Attempt to skip and resync any seriously broken semantics in package sections.

[apt-legacy.git] / apt-pkg / deb / dpkgpm.cc

// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
// $Id: dpkgpm.cc,v 1.28 2004/01/27 02:25:01 mdz Exp $
/* ######################################################################

   DPKG Package Manager - Provide an interface to dpkg
   
   ##################################################################### */
									/*}}}*/
// Includes								/*{{{*/
#include <apt-pkg/dpkgpm.h>
#include <apt-pkg/error.h>
#include <apt-pkg/configuration.h>
#include <apt-pkg/depcache.h>
#include <apt-pkg/strutl.h>
#include <apti18n.h>
#include <apt-pkg/fileutl.h>

#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/select.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <sstream>
#include <map>

#include <termios.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <util.h>

#include <config.h>
#include <apti18n.h>
									/*}}}*/

using namespace std;

namespace
{
  // Maps the dpkg "processing" info to human readable names.  Entry 0
  // of each array is the key, entry 1 is the value.
  const std::pair<const char *, const char *> PackageProcessingOps[] = {
    std::make_pair("install",   N_("Installing %s")),
    std::make_pair("configure", N_("Configuring %s")),
    std::make_pair("remove",    N_("Removing %s")),
    std::make_pair("purge",    N_("Completely removing %s")),
    std::make_pair("trigproc",  N_("Running post-installation trigger %s"))
  };

  const std::pair<const char *, const char *> * const PackageProcessingOpsBegin = PackageProcessingOps;
  const std::pair<const char *, const char *> * const PackageProcessingOpsEnd   = PackageProcessingOps + sizeof(PackageProcessingOps) / sizeof(PackageProcessingOps[0]);

  // Predicate to test whether an entry in the PackageProcessingOps
  // array matches a string.
  class MatchProcessingOp
  {
    const char *target;

  public:
    MatchProcessingOp(const char *the_target)
      : target(the_target)
    {
    }

    bool operator()(const std::pair<const char *, const char *> &pair) const
    {
      return strcmp(pair.first, target) == 0;
    }
  };
}

/* helper function to ionice the given PID 

 there is no C header for ionice yet - just the syscall interface
 so we use the binary from util-linux
*/
static bool
ionice(int PID)
{
   if (!FileExists("/usr/bin/ionice"))
      return false;
   pid_t Process = ExecFork();      
   if (Process == 0)
   {
      char buf[32];
      snprintf(buf, sizeof(buf), "-p%d", PID);
      const char *Args[4];
      Args[0] = "/usr/bin/ionice";
      Args[1] = "-c3";
      Args[2] = buf;
      Args[3] = 0;
      execv(Args[0], (char **)Args);
   }
   return ExecWait(Process, "ionice");
}

// DPkgPM::pkgDPkgPM - Constructor					/*{{{*/
// ---------------------------------------------------------------------
/* */
pkgDPkgPM::pkgDPkgPM(pkgDepCache *Cache) 
   : pkgPackageManager(Cache), dpkgbuf_pos(0),
     term_out(NULL), PackagesDone(0), PackagesTotal(0)
{
}
									/*}}}*/
// DPkgPM::pkgDPkgPM - Destructor					/*{{{*/
// ---------------------------------------------------------------------
/* */
pkgDPkgPM::~pkgDPkgPM()
{
}
									/*}}}*/
// DPkgPM::Install - Install a package					/*{{{*/
// ---------------------------------------------------------------------
/* Add an install operation to the sequence list */
bool pkgDPkgPM::Install(PkgIterator Pkg,string File)
{
   if (File.empty() == true || Pkg.end() == true)
      return _error->Error("Internal Error, No file name for %s",Pkg.Name());

   List.push_back(Item(Item::Install,Pkg,File));
   return true;
}
									/*}}}*/
// DPkgPM::Configure - Configure a package				/*{{{*/
// ---------------------------------------------------------------------
/* Add a configure operation to the sequence list */
bool pkgDPkgPM::Configure(PkgIterator Pkg)
{
   if (Pkg.end() == true)
      return false;

   List.push_back(Item(Item::Configure, Pkg));

   // Use triggers for config calls if we configure "smart"
   // as otherwise Pre-Depends will not be satisfied, see #526774
   if (_config->FindB("DPkg::TriggersPending", false) == true)
      List.push_back(Item(Item::TriggersPending, PkgIterator()));

   return true;
}
									/*}}}*/
// DPkgPM::Remove - Remove a package					/*{{{*/
// ---------------------------------------------------------------------
/* Add a remove operation to the sequence list */
bool pkgDPkgPM::Remove(PkgIterator Pkg,bool Purge)
{
   if (Pkg.end() == true)
      return false;
   
   if (Purge == true)
      List.push_back(Item(Item::Purge,Pkg));
   else
      List.push_back(Item(Item::Remove,Pkg));
   return true;
}
									/*}}}*/
// DPkgPM::SendV2Pkgs - Send version 2 package info			/*{{{*/
// ---------------------------------------------------------------------
/* This is part of the helper script communication interface, it sends
   very complete information down to the other end of the pipe.*/
bool pkgDPkgPM::SendV2Pkgs(FILE *F)
{
   fprintf(F,"VERSION 2\n");
   
