apt-pkg/deb/debsystem.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: debsystem.cc,v 1.4 2004/01/26 17:01:53 mdz Exp $
   4 /* ######################################################################
   5
   6    System - Abstraction for running on different systems.
   7
   8    Basic general structure..
   9
  10    ##################################################################### */
  11                                                                         /*}}}*/
  12 // Include Files                                                        /*{{{*/
  13 #include <apt-pkg/debsystem.h>
  14 #include <apt-pkg/debversion.h>
  15 #include <apt-pkg/debindexfile.h>
  16 #include <apt-pkg/dpkgpm.h>
  17 #include <apt-pkg/configuration.h>
  18 #include <apt-pkg/error.h>
  19 #include <apt-pkg/fileutl.h>
  20
  21 #include <sys/types.h>
  22 #include <unistd.h>
  23 #include <dirent.h>
  24 #include <errno.h>
  25                                                                         /*}}}*/
  26
  27 debSystem debSys;
  28
  29 // System::debSystem - Constructor                                      /*{{{*/
  30 // ---------------------------------------------------------------------
  31 /* */
  32 debSystem::debSystem()
  33 {
  34    LockFD = -1;
  35    LockCount = 0;
  36    StatusFile = 0;
  37
  38    Label = "Debian dpkg interface";
  39    VS = &debVS;
  40 }
  41                                                                         /*}}}*/
  42 // System::~debSystem - Destructor                                      /*{{{*/
  43 // ---------------------------------------------------------------------
  44 /* */
  45 debSystem::~debSystem()
  46 {
  47    delete StatusFile;
  48 }
  49                                                                         /*}}}*/
  50 // System::Lock - Get the lock                                          /*{{{*/
  51 // ---------------------------------------------------------------------
  52 /* This mirrors the operations dpkg does when it starts up. Note the
  53    checking of the updates directory. */
  54 bool debSystem::Lock()
  55 {
  56    // Disable file locking
  57    if (_config->FindB("Debug::NoLocking",false) == true || LockCount > 1)
  58    {
  59       LockCount++;
  60       return true;
  61    }
  62
  63    // Create the lockfile
  64    string AdminDir = flNotFile(_config->Find("Dir::State::status"));
  65    LockFD = GetLock(AdminDir + "lock");
  66    if (LockFD == -1)
  67    {
  68       if (errno == EACCES || errno == EAGAIN)
  69          return _error->Error("Unable to lock the administration directory (%s), "
  70                               "is another process using it?",AdminDir.c_str());
  71       else
  72          return _error->Error("Unable to lock the administration directory (%s), "
  73                               "are you root?",AdminDir.c_str());
  74    }
  75
  76    // See if we need to abort with a dirty journal
  77    if (CheckUpdates() == true)
  78    {
  79       close(LockFD);
  80       LockFD = -1;
  81       return _error->Error("dpkg was interrupted, you must manually "
  82                            "run 'dpkg --configure -a' to correct the problem. ");
  83    }
  84
  85          LockCount++;
  86
  87    return true;
  88 }
  89                                                                         /*}}}*/
  90 // System::UnLock - Drop a lock                                         /*{{{*/
  91 // ---------------------------------------------------------------------
  92 /* */
  93 bool debSystem::UnLock(bool NoErrors)
  94 {
  95    if (LockCount == 0 && NoErrors == true)
  96       return false;
  97
  98    if (LockCount < 1)
  99       return _error->Error("Not locked");
 100    if (--LockCount == 0)
 101    {
 102       close(LockFD);
 103       LockCount = 0;
 104    }
 105
 106    return true;
 107 }
 108                                                                         /*}}}*/
 109 // System::CheckUpdates - Check if the updates dir is dirty             /*{{{*/
 110 // ---------------------------------------------------------------------
 111 /* This does a check of the updates directory (dpkg journal) to see if it has
 112    any entries in it. */
 113 bool debSystem::CheckUpdates()
 114 {
 115    // Check for updates.. (dirty)
 116    string File = flNotFile(_config->Find("Dir::State::status")) + "updates/";
 117    DIR *DirP = opendir(File.c_str());
 118    if (DirP == 0)
 119       return false;
 120
 121    /* We ignore any files that are not all digits, this skips .,.. and
 122       some tmp files dpkg will leave behind.. */
 123    bool Damaged = false;
 124    for (struct dirent *Ent = readdir(DirP); Ent != 0; Ent = readdir(DirP))
 125    {
 126       Damaged = true;
 127       for (unsigned int I = 0; Ent->d_name[I] != 0; I++)
 128       {
 129          // Check if its not a digit..
