apt-pkg/edsp.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 /* ######################################################################
   4    Set of methods to help writing and reading everything needed for EDSP
   5    ##################################################################### */
   6                                                                         /*}}}*/
   7 // Include Files                                                        /*{{{*/
   8 #include <config.h>
   9
  10 #include <apt-pkg/edsp.h>
  11 #include <apt-pkg/error.h>
  12 #include <apt-pkg/cacheset.h>
  13 #include <apt-pkg/configuration.h>
  14 #include <apt-pkg/version.h>
  15 #include <apt-pkg/policy.h>
  16 #include <apt-pkg/tagfile.h>
  17 #include <apt-pkg/fileutl.h>
  18 #include <apt-pkg/progress.h>
  19
  20 #include <limits>
  21 #include <stdio.h>
  22
  23 #include <string>
  24
  25 #include <apti18n.h>
  26                                                                         /*}}}*/
  27
  28 using std::string;
  29
  30 // we could use pkgCache::DepType and ::Priority, but these would be localized strings…
  31 const char * const EDSP::PrioMap[] = {0, "important", "required", "standard",
  32                                       "optional", "extra"};
  33 const char * const EDSP::DepMap[] = {"", "Depends", "Pre-Depends", "Suggests",
  34                                      "Recommends" , "Conflicts", "Replaces",
  35                                      "Obsoletes", "Breaks", "Enhances"};
  36
  37 // EDSP::WriteScenario - to the given file descriptor                   /*{{{*/
  38 bool EDSP::WriteScenario(pkgDepCache &Cache, FILE* output, OpProgress *Progress)
  39 {
  40    if (Progress != NULL)
  41       Progress->SubProgress(Cache.Head().VersionCount, _("Send scenario to solver"));
  42    unsigned long p = 0;
  43    for (pkgCache::PkgIterator Pkg = Cache.PkgBegin(); Pkg.end() == false; ++Pkg)
  44       for (pkgCache::VerIterator Ver = Pkg.VersionList(); Ver.end() == false; ++Ver, ++p)
  45       {
  46          WriteScenarioVersion(Cache, output, Pkg, Ver);
  47          WriteScenarioDependency(Cache, output, Pkg, Ver);
  48          fprintf(output, "\n");
  49          if (Progress != NULL && p % 100 == 0)
  50             Progress->Progress(p);
  51       }
  52    return true;
  53 }
  54                                                                         /*}}}*/
  55 // EDSP::WriteLimitedScenario - to the given file descriptor            /*{{{*/
  56 bool EDSP::WriteLimitedScenario(pkgDepCache &Cache, FILE* output,
  57                                 APT::PackageSet const &pkgset,
  58                                 OpProgress *Progress)
  59 {
  60    if (Progress != NULL)
  61       Progress->SubProgress(Cache.Head().VersionCount, _("Send scenario to solver"));
  62    unsigned long p  = 0;
  63    for (APT::PackageSet::const_iterator Pkg = pkgset.begin(); Pkg != pkgset.end(); ++Pkg, ++p)
  64       for (pkgCache::VerIterator Ver = Pkg.VersionList(); Ver.end() == false; ++Ver)
  65       {
  66          WriteScenarioVersion(Cache, output, Pkg, Ver);
  67          WriteScenarioLimitedDependency(Cache, output, Pkg, Ver, pkgset);
  68          fprintf(output, "\n");
  69          if (Progress != NULL && p % 100 == 0)
  70             Progress->Progress(p);
  71       }
  72    if (Progress != NULL)
  73       Progress->Done();
  74    return true;
  75 }
  76                                                                         /*}}}*/
  77 // EDSP::WriteScenarioVersion                                           /*{{{*/
  78 void EDSP::WriteScenarioVersion(pkgDepCache &Cache, FILE* output, pkgCache::PkgIterator const &Pkg,
  79                                 pkgCache::VerIterator const &Ver)
  80 {
  81    fprintf(output, "Package: %s\n", Pkg.Name());
  82    fprintf(output, "Architecture: %s\n", Ver.Arch());
  83    fprintf(output, "Version: %s\n", Ver.VerStr());
  84    if (Pkg.CurrentVer() == Ver)
  85       fprintf(output, "Installed: yes\n");
