apt-pkg/contrib/fileutl.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: fileutl.h,v 1.26 2001/05/07 05:06:52 jgg Exp $
   4 /* ######################################################################
   5
   6    File Utilities
   7
   8    CopyFile - Buffered copy of a single file
   9    GetLock - dpkg compatible lock file manipulation (fcntl)
  10    FileExists - Returns true if the file exists
  11    SafeGetCWD - Returns the CWD in a string with overrun protection
  12
  13    The file class is a handy abstraction for various functions+classes
  14    that need to accept filenames.
  15
  16    This source is placed in the Public Domain, do with it what you will
  17    It was originally written by Jason Gunthorpe.
  18
  19    ##################################################################### */
  20                                                                         /*}}}*/
  21 #ifndef PKGLIB_FILEUTL_H
  22 #define PKGLIB_FILEUTL_H
  23
  24 #include <apt-pkg/macros.h>
  25 #include <apt-pkg/aptconfiguration.h>
  26
  27 #include <string>
  28 #include <vector>
  29 #include <set>
  30 #include <time.h>
  31
  32 #include <zlib.h>
  33
  34 #ifndef APT_8_CLEANER_HEADERS
  35 using std::string;
  36 #endif
  37
  38 /* Define this for python-apt */
  39 #define APT_HAS_GZIP 1
  40
  41 class FileFdPrivate;
  42 class FileFd
  43 {
  44    friend class FileFdPrivate;
  45    friend class GzipFileFdPrivate;
  46    friend class Bz2FileFdPrivate;
  47    friend class LzmaFileFdPrivate;
  48    friend class Lz4FileFdPrivate;
  49    friend class DirectFileFdPrivate;
  50    friend class PipedFileFdPrivate;
  51    protected:
  52    int iFd;
  53
  54    enum LocalFlags {AutoClose = (1<<0),Fail = (1<<1),DelOnFail = (1<<2),
  55                     HitEof = (1<<3), Replace = (1<<4), Compressed = (1<<5) };
  56    unsigned long Flags;
  57    std::string FileName;
  58    std::string TemporaryFileName;
  59
  60    public:
  61    enum OpenMode {
  62         ReadOnly = (1 << 0),
  63         WriteOnly = (1 << 1),
  64         ReadWrite = ReadOnly | WriteOnly,
  65
  66         Create = (1 << 2),
  67         Exclusive = (1 << 3),
  68         Atomic = Exclusive | (1 << 4),
  69         Empty = (1 << 5),
  70         BufferedWrite = (1 << 6),
  71
  72         WriteEmpty = ReadWrite | Create | Empty,
  73         WriteExists = ReadWrite,
  74         WriteAny = ReadWrite | Create,
  75         WriteTemp = ReadWrite | Create | Exclusive,
  76         ReadOnlyGzip,
  77         WriteAtomic = ReadWrite | Create | Atomic
  78    };
  79    enum CompressMode { Auto = 'A', None = 'N', Extension = 'E', Gzip = 'G', Bzip2 = 'B', Lzma = 'L', Xz = 'X', Lz4='4' };
  80
  81    inline bool Read(void *To,unsigned long long Size,bool AllowEof)
  82    {
  83       unsigned long long Jnk;
  84       if (AllowEof)
  85          return Read(To,Size,&Jnk);
  86       return Read(To,Size);
  87    }
  88    bool Read(void *To,unsigned long long Size,unsigned long long *Actual = 0);
  89    char* ReadLine(char *To, unsigned long long const Size);
  90    bool Flush();
  91    bool Write(const void *From,unsigned long long Size);
  92    bool static Write(int Fd, const void *From, unsigned long long Size);
  93    bool Seek(unsigned long long To);
  94    bool Skip(unsigned long long To);
  95    bool Truncate(unsigned long long To);
  96    unsigned long long Tell();
  97    // the size of the file content (compressed files will be uncompressed first)
  98    unsigned long long Size();
  99    // the size of the file itself
 100    unsigned long long FileSize();
 101    time_t ModificationTime();
 102
 103    /* You want to use 'unsigned long long' if you are talking about a file
 104       to be able to support large files (>2 or >4 GB) properly.
