[apt.git] / apt-inst / extract.cc

// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
// $Id: extract.cc,v 1.7 2004/01/07 20:39:37 mdz Exp $
/* ######################################################################

   Archive Extraction Directory Stream
   
   Extraction for each file is a bit of an involved process. Each object
   undergoes an atomic backup, overwrite, erase sequence. First the
   object is unpacked to '.dpkg.new' then the original is hardlinked to
   '.dpkg.tmp' and finally the new object is renamed to overwrite the old
   one. From an external perspective the file never ceased to exist.
   After the archive has been sucessfully unpacked the .dpkg.tmp files 
   are erased. A failure causes all the .dpkg.tmp files to be restored.
   
   Decisions about unpacking go like this:
      - Store the original filename in the file listing
      - Resolve any diversions that would effect this file, all checks
        below apply to the diverted name, not the real one.
      - Resolve any symlinked configuration files.
      - If the existing file does not exist then .dpkg-tmp is checked for.
        [Note, this is reduced to only check if a file was expected to be
         there]
      - If the existing link/file is not a directory then it is replaced
        irregardless
      - If the existing link/directory is being replaced by a directory then
        absolutely nothing happens.
      - If the existing link/directory is being replaced by a link then
        absolutely nothing happens.
      - If the existing link/directory is being replaced by a non-directory
        then this will abort if the package is not the sole owner of the
        directory. [Note, this is changed to not happen if the directory
        non-empty - that is, it only includes files that are part of this
        package - prevents removing user files accidentally.]
      - If the non-directory exists in the listing database and it
        does not belong to the current package then an overwrite condition
        is invoked. 
   
   As we unpack we record the file list differences in the FL cache. If
   we need to unroll the the FL cache knows which files have been unpacked
   and can undo. When we need to erase then it knows which files have not 
   been unpacked.
   
   ##################################################################### */
									/*}}}*/
// Include Files							/*{{{*/
#ifdef __GNUG__
#pragma implementation "apt-pkg/extract.h"
#endif
#include <apt-pkg/extract.h>
#include <apt-pkg/error.h>
#include <apt-pkg/debversion.h>

#include <sys/stat.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <dirent.h>
#include <iostream>
#include <apti18n.h>
									/*}}}*/
using namespace std;

static const char *TempExt = "dpkg-tmp";
//static const char *NewExt = "dpkg-new";

// Extract::pkgExtract - Constructor					/*{{{*/
// ---------------------------------------------------------------------
/* */
pkgExtract::pkgExtract(pkgFLCache &FLCache,pkgCache::VerIterator Ver) : 
                       FLCache(FLCache), Ver(Ver)
{
   FLPkg = FLCache.GetPkg(Ver.ParentPkg().Name(),true);
   if (FLPkg.end() == true)
      return;
   Debug = true;
}
									/*}}}*/
// Extract::DoItem - Handle a single item from the stream		/*{{{*/
// ---------------------------------------------------------------------
/* This performs the setup for the extraction.. */
bool pkgExtract::DoItem(Item &Itm,int &Fd)
{
   char Temp[sizeof(FileName)];
   
   /* Strip any leading/trailing /s from the filename, then copy it to the
      temp buffer and re-apply the leading / We use a class variable
      to store the new filename for use by the three extraction funcs */
   char *End = FileName+1;
   const char *I = Itm.Name;
   for (; *I != 0 && *I == '/'; I++);
   *FileName = '/';
   for (; *I != 0 && End < FileName + sizeof(FileName); I++, End++)
      *End = *I;
   if (End + 20 >= FileName + sizeof(FileName))
      return _error->Error(_("The path %s is too long"),Itm.Name);   
   for (; End > FileName && End[-1] == '/'; End--);
   *End = 0;
   Itm.Name = FileName;
   
   /* Lookup the file. Nde is the file [group] we are going to write to and
      RealNde is the actual node we are manipulating. Due to diversions
      they may be entirely different. */
   pkgFLCache::NodeIterator Nde = FLCache.GetNode(Itm.Name,End,0,false,false);
   pkgFLCache::NodeIterator RealNde = Nde;
      
   // See if the file is already in the file listing
   unsigned long FileGroup = RealNde->File;
   for (; RealNde.end() == false && FileGroup == RealNde->File; RealNde++)
      if (RealNde.RealPackage() == FLPkg)
	 break;

   // Nope, create an entry
   if (RealNde.end() == true)
   {
      RealNde = FLCache.GetNode(Itm.Name,End,FLPkg.Offset(),true,false);
      if (RealNde.end() == true)
	 return false;
      RealNde->Flags |= pkgFLCache::Node::NewFile;
   }

   /* Check if this entry already was unpacked. The only time this should 
      ever happen is if someone has hacked tar to support capabilities, in
      which case this needs to be modified anyhow.. */
   if ((RealNde->Flags & pkgFLCache::Node::Unpacked) ==
       pkgFLCache::Node::Unpacked)
      return _error->Error(_("Unpacking %s more than once"),Itm.Name);
   
   if (Nde.end() == true)
      Nde = RealNde;

