Initial revision

4 files changed, 1366 insertions, 0 deletions

diff --git a/lib/DISTFILES b/lib/DISTFILES
new file mode 100644
index 0000000..65bab61
--- /dev/null
+++ b/lib/DISTFILES
@@ -0,0 +1,3 @@
+rmt.h
+rtapelib.c
+system.h
diff --git a/lib/rmt.h b/lib/rmt.h
new file mode 100644
index 0000000..1fd2f29
--- /dev/null
+++ b/lib/rmt.h
@@ -0,0 +1,99 @@
+/* Definitions for communicating with a remote tape drive.
+
+   Copyright (C) 1988, 1992, 1996, 1997, 2001, 2003, 2004 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+extern char *rmt_command;
+extern char *rmt_dev_name__;
+
+int rmt_open__ (const char *, int, int, const char *);
+int rmt_close__ (int);
+size_t rmt_read__ (int, char *, size_t);
+size_t rmt_write__ (int, char *, size_t);
+off_t rmt_lseek__ (int, off_t, int);
+int rmt_ioctl__ (int, int, char *);
+
+extern bool force_local_option;
+
+/* A filename is remote if it contains a colon not preceded by a slash,
+   to take care of `/:/' which is a shorthand for `/.../<CELL-NAME>/fs'
+   on machines running OSF's Distributing Computing Environment (DCE) and
+   Distributed File System (DFS).  However, when --force-local, a
+   filename is never remote.  */
+
+#define _remdev(dev_name) \
+  (!force_local_option && (rmt_dev_name__ = strchr (dev_name, ':')) \
+   && rmt_dev_name__ > (dev_name) \
+   && ! memchr (dev_name, '/', rmt_dev_name__ - (dev_name)))
+
+#define _isrmt(fd) \
+  ((fd) >= __REM_BIAS)
+
+#define __REM_BIAS (1 << 30)
+
+#ifndef O_CREAT
+# define O_CREAT 01000
+#endif
+
+#define rmtopen(dev_name, oflag, mode, command) \
+  (_remdev (dev_name) ? rmt_open__ (dev_name, oflag, __REM_BIAS, command) \
+   : open (dev_name, oflag, mode))
+
+#define rmtaccess(dev_name, amode) \
+  (_remdev (dev_name) ? 0 : access (dev_name, amode))
+
+#define rmtstat(dev_name, buffer) \
+  (_remdev (dev_name) ? (errno = EOPNOTSUPP), -1 : stat (dev_name, buffer))
+
+#define rmtcreat(dev_name, mode, command) \
+   (_remdev (dev_name) \
+    ? rmt_open__ (dev_name, 1 | O_CREAT, __REM_BIAS, command) \
+    : creat (dev_name, mode))
+
+#define rmtlstat(dev_name, muffer) \
+  (_remdev (dev_name) ? (errno = EOPNOTSUPP), -1 : lstat (dev_name, buffer))
+
+#define rmtread(fd, buffer, length) \
+  (_isrmt (fd) ? rmt_read__ (fd - __REM_BIAS, buffer, length) \
+   : safe_read (fd, buffer, length))
+
+#define rmtwrite(fd, buffer, length) \
+  (_isrmt (fd) ? rmt_write__ (fd - __REM_BIAS, buffer, length) \
+   : full_write (fd, buffer, length))
+
+#define rmtlseek(fd, offset, where) \
+  (_isrmt (fd) ? rmt_lseek__ (fd - __REM_BIAS, offset, where) \
+   : lseek (fd, offset, where))
+
+#define rmtclose(fd) \
+  (_isrmt (fd) ? rmt_close__ (fd - __REM_BIAS) : close (fd))
+
+#define rmtioctl(fd, request, argument) \
+  (_isrmt (fd) ? rmt_ioctl__ (fd - __REM_BIAS, request, argument) \
+   : ioctl (fd, request, argument))
+
+#define rmtdup(fd) \
+  (_isrmt (fd) ? (errno = EOPNOTSUPP), -1 : dup (fd))
+
+#define rmtfstat(fd, buffer) \
+  (_isrmt (fd) ? (errno = EOPNOTSUPP), -1 : fstat (fd, buffer))
+
+#define rmtfcntl(cd, command, argument) \
+  (_isrmt (fd) ? (errno = EOPNOTSUPP), -1 : fcntl (fd, command, argument))
+
+#define rmtisatty(fd) \
+  (_isrmt (fd) ? 0 : isatty (fd))
diff --git a/lib/rtapelib.c b/lib/rtapelib.c
new file mode 100644
index 0000000..0e499b6
--- /dev/null
+++ b/lib/rtapelib.c
@@ -0,0 +1,740 @@
+/* Functions for communicating with a remote tape drive.
+
+   Copyright 1988, 1992, 1994, 1996, 1997, 1999, 2000, 2001, 2004 Free
+   Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* The man page rmt(8) for /etc/rmt documents the remote mag tape protocol
+   which rdump and rrestore use.  Unfortunately, the man page is *WRONG*.