   /* Write out all of the configuration directives by walking the 
      configuration tree */
   const Configuration::Item *Top = _config->Tree(0);
   for (; Top != 0;)
   {
      if (Top->Value.empty() == false)
      {
	 fprintf(F,"%s=%s\n",
		 QuoteString(Top->FullTag(),"=\"\n").c_str(),
		 QuoteString(Top->Value,"\n").c_str());
      }

      if (Top->Child != 0)
      {
	 Top = Top->Child;
	 continue;
      }
      
      while (Top != 0 && Top->Next == 0)
	 Top = Top->Parent;
      if (Top != 0)
	 Top = Top->Next;
   }   
   fprintf(F,"\n");
 
   // Write out the package actions in order.
   for (vector<Item>::iterator I = List.begin(); I != List.end(); I++)
   {
      if(I->Pkg.end() == true)
	 continue;

      pkgDepCache::StateCache &S = Cache[I->Pkg];
      
      fprintf(F,"%s ",I->Pkg.Name());
      // Current version
      if (I->Pkg->CurrentVer == 0)
	 fprintf(F,"- ");
      else
	 fprintf(F,"%s ",I->Pkg.CurrentVer().VerStr());
      
      // Show the compare operator
      // Target version
      if (S.InstallVer != 0)
      {
	 int Comp = 2;
	 if (I->Pkg->CurrentVer != 0)
	    Comp = S.InstVerIter(Cache).CompareVer(I->Pkg.CurrentVer());
	 if (Comp < 0)
	    fprintf(F,"> ");
	 if (Comp == 0)
	    fprintf(F,"= ");
	 if (Comp > 0)
	    fprintf(F,"< ");
	 fprintf(F,"%s ",S.InstVerIter(Cache).VerStr());
      }
      else
	 fprintf(F,"> - ");
      
      // Show the filename/operation
      if (I->Op == Item::Install)
      {
	 // No errors here..
	 if (I->File[0] != '/')
	    fprintf(F,"**ERROR**\n");
	 else
	    fprintf(F,"%s\n",I->File.c_str());
      }      
      if (I->Op == Item::Configure)
	 fprintf(F,"**CONFIGURE**\n");
      if (I->Op == Item::Remove ||
	  I->Op == Item::Purge)
	 fprintf(F,"**REMOVE**\n");
      
      if (ferror(F) != 0)
	 return false;
   }
   return true;
}
									/*}}}*/
// DPkgPM::RunScriptsWithPkgs - Run scripts with package names on stdin /*{{{*/
// ---------------------------------------------------------------------
/* This looks for a list of scripts to run from the configuration file
   each one is run and is fed on standard input a list of all .deb files
   that are due to be installed. */
bool pkgDPkgPM::RunScriptsWithPkgs(const char *Cnf)
{
   Configuration::Item const *Opts = _config->Tree(Cnf);
   if (Opts == 0 || Opts->Child == 0)
      return true;
   Opts = Opts->Child;
   
   unsigned int Count = 1;
   for (; Opts != 0; Opts = Opts->Next, Count++)
   {
      if (Opts->Value.empty() == true)
         continue;

      // Determine the protocol version
      string OptSec = Opts->Value;
      string::size_type Pos;
      if ((Pos = OptSec.find(' ')) == string::npos || Pos == 0)
	 Pos = OptSec.length();
      OptSec = "DPkg::Tools::Options::" + string(Opts->Value.c_str(),Pos);
      
      unsigned int Version = _config->FindI(OptSec+"::Version",1);
      
      // Create the pipes
      int Pipes[2];
      if (pipe(Pipes) != 0)
	 return _error->Errno("pipe","Failed to create IPC pipe to subprocess");
      SetCloseExec(Pipes[0],true);
      SetCloseExec(Pipes[1],true);
      
      // Purified Fork for running the script
      pid_t Process = ExecFork();      
      if (Process == 0)
      {
	 // Setup the FDs
	 dup2(Pipes[0],STDIN_FILENO);
	 SetCloseExec(STDOUT_FILENO,false);
	 SetCloseExec(STDIN_FILENO,false);      
	 SetCloseExec(STDERR_FILENO,false);

	 const char *Args[4];
	 Args[0] = "/bin/sh";
	 Args[1] = "-c";
	 Args[2] = Opts->Value.c_str();
	 Args[3] = 0;
	 execv(Args[0],(char **)Args);
	 _exit(100);
      }
      close(Pipes[0]);
      FILE *F = fdopen(Pipes[1],"w");
      if (F == 0)
	 return _error->Errno("fdopen","Faild to open new FD");
      
      // Feed it the filenames.
      bool Die = false;
      if (Version <= 1)
      {
	 for (vector<Item>::iterator I = List.begin(); I != List.end(); I++)
	 {
	    // Only deal with packages to be installed from .deb
	    if (I->Op != Item::Install)
	       continue;

	    // No errors here..
	    if (I->File[0] != '/')
	       continue;
	    
	    /* Feed the filename of each package that is pending install
	       into the pipe. */
	    fprintf(F,"%s\n",I->File.c_str());
	    if (ferror(F) != 0)
	    {
	       Die = true;
	       break;
	    }
	 }
      }
      else
	 Die = !SendV2Pkgs(F);

      fclose(F);
      