   /* Consider a diverted file - We are not permitted to divert directories,
      but everything else is fair game (including conf files!) */
   if ((Nde->Flags & pkgFLCache::Node::Diversion) != 0)
   {
      if (Itm.Type == Item::Directory)
	 return _error->Error(_("The directory %s is diverted"),Itm.Name);

      /* A package overwriting a diversion target is just the same as 
         overwriting a normally owned file and is checked for below in
	 the overwrites mechanism */

      /* If this package is trying to overwrite the target of a diversion, 
         that is never, ever permitted */
      pkgFLCache::DiverIterator Div = Nde.Diversion();
      if (Div.DivertTo() == Nde)
	 return _error->Error(_("The package is trying to write to the "
			      "diversion target %s/%s"),Nde.DirN(),Nde.File());
      
      // See if it is us and we are following it in the right direction
      if (Div->OwnerPkg != FLPkg.Offset() && Div.DivertFrom() == Nde)
      {
	 Nde = Div.DivertTo();
	 End = FileName + snprintf(FileName,sizeof(FileName)-20,"%s/%s",
				   Nde.DirN(),Nde.File());
	 if (End <= FileName)
	    return _error->Error(_("The diversion path is too long"));
      }      
   }
   
   // Deal with symlinks and conf files
   if ((RealNde->Flags & pkgFLCache::Node::NewConfFile) == 
       pkgFLCache::Node::NewConfFile)
   {
      string Res = flNoLink(Itm.Name);
      if (Res.length() > sizeof(FileName))
	 return _error->Error(_("The path %s is too long"),Res.c_str());
      if (Debug == true)
	 clog << "Followed conf file from " << FileName << " to " << Res << endl;
      Itm.Name = strcpy(FileName,Res.c_str());      
   }
   
   /* Get information about the existing file, and attempt to restore
      a backup if it does not exist */
   struct stat LExisting;
   bool EValid = false;
   if (lstat(Itm.Name,&LExisting) != 0)
   {
      // This is bad news.
      if (errno != ENOENT)
	 return _error->Errno("stat",_("Failed to stat %s"),Itm.Name);
      
      // See if we can recover the backup file
      if (Nde.end() == false)
      {
	 snprintf(Temp,sizeof(Temp),"%s.%s",Itm.Name,TempExt);
	 if (rename(Temp,Itm.Name) != 0 && errno != ENOENT)
	    return _error->Errno("rename",_("Failed to rename %s to %s"),
				 Temp,Itm.Name);
	 if (stat(Itm.Name,&LExisting) != 0)
	 {
	    if (errno != ENOENT)
	       return _error->Errno("stat",_("Failed to stat %s"),Itm.Name);
	 }	 
	 else
	    EValid = true;
      }
   }
   else
      EValid = true;
   
   /* If the file is a link we need to stat its destination, get the
      existing file modes */
   struct stat Existing = LExisting;
   if (EValid == true && S_ISLNK(Existing.st_mode))
   {
      if (stat(Itm.Name,&Existing) != 0)
      {
	 if (errno != ENOENT)
	    return _error->Errno("stat",_("Failed to stat %s"),Itm.Name);
	 Existing = LExisting;
      }      
   }
   
   // We pretend a non-existing file looks like it is a normal file
   if (EValid == false)
      Existing.st_mode = S_IFREG;
   
   /* Okay, at this point 'Existing' is the stat information for the
      real non-link file */
   
   /* The only way this can be a no-op is if a directory is being
      replaced by a directory or by a link */
   if (S_ISDIR(Existing.st_mode) != 0 && 
       (Itm.Type == Item::Directory || Itm.Type == Item::SymbolicLink))
      return true;
      
   /* Non-Directory being replaced by non-directory. We check for over
      writes here. */
   if (Nde.end() == false)
   {
      if (HandleOverwrites(Nde) == false)
	 return false;
   }
   
   /* Directory being replaced by a non-directory - this needs to see if
      the package is the owner and then see if the directory would be
      empty after the package is removed [ie no user files will be 
      erased] */
   if (S_ISDIR(Existing.st_mode) != 0)
   {
      if (CheckDirReplace(Itm.Name) == false)
	 return _error->Error(_("The directory %s is being replaced by a non-directory"),Itm.Name);
   }
   
   if (Debug == true)
      clog << "Extract " << string(Itm.Name,End) << endl;
/*   if (Count != 0)
      return _error->Error(_("Done"));*/
   
   return true;
}
									/*}}}*/
// Extract::Finished - Sequence finished, erase the temp files		/*{{{*/
// ---------------------------------------------------------------------
/* */
bool pkgExtract::Finished()
{
   return true;
}
									/*}}}*/
// Extract::Aborted - Sequence aborted, undo all our unpacking		/*{{{*/
// ---------------------------------------------------------------------
/* This undoes everything that was done by all calls to the DoItem method
   and restores the File Listing cache to its original form. It bases its
   actions on the flags value for each node in the cache. */
bool pkgExtract::Aborted()
{
   if (Debug == true)
      clog << "Aborted, backing out" << endl;
   
   pkgFLCache::NodeIterator Files = FLPkg.Files();
   map_ptrloc *Last = &FLPkg->Files;
   