+   The author of the routines I'm including originally wrote his code just
+   based on the man page, and it didn't work, so he went to the rdump source
+   to figure out why.  The only thing he had to change was to check for the
+   'F' return code in addition to the 'E', and to separate the various
+   arguments with \n instead of a space.  I personally don't think that this
+   is much of a problem, but I wanted to point it out. -- Arnold Robbins
+
+   Originally written by Jeff Lee, modified some by Arnold Robbins.  Redone
+   as a library that can replace open, read, write, etc., by Fred Fish, with
+   some additional work by Arnold Robbins.  Modified to make all rmt* calls
+   into macros for speed by Jay Fenlason.  Use -DWITH_REXEC for rexec
+   code, courtesy of Dan Kegel.  */
+
+#include "system.h"
+#include <safe-read.h>
+#include <full-write.h>
+
+/* Try hard to get EOPNOTSUPP defined.  486/ISC has it in net/errno.h,
+   3B2/SVR3 has it in sys/inet.h.  Otherwise, like on MSDOS, use EINVAL.  */
+
+#ifndef EOPNOTSUPP
+# if HAVE_NET_ERRNO_H
+#  include <net/errno.h>
+# endif
+# if HAVE_SYS_INET_H
+#  include <sys/inet.h>
+# endif
+# ifndef EOPNOTSUPP
+#  define EOPNOTSUPP EINVAL
+# endif
+#endif
+
+#include <signal.h>
+
+#if HAVE_NETDB_H
+# include <netdb.h>
+#endif
+
+#include <rmt.h>
+#include <localedir.h>
+
+/* Exit status if exec errors.  */
+#define EXIT_ON_EXEC_ERROR 128
+
+/* FIXME: Size of buffers for reading and writing commands to rmt.  */
+#define COMMAND_BUFFER_SIZE 64
+
+#ifndef RETSIGTYPE
+# define RETSIGTYPE void
+#endif
+
+/* FIXME: Maximum number of simultaneous remote tape connections.  */
+#define MAXUNIT	4
+
+#define	PREAD 0			/* read  file descriptor from pipe() */
+#define	PWRITE 1		/* write file descriptor from pipe() */
+
+/* Return the parent's read side of remote tape connection Fd.  */
+#define READ_SIDE(Fd) (from_remote[Fd][PREAD])
+
+/* Return the parent's write side of remote tape connection Fd.  */
+#define WRITE_SIDE(Fd) (to_remote[Fd][PWRITE])
+
+/* The pipes for receiving data from remote tape drives.  */
+static int from_remote[MAXUNIT][2] = {{-1, -1}, {-1, -1}, {-1, -1}, {-1, -1}};
+
+/* The pipes for sending data to remote tape drives.  */
+static int to_remote[MAXUNIT][2] = {{-1, -1}, {-1, -1}, {-1, -1}, {-1, -1}};
+
+char *rmt_command = DEFAULT_RMT_COMMAND;
+
+/* Temporary variable used by macros in rmt.h.  */
+char *rmt_dev_name__;
+
+/* If true, always consider file names to be local, even if they contain
+   colons */
+bool force_local_option;
+
+
+
+/* Close remote tape connection HANDLE, and reset errno to ERRNO_VALUE.  */
+static void
+_rmt_shutdown (int handle, int errno_value)
+{
+  close (READ_SIDE (handle));
+  close (WRITE_SIDE (handle));
+  READ_SIDE (handle) = -1;
+  WRITE_SIDE (handle) = -1;
+  errno = errno_value;
+}
+
+/* Attempt to perform the remote tape command specified in BUFFER on
+   remote tape connection HANDLE.  Return 0 if successful, -1 on
+   error.  */
+static int
+do_command (int handle, const char *buffer)
+{
+  /* Save the current pipe handler and try to make the request.  */
+
+  size_t length = strlen (buffer);
+  RETSIGTYPE (*pipe_handler) () = signal (SIGPIPE, SIG_IGN);
+  ssize_t written = full_write (WRITE_SIDE (handle), buffer, length);
+  signal (SIGPIPE, pipe_handler);
+
+  if (written == length)
+    return 0;
+
+  /* Something went wrong.  Close down and go home.  */
+
+  _rmt_shutdown (handle, EIO);
+  return -1;
+}
+
+static char *
+get_status_string (int handle, char *command_buffer)
+{
+  char *cursor;
+  int counter;
+
+  /* Read the reply command line.  */
+
+  for (counter = 0, cursor = command_buffer;
+       counter < COMMAND_BUFFER_SIZE;
+       counter++, cursor++)
+    {
+      if (safe_read (READ_SIDE (handle), cursor, 1) != 1)
+	{
+	  _rmt_shutdown (handle, EIO);
+	  return 0;
+	}
+      if (*cursor == '\n')
+	{
+	  *cursor = '\0';
+	  break;
+	}
+    }
+
+  if (counter == COMMAND_BUFFER_SIZE)
+    {
+      _rmt_shutdown (handle, EIO);
+      return 0;
+    }
+
+  /* Check the return status.  */
+
+  for (cursor = command_buffer; *cursor; cursor++)
+    if (*cursor != ' ')
+      break;
+
+  if (*cursor == 'E' || *cursor == 'F')
+    {
+      /* Skip the error message line.  */
+
+      /* FIXME: there is better to do than merely ignoring error messages
+	 coming from the remote end.  Translate them, too...  */
+
+      {
+	char character;
+
+	while (safe_read (READ_SIDE (handle), &character, 1) == 1)
+	  if (character == '\n')
+	    break;
+      }
+
+      errno = atoi (cursor + 1);
+
+      if (*cursor == 'F')
+	_rmt_shutdown (handle, errno);
+
+      return 0;
+    }
+
+  /* Check for mis-synced pipes.  */
+
+  if (*cursor != 'A')
+    {
+      _rmt_shutdown (handle, EIO);
+      return 0;
+    }
+
+  /* Got an `A' (success) response.  */
+
+  return cursor + 1;
+}
+
+/* Read and return the status from remote tape connection HANDLE.  If
+   an error occurred, return -1 and set errno.  */
+static long int
+get_status (int handle)
+{
+  char command_buffer[COMMAND_BUFFER_SIZE];
+  const char *status = get_status_string (handle, command_buffer);
+  if (status)
+    {
+      long int result = atol (status);
+      if (0 <= result)
+	return result;
+      errno = EIO;
+    }
+  return -1;
+}
+
+static off_t
+get_status_off (int handle)
+{
+  char command_buffer[COMMAND_BUFFER_SIZE];
+  const char *status = get_status_string (handle, command_buffer);
+
+  if (! status)
+    return -1;
+  else
+    {
+      /* Parse status, taking care to check for overflow.
