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Diffstat (limited to 'apt-inst/extract.cc')
| -rw-r--r-- | apt-inst/extract.cc | 514 |
1 files changed, 0 insertions, 514 deletions
diff --git a/apt-inst/extract.cc b/apt-inst/extract.cc deleted file mode 100644 index 35fa015e7..000000000 --- a/apt-inst/extract.cc +++ /dev/null @@ -1,514 +0,0 @@ -// -*- mode: cpp; mode: fold -*- -// Description /*{{{*/ -/* ###################################################################### - - 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 successfully 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 - regardless - - 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 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 /*{{{*/ -#include <config.h> - -#include <apt-pkg/debversion.h> -#include <apt-pkg/dirstream.h> -#include <apt-pkg/error.h> -#include <apt-pkg/extract.h> -#include <apt-pkg/filelist.h> -#include <apt-pkg/fileutl.h> -#include <apt-pkg/mmap.h> -#include <apt-pkg/pkgcache.h> - -#include <iostream> -#include <string> -#include <dirent.h> -#include <errno.h> -#include <stdio.h> -#include <string.h> -#include <sys/stat.h> - -#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*/) -{ - /* 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) - { - char Temp[sizeof(FileName)]; - 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 /*{{{*/ -// --------------------------------------------------------------------- -/* */ -APT_PURE 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 entries */ - 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; - 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; - - // 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; -} - /*}}}*/ |