      // Clean up the sub process
      if (ExecWait(Process,Opts->Value.c_str()) == false)
	 return _error->Error("Failure running script %s",Opts->Value.c_str());
   }

   return true;
}

									/*}}}*/
// DPkgPM::DoStdin - Read stdin and pass to slave pty			/*{{{*/
// ---------------------------------------------------------------------
/*
*/
void pkgDPkgPM::DoStdin(int master)
{
   unsigned char input_buf[256] = {0,}; 
   ssize_t len = read(0, input_buf, sizeof(input_buf));
   if (len)
      write(master, input_buf, len);
   else
      stdin_is_dev_null = true;
}
									/*}}}*/
// DPkgPM::DoTerminalPty - Read the terminal pty and write log		/*{{{*/
// ---------------------------------------------------------------------
/*
 * read the terminal pty and write log
 */
void pkgDPkgPM::DoTerminalPty(int master)
{
   unsigned char term_buf[1024] = {0,0, };

   ssize_t len=read(master, term_buf, sizeof(term_buf));
   if(len == -1 && errno == EIO)
   {
      // this happens when the child is about to exit, we
      // give it time to actually exit, otherwise we run
      // into a race
      usleep(500000);
      return;
   }  
   if(len <= 0) 
      return;
   write(1, term_buf, len);
   if(term_out)
      fwrite(term_buf, len, sizeof(char), term_out);
}
									/*}}}*/
// DPkgPM::ProcessDpkgStatusBuf                                        	/*{{{*/
// ---------------------------------------------------------------------
/*
 */
void pkgDPkgPM::ProcessDpkgStatusLine(int OutStatusFd, char *line)
{
   bool const Debug = _config->FindB("Debug::pkgDPkgProgressReporting",false);
   // the status we output
   ostringstream status;

   if (Debug == true)
      std::clog << "got from dpkg '" << line << "'" << std::endl;


   /* dpkg sends strings like this:
      'status:   <pkg>:  <pkg  qstate>'
      errors look like this:
      'status: /var/cache/apt/archives/krecipes_0.8.1-0ubuntu1_i386.deb : error : trying to overwrite `/usr/share/doc/kde/HTML/en/krecipes/krectip.png', which is also in package krecipes-data 
      and conffile-prompt like this
      'status: conffile-prompt: conffile : 'current-conffile' 'new-conffile' useredited distedited
      
      Newer versions of dpkg sent also:
      'processing: install: pkg'
      'processing: configure: pkg'
      'processing: remove: pkg'
      'processing: purge: pkg' - but for apt is it a ignored "unknown" action
      'processing: trigproc: trigger'
	    
   */
   char* list[5];
   //        dpkg sends multiline error messages sometimes (see
   //        #374195 for a example. we should support this by
   //        either patching dpkg to not send multiline over the
   //        statusfd or by rewriting the code here to deal with
   //        it. for now we just ignore it and not crash
   TokSplitString(':', line, list, sizeof(list)/sizeof(list[0]));
   if( list[0] == NULL || list[1] == NULL || list[2] == NULL) 
   {
      if (Debug == true)
	 std::clog << "ignoring line: not enough ':'" << std::endl;
      return;
   }
   const char* const pkg = list[1];
   const char* action = _strstrip(list[2]);

   // 'processing' from dpkg looks like
   // 'processing: action: pkg'
   if(strncmp(list[0], "processing", strlen("processing")) == 0)
   {
      char s[200];
      const char* const pkg_or_trigger = _strstrip(list[2]);
      action = _strstrip( list[1]);
      const std::pair<const char *, const char *> * const iter =
	std::find_if(PackageProcessingOpsBegin,
		     PackageProcessingOpsEnd,
		     MatchProcessingOp(action));
      if(iter == PackageProcessingOpsEnd)
      {
	 if (Debug == true)
	    std::clog << "ignoring unknown action: " << action << std::endl;
	 return;
      }
      snprintf(s, sizeof(s), _(iter->second), pkg_or_trigger);

      status << "pmstatus:" << pkg_or_trigger
	     << ":"  << (PackagesDone/float(PackagesTotal)*100.0) 
	     << ":" << s
	     << endl;
      if(OutStatusFd > 0)
	 write(OutStatusFd, status.str().c_str(), status.str().size());
      if (Debug == true)
	 std::clog << "send: '" << status.str() << "'" << endl;
      return;
   }

   if(strncmp(action,"error",strlen("error")) == 0)
   {
      status << "pmerror:" << list[1]
	     << ":"  << (PackagesDone/float(PackagesTotal)*100.0) 
	     << ":" << list[3]
	     << endl;
      if(OutStatusFd > 0)
	 write(OutStatusFd, status.str().c_str(), status.str().size());
      if (Debug == true)
	 std::clog << "send: '" << status.str() << "'" << endl;
      return;
   }
   else if(strncmp(action,"conffile",strlen("conffile")) == 0)
   {
      status << "pmconffile:" << list[1]
	     << ":"  << (PackagesDone/float(PackagesTotal)*100.0) 
	     << ":" << list[3]
	     << endl;
      if(OutStatusFd > 0)
	 write(OutStatusFd, status.str().c_str(), status.str().size());
      if (Debug == true)
	 std::clog << "send: '" << status.str() << "'" << endl;
      return;
   }

   vector<struct DpkgState> const &states = PackageOps[pkg];
   const char *next_action = NULL;
   if(PackageOpsDone[pkg] < states.size())
      next_action = states[PackageOpsDone[pkg]].state;
   // check if the package moved to the next dpkg state
   if(next_action && (strcmp(action, next_action) == 0)) 
   {
      // only read the translation if there is actually a next
      // action
      const char *translation = _(states[PackageOpsDone[pkg]].str);
      char s[200];
      snprintf(s, sizeof(s), translation, pkg);

