diff options
Diffstat (limited to 'apt-inst/deb')
| -rw-r--r-- | apt-inst/deb/debfile.cc | 265 | ||||
| -rw-r--r-- | apt-inst/deb/debfile.h | 95 |
2 files changed, 360 insertions, 0 deletions
diff --git a/apt-inst/deb/debfile.cc b/apt-inst/deb/debfile.cc new file mode 100644 index 0000000..bef0cd0 --- /dev/null +++ b/apt-inst/deb/debfile.cc @@ -0,0 +1,265 @@ +// -*- mode: cpp; mode: fold -*- +// Description /*{{{*/ +/* ###################################################################### + + Debian Archive File (.deb) + + .DEB archives are AR files containing two tars and an empty marker + member called 'debian-binary'. The two tars contain the meta data and + the actual archive contents. Thus this class is a very simple wrapper + around ar/tar to simply extract the right tar files. + + It also uses the deb package list parser to parse the control file + into the cache. + + ##################################################################### */ + /*}}}*/ +// Include Files /*{{{*/ +#include <config.h> + +#include <apt-pkg/aptconfiguration.h> +#include <apt-pkg/arfile.h> +#include <apt-pkg/debfile.h> +#include <apt-pkg/dirstream.h> +#include <apt-pkg/error.h> +#include <apt-pkg/extracttar.h> +#include <apt-pkg/fileutl.h> +#include <apt-pkg/tagfile.h> + +#include <string> +#include <vector> +#include <string.h> +#include <sys/stat.h> + +#include <apti18n.h> + /*}}}*/ + +// DebFile::debDebFile - Constructor /*{{{*/ +// --------------------------------------------------------------------- +/* Open the AR file and check for consistency */ +debDebFile::debDebFile(FileFd &File) : File(File), AR(File) +{ + if (_error->PendingError() == true) + return; + + if (!CheckMember("debian-binary")) { + _error->Error(_("This is not a valid DEB archive, missing '%s' member"), "debian-binary"); + return; + } + + if (!CheckMember("control.tar") && + !CheckMember("control.tar.gz") && + !CheckMember("control.tar.xz") && + !CheckMember("control.tar.zst")) + { + _error->Error(_("This is not a valid DEB archive, missing '%s' member"), "control.tar"); + return; + } + + if (!CheckMember("data.tar") && + !CheckMember("data.tar.gz") && + !CheckMember("data.tar.bz2") && + !CheckMember("data.tar.lzma") && + !CheckMember("data.tar.xz") && + !CheckMember("data.tar.zst")) + { + _error->Error(_("This is not a valid DEB archive, missing '%s' member"), "data.tar"); + return; + } +} + /*}}}*/ +// DebFile::CheckMember - Check if a named member is in the archive /*{{{*/ +// --------------------------------------------------------------------- +/* This is used to check for a correct deb and to give nicer error messages + for people playing around. */ +bool debDebFile::CheckMember(const char *Name) +{ + if (AR.FindMember(Name) == 0) + return false; + return true; +} + /*}}}*/ +// DebFile::GotoMember - Jump to a Member /*{{{*/ +// --------------------------------------------------------------------- +/* Jump in the file to the start of a named member and return the information + about that member. The caller can then read from the file up to the + returned size. Note, since this relies on the file position this is + a destructive operation, it also changes the last returned Member + structure - so don't nest them! */ +const ARArchive::Member *debDebFile::GotoMember(const char *Name) +{ + // Get the archive member and positition the file + const ARArchive::Member *Member = AR.FindMember(Name); + if (Member == 0) + { + return 0; + } + if (File.Seek(Member->Start) == false) + return 0; + + return Member; +} + /*}}}*/ +// DebFile::ExtractTarMember - Extract the contents of a tar member /*{{{*/ +// --------------------------------------------------------------------- +/* Simple wrapper around tar.. */ +bool debDebFile::ExtractTarMember(pkgDirStream &Stream,const char *Name) +{ + // Get the archive member + const ARArchive::Member *Member = NULL; + std::string Compressor; + + std::vector<APT::Configuration::Compressor> compressor = APT::Configuration::getCompressors(); + for (std::vector<APT::Configuration::Compressor>::const_iterator c = compressor.begin(); + c != compressor.end(); ++c) + { + Member = AR.FindMember(std::string(Name).append(c->Extension).c_str()); + if (Member == NULL) + continue; + Compressor = c->Name; + break; + } + + if (Member == NULL) + Member = AR.FindMember(std::string(Name).c_str()); + + if (Member == NULL) + { + std::string ext = std::string(Name) + ".