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