  86    if (Pkg->SelectedState == pkgCache::State::Hold ||
  87        (Cache[Pkg].Keep() == true && Cache[Pkg].Protect() == true))
  88       fprintf(output, "Hold: yes\n");
  89    fprintf(output, "APT-ID: %d\n", Ver->ID);
  90    fprintf(output, "Priority: %s\n", PrioMap[Ver->Priority]);
  91    if ((Pkg->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential)
  92       fprintf(output, "Essential: yes\n");
  93    fprintf(output, "Section: %s\n", Ver.Section());
  94    if ((Ver->MultiArch & pkgCache::Version::Allowed) == pkgCache::Version::Allowed)
  95       fprintf(output, "Multi-Arch: allowed\n");
  96    else if ((Ver->MultiArch & pkgCache::Version::Foreign) == pkgCache::Version::Foreign)
  97       fprintf(output, "Multi-Arch: foreign\n");
  98    else if ((Ver->MultiArch & pkgCache::Version::Same) == pkgCache::Version::Same)
  99       fprintf(output, "Multi-Arch: same\n");
 100    signed short Pin = std::numeric_limits<signed short>::min();
 101    for (pkgCache::VerFileIterator File = Ver.FileList(); File.end() == false; ++File) {
 102       signed short const p = Cache.GetPolicy().GetPriority(File.File());
 103       if (Pin < p)
 104          Pin = p;
 105    }
 106    fprintf(output, "APT-Pin: %d\n", Pin);
 107    if (Cache.GetCandidateVer(Pkg) == Ver)
 108       fprintf(output, "APT-Candidate: yes\n");
 109    if ((Cache[Pkg].Flags & pkgCache::Flag::Auto) == pkgCache::Flag::Auto)
 110       fprintf(output, "APT-Automatic: yes\n");
 111 }
 112                                                                         /*}}}*/
 113 // EDSP::WriteScenarioDependency                                        /*{{{*/
 114 void EDSP::WriteScenarioDependency(pkgDepCache &Cache, FILE* output, pkgCache::PkgIterator const &Pkg,
 115                                 pkgCache::VerIterator const &Ver)
 116 {
 117    std::string dependencies[pkgCache::Dep::Enhances + 1];
 118    bool orGroup = false;
 119    for (pkgCache::DepIterator Dep = Ver.DependsList(); Dep.end() == false; ++Dep)
 120    {
 121       if (Dep.IsMultiArchImplicit() == true)
 122          continue;
 123       if (orGroup == false)
 124          dependencies[Dep->Type].append(", ");
 125       dependencies[Dep->Type].append(Dep.TargetPkg().Name());
 126       if (Dep->Version != 0)
 127          dependencies[Dep->Type].append(" (").append(pkgCache::CompTypeDeb(Dep->CompareOp)).append(" ").append(Dep.TargetVer()).append(")");
 128       if ((Dep->CompareOp & pkgCache::Dep::Or) == pkgCache::Dep::Or)
 129       {
 130          dependencies[Dep->Type].append(" | ");
 131          orGroup = true;
 132       }
 133       else
 134          orGroup = false;
 135    }
 136    for (int i = 1; i < pkgCache::Dep::Enhances + 1; ++i)
 137       if (dependencies[i].empty() == false)
 138          fprintf(output, "%s: %s\n", DepMap[i], dependencies[i].c_str()+2);
 139    string provides;
 140    for (pkgCache::PrvIterator Prv = Ver.ProvidesList(); Prv.end() == false; ++Prv)
 141    {
 142       if (Prv.IsMultiArchImplicit() == true)
 143          continue;
 144       provides.append(", ").append(Prv.Name());
 145    }
 146    if (provides.empty() == false)
 147       fprintf(output, "Provides: %s\n", provides.c_str()+2);
 148 }
 149                                                                         /*}}}*/
 150 // EDSP::WriteScenarioLimitedDependency                                 /*{{{*/
 151 void EDSP::WriteScenarioLimitedDependency(pkgDepCache &Cache, FILE* output,
 152                                           pkgCache::PkgIterator const &Pkg,
 153                                           pkgCache::VerIterator const &Ver,
 154                                           APT::PackageSet const &pkgset)
 155 {
 156    std::string dependencies[pkgCache::Dep::Enhances + 1];
 157    bool orGroup = false;
 158    for (pkgCache::DepIterator Dep = Ver.DependsList(); Dep.end() == false; ++Dep)
 159    {
 160       if (Dep.IsMultiArchImplicit() == true)
 161          continue;
 162       if (orGroup == false)
 163       {
 164          if (pkgset.find(Dep.TargetPkg()) == pkgset.end())