      // we moved from one dpkg state to a new one, report that
      PackageOpsDone[pkg]++;
      PackagesDone++;
      // build the status str
      status << "pmstatus:" << pkg 
	     << ":"  << (PackagesDone/float(PackagesTotal)*100.0) 
	     << ":" << s
	     << endl;
      if(OutStatusFd > 0)
	 write(OutStatusFd, status.str().c_str(), status.str().size());
      if (Debug == true)
	 std::clog << "send: '" << status.str() << "'" << endl;
   }
   if (Debug == true) 
      std::clog << "(parsed from dpkg) pkg: " << pkg 
		<< " action: " << action << endl;
}
									/*}}}*/
// DPkgPM::DoDpkgStatusFd						/*{{{*/
// ---------------------------------------------------------------------
/*
 */
void pkgDPkgPM::DoDpkgStatusFd(int statusfd, int OutStatusFd)
{
   char *p, *q;
   int len;

   len=read(statusfd, &dpkgbuf[dpkgbuf_pos], sizeof(dpkgbuf)-dpkgbuf_pos);
   dpkgbuf_pos += len;
   if(len <= 0)
      return;

   // process line by line if we have a buffer
   p = q = dpkgbuf;
   while((q=(char*)memchr(p, '\n', dpkgbuf+dpkgbuf_pos-p)) != NULL)
   {
      *q = 0;
      ProcessDpkgStatusLine(OutStatusFd, p);
      p=q+1; // continue with next line
   }

   // now move the unprocessed bits (after the final \n that is now a 0x0) 
   // to the start and update dpkgbuf_pos
   void *memrchr(void const *, int, size_t);
   p = (char*)memrchr(dpkgbuf, 0, dpkgbuf_pos);
   if(p == NULL)
      return;

   // we are interessted in the first char *after* 0x0
   p++;

   // move the unprocessed tail to the start and update pos
   memmove(dpkgbuf, p, p-dpkgbuf);
   dpkgbuf_pos = dpkgbuf+dpkgbuf_pos-p;
}
									/*}}}*/
// DPkgPM::OpenLog							/*{{{*/
bool pkgDPkgPM::OpenLog()
{
   string logdir = _config->FindDir("Dir::Log");
   if(not FileExists(logdir))
      return _error->Error(_("Directory '%s' missing"), logdir.c_str());
   string logfile_name = flCombine(logdir,
				   _config->Find("Dir::Log::Terminal"));
   if (!logfile_name.empty())
   {
      term_out = fopen(logfile_name.c_str(),"a");
      if (term_out == NULL)
	 return _error->WarningE(_("Could not open file '%s'"), logfile_name.c_str());

      chmod(logfile_name.c_str(), 0600);
      // output current time
      char outstr[200];
      time_t t = time(NULL);
      struct tm *tmp = localtime(&t);
      strftime(outstr, sizeof(outstr), "%F  %T", tmp);
      fprintf(term_out, "\nLog started: %s\n", outstr);
   }
   return true;
}
									/*}}}*/
// DPkg::CloseLog							/*{{{*/
bool pkgDPkgPM::CloseLog()
{
   if(term_out)
   {
      char outstr[200];
      time_t t = time(NULL);
      struct tm *tmp = localtime(&t);
      strftime(outstr, sizeof(outstr), "%F  %T", tmp);
      fprintf(term_out, "Log ended: ");
      fprintf(term_out, "%s", outstr);
      fprintf(term_out, "\n");
      fclose(term_out);
   }
   term_out = NULL;
   return true;
}
									/*}}}*/
/*{{{*/
// This implements a racy version of pselect for those architectures
// that don't have a working implementation.
// FIXME: Probably can be removed on Lenny+1
static int racy_pselect(int nfds, fd_set *readfds, fd_set *writefds,
   fd_set *exceptfds, const struct timespec *timeout,
   const sigset_t *sigmask)
{
   sigset_t origmask;
   struct timeval tv;
   int retval;

   tv.tv_sec = timeout->tv_sec;
   tv.tv_usec = timeout->tv_nsec/1000;

   sigprocmask(SIG_SETMASK, sigmask, &origmask);
   retval = select(nfds, readfds, writefds, exceptfds, &tv);
   sigprocmask(SIG_SETMASK, &origmask, 0);
   return retval;
}
/*}}}*/
// DPkgPM::Go - Run the sequence					/*{{{*/
// ---------------------------------------------------------------------
/* This globs the operations and calls dpkg 
 *   
 * If it is called with "OutStatusFd" set to a valid file descriptor
 * apt will report the install progress over this fd. It maps the
 * dpkg states a package goes through to human readable (and i10n-able)
 * names and calculates a percentage for each step.
*/
bool pkgDPkgPM::Go(int OutStatusFd)
{
   fd_set rfds;
   struct timespec tv;
   sigset_t sigmask;
   sigset_t original_sigmask;

   unsigned int const MaxArgs = _config->FindI("Dpkg::MaxArgs",8*1024);
   unsigned int const MaxArgBytes = _config->FindI("Dpkg::MaxArgBytes",32*1024);
   bool const NoTriggers = _config->FindB("DPkg::NoTriggers", false);

   if (RunScripts("DPkg::Pre-Invoke") == false)
      return false;

   if (RunScriptsWithPkgs("DPkg::Pre-Install-Pkgs") == false)
      return false;

