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Diffstat (limited to 'apt-pkg/contrib/fileutl.cc')
| -rw-r--r-- | apt-pkg/contrib/fileutl.cc | 3443 |
1 files changed, 3443 insertions, 0 deletions
diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc new file mode 100644 index 0000000..4f12349 --- /dev/null +++ b/apt-pkg/contrib/fileutl.cc @@ -0,0 +1,3443 @@ +// -*- mode: cpp; mode: fold -*- +// Description /*{{{*/ +/* ###################################################################### + + File Utilities + + CopyFile - Buffered copy of a single file + GetLock - dpkg compatible lock file manipulation (fcntl) + + Most of this source is placed in the Public Domain, do with it what + you will + It was originally written by Jason Gunthorpe <jgg@debian.org>. + FileFd gzip support added by Martin Pitt <martin.pitt@canonical.com> + + The exception is RunScripts() it is under the GPLv2 + + ##################################################################### */ + /*}}}*/ +// Include Files /*{{{*/ +#include <config.h> + +#include <apt-pkg/aptconfiguration.h> +#include <apt-pkg/configuration.h> +#include <apt-pkg/error.h> +#include <apt-pkg/fileutl.h> +#include <apt-pkg/macros.h> +#include <apt-pkg/pkgsystem.h> +#include <apt-pkg/sptr.h> +#include <apt-pkg/strutl.h> + +#include <cstdio> +#include <cstdlib> +#include <cstring> +#include <iostream> +#include <string> +#include <vector> +#include <ctype.h> +#include <dirent.h> +#include <errno.h> +#include <fcntl.h> +#include <glob.h> +#include <grp.h> +#include <pwd.h> +#include <signal.h> +#include <stdarg.h> +#include <stddef.h> +#include <stdio.h> +#include <sys/select.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/wait.h> +#include <time.h> +#include <unistd.h> + +#include <algorithm> +#include <memory> +#include <set> + +#ifdef HAVE_ZLIB +#include <zlib.h> +#endif +#ifdef HAVE_BZ2 +#include <bzlib.h> +#endif +#ifdef HAVE_LZMA +#include <lzma.h> +#endif +#ifdef HAVE_LZ4 +#include <lz4frame.h> +#endif +#ifdef HAVE_ZSTD +#include <zstd.h> +#endif +#ifdef HAVE_SYSTEMD +#include <systemd/sd-bus.h> +#endif +#include <endian.h> +#include <stdint.h> + +#if __gnu_linux__ +#include <sys/prctl.h> +#endif + +#include <apti18n.h> + /*}}}*/ + +using namespace std; + +/* Should be a multiple of the common page size (4096) */ +static constexpr unsigned long long APT_BUFFER_SIZE = 64 * 1024; + +// RunScripts - Run a set of scripts from a configuration subtree /*{{{*/ +// --------------------------------------------------------------------- +/* */ +bool RunScripts(const char *Cnf) +{ + Configuration::Item const *Opts = _config->Tree(Cnf); + if (Opts == 0 || Opts->Child == 0) + return true; + Opts = Opts->Child; + + // Fork for running the system calls + pid_t Child = ExecFork(); + + // This is the child + if (Child == 0) + { + if (_system != nullptr && _system->IsLocked() == true && (stringcasecmp(Cnf, "dpkg::post-invoke") == 0 || stringcasecmp(Cnf, "dpkg::pre-invoke") == 0)) + setenv("DPKG_FRONTEND_LOCKED", "true", 1); + 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("/tmp/") != 0) + _exit(100); + + unsigned int Count = 1; + for (; Opts != 0; Opts = Opts->Next, Count++) + { + if (Opts->Value.empty() == true) + continue; + + if(_config->FindB("Debug::RunScripts", false) == true) + std::clog << "Running external script: '" + << Opts->Value << "'" << std::endl; + + if (system(Opts->Value.c_str()) != 0) + _exit(100+Count); + } + _exit(0); + } + + // Wait for the child + int Status = 0; + while (waitpid(Child,&Status,0) != Child) + { + if (errno == EINTR) + continue; + return _error->Errno("waitpid","Couldn't wait for subprocess"); + } + + // Restore sig int/quit + signal(SIGQUIT,SIG_DFL); + signal(SIGINT,SIG_DFL); + + // Check for an error code. + if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0) + { + unsigned int Count = WEXITSTATUS(Status); + if (Count > 100) + { + Count -= 100; + for (; Opts != 0 && Count != 1; Opts = Opts->Next, Count--); + _error->Error("Problem executing scripts %s '%s'",Cnf,Opts->Value.c_str()); + } + + return _error->Error("Sub-process returned an error code"); + } + + return true; +} + /*}}}*/ + +// CopyFile - Buffered copy of a file /*{{{*/ +// --------------------------------------------------------------------- +/* The caller is expected to set things so that failure causes erasure */ +bool CopyFile(FileFd &From,FileFd &To) +{ + if (From.IsOpen() == false || To.IsOpen() == false || + From.Failed() == true || To.Failed() == true) + return false; + + // Buffered copy between fds + constexpr size_t BufSize = APT_BUFFER_SIZE; + std::unique_ptr<unsigned char[]> Buf(new unsigned char[BufSize]); + unsigned long long ToRead = 0; + do { + if (From.Read(Buf.get(),BufSize, &ToRead) == false || + To.Write(Buf.get(),ToRead) == false) + return false; + } while (ToRead != 0); + + return true; +} + /*}}}*/ +bool RemoveFileAt(char const * const Function, int const dirfd, std::string const &FileName)/*{{{*/ +{ + if (FileName == "/dev/null") + return true; + errno = 0; + if (unlinkat(dirfd, FileName.c_str(), 0) != 0) + { + if (errno == ENOENT) + return true; + + return _error->WarningE(Function,_("Problem unlinking the file %s"), FileName.c_str()); + } + return true; +} + /*}}}*/ +bool RemoveFile(char const * const Function, std::string const &FileName)/*{{{*/ +{ + if (FileName == "/dev/null") + return true; + errno = 0; + if (unlink(FileName.c_str()) != 0) + { + if (errno == ENOENT) + return true; + + return _error->WarningE(Function,_("Problem unlinking the file %s"), FileName.c_str()); + } + return true; +} + /*}}}*/ +// GetLock - Gets a lock file /*{{{*/ +// --------------------------------------------------------------------- +/* This will create an empty file of the given name and lock it. Once this + is done all other calls to GetLock in any other process will fail with + -1. The return result is the fd of the file, the call should call + close at some time. */ +int GetLock(string File,bool Errors) +{ + // GetLock() is used in aptitude on directories with public-write access + // Use O_NOFOLLOW here to prevent symlink traversal attacks + int FD = open(File.c_str(),O_RDWR | O_CREAT | O_NOFOLLOW,0640); + if (FD < 0) + { + // Read only .. can't have locking problems there. + if (errno == EROFS) + { + _error->Warning(_("Not using locking for read only lock file %s"),File.c_str()); + return dup(0); // Need something for the caller to close + } + + if (Errors == true) + _error->Errno("open",_("Could not open lock file %s"),File.c_str()); + + // Feh.. We do this to distinguish the lock vs open case.. + errno = EPERM; + return -1; + } + SetCloseExec(FD,true); + + // Acquire a write lock + struct flock fl; + fl.l_type = F_WRLCK; + fl.l_whence = SEEK_SET; + fl.l_start = 0; + fl.l_len = 0; + if (fcntl(FD,F_SETLK,&fl) == -1) + { + // always close to not leak resources + int Tmp = errno; + close(FD); + errno = Tmp; + + if (errno == ENOLCK) + { + _error->Warning(_("Not using locking for nfs mounted lock file %s"),File.c_str()); + return dup(0); // Need something for the caller to close + } + + if (Errors == true) + _error->Errno("open",_("Could not get lock %s"),File.c_str()); + + return -1; + } + + return FD; +} + /*}}}*/ +// FileExists - Check if a file exists /*{{{*/ +// --------------------------------------------------------------------- +/* Beware: Directories are also files! */ +bool FileExists(string File) +{ + struct stat Buf; + if (stat(File.c_str(),&Buf) != 0) + return false; + return true; +} + /*}}}*/ +// RealFileExists - Check if a file exists and if it is really a file /*{{{*/ +// --------------------------------------------------------------------- +/* */ +bool RealFileExists(string File) +{ + struct stat Buf; + if (stat(File.c_str(),&Buf) != 0) + return false; + return ((Buf.st_mode & S_IFREG) != 0); +} + /*}}}*/ +// DirectoryExists - Check if a directory exists and is really one /*{{{*/ +// --------------------------------------------------------------------- +/* */ +bool DirectoryExists(string const &Path) +{ + struct stat Buf; + if (stat(Path.c_str(),&Buf) != 0) + return false; + return ((Buf.st_mode & S_IFDIR) != 0); +} + /*}}}*/ +// CreateDirectory - poor man's mkdir -p guarded by a parent directory /*{{{*/ +// --------------------------------------------------------------------- +/* This method will create all directories needed for path in good old + mkdir -p style but refuses to do this if Parent is not a prefix of + this Path. Example: /var/cache/ and /var/cache/apt/archives are given, + so it will create apt/archives if /var/cache exists - on the other + hand if the parent is /var/lib the creation will fail as this path + is not a parent of the path to be generated. */ +bool CreateDirectory(string const &Parent, string const &Path) +{ + if (Parent.empty() == true || Path.empty() == true) + return false; + + if (DirectoryExists(Path) == true) + return true; + + if (DirectoryExists(Parent) == false) + return false; + + // we are not going to create directories "into the blue" + if (Path.compare(0, Parent.length(), Parent) != 0) + return false; + + vector<string> const dirs = VectorizeString(Path.substr(Parent.size()), '/'); + string progress = Parent; + for (vector<string>::const_iterator d = dirs.begin(); d != dirs.end(); ++d) + { + if (d->empty() == true) + continue; + + progress.append("/").append(*d); + if (DirectoryExists(progress) == true) + continue; + + if (mkdir(progress.c_str(), 0755) != 0) + return false; + } + return true; +} + /*}}}*/ +// CreateAPTDirectoryIfNeeded - ensure that the given directory exists /*{{{*/ +// --------------------------------------------------------------------- +/* a small wrapper around CreateDirectory to check if it exists and to + remove the trailing "/apt/" from the parent directory if needed */ +bool CreateAPTDirectoryIfNeeded(string const &Parent, string const &Path) +{ + if (DirectoryExists(Path) == true) + return true; + + size_t const len = Parent.size(); + if (len > 5 && Parent.find("/apt/", len - 6, 5) == len - 5) + { + if (CreateDirectory(Parent.substr(0,len-5), Path) == true) + return true; + } + else if (CreateDirectory(Parent, Path) == true) + return true; + + return false; +} + /*}}}*/ +// GetListOfFilesInDir - returns a vector of files in the given dir /*{{{*/ +// --------------------------------------------------------------------- +/* If an extension is given only files with this extension are included + in the returned vector, otherwise every "normal" file is included. */ +std::vector<string> GetListOfFilesInDir(string const &Dir, string const &Ext, + bool const &SortList, bool const &AllowNoExt) +{ + std::vector<string> ext; + ext.reserve(2); + if (Ext.empty() == false) + ext.push_back(Ext); + if (AllowNoExt == true && ext.empty() == false) + ext.push_back(""); + return GetListOfFilesInDir(Dir, ext, SortList); +} +std::vector<string> GetListOfFilesInDir(string const &Dir, std::vector<string> const &Ext, + bool const &SortList) +{ + // Attention debuggers: need to be set with the environment config file! + bool const Debug = _config->FindB("Debug::GetListOfFilesInDir", false); + if (Debug == true) + { + std::clog << "Accept in " << Dir << " only files with the following " << Ext.size() << " extensions:" << std::endl; + if (Ext.empty() == true) + std::clog << "\tNO extension" << std::endl; + else + for (std::vector<string>::const_iterator e = Ext.begin(); + e != Ext.end(); ++e) + std::clog << '\t' << (e->empty() == true ? "NO" : *e) << " extension" << std::endl; + } + + std::vector<string> List; + + if (DirectoryExists(Dir) == false) + { + _error->Error(_("List of files can't be created as '%s' is not a directory"), Dir.c_str()); + return List; + } + + Configuration::MatchAgainstConfig SilentIgnore("Dir::Ignore-Files-Silently"); + DIR *D = opendir(Dir.c_str()); + if (D == 0) + { + if (errno == EACCES) + _error->WarningE("opendir", _("Unable to read %s"), Dir.c_str()); + else + _error->Errno("opendir", _("Unable