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 #ifdef __GNUG__
  14 #pragma implementation "apt-pkg/debsystem.h"
  15 #endif
  16
  17 #include <apt-pkg/debsystem.h>
  18 #include <apt-pkg/debversion.h>
  19 #include <apt-pkg/debindexfile.h>
  20 #include <apt-pkg/dpkgpm.h>
  21 #include <apt-pkg/configuration.h>
  22 #include <apt-pkg/error.h>
  23 #include <apt-pkg/fileutl.h>
  24
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27 #include <dirent.h>
  28 #include <errno.h>
  29                                                                         /*}}}*/
  30
  31 debSystem debSys;
  32
  33 // System::debSystem - Constructor                                      /*{{{*/
  34 // ---------------------------------------------------------------------
  35 /* */
  36 debSystem::debSystem()
  37 {
  38    LockFD = -1;
  39    LockCount = 0;
  40    StatusFile = 0;
  41
  42    Label = "Debian dpkg interface";
  43    VS = &debVS;
  44 }
  45                                                                         /*}}}*/
  46 // System::~debSystem - Destructor                                      /*{{{*/
  47 // ---------------------------------------------------------------------
  48 /* */
  49 debSystem::~debSystem()
  50 {
  51    delete StatusFile;
  52 }
  53                                                                         /*}}}*/
  54 // System::Lock - Get the lock                                          /*{{{*/
  55 // ---------------------------------------------------------------------
  56 /* This mirrors the operations dpkg does when it starts up. Note the
  57    checking of the updates directory. */
  58 bool debSystem::Lock()
  59 {
  60    // Disable file locking
  61    if (_config->FindB("Debug::NoLocking",false) == true || LockCount > 1)
  62    {
  63       LockCount++;
  64       return true;
  65    }
  66
  67    // Create the lockfile
  68    string AdminDir = flNotFile(_config->Find("Dir::State::status"));
  69    LockFD = GetLock(AdminDir + "lock");
  70    if (LockFD == -1)
  71    {
  72       if (errno == EACCES || errno == EAGAIN)
  73          return _error->Error("Unable to lock the administration directory (%s), "
  74                               "is another process using it?",AdminDir.c_str());
  75       else
  76          return _error->Error("Unable to lock the administration directory (%s), "
  77                               "are you root?",AdminDir.c_str());
  78    }
  79
  80    // See if we need to abort with a dirty journal
  81    if (CheckUpdates() == true)
  82    {
  83       close(LockFD);
  84       LockFD = -1;
  85       return _error->Error("dpkg was interrupted, you must manually "
  86                            "run 'dpkg --configure -a' to correct the problem. ");
  87    }
  88
  89          LockCount++;
  90
  91    return true;
  92 }
  93                                                                         /*}}}*/
  94 // System::UnLock - Drop a lock                                         /*{{{*/
  95 // ---------------------------------------------------------------------
  96 /* */
  97 bool debSystem::UnLock(bool NoErrors)
  98 {
  99    if (LockCount == 0 && NoErrors == true)
 100       return false;
 101
 102    if (LockCount < 1)
 103       return _error->Error("Not locked");
 104    if (--LockCount == 0)
 105    {
 106       close(LockFD);
 107       LockCount = 0;
 108    }
 109
 110    return true;
 111 }
 112                                                                         /*}}}*/
 113 // System::CheckUpdates - Check if the updates dir is dirty             /*{{{*/
 114 // ---------------------------------------------------------------------
 115 /* This does a check of the updates directory (dpkg journal) to see if it has
 116    any entries in it. */
 117 bool debSystem::CheckUpdates()
 118 {
 119    // Check for updates.. (dirty)
 120    string File = flNotFile(_config->Find("Dir::State::status")) + "updates/";
 121    DIR *DirP = opendir(File.c_str());
 122    if (DirP == 0)
 123       return false;
 124
 125    /* We ignore any files that are not all digits, this skips .,.. and
 126       some tmp files dpkg will leave behind.. */
 127    bool Damaged = false;
 128    for (struct dirent *Ent = readdir(DirP); Ent != 0; Ent = readdir(DirP))
 129    {
 130       Damaged = true;
 131       for (unsigned int I = 0; Ent->d_name[I] != 0; I++)
 132       {
 133          // Check if its not a digit..
