syscalls.cc

cygwin, 著名的在win32下模拟unix操作系统的东东

      (lnk_suffix = strrchr (real_new.get_win32 (), '.')))
     *lnk_suffix = '\0';

  if (!MoveFile (real_old, real_new))
    res = -1;

  if (res == 0 || (GetLastError () != ERROR_ALREADY_EXISTS
		   && GetLastError () != ERROR_FILE_EXISTS))
    goto done;

  if (wincap.has_move_file_ex ())
    {
      if (MoveFileEx (real_old.get_win32 (), real_new.get_win32 (),
		      MOVEFILE_REPLACE_EXISTING))
	res = 0;
    }
  else
    {
      syscall_printf ("try win95 hack");
      for (int i = 0; i < 2; i++)
	{
	  if (!DeleteFileA (real_new.get_win32 ()) &&
	      GetLastError () != ERROR_FILE_NOT_FOUND)
	    {
	      syscall_printf ("deleting %s to be paranoid",
			      real_new.get_win32 ());
	      break;
	    }
	  else if (MoveFile (real_old.get_win32 (), real_new.get_win32 ()))
	    {
	      res = 0;
	      break;
	    }
	}
    }

done:
  if (res)
    {
      __seterrno ();
      /* Reset R/O attributes if neccessary. */
      if (real_new.has_attribute (FILE_ATTRIBUTE_READONLY))
	SetFileAttributes (real_new, real_new);
    }
  else
    {
      /* make the new file have the permissions of the old one */
      DWORD attr = real_old;
#ifdef HIDDEN_DOT_FILES
      char *c = strrchr (real_old.get_win32 (), '\\');
      if ((c && c[1] == '.') || *real_old.get_win32 () == '.')
	attr &= ~FILE_ATTRIBUTE_HIDDEN;
      c = strrchr (real_new.get_win32 (), '\\');
      if ((c && c[1] == '.') || *real_new.get_win32 () == '.')
	attr |= FILE_ATTRIBUTE_HIDDEN;
#endif
      SetFileAttributes (real_new, attr);

      /* Shortcut hack, No. 2, part 2 */
      /* if the new filename was an existing shortcut, remove it now if the
	 new filename is equal to the shortcut name without .lnk suffix. */
      if (lnk_suffix)
	{
	  *lnk_suffix = '.';
	  DeleteFile (real_new);
	}
    }

  syscall_printf ("%d = rename (%s, %s)", res, (char *) real_old,
		  (char *) real_new);

  return res;
}

extern "C" int
system (const char *cmdstring)
{
  if (check_null_empty_str_errno (cmdstring))
    return -1;

  sigframe thisframe (mainthread);
  int res;
  const char* command[4];
  _sig_func_ptr oldint, oldquit;
  sigset_t child_block, old_mask;

  if (cmdstring == (const char *) NULL)
	return 1;

  oldint = signal (SIGINT, SIG_IGN);
  oldquit = signal (SIGQUIT, SIG_IGN);
  sigemptyset (&child_block);
  sigaddset (&child_block, SIGCHLD);
  (void) sigprocmask (SIG_BLOCK, &child_block, &old_mask);

  command[0] = "sh";
  command[1] = "-c";
  command[2] = cmdstring;
  command[3] = (const char *) NULL;

  if ((res = spawnvp (_P_WAIT, "sh", command)) == -1)
    {
      // when exec fails, return value should be as if shell
      // executed exit (127)
      res = 127;
    }

  signal (SIGINT, oldint);
  signal (SIGQUIT, oldquit);
  (void) sigprocmask (SIG_SETMASK, &old_mask, 0);
  return res;
}

extern "C" int
setdtablesize (int size)
{
  if (size <= (int)cygheap->fdtab.size || cygheap->fdtab.extend (size - cygheap->fdtab.size))
    return 0;

  return -1;
}

extern "C" int
getdtablesize ()
{
  return cygheap->fdtab.size > OPEN_MAX ? cygheap->fdtab.size : OPEN_MAX;
}

extern "C" size_t
getpagesize ()
{
  if (!system_info.dwPageSize)
    GetSystemInfo (&system_info);
  return (int) system_info.dwPageSize;
}

static int
check_posix_perm (const char *fname, int v)
{
  extern int allow_ntea, allow_ntsec, allow_smbntsec;