   // support subpressing of triggers processing for special
   // cases like d-i that runs the triggers handling manually
   bool const SmartConf = (_config->Find("PackageManager::Configure", "all") != "all");
   bool const TriggersPending = _config->FindB("DPkg::TriggersPending", false);
   if (_config->FindB("DPkg::ConfigurePending", SmartConf) == true)
      List.push_back(Item(Item::ConfigurePending, PkgIterator()));

   // map the dpkg states to the operations that are performed
   // (this is sorted in the same way as Item::Ops)
   static const struct DpkgState DpkgStatesOpMap[][7] = {
      // Install operation
      { 
	 {"half-installed", N_("Preparing %s")}, 
	 {"unpacked", N_("Unpacking %s") }, 
	 {NULL, NULL}
      },
      // Configure operation
      { 
	 {"unpacked",N_("Preparing to configure %s") },
	 {"half-configured", N_("Configuring %s") },
	 { "installed", N_("Installed %s")},
	 {NULL, NULL}
      },
      // Remove operation
      { 
	 {"half-configured", N_("Preparing for removal of %s")},
	 {"half-installed", N_("Removing %s")},
	 {"config-files",  N_("Removed %s")},
	 {NULL, NULL}
      },
      // Purge operation
      { 
	 {"config-files", N_("Preparing to completely remove %s")},
	 {"not-installed", N_("Completely removed %s")},
	 {NULL, NULL}
      },
   };

   // init the PackageOps map, go over the list of packages that
   // that will be [installed|configured|removed|purged] and add
   // them to the PackageOps map (the dpkg states it goes through)
   // and the PackageOpsTranslations (human readable strings)
   for (vector<Item>::const_iterator I = List.begin(); I != List.end();I++)
   {
      if((*I).Pkg.end() == true)
	 continue;

      string const name = (*I).Pkg.Name();
      PackageOpsDone[name] = 0;
      for(int i=0; (DpkgStatesOpMap[(*I).Op][i]).state != NULL;  i++) 
      {
	 PackageOps[name].push_back(DpkgStatesOpMap[(*I).Op][i]);
	 PackagesTotal++;
      }
   }

   stdin_is_dev_null = false;

   // create log
   OpenLog();

   // this loop is runs once per operation
   for (vector<Item>::const_iterator I = List.begin(); I != List.end();)
   {
      // Do all actions with the same Op in one run
      vector<Item>::const_iterator J = I;
      if (TriggersPending == true)
	 for (; J != List.end(); J++)
	 {
	    if (J->Op == I->Op)
	       continue;
	    if (J->Op != Item::TriggersPending)
	       break;
	    vector<Item>::const_iterator T = J + 1;
	    if (T != List.end() && T->Op == I->Op)
	       continue;
	    break;
	 }
      else
	 for (; J != List.end() && J->Op == I->Op; J++)
	    /* nothing */;

      // Generate the argument list
      const char *Args[MaxArgs + 50];
      
      // Now check if we are within the MaxArgs limit
      //
      // this code below is problematic, because it may happen that
      // the argument list is split in a way that A depends on B
      // and they are in the same "--configure A B" run
      // - with the split they may now be configured in different
      //   runs 
      if (J - I > (signed)MaxArgs)
	 J = I + MaxArgs;
      
      unsigned int n = 0;
      unsigned long Size = 0;
      string const Tmp = _config->Find("Dir::Bin::dpkg","dpkg");
      Args[n++] = Tmp.c_str();
      Size += strlen(Args[n-1]);
      
      // Stick in any custom dpkg options
      Configuration::Item const *Opts = _config->Tree("DPkg::Options");
      if (Opts != 0)
      {
	 Opts = Opts->Child;
	 for (; Opts != 0; Opts = Opts->Next)
	 {
	    if (Opts->Value.empty() == true)
	       continue;
	    Args[n++] = Opts->Value.c_str();
	    Size += Opts->Value.length();
	 }	 
      }
      
      char status_fd_buf[20];
      int fd[2];
      pipe(fd);
      
      Args[n++] = "--status-fd";
      Size += strlen(Args[n-1]);
      snprintf(status_fd_buf,sizeof(status_fd_buf),"%i", fd[1]);
      Args[n++] = status_fd_buf;
      Size += strlen(Args[n-1]);

      switch (I->Op)
      {
	 case Item::Remove:
	 Args[n++] = "--force-depends";
	 Size += strlen(Args[n-1]);
	 Args[n++] = "--force-remove-reinstreq";
	 Size += strlen(Args[n-1]);
	 Args[n++] = "--force-remove-essential";
	 Size += strlen(Args[n-1]);
	 Args[n++] = "--remove";
	 Size += strlen(Args[n-1]);
	 break;
	 
	 case Item::Purge:
	 Args[n++] = "--force-depends";
	 Size += strlen(Args[n-1]);
	 Args[n++] = "--force-remove-reinstreq";
	 Size += strlen(Args[n-1]);
	 Args[n++] = "--force-remove-essential";
	 Size += strlen(Args[n-1]);
	 Args[n++] = "--purge";
	 Size += strlen(Args[n-1]);
	 break;
	 
