apt-pkg/policy.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: policy.cc,v 1.10 2003/08/12 00:17:37 mdz Exp $
   4 /* ######################################################################
   5
   6    Package Version Policy implementation
   7
   8    This is just a really simple wrapper around pkgVersionMatch with
   9    some added goodies to manage the list of things..
  10
  11    See man apt_preferences for what value means what.
  12
  13    ##################################################################### */
  14                                                                         /*}}}*/
  15 // Include Files                                                        /*{{{*/
  16 #include<config.h>
  17
  18 #include <apt-pkg/policy.h>
  19 #include <apt-pkg/configuration.h>
  20 #include <apt-pkg/cachefilter.h>
  21 #include <apt-pkg/tagfile.h>
  22 #include <apt-pkg/strutl.h>
  23 #include <apt-pkg/fileutl.h>
  24 #include <apt-pkg/error.h>
  25 #include <apt-pkg/cacheiterators.h>
  26 #include <apt-pkg/pkgcache.h>
  27 #include <apt-pkg/versionmatch.h>
  28 #include <apt-pkg/version.h>
  29
  30 #include <ctype.h>
  31 #include <stddef.h>
  32 #include <string.h>
  33 #include <string>
  34 #include <vector>
  35 #include <iostream>
  36 #include <sstream>
  37
  38 #include <apti18n.h>
  39                                                                         /*}}}*/
  40
  41 using namespace std;
  42
  43 // Policy::Init - Startup and bind to a cache                           /*{{{*/
  44 // ---------------------------------------------------------------------
  45 /* Set the defaults for operation. The default mode with no loaded policy
  46    file matches the V0 policy engine. */
  47 pkgPolicy::pkgPolicy(pkgCache *Owner) : Pins(nullptr), VerPins(nullptr),
  48    PFPriority(nullptr), Cache(Owner), d(NULL)
  49 {
  50    if (Owner == 0)
  51       return;
  52    PFPriority = new signed short[Owner->Head().PackageFileCount];
  53    Pins = new Pin[Owner->Head().PackageCount];
  54    VerPins = new Pin[Owner->Head().VersionCount];
  55
  56    for (unsigned long I = 0; I != Owner->Head().PackageCount; I++)
  57       Pins[I].Type = pkgVersionMatch::None;
  58    for (unsigned long I = 0; I != Owner->Head().VersionCount; I++)
  59       VerPins[I].Type = pkgVersionMatch::None;
  60
  61    // The config file has a master override.
  62    string DefRel = _config->Find("APT::Default-Release");
  63    if (DefRel.empty() == false)
  64    {
  65       bool found = false;
  66       // FIXME: make ExpressionMatches static to use it here easily
  67       pkgVersionMatch vm("", pkgVersionMatch::None);
  68       for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); ++F)
  69       {
  70          if (vm.ExpressionMatches(DefRel, F.Archive()) ||
  71              vm.ExpressionMatches(DefRel, F.Codename()) ||
  72              vm.ExpressionMatches(DefRel, F.Version()) ||
  73              (DefRel.length() > 2 && DefRel[1] == '='))
  74             found = true;
  75       }
  76       if (found == false)
  77          _error->Error(_("The value '%s' is invalid for APT::Default-Release as such a release is not available in the sources"), DefRel.c_str());
  78       else
  79          CreatePin(pkgVersionMatch::Release,"",DefRel,990);
  80    }
  81    InitDefaults();
  82 }
  83                                                                         /*}}}*/
  84 // Policy::InitDefaults - Compute the default selections                /*{{{*/
  85 // ---------------------------------------------------------------------
  86 /* */
  87 bool pkgPolicy::InitDefaults()
  88 {
  89    // Initialize the priorities based on the status of the package file
  90    for (pkgCache::PkgFileIterator I = Cache->FileBegin(); I != Cache->FileEnd(); ++I)
  91    {
  92       PFPriority[I->ID] = 500;
  93       if (I.Flagged(pkgCache::Flag::NotSource))
  94          PFPriority[I->ID] = 100;
  95       else if (I.Flagged(pkgCache::Flag::ButAutomaticUpgrades))
  96          PFPriority[I->ID] = 100;
  97       else if (I.Flagged(pkgCache::Flag::NotAutomatic))
  98          PFPriority[I->ID] = 1;
  99    }
 100
 101    // Apply the defaults..