   /* Loop over all files, restore those that have been unpacked from their
      dpkg-tmp entires */
   while (Files.end() == false)
   {
      // Locate the hash bucket for the node and locate its group head
      pkgFLCache::NodeIterator Nde(FLCache,FLCache.HashNode(Files));
      for (; Nde.end() == false && Files->File != Nde->File; Nde++);
      if (Nde.end() == true)
	 return _error->Error(_("Failed to locate node in its hash bucket"));
      
      if (snprintf(FileName,sizeof(FileName)-20,"%s/%s",
		   Nde.DirN(),Nde.File()) <= 0)
	 return _error->Error(_("The path is too long"));
      
      // Deal with diversions
      if ((Nde->Flags & pkgFLCache::Node::Diversion) != 0)
      {
	 pkgFLCache::DiverIterator Div = Nde.Diversion();
	 
	 // See if it is us and we are following it in the right direction
	 if (Div->OwnerPkg != FLPkg.Offset() && Div.DivertFrom() == Nde)
	 {
	    Nde = Div.DivertTo();
	    if (snprintf(FileName,sizeof(FileName)-20,"%s/%s",
			 Nde.DirN(),Nde.File()) <= 0)
	       return _error->Error(_("The diversion path is too long"));
	 }
      }      
      
      // Deal with overwrites+replaces
      for (; Nde.end() == false && Files->File == Nde->File; Nde++)
      {
	 if ((Nde->Flags & pkgFLCache::Node::Replaced) == 
	     pkgFLCache::Node::Replaced)
	 {
	    if (Debug == true)
	       clog << "De-replaced " << FileName << " from " << Nde.RealPackage()->Name << endl;
	    Nde->Flags &= ~pkgFLCache::Node::Replaced;
	 }	 
      }      
      
      // Undo the change in the filesystem
      if (Debug == true)
	 clog << "Backing out " << FileName;
      
      // Remove a new node
      if ((Files->Flags & pkgFLCache::Node::NewFile) ==
	 pkgFLCache::Node::NewFile)
      {
	 if (Debug == true)
	    clog << " [new node]" << endl;
	 pkgFLCache::Node *Tmp = Files;
	 Files++;
	 *Last = Tmp->NextPkg;
	 Tmp->NextPkg = 0;

	 FLCache.DropNode(Tmp - FLCache.NodeP);
      }
      else
      {
	 if (Debug == true)
	    clog << endl;
	 
	 Last = &Files->NextPkg;
	 Files++;
      }      	 
   }
   
   return true;
}
									/*}}}*/
// Extract::Fail - Extraction of a file Failed				/*{{{*/
// ---------------------------------------------------------------------
/* */
bool pkgExtract::Fail(Item &Itm,int Fd)
{
   return pkgDirStream::Fail(Itm,Fd);
}
									/*}}}*/
// Extract::FinishedFile - Finished a file				/*{{{*/
// ---------------------------------------------------------------------
/* */
bool pkgExtract::FinishedFile(Item &Itm,int Fd)
{
   return pkgDirStream::FinishedFile(Itm,Fd);
}
									/*}}}*/
// Extract::HandleOverwrites - See if a replaces covers this overwrite	/*{{{*/
// ---------------------------------------------------------------------
/* Check if the file is in a package that is being replaced by this 
   package or if the file is being overwritten. Note that if the file
   is really a directory but it has been erased from the filesystem 
   this will fail with an overwrite message. This is a limitation of the
   dpkg file information format. 
 
   XX If a new package installs and another package replaces files in this
   package what should we do? */
bool pkgExtract::HandleOverwrites(pkgFLCache::NodeIterator Nde,
				  bool DiverCheck)
{
   pkgFLCache::NodeIterator TmpNde = Nde;
   unsigned long DiverOwner = 0;
   unsigned long FileGroup = Nde->File;
   const char *FirstOwner = 0;
   for (; Nde.end() == false && FileGroup == Nde->File; Nde++)
   {
      if ((Nde->Flags & pkgFLCache::Node::Diversion) != 0)
      {
	 /* Store the diversion owner if this is the forward direction
	    of the diversion */
	 if (DiverCheck == true)
	    DiverOwner = Nde.Diversion()->OwnerPkg;
	 continue;
      }

      pkgFLCache::PkgIterator FPkg(FLCache,Nde.RealPackage());	 
      if (FPkg.end() == true || FPkg == FLPkg)
	 continue;
      
      /* This tests trips when we are checking a diversion to see
         if something has already been diverted by this diversion */
      if (FPkg.Offset() == DiverOwner)
	 continue;
      FirstOwner = FPkg.Name();
      
      // Now see if this package matches one in a replace depends
      pkgCache::DepIterator Dep = Ver.DependsList();
      bool Ok = false;
      for (; Dep.end() == false; Dep++)
      {
	 if (Dep->Type != pkgCache::Dep::Replaces)
	    continue;
	 