 105       This shouldn't happen all to often for the indexes, but deb's might be…
 106       And as the auto-conversation converts a 'unsigned long *' to a 'bool'
 107       instead of 'unsigned long long *' we need to provide this explicitly -
 108       otherwise applications magically start to fail… */
 109    bool Read(void *To,unsigned long long Size,unsigned long *Actual) APT_DEPRECATED_MSG("The Actual variable you pass in should be an unsigned long long")
 110    {
 111         unsigned long long R;
 112         bool const T = Read(To, Size, &R);
 113         *Actual = R;
 114         return T;
 115    }
 116
 117    bool Open(std::string FileName,unsigned int const Mode,CompressMode Compress,unsigned long const AccessMode = 0666);
 118    bool Open(std::string FileName,unsigned int const Mode,APT::Configuration::Compressor const &compressor,unsigned long const AccessMode = 0666);
 119    inline bool Open(std::string const &FileName,unsigned int const Mode, unsigned long const AccessMode = 0666) {
 120       return Open(FileName, Mode, None, AccessMode);
 121    };
 122    bool OpenDescriptor(int Fd, unsigned int const Mode, CompressMode Compress, bool AutoClose=false);
 123    bool OpenDescriptor(int Fd, unsigned int const Mode, APT::Configuration::Compressor const &compressor, bool AutoClose=false);
 124    inline bool OpenDescriptor(int Fd, unsigned int const Mode, bool AutoClose=false) {
 125       return OpenDescriptor(Fd, Mode, None, AutoClose);
 126    };
 127    bool Close();
 128    bool Sync();
 129
 130    // Simple manipulators
 131    inline int Fd() {return iFd;};
 132    inline void Fd(int fd) { OpenDescriptor(fd, ReadWrite);};
 133    gzFile gzFd() APT_DEPRECATED_MSG("Implementation detail, do not use to be able to support bzip2, xz and co") APT_PURE;
 134
 135    inline bool IsOpen() {return iFd >= 0;};
 136    inline bool Failed() {return (Flags & Fail) == Fail;};
 137    inline void EraseOnFailure() {Flags |= DelOnFail;};
 138    inline void OpFail() {Flags |= Fail;};
 139    inline bool Eof() {return (Flags & HitEof) == HitEof;};
 140    inline bool IsCompressed() {return (Flags & Compressed) == Compressed;};
 141    inline std::string &Name() {return FileName;};
 142
 143    FileFd(std::string FileName,unsigned int const Mode,unsigned long AccessMode = 0666);
 144    FileFd(std::string FileName,unsigned int const Mode, CompressMode Compress, unsigned long AccessMode = 0666);
 145    FileFd();
 146    FileFd(int const Fd, unsigned int const Mode = ReadWrite, CompressMode Compress = None);
 147    FileFd(int const Fd, bool const AutoClose);
 148    virtual ~FileFd();
 149
 150    private:
 151    FileFdPrivate * d;
 152    APT_HIDDEN FileFd & operator=(const FileFd &);
 153    APT_HIDDEN bool OpenInternDescriptor(unsigned int const Mode, APT::Configuration::Compressor const &compressor);
 154
 155    // private helpers to set Fail flag and call _error->Error
 156    APT_HIDDEN bool FileFdErrno(const char* Function, const char* Description,...) APT_PRINTF(3) APT_COLD;
 157    APT_HIDDEN bool FileFdError(const char* Description,...) APT_PRINTF(2) APT_COLD;
 158 };
 159
 160 bool RunScripts(const char *Cnf);
 161 bool CopyFile(FileFd &From,FileFd &To);
 162 bool RemoveFile(char const * const Function, std::string const &FileName);
 163 int GetLock(std::string File,bool Errors = true);
 164 bool FileExists(std::string File);
 165 bool RealFileExists(std::string File);
 166 bool DirectoryExists(std::string const &Path) APT_CONST;
 167 bool CreateDirectory(std::string const &Parent, std::string const &Path);
 168 time_t GetModificationTime(std::string const &Path);
 169 bool Rename(std::string From, std::string To);
 170
 171 std::string GetTempDir();
 172 std::string GetTempDir(std::string const &User);
 173 FileFd* GetTempFile(std::string const &Prefix = "",
 174                     bool ImmediateUnlink = true,
 175                     FileFd * const TmpFd = NULL);
 176
 177 /** \brief Ensure the existence of the given Path
 178  *
 179  *  \param Parent directory of the Path directory - a trailing
 180  *  /apt/ will be removed before CreateDirectory call.