 165             continue;
 166          dependencies[Dep->Type].append(", ");
 167       }
 168       else if (pkgset.find(Dep.TargetPkg()) == pkgset.end())
 169       {
 170          if ((Dep->CompareOp & pkgCache::Dep::Or) == pkgCache::Dep::Or)
 171             continue;
 172          dependencies[Dep->Type].erase(dependencies[Dep->Type].end()-3, dependencies[Dep->Type].end());
 173          orGroup = false;
 174          continue;
 175       }
 176       dependencies[Dep->Type].append(Dep.TargetPkg().Name());
 177       if (Dep->Version != 0)
 178          dependencies[Dep->Type].append(" (").append(pkgCache::CompTypeDeb(Dep->CompareOp)).append(" ").append(Dep.TargetVer()).append(")");
 179       if ((Dep->CompareOp & pkgCache::Dep::Or) == pkgCache::Dep::Or)
 180       {
 181          dependencies[Dep->Type].append(" | ");
 182          orGroup = true;
 183       }
 184       else
 185          orGroup = false;
 186    }
 187    for (int i = 1; i < pkgCache::Dep::Enhances + 1; ++i)
 188       if (dependencies[i].empty() == false)
 189          fprintf(output, "%s: %s\n", DepMap[i], dependencies[i].c_str()+2);
 190    string provides;
 191    for (pkgCache::PrvIterator Prv = Ver.ProvidesList(); Prv.end() == false; ++Prv)
 192    {
 193       if (Prv.IsMultiArchImplicit() == true)
 194          continue;
 195       if (pkgset.find(Prv.ParentPkg()) == pkgset.end())
 196          continue;
 197       provides.append(", ").append(Prv.Name());
 198    }
 199    if (provides.empty() == false)
 200       fprintf(output, "Provides: %s\n", provides.c_str()+2);
 201 }
 202                                                                         /*}}}*/
 203 // EDSP::WriteRequest - to the given file descriptor                    /*{{{*/
 204 bool EDSP::WriteRequest(pkgDepCache &Cache, FILE* output, bool const Upgrade,
 205                         bool const DistUpgrade, bool const AutoRemove,
 206                         OpProgress *Progress)
 207 {
 208    if (Progress != NULL)
 209       Progress->SubProgress(Cache.Head().PackageCount, _("Send request to solver"));
 210    unsigned long p = 0;
 211    string del, inst;
 212    for (pkgCache::PkgIterator Pkg = Cache.PkgBegin(); Pkg.end() == false; ++Pkg, ++p)
 213    {
 214       if (Progress != NULL && p % 100 == 0)
 215          Progress->Progress(p);
 216       string* req;
 217       pkgDepCache::StateCache &P = Cache[Pkg];
 218       if (P.Delete() == true)
 219          req = &del;
 220       else if (P.NewInstall() == true || P.Upgrade() == true || P.ReInstall() == true ||
 221                (P.Mode == pkgDepCache::ModeKeep && (P.iFlags & pkgDepCache::Protected) == pkgDepCache::Protected))
 222          req = &inst;
 223       else
 224          continue;
 225       req->append(" ").append(Pkg.FullName());
 226    }
 227    fprintf(output, "Request: EDSP 0.4\n");
 228    if (del.empty() == false)
 229       fprintf(output, "Remove: %s\n", del.c_str()+1);
 230    if (inst.empty() == false)
 231       fprintf(output, "Install: %s\n", inst.c_str()+1);
 232    if (Upgrade == true)
 233       fprintf(output, "Upgrade: yes\n");
 234    if (DistUpgrade == true)
 235       fprintf(output, "Dist-Upgrade: yes\n");
 236    if (AutoRemove == true)
 237       fprintf(output, "Autoremove: yes\n");
 238    if (_config->FindB("APT::Solver::Strict-Pinning", true) == false)
 239       fprintf(output, "Strict-Pinning: no\n");
 240    string solverpref("APT::Solver::");
 241    solverpref.append(_config->Find("APT::Solver", "internal")).append("::Preferences");
 242    if (_config->Exists(solverpref) == true)
 243       fprintf(output, "Preferences: %s\n", _config->Find(solverpref,"").c_str());
 244    fprintf(output, "\n");
 245
 246    return true;
 247 }
 248                                                                         /*}}}*/
 249 // EDSP::ReadResponse - from the given file descriptor                  /*{{{*/
 250 bool EDSP::ReadResponse(int const input, pkgDepCache &Cache, OpProgress *Progress) {
 251         /* We build an map id to mmap offset here
