (file)
--- a/src/unix/snglinst.cpp
+++ b/src/unix/snglinst.cpp
@@ -1,5 +1,5 @@
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////

-// Name:        unix/snglinst.cpp
+// Name:        src/unix/snglinst.cpp

 // Purpose:     implements wxSingleInstanceChecker class for Unix using
 //              lock files with fcntl(2) or flock(2)
 // Author:      Vadim Zeitlin
 // Purpose:     implements wxSingleInstanceChecker class for Unix using
 //              lock files with fcntl(2) or flock(2)
 // Author:      Vadim Zeitlin


@@ -7,7 +7,7 @@
 // Created:     09.06.01
 // RCS-ID:      $Id$
 // Copyright:   (c) 2001 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
 // Created:     09.06.01
 // RCS-ID:      $Id$
 // Copyright:   (c) 2001 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>

-// License:     wxWindows license
+// License:     wxWindows licence

 ///////////////////////////////////////////////////////////////////////////////
 
 // ============================================================================
 ///////////////////////////////////////////////////////////////////////////////
 
 // ============================================================================


@@ -18,10 +18,6 @@
 // headers
 // ----------------------------------------------------------------------------
 
 // headers
 // ----------------------------------------------------------------------------
 

-#ifdef __GNUG__
-    #pragma implementation "snglinst.h"
-#endif
-

 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 


@@ -35,16 +31,16 @@
     #include "wx/string.h"
     #include "wx/log.h"
     #include "wx/intl.h"
     #include "wx/string.h"
     #include "wx/log.h"
     #include "wx/intl.h"

-    #include "wx/file.h"
+    #include "wx/utils.h"           // wxGetHomeDir()

 #endif //WX_PRECOMP
 
 #endif //WX_PRECOMP
 

-#include "wx/utils.h"           // wxGetHomeDir()
+#include "wx/file.h"

 
 #include "wx/snglinst.h"
 
 #include <unistd.h>
 #include <sys/types.h>
 
 #include "wx/snglinst.h"
 
 #include <unistd.h>
 #include <sys/types.h>

-#include <sys/stat.h>
+#include <sys/stat.h>           // for S_I[RW]USR

 #include <signal.h>             // for kill()
 #include <errno.h>
 
 #include <signal.h>             // for kill()
 #include <errno.h>
 


@@ -89,9 +85,9 @@ static int wxLockFile(int fd, LockOperation lock)
     fl.l_type = lock == LOCK ? F_WRLCK : F_UNLCK;
 
     // lock the entire file
     fl.l_type = lock == LOCK ? F_WRLCK : F_UNLCK;
 
     // lock the entire file

-    fl.l_whence =

     fl.l_start =
     fl.l_start =

-    fl.l_len = 0;
+    fl.l_len =
+    fl.l_whence = 0;

 
     // is this needed?
     fl.l_pid = getpid();
 
     // is this needed?
     fl.l_pid = getpid();


@@ -151,15 +147,14 @@ private:
 LockResult wxSingleInstanceCheckerImpl::CreateLockFile()
 {
     // try to open the file
 LockResult wxSingleInstanceCheckerImpl::CreateLockFile()
 {
     // try to open the file

-    m_fdLock = open(m_nameLock,
+    m_fdLock = open(m_nameLock.fn_str(),

                     O_WRONLY | O_CREAT | O_EXCL,
                     O_WRONLY | O_CREAT | O_EXCL,

-                    S_IREAD | S_IWRITE);
+                    S_IRUSR | S_IWUSR);

 
     if ( m_fdLock != -1 )
     {
         // try to lock it
 
     if ( m_fdLock != -1 )
     {
         // try to lock it

-        int rc = wxLockFile(m_fdLock, LOCK);
-        if ( rc == 0 )
+        if ( wxLockFile(m_fdLock, LOCK) == 0 )

         {
             // fine, we have the exclusive lock to the file, write our PID
             // into it
         {
             // fine, we have the exclusive lock to the file, write our PID
             // into it


@@ -181,6 +176,17 @@ LockResult wxSingleInstanceCheckerImpl::CreateLockFile()
 
             fsync(m_fdLock);
 
 
             fsync(m_fdLock);
 

+            // change file's permission so that only this user can access it:
+            if ( chmod(m_nameLock.fn_str(), S_IRUSR | S_IWUSR) != 0 )
+            {
+                wxLogSysError(_("Failed to set permissions on lock file '%s'"),
+                              m_nameLock.c_str());
+
+                Unlock();
+
+                return LOCK_ERROR;
+            }
+

             return LOCK_CREATED;
         }
         else // failure: see what exactly happened
             return LOCK_CREATED;
         }
         else // failure: see what exactly happened


@@ -188,12 +194,12 @@ LockResult wxSingleInstanceCheckerImpl::CreateLockFile()
             close(m_fdLock);
             m_fdLock = -1;
 
             close(m_fdLock);
             m_fdLock = -1;
 

-            if ( rc != EACCES && rc != EAGAIN )
+            if ( errno != EACCES && errno != EAGAIN )

             {
                 wxLogSysError(_("Failed to lock the lock file '%s'"),
                               m_nameLock.c_str());
 
             {
                 wxLogSysError(_("Failed to lock the lock file '%s'"),
                               m_nameLock.c_str());
 

-                unlink(m_nameLock);
+                unlink(m_nameLock.fn_str());

 
                 return LOCK_ERROR;
             }
 
                 return LOCK_ERROR;
             }


@@ -220,11 +226,31 @@ bool wxSingleInstanceCheckerImpl::Create(const wxString& name)
 
         case LOCK_CREATED:
             // nothing more to do
 
         case LOCK_CREATED:
             // nothing more to do

-            return TRUE;
+            return true;

 
         case LOCK_ERROR:
             // oops...
 
         case LOCK_ERROR:
             // oops...