  /* Windows 95/98/ME don't support file system security at all. */
  if (!wincap.has_security ())
    return 0;

  /* ntea is ok for supporting permission bits but it doesn't support
     full POSIX security settings. */
  if (v == _PC_POSIX_PERMISSIONS && allow_ntea)
    return 1;

  if (!allow_ntsec)
    return 0;

  char *root = rootdir (strcpy ((char *)alloca (strlen (fname)), fname));

  if (!allow_smbntsec
      && ((root[0] == '\\' && root[1] == '\\')
	  || GetDriveType (root) == DRIVE_REMOTE))
    return 0;

  DWORD vsn, len, flags;
  if (!GetVolumeInformation (root, NULL, 0, &vsn, &len, &flags, NULL, 16))
    {
      __seterrno ();
      return 0;
    }

  return (flags & FS_PERSISTENT_ACLS) ? 1 : 0;
}

/* FIXME: not all values are correct... */
extern "C" long int
fpathconf (int fd, int v)
{
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return -1;
  switch (v)
    {
    case _PC_LINK_MAX:
      return _POSIX_LINK_MAX;
    case _PC_MAX_CANON:
    case _PC_MAX_INPUT:
      if (isatty (fd))
	return _POSIX_MAX_CANON;
      else
	{
	  set_errno (EBADF);
	  return -1;
	}
    case _PC_NAME_MAX:
    case _PC_PATH_MAX:
      return PATH_MAX;
    case _PC_PIPE_BUF:
      return PIPE_BUF;
    case _PC_CHOWN_RESTRICTED:
    case _PC_NO_TRUNC:
      return -1;
    case _PC_VDISABLE:
      if (cfd->is_tty ())
	return -1;
      else
	{
	  set_errno (EBADF);
	  return -1;
	}
    case _PC_POSIX_PERMISSIONS:
    case _PC_POSIX_SECURITY:
      if (cfd->get_device () == FH_DISK)
	return check_posix_perm (cfd->get_win32_name (), v);
      set_errno (EINVAL);
      return -1;
    default:
      set_errno (EINVAL);
      return -1;
    }
}

extern "C" long int
pathconf (const char *file, int v)
{
  switch (v)
    {
    case _PC_PATH_MAX:
      if (check_null_empty_str_errno (file))
	  return -1;
      return PATH_MAX - strlen (file);
    case _PC_NAME_MAX:
      return PATH_MAX;
    case _PC_LINK_MAX:
      return _POSIX_LINK_MAX;
    case _PC_MAX_CANON:
    case _PC_MAX_INPUT:
      return _POSIX_MAX_CANON;
    case _PC_PIPE_BUF:
      return PIPE_BUF;
    case _PC_CHOWN_RESTRICTED:
    case _PC_NO_TRUNC:
      return -1;
    case _PC_VDISABLE:
      return -1;
    case _PC_POSIX_PERMISSIONS:
    case _PC_POSIX_SECURITY:
      {
	path_conv full_path (file, PC_SYM_FOLLOW | PC_FULL);
	if (full_path.error)
	  {
	    set_errno (full_path.error);
	    return -1;
	  }
	if (full_path.is_device ())
	  {
	    set_errno (EINVAL);
	    return -1;
	  }
	return check_posix_perm (full_path, v);
      }
    default:
      set_errno (EINVAL);
      return -1;
    }
}

extern "C" char *
ttyname (int fd)
{
  cygheap_fdget cfd (fd);
  if (cfd < 0 || !cfd->is_tty ())
    {
      return 0;
    }
  return (char *) (cfd->ttyname ());
}

extern "C" char *
ctermid (char *str)
{
  static NO_COPY char buf[16];
  if (str == NULL)
    str = buf;
  if (!real_tty_attached (myself))
    strcpy (str, "/dev/conin");
  else
    __small_sprintf (str, "/dev/tty%d", myself->ctty);
  return str;
}