 252            In theory we could use the offset as ID, but then VersionCount
 253            couldn't be used to create other versionmappings anymore and it
 254            would be too easy for a (buggy) solver to segfault APT… */
 255         unsigned long long const VersionCount = Cache.Head().VersionCount;
 256         unsigned long VerIdx[VersionCount];
 257         for (pkgCache::PkgIterator P = Cache.PkgBegin(); P.end() == false; ++P) {
 258                 for (pkgCache::VerIterator V = P.VersionList(); V.end() == false; ++V)
 259                         VerIdx[V->ID] = V.Index();
 260                 Cache[P].Marked = true;
 261                 Cache[P].Garbage = false;
 262         }
 263
 264         FileFd in;
 265         in.OpenDescriptor(input, FileFd::ReadOnly);
 266         pkgTagFile response(&in, 100);
 267         pkgTagSection section;
 268
 269         while (response.Step(section) == true) {
 270                 std::string type;
 271                 if (section.Exists("Install") == true)
 272                         type = "Install";
 273                 else if (section.Exists("Remove") == true)
 274                         type = "Remove";
 275                 else if (section.Exists("Progress") == true) {
 276                         if (Progress != NULL) {
 277                                 string msg = section.FindS("Message");
 278                                 if (msg.empty() == true)
 279                                         msg = _("Prepare for receiving solution");
 280                                 Progress->SubProgress(100, msg, section.FindI("Percentage", 0));
 281                         }
 282                         continue;
 283                 } else if (section.Exists("Error") == true) {
 284                         std::string msg = SubstVar(SubstVar(section.FindS("Message"), "\n .\n", "\n\n"), "\n ", "\n");
 285                         if (msg.empty() == true) {
 286                                 msg = _("External solver failed without a proper error message");
 287                                 _error->Error("%s", msg.c_str());
 288                         } else
 289                                 _error->Error("External solver failed with: %s", msg.substr(0,msg.find('\n')).c_str());
 290                         if (Progress != NULL)
 291                                 Progress->Done();
 292                         std::cerr << "The solver encountered an error of type: " << section.FindS("Error") << std::endl;
 293                         std::cerr << "The following information might help you to understand what is wrong:" << std::endl;
 294                         std::cerr << msg << std::endl << std::endl;
 295                         return false;
 296                 } else if (section.Exists("Autoremove") == true)
 297                         type = "Autoremove";
 298                 else
 299                         continue;
 300
 301                 size_t const id = section.FindULL(type.c_str(), VersionCount);
 302                 if (id == VersionCount) {
 303                         _error->Warning("Unable to parse %s request with id value '%s'!", type.c_str(), section.FindS(type.c_str()).c_str());
 304                         continue;
 305                 } else if (id > Cache.Head().VersionCount) {
 306                         _error->Warning("ID value '%s' in %s request stanza is to high to refer to a known version!", section.FindS(type.c_str()).c_str(), type.c_str());
 307                         continue;
 308                 }
 309
 310                 pkgCache::VerIterator Ver(Cache.GetCache(), Cache.GetCache().VerP + VerIdx[id]);
 311                 Cache.SetCandidateVersion(Ver);
 312                 if (type == "Install")
 313                         Cache.MarkInstall(Ver.ParentPkg(), false, 0, false);
 314                 else if (type == "Remove")
 315                         Cache.MarkDelete(Ver.ParentPkg(), false);
 316                 else if (type == "Autoremove") {