 130          if (isdigit(Ent->d_name[I]) == 0)
 131          {
 132             Damaged = false;
 133             break;
 134          }
 135       }
 136       if (Damaged == true)
 137          break;
 138    }
 139    closedir(DirP);
 140
 141    return Damaged;
 142 }
 143                                                                         /*}}}*/
 144 // System::CreatePM - Create the underlying package manager             /*{{{*/
 145 // ---------------------------------------------------------------------
 146 /* */
 147 pkgPackageManager *debSystem::CreatePM(pkgDepCache *Cache) const
 148 {
 149    return new pkgDPkgPM(Cache);
 150 }
 151                                                                         /*}}}*/
 152 // System::Initialize - Setup the configuration space..                 /*{{{*/
 153 // ---------------------------------------------------------------------
 154 /* These are the Debian specific configuration variables.. */
 155 bool debSystem::Initialize(Configuration &Cnf)
 156 {
 157    /* These really should be jammed into a generic 'Local Database' engine
 158       which is yet to be determined. The functions in pkgcachegen should
 159       be the only users of these */
 160    Cnf.CndSet("Dir::State::userstatus","status.user"); // Defunct
 161    Cnf.CndSet("Dir::State::status","/var/lib/dpkg/status");
 162    Cnf.CndSet("Dir::Bin::dpkg","/usr/bin/dpkg");
 163
 164    if (StatusFile) {
 165      delete StatusFile;
 166      StatusFile = 0;
 167    }
 168
 169    return true;
 170 }
 171                                                                         /*}}}*/
 172 // System::ArchiveSupported - Is a file format supported                /*{{{*/
 173 // ---------------------------------------------------------------------
 174 /* The standard name for a deb is 'deb'.. There are no seperate versions
 175    of .deb to worry about.. */
 176 bool debSystem::ArchiveSupported(const char *Type)
 177 {
 178    if (strcmp(Type,"deb") == 0)
 179       return true;
 180    return false;
 181 }
 182                                                                         /*}}}*/
 183 // System::Score - Determine how 'Debiany' this sys is..                /*{{{*/
 184 // ---------------------------------------------------------------------
 185 /* We check some files that are sure tell signs of this being a Debian
 186    System.. */
 187 signed debSystem::Score(Configuration const &Cnf)
 188 {
 189    signed Score = 0;
 190    if (FileExists(Cnf.FindFile("Dir::State::status","/var/lib/dpkg/status")) == true)
 191        Score += 10;
 192    if (FileExists(Cnf.FindFile("Dir::Bin::dpkg","/usr/bin/dpkg")) == true)
 193       Score += 10;
 194    if (FileExists("/etc/debian_version") == true)
 195       Score += 10;
 196    return Score;
 197 }
 198                                                                         /*}}}*/
 199 // System::AddStatusFiles - Register the status files                   /*{{{*/
 200 // ---------------------------------------------------------------------
 201 /* */
 202 bool debSystem::AddStatusFiles(vector<pkgIndexFile *> &List)
 203 {
 204    if (StatusFile == 0)
 205       StatusFile = new debStatusIndex(_config->FindFile("Dir::State::status"));
 206    List.push_back(StatusFile);
 207    return true;
 208 }
 209                                                                         /*}}}*/
 210 // System::FindIndex - Get an index file for status files               /*{{{*/
 211 // ---------------------------------------------------------------------
 212 /* */
 213 bool debSystem::FindIndex(pkgCache::PkgFileIterator File,
 214                           pkgIndexFile *&Found) const
 215 {
 216    if (StatusFile == 0)
 217       return false;
 218    if (StatusFile->FindInCache(*File.Cache()) == File)
 219    {
 220       Found = StatusFile;
 221       return true;
 222    }
 223
 224    return false;
 225 }
 226                                                                         /*}}}*/