+	 We can't use standard functions,
+	 since off_t might be longer than long.  */
+
+      off_t count = 0;
+      int negative;
+
+      for (;  *status == ' ' || *status == '\t';  status++)
+	continue;
+
+      negative = *status == '-';
+      status += negative || *status == '+';
+
+      for (;;)
+	{
+	  int digit = *status++ - '0';
+	  if (9 < (unsigned) digit)
+	    break;
+	  else
+	    {
+	      off_t c10 = 10 * count;
+	      off_t nc = negative ? c10 - digit : c10 + digit;
+	      if (c10 / 10 != count || (negative ? c10 < nc : nc < c10))
+		return -1;
+	      count = nc;
+	    }
+	}
+
+      return count;
+    }
+}
+
+#if WITH_REXEC
+
+/* Execute /etc/rmt as user USER on remote system HOST using rexec.
+   Return a file descriptor of a bidirectional socket for stdin and
+   stdout.  If USER is zero, use the current username.
+
+   By default, this code is not used, since it requires that the user
+   have a .netrc file in his/her home directory, or that the
+   application designer be willing to have rexec prompt for login and
+   password info.  This may be unacceptable, and .rhosts files for use
+   with rsh are much more common on BSD systems.  */
+static int
+_rmt_rexec (char *host, char *user)
+{
+  int saved_stdin = dup (STDIN_FILENO);
+  int saved_stdout = dup (STDOUT_FILENO);
+  struct servent *rexecserv;
+  int result;
+
+  /* When using cpio -o < filename, stdin is no longer the tty.  But the
+     rexec subroutine reads the login and the passwd on stdin, to allow
+     remote execution of the command.  So, reopen stdin and stdout on
+     /dev/tty before the rexec and give them back their original value
+     after.  */
+
+  if (! freopen ("/dev/tty", "r", stdin))
+    freopen ("/dev/null", "r", stdin);
+  if (! freopen ("/dev/tty", "w", stdout))
+    freopen ("/dev/null", "w", stdout);
+
+  if (rexecserv = getservbyname ("exec", "tcp"), !rexecserv)
+    error (EXIT_ON_EXEC_ERROR, 0, _("exec/tcp: Service not available"));
+
+  result = rexec (&host, rexecserv->s_port, user, 0, rmt_command, 0);
+  if (fclose (stdin) == EOF)
+    error (0, errno, _("stdin"));
+  fdopen (saved_stdin, "r");
+  if (fclose (stdout) == EOF)
+    error (0, errno, _("stdout"));
+  fdopen (saved_stdout, "w");
+
+  return result;
+}
+
+#endif /* WITH_REXEC */
+
+/* Place into BUF a string representing OFLAG, which must be suitable
+   as argument 2 of `open'.  BUF must be large enough to hold the
+   result.  This function should generate a string that decode_oflag
+   can parse.  */
+static void
+encode_oflag (char *buf, int oflag)
+{
+  sprintf (buf, "%d ", oflag);
+
+  switch (oflag & O_ACCMODE)
+    {
+    case O_RDONLY: strcat (buf, "O_RDONLY"); break;
+    case O_RDWR: strcat (buf, "O_RDWR"); break;
+    case O_WRONLY: strcat (buf, "O_WRONLY"); break;
+    default: abort ();
+    }
+
+#ifdef O_APPEND
+  if (oflag & O_APPEND) strcat (buf, "|O_APPEND");
+#endif
+  if (oflag & O_CREAT) strcat (buf, "|O_CREAT");
+#ifdef O_DSYNC
+  if (oflag & O_DSYNC) strcat (buf, "|O_DSYNC");
+#endif
+  if (oflag & O_EXCL) strcat (buf, "|O_EXCL");
+#ifdef O_LARGEFILE
+  if (oflag & O_LARGEFILE) strcat (buf, "|O_LARGEFILE");
+#endif
+#ifdef O_NOCTTY
+  if (oflag & O_NOCTTY) strcat (buf, "|O_NOCTTY");
+#endif
+#ifdef O_NONBLOCK
+  if (oflag & O_NONBLOCK) strcat (buf, "|O_NONBLOCK");
+#endif
+#ifdef O_RSYNC
+  if (oflag & O_RSYNC) strcat (buf, "|O_RSYNC");
+#endif
+#ifdef O_SYNC
+  if (oflag & O_SYNC) strcat (buf, "|O_SYNC");
+#endif
+  if (oflag & O_TRUNC) strcat (buf, "|O_TRUNC");
+}
+
+/* Open a file (a magnetic tape device?) on the system specified in
+   FILE_NAME, as the given user. FILE_NAME has the form `[USER@]HOST:FILE'.
+   OPEN_MODE is O_RDONLY, O_WRONLY, etc.  If successful, return the
+   remote pipe number plus BIAS.  REMOTE_SHELL may be overridden.  On
+   error, return -1.  */
+int
+rmt_open__ (const char *file_name, int open_mode, int bias, 
+            const char *remote_shell)
+{
+  int remote_pipe_number;	/* pseudo, biased file descriptor */
+  char *file_name_copy;		/* copy of file_name string */
+  char *remote_host;		/* remote host name */
+  char *remote_file;		/* remote file name (often a device) */
+  char *remote_user;		/* remote user name */
+
+  /* Find an unused pair of file descriptors.  */
+
+  for (remote_pipe_number = 0;
+       remote_pipe_number < MAXUNIT;
+       remote_pipe_number++)
+    if (READ_SIDE (remote_pipe_number) == -1
+	&& WRITE_SIDE (remote_pipe_number) == -1)
+      break;
+
+  if (remote_pipe_number == MAXUNIT)
+    {
+      errno = EMFILE;
+      return -1;
+    }
+
+  /* Pull apart the system and device, and optional user.  */
+
+  {
+    char *cursor;
+
+    file_name_copy = xstrdup (file_name);
+    remote_host = file_name_copy;
+    remote_user = 0;
+    remote_file = 0;
+
+    for (cursor = file_name_copy; *cursor; cursor++)
+      switch (*cursor)
+	{
+	default:
+	  break;
+
+	case '\n':
+	  /* Do not allow newlines in the file_name, since the protocol
+	     uses newline delimiters.  */
+	  free (file_name_copy);
+	  errno = ENOENT;
+	  return -1;
+
+	case '@':
+	  if (!remote_user)
+	    {
+	      remote_user = remote_host;
+	      *cursor = '\0';
+	      remote_host = cursor + 1;
+	    }
+	  break;
+
+	case ':':
+	  if (!remote_file)
+	    {
+	      *cursor = '\0';
+	      remote_file = cursor + 1;
+	    }
+	  break;
+	}
+  }
+
+  /* FIXME: Should somewhat validate the decoding, here.  */
+
+  if (remote_user && *remote_user == '\0')
+    remote_user = 0;
+
+#if WITH_REXEC
+
+  /* Execute the remote command using rexec.  */
+
+  READ_SIDE (remote_pipe_number) = _rmt_rexec (remote_host, remote_user);
+  if (READ_SIDE (remote_pipe_number) < 0)
+    {
+      int e = errno;
+      free (file_name_copy);
+      errno = e;
+      return -1;
+    }
+
+  WRITE_SIDE (remote_pipe_number) = READ_SIDE (remote_pipe_number);
+
+#else /* not WITH_REXEC */
+  {
+    const char *remote_shell_basename;
+    pid_t status;
+
+    /* Identify the remote command to be executed.  */
+
+    if (!remote_shell)
+      {
+#ifdef REMOTE_SHELL
+	remote_shell = REMOTE_SHELL;
+#else
+	free (file_name_copy);
+	errno = EIO;
+	return -1;
+#endif
+      }
+    remote_shell_basename = base_name (remote_shell);
+
+    /* Set up the pipes for the `rsh' command, and fork.  */
+
+    if (pipe (to_remote[remote_pipe_number]) == -1
+	|| pipe (from_remote[remote_pipe_number]) == -1)
+      {
+	int e = errno;
+	free (file_name_copy);
+	errno = e;
+	return -1;
+      }
+
+    status = fork ();
+    if (status == -1)
+      {
+	int e = errno;
+	free (file_name_copy);
+	errno = e;
+	return -1;
+      }
+
+    if (status == 0)
+      {
+	/* Child.  */
+
+	close (STDIN_FILENO);
+	dup (to_remote[remote_pipe_number][PREAD]);
+	close (to_remote[remote_pipe_number][PREAD]);
+	close (to_remote[remote_pipe_number][PWRITE]);
+
+	close (STDOUT_FILENO);
+	dup (from_remote[remote_pipe_number][PWRITE]);
+	close (from_remote[remote_pipe_number][PREAD]);
+	close (from_remote[remote_pipe_number][PWRITE]);
+
+	sys_reset_uid_gid ();
+
+	if (remote_user)
+	  execl (remote_shell, remote_shell_basename, remote_host,
+		 "-l", remote_user, rmt_command, (char *) 0);
+	else
+	  execl (remote_shell, remote_shell_basename, remote_host,
+		 rmt_command, (char *) 0);
+
+	/* Bad problems if we get here.  */
+
+	/* In a previous version, _exit was used here instead of exit.  */
+	error (EXIT_ON_EXEC_ERROR, errno, _("Cannot execute remote shell"));
+      }
+
+    /* Parent.  */
+
+    close (from_remote[remote_pipe_number][PWRITE]);
+    close (to_remote[remote_pipe_number][PREAD]);
+  }
+#endif /* not WITH_REXEC */
+
+  /* Attempt to open the tape device.  */
+
+  {
+    size_t remote_file_len = strlen (remote_file);
+    char *command_buffer = xmalloc (remote_file_len + 1000);
+    sprintf (command_buffer, "O%s\n", remote_file);
+    encode_oflag (command_buffer + remote_file_len + 2, open_mode);
+    strcat (command_buffer, "\n");
+    if (do_command (remote_pipe_number, command_buffer) == -1
+	|| get_status (remote_pipe_number) == -1)
+      {
+	int e = errno;
+	free (command_buffer);
+	free (file_name_copy);
+	_rmt_shutdown (remote_pipe_number, e);
+	return -1;
+      }
+    free (command_buffer);
+  }
+
+  free (file_name_copy);
+  return remote_pipe_number + bias;
+}
+
+/* Close remote tape connection HANDLE and shut down.  Return 0 if
+   successful, -1 on error.  */
+int
+rmt_close__ (int handle)
+{
+  long int status;
+
+  if (do_command (handle, "C\n") == -1)
+    return -1;
+
+  status = get_status (handle);
+  _rmt_shutdown (handle, errno);
+  return status;
+}
+
+/* Read up to LENGTH bytes into BUFFER from remote tape connection HANDLE.