	 case Item::Configure:
	 Args[n++] = "--configure";
	 Size += strlen(Args[n-1]);
	 break;

	 case Item::ConfigurePending:
	 Args[n++] = "--configure";
	 Size += strlen(Args[n-1]);
	 Args[n++] = "--pending";
	 Size += strlen(Args[n-1]);
	 break;

	 case Item::TriggersPending:
	 Args[n++] = "--triggers-only";
	 Size += strlen(Args[n-1]);
	 Args[n++] = "--pending";
	 Size += strlen(Args[n-1]);
	 break;

	 case Item::Install:
	 Args[n++] = "--unpack";
	 Size += strlen(Args[n-1]);
	 Args[n++] = "--auto-deconfigure";
	 Size += strlen(Args[n-1]);
	 break;
      }

      if (NoTriggers == true && I->Op != Item::TriggersPending &&
	  I->Op != Item::ConfigurePending)
      {
	 Args[n++] = "--no-triggers";
	 Size += strlen(Args[n-1]);
      }

      // Write in the file or package names
      if (I->Op == Item::Install)
      {
	 for (;I != J && Size < MaxArgBytes; I++)
	 {
	    if (I->File[0] != '/')
	       return _error->Error("Internal Error, Pathname to install is not absolute '%s'",I->File.c_str());
	    Args[n++] = I->File.c_str();
	    Size += strlen(Args[n-1]);
	 }
      }      
      else
      {
	 for (;I != J && Size < MaxArgBytes; I++)
	 {
	    if((*I).Pkg.end() == true)
	       continue;
	    Args[n++] = I->Pkg.Name();
	    Size += strlen(Args[n-1]);
	 }	 
      }      
      Args[n] = 0;
      J = I;
      
      if (_config->FindB("Debug::pkgDPkgPM",false) == true)
      {
	 for (unsigned int k = 0; k != n; k++)
	    clog << Args[k] << ' ';
	 clog << endl;
	 continue;
      }
      
      cout << flush;
      clog << flush;
      cerr << flush;

      typedef void (*sighandler_t)(int);

      /* Mask off sig int/quit. We do this because dpkg also does when 
         it forks scripts. What happens is that when you hit ctrl-c it sends
	 it to all processes in the group. Since dpkg ignores the signal 
	 it doesn't die but we do! So we must also ignore it */
      sighandler_t old_SIGQUIT = signal(SIGQUIT,SIG_IGN);
      sighandler_t old_SIGINT = signal(SIGINT,SIG_IGN);

      // ignore SIGHUP as well (debian #463030)
      sighandler_t old_SIGHUP = signal(SIGHUP,SIG_IGN);

      struct	termios tt;
      struct	winsize win;
      int	master = -1;
      int	slave = -1;

      // if tcgetattr does not return zero there was a error
      // and we do not do any pty magic
      if (tcgetattr(0, &tt) == 0)
      {
	 ioctl(0, TIOCGWINSZ, (char *)&win);
	 if (openpty(&master, &slave, NULL, &tt, &win) < 0) 
	 {
	    const char *s = _("Can not write log, openpty() "
	                      "failed (/dev/pts not mounted?)\n");
	    fprintf(stderr, "%s",s);
            if(term_out)
              fprintf(term_out, "%s",s);
	    master = slave = -1;
	 }  else {
	    struct termios rtt;
	    rtt = tt;
	    cfmakeraw(&rtt);
	    rtt.c_lflag &= ~ECHO;
	    // block SIGTTOU during tcsetattr to prevent a hang if
	    // the process is a member of the background process group
	    // http://www.opengroup.org/onlinepubs/000095399/functions/tcsetattr.html
	    sigemptyset(&sigmask);
	    sigaddset(&sigmask, SIGTTOU);
	    sigprocmask(SIG_BLOCK,&sigmask, &original_sigmask);
	    tcsetattr(0, TCSAFLUSH, &rtt);
	    sigprocmask(SIG_SETMASK, &original_sigmask, 0);
	 }
      }

       // Fork dpkg
      pid_t Child;
      _config->Set("APT::Keep-Fds::",fd[1]);
      // send status information that we are about to fork dpkg
      if(OutStatusFd > 0) {
	 ostringstream status;
	 status << "pmstatus:dpkg-exec:" 
		<< (PackagesDone/float(PackagesTotal)*100.0) 
		<< ":" << _("Running dpkg")
		<< endl;
	 write(OutStatusFd, status.str().c_str(), status.str().size());
      }
      Child = ExecFork();
            
      // This is the child
      if (Child == 0)
      {
	 if(slave >= 0 && master >= 0) 
	 {
	    setsid();
	    ioctl(slave, TIOCSCTTY, 0);
	    close(master);
	    dup2(slave, 0);
	    dup2(slave, 1);
	    dup2(slave, 2);
	    close(slave);
	 }
	 close(fd[0]); // close the read end of the pipe

	 if (_config->FindDir("DPkg::Chroot-Directory","/") != "/") 
	 {
	    std::cerr << "Chrooting into " 
		      << _config->FindDir("DPkg::Chroot-Directory") 
		      << std::endl;
	    if (chroot(_config->FindDir("DPkg::Chroot-Directory","/").c_str()) != 0)
	       _exit(100);
	 }

	 if (chdir(_config->FindDir("DPkg::Run-Directory","/").c_str()) != 0)
	    _exit(100);
	 
	 if (_config->FindB("DPkg::FlushSTDIN",true) == true && isatty(STDIN_FILENO))
	 {
	    int Flags,dummy;
	    if ((Flags = fcntl(STDIN_FILENO,F_GETFL,dummy)) < 0)
	       _exit(100);
	    
