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 #include <apti18n.h>
  21
  22 #include <sys/types.h>
  23 #include <unistd.h>
  24 #include <dirent.h>
  25 #include <errno.h>
  26                                                                         /*}}}*/
  27
  28 debSystem debSys;
  29
  30 // System::debSystem - Constructor                                      /*{{{*/
  31 // ---------------------------------------------------------------------
  32 /* */
  33 debSystem::debSystem()
  34 {
  35    LockFD = -1;
  36    LockCount = 0;
  37    StatusFile = 0;
  38
  39    Label = "Debian dpkg interface";
  40    VS = &debVS;
  41 }
  42                                                                         /*}}}*/
  43 // System::~debSystem - Destructor                                      /*{{{*/
  44 // ---------------------------------------------------------------------
  45 /* */
  46 debSystem::~debSystem()
  47 {
  48    delete StatusFile;
  49 }
  50                                                                         /*}}}*/
  51 // System::Lock - Get the lock                                          /*{{{*/
  52 // ---------------------------------------------------------------------
  53 /* This mirrors the operations dpkg does when it starts up. Note the
  54    checking of the updates directory. */
  55 bool debSystem::Lock()
  56 {
  57    // Disable file locking
  58    if (_config->FindB("Debug::NoLocking",false) == true || LockCount > 1)
  59    {
  60       LockCount++;
  61       return true;
  62    }
  63
  64    // Create the lockfile
  65    string AdminDir = flNotFile(_config->Find("Dir::State::status"));
  66    LockFD = GetLock(AdminDir + "lock");
  67    if (LockFD == -1)
  68    {
  69       if (errno == EACCES || errno == EAGAIN)
  70          return _error->Error("Unable to lock the administration directory (%s), "
  71                               "is another process using it?",AdminDir.c_str());
  72       else
  73          return _error->Error("Unable to lock the administration directory (%s), "
  74                               "are you root?",AdminDir.c_str());
  75    }
  76
  77    // See if we need to abort with a dirty journal
  78    if (CheckUpdates() == true)
  79    {
  80       close(LockFD);
  81       LockFD = -1;
  82       return _error->Error("dpkg was interrupted, you must manually "
  83                            "run 'dpkg --configure -a' to correct the problem. ");
  84    }
  85
  86          LockCount++;
  87
  88    return true;
  89 }
  90                                                                         /*}}}*/
  91 // System::UnLock - Drop a lock                                         /*{{{*/
  92 // ---------------------------------------------------------------------
  93 /* */
  94 bool debSystem::UnLock(bool NoErrors)
  95 {
  96    if (LockCount == 0 && NoErrors == true)
  97       return false;
  98
  99    if (LockCount < 1)
 100       return _error->Error(_("Not locked"));
 101    if (--LockCount == 0)
 102    {
 103       close(LockFD);
 104       LockCount = 0;
 105    }
 106
 107    return true;
 108 }
 109                                                                         /*}}}*/
 110 // System::CheckUpdates - Check if the updates dir is dirty             /*{{{*/
 111 // ---------------------------------------------------------------------
 112 /* This does a check of the updates directory (dpkg journal) to see if it has
 113    any entries in it. */
 114 bool debSystem::CheckUpdates()
 115 {
 116    // Check for updates.. (dirty)
 117    string File = flNotFile(_config->Find("Dir::State::status")) + "updates/";
 118    DIR *DirP = opendir(File.c_str());
 119    if (DirP == 0)
 120       return false;
 121
 122    /* We ignore any files that are not all digits, this skips .,.. and
 123       some tmp files dpkg will leave behind.. */
 124    bool Damaged = false;
 125    for (struct dirent *Ent = readdir(DirP); Ent != 0; Ent = readdir(DirP))
 126    {
 127       Damaged = true;
 128       for (unsigned int I = 0; Ent->d_name[I] != 0; I++)
 129       {
 130          // Check if its not a digit..
 131          if (isdigit(Ent->d_name[I]) == 0)
 132          {
 133             Damaged = false;
 134             break;
 135          }
 136       }
 137       if (Damaged == true)
 138          break;
 139    }
 140    closedir(DirP);
 141
 142    return Damaged;
 143 }
 144                                                                         /*}}}*/
 145 // System::CreatePM - Create the underlying package manager             /*{{{*/
 146 // ---------------------------------------------------------------------
 147 /* */
 148 pkgPackageManager *debSystem::CreatePM(pkgDepCache *Cache) const
 149 {
 150    return new pkgDPkgPM(Cache);
 151 }
 152                                                                         /*}}}*/
 153 // System::Initialize - Setup the configuration space..                 /*{{{*/
 154 // ---------------------------------------------------------------------
 155 /* These are the Debian specific configuration variables.. */
 156 bool debSystem::Initialize(Configuration &Cnf)
 157 {
 158    /* These really should be jammed into a generic 'Local Database' engine
 159       which is yet to be determined. The functions in pkgcachegen should
 160       be the only users of these */
 161    Cnf.CndSet("Dir::State::userstatus","status.user"); // Defunct
 162    Cnf.CndSet("Dir::State::status","/var/lib/dpkg/status");
 163    Cnf.CndSet("Dir::Bin::dpkg","/usr/bin/dpkg");
 164
 165    if (StatusFile) {
 166      delete StatusFile;
 167      StatusFile = 0;
 168    }
 169
 170    return true;
 171 }
 172                                                                         /*}}}*/
 173 // System::ArchiveSupported - Is a file format supported                /*{{{*/
 174 // ---------------------------------------------------------------------
 175 /* The standard name for a deb is 'deb'.. There are no seperate versions
 176    of .deb to worry about.. */
 177 bool debSystem::ArchiveSupported(const char *Type)
 178 {
 179    if (strcmp(Type,"deb") == 0)
 180       return true;
 181    return false;
 182 }
 183                                                                         /*}}}*/
 184 // System::Score - Determine how 'Debiany' this sys is..                /*{{{*/
 185 // ---------------------------------------------------------------------
 186 /* We check some files that are sure tell signs of this being a Debian
 187    System.. */
 188 signed debSystem::Score(Configuration const &Cnf)
 189 {
 190    signed Score = 0;
 191    if (FileExists(Cnf.FindFile("Dir::State::status","/var/lib/dpkg/status")) == true)
 192        Score += 10;
 193    if (FileExists(Cnf.FindFile("Dir::Bin::dpkg","/usr/bin/dpkg")) == true)
 194       Score += 10;
 195    if (FileExists("/etc/debian_version") == true)
 196       Score += 10;
 197    return Score;
 198 }
 199                                                                         /*}}}*/
 200 // System::AddStatusFiles - Register the status files                   /*{{{*/
 201 // ---------------------------------------------------------------------
 202 /* */
 203 bool debSystem::AddStatusFiles(vector<pkgIndexFile *> &List)
 204 {
 205    if (StatusFile == 0)
 206       StatusFile = new debStatusIndex(_config->FindFile("Dir::State::status"));
 207    List.push_back(StatusFile);
 208    return true;
 209 }
 210                                                                         /*}}}*/
 211 // System::FindIndex - Get an index file for status files               /*{{{*/
 212 // ---------------------------------------------------------------------
 213 /* */
 214 bool debSystem::FindIndex(pkgCache::PkgFileIterator File,
 215                           pkgIndexFile *&Found) const
 216 {
 217    if (StatusFile == 0)
 218       return false;
 219    if (StatusFile->FindInCache(*File.Cache()) == File)
 220    {
 221       Found = StatusFile;
 222       return true;
 223    }
 224
 225    return false;
 226 }
 227                                                                         /*}}}*/