+   Return the number of bytes read on success, SAFE_READ_ERROR on error.  */
+size_t
+rmt_read__ (int handle, char *buffer, size_t length)
+{
+  char command_buffer[COMMAND_BUFFER_SIZE];
+  size_t status;
+  size_t rlen;
+  size_t counter;
+
+  sprintf (command_buffer, "R%lu\n", (unsigned long) length);
+  if (do_command (handle, command_buffer) == -1
+      || (status = get_status (handle)) == SAFE_READ_ERROR)
+    return SAFE_READ_ERROR;
+
+  for (counter = 0; counter < status; counter += rlen, buffer += rlen)
+    {
+      rlen = safe_read (READ_SIDE (handle), buffer, status - counter);
+      if (rlen == SAFE_READ_ERROR || rlen == 0)
+	{
+	  _rmt_shutdown (handle, EIO);
+	  return SAFE_READ_ERROR;
+	}
+    }
+
+  return status;
+}
+
+/* Write LENGTH bytes from BUFFER to remote tape connection HANDLE.
+   Return the number of bytes written.  */
+size_t
+rmt_write__ (int handle, char *buffer, size_t length)
+{
+  char command_buffer[COMMAND_BUFFER_SIZE];
+  RETSIGTYPE (*pipe_handler) ();
+  size_t written;
+
+  sprintf (command_buffer, "W%lu\n", (unsigned long) length);
+  if (do_command (handle, command_buffer) == -1)
+    return 0;
+
+  pipe_handler = signal (SIGPIPE, SIG_IGN);
+  written = full_write (WRITE_SIDE (handle), buffer, length);
+  signal (SIGPIPE, pipe_handler);
+  if (written == length)
+    {
+      long int r = get_status (handle);
+      if (r < 0)
+	return 0;
+      if (r == length)
+	return length;
+      written = r;
+    }
+
+  /* Write error.  */
+
+  _rmt_shutdown (handle, EIO);
+  return written;
+}
+
+/* Perform an imitation lseek operation on remote tape connection
+   HANDLE.  Return the new file offset if successful, -1 if on error.  */
+off_t
+rmt_lseek__ (int handle, off_t offset, int whence)
+{
+  char command_buffer[COMMAND_BUFFER_SIZE];
+  char operand_buffer[UINTMAX_STRSIZE_BOUND];
+  uintmax_t u = offset < 0 ? - (uintmax_t) offset : (uintmax_t) offset;
+  char *p = operand_buffer + sizeof operand_buffer;
+
+  *--p = 0;
+  do
+    *--p = '0' + (int) (u % 10);
+  while ((u /= 10) != 0);
+  if (offset < 0)
+    *--p = '-';
+
+  switch (whence)
+    {
+    case SEEK_SET: whence = 0; break;
+    case SEEK_CUR: whence = 1; break;
+    case SEEK_END: whence = 2; break;
+    default: abort ();
+    }
+
+  sprintf (command_buffer, "L%s\n%d\n", p, whence);
+
+  if (do_command (handle, command_buffer) == -1)
+    return -1;
+
+  return get_status_off (handle);
+}
+
+/* Perform a raw tape operation on remote tape connection HANDLE.
+   Return the results of the ioctl, or -1 on error.  */
+int
+rmt_ioctl__ (int handle, int operation, char *argument)
+{
+  switch (operation)
+    {
+    default:
+      errno = EOPNOTSUPP;
+      return -1;
+
+#ifdef MTIOCTOP
+    case MTIOCTOP:
+      {
+	char command_buffer[COMMAND_BUFFER_SIZE];
+	char operand_buffer[UINTMAX_STRSIZE_BOUND];
+	uintmax_t u = (((struct mtop *) argument)->mt_count < 0
+		       ? - (uintmax_t) ((struct mtop *) argument)->mt_count
+		       : (uintmax_t) ((struct mtop *) argument)->mt_count);
+	char *p = operand_buffer + sizeof operand_buffer;
+
+        *--p = 0;
+	do
+	  *--p = '0' + (int) (u % 10);
+	while ((u /= 10) != 0);
+	if (((struct mtop *) argument)->mt_count < 0)
+	  *--p = '-';
+
+	/* MTIOCTOP is the easy one.  Nothing is transferred in binary.  */
+
+	sprintf (command_buffer, "I%d\n%s\n",
+		 ((struct mtop *) argument)->mt_op, p);
+	if (do_command (handle, command_buffer) == -1)
+	  return -1;
+
+	return get_status (handle);
+      }
+#endif /* MTIOCTOP */
+
+#ifdef MTIOCGET
+    case MTIOCGET:
+      {
+	ssize_t status;
+	size_t counter;
+
+	/* Grab the status and read it directly into the structure.  This
+	   assumes that the status buffer is not padded and that 2 shorts
+	   fit in a long without any word alignment problems; i.e., the
+	   whole struct is contiguous.  NOTE - this is probably NOT a good
+	   assumption.  */
+
+	if (do_command (handle, "S") == -1
+	    || (status = get_status (handle), status == -1))
+	  return -1;
+
+	for (; status > 0; status -= counter, argument += counter)
+	  {
+	    counter = safe_read (READ_SIDE (handle), argument, status);
+	    if (counter == SAFE_READ_ERROR || counter == 0)
+	      {
+		_rmt_shutdown (handle, EIO);
+		return -1;
+	      }
+	  }
+
+	/* Check for byte position.  mt_type (or mt_model) is a small integer
+	   field (normally) so we will check its magnitude.  If it is larger
+	   than 256, we will assume that the bytes are swapped and go through
+	   and reverse all the bytes.  */
+
+	if (((struct mtget *) argument)->MTIO_CHECK_FIELD < 256)
+	  return 0;
+
+	for (counter = 0; counter < status; counter += 2)
+	  {
+	    char copy = argument[counter];
+
+	    argument[counter] = argument[counter + 1];
+	    argument[counter + 1] = copy;
+	  }
+
+	return 0;
+      }
+#endif /* MTIOCGET */
+
+    }
+}
diff --git a/lib/system.h b/lib/system.h
new file mode 100644
index 0000000..0914195
--- /dev/null
+++ b/lib/system.h
@@ -0,0 +1,524 @@
+/* System dependent definitions for GNU tar.
