desktop/source/deployment/misc/lockfile.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <sal/config.h>
  21
  22 #include <memory>
  23
  24 #include <stdlib.h>
  25 #include <time.h>
  26 #ifndef _WIN32
  27 #include <unistd.h>
  28 #else
  29 #if !defined WIN32_LEAN_AND_MEAN
  30 # define WIN32_LEAN_AND_MEAN
  31 #endif
  32 #include <windows.h>
  33 #endif
  34 #include <comphelper/random.hxx>
  35 #include <sal/types.h>
  36 #include <osl/file.hxx>
  37 #include <osl/socket.hxx>
  38 #include <osl/security.hxx>
  39 #include <unotools/bootstrap.hxx>
  40 #include <tools/config.hxx>
  41
  42 #include <lockfile.hxx>
  43
  44 using namespace ::osl;
  45 using namespace ::utl;
  46
  47
  48 static OString impl_getHostname()
  49 {
  50     OString aHost;
  51 #ifdef _WIN32
  52     /*
  53        prevent windows from connecting to the net to get its own
  54        hostname by using the netbios name
  55        */
  56     DWORD sz = MAX_COMPUTERNAME_LENGTH + 1;
  57     auto szHost = std::make_unique<char[]>(sz);
  58     if (GetComputerNameA(szHost.get(), &sz))
  59         aHost = OString(szHost.get());
  60     else
  61         aHost = OString("UNKNOWN");
  62 #else
  63     /* Don't do dns lookup on Linux either */
  64     sal_Char pHostName[1024];
  65
  66     if ( gethostname( pHostName, sizeof( pHostName ) - 1 ) == 0 )
  67     {
  68         pHostName[sizeof( pHostName ) - 1] = '\0';
  69         aHost = OString( pHostName );
  70     }
  71     else
  72         aHost = OString("UNKNOWN");
  73 #endif
  74
  75     return aHost;
  76 }
  77
  78 namespace desktop {
  79
  80     Lockfile::Lockfile( bool bIPCserver )
  81     :m_bIPCserver(bIPCserver)
  82     ,m_bRemove(false)
  83     ,m_bIsLocked(false)
  84     {
  85         // build the file-url to use for the lock
  86         OUString aUserPath;
  87         utl::Bootstrap::locateUserInstallation( aUserPath );
  88         m_aLockname = aUserPath + "/.lock";
  89
  90         // generate ID
  91         const int nIdBytes = 16;
  92         char tmpId[nIdBytes*2+1];
  93         time_t t = time(nullptr);
  94         for (int i = 0; i<nIdBytes; i++) {
  95             int tmpByte = comphelper::rng::uniform_int_distribution(0, 0xFF);
  96             sprintf( tmpId+i*2, "%02X", tmpByte );
  97         }
  98         tmpId[nIdBytes*2]=0x00;
  99         m_aId = OUString::createFromAscii( tmpId );
 100
 101         // generate date string
 102         char *tmpTime = ctime( &t );
 103         if (tmpTime != nullptr) {
 104             m_aDate = OUString::createFromAscii( tmpTime );
 105             sal_Int32 i = m_aDate.indexOf('\n');
 106             if (i > 0)
 107                 m_aDate = m_aDate.copy(0, i);
 108         }
 109
 110
 111         // try to create file
 112         File aFile(m_aLockname);
 113         if (aFile.open( osl_File_OpenFlag_Create ) == File::E_EXIST) {
 114             m_bIsLocked = true;
 115         } else {
 116             // new lock created
 117             aFile.close( );
 118             syncToFile( );
 119             m_bRemove = true;
 120         }
 121     }
 122
 123     bool Lockfile::check( fpExecWarning execWarning )
 124     {
 125
 126         if (m_bIsLocked) {
 127             // lock existed, ask user what to do
 128             if (isStale() ||
 129                 (execWarning != nullptr && (*execWarning)( this ))) {
 130                 // remove file and create new
 131                 File::remove( m_aLockname );
 132                 File aFile(m_aLockname);
 133                 (void)aFile.open( osl_File_OpenFlag_Create );
 134                 aFile.close( );
 135                 syncToFile( );
 136                 m_bRemove = true;
 137                 return true;
 138             } else {
 139                 //leave alone and return false
 140                 m_bRemove = false;
 141                 return false;
 142             }
 143         } else {
 144             // lock was created by us
 145             return true;
 146         }
 147     }
 148
 149     bool Lockfile::isStale() const
 150     {
 151         // this checks whether the lockfile was created on the same
 152         // host by the same user. Should this be the case it is safe
 153         // to assume that it is a stale lockfile which can be overwritten
 154         OUString aLockname = m_aLockname;
 155         Config aConfig(aLockname);
 156         aConfig.SetGroup(LOCKFILE_GROUP);
 157         OString aIPCserver  = aConfig.ReadKey( LOCKFILE_IPCKEY );
 158         if (!aIPCserver.equalsIgnoreAsciiCase("true"))
 159             return false;
 160
 161         OString aHost = aConfig.ReadKey( LOCKFILE_HOSTKEY );
 162         OString aUser = aConfig.ReadKey( LOCKFILE_USERKEY );
 163
 164         // lockfile from same host?
 165         OString myHost( impl_getHostname() );
 166         if (aHost == myHost) {
 167             // lockfile by same UID
 168             OUString myUserName;
 169             Security aSecurity;
 170             aSecurity.getUserName( myUserName );
 171             OString myUser(OUStringToOString(myUserName, RTL_TEXTENCODING_ASCII_US));
 172             if (aUser == myUser)
 173                 return true;
 174         }
 175         return false;
 176     }
 177
 178     void Lockfile::syncToFile() const
 179     {
 180         OUString aLockname = m_aLockname;
 181         Config aConfig(aLockname);
 182         aConfig.SetGroup(LOCKFILE_GROUP);
 183
 184         // get information
 185         OString aHost( impl_getHostname() );
 186         OUString aUserName;
 187         Security aSecurity;
 188         aSecurity.getUserName( aUserName );
 189         OString aUser  = OUStringToOString( aUserName, RTL_TEXTENCODING_ASCII_US );
 190         OString aTime  = OUStringToOString( m_aDate, RTL_TEXTENCODING_ASCII_US );
 191         OString aStamp = OUStringToOString( m_aId, RTL_TEXTENCODING_ASCII_US );
 192
 193         // write information
 194         aConfig.WriteKey( LOCKFILE_USERKEY,  aUser );
 195         aConfig.WriteKey( LOCKFILE_HOSTKEY,  aHost );
 196         aConfig.WriteKey( LOCKFILE_STAMPKEY, aStamp );
 197         aConfig.WriteKey( LOCKFILE_TIMEKEY,  aTime );
 198         aConfig.WriteKey(
 199             LOCKFILE_IPCKEY,
 200             m_bIPCserver ? OString("true") : OString("false") );
 201         aConfig.Flush( );
 202     }
 203
 204     Lockfile::~Lockfile()
 205     {
 206         // unlock userdata by removing file
 207         if ( m_bRemove )
 208             File::remove( m_aLockname );
 209     }
 210 }
 211
 212
 213 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */