X-Git-Url: https://git.saurik.com/apt.git/blobdiff_plain/4fc6b7570c3e97b65c118b58cdf6729fa94c9b03..2fc9d1ebca203b4a159dba5e817081155099f6ab:/apt-pkg/contrib/fileutl.cc diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc index 8ec868ec0..02b27f5cf 100644 --- a/apt-pkg/contrib/fileutl.cc +++ b/apt-pkg/contrib/fileutl.cc @@ -52,6 +52,7 @@ #include #include +#include #ifdef HAVE_ZLIB #include @@ -157,24 +158,18 @@ 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 - SPtrArray Buf = new unsigned char[64000]; - unsigned long long Size = From.Size(); - while (Size != 0) - { - unsigned long long ToRead = Size; - if (Size > 64000) - ToRead = 64000; - - if (From.Read(Buf,ToRead) == false || - To.Write(Buf,ToRead) == false) + std::unique_ptr Buf(new unsigned char[64000]); + constexpr unsigned long long BufSize = sizeof(Buf.get())/sizeof(Buf.get()[0]); + unsigned long long ToRead = 0; + do { + if (From.Read(Buf.get(),BufSize, &ToRead) == false || + To.Write(Buf.get(),ToRead) == false) return false; - - Size -= ToRead; - } + } while (ToRead != 0); - return true; + return true; } /*}}}*/ // GetLock - Gets a lock file /*{{{*/ @@ -670,7 +665,7 @@ string flAbsPath(string File) char *p = realpath(File.c_str(), NULL); if (p == NULL) { - _error->Errno("realpath", "flAbsPath failed"); + _error->Errno("realpath", "flAbsPath on %s failed", File.c_str()); return ""; } std::string AbsPath(p); @@ -800,12 +795,26 @@ pid_t ExecFork(std::set KeepFDs) signal(SIGCONT,SIG_DFL); signal(SIGTSTP,SIG_DFL); - long ScOpenMax = sysconf(_SC_OPEN_MAX); - // Close all of our FDs - just in case - for (int K = 3; K != ScOpenMax; K++) + DIR *dir = opendir("/proc/self/fd"); + if (dir != NULL) { - if(KeepFDs.find(K) == KeepFDs.end()) - fcntl(K,F_SETFD,FD_CLOEXEC); + 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); + } } } @@ -1011,6 +1020,25 @@ class FileFdPrivate { /*{{{*/ ~FileFdPrivate() { CloseDown(""); } }; /*}}}*/ +// 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 */ @@ -1972,12 +2000,13 @@ bool FileFd::Close() { 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->CloseDown(FileName); - delete d; - d = NULL; - } + } + + if (d != NULL) + { + Res &= d->CloseDown(FileName); + delete d; + d = NULL; } if ((Flags & Replace) == Replace) { @@ -2088,36 +2117,62 @@ std::string GetTempDir() /*{{{*/ 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 - access(tmpdir, R_OK | W_OK | X_OK) != 0 // current user has rwx access to directory - ) + 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(-1, tmpdir, R_OK | W_OK | X_OK, AT_EACCESS | AT_SYMLINK_NOFOLLOW) != 0) // current user has rwx access to directory tmpdir = "/tmp"; return string(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* GetTempFile(std::string const &Prefix, bool ImmediateUnlink, FileFd * const TmpFd) /*{{{*/ { char fn[512]; - FileFd *Fd = new FileFd(); + FileFd * const Fd = TmpFd == NULL ? new FileFd() : TmpFd; - std::string tempdir = GetTempDir(); - snprintf(fn, sizeof(fn), "%s/%s.XXXXXX", + std::string const tempdir = GetTempDir(); + snprintf(fn, sizeof(fn), "%s/%s.XXXXXX", tempdir.c_str(), Prefix.c_str()); - int fd = mkstemp(fn); + int const fd = mkstemp(fn); if(ImmediateUnlink) unlink(fn); - if (fd < 0) + if (fd < 0) { _error->Errno("GetTempFile",_("Unable to mkstemp %s"), fn); return NULL; } - if (!Fd->OpenDescriptor(fd, FileFd::WriteOnly, FileFd::None, true)) + if (!Fd->OpenDescriptor(fd, FileFd::ReadWrite, FileFd::None, true)) { _error->Errno("GetTempFile",_("Unable to write to %s"),fn); return NULL; } - return Fd; } /*}}}*/ @@ -2175,11 +2230,14 @@ bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)/ { close(Pipe[1]); fd = Pipe[0]; - } else if(Mode == FileFd::WriteOnly) + } + 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; @@ -2219,22 +2277,32 @@ bool DropPrivileges() /*{{{*/ 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"); - - // the seteuid() is probably uneeded (at least thats what the linux - // man-page says about setuid(2)) but we cargo culted it anyway if (seteuid(pw->pw_uid) != 0) return _error->Errno("seteuid", "Failed to seteuid"); +#endif // Verify that the user has only a single group, and the correct one gid_t groups[1];