 102    std::unique_ptr<bool[]> Fixed(new bool[Cache->HeaderP->PackageFileCount]);
 103    memset(Fixed.get(),0,sizeof(Fixed[0])*Cache->HeaderP->PackageFileCount);
 104    StatusOverride = false;
 105    for (vector<Pin>::const_iterator I = Defaults.begin(); I != Defaults.end(); ++I)
 106    {
 107       pkgVersionMatch Match(I->Data,I->Type);
 108       for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); ++F)
 109       {
 110          if (Fixed[F->ID] == false && Match.FileMatch(F) == true)
 111          {
 112             PFPriority[F->ID] = I->Priority;
 113
 114             if (PFPriority[F->ID] >= 1000)
 115                StatusOverride = true;
 116
 117             Fixed[F->ID] = true;
 118          }
 119       }
 120    }
 121
 122    if (_config->FindB("Debug::pkgPolicy",false) == true)
 123       for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); ++F)
 124          std::clog << "Prio of " << F.FileName() << ' ' << PFPriority[F->ID] << std::endl;
 125
 126    return true;
 127 }
 128                                                                         /*}}}*/
 129 // Policy::GetCandidateVer - Get the candidate install version          /*{{{*/
 130 // ---------------------------------------------------------------------
 131 /* Evaluate the package pins and the default list to deteremine what the
 132    best package is. */
 133 pkgCache::VerIterator pkgPolicy::GetCandidateVer(pkgCache::PkgIterator const &Pkg)
 134 {
 135    pkgCache::VerIterator cand;
 136    pkgCache::VerIterator cur = Pkg.CurrentVer();
 137    int candPriority = -1;
 138    pkgVersioningSystem *vs = Cache->VS;
 139
 140    for (pkgCache::VerIterator ver = Pkg.VersionList(); ver.end() == false; ++ver) {
 141       int priority = GetPriority(ver, true);
 142
 143       if (priority == 0 || priority <= candPriority)
 144          continue;
 145
 146       // TODO: Maybe optimize to not compare versions
 147       if (!cur.end() && priority < 1000
 148           && (vs->CmpVersion(ver.VerStr(), cur.VerStr()) < 0))
 149          continue;
 150
 151       candPriority = priority;
 152       cand = ver;
 153    }
 154
 155    return cand;
 156 }
 157                                                                         /*}}}*/
 158 // Policy::CreatePin - Create an entry in the pin table..               /*{{{*/
 159 // ---------------------------------------------------------------------
 160 /* For performance we have 3 tables, the default table, the main cache
 161    table (hashed to the cache). A blank package name indicates the pin
 162    belongs to the default table. Order of insertion matters here, the
 163    earlier defaults override later ones. */
 164 void pkgPolicy::CreatePin(pkgVersionMatch::MatchType Type,string Name,
 165                           string Data,signed short Priority)
 166 {
 167    if (Name.empty() == true)
 168    {
 169       Pin *P = &*Defaults.insert(Defaults.end(),Pin());
 170       P->Type = Type;
 171       P->Priority = Priority;
 172       P->Data = Data;
 173       return;
 174    }
 175
 176    size_t found = Name.rfind(':');
 177    string Arch;
 178    if (found != string::npos) {
 179       Arch = Name.substr(found+1);
 180       Name.erase(found);
 181    }
 182
 183    // Allow pinning by wildcards
 184    // TODO: Maybe we should always prefer specific pins over non-
 185    // specific ones.
