apt-pkg/deb/debsystem.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: debsystem.cc,v 1.2 2001/02/20 07:03:17 jgg 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
  41    Label = "Debian dpkg interface";
  42    VS = &debVS;
  43 }
  44                                                                         /*}}}*/
  45 // System::Lock - Get the lock                                          /*{{{*/
  46 // ---------------------------------------------------------------------
  47 /* This mirrors the operations dpkg does when it starts up. Note the
  48    checking of the updates directory. */
  49 bool debSystem::Lock()
  50 {
  51    // Disable file locking
  52    if (_config->FindB("Debug::NoLocking",false) == true || LockCount > 1)
  53    {
  54       LockCount++;
  55       return true;
  56    }
  57
  58    // Create the lockfile
  59    string AdminDir = flNotFile(_config->Find("Dir::State::status"));
  60    LockFD = GetLock(AdminDir + "lock");
  61    if (LockFD == -1)
  62    {
  63       if (errno == EACCES || errno == EAGAIN)
  64          return _error->Error("Unable to lock the administration directory (%s), "
  65                               "is another process using it?",AdminDir.c_str());
  66       else
  67          return _error->Error("Unable to lock the administration directory (%s), "
  68                               "are you root?",AdminDir.c_str());
  69    }
  70
  71    // See if we need to abort with a dirty journal
  72    if (CheckUpdates() == true)
  73    {
  74       close(LockFD);
  75       LockFD = -1;
  76       return _error->Error("dpkg was interrupted, you must manually "
  77                            "run 'dpkg --configure -a' to correct the problem. ");
  78    }
  79
  80          LockCount++;
  81
  82    return true;
  83 }
  84                                                                         /*}}}*/
  85 // System::UnLock - Drop a lock                                         /*{{{*/
  86 // ---------------------------------------------------------------------
  87 /* */
  88 bool debSystem::UnLock(bool NoErrors)
  89 {
  90    if (LockCount == 0 && NoErrors == true)
  91       return false;
  92
  93    if (LockCount < 1)
  94       return _error->Error("Not locked");
  95    if (--LockCount == 0)
  96    {
  97       close(LockFD);
  98       LockCount = 0;
  99    }
 100
 101    return true;
 102 }
 103                                                                         /*}}}*/
 104 // System::CheckUpdates - Check if the updates dir is dirty             /*{{{*/
 105 // ---------------------------------------------------------------------
 106 /* This does a check of the updates directory (dpkg journal) to see if it has
 107    any entries in it. */
 108 bool debSystem::CheckUpdates()
 109 {
 110    // Check for updates.. (dirty)
 111    string File = flNotFile(_config->Find("Dir::State::status")) + "updates/";
 112    DIR *DirP = opendir(File.c_str());
 113    if (DirP == 0)
 114       return false;
 115
 116    /* We ignore any files that are not all digits, this skips .,.. and
 117       some tmp files dpkg will leave behind.. */
 118    bool Damaged = false;
 119    for (struct dirent *Ent = readdir(DirP); Ent != 0; Ent = readdir(DirP))
 120    {
 121       Damaged = true;
 122       for (unsigned int I = 0; Ent->d_name[I] != 0; I++)
 123       {
 124          // Check if its not a digit..
 125          if (isdigit(Ent->d_name[I]) == 0)
 126          {
 127             Damaged = false;
 128             break;
 129          }
 130       }
 131       if (Damaged == true)
 132          break;
 133    }
 134    closedir(DirP);
 135
 136    return Damaged;
 137 }
 138                                                                         /*}}}*/
 139 // System::CreatePM - Create the underlying package manager             /*{{{*/
 140 // ---------------------------------------------------------------------
 141 /* */
 142 pkgPackageManager *debSystem::CreatePM(pkgDepCache *Cache) const
 143 {
 144    return new pkgDPkgPM(Cache);
 145 }
 146                                                                         /*}}}*/
 147 // System::Initialize - Setup the configuration space..                 /*{{{*/
 148 // ---------------------------------------------------------------------
 149 /* These are the Debian specific configuration variables.. */
 150 bool debSystem::Initialize(Configuration &Cnf)
 151 {
 152    /* These really should be jammed into a generic 'Local Database' engine
 153       which is yet to be determined. The functions in pkgcachegen should
 154       be the only users of these */
 155    Cnf.CndSet("Dir::State::userstatus","status.user"); // Defunct
 156    Cnf.CndSet("Dir::State::status","/var/lib/dpkg/status");
 157    Cnf.CndSet("Dir::Bin::dpkg","/usr/bin/dpkg");
 158
 159    return true;
 160 }
 161                                                                         /*}}}*/
 162 // System::ArchiveSupported - Is a file format supported                /*{{{*/
 163 // ---------------------------------------------------------------------
 164 /* The standard name for a deb is 'deb'.. There are no seperate versions
 165    of .deb to worry about.. */
 166 bool debSystem::ArchiveSupported(const char *Type)
 167 {
 168    if (strcmp(Type,"deb") == 0)
 169       return true;
 170    return false;
 171 }
 172                                                                         /*}}}*/
 173 // System::Score - Determine how 'Debiany' this sys is..                /*{{{*/
 174 // ---------------------------------------------------------------------
 175 /* We check some files that are sure tell signs of this being a Debian
 176    System.. */
 177 signed debSystem::Score(Configuration const &Cnf)
 178 {
 179    signed Score = 0;
 180    if (FileExists(Cnf.FindFile("Dir::State::status","/var/lib/dpkg/status")) == true)
 181        Score += 10;
 182    if (FileExists(Cnf.FindFile("Dir::Bin::dpkg","/usr/bin/dpkg")) == true)
 183       Score += 10;
 184    if (FileExists("/etc/debian_version") == true)
 185       Score += 10;
 186    return Score;
 187 }
 188                                                                         /*}}}*/
 189 // System::AddStatusFiles - Register the status files                   /*{{{*/
 190 // ---------------------------------------------------------------------
 191 /* */
 192 bool debSystem::AddStatusFiles(vector<pkgIndexFile *> &List)
 193 {
 194    List.push_back(new debStatusIndex(_config->FindFile("Dir::State::status")));
 195    return true;
 196 }
 197                                                                         /*}}}*/