	    // Discard everything in stdin before forking dpkg
	    if (fcntl(STDIN_FILENO,F_SETFL,Flags | O_NONBLOCK) < 0)
	       _exit(100);
	    
	    while (read(STDIN_FILENO,&dummy,1) == 1);
	    
	    if (fcntl(STDIN_FILENO,F_SETFL,Flags & (~(long)O_NONBLOCK)) < 0)
	       _exit(100);
	 }

	 /* No Job Control Stop Env is a magic dpkg var that prevents it
	    from using sigstop */
	 putenv((char *)"DPKG_NO_TSTP=yes");
	 execvp(Args[0],(char **)Args);
	 cerr << "Could not exec dpkg!" << endl;
	 _exit(100);
      }      

      // apply ionice
      if (_config->FindB("DPkg::UseIoNice", false) == true)
	 ionice(Child);

      // clear the Keep-Fd again
      _config->Clear("APT::Keep-Fds",fd[1]);

      // Wait for dpkg
      int Status = 0;

      // we read from dpkg here
      int const _dpkgin = fd[0];
      close(fd[1]);                        // close the write end of the pipe

      if(slave > 0)
	 close(slave);

      // setups fds
      sigemptyset(&sigmask);
      sigprocmask(SIG_BLOCK,&sigmask,&original_sigmask);

      // the result of the waitpid call
      int res;
      int select_ret;
      while ((res=waitpid(Child,&Status, WNOHANG)) != Child) {
	 if(res < 0) {
	    // FIXME: move this to a function or something, looks ugly here
	    // error handling, waitpid returned -1
	    if (errno == EINTR)
	       continue;
	    RunScripts("DPkg::Post-Invoke");

	    // Restore sig int/quit
	    signal(SIGQUIT,old_SIGQUIT);
	    signal(SIGINT,old_SIGINT);
	    signal(SIGHUP,old_SIGHUP);
	    return _error->Errno("waitpid","Couldn't wait for subprocess");
	 }

	 // wait for input or output here
	 FD_ZERO(&rfds);
	 if (!stdin_is_dev_null)
	    FD_SET(0, &rfds); 
	 FD_SET(_dpkgin, &rfds);
	 if(master >= 0)
	    FD_SET(master, &rfds);
	 tv.tv_sec = 1;
	 tv.tv_nsec = 0;
	 select_ret = pselect(max(master, _dpkgin)+1, &rfds, NULL, NULL, 
			      &tv, &original_sigmask);
	 if (select_ret < 0 && (errno == EINVAL || errno == ENOSYS))
	    select_ret = racy_pselect(max(master, _dpkgin)+1, &rfds, NULL,
				      NULL, &tv, &original_sigmask);
	 if (select_ret == 0) 
  	    continue;
  	 else if (select_ret < 0 && errno == EINTR)
  	    continue;
  	 else if (select_ret < 0) 
 	 {
  	    perror("select() returned error");
  	    continue;
  	 } 
	 
	 if(master >= 0 && FD_ISSET(master, &rfds))
	    DoTerminalPty(master);
	 if(master >= 0 && FD_ISSET(0, &rfds))
	    DoStdin(master);
	 if(FD_ISSET(_dpkgin, &rfds))
	    DoDpkgStatusFd(_dpkgin, OutStatusFd);
      }
      close(_dpkgin);

      // Restore sig int/quit
      signal(SIGQUIT,old_SIGQUIT);
      signal(SIGINT,old_SIGINT);
      signal(SIGHUP,old_SIGHUP);

      if(master >= 0) 
      {
	 tcsetattr(0, TCSAFLUSH, &tt);
	 close(master);
      }
       
      // Check for an error code.
      if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
      {
	 // if it was set to "keep-dpkg-runing" then we won't return
	 // here but keep the loop going and just report it as a error
	 // for later
	 bool const stopOnError = _config->FindB("Dpkg::StopOnError",true);
	 
	 if(stopOnError)
	    RunScripts("DPkg::Post-Invoke");

	 if (WIFSIGNALED(Status) != 0 && WTERMSIG(Status) == SIGSEGV) 
	    _error->Error("Sub-process %s received a segmentation fault.",Args[0]);
	 else if (WIFEXITED(Status) != 0)
	    _error->Error("Sub-process %s returned an error code (%u)",Args[0],WEXITSTATUS(Status));
	 else 
	    _error->Error("Sub-process %s exited unexpectedly",Args[0]);

	 if(stopOnError) 
	 {
	    CloseLog();
	    return false;
	 }
      }      
   }
   CloseLog();

   if (RunScripts("DPkg::Post-Invoke") == false)
      return false;

   Cache.writeStateFile(NULL);
   return true;
}
									/*}}}*/
// pkgDpkgPM::Reset - Dump the contents of the command list		/*{{{*/
// ---------------------------------------------------------------------
/* */
void pkgDPkgPM::Reset() 
{
   List.erase(List.begin(),List.end());
}
									/*}}}*/

/* memrchr -- find the last occurrence of a byte in a memory block

   Copyright (C) 1991, 1993, 1996, 1997, 1999, 2000, 2003, 2004, 2005,
   2006, 2007, 2008 Free Software Foundation, Inc.