+
+   Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2003,
+   2004 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+*/
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <alloca.h>
+
+#ifndef __attribute__
+/* This feature is available in gcc versions 2.5 and later.  */
+# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) || __STRICT_ANSI__
+#  define __attribute__(spec) /* empty */
+# endif
+#endif
+
+#include <sys/types.h>
+#include <ctype.h>
+
+/* IN_CTYPE_DOMAIN (C) is nonzero if the unsigned char C can safely be given
+   as an argument to <ctype.h> macros like `isspace'.  */
+#if STDC_HEADERS
+# define IN_CTYPE_DOMAIN(c) 1
+#else
+# define IN_CTYPE_DOMAIN(c) ((unsigned) (c) <= 0177)
+#endif
+
+#define ISDIGIT(c) ((unsigned) (c) - '0' <= 9)
+#define ISODIGIT(c) ((unsigned) (c) - '0' <= 7)
+#define ISPRINT(c) (IN_CTYPE_DOMAIN (c) && isprint (c))
+#define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))
+
+/* Declare string and memory handling routines.  Take care that an ANSI
+   string.h and pre-ANSI memory.h might conflict, and that memory.h and
+   strings.h conflict on some systems.  */
+
+#if STDC_HEADERS || HAVE_STRING_H
+# include <string.h>
+# if !STDC_HEADERS && HAVE_MEMORY_H
+#  include <memory.h>
+# endif
+#else
+# include <strings.h>
+# ifndef strchr
+#  define strchr index
+# endif
+# ifndef strrchr
+#  define strrchr rindex
+# endif
+# ifndef memcpy
+#  define memcpy(d, s, n) bcopy ((char const *) (s), (char *) (d), n)
+# endif
+# ifndef memcmp
+#  define memcmp(a, b, n) bcmp ((char const *) (a), (char const *) (b), n)
+# endif
+#endif
+
+/* Declare errno.  */
+
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
+/* Declare open parameters.  */
+
+#if HAVE_FCNTL_H
+# include <fcntl.h>
+#else
+# include <sys/file.h>
+#endif
+				/* Pick only one of the next three: */
+#ifndef O_RDONLY
+# define O_RDONLY	0	/* only allow read */
+#endif
+#ifndef O_WRONLY
+# define O_WRONLY	1	/* only allow write */
+#endif
+#ifndef O_RDWR
+# define O_RDWR		2	/* both are allowed */
+#endif
+#ifndef O_ACCMODE
+# define O_ACCMODE (O_RDONLY | O_RDWR | O_WRONLY)
+#endif
+				/* The rest can be OR-ed in to the above: */
+#ifndef O_CREAT
+# define O_CREAT	8	/* create file if needed */
+#endif
+#ifndef O_EXCL
+# define O_EXCL		16	/* file cannot already exist */
+#endif
+#ifndef O_TRUNC
+# define O_TRUNC	32	/* truncate file on open */
+#endif
+				/* MS-DOG forever, with my love! */
+#ifndef	O_BINARY
+# define O_BINARY 0
+#endif
+
+/* Declare file status routines and bits.  */
+
+#include <sys/stat.h>
+
+#if !HAVE_LSTAT && !defined lstat
+# define lstat stat
+#endif
+
+#if STX_HIDDEN && !_LARGE_FILES /* AIX */
+# ifdef stat
+#  undef stat
+# endif
+# define stat(file_name, buf) statx (file_name, buf, STATSIZE, STX_HIDDEN)
+# ifdef lstat
+#  undef lstat
+# endif
+# define lstat(file_name, buf) statx (file_name, buf, STATSIZE, STX_HIDDEN | STX_LINK)
+#endif
+
+#if STAT_MACROS_BROKEN
+# undef S_ISBLK
+# undef S_ISCHR
+# undef S_ISCTG
+# undef S_ISDIR
+# undef S_ISFIFO
+# undef S_ISLNK
+# undef S_ISREG
+# undef S_ISSOCK
+#endif
+
+/* On MSDOS, there are missing things from <sys/stat.h>.  */
+#if MSDOS
+# define S_ISUID 0
+# define S_ISGID 0
+# define S_ISVTX 0
+#endif
+
+#ifndef S_ISDIR
+# define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
+#endif
+#ifndef S_ISREG
+# define S_ISREG(mode) (((mode) & S_IFMT) == S_IFREG)
+#endif
+
+#ifndef S_ISBLK
+# ifdef S_IFBLK
+#  define S_ISBLK(mode) (((mode) & S_IFMT) == S_IFBLK)
+# else
+#  define S_ISBLK(mode) 0
+# endif
+#endif
+#ifndef S_ISCHR
+# ifdef S_IFCHR
+#  define S_ISCHR(mode) (((mode) & S_IFMT) == S_IFCHR)
+# else
+#  define S_ISCHR(mode) 0
+# endif
+#endif
+#ifndef S_ISCTG
+# ifdef S_IFCTG
+#  define S_ISCTG(mode) (((mode) & S_IFMT) == S_IFCTG)
+# else
+#  define S_ISCTG(mode) 0
+# endif
+#endif
+#ifndef S_ISDOOR
+# define S_ISDOOR(mode) 0
+#endif
+#ifndef S_ISFIFO
+# ifdef S_IFIFO
+#  define S_ISFIFO(mode) (((mode) & S_IFMT) == S_IFIFO)