	 // Does the replaces apply to this package?
	 if (strcmp(Dep.TargetPkg().Name(),FPkg.Name()) != 0)
	     continue;
	 
	 /* Check the version for match. I do not think CurrentVer can be
	    0 if we are here.. */
	 pkgCache::PkgIterator Pkg = Dep.TargetPkg();
	 if (Pkg->CurrentVer == 0)
	 {
	    _error->Warning(_("Overwrite package match with no version for %s"),Pkg.Name());
	    continue;
	 }

	 // Replaces is met
	 if (debVS.CheckDep(Pkg.CurrentVer().VerStr(),Dep->CompareOp,Dep.TargetVer()) == true)
	 {
	    if (Debug == true)
	       clog << "Replaced file " << Nde.DirN() << '/' << Nde.File() << " from " << Pkg.Name() << endl;
	    Nde->Flags |= pkgFLCache::Node::Replaced;
	    Ok = true;
	    break;
	 }
      }
      
      // Negative Hit
      if (Ok == false)
	 return _error->Error(_("File %s/%s overwrites the one in the package %s"),
			      Nde.DirN(),Nde.File(),FPkg.Name());
   }
   
   /* If this is a diversion we might have to recurse to process
      the other side of it */
   if ((TmpNde->Flags & pkgFLCache::Node::Diversion) != 0)
   {
      pkgFLCache::DiverIterator Div = TmpNde.Diversion();
      if (Div.DivertTo() == TmpNde)
	 return HandleOverwrites(Div.DivertFrom(),true);
   }
   
   return true;
}
									/*}}}*/
// Extract::CheckDirReplace - See if this directory can be erased	/*{{{*/
// ---------------------------------------------------------------------
/* If this directory is owned by a single package and that package is
   replacing it with something non-directoryish then dpkg allows this.
   We increase the requirement to be that the directory is non-empty after
   the package is removed */
bool pkgExtract::CheckDirReplace(string Dir,unsigned int Depth)
{
   // Looping?
   if (Depth > 40)
      return false;
   
   if (Dir[Dir.size() - 1] != '/')
      Dir += '/';
   
   DIR *D = opendir(Dir.c_str());
   if (D == 0)
      return _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());

   string File;
   for (struct dirent *Dent = readdir(D); Dent != 0; Dent = readdir(D))
   {
      // Skip some files
      if (strcmp(Dent->d_name,".") == 0 ||
	  strcmp(Dent->d_name,"..") == 0)
	 continue;
      
      // Look up the node
      File = Dir + Dent->d_name;
      pkgFLCache::NodeIterator Nde = FLCache.GetNode(File.c_str(),
						     File.c_str() + File.length(),0,false,false);

      // The file is not owned by this package
      if (Nde.end() != false || Nde.RealPackage() != FLPkg)
      {
	 closedir(D);
	 return false;
      }
      
      // See if it is a directory
      struct stat St;
      if (lstat(File.c_str(),&St) != 0)
      {
	 closedir(D);
	 return _error->Errno("lstat",_("Unable to stat %s"),File.c_str());
      }
      
      // Recurse down directories
      if (S_ISDIR(St.st_mode) != 0)
      {
	 if (CheckDirReplace(File,Depth + 1) == false)
	 {
	    closedir(D);
	    return false;
	 }
      }      
   }
   
   // No conflicts
   closedir(D);
   return true;
}
									/*}}}*/
Commit	Line	Data
b2e465d6 AL	1	// -- mode: cpp; mode: fold --
b2e465d6 AL	2	// Description /{{{/
d77559ac	3	// $Id: extract.cc,v 1.7 2004/01/07 20:39:37 mdz Exp $
b2e465d6 AL	4	/* ######################################################################
	5
	6	Archive Extraction Directory Stream
	7
	8	Extraction for each file is a bit of an involved process. Each object
	9	undergoes an atomic backup, overwrite, erase sequence. First the
	10	object is unpacked to '.dpkg.new' then the original is hardlinked to
	11	'.dpkg.tmp' and finally the new object is renamed to overwrite the old
	12	one. From an external perspective the file never ceased to exist.
	13	After the archive has been sucessfully unpacked the .dpkg.tmp files
	14	are erased. A failure causes all the .dpkg.tmp files to be restored.
	15
	16	Decisions about unpacking go like this:
	17	- Store the original filename in the file listing
	18	- Resolve any diversions that would effect this file, all checks
	19	below apply to the diverted name, not the real one.
	20	- Resolve any symlinked configuration files.
	21	- If the existing file does not exist then .dpkg-tmp is checked for.
	22	[Note, this is reduced to only check if a file was expected to be
	23	there]
	24	- If the existing link/file is not a directory then it is replaced
	25	irregardless
	26	- If the existing link/directory is being replaced by a directory then
	27	absolutely nothing happens.
	28	- If the existing link/directory is being replaced by a link then
	29	absolutely nothing happens.
	30	- If the existing link/directory is being replaced by a non-directory
	31	then this will abort if the package is not the sole owner of the
	32	directory. [Note, this is changed to not happen if the directory
	33	non-empty - that is, it only includes files that are part of this
	34	package - prevents removing user files accidentally.]
	35	- If the non-directory exists in the listing database and it
	36	does not belong to the current package then an overwrite condition
	37	is invoked.
	38
	39	As we unpack we record the file list differences in the FL cache. If
	40	we need to unroll the the FL cache knows which files have been unpacked
	41	and can undo. When we need to erase then it knows which files have not
	42	been unpacked.
	43
	44	##################################################################### */
	45	/}}}/
	46	// Include Files /{{{/
	47	#ifdef __GNUG__
	48	#pragma implementation "apt-pkg/extract.h"
	49	#endif
	50	#include <apt-pkg/extract.h>
	51	#include <apt-pkg/error.h>
	52	#include <apt-pkg/debversion.h>
	53
	54	#include <sys/stat.h>
	55	#include <stdio.h>
	56	#include <unistd.h>
	57	#include <errno.h>
	58	#include <dirent.h>
90f057fd	59	#include <iostream>
d77559ac	60	#include <apti18n.h>
b2e465d6	61	/}}}/
584e4558	62	using namespace std;
b2e465d6 AL	63
	64	static const char *TempExt = "dpkg-tmp";
	65	//static const char *NewExt = "dpkg-new";
	66
	67	// Extract::pkgExtract - Constructor /{{{/
	68	// ---------------------------------------------------------------------
	69	/* */
	70	pkgExtract::pkgExtract(pkgFLCache &FLCache,pkgCache::VerIterator Ver) :
	71	FLCache(FLCache), Ver(Ver)
	72	{
	73	FLPkg = FLCache.GetPkg(Ver.ParentPkg().Name(),true);
	74	if (FLPkg.end() == true)
	75	return;
	76	Debug = true;
	77	}
	78	/}}}/
	79	// Extract::DoItem - Handle a single item from the stream /{{{/
	80	// ---------------------------------------------------------------------
	81	/* This performs the setup for the extraction.. */
	82	bool pkgExtract::DoItem(Item &Itm,int &Fd)
	83	{
	84	char Temp[sizeof(FileName)];
	85
	86	/* Strip any leading/trailing /s from the filename, then copy it to the
	87	temp buffer and re-apply the leading / We use a class variable
	88	to store the new filename for use by the three extraction funcs */
	89	char *End = FileName+1;
	90	const char *I = Itm.Name;
	91	for (; I != 0 && I == '/'; I++);
	92	*FileName = '/';
	93	for (; *I != 0 && End < FileName + sizeof(FileName); I++, End++)
	94	End = I;
	95	if (End + 20 >= FileName + sizeof(FileName))
05eb7df0	96	return _error->Error(_("The path %s is too long"),Itm.Name);
b2e465d6 AL	97	for (; End > FileName && End[-1] == '/'; End--);
	98	*End = 0;
	99	Itm.Name = FileName;
	100
	101	/* Lookup the file. Nde is the file [group] we are going to write to and
	102	RealNde is the actual node we are manipulating. Due to diversions
	103	they may be entirely different. */
	104	pkgFLCache::NodeIterator Nde = FLCache.GetNode(Itm.Name,End,0,false,false);
	105	pkgFLCache::NodeIterator RealNde = Nde;