{"; + for (std::vector<APT::Configuration::Compressor>::const_iterator c = compressor.begin(); + c != compressor.end(); ++c) { + if (!c->Extension.empty()) + ext.append(c->Extension.substr(1)); + } + ext.append("}"); + return _error->Error(_("Internal error, could not locate member %s"), ext.c_str()); + } + + if (File.Seek(Member->Start) == false) + return false; + + // Prepare Tar + ExtractTar Tar(File,Member->Size,Compressor); + if (_error->PendingError() == true) + return false; + return Tar.Go(Stream); +} + /*}}}*/ +// DebFile::ExtractArchive - Extract the archive data itself /*{{{*/ +// --------------------------------------------------------------------- +/* Simple wrapper around DebFile::ExtractTarMember. */ +bool debDebFile::ExtractArchive(pkgDirStream &Stream) +{ + return ExtractTarMember(Stream, "data.tar"); +} + /*}}}*/ + +// DebFile::ControlExtract::DoItem - Control Tar Extraction /*{{{*/ +// --------------------------------------------------------------------- +/* This directory stream handler for the control tar handles extracting + it into the temporary meta directory. It only extracts files, it does + not create directories, links or anything else. */ +bool debDebFile::ControlExtract::DoItem(Item &Itm,int &Fd) +{ + if (Itm.Type != Item::File) + return true; + + /* Cleanse the file name, prevent people from trying to unpack into + absolute paths, .., etc */ + for (char *I = Itm.Name; *I != 0; I++) + if (*I == '/') + *I = '_'; + + /* Force the ownership to be root and ensure correct permissions, + go-w, the rest are left untouched */ + Itm.UID = 0; + Itm.GID = 0; + Itm.Mode &= ~(S_IWGRP | S_IWOTH); + + return pkgDirStream::DoItem(Itm,Fd); +} + /*}}}*/ + +// MemControlExtract::DoItem - Check if it is the control file /*{{{*/ +// --------------------------------------------------------------------- +/* This sets up to extract the control block member file into a memory + block of just the right size. All other files go into the bit bucket. */ + +// Upper size limit for control files. Two reasons for having a limit here: +// +// 1. We read those files into memory and want to avoid being killed by OOM +// +// 2. We allocate (Itm.Size+2)-large arrays, so this can overflow if Itm.Size +// becomes 2**64-2 or larger. This is obviously +// +// 64 MiB seems like a terribly large size that everyone should be happy with. +static const unsigned long long DEB_CONTROL_SIZE_LIMIT = 64 * 1024 * 1024; +bool debDebFile::MemControlExtract::DoItem(Item &Itm,int &Fd) +{ + // At the control file, allocate buffer memory. + if (Member == Itm.Name) + { + if (Itm.Size > DEB_CONTROL_SIZE_LIMIT) + return _error->Error("Control file too large: %llu > %llu bytes", Itm.Size, DEB_CONTROL_SIZE_LIMIT); + delete [] Control; + Control = new char[Itm.Size+2]; + IsControl = true; + Fd = -2; // Signal to pass to Process + Length = Itm.Size; + } + else + IsControl = false; + + return true; +} + /*}}}*/ +// MemControlExtract::Process - Process extracting the control file /*{{{*/ +// --------------------------------------------------------------------- +/* Just memcopy the block from the tar extractor and put it in the right + place in the pre-allocated memory block. */ +bool debDebFile::MemControlExtract::Process(Item &/*Itm*/,const unsigned char *Data, + unsigned long long Size,unsigned long long Pos) +{ + memcpy(Control + Pos, Data,Size); + return true; +} + /*}}}*/ +// MemControlExtract::Read - Read the control information from the deb /*{{{*/ +// --------------------------------------------------------------------- +/* This uses the internal tar extractor to fetch the control file, and then + it parses it into a tag section parser. */ +bool debDebFile::MemControlExtract::Read(debDebFile &Deb) +{ + if (Deb.ExtractTarMember(*this, "control.tar") == false) + return false; + + if (Control == 0) + return true; + + Control[Length] = '\n'; + Control[Length+1] = '\n'; + if (Section.Scan(Control,Length+2) == false) + return _error->Error(_("Unparsable control file")); + return true; +} + /*}}}*/ +// MemControlExtract::TakeControl - Parse a memory block /*{{{*/ +// --------------------------------------------------------------------- +/* The given memory block is loaded into the parser and parsed as a control + record. */ +bool debDebFile::MemControlExtract::TakeControl(const void *Data,unsigned long long Size) +{ + if (Size > DEB_CONTROL_SIZE_LIMIT) + return _error->Error("Control file too large: %llu > %llu bytes", Size, DEB_CONTROL_SIZE_LIMIT); + + delete [] Control; + Control = new char[Size+2]; + Length = Size; + memcpy(Control,Data,Size); + + Control[Length] = '\n'; + Control[Length+1] = '\n'; + return Section.Scan(Control,Length+2); +} + /*}}}*/ + diff --git a/apt-inst/deb/debfile.h b/apt-inst/deb/debfile.h new file mode 100644 index 0000000..23a76bf --- /dev/null +++ b/apt-inst/deb/debfile.h @@ -0,0 +1,95 @@ +// -*- mode: cpp; mode: fold -*- +// Description /*{{{*/ +/* ###################################################################### + + Debian Archive File (.deb) + + This Class handles all the operations performed directly on .deb + files. It makes use of the AR and TAR classes to give the necessary + external interface. + + There are only two things that can be done with a raw package, + extract it's control information and extract the contents itself. + + This should probably subclass an as-yet unwritten super class to + produce a generic archive mechanism. + + The memory control file extractor is useful to extract a single file + into memory from the control.tar.gz + + ##################################################################### */ + /*}}}*/ +#ifndef PKGLIB_DEBFILE_H +#define PKGLIB_DEBFILE_H + +#include <apt-pkg/arfile.h> +#include <apt-pkg/dirstream.h> +#include <apt-pkg/macros.h> +#include <apt-pkg/tagfile.h> + +#include <string> + +#ifndef APT_8_CLEANER_HEADERS +#include <apt-pkg/md5.h> +#endif +#ifndef APT_10_CLEANER_HEADERS +#include <apt-pkg/pkgcache.h> +#endif + +class FileFd; + +class debDebFile +{ + protected: + + FileFd &File; + ARArchive AR; + + bool CheckMember(const char *Name); + + public: + class ControlExtract; + class MemControlExtract; + + bool ExtractTarMember(pkgDirStream &Stream, const char *Name); + bool ExtractArchive(pkgDirStream &Stream); + const ARArchive::Member *GotoMember(const char *Name); + inline FileFd &GetFile() {return File;}; + + debDebFile(FileFd &File); +}; + +class debDebFile::ControlExtract : public pkgDirStream +{ + public: + + virtual bool DoItem(Item &Itm,int &Fd) APT_OVERRIDE; +}; + +class debDebFile::MemControlExtract : public pkgDirStream +{ + bool IsControl; + + public: + + char *Control; + pkgTagSection Section; + unsigned long Length; + std::string Member; + + // Members from DirStream + virtual bool DoItem(Item &Itm,int &Fd) APT_OVERRIDE; + virtual bool Process(Item &Itm,const unsigned char *Data, + unsigned long long Size,unsigned long long Pos) APT_OVERRIDE; + + // Helpers + bool Read(debDebFile &Deb); + bool TakeControl(const void *Data,unsigned long long Size); + + MemControlExtract() : IsControl(false), Control(0), Length(0), Member("control") {}; + MemControlExtract(std::string Member) : IsControl(false), Control(0), Length(0), Member(Member) {}; + ~MemControlExtract() {delete [] Control;}; +}; + /*}}}*/ + +#endif |