/* Tells stdio if it should do the cr/lf conversion for this file */
extern "C" int
_cygwin_istext_for_stdio (int fd)
{
  syscall_printf ("_cygwin_istext_for_stdio (%d)", fd);
  if (CYGWIN_VERSION_OLD_STDIO_CRLF_HANDLING)
    {
      syscall_printf (" _cifs: old API");
      return 0; /* we do it for old apps, due to getc/putc macros */
    }

  cygheap_fdget cfd (fd, false, false);
  if (cfd < 0)
    {
      syscall_printf (" _cifs: fd not open");
      return 0;
    }

  if (cfd->get_device () != FH_DISK)
    {
      syscall_printf (" _cifs: fd not disk file");
      return 0;
    }

  if (cfd->get_w_binary () || cfd->get_r_binary ())
    {
      syscall_printf (" _cifs: get_*_binary");
      return 0;
    }

  syscall_printf ("_cygwin_istext_for_stdio says yes");
  return 1;
}

/* internal newlib function */
extern "C" int _fwalk (struct _reent *ptr, int (*function) (FILE *));

static int setmode_mode;
static int setmode_file;

static int
setmode_helper (FILE *f)
{
  if (fileno (f) != setmode_file)
    return 0;
  syscall_printf ("setmode: file was %s now %s",
		 f->_flags & __SCLE ? "text" : "raw",
		 setmode_mode & O_TEXT ? "text" : "raw");
  if (setmode_mode & O_TEXT)
    f->_flags |= __SCLE;
  else
    f->_flags &= ~__SCLE;
  return 0;
}

extern "C" int
getmode (int fd)
{
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return -1;

  return cfd->get_flags () & (O_BINARY | O_TEXT);
}

/* Set a file descriptor into text or binary mode, returning the
   previous mode.  */

extern "C" int
setmode (int fd, int mode)
{
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return -1;
  if (mode != O_BINARY  && mode != O_TEXT && mode != 0)
    {
      set_errno (EINVAL);
      return -1;
    }

  /* Note that we have no way to indicate the case that writes are
     binary but not reads, or vice-versa.  These cases can arise when
     using the tty or console interface.  People using those
     interfaces should not use setmode.  */

  int res;
  if (cfd->get_w_binary () && cfd->get_r_binary ())
    res = O_BINARY;
  else if (cfd->get_w_binset () && cfd->get_r_binset ())
    res = O_TEXT;	/* Specifically set O_TEXT */
  else
    res = 0;

  if (!mode)
    cfd->reset_to_open_binmode ();
  else
    cfd->set_flags ((cfd->get_flags () & ~(O_TEXT | O_BINARY)) | mode);

  if (_cygwin_istext_for_stdio (fd))
    setmode_mode = O_TEXT;
  else
    setmode_mode = O_BINARY;
  setmode_file = fd;
  _fwalk (_REENT, setmode_helper);

  syscall_printf ("setmode (%d<%s>, %p) returns %s", fd, cfd->get_name (),
		  mode, res & O_TEXT ? "text" : "binary");
  return res;
}

extern "C" int
ftruncate64 (int fd, __off64_t length)
{
  sigframe thisframe (mainthread);
  int res = -1;

  if (length < 0)
    set_errno (EINVAL);
  else
    {
      cygheap_fdget cfd (fd);
      if (cfd >= 0)
	{
	  HANDLE h = cygheap->fdtab[fd]->get_handle ();

	  if (cfd->get_handle ())
	    {
	      /* remember curr file pointer location */
	      __off64_t prev_loc = cfd->lseek (0, SEEK_CUR);

	      cfd->lseek (length, SEEK_SET);
	      if (!SetEndOfFile (h))
		__seterrno ();
	      else
		res = 0;

	      /* restore original file pointer location */
	      cfd->lseek (prev_loc, SEEK_SET);
	    }
	}
    }

  syscall_printf ("%d = ftruncate (%d, %d)", res, fd, length);
  return res;
}

/* ftruncate: P96 5.6.7.1 */
extern "C" int
ftruncate (int fd, __off32_t length)
{
  return ftruncate64 (fd, (__off64_t)length);
}