	106
	107	// See if the file is already in the file listing
	108	unsigned long FileGroup = RealNde->File;
	109	for (; RealNde.end() == false && FileGroup == RealNde->File; RealNde++)
	110	if (RealNde.RealPackage() == FLPkg)
	111	break;
	112
	113	// Nope, create an entry
	114	if (RealNde.end() == true)
	115	{
	116	RealNde = FLCache.GetNode(Itm.Name,End,FLPkg.Offset(),true,false);
	117	if (RealNde.end() == true)
	118	return false;
	119	RealNde->Flags \|= pkgFLCache::Node::NewFile;
	120	}
	121
	122	/* Check if this entry already was unpacked. The only time this should
	123	ever happen is if someone has hacked tar to support capabilities, in
	124	which case this needs to be modified anyhow.. */
	125	if ((RealNde->Flags & pkgFLCache::Node::Unpacked) ==
	126	pkgFLCache::Node::Unpacked)
05eb7df0	127	return _error->Error(_("Unpacking %s more than once"),Itm.Name);
b2e465d6 AL	128
	129	if (Nde.end() == true)
	130	Nde = RealNde;
	131
	132	/* Consider a diverted file - We are not permitted to divert directories,
	133	but everything else is fair game (including conf files!) */
	134	if ((Nde->Flags & pkgFLCache::Node::Diversion) != 0)
	135	{
	136	if (Itm.Type == Item::Directory)
05eb7df0	137	return _error->Error(_("The directory %s is diverted"),Itm.Name);
b2e465d6 AL	138
	139	/* A package overwriting a diversion target is just the same as
	140	overwriting a normally owned file and is checked for below in
	141	the overwrites mechanism */
	142
	143	/* If this package is trying to overwrite the target of a diversion,
	144	that is never, ever permitted */
	145	pkgFLCache::DiverIterator Div = Nde.Diversion();
	146	if (Div.DivertTo() == Nde)
05eb7df0 AL	147	return _error->Error(_("The package is trying to write to the "
05eb7df0 AL	148	"diversion target %s/%s"),Nde.DirN(),Nde.File());
b2e465d6 AL	149
	150	// See if it is us and we are following it in the right direction
	151	if (Div->OwnerPkg != FLPkg.Offset() && Div.DivertFrom() == Nde)
	152	{
	153	Nde = Div.DivertTo();
	154	End = FileName + snprintf(FileName,sizeof(FileName)-20,"%s/%s",
	155	Nde.DirN(),Nde.File());
	156	if (End <= FileName)
05eb7df0	157	return _error->Error(_("The diversion path is too long"));
b2e465d6 AL	158	}
	159	}
	160
	161	// Deal with symlinks and conf files
	162	if ((RealNde->Flags & pkgFLCache::Node::NewConfFile) ==
	163	pkgFLCache::Node::NewConfFile)
	164	{
	165	string Res = flNoLink(Itm.Name);
	166	if (Res.length() > sizeof(FileName))
05eb7df0	167	return _error->Error(_("The path %s is too long"),Res.c_str());
b2e465d6 AL	168	if (Debug == true)
	169	clog << "Followed conf file from " << FileName << " to " << Res << endl;
	170	Itm.Name = strcpy(FileName,Res.c_str());
	171	}
	172
	173	/* Get information about the existing file, and attempt to restore
	174	a backup if it does not exist */
	175	struct stat LExisting;
	176	bool EValid = false;
	177	if (lstat(Itm.Name,&LExisting) != 0)
	178	{
	179	// This is bad news.
	180	if (errno != ENOENT)
05eb7df0	181	return _error->Errno("stat",_("Failed to stat %s"),Itm.Name);
b2e465d6 AL	182
	183	// See if we can recover the backup file
	184	if (Nde.end() == false)
	185	{
	186	snprintf(Temp,sizeof(Temp),"%s.%s",Itm.Name,TempExt);
	187	if (rename(Temp,Itm.Name) != 0 && errno != ENOENT)
05eb7df0	188	return _error->Errno("rename",_("Failed to rename %s to %s"),
b2e465d6 AL	189	Temp,Itm.Name);
	190	if (stat(Itm.Name,&LExisting) != 0)
	191	{
	192	if (errno != ENOENT)
05eb7df0	193	return _error->Errno("stat",_("Failed to stat %s"),Itm.Name);
b2e465d6 AL	194	}
	195	else
	196	EValid = true;
	197	}
	198	}
	199	else
	200	EValid = true;
	201
	202	/* If the file is a link we need to stat its destination, get the
	203	existing file modes */
	204	struct stat Existing = LExisting;
	205	if (EValid == true && S_ISLNK(Existing.st_mode))
	206	{
	207	if (stat(Itm.Name,&Existing) != 0)
	208	{
	209	if (errno != ENOENT)
05eb7df0	210	return _error->Errno("stat",_("Failed to stat %s"),Itm.Name);
b2e465d6 AL	211	Existing = LExisting;
	212	}
	213	}
	214
	215	// We pretend a non-existing file looks like it is a normal file
	216	if (EValid == false)
	217	Existing.st_mode = S_IFREG;
	218
	219	/* Okay, at this point 'Existing' is the stat information for the
	220	real non-link file */
	221
	222	/* The only way this can be a no-op is if a directory is being
	223	replaced by a directory or by a link */
	224	if (S_ISDIR(Existing.st_mode) != 0 &&
	225	(Itm.Type == Item::Directory \|\| Itm.Type == Item::SymbolicLink))
	226	return true;
	227
	228	/* Non-Directory being replaced by non-directory. We check for over
	229	writes here. */