to read %s"), Dir.c_str()); + return List; + } + + for (struct dirent *Ent = readdir(D); Ent != 0; Ent = readdir(D)) + { + // skip "hidden" files + if (Ent->d_name[0] == '.') + continue; + + // Make sure it is a file and not something else + string const File = flCombine(Dir,Ent->d_name); +#ifdef _DIRENT_HAVE_D_TYPE + if (Ent->d_type != DT_REG) +#endif + { + if (RealFileExists(File) == false) + { + // do not show ignoration warnings for directories + if ( +#ifdef _DIRENT_HAVE_D_TYPE + Ent->d_type == DT_DIR || +#endif + DirectoryExists(File) == true) + continue; + if (SilentIgnore.Match(Ent->d_name) == false) + _error->Notice(_("Ignoring '%s' in directory '%s' as it is not a regular file"), Ent->d_name, Dir.c_str()); + continue; + } + } + + // check for accepted extension: + // no extension given -> periods are bad as hell! + // extensions given -> "" extension allows no extension + if (Ext.empty() == false) + { + string d_ext = flExtension(Ent->d_name); + if (d_ext == Ent->d_name) // no extension + { + if (std::find(Ext.begin(), Ext.end(), "") == Ext.end()) + { + if (Debug == true) + std::clog << "Bad file: " << Ent->d_name << " → no extension" << std::endl; + if (SilentIgnore.Match(Ent->d_name) == false) + _error->Notice(_("Ignoring file '%s' in directory '%s' as it has no filename extension"), Ent->d_name, Dir.c_str()); + continue; + } + } + else if (std::find(Ext.begin(), Ext.end(), d_ext) == Ext.end()) + { + if (Debug == true) + std::clog << "Bad file: " << Ent->d_name << " → bad extension »" << flExtension(Ent->d_name) << "«" << std::endl; + if (SilentIgnore.Match(Ent->d_name) == false) + _error->Notice(_("Ignoring file '%s' in directory '%s' as it has an invalid filename extension"), Ent->d_name, Dir.c_str()); + continue; + } + } + + // Skip bad filenames ala run-parts + const char *C = Ent->d_name; + for (; *C != 0; ++C) + if (isalpha(*C) == 0 && isdigit(*C) == 0 + && *C != '_' && *C != '-' && *C != ':') { + // no required extension -> dot is a bad character + if (*C == '.' && Ext.empty() == false) + continue; + break; + } + + // we don't reach the end of the name -> bad character included + if (*C != 0) + { + if (Debug == true) + std::clog << "Bad file: " << Ent->d_name << " → bad character »" + << *C << "« in filename (period allowed: " << (Ext.empty() ? "no" : "yes") << ")" << std::endl; + continue; + } + + // skip filenames which end with a period. These are never valid + if (*(C - 1) == '.') + { + if (Debug == true) + std::clog << "Bad file: " << Ent->d_name << " → Period as last character" << std::endl; + continue; + } + + if (Debug == true) + std::clog << "Accept file: " << Ent->d_name << " in " << Dir << std::endl; + List.push_back(File); + } + closedir(D); + + if (SortList == true) + std::sort(List.begin(),List.end()); + return List; +} +std::vector<string> GetListOfFilesInDir(string const &Dir, bool SortList) +{ + bool const Debug = _config->FindB("Debug::GetListOfFilesInDir", false); + if (Debug == true) + std::clog << "Accept in " << Dir << " all regular files" << std::endl; + + std::vector<string> List; + + if (DirectoryExists(Dir) == false) + { + _error->Error(_("List of files can't be created as '%s' is not a directory"), Dir.c_str()); + return List; + } + + DIR *D = opendir(Dir.c_str()); + if (D == 0) + { + _error->Errno("opendir",_("Unable to read %s"),Dir.c_str()); + return List; + } + + for (struct dirent *Ent = readdir(D); Ent != 0; Ent = readdir(D)) + { + // skip "hidden" files + if (Ent->d_name[0] == '.') + continue; + + // Make sure it is a file and not something else + string const File = flCombine(Dir,Ent->d_name); +#ifdef _DIRENT_HAVE_D_TYPE + if (Ent->d_type != DT_REG) +#endif + { + if (RealFileExists(File) == false) + { + if (Debug == true) + std::clog << "Bad file: " << Ent->d_name << " → it is not a real file" << std::endl; + continue; + } + } + + // Skip bad filenames ala run-parts + const char *C = Ent->d_name; + for (; *C != 0; ++C) + if (isalpha(*C) == 0 && isdigit(*C) == 0 + && *C != '_' && *C != '-' && *C != '.') + break; + + // we don't reach the end of the name -> bad character included + if (*C != 0) + { + if (Debug == true) + std::clog << "Bad file: " << Ent->d_name << " → bad character »" << *C << "« in filename" << std::endl; + continue; + } + + // skip filenames which end with a period. These are never valid + if (*(C - 1) == '.') + { + if (Debug == true) + std::clog << "Bad file: " << Ent->d_name << " → Period as last character" << std::endl; + continue; + } + + if (Debug == true) + std::clog << "Accept file: " << Ent->d_name << " in " << Dir << std::endl; + List.push_back(File); + } + closedir(D); + + if (SortList == true) + std::sort(List.begin(),List.end()); + return List; +} + /*}}}*/ +// SafeGetCWD - This is a safer getcwd that returns a dynamic string /*{{{*/ +// --------------------------------------------------------------------- +/* We return / on failure. */ +string SafeGetCWD() +{ + // Stash the current dir. + char S[300]; + S[0] = 0; + if (getcwd(S,sizeof(S)-2) == 0) + return "/"; + unsigned int Len = strlen(S); + S[Len] = '/'; + S[Len+1] = 0; + return S; +} + /*}}}*/ +// GetModificationTime - Get the mtime of the given file or -1 on error /*{{{*/ +// --------------------------------------------------------------------- +/* We return / on failure. */ +time_t GetModificationTime(string const &Path) +{ + struct stat St; + if (stat(Path.c_str(), &St) < 0) + return -1; + return St.st_mtime; +} + /*}}}*/ +// flNotDir - Strip the directory from the filename /*{{{*/ +// --------------------------------------------------------------------- +/* */ +string flNotDir(string File) +{ + string::size_type Res = File.rfind('/'); + if (Res == string::npos) + return File; + Res++; + return string(File,Res,Res - File.length()); +} + /*}}}*/ +// flNotFile - Strip the file from the directory name /*{{{*/ +// --------------------------------------------------------------------- +/* Result ends in a / */ +string flNotFile(string File) +{ + string::size_type Res = File.rfind('/'); + if (Res == string::npos) + return "./"; + Res++; + return string(File,0,Res); +} + /*}}}*/ +// flExtension - Return the extension for the file /*{{{*/ +// --------------------------------------------------------------------- +/* */ +string flExtension(string File) +{ + string::size_type Res = File.rfind('.'); + if (Res == string::npos) + return File; + Res++; + return string(File,Res,Res - File.length()); +} + /*}}}*/ +// flNoLink - If file is a symlink then deref it /*{{{*/ +// --------------------------------------------------------------------- +/* If the name is not a link then the returned path is the input. */ +string flNoLink(string File) +{ + struct stat St; + if (lstat(File.c_str(),&St) != 0 || S_ISLNK(St.st_mode) == 0) + return File; + if (stat(File.c_str(),&St) != 0) + return File; + + /* Loop resolving the link. There is no need to limit the number of + loops because the stat call above ensures that the symlink is not + circular */ + char Buffer[1024]; + string NFile = File; + while (1) + { + // Read the link + ssize_t Res; + if ((Res = readlink(NFile.c_str(),Buffer,sizeof(Buffer))) <= 0 || + (size_t)Res >= sizeof(Buffer)) + return File; + + // Append or replace the previous path + Buffer[Res] = 0; + if (Buffer[0] == '/') + NFile = Buffer; + else + NFile = flNotFile(NFile) + Buffer; + + // See if we are done + if (lstat(NFile.c_str(),&St) != 0) + return File; + if (S_ISLNK(St.st_mode) == 0) + return NFile; + } +} + /*}}}*/ +// flCombine - Combine a file and a directory /*{{{*/ +// --------------------------------------------------------------------- +/* If the file is an absolute path then it is just returned, otherwise + the directory is pre-pended to it. */ +string flCombine(string Dir,string File) +{ + if (File.empty() == true) + return string(); + + if (File[0] == '/' || Dir.empty() == true) + return File; + if (File.length() >= 2 && File[0] == '.' && File[1] == '/') + return File; + if (Dir[Dir.length()-1] == '/') + return Dir + File; + return Dir + '/' + File; +} + /*}}}*/ +// flAbsPath - Return the absolute path of the filename /*{{{*/ +// --------------------------------------------------------------------- +/* */ +string flAbsPath(string File) +{ + char *p = realpath(File.c_str(), NULL); + if (p == NULL) + { + _error->Errno("realpath", "flAbsPath on %s failed", File.c_str()); + return ""; + } + std::string AbsPath(p); + free(p); + return AbsPath; +} + /*}}}*/ +std::string flNormalize(std::string file) /*{{{*/ +{ + if (file.empty()) + return file; + // do some normalisation by removing // and /./ from the path + size_t found = string::npos; + while ((found = file.find("/./")) != string::npos) + file.replace(found, 3, "/"); + while ((found = file.find("//")) != string::npos) + file.replace(found, 2, "/"); + + if (APT::String::Startswith(file, "/dev/null")) + { + file.erase(strlen("/dev/null")); + return file; + } + return file; +} + /*}}}*/ +// SetCloseExec - Set the close on exec flag /*{{{*/ +// --------------------------------------------------------------------- +/* */ +void SetCloseExec(int Fd,bool Close) +{ + if (fcntl(Fd,F_SETFD,(Close == false)?0:FD_CLOEXEC) != 0) + { + cerr << "FATAL -> Could not set close on exec " << strerror(errno) << endl; + exit(100); + } +} + /*}}}*/ +// SetNonBlock - Set the nonblocking flag /*{{{*/ +// --------------------------------------------------------------------- +/* */ +void SetNonBlock(int Fd,bool Block) +{ + int Flags = fcntl(Fd,F_GETFL) & (~O_NONBLOCK); + if (fcntl(Fd,F_SETFL,Flags | ((Block == false)?0:O_NONBLOCK)) != 0) + { + cerr << "FATAL -> Could not set non-blocking flag " << strerror(errno) << endl; + exit(100); + } +} + /*}}}*/ +// WaitFd - Wait for a FD to become readable /*{{{*/ +// --------------------------------------------------------------------- +/* This waits for a FD to become readable using select. It is useful for + applications making use of non-blocking sockets. The timeout is + in seconds. */ +bool WaitFd(int Fd,bool write,unsigned long timeout) +{ + fd_set Set; + struct timeval tv; + FD_ZERO(&Set); + FD_SET(Fd,&Set); + tv.tv_sec = timeout; + tv.tv_usec = 0; + if (write == true) + { + int Res; + do + { + Res = select(Fd+1,0,&Set,0,(timeout != 0?&tv:0)); + } + while (Res < 0 && errno == EINTR); + + if (Res <= 0) + return false; + } + else + { + int Res; + do + { + Res = select(Fd+1,&Set,0,0,(timeout != 0?