/* truncate: Provided by SVR4 and 4.3+BSD.  Not part of POSIX.1 or XPG3 */
extern "C" int
truncate64 (const char *pathname, __off64_t length)
{
  sigframe thisframe (mainthread);
  int fd;
  int res = -1;

  fd = open (pathname, O_RDWR);

  if (fd == -1)
    set_errno (EBADF);
  else
    {
      res = ftruncate64 (fd, length);
      close (fd);
    }
  syscall_printf ("%d = truncate (%s, %d)", res, pathname, length);

  return res;
}

/* truncate: Provided by SVR4 and 4.3+BSD.  Not part of POSIX.1 or XPG3 */
extern "C" int
truncate (const char *pathname, __off32_t length)
{
  return truncate64 (pathname, (__off64_t)length);
}

extern "C" long
get_osfhandle (int fd)
{
  long res;

  cygheap_fdget cfd (fd);
  if (cfd >= 0)
    res = (long) cfd->get_handle ();
  else
    res = -1;

  syscall_printf ("%d = get_osfhandle (%d)", res, fd);
  return res;
}

extern "C" int
statfs (const char *fname, struct statfs *sfs)
{
  sigframe thisframe (mainthread);
  if (!sfs)
    {
      set_errno (EFAULT);
      return -1;
    }

  path_conv full_path (fname, PC_SYM_FOLLOW | PC_FULL);
  char *root = rootdir (full_path);

  syscall_printf ("statfs %s", root);

  DWORD spc, bps, freec, totalc;

  if (!GetDiskFreeSpace (root, &spc, &bps, &freec, &totalc))
    {
      __seterrno ();
      return -1;
    }

  DWORD vsn, maxlen, flags;

  if (!GetVolumeInformation (root, NULL, 0, &vsn, &maxlen, &flags, NULL, 0))
    {
      __seterrno ();
      return -1;
    }
  sfs->f_type = flags;
  sfs->f_bsize = spc*bps;
  sfs->f_blocks = totalc;
  sfs->f_bfree = sfs->f_bavail = freec;
  sfs->f_files = -1;
  sfs->f_ffree = -1;
  sfs->f_fsid = vsn;
  sfs->f_namelen = maxlen;
  return 0;
}

extern "C" int
fstatfs (int fd, struct statfs *sfs)
{
  sigframe thisframe (mainthread);
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return -1;
  return statfs (cfd->get_name (), sfs);
}

/* setpgid: POSIX 4.3.3.1 */
extern "C" int
setpgid (pid_t pid, pid_t pgid)
{
  sigframe thisframe (mainthread);
  int res = -1;
  if (pid == 0)
    pid = getpid ();
  if (pgid == 0)
    pgid = pid;

  if (pgid < 0)
    {
      set_errno (EINVAL);
      goto out;
    }
  else
    {
      pinfo p (pid);
      if (!p)
	{
	  set_errno (ESRCH);
	  goto out;
	}
      /* A process may only change the process group of itself and its children */
      if (p == myself || p->ppid == myself->pid)
	{
	  p->pgid = pgid;
	  if (p->pid != p->pgid)
	    p->set_has_pgid_children (0);
	  res = 0;
	}
      else
	{
	  set_errno (EPERM);
	  goto out;
	}
    }
out:
  syscall_printf ("pid %d, pgid %d, res %d", pid, pgid, res);
  return res;
}

extern "C" pid_t
getpgid (pid_t pid)
{
  sigframe thisframe (mainthread);
  if (pid == 0)
    pid = getpid ();

  pinfo p (pid);
  if (p == 0)
    {
      set_errno (ESRCH);
      return -1;
    }
  return p->pgid;
}

extern "C" int
setpgrp (void)
{
  sigframe thisframe (mainthread);
  return setpgid (0, 0);
}

extern "C" pid_t
getpgrp (void)
{
  sigframe thisframe (mainthread);
  return getpgid (0);
}

extern "C" char *
ptsname (int fd)
{
  sigframe thisframe (mainthread);
  cygheap_fdget cfd (fd);
  if (cfd < 0)
    return 0;
  return (char *) (cfd->ptsname ());
}

/* FIXME: what is this? */
extern "C" int __declspec(dllexport)
regfree ()
{
  return 0;
}

/* mknod was the call to create directories before the introduction
   of mkdir in 4.2BSD and SVR3.  Use of mknod required superuser privs
   so the mkdir command had to be setuid root.
   Although mknod hasn't been implemented yet, some GNU tools (e.g. the
   fileutils) assume its existence so we must provide a stub that always
   fails. */
extern "C" int
mknod (const char *_path, mode_t mode, dev_t dev)
{
  set_errno (ENOSYS);
  return -1;
}

extern "C" int
mkfifo (const char *_path, mode_t mode)
{
  set_errno (ENOSYS);
  return -1;
}

/* seteuid: standards? */
extern "C" int
seteuid32 (__uid32_t uid)
{