 134          if (isdigit(Ent->d_name[I]) == 0)
 135          {
 136             Damaged = false;
 137             break;
 138          }
 139       }
 140       if (Damaged == true)
 141          break;
 142    }
 143    closedir(DirP);
 144
 145    return Damaged;
 146 }
 147                                                                         /*}}}*/
 148 // System::CreatePM - Create the underlying package manager             /*{{{*/
 149 // ---------------------------------------------------------------------
 150 /* */
 151 pkgPackageManager *debSystem::CreatePM(pkgDepCache *Cache) const
 152 {
 153    return new pkgDPkgPM(Cache);
 154 }
 155                                                                         /*}}}*/
 156 // System::Initialize - Setup the configuration space..                 /*{{{*/
 157 // ---------------------------------------------------------------------
 158 /* These are the Debian specific configuration variables.. */
 159 bool debSystem::Initialize(Configuration &Cnf)
 160 {
 161    /* These really should be jammed into a generic 'Local Database' engine
 162       which is yet to be determined. The functions in pkgcachegen should
 163       be the only users of these */
 164    Cnf.CndSet("Dir::State::userstatus","status.user"); // Defunct
 165    Cnf.CndSet("Dir::State::status","/var/lib/dpkg/status");
 166    Cnf.CndSet("Dir::Bin::dpkg","/usr/bin/dpkg");
 167
 168    if (StatusFile) {
 169      delete StatusFile;
 170      StatusFile = 0;
 171    }
 172
 173    return true;
 174 }
 175                                                                         /*}}}*/
 176 // System::ArchiveSupported - Is a file format supported                /*{{{*/
 177 // ---------------------------------------------------------------------
 178 /* The standard name for a deb is 'deb'.. There are no seperate versions
 179    of .deb to worry about.. */
 180 bool debSystem::ArchiveSupported(const char *Type)
 181 {
 182    if (strcmp(Type,"deb") == 0)
 183       return true;
 184    return false;
 185 }
 186                                                                         /*}}}*/
 187 // System::Score - Determine how 'Debiany' this sys is..                /*{{{*/
 188 // ---------------------------------------------------------------------
 189 /* We check some files that are sure tell signs of this being a Debian
 190    System.. */
 191 signed debSystem::Score(Configuration const &Cnf)
 192 {
 193    signed Score = 0;
 194    if (FileExists(Cnf.FindFile("Dir::State::status","/var/lib/dpkg/status")) == true)
 195        Score += 10;
 196    if (FileExists(Cnf.FindFile("Dir::Bin::dpkg","/usr/bin/dpkg")) == true)
 197       Score += 10;
 198    if (FileExists("/etc/debian_version") == true)
 199       Score += 10;
 200    return Score;
 201 }
 202                                                                         /*}}}*/
 203 // System::AddStatusFiles - Register the status files                   /*{{{*/
 204 // ---------------------------------------------------------------------
 205 /* */
 206 bool debSystem::AddStatusFiles(vector<pkgIndexFile *> &List)
 207 {
 208    if (StatusFile == 0)
 209       StatusFile = new debStatusIndex(_config->FindFile("Dir::State::status"));
 210    List.push_back(StatusFile);
 211    return true;
 212 }
 213                                                                         /*}}}*/
 214 // System::FindIndex - Get an index file for status files               /*{{{*/
 215 // ---------------------------------------------------------------------
 216 /* */
 217 bool debSystem::FindIndex(pkgCache::PkgFileIterator File,
 218                           pkgIndexFile *&Found) const
 219 {
 220    if (StatusFile == 0)
 221       return false;
 222    if (StatusFile->FindInCache(*File.Cache()) == File)
 223    {
 224       Found = StatusFile;
 225       return true;
 226    }
 227
 228    return false;
 229 }
 230                                                                         /*}}}*/