&tv:0)); + } + while (Res < 0 && errno == EINTR); + + if (Res <= 0) + return false; + } + + return true; +} + /*}}}*/ +// MergeKeepFdsFromConfiguration - Merge APT::Keep-Fds configuration /*{{{*/ +// --------------------------------------------------------------------- +/* This is used to merge the APT::Keep-Fds with the provided KeepFDs + * set. + */ +void MergeKeepFdsFromConfiguration(std::set<int> &KeepFDs) +{ + Configuration::Item const *Opts = _config->Tree("APT::Keep-Fds"); + if (Opts != 0 && Opts->Child != 0) + { + Opts = Opts->Child; + for (; Opts != 0; Opts = Opts->Next) + { + if (Opts->Value.empty() == true) + continue; + int fd = atoi(Opts->Value.c_str()); + KeepFDs.insert(fd); + } + } +} + /*}}}*/ +// ExecFork - Magical fork that sanitizes the context before execing /*{{{*/ +// --------------------------------------------------------------------- +/* This is used if you want to cleanse the environment for the forked + child, it fixes up the important signals and nukes all of the fds, + otherwise acts like normal fork. */ +pid_t ExecFork() +{ + set<int> KeepFDs; + // we need to merge the Keep-Fds as external tools like + // debconf-apt-progress use it + MergeKeepFdsFromConfiguration(KeepFDs); + return ExecFork(KeepFDs); +} + +pid_t ExecFork(std::set<int> KeepFDs) +{ + // Fork off the process + pid_t Process = fork(); + if (Process < 0) + { + cerr << "FATAL -> Failed to fork." << endl; + exit(100); + } + + // Spawn the subprocess + if (Process == 0) + { + // Setup the signals + signal(SIGPIPE,SIG_DFL); + signal(SIGQUIT,SIG_DFL); + signal(SIGINT,SIG_DFL); + signal(SIGWINCH,SIG_DFL); + signal(SIGCONT,SIG_DFL); + signal(SIGTSTP,SIG_DFL); + + DIR *dir = opendir("/proc/self/fd"); + if (dir != NULL) + { + struct dirent *ent; + while ((ent = readdir(dir))) + { + int fd = atoi(ent->d_name); + // If fd > 0, it was a fd number and not . or .. + if (fd >= 3 && KeepFDs.find(fd) == KeepFDs.end()) + fcntl(fd,F_SETFD,FD_CLOEXEC); + } + closedir(dir); + } else { + long ScOpenMax = sysconf(_SC_OPEN_MAX); + // Close all of our FDs - just in case + for (int K = 3; K != ScOpenMax; K++) + { + if(KeepFDs.find(K) == KeepFDs.end()) + fcntl(K,F_SETFD,FD_CLOEXEC); + } + } + } + + return Process; +} + /*}}}*/ +// ExecWait - Fancy waitpid /*{{{*/ +// --------------------------------------------------------------------- +/* Waits for the given sub process. If Reap is set then no errors are + generated. Otherwise a failed subprocess will generate a proper descriptive + message */ +bool ExecWait(pid_t Pid,const char *Name,bool Reap) +{ + if (Pid <= 1) + return true; + + // Wait and collect the error code + int Status; + while (waitpid(Pid,&Status,0) != Pid) + { + if (errno == EINTR) + continue; + + if (Reap == true) + return false; + + return _error->Error(_("Waited for %s but it wasn't there"),Name); + } + + + // Check for an error code. + if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0) + { + if (Reap == true) + return false; + if (WIFSIGNALED(Status) != 0) + { + if( WTERMSIG(Status) == SIGSEGV) + return _error->Error(_("Sub-process %s received a segmentation fault."),Name); + else + return _error->Error(_("Sub-process %s received signal %u."),Name, WTERMSIG(Status)); + } + + if (WIFEXITED(Status) != 0) + return _error->Error(_("Sub-process %s returned an error code (%u)"),Name,WEXITSTATUS(Status)); + + return _error->Error(_("Sub-process %s exited unexpectedly"),Name); + } + + return true; +} + /*}}}*/ +// StartsWithGPGClearTextSignature - Check if a file is Pgp/GPG clearsigned /*{{{*/ +bool StartsWithGPGClearTextSignature(string const &FileName) +{ + FILE* gpg = fopen(FileName.c_str(), "r"); + if (gpg == nullptr) + return false; + + char * lineptr = nullptr; + size_t n = 0; + errno = 0; + ssize_t const result = getline(&lineptr, &n, gpg); + if (errno != 0) + { + _error->Errno("getline", "Could not read from %s", FileName.c_str()); + fclose(gpg); + free(lineptr); + return false; + } + fclose(gpg); + + _strrstrip(lineptr); + static const char* SIGMSG = "-----BEGIN PGP SIGNED MESSAGE-----"; + if (result == -1 || strcmp(lineptr, SIGMSG) != 0) + { + free(lineptr); + return false; + } + free(lineptr); + return true; +} + /*}}}*/ +// ChangeOwnerAndPermissionOfFile - set file attributes to requested values /*{{{*/ +bool ChangeOwnerAndPermissionOfFile(char const * const requester, char const * const file, char const * const user, char const * const group, mode_t const mode) +{ + if (strcmp(file, "/dev/null") == 0) + return true; + bool Res = true; + if (getuid() == 0 && strlen(user) != 0 && strlen(group) != 0) // if we aren't root, we can't chown, so don't try it + { + // ensure the file is owned by root and has good permissions + struct passwd const * const pw = getpwnam(user); + struct group const * const gr = getgrnam(group); + if (pw != NULL && gr != NULL && lchown(file, pw->pw_uid, gr->gr_gid) != 0) + Res &= _error->WarningE(requester, "chown to %s:%s of file %s failed", user, group, file); + } + struct stat Buf; + if (lstat(file, &Buf) != 0 || S_ISLNK(Buf.st_mode)) + return Res; + if (chmod(file, mode) != 0) + Res &= _error->WarningE(requester, "chmod 0%o of file %s failed", mode, file); + return Res; +} + /*}}}*/ + +struct APT_HIDDEN simple_buffer { /*{{{*/ + size_t buffersize_max = 0; + unsigned long long bufferstart = 0; + unsigned long long bufferend = 0; + char *buffer = nullptr; + + simple_buffer() { + reset(4096); + } + ~simple_buffer() { + delete[] buffer; + } + + const char *get() const { return buffer + bufferstart; } + char *get() { return buffer + bufferstart; } + const char *getend() const { return buffer + bufferend; } + char *getend() { return buffer + bufferend; } + bool empty() const { return bufferend <= bufferstart; } + bool full() const { return bufferend == buffersize_max; } + unsigned long long free() const { return buffersize_max - bufferend; } + unsigned long long size() const { return bufferend-bufferstart; } + void reset(size_t size) + { + if (size > buffersize_max) { + delete[] buffer; + buffersize_max = size; + buffer = new char[size]; + } + reset(); + } + void reset() { bufferend = bufferstart = 0; } + ssize_t read(void *to, unsigned long long requested_size) APT_MUSTCHECK + { + if (size() < requested_size) + requested_size = size(); + memcpy(to, buffer + bufferstart, requested_size); + bufferstart += requested_size; + if (bufferstart == bufferend) + bufferstart = bufferend = 0; + return requested_size; + } + ssize_t write(const void *from, unsigned long long requested_size) APT_MUSTCHECK + { + if (free() < requested_size) + requested_size = free(); + memcpy(getend(), from, requested_size); + bufferend += requested_size; + if (bufferstart == bufferend) + bufferstart = bufferend = 0; + return requested_size; + } +}; + /*}}}*/ + +class APT_HIDDEN FileFdPrivate { /*{{{*/ + friend class BufferedWriteFileFdPrivate; +protected: + FileFd * const filefd; + simple_buffer buffer; + int compressed_fd; + pid_t compressor_pid; + bool is_pipe; + APT::Configuration::Compressor compressor; + unsigned int openmode; + unsigned long long seekpos; +public: + + explicit FileFdPrivate(FileFd * const pfilefd) : filefd(pfilefd), + compressed_fd(-1), compressor_pid(-1), is_pipe(false), + openmode(0), seekpos(0) {}; + virtual APT::Configuration::Compressor get_compressor() const + { + return compressor; + } + virtual void set_compressor(APT::Configuration::Compressor const &compressor) + { + this->compressor = compressor; + } + virtual unsigned int get_openmode() const + { + return openmode; + } + virtual void set_openmode(unsigned int openmode) + { + this->openmode = openmode; + } + virtual bool get_is_pipe() const + { + return is_pipe; + } + virtual void set_is_pipe(bool is_pipe) + { + this->is_pipe = is_pipe; + } + virtual unsigned long long get_seekpos() const + { + return seekpos; + } + virtual void set_seekpos(unsigned long long seekpos) + { + this->seekpos = seekpos; + } + + virtual bool InternalOpen(int const iFd, unsigned int const Mode) = 0; + ssize_t InternalRead(void * To, unsigned long long Size) + { + // Drain the buffer if needed. + if (buffer.empty() == false) + { + return buffer.read(To, Size); + } + return InternalUnbufferedRead(To, Size); + } + virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) = 0; + virtual bool InternalReadError() { return filefd->FileFdErrno("read",_("Read error")); } + virtual char * InternalReadLine(char * To, unsigned long long Size) + { + if (unlikely(Size == 0)) + return nullptr; + // Read one byte less than buffer size to have space for trailing 0. + --Size; + + char * const InitialTo = To; + + while (Size > 0) { + if (buffer.empty() == true) + { + buffer.reset(); + unsigned long long actualread = 0; + if (filefd->Read(buffer.getend(), buffer.free(), &actualread) == false) + return nullptr; + buffer.bufferend = actualread; + if (buffer.size() == 0) + { + if (To == InitialTo) + return nullptr; + break; + } + filefd->Flags &= ~FileFd::HitEof; + } + + unsigned long long const OutputSize = std::min(Size, buffer.size()); + char const * const newline = static_cast<char const *>(memchr(buffer.get(), '\n', OutputSize)); + // Read until end of line or up to Size bytes from the buffer. + unsigned long long actualread = buffer.read(To, + (newline != nullptr) + ? (newline - buffer.get()) + 1 + : OutputSize); + To += actualread; + Size -= actualread; + if (newline != nullptr) + break; + } + *To = '\0'; + return InitialTo; + } + virtual bool InternalFlush() + { + return true; + } + virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) = 0; + virtual bool InternalWriteError() { return filefd->FileFdErrno("write",_("Write error")); } + virtual bool InternalSeek(unsigned long long const To) + { + // Our poor man seeking is costly, so try to avoid it + unsigned long long const iseekpos = filefd->Tell(); + if (iseekpos == To) + return true; + else if (iseekpos < To) + return filefd->Skip(To - iseekpos); + + if ((openmode & FileFd::ReadOnly) != FileFd::ReadOnly) + return filefd->FileFdError("Reopen is only implemented for read-only files!"); + InternalClose(filefd->FileName); + if (filefd->iFd != -1) + close(filefd->iFd); + filefd->iFd = -1; + if (filefd->TemporaryFileName.empty() == false) + filefd->iFd = open(filefd->TemporaryFileName.c_str(), O_RDONLY); + else if (filefd->FileName.empty() == false) + filefd->iFd = open(filefd->FileName.c_str(), O_RDONLY); + else + { + if (compressed_fd > 0) + if (lseek(compressed_fd, 0, SEEK_SET) != 0) + filefd->iFd = compressed_fd; + if (filefd->iFd < 0) + return filefd->FileFdError("Reopen is not implemented for pipes opened with FileFd::OpenDescriptor()!"); + } + + if (filefd->OpenInternDescriptor(openmode, compressor) == false) + return filefd->FileFdError("Seek on file %s because it couldn't be reopened", filefd->FileName.c_str()); + + buffer.reset(); + set_seekpos(0); + if (To != 0) + return filefd->Skip(To); + + seekpos = To; + return true; + } + virtual bool InternalSkip(unsigned long long Over) + { + unsigned long long constexpr buffersize = 1024; + char buffer[buffersize]; + while (Over != 0) + { + unsigned long long toread = std::min(buffersize, Over); + if (filefd->Read(buffer, toread) == false) + return filefd->FileFdError("Unable to seek ahead %llu",Over); + Over -= toread; + } + return true; + } + virtual bool InternalTruncate(unsigned long long const) + { + return filefd->FileFdError("Truncating compressed files is not implemented (%s)", filefd->FileName.c_str()); + } + virtual unsigned long long InternalTell() + { + // In theory, we could just return seekpos here always instead of + // seeking around, but not all users of FileFd use always Seek() and co + // so d->seekpos isn't always true and we can just use it as a hint if + // we have nothing else, but not always as an authority… + return seekpos - buffer.size(); + } + virtual unsigned long long InternalSize() + { + unsigned long long size = 0; + unsigned long long const oldSeek = filefd->Tell(); + unsigned long long constexpr ignoresize = 1024; + char ignore[ignoresize]; + unsigned long long read = 0; + do { + if (filefd->Read(ignore, ignoresize, &read) == false) + { + filefd->Seek(oldSeek); + return 0; + } + } while(read != 0); + size = filefd->Tell(); + filefd->Seek(oldSeek); + return size; + } + virtual bool InternalClose(std::string const &FileName) = 0; + virtual bool InternalStream() const { return false; } + virtual bool InternalAlwaysAutoClose() const { return true; } + + virtual ~FileFdPrivate() {} +}; + /*}}}*/ +class APT_HIDDEN BufferedWriteFileFdPrivate : public FileFdPrivate { /*{{{*/ +protected: + FileFdPrivate *wrapped; + simple_buffer writebuffer; + +public: + + explicit BufferedWriteFileFdPrivate(FileFdPrivate *Priv) : + FileFdPrivate(Priv->filefd), wrapped(Priv) {}; + + virtual APT::Configuration::Compressor get_compressor() const APT_OVERRIDE + { + return wrapped->get_compressor(); + } + virtual void set_compressor(APT::Configuration::Compressor const &compressor) APT_OVERRIDE + { + return wrapped->set_compressor(compressor); + } + virtual unsigned int get_openmode() const APT_OVERRIDE + { + return wrapped->get_openmode(); + } + virtual void set_openmode(unsigned int openmode) APT_OVERRIDE + { + return wrapped->set_openmode(openmode); + } + virtual bool get_is_pipe() const APT_OVERRIDE + { + return wrapped->get_is_pipe(); + } + virtual void set_is_pipe(bool is_pipe) APT_OVERRIDE + { + FileFdPrivate::set_is_pipe(is_pipe); + wrapped->set_is_pipe(is_pipe); + } + virtual unsigned long long get_seekpos() const APT_OVERRIDE + { + return wrapped->get_seekpos(); + } + virtual void set_seekpos(unsigned long long seekpos) APT_OVERRIDE + { + return wrapped->set_seekpos(seekpos); + } + virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE + { + if (InternalFlush() == false) + return false; + return wrapped->InternalOpen(iFd, Mode); + } + virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE + { + if (InternalFlush() == false) + return -1; + return wrapped->InternalUnbufferedRead(To, Size); + + } + virtual bool InternalReadError() APT_OVERRIDE + { + return wrapped->InternalReadError(); + } + virtual char * InternalReadLine(char * To, unsigned long long Size) APT_OVERRIDE + { + if (InternalFlush() == false) + return nullptr; + return wrapped->InternalReadLine(To, Size); + } + virtual bool InternalFlush() APT_OVERRIDE + { + while (writebuffer.empty() == false) { + auto written = wrapped->InternalWrite(writebuffer.get(), + writebuffer.size()); + // Ignore interrupted syscalls + if (written < 0 && errno == EINTR) + continue; + if (written < 0) + return wrapped->InternalWriteError(); + + writebuffer.bufferstart += written; + } + writebuffer.reset(); + return wrapped->InternalFlush(); + } + virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE + { + // Optimisation: If the buffer is empty and we have more to write than + // would fit in the buffer (or equal number of bytes), write directly. + if (writebuffer.empty() == true && Size >= writebuffer.free()) + return wrapped->InternalWrite(From, Size); + + // Write as much into the buffer as possible and then flush if needed + auto written = writebuffer.write(From, Size); + + if (writebuffer.full() && InternalFlush() == false) + return -1; + + return written; + } + virtual bool InternalWriteError() APT_OVERRIDE + { + return wrapped->InternalWriteError(); + } + virtual bool InternalSeek(unsigned long long const To) APT_OVERRIDE + { + if (InternalFlush() == false) + return false; + return wrapped->InternalSeek(To); + } + virtual bool InternalSkip(unsigned long long Over) APT_OVERRIDE + { + if (InternalFlush() == false) + return false; + return wrapped->InternalSkip(Over); + } + virtual bool InternalTruncate(unsigned long long const Size) APT_OVERRIDE + { + if (InternalFlush() == false) + return false; + return wrapped->InternalTruncate(Size); + } + virtual unsigned long long InternalTell() APT_OVERRIDE + { + if (InternalFlush() == false) + return -1; + return wrapped->InternalTell(); + } + virtual unsigned long long InternalSize() APT_OVERRIDE + { + if (InternalFlush() == false) + return -1; + return wrapped->InternalSize(); + } + virtual bool InternalClose(std::string const &FileName) APT_OVERRIDE + { + return wrapped->InternalClose(FileName); + } + virtual bool InternalAlwaysAutoClose() const APT_OVERRIDE + { + return wrapped->InternalAlwaysAutoClose(); + } + virtual ~BufferedWriteFileFdPrivate() + { + delete wrapped; + } +}; + /*}}}*/ +class APT_HIDDEN GzipFileFdPrivate: public FileFdPrivate { /*{{{*/ +#ifdef HAVE_ZLIB +public: + gzFile gz; + virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE + { + if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite) + gz = gzdopen(iFd, "r+"); + else if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly) + gz = gzdopen(iFd, "w"); + else + gz = gzdopen(iFd, "r"); + filefd->Flags |= FileFd::Compressed; + return gz != nullptr; + } + virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE + { + return gzread(gz, To, Size); + } + virtual bool InternalReadError() APT_OVERRIDE + { + int err; + char const * const errmsg = gzerror(gz, &err); + if (err != Z_ERRNO) + return filefd->FileFdError("gzread: %s (%d: %s)", _("Read error"), err, errmsg); + return FileFdPrivate::InternalReadError(); + } + virtual char * InternalReadLine(char * To, unsigned long long Size) APT_OVERRIDE + { + return gzgets(gz, To, Size); + } + virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE + { + return gzwrite(gz,From,Size); + } + virtual bool InternalWriteError() APT_OVERRIDE + { + int err; + char const * const errmsg = gzerror(gz, &err); + if (err != Z_ERRNO) + return filefd->FileFdError("gzwrite: %s (%d: %s)", _("Write error"), err, errmsg); + return FileFdPrivate::InternalWriteError(); + } + virtual bool InternalSeek(unsigned long long const To) APT_OVERRIDE + { + off_t const res = gzseek(gz, To, SEEK_SET); + if (res != (off_t)To) + return filefd->FileFdError("Unable to seek to %llu", To); + seekpos = To; + buffer.reset(); + return true; + } + virtual bool InternalSkip(unsigned long long Over) APT_OVERRIDE + { + if (Over >= buffer.size()) + { + Over -= buffer.size(); + buffer.reset(); + } + else + { + buffer.bufferstart += Over; + return true; + } + if (Over == 0) + return true; + off_t const res = gzseek(gz, Over, SEEK_CUR); + if (res < 0) + return filefd->FileFdError("Unable to seek ahead %llu",Over); + seekpos = res; + return true; + } + virtual unsigned long long InternalTell() APT_OVERRIDE + { + return gztell(gz) - buffer.size(); + } + virtual unsigned long long InternalSize() APT_OVERRIDE + { + unsigned long long filesize = FileFdPrivate::InternalSize(); + // only check gzsize if we are actually a gzip file, just checking for + // "gz" is not sufficient as uncompressed files could be opened with + // gzopen in "direct" mode as well + if (filesize == 0 || gzdirect(gz)) + return filesize; + + off_t const oldPos = lseek(filefd->iFd, 0, SEEK_CUR); + /* unfortunately zlib.h doesn't provide a gzsize(), so we have to do + * this ourselves; the original (uncompressed) file size is the last 32 + * bits of the file */ + // FIXME: Size for gz-files is limited by 32bit… no largefile support + if (lseek(filefd->iFd, -4, SEEK_END) < 0) + { + filefd->FileFdErrno("lseek","Unable to seek to end of gzipped file"); + return 0; + } + uint32_t size = 0; + if (read(filefd->iFd, &size, 4) != 4) + { + filefd->FileFdErrno("read","Unable to read original size of gzipped file"); + return 0; + } + size = le32toh(size); + + if (lseek(filefd->iFd, oldPos, SEEK_SET) < 0) + { + filefd->FileFdErrno("lseek","Unable to seek in gzipped file"); + return 0; + } + return size; + } + virtual bool InternalClose(std::string const &FileName) APT_OVERRIDE + { + if (gz == nullptr) + return true; + int const e = gzclose(gz); + gz = nullptr; + // gzdclose() on empty files always fails with "buffer error" here, ignore that + if (e != 0 && e != Z_BUF_ERROR) + return _error->Errno("close",_("Problem closing the gzip file %s"), FileName.c_str()); + return true; + } + + explicit GzipFileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd), gz(nullptr) {} + virtual ~GzipFileFdPrivate() { InternalClose(""); } +#endif +}; + /*}}}*/ +class APT_HIDDEN Bz2FileFdPrivate: public FileFdPrivate { /*{{{*/ +#ifdef HAVE_BZ2 + BZFILE* bz2; +public: + virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE + { + if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite) + bz2 = BZ2_bzdopen(iFd, "r+"); + else if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly) + bz2 = BZ2_bzdopen(iFd, "w"); + else + bz2 = BZ2_bzdopen(iFd, "r"); + filefd->Flags |= FileFd::Compressed; + return bz2 != nullptr; + } + virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE + { + return BZ2_bzread(bz2, To, Size); + } + virtual bool InternalReadError() APT_OVERRIDE + { + int err; + char const * const errmsg = BZ2_bzerror(bz2, &err); + if (err != BZ_IO_ERROR) + return filefd->FileFdError("BZ2_bzread: %s %s (%d: %s)", filefd->FileName.c_str(), _("Read error"), err, errmsg); + return FileFdPrivate::InternalReadError(); + } + virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE + { + return BZ2_bzwrite(bz2, (void*)From, Size); + } + virtual bool InternalWriteError() APT_OVERRIDE + { + int err; + char const * const errmsg = BZ2_bzerror(bz2, &err); + if (err != BZ_IO_ERROR) + return filefd->FileFdError("BZ2_bzwrite: %s %s (%d: %s)", filefd->FileName.c_str(), _("Write error"), err, errmsg); + return FileFdPrivate::InternalWriteError(); + } + virtual bool InternalStream() const APT_OVERRIDE { return true; } + virtual bool InternalClose(std::string const &) APT_OVERRIDE + { + if (bz2 == nullptr) + return true; + BZ2_bzclose(bz2); + bz2 = nullptr; + return true; + } + + explicit Bz2FileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd), bz2(nullptr) {} + virtual ~Bz2FileFdPrivate() { InternalClose(""); } +#endif +}; + /*}}}*/ +class APT_HIDDEN Lz4FileFdPrivate: public FileFdPrivate { /*{{{*/ + static constexpr unsigned long long LZ4_HEADER_SIZE = 19; + static constexpr unsigned long long LZ4_FOOTER_SIZE = 4; +#ifdef HAVE_LZ4 + LZ4F_decompressionContext_t dctx; + LZ4F_compressionContext_t cctx; + LZ4F_errorCode_t res; + FileFd backend; + simple_buffer lz4_buffer; + // Count of bytes that the decompressor expects to read next, or buffer size. + size_t next_to_load = APT_BUFFER_SIZE; +public: + virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE + { + if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite) + return _error->Error("lz4 only supports write or read mode"); + + if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly) { + res = LZ4F_createCompressionContext(&cctx, LZ4F_VERSION); + lz4_buffer.reset(LZ4F_compressBound(APT_BUFFER_SIZE, nullptr) + + LZ4_HEADER_SIZE + LZ4_FOOTER_SIZE); + } else { + res = LZ4F_createDecompressionContext(&dctx, LZ4F_VERSION); + lz4_buffer.reset(APT_BUFFER_SIZE); + } + + filefd->Flags |= FileFd::Compressed; + + if (LZ4F_isError(res)) + return false; + + unsigned int flags = (Mode & (FileFd::WriteOnly|FileFd::ReadOnly)); + if (backend.OpenDescriptor(iFd, flags, FileFd::None, true) == false) + return false; + + // Write the file header + if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly) + { + res = LZ4F_compressBegin(cctx, lz4_buffer.buffer, lz4_buffer.buffersize_max, nullptr); + if (LZ4F_isError(res) || backend.Write(lz4_buffer.buffer, res) == false) + return false; + } + + return true; + } + virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE + { + /* Keep reading as long as the compressor still wants to read */ + while (next_to_load) { + // Fill compressed buffer; + if (lz4_buffer.empty()) { + unsigned long long read; + /* Reset - if LZ4 decompressor wants to read more, allocate more */ + lz4_buffer.reset(next_to_load); + if (backend.Read(lz4_buffer.getend(), lz4_buffer.free(), &read) == false) + return -1; + lz4_buffer.bufferend += read; + + /* Expected EOF */ + if (read == 0) { + res = -1; + return filefd->FileFdError("LZ4F: %s %s", + filefd->FileName.c_str(), + _("Unexpected end of file")), -1; + } + } + // Drain compressed buffer as far as possible. + size_t in = lz4_buffer.size(); + size_t out = Size; + + res = LZ4F_decompress(dctx, To, &out, lz4_buffer.get(), &in, nullptr); + if (LZ4F_isError(res)) + return -1; + + next_to_load = res; + lz4_buffer.bufferstart += in; + + if (out != 0) + return out; + } + + return 0; + } + virtual bool InternalReadError() APT_OVERRIDE + { + char const * const errmsg = LZ4F_getErrorName(res); + + return filefd->FileFdError("LZ4F: %s %s (%zu: %s)", filefd->FileName.c_str(), _("Read error"), res, errmsg); + } + virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE + { + unsigned long long const towrite = std::min(APT_BUFFER_SIZE, Size); + + res = LZ4F_compressUpdate(cctx, + lz4_buffer.buffer, lz4_buffer.buffersize_max, + From, towrite, nullptr); + + if (LZ4F_isError(res) || backend.Write(lz4_buffer.buffer, res) == false) + return -1; + + return towrite; + } + virtual bool InternalWriteError() APT_OVERRIDE + { + char const * const errmsg = LZ4F_getErrorName(res); + + return filefd->FileFdError("LZ4F: %s %s (%zu: %s)", filefd->FileName.c_str(), _("Write error"), res, errmsg); + } + virtual bool InternalStream() const APT_OVERRIDE { return true; } + + virtual bool InternalFlush() APT_OVERRIDE + { + return backend.Flush(); + } + + virtual bool InternalClose(std::string const &) APT_OVERRIDE + { + /* Reset variables */ + res = 0; + next_to_load = APT_BUFFER_SIZE; + + if (cctx != nullptr) + { + if (filefd->Failed() == false) + { + res = LZ4F_compressEnd(cctx, lz4_buffer.buffer, lz4_buffer.buffersize_max, nullptr); + if (LZ4F_isError(res) || backend.Write(lz4_buffer.buffer, res) == false) + return false; + if (!backend.Flush()) + return false; + } + if (!backend.Close()) + return false; + + res = LZ4F_freeCompressionContext(cctx); + cctx = nullptr; + } + + if (dctx != nullptr) + { + res = LZ4F_freeDecompressionContext(dctx); + dctx = nullptr; + } + if (backend.IsOpen()) + { + backend.Close(); + filefd->iFd = -1; + } + + return LZ4F_isError(res) == false; + } + + explicit Lz4FileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd), dctx(nullptr), cctx(nullptr) {} + virtual ~Lz4FileFdPrivate() { + InternalClose(""); + } +#endif +}; + /*}}}*/ + +class APT_HIDDEN ZstdFileFdPrivate : public FileFdPrivate +{ /*{{{*/ +#ifdef HAVE_ZSTD + ZSTD_DStream *dctx; + ZSTD_CStream *cctx; + size_t res; + FileFd backend; + simple_buffer zstd_buffer; + // Count of bytes that the decompressor expects to read next, or buffer size. + size_t next_to_load = APT_BUFFER_SIZE; + + public: + virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE + { + if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite) + return _error->Error("zstd only supports write or read mode"); + + if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly) + { + cctx = ZSTD_createCStream(); + res = ZSTD_initCStream(cctx, findLevel(compressor.CompressArgs)); + zstd_buffer.reset(APT_BUFFER_SIZE); + } + else + { + dctx = ZSTD_createDStream(); + res = ZSTD_initDStream(dctx); + zstd_buffer.reset(APT_BUFFER_SIZE); + } + + filefd->Flags |= FileFd::Compressed; + + if (ZSTD_isError(res)) + return false; + + unsigned int flags = (Mode & (FileFd::WriteOnly | FileFd::ReadOnly)); + if (backend.OpenDescriptor(iFd, flags, FileFd::None, true) == false) + return false; + + return true; + } + virtual ssize_t InternalUnbufferedRead(void *const To, unsigned long long const Size) APT_OVERRIDE + { + /* Keep reading as long as the compressor still wants to read */ + while (true) + { + // Fill compressed buffer; + if (zstd_buffer.empty()) + { + unsigned long long read; + /* Reset - if LZ4 decompressor wants to read more, allocate more */ + zstd_buffer.reset(next_to_load); + if (backend.Read(zstd_buffer.getend(), zstd_buffer.free(), &read) == false) + return -1; + zstd_buffer.bufferend += read; + + if (read == 0) + { + /* Expected EOF */ + if (next_to_load == 0) + return 0; + + res = -1; + return filefd->FileFdError("ZSTD: %s %s", + filefd->FileName.c_str(), + _("Unexpected end of file")), + -1; + } + } + // Drain compressed buffer as far as possible. + ZSTD_inBuffer in = { + .src = zstd_buffer.get(), + .size = zstd_buffer.size(), + .pos = 0, + }; + ZSTD_outBuffer out = { + .dst = To, + .size = Size, + .pos = 0, + }; + + next_to_load = res = ZSTD_decompressStream(dctx, &out, &in); + + if (res == 0) + { + res = ZSTD_initDStream(dctx); + } + + if (ZSTD_isError(res)) + return -1; + + zstd_buffer.bufferstart += in.pos; + + if (out.pos != 0) + return out.pos; + } + + return 0; + } + virtual bool InternalReadError() APT_OVERRIDE + { + char const *const errmsg = ZSTD_getErrorName(res); + + return filefd->FileFdError("ZSTD: %s %s (%zu: %s)", filefd->FileName.c_str(), _("Read error"), res, errmsg); + } + virtual ssize_t InternalWrite(void const *const From, unsigned long long const Size) APT_OVERRIDE + { + // Drain compressed buffer as far as possible. + ZSTD_outBuffer out = { + .dst = zstd_buffer.buffer, + .size = zstd_buffer.buffersize_max, + .pos = 0, + }; + ZSTD_inBuffer in = { + .src = From, + .size = Size, + .pos = 0, + }; + + res = ZSTD_compressStream(cctx, &out, &in); + + if (ZSTD_isError(res) || backend.Write(zstd_buffer.buffer, out.pos) == false) + return -1; + + return in.pos; + } + + virtual bool InternalWriteError() APT_OVERRIDE + { + char const *const errmsg = ZSTD_getErrorName(res); + + return filefd->FileFdError("ZSTD: %s %s (%zu: %s)", filefd->FileName.c_str(), _("Write error"), res, errmsg); + } + virtual bool InternalStream() const APT_OVERRIDE { return true; } + + virtual bool InternalFlush() APT_OVERRIDE + { + return backend.Flush(); + } + + virtual bool InternalClose(std::string const &) APT_OVERRIDE + { + /* Reset variables */ + res = 0; + next_to_load = APT_BUFFER_SIZE; + + if (cctx != nullptr) + { + if (filefd->Failed() == false) + { + do + { + ZSTD_outBuffer out = { + .dst = zstd_buffer.buffer, + .size = zstd_buffer.buffersize_max, + .pos = 0, + }; + res = ZSTD_endStream(cctx, &out); + if (ZSTD_isError(res) || backend.Write(zstd_buffer.buffer, out.pos) == false) + return false; + } while (res > 0); + + if (!backend.Flush()) + return false; + } + if (!backend.Close()) + return false; + + res = ZSTD_freeCStream(cctx); + cctx = nullptr; + } + + if (dctx != nullptr) + { + res = ZSTD_freeDStream(dctx); + dctx = nullptr; + } + if (backend.IsOpen()) + { + backend.Close(); + filefd->iFd = -1; + } + + return ZSTD_isError(res) == false; + } + + static uint32_t findLevel(std::vector<std::string> const &Args) + { + for (auto a = Args.rbegin(); a != Args.rend(); ++a) + { + if (a->size() >= 2 && (*a)[0] == '-' && (*a)[1] != '-') + { + auto const level = a->substr(1); + auto const notANumber = level.find_first_not_of("0123456789"); + if (notANumber != std::string::npos) + continue; + + return (uint32_t)stoi(level); + } + } + return 19; + } + + explicit ZstdFileFdPrivate(FileFd *const filefd) : FileFdPrivate(filefd), dctx(nullptr), cctx(nullptr) {} + virtual ~ZstdFileFdPrivate() + { + InternalClose(""); + } +#endif +}; + /*}}}*/ +class APT_HIDDEN LzmaFileFdPrivate: public FileFdPrivate { /*{{{*/ +#ifdef HAVE_LZMA + struct LZMAFILE { + FILE* file; + FileFd * const filefd; + uint8_t buffer[4096]; + lzma_stream stream; + lzma_ret err; + bool eof; + bool compressing; + + LZMAFILE(FileFd * const fd) : file(nullptr), filefd(fd), eof(false), compressing(false) { buffer[0] = '\0'; } + ~LZMAFILE() + { + if (compressing == true && filefd->Failed() == false) + { + size_t constexpr buffersize = sizeof(buffer)/sizeof(buffer[0]); + while(true) + { + stream.avail_out = buffersize; + stream.next_out = buffer; + err = lzma_code(&stream, LZMA_FINISH); + if (err != LZMA_OK && err != LZMA_STREAM_END) + { + _error->Error("~LZMAFILE: Compress finalisation failed"); + break; + } + size_t const n = buffersize - stream.avail_out; + if (n && fwrite(buffer, 1, n, file) != n) + { + _error->Errno("~LZMAFILE",_("Write error")); + break; + } + if (err == LZMA_STREAM_END) + break; + } + } + lzma_end(&stream); + fclose(file); + } + }; + LZMAFILE* lzma; + static uint32_t findXZlevel(std::vector<std::string> const &Args) + { + for (auto a = Args.rbegin(); a != Args.rend(); ++a) + if (a->empty() == false && (*a)[0] == '-' && (*a)[1] != '-') + { + auto const number = a->find_last_of("0123456789"); + if (number == std::string::npos) + continue; + auto const extreme = a->find("e", number); + uint32_t level = (extreme != std::string::npos) ? LZMA_PRESET_EXTREME : 0; + switch ((*a)[number]) + { + case '0': return level | 0; + case '1': return level | 1; + case '2': return level | 2; + case '3': return level | 3; + case '4': return level | 4; + case '5': return level | 5; + case '6': return level | 6; + case '7': return level | 7; + case '8': return level | 8; + case '9': return level | 9; + } + } + return 6; + } +public: + virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE + { + if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite) + return filefd->FileFdError("ReadWrite mode is not supported for lzma/xz files %s", filefd->FileName.c_str()); + + if (lzma == nullptr) + lzma = new LzmaFileFdPrivate::LZMAFILE(filefd); + if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly) + lzma->file = fdopen(iFd, "w"); + else + lzma->file = fdopen(iFd, "r"); + filefd->Flags |= FileFd::Compressed; + if (lzma->file == nullptr) + return false; + + lzma_stream tmp_stream = LZMA_STREAM_INIT; + lzma->stream = tmp_stream; + + if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly) + { + uint32_t const xzlevel = findXZlevel(compressor.CompressArgs); + if (compressor.Name == "xz") + { + if (lzma_easy_encoder(&lzma->stream, xzlevel, LZMA_CHECK_CRC64) != LZMA_OK) + return false; + } + else + { + lzma_options_lzma options; + lzma_lzma_preset(&options, xzlevel); + if (lzma_alone_encoder(&lzma->stream, &options) != LZMA_OK) + return false; + } + lzma->compressing = true; + } + else + { + uint64_t const memlimit = UINT64_MAX; + if (compressor.Name == "xz") + { + if (lzma_auto_decoder(&lzma->stream, memlimit, 0) != LZMA_OK) + return false; + } + else + { + if (lzma_alone_decoder(&lzma->stream, memlimit) != LZMA_OK) + return false; + } + lzma->compressing = false; + } + return true; + } + virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE + { + ssize_t Res; + if (lzma->eof == true) + return 0; + + lzma->stream.next_out = (uint8_t *) To; + lzma->stream.avail_out = Size; + if (lzma->stream.avail_in == 0) + { + lzma->stream.next_in = lzma->buffer; + lzma->stream.avail_in = fread(lzma->buffer, 1, sizeof(lzma->buffer)/sizeof(lzma->buffer[0]), lzma->file); + } + lzma->err = lzma_code(&lzma->stream, LZMA_RUN); + if (lzma->err == LZMA_STREAM_END) + { + lzma->eof = true; + Res = Size - lzma->stream.avail_out; + } + else if (lzma->err != LZMA_OK) + { + Res = -1; + errno = 0; + } + else + { + Res = Size - lzma->stream.avail_out; + if (Res == 0) + { + // lzma run was okay, but produced no output… + Res = -1; + errno = EINTR; + } + } + return Res; + } + virtual bool InternalReadError() APT_OVERRIDE + { + return filefd->FileFdError("lzma_read: %s (%d)", _("Read error"), lzma->err); + } + virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE + { + ssize_t Res; + lzma->stream.next_in = (uint8_t *)From; + lzma->stream.avail_in = Size; + lzma->stream.next_out = lzma->buffer; + lzma->stream.avail_out = sizeof(lzma->buffer)/sizeof(lzma->buffer[0]); + lzma->err = lzma_code(&lzma->stream, LZMA_RUN); + if (lzma->err != LZMA_OK) + return -1; + size_t const n = sizeof(lzma->buffer)/sizeof(lzma->buffer[0]) - lzma->stream.avail_out; + size_t const m = (n == 0) ? 0 : fwrite(lzma->buffer, 1, n, lzma->file); + if (m != n) + { + Res = -1; + errno = 0; + } + else + { + Res = Size - lzma->stream.avail_in; + if (Res == 0) + { + // lzma run was okay, but produced no output… + Res = -1; + errno = EINTR; + } + } + return Res; + } + virtual bool InternalWriteError() APT_OVERRIDE + { + return filefd->FileFdError("lzma_write: %s (%d)", _("Write error"), lzma->err); + } + virtual bool InternalStream() const APT_OVERRIDE { return true; } + virtual bool InternalClose(std::string const &) APT_OVERRIDE + { + delete lzma; + lzma = nullptr; + return true; + } + + explicit LzmaFileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd), lzma(nullptr) {} + virtual ~LzmaFileFdPrivate() { InternalClose(""); } +#endif +}; + /*}}}*/ +class APT_HIDDEN PipedFileFdPrivate: public FileFdPrivate /*{{{*/ +/* if we don't have a specific class dealing with library calls, we (un)compress + by executing a specified binary and pipe in/out what we need */ +{ +public: + virtual bool InternalOpen(int const, unsigned int const Mode) APT_OVERRIDE + { + // collect zombies here in case we reopen + if (compressor_pid > 0) + ExecWait(compressor_pid, "FileFdCompressor", true); + + if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite) + return filefd->FileFdError("ReadWrite mode is not supported for file %s", filefd->FileName.c_str()); + if (compressor.Binary == "false") + return filefd->FileFdError("libapt has inbuilt support for the %s compression," + " but was forced to ignore it in favor of an external binary – which isn't installed.", compressor.Name.c_str()); + + bool const Comp = (Mode & FileFd::WriteOnly) == FileFd::WriteOnly; + if (Comp == false && filefd->iFd != -1) + { + // Handle 'decompression' of empty files + struct stat Buf; + if (fstat(filefd->iFd, &Buf) != 0) + return