   Based on strlen implementation by Torbjorn Granlund (tege@sics.se),
   with help from Dan Sahlin (dan@sics.se) and
   commentary by Jim Blandy (jimb@ai.mit.edu);
   adaptation to memchr suggested by Dick Karpinski (dick@cca.ucsf.edu),
   and implemented by Roland McGrath (roland@ai.mit.edu).

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#if defined _LIBC
# include <memcopy.h>
#else
# include <config.h>
# define reg_char char
#endif

#include <string.h>
#include <limits.h>

#undef __memrchr
#ifdef _LIBC
# undef memrchr
#endif

#ifndef weak_alias
# define __memrchr memrchr
#endif

/* Search no more than N bytes of S for C.  */
void *
__memrchr (void const *s, int c_in, size_t n)
{
  /* On 32-bit hardware, choosing longword to be a 32-bit unsigned
     long instead of a 64-bit uintmax_t tends to give better
     performance.  On 64-bit hardware, unsigned long is generally 64
     bits already.  Change this typedef to experiment with
     performance.  */
  typedef unsigned long int longword;

  const unsigned char *char_ptr;
  const longword *longword_ptr;
  longword repeated_one;
  longword repeated_c;
  unsigned reg_char c;

  c = (unsigned char) c_in;

  /* Handle the last few bytes by reading one byte at a time.
     Do this until CHAR_PTR is aligned on a longword boundary.  */
  for (char_ptr = (const unsigned char *) s + n;
       n > 0 && (size_t) char_ptr % sizeof (longword) != 0;
       --n)
    if (*--char_ptr == c)
      return (void *) char_ptr;

  longword_ptr = (const longword *) char_ptr;

  /* All these elucidatory comments refer to 4-byte longwords,
     but the theory applies equally well to any size longwords.  */

  /* Compute auxiliary longword values:
     repeated_one is a value which has a 1 in every byte.
     repeated_c has c in every byte.  */
  repeated_one = 0x01010101;
  repeated_c = c | (c << 8);
  repeated_c |= repeated_c << 16;
  if (0xffffffffU < (longword) -1)
    {
      repeated_one |= repeated_one << 31 << 1;
      repeated_c |= repeated_c << 31 << 1;
      if (8 < sizeof (longword))
	{
	  size_t i;

	  for (i = 64; i < sizeof (longword) * 8; i *= 2)
	    {
	      repeated_one |= repeated_one << i;
	      repeated_c |= repeated_c << i;
	    }
	}
    }

  /* Instead of the traditional loop which tests each byte, we will test a
     longword at a time.  The tricky part is testing if *any of the four*
     bytes in the longword in question are equal to c.  We first use an xor
     with repeated_c.  This reduces the task to testing whether *any of the
     four* bytes in longword1 is zero.

     We compute tmp =
       ((longword1 - repeated_one) & ~longword1) & (repeated_one << 7).
     That is, we perform the following operations:
       1. Subtract repeated_one.
       2. & ~longword1.
       3. & a mask consisting of 0x80 in every byte.
     Consider what happens in each byte:
       - If a byte of longword1 is zero, step 1 and 2 transform it into 0xff,
         and step 3 transforms it into 0x80.  A carry can also be propagated
         to more significant bytes.
       - If a byte of longword1 is nonzero, let its lowest 1 bit be at
         position k (0 <= k <= 7); so the lowest k bits are 0.  After step 1,
         the byte ends in a single bit of value 0 and k bits of value 1.
         After step 2, the result is just k bits of value 1: 2^k - 1.  After
         step 3, the result is 0.  And no carry is produced.
     So, if longword1 has only non-zero bytes, tmp is zero.
     Whereas if longword1 has a zero byte, call j the position of the least
     significant zero byte.  Then the result has a zero at positions 0, ...,
     j-1 and a 0x80 at position j.  We cannot predict the result at the more
     significant bytes (positions j+1..3), but it does not matter since we
     already have a non-zero bit at position 8*j+7.

     So, the test whether any byte in longword1 is zero is equivalent to
     testing whether tmp is nonzero.  */

  while (n >= sizeof (longword))
    {
      longword longword1 = *--longword_ptr ^ repeated_c;

      if ((((longword1 - repeated_one) & ~longword1)
	   & (repeated_one << 7)) != 0)
	{
	  longword_ptr++;
	  break;
	}
      n -= sizeof (longword);
    }

  char_ptr = (const unsigned char *) longword_ptr;

  /* At this point, we know that either n < sizeof (longword), or one of the
     sizeof (longword) bytes starting at char_ptr is == c.  On little-endian
     machines, we could determine the first such byte without any further
     memory accesses, just by looking at the tmp result from the last loop
     iteration.  But this does not work on big-endian machines.  Choose code
     that works in both cases.  */

  while (n-- > 0)
    {
      if (*--char_ptr == c)
	return (void *) char_ptr;
    }

  return NULL;
}
#ifdef weak_alias
weak_alias (__memrchr, memrchr)
#endif