	230	if (Nde.end() == false)
	231	{
	232	if (HandleOverwrites(Nde) == false)
	233	return false;
	234	}
	235
	236	/* Directory being replaced by a non-directory - this needs to see if
	237	the package is the owner and then see if the directory would be
	238	empty after the package is removed [ie no user files will be
	239	erased] */
	240	if (S_ISDIR(Existing.st_mode) != 0)
	241	{
	242	if (CheckDirReplace(Itm.Name) == false)
05eb7df0	243	return _error->Error(_("The directory %s is being replaced by a non-directory"),Itm.Name);
b2e465d6 AL	244	}
	245
	246	if (Debug == true)
	247	clog << "Extract " << string(Itm.Name,End) << endl;
	248	/* if (Count != 0)
05eb7df0	249	return _error->Error(_("Done"));*/
b2e465d6 AL	250
	251	return true;
	252	}
	253	/}}}/
	254	// Extract::Finished - Sequence finished, erase the temp files /{{{/
	255	// ---------------------------------------------------------------------
	256	/* */
	257	bool pkgExtract::Finished()
	258	{
	259	return true;
	260	}
	261	/}}}/
	262	// Extract::Aborted - Sequence aborted, undo all our unpacking /{{{/
	263	// ---------------------------------------------------------------------
	264	/* This undoes everything that was done by all calls to the DoItem method
	265	and restores the File Listing cache to its original form. It bases its
	266	actions on the flags value for each node in the cache. */
	267	bool pkgExtract::Aborted()
	268	{
	269	if (Debug == true)
	270	clog << "Aborted, backing out" << endl;
	271
	272	pkgFLCache::NodeIterator Files = FLPkg.Files();
	273	map_ptrloc *Last = &FLPkg->Files;
	274
	275	/* Loop over all files, restore those that have been unpacked from their
	276	dpkg-tmp entires */
	277	while (Files.end() == false)
	278	{
	279	// Locate the hash bucket for the node and locate its group head
	280	pkgFLCache::NodeIterator Nde(FLCache,FLCache.HashNode(Files));
	281	for (; Nde.end() == false && Files->File != Nde->File; Nde++);
	282	if (Nde.end() == true)
05eb7df0	283	return _error->Error(_("Failed to locate node in its hash bucket"));
b2e465d6 AL	284
	285	if (snprintf(FileName,sizeof(FileName)-20,"%s/%s",
	286	Nde.DirN(),Nde.File()) <= 0)
05eb7df0	287	return _error->Error(_("The path is too long"));
b2e465d6 AL	288
	289	// Deal with diversions
	290	if ((Nde->Flags & pkgFLCache::Node::Diversion) != 0)
	291	{
	292	pkgFLCache::DiverIterator Div = Nde.Diversion();
	293
	294	// See if it is us and we are following it in the right direction
	295	if (Div->OwnerPkg != FLPkg.Offset() && Div.DivertFrom() == Nde)
	296	{
	297	Nde = Div.DivertTo();
	298	if (snprintf(FileName,sizeof(FileName)-20,"%s/%s",
	299	Nde.DirN(),Nde.File()) <= 0)
05eb7df0	300	return _error->Error(_("The diversion path is too long"));
b2e465d6 AL	301	}
	302	}
	303
	304	// Deal with overwrites+replaces
	305	for (; Nde.end() == false && Files->File == Nde->File; Nde++)
	306	{
	307	if ((Nde->Flags & pkgFLCache::Node::Replaced) ==
	308	pkgFLCache::Node::Replaced)
	309	{
	310	if (Debug == true)
	311	clog << "De-replaced " << FileName << " from " << Nde.RealPackage()->Name << endl;
	312	Nde->Flags &= ~pkgFLCache::Node::Replaced;
	313	}
	314	}
	315
	316	// Undo the change in the filesystem
	317	if (Debug == true)
	318	clog << "Backing out " << FileName;
	319
	320	// Remove a new node
	321	if ((Files->Flags & pkgFLCache::Node::NewFile) ==
	322	pkgFLCache::Node::NewFile)
	323	{
	324	if (Debug == true)
	325	clog << " [new node]" << endl;
	326	pkgFLCache::Node *Tmp = Files;
	327	Files++;
	328	*Last = Tmp->NextPkg;
	329	Tmp->NextPkg = 0;
	330
	331	FLCache.DropNode(Tmp - FLCache.NodeP);
	332	}
	333	else
	334	{
	335	if (Debug == true)
	336	clog << endl;
	337
	338	Last = &Files->NextPkg;
	339	Files++;
	340	}
	341	}
	342
	343	return true;
	344	}
	345	/}}}/
	346	// Extract::Fail - Extraction of a file Failed /{{{/
	347	// ---------------------------------------------------------------------
	348	/* */
	349	bool pkgExtract::Fail(Item &Itm,int Fd)
	350	{
	351	return pkgDirStream::Fail(Itm,Fd);
	352	}
	353	/}}}/
	354	// Extract::FinishedFile - Finished a file /{{{/
	355	// ---------------------------------------------------------------------
	356	/* */
	357	bool pkgExtract::FinishedFile(Item &Itm,int Fd)
	358	{
	359	return pkgDirStream::FinishedFile(Itm,Fd);
	360	}
	361	/}}}/
	362	// Extract::HandleOverwrites - See if a replaces covers this overwrite /{{{/
	363	// ---------------------------------------------------------------------
	364	/* Check if the file is in a package that is being replaced by this
365	package or if the file is being overwritten. Note that if the file