filefd->FileFdErrno("fstat", "Could not stat fd %d for file %s", filefd->iFd, filefd->FileName.c_str()); + if (Buf.st_size == 0 && S_ISFIFO(Buf.st_mode) == false) + return true; + + // We don't need the file open - instead let the compressor open it + // as he properly knows better how to efficiently read from 'his' file + if (filefd->FileName.empty() == false) + { + close(filefd->iFd); + filefd->iFd = -1; + } + } + + // Create a data pipe + int Pipe[2] = {-1,-1}; + if (pipe(Pipe) != 0) + return filefd->FileFdErrno("pipe",_("Failed to create subprocess IPC")); + for (int J = 0; J != 2; J++) + SetCloseExec(Pipe[J],true); + + compressed_fd = filefd->iFd; + set_is_pipe(true); + + if (Comp == true) + filefd->iFd = Pipe[1]; + else + filefd->iFd = Pipe[0]; + + // The child.. + compressor_pid = ExecFork(); + if (compressor_pid == 0) + { + if (Comp == true) + { + dup2(compressed_fd,STDOUT_FILENO); + dup2(Pipe[0],STDIN_FILENO); + } + else + { + if (compressed_fd != -1) + dup2(compressed_fd,STDIN_FILENO); + dup2(Pipe[1],STDOUT_FILENO); + } + int const nullfd = open("/dev/null", O_WRONLY); + if (nullfd != -1) + { + dup2(nullfd,STDERR_FILENO); + close(nullfd); + } + + SetCloseExec(STDOUT_FILENO,false); + SetCloseExec(STDIN_FILENO,false); + + std::vector<char const*> Args; + Args.push_back(compressor.Binary.c_str()); + std::vector<std::string> const * const addArgs = + (Comp == true) ? &(compressor.CompressArgs) : &(compressor.UncompressArgs); + for (std::vector<std::string>::const_iterator a = addArgs->begin(); + a != addArgs->end(); ++a) + Args.push_back(a->c_str()); + if (Comp == false && filefd->FileName.empty() == false) + { + // commands not needing arguments, do not need to be told about using standard output + // in reality, only testcases with tools like cat, rev, rot13, … are able to trigger this + if (compressor.CompressArgs.empty() == false && compressor.UncompressArgs.empty() == false) + Args.push_back("--stdout"); + if (filefd->TemporaryFileName.empty() == false) + Args.push_back(filefd->TemporaryFileName.c_str()); + else + Args.push_back(filefd->FileName.c_str()); + } + Args.push_back(NULL); + + execvp(Args[0],(char **)&Args[0]); + cerr << _("Failed to exec compressor ") << Args[0] << endl; + _exit(100); + } + if (Comp == true) + close(Pipe[0]); + else + close(Pipe[1]); + + return true; + } + virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE + { + return read(filefd->iFd, To, Size); + } + virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE + { + return write(filefd->iFd, From, Size); + } + virtual bool InternalClose(std::string const &) APT_OVERRIDE + { + bool Ret = true; + if (filefd->iFd != -1) + { + close(filefd->iFd); + filefd->iFd = -1; + } + if (compressor_pid > 0) + Ret &= ExecWait(compressor_pid, "FileFdCompressor", true); + compressor_pid = -1; + return Ret; + } + explicit PipedFileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd) {} + virtual ~PipedFileFdPrivate() { InternalClose(""); } +}; + /*}}}*/ +class APT_HIDDEN DirectFileFdPrivate: public FileFdPrivate /*{{{*/ +{ +public: + virtual bool InternalOpen(int const, unsigned int const) APT_OVERRIDE { return true; } + virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE + { + return read(filefd->iFd, To, Size); + } + virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE + { + // files opened read+write are strange and only really "supported" for direct files + if (buffer.size() != 0) + { + lseek(filefd->iFd, -buffer.size(), SEEK_CUR); + buffer.reset(); + } + return write(filefd->iFd, From, Size); + } + virtual bool InternalSeek(unsigned long long const To) APT_OVERRIDE + { + off_t const res = lseek(filefd->iFd, To, SEEK_SET); + if (res != (off_t)To) + return filefd->FileFdError("Unable to seek to %llu", To); + seekpos = To; + buffer.reset(); + return true; + } + virtual bool InternalSkip(unsigned long long Over) APT_OVERRIDE + { + if (Over >= buffer.size()) + { + Over -= buffer.size(); + buffer.reset(); + } + else + { + buffer.bufferstart += Over; + return true; + } + if (Over == 0) + return true; + off_t const res = lseek(filefd->iFd, Over, SEEK_CUR); + if (res < 0) + return filefd->FileFdError("Unable to seek ahead %llu",Over); + seekpos = res; + return true; + } + virtual bool InternalTruncate(unsigned long long const To) APT_OVERRIDE + { + if (buffer.size() != 0) + { + unsigned long long const seekpos = lseek(filefd->iFd, 0, SEEK_CUR); + if ((seekpos - buffer.size()) >= To) + buffer.reset(); + else if (seekpos >= To) + buffer.bufferend = (To - seekpos) + buffer.bufferstart; + else + buffer.reset(); + } + if (ftruncate(filefd->iFd, To) != 0) + return filefd->FileFdError("Unable to truncate to %llu",To); + return true; + } + virtual unsigned long long InternalTell() APT_OVERRIDE + { + return lseek(filefd->iFd,0,SEEK_CUR) - buffer.size(); + } + virtual unsigned long long InternalSize() APT_OVERRIDE + { + return filefd->FileSize(); + } + virtual bool InternalClose(std::string const &) APT_OVERRIDE { return true; } + virtual bool InternalAlwaysAutoClose() const APT_OVERRIDE { return false; } + + explicit DirectFileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd) {} + virtual ~DirectFileFdPrivate() { InternalClose(""); } +}; + /*}}}*/ +// FileFd Constructors /*{{{*/ +FileFd::FileFd(std::string FileName,unsigned int const Mode,unsigned long AccessMode) : iFd(-1), Flags(0), d(NULL) +{ + Open(FileName,Mode, None, AccessMode); +} +FileFd::FileFd(std::string FileName,unsigned int const Mode, CompressMode Compress, unsigned long AccessMode) : iFd(-1), Flags(0), d(NULL) +{ + Open(FileName,Mode, Compress, AccessMode); +} +FileFd::FileFd() : iFd(-1), Flags(AutoClose), d(NULL) {} +FileFd::FileFd(int const Fd, unsigned int const Mode, CompressMode Compress) : iFd(-1), Flags(0), d(NULL) +{ + OpenDescriptor(Fd, Mode, Compress); +} +FileFd::FileFd(int const Fd, bool const AutoClose) : iFd(-1), Flags(0), d(NULL) +{ + OpenDescriptor(Fd, ReadWrite, None, AutoClose); +} + /*}}}*/ +// FileFd::Open - Open a file /*{{{*/ +// --------------------------------------------------------------------- +/* The most commonly used open mode combinations are given with Mode */ +bool FileFd::Open(string FileName,unsigned int const Mode,CompressMode Compress, unsigned long const AccessMode) +{ + if (Mode == ReadOnlyGzip) + return Open(FileName, ReadOnly, Gzip, AccessMode); + + if (Compress == Auto && (Mode & WriteOnly) == WriteOnly) + return FileFdError("Autodetection on %s only works in ReadOnly openmode!", FileName.c_str()); + + std::vector<APT::Configuration::Compressor> const compressors = APT::Configuration::getCompressors(); + std::vector<APT::Configuration::Compressor>::const_iterator compressor = compressors.begin(); + if (Compress == Auto) + { + for (; compressor != compressors.end(); ++compressor) + { + std::string file = FileName + compressor->Extension; + if (FileExists(file) == false) + continue; + FileName = file; + break; + } + } + else if (Compress == Extension) + { + std::string::size_type const found = FileName.find_last_of('.'); + std::string ext; + if (found != std::string::npos) + { + ext = FileName.substr(found); + if (ext == ".new" || ext == ".bak") + { + std::string::size_type const found2 = FileName.find_last_of('.', found - 1); + if (found2 != std::string::npos) + ext = FileName.substr(found2, found - found2); + else + ext.clear(); + } + } + for (; compressor != compressors.end(); ++compressor) + if (ext == compressor->Extension) + break; + // no matching extension - assume uncompressed (imagine files like 'example.org_Packages') + if (compressor == compressors.end()) + for (compressor = compressors.begin(); compressor != compressors.end(); ++compressor) + if (compressor->Name == ".") + break; + } + else + { + std::string name; + switch (Compress) + { + case None: name = "."; break; + case Gzip: name = "gzip"; break; + case Bzip2: name = "bzip2"; break; + case Lzma: name = "lzma"; break; + case Xz: name = "xz"; break; + case Lz4: name = "lz4"; break; + case Zstd: name = "zstd"; break; + case Auto: + case Extension: + // Unreachable + return FileFdError("Opening File %s in None, Auto or Extension should be already handled?!?", FileName.c_str()); + } + for (; compressor != compressors.end(); ++compressor) + if (compressor->Name == name) + break; + if (compressor == compressors.end()) + return FileFdError("Can't find a configured compressor %s for file %s", name.c_str(), FileName.c_str()); + } + + if (compressor == compressors.end()) + return FileFdError("Can't find a match for specified compressor mode for file %s", FileName.c_str()); + return Open(FileName, Mode, *compressor, AccessMode); +} +bool FileFd::Open(string FileName,unsigned int const Mode,APT::Configuration::Compressor const &compressor, unsigned long const AccessMode) +{ + Close(); + Flags = AutoClose; + + if ((Mode & WriteOnly) != WriteOnly && (Mode & (Atomic | Create | Empty | Exclusive)) != 0) + return FileFdError("ReadOnly mode for %s doesn't accept additional flags!", FileName.c_str()); + if ((Mode & ReadWrite) == 0) + return FileFdError("No openmode provided in FileFd::Open for %s", FileName.c_str()); + + unsigned int OpenMode = Mode; + if (FileName == "/dev/null") + OpenMode = OpenMode & ~(Atomic | Exclusive | Create | Empty); + + if ((OpenMode & Atomic) == Atomic) + { + Flags |= Replace; + } + else if ((OpenMode & (Exclusive | Create)) == (Exclusive | Create)) + { + // for atomic, this will be done by rename in Close() + RemoveFile("FileFd::Open", FileName); + } + if ((OpenMode & Empty) == Empty) + { + struct stat Buf; + if (lstat(FileName.c_str(),&Buf) == 0 && S_ISLNK(Buf.st_mode)) + RemoveFile("FileFd::Open", FileName); + } + + int fileflags = 0; + #define if_FLAGGED_SET(FLAG, MODE) if ((OpenMode & FLAG) == FLAG) fileflags |= MODE + if_FLAGGED_SET(ReadWrite, O_RDWR); + else if_FLAGGED_SET(ReadOnly, O_RDONLY); + else if_FLAGGED_SET(WriteOnly, O_WRONLY); + + if_FLAGGED_SET(Create, O_CREAT); + if_FLAGGED_SET(Empty, O_TRUNC); + if_FLAGGED_SET(Exclusive, O_EXCL); + #undef if_FLAGGED_SET + + if ((OpenMode & Atomic) == Atomic) + { + char *name = strdup((FileName + ".XXXXXX").c_str()); + + if((iFd = mkstemp(name)) == -1) + { + free(name); + return FileFdErrno("mkstemp", "Could not create temporary file for %s", FileName.c_str()); + } + + TemporaryFileName = string(name); + free(name); + + // umask() will always set the umask and return the previous value, so + // we first set the umask and then reset it to the old value + mode_t const CurrentUmask = umask(0); + umask(CurrentUmask); + // calculate the actual file permissions (just like open/creat) + mode_t const FilePermissions = (AccessMode & ~CurrentUmask); + + if(fchmod(iFd, FilePermissions) == -1) + return FileFdErrno("fchmod", "Could not change permissions for temporary file %s", TemporaryFileName.c_str()); + } + else + iFd = open(FileName.c_str(), fileflags, AccessMode); + + this->FileName = FileName; + if (iFd == -1 || OpenInternDescriptor(OpenMode, compressor) == false) + { + if (iFd != -1) + { + close (iFd); + iFd = -1; + } + return FileFdErrno("open",_("Could not open file %s"), FileName.c_str()); + } + + SetCloseExec(iFd,true); + return true; +} + /*}}}*/ +// FileFd::OpenDescriptor - Open a filedescriptor /*{{{*/ +bool FileFd::OpenDescriptor(int Fd, unsigned int const Mode, CompressMode Compress, bool AutoClose) +{ + std::vector<APT::Configuration::Compressor> const compressors = APT::Configuration::getCompressors(); + std::vector<APT::Configuration::Compressor>::const_iterator compressor = compressors.begin(); + std::string name; + + // compat with the old API + if (Mode == ReadOnlyGzip && Compress == None) + Compress = Gzip; + + switch (Compress) + { + case None: name = "."; break; + case Gzip: name = "gzip"; break; + case Bzip2: name = "bzip2"; break; + case Lzma: name = "lzma"; break; + case Xz: name = "xz"; break; + case Lz4: name = "lz4"; break; + case Zstd: name = "zstd"; break; + case Auto: + case Extension: + if (AutoClose == true && Fd != -1) + close(Fd); + return FileFdError("Opening Fd %d in Auto or Extension compression mode is not supported", Fd); + } + for (; compressor != compressors.end(); ++compressor) + if (compressor->Name == name) + break; + if (compressor == compressors.end()) + { + if (AutoClose == true && Fd != -1) + close(Fd); + return FileFdError("Can't find a configured compressor %s for file %s", name.c_str(), FileName.c_str()); + } + return OpenDescriptor(Fd, Mode, *compressor, AutoClose); +} +bool FileFd::OpenDescriptor(int Fd, unsigned int const Mode, APT::Configuration::Compressor const &compressor, bool AutoClose) +{ + Close(); + Flags = (AutoClose) ? FileFd::AutoClose : 0; + iFd = Fd; + this->FileName = ""; + if (OpenInternDescriptor(Mode, compressor) == false) + { + if (iFd != -1 && ( + (Flags & Compressed) == Compressed || + AutoClose == true)) + { + close (iFd); + iFd = -1; + } + return FileFdError(_("Could not open file descriptor %d"), Fd); + } + return true; +} +bool FileFd::OpenInternDescriptor(unsigned int const Mode, APT::Configuration::Compressor const &compressor) +{ + if (iFd == -1) + return false; + + if (d != nullptr) + d->InternalClose(FileName); + + if (d == nullptr) + { + if (false) + /* dummy so that the rest can be 'else if's */; +#define APT_COMPRESS_INIT(NAME, CONSTRUCTOR) \ + else if (compressor.Name == NAME) \ + d = new CONSTRUCTOR(this) +#ifdef HAVE_ZLIB + APT_COMPRESS_INIT("gzip", GzipFileFdPrivate); +#endif +#ifdef HAVE_BZ2 + APT_COMPRESS_INIT("bzip2", Bz2FileFdPrivate); +#endif +#ifdef HAVE_LZMA + APT_COMPRESS_INIT("xz", LzmaFileFdPrivate); + APT_COMPRESS_INIT("lzma", LzmaFileFdPrivate); +#endif +#ifdef HAVE_LZ4 + APT_COMPRESS_INIT("lz4", Lz4FileFdPrivate); +#endif +#ifdef HAVE_ZSTD + APT_COMPRESS_INIT("zstd", ZstdFileFdPrivate); +#endif +#undef APT_COMPRESS_INIT + else if (compressor.Name == "." || compressor.Binary.empty() == true) + d = new DirectFileFdPrivate(this); + else + d = new PipedFileFdPrivate(this); + + if (Mode & BufferedWrite) + d = new BufferedWriteFileFdPrivate(d); + + d->set_openmode(Mode); + d->set_compressor(compressor); + if ((Flags & AutoClose) != AutoClose && d->InternalAlwaysAutoClose()) + { + // Need to duplicate fd here or gz/bz2 close for cleanup will close the fd as well + int const internFd = dup(iFd); + if (internFd == -1) + return FileFdErrno("OpenInternDescriptor", _("Could not open file descriptor %d"), iFd); + iFd = internFd; + } + } + return d->InternalOpen(iFd, Mode); +} + /*}}}*/ +// FileFd::~File - Closes the file /*{{{*/ +// --------------------------------------------------------------------- +/* If the proper modes are selected then we close the Fd and possibly + unlink the file on error. */ +FileFd::~FileFd() +{ + Close(); + if (d != NULL) + d->InternalClose(FileName); + delete d; + d = NULL; +} + /*}}}*/ +// FileFd::Read - Read a bit of the file /*{{{*/ +// --------------------------------------------------------------------- +/* We are careful to handle interruption by a signal while reading + gracefully. */ +bool FileFd::Read(void *To,unsigned long long Size,unsigned long long *Actual) +{ + if (d == nullptr || Failed()) + return false; + ssize_t Res = 1; + errno = 0; + if (Actual != 0) + *Actual = 0; + *((char *)To) = '\0'; + while (Res > 0 && Size > 0) + { + Res = d->InternalRead(To, Size); + + if (Res < 0) + { + if (errno == EINTR) + { + // trick the while-loop into running again + Res = 1; + errno = 0; + continue; + } + return d->InternalReadError(); + } + + To = (char *)To + Res; + Size -= Res; + if (d != NULL) + d->set_seekpos(d->get_seekpos() + Res); + if (Actual != 0) + *Actual += Res; + } + + if (Size == 0) + return true; + + // Eof handling + if (Actual != 0) + { + Flags |= HitEof; + return true; + } + + return FileFdError(_("read, still have %llu to read but none left"), Size); +} +bool FileFd::Read(int const Fd, void *To, unsigned long long Size, unsigned long long * const Actual) +{ + ssize_t Res = 1; + errno = 0; + if (Actual != nullptr) + *Actual = 0; + *static_cast<char *>(To) = '\0'; + while (Res > 0 && Size > 0) + { + Res = read(Fd, To, Size); + if (Res < 0) + { + if (errno == EINTR) + { + Res = 1; + errno = 0; + continue; + } + return _error->Errno("read", _("Read error")); + } + To = static_cast<char *>(To) + Res; + Size -= Res; + if (Actual != 0) + *Actual += Res; + } + if (Size == 0) + return true; + if (Actual != nullptr) + return true; + return _error->Error(_("read, still have %llu to read but none left"), Size); +} + /*}}}*/ +// FileFd::ReadLine - Read a complete line from the file /*{{{*/ +char* FileFd::ReadLine(char *To, unsigned long long const Size) +{ + *To = '\0'; + if (d == nullptr || Failed()) + return nullptr; + return d->InternalReadLine(To, Size); +} +bool FileFd::ReadLine(std::string &To) +{ + To.clear(); + if (d == nullptr || Failed()) + return false; + constexpr size_t buflen = 4096; + char buffer[buflen]; + size_t len; + do + { + if (d->InternalReadLine(buffer, buflen) == nullptr) + return false; + len = strlen(buffer); + To.append(buffer, len); + } while (len == buflen - 1 && buffer[len - 2] != '\n'); + // remove the newline at the end + auto const i = To.find_last_not_of("\r\n"); + if (i == std::string::npos) + To.clear(); + else + To.erase(i + 1); + return true; +} + /*}}}*/ +// FileFd::Flush - Flush the file /*{{{*/ +bool FileFd::Flush() +{ + if (Failed()) + return false; + if (d == nullptr) + return true; + + return d->InternalFlush(); +} + /*}}}*/ +// FileFd::Write - Write to the file /*{{{*/ +bool FileFd::Write(const void *From,unsigned long long Size) +{ + if (d == nullptr || Failed()) + return false; + ssize_t Res = 1; + errno = 0; + while (Res > 0 && Size > 0) + { + Res = d->InternalWrite(From, Size); + + if (Res < 0) + { + if (errno == EINTR) + { + // trick the while-loop into running again + Res = 1; + errno = 0; + continue; + } + return d->InternalWriteError(); + } + + From = (char const *)From + Res; + Size -= Res; + if (d != NULL) + d->set_seekpos(d->get_seekpos() + Res); + } + + if (Size == 0) + return true; + + return FileFdError(_("write, still have %llu to write but couldn't"), Size); +} +bool FileFd::Write(int Fd, const void *From, unsigned long long Size) +{ + ssize_t Res = 1; + errno = 0; + while (Res > 0 && Size > 0) + { + Res = write(Fd,From,Size); + if (Res < 0 && errno == EINTR) + continue; + if (Res < 0) + return _error->Errno("write",_("Write error")); + + From = (char const *)From + Res; + Size -= Res; + } + + if (Size == 0) + return true; + + return _error->Error(_("write, still have %llu to write but couldn't"), Size); +} + /*}}}*/ +// FileFd::Seek - Seek in the file /*{{{*/ +bool FileFd::Seek(unsigned long long To) +{ + if (d == nullptr || Failed()) + return false; + Flags &= ~HitEof; + return d->InternalSeek(To); +} + /*}}}*/ +// FileFd::Skip - Skip over data in the file /*{{{*/ +bool FileFd::Skip(unsigned long long Over) +{ + if (d == nullptr || Failed()) + return false; + return d->InternalSkip(Over); +} + /*}}}*/ +// FileFd::Truncate - Truncate the file /*{{{*/ +bool FileFd::Truncate(unsigned long long To) +{ + if (d == nullptr || Failed()) + return false; + // truncating /dev/null is always successful - as we get an error otherwise + if (To == 0 && FileName == "/dev/null") + return true; + return d->InternalTruncate(To); +} + /*}}}*/ +// FileFd::Tell - Current seek position /*{{{*/ +// --------------------------------------------------------------------- +/* */ +unsigned long long FileFd::Tell() +{ + if (d == nullptr || Failed()) + return false; + off_t const Res = d->InternalTell(); + if (Res == (off_t)-1) + FileFdErrno("lseek","Failed to determine the current file position"); + d->set_seekpos(Res); + return Res; +} + /*}}}*/ +static bool StatFileFd(char const * const msg, int const iFd, std::string const &FileName, struct stat &Buf, FileFdPrivate * const d) /*{{{*/ +{ + bool ispipe = (d != NULL && d->get_is_pipe() == true); + if (ispipe == false) + { + if (fstat(iFd,&Buf) != 0) + // higher-level code will generate more meaningful messages, + // even translated this would be meaningless for users + return _error->Errno("fstat", "Unable to determine %s for fd %i", msg, iFd); + if (FileName.empty() == false) + ispipe = S_ISFIFO(Buf.st_mode); + } + + // for compressor pipes st_size is undefined and at 'best' zero + if (ispipe == true) + { + // we set it here, too, as we get the info here for free + // in theory the Open-methods should take care of it already + if (d != NULL) + d->set_is_pipe(true); + if (stat(FileName.c_str(), &Buf) != 0) + return _error->Errno("fstat", "Unable to determine %s for file %s", msg, FileName.c_str()); + } + return true; +} + /*}}}*/ +// FileFd::FileSize - Return the size of the file /*{{{*/ +unsigned long long FileFd::FileSize() +{ + struct stat Buf; + if (StatFileFd("file size", iFd, FileName, Buf, d) == false) + { + Flags |= Fail; + return 0; + } + return Buf.st_size; +} + /*}}}*/ +// FileFd::ModificationTime - Return the time of last touch /*{{{*/ +time_t FileFd::ModificationTime() +{ + struct stat Buf; + if (StatFileFd("modification time", iFd, FileName, Buf, d) == false) + { + Flags |= Fail; + return 0; + } + return Buf.st_mtime; +} + /*}}}*/ +// FileFd::Size - Return the size of the content in the file /*{{{*/ +unsigned long long FileFd::Size() +{ + if (d == nullptr) + return 0; + return d->InternalSize(); +} + /*}}}*/ +// FileFd::Close - Close the file if the close flag is set /*{{{*/ +// --------------------------------------------------------------------- +/* */ +bool FileFd::Close() +{ + if (Failed() == false && Flush() == false) + return false; + if (iFd == -1) + return true; + + bool Res = true; + if ((Flags & AutoClose) == AutoClose) + { + if ((Flags & Compressed) != Compressed && iFd > 0 && close(iFd) != 0) + Res &= _error->Errno("close",_("Problem closing the file %s"), FileName.c_str()); + } + + if (d != NULL) + { + Res &= d->InternalClose(FileName); + delete d; + d = NULL; + } + + if ((Flags & Replace) == Replace) { + if (Failed() == false && rename(TemporaryFileName.c_str(), FileName.c_str()) != 0) + Res &= _error->Errno("rename",_("Problem renaming the file %s to %s"), TemporaryFileName.c_str(), FileName.c_str()); + + FileName = TemporaryFileName; // for the unlink() below. + TemporaryFileName.clear(); + } + + iFd = -1; + + if ((Flags & Fail) == Fail && (Flags & DelOnFail) == DelOnFail && + FileName.empty() == false) + Res &= RemoveFile("FileFd::Close", FileName); + + if (Res == false) + Flags |= Fail; + return Res; +} + /*}}}*/ +// FileFd::Sync - Sync the file /*{{{*/ +// --------------------------------------------------------------------- +/* */ +bool FileFd::Sync() +{ + if (fsync(iFd) != 0) + return FileFdErrno("sync",_("Problem syncing the file")); + return true; +} + /*}}}*/ +// FileFd::FileFdErrno - set Fail and call _error->Errno *{{{*/ +bool FileFd::FileFdErrno(const char *Function, const char *Description,...) +{ + Flags |= Fail; + va_list args; + size_t msgSize = 400; + int const errsv = errno; + bool retry; + do { + va_start(args,Description); + retry = _error->InsertErrno(GlobalError::ERROR, Function, Description, args, errsv, msgSize); + va_end(args); + } while (retry); + return false; +} + /*}}}*/ +// FileFd::FileFdError - set Fail and call _error->Error *{{{*/ +bool FileFd::FileFdError(const char *Description,...) { + Flags |= Fail; + va_list args; + size_t msgSize = 400; + bool retry; + do { + va_start(args,Description); + retry = _error->Insert(GlobalError::ERROR, Description, args, msgSize); + va_end(args); + } while (retry); + return false; +} + /*}}}*/ +gzFile FileFd::gzFd() { /*{{{*/ +#ifdef HAVE_ZLIB + GzipFileFdPrivate * const gzipd = dynamic_cast<GzipFileFdPrivate*>(d); + if (gzipd == nullptr) + return nullptr; + else + return gzipd->gz; +#else + return nullptr; +#endif +} + /*}}}*/ + +// Glob - wrapper around "glob()" /*{{{*/ +std::vector<std::string> Glob(std::string const &pattern, int flags) +{ + std::vector<std::string> result; + glob_t