 186    if (Name[0] == '/' || Name.find_first_of("*[?") != string::npos)
 187    {
 188       pkgVersionMatch match(Data, Type);
 189       for (pkgCache::GrpIterator G = Cache->GrpBegin(); G.end() != true; ++G)
 190          if (match.ExpressionMatches(Name, G.Name()))
 191          {
 192             if (Arch.empty() == false)
 193                CreatePin(Type, string(G.Name()).append(":").append(Arch), Data, Priority);
 194             else
 195                CreatePin(Type, G.Name(), Data, Priority);
 196          }
 197       return;
 198    }
 199
 200    // find the package (group) this pin applies to
 201    pkgCache::GrpIterator Grp = Cache->FindGrp(Name);
 202    bool matched = false;
 203    if (Grp.end() == false)
 204    {
 205       std::string MatchingArch;
 206       if (Arch.empty() == true)
 207          MatchingArch = Cache->NativeArch();
 208       else
 209          MatchingArch = Arch;
 210       APT::CacheFilter::PackageArchitectureMatchesSpecification pams(MatchingArch);
 211       for (pkgCache::PkgIterator Pkg = Grp.PackageList(); Pkg.end() != true; Pkg = Grp.NextPkg(Pkg))
 212       {
 213          if (pams(Pkg.Arch()) == false)
 214             continue;
 215          Pin *P = Pins + Pkg->ID;
 216          // the first specific stanza for a package is the ruler,
 217          // all others need to be ignored
 218          if (P->Type != pkgVersionMatch::None)
 219             P = &*Unmatched.insert(Unmatched.end(),PkgPin(Pkg.FullName()));
 220          P->Type = Type;
 221          P->Priority = Priority;
 222          P->Data = Data;
 223          matched = true;
 224
 225          // Find matching version(s) and copy the pin into it
 226          pkgVersionMatch Match(P->Data,P->Type);
 227          for (pkgCache::VerIterator Ver = Pkg.VersionList(); Ver.end() != true; ++Ver)
 228          {
 229             if (Match.VersionMatches(Ver)) {
 230                Pin *VP = VerPins + Ver->ID;
 231                if (VP->Type == pkgVersionMatch::None)
 232                   *VP = *P;
 233             }
 234          }
 235       }
 236    }
 237
 238    if (matched == false)
 239    {
 240       PkgPin *P = &*Unmatched.insert(Unmatched.end(),PkgPin(Name));
 241       if (Arch.empty() == false)
 242          P->Pkg.append(":").append(Arch);
 243       P->Type = Type;
 244       P->Priority = Priority;
 245       P->Data = Data;
 246       return;
 247    }
 248 }
 249                                                                         /*}}}*/
 250 // Policy::GetMatch - Get the matching version for a package pin        /*{{{*/
 251 // ---------------------------------------------------------------------
 252 /* */
 253 pkgCache::VerIterator pkgPolicy::GetMatch(pkgCache::PkgIterator const &Pkg)
 254 {
 255    const Pin &PPkg = Pins[Pkg->ID];
 256    if (PPkg.Type == pkgVersionMatch::None)
 257       return pkgCache::VerIterator(*Pkg.Cache());
 258
 259    pkgVersionMatch Match(PPkg.Data,PPkg.Type);
 260    return Match.Find(Pkg);
 261 }
 262                                                                         /*}}}*/
 263 // Policy::GetPriority - Get the priority of the package pin            /*{{{*/
 264 // ---------------------------------------------------------------------
 265 /* */
 266 APT_PURE signed short pkgPolicy::GetPriority(pkgCache::PkgIterator const &Pkg)
 267 {
 268    if (Pins[Pkg->ID].Type != pkgVersionMatch::None)
 269       return Pins[Pkg->ID].Priority;
 270    return 0;
 271 }
 272 APT_PURE signed short pkgPolicy::GetPriority(pkgCache::VerIterator const &Ver, bool ConsiderFiles)
 273 {
 274    if (VerPins[Ver->ID].Type != pkgVersionMatch::None)
 275       return VerPins[Ver->ID].Priority;
 276    if (!ConsiderFiles)
 277       return 0;
 278
 279    // priorities are short ints, but we want to pick a value outside the valid range here
 280    auto priority = std::numeric_limits<signed int>::min();
 281    for (pkgCache::VerFileIterator file = Ver.FileList(); file.end() == false; file++)
 282    {
 283       /* If this is the status file, and the current version is not the
 284          version in the status file (ie it is not installed, or somesuch)
 285          then it is not a candidate for installation, ever. This weeds
 286          out bogus entries that may be due to config-file states, or
 287          other. */
 288       if (file.File().Flagged(pkgCache::Flag::NotSource) && Ver.ParentPkg().CurrentVer() != Ver)
 289          priority = std::max(priority, static_cast<decltype(priority)>(-1));
 290       else
 291          priority = std::max(priority, static_cast<decltype(priority)>(GetPriority(file.File())));
 292    }
 293
 294    return priority == std::numeric_limits<decltype(priority)>::min() ? 0 : priority;
 295 }
 296 APT_PURE signed short pkgPolicy::GetPriority(pkgCache::PkgFileIterator const &File)
 297 {
 298    return PFPriority[File->ID];
 299 }
 300                                                                         /*}}}*/
 301 // ReadPinDir - Load the pin files from this dir into a Policy          /*{{{*/
 302 // ---------------------------------------------------------------------
 303 /* This will load each pin file in the given dir into a Policy. If the
 304    given dir is empty the dir set in Dir::Etc::PreferencesParts is used.