 181  *  \param Path which should exist after (successful) call
 182  */
 183 bool CreateAPTDirectoryIfNeeded(std::string const &Parent, std::string const &Path);
 184
 185 std::vector<std::string> GetListOfFilesInDir(std::string const &Dir, std::string const &Ext,
 186                                         bool const &SortList, bool const &AllowNoExt=false);
 187 std::vector<std::string> GetListOfFilesInDir(std::string const &Dir, std::vector<std::string> const &Ext,
 188                                         bool const &SortList);
 189 std::vector<std::string> GetListOfFilesInDir(std::string const &Dir, bool SortList);
 190 std::string SafeGetCWD();
 191 void SetCloseExec(int Fd,bool Close);
 192 void SetNonBlock(int Fd,bool Block);
 193 bool WaitFd(int Fd,bool write = false,unsigned long timeout = 0);
 194 pid_t ExecFork();
 195 pid_t ExecFork(std::set<int> keep_fds);
 196 void MergeKeepFdsFromConfiguration(std::set<int> &keep_fds);
 197 bool ExecWait(pid_t Pid,const char *Name,bool Reap = false);
 198
 199 // check if the given file starts with a PGP cleartext signature
 200 bool StartsWithGPGClearTextSignature(std::string const &FileName);
 201
 202 /** change file attributes to requested known good values
 203  *
 204  * The method skips the user:group setting if not root.
 205  *
 206  * @param requester is printed as functionname in error cases
 207  * @param file is the file to be modified
 208  * @param user is the (new) owner of the file, e.g. _apt
 209  * @param group is the (new) group owning the file, e.g. root
 210  * @param mode is the access mode of the file, e.g. 0644
 211  */
 212 bool ChangeOwnerAndPermissionOfFile(char const * const requester, char const * const file, char const * const user, char const * const group, mode_t const mode);
 213
 214 /**
 215  * \brief Drop privileges
 216  *
 217  * Drop the privileges to the user _apt (or the one specified in
 218  * APT::Sandbox::User). This does not set the supplementary group
 219  * ids up correctly, it only uses the default group. Also prevent
 220  * the process from gaining any new privileges afterwards, at least
 221  * on Linux.
 222  *
 223  * \return true on success, false on failure with _error set
 224  */
 225 bool DropPrivileges();
 226
 227 // File string manipulators
 228 std::string flNotDir(std::string File);
 229 std::string flNotFile(std::string File);
 230 std::string flNoLink(std::string File);
 231 std::string flExtension(std::string File);
 232 std::string flCombine(std::string Dir,std::string File);
 233
 234 /** \brief Takes a file path and returns the absolute path
 235  */
 236 std::string flAbsPath(std::string File);
 237
 238 // simple c++ glob
 239 std::vector<std::string> Glob(std::string const &pattern, int flags=0);
 240
 241 /** \brief Popen() implementation that execv() instead of using a shell
 242  *
 243  * \param Args the execv style command to run
 244  * \param FileFd is a referenz to the FileFd to use for input or output
 245  * \param Child a reference to the integer that stores the child pid
 246  *        Note that you must call ExecWait() or similar to cleanup
 247  * \param Mode is either FileFd::ReadOnly or FileFd::WriteOnly
 248  * \return true on success, false on failure with _error set
 249  */
 250 bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode);
 251
 252
 253 #endif