+# else
+#  define S_ISFIFO(mode) 0
+# endif
+#endif
+#ifndef S_ISLNK
+# ifdef S_IFLNK
+#  define S_ISLNK(mode) (((mode) & S_IFMT) == S_IFLNK)
+# else
+#  define S_ISLNK(mode) 0
+# endif
+#endif
+#ifndef S_ISSOCK
+# ifdef S_IFSOCK
+#  define S_ISSOCK(mode) (((mode) & S_IFMT) == S_IFSOCK)
+# else
+#  define S_ISSOCK(mode) 0
+# endif
+#endif
+
+#if !HAVE_MKFIFO && !defined mkfifo && defined S_IFIFO
+# define mkfifo(file_name, mode) (mknod (file_name, (mode) | S_IFIFO, 0))
+#endif
+
+#ifndef S_ISUID
+# define S_ISUID 0004000
+#endif
+#ifndef S_ISGID
+# define S_ISGID 0002000
+#endif
+#ifndef S_ISVTX
+# define S_ISVTX 0001000
+#endif
+#ifndef S_IRUSR
+# define S_IRUSR 0000400
+#endif
+#ifndef S_IWUSR
+# define S_IWUSR 0000200
+#endif
+#ifndef S_IXUSR
+# define S_IXUSR 0000100
+#endif
+#ifndef S_IRGRP
+# define S_IRGRP 0000040
+#endif
+#ifndef S_IWGRP
+# define S_IWGRP 0000020
+#endif
+#ifndef S_IXGRP
+# define S_IXGRP 0000010
+#endif
+#ifndef S_IROTH
+# define S_IROTH 0000004
+#endif
+#ifndef S_IWOTH
+# define S_IWOTH 0000002
+#endif
+#ifndef S_IXOTH
+# define S_IXOTH 0000001
+#endif
+
+#define MODE_WXUSR	(S_IWUSR | S_IXUSR)
+#define MODE_R		(S_IRUSR | S_IRGRP | S_IROTH)
+#define MODE_RW		(S_IWUSR | S_IWGRP | S_IWOTH | MODE_R)
+#define MODE_RWX	(S_IXUSR | S_IXGRP | S_IXOTH | MODE_RW)
+#define MODE_ALL	(S_ISUID | S_ISGID | S_ISVTX | MODE_RWX)
+
+/* Include <unistd.h> before any preprocessor test of _POSIX_VERSION.  */
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
+#ifndef SEEK_SET
+# define SEEK_SET 0
+#endif
+#ifndef SEEK_CUR
+# define SEEK_CUR 1
+#endif
+#ifndef SEEK_END
+# define SEEK_END 2
+#endif
+
+#ifndef STDIN_FILENO
+# define STDIN_FILENO 0
+#endif
+#ifndef STDOUT_FILENO
+# define STDOUT_FILENO 1
+#endif
+#ifndef STDERR_FILENO
+# define STDERR_FILENO 2
+#endif
+
+/* Declare make device, major and minor.  Since major is a function on
+   SVR4, we have to resort to GOT_MAJOR instead of just testing if
+   major is #define'd.  */
+
+#if MAJOR_IN_MKDEV
+# include <sys/mkdev.h>
+# define GOT_MAJOR
+#endif
+
+#if MAJOR_IN_SYSMACROS
+# include <sys/sysmacros.h>
+# define GOT_MAJOR
+#endif
+
+/* Some <sys/types.h> defines the macros. */
+#ifdef major
+# define GOT_MAJOR
+#endif
+
+#ifndef GOT_MAJOR
+# if MSDOS
+#  define major(device)		(device)
+#  define minor(device)		(device)
+#  define makedev(major, minor)	(((major) << 8) | (minor))
+#  define GOT_MAJOR
+# endif
+#endif
+
+/* For HP-UX before HP-UX 8, major/minor are not in <sys/sysmacros.h>.  */
+#ifndef GOT_MAJOR
+# if defined(hpux) || defined(__hpux__) || defined(__hpux)
+#  include <sys/mknod.h>
+#  define GOT_MAJOR
+# endif
+#endif
+
+#ifndef GOT_MAJOR
+# define major(device)		(((device) >> 8) & 0xff)
+# define minor(device)		((device) & 0xff)
+# define makedev(major, minor)	(((major) << 8) | (minor))
+#endif
+
+#undef GOT_MAJOR
+
+/* Declare wait status.  */
+
+#if HAVE_SYS_WAIT_H
+# include <sys/wait.h>
+#endif
+#ifndef WEXITSTATUS
+# define WEXITSTATUS(s)	(((s) >> 8) & 0xff)
+#endif
+#ifndef WIFSIGNALED
+# define WIFSIGNALED(s)	(((s) & 0xffff) - 1 < (unsigned) 0xff)
+#endif
+#ifndef WTERMSIG
+# define WTERMSIG(s)	((s) & 0x7f)
+#endif
+
+/* FIXME: It is wrong to use BLOCKSIZE for buffers when the logical block
+   size is greater than 512 bytes; so ST_BLKSIZE code below, in preparation
+   for some cleanup in this area, later.  */
+
+/* Extract or fake data from a `struct stat'.  ST_BLKSIZE gives the
+   optimal I/O blocksize for the file, in bytes.  Some systems, like
+   Sequents, return st_blksize of 0 on pipes.  */
+
+#define DEFAULT_ST_BLKSIZE 512
+
+#if !HAVE_ST_BLKSIZE
+# define ST_BLKSIZE(statbuf) DEFAULT_ST_BLKSIZE
+#else
+# define ST_BLKSIZE(statbuf) \
+    ((statbuf).st_blksize > 0 ? (statbuf).st_blksize : DEFAULT_ST_BLKSIZE)
+#endif
+
+/* Extract or fake data from a `struct stat'.  ST_NBLOCKS gives the
+   number of ST_NBLOCKSIZE-byte blocks in the file (including indirect blocks).