 305    Note also that this method will issue a warning if the dir does not
 306    exists but it will return true in this case! */
 307 bool ReadPinDir(pkgPolicy &Plcy,string Dir)
 308 {
 309    if (Dir.empty() == true)
 310       Dir = _config->FindDir("Dir::Etc::PreferencesParts");
 311
 312    if (DirectoryExists(Dir) == false)
 313    {
 314       if (Dir != "/dev/null")
 315          _error->WarningE("DirectoryExists",_("Unable to read %s"),Dir.c_str());
 316       return true;
 317    }
 318
 319    vector<string> const List = GetListOfFilesInDir(Dir, "pref", true, true);
 320
 321    // Read the files
 322    for (vector<string>::const_iterator I = List.begin(); I != List.end(); ++I)
 323       if (ReadPinFile(Plcy, *I) == false)
 324          return false;
 325    return true;
 326 }
 327                                                                         /*}}}*/
 328 // ReadPinFile - Load the pin file into a Policy                        /*{{{*/
 329 // ---------------------------------------------------------------------
 330 /* I'd like to see the preferences file store more than just pin information
 331    but right now that is the only stuff I have to store. Later there will
 332    have to be some kind of combined super parser to get the data into all
 333    the right classes.. */
 334 bool ReadPinFile(pkgPolicy &Plcy,string File)
 335 {
 336    if (File.empty() == true)
 337       File = _config->FindFile("Dir::Etc::Preferences");
 338
 339    if (RealFileExists(File) == false)
 340       return true;
 341
 342    FileFd Fd(File,FileFd::ReadOnly);
 343    pkgTagFile TF(&Fd, pkgTagFile::SUPPORT_COMMENTS);
 344    if (Fd.IsOpen() == false || Fd.Failed())
 345       return false;
 346
 347    pkgTagSection Tags;
 348    while (TF.Step(Tags) == true)
 349    {
 350       // can happen when there are only comments in a record
 351       if (Tags.Count() == 0)
 352          continue;
 353
 354       string Name = Tags.FindS("Package");
 355       if (Name.empty() == true)
 356          return _error->Error(_("Invalid record in the preferences file %s, no Package header"), File.c_str());
 357       if (Name == "*")
 358          Name = string();
 359
 360       const char *Start;
 361       const char *End;
 362       if (Tags.Find("Pin",Start,End) == false)
 363          continue;
 364
 365       const char *Word = Start;
 366       for (; Word != End && isspace(*Word) == 0; Word++);
 367
 368       // Parse the type..
 369       pkgVersionMatch::MatchType Type;
 370       if (stringcasecmp(Start,Word,"version") == 0 && Name.empty() == false)
 371          Type = pkgVersionMatch::Version;
 372       else if (stringcasecmp(Start,Word,"release") == 0)
 373          Type = pkgVersionMatch::Release;
 374       else if (stringcasecmp(Start,Word,"origin") == 0)
 375          Type = pkgVersionMatch::Origin;
 376       else
 377       {
 378          _error->Warning(_("Did not understand pin type %s"),string(Start,Word).c_str());
 379          continue;
 380       }
 381       for (; Word != End && isspace(*Word) != 0; Word++);
 382
 383       _error->PushToStack();
 384       int const priority = Tags.FindI("Pin-Priority", 0);
 385       bool const newError = _error->PendingError();
 386       _error->MergeWithStack();
 387       if (priority < std::numeric_limits<short>::min() ||
 388           priority > std::numeric_limits<short>::max() ||
 389           newError) {
 390          return _error->Error(_("%s: Value %s is outside the range of valid pin priorities (%d to %d)"),
 391                               File.c_str(), Tags.FindS("Pin-Priority").c_str(),
 392                               std::numeric_limits<short>::min(),
 393                               std::numeric_limits<short>::max());
 394       }
 395       if (priority == 0)
 396       {
 397          return _error->Error(_("No priority (or zero) specified for pin"));
 398       }
 399
 400       istringstream s(Name);
 401       string pkg;
 402       while(!s.eof())
 403       {
 404          s >> pkg;
 405          Plcy.CreatePin(Type, pkg, string(Word,End),priority);
 406       };
 407    }
 408
 409    Plcy.InitDefaults();
 410    return true;
 411 }
 412                                                                         /*}}}*/
 413
 414 pkgPolicy::~pkgPolicy() {delete [] PFPriority; delete [] Pins; delete [] VerPins; }