 317                         Cache[Ver.ParentPkg()].Marked = false;
 318                         Cache[Ver.ParentPkg()].Garbage = true;
 319                 }
 320         }
 321         return true;
 322 }
 323                                                                         /*}}}*/
 324 // EDSP::ReadLine - first line from the given file descriptor           /*{{{*/
 325 // ---------------------------------------------------------------------
 326 /* Little helper method to read a complete line into a string. Similar to
 327    fgets but we need to use the low-level read() here as otherwise the
 328    listparser will be confused later on as mixing of fgets and read isn't
 329    a supported action according to the manpages and results are undefined */
 330 bool EDSP::ReadLine(int const input, std::string &line) {
 331         char one;
 332         ssize_t data = 0;
 333         line.erase();
 334         line.reserve(100);
 335         while ((data = read(input, &one, sizeof(one))) != -1) {
 336                 if (data != 1)
 337                         continue;
 338                 if (one == '\n')
 339                         return true;
 340                 if (one == '\r')
 341                         continue;
 342                 if (line.empty() == true && isblank(one) != 0)
 343                         continue;
 344                 line += one;
 345         }
 346         return false;
 347 }
 348                                                                         /*}}}*/
 349 // EDSP::StringToBool - convert yes/no to bool                          /*{{{*/
 350 // ---------------------------------------------------------------------
 351 /* we are not as lazy as we are in the global StringToBool as we really
 352    only accept yes/no here - but we will ignore leading spaces */
 353 bool EDSP::StringToBool(char const *answer, bool const defValue) {
 354    for (; isspace(*answer) != 0; ++answer);
 355    if (strncasecmp(answer, "yes", 3) == 0)
 356       return true;
 357    else if (strncasecmp(answer, "no", 2) == 0)
 358       return false;
 359    else
 360       _error->Warning("Value '%s' is not a boolean 'yes' or 'no'!", answer);
 361    return defValue;
 362 }
 363                                                                         /*}}}*/
 364 // EDSP::ReadRequest - first stanza from the given file descriptor      /*{{{*/
 365 bool EDSP::ReadRequest(int const input, std::list<std::string> &install,
 366                         std::list<std::string> &remove, bool &upgrade,
 367                         bool &distUpgrade, bool &autoRemove)
 368 {
 369    install.clear();
 370    remove.clear();
 371    upgrade = false;
 372    distUpgrade = false;
 373    autoRemove = false;
 374    std::string line;
 375    while (ReadLine(input, line) == true)
 376    {
 377       // Skip empty lines before request
 378       if (line.empty() == true)
 379          continue;
 380       // The first Tag must be a request, so search for it
 381       if (line.compare(0, 8, "Request:") != 0)
 382          continue;
 383
 384       while (ReadLine(input, line) == true)
 385       {
 386          // empty lines are the end of the request
 387          if (line.empty() == true)
 388             return true;
 389
 390          std::list<std::string> *request = NULL;
 391          if (line.compare(0, 8, "Install:") == 0)
 392          {
 393             line.erase(0, 8);
 394             request = &install;
 395          }
 396          else if (line.compare(0, 7, "Remove:") == 0)
 397          {
 398             line.erase(0, 7);
 399             request = &remove;
 400          }
 401          else if (line.compare(0, 8, "Upgrade:") == 0)
 402             upgrade = EDSP::StringToBool(line.c_str() + 9, false);
 403          else if (line.compare(0, 13, "Dist-Upgrade:") == 0)
 404             distUpgrade = EDSP::StringToBool(line.c_str() + 14, false);
 405          else if (line.compare(0, 11, "Autoremove:") == 0)
 406             autoRemove = EDSP::StringToBool(line.c_str() + 12, false);
 407          else