-            return FALSE;
+            return false;
+    }
+
+    // Check if the file is owned by current user and has 0600 permissions.
+    // If it doesn't, it's a fake file, possibly meant as a DoS attack, and
+    // so we refuse to touch it:
+    wxStructStat stats;
+    if ( wxStat(name, &stats) != 0 )
+    {
+        wxLogSysError(_("Failed to inspect the lock file '%s'"), name.c_str());
+        return false;
+    }
+    if ( stats.st_uid != getuid() )
+    {
+        wxLogError(_("Lock file '%s' has incorrect owner."), name.c_str());
+        return false;
+    }
+    if ( stats.st_mode != (S_IFREG | S_IRUSR | S_IWUSR) )
+    {
+        wxLogError(_("Lock file '%s' has incorrect permissions."), name.c_str());
+        return false;

     }
 
     // try to open the file for reading and get the PID of the process
     }
 
     // try to open the file for reading and get the PID of the process


@@ -243,11 +269,11 @@ bool wxSingleInstanceCheckerImpl::Create(const wxString& name)
         // rarely in practice that we don't care
         wxLogError(_("Failed to access lock file."));
 
         // rarely in practice that we don't care
         wxLogError(_("Failed to access lock file."));
 

-        return FALSE;
+        return false;

     }
 
     char buf[256];
     }
 
     char buf[256];

-    off_t count = file.Read(buf, WXSIZEOF(buf));
+    ssize_t count = file.Read(buf, WXSIZEOF(buf));

     if ( count == wxInvalidOffset )
     {
         wxLogError(_("Failed to read PID from lock file."));
     if ( count == wxInvalidOffset )
     {
         wxLogError(_("Failed to read PID from lock file."));


@@ -258,12 +284,12 @@ bool wxSingleInstanceCheckerImpl::Create(const wxString& name)
         {
             if ( kill(m_pidLocker, 0) != 0 )
             {
         {
             if ( kill(m_pidLocker, 0) != 0 )
             {

-                if ( unlink(name) != 0 )
+                if ( unlink(name.fn_str()) != 0 )

                 {
                     wxLogError(_("Failed to remove stale lock file '%s'."),
                                name.c_str());
 
                 {
                     wxLogError(_("Failed to remove stale lock file '%s'."),
                                name.c_str());
 

-                    // return TRUE in this case for now...
+                    // return true in this case for now...

                 }
                 else
                 {
                 }
                 else
                 {


@@ -282,7 +308,7 @@ bool wxSingleInstanceCheckerImpl::Create(const wxString& name)
         }
     }
 
         }
     }
 

-    // return TRUE if we could get the PID of the process owning the lock file
+    // return true if we could get the PID of the process owning the lock file

     // (whether it is still running or not), FALSE otherwise as it is
     // unexpected
     return m_pidLocker != 0;
     // (whether it is still running or not), FALSE otherwise as it is
     // unexpected
     return m_pidLocker != 0;


@@ -292,7 +318,7 @@ void wxSingleInstanceCheckerImpl::Unlock()
 {
     if ( m_fdLock != -1 )
     {
 {
     if ( m_fdLock != -1 )
     {

-        if ( unlink(m_nameLock) != 0 )
+        if ( unlink(m_nameLock.fn_str()) != 0 )

         {
             wxLogSysError(_("Failed to remove lock file '%s'"),
                           m_nameLock.c_str());
         {
             wxLogSysError(_("Failed to remove lock file '%s'"),
                           m_nameLock.c_str());


@@ -332,7 +358,12 @@ bool wxSingleInstanceChecker::Create(const wxString& name,
     wxString fullname = path;
     if ( fullname.empty() )
     {
     wxString fullname = path;
     if ( fullname.empty() )
     {

-        fullname << wxGetHomeDir() << _T('/');
+        fullname = wxGetHomeDir();
+    }
+
+    if ( fullname.Last() != _T('/') )
+    {
+        fullname += _T('/');

     }
 
     fullname << name;
     }
 
     fullname << name;


@@ -342,7 +373,7 @@ bool wxSingleInstanceChecker::Create(const wxString& name,
 
 bool wxSingleInstanceChecker::IsAnotherRunning() const
 {
 
 bool wxSingleInstanceChecker::IsAnotherRunning() const
 {

-    wxCHECK_MSG( m_impl, FALSE, _T("must call Create() first") );
+    wxCHECK_MSG( m_impl, false, _T("must call Create() first") );

 
     // if another instance is running, it must own the lock file - otherwise
     // we have it and the locker PID is ours one
 
     // if another instance is running, it must own the lock file - otherwise
     // we have it and the locker PID is ours one


@@ -355,4 +386,3 @@ wxSingleInstanceChecker::~wxSingleInstanceChecker()
 }
 
 #endif // wxUSE_SNGLINST_CHECKER
 }
 
 #endif // wxUSE_SNGLINST_CHECKER

-