+   HP-UX counts st_blocks in 1024-byte units,
+   this loses when mixing HP-UX and BSD filesystems with NFS.  AIX PS/2
+   counts st_blocks in 4K units.  */
+
+#if !HAVE_ST_BLOCKS
+# if defined(_POSIX_SOURCE) || !defined(BSIZE)
+#  define ST_NBLOCKS(statbuf) ((statbuf).st_size / ST_NBLOCKSIZE + ((statbuf).st_size % ST_NBLOCKSIZE != 0))
+# else
+   off_t st_blocks ();
+#  define ST_NBLOCKS(statbuf) (st_blocks ((statbuf).st_size))
+# endif
+#else
+# define ST_NBLOCKS(statbuf) ((statbuf).st_blocks)
+# if defined(hpux) || defined(__hpux__) || defined(__hpux)
+#  define ST_NBLOCKSIZE 1024
+# else
+#  if defined(_AIX) && defined(_I386)
+#   define ST_NBLOCKSIZE (4 * 1024)
+#  endif
+# endif
+#endif
+
+#ifndef ST_NBLOCKSIZE
+#define ST_NBLOCKSIZE 512
+#endif
+
+/* This is a real challenge to properly get MTIO* symbols :-(.  ISC uses
+   <sys/gentape.h>.  SCO and BSDi uses <sys/tape.h>; BSDi also requires
+   <sys/tprintf.h> and <sys/device.h> for defining tp_dev and tpr_t.  It
+   seems that the rest use <sys/mtio.h>, which itself requires other files,
+   depending on systems.  Pyramid defines _IOW in <sgtty.h>, for example.  */
+
+#if HAVE_SYS_GENTAPE_H
+# include <sys/gentape.h>
+#else
+# if HAVE_SYS_TAPE_H
+#  if HAVE_SYS_DEVICE_H
+#   include <sys/device.h>
+#  endif
+#  if HAVE_SYS_PARAM_H
+#   include <sys/param.h>
+#  endif
+#  if HAVE_SYS_BUF_H
+#   include <sys/buf.h>
+#  endif
+#  if HAVE_SYS_TPRINTF_H
+#   include <sys/tprintf.h>
+#  endif
+#  include <sys/tape.h>
+# else
+#  if HAVE_SYS_MTIO_H
+#   include <sys/ioctl.h>
+#   if HAVE_SGTTY_H
+#    include <sgtty.h>
+#   endif
+#   if HAVE_SYS_IO_TRIOCTL_H
+#    include <sys/io/trioctl.h>
+#   endif
+#   include <sys/mtio.h>
+#  endif
+# endif
+#endif
+
+/* Declare standard functions.  */
+
+#if STDC_HEADERS
+# include <stdlib.h>
+#else
+void *malloc ();
+char *getenv ();
+#endif
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#include <stdio.h>
+#if !defined _POSIX_VERSION && MSDOS
+# include <io.h>
+#endif
+
+#if WITH_DMALLOC
+# undef HAVE_DECL_VALLOC
+# define DMALLOC_FUNC_CHECK
+# include <dmalloc.h>
+#endif
+
+#include <limits.h>
+
+#ifndef MB_LEN_MAX
+# define MB_LEN_MAX 1
+#endif
+
+#if HAVE_INTTYPES_H
+# include <inttypes.h>
+#endif
+
+/* These macros work even on ones'-complement hosts (!).
+   The extra casts work around common compiler bugs.  */
+#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
+#define TYPE_MINIMUM(t) (TYPE_SIGNED (t) \
+			 ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) \
+			 : (t) 0)
+#define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t)))
+
+/* Bound on length of the string representing an integer value of type t.
+   Subtract one for the sign bit if t is signed;
+   302 / 1000 is log10 (2) rounded up;
+   add one for integer division truncation;
+   add one more for a minus sign if t is signed.  */
+#define INT_STRLEN_BOUND(t) \
+  ((sizeof (t) * CHAR_BIT - TYPE_SIGNED (t)) * 302 / 1000 \
+   + 1 + TYPE_SIGNED (t))
+
+#define UINTMAX_STRSIZE_BOUND (INT_STRLEN_BOUND (uintmax_t) + 1)
+
+/* Prototypes for external functions.  */
+
+#if HAVE_LOCALE_H
+# include <locale.h>
+#endif
+#if !HAVE_SETLOCALE
+# define setlocale(category, locale) /* empty */
+#endif
+
+#include <time.h>
+#if defined(HAVE_SYS_TIME_H) && defined(TIME_WITH_SYS_TIME)
+# include <sys/time.h>
+#endif
+#if ! HAVE_DECL_TIME
+time_t time ();
+#endif
+
+#ifdef HAVE_UTIME_H
+# include <utime.h>
+#endif
+
+/* Library modules.  */
+
+#include <dirname.h>
+#include <error.h>
+#include <savedir.h>
+#include <unlocked-io.h>
+#include <xalloc.h>
+
+#include <gettext.h>
+#define _(msgid) gettext (msgid)
+#define N_(msgid) msgid
+
+#if MSDOS
+# include <process.h>
+# define SET_BINARY_MODE(arc) setmode(arc, O_BINARY)
+# define ERRNO_IS_EACCES errno == EACCES
+# define mkdir(file, mode) (mkdir) (file)
+# define TTY_NAME "con"
+# define sys_reset_uid_gid()
+#else
+# include <pwd.h>
+# include <grp.h>
+# define SET_BINARY_MODE(arc)
+# define ERRNO_IS_EACCES 0
+# define TTY_NAME "/dev/tty"
+# define sys_reset_uid_gid() \
+ do { setuid (getuid ()); setgid (getgid ()); } while (0)
+#endif
+
+#if XENIX
+# include <sys/inode.h>
+#endif