 408             _error->Warning("Unknown line in EDSP Request stanza: %s", line.c_str());
 409
 410          if (request == NULL)
 411             continue;
 412          size_t end = line.length();
 413          do {
 414             size_t begin = line.rfind(' ');
 415             if (begin == std::string::npos)
 416             {
 417                request->push_back(line.substr(0, end));
 418                break;
 419             }
 420             else if (begin < end)
 421                request->push_back(line.substr(begin + 1, end));
 422             line.erase(begin);
 423             end = line.find_last_not_of(' ');
 424          } while (end != std::string::npos);
 425       }
 426    }
 427    return false;
 428 }
 429                                                                         /*}}}*/
 430 // EDSP::ApplyRequest - first stanza from the given file descriptor     /*{{{*/
 431 bool EDSP::ApplyRequest(std::list<std::string> const &install,
 432                          std::list<std::string> const &remove,
 433                          pkgDepCache &Cache)
 434 {
 435         for (std::list<std::string>::const_iterator i = install.begin();
 436              i != install.end(); ++i) {
 437                 pkgCache::PkgIterator P = Cache.FindPkg(*i);
 438                 if (P.end() == true)
 439                         _error->Warning("Package %s is not known, so can't be installed", i->c_str());
 440                 else
 441                         Cache.MarkInstall(P, false);
 442         }
 443
 444         for (std::list<std::string>::const_iterator i = remove.begin();
 445              i != remove.end(); ++i) {
 446                 pkgCache::PkgIterator P = Cache.FindPkg(*i);
 447                 if (P.end() == true)
 448                         _error->Warning("Package %s is not known, so can't be installed", i->c_str());
 449                 else
 450                         Cache.MarkDelete(P);
 451         }
 452         return true;
 453 }
 454                                                                         /*}}}*/
 455 // EDSP::WriteSolution - to the given file descriptor                   /*{{{*/
 456 bool EDSP::WriteSolution(pkgDepCache &Cache, FILE* output)
 457 {
 458    bool const Debug = _config->FindB("Debug::EDSP::WriteSolution", false);
 459    for (pkgCache::PkgIterator Pkg = Cache.PkgBegin(); Pkg.end() == false; ++Pkg)
 460    {
 461       if (Cache[Pkg].Delete() == true)
 462       {
 463          fprintf(output, "Remove: %d\n", Pkg.CurrentVer()->ID);
 464          if (Debug == true)
 465             fprintf(output, "Package: %s\nVersion: %s\n", Pkg.FullName().c_str(), Pkg.CurrentVer().VerStr());
 466       }
 467       else if (Cache[Pkg].NewInstall() == true || Cache[Pkg].Upgrade() == true)
 468       {
 469          fprintf(output, "Install: %d\n", Cache.GetCandidateVer(Pkg)->ID);
 470          if (Debug == true)
 471             fprintf(output, "Package: %s\nVersion: %s\n", Pkg.FullName().c_str(), Cache.GetCandidateVer(Pkg).VerStr());
 472       }
 473       else if (Cache[Pkg].Garbage == true)
 474       {
 475          fprintf(output, "Autoremove: %d\n", Pkg.CurrentVer()->ID);
 476          if (Debug == true)
 477             fprintf(output, "Package: %s\nVersion: %s\n", Pkg.FullName().c_str(), Pkg.CurrentVer().VerStr());
 478             fprintf(stderr, "Autoremove: %s\nVersion: %s\n", Pkg.FullName().c_str(), Pkg.CurrentVer().VerStr());
 479       }
 480       else
 481          continue;
 482       fprintf(output, "\n");
 483    }
 484
 485    return true;
 486 }
 487                                                                         /*}}}*/
 488 // EDSP::WriteProgess - pulse to the given file descriptor              /*{{{*/
 489 bool EDSP::WriteProgress(unsigned short const percent, const char* const message, FILE* output) {
 490         fprintf(output, "Progress: %s\n", TimeRFC1123(time(NULL)).c_str());
 491         fprintf(output, "Percentage: %d\n", percent);
 492         fprintf(output, "Message: %s\n\n", message);