366	is really a directory but it has been erased from the filesystem
367	this will fail with an overwrite message. This is a limitation of the
368	dpkg file information format.
369
370	XX If a new package installs and another package replaces files in this
371	package what should we do? */
372	bool pkgExtract::HandleOverwrites(pkgFLCache::NodeIterator Nde,
373	bool DiverCheck)
374	{
375	pkgFLCache::NodeIterator TmpNde = Nde;
376	unsigned long DiverOwner = 0;
377	unsigned long FileGroup = Nde->File;
378	const char *FirstOwner = 0;
379	for (; Nde.end() == false && FileGroup == Nde->File; Nde++)
380	{
381	if ((Nde->Flags & pkgFLCache::Node::Diversion) != 0)
382	{
383	/* Store the diversion owner if this is the forward direction
384	of the diversion */
385	if (DiverCheck == true)
386	DiverOwner = Nde.Diversion()->OwnerPkg;
387	continue;
388	}
389
390	pkgFLCache::PkgIterator FPkg(FLCache,Nde.RealPackage());
391	if (FPkg.end() == true \|\| FPkg == FLPkg)
392	continue;
393
394	/* This tests trips when we are checking a diversion to see
395	if something has already been diverted by this diversion */
396	if (FPkg.Offset() == DiverOwner)
397	continue;
398	FirstOwner = FPkg.Name();
399
400	// Now see if this package matches one in a replace depends
401	pkgCache::DepIterator Dep = Ver.DependsList();
402	bool Ok = false;
403	for (; Dep.end() == false; Dep++)
404	{
405	if (Dep->Type != pkgCache::Dep::Replaces)
406	continue;
407
408	// Does the replaces apply to this package?
409	if (strcmp(Dep.TargetPkg().Name(),FPkg.Name()) != 0)
410	continue;
411
412	/* Check the version for match. I do not think CurrentVer can be
413	0 if we are here.. */
414	pkgCache::PkgIterator Pkg = Dep.TargetPkg();
415	if (Pkg->CurrentVer == 0)
416	{
05eb7df0	417	_error->Warning(_("Overwrite package match with no version for %s"),Pkg.Name());
b2e465d6 AL	418	continue;
	419	}
	420
	421	// Replaces is met
	422	if (debVS.CheckDep(Pkg.CurrentVer().VerStr(),Dep->CompareOp,Dep.TargetVer()) == true)
	423	{
	424	if (Debug == true)
	425	clog << "Replaced file " << Nde.DirN() << '/' << Nde.File() << " from " << Pkg.Name() << endl;
	426	Nde->Flags \|= pkgFLCache::Node::Replaced;
	427	Ok = true;
	428	break;
	429	}
	430	}
	431
	432	// Negative Hit
	433	if (Ok == false)
05eb7df0	434	return _error->Error(_("File %s/%s overwrites the one in the package %s"),
b2e465d6 AL	435	Nde.DirN(),Nde.File(),FPkg.Name());
	436	}
	437
	438	/* If this is a diversion we might have to recurse to process
	439	the other side of it */
	440	if ((TmpNde->Flags & pkgFLCache::Node::Diversion) != 0)
	441	{
	442	pkgFLCache::DiverIterator Div = TmpNde.Diversion();
	443	if (Div.DivertTo() == TmpNde)
	444	return HandleOverwrites(Div.DivertFrom(),true);
	445	}
	446
	447	return true;
	448	}
	449	/}}}/
	450	// Extract::CheckDirReplace - See if this directory can be erased /{{{/
	451	// ---------------------------------------------------------------------
	452	/* If this directory is owned by a single package and that package is
	453	replacing it with something non-directoryish then dpkg allows this.
	454	We increase the requirement to be that the directory is non-empty after
	455	the package is removed */
	456	bool pkgExtract::CheckDirReplace(string Dir,unsigned int Depth)
	457	{
	458	// Looping?
	459	if (Depth > 40)
	460	return false;
	461
	462	if (Dir[Dir.size() - 1] != '/')
	463	Dir += '/';
	464
	465	DIR *D = opendir(Dir.c_str());
	466	if (D == 0)
05eb7df0	467	return _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());
b2e465d6 AL	468
	469	string File;
	470	for (struct dirent *Dent = readdir(D); Dent != 0; Dent = readdir(D))
	471	{
	472	// Skip some files
	473	if (strcmp(Dent->d_name,".") == 0 \|\|
	474	strcmp(Dent->d_name,"..") == 0)
	475	continue;
	476
	477	// Look up the node
	478	File = Dir + Dent->d_name;
18255546 AL	479	pkgFLCache::NodeIterator Nde = FLCache.GetNode(File.c_str(),
18255546 AL	480	File.c_str() + File.length(),0,false,false);
b2e465d6 AL	481
	482	// The file is not owned by this package
	483	if (Nde.end() != false \|\| Nde.RealPackage() != FLPkg)
	484	{
	485	closedir(D);
	486	return false;
	487	}
	488
	489	// See if it is a directory
	490	struct stat St;
	491	if (lstat(File.c_str(),&St) != 0)
	492	{
	493	closedir(D);
05eb7df0	494	return _error->Errno("lstat",_("Unable to stat %s"),File.c_str());
b2e465d6 AL	495	}
	496
	497	// Recurse down directories
	498	if (S_ISDIR(St.st_mode) != 0)
	499	{
	500	if (CheckDirReplace(File,Depth + 1) == false)
	501	{
	502	closedir(D);
	503	return false;
	504	}
	505	}
	506	}
	507
	508	// No conflicts
	509	closedir(D);
	510	return true;
	511	}
	512	/}}}/