globbuf; + int glob_res; + unsigned int i; + + glob_res = glob(pattern.c_str(), flags, NULL, &globbuf); + + if (glob_res != 0) + { + if(glob_res != GLOB_NOMATCH) { + _error->Errno("glob", "Problem with glob"); + return result; + } + } + + // append results + for(i=0;i<globbuf.gl_pathc;i++) + result.push_back(string(globbuf.gl_pathv[i])); + + globfree(&globbuf); + return result; +} + /*}}}*/ +static std::string APT_NONNULL(1) GetTempDirEnv(char const * const env) /*{{{*/ +{ + const char *tmpdir = getenv(env); + +#ifdef P_tmpdir + if (!tmpdir) + tmpdir = P_tmpdir; +#endif + + struct stat st; + if (!tmpdir || strlen(tmpdir) == 0 || // tmpdir is set + stat(tmpdir, &st) != 0 || (st.st_mode & S_IFDIR) == 0) // exists and is directory + tmpdir = "/tmp"; + else if (geteuid() != 0 && // root can do everything anyway + faccessat(AT_FDCWD, tmpdir, R_OK | W_OK | X_OK, AT_EACCESS) != 0) // current user has rwx access to directory + tmpdir = "/tmp"; + + return string(tmpdir); +} + /*}}}*/ +std::string GetTempDir() /*{{{*/ +{ + return GetTempDirEnv("TMPDIR"); +} +std::string GetTempDir(std::string const &User) +{ + // no need/possibility to drop privs + if(getuid() != 0 || User.empty() || User == "root") + return GetTempDir(); + + struct passwd const * const pw = getpwnam(User.c_str()); + if (pw == NULL) + return GetTempDir(); + + gid_t const old_euid = geteuid(); + gid_t const old_egid = getegid(); + if (setegid(pw->pw_gid) != 0) + _error->Errno("setegid", "setegid %u failed", pw->pw_gid); + if (seteuid(pw->pw_uid) != 0) + _error->Errno("seteuid", "seteuid %u failed", pw->pw_uid); + + std::string const tmp = GetTempDir(); + + if (seteuid(old_euid) != 0) + _error->Errno("seteuid", "seteuid %u failed", old_euid); + if (setegid(old_egid) != 0) + _error->Errno("setegid", "setegid %u failed", old_egid); + + return tmp; +} + /*}}}*/ +FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink, FileFd * const TmpFd) /*{{{*/ +{ + return GetTempFile(Prefix, ImmediateUnlink, TmpFd, false); +} +FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink, FileFd * const TmpFd, bool Buffered) +{ + char fn[512]; + FileFd * const Fd = TmpFd == nullptr ? new FileFd() : TmpFd; + + std::string const tempdir = GetTempDir(); + snprintf(fn, sizeof(fn), "%s/%s.XXXXXX", + tempdir.c_str(), Prefix.c_str()); + int const fd = mkstemp(fn); + if (ImmediateUnlink) + unlink(fn); + if (fd < 0) + { + _error->Errno("GetTempFile",_("Unable to mkstemp %s"), fn); + if (TmpFd == nullptr) + delete Fd; + return nullptr; + } + if (!Fd->OpenDescriptor(fd, FileFd::ReadWrite | (Buffered ? FileFd::BufferedWrite : 0), FileFd::None, true)) + { + _error->Errno("GetTempFile",_("Unable to write to %s"),fn); + if (TmpFd == nullptr) + delete Fd; + return nullptr; + } + if (ImmediateUnlink == false) + Fd->SetFileName(fn); + return Fd; +} + /*}}}*/ +bool Rename(std::string From, std::string To) /*{{{*/ +{ + if (rename(From.c_str(),To.c_str()) != 0) + { + _error->Error(_("rename failed, %s (%s -> %s)."),strerror(errno), + From.c_str(),To.c_str()); + return false; + } + return true; +} + /*}}}*/ +bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)/*{{{*/ +{ + return Popen(Args, Fd, Child, Mode, true); +} + /*}}}*/ +bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode, bool CaptureStderr)/*{{{*/ +{ + return Popen(Args, Fd, Child, Mode, CaptureStderr, false); +} + /*}}}*/ +bool Popen(const char *Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode, bool CaptureStderr, bool Sandbox) /*{{{*/ +{ + int fd; + if (Mode != FileFd::ReadOnly && Mode != FileFd::WriteOnly) + return _error->Error("Popen supports ReadOnly (x)or WriteOnly mode only"); + + int Pipe[2] = {-1, -1}; + if(pipe(Pipe) != 0) + return _error->Errno("pipe", _("Failed to create subprocess IPC")); + + std::set<int> keep_fds; + keep_fds.insert(Pipe[0]); + keep_fds.insert(Pipe[1]); + Child = ExecFork(keep_fds); + if(Child < 0) + return _error->Errno("fork", "Failed to fork"); + if(Child == 0) + { + if (Sandbox && (getuid() == 0 || geteuid() == 0) && !DropPrivileges()) + { + _error->DumpErrors(); + _exit(1); + } + if(Mode == FileFd::ReadOnly) + { + close(Pipe[0]); + fd = Pipe[1]; + } + else if(Mode == FileFd::WriteOnly) + { + close(Pipe[1]); + fd = Pipe[0]; + } + + if(Mode == FileFd::ReadOnly) + { + dup2(fd, 1); + if (CaptureStderr == true) + dup2(fd, 2); + } else if(Mode == FileFd::WriteOnly) + dup2(fd, 0); + + execv(Args[0], (char**)Args); + _exit(100); + } + if(Mode == FileFd::ReadOnly) + { + close(Pipe[1]); + fd = Pipe[0]; + } + else if(Mode == FileFd::WriteOnly) + { + close(Pipe[0]); + fd = Pipe[1]; + } + else + return _error->Error("Popen supports ReadOnly (x)or WriteOnly mode only"); + Fd.OpenDescriptor(fd, Mode, FileFd::None, true); + + return true; +} + /*}}}*/ +bool DropPrivileges() /*{{{*/ +{ + if(_config->FindB("Debug::NoDropPrivs", false) == true) + return true; + +#if __gnu_linux__ +#if defined(PR_SET_NO_NEW_PRIVS) && ( PR_SET_NO_NEW_PRIVS != 38 ) +#error "PR_SET_NO_NEW_PRIVS is defined, but with a different value than expected!" +#endif + // see prctl(2), needs linux3.5 at runtime - magic constant to avoid it at buildtime + int ret = prctl(38, 1, 0, 0, 0); + // ignore EINVAL - kernel is too old to understand the option + if(ret < 0 && errno != EINVAL) + _error->Warning("PR_SET_NO_NEW_PRIVS failed with %i", ret); +#endif + + // empty setting disables privilege dropping - this also ensures + // backward compatibility, see bug #764506 + const std::string toUser = _config->Find("APT::Sandbox::User"); + if (toUser.empty() || toUser == "root") + return true; + + // a lot can go wrong trying to drop privileges completely, + // so ideally we would like to verify that we have done it – + // but the verify asks for too much in case of fakeroot (and alike) + // [Specific checks can be overridden with dedicated options] + bool const VerifySandboxing = _config->FindB("APT::Sandbox::Verify", false); + + // uid will be 0 in the end, but gid might be different anyway + uid_t const old_uid = getuid(); + gid_t const old_gid = getgid(); + + if (old_uid != 0) + return true; + + struct passwd *pw = getpwnam(toUser.c_str()); + if (pw == NULL) + return _error->Error("No user %s, can not drop rights", toUser.c_str()); + + // Do not change the order here, it might break things + // Get rid of all our supplementary groups first + if (setgroups(1, &pw->pw_gid)) + return _error->Errno("setgroups", "Failed to setgroups"); + + // Now change the group ids to the new user +#ifdef HAVE_SETRESGID + if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) + return _error->Errno("setresgid", "Failed to set new group ids"); +#else + if (setegid(pw->pw_gid) != 0) + return _error->Errno("setegid", "Failed to setegid"); + + if (setgid(pw->pw_gid) != 0) + return _error->Errno("setgid", "Failed to setgid"); +#endif + + // Change the user ids to the new user +#ifdef HAVE_SETRESUID + if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0) + return _error->Errno("setresuid", "Failed to set new user ids"); +#else + if (setuid(pw->pw_uid) != 0) + return _error->Errno("setuid", "Failed to setuid"); + if (seteuid(pw->pw_uid) != 0) + return _error->Errno("seteuid", "Failed to seteuid"); +#endif + + // disabled by default as fakeroot doesn't implement getgroups currently (#806521) + if (VerifySandboxing == true || _config->FindB("APT::Sandbox::Verify::Groups", false) == true) + { + // Verify that the user isn't still in any supplementary groups + long const ngroups_max = sysconf(_SC_NGROUPS_MAX); + std::unique_ptr<gid_t[]> gidlist(new gid_t[ngroups_max]); + if (unlikely(gidlist == NULL)) + return _error->Error("Allocation of a list of size %lu for getgroups failed", ngroups_max); + ssize_t gidlist_nr; + if ((gidlist_nr = getgroups(ngroups_max, gidlist.get())) < 0) + return _error->Errno("getgroups", "Could not get new groups (%lu)", ngroups_max); + for (ssize_t i = 0; i < gidlist_nr; ++i) + if (gidlist[i] != pw->pw_gid) + return _error->Error("Could not switch group, user %s is still in group %d", toUser.c_str(), gidlist[i]); + } + + // enabled by default as all fakeroot-lookalikes should fake that accordingly + if (VerifySandboxing == true || _config->FindB("APT::Sandbox::Verify::IDs", true) == true) + { + // Verify that gid, egid, uid, and euid changed + if (getgid() != pw->pw_gid) + return _error->Error("Could not switch group"); + if (getegid() != pw->pw_gid) + return _error->Error("Could not switch effective group"); + if (getuid() != pw->pw_uid) + return _error->Error("Could not switch user"); + if (geteuid() != pw->pw_uid) + return _error->Error("Could not switch effective user"); + +#ifdef HAVE_GETRESUID + // verify that the saved set-user-id was changed as well + uid_t ruid = 0; + uid_t euid = 0; + uid_t suid = 0; + if (getresuid(&ruid, &euid, &suid)) + return _error->Errno("getresuid", "Could not get saved set-user-ID"); + if (suid != pw->pw_uid) + return _error->Error("Could not switch saved set-user-ID"); +#endif + +#ifdef HAVE_GETRESGID + // verify that the saved set-group-id was changed as well + gid_t rgid = 0; + gid_t egid = 0; + gid_t sgid = 0; + if (getresgid(&rgid, &egid, &sgid)) + return _error->Errno("getresuid", "Could not get saved set-group-ID"); + if (sgid != pw->pw_gid) + return _error->Error("Could not switch saved set-group-ID"); +#endif + } + + // disabled as fakeroot doesn't forbid (by design) (re)gaining root from unprivileged + if (VerifySandboxing == true || _config->FindB("APT::Sandbox::Verify::Regain", false) == true) + { + // Check that uid and gid changes do not work anymore + if (pw->pw_gid != old_gid && (setgid(old_gid) != -1 || setegid(old_gid) != -1)) + return _error->Error("Could restore a gid to root, privilege dropping did not work"); + + if (pw->pw_uid != old_uid && (setuid(old_uid) != -1 || seteuid(old_uid) != -1)) + return _error->Error("Could restore a uid to root, privilege dropping did not work"); + } + + if (_config->FindB("APT::Sandbox::ResetEnvironment", true)) + { + setenv("HOME", pw->pw_dir, 1); + setenv("USER", pw->pw_name, 1); + setenv("USERNAME", pw->pw_name, 1); + setenv("LOGNAME", pw->pw_name, 1); + auto const shell = flNotDir(pw->pw_shell); + if (shell == "false" || shell == "nologin") + setenv("SHELL", "/bin/sh", 1); + else + setenv("SHELL", pw->pw_shell, 1); + auto const apt_setenv_tmp = [](char const * const env) { + auto const tmpdir = getenv(env); + if (tmpdir != nullptr) + { + auto const ourtmpdir = GetTempDirEnv(env); + if (ourtmpdir != tmpdir) + setenv(env, ourtmpdir.c_str(), 1); + } + }; + apt_setenv_tmp("TMPDIR"); + apt_setenv_tmp("TEMPDIR"); + apt_setenv_tmp("TMP"); + apt_setenv_tmp("TEMP"); + } + + return true; +} + /*}}}*/ +bool OpenConfigurationFileFd(std::string const &File, FileFd &Fd) /*{{{*/ +{ + int const fd = open(File.c_str(), O_RDONLY | O_CLOEXEC | O_NOCTTY); + if (fd == -1) + return _error->WarningE("open", _("Unable to read %s"), File.c_str()); + APT::Configuration::Compressor none(".", "", "", nullptr, nullptr, 0); + if (Fd.OpenDescriptor(fd, FileFd::ReadOnly, none, true) == false) + return false; + Fd.SetFileName(File); + return true; +} + /*}}}*/ +int Inhibit(const char *what, const char *who, const char *why, const char *mode) /*{{{*/ +{ +#ifdef HAVE_SYSTEMD + sd_bus_error error = SD_BUS_ERROR_NULL; + sd_bus_message *m = NULL; + sd_bus *bus = NULL; + int fd; + int r; + + r = sd_bus_open_system(&bus); + if (r < 0) + goto out; + + r = sd_bus_call_method(bus, + "org.freedesktop.login1", + "/org/freedesktop/login1", + "org.freedesktop.login1.Manager", + "Inhibit", + &error, + &m, + "ssss", + what, + who, + why, + mode); + if (r < 0) + goto out; + + r = sd_bus_message_read(m, "h", &fd); + if (r < 0) + goto out; + + // We received a file descriptor, return it - systemd will close the read fd + // on free, so let's duplicate it here. + r = dup(fd); +out: + sd_bus_error_free(&error); + sd_bus_message_unref(m); + sd_bus_unref(bus); + return r; +#else + return -ENOTSUP; +#endif +} + /*}}}*/ |