 493         fflush(output);
 494         return true;
 495 }
 496                                                                         /*}}}*/
 497 // EDSP::WriteError - format an error message to be send to file descriptor /*{{{*/
 498 bool EDSP::WriteError(char const * const uuid, std::string const &message, FILE* output) {
 499         fprintf(output, "Error: %s\n", uuid);
 500         fprintf(output, "Message: %s\n\n", SubstVar(SubstVar(message, "\n\n", "\n.\n"), "\n", "\n ").c_str());
 501         return true;
 502 }
 503                                                                         /*}}}*/
 504 // EDSP::ExecuteSolver - fork requested solver and setup ipc pipes      {{{*/
 505 bool EDSP::ExecuteSolver(const char* const solver, int *solver_in, int *solver_out) {
 506         std::vector<std::string> const solverDirs = _config->FindVector("Dir::Bin::Solvers");
 507         std::string file;
 508         for (std::vector<std::string>::const_iterator dir = solverDirs.begin();
 509              dir != solverDirs.end(); ++dir) {
 510                 file = flCombine(*dir, solver);
 511                 if (RealFileExists(file.c_str()) == true)
 512                         break;
 513                 file.clear();
 514         }
 515
 516         if (file.empty() == true)
 517                 return _error->Error("Can't call external solver '%s' as it is not in a configured directory!", solver);
 518         int external[4] = {-1, -1, -1, -1};
 519         if (pipe(external) != 0 || pipe(external + 2) != 0)
 520                 return _error->Errno("Resolve", "Can't create needed IPC pipes for EDSP");
 521         for (int i = 0; i < 4; ++i)
 522                 SetCloseExec(external[i], true);
 523
 524         pid_t Solver = ExecFork();
 525         if (Solver == 0) {
 526                 dup2(external[0], STDIN_FILENO);
 527                 dup2(external[3], STDOUT_FILENO);
 528                 const char* calling[2] = { file.c_str(), 0 };
 529                 execv(calling[0], (char**) calling);
 530                 std::cerr << "Failed to execute solver '" << solver << "'!" << std::endl;
 531                 _exit(100);
 532         }
 533         close(external[0]);
 534         close(external[3]);
 535
 536         if (WaitFd(external[1], true, 5) == false)
 537                 return _error->Errno("Resolve", "Timed out while Waiting on availability of solver stdin");
 538
 539         *solver_in = external[1];
 540         *solver_out = external[2];
 541         return true;
 542 }
 543                                                                         /*}}}*/
 544 // EDSP::ResolveExternal - resolve problems by asking external for help {{{*/
 545 bool EDSP::ResolveExternal(const char* const solver, pkgDepCache &Cache,
 546                          bool const upgrade, bool const distUpgrade,
 547                          bool const autoRemove, OpProgress *Progress) {
 548         int solver_in, solver_out;
 549         if (EDSP::ExecuteSolver(solver, &solver_in, &solver_out) == false)
 550                 return false;
 551
 552         FILE* output = fdopen(solver_in, "w");
 553         if (output == NULL)
 554                 return _error->Errno("Resolve", "fdopen on solver stdin failed");
 555
 556         if (Progress != NULL)
 557                 Progress->OverallProgress(0, 100, 5, _("Execute external solver"));
 558         EDSP::WriteRequest(Cache, output, upgrade, distUpgrade, autoRemove, Progress);
 559         if (Progress != NULL)
 560                 Progress->OverallProgress(5, 100, 20, _("Execute external solver"));
 561         EDSP::WriteScenario(Cache, output, Progress);
 562         fclose(output);
 563
 564         if (Progress != NULL)
 565                 Progress->OverallProgress(25, 100, 75, _("Execute external solver"));
 566         if (EDSP::ReadResponse(solver_out, Cache, Progress) == false)
 567                 return false;
 568
 569         return true;
